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  * 4. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94
  32  */
  33
  34 /*
  35  * UNIX Domain (Local) Sockets
  36  *
  37  * This is an implementation of UNIX (local) domain sockets.  Each socket has
  38  * an associated struct unpcb (UNIX protocol control block).  Stream sockets
  39  * may be connected to 0 or 1 other socket.  Datagram sockets may be
  40  * connected to 0, 1, or many other sockets.  Sockets may be created and
  41  * connected in pairs (socketpair(2)), or bound/connected to using the file
  42  * system name space.  For most purposes, only the receive socket buffer is
  43  * used, as sending on one socket delivers directly to the receive socket
  44  * buffer of a second socket.
  45  *
  46  * The implementation is substantially complicated by the fact that
  47  * "ancillary data", such as file descriptors or credentials, may be passed
  48  * across UNIX domain sockets.  The potential for passing UNIX domain sockets
  49  * over other UNIX domain sockets requires the implementation of a simple
  50  * garbage collector to find and tear down cycles of disconnected sockets.
  51  *
  52  * TODO:
  53  *      RDM
  54  *      rethink name space problems
  55  *      need a proper out-of-band
  56  */
  57
  58 #include <sys/cdefs.h>
  59 __FBSDID("$FreeBSD$");
  60
  61 #include "opt_ddb.h"
  62
  63 #include <sys/param.h>
  64 #include <sys/capsicum.h>
  65 #include <sys/domain.h>
  66 #include <sys/fcntl.h>
  67 #include <sys/malloc.h>         /* XXX must be before <sys/file.h> */
  68 #include <sys/eventhandler.h>
  69 #include <sys/file.h>
  70 #include <sys/filedesc.h>
  71 #include <sys/kernel.h>
  72 #include <sys/lock.h>
  73 #include <sys/mbuf.h>
  74 #include <sys/mount.h>
  75 #include <sys/mutex.h>
  76 #include <sys/namei.h>
  77 #include <sys/proc.h>
  78 #include <sys/protosw.h>
  79 #include <sys/queue.h>
  80 #include <sys/resourcevar.h>
  81 #include <sys/rwlock.h>
  82 #include <sys/socket.h>
  83 #include <sys/socketvar.h>
  84 #include <sys/signalvar.h>
  85 #include <sys/stat.h>
  86 #include <sys/sx.h>
  87 #include <sys/sysctl.h>
  88 #include <sys/systm.h>
  89 #include <sys/taskqueue.h>
  90 #include <sys/un.h>
  91 #include <sys/unpcb.h>
  92 #include <sys/vnode.h>
  93
  94 #include <net/vnet.h>
  95
  96 #ifdef DDB
  97 #include <ddb/ddb.h>
  98 #endif
  99
 100 #include <security/mac/mac_framework.h>
 101
 102 #include <vm/uma.h>
 103
 104 MALLOC_DECLARE(M_FILECAPS);
 105
 106 /*
 107  * Locking key:
 108  * (l)  Locked using list lock
 109  * (g)  Locked using linkage lock
 110  */
 111
 112 static uma_zone_t       unp_zone;
 113 static unp_gen_t        unp_gencnt;     /* (l) */
 114 static u_int            unp_count;      /* (l) Count of local sockets. */
 115 static ino_t            unp_ino;        /* Prototype for fake inode numbers. */
 116 static int              unp_rights;     /* (g) File descriptors in flight. */
 117 static struct unp_head  unp_shead;      /* (l) List of stream sockets. */
 118 static struct unp_head  unp_dhead;      /* (l) List of datagram sockets. */
 119 static struct unp_head  unp_sphead;     /* (l) List of seqpacket sockets. */
 120
 121 struct unp_defer {
 122         SLIST_ENTRY(unp_defer) ud_link;
 123         struct file *ud_fp;
 124 };
 125 static SLIST_HEAD(, unp_defer) unp_defers;
 126 static int unp_defers_count;
 127
 128 static const struct sockaddr    sun_noname = { sizeof(sun_noname), AF_LOCAL };
 129
 130 /*
 131  * Garbage collection of cyclic file descriptor/socket references occurs
 132  * asynchronously in a taskqueue context in order to avoid recursion and
 133  * reentrance in the UNIX domain socket, file descriptor, and socket layer
 134  * code.  See unp_gc() for a full description.
 135  */
 136 static struct timeout_task unp_gc_task;
 137
 138 /*
 139  * The close of unix domain sockets attached as SCM_RIGHTS is
 140  * postponed to the taskqueue, to avoid arbitrary recursion depth.
 141  * The attached sockets might have another sockets attached.
 142  */
 143 static struct task      unp_defer_task;
 144
 145 /*
 146  * Both send and receive buffers are allocated PIPSIZ bytes of buffering for
 147  * stream sockets, although the total for sender and receiver is actually
 148  * only PIPSIZ.
 149  *
 150  * Datagram sockets really use the sendspace as the maximum datagram size,
 151  * and don't really want to reserve the sendspace.  Their recvspace should be
 152  * large enough for at least one max-size datagram plus address.
 153  */
 154 #ifndef PIPSIZ
 155 #define PIPSIZ  8192
 156 #endif
 157 static u_long   unpst_sendspace = PIPSIZ;
 158 static u_long   unpst_recvspace = PIPSIZ;
 159 static u_long   unpdg_sendspace = 2*1024;       /* really max datagram size */
 160 static u_long   unpdg_recvspace = 4*1024;
 161 static u_long   unpsp_sendspace = PIPSIZ;       /* really max datagram size */
 162 static u_long   unpsp_recvspace = PIPSIZ;
 163
 164 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain");
 165 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0,
 166     "SOCK_STREAM");
 167 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM");
 168 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, CTLFLAG_RW, 0,
 169     "SOCK_SEQPACKET");
 170
 171 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW,
 172            &unpst_sendspace, 0, "Default stream send space.");
 173 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW,
 174            &unpst_recvspace, 0, "Default stream receive space.");
 175 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW,
 176            &unpdg_sendspace, 0, "Default datagram send space.");
 177 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW,
 178            &unpdg_recvspace, 0, "Default datagram receive space.");
 179 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW,
 180            &unpsp_sendspace, 0, "Default seqpacket send space.");
 181 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW,
 182            &unpsp_recvspace, 0, "Default seqpacket receive space.");
 183 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0,
 184     "File descriptors in flight.");
 185 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD,
 186     &unp_defers_count, 0,
 187     "File descriptors deferred to taskqueue for close.");
 188
 189 /*
 190  * Locking and synchronization:
 191  *
 192  * Three types of locks exit in the local domain socket implementation: a
 193  * global list mutex, a global linkage rwlock, and per-unpcb mutexes.  Of the
 194  * global locks, the list lock protects the socket count, global generation
 195  * number, and stream/datagram global lists.  The linkage lock protects the
 196  * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be
 197  * held exclusively over the acquisition of multiple unpcb locks to prevent
 198  * deadlock.
 199  *
 200  * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer,
 201  * allocated in pru_attach() and freed in pru_detach().  The validity of that
 202  * pointer is an invariant, so no lock is required to dereference the so_pcb
 203  * pointer if a valid socket reference is held by the caller.  In practice,
 204  * this is always true during operations performed on a socket.  Each unpcb
 205  * has a back-pointer to its socket, unp_socket, which will be stable under
 206  * the same circumstances.
 207  *
 208  * This pointer may only be safely dereferenced as long as a valid reference
 209  * to the unpcb is held.  Typically, this reference will be from the socket,
 210  * or from another unpcb when the referring unpcb's lock is held (in order
 211  * that the reference not be invalidated during use).  For example, to follow
 212  * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn,
 213  * as unp_socket remains valid as long as the reference to unp_conn is valid.
 214  *
 215  * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx.  Individual
 216  * atomic reads without the lock may be performed "lockless", but more
 217  * complex reads and read-modify-writes require the mutex to be held.  No
 218  * lock order is defined between unpcb locks -- multiple unpcb locks may be
 219  * acquired at the same time only when holding the linkage rwlock
 220  * exclusively, which prevents deadlocks.
 221  *
 222  * Blocking with UNIX domain sockets is a tricky issue: unlike most network
 223  * protocols, bind() is a non-atomic operation, and connect() requires
 224  * potential sleeping in the protocol, due to potentially waiting on local or
 225  * distributed file systems.  We try to separate "lookup" operations, which
 226  * may sleep, and the IPC operations themselves, which typically can occur
 227  * with relative atomicity as locks can be held over the entire operation.
 228  *
 229  * Another tricky issue is simultaneous multi-threaded or multi-process
 230  * access to a single UNIX domain socket.  These are handled by the flags
 231  * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or
 232  * binding, both of which involve dropping UNIX domain socket locks in order
 233  * to perform namei() and other file system operations.
 234  */
 235 static struct rwlock    unp_link_rwlock;
 236 static struct mtx       unp_list_lock;
 237 static struct mtx       unp_defers_lock;
 238
 239 #define UNP_LINK_LOCK_INIT()            rw_init(&unp_link_rwlock,       \
 240                                             "unp_link_rwlock")
 241
 242 #define UNP_LINK_LOCK_ASSERT()  rw_assert(&unp_link_rwlock,     \
 243                                             RA_LOCKED)
 244 #define UNP_LINK_UNLOCK_ASSERT()        rw_assert(&unp_link_rwlock,     \
 245                                             RA_UNLOCKED)
 246
 247 #define UNP_LINK_RLOCK()                rw_rlock(&unp_link_rwlock)
 248 #define UNP_LINK_RUNLOCK()              rw_runlock(&unp_link_rwlock)
 249 #define UNP_LINK_WLOCK()                rw_wlock(&unp_link_rwlock)
 250 #define UNP_LINK_WUNLOCK()              rw_wunlock(&unp_link_rwlock)
 251 #define UNP_LINK_WLOCK_ASSERT()         rw_assert(&unp_link_rwlock,     \
 252                                             RA_WLOCKED)
 253
 254 #define UNP_LIST_LOCK_INIT()            mtx_init(&unp_list_lock,        \
 255                                             "unp_list_lock", NULL, MTX_DEF)
 256 #define UNP_LIST_LOCK()                 mtx_lock(&unp_list_lock)
 257 #define UNP_LIST_UNLOCK()               mtx_unlock(&unp_list_lock)
 258
 259 #define UNP_DEFERRED_LOCK_INIT()        mtx_init(&unp_defers_lock, \
 260                                             "unp_defer", NULL, MTX_DEF)
 261 #define UNP_DEFERRED_LOCK()             mtx_lock(&unp_defers_lock)
 262 #define UNP_DEFERRED_UNLOCK()           mtx_unlock(&unp_defers_lock)
 263
 264 #define UNP_PCB_LOCK_INIT(unp)          mtx_init(&(unp)->unp_mtx,       \
 265                                             "unp_mtx", "unp_mtx",       \
 266                                             MTX_DUPOK|MTX_DEF|MTX_RECURSE)
 267 #define UNP_PCB_LOCK_DESTROY(unp)       mtx_destroy(&(unp)->unp_mtx)
 268 #define UNP_PCB_LOCK(unp)               mtx_lock(&(unp)->unp_mtx)
 269 #define UNP_PCB_UNLOCK(unp)             mtx_unlock(&(unp)->unp_mtx)
 270 #define UNP_PCB_LOCK_ASSERT(unp)        mtx_assert(&(unp)->unp_mtx, MA_OWNED)
 271
 272 static int      uipc_connect2(struct socket *, struct socket *);
 273 static int      uipc_ctloutput(struct socket *, struct sockopt *);
 274 static int      unp_connect(struct socket *, struct sockaddr *,
 275                     struct thread *);
 276 static int      unp_connectat(int, struct socket *, struct sockaddr *,
 277                     struct thread *);
 278 static int      unp_connect2(struct socket *so, struct socket *so2, int);
 279 static void     unp_disconnect(struct unpcb *unp, struct unpcb *unp2);
 280 static void     unp_dispose(struct mbuf *);
 281 static void     unp_shutdown(struct unpcb *);
 282 static void     unp_drop(struct unpcb *, int);
 283 static void     unp_gc(__unused void *, int);
 284 static void     unp_scan(struct mbuf *, void (*)(struct filedescent **, int));
 285 static void     unp_discard(struct file *);
 286 static void     unp_freerights(struct filedescent **, int);
 287 static void     unp_init(void);
 288 static int      unp_internalize(struct mbuf **, struct thread *);
 289 static void     unp_internalize_fp(struct file *);
 290 static int      unp_externalize(struct mbuf *, struct mbuf **, int);
 291 static int      unp_externalize_fp(struct file *);
 292 static struct mbuf      *unp_addsockcred(struct thread *, struct mbuf *);
 293 static void     unp_process_defers(void * __unused, int);
 294
 295 /*
 296  * Definitions of protocols supported in the LOCAL domain.
 297  */
 298 static struct domain localdomain;
 299 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream;
 300 static struct pr_usrreqs uipc_usrreqs_seqpacket;
 301 static struct protosw localsw[] = {
 302 {
 303         .pr_type =              SOCK_STREAM,
 304         .pr_domain =            &localdomain,
 305         .pr_flags =             PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS,
 306         .pr_ctloutput =         &uipc_ctloutput,
 307         .pr_usrreqs =           &uipc_usrreqs_stream
 308 },
 309 {
 310         .pr_type =              SOCK_DGRAM,
 311         .pr_domain =            &localdomain,
 312         .pr_flags =             PR_ATOMIC|PR_ADDR|PR_RIGHTS,
 313         .pr_ctloutput =         &uipc_ctloutput,
 314         .pr_usrreqs =           &uipc_usrreqs_dgram
 315 },
 316 {
 317         .pr_type =              SOCK_SEQPACKET,
 318         .pr_domain =            &localdomain,
 319
 320         /*
 321          * XXXRW: For now, PR_ADDR because soreceive will bump into them
 322          * due to our use of sbappendaddr.  A new sbappend variants is needed
 323          * that supports both atomic record writes and control data.
 324          */
 325         .pr_flags =             PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD|
 326                                     PR_RIGHTS,
 327         .pr_ctloutput =         &uipc_ctloutput,
 328         .pr_usrreqs =           &uipc_usrreqs_seqpacket,
 329 },
 330 };
 331
 332 static struct domain localdomain = {
 333         .dom_family =           AF_LOCAL,
 334         .dom_name =             "local",
 335         .dom_init =             unp_init,
 336         .dom_externalize =      unp_externalize,
 337         .dom_dispose =          unp_dispose,
 338         .dom_protosw =          localsw,
 339         .dom_protoswNPROTOSW =  &localsw[sizeof(localsw)/sizeof(localsw[0])]
 340 };
 341 DOMAIN_SET(local);
 342
 343 static void
 344 uipc_abort(struct socket *so)
 345 {
 346         struct unpcb *unp, *unp2;
 347
 348         unp = sotounpcb(so);
 349         KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
 350
 351         UNP_LINK_WLOCK();
 352         UNP_PCB_LOCK(unp);
 353         unp2 = unp->unp_conn;
 354         if (unp2 != NULL) {
 355                 UNP_PCB_LOCK(unp2);
 356                 unp_drop(unp2, ECONNABORTED);
 357                 UNP_PCB_UNLOCK(unp2);
 358         }
 359         UNP_PCB_UNLOCK(unp);
 360         UNP_LINK_WUNLOCK();
 361 }
 362
 363 static int
 364 uipc_accept(struct socket *so, struct sockaddr **nam)
 365 {
 366         struct unpcb *unp, *unp2;
 367         const struct sockaddr *sa;
 368
 369         /*
 370          * Pass back name of connected socket, if it was bound and we are
 371          * still connected (our peer may have closed already!).
 372          */
 373         unp = sotounpcb(so);
 374         KASSERT(unp != NULL, ("uipc_accept: unp == NULL"));
 375
 376         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 377         UNP_LINK_RLOCK();
 378         unp2 = unp->unp_conn;
 379         if (unp2 != NULL && unp2->unp_addr != NULL) {
 380                 UNP_PCB_LOCK(unp2);
 381                 sa = (struct sockaddr *) unp2->unp_addr;
 382                 bcopy(sa, *nam, sa->sa_len);
 383                 UNP_PCB_UNLOCK(unp2);
 384         } else {
 385                 sa = &sun_noname;
 386                 bcopy(sa, *nam, sa->sa_len);
 387         }
 388         UNP_LINK_RUNLOCK();
 389         return (0);
 390 }
 391
 392 static int
 393 uipc_attach(struct socket *so, int proto, struct thread *td)
 394 {
 395         u_long sendspace, recvspace;
 396         struct unpcb *unp;
 397         int error;
 398
 399         KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
 400         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 401                 switch (so->so_type) {
 402                 case SOCK_STREAM:
 403                         sendspace = unpst_sendspace;
 404                         recvspace = unpst_recvspace;
 405                         break;
 406
 407                 case SOCK_DGRAM:
 408                         sendspace = unpdg_sendspace;
 409                         recvspace = unpdg_recvspace;
 410                         break;
 411
 412                 case SOCK_SEQPACKET:
 413                         sendspace = unpsp_sendspace;
 414                         recvspace = unpsp_recvspace;
 415                         break;
 416
 417                 default:
 418                         panic("uipc_attach");
 419                 }
 420                 error = soreserve(so, sendspace, recvspace);
 421                 if (error)
 422                         return (error);
 423         }
 424         unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
 425         if (unp == NULL)
 426                 return (ENOBUFS);
 427         LIST_INIT(&unp->unp_refs);
 428         UNP_PCB_LOCK_INIT(unp);
 429         unp->unp_socket = so;
 430         so->so_pcb = unp;
 431         unp->unp_refcount = 1;
 432         if (so->so_head != NULL)
 433                 unp->unp_flags |= UNP_NASCENT;
 434
 435         UNP_LIST_LOCK();
 436         unp->unp_gencnt = ++unp_gencnt;
 437         unp_count++;
 438         switch (so->so_type) {
 439         case SOCK_STREAM:
 440                 LIST_INSERT_HEAD(&unp_shead, unp, unp_link);
 441                 break;
 442
 443         case SOCK_DGRAM:
 444                 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link);
 445                 break;
 446
 447         case SOCK_SEQPACKET:
 448                 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link);
 449                 break;
 450
 451         default:
 452                 panic("uipc_attach");
 453         }
 454         UNP_LIST_UNLOCK();
 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->unp_socket);
 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
 610         unp = sotounpcb(so);
 611         KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
 612
 613         UNP_LINK_WLOCK();
 614         UNP_PCB_LOCK(unp);
 615         unp2 = unp->unp_conn;
 616         if (unp2 != NULL) {
 617                 UNP_PCB_LOCK(unp2);
 618                 unp_disconnect(unp, unp2);
 619                 UNP_PCB_UNLOCK(unp2);
 620         }
 621         UNP_PCB_UNLOCK(unp);
 622         UNP_LINK_WUNLOCK();
 623 }
 624
 625 static int
 626 uipc_connect2(struct socket *so1, struct socket *so2)
 627 {
 628         struct unpcb *unp, *unp2;
 629         int error;
 630
 631         UNP_LINK_WLOCK();
 632         unp = so1->so_pcb;
 633         KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
 634         UNP_PCB_LOCK(unp);
 635         unp2 = so2->so_pcb;
 636         KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
 637         UNP_PCB_LOCK(unp2);
 638         error = unp_connect2(so1, so2, PRU_CONNECT2);
 639         UNP_PCB_UNLOCK(unp2);
 640         UNP_PCB_UNLOCK(unp);
 641         UNP_LINK_WUNLOCK();
 642         return (error);
 643 }
 644
 645 static void
 646 uipc_detach(struct socket *so)
 647 {
 648         struct unpcb *unp, *unp2;
 649         struct sockaddr_un *saved_unp_addr;
 650         struct vnode *vp;
 651         int freeunp, local_unp_rights;
 652
 653         unp = sotounpcb(so);
 654         KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
 655
 656         vp = NULL;
 657         local_unp_rights = 0;
 658
 659         UNP_LIST_LOCK();
 660         LIST_REMOVE(unp, unp_link);
 661         unp->unp_gencnt = ++unp_gencnt;
 662         --unp_count;
 663         UNP_LIST_UNLOCK();
 664
 665         if ((unp->unp_flags & UNP_NASCENT) != 0) {
 666                 UNP_PCB_LOCK(unp);
 667                 goto teardown;
 668         }
 669         UNP_LINK_WLOCK();
 670         UNP_PCB_LOCK(unp);
 671
 672         /*
 673          * XXXRW: Should assert vp->v_socket == so.
 674          */
 675         if ((vp = unp->unp_vnode) != NULL) {
 676                 VOP_UNP_DETACH(vp);
 677                 unp->unp_vnode = NULL;
 678         }
 679         unp2 = unp->unp_conn;
 680         if (unp2 != NULL) {
 681                 UNP_PCB_LOCK(unp2);
 682                 unp_disconnect(unp, unp2);
 683                 UNP_PCB_UNLOCK(unp2);
 684         }
 685
 686         /*
 687          * We hold the linkage lock exclusively, so it's OK to acquire
 688          * multiple pcb locks at a time.
 689          */
 690         while (!LIST_EMPTY(&unp->unp_refs)) {
 691                 struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
 692
 693                 UNP_PCB_LOCK(ref);
 694                 unp_drop(ref, ECONNRESET);
 695                 UNP_PCB_UNLOCK(ref);
 696         }
 697         local_unp_rights = unp_rights;
 698         UNP_LINK_WUNLOCK();
 699 teardown:
 700         unp->unp_socket->so_pcb = NULL;
 701         saved_unp_addr = unp->unp_addr;
 702         unp->unp_addr = NULL;
 703         unp->unp_refcount--;
 704         freeunp = (unp->unp_refcount == 0);
 705         if (saved_unp_addr != NULL)
 706                 free(saved_unp_addr, M_SONAME);
 707         if (freeunp) {
 708                 UNP_PCB_LOCK_DESTROY(unp);
 709                 uma_zfree(unp_zone, unp);
 710         } else
 711                 UNP_PCB_UNLOCK(unp);
 712         if (vp)
 713                 vrele(vp);
 714         if (local_unp_rights)
 715                 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1);
 716 }
 717
 718 static int
 719 uipc_disconnect(struct socket *so)
 720 {
 721         struct unpcb *unp, *unp2;
 722
 723         unp = sotounpcb(so);
 724         KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
 725
 726         UNP_LINK_WLOCK();
 727         UNP_PCB_LOCK(unp);
 728         unp2 = unp->unp_conn;
 729         if (unp2 != NULL) {
 730                 UNP_PCB_LOCK(unp2);
 731                 unp_disconnect(unp, unp2);
 732                 UNP_PCB_UNLOCK(unp2);
 733         }
 734         UNP_PCB_UNLOCK(unp);
 735         UNP_LINK_WUNLOCK();
 736         return (0);
 737 }
 738
 739 static int
 740 uipc_listen(struct socket *so, int backlog, struct thread *td)
 741 {
 742         struct unpcb *unp;
 743         int error;
 744
 745         unp = sotounpcb(so);
 746         KASSERT(unp != NULL, ("uipc_listen: unp == NULL"));
 747
 748         UNP_PCB_LOCK(unp);
 749         if (unp->unp_vnode == NULL) {
 750                 UNP_PCB_UNLOCK(unp);
 751                 return (EINVAL);
 752         }
 753
 754         SOCK_LOCK(so);
 755         error = solisten_proto_check(so);
 756         if (error == 0) {
 757                 cru2x(td->td_ucred, &unp->unp_peercred);
 758                 unp->unp_flags |= UNP_HAVEPCCACHED;
 759                 solisten_proto(so, backlog);
 760         }
 761         SOCK_UNLOCK(so);
 762         UNP_PCB_UNLOCK(unp);
 763         return (error);
 764 }
 765
 766 static int
 767 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
 768 {
 769         struct unpcb *unp, *unp2;
 770         const struct sockaddr *sa;
 771
 772         unp = sotounpcb(so);
 773         KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
 774
 775         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 776         UNP_LINK_RLOCK();
 777         /*
 778          * XXX: It seems that this test always fails even when connection is
 779          * established.  So, this else clause is added as workaround to
 780          * return PF_LOCAL sockaddr.
 781          */
 782         unp2 = unp->unp_conn;
 783         if (unp2 != NULL) {
 784                 UNP_PCB_LOCK(unp2);
 785                 if (unp2->unp_addr != NULL)
 786                         sa = (struct sockaddr *) unp2->unp_addr;
 787                 else
 788                         sa = &sun_noname;
 789                 bcopy(sa, *nam, sa->sa_len);
 790                 UNP_PCB_UNLOCK(unp2);
 791         } else {
 792                 sa = &sun_noname;
 793                 bcopy(sa, *nam, sa->sa_len);
 794         }
 795         UNP_LINK_RUNLOCK();
 796         return (0);
 797 }
 798
 799 static int
 800 uipc_rcvd(struct socket *so, int flags)
 801 {
 802         struct unpcb *unp, *unp2;
 803         struct socket *so2;
 804         u_int mbcnt, sbcc;
 805
 806         unp = sotounpcb(so);
 807         KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL"));
 808
 809         if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET)
 810                 panic("uipc_rcvd socktype %d", so->so_type);
 811
 812         /*
 813          * Adjust backpressure on sender and wakeup any waiting to write.
 814          *
 815          * The unp lock is acquired to maintain the validity of the unp_conn
 816          * pointer; no lock on unp2 is required as unp2->unp_socket will be
 817          * static as long as we don't permit unp2 to disconnect from unp,
 818          * which is prevented by the lock on unp.  We cache values from
 819          * so_rcv to avoid holding the so_rcv lock over the entire
 820          * transaction on the remote so_snd.
 821          */
 822         SOCKBUF_LOCK(&so->so_rcv);
 823         mbcnt = so->so_rcv.sb_mbcnt;
 824         sbcc = so->so_rcv.sb_cc;
 825         SOCKBUF_UNLOCK(&so->so_rcv);
 826         /*
 827          * There is a benign race condition at this point.  If we're planning to
 828          * clear SB_STOP, but uipc_send is called on the connected socket at
 829          * this instant, it might add data to the sockbuf and set SB_STOP.  Then
 830          * we would erroneously clear SB_STOP below, even though the sockbuf is
 831          * full.  The race is benign because the only ill effect is to allow the
 832          * sockbuf to exceed its size limit, and the size limits are not
 833          * strictly guaranteed anyway.
 834          */
 835         UNP_PCB_LOCK(unp);
 836         unp2 = unp->unp_conn;
 837         if (unp2 == NULL) {
 838                 UNP_PCB_UNLOCK(unp);
 839                 return (0);
 840         }
 841         so2 = unp2->unp_socket;
 842         SOCKBUF_LOCK(&so2->so_snd);
 843         if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax)
 844                 so2->so_snd.sb_flags &= ~SB_STOP;
 845         sowwakeup_locked(so2);
 846         UNP_PCB_UNLOCK(unp);
 847         return (0);
 848 }
 849
 850 static int
 851 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
 852     struct mbuf *control, struct thread *td)
 853 {
 854         struct unpcb *unp, *unp2;
 855         struct socket *so2;
 856         u_int mbcnt, sbcc;
 857         int error = 0;
 858
 859         unp = sotounpcb(so);
 860         KASSERT(unp != NULL, ("uipc_send: unp == NULL"));
 861
 862         if (flags & PRUS_OOB) {
 863                 error = EOPNOTSUPP;
 864                 goto release;
 865         }
 866         if (control != NULL && (error = unp_internalize(&control, td)))
 867                 goto release;
 868         if ((nam != NULL) || (flags & PRUS_EOF))
 869                 UNP_LINK_WLOCK();
 870         else
 871                 UNP_LINK_RLOCK();
 872         switch (so->so_type) {
 873         case SOCK_DGRAM:
 874         {
 875                 const struct sockaddr *from;
 876
 877                 unp2 = unp->unp_conn;
 878                 if (nam != NULL) {
 879                         UNP_LINK_WLOCK_ASSERT();
 880                         if (unp2 != NULL) {
 881                                 error = EISCONN;
 882                                 break;
 883                         }
 884                         error = unp_connect(so, nam, td);
 885                         if (error)
 886                                 break;
 887                         unp2 = unp->unp_conn;
 888                 }
 889
 890                 /*
 891                  * Because connect() and send() are non-atomic in a sendto()
 892                  * with a target address, it's possible that the socket will
 893                  * have disconnected before the send() can run.  In that case
 894                  * return the slightly counter-intuitive but otherwise
 895                  * correct error that the socket is not connected.
 896                  */
 897                 if (unp2 == NULL) {
 898                         error = ENOTCONN;
 899                         break;
 900                 }
 901                 /* Lockless read. */
 902                 if (unp2->unp_flags & UNP_WANTCRED)
 903                         control = unp_addsockcred(td, control);
 904                 UNP_PCB_LOCK(unp);
 905                 if (unp->unp_addr != NULL)
 906                         from = (struct sockaddr *)unp->unp_addr;
 907                 else
 908                         from = &sun_noname;
 909                 so2 = unp2->unp_socket;
 910                 SOCKBUF_LOCK(&so2->so_rcv);
 911                 if (sbappendaddr_locked(&so2->so_rcv, from, m,
 912                     control)) {
 913                         sorwakeup_locked(so2);
 914                         m = NULL;
 915                         control = NULL;
 916                 } else {
 917                         SOCKBUF_UNLOCK(&so2->so_rcv);
 918                         error = ENOBUFS;
 919                 }
 920                 if (nam != NULL) {
 921                         UNP_LINK_WLOCK_ASSERT();
 922                         UNP_PCB_LOCK(unp2);
 923                         unp_disconnect(unp, unp2);
 924                         UNP_PCB_UNLOCK(unp2);
 925                 }
 926                 UNP_PCB_UNLOCK(unp);
 927                 break;
 928         }
 929
 930         case SOCK_SEQPACKET:
 931         case SOCK_STREAM:
 932                 if ((so->so_state & SS_ISCONNECTED) == 0) {
 933                         if (nam != NULL) {
 934                                 UNP_LINK_WLOCK_ASSERT();
 935                                 error = unp_connect(so, nam, td);
 936                                 if (error)
 937                                         break;  /* XXX */
 938                         } else {
 939                                 error = ENOTCONN;
 940                                 break;
 941                         }
 942                 }
 943
 944                 /* Lockless read. */
 945                 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
 946                         error = EPIPE;
 947                         break;
 948                 }
 949
 950                 /*
 951                  * Because connect() and send() are non-atomic in a sendto()
 952                  * with a target address, it's possible that the socket will
 953                  * have disconnected before the send() can run.  In that case
 954                  * return the slightly counter-intuitive but otherwise
 955                  * correct error that the socket is not connected.
 956                  *
 957                  * Locking here must be done carefully: the linkage lock
 958                  * prevents interconnections between unpcbs from changing, so
 959                  * we can traverse from unp to unp2 without acquiring unp's
 960                  * lock.  Socket buffer locks follow unpcb locks, so we can
 961                  * acquire both remote and lock socket buffer locks.
 962                  */
 963                 unp2 = unp->unp_conn;
 964                 if (unp2 == NULL) {
 965                         error = ENOTCONN;
 966                         break;
 967                 }
 968                 so2 = unp2->unp_socket;
 969                 UNP_PCB_LOCK(unp2);
 970                 SOCKBUF_LOCK(&so2->so_rcv);
 971                 if (unp2->unp_flags & UNP_WANTCRED) {
 972                         /*
 973                          * Credentials are passed only once on SOCK_STREAM
 974                          * and SOCK_SEQPACKET.
 975                          */
 976                         unp2->unp_flags &= ~UNP_WANTCRED;
 977                         control = unp_addsockcred(td, control);
 978                 }
 979                 /*
 980                  * Send to paired receive port, and then reduce send buffer
 981                  * hiwater marks to maintain backpressure.  Wake up readers.
 982                  */
 983                 switch (so->so_type) {
 984                 case SOCK_STREAM:
 985                         if (control != NULL) {
 986                                 if (sbappendcontrol_locked(&so2->so_rcv, m,
 987                                     control))
 988                                         control = NULL;
 989                         } else
 990                                 sbappend_locked(&so2->so_rcv, m);
 991                         break;
 992
 993                 case SOCK_SEQPACKET: {
 994                         const struct sockaddr *from;
 995
 996                         from = &sun_noname;
 997                         /*
 998                          * Don't check for space available in so2->so_rcv.
 999                          * Unix domain sockets only check for space in the
1000                          * sending sockbuf, and that check is performed one
1001                          * level up the stack.
1002                          */
1003                         if (sbappendaddr_nospacecheck_locked(&so2->so_rcv,
1004                                 from, m, control))
1005                                 control = NULL;
1006                         break;
1007                         }
1008                 }
1009
1010                 mbcnt = so2->so_rcv.sb_mbcnt;
1011                 sbcc = so2->so_rcv.sb_cc;
1012                 sorwakeup_locked(so2);
1013
1014                 /*
1015                  * The PCB lock on unp2 protects the SB_STOP flag.  Without it,
1016                  * it would be possible for uipc_rcvd to be called at this
1017                  * point, drain the receiving sockbuf, clear SB_STOP, and then
1018                  * we would set SB_STOP below.  That could lead to an empty
1019                  * sockbuf having SB_STOP set
1020                  */
1021                 SOCKBUF_LOCK(&so->so_snd);
1022                 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax)
1023                         so->so_snd.sb_flags |= SB_STOP;
1024                 SOCKBUF_UNLOCK(&so->so_snd);
1025                 UNP_PCB_UNLOCK(unp2);
1026                 m = NULL;
1027                 break;
1028
1029         default:
1030                 panic("uipc_send unknown socktype");
1031         }
1032
1033         /*
1034          * PRUS_EOF is equivalent to pru_send followed by pru_shutdown.
1035          */
1036         if (flags & PRUS_EOF) {
1037                 UNP_PCB_LOCK(unp);
1038                 socantsendmore(so);
1039                 unp_shutdown(unp);
1040                 UNP_PCB_UNLOCK(unp);
1041         }
1042
1043         if ((nam != NULL) || (flags & PRUS_EOF))
1044                 UNP_LINK_WUNLOCK();
1045         else
1046                 UNP_LINK_RUNLOCK();
1047
1048         if (control != NULL && error != 0)
1049                 unp_dispose(control);
1050
1051 release:
1052         if (control != NULL)
1053                 m_freem(control);
1054         if (m != NULL)
1055                 m_freem(m);
1056         return (error);
1057 }
1058
1059 static int
1060 uipc_sense(struct socket *so, struct stat *sb)
1061 {
1062         struct unpcb *unp;
1063
1064         unp = sotounpcb(so);
1065         KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
1066
1067         sb->st_blksize = so->so_snd.sb_hiwat;
1068         UNP_PCB_LOCK(unp);
1069         sb->st_dev = NODEV;
1070         if (unp->unp_ino == 0)
1071                 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
1072         sb->st_ino = unp->unp_ino;
1073         UNP_PCB_UNLOCK(unp);
1074         return (0);
1075 }
1076
1077 static int
1078 uipc_shutdown(struct socket *so)
1079 {
1080         struct unpcb *unp;
1081
1082         unp = sotounpcb(so);
1083         KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL"));
1084
1085         UNP_LINK_WLOCK();
1086         UNP_PCB_LOCK(unp);
1087         socantsendmore(so);
1088         unp_shutdown(unp);
1089         UNP_PCB_UNLOCK(unp);
1090         UNP_LINK_WUNLOCK();
1091         return (0);
1092 }
1093
1094 static int
1095 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
1096 {
1097         struct unpcb *unp;
1098         const struct sockaddr *sa;
1099
1100         unp = sotounpcb(so);
1101         KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
1102
1103         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1104         UNP_PCB_LOCK(unp);
1105         if (unp->unp_addr != NULL)
1106                 sa = (struct sockaddr *) unp->unp_addr;
1107         else
1108                 sa = &sun_noname;
1109         bcopy(sa, *nam, sa->sa_len);
1110         UNP_PCB_UNLOCK(unp);
1111         return (0);
1112 }
1113
1114 static struct pr_usrreqs uipc_usrreqs_dgram = {
1115         .pru_abort =            uipc_abort,
1116         .pru_accept =           uipc_accept,
1117         .pru_attach =           uipc_attach,
1118         .pru_bind =             uipc_bind,
1119         .pru_bindat =           uipc_bindat,
1120         .pru_connect =          uipc_connect,
1121         .pru_connectat =        uipc_connectat,
1122         .pru_connect2 =         uipc_connect2,
1123         .pru_detach =           uipc_detach,
1124         .pru_disconnect =       uipc_disconnect,
1125         .pru_listen =           uipc_listen,
1126         .pru_peeraddr =         uipc_peeraddr,
1127         .pru_rcvd =             uipc_rcvd,
1128         .pru_send =             uipc_send,
1129         .pru_sense =            uipc_sense,
1130         .pru_shutdown =         uipc_shutdown,
1131         .pru_sockaddr =         uipc_sockaddr,
1132         .pru_soreceive =        soreceive_dgram,
1133         .pru_close =            uipc_close,
1134 };
1135
1136 static struct pr_usrreqs uipc_usrreqs_seqpacket = {
1137         .pru_abort =            uipc_abort,
1138         .pru_accept =           uipc_accept,
1139         .pru_attach =           uipc_attach,
1140         .pru_bind =             uipc_bind,
1141         .pru_bindat =           uipc_bindat,
1142         .pru_connect =          uipc_connect,
1143         .pru_connectat =        uipc_connectat,
1144         .pru_connect2 =         uipc_connect2,
1145         .pru_detach =           uipc_detach,
1146         .pru_disconnect =       uipc_disconnect,
1147         .pru_listen =           uipc_listen,
1148         .pru_peeraddr =         uipc_peeraddr,
1149         .pru_rcvd =             uipc_rcvd,
1150         .pru_send =             uipc_send,
1151         .pru_sense =            uipc_sense,
1152         .pru_shutdown =         uipc_shutdown,
1153         .pru_sockaddr =         uipc_sockaddr,
1154         .pru_soreceive =        soreceive_generic,      /* XXX: or...? */
1155         .pru_close =            uipc_close,
1156 };
1157
1158 static struct pr_usrreqs uipc_usrreqs_stream = {
1159         .pru_abort =            uipc_abort,
1160         .pru_accept =           uipc_accept,
1161         .pru_attach =           uipc_attach,
1162         .pru_bind =             uipc_bind,
1163         .pru_bindat =           uipc_bindat,
1164         .pru_connect =          uipc_connect,
1165         .pru_connectat =        uipc_connectat,
1166         .pru_connect2 =         uipc_connect2,
1167         .pru_detach =           uipc_detach,
1168         .pru_disconnect =       uipc_disconnect,
1169         .pru_listen =           uipc_listen,
1170         .pru_peeraddr =         uipc_peeraddr,
1171         .pru_rcvd =             uipc_rcvd,
1172         .pru_send =             uipc_send,
1173         .pru_sense =            uipc_sense,
1174         .pru_shutdown =         uipc_shutdown,
1175         .pru_sockaddr =         uipc_sockaddr,
1176         .pru_soreceive =        soreceive_generic,
1177         .pru_close =            uipc_close,
1178 };
1179
1180 static int
1181 uipc_ctloutput(struct socket *so, struct sockopt *sopt)
1182 {
1183         struct unpcb *unp;
1184         struct xucred xu;
1185         int error, optval;
1186
1187         if (sopt->sopt_level != 0)
1188                 return (EINVAL);
1189
1190         unp = sotounpcb(so);
1191         KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
1192         error = 0;
1193         switch (sopt->sopt_dir) {
1194         case SOPT_GET:
1195                 switch (sopt->sopt_name) {
1196                 case LOCAL_PEERCRED:
1197                         UNP_PCB_LOCK(unp);
1198                         if (unp->unp_flags & UNP_HAVEPC)
1199                                 xu = unp->unp_peercred;
1200                         else {
1201                                 if (so->so_type == SOCK_STREAM)
1202                                         error = ENOTCONN;
1203                                 else
1204                                         error = EINVAL;
1205                         }
1206                         UNP_PCB_UNLOCK(unp);
1207                         if (error == 0)
1208                                 error = sooptcopyout(sopt, &xu, sizeof(xu));
1209                         break;
1210
1211                 case LOCAL_CREDS:
1212                         /* Unlocked read. */
1213                         optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0;
1214                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1215                         break;
1216
1217                 case LOCAL_CONNWAIT:
1218                         /* Unlocked read. */
1219                         optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0;
1220                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1221                         break;
1222
1223                 default:
1224                         error = EOPNOTSUPP;
1225                         break;
1226                 }
1227                 break;
1228
1229         case SOPT_SET:
1230                 switch (sopt->sopt_name) {
1231                 case LOCAL_CREDS:
1232                 case LOCAL_CONNWAIT:
1233                         error = sooptcopyin(sopt, &optval, sizeof(optval),
1234                                             sizeof(optval));
1235                         if (error)
1236                                 break;
1237
1238 #define OPTSET(bit) do {                                                \
1239         UNP_PCB_LOCK(unp);                                              \
1240         if (optval)                                                     \
1241                 unp->unp_flags |= bit;                                  \
1242         else                                                            \
1243                 unp->unp_flags &= ~bit;                                 \
1244         UNP_PCB_UNLOCK(unp);                                            \
1245 } while (0)
1246
1247                         switch (sopt->sopt_name) {
1248                         case LOCAL_CREDS:
1249                                 OPTSET(UNP_WANTCRED);
1250                                 break;
1251
1252                         case LOCAL_CONNWAIT:
1253                                 OPTSET(UNP_CONNWAIT);
1254                                 break;
1255
1256                         default:
1257                                 break;
1258                         }
1259                         break;
1260 #undef  OPTSET
1261                 default:
1262                         error = ENOPROTOOPT;
1263                         break;
1264                 }
1265                 break;
1266
1267         default:
1268                 error = EOPNOTSUPP;
1269                 break;
1270         }
1271         return (error);
1272 }
1273
1274 static int
1275 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1276 {
1277
1278         return (unp_connectat(AT_FDCWD, so, nam, td));
1279 }
1280
1281 static int
1282 unp_connectat(int fd, struct socket *so, struct sockaddr *nam,
1283     struct thread *td)
1284 {
1285         struct sockaddr_un *soun = (struct sockaddr_un *)nam;
1286         struct vnode *vp;
1287         struct socket *so2, *so3;
1288         struct unpcb *unp, *unp2, *unp3;
1289         struct nameidata nd;
1290         char buf[SOCK_MAXADDRLEN];
1291         struct sockaddr *sa;
1292         cap_rights_t rights;
1293         int error, len;
1294
1295         if (nam->sa_family != AF_UNIX)
1296                 return (EAFNOSUPPORT);
1297
1298         UNP_LINK_WLOCK_ASSERT();
1299
1300         unp = sotounpcb(so);
1301         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1302
1303         if (nam->sa_len > sizeof(struct sockaddr_un))
1304                 return (EINVAL);
1305         len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
1306         if (len <= 0)
1307                 return (EINVAL);
1308         bcopy(soun->sun_path, buf, len);
1309         buf[len] = 0;
1310
1311         UNP_PCB_LOCK(unp);
1312         if (unp->unp_flags & UNP_CONNECTING) {
1313                 UNP_PCB_UNLOCK(unp);
1314                 return (EALREADY);
1315         }
1316         UNP_LINK_WUNLOCK();
1317         unp->unp_flags |= UNP_CONNECTING;
1318         UNP_PCB_UNLOCK(unp);
1319
1320         sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1321         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
1322             UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td);
1323         error = namei(&nd);
1324         if (error)
1325                 vp = NULL;
1326         else
1327                 vp = nd.ni_vp;
1328         ASSERT_VOP_LOCKED(vp, "unp_connect");
1329         NDFREE(&nd, NDF_ONLY_PNBUF);
1330         if (error)
1331                 goto bad;
1332
1333         if (vp->v_type != VSOCK) {
1334                 error = ENOTSOCK;
1335                 goto bad;
1336         }
1337 #ifdef MAC
1338         error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
1339         if (error)
1340                 goto bad;
1341 #endif
1342         error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
1343         if (error)
1344                 goto bad;
1345
1346         unp = sotounpcb(so);
1347         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1348
1349         /*
1350          * Lock linkage lock for two reasons: make sure v_socket is stable,
1351          * and to protect simultaneous locking of multiple pcbs.
1352          */
1353         UNP_LINK_WLOCK();
1354         VOP_UNP_CONNECT(vp, &so2);
1355         if (so2 == NULL) {
1356                 error = ECONNREFUSED;
1357                 goto bad2;
1358         }
1359         if (so->so_type != so2->so_type) {
1360                 error = EPROTOTYPE;
1361                 goto bad2;
1362         }
1363         if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
1364                 if (so2->so_options & SO_ACCEPTCONN) {
1365                         CURVNET_SET(so2->so_vnet);
1366                         so3 = sonewconn(so2, 0);
1367                         CURVNET_RESTORE();
1368                 } else
1369                         so3 = NULL;
1370                 if (so3 == NULL) {
1371                         error = ECONNREFUSED;
1372                         goto bad2;
1373                 }
1374                 unp = sotounpcb(so);
1375                 unp2 = sotounpcb(so2);
1376                 unp3 = sotounpcb(so3);
1377                 UNP_PCB_LOCK(unp);
1378                 UNP_PCB_LOCK(unp2);
1379                 UNP_PCB_LOCK(unp3);
1380                 if (unp2->unp_addr != NULL) {
1381                         bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
1382                         unp3->unp_addr = (struct sockaddr_un *) sa;
1383                         sa = NULL;
1384                 }
1385
1386                 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
1387                     ("unp_connect: listener without cached peercred"));
1388                 unp_copy_peercred(td, unp3, unp, unp2);
1389
1390                 UNP_PCB_UNLOCK(unp3);
1391                 UNP_PCB_UNLOCK(unp2);
1392                 UNP_PCB_UNLOCK(unp);
1393 #ifdef MAC
1394                 mac_socketpeer_set_from_socket(so, so3);
1395                 mac_socketpeer_set_from_socket(so3, so);
1396 #endif
1397
1398                 so2 = so3;
1399         }
1400         unp = sotounpcb(so);
1401         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1402         unp2 = sotounpcb(so2);
1403         KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL"));
1404         UNP_PCB_LOCK(unp);
1405         UNP_PCB_LOCK(unp2);
1406         error = unp_connect2(so, so2, PRU_CONNECT);
1407         UNP_PCB_UNLOCK(unp2);
1408         UNP_PCB_UNLOCK(unp);
1409 bad2:
1410         UNP_LINK_WUNLOCK();
1411 bad:
1412         if (vp != NULL)
1413                 vput(vp);
1414         free(sa, M_SONAME);
1415         UNP_LINK_WLOCK();
1416         UNP_PCB_LOCK(unp);
1417         unp->unp_flags &= ~UNP_CONNECTING;
1418         UNP_PCB_UNLOCK(unp);
1419         return (error);
1420 }
1421
1422 /*
1423  * Set socket peer credentials at connection time.
1424  *
1425  * The client's PCB credentials are copied from its process structure.  The
1426  * server's PCB credentials are copied from the socket on which it called
1427  * listen(2).  uipc_listen cached that process's credentials at the time.
1428  */
1429 void
1430 unp_copy_peercred(struct thread *td, struct unpcb *client_unp,
1431     struct unpcb *server_unp, struct unpcb *listen_unp)
1432 {
1433         cru2x(td->td_ucred, &client_unp->unp_peercred);
1434         client_unp->unp_flags |= UNP_HAVEPC;
1435
1436         memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred,
1437             sizeof(server_unp->unp_peercred));
1438         server_unp->unp_flags |= UNP_HAVEPC;
1439         if (listen_unp->unp_flags & UNP_WANTCRED)
1440                 client_unp->unp_flags |= UNP_WANTCRED;
1441 }
1442
1443 static int
1444 unp_connect2(struct socket *so, struct socket *so2, int req)
1445 {
1446         struct unpcb *unp;
1447         struct unpcb *unp2;
1448
1449         unp = sotounpcb(so);
1450         KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
1451         unp2 = sotounpcb(so2);
1452         KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
1453
1454         UNP_LINK_WLOCK_ASSERT();
1455         UNP_PCB_LOCK_ASSERT(unp);
1456         UNP_PCB_LOCK_ASSERT(unp2);
1457
1458         if (so2->so_type != so->so_type)
1459                 return (EPROTOTYPE);
1460         unp2->unp_flags &= ~UNP_NASCENT;
1461         unp->unp_conn = unp2;
1462
1463         switch (so->so_type) {
1464         case SOCK_DGRAM:
1465                 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
1466                 soisconnected(so);
1467                 break;
1468
1469         case SOCK_STREAM:
1470         case SOCK_SEQPACKET:
1471                 unp2->unp_conn = unp;
1472                 if (req == PRU_CONNECT &&
1473                     ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
1474                         soisconnecting(so);
1475                 else
1476                         soisconnected(so);
1477                 soisconnected(so2);
1478                 break;
1479
1480         default:
1481                 panic("unp_connect2");
1482         }
1483         return (0);
1484 }
1485
1486 static void
1487 unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
1488 {
1489         struct socket *so;
1490
1491         KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL"));
1492
1493         UNP_LINK_WLOCK_ASSERT();
1494         UNP_PCB_LOCK_ASSERT(unp);
1495         UNP_PCB_LOCK_ASSERT(unp2);
1496
1497         unp->unp_conn = NULL;
1498         switch (unp->unp_socket->so_type) {
1499         case SOCK_DGRAM:
1500                 LIST_REMOVE(unp, unp_reflink);
1501                 so = unp->unp_socket;
1502                 SOCK_LOCK(so);
1503                 so->so_state &= ~SS_ISCONNECTED;
1504                 SOCK_UNLOCK(so);
1505                 break;
1506
1507         case SOCK_STREAM:
1508         case SOCK_SEQPACKET:
1509                 soisdisconnected(unp->unp_socket);
1510                 unp2->unp_conn = NULL;
1511                 soisdisconnected(unp2->unp_socket);
1512                 break;
1513         }
1514 }
1515
1516 /*
1517  * unp_pcblist() walks the global list of struct unpcb's to generate a
1518  * pointer list, bumping the refcount on each unpcb.  It then copies them out
1519  * sequentially, validating the generation number on each to see if it has
1520  * been detached.  All of this is necessary because copyout() may sleep on
1521  * disk I/O.
1522  */
1523 static int
1524 unp_pcblist(SYSCTL_HANDLER_ARGS)
1525 {
1526         int error, i, n;
1527         int freeunp;
1528         struct unpcb *unp, **unp_list;
1529         unp_gen_t gencnt;
1530         struct xunpgen *xug;
1531         struct unp_head *head;
1532         struct xunpcb *xu;
1533
1534         switch ((intptr_t)arg1) {
1535         case SOCK_STREAM:
1536                 head = &unp_shead;
1537                 break;
1538
1539         case SOCK_DGRAM:
1540                 head = &unp_dhead;
1541                 break;
1542
1543         case SOCK_SEQPACKET:
1544                 head = &unp_sphead;
1545                 break;
1546
1547         default:
1548                 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1);
1549         }
1550
1551         /*
1552          * The process of preparing the PCB list is too time-consuming and
1553          * resource-intensive to repeat twice on every request.
1554          */
1555         if (req->oldptr == NULL) {
1556                 n = unp_count;
1557                 req->oldidx = 2 * (sizeof *xug)
1558                         + (n + n/8) * sizeof(struct xunpcb);
1559                 return (0);
1560         }
1561
1562         if (req->newptr != NULL)
1563                 return (EPERM);
1564
1565         /*
1566          * OK, now we're committed to doing something.
1567          */
1568         xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK);
1569         UNP_LIST_LOCK();
1570         gencnt = unp_gencnt;
1571         n = unp_count;
1572         UNP_LIST_UNLOCK();
1573
1574         xug->xug_len = sizeof *xug;
1575         xug->xug_count = n;
1576         xug->xug_gen = gencnt;
1577         xug->xug_sogen = so_gencnt;
1578         error = SYSCTL_OUT(req, xug, sizeof *xug);
1579         if (error) {
1580                 free(xug, M_TEMP);
1581                 return (error);
1582         }
1583
1584         unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
1585
1586         UNP_LIST_LOCK();
1587         for (unp = LIST_FIRST(head), i = 0; unp && i < n;
1588              unp = LIST_NEXT(unp, unp_link)) {
1589                 UNP_PCB_LOCK(unp);
1590                 if (unp->unp_gencnt <= gencnt) {
1591                         if (cr_cansee(req->td->td_ucred,
1592                             unp->unp_socket->so_cred)) {
1593                                 UNP_PCB_UNLOCK(unp);
1594                                 continue;
1595                         }
1596                         unp_list[i++] = unp;
1597                         unp->unp_refcount++;
1598                 }
1599                 UNP_PCB_UNLOCK(unp);
1600         }
1601         UNP_LIST_UNLOCK();
1602         n = i;                  /* In case we lost some during malloc. */
1603
1604         error = 0;
1605         xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
1606         for (i = 0; i < n; i++) {
1607                 unp = unp_list[i];
1608                 UNP_PCB_LOCK(unp);
1609                 unp->unp_refcount--;
1610                 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) {
1611                         xu->xu_len = sizeof *xu;
1612                         xu->xu_unpp = unp;
1613                         /*
1614                          * XXX - need more locking here to protect against
1615                          * connect/disconnect races for SMP.
1616                          */
1617                         if (unp->unp_addr != NULL)
1618                                 bcopy(unp->unp_addr, &xu->xu_addr,
1619                                       unp->unp_addr->sun_len);
1620                         if (unp->unp_conn != NULL &&
1621                             unp->unp_conn->unp_addr != NULL)
1622                                 bcopy(unp->unp_conn->unp_addr,
1623                                       &xu->xu_caddr,
1624                                       unp->unp_conn->unp_addr->sun_len);
1625                         bcopy(unp, &xu->xu_unp, sizeof *unp);
1626                         sotoxsocket(unp->unp_socket, &xu->xu_socket);
1627                         UNP_PCB_UNLOCK(unp);
1628                         error = SYSCTL_OUT(req, xu, sizeof *xu);
1629                 } else {
1630                         freeunp = (unp->unp_refcount == 0);
1631                         UNP_PCB_UNLOCK(unp);
1632                         if (freeunp) {
1633                                 UNP_PCB_LOCK_DESTROY(unp);
1634                                 uma_zfree(unp_zone, unp);
1635                         }
1636                 }
1637         }
1638         free(xu, M_TEMP);
1639         if (!error) {
1640                 /*
1641                  * Give the user an updated idea of our state.  If the
1642                  * generation differs from what we told her before, she knows
1643                  * that something happened while we were processing this
1644                  * request, and it might be necessary to retry.
1645                  */
1646                 xug->xug_gen = unp_gencnt;
1647                 xug->xug_sogen = so_gencnt;
1648                 xug->xug_count = unp_count;
1649                 error = SYSCTL_OUT(req, xug, sizeof *xug);
1650         }
1651         free(unp_list, M_TEMP);
1652         free(xug, M_TEMP);
1653         return (error);
1654 }
1655
1656 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
1657     (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
1658     "List of active local datagram sockets");
1659 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
1660     (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
1661     "List of active local stream sockets");
1662 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist,
1663     CTLTYPE_OPAQUE | CTLFLAG_RD,
1664     (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb",
1665     "List of active local seqpacket sockets");
1666
1667 static void
1668 unp_shutdown(struct unpcb *unp)
1669 {
1670         struct unpcb *unp2;
1671         struct socket *so;
1672
1673         UNP_LINK_WLOCK_ASSERT();
1674         UNP_PCB_LOCK_ASSERT(unp);
1675
1676         unp2 = unp->unp_conn;
1677         if ((unp->unp_socket->so_type == SOCK_STREAM ||
1678             (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) {
1679                 so = unp2->unp_socket;
1680                 if (so != NULL)
1681                         socantrcvmore(so);
1682         }
1683 }
1684
1685 static void
1686 unp_drop(struct unpcb *unp, int errno)
1687 {
1688         struct socket *so = unp->unp_socket;
1689         struct unpcb *unp2;
1690
1691         UNP_LINK_WLOCK_ASSERT();
1692         UNP_PCB_LOCK_ASSERT(unp);
1693
1694         so->so_error = errno;
1695         unp2 = unp->unp_conn;
1696         if (unp2 == NULL)
1697                 return;
1698         UNP_PCB_LOCK(unp2);
1699         unp_disconnect(unp, unp2);
1700         UNP_PCB_UNLOCK(unp2);
1701 }
1702
1703 static void
1704 unp_freerights(struct filedescent **fdep, int fdcount)
1705 {
1706         struct file *fp;
1707         int i;
1708
1709         KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount));
1710
1711         for (i = 0; i < fdcount; i++) {
1712                 fp = fdep[i]->fde_file;
1713                 filecaps_free(&fdep[i]->fde_caps);
1714                 unp_discard(fp);
1715         }
1716         free(fdep[0], M_FILECAPS);
1717 }
1718
1719 static int
1720 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
1721 {
1722         struct thread *td = curthread;          /* XXX */
1723         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1724         int i;
1725         int *fdp;
1726         struct filedesc *fdesc = td->td_proc->p_fd;
1727         struct filedescent *fde, **fdep;
1728         void *data;
1729         socklen_t clen = control->m_len, datalen;
1730         int error, newfds;
1731         u_int newlen;
1732
1733         UNP_LINK_UNLOCK_ASSERT();
1734
1735         error = 0;
1736         if (controlp != NULL) /* controlp == NULL => free control messages */
1737                 *controlp = NULL;
1738         while (cm != NULL) {
1739                 if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
1740                         error = EINVAL;
1741                         break;
1742                 }
1743                 data = CMSG_DATA(cm);
1744                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1745                 if (cm->cmsg_level == SOL_SOCKET
1746                     && cm->cmsg_type == SCM_RIGHTS) {
1747                         newfds = datalen / sizeof(*fdep);
1748                         if (newfds == 0)
1749                                 goto next;
1750                         fdep = data;
1751
1752                         /* If we're not outputting the descriptors free them. */
1753                         if (error || controlp == NULL) {
1754                                 unp_freerights(fdep, newfds);
1755                                 goto next;
1756                         }
1757                         FILEDESC_XLOCK(fdesc);
1758
1759                         /*
1760                          * Now change each pointer to an fd in the global
1761                          * table to an integer that is the index to the local
1762                          * fd table entry that we set up to point to the
1763                          * global one we are transferring.
1764                          */
1765                         newlen = newfds * sizeof(int);
1766                         *controlp = sbcreatecontrol(NULL, newlen,
1767                             SCM_RIGHTS, SOL_SOCKET);
1768                         if (*controlp == NULL) {
1769                                 FILEDESC_XUNLOCK(fdesc);
1770                                 error = E2BIG;
1771                                 unp_freerights(fdep, newfds);
1772                                 goto next;
1773                         }
1774
1775                         fdp = (int *)
1776                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1777                         if (fdallocn(td, 0, fdp, newfds) != 0) {
1778                                 FILEDESC_XUNLOCK(td->td_proc->p_fd);
1779                                 error = EMSGSIZE;
1780                                 unp_freerights(fdep, newfds);
1781                                 m_freem(*controlp);
1782                                 *controlp = NULL;
1783                                 goto next;
1784                         }
1785                         for (i = 0; i < newfds; i++, fdp++) {
1786                                 fde = &fdesc->fd_ofiles[*fdp];
1787                                 fde->fde_file = fdep[i]->fde_file;
1788                                 filecaps_move(&fdep[i]->fde_caps,
1789                                     &fde->fde_caps);
1790                                 if ((flags & MSG_CMSG_CLOEXEC) != 0)
1791                                         fde->fde_flags |= UF_EXCLOSE;
1792                                 unp_externalize_fp(fde->fde_file);
1793                         }
1794                         FILEDESC_XUNLOCK(fdesc);
1795                         free(fdep[0], M_FILECAPS);
1796                 } else {
1797                         /* We can just copy anything else across. */
1798                         if (error || controlp == NULL)
1799                                 goto next;
1800                         *controlp = sbcreatecontrol(NULL, datalen,
1801                             cm->cmsg_type, cm->cmsg_level);
1802                         if (*controlp == NULL) {
1803                                 error = ENOBUFS;
1804                                 goto next;
1805                         }
1806                         bcopy(data,
1807                             CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
1808                             datalen);
1809                 }
1810                 controlp = &(*controlp)->m_next;
1811
1812 next:
1813                 if (CMSG_SPACE(datalen) < clen) {
1814                         clen -= CMSG_SPACE(datalen);
1815                         cm = (struct cmsghdr *)
1816                             ((caddr_t)cm + CMSG_SPACE(datalen));
1817                 } else {
1818                         clen = 0;
1819                         cm = NULL;
1820                 }
1821         }
1822
1823         m_freem(control);
1824         return (error);
1825 }
1826
1827 static void
1828 unp_zone_change(void *tag)
1829 {
1830
1831         uma_zone_set_max(unp_zone, maxsockets);
1832 }
1833
1834 static void
1835 unp_init(void)
1836 {
1837
1838 #ifdef VIMAGE
1839         if (!IS_DEFAULT_VNET(curvnet))
1840                 return;
1841 #endif
1842         unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL,
1843             NULL, NULL, UMA_ALIGN_PTR, 0);
1844         if (unp_zone == NULL)
1845                 panic("unp_init");
1846         uma_zone_set_max(unp_zone, maxsockets);
1847         uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached");
1848         EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
1849             NULL, EVENTHANDLER_PRI_ANY);
1850         LIST_INIT(&unp_dhead);
1851         LIST_INIT(&unp_shead);
1852         LIST_INIT(&unp_sphead);
1853         SLIST_INIT(&unp_defers);
1854         TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL);
1855         TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL);
1856         UNP_LINK_LOCK_INIT();
1857         UNP_LIST_LOCK_INIT();
1858         UNP_DEFERRED_LOCK_INIT();
1859 }
1860
1861 static int
1862 unp_internalize(struct mbuf **controlp, struct thread *td)
1863 {
1864         struct mbuf *control = *controlp;
1865         struct proc *p = td->td_proc;
1866         struct filedesc *fdesc = p->p_fd;
1867         struct bintime *bt;
1868         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1869         struct cmsgcred *cmcred;
1870         struct filedescent *fde, **fdep, *fdev;
1871         struct file *fp;
1872         struct timeval *tv;
1873         int i, *fdp;
1874         void *data;
1875         socklen_t clen = control->m_len, datalen;
1876         int error, oldfds;
1877         u_int newlen;
1878
1879         UNP_LINK_UNLOCK_ASSERT();
1880
1881         error = 0;
1882         *controlp = NULL;
1883         while (cm != NULL) {
1884                 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET
1885                     || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) {
1886                         error = EINVAL;
1887                         goto out;
1888                 }
1889                 data = CMSG_DATA(cm);
1890                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1891
1892                 switch (cm->cmsg_type) {
1893                 /*
1894                  * Fill in credential information.
1895                  */
1896                 case SCM_CREDS:
1897                         *controlp = sbcreatecontrol(NULL, sizeof(*cmcred),
1898                             SCM_CREDS, SOL_SOCKET);
1899                         if (*controlp == NULL) {
1900                                 error = ENOBUFS;
1901                                 goto out;
1902                         }
1903                         cmcred = (struct cmsgcred *)
1904                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1905                         cmcred->cmcred_pid = p->p_pid;
1906                         cmcred->cmcred_uid = td->td_ucred->cr_ruid;
1907                         cmcred->cmcred_gid = td->td_ucred->cr_rgid;
1908                         cmcred->cmcred_euid = td->td_ucred->cr_uid;
1909                         cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups,
1910                             CMGROUP_MAX);
1911                         for (i = 0; i < cmcred->cmcred_ngroups; i++)
1912                                 cmcred->cmcred_groups[i] =
1913                                     td->td_ucred->cr_groups[i];
1914                         break;
1915
1916                 case SCM_RIGHTS:
1917                         oldfds = datalen / sizeof (int);
1918                         if (oldfds == 0)
1919                                 break;
1920                         /*
1921                          * Check that all the FDs passed in refer to legal
1922                          * files.  If not, reject the entire operation.
1923                          */
1924                         fdp = data;
1925                         FILEDESC_SLOCK(fdesc);
1926                         for (i = 0; i < oldfds; i++, fdp++) {
1927                                 fp = fget_locked(fdesc, *fdp);
1928                                 if (fp == NULL) {
1929                                         FILEDESC_SUNLOCK(fdesc);
1930                                         error = EBADF;
1931                                         goto out;
1932                                 }
1933                                 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
1934                                         FILEDESC_SUNLOCK(fdesc);
1935                                         error = EOPNOTSUPP;
1936                                         goto out;
1937                                 }
1938
1939                         }
1940
1941                         /*
1942                          * Now replace the integer FDs with pointers to the
1943                          * file structure and capability rights.
1944                          */
1945                         newlen = oldfds * sizeof(fdep[0]);
1946                         *controlp = sbcreatecontrol(NULL, newlen,
1947                             SCM_RIGHTS, SOL_SOCKET);
1948                         if (*controlp == NULL) {
1949                                 FILEDESC_SUNLOCK(fdesc);
1950                                 error = E2BIG;
1951                                 goto out;
1952                         }
1953                         fdp = data;
1954                         fdep = (struct filedescent **)
1955                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1956                         fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS,
1957                             M_WAITOK);
1958                         for (i = 0; i < oldfds; i++, fdev++, fdp++) {
1959                                 fde = &fdesc->fd_ofiles[*fdp];
1960                                 fdep[i] = fdev;
1961                                 fdep[i]->fde_file = fde->fde_file;
1962                                 filecaps_copy(&fde->fde_caps,
1963                                     &fdep[i]->fde_caps);
1964                                 unp_internalize_fp(fdep[i]->fde_file);
1965                         }
1966                         FILEDESC_SUNLOCK(fdesc);
1967                         break;
1968
1969                 case SCM_TIMESTAMP:
1970                         *controlp = sbcreatecontrol(NULL, sizeof(*tv),
1971                             SCM_TIMESTAMP, SOL_SOCKET);
1972                         if (*controlp == NULL) {
1973                                 error = ENOBUFS;
1974                                 goto out;
1975                         }
1976                         tv = (struct timeval *)
1977                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1978                         microtime(tv);
1979                         break;
1980
1981                 case SCM_BINTIME:
1982                         *controlp = sbcreatecontrol(NULL, sizeof(*bt),
1983                             SCM_BINTIME, SOL_SOCKET);
1984                         if (*controlp == NULL) {
1985                                 error = ENOBUFS;
1986                                 goto out;
1987                         }
1988                         bt = (struct bintime *)
1989                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1990                         bintime(bt);
1991                         break;
1992
1993                 default:
1994                         error = EINVAL;
1995                         goto out;
1996                 }
1997
1998                 controlp = &(*controlp)->m_next;
1999                 if (CMSG_SPACE(datalen) < clen) {
2000                         clen -= CMSG_SPACE(datalen);
2001                         cm = (struct cmsghdr *)
2002                             ((caddr_t)cm + CMSG_SPACE(datalen));
2003                 } else {
2004                         clen = 0;
2005                         cm = NULL;
2006                 }
2007         }
2008
2009 out:
2010         m_freem(control);
2011         return (error);
2012 }
2013
2014 static struct mbuf *
2015 unp_addsockcred(struct thread *td, struct mbuf *control)
2016 {
2017         struct mbuf *m, *n, *n_prev;
2018         struct sockcred *sc;
2019         const struct cmsghdr *cm;
2020         int ngroups;
2021         int i;
2022
2023         ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
2024         m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET);
2025         if (m == NULL)
2026                 return (control);
2027
2028         sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *));
2029         sc->sc_uid = td->td_ucred->cr_ruid;
2030         sc->sc_euid = td->td_ucred->cr_uid;
2031         sc->sc_gid = td->td_ucred->cr_rgid;
2032         sc->sc_egid = td->td_ucred->cr_gid;
2033         sc->sc_ngroups = ngroups;
2034         for (i = 0; i < sc->sc_ngroups; i++)
2035                 sc->sc_groups[i] = td->td_ucred->cr_groups[i];
2036
2037         /*
2038          * Unlink SCM_CREDS control messages (struct cmsgcred), since just
2039          * created SCM_CREDS control message (struct sockcred) has another
2040          * format.
2041          */
2042         if (control != NULL)
2043                 for (n = control, n_prev = NULL; n != NULL;) {
2044                         cm = mtod(n, struct cmsghdr *);
2045                         if (cm->cmsg_level == SOL_SOCKET &&
2046                             cm->cmsg_type == SCM_CREDS) {
2047                                 if (n_prev == NULL)
2048                                         control = n->m_next;
2049                                 else
2050                                         n_prev->m_next = n->m_next;
2051                                 n = m_free(n);
2052                         } else {
2053                                 n_prev = n;
2054                                 n = n->m_next;
2055                         }
2056                 }
2057
2058         /* Prepend it to the head. */
2059         m->m_next = control;
2060         return (m);
2061 }
2062
2063 static struct unpcb *
2064 fptounp(struct file *fp)
2065 {
2066         struct socket *so;
2067
2068         if (fp->f_type != DTYPE_SOCKET)
2069                 return (NULL);
2070         if ((so = fp->f_data) == NULL)
2071                 return (NULL);
2072         if (so->so_proto->pr_domain != &localdomain)
2073                 return (NULL);
2074         return sotounpcb(so);
2075 }
2076
2077 static void
2078 unp_discard(struct file *fp)
2079 {
2080         struct unp_defer *dr;
2081
2082         if (unp_externalize_fp(fp)) {
2083                 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK);
2084                 dr->ud_fp = fp;
2085                 UNP_DEFERRED_LOCK();
2086                 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link);
2087                 UNP_DEFERRED_UNLOCK();
2088                 atomic_add_int(&unp_defers_count, 1);
2089                 taskqueue_enqueue(taskqueue_thread, &unp_defer_task);
2090         } else
2091                 (void) closef(fp, (struct thread *)NULL);
2092 }
2093
2094 static void
2095 unp_process_defers(void *arg __unused, int pending)
2096 {
2097         struct unp_defer *dr;
2098         SLIST_HEAD(, unp_defer) drl;
2099         int count;
2100
2101         SLIST_INIT(&drl);
2102         for (;;) {
2103                 UNP_DEFERRED_LOCK();
2104                 if (SLIST_FIRST(&unp_defers) == NULL) {
2105                         UNP_DEFERRED_UNLOCK();
2106                         break;
2107                 }
2108                 SLIST_SWAP(&unp_defers, &drl, unp_defer);
2109                 UNP_DEFERRED_UNLOCK();
2110                 count = 0;
2111                 while ((dr = SLIST_FIRST(&drl)) != NULL) {
2112                         SLIST_REMOVE_HEAD(&drl, ud_link);
2113                         closef(dr->ud_fp, NULL);
2114                         free(dr, M_TEMP);
2115                         count++;
2116                 }
2117                 atomic_add_int(&unp_defers_count, -count);
2118         }
2119 }
2120
2121 static void
2122 unp_internalize_fp(struct file *fp)
2123 {
2124         struct unpcb *unp;
2125
2126         UNP_LINK_WLOCK();
2127         if ((unp = fptounp(fp)) != NULL) {
2128                 unp->unp_file = fp;
2129                 unp->unp_msgcount++;
2130         }
2131         fhold(fp);
2132         unp_rights++;
2133         UNP_LINK_WUNLOCK();
2134 }
2135
2136 static int
2137 unp_externalize_fp(struct file *fp)
2138 {
2139         struct unpcb *unp;
2140         int ret;
2141
2142         UNP_LINK_WLOCK();
2143         if ((unp = fptounp(fp)) != NULL) {
2144                 unp->unp_msgcount--;
2145                 ret = 1;
2146         } else
2147                 ret = 0;
2148         unp_rights--;
2149         UNP_LINK_WUNLOCK();
2150         return (ret);
2151 }
2152
2153 /*
2154  * unp_defer indicates whether additional work has been defered for a future
2155  * pass through unp_gc().  It is thread local and does not require explicit
2156  * synchronization.
2157  */
2158 static int      unp_marked;
2159 static int      unp_unreachable;
2160
2161 static void
2162 unp_accessable(struct filedescent **fdep, int fdcount)
2163 {
2164         struct unpcb *unp;
2165         struct file *fp;
2166         int i;
2167
2168         for (i = 0; i < fdcount; i++) {
2169                 fp = fdep[i]->fde_file;
2170                 if ((unp = fptounp(fp)) == NULL)
2171                         continue;
2172                 if (unp->unp_gcflag & UNPGC_REF)
2173                         continue;
2174                 unp->unp_gcflag &= ~UNPGC_DEAD;
2175                 unp->unp_gcflag |= UNPGC_REF;
2176                 unp_marked++;
2177         }
2178 }
2179
2180 static void
2181 unp_gc_process(struct unpcb *unp)
2182 {
2183         struct socket *soa;
2184         struct socket *so;
2185         struct file *fp;
2186
2187         /* Already processed. */
2188         if (unp->unp_gcflag & UNPGC_SCANNED)
2189                 return;
2190         fp = unp->unp_file;
2191
2192         /*
2193          * Check for a socket potentially in a cycle.  It must be in a
2194          * queue as indicated by msgcount, and this must equal the file
2195          * reference count.  Note that when msgcount is 0 the file is NULL.
2196          */
2197         if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp &&
2198             unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) {
2199                 unp->unp_gcflag |= UNPGC_DEAD;
2200                 unp_unreachable++;
2201                 return;
2202         }
2203
2204         /*
2205          * Mark all sockets we reference with RIGHTS.
2206          */
2207         so = unp->unp_socket;
2208         if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) {
2209                 SOCKBUF_LOCK(&so->so_rcv);
2210                 unp_scan(so->so_rcv.sb_mb, unp_accessable);
2211                 SOCKBUF_UNLOCK(&so->so_rcv);
2212         }
2213
2214         /*
2215          * Mark all sockets in our accept queue.
2216          */
2217         ACCEPT_LOCK();
2218         TAILQ_FOREACH(soa, &so->so_comp, so_list) {
2219                 if ((sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) != 0)
2220                         continue;
2221                 SOCKBUF_LOCK(&soa->so_rcv);
2222                 unp_scan(soa->so_rcv.sb_mb, unp_accessable);
2223                 SOCKBUF_UNLOCK(&soa->so_rcv);
2224         }
2225         ACCEPT_UNLOCK();
2226         unp->unp_gcflag |= UNPGC_SCANNED;
2227 }
2228
2229 static int unp_recycled;
2230 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0,
2231     "Number of unreachable sockets claimed by the garbage collector.");
2232
2233 static int unp_taskcount;
2234 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0,
2235     "Number of times the garbage collector has run.");
2236
2237 static void
2238 unp_gc(__unused void *arg, int pending)
2239 {
2240         struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead,
2241                                     NULL };
2242         struct unp_head **head;
2243         struct file *f, **unref;
2244         struct unpcb *unp;
2245         int i, total;
2246
2247         unp_taskcount++;
2248         UNP_LIST_LOCK();
2249         /*
2250          * First clear all gc flags from previous runs, apart from
2251          * UNPGC_IGNORE_RIGHTS.
2252          */
2253         for (head = heads; *head != NULL; head++)
2254                 LIST_FOREACH(unp, *head, unp_link)
2255                         unp->unp_gcflag =
2256                             (unp->unp_gcflag & UNPGC_IGNORE_RIGHTS);
2257
2258         /*
2259          * Scan marking all reachable sockets with UNPGC_REF.  Once a socket
2260          * is reachable all of the sockets it references are reachable.
2261          * Stop the scan once we do a complete loop without discovering
2262          * a new reachable socket.
2263          */
2264         do {
2265                 unp_unreachable = 0;
2266                 unp_marked = 0;
2267                 for (head = heads; *head != NULL; head++)
2268                         LIST_FOREACH(unp, *head, unp_link)
2269                                 unp_gc_process(unp);
2270         } while (unp_marked);
2271         UNP_LIST_UNLOCK();
2272         if (unp_unreachable == 0)
2273                 return;
2274
2275         /*
2276          * Allocate space for a local list of dead unpcbs.
2277          */
2278         unref = malloc(unp_unreachable * sizeof(struct file *),
2279             M_TEMP, M_WAITOK);
2280
2281         /*
2282          * Iterate looking for sockets which have been specifically marked
2283          * as as unreachable and store them locally.
2284          */
2285         UNP_LINK_RLOCK();
2286         UNP_LIST_LOCK();
2287         for (total = 0, head = heads; *head != NULL; head++)
2288                 LIST_FOREACH(unp, *head, unp_link)
2289                         if ((unp->unp_gcflag & UNPGC_DEAD) != 0) {
2290                                 f = unp->unp_file;
2291                                 if (unp->unp_msgcount == 0 || f == NULL ||
2292                                     f->f_count != unp->unp_msgcount)
2293                                         continue;
2294                                 unref[total++] = f;
2295                                 fhold(f);
2296                                 KASSERT(total <= unp_unreachable,
2297                                     ("unp_gc: incorrect unreachable count."));
2298                         }
2299         UNP_LIST_UNLOCK();
2300         UNP_LINK_RUNLOCK();
2301
2302         /*
2303          * Now flush all sockets, free'ing rights.  This will free the
2304          * struct files associated with these sockets but leave each socket
2305          * with one remaining ref.
2306          */
2307         for (i = 0; i < total; i++) {
2308                 struct socket *so;
2309
2310                 so = unref[i]->f_data;
2311                 CURVNET_SET(so->so_vnet);
2312                 sorflush(so);
2313                 CURVNET_RESTORE();
2314         }
2315
2316         /*
2317          * And finally release the sockets so they can be reclaimed.
2318          */
2319         for (i = 0; i < total; i++)
2320                 fdrop(unref[i], NULL);
2321         unp_recycled += total;
2322         free(unref, M_TEMP);
2323 }
2324
2325 static void
2326 unp_dispose(struct mbuf *m)
2327 {
2328
2329         if (m)
2330                 unp_scan(m, unp_freerights);
2331 }
2332
2333 /*
2334  * Synchronize against unp_gc, which can trip over data as we are freeing it.
2335  */
2336 void
2337 unp_dispose_so(struct socket *so)
2338 {
2339         struct unpcb *unp;
2340
2341         unp = sotounpcb(so);
2342         UNP_LIST_LOCK();
2343         unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS;
2344         UNP_LIST_UNLOCK();
2345         unp_dispose(so->so_rcv.sb_mb);
2346 }
2347
2348 static void
2349 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int))
2350 {
2351         struct mbuf *m;
2352         struct cmsghdr *cm;
2353         void *data;
2354         socklen_t clen, datalen;
2355
2356         while (m0 != NULL) {
2357                 for (m = m0; m; m = m->m_next) {
2358                         if (m->m_type != MT_CONTROL)
2359                                 continue;
2360
2361                         cm = mtod(m, struct cmsghdr *);
2362                         clen = m->m_len;
2363
2364                         while (cm != NULL) {
2365                                 if (sizeof(*cm) > clen || cm->cmsg_len > clen)
2366                                         break;
2367
2368                                 data = CMSG_DATA(cm);
2369                                 datalen = (caddr_t)cm + cm->cmsg_len
2370                                     - (caddr_t)data;
2371
2372                                 if (cm->cmsg_level == SOL_SOCKET &&
2373                                     cm->cmsg_type == SCM_RIGHTS) {
2374                                         (*op)(data, datalen /
2375                                             sizeof(struct filedescent *));
2376                                 }
2377
2378                                 if (CMSG_SPACE(datalen) < clen) {
2379                                         clen -= CMSG_SPACE(datalen);
2380                                         cm = (struct cmsghdr *)
2381                                             ((caddr_t)cm + CMSG_SPACE(datalen));
2382                                 } else {
2383                                         clen = 0;
2384                                         cm = NULL;
2385                                 }
2386                         }
2387                 }
2388                 m0 = m0->m_nextpkt;
2389         }
2390 }
2391
2392 /*
2393  * A helper function called by VFS before socket-type vnode reclamation.
2394  * For an active vnode it clears unp_vnode pointer and decrements unp_vnode
2395  * use count.
2396  */
2397 void
2398 vfs_unp_reclaim(struct vnode *vp)
2399 {
2400         struct socket *so;
2401         struct unpcb *unp;
2402         int active;
2403
2404         ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim");
2405         KASSERT(vp->v_type == VSOCK,
2406             ("vfs_unp_reclaim: vp->v_type != VSOCK"));
2407
2408         active = 0;
2409         UNP_LINK_WLOCK();
2410         VOP_UNP_CONNECT(vp, &so);
2411         if (so == NULL)
2412                 goto done;
2413         unp = sotounpcb(so);
2414         if (unp == NULL)
2415                 goto done;
2416         UNP_PCB_LOCK(unp);
2417         if (unp->unp_vnode == vp) {
2418                 VOP_UNP_DETACH(vp);
2419                 unp->unp_vnode = NULL;
2420                 active = 1;
2421         }
2422         UNP_PCB_UNLOCK(unp);
2423 done:
2424         UNP_LINK_WUNLOCK();
2425         if (active)
2426                 vunref(vp);
2427 }
2428
2429 #ifdef DDB
2430 static void
2431 db_print_indent(int indent)
2432 {
2433         int i;
2434
2435         for (i = 0; i < indent; i++)
2436                 db_printf(" ");
2437 }
2438
2439 static void
2440 db_print_unpflags(int unp_flags)
2441 {
2442         int comma;
2443
2444         comma = 0;
2445         if (unp_flags & UNP_HAVEPC) {
2446                 db_printf("%sUNP_HAVEPC", comma ? ", " : "");
2447                 comma = 1;
2448         }
2449         if (unp_flags & UNP_HAVEPCCACHED) {
2450                 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : "");
2451                 comma = 1;
2452         }
2453         if (unp_flags & UNP_WANTCRED) {
2454                 db_printf("%sUNP_WANTCRED", comma ? ", " : "");
2455                 comma = 1;
2456         }
2457         if (unp_flags & UNP_CONNWAIT) {
2458                 db_printf("%sUNP_CONNWAIT", comma ? ", " : "");
2459                 comma = 1;
2460         }
2461         if (unp_flags & UNP_CONNECTING) {
2462                 db_printf("%sUNP_CONNECTING", comma ? ", " : "");
2463                 comma = 1;
2464         }
2465         if (unp_flags & UNP_BINDING) {
2466                 db_printf("%sUNP_BINDING", comma ? ", " : "");
2467                 comma = 1;
2468         }
2469 }
2470
2471 static void
2472 db_print_xucred(int indent, struct xucred *xu)
2473 {
2474         int comma, i;
2475
2476         db_print_indent(indent);
2477         db_printf("cr_version: %u   cr_uid: %u   cr_ngroups: %d\n",
2478             xu->cr_version, xu->cr_uid, xu->cr_ngroups);
2479         db_print_indent(indent);
2480         db_printf("cr_groups: ");
2481         comma = 0;
2482         for (i = 0; i < xu->cr_ngroups; i++) {
2483                 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
2484                 comma = 1;
2485         }
2486         db_printf("\n");
2487 }
2488
2489 static void
2490 db_print_unprefs(int indent, struct unp_head *uh)
2491 {
2492         struct unpcb *unp;
2493         int counter;
2494
2495         counter = 0;
2496         LIST_FOREACH(unp, uh, unp_reflink) {
2497                 if (counter % 4 == 0)
2498                         db_print_indent(indent);
2499                 db_printf("%p  ", unp);
2500                 if (counter % 4 == 3)
2501                         db_printf("\n");
2502                 counter++;
2503         }
2504         if (counter != 0 && counter % 4 != 0)
2505                 db_printf("\n");
2506 }
2507
2508 DB_SHOW_COMMAND(unpcb, db_show_unpcb)
2509 {
2510         struct unpcb *unp;
2511
2512         if (!have_addr) {
2513                 db_printf("usage: show unpcb <addr>\n");
2514                 return;
2515         }
2516         unp = (struct unpcb *)addr;
2517
2518         db_printf("unp_socket: %p   unp_vnode: %p\n", unp->unp_socket,
2519             unp->unp_vnode);
2520
2521         db_printf("unp_ino: %ju   unp_conn: %p\n", (uintmax_t)unp->unp_ino,
2522             unp->unp_conn);
2523
2524         db_printf("unp_refs:\n");
2525         db_print_unprefs(2, &unp->unp_refs);
2526
2527         /* XXXRW: Would be nice to print the full address, if any. */
2528         db_printf("unp_addr: %p\n", unp->unp_addr);
2529
2530         db_printf("unp_gencnt: %llu\n",
2531             (unsigned long long)unp->unp_gencnt);
2532
2533         db_printf("unp_flags: %x (", unp->unp_flags);
2534         db_print_unpflags(unp->unp_flags);
2535         db_printf(")\n");
2536
2537         db_printf("unp_peercred:\n");
2538         db_print_xucred(2, &unp->unp_peercred);
2539
2540         db_printf("unp_refcount: %u\n", unp->unp_refcount);
2541 }
2542 #endif