]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/netinet/udp_usrreq.c
xnu-3789.51.2.tar.gz
[apple/xnu.git] / bsd / netinet / udp_usrreq.c
index 7e97ffd9a7b5f84797326b1a00899f2ba8a8a139..698aea8b6d4ff4fe4a615f7510d970abd695e023 100644 (file)
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2016 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
@@ -22,7 +22,7 @@
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /*
@@ -58,7 +58,6 @@
  * SUCH DAMAGE.
  *
  *     @(#)udp_usrreq.c        8.6 (Berkeley) 5/23/95
- * $FreeBSD: src/sys/netinet/udp_usrreq.c,v 1.64.2.13 2001/08/08 18:59:54 ghelmer Exp $
  */
 
 #include <sys/param.h>
 #include <sys/socketvar.h>
 #include <sys/sysctl.h>
 #include <sys/syslog.h>
+#include <sys/mcache.h>
+#include <net/ntstat.h>
 
 #include <kern/zalloc.h>
+#include <mach/boolean.h>
 
 #include <net/if.h>
 #include <net/if_types.h>
 #include <net/route.h>
+#include <net/dlil.h>
 
 #include <netinet/in.h>
 #include <netinet/in_systm.h>
+#include <netinet/in_tclass.h>
 #include <netinet/ip.h>
 #if INET6
 #include <netinet/ip6.h>
-#endif
+#endif /* INET6 */
 #include <netinet/in_pcb.h>
 #include <netinet/in_var.h>
 #include <netinet/ip_var.h>
 #if INET6
+#include <netinet6/in6_pcb.h>
 #include <netinet6/ip6_var.h>
-#endif
+#include <netinet6/udp6_var.h>
+#endif /* INET6 */
 #include <netinet/ip_icmp.h>
 #include <netinet/icmp_var.h>
 #include <netinet/udp.h>
 #include <netinet6/ipsec.h>
 #include <netinet6/esp.h>
 extern int ipsec_bypass;
-#endif /*IPSEC*/
+extern int esp_udp_encap_port;
+#endif /* IPSEC */
 
+#if NECP
+#include <net/necp.h>
+#endif /* NECP */
 
-#define DBG_LAYER_IN_BEG       NETDBG_CODE(DBG_NETUDP, 0)
-#define DBG_LAYER_IN_END       NETDBG_CODE(DBG_NETUDP, 2)
-#define DBG_LAYER_OUT_BEG      NETDBG_CODE(DBG_NETUDP, 1)
-#define DBG_LAYER_OUT_END      NETDBG_CODE(DBG_NETUDP, 3)
-#define DBG_FNC_UDP_INPUT      NETDBG_CODE(DBG_NETUDP, (5 << 8))
-#define DBG_FNC_UDP_OUTPUT     NETDBG_CODE(DBG_NETUDP, (6 << 8) | 1)
+#if FLOW_DIVERT
+#include <netinet/flow_divert.h>
+#endif /* FLOW_DIVERT */
+
+#define        DBG_LAYER_IN_BEG        NETDBG_CODE(DBG_NETUDP, 0)
+#define        DBG_LAYER_IN_END        NETDBG_CODE(DBG_NETUDP, 2)
+#define        DBG_LAYER_OUT_BEG       NETDBG_CODE(DBG_NETUDP, 1)
+#define        DBG_LAYER_OUT_END       NETDBG_CODE(DBG_NETUDP, 3)
+#define        DBG_FNC_UDP_INPUT       NETDBG_CODE(DBG_NETUDP, (5 << 8))
+#define        DBG_FNC_UDP_OUTPUT      NETDBG_CODE(DBG_NETUDP, (6 << 8) | 1)
 
 /*
  * UDP protocol implementation.
  * Per RFC 768, August, 1980.
  */
 #ifndef        COMPAT_42
-static int     udpcksum = 1;
+static int udpcksum = 1;
 #else
-static int     udpcksum = 0;           /* XXX */
+static int udpcksum = 0;               /* XXX */
 #endif
-SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
-               &udpcksum, 0, "");
-
-static u_int32_t udps_in_sw_cksum;
-SYSCTL_UINT(_net_inet_udp, OID_AUTO, in_sw_cksum, CTLFLAG_RD,
-    &udps_in_sw_cksum, 0,
-    "Number of received packets checksummed in software");
-
-static u_int64_t udps_in_sw_cksum_bytes;
-SYSCTL_QUAD(_net_inet_udp, OID_AUTO, in_sw_cksum_bytes, CTLFLAG_RD,
-    &udps_in_sw_cksum_bytes,
-    "Amount of received data checksummed in software");
-
-static u_int32_t udps_out_sw_cksum;
-SYSCTL_UINT(_net_inet_udp, OID_AUTO, out_sw_cksum, CTLFLAG_RD,
-    &udps_out_sw_cksum, 0,
-    "Number of transmitted packets checksummed in software");
-
-static u_int64_t udps_out_sw_cksum_bytes;
-SYSCTL_QUAD(_net_inet_udp, OID_AUTO, out_sw_cksum_bytes, CTLFLAG_RD,
-    &udps_out_sw_cksum_bytes,
-    "Amount of transmitted data checksummed in software");
-
-int    log_in_vain = 0;
-SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW, 
-    &log_in_vain, 0, "Log all incoming UDP packets");
-
-static int     blackhole = 0;
-SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW,
+SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum,
+    CTLFLAG_RW | CTLFLAG_LOCKED, &udpcksum, 0, "");
+
+int udp_log_in_vain = 0;
+SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW | CTLFLAG_LOCKED,
+       &udp_log_in_vain, 0, "Log all incoming UDP packets");
+
+static int blackhole = 0;
+SYSCTL_INT(_net_inet_udp, OID_AUTO, blackhole, CTLFLAG_RW | CTLFLAG_LOCKED,
        &blackhole, 0, "Do not send port unreachables for refused connects");
 
-struct inpcbhead udb;          /* from udp_var.h */
+struct inpcbhead udb;          /* from udp_var.h */
 #define        udb6    udb  /* for KAME src sync over BSD*'s */
-struct inpcbinfo udbinfo;
+struct inpcbinfo udbinfo;
 
 #ifndef UDBHASHSIZE
-#define UDBHASHSIZE 16
+#define        UDBHASHSIZE 16
 #endif
 
-extern int     esp_udp_encap_port;
-extern u_long  route_generation;
-
-extern  void    ipfwsyslog( int level, const char *format,...);
-extern int fw_verbose;
-static int udp_gc_done = FALSE; /* Garbage collection performed last slowtimo */
+/* Garbage collection performed during most recent udp_gc() run */
+static boolean_t udp_gc_done = FALSE;
 
 #if IPFIREWALL
-#define log_in_vain_log( a ) {            \
-        if ( (log_in_vain == 3 ) && (fw_verbose == 2)) {        /* Apple logging, log to ipfw.log */ \
-                ipfwsyslog a ;  \
-        }                       \
-        else log a ;            \
+extern int fw_verbose;
+extern void ipfwsyslog(int level, const char *format, ...);
+extern void ipfw_stealth_stats_incr_udp(void);
+
+/* Apple logging, log to ipfw.log */
+#define        log_in_vain_log(a) {                                            \
+       if ((udp_log_in_vain == 3) && (fw_verbose == 2)) {              \
+               ipfwsyslog a;                                           \
+       } else if ((udp_log_in_vain == 4) && (fw_verbose == 2)) {       \
+               ipfw_stealth_stats_incr_udp();                          \
+       } else {                                                        \
+               log a;                                                  \
+       }                                                               \
 }
-#else
-#define log_in_vain_log( a ) { log a; }
-#endif
+#else /* !IPFIREWALL */
+#define        log_in_vain_log(a) { log a; }
+#endif /* !IPFIREWALL */
 
+static int udp_getstat SYSCTL_HANDLER_ARGS;
 struct udpstat udpstat;        /* from udp_var.h */
-SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RD,
-    &udpstat, udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
-SYSCTL_INT(_net_inet_udp, OID_AUTO, pcbcount, CTLFLAG_RD, 
-    &udbinfo.ipi_count, 0, "Number of active PCBs");
+SYSCTL_PROC(_net_inet_udp, UDPCTL_STATS, stats,
+       CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
+       0, 0, udp_getstat, "S,udpstat",
+       "UDP statistics (struct udpstat, netinet/udp_var.h)");
+
+SYSCTL_INT(_net_inet_udp, OID_AUTO, pcbcount,
+       CTLFLAG_RD | CTLFLAG_LOCKED, &udbinfo.ipi_count, 0,
+       "Number of active PCBs");
+
+__private_extern__ int udp_use_randomport = 1;
+SYSCTL_INT(_net_inet_udp, OID_AUTO, randomize_ports,
+       CTLFLAG_RW | CTLFLAG_LOCKED, &udp_use_randomport, 0,
+       "Randomize UDP port numbers");
 
 #if INET6
 struct udp_in6 {
@@ -193,112 +200,129 @@ struct udp_ip6 {
        struct ip6_hdr          uip6_ip6;
        u_char                  uip6_init_done : 1;
 };
+
+static int udp_abort(struct socket *);
+static int udp_attach(struct socket *, int, struct proc *);
+static int udp_bind(struct socket *, struct sockaddr *, struct proc *);
+static int udp_connect(struct socket *, struct sockaddr *, struct proc *);
+static int udp_connectx(struct socket *, struct sockaddr *,
+    struct sockaddr *, struct proc *, uint32_t, sae_associd_t,
+    sae_connid_t *, uint32_t, void *, uint32_t, struct uio *, user_ssize_t *);
+static int udp_detach(struct socket *);
+static int udp_disconnect(struct socket *);
+static int udp_disconnectx(struct socket *, sae_associd_t, sae_connid_t);
+static int udp_send(struct socket *, int, struct mbuf *, struct sockaddr *,
+    struct mbuf *, struct proc *);
+static void udp_append(struct inpcb *, struct ip *, struct mbuf *, int,
+    struct sockaddr_in *, struct udp_in6 *, struct udp_ip6 *, struct ifnet *);
+#else /* !INET6 */
+static void udp_append(struct inpcb *, struct ip *, struct mbuf *, int,
+    struct sockaddr_in *, struct ifnet *);
+#endif /* !INET6 */
+static int udp_input_checksum(struct mbuf *, struct udphdr *, int, int);
+static int udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
+    struct mbuf *, struct proc *);
 static void ip_2_ip6_hdr(struct ip6_hdr *ip6, struct ip *ip);
-static void udp_append(struct inpcb *last, struct ip *ip,
-    struct mbuf *n, int off, struct sockaddr_in *pudp_in,
-    struct udp_in6 *pudp_in6, struct udp_ip6 *pudp_ip6);
-#else
-static void udp_append(struct inpcb *last, struct ip *ip,
-    struct mbuf *n, int off, struct sockaddr_in *pudp_in);
-#endif
+static void udp_gc(struct inpcbinfo *);
 
-static int udp_detach(struct socket *so);
-static int udp_output(struct inpcb *, struct mbuf *, struct sockaddr *,
-                           struct mbuf *, struct proc *);
-extern int ChkAddressOK( __uint32_t dstaddr, __uint32_t srcaddr );
+struct pr_usrreqs udp_usrreqs = {
+       .pru_abort =            udp_abort,
+       .pru_attach =           udp_attach,
+       .pru_bind =             udp_bind,
+       .pru_connect =          udp_connect,
+       .pru_connectx =         udp_connectx,
+       .pru_control =          in_control,
+       .pru_detach =           udp_detach,
+       .pru_disconnect =       udp_disconnect,
+       .pru_disconnectx =      udp_disconnectx,
+       .pru_peeraddr =         in_getpeeraddr,
+       .pru_send =             udp_send,
+       .pru_shutdown =         udp_shutdown,
+       .pru_sockaddr =         in_getsockaddr,
+       .pru_sosend =           sosend,
+       .pru_soreceive =        soreceive,
+       .pru_soreceive_list =   soreceive_list,
+};
 
 void
-udp_init()
+udp_init(struct protosw *pp, struct domain *dp)
 {
-       vm_size_t                       str_size;
-       struct inpcbinfo        *pcbinfo;
-       
+#pragma unused(dp)
+       static int udp_initialized = 0;
+       vm_size_t               str_size;
+       struct inpcbinfo        *pcbinfo;
+
+       VERIFY((pp->pr_flags & (PR_INITIALIZED|PR_ATTACHED)) == PR_ATTACHED);
+
+       if (udp_initialized)
+               return;
+       udp_initialized = 1;
 
        LIST_INIT(&udb);
-       udbinfo.listhead = &udb;
-       udbinfo.hashbase = hashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashmask);
-       udbinfo.porthashbase = hashinit(UDBHASHSIZE, M_PCB,
-                                       &udbinfo.porthashmask);
-#ifdef __APPLE__
-       str_size = (vm_size_t) sizeof(struct inpcb);
-       udbinfo.ipi_zone = (void *) zinit(str_size, 80000*str_size, 8192, "udpcb");
-
-       pcbinfo = &udbinfo;
+       udbinfo.ipi_listhead = &udb;
+       udbinfo.ipi_hashbase = hashinit(UDBHASHSIZE, M_PCB,
+           &udbinfo.ipi_hashmask);
+       udbinfo.ipi_porthashbase = hashinit(UDBHASHSIZE, M_PCB,
+           &udbinfo.ipi_porthashmask);
+       str_size = (vm_size_t) sizeof (struct inpcb);
+       udbinfo.ipi_zone = zinit(str_size, 80000*str_size, 8192, "udpcb");
+
+       pcbinfo = &udbinfo;
        /*
         * allocate lock group attribute and group for udp pcb mutexes
         */
-       pcbinfo->mtx_grp_attr = lck_grp_attr_alloc_init();
-
-       pcbinfo->mtx_grp = lck_grp_alloc_init("udppcb", pcbinfo->mtx_grp_attr);
-               
-       pcbinfo->mtx_attr = lck_attr_alloc_init();
-
-       if ((pcbinfo->mtx = lck_rw_alloc_init(pcbinfo->mtx_grp, pcbinfo->mtx_attr)) == NULL)
-               return; /* pretty much dead if this fails... */
-
-       in_pcb_nat_init(&udbinfo, AF_INET, IPPROTO_UDP, SOCK_DGRAM);
-#else
-       udbinfo.ipi_zone = zinit("udpcb", sizeof(struct inpcb), maxsockets,
-                                ZONE_INTERRUPT, 0);
-#endif
+       pcbinfo->ipi_lock_grp_attr = lck_grp_attr_alloc_init();
+       pcbinfo->ipi_lock_grp = lck_grp_alloc_init("udppcb",
+           pcbinfo->ipi_lock_grp_attr);
+       pcbinfo->ipi_lock_attr = lck_attr_alloc_init();
+       if ((pcbinfo->ipi_lock = lck_rw_alloc_init(pcbinfo->ipi_lock_grp,
+           pcbinfo->ipi_lock_attr)) == NULL) {
+               panic("%s: unable to allocate PCB lock\n", __func__);
+               /* NOTREACHED */
+       }
 
-#if 0
-       /* for pcb sharing testing only */
-       stat = in_pcb_new_share_client(&udbinfo, &fake_owner);
-       kprintf("udp_init in_pcb_new_share_client - stat = %d\n", stat);
-
-       laddr.s_addr = 0x11646464;
-       faddr.s_addr = 0x11646465;
-       
-       lport = 1500;
-       in_pcb_grab_port(&udbinfo, 0, laddr, &lport, faddr, 1600, 0, fake_owner); 
-       kprintf("udp_init in_pcb_grab_port - stat = %d\n", stat);
-
-       stat = in_pcb_rem_share_client(&udbinfo, fake_owner);
-       kprintf("udp_init in_pcb_rem_share_client - stat = %d\n", stat);
-
-       stat = in_pcb_new_share_client(&udbinfo, &fake_owner);
-       kprintf("udp_init in_pcb_new_share_client(2) - stat = %d\n", stat);
-
-       laddr.s_addr = 0x11646464;
-       faddr.s_addr = 0x11646465;
-       
-       lport = 1500;
-       stat = in_pcb_grab_port(&udbinfo, 0, laddr, &lport, faddr, 1600, 0, fake_owner); 
-       kprintf("udp_init in_pcb_grab_port(2) - stat = %d\n", stat);
-#endif
+       udbinfo.ipi_gc = udp_gc;
+       in_pcbinfo_attach(&udbinfo);
 }
 
 void
-udp_input(m, iphlen)
-       register struct mbuf *m;
-       int iphlen;
+udp_input(struct mbuf *m, int iphlen)
 {
-       register struct ip *ip;
-       register struct udphdr *uh;
-       register struct inpcb *inp;
-       struct mbuf *opts = 0;
-       int len;
+       struct ip *ip;
+       struct udphdr *uh;
+       struct inpcb *inp;
+       struct mbuf *opts = NULL;
+       int len, isbroadcast;
        struct ip save_ip;
        struct sockaddr *append_sa;
        struct inpcbinfo *pcbinfo = &udbinfo;
-       struct sockaddr_in udp_in = {
-               sizeof (udp_in), AF_INET, 0, { 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 }
-       };
+       struct sockaddr_in udp_in;
+       struct ip_moptions *imo = NULL;
+       int foundmembership = 0, ret = 0;
 #if INET6
-       struct udp_in6 udp_in6 = {
-               { sizeof (udp_in6.uin6_sin), AF_INET6, 0, 0,
-                   IN6ADDR_ANY_INIT, 0 },
-               0
-       };
+       struct udp_in6 udp_in6;
        struct udp_ip6 udp_ip6;
 #endif /* INET6 */
+       struct ifnet *ifp = m->m_pkthdr.rcvif;
+       boolean_t cell = IFNET_IS_CELLULAR(ifp);
+       boolean_t wifi = (!cell && IFNET_IS_WIFI(ifp));
+       boolean_t wired = (!wifi && IFNET_IS_WIRED(ifp));
+
+       bzero(&udp_in, sizeof (udp_in));
+       udp_in.sin_len = sizeof (struct sockaddr_in);
+       udp_in.sin_family = AF_INET;
+#if INET6
+       bzero(&udp_in6, sizeof (udp_in6));
+       udp_in6.uin6_sin.sin6_len = sizeof (struct sockaddr_in6);
+       udp_in6.uin6_sin.sin6_family = AF_INET6;
+#endif /* INET6 */
 
        udpstat.udps_ipackets++;
 
-       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_START, 0,0,0,0,0);
-       if (m->m_pkthdr.csum_flags & CSUM_TCP_SUM16)
-               m->m_pkthdr.csum_flags = 0; /* invalidate hwcksum for UDP */
+       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_START, 0, 0, 0, 0, 0);
+
+       /* Expect 32-bit aligned data pointer on strict-align platforms */
+       MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
 
        /*
         * Strip IP options, if any; should skip this,
@@ -308,29 +332,33 @@ udp_input(m, iphlen)
         */
        if (iphlen > sizeof (struct ip)) {
                ip_stripoptions(m, (struct mbuf *)0);
-               iphlen = sizeof(struct ip);
+               iphlen = sizeof (struct ip);
        }
 
        /*
         * Get IP and UDP header together in first mbuf.
         */
        ip = mtod(m, struct ip *);
-       if (m->m_len < iphlen + sizeof(struct udphdr)) {
-               if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
+       if (m->m_len < iphlen + sizeof (struct udphdr)) {
+               m = m_pullup(m, iphlen + sizeof (struct udphdr));
+               if (m == NULL) {
                        udpstat.udps_hdrops++;
-                       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0,0,0,0,0);
+                       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END,
+                           0, 0, 0, 0, 0);
                        return;
                }
                ip = mtod(m, struct ip *);
        }
-       uh = (struct udphdr *)((caddr_t)ip + iphlen);
+       uh = (struct udphdr *)(void *)((caddr_t)ip + iphlen);
 
        /* destination port of 0 is illegal, based on RFC768. */
-       if (uh->uh_dport == 0)
+       if (uh->uh_dport == 0) {
+               IF_UDP_STATINC(ifp, port0);
                goto bad;
+       }
 
        KERNEL_DEBUG(DBG_LAYER_IN_BEG, uh->uh_dport, uh->uh_sport,
-                    ip->ip_src.s_addr, ip->ip_dst.s_addr, uh->uh_ulen);
+           ip->ip_src.s_addr, ip->ip_dst.s_addr, uh->uh_ulen);
 
        /*
         * Make mbuf data length reflect UDP length.
@@ -338,8 +366,9 @@ udp_input(m, iphlen)
         */
        len = ntohs((u_short)uh->uh_ulen);
        if (ip->ip_len != len) {
-               if (len > ip->ip_len || len < sizeof(struct udphdr)) {
+               if (len > ip->ip_len || len < sizeof (struct udphdr)) {
                        udpstat.udps_badlen++;
+                       IF_UDP_STATINC(ifp, badlength);
                        goto bad;
                }
                m_adj(m, len - ip->ip_len);
@@ -354,48 +383,15 @@ udp_input(m, iphlen)
        /*
         * Checksum extended UDP header and data.
         */
-       if (uh->uh_sum) {
-               if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
-                       if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR)
-                               uh->uh_sum = m->m_pkthdr.csum_data;
-                       else
-                               goto doudpcksum;
-                       uh->uh_sum ^= 0xffff;
-               } else {
-                       char b[9];
-doudpcksum:
-                       *(uint32_t*)&b[0] = *(uint32_t*)&((struct ipovly *)ip)->ih_x1[0];
-                       *(uint32_t*)&b[4] = *(uint32_t*)&((struct ipovly *)ip)->ih_x1[4];
-                       *(uint8_t*)&b[8] = *(uint8_t*)&((struct ipovly *)ip)->ih_x1[8];
-                       
-                       bzero(((struct ipovly *)ip)->ih_x1, 9);
-                       ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
-                       uh->uh_sum = in_cksum(m, len + sizeof (struct ip));
-                       
-                       *(uint32_t*)&((struct ipovly *)ip)->ih_x1[0] = *(uint32_t*)&b[0];
-                       *(uint32_t*)&((struct ipovly *)ip)->ih_x1[4] = *(uint32_t*)&b[4];
-                       *(uint8_t*)&((struct ipovly *)ip)->ih_x1[8] = *(uint8_t*)&b[8];
-                       udp_in_cksum_stats(len);
-               }
-               if (uh->uh_sum) {
-                       udpstat.udps_badsum++;
-                       m_freem(m);
-                       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0,0,0,0,0);
-                       return;
-               }
-       }
-#ifndef __APPLE__
-        else
-               udpstat.udps_nosum++;
-#endif
+       if (udp_input_checksum(m, uh, iphlen, len))
+               goto bad;
 
-       if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
-           in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
+       isbroadcast = in_broadcast(ip->ip_dst, ifp);
 
+       if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) || isbroadcast) {
                int reuse_sock = 0, mcast_delivered = 0;
-               struct mbuf *n = NULL;
 
-               lck_rw_lock_shared(pcbinfo->mtx);
+               lck_rw_lock_shared(pcbinfo->ipi_lock);
                /*
                 * Deliver a multicast or broadcast datagram to *all* sockets
                 * for which the local and remote addresses and ports match
@@ -412,7 +408,6 @@ doudpcksum:
                 * fixing the interface.  Maybe 4.5BSD will remedy this?)
                 */
 
-
                /*
                 * Construct sockaddr format source address.
                 */
@@ -424,29 +419,39 @@ doudpcksum:
                 */
 #if INET6
                udp_in6.uin6_init_done = udp_ip6.uip6_init_done = 0;
-#endif
+#endif /* INET6 */
                LIST_FOREACH(inp, &udb, inp_list) {
-#ifdef __APPLE__
-                       /* Ignore nat/SharedIP dummy pcbs */
-                       if (inp->inp_socket == &udbinfo.nat_dummy_socket)
-                               continue;
-#endif
-                       if (inp->inp_socket == NULL) 
+#if IPSEC
+                       int skipit;
+#endif /* IPSEC */
+
+                       if (inp->inp_socket == NULL)
                                continue;
-                       if (inp != sotoinpcb(inp->inp_socket))
-                               panic("udp_input: bad so back ptr inp=%p\n", inp);
+                       if (inp != sotoinpcb(inp->inp_socket)) {
+                               panic("%s: bad so back ptr inp=%p\n",
+                                   __func__, inp);
+                               /* NOTREACHED */
+                       }
 #if INET6
-                        if ((inp->inp_vflag & INP_IPV4) == 0)
-                                continue;
-#endif
+                       if ((inp->inp_vflag & INP_IPV4) == 0)
+                               continue;
+#endif /* INET6 */
+                       if (inp_restricted_recv(inp, ifp))
+                               continue;
 
-                       if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING) {
+                       if ((inp->inp_moptions == NULL) &&
+                           (ntohl(ip->ip_dst.s_addr) !=
+                           INADDR_ALLHOSTS_GROUP) && (isbroadcast == 0))
                                continue;
-                       }
-                       
-                       udp_lock(inp->inp_socket, 1, 0);        
 
-                       if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) {
+                       if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) ==
+                           WNT_STOPUSING)
+                               continue;
+
+                       udp_lock(inp->inp_socket, 1, 0);
+
+                       if (in_pcb_checkstate(inp, WNT_RELEASE, 1) ==
+                           WNT_STOPUSING) {
                                udp_unlock(inp->inp_socket, 1, 0);
                                continue;
                        }
@@ -471,36 +476,72 @@ doudpcksum:
                                }
                        }
 
-                       reuse_sock = inp->inp_socket->so_options& (SO_REUSEPORT|SO_REUSEADDR);
-                       {
-#if IPSEC
-                               int skipit = 0;
-                               /* check AH/ESP integrity. */
-                               if (ipsec_bypass == 0) {
-                                       if (ipsec4_in_reject_so(m, inp->inp_socket)) {
-                                               IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
-                                               /* do not inject data to pcb */
-                                               skipit = 1;
-                                       }
+                       if (isbroadcast == 0 && (ntohl(ip->ip_dst.s_addr) !=
+                           INADDR_ALLHOSTS_GROUP)) {
+                               struct sockaddr_in group;
+                               int blocked;
+
+                               if ((imo = inp->inp_moptions) == NULL) {
+                                       udp_unlock(inp->inp_socket, 1, 0);
+                                       continue;
                                }
-                               if (skipit == 0) 
-#endif /*IPSEC*/
-                               {
-                                       if (reuse_sock) 
-                                               n = m_copy(m, 0, M_COPYALL);
-#if INET6
-                                       udp_append(inp, ip, m,
-                                           iphlen + sizeof(struct udphdr),
-                                           &udp_in, &udp_in6, &udp_ip6);
-#else
-                                       udp_append(inp, ip, m,
-                                           iphlen + sizeof(struct udphdr),
-                                           &udp_in);
-#endif /* INET6 */
-                                       mcast_delivered++;
+                               IMO_LOCK(imo);
+
+                               bzero(&group, sizeof (struct sockaddr_in));
+                               group.sin_len = sizeof (struct sockaddr_in);
+                               group.sin_family = AF_INET;
+                               group.sin_addr = ip->ip_dst;
+
+                               blocked = imo_multi_filter(imo, ifp,
+                                   (struct sockaddr *)&group,
+                                   (struct sockaddr *)&udp_in);
+                               if (blocked == MCAST_PASS)
+                                       foundmembership = 1;
+
+                               IMO_UNLOCK(imo);
+                               if (!foundmembership) {
+                                       udp_unlock(inp->inp_socket, 1, 0);
+                                       if (blocked == MCAST_NOTSMEMBER ||
+                                           blocked == MCAST_MUTED)
+                                               udpstat.udps_filtermcast++;
+                                       continue;
                                }
-                               udp_unlock(inp->inp_socket, 1, 0);
+                               foundmembership = 0;
+                       }
+
+                       reuse_sock = (inp->inp_socket->so_options &
+                           (SO_REUSEPORT|SO_REUSEADDR));
+
+#if NECP
+                       skipit = 0;
+                       if (!necp_socket_is_allowed_to_send_recv_v4(inp,
+                           uh->uh_dport, uh->uh_sport, &ip->ip_dst,
+                           &ip->ip_src, ifp, NULL, NULL)) {
+                               /* do not inject data to pcb */
+                               skipit = 1;
+                       }
+                       if (skipit == 0)
+#endif /* NECP */
+                       {
+                               struct mbuf *n = NULL;
+
+                               if (reuse_sock)
+                                       n = m_copy(m, 0, M_COPYALL);
+#if INET6
+                               udp_append(inp, ip, m,
+                                   iphlen + sizeof (struct udphdr),
+                                   &udp_in, &udp_in6, &udp_ip6, ifp);
+#else /* !INET6 */
+                               udp_append(inp, ip, m,
+                                   iphlen + sizeof (struct udphdr),
+                                   &udp_in, ifp);
+#endif /* !INET6 */
+                               mcast_delivered++;
+
+                               m = n;
                        }
+                       udp_unlock(inp->inp_socket, 1, 0);
+
                        /*
                         * Don't look for additional matches if this one does
                         * not have either the SO_REUSEPORT or SO_REUSEADDR
@@ -509,10 +550,21 @@ doudpcksum:
                         * port.  It assumes that an application will never
                         * clear these options after setting them.
                         */
-                       if (reuse_sock == 0 || ((m = n) == NULL))
+                       if (reuse_sock == 0 || m == NULL)
                                break;
+
+                       /*
+                        * Expect 32-bit aligned data pointer on strict-align
+                        * platforms.
+                        */
+                       MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
+                       /*
+                        * Recompute IP and UDP header pointers for new mbuf
+                        */
+                       ip = mtod(m, struct ip *);
+                       uh = (struct udphdr *)(void *)((caddr_t)ip + iphlen);
                }
-               lck_rw_done(pcbinfo->mtx);
+               lck_rw_done(pcbinfo->ipi_lock);
 
                if (mcast_delivered == 0) {
                        /*
@@ -521,11 +573,14 @@ doudpcksum:
                         * for a broadcast or multicast datgram.)
                         */
                        udpstat.udps_noportbcast++;
+                       IF_UDP_STATINC(ifp, port_unreach);
                        goto bad;
                }
 
-               if (reuse_sock != 0)    /* free the extra copy of mbuf */
+               /* free the extra copy of mbuf or skipped by IPSec */
+               if (m != NULL)
                        m_freem(m);
+               KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0, 0, 0, 0, 0);
                return;
        }
 
@@ -538,71 +593,76 @@ doudpcksum:
         * or discard the NAT keep-alive.
         */
        if (ipsec_bypass == 0 && (esp_udp_encap_port & 0xFFFF) != 0 &&
-               uh->uh_dport == ntohs((u_short)esp_udp_encap_port)) {
-               int     payload_len = len - sizeof(struct udphdr) > 4 ? 4 : len - sizeof(struct udphdr);
-               if (m->m_len < iphlen + sizeof(struct udphdr) + payload_len) {
-                       if ((m = m_pullup(m, iphlen + sizeof(struct udphdr) + payload_len)) == 0) {
+           uh->uh_dport == ntohs((u_short)esp_udp_encap_port)) {
+               int payload_len = len - sizeof (struct udphdr) > 4 ? 4 :
+                   len - sizeof (struct udphdr);
+
+               if (m->m_len < iphlen + sizeof (struct udphdr) + payload_len) {
+                       if ((m = m_pullup(m, iphlen + sizeof (struct udphdr) +
+                           payload_len)) == NULL) {
                                udpstat.udps_hdrops++;
-                               KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0,0,0,0,0);
+                               KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END,
+                                   0, 0, 0, 0, 0);
                                return;
                        }
+                       /*
+                        * Expect 32-bit aligned data pointer on strict-align
+                        * platforms.
+                        */
+                       MBUF_STRICT_DATA_ALIGNMENT_CHECK_32(m);
+
                        ip = mtod(m, struct ip *);
-                       uh = (struct udphdr *)((caddr_t)ip + iphlen);
+                       uh = (struct udphdr *)(void *)((caddr_t)ip + iphlen);
                }
                /* Check for NAT keepalive packet */
-               if (payload_len == 1 && *(u_int8_t*)((caddr_t)uh + sizeof(struct udphdr)) == 0xFF) {
+               if (payload_len == 1 && *(u_int8_t *)
+                   ((caddr_t)uh + sizeof (struct udphdr)) == 0xFF) {
                        m_freem(m);
-                       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0,0,0,0,0);
+                       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END,
+                           0, 0, 0, 0, 0);
                        return;
-               }
-               else if (payload_len == 4 && *(u_int32_t*)((caddr_t)uh + sizeof(struct udphdr)) != 0) {
+               } else if (payload_len == 4 && *(u_int32_t *)(void *)
+                   ((caddr_t)uh + sizeof (struct udphdr)) != 0) {
                        /* UDP encapsulated IPSec packet to pass through NAT */
-                       size_t stripsiz;
-
-                       stripsiz = sizeof(struct udphdr);
-
-                       ip = mtod(m, struct ip *);
-                       ovbcopy((caddr_t)ip, (caddr_t)(((u_char *)ip) + stripsiz), iphlen);
-                       m->m_data += stripsiz;
-                       m->m_len -= stripsiz;
-                       m->m_pkthdr.len -= stripsiz;
-                       ip = mtod(m, struct ip *);
-                       ip->ip_len = ip->ip_len - stripsiz;
-                       ip->ip_p = IPPROTO_ESP;
-
-                       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0,0,0,0,0);
-                       esp4_input(m, iphlen);
+                       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END,
+                           0, 0, 0, 0, 0);
+                       /* preserve the udp header */
+                       esp4_input(m, iphlen + sizeof (struct udphdr));
                        return;
                }
        }
-#endif
+#endif /* IPSEC */
 
        /*
         * Locate pcb for datagram.
         */
        inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport,
-           ip->ip_dst, uh->uh_dport, 1, m->m_pkthdr.rcvif);
+           ip->ip_dst, uh->uh_dport, 1, ifp);
        if (inp == NULL) {
-               if (log_in_vain) {
+               IF_UDP_STATINC(ifp, port_unreach);
+
+               if (udp_log_in_vain) {
                        char buf[MAX_IPv4_STR_LEN];
                        char buf2[MAX_IPv4_STR_LEN];
 
                        /* check src and dst address */
-                       if (log_in_vain != 3)
-                               log(LOG_INFO,
-                                       "Connection attempt to UDP %s:%d from %s:%d\n",
-                                       inet_ntop(AF_INET, &ip->ip_dst, buf, sizeof(buf)),
-                                       ntohs(uh->uh_dport),
-                                       inet_ntop(AF_INET, &ip->ip_src, buf2, sizeof(buf2)),
+                       if (udp_log_in_vain < 3) {
+                               log(LOG_INFO, "Connection attempt to "
+                                   "UDP %s:%d from %s:%d\n", inet_ntop(AF_INET,
+                                       &ip->ip_dst, buf, sizeof (buf)),
+                                       ntohs(uh->uh_dport), inet_ntop(AF_INET,
+                                       &ip->ip_src, buf2, sizeof (buf2)),
                                        ntohs(uh->uh_sport));
-                       else if (!(m->m_flags & (M_BCAST | M_MCAST)) &&
-                                        ip->ip_dst.s_addr != ip->ip_src.s_addr)
+                       else if (!(m->m_flags & (M_BCAST | M_MCAST)) &&
+                           ip->ip_dst.s_addr != ip->ip_src.s_addr) {
                                log_in_vain_log((LOG_INFO,
-                                       "Stealth Mode connection attempt to UDP %s:%d from %s:%d\n",
-                                       inet_ntop(AF_INET, &ip->ip_dst, buf, sizeof(buf)),
-                                       ntohs(uh->uh_dport),
-                                       inet_ntop(AF_INET, &ip->ip_src, buf2, sizeof(buf2)),
-                                       ntohs(uh->uh_sport)))
+                                   "Stealth Mode connection attempt to "
+                                   "UDP %s:%d from %s:%d\n", inet_ntop(AF_INET,
+                                   &ip->ip_dst, buf, sizeof (buf)),
+                                   ntohs(uh->uh_dport), inet_ntop(AF_INET,
+                                   &ip->ip_src, buf2, sizeof (buf2)),
+                                   ntohs(uh->uh_sport)))
+                       }
                }
                udpstat.udps_noport++;
                if (m->m_flags & (M_BCAST | M_MCAST)) {
@@ -612,31 +672,31 @@ doudpcksum:
 #if ICMP_BANDLIM
                if (badport_bandlim(BANDLIM_ICMP_UNREACH) < 0)
                        goto bad;
-#endif
+#endif /* ICMP_BANDLIM */
                if (blackhole)
-                       if (m->m_pkthdr.rcvif && m->m_pkthdr.rcvif->if_type != IFT_LOOP)
+                       if (ifp && ifp->if_type != IFT_LOOP)
                                goto bad;
                *ip = save_ip;
                ip->ip_len += iphlen;
                icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
-               KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0,0,0,0,0);
+               KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0, 0, 0, 0, 0);
                return;
        }
        udp_lock(inp->inp_socket, 1, 0);
 
        if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) {
                udp_unlock(inp->inp_socket, 1, 0);
+               IF_UDP_STATINC(ifp, cleanup);
                goto bad;
        }
-#if IPSEC
-       if (ipsec_bypass == 0 && inp != NULL) {
-               if (ipsec4_in_reject_so(m, inp->inp_socket)) {
-                       IPSEC_STAT_INCREMENT(ipsecstat.in_polvio);
-                       udp_unlock(inp->inp_socket, 1, 0);
-                       goto bad;
-               }
+#if NECP
+       if (!necp_socket_is_allowed_to_send_recv_v4(inp, uh->uh_dport,
+           uh->uh_sport, &ip->ip_dst, &ip->ip_src, ifp, NULL, NULL)) {
+               udp_unlock(inp->inp_socket, 1, 0);
+               IF_UDP_STATINC(ifp, badipsec);
+               goto bad;
        }
-#endif /*IPSEC*/
+#endif /* NECP */
 
        /*
         * Construct sockaddr format source address.
@@ -644,8 +704,9 @@ doudpcksum:
         */
        udp_in.sin_port = uh->uh_sport;
        udp_in.sin_addr = ip->ip_src;
-       if (inp->inp_flags & INP_CONTROLOPTS
-           || inp->inp_socket->so_options & SO_TIMESTAMP) {
+       if ((inp->inp_flags & INP_CONTROLOPTS) != 0 ||
+           (inp->inp_socket->so_options & SO_TIMESTAMP) != 0 ||
+           (inp->inp_socket->so_options & SO_TIMESTAMP_MONOTONIC) != 0) {
 #if INET6
                if (inp->inp_vflag & INP_IPV6) {
                        int savedflags;
@@ -653,59 +714,73 @@ doudpcksum:
                        ip_2_ip6_hdr(&udp_ip6.uip6_ip6, ip);
                        savedflags = inp->inp_flags;
                        inp->inp_flags &= ~INP_UNMAPPABLEOPTS;
-                       ip6_savecontrol(inp, &opts, &udp_ip6.uip6_ip6, m);
+                       ret = ip6_savecontrol(inp, m, &opts);
                        inp->inp_flags = savedflags;
                } else
-#endif
-               ip_savecontrol(inp, &opts, ip, m);
+#endif /* INET6 */
+               {
+                       ret = ip_savecontrol(inp, &opts, ip, m);
+               }
+               if (ret != 0) {
+                       udp_unlock(inp->inp_socket, 1, 0);
+                       goto bad;
+               }
        }
-       m_adj(m, iphlen + sizeof(struct udphdr));
+       m_adj(m, iphlen + sizeof (struct udphdr));
 
        KERNEL_DEBUG(DBG_LAYER_IN_END, uh->uh_dport, uh->uh_sport,
-                    save_ip.ip_src.s_addr, save_ip.ip_dst.s_addr, uh->uh_ulen);
+           save_ip.ip_src.s_addr, save_ip.ip_dst.s_addr, uh->uh_ulen);
 
 #if INET6
        if (inp->inp_vflag & INP_IPV6) {
                in6_sin_2_v4mapsin6(&udp_in, &udp_in6.uin6_sin);
                append_sa = (struct sockaddr *)&udp_in6.uin6_sin;
        } else
-#endif
-       append_sa = (struct sockaddr *)&udp_in;
-       if (sbappendaddr(&inp->inp_socket->so_rcv, append_sa, m, opts, NULL) == 0) {
-               udpstat.udps_fullsock++;
+#endif /* INET6 */
+       {
+               append_sa = (struct sockaddr *)&udp_in;
+       }
+       if (nstat_collect) {
+               INP_ADD_STAT(inp, cell, wifi, wired, rxpackets, 1);
+               INP_ADD_STAT(inp, cell, wifi, wired, rxbytes, m->m_pkthdr.len);
        }
-       else {
+       so_recv_data_stat(inp->inp_socket, m, 0);
+       if (sbappendaddr(&inp->inp_socket->so_rcv, append_sa,
+           m, opts, NULL) == 0) {
+               udpstat.udps_fullsock++;
+       } else {
                sorwakeup(inp->inp_socket);
        }
        udp_unlock(inp->inp_socket, 1, 0);
-       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0,0,0,0,0);
+       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0, 0, 0, 0, 0);
        return;
 bad:
        m_freem(m);
        if (opts)
                m_freem(opts);
-       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0,0,0,0,0);
-       return;
+       KERNEL_DEBUG(DBG_FNC_UDP_INPUT | DBG_FUNC_END, 0, 0, 0, 0, 0);
 }
 
 #if INET6
 static void
-ip_2_ip6_hdr(ip6, ip)
-       struct ip6_hdr *ip6;
-       struct ip *ip;
+ip_2_ip6_hdr(struct ip6_hdr *ip6, struct ip *ip)
 {
-       bzero(ip6, sizeof(*ip6));
+       bzero(ip6, sizeof (*ip6));
 
        ip6->ip6_vfc = IPV6_VERSION;
        ip6->ip6_plen = ip->ip_len;
        ip6->ip6_nxt = ip->ip_p;
        ip6->ip6_hlim = ip->ip_ttl;
-       ip6->ip6_src.s6_addr32[2] = ip6->ip6_dst.s6_addr32[2] =
-               IPV6_ADDR_INT32_SMP;
-       ip6->ip6_src.s6_addr32[3] = ip->ip_src.s_addr;
-       ip6->ip6_dst.s6_addr32[3] = ip->ip_dst.s_addr;
+       if (ip->ip_src.s_addr) {
+               ip6->ip6_src.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
+               ip6->ip6_src.s6_addr32[3] = ip->ip_src.s_addr;
+       }
+       if (ip->ip_dst.s_addr) {
+               ip6->ip6_dst.s6_addr32[2] = IPV6_ADDR_INT32_SMP;
+               ip6->ip6_dst.s6_addr32[3] = ip->ip_dst.s_addr;
+       }
 }
-#endif
+#endif /* INET6 */
 
 /*
  * subroutine of udp_input(), mainly for source code readability.
@@ -714,23 +789,28 @@ static void
 #if INET6
 udp_append(struct inpcb *last, struct ip *ip, struct mbuf *n, int off,
     struct sockaddr_in *pudp_in, struct udp_in6 *pudp_in6,
-    struct udp_ip6 *pudp_ip6)
-#else
+    struct udp_ip6 *pudp_ip6, struct ifnet *ifp)
+#else /* !INET6 */
 udp_append(struct inpcb *last, struct ip *ip, struct mbuf *n, int off,
-    struct sockaddr_in *pudp_in)
-#endif
+    struct sockaddr_in *pudp_in, struct ifnet *ifp)
+#endif /* !INET6 */
 {
        struct sockaddr *append_sa;
        struct mbuf *opts = 0;
+       boolean_t cell = IFNET_IS_CELLULAR(ifp);
+       boolean_t wifi = (!cell && IFNET_IS_WIFI(ifp));
+       boolean_t wired = (!wifi && IFNET_IS_WIRED(ifp));
+       int ret = 0;
 
 #if CONFIG_MACF_NET
        if (mac_inpcb_check_deliver(last, n, AF_INET, SOCK_DGRAM) != 0) {
                m_freem(n);
                return;
        }
-#endif
-       if (last->inp_flags & INP_CONTROLOPTS ||
-           last->inp_socket->so_options & SO_TIMESTAMP) {
+#endif /* CONFIG_MACF_NET */
+       if ((last->inp_flags & INP_CONTROLOPTS) != 0 ||
+           (last->inp_socket->so_options & SO_TIMESTAMP) != 0 ||
+           (last->inp_socket->so_options & SO_TIMESTAMP_MONOTONIC) != 0) {
 #if INET6
                if (last->inp_vflag & INP_IPV6) {
                        int savedflags;
@@ -741,11 +821,20 @@ udp_append(struct inpcb *last, struct ip *ip, struct mbuf *n, int off,
                        }
                        savedflags = last->inp_flags;
                        last->inp_flags &= ~INP_UNMAPPABLEOPTS;
-                       ip6_savecontrol(last, &opts, &pudp_ip6->uip6_ip6, n);
+                       ret = ip6_savecontrol(last, n, &opts);
+                       if (ret != 0) {
+                               last->inp_flags = savedflags;
+                               goto error;
+                       }
                        last->inp_flags = savedflags;
                } else
-#endif
-               ip_savecontrol(last, &opts, ip, n);
+#endif /* INET6 */
+               {
+                       ret = ip_savecontrol(last, &opts, ip, n);
+                       if (ret != 0) {
+                               goto error;
+                       }
+               }
        }
 #if INET6
        if (last->inp_vflag & INP_IPV6) {
@@ -755,13 +844,25 @@ udp_append(struct inpcb *last, struct ip *ip, struct mbuf *n, int off,
                }
                append_sa = (struct sockaddr *)&pudp_in6->uin6_sin;
        } else
-#endif
+#endif /* INET6 */
        append_sa = (struct sockaddr *)pudp_in;
+       if (nstat_collect) {
+               INP_ADD_STAT(last, cell, wifi, wired, rxpackets, 1);
+               INP_ADD_STAT(last, cell, wifi, wired, rxbytes,
+                   n->m_pkthdr.len);
+       }
+       so_recv_data_stat(last->inp_socket, n, 0);
        m_adj(n, off);
-       if (sbappendaddr(&last->inp_socket->so_rcv, append_sa, n, opts, NULL) == 0) {
+       if (sbappendaddr(&last->inp_socket->so_rcv, append_sa,
+           n, opts, NULL) == 0) {
                udpstat.udps_fullsock++;
-       } else
+       } else {
                sorwakeup(last->inp_socket);
+       }
+       return;
+error:
+       m_freem(n);
+       m_freem(opts);
 }
 
 /*
@@ -769,9 +870,7 @@ udp_append(struct inpcb *last, struct ip *ip, struct mbuf *n, int off,
  * just wake up so that he can collect error status.
  */
 void
-udp_notify(inp, errno)
-       register struct inpcb *inp;
-       int errno;
+udp_notify(struct inpcb *inp, int errno)
 {
        inp->inp_socket->so_error = errno;
        sorwakeup(inp->inp_socket);
@@ -779,43 +878,44 @@ udp_notify(inp, errno)
 }
 
 void
-udp_ctlinput(cmd, sa, vip)
-       int cmd;
-       struct sockaddr *sa;
-       void *vip;
+udp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 {
        struct ip *ip = vip;
-       struct udphdr *uh;
        void (*notify)(struct inpcb *, int) = udp_notify;
-        struct in_addr faddr;
+       struct in_addr faddr;
        struct inpcb *inp;
 
-       faddr = ((struct sockaddr_in *)sa)->sin_addr;
+       faddr = ((struct sockaddr_in *)(void *)sa)->sin_addr;
        if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
-               return;
+               return;
 
        if (PRC_IS_REDIRECT(cmd)) {
                ip = 0;
                notify = in_rtchange;
-       } else if (cmd == PRC_HOSTDEAD)
+       } else if (cmd == PRC_HOSTDEAD) {
                ip = 0;
-       else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
+       } else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) {
                return;
+       }
        if (ip) {
-               uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
-               inp = in_pcblookup_hash(&udbinfo, faddr, uh->uh_dport,
-                    ip->ip_src, uh->uh_sport, 0, NULL);
+               struct udphdr uh;
+
+               bcopy(((caddr_t)ip + (ip->ip_hl << 2)), &uh, sizeof (uh));
+               inp = in_pcblookup_hash(&udbinfo, faddr, uh.uh_dport,
+                   ip->ip_src, uh.uh_sport, 0, NULL);
                if (inp != NULL && inp->inp_socket != NULL) {
                        udp_lock(inp->inp_socket, 1, 0);
-                       if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING)  {
+                       if (in_pcb_checkstate(inp, WNT_RELEASE, 1) ==
+                           WNT_STOPUSING)  {
                                udp_unlock(inp->inp_socket, 1, 0);
                                return;
                        }
                        (*notify)(inp, inetctlerrmap[cmd]);
                        udp_unlock(inp->inp_socket, 1, 0);
                }
-       } else
+       } else {
                in_pcbnotifyall(&udbinfo, faddr, inetctlerrmap[cmd], notify);
+       }
 }
 
 int
@@ -824,7 +924,9 @@ udp_ctloutput(struct socket *so, struct sockopt *sopt)
        int     error, optval;
        struct  inpcb *inp;
 
-       if (sopt->sopt_level != IPPROTO_UDP)
+       /* Allow <SOL_SOCKET,SO_FLUSH> at this level */
+       if (sopt->sopt_level != IPPROTO_UDP &&
+           !(sopt->sopt_level == SOL_SOCKET && sopt->sopt_name == SO_FLUSH))
                return (ip_ctloutput(so, sopt));
 
        error = 0;
@@ -849,6 +951,85 @@ udp_ctloutput(struct socket *so, struct sockopt *sopt)
                        else
                                inp->inp_flags &= ~INP_UDP_NOCKSUM;
                        break;
+               case UDP_KEEPALIVE_OFFLOAD:
+               {
+                       struct udp_keepalive_offload ka;
+                       /*
+                        * If the socket is not connected, the stack will
+                        * not know the destination address to put in the
+                        * keepalive datagram. Return an error now instead
+                        * of failing later.
+                        */
+                       if (!(so->so_state & SS_ISCONNECTED)) {
+                               error = EINVAL;
+                               break;
+                       }
+                       if (sopt->sopt_valsize != sizeof(ka)) {
+                               error = EINVAL;
+                               break;
+                       }
+                       if ((error = sooptcopyin(sopt, &ka, sizeof(ka),
+                           sizeof(ka))) != 0)
+                               break;
+
+                       /* application should specify the type */
+                       if (ka.ka_type == 0)
+                               return (EINVAL);
+
+                       if (ka.ka_interval == 0) {
+                               /*
+                                * if interval is 0, disable the offload
+                                * mechanism
+                                */
+                               if (inp->inp_keepalive_data != NULL)
+                                       FREE(inp->inp_keepalive_data,
+                                           M_TEMP);
+                               inp->inp_keepalive_data = NULL;
+                               inp->inp_keepalive_datalen = 0;
+                               inp->inp_keepalive_interval = 0;
+                               inp->inp_keepalive_type = 0;
+                               inp->inp_flags2 &= ~INP2_KEEPALIVE_OFFLOAD;
+                       } else {
+                               if (inp->inp_keepalive_data != NULL) {
+                                       FREE(inp->inp_keepalive_data,
+                                           M_TEMP);
+                                       inp->inp_keepalive_data = NULL;
+                               }
+
+                               inp->inp_keepalive_datalen = min(
+                                   ka.ka_data_len,
+                                   UDP_KEEPALIVE_OFFLOAD_DATA_SIZE);
+                               if (inp->inp_keepalive_datalen > 0) {
+                                       MALLOC(inp->inp_keepalive_data,
+                                           u_int8_t *,
+                                           inp->inp_keepalive_datalen,
+                                           M_TEMP, M_WAITOK);
+                                       if (inp->inp_keepalive_data == NULL) {
+                                               inp->inp_keepalive_datalen = 0;
+                                               error = ENOMEM;
+                                               break;
+                                       }
+                                       bcopy(ka.ka_data,
+                                           inp->inp_keepalive_data,
+                                           inp->inp_keepalive_datalen);
+                               } else {
+                                       inp->inp_keepalive_datalen = 0;
+                               }
+                               inp->inp_keepalive_interval =
+                                   min(UDP_KEEPALIVE_INTERVAL_MAX_SECONDS,
+                                   ka.ka_interval);
+                               inp->inp_keepalive_type = ka.ka_type;
+                               inp->inp_flags2 |= INP2_KEEPALIVE_OFFLOAD;
+                       }
+                       break;
+               }
+               case SO_FLUSH:
+                       if ((error = sooptcopyin(sopt, &optval, sizeof (optval),
+                           sizeof (optval))) != 0)
+                               break;
+
+                       error = inp_flush(inp, optval);
+                       break;
 
                default:
                        error = ENOPROTOOPT;
@@ -886,18 +1067,18 @@ udp_pcblist SYSCTL_HANDLER_ARGS
         * The process of preparing the TCB list is too time-consuming and
         * resource-intensive to repeat twice on every request.
         */
-       lck_rw_lock_exclusive(udbinfo.mtx);
+       lck_rw_lock_exclusive(udbinfo.ipi_lock);
        if (req->oldptr == USER_ADDR_NULL) {
                n = udbinfo.ipi_count;
-               req->oldidx = 2 * (sizeof xig)
-                       + (n + n/8) * sizeof(struct xinpcb);
-               lck_rw_done(udbinfo.mtx);
-               return 0;
+               req->oldidx = 2 * (sizeof (xig))
+                       + (n + n/8) * sizeof (struct xinpcb);
+               lck_rw_done(udbinfo.ipi_lock);
+               return (0);
        }
 
        if (req->newptr != USER_ADDR_NULL) {
-               lck_rw_done(udbinfo.mtx);
-               return EPERM;
+               lck_rw_done(udbinfo.ipi_lock);
+               return (EPERM);
        }
 
        /*
@@ -906,51 +1087,66 @@ udp_pcblist SYSCTL_HANDLER_ARGS
        gencnt = udbinfo.ipi_gencnt;
        n = udbinfo.ipi_count;
 
-       bzero(&xig, sizeof(xig));
-       xig.xig_len = sizeof xig;
+       bzero(&xig, sizeof (xig));
+       xig.xig_len = sizeof (xig);
        xig.xig_count = n;
        xig.xig_gen = gencnt;
        xig.xig_sogen = so_gencnt;
-       error = SYSCTL_OUT(req, &xig, sizeof xig);
+       error = SYSCTL_OUT(req, &xig, sizeof (xig));
        if (error) {
-               lck_rw_done(udbinfo.mtx);
-               return error;
-       }
-    /*
-     * We are done if there is no pcb
-     */
-    if (n == 0) {
-       lck_rw_done(udbinfo.mtx);
-        return 0; 
-    }
-
-       inp_list = _MALLOC(n * sizeof *inp_list, M_TEMP, M_WAITOK);
+               lck_rw_done(udbinfo.ipi_lock);
+               return (error);
+       }
+       /*
+        * We are done if there is no pcb
+        */
+       if (n == 0) {
+               lck_rw_done(udbinfo.ipi_lock);
+               return (0);
+       }
+
+       inp_list = _MALLOC(n * sizeof (*inp_list), M_TEMP, M_WAITOK);
        if (inp_list == 0) {
-               lck_rw_done(udbinfo.mtx);
-               return ENOMEM;
+               lck_rw_done(udbinfo.ipi_lock);
+               return (ENOMEM);
        }
-       
-       for (inp = LIST_FIRST(udbinfo.listhead), i = 0; inp && i < n;
-            inp = LIST_NEXT(inp, inp_list)) {
-               if (inp->inp_gencnt <= gencnt && inp->inp_state != INPCB_STATE_DEAD)
+
+       for (inp = LIST_FIRST(udbinfo.ipi_listhead), i = 0; inp && i < n;
+           inp = LIST_NEXT(inp, inp_list)) {
+               if (inp->inp_gencnt <= gencnt &&
+                   inp->inp_state != INPCB_STATE_DEAD)
                        inp_list[i++] = inp;
        }
        n = i;
 
        error = 0;
        for (i = 0; i < n; i++) {
+               struct xinpcb xi;
+
                inp = inp_list[i];
-               if (inp->inp_gencnt <= gencnt && inp->inp_state != INPCB_STATE_DEAD) {
-                       struct xinpcb xi;
-
-                       bzero(&xi, sizeof(xi));
-                       xi.xi_len = sizeof xi;
-                       /* XXX should avoid extra copy */
-                       inpcb_to_compat(inp, &xi.xi_inp);
-                       if (inp->inp_socket)
-                               sotoxsocket(inp->inp_socket, &xi.xi_socket);
-                       error = SYSCTL_OUT(req, &xi, sizeof xi);
+
+               if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING)
+                       continue;
+               udp_lock(inp->inp_socket, 1, 0);
+               if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) {
+                       udp_unlock(inp->inp_socket, 1, 0);
+                       continue;
+               }
+               if (inp->inp_gencnt > gencnt) {
+                       udp_unlock(inp->inp_socket, 1, 0);
+                       continue;
                }
+
+               bzero(&xi, sizeof (xi));
+               xi.xi_len = sizeof (xi);
+               /* XXX should avoid extra copy */
+               inpcb_to_compat(inp, &xi.xi_inp);
+               if (inp->inp_socket)
+                       sotoxsocket(inp->inp_socket, &xi.xi_socket);
+
+               udp_unlock(inp->inp_socket, 1, 0);
+
+               error = SYSCTL_OUT(req, &xi, sizeof (xi));
        }
        if (!error) {
                /*
@@ -960,135 +1156,455 @@ udp_pcblist SYSCTL_HANDLER_ARGS
                 * while we were processing this request, and it
                 * might be necessary to retry.
                 */
-               bzero(&xig, sizeof(xig));
-               xig.xig_len = sizeof xig;
+               bzero(&xig, sizeof (xig));
+               xig.xig_len = sizeof (xig);
                xig.xig_gen = udbinfo.ipi_gencnt;
                xig.xig_sogen = so_gencnt;
                xig.xig_count = udbinfo.ipi_count;
-               error = SYSCTL_OUT(req, &xig, sizeof xig);
+               error = SYSCTL_OUT(req, &xig, sizeof (xig));
        }
        FREE(inp_list, M_TEMP);
-       lck_rw_done(udbinfo.mtx);
-       return error;
+       lck_rw_done(udbinfo.ipi_lock);
+       return (error);
 }
 
-SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
-           udp_pcblist, "S,xinpcb", "List of active UDP sockets");
-
-
-
-static __inline__ u_int16_t
-get_socket_id(struct socket * s)
-{
-       u_int16_t               val;
+SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist,
+       CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0, 0, udp_pcblist,
+       "S,xinpcb", "List of active UDP sockets");
 
-       if (s == NULL) {
-           return (0);
-       }
-       val = (u_int16_t)(((u_int32_t)s) / sizeof(struct socket));
-       if (val == 0) {
-               val = 0xffff;
-       }
-       return (val);
-}
 
 static int
-udp_output(inp, m, addr, control, p)
-       register struct inpcb *inp;
-       struct mbuf *m;
-       struct sockaddr *addr;
-       struct mbuf *control;
-       struct proc *p;
+udp_pcblist64 SYSCTL_HANDLER_ARGS
 {
-       register struct udpiphdr *ui;
-       register int len = m->m_pkthdr.len;
-       struct sockaddr_in *sin;
-       struct in_addr origladdr, laddr, faddr;
-       u_short lport, fport;
-       struct sockaddr_in *ifaddr;
-       int error = 0, udp_dodisconnect = 0;
-       struct socket *so = inp->inp_socket;
-       int soopts;
-       struct mbuf *inpopts;
-       struct ip_moptions *mopts;
-       struct route ro;
-
-       KERNEL_DEBUG(DBG_FNC_UDP_OUTPUT | DBG_FUNC_START, 0,0,0,0,0);
-
-       if (control)
-               m_freem(control);               /* XXX */
+#pragma unused(oidp, arg1, arg2)
+       int error, i, n;
+       struct inpcb *inp, **inp_list;
+       inp_gen_t gencnt;
+       struct xinpgen xig;
 
-       KERNEL_DEBUG(DBG_LAYER_OUT_BEG, inp->inp_fport, inp->inp_lport,
-                    inp->inp_laddr.s_addr, inp->inp_faddr.s_addr,
-                    (htons((u_short)len + sizeof (struct udphdr))));
+       /*
+        * The process of preparing the TCB list is too time-consuming and
+        * resource-intensive to repeat twice on every request.
+        */
+       lck_rw_lock_shared(udbinfo.ipi_lock);
+       if (req->oldptr == USER_ADDR_NULL) {
+               n = udbinfo.ipi_count;
+               req->oldidx =
+                   2 * (sizeof (xig)) + (n + n/8) * sizeof (struct xinpcb64);
+               lck_rw_done(udbinfo.ipi_lock);
+               return (0);
+       }
 
-       if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
-               error = EMSGSIZE;
-               goto release;
+       if (req->newptr != USER_ADDR_NULL) {
+               lck_rw_done(udbinfo.ipi_lock);
+               return (EPERM);
        }
 
-       /* If there was a routing change, discard cached route and check
-        * that we have a valid source address. 
-        * Reacquire a new source address if INADDR_ANY was specified
+       /*
+        * OK, now we're committed to doing something.
         */
+       gencnt = udbinfo.ipi_gencnt;
+       n = udbinfo.ipi_count;
 
-#if 1
-        lck_mtx_assert(inp->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
-#endif
+       bzero(&xig, sizeof (xig));
+       xig.xig_len = sizeof (xig);
+       xig.xig_count = n;
+       xig.xig_gen = gencnt;
+       xig.xig_sogen = so_gencnt;
+       error = SYSCTL_OUT(req, &xig, sizeof (xig));
+       if (error) {
+               lck_rw_done(udbinfo.ipi_lock);
+               return (error);
+       }
+       /*
+        * We are done if there is no pcb
+        */
+       if (n == 0) {
+               lck_rw_done(udbinfo.ipi_lock);
+               return (0);
+       }
 
-       if (inp->inp_route.ro_rt && inp->inp_route.ro_rt->generation_id != route_generation) {
-               if (ifa_foraddr(inp->inp_laddr.s_addr) == 0) { /* src address is gone */
-                       if (inp->inp_flags & INP_INADDR_ANY)
-                               inp->inp_laddr.s_addr = INADDR_ANY; /* new src will be set later */
-                       else {
-                               error = EADDRNOTAVAIL;
-                               goto release;
-                       }
-               }
-               rtfree(inp->inp_route.ro_rt);
-               inp->inp_route.ro_rt = (struct rtentry *)0;
+       inp_list = _MALLOC(n * sizeof (*inp_list), M_TEMP, M_WAITOK);
+       if (inp_list == 0) {
+               lck_rw_done(udbinfo.ipi_lock);
+               return (ENOMEM);
        }
 
-       origladdr= laddr = inp->inp_laddr;
-       faddr = inp->inp_faddr;
-       lport = inp->inp_lport;
-       fport = inp->inp_fport;
+       for (inp = LIST_FIRST(udbinfo.ipi_listhead), i = 0; inp && i < n;
+           inp = LIST_NEXT(inp, inp_list)) {
+               if (inp->inp_gencnt <= gencnt &&
+                   inp->inp_state != INPCB_STATE_DEAD)
+                       inp_list[i++] = inp;
+       }
+       n = i;
+
+       error = 0;
+       for (i = 0; i < n; i++) {
+               struct xinpcb64 xi;
+
+               inp = inp_list[i];
+
+               if (in_pcb_checkstate(inp, WNT_ACQUIRE, 0) == WNT_STOPUSING)
+                       continue;
+               udp_lock(inp->inp_socket, 1, 0);
+               if (in_pcb_checkstate(inp, WNT_RELEASE, 1) == WNT_STOPUSING) {
+                       udp_unlock(inp->inp_socket, 1, 0);
+                       continue;
+               }
+               if (inp->inp_gencnt > gencnt) {
+                       udp_unlock(inp->inp_socket, 1, 0);
+                       continue;
+               }
+
+               bzero(&xi, sizeof (xi));
+               xi.xi_len = sizeof (xi);
+               inpcb_to_xinpcb64(inp, &xi);
+               if (inp->inp_socket)
+                       sotoxsocket64(inp->inp_socket, &xi.xi_socket);
+
+               udp_unlock(inp->inp_socket, 1, 0);
+
+               error = SYSCTL_OUT(req, &xi, sizeof (xi));
+       }
+       if (!error) {
+               /*
+                * Give the user an updated idea of our state.
+                * If the generation differs from what we told
+                * her before, she knows that something happened
+                * while we were processing this request, and it
+                * might be necessary to retry.
+                */
+               bzero(&xig, sizeof (xig));
+               xig.xig_len = sizeof (xig);
+               xig.xig_gen = udbinfo.ipi_gencnt;
+               xig.xig_sogen = so_gencnt;
+               xig.xig_count = udbinfo.ipi_count;
+               error = SYSCTL_OUT(req, &xig, sizeof (xig));
+       }
+       FREE(inp_list, M_TEMP);
+       lck_rw_done(udbinfo.ipi_lock);
+       return (error);
+}
+
+SYSCTL_PROC(_net_inet_udp, OID_AUTO, pcblist64,
+       CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0, 0, udp_pcblist64,
+       "S,xinpcb64", "List of active UDP sockets");
+
+
+static int
+udp_pcblist_n SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp, arg1, arg2)
+       return (get_pcblist_n(IPPROTO_UDP, req, &udbinfo));
+}
+
+SYSCTL_PROC(_net_inet_udp, OID_AUTO, pcblist_n,
+       CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED, 0, 0, udp_pcblist_n,
+       "S,xinpcb_n", "List of active UDP sockets");
+
+__private_extern__ void
+udp_get_ports_used(uint32_t ifindex, int protocol, uint32_t flags,
+    bitstr_t *bitfield)
+{
+       inpcb_get_ports_used(ifindex, protocol, flags, bitfield, &udbinfo);
+}
+
+__private_extern__ uint32_t
+udp_count_opportunistic(unsigned int ifindex, u_int32_t flags)
+{
+       return (inpcb_count_opportunistic(ifindex, &udbinfo, flags));
+}
+
+__private_extern__ uint32_t
+udp_find_anypcb_byaddr(struct ifaddr *ifa)
+{
+       return (inpcb_find_anypcb_byaddr(ifa, &udbinfo));
+}
+
+static int
+udp_check_pktinfo(struct mbuf *control, struct ifnet **outif,
+    struct in_addr *laddr)
+{
+       struct cmsghdr *cm = 0;
+       struct in_pktinfo *pktinfo;
+       struct ifnet *ifp;
+
+       if (outif != NULL)
+               *outif = NULL;
+
+       /*
+        * XXX: Currently, we assume all the optional information is stored
+        * in a single mbuf.
+        */
+       if (control->m_next)
+               return (EINVAL);
+
+       if (control->m_len < CMSG_LEN(0))
+               return (EINVAL);
+
+       for (cm = M_FIRST_CMSGHDR(control); cm;
+           cm = M_NXT_CMSGHDR(control, cm)) {
+               if (cm->cmsg_len < sizeof (struct cmsghdr) ||
+                   cm->cmsg_len > control->m_len)
+                       return (EINVAL);
+
+               if (cm->cmsg_level != IPPROTO_IP || cm->cmsg_type != IP_PKTINFO)
+                       continue;
+
+               if (cm->cmsg_len != CMSG_LEN(sizeof (struct in_pktinfo)))
+                       return (EINVAL);
+
+               pktinfo =  (struct in_pktinfo *)(void *)CMSG_DATA(cm);
+
+               /* Check for a valid ifindex in pktinfo */
+               ifnet_head_lock_shared();
+
+               if (pktinfo->ipi_ifindex > if_index) {
+                       ifnet_head_done();
+                       return (ENXIO);
+               }
+
+               /*
+                * If ipi_ifindex is specified it takes precedence
+                * over ipi_spec_dst.
+                */
+               if (pktinfo->ipi_ifindex) {
+                       ifp = ifindex2ifnet[pktinfo->ipi_ifindex];
+                       if (ifp == NULL) {
+                               ifnet_head_done();
+                               return (ENXIO);
+                       }
+                       if (outif != NULL) {
+                               ifnet_reference(ifp);
+                               *outif = ifp;
+                       }
+                       ifnet_head_done();
+                       laddr->s_addr = INADDR_ANY;
+                       break;
+               }
+
+               ifnet_head_done();
+
+               /*
+                * Use the provided ipi_spec_dst address for temp
+                * source address.
+                */
+               *laddr = pktinfo->ipi_spec_dst;
+               break;
+       }
+       return (0);
+}
+
+static int
+udp_output(struct inpcb *inp, struct mbuf *m, struct sockaddr *addr,
+    struct mbuf *control, struct proc *p)
+{
+       struct udpiphdr *ui;
+       int len = m->m_pkthdr.len;
+       struct sockaddr_in *sin;
+       struct in_addr origladdr, laddr, faddr, pi_laddr;
+       u_short lport, fport;
+       int error = 0, udp_dodisconnect = 0, pktinfo = 0;
+       struct socket *so = inp->inp_socket;
+       int soopts = 0;
+       struct mbuf *inpopts;
+       struct ip_moptions *mopts;
+       struct route ro;
+       struct ip_out_args ipoa =
+           { IFSCOPE_NONE, { 0 }, IPOAF_SELECT_SRCIF, 0, 0, 0 };
+       struct ifnet *outif = NULL;
+       struct flowadv *adv = &ipoa.ipoa_flowadv;
+       int sotc = SO_TC_UNSPEC;
+       int netsvctype = _NET_SERVICE_TYPE_UNSPEC;
+       struct ifnet *origoutifp = NULL;
+       int flowadv = 0;
+
+       /* Enable flow advisory only when connected */
+       flowadv = (so->so_state & SS_ISCONNECTED) ? 1 : 0;
+       pi_laddr.s_addr = INADDR_ANY;
+
+       KERNEL_DEBUG(DBG_FNC_UDP_OUTPUT | DBG_FUNC_START, 0, 0, 0, 0, 0);
+
+       lck_mtx_assert(&inp->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
+       if (control != NULL) {
+               sotc = so_tc_from_control(control, &netsvctype);
+               VERIFY(outif == NULL);
+               error = udp_check_pktinfo(control, &outif, &pi_laddr);
+               m_freem(control);
+               control = NULL;
+               if (error)
+                       goto release;
+               pktinfo++;
+               if (outif != NULL)
+                       ipoa.ipoa_boundif = outif->if_index;
+       }
+       if (sotc == SO_TC_UNSPEC) {
+               sotc = so->so_traffic_class;
+               netsvctype = so->so_netsvctype;
+       }
+
+       KERNEL_DEBUG(DBG_LAYER_OUT_BEG, inp->inp_fport, inp->inp_lport,
+           inp->inp_laddr.s_addr, inp->inp_faddr.s_addr,
+           (htons((u_short)len + sizeof (struct udphdr))));
+
+       if (len + sizeof (struct udpiphdr) > IP_MAXPACKET) {
+               error = EMSGSIZE;
+               goto release;
+       }
+
+       if (flowadv && INP_WAIT_FOR_IF_FEEDBACK(inp)) {
+               /*
+                * The socket is flow-controlled, drop the packets
+                * until the inp is not flow controlled
+                */
+               error = ENOBUFS;
+               goto release;
+       }
+       /*
+        * If socket was bound to an ifindex, tell ip_output about it.
+        * If the ancillary IP_PKTINFO option contains an interface index,
+        * it takes precedence over the one specified by IP_BOUND_IF.
+        */
+       if (ipoa.ipoa_boundif == IFSCOPE_NONE &&
+           (inp->inp_flags & INP_BOUND_IF)) {
+               VERIFY(inp->inp_boundifp != NULL);
+               ifnet_reference(inp->inp_boundifp);     /* for this routine */
+               if (outif != NULL)
+                       ifnet_release(outif);
+               outif = inp->inp_boundifp;
+               ipoa.ipoa_boundif = outif->if_index;
+       }
+       if (INP_NO_CELLULAR(inp))
+               ipoa.ipoa_flags |=  IPOAF_NO_CELLULAR;
+       if (INP_NO_EXPENSIVE(inp))
+               ipoa.ipoa_flags |=  IPOAF_NO_EXPENSIVE;
+       if (INP_AWDL_UNRESTRICTED(inp))
+               ipoa.ipoa_flags |=  IPOAF_AWDL_UNRESTRICTED;
+       ipoa.ipoa_sotc = sotc;
+       ipoa.ipoa_netsvctype = netsvctype;
+       soopts |= IP_OUTARGS;
+
+       /*
+        * If there was a routing change, discard cached route and check
+        * that we have a valid source address.  Reacquire a new source
+        * address if INADDR_ANY was specified.
+        */
+       if (ROUTE_UNUSABLE(&inp->inp_route)) {
+               struct in_ifaddr *ia = NULL;
+
+               ROUTE_RELEASE(&inp->inp_route);
+
+               /* src address is gone? */
+               if (inp->inp_laddr.s_addr != INADDR_ANY &&
+                   (ia = ifa_foraddr(inp->inp_laddr.s_addr)) == NULL) {
+                       if (!(inp->inp_flags & INP_INADDR_ANY) ||
+                           (so->so_state & SS_ISCONNECTED)) {
+                               /*
+                                * Rdar://5448998
+                                * If the source address is gone, return an
+                                * error if:
+                                * - the source was specified
+                                * - the socket was already connected
+                                */
+                               soevent(so, (SO_FILT_HINT_LOCKED |
+                                   SO_FILT_HINT_NOSRCADDR));
+                               error = EADDRNOTAVAIL;
+                               goto release;
+                       } else {
+                               /* new src will be set later */
+                               inp->inp_laddr.s_addr = INADDR_ANY;
+                               inp->inp_last_outifp = NULL;
+                       }
+               }
+               if (ia != NULL)
+                       IFA_REMREF(&ia->ia_ifa);
+       }
+
+       /*
+        * IP_PKTINFO option check.  If a temporary scope or src address
+        * is provided, use it for this packet only and make sure we forget
+        * it after sending this datagram.
+        */
+       if (pi_laddr.s_addr != INADDR_ANY ||
+           (ipoa.ipoa_boundif != IFSCOPE_NONE && pktinfo)) {
+               /* temp src address for this datagram only */
+               laddr = pi_laddr;
+               origladdr.s_addr = INADDR_ANY;
+               /* we don't want to keep the laddr or route */
+               udp_dodisconnect = 1;
+               /* remember we don't care about src addr */
+               inp->inp_flags |= INP_INADDR_ANY;
+       } else {
+               origladdr = laddr = inp->inp_laddr;
+       }
+
+       origoutifp = inp->inp_last_outifp;
+       faddr = inp->inp_faddr;
+       lport = inp->inp_lport;
+       fport = inp->inp_fport;
 
        if (addr) {
-               sin = (struct sockaddr_in *)addr;
+               sin = (struct sockaddr_in *)(void *)addr;
                if (faddr.s_addr != INADDR_ANY) {
                        error = EISCONN;
                        goto release;
                }
                if (lport == 0) {
                        /*
-                        * In case we don't have a local port set, go through the full connect.
-                        * We don't have a local port yet (ie, we can't be looked up),
-                        * so it's not an issue if the input runs at the same time we do this.
-                        */
-                       error = in_pcbconnect(inp, addr, p);
-                       if (error) {
+                        * In case we don't have a local port set, go through
+                        * the full connect.  We don't have a local port yet
+                        * (i.e., we can't be looked up), so it's not an issue
+                        * if the input runs at the same time we do this.
+                        */
+                       /* if we have a source address specified, use that */
+                       if (pi_laddr.s_addr != INADDR_ANY)
+                               inp->inp_laddr = pi_laddr;
+                       /*
+                        * If a scope is specified, use it.  Scope from
+                        * IP_PKTINFO takes precendence over the the scope
+                        * set via INP_BOUND_IF.
+                        */
+                       error = in_pcbconnect(inp, addr, p, ipoa.ipoa_boundif,
+                           &outif);
+                       if (error)
                                goto release;
-                       }
+
                        laddr = inp->inp_laddr;
                        lport = inp->inp_lport;
                        faddr = inp->inp_faddr;
                        fport = inp->inp_fport;
                        udp_dodisconnect = 1;
-               }
-               else {  
-                       /* Fast path case
-                        * we have a full address and a local port.
-                        * use those info to build the packet without changing the pcb
-                        * and interfering with the input path. See 3851370
+
+                       /* synch up in case in_pcbladdr() overrides */
+                       if (outif != NULL && ipoa.ipoa_boundif != IFSCOPE_NONE)
+                               ipoa.ipoa_boundif = outif->if_index;
+               } else {
+                       /*
+                        * Fast path case
+                        *
+                        * We have a full address and a local port; use those
+                        * info to build the packet without changing the pcb
+                        * and interfering with the input path. See 3851370.
+                        *
+                        * Scope from IP_PKTINFO takes precendence over the
+                        * the scope set via INP_BOUND_IF.
                         */
                        if (laddr.s_addr == INADDR_ANY) {
-                          if ((error = in_pcbladdr(inp, addr, &ifaddr)) != 0)
-                                  goto release;
-                          laddr = ifaddr->sin_addr;
-                          inp->inp_flags |= INP_INADDR_ANY; /* from pcbconnect: remember we don't care about src addr.*/
+                               if ((error = in_pcbladdr(inp, addr, &laddr,
+                                   ipoa.ipoa_boundif, &outif, 0)) != 0)
+                                       goto release;
+                               /*
+                                * from pcbconnect: remember we don't
+                                * care about src addr.
+                                */
+                               inp->inp_flags |= INP_INADDR_ANY;
+
+                               /* synch up in case in_pcbladdr() overrides */
+                               if (outif != NULL &&
+                                   ipoa.ipoa_boundif != IFSCOPE_NONE)
+                                       ipoa.ipoa_boundif = outif->if_index;
                        }
-                                  
+
                        faddr = sin->sin_addr;
                        fport = sin->sin_port;
                }
@@ -1101,14 +1617,16 @@ udp_output(inp, m, addr, control, p)
 
 #if CONFIG_MACF_NET
        mac_mbuf_label_associate_inpcb(inp, m);
-#endif
+#endif /* CONFIG_MACF_NET */
 
+       if (inp->inp_flowhash == 0)
+               inp->inp_flowhash = inp_calc_flowhash(inp);
 
        /*
         * Calculate data length and get a mbuf
         * for UDP and IP headers.
         */
-       M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
+       M_PREPEND(m, sizeof (struct udpiphdr), M_DONTWAIT, 1);
        if (m == 0) {
                error = ENOBUFS;
                goto abort;
@@ -1119,20 +1637,20 @@ udp_output(inp, m, addr, control, p)
         * and addresses and length put into network format.
         */
        ui = mtod(m, struct udpiphdr *);
-       bzero(ui->ui_x1, sizeof(ui->ui_x1));    /* XXX still needed? */
+       bzero(ui->ui_x1, sizeof (ui->ui_x1));   /* XXX still needed? */
        ui->ui_pr = IPPROTO_UDP;
        ui->ui_src = laddr;
        ui->ui_dst = faddr;
        ui->ui_sport = lport;
        ui->ui_dport = fport;
-       ui->ui_ulen = htons((u_short)len + sizeof(struct udphdr));
+       ui->ui_ulen = htons((u_short)len + sizeof (struct udphdr));
 
        /*
         * Set up checksum and output datagram.
         */
        if (udpcksum && !(inp->inp_flags & INP_UDP_NOCKSUM)) {
-               ui->ui_sum = in_pseudo(ui->ui_src.s_addr, ui->ui_dst.s_addr,
-                   htons((u_short)len + sizeof(struct udphdr) + IPPROTO_UDP));
+               ui->ui_sum = in_pseudo(ui->ui_src.s_addr, ui->ui_dst.s_addr,
+                   htons((u_short)len + sizeof (struct udphdr) + IPPROTO_UDP));
                m->m_pkthdr.csum_flags = CSUM_UDP;
                m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
        } else {
@@ -1144,68 +1662,247 @@ udp_output(inp, m, addr, control, p)
        udpstat.udps_opackets++;
 
        KERNEL_DEBUG(DBG_LAYER_OUT_END, ui->ui_dport, ui->ui_sport,
-                    ui->ui_src.s_addr, ui->ui_dst.s_addr, ui->ui_ulen);
+           ui->ui_src.s_addr, ui->ui_dst.s_addr, ui->ui_ulen);
+
+#if NECP
+       {
+               necp_kernel_policy_id policy_id;
+               u_int32_t route_rule_id;
+
+               /*
+                * We need a route to perform NECP route rule checks
+                */
+               if (net_qos_policy_restricted != 0 &&
+                   ROUTE_UNUSABLE(&inp->inp_route)) {
+                       struct sockaddr_in to;
+                       struct sockaddr_in from;
+
+                       ROUTE_RELEASE(&inp->inp_route);
+
+                       bzero(&from, sizeof(struct sockaddr_in));
+                       from.sin_family = AF_INET;
+                       from.sin_len = sizeof(struct sockaddr_in);
+                       from.sin_addr = laddr;
+
+                       bzero(&to, sizeof(struct sockaddr_in));
+                       to.sin_family = AF_INET;
+                       to.sin_len = sizeof(struct sockaddr_in);
+                       to.sin_addr = faddr;
+
+                       inp->inp_route.ro_dst.sa_family = AF_INET;
+                       inp->inp_route.ro_dst.sa_len = sizeof(struct sockaddr_in);
+                       ((struct sockaddr_in *)(void *)&inp->inp_route.ro_dst)->sin_addr =
+                               faddr;
+
+                       rtalloc_scoped(&inp->inp_route, ipoa.ipoa_boundif);
+
+                       inp_update_necp_policy(inp, (struct sockaddr *)&from,
+                           (struct sockaddr *)&to, ipoa.ipoa_boundif);
+                       inp->inp_policyresult.results.qos_marking_gencount = 0;
+               }
+
+               if (!necp_socket_is_allowed_to_send_recv_v4(inp, lport, fport,
+                   &laddr, &faddr, NULL, &policy_id, &route_rule_id)) {
+                       error = EHOSTUNREACH;
+                       goto abort;
+               }
+
+               necp_mark_packet_from_socket(m, inp, policy_id, route_rule_id);
+
+               if (net_qos_policy_restricted != 0) {
+                       necp_socket_update_qos_marking(inp,
+                           inp->inp_route.ro_rt, NULL, route_rule_id);
+               }
+       }
+#endif /* NECP */
+       if ((so->so_flags1 & SOF1_QOSMARKING_ALLOWED))
+               ipoa.ipoa_flags |= IPOAF_QOSMARKING_ALLOWED;
 
 #if IPSEC
-       if (ipsec_bypass == 0 && ipsec_setsocket(m, inp->inp_socket) != 0) {
+       if (inp->inp_sp != NULL && ipsec_setsocket(m, inp->inp_socket) != 0) {
                error = ENOBUFS;
                goto abort;
        }
-#endif /*IPSEC*/
-       m->m_pkthdr.socket_id = get_socket_id(inp->inp_socket);
+#endif /* IPSEC */
 
        inpopts = inp->inp_options;
-       soopts = (inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST));
+       soopts |= (inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST));
        mopts = inp->inp_moptions;
-
-       /* We don't want to cache the route for non-connected UDP */
-       if (udp_dodisconnect) {
-               bcopy(&inp->inp_route, &ro, sizeof (ro));
-               ro.ro_rt = NULL;
+       if (mopts != NULL) {
+               IMO_LOCK(mopts);
+               IMO_ADDREF_LOCKED(mopts);
+               if (IN_MULTICAST(ntohl(ui->ui_dst.s_addr)) &&
+                   mopts->imo_multicast_ifp != NULL) {
+                       /* no reference needed */
+                       inp->inp_last_outifp = mopts->imo_multicast_ifp;
+               }
+               IMO_UNLOCK(mopts);
        }
 
+       /* Copy the cached route and take an extra reference */
+       inp_route_copyout(inp, &ro);
+
+       set_packet_service_class(m, so, sotc, 0);
+       m->m_pkthdr.pkt_flowsrc = FLOWSRC_INPCB;
+       m->m_pkthdr.pkt_flowid = inp->inp_flowhash;
+       m->m_pkthdr.pkt_proto = IPPROTO_UDP;
+       m->m_pkthdr.pkt_flags |= (PKTF_FLOW_ID | PKTF_FLOW_LOCALSRC);
+       if (flowadv)
+               m->m_pkthdr.pkt_flags |= PKTF_FLOW_ADV;
+
+       if (ipoa.ipoa_boundif != IFSCOPE_NONE)
+               ipoa.ipoa_flags |= IPOAF_BOUND_IF;
+
+       if (laddr.s_addr != INADDR_ANY)
+               ipoa.ipoa_flags |= IPOAF_BOUND_SRCADDR;
+
+       inp->inp_sndinprog_cnt++;
+
        socket_unlock(so, 0);
-       /* XXX jgraessley please look at XXX */
-       error = ip_output_list(m, 0, inpopts,
-           udp_dodisconnect ? &ro : &inp->inp_route, soopts, mopts, NULL);
+       error = ip_output(m, inpopts, &ro, soopts, mopts, &ipoa);
+       m = NULL;
        socket_lock(so, 0);
+       if (mopts != NULL)
+               IMO_REMREF(mopts);
+
+       if (error == 0 && nstat_collect) {
+               boolean_t cell, wifi, wired;
+
+               if (ro.ro_rt != NULL) {
+                       cell = IFNET_IS_CELLULAR(ro.ro_rt->rt_ifp);
+                       wifi = (!cell && IFNET_IS_WIFI(ro.ro_rt->rt_ifp));
+                       wired = (!wifi && IFNET_IS_WIRED(ro.ro_rt->rt_ifp));
+               } else {
+                       cell = wifi = wired = FALSE;
+               }
+               INP_ADD_STAT(inp, cell, wifi, wired, txpackets, 1);
+               INP_ADD_STAT(inp, cell, wifi, wired, txbytes, len);
+       }
+
+       if (flowadv && (adv->code == FADV_FLOW_CONTROLLED ||
+           adv->code == FADV_SUSPENDED)) {
+               /*
+                * return a hint to the application that
+                * the packet has been dropped
+                */
+               error = ENOBUFS;
+               inp_set_fc_state(inp, adv->code);
+       }
 
+       VERIFY(inp->inp_sndinprog_cnt > 0);
+       if ( --inp->inp_sndinprog_cnt == 0)
+               inp->inp_flags &= ~(INP_FC_FEEDBACK);
+
+       /* Synchronize PCB cached route */
+       inp_route_copyin(inp, &ro);
+
+abort:
        if (udp_dodisconnect) {
-               /* Discard the cached route, if there is one */
-               if (ro.ro_rt != NULL)
-                       rtfree(ro.ro_rt);
+               /* Always discard the cached route for unconnected socket */
+               ROUTE_RELEASE(&inp->inp_route);
                in_pcbdisconnect(inp);
                inp->inp_laddr = origladdr;     /* XXX rehash? */
+               /* no reference needed */
+               inp->inp_last_outifp = origoutifp;
+       } else if (inp->inp_route.ro_rt != NULL) {
+               struct rtentry *rt = inp->inp_route.ro_rt;
+               struct ifnet *outifp;
+
+               if (rt->rt_flags & (RTF_MULTICAST|RTF_BROADCAST))
+                       rt = NULL;      /* unusable */
+               /*
+                * Always discard if it is a multicast or broadcast route.
+                */
+               if (rt == NULL)
+                       ROUTE_RELEASE(&inp->inp_route);
+
+               /*
+                * If the destination route is unicast, update outifp with
+                * that of the route interface used by IP.
+                */
+               if (rt != NULL &&
+                   (outifp = rt->rt_ifp) != inp->inp_last_outifp) {
+                       inp->inp_last_outifp = outifp; /* no reference needed */
+
+                       so->so_pktheadroom = P2ROUNDUP(
+                           sizeof(struct udphdr) +
+                           sizeof(struct ip) +
+                           ifnet_hdrlen(outifp) +
+                           ifnet_packetpreamblelen(outifp),
+                           sizeof(u_int32_t));
+               }
+       } else {
+               ROUTE_RELEASE(&inp->inp_route);
        }
-       KERNEL_DEBUG(DBG_FNC_UDP_OUTPUT | DBG_FUNC_END, error, 0,0,0,0);
-       return (error);
 
-abort:
-        if (udp_dodisconnect) {
-                in_pcbdisconnect(inp);
-                inp->inp_laddr = origladdr; /* XXX rehash? */
-        }
+       /*
+        * If output interface was cellular/expensive, and this socket is
+        * denied access to it, generate an event.
+        */
+       if (error != 0 && (ipoa.ipoa_retflags & IPOARF_IFDENIED) &&
+           (INP_NO_CELLULAR(inp) || INP_NO_EXPENSIVE(inp)))
+               soevent(so, (SO_FILT_HINT_LOCKED|SO_FILT_HINT_IFDENIED));
 
 release:
-       m_freem(m);
-       KERNEL_DEBUG(DBG_FNC_UDP_OUTPUT | DBG_FUNC_END, error, 0,0,0,0);
+       KERNEL_DEBUG(DBG_FNC_UDP_OUTPUT | DBG_FUNC_END, error, 0, 0, 0, 0);
+
+       if (m != NULL)
+               m_freem(m);
+
+       if (outif != NULL)
+               ifnet_release(outif);
+
        return (error);
 }
 
-u_long udp_sendspace = 9216;           /* really max datagram size */
-                                       /* 40 1K datagrams */
-SYSCTL_INT(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
-    &udp_sendspace, 0, "Maximum outgoing UDP datagram size");
-
-u_long udp_recvspace = 40 * (1024 +
+u_int32_t      udp_sendspace = 9216;           /* really max datagram size */
+/* 187 1K datagrams (approx 192 KB) */
+u_int32_t      udp_recvspace = 187 * (1024 +
 #if INET6
-                                     sizeof(struct sockaddr_in6)
-#else
-                                     sizeof(struct sockaddr_in)
-#endif
-                                     );
-SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
-    &udp_recvspace, 0, "Maximum incoming UDP datagram size");
+                   sizeof (struct sockaddr_in6)
+#else /* !INET6 */
+                   sizeof (struct sockaddr_in)
+#endif /* !INET6 */
+               );
+
+/* Check that the values of udp send and recv space do not exceed sb_max */
+static int
+sysctl_udp_sospace(struct sysctl_oid *oidp, void *arg1, int arg2,
+    struct sysctl_req *req)
+{
+#pragma unused(arg1, arg2)
+       u_int32_t new_value = 0, *space_p = NULL;
+       int changed = 0, error = 0;
+       u_quad_t sb_effective_max = (sb_max/(MSIZE+MCLBYTES)) * MCLBYTES;
+
+       switch (oidp->oid_number) {
+       case UDPCTL_RECVSPACE:
+               space_p = &udp_recvspace;
+               break;
+       case UDPCTL_MAXDGRAM:
+               space_p = &udp_sendspace;
+               break;
+       default:
+               return (EINVAL);
+       }
+       error = sysctl_io_number(req, *space_p, sizeof (u_int32_t),
+           &new_value, &changed);
+       if (changed) {
+               if (new_value > 0 && new_value <= sb_effective_max)
+                       *space_p = new_value;
+               else
+                       error = ERANGE;
+       }
+       return (error);
+}
+
+SYSCTL_PROC(_net_inet_udp, UDPCTL_RECVSPACE, recvspace,
+       CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &udp_recvspace, 0,
+       &sysctl_udp_sospace, "IU", "Maximum incoming UDP datagram size");
+
+SYSCTL_PROC(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram,
+       CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, &udp_sendspace, 0,
+       &sysctl_udp_sospace, "IU", "Maximum outgoing UDP datagram size");
 
 static int
 udp_abort(struct socket *so)
@@ -1213,33 +1910,39 @@ udp_abort(struct socket *so)
        struct inpcb *inp;
 
        inp = sotoinpcb(so);
-       if (inp == 0)
-               panic("udp_abort: so=%p null inp\n", so);       /* ??? possible? panic instead? */
+       if (inp == NULL) {
+               panic("%s: so=%p null inp\n", __func__, so);
+               /* NOTREACHED */
+       }
        soisdisconnected(so);
        in_pcbdetach(inp);
-       return 0;
+       return (0);
 }
 
 static int
-udp_attach(struct socket *so, __unused int proto, struct proc *p)
+udp_attach(struct socket *so, int proto, struct proc *p)
 {
+#pragma unused(proto)
        struct inpcb *inp;
        int error;
 
        inp = sotoinpcb(so);
-       if (inp != 0)
-               panic ("udp_attach so=%p inp=%p\n", so, inp);
-
+       if (inp != NULL) {
+               panic("%s so=%p inp=%p\n", __func__, so, inp);
+               /* NOTREACHED */
+       }
        error = in_pcballoc(so, &udbinfo, p);
-       if (error)
-               return error;
+       if (error != 0)
+               return (error);
        error = soreserve(so, udp_sendspace, udp_recvspace);
-       if (error
-               return error;
+       if (error != 0)
+               return (error);
        inp = (struct inpcb *)so->so_pcb;
        inp->inp_vflag |= INP_IPV4;
        inp->inp_ip_ttl = ip_defttl;
-       return 0;
+       if (nstat_collect)
+               nstat_udp_new_pcb(inp);
+       return (0);
 }
 
 static int
@@ -1248,15 +1951,15 @@ udp_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
        struct inpcb *inp;
        int error;
 
-       if (nam->sa_family != 0 && nam->sa_family != AF_INET
-           && nam->sa_family != AF_INET6) {
-               return EAFNOSUPPORT;
-       }
+       if (nam->sa_family != 0 && nam->sa_family != AF_INET &&
+           nam->sa_family != AF_INET6)
+               return (EAFNOSUPPORT);
+
        inp = sotoinpcb(so);
-       if (inp == 0)
-               return EINVAL;
+       if (inp == NULL)
+               return (EINVAL);
        error = in_pcbbind(inp, nam, p);
-       return error;
+       return (error);
 }
 
 static int
@@ -1266,14 +1969,129 @@ udp_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
        int error;
 
        inp = sotoinpcb(so);
-       if (inp == 0)
-               return EINVAL;
+       if (inp == NULL)
+               return (EINVAL);
        if (inp->inp_faddr.s_addr != INADDR_ANY)
-               return EISCONN;
-       error = in_pcbconnect(inp, nam, p);
-       if (error == 0) 
+               return (EISCONN);
+
+#if NECP
+#if FLOW_DIVERT
+       if (necp_socket_should_use_flow_divert(inp)) {
+               uint32_t fd_ctl_unit =
+                   necp_socket_get_flow_divert_control_unit(inp);
+               if (fd_ctl_unit > 0) {
+                       error = flow_divert_pcb_init(so, fd_ctl_unit);
+                       if (error == 0) {
+                               error = flow_divert_connect_out(so, nam, p);
+                       }
+               } else {
+                       error = ENETDOWN;
+               }
+               return (error);
+       }
+#endif /* FLOW_DIVERT */
+#endif /* NECP */
+
+       error = in_pcbconnect(inp, nam, p, IFSCOPE_NONE, NULL);
+       if (error == 0) {
                soisconnected(so);
-       return error;
+               if (inp->inp_flowhash == 0)
+                       inp->inp_flowhash = inp_calc_flowhash(inp);
+       }
+       return (error);
+}
+
+int
+udp_connectx_common(struct socket *so, int af, 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,
+    struct uio *uio, user_ssize_t *bytes_written)
+{
+#pragma unused(aid, flags, arg, arglen)
+       struct inpcb *inp = sotoinpcb(so);
+       int error;
+       user_ssize_t datalen = 0;
+
+       if (inp == NULL)
+               return (EINVAL);
+
+       VERIFY(dst != NULL);
+
+#if NECP
+       inp_update_necp_policy(inp, src, dst, ifscope);
+#endif /* NECP */
+
+       /* bind socket to the specified interface, if requested */
+       if (ifscope != IFSCOPE_NONE &&
+           (error = inp_bindif(inp, ifscope, NULL)) != 0)
+               return (error);
+
+       /* if source address and/or port is specified, bind to it */
+       if (src != NULL) {
+               error = sobindlock(so, src, 0); /* already locked */
+               if (error != 0)
+                       return (error);
+       }
+
+       switch (af) {
+       case AF_INET:
+               error = udp_connect(so, dst, p);
+               break;
+#if INET6
+       case AF_INET6:
+               error = udp6_connect(so, dst, p);
+               break;
+#endif /* INET6 */
+       default:
+               VERIFY(0);
+               /* NOTREACHED */
+       }
+
+       if (error != 0)
+               return (error);
+
+       /*
+        * If there is data, copy it. DATA_IDEMPOTENT is ignored.
+        * CONNECT_RESUME_ON_READ_WRITE is ignored.
+        */
+       if (uio != NULL) {
+               socket_unlock(so, 0);
+
+               VERIFY(bytes_written != NULL);
+
+               datalen = uio_resid(uio);
+               error = so->so_proto->pr_usrreqs->pru_sosend(so, NULL,
+                   (uio_t)uio, NULL, NULL, 0);
+               socket_lock(so, 0);
+
+               /* If error returned is EMSGSIZE, for example, disconnect */
+               if (error == 0 || error == EWOULDBLOCK)
+                       *bytes_written = datalen - uio_resid(uio);
+               else
+                       (void) so->so_proto->pr_usrreqs->pru_disconnectx(so,
+                           SAE_ASSOCID_ANY, SAE_CONNID_ANY);
+               /*
+                * mask the EWOULDBLOCK error so that the caller
+                * knows that atleast the connect was successful.
+                */
+               if (error == EWOULDBLOCK)
+                       error = 0;
+       }
+
+       if (error == 0 && pcid != NULL)
+               *pcid = 1;      /* there is only 1 connection for UDP */
+
+       return (error);
+}
+
+static int
+udp_connectx(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, struct uio *uio, user_ssize_t *bytes_written)
+{
+       return (udp_connectx_common(so, AF_INET, src, dst,
+           p, ifscope, aid, pcid, flags, arg, arglen, uio, bytes_written));
 }
 
 static int
@@ -1282,11 +2100,23 @@ udp_detach(struct socket *so)
        struct inpcb *inp;
 
        inp = sotoinpcb(so);
-       if (inp == 0)
-               panic("udp_detach: so=%p null inp\n", so);      /* ??? possible? panic instead? */
+       if (inp == NULL) {
+               panic("%s: so=%p null inp\n", __func__, so);
+               /* NOTREACHED */
+       }
+
+       /*
+        * If this is a socket that does not want to wakeup the device
+        * for it's traffic, the application might be waiting for
+        * close to complete before going to sleep. Send a notification
+        * for this kind of sockets
+        */
+       if (so->so_options & SO_NOWAKEFROMSLEEP)
+               socket_post_kev_msg_closed(so);
+
        in_pcbdetach(inp);
        inp->inp_state = INPCB_STATE_DEAD;
-       return 0;
+       return (0);
 }
 
 static int
@@ -1295,29 +2125,65 @@ udp_disconnect(struct socket *so)
        struct inpcb *inp;
 
        inp = sotoinpcb(so);
-       if (inp == 0)
-               return EINVAL;
+       if (inp == NULL
+#if NECP
+               || (necp_socket_should_use_flow_divert(inp))
+#endif /* NECP */
+               )
+               return (inp == NULL ? EINVAL : EPROTOTYPE);
        if (inp->inp_faddr.s_addr == INADDR_ANY)
-               return ENOTCONN;
+               return (ENOTCONN);
 
        in_pcbdisconnect(inp);
+
+       /* reset flow controlled state, just in case */
+       inp_reset_fc_state(inp);
+
        inp->inp_laddr.s_addr = INADDR_ANY;
        so->so_state &= ~SS_ISCONNECTED;                /* XXX */
-       return 0;
+       inp->inp_last_outifp = NULL;
+       return (0);
 }
 
 static int
-udp_send(struct socket *so, __unused int flags, struct mbuf *m, struct sockaddr *addr,
-           struct mbuf *control, struct proc *p)
+udp_disconnectx(struct socket *so, sae_associd_t aid, sae_connid_t cid)
 {
+#pragma unused(cid)
+       if (aid != SAE_ASSOCID_ANY && aid != SAE_ASSOCID_ALL)
+               return (EINVAL);
+
+       return (udp_disconnect(so));
+}
+
+static int
+udp_send(struct socket *so, int flags, struct mbuf *m,
+    struct sockaddr *addr, struct mbuf *control, struct proc *p)
+{
+#ifndef FLOW_DIVERT
+#pragma unused(flags)
+#endif /* !(FLOW_DIVERT) */
        struct inpcb *inp;
 
        inp = sotoinpcb(so);
-       if (inp == 0) {
-               m_freem(m);
-               return EINVAL;
+       if (inp == NULL) {
+               if (m != NULL)
+                       m_freem(m);
+               if (control != NULL)
+                       m_freem(control);
+               return (EINVAL);
        }
-       return udp_output(inp, m, addr, control, p);
+
+#if NECP
+#if FLOW_DIVERT
+       if (necp_socket_should_use_flow_divert(inp)) {
+               /* Implicit connect */
+               return (flow_divert_implicit_data_out(so, flags, m, addr,
+                   control, p));
+       }
+#endif /* FLOW_DIVERT */
+#endif /* NECP */
+
+       return (udp_output(inp, m, addr, control, p));
 }
 
 int
@@ -1326,156 +2192,512 @@ udp_shutdown(struct socket *so)
        struct inpcb *inp;
 
        inp = sotoinpcb(so);
-       if (inp == 0)
-               return EINVAL;
+       if (inp == NULL)
+               return (EINVAL);
        socantsendmore(so);
-       return 0;
+       return (0);
 }
 
-struct pr_usrreqs udp_usrreqs = {
-       udp_abort, pru_accept_notsupp, udp_attach, udp_bind, udp_connect, 
-       pru_connect2_notsupp, in_control, udp_detach, udp_disconnect, 
-       pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp, 
-       pru_rcvoob_notsupp, udp_send, pru_sense_null, udp_shutdown,
-       in_setsockaddr, sosend, soreceive, pru_sopoll_notsupp
-};
-
-
 int
-udp_lock(struct socket *so, int refcount, int debug)
+udp_lock(struct socket *so, int refcount, void *debug)
 {
-       int lr_saved;
-       if (debug == 0) 
-               lr_saved = (unsigned int) __builtin_return_address(0);
-       else lr_saved = debug;
+       void *lr_saved;
 
-       if (so->so_pcb) {
-               lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_NOTOWNED);
-               lck_mtx_lock(((struct inpcb *)so->so_pcb)->inpcb_mtx);
-       }
-       else 
-               panic("udp_lock: so=%p NO PCB! lr=%x\n", so, lr_saved);
+       if (debug == NULL)
+               lr_saved = __builtin_return_address(0);
+       else
+               lr_saved = debug;
 
-       if (refcount) 
+       if (so->so_pcb != NULL) {
+               lck_mtx_assert(&((struct inpcb *)so->so_pcb)->inpcb_mtx,
+                   LCK_MTX_ASSERT_NOTOWNED);
+               lck_mtx_lock(&((struct inpcb *)so->so_pcb)->inpcb_mtx);
+       } else {
+               panic("%s: so=%p NO PCB! lr=%p lrh= %s\n", __func__,
+                   so, lr_saved, solockhistory_nr(so));
+               /* NOTREACHED */
+       }
+       if (refcount)
                so->so_usecount++;
 
-       so->lock_lr[so->next_lock_lr] = (u_int32_t)lr_saved;
+       so->lock_lr[so->next_lock_lr] = lr_saved;
        so->next_lock_lr = (so->next_lock_lr+1) % SO_LCKDBG_MAX;
        return (0);
 }
 
 int
-udp_unlock(struct socket *so, int refcount, int debug)
+udp_unlock(struct socket *so, int refcount, void *debug)
 {
-       int lr_saved;
+       void *lr_saved;
 
-       if (debug == 0) 
-               lr_saved = (unsigned int) __builtin_return_address(0);
-       else lr_saved = debug;
+       if (debug == NULL)
+               lr_saved = __builtin_return_address(0);
+       else
+               lr_saved = debug;
 
        if (refcount) {
+               VERIFY(so->so_usecount > 0);
                so->so_usecount--;
-#if 0
-               {
-                       struct inpcb *inp = sotoinpcb(so);
-                   struct inpcbinfo *pcbinfo   = &udbinfo;
-                   
-                       if (so->so_usecount == 0 && (inp->inp_wantcnt == WNT_STOPUSING)) {
-                               
-                               if (lck_rw_try_lock_exclusive(pcbinfo->mtx)) {
-                                       in_pcbdispose(inp);
-                                       lck_rw_done(pcbinfo->mtx);
-                                       return(0);
-                               }
-                       }
-               }
-#endif
        }
-       if (so->so_pcb == NULL) 
-               panic("udp_unlock: so=%p NO PCB! lr=%x\n", so, lr_saved);
-       else {
-               lck_mtx_assert(((struct inpcb *)so->so_pcb)->inpcb_mtx, LCK_MTX_ASSERT_OWNED);
-               so->unlock_lr[so->next_unlock_lr] = (u_int32_t)lr_saved;
+       if (so->so_pcb == NULL) {
+               panic("%s: so=%p NO PCB! lr=%p lrh= %s\n", __func__,
+                   so, lr_saved, solockhistory_nr(so));
+               /* NOTREACHED */
+       } else {
+               lck_mtx_assert(&((struct inpcb *)so->so_pcb)->inpcb_mtx,
+                   LCK_MTX_ASSERT_OWNED);
+               so->unlock_lr[so->next_unlock_lr] = lr_saved;
                so->next_unlock_lr = (so->next_unlock_lr+1) % SO_LCKDBG_MAX;
-               lck_mtx_unlock(((struct inpcb *)so->so_pcb)->inpcb_mtx);
+               lck_mtx_unlock(&((struct inpcb *)so->so_pcb)->inpcb_mtx);
        }
-
-
        return (0);
 }
 
 lck_mtx_t *
-udp_getlock(struct socket *so, __unused int locktype)
+udp_getlock(struct socket *so, int locktype)
 {
+#pragma unused(locktype)
        struct inpcb *inp = sotoinpcb(so);
 
-
-       if (so->so_pcb)
-               return(inp->inpcb_mtx);
-       else {
-               panic("udp_getlock: so=%p NULL so_pcb\n", so);
-               return (so->so_proto->pr_domain->dom_mtx);
+       if (so->so_pcb == NULL) {
+               panic("%s: so=%p NULL so_pcb lrh= %s\n", __func__,
+                   so, solockhistory_nr(so));
+               /* NOTREACHED */
        }
+       return (&inp->inpcb_mtx);
 }
 
-void
-udp_slowtimo()
+/*
+ * UDP garbage collector callback (inpcb_timer_func_t).
+ *
+ * Returns > 0 to keep timer active.
+ */
+static void
+udp_gc(struct inpcbinfo *ipi)
 {
        struct inpcb *inp, *inpnxt;
        struct socket *so;
-       struct inpcbinfo *pcbinfo       = &udbinfo;
 
-       if (lck_rw_try_lock_exclusive(pcbinfo->mtx) == FALSE) {
+       if (lck_rw_try_lock_exclusive(ipi->ipi_lock) == FALSE) {
                if (udp_gc_done == TRUE) {
                        udp_gc_done = FALSE;
-                       return; /* couldn't get the lock, better lock next time */
+                       /* couldn't get the lock, must lock next time */
+                       atomic_add_32(&ipi->ipi_gc_req.intimer_fast, 1);
+                       return;
                }
-               lck_rw_lock_exclusive(pcbinfo->mtx);
+               lck_rw_lock_exclusive(ipi->ipi_lock);
        }
 
        udp_gc_done = TRUE;
 
        for (inp = udb.lh_first; inp != NULL; inp = inpnxt) {
                inpnxt = inp->inp_list.le_next;
-       
-               /* Ignore nat/SharedIP dummy pcbs */
-               if (inp->inp_socket == &udbinfo.nat_dummy_socket)
-                               continue;
 
-               if (inp->inp_wantcnt != WNT_STOPUSING) 
+               /*
+                * Skip unless it's STOPUSING; garbage collector will
+                * be triggered by in_pcb_checkstate() upon setting
+                * wantcnt to that value.  If the PCB is already dead,
+                * keep gc active to anticipate wantcnt changing.
+                */
+               if (inp->inp_wantcnt != WNT_STOPUSING)
                        continue;
 
-               so = inp->inp_socket;
-               if (!lck_mtx_try_lock(inp->inpcb_mtx))  /* skip if busy, no hurry for cleanup... */
+               /*
+                * Skip if busy, no hurry for cleanup.  Keep gc active
+                * and try the lock again during next round.
+                */
+               if (!lck_mtx_try_lock(&inp->inpcb_mtx)) {
+                       atomic_add_32(&ipi->ipi_gc_req.intimer_fast, 1);
                        continue;
+               }
 
-               if (so->so_usecount == 0)
+               /*
+                * Keep gc active unless usecount is 0.
+                */
+               so = inp->inp_socket;
+               if (so->so_usecount == 0) {
+                       if (inp->inp_state != INPCB_STATE_DEAD) {
+#if INET6
+                               if (SOCK_CHECK_DOM(so, PF_INET6))
+                                       in6_pcbdetach(inp);
+                               else
+#endif /* INET6 */
+                                       in_pcbdetach(inp);
+                       }
                        in_pcbdispose(inp);
-               else 
-                       lck_mtx_unlock(inp->inpcb_mtx);
+               } else {
+                       lck_mtx_unlock(&inp->inpcb_mtx);
+                       atomic_add_32(&ipi->ipi_gc_req.intimer_fast, 1);
+               }
        }
-       lck_rw_done(pcbinfo->mtx);
+       lck_rw_done(ipi->ipi_lock);
 }
 
-int
-ChkAddressOK( __uint32_t dstaddr, __uint32_t srcaddr )
+static int
+udp_getstat SYSCTL_HANDLER_ARGS
 {
-        if ( dstaddr == srcaddr ){
-                return 0;
-        }
-        return 1;
+#pragma unused(oidp, arg1, arg2)
+       if (req->oldptr == USER_ADDR_NULL)
+               req->oldlen = (size_t)sizeof (struct udpstat);
+
+       return (SYSCTL_OUT(req, &udpstat, MIN(sizeof (udpstat), req->oldlen)));
 }
 
 void
 udp_in_cksum_stats(u_int32_t len)
 {
-       udps_in_sw_cksum++;
-       udps_in_sw_cksum_bytes += len;
+       udpstat.udps_rcv_swcsum++;
+       udpstat.udps_rcv_swcsum_bytes += len;
 }
 
 void
 udp_out_cksum_stats(u_int32_t len)
 {
-       udps_out_sw_cksum++;
-       udps_out_sw_cksum_bytes += len;
+       udpstat.udps_snd_swcsum++;
+       udpstat.udps_snd_swcsum_bytes += len;
+}
+
+#if INET6
+void
+udp_in6_cksum_stats(u_int32_t len)
+{
+       udpstat.udps_rcv6_swcsum++;
+       udpstat.udps_rcv6_swcsum_bytes += len;
+}
+
+void
+udp_out6_cksum_stats(u_int32_t len)
+{
+       udpstat.udps_snd6_swcsum++;
+       udpstat.udps_snd6_swcsum_bytes += len;
+}
+#endif /* INET6 */
+
+/*
+ * Checksum extended UDP header and data.
+ */
+static int
+udp_input_checksum(struct mbuf *m, struct udphdr *uh, int off, int ulen)
+{
+       struct ifnet *ifp = m->m_pkthdr.rcvif;
+       struct ip *ip = mtod(m, struct ip *);
+       struct ipovly *ipov = (struct ipovly *)ip;
+
+       if (uh->uh_sum == 0) {
+               udpstat.udps_nosum++;
+               return (0);
+       }
+
+       if ((hwcksum_rx || (ifp->if_flags & IFF_LOOPBACK) ||
+           (m->m_pkthdr.pkt_flags & PKTF_LOOP)) &&
+           (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)) {
+               if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) {
+                       uh->uh_sum = m->m_pkthdr.csum_rx_val;
+               } else {
+                       uint16_t sum = m->m_pkthdr.csum_rx_val;
+                       uint16_t start = m->m_pkthdr.csum_rx_start;
+
+                       /*
+                        * Perform 1's complement adjustment of octets
+                        * that got included/excluded in the hardware-
+                        * calculated checksum value.  Ignore cases
+                        * where the value includes or excludes the
+                        * IP header span, as the sum for those octets
+                        * would already be 0xffff and thus no-op.
+                        */
+                       if ((m->m_pkthdr.csum_flags & CSUM_PARTIAL) &&
+                           start != 0 && (off - start) != off) {
+#if BYTE_ORDER != BIG_ENDIAN
+                               if (start < off) {
+                                       HTONS(ip->ip_len);
+                                       HTONS(ip->ip_off);
+                               }
+#endif /* BYTE_ORDER != BIG_ENDIAN */
+                               /* callee folds in sum */
+                               sum = m_adj_sum16(m, start, off, sum);
+#if BYTE_ORDER != BIG_ENDIAN
+                               if (start < off) {
+                                       NTOHS(ip->ip_off);
+                                       NTOHS(ip->ip_len);
+                               }
+#endif /* BYTE_ORDER != BIG_ENDIAN */
+                       }
+
+                       /* callee folds in sum */
+                       uh->uh_sum = in_pseudo(ip->ip_src.s_addr,
+                           ip->ip_dst.s_addr, sum + htonl(ulen + IPPROTO_UDP));
+               }
+               uh->uh_sum ^= 0xffff;
+       } else {
+               uint16_t ip_sum;
+               char b[9];
+
+               bcopy(ipov->ih_x1, b, sizeof (ipov->ih_x1));
+               bzero(ipov->ih_x1, sizeof (ipov->ih_x1));
+               ip_sum = ipov->ih_len;
+               ipov->ih_len = uh->uh_ulen;
+               uh->uh_sum = in_cksum(m, ulen + sizeof (struct ip));
+               bcopy(b, ipov->ih_x1, sizeof (ipov->ih_x1));
+               ipov->ih_len = ip_sum;
+
+               udp_in_cksum_stats(ulen);
+       }
+
+       if (uh->uh_sum != 0) {
+               udpstat.udps_badsum++;
+               IF_UDP_STATINC(ifp, badchksum);
+               return (-1);
+       }
+
+       return (0);
+}
+
+void
+udp_fill_keepalive_offload_frames(ifnet_t ifp,
+    struct ifnet_keepalive_offload_frame *frames_array,
+    u_int32_t frames_array_count, size_t frame_data_offset,
+    u_int32_t *used_frames_count)
+{
+       struct inpcb *inp;
+       inp_gen_t gencnt;
+       u_int32_t frame_index = *used_frames_count;
+
+       if (ifp == NULL || frames_array == NULL ||
+           frames_array_count == 0 ||
+           frame_index >= frames_array_count ||
+           frame_data_offset >= IFNET_KEEPALIVE_OFFLOAD_FRAME_DATA_SIZE)
+               return;
+
+       lck_rw_lock_shared(udbinfo.ipi_lock);
+       gencnt = udbinfo.ipi_gencnt;
+       LIST_FOREACH(inp, udbinfo.ipi_listhead, inp_list) {
+               struct socket *so;
+               u_int8_t *data;
+               struct ifnet_keepalive_offload_frame *frame;
+               struct mbuf *m = NULL;
+
+               if (frame_index >= frames_array_count)
+                       break;
+
+               if (inp->inp_gencnt > gencnt ||
+                   inp->inp_state == INPCB_STATE_DEAD)
+                       continue;
+
+               if ((so = inp->inp_socket) == NULL ||
+                   (so->so_state & SS_DEFUNCT))
+                       continue;
+               /*
+                * check for keepalive offload flag without socket
+                * lock to avoid a deadlock
+                */
+               if (!(inp->inp_flags2 & INP2_KEEPALIVE_OFFLOAD)) {
+                       continue;
+               }
+
+               udp_lock(so, 1, 0);
+               if (!(inp->inp_vflag & (INP_IPV4 | INP_IPV6))) {
+                       udp_unlock(so, 1, 0);
+                       continue;
+               }
+               if ((inp->inp_vflag & INP_IPV4) &&
+                   (inp->inp_laddr.s_addr == INADDR_ANY ||
+                   inp->inp_faddr.s_addr == INADDR_ANY)) {
+                       udp_unlock(so, 1, 0);
+                       continue;
+               }
+               if ((inp->inp_vflag & INP_IPV6) &&
+                   (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) ||
+                   IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))) {
+                       udp_unlock(so, 1, 0);
+                       continue;
+               }
+               if (inp->inp_lport == 0 || inp->inp_fport == 0) {
+                       udp_unlock(so, 1, 0);
+                       continue;
+               }
+               if (inp->inp_last_outifp == NULL ||
+                   inp->inp_last_outifp->if_index != ifp->if_index) {
+                       udp_unlock(so, 1, 0);
+                       continue;
+               }
+               if ((inp->inp_vflag & INP_IPV4)) {
+                       if ((frame_data_offset + sizeof(struct udpiphdr) +
+                           inp->inp_keepalive_datalen) >
+                           IFNET_KEEPALIVE_OFFLOAD_FRAME_DATA_SIZE) {
+                               udp_unlock(so, 1, 0);
+                               continue;
+                       }
+                       if ((sizeof(struct udpiphdr) +
+                           inp->inp_keepalive_datalen) > _MHLEN) {
+                               udp_unlock(so, 1, 0);
+                               continue;
+                       }
+               } else {
+                       if ((frame_data_offset + sizeof(struct ip6_hdr) +
+                           sizeof(struct udphdr) +
+                           inp->inp_keepalive_datalen) >
+                           IFNET_KEEPALIVE_OFFLOAD_FRAME_DATA_SIZE) {
+                               udp_unlock(so, 1, 0);
+                               continue;
+                       }
+                       if ((sizeof(struct ip6_hdr) + sizeof(struct udphdr) +
+                           inp->inp_keepalive_datalen) > _MHLEN) {
+                               udp_unlock(so, 1, 0);
+                               continue;
+                       }
+               }
+               MGETHDR(m, M_WAIT, MT_HEADER);
+               if (m == NULL) {
+                       udp_unlock(so, 1, 0);
+                       continue;
+               }
+               /*
+                * This inp has all the information that is needed to
+                * generate an offload frame.
+                */
+               if (inp->inp_vflag & INP_IPV4) {
+                       struct ip *ip;
+                       struct udphdr *udp;
+
+                       frame = &frames_array[frame_index];
+                       frame->length = frame_data_offset +
+                           sizeof(struct udpiphdr) +
+                           inp->inp_keepalive_datalen;
+                       frame->ether_type =
+                           IFNET_KEEPALIVE_OFFLOAD_FRAME_ETHERTYPE_IPV4;
+                       frame->interval = inp->inp_keepalive_interval;
+                       switch (inp->inp_keepalive_type) {
+                       case UDP_KEEPALIVE_OFFLOAD_TYPE_AIRPLAY:
+                               frame->type =
+                                   IFNET_KEEPALIVE_OFFLOAD_FRAME_AIRPLAY;
+                               break;
+                       default:
+                               break;
+                       }
+                       data = mtod(m, u_int8_t *);
+                       bzero(data, sizeof(struct udpiphdr));
+                       ip = (__typeof__(ip))(void *)data;
+                       udp = (__typeof__(udp))(void *) (data +
+                           sizeof(struct ip));
+                       m->m_len = sizeof(struct udpiphdr);
+                       data = data + sizeof(struct udpiphdr);
+                       if (inp->inp_keepalive_datalen > 0 &&
+                           inp->inp_keepalive_data != NULL) {
+                               bcopy(inp->inp_keepalive_data, data,
+                                   inp->inp_keepalive_datalen);
+                               m->m_len += inp->inp_keepalive_datalen;
+                       }
+                       m->m_pkthdr.len = m->m_len;
+
+                       ip->ip_v = IPVERSION;
+                       ip->ip_hl = (sizeof(struct ip) >> 2);
+                       ip->ip_p = IPPROTO_UDP;
+                       ip->ip_len = htons(sizeof(struct udpiphdr) +
+                           (u_short)inp->inp_keepalive_datalen);
+                       ip->ip_ttl = inp->inp_ip_ttl;
+                       ip->ip_tos |= (inp->inp_ip_tos & ~IPTOS_ECN_MASK);
+                       ip->ip_src = inp->inp_laddr;
+                       ip->ip_dst = inp->inp_faddr;
+                       ip->ip_sum = in_cksum_hdr_opt(ip);
+
+                       udp->uh_sport = inp->inp_lport;
+                       udp->uh_dport = inp->inp_fport;
+                       udp->uh_ulen = htons(sizeof(struct udphdr) +
+                           (u_short)inp->inp_keepalive_datalen);
+
+                       if (!(inp->inp_flags & INP_UDP_NOCKSUM)) {
+                               udp->uh_sum = in_pseudo(ip->ip_src.s_addr,
+                                   ip->ip_dst.s_addr,
+                                   htons(sizeof(struct udphdr) +
+                                   (u_short)inp->inp_keepalive_datalen +
+                                   IPPROTO_UDP));
+                               m->m_pkthdr.csum_flags = CSUM_UDP;
+                               m->m_pkthdr.csum_data = offsetof(struct udphdr,
+                                   uh_sum);
+                       }
+                       m->m_pkthdr.pkt_proto = IPPROTO_UDP;
+                       in_delayed_cksum(m);
+                       bcopy(m->m_data, frame->data + frame_data_offset,
+                           m->m_len);
+               } else {
+                       struct ip6_hdr *ip6;
+                       struct udphdr *udp6;
+
+                       VERIFY(inp->inp_vflag & INP_IPV6);
+                       frame = &frames_array[frame_index];
+                       frame->length = frame_data_offset +
+                           sizeof(struct ip6_hdr) +
+                           sizeof(struct udphdr) +
+                           inp->inp_keepalive_datalen;
+                       frame->ether_type =
+                           IFNET_KEEPALIVE_OFFLOAD_FRAME_ETHERTYPE_IPV6;
+                       frame->interval = inp->inp_keepalive_interval;
+                       switch (inp->inp_keepalive_type) {
+                       case UDP_KEEPALIVE_OFFLOAD_TYPE_AIRPLAY:
+                               frame->type =
+                                   IFNET_KEEPALIVE_OFFLOAD_FRAME_AIRPLAY;
+                               break;
+                       default:
+                               break;
+                       }
+                       data = mtod(m, u_int8_t *);
+                       bzero(data, sizeof(struct ip6_hdr) + sizeof(struct udphdr));
+                       ip6 = (__typeof__(ip6))(void *)data;
+                       udp6 = (__typeof__(udp6))(void *)(data +
+                           sizeof(struct ip6_hdr));
+                       m->m_len = sizeof(struct ip6_hdr) +
+                           sizeof(struct udphdr);
+                       data = data + (sizeof(struct ip6_hdr) +
+                           sizeof(struct udphdr));
+                       if (inp->inp_keepalive_datalen > 0 &&
+                           inp->inp_keepalive_data != NULL) {
+                               bcopy(inp->inp_keepalive_data, data,
+                                   inp->inp_keepalive_datalen);
+                               m->m_len += inp->inp_keepalive_datalen;
+                       }
+                       m->m_pkthdr.len = m->m_len;
+                       ip6->ip6_flow = inp->inp_flow & IPV6_FLOWINFO_MASK;
+                       ip6->ip6_flow = ip6->ip6_flow & ~IPV6_FLOW_ECN_MASK;
+                       ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
+                       ip6->ip6_vfc |= IPV6_VERSION;
+                       ip6->ip6_nxt = IPPROTO_UDP;
+                       ip6->ip6_hlim = ip6_defhlim;
+                       ip6->ip6_plen = htons(sizeof(struct udphdr) +
+                           (u_short)inp->inp_keepalive_datalen);
+                       ip6->ip6_src = inp->in6p_laddr;
+                       if (IN6_IS_SCOPE_EMBED(&ip6->ip6_src))
+                               ip6->ip6_src.s6_addr16[1] = 0;
+
+                       ip6->ip6_dst = inp->in6p_faddr;
+                       if (IN6_IS_SCOPE_EMBED(&ip6->ip6_dst))
+                               ip6->ip6_dst.s6_addr16[1] = 0;
+
+                       udp6->uh_sport = inp->in6p_lport;
+                       udp6->uh_dport = inp->in6p_fport;
+                       udp6->uh_ulen = htons(sizeof(struct udphdr) +
+                           (u_short)inp->inp_keepalive_datalen);
+                       if (!(inp->inp_flags & INP_UDP_NOCKSUM)) {
+                               udp6->uh_sum = in6_pseudo(&ip6->ip6_src,
+                                   &ip6->ip6_dst,
+                                   htonl(sizeof(struct udphdr) +
+                                   (u_short)inp->inp_keepalive_datalen +
+                                   IPPROTO_UDP));
+                               m->m_pkthdr.csum_flags = CSUM_UDPIPV6;
+                               m->m_pkthdr.csum_data = offsetof(struct udphdr,
+                                   uh_sum);
+                       }
+                       m->m_pkthdr.pkt_proto = IPPROTO_UDP;
+                       in6_delayed_cksum(m);
+                       bcopy(m->m_data, frame->data + frame_data_offset,
+                           m->m_len);
+               }
+               if (m != NULL) {
+                       m_freem(m);
+                       m = NULL;
+               }
+               frame_index++;
+               udp_unlock(so, 1, 0);
+       }
+       lck_rw_done(udbinfo.ipi_lock);
+       *used_frames_count = frame_index;
 }