]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/uipc_usrreq.c
xnu-6153.81.5.tar.gz
[apple/xnu.git] / bsd / kern / uipc_usrreq.c
index 9b568d24c65b22e5b8dadf849b64e5902ba2789e..2c4434dc2cc491f0f56809aa7d8a9783a241482c 100644 (file)
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 2000-2007 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2019 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@
  */
 /*
@@ -71,8 +71,9 @@
 #include <sys/kernel.h>
 #include <sys/domain.h>
 #include <sys/fcntl.h>
-#include <sys/malloc.h>                /* XXX must be before <sys/file.h> */
+#include <sys/malloc.h>         /* XXX must be before <sys/file.h> */
 #include <sys/file_internal.h>
+#include <sys/guarded.h>
 #include <sys/filedesc.h>
 #include <sys/lock.h>
 #include <sys/mbuf.h>
 #include <sys/unpcb.h>
 #include <sys/vnode_internal.h>
 #include <sys/kdebug.h>
+#include <sys/mcache.h>
 
 #include <kern/zalloc.h>
 #include <kern/locks.h>
 
-#if CONFIG_MACF_SOCKET
+#if CONFIG_MACF
 #include <security/mac_framework.h>
-#endif /* MAC_SOCKET */
+#endif /* CONFIG_MACF */
 
-#define        f_msgcount f_fglob->fg_msgcount
-#define        f_cred f_fglob->fg_cred
-#define        f_ops f_fglob->fg_ops
-#define        f_offset f_fglob->fg_offset
-#define        f_data f_fglob->fg_data
-struct zone *unp_zone;
-static unp_gen_t unp_gencnt;
-static u_int unp_count;
+#include <mach/vm_param.h>
 
-static lck_attr_t              *unp_mtx_attr;
-static lck_grp_t               *unp_mtx_grp;
-static lck_grp_attr_t          *unp_mtx_grp_attr;
-static lck_rw_t                *unp_list_mtx;
+/*
+ * Maximum number of FDs that can be passed in an mbuf
+ */
+#define UIPC_MAX_CMSG_FD        512
+
+#define f_msgcount f_fglob->fg_msgcount
+#define f_cred f_fglob->fg_cred
+#define f_ops f_fglob->fg_ops
+#define f_offset f_fglob->fg_offset
+#define f_data f_fglob->fg_data
+struct  zone *unp_zone;
+static  unp_gen_t unp_gencnt;
+static  u_int unp_count;
+
+static  lck_attr_t              *unp_mtx_attr;
+static  lck_grp_t               *unp_mtx_grp;
+static  lck_grp_attr_t          *unp_mtx_grp_attr;
+static  lck_rw_t                *unp_list_mtx;
+
+static  lck_mtx_t               *unp_disconnect_lock;
+static  lck_mtx_t               *unp_connect_lock;
+static  u_int                   disconnect_in_progress;
 
 extern lck_mtx_t *uipc_lock;
-static struct unp_head unp_shead, unp_dhead;
+static  struct unp_head unp_shead, unp_dhead;
+
+/*
+ * mDNSResponder tracing.  When enabled, endpoints connected to
+ * /var/run/mDNSResponder will be traced; during each send on
+ * the traced socket, we log the PID and process name of the
+ * sending process.  We also print out a bit of info related
+ * to the data itself; this assumes ipc_msg_hdr in dnssd_ipc.h
+ * of mDNSResponder stays the same.
+ */
+#define MDNSRESPONDER_PATH      "/var/run/mDNSResponder"
+
+static int unpst_tracemdns;     /* enable tracing */
+
+#define MDNS_IPC_MSG_HDR_VERSION_1      1
+
+struct mdns_ipc_msg_hdr {
+       uint32_t version;
+       uint32_t datalen;
+       uint32_t ipc_flags;
+       uint32_t op;
+       union {
+               void *context;
+               uint32_t u32[2];
+       } __attribute__((packed));
+       uint32_t reg_index;
+} __attribute__((packed));
 
 /*
  * Unix communications domain.
@@ -122,38 +161,59 @@ static    struct unp_head unp_shead, unp_dhead;
  *     need a proper out-of-band
  *     lock pushdown
  */
-static struct  sockaddr sun_noname = { sizeof (sun_noname), AF_LOCAL, { 0 } };
-static ino_t   unp_ino;                /* prototype for fake inode numbers */
-
-static int     unp_attach(struct socket *);
-static void    unp_detach(struct unpcb *);
-static int     unp_bind(struct unpcb *, struct sockaddr *, proc_t);
-static int     unp_connect(struct socket *, struct sockaddr *, proc_t);
-static void    unp_disconnect(struct unpcb *);
-static void    unp_shutdown(struct unpcb *);
-static void    unp_drop(struct unpcb *, int);
-static void    unp_gc(void);
-static void    unp_scan(struct mbuf *, void (*)(struct fileglob *));
-static void    unp_mark(struct fileglob *);
-static void    unp_discard(struct fileglob *);
-static void    unp_discard_fdlocked(struct fileglob *, proc_t);
-static int     unp_internalize(struct mbuf *, proc_t);
-static int     unp_listen(struct unpcb *, proc_t);
-
-/* TODO: this should be in header file */
-extern int fdgetf_noref(proc_t, int, struct fileproc **);
+static struct   sockaddr sun_noname = { .sa_len = sizeof(sun_noname), .sa_family = AF_LOCAL, .sa_data = { 0 } };
+static ino_t    unp_ino;                /* prototype for fake inode numbers */
+
+static int      unp_attach(struct socket *);
+static void     unp_detach(struct unpcb *);
+static int      unp_bind(struct unpcb *, struct sockaddr *, proc_t);
+static int      unp_connect(struct socket *, struct sockaddr *, proc_t);
+static void     unp_disconnect(struct unpcb *);
+static void     unp_shutdown(struct unpcb *);
+static void     unp_drop(struct unpcb *, int);
+__private_extern__ void unp_gc(void);
+static void     unp_scan(struct mbuf *, void (*)(struct fileglob *, void *arg), void *arg);
+static void     unp_mark(struct fileglob *, __unused void *);
+static void     unp_discard(struct fileglob *, void *);
+static int      unp_internalize(struct mbuf *, proc_t);
+static int      unp_listen(struct unpcb *, proc_t);
+static void     unpcb_to_compat(struct unpcb *, struct unpcb_compat *);
+static void     unp_get_locks_in_order(struct socket *so, struct socket *conn_so);
+
+static void
+unp_get_locks_in_order(struct socket *so, struct socket *conn_so)
+{
+       if (so < conn_so) {
+               socket_lock(conn_so, 1);
+       } else {
+               struct unpcb *unp = sotounpcb(so);
+               unp->unp_flags |= UNP_DONTDISCONNECT;
+               unp->rw_thrcount++;
+               socket_unlock(so, 0);
+
+               /* Get the locks in the correct order */
+               socket_lock(conn_so, 1);
+               socket_lock(so, 0);
+               unp->rw_thrcount--;
+               if (unp->rw_thrcount == 0) {
+                       unp->unp_flags &= ~UNP_DONTDISCONNECT;
+                       wakeup(unp);
+               }
+       }
+}
 
 static int
 uipc_abort(struct socket *so)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == 0)
-               return (EINVAL);
+       if (unp == 0) {
+               return EINVAL;
+       }
        unp_drop(unp, ECONNABORTED);
        unp_detach(unp);
        sofree(so);
-       return (0);
+       return 0;
 }
 
 static int
@@ -161,8 +221,9 @@ uipc_accept(struct socket *so, struct sockaddr **nam)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == 0)
-               return (EINVAL);
+       if (unp == 0) {
+               return EINVAL;
+       }
 
        /*
         * Pass back name of connected socket,
@@ -175,7 +236,7 @@ uipc_accept(struct socket *so, struct sockaddr **nam)
        } else {
                *nam = dup_sockaddr((struct sockaddr *)&sun_noname, 1);
        }
-       return (0);
+       return 0;
 }
 
 /*
@@ -188,9 +249,10 @@ uipc_attach(struct socket *so, __unused int proto, __unused proc_t p)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp != 0)
-               return (EISCONN);
-       return (unp_attach(so));
+       if (unp != 0) {
+               return EISCONN;
+       }
+       return unp_attach(so);
 }
 
 static int
@@ -198,10 +260,11 @@ uipc_bind(struct socket *so, struct sockaddr *nam, proc_t p)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == 0)
-               return (EINVAL);
+       if (unp == 0) {
+               return EINVAL;
+       }
 
-       return (unp_bind(unp, nam, p));
+       return unp_bind(unp, nam, p);
 }
 
 /*
@@ -214,9 +277,10 @@ uipc_connect(struct socket *so, struct sockaddr *nam, proc_t p)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == 0)
-               return (EINVAL);
-       return (unp_connect(so, nam, p));
+       if (unp == 0) {
+               return EINVAL;
+       }
+       return unp_connect(so, nam, p);
 }
 
 /*
@@ -230,10 +294,11 @@ uipc_connect2(struct socket *so1, struct socket *so2)
 {
        struct unpcb *unp = sotounpcb(so1);
 
-       if (unp == 0)
-               return (EINVAL);
+       if (unp == 0) {
+               return EINVAL;
+       }
 
-       return (unp_connect2(so1, so2));
+       return unp_connect2(so1, so2);
 }
 
 /* control is EOPNOTSUPP */
@@ -243,11 +308,13 @@ uipc_detach(struct socket *so)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == 0)
-               return (EINVAL);
+       if (unp == 0) {
+               return EINVAL;
+       }
 
+       LCK_MTX_ASSERT(&unp->unp_mtx, LCK_MTX_ASSERT_OWNED);
        unp_detach(unp);
-       return (0);
+       return 0;
 }
 
 static int
@@ -255,10 +322,11 @@ uipc_disconnect(struct socket *so)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == 0)
-               return (EINVAL);
+       if (unp == 0) {
+               return EINVAL;
+       }
        unp_disconnect(unp);
-       return (0);
+       return 0;
 }
 
 /*
@@ -270,9 +338,10 @@ uipc_listen(struct socket *so, __unused proc_t p)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == 0 || unp->unp_vnode == 0)
-               return (EINVAL);
-       return (unp_listen(unp, p));
+       if (unp == 0 || unp->unp_vnode == 0) {
+               return EINVAL;
+       }
+       return unp_listen(unp, p);
 }
 
 static int
@@ -280,15 +349,16 @@ uipc_peeraddr(struct socket *so, struct sockaddr **nam)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == NULL)
-               return (EINVAL);
+       if (unp == NULL) {
+               return EINVAL;
+       }
        if (unp->unp_conn != NULL && unp->unp_conn->unp_addr != NULL) {
                *nam = dup_sockaddr((struct sockaddr *)
                    unp->unp_conn->unp_addr, 1);
        } else {
                *nam = dup_sockaddr((struct sockaddr *)&sun_noname, 1);
        }
-       return (0);
+       return 0;
 }
 
 static int
@@ -297,19 +367,23 @@ uipc_rcvd(struct socket *so, __unused int flags)
        struct unpcb *unp = sotounpcb(so);
        struct socket *so2;
 
-       if (unp == 0)
-               return (EINVAL);
+       if (unp == 0) {
+               return EINVAL;
+       }
        switch (so->so_type) {
        case SOCK_DGRAM:
                panic("uipc_rcvd DGRAM?");
-               /*NOTREACHED*/
+       /*NOTREACHED*/
 
        case SOCK_STREAM:
-#define        rcv (&so->so_rcv)
-#define        snd (&so2->so_snd)
-               if (unp->unp_conn == 0)
+#define rcv (&so->so_rcv)
+#define snd (&so2->so_snd)
+               if (unp->unp_conn == 0) {
                        break;
+               }
+
                so2 = unp->unp_conn->unp_socket;
+               unp_get_locks_in_order(so, so2);
                /*
                 * Adjust backpressure on sender
                 * and wakeup any waiting to write.
@@ -318,7 +392,12 @@ uipc_rcvd(struct socket *so, __unused int flags)
                unp->unp_mbcnt = rcv->sb_mbcnt;
                snd->sb_hiwat += unp->unp_cc - rcv->sb_cc;
                unp->unp_cc = rcv->sb_cc;
-               sowwakeup(so2);
+               if (sb_notify(&so2->so_snd)) {
+                       sowakeup(so2, &so2->so_snd, so);
+               }
+
+               socket_unlock(so2, 1);
+
 #undef snd
 #undef rcv
                break;
@@ -326,7 +405,7 @@ uipc_rcvd(struct socket *so, __unused int flags)
        default:
                panic("uipc_rcvd unknown socktype");
        }
-       return (0);
+       return 0;
 }
 
 /* pru_rcvoob is EOPNOTSUPP */
@@ -368,12 +447,13 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
        }
 
        if (control) {
-               /* release global lock to avoid deadlock (4436174) */
+               /* release lock to avoid deadlock (4436174) */
                socket_unlock(so, 0);
                error = unp_internalize(control, p);
                socket_lock(so, 0);
-               if (error)
+               if (error) {
                        goto release;
+               }
        }
 
        switch (so->so_type) {
@@ -387,19 +467,26 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
                                break;
                        }
                        error = unp_connect(so, nam, p);
-                       if (error)
+                       if (error) {
                                break;
+                       }
                } else {
                        if (unp->unp_conn == 0) {
                                error = ENOTCONN;
                                break;
                        }
                }
+
                so2 = unp->unp_conn->unp_socket;
-               if (unp->unp_addr)
+               if (so != so2) {
+                       unp_get_locks_in_order(so, so2);
+               }
+
+               if (unp->unp_addr) {
                        from = (struct sockaddr *)unp->unp_addr;
-               else
+               } else {
                        from = &sun_noname;
+               }
                /*
                 * sbappendaddr() will fail when the receiver runs out of
                 * space; in contrast to SOCK_STREAM, we will lose messages
@@ -410,21 +497,29 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
                 */
                if (sbappendaddr(&so2->so_rcv, from, m, control, &error)) {
                        control = NULL;
-                       sorwakeup(so2);
+                       if (sb_notify(&so2->so_rcv)) {
+                               sowakeup(so2, &so2->so_rcv, so);
+                       }
                } else if (control != NULL && error == 0) {
                        /* A socket filter took control; don't touch it */
                        control = NULL;
                }
+
+               if (so != so2) {
+                       socket_unlock(so2, 1);
+               }
+
                m = NULL;
-               if (nam)
+               if (nam) {
                        unp_disconnect(unp);
+               }
                break;
        }
 
        case SOCK_STREAM: {
                int didreceive = 0;
-#define        rcv (&so2->so_rcv)
-#define        snd (&so->so_snd)
+#define rcv (&so2->so_rcv)
+#define snd (&so->so_snd)
                /* Connect if not connected yet. */
                /*
                 * Note: A better implementation would complain
@@ -433,8 +528,9 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
                if ((so->so_state & SS_ISCONNECTED) == 0) {
                        if (nam) {
                                error = unp_connect(so, nam, p);
-                               if (error)
-                                       break;  /* XXX */
+                               if (error) {
+                                       break;  /* XXX */
+                               }
                        } else {
                                error = ENOTCONN;
                                break;
@@ -445,9 +541,33 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
                        error = EPIPE;
                        break;
                }
-               if (unp->unp_conn == 0)
+               if (unp->unp_conn == 0) {
                        panic("uipc_send connected but no connection?");
+               }
+
                so2 = unp->unp_conn->unp_socket;
+               unp_get_locks_in_order(so, so2);
+
+               /* Check socket state again as we might have unlocked the socket
+                * while trying to get the locks in order
+                */
+
+               if ((so->so_state & SS_CANTSENDMORE)) {
+                       error = EPIPE;
+                       socket_unlock(so2, 1);
+                       break;
+               }
+
+               if (unp->unp_flags & UNP_TRACE_MDNS) {
+                       struct mdns_ipc_msg_hdr hdr;
+
+                       if (mbuf_copydata(m, 0, sizeof(hdr), &hdr) == 0 &&
+                           hdr.version == ntohl(MDNS_IPC_MSG_HDR_VERSION_1)) {
+                               printf("%s[mDNSResponder] pid=%d (%s): op=0x%x\n",
+                                   __func__, p->p_pid, p->p_comm, ntohl(hdr.op));
+                       }
+               }
+
                /*
                 * Send to paired receive port, and then reduce send buffer
                 * hiwater marks to maintain backpressure.  Wake up readers.
@@ -462,20 +582,29 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
 
                snd->sb_mbmax -= rcv->sb_mbcnt - unp->unp_conn->unp_mbcnt;
                unp->unp_conn->unp_mbcnt = rcv->sb_mbcnt;
-               snd->sb_hiwat -= rcv->sb_cc - unp->unp_conn->unp_cc;
+               if ((int32_t)snd->sb_hiwat >=
+                   (int32_t)(rcv->sb_cc - unp->unp_conn->unp_cc)) {
+                       snd->sb_hiwat -= rcv->sb_cc - unp->unp_conn->unp_cc;
+               } else {
+                       snd->sb_hiwat = 0;
+               }
                unp->unp_conn->unp_cc = rcv->sb_cc;
                if (didreceive) {
                        control = NULL;
-                       sorwakeup(so2);
+                       if (sb_notify(&so2->so_rcv)) {
+                               sowakeup(so2, &so2->so_rcv, so);
+                       }
                } else if (control != NULL && error == 0) {
                        /* A socket filter took control; don't touch it */
                        control = NULL;
                }
+
+               socket_unlock(so2, 1);
                m = NULL;
 #undef snd
 #undef rcv
-               }
-               break;
+       }
+       break;
 
        default:
                panic("uipc_send unknown socktype");
@@ -497,11 +626,13 @@ uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
        }
 
 release:
-       if (control)
+       if (control) {
                m_freem(control);
-       if (m)
+       }
+       if (m) {
                m_freem(m);
-       return (error);
+       }
+       return error;
 }
 
 static int
@@ -511,16 +642,18 @@ uipc_sense(struct socket *so, void *ub, int isstat64)
        struct socket *so2;
        blksize_t blksize;
 
-       if (unp == 0)
-               return (EINVAL);
+       if (unp == 0) {
+               return EINVAL;
+       }
 
        blksize = so->so_snd.sb_hiwat;
        if (so->so_type == SOCK_STREAM && unp->unp_conn != 0) {
                so2 = unp->unp_conn->unp_socket;
                blksize += so2->so_rcv.sb_cc;
        }
-       if (unp->unp_ino == 0)
+       if (unp->unp_ino == 0) {
                unp->unp_ino = unp_ino++;
+       }
 
        if (isstat64 != 0) {
                struct stat64  *sb64;
@@ -535,10 +668,10 @@ uipc_sense(struct socket *so, void *ub, int isstat64)
                sb = (struct stat *)ub;
                sb->st_blksize = blksize;
                sb->st_dev = NODEV;
-               sb->st_ino = (ino_t)unp->unp_ino;
+               sb->st_ino = (ino_t)(uintptr_t)unp->unp_ino;
        }
 
-       return (0);
+       return 0;
 }
 
 /*
@@ -555,11 +688,12 @@ uipc_shutdown(struct socket *so)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == 0)
-               return (EINVAL);
+       if (unp == 0) {
+               return EINVAL;
+       }
        socantsendmore(so);
        unp_shutdown(unp);
-       return (0);
+       return 0;
 }
 
 /*
@@ -571,29 +705,44 @@ uipc_sockaddr(struct socket *so, struct sockaddr **nam)
 {
        struct unpcb *unp = sotounpcb(so);
 
-       if (unp == NULL)
-               return (EINVAL);
+       if (unp == NULL) {
+               return EINVAL;
+       }
        if (unp->unp_addr != NULL) {
                *nam = dup_sockaddr((struct sockaddr *)unp->unp_addr, 1);
        } else {
                *nam = dup_sockaddr((struct sockaddr *)&sun_noname, 1);
        }
-       return (0);
+       return 0;
 }
 
 struct pr_usrreqs uipc_usrreqs = {
-       uipc_abort, uipc_accept, uipc_attach, uipc_bind, uipc_connect,
-       uipc_connect2, pru_control_notsupp, uipc_detach, uipc_disconnect,
-       uipc_listen, uipc_peeraddr, uipc_rcvd, pru_rcvoob_notsupp,
-       uipc_send, uipc_sense, uipc_shutdown, uipc_sockaddr,
-       sosend, soreceive, pru_sopoll_notsupp
+       .pru_abort =            uipc_abort,
+       .pru_accept =           uipc_accept,
+       .pru_attach =           uipc_attach,
+       .pru_bind =             uipc_bind,
+       .pru_connect =          uipc_connect,
+       .pru_connect2 =         uipc_connect2,
+       .pru_detach =           uipc_detach,
+       .pru_disconnect =       uipc_disconnect,
+       .pru_listen =           uipc_listen,
+       .pru_peeraddr =         uipc_peeraddr,
+       .pru_rcvd =             uipc_rcvd,
+       .pru_send =             uipc_send,
+       .pru_sense =            uipc_sense,
+       .pru_shutdown =         uipc_shutdown,
+       .pru_sockaddr =         uipc_sockaddr,
+       .pru_sosend =           sosend,
+       .pru_soreceive =        soreceive,
 };
 
 int
 uipc_ctloutput(struct socket *so, struct sockopt *sopt)
 {
        struct unpcb *unp = sotounpcb(so);
-       int error;
+       int error = 0;
+       pid_t peerpid;
+       struct socket *peerso;
 
        switch (sopt->sopt_dir) {
        case SOPT_GET:
@@ -601,13 +750,55 @@ uipc_ctloutput(struct socket *so, struct sockopt *sopt)
                case LOCAL_PEERCRED:
                        if (unp->unp_flags & UNP_HAVEPC) {
                                error = sooptcopyout(sopt, &unp->unp_peercred,
-                                   sizeof (unp->unp_peercred));
+                                   sizeof(unp->unp_peercred));
                        } else {
-                               if (so->so_type == SOCK_STREAM)
+                               if (so->so_type == SOCK_STREAM) {
                                        error = ENOTCONN;
-                               else
+                               } else {
                                        error = EINVAL;
+                               }
+                       }
+                       break;
+               case LOCAL_PEERPID:
+               case LOCAL_PEEREPID:
+                       if (unp->unp_conn == NULL) {
+                               error = ENOTCONN;
+                               break;
+                       }
+                       peerso = unp->unp_conn->unp_socket;
+                       if (peerso == NULL) {
+                               panic("peer is connected but has no socket?");
+                       }
+                       unp_get_locks_in_order(so, peerso);
+                       if (sopt->sopt_name == LOCAL_PEEREPID &&
+                           peerso->so_flags & SOF_DELEGATED) {
+                               peerpid = peerso->e_pid;
+                       } else {
+                               peerpid = peerso->last_pid;
+                       }
+                       socket_unlock(peerso, 1);
+                       error = sooptcopyout(sopt, &peerpid, sizeof(peerpid));
+                       break;
+               case LOCAL_PEERUUID:
+               case LOCAL_PEEREUUID:
+                       if (unp->unp_conn == NULL) {
+                               error = ENOTCONN;
+                               break;
+                       }
+                       peerso = unp->unp_conn->unp_socket;
+                       if (peerso == NULL) {
+                               panic("peer is connected but has no socket?");
+                       }
+                       unp_get_locks_in_order(so, peerso);
+                       if (sopt->sopt_name == LOCAL_PEEREUUID &&
+                           peerso->so_flags & SOF_DELEGATED) {
+                               error = sooptcopyout(sopt, &peerso->e_uuid,
+                                   sizeof(peerso->e_uuid));
+                       } else {
+                               error = sooptcopyout(sopt, &peerso->last_uuid,
+                                   sizeof(peerso->last_uuid));
                        }
+                       socket_unlock(peerso, 1);
                        break;
                default:
                        error = EOPNOTSUPP;
@@ -619,7 +810,8 @@ uipc_ctloutput(struct socket *so, struct sockopt *sopt)
                error = EOPNOTSUPP;
                break;
        }
-       return (error);
+
+       return error;
 }
 
 /*
@@ -631,28 +823,30 @@ uipc_ctloutput(struct socket *so, struct sockopt *sopt)
  * be large enough for at least one max-size datagram plus address.
  */
 #ifndef PIPSIZ
-#define        PIPSIZ  8192
+#define PIPSIZ  8192
 #endif
-static u_long  unpst_sendspace = PIPSIZ;
-static u_long  unpst_recvspace = PIPSIZ;
-static u_long  unpdg_sendspace = 2*1024;       /* really max datagram size */
-static u_long  unpdg_recvspace = 4*1024;
+static u_int32_t        unpst_sendspace = PIPSIZ;
+static u_int32_t        unpst_recvspace = PIPSIZ;
+static u_int32_t        unpdg_sendspace = 2 * 1024;       /* really max datagram size */
+static u_int32_t        unpdg_recvspace = 4 * 1024;
 
-static int     unp_rights;                     /* file descriptors in flight */
-static int     unp_disposed;                   /* discarded file descriptors */
+static int      unp_rights;                     /* file descriptors in flight */
+static int      unp_disposed;                   /* discarded file descriptors */
 
 SYSCTL_DECL(_net_local_stream);
-SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
-   &unpst_sendspace, 0, "");
-SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
-   &unpst_recvspace, 0, "");
+SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW | CTLFLAG_LOCKED,
+    &unpst_sendspace, 0, "");
+SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW | CTLFLAG_LOCKED,
+    &unpst_recvspace, 0, "");
+SYSCTL_INT(_net_local_stream, OID_AUTO, tracemdns, CTLFLAG_RW | CTLFLAG_LOCKED,
+    &unpst_tracemdns, 0, "");
 SYSCTL_DECL(_net_local_dgram);
-SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
-   &unpdg_sendspace, 0, "");
-SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
-   &unpdg_recvspace, 0, "");
+SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW | CTLFLAG_LOCKED,
+    &unpdg_sendspace, 0, "");
+SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW | CTLFLAG_LOCKED,
+    &unpdg_recvspace, 0, "");
 SYSCTL_DECL(_net_local);
-SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, "");
+SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD | CTLFLAG_LOCKED, &unp_rights, 0, "");
 
 /*
  * Returns:    0                       Success
@@ -667,7 +861,6 @@ unp_attach(struct socket *so)
 
        if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
                switch (so->so_type) {
-
                case SOCK_STREAM:
                        error = soreserve(so, unpst_sendspace, unpst_recvspace);
                        break;
@@ -679,13 +872,19 @@ unp_attach(struct socket *so)
                default:
                        panic("unp_attach");
                }
-               if (error)
-                       return (error);
+               if (error) {
+                       return error;
+               }
        }
        unp = (struct unpcb *)zalloc(unp_zone);
-       if (unp == NULL)
-               return (ENOBUFS);
-       bzero(unp, sizeof (*unp));
+       if (unp == NULL) {
+               return ENOBUFS;
+       }
+       bzero(unp, sizeof(*unp));
+
+       lck_mtx_init(&unp->unp_mtx,
+           unp_mtx_grp, unp_mtx_attr);
+
        lck_rw_lock_exclusive(unp_list_mtx);
        LIST_INIT(&unp->unp_refs);
        unp->unp_socket = so;
@@ -693,6 +892,7 @@ unp_attach(struct socket *so)
        unp_count++;
        LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ?
            &unp_dhead : &unp_shead, unp, unp_link);
+       lck_rw_done(unp_list_mtx);
        so->so_pcb = (caddr_t)unp;
        /*
         * Mark AF_UNIX socket buffers accordingly so that:
@@ -714,46 +914,87 @@ unp_attach(struct socket *so)
         */
        so->so_rcv.sb_flags |= SB_UNIX;
        so->so_snd.sb_flags |= SB_UNIX;
-       lck_rw_done(unp_list_mtx);
-       return (0);
+       return 0;
 }
 
 static void
 unp_detach(struct unpcb *unp)
 {
+       int so_locked = 1;
+
        lck_rw_lock_exclusive(unp_list_mtx);
        LIST_REMOVE(unp, unp_link);
-       unp->unp_gencnt = ++unp_gencnt;
-       lck_rw_done(unp_list_mtx);
        --unp_count;
+       ++unp_gencnt;
+       lck_rw_done(unp_list_mtx);
        if (unp->unp_vnode) {
-               struct vnode *tvp = unp->unp_vnode;
-               unp->unp_vnode->v_socket = NULL;
-               unp->unp_vnode = NULL;
-               vnode_rele(tvp);                /* drop the usecount */
+               struct vnode *tvp = NULL;
+               socket_unlock(unp->unp_socket, 0);
+
+               /* Holding unp_connect_lock will avoid a race between
+                * a thread closing the listening socket and a thread
+                * connecting to it.
+                */
+               lck_mtx_lock(unp_connect_lock);
+               socket_lock(unp->unp_socket, 0);
+               if (unp->unp_vnode) {
+                       tvp = unp->unp_vnode;
+                       unp->unp_vnode->v_socket = NULL;
+                       unp->unp_vnode = NULL;
+               }
+               lck_mtx_unlock(unp_connect_lock);
+               if (tvp != NULL) {
+                       vnode_rele(tvp);                /* drop the usecount */
+               }
        }
-       if (unp->unp_conn)
+       if (unp->unp_conn) {
                unp_disconnect(unp);
-       while (unp->unp_refs.lh_first)
-               unp_drop(unp->unp_refs.lh_first, ECONNRESET);
+       }
+       while (unp->unp_refs.lh_first) {
+               struct unpcb *unp2 = NULL;
+
+               /* This datagram socket is connected to one or more
+                * sockets. In order to avoid a race condition between removing
+                * this reference and closing the connected socket, we need
+                * to check disconnect_in_progress
+                */
+               if (so_locked == 1) {
+                       socket_unlock(unp->unp_socket, 0);
+                       so_locked = 0;
+               }
+               lck_mtx_lock(unp_disconnect_lock);
+               while (disconnect_in_progress != 0) {
+                       (void)msleep((caddr_t)&disconnect_in_progress, unp_disconnect_lock,
+                           PSOCK, "disconnect", NULL);
+               }
+               disconnect_in_progress = 1;
+               lck_mtx_unlock(unp_disconnect_lock);
+
+               /* Now we are sure that any unpcb socket disconnect is not happening */
+               if (unp->unp_refs.lh_first != NULL) {
+                       unp2 = unp->unp_refs.lh_first;
+                       socket_lock(unp2->unp_socket, 1);
+               }
+
+               lck_mtx_lock(unp_disconnect_lock);
+               disconnect_in_progress = 0;
+               wakeup(&disconnect_in_progress);
+               lck_mtx_unlock(unp_disconnect_lock);
+
+               if (unp2 != NULL) {
+                       /* We already locked this socket and have a reference on it */
+                       unp_drop(unp2, ECONNRESET);
+                       socket_unlock(unp2->unp_socket, 1);
+               }
+       }
+
+       if (so_locked == 0) {
+               socket_lock(unp->unp_socket, 0);
+               so_locked = 1;
+       }
        soisdisconnected(unp->unp_socket);
        /* makes sure we're getting dealloced */
        unp->unp_socket->so_flags |= SOF_PCBCLEARING;
-       unp->unp_socket->so_pcb = NULL;
-       if (unp_rights) {
-               /*
-                * Normally the receive buffer is flushed later,
-                * in sofree, but if our receive buffer holds references
-                * to descriptors that are now garbage, we will dispose
-                * of those descriptor references after the garbage collector
-                * gets them (resulting in a "panic: closef: count < 0").
-                */
-               sorflush(unp->unp_socket);
-               unp_gc();
-       }
-       if (unp->unp_addr)
-               FREE(unp->unp_addr, M_SONAME);
-       zfree(unp_zone, unp);
 }
 
 /*
@@ -779,25 +1020,49 @@ unp_bind(
        vfs_context_t ctx = vfs_context_current();
        int error, namelen;
        struct nameidata nd;
+       struct socket *so = unp->unp_socket;
        char buf[SOCK_MAXADDRLEN];
 
        if (nam->sa_family != 0 && nam->sa_family != AF_UNIX) {
-               return (EAFNOSUPPORT);
+               return EAFNOSUPPORT;
+       }
+
+       /*
+        * Check if the socket is already bound to an address
+        */
+       if (unp->unp_vnode != NULL) {
+               return EINVAL;
+       }
+       /*
+        * Check if the socket may have been shut down
+        */
+       if ((so->so_state & (SS_CANTRCVMORE | SS_CANTSENDMORE)) ==
+           (SS_CANTRCVMORE | SS_CANTSENDMORE)) {
+               return EINVAL;
        }
 
-       if (unp->unp_vnode != NULL)
-               return (EINVAL);
        namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
-       if (namelen <= 0)
-               return (EINVAL);
+       if (namelen <= 0) {
+               return EINVAL;
+       }
+       /*
+        * Note: sun_path is not a zero terminated "C" string
+        */
+       if (namelen >= SOCK_MAXADDRLEN) {
+               return EINVAL;
+       }
+       bcopy(soun->sun_path, buf, namelen);
+       buf[namelen] = 0;
+
+       socket_unlock(so, 0);
 
-       strlcpy(buf, soun->sun_path, namelen+1);
-       NDINIT(&nd, CREATE, FOLLOW | LOCKPARENT, UIO_SYSSPACE32,
+       NDINIT(&nd, CREATE, OP_MKFIFO, FOLLOW | LOCKPARENT, UIO_SYSSPACE,
            CAST_USER_ADDR_T(buf), ctx);
        /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
        error = namei(&nd);
        if (error) {
-               return (error);
+               socket_lock(so, 0);
+               return error;
        }
        dvp = nd.ni_dvp;
        vp = nd.ni_vp;
@@ -812,44 +1077,61 @@ unp_bind(
                vnode_put(dvp);
                vnode_put(vp);
 
-               return (EADDRINUSE);
+               socket_lock(so, 0);
+               return EADDRINUSE;
        }
 
        VATTR_INIT(&va);
        VATTR_SET(&va, va_type, VSOCK);
        VATTR_SET(&va, va_mode, (ACCESSPERMS & ~p->p_fd->fd_cmask));
 
-#if CONFIG_MACF_SOCKET
-       /*
-        * This is #if MAC_SOCKET, because it affects the connection rate
-        * of Unix domain dockets that is critical for server performance
-        */
+#if CONFIG_MACF
        error = mac_vnode_check_create(ctx,
            nd.ni_dvp, &nd.ni_cnd, &va);
 
        if (error == 0)
-#endif /* MAC_SOCKET */
+#endif /* CONFIG_MACF */
+#if CONFIG_MACF_SOCKET_SUBSET
+       error = mac_vnode_check_uipc_bind(ctx,
+           nd.ni_dvp, &nd.ni_cnd, &va);
+
+       if (error == 0)
+#endif /* MAC_SOCKET_SUBSET */
        /* authorize before creating */
        error = vnode_authorize(dvp, NULL, KAUTH_VNODE_ADD_FILE, ctx);
 
        if (!error) {
                /* create the socket */
-               error = vn_create(dvp, &vp, &nd.ni_cnd, &va, 0, ctx);
+               error = vn_create(dvp, &vp, &nd, &va, 0, 0, NULL, ctx);
        }
 
        nameidone(&nd);
        vnode_put(dvp);
 
        if (error) {
-               return (error);
+               socket_lock(so, 0);
+               return error;
+       }
+
+       socket_lock(so, 0);
+
+       if (unp->unp_vnode != NULL) {
+               vnode_put(vp); /* drop the iocount */
+               return EINVAL;
+       }
+
+       error = vnode_ref(vp);  /* gain a longterm reference */
+       if (error) {
+               vnode_put(vp); /* drop the iocount */
+               return error;
        }
-       vnode_ref(vp);  /* gain a longterm reference */
+
        vp->v_socket = unp->unp_socket;
        unp->unp_vnode = vp;
        unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam, 1);
-       vnode_put(vp);          /* drop the iocount */
+       vnode_put(vp);          /* drop the iocount */
 
-       return (0);
+       return 0;
 }
 
 
@@ -874,7 +1156,7 @@ unp_connect(struct socket *so, struct sockaddr *nam, __unused proc_t p)
 {
        struct sockaddr_un *soun = (struct sockaddr_un *)nam;
        struct vnode *vp;
-       struct socket *so2, *so3;
+       struct socket *so2, *so3, *list_so = NULL;
        struct unpcb *unp, *unp2, *unp3;
        vfs_context_t ctx = vfs_context_current();
        int error, len;
@@ -882,69 +1164,131 @@ unp_connect(struct socket *so, struct sockaddr *nam, __unused proc_t p)
        char buf[SOCK_MAXADDRLEN];
 
        if (nam->sa_family != 0 && nam->sa_family != AF_UNIX) {
-               return (EAFNOSUPPORT);
+               return EAFNOSUPPORT;
        }
 
+       unp = sotounpcb(so);
        so2 = so3 = NULL;
 
        len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
-       if (len <= 0)
-               return (EINVAL);
+       if (len <= 0) {
+               return EINVAL;
+       }
+       /*
+        * Note: sun_path is not a zero terminated "C" string
+        */
+       if (len >= SOCK_MAXADDRLEN) {
+               return EINVAL;
+       }
+       bcopy(soun->sun_path, buf, len);
+       buf[len] = 0;
 
-       strlcpy(buf, soun->sun_path, len+1);
+       socket_unlock(so, 0);
 
-       NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE32,
+       NDINIT(&nd, LOOKUP, OP_LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE,
            CAST_USER_ADDR_T(buf), ctx);
        error = namei(&nd);
        if (error) {
-               return (error);
+               socket_lock(so, 0);
+               return error;
        }
        nameidone(&nd);
        vp = nd.ni_vp;
        if (vp->v_type != VSOCK) {
                error = ENOTSOCK;
-               goto bad;
+               socket_lock(so, 0);
+               goto out;
+       }
+
+#if CONFIG_MACF_SOCKET_SUBSET
+       error = mac_vnode_check_uipc_connect(ctx, vp, so);
+       if (error) {
+               socket_lock(so, 0);
+               goto out;
        }
+#endif /* MAC_SOCKET_SUBSET */
 
        error = vnode_authorize(vp, NULL, KAUTH_VNODE_WRITE_DATA, ctx);
-       if (error)
-               goto bad;
-       so2 = vp->v_socket;
-       if (so2 == 0 || so2->so_pcb == NULL) {
+       if (error) {
+               socket_lock(so, 0);
+               goto out;
+       }
+
+       lck_mtx_lock(unp_connect_lock);
+
+       if (vp->v_socket == 0) {
+               lck_mtx_unlock(unp_connect_lock);
                error = ECONNREFUSED;
-               goto bad;
+               socket_lock(so, 0);
+               goto out;
        }
 
-       /* make sure the socket can't go away while we're connecting */
-       so2->so_usecount++;
+       socket_lock(vp->v_socket, 1); /* Get a reference on the listening socket */
+       so2 = vp->v_socket;
+       lck_mtx_unlock(unp_connect_lock);
 
-       if (so->so_type != so2->so_type) {
-               error = EPROTOTYPE;
-               goto bad;
+
+       if (so2->so_pcb == NULL) {
+               error = ECONNREFUSED;
+               if (so != so2) {
+                       socket_unlock(so2, 1);
+                       socket_lock(so, 0);
+               } else {
+                       /* Release the reference held for the listen socket */
+                       VERIFY(so2->so_usecount > 0);
+                       so2->so_usecount--;
+               }
+               goto out;
        }
 
+       if (so < so2) {
+               socket_unlock(so2, 0);
+               socket_lock(so, 0);
+               socket_lock(so2, 0);
+       } else if (so > so2) {
+               socket_lock(so, 0);
+       }
        /*
         * Check if socket was connected while we were trying to
-        * acquire the funnel.
+        * get the socket locks in order.
         * XXX - probably shouldn't return an error for SOCK_DGRAM
         */
        if ((so->so_state & SS_ISCONNECTED) != 0) {
                error = EISCONN;
-               goto bad;
+               goto decref_out;
+       }
+
+       if (so->so_type != so2->so_type) {
+               error = EPROTOTYPE;
+               goto decref_out;
        }
 
        if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
+               /* Release the incoming socket but keep a reference */
+               socket_unlock(so, 0);
+
                if ((so2->so_options & SO_ACCEPTCONN) == 0 ||
                    (so3 = sonewconn(so2, 0, nam)) == 0) {
                        error = ECONNREFUSED;
-                       goto bad;
+                       if (so != so2) {
+                               socket_unlock(so2, 1);
+                               socket_lock(so, 0);
+                       } else {
+                               socket_lock(so, 0);
+                               /* Release the reference held for
+                                * listen socket.
+                                */
+                               VERIFY(so2->so_usecount > 0);
+                               so2->so_usecount--;
+                       }
+                       goto out;
                }
-               unp = sotounpcb(so);
                unp2 = sotounpcb(so2);
                unp3 = sotounpcb(so3);
-               if (unp2->unp_addr)
+               if (unp2->unp_addr) {
                        unp3->unp_addr = (struct sockaddr_un *)
                            dup_sockaddr((struct sockaddr *)unp2->unp_addr, 1);
+               }
 
                /*
                 * unp_peercred management:
@@ -964,8 +1308,28 @@ unp_connect(struct socket *so, struct sockaddr *nam, __unused proc_t p)
                 */
                KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
                    ("unp_connect: listener without cached peercred"));
+
+               /* Here we need to have both so and so2 locks and so2
+                * is already locked. Lock ordering is required.
+                */
+               if (so < so2) {
+                       socket_unlock(so2, 0);
+                       socket_lock(so, 0);
+                       socket_lock(so2, 0);
+               } else {
+                       socket_lock(so, 0);
+               }
+
+               /* Check again if the socket state changed when its lock was released */
+               if ((so->so_state & SS_ISCONNECTED) != 0) {
+                       error = EISCONN;
+                       socket_unlock(so2, 1);
+                       socket_lock(so3, 0);
+                       sofreelastref(so3, 1);
+                       goto out;
+               }
                memcpy(&unp->unp_peercred, &unp2->unp_peercred,
-                   sizeof (unp->unp_peercred));
+                   sizeof(unp->unp_peercred));
                unp->unp_flags |= UNP_HAVEPC;
 
 #if CONFIG_MACF_SOCKET
@@ -974,16 +1338,53 @@ unp_connect(struct socket *so, struct sockaddr *nam, __unused proc_t p)
                mac_socketpeer_label_associate_socket(so3, so);
                /* XXXMAC: SOCK_UNLOCK(so); */
 #endif /* MAC_SOCKET */
-               so2->so_usecount--; /* drop reference taken on so2 */
+
+               /* Hold the reference on listening socket until the end */
+               socket_unlock(so2, 0);
+               list_so = so2;
+
+               /* Lock ordering doesn't matter because so3 was just created */
+               socket_lock(so3, 1);
                so2 = so3;
-               so3->so_usecount++; /* make sure we keep it around */
+
+               /*
+                * Enable tracing for mDNSResponder endpoints.  (The use
+                * of sizeof instead of strlen below takes the null
+                * terminating character into account.)
+                */
+               if (unpst_tracemdns &&
+                   !strncmp(soun->sun_path, MDNSRESPONDER_PATH,
+                   sizeof(MDNSRESPONDER_PATH))) {
+                       unp->unp_flags |= UNP_TRACE_MDNS;
+                       unp2->unp_flags |= UNP_TRACE_MDNS;
+               }
        }
+
        error = unp_connect2(so, so2);
-bad:
-       if (so2 != NULL)
-               so2->so_usecount--; /* release count on socket */
+
+decref_out:
+       if (so2 != NULL) {
+               if (so != so2) {
+                       socket_unlock(so2, 1);
+               } else {
+                       /* Release the extra reference held for the listen socket.
+                        * This is possible only for SOCK_DGRAM sockets. We refuse
+                        * connecting to the same socket for SOCK_STREAM sockets.
+                        */
+                       VERIFY(so2->so_usecount > 0);
+                       so2->so_usecount--;
+               }
+       }
+
+       if (list_so != NULL) {
+               socket_lock(list_so, 0);
+               socket_unlock(list_so, 1);
+       }
+
+out:
+       LCK_MTX_ASSERT(&unp->unp_mtx, LCK_MTX_ASSERT_OWNED);
        vnode_put(vp);
-       return (error);
+       return error;
 }
 
 /*
@@ -997,20 +1398,41 @@ unp_connect2(struct socket *so, struct socket *so2)
        struct unpcb *unp = sotounpcb(so);
        struct unpcb *unp2;
 
-       if (so2->so_type != so->so_type)
-               return (EPROTOTYPE);
+       if (so2->so_type != so->so_type) {
+               return EPROTOTYPE;
+       }
+
        unp2 = sotounpcb(so2);
 
+       LCK_MTX_ASSERT(&unp->unp_mtx, LCK_MTX_ASSERT_OWNED);
+       LCK_MTX_ASSERT(&unp2->unp_mtx, LCK_MTX_ASSERT_OWNED);
+
        /* Verify both sockets are still opened */
-       if (unp == 0 || unp2 == 0)
-               return (EINVAL);
+       if (unp == 0 || unp2 == 0) {
+               return EINVAL;
+       }
 
        unp->unp_conn = unp2;
-       switch (so->so_type) {
+       so2->so_usecount++;
 
+       switch (so->so_type) {
        case SOCK_DGRAM:
                LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
-               soisconnected(so);
+
+               if (so != so2) {
+                       /* Avoid lock order reversals due to drop/acquire in soisconnected. */
+                       /* Keep an extra reference on so2 that will be dropped
+                        * soon after getting the locks in order
+                        */
+                       socket_unlock(so2, 0);
+                       soisconnected(so);
+                       unp_get_locks_in_order(so, so2);
+                       VERIFY(so2->so_usecount > 0);
+                       so2->so_usecount--;
+               } else {
+                       soisconnected(so);
+               }
+
                break;
 
        case SOCK_STREAM:
@@ -1024,49 +1446,216 @@ unp_connect2(struct socket *so, struct socket *so2)
                        unp2->unp_flags |= UNP_HAVEPC;
                }
                unp2->unp_conn = unp;
-               soisconnected(so);
+               so->so_usecount++;
+
+               /* Avoid lock order reversals due to drop/acquire in soisconnected. */
+               socket_unlock(so, 0);
                soisconnected(so2);
+
+               /* Keep an extra reference on so2, that will be dropped soon after
+                * getting the locks in order again.
+                */
+               socket_unlock(so2, 0);
+
+               socket_lock(so, 0);
+               soisconnected(so);
+
+               unp_get_locks_in_order(so, so2);
+               /* Decrement the extra reference left before */
+               VERIFY(so2->so_usecount > 0);
+               so2->so_usecount--;
                break;
 
        default:
-               panic("unp_connect2");
+               panic("unknown socket type %d in unp_connect2", so->so_type);
        }
-       return (0);
+       LCK_MTX_ASSERT(&unp->unp_mtx, LCK_MTX_ASSERT_OWNED);
+       LCK_MTX_ASSERT(&unp2->unp_mtx, LCK_MTX_ASSERT_OWNED);
+       return 0;
 }
 
 static void
 unp_disconnect(struct unpcb *unp)
 {
-       struct unpcb *unp2 = unp->unp_conn;
+       struct unpcb *unp2 = NULL;
+       struct socket *so2 = NULL, *so;
+       struct socket *waitso;
+       int so_locked = 1, strdisconn = 0;
 
-       if (unp2 == 0)
+       so = unp->unp_socket;
+       if (unp->unp_conn == NULL) {
                return;
-       unp->unp_conn = NULL;
-       switch (unp->unp_socket->so_type) {
+       }
+       lck_mtx_lock(unp_disconnect_lock);
+       while (disconnect_in_progress != 0) {
+               if (so_locked == 1) {
+                       socket_unlock(so, 0);
+                       so_locked = 0;
+               }
+               (void)msleep((caddr_t)&disconnect_in_progress, unp_disconnect_lock,
+                   PSOCK, "disconnect", NULL);
+       }
+       disconnect_in_progress = 1;
+       lck_mtx_unlock(unp_disconnect_lock);
+
+       if (so_locked == 0) {
+               socket_lock(so, 0);
+               so_locked = 1;
+       }
+
+       unp2 = unp->unp_conn;
+
+       if (unp2 == 0 || unp2->unp_socket == NULL) {
+               goto out;
+       }
+       so2 = unp2->unp_socket;
+
+try_again:
+       if (so == so2) {
+               if (so_locked == 0) {
+                       socket_lock(so, 0);
+               }
+               waitso = so;
+       } else if (so < so2) {
+               if (so_locked == 0) {
+                       socket_lock(so, 0);
+               }
+               socket_lock(so2, 1);
+               waitso = so2;
+       } else {
+               if (so_locked == 1) {
+                       socket_unlock(so, 0);
+               }
+               socket_lock(so2, 1);
+               socket_lock(so, 0);
+               waitso = so;
+       }
+       so_locked = 1;
+
+       LCK_MTX_ASSERT(&unp->unp_mtx, LCK_MTX_ASSERT_OWNED);
+       LCK_MTX_ASSERT(&unp2->unp_mtx, LCK_MTX_ASSERT_OWNED);
 
+       /* Check for the UNP_DONTDISCONNECT flag, if it
+        * is set, release both sockets and go to sleep
+        */
+
+       if ((((struct unpcb *)waitso->so_pcb)->unp_flags & UNP_DONTDISCONNECT) != 0) {
+               if (so != so2) {
+                       socket_unlock(so2, 1);
+               }
+               so_locked = 0;
+
+               (void)msleep(waitso->so_pcb, &unp->unp_mtx,
+                   PSOCK | PDROP, "unpdisconnect", NULL);
+               goto try_again;
+       }
+
+       if (unp->unp_conn == NULL) {
+               panic("unp_conn became NULL after sleep");
+       }
+
+       unp->unp_conn = NULL;
+       VERIFY(so2->so_usecount > 0);
+       so2->so_usecount--;
+
+       if (unp->unp_flags & UNP_TRACE_MDNS) {
+               unp->unp_flags &= ~UNP_TRACE_MDNS;
+       }
+
+       switch (unp->unp_socket->so_type) {
        case SOCK_DGRAM:
-               lck_rw_lock_exclusive(unp_list_mtx);
                LIST_REMOVE(unp, unp_reflink);
-               lck_rw_done(unp_list_mtx);
                unp->unp_socket->so_state &= ~SS_ISCONNECTED;
+               if (so != so2) {
+                       socket_unlock(so2, 1);
+               }
                break;
 
        case SOCK_STREAM:
-               soisdisconnected(unp->unp_socket);
                unp2->unp_conn = NULL;
-               soisdisconnected(unp2->unp_socket);
+               VERIFY(so->so_usecount > 0);
+               so->so_usecount--;
+
+               /* Set the socket state correctly but do a wakeup later when
+                * we release all locks except the socket lock, this will avoid
+                * a deadlock.
+                */
+               unp->unp_socket->so_state &= ~(SS_ISCONNECTING | SS_ISCONNECTED | SS_ISDISCONNECTING);
+               unp->unp_socket->so_state |= (SS_CANTRCVMORE | SS_CANTSENDMORE | SS_ISDISCONNECTED);
+
+               unp2->unp_socket->so_state &= ~(SS_ISCONNECTING | SS_ISCONNECTED | SS_ISDISCONNECTING);
+               unp->unp_socket->so_state |= (SS_CANTRCVMORE | SS_CANTSENDMORE | SS_ISDISCONNECTED);
+
+               if (unp2->unp_flags & UNP_TRACE_MDNS) {
+                       unp2->unp_flags &= ~UNP_TRACE_MDNS;
+               }
+
+               strdisconn = 1;
                break;
+       default:
+               panic("unknown socket type %d", so->so_type);
        }
-}
+out:
+       lck_mtx_lock(unp_disconnect_lock);
+       disconnect_in_progress = 0;
+       wakeup(&disconnect_in_progress);
+       lck_mtx_unlock(unp_disconnect_lock);
 
-#ifdef notdef
-void
-unp_abort(struct unpcb *unp)
-{
+       if (strdisconn) {
+               socket_unlock(so, 0);
+               soisdisconnected(so2);
+               socket_unlock(so2, 1);
 
-       unp_detach(unp);
+               socket_lock(so, 0);
+               soisdisconnected(so);
+       }
+       LCK_MTX_ASSERT(&unp->unp_mtx, LCK_MTX_ASSERT_OWNED);
+       return;
 }
+
+/*
+ * unpcb_to_compat copies specific bits of a unpcb to a unpcb_compat format.
+ * The unpcb_compat data structure is passed to user space and must not change.
+ */
+static void
+unpcb_to_compat(struct unpcb *up, struct unpcb_compat *cp)
+{
+#if defined(__LP64__)
+       cp->unp_link.le_next = (u_int32_t)
+           VM_KERNEL_ADDRPERM(up->unp_link.le_next);
+       cp->unp_link.le_prev = (u_int32_t)
+           VM_KERNEL_ADDRPERM(up->unp_link.le_prev);
+#else
+       cp->unp_link.le_next = (struct unpcb_compat *)
+           VM_KERNEL_ADDRPERM(up->unp_link.le_next);
+       cp->unp_link.le_prev = (struct unpcb_compat **)
+           VM_KERNEL_ADDRPERM(up->unp_link.le_prev);
+#endif
+       cp->unp_socket = (_UNPCB_PTR(struct socket *))
+           VM_KERNEL_ADDRPERM(up->unp_socket);
+       cp->unp_vnode = (_UNPCB_PTR(struct vnode *))
+           VM_KERNEL_ADDRPERM(up->unp_vnode);
+       cp->unp_ino = up->unp_ino;
+       cp->unp_conn = (_UNPCB_PTR(struct unpcb_compat *))
+           VM_KERNEL_ADDRPERM(up->unp_conn);
+       cp->unp_refs = (u_int32_t)VM_KERNEL_ADDRPERM(up->unp_refs.lh_first);
+#if defined(__LP64__)
+       cp->unp_reflink.le_next =
+           (u_int32_t)VM_KERNEL_ADDRPERM(up->unp_reflink.le_next);
+       cp->unp_reflink.le_prev =
+           (u_int32_t)VM_KERNEL_ADDRPERM(up->unp_reflink.le_prev);
+#else
+       cp->unp_reflink.le_next =
+           (struct unpcb_compat *)VM_KERNEL_ADDRPERM(up->unp_reflink.le_next);
+       cp->unp_reflink.le_prev =
+           (struct unpcb_compat **)VM_KERNEL_ADDRPERM(up->unp_reflink.le_prev);
 #endif
+       cp->unp_addr = (_UNPCB_PTR(struct sockaddr_un *))
+           VM_KERNEL_ADDRPERM(up->unp_addr);
+       cp->unp_cc = up->unp_cc;
+       cp->unp_mbcnt = up->unp_mbcnt;
+       cp->unp_gencnt = up->unp_gencnt;
+}
 
 static int
 unp_pcblist SYSCTL_HANDLER_ARGS
@@ -1087,15 +1676,15 @@ unp_pcblist SYSCTL_HANDLER_ARGS
         */
        if (req->oldptr == USER_ADDR_NULL) {
                n = unp_count;
-               req->oldidx = 2 * sizeof (xug) + (n + n / 8) *
-                   sizeof (struct xunpcb);
+               req->oldidx = 2 * sizeof(xug) + (n + n / 8) *
+                   sizeof(struct xunpcb);
                lck_rw_done(unp_list_mtx);
-               return (0);
+               return 0;
        }
 
        if (req->newptr != USER_ADDR_NULL) {
                lck_rw_done(unp_list_mtx);
-               return (EPERM);
+               return EPERM;
        }
 
        /*
@@ -1104,38 +1693,39 @@ unp_pcblist SYSCTL_HANDLER_ARGS
        gencnt = unp_gencnt;
        n = unp_count;
 
-       bzero(&xug, sizeof (xug));
-       xug.xug_len = sizeof (xug);
+       bzero(&xug, sizeof(xug));
+       xug.xug_len = sizeof(xug);
        xug.xug_count = n;
        xug.xug_gen = gencnt;
        xug.xug_sogen = so_gencnt;
-       error = SYSCTL_OUT(req, &xug, sizeof (xug));
+       error = SYSCTL_OUT(req, &xug, sizeof(xug));
        if (error) {
                lck_rw_done(unp_list_mtx);
-               return (error);
+               return error;
        }
 
        /*
         * We are done if there is no pcb
         */
-       if (n == 0)  {
+       if (n == 0) {
                lck_rw_done(unp_list_mtx);
-               return (0);
+               return 0;
        }
 
-       MALLOC(unp_list, struct unpcb **, n * sizeof (*unp_list),
+       MALLOC(unp_list, struct unpcb **, n * sizeof(*unp_list),
            M_TEMP, M_WAITOK);
        if (unp_list == 0) {
                lck_rw_done(unp_list_mtx);
-               return (ENOMEM);
+               return ENOMEM;
        }
 
        for (unp = head->lh_first, i = 0; unp && i < n;
            unp = unp->unp_link.le_next) {
-               if (unp->unp_gencnt <= gencnt)
+               if (unp->unp_gencnt <= gencnt) {
                        unp_list[i++] = unp;
+               }
        }
-       n = i;                  /* in case we lost some during malloc */
+       n = i;                  /* in case we lost some during malloc */
 
        error = 0;
        for (i = 0; i < n; i++) {
@@ -1143,23 +1733,179 @@ unp_pcblist SYSCTL_HANDLER_ARGS
                if (unp->unp_gencnt <= gencnt) {
                        struct xunpcb xu;
 
-                       bzero(&xu, sizeof (xu));
-                       xu.xu_len = sizeof (xu);
-                       xu.xu_unpp = (struct  unpcb_compat *)unp;
+                       bzero(&xu, sizeof(xu));
+                       xu.xu_len = sizeof(xu);
+                       xu.xu_unpp = (_UNPCB_PTR(struct unpcb_compat *))
+                           VM_KERNEL_ADDRPERM(unp);
                        /*
                         * XXX - need more locking here to protect against
                         * connect/disconnect races for SMP.
                         */
-                       if (unp->unp_addr)
-                               bcopy(unp->unp_addr, &xu.xu_addr,
+                       if (unp->unp_addr) {
+                               bcopy(unp->unp_addr, &xu.xu_au,
                                    unp->unp_addr->sun_len);
-                       if (unp->unp_conn && unp->unp_conn->unp_addr)
+                       }
+                       if (unp->unp_conn && unp->unp_conn->unp_addr) {
                                bcopy(unp->unp_conn->unp_addr,
-                                   &xu.xu_caddr,
+                                   &xu.xu_cau,
                                    unp->unp_conn->unp_addr->sun_len);
-                       bcopy(unp, &xu.xu_unp, sizeof (xu.xu_unp));
+                       }
+                       unpcb_to_compat(unp, &xu.xu_unp);
                        sotoxsocket(unp->unp_socket, &xu.xu_socket);
-                       error = SYSCTL_OUT(req, &xu, sizeof (xu));
+                       error = SYSCTL_OUT(req, &xu, sizeof(xu));
+               }
+       }
+       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(&xug, sizeof(xug));
+               xug.xug_len = sizeof(xug);
+               xug.xug_gen = unp_gencnt;
+               xug.xug_sogen = so_gencnt;
+               xug.xug_count = unp_count;
+               error = SYSCTL_OUT(req, &xug, sizeof(xug));
+       }
+       FREE(unp_list, M_TEMP);
+       lck_rw_done(unp_list_mtx);
+       return error;
+}
+
+SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist,
+    CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
+    (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
+    "List of active local datagram sockets");
+SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist,
+    CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
+    (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
+    "List of active local stream sockets");
+
+#if !CONFIG_EMBEDDED
+
+static int
+unp_pcblist64 SYSCTL_HANDLER_ARGS
+{
+#pragma unused(oidp,arg2)
+       int error, i, n;
+       struct unpcb *unp, **unp_list;
+       unp_gen_t gencnt;
+       struct xunpgen xug;
+       struct unp_head *head;
+
+       lck_rw_lock_shared(unp_list_mtx);
+       head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead);
+
+       /*
+        * The process of preparing the PCB list is too time-consuming and
+        * resource-intensive to repeat twice on every request.
+        */
+       if (req->oldptr == USER_ADDR_NULL) {
+               n = unp_count;
+               req->oldidx = 2 * sizeof(xug) + (n + n / 8) *
+                   (sizeof(struct xunpcb64));
+               lck_rw_done(unp_list_mtx);
+               return 0;
+       }
+
+       if (req->newptr != USER_ADDR_NULL) {
+               lck_rw_done(unp_list_mtx);
+               return EPERM;
+       }
+
+       /*
+        * OK, now we're committed to doing something.
+        */
+       gencnt = unp_gencnt;
+       n = unp_count;
+
+       bzero(&xug, sizeof(xug));
+       xug.xug_len = sizeof(xug);
+       xug.xug_count = n;
+       xug.xug_gen = gencnt;
+       xug.xug_sogen = so_gencnt;
+       error = SYSCTL_OUT(req, &xug, sizeof(xug));
+       if (error) {
+               lck_rw_done(unp_list_mtx);
+               return error;
+       }
+
+       /*
+        * We are done if there is no pcb
+        */
+       if (n == 0) {
+               lck_rw_done(unp_list_mtx);
+               return 0;
+       }
+
+       MALLOC(unp_list, struct unpcb **, n * sizeof(*unp_list),
+           M_TEMP, M_WAITOK);
+       if (unp_list == 0) {
+               lck_rw_done(unp_list_mtx);
+               return ENOMEM;
+       }
+
+       for (unp = head->lh_first, i = 0; unp && i < n;
+           unp = unp->unp_link.le_next) {
+               if (unp->unp_gencnt <= gencnt) {
+                       unp_list[i++] = unp;
+               }
+       }
+       n = i;                  /* in case we lost some during malloc */
+
+       error = 0;
+       for (i = 0; i < n; i++) {
+               unp = unp_list[i];
+               if (unp->unp_gencnt <= gencnt) {
+                       struct xunpcb64 xu;
+                       size_t          xu_len = sizeof(struct xunpcb64);
+
+                       bzero(&xu, xu_len);
+                       xu.xu_len = xu_len;
+                       xu.xu_unpp = (u_int64_t)VM_KERNEL_ADDRPERM(unp);
+                       xu.xunp_link.le_next = (u_int64_t)
+                           VM_KERNEL_ADDRPERM(unp->unp_link.le_next);
+                       xu.xunp_link.le_prev = (u_int64_t)
+                           VM_KERNEL_ADDRPERM(unp->unp_link.le_prev);
+                       xu.xunp_socket = (u_int64_t)
+                           VM_KERNEL_ADDRPERM(unp->unp_socket);
+                       xu.xunp_vnode = (u_int64_t)
+                           VM_KERNEL_ADDRPERM(unp->unp_vnode);
+                       xu.xunp_ino = unp->unp_ino;
+                       xu.xunp_conn = (u_int64_t)
+                           VM_KERNEL_ADDRPERM(unp->unp_conn);
+                       xu.xunp_refs = (u_int64_t)
+                           VM_KERNEL_ADDRPERM(unp->unp_refs.lh_first);
+                       xu.xunp_reflink.le_next = (u_int64_t)
+                           VM_KERNEL_ADDRPERM(unp->unp_reflink.le_next);
+                       xu.xunp_reflink.le_prev = (u_int64_t)
+                           VM_KERNEL_ADDRPERM(unp->unp_reflink.le_prev);
+                       xu.xunp_cc = unp->unp_cc;
+                       xu.xunp_mbcnt = unp->unp_mbcnt;
+                       xu.xunp_gencnt = unp->unp_gencnt;
+
+                       if (unp->unp_socket) {
+                               sotoxsocket64(unp->unp_socket, &xu.xu_socket);
+                       }
+
+                       /*
+                        * XXX - need more locking here to protect against
+                        * connect/disconnect races for SMP.
+                        */
+                       if (unp->unp_addr) {
+                               bcopy(unp->unp_addr, &xu.xu_au,
+                                   unp->unp_addr->sun_len);
+                       }
+                       if (unp->unp_conn && unp->unp_conn->unp_addr) {
+                               bcopy(unp->unp_conn->unp_addr,
+                                   &xu.xu_cau,
+                                   unp->unp_conn->unp_addr->sun_len);
+                       }
+
+                       error = SYSCTL_OUT(req, &xu, xu_len);
                }
        }
        if (!error) {
@@ -1170,33 +1916,40 @@ unp_pcblist SYSCTL_HANDLER_ARGS
                 * while we were processing this request, and it
                 * might be necessary to retry.
                 */
-               bzero(&xug, sizeof (xug));
-               xug.xug_len = sizeof (xug);
+               bzero(&xug, sizeof(xug));
+               xug.xug_len = sizeof(xug);
                xug.xug_gen = unp_gencnt;
                xug.xug_sogen = so_gencnt;
                xug.xug_count = unp_count;
-               error = SYSCTL_OUT(req, &xug, sizeof (xug));
+               error = SYSCTL_OUT(req, &xug, sizeof(xug));
        }
        FREE(unp_list, M_TEMP);
        lck_rw_done(unp_list_mtx);
-       return (error);
+       return error;
 }
 
-SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD,
-           (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
-           "List of active local datagram sockets");
-SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD,
-           (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
-           "List of active local stream sockets");
+SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist64,
+    CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
+    (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist64, "S,xunpcb64",
+    "List of active local datagram sockets 64 bit");
+SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist64,
+    CTLTYPE_STRUCT | CTLFLAG_RD | CTLFLAG_LOCKED,
+    (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist64, "S,xunpcb64",
+    "List of active local stream sockets 64 bit");
+
+#endif /* !CONFIG_EMBEDDED */
 
 static void
 unp_shutdown(struct unpcb *unp)
 {
-       struct socket *so;
-
-       if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn &&
-           (so = unp->unp_conn->unp_socket))
-               socantrcvmore(so);
+       struct socket *so = unp->unp_socket;
+       struct socket *so2;
+       if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn) {
+               so2 = unp->unp_conn->unp_socket;
+               unp_get_locks_in_order(so, so2);
+               socantrcvmore(so2);
+               socket_unlock(so2, 1);
+       }
 }
 
 static void
@@ -1208,14 +1961,6 @@ unp_drop(struct unpcb *unp, int errno)
        unp_disconnect(unp);
 }
 
-#ifdef notdef
-void
-unp_drain()
-{
-
-}
-#endif
-
 /*
  * Returns:    0                       Success
  *             EMSGSIZE                The new fd's will not fit
@@ -1224,14 +1969,22 @@ unp_drain()
 int
 unp_externalize(struct mbuf *rights)
 {
-       proc_t p = current_proc();              /* XXX */
+       proc_t p = current_proc();              /* XXX */
        int i;
        struct cmsghdr *cm = mtod(rights, struct cmsghdr *);
        struct fileglob **rp = (struct fileglob **)(cm + 1);
+       int *fds = (int *)(cm + 1);
        struct fileproc *fp;
-       struct fileglob *fg;
-       int newfds = (cm->cmsg_len - sizeof (*cm)) / sizeof (int);
-       int f;
+       struct fileproc **fileproc_l;
+       int newfds = (cm->cmsg_len - sizeof(*cm)) / sizeof(int);
+       int f, error = 0;
+
+       MALLOC(fileproc_l, struct fileproc **,
+           newfds * sizeof(struct fileproc *), M_TEMP, M_WAITOK);
+       if (fileproc_l == NULL) {
+               error = ENOMEM;
+               goto discard;
+       }
 
        proc_fdlock(p);
 
@@ -1239,20 +1992,16 @@ unp_externalize(struct mbuf *rights)
         * if the new FD's will not fit, then we free them all
         */
        if (!fdavail(p, newfds)) {
-               for (i = 0; i < newfds; i++) {
-                       fg = *rp;
-                       unp_discard_fdlocked(fg, p);
-                       *rp++ = NULL;
-               }
                proc_fdunlock(p);
-
-               return (EMSGSIZE);
+               error = EMSGSIZE;
+               goto discard;
        }
        /*
         * now change each pointer to an fd in the global table to
         * an integer that is the index to the local fd table entry
         * that we set up to point to the global one we are transferring.
-        * XXX (1) this assumes a pointer and int are the same size...!
+        * XXX (1) this assumes a pointer and int are the same size,
+        * XXX     or the mbuf can hold the expansion
         * XXX (2) allocation failures should be non-fatal
         */
        for (i = 0; i < newfds; i++) {
@@ -1261,41 +2010,76 @@ unp_externalize(struct mbuf *rights)
                 * If receive access is denied, don't pass along
                 * and error message, just discard the descriptor.
                 */
-               if (mac_file_check_receive(kauth_cred_get(), *rp)) {
-                       fg = *rp;
-                       *rp++ = 0;
-                       unp_discard_fdlocked(fg, p);
+               if (mac_file_check_receive(kauth_cred_get(), rp[i])) {
+                       proc_fdunlock(p);
+                       unp_discard(rp[i], p);
+                       fds[i] = 0;
+                       proc_fdlock(p);
                        continue;
                }
 #endif
-               if (fdalloc(p, 0, &f))
+               if (fdalloc(p, 0, &f)) {
                        panic("unp_externalize:fdalloc");
-               fg = *rp;
-               MALLOC_ZONE(fp, struct fileproc *, sizeof (struct fileproc),
-                   M_FILEPROC, M_WAITOK);
-               if (fp == NULL)
+               }
+               fp = fileproc_alloc_init(NULL);
+               if (fp == NULL) {
                        panic("unp_externalize: MALLOC_ZONE");
-               bzero(fp, sizeof (struct fileproc));
-               fp->f_iocount = 0;
-               fp->f_fglob = fg;
-               fg_removeuipc(fg);
+               }
+               fp->f_fglob = rp[i];
+               if (fg_removeuipc_mark(rp[i])) {
+                       /*
+                        * Take an iocount on the fp for completing the
+                        * removal from the global msg queue
+                        */
+                       os_ref_retain_locked(&fp->f_iocount);
+                       fileproc_l[i] = fp;
+               } else {
+                       fileproc_l[i] = NULL;
+               }
                procfdtbl_releasefd(p, f, fp);
-               (void) OSAddAtomic(-1, (volatile SInt32 *)&unp_rights);
-               *(int *)rp++ = f;
+               fds[i] = f;
        }
        proc_fdunlock(p);
 
-       return (0);
+       for (i = 0; i < newfds; i++) {
+               if (fileproc_l[i] != NULL) {
+                       VERIFY(fileproc_l[i]->f_fglob != NULL &&
+                           (fileproc_l[i]->f_fglob->fg_lflags & FG_RMMSGQ));
+                       VERIFY(fds[i] >= 0);
+                       fg_removeuipc(fileproc_l[i]->f_fglob);
+
+                       /* Drop the iocount */
+                       fp_drop(p, fds[i], fileproc_l[i], 0);
+                       fileproc_l[i] = NULL;
+               }
+               if (fds[i] != 0) {
+                       (void) OSAddAtomic(-1, &unp_rights);
+               }
+       }
+
+discard:
+       if (fileproc_l != NULL) {
+               FREE(fileproc_l, M_TEMP);
+       }
+       if (error) {
+               for (i = 0; i < newfds; i++) {
+                       unp_discard(*rp, p);
+                       *rp++ = NULL;
+               }
+       }
+       return error;
 }
 
 void
 unp_init(void)
 {
-       unp_zone = zinit(sizeof (struct unpcb),
-           (nmbclusters * sizeof (struct unpcb)), 4096, "unpzone");
+       _CASSERT(UIPC_MAX_CMSG_FD >= (MCLBYTES / sizeof(int)));
+       unp_zone = zinit(sizeof(struct unpcb),
+           (nmbclusters * sizeof(struct unpcb)), 4096, "unpzone");
 
-       if (unp_zone == 0)
+       if (unp_zone == 0) {
                panic("unp_init");
+       }
        LIST_INIT(&unp_dhead);
        LIST_INIT(&unp_shead);
 
@@ -1309,13 +2093,22 @@ unp_init(void)
        unp_mtx_attr = lck_attr_alloc_init();
 
        if ((unp_list_mtx = lck_rw_alloc_init(unp_mtx_grp,
-           unp_mtx_attr)) == NULL)
-               return; /* pretty much dead if this fails... */
+           unp_mtx_attr)) == NULL) {
+               return; /* pretty much dead if this fails... */
+       }
+       if ((unp_disconnect_lock = lck_mtx_alloc_init(unp_mtx_grp,
+           unp_mtx_attr)) == NULL) {
+               return;
+       }
 
+       if ((unp_connect_lock = lck_mtx_alloc_init(unp_mtx_grp,
+           unp_mtx_attr)) == NULL) {
+               return;
+       }
 }
 
 #ifndef MIN
-#define        MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
 #endif
 
 /*
@@ -1327,59 +2120,89 @@ static int
 unp_internalize(struct mbuf *control, proc_t p)
 {
        struct cmsghdr *cm = mtod(control, struct cmsghdr *);
+       int *fds;
        struct fileglob **rp;
        struct fileproc *fp;
        int i, error;
        int oldfds;
+       uint8_t fg_ins[UIPC_MAX_CMSG_FD / 8];
 
        /* 64bit: cmsg_len is 'uint32_t', m_len is 'long' */
        if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET ||
-           (unsigned long)cm->cmsg_len != (unsigned long)control->m_len) {
-               return (EINVAL);
+           (socklen_t)cm->cmsg_len != (socklen_t)control->m_len) {
+               return EINVAL;
        }
-       oldfds = (cm->cmsg_len - sizeof (*cm)) / sizeof (int);
+       oldfds = (cm->cmsg_len - sizeof(*cm)) / sizeof(int);
+       bzero(fg_ins, sizeof(fg_ins));
 
        proc_fdlock(p);
-       rp = (struct fileglob **)(cm + 1);
+       fds = (int *)(cm + 1);
 
        for (i = 0; i < oldfds; i++) {
-               if ((error = fdgetf_noref(p, *(int *)rp++, NULL)) != 0) {
+               struct fileproc *tmpfp;
+               if (((error = fdgetf_noref(p, fds[i], &tmpfp)) != 0)) {
+                       proc_fdunlock(p);
+                       return error;
+               } else if (!file_issendable(p, tmpfp)) {
                        proc_fdunlock(p);
-                       return (error);
+                       return EINVAL;
+               } else if (FP_ISGUARDED(tmpfp, GUARD_SOCKET_IPC)) {
+                       error = fp_guard_exception(p,
+                           fds[i], tmpfp, kGUARD_EXC_SOCKET_IPC);
+                       proc_fdunlock(p);
+                       return error;
                }
        }
        rp = (struct fileglob **)(cm + 1);
 
-       for (i = 0; i < oldfds; i++) {
-               (void) fdgetf_noref(p, *(int *)rp, &fp);
-               fg_insertuipc(fp->f_fglob);
-               *rp++ = fp->f_fglob;
-               (void) OSAddAtomic(1, (volatile SInt32 *)&unp_rights);
+       /* On K64 we need to walk backwards because a fileglob * is twice the size of an fd
+        * and doing them in-order would result in stomping over unprocessed fd's
+        */
+       for (i = (oldfds - 1); i >= 0; i--) {
+               (void) fdgetf_noref(p, fds[i], &fp);
+               if (fg_insertuipc_mark(fp->f_fglob)) {
+                       fg_ins[i / 8] |= 0x80 >> (i % 8);
+               }
+               rp[i] = fp->f_fglob;
        }
        proc_fdunlock(p);
 
-       return (0);
+       for (i = 0; i < oldfds; i++) {
+               if (fg_ins[i / 8] & (0x80 >> (i % 8))) {
+                       VERIFY(rp[i]->fg_lflags & FG_INSMSGQ);
+                       fg_insertuipc(rp[i]);
+               }
+               (void) OSAddAtomic(1, &unp_rights);
+       }
+
+       return 0;
 }
 
-static int     unp_defer, unp_gcing, unp_gcwait;
+static int      unp_defer, unp_gcing, unp_gcwait;
+static thread_t unp_gcthread = NULL;
 
 /* always called under uipc_lock */
 void
 unp_gc_wait(void)
 {
+       if (unp_gcthread == current_thread()) {
+               return;
+       }
+
        while (unp_gcing != 0) {
                unp_gcwait = 1;
-               msleep(&unp_gcing, uipc_lock, 0 , "unp_gc_wait", NULL);
+               msleep(&unp_gcing, uipc_lock, 0, "unp_gc_wait", NULL);
        }
 }
 
 
-static void
+__private_extern__ void
 unp_gc(void)
 {
        struct fileglob *fg, *nextfg;
        struct socket *so;
-       struct fileglob **extra_ref, **fpp;
+       static struct fileglob **extra_ref;
+       struct fileglob **fpp;
        int nunref, i;
        int need_gcwakeup = 0;
 
@@ -1390,6 +2213,7 @@ unp_gc(void)
        }
        unp_gcing = 1;
        unp_defer = 0;
+       unp_gcthread = current_thread();
        lck_mtx_unlock(uipc_lock);
        /*
         * before going through all this, set all FDs to
@@ -1397,7 +2221,7 @@ unp_gc(void)
         */
        for (fg = fmsghead.lh_first; fg != 0; fg = fg->f_msglist.le_next) {
                lck_mtx_lock(&fg->fg_lock);
-               fg->fg_flag &= ~(FMARK|FDEFER);
+               fg->fg_flag &= ~(FMARK | FDEFER);
                lck_mtx_unlock(&fg->fg_lock);
        }
        do {
@@ -1448,21 +2272,17 @@ unp_gc(void)
                         * accessible and not already marked so.
                         * Now check if it is possibly one of OUR sockets.
                         */
-                       if (fg->fg_type != DTYPE_SOCKET ||
+                       if (FILEGLOB_DTYPE(fg) != DTYPE_SOCKET ||
                            (so = (struct socket *)fg->fg_data) == 0) {
                                lck_mtx_unlock(&fg->fg_lock);
                                continue;
                        }
-                       if (so->so_proto->pr_domain != &localdomain ||
-                           (so->so_proto->pr_flags&PR_RIGHTS) == 0) {
+                       if (so->so_proto->pr_domain != localdomain ||
+                           (so->so_proto->pr_flags & PR_RIGHTS) == 0) {
                                lck_mtx_unlock(&fg->fg_lock);
                                continue;
                        }
 #ifdef notdef
-                       /*
-                        * if this code is enabled need to run
-                        * under network funnel
-                        */
                        if (so->so_rcv.sb_flags & SB_LOCK) {
                                /*
                                 * This is problematical; it's not clear
@@ -1484,9 +2304,13 @@ unp_gc(void)
                         * to see if we hold any file descriptors in its
                         * message buffers. Follow those links and mark them
                         * as accessible too.
+                        *
+                        * In case a file is passed onto itself we need to
+                        * release the file lock.
                         */
-                       unp_scan(so->so_rcv.sb_mb, unp_mark);
                        lck_mtx_unlock(&fg->fg_lock);
+
+                       unp_scan(so->so_rcv.sb_mb, unp_mark, 0);
                }
        } while (unp_defer);
        /*
@@ -1528,8 +2352,11 @@ unp_gc(void)
         *
         * 91/09/19, bsy@cs.cmu.edu
         */
-       extra_ref = _MALLOC(nfiles * sizeof (struct fileglob *),
+       extra_ref = _MALLOC(nfiles * sizeof(struct fileglob *),
            M_FILEGLOB, M_WAITOK);
+       if (extra_ref == NULL) {
+               goto bail;
+       }
        for (nunref = 0, fg = fmsghead.lh_first, fpp = extra_ref; fg != 0;
            fg = nextfg) {
                lck_mtx_lock(&fg->fg_lock);
@@ -1563,28 +2390,26 @@ unp_gc(void)
 
                tfg = *fpp;
 
-               if (tfg->fg_type == DTYPE_SOCKET && tfg->fg_data != NULL) {
-                       int locked = 0;
-
+               if (FILEGLOB_DTYPE(tfg) == DTYPE_SOCKET &&
+                   tfg->fg_data != NULL) {
                        so = (struct socket *)(tfg->fg_data);
 
-                       /* XXXX */
-                       /* Assume local sockets use a global lock */
-                       if (so->so_proto->pr_domain->dom_family != PF_LOCAL) {
-                               socket_lock(so, 0);
-                               locked = 1;
-                       }
+                       socket_lock(so, 0);
+
                        sorflush(so);
 
-                       if (locked)
-                               socket_unlock(so, 0);
+                       socket_unlock(so, 0);
                }
        }
-       for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp)
+       for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) {
                closef_locked((struct fileproc *)0, *fpp, (proc_t)NULL);
+       }
 
-        lck_mtx_lock(uipc_lock);
+       FREE(extra_ref, M_FILEGLOB);
+bail:
+       lck_mtx_lock(uipc_lock);
        unp_gcing = 0;
+       unp_gcthread = NULL;
 
        if (unp_gcwait != 0) {
                unp_gcwait = 0;
@@ -1592,16 +2417,16 @@ unp_gc(void)
        }
        lck_mtx_unlock(uipc_lock);
 
-       if (need_gcwakeup != 0)
+       if (need_gcwakeup != 0) {
                wakeup(&unp_gcing);
-       FREE((caddr_t)extra_ref, M_FILEGLOB);
+       }
 }
 
 void
 unp_dispose(struct mbuf *m)
 {
        if (m) {
-               unp_scan(m, unp_discard);
+               unp_scan(m, unp_discard, NULL);
        }
 }
 
@@ -1615,12 +2440,11 @@ unp_listen(struct unpcb *unp, proc_t p)
        cru2x(safecred, &unp->unp_peercred);
        kauth_cred_unref(&safecred);
        unp->unp_flags |= UNP_HAVEPCCACHED;
-       return (0);
+       return 0;
 }
 
-/* should run under kernel funnel */
 static void
-unp_scan(struct mbuf *m0, void (*op)(struct fileglob *))
+unp_scan(struct mbuf *m0, void (*op)(struct fileglob *, void *arg), void *arg)
 {
        struct mbuf *m;
        struct fileglob **rp;
@@ -1629,27 +2453,29 @@ unp_scan(struct mbuf *m0, void (*op)(struct fileglob *))
        int qfds;
 
        while (m0) {
-               for (m = m0; m; m = m->m_next)
+               for (m = m0; m; m = m->m_next) {
                        if (m->m_type == MT_CONTROL &&
-                           (size_t)m->m_len >= sizeof (*cm)) {
+                           (size_t)m->m_len >= sizeof(*cm)) {
                                cm = mtod(m, struct cmsghdr *);
                                if (cm->cmsg_level != SOL_SOCKET ||
-                                   cm->cmsg_type != SCM_RIGHTS)
+                                   cm->cmsg_type != SCM_RIGHTS) {
                                        continue;
-                               qfds = (cm->cmsg_len - sizeof (*cm)) /
-                                   sizeof (struct fileglob *);
+                               }
+                               qfds = (cm->cmsg_len - sizeof(*cm)) /
+                                   sizeof(int);
                                rp = (struct fileglob **)(cm + 1);
-                               for (i = 0; i < qfds; i++)
-                                       (*op)(*rp++);
-                               break;          /* XXX, but saves time */
+                               for (i = 0; i < qfds; i++) {
+                                       (*op)(*rp++, arg);
+                               }
+                               break;          /* XXX, but saves time */
                        }
+               }
                m0 = m0->m_act;
        }
 }
 
-/* should run under kernel funnel */
 static void
-unp_mark(struct fileglob *fg)
+unp_mark(struct fileglob *fg, __unused void *arg)
 {
        lck_mtx_lock(&fg->fg_lock);
 
@@ -1657,30 +2483,124 @@ unp_mark(struct fileglob *fg)
                lck_mtx_unlock(&fg->fg_lock);
                return;
        }
-       fg->fg_flag |= (FMARK|FDEFER);
+       fg->fg_flag |= (FMARK | FDEFER);
 
        lck_mtx_unlock(&fg->fg_lock);
 
        unp_defer++;
 }
 
-/* should run under kernel funnel */
 static void
-unp_discard(struct fileglob *fg)
+unp_discard(struct fileglob *fg, void *p)
 {
-       proc_t p = current_proc();              /* XXX */
-
-       (void) OSAddAtomic(1, (volatile SInt32 *)&unp_disposed);
+       if (p == NULL) {
+               p = current_proc();             /* XXX */
+       }
+       (void) OSAddAtomic(1, &unp_disposed);
+       if (fg_removeuipc_mark(fg)) {
+               VERIFY(fg->fg_lflags & FG_RMMSGQ);
+               fg_removeuipc(fg);
+       }
+       (void) OSAddAtomic(-1, &unp_rights);
 
        proc_fdlock(p);
-       unp_discard_fdlocked(fg, p);
+       (void) closef_locked((struct fileproc *)0, fg, p);
        proc_fdunlock(p);
 }
-static void
-unp_discard_fdlocked(struct fileglob *fg, proc_t p)
+
+int
+unp_lock(struct socket *so, int refcount, void * lr)
 {
-       fg_removeuipc(fg);
+       void * lr_saved;
+       if (lr == 0) {
+               lr_saved = (void *)  __builtin_return_address(0);
+       } else {
+               lr_saved = lr;
+       }
 
-       (void) OSAddAtomic(-1, (volatile SInt32 *)&unp_rights);
-       (void) closef_locked((struct fileproc *)0, fg, p);
+       if (so->so_pcb) {
+               lck_mtx_lock(&((struct unpcb *)so->so_pcb)->unp_mtx);
+       } else {
+               panic("unp_lock: so=%p NO PCB! lr=%p ref=0x%x\n",
+                   so, lr_saved, so->so_usecount);
+       }
+
+       if (so->so_usecount < 0) {
+               panic("unp_lock: so=%p so_pcb=%p lr=%p ref=0x%x\n",
+                   so, so->so_pcb, lr_saved, so->so_usecount);
+       }
+
+       if (refcount) {
+               VERIFY(so->so_usecount > 0);
+               so->so_usecount++;
+       }
+       so->lock_lr[so->next_lock_lr] = lr_saved;
+       so->next_lock_lr = (so->next_lock_lr + 1) % SO_LCKDBG_MAX;
+       return 0;
+}
+
+int
+unp_unlock(struct socket *so, int refcount, void * lr)
+{
+       void * lr_saved;
+       lck_mtx_t * mutex_held = NULL;
+       struct unpcb *unp = sotounpcb(so);
+
+       if (lr == 0) {
+               lr_saved = (void *) __builtin_return_address(0);
+       } else {
+               lr_saved = lr;
+       }
+
+       if (refcount) {
+               so->so_usecount--;
+       }
+
+       if (so->so_usecount < 0) {
+               panic("unp_unlock: so=%p usecount=%x\n", so, so->so_usecount);
+       }
+       if (so->so_pcb == NULL) {
+               panic("unp_unlock: so=%p NO PCB usecount=%x\n", so, so->so_usecount);
+       } else {
+               mutex_held = &((struct unpcb *)so->so_pcb)->unp_mtx;
+       }
+       LCK_MTX_ASSERT(mutex_held, 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;
+
+       if (so->so_usecount == 0 && (so->so_flags & SOF_PCBCLEARING)) {
+               sofreelastref(so, 1);
+
+               if (unp->unp_addr) {
+                       FREE(unp->unp_addr, M_SONAME);
+               }
+
+               lck_mtx_unlock(mutex_held);
+
+               lck_mtx_destroy(&unp->unp_mtx, unp_mtx_grp);
+               zfree(unp_zone, unp);
+
+               unp_gc();
+       } else {
+               lck_mtx_unlock(mutex_held);
+       }
+
+       return 0;
+}
+
+lck_mtx_t *
+unp_getlock(struct socket *so, __unused int flags)
+{
+       struct unpcb *unp = (struct unpcb *)so->so_pcb;
+
+
+       if (so->so_pcb) {
+               if (so->so_usecount < 0) {
+                       panic("unp_getlock: so=%p usecount=%x\n", so, so->so_usecount);
+               }
+               return &unp->unp_mtx;
+       } else {
+               panic("unp_getlock: so=%p NULL so_pcb\n", so);
+               return so->so_proto->pr_domain->dom_mtx;
+       }
 }