sys/kern/uipc_usrreq.c

   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  * 3. 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("$FreeBSD$");
  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  * Two types of locks exist in the local domain socket implementation: a
 193  * a global linkage rwlock and per-unpcb mutexes.  The linkage lock protects
 194  * the socket count, global generation number, stream/datagram global lists and
 195  * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be
 196  * held exclusively over the acquisition of multiple unpcb locks to prevent
 197  * deadlock.
 198  *
 199  * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer,
 200  * allocated in pru_attach() and freed in pru_detach().  The validity of that
 201  * pointer is an invariant, so no lock is required to dereference the so_pcb
 202  * pointer if a valid socket reference is held by the caller.  In practice,
 203  * this is always true during operations performed on a socket.  Each unpcb
 204  * has a back-pointer to its socket, unp_socket, which will be stable under
 205  * the same circumstances.
 206  *
 207  * This pointer may only be safely dereferenced as long as a valid reference
 208  * to the unpcb is held.  Typically, this reference will be from the socket,
 209  * or from another unpcb when the referring unpcb's lock is held (in order
 210  * that the reference not be invalidated during use).  For example, to follow
 211  * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn,
 212  * as unp_socket remains valid as long as the reference to unp_conn is valid.
 213  *
 214  * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx.  Individual
 215  * atomic reads without the lock may be performed "lockless", but more
 216  * complex reads and read-modify-writes require the mutex to be held.  No
 217  * lock order is defined between unpcb locks -- multiple unpcb locks may be
 218  * acquired at the same time only when holding the linkage rwlock
 219  * exclusively, which prevents deadlocks.
 220  *
 221  * Blocking with UNIX domain sockets is a tricky issue: unlike most network
 222  * protocols, bind() is a non-atomic operation, and connect() requires
 223  * potential sleeping in the protocol, due to potentially waiting on local or
 224  * distributed file systems.  We try to separate "lookup" operations, which
 225  * may sleep, and the IPC operations themselves, which typically can occur
 226  * with relative atomicity as locks can be held over the entire operation.
 227  *
 228  * Another tricky issue is simultaneous multi-threaded or multi-process
 229  * access to a single UNIX domain socket.  These are handled by the flags
 230  * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or
 231  * binding, both of which involve dropping UNIX domain socket locks in order
 232  * to perform namei() and other file system operations.
 233  */
 234 static struct rwlock    unp_link_rwlock;
 235 static struct mtx       unp_defers_lock;
 236
 237 #define UNP_LINK_LOCK_INIT()            rw_init(&unp_link_rwlock,       \
 238                                             "unp_link_rwlock")
 239
 240 #define UNP_LINK_LOCK_ASSERT()  rw_assert(&unp_link_rwlock,     \
 241                                             RA_LOCKED)
 242 #define UNP_LINK_UNLOCK_ASSERT()        rw_assert(&unp_link_rwlock,     \
 243                                             RA_UNLOCKED)
 244
 245 #define UNP_LINK_RLOCK()                rw_rlock(&unp_link_rwlock)
 246 #define UNP_LINK_RUNLOCK()              rw_runlock(&unp_link_rwlock)
 247 #define UNP_LINK_WLOCK()                rw_wlock(&unp_link_rwlock)
 248 #define UNP_LINK_WUNLOCK()              rw_wunlock(&unp_link_rwlock)
 249 #define UNP_LINK_WLOCK_ASSERT()         rw_assert(&unp_link_rwlock,     \
 250                                             RA_WLOCKED)
 251 #define UNP_LINK_WOWNED()               rw_wowned(&unp_link_rwlock)
 252
 253 #define UNP_DEFERRED_LOCK_INIT()        mtx_init(&unp_defers_lock, \
 254                                             "unp_defer", NULL, MTX_DEF)
 255 #define UNP_DEFERRED_LOCK()             mtx_lock(&unp_defers_lock)
 256 #define UNP_DEFERRED_UNLOCK()           mtx_unlock(&unp_defers_lock)
 257
 258 #define UNP_PCB_LOCK_INIT(unp)          mtx_init(&(unp)->unp_mtx,       \
 259                                             "unp_mtx", "unp_mtx",       \
 260                                             MTX_DUPOK|MTX_DEF|MTX_RECURSE)
 261 #define UNP_PCB_LOCK_DESTROY(unp)       mtx_destroy(&(unp)->unp_mtx)
 262 #define UNP_PCB_LOCK(unp)               mtx_lock(&(unp)->unp_mtx)
 263 #define UNP_PCB_UNLOCK(unp)             mtx_unlock(&(unp)->unp_mtx)
 264 #define UNP_PCB_LOCK_ASSERT(unp)        mtx_assert(&(unp)->unp_mtx, MA_OWNED)
 265
 266 static int      uipc_connect2(struct socket *, struct socket *);
 267 static int      uipc_ctloutput(struct socket *, struct sockopt *);
 268 static int      unp_connect(struct socket *, struct sockaddr *,
 269                     struct thread *);
 270 static int      unp_connectat(int, struct socket *, struct sockaddr *,
 271                     struct thread *);
 272 static int      unp_connect2(struct socket *so, struct socket *so2, int);
 273 static void     unp_disconnect(struct unpcb *unp, struct unpcb *unp2);
 274 static void     unp_dispose(struct socket *so);
 275 static void     unp_dispose_mbuf(struct mbuf *);
 276 static void     unp_shutdown(struct unpcb *);
 277 static void     unp_drop(struct unpcb *);
 278 static void     unp_gc(__unused void *, int);
 279 static void     unp_scan(struct mbuf *, void (*)(struct filedescent **, int));
 280 static void     unp_discard(struct file *);
 281 static void     unp_freerights(struct filedescent **, int);
 282 static void     unp_init(void);
 283 static int      unp_internalize(struct mbuf **, struct thread *);
 284 static void     unp_internalize_fp(struct file *);
 285 static int      unp_externalize(struct mbuf *, struct mbuf **, int);
 286 static int      unp_externalize_fp(struct file *);
 287 static struct mbuf      *unp_addsockcred(struct thread *, struct mbuf *);
 288 static void     unp_process_defers(void * __unused, int);
 289
 290 /*
 291  * Definitions of protocols supported in the LOCAL domain.
 292  */
 293 static struct domain localdomain;
 294 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream;
 295 static struct pr_usrreqs uipc_usrreqs_seqpacket;
 296 static struct protosw localsw[] = {
 297 {
 298         .pr_type =              SOCK_STREAM,
 299         .pr_domain =            &localdomain,
 300         .pr_flags =             PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS,
 301         .pr_ctloutput =         &uipc_ctloutput,
 302         .pr_usrreqs =           &uipc_usrreqs_stream
 303 },
 304 {
 305         .pr_type =              SOCK_DGRAM,
 306         .pr_domain =            &localdomain,
 307         .pr_flags =             PR_ATOMIC|PR_ADDR|PR_RIGHTS,
 308         .pr_ctloutput =         &uipc_ctloutput,
 309         .pr_usrreqs =           &uipc_usrreqs_dgram
 310 },
 311 {
 312         .pr_type =              SOCK_SEQPACKET,
 313         .pr_domain =            &localdomain,
 314
 315         /*
 316          * XXXRW: For now, PR_ADDR because soreceive will bump into them
 317          * due to our use of sbappendaddr.  A new sbappend variants is needed
 318          * that supports both atomic record writes and control data.
 319          */
 320         .pr_flags =             PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD|
 321                                     PR_RIGHTS,
 322         .pr_ctloutput =         &uipc_ctloutput,
 323         .pr_usrreqs =           &uipc_usrreqs_seqpacket,
 324 },
 325 };
 326
 327 static struct domain localdomain = {
 328         .dom_family =           AF_LOCAL,
 329         .dom_name =             "local",
 330         .dom_init =             unp_init,
 331         .dom_externalize =      unp_externalize,
 332         .dom_dispose =          unp_dispose,
 333         .dom_protosw =          localsw,
 334         .dom_protoswNPROTOSW =  &localsw[nitems(localsw)]
 335 };
 336 DOMAIN_SET(local);
 337
 338 static void
 339 uipc_abort(struct socket *so)
 340 {
 341         struct unpcb *unp, *unp2;
 342
 343         unp = sotounpcb(so);
 344         KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
 345
 346         UNP_LINK_WLOCK();
 347         UNP_PCB_LOCK(unp);
 348         unp2 = unp->unp_conn;
 349         if (unp2 != NULL) {
 350                 UNP_PCB_LOCK(unp2);
 351                 unp_drop(unp2);
 352                 UNP_PCB_UNLOCK(unp2);
 353         }
 354         UNP_PCB_UNLOCK(unp);
 355         UNP_LINK_WUNLOCK();
 356 }
 357
 358 static int
 359 uipc_accept(struct socket *so, struct sockaddr **nam)
 360 {
 361         struct unpcb *unp, *unp2;
 362         const struct sockaddr *sa;
 363
 364         /*
 365          * Pass back name of connected socket, if it was bound and we are
 366          * still connected (our peer may have closed already!).
 367          */
 368         unp = sotounpcb(so);
 369         KASSERT(unp != NULL, ("uipc_accept: unp == NULL"));
 370
 371         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 372         UNP_LINK_RLOCK();
 373         unp2 = unp->unp_conn;
 374         if (unp2 != NULL && unp2->unp_addr != NULL) {
 375                 UNP_PCB_LOCK(unp2);
 376                 sa = (struct sockaddr *) unp2->unp_addr;
 377                 bcopy(sa, *nam, sa->sa_len);
 378                 UNP_PCB_UNLOCK(unp2);
 379         } else {
 380                 sa = &sun_noname;
 381                 bcopy(sa, *nam, sa->sa_len);
 382         }
 383         UNP_LINK_RUNLOCK();
 384         return (0);
 385 }
 386
 387 static int
 388 uipc_attach(struct socket *so, int proto, struct thread *td)
 389 {
 390         u_long sendspace, recvspace;
 391         struct unpcb *unp;
 392         int error;
 393         bool locked;
 394
 395         KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
 396         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 397                 switch (so->so_type) {
 398                 case SOCK_STREAM:
 399                         sendspace = unpst_sendspace;
 400                         recvspace = unpst_recvspace;
 401                         break;
 402
 403                 case SOCK_DGRAM:
 404                         sendspace = unpdg_sendspace;
 405                         recvspace = unpdg_recvspace;
 406                         break;
 407
 408                 case SOCK_SEQPACKET:
 409                         sendspace = unpsp_sendspace;
 410                         recvspace = unpsp_recvspace;
 411                         break;
 412
 413                 default:
 414                         panic("uipc_attach");
 415                 }
 416                 error = soreserve(so, sendspace, recvspace);
 417                 if (error)
 418                         return (error);
 419         }
 420         unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
 421         if (unp == NULL)
 422                 return (ENOBUFS);
 423         LIST_INIT(&unp->unp_refs);
 424         UNP_PCB_LOCK_INIT(unp);
 425         unp->unp_socket = so;
 426         so->so_pcb = unp;
 427         unp->unp_refcount = 1;
 428         if (so->so_listen != NULL)
 429                 unp->unp_flags |= UNP_NASCENT;
 430
 431         if ((locked = UNP_LINK_WOWNED()) == false)
 432                 UNP_LINK_WLOCK();
 433
 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
 453         if (locked == false)
 454                 UNP_LINK_WUNLOCK();
 455
 456         return (0);
 457 }
 458
 459 static int
 460 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
 461 {
 462         struct sockaddr_un *soun = (struct sockaddr_un *)nam;
 463         struct vattr vattr;
 464         int error, namelen;
 465         struct nameidata nd;
 466         struct unpcb *unp;
 467         struct vnode *vp;
 468         struct mount *mp;
 469         cap_rights_t rights;
 470         char *buf;
 471
 472         if (nam->sa_family != AF_UNIX)
 473                 return (EAFNOSUPPORT);
 474
 475         unp = sotounpcb(so);
 476         KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
 477
 478         if (soun->sun_len > sizeof(struct sockaddr_un))
 479                 return (EINVAL);
 480         namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
 481         if (namelen <= 0)
 482                 return (EINVAL);
 483
 484         /*
 485          * We don't allow simultaneous bind() calls on a single UNIX domain
 486          * socket, so flag in-progress operations, and return an error if an
 487          * operation is already in progress.
 488          *
 489          * Historically, we have not allowed a socket to be rebound, so this
 490          * also returns an error.  Not allowing re-binding simplifies the
 491          * implementation and avoids a great many possible failure modes.
 492          */
 493         UNP_PCB_LOCK(unp);
 494         if (unp->unp_vnode != NULL) {
 495                 UNP_PCB_UNLOCK(unp);
 496                 return (EINVAL);
 497         }
 498         if (unp->unp_flags & UNP_BINDING) {
 499                 UNP_PCB_UNLOCK(unp);
 500                 return (EALREADY);
 501         }
 502         unp->unp_flags |= UNP_BINDING;
 503         UNP_PCB_UNLOCK(unp);
 504
 505         buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
 506         bcopy(soun->sun_path, buf, namelen);
 507         buf[namelen] = 0;
 508
 509 restart:
 510         NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE,
 511             UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td);
 512 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
 513         error = namei(&nd);
 514         if (error)
 515                 goto error;
 516         vp = nd.ni_vp;
 517         if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 518                 NDFREE(&nd, NDF_ONLY_PNBUF);
 519                 if (nd.ni_dvp == vp)
 520                         vrele(nd.ni_dvp);
 521                 else
 522                         vput(nd.ni_dvp);
 523                 if (vp != NULL) {
 524                         vrele(vp);
 525                         error = EADDRINUSE;
 526                         goto error;
 527                 }
 528                 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
 529                 if (error)
 530                         goto error;
 531                 goto restart;
 532         }
 533         VATTR_NULL(&vattr);
 534         vattr.va_type = VSOCK;
 535         vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask);
 536 #ifdef MAC
 537         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 538             &vattr);
 539 #endif
 540         if (error == 0)
 541                 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
 542         NDFREE(&nd, NDF_ONLY_PNBUF);
 543         vput(nd.ni_dvp);
 544         if (error) {
 545                 vn_finished_write(mp);
 546                 goto error;
 547         }
 548         vp = nd.ni_vp;
 549         ASSERT_VOP_ELOCKED(vp, "uipc_bind");
 550         soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
 551
 552         UNP_LINK_WLOCK();
 553         UNP_PCB_LOCK(unp);
 554         VOP_UNP_BIND(vp, unp);
 555         unp->unp_vnode = vp;
 556         unp->unp_addr = soun;
 557         unp->unp_flags &= ~UNP_BINDING;
 558         UNP_PCB_UNLOCK(unp);
 559         UNP_LINK_WUNLOCK();
 560         VOP_UNLOCK(vp, 0);
 561         vn_finished_write(mp);
 562         free(buf, M_TEMP);
 563         return (0);
 564
 565 error:
 566         UNP_PCB_LOCK(unp);
 567         unp->unp_flags &= ~UNP_BINDING;
 568         UNP_PCB_UNLOCK(unp);
 569         free(buf, M_TEMP);
 570         return (error);
 571 }
 572
 573 static int
 574 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 575 {
 576
 577         return (uipc_bindat(AT_FDCWD, so, nam, td));
 578 }
 579
 580 static int
 581 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 582 {
 583         int error;
 584
 585         KASSERT(td == curthread, ("uipc_connect: td != curthread"));
 586         UNP_LINK_WLOCK();
 587         error = unp_connect(so, nam, td);
 588         UNP_LINK_WUNLOCK();
 589         return (error);
 590 }
 591
 592 static int
 593 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam,
 594     struct thread *td)
 595 {
 596         int error;
 597
 598         KASSERT(td == curthread, ("uipc_connectat: td != curthread"));
 599         UNP_LINK_WLOCK();
 600         error = unp_connectat(fd, so, nam, td);
 601         UNP_LINK_WUNLOCK();
 602         return (error);
 603 }
 604
 605 static void
 606 uipc_close(struct socket *so)
 607 {
 608         struct unpcb *unp, *unp2;
 609         struct vnode *vp = NULL;
 610
 611         unp = sotounpcb(so);
 612         KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
 613
 614         UNP_LINK_WLOCK();
 615         UNP_PCB_LOCK(unp);
 616         unp2 = unp->unp_conn;
 617         if (unp2 != NULL) {
 618                 UNP_PCB_LOCK(unp2);
 619                 unp_disconnect(unp, unp2);
 620                 UNP_PCB_UNLOCK(unp2);
 621         }
 622         if (SOLISTENING(so) && ((vp = unp->unp_vnode) != NULL)) {
 623                 VOP_UNP_DETACH(vp);
 624                 unp->unp_vnode = NULL;
 625         }
 626         UNP_PCB_UNLOCK(unp);
 627         UNP_LINK_WUNLOCK();
 628         if (vp)
 629                 vrele(vp);
 630 }
 631
 632 static int
 633 uipc_connect2(struct socket *so1, struct socket *so2)
 634 {
 635         struct unpcb *unp, *unp2;
 636         int error;
 637
 638         UNP_LINK_WLOCK();
 639         unp = so1->so_pcb;
 640         KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
 641         UNP_PCB_LOCK(unp);
 642         unp2 = so2->so_pcb;
 643         KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
 644         UNP_PCB_LOCK(unp2);
 645         error = unp_connect2(so1, so2, PRU_CONNECT2);
 646         UNP_PCB_UNLOCK(unp2);
 647         UNP_PCB_UNLOCK(unp);
 648         UNP_LINK_WUNLOCK();
 649         return (error);
 650 }
 651
 652 static void
 653 uipc_detach(struct socket *so)
 654 {
 655         struct unpcb *unp, *unp2;
 656         struct sockaddr_un *saved_unp_addr;
 657         struct vnode *vp;
 658         int freeunp, local_unp_rights;
 659
 660         unp = sotounpcb(so);
 661         KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
 662
 663         vp = NULL;
 664         local_unp_rights = 0;
 665
 666         UNP_LINK_WLOCK();
 667         LIST_REMOVE(unp, unp_link);
 668         unp->unp_gencnt = ++unp_gencnt;
 669         --unp_count;
 670         UNP_PCB_LOCK(unp);
 671         if ((unp->unp_flags & UNP_NASCENT) != 0)
 672                 goto teardown;
 673
 674         if ((vp = unp->unp_vnode) != NULL) {
 675                 VOP_UNP_DETACH(vp);
 676                 unp->unp_vnode = NULL;
 677         }
 678         unp2 = unp->unp_conn;
 679         if (unp2 != NULL) {
 680                 UNP_PCB_LOCK(unp2);
 681                 unp_disconnect(unp, unp2);
 682                 UNP_PCB_UNLOCK(unp2);
 683         }
 684
 685         /*
 686          * We hold the linkage lock exclusively, so it's OK to acquire
 687          * multiple pcb locks at a time.
 688          */
 689         while (!LIST_EMPTY(&unp->unp_refs)) {
 690                 struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
 691
 692                 UNP_PCB_LOCK(ref);
 693                 unp_drop(ref);
 694                 UNP_PCB_UNLOCK(ref);
 695         }
 696         local_unp_rights = unp_rights;
 697 teardown:
 698         UNP_LINK_WUNLOCK();
 699         unp->unp_socket->so_pcb = NULL;
 700         saved_unp_addr = unp->unp_addr;
 701         unp->unp_addr = NULL;
 702         unp->unp_refcount--;
 703         freeunp = (unp->unp_refcount == 0);
 704         if (saved_unp_addr != NULL)
 705                 free(saved_unp_addr, M_SONAME);
 706         if (freeunp) {
 707                 UNP_PCB_LOCK_DESTROY(unp);
 708                 uma_zfree(unp_zone, unp);
 709         } else
 710                 UNP_PCB_UNLOCK(unp);
 711         if (vp)
 712                 vrele(vp);
 713         if (local_unp_rights)
 714                 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1);
 715 }
 716
 717 static int
 718 uipc_disconnect(struct socket *so)
 719 {
 720         struct unpcb *unp, *unp2;
 721
 722         unp = sotounpcb(so);
 723         KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
 724
 725         UNP_LINK_WLOCK();
 726         UNP_PCB_LOCK(unp);
 727         unp2 = unp->unp_conn;
 728         if (unp2 != NULL) {
 729                 UNP_PCB_LOCK(unp2);
 730                 unp_disconnect(unp, unp2);
 731                 UNP_PCB_UNLOCK(unp2);
 732         }
 733         UNP_PCB_UNLOCK(unp);
 734         UNP_LINK_WUNLOCK();
 735         return (0);
 736 }
 737
 738 static int
 739 uipc_listen(struct socket *so, int backlog, struct thread *td)
 740 {
 741         struct unpcb *unp;
 742         int error;
 743
 744         if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET)
 745                 return (EOPNOTSUPP);
 746
 747         unp = sotounpcb(so);
 748         KASSERT(unp != NULL, ("uipc_listen: unp == NULL"));
 749
 750         UNP_PCB_LOCK(unp);
 751         if (unp->unp_vnode == NULL) {
 752                 /* Already connected or not bound to an address. */
 753                 error = unp->unp_conn != NULL ? EINVAL : EDESTADDRREQ;
 754                 UNP_PCB_UNLOCK(unp);
 755                 return (error);
 756         }
 757
 758         SOCK_LOCK(so);
 759         error = solisten_proto_check(so);
 760         if (error == 0) {
 761                 cru2x(td->td_ucred, &unp->unp_peercred);
 762                 solisten_proto(so, backlog);
 763         }
 764         SOCK_UNLOCK(so);
 765         UNP_PCB_UNLOCK(unp);
 766         return (error);
 767 }
 768
 769 static int
 770 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
 771 {
 772         struct unpcb *unp, *unp2;
 773         const struct sockaddr *sa;
 774
 775         unp = sotounpcb(so);
 776         KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
 777
 778         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 779         UNP_LINK_RLOCK();
 780         /*
 781          * XXX: It seems that this test always fails even when connection is
 782          * established.  So, this else clause is added as workaround to
 783          * return PF_LOCAL sockaddr.
 784          */
 785         unp2 = unp->unp_conn;
 786         if (unp2 != NULL) {
 787                 UNP_PCB_LOCK(unp2);
 788                 if (unp2->unp_addr != NULL)
 789                         sa = (struct sockaddr *) unp2->unp_addr;
 790                 else
 791                         sa = &sun_noname;
 792                 bcopy(sa, *nam, sa->sa_len);
 793                 UNP_PCB_UNLOCK(unp2);
 794         } else {
 795                 sa = &sun_noname;
 796                 bcopy(sa, *nam, sa->sa_len);
 797         }
 798         UNP_LINK_RUNLOCK();
 799         return (0);
 800 }
 801
 802 static int
 803 uipc_rcvd(struct socket *so, int flags)
 804 {
 805         struct unpcb *unp, *unp2;
 806         struct socket *so2;
 807         u_int mbcnt, sbcc;
 808
 809         unp = sotounpcb(so);
 810         KASSERT(unp != NULL, ("%s: unp == NULL", __func__));
 811         KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET,
 812             ("%s: socktype %d", __func__, so->so_type));
 813
 814         /*
 815          * Adjust backpressure on sender and wakeup any waiting to write.
 816          *
 817          * The unp lock is acquired to maintain the validity of the unp_conn
 818          * pointer; no lock on unp2 is required as unp2->unp_socket will be
 819          * static as long as we don't permit unp2 to disconnect from unp,
 820          * which is prevented by the lock on unp.  We cache values from
 821          * so_rcv to avoid holding the so_rcv lock over the entire
 822          * transaction on the remote so_snd.
 823          */
 824         SOCKBUF_LOCK(&so->so_rcv);
 825         mbcnt = so->so_rcv.sb_mbcnt;
 826         sbcc = sbavail(&so->so_rcv);
 827         SOCKBUF_UNLOCK(&so->so_rcv);
 828         /*
 829          * There is a benign race condition at this point.  If we're planning to
 830          * clear SB_STOP, but uipc_send is called on the connected socket at
 831          * this instant, it might add data to the sockbuf and set SB_STOP.  Then
 832          * we would erroneously clear SB_STOP below, even though the sockbuf is
 833          * full.  The race is benign because the only ill effect is to allow the
 834          * sockbuf to exceed its size limit, and the size limits are not
 835          * strictly guaranteed anyway.
 836          */
 837         UNP_PCB_LOCK(unp);
 838         unp2 = unp->unp_conn;
 839         if (unp2 == NULL) {
 840                 UNP_PCB_UNLOCK(unp);
 841                 return (0);
 842         }
 843         so2 = unp2->unp_socket;
 844         SOCKBUF_LOCK(&so2->so_snd);
 845         if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax)
 846                 so2->so_snd.sb_flags &= ~SB_STOP;
 847         sowwakeup_locked(so2);
 848         UNP_PCB_UNLOCK(unp);
 849         return (0);
 850 }
 851
 852 static int
 853 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
 854     struct mbuf *control, struct thread *td)
 855 {
 856         struct unpcb *unp, *unp2;
 857         struct socket *so2;
 858         u_int mbcnt, sbcc;
 859         int error = 0;
 860
 861         unp = sotounpcb(so);
 862         KASSERT(unp != NULL, ("%s: unp == NULL", __func__));
 863         KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM ||
 864             so->so_type == SOCK_SEQPACKET,
 865             ("%s: socktype %d", __func__, so->so_type));
 866
 867         if (flags & PRUS_OOB) {
 868                 error = EOPNOTSUPP;
 869                 goto release;
 870         }
 871         if (control != NULL && (error = unp_internalize(&control, td)))
 872                 goto release;
 873         if ((nam != NULL) || (flags & PRUS_EOF))
 874                 UNP_LINK_WLOCK();
 875         else
 876                 UNP_LINK_RLOCK();
 877         switch (so->so_type) {
 878         case SOCK_DGRAM:
 879         {
 880                 const struct sockaddr *from;
 881
 882                 unp2 = unp->unp_conn;
 883                 if (nam != NULL) {
 884                         UNP_LINK_WLOCK_ASSERT();
 885                         if (unp2 != NULL) {
 886                                 error = EISCONN;
 887                                 break;
 888                         }
 889                         error = unp_connect(so, nam, td);
 890                         if (error)
 891                                 break;
 892                         unp2 = unp->unp_conn;
 893                 }
 894
 895                 /*
 896                  * Because connect() and send() are non-atomic in a sendto()
 897                  * with a target address, it's possible that the socket will
 898                  * have disconnected before the send() can run.  In that case
 899                  * return the slightly counter-intuitive but otherwise
 900                  * correct error that the socket is not connected.
 901                  */
 902                 if (unp2 == NULL) {
 903                         error = ENOTCONN;
 904                         break;
 905                 }
 906                 /* Lockless read. */
 907                 if (unp2->unp_flags & UNP_WANTCRED)
 908                         control = unp_addsockcred(td, control);
 909                 UNP_PCB_LOCK(unp);
 910                 if (unp->unp_addr != NULL)
 911                         from = (struct sockaddr *)unp->unp_addr;
 912                 else
 913                         from = &sun_noname;
 914                 so2 = unp2->unp_socket;
 915                 SOCKBUF_LOCK(&so2->so_rcv);
 916                 if (sbappendaddr_locked(&so2->so_rcv, from, m,
 917                     control)) {
 918                         sorwakeup_locked(so2);
 919                         m = NULL;
 920                         control = NULL;
 921                 } else {
 922                         SOCKBUF_UNLOCK(&so2->so_rcv);
 923                         error = ENOBUFS;
 924                 }
 925                 if (nam != NULL) {
 926                         UNP_LINK_WLOCK_ASSERT();
 927                         UNP_PCB_LOCK(unp2);
 928                         unp_disconnect(unp, unp2);
 929                         UNP_PCB_UNLOCK(unp2);
 930                 }
 931                 UNP_PCB_UNLOCK(unp);
 932                 break;
 933         }
 934
 935         case SOCK_SEQPACKET:
 936         case SOCK_STREAM:
 937                 if ((so->so_state & SS_ISCONNECTED) == 0) {
 938                         if (nam != NULL) {
 939                                 UNP_LINK_WLOCK_ASSERT();
 940                                 error = unp_connect(so, nam, td);
 941                                 if (error)
 942                                         break;  /* XXX */
 943                         } else {
 944                                 error = ENOTCONN;
 945                                 break;
 946                         }
 947                 }
 948
 949                 /* Lockless read. */
 950                 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
 951                         error = EPIPE;
 952                         break;
 953                 }
 954
 955                 /*
 956                  * Because connect() and send() are non-atomic in a sendto()
 957                  * with a target address, it's possible that the socket will
 958                  * have disconnected before the send() can run.  In that case
 959                  * return the slightly counter-intuitive but otherwise
 960                  * correct error that the socket is not connected.
 961                  *
 962                  * Locking here must be done carefully: the linkage lock
 963                  * prevents interconnections between unpcbs from changing, so
 964                  * we can traverse from unp to unp2 without acquiring unp's
 965                  * lock.  Socket buffer locks follow unpcb locks, so we can
 966                  * acquire both remote and lock socket buffer locks.
 967                  */
 968                 unp2 = unp->unp_conn;
 969                 if (unp2 == NULL) {
 970                         error = ENOTCONN;
 971                         break;
 972                 }
 973                 so2 = unp2->unp_socket;
 974                 UNP_PCB_LOCK(unp2);
 975                 SOCKBUF_LOCK(&so2->so_rcv);
 976                 if (unp2->unp_flags & UNP_WANTCRED) {
 977                         /*
 978                          * Credentials are passed only once on SOCK_STREAM
 979                          * and SOCK_SEQPACKET.
 980                          */
 981                         unp2->unp_flags &= ~UNP_WANTCRED;
 982                         control = unp_addsockcred(td, control);
 983                 }
 984                 /*
 985                  * Send to paired receive port, and then reduce send buffer
 986                  * hiwater marks to maintain backpressure.  Wake up readers.
 987                  */
 988                 switch (so->so_type) {
 989                 case SOCK_STREAM:
 990                         if (control != NULL) {
 991                                 if (sbappendcontrol_locked(&so2->so_rcv, m,
 992                                     control))
 993                                         control = NULL;
 994                         } else
 995                                 sbappend_locked(&so2->so_rcv, m, flags);
 996                         break;
 997
 998                 case SOCK_SEQPACKET: {
 999                         const struct sockaddr *from;
1000
1001                         from = &sun_noname;
1002                         /*
1003                          * Don't check for space available in so2->so_rcv.
1004                          * Unix domain sockets only check for space in the
1005                          * sending sockbuf, and that check is performed one
1006                          * level up the stack.
1007                          */
1008                         if (sbappendaddr_nospacecheck_locked(&so2->so_rcv,
1009                                 from, m, control))
1010                                 control = NULL;
1011                         break;
1012                         }
1013                 }
1014
1015                 mbcnt = so2->so_rcv.sb_mbcnt;
1016                 sbcc = sbavail(&so2->so_rcv);
1017                 if (sbcc)
1018                         sorwakeup_locked(so2);
1019                 else
1020                         SOCKBUF_UNLOCK(&so2->so_rcv);
1021
1022                 /*
1023                  * The PCB lock on unp2 protects the SB_STOP flag.  Without it,
1024                  * it would be possible for uipc_rcvd to be called at this
1025                  * point, drain the receiving sockbuf, clear SB_STOP, and then
1026                  * we would set SB_STOP below.  That could lead to an empty
1027                  * sockbuf having SB_STOP set
1028                  */
1029                 SOCKBUF_LOCK(&so->so_snd);
1030                 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax)
1031                         so->so_snd.sb_flags |= SB_STOP;
1032                 SOCKBUF_UNLOCK(&so->so_snd);
1033                 UNP_PCB_UNLOCK(unp2);
1034                 m = NULL;
1035                 break;
1036         }
1037
1038         /*
1039          * PRUS_EOF is equivalent to pru_send followed by pru_shutdown.
1040          */
1041         if (flags & PRUS_EOF) {
1042                 UNP_PCB_LOCK(unp);
1043                 socantsendmore(so);
1044                 unp_shutdown(unp);
1045                 UNP_PCB_UNLOCK(unp);
1046         }
1047
1048         if ((nam != NULL) || (flags & PRUS_EOF))
1049                 UNP_LINK_WUNLOCK();
1050         else
1051                 UNP_LINK_RUNLOCK();
1052
1053         if (control != NULL && error != 0)
1054                 unp_dispose_mbuf(control);
1055
1056 release:
1057         if (control != NULL)
1058                 m_freem(control);
1059         /*
1060          * In case of PRUS_NOTREADY, uipc_ready() is responsible
1061          * for freeing memory.
1062          */
1063         if (m != NULL && (flags & PRUS_NOTREADY) == 0)
1064                 m_freem(m);
1065         return (error);
1066 }
1067
1068 static int
1069 uipc_ready(struct socket *so, struct mbuf *m, int count)
1070 {
1071         struct unpcb *unp, *unp2;
1072         struct socket *so2;
1073         int error;
1074
1075         unp = sotounpcb(so);
1076
1077         UNP_LINK_RLOCK();
1078         if ((unp2 = unp->unp_conn) == NULL) {
1079                 UNP_LINK_RUNLOCK();
1080                 for (int i = 0; i < count; i++)
1081                         m = m_free(m);
1082                 return (ECONNRESET);
1083         }
1084         UNP_PCB_LOCK(unp2);
1085         so2 = unp2->unp_socket;
1086
1087         SOCKBUF_LOCK(&so2->so_rcv);
1088         if ((error = sbready(&so2->so_rcv, m, count)) == 0)
1089                 sorwakeup_locked(so2);
1090         else
1091                 SOCKBUF_UNLOCK(&so2->so_rcv);
1092
1093         UNP_PCB_UNLOCK(unp2);
1094         UNP_LINK_RUNLOCK();
1095
1096         return (error);
1097 }
1098
1099 static int
1100 uipc_sense(struct socket *so, struct stat *sb)
1101 {
1102         struct unpcb *unp;
1103
1104         unp = sotounpcb(so);
1105         KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
1106
1107         sb->st_blksize = so->so_snd.sb_hiwat;
1108         UNP_PCB_LOCK(unp);
1109         sb->st_dev = NODEV;
1110         if (unp->unp_ino == 0)
1111                 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
1112         sb->st_ino = unp->unp_ino;
1113         UNP_PCB_UNLOCK(unp);
1114         return (0);
1115 }
1116
1117 static int
1118 uipc_shutdown(struct socket *so)
1119 {
1120         struct unpcb *unp;
1121
1122         unp = sotounpcb(so);
1123         KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL"));
1124
1125         UNP_LINK_WLOCK();
1126         UNP_PCB_LOCK(unp);
1127         socantsendmore(so);
1128         unp_shutdown(unp);
1129         UNP_PCB_UNLOCK(unp);
1130         UNP_LINK_WUNLOCK();
1131         return (0);
1132 }
1133
1134 static int
1135 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
1136 {
1137         struct unpcb *unp;
1138         const struct sockaddr *sa;
1139
1140         unp = sotounpcb(so);
1141         KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
1142
1143         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1144         UNP_PCB_LOCK(unp);
1145         if (unp->unp_addr != NULL)
1146                 sa = (struct sockaddr *) unp->unp_addr;
1147         else
1148                 sa = &sun_noname;
1149         bcopy(sa, *nam, sa->sa_len);
1150         UNP_PCB_UNLOCK(unp);
1151         return (0);
1152 }
1153
1154 static struct pr_usrreqs uipc_usrreqs_dgram = {
1155         .pru_abort =            uipc_abort,
1156         .pru_accept =           uipc_accept,
1157         .pru_attach =           uipc_attach,
1158         .pru_bind =             uipc_bind,
1159         .pru_bindat =           uipc_bindat,
1160         .pru_connect =          uipc_connect,
1161         .pru_connectat =        uipc_connectat,
1162         .pru_connect2 =         uipc_connect2,
1163         .pru_detach =           uipc_detach,
1164         .pru_disconnect =       uipc_disconnect,
1165         .pru_listen =           uipc_listen,
1166         .pru_peeraddr =         uipc_peeraddr,
1167         .pru_rcvd =             uipc_rcvd,
1168         .pru_send =             uipc_send,
1169         .pru_sense =            uipc_sense,
1170         .pru_shutdown =         uipc_shutdown,
1171         .pru_sockaddr =         uipc_sockaddr,
1172         .pru_soreceive =        soreceive_dgram,
1173         .pru_close =            uipc_close,
1174 };
1175
1176 static struct pr_usrreqs uipc_usrreqs_seqpacket = {
1177         .pru_abort =            uipc_abort,
1178         .pru_accept =           uipc_accept,
1179         .pru_attach =           uipc_attach,
1180         .pru_bind =             uipc_bind,
1181         .pru_bindat =           uipc_bindat,
1182         .pru_connect =          uipc_connect,
1183         .pru_connectat =        uipc_connectat,
1184         .pru_connect2 =         uipc_connect2,
1185         .pru_detach =           uipc_detach,
1186         .pru_disconnect =       uipc_disconnect,
1187         .pru_listen =           uipc_listen,
1188         .pru_peeraddr =         uipc_peeraddr,
1189         .pru_rcvd =             uipc_rcvd,
1190         .pru_send =             uipc_send,
1191         .pru_sense =            uipc_sense,
1192         .pru_shutdown =         uipc_shutdown,
1193         .pru_sockaddr =         uipc_sockaddr,
1194         .pru_soreceive =        soreceive_generic,      /* XXX: or...? */
1195         .pru_close =            uipc_close,
1196 };
1197
1198 static struct pr_usrreqs uipc_usrreqs_stream = {
1199         .pru_abort =            uipc_abort,
1200         .pru_accept =           uipc_accept,
1201         .pru_attach =           uipc_attach,
1202         .pru_bind =             uipc_bind,
1203         .pru_bindat =           uipc_bindat,
1204         .pru_connect =          uipc_connect,
1205         .pru_connectat =        uipc_connectat,
1206         .pru_connect2 =         uipc_connect2,
1207         .pru_detach =           uipc_detach,
1208         .pru_disconnect =       uipc_disconnect,
1209         .pru_listen =           uipc_listen,
1210         .pru_peeraddr =         uipc_peeraddr,
1211         .pru_rcvd =             uipc_rcvd,
1212         .pru_send =             uipc_send,
1213         .pru_ready =            uipc_ready,
1214         .pru_sense =            uipc_sense,
1215         .pru_shutdown =         uipc_shutdown,
1216         .pru_sockaddr =         uipc_sockaddr,
1217         .pru_soreceive =        soreceive_generic,
1218         .pru_close =            uipc_close,
1219 };
1220
1221 static int
1222 uipc_ctloutput(struct socket *so, struct sockopt *sopt)
1223 {
1224         struct unpcb *unp;
1225         struct xucred xu;
1226         int error, optval;
1227
1228         if (sopt->sopt_level != 0)
1229                 return (EINVAL);
1230
1231         unp = sotounpcb(so);
1232         KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
1233         error = 0;
1234         switch (sopt->sopt_dir) {
1235         case SOPT_GET:
1236                 switch (sopt->sopt_name) {
1237                 case LOCAL_PEERCRED:
1238                         UNP_PCB_LOCK(unp);
1239                         if (unp->unp_flags & UNP_HAVEPC)
1240                                 xu = unp->unp_peercred;
1241                         else {
1242                                 if (so->so_type == SOCK_STREAM)
1243                                         error = ENOTCONN;
1244                                 else
1245                                         error = EINVAL;
1246                         }
1247                         UNP_PCB_UNLOCK(unp);
1248                         if (error == 0)
1249                                 error = sooptcopyout(sopt, &xu, sizeof(xu));
1250                         break;
1251
1252                 case LOCAL_CREDS:
1253                         /* Unlocked read. */
1254                         optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0;
1255                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1256                         break;
1257
1258                 case LOCAL_CONNWAIT:
1259                         /* Unlocked read. */
1260                         optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0;
1261                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1262                         break;
1263
1264                 default:
1265                         error = EOPNOTSUPP;
1266                         break;
1267                 }
1268                 break;
1269
1270         case SOPT_SET:
1271                 switch (sopt->sopt_name) {
1272                 case LOCAL_CREDS:
1273                 case LOCAL_CONNWAIT:
1274                         error = sooptcopyin(sopt, &optval, sizeof(optval),
1275                                             sizeof(optval));
1276                         if (error)
1277                                 break;
1278
1279 #define OPTSET(bit) do {                                                \
1280         UNP_PCB_LOCK(unp);                                              \
1281         if (optval)                                                     \
1282                 unp->unp_flags |= bit;                                  \
1283         else                                                            \
1284                 unp->unp_flags &= ~bit;                                 \
1285         UNP_PCB_UNLOCK(unp);                                            \
1286 } while (0)
1287
1288                         switch (sopt->sopt_name) {
1289                         case LOCAL_CREDS:
1290                                 OPTSET(UNP_WANTCRED);
1291                                 break;
1292
1293                         case LOCAL_CONNWAIT:
1294                                 OPTSET(UNP_CONNWAIT);
1295                                 break;
1296
1297                         default:
1298                                 break;
1299                         }
1300                         break;
1301 #undef  OPTSET
1302                 default:
1303                         error = ENOPROTOOPT;
1304                         break;
1305                 }
1306                 break;
1307
1308         default:
1309                 error = EOPNOTSUPP;
1310                 break;
1311         }
1312         return (error);
1313 }
1314
1315 static int
1316 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1317 {
1318
1319         return (unp_connectat(AT_FDCWD, so, nam, td));
1320 }
1321
1322 static int
1323 unp_connectat(int fd, struct socket *so, struct sockaddr *nam,
1324     struct thread *td)
1325 {
1326         struct sockaddr_un *soun = (struct sockaddr_un *)nam;
1327         struct vnode *vp;
1328         struct socket *so2;
1329         struct unpcb *unp, *unp2, *unp3;
1330         struct nameidata nd;
1331         char buf[SOCK_MAXADDRLEN];
1332         struct sockaddr *sa;
1333         cap_rights_t rights;
1334         int error, len;
1335
1336         if (nam->sa_family != AF_UNIX)
1337                 return (EAFNOSUPPORT);
1338
1339         UNP_LINK_WLOCK_ASSERT();
1340
1341         unp = sotounpcb(so);
1342         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1343
1344         if (nam->sa_len > sizeof(struct sockaddr_un))
1345                 return (EINVAL);
1346         len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
1347         if (len <= 0)
1348                 return (EINVAL);
1349         bcopy(soun->sun_path, buf, len);
1350         buf[len] = 0;
1351
1352         UNP_PCB_LOCK(unp);
1353         if (unp->unp_flags & UNP_CONNECTING) {
1354                 UNP_PCB_UNLOCK(unp);
1355                 return (EALREADY);
1356         }
1357         UNP_LINK_WUNLOCK();
1358         unp->unp_flags |= UNP_CONNECTING;
1359         UNP_PCB_UNLOCK(unp);
1360
1361         sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1362         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
1363             UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td);
1364         error = namei(&nd);
1365         if (error)
1366                 vp = NULL;
1367         else
1368                 vp = nd.ni_vp;
1369         ASSERT_VOP_LOCKED(vp, "unp_connect");
1370         NDFREE(&nd, NDF_ONLY_PNBUF);
1371         if (error)
1372                 goto bad;
1373
1374         if (vp->v_type != VSOCK) {
1375                 error = ENOTSOCK;
1376                 goto bad;
1377         }
1378 #ifdef MAC
1379         error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
1380         if (error)
1381                 goto bad;
1382 #endif
1383         error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
1384         if (error)
1385                 goto bad;
1386
1387         unp = sotounpcb(so);
1388         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1389
1390         /*
1391          * Lock linkage lock for two reasons: make sure v_socket is stable,
1392          * and to protect simultaneous locking of multiple pcbs.
1393          */
1394         UNP_LINK_WLOCK();
1395         VOP_UNP_CONNECT(vp, &unp2);
1396         if (unp2 == NULL) {
1397                 error = ECONNREFUSED;
1398                 goto bad2;
1399         }
1400         so2 = unp2->unp_socket;
1401         if (so->so_type != so2->so_type) {
1402                 error = EPROTOTYPE;
1403                 goto bad2;
1404         }
1405         UNP_PCB_LOCK(unp);
1406         UNP_PCB_LOCK(unp2);
1407         if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
1408                 if (so2->so_options & SO_ACCEPTCONN) {
1409                         CURVNET_SET(so2->so_vnet);
1410                         so2 = sonewconn(so2, 0);
1411                         CURVNET_RESTORE();
1412                 } else
1413                         so2 = NULL;
1414                 if (so2 == NULL) {
1415                         error = ECONNREFUSED;
1416                         goto bad3;
1417                 }
1418                 unp3 = sotounpcb(so2);
1419                 UNP_PCB_LOCK(unp3);
1420                 if (unp2->unp_addr != NULL) {
1421                         bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
1422                         unp3->unp_addr = (struct sockaddr_un *) sa;
1423                         sa = NULL;
1424                 }
1425
1426                 /*
1427                  * The connector's (client's) credentials are copied from its
1428                  * process structure at the time of connect() (which is now).
1429                  */
1430                 cru2x(td->td_ucred, &unp3->unp_peercred);
1431                 unp3->unp_flags |= UNP_HAVEPC;
1432
1433                 /*
1434                  * The receiver's (server's) credentials are copied from the
1435                  * unp_peercred member of socket on which the former called
1436                  * listen(); uipc_listen() cached that process's credentials
1437                  * at that time so we can use them now.
1438                  */
1439                 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
1440                     sizeof(unp->unp_peercred));
1441                 unp->unp_flags |= UNP_HAVEPC;
1442                 if (unp2->unp_flags & UNP_WANTCRED)
1443                         unp3->unp_flags |= UNP_WANTCRED;
1444                 UNP_PCB_UNLOCK(unp2);
1445                 unp2 = unp3;
1446 #ifdef MAC
1447                 mac_socketpeer_set_from_socket(so, so2);
1448                 mac_socketpeer_set_from_socket(so2, so);
1449 #endif
1450         }
1451
1452         KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 &&
1453             sotounpcb(so2) == unp2,
1454             ("%s: unp2 %p so2 %p", __func__, unp2, so2));
1455         error = unp_connect2(so, so2, PRU_CONNECT);
1456 bad3:
1457         UNP_PCB_UNLOCK(unp2);
1458         UNP_PCB_UNLOCK(unp);
1459 bad2:
1460         UNP_LINK_WUNLOCK();
1461 bad:
1462         if (vp != NULL)
1463                 vput(vp);
1464         free(sa, M_SONAME);
1465         UNP_LINK_WLOCK();
1466         UNP_PCB_LOCK(unp);
1467         unp->unp_flags &= ~UNP_CONNECTING;
1468         UNP_PCB_UNLOCK(unp);
1469         return (error);
1470 }
1471
1472 static int
1473 unp_connect2(struct socket *so, struct socket *so2, int req)
1474 {
1475         struct unpcb *unp;
1476         struct unpcb *unp2;
1477
1478         unp = sotounpcb(so);
1479         KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
1480         unp2 = sotounpcb(so2);
1481         KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
1482
1483         UNP_LINK_WLOCK_ASSERT();
1484         UNP_PCB_LOCK_ASSERT(unp);
1485         UNP_PCB_LOCK_ASSERT(unp2);
1486
1487         if (so2->so_type != so->so_type)
1488                 return (EPROTOTYPE);
1489         unp2->unp_flags &= ~UNP_NASCENT;
1490         unp->unp_conn = unp2;
1491
1492         switch (so->so_type) {
1493         case SOCK_DGRAM:
1494                 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
1495                 soisconnected(so);
1496                 break;
1497
1498         case SOCK_STREAM:
1499         case SOCK_SEQPACKET:
1500                 unp2->unp_conn = unp;
1501                 if (req == PRU_CONNECT &&
1502                     ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
1503                         soisconnecting(so);
1504                 else
1505                         soisconnected(so);
1506                 soisconnected(so2);
1507                 break;
1508
1509         default:
1510                 panic("unp_connect2");
1511         }
1512         return (0);
1513 }
1514
1515 static void
1516 unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
1517 {
1518         struct socket *so;
1519
1520         KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL"));
1521
1522         UNP_LINK_WLOCK_ASSERT();
1523         UNP_PCB_LOCK_ASSERT(unp);
1524         UNP_PCB_LOCK_ASSERT(unp2);
1525
1526         unp->unp_conn = NULL;
1527         switch (unp->unp_socket->so_type) {
1528         case SOCK_DGRAM:
1529                 LIST_REMOVE(unp, unp_reflink);
1530                 so = unp->unp_socket;
1531                 SOCK_LOCK(so);
1532                 so->so_state &= ~SS_ISCONNECTED;
1533                 SOCK_UNLOCK(so);
1534                 break;
1535
1536         case SOCK_STREAM:
1537         case SOCK_SEQPACKET:
1538                 soisdisconnected(unp->unp_socket);
1539                 unp2->unp_conn = NULL;
1540                 soisdisconnected(unp2->unp_socket);
1541                 break;
1542         }
1543 }
1544
1545 /*
1546  * unp_pcblist() walks the global list of struct unpcb's to generate a
1547  * pointer list, bumping the refcount on each unpcb.  It then copies them out
1548  * sequentially, validating the generation number on each to see if it has
1549  * been detached.  All of this is necessary because copyout() may sleep on
1550  * disk I/O.
1551  */
1552 static int
1553 unp_pcblist(SYSCTL_HANDLER_ARGS)
1554 {
1555         int error, i, n;
1556         int freeunp;
1557         struct unpcb *unp, **unp_list;
1558         unp_gen_t gencnt;
1559         struct xunpgen *xug;
1560         struct unp_head *head;
1561         struct xunpcb *xu;
1562
1563         switch ((intptr_t)arg1) {
1564         case SOCK_STREAM:
1565                 head = &unp_shead;
1566                 break;
1567
1568         case SOCK_DGRAM:
1569                 head = &unp_dhead;
1570                 break;
1571
1572         case SOCK_SEQPACKET:
1573                 head = &unp_sphead;
1574                 break;
1575
1576         default:
1577                 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1);
1578         }
1579
1580         /*
1581          * The process of preparing the PCB list is too time-consuming and
1582          * resource-intensive to repeat twice on every request.
1583          */
1584         if (req->oldptr == NULL) {
1585                 n = unp_count;
1586                 req->oldidx = 2 * (sizeof *xug)
1587                         + (n + n/8) * sizeof(struct xunpcb);
1588                 return (0);
1589         }
1590
1591         if (req->newptr != NULL)
1592                 return (EPERM);
1593
1594         /*
1595          * OK, now we're committed to doing something.
1596          */
1597         xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK);
1598         UNP_LINK_RLOCK();
1599         gencnt = unp_gencnt;
1600         n = unp_count;
1601         UNP_LINK_RUNLOCK();
1602
1603         xug->xug_len = sizeof *xug;
1604         xug->xug_count = n;
1605         xug->xug_gen = gencnt;
1606         xug->xug_sogen = so_gencnt;
1607         error = SYSCTL_OUT(req, xug, sizeof *xug);
1608         if (error) {
1609                 free(xug, M_TEMP);
1610                 return (error);
1611         }
1612
1613         unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
1614
1615         UNP_LINK_RLOCK();
1616         for (unp = LIST_FIRST(head), i = 0; unp && i < n;
1617              unp = LIST_NEXT(unp, unp_link)) {
1618                 UNP_PCB_LOCK(unp);
1619                 if (unp->unp_gencnt <= gencnt) {
1620                         if (cr_cansee(req->td->td_ucred,
1621                             unp->unp_socket->so_cred)) {
1622                                 UNP_PCB_UNLOCK(unp);
1623                                 continue;
1624                         }
1625                         unp_list[i++] = unp;
1626                         unp->unp_refcount++;
1627                 }
1628                 UNP_PCB_UNLOCK(unp);
1629         }
1630         UNP_LINK_RUNLOCK();
1631         n = i;                  /* In case we lost some during malloc. */
1632
1633         error = 0;
1634         xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
1635         for (i = 0; i < n; i++) {
1636                 unp = unp_list[i];
1637                 UNP_PCB_LOCK(unp);
1638                 unp->unp_refcount--;
1639                 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) {
1640                         xu->xu_len = sizeof *xu;
1641                         xu->xu_unpp = unp;
1642                         /*
1643                          * XXX - need more locking here to protect against
1644                          * connect/disconnect races for SMP.
1645                          */
1646                         if (unp->unp_addr != NULL)
1647                                 bcopy(unp->unp_addr, &xu->xu_addr,
1648                                       unp->unp_addr->sun_len);
1649                         if (unp->unp_conn != NULL &&
1650                             unp->unp_conn->unp_addr != NULL)
1651                                 bcopy(unp->unp_conn->unp_addr,
1652                                       &xu->xu_caddr,
1653                                       unp->unp_conn->unp_addr->sun_len);
1654                         bcopy(unp, &xu->xu_unp, sizeof *unp);
1655                         sotoxsocket(unp->unp_socket, &xu->xu_socket);
1656                         UNP_PCB_UNLOCK(unp);
1657                         error = SYSCTL_OUT(req, xu, sizeof *xu);
1658                 } else {
1659                         freeunp = (unp->unp_refcount == 0);
1660                         UNP_PCB_UNLOCK(unp);
1661                         if (freeunp) {
1662                                 UNP_PCB_LOCK_DESTROY(unp);
1663                                 uma_zfree(unp_zone, unp);
1664                         }
1665                 }
1666         }
1667         free(xu, M_TEMP);
1668         if (!error) {
1669                 /*
1670                  * Give the user an updated idea of our state.  If the
1671                  * generation differs from what we told her before, she knows
1672                  * that something happened while we were processing this
1673                  * request, and it might be necessary to retry.
1674                  */
1675                 xug->xug_gen = unp_gencnt;
1676                 xug->xug_sogen = so_gencnt;
1677                 xug->xug_count = unp_count;
1678                 error = SYSCTL_OUT(req, xug, sizeof *xug);
1679         }
1680         free(unp_list, M_TEMP);
1681         free(xug, M_TEMP);
1682         return (error);
1683 }
1684
1685 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
1686     (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
1687     "List of active local datagram sockets");
1688 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
1689     (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
1690     "List of active local stream sockets");
1691 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist,
1692     CTLTYPE_OPAQUE | CTLFLAG_RD,
1693     (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb",
1694     "List of active local seqpacket sockets");
1695
1696 static void
1697 unp_shutdown(struct unpcb *unp)
1698 {
1699         struct unpcb *unp2;
1700         struct socket *so;
1701
1702         UNP_LINK_WLOCK_ASSERT();
1703         UNP_PCB_LOCK_ASSERT(unp);
1704
1705         unp2 = unp->unp_conn;
1706         if ((unp->unp_socket->so_type == SOCK_STREAM ||
1707             (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) {
1708                 so = unp2->unp_socket;
1709                 if (so != NULL)
1710                         socantrcvmore(so);
1711         }
1712 }
1713
1714 static void
1715 unp_drop(struct unpcb *unp)
1716 {
1717         struct socket *so = unp->unp_socket;
1718         struct unpcb *unp2;
1719
1720         UNP_LINK_WLOCK_ASSERT();
1721         UNP_PCB_LOCK_ASSERT(unp);
1722
1723         /*
1724          * Regardless of whether the socket's peer dropped the connection
1725          * with this socket by aborting or disconnecting, POSIX requires
1726          * that ECONNRESET is returned.
1727          */
1728         so->so_error = ECONNRESET;
1729         unp2 = unp->unp_conn;
1730         if (unp2 == NULL)
1731                 return;
1732         UNP_PCB_LOCK(unp2);
1733         unp_disconnect(unp, unp2);
1734         UNP_PCB_UNLOCK(unp2);
1735 }
1736
1737 static void
1738 unp_freerights(struct filedescent **fdep, int fdcount)
1739 {
1740         struct file *fp;
1741         int i;
1742
1743         KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount));
1744
1745         for (i = 0; i < fdcount; i++) {
1746                 fp = fdep[i]->fde_file;
1747                 filecaps_free(&fdep[i]->fde_caps);
1748                 unp_discard(fp);
1749         }
1750         free(fdep[0], M_FILECAPS);
1751 }
1752
1753 static int
1754 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
1755 {
1756         struct thread *td = curthread;          /* XXX */
1757         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1758         int i;
1759         int *fdp;
1760         struct filedesc *fdesc = td->td_proc->p_fd;
1761         struct filedescent **fdep;
1762         void *data;
1763         socklen_t clen = control->m_len, datalen;
1764         int error, newfds;
1765         u_int newlen;
1766
1767         UNP_LINK_UNLOCK_ASSERT();
1768
1769         error = 0;
1770         if (controlp != NULL) /* controlp == NULL => free control messages */
1771                 *controlp = NULL;
1772         while (cm != NULL) {
1773                 if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
1774                         error = EINVAL;
1775                         break;
1776                 }
1777                 data = CMSG_DATA(cm);
1778                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1779                 if (cm->cmsg_level == SOL_SOCKET
1780                     && cm->cmsg_type == SCM_RIGHTS) {
1781                         newfds = datalen / sizeof(*fdep);
1782                         if (newfds == 0)
1783                                 goto next;
1784                         fdep = data;
1785
1786                         /* If we're not outputting the descriptors free them. */
1787                         if (error || controlp == NULL) {
1788                                 unp_freerights(fdep, newfds);
1789                                 goto next;
1790                         }
1791                         FILEDESC_XLOCK(fdesc);
1792
1793                         /*
1794                          * Now change each pointer to an fd in the global
1795                          * table to an integer that is the index to the local
1796                          * fd table entry that we set up to point to the
1797                          * global one we are transferring.
1798                          */
1799                         newlen = newfds * sizeof(int);
1800                         *controlp = sbcreatecontrol(NULL, newlen,
1801                             SCM_RIGHTS, SOL_SOCKET);
1802                         if (*controlp == NULL) {
1803                                 FILEDESC_XUNLOCK(fdesc);
1804                                 error = E2BIG;
1805                                 unp_freerights(fdep, newfds);
1806                                 goto next;
1807                         }
1808
1809                         fdp = (int *)
1810                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1811                         if (fdallocn(td, 0, fdp, newfds) != 0) {
1812                                 FILEDESC_XUNLOCK(fdesc);
1813                                 error = EMSGSIZE;
1814                                 unp_freerights(fdep, newfds);
1815                                 m_freem(*controlp);
1816                                 *controlp = NULL;
1817                                 goto next;
1818                         }
1819                         for (i = 0; i < newfds; i++, fdp++) {
1820                                 _finstall(fdesc, fdep[i]->fde_file, *fdp,
1821                                     (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0,
1822                                     &fdep[i]->fde_caps);
1823                                 unp_externalize_fp(fdep[i]->fde_file);
1824                         }
1825                         FILEDESC_XUNLOCK(fdesc);
1826                         free(fdep[0], M_FILECAPS);
1827                 } else {
1828                         /* We can just copy anything else across. */
1829                         if (error || controlp == NULL)
1830                                 goto next;
1831                         *controlp = sbcreatecontrol(NULL, datalen,
1832                             cm->cmsg_type, cm->cmsg_level);
1833                         if (*controlp == NULL) {
1834                                 error = ENOBUFS;
1835                                 goto next;
1836                         }
1837                         bcopy(data,
1838                             CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
1839                             datalen);
1840                 }
1841                 controlp = &(*controlp)->m_next;
1842
1843 next:
1844                 if (CMSG_SPACE(datalen) < clen) {
1845                         clen -= CMSG_SPACE(datalen);
1846                         cm = (struct cmsghdr *)
1847                             ((caddr_t)cm + CMSG_SPACE(datalen));
1848                 } else {
1849                         clen = 0;
1850                         cm = NULL;
1851                 }
1852         }
1853
1854         m_freem(control);
1855         return (error);
1856 }
1857
1858 static void
1859 unp_zone_change(void *tag)
1860 {
1861
1862         uma_zone_set_max(unp_zone, maxsockets);
1863 }
1864
1865 static void
1866 unp_init(void)
1867 {
1868
1869 #ifdef VIMAGE
1870         if (!IS_DEFAULT_VNET(curvnet))
1871                 return;
1872 #endif
1873         unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL,
1874             NULL, NULL, UMA_ALIGN_PTR, 0);
1875         if (unp_zone == NULL)
1876                 panic("unp_init");
1877         uma_zone_set_max(unp_zone, maxsockets);
1878         uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached");
1879         EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
1880             NULL, EVENTHANDLER_PRI_ANY);
1881         LIST_INIT(&unp_dhead);
1882         LIST_INIT(&unp_shead);
1883         LIST_INIT(&unp_sphead);
1884         SLIST_INIT(&unp_defers);
1885         TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL);
1886         TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL);
1887         UNP_LINK_LOCK_INIT();
1888         UNP_DEFERRED_LOCK_INIT();
1889 }
1890
1891 static int
1892 unp_internalize(struct mbuf **controlp, struct thread *td)
1893 {
1894         struct mbuf *control = *controlp;
1895         struct proc *p = td->td_proc;
1896         struct filedesc *fdesc = p->p_fd;
1897         struct bintime *bt;
1898         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1899         struct cmsgcred *cmcred;
1900         struct filedescent *fde, **fdep, *fdev;
1901         struct file *fp;
1902         struct timeval *tv;
1903         struct timespec *ts;
1904         int i, *fdp;
1905         void *data;
1906         socklen_t clen = control->m_len, datalen;
1907         int error, oldfds;
1908         u_int newlen;
1909
1910         UNP_LINK_UNLOCK_ASSERT();
1911
1912         error = 0;
1913         *controlp = NULL;
1914         while (cm != NULL) {
1915                 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET
1916                     || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) {
1917                         error = EINVAL;
1918                         goto out;
1919                 }
1920                 data = CMSG_DATA(cm);
1921                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1922
1923                 switch (cm->cmsg_type) {
1924                 /*
1925                  * Fill in credential information.
1926                  */
1927                 case SCM_CREDS:
1928                         *controlp = sbcreatecontrol(NULL, sizeof(*cmcred),
1929                             SCM_CREDS, SOL_SOCKET);
1930                         if (*controlp == NULL) {
1931                                 error = ENOBUFS;
1932                                 goto out;
1933                         }
1934                         cmcred = (struct cmsgcred *)
1935                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1936                         cmcred->cmcred_pid = p->p_pid;
1937                         cmcred->cmcred_uid = td->td_ucred->cr_ruid;
1938                         cmcred->cmcred_gid = td->td_ucred->cr_rgid;
1939                         cmcred->cmcred_euid = td->td_ucred->cr_uid;
1940                         cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups,
1941                             CMGROUP_MAX);
1942                         for (i = 0; i < cmcred->cmcred_ngroups; i++)
1943                                 cmcred->cmcred_groups[i] =
1944                                     td->td_ucred->cr_groups[i];
1945                         break;
1946
1947                 case SCM_RIGHTS:
1948                         oldfds = datalen / sizeof (int);
1949                         if (oldfds == 0)
1950                                 break;
1951                         /*
1952                          * Check that all the FDs passed in refer to legal
1953                          * files.  If not, reject the entire operation.
1954                          */
1955                         fdp = data;
1956                         FILEDESC_SLOCK(fdesc);
1957                         for (i = 0; i < oldfds; i++, fdp++) {
1958                                 fp = fget_locked(fdesc, *fdp);
1959                                 if (fp == NULL) {
1960                                         FILEDESC_SUNLOCK(fdesc);
1961                                         error = EBADF;
1962                                         goto out;
1963                                 }
1964                                 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
1965                                         FILEDESC_SUNLOCK(fdesc);
1966                                         error = EOPNOTSUPP;
1967                                         goto out;
1968                                 }
1969
1970                         }
1971
1972                         /*
1973                          * Now replace the integer FDs with pointers to the
1974                          * file structure and capability rights.
1975                          */
1976                         newlen = oldfds * sizeof(fdep[0]);
1977                         *controlp = sbcreatecontrol(NULL, newlen,
1978                             SCM_RIGHTS, SOL_SOCKET);
1979                         if (*controlp == NULL) {
1980                                 FILEDESC_SUNLOCK(fdesc);
1981                                 error = E2BIG;
1982                                 goto out;
1983                         }
1984                         fdp = data;
1985                         fdep = (struct filedescent **)
1986                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1987                         fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS,
1988                             M_WAITOK);
1989                         for (i = 0; i < oldfds; i++, fdev++, fdp++) {
1990                                 fde = &fdesc->fd_ofiles[*fdp];
1991                                 fdep[i] = fdev;
1992                                 fdep[i]->fde_file = fde->fde_file;
1993                                 filecaps_copy(&fde->fde_caps,
1994                                     &fdep[i]->fde_caps, true);
1995                                 unp_internalize_fp(fdep[i]->fde_file);
1996                         }
1997                         FILEDESC_SUNLOCK(fdesc);
1998                         break;
1999
2000                 case SCM_TIMESTAMP:
2001                         *controlp = sbcreatecontrol(NULL, sizeof(*tv),
2002                             SCM_TIMESTAMP, SOL_SOCKET);
2003                         if (*controlp == NULL) {
2004                                 error = ENOBUFS;
2005                                 goto out;
2006                         }
2007                         tv = (struct timeval *)
2008                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
2009                         microtime(tv);
2010                         break;
2011
2012                 case SCM_BINTIME:
2013                         *controlp = sbcreatecontrol(NULL, sizeof(*bt),
2014                             SCM_BINTIME, SOL_SOCKET);
2015                         if (*controlp == NULL) {
2016                                 error = ENOBUFS;
2017                                 goto out;
2018                         }
2019                         bt = (struct bintime *)
2020                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
2021                         bintime(bt);
2022                         break;
2023
2024                 case SCM_REALTIME:
2025                         *controlp = sbcreatecontrol(NULL, sizeof(*ts),
2026                             SCM_REALTIME, SOL_SOCKET);
2027                         if (*controlp == NULL) {
2028                                 error = ENOBUFS;
2029                                 goto out;
2030                         }
2031                         ts = (struct timespec *)
2032                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
2033                         nanotime(ts);
2034                         break;
2035
2036                 case SCM_MONOTONIC:
2037                         *controlp = sbcreatecontrol(NULL, sizeof(*ts),
2038                             SCM_MONOTONIC, SOL_SOCKET);
2039                         if (*controlp == NULL) {
2040                                 error = ENOBUFS;
2041                                 goto out;
2042                         }
2043                         ts = (struct timespec *)
2044                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
2045                         nanouptime(ts);
2046                         break;
2047
2048                 default:
2049                         error = EINVAL;
2050                         goto out;
2051                 }
2052
2053                 controlp = &(*controlp)->m_next;
2054                 if (CMSG_SPACE(datalen) < clen) {
2055                         clen -= CMSG_SPACE(datalen);
2056                         cm = (struct cmsghdr *)
2057                             ((caddr_t)cm + CMSG_SPACE(datalen));
2058                 } else {
2059                         clen = 0;
2060                         cm = NULL;
2061                 }
2062         }
2063
2064 out:
2065         m_freem(control);
2066         return (error);
2067 }
2068
2069 static struct mbuf *
2070 unp_addsockcred(struct thread *td, struct mbuf *control)
2071 {
2072         struct mbuf *m, *n, *n_prev;
2073         struct sockcred *sc;
2074         const struct cmsghdr *cm;
2075         int ngroups;
2076         int i;
2077
2078         ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
2079         m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET);
2080         if (m == NULL)
2081                 return (control);
2082
2083         sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *));
2084         sc->sc_uid = td->td_ucred->cr_ruid;
2085         sc->sc_euid = td->td_ucred->cr_uid;
2086         sc->sc_gid = td->td_ucred->cr_rgid;
2087         sc->sc_egid = td->td_ucred->cr_gid;
2088         sc->sc_ngroups = ngroups;
2089         for (i = 0; i < sc->sc_ngroups; i++)
2090                 sc->sc_groups[i] = td->td_ucred->cr_groups[i];
2091
2092         /*
2093          * Unlink SCM_CREDS control messages (struct cmsgcred), since just
2094          * created SCM_CREDS control message (struct sockcred) has another
2095          * format.
2096          */
2097         if (control != NULL)
2098                 for (n = control, n_prev = NULL; n != NULL;) {
2099                         cm = mtod(n, struct cmsghdr *);
2100                         if (cm->cmsg_level == SOL_SOCKET &&
2101                             cm->cmsg_type == SCM_CREDS) {
2102                                 if (n_prev == NULL)
2103                                         control = n->m_next;
2104                                 else
2105                                         n_prev->m_next = n->m_next;
2106                                 n = m_free(n);
2107                         } else {
2108                                 n_prev = n;
2109                                 n = n->m_next;
2110                         }
2111                 }
2112
2113         /* Prepend it to the head. */
2114         m->m_next = control;
2115         return (m);
2116 }
2117
2118 static struct unpcb *
2119 fptounp(struct file *fp)
2120 {
2121         struct socket *so;
2122
2123         if (fp->f_type != DTYPE_SOCKET)
2124                 return (NULL);
2125         if ((so = fp->f_data) == NULL)
2126                 return (NULL);
2127         if (so->so_proto->pr_domain != &localdomain)
2128                 return (NULL);
2129         return sotounpcb(so);
2130 }
2131
2132 static void
2133 unp_discard(struct file *fp)
2134 {
2135         struct unp_defer *dr;
2136
2137         if (unp_externalize_fp(fp)) {
2138                 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK);
2139                 dr->ud_fp = fp;
2140                 UNP_DEFERRED_LOCK();
2141                 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link);
2142                 UNP_DEFERRED_UNLOCK();
2143                 atomic_add_int(&unp_defers_count, 1);
2144                 taskqueue_enqueue(taskqueue_thread, &unp_defer_task);
2145         } else
2146                 (void) closef(fp, (struct thread *)NULL);
2147 }
2148
2149 static void
2150 unp_process_defers(void *arg __unused, int pending)
2151 {
2152         struct unp_defer *dr;
2153         SLIST_HEAD(, unp_defer) drl;
2154         int count;
2155
2156         SLIST_INIT(&drl);
2157         for (;;) {
2158                 UNP_DEFERRED_LOCK();
2159                 if (SLIST_FIRST(&unp_defers) == NULL) {
2160                         UNP_DEFERRED_UNLOCK();
2161                         break;
2162                 }
2163                 SLIST_SWAP(&unp_defers, &drl, unp_defer);
2164                 UNP_DEFERRED_UNLOCK();
2165                 count = 0;
2166                 while ((dr = SLIST_FIRST(&drl)) != NULL) {
2167                         SLIST_REMOVE_HEAD(&drl, ud_link);
2168                         closef(dr->ud_fp, NULL);
2169                         free(dr, M_TEMP);
2170                         count++;
2171                 }
2172                 atomic_add_int(&unp_defers_count, -count);
2173         }
2174 }
2175
2176 static void
2177 unp_internalize_fp(struct file *fp)
2178 {
2179         struct unpcb *unp;
2180
2181         UNP_LINK_WLOCK();
2182         if ((unp = fptounp(fp)) != NULL) {
2183                 unp->unp_file = fp;
2184                 unp->unp_msgcount++;
2185         }
2186         fhold(fp);
2187         unp_rights++;
2188         UNP_LINK_WUNLOCK();
2189 }
2190
2191 static int
2192 unp_externalize_fp(struct file *fp)
2193 {
2194         struct unpcb *unp;
2195         int ret;
2196
2197         UNP_LINK_WLOCK();
2198         if ((unp = fptounp(fp)) != NULL) {
2199                 unp->unp_msgcount--;
2200                 ret = 1;
2201         } else
2202                 ret = 0;
2203         unp_rights--;
2204         UNP_LINK_WUNLOCK();
2205         return (ret);
2206 }
2207
2208 /*
2209  * unp_defer indicates whether additional work has been defered for a future
2210  * pass through unp_gc().  It is thread local and does not require explicit
2211  * synchronization.
2212  */
2213 static int      unp_marked;
2214 static int      unp_unreachable;
2215
2216 static void
2217 unp_accessable(struct filedescent **fdep, int fdcount)
2218 {
2219         struct unpcb *unp;
2220         struct file *fp;
2221         int i;
2222
2223         for (i = 0; i < fdcount; i++) {
2224                 fp = fdep[i]->fde_file;
2225                 if ((unp = fptounp(fp)) == NULL)
2226                         continue;
2227                 if (unp->unp_gcflag & UNPGC_REF)
2228                         continue;
2229                 unp->unp_gcflag &= ~UNPGC_DEAD;
2230                 unp->unp_gcflag |= UNPGC_REF;
2231                 unp_marked++;
2232         }
2233 }
2234
2235 static void
2236 unp_gc_process(struct unpcb *unp)
2237 {
2238         struct socket *so, *soa;
2239         struct file *fp;
2240
2241         /* Already processed. */
2242         if (unp->unp_gcflag & UNPGC_SCANNED)
2243                 return;
2244         fp = unp->unp_file;
2245
2246         /*
2247          * Check for a socket potentially in a cycle.  It must be in a
2248          * queue as indicated by msgcount, and this must equal the file
2249          * reference count.  Note that when msgcount is 0 the file is NULL.
2250          */
2251         if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp &&
2252             unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) {
2253                 unp->unp_gcflag |= UNPGC_DEAD;
2254                 unp_unreachable++;
2255                 return;
2256         }
2257
2258         so = unp->unp_socket;
2259         SOCK_LOCK(so);
2260         if (SOLISTENING(so)) {
2261                 /*
2262                  * Mark all sockets in our accept queue.
2263                  */
2264                 TAILQ_FOREACH(soa, &so->sol_comp, so_list) {
2265                         if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS)
2266                                 continue;
2267                         SOCKBUF_LOCK(&soa->so_rcv);
2268                         unp_scan(soa->so_rcv.sb_mb, unp_accessable);
2269                         SOCKBUF_UNLOCK(&soa->so_rcv);
2270                 }
2271         } else {
2272                 /*
2273                  * Mark all sockets we reference with RIGHTS.
2274                  */
2275                 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) {
2276                         SOCKBUF_LOCK(&so->so_rcv);
2277                         unp_scan(so->so_rcv.sb_mb, unp_accessable);
2278                         SOCKBUF_UNLOCK(&so->so_rcv);
2279                 }
2280         }
2281         SOCK_UNLOCK(so);
2282         unp->unp_gcflag |= UNPGC_SCANNED;
2283 }
2284
2285 static int unp_recycled;
2286 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0,
2287     "Number of unreachable sockets claimed by the garbage collector.");
2288
2289 static int unp_taskcount;
2290 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0,
2291     "Number of times the garbage collector has run.");
2292
2293 static void
2294 unp_gc(__unused void *arg, int pending)
2295 {
2296         struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead,
2297                                     NULL };
2298         struct unp_head **head;
2299         struct file *f, **unref;
2300         struct unpcb *unp;
2301         int i, total;
2302
2303         unp_taskcount++;
2304         UNP_LINK_RLOCK();
2305         /*
2306          * First clear all gc flags from previous runs, apart from
2307          * UNPGC_IGNORE_RIGHTS.
2308          */
2309         for (head = heads; *head != NULL; head++)
2310                 LIST_FOREACH(unp, *head, unp_link)
2311                         unp->unp_gcflag =
2312                             (unp->unp_gcflag & UNPGC_IGNORE_RIGHTS);
2313
2314         /*
2315          * Scan marking all reachable sockets with UNPGC_REF.  Once a socket
2316          * is reachable all of the sockets it references are reachable.
2317          * Stop the scan once we do a complete loop without discovering
2318          * a new reachable socket.
2319          */
2320         do {
2321                 unp_unreachable = 0;
2322                 unp_marked = 0;
2323                 for (head = heads; *head != NULL; head++)
2324                         LIST_FOREACH(unp, *head, unp_link)
2325                                 unp_gc_process(unp);
2326         } while (unp_marked);
2327         UNP_LINK_RUNLOCK();
2328         if (unp_unreachable == 0)
2329                 return;
2330
2331         /*
2332          * Allocate space for a local list of dead unpcbs.
2333          */
2334         unref = malloc(unp_unreachable * sizeof(struct file *),
2335             M_TEMP, M_WAITOK);
2336
2337         /*
2338          * Iterate looking for sockets which have been specifically marked
2339          * as as unreachable and store them locally.
2340          */
2341         UNP_LINK_RLOCK();
2342         for (total = 0, head = heads; *head != NULL; head++)
2343                 LIST_FOREACH(unp, *head, unp_link)
2344                         if ((unp->unp_gcflag & UNPGC_DEAD) != 0) {
2345                                 f = unp->unp_file;
2346                                 if (unp->unp_msgcount == 0 || f == NULL ||
2347                                     f->f_count != unp->unp_msgcount)
2348                                         continue;
2349                                 unref[total++] = f;
2350                                 fhold(f);
2351                                 KASSERT(total <= unp_unreachable,
2352                                     ("unp_gc: incorrect unreachable count."));
2353                         }
2354         UNP_LINK_RUNLOCK();
2355
2356         /*
2357          * Now flush all sockets, free'ing rights.  This will free the
2358          * struct files associated with these sockets but leave each socket
2359          * with one remaining ref.
2360          */
2361         for (i = 0; i < total; i++) {
2362                 struct socket *so;
2363
2364                 so = unref[i]->f_data;
2365                 CURVNET_SET(so->so_vnet);
2366                 sorflush(so);
2367                 CURVNET_RESTORE();
2368         }
2369
2370         /*
2371          * And finally release the sockets so they can be reclaimed.
2372          */
2373         for (i = 0; i < total; i++)
2374                 fdrop(unref[i], NULL);
2375         unp_recycled += total;
2376         free(unref, M_TEMP);
2377 }
2378
2379 static void
2380 unp_dispose_mbuf(struct mbuf *m)
2381 {
2382
2383         if (m)
2384                 unp_scan(m, unp_freerights);
2385 }
2386
2387 /*
2388  * Synchronize against unp_gc, which can trip over data as we are freeing it.
2389  */
2390 static void
2391 unp_dispose(struct socket *so)
2392 {
2393         struct unpcb *unp;
2394
2395         unp = sotounpcb(so);
2396         UNP_LINK_WLOCK();
2397         unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS;
2398         UNP_LINK_WUNLOCK();
2399         if (!SOLISTENING(so))
2400                 unp_dispose_mbuf(so->so_rcv.sb_mb);
2401 }
2402
2403 static void
2404 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int))
2405 {
2406         struct mbuf *m;
2407         struct cmsghdr *cm;
2408         void *data;
2409         socklen_t clen, datalen;
2410
2411         while (m0 != NULL) {
2412                 for (m = m0; m; m = m->m_next) {
2413                         if (m->m_type != MT_CONTROL)
2414                                 continue;
2415
2416                         cm = mtod(m, struct cmsghdr *);
2417                         clen = m->m_len;
2418
2419                         while (cm != NULL) {
2420                                 if (sizeof(*cm) > clen || cm->cmsg_len > clen)
2421                                         break;
2422
2423                                 data = CMSG_DATA(cm);
2424                                 datalen = (caddr_t)cm + cm->cmsg_len
2425                                     - (caddr_t)data;
2426
2427                                 if (cm->cmsg_level == SOL_SOCKET &&
2428                                     cm->cmsg_type == SCM_RIGHTS) {
2429                                         (*op)(data, datalen /
2430                                             sizeof(struct filedescent *));
2431                                 }
2432
2433                                 if (CMSG_SPACE(datalen) < clen) {
2434                                         clen -= CMSG_SPACE(datalen);
2435                                         cm = (struct cmsghdr *)
2436                                             ((caddr_t)cm + CMSG_SPACE(datalen));
2437                                 } else {
2438                                         clen = 0;
2439                                         cm = NULL;
2440                                 }
2441                         }
2442                 }
2443                 m0 = m0->m_nextpkt;
2444         }
2445 }
2446
2447 /*
2448  * A helper function called by VFS before socket-type vnode reclamation.
2449  * For an active vnode it clears unp_vnode pointer and decrements unp_vnode
2450  * use count.
2451  */
2452 void
2453 vfs_unp_reclaim(struct vnode *vp)
2454 {
2455         struct unpcb *unp;
2456         int active;
2457
2458         ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim");
2459         KASSERT(vp->v_type == VSOCK,
2460             ("vfs_unp_reclaim: vp->v_type != VSOCK"));
2461
2462         active = 0;
2463         UNP_LINK_WLOCK();
2464         VOP_UNP_CONNECT(vp, &unp);
2465         if (unp == NULL)
2466                 goto done;
2467         UNP_PCB_LOCK(unp);
2468         if (unp->unp_vnode == vp) {
2469                 VOP_UNP_DETACH(vp);
2470                 unp->unp_vnode = NULL;
2471                 active = 1;
2472         }
2473         UNP_PCB_UNLOCK(unp);
2474 done:
2475         UNP_LINK_WUNLOCK();
2476         if (active)
2477                 vunref(vp);
2478 }
2479
2480 #ifdef DDB
2481 static void
2482 db_print_indent(int indent)
2483 {
2484         int i;
2485
2486         for (i = 0; i < indent; i++)
2487                 db_printf(" ");
2488 }
2489
2490 static void
2491 db_print_unpflags(int unp_flags)
2492 {
2493         int comma;
2494
2495         comma = 0;
2496         if (unp_flags & UNP_HAVEPC) {
2497                 db_printf("%sUNP_HAVEPC", comma ? ", " : "");
2498                 comma = 1;
2499         }
2500         if (unp_flags & UNP_WANTCRED) {
2501                 db_printf("%sUNP_WANTCRED", comma ? ", " : "");
2502                 comma = 1;
2503         }
2504         if (unp_flags & UNP_CONNWAIT) {
2505                 db_printf("%sUNP_CONNWAIT", comma ? ", " : "");
2506                 comma = 1;
2507         }
2508         if (unp_flags & UNP_CONNECTING) {
2509                 db_printf("%sUNP_CONNECTING", comma ? ", " : "");
2510                 comma = 1;
2511         }
2512         if (unp_flags & UNP_BINDING) {
2513                 db_printf("%sUNP_BINDING", comma ? ", " : "");
2514                 comma = 1;
2515         }
2516 }
2517
2518 static void
2519 db_print_xucred(int indent, struct xucred *xu)
2520 {
2521         int comma, i;
2522
2523         db_print_indent(indent);
2524         db_printf("cr_version: %u   cr_uid: %u   cr_ngroups: %d\n",
2525             xu->cr_version, xu->cr_uid, xu->cr_ngroups);
2526         db_print_indent(indent);
2527         db_printf("cr_groups: ");
2528         comma = 0;
2529         for (i = 0; i < xu->cr_ngroups; i++) {
2530                 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
2531                 comma = 1;
2532         }
2533         db_printf("\n");
2534 }
2535
2536 static void
2537 db_print_unprefs(int indent, struct unp_head *uh)
2538 {
2539         struct unpcb *unp;
2540         int counter;
2541
2542         counter = 0;
2543         LIST_FOREACH(unp, uh, unp_reflink) {
2544                 if (counter % 4 == 0)
2545                         db_print_indent(indent);
2546                 db_printf("%p  ", unp);
2547                 if (counter % 4 == 3)
2548                         db_printf("\n");
2549                 counter++;
2550         }
2551         if (counter != 0 && counter % 4 != 0)
2552                 db_printf("\n");
2553 }
2554
2555 DB_SHOW_COMMAND(unpcb, db_show_unpcb)
2556 {
2557         struct unpcb *unp;
2558
2559         if (!have_addr) {
2560                 db_printf("usage: show unpcb <addr>\n");
2561                 return;
2562         }
2563         unp = (struct unpcb *)addr;
2564
2565         db_printf("unp_socket: %p   unp_vnode: %p\n", unp->unp_socket,
2566             unp->unp_vnode);
2567
2568         db_printf("unp_ino: %ju   unp_conn: %p\n", (uintmax_t)unp->unp_ino,
2569             unp->unp_conn);
2570
2571         db_printf("unp_refs:\n");
2572         db_print_unprefs(2, &unp->unp_refs);
2573
2574         /* XXXRW: Would be nice to print the full address, if any. */
2575         db_printf("unp_addr: %p\n", unp->unp_addr);
2576
2577         db_printf("unp_gencnt: %llu\n",
2578             (unsigned long long)unp->unp_gencnt);
2579
2580         db_printf("unp_flags: %x (", unp->unp_flags);
2581         db_print_unpflags(unp->unp_flags);
2582         db_printf(")\n");
2583
2584         db_printf("unp_peercred:\n");
2585         db_print_xucred(2, &unp->unp_peercred);
2586
2587         db_printf("unp_refcount: %u\n", unp->unp_refcount);
2588 }
2589 #endif