The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/kern/uipc_usrreq.c

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    1 /*-
    2  * Copyright (c) 1982, 1986, 1989, 1991, 1993
    3  *      The Regents of the University of California.
    4  * Copyright (c) 2004-2009 Robert N. M. Watson
    5  * All rights reserved.
    6  *
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 1. Redistributions of source code must retain the above copyright
   11  *    notice, this list of conditions and the following disclaimer.
   12  * 2. Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in the
   14  *    documentation and/or other materials provided with the distribution.
   15  * 4. Neither the name of the University nor the names of its contributors
   16  *    may be used to endorse or promote products derived from this software
   17  *    without specific prior written permission.
   18  *
   19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   29  * SUCH DAMAGE.
   30  *
   31  *      From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94
   32  */
   33 
   34 /*
   35  * UNIX Domain (Local) Sockets
   36  *
   37  * This is an implementation of UNIX (local) domain sockets.  Each socket has
   38  * an associated struct unpcb (UNIX protocol control block).  Stream sockets
   39  * may be connected to 0 or 1 other socket.  Datagram sockets may be
   40  * connected to 0, 1, or many other sockets.  Sockets may be created and
   41  * connected in pairs (socketpair(2)), or bound/connected to using the file
   42  * system name space.  For most purposes, only the receive socket buffer is
   43  * used, as sending on one socket delivers directly to the receive socket
   44  * buffer of a second socket.
   45  *
   46  * The implementation is substantially complicated by the fact that
   47  * "ancillary data", such as file descriptors or credentials, may be passed
   48  * across UNIX domain sockets.  The potential for passing UNIX domain sockets
   49  * over other UNIX domain sockets requires the implementation of a simple
   50  * garbage collector to find and tear down cycles of disconnected sockets.
   51  *
   52  * TODO:
   53  *      RDM
   54  *      rethink name space problems
   55  *      need a proper out-of-band
   56  */
   57 
   58 #include <sys/cdefs.h>
   59 __FBSDID("$FreeBSD: releng/10.3/sys/kern/uipc_usrreq.c 280258 2015-03-19 13:37:36Z rwatson $");
   60 
   61 #include "opt_ddb.h"
   62 
   63 #include <sys/param.h>
   64 #include <sys/capsicum.h>
   65 #include <sys/domain.h>
   66 #include <sys/fcntl.h>
   67 #include <sys/malloc.h>         /* XXX must be before <sys/file.h> */
   68 #include <sys/eventhandler.h>
   69 #include <sys/file.h>
   70 #include <sys/filedesc.h>
   71 #include <sys/kernel.h>
   72 #include <sys/lock.h>
   73 #include <sys/mbuf.h>
   74 #include <sys/mount.h>
   75 #include <sys/mutex.h>
   76 #include <sys/namei.h>
   77 #include <sys/proc.h>
   78 #include <sys/protosw.h>
   79 #include <sys/queue.h>
   80 #include <sys/resourcevar.h>
   81 #include <sys/rwlock.h>
   82 #include <sys/socket.h>
   83 #include <sys/socketvar.h>
   84 #include <sys/signalvar.h>
   85 #include <sys/stat.h>
   86 #include <sys/sx.h>
   87 #include <sys/sysctl.h>
   88 #include <sys/systm.h>
   89 #include <sys/taskqueue.h>
   90 #include <sys/un.h>
   91 #include <sys/unpcb.h>
   92 #include <sys/vnode.h>
   93 
   94 #include <net/vnet.h>
   95 
   96 #ifdef DDB
   97 #include <ddb/ddb.h>
   98 #endif
   99 
  100 #include <security/mac/mac_framework.h>
  101 
  102 #include <vm/uma.h>
  103 
  104 MALLOC_DECLARE(M_FILECAPS);
  105 
  106 /*
  107  * Locking key:
  108  * (l)  Locked using list lock
  109  * (g)  Locked using linkage lock
  110  */
  111 
  112 static uma_zone_t       unp_zone;
  113 static unp_gen_t        unp_gencnt;     /* (l) */
  114 static u_int            unp_count;      /* (l) Count of local sockets. */
  115 static ino_t            unp_ino;        /* Prototype for fake inode numbers. */
  116 static int              unp_rights;     /* (g) File descriptors in flight. */
  117 static struct unp_head  unp_shead;      /* (l) List of stream sockets. */
  118 static struct unp_head  unp_dhead;      /* (l) List of datagram sockets. */
  119 static struct unp_head  unp_sphead;     /* (l) List of seqpacket sockets. */
  120 
  121 struct unp_defer {
  122         SLIST_ENTRY(unp_defer) ud_link;
  123         struct file *ud_fp;
  124 };
  125 static SLIST_HEAD(, unp_defer) unp_defers;
  126 static int unp_defers_count;
  127 
  128 static const struct sockaddr    sun_noname = { sizeof(sun_noname), AF_LOCAL };
  129 
  130 /*
  131  * Garbage collection of cyclic file descriptor/socket references occurs
  132  * asynchronously in a taskqueue context in order to avoid recursion and
  133  * reentrance in the UNIX domain socket, file descriptor, and socket layer
  134  * code.  See unp_gc() for a full description.
  135  */
  136 static struct timeout_task unp_gc_task;
  137 
  138 /*
  139  * The close of unix domain sockets attached as SCM_RIGHTS is
  140  * postponed to the taskqueue, to avoid arbitrary recursion depth.
  141  * The attached sockets might have another sockets attached.
  142  */
  143 static struct task      unp_defer_task;
  144 
  145 /*
  146  * Both send and receive buffers are allocated PIPSIZ bytes of buffering for
  147  * stream sockets, although the total for sender and receiver is actually
  148  * only PIPSIZ.
  149  *
  150  * Datagram sockets really use the sendspace as the maximum datagram size,
  151  * and don't really want to reserve the sendspace.  Their recvspace should be
  152  * large enough for at least one max-size datagram plus address.
  153  */
  154 #ifndef PIPSIZ
  155 #define PIPSIZ  8192
  156 #endif
  157 static u_long   unpst_sendspace = PIPSIZ;
  158 static u_long   unpst_recvspace = PIPSIZ;
  159 static u_long   unpdg_sendspace = 2*1024;       /* really max datagram size */
  160 static u_long   unpdg_recvspace = 4*1024;
  161 static u_long   unpsp_sendspace = PIPSIZ;       /* really max datagram size */
  162 static u_long   unpsp_recvspace = PIPSIZ;
  163 
  164 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain");
  165 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0,
  166     "SOCK_STREAM");
  167 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM");
  168 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, CTLFLAG_RW, 0,
  169     "SOCK_SEQPACKET");
  170 
  171 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
  172            &unpst_sendspace, 0, "Default stream send space.");
  173 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
  174            &unpst_recvspace, 0, "Default stream receive space.");
  175 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
  176            &unpdg_sendspace, 0, "Default datagram send space.");
  177 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
  178            &unpdg_recvspace, 0, "Default datagram receive space.");
  179 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW,
  180            &unpsp_sendspace, 0, "Default seqpacket send space.");
  181 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW,
  182            &unpsp_recvspace, 0, "Default seqpacket receive space.");
  183 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0,
  184     "File descriptors in flight.");
  185 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD,
  186     &unp_defers_count, 0,
  187     "File descriptors deferred to taskqueue for close.");
  188 
  189 /*
  190  * Locking and synchronization:
  191  *
  192  * Three types of locks exit in the local domain socket implementation: a
  193  * global list mutex, a global linkage rwlock, and per-unpcb mutexes.  Of the
  194  * global locks, the list lock protects the socket count, global generation
  195  * number, and stream/datagram global lists.  The linkage lock protects the
  196  * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be
  197  * held exclusively over the acquisition of multiple unpcb locks to prevent
  198  * deadlock.
  199  *
  200  * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer,
  201  * allocated in pru_attach() and freed in pru_detach().  The validity of that
  202  * pointer is an invariant, so no lock is required to dereference the so_pcb
  203  * pointer if a valid socket reference is held by the caller.  In practice,
  204  * this is always true during operations performed on a socket.  Each unpcb
  205  * has a back-pointer to its socket, unp_socket, which will be stable under
  206  * the same circumstances.
  207  *
  208  * This pointer may only be safely dereferenced as long as a valid reference
  209  * to the unpcb is held.  Typically, this reference will be from the socket,
  210  * or from another unpcb when the referring unpcb's lock is held (in order
  211  * that the reference not be invalidated during use).  For example, to follow
  212  * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn,
  213  * as unp_socket remains valid as long as the reference to unp_conn is valid.
  214  *
  215  * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx.  Individual
  216  * atomic reads without the lock may be performed "lockless", but more
  217  * complex reads and read-modify-writes require the mutex to be held.  No
  218  * lock order is defined between unpcb locks -- multiple unpcb locks may be
  219  * acquired at the same time only when holding the linkage rwlock
  220  * exclusively, which prevents deadlocks.
  221  *
  222  * Blocking with UNIX domain sockets is a tricky issue: unlike most network
  223  * protocols, bind() is a non-atomic operation, and connect() requires
  224  * potential sleeping in the protocol, due to potentially waiting on local or
  225  * distributed file systems.  We try to separate "lookup" operations, which
  226  * may sleep, and the IPC operations themselves, which typically can occur
  227  * with relative atomicity as locks can be held over the entire operation.
  228  *
  229  * Another tricky issue is simultaneous multi-threaded or multi-process
  230  * access to a single UNIX domain socket.  These are handled by the flags
  231  * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or
  232  * binding, both of which involve dropping UNIX domain socket locks in order
  233  * to perform namei() and other file system operations.
  234  */
  235 static struct rwlock    unp_link_rwlock;
  236 static struct mtx       unp_list_lock;
  237 static struct mtx       unp_defers_lock;
  238 
  239 #define UNP_LINK_LOCK_INIT()            rw_init(&unp_link_rwlock,       \
  240                                             "unp_link_rwlock")
  241 
  242 #define UNP_LINK_LOCK_ASSERT()  rw_assert(&unp_link_rwlock,     \
  243                                             RA_LOCKED)
  244 #define UNP_LINK_UNLOCK_ASSERT()        rw_assert(&unp_link_rwlock,     \
  245                                             RA_UNLOCKED)
  246 
  247 #define UNP_LINK_RLOCK()                rw_rlock(&unp_link_rwlock)
  248 #define UNP_LINK_RUNLOCK()              rw_runlock(&unp_link_rwlock)
  249 #define UNP_LINK_WLOCK()                rw_wlock(&unp_link_rwlock)
  250 #define UNP_LINK_WUNLOCK()              rw_wunlock(&unp_link_rwlock)
  251 #define UNP_LINK_WLOCK_ASSERT()         rw_assert(&unp_link_rwlock,     \
  252                                             RA_WLOCKED)
  253 
  254 #define UNP_LIST_LOCK_INIT()            mtx_init(&unp_list_lock,        \
  255                                             "unp_list_lock", NULL, MTX_DEF)
  256 #define UNP_LIST_LOCK()                 mtx_lock(&unp_list_lock)
  257 #define UNP_LIST_UNLOCK()               mtx_unlock(&unp_list_lock)
  258 
  259 #define UNP_DEFERRED_LOCK_INIT()        mtx_init(&unp_defers_lock, \
  260                                             "unp_defer", NULL, MTX_DEF)
  261 #define UNP_DEFERRED_LOCK()             mtx_lock(&unp_defers_lock)
  262 #define UNP_DEFERRED_UNLOCK()           mtx_unlock(&unp_defers_lock)
  263 
  264 #define UNP_PCB_LOCK_INIT(unp)          mtx_init(&(unp)->unp_mtx,       \
  265                                             "unp_mtx", "unp_mtx",       \
  266                                             MTX_DUPOK|MTX_DEF|MTX_RECURSE)
  267 #define UNP_PCB_LOCK_DESTROY(unp)       mtx_destroy(&(unp)->unp_mtx)
  268 #define UNP_PCB_LOCK(unp)               mtx_lock(&(unp)->unp_mtx)
  269 #define UNP_PCB_UNLOCK(unp)             mtx_unlock(&(unp)->unp_mtx)
  270 #define UNP_PCB_LOCK_ASSERT(unp)        mtx_assert(&(unp)->unp_mtx, MA_OWNED)
  271 
  272 static int      uipc_connect2(struct socket *, struct socket *);
  273 static int      uipc_ctloutput(struct socket *, struct sockopt *);
  274 static int      unp_connect(struct socket *, struct sockaddr *,
  275                     struct thread *);
  276 static int      unp_connectat(int, struct socket *, struct sockaddr *,
  277                     struct thread *);
  278 static int      unp_connect2(struct socket *so, struct socket *so2, int);
  279 static void     unp_disconnect(struct unpcb *unp, struct unpcb *unp2);
  280 static void     unp_dispose(struct mbuf *);
  281 static void     unp_shutdown(struct unpcb *);
  282 static void     unp_drop(struct unpcb *, int);
  283 static void     unp_gc(__unused void *, int);
  284 static void     unp_scan(struct mbuf *, void (*)(struct filedescent **, int));
  285 static void     unp_discard(struct file *);
  286 static void     unp_freerights(struct filedescent **, int);
  287 static void     unp_init(void);
  288 static int      unp_internalize(struct mbuf **, struct thread *);
  289 static void     unp_internalize_fp(struct file *);
  290 static int      unp_externalize(struct mbuf *, struct mbuf **, int);
  291 static int      unp_externalize_fp(struct file *);
  292 static struct mbuf      *unp_addsockcred(struct thread *, struct mbuf *);
  293 static void     unp_process_defers(void * __unused, int);
  294 
  295 /*
  296  * Definitions of protocols supported in the LOCAL domain.
  297  */
  298 static struct domain localdomain;
  299 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream;
  300 static struct pr_usrreqs uipc_usrreqs_seqpacket;
  301 static struct protosw localsw[] = {
  302 {
  303         .pr_type =              SOCK_STREAM,
  304         .pr_domain =            &localdomain,
  305         .pr_flags =             PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS,
  306         .pr_ctloutput =         &uipc_ctloutput,
  307         .pr_usrreqs =           &uipc_usrreqs_stream
  308 },
  309 {
  310         .pr_type =              SOCK_DGRAM,
  311         .pr_domain =            &localdomain,
  312         .pr_flags =             PR_ATOMIC|PR_ADDR|PR_RIGHTS,
  313         .pr_ctloutput =         &uipc_ctloutput,
  314         .pr_usrreqs =           &uipc_usrreqs_dgram
  315 },
  316 {
  317         .pr_type =              SOCK_SEQPACKET,
  318         .pr_domain =            &localdomain,
  319 
  320         /*
  321          * XXXRW: For now, PR_ADDR because soreceive will bump into them
  322          * due to our use of sbappendaddr.  A new sbappend variants is needed
  323          * that supports both atomic record writes and control data.
  324          */
  325         .pr_flags =             PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD|
  326                                     PR_RIGHTS,
  327         .pr_ctloutput =         &uipc_ctloutput,
  328         .pr_usrreqs =           &uipc_usrreqs_seqpacket,
  329 },
  330 };
  331 
  332 static struct domain localdomain = {
  333         .dom_family =           AF_LOCAL,
  334         .dom_name =             "local",
  335         .dom_init =             unp_init,
  336         .dom_externalize =      unp_externalize,
  337         .dom_dispose =          unp_dispose,
  338         .dom_protosw =          localsw,
  339         .dom_protoswNPROTOSW =  &localsw[sizeof(localsw)/sizeof(localsw[0])]
  340 };
  341 DOMAIN_SET(local);
  342 
  343 static void
  344 uipc_abort(struct socket *so)
  345 {
  346         struct unpcb *unp, *unp2;
  347 
  348         unp = sotounpcb(so);
  349         KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
  350 
  351         UNP_LINK_WLOCK();
  352         UNP_PCB_LOCK(unp);
  353         unp2 = unp->unp_conn;
  354         if (unp2 != NULL) {
  355                 UNP_PCB_LOCK(unp2);
  356                 unp_drop(unp2, ECONNABORTED);
  357                 UNP_PCB_UNLOCK(unp2);
  358         }
  359         UNP_PCB_UNLOCK(unp);
  360         UNP_LINK_WUNLOCK();
  361 }
  362 
  363 static int
  364 uipc_accept(struct socket *so, struct sockaddr **nam)
  365 {
  366         struct unpcb *unp, *unp2;
  367         const struct sockaddr *sa;
  368 
  369         /*
  370          * Pass back name of connected socket, if it was bound and we are
  371          * still connected (our peer may have closed already!).
  372          */
  373         unp = sotounpcb(so);
  374         KASSERT(unp != NULL, ("uipc_accept: unp == NULL"));
  375 
  376         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
  377         UNP_LINK_RLOCK();
  378         unp2 = unp->unp_conn;
  379         if (unp2 != NULL && unp2->unp_addr != NULL) {
  380                 UNP_PCB_LOCK(unp2);
  381                 sa = (struct sockaddr *) unp2->unp_addr;
  382                 bcopy(sa, *nam, sa->sa_len);
  383                 UNP_PCB_UNLOCK(unp2);
  384         } else {
  385                 sa = &sun_noname;
  386                 bcopy(sa, *nam, sa->sa_len);
  387         }
  388         UNP_LINK_RUNLOCK();
  389         return (0);
  390 }
  391 
  392 static int
  393 uipc_attach(struct socket *so, int proto, struct thread *td)
  394 {
  395         u_long sendspace, recvspace;
  396         struct unpcb *unp;
  397         int error;
  398 
  399         KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
  400         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
  401                 switch (so->so_type) {
  402                 case SOCK_STREAM:
  403                         sendspace = unpst_sendspace;
  404                         recvspace = unpst_recvspace;
  405                         break;
  406 
  407                 case SOCK_DGRAM:
  408                         sendspace = unpdg_sendspace;
  409                         recvspace = unpdg_recvspace;
  410                         break;
  411 
  412                 case SOCK_SEQPACKET:
  413                         sendspace = unpsp_sendspace;
  414                         recvspace = unpsp_recvspace;
  415                         break;
  416 
  417                 default:
  418                         panic("uipc_attach");
  419                 }
  420                 error = soreserve(so, sendspace, recvspace);
  421                 if (error)
  422                         return (error);
  423         }
  424         unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
  425         if (unp == NULL)
  426                 return (ENOBUFS);
  427         LIST_INIT(&unp->unp_refs);
  428         UNP_PCB_LOCK_INIT(unp);
  429         unp->unp_socket = so;
  430         so->so_pcb = unp;
  431         unp->unp_refcount = 1;
  432 
  433         UNP_LIST_LOCK();
  434         unp->unp_gencnt = ++unp_gencnt;
  435         unp_count++;
  436         switch (so->so_type) {
  437         case SOCK_STREAM:
  438                 LIST_INSERT_HEAD(&unp_shead, unp, unp_link);
  439                 break;
  440 
  441         case SOCK_DGRAM:
  442                 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link);
  443                 break;
  444 
  445         case SOCK_SEQPACKET:
  446                 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link);
  447                 break;
  448 
  449         default:
  450                 panic("uipc_attach");
  451         }
  452         UNP_LIST_UNLOCK();
  453 
  454         return (0);
  455 }
  456 
  457 static int
  458 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
  459 {
  460         struct sockaddr_un *soun = (struct sockaddr_un *)nam;
  461         struct vattr vattr;
  462         int error, namelen;
  463         struct nameidata nd;
  464         struct unpcb *unp;
  465         struct vnode *vp;
  466         struct mount *mp;
  467         cap_rights_t rights;
  468         char *buf;
  469 
  470         if (nam->sa_family != AF_UNIX)
  471                 return (EAFNOSUPPORT);
  472 
  473         unp = sotounpcb(so);
  474         KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
  475 
  476         if (soun->sun_len > sizeof(struct sockaddr_un))
  477                 return (EINVAL);
  478         namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
  479         if (namelen <= 0)
  480                 return (EINVAL);
  481 
  482         /*
  483          * We don't allow simultaneous bind() calls on a single UNIX domain
  484          * socket, so flag in-progress operations, and return an error if an
  485          * operation is already in progress.
  486          *
  487          * Historically, we have not allowed a socket to be rebound, so this
  488          * also returns an error.  Not allowing re-binding simplifies the
  489          * implementation and avoids a great many possible failure modes.
  490          */
  491         UNP_PCB_LOCK(unp);
  492         if (unp->unp_vnode != NULL) {
  493                 UNP_PCB_UNLOCK(unp);
  494                 return (EINVAL);
  495         }
  496         if (unp->unp_flags & UNP_BINDING) {
  497                 UNP_PCB_UNLOCK(unp);
  498                 return (EALREADY);
  499         }
  500         unp->unp_flags |= UNP_BINDING;
  501         UNP_PCB_UNLOCK(unp);
  502 
  503         buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
  504         bcopy(soun->sun_path, buf, namelen);
  505         buf[namelen] = 0;
  506 
  507 restart:
  508         NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE,
  509             UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td);
  510 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
  511         error = namei(&nd);
  512         if (error)
  513                 goto error;
  514         vp = nd.ni_vp;
  515         if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
  516                 NDFREE(&nd, NDF_ONLY_PNBUF);
  517                 if (nd.ni_dvp == vp)
  518                         vrele(nd.ni_dvp);
  519                 else
  520                         vput(nd.ni_dvp);
  521                 if (vp != NULL) {
  522                         vrele(vp);
  523                         error = EADDRINUSE;
  524                         goto error;
  525                 }
  526                 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
  527                 if (error)
  528                         goto error;
  529                 goto restart;
  530         }
  531         VATTR_NULL(&vattr);
  532         vattr.va_type = VSOCK;
  533         vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask);
  534 #ifdef MAC
  535         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
  536             &vattr);
  537 #endif
  538         if (error == 0)
  539                 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
  540         NDFREE(&nd, NDF_ONLY_PNBUF);
  541         vput(nd.ni_dvp);
  542         if (error) {
  543                 vn_finished_write(mp);
  544                 goto error;
  545         }
  546         vp = nd.ni_vp;
  547         ASSERT_VOP_ELOCKED(vp, "uipc_bind");
  548         soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
  549 
  550         UNP_LINK_WLOCK();
  551         UNP_PCB_LOCK(unp);
  552         VOP_UNP_BIND(vp, unp->unp_socket);
  553         unp->unp_vnode = vp;
  554         unp->unp_addr = soun;
  555         unp->unp_flags &= ~UNP_BINDING;
  556         UNP_PCB_UNLOCK(unp);
  557         UNP_LINK_WUNLOCK();
  558         VOP_UNLOCK(vp, 0);
  559         vn_finished_write(mp);
  560         free(buf, M_TEMP);
  561         return (0);
  562 
  563 error:
  564         UNP_PCB_LOCK(unp);
  565         unp->unp_flags &= ~UNP_BINDING;
  566         UNP_PCB_UNLOCK(unp);
  567         free(buf, M_TEMP);
  568         return (error);
  569 }
  570 
  571 static int
  572 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
  573 {
  574 
  575         return (uipc_bindat(AT_FDCWD, so, nam, td));
  576 }
  577 
  578 static int
  579 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
  580 {
  581         int error;
  582 
  583         KASSERT(td == curthread, ("uipc_connect: td != curthread"));
  584         UNP_LINK_WLOCK();
  585         error = unp_connect(so, nam, td);
  586         UNP_LINK_WUNLOCK();
  587         return (error);
  588 }
  589 
  590 static int
  591 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam,
  592     struct thread *td)
  593 {
  594         int error;
  595 
  596         KASSERT(td == curthread, ("uipc_connectat: td != curthread"));
  597         UNP_LINK_WLOCK();
  598         error = unp_connectat(fd, so, nam, td);
  599         UNP_LINK_WUNLOCK();
  600         return (error);
  601 }
  602 
  603 static void
  604 uipc_close(struct socket *so)
  605 {
  606         struct unpcb *unp, *unp2;
  607 
  608         unp = sotounpcb(so);
  609         KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
  610 
  611         UNP_LINK_WLOCK();
  612         UNP_PCB_LOCK(unp);
  613         unp2 = unp->unp_conn;
  614         if (unp2 != NULL) {
  615                 UNP_PCB_LOCK(unp2);
  616                 unp_disconnect(unp, unp2);
  617                 UNP_PCB_UNLOCK(unp2);
  618         }
  619         UNP_PCB_UNLOCK(unp);
  620         UNP_LINK_WUNLOCK();
  621 }
  622 
  623 static int
  624 uipc_connect2(struct socket *so1, struct socket *so2)
  625 {
  626         struct unpcb *unp, *unp2;
  627         int error;
  628 
  629         UNP_LINK_WLOCK();
  630         unp = so1->so_pcb;
  631         KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
  632         UNP_PCB_LOCK(unp);
  633         unp2 = so2->so_pcb;
  634         KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
  635         UNP_PCB_LOCK(unp2);
  636         error = unp_connect2(so1, so2, PRU_CONNECT2);
  637         UNP_PCB_UNLOCK(unp2);
  638         UNP_PCB_UNLOCK(unp);
  639         UNP_LINK_WUNLOCK();
  640         return (error);
  641 }
  642 
  643 static void
  644 uipc_detach(struct socket *so)
  645 {
  646         struct unpcb *unp, *unp2;
  647         struct sockaddr_un *saved_unp_addr;
  648         struct vnode *vp;
  649         int freeunp, local_unp_rights;
  650 
  651         unp = sotounpcb(so);
  652         KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
  653 
  654         UNP_LINK_WLOCK();
  655         UNP_LIST_LOCK();
  656         UNP_PCB_LOCK(unp);
  657         LIST_REMOVE(unp, unp_link);
  658         unp->unp_gencnt = ++unp_gencnt;
  659         --unp_count;
  660         UNP_LIST_UNLOCK();
  661 
  662         /*
  663          * XXXRW: Should assert vp->v_socket == so.
  664          */
  665         if ((vp = unp->unp_vnode) != NULL) {
  666                 VOP_UNP_DETACH(vp);
  667                 unp->unp_vnode = NULL;
  668         }
  669         unp2 = unp->unp_conn;
  670         if (unp2 != NULL) {
  671                 UNP_PCB_LOCK(unp2);
  672                 unp_disconnect(unp, unp2);
  673                 UNP_PCB_UNLOCK(unp2);
  674         }
  675 
  676         /*
  677          * We hold the linkage lock exclusively, so it's OK to acquire
  678          * multiple pcb locks at a time.
  679          */
  680         while (!LIST_EMPTY(&unp->unp_refs)) {
  681                 struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
  682 
  683                 UNP_PCB_LOCK(ref);
  684                 unp_drop(ref, ECONNRESET);
  685                 UNP_PCB_UNLOCK(ref);
  686         }
  687         local_unp_rights = unp_rights;
  688         UNP_LINK_WUNLOCK();
  689         unp->unp_socket->so_pcb = NULL;
  690         saved_unp_addr = unp->unp_addr;
  691         unp->unp_addr = NULL;
  692         unp->unp_refcount--;
  693         freeunp = (unp->unp_refcount == 0);
  694         if (saved_unp_addr != NULL)
  695                 free(saved_unp_addr, M_SONAME);
  696         if (freeunp) {
  697                 UNP_PCB_LOCK_DESTROY(unp);
  698                 uma_zfree(unp_zone, unp);
  699         } else
  700                 UNP_PCB_UNLOCK(unp);
  701         if (vp)
  702                 vrele(vp);
  703         if (local_unp_rights)
  704                 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1);
  705 }
  706 
  707 static int
  708 uipc_disconnect(struct socket *so)
  709 {
  710         struct unpcb *unp, *unp2;
  711 
  712         unp = sotounpcb(so);
  713         KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
  714 
  715         UNP_LINK_WLOCK();
  716         UNP_PCB_LOCK(unp);
  717         unp2 = unp->unp_conn;
  718         if (unp2 != NULL) {
  719                 UNP_PCB_LOCK(unp2);
  720                 unp_disconnect(unp, unp2);
  721                 UNP_PCB_UNLOCK(unp2);
  722         }
  723         UNP_PCB_UNLOCK(unp);
  724         UNP_LINK_WUNLOCK();
  725         return (0);
  726 }
  727 
  728 static int
  729 uipc_listen(struct socket *so, int backlog, struct thread *td)
  730 {
  731         struct unpcb *unp;
  732         int error;
  733 
  734         unp = sotounpcb(so);
  735         KASSERT(unp != NULL, ("uipc_listen: unp == NULL"));
  736 
  737         UNP_PCB_LOCK(unp);
  738         if (unp->unp_vnode == NULL) {
  739                 UNP_PCB_UNLOCK(unp);
  740                 return (EINVAL);
  741         }
  742 
  743         SOCK_LOCK(so);
  744         error = solisten_proto_check(so);
  745         if (error == 0) {
  746                 cru2x(td->td_ucred, &unp->unp_peercred);
  747                 unp->unp_flags |= UNP_HAVEPCCACHED;
  748                 solisten_proto(so, backlog);
  749         }
  750         SOCK_UNLOCK(so);
  751         UNP_PCB_UNLOCK(unp);
  752         return (error);
  753 }
  754 
  755 static int
  756 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
  757 {
  758         struct unpcb *unp, *unp2;
  759         const struct sockaddr *sa;
  760 
  761         unp = sotounpcb(so);
  762         KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
  763 
  764         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
  765         UNP_LINK_RLOCK();
  766         /*
  767          * XXX: It seems that this test always fails even when connection is
  768          * established.  So, this else clause is added as workaround to
  769          * return PF_LOCAL sockaddr.
  770          */
  771         unp2 = unp->unp_conn;
  772         if (unp2 != NULL) {
  773                 UNP_PCB_LOCK(unp2);
  774                 if (unp2->unp_addr != NULL)
  775                         sa = (struct sockaddr *) unp2->unp_addr;
  776                 else
  777                         sa = &sun_noname;
  778                 bcopy(sa, *nam, sa->sa_len);
  779                 UNP_PCB_UNLOCK(unp2);
  780         } else {
  781                 sa = &sun_noname;
  782                 bcopy(sa, *nam, sa->sa_len);
  783         }
  784         UNP_LINK_RUNLOCK();
  785         return (0);
  786 }
  787 
  788 static int
  789 uipc_rcvd(struct socket *so, int flags)
  790 {
  791         struct unpcb *unp, *unp2;
  792         struct socket *so2;
  793         u_int mbcnt, sbcc;
  794 
  795         unp = sotounpcb(so);
  796         KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL"));
  797 
  798         if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET)
  799                 panic("uipc_rcvd socktype %d", so->so_type);
  800 
  801         /*
  802          * Adjust backpressure on sender and wakeup any waiting to write.
  803          *
  804          * The unp lock is acquired to maintain the validity of the unp_conn
  805          * pointer; no lock on unp2 is required as unp2->unp_socket will be
  806          * static as long as we don't permit unp2 to disconnect from unp,
  807          * which is prevented by the lock on unp.  We cache values from
  808          * so_rcv to avoid holding the so_rcv lock over the entire
  809          * transaction on the remote so_snd.
  810          */
  811         SOCKBUF_LOCK(&so->so_rcv);
  812         mbcnt = so->so_rcv.sb_mbcnt;
  813         sbcc = so->so_rcv.sb_cc;
  814         SOCKBUF_UNLOCK(&so->so_rcv);
  815         /*
  816          * There is a benign race condition at this point.  If we're planning to
  817          * clear SB_STOP, but uipc_send is called on the connected socket at
  818          * this instant, it might add data to the sockbuf and set SB_STOP.  Then
  819          * we would erroneously clear SB_STOP below, even though the sockbuf is
  820          * full.  The race is benign because the only ill effect is to allow the
  821          * sockbuf to exceed its size limit, and the size limits are not
  822          * strictly guaranteed anyway.
  823          */
  824         UNP_PCB_LOCK(unp);
  825         unp2 = unp->unp_conn;
  826         if (unp2 == NULL) {
  827                 UNP_PCB_UNLOCK(unp);
  828                 return (0);
  829         }
  830         so2 = unp2->unp_socket;
  831         SOCKBUF_LOCK(&so2->so_snd);
  832         if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax)
  833                 so2->so_snd.sb_flags &= ~SB_STOP;
  834         sowwakeup_locked(so2);
  835         UNP_PCB_UNLOCK(unp);
  836         return (0);
  837 }
  838 
  839 static int
  840 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
  841     struct mbuf *control, struct thread *td)
  842 {
  843         struct unpcb *unp, *unp2;
  844         struct socket *so2;
  845         u_int mbcnt, sbcc;
  846         int error = 0;
  847 
  848         unp = sotounpcb(so);
  849         KASSERT(unp != NULL, ("uipc_send: unp == NULL"));
  850 
  851         if (flags & PRUS_OOB) {
  852                 error = EOPNOTSUPP;
  853                 goto release;
  854         }
  855         if (control != NULL && (error = unp_internalize(&control, td)))
  856                 goto release;
  857         if ((nam != NULL) || (flags & PRUS_EOF))
  858                 UNP_LINK_WLOCK();
  859         else
  860                 UNP_LINK_RLOCK();
  861         switch (so->so_type) {
  862         case SOCK_DGRAM:
  863         {
  864                 const struct sockaddr *from;
  865 
  866                 unp2 = unp->unp_conn;
  867                 if (nam != NULL) {
  868                         UNP_LINK_WLOCK_ASSERT();
  869                         if (unp2 != NULL) {
  870                                 error = EISCONN;
  871                                 break;
  872                         }
  873                         error = unp_connect(so, nam, td);
  874                         if (error)
  875                                 break;
  876                         unp2 = unp->unp_conn;
  877                 }
  878 
  879                 /*
  880                  * Because connect() and send() are non-atomic in a sendto()
  881                  * with a target address, it's possible that the socket will
  882                  * have disconnected before the send() can run.  In that case
  883                  * return the slightly counter-intuitive but otherwise
  884                  * correct error that the socket is not connected.
  885                  */
  886                 if (unp2 == NULL) {
  887                         error = ENOTCONN;
  888                         break;
  889                 }
  890                 /* Lockless read. */
  891                 if (unp2->unp_flags & UNP_WANTCRED)
  892                         control = unp_addsockcred(td, control);
  893                 UNP_PCB_LOCK(unp);
  894                 if (unp->unp_addr != NULL)
  895                         from = (struct sockaddr *)unp->unp_addr;
  896                 else
  897                         from = &sun_noname;
  898                 so2 = unp2->unp_socket;
  899                 SOCKBUF_LOCK(&so2->so_rcv);
  900                 if (sbappendaddr_locked(&so2->so_rcv, from, m,
  901                     control)) {
  902                         sorwakeup_locked(so2);
  903                         m = NULL;
  904                         control = NULL;
  905                 } else {
  906                         SOCKBUF_UNLOCK(&so2->so_rcv);
  907                         error = ENOBUFS;
  908                 }
  909                 if (nam != NULL) {
  910                         UNP_LINK_WLOCK_ASSERT();
  911                         UNP_PCB_LOCK(unp2);
  912                         unp_disconnect(unp, unp2);
  913                         UNP_PCB_UNLOCK(unp2);
  914                 }
  915                 UNP_PCB_UNLOCK(unp);
  916                 break;
  917         }
  918 
  919         case SOCK_SEQPACKET:
  920         case SOCK_STREAM:
  921                 if ((so->so_state & SS_ISCONNECTED) == 0) {
  922                         if (nam != NULL) {
  923                                 UNP_LINK_WLOCK_ASSERT();
  924                                 error = unp_connect(so, nam, td);
  925                                 if (error)
  926                                         break;  /* XXX */
  927                         } else {
  928                                 error = ENOTCONN;
  929                                 break;
  930                         }
  931                 }
  932 
  933                 /* Lockless read. */
  934                 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
  935                         error = EPIPE;
  936                         break;
  937                 }
  938 
  939                 /*
  940                  * Because connect() and send() are non-atomic in a sendto()
  941                  * with a target address, it's possible that the socket will
  942                  * have disconnected before the send() can run.  In that case
  943                  * return the slightly counter-intuitive but otherwise
  944                  * correct error that the socket is not connected.
  945                  *
  946                  * Locking here must be done carefully: the linkage lock
  947                  * prevents interconnections between unpcbs from changing, so
  948                  * we can traverse from unp to unp2 without acquiring unp's
  949                  * lock.  Socket buffer locks follow unpcb locks, so we can
  950                  * acquire both remote and lock socket buffer locks.
  951                  */
  952                 unp2 = unp->unp_conn;
  953                 if (unp2 == NULL) {
  954                         error = ENOTCONN;
  955                         break;
  956                 }
  957                 so2 = unp2->unp_socket;
  958                 UNP_PCB_LOCK(unp2);
  959                 SOCKBUF_LOCK(&so2->so_rcv);
  960                 if (unp2->unp_flags & UNP_WANTCRED) {
  961                         /*
  962                          * Credentials are passed only once on SOCK_STREAM
  963                          * and SOCK_SEQPACKET.
  964                          */
  965                         unp2->unp_flags &= ~UNP_WANTCRED;
  966                         control = unp_addsockcred(td, control);
  967                 }
  968                 /*
  969                  * Send to paired receive port, and then reduce send buffer
  970                  * hiwater marks to maintain backpressure.  Wake up readers.
  971                  */
  972                 switch (so->so_type) {
  973                 case SOCK_STREAM:
  974                         if (control != NULL) {
  975                                 if (sbappendcontrol_locked(&so2->so_rcv, m,
  976                                     control))
  977                                         control = NULL;
  978                         } else
  979                                 sbappend_locked(&so2->so_rcv, m);
  980                         break;
  981 
  982                 case SOCK_SEQPACKET: {
  983                         const struct sockaddr *from;
  984 
  985                         from = &sun_noname;
  986                         /*
  987                          * Don't check for space available in so2->so_rcv.
  988                          * Unix domain sockets only check for space in the
  989                          * sending sockbuf, and that check is performed one
  990                          * level up the stack.
  991                          */
  992                         if (sbappendaddr_nospacecheck_locked(&so2->so_rcv,
  993                                 from, m, control))
  994                                 control = NULL;
  995                         break;
  996                         }
  997                 }
  998 
  999                 mbcnt = so2->so_rcv.sb_mbcnt;
 1000                 sbcc = so2->so_rcv.sb_cc;
 1001                 sorwakeup_locked(so2);
 1002 
 1003                 /*
 1004                  * The PCB lock on unp2 protects the SB_STOP flag.  Without it,
 1005                  * it would be possible for uipc_rcvd to be called at this
 1006                  * point, drain the receiving sockbuf, clear SB_STOP, and then
 1007                  * we would set SB_STOP below.  That could lead to an empty
 1008                  * sockbuf having SB_STOP set
 1009                  */
 1010                 SOCKBUF_LOCK(&so->so_snd);
 1011                 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax)
 1012                         so->so_snd.sb_flags |= SB_STOP;
 1013                 SOCKBUF_UNLOCK(&so->so_snd);
 1014                 UNP_PCB_UNLOCK(unp2);
 1015                 m = NULL;
 1016                 break;
 1017 
 1018         default:
 1019                 panic("uipc_send unknown socktype");
 1020         }
 1021 
 1022         /*
 1023          * PRUS_EOF is equivalent to pru_send followed by pru_shutdown.
 1024          */
 1025         if (flags & PRUS_EOF) {
 1026                 UNP_PCB_LOCK(unp);
 1027                 socantsendmore(so);
 1028                 unp_shutdown(unp);
 1029                 UNP_PCB_UNLOCK(unp);
 1030         }
 1031 
 1032         if ((nam != NULL) || (flags & PRUS_EOF))
 1033                 UNP_LINK_WUNLOCK();
 1034         else
 1035                 UNP_LINK_RUNLOCK();
 1036 
 1037         if (control != NULL && error != 0)
 1038                 unp_dispose(control);
 1039 
 1040 release:
 1041         if (control != NULL)
 1042                 m_freem(control);
 1043         if (m != NULL)
 1044                 m_freem(m);
 1045         return (error);
 1046 }
 1047 
 1048 static int
 1049 uipc_sense(struct socket *so, struct stat *sb)
 1050 {
 1051         struct unpcb *unp;
 1052 
 1053         unp = sotounpcb(so);
 1054         KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
 1055 
 1056         sb->st_blksize = so->so_snd.sb_hiwat;
 1057         UNP_PCB_LOCK(unp);
 1058         sb->st_dev = NODEV;
 1059         if (unp->unp_ino == 0)
 1060                 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
 1061         sb->st_ino = unp->unp_ino;
 1062         UNP_PCB_UNLOCK(unp);
 1063         return (0);
 1064 }
 1065 
 1066 static int
 1067 uipc_shutdown(struct socket *so)
 1068 {
 1069         struct unpcb *unp;
 1070 
 1071         unp = sotounpcb(so);
 1072         KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL"));
 1073 
 1074         UNP_LINK_WLOCK();
 1075         UNP_PCB_LOCK(unp);
 1076         socantsendmore(so);
 1077         unp_shutdown(unp);
 1078         UNP_PCB_UNLOCK(unp);
 1079         UNP_LINK_WUNLOCK();
 1080         return (0);
 1081 }
 1082 
 1083 static int
 1084 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
 1085 {
 1086         struct unpcb *unp;
 1087         const struct sockaddr *sa;
 1088 
 1089         unp = sotounpcb(so);
 1090         KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
 1091 
 1092         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 1093         UNP_PCB_LOCK(unp);
 1094         if (unp->unp_addr != NULL)
 1095                 sa = (struct sockaddr *) unp->unp_addr;
 1096         else
 1097                 sa = &sun_noname;
 1098         bcopy(sa, *nam, sa->sa_len);
 1099         UNP_PCB_UNLOCK(unp);
 1100         return (0);
 1101 }
 1102 
 1103 static struct pr_usrreqs uipc_usrreqs_dgram = {
 1104         .pru_abort =            uipc_abort,
 1105         .pru_accept =           uipc_accept,
 1106         .pru_attach =           uipc_attach,
 1107         .pru_bind =             uipc_bind,
 1108         .pru_bindat =           uipc_bindat,
 1109         .pru_connect =          uipc_connect,
 1110         .pru_connectat =        uipc_connectat,
 1111         .pru_connect2 =         uipc_connect2,
 1112         .pru_detach =           uipc_detach,
 1113         .pru_disconnect =       uipc_disconnect,
 1114         .pru_listen =           uipc_listen,
 1115         .pru_peeraddr =         uipc_peeraddr,
 1116         .pru_rcvd =             uipc_rcvd,
 1117         .pru_send =             uipc_send,
 1118         .pru_sense =            uipc_sense,
 1119         .pru_shutdown =         uipc_shutdown,
 1120         .pru_sockaddr =         uipc_sockaddr,
 1121         .pru_soreceive =        soreceive_dgram,
 1122         .pru_close =            uipc_close,
 1123 };
 1124 
 1125 static struct pr_usrreqs uipc_usrreqs_seqpacket = {
 1126         .pru_abort =            uipc_abort,
 1127         .pru_accept =           uipc_accept,
 1128         .pru_attach =           uipc_attach,
 1129         .pru_bind =             uipc_bind,
 1130         .pru_bindat =           uipc_bindat,
 1131         .pru_connect =          uipc_connect,
 1132         .pru_connectat =        uipc_connectat,
 1133         .pru_connect2 =         uipc_connect2,
 1134         .pru_detach =           uipc_detach,
 1135         .pru_disconnect =       uipc_disconnect,
 1136         .pru_listen =           uipc_listen,
 1137         .pru_peeraddr =         uipc_peeraddr,
 1138         .pru_rcvd =             uipc_rcvd,
 1139         .pru_send =             uipc_send,
 1140         .pru_sense =            uipc_sense,
 1141         .pru_shutdown =         uipc_shutdown,
 1142         .pru_sockaddr =         uipc_sockaddr,
 1143         .pru_soreceive =        soreceive_generic,      /* XXX: or...? */
 1144         .pru_close =            uipc_close,
 1145 };
 1146 
 1147 static struct pr_usrreqs uipc_usrreqs_stream = {
 1148         .pru_abort =            uipc_abort,
 1149         .pru_accept =           uipc_accept,
 1150         .pru_attach =           uipc_attach,
 1151         .pru_bind =             uipc_bind,
 1152         .pru_bindat =           uipc_bindat,
 1153         .pru_connect =          uipc_connect,
 1154         .pru_connectat =        uipc_connectat,
 1155         .pru_connect2 =         uipc_connect2,
 1156         .pru_detach =           uipc_detach,
 1157         .pru_disconnect =       uipc_disconnect,
 1158         .pru_listen =           uipc_listen,
 1159         .pru_peeraddr =         uipc_peeraddr,
 1160         .pru_rcvd =             uipc_rcvd,
 1161         .pru_send =             uipc_send,
 1162         .pru_sense =            uipc_sense,
 1163         .pru_shutdown =         uipc_shutdown,
 1164         .pru_sockaddr =         uipc_sockaddr,
 1165         .pru_soreceive =        soreceive_generic,
 1166         .pru_close =            uipc_close,
 1167 };
 1168 
 1169 static int
 1170 uipc_ctloutput(struct socket *so, struct sockopt *sopt)
 1171 {
 1172         struct unpcb *unp;
 1173         struct xucred xu;
 1174         int error, optval;
 1175 
 1176         if (sopt->sopt_level != 0)
 1177                 return (EINVAL);
 1178 
 1179         unp = sotounpcb(so);
 1180         KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
 1181         error = 0;
 1182         switch (sopt->sopt_dir) {
 1183         case SOPT_GET:
 1184                 switch (sopt->sopt_name) {
 1185                 case LOCAL_PEERCRED:
 1186                         UNP_PCB_LOCK(unp);
 1187                         if (unp->unp_flags & UNP_HAVEPC)
 1188                                 xu = unp->unp_peercred;
 1189                         else {
 1190                                 if (so->so_type == SOCK_STREAM)
 1191                                         error = ENOTCONN;
 1192                                 else
 1193                                         error = EINVAL;
 1194                         }
 1195                         UNP_PCB_UNLOCK(unp);
 1196                         if (error == 0)
 1197                                 error = sooptcopyout(sopt, &xu, sizeof(xu));
 1198                         break;
 1199 
 1200                 case LOCAL_CREDS:
 1201                         /* Unlocked read. */
 1202                         optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0;
 1203                         error = sooptcopyout(sopt, &optval, sizeof(optval));
 1204                         break;
 1205 
 1206                 case LOCAL_CONNWAIT:
 1207                         /* Unlocked read. */
 1208                         optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0;
 1209                         error = sooptcopyout(sopt, &optval, sizeof(optval));
 1210                         break;
 1211 
 1212                 default:
 1213                         error = EOPNOTSUPP;
 1214                         break;
 1215                 }
 1216                 break;
 1217 
 1218         case SOPT_SET:
 1219                 switch (sopt->sopt_name) {
 1220                 case LOCAL_CREDS:
 1221                 case LOCAL_CONNWAIT:
 1222                         error = sooptcopyin(sopt, &optval, sizeof(optval),
 1223                                             sizeof(optval));
 1224                         if (error)
 1225                                 break;
 1226 
 1227 #define OPTSET(bit) do {                                                \
 1228         UNP_PCB_LOCK(unp);                                              \
 1229         if (optval)                                                     \
 1230                 unp->unp_flags |= bit;                                  \
 1231         else                                                            \
 1232                 unp->unp_flags &= ~bit;                                 \
 1233         UNP_PCB_UNLOCK(unp);                                            \
 1234 } while (0)
 1235 
 1236                         switch (sopt->sopt_name) {
 1237                         case LOCAL_CREDS:
 1238                                 OPTSET(UNP_WANTCRED);
 1239                                 break;
 1240 
 1241                         case LOCAL_CONNWAIT:
 1242                                 OPTSET(UNP_CONNWAIT);
 1243                                 break;
 1244 
 1245                         default:
 1246                                 break;
 1247                         }
 1248                         break;
 1249 #undef  OPTSET
 1250                 default:
 1251                         error = ENOPROTOOPT;
 1252                         break;
 1253                 }
 1254                 break;
 1255 
 1256         default:
 1257                 error = EOPNOTSUPP;
 1258                 break;
 1259         }
 1260         return (error);
 1261 }
 1262 
 1263 static int
 1264 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 1265 {
 1266 
 1267         return (unp_connectat(AT_FDCWD, so, nam, td));
 1268 }
 1269 
 1270 static int
 1271 unp_connectat(int fd, struct socket *so, struct sockaddr *nam,
 1272     struct thread *td)
 1273 {
 1274         struct sockaddr_un *soun = (struct sockaddr_un *)nam;
 1275         struct vnode *vp;
 1276         struct socket *so2, *so3;
 1277         struct unpcb *unp, *unp2, *unp3;
 1278         struct nameidata nd;
 1279         char buf[SOCK_MAXADDRLEN];
 1280         struct sockaddr *sa;
 1281         cap_rights_t rights;
 1282         int error, len;
 1283 
 1284         if (nam->sa_family != AF_UNIX)
 1285                 return (EAFNOSUPPORT);
 1286 
 1287         UNP_LINK_WLOCK_ASSERT();
 1288 
 1289         unp = sotounpcb(so);
 1290         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
 1291 
 1292         if (nam->sa_len > sizeof(struct sockaddr_un))
 1293                 return (EINVAL);
 1294         len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
 1295         if (len <= 0)
 1296                 return (EINVAL);
 1297         bcopy(soun->sun_path, buf, len);
 1298         buf[len] = 0;
 1299 
 1300         UNP_PCB_LOCK(unp);
 1301         if (unp->unp_flags & UNP_CONNECTING) {
 1302                 UNP_PCB_UNLOCK(unp);
 1303                 return (EALREADY);
 1304         }
 1305         UNP_LINK_WUNLOCK();
 1306         unp->unp_flags |= UNP_CONNECTING;
 1307         UNP_PCB_UNLOCK(unp);
 1308 
 1309         sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 1310         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
 1311             UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td);
 1312         error = namei(&nd);
 1313         if (error)
 1314                 vp = NULL;
 1315         else
 1316                 vp = nd.ni_vp;
 1317         ASSERT_VOP_LOCKED(vp, "unp_connect");
 1318         NDFREE(&nd, NDF_ONLY_PNBUF);
 1319         if (error)
 1320                 goto bad;
 1321 
 1322         if (vp->v_type != VSOCK) {
 1323                 error = ENOTSOCK;
 1324                 goto bad;
 1325         }
 1326 #ifdef MAC
 1327         error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
 1328         if (error)
 1329                 goto bad;
 1330 #endif
 1331         error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
 1332         if (error)
 1333                 goto bad;
 1334 
 1335         unp = sotounpcb(so);
 1336         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
 1337 
 1338         /*
 1339          * Lock linkage lock for two reasons: make sure v_socket is stable,
 1340          * and to protect simultaneous locking of multiple pcbs.
 1341          */
 1342         UNP_LINK_WLOCK();
 1343         VOP_UNP_CONNECT(vp, &so2);
 1344         if (so2 == NULL) {
 1345                 error = ECONNREFUSED;
 1346                 goto bad2;
 1347         }
 1348         if (so->so_type != so2->so_type) {
 1349                 error = EPROTOTYPE;
 1350                 goto bad2;
 1351         }
 1352         if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
 1353                 if (so2->so_options & SO_ACCEPTCONN) {
 1354                         CURVNET_SET(so2->so_vnet);
 1355                         so3 = sonewconn(so2, 0);
 1356                         CURVNET_RESTORE();
 1357                 } else
 1358                         so3 = NULL;
 1359                 if (so3 == NULL) {
 1360                         error = ECONNREFUSED;
 1361                         goto bad2;
 1362                 }
 1363                 unp = sotounpcb(so);
 1364                 unp2 = sotounpcb(so2);
 1365                 unp3 = sotounpcb(so3);
 1366                 UNP_PCB_LOCK(unp);
 1367                 UNP_PCB_LOCK(unp2);
 1368                 UNP_PCB_LOCK(unp3);
 1369                 if (unp2->unp_addr != NULL) {
 1370                         bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
 1371                         unp3->unp_addr = (struct sockaddr_un *) sa;
 1372                         sa = NULL;
 1373                 }
 1374 
 1375                 /*
 1376                  * The connector's (client's) credentials are copied from its
 1377                  * process structure at the time of connect() (which is now).
 1378                  */
 1379                 cru2x(td->td_ucred, &unp3->unp_peercred);
 1380                 unp3->unp_flags |= UNP_HAVEPC;
 1381 
 1382                 /*
 1383                  * The receiver's (server's) credentials are copied from the
 1384                  * unp_peercred member of socket on which the former called
 1385                  * listen(); uipc_listen() cached that process's credentials
 1386                  * at that time so we can use them now.
 1387                  */
 1388                 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
 1389                     ("unp_connect: listener without cached peercred"));
 1390                 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
 1391                     sizeof(unp->unp_peercred));
 1392                 unp->unp_flags |= UNP_HAVEPC;
 1393                 if (unp2->unp_flags & UNP_WANTCRED)
 1394                         unp3->unp_flags |= UNP_WANTCRED;
 1395                 UNP_PCB_UNLOCK(unp3);
 1396                 UNP_PCB_UNLOCK(unp2);
 1397                 UNP_PCB_UNLOCK(unp);
 1398 #ifdef MAC
 1399                 mac_socketpeer_set_from_socket(so, so3);
 1400                 mac_socketpeer_set_from_socket(so3, so);
 1401 #endif
 1402 
 1403                 so2 = so3;
 1404         }
 1405         unp = sotounpcb(so);
 1406         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
 1407         unp2 = sotounpcb(so2);
 1408         KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL"));
 1409         UNP_PCB_LOCK(unp);
 1410         UNP_PCB_LOCK(unp2);
 1411         error = unp_connect2(so, so2, PRU_CONNECT);
 1412         UNP_PCB_UNLOCK(unp2);
 1413         UNP_PCB_UNLOCK(unp);
 1414 bad2:
 1415         UNP_LINK_WUNLOCK();
 1416 bad:
 1417         if (vp != NULL)
 1418                 vput(vp);
 1419         free(sa, M_SONAME);
 1420         UNP_LINK_WLOCK();
 1421         UNP_PCB_LOCK(unp);
 1422         unp->unp_flags &= ~UNP_CONNECTING;
 1423         UNP_PCB_UNLOCK(unp);
 1424         return (error);
 1425 }
 1426 
 1427 static int
 1428 unp_connect2(struct socket *so, struct socket *so2, int req)
 1429 {
 1430         struct unpcb *unp;
 1431         struct unpcb *unp2;
 1432 
 1433         unp = sotounpcb(so);
 1434         KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
 1435         unp2 = sotounpcb(so2);
 1436         KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
 1437 
 1438         UNP_LINK_WLOCK_ASSERT();
 1439         UNP_PCB_LOCK_ASSERT(unp);
 1440         UNP_PCB_LOCK_ASSERT(unp2);
 1441 
 1442         if (so2->so_type != so->so_type)
 1443                 return (EPROTOTYPE);
 1444         unp->unp_conn = unp2;
 1445 
 1446         switch (so->so_type) {
 1447         case SOCK_DGRAM:
 1448                 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
 1449                 soisconnected(so);
 1450                 break;
 1451 
 1452         case SOCK_STREAM:
 1453         case SOCK_SEQPACKET:
 1454                 unp2->unp_conn = unp;
 1455                 if (req == PRU_CONNECT &&
 1456                     ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
 1457                         soisconnecting(so);
 1458                 else
 1459                         soisconnected(so);
 1460                 soisconnected(so2);
 1461                 break;
 1462 
 1463         default:
 1464                 panic("unp_connect2");
 1465         }
 1466         return (0);
 1467 }
 1468 
 1469 static void
 1470 unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
 1471 {
 1472         struct socket *so;
 1473 
 1474         KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL"));
 1475 
 1476         UNP_LINK_WLOCK_ASSERT();
 1477         UNP_PCB_LOCK_ASSERT(unp);
 1478         UNP_PCB_LOCK_ASSERT(unp2);
 1479 
 1480         unp->unp_conn = NULL;
 1481         switch (unp->unp_socket->so_type) {
 1482         case SOCK_DGRAM:
 1483                 LIST_REMOVE(unp, unp_reflink);
 1484                 so = unp->unp_socket;
 1485                 SOCK_LOCK(so);
 1486                 so->so_state &= ~SS_ISCONNECTED;
 1487                 SOCK_UNLOCK(so);
 1488                 break;
 1489 
 1490         case SOCK_STREAM:
 1491         case SOCK_SEQPACKET:
 1492                 soisdisconnected(unp->unp_socket);
 1493                 unp2->unp_conn = NULL;
 1494                 soisdisconnected(unp2->unp_socket);
 1495                 break;
 1496         }
 1497 }
 1498 
 1499 /*
 1500  * unp_pcblist() walks the global list of struct unpcb's to generate a
 1501  * pointer list, bumping the refcount on each unpcb.  It then copies them out
 1502  * sequentially, validating the generation number on each to see if it has
 1503  * been detached.  All of this is necessary because copyout() may sleep on
 1504  * disk I/O.
 1505  */
 1506 static int
 1507 unp_pcblist(SYSCTL_HANDLER_ARGS)
 1508 {
 1509         int error, i, n;
 1510         int freeunp;
 1511         struct unpcb *unp, **unp_list;
 1512         unp_gen_t gencnt;
 1513         struct xunpgen *xug;
 1514         struct unp_head *head;
 1515         struct xunpcb *xu;
 1516 
 1517         switch ((intptr_t)arg1) {
 1518         case SOCK_STREAM:
 1519                 head = &unp_shead;
 1520                 break;
 1521 
 1522         case SOCK_DGRAM:
 1523                 head = &unp_dhead;
 1524                 break;
 1525 
 1526         case SOCK_SEQPACKET:
 1527                 head = &unp_sphead;
 1528                 break;
 1529 
 1530         default:
 1531                 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1);
 1532         }
 1533 
 1534         /*
 1535          * The process of preparing the PCB list is too time-consuming and
 1536          * resource-intensive to repeat twice on every request.
 1537          */
 1538         if (req->oldptr == NULL) {
 1539                 n = unp_count;
 1540                 req->oldidx = 2 * (sizeof *xug)
 1541                         + (n + n/8) * sizeof(struct xunpcb);
 1542                 return (0);
 1543         }
 1544 
 1545         if (req->newptr != NULL)
 1546                 return (EPERM);
 1547 
 1548         /*
 1549          * OK, now we're committed to doing something.
 1550          */
 1551         xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK);
 1552         UNP_LIST_LOCK();
 1553         gencnt = unp_gencnt;
 1554         n = unp_count;
 1555         UNP_LIST_UNLOCK();
 1556 
 1557         xug->xug_len = sizeof *xug;
 1558         xug->xug_count = n;
 1559         xug->xug_gen = gencnt;
 1560         xug->xug_sogen = so_gencnt;
 1561         error = SYSCTL_OUT(req, xug, sizeof *xug);
 1562         if (error) {
 1563                 free(xug, M_TEMP);
 1564                 return (error);
 1565         }
 1566 
 1567         unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
 1568 
 1569         UNP_LIST_LOCK();
 1570         for (unp = LIST_FIRST(head), i = 0; unp && i < n;
 1571              unp = LIST_NEXT(unp, unp_link)) {
 1572                 UNP_PCB_LOCK(unp);
 1573                 if (unp->unp_gencnt <= gencnt) {
 1574                         if (cr_cansee(req->td->td_ucred,
 1575                             unp->unp_socket->so_cred)) {
 1576                                 UNP_PCB_UNLOCK(unp);
 1577                                 continue;
 1578                         }
 1579                         unp_list[i++] = unp;
 1580                         unp->unp_refcount++;
 1581                 }
 1582                 UNP_PCB_UNLOCK(unp);
 1583         }
 1584         UNP_LIST_UNLOCK();
 1585         n = i;                  /* In case we lost some during malloc. */
 1586 
 1587         error = 0;
 1588         xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
 1589         for (i = 0; i < n; i++) {
 1590                 unp = unp_list[i];
 1591                 UNP_PCB_LOCK(unp);
 1592                 unp->unp_refcount--;
 1593                 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) {
 1594                         xu->xu_len = sizeof *xu;
 1595                         xu->xu_unpp = unp;
 1596                         /*
 1597                          * XXX - need more locking here to protect against
 1598                          * connect/disconnect races for SMP.
 1599                          */
 1600                         if (unp->unp_addr != NULL)
 1601                                 bcopy(unp->unp_addr, &xu->xu_addr,
 1602                                       unp->unp_addr->sun_len);
 1603                         if (unp->unp_conn != NULL &&
 1604                             unp->unp_conn->unp_addr != NULL)
 1605                                 bcopy(unp->unp_conn->unp_addr,
 1606                                       &xu->xu_caddr,
 1607                                       unp->unp_conn->unp_addr->sun_len);
 1608                         bcopy(unp, &xu->xu_unp, sizeof *unp);
 1609                         sotoxsocket(unp->unp_socket, &xu->xu_socket);
 1610                         UNP_PCB_UNLOCK(unp);
 1611                         error = SYSCTL_OUT(req, xu, sizeof *xu);
 1612                 } else {
 1613                         freeunp = (unp->unp_refcount == 0);
 1614                         UNP_PCB_UNLOCK(unp);
 1615                         if (freeunp) {
 1616                                 UNP_PCB_LOCK_DESTROY(unp);
 1617                                 uma_zfree(unp_zone, unp);
 1618                         }
 1619                 }
 1620         }
 1621         free(xu, M_TEMP);
 1622         if (!error) {
 1623                 /*
 1624                  * Give the user an updated idea of our state.  If the
 1625                  * generation differs from what we told her before, she knows
 1626                  * that something happened while we were processing this
 1627                  * request, and it might be necessary to retry.
 1628                  */
 1629                 xug->xug_gen = unp_gencnt;
 1630                 xug->xug_sogen = so_gencnt;
 1631                 xug->xug_count = unp_count;
 1632                 error = SYSCTL_OUT(req, xug, sizeof *xug);
 1633         }
 1634         free(unp_list, M_TEMP);
 1635         free(xug, M_TEMP);
 1636         return (error);
 1637 }
 1638 
 1639 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
 1640     (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
 1641     "List of active local datagram sockets");
 1642 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
 1643     (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
 1644     "List of active local stream sockets");
 1645 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist,
 1646     CTLTYPE_OPAQUE | CTLFLAG_RD,
 1647     (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb",
 1648     "List of active local seqpacket sockets");
 1649 
 1650 static void
 1651 unp_shutdown(struct unpcb *unp)
 1652 {
 1653         struct unpcb *unp2;
 1654         struct socket *so;
 1655 
 1656         UNP_LINK_WLOCK_ASSERT();
 1657         UNP_PCB_LOCK_ASSERT(unp);
 1658 
 1659         unp2 = unp->unp_conn;
 1660         if ((unp->unp_socket->so_type == SOCK_STREAM ||
 1661             (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) {
 1662                 so = unp2->unp_socket;
 1663                 if (so != NULL)
 1664                         socantrcvmore(so);
 1665         }
 1666 }
 1667 
 1668 static void
 1669 unp_drop(struct unpcb *unp, int errno)
 1670 {
 1671         struct socket *so = unp->unp_socket;
 1672         struct unpcb *unp2;
 1673 
 1674         UNP_LINK_WLOCK_ASSERT();
 1675         UNP_PCB_LOCK_ASSERT(unp);
 1676 
 1677         so->so_error = errno;
 1678         unp2 = unp->unp_conn;
 1679         if (unp2 == NULL)
 1680                 return;
 1681         UNP_PCB_LOCK(unp2);
 1682         unp_disconnect(unp, unp2);
 1683         UNP_PCB_UNLOCK(unp2);
 1684 }
 1685 
 1686 static void
 1687 unp_freerights(struct filedescent **fdep, int fdcount)
 1688 {
 1689         struct file *fp;
 1690         int i;
 1691 
 1692         KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount));
 1693 
 1694         for (i = 0; i < fdcount; i++) {
 1695                 fp = fdep[i]->fde_file;
 1696                 filecaps_free(&fdep[i]->fde_caps);
 1697                 unp_discard(fp);
 1698         }
 1699         free(fdep[0], M_FILECAPS);
 1700 }
 1701 
 1702 static int
 1703 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
 1704 {
 1705         struct thread *td = curthread;          /* XXX */
 1706         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
 1707         int i;
 1708         int *fdp;
 1709         struct filedesc *fdesc = td->td_proc->p_fd;
 1710         struct filedescent *fde, **fdep;
 1711         void *data;
 1712         socklen_t clen = control->m_len, datalen;
 1713         int error, newfds;
 1714         u_int newlen;
 1715 
 1716         UNP_LINK_UNLOCK_ASSERT();
 1717 
 1718         error = 0;
 1719         if (controlp != NULL) /* controlp == NULL => free control messages */
 1720                 *controlp = NULL;
 1721         while (cm != NULL) {
 1722                 if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
 1723                         error = EINVAL;
 1724                         break;
 1725                 }
 1726                 data = CMSG_DATA(cm);
 1727                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
 1728                 if (cm->cmsg_level == SOL_SOCKET
 1729                     && cm->cmsg_type == SCM_RIGHTS) {
 1730                         newfds = datalen / sizeof(*fdep);
 1731                         if (newfds == 0)
 1732                                 goto next;
 1733                         fdep = data;
 1734 
 1735                         /* If we're not outputting the descriptors free them. */
 1736                         if (error || controlp == NULL) {
 1737                                 unp_freerights(fdep, newfds);
 1738                                 goto next;
 1739                         }
 1740                         FILEDESC_XLOCK(fdesc);
 1741 
 1742                         /*
 1743                          * Now change each pointer to an fd in the global
 1744                          * table to an integer that is the index to the local
 1745                          * fd table entry that we set up to point to the
 1746                          * global one we are transferring.
 1747                          */
 1748                         newlen = newfds * sizeof(int);
 1749                         *controlp = sbcreatecontrol(NULL, newlen,
 1750                             SCM_RIGHTS, SOL_SOCKET);
 1751                         if (*controlp == NULL) {
 1752                                 FILEDESC_XUNLOCK(fdesc);
 1753                                 error = E2BIG;
 1754                                 unp_freerights(fdep, newfds);
 1755                                 goto next;
 1756                         }
 1757 
 1758                         fdp = (int *)
 1759                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 1760                         if (fdallocn(td, 0, fdp, newfds) != 0) {
 1761                                 FILEDESC_XUNLOCK(td->td_proc->p_fd);
 1762                                 error = EMSGSIZE;
 1763                                 unp_freerights(fdep, newfds);
 1764                                 m_freem(*controlp);
 1765                                 *controlp = NULL;
 1766                                 goto next;
 1767                         }
 1768                         for (i = 0; i < newfds; i++, fdp++) {
 1769                                 fde = &fdesc->fd_ofiles[*fdp];
 1770                                 fde->fde_file = fdep[i]->fde_file;
 1771                                 filecaps_move(&fdep[i]->fde_caps,
 1772                                     &fde->fde_caps);
 1773                                 if ((flags & MSG_CMSG_CLOEXEC) != 0)
 1774                                         fde->fde_flags |= UF_EXCLOSE;
 1775                                 unp_externalize_fp(fde->fde_file);
 1776                         }
 1777                         FILEDESC_XUNLOCK(fdesc);
 1778                         free(fdep[0], M_FILECAPS);
 1779                 } else {
 1780                         /* We can just copy anything else across. */
 1781                         if (error || controlp == NULL)
 1782                                 goto next;
 1783                         *controlp = sbcreatecontrol(NULL, datalen,
 1784                             cm->cmsg_type, cm->cmsg_level);
 1785                         if (*controlp == NULL) {
 1786                                 error = ENOBUFS;
 1787                                 goto next;
 1788                         }
 1789                         bcopy(data,
 1790                             CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
 1791                             datalen);
 1792                 }
 1793                 controlp = &(*controlp)->m_next;
 1794 
 1795 next:
 1796                 if (CMSG_SPACE(datalen) < clen) {
 1797                         clen -= CMSG_SPACE(datalen);
 1798                         cm = (struct cmsghdr *)
 1799                             ((caddr_t)cm + CMSG_SPACE(datalen));
 1800                 } else {
 1801                         clen = 0;
 1802                         cm = NULL;
 1803                 }
 1804         }
 1805 
 1806         m_freem(control);
 1807         return (error);
 1808 }
 1809 
 1810 static void
 1811 unp_zone_change(void *tag)
 1812 {
 1813 
 1814         uma_zone_set_max(unp_zone, maxsockets);
 1815 }
 1816 
 1817 static void
 1818 unp_init(void)
 1819 {
 1820 
 1821 #ifdef VIMAGE
 1822         if (!IS_DEFAULT_VNET(curvnet))
 1823                 return;
 1824 #endif
 1825         unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL,
 1826             NULL, NULL, UMA_ALIGN_PTR, 0);
 1827         if (unp_zone == NULL)
 1828                 panic("unp_init");
 1829         uma_zone_set_max(unp_zone, maxsockets);
 1830         uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached");
 1831         EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
 1832             NULL, EVENTHANDLER_PRI_ANY);
 1833         LIST_INIT(&unp_dhead);
 1834         LIST_INIT(&unp_shead);
 1835         LIST_INIT(&unp_sphead);
 1836         SLIST_INIT(&unp_defers);
 1837         TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL);
 1838         TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL);
 1839         UNP_LINK_LOCK_INIT();
 1840         UNP_LIST_LOCK_INIT();
 1841         UNP_DEFERRED_LOCK_INIT();
 1842 }
 1843 
 1844 static int
 1845 unp_internalize(struct mbuf **controlp, struct thread *td)
 1846 {
 1847         struct mbuf *control = *controlp;
 1848         struct proc *p = td->td_proc;
 1849         struct filedesc *fdesc = p->p_fd;
 1850         struct bintime *bt;
 1851         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
 1852         struct cmsgcred *cmcred;
 1853         struct filedescent *fde, **fdep, *fdev;
 1854         struct file *fp;
 1855         struct timeval *tv;
 1856         int i, *fdp;
 1857         void *data;
 1858         socklen_t clen = control->m_len, datalen;
 1859         int error, oldfds;
 1860         u_int newlen;
 1861 
 1862         UNP_LINK_UNLOCK_ASSERT();
 1863 
 1864         error = 0;
 1865         *controlp = NULL;
 1866         while (cm != NULL) {
 1867                 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET
 1868                     || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) {
 1869                         error = EINVAL;
 1870                         goto out;
 1871                 }
 1872                 data = CMSG_DATA(cm);
 1873                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
 1874 
 1875                 switch (cm->cmsg_type) {
 1876                 /*
 1877                  * Fill in credential information.
 1878                  */
 1879                 case SCM_CREDS:
 1880                         *controlp = sbcreatecontrol(NULL, sizeof(*cmcred),
 1881                             SCM_CREDS, SOL_SOCKET);
 1882                         if (*controlp == NULL) {
 1883                                 error = ENOBUFS;
 1884                                 goto out;
 1885                         }
 1886                         cmcred = (struct cmsgcred *)
 1887                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 1888                         cmcred->cmcred_pid = p->p_pid;
 1889                         cmcred->cmcred_uid = td->td_ucred->cr_ruid;
 1890                         cmcred->cmcred_gid = td->td_ucred->cr_rgid;
 1891                         cmcred->cmcred_euid = td->td_ucred->cr_uid;
 1892                         cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups,
 1893                             CMGROUP_MAX);
 1894                         for (i = 0; i < cmcred->cmcred_ngroups; i++)
 1895                                 cmcred->cmcred_groups[i] =
 1896                                     td->td_ucred->cr_groups[i];
 1897                         break;
 1898 
 1899                 case SCM_RIGHTS:
 1900                         oldfds = datalen / sizeof (int);
 1901                         if (oldfds == 0)
 1902                                 break;
 1903                         /*
 1904                          * Check that all the FDs passed in refer to legal
 1905                          * files.  If not, reject the entire operation.
 1906                          */
 1907                         fdp = data;
 1908                         FILEDESC_SLOCK(fdesc);
 1909                         for (i = 0; i < oldfds; i++, fdp++) {
 1910                                 fp = fget_locked(fdesc, *fdp);
 1911                                 if (fp == NULL) {
 1912                                         FILEDESC_SUNLOCK(fdesc);
 1913                                         error = EBADF;
 1914                                         goto out;
 1915                                 }
 1916                                 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
 1917                                         FILEDESC_SUNLOCK(fdesc);
 1918                                         error = EOPNOTSUPP;
 1919                                         goto out;
 1920                                 }
 1921 
 1922                         }
 1923 
 1924                         /*
 1925                          * Now replace the integer FDs with pointers to the
 1926                          * file structure and capability rights.
 1927                          */
 1928                         newlen = oldfds * sizeof(fdep[0]);
 1929                         *controlp = sbcreatecontrol(NULL, newlen,
 1930                             SCM_RIGHTS, SOL_SOCKET);
 1931                         if (*controlp == NULL) {
 1932                                 FILEDESC_SUNLOCK(fdesc);
 1933                                 error = E2BIG;
 1934                                 goto out;
 1935                         }
 1936                         fdp = data;
 1937                         fdep = (struct filedescent **)
 1938                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 1939                         fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS,
 1940                             M_WAITOK);
 1941                         for (i = 0; i < oldfds; i++, fdev++, fdp++) {
 1942                                 fde = &fdesc->fd_ofiles[*fdp];
 1943                                 fdep[i] = fdev;
 1944                                 fdep[i]->fde_file = fde->fde_file;
 1945                                 filecaps_copy(&fde->fde_caps,
 1946                                     &fdep[i]->fde_caps);
 1947                                 unp_internalize_fp(fdep[i]->fde_file);
 1948                         }
 1949                         FILEDESC_SUNLOCK(fdesc);
 1950                         break;
 1951 
 1952                 case SCM_TIMESTAMP:
 1953                         *controlp = sbcreatecontrol(NULL, sizeof(*tv),
 1954                             SCM_TIMESTAMP, SOL_SOCKET);
 1955                         if (*controlp == NULL) {
 1956                                 error = ENOBUFS;
 1957                                 goto out;
 1958                         }
 1959                         tv = (struct timeval *)
 1960                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 1961                         microtime(tv);
 1962                         break;
 1963 
 1964                 case SCM_BINTIME:
 1965                         *controlp = sbcreatecontrol(NULL, sizeof(*bt),
 1966                             SCM_BINTIME, SOL_SOCKET);
 1967                         if (*controlp == NULL) {
 1968                                 error = ENOBUFS;
 1969                                 goto out;
 1970                         }
 1971                         bt = (struct bintime *)
 1972                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
 1973                         bintime(bt);
 1974                         break;
 1975 
 1976                 default:
 1977                         error = EINVAL;
 1978                         goto out;
 1979                 }
 1980 
 1981                 controlp = &(*controlp)->m_next;
 1982                 if (CMSG_SPACE(datalen) < clen) {
 1983                         clen -= CMSG_SPACE(datalen);
 1984                         cm = (struct cmsghdr *)
 1985                             ((caddr_t)cm + CMSG_SPACE(datalen));
 1986                 } else {
 1987                         clen = 0;
 1988                         cm = NULL;
 1989                 }
 1990         }
 1991 
 1992 out:
 1993         m_freem(control);
 1994         return (error);
 1995 }
 1996 
 1997 static struct mbuf *
 1998 unp_addsockcred(struct thread *td, struct mbuf *control)
 1999 {
 2000         struct mbuf *m, *n, *n_prev;
 2001         struct sockcred *sc;
 2002         const struct cmsghdr *cm;
 2003         int ngroups;
 2004         int i;
 2005 
 2006         ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
 2007         m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET);
 2008         if (m == NULL)
 2009                 return (control);
 2010 
 2011         sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *));
 2012         sc->sc_uid = td->td_ucred->cr_ruid;
 2013         sc->sc_euid = td->td_ucred->cr_uid;
 2014         sc->sc_gid = td->td_ucred->cr_rgid;
 2015         sc->sc_egid = td->td_ucred->cr_gid;
 2016         sc->sc_ngroups = ngroups;
 2017         for (i = 0; i < sc->sc_ngroups; i++)
 2018                 sc->sc_groups[i] = td->td_ucred->cr_groups[i];
 2019 
 2020         /*
 2021          * Unlink SCM_CREDS control messages (struct cmsgcred), since just
 2022          * created SCM_CREDS control message (struct sockcred) has another
 2023          * format.
 2024          */
 2025         if (control != NULL)
 2026                 for (n = control, n_prev = NULL; n != NULL;) {
 2027                         cm = mtod(n, struct cmsghdr *);
 2028                         if (cm->cmsg_level == SOL_SOCKET &&
 2029                             cm->cmsg_type == SCM_CREDS) {
 2030                                 if (n_prev == NULL)
 2031                                         control = n->m_next;
 2032                                 else
 2033                                         n_prev->m_next = n->m_next;
 2034                                 n = m_free(n);
 2035                         } else {
 2036                                 n_prev = n;
 2037                                 n = n->m_next;
 2038                         }
 2039                 }
 2040 
 2041         /* Prepend it to the head. */
 2042         m->m_next = control;
 2043         return (m);
 2044 }
 2045 
 2046 static struct unpcb *
 2047 fptounp(struct file *fp)
 2048 {
 2049         struct socket *so;
 2050 
 2051         if (fp->f_type != DTYPE_SOCKET)
 2052                 return (NULL);
 2053         if ((so = fp->f_data) == NULL)
 2054                 return (NULL);
 2055         if (so->so_proto->pr_domain != &localdomain)
 2056                 return (NULL);
 2057         return sotounpcb(so);
 2058 }
 2059 
 2060 static void
 2061 unp_discard(struct file *fp)
 2062 {
 2063         struct unp_defer *dr;
 2064 
 2065         if (unp_externalize_fp(fp)) {
 2066                 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK);
 2067                 dr->ud_fp = fp;
 2068                 UNP_DEFERRED_LOCK();
 2069                 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link);
 2070                 UNP_DEFERRED_UNLOCK();
 2071                 atomic_add_int(&unp_defers_count, 1);
 2072                 taskqueue_enqueue(taskqueue_thread, &unp_defer_task);
 2073         } else
 2074                 (void) closef(fp, (struct thread *)NULL);
 2075 }
 2076 
 2077 static void
 2078 unp_process_defers(void *arg __unused, int pending)
 2079 {
 2080         struct unp_defer *dr;
 2081         SLIST_HEAD(, unp_defer) drl;
 2082         int count;
 2083 
 2084         SLIST_INIT(&drl);
 2085         for (;;) {
 2086                 UNP_DEFERRED_LOCK();
 2087                 if (SLIST_FIRST(&unp_defers) == NULL) {
 2088                         UNP_DEFERRED_UNLOCK();
 2089                         break;
 2090                 }
 2091                 SLIST_SWAP(&unp_defers, &drl, unp_defer);
 2092                 UNP_DEFERRED_UNLOCK();
 2093                 count = 0;
 2094                 while ((dr = SLIST_FIRST(&drl)) != NULL) {
 2095                         SLIST_REMOVE_HEAD(&drl, ud_link);
 2096                         closef(dr->ud_fp, NULL);
 2097                         free(dr, M_TEMP);
 2098                         count++;
 2099                 }
 2100                 atomic_add_int(&unp_defers_count, -count);
 2101         }
 2102 }
 2103 
 2104 static void
 2105 unp_internalize_fp(struct file *fp)
 2106 {
 2107         struct unpcb *unp;
 2108 
 2109         UNP_LINK_WLOCK();
 2110         if ((unp = fptounp(fp)) != NULL) {
 2111                 unp->unp_file = fp;
 2112                 unp->unp_msgcount++;
 2113         }
 2114         fhold(fp);
 2115         unp_rights++;
 2116         UNP_LINK_WUNLOCK();
 2117 }
 2118 
 2119 static int
 2120 unp_externalize_fp(struct file *fp)
 2121 {
 2122         struct unpcb *unp;
 2123         int ret;
 2124 
 2125         UNP_LINK_WLOCK();
 2126         if ((unp = fptounp(fp)) != NULL) {
 2127                 unp->unp_msgcount--;
 2128                 ret = 1;
 2129         } else
 2130                 ret = 0;
 2131         unp_rights--;
 2132         UNP_LINK_WUNLOCK();
 2133         return (ret);
 2134 }
 2135 
 2136 /*
 2137  * unp_defer indicates whether additional work has been defered for a future
 2138  * pass through unp_gc().  It is thread local and does not require explicit
 2139  * synchronization.
 2140  */
 2141 static int      unp_marked;
 2142 static int      unp_unreachable;
 2143 
 2144 static void
 2145 unp_accessable(struct filedescent **fdep, int fdcount)
 2146 {
 2147         struct unpcb *unp;
 2148         struct file *fp;
 2149         int i;
 2150 
 2151         for (i = 0; i < fdcount; i++) {
 2152                 fp = fdep[i]->fde_file;
 2153                 if ((unp = fptounp(fp)) == NULL)
 2154                         continue;
 2155                 if (unp->unp_gcflag & UNPGC_REF)
 2156                         continue;
 2157                 unp->unp_gcflag &= ~UNPGC_DEAD;
 2158                 unp->unp_gcflag |= UNPGC_REF;
 2159                 unp_marked++;
 2160         }
 2161 }
 2162 
 2163 static void
 2164 unp_gc_process(struct unpcb *unp)
 2165 {
 2166         struct socket *soa;
 2167         struct socket *so;
 2168         struct file *fp;
 2169 
 2170         /* Already processed. */
 2171         if (unp->unp_gcflag & UNPGC_SCANNED)
 2172                 return;
 2173         fp = unp->unp_file;
 2174 
 2175         /*
 2176          * Check for a socket potentially in a cycle.  It must be in a
 2177          * queue as indicated by msgcount, and this must equal the file
 2178          * reference count.  Note that when msgcount is 0 the file is NULL.
 2179          */
 2180         if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp &&
 2181             unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) {
 2182                 unp->unp_gcflag |= UNPGC_DEAD;
 2183                 unp_unreachable++;
 2184                 return;
 2185         }
 2186 
 2187         /*
 2188          * Mark all sockets we reference with RIGHTS.
 2189          */
 2190         so = unp->unp_socket;
 2191         SOCKBUF_LOCK(&so->so_rcv);
 2192         unp_scan(so->so_rcv.sb_mb, unp_accessable);
 2193         SOCKBUF_UNLOCK(&so->so_rcv);
 2194 
 2195         /*
 2196          * Mark all sockets in our accept queue.
 2197          */
 2198         ACCEPT_LOCK();
 2199         TAILQ_FOREACH(soa, &so->so_comp, so_list) {
 2200                 SOCKBUF_LOCK(&soa->so_rcv);
 2201                 unp_scan(soa->so_rcv.sb_mb, unp_accessable);
 2202                 SOCKBUF_UNLOCK(&soa->so_rcv);
 2203         }
 2204         ACCEPT_UNLOCK();
 2205         unp->unp_gcflag |= UNPGC_SCANNED;
 2206 }
 2207 
 2208 static int unp_recycled;
 2209 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 
 2210     "Number of unreachable sockets claimed by the garbage collector.");
 2211 
 2212 static int unp_taskcount;
 2213 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 
 2214     "Number of times the garbage collector has run.");
 2215 
 2216 static void
 2217 unp_gc(__unused void *arg, int pending)
 2218 {
 2219         struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead,
 2220                                     NULL };
 2221         struct unp_head **head;
 2222         struct file *f, **unref;
 2223         struct unpcb *unp;
 2224         int i, total;
 2225 
 2226         unp_taskcount++;
 2227         UNP_LIST_LOCK();
 2228         /*
 2229          * First clear all gc flags from previous runs.
 2230          */
 2231         for (head = heads; *head != NULL; head++)
 2232                 LIST_FOREACH(unp, *head, unp_link)
 2233                         unp->unp_gcflag = 0;
 2234 
 2235         /*
 2236          * Scan marking all reachable sockets with UNPGC_REF.  Once a socket
 2237          * is reachable all of the sockets it references are reachable.
 2238          * Stop the scan once we do a complete loop without discovering
 2239          * a new reachable socket.
 2240          */
 2241         do {
 2242                 unp_unreachable = 0;
 2243                 unp_marked = 0;
 2244                 for (head = heads; *head != NULL; head++)
 2245                         LIST_FOREACH(unp, *head, unp_link)
 2246                                 unp_gc_process(unp);
 2247         } while (unp_marked);
 2248         UNP_LIST_UNLOCK();
 2249         if (unp_unreachable == 0)
 2250                 return;
 2251 
 2252         /*
 2253          * Allocate space for a local list of dead unpcbs.
 2254          */
 2255         unref = malloc(unp_unreachable * sizeof(struct file *),
 2256             M_TEMP, M_WAITOK);
 2257 
 2258         /*
 2259          * Iterate looking for sockets which have been specifically marked
 2260          * as as unreachable and store them locally.
 2261          */
 2262         UNP_LINK_RLOCK();
 2263         UNP_LIST_LOCK();
 2264         for (total = 0, head = heads; *head != NULL; head++)
 2265                 LIST_FOREACH(unp, *head, unp_link)
 2266                         if ((unp->unp_gcflag & UNPGC_DEAD) != 0) {
 2267                                 f = unp->unp_file;
 2268                                 if (unp->unp_msgcount == 0 || f == NULL ||
 2269                                     f->f_count != unp->unp_msgcount)
 2270                                         continue;
 2271                                 unref[total++] = f;
 2272                                 fhold(f);
 2273                                 KASSERT(total <= unp_unreachable,
 2274                                     ("unp_gc: incorrect unreachable count."));
 2275                         }
 2276         UNP_LIST_UNLOCK();
 2277         UNP_LINK_RUNLOCK();
 2278 
 2279         /*
 2280          * Now flush all sockets, free'ing rights.  This will free the
 2281          * struct files associated with these sockets but leave each socket
 2282          * with one remaining ref.
 2283          */
 2284         for (i = 0; i < total; i++) {
 2285                 struct socket *so;
 2286 
 2287                 so = unref[i]->f_data;
 2288                 CURVNET_SET(so->so_vnet);
 2289                 sorflush(so);
 2290                 CURVNET_RESTORE();
 2291         }
 2292 
 2293         /*
 2294          * And finally release the sockets so they can be reclaimed.
 2295          */
 2296         for (i = 0; i < total; i++)
 2297                 fdrop(unref[i], NULL);
 2298         unp_recycled += total;
 2299         free(unref, M_TEMP);
 2300 }
 2301 
 2302 static void
 2303 unp_dispose(struct mbuf *m)
 2304 {
 2305 
 2306         if (m)
 2307                 unp_scan(m, unp_freerights);
 2308 }
 2309 
 2310 static void
 2311 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int))
 2312 {
 2313         struct mbuf *m;
 2314         struct cmsghdr *cm;
 2315         void *data;
 2316         socklen_t clen, datalen;
 2317 
 2318         while (m0 != NULL) {
 2319                 for (m = m0; m; m = m->m_next) {
 2320                         if (m->m_type != MT_CONTROL)
 2321                                 continue;
 2322 
 2323                         cm = mtod(m, struct cmsghdr *);
 2324                         clen = m->m_len;
 2325 
 2326                         while (cm != NULL) {
 2327                                 if (sizeof(*cm) > clen || cm->cmsg_len > clen)
 2328                                         break;
 2329 
 2330                                 data = CMSG_DATA(cm);
 2331                                 datalen = (caddr_t)cm + cm->cmsg_len
 2332                                     - (caddr_t)data;
 2333 
 2334                                 if (cm->cmsg_level == SOL_SOCKET &&
 2335                                     cm->cmsg_type == SCM_RIGHTS) {
 2336                                         (*op)(data, datalen /
 2337                                             sizeof(struct filedescent *));
 2338                                 }
 2339 
 2340                                 if (CMSG_SPACE(datalen) < clen) {
 2341                                         clen -= CMSG_SPACE(datalen);
 2342                                         cm = (struct cmsghdr *)
 2343                                             ((caddr_t)cm + CMSG_SPACE(datalen));
 2344                                 } else {
 2345                                         clen = 0;
 2346                                         cm = NULL;
 2347                                 }
 2348                         }
 2349                 }
 2350                 m0 = m0->m_nextpkt;
 2351         }
 2352 }
 2353 
 2354 /*
 2355  * A helper function called by VFS before socket-type vnode reclamation.
 2356  * For an active vnode it clears unp_vnode pointer and decrements unp_vnode
 2357  * use count.
 2358  */
 2359 void
 2360 vfs_unp_reclaim(struct vnode *vp)
 2361 {
 2362         struct socket *so;
 2363         struct unpcb *unp;
 2364         int active;
 2365 
 2366         ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim");
 2367         KASSERT(vp->v_type == VSOCK,
 2368             ("vfs_unp_reclaim: vp->v_type != VSOCK"));
 2369 
 2370         active = 0;
 2371         UNP_LINK_WLOCK();
 2372         VOP_UNP_CONNECT(vp, &so);
 2373         if (so == NULL)
 2374                 goto done;
 2375         unp = sotounpcb(so);
 2376         if (unp == NULL)
 2377                 goto done;
 2378         UNP_PCB_LOCK(unp);
 2379         if (unp->unp_vnode == vp) {
 2380                 VOP_UNP_DETACH(vp);
 2381                 unp->unp_vnode = NULL;
 2382                 active = 1;
 2383         }
 2384         UNP_PCB_UNLOCK(unp);
 2385 done:
 2386         UNP_LINK_WUNLOCK();
 2387         if (active)
 2388                 vunref(vp);
 2389 }
 2390 
 2391 #ifdef DDB
 2392 static void
 2393 db_print_indent(int indent)
 2394 {
 2395         int i;
 2396 
 2397         for (i = 0; i < indent; i++)
 2398                 db_printf(" ");
 2399 }
 2400 
 2401 static void
 2402 db_print_unpflags(int unp_flags)
 2403 {
 2404         int comma;
 2405 
 2406         comma = 0;
 2407         if (unp_flags & UNP_HAVEPC) {
 2408                 db_printf("%sUNP_HAVEPC", comma ? ", " : "");
 2409                 comma = 1;
 2410         }
 2411         if (unp_flags & UNP_HAVEPCCACHED) {
 2412                 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : "");
 2413                 comma = 1;
 2414         }
 2415         if (unp_flags & UNP_WANTCRED) {
 2416                 db_printf("%sUNP_WANTCRED", comma ? ", " : "");
 2417                 comma = 1;
 2418         }
 2419         if (unp_flags & UNP_CONNWAIT) {
 2420                 db_printf("%sUNP_CONNWAIT", comma ? ", " : "");
 2421                 comma = 1;
 2422         }
 2423         if (unp_flags & UNP_CONNECTING) {
 2424                 db_printf("%sUNP_CONNECTING", comma ? ", " : "");
 2425                 comma = 1;
 2426         }
 2427         if (unp_flags & UNP_BINDING) {
 2428                 db_printf("%sUNP_BINDING", comma ? ", " : "");
 2429                 comma = 1;
 2430         }
 2431 }
 2432 
 2433 static void
 2434 db_print_xucred(int indent, struct xucred *xu)
 2435 {
 2436         int comma, i;
 2437 
 2438         db_print_indent(indent);
 2439         db_printf("cr_version: %u   cr_uid: %u   cr_ngroups: %d\n",
 2440             xu->cr_version, xu->cr_uid, xu->cr_ngroups);
 2441         db_print_indent(indent);
 2442         db_printf("cr_groups: ");
 2443         comma = 0;
 2444         for (i = 0; i < xu->cr_ngroups; i++) {
 2445                 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
 2446                 comma = 1;
 2447         }
 2448         db_printf("\n");
 2449 }
 2450 
 2451 static void
 2452 db_print_unprefs(int indent, struct unp_head *uh)
 2453 {
 2454         struct unpcb *unp;
 2455         int counter;
 2456 
 2457         counter = 0;
 2458         LIST_FOREACH(unp, uh, unp_reflink) {
 2459                 if (counter % 4 == 0)
 2460                         db_print_indent(indent);
 2461                 db_printf("%p  ", unp);
 2462                 if (counter % 4 == 3)
 2463                         db_printf("\n");
 2464                 counter++;
 2465         }
 2466         if (counter != 0 && counter % 4 != 0)
 2467                 db_printf("\n");
 2468 }
 2469 
 2470 DB_SHOW_COMMAND(unpcb, db_show_unpcb)
 2471 {
 2472         struct unpcb *unp;
 2473 
 2474         if (!have_addr) {
 2475                 db_printf("usage: show unpcb <addr>\n");
 2476                 return;
 2477         }
 2478         unp = (struct unpcb *)addr;
 2479 
 2480         db_printf("unp_socket: %p   unp_vnode: %p\n", unp->unp_socket,
 2481             unp->unp_vnode);
 2482 
 2483         db_printf("unp_ino: %ju   unp_conn: %p\n", (uintmax_t)unp->unp_ino,
 2484             unp->unp_conn);
 2485 
 2486         db_printf("unp_refs:\n");
 2487         db_print_unprefs(2, &unp->unp_refs);
 2488 
 2489         /* XXXRW: Would be nice to print the full address, if any. */
 2490         db_printf("unp_addr: %p\n", unp->unp_addr);
 2491 
 2492         db_printf("unp_gencnt: %llu\n",
 2493             (unsigned long long)unp->unp_gencnt);
 2494 
 2495         db_printf("unp_flags: %x (", unp->unp_flags);
 2496         db_print_unpflags(unp->unp_flags);
 2497         db_printf(")\n");
 2498 
 2499         db_printf("unp_peercred:\n");
 2500         db_print_xucred(2, &unp->unp_peercred);
 2501 
 2502         db_printf("unp_refcount: %u\n", unp->unp_refcount);
 2503 }
 2504 #endif

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