]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/uipc_socket.c
xnu-7195.50.7.100.1.tar.gz
[apple/xnu.git] / bsd / kern / uipc_socket.c
index c8fc70ca3c911273dc01b408c220580a82dc9ff3..607af6d3c5aba890df75bbf09b4240c933bc4e38 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998-2016 Apple Inc. All rights reserved.
+ * Copyright (c) 1998-2020 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  *
 #include <sys/kern_event.h>
 #include <net/route.h>
 #include <net/init.h>
+#include <net/net_api_stats.h>
 #include <net/ntstat.h>
 #include <net/content_filter.h>
 #include <netinet/in.h>
 #include <netinet/in_pcb.h>
 #include <netinet/in_tclass.h>
+#include <netinet/in_var.h>
 #include <netinet/tcp_var.h>
 #include <netinet/ip6.h>
 #include <netinet6/ip6_var.h>
 #include <sys/kpi_mbuf.h>
 #include <sys/mcache.h>
 #include <sys/unpcb.h>
+#include <libkern/section_keywords.h>
 
 #if CONFIG_MACF
-#include <security/mac.h>
 #include <security/mac_framework.h>
 #endif /* MAC */
 
 #define ROUNDUP(a, b) (((a) + ((b) - 1)) & (~((b) - 1)))
 
 #if DEBUG || DEVELOPMENT
-#define        DEBUG_KERNEL_ADDRPERM(_v) (_v)
+#define DEBUG_KERNEL_ADDRPERM(_v) (_v)
 #else
-#define        DEBUG_KERNEL_ADDRPERM(_v) VM_KERNEL_ADDRPERM(_v)
+#define DEBUG_KERNEL_ADDRPERM(_v) VM_KERNEL_ADDRPERM(_v)
 #endif
 
 /* TODO: this should be in a header file somewhere */
 extern char *proc_name_address(void *p);
-extern char *proc_best_name(proc_t);
-
-static u_int32_t       so_cache_hw;    /* High water mark for socache */
-static u_int32_t       so_cache_timeouts;      /* number of timeouts */
-static u_int32_t       so_cache_max_freed;     /* max freed per timeout */
-static u_int32_t       cached_sock_count = 0;
-STAILQ_HEAD(, socket)  so_cache_head;
-int    max_cached_sock_count = MAX_CACHED_SOCKETS;
-static u_int32_t       so_cache_time;
-static int             socketinit_done;
-static struct zone     *so_cache_zone;
-
-static lck_grp_t       *so_cache_mtx_grp;
-static lck_attr_t      *so_cache_mtx_attr;
-static lck_grp_attr_t  *so_cache_mtx_grp_attr;
-static lck_mtx_t       *so_cache_mtx;
+
+static u_int32_t        so_cache_hw;    /* High water mark for socache */
+static u_int32_t        so_cache_timeouts;      /* number of timeouts */
+static u_int32_t        so_cache_max_freed;     /* max freed per timeout */
+static u_int32_t        cached_sock_count = 0;
+STAILQ_HEAD(, socket)   so_cache_head;
+int     max_cached_sock_count = MAX_CACHED_SOCKETS;
+static u_int32_t        so_cache_time;
+static int              socketinit_done;
+static struct zone      *so_cache_zone;
+
+static lck_grp_t        *so_cache_mtx_grp;
+static lck_attr_t       *so_cache_mtx_attr;
+static lck_grp_attr_t   *so_cache_mtx_grp_attr;
+static lck_mtx_t        *so_cache_mtx;
 
 #include <machine/limits.h>
 
-static int     filt_sorattach(struct knote *kn);
-static void    filt_sordetach(struct knote *kn);
-static int     filt_soread(struct knote *kn, long hint);
-static int     filt_sortouch(struct knote *kn, struct kevent_internal_s *kev);
-static int     filt_sorprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev);
+static int      filt_sorattach(struct knote *kn, struct kevent_qos_s *kev);
+static void     filt_sordetach(struct knote *kn);
+static int      filt_soread(struct knote *kn, long hint);
+static int      filt_sortouch(struct knote *kn, struct kevent_qos_s *kev);
+static int      filt_sorprocess(struct knote *kn, struct kevent_qos_s *kev);
 
-static int     filt_sowattach(struct knote *kn);
-static void    filt_sowdetach(struct knote *kn);
-static int     filt_sowrite(struct knote *kn, long hint);
-static int     filt_sowtouch(struct knote *kn, struct kevent_internal_s *kev);
-static int     filt_sowprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev);
+static int      filt_sowattach(struct knote *kn, struct kevent_qos_s *kev);
+static void     filt_sowdetach(struct knote *kn);
+static int      filt_sowrite(struct knote *kn, long hint);
+static int      filt_sowtouch(struct knote *kn, struct kevent_qos_s *kev);
+static int      filt_sowprocess(struct knote *kn, struct kevent_qos_s *kev);
 
-static int     filt_sockattach(struct knote *kn);
-static void    filt_sockdetach(struct knote *kn);
-static int     filt_sockev(struct knote *kn, long hint);
-static int     filt_socktouch(struct knote *kn, struct kevent_internal_s *kev);
-static int     filt_sockprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev);
+static int      filt_sockattach(struct knote *kn, struct kevent_qos_s *kev);
+static void     filt_sockdetach(struct knote *kn);
+static int      filt_sockev(struct knote *kn, long hint);
+static int      filt_socktouch(struct knote *kn, struct kevent_qos_s *kev);
+static int      filt_sockprocess(struct knote *kn, struct kevent_qos_s *kev);
 
 static int sooptcopyin_timeval(struct sockopt *, struct timeval *);
 static int sooptcopyout_timeval(struct sockopt *, const struct timeval *);
 
-struct filterops soread_filtops = {
+SECURITY_READ_ONLY_EARLY(struct filterops) soread_filtops = {
        .f_isfd = 1,
        .f_attach = filt_sorattach,
        .f_detach = filt_sordetach,
@@ -189,7 +190,7 @@ struct filterops soread_filtops = {
        .f_process = filt_sorprocess,
 };
 
-struct filterops sowrite_filtops = {
+SECURITY_READ_ONLY_EARLY(struct filterops) sowrite_filtops = {
        .f_isfd = 1,
        .f_attach = filt_sowattach,
        .f_detach = filt_sowdetach,
@@ -198,7 +199,7 @@ struct filterops sowrite_filtops = {
        .f_process = filt_sowprocess,
 };
 
-struct filterops sock_filtops = {
+SECURITY_READ_ONLY_EARLY(struct filterops) sock_filtops = {
        .f_isfd = 1,
        .f_attach = filt_sockattach,
        .f_detach = filt_sockdetach,
@@ -207,7 +208,7 @@ struct filterops sock_filtops = {
        .f_process = filt_sockprocess,
 };
 
-struct filterops soexcept_filtops = {
+SECURITY_READ_ONLY_EARLY(struct filterops) soexcept_filtops = {
        .f_isfd = 1,
        .f_attach = filt_sorattach,
        .f_detach = filt_sordetach,
@@ -218,46 +219,46 @@ struct filterops soexcept_filtops = {
 
 SYSCTL_DECL(_kern_ipc);
 
-#define        EVEN_MORE_LOCKING_DEBUG 0
+#define EVEN_MORE_LOCKING_DEBUG 0
 
 int socket_debug = 0;
 SYSCTL_INT(_kern_ipc, OID_AUTO, socket_debug,
-       CTLFLAG_RW | CTLFLAG_LOCKED, &socket_debug, 0, "");
+    CTLFLAG_RW | CTLFLAG_LOCKED, &socket_debug, 0, "");
 
 static unsigned long sodefunct_calls = 0;
 SYSCTL_LONG(_kern_ipc, OID_AUTO, sodefunct_calls, CTLFLAG_LOCKED,
     &sodefunct_calls, "");
 
-static int socket_zone = M_SOCKET;
-so_gen_t       so_gencnt;      /* generation count for sockets */
+ZONE_DECLARE(socket_zone, "socket", sizeof(struct socket), ZC_ZFREE_CLEARMEM);
+so_gen_t        so_gencnt;      /* generation count for sockets */
 
 MALLOC_DEFINE(M_SONAME, "soname", "socket name");
 MALLOC_DEFINE(M_PCB, "pcb", "protocol control block");
 
-#define        DBG_LAYER_IN_BEG        NETDBG_CODE(DBG_NETSOCK, 0)
-#define        DBG_LAYER_IN_END        NETDBG_CODE(DBG_NETSOCK, 2)
-#define        DBG_LAYER_OUT_BEG       NETDBG_CODE(DBG_NETSOCK, 1)
-#define        DBG_LAYER_OUT_END       NETDBG_CODE(DBG_NETSOCK, 3)
-#define        DBG_FNC_SOSEND          NETDBG_CODE(DBG_NETSOCK, (4 << 8) | 1)
-#define        DBG_FNC_SOSEND_LIST     NETDBG_CODE(DBG_NETSOCK, (4 << 8) | 3)
-#define        DBG_FNC_SORECEIVE       NETDBG_CODE(DBG_NETSOCK, (8 << 8))
-#define        DBG_FNC_SORECEIVE_LIST  NETDBG_CODE(DBG_NETSOCK, (8 << 8) | 3)
-#define        DBG_FNC_SOSHUTDOWN      NETDBG_CODE(DBG_NETSOCK, (9 << 8))
+#define DBG_LAYER_IN_BEG        NETDBG_CODE(DBG_NETSOCK, 0)
+#define DBG_LAYER_IN_END        NETDBG_CODE(DBG_NETSOCK, 2)
+#define DBG_LAYER_OUT_BEG       NETDBG_CODE(DBG_NETSOCK, 1)
+#define DBG_LAYER_OUT_END       NETDBG_CODE(DBG_NETSOCK, 3)
+#define DBG_FNC_SOSEND          NETDBG_CODE(DBG_NETSOCK, (4 << 8) | 1)
+#define DBG_FNC_SOSEND_LIST     NETDBG_CODE(DBG_NETSOCK, (4 << 8) | 3)
+#define DBG_FNC_SORECEIVE       NETDBG_CODE(DBG_NETSOCK, (8 << 8))
+#define DBG_FNC_SORECEIVE_LIST  NETDBG_CODE(DBG_NETSOCK, (8 << 8) | 3)
+#define DBG_FNC_SOSHUTDOWN      NETDBG_CODE(DBG_NETSOCK, (9 << 8))
 
-#define        MAX_SOOPTGETM_SIZE      (128 * MCLBYTES)
+#define MAX_SOOPTGETM_SIZE      (128 * MCLBYTES)
 
 int somaxconn = SOMAXCONN;
 SYSCTL_INT(_kern_ipc, KIPC_SOMAXCONN, somaxconn,
-       CTLFLAG_RW | CTLFLAG_LOCKED, &somaxconn, 0, "");
+    CTLFLAG_RW | CTLFLAG_LOCKED, &somaxconn, 0, "");
 
 /* Should we get a maximum also ??? */
 static int sosendmaxchain = 65536;
 static int sosendminchain = 16384;
 static int sorecvmincopy  = 16384;
 SYSCTL_INT(_kern_ipc, OID_AUTO, sosendminchain,
-       CTLFLAG_RW | CTLFLAG_LOCKED, &sosendminchain, 0, "");
+    CTLFLAG_RW | CTLFLAG_LOCKED, &sosendminchain, 0, "");
 SYSCTL_INT(_kern_ipc, OID_AUTO, sorecvmincopy,
-       CTLFLAG_RW | CTLFLAG_LOCKED, &sorecvmincopy, 0, "");
+    CTLFLAG_RW | CTLFLAG_LOCKED, &sorecvmincopy, 0, "");
 
 /*
  * Set to enable jumbo clusters (if available) for large writes when
@@ -265,7 +266,7 @@ SYSCTL_INT(_kern_ipc, OID_AUTO, sorecvmincopy,
  */
 int sosendjcl = 1;
 SYSCTL_INT(_kern_ipc, OID_AUTO, sosendjcl,
-       CTLFLAG_RW | CTLFLAG_LOCKED, &sosendjcl, 0, "");
+    CTLFLAG_RW | CTLFLAG_LOCKED, &sosendjcl, 0, "");
 
 /*
  * Set this to ignore SOF_MULTIPAGES and use jumbo clusters for large
@@ -280,7 +281,7 @@ SYSCTL_INT(_kern_ipc, OID_AUTO, sosendjcl,
  */
 int sosendjcl_ignore_capab = 0;
 SYSCTL_INT(_kern_ipc, OID_AUTO, sosendjcl_ignore_capab,
-       CTLFLAG_RW | CTLFLAG_LOCKED, &sosendjcl_ignore_capab, 0, "");
+    CTLFLAG_RW | CTLFLAG_LOCKED, &sosendjcl_ignore_capab, 0, "");
 
 /*
  * Set this to ignore SOF1_IF_2KCL and use big clusters for large
@@ -293,51 +294,51 @@ SYSCTL_INT(_kern_ipc, OID_AUTO, sosendjcl_ignore_capab,
  */
 int sosendbigcl_ignore_capab = 0;
 SYSCTL_INT(_kern_ipc, OID_AUTO, sosendbigcl_ignore_capab,
-       CTLFLAG_RW | CTLFLAG_LOCKED, &sosendbigcl_ignore_capab, 0, "");
+    CTLFLAG_RW | CTLFLAG_LOCKED, &sosendbigcl_ignore_capab, 0, "");
 
 int sodefunctlog = 0;
 SYSCTL_INT(_kern_ipc, OID_AUTO, sodefunctlog, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &sodefunctlog, 0, "");
+    &sodefunctlog, 0, "");
 
 int sothrottlelog = 0;
 SYSCTL_INT(_kern_ipc, OID_AUTO, sothrottlelog, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &sothrottlelog, 0, "");
+    &sothrottlelog, 0, "");
 
 int sorestrictrecv = 1;
 SYSCTL_INT(_kern_ipc, OID_AUTO, sorestrictrecv, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &sorestrictrecv, 0, "Enable inbound interface restrictions");
+    &sorestrictrecv, 0, "Enable inbound interface restrictions");
 
 int sorestrictsend = 1;
 SYSCTL_INT(_kern_ipc, OID_AUTO, sorestrictsend, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &sorestrictsend, 0, "Enable outbound interface restrictions");
+    &sorestrictsend, 0, "Enable outbound interface restrictions");
 
 int soreserveheadroom = 1;
 SYSCTL_INT(_kern_ipc, OID_AUTO, soreserveheadroom, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &soreserveheadroom, 0, "To allocate contiguous datagram buffers");
+    &soreserveheadroom, 0, "To allocate contiguous datagram buffers");
 
 #if (DEBUG || DEVELOPMENT)
 int so_notsent_lowat_check = 1;
-SYSCTL_INT(_kern_ipc, OID_AUTO, notsent_lowat, CTLFLAG_RW|CTLFLAG_LOCKED,
+SYSCTL_INT(_kern_ipc, OID_AUTO, notsent_lowat, CTLFLAG_RW | CTLFLAG_LOCKED,
     &so_notsent_lowat_check, 0, "enable/disable notsnet lowat check");
 #endif /* DEBUG || DEVELOPMENT */
 
+int so_accept_list_waits = 0;
+#if (DEBUG || DEVELOPMENT)
+SYSCTL_INT(_kern_ipc, OID_AUTO, accept_list_waits, CTLFLAG_RW | CTLFLAG_LOCKED,
+    &so_accept_list_waits, 0, "number of waits for listener incomp list");
+#endif /* DEBUG || DEVELOPMENT */
+
 extern struct inpcbinfo tcbinfo;
 
 /* TODO: these should be in header file */
 extern int get_inpcb_str_size(void);
 extern int get_tcp_str_size(void);
 
-static unsigned int sl_zone_size;              /* size of sockaddr_list */
-static struct zone *sl_zone;                   /* zone for sockaddr_list */
-
-static unsigned int se_zone_size;              /* size of sockaddr_entry */
-static struct zone *se_zone;                   /* zone for sockaddr_entry */
-
-vm_size_t      so_cache_zone_element_size;
+vm_size_t       so_cache_zone_element_size;
 
 static int sodelayed_copy(struct socket *, struct uio *, struct mbuf **,
     user_ssize_t *);
-static void cached_sock_alloc(struct socket **, int);
+static void cached_sock_alloc(struct socket **, zalloc_flags_t);
 static void cached_sock_free(struct socket *);
 
 /*
@@ -345,29 +346,30 @@ static void cached_sock_free(struct socket *);
  * Set to zero to disable further setting of the option
  */
 
-#define        SO_IDLE_BK_IDLE_MAX_PER_PROC    1
-#define        SO_IDLE_BK_IDLE_TIME            600
-#define        SO_IDLE_BK_IDLE_RCV_HIWAT       131072
+#define SO_IDLE_BK_IDLE_MAX_PER_PROC    1
+#define SO_IDLE_BK_IDLE_TIME            600
+#define SO_IDLE_BK_IDLE_RCV_HIWAT       131072
 
 struct soextbkidlestat soextbkidlestat;
 
 SYSCTL_UINT(_kern_ipc, OID_AUTO, maxextbkidleperproc,
-       CTLFLAG_RW | CTLFLAG_LOCKED, &soextbkidlestat.so_xbkidle_maxperproc, 0,
-       "Maximum of extended background idle sockets per process");
+    CTLFLAG_RW | CTLFLAG_LOCKED, &soextbkidlestat.so_xbkidle_maxperproc, 0,
+    "Maximum of extended background idle sockets per process");
 
 SYSCTL_UINT(_kern_ipc, OID_AUTO, extbkidletime, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &soextbkidlestat.so_xbkidle_time, 0,
-       "Time in seconds to keep extended background idle sockets");
+    &soextbkidlestat.so_xbkidle_time, 0,
+    "Time in seconds to keep extended background idle sockets");
 
 SYSCTL_UINT(_kern_ipc, OID_AUTO, extbkidlercvhiwat, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &soextbkidlestat.so_xbkidle_rcvhiwat, 0,
-       "High water mark for extended background idle sockets");
+    &soextbkidlestat.so_xbkidle_rcvhiwat, 0,
+    "High water mark for extended background idle sockets");
 
 SYSCTL_STRUCT(_kern_ipc, OID_AUTO, extbkidlestat, CTLFLAG_RD | CTLFLAG_LOCKED,
-       &soextbkidlestat, soextbkidlestat, "");
+    &soextbkidlestat, soextbkidlestat, "");
 
 int so_set_extended_bk_idle(struct socket *, int);
 
+
 /*
  * SOTCDB_NO_DSCP is set by default, to prevent the networking stack from
  * setting the DSCP code on the packet based on the service class; see
@@ -375,7 +377,7 @@ int so_set_extended_bk_idle(struct socket *, int);
  */
 __private_extern__ u_int32_t sotcdb = 0;
 SYSCTL_INT(_kern_ipc, OID_AUTO, sotcdb, CTLFLAG_RW | CTLFLAG_LOCKED,
-       &sotcdb, 0, "");
+    &sotcdb, 0, "");
 
 void
 socketinit(void)
@@ -406,7 +408,7 @@ socketinit(void)
        socketinit_done = 1;
 
        PE_parse_boot_argn("socket_debug", &socket_debug,
-           sizeof (socket_debug));
+           sizeof(socket_debug));
 
        /*
         * allocate lock group attribute and group for socket cache mutex
@@ -428,31 +430,11 @@ socketinit(void)
        }
        STAILQ_INIT(&so_cache_head);
 
-       so_cache_zone_element_size = (vm_size_t)(sizeof (struct socket) + 4
+       so_cache_zone_element_size = (vm_size_t)(sizeof(struct socket) + 4
            + get_inpcb_str_size() + 4 + get_tcp_str_size());
 
-       so_cache_zone = zinit(so_cache_zone_element_size,
-           (120000 * so_cache_zone_element_size), 8192, "socache zone");
-       zone_change(so_cache_zone, Z_CALLERACCT, FALSE);
-       zone_change(so_cache_zone, Z_NOENCRYPT, TRUE);
-
-       sl_zone_size = sizeof (struct sockaddr_list);
-       if ((sl_zone = zinit(sl_zone_size, 1024 * sl_zone_size, 1024,
-           "sockaddr_list")) == NULL) {
-               panic("%s: unable to allocate sockaddr_list zone\n", __func__);
-               /* NOTREACHED */
-       }
-       zone_change(sl_zone, Z_CALLERACCT, FALSE);
-       zone_change(sl_zone, Z_EXPAND, TRUE);
-
-       se_zone_size = sizeof (struct sockaddr_entry);
-       if ((se_zone = zinit(se_zone_size, 1024 * se_zone_size, 1024,
-           "sockaddr_entry")) == NULL) {
-               panic("%s: unable to allocate sockaddr_entry zone\n", __func__);
-               /* NOTREACHED */
-       }
-       zone_change(se_zone, Z_CALLERACCT, FALSE);
-       zone_change(se_zone, Z_EXPAND, TRUE);
+       so_cache_zone = zone_create("socache zone", so_cache_zone_element_size,
+           ZC_ZFREE_CLEARMEM | ZC_NOENCRYPT);
 
        bzero(&soextbkidlestat, sizeof(struct soextbkidlestat));
        soextbkidlestat.so_xbkidle_maxperproc = SO_IDLE_BK_IDLE_MAX_PER_PROC;
@@ -468,9 +450,9 @@ socketinit(void)
 }
 
 static void
-cached_sock_alloc(struct socket **so, int waitok)
+cached_sock_alloc(struct socket **so, zalloc_flags_t how)
 {
-       caddr_t temp;
+       caddr_t temp;
        uintptr_t offset;
 
        lck_mtx_lock(so_cache_mtx);
@@ -486,22 +468,13 @@ cached_sock_alloc(struct socket **so, int waitok)
                lck_mtx_unlock(so_cache_mtx);
 
                temp = (*so)->so_saved_pcb;
-               bzero((caddr_t)*so, sizeof (struct socket));
+               bzero((caddr_t)*so, sizeof(struct socket));
 
                (*so)->so_saved_pcb = temp;
        } else {
-
                lck_mtx_unlock(so_cache_mtx);
 
-               if (waitok)
-                       *so = (struct socket *)zalloc(so_cache_zone);
-               else
-                       *so = (struct socket *)zalloc_noblock(so_cache_zone);
-
-               if (*so == NULL)
-                       return;
-
-               bzero((caddr_t)*so, sizeof (struct socket));
+               *so = zalloc_flags(so_cache_zone, how | Z_ZERO);
 
                /*
                 * Define offsets for extra structures into our
@@ -510,7 +483,7 @@ cached_sock_alloc(struct socket **so, int waitok)
                 */
 
                offset = (uintptr_t)*so;
-               offset += sizeof (struct socket);
+               offset += sizeof(struct socket);
 
                offset = ALIGN(offset);
 
@@ -529,7 +502,6 @@ cached_sock_alloc(struct socket **so, int waitok)
 static void
 cached_sock_free(struct socket *so)
 {
-
        lck_mtx_lock(so_cache_mtx);
 
        so_cache_time = net_uptime();
@@ -538,8 +510,9 @@ cached_sock_free(struct socket *so)
                lck_mtx_unlock(so_cache_mtx);
                zfree(so_cache_zone, so);
        } else {
-               if (so_cache_hw < cached_sock_count)
+               if (so_cache_hw < cached_sock_count) {
                        so_cache_hw = cached_sock_count;
+               }
 
                STAILQ_INSERT_TAIL(&so_cache_head, so, so_cache_ent);
 
@@ -556,15 +529,19 @@ so_update_last_owner_locked(struct socket *so, proc_t self)
                 * last_pid and last_upid should remain zero for sockets
                 * created using sock_socket. The check above achieves that
                 */
-               if (self == PROC_NULL)
+               if (self == PROC_NULL) {
                        self = current_proc();
+               }
 
                if (so->last_upid != proc_uniqueid(self) ||
                    so->last_pid != proc_pid(self)) {
                        so->last_upid = proc_uniqueid(self);
                        so->last_pid = proc_pid(self);
                        proc_getexecutableuuid(self, so->last_uuid,
-                           sizeof (so->last_uuid));
+                           sizeof(so->last_uuid));
+                       if (so->so_proto != NULL && so->so_proto->pr_update_last_owner != NULL) {
+                               (*so->so_proto->pr_update_last_owner)(so, self, NULL);
+                       }
                }
                proc_pidoriginatoruuid(so->so_vuuid, sizeof(so->so_vuuid));
        }
@@ -573,8 +550,9 @@ so_update_last_owner_locked(struct socket *so, proc_t self)
 void
 so_update_policy(struct socket *so)
 {
-       if (SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6)
+       if (SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6) {
                (void) inp_update_policy(sotoinpcb(so));
+       }
 }
 
 #if NECP
@@ -582,17 +560,18 @@ static void
 so_update_necp_policy(struct socket *so, struct sockaddr *override_local_addr,
     struct sockaddr *override_remote_addr)
 {
-       if (SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6)
+       if (SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6) {
                inp_update_necp_policy(sotoinpcb(so), override_local_addr,
                    override_remote_addr, 0);
+       }
 }
 #endif /* NECP */
 
 boolean_t
 so_cache_timer(void)
 {
-       struct socket   *p;
-       int             n_freed = 0;
+       struct socket   *p;
+       int             n_freed = 0;
        boolean_t rc = FALSE;
 
        lck_mtx_lock(so_cache_mtx);
@@ -603,8 +582,9 @@ so_cache_timer(void)
                VERIFY(cached_sock_count > 0);
                p = STAILQ_FIRST(&so_cache_head);
                if ((so_cache_time - p->cache_timestamp) <
-                       SO_CACHE_TIME_LIMIT)
+                   SO_CACHE_TIME_LIMIT) {
                        break;
+               }
 
                STAILQ_REMOVE_HEAD(&so_cache_head, so_cache_ent);
                --cached_sock_count;
@@ -618,11 +598,12 @@ so_cache_timer(void)
        }
 
        /* Schedule again if there is more to cleanup */
-       if (!STAILQ_EMPTY(&so_cache_head))
+       if (!STAILQ_EMPTY(&so_cache_head)) {
                rc = TRUE;
+       }
 
        lck_mtx_unlock(so_cache_mtx);
-       return (rc);
+       return rc;
 }
 
 /*
@@ -635,29 +616,24 @@ so_cache_timer(void)
 struct socket *
 soalloc(int waitok, int dom, int type)
 {
+       zalloc_flags_t how = waitok ? Z_WAITOK : Z_NOWAIT;
        struct socket *so;
 
        if ((dom == PF_INET) && (type == SOCK_STREAM)) {
-               cached_sock_alloc(&so, waitok);
+               cached_sock_alloc(&so, how);
        } else {
-               MALLOC_ZONE(so, struct socket *, sizeof (*so), socket_zone,
-                   M_WAITOK);
-               if (so != NULL)
-                       bzero(so, sizeof (*so));
+               so = zalloc_flags(socket_zone, how | Z_ZERO);
        }
        if (so != NULL) {
                so->so_gencnt = OSIncrementAtomic64((SInt64 *)&so_gencnt);
-               so->so_zone = socket_zone;
-#if CONFIG_MACF_SOCKET
-               /* Convert waitok to  M_WAITOK/M_NOWAIT for MAC Framework. */
-               if (mac_socket_label_init(so, !waitok) != 0) {
-                       sodealloc(so);
-                       return (NULL);
-               }
-#endif /* MAC_SOCKET */
+
+               /*
+                * Increment the socket allocation statistics
+                */
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_alloc_total);
        }
 
-       return (so);
+       return so;
 }
 
 int
@@ -667,6 +643,9 @@ socreate_internal(int dom, struct socket **aso, int type, int proto,
        struct protosw *prp;
        struct socket *so;
        int error = 0;
+#if defined(XNU_TARGET_OS_OSX)
+       pid_t rpid = -1;
+#endif
 
 #if TCPDEBUG
        extern int tcpconsdebug;
@@ -675,58 +654,116 @@ socreate_internal(int dom, struct socket **aso, int type, int proto,
        VERIFY(aso != NULL);
        *aso = NULL;
 
-       if (proto != 0)
+       if (proto != 0) {
                prp = pffindproto(dom, proto, type);
-       else
+       } else {
                prp = pffindtype(dom, type);
+       }
 
        if (prp == NULL || prp->pr_usrreqs->pru_attach == NULL) {
-               if (pffinddomain(dom) == NULL)
-                       return (EAFNOSUPPORT);
+               if (pffinddomain(dom) == NULL) {
+                       return EAFNOSUPPORT;
+               }
                if (proto != 0) {
-                       if (pffindprotonotype(dom, proto) != NULL)
-                               return (EPROTOTYPE);
+                       if (pffindprotonotype(dom, proto) != NULL) {
+                               return EPROTOTYPE;
+                       }
                }
-               return (EPROTONOSUPPORT);
+               return EPROTONOSUPPORT;
+       }
+       if (prp->pr_type != type) {
+               return EPROTOTYPE;
        }
-       if (prp->pr_type != type)
-               return (EPROTOTYPE);
        so = soalloc(1, dom, type);
-       if (so == NULL)
-               return (ENOBUFS);
+       if (so == NULL) {
+               return ENOBUFS;
+       }
+
+       switch (dom) {
+       case PF_LOCAL:
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_domain_local_total);
+               break;
+       case PF_INET:
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_domain_inet_total);
+               if (type == SOCK_STREAM) {
+                       INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_inet_stream_total);
+               } else {
+                       INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_inet_dgram_total);
+               }
+               break;
+       case PF_ROUTE:
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_domain_route_total);
+               break;
+       case PF_NDRV:
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_domain_ndrv_total);
+               break;
+       case PF_KEY:
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_domain_key_total);
+               break;
+       case PF_INET6:
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_domain_inet6_total);
+               if (type == SOCK_STREAM) {
+                       INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_inet6_stream_total);
+               } else {
+                       INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_inet6_dgram_total);
+               }
+               break;
+       case PF_SYSTEM:
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_domain_system_total);
+               break;
+       case PF_MULTIPATH:
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_domain_multipath_total);
+               break;
+       default:
+               INC_ATOMIC_INT64_LIM(net_api_stats.nas_socket_domain_other_total);
+               break;
+       }
 
-       if (flags & SOCF_ASYNC)
+       if (flags & SOCF_MPTCP) {
                so->so_state |= SS_NBIO;
-#if MULTIPATH
-       if (flags & SOCF_MP_SUBFLOW) {
-               /*
-                * A multipath subflow socket is used internally in the kernel,
-                * therefore it does not have a file desciptor associated by
-                * default.
-                */
-               so->so_state |= SS_NOFDREF;
-               so->so_flags |= SOF_MP_SUBFLOW;
        }
-#endif /* MULTIPATH */
 
        TAILQ_INIT(&so->so_incomp);
        TAILQ_INIT(&so->so_comp);
        so->so_type = type;
        so->last_upid = proc_uniqueid(p);
        so->last_pid = proc_pid(p);
-       proc_getexecutableuuid(p, so->last_uuid, sizeof (so->last_uuid));
+       proc_getexecutableuuid(p, so->last_uuid, sizeof(so->last_uuid));
        proc_pidoriginatoruuid(so->so_vuuid, sizeof(so->so_vuuid));
 
        if (ep != PROC_NULL && ep != p) {
                so->e_upid = proc_uniqueid(ep);
                so->e_pid = proc_pid(ep);
-               proc_getexecutableuuid(ep, so->e_uuid, sizeof (so->e_uuid));
+               proc_getexecutableuuid(ep, so->e_uuid, sizeof(so->e_uuid));
                so->so_flags |= SOF_DELEGATED;
+#if defined(XNU_TARGET_OS_OSX)
+               if (ep->p_responsible_pid != so->e_pid) {
+                       rpid = ep->p_responsible_pid;
+               }
+#endif
+       }
+
+#if defined(XNU_TARGET_OS_OSX)
+       if (rpid < 0 && p->p_responsible_pid != so->last_pid) {
+               rpid = p->p_responsible_pid;
        }
 
+       so->so_rpid = -1;
+       uuid_clear(so->so_ruuid);
+       if (rpid >= 0) {
+               proc_t rp = proc_find(rpid);
+               if (rp != PROC_NULL) {
+                       proc_getexecutableuuid(rp, so->so_ruuid, sizeof(so->so_ruuid));
+                       so->so_rpid = rpid;
+                       proc_rele(rp);
+               }
+       }
+#endif
+
        so->so_cred = kauth_cred_proc_ref(p);
-       if (!suser(kauth_cred_get(), NULL))
+       if (!suser(kauth_cred_get(), NULL)) {
                so->so_state |= SS_PRIV;
+       }
 
        so->so_proto = prp;
        so->so_rcv.sb_flags |= SB_RECV;
@@ -734,10 +771,6 @@ socreate_internal(int dom, struct socket **aso, int type, int proto,
        so->next_lock_lr = 0;
        so->next_unlock_lr = 0;
 
-#if CONFIG_MACF_SOCKET
-       mac_socket_label_associate(kauth_cred_get(), so);
-#endif /* MAC_SOCKET */
-
        /*
         * Attachment will create the per pcb lock if necessary and
         * increase refcount for creation, make sure it's done before
@@ -753,19 +786,27 @@ socreate_internal(int dom, struct socket **aso, int type, int proto,
                 * so protocol attachment handler must be coded carefuly
                 */
                so->so_state |= SS_NOFDREF;
+               VERIFY(so->so_usecount > 0);
                so->so_usecount--;
-               sofreelastref(so, 1);   /* will deallocate the socket */
-               return (error);
+               sofreelastref(so, 1);   /* will deallocate the socket */
+               return error;
+       }
+
+       /*
+        * Note: needs so_pcb to be set after pru_attach
+        */
+       if (prp->pr_update_last_owner != NULL) {
+               (*prp->pr_update_last_owner)(so, p, ep);
        }
 
        atomic_add_32(&prp->pr_domain->dom_refs, 1);
-       TAILQ_INIT(&so->so_evlist);
 
        /* Attach socket filters for this protocol */
        sflt_initsock(so);
 #if TCPDEBUG
-       if (tcpconsdebug == 2)
+       if (tcpconsdebug == 2) {
                so->so_options |= SO_DEBUG;
+       }
 #endif
        so_set_default_traffic_class(so);
 
@@ -773,20 +814,19 @@ socreate_internal(int dom, struct socket **aso, int type, int proto,
         * If this thread or task is marked to create backgrounded sockets,
         * mark the socket as background.
         */
-       if (proc_get_effective_thread_policy(current_thread(),
-           TASK_POLICY_NEW_SOCKETS_BG)) {
+       if (!(flags & SOCF_MPTCP) &&
+           proc_get_effective_thread_policy(current_thread(), TASK_POLICY_NEW_SOCKETS_BG)) {
                socket_set_traffic_mgt_flags(so, TRAFFIC_MGT_SO_BACKGROUND);
                so->so_background_thread = current_thread();
        }
 
        switch (dom) {
        /*
-        * Don't mark Unix domain, system or multipath sockets as
+        * Don't mark Unix domain or system
         * eligible for defunct by default.
         */
        case PF_LOCAL:
        case PF_SYSTEM:
-       case PF_MULTIPATH:
                so->so_flags |= SOF_NODEFUNCT;
                break;
        default:
@@ -806,7 +846,7 @@ socreate_internal(int dom, struct socket **aso, int type, int proto,
 
        *aso = so;
 
-       return (0);
+       return 0;
 }
 
 /*
@@ -823,8 +863,8 @@ socreate_internal(int dom, struct socket **aso, int type, int proto,
 int
 socreate(int dom, struct socket **aso, int type, int proto)
 {
-       return (socreate_internal(dom, aso, type, proto, current_proc(), 0,
-           PROC_NULL));
+       return socreate_internal(dom, aso, type, proto, current_proc(), 0,
+                  PROC_NULL);
 }
 
 int
@@ -845,10 +885,11 @@ socreate_delegate(int dom, struct socket **aso, int type, int proto, pid_t epid)
         * socreate_internal since it calls soalloc with M_WAITOK
         */
 done:
-       if (ep != PROC_NULL)
+       if (ep != PROC_NULL) {
                proc_rele(ep);
+       }
 
-       return (error);
+       return error;
 }
 
 /*
@@ -879,9 +920,9 @@ sobindlock(struct socket *so, struct sockaddr *nam, int dolock)
        struct proc *p = current_proc();
        int error = 0;
 
-       if (dolock)
+       if (dolock) {
                socket_lock(so, 1);
-       VERIFY(so->so_usecount > 1);
+       }
 
        so_update_last_owner_locked(so, p);
        so_update_policy(so);
@@ -906,16 +947,19 @@ sobindlock(struct socket *so, struct sockaddr *nam, int dolock)
        /* Socket filter */
        error = sflt_bind(so, nam);
 
-       if (error == 0)
+       if (error == 0) {
                error = (*so->so_proto->pr_usrreqs->pru_bind)(so, nam, p);
+       }
 out:
-       if (dolock)
+       if (dolock) {
                socket_unlock(so, 1);
+       }
 
-       if (error == EJUSTRETURN)
+       if (error == EJUSTRETURN) {
                error = 0;
+       }
 
-       return (error);
+       return error;
 }
 
 void
@@ -930,23 +974,12 @@ sodealloc(struct socket *so)
        cfil_sock_detach(so);
 #endif /* CONTENT_FILTER */
 
-       /* Delete the state allocated for msg queues on a socket */
-       if (so->so_flags & SOF_ENABLE_MSGS) {
-               FREE(so->so_msg_state, M_TEMP);
-               so->so_msg_state = NULL;
-       }
-       VERIFY(so->so_msg_state == NULL);
-
        so->so_gencnt = OSIncrementAtomic64((SInt64 *)&so_gencnt);
 
-#if CONFIG_MACF_SOCKET
-       mac_socket_label_destroy(so);
-#endif /* MAC_SOCKET */
-
        if (so->so_flags1 & SOF1_CACHED_IN_SOCK_LAYER) {
                cached_sock_free(so);
        } else {
-               FREE_ZONE(so, sizeof (*so), so->so_zone);
+               zfree(socket_zone, so);
        }
 }
 
@@ -999,7 +1032,7 @@ solisten(struct socket *so, int backlog)
         * reject the request now.
         */
        if ((so->so_state &
-           (SS_ISCONNECTED|SS_ISCONNECTING|SS_ISDISCONNECTING)) ||
+           (SS_ISCONNECTED | SS_ISCONNECTING | SS_ISDISCONNECTING)) ||
            (so->so_flags & SOF_DEFUNCT)) {
                error = EINVAL;
                if (so->so_flags & SOF_DEFUNCT) {
@@ -1018,17 +1051,20 @@ solisten(struct socket *so, int backlog)
        }
 
        error = sflt_listen(so);
-       if (error == 0)
+       if (error == 0) {
                error = (*so->so_proto->pr_usrreqs->pru_listen)(so, p);
+       }
 
        if (error) {
-               if (error == EJUSTRETURN)
+               if (error == EJUSTRETURN) {
                        error = 0;
+               }
                goto out;
        }
 
-       if (TAILQ_EMPTY(&so->so_comp))
+       if (TAILQ_EMPTY(&so->so_comp)) {
                so->so_options |= SO_ACCEPTCONN;
+       }
        /*
         * POSIX: The implementation may have an upper limit on the length of
         * the listen queue-either global or per accepting socket. If backlog
@@ -1043,13 +1079,83 @@ solisten(struct socket *so, int backlog)
         * in which case the length of the listen queue may be set to an
         * implementation-defined minimum value.
         */
-       if (backlog <= 0 || backlog > somaxconn)
+       if (backlog <= 0 || backlog > somaxconn) {
                backlog = somaxconn;
+       }
 
        so->so_qlimit = backlog;
 out:
        socket_unlock(so, 1);
-       return (error);
+       return error;
+}
+
+/*
+ * The "accept list lock" protects the fields related to the listener queues
+ * because we can unlock a socket to respect the lock ordering between
+ * the listener socket and its clients sockets. The lock ordering is first to
+ * acquire the client socket before the listener socket.
+ *
+ * The accept list lock serializes access to the following fields:
+ * - of the listener socket:
+ *   - so_comp
+ *   - so_incomp
+ *   - so_qlen
+ *   - so_inqlen
+ * - of client sockets that are in so_comp or so_incomp:
+ *   - so_head
+ *   - so_list
+ *
+ * As one can see the accept list lock protects the consistent of the
+ * linkage of the client sockets.
+ *
+ * Note that those fields may be read without holding the accept list lock
+ * for a preflight provided the accept list lock is taken when committing
+ * to take an action based on the result of the preflight. The preflight
+ * saves the cost of doing the unlock/lock dance.
+ */
+void
+so_acquire_accept_list(struct socket *head, struct socket *so)
+{
+       lck_mtx_t *mutex_held;
+
+       if (head->so_proto->pr_getlock == NULL) {
+               return;
+       }
+       mutex_held = (*head->so_proto->pr_getlock)(head, PR_F_WILLUNLOCK);
+       LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
+
+       if (!(head->so_flags1 & SOF1_ACCEPT_LIST_HELD)) {
+               head->so_flags1 |= SOF1_ACCEPT_LIST_HELD;
+               return;
+       }
+       if (so != NULL) {
+               socket_unlock(so, 0);
+       }
+       while (head->so_flags1 & SOF1_ACCEPT_LIST_HELD) {
+               so_accept_list_waits += 1;
+               msleep((caddr_t)&head->so_incomp, mutex_held,
+                   PSOCK | PCATCH, __func__, NULL);
+       }
+       head->so_flags1 |= SOF1_ACCEPT_LIST_HELD;
+       if (so != NULL) {
+               socket_unlock(head, 0);
+               socket_lock(so, 0);
+               socket_lock(head, 0);
+       }
+}
+
+void
+so_release_accept_list(struct socket *head)
+{
+       if (head->so_proto->pr_getlock != NULL) {
+               lck_mtx_t *mutex_held;
+
+               mutex_held = (*head->so_proto->pr_getlock)(head, 0);
+               LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
+
+               head->so_flags1 &= ~SOF1_ACCEPT_LIST_HELD;
+               wakeup((caddr_t)&head->so_incomp);
+       }
 }
 
 void
@@ -1062,17 +1168,36 @@ sofreelastref(struct socket *so, int dealloc)
        if (!(so->so_flags & SOF_PCBCLEARING) || !(so->so_state & SS_NOFDREF)) {
                selthreadclear(&so->so_snd.sb_sel);
                selthreadclear(&so->so_rcv.sb_sel);
-               so->so_rcv.sb_flags &= ~(SB_SEL|SB_UPCALL);
-               so->so_snd.sb_flags &= ~(SB_SEL|SB_UPCALL);
+               so->so_rcv.sb_flags &= ~(SB_SEL | SB_UPCALL);
+               so->so_snd.sb_flags &= ~(SB_SEL | SB_UPCALL);
                so->so_event = sonullevent;
                return;
        }
        if (head != NULL) {
-               socket_lock(head, 1);
+               /*
+                * Need to lock the listener when the protocol has
+                * per socket locks
+                */
+               if (head->so_proto->pr_getlock != NULL) {
+                       socket_lock(head, 1);
+                       so_acquire_accept_list(head, so);
+               }
                if (so->so_state & SS_INCOMP) {
+                       so->so_state &= ~SS_INCOMP;
                        TAILQ_REMOVE(&head->so_incomp, so, so_list);
                        head->so_incqlen--;
+                       head->so_qlen--;
+                       so->so_head = NULL;
+
+                       if (head->so_proto->pr_getlock != NULL) {
+                               so_release_accept_list(head);
+                               socket_unlock(head, 1);
+                       }
                } else if (so->so_state & SS_COMP) {
+                       if (head->so_proto->pr_getlock != NULL) {
+                               so_release_accept_list(head);
+                               socket_unlock(head, 1);
+                       }
                        /*
                         * We must not decommission a socket that's
                         * on the accept(2) queue.  If we do, then
@@ -1081,18 +1206,17 @@ sofreelastref(struct socket *so, int dealloc)
                         */
                        selthreadclear(&so->so_snd.sb_sel);
                        selthreadclear(&so->so_rcv.sb_sel);
-                       so->so_rcv.sb_flags &= ~(SB_SEL|SB_UPCALL);
-                       so->so_snd.sb_flags &= ~(SB_SEL|SB_UPCALL);
+                       so->so_rcv.sb_flags &= ~(SB_SEL | SB_UPCALL);
+                       so->so_snd.sb_flags &= ~(SB_SEL | SB_UPCALL);
                        so->so_event = sonullevent;
-                       socket_unlock(head, 1);
                        return;
                } else {
-                       panic("sofree: not queued");
+                       if (head->so_proto->pr_getlock != NULL) {
+                               so_release_accept_list(head);
+                               socket_unlock(head, 1);
+                       }
+                       printf("sofree: not queued\n");
                }
-               head->so_qlen--;
-               so->so_state &= ~SS_INCOMP;
-               so->so_head = NULL;
-               socket_unlock(head, 1);
        }
        sowflush(so);
        sorflush(so);
@@ -1101,15 +1225,16 @@ sofreelastref(struct socket *so, int dealloc)
        if (so->so_flags & SOF_FLOW_DIVERT) {
                flow_divert_detach(so);
        }
-#endif /* FLOW_DIVERT */
+#endif  /* FLOW_DIVERT */
 
        /* 3932268: disable upcall */
        so->so_rcv.sb_flags &= ~SB_UPCALL;
-       so->so_snd.sb_flags &= ~(SB_UPCALL|SB_SNDBYTE_CNT);
+       so->so_snd.sb_flags &= ~(SB_UPCALL | SB_SNDBYTE_CNT);
        so->so_event = sonullevent;
 
-       if (dealloc)
+       if (dealloc) {
                sodealloc(so);
+       }
 }
 
 void
@@ -1117,24 +1242,27 @@ soclose_wait_locked(struct socket *so)
 {
        lck_mtx_t *mutex_held;
 
-       if (so->so_proto->pr_getlock != NULL)
-               mutex_held = (*so->so_proto->pr_getlock)(so, 0);
-       else
+       if (so->so_proto->pr_getlock != NULL) {
+               mutex_held = (*so->so_proto->pr_getlock)(so, PR_F_WILLUNLOCK);
+       } else {
                mutex_held = so->so_proto->pr_domain->dom_mtx;
-       lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
+       }
+       LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
 
        /*
         * Double check here and return if there's no outstanding upcall;
         * otherwise proceed further only if SOF_UPCALLCLOSEWAIT is set.
         */
-       if (!so->so_upcallusecount || !(so->so_flags & SOF_UPCALLCLOSEWAIT))
+       if (!so->so_upcallusecount || !(so->so_flags & SOF_UPCALLCLOSEWAIT)) {
                return;
+       }
        so->so_rcv.sb_flags &= ~SB_UPCALL;
        so->so_snd.sb_flags &= ~SB_UPCALL;
        so->so_flags |= SOF_CLOSEWAIT;
+
        (void) msleep((caddr_t)&so->so_upcallusecount, mutex_held, (PZERO - 1),
            "soclose_wait_locked", NULL);
-       lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
+       LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
        so->so_flags &= ~SOF_CLOSEWAIT;
 }
 
@@ -1147,7 +1275,6 @@ int
 soclose_locked(struct socket *so)
 {
        int error = 0;
-       lck_mtx_t *mutex_held;
        struct timespec ts;
 
        if (so->so_usecount == 0) {
@@ -1157,8 +1284,9 @@ soclose_locked(struct socket *so)
 
        sflt_notify(so, sock_evt_closing, NULL);
 
-       if (so->so_upcallusecount)
+       if (so->so_upcallusecount) {
                soclose_wait_locked(so);
+       }
 
 #if CONTENT_FILTER
        /*
@@ -1178,7 +1306,8 @@ soclose_locked(struct socket *so)
 
        if ((so->so_options & SO_ACCEPTCONN)) {
                struct socket *sp, *sonext;
-               int socklock = 0;
+               int persocklock = 0;
+               int incomp_overflow_only;
 
                /*
                 * We do not want new connection to be added
@@ -1186,10 +1315,19 @@ soclose_locked(struct socket *so)
                 */
                so->so_options &= ~SO_ACCEPTCONN;
 
-               for (sp = TAILQ_FIRST(&so->so_incomp);
-                   sp != NULL; sp = sonext) {
-                       sonext = TAILQ_NEXT(sp, so_list);
+               /*
+                * We can drop the lock on the listener once
+                * we've acquired the incoming list
+                */
+               if (so->so_proto->pr_getlock != NULL) {
+                       persocklock = 1;
+                       so_acquire_accept_list(so, NULL);
+                       socket_unlock(so, 0);
+               }
+again:
+               incomp_overflow_only = 1;
 
+               TAILQ_FOREACH_SAFE(sp, &so->so_incomp, so_list, sonext) {
                        /*
                         * Radar 5350314
                         * skip sockets thrown away by tcpdropdropblreq
@@ -1197,57 +1335,81 @@ soclose_locked(struct socket *so)
                         * otherwise, remove the incomp socket from the queue
                         * and let soabort trigger the appropriate cleanup.
                         */
-                       if (sp->so_flags & SOF_OVERFLOW)
+                       if (sp->so_flags & SOF_OVERFLOW) {
                                continue;
+                       }
 
-                       if (so->so_proto->pr_getlock != NULL) {
-                               /*
-                                * Lock ordering for consistency with the
-                                * rest of the stack, we lock the socket
-                                * first and then grabb the head.
-                                */
-                               socket_unlock(so, 0);
+                       if (persocklock != 0) {
                                socket_lock(sp, 1);
-                               socket_lock(so, 0);
-                               socklock = 1;
                        }
 
-                       TAILQ_REMOVE(&so->so_incomp, sp, so_list);
-                       so->so_incqlen--;
-
+                       /*
+                        * Radar 27945981
+                        * The extra reference for the list insure the
+                        * validity of the socket pointer when we perform the
+                        * unlock of the head above
+                        */
                        if (sp->so_state & SS_INCOMP) {
                                sp->so_state &= ~SS_INCOMP;
                                sp->so_head = NULL;
+                               TAILQ_REMOVE(&so->so_incomp, sp, so_list);
+                               so->so_incqlen--;
+                               so->so_qlen--;
 
                                (void) soabort(sp);
+                       } else {
+                               panic("%s sp %p in so_incomp but !SS_INCOMP",
+                                   __func__, sp);
                        }
 
-                       if (socklock)
+                       if (persocklock != 0) {
                                socket_unlock(sp, 1);
+                       }
                }
 
-               while ((sp = TAILQ_FIRST(&so->so_comp)) != NULL) {
+               TAILQ_FOREACH_SAFE(sp, &so->so_comp, so_list, sonext) {
                        /* Dequeue from so_comp since sofree() won't do it */
-                       TAILQ_REMOVE(&so->so_comp, sp, so_list);
-                       so->so_qlen--;
-
-                       if (so->so_proto->pr_getlock != NULL) {
-                               socket_unlock(so, 0);
+                       if (persocklock != 0) {
                                socket_lock(sp, 1);
                        }
 
                        if (sp->so_state & SS_COMP) {
                                sp->so_state &= ~SS_COMP;
                                sp->so_head = NULL;
+                               TAILQ_REMOVE(&so->so_comp, sp, so_list);
+                               so->so_qlen--;
 
                                (void) soabort(sp);
+                       } else {
+                               panic("%s sp %p in so_comp but !SS_COMP",
+                                   __func__, sp);
                        }
 
-                       if (so->so_proto->pr_getlock != NULL) {
+                       if (persocklock) {
                                socket_unlock(sp, 1);
-                               socket_lock(so, 0);
                        }
                }
+
+               if (incomp_overflow_only == 0 && !TAILQ_EMPTY(&so->so_incomp)) {
+#if (DEBUG | DEVELOPMENT)
+                       panic("%s head %p so_comp not empty\n", __func__, so);
+#endif /* (DEVELOPMENT || DEBUG) */
+
+                       goto again;
+               }
+
+               if (!TAILQ_EMPTY(&so->so_comp)) {
+#if (DEBUG | DEVELOPMENT)
+                       panic("%s head %p so_comp not empty\n", __func__, so);
+#endif /* (DEVELOPMENT || DEBUG) */
+
+                       goto again;
+               }
+
+               if (persocklock) {
+                       socket_lock(so, 0);
+                       so_release_accept_list(so);
+               }
        }
        if (so->so_pcb == NULL) {
                /* 3915887: mark the socket as ready for dealloc */
@@ -1257,19 +1419,24 @@ soclose_locked(struct socket *so)
        if (so->so_state & SS_ISCONNECTED) {
                if ((so->so_state & SS_ISDISCONNECTING) == 0) {
                        error = sodisconnectlocked(so);
-                       if (error)
+                       if (error) {
                                goto drop;
+                       }
                }
                if (so->so_options & SO_LINGER) {
+                       lck_mtx_t *mutex_held;
+
                        if ((so->so_state & SS_ISDISCONNECTING) &&
-                           (so->so_state & SS_NBIO))
+                           (so->so_state & SS_NBIO)) {
                                goto drop;
-                       if (so->so_proto->pr_getlock != NULL)
-                               mutex_held = (*so->so_proto->pr_getlock)(so, 0);
-                       else
+                       }
+                       if (so->so_proto->pr_getlock != NULL) {
+                               mutex_held = (*so->so_proto->pr_getlock)(so, PR_F_WILLUNLOCK);
+                       } else {
                                mutex_held = so->so_proto->pr_domain->dom_mtx;
+                       }
                        while (so->so_state & SS_ISCONNECTED) {
-                               ts.tv_sec = (so->so_linger/100);
+                               ts.tv_sec = (so->so_linger / 100);
                                ts.tv_nsec = (so->so_linger % 100) *
                                    NSEC_PER_USEC * 1000 * 10;
                                error = msleep((caddr_t)&so->so_timeo,
@@ -1279,8 +1446,9 @@ soclose_locked(struct socket *so)
                                         * It's OK when the time fires,
                                         * don't report an error
                                         */
-                                       if (error == EWOULDBLOCK)
+                                       if (error == EWOULDBLOCK) {
                                                error = 0;
+                                       }
                                        break;
                                }
                        }
@@ -1293,8 +1461,9 @@ drop:
        }
        if (so->so_pcb != NULL && !(so->so_flags & SOF_PCBCLEARING)) {
                int error2 = (*so->so_proto->pr_usrreqs->pru_detach)(so);
-               if (error == 0)
+               if (error == 0) {
                        error = error2;
+               }
        }
        if (so->so_usecount <= 0) {
                panic("soclose: usecount is zero so=%p\n", so);
@@ -1308,18 +1477,16 @@ discard:
        }
        so->so_state |= SS_NOFDREF;
 
-       if (so->so_flags & SOF_MP_SUBFLOW)
-               so->so_flags &= ~SOF_MP_SUBFLOW;
-
-       if ((so->so_flags & SOF_KNOTE) != 0)
+       if ((so->so_flags & SOF_KNOTE) != 0) {
                KNOTE(&so->so_klist, SO_FILT_HINT_LOCKED);
+       }
 
        atomic_add_32(&so->so_proto->pr_domain->dom_refs, -1);
-       evsofree(so);
 
+       VERIFY(so->so_usecount > 0);
        so->so_usecount--;
        sofree(so);
-       return (error);
+       return error;
 }
 
 int
@@ -1336,12 +1503,13 @@ soclose(struct socket *so)
                 * retained in kernel remove its reference
                 */
                so->so_usecount--;
-               if (so->so_usecount < 2)
+               if (so->so_usecount < 2) {
                        panic("soclose: retaincnt non null and so=%p "
                            "usecount=%d\n", so, so->so_usecount);
+               }
        }
        socket_unlock(so, 1);
-       return (error);
+       return error;
 }
 
 /*
@@ -1356,11 +1524,12 @@ soabort(struct socket *so)
 #ifdef MORE_LOCKING_DEBUG
        lck_mtx_t *mutex_held;
 
-       if (so->so_proto->pr_getlock != NULL)
+       if (so->so_proto->pr_getlock != NULL) {
                mutex_held = (*so->so_proto->pr_getlock)(so, 0);
-       else
+       } else {
                mutex_held = so->so_proto->pr_domain->dom_mtx;
-       lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
+       }
+       LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
 #endif
 
        if ((so->so_flags & SOF_ABORTED) == 0) {
@@ -1368,10 +1537,10 @@ soabort(struct socket *so)
                error = (*so->so_proto->pr_usrreqs->pru_abort)(so);
                if (error) {
                        sofree(so);
-                       return (error);
+                       return error;
                }
        }
-       return (0);
+       return 0;
 }
 
 int
@@ -1379,8 +1548,9 @@ soacceptlock(struct socket *so, struct sockaddr **nam, int dolock)
 {
        int error;
 
-       if (dolock)
+       if (dolock) {
                socket_lock(so, 1);
+       }
 
        so_update_last_owner_locked(so, PROC_NULL);
        so_update_policy(so);
@@ -1388,28 +1558,29 @@ soacceptlock(struct socket *so, struct sockaddr **nam, int dolock)
        so_update_necp_policy(so, NULL, NULL);
 #endif /* NECP */
 
-       if ((so->so_state & SS_NOFDREF) == 0)
+       if ((so->so_state & SS_NOFDREF) == 0) {
                panic("soaccept: !NOFDREF");
+       }
        so->so_state &= ~SS_NOFDREF;
        error = (*so->so_proto->pr_usrreqs->pru_accept)(so, nam);
 
-       if (dolock)
+       if (dolock) {
                socket_unlock(so, 1);
-       return (error);
+       }
+       return error;
 }
 
 int
 soaccept(struct socket *so, struct sockaddr **nam)
 {
-       return (soacceptlock(so, nam, 1));
+       return soacceptlock(so, nam, 1);
 }
 
 int
-soacceptfilter(struct socket *so)
+soacceptfilter(struct socket *so, struct socket *head)
 {
        struct sockaddr *local = NULL, *remote = NULL;
        int error = 0;
-       struct socket *head = so->so_head;
 
        /*
         * Hold the lock even if this socket has not been made visible
@@ -1419,8 +1590,7 @@ soacceptfilter(struct socket *so)
        socket_lock(so, 1);
        if (sogetaddr_locked(so, &remote, 1) != 0 ||
            sogetaddr_locked(so, &local, 0) != 0) {
-               so->so_state &= ~(SS_NOFDREF | SS_COMP);
-               so->so_head = NULL;
+               so->so_state &= ~SS_NOFDREF;
                socket_unlock(so, 1);
                soclose(so);
                /* Out of resources; try it again next time */
@@ -1448,8 +1618,7 @@ soacceptfilter(struct socket *so)
                 * the following is done while holding the lock since
                 * the socket has been exposed to the filter(s) earlier.
                 */
-               so->so_state &= ~(SS_NOFDREF | SS_COMP);
-               so->so_head = NULL;
+               so->so_state &= ~SS_NOFDREF;
                socket_unlock(so, 1);
                soclose(so);
                /* Propagate socket filter's error code to the caller */
@@ -1460,7 +1629,7 @@ done:
        /* Callee checks for NULL pointer */
        sock_freeaddr(remote);
        sock_freeaddr(local);
-       return (error);
+       return error;
 }
 
 /*
@@ -1482,8 +1651,9 @@ soconnectlock(struct socket *so, struct sockaddr *nam, int dolock)
        int error;
        struct proc *p = current_proc();
 
-       if (dolock)
+       if (dolock) {
                socket_lock(so, 1);
+       }
 
        so_update_last_owner_locked(so, p);
        so_update_policy(so);
@@ -1505,15 +1675,17 @@ soconnectlock(struct socket *so, struct sockaddr *nam, int dolock)
                            (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
                            SOCK_DOM(so), SOCK_TYPE(so), error);
                }
-               if (dolock)
+               if (dolock) {
                        socket_unlock(so, 1);
-               return (error);
+               }
+               return error;
        }
 
        if ((so->so_restrictions & SO_RESTRICT_DENY_OUT) != 0) {
-               if (dolock)
+               if (dolock) {
                        socket_unlock(so, 1);
-               return (EPERM);
+               }
+               return EPERM;
        }
 
        /*
@@ -1522,7 +1694,7 @@ soconnectlock(struct socket *so, struct sockaddr *nam, int dolock)
         * This allows user to disconnect by connecting to, e.g.,
         * a null address.
         */
-       if (so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING) &&
+       if (so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING) &&
            ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
            (error = sodisconnectlocked(so)))) {
                error = EISCONN;
@@ -1533,22 +1705,27 @@ soconnectlock(struct socket *so, struct sockaddr *nam, int dolock)
                 */
                error = sflt_connectout(so, nam);
                if (error != 0) {
-                       if (error == EJUSTRETURN)
+                       if (error == EJUSTRETURN) {
                                error = 0;
+                       }
                } else {
                        error = (*so->so_proto->pr_usrreqs->pru_connect)
                            (so, nam, p);
+                       if (error != 0) {
+                               so->so_state &= ~SS_ISCONNECTING;
+                       }
                }
        }
-       if (dolock)
+       if (dolock) {
                socket_unlock(so, 1);
-       return (error);
+       }
+       return error;
 }
 
 int
 soconnect(struct socket *so, struct sockaddr *nam)
 {
-       return (soconnectlock(so, nam, 1));
+       return soconnectlock(so, nam, 1);
 }
 
 /*
@@ -1565,20 +1742,22 @@ soconnect2(struct socket *so1, struct socket *so2)
        int error;
 
        socket_lock(so1, 1);
-       if (so2->so_proto->pr_lock)
+       if (so2->so_proto->pr_lock) {
                socket_lock(so2, 1);
+       }
 
        error = (*so1->so_proto->pr_usrreqs->pru_connect2)(so1, so2);
 
        socket_unlock(so1, 1);
-       if (so2->so_proto->pr_lock)
+       if (so2->so_proto->pr_lock) {
                socket_unlock(so2, 1);
-       return (error);
+       }
+       return error;
 }
 
 int
-soconnectxlocked(struct socket *so, struct sockaddr_list **src_sl,
-    struct sockaddr_list **dst_sl, struct proc *p, uint32_t ifscope,
+soconnectxlocked(struct socket *so, struct sockaddr *src,
+    struct sockaddr *dst, struct proc *p, uint32_t ifscope,
     sae_associd_t aid, sae_connid_t *pcid, uint32_t flags, void *arg,
     uint32_t arglen, uio_t auio, user_ssize_t *bytes_written)
 {
@@ -1600,11 +1779,12 @@ soconnectxlocked(struct socket *so, struct sockaddr_list **src_sl,
                            (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
                            SOCK_DOM(so), SOCK_TYPE(so), error);
                }
-               return (error);
+               return error;
        }
 
-       if ((so->so_restrictions & SO_RESTRICT_DENY_OUT) != 0)
-               return (EPERM);
+       if ((so->so_restrictions & SO_RESTRICT_DENY_OUT) != 0) {
+               return EPERM;
+       }
 
        /*
         * If protocol is connection-based, can only connect once
@@ -1612,30 +1792,70 @@ soconnectxlocked(struct socket *so, struct sockaddr_list **src_sl,
         * try to disconnect first.  This allows user to disconnect
         * by connecting to, e.g., a null address.
         */
-       if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) &&
+       if ((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING)) &&
            !(so->so_proto->pr_flags & PR_MULTICONN) &&
            ((so->so_proto->pr_flags & PR_CONNREQUIRED) ||
            (error = sodisconnectlocked(so)) != 0)) {
                error = EISCONN;
        } else {
+               if ((so->so_proto->pr_flags & PR_DATA_IDEMPOTENT) &&
+                   (flags & CONNECT_DATA_IDEMPOTENT)) {
+                       so->so_flags1 |= SOF1_DATA_IDEMPOTENT;
+
+                       if (flags & CONNECT_DATA_AUTHENTICATED) {
+                               so->so_flags1 |= SOF1_DATA_AUTHENTICATED;
+                       }
+               }
+
+               /*
+                * Case 1: CONNECT_RESUME_ON_READ_WRITE set, no data.
+                * Case 2: CONNECT_RESUME_ON_READ_WRITE set, with data (user error)
+                * Case 3: CONNECT_RESUME_ON_READ_WRITE not set, with data
+                * Case 3 allows user to combine write with connect even if they have
+                * no use for TFO (such as regular TCP, and UDP).
+                * Case 4: CONNECT_RESUME_ON_READ_WRITE not set, no data (regular case)
+                */
+               if ((so->so_proto->pr_flags & PR_PRECONN_WRITE) &&
+                   ((flags & CONNECT_RESUME_ON_READ_WRITE) || auio)) {
+                       so->so_flags1 |= SOF1_PRECONNECT_DATA;
+               }
+
+               /*
+                * If a user sets data idempotent and does not pass an uio, or
+                * sets CONNECT_RESUME_ON_READ_WRITE, this is an error, reset
+                * SOF1_DATA_IDEMPOTENT.
+                */
+               if (!(so->so_flags1 & SOF1_PRECONNECT_DATA) &&
+                   (so->so_flags1 & SOF1_DATA_IDEMPOTENT)) {
+                       /* We should return EINVAL instead perhaps. */
+                       so->so_flags1 &= ~SOF1_DATA_IDEMPOTENT;
+               }
+
                /*
                 * Run connect filter before calling protocol:
                 *  - non-blocking connect returns before completion;
                 */
-               error = sflt_connectxout(so, dst_sl);
+               error = sflt_connectout(so, dst);
                if (error != 0) {
                        /* Disable PRECONNECT_DATA, as we don't need to send a SYN anymore. */
                        so->so_flags1 &= ~SOF1_PRECONNECT_DATA;
-                       if (error == EJUSTRETURN)
+                       if (error == EJUSTRETURN) {
                                error = 0;
+                       }
                } else {
                        error = (*so->so_proto->pr_usrreqs->pru_connectx)
-                           (so, src_sl, dst_sl, p, ifscope, aid, pcid,
+                           (so, src, dst, p, ifscope, aid, pcid,
                            flags, arg, arglen, auio, bytes_written);
+                       if (error != 0) {
+                               so->so_state &= ~SS_ISCONNECTING;
+                               if (error != EINPROGRESS) {
+                                       so->so_flags1 &= ~SOF1_PRECONNECT_DATA;
+                               }
+                       }
                }
        }
 
-       return (error);
+       return error;
 }
 
 int
@@ -1653,11 +1873,12 @@ sodisconnectlocked(struct socket *so)
        }
 
        error = (*so->so_proto->pr_usrreqs->pru_disconnect)(so);
-       if (error == 0)
+       if (error == 0) {
                sflt_notify(so, sock_evt_disconnected, NULL);
+       }
 
 bad:
-       return (error);
+       return error;
 }
 
 /* Locking version */
@@ -1669,7 +1890,7 @@ sodisconnect(struct socket *so)
        socket_lock(so, 1);
        error = sodisconnectlocked(so);
        socket_unlock(so, 1);
-       return (error);
+       return error;
 }
 
 int
@@ -1687,10 +1908,11 @@ sodisconnectxlocked(struct socket *so, sae_associd_t aid, sae_connid_t cid)
                 * The event applies only for the session, not for
                 * the disconnection of individual subflows.
                 */
-               if (so->so_state & (SS_ISDISCONNECTING|SS_ISDISCONNECTED))
+               if (so->so_state & (SS_ISDISCONNECTING | SS_ISDISCONNECTED)) {
                        sflt_notify(so, sock_evt_disconnected, NULL);
+               }
        }
-       return (error);
+       return error;
 }
 
 int
@@ -1701,16 +1923,10 @@ sodisconnectx(struct socket *so, sae_associd_t aid, sae_connid_t cid)
        socket_lock(so, 1);
        error = sodisconnectxlocked(so, aid, cid);
        socket_unlock(so, 1);
-       return (error);
-}
-
-int
-sopeelofflocked(struct socket *so, sae_associd_t aid, struct socket **psop)
-{
-       return ((*so->so_proto->pr_usrreqs->pru_peeloff)(so, aid, psop));
+       return error;
 }
 
-#define        SBLOCKWAIT(f)   (((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
+#define SBLOCKWAIT(f)   (((f) & MSG_DONTWAIT) ? 0 : SBL_WAIT)
 
 /*
  * sosendcheck will lock the socket buffer if it isn't locked and
@@ -1726,12 +1942,11 @@ sopeelofflocked(struct socket *so, sae_associd_t aid, struct socket **psop)
  */
 int
 sosendcheck(struct socket *so, struct sockaddr *addr, user_ssize_t resid,
-    int32_t clen, int32_t atomic, int flags, int *sblocked,
-    struct mbuf *control)
+    int32_t clen, int32_t atomic, int flags, int *sblocked)
 {
-       int     error = 0;
+       int     error = 0;
        int32_t space;
-       int     assumelock = 0;
+       int     assumelock = 0;
 
 restart:
        if (*sblocked == 0) {
@@ -1748,9 +1963,10 @@ restart:
                } else {
                        error = sblock(&so->so_snd, SBLOCKWAIT(flags));
                        if (error) {
-                               if (so->so_flags & SOF_DEFUNCT)
+                               if (so->so_flags & SOF_DEFUNCT) {
                                        goto defunct;
-                               return (error);
+                               }
+                               return error;
                        }
                        *sblocked = 1;
                }
@@ -1767,7 +1983,7 @@ defunct:
                    __func__, proc_selfpid(), proc_best_name(current_proc()),
                    (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
                    SOCK_DOM(so), SOCK_TYPE(so), error);
-               return (error);
+               return error;
        }
 
        if (so->so_state & SS_CANTSENDMORE) {
@@ -1776,19 +1992,19 @@ defunct:
                 * Can re-inject data of half closed connections
                 */
                if ((so->so_state & SS_ISDISCONNECTED) == 0 &&
-                       so->so_snd.sb_cfil_thread == current_thread() &&
-                       cfil_sock_data_pending(&so->so_snd) != 0)
+                   so->so_snd.sb_cfil_thread == current_thread() &&
+                   cfil_sock_data_pending(&so->so_snd) != 0) {
                        CFIL_LOG(LOG_INFO,
-                               "so %llx ignore SS_CANTSENDMORE",
-                               (uint64_t)DEBUG_KERNEL_ADDRPERM(so));
-               else
+                           "so %llx ignore SS_CANTSENDMORE",
+                           (uint64_t)DEBUG_KERNEL_ADDRPERM(so));
+               else
 #endif /* CONTENT_FILTER */
-                       return (EPIPE);
+               return EPIPE;
        }
        if (so->so_error) {
                error = so->so_error;
                so->so_error = 0;
-               return (error);
+               return error;
        }
 
        if ((so->so_state & SS_ISCONNECTED) == 0) {
@@ -1796,33 +2012,23 @@ defunct:
                        if (((so->so_state & SS_ISCONFIRMING) == 0) &&
                            (resid != 0 || clen == 0) &&
                            !(so->so_flags1 & SOF1_PRECONNECT_DATA)) {
-#if MPTCP
-                               /*
-                                * MPTCP Fast Join sends data before the
-                                * socket is truly connected.
-                                */
-                               if ((so->so_flags & (SOF_MP_SUBFLOW |
-                                       SOF_MPTCP_FASTJOIN)) !=
-                                   (SOF_MP_SUBFLOW | SOF_MPTCP_FASTJOIN))
-#endif /* MPTCP */
-                               return (ENOTCONN);
+                               return ENOTCONN;
                        }
-               } else if (addr == 0 && !(flags&MSG_HOLD)) {
-                       return ((so->so_proto->pr_flags & PR_CONNREQUIRED) ?
-                           ENOTCONN : EDESTADDRREQ);
+               } else if (addr == 0) {
+                       return (so->so_proto->pr_flags & PR_CONNREQUIRED) ?
+                              ENOTCONN : EDESTADDRREQ;
                }
        }
 
-       if (so->so_flags & SOF_ENABLE_MSGS)
-               space = msgq_sbspace(so, control);
-       else
-               space = sbspace(&so->so_snd);
+       space = sbspace(&so->so_snd);
 
-       if (flags & MSG_OOB)
+       if (flags & MSG_OOB) {
                space += 1024;
+       }
        if ((atomic && resid > so->so_snd.sb_hiwat) ||
-           clen > so->so_snd.sb_hiwat)
-               return (EMSGSIZE);
+           clen > so->so_snd.sb_hiwat) {
+               return EMSGSIZE;
+       }
 
        if ((space < resid + clen &&
            (atomic || (space < (int32_t)so->so_snd.sb_lowat) ||
@@ -1834,27 +2040,28 @@ defunct:
                 */
                if (so->so_flags1 & SOF1_PRECONNECT_DATA) {
                        if (space == 0) {
-                               return (EWOULDBLOCK);
+                               return EWOULDBLOCK;
                        }
                        if (space < (int32_t)so->so_snd.sb_lowat) {
-                               return (0);
+                               return 0;
                        }
                }
                if ((so->so_state & SS_NBIO) || (flags & MSG_NBIO) ||
                    assumelock) {
-                       return (EWOULDBLOCK);
+                       return EWOULDBLOCK;
                }
-               sbunlock(&so->so_snd, TRUE);    /* keep socket locked */
+               sbunlock(&so->so_snd, TRUE);    /* keep socket locked */
                *sblocked = 0;
                error = sbwait(&so->so_snd);
                if (error) {
-                       if (so->so_flags & SOF_DEFUNCT)
+                       if (so->so_flags & SOF_DEFUNCT) {
                                goto defunct;
-                       return (error);
+                       }
+                       return error;
                }
                goto restart;
        }
-       return (0);
+       return 0;
 }
 
 /*
@@ -1873,10 +2080,6 @@ defunct:
  * Returns nonzero on error, timeout or signal; callers
  * must check for short counts if EINTR/ERESTART are returned.
  * Data and control buffers are freed on return.
- * Experiment:
- * MSG_HOLD: go thru most of sosend(), but just enqueue the mbuf
- * MSG_SEND: go thru as for MSG_HOLD on current fragment, then
- *  point at the mbuf chain being constructed and go from there.
  *
  * Returns:    0                       Success
  *             EOPNOTSUPP
@@ -1928,14 +2131,14 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
        int atomic = sosendallatonce(so) || top;
        int sblocked = 0;
        struct proc *p = current_proc();
-       struct mbuf *control_copy = NULL;
        uint16_t headroom = 0;
        boolean_t en_tracing = FALSE;
 
-       if (uio != NULL)
+       if (uio != NULL) {
                resid = uio_resid(uio);
-       else
+       } else {
                resid = top->m_pkthdr.len;
+       }
 
        KERNEL_DEBUG((DBG_FNC_SOSEND | DBG_FUNC_START), so, resid,
            so->so_snd.sb_cc, so->so_snd.sb_lowat, so->so_snd.sb_hiwat);
@@ -1974,8 +2177,7 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
 
        if (so->so_type != SOCK_STREAM && (flags & MSG_OOB) != 0) {
                error = EOPNOTSUPP;
-               socket_unlock(so, 1);
-               goto out;
+               goto out_locked;
        }
 
        /*
@@ -1986,16 +2188,14 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
         * causes us to loop sending 0-length segments to the protocol.
         *
         * Usually, MSG_EOR isn't used on SOCK_STREAM type sockets.
-        * But it will be used by sockets doing message delivery.
         *
         * Note: We limit resid to be a positive int value as we use
         * imin() to set bytes_to_copy -- radr://14558484
         */
-       if (resid < 0 || resid > INT_MAX || (so->so_type == SOCK_STREAM &&
-           !(so->so_flags & SOF_ENABLE_MSGS) && (flags & MSG_EOR))) {
+       if (resid < 0 || resid > INT_MAX ||
+           (so->so_type == SOCK_STREAM && (flags & MSG_EOR))) {
                error = EINVAL;
-               socket_unlock(so, 1);
-               goto out;
+               goto out_locked;
        }
 
        dontroute = (flags & MSG_DONTROUTE) &&
@@ -2003,23 +2203,23 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
            (so->so_proto->pr_flags & PR_ATOMIC);
        OSIncrementAtomicLong(&p->p_stats->p_ru.ru_msgsnd);
 
-       if (control != NULL)
+       if (control != NULL) {
                clen = control->m_len;
+       }
 
-       if (soreserveheadroom != 0)
+       if (soreserveheadroom != 0) {
                headroom = so->so_pktheadroom;
+       }
 
        do {
                error = sosendcheck(so, addr, resid, clen, atomic, flags,
-                   &sblocked, control);
-               if (error)
-                       goto release;
+                   &sblocked);
+               if (error) {
+                       goto out_locked;
+               }
 
                mp = &top;
-               if (so->so_flags & SOF_ENABLE_MSGS)
-                       space = msgq_sbspace(so, control);
-               else
-                       space = sbspace(&so->so_snd) - clen;
+               space = sbspace(&so->so_snd) - clen;
                space += ((flags & MSG_OOB) ? 1024 : 0);
 
                do {
@@ -2028,8 +2228,9 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
                                 * Data is prepackaged in "top".
                                 */
                                resid = 0;
-                               if (flags & MSG_EOR)
+                               if (flags & MSG_EOR) {
                                        top->m_flags |= M_EOR;
+                               }
                        } else {
                                int chainlength;
                                int bytes_to_copy;
@@ -2040,13 +2241,15 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
                                bytes_to_copy = imin(resid, space);
 
                                bytes_to_alloc = bytes_to_copy;
-                               if (top == NULL)
+                               if (top == NULL) {
                                        bytes_to_alloc += headroom;
+                               }
 
-                               if (sosendminchain > 0)
+                               if (sosendminchain > 0) {
                                        chainlength = 0;
-                               else
+                               } else {
                                        chainlength = sosendmaxchain;
+                               }
 
                                /*
                                 * Use big 4 KB cluster when the outgoing interface
@@ -2095,14 +2298,15 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
 
                                                if ((bytes_to_alloc -
                                                    (num_needed * M16KCLBYTES))
-                                                   >= MINCLSIZE)
+                                                   >= MINCLSIZE) {
                                                        num_needed++;
+                                               }
 
                                                freelist =
                                                    m_getpackets_internal(
-                                                   (unsigned int *)&num_needed,
-                                                   hdrs_needed, M_WAIT, 0,
-                                                   M16KCLBYTES);
+                                                       (unsigned int *)&num_needed,
+                                                       hdrs_needed, M_WAIT, 0,
+                                                       M16KCLBYTES);
                                                /*
                                                 * Fall back to 4K cluster size
                                                 * if allocation failed
@@ -2117,14 +2321,15 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
 
                                                if ((bytes_to_alloc -
                                                    (num_needed * MBIGCLBYTES)) >=
-                                                   MINCLSIZE)
+                                                   MINCLSIZE) {
                                                        num_needed++;
+                                               }
 
                                                freelist =
                                                    m_getpackets_internal(
-                                                   (unsigned int *)&num_needed,
-                                                   hdrs_needed, M_WAIT, 0,
-                                                   MBIGCLBYTES);
+                                                       (unsigned int *)&num_needed,
+                                                       hdrs_needed, M_WAIT, 0,
+                                                       MBIGCLBYTES);
                                                /*
                                                 * Fall back to cluster size
                                                 * if allocation failed
@@ -2146,9 +2351,9 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
                                                    MCLBYTES;
                                                freelist =
                                                    m_getpackets_internal(
-                                                   (unsigned int *)&num_needed,
-                                                   hdrs_needed, M_WAIT, 0,
-                                                   MCLBYTES);
+                                                       (unsigned int *)&num_needed,
+                                                       hdrs_needed, M_WAIT, 0,
+                                                       MCLBYTES);
                                                /*
                                                 * Fall back to a single mbuf
                                                 * if allocation failed
@@ -2160,14 +2365,15 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
 
                                                if ((bytes_to_alloc -
                                                    (num_needed * MCLBYTES)) >=
-                                                   MINCLSIZE)
+                                                   MINCLSIZE) {
                                                        num_needed++;
+                                               }
 
                                                freelist =
                                                    m_getpackets_internal(
-                                                   (unsigned int *)&num_needed,
-                                                   hdrs_needed, M_WAIT, 0,
-                                                   MCLBYTES);
+                                                       (unsigned int *)&num_needed,
+                                                       hdrs_needed, M_WAIT, 0,
+                                                       MCLBYTES);
                                                /*
                                                 * Fall back to a single mbuf
                                                 * if allocation failed
@@ -2188,17 +2394,20 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
                                         * reserving the socket headroom
                                         */
                                        if (freelist == NULL) {
-                                               if (top == NULL)
-                                                       MGETHDR(freelist,
-                                                           M_WAIT, MT_DATA);
-                                               else
-                                                       MGET(freelist,
-                                                           M_WAIT, MT_DATA);
+                                               if (SOCK_TYPE(so) != SOCK_STREAM || bytes_to_alloc <= MINCLSIZE) {
+                                                       if (top == NULL) {
+                                                               MGETHDR(freelist,
+                                                                   M_WAIT, MT_DATA);
+                                                       } else {
+                                                               MGET(freelist,
+                                                                   M_WAIT, MT_DATA);
+                                                       }
+                                               }
 
                                                if (freelist == NULL) {
                                                        error = ENOBUFS;
                                                        socket_lock(so, 0);
-                                                       goto release;
+                                                       goto out_locked;
                                                }
                                                /*
                                                 * For datagram protocols,
@@ -2215,14 +2424,15 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
                                        freelist = m->m_next;
                                        m->m_next = NULL;
 
-                                       if ((m->m_flags & M_EXT))
+                                       if ((m->m_flags & M_EXT)) {
                                                mlen = m->m_ext.ext_size -
-                                                   m_leadingspace(m);
-                                       else if ((m->m_flags & M_PKTHDR))
+                                                   M_LEADINGSPACE(m);
+                                       } else if ((m->m_flags & M_PKTHDR)) {
                                                mlen =
-                                                   MHLEN - m_leadingspace(m);
-                                       else
-                                               mlen = MLEN - m_leadingspace(m);
+                                                   MHLEN - M_LEADINGSPACE(m);
+                                       } else {
+                                               mlen = MLEN - M_LEADINGSPACE(m);
+                                       }
                                        len = imin(mlen, bytes_to_copy);
 
                                        chainlength += len;
@@ -2237,49 +2447,31 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
                                        m->m_len = len;
                                        *mp = m;
                                        top->m_pkthdr.len += len;
-                                       if (error)
+                                       if (error) {
                                                break;
+                                       }
                                        mp = &m->m_next;
                                        if (resid <= 0) {
-                                               if (flags & MSG_EOR)
+                                               if (flags & MSG_EOR) {
                                                        top->m_flags |= M_EOR;
+                                               }
                                                break;
                                        }
                                        bytes_to_copy = min(resid, space);
-
                                } while (space > 0 &&
                                    (chainlength < sosendmaxchain || atomic ||
                                    resid < MINCLSIZE));
 
                                socket_lock(so, 0);
 
-                               if (error)
-                                       goto release;
-                       }
-
-                       if (flags & (MSG_HOLD|MSG_SEND)) {
-                               /* Enqueue for later, go away if HOLD */
-                               struct mbuf *mb1;
-                               if (so->so_temp && (flags & MSG_FLUSH)) {
-                                       m_freem(so->so_temp);
-                                       so->so_temp = NULL;
-                               }
-                               if (so->so_temp)
-                                       so->so_tail->m_next = top;
-                               else
-                                       so->so_temp = top;
-                               mb1 = top;
-                               while (mb1->m_next)
-                                       mb1 = mb1->m_next;
-                               so->so_tail = mb1;
-                               if (flags & MSG_HOLD) {
-                                       top = NULL;
-                                       goto release;
+                               if (error) {
+                                       goto out_locked;
                                }
-                               top = so->so_temp;
                        }
-                       if (dontroute)
+
+                       if (dontroute) {
                                so->so_options |= SO_DONTROUTE;
+                       }
 
                        /*
                         * Compute flags here, for pru_send and NKEs
@@ -2309,74 +2501,59 @@ sosend(struct socket *so, struct sockaddr *addr, struct uio *uio,
                                                control = NULL;
                                                top = NULL;
                                        }
-                                       goto release;
+                                       goto out_locked;
                                }
 #if CONTENT_FILTER
                                /*
                                 * Content filter processing
                                 */
                                error = cfil_sock_data_out(so, addr, top,
-                                   control, (sendflags & MSG_OOB) ?
-                                   sock_data_filt_flag_oob : 0);
+                                   control, sendflags);
                                if (error) {
                                        if (error == EJUSTRETURN) {
                                                error = 0;
                                                clen = 0;
                                                control = NULL;
                                                top = NULL;
-                                               }
-                                       goto release;
+                                       }
+                                       goto out_locked;
                                }
 #endif /* CONTENT_FILTER */
                        }
-                       if (so->so_flags & SOF_ENABLE_MSGS) {
-                               /*
-                                * Make a copy of control mbuf,
-                                * so that msg priority can be
-                                * passed to subsequent mbufs.
-                                */
-                               control_copy = m_dup(control, M_NOWAIT);
-                       }
                        error = (*so->so_proto->pr_usrreqs->pru_send)
                            (so, sendflags, top, addr, control, p);
 
-                       if (flags & MSG_SEND)
-                               so->so_temp = NULL;
-
-                       if (dontroute)
+                       if (dontroute) {
                                so->so_options &= ~SO_DONTROUTE;
+                       }
 
                        clen = 0;
-                       control = control_copy;
-                       control_copy = NULL;
+                       control = NULL;
                        top = NULL;
                        mp = &top;
-                       if (error)
-                               goto release;
+                       if (error) {
+                               goto out_locked;
+                       }
                } while (resid && space > 0);
        } while (resid);
 
-release:
-       if (sblocked)
-               sbunlock(&so->so_snd, FALSE);   /* will unlock socket */
-       else
+out_locked:
+       if (sblocked) {
+               sbunlock(&so->so_snd, FALSE);   /* will unlock socket */
+       } else {
                socket_unlock(so, 1);
-out:
-       if (top != NULL)
+       }
+       if (top != NULL) {
                m_freem(top);
-       if (control != NULL)
+       }
+       if (control != NULL) {
                m_freem(control);
-       if (freelist != NULL)
+       }
+       if (freelist != NULL) {
                m_freem_list(freelist);
-       if (control_copy != NULL)
-               m_freem(control_copy);
+       }
 
-       /*
-        * One write has been done. This was enough. Get back to "normal"
-        * behavior.
-        */
-       if (so->so_flags1 & SOF1_PRECONNECT_DATA)
-               so->so_flags1 &= ~SOF1_PRECONNECT_DATA;
+       soclearfastopen(so);
 
        if (en_tracing) {
                /* resid passed here is the bytes left in uio */
@@ -2388,7 +2565,53 @@ out:
        KERNEL_DEBUG(DBG_FNC_SOSEND | DBG_FUNC_END, so, resid,
            so->so_snd.sb_cc, space, error);
 
-       return (error);
+       return error;
+}
+
+int
+sosend_reinject(struct socket *so, struct sockaddr *addr, struct mbuf *top, struct mbuf *control, uint32_t sendflags)
+{
+       struct mbuf *m0 = NULL, *control_end = NULL;
+
+       socket_lock_assert_owned(so);
+
+       /*
+        * top must points to mbuf chain to be sent.
+        * If control is not NULL, top must be packet header
+        */
+       VERIFY(top != NULL &&
+           (control == NULL || top->m_flags & M_PKTHDR));
+
+       /*
+        * If control is not passed in, see if we can get it
+        * from top.
+        */
+       if (control == NULL && (top->m_flags & M_PKTHDR) == 0) {
+               // Locate start of control if present and start of data
+               for (m0 = top; m0 != NULL; m0 = m0->m_next) {
+                       if (m0->m_flags & M_PKTHDR) {
+                               top = m0;
+                               break;
+                       } else if (m0->m_type == MT_CONTROL) {
+                               if (control == NULL) {
+                                       // Found start of control
+                                       control = m0;
+                               }
+                               if (control != NULL && m0->m_next != NULL && m0->m_next->m_type != MT_CONTROL) {
+                                       // Found end of control
+                                       control_end = m0;
+                               }
+                       }
+               }
+               if (control_end != NULL) {
+                       control_end->m_next = NULL;
+               }
+       }
+
+       int error = (*so->so_proto->pr_usrreqs->pru_send)
+           (so, sendflags, top, addr, control, current_proc());
+
+       return error;
 }
 
 /*
@@ -2459,10 +2682,10 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
            (so->so_proto->pr_flags & PR_ATOMIC);
        OSIncrementAtomicLong(&p->p_stats->p_ru.ru_msgsnd);
 
-       error = sosendcheck(so, NULL, resid, 0, atomic, flags,
-           &sblocked, NULL);
-       if (error)
+       error = sosendcheck(so, NULL, resid, 0, atomic, flags, &sblocked);
+       if (error) {
                goto release;
+       }
 
        /*
         * Use big 4 KB clusters when the outgoing interface does not prefer
@@ -2470,8 +2693,9 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
         */
        bigcl = !(so->so_flags1 & SOF1_IF_2KCL) || sosendbigcl_ignore_capab;
 
-       if (soreserveheadroom != 0)
+       if (soreserveheadroom != 0) {
                headroom = so->so_pktheadroom;
+       }
 
        do {
                int i;
@@ -2480,10 +2704,11 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                size_t maxpktlen = 0;
                int bytes_to_alloc;
 
-               if (sosendminchain > 0)
+               if (sosendminchain > 0) {
                        chainlength = 0;
-               else
+               } else {
                        chainlength = sosendmaxchain;
+               }
 
                socket_unlock(so, 0);
 
@@ -2497,18 +2722,21 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                        len = uio_resid(auio);
 
                        /* Do nothing for empty messages */
-                       if (len == 0)
+                       if (len == 0) {
                                continue;
+                       }
 
                        num_needed += 1;
                        uiolast += 1;
 
-                       if (len > maxpktlen)
+                       if (len > maxpktlen) {
                                maxpktlen = len;
+                       }
 
                        chainlength += len;
-                       if (chainlength > sosendmaxchain)
+                       if (chainlength > sosendmaxchain) {
                                break;
+                       }
                }
                /*
                 * Nothing left to send
@@ -2531,19 +2759,19 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                if (bytes_to_alloc > MCLBYTES &&
                    bytes_to_alloc <= MBIGCLBYTES && bigcl) {
                        freelist = m_getpackets_internal(
-                           (unsigned int *)&num_needed,
-                           num_needed, M_WAIT, 1,
-                           MBIGCLBYTES);
+                               (unsigned int *)&num_needed,
+                               num_needed, M_WAIT, 1,
+                               MBIGCLBYTES);
                } else if (bytes_to_alloc > _MHLEN &&
                    bytes_to_alloc <= MCLBYTES) {
                        freelist = m_getpackets_internal(
-                           (unsigned int *)&num_needed,
-                           num_needed, M_WAIT, 1,
-                           MCLBYTES);
+                               (unsigned int *)&num_needed,
+                               num_needed, M_WAIT, 1,
+                               MCLBYTES);
                } else {
                        freelist = m_allocpacket_internal(
-                           (unsigned int *)&num_needed,
-                           bytes_to_alloc, NULL, M_WAIT, 1, 0);
+                               (unsigned int *)&num_needed,
+                               bytes_to_alloc, NULL, M_WAIT, 1, 0);
                }
 
                if (freelist == NULL) {
@@ -2564,8 +2792,9 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                        bytes_to_copy = uio_resid(auio);
 
                        /* Do nothing for empty messages */
-                       if (bytes_to_copy == 0)
+                       if (bytes_to_copy == 0) {
                                continue;
+                       }
                        /*
                         * Leave headroom for protocol headers
                         * in the first mbuf of the chain
@@ -2573,14 +2802,15 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                        m->m_data += headroom;
 
                        for (n = m; n != NULL; n = n->m_next) {
-                               if ((m->m_flags & M_EXT))
+                               if ((m->m_flags & M_EXT)) {
                                        mlen = m->m_ext.ext_size -
-                                           m_leadingspace(m);
-                               else if ((m->m_flags & M_PKTHDR))
+                                           M_LEADINGSPACE(m);
+                               } else if ((m->m_flags & M_PKTHDR)) {
                                        mlen =
-                                           MHLEN - m_leadingspace(m);
-                               else
-                                       mlen = MLEN - m_leadingspace(m);
+                                           MHLEN - M_LEADINGSPACE(m);
+                               } else {
+                                       mlen = MLEN - M_LEADINGSPACE(m);
+                               }
                                len = imin(mlen, bytes_to_copy);
 
                                /*
@@ -2589,8 +2819,9 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                                 */
                                error = uiomove(mtod(n, caddr_t),
                                    len, auio);
-                               if (error != 0)
+                               if (error != 0) {
                                        break;
+                               }
                                n->m_len = len;
                                m->m_pkthdr.len += len;
 
@@ -2601,26 +2832,29 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                        }
                        if (m->m_pkthdr.len == 0) {
                                printf(
-                                   "%s:%d so %llx pkt %llx type %u len null\n",
-                                   __func__, __LINE__,
-                                   (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
-                                   (uint64_t)DEBUG_KERNEL_ADDRPERM(m),
-                                   m->m_type);
+                                       "%s:%d so %llx pkt %llx type %u len null\n",
+                                       __func__, __LINE__,
+                                       (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
+                                       (uint64_t)DEBUG_KERNEL_ADDRPERM(m),
+                                       m->m_type);
                        }
-                       if (error != 0)
+                       if (error != 0) {
                                break;
+                       }
                        m = m->m_nextpkt;
                }
 
                socket_lock(so, 0);
 
-               if (error)
+               if (error) {
                        goto release;
+               }
                top = freelist;
                freelist = NULL;
 
-               if (dontroute)
+               if (dontroute) {
                        so->so_options |= SO_DONTROUTE;
+               }
 
                if ((flags & MSG_SKIPCFIL) == 0) {
                        struct mbuf **prevnextp = NULL;
@@ -2635,8 +2869,9 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                                 */
                                error = sflt_data_out(so, NULL, &m,
                                    NULL, 0);
-                               if (error != 0 && error != EJUSTRETURN)
+                               if (error != 0 && error != EJUSTRETURN) {
                                        goto release;
+                               }
 
 #if CONTENT_FILTER
                                if (error == 0) {
@@ -2645,8 +2880,9 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                                         */
                                        error = cfil_sock_data_out(so, NULL, m,
                                            NULL, 0);
-                                       if (error != 0 && error != EJUSTRETURN)
+                                       if (error != 0 && error != EJUSTRETURN) {
                                                goto release;
+                                       }
                                }
 #endif /* CONTENT_FILTER */
                                /*
@@ -2655,42 +2891,49 @@ sosend_list(struct socket *so, struct uio **uioarray, u_int uiocnt, int flags)
                                 */
                                if (error == EJUSTRETURN) {
                                        error = 0;
-                                       if (prevnextp != NULL)
+                                       if (prevnextp != NULL) {
                                                *prevnextp = nextpkt;
-                                       else
+                                       } else {
                                                top = nextpkt;
+                                       }
                                }
 
                                m = nextpkt;
-                               if (m != NULL)
+                               if (m != NULL) {
                                        prevnextp = &m->m_nextpkt;
+                               }
                        }
                }
-               if (top != NULL)
+               if (top != NULL) {
                        error = (*so->so_proto->pr_usrreqs->pru_send_list)
                            (so, 0, top, NULL, NULL, p);
+               }
 
-               if (dontroute)
+               if (dontroute) {
                        so->so_options &= ~SO_DONTROUTE;
+               }
 
                top = NULL;
                uiofirst = uiolast;
        } while (resid > 0 && error == 0);
 release:
-       if (sblocked)
-               sbunlock(&so->so_snd, FALSE);   /* will unlock socket */
-       else
+       if (sblocked) {
+               sbunlock(&so->so_snd, FALSE);   /* will unlock socket */
+       } else {
                socket_unlock(so, 1);
+       }
 out:
-       if (top != NULL)
+       if (top != NULL) {
                m_freem(top);
-       if (freelist != NULL)
+       }
+       if (freelist != NULL) {
                m_freem_list(freelist);
+       }
 
        KERNEL_DEBUG(DBG_FNC_SOSEND_LIST | DBG_FUNC_END, so, resid,
            so->so_snd.sb_cc, 0, error);
 
-       return (error);
+       return error;
 }
 
 /*
@@ -2766,8 +3009,9 @@ soreceive_addr(struct proc *p, struct socket *so, struct sockaddr **psa,
                 * the record in front of any packets which may have
                 * been appended while we dropped the lock.
                 */
-               for (m = m0; m->m_next != NULL; m = m->m_next)
+               for (m = m0; m->m_next != NULL; m = m->m_next) {
                        sballoc(&so->so_rcv, m);
+               }
                sballoc(&so->so_rcv, m);
                if (so->so_rcv.sb_mb == NULL) {
                        so->so_rcv.sb_lastrecord = m0;
@@ -2809,7 +3053,7 @@ done:
        *mp = m;
        *nextrecordp = nextrecord;
 
-       return (error);
+       return error;
 }
 
 /*
@@ -2881,8 +3125,9 @@ soreceive_ctl(struct socket *so, struct mbuf **controlp, int flags,
                        sb_rcv->sb_mb = nextrecord;
                        SB_EMPTY_FIXUP(sb_rcv);
                }
-               if (nextrecord == NULL)
+               if (nextrecord == NULL) {
                        sb_rcv->sb_lastrecord = m;
+               }
        }
 
        SBLASTRECORDCHK(&so->so_rcv, "soreceive ctl");
@@ -2931,16 +3176,62 @@ soreceive_ctl(struct socket *so, struct mbuf **controlp, int flags,
         * records when the socket was unlocked above for
         * externalizing SCM_RIGHTS.
         */
-       if (m != NULL)
+       if (m != NULL) {
                nextrecord = sb_rcv->sb_mb->m_nextpkt;
-       else
+       } else {
                nextrecord = sb_rcv->sb_mb;
+       }
 
 done:
        *mp = m;
        *nextrecordp = nextrecord;
 
-       return (error);
+       return error;
+}
+
+/*
+ * If we have less data than requested, block awaiting more
+ * (subject to any timeout) if:
+ *   1. the current count is less than the low water mark, or
+ *   2. MSG_WAITALL is set, and it is possible to do the entire
+ *     receive operation at once if we block (resid <= hiwat).
+ *   3. MSG_DONTWAIT is not set
+ * If MSG_WAITALL is set but resid is larger than the receive buffer,
+ * we have to do the receive in sections, and thus risk returning
+ * a short count if a timeout or signal occurs after we start.
+ */
+static boolean_t
+so_should_wait(struct socket *so, struct uio *uio, struct mbuf *m, int flags)
+{
+       struct protosw *pr = so->so_proto;
+
+       /* No mbufs in the receive-queue? Wait! */
+       if (m == NULL) {
+               return true;
+       }
+
+       /* Not enough data in the receive socket-buffer - we may have to wait */
+       if ((flags & MSG_DONTWAIT) == 0 && so->so_rcv.sb_cc < uio_resid(uio) &&
+           m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0) {
+               /*
+                * Application did set the lowater-mark, so we should wait for
+                * this data to be present.
+                */
+               if (so->so_rcv.sb_cc < so->so_rcv.sb_lowat) {
+                       return true;
+               }
+
+               /*
+                * Application wants all the data - so let's try to do the
+                * receive-operation at once by waiting for everything to
+                * be there.
+                */
+               if ((flags & MSG_WAITALL) && uio_resid(uio) <= so->so_rcv.sb_hiwat) {
+                       return true;
+               }
+       }
+
+       return false;
 }
 
 /*
@@ -2993,7 +3284,6 @@ soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
        user_ssize_t orig_resid = uio_resid(uio);
        user_ssize_t delayed_copy_len;
        int can_delay;
-       int need_event;
        struct proc *p = current_proc();
        boolean_t en_tracing = FALSE;
 
@@ -3001,8 +3291,9 @@ soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
         * Sanity check on the length passed by caller as we are making 'int'
         * comparisons
         */
-       if (orig_resid < 0 || orig_resid > INT_MAX)
-               return (EINVAL);
+       if (orig_resid < 0 || orig_resid > INT_MAX) {
+               return EINVAL;
+       }
 
        KERNEL_DEBUG(DBG_FNC_SORECEIVE | DBG_FUNC_START, so,
            uio_resid(uio), so->so_rcv.sb_cc, so->so_rcv.sb_lowat,
@@ -3019,14 +3310,17 @@ soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
        }
 #endif
        mp = mp0;
-       if (psa != NULL)
+       if (psa != NULL) {
                *psa = NULL;
-       if (controlp != NULL)
+       }
+       if (controlp != NULL) {
                *controlp = NULL;
-       if (flagsp != NULL)
-               flags = *flagsp &~ MSG_EOR;
-       else
+       }
+       if (flagsp != NULL) {
+               flags = *flagsp & ~MSG_EOR;
+       } else {
                flags = 0;
+       }
 
        /*
         * If a recv attempt is made on a previously-accepted socket
@@ -3046,10 +3340,11 @@ soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
                 * prior to being returned from sodefunct(); there should
                 * be no data on its receive list, so panic otherwise.
                 */
-               if (so->so_state & SS_DEFUNCT)
+               if (so->so_state & SS_DEFUNCT) {
                        sb_empty_assert(sb, __func__);
+               }
                socket_unlock(so, 1);
-               return (error);
+               return error;
        }
 
        if ((so->so_flags1 & SOF1_PRECONNECT_DATA) &&
@@ -3064,7 +3359,7 @@ soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
 
                if (error) {
                        socket_unlock(so, 1);
-                       return (error);
+                       return error;
                }
        }
 
@@ -3100,11 +3395,12 @@ soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
                        socket_unlock(so, 1);
                        KERNEL_DEBUG(DBG_FNC_SORECEIVE | DBG_FUNC_END,
                            ENOBUFS, 0, 0, 0, 0);
-                       return (ENOBUFS);
+                       return ENOBUFS;
                }
                error = (*pr->pr_usrreqs->pru_rcvoob)(so, m, flags & MSG_PEEK);
-               if (error)
+               if (error) {
                        goto bad;
+               }
                socket_unlock(so, 0);
                do {
                        error = uiomove(mtod(m, caddr_t),
@@ -3113,8 +3409,9 @@ soreceive(struct socket *so, struct sockaddr **psa, struct uio *uio,
                } while (uio_resid(uio) && error == 0 && m != NULL);
                socket_lock(so, 0);
 bad:
-               if (m != NULL)
+               if (m != NULL) {
                        m_freem(m);
+               }
 
                if ((so->so_options & SO_WANTOOBFLAG) != 0) {
                        if (error == EWOULDBLOCK || error == EINVAL) {
@@ -3139,11 +3436,12 @@ bad:
                KERNEL_DEBUG(DBG_FNC_SORECEIVE | DBG_FUNC_END, error,
                    0, 0, 0, 0);
 
-               return (error);
+               return error;
        }
 nooob:
-       if (mp != NULL)
+       if (mp != NULL) {
                *mp = NULL;
+       }
 
        if (so->so_state & SS_ISCONFIRMING && uio_resid(uio)) {
                (*pr->pr_usrreqs->pru_rcvd)(so, 0);
@@ -3153,9 +3451,10 @@ nooob:
        delayed_copy_len = 0;
 restart:
 #ifdef MORE_LOCKING_DEBUG
-       if (so->so_usecount <= 1)
+       if (so->so_usecount <= 1) {
                printf("soreceive: sblock so=0x%llx ref=%d on socket\n",
                    (uint64_t)DEBUG_KERNEL_ADDRPERM(so), so->so_usecount);
+       }
 #endif
        /*
         * See if the socket has been closed (SS_NOFDREF|SS_CANTRCVMORE)
@@ -3176,7 +3475,7 @@ restart:
        if ((so->so_state & (SS_NOFDREF | SS_CANTRCVMORE)) ==
            (SS_NOFDREF | SS_CANTRCVMORE) && !(so->so_flags & SOF_MP_SUBFLOW)) {
                socket_unlock(so, 1);
-               return (0);
+               return 0;
        }
 
        error = sblock(&so->so_rcv, SBLOCKWAIT(flags));
@@ -3189,26 +3488,11 @@ restart:
                            VM_KERNEL_ADDRPERM(so), 0,
                            (int64_t)(orig_resid - uio_resid(uio)));
                }
-               return (error);
+               return error;
        }
 
        m = so->so_rcv.sb_mb;
-       /*
-        * If we have less data than requested, block awaiting more
-        * (subject to any timeout) if:
-        *   1. the current count is less than the low water mark, or
-        *   2. MSG_WAITALL is set, and it is possible to do the entire
-        *      receive operation at once if we block (resid <= hiwat).
-        *   3. MSG_DONTWAIT is not set
-        * If MSG_WAITALL is set but resid is larger than the receive buffer,
-        * we have to do the receive in sections, and thus risk returning
-        * a short count if a timeout or signal occurs after we start.
-        */
-       if (m == NULL || (((flags & MSG_DONTWAIT) == 0 &&
-           so->so_rcv.sb_cc < uio_resid(uio)) &&
-           (so->so_rcv.sb_cc < so->so_rcv.sb_lowat ||
-           ((flags & MSG_WAITALL) && uio_resid(uio) <= so->so_rcv.sb_hiwat)) &&
-           m->m_nextpkt == NULL && (pr->pr_flags & PR_ATOMIC) == 0)) {
+       if (so_should_wait(so, uio, m, flags)) {
                /*
                 * Panic if we notice inconsistencies in the socket's
                 * receive list; both sb_mb and sb_cc should correctly
@@ -3219,11 +3503,13 @@ restart:
                SB_MB_CHECK(&so->so_rcv);
 
                if (so->so_error) {
-                       if (m != NULL)
+                       if (m != NULL) {
                                goto dontblock;
+                       }
                        error = so->so_error;
-                       if ((flags & MSG_PEEK) == 0)
+                       if ((flags & MSG_PEEK) == 0) {
                                so->so_error = 0;
+                       }
                        goto release;
                }
                if (so->so_state & SS_CANTRCVMORE) {
@@ -3232,47 +3518,69 @@ restart:
                         * Deal with half closed connections
                         */
                        if ((so->so_state & SS_ISDISCONNECTED) == 0 &&
-                               cfil_sock_data_pending(&so->so_rcv) != 0)
+                           cfil_sock_data_pending(&so->so_rcv) != 0) {
                                CFIL_LOG(LOG_INFO,
-                                       "so %llx ignore SS_CANTRCVMORE",
-                                       (uint64_t)DEBUG_KERNEL_ADDRPERM(so));
-                       else
+                                   "so %llx ignore SS_CANTRCVMORE",
+                                   (uint64_t)DEBUG_KERNEL_ADDRPERM(so));
+                       else
 #endif /* CONTENT_FILTER */
-                       if (m != NULL)
+                       if (m != NULL) {
                                goto dontblock;
-                       else
+                       } else {
                                goto release;
+                       }
                }
-               for (; m != NULL; m = m->m_next)
+               for (; m != NULL; m = m->m_next) {
                        if (m->m_type == MT_OOBDATA || (m->m_flags & M_EOR)) {
                                m = so->so_rcv.sb_mb;
                                goto dontblock;
                        }
-               if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
+               }
+               if ((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING)) == 0 &&
                    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
                        error = ENOTCONN;
                        goto release;
                }
-               if (uio_resid(uio) == 0)
+               if (uio_resid(uio) == 0) {
                        goto release;
+               }
 
                if ((so->so_state & SS_NBIO) ||
-                   (flags & (MSG_DONTWAIT|MSG_NBIO))) {
+                   (flags & (MSG_DONTWAIT | MSG_NBIO))) {
                        error = EWOULDBLOCK;
                        goto release;
                }
                SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 1");
                SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 1");
-               sbunlock(&so->so_rcv, TRUE);    /* keep socket locked */
+               sbunlock(&so->so_rcv, TRUE);    /* keep socket locked */
 #if EVEN_MORE_LOCKING_DEBUG
-               if (socket_debug)
+               if (socket_debug) {
                        printf("Waiting for socket data\n");
+               }
 #endif
 
-               error = sbwait(&so->so_rcv);
+               /*
+                * Depending on the protocol (e.g. TCP), the following
+                * might cause the socket lock to be dropped and later
+                * be reacquired, and more data could have arrived and
+                * have been appended to the receive socket buffer by
+                * the time it returns.  Therefore, we only sleep in
+                * sbwait() below if and only if the wait-condition is still
+                * true.
+                */
+               if ((pr->pr_flags & PR_WANTRCVD) && so->so_pcb != NULL) {
+                       (*pr->pr_usrreqs->pru_rcvd)(so, flags);
+               }
+
+               error = 0;
+               if (so_should_wait(so, uio, so->so_rcv.sb_mb, flags)) {
+                       error = sbwait(&so->so_rcv);
+               }
+
 #if EVEN_MORE_LOCKING_DEBUG
-               if (socket_debug)
+               if (socket_debug) {
                        printf("SORECEIVE - sbwait returned %d\n", error);
+               }
 #endif
                if (so->so_usecount < 1) {
                        panic("%s: after 2nd sblock so=%p ref=%d on socket\n",
@@ -3288,7 +3596,7 @@ restart:
                                    VM_KERNEL_ADDRPERM(so), 0,
                                    (int64_t)(orig_resid - uio_resid(uio)));
                        }
-                       return (error);
+                       return error;
                }
                goto restart;
        }
@@ -3301,10 +3609,11 @@ dontblock:
        if ((pr->pr_flags & PR_ADDR) && m->m_type == MT_SONAME) {
                error = soreceive_addr(p, so, psa, flags, &m, &nextrecord,
                    mp0 == NULL);
-               if (error == ERESTART)
+               if (error == ERESTART) {
                        goto restart;
-               else if (error != 0)
+               } else if (error != 0) {
                        goto release;
+               }
                orig_resid = 0;
        }
 
@@ -3316,31 +3625,10 @@ dontblock:
         */
        if (m != NULL && m->m_type == MT_CONTROL) {
                error = soreceive_ctl(so, controlp, flags, &m, &nextrecord);
-               if (error != 0)
-                       goto release;
-               orig_resid = 0;
-       }
-
-       /*
-        * If the socket is a TCP socket with message delivery
-        * enabled, then create a control msg to deliver the
-        * relative TCP sequence number for this data. Waiting
-        * until this point will protect against failures to
-        * allocate an mbuf for control msgs.
-        */
-       if (so->so_type == SOCK_STREAM && SOCK_PROTO(so) == IPPROTO_TCP &&
-           (so->so_flags & SOF_ENABLE_MSGS) && controlp != NULL) {
-               struct mbuf *seq_cm;
-
-               seq_cm = sbcreatecontrol((caddr_t)&m->m_pkthdr.msg_seq,
-                   sizeof (uint32_t), SCM_SEQNUM, SOL_SOCKET);
-               if (seq_cm == NULL) {
-                       /* unable to allocate a control mbuf */
-                       error = ENOBUFS;
+               if (error != 0) {
                        goto release;
                }
-               *controlp = seq_cm;
-               controlp = &seq_cm->m_next;
+               orig_resid = 0;
        }
 
        if (m != NULL) {
@@ -3360,12 +3648,14 @@ dontblock:
                                    nextrecord);
                                /* NOTREACHED */
                        }
-                       if (nextrecord == NULL)
+                       if (nextrecord == NULL) {
                                so->so_rcv.sb_lastrecord = m;
+                       }
                }
                type = m->m_type;
-               if (type == MT_OOBDATA)
+               if (type == MT_OOBDATA) {
                        flags |= MSG_OOB;
+               }
        } else {
                if (!(flags & MSG_PEEK)) {
                        SB_EMPTY_FIXUP(&so->so_rcv);
@@ -3377,18 +3667,18 @@ dontblock:
        moff = 0;
        offset = 0;
 
-       if (!(flags & MSG_PEEK) && uio_resid(uio) > sorecvmincopy)
+       if (!(flags & MSG_PEEK) && uio_resid(uio) > sorecvmincopy) {
                can_delay = 1;
-       else
+       } else {
                can_delay = 0;
-
-       need_event = 0;
+       }
 
        while (m != NULL &&
            (uio_resid(uio) - delayed_copy_len) > 0 && error == 0) {
                if (m->m_type == MT_OOBDATA) {
-                       if (type != MT_OOBDATA)
+                       if (type != MT_OOBDATA) {
                                break;
+                       }
                } else if (type == MT_OOBDATA) {
                        break;
                }
@@ -3403,10 +3693,12 @@ dontblock:
                }
                so->so_state &= ~SS_RCVATMARK;
                len = uio_resid(uio) - delayed_copy_len;
-               if (so->so_oobmark && len > so->so_oobmark - offset)
+               if (so->so_oobmark && len > so->so_oobmark - offset) {
                        len = so->so_oobmark - offset;
-               if (len > m->m_len - moff)
+               }
+               if (len > m->m_len - moff) {
                        len = m->m_len - moff;
+               }
                /*
                 * If mp is set, just pass back the mbufs.
                 * Otherwise copy them out via the uio, then free.
@@ -3459,15 +3751,17 @@ dontblock:
                                    (int)len, uio);
                                socket_lock(so, 0);
 
-                               if (error)
+                               if (error) {
                                        goto release;
+                               }
                        }
                } else {
                        uio_setresid(uio, (uio_resid(uio) - len));
                }
                if (len == m->m_len - moff) {
-                       if (m->m_flags & M_EOR)
+                       if (m->m_flags & M_EOR) {
                                flags |= MSG_EOR;
+                       }
                        if (flags & MSG_PEEK) {
                                m = m->m_next;
                                moff = 0;
@@ -3476,46 +3770,26 @@ dontblock:
                                sbfree(&so->so_rcv, m);
                                m->m_nextpkt = NULL;
 
-                               /*
-                                * If this packet is an unordered packet
-                                * (indicated by M_UNORDERED_DATA flag), remove
-                                * the additional bytes added to the
-                                * receive socket buffer size.
-                                */
-                               if ((so->so_flags & SOF_ENABLE_MSGS) &&
-                                   m->m_len &&
-                                   (m->m_flags & M_UNORDERED_DATA) &&
-                                   sbreserve(&so->so_rcv,
-                                   so->so_rcv.sb_hiwat - m->m_len)) {
-                                       if (so->so_msg_state->msg_uno_bytes >
-                                           m->m_len) {
-                                               so->so_msg_state->
-                                                   msg_uno_bytes -= m->m_len;
-                                       } else {
-                                               so->so_msg_state->
-                                                   msg_uno_bytes = 0;
-                                       }
-                                       m->m_flags &= ~M_UNORDERED_DATA;
-                               }
-
                                if (mp != NULL) {
                                        *mp = m;
                                        mp = &m->m_next;
                                        so->so_rcv.sb_mb = m = m->m_next;
                                        *mp = NULL;
                                } else {
-                                       if (free_list == NULL)
+                                       if (free_list == NULL) {
                                                free_list = m;
-                                       else
+                                       } else {
                                                ml->m_next = m;
+                                       }
                                        ml = m;
                                        so->so_rcv.sb_mb = m = m->m_next;
                                        ml->m_next = NULL;
                                }
                                if (m != NULL) {
                                        m->m_nextpkt = nextrecord;
-                                       if (nextrecord == NULL)
+                                       if (nextrecord == NULL) {
                                                so->so_rcv.sb_lastrecord = m;
+                                       }
                                } else {
                                        so->so_rcv.sb_mb = nextrecord;
                                        SB_EMPTY_FIXUP(&so->so_rcv);
@@ -3530,10 +3804,11 @@ dontblock:
                                if (mp != NULL) {
                                        int copy_flag;
 
-                                       if (flags & MSG_DONTWAIT)
+                                       if (flags & MSG_DONTWAIT) {
                                                copy_flag = M_DONTWAIT;
-                                       else
+                                       } else {
                                                copy_flag = M_WAIT;
+                                       }
                                        *mp = m_copym(m, 0, len, copy_flag);
                                        /*
                                         * Failed to allocate an mbuf?
@@ -3557,22 +3832,18 @@ dontblock:
                                so->so_oobmark -= len;
                                if (so->so_oobmark == 0) {
                                        so->so_state |= SS_RCVATMARK;
-                                       /*
-                                        * delay posting the actual event until
-                                        * after any delayed copy processing
-                                        * has finished
-                                        */
-                                       need_event = 1;
                                        break;
                                }
                        } else {
                                offset += len;
-                               if (offset == so->so_oobmark)
+                               if (offset == so->so_oobmark) {
                                        break;
+                               }
                        }
                }
-               if (flags & MSG_EOR)
+               if (flags & MSG_EOR) {
                        break;
+               }
                /*
                 * If the MSG_WAITALL or MSG_WAITSTREAM flag is set
                 * (for non-atomic socket), we must not quit until
@@ -3581,15 +3852,16 @@ dontblock:
                 * count but without error.  Keep sockbuf locked
                 * against other readers.
                 */
-               while (flags & (MSG_WAITALL|MSG_WAITSTREAM) && m == NULL &&
+               while (flags & (MSG_WAITALL | MSG_WAITSTREAM) && m == NULL &&
                    (uio_resid(uio) - delayed_copy_len) > 0 &&
                    !sosendallatonce(so) && !nextrecord) {
                        if (so->so_error || ((so->so_state & SS_CANTRCVMORE)
 #if CONTENT_FILTER
                            && cfil_sock_data_pending(&so->so_rcv) == 0
 #endif /* CONTENT_FILTER */
-                           ))
+                           )) {
                                goto release;
+                       }
 
                        /*
                         * Depending on the protocol (e.g. TCP), the following
@@ -3600,10 +3872,9 @@ dontblock:
                         * sbwait() below if and only if the socket buffer is
                         * empty, in order to avoid a false sleep.
                         */
-                       if (pr->pr_flags & PR_WANTRCVD && so->so_pcb &&
-                           (((struct inpcb *)so->so_pcb)->inp_state !=
-                           INPCB_STATE_DEAD))
+                       if ((pr->pr_flags & PR_WANTRCVD) && so->so_pcb != NULL) {
                                (*pr->pr_usrreqs->pru_rcvd)(so, flags);
+                       }
 
                        SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 2");
                        SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 2");
@@ -3635,8 +3906,9 @@ dontblock:
                                error = sodelayed_copy(so, uio,
                                    &free_list, &delayed_copy_len);
 
-                               if (error)
+                               if (error) {
                                        goto release;
+                               }
                        }
                        m = so->so_rcv.sb_mb;
                        if (m != NULL) {
@@ -3658,8 +3930,9 @@ dontblock:
                        flags |= MSG_RCVMORE;
                } else {
                        flags |= MSG_TRUNC;
-                       if ((flags & MSG_PEEK) == 0)
+                       if ((flags & MSG_PEEK) == 0) {
                                (void) sbdroprecord(&so->so_rcv);
+                       }
                }
        }
 
@@ -3671,8 +3944,9 @@ dontblock:
         * is set), and so we set the flag now based on what we know
         * prior to calling pru_rcvd.
         */
-       if ((so->so_options & SO_WANTMORE) && so->so_rcv.sb_cc > 0)
+       if ((so->so_options & SO_WANTMORE) && so->so_rcv.sb_cc > 0) {
                flags |= MSG_HAVEMORE;
+       }
 
        if ((flags & MSG_PEEK) == 0) {
                if (m == NULL) {
@@ -3692,30 +3966,31 @@ dontblock:
                }
                SBLASTRECORDCHK(&so->so_rcv, "soreceive 4");
                SBLASTMBUFCHK(&so->so_rcv, "soreceive 4");
-               if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
+               if (pr->pr_flags & PR_WANTRCVD && so->so_pcb) {
                        (*pr->pr_usrreqs->pru_rcvd)(so, flags);
+               }
        }
 
        if (delayed_copy_len) {
                error = sodelayed_copy(so, uio, &free_list, &delayed_copy_len);
-               if (error)
+               if (error) {
                        goto release;
+               }
        }
        if (free_list != NULL) {
                m_freem_list(free_list);
                free_list = NULL;
        }
-       if (need_event)
-               postevent(so, 0, EV_OOB);
 
        if (orig_resid == uio_resid(uio) && orig_resid &&
            (flags & MSG_EOR) == 0 && (so->so_state & SS_CANTRCVMORE) == 0) {
-               sbunlock(&so->so_rcv, TRUE);    /* keep socket locked */
+               sbunlock(&so->so_rcv, TRUE);    /* keep socket locked */
                goto restart;
        }
 
-       if (flagsp != NULL)
+       if (flagsp != NULL) {
                *flagsp |= flags;
+       }
 release:
 #ifdef MORE_LOCKING_DEBUG
        if (so->so_usecount <= 1) {
@@ -3724,13 +3999,15 @@ release:
                /* NOTREACHED */
        }
 #endif
-       if (delayed_copy_len)
+       if (delayed_copy_len) {
                error = sodelayed_copy(so, uio, &free_list, &delayed_copy_len);
+       }
 
-       if (free_list != NULL)
+       if (free_list != NULL) {
                m_freem_list(free_list);
+       }
 
-       sbunlock(&so->so_rcv, FALSE);   /* will unlock socket */
+       sbunlock(&so->so_rcv, FALSE);   /* will unlock socket */
 
        if (en_tracing) {
                KERNEL_ENERGYTRACE(kEnTrActKernSockRead, DBG_FUNC_END,
@@ -3741,7 +4018,7 @@ release:
        KERNEL_DEBUG(DBG_FNC_SORECEIVE | DBG_FUNC_END, so, uio_resid(uio),
            so->so_rcv.sb_cc, 0, error);
 
-       return (error);
+       return error;
 }
 
 /*
@@ -3770,7 +4047,7 @@ sodelayed_copy(struct socket *so, struct uio *uio, struct mbuf **free_list,
 
        socket_lock(so, 0);
 
-       return (error);
+       return error;
 }
 
 static int
@@ -3788,8 +4065,9 @@ sodelayed_copy_list(struct socket *so, struct recv_msg_elem *msgarray,
                auio = msgarray[i].uio;
                for (m = ml; m != NULL; m = m->m_next) {
                        error = uiomove(mtod(m, caddr_t), m->m_len, auio);
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
+                       }
                }
        }
 out:
@@ -3798,7 +4076,7 @@ out:
        *free_list = NULL;
        *resid = 0;
 
-       return (error);
+       return error;
 }
 
 int
@@ -3834,10 +4112,11 @@ soreceive_list(struct socket *so, struct recv_msg_elem *msgarray, u_int uiocnt,
         * - Protocol must support packet chains
         * - The uio array is NULL (should we panic?)
         */
-       if (flagsp != NULL)
+       if (flagsp != NULL) {
                flags = *flagsp;
-       else
+       } else {
                flags = 0;
+       }
        if (flags & ~(MSG_PEEK | MSG_WAITALL | MSG_DONTWAIT | MSG_NEEDSA |
            MSG_NBIO)) {
                printf("%s invalid flags 0x%x\n", __func__, flags);
@@ -3876,10 +4155,11 @@ soreceive_list(struct socket *so, struct recv_msg_elem *msgarray, u_int uiocnt,
                goto out;
        }
 
-       if (!(flags & MSG_PEEK) && sorecvmincopy > 0)
+       if (!(flags & MSG_PEEK) && sorecvmincopy > 0) {
                can_delay = 1;
-       else
+       } else {
                can_delay = 0;
+       }
 
        socket_lock(so, 1);
        so_update_last_owner_locked(so, p);
@@ -3907,8 +4187,9 @@ soreceive_list(struct socket *so, struct recv_msg_elem *msgarray, u_int uiocnt,
                 * prior to being returned from sodefunct(); there should
                 * be no data on its receive list, so panic otherwise.
                 */
-               if (so->so_state & SS_DEFUNCT)
+               if (so->so_state & SS_DEFUNCT) {
                        sb_empty_assert(sb, __func__);
+               }
                goto release;
        }
 
@@ -3963,20 +4244,21 @@ restart:
 
                if (so->so_error) {
                        error = so->so_error;
-                       if ((flags & MSG_PEEK) == 0)
+                       if ((flags & MSG_PEEK) == 0) {
                                so->so_error = 0;
+                       }
                        goto release;
                }
                if (so->so_state & SS_CANTRCVMORE) {
                        goto release;
                }
-               if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) == 0 &&
+               if ((so->so_state & (SS_ISCONNECTED | SS_ISCONNECTING)) == 0 &&
                    (so->so_proto->pr_flags & PR_CONNREQUIRED)) {
                        error = ENOTCONN;
                        goto release;
                }
                if ((so->so_state & SS_NBIO) ||
-                   (flags & (MSG_DONTWAIT|MSG_NBIO))) {
+                   (flags & (MSG_DONTWAIT | MSG_NBIO))) {
                        error = EWOULDBLOCK;
                        goto release;
                }
@@ -3991,7 +4273,7 @@ restart:
                SBLASTRECORDCHK(&so->so_rcv, "soreceive sbwait 1");
                SBLASTMBUFCHK(&so->so_rcv, "soreceive sbwait 1");
 
-               sbunlock(&so->so_rcv, TRUE);    /* keep socket locked */
+               sbunlock(&so->so_rcv, TRUE);    /* keep socket locked */
                sblocked = 0;
 
                error = sbwait(&so->so_rcv);
@@ -4020,16 +4302,18 @@ restart:
 
        if ((pr->pr_flags & PR_ADDR) && m->m_type == MT_SONAME) {
                error = soreceive_addr(p, so, psa, flags, &m, &nextrecord, 1);
-               if (error == ERESTART)
+               if (error == ERESTART) {
                        goto restart;
-               else if (error != 0)
+               } else if (error != 0) {
                        goto release;
+               }
        }
 
        if (m != NULL && m->m_type == MT_CONTROL) {
                error = soreceive_ctl(so, controlp, flags, &m, &nextrecord);
-               if (error != 0)
+               if (error != 0) {
                        goto release;
+               }
        }
 
        if (m->m_pkthdr.len == 0) {
@@ -4047,15 +4331,18 @@ restart:
        ml = NULL;
        pktlen = 0;
        while (m != NULL && (len = resid - pktlen) >= 0 && error == 0) {
-               if (m->m_len == 0)
+               if (m->m_len == 0) {
                        panic("%p m_len zero", m);
-               if (m->m_type == 0)
+               }
+               if (m->m_type == 0) {
                        panic("%p m_type zero", m);
+               }
                /*
                 * Clip to the residual length
                 */
-               if (len > m->m_len)
+               if (len > m->m_len) {
                        len = m->m_len;
+               }
                pktlen += len;
                /*
                 * Copy the mbufs via the uio or delay the copy
@@ -4068,8 +4355,9 @@ restart:
                        socket_unlock(so, 0);
                        error = uiomove(mtod(m, caddr_t), (int)len, auio);
                        socket_lock(so, 0);
-                       if (error)
+                       if (error) {
                                goto release;
+                       }
                } else {
                        delayed_copy_len += len;
                }
@@ -4085,21 +4373,24 @@ restart:
                        /*
                         * Set the first packet to the head of the free list
                         */
-                       if (free_list == NULL)
+                       if (free_list == NULL) {
                                free_list = m;
+                       }
                        /*
                         * Link current packet to tail of free list
                         */
                        if (ml == NULL) {
-                               if (free_tail != NULL)
+                               if (free_tail != NULL) {
                                        free_tail->m_nextpkt = m;
+                               }
                                free_tail = m;
                        }
                        /*
                         * Link current mbuf to last mbuf of current packet
                         */
-                       if (ml != NULL)
+                       if (ml != NULL) {
                                ml->m_next = m;
+                       }
                        ml = m;
 
                        /*
@@ -4110,8 +4401,9 @@ restart:
 
                        if (m != NULL) {
                                m->m_nextpkt = nextrecord;
-                               if (nextrecord == NULL)
+                               if (nextrecord == NULL) {
                                        so->so_rcv.sb_lastrecord = m;
+                               }
                        } else {
                                so->so_rcv.sb_mb = nextrecord;
                                SB_EMPTY_FIXUP(&so->so_rcv);
@@ -4142,17 +4434,19 @@ restart:
                         * Copyout first the freelist then the partial mbuf
                         */
                        socket_unlock(so, 0);
-                       if (delayed_copy_len)
+                       if (delayed_copy_len) {
                                error = sodelayed_copy_list(so, msgarray,
                                    uiocnt, &free_list, &delayed_copy_len);
+                       }
 
                        if (error == 0) {
                                error = uiomove(mtod(m, caddr_t), (int)len,
                                    auio);
                        }
                        socket_lock(so, 0);
-                       if (error)
+                       if (error) {
                                goto release;
+                       }
 
                        m->m_data += len;
                        m->m_len -= len;
@@ -4194,13 +4488,14 @@ restart:
        if (npkts < uiocnt && error == 0 &&
            (flags & (MSG_RCVMORE | MSG_TRUNC)) == 0 &&
            (so->so_state & SS_CANTRCVMORE) == 0) {
-               sbunlock(&so->so_rcv, TRUE);    /* keep socket locked */
+               sbunlock(&so->so_rcv, TRUE);    /* keep socket locked */
                sblocked = 0;
 
                goto next;
        }
-       if (flagsp != NULL)
+       if (flagsp != NULL) {
                *flagsp |= flags;
+       }
 
 release:
        /*
@@ -4209,32 +4504,65 @@ release:
         * That way the caller won't be surprised if it receives less data
         * than requested.
         */
-       if ((so->so_options & SO_WANTMORE) && so->so_rcv.sb_cc > 0)
+       if ((so->so_options & SO_WANTMORE) && so->so_rcv.sb_cc > 0) {
                flags |= MSG_HAVEMORE;
+       }
 
-       if (pr->pr_flags & PR_WANTRCVD && so->so_pcb)
+       if (pr->pr_flags & PR_WANTRCVD && so->so_pcb) {
                (*pr->pr_usrreqs->pru_rcvd)(so, flags);
+       }
 
-       if (sblocked)
-               sbunlock(&so->so_rcv, FALSE);   /* will unlock socket */
-       else
+       if (sblocked) {
+               sbunlock(&so->so_rcv, FALSE);   /* will unlock socket */
+       } else {
                socket_unlock(so, 1);
+       }
 
-       if (delayed_copy_len)
+       if (delayed_copy_len) {
                error = sodelayed_copy_list(so, msgarray, uiocnt,
                    &free_list, &delayed_copy_len);
+       }
 out:
        /*
         * Amortize the cost of freeing the mbufs
         */
-       if (free_list != NULL)
+       if (free_list != NULL) {
                m_freem_list(free_list);
-       if (free_others != NULL)
+       }
+       if (free_others != NULL) {
                m_freem_list(free_others);
+       }
 
        KERNEL_DEBUG(DBG_FNC_SORECEIVE_LIST | DBG_FUNC_END, error,
            0, 0, 0, 0);
-       return (error);
+       return error;
+}
+
+static int
+so_statistics_event_to_nstat_event(int64_t *input_options,
+    uint64_t *nstat_event)
+{
+       int error = 0;
+       switch (*input_options) {
+       case SO_STATISTICS_EVENT_ENTER_CELLFALLBACK:
+               *nstat_event = NSTAT_EVENT_SRC_ENTER_CELLFALLBACK;
+               break;
+       case SO_STATISTICS_EVENT_EXIT_CELLFALLBACK:
+               *nstat_event = NSTAT_EVENT_SRC_EXIT_CELLFALLBACK;
+               break;
+#if (DEBUG || DEVELOPMENT)
+       case SO_STATISTICS_EVENT_RESERVED_1:
+               *nstat_event = NSTAT_EVENT_SRC_RESERVED_1;
+               break;
+       case SO_STATISTICS_EVENT_RESERVED_2:
+               *nstat_event = NSTAT_EVENT_SRC_RESERVED_2;
+               break;
+#endif /* (DEBUG || DEVELOPMENT) */
+       default:
+               error = EINVAL;
+               break;
+       }
+       return error;
 }
 
 /*
@@ -4268,7 +4596,7 @@ soshutdown(struct socket *so, int how)
        case SHUT_RDWR:
                socket_lock(so, 1);
                if ((so->so_state &
-                   (SS_ISCONNECTED|SS_ISCONNECTING|SS_ISDISCONNECTING)) == 0) {
+                   (SS_ISCONNECTED | SS_ISCONNECTING | SS_ISDISCONNECTING)) == 0) {
                        error = ENOTCONN;
                } else {
                        error = soshutdownlock(so, how);
@@ -4282,7 +4610,7 @@ soshutdown(struct socket *so, int how)
 
        KERNEL_DEBUG(DBG_FNC_SOSHUTDOWN | DBG_FUNC_END, how, error, 0, 0, 0);
 
-       return (error);
+       return error;
 }
 
 int
@@ -4300,7 +4628,6 @@ soshutdownlock_final(struct socket *so, int how)
                        goto done;
                }
                sorflush(so);
-               postevent(so, 0, EV_RCLOSED);
        }
        if (how != SHUT_RD) {
                if ((so->so_state & SS_CANTSENDMORE) != 0) {
@@ -4309,11 +4636,10 @@ soshutdownlock_final(struct socket *so, int how)
                        goto done;
                }
                error = (*pr->pr_usrreqs->pru_shutdown)(so);
-               postevent(so, 0, EV_WCLOSED);
        }
 done:
        KERNEL_DEBUG(DBG_FNC_SOSHUTDOWN, how, 1, 0, 0, 0);
-       return (error);
+       return error;
 }
 
 int
@@ -4340,7 +4666,7 @@ soshutdownlock(struct socket *so, int how)
        error = soshutdownlock_final(so, how);
 
 done:
-       return (error);
+       return error;
 }
 
 void
@@ -4358,12 +4684,12 @@ sowflush(struct socket *so)
        (void) sblock(sb, SBL_WAIT | SBL_NOINTR | SBL_IGNDEFUNCT);
        VERIFY(sb->sb_flags & SB_LOCK);
 
-       sb->sb_flags            &= ~(SB_SEL|SB_UPCALL);
-       sb->sb_flags            |= SB_DROP;
-       sb->sb_upcall           = NULL;
-       sb->sb_upcallarg        = NULL;
+       sb->sb_flags            &= ~(SB_SEL | SB_UPCALL);
+       sb->sb_flags            |= SB_DROP;
+       sb->sb_upcall           = NULL;
+       sb->sb_upcallarg        = NULL;
 
-       sbunlock(sb, TRUE);     /* keep socket locked */
+       sbunlock(sb, TRUE);     /* keep socket locked */
 
        selthreadclear(&sb->sb_sel);
        sbrelease(sb);
@@ -4382,12 +4708,13 @@ sorflush(struct socket *so)
         * as part of sofreelastref(), and at that time, pr_getlock() may no
         * longer be able to return us the lock; this will be fixed in future.
         */
-       if (so->so_proto->pr_getlock != NULL)
+       if (so->so_proto->pr_getlock != NULL) {
                mutex_held = (*so->so_proto->pr_getlock)(so, 0);
-       else
+       } else {
                mutex_held = so->so_proto->pr_domain->dom_mtx;
+       }
 
-       lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
+       LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
 #endif /* notyet */
 
        sflt_notify(so, sock_evt_flush_read, NULL);
@@ -4412,20 +4739,20 @@ sorflush(struct socket *so)
         * Make sure to not carry over SB_LOCK in "asb", as we need
         * to acquire it later as part of sbrelease().
         */
-       bzero(&asb, sizeof (asb));
-       asb.sb_cc               = sb->sb_cc;
-       asb.sb_hiwat            = sb->sb_hiwat;
-       asb.sb_mbcnt            = sb->sb_mbcnt;
-       asb.sb_mbmax            = sb->sb_mbmax;
-       asb.sb_ctl              = sb->sb_ctl;
-       asb.sb_lowat            = sb->sb_lowat;
-       asb.sb_mb               = sb->sb_mb;
-       asb.sb_mbtail           = sb->sb_mbtail;
-       asb.sb_lastrecord       = sb->sb_lastrecord;
-       asb.sb_so               = sb->sb_so;
-       asb.sb_flags            = sb->sb_flags;
-       asb.sb_flags            &= ~(SB_LOCK|SB_SEL|SB_KNOTE|SB_UPCALL);
-       asb.sb_flags            |= SB_DROP;
+       bzero(&asb, sizeof(asb));
+       asb.sb_cc               = sb->sb_cc;
+       asb.sb_hiwat            = sb->sb_hiwat;
+       asb.sb_mbcnt            = sb->sb_mbcnt;
+       asb.sb_mbmax            = sb->sb_mbmax;
+       asb.sb_ctl              = sb->sb_ctl;
+       asb.sb_lowat            = sb->sb_lowat;
+       asb.sb_mb               = sb->sb_mb;
+       asb.sb_mbtail           = sb->sb_mbtail;
+       asb.sb_lastrecord       = sb->sb_lastrecord;
+       asb.sb_so               = sb->sb_so;
+       asb.sb_flags            = sb->sb_flags;
+       asb.sb_flags            &= ~(SB_LOCK | SB_SEL | SB_KNOTE | SB_UPCALL);
+       asb.sb_flags            |= SB_DROP;
 
        /*
         * Ideally we'd bzero() these and preserve the ones we need;
@@ -4436,23 +4763,23 @@ sorflush(struct socket *so)
         * Setting SB_DROP acts as a barrier to prevent further appends.
         * Clearing SB_SEL is done for selthreadclear() below.
         */
-       sb->sb_cc               = 0;
-       sb->sb_hiwat            = 0;
-       sb->sb_mbcnt            = 0;
-       sb->sb_mbmax            = 0;
-       sb->sb_ctl              = 0;
-       sb->sb_lowat            = 0;
-       sb->sb_mb               = NULL;
-       sb->sb_mbtail           = NULL;
-       sb->sb_lastrecord       = NULL;
-       sb->sb_timeo.tv_sec     = 0;
-       sb->sb_timeo.tv_usec    = 0;
-       sb->sb_upcall           = NULL;
-       sb->sb_upcallarg        = NULL;
-       sb->sb_flags            &= ~(SB_SEL|SB_UPCALL);
-       sb->sb_flags            |= SB_DROP;
-
-       sbunlock(sb, TRUE);     /* keep socket locked */
+       sb->sb_cc               = 0;
+       sb->sb_hiwat            = 0;
+       sb->sb_mbcnt            = 0;
+       sb->sb_mbmax            = 0;
+       sb->sb_ctl              = 0;
+       sb->sb_lowat            = 0;
+       sb->sb_mb               = NULL;
+       sb->sb_mbtail           = NULL;
+       sb->sb_lastrecord       = NULL;
+       sb->sb_timeo.tv_sec     = 0;
+       sb->sb_timeo.tv_usec    = 0;
+       sb->sb_upcall           = NULL;
+       sb->sb_upcallarg        = NULL;
+       sb->sb_flags            &= ~(SB_SEL | SB_UPCALL);
+       sb->sb_flags            |= SB_DROP;
+
+       sbunlock(sb, TRUE);     /* keep socket locked */
 
        /*
         * Note that selthreadclear() is called on the original "sb" and
@@ -4462,8 +4789,9 @@ sorflush(struct socket *so)
         */
        selthreadclear(&sb->sb_sel);
 
-       if ((pr->pr_flags & PR_RIGHTS) && pr->pr_domain->dom_dispose)
+       if ((pr->pr_flags & PR_RIGHTS) && pr->pr_domain->dom_dispose) {
                (*pr->pr_domain->dom_dispose)(asb.sb_mb);
+       }
 
        sbrelease(&asb);
 }
@@ -4482,7 +4810,7 @@ sorflush(struct socket *so)
 int
 sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
 {
-       size_t  valsize;
+       size_t  valsize;
 
        /*
         * If the user gives us more than we wanted, we ignore it,
@@ -4490,16 +4818,19 @@ sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
         * wants, we return EINVAL.  On success, sopt->sopt_valsize
         * is set to however much we actually retrieved.
         */
-       if ((valsize = sopt->sopt_valsize) < minlen)
-               return (EINVAL);
-       if (valsize > len)
+       if ((valsize = sopt->sopt_valsize) < minlen) {
+               return EINVAL;
+       }
+       if (valsize > len) {
                sopt->sopt_valsize = valsize = len;
+       }
 
-       if (sopt->sopt_p != kernproc)
-               return (copyin(sopt->sopt_val, buf, valsize));
+       if (sopt->sopt_p != kernproc) {
+               return copyin(sopt->sopt_val, buf, valsize);
+       }
 
        bcopy(CAST_DOWN(caddr_t, sopt->sopt_val), buf, valsize);
-       return (0);
+       return 0;
 }
 
 /*
@@ -4512,44 +4843,48 @@ sooptcopyin(struct sockopt *sopt, void *buf, size_t len, size_t minlen)
 static int
 sooptcopyin_timeval(struct sockopt *sopt, struct timeval *tv_p)
 {
-       int                     error;
+       int                     error;
 
        if (proc_is64bit(sopt->sopt_p)) {
-               struct user64_timeval   tv64;
+               struct user64_timeval   tv64;
 
-               if (sopt->sopt_valsize < sizeof (tv64))
-                       return (EINVAL);
+               if (sopt->sopt_valsize < sizeof(tv64)) {
+                       return EINVAL;
+               }
 
-               sopt->sopt_valsize = sizeof (tv64);
+               sopt->sopt_valsize = sizeof(tv64);
                if (sopt->sopt_p != kernproc) {
-                       error = copyin(sopt->sopt_val, &tv64, sizeof (tv64));
-                       if (error != 0)
-                               return (error);
+                       error = copyin(sopt->sopt_val, &tv64, sizeof(tv64));
+                       if (error != 0) {
+                               return error;
+                       }
                } else {
                        bcopy(CAST_DOWN(caddr_t, sopt->sopt_val), &tv64,
-                           sizeof (tv64));
+                           sizeof(tv64));
                }
                if (tv64.tv_sec < 0 || tv64.tv_sec > LONG_MAX ||
-                   tv64.tv_usec < 0 || tv64.tv_usec >= 1000000)
-                       return (EDOM);
+                   tv64.tv_usec < 0 || tv64.tv_usec >= 1000000) {
+                       return EDOM;
+               }
 
                tv_p->tv_sec = tv64.tv_sec;
                tv_p->tv_usec = tv64.tv_usec;
        } else {
-               struct user32_timeval   tv32;
+               struct user32_timeval   tv32;
 
-               if (sopt->sopt_valsize < sizeof (tv32))
-                       return (EINVAL);
+               if (sopt->sopt_valsize < sizeof(tv32)) {
+                       return EINVAL;
+               }
 
-               sopt->sopt_valsize = sizeof (tv32);
+               sopt->sopt_valsize = sizeof(tv32);
                if (sopt->sopt_p != kernproc) {
-                       error = copyin(sopt->sopt_val, &tv32, sizeof (tv32));
+                       error = copyin(sopt->sopt_val, &tv32, sizeof(tv32));
                        if (error != 0) {
-                               return (error);
+                               return error;
                        }
                } else {
                        bcopy(CAST_DOWN(caddr_t, sopt->sopt_val), &tv32,
-                           sizeof (tv32));
+                           sizeof(tv32));
                }
 #ifndef __LP64__
                /*
@@ -4557,34 +4892,46 @@ sooptcopyin_timeval(struct sockopt *sopt, struct timeval *tv_p)
                 * limited range of data type"
                 */
                if (tv32.tv_sec < 0 || tv32.tv_sec > LONG_MAX ||
-                   tv32.tv_usec < 0 || tv32.tv_usec >= 1000000)
-                       return (EDOM);
+                   tv32.tv_usec < 0 || tv32.tv_usec >= 1000000) {
+                       return EDOM;
+               }
 #endif
                tv_p->tv_sec = tv32.tv_sec;
                tv_p->tv_usec = tv32.tv_usec;
        }
-       return (0);
+       return 0;
 }
 
-static int
-soopt_cred_check(struct socket *so, int priv)
+int
+soopt_cred_check(struct socket *so, int priv, boolean_t allow_root,
+    boolean_t ignore_delegate)
 {
        kauth_cred_t cred =  NULL;
        proc_t ep = PROC_NULL;
-       int error;
+       uid_t uid;
+       int error = 0;
 
-       if (so->so_flags & SOF_DELEGATED) {
+       if (ignore_delegate == false && so->so_flags & SOF_DELEGATED) {
                ep = proc_find(so->e_pid);
-               if (ep)
+               if (ep) {
                        cred = kauth_cred_proc_ref(ep);
+               }
        }
-       error = priv_check_cred(cred ? cred : so->so_cred, priv, 0);
-       if (cred)
+
+       uid = kauth_cred_getuid(cred ? cred : so->so_cred);
+
+       /* uid is 0 for root */
+       if (uid != 0 || !allow_root) {
+               error = priv_check_cred(cred ? cred : so->so_cred, priv, 0);
+       }
+       if (cred) {
                kauth_cred_unref(&cred);
-       if (ep != PROC_NULL)
+       }
+       if (ep != PROC_NULL) {
                proc_rele(ep);
+       }
 
-       return (error);
+       return error;
 }
 
 /*
@@ -4610,18 +4957,18 @@ soopt_cred_check(struct socket *so, int priv)
 int
 sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
 {
-       int     error, optval;
-       struct  linger l;
-       struct  timeval tv;
-#if CONFIG_MACF_SOCKET
-       struct mac extmac;
-#endif /* MAC_SOCKET */
-
-       if (sopt->sopt_dir != SOPT_SET)
+       int     error, optval;
+       int64_t long_optval;
+       struct  linger l;
+       struct  timeval tv;
+
+       if (sopt->sopt_dir != SOPT_SET) {
                sopt->sopt_dir = SOPT_SET;
+       }
 
-       if (dolock)
+       if (dolock) {
                socket_lock(so, 1);
+       }
 
        if ((so->so_state & (SS_CANTRCVMORE | SS_CANTSENDMORE)) ==
            (SS_CANTRCVMORE | SS_CANTSENDMORE) &&
@@ -4633,8 +4980,9 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
 
        error = sflt_setsockopt(so, sopt);
        if (error != 0) {
-               if (error == EJUSTRETURN)
+               if (error == EJUSTRETURN) {
                        error = 0;
+               }
                goto out;
        }
 
@@ -4654,23 +5002,26 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                 * return value indicates that the option is unsupported.
                 */
                if (so->so_proto != NULL && (error = so->so_proto->pr_usrreqs->
-                   pru_socheckopt(so, sopt)) != 0)
+                   pru_socheckopt(so, sopt)) != 0) {
                        goto out;
+               }
 
                error = 0;
                switch (sopt->sopt_name) {
                case SO_LINGER:
                case SO_LINGER_SEC:
-                       error = sooptcopyin(sopt, &l, sizeof (l), sizeof (l));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &l, sizeof(l), sizeof(l));
+                       if (error != 0) {
                                goto out;
+                       }
 
                        so->so_linger = (sopt->sopt_name == SO_LINGER) ?
                            l.l_linger : l.l_linger * hz;
-                       if (l.l_onoff != 0)
+                       if (l.l_onoff != 0) {
                                so->so_options |= SO_LINGER;
-                       else
+                       } else {
                                so->so_options &= ~SO_LINGER;
+                       }
                        break;
 
                case SO_DEBUG:
@@ -4683,29 +5034,33 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                case SO_OOBINLINE:
                case SO_TIMESTAMP:
                case SO_TIMESTAMP_MONOTONIC:
+               case SO_TIMESTAMP_CONTINUOUS:
                case SO_DONTTRUNC:
                case SO_WANTMORE:
                case SO_WANTOOBFLAG:
                case SO_NOWAKEFROMSLEEP:
                case SO_NOAPNFALLBK:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
-                       if (optval)
+                       }
+                       if (optval) {
                                so->so_options |= sopt->sopt_name;
-                       else
+                       } else {
                                so->so_options &= ~sopt->sopt_name;
+                       }
                        break;
 
                case SO_SNDBUF:
                case SO_RCVBUF:
                case SO_SNDLOWAT:
                case SO_RCVLOWAT:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
+                       }
 
                        /*
                         * Values < 1 make no sense for any of these
@@ -4764,8 +5119,9 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                                    so->so_rcv.sb_hiwat : optval;
                                data_len = so->so_rcv.sb_cc
                                    - so->so_rcv.sb_ctl;
-                               if (data_len >= so->so_rcv.sb_lowat)
-                                   sorwakeup(so);
+                               if (data_len >= so->so_rcv.sb_lowat) {
+                                       sorwakeup(so);
+                               }
                                break;
                        }
                        }
@@ -4774,8 +5130,9 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                case SO_SNDTIMEO:
                case SO_RCVTIMEO:
                        error = sooptcopyin_timeval(sopt, &tv);
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
+                       }
 
                        switch (sopt->sopt_name) {
                        case SO_SNDTIMEO:
@@ -4790,46 +5147,53 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                case SO_NKE: {
                        struct so_nke nke;
 
-                       error = sooptcopyin(sopt, &nke, sizeof (nke),
-                           sizeof (nke));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &nke, sizeof(nke),
+                           sizeof(nke));
+                       if (error != 0) {
                                goto out;
+                       }
 
                        error = sflt_attach_internal(so, nke.nke_handle);
                        break;
                }
 
                case SO_NOSIGPIPE:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
-                       if (optval != 0)
+                       }
+                       if (optval != 0) {
                                so->so_flags |= SOF_NOSIGPIPE;
-                       else
+                       } else {
                                so->so_flags &= ~SOF_NOSIGPIPE;
+                       }
                        break;
 
                case SO_NOADDRERR:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
-                       if (optval != 0)
+                       }
+                       if (optval != 0) {
                                so->so_flags |= SOF_NOADDRAVAIL;
-                       else
+                       } else {
                                so->so_flags &= ~SOF_NOADDRAVAIL;
+                       }
                        break;
 
                case SO_REUSESHAREUID:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
-                       if (optval != 0)
+                       }
+                       if (optval != 0) {
                                so->so_flags |= SOF_REUSESHAREUID;
-                       else
+                       } else {
                                so->so_flags &= ~SOF_REUSESHAREUID;
+                       }
                        break;
 
                case SO_NOTIFYCONFLICT:
@@ -4837,21 +5201,24 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                                error = EPERM;
                                goto out;
                        }
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
-                       if (optval != 0)
+                       }
+                       if (optval != 0) {
                                so->so_flags |= SOF_NOTIFYCONFLICT;
-                       else
+                       } else {
                                so->so_flags &= ~SOF_NOTIFYCONFLICT;
+                       }
                        break;
 
                case SO_RESTRICTIONS:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
+                       }
 
                        error = so_set_restrictions(so, optval);
                        break;
@@ -4864,16 +5231,19 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                        }
                        error = sooptcopyin(sopt, &optval, sizeof(optval),
                            sizeof(optval));
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
+                       }
                        if (optval != 0) {
                                error = soopt_cred_check(so,
-                                   PRIV_NET_RESTRICTED_AWDL);
-                               if (error == 0)
+                                   PRIV_NET_RESTRICTED_AWDL, false, false);
+                               if (error == 0) {
                                        inp_set_awdl_unrestricted(
-                                           sotoinpcb(so));
-                       } else
+                                               sotoinpcb(so));
+                               }
+                       } else {
                                inp_clear_awdl_unrestricted(sotoinpcb(so));
+                       }
                        break;
                case SO_INTCOPROC_ALLOW:
                        if (SOCK_DOM(so) != PF_INET6) {
@@ -4882,60 +5252,60 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                        }
                        error = sooptcopyin(sopt, &optval, sizeof(optval),
                            sizeof(optval));
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
-                       if (optval != 0) {
+                       }
+                       if (optval != 0 &&
+                           inp_get_intcoproc_allowed(sotoinpcb(so)) == FALSE) {
                                error = soopt_cred_check(so,
-                                   PRIV_NET_RESTRICTED_INTCOPROC);
-                               if (error == 0)
+                                   PRIV_NET_RESTRICTED_INTCOPROC, false, false);
+                               if (error == 0) {
                                        inp_set_intcoproc_allowed(
-                                           sotoinpcb(so));
-                       } else
+                                               sotoinpcb(so));
+                               }
+                       } else if (optval == 0) {
                                inp_clear_intcoproc_allowed(sotoinpcb(so));
+                       }
                        break;
 
                case SO_LABEL:
-#if CONFIG_MACF_SOCKET
-                       if ((error = sooptcopyin(sopt, &extmac, sizeof (extmac),
-                           sizeof (extmac))) != 0)
-                               goto out;
-
-                       error = mac_setsockopt_label(proc_ucred(sopt->sopt_p),
-                           so, &extmac);
-#else
                        error = EOPNOTSUPP;
-#endif /* MAC_SOCKET */
                        break;
 
                case SO_UPCALLCLOSEWAIT:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
-                       if (optval != 0)
+                       }
+                       if (optval != 0) {
                                so->so_flags |= SOF_UPCALLCLOSEWAIT;
-                       else
+                       } else {
                                so->so_flags &= ~SOF_UPCALLCLOSEWAIT;
+                       }
                        break;
 
                case SO_RANDOMPORT:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
-                       if (optval != 0)
+                       }
+                       if (optval != 0) {
                                so->so_flags |= SOF_BINDRANDOMPORT;
-                       else
+                       } else {
                                so->so_flags &= ~SOF_BINDRANDOMPORT;
+                       }
                        break;
 
                case SO_NP_EXTENSIONS: {
                        struct so_np_extensions sonpx;
 
-                       error = sooptcopyin(sopt, &sonpx, sizeof (sonpx),
-                           sizeof (sonpx));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &sonpx, sizeof(sonpx),
+                           sizeof(sonpx));
+                       if (error != 0) {
                                goto out;
+                       }
                        if (sonpx.npx_mask & ~SONPX_MASK_VALID) {
                                error = EINVAL;
                                goto out;
@@ -4944,41 +5314,46 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                         * Only one bit defined for now
                         */
                        if ((sonpx.npx_mask & SONPX_SETOPTSHUT)) {
-                               if ((sonpx.npx_flags & SONPX_SETOPTSHUT))
+                               if ((sonpx.npx_flags & SONPX_SETOPTSHUT)) {
                                        so->so_flags |= SOF_NPX_SETOPTSHUT;
-                               else
+                               } else {
                                        so->so_flags &= ~SOF_NPX_SETOPTSHUT;
+                               }
                        }
                        break;
                }
 
                case SO_TRAFFIC_CLASS: {
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
+                       }
                        if (optval >= SO_TC_NET_SERVICE_OFFSET) {
                                int netsvc = optval - SO_TC_NET_SERVICE_OFFSET;
                                error = so_set_net_service_type(so, netsvc);
                                goto out;
                        }
                        error = so_set_traffic_class(so, optval);
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
+                       }
                        so->so_flags1 &= ~SOF1_TC_NET_SERV_TYPE;
                        so->so_netsvctype = _NET_SERVICE_TYPE_UNSPEC;
                        break;
                }
 
                case SO_RECV_TRAFFIC_CLASS: {
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
-                       if (optval == 0)
+                       }
+                       if (optval == 0) {
                                so->so_flags &= ~SOF_RECV_TRAFFIC_CLASS;
-                       else
+                       } else {
                                so->so_flags |= SOF_RECV_TRAFFIC_CLASS;
+                       }
                        break;
                }
 
@@ -4987,12 +5362,14 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                        struct so_tcdbg so_tcdbg;
 
                        error = sooptcopyin(sopt, &so_tcdbg,
-                           sizeof (struct so_tcdbg), sizeof (struct so_tcdbg));
-                       if (error != 0)
+                           sizeof(struct so_tcdbg), sizeof(struct so_tcdbg));
+                       if (error != 0) {
                                goto out;
+                       }
                        error = so_set_tcdbg(so, &so_tcdbg);
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
+                       }
                        break;
                }
 #endif /* (DEVELOPMENT || DEBUG) */
@@ -5000,24 +5377,38 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                case SO_PRIVILEGED_TRAFFIC_CLASS:
                        error = priv_check_cred(kauth_cred_get(),
                            PRIV_NET_PRIVILEGED_TRAFFIC_CLASS, 0);
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       }
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
                                goto out;
-                       if (optval == 0)
+                       }
+                       if (optval == 0) {
                                so->so_flags &= ~SOF_PRIVILEGED_TRAFFIC_CLASS;
-                       else
+                       } else {
                                so->so_flags |= SOF_PRIVILEGED_TRAFFIC_CLASS;
+                       }
+                       break;
+
+#if (DEVELOPMENT || DEBUG)
+               case SO_DEFUNCTIT:
+                       error = sosetdefunct(current_proc(), so, 0, FALSE);
+                       if (error == 0) {
+                               error = sodefunct(current_proc(), so, 0);
+                       }
+
                        break;
+#endif /* (DEVELOPMENT || DEBUG) */
 
                case SO_DEFUNCTOK:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
                        if (error != 0 || (so->so_flags & SOF_DEFUNCT)) {
-                               if (error == 0)
+                               if (error == 0) {
                                        error = EBADF;
+                               }
                                goto out;
                        }
                        /*
@@ -5030,10 +5421,11 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                                error = EPERM;
                                goto out;
                        }
-                       if (optval)
+                       if (optval) {
                                so->so_flags &= ~SOF_NODEFUNCT;
-                       else
+                       } else {
                                so->so_flags |= SOF_NODEFUNCT;
+                       }
 
                        if (SOCK_DOM(so) == PF_INET ||
                            SOCK_DOM(so) == PF_INET6) {
@@ -5051,12 +5443,12 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                                    "TCP" : "UDP", inet_ntop(SOCK_DOM(so),
                                    ((SOCK_DOM(so) == PF_INET) ?
                                    (void *)&inp->inp_laddr.s_addr :
-                                   (void *)&inp->in6p_laddr), s, sizeof (s)),
+                                   (void *)&inp->in6p_laddr), s, sizeof(s)),
                                    ntohs(inp->in6p_lport),
                                    inet_ntop(SOCK_DOM(so),
                                    (SOCK_DOM(so) == PF_INET) ?
                                    (void *)&inp->inp_faddr.s_addr :
-                                   (void *)&inp->in6p_faddr, d, sizeof (d)),
+                                   (void *)&inp->in6p_faddr, d, sizeof(d)),
                                    ntohs(inp->in6p_fport),
                                    (so->so_flags & SOF_NODEFUNCT) ?
                                    "not " : "");
@@ -5079,10 +5471,11 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                        break;
 
                case SO_OPPORTUNISTIC:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error == 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error == 0) {
                                error = so_set_opportunistic(so, optval);
+                       }
                        break;
 
                case SO_FLUSH:
@@ -5091,10 +5484,11 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                        break;
 
                case SO_RECV_ANYIF:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error == 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error == 0) {
                                error = so_set_recv_anyif(so, optval);
+                       }
                        break;
 
                case SO_TRAFFIC_MGT_BACKGROUND: {
@@ -5107,25 +5501,27 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                case SO_FLOW_DIVERT_TOKEN:
                        error = flow_divert_token_set(so, sopt);
                        break;
-#endif /* FLOW_DIVERT */
+#endif  /* FLOW_DIVERT */
 
 
                case SO_DELEGATED:
-                       if ((error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval))) != 0)
+                       if ((error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval))) != 0) {
                                break;
+                       }
 
-                       error = so_set_effective_pid(so, optval, sopt->sopt_p);
+                       error = so_set_effective_pid(so, optval, sopt->sopt_p, true);
                        break;
 
                case SO_DELEGATED_UUID: {
                        uuid_t euuid;
 
-                       if ((error = sooptcopyin(sopt, &euuid, sizeof (euuid),
-                           sizeof (euuid))) != 0)
+                       if ((error = sooptcopyin(sopt, &euuid, sizeof(euuid),
+                           sizeof(euuid))) != 0) {
                                break;
+                       }
 
-                       error = so_set_effective_uuid(so, euuid, sopt->sopt_p);
+                       error = so_set_effective_uuid(so, euuid, sopt->sopt_p, true);
                        break;
                }
 
@@ -5133,55 +5529,134 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                case SO_NECP_ATTRIBUTES:
                        error = necp_set_socket_attributes(so, sopt);
                        break;
-#endif /* NECP */
 
-#if MPTCP
-               case SO_MPTCP_FASTJOIN:
-                       if (!((so->so_flags & SOF_MP_SUBFLOW) ||
-                           ((SOCK_CHECK_DOM(so, PF_MULTIPATH)) &&
-                           (SOCK_CHECK_PROTO(so, IPPROTO_TCP))))) {
-                               error = ENOPROTOOPT;
+               case SO_NECP_CLIENTUUID: {
+                       if (SOCK_DOM(so) == PF_MULTIPATH) {
+                               /* Handled by MPTCP itself */
                                break;
                        }
 
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error != 0)
+                       if (SOCK_DOM(so) != PF_INET && SOCK_DOM(so) != PF_INET6) {
+                               error = EINVAL;
+                               goto out;
+                       }
+
+                       struct inpcb *inp = sotoinpcb(so);
+                       if (!uuid_is_null(inp->necp_client_uuid)) {
+                               // Clear out the old client UUID if present
+                               necp_inpcb_remove_cb(inp);
+                       }
+
+                       error = sooptcopyin(sopt, &inp->necp_client_uuid,
+                           sizeof(uuid_t), sizeof(uuid_t));
+                       if (error != 0) {
+                               goto out;
+                       }
+
+                       if (uuid_is_null(inp->necp_client_uuid)) {
+                               error = EINVAL;
+                               goto out;
+                       }
+
+                       pid_t current_pid = proc_pid(current_proc());
+                       error = necp_client_register_socket_flow(current_pid,
+                           inp->necp_client_uuid, inp);
+                       if (error != 0) {
+                               uuid_clear(inp->necp_client_uuid);
+                               goto out;
+                       }
+
+                       if (inp->inp_lport != 0) {
+                               // There is a bound local port, so this is not
+                               // a fresh socket. Assign to the client.
+                               necp_client_assign_from_socket(current_pid, inp->necp_client_uuid, inp);
+                       }
+
+                       break;
+               }
+               case SO_NECP_LISTENUUID: {
+                       if (SOCK_DOM(so) != PF_INET && SOCK_DOM(so) != PF_INET6) {
+                               error = EINVAL;
+                               goto out;
+                       }
+
+                       struct inpcb *inp = sotoinpcb(so);
+                       if (!uuid_is_null(inp->necp_client_uuid)) {
+                               error = EINVAL;
+                               goto out;
+                       }
+
+                       error = sooptcopyin(sopt, &inp->necp_client_uuid,
+                           sizeof(uuid_t), sizeof(uuid_t));
+                       if (error != 0) {
+                               goto out;
+                       }
+
+                       if (uuid_is_null(inp->necp_client_uuid)) {
+                               error = EINVAL;
                                goto out;
-                       if (optval == 0)
-                               so->so_flags &= ~SOF_MPTCP_FASTJOIN;
-                       else
-                               so->so_flags |= SOF_MPTCP_FASTJOIN;
+                       }
+
+                       error = necp_client_register_socket_listener(proc_pid(current_proc()),
+                           inp->necp_client_uuid, inp);
+                       if (error != 0) {
+                               uuid_clear(inp->necp_client_uuid);
+                               goto out;
+                       }
+
+                       // Mark that the port registration is held by NECP
+                       inp->inp_flags2 |= INP2_EXTERNAL_PORT;
+
                        break;
-#endif /* MPTCP */
+               }
+#endif /* NECP */
 
                case SO_EXTENDED_BK_IDLE:
-                       error = sooptcopyin(sopt, &optval, sizeof (optval),
-                           sizeof (optval));
-                       if (error == 0)
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error == 0) {
                                error = so_set_extended_bk_idle(so, optval);
+                       }
                        break;
 
                case SO_MARK_CELLFALLBACK:
                        error = sooptcopyin(sopt, &optval, sizeof(optval),
                            sizeof(optval));
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
+                       }
                        if (optval < 0) {
                                error = EINVAL;
                                goto out;
                        }
-                       if (optval == 0)
+                       if (optval == 0) {
                                so->so_flags1 &= ~SOF1_CELLFALLBACK;
-                       else
+                       } else {
                                so->so_flags1 |= SOF1_CELLFALLBACK;
+                       }
+                       break;
+
+               case SO_STATISTICS_EVENT:
+                       error = sooptcopyin(sopt, &long_optval,
+                           sizeof(long_optval), sizeof(long_optval));
+                       if (error != 0) {
+                               goto out;
+                       }
+                       u_int64_t nstat_event = 0;
+                       error = so_statistics_event_to_nstat_event(
+                               &long_optval, &nstat_event);
+                       if (error != 0) {
+                               goto out;
+                       }
+                       nstat_pcb_event(sotoinpcb(so), nstat_event);
                        break;
 
                case SO_NET_SERVICE_TYPE: {
                        error = sooptcopyin(sopt, &optval, sizeof(optval),
                            sizeof(optval));
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
+                       }
                        error = so_set_net_service_type(so, optval);
                        break;
                }
@@ -5189,18 +5664,52 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                case SO_QOSMARKING_POLICY_OVERRIDE:
                        error = priv_check_cred(kauth_cred_get(),
                            PRIV_NET_QOSMARKING_POLICY_OVERRIDE, 0);
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
+                       }
                        error = sooptcopyin(sopt, &optval, sizeof(optval),
                            sizeof(optval));
-                       if (error != 0)
+                       if (error != 0) {
                                goto out;
-                       if (optval == 0)
+                       }
+                       if (optval == 0) {
                                so->so_flags1 &= ~SOF1_QOSMARKING_POLICY_OVERRIDE;
-                       else
+                       } else {
                                so->so_flags1 |= SOF1_QOSMARKING_POLICY_OVERRIDE;
+                       }
                        break;
 
+               case SO_MPKL_SEND_INFO: {
+                       struct so_mpkl_send_info so_mpkl_send_info;
+
+                       error = sooptcopyin(sopt, &so_mpkl_send_info,
+                           sizeof(struct so_mpkl_send_info), sizeof(struct so_mpkl_send_info));
+                       if (error != 0) {
+                               goto out;
+                       }
+                       uuid_copy(so->so_mpkl_send_uuid, so_mpkl_send_info.mpkl_uuid);
+                       so->so_mpkl_send_proto = so_mpkl_send_info.mpkl_proto;
+
+                       if (uuid_is_null(so->so_mpkl_send_uuid) && so->so_mpkl_send_proto == 0) {
+                               so->so_flags1 &= ~SOF1_MPKL_SEND_INFO;
+                       } else {
+                               so->so_flags1 |= SOF1_MPKL_SEND_INFO;
+                       }
+                       break;
+               }
+               case SO_WANT_KEV_SOCKET_CLOSED: {
+                       error = sooptcopyin(sopt, &optval, sizeof(optval),
+                           sizeof(optval));
+                       if (error != 0) {
+                               goto out;
+                       }
+                       if (optval == 0) {
+                               so->so_flags1 &= ~SOF1_WANT_KEV_SOCK_CLOSED;
+                       } else {
+                               so->so_flags1 |= SOF1_WANT_KEV_SOCK_CLOSED;
+                       }
+                       break;
+               }
                default:
                        error = ENOPROTOOPT;
                        break;
@@ -5211,17 +5720,18 @@ sosetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                }
        }
 out:
-       if (dolock)
+       if (dolock) {
                socket_unlock(so, 1);
-       return (error);
+       }
+       return error;
 }
 
 /* Helper routines for getsockopt */
 int
 sooptcopyout(struct sockopt *sopt, void *buf, size_t len)
 {
-       int     error;
-       size_t  valsize;
+       int     error;
+       size_t  valsize;
 
        error = 0;
 
@@ -5237,32 +5747,33 @@ sooptcopyout(struct sockopt *sopt, void *buf, size_t len)
        valsize = min(len, sopt->sopt_valsize);
        sopt->sopt_valsize = valsize;
        if (sopt->sopt_val != USER_ADDR_NULL) {
-               if (sopt->sopt_p != kernproc)
+               if (sopt->sopt_p != kernproc) {
                        error = copyout(buf, sopt->sopt_val, valsize);
-               else
+               } else {
                        bcopy(buf, CAST_DOWN(caddr_t, sopt->sopt_val), valsize);
+               }
        }
-       return (error);
+       return error;
 }
 
 static int
 sooptcopyout_timeval(struct sockopt *sopt, const struct timeval *tv_p)
 {
-       int                     error;
-       size_t                  len;
-       struct user64_timeval   tv64;
-       struct user32_timeval   tv32;
-       const void *            val;
-       size_t                  valsize;
+       int                     error;
+       size_t                  len;
+       struct user64_timeval   tv64 = {};
+       struct user32_timeval   tv32 = {};
+       const void *            val;
+       size_t                  valsize;
 
        error = 0;
        if (proc_is64bit(sopt->sopt_p)) {
-               len = sizeof (tv64);
+               len = sizeof(tv64);
                tv64.tv_sec = tv_p->tv_sec;
                tv64.tv_usec = tv_p->tv_usec;
                val = &tv64;
        } else {
-               len = sizeof (tv32);
+               len = sizeof(tv32);
                tv32.tv_sec = tv_p->tv_sec;
                tv32.tv_usec = tv_p->tv_usec;
                val = &tv32;
@@ -5270,12 +5781,13 @@ sooptcopyout_timeval(struct sockopt *sopt, const struct timeval *tv_p)
        valsize = min(len, sopt->sopt_valsize);
        sopt->sopt_valsize = valsize;
        if (sopt->sopt_val != USER_ADDR_NULL) {
-               if (sopt->sopt_p != kernproc)
+               if (sopt->sopt_p != kernproc) {
                        error = copyout(val, sopt->sopt_val, valsize);
-               else
+               } else {
                        bcopy(val, CAST_DOWN(caddr_t, sopt->sopt_val), valsize);
+               }
        }
-       return (error);
+       return error;
 }
 
 /*
@@ -5288,23 +5800,23 @@ sooptcopyout_timeval(struct sockopt *sopt, const struct timeval *tv_p)
 int
 sogetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
 {
-       int     error, optval;
-       struct  linger l;
-       struct  timeval tv;
-#if CONFIG_MACF_SOCKET
-       struct mac extmac;
-#endif /* MAC_SOCKET */
-
-       if (sopt->sopt_dir != SOPT_GET)
+       int     error, optval;
+       struct  linger l;
+       struct  timeval tv;
+
+       if (sopt->sopt_dir != SOPT_GET) {
                sopt->sopt_dir = SOPT_GET;
+       }
 
-       if (dolock)
+       if (dolock) {
                socket_lock(so, 1);
+       }
 
        error = sflt_getsockopt(so, sopt);
        if (error != 0) {
-               if (error == EJUSTRETURN)
+               if (error == EJUSTRETURN) {
                        error = 0;
+               }
                goto out;
        }
 
@@ -5324,8 +5836,9 @@ sogetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                 * return value indicates that the option is unsupported.
                 */
                if (so->so_proto != NULL && (error = so->so_proto->pr_usrreqs->
-                   pru_socheckopt(so, sopt)) != 0)
+                   pru_socheckopt(so, sopt)) != 0) {
                        goto out;
+               }
 
                error = 0;
                switch (sopt->sopt_name) {
@@ -5334,7 +5847,7 @@ sogetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                        l.l_onoff = ((so->so_options & SO_LINGER) ? 1 : 0);
                        l.l_linger = (sopt->sopt_name == SO_LINGER) ?
                            so->so_linger : so->so_linger / hz;
-                       error = sooptcopyout(sopt, &l, sizeof (l));
+                       error = sooptcopyout(sopt, &l, sizeof(l));
                        break;
 
                case SO_USELOOPBACK:
@@ -5347,6 +5860,7 @@ sogetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                case SO_OOBINLINE:
                case SO_TIMESTAMP:
                case SO_TIMESTAMP_MONOTONIC:
+               case SO_TIMESTAMP_CONTINUOUS:
                case SO_DONTTRUNC:
                case SO_WANTMORE:
                case SO_WANTOOBFLAG:
@@ -5354,7 +5868,7 @@ sogetoptlock(struct socket *so, struct sockopt *sopt, int dolock)
                case SO_NOAPNFALLBK:
                        optval = so->so_options & sopt->sopt_name;
 integer:
-                       error = sooptcopyout(sopt, &optval, sizeof (optval));
+                       error = sooptcopyout(sopt, &optval, sizeof(optval));
                        break;
 
                case SO_TYPE:
@@ -5371,8 +5885,9 @@ integer:
                                while (m1 != NULL) {
                                        if (m1->m_type == MT_DATA ||
                                            m1->m_type == MT_HEADER ||
-                                           m1->m_type == MT_OOBDATA)
+                                           m1->m_type == MT_OOBDATA) {
                                                pkt_total += m1->m_len;
+                                       }
                                        m1 = m1->m_next;
                                }
                                optval = pkt_total;
@@ -5388,16 +5903,13 @@ integer:
 
                                m1 = so->so_rcv.sb_mb;
                                while (m1 != NULL) {
-                                       if (m1->m_type == MT_DATA ||
-                                           m1->m_type == MT_HEADER ||
-                                           m1->m_type == MT_OOBDATA)
-                                               cnt += 1;
+                                       cnt += 1;
                                        m1 = m1->m_nextpkt;
                                }
                                optval = cnt;
                                goto integer;
                        } else {
-                               error = EINVAL;
+                               error = ENOPROTOOPT;
                                break;
                        }
 
@@ -5469,47 +5981,29 @@ integer:
                        if (SOCK_DOM(so) == PF_INET ||
                            SOCK_DOM(so) == PF_INET6) {
                                optval = inp_get_awdl_unrestricted(
-                                   sotoinpcb(so));
+                                       sotoinpcb(so));
                                goto integer;
-                       } else
+                       } else {
                                error = EOPNOTSUPP;
+                       }
                        break;
 
                case SO_INTCOPROC_ALLOW:
                        if (SOCK_DOM(so) == PF_INET6) {
                                optval = inp_get_intcoproc_allowed(
-                                   sotoinpcb(so));
+                                       sotoinpcb(so));
                                goto integer;
-                       } else
+                       } else {
                                error = EOPNOTSUPP;
+                       }
                        break;
 
                case SO_LABEL:
-#if CONFIG_MACF_SOCKET
-                       if ((error = sooptcopyin(sopt, &extmac, sizeof (extmac),
-                           sizeof (extmac))) != 0 ||
-                           (error = mac_socket_label_get(proc_ucred(
-                           sopt->sopt_p), so, &extmac)) != 0)
-                               break;
-
-                       error = sooptcopyout(sopt, &extmac, sizeof (extmac));
-#else
                        error = EOPNOTSUPP;
-#endif /* MAC_SOCKET */
                        break;
 
                case SO_PEERLABEL:
-#if CONFIG_MACF_SOCKET
-                       if ((error = sooptcopyin(sopt, &extmac, sizeof (extmac),
-                           sizeof (extmac))) != 0 ||
-                           (error = mac_socketpeer_label_get(proc_ucred(
-                           sopt->sopt_p), so, &extmac)) != 0)
-                               break;
-
-                       error = sooptcopyout(sopt, &extmac, sizeof (extmac));
-#else
                        error = EOPNOTSUPP;
-#endif /* MAC_SOCKET */
                        break;
 
 #ifdef __APPLE_API_PRIVATE
@@ -5522,14 +6016,14 @@ integer:
                        goto integer;
 
                case SO_NP_EXTENSIONS: {
-                       struct so_np_extensions sonpx;
+                       struct so_np_extensions sonpx = {};
 
                        sonpx.npx_flags = (so->so_flags & SOF_NPX_SETOPTSHUT) ?
                            SONPX_SETOPTSHUT : 0;
                        sonpx.npx_mask = SONPX_MASK_VALID;
 
                        error = sooptcopyout(sopt, &sonpx,
-                           sizeof (struct so_np_extensions));
+                           sizeof(struct so_np_extensions));
                        break;
                }
 
@@ -5541,11 +6035,6 @@ integer:
                        optval = (so->so_flags & SOF_RECV_TRAFFIC_CLASS);
                        goto integer;
 
-               case SO_TRAFFIC_CLASS_STATS:
-                       error = sooptcopyout(sopt, &so->so_tc_stats,
-                           sizeof (so->so_tc_stats));
-                       break;
-
 #if (DEVELOPMENT || DEBUG)
                case SO_TRAFFIC_CLASS_DBG:
                        error = sogetopt_tcdbg(so, sopt);
@@ -5589,12 +6078,47 @@ integer:
                case SO_FLOW_DIVERT_TOKEN:
                        error = flow_divert_token_get(so, sopt);
                        break;
-#endif /* FLOW_DIVERT */
+#endif  /* FLOW_DIVERT */
 
 #if NECP
                case SO_NECP_ATTRIBUTES:
                        error = necp_get_socket_attributes(so, sopt);
                        break;
+
+               case SO_NECP_CLIENTUUID: {
+                       uuid_t *ncu;
+
+                       if (SOCK_DOM(so) == PF_MULTIPATH) {
+                               ncu = &mpsotomppcb(so)->necp_client_uuid;
+                       } else if (SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6) {
+                               ncu = &sotoinpcb(so)->necp_client_uuid;
+                       } else {
+                               error = EINVAL;
+                               goto out;
+                       }
+
+                       error = sooptcopyout(sopt, ncu, sizeof(uuid_t));
+                       break;
+               }
+
+               case SO_NECP_LISTENUUID: {
+                       uuid_t *nlu;
+
+                       if (SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6) {
+                               if (sotoinpcb(so)->inp_flags2 & INP2_EXTERNAL_PORT) {
+                                       nlu = &sotoinpcb(so)->necp_client_uuid;
+                               } else {
+                                       error = ENOENT;
+                                       goto out;
+                               }
+                       } else {
+                               error = EINVAL;
+                               goto out;
+                       }
+
+                       error = sooptcopyout(sopt, nlu, sizeof(uuid_t));
+                       break;
+               }
 #endif /* NECP */
 
 #if CONTENT_FILTER
@@ -5604,23 +6128,10 @@ integer:
                        sock_id = cfil_sock_id_from_socket(so);
 
                        error = sooptcopyout(sopt, &sock_id,
-                               sizeof(cfil_sock_id_t));
+                           sizeof(cfil_sock_id_t));
                        break;
                }
-#endif /* CONTENT_FILTER */
-
-#if MPTCP
-               case SO_MPTCP_FASTJOIN:
-                       if (!((so->so_flags & SOF_MP_SUBFLOW) ||
-                           ((SOCK_CHECK_DOM(so, PF_MULTIPATH)) &&
-                           (SOCK_CHECK_PROTO(so, IPPROTO_TCP))))) {
-                               error = ENOPROTOOPT;
-                               break;
-                       }
-                       optval = (so->so_flags & SOF_MPTCP_FASTJOIN);
-                       /* Fixed along with rdar://19391339 */
-                       goto integer;
-#endif /* MPTCP */
+#endif  /* CONTENT_FILTER */
 
                case SO_EXTENDED_BK_IDLE:
                        optval = (so->so_flags1 & SOF1_EXTEND_BK_IDLE_WANTED);
@@ -5630,25 +6141,36 @@ integer:
                            ? 1 : 0;
                        goto integer;
                case SO_NET_SERVICE_TYPE: {
-                       if ((so->so_flags1 & SOF1_TC_NET_SERV_TYPE))
+                       if ((so->so_flags1 & SOF1_TC_NET_SERV_TYPE)) {
                                optval = so->so_netsvctype;
-                       else
+                       } else {
                                optval = NET_SERVICE_TYPE_BE;
+                       }
                        goto integer;
                }
                case SO_NETSVC_MARKING_LEVEL:
                        optval = so_get_netsvc_marking_level(so);
                        goto integer;
 
+               case SO_MPKL_SEND_INFO: {
+                       struct so_mpkl_send_info so_mpkl_send_info;
+
+                       uuid_copy(so_mpkl_send_info.mpkl_uuid, so->so_mpkl_send_uuid);
+                       so_mpkl_send_info.mpkl_proto = so->so_mpkl_send_proto;
+                       error = sooptcopyout(sopt, &so_mpkl_send_info,
+                           sizeof(struct so_mpkl_send_info));
+                       break;
+               }
                default:
                        error = ENOPROTOOPT;
                        break;
                }
        }
 out:
-       if (dolock)
+       if (dolock) {
                socket_unlock(so, 1);
-       return (error);
+       }
+       return error;
 }
 
 /*
@@ -5663,18 +6185,20 @@ soopt_getm(struct sockopt *sopt, struct mbuf **mp)
        int sopt_size = sopt->sopt_valsize;
        int how;
 
-       if (sopt_size <= 0 || sopt_size > MCLBYTES)
-               return (EMSGSIZE);
+       if (sopt_size <= 0 || sopt_size > MCLBYTES) {
+               return EMSGSIZE;
+       }
 
        how = sopt->sopt_p != kernproc ? M_WAIT : M_DONTWAIT;
        MGET(m, how, MT_DATA);
-       if (m == NULL)
-               return (ENOBUFS);
+       if (m == NULL) {
+               return ENOBUFS;
+       }
        if (sopt_size > MLEN) {
                MCLGET(m, how);
                if ((m->m_flags & M_EXT) == 0) {
                        m_free(m);
-                       return (ENOBUFS);
+                       return ENOBUFS;
                }
                m->m_len = min(MCLBYTES, sopt_size);
        } else {
@@ -5688,14 +6212,14 @@ soopt_getm(struct sockopt *sopt, struct mbuf **mp)
                MGET(m, how, MT_DATA);
                if (m == NULL) {
                        m_freem(*mp);
-                       return (ENOBUFS);
+                       return ENOBUFS;
                }
                if (sopt_size > MLEN) {
                        MCLGET(m, how);
                        if ((m->m_flags & M_EXT) == 0) {
                                m_freem(*mp);
                                m_freem(m);
-                               return (ENOBUFS);
+                               return ENOBUFS;
                        }
                        m->m_len = min(MCLBYTES, sopt_size);
                } else {
@@ -5705,7 +6229,7 @@ soopt_getm(struct sockopt *sopt, struct mbuf **mp)
                m_prev->m_next = m;
                m_prev = m;
        }
-       return (0);
+       return 0;
 }
 
 /* copyin sopt data into mbuf chain */
@@ -5714,8 +6238,9 @@ soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
 {
        struct mbuf *m0 = m;
 
-       if (sopt->sopt_val == USER_ADDR_NULL)
-               return (0);
+       if (sopt->sopt_val == USER_ADDR_NULL) {
+               return 0;
+       }
        while (m != NULL && sopt->sopt_valsize >= m->m_len) {
                if (sopt->sopt_p != kernproc) {
                        int error;
@@ -5724,7 +6249,7 @@ soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
                            m->m_len);
                        if (error != 0) {
                                m_freem(m0);
-                               return (error);
+                               return error;
                        }
                } else {
                        bcopy(CAST_DOWN(caddr_t, sopt->sopt_val),
@@ -5739,7 +6264,7 @@ soopt_mcopyin(struct sockopt *sopt, struct mbuf *m)
                panic("soopt_mcopyin");
                /* NOTREACHED */
        }
-       return (0);
+       return 0;
 }
 
 /* copyout mbuf chain data into soopt */
@@ -5749,8 +6274,9 @@ soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
        struct mbuf *m0 = m;
        size_t valsize = 0;
 
-       if (sopt->sopt_val == USER_ADDR_NULL)
-               return (0);
+       if (sopt->sopt_val == USER_ADDR_NULL) {
+               return 0;
+       }
        while (m != NULL && sopt->sopt_valsize >= m->m_len) {
                if (sopt->sopt_p != kernproc) {
                        int error;
@@ -5759,7 +6285,7 @@ soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
                            m->m_len);
                        if (error != 0) {
                                m_freem(m0);
-                               return (error);
+                               return error;
                        }
                } else {
                        bcopy(mtod(m, char *),
@@ -5773,19 +6299,20 @@ soopt_mcopyout(struct sockopt *sopt, struct mbuf *m)
        if (m != NULL) {
                /* enough soopt buffer should be given from user-land */
                m_freem(m0);
-               return (EINVAL);
+               return EINVAL;
        }
        sopt->sopt_valsize = valsize;
-       return (0);
+       return 0;
 }
 
 void
 sohasoutofband(struct socket *so)
 {
-       if (so->so_pgid < 0)
+       if (so->so_pgid < 0) {
                gsignal(-so->so_pgid, SIGURG);
-       else if (so->so_pgid > 0)
+       } else if (so->so_pgid > 0) {
                proc_signal(so->so_pgid, SIGURG);
+       }
        selwakeup(&so->so_rcv.sb_sel);
        if (so->so_rcv.sb_flags & SB_KNOTE) {
                KNOTE(&so->so_rcv.sb_sel.si_note,
@@ -5804,17 +6331,23 @@ sopoll(struct socket *so, int events, kauth_cred_t cred, void * wql)
        so_update_last_owner_locked(so, PROC_NULL);
        so_update_policy(so);
 
-       if (events & (POLLIN | POLLRDNORM))
-               if (soreadable(so))
+       if (events & (POLLIN | POLLRDNORM)) {
+               if (soreadable(so)) {
                        revents |= events & (POLLIN | POLLRDNORM);
+               }
+       }
 
-       if (events & (POLLOUT | POLLWRNORM))
-               if (sowriteable(so))
+       if (events & (POLLOUT | POLLWRNORM)) {
+               if (sowriteable(so)) {
                        revents |= events & (POLLOUT | POLLWRNORM);
+               }
+       }
 
-       if (events & (POLLPRI | POLLRDBAND))
-               if (so->so_oobmark || (so->so_state & SS_RCVATMARK))
+       if (events & (POLLPRI | POLLRDBAND)) {
+               if (so->so_oobmark || (so->so_state & SS_RCVATMARK)) {
                        revents |= events & (POLLPRI | POLLRDBAND);
+               }
+       }
 
        if (revents == 0) {
                if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND)) {
@@ -5837,33 +6370,19 @@ sopoll(struct socket *so, int events, kauth_cred_t cred, void * wql)
        }
 
        socket_unlock(so, 1);
-       return (revents);
+       return revents;
 }
 
 int
-soo_kqfilter(struct fileproc *fp, struct knote *kn, vfs_context_t ctx)
+soo_kqfilter(struct fileproc *fp, struct knote *kn, struct kevent_qos_s *kev)
 {
-#pragma unused(fp)
-#if !CONFIG_MACF_SOCKET
-#pragma unused(ctx)
-#endif /* MAC_SOCKET */
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)fp->fp_glob->fg_data;
        int result;
 
        socket_lock(so, 1);
        so_update_last_owner_locked(so, PROC_NULL);
        so_update_policy(so);
 
-#if CONFIG_MACF_SOCKET
-       if (mac_socket_check_kqfilter(proc_ucred(vfs_context_proc(ctx)),
-           kn, so) != 0) {
-               socket_unlock(so, 1);
-               kn->kn_flags = EV_ERROR;
-               kn->kn_data = EPERM;
-               return 0;
-       }
-#endif /* MAC_SOCKET */
-
        switch (kn->kn_filter) {
        case EVFILT_READ:
                kn->kn_filtid = EVFILTID_SOREAD;
@@ -5879,8 +6398,7 @@ soo_kqfilter(struct fileproc *fp, struct knote *kn, vfs_context_t ctx)
                break;
        default:
                socket_unlock(so, 1);
-               kn->kn_flags = EV_ERROR;
-               kn->kn_data = EINVAL;
+               knote_set_error(kn, EINVAL);
                return 0;
        }
 
@@ -5888,7 +6406,7 @@ soo_kqfilter(struct fileproc *fp, struct knote *kn, vfs_context_t ctx)
         * call the appropriate sub-filter attach
         * with the socket still locked
         */
-       result = knote_fops(kn)->f_attach(kn);
+       result = knote_fops(kn)->f_attach(kn, kev);
 
        socket_unlock(so, 1);
 
@@ -5896,21 +6414,21 @@ soo_kqfilter(struct fileproc *fp, struct knote *kn, vfs_context_t ctx)
 }
 
 static int
-filt_soread_common(struct knote *kn, struct socket *so)
+filt_soread_common(struct knote *kn, struct kevent_qos_s *kev, struct socket *so)
 {
-       if (so->so_options & SO_ACCEPTCONN) {
-               int is_not_empty;
+       int retval = 0;
+       int64_t data = 0;
 
+       if (so->so_options & SO_ACCEPTCONN) {
                /*
                 * Radar 6615193 handle the listen case dynamically
                 * for kqueue read filter. This allows to call listen()
                 * after registering the kqueue EVFILT_READ.
                 */
 
-               kn->kn_data = so->so_qlen;
-               is_not_empty = ! TAILQ_EMPTY(&so->so_comp);
-
-               return (is_not_empty);
+               retval = !TAILQ_EMPTY(&so->so_comp);
+               data = so->so_qlen;
+               goto out;
        }
 
        /* socket isn't a listener */
@@ -5919,13 +6437,14 @@ filt_soread_common(struct knote *kn, struct socket *so)
         * the bytes of protocol data. We therefore exclude any
         * control bytes.
         */
-       kn->kn_data = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
+       data = so->so_rcv.sb_cc - so->so_rcv.sb_ctl;
 
        if (kn->kn_sfflags & NOTE_OOB) {
                if (so->so_oobmark || (so->so_state & SS_RCVATMARK)) {
                        kn->kn_fflags |= NOTE_OOB;
-                       kn->kn_data -= so->so_oobmark;
-                       return (1);
+                       data -= so->so_oobmark;
+                       retval = 1;
+                       goto out;
                }
        }
 
@@ -5933,44 +6452,50 @@ filt_soread_common(struct knote *kn, struct socket *so)
 #if CONTENT_FILTER
            && cfil_sock_data_pending(&so->so_rcv) == 0
 #endif /* CONTENT_FILTER */
-          ) {
+           ) {
                kn->kn_flags |= EV_EOF;
                kn->kn_fflags = so->so_error;
-               return (1);
+               retval = 1;
+               goto out;
        }
 
-       if (so->so_error) {     /* temporary udp error */
-               return (1);
+       if (so->so_error) {     /* temporary udp error */
+               retval = 1;
+               goto out;
        }
 
-       int64_t lowwat = so->so_rcv.sb_lowat;
+       int64_t lowwat = so->so_rcv.sb_lowat;
        /*
         * Ensure that when NOTE_LOWAT is used, the derived
         * low water mark is bounded by socket's rcv buf's
         * high and low water mark values.
         */
        if (kn->kn_sfflags & NOTE_LOWAT) {
-               if (kn->kn_sdata > so->so_rcv.sb_hiwat)
+               if (kn->kn_sdata > so->so_rcv.sb_hiwat) {
                        lowwat = so->so_rcv.sb_hiwat;
-               else if (kn->kn_sdata > lowwat)
+               } else if (kn->kn_sdata > lowwat) {
                        lowwat = kn->kn_sdata;
+               }
        }
 
        /*
-        * The order below is important. Since NOTE_LOWAT
-        * overrides sb_lowat, check for NOTE_LOWAT case
-        * first.
+        * While the `data` field is the amount of data to read,
+        * 0-sized packets need to wake up the kqueue, see 58140856,
+        * so we need to take control bytes into account too.
         */
-       if (kn->kn_sfflags & NOTE_LOWAT)
-               return (kn->kn_data >= lowwat);
+       retval = (so->so_rcv.sb_cc >= lowwat);
 
-       return (so->so_rcv.sb_cc >= lowwat);
+out:
+       if (retval && kev) {
+               knote_fill_kevent(kn, kev, data);
+       }
+       return retval;
 }
 
 static int
-filt_sorattach(struct knote *kn)
+filt_sorattach(struct knote *kn, __unused struct kevent_qos_s *kev)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
 
        /* socket locked */
 
@@ -5982,26 +6507,29 @@ filt_sorattach(struct knote *kn)
        if (kn->kn_filter == EVFILT_READ &&
            kn->kn_flags & EV_OOBAND) {
                kn->kn_flags &= ~EV_OOBAND;
-               kn->kn_hookid = EV_OOBAND;
+               kn->kn_hook32 = EV_OOBAND;
        } else {
-               kn->kn_hookid = 0;
+               kn->kn_hook32 = 0;
        }
-       if (KNOTE_ATTACH(&so->so_rcv.sb_sel.si_note, kn))
+       if (KNOTE_ATTACH(&so->so_rcv.sb_sel.si_note, kn)) {
                so->so_rcv.sb_flags |= SB_KNOTE;
+       }
 
        /* indicate if event is already fired */
-       return filt_soread_common(kn, so);
+       return filt_soread_common(kn, NULL, so);
 }
 
 static void
 filt_sordetach(struct knote *kn)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
 
        socket_lock(so, 1);
-       if (so->so_rcv.sb_flags & SB_KNOTE)
-               if (KNOTE_DETACH(&so->so_rcv.sb_sel.si_note, kn))
+       if (so->so_rcv.sb_flags & SB_KNOTE) {
+               if (KNOTE_DETACH(&so->so_rcv.sb_sel.si_note, kn)) {
                        so->so_rcv.sb_flags &= ~SB_KNOTE;
+               }
+       }
        socket_unlock(so, 1);
 }
 
@@ -6009,24 +6537,26 @@ filt_sordetach(struct knote *kn)
 static int
 filt_soread(struct knote *kn, long hint)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        int retval;
 
-       if ((hint & SO_FILT_HINT_LOCKED) == 0)
+       if ((hint & SO_FILT_HINT_LOCKED) == 0) {
                socket_lock(so, 1);
+       }
 
-       retval = filt_soread_common(kn, so);
+       retval = filt_soread_common(kn, NULL, so);
 
-       if ((hint & SO_FILT_HINT_LOCKED) == 0)
+       if ((hint & SO_FILT_HINT_LOCKED) == 0) {
                socket_unlock(so, 1);
+       }
 
        return retval;
 }
 
 static int
-filt_sortouch(struct knote *kn, struct kevent_internal_s *kev)
+filt_sortouch(struct knote *kn, struct kevent_qos_s *kev)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        int retval;
 
        socket_lock(so, 1);
@@ -6034,11 +6564,9 @@ filt_sortouch(struct knote *kn, struct kevent_internal_s *kev)
        /* save off the new input fflags and data */
        kn->kn_sfflags = kev->fflags;
        kn->kn_sdata = kev->data;
-       if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0)
-               kn->kn_udata = kev->udata;
 
        /* determine if changes result in fired events */
-       retval = filt_soread_common(kn, so);
+       retval = filt_soread_common(kn, NULL, so);
 
        socket_unlock(so, 1);
 
@@ -6046,21 +6574,13 @@ filt_sortouch(struct knote *kn, struct kevent_internal_s *kev)
 }
 
 static int
-filt_sorprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev)
+filt_sorprocess(struct knote *kn, struct kevent_qos_s *kev)
 {
-#pragma unused(data)
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        int retval;
 
        socket_lock(so, 1);
-       retval = filt_soread_common(kn, so);
-       if (retval) {
-               *kev = kn->kn_kevent;
-               if (kn->kn_flags & EV_CLEAR) {
-                       kn->kn_fflags = 0;
-                       kn->kn_data = 0;
-               }
-       }
+       retval = filt_soread_common(kn, kev, so);
        socket_unlock(so, 1);
 
        return retval;
@@ -6072,40 +6592,52 @@ so_wait_for_if_feedback(struct socket *so)
        if ((SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6) &&
            (so->so_state & SS_ISCONNECTED)) {
                struct inpcb *inp = sotoinpcb(so);
-               if (INP_WAIT_FOR_IF_FEEDBACK(inp))
-                       return (1);
+               if (INP_WAIT_FOR_IF_FEEDBACK(inp)) {
+                       return 1;
+               }
        }
-       return (0);
+       return 0;
 }
 
 static int
-filt_sowrite_common(struct knote *kn, struct socket *so)
+filt_sowrite_common(struct knote *kn, struct kevent_qos_s *kev, struct socket *so)
 {
        int ret = 0;
+       int64_t data = sbspace(&so->so_snd);
 
-       kn->kn_data = sbspace(&so->so_snd);
        if (so->so_state & SS_CANTSENDMORE) {
                kn->kn_flags |= EV_EOF;
                kn->kn_fflags = so->so_error;
-               return 1;
+               ret = 1;
+               goto out;
        }
-       if (so->so_error) {     /* temporary udp error */
-               return 1;
+
+       if (so->so_error) {     /* temporary udp error */
+               ret = 1;
+               goto out;
        }
+
        if (!socanwrite(so)) {
-               return 0;
+               ret = 0;
+               goto out;
        }
+
        if (so->so_flags1 & SOF1_PRECONNECT_DATA) {
-               return 1;
+               ret = 1;
+               goto out;
        }
-       int64_t lowwat = so->so_snd.sb_lowat;
+
+       int64_t lowwat = so->so_snd.sb_lowat;
+
        if (kn->kn_sfflags & NOTE_LOWAT) {
-               if (kn->kn_sdata > so->so_snd.sb_hiwat)
+               if (kn->kn_sdata > so->so_snd.sb_hiwat) {
                        lowwat = so->so_snd.sb_hiwat;
-               else if (kn->kn_sdata > lowwat)
+               } else if (kn->kn_sdata > lowwat) {
                        lowwat = kn->kn_sdata;
+               }
        }
-       if (kn->kn_data >= lowwat) {
+
+       if (data >= lowwat) {
                if ((so->so_flags & SOF_NOTSENT_LOWAT)
 #if (DEBUG || DEVELOPMENT)
                    && so_notsent_lowat_check == 1
@@ -6123,39 +6655,49 @@ filt_sowrite_common(struct knote *kn, struct socket *so)
                        }
 #endif
                        else {
-                               return 1;
+                               ret = 1;
+                               goto out;
                        }
                } else {
                        ret = 1;
                }
        }
-       if (so_wait_for_if_feedback(so))
+       if (so_wait_for_if_feedback(so)) {
                ret = 0;
-       return (ret);
+       }
+
+out:
+       if (ret && kev) {
+               knote_fill_kevent(kn, kev, data);
+       }
+       return ret;
 }
 
 static int
-filt_sowattach(struct knote *kn)
+filt_sowattach(struct knote *kn, __unused struct kevent_qos_s *kev)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
 
        /* socket locked */
-       if (KNOTE_ATTACH(&so->so_snd.sb_sel.si_note, kn))
+       if (KNOTE_ATTACH(&so->so_snd.sb_sel.si_note, kn)) {
                so->so_snd.sb_flags |= SB_KNOTE;
+       }
 
        /* determine if its already fired */
-       return filt_sowrite_common(kn, so);
+       return filt_sowrite_common(kn, NULL, so);
 }
 
 static void
 filt_sowdetach(struct knote *kn)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        socket_lock(so, 1);
 
-       if (so->so_snd.sb_flags & SB_KNOTE)
-               if (KNOTE_DETACH(&so->so_snd.sb_sel.si_note, kn))
+       if (so->so_snd.sb_flags & SB_KNOTE) {
+               if (KNOTE_DETACH(&so->so_snd.sb_sel.si_note, kn)) {
                        so->so_snd.sb_flags &= ~SB_KNOTE;
+               }
+       }
        socket_unlock(so, 1);
 }
 
@@ -6163,24 +6705,26 @@ filt_sowdetach(struct knote *kn)
 static int
 filt_sowrite(struct knote *kn, long hint)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        int ret;
 
-       if ((hint & SO_FILT_HINT_LOCKED) == 0)
+       if ((hint & SO_FILT_HINT_LOCKED) == 0) {
                socket_lock(so, 1);
+       }
 
-       ret = filt_sowrite_common(kn, so);
+       ret = filt_sowrite_common(kn, NULL, so);
 
-       if ((hint & SO_FILT_HINT_LOCKED) == 0)
+       if ((hint & SO_FILT_HINT_LOCKED) == 0) {
                socket_unlock(so, 1);
+       }
 
        return ret;
 }
 
 static int
-filt_sowtouch(struct knote *kn, struct kevent_internal_s *kev)
+filt_sowtouch(struct knote *kn, struct kevent_qos_s *kev)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        int ret;
 
        socket_lock(so, 1);
@@ -6188,11 +6732,9 @@ filt_sowtouch(struct knote *kn, struct kevent_internal_s *kev)
        /*save off the new input fflags and data */
        kn->kn_sfflags = kev->fflags;
        kn->kn_sdata = kev->data;
-       if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0)
-               kn->kn_udata = kev->udata;
 
        /* determine if these changes result in a triggered event */
-       ret = filt_sowrite_common(kn, so);
+       ret = filt_sowrite_common(kn, NULL, so);
 
        socket_unlock(so, 1);
 
@@ -6200,29 +6742,24 @@ filt_sowtouch(struct knote *kn, struct kevent_internal_s *kev)
 }
 
 static int
-filt_sowprocess(struct knote *kn, struct filt_process_s *data, struct kevent_internal_s *kev)
+filt_sowprocess(struct knote *kn, struct kevent_qos_s *kev)
 {
-#pragma unused(data)
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        int ret;
 
        socket_lock(so, 1);
-       ret = filt_sowrite_common(kn, so);
-       if (ret) {
-               *kev = kn->kn_kevent;
-               if (kn->kn_flags & EV_CLEAR) {
-                       kn->kn_fflags = 0;
-                       kn->kn_data = 0;
-               }
-       }
+       ret = filt_sowrite_common(kn, kev, so);
        socket_unlock(so, 1);
+
        return ret;
 }
 
 static int
-filt_sockev_common(struct knote *kn, struct socket *so, long ev_hint)
+filt_sockev_common(struct knote *kn, struct kevent_qos_s *kev,
+    struct socket *so, long ev_hint)
 {
        int ret = 0;
+       int64_t data = 0;
        uint32_t level_trigger = 0;
 
        if (ev_hint & SO_FILT_HINT_CONNRESET) {
@@ -6258,8 +6795,9 @@ filt_sockev_common(struct knote *kn, struct socket *so, long ev_hint)
        }
        if (ev_hint & SO_FILT_HINT_CONNINFO_UPDATED) {
                if (so->so_proto != NULL &&
-                   (so->so_proto->pr_flags & PR_EVCONNINFO))
+                   (so->so_proto->pr_flags & PR_EVCONNINFO)) {
                        kn->kn_fflags |= NOTE_CONNINFO_UPDATED;
+               }
        }
 
        if ((ev_hint & SO_FILT_HINT_NOTIFY_ACK) ||
@@ -6286,7 +6824,7 @@ filt_sockev_common(struct knote *kn, struct socket *so, long ev_hint)
                kn->kn_fflags &= ~(NOTE_SUSPEND | NOTE_RESUME);
 
                /* If resume event was delivered before, reset it */
-               kn->kn_hookid &= ~NOTE_RESUME;
+               kn->kn_hook32 &= ~NOTE_RESUME;
 
                kn->kn_fflags |= NOTE_SUSPEND;
                level_trigger |= NOTE_SUSPEND;
@@ -6297,7 +6835,7 @@ filt_sockev_common(struct knote *kn, struct socket *so, long ev_hint)
                kn->kn_fflags &= ~(NOTE_SUSPEND | NOTE_RESUME);
 
                /* If suspend event was delivered before, reset it */
-               kn->kn_hookid &= ~NOTE_SUSPEND;
+               kn->kn_hook32 &= ~NOTE_SUSPEND;
 
                kn->kn_fflags |= NOTE_RESUME;
                level_trigger |= NOTE_RESUME;
@@ -6305,10 +6843,12 @@ filt_sockev_common(struct knote *kn, struct socket *so, long ev_hint)
 
        if (so->so_error != 0) {
                ret = 1;
-               kn->kn_data = so->so_error;
+               data = so->so_error;
                kn->kn_flags |= EV_EOF;
        } else {
-               get_sockev_state(so, (u_int32_t *)&(kn->kn_data));
+               u_int32_t data32 = 0;
+               get_sockev_state(so, &data32);
+               data = data32;
        }
 
        /* Reset any events that are not requested on this knote */
@@ -6316,39 +6856,69 @@ filt_sockev_common(struct knote *kn, struct socket *so, long ev_hint)
        level_trigger &= (kn->kn_sfflags & EVFILT_SOCK_ALL_MASK);
 
        /* Find the level triggerred events that are already delivered */
-       level_trigger &= kn->kn_hookid;
+       level_trigger &= kn->kn_hook32;
        level_trigger &= EVFILT_SOCK_LEVEL_TRIGGER_MASK;
 
        /* Do not deliver level triggerred events more than once */
-       if ((kn->kn_fflags & ~level_trigger) != 0)
+       if ((kn->kn_fflags & ~level_trigger) != 0) {
                ret = 1;
+       }
+
+       if (ret && kev) {
+               /*
+                * Store the state of the events being delivered. This
+                * state can be used to deliver level triggered events
+                * ateast once and still avoid waking up the application
+                * multiple times as long as the event is active.
+                */
+               if (kn->kn_fflags != 0) {
+                       kn->kn_hook32 |= (kn->kn_fflags &
+                           EVFILT_SOCK_LEVEL_TRIGGER_MASK);
+               }
+
+               /*
+                * NOTE_RESUME and NOTE_SUSPEND are an exception, deliver
+                * only one of them and remember the last one that was
+                * delivered last
+                */
+               if (kn->kn_fflags & NOTE_SUSPEND) {
+                       kn->kn_hook32 &= ~NOTE_RESUME;
+               }
+               if (kn->kn_fflags & NOTE_RESUME) {
+                       kn->kn_hook32 &= ~NOTE_SUSPEND;
+               }
 
-       return (ret);
+               knote_fill_kevent(kn, kev, data);
+       }
+       return ret;
 }
 
 static int
-filt_sockattach(struct knote *kn)
+filt_sockattach(struct knote *kn, __unused struct kevent_qos_s *kev)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
 
        /* socket locked */
-       kn->kn_hookid = 0;
-       if (KNOTE_ATTACH(&so->so_klist, kn))
+       kn->kn_hook32 = 0;
+       if (KNOTE_ATTACH(&so->so_klist, kn)) {
                so->so_flags |= SOF_KNOTE;
+       }
 
        /* determine if event already fired */
-       return filt_sockev_common(kn, so, 0);
+       return filt_sockev_common(kn, NULL, so, 0);
 }
 
 static void
 filt_sockdetach(struct knote *kn)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        socket_lock(so, 1);
 
-       if ((so->so_flags & SOF_KNOTE) != 0)
-               if (KNOTE_DETACH(&so->so_klist, kn))
+       if ((so->so_flags & SOF_KNOTE) != 0) {
+               if (KNOTE_DETACH(&so->so_klist, kn)) {
                        so->so_flags &= ~SOF_KNOTE;
+               }
+       }
        socket_unlock(so, 1);
 }
 
@@ -6356,7 +6926,7 @@ static int
 filt_sockev(struct knote *kn, long hint)
 {
        int ret = 0, locked = 0;
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        long ev_hint = (hint & SO_FILT_HINT_EV);
 
        if ((hint & SO_FILT_HINT_LOCKED) == 0) {
@@ -6364,10 +6934,11 @@ filt_sockev(struct knote *kn, long hint)
                locked = 1;
        }
 
-       ret = filt_sockev_common(kn, so, ev_hint);
+       ret = filt_sockev_common(kn, NULL, so, ev_hint);
 
-       if (locked)
+       if (locked) {
                socket_unlock(so, 1);
+       }
 
        return ret;
 }
@@ -6380,22 +6951,20 @@ filt_sockev(struct knote *kn, long hint)
 static int
 filt_socktouch(
        struct knote *kn,
-       struct kevent_internal_s *kev)
+       struct kevent_qos_s *kev)
 {
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        uint32_t changed_flags;
        int ret;
 
        socket_lock(so, 1);
 
        /* save off the [result] data and fflags */
-       changed_flags = (kn->kn_sfflags ^ kn->kn_hookid);
+       changed_flags = (kn->kn_sfflags ^ kn->kn_hook32);
 
        /* save off the new input fflags and data */
        kn->kn_sfflags = kev->fflags;
        kn->kn_sdata = kev->data;
-       if ((kn->kn_status & KN_UDATA_SPECIFIC) == 0)
-               kn->kn_udata = kev->udata;
 
        /* restrict the current results to the (smaller?) set of new interest */
        /*
@@ -6409,11 +6978,10 @@ filt_socktouch(
         * delivered, if any of those events are not requested
         * anymore the state related to them can be reset
         */
-       kn->kn_hookid &=
-           ~(changed_flags & EVFILT_SOCK_LEVEL_TRIGGER_MASK);
+       kn->kn_hook32 &= ~(changed_flags & EVFILT_SOCK_LEVEL_TRIGGER_MASK);
 
        /* determine if we have events to deliver */
-       ret = filt_sockev_common(kn, so, 0);
+       ret = filt_sockev_common(kn, NULL, so, 0);
 
        socket_unlock(so, 1);
 
@@ -6424,47 +6992,14 @@ filt_socktouch(
  *     filt_sockprocess - query event fired state and return data
  */
 static int
-filt_sockprocess(
-       struct knote *kn,
-       struct filt_process_s *data,
-       struct kevent_internal_s *kev)
+filt_sockprocess(struct knote *kn, struct kevent_qos_s *kev)
 {
-#pragma unused(data)
-
-       struct socket *so = (struct socket *)kn->kn_fp->f_fglob->fg_data;
+       struct socket *so = (struct socket *)kn->kn_fp->fp_glob->fg_data;
        int ret = 0;
 
        socket_lock(so, 1);
 
-       ret = filt_sockev_common(kn, so, 0);
-       if (ret) {
-               *kev = kn->kn_kevent;
-
-               /*
-                * Store the state of the events being delivered. This
-                * state can be used to deliver level triggered events
-                * ateast once and still avoid waking up the application
-                * multiple times as long as the event is active.
-                */
-               if (kn->kn_fflags != 0)
-                       kn->kn_hookid |= (kn->kn_fflags &
-                                         EVFILT_SOCK_LEVEL_TRIGGER_MASK);
-
-               /*
-                * NOTE_RESUME and NOTE_SUSPEND are an exception, deliver
-                * only one of them and remember the last one that was
-                * delivered last
-                */
-               if (kn->kn_fflags & NOTE_SUSPEND)
-                       kn->kn_hookid &= ~NOTE_RESUME;
-               if (kn->kn_fflags & NOTE_RESUME)
-                       kn->kn_hookid &= ~NOTE_SUSPEND;
-
-               if (kn->kn_flags & EV_CLEAR) {
-                       kn->kn_data = 0;
-                       kn->kn_fflags = 0;
-               }
-       }
+       ret = filt_sockev_common(kn, kev, so, 0);
 
        socket_unlock(so, 1);
 
@@ -6480,18 +7015,20 @@ get_sockev_state(struct socket *so, u_int32_t *statep)
         * If the state variable is already used by a previous event,
         * reset it.
         */
-       if (state != 0)
+       if (state != 0) {
                return;
+       }
 
-       if (so->so_state & SS_ISCONNECTED)
+       if (so->so_state & SS_ISCONNECTED) {
                state |= SOCKEV_CONNECTED;
-       else
+       } else {
                state &= ~(SOCKEV_CONNECTED);
+       }
        state |= ((so->so_state & SS_ISDISCONNECTED) ? SOCKEV_DISCONNECTED : 0);
        *(statep) = state;
 }
 
-#define        SO_LOCK_HISTORY_STR_LEN \
+#define SO_LOCK_HISTORY_STR_LEN \
        (2 * SO_LCKDBG_MAX * (2 + (2 * sizeof (void *)) + 1) + 1)
 
 __private_extern__ const char *
@@ -6501,64 +7038,99 @@ solockhistory_nr(struct socket *so)
        int i;
        static char lock_history_str[SO_LOCK_HISTORY_STR_LEN];
 
-       bzero(lock_history_str, sizeof (lock_history_str));
+       bzero(lock_history_str, sizeof(lock_history_str));
        for (i = SO_LCKDBG_MAX - 1; i >= 0; i--) {
-               n += snprintf(lock_history_str + n,
+               n += scnprintf(lock_history_str + n,
                    SO_LOCK_HISTORY_STR_LEN - n, "%p:%p ",
                    so->lock_lr[(so->next_lock_lr + i) % SO_LCKDBG_MAX],
                    so->unlock_lr[(so->next_unlock_lr + i) % SO_LCKDBG_MAX]);
        }
-       return (lock_history_str);
+       return lock_history_str;
 }
 
-int
+lck_mtx_t *
+socket_getlock(struct socket *so, int flags)
+{
+       if (so->so_proto->pr_getlock != NULL) {
+               return (*so->so_proto->pr_getlock)(so, flags);
+       } else {
+               return so->so_proto->pr_domain->dom_mtx;
+       }
+}
+
+void
 socket_lock(struct socket *so, int refcount)
 {
-       int error = 0;
        void *lr_saved;
 
        lr_saved = __builtin_return_address(0);
 
        if (so->so_proto->pr_lock) {
-               error = (*so->so_proto->pr_lock)(so, refcount, lr_saved);
+               (*so->so_proto->pr_lock)(so, refcount, lr_saved);
        } else {
 #ifdef MORE_LOCKING_DEBUG
-               lck_mtx_assert(so->so_proto->pr_domain->dom_mtx,
+               LCK_MTX_ASSERT(so->so_proto->pr_domain->dom_mtx,
                    LCK_MTX_ASSERT_NOTOWNED);
 #endif
                lck_mtx_lock(so->so_proto->pr_domain->dom_mtx);
-               if (refcount)
+               if (refcount) {
                        so->so_usecount++;
+               }
                so->lock_lr[so->next_lock_lr] = lr_saved;
-               so->next_lock_lr = (so->next_lock_lr+1) % SO_LCKDBG_MAX;
+               so->next_lock_lr = (so->next_lock_lr + 1) % SO_LCKDBG_MAX;
+       }
+}
+
+void
+socket_lock_assert_owned(struct socket *so)
+{
+       lck_mtx_t *mutex_held;
+
+       if (so->so_proto->pr_getlock != NULL) {
+               mutex_held = (*so->so_proto->pr_getlock)(so, 0);
+       } else {
+               mutex_held = so->so_proto->pr_domain->dom_mtx;
        }
 
-       return (error);
+       LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
 }
 
 int
+socket_try_lock(struct socket *so)
+{
+       lck_mtx_t *mtx;
+
+       if (so->so_proto->pr_getlock != NULL) {
+               mtx = (*so->so_proto->pr_getlock)(so, 0);
+       } else {
+               mtx = so->so_proto->pr_domain->dom_mtx;
+       }
+
+       return lck_mtx_try_lock(mtx);
+}
+
+void
 socket_unlock(struct socket *so, int refcount)
 {
-       int error = 0;
        void *lr_saved;
        lck_mtx_t *mutex_held;
 
        lr_saved = __builtin_return_address(0);
 
-       if (so->so_proto == NULL) {
+       if (so == NULL || so->so_proto == NULL) {
                panic("%s: null so_proto so=%p\n", __func__, so);
                /* NOTREACHED */
        }
 
-       if (so && so->so_proto->pr_unlock) {
-               error = (*so->so_proto->pr_unlock)(so, refcount, lr_saved);
+       if (so->so_proto->pr_unlock) {
+               (*so->so_proto->pr_unlock)(so, refcount, lr_saved);
        } else {
                mutex_held = so->so_proto->pr_domain->dom_mtx;
 #ifdef MORE_LOCKING_DEBUG
-               lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
+               LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
 #endif
                so->unlock_lr[so->next_unlock_lr] = lr_saved;
-               so->next_unlock_lr = (so->next_unlock_lr+1) % SO_LCKDBG_MAX;
+               so->next_unlock_lr = (so->next_unlock_lr + 1) % SO_LCKDBG_MAX;
 
                if (refcount) {
                        if (so->so_usecount <= 0) {
@@ -6570,13 +7142,12 @@ socket_unlock(struct socket *so, int refcount)
                        }
 
                        so->so_usecount--;
-                       if (so->so_usecount == 0)
+                       if (so->so_usecount == 0) {
                                sofreelastref(so, 1);
+                       }
                }
                lck_mtx_unlock(mutex_held);
        }
-
-       return (error);
 }
 
 /* Called with socket locked, will unlock socket */
@@ -6585,11 +7156,12 @@ sofree(struct socket *so)
 {
        lck_mtx_t *mutex_held;
 
-       if (so->so_proto->pr_getlock != NULL)
+       if (so->so_proto->pr_getlock != NULL) {
                mutex_held = (*so->so_proto->pr_getlock)(so, 0);
-       else
+       } else {
                mutex_held = so->so_proto->pr_domain->dom_mtx;
-       lck_mtx_assert(mutex_held, LCK_MTX_ASSERT_OWNED);
+       }
+       LCK_MTX_ASSERT(mutex_held, LCK_MTX_ASSERT_OWNED);
 
        sofreelastref(so, 0);
 }
@@ -6597,8 +7169,8 @@ sofree(struct socket *so)
 void
 soreference(struct socket *so)
 {
-       socket_lock(so, 1);     /* locks & take one reference on socket */
-       socket_unlock(so, 0);   /* unlock only */
+       socket_lock(so, 1);     /* locks & take one reference on socket */
+       socket_unlock(so, 0);   /* unlock only */
 }
 
 void
@@ -6616,32 +7188,35 @@ sodereference(struct socket *so)
 void
 somultipages(struct socket *so, boolean_t set)
 {
-       if (set)
+       if (set) {
                so->so_flags |= SOF_MULTIPAGES;
-       else
+       } else {
                so->so_flags &= ~SOF_MULTIPAGES;
+       }
 }
 
 void
 soif2kcl(struct socket *so, boolean_t set)
 {
-       if (set)
+       if (set) {
                so->so_flags1 |= SOF1_IF_2KCL;
-       else
+       } else {
                so->so_flags1 &= ~SOF1_IF_2KCL;
+       }
 }
 
 int
-so_isdstlocal(struct socket *so) {
-
+so_isdstlocal(struct socket *so)
+{
        struct inpcb *inp = (struct inpcb *)so->so_pcb;
 
-       if (SOCK_DOM(so) == PF_INET)
-               return (inaddr_local(inp->inp_faddr));
-       else if (SOCK_DOM(so) == PF_INET6)
-               return (in6addr_local(&inp->in6p_faddr));
+       if (SOCK_DOM(so) == PF_INET) {
+               return inaddr_local(inp->inp_faddr);
+       } else if (SOCK_DOM(so) == PF_INET6) {
+               return in6addr_local(&inp->in6p_faddr);
+       }
 
-       return (0);
+       return 0;
 }
 
 int
@@ -6665,23 +7240,29 @@ sosetdefunct(struct proc *p, struct socket *so, int level, boolean_t noforce)
        if (so->so_flags & SOF_NODEFUNCT) {
                if (noforce) {
                        err = EOPNOTSUPP;
+                       if (p != PROC_NULL) {
+                               SODEFUNCTLOG("%s[%d, %s]: (target pid %d "
+                                   "name %s level %d) so 0x%llx [%d,%d] "
+                                   "is not eligible for defunct "
+                                   "(%d)\n", __func__, proc_selfpid(),
+                                   proc_best_name(current_proc()), proc_pid(p),
+                                   proc_best_name(p), level,
+                                   (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
+                                   SOCK_DOM(so), SOCK_TYPE(so), err);
+                       }
+                       return err;
+               }
+               so->so_flags &= ~SOF_NODEFUNCT;
+               if (p != PROC_NULL) {
                        SODEFUNCTLOG("%s[%d, %s]: (target pid %d "
                            "name %s level %d) so 0x%llx [%d,%d] "
-                           "is not eligible for defunct "
+                           "defunct by force "
                            "(%d)\n", __func__, proc_selfpid(),
                            proc_best_name(current_proc()), proc_pid(p),
                            proc_best_name(p), level,
                            (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
                            SOCK_DOM(so), SOCK_TYPE(so), err);
-                       return (err);
                }
-               so->so_flags &= ~SOF_NODEFUNCT;
-               SODEFUNCTLOG("%s[%d, %s]: (target pid %d name %s level %d) "
-                   "so 0x%llx [%d,%d] defunct by force\n", __func__,
-                   proc_selfpid(), proc_best_name(current_proc()),
-                   proc_pid(p), proc_best_name(p), level,
-                   (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
-                   SOCK_DOM(so), SOCK_TYPE(so));
        } else if (so->so_flags1 & SOF1_EXTEND_BK_IDLE_WANTED) {
                struct inpcb *inp = (struct inpcb *)so->so_pcb;
                struct ifnet *ifp = inp->inp_last_outifp;
@@ -6692,7 +7273,7 @@ sosetdefunct(struct proc *p, struct socket *so, int level, boolean_t noforce)
                        OSIncrementAtomic(&soextbkidlestat.so_xbkidle_nodlgtd);
                } else if (soextbkidlestat.so_xbkidle_time == 0) {
                        OSIncrementAtomic(&soextbkidlestat.so_xbkidle_notime);
-               } else if (noforce) {
+               } else if (noforce && p != PROC_NULL) {
                        OSIncrementAtomic(&soextbkidlestat.so_xbkidle_active);
 
                        so->so_flags1 |= SOF1_EXTEND_BK_IDLE_INPROG;
@@ -6702,15 +7283,15 @@ sosetdefunct(struct proc *p, struct socket *so, int level, boolean_t noforce)
                        inpcb_timer_sched(inp->inp_pcbinfo, INPCB_TIMER_LAZY);
 
                        err = EOPNOTSUPP;
-                       SODEFUNCTLOG("%s[%d, %s]: (target pid %d name %s "
-                           "level %d) extend bk idle so 0x%llx rcv hw %d "
-                           "cc %d\n",
-                           __func__, proc_selfpid(),
+                       SODEFUNCTLOG("%s[%d, %s]: (target pid %d "
+                           "name %s level %d) so 0x%llx [%d,%d] "
+                           "extend bk idle "
+                           "(%d)\n", __func__, proc_selfpid(),
                            proc_best_name(current_proc()), proc_pid(p),
                            proc_best_name(p), level,
                            (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
-                           so->so_rcv.sb_hiwat, so->so_rcv.sb_cc);
-                       return (err);
+                           SOCK_DOM(so), SOCK_TYPE(so), err);
+                       return err;
                } else {
                        OSIncrementAtomic(&soextbkidlestat.so_xbkidle_forced);
                }
@@ -6735,14 +7316,17 @@ sosetdefunct(struct proc *p, struct socket *so, int level, boolean_t noforce)
        }
 
 done:
-       SODEFUNCTLOG("%s[%d, %s]: (target pid %d name %s level %d) "
-           "so 0x%llx [%d,%d] %s defunct%s\n", __func__, proc_selfpid(),
-           proc_best_name(current_proc()), proc_pid(p), proc_best_name(p),
-           level, (uint64_t)DEBUG_KERNEL_ADDRPERM(so), SOCK_DOM(so),
-           SOCK_TYPE(so), defunct ? "is already" : "marked as",
-           (so->so_flags1 & SOF1_EXTEND_BK_IDLE_WANTED) ? " extbkidle" : "");
-
-       return (err);
+       if (p != PROC_NULL) {
+               SODEFUNCTLOG("%s[%d, %s]: (target pid %d name %s level %d) "
+                   "so 0x%llx [%d,%d] %s defunct%s\n", __func__,
+                   proc_selfpid(), proc_best_name(current_proc()),
+                   proc_pid(p), proc_best_name(p), level,
+                   (uint64_t)DEBUG_KERNEL_ADDRPERM(so), SOCK_DOM(so),
+                   SOCK_TYPE(so), defunct ? "is already" : "marked as",
+                   (so->so_flags1 & SOF1_EXTEND_BK_IDLE_WANTED) ?
+                   " extbkidle" : "");
+       }
+       return err;
 }
 
 int
@@ -6754,8 +7338,9 @@ sodefunct(struct proc *p, struct socket *so, int level)
                panic("%s improperly called", __func__);
                /* NOTREACHED */
        }
-       if (so->so_state & SS_DEFUNCT)
+       if (so->so_state & SS_DEFUNCT) {
                goto done;
+       }
 
        rcv = &so->so_rcv;
        snd = &so->so_snd;
@@ -6765,23 +7350,29 @@ sodefunct(struct proc *p, struct socket *so, int level)
                char d[MAX_IPv6_STR_LEN];
                struct inpcb *inp = sotoinpcb(so);
 
-               SODEFUNCTLOG("%s[%d, %s]: (target pid %d name %s level %d) "
-                   "so 0x%llx [%s %s:%d -> %s:%d] is now defunct "
-                   "[rcv_si 0x%x, snd_si 0x%x, rcv_fl 0x%x, snd_fl 0x%x]\n",
-                   __func__, proc_selfpid(), proc_best_name(current_proc()),
-                   proc_pid(p), proc_best_name(p), level,
-                   (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
-                   (SOCK_TYPE(so) == SOCK_STREAM) ? "TCP" : "UDP",
-                   inet_ntop(SOCK_DOM(so), ((SOCK_DOM(so) == PF_INET) ?
-                   (void *)&inp->inp_laddr.s_addr : (void *)&inp->in6p_laddr),
-                   s, sizeof (s)), ntohs(inp->in6p_lport),
-                   inet_ntop(SOCK_DOM(so), (SOCK_DOM(so) == PF_INET) ?
-                   (void *)&inp->inp_faddr.s_addr : (void *)&inp->in6p_faddr,
-                   d, sizeof (d)), ntohs(inp->in6p_fport),
-                   (uint32_t)rcv->sb_sel.si_flags,
-                   (uint32_t)snd->sb_sel.si_flags,
-                   rcv->sb_flags, snd->sb_flags);
-       } else {
+               if (p != PROC_NULL) {
+                       SODEFUNCTLOG(
+                               "%s[%d, %s]: (target pid %d name %s level %d) "
+                               "so 0x%llx [%s %s:%d -> %s:%d] is now defunct "
+                               "[rcv_si 0x%x, snd_si 0x%x, rcv_fl 0x%x, "
+                               " snd_fl 0x%x]\n", __func__,
+                               proc_selfpid(), proc_best_name(current_proc()),
+                               proc_pid(p), proc_best_name(p), level,
+                               (uint64_t)DEBUG_KERNEL_ADDRPERM(so),
+                               (SOCK_TYPE(so) == SOCK_STREAM) ? "TCP" : "UDP",
+                               inet_ntop(SOCK_DOM(so), ((SOCK_DOM(so) == PF_INET) ?
+                               (void *)&inp->inp_laddr.s_addr :
+                               (void *)&inp->in6p_laddr),
+                               s, sizeof(s)), ntohs(inp->in6p_lport),
+                               inet_ntop(SOCK_DOM(so), (SOCK_DOM(so) == PF_INET) ?
+                               (void *)&inp->inp_faddr.s_addr :
+                               (void *)&inp->in6p_faddr,
+                               d, sizeof(d)), ntohs(inp->in6p_fport),
+                               (uint32_t)rcv->sb_sel.si_flags,
+                               (uint32_t)snd->sb_sel.si_flags,
+                               rcv->sb_flags, snd->sb_flags);
+               }
+       } else if (p != PROC_NULL) {
                SODEFUNCTLOG("%s[%d, %s]: (target pid %d name %s level %d) "
                    "so 0x%llx [%d,%d] is now defunct [rcv_si 0x%x, "
                    "snd_si 0x%x, rcv_fl 0x%x, snd_fl 0x%x]\n", __func__,
@@ -6801,11 +7392,12 @@ sodefunct(struct proc *p, struct socket *so, int level)
        sbwakeup(snd);
 
        so->so_flags1 |= SOF1_DEFUNCTINPROG;
-       if (rcv->sb_flags & SB_LOCK)
-               sbunlock(rcv, TRUE);    /* keep socket locked */
-       if (snd->sb_flags & SB_LOCK)
-               sbunlock(snd, TRUE);    /* keep socket locked */
-
+       if (rcv->sb_flags & SB_LOCK) {
+               sbunlock(rcv, TRUE);    /* keep socket locked */
+       }
+       if (snd->sb_flags & SB_LOCK) {
+               sbunlock(snd, TRUE);    /* keep socket locked */
+       }
        /*
         * Flush the buffers and disconnect.  We explicitly call shutdown
         * on both data directions to ensure that SS_CANT{RCV,SEND}MORE
@@ -6820,11 +7412,13 @@ sodefunct(struct proc *p, struct socket *so, int level)
         * Explicitly handle connectionless-protocol disconnection
         * and release any remaining data in the socket buffers.
         */
-       if (!(so->so_flags & SS_ISDISCONNECTED))
+       if (!(so->so_state & SS_ISDISCONNECTED)) {
                (void) soisdisconnected(so);
+       }
 
-       if (so->so_error == 0)
+       if (so->so_error == 0) {
                so->so_error = EBADF;
+       }
 
        if (rcv->sb_cc != 0) {
                rcv->sb_flags &= ~SB_SEL;
@@ -6840,14 +7434,15 @@ sodefunct(struct proc *p, struct socket *so, int level)
        OSIncrementAtomicLong((volatile long *)&sodefunct_calls);
 
 done:
-       return (0);
+       return 0;
 }
 
 int
 soresume(struct proc *p, struct socket *so, int locked)
 {
-       if (locked == 0)
+       if (locked == 0) {
                socket_lock(so, 1);
+       }
 
        if (so->so_flags1 & SOF1_EXTEND_BK_IDLE_INPROG) {
                SODEFUNCTLOG("%s[%d, %s]: (target pid %d name %s) so 0x%llx "
@@ -6865,10 +7460,11 @@ soresume(struct proc *p, struct socket *so, int locked)
                OSDecrementAtomic(&soextbkidlestat.so_xbkidle_active);
                VERIFY(soextbkidlestat.so_xbkidle_active >= 0);
        }
-       if (locked == 0)
+       if (locked == 0) {
                socket_unlock(so, 1);
+       }
 
-       return (0);
+       return 0;
 }
 
 /*
@@ -6890,29 +7486,36 @@ so_set_extended_bk_idle(struct socket *so, int optval)
                soresume(current_proc(), so, 1);
        } else {
                struct proc *p = current_proc();
-               int i;
-               struct filedesc *fdp;
+               struct fileproc *fp;
                int count = 0;
 
-               proc_fdlock(p);
+               /*
+                * Unlock socket to avoid lock ordering issue with
+                * the proc fd table lock
+                */
+               socket_unlock(so, 0);
 
-               fdp = p->p_fd;
-               for (i = 0; i < fdp->fd_nfiles; i++) {
-                       struct fileproc *fp = fdp->fd_ofiles[i];
+               proc_fdlock(p);
+               fdt_foreach(fp, p) {
                        struct socket *so2;
 
-                       if (fp == NULL ||
-                           (fdp->fd_ofileflags[i] & UF_RESERVED) != 0 ||
-                           FILEGLOB_DTYPE(fp->f_fglob) != DTYPE_SOCKET)
+                       if (FILEGLOB_DTYPE(fp->fp_glob) != DTYPE_SOCKET) {
                                continue;
+                       }
 
-                       so2 = (struct socket *)fp->f_fglob->fg_data;
+                       so2 = (struct socket *)fp->fp_glob->fg_data;
                        if (so != so2 &&
-                           so2->so_flags1 & SOF1_EXTEND_BK_IDLE_WANTED)
+                           so2->so_flags1 & SOF1_EXTEND_BK_IDLE_WANTED) {
                                count++;
-                       if (count >= soextbkidlestat.so_xbkidle_maxperproc)
+                       }
+                       if (count >= soextbkidlestat.so_xbkidle_maxperproc) {
                                break;
+                       }
                }
+               proc_fdunlock(p);
+
+               socket_lock(so, 0);
+
                if (count >= soextbkidlestat.so_xbkidle_maxperproc) {
                        OSIncrementAtomic(&soextbkidlestat.so_xbkidle_toomany);
                        error = EBUSY;
@@ -6930,11 +7533,9 @@ so_set_extended_bk_idle(struct socket *so, int optval)
                    SOCK_DOM(so), SOCK_TYPE(so),
                    (so->so_flags1 & SOF1_EXTEND_BK_IDLE_WANTED) ?
                    "is" : "not");
-
-               proc_fdunlock(p);
        }
 
-       return (error);
+       return error;
 }
 
 static void
@@ -6999,29 +7600,23 @@ so_check_extended_bk_idle_time(struct socket *so)
                }
        }
 
-       return (ret);
+       return ret;
 }
 
 void
 resume_proc_sockets(proc_t p)
 {
        if (p->p_ladvflag & P_LXBKIDLEINPROG) {
-               struct filedesc *fdp;
-               int i;
+               struct fileproc *fp;
+               struct socket *so;
 
                proc_fdlock(p);
-               fdp = p->p_fd;
-               for (i = 0; i < fdp->fd_nfiles; i++) {
-                       struct fileproc *fp;
-                       struct socket *so;
-
-                       fp = fdp->fd_ofiles[i];
-                       if (fp == NULL ||
-                           (fdp->fd_ofileflags[i] & UF_RESERVED) != 0 ||
-                           FILEGLOB_DTYPE(fp->f_fglob) != DTYPE_SOCKET)
+               fdt_foreach(fp, p) {
+                       if (FILEGLOB_DTYPE(fp->fp_glob) != DTYPE_SOCKET) {
                                continue;
+                       }
 
-                       so = (struct socket *)fp->f_fglob->fg_data;
+                       so = (struct socket *)fp->fp_glob->fg_data;
                        (void) soresume(p, so, 0);
                }
                proc_fdunlock(p);
@@ -7035,18 +7630,16 @@ so_set_recv_anyif(struct socket *so, int optval)
 {
        int ret = 0;
 
-#if INET6
        if (SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6) {
-#else
-       if (SOCK_DOM(so) == PF_INET) {
-#endif /* !INET6 */
-               if (optval)
+               if (optval) {
                        sotoinpcb(so)->inp_flags |= INP_RECV_ANYIF;
-               else
+               } else {
                        sotoinpcb(so)->inp_flags &= ~INP_RECV_ANYIF;
+               }
        }
 
-       return (ret);
+
+       return ret;
 }
 
 __private_extern__ int
@@ -7054,15 +7647,11 @@ so_get_recv_anyif(struct socket *so)
 {
        int ret = 0;
 
-#if INET6
        if (SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6) {
-#else
-       if (SOCK_DOM(so) == PF_INET) {
-#endif /* !INET6 */
                ret = (sotoinpcb(so)->inp_flags & INP_RECV_ANYIF) ? 1 : 0;
        }
 
-       return (ret);
+       return ret;
 }
 
 int
@@ -7070,6 +7659,7 @@ so_set_restrictions(struct socket *so, uint32_t vals)
 {
        int nocell_old, nocell_new;
        int noexpensive_old, noexpensive_new;
+       int noconstrained_old, noconstrained_new;
 
        /*
         * Deny-type restrictions are trapdoors; once set they cannot be
@@ -7086,21 +7676,21 @@ so_set_restrictions(struct socket *so, uint32_t vals)
         */
        nocell_old = (so->so_restrictions & SO_RESTRICT_DENY_CELLULAR);
        noexpensive_old = (so->so_restrictions & SO_RESTRICT_DENY_EXPENSIVE);
+       noconstrained_old = (so->so_restrictions & SO_RESTRICT_DENY_CONSTRAINED);
        so->so_restrictions |= (vals & (SO_RESTRICT_DENY_IN |
            SO_RESTRICT_DENY_OUT | SO_RESTRICT_DENY_CELLULAR |
-           SO_RESTRICT_DENY_EXPENSIVE));
+           SO_RESTRICT_DENY_EXPENSIVE | SO_RESTRICT_DENY_CONSTRAINED));
        nocell_new = (so->so_restrictions & SO_RESTRICT_DENY_CELLULAR);
        noexpensive_new = (so->so_restrictions & SO_RESTRICT_DENY_EXPENSIVE);
+       noconstrained_new = (so->so_restrictions & SO_RESTRICT_DENY_CONSTRAINED);
 
        /* we can only set, not clear restrictions */
        if ((nocell_new - nocell_old) == 0 &&
-           (noexpensive_new - noexpensive_old) == 0)
-               return (0);
-#if INET6
+           (noexpensive_new - noexpensive_old) == 0 &&
+           (noconstrained_new - noconstrained_old) == 0) {
+               return 0;
+       }
        if (SOCK_DOM(so) == PF_INET || SOCK_DOM(so) == PF_INET6) {
-#else
-       if (SOCK_DOM(so) == PF_INET) {
-#endif /* !INET6 */
                if (nocell_new - nocell_old != 0) {
                        /*
                         * if deny cellular is now set, do what's needed
@@ -7111,140 +7701,28 @@ so_set_restrictions(struct socket *so, uint32_t vals)
                if (noexpensive_new - noexpensive_old != 0) {
                        inp_set_noexpensive(sotoinpcb(so));
                }
-       }
-
-       return (0);
-}
-
-uint32_t
-so_get_restrictions(struct socket *so)
-{
-       return (so->so_restrictions & (SO_RESTRICT_DENY_IN |
-           SO_RESTRICT_DENY_OUT |
-           SO_RESTRICT_DENY_CELLULAR | SO_RESTRICT_DENY_EXPENSIVE));
-}
-
-struct sockaddr_entry *
-sockaddrentry_alloc(int how)
-{
-       struct sockaddr_entry *se;
-
-       se = (how == M_WAITOK) ? zalloc(se_zone) : zalloc_noblock(se_zone);
-       if (se != NULL)
-               bzero(se, se_zone_size);
-
-       return (se);
-}
-
-void
-sockaddrentry_free(struct sockaddr_entry *se)
-{
-       if (se->se_addr != NULL) {
-               FREE(se->se_addr, M_SONAME);
-               se->se_addr = NULL;
-       }
-       zfree(se_zone, se);
-}
-
-struct sockaddr_entry *
-sockaddrentry_dup(const struct sockaddr_entry *src_se, int how)
-{
-       struct sockaddr_entry *dst_se;
-
-       dst_se = sockaddrentry_alloc(how);
-       if (dst_se != NULL) {
-               int len = src_se->se_addr->sa_len;
-
-               MALLOC(dst_se->se_addr, struct sockaddr *,
-                   len, M_SONAME, how | M_ZERO);
-               if (dst_se->se_addr != NULL) {
-                       bcopy(src_se->se_addr, dst_se->se_addr, len);
-               } else {
-                       sockaddrentry_free(dst_se);
-                       dst_se = NULL;
+               if (noconstrained_new - noconstrained_old != 0) {
+                       inp_set_noconstrained(sotoinpcb(so));
                }
        }
 
-       return (dst_se);
-}
-
-struct sockaddr_list *
-sockaddrlist_alloc(int how)
-{
-       struct sockaddr_list *sl;
-
-       sl = (how == M_WAITOK) ? zalloc(sl_zone) : zalloc_noblock(sl_zone);
-       if (sl != NULL) {
-               bzero(sl, sl_zone_size);
-               TAILQ_INIT(&sl->sl_head);
-       }
-       return (sl);
-}
-
-void
-sockaddrlist_free(struct sockaddr_list *sl)
-{
-       struct sockaddr_entry *se, *tse;
-
-       TAILQ_FOREACH_SAFE(se, &sl->sl_head, se_link, tse) {
-               sockaddrlist_remove(sl, se);
-               sockaddrentry_free(se);
+       if (SOCK_DOM(so) == PF_MULTIPATH) {
+               mptcp_set_restrictions(so);
        }
-       VERIFY(sl->sl_cnt == 0 && TAILQ_EMPTY(&sl->sl_head));
-       zfree(sl_zone, sl);
-}
-
-void
-sockaddrlist_insert(struct sockaddr_list *sl, struct sockaddr_entry *se)
-{
-       VERIFY(!(se->se_flags & SEF_ATTACHED));
-       se->se_flags |= SEF_ATTACHED;
-       TAILQ_INSERT_TAIL(&sl->sl_head, se, se_link);
-       sl->sl_cnt++;
-       VERIFY(sl->sl_cnt != 0);
-}
 
-void
-sockaddrlist_remove(struct sockaddr_list *sl, struct sockaddr_entry *se)
-{
-       VERIFY(se->se_flags & SEF_ATTACHED);
-       se->se_flags &= ~SEF_ATTACHED;
-       VERIFY(sl->sl_cnt != 0);
-       sl->sl_cnt--;
-       TAILQ_REMOVE(&sl->sl_head, se, se_link);
+       return 0;
 }
 
-struct sockaddr_list *
-sockaddrlist_dup(const struct sockaddr_list *src_sl, int how)
+uint32_t
+so_get_restrictions(struct socket *so)
 {
-       struct sockaddr_entry *src_se, *tse;
-       struct sockaddr_list *dst_sl;
-
-       dst_sl = sockaddrlist_alloc(how);
-       if (dst_sl == NULL)
-               return (NULL);
-
-       TAILQ_FOREACH_SAFE(src_se, &src_sl->sl_head, se_link, tse) {
-               struct sockaddr_entry *dst_se;
-
-               if (src_se->se_addr == NULL)
-                       continue;
-
-               dst_se = sockaddrentry_dup(src_se, how);
-               if (dst_se == NULL) {
-                       sockaddrlist_free(dst_sl);
-                       return (NULL);
-               }
-
-               sockaddrlist_insert(dst_sl, dst_se);
-       }
-       VERIFY(src_sl->sl_cnt == dst_sl->sl_cnt);
-
-       return (dst_sl);
+       return so->so_restrictions & (SO_RESTRICT_DENY_IN |
+              SO_RESTRICT_DENY_OUT |
+              SO_RESTRICT_DENY_CELLULAR | SO_RESTRICT_DENY_EXPENSIVE);
 }
 
 int
-so_set_effective_pid(struct socket *so, int epid, struct proc *p)
+so_set_effective_pid(struct socket *so, int epid, struct proc *p, boolean_t check_cred)
 {
        struct proc *ep = PROC_NULL;
        int error = 0;
@@ -7271,7 +7749,7 @@ so_set_effective_pid(struct socket *so, int epid, struct proc *p)
         * the process's own pid, then proceed.  Otherwise ensure
         * that the issuing process has the necessary privileges.
         */
-       if (epid != so->last_pid || epid != proc_pid(p)) {
+       if (check_cred && (epid != so->last_pid || epid != proc_pid(p))) {
                if ((error = priv_check_cred(kauth_cred_get(),
                    PRIV_NET_PRIVILEGED_SOCKET_DELEGATE, 0))) {
                        error = EACCES;
@@ -7304,7 +7782,24 @@ so_set_effective_pid(struct socket *so, int epid, struct proc *p)
                so->so_flags |= SOF_DELEGATED;
                so->e_upid = proc_uniqueid(ep);
                so->e_pid = proc_pid(ep);
-               proc_getexecutableuuid(ep, so->e_uuid, sizeof (so->e_uuid));
+               proc_getexecutableuuid(ep, so->e_uuid, sizeof(so->e_uuid));
+
+#if defined(XNU_TARGET_OS_OSX)
+               if (ep->p_responsible_pid != so->e_pid) {
+                       proc_t rp = proc_find(ep->p_responsible_pid);
+                       if (rp != PROC_NULL) {
+                               proc_getexecutableuuid(rp, so->so_ruuid, sizeof(so->so_ruuid));
+                               so->so_rpid = ep->p_responsible_pid;
+                               proc_rele(rp);
+                       } else {
+                               uuid_clear(so->so_ruuid);
+                               so->so_rpid = -1;
+                       }
+               }
+#endif
+       }
+       if (so->so_proto != NULL && so->so_proto->pr_update_last_owner != NULL) {
+               (*so->so_proto->pr_update_last_owner)(so, NULL, ep);
        }
 done:
        if (error == 0 && net_io_policy_log) {
@@ -7335,14 +7830,15 @@ done:
 #endif /* NECP */
        }
 
-       if (ep != PROC_NULL)
+       if (ep != PROC_NULL) {
                proc_rele(ep);
+       }
 
-       return (error);
+       return error;
 }
 
 int
-so_set_effective_uuid(struct socket *so, uuid_t euuid, struct proc *p)
+so_set_effective_uuid(struct socket *so, uuid_t euuid, struct proc *p, boolean_t check_cred)
 {
        uuid_string_t buf;
        uuid_t uuid;
@@ -7365,7 +7861,7 @@ so_set_effective_uuid(struct socket *so, uuid_t euuid, struct proc *p)
        }
 
        /* Get the UUID of the issuing process */
-       proc_getexecutableuuid(p, uuid, sizeof (uuid));
+       proc_getexecutableuuid(p, uuid, sizeof(uuid));
 
        /*
         * If this is issued by a process that's recorded as the
@@ -7373,8 +7869,9 @@ so_set_effective_uuid(struct socket *so, uuid_t euuid, struct proc *p)
         * the process's own uuid, then proceed.  Otherwise ensure
         * that the issuing process has the necessary privileges.
         */
-       if (uuid_compare(euuid, so->last_uuid) != 0 ||
-           uuid_compare(euuid, uuid) != 0) {
+       if (check_cred &&
+           (uuid_compare(euuid, so->last_uuid) != 0 ||
+           uuid_compare(euuid, uuid) != 0)) {
                if ((error = priv_check_cred(kauth_cred_get(),
                    PRIV_NET_PRIVILEGED_SOCKET_DELEGATE, 0))) {
                        error = EACCES;
@@ -7409,7 +7906,13 @@ so_set_effective_uuid(struct socket *so, uuid_t euuid, struct proc *p)
                so->e_pid = so->last_pid;
                uuid_copy(so->e_uuid, euuid);
        }
-
+       /*
+        * The following will clear the effective process name as it's the same
+        * as the real process
+        */
+       if (so->so_proto != NULL && so->so_proto->pr_update_last_owner != NULL) {
+               (*so->so_proto->pr_update_last_owner)(so, NULL, NULL);
+       }
 done:
        if (error == 0 && net_io_policy_log) {
                uuid_unparse(so->e_uuid, buf);
@@ -7435,7 +7938,7 @@ done:
 #endif /* NECP */
        }
 
-       return (error);
+       return error;
 }
 
 void
@@ -7449,15 +7952,15 @@ netpolicy_post_msg(uint32_t ev_code, struct netpolicy_event_data *ev_data,
         * structure, but the caller can provide for a longer event
         * structure to post, depending on the event code.
         */
-       VERIFY(ev_data != NULL && ev_datalen >= sizeof (*ev_data));
+       VERIFY(ev_data != NULL && ev_datalen >= sizeof(*ev_data));
 
-       bzero(&ev_msg, sizeof (ev_msg));
-       ev_msg.vendor_code      = KEV_VENDOR_APPLE;
-       ev_msg.kev_class        = KEV_NETWORK_CLASS;
-       ev_msg.kev_subclass     = KEV_NETPOLICY_SUBCLASS;
-       ev_msg.event_code       = ev_code;
+       bzero(&ev_msg, sizeof(ev_msg));
+       ev_msg.vendor_code      = KEV_VENDOR_APPLE;
+       ev_msg.kev_class        = KEV_NETWORK_CLASS;
+       ev_msg.kev_subclass     = KEV_NETPOLICY_SUBCLASS;
+       ev_msg.event_code       = ev_code;
 
-       ev_msg.dv[0].data_ptr   = ev_data;
+       ev_msg.dv[0].data_ptr   = ev_data;
        ev_msg.dv[0].data_length = ev_datalen;
 
        kev_post_msg(&ev_msg);
@@ -7477,7 +7980,7 @@ socket_post_kev_msg(uint32_t ev_code,
        ev_msg.event_code = ev_code;
 
        ev_msg.dv[0].data_ptr = ev_data;
-       ev_msg.dv[0]. data_length = ev_datalen;
+       ev_msg.dv[0].data_length = ev_datalen;
 
        kev_post_msg(&ev_msg);
 }
@@ -7485,10 +7988,13 @@ socket_post_kev_msg(uint32_t ev_code,
 void
 socket_post_kev_msg_closed(struct socket *so)
 {
-       struct kev_socket_closed ev;
+       struct kev_socket_closed ev = {};
        struct sockaddr *socksa = NULL, *peersa = NULL;
        int err;
-       bzero(&ev, sizeof(ev));
+
+       if ((so->so_flags1 & SOF1_WANT_KEV_SOCK_CLOSED) == 0) {
+               return;
+       }
        err = (*so->so_proto->pr_usrreqs->pru_sockaddr)(so, &socksa);
        if (err == 0) {
                err = (*so->so_proto->pr_usrreqs->pru_peeraddr)(so,
@@ -7496,16 +8002,18 @@ socket_post_kev_msg_closed(struct socket *so)
                if (err == 0) {
                        memcpy(&ev.ev_data.kev_sockname, socksa,
                            min(socksa->sa_len,
-                           sizeof (ev.ev_data.kev_sockname)));
+                           sizeof(ev.ev_data.kev_sockname)));
                        memcpy(&ev.ev_data.kev_peername, peersa,
                            min(peersa->sa_len,
-                           sizeof (ev.ev_data.kev_peername)));
+                           sizeof(ev.ev_data.kev_peername)));
                        socket_post_kev_msg(KEV_SOCKET_CLOSED,
-                           &ev.ev_data, sizeof (ev));
+                           &ev.ev_data, sizeof(ev));
                }
        }
-       if (socksa != NULL)
+       if (socksa != NULL) {
                FREE(socksa, M_SONAME);
-       if (peersa != NULL)
+       }
+       if (peersa != NULL) {
                FREE(peersa, M_SONAME);
+       }
 }