diff --git a/sys/kern/uipc_usrreq.c b/sys/kern/uipc_usrreq.c
index ca23ccbdb05e..4466ae8822cd 100644
--- a/sys/kern/uipc_usrreq.c
+++ b/sys/kern/uipc_usrreq.c
@@ -1,2995 +1,2995 @@
 /*-
  * SPDX-License-Identifier: BSD-3-Clause
  *
  * Copyright (c) 1982, 1986, 1989, 1991, 1993
  *	The Regents of the University of California. All Rights Reserved.
  * Copyright (c) 2004-2009 Robert N. M. Watson All Rights Reserved.
  * Copyright (c) 2018 Matthew Macy
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  *	From: @(#)uipc_usrreq.c	8.3 (Berkeley) 1/4/94
  */
 
 /*
  * UNIX Domain (Local) Sockets
  *
  * This is an implementation of UNIX (local) domain sockets.  Each socket has
  * an associated struct unpcb (UNIX protocol control block).  Stream sockets
  * may be connected to 0 or 1 other socket.  Datagram sockets may be
  * connected to 0, 1, or many other sockets.  Sockets may be created and
  * connected in pairs (socketpair(2)), or bound/connected to using the file
  * system name space.  For most purposes, only the receive socket buffer is
  * used, as sending on one socket delivers directly to the receive socket
  * buffer of a second socket.
  *
  * The implementation is substantially complicated by the fact that
  * "ancillary data", such as file descriptors or credentials, may be passed
  * across UNIX domain sockets.  The potential for passing UNIX domain sockets
  * over other UNIX domain sockets requires the implementation of a simple
  * garbage collector to find and tear down cycles of disconnected sockets.
  *
  * TODO:
  *	RDM
  *	rethink name space problems
  *	need a proper out-of-band
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include "opt_ddb.h"
 
 #include <sys/param.h>
 #include <sys/capsicum.h>
 #include <sys/domain.h>
 #include <sys/eventhandler.h>
 #include <sys/fcntl.h>
 #include <sys/file.h>
 #include <sys/filedesc.h>
 #include <sys/kernel.h>
 #include <sys/lock.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/mount.h>
 #include <sys/mutex.h>
 #include <sys/namei.h>
 #include <sys/proc.h>
 #include <sys/protosw.h>
 #include <sys/queue.h>
 #include <sys/resourcevar.h>
 #include <sys/rwlock.h>
 #include <sys/socket.h>
 #include <sys/socketvar.h>
 #include <sys/signalvar.h>
 #include <sys/stat.h>
 #include <sys/sx.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 #include <sys/taskqueue.h>
 #include <sys/un.h>
 #include <sys/unpcb.h>
 #include <sys/vnode.h>
 
 #include <net/vnet.h>
 
 #ifdef DDB
 #include <ddb/ddb.h>
 #endif
 
 #include <security/mac/mac_framework.h>
 
 #include <vm/uma.h>
 
 MALLOC_DECLARE(M_FILECAPS);
 
 /*
  * See unpcb.h for the locking key.
  */
 
 static uma_zone_t	unp_zone;
 static unp_gen_t	unp_gencnt;	/* (l) */
 static u_int		unp_count;	/* (l) Count of local sockets. */
 static ino_t		unp_ino;	/* Prototype for fake inode numbers. */
 static int		unp_rights;	/* (g) File descriptors in flight. */
 static struct unp_head	unp_shead;	/* (l) List of stream sockets. */
 static struct unp_head	unp_dhead;	/* (l) List of datagram sockets. */
 static struct unp_head	unp_sphead;	/* (l) List of seqpacket sockets. */
 
 struct unp_defer {
 	SLIST_ENTRY(unp_defer) ud_link;
 	struct file *ud_fp;
 };
 static SLIST_HEAD(, unp_defer) unp_defers;
 static int unp_defers_count;
 
 static const struct sockaddr	sun_noname = { sizeof(sun_noname), AF_LOCAL };
 
 /*
  * Garbage collection of cyclic file descriptor/socket references occurs
  * asynchronously in a taskqueue context in order to avoid recursion and
  * reentrance in the UNIX domain socket, file descriptor, and socket layer
  * code.  See unp_gc() for a full description.
  */
 static struct timeout_task unp_gc_task;
 
 /*
  * The close of unix domain sockets attached as SCM_RIGHTS is
  * postponed to the taskqueue, to avoid arbitrary recursion depth.
  * The attached sockets might have another sockets attached.
  */
 static struct task	unp_defer_task;
 
 /*
  * Both send and receive buffers are allocated PIPSIZ bytes of buffering for
  * stream sockets, although the total for sender and receiver is actually
  * only PIPSIZ.
  *
  * Datagram sockets really use the sendspace as the maximum datagram size,
  * and don't really want to reserve the sendspace.  Their recvspace should be
  * large enough for at least one max-size datagram plus address.
  */
 #ifndef PIPSIZ
 #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_long	unpsp_sendspace = PIPSIZ;	/* really max datagram size */
 static u_long	unpsp_recvspace = PIPSIZ;
 
 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "Local domain");
 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream,
     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "SOCK_STREAM");
 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram,
     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "SOCK_DGRAM");
 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket,
     CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
     "SOCK_SEQPACKET");
 
 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
 	   &unpst_sendspace, 0, "Default stream send space.");
 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
 	   &unpst_recvspace, 0, "Default stream receive space.");
 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
 	   &unpdg_sendspace, 0, "Default datagram send space.");
 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
 	   &unpdg_recvspace, 0, "Default datagram receive space.");
 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW,
 	   &unpsp_sendspace, 0, "Default seqpacket send space.");
 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW,
 	   &unpsp_recvspace, 0, "Default seqpacket receive space.");
 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0,
     "File descriptors in flight.");
 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD,
     &unp_defers_count, 0,
     "File descriptors deferred to taskqueue for close.");
 
 /*
  * Locking and synchronization:
  *
  * Several types of locks exist in the local domain socket implementation:
  * - a global linkage lock
  * - a global connection list lock
  * - the mtxpool lock
  * - per-unpcb mutexes
  *
  * The linkage lock protects the global socket lists, the generation number
  * counter and garbage collector state.
  *
  * The connection list lock protects the list of referring sockets in a datagram
  * socket PCB.  This lock is also overloaded to protect a global list of
  * sockets whose buffers contain socket references in the form of SCM_RIGHTS
  * messages.  To avoid recursion, such references are released by a dedicated
  * thread.
  *
  * The mtxpool lock protects the vnode from being modified while referenced.
  * Lock ordering rules require that it be acquired before any PCB locks.
  *
  * The unpcb lock (unp_mtx) protects the most commonly referenced fields in the
  * unpcb.  This includes the unp_conn field, which either links two connected
  * PCBs together (for connected socket types) or points at the destination
  * socket (for connectionless socket types).  The operations of creating or
  * destroying a connection therefore involve locking multiple PCBs.  To avoid
  * lock order reversals, in some cases this involves dropping a PCB lock and
  * using a reference counter to maintain liveness.
  *
  * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer,
  * allocated in pru_attach() and freed in pru_detach().  The validity of that
  * pointer is an invariant, so no lock is required to dereference the so_pcb
  * pointer if a valid socket reference is held by the caller.  In practice,
  * this is always true during operations performed on a socket.  Each unpcb
  * has a back-pointer to its socket, unp_socket, which will be stable under
  * the same circumstances.
  *
  * This pointer may only be safely dereferenced as long as a valid reference
  * to the unpcb is held.  Typically, this reference will be from the socket,
  * or from another unpcb when the referring unpcb's lock is held (in order
  * that the reference not be invalidated during use).  For example, to follow
  * unp->unp_conn->unp_socket, you need to hold a lock on unp_conn to guarantee
  * that detach is not run clearing unp_socket.
  *
  * Blocking with UNIX domain sockets is a tricky issue: unlike most network
  * protocols, bind() is a non-atomic operation, and connect() requires
  * potential sleeping in the protocol, due to potentially waiting on local or
  * distributed file systems.  We try to separate "lookup" operations, which
  * may sleep, and the IPC operations themselves, which typically can occur
  * with relative atomicity as locks can be held over the entire operation.
  *
  * Another tricky issue is simultaneous multi-threaded or multi-process
  * access to a single UNIX domain socket.  These are handled by the flags
  * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or
  * binding, both of which involve dropping UNIX domain socket locks in order
  * to perform namei() and other file system operations.
  */
 static struct rwlock	unp_link_rwlock;
 static struct mtx	unp_defers_lock;
 
 #define	UNP_LINK_LOCK_INIT()		rw_init(&unp_link_rwlock,	\
 					    "unp_link_rwlock")
 
 #define	UNP_LINK_LOCK_ASSERT()		rw_assert(&unp_link_rwlock,	\
 					    RA_LOCKED)
 #define	UNP_LINK_UNLOCK_ASSERT()	rw_assert(&unp_link_rwlock,	\
 					    RA_UNLOCKED)
 
 #define	UNP_LINK_RLOCK()		rw_rlock(&unp_link_rwlock)
 #define	UNP_LINK_RUNLOCK()		rw_runlock(&unp_link_rwlock)
 #define	UNP_LINK_WLOCK()		rw_wlock(&unp_link_rwlock)
 #define	UNP_LINK_WUNLOCK()		rw_wunlock(&unp_link_rwlock)
 #define	UNP_LINK_WLOCK_ASSERT()		rw_assert(&unp_link_rwlock,	\
 					    RA_WLOCKED)
 #define	UNP_LINK_WOWNED()		rw_wowned(&unp_link_rwlock)
 
 #define	UNP_DEFERRED_LOCK_INIT()	mtx_init(&unp_defers_lock, \
 					    "unp_defer", NULL, MTX_DEF)
 #define	UNP_DEFERRED_LOCK()		mtx_lock(&unp_defers_lock)
 #define	UNP_DEFERRED_UNLOCK()		mtx_unlock(&unp_defers_lock)
 
 #define UNP_REF_LIST_LOCK()		UNP_DEFERRED_LOCK();
 #define UNP_REF_LIST_UNLOCK()		UNP_DEFERRED_UNLOCK();
 
 #define UNP_PCB_LOCK_INIT(unp)		mtx_init(&(unp)->unp_mtx,	\
 					    "unp", "unp",	\
 					    MTX_DUPOK|MTX_DEF)
 #define	UNP_PCB_LOCK_DESTROY(unp)	mtx_destroy(&(unp)->unp_mtx)
 #define	UNP_PCB_LOCKPTR(unp)		(&(unp)->unp_mtx)
 #define	UNP_PCB_LOCK(unp)		mtx_lock(&(unp)->unp_mtx)
 #define	UNP_PCB_TRYLOCK(unp)		mtx_trylock(&(unp)->unp_mtx)
 #define	UNP_PCB_UNLOCK(unp)		mtx_unlock(&(unp)->unp_mtx)
 #define	UNP_PCB_OWNED(unp)		mtx_owned(&(unp)->unp_mtx)
 #define	UNP_PCB_LOCK_ASSERT(unp)	mtx_assert(&(unp)->unp_mtx, MA_OWNED)
 #define	UNP_PCB_UNLOCK_ASSERT(unp)	mtx_assert(&(unp)->unp_mtx, MA_NOTOWNED)
 
 static int	uipc_connect2(struct socket *, struct socket *);
 static int	uipc_ctloutput(struct socket *, struct sockopt *);
 static int	unp_connect(struct socket *, struct sockaddr *,
 		    struct thread *);
 static int	unp_connectat(int, struct socket *, struct sockaddr *,
 		    struct thread *);
 static int	unp_connect2(struct socket *so, struct socket *so2, int);
 static void	unp_disconnect(struct unpcb *unp, struct unpcb *unp2);
 static void	unp_dispose(struct socket *so);
 static void	unp_dispose_mbuf(struct mbuf *);
 static void	unp_shutdown(struct unpcb *);
 static void	unp_drop(struct unpcb *);
 static void	unp_gc(__unused void *, int);
 static void	unp_scan(struct mbuf *, void (*)(struct filedescent **, int));
 static void	unp_discard(struct file *);
 static void	unp_freerights(struct filedescent **, int);
 static void	unp_init(void);
 static int	unp_internalize(struct mbuf **, struct thread *);
 static void	unp_internalize_fp(struct file *);
 static int	unp_externalize(struct mbuf *, struct mbuf **, int);
 static int	unp_externalize_fp(struct file *);
 static struct mbuf	*unp_addsockcred(struct thread *, struct mbuf *, int);
 static void	unp_process_defers(void * __unused, int);
 
 static void
 unp_pcb_hold(struct unpcb *unp)
 {
 	u_int old __unused;
 
 	old = refcount_acquire(&unp->unp_refcount);
 	KASSERT(old > 0, ("%s: unpcb %p has no references", __func__, unp));
 }
 
 static __result_use_check bool
 unp_pcb_rele(struct unpcb *unp)
 {
 	bool ret;
 
 	UNP_PCB_LOCK_ASSERT(unp);
 
 	if ((ret = refcount_release(&unp->unp_refcount))) {
 		UNP_PCB_UNLOCK(unp);
 		UNP_PCB_LOCK_DESTROY(unp);
 		uma_zfree(unp_zone, unp);
 	}
 	return (ret);
 }
 
 static void
 unp_pcb_rele_notlast(struct unpcb *unp)
 {
 	bool ret __unused;
 
 	ret = refcount_release(&unp->unp_refcount);
 	KASSERT(!ret, ("%s: unpcb %p has no references", __func__, unp));
 }
 
 static void
 unp_pcb_lock_pair(struct unpcb *unp, struct unpcb *unp2)
 {
 	UNP_PCB_UNLOCK_ASSERT(unp);
 	UNP_PCB_UNLOCK_ASSERT(unp2);
 
 	if (unp == unp2) {
 		UNP_PCB_LOCK(unp);
 	} else if ((uintptr_t)unp2 > (uintptr_t)unp) {
 		UNP_PCB_LOCK(unp);
 		UNP_PCB_LOCK(unp2);
 	} else {
 		UNP_PCB_LOCK(unp2);
 		UNP_PCB_LOCK(unp);
 	}
 }
 
 static void
 unp_pcb_unlock_pair(struct unpcb *unp, struct unpcb *unp2)
 {
 	UNP_PCB_UNLOCK(unp);
 	if (unp != unp2)
 		UNP_PCB_UNLOCK(unp2);
 }
 
 /*
  * Try to lock the connected peer of an already locked socket.  In some cases
  * this requires that we unlock the current socket.  The pairbusy counter is
  * used to block concurrent connection attempts while the lock is dropped.  The
  * caller must be careful to revalidate PCB state.
  */
 static struct unpcb *
 unp_pcb_lock_peer(struct unpcb *unp)
 {
 	struct unpcb *unp2;
 
 	UNP_PCB_LOCK_ASSERT(unp);
 	unp2 = unp->unp_conn;
 	if (unp2 == NULL)
 		return (NULL);
 	if (__predict_false(unp == unp2))
 		return (unp);
 
 	UNP_PCB_UNLOCK_ASSERT(unp2);
 
 	if (__predict_true(UNP_PCB_TRYLOCK(unp2)))
 		return (unp2);
 	if ((uintptr_t)unp2 > (uintptr_t)unp) {
 		UNP_PCB_LOCK(unp2);
 		return (unp2);
 	}
 	unp->unp_pairbusy++;
 	unp_pcb_hold(unp2);
 	UNP_PCB_UNLOCK(unp);
 
 	UNP_PCB_LOCK(unp2);
 	UNP_PCB_LOCK(unp);
 	KASSERT(unp->unp_conn == unp2 || unp->unp_conn == NULL,
 	    ("%s: socket %p was reconnected", __func__, unp));
 	if (--unp->unp_pairbusy == 0 && (unp->unp_flags & UNP_WAITING) != 0) {
 		unp->unp_flags &= ~UNP_WAITING;
 		wakeup(unp);
 	}
 	if (unp_pcb_rele(unp2)) {
 		/* unp2 is unlocked. */
 		return (NULL);
 	}
 	if (unp->unp_conn == NULL) {
 		UNP_PCB_UNLOCK(unp2);
 		return (NULL);
 	}
 	return (unp2);
 }
 
 /*
  * Definitions of protocols supported in the LOCAL domain.
  */
 static struct domain localdomain;
 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream;
 static struct pr_usrreqs uipc_usrreqs_seqpacket;
 static struct protosw localsw[] = {
 {
 	.pr_type =		SOCK_STREAM,
 	.pr_domain =		&localdomain,
 	.pr_flags =		PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS,
 	.pr_ctloutput =		&uipc_ctloutput,
 	.pr_usrreqs =		&uipc_usrreqs_stream
 },
 {
 	.pr_type =		SOCK_DGRAM,
 	.pr_domain =		&localdomain,
 	.pr_flags =		PR_ATOMIC|PR_ADDR|PR_RIGHTS,
 	.pr_ctloutput =		&uipc_ctloutput,
 	.pr_usrreqs =		&uipc_usrreqs_dgram
 },
 {
 	.pr_type =		SOCK_SEQPACKET,
 	.pr_domain =		&localdomain,
 
 	/*
 	 * XXXRW: For now, PR_ADDR because soreceive will bump into them
 	 * due to our use of sbappendaddr.  A new sbappend variants is needed
 	 * that supports both atomic record writes and control data.
 	 */
 	.pr_flags =		PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD|
 				    PR_RIGHTS,
 	.pr_ctloutput =		&uipc_ctloutput,
 	.pr_usrreqs =		&uipc_usrreqs_seqpacket,
 },
 };
 
 static struct domain localdomain = {
 	.dom_family =		AF_LOCAL,
 	.dom_name =		"local",
 	.dom_init =		unp_init,
 	.dom_externalize =	unp_externalize,
 	.dom_dispose =		unp_dispose,
 	.dom_protosw =		localsw,
 	.dom_protoswNPROTOSW =	&localsw[nitems(localsw)]
 };
 DOMAIN_SET(local);
 
 static void
 uipc_abort(struct socket *so)
 {
 	struct unpcb *unp, *unp2;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
 	UNP_PCB_UNLOCK_ASSERT(unp);
 
 	UNP_PCB_LOCK(unp);
 	unp2 = unp->unp_conn;
 	if (unp2 != NULL) {
 		unp_pcb_hold(unp2);
 		UNP_PCB_UNLOCK(unp);
 		unp_drop(unp2);
 	} else
 		UNP_PCB_UNLOCK(unp);
 }
 
 static int
 uipc_accept(struct socket *so, struct sockaddr **nam)
 {
 	struct unpcb *unp, *unp2;
 	const struct sockaddr *sa;
 
 	/*
 	 * Pass back name of connected socket, if it was bound and we are
 	 * still connected (our peer may have closed already!).
 	 */
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_accept: unp == NULL"));
 
 	*nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 	UNP_PCB_LOCK(unp);
 	unp2 = unp_pcb_lock_peer(unp);
 	if (unp2 != NULL && unp2->unp_addr != NULL)
 		sa = (struct sockaddr *)unp2->unp_addr;
 	else
 		sa = &sun_noname;
 	bcopy(sa, *nam, sa->sa_len);
 	if (unp2 != NULL)
 		unp_pcb_unlock_pair(unp, unp2);
 	else
 		UNP_PCB_UNLOCK(unp);
 	return (0);
 }
 
 static int
 uipc_attach(struct socket *so, int proto, struct thread *td)
 {
 	u_long sendspace, recvspace;
 	struct unpcb *unp;
 	int error;
 	bool locked;
 
 	KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
 	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 		switch (so->so_type) {
 		case SOCK_STREAM:
 			sendspace = unpst_sendspace;
 			recvspace = unpst_recvspace;
 			break;
 
 		case SOCK_DGRAM:
 			sendspace = unpdg_sendspace;
 			recvspace = unpdg_recvspace;
 			break;
 
 		case SOCK_SEQPACKET:
 			sendspace = unpsp_sendspace;
 			recvspace = unpsp_recvspace;
 			break;
 
 		default:
 			panic("uipc_attach");
 		}
 		error = soreserve(so, sendspace, recvspace);
 		if (error)
 			return (error);
 	}
 	unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
 	if (unp == NULL)
 		return (ENOBUFS);
 	LIST_INIT(&unp->unp_refs);
 	UNP_PCB_LOCK_INIT(unp);
 	unp->unp_socket = so;
 	so->so_pcb = unp;
 	refcount_init(&unp->unp_refcount, 1);
 
 	if ((locked = UNP_LINK_WOWNED()) == false)
 		UNP_LINK_WLOCK();
 
 	unp->unp_gencnt = ++unp_gencnt;
 	unp->unp_ino = ++unp_ino;
 	unp_count++;
 	switch (so->so_type) {
 	case SOCK_STREAM:
 		LIST_INSERT_HEAD(&unp_shead, unp, unp_link);
 		break;
 
 	case SOCK_DGRAM:
 		LIST_INSERT_HEAD(&unp_dhead, unp, unp_link);
 		break;
 
 	case SOCK_SEQPACKET:
 		LIST_INSERT_HEAD(&unp_sphead, unp, unp_link);
 		break;
 
 	default:
 		panic("uipc_attach");
 	}
 
 	if (locked == false)
 		UNP_LINK_WUNLOCK();
 
 	return (0);
 }
 
 static int
 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
 {
 	struct sockaddr_un *soun = (struct sockaddr_un *)nam;
 	struct vattr vattr;
 	int error, namelen;
 	struct nameidata nd;
 	struct unpcb *unp;
 	struct vnode *vp;
 	struct mount *mp;
 	cap_rights_t rights;
 	char *buf;
 
 	if (nam->sa_family != AF_UNIX)
 		return (EAFNOSUPPORT);
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
 
 	if (soun->sun_len > sizeof(struct sockaddr_un))
 		return (EINVAL);
 	namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
 	if (namelen <= 0)
 		return (EINVAL);
 
 	/*
 	 * We don't allow simultaneous bind() calls on a single UNIX domain
 	 * socket, so flag in-progress operations, and return an error if an
 	 * operation is already in progress.
 	 *
 	 * Historically, we have not allowed a socket to be rebound, so this
 	 * also returns an error.  Not allowing re-binding simplifies the
 	 * implementation and avoids a great many possible failure modes.
 	 */
 	UNP_PCB_LOCK(unp);
 	if (unp->unp_vnode != NULL) {
 		UNP_PCB_UNLOCK(unp);
 		return (EINVAL);
 	}
 	if (unp->unp_flags & UNP_BINDING) {
 		UNP_PCB_UNLOCK(unp);
 		return (EALREADY);
 	}
 	unp->unp_flags |= UNP_BINDING;
 	UNP_PCB_UNLOCK(unp);
 
 	buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
 	bcopy(soun->sun_path, buf, namelen);
 	buf[namelen] = 0;
 
 restart:
 	NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE,
 	    UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_BINDAT),
 	    td);
 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
 	error = namei(&nd);
 	if (error)
 		goto error;
 	vp = nd.ni_vp;
 	if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 		NDFREE(&nd, NDF_ONLY_PNBUF);
 		if (nd.ni_dvp == vp)
 			vrele(nd.ni_dvp);
 		else
 			vput(nd.ni_dvp);
 		if (vp != NULL) {
 			vrele(vp);
 			error = EADDRINUSE;
 			goto error;
 		}
 		error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
 		if (error)
 			goto error;
 		goto restart;
 	}
 	VATTR_NULL(&vattr);
 	vattr.va_type = VSOCK;
 	vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_pd->pd_cmask);
 #ifdef MAC
 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 	    &vattr);
 #endif
 	if (error == 0)
 		error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
 	NDFREE(&nd, NDF_ONLY_PNBUF);
 	if (error) {
 		VOP_VPUT_PAIR(nd.ni_dvp, NULL, true);
 		vn_finished_write(mp);
 		if (error == ERELOOKUP)
 			goto restart;
 		goto error;
 	}
 	vp = nd.ni_vp;
 	ASSERT_VOP_ELOCKED(vp, "uipc_bind");
 	soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
 
 	UNP_PCB_LOCK(unp);
 	VOP_UNP_BIND(vp, unp);
 	unp->unp_vnode = vp;
 	unp->unp_addr = soun;
 	unp->unp_flags &= ~UNP_BINDING;
 	UNP_PCB_UNLOCK(unp);
 	vref(vp);
 	VOP_VPUT_PAIR(nd.ni_dvp, &vp, true);
 	vn_finished_write(mp);
 	free(buf, M_TEMP);
 	return (0);
 
 error:
 	UNP_PCB_LOCK(unp);
 	unp->unp_flags &= ~UNP_BINDING;
 	UNP_PCB_UNLOCK(unp);
 	free(buf, M_TEMP);
 	return (error);
 }
 
 static int
 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 {
 
 	return (uipc_bindat(AT_FDCWD, so, nam, td));
 }
 
 static int
 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 {
 	int error;
 
 	KASSERT(td == curthread, ("uipc_connect: td != curthread"));
 	error = unp_connect(so, nam, td);
 	return (error);
 }
 
 static int
 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam,
     struct thread *td)
 {
 	int error;
 
 	KASSERT(td == curthread, ("uipc_connectat: td != curthread"));
 	error = unp_connectat(fd, so, nam, td);
 	return (error);
 }
 
 static void
 uipc_close(struct socket *so)
 {
 	struct unpcb *unp, *unp2;
 	struct vnode *vp = NULL;
 	struct mtx *vplock;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
 
 	vplock = NULL;
 	if ((vp = unp->unp_vnode) != NULL) {
 		vplock = mtx_pool_find(mtxpool_sleep, vp);
 		mtx_lock(vplock);
 	}
 	UNP_PCB_LOCK(unp);
 	if (vp && unp->unp_vnode == NULL) {
 		mtx_unlock(vplock);
 		vp = NULL;
 	}
 	if (vp != NULL) {
 		VOP_UNP_DETACH(vp);
 		unp->unp_vnode = NULL;
 	}
 	if ((unp2 = unp_pcb_lock_peer(unp)) != NULL)
 		unp_disconnect(unp, unp2);
 	else
 		UNP_PCB_UNLOCK(unp);
 	if (vp) {
 		mtx_unlock(vplock);
 		vrele(vp);
 	}
 }
 
 static int
 uipc_connect2(struct socket *so1, struct socket *so2)
 {
 	struct unpcb *unp, *unp2;
 	int error;
 
 	unp = so1->so_pcb;
 	KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
 	unp2 = so2->so_pcb;
 	KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
 	unp_pcb_lock_pair(unp, unp2);
 	error = unp_connect2(so1, so2, PRU_CONNECT2);
 	unp_pcb_unlock_pair(unp, unp2);
 	return (error);
 }
 
 static void
 uipc_detach(struct socket *so)
 {
 	struct unpcb *unp, *unp2;
 	struct mtx *vplock;
 	struct vnode *vp;
 	int local_unp_rights;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
 
 	vp = NULL;
 	vplock = NULL;
 
 	SOCK_LOCK(so);
 	if (!SOLISTENING(so)) {
 		/*
 		 * Once the socket is removed from the global lists,
 		 * uipc_ready() will not be able to locate its socket buffer, so
 		 * clear the buffer now.  At this point internalized rights have
 		 * already been disposed of.
 		 */
 		sbrelease(&so->so_rcv, so);
 	}
 	SOCK_UNLOCK(so);
 
 	UNP_LINK_WLOCK();
 	LIST_REMOVE(unp, unp_link);
 	if (unp->unp_gcflag & UNPGC_DEAD)
 		LIST_REMOVE(unp, unp_dead);
 	unp->unp_gencnt = ++unp_gencnt;
 	--unp_count;
 	UNP_LINK_WUNLOCK();
 
 	UNP_PCB_UNLOCK_ASSERT(unp);
  restart:
 	if ((vp = unp->unp_vnode) != NULL) {
 		vplock = mtx_pool_find(mtxpool_sleep, vp);
 		mtx_lock(vplock);
 	}
 	UNP_PCB_LOCK(unp);
 	if (unp->unp_vnode != vp && unp->unp_vnode != NULL) {
 		if (vplock)
 			mtx_unlock(vplock);
 		UNP_PCB_UNLOCK(unp);
 		goto restart;
 	}
 	if ((vp = unp->unp_vnode) != NULL) {
 		VOP_UNP_DETACH(vp);
 		unp->unp_vnode = NULL;
 	}
 	if ((unp2 = unp_pcb_lock_peer(unp)) != NULL)
 		unp_disconnect(unp, unp2);
 	else
 		UNP_PCB_UNLOCK(unp);
 
 	UNP_REF_LIST_LOCK();
 	while (!LIST_EMPTY(&unp->unp_refs)) {
 		struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
 
 		unp_pcb_hold(ref);
 		UNP_REF_LIST_UNLOCK();
 
 		MPASS(ref != unp);
 		UNP_PCB_UNLOCK_ASSERT(ref);
 		unp_drop(ref);
 		UNP_REF_LIST_LOCK();
 	}
 	UNP_REF_LIST_UNLOCK();
 
 	UNP_PCB_LOCK(unp);
 	local_unp_rights = unp_rights;
 	unp->unp_socket->so_pcb = NULL;
 	unp->unp_socket = NULL;
 	free(unp->unp_addr, M_SONAME);
 	unp->unp_addr = NULL;
 	if (!unp_pcb_rele(unp))
 		UNP_PCB_UNLOCK(unp);
 	if (vp) {
 		mtx_unlock(vplock);
 		vrele(vp);
 	}
 	if (local_unp_rights)
 		taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1);
 }
 
 static int
 uipc_disconnect(struct socket *so)
 {
 	struct unpcb *unp, *unp2;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
 
 	UNP_PCB_LOCK(unp);
 	if ((unp2 = unp_pcb_lock_peer(unp)) != NULL)
 		unp_disconnect(unp, unp2);
 	else
 		UNP_PCB_UNLOCK(unp);
 	return (0);
 }
 
 static int
 uipc_listen(struct socket *so, int backlog, struct thread *td)
 {
 	struct unpcb *unp;
 	int error;
 
 	if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET)
 		return (EOPNOTSUPP);
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_listen: unp == NULL"));
 
 	UNP_PCB_LOCK(unp);
 	if (unp->unp_vnode == NULL) {
 		/* Already connected or not bound to an address. */
 		error = unp->unp_conn != NULL ? EINVAL : EDESTADDRREQ;
 		UNP_PCB_UNLOCK(unp);
 		return (error);
 	}
 
 	SOCK_LOCK(so);
 	error = solisten_proto_check(so);
 	if (error == 0) {
 		cru2xt(td, &unp->unp_peercred);
 		solisten_proto(so, backlog);
 	}
 	SOCK_UNLOCK(so);
 	UNP_PCB_UNLOCK(unp);
 	return (error);
 }
 
 static int
 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
 {
 	struct unpcb *unp, *unp2;
 	const struct sockaddr *sa;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
 
 	*nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 	UNP_LINK_RLOCK();
 	/*
 	 * XXX: It seems that this test always fails even when connection is
 	 * established.  So, this else clause is added as workaround to
 	 * return PF_LOCAL sockaddr.
 	 */
 	unp2 = unp->unp_conn;
 	if (unp2 != NULL) {
 		UNP_PCB_LOCK(unp2);
 		if (unp2->unp_addr != NULL)
 			sa = (struct sockaddr *) unp2->unp_addr;
 		else
 			sa = &sun_noname;
 		bcopy(sa, *nam, sa->sa_len);
 		UNP_PCB_UNLOCK(unp2);
 	} else {
 		sa = &sun_noname;
 		bcopy(sa, *nam, sa->sa_len);
 	}
 	UNP_LINK_RUNLOCK();
 	return (0);
 }
 
 static int
 uipc_rcvd(struct socket *so, int flags)
 {
 	struct unpcb *unp, *unp2;
 	struct socket *so2;
 	u_int mbcnt, sbcc;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("%s: unp == NULL", __func__));
 	KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET,
 	    ("%s: socktype %d", __func__, so->so_type));
 
 	/*
 	 * Adjust backpressure on sender and wakeup any waiting to write.
 	 *
 	 * The unp lock is acquired to maintain the validity of the unp_conn
 	 * pointer; no lock on unp2 is required as unp2->unp_socket will be
 	 * static as long as we don't permit unp2 to disconnect from unp,
 	 * which is prevented by the lock on unp.  We cache values from
 	 * so_rcv to avoid holding the so_rcv lock over the entire
 	 * transaction on the remote so_snd.
 	 */
 	SOCKBUF_LOCK(&so->so_rcv);
 	mbcnt = so->so_rcv.sb_mbcnt;
 	sbcc = sbavail(&so->so_rcv);
 	SOCKBUF_UNLOCK(&so->so_rcv);
 	/*
 	 * There is a benign race condition at this point.  If we're planning to
 	 * clear SB_STOP, but uipc_send is called on the connected socket at
 	 * this instant, it might add data to the sockbuf and set SB_STOP.  Then
 	 * we would erroneously clear SB_STOP below, even though the sockbuf is
 	 * full.  The race is benign because the only ill effect is to allow the
 	 * sockbuf to exceed its size limit, and the size limits are not
 	 * strictly guaranteed anyway.
 	 */
 	UNP_PCB_LOCK(unp);
 	unp2 = unp->unp_conn;
 	if (unp2 == NULL) {
 		UNP_PCB_UNLOCK(unp);
 		return (0);
 	}
 	so2 = unp2->unp_socket;
 	SOCKBUF_LOCK(&so2->so_snd);
 	if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax)
 		so2->so_snd.sb_flags &= ~SB_STOP;
 	sowwakeup_locked(so2);
 	UNP_PCB_UNLOCK(unp);
 	return (0);
 }
 
 static int
 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
     struct mbuf *control, struct thread *td)
 {
 	struct unpcb *unp, *unp2;
 	struct socket *so2;
 	u_int mbcnt, sbcc;
 	int freed, error;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("%s: unp == NULL", __func__));
 	KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM ||
 	    so->so_type == SOCK_SEQPACKET,
 	    ("%s: socktype %d", __func__, so->so_type));
 
 	freed = error = 0;
 	if (flags & PRUS_OOB) {
 		error = EOPNOTSUPP;
 		goto release;
 	}
 	if (control != NULL && (error = unp_internalize(&control, td)))
 		goto release;
 
 	unp2 = NULL;
 	switch (so->so_type) {
 	case SOCK_DGRAM:
 	{
 		const struct sockaddr *from;
 
 		if (nam != NULL) {
 			error = unp_connect(so, nam, td);
 			if (error != 0)
 				break;
 		}
 		UNP_PCB_LOCK(unp);
 
 		/*
 		 * Because connect() and send() are non-atomic in a sendto()
 		 * with a target address, it's possible that the socket will
 		 * have disconnected before the send() can run.  In that case
 		 * return the slightly counter-intuitive but otherwise
 		 * correct error that the socket is not connected.
 		 */
 		unp2 = unp_pcb_lock_peer(unp);
 		if (unp2 == NULL) {
 			UNP_PCB_UNLOCK(unp);
 			error = ENOTCONN;
 			break;
 		}
 
 		if (unp2->unp_flags & UNP_WANTCRED_MASK)
 			control = unp_addsockcred(td, control,
 			    unp2->unp_flags);
 		if (unp->unp_addr != NULL)
 			from = (struct sockaddr *)unp->unp_addr;
 		else
 			from = &sun_noname;
 		so2 = unp2->unp_socket;
 		SOCKBUF_LOCK(&so2->so_rcv);
 		if (sbappendaddr_locked(&so2->so_rcv, from, m,
 		    control)) {
 			sorwakeup_locked(so2);
 			m = NULL;
 			control = NULL;
 		} else {
 			SOCKBUF_UNLOCK(&so2->so_rcv);
 			error = ENOBUFS;
 		}
 		if (nam != NULL)
 			unp_disconnect(unp, unp2);
 		else
 			unp_pcb_unlock_pair(unp, unp2);
 		break;
 	}
 
 	case SOCK_SEQPACKET:
 	case SOCK_STREAM:
 		if ((so->so_state & SS_ISCONNECTED) == 0) {
 			if (nam != NULL) {
 				error = unp_connect(so, nam, td);
 				if (error != 0)
 					break;
 			} else {
 				error = ENOTCONN;
 				break;
 			}
 		}
 
 		UNP_PCB_LOCK(unp);
 		if ((unp2 = unp_pcb_lock_peer(unp)) == NULL) {
 			UNP_PCB_UNLOCK(unp);
 			error = ENOTCONN;
 			break;
 		} else if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
 			unp_pcb_unlock_pair(unp, unp2);
 			error = EPIPE;
 			break;
 		}
 		UNP_PCB_UNLOCK(unp);
 		if ((so2 = unp2->unp_socket) == NULL) {
 			UNP_PCB_UNLOCK(unp2);
 			error = ENOTCONN;
 			break;
 		}
 		SOCKBUF_LOCK(&so2->so_rcv);
 		if (unp2->unp_flags & UNP_WANTCRED_MASK) {
 			/*
 			 * Credentials are passed only once on SOCK_STREAM and
 			 * SOCK_SEQPACKET (LOCAL_CREDS => WANTCRED_ONESHOT), or
 			 * forever (LOCAL_CREDS_PERSISTENT => WANTCRED_ALWAYS).
 			 */
 			control = unp_addsockcred(td, control, unp2->unp_flags);
 			unp2->unp_flags &= ~UNP_WANTCRED_ONESHOT;
 		}
 
 		/*
 		 * Send to paired receive port and wake up readers.  Don't
 		 * check for space available in the receive buffer if we're
 		 * attaching ancillary data; Unix domain sockets only check
 		 * for space in the sending sockbuf, and that check is
 		 * performed one level up the stack.  At that level we cannot
 		 * precisely account for the amount of buffer space used
 		 * (e.g., because control messages are not yet internalized).
 		 */
 		switch (so->so_type) {
 		case SOCK_STREAM:
 			if (control != NULL) {
 				sbappendcontrol_locked(&so2->so_rcv, m,
 				    control, flags);
 				control = NULL;
 			} else
 				sbappend_locked(&so2->so_rcv, m, flags);
 			break;
 
 		case SOCK_SEQPACKET:
 			if (sbappendaddr_nospacecheck_locked(&so2->so_rcv,
 			    &sun_noname, m, control))
 				control = NULL;
 			break;
 		}
 
 		mbcnt = so2->so_rcv.sb_mbcnt;
 		sbcc = sbavail(&so2->so_rcv);
 		if (sbcc)
 			sorwakeup_locked(so2);
 		else
 			SOCKBUF_UNLOCK(&so2->so_rcv);
 
 		/*
 		 * The PCB lock on unp2 protects the SB_STOP flag.  Without it,
 		 * it would be possible for uipc_rcvd to be called at this
 		 * point, drain the receiving sockbuf, clear SB_STOP, and then
 		 * we would set SB_STOP below.  That could lead to an empty
 		 * sockbuf having SB_STOP set
 		 */
 		SOCKBUF_LOCK(&so->so_snd);
 		if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax)
 			so->so_snd.sb_flags |= SB_STOP;
 		SOCKBUF_UNLOCK(&so->so_snd);
 		UNP_PCB_UNLOCK(unp2);
 		m = NULL;
 		break;
 	}
 
 	/*
 	 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown.
 	 */
 	if (flags & PRUS_EOF) {
 		UNP_PCB_LOCK(unp);
 		socantsendmore(so);
 		unp_shutdown(unp);
 		UNP_PCB_UNLOCK(unp);
 	}
 	if (control != NULL && error != 0)
 		unp_dispose_mbuf(control);
 
 release:
 	if (control != NULL)
 		m_freem(control);
 	/*
 	 * In case of PRUS_NOTREADY, uipc_ready() is responsible
 	 * for freeing memory.
 	 */   
 	if (m != NULL && (flags & PRUS_NOTREADY) == 0)
 		m_freem(m);
 	return (error);
 }
 
 static bool
 uipc_ready_scan(struct socket *so, struct mbuf *m, int count, int *errorp)
 {
 	struct mbuf *mb, *n;
 	struct sockbuf *sb;
 
 	SOCK_LOCK(so);
 	if (SOLISTENING(so)) {
 		SOCK_UNLOCK(so);
 		return (false);
 	}
 	mb = NULL;
 	sb = &so->so_rcv;
 	SOCKBUF_LOCK(sb);
 	if (sb->sb_fnrdy != NULL) {
 		for (mb = sb->sb_mb, n = mb->m_nextpkt; mb != NULL;) {
 			if (mb == m) {
 				*errorp = sbready(sb, m, count);
 				break;
 			}
 			mb = mb->m_next;
 			if (mb == NULL) {
 				mb = n;
 				if (mb != NULL)
 					n = mb->m_nextpkt;
 			}
 		}
 	}
 	SOCKBUF_UNLOCK(sb);
 	SOCK_UNLOCK(so);
 	return (mb != NULL);
 }
 
 static int
 uipc_ready(struct socket *so, struct mbuf *m, int count)
 {
 	struct unpcb *unp, *unp2;
 	struct socket *so2;
 	int error, i;
 
 	unp = sotounpcb(so);
 
 	KASSERT(so->so_type == SOCK_STREAM,
 	    ("%s: unexpected socket type for %p", __func__, so));
 
 	UNP_PCB_LOCK(unp);
 	if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) {
 		UNP_PCB_UNLOCK(unp);
 		so2 = unp2->unp_socket;
 		SOCKBUF_LOCK(&so2->so_rcv);
 		if ((error = sbready(&so2->so_rcv, m, count)) == 0)
 			sorwakeup_locked(so2);
 		else
 			SOCKBUF_UNLOCK(&so2->so_rcv);
 		UNP_PCB_UNLOCK(unp2);
 		return (error);
 	}
 	UNP_PCB_UNLOCK(unp);
 
 	/*
 	 * The receiving socket has been disconnected, but may still be valid.
 	 * In this case, the now-ready mbufs are still present in its socket
 	 * buffer, so perform an exhaustive search before giving up and freeing
 	 * the mbufs.
 	 */
 	UNP_LINK_RLOCK();
 	LIST_FOREACH(unp, &unp_shead, unp_link) {
 		if (uipc_ready_scan(unp->unp_socket, m, count, &error))
 			break;
 	}
 	UNP_LINK_RUNLOCK();
 
 	if (unp == NULL) {
 		for (i = 0; i < count; i++)
 			m = m_free(m);
 		error = ECONNRESET;
 	}
 	return (error);
 }
 
 static int
 uipc_sense(struct socket *so, struct stat *sb)
 {
 	struct unpcb *unp;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
 
 	sb->st_blksize = so->so_snd.sb_hiwat;
 	sb->st_dev = NODEV;
 	sb->st_ino = unp->unp_ino;
 	return (0);
 }
 
 static int
 uipc_shutdown(struct socket *so)
 {
 	struct unpcb *unp;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL"));
 
 	UNP_PCB_LOCK(unp);
 	socantsendmore(so);
 	unp_shutdown(unp);
 	UNP_PCB_UNLOCK(unp);
 	return (0);
 }
 
 static int
 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
 {
 	struct unpcb *unp;
 	const struct sockaddr *sa;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
 
 	*nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 	UNP_PCB_LOCK(unp);
 	if (unp->unp_addr != NULL)
 		sa = (struct sockaddr *) unp->unp_addr;
 	else
 		sa = &sun_noname;
 	bcopy(sa, *nam, sa->sa_len);
 	UNP_PCB_UNLOCK(unp);
 	return (0);
 }
 
 static struct pr_usrreqs uipc_usrreqs_dgram = {
 	.pru_abort = 		uipc_abort,
 	.pru_accept =		uipc_accept,
 	.pru_attach =		uipc_attach,
 	.pru_bind =		uipc_bind,
 	.pru_bindat =		uipc_bindat,
 	.pru_connect =		uipc_connect,
 	.pru_connectat =	uipc_connectat,
 	.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_soreceive =	soreceive_dgram,
 	.pru_close =		uipc_close,
 };
 
 static struct pr_usrreqs uipc_usrreqs_seqpacket = {
 	.pru_abort =		uipc_abort,
 	.pru_accept =		uipc_accept,
 	.pru_attach =		uipc_attach,
 	.pru_bind =		uipc_bind,
 	.pru_bindat =		uipc_bindat,
 	.pru_connect =		uipc_connect,
 	.pru_connectat =	uipc_connectat,
 	.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_soreceive =	soreceive_generic,	/* XXX: or...? */
 	.pru_close =		uipc_close,
 };
 
 static struct pr_usrreqs uipc_usrreqs_stream = {
 	.pru_abort = 		uipc_abort,
 	.pru_accept =		uipc_accept,
 	.pru_attach =		uipc_attach,
 	.pru_bind =		uipc_bind,
 	.pru_bindat =		uipc_bindat,
 	.pru_connect =		uipc_connect,
 	.pru_connectat =	uipc_connectat,
 	.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_ready =		uipc_ready,
 	.pru_sense =		uipc_sense,
 	.pru_shutdown =		uipc_shutdown,
 	.pru_sockaddr =		uipc_sockaddr,
 	.pru_soreceive =	soreceive_generic,
 	.pru_close =		uipc_close,
 };
 
 static int
 uipc_ctloutput(struct socket *so, struct sockopt *sopt)
 {
 	struct unpcb *unp;
 	struct xucred xu;
 	int error, optval;
 
 	if (sopt->sopt_level != SOL_LOCAL)
 		return (EINVAL);
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
 	error = 0;
 	switch (sopt->sopt_dir) {
 	case SOPT_GET:
 		switch (sopt->sopt_name) {
 		case LOCAL_PEERCRED:
 			UNP_PCB_LOCK(unp);
 			if (unp->unp_flags & UNP_HAVEPC)
 				xu = unp->unp_peercred;
 			else {
 				if (so->so_type == SOCK_STREAM)
 					error = ENOTCONN;
 				else
 					error = EINVAL;
 			}
 			UNP_PCB_UNLOCK(unp);
 			if (error == 0)
 				error = sooptcopyout(sopt, &xu, sizeof(xu));
 			break;
 
 		case LOCAL_CREDS:
 			/* Unlocked read. */
 			optval = unp->unp_flags & UNP_WANTCRED_ONESHOT ? 1 : 0;
 			error = sooptcopyout(sopt, &optval, sizeof(optval));
 			break;
 
 		case LOCAL_CREDS_PERSISTENT:
 			/* Unlocked read. */
 			optval = unp->unp_flags & UNP_WANTCRED_ALWAYS ? 1 : 0;
 			error = sooptcopyout(sopt, &optval, sizeof(optval));
 			break;
 
 		case LOCAL_CONNWAIT:
 			/* Unlocked read. */
 			optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0;
 			error = sooptcopyout(sopt, &optval, sizeof(optval));
 			break;
 
 		default:
 			error = EOPNOTSUPP;
 			break;
 		}
 		break;
 
 	case SOPT_SET:
 		switch (sopt->sopt_name) {
 		case LOCAL_CREDS:
 		case LOCAL_CREDS_PERSISTENT:
 		case LOCAL_CONNWAIT:
 			error = sooptcopyin(sopt, &optval, sizeof(optval),
 					    sizeof(optval));
 			if (error)
 				break;
 
 #define	OPTSET(bit, exclusive) do {					\
 	UNP_PCB_LOCK(unp);						\
 	if (optval) {							\
 		if ((unp->unp_flags & (exclusive)) != 0) {		\
 			UNP_PCB_UNLOCK(unp);				\
 			error = EINVAL;					\
 			break;						\
 		}							\
 		unp->unp_flags |= (bit);				\
 	} else								\
 		unp->unp_flags &= ~(bit);				\
 	UNP_PCB_UNLOCK(unp);						\
 } while (0)
 
 			switch (sopt->sopt_name) {
 			case LOCAL_CREDS:
 				OPTSET(UNP_WANTCRED_ONESHOT, UNP_WANTCRED_ALWAYS);
 				break;
 
 			case LOCAL_CREDS_PERSISTENT:
 				OPTSET(UNP_WANTCRED_ALWAYS, UNP_WANTCRED_ONESHOT);
 				break;
 
 			case LOCAL_CONNWAIT:
 				OPTSET(UNP_CONNWAIT, 0);
 				break;
 
 			default:
 				break;
 			}
 			break;
 #undef	OPTSET
 		default:
 			error = ENOPROTOOPT;
 			break;
 		}
 		break;
 
 	default:
 		error = EOPNOTSUPP;
 		break;
 	}
 	return (error);
 }
 
 static int
 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 {
 
 	return (unp_connectat(AT_FDCWD, so, nam, td));
 }
 
 static int
 unp_connectat(int fd, struct socket *so, struct sockaddr *nam,
     struct thread *td)
 {
 	struct mtx *vplock;
 	struct sockaddr_un *soun;
 	struct vnode *vp;
 	struct socket *so2;
 	struct unpcb *unp, *unp2, *unp3;
 	struct nameidata nd;
 	char buf[SOCK_MAXADDRLEN];
 	struct sockaddr *sa;
 	cap_rights_t rights;
 	int error, len;
 	bool connreq;
 
 	if (nam->sa_family != AF_UNIX)
 		return (EAFNOSUPPORT);
 	if (nam->sa_len > sizeof(struct sockaddr_un))
 		return (EINVAL);
 	len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
 	if (len <= 0)
 		return (EINVAL);
 	soun = (struct sockaddr_un *)nam;
 	bcopy(soun->sun_path, buf, len);
 	buf[len] = 0;
 
 	unp = sotounpcb(so);
 	UNP_PCB_LOCK(unp);
 	for (;;) {
 		/*
 		 * Wait for connection state to stabilize.  If a connection
 		 * already exists, give up.  For datagram sockets, which permit
 		 * multiple consecutive connect(2) calls, upper layers are
 		 * responsible for disconnecting in advance of a subsequent
 		 * connect(2), but this is not synchronized with PCB connection
 		 * state.
 		 *
 		 * Also make sure that no threads are currently attempting to
 		 * lock the peer socket, to ensure that unp_conn cannot
 		 * transition between two valid sockets while locks are dropped.
 		 */
 		if (unp->unp_conn != NULL) {
 			UNP_PCB_UNLOCK(unp);
 			return (EISCONN);
 		}
 		if ((unp->unp_flags & UNP_CONNECTING) != 0) {
 			UNP_PCB_UNLOCK(unp);
 			return (EALREADY);
 		}
 		if (unp->unp_pairbusy > 0) {
 			unp->unp_flags |= UNP_WAITING;
 			mtx_sleep(unp, UNP_PCB_LOCKPTR(unp), 0, "unpeer", 0);
 			continue;
 		}
 		break;
 	}
 	unp->unp_flags |= UNP_CONNECTING;
 	UNP_PCB_UNLOCK(unp);
 
 	connreq = (so->so_proto->pr_flags & PR_CONNREQUIRED) != 0;
 	if (connreq)
 		sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 	else
 		sa = NULL;
 	NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
 	    UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_CONNECTAT),
 	    td);
 	error = namei(&nd);
 	if (error)
 		vp = NULL;
 	else
 		vp = nd.ni_vp;
 	ASSERT_VOP_LOCKED(vp, "unp_connect");
 	NDFREE_NOTHING(&nd);
 	if (error)
 		goto bad;
 
 	if (vp->v_type != VSOCK) {
 		error = ENOTSOCK;
 		goto bad;
 	}
 #ifdef MAC
 	error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
 	if (error)
 		goto bad;
 #endif
 	error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
 	if (error)
 		goto bad;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
 
 	vplock = mtx_pool_find(mtxpool_sleep, vp);
 	mtx_lock(vplock);
 	VOP_UNP_CONNECT(vp, &unp2);
 	if (unp2 == NULL) {
 		error = ECONNREFUSED;
 		goto bad2;
 	}
 	so2 = unp2->unp_socket;
 	if (so->so_type != so2->so_type) {
 		error = EPROTOTYPE;
 		goto bad2;
 	}
 	if (connreq) {
 		if (so2->so_options & SO_ACCEPTCONN) {
 			CURVNET_SET(so2->so_vnet);
 			so2 = sonewconn(so2, 0);
 			CURVNET_RESTORE();
 		} else
 			so2 = NULL;
 		if (so2 == NULL) {
 			error = ECONNREFUSED;
 			goto bad2;
 		}
 		unp3 = sotounpcb(so2);
 		unp_pcb_lock_pair(unp2, unp3);
 		if (unp2->unp_addr != NULL) {
 			bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
 			unp3->unp_addr = (struct sockaddr_un *) sa;
 			sa = NULL;
 		}
 
 		unp_copy_peercred(td, unp3, unp, unp2);
 
 		UNP_PCB_UNLOCK(unp2);
 		unp2 = unp3;
 
 		/*
 		 * It is safe to block on the PCB lock here since unp2 is
 		 * nascent and cannot be connected to any other sockets.
 		 */
 		UNP_PCB_LOCK(unp);
 #ifdef MAC
 		mac_socketpeer_set_from_socket(so, so2);
 		mac_socketpeer_set_from_socket(so2, so);
 #endif
 	} else {
 		unp_pcb_lock_pair(unp, unp2);
 	}
 	KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 &&
 	    sotounpcb(so2) == unp2,
 	    ("%s: unp2 %p so2 %p", __func__, unp2, so2));
 	error = unp_connect2(so, so2, PRU_CONNECT);
 	unp_pcb_unlock_pair(unp, unp2);
 bad2:
 	mtx_unlock(vplock);
 bad:
 	if (vp != NULL) {
 		vput(vp);
 	}
 	free(sa, M_SONAME);
 	UNP_PCB_LOCK(unp);
 	KASSERT((unp->unp_flags & UNP_CONNECTING) != 0,
 	    ("%s: unp %p has UNP_CONNECTING clear", __func__, unp));
 	unp->unp_flags &= ~UNP_CONNECTING;
 	UNP_PCB_UNLOCK(unp);
 	return (error);
 }
 
 /*
  * Set socket peer credentials at connection time.
  *
  * The client's PCB credentials are copied from its process structure.  The
  * server's PCB credentials are copied from the socket on which it called
  * listen(2).  uipc_listen cached that process's credentials at the time.
  */
 void
 unp_copy_peercred(struct thread *td, struct unpcb *client_unp,
     struct unpcb *server_unp, struct unpcb *listen_unp)
 {
 	cru2xt(td, &client_unp->unp_peercred);
 	client_unp->unp_flags |= UNP_HAVEPC;
 
 	memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred,
 	    sizeof(server_unp->unp_peercred));
 	server_unp->unp_flags |= UNP_HAVEPC;
 	client_unp->unp_flags |= (listen_unp->unp_flags & UNP_WANTCRED_MASK);
 }
 
 static int
 unp_connect2(struct socket *so, struct socket *so2, int req)
 {
 	struct unpcb *unp;
 	struct unpcb *unp2;
 
 	unp = sotounpcb(so);
 	KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
 	unp2 = sotounpcb(so2);
 	KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
 
 	UNP_PCB_LOCK_ASSERT(unp);
 	UNP_PCB_LOCK_ASSERT(unp2);
 	KASSERT(unp->unp_conn == NULL,
 	    ("%s: socket %p is already connected", __func__, unp));
 
 	if (so2->so_type != so->so_type)
 		return (EPROTOTYPE);
 	unp->unp_conn = unp2;
 	unp_pcb_hold(unp2);
 	unp_pcb_hold(unp);
 	switch (so->so_type) {
 	case SOCK_DGRAM:
 		UNP_REF_LIST_LOCK();
 		LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
 		UNP_REF_LIST_UNLOCK();
 		soisconnected(so);
 		break;
 
 	case SOCK_STREAM:
 	case SOCK_SEQPACKET:
 		KASSERT(unp2->unp_conn == NULL,
 		    ("%s: socket %p is already connected", __func__, unp2));
 		unp2->unp_conn = unp;
 		if (req == PRU_CONNECT &&
 		    ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
 			soisconnecting(so);
 		else
 			soisconnected(so);
 		soisconnected(so2);
 		break;
 
 	default:
 		panic("unp_connect2");
 	}
 	return (0);
 }
 
 static void
 unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
 {
 	struct socket *so, *so2;
 #ifdef INVARIANTS
 	struct unpcb *unptmp;
 #endif
 
 	UNP_PCB_LOCK_ASSERT(unp);
 	UNP_PCB_LOCK_ASSERT(unp2);
 	KASSERT(unp->unp_conn == unp2,
 	    ("%s: unpcb %p is not connected to %p", __func__, unp, unp2));
 
 	unp->unp_conn = NULL;
 	so = unp->unp_socket;
 	so2 = unp2->unp_socket;
 	switch (unp->unp_socket->so_type) {
 	case SOCK_DGRAM:
 		UNP_REF_LIST_LOCK();
 #ifdef INVARIANTS
 		LIST_FOREACH(unptmp, &unp2->unp_refs, unp_reflink) {
 			if (unptmp == unp)
 				break;
 		}
 		KASSERT(unptmp != NULL,
 		    ("%s: %p not found in reflist of %p", __func__, unp, unp2));
 #endif
 		LIST_REMOVE(unp, unp_reflink);
 		UNP_REF_LIST_UNLOCK();
 		if (so) {
 			SOCK_LOCK(so);
 			so->so_state &= ~SS_ISCONNECTED;
 			SOCK_UNLOCK(so);
 		}
 		break;
 
 	case SOCK_STREAM:
 	case SOCK_SEQPACKET:
 		if (so)
 			soisdisconnected(so);
 		MPASS(unp2->unp_conn == unp);
 		unp2->unp_conn = NULL;
 		if (so2)
 			soisdisconnected(so2);
 		break;
 	}
 
 	if (unp == unp2) {
 		unp_pcb_rele_notlast(unp);
 		if (!unp_pcb_rele(unp))
 			UNP_PCB_UNLOCK(unp);
 	} else {
 		if (!unp_pcb_rele(unp))
 			UNP_PCB_UNLOCK(unp);
 		if (!unp_pcb_rele(unp2))
 			UNP_PCB_UNLOCK(unp2);
 	}
 }
 
 /*
  * unp_pcblist() walks the global list of struct unpcb's to generate a
  * pointer list, bumping the refcount on each unpcb.  It then copies them out
  * sequentially, validating the generation number on each to see if it has
  * been detached.  All of this is necessary because copyout() may sleep on
  * disk I/O.
  */
 static int
 unp_pcblist(SYSCTL_HANDLER_ARGS)
 {
 	struct unpcb *unp, **unp_list;
 	unp_gen_t gencnt;
 	struct xunpgen *xug;
 	struct unp_head *head;
 	struct xunpcb *xu;
 	u_int i;
 	int error, n;
 
 	switch ((intptr_t)arg1) {
 	case SOCK_STREAM:
 		head = &unp_shead;
 		break;
 
 	case SOCK_DGRAM:
 		head = &unp_dhead;
 		break;
 
 	case SOCK_SEQPACKET:
 		head = &unp_sphead;
 		break;
 
 	default:
 		panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1);
 	}
 
 	/*
 	 * The process of preparing the PCB list is too time-consuming and
 	 * resource-intensive to repeat twice on every request.
 	 */
 	if (req->oldptr == NULL) {
 		n = unp_count;
 		req->oldidx = 2 * (sizeof *xug)
 			+ (n + n/8) * sizeof(struct xunpcb);
 		return (0);
 	}
 
 	if (req->newptr != NULL)
 		return (EPERM);
 
 	/*
 	 * OK, now we're committed to doing something.
 	 */
 	xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK | M_ZERO);
 	UNP_LINK_RLOCK();
 	gencnt = unp_gencnt;
 	n = unp_count;
 	UNP_LINK_RUNLOCK();
 
 	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) {
 		free(xug, M_TEMP);
 		return (error);
 	}
 
 	unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
 
 	UNP_LINK_RLOCK();
 	for (unp = LIST_FIRST(head), i = 0; unp && i < n;
 	     unp = LIST_NEXT(unp, unp_link)) {
 		UNP_PCB_LOCK(unp);
 		if (unp->unp_gencnt <= gencnt) {
 			if (cr_cansee(req->td->td_ucred,
 			    unp->unp_socket->so_cred)) {
 				UNP_PCB_UNLOCK(unp);
 				continue;
 			}
 			unp_list[i++] = unp;
 			unp_pcb_hold(unp);
 		}
 		UNP_PCB_UNLOCK(unp);
 	}
 	UNP_LINK_RUNLOCK();
 	n = i;			/* In case we lost some during malloc. */
 
 	error = 0;
 	xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
 	for (i = 0; i < n; i++) {
 		unp = unp_list[i];
 		UNP_PCB_LOCK(unp);
 		if (unp_pcb_rele(unp))
 			continue;
 
 		if (unp->unp_gencnt <= gencnt) {
 			xu->xu_len = sizeof *xu;
 			xu->xu_unpp = (uintptr_t)unp;
 			/*
 			 * XXX - need more locking here to protect against
 			 * connect/disconnect races for SMP.
 			 */
 			if (unp->unp_addr != NULL)
 				bcopy(unp->unp_addr, &xu->xu_addr,
 				      unp->unp_addr->sun_len);
 			else
 				bzero(&xu->xu_addr, sizeof(xu->xu_addr));
 			if (unp->unp_conn != NULL &&
 			    unp->unp_conn->unp_addr != NULL)
 				bcopy(unp->unp_conn->unp_addr,
 				      &xu->xu_caddr,
 				      unp->unp_conn->unp_addr->sun_len);
 			else
 				bzero(&xu->xu_caddr, sizeof(xu->xu_caddr));
 			xu->unp_vnode = (uintptr_t)unp->unp_vnode;
 			xu->unp_conn = (uintptr_t)unp->unp_conn;
 			xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs);
 			xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink);
 			xu->unp_gencnt = unp->unp_gencnt;
 			sotoxsocket(unp->unp_socket, &xu->xu_socket);
 			UNP_PCB_UNLOCK(unp);
 			error = SYSCTL_OUT(req, xu, sizeof *xu);
 		} else {
 			UNP_PCB_UNLOCK(unp);
 		}
 	}
 	free(xu, M_TEMP);
 	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.
 		 */
 		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);
 	free(xug, M_TEMP);
 	return (error);
 }
 
 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist,
     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
     (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
     "List of active local datagram sockets");
 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist,
     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
     (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
     "List of active local stream sockets");
 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist,
     CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
     (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb",
     "List of active local seqpacket sockets");
 
 static void
 unp_shutdown(struct unpcb *unp)
 {
 	struct unpcb *unp2;
 	struct socket *so;
 
 	UNP_PCB_LOCK_ASSERT(unp);
 
 	unp2 = unp->unp_conn;
 	if ((unp->unp_socket->so_type == SOCK_STREAM ||
 	    (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) {
 		so = unp2->unp_socket;
 		if (so != NULL)
 			socantrcvmore(so);
 	}
 }
 
 static void
 unp_drop(struct unpcb *unp)
 {
 	struct socket *so = unp->unp_socket;
 	struct unpcb *unp2;
 
 	/*
 	 * Regardless of whether the socket's peer dropped the connection
 	 * with this socket by aborting or disconnecting, POSIX requires
 	 * that ECONNRESET is returned.
 	 */
 
 	UNP_PCB_LOCK(unp);
 	if (so)
 		so->so_error = ECONNRESET;
 	if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) {
 		/* Last reference dropped in unp_disconnect(). */
 		unp_pcb_rele_notlast(unp);
 		unp_disconnect(unp, unp2);
 	} else if (!unp_pcb_rele(unp)) {
 		UNP_PCB_UNLOCK(unp);
 	}
 }
 
 static void
 unp_freerights(struct filedescent **fdep, int fdcount)
 {
 	struct file *fp;
 	int i;
 
 	KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount));
 
 	for (i = 0; i < fdcount; i++) {
 		fp = fdep[i]->fde_file;
 		filecaps_free(&fdep[i]->fde_caps);
 		unp_discard(fp);
 	}
 	free(fdep[0], M_FILECAPS);
 }
 
 static int
 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
 {
 	struct thread *td = curthread;		/* XXX */
 	struct cmsghdr *cm = mtod(control, struct cmsghdr *);
 	int i;
 	int *fdp;
 	struct filedesc *fdesc = td->td_proc->p_fd;
 	struct filedescent **fdep;
 	void *data;
 	socklen_t clen = control->m_len, datalen;
 	int error, newfds;
 	u_int newlen;
 
 	UNP_LINK_UNLOCK_ASSERT();
 
 	error = 0;
 	if (controlp != NULL) /* controlp == NULL => free control messages */
 		*controlp = NULL;
 	while (cm != NULL) {
 		if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
 			error = EINVAL;
 			break;
 		}
 		data = CMSG_DATA(cm);
 		datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
 		if (cm->cmsg_level == SOL_SOCKET
 		    && cm->cmsg_type == SCM_RIGHTS) {
 			newfds = datalen / sizeof(*fdep);
 			if (newfds == 0)
 				goto next;
 			fdep = data;
 
 			/* If we're not outputting the descriptors free them. */
 			if (error || controlp == NULL) {
 				unp_freerights(fdep, newfds);
 				goto next;
 			}
 			FILEDESC_XLOCK(fdesc);
 
 			/*
 			 * 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.
 			 */
 			newlen = newfds * sizeof(int);
 			*controlp = sbcreatecontrol(NULL, newlen,
 			    SCM_RIGHTS, SOL_SOCKET);
 			if (*controlp == NULL) {
 				FILEDESC_XUNLOCK(fdesc);
 				error = E2BIG;
 				unp_freerights(fdep, newfds);
 				goto next;
 			}
 
 			fdp = (int *)
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 			if (fdallocn(td, 0, fdp, newfds) != 0) {
 				FILEDESC_XUNLOCK(fdesc);
 				error = EMSGSIZE;
 				unp_freerights(fdep, newfds);
 				m_freem(*controlp);
 				*controlp = NULL;
 				goto next;
 			}
 			for (i = 0; i < newfds; i++, fdp++) {
 				_finstall(fdesc, fdep[i]->fde_file, *fdp,
-				    (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0,
+				    (flags & MSG_CMSG_CLOEXEC) != 0 ? O_CLOEXEC : 0,
 				    &fdep[i]->fde_caps);
 				unp_externalize_fp(fdep[i]->fde_file);
 			}
 
 			/*
 			 * The new type indicates that the mbuf data refers to
 			 * kernel resources that may need to be released before
 			 * the mbuf is freed.
 			 */
 			m_chtype(*controlp, MT_EXTCONTROL);
 			FILEDESC_XUNLOCK(fdesc);
 			free(fdep[0], M_FILECAPS);
 		} else {
 			/* We can just copy anything else across. */
 			if (error || controlp == NULL)
 				goto next;
 			*controlp = sbcreatecontrol(NULL, datalen,
 			    cm->cmsg_type, cm->cmsg_level);
 			if (*controlp == NULL) {
 				error = ENOBUFS;
 				goto next;
 			}
 			bcopy(data,
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
 			    datalen);
 		}
 		controlp = &(*controlp)->m_next;
 
 next:
 		if (CMSG_SPACE(datalen) < clen) {
 			clen -= CMSG_SPACE(datalen);
 			cm = (struct cmsghdr *)
 			    ((caddr_t)cm + CMSG_SPACE(datalen));
 		} else {
 			clen = 0;
 			cm = NULL;
 		}
 	}
 
 	m_freem(control);
 	return (error);
 }
 
 static void
 unp_zone_change(void *tag)
 {
 
 	uma_zone_set_max(unp_zone, maxsockets);
 }
 
 #ifdef INVARIANTS
 static void
 unp_zdtor(void *mem, int size __unused, void *arg __unused)
 {
 	struct unpcb *unp;
 
 	unp = mem;
 
 	KASSERT(LIST_EMPTY(&unp->unp_refs),
 	    ("%s: unpcb %p has lingering refs", __func__, unp));
 	KASSERT(unp->unp_socket == NULL,
 	    ("%s: unpcb %p has socket backpointer", __func__, unp));
 	KASSERT(unp->unp_vnode == NULL,
 	    ("%s: unpcb %p has vnode references", __func__, unp));
 	KASSERT(unp->unp_conn == NULL,
 	    ("%s: unpcb %p is still connected", __func__, unp));
 	KASSERT(unp->unp_addr == NULL,
 	    ("%s: unpcb %p has leaked addr", __func__, unp));
 }
 #endif
 
 static void
 unp_init(void)
 {
 	uma_dtor dtor;
 
 #ifdef VIMAGE
 	if (!IS_DEFAULT_VNET(curvnet))
 		return;
 #endif
 
 #ifdef INVARIANTS
 	dtor = unp_zdtor;
 #else
 	dtor = NULL;
 #endif
 	unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, dtor,
 	    NULL, NULL, UMA_ALIGN_CACHE, 0);
 	uma_zone_set_max(unp_zone, maxsockets);
 	uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached");
 	EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
 	    NULL, EVENTHANDLER_PRI_ANY);
 	LIST_INIT(&unp_dhead);
 	LIST_INIT(&unp_shead);
 	LIST_INIT(&unp_sphead);
 	SLIST_INIT(&unp_defers);
 	TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL);
 	TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL);
 	UNP_LINK_LOCK_INIT();
 	UNP_DEFERRED_LOCK_INIT();
 }
 
 static void
 unp_internalize_cleanup_rights(struct mbuf *control)
 {
 	struct cmsghdr *cp;
 	struct mbuf *m;
 	void *data;
 	socklen_t datalen;
 
 	for (m = control; m != NULL; m = m->m_next) {
 		cp = mtod(m, struct cmsghdr *);
 		if (cp->cmsg_level != SOL_SOCKET ||
 		    cp->cmsg_type != SCM_RIGHTS)
 			continue;
 		data = CMSG_DATA(cp);
 		datalen = (caddr_t)cp + cp->cmsg_len - (caddr_t)data;
 		unp_freerights(data, datalen / sizeof(struct filedesc *));
 	}
 }
 
 static int
 unp_internalize(struct mbuf **controlp, struct thread *td)
 {
 	struct mbuf *control, **initial_controlp;
 	struct proc *p;
 	struct filedesc *fdesc;
 	struct bintime *bt;
 	struct cmsghdr *cm;
 	struct cmsgcred *cmcred;
 	struct filedescent *fde, **fdep, *fdev;
 	struct file *fp;
 	struct timeval *tv;
 	struct timespec *ts;
 	void *data;
 	socklen_t clen, datalen;
 	int i, j, error, *fdp, oldfds;
 	u_int newlen;
 
 	UNP_LINK_UNLOCK_ASSERT();
 
 	p = td->td_proc;
 	fdesc = p->p_fd;
 	error = 0;
 	control = *controlp;
 	clen = control->m_len;
 	*controlp = NULL;
 	initial_controlp = controlp;
 	for (cm = mtod(control, struct cmsghdr *); cm != NULL;) {
 		if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET
 		    || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) {
 			error = EINVAL;
 			goto out;
 		}
 		data = CMSG_DATA(cm);
 		datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
 
 		switch (cm->cmsg_type) {
 		/*
 		 * Fill in credential information.
 		 */
 		case SCM_CREDS:
 			*controlp = sbcreatecontrol(NULL, sizeof(*cmcred),
 			    SCM_CREDS, SOL_SOCKET);
 			if (*controlp == NULL) {
 				error = ENOBUFS;
 				goto out;
 			}
 			cmcred = (struct cmsgcred *)
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 			cmcred->cmcred_pid = p->p_pid;
 			cmcred->cmcred_uid = td->td_ucred->cr_ruid;
 			cmcred->cmcred_gid = td->td_ucred->cr_rgid;
 			cmcred->cmcred_euid = td->td_ucred->cr_uid;
 			cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups,
 			    CMGROUP_MAX);
 			for (i = 0; i < cmcred->cmcred_ngroups; i++)
 				cmcred->cmcred_groups[i] =
 				    td->td_ucred->cr_groups[i];
 			break;
 
 		case SCM_RIGHTS:
 			oldfds = datalen / sizeof (int);
 			if (oldfds == 0)
 				break;
 			/*
 			 * Check that all the FDs passed in refer to legal
 			 * files.  If not, reject the entire operation.
 			 */
 			fdp = data;
 			FILEDESC_SLOCK(fdesc);
 			for (i = 0; i < oldfds; i++, fdp++) {
 				fp = fget_locked(fdesc, *fdp);
 				if (fp == NULL) {
 					FILEDESC_SUNLOCK(fdesc);
 					error = EBADF;
 					goto out;
 				}
 				if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
 					FILEDESC_SUNLOCK(fdesc);
 					error = EOPNOTSUPP;
 					goto out;
 				}
 			}
 
 			/*
 			 * Now replace the integer FDs with pointers to the
 			 * file structure and capability rights.
 			 */
 			newlen = oldfds * sizeof(fdep[0]);
 			*controlp = sbcreatecontrol(NULL, newlen,
 			    SCM_RIGHTS, SOL_SOCKET);
 			if (*controlp == NULL) {
 				FILEDESC_SUNLOCK(fdesc);
 				error = E2BIG;
 				goto out;
 			}
 			fdp = data;
 			for (i = 0; i < oldfds; i++, fdp++) {
 				if (!fhold(fdesc->fd_ofiles[*fdp].fde_file)) {
 					fdp = data;
 					for (j = 0; j < i; j++, fdp++) {
 						fdrop(fdesc->fd_ofiles[*fdp].
 						    fde_file, td);
 					}
 					FILEDESC_SUNLOCK(fdesc);
 					error = EBADF;
 					goto out;
 				}
 			}
 			fdp = data;
 			fdep = (struct filedescent **)
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 			fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS,
 			    M_WAITOK);
 			for (i = 0; i < oldfds; i++, fdev++, fdp++) {
 				fde = &fdesc->fd_ofiles[*fdp];
 				fdep[i] = fdev;
 				fdep[i]->fde_file = fde->fde_file;
 				filecaps_copy(&fde->fde_caps,
 				    &fdep[i]->fde_caps, true);
 				unp_internalize_fp(fdep[i]->fde_file);
 			}
 			FILEDESC_SUNLOCK(fdesc);
 			break;
 
 		case SCM_TIMESTAMP:
 			*controlp = sbcreatecontrol(NULL, sizeof(*tv),
 			    SCM_TIMESTAMP, SOL_SOCKET);
 			if (*controlp == NULL) {
 				error = ENOBUFS;
 				goto out;
 			}
 			tv = (struct timeval *)
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 			microtime(tv);
 			break;
 
 		case SCM_BINTIME:
 			*controlp = sbcreatecontrol(NULL, sizeof(*bt),
 			    SCM_BINTIME, SOL_SOCKET);
 			if (*controlp == NULL) {
 				error = ENOBUFS;
 				goto out;
 			}
 			bt = (struct bintime *)
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 			bintime(bt);
 			break;
 
 		case SCM_REALTIME:
 			*controlp = sbcreatecontrol(NULL, sizeof(*ts),
 			    SCM_REALTIME, SOL_SOCKET);
 			if (*controlp == NULL) {
 				error = ENOBUFS;
 				goto out;
 			}
 			ts = (struct timespec *)
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 			nanotime(ts);
 			break;
 
 		case SCM_MONOTONIC:
 			*controlp = sbcreatecontrol(NULL, sizeof(*ts),
 			    SCM_MONOTONIC, SOL_SOCKET);
 			if (*controlp == NULL) {
 				error = ENOBUFS;
 				goto out;
 			}
 			ts = (struct timespec *)
 			    CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 			nanouptime(ts);
 			break;
 
 		default:
 			error = EINVAL;
 			goto out;
 		}
 
 		if (*controlp != NULL)
 			controlp = &(*controlp)->m_next;
 		if (CMSG_SPACE(datalen) < clen) {
 			clen -= CMSG_SPACE(datalen);
 			cm = (struct cmsghdr *)
 			    ((caddr_t)cm + CMSG_SPACE(datalen));
 		} else {
 			clen = 0;
 			cm = NULL;
 		}
 	}
 
 out:
 	if (error != 0 && initial_controlp != NULL)
 		unp_internalize_cleanup_rights(*initial_controlp);
 	m_freem(control);
 	return (error);
 }
 
 static struct mbuf *
 unp_addsockcred(struct thread *td, struct mbuf *control, int mode)
 {
 	struct mbuf *m, *n, *n_prev;
 	const struct cmsghdr *cm;
 	int ngroups, i, cmsgtype;
 	size_t ctrlsz;
 
 	ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
 	if (mode & UNP_WANTCRED_ALWAYS) {
 		ctrlsz = SOCKCRED2SIZE(ngroups);
 		cmsgtype = SCM_CREDS2;
 	} else {
 		ctrlsz = SOCKCREDSIZE(ngroups);
 		cmsgtype = SCM_CREDS;
 	}
 
 	m = sbcreatecontrol(NULL, ctrlsz, cmsgtype, SOL_SOCKET);
 	if (m == NULL)
 		return (control);
 
 	if (mode & UNP_WANTCRED_ALWAYS) {
 		struct sockcred2 *sc;
 
 		sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *));
 		sc->sc_version = 0;
 		sc->sc_pid = td->td_proc->p_pid;
 		sc->sc_uid = td->td_ucred->cr_ruid;
 		sc->sc_euid = td->td_ucred->cr_uid;
 		sc->sc_gid = td->td_ucred->cr_rgid;
 		sc->sc_egid = td->td_ucred->cr_gid;
 		sc->sc_ngroups = ngroups;
 		for (i = 0; i < sc->sc_ngroups; i++)
 			sc->sc_groups[i] = td->td_ucred->cr_groups[i];
 	} else {
 		struct sockcred *sc;
 
 		sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *));
 		sc->sc_uid = td->td_ucred->cr_ruid;
 		sc->sc_euid = td->td_ucred->cr_uid;
 		sc->sc_gid = td->td_ucred->cr_rgid;
 		sc->sc_egid = td->td_ucred->cr_gid;
 		sc->sc_ngroups = ngroups;
 		for (i = 0; i < sc->sc_ngroups; i++)
 			sc->sc_groups[i] = td->td_ucred->cr_groups[i];
 	}
 
 	/*
 	 * Unlink SCM_CREDS control messages (struct cmsgcred), since just
 	 * created SCM_CREDS control message (struct sockcred) has another
 	 * format.
 	 */
 	if (control != NULL && cmsgtype == SCM_CREDS)
 		for (n = control, n_prev = NULL; n != NULL;) {
 			cm = mtod(n, struct cmsghdr *);
     			if (cm->cmsg_level == SOL_SOCKET &&
 			    cm->cmsg_type == SCM_CREDS) {
     				if (n_prev == NULL)
 					control = n->m_next;
 				else
 					n_prev->m_next = n->m_next;
 				n = m_free(n);
 			} else {
 				n_prev = n;
 				n = n->m_next;
 			}
 		}
 
 	/* Prepend it to the head. */
 	m->m_next = control;
 	return (m);
 }
 
 static struct unpcb *
 fptounp(struct file *fp)
 {
 	struct socket *so;
 
 	if (fp->f_type != DTYPE_SOCKET)
 		return (NULL);
 	if ((so = fp->f_data) == NULL)
 		return (NULL);
 	if (so->so_proto->pr_domain != &localdomain)
 		return (NULL);
 	return sotounpcb(so);
 }
 
 static void
 unp_discard(struct file *fp)
 {
 	struct unp_defer *dr;
 
 	if (unp_externalize_fp(fp)) {
 		dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK);
 		dr->ud_fp = fp;
 		UNP_DEFERRED_LOCK();
 		SLIST_INSERT_HEAD(&unp_defers, dr, ud_link);
 		UNP_DEFERRED_UNLOCK();
 		atomic_add_int(&unp_defers_count, 1);
 		taskqueue_enqueue(taskqueue_thread, &unp_defer_task);
 	} else
 		closef_nothread(fp);
 }
 
 static void
 unp_process_defers(void *arg __unused, int pending)
 {
 	struct unp_defer *dr;
 	SLIST_HEAD(, unp_defer) drl;
 	int count;
 
 	SLIST_INIT(&drl);
 	for (;;) {
 		UNP_DEFERRED_LOCK();
 		if (SLIST_FIRST(&unp_defers) == NULL) {
 			UNP_DEFERRED_UNLOCK();
 			break;
 		}
 		SLIST_SWAP(&unp_defers, &drl, unp_defer);
 		UNP_DEFERRED_UNLOCK();
 		count = 0;
 		while ((dr = SLIST_FIRST(&drl)) != NULL) {
 			SLIST_REMOVE_HEAD(&drl, ud_link);
 			closef_nothread(dr->ud_fp);
 			free(dr, M_TEMP);
 			count++;
 		}
 		atomic_add_int(&unp_defers_count, -count);
 	}
 }
 
 static void
 unp_internalize_fp(struct file *fp)
 {
 	struct unpcb *unp;
 
 	UNP_LINK_WLOCK();
 	if ((unp = fptounp(fp)) != NULL) {
 		unp->unp_file = fp;
 		unp->unp_msgcount++;
 	}
 	unp_rights++;
 	UNP_LINK_WUNLOCK();
 }
 
 static int
 unp_externalize_fp(struct file *fp)
 {
 	struct unpcb *unp;
 	int ret;
 
 	UNP_LINK_WLOCK();
 	if ((unp = fptounp(fp)) != NULL) {
 		unp->unp_msgcount--;
 		ret = 1;
 	} else
 		ret = 0;
 	unp_rights--;
 	UNP_LINK_WUNLOCK();
 	return (ret);
 }
 
 /*
  * unp_defer indicates whether additional work has been defered for a future
  * pass through unp_gc().  It is thread local and does not require explicit
  * synchronization.
  */
 static int	unp_marked;
 
 static void
 unp_remove_dead_ref(struct filedescent **fdep, int fdcount)
 {
 	struct unpcb *unp;
 	struct file *fp;
 	int i;
 
 	/*
 	 * This function can only be called from the gc task.
 	 */
 	KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0,
 	    ("%s: not on gc callout", __func__));
 	UNP_LINK_LOCK_ASSERT();
 
 	for (i = 0; i < fdcount; i++) {
 		fp = fdep[i]->fde_file;
 		if ((unp = fptounp(fp)) == NULL)
 			continue;
 		if ((unp->unp_gcflag & UNPGC_DEAD) == 0)
 			continue;
 		unp->unp_gcrefs--;
 	}
 }
 
 static void
 unp_restore_undead_ref(struct filedescent **fdep, int fdcount)
 {
 	struct unpcb *unp;
 	struct file *fp;
 	int i;
 
 	/*
 	 * This function can only be called from the gc task.
 	 */
 	KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0,
 	    ("%s: not on gc callout", __func__));
 	UNP_LINK_LOCK_ASSERT();
 
 	for (i = 0; i < fdcount; i++) {
 		fp = fdep[i]->fde_file;
 		if ((unp = fptounp(fp)) == NULL)
 			continue;
 		if ((unp->unp_gcflag & UNPGC_DEAD) == 0)
 			continue;
 		unp->unp_gcrefs++;
 		unp_marked++;
 	}
 }
 
 static void
 unp_gc_scan(struct unpcb *unp, void (*op)(struct filedescent **, int))
 {
 	struct socket *so, *soa;
 
 	so = unp->unp_socket;
 	SOCK_LOCK(so);
 	if (SOLISTENING(so)) {
 		/*
 		 * Mark all sockets in our accept queue.
 		 */
 		TAILQ_FOREACH(soa, &so->sol_comp, so_list) {
 			if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS)
 				continue;
 			SOCKBUF_LOCK(&soa->so_rcv);
 			unp_scan(soa->so_rcv.sb_mb, op);
 			SOCKBUF_UNLOCK(&soa->so_rcv);
 		}
 	} else {
 		/*
 		 * Mark all sockets we reference with RIGHTS.
 		 */
 		if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) {
 			SOCKBUF_LOCK(&so->so_rcv);
 			unp_scan(so->so_rcv.sb_mb, op);
 			SOCKBUF_UNLOCK(&so->so_rcv);
 		}
 	}
 	SOCK_UNLOCK(so);
 }
 
 static int unp_recycled;
 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 
     "Number of unreachable sockets claimed by the garbage collector.");
 
 static int unp_taskcount;
 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 
     "Number of times the garbage collector has run.");
 
 SYSCTL_UINT(_net_local, OID_AUTO, sockcount, CTLFLAG_RD, &unp_count, 0, 
     "Number of active local sockets.");
 
 static void
 unp_gc(__unused void *arg, int pending)
 {
 	struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead,
 				    NULL };
 	struct unp_head **head;
 	struct unp_head unp_deadhead;	/* List of potentially-dead sockets. */
 	struct file *f, **unref;
 	struct unpcb *unp, *unptmp;
 	int i, total, unp_unreachable;
 
 	LIST_INIT(&unp_deadhead);
 	unp_taskcount++;
 	UNP_LINK_RLOCK();
 	/*
 	 * First determine which sockets may be in cycles.
 	 */
 	unp_unreachable = 0;
 
 	for (head = heads; *head != NULL; head++)
 		LIST_FOREACH(unp, *head, unp_link) {
 			KASSERT((unp->unp_gcflag & ~UNPGC_IGNORE_RIGHTS) == 0,
 			    ("%s: unp %p has unexpected gc flags 0x%x",
 			    __func__, unp, (unsigned int)unp->unp_gcflag));
 
 			f = unp->unp_file;
 
 			/*
 			 * Check for an unreachable socket potentially in a
 			 * cycle.  It must be in a queue as indicated by
 			 * msgcount, and this must equal the file reference
 			 * count.  Note that when msgcount is 0 the file is
 			 * NULL.
 			 */
 			if (f != NULL && unp->unp_msgcount != 0 &&
 			    refcount_load(&f->f_count) == unp->unp_msgcount) {
 				LIST_INSERT_HEAD(&unp_deadhead, unp, unp_dead);
 				unp->unp_gcflag |= UNPGC_DEAD;
 				unp->unp_gcrefs = unp->unp_msgcount;
 				unp_unreachable++;
 			}
 		}
 
 	/*
 	 * Scan all sockets previously marked as potentially being in a cycle
 	 * and remove the references each socket holds on any UNPGC_DEAD
 	 * sockets in its queue.  After this step, all remaining references on
 	 * sockets marked UNPGC_DEAD should not be part of any cycle.
 	 */
 	LIST_FOREACH(unp, &unp_deadhead, unp_dead)
 		unp_gc_scan(unp, unp_remove_dead_ref);
 
 	/*
 	 * If a socket still has a non-negative refcount, it cannot be in a
 	 * cycle.  In this case increment refcount of all children iteratively.
 	 * Stop the scan once we do a complete loop without discovering
 	 * a new reachable socket.
 	 */
 	do {
 		unp_marked = 0;
 		LIST_FOREACH_SAFE(unp, &unp_deadhead, unp_dead, unptmp)
 			if (unp->unp_gcrefs > 0) {
 				unp->unp_gcflag &= ~UNPGC_DEAD;
 				LIST_REMOVE(unp, unp_dead);
 				KASSERT(unp_unreachable > 0,
 				    ("%s: unp_unreachable underflow.",
 				    __func__));
 				unp_unreachable--;
 				unp_gc_scan(unp, unp_restore_undead_ref);
 			}
 	} while (unp_marked);
 
 	UNP_LINK_RUNLOCK();
 
 	if (unp_unreachable == 0)
 		return;
 
 	/*
 	 * Allocate space for a local array of dead unpcbs.
 	 * TODO: can this path be simplified by instead using the local
 	 * dead list at unp_deadhead, after taking out references
 	 * on the file object and/or unpcb and dropping the link lock?
 	 */
 	unref = malloc(unp_unreachable * sizeof(struct file *),
 	    M_TEMP, M_WAITOK);
 
 	/*
 	 * Iterate looking for sockets which have been specifically marked
 	 * as unreachable and store them locally.
 	 */
 	UNP_LINK_RLOCK();
 	total = 0;
 	LIST_FOREACH(unp, &unp_deadhead, unp_dead) {
 		KASSERT((unp->unp_gcflag & UNPGC_DEAD) != 0,
 		    ("%s: unp %p not marked UNPGC_DEAD", __func__, unp));
 		unp->unp_gcflag &= ~UNPGC_DEAD;
 		f = unp->unp_file;
 		if (unp->unp_msgcount == 0 || f == NULL ||
 		    refcount_load(&f->f_count) != unp->unp_msgcount ||
 		    !fhold(f))
 			continue;
 		unref[total++] = f;
 		KASSERT(total <= unp_unreachable,
 		    ("%s: incorrect unreachable count.", __func__));
 	}
 	UNP_LINK_RUNLOCK();
 
 	/*
 	 * Now flush all sockets, free'ing rights.  This will free the
 	 * struct files associated with these sockets but leave each socket
 	 * with one remaining ref.
 	 */
 	for (i = 0; i < total; i++) {
 		struct socket *so;
 
 		so = unref[i]->f_data;
 		CURVNET_SET(so->so_vnet);
 		sorflush(so);
 		CURVNET_RESTORE();
 	}
 
 	/*
 	 * And finally release the sockets so they can be reclaimed.
 	 */
 	for (i = 0; i < total; i++)
 		fdrop(unref[i], NULL);
 	unp_recycled += total;
 	free(unref, M_TEMP);
 }
 
 static void
 unp_dispose_mbuf(struct mbuf *m)
 {
 
 	if (m)
 		unp_scan(m, unp_freerights);
 }
 
 /*
  * Synchronize against unp_gc, which can trip over data as we are freeing it.
  */
 static void
 unp_dispose(struct socket *so)
 {
 	struct unpcb *unp;
 
 	unp = sotounpcb(so);
 	UNP_LINK_WLOCK();
 	unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS;
 	UNP_LINK_WUNLOCK();
 	if (!SOLISTENING(so))
 		unp_dispose_mbuf(so->so_rcv.sb_mb);
 }
 
 static void
 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int))
 {
 	struct mbuf *m;
 	struct cmsghdr *cm;
 	void *data;
 	socklen_t clen, datalen;
 
 	while (m0 != NULL) {
 		for (m = m0; m; m = m->m_next) {
 			if (m->m_type != MT_CONTROL)
 				continue;
 
 			cm = mtod(m, struct cmsghdr *);
 			clen = m->m_len;
 
 			while (cm != NULL) {
 				if (sizeof(*cm) > clen || cm->cmsg_len > clen)
 					break;
 
 				data = CMSG_DATA(cm);
 				datalen = (caddr_t)cm + cm->cmsg_len
 				    - (caddr_t)data;
 
 				if (cm->cmsg_level == SOL_SOCKET &&
 				    cm->cmsg_type == SCM_RIGHTS) {
 					(*op)(data, datalen /
 					    sizeof(struct filedescent *));
 				}
 
 				if (CMSG_SPACE(datalen) < clen) {
 					clen -= CMSG_SPACE(datalen);
 					cm = (struct cmsghdr *)
 					    ((caddr_t)cm + CMSG_SPACE(datalen));
 				} else {
 					clen = 0;
 					cm = NULL;
 				}
 			}
 		}
 		m0 = m0->m_nextpkt;
 	}
 }
 
 /*
  * A helper function called by VFS before socket-type vnode reclamation.
  * For an active vnode it clears unp_vnode pointer and decrements unp_vnode
  * use count.
  */
 void
 vfs_unp_reclaim(struct vnode *vp)
 {
 	struct unpcb *unp;
 	int active;
 	struct mtx *vplock;
 
 	ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim");
 	KASSERT(vp->v_type == VSOCK,
 	    ("vfs_unp_reclaim: vp->v_type != VSOCK"));
 
 	active = 0;
 	vplock = mtx_pool_find(mtxpool_sleep, vp);
 	mtx_lock(vplock);
 	VOP_UNP_CONNECT(vp, &unp);
 	if (unp == NULL)
 		goto done;
 	UNP_PCB_LOCK(unp);
 	if (unp->unp_vnode == vp) {
 		VOP_UNP_DETACH(vp);
 		unp->unp_vnode = NULL;
 		active = 1;
 	}
 	UNP_PCB_UNLOCK(unp);
  done:
 	mtx_unlock(vplock);
 	if (active)
 		vunref(vp);
 }
 
 #ifdef DDB
 static void
 db_print_indent(int indent)
 {
 	int i;
 
 	for (i = 0; i < indent; i++)
 		db_printf(" ");
 }
 
 static void
 db_print_unpflags(int unp_flags)
 {
 	int comma;
 
 	comma = 0;
 	if (unp_flags & UNP_HAVEPC) {
 		db_printf("%sUNP_HAVEPC", comma ? ", " : "");
 		comma = 1;
 	}
 	if (unp_flags & UNP_WANTCRED_ALWAYS) {
 		db_printf("%sUNP_WANTCRED_ALWAYS", comma ? ", " : "");
 		comma = 1;
 	}
 	if (unp_flags & UNP_WANTCRED_ONESHOT) {
 		db_printf("%sUNP_WANTCRED_ONESHOT", comma ? ", " : "");
 		comma = 1;
 	}
 	if (unp_flags & UNP_CONNWAIT) {
 		db_printf("%sUNP_CONNWAIT", comma ? ", " : "");
 		comma = 1;
 	}
 	if (unp_flags & UNP_CONNECTING) {
 		db_printf("%sUNP_CONNECTING", comma ? ", " : "");
 		comma = 1;
 	}
 	if (unp_flags & UNP_BINDING) {
 		db_printf("%sUNP_BINDING", comma ? ", " : "");
 		comma = 1;
 	}
 }
 
 static void
 db_print_xucred(int indent, struct xucred *xu)
 {
 	int comma, i;
 
 	db_print_indent(indent);
 	db_printf("cr_version: %u   cr_uid: %u   cr_pid: %d   cr_ngroups: %d\n",
 	    xu->cr_version, xu->cr_uid, xu->cr_pid, xu->cr_ngroups);
 	db_print_indent(indent);
 	db_printf("cr_groups: ");
 	comma = 0;
 	for (i = 0; i < xu->cr_ngroups; i++) {
 		db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
 		comma = 1;
 	}
 	db_printf("\n");
 }
 
 static void
 db_print_unprefs(int indent, struct unp_head *uh)
 {
 	struct unpcb *unp;
 	int counter;
 
 	counter = 0;
 	LIST_FOREACH(unp, uh, unp_reflink) {
 		if (counter % 4 == 0)
 			db_print_indent(indent);
 		db_printf("%p  ", unp);
 		if (counter % 4 == 3)
 			db_printf("\n");
 		counter++;
 	}
 	if (counter != 0 && counter % 4 != 0)
 		db_printf("\n");
 }
 
 DB_SHOW_COMMAND(unpcb, db_show_unpcb)
 {
 	struct unpcb *unp;
 
         if (!have_addr) {
                 db_printf("usage: show unpcb <addr>\n");
                 return;
         }
         unp = (struct unpcb *)addr;
 
 	db_printf("unp_socket: %p   unp_vnode: %p\n", unp->unp_socket,
 	    unp->unp_vnode);
 
 	db_printf("unp_ino: %ju   unp_conn: %p\n", (uintmax_t)unp->unp_ino,
 	    unp->unp_conn);
 
 	db_printf("unp_refs:\n");
 	db_print_unprefs(2, &unp->unp_refs);
 
 	/* XXXRW: Would be nice to print the full address, if any. */
 	db_printf("unp_addr: %p\n", unp->unp_addr);
 
 	db_printf("unp_gencnt: %llu\n",
 	    (unsigned long long)unp->unp_gencnt);
 
 	db_printf("unp_flags: %x (", unp->unp_flags);
 	db_print_unpflags(unp->unp_flags);
 	db_printf(")\n");
 
 	db_printf("unp_peercred:\n");
 	db_print_xucred(2, &unp->unp_peercred);
 
 	db_printf("unp_refcount: %u\n", unp->unp_refcount);
 }
 #endif
diff --git a/tests/sys/kern/unix_passfd_test.c b/tests/sys/kern/unix_passfd_test.c
index 2fac0b3f1a0a..2b5cdde012c1 100644
--- a/tests/sys/kern/unix_passfd_test.c
+++ b/tests/sys/kern/unix_passfd_test.c
@@ -1,710 +1,735 @@
 /*-
  * Copyright (c) 2005 Robert N. M. Watson
  * Copyright (c) 2015 Mark Johnston
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/sysctl.h>
 #include <sys/un.h>
 
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
 #include <atf-c.h>
 
 /*
  * UNIX domain sockets allow file descriptors to be passed via "ancillary
  * data", or control messages.  This regression test is intended to exercise
  * this facility, both performing some basic tests that it operates, and also
  * causing some kernel edge cases to execute, such as garbage collection when
  * there are cyclic file descriptor references.  Right now we test only with
  * stream sockets, but ideally we'd also test with datagram sockets.
  */
 
 static void
 domainsocketpair(int *fdp)
 {
 
 	ATF_REQUIRE_MSG(socketpair(PF_UNIX, SOCK_STREAM, 0, fdp) != -1,
 	    "socketpair(PF_UNIX, SOCK_STREAM) failed: %s", strerror(errno));
 }
 
 static void
 closesocketpair(int *fdp)
 {
 
 	close(fdp[0]);
 	close(fdp[1]);
 }
 
 static void
 devnull(int *fdp)
 {
 	int fd;
 
 	fd = open("/dev/null", O_RDONLY);
 	ATF_REQUIRE_MSG(fd != -1, "open failed: %s", strerror(errno));
 	*fdp = fd;
 }
 
 static void
 tempfile(int *fdp)
 {
 	char path[PATH_MAX];
 	int fd;
 
 	snprintf(path, PATH_MAX, "%s/unix_passfd.XXXXXXXXXXXXXXX",
 	    getenv("TMPDIR") == NULL ? "/tmp" : getenv("TMPDIR"));
 	fd = mkstemp(path);
 	ATF_REQUIRE_MSG(fd != -1, "mkstemp(%s) failed", path);
 	(void)unlink(path);
 	*fdp = fd;
 }
 
 static void
 dofstat(int fd, struct stat *sb)
 {
 
 	ATF_REQUIRE_MSG(fstat(fd, sb) == 0,
 	    "fstat failed: %s", strerror(errno));
 }
 
 static int
 getnfds(void)
 {
 	size_t len;
 	int mib[4], n, rc;
 
 	len = sizeof(n);
 	mib[0] = CTL_KERN;
 	mib[1] = KERN_PROC;
 	mib[2] = KERN_PROC_NFDS;
 	mib[3] = 0;
 
 	rc = sysctl(mib, 4, &n, &len, NULL, 0);
 	ATF_REQUIRE_MSG(rc != -1, "sysctl(KERN_PROC_NFDS) failed");
 	return (n);
 }
 
 static void
 putfds(char *buf, int fd, int nfds)
 {
 	struct cmsghdr *cm;
 	int *fdp, i;
 
 	cm = (struct cmsghdr *)buf;
 	cm->cmsg_len = CMSG_LEN(nfds * sizeof(int));
 	cm->cmsg_level = SOL_SOCKET;
 	cm->cmsg_type = SCM_RIGHTS;
 	for (fdp = (int *)CMSG_DATA(cm), i = 0; i < nfds; i++)
 		*fdp++ = fd;
 }
 
 static void
 samefile(struct stat *sb1, struct stat *sb2)
 {
 
 	ATF_REQUIRE_MSG(sb1->st_dev == sb2->st_dev, "different device");
 	ATF_REQUIRE_MSG(sb1->st_ino == sb2->st_ino, "different inode");
 }
 
 static size_t
 sendfd_payload(int sockfd, int send_fd, void *payload, size_t paylen)
 {
 	struct iovec iovec;
 	char message[CMSG_SPACE(sizeof(int))];
 	struct msghdr msghdr;
 	ssize_t len;
 
 	bzero(&msghdr, sizeof(msghdr));
 	bzero(&message, sizeof(message));
 
 	msghdr.msg_control = message;
 	msghdr.msg_controllen = sizeof(message);
 
 	iovec.iov_base = payload;
 	iovec.iov_len = paylen;
 
 	msghdr.msg_iov = &iovec;
 	msghdr.msg_iovlen = 1;
 
 	putfds(message, send_fd, 1);
 	len = sendmsg(sockfd, &msghdr, 0);
 	ATF_REQUIRE_MSG(len != -1, "sendmsg failed: %s", strerror(errno));
 	return ((size_t)len);
 }
 
 static void
 sendfd(int sockfd, int send_fd)
 {
 	size_t len;
 	char ch;
 
 	ch = 0;
 	len = sendfd_payload(sockfd, send_fd, &ch, sizeof(ch));
 	ATF_REQUIRE_MSG(len == sizeof(ch),
 	    "sendmsg: %zu bytes sent; expected %zu; %s", len, sizeof(ch),
 	    strerror(errno));
 }
 
 static bool
 localcreds(int sockfd)
 {
 	socklen_t sz;
 	int rc, val;
 
 	sz = sizeof(val);
 	rc = getsockopt(sockfd, 0, LOCAL_CREDS, &val, &sz);
 	ATF_REQUIRE_MSG(rc != -1, "getsockopt(LOCAL_CREDS) failed: %s",
 	    strerror(errno));
 	return (val != 0);
 }
 
 static void
 recvfd_payload(int sockfd, int *recv_fd, void *buf, size_t buflen,
-    size_t cmsgsz)
+    size_t cmsgsz, int recvmsg_flags)
 {
 	struct cmsghdr *cmsghdr;
 	struct msghdr msghdr;
 	struct iovec iovec;
 	char *message;
 	ssize_t len;
 	bool foundcreds;
 
 	bzero(&msghdr, sizeof(msghdr));
 	message = malloc(cmsgsz);
 	ATF_REQUIRE(message != NULL);
 
 	msghdr.msg_control = message;
 	msghdr.msg_controllen = cmsgsz;
 
 	iovec.iov_base = buf;
 	iovec.iov_len = buflen;
 
 	msghdr.msg_iov = &iovec;
 	msghdr.msg_iovlen = 1;
 
-	len = recvmsg(sockfd, &msghdr, 0);
+	len = recvmsg(sockfd, &msghdr, recvmsg_flags);
 	ATF_REQUIRE_MSG(len != -1, "recvmsg failed: %s", strerror(errno));
 	ATF_REQUIRE_MSG((size_t)len == buflen,
 	    "recvmsg: %zd bytes received; expected %zd", len, buflen);
 
 	cmsghdr = CMSG_FIRSTHDR(&msghdr);
 	ATF_REQUIRE_MSG(cmsghdr != NULL,
 	    "recvmsg: did not receive control message");
 	foundcreds = false;
 	*recv_fd = -1;
 	for (; cmsghdr != NULL; cmsghdr = CMSG_NXTHDR(&msghdr, cmsghdr)) {
 		if (cmsghdr->cmsg_level == SOL_SOCKET &&
 		    cmsghdr->cmsg_type == SCM_RIGHTS &&
 		    cmsghdr->cmsg_len == CMSG_LEN(sizeof(int))) {
 			memcpy(recv_fd, CMSG_DATA(cmsghdr), sizeof(int));
 			ATF_REQUIRE(*recv_fd != -1);
 		} else if (cmsghdr->cmsg_level == SOL_SOCKET &&
 		    cmsghdr->cmsg_type == SCM_CREDS)
 			foundcreds = true;
 	}
 	ATF_REQUIRE_MSG(*recv_fd != -1,
 	    "recvmsg: did not receive single-fd message");
 	ATF_REQUIRE_MSG(!localcreds(sockfd) || foundcreds,
 	    "recvmsg: expected credentials were not received");
 }
 
 static void
-recvfd(int sockfd, int *recv_fd)
+recvfd(int sockfd, int *recv_fd, int flags)
 {
 	char ch = 0;
 
 	recvfd_payload(sockfd, recv_fd, &ch, sizeof(ch),
-	    CMSG_SPACE(sizeof(int)));
+	    CMSG_SPACE(sizeof(int)), flags);
 }
 
 /*
  * Put a temporary file into a UNIX domain socket, then take it out and make
  * sure it's the same file.  First time around, don't close the reference
  * after sending.
  */
 ATF_TC_WITHOUT_HEAD(simple_send_fd);
 ATF_TC_BODY(simple_send_fd, tc)
 {
 	struct stat getfd_stat, putfd_stat;
 	int fd[2], getfd, putfd;
 
 	domainsocketpair(fd);
 	tempfile(&putfd);
 	dofstat(putfd, &putfd_stat);
 	sendfd(fd[0], putfd);
-	recvfd(fd[1], &getfd);
+	recvfd(fd[1], &getfd, 0);
+	dofstat(getfd, &getfd_stat);
+	samefile(&putfd_stat, &getfd_stat);
+	close(putfd);
+	close(getfd);
+	closesocketpair(fd);
+}
+
+/*
+ * Like simple_send_fd but also sets MSG_CMSG_CLOEXEC and checks that the
+ * received file descriptor has the FD_CLOEXEC flag set.
+ */
+ATF_TC_WITHOUT_HEAD(simple_send_fd_msg_cmsg_cloexec);
+ATF_TC_BODY(simple_send_fd_msg_cmsg_cloexec, tc)
+{
+	struct stat getfd_stat, putfd_stat;
+	int fd[2], getfd, putfd;
+
+	domainsocketpair(fd);
+	tempfile(&putfd);
+	dofstat(putfd, &putfd_stat);
+	sendfd(fd[0], putfd);
+	recvfd(fd[1], &getfd, MSG_CMSG_CLOEXEC);
 	dofstat(getfd, &getfd_stat);
 	samefile(&putfd_stat, &getfd_stat);
+	ATF_REQUIRE_EQ_MSG(fcntl(getfd, F_GETFD) & FD_CLOEXEC, FD_CLOEXEC,
+	    "FD_CLOEXEC not set on the received file descriptor");
 	close(putfd);
 	close(getfd);
 	closesocketpair(fd);
 }
 
 /*
  * Same as simple_send_fd, only close the file reference after sending, so that
  * the only reference is the descriptor in the UNIX domain socket buffer.
  */
 ATF_TC_WITHOUT_HEAD(send_and_close);
 ATF_TC_BODY(send_and_close, tc)
 {
 	struct stat getfd_stat, putfd_stat;
 	int fd[2], getfd, putfd;
 
 	domainsocketpair(fd);
 	tempfile(&putfd);
 	dofstat(putfd, &putfd_stat);
 	sendfd(fd[0], putfd);
 	close(putfd);
-	recvfd(fd[1], &getfd);
+	recvfd(fd[1], &getfd, 0);
 	dofstat(getfd, &getfd_stat);
 	samefile(&putfd_stat, &getfd_stat);
 	close(getfd);
 	closesocketpair(fd);
 }
 
 /*
  * Put a temporary file into a UNIX domain socket, then close both endpoints
  * causing garbage collection to kick off.
  */
 ATF_TC_WITHOUT_HEAD(send_and_cancel);
 ATF_TC_BODY(send_and_cancel, tc)
 {
 	int fd[2], putfd;
 
 	domainsocketpair(fd);
 	tempfile(&putfd);
 	sendfd(fd[0], putfd);
 	close(putfd);
 	closesocketpair(fd);
 }
 
 /*
  * Send two files.  Then receive them.  Make sure they are returned in the
  * right order, and both get there.
  */
 ATF_TC_WITHOUT_HEAD(two_files);
 ATF_TC_BODY(two_files, tc)
 {
 	struct stat getfd_1_stat, getfd_2_stat, putfd_1_stat, putfd_2_stat;
 	int fd[2], getfd_1, getfd_2, putfd_1, putfd_2;
 
 	domainsocketpair(fd);
 	tempfile(&putfd_1);
 	tempfile(&putfd_2);
 	dofstat(putfd_1, &putfd_1_stat);
 	dofstat(putfd_2, &putfd_2_stat);
 	sendfd(fd[0], putfd_1);
 	sendfd(fd[0], putfd_2);
 	close(putfd_1);
 	close(putfd_2);
-	recvfd(fd[1], &getfd_1);
-	recvfd(fd[1], &getfd_2);
+	recvfd(fd[1], &getfd_1, 0);
+	recvfd(fd[1], &getfd_2, 0);
 	dofstat(getfd_1, &getfd_1_stat);
 	dofstat(getfd_2, &getfd_2_stat);
 	samefile(&putfd_1_stat, &getfd_1_stat);
 	samefile(&putfd_2_stat, &getfd_2_stat);
 	close(getfd_1);
 	close(getfd_2);
 	closesocketpair(fd);
 }
 
 /*
  * Big bundling test.  Send an endpoint of the UNIX domain socket over itself,
  * closing the door behind it.
  */
 ATF_TC_WITHOUT_HEAD(bundle);
 ATF_TC_BODY(bundle, tc)
 {
 	int fd[2], getfd;
 
 	domainsocketpair(fd);
 
 	sendfd(fd[0], fd[0]);
 	close(fd[0]);
-	recvfd(fd[1], &getfd);
+	recvfd(fd[1], &getfd, 0);
 	close(getfd);
 	close(fd[1]);
 }
 
 /*
  * Big bundling test part two: Send an endpoint of the UNIX domain socket over
  * itself, close the door behind it, and never remove it from the other end.
  */
 ATF_TC_WITHOUT_HEAD(bundle_cancel);
 ATF_TC_BODY(bundle_cancel, tc)
 {
 	int fd[2];
 
 	domainsocketpair(fd);
 	sendfd(fd[0], fd[0]);
 	sendfd(fd[1], fd[0]);
 	closesocketpair(fd);
 }
 
 /*
  * Test for PR 151758: Send an character device over the UNIX domain socket
  * and then close both sockets to orphan the device.
  */
 ATF_TC_WITHOUT_HEAD(devfs_orphan);
 ATF_TC_BODY(devfs_orphan, tc)
 {
 	int fd[2], putfd;
 
 	domainsocketpair(fd);
 	devnull(&putfd);
 	sendfd(fd[0], putfd);
 	close(putfd);
 	closesocketpair(fd);
 }
 
 #define	LOCAL_SENDSPACE_SYSCTL	"net.local.stream.sendspace"
 
 /*
  * Test for PR 181741. Receiver sets LOCAL_CREDS, and kernel prepends a
  * control message to the data. Sender sends large payload using a non-blocking
  * socket. Payload + SCM_RIGHTS + LOCAL_CREDS hit socket buffer limit, and
  * receiver receives truncated data.
  */
 ATF_TC_WITHOUT_HEAD(rights_creds_payload);
 ATF_TC_BODY(rights_creds_payload, tc)
 {
 	const int on = 1;
 	u_long sendspace;
 	size_t len;
 	void *buf;
 	int fd[2], getfd, putfd, rc;
 
 	len = sizeof(sendspace);
 	rc = sysctlbyname(LOCAL_SENDSPACE_SYSCTL, &sendspace,
 	    &len, NULL, 0);
 	ATF_REQUIRE_MSG(rc != -1,
 	    "sysctl %s failed: %s", LOCAL_SENDSPACE_SYSCTL, strerror(errno));
 
 	buf = calloc(1, sendspace);
 	ATF_REQUIRE(buf != NULL);
 
 	domainsocketpair(fd);
 	tempfile(&putfd);
 
 	rc = fcntl(fd[0], F_SETFL, O_NONBLOCK);
 	ATF_REQUIRE_MSG(rc != -1, "fcntl(O_NONBLOCK) failed: %s",
 	    strerror(errno));
 	rc = setsockopt(fd[1], 0, LOCAL_CREDS, &on, sizeof(on));
 	ATF_REQUIRE_MSG(rc != -1, "setsockopt(LOCAL_CREDS) failed: %s",
 	    strerror(errno));
 
 	len = sendfd_payload(fd[0], putfd, buf, sendspace);
 	ATF_REQUIRE_MSG(len < sendspace, "sendmsg: %zu bytes sent", len);
 	recvfd_payload(fd[1], &getfd, buf, len,
-	    CMSG_SPACE(SOCKCREDSIZE(CMGROUP_MAX)) + CMSG_SPACE(sizeof(int)));
+	    CMSG_SPACE(SOCKCREDSIZE(CMGROUP_MAX)) + CMSG_SPACE(sizeof(int)), 0);
 
 	close(putfd);
 	close(getfd);
 	closesocketpair(fd);
 }
 
 static void
 send_cmsg(int sockfd, void *cmsg, size_t cmsgsz)
 {
 	struct iovec iov;
 	struct msghdr msghdr;
 	ssize_t len;
 	char ch;
 
 	ch = 0;
 	bzero(&msghdr, sizeof(msghdr));
 
 	iov.iov_base = &ch;
 	iov.iov_len = sizeof(ch);
 	msghdr.msg_control = cmsg;
 	msghdr.msg_controllen = cmsgsz;
 	msghdr.msg_iov = &iov;
 	msghdr.msg_iovlen = 1;
 
 	len = sendmsg(sockfd, &msghdr, 0);
 	ATF_REQUIRE_MSG(len != -1,
 	    "sendmsg failed: %s", strerror(errno));
 	ATF_REQUIRE_MSG(len == sizeof(ch),
 	    "sendmsg: %zd bytes sent; expected %zu", len, sizeof(ch));
 }
 
 static void
 recv_cmsg(int sockfd, char *cmsg, size_t cmsgsz, int flags)
 {
 	struct iovec iov;
 	struct msghdr msghdr;
 	ssize_t len;
 	char ch;
 
 	ch = 0;
 	bzero(&msghdr, sizeof(msghdr));
 
 	iov.iov_base = &ch;
 	iov.iov_len = sizeof(ch);
 	msghdr.msg_control = cmsg;
 	msghdr.msg_controllen = cmsgsz;
 	msghdr.msg_iov = &iov;
 	msghdr.msg_iovlen = 1;
 
 	len = recvmsg(sockfd, &msghdr, 0);
 	ATF_REQUIRE_MSG(len != -1,
 	    "recvmsg failed: %s", strerror(errno));
 	ATF_REQUIRE_MSG(len == sizeof(ch),
 	    "recvmsg: %zd bytes received; expected %zu", len, sizeof(ch));
 	ATF_REQUIRE_MSG((msghdr.msg_flags & flags) == flags,
 	    "recvmsg: got flags %#x; expected %#x", msghdr.msg_flags, flags);
 }
 
 /*
  * Test for PR 131876.  Receiver uses a control message buffer that is too
  * small for the incoming SCM_RIGHTS message, so the message is truncated.
  * The kernel must not leak the copied right into the receiver's namespace.
  */
 ATF_TC_WITHOUT_HEAD(truncated_rights);
 ATF_TC_BODY(truncated_rights, tc)
 {
 	char *message;
 	int fd[2], nfds, putfd, rc;
 
 	domainsocketpair(fd);
 	devnull(&putfd);
 	nfds = getnfds();
 
 	/*
 	 * Case 1: Send a single descriptor and truncate the message.
 	 */
 	message = malloc(CMSG_SPACE(sizeof(int)));
 	ATF_REQUIRE(message != NULL);
 	putfds(message, putfd, 1);
 	send_cmsg(fd[0], message, CMSG_LEN(sizeof(int)));
 	recv_cmsg(fd[1], message, CMSG_LEN(0), MSG_CTRUNC);
 	ATF_REQUIRE(getnfds() == nfds);
 	free(message);
 
 	/*
 	 * Case 2a: Send two descriptors in separate messages, and truncate at
 	 *          the boundary between the two messages.  We should still
 	 *          receive the first message.
 	 */
 	message = malloc(CMSG_SPACE(sizeof(int)) * 2);
 	ATF_REQUIRE(message != NULL);
 	putfds(message, putfd, 1);
 	putfds(message + CMSG_SPACE(sizeof(int)), putfd, 1);
 	send_cmsg(fd[0], message, CMSG_SPACE(sizeof(int)) * 2);
 	recv_cmsg(fd[1], message, CMSG_SPACE(sizeof(int)), MSG_CTRUNC);
 	rc = close(*(int *)CMSG_DATA(message));
 	ATF_REQUIRE_MSG(rc == 0, "close failed: %s", strerror(errno));
 	ATF_REQUIRE(getnfds() == nfds);
 	free(message);
 
 	/*
 	 * Case 2b: Send two descriptors in separate messages, and truncate
 	 *          before the end of the first message.
 	 */
 	message = malloc(CMSG_SPACE(sizeof(int)) * 2);
 	ATF_REQUIRE(message != NULL);
 	putfds(message, putfd, 1);
 	putfds(message + CMSG_SPACE(sizeof(int)), putfd, 1);
 	send_cmsg(fd[0], message, CMSG_SPACE(sizeof(int)) * 2);
 	recv_cmsg(fd[1], message, CMSG_SPACE(0), MSG_CTRUNC);
 	ATF_REQUIRE(getnfds() == nfds);
 	free(message);
 
 	/*
 	 * Case 2c: Send two descriptors in separate messages, and truncate
 	 *          after the end of the first message.  We should still
 	 *          receive the first message.
 	 */
 	message = malloc(CMSG_SPACE(sizeof(int)) * 2);
 	ATF_REQUIRE(message != NULL);
 	putfds(message, putfd, 1);
 	putfds(message + CMSG_SPACE(sizeof(int)), putfd, 1);
 	send_cmsg(fd[0], message, CMSG_SPACE(sizeof(int)) * 2);
 	recv_cmsg(fd[1], message, CMSG_SPACE(sizeof(int)) + CMSG_SPACE(0),
 	    MSG_CTRUNC);
 	rc = close(*(int *)CMSG_DATA(message));
 	ATF_REQUIRE_MSG(rc == 0, "close failed: %s", strerror(errno));
 	ATF_REQUIRE(getnfds() == nfds);
 	free(message);
 
 	/*
 	 * Case 3: Send three descriptors in the same message, and leave space
 	 *         only for the first when receiving the message.
 	 */
 	message = malloc(CMSG_SPACE(sizeof(int) * 3));
 	ATF_REQUIRE(message != NULL);
 	putfds(message, putfd, 3);
 	send_cmsg(fd[0], message, CMSG_SPACE(sizeof(int) * 3));
 	recv_cmsg(fd[1], message, CMSG_SPACE(sizeof(int)), MSG_CTRUNC);
 	ATF_REQUIRE(getnfds() == nfds);
 	free(message);
 
 	close(putfd);
 	closesocketpair(fd);
 }
 
 /*
  * Ensure that an attempt to copy a SCM_RIGHTS message to the recipient
  * fails.  In this case the kernel must dispose of the externalized rights
  * rather than leaking them into the recipient's file descriptor table.
  */
 ATF_TC_WITHOUT_HEAD(copyout_rights_error);
 ATF_TC_BODY(copyout_rights_error, tc)
 {
 	struct iovec iovec;
 	struct msghdr msghdr;
 	char buf[16];
 	ssize_t len;
 	int fd[2], error, nfds, putfd;
 
 	memset(buf, 0, sizeof(buf));
 	domainsocketpair(fd);
 	devnull(&putfd);
 	nfds = getnfds();
 
 	sendfd_payload(fd[0], putfd, buf, sizeof(buf));
 
 	bzero(&msghdr, sizeof(msghdr));
 
 	iovec.iov_base = buf;
 	iovec.iov_len = sizeof(buf);
 	msghdr.msg_control = (char *)-1; /* trigger EFAULT */
 	msghdr.msg_controllen = CMSG_SPACE(sizeof(int));
 	msghdr.msg_iov = &iovec;
 	msghdr.msg_iovlen = 1;
 
 	len = recvmsg(fd[1], &msghdr, 0);
 	error = errno;
 	ATF_REQUIRE_MSG(len == -1, "recvmsg succeeded: %zd", len);
 	ATF_REQUIRE_MSG(errno == EFAULT, "expected EFAULT, got %d (%s)",
 	    error, strerror(errno));
 
 	/* Verify that no FDs were leaked. */
 	ATF_REQUIRE(getnfds() == nfds);
 
 	close(putfd);
 	closesocketpair(fd);
 }
 
 /*
  * Verify that we can handle empty rights messages.  Try sending two SCM_RIGHTS
  * messages with a single call, one empty and one containing a single FD.
  */
 ATF_TC_WITHOUT_HEAD(empty_rights_message);
 ATF_TC_BODY(empty_rights_message, tc)
 {
 	struct iovec iov;
 	struct msghdr msghdr;
 	char *cm, message[CMSG_SPACE(0) + CMSG_SPACE(sizeof(int))];
 	ssize_t len;
 	int error, fd[2], putfd;
 
 	domainsocketpair(fd);
 	devnull(&putfd);
 
 	/*
 	 * First, try sending an empty message followed by a non-empty message.
 	 */
 	cm = message;
 	putfds(cm, -1, 0);
 	cm += CMSG_SPACE(0);
 	putfds(cm, putfd, 1);
 
 	memset(&msghdr, 0, sizeof(msghdr));
 	iov.iov_base = NULL;
 	iov.iov_len = 0;
 	msghdr.msg_control = message;
 	msghdr.msg_controllen = sizeof(message);
 	msghdr.msg_iov = &iov;
 	msghdr.msg_iovlen = 1;
 
 	len = sendmsg(fd[0], &msghdr, 0);
 	ATF_REQUIRE_MSG(len == 0, "sendmsg failed: %s", strerror(errno));
 
 	/* Only the non-empty message should be received. */
 	len = recvmsg(fd[1], &msghdr, 0);
 	ATF_REQUIRE_MSG(len == 0, "recvmsg failed: %s", strerror(errno));
 	ATF_REQUIRE(msghdr.msg_controllen = CMSG_SPACE(sizeof(int)));
 	error = close(*(int *)CMSG_DATA(msghdr.msg_control));
 	ATF_REQUIRE_MSG(error == 0, "close failed: %s", strerror(errno));
 
 	/*
 	 * Now try sending with the non-empty message before the empty message.
 	 */
 	cm = message;
 	putfds(cm, putfd, 1);
 	cm += CMSG_SPACE(sizeof(int));
 	putfds(cm, -1, 0);
 
 	memset(&msghdr, 0, sizeof(msghdr));
 	iov.iov_base = NULL;
 	iov.iov_len = 0;
 	msghdr.msg_control = message;
 	msghdr.msg_controllen = CMSG_SPACE(sizeof(int));
 	msghdr.msg_iov = &iov;
 	msghdr.msg_iovlen = 1;
 
 	len = sendmsg(fd[0], &msghdr, 0);
 	ATF_REQUIRE_MSG(len == 0, "sendmsg failed: %s", strerror(errno));
 
 	/* Only the non-empty message should be received. */
 	len = recvmsg(fd[1], &msghdr, 0);
 	ATF_REQUIRE_MSG(len == 0, "recvmsg failed: %s", strerror(errno));
 	ATF_REQUIRE(msghdr.msg_controllen = CMSG_SPACE(sizeof(int)));
 	error = close(*(int *)CMSG_DATA(msghdr.msg_control));
 	ATF_REQUIRE_MSG(error == 0, "close failed: %s", strerror(errno));
 
 	(void)close(putfd);
 }
 
 ATF_TP_ADD_TCS(tp)
 {
 
 	ATF_TP_ADD_TC(tp, simple_send_fd);
+	ATF_TP_ADD_TC(tp, simple_send_fd_msg_cmsg_cloexec);
 	ATF_TP_ADD_TC(tp, send_and_close);
 	ATF_TP_ADD_TC(tp, send_and_cancel);
 	ATF_TP_ADD_TC(tp, two_files);
 	ATF_TP_ADD_TC(tp, bundle);
 	ATF_TP_ADD_TC(tp, bundle_cancel);
 	ATF_TP_ADD_TC(tp, devfs_orphan);
 	ATF_TP_ADD_TC(tp, rights_creds_payload);
 	ATF_TP_ADD_TC(tp, truncated_rights);
 	ATF_TP_ADD_TC(tp, copyout_rights_error);
 	ATF_TP_ADD_TC(tp, empty_rights_message);
 
 	return (atf_no_error());
 }