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_dispose_so(struct socket *so);
 282 static void     unp_shutdown(struct unpcb *);
 283 static void     unp_drop(struct unpcb *);
 284 static void     unp_gc(__unused void *, int);
 285 static void     unp_scan(struct mbuf *, void (*)(struct filedescent **, int));
 286 static void     unp_discard(struct file *);
 287 static void     unp_freerights(struct filedescent **, int);
 288 static void     unp_init(void);
 289 static int      unp_internalize(struct mbuf **, struct thread *);
 290 static void     unp_internalize_fp(struct file *);
 291 static int      unp_externalize(struct mbuf *, struct mbuf **, int);
 292 static int      unp_externalize_fp(struct file *);
 293 static struct mbuf      *unp_addsockcred(struct thread *, struct mbuf *);
 294 static void     unp_process_defers(void * __unused, int);
 295
 296 /*
 297  * Definitions of protocols supported in the LOCAL domain.
 298  */
 299 static struct domain localdomain;
 300 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream;
 301 static struct pr_usrreqs uipc_usrreqs_seqpacket;
 302 static struct protosw localsw[] = {
 303 {
 304         .pr_type =              SOCK_STREAM,
 305         .pr_domain =            &localdomain,
 306         .pr_flags =             PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS,
 307         .pr_ctloutput =         &uipc_ctloutput,
 308         .pr_usrreqs =           &uipc_usrreqs_stream
 309 },
 310 {
 311         .pr_type =              SOCK_DGRAM,
 312         .pr_domain =            &localdomain,
 313         .pr_flags =             PR_ATOMIC|PR_ADDR|PR_RIGHTS,
 314         .pr_ctloutput =         &uipc_ctloutput,
 315         .pr_usrreqs =           &uipc_usrreqs_dgram
 316 },
 317 {
 318         .pr_type =              SOCK_SEQPACKET,
 319         .pr_domain =            &localdomain,
 320
 321         /*
 322          * XXXRW: For now, PR_ADDR because soreceive will bump into them
 323          * due to our use of sbappendaddr.  A new sbappend variants is needed
 324          * that supports both atomic record writes and control data.
 325          */
 326         .pr_flags =             PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD|
 327                                     PR_RIGHTS,
 328         .pr_ctloutput =         &uipc_ctloutput,
 329         .pr_usrreqs =           &uipc_usrreqs_seqpacket,
 330 },
 331 };
 332
 333 static struct domain localdomain = {
 334         .dom_family =           AF_LOCAL,
 335         .dom_name =             "local",
 336         .dom_init =             unp_init,
 337         .dom_externalize =      unp_externalize,
 338         .dom_dispose =          unp_dispose_so,
 339         .dom_protosw =          localsw,
 340         .dom_protoswNPROTOSW =  &localsw[nitems(localsw)]
 341 };
 342 DOMAIN_SET(local);
 343
 344 static void
 345 uipc_abort(struct socket *so)
 346 {
 347         struct unpcb *unp, *unp2;
 348
 349         unp = sotounpcb(so);
 350         KASSERT(unp != NULL, ("uipc_abort: unp == NULL"));
 351
 352         UNP_LINK_WLOCK();
 353         UNP_PCB_LOCK(unp);
 354         unp2 = unp->unp_conn;
 355         if (unp2 != NULL) {
 356                 UNP_PCB_LOCK(unp2);
 357                 unp_drop(unp2);
 358                 UNP_PCB_UNLOCK(unp2);
 359         }
 360         UNP_PCB_UNLOCK(unp);
 361         UNP_LINK_WUNLOCK();
 362 }
 363
 364 static int
 365 uipc_accept(struct socket *so, struct sockaddr **nam)
 366 {
 367         struct unpcb *unp, *unp2;
 368         const struct sockaddr *sa;
 369
 370         /*
 371          * Pass back name of connected socket, if it was bound and we are
 372          * still connected (our peer may have closed already!).
 373          */
 374         unp = sotounpcb(so);
 375         KASSERT(unp != NULL, ("uipc_accept: unp == NULL"));
 376
 377         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 378         UNP_LINK_RLOCK();
 379         unp2 = unp->unp_conn;
 380         if (unp2 != NULL && unp2->unp_addr != NULL) {
 381                 UNP_PCB_LOCK(unp2);
 382                 sa = (struct sockaddr *) unp2->unp_addr;
 383                 bcopy(sa, *nam, sa->sa_len);
 384                 UNP_PCB_UNLOCK(unp2);
 385         } else {
 386                 sa = &sun_noname;
 387                 bcopy(sa, *nam, sa->sa_len);
 388         }
 389         UNP_LINK_RUNLOCK();
 390         return (0);
 391 }
 392
 393 static int
 394 uipc_attach(struct socket *so, int proto, struct thread *td)
 395 {
 396         u_long sendspace, recvspace;
 397         struct unpcb *unp;
 398         int error;
 399
 400         KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL"));
 401         if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
 402                 switch (so->so_type) {
 403                 case SOCK_STREAM:
 404                         sendspace = unpst_sendspace;
 405                         recvspace = unpst_recvspace;
 406                         break;
 407
 408                 case SOCK_DGRAM:
 409                         sendspace = unpdg_sendspace;
 410                         recvspace = unpdg_recvspace;
 411                         break;
 412
 413                 case SOCK_SEQPACKET:
 414                         sendspace = unpsp_sendspace;
 415                         recvspace = unpsp_recvspace;
 416                         break;
 417
 418                 default:
 419                         panic("uipc_attach");
 420                 }
 421                 error = soreserve(so, sendspace, recvspace);
 422                 if (error)
 423                         return (error);
 424         }
 425         unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO);
 426         if (unp == NULL)
 427                 return (ENOBUFS);
 428         LIST_INIT(&unp->unp_refs);
 429         UNP_PCB_LOCK_INIT(unp);
 430         unp->unp_socket = so;
 431         so->so_pcb = unp;
 432         unp->unp_refcount = 1;
 433
 434         UNP_LIST_LOCK();
 435         unp->unp_gencnt = ++unp_gencnt;
 436         unp_count++;
 437         switch (so->so_type) {
 438         case SOCK_STREAM:
 439                 LIST_INSERT_HEAD(&unp_shead, unp, unp_link);
 440                 break;
 441
 442         case SOCK_DGRAM:
 443                 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link);
 444                 break;
 445
 446         case SOCK_SEQPACKET:
 447                 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link);
 448                 break;
 449
 450         default:
 451                 panic("uipc_attach");
 452         }
 453         UNP_LIST_UNLOCK();
 454
 455         return (0);
 456 }
 457
 458 static int
 459 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td)
 460 {
 461         struct sockaddr_un *soun = (struct sockaddr_un *)nam;
 462         struct vattr vattr;
 463         int error, namelen;
 464         struct nameidata nd;
 465         struct unpcb *unp;
 466         struct vnode *vp;
 467         struct mount *mp;
 468         cap_rights_t rights;
 469         char *buf;
 470
 471         if (nam->sa_family != AF_UNIX)
 472                 return (EAFNOSUPPORT);
 473
 474         unp = sotounpcb(so);
 475         KASSERT(unp != NULL, ("uipc_bind: unp == NULL"));
 476
 477         if (soun->sun_len > sizeof(struct sockaddr_un))
 478                 return (EINVAL);
 479         namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path);
 480         if (namelen <= 0)
 481                 return (EINVAL);
 482
 483         /*
 484          * We don't allow simultaneous bind() calls on a single UNIX domain
 485          * socket, so flag in-progress operations, and return an error if an
 486          * operation is already in progress.
 487          *
 488          * Historically, we have not allowed a socket to be rebound, so this
 489          * also returns an error.  Not allowing re-binding simplifies the
 490          * implementation and avoids a great many possible failure modes.
 491          */
 492         UNP_PCB_LOCK(unp);
 493         if (unp->unp_vnode != NULL) {
 494                 UNP_PCB_UNLOCK(unp);
 495                 return (EINVAL);
 496         }
 497         if (unp->unp_flags & UNP_BINDING) {
 498                 UNP_PCB_UNLOCK(unp);
 499                 return (EALREADY);
 500         }
 501         unp->unp_flags |= UNP_BINDING;
 502         UNP_PCB_UNLOCK(unp);
 503
 504         buf = malloc(namelen + 1, M_TEMP, M_WAITOK);
 505         bcopy(soun->sun_path, buf, namelen);
 506         buf[namelen] = 0;
 507
 508 restart:
 509         NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE,
 510             UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td);
 511 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */
 512         error = namei(&nd);
 513         if (error)
 514                 goto error;
 515         vp = nd.ni_vp;
 516         if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
 517                 NDFREE(&nd, NDF_ONLY_PNBUF);
 518                 if (nd.ni_dvp == vp)
 519                         vrele(nd.ni_dvp);
 520                 else
 521                         vput(nd.ni_dvp);
 522                 if (vp != NULL) {
 523                         vrele(vp);
 524                         error = EADDRINUSE;
 525                         goto error;
 526                 }
 527                 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
 528                 if (error)
 529                         goto error;
 530                 goto restart;
 531         }
 532         VATTR_NULL(&vattr);
 533         vattr.va_type = VSOCK;
 534         vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask);
 535 #ifdef MAC
 536         error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
 537             &vattr);
 538 #endif
 539         if (error == 0)
 540                 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
 541         NDFREE(&nd, NDF_ONLY_PNBUF);
 542         vput(nd.ni_dvp);
 543         if (error) {
 544                 vn_finished_write(mp);
 545                 goto error;
 546         }
 547         vp = nd.ni_vp;
 548         ASSERT_VOP_ELOCKED(vp, "uipc_bind");
 549         soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK);
 550
 551         UNP_LINK_WLOCK();
 552         UNP_PCB_LOCK(unp);
 553         VOP_UNP_BIND(vp, unp->unp_socket);
 554         unp->unp_vnode = vp;
 555         unp->unp_addr = soun;
 556         unp->unp_flags &= ~UNP_BINDING;
 557         UNP_PCB_UNLOCK(unp);
 558         UNP_LINK_WUNLOCK();
 559         VOP_UNLOCK(vp, 0);
 560         vn_finished_write(mp);
 561         free(buf, M_TEMP);
 562         return (0);
 563
 564 error:
 565         UNP_PCB_LOCK(unp);
 566         unp->unp_flags &= ~UNP_BINDING;
 567         UNP_PCB_UNLOCK(unp);
 568         free(buf, M_TEMP);
 569         return (error);
 570 }
 571
 572 static int
 573 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
 574 {
 575
 576         return (uipc_bindat(AT_FDCWD, so, nam, td));
 577 }
 578
 579 static int
 580 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
 581 {
 582         int error;
 583
 584         KASSERT(td == curthread, ("uipc_connect: td != curthread"));
 585         UNP_LINK_WLOCK();
 586         error = unp_connect(so, nam, td);
 587         UNP_LINK_WUNLOCK();
 588         return (error);
 589 }
 590
 591 static int
 592 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam,
 593     struct thread *td)
 594 {
 595         int error;
 596
 597         KASSERT(td == curthread, ("uipc_connectat: td != curthread"));
 598         UNP_LINK_WLOCK();
 599         error = unp_connectat(fd, so, nam, td);
 600         UNP_LINK_WUNLOCK();
 601         return (error);
 602 }
 603
 604 static void
 605 uipc_close(struct socket *so)
 606 {
 607         struct unpcb *unp, *unp2;
 608
 609         unp = sotounpcb(so);
 610         KASSERT(unp != NULL, ("uipc_close: unp == NULL"));
 611
 612         UNP_LINK_WLOCK();
 613         UNP_PCB_LOCK(unp);
 614         unp2 = unp->unp_conn;
 615         if (unp2 != NULL) {
 616                 UNP_PCB_LOCK(unp2);
 617                 unp_disconnect(unp, unp2);
 618                 UNP_PCB_UNLOCK(unp2);
 619         }
 620         UNP_PCB_UNLOCK(unp);
 621         UNP_LINK_WUNLOCK();
 622 }
 623
 624 static int
 625 uipc_connect2(struct socket *so1, struct socket *so2)
 626 {
 627         struct unpcb *unp, *unp2;
 628         int error;
 629
 630         UNP_LINK_WLOCK();
 631         unp = so1->so_pcb;
 632         KASSERT(unp != NULL, ("uipc_connect2: unp == NULL"));
 633         UNP_PCB_LOCK(unp);
 634         unp2 = so2->so_pcb;
 635         KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL"));
 636         UNP_PCB_LOCK(unp2);
 637         error = unp_connect2(so1, so2, PRU_CONNECT2);
 638         UNP_PCB_UNLOCK(unp2);
 639         UNP_PCB_UNLOCK(unp);
 640         UNP_LINK_WUNLOCK();
 641         return (error);
 642 }
 643
 644 static void
 645 uipc_detach(struct socket *so)
 646 {
 647         struct unpcb *unp, *unp2;
 648         struct sockaddr_un *saved_unp_addr;
 649         struct vnode *vp;
 650         int freeunp, local_unp_rights;
 651
 652         unp = sotounpcb(so);
 653         KASSERT(unp != NULL, ("uipc_detach: unp == NULL"));
 654
 655         UNP_LINK_WLOCK();
 656         UNP_LIST_LOCK();
 657         UNP_PCB_LOCK(unp);
 658         LIST_REMOVE(unp, unp_link);
 659         unp->unp_gencnt = ++unp_gencnt;
 660         --unp_count;
 661         UNP_LIST_UNLOCK();
 662
 663         /*
 664          * XXXRW: Should assert vp->v_socket == so.
 665          */
 666         if ((vp = unp->unp_vnode) != NULL) {
 667                 VOP_UNP_DETACH(vp);
 668                 unp->unp_vnode = NULL;
 669         }
 670         unp2 = unp->unp_conn;
 671         if (unp2 != NULL) {
 672                 UNP_PCB_LOCK(unp2);
 673                 unp_disconnect(unp, unp2);
 674                 UNP_PCB_UNLOCK(unp2);
 675         }
 676
 677         /*
 678          * We hold the linkage lock exclusively, so it's OK to acquire
 679          * multiple pcb locks at a time.
 680          */
 681         while (!LIST_EMPTY(&unp->unp_refs)) {
 682                 struct unpcb *ref = LIST_FIRST(&unp->unp_refs);
 683
 684                 UNP_PCB_LOCK(ref);
 685                 unp_drop(ref);
 686                 UNP_PCB_UNLOCK(ref);
 687         }
 688         local_unp_rights = unp_rights;
 689         UNP_LINK_WUNLOCK();
 690         unp->unp_socket->so_pcb = NULL;
 691         saved_unp_addr = unp->unp_addr;
 692         unp->unp_addr = NULL;
 693         unp->unp_refcount--;
 694         freeunp = (unp->unp_refcount == 0);
 695         if (saved_unp_addr != NULL)
 696                 free(saved_unp_addr, M_SONAME);
 697         if (freeunp) {
 698                 UNP_PCB_LOCK_DESTROY(unp);
 699                 uma_zfree(unp_zone, unp);
 700         } else
 701                 UNP_PCB_UNLOCK(unp);
 702         if (vp)
 703                 vrele(vp);
 704         if (local_unp_rights)
 705                 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1);
 706 }
 707
 708 static int
 709 uipc_disconnect(struct socket *so)
 710 {
 711         struct unpcb *unp, *unp2;
 712
 713         unp = sotounpcb(so);
 714         KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL"));
 715
 716         UNP_LINK_WLOCK();
 717         UNP_PCB_LOCK(unp);
 718         unp2 = unp->unp_conn;
 719         if (unp2 != NULL) {
 720                 UNP_PCB_LOCK(unp2);
 721                 unp_disconnect(unp, unp2);
 722                 UNP_PCB_UNLOCK(unp2);
 723         }
 724         UNP_PCB_UNLOCK(unp);
 725         UNP_LINK_WUNLOCK();
 726         return (0);
 727 }
 728
 729 static int
 730 uipc_listen(struct socket *so, int backlog, struct thread *td)
 731 {
 732         struct unpcb *unp;
 733         int error;
 734
 735         unp = sotounpcb(so);
 736         KASSERT(unp != NULL, ("uipc_listen: unp == NULL"));
 737
 738         UNP_PCB_LOCK(unp);
 739         if (unp->unp_vnode == NULL) {
 740                 /* Already connected or not bound to an address. */
 741                 error = unp->unp_conn != NULL ? EINVAL : EDESTADDRREQ;
 742                 UNP_PCB_UNLOCK(unp);
 743                 return (error);
 744         }
 745
 746         SOCK_LOCK(so);
 747         error = solisten_proto_check(so);
 748         if (error == 0) {
 749                 cru2x(td->td_ucred, &unp->unp_peercred);
 750                 unp->unp_flags |= UNP_HAVEPCCACHED;
 751                 solisten_proto(so, backlog);
 752         }
 753         SOCK_UNLOCK(so);
 754         UNP_PCB_UNLOCK(unp);
 755         return (error);
 756 }
 757
 758 static int
 759 uipc_peeraddr(struct socket *so, struct sockaddr **nam)
 760 {
 761         struct unpcb *unp, *unp2;
 762         const struct sockaddr *sa;
 763
 764         unp = sotounpcb(so);
 765         KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL"));
 766
 767         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
 768         UNP_LINK_RLOCK();
 769         /*
 770          * XXX: It seems that this test always fails even when connection is
 771          * established.  So, this else clause is added as workaround to
 772          * return PF_LOCAL sockaddr.
 773          */
 774         unp2 = unp->unp_conn;
 775         if (unp2 != NULL) {
 776                 UNP_PCB_LOCK(unp2);
 777                 if (unp2->unp_addr != NULL)
 778                         sa = (struct sockaddr *) unp2->unp_addr;
 779                 else
 780                         sa = &sun_noname;
 781                 bcopy(sa, *nam, sa->sa_len);
 782                 UNP_PCB_UNLOCK(unp2);
 783         } else {
 784                 sa = &sun_noname;
 785                 bcopy(sa, *nam, sa->sa_len);
 786         }
 787         UNP_LINK_RUNLOCK();
 788         return (0);
 789 }
 790
 791 static int
 792 uipc_rcvd(struct socket *so, int flags)
 793 {
 794         struct unpcb *unp, *unp2;
 795         struct socket *so2;
 796         u_int mbcnt, sbcc;
 797
 798         unp = sotounpcb(so);
 799         KASSERT(unp != NULL, ("%s: unp == NULL", __func__));
 800         KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET,
 801             ("%s: socktype %d", __func__, so->so_type));
 802
 803         /*
 804          * Adjust backpressure on sender and wakeup any waiting to write.
 805          *
 806          * The unp lock is acquired to maintain the validity of the unp_conn
 807          * pointer; no lock on unp2 is required as unp2->unp_socket will be
 808          * static as long as we don't permit unp2 to disconnect from unp,
 809          * which is prevented by the lock on unp.  We cache values from
 810          * so_rcv to avoid holding the so_rcv lock over the entire
 811          * transaction on the remote so_snd.
 812          */
 813         SOCKBUF_LOCK(&so->so_rcv);
 814         mbcnt = so->so_rcv.sb_mbcnt;
 815         sbcc = sbavail(&so->so_rcv);
 816         SOCKBUF_UNLOCK(&so->so_rcv);
 817         /*
 818          * There is a benign race condition at this point.  If we're planning to
 819          * clear SB_STOP, but uipc_send is called on the connected socket at
 820          * this instant, it might add data to the sockbuf and set SB_STOP.  Then
 821          * we would erroneously clear SB_STOP below, even though the sockbuf is
 822          * full.  The race is benign because the only ill effect is to allow the
 823          * sockbuf to exceed its size limit, and the size limits are not
 824          * strictly guaranteed anyway.
 825          */
 826         UNP_PCB_LOCK(unp);
 827         unp2 = unp->unp_conn;
 828         if (unp2 == NULL) {
 829                 UNP_PCB_UNLOCK(unp);
 830                 return (0);
 831         }
 832         so2 = unp2->unp_socket;
 833         SOCKBUF_LOCK(&so2->so_snd);
 834         if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax)
 835                 so2->so_snd.sb_flags &= ~SB_STOP;
 836         sowwakeup_locked(so2);
 837         UNP_PCB_UNLOCK(unp);
 838         return (0);
 839 }
 840
 841 static int
 842 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
 843     struct mbuf *control, struct thread *td)
 844 {
 845         struct unpcb *unp, *unp2;
 846         struct socket *so2;
 847         u_int mbcnt, sbcc;
 848         int error = 0;
 849
 850         unp = sotounpcb(so);
 851         KASSERT(unp != NULL, ("%s: unp == NULL", __func__));
 852         KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM ||
 853             so->so_type == SOCK_SEQPACKET,
 854             ("%s: socktype %d", __func__, so->so_type));
 855
 856         if (flags & PRUS_OOB) {
 857                 error = EOPNOTSUPP;
 858                 goto release;
 859         }
 860         if (control != NULL && (error = unp_internalize(&control, td)))
 861                 goto release;
 862         if ((nam != NULL) || (flags & PRUS_EOF))
 863                 UNP_LINK_WLOCK();
 864         else
 865                 UNP_LINK_RLOCK();
 866         switch (so->so_type) {
 867         case SOCK_DGRAM:
 868         {
 869                 const struct sockaddr *from;
 870
 871                 unp2 = unp->unp_conn;
 872                 if (nam != NULL) {
 873                         UNP_LINK_WLOCK_ASSERT();
 874                         if (unp2 != NULL) {
 875                                 error = EISCONN;
 876                                 break;
 877                         }
 878                         error = unp_connect(so, nam, td);
 879                         if (error)
 880                                 break;
 881                         unp2 = unp->unp_conn;
 882                 }
 883
 884                 /*
 885                  * Because connect() and send() are non-atomic in a sendto()
 886                  * with a target address, it's possible that the socket will
 887                  * have disconnected before the send() can run.  In that case
 888                  * return the slightly counter-intuitive but otherwise
 889                  * correct error that the socket is not connected.
 890                  */
 891                 if (unp2 == NULL) {
 892                         error = ENOTCONN;
 893                         break;
 894                 }
 895                 /* Lockless read. */
 896                 if (unp2->unp_flags & UNP_WANTCRED)
 897                         control = unp_addsockcred(td, control);
 898                 UNP_PCB_LOCK(unp);
 899                 if (unp->unp_addr != NULL)
 900                         from = (struct sockaddr *)unp->unp_addr;
 901                 else
 902                         from = &sun_noname;
 903                 so2 = unp2->unp_socket;
 904                 SOCKBUF_LOCK(&so2->so_rcv);
 905                 if (sbappendaddr_locked(&so2->so_rcv, from, m,
 906                     control)) {
 907                         sorwakeup_locked(so2);
 908                         m = NULL;
 909                         control = NULL;
 910                 } else {
 911                         SOCKBUF_UNLOCK(&so2->so_rcv);
 912                         error = ENOBUFS;
 913                 }
 914                 if (nam != NULL) {
 915                         UNP_LINK_WLOCK_ASSERT();
 916                         UNP_PCB_LOCK(unp2);
 917                         unp_disconnect(unp, unp2);
 918                         UNP_PCB_UNLOCK(unp2);
 919                 }
 920                 UNP_PCB_UNLOCK(unp);
 921                 break;
 922         }
 923
 924         case SOCK_SEQPACKET:
 925         case SOCK_STREAM:
 926                 if ((so->so_state & SS_ISCONNECTED) == 0) {
 927                         if (nam != NULL) {
 928                                 UNP_LINK_WLOCK_ASSERT();
 929                                 error = unp_connect(so, nam, td);
 930                                 if (error)
 931                                         break;  /* XXX */
 932                         } else {
 933                                 error = ENOTCONN;
 934                                 break;
 935                         }
 936                 }
 937
 938                 /* Lockless read. */
 939                 if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
 940                         error = EPIPE;
 941                         break;
 942                 }
 943
 944                 /*
 945                  * Because connect() and send() are non-atomic in a sendto()
 946                  * with a target address, it's possible that the socket will
 947                  * have disconnected before the send() can run.  In that case
 948                  * return the slightly counter-intuitive but otherwise
 949                  * correct error that the socket is not connected.
 950                  *
 951                  * Locking here must be done carefully: the linkage lock
 952                  * prevents interconnections between unpcbs from changing, so
 953                  * we can traverse from unp to unp2 without acquiring unp's
 954                  * lock.  Socket buffer locks follow unpcb locks, so we can
 955                  * acquire both remote and lock socket buffer locks.
 956                  */
 957                 unp2 = unp->unp_conn;
 958                 if (unp2 == NULL) {
 959                         error = ENOTCONN;
 960                         break;
 961                 }
 962                 so2 = unp2->unp_socket;
 963                 UNP_PCB_LOCK(unp2);
 964                 SOCKBUF_LOCK(&so2->so_rcv);
 965                 if (unp2->unp_flags & UNP_WANTCRED) {
 966                         /*
 967                          * Credentials are passed only once on SOCK_STREAM
 968                          * and SOCK_SEQPACKET.
 969                          */
 970                         unp2->unp_flags &= ~UNP_WANTCRED;
 971                         control = unp_addsockcred(td, control);
 972                 }
 973                 /*
 974                  * Send to paired receive port, and then reduce send buffer
 975                  * hiwater marks to maintain backpressure.  Wake up readers.
 976                  */
 977                 switch (so->so_type) {
 978                 case SOCK_STREAM:
 979                         if (control != NULL) {
 980                                 if (sbappendcontrol_locked(&so2->so_rcv, m,
 981                                     control))
 982                                         control = NULL;
 983                         } else
 984                                 sbappend_locked(&so2->so_rcv, m, flags);
 985                         break;
 986
 987                 case SOCK_SEQPACKET: {
 988                         const struct sockaddr *from;
 989
 990                         from = &sun_noname;
 991                         /*
 992                          * Don't check for space available in so2->so_rcv.
 993                          * Unix domain sockets only check for space in the
 994                          * sending sockbuf, and that check is performed one
 995                          * level up the stack.
 996                          */
 997                         if (sbappendaddr_nospacecheck_locked(&so2->so_rcv,
 998                                 from, m, control))
 999                                 control = NULL;
1000                         break;
1001                         }
1002                 }
1003
1004                 mbcnt = so2->so_rcv.sb_mbcnt;
1005                 sbcc = sbavail(&so2->so_rcv);
1006                 if (sbcc)
1007                         sorwakeup_locked(so2);
1008                 else
1009                         SOCKBUF_UNLOCK(&so2->so_rcv);
1010
1011                 /*
1012                  * The PCB lock on unp2 protects the SB_STOP flag.  Without it,
1013                  * it would be possible for uipc_rcvd to be called at this
1014                  * point, drain the receiving sockbuf, clear SB_STOP, and then
1015                  * we would set SB_STOP below.  That could lead to an empty
1016                  * sockbuf having SB_STOP set
1017                  */
1018                 SOCKBUF_LOCK(&so->so_snd);
1019                 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax)
1020                         so->so_snd.sb_flags |= SB_STOP;
1021                 SOCKBUF_UNLOCK(&so->so_snd);
1022                 UNP_PCB_UNLOCK(unp2);
1023                 m = NULL;
1024                 break;
1025         }
1026
1027         /*
1028          * PRUS_EOF is equivalent to pru_send followed by pru_shutdown.
1029          */
1030         if (flags & PRUS_EOF) {
1031                 UNP_PCB_LOCK(unp);
1032                 socantsendmore(so);
1033                 unp_shutdown(unp);
1034                 UNP_PCB_UNLOCK(unp);
1035         }
1036
1037         if ((nam != NULL) || (flags & PRUS_EOF))
1038                 UNP_LINK_WUNLOCK();
1039         else
1040                 UNP_LINK_RUNLOCK();
1041
1042         if (control != NULL && error != 0)
1043                 unp_dispose(control);
1044
1045 release:
1046         if (control != NULL)
1047                 m_freem(control);
1048         if (m != NULL)
1049                 m_freem(m);
1050         return (error);
1051 }
1052
1053 static int
1054 uipc_ready(struct socket *so, struct mbuf *m, int count)
1055 {
1056         struct unpcb *unp, *unp2;
1057         struct socket *so2;
1058         int error;
1059
1060         unp = sotounpcb(so);
1061
1062         UNP_LINK_RLOCK();
1063         unp2 = unp->unp_conn;
1064         UNP_PCB_LOCK(unp2);
1065         so2 = unp2->unp_socket;
1066
1067         SOCKBUF_LOCK(&so2->so_rcv);
1068         if ((error = sbready(&so2->so_rcv, m, count)) == 0)
1069                 sorwakeup_locked(so2);
1070         else
1071                 SOCKBUF_UNLOCK(&so2->so_rcv);
1072
1073         UNP_PCB_UNLOCK(unp2);
1074         UNP_LINK_RUNLOCK();
1075
1076         return (error);
1077 }
1078
1079 static int
1080 uipc_sense(struct socket *so, struct stat *sb)
1081 {
1082         struct unpcb *unp;
1083
1084         unp = sotounpcb(so);
1085         KASSERT(unp != NULL, ("uipc_sense: unp == NULL"));
1086
1087         sb->st_blksize = so->so_snd.sb_hiwat;
1088         UNP_PCB_LOCK(unp);
1089         sb->st_dev = NODEV;
1090         if (unp->unp_ino == 0)
1091                 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino;
1092         sb->st_ino = unp->unp_ino;
1093         UNP_PCB_UNLOCK(unp);
1094         return (0);
1095 }
1096
1097 static int
1098 uipc_shutdown(struct socket *so)
1099 {
1100         struct unpcb *unp;
1101
1102         unp = sotounpcb(so);
1103         KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL"));
1104
1105         UNP_LINK_WLOCK();
1106         UNP_PCB_LOCK(unp);
1107         socantsendmore(so);
1108         unp_shutdown(unp);
1109         UNP_PCB_UNLOCK(unp);
1110         UNP_LINK_WUNLOCK();
1111         return (0);
1112 }
1113
1114 static int
1115 uipc_sockaddr(struct socket *so, struct sockaddr **nam)
1116 {
1117         struct unpcb *unp;
1118         const struct sockaddr *sa;
1119
1120         unp = sotounpcb(so);
1121         KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL"));
1122
1123         *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1124         UNP_PCB_LOCK(unp);
1125         if (unp->unp_addr != NULL)
1126                 sa = (struct sockaddr *) unp->unp_addr;
1127         else
1128                 sa = &sun_noname;
1129         bcopy(sa, *nam, sa->sa_len);
1130         UNP_PCB_UNLOCK(unp);
1131         return (0);
1132 }
1133
1134 static struct pr_usrreqs uipc_usrreqs_dgram = {
1135         .pru_abort =            uipc_abort,
1136         .pru_accept =           uipc_accept,
1137         .pru_attach =           uipc_attach,
1138         .pru_bind =             uipc_bind,
1139         .pru_bindat =           uipc_bindat,
1140         .pru_connect =          uipc_connect,
1141         .pru_connectat =        uipc_connectat,
1142         .pru_connect2 =         uipc_connect2,
1143         .pru_detach =           uipc_detach,
1144         .pru_disconnect =       uipc_disconnect,
1145         .pru_listen =           uipc_listen,
1146         .pru_peeraddr =         uipc_peeraddr,
1147         .pru_rcvd =             uipc_rcvd,
1148         .pru_send =             uipc_send,
1149         .pru_sense =            uipc_sense,
1150         .pru_shutdown =         uipc_shutdown,
1151         .pru_sockaddr =         uipc_sockaddr,
1152         .pru_soreceive =        soreceive_dgram,
1153         .pru_close =            uipc_close,
1154 };
1155
1156 static struct pr_usrreqs uipc_usrreqs_seqpacket = {
1157         .pru_abort =            uipc_abort,
1158         .pru_accept =           uipc_accept,
1159         .pru_attach =           uipc_attach,
1160         .pru_bind =             uipc_bind,
1161         .pru_bindat =           uipc_bindat,
1162         .pru_connect =          uipc_connect,
1163         .pru_connectat =        uipc_connectat,
1164         .pru_connect2 =         uipc_connect2,
1165         .pru_detach =           uipc_detach,
1166         .pru_disconnect =       uipc_disconnect,
1167         .pru_listen =           uipc_listen,
1168         .pru_peeraddr =         uipc_peeraddr,
1169         .pru_rcvd =             uipc_rcvd,
1170         .pru_send =             uipc_send,
1171         .pru_sense =            uipc_sense,
1172         .pru_shutdown =         uipc_shutdown,
1173         .pru_sockaddr =         uipc_sockaddr,
1174         .pru_soreceive =        soreceive_generic,      /* XXX: or...? */
1175         .pru_close =            uipc_close,
1176 };
1177
1178 static struct pr_usrreqs uipc_usrreqs_stream = {
1179         .pru_abort =            uipc_abort,
1180         .pru_accept =           uipc_accept,
1181         .pru_attach =           uipc_attach,
1182         .pru_bind =             uipc_bind,
1183         .pru_bindat =           uipc_bindat,
1184         .pru_connect =          uipc_connect,
1185         .pru_connectat =        uipc_connectat,
1186         .pru_connect2 =         uipc_connect2,
1187         .pru_detach =           uipc_detach,
1188         .pru_disconnect =       uipc_disconnect,
1189         .pru_listen =           uipc_listen,
1190         .pru_peeraddr =         uipc_peeraddr,
1191         .pru_rcvd =             uipc_rcvd,
1192         .pru_send =             uipc_send,
1193         .pru_ready =            uipc_ready,
1194         .pru_sense =            uipc_sense,
1195         .pru_shutdown =         uipc_shutdown,
1196         .pru_sockaddr =         uipc_sockaddr,
1197         .pru_soreceive =        soreceive_generic,
1198         .pru_close =            uipc_close,
1199 };
1200
1201 static int
1202 uipc_ctloutput(struct socket *so, struct sockopt *sopt)
1203 {
1204         struct unpcb *unp;
1205         struct xucred xu;
1206         int error, optval;
1207
1208         if (sopt->sopt_level != 0)
1209                 return (EINVAL);
1210
1211         unp = sotounpcb(so);
1212         KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL"));
1213         error = 0;
1214         switch (sopt->sopt_dir) {
1215         case SOPT_GET:
1216                 switch (sopt->sopt_name) {
1217                 case LOCAL_PEERCRED:
1218                         UNP_PCB_LOCK(unp);
1219                         if (unp->unp_flags & UNP_HAVEPC)
1220                                 xu = unp->unp_peercred;
1221                         else {
1222                                 if (so->so_type == SOCK_STREAM)
1223                                         error = ENOTCONN;
1224                                 else
1225                                         error = EINVAL;
1226                         }
1227                         UNP_PCB_UNLOCK(unp);
1228                         if (error == 0)
1229                                 error = sooptcopyout(sopt, &xu, sizeof(xu));
1230                         break;
1231
1232                 case LOCAL_CREDS:
1233                         /* Unlocked read. */
1234                         optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0;
1235                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1236                         break;
1237
1238                 case LOCAL_CONNWAIT:
1239                         /* Unlocked read. */
1240                         optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0;
1241                         error = sooptcopyout(sopt, &optval, sizeof(optval));
1242                         break;
1243
1244                 default:
1245                         error = EOPNOTSUPP;
1246                         break;
1247                 }
1248                 break;
1249
1250         case SOPT_SET:
1251                 switch (sopt->sopt_name) {
1252                 case LOCAL_CREDS:
1253                 case LOCAL_CONNWAIT:
1254                         error = sooptcopyin(sopt, &optval, sizeof(optval),
1255                                             sizeof(optval));
1256                         if (error)
1257                                 break;
1258
1259 #define OPTSET(bit) do {                                                \
1260         UNP_PCB_LOCK(unp);                                              \
1261         if (optval)                                                     \
1262                 unp->unp_flags |= bit;                                  \
1263         else                                                            \
1264                 unp->unp_flags &= ~bit;                                 \
1265         UNP_PCB_UNLOCK(unp);                                            \
1266 } while (0)
1267
1268                         switch (sopt->sopt_name) {
1269                         case LOCAL_CREDS:
1270                                 OPTSET(UNP_WANTCRED);
1271                                 break;
1272
1273                         case LOCAL_CONNWAIT:
1274                                 OPTSET(UNP_CONNWAIT);
1275                                 break;
1276
1277                         default:
1278                                 break;
1279                         }
1280                         break;
1281 #undef  OPTSET
1282                 default:
1283                         error = ENOPROTOOPT;
1284                         break;
1285                 }
1286                 break;
1287
1288         default:
1289                 error = EOPNOTSUPP;
1290                 break;
1291         }
1292         return (error);
1293 }
1294
1295 static int
1296 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
1297 {
1298
1299         return (unp_connectat(AT_FDCWD, so, nam, td));
1300 }
1301
1302 static int
1303 unp_connectat(int fd, struct socket *so, struct sockaddr *nam,
1304     struct thread *td)
1305 {
1306         struct sockaddr_un *soun = (struct sockaddr_un *)nam;
1307         struct vnode *vp;
1308         struct socket *so2, *so3;
1309         struct unpcb *unp, *unp2, *unp3;
1310         struct nameidata nd;
1311         char buf[SOCK_MAXADDRLEN];
1312         struct sockaddr *sa;
1313         cap_rights_t rights;
1314         int error, len;
1315
1316         if (nam->sa_family != AF_UNIX)
1317                 return (EAFNOSUPPORT);
1318
1319         UNP_LINK_WLOCK_ASSERT();
1320
1321         unp = sotounpcb(so);
1322         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1323
1324         if (nam->sa_len > sizeof(struct sockaddr_un))
1325                 return (EINVAL);
1326         len = nam->sa_len - offsetof(struct sockaddr_un, sun_path);
1327         if (len <= 0)
1328                 return (EINVAL);
1329         bcopy(soun->sun_path, buf, len);
1330         buf[len] = 0;
1331
1332         UNP_PCB_LOCK(unp);
1333         if (unp->unp_flags & UNP_CONNECTING) {
1334                 UNP_PCB_UNLOCK(unp);
1335                 return (EALREADY);
1336         }
1337         UNP_LINK_WUNLOCK();
1338         unp->unp_flags |= UNP_CONNECTING;
1339         UNP_PCB_UNLOCK(unp);
1340
1341         sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK);
1342         NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF,
1343             UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td);
1344         error = namei(&nd);
1345         if (error)
1346                 vp = NULL;
1347         else
1348                 vp = nd.ni_vp;
1349         ASSERT_VOP_LOCKED(vp, "unp_connect");
1350         NDFREE(&nd, NDF_ONLY_PNBUF);
1351         if (error)
1352                 goto bad;
1353
1354         if (vp->v_type != VSOCK) {
1355                 error = ENOTSOCK;
1356                 goto bad;
1357         }
1358 #ifdef MAC
1359         error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD);
1360         if (error)
1361                 goto bad;
1362 #endif
1363         error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
1364         if (error)
1365                 goto bad;
1366
1367         unp = sotounpcb(so);
1368         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1369
1370         /*
1371          * Lock linkage lock for two reasons: make sure v_socket is stable,
1372          * and to protect simultaneous locking of multiple pcbs.
1373          */
1374         UNP_LINK_WLOCK();
1375         VOP_UNP_CONNECT(vp, &so2);
1376         if (so2 == NULL) {
1377                 error = ECONNREFUSED;
1378                 goto bad2;
1379         }
1380         if (so->so_type != so2->so_type) {
1381                 error = EPROTOTYPE;
1382                 goto bad2;
1383         }
1384         if (so->so_proto->pr_flags & PR_CONNREQUIRED) {
1385                 if (so2->so_options & SO_ACCEPTCONN) {
1386                         CURVNET_SET(so2->so_vnet);
1387                         so3 = sonewconn(so2, 0);
1388                         CURVNET_RESTORE();
1389                 } else
1390                         so3 = NULL;
1391                 if (so3 == NULL) {
1392                         error = ECONNREFUSED;
1393                         goto bad2;
1394                 }
1395                 unp = sotounpcb(so);
1396                 unp2 = sotounpcb(so2);
1397                 unp3 = sotounpcb(so3);
1398                 UNP_PCB_LOCK(unp);
1399                 UNP_PCB_LOCK(unp2);
1400                 UNP_PCB_LOCK(unp3);
1401                 if (unp2->unp_addr != NULL) {
1402                         bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len);
1403                         unp3->unp_addr = (struct sockaddr_un *) sa;
1404                         sa = NULL;
1405                 }
1406
1407                 /*
1408                  * The connector's (client's) credentials are copied from its
1409                  * process structure at the time of connect() (which is now).
1410                  */
1411                 cru2x(td->td_ucred, &unp3->unp_peercred);
1412                 unp3->unp_flags |= UNP_HAVEPC;
1413
1414                 /*
1415                  * The receiver's (server's) credentials are copied from the
1416                  * unp_peercred member of socket on which the former called
1417                  * listen(); uipc_listen() cached that process's credentials
1418                  * at that time so we can use them now.
1419                  */
1420                 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED,
1421                     ("unp_connect: listener without cached peercred"));
1422                 memcpy(&unp->unp_peercred, &unp2->unp_peercred,
1423                     sizeof(unp->unp_peercred));
1424                 unp->unp_flags |= UNP_HAVEPC;
1425                 if (unp2->unp_flags & UNP_WANTCRED)
1426                         unp3->unp_flags |= UNP_WANTCRED;
1427                 UNP_PCB_UNLOCK(unp3);
1428                 UNP_PCB_UNLOCK(unp2);
1429                 UNP_PCB_UNLOCK(unp);
1430 #ifdef MAC
1431                 mac_socketpeer_set_from_socket(so, so3);
1432                 mac_socketpeer_set_from_socket(so3, so);
1433 #endif
1434
1435                 so2 = so3;
1436         }
1437         unp = sotounpcb(so);
1438         KASSERT(unp != NULL, ("unp_connect: unp == NULL"));
1439         unp2 = sotounpcb(so2);
1440         KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL"));
1441         UNP_PCB_LOCK(unp);
1442         UNP_PCB_LOCK(unp2);
1443         error = unp_connect2(so, so2, PRU_CONNECT);
1444         UNP_PCB_UNLOCK(unp2);
1445         UNP_PCB_UNLOCK(unp);
1446 bad2:
1447         UNP_LINK_WUNLOCK();
1448 bad:
1449         if (vp != NULL)
1450                 vput(vp);
1451         free(sa, M_SONAME);
1452         UNP_LINK_WLOCK();
1453         UNP_PCB_LOCK(unp);
1454         unp->unp_flags &= ~UNP_CONNECTING;
1455         UNP_PCB_UNLOCK(unp);
1456         return (error);
1457 }
1458
1459 static int
1460 unp_connect2(struct socket *so, struct socket *so2, int req)
1461 {
1462         struct unpcb *unp;
1463         struct unpcb *unp2;
1464
1465         unp = sotounpcb(so);
1466         KASSERT(unp != NULL, ("unp_connect2: unp == NULL"));
1467         unp2 = sotounpcb(so2);
1468         KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL"));
1469
1470         UNP_LINK_WLOCK_ASSERT();
1471         UNP_PCB_LOCK_ASSERT(unp);
1472         UNP_PCB_LOCK_ASSERT(unp2);
1473
1474         if (so2->so_type != so->so_type)
1475                 return (EPROTOTYPE);
1476         unp->unp_conn = unp2;
1477
1478         switch (so->so_type) {
1479         case SOCK_DGRAM:
1480                 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink);
1481                 soisconnected(so);
1482                 break;
1483
1484         case SOCK_STREAM:
1485         case SOCK_SEQPACKET:
1486                 unp2->unp_conn = unp;
1487                 if (req == PRU_CONNECT &&
1488                     ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT))
1489                         soisconnecting(so);
1490                 else
1491                         soisconnected(so);
1492                 soisconnected(so2);
1493                 break;
1494
1495         default:
1496                 panic("unp_connect2");
1497         }
1498         return (0);
1499 }
1500
1501 static void
1502 unp_disconnect(struct unpcb *unp, struct unpcb *unp2)
1503 {
1504         struct socket *so;
1505
1506         KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL"));
1507
1508         UNP_LINK_WLOCK_ASSERT();
1509         UNP_PCB_LOCK_ASSERT(unp);
1510         UNP_PCB_LOCK_ASSERT(unp2);
1511
1512         unp->unp_conn = NULL;
1513         switch (unp->unp_socket->so_type) {
1514         case SOCK_DGRAM:
1515                 LIST_REMOVE(unp, unp_reflink);
1516                 so = unp->unp_socket;
1517                 SOCK_LOCK(so);
1518                 so->so_state &= ~SS_ISCONNECTED;
1519                 SOCK_UNLOCK(so);
1520                 break;
1521
1522         case SOCK_STREAM:
1523         case SOCK_SEQPACKET:
1524                 soisdisconnected(unp->unp_socket);
1525                 unp2->unp_conn = NULL;
1526                 soisdisconnected(unp2->unp_socket);
1527                 break;
1528         }
1529 }
1530
1531 /*
1532  * unp_pcblist() walks the global list of struct unpcb's to generate a
1533  * pointer list, bumping the refcount on each unpcb.  It then copies them out
1534  * sequentially, validating the generation number on each to see if it has
1535  * been detached.  All of this is necessary because copyout() may sleep on
1536  * disk I/O.
1537  */
1538 static int
1539 unp_pcblist(SYSCTL_HANDLER_ARGS)
1540 {
1541         int error, i, n;
1542         int freeunp;
1543         struct unpcb *unp, **unp_list;
1544         unp_gen_t gencnt;
1545         struct xunpgen *xug;
1546         struct unp_head *head;
1547         struct xunpcb *xu;
1548
1549         switch ((intptr_t)arg1) {
1550         case SOCK_STREAM:
1551                 head = &unp_shead;
1552                 break;
1553
1554         case SOCK_DGRAM:
1555                 head = &unp_dhead;
1556                 break;
1557
1558         case SOCK_SEQPACKET:
1559                 head = &unp_sphead;
1560                 break;
1561
1562         default:
1563                 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1);
1564         }
1565
1566         /*
1567          * The process of preparing the PCB list is too time-consuming and
1568          * resource-intensive to repeat twice on every request.
1569          */
1570         if (req->oldptr == NULL) {
1571                 n = unp_count;
1572                 req->oldidx = 2 * (sizeof *xug)
1573                         + (n + n/8) * sizeof(struct xunpcb);
1574                 return (0);
1575         }
1576
1577         if (req->newptr != NULL)
1578                 return (EPERM);
1579
1580         /*
1581          * OK, now we're committed to doing something.
1582          */
1583         xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK);
1584         UNP_LIST_LOCK();
1585         gencnt = unp_gencnt;
1586         n = unp_count;
1587         UNP_LIST_UNLOCK();
1588
1589         xug->xug_len = sizeof *xug;
1590         xug->xug_count = n;
1591         xug->xug_gen = gencnt;
1592         xug->xug_sogen = so_gencnt;
1593         error = SYSCTL_OUT(req, xug, sizeof *xug);
1594         if (error) {
1595                 free(xug, M_TEMP);
1596                 return (error);
1597         }
1598
1599         unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK);
1600
1601         UNP_LIST_LOCK();
1602         for (unp = LIST_FIRST(head), i = 0; unp && i < n;
1603              unp = LIST_NEXT(unp, unp_link)) {
1604                 UNP_PCB_LOCK(unp);
1605                 if (unp->unp_gencnt <= gencnt) {
1606                         if (cr_cansee(req->td->td_ucred,
1607                             unp->unp_socket->so_cred)) {
1608                                 UNP_PCB_UNLOCK(unp);
1609                                 continue;
1610                         }
1611                         unp_list[i++] = unp;
1612                         unp->unp_refcount++;
1613                 }
1614                 UNP_PCB_UNLOCK(unp);
1615         }
1616         UNP_LIST_UNLOCK();
1617         n = i;                  /* In case we lost some during malloc. */
1618
1619         error = 0;
1620         xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO);
1621         for (i = 0; i < n; i++) {
1622                 unp = unp_list[i];
1623                 UNP_PCB_LOCK(unp);
1624                 unp->unp_refcount--;
1625                 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) {
1626                         xu->xu_len = sizeof *xu;
1627                         xu->xu_unpp = unp;
1628                         /*
1629                          * XXX - need more locking here to protect against
1630                          * connect/disconnect races for SMP.
1631                          */
1632                         if (unp->unp_addr != NULL)
1633                                 bcopy(unp->unp_addr, &xu->xu_addr,
1634                                       unp->unp_addr->sun_len);
1635                         if (unp->unp_conn != NULL &&
1636                             unp->unp_conn->unp_addr != NULL)
1637                                 bcopy(unp->unp_conn->unp_addr,
1638                                       &xu->xu_caddr,
1639                                       unp->unp_conn->unp_addr->sun_len);
1640                         bcopy(unp, &xu->xu_unp, sizeof *unp);
1641                         sotoxsocket(unp->unp_socket, &xu->xu_socket);
1642                         UNP_PCB_UNLOCK(unp);
1643                         error = SYSCTL_OUT(req, xu, sizeof *xu);
1644                 } else {
1645                         freeunp = (unp->unp_refcount == 0);
1646                         UNP_PCB_UNLOCK(unp);
1647                         if (freeunp) {
1648                                 UNP_PCB_LOCK_DESTROY(unp);
1649                                 uma_zfree(unp_zone, unp);
1650                         }
1651                 }
1652         }
1653         free(xu, M_TEMP);
1654         if (!error) {
1655                 /*
1656                  * Give the user an updated idea of our state.  If the
1657                  * generation differs from what we told her before, she knows
1658                  * that something happened while we were processing this
1659                  * request, and it might be necessary to retry.
1660                  */
1661                 xug->xug_gen = unp_gencnt;
1662                 xug->xug_sogen = so_gencnt;
1663                 xug->xug_count = unp_count;
1664                 error = SYSCTL_OUT(req, xug, sizeof *xug);
1665         }
1666         free(unp_list, M_TEMP);
1667         free(xug, M_TEMP);
1668         return (error);
1669 }
1670
1671 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
1672     (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb",
1673     "List of active local datagram sockets");
1674 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD,
1675     (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb",
1676     "List of active local stream sockets");
1677 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist,
1678     CTLTYPE_OPAQUE | CTLFLAG_RD,
1679     (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb",
1680     "List of active local seqpacket sockets");
1681
1682 static void
1683 unp_shutdown(struct unpcb *unp)
1684 {
1685         struct unpcb *unp2;
1686         struct socket *so;
1687
1688         UNP_LINK_WLOCK_ASSERT();
1689         UNP_PCB_LOCK_ASSERT(unp);
1690
1691         unp2 = unp->unp_conn;
1692         if ((unp->unp_socket->so_type == SOCK_STREAM ||
1693             (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) {
1694                 so = unp2->unp_socket;
1695                 if (so != NULL)
1696                         socantrcvmore(so);
1697         }
1698 }
1699
1700 static void
1701 unp_drop(struct unpcb *unp)
1702 {
1703         struct socket *so = unp->unp_socket;
1704         struct unpcb *unp2;
1705
1706         UNP_LINK_WLOCK_ASSERT();
1707         UNP_PCB_LOCK_ASSERT(unp);
1708
1709         /*
1710          * Regardless of whether the socket's peer dropped the connection
1711          * with this socket by aborting or disconnecting, POSIX requires
1712          * that ECONNRESET is returned.
1713          */
1714         so->so_error = ECONNRESET;
1715         unp2 = unp->unp_conn;
1716         if (unp2 == NULL)
1717                 return;
1718         UNP_PCB_LOCK(unp2);
1719         unp_disconnect(unp, unp2);
1720         UNP_PCB_UNLOCK(unp2);
1721 }
1722
1723 static void
1724 unp_freerights(struct filedescent **fdep, int fdcount)
1725 {
1726         struct file *fp;
1727         int i;
1728
1729         KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount));
1730
1731         for (i = 0; i < fdcount; i++) {
1732                 fp = fdep[i]->fde_file;
1733                 filecaps_free(&fdep[i]->fde_caps);
1734                 unp_discard(fp);
1735         }
1736         free(fdep[0], M_FILECAPS);
1737 }
1738
1739 static int
1740 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags)
1741 {
1742         struct thread *td = curthread;          /* XXX */
1743         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1744         int i;
1745         int *fdp;
1746         struct filedesc *fdesc = td->td_proc->p_fd;
1747         struct filedescent **fdep;
1748         void *data;
1749         socklen_t clen = control->m_len, datalen;
1750         int error, newfds;
1751         u_int newlen;
1752
1753         UNP_LINK_UNLOCK_ASSERT();
1754
1755         error = 0;
1756         if (controlp != NULL) /* controlp == NULL => free control messages */
1757                 *controlp = NULL;
1758         while (cm != NULL) {
1759                 if (sizeof(*cm) > clen || cm->cmsg_len > clen) {
1760                         error = EINVAL;
1761                         break;
1762                 }
1763                 data = CMSG_DATA(cm);
1764                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1765                 if (cm->cmsg_level == SOL_SOCKET
1766                     && cm->cmsg_type == SCM_RIGHTS) {
1767                         newfds = datalen / sizeof(*fdep);
1768                         if (newfds == 0)
1769                                 goto next;
1770                         fdep = data;
1771
1772                         /* If we're not outputting the descriptors free them. */
1773                         if (error || controlp == NULL) {
1774                                 unp_freerights(fdep, newfds);
1775                                 goto next;
1776                         }
1777                         FILEDESC_XLOCK(fdesc);
1778
1779                         /*
1780                          * Now change each pointer to an fd in the global
1781                          * table to an integer that is the index to the local
1782                          * fd table entry that we set up to point to the
1783                          * global one we are transferring.
1784                          */
1785                         newlen = newfds * sizeof(int);
1786                         *controlp = sbcreatecontrol(NULL, newlen,
1787                             SCM_RIGHTS, SOL_SOCKET);
1788                         if (*controlp == NULL) {
1789                                 FILEDESC_XUNLOCK(fdesc);
1790                                 error = E2BIG;
1791                                 unp_freerights(fdep, newfds);
1792                                 goto next;
1793                         }
1794
1795                         fdp = (int *)
1796                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1797                         if (fdallocn(td, 0, fdp, newfds) != 0) {
1798                                 FILEDESC_XUNLOCK(fdesc);
1799                                 error = EMSGSIZE;
1800                                 unp_freerights(fdep, newfds);
1801                                 m_freem(*controlp);
1802                                 *controlp = NULL;
1803                                 goto next;
1804                         }
1805                         for (i = 0; i < newfds; i++, fdp++) {
1806                                 _finstall(fdesc, fdep[i]->fde_file, *fdp,
1807                                     (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0,
1808                                     &fdep[i]->fde_caps);
1809                                 unp_externalize_fp(fdep[i]->fde_file);
1810                         }
1811                         FILEDESC_XUNLOCK(fdesc);
1812                         free(fdep[0], M_FILECAPS);
1813                 } else {
1814                         /* We can just copy anything else across. */
1815                         if (error || controlp == NULL)
1816                                 goto next;
1817                         *controlp = sbcreatecontrol(NULL, datalen,
1818                             cm->cmsg_type, cm->cmsg_level);
1819                         if (*controlp == NULL) {
1820                                 error = ENOBUFS;
1821                                 goto next;
1822                         }
1823                         bcopy(data,
1824                             CMSG_DATA(mtod(*controlp, struct cmsghdr *)),
1825                             datalen);
1826                 }
1827                 controlp = &(*controlp)->m_next;
1828
1829 next:
1830                 if (CMSG_SPACE(datalen) < clen) {
1831                         clen -= CMSG_SPACE(datalen);
1832                         cm = (struct cmsghdr *)
1833                             ((caddr_t)cm + CMSG_SPACE(datalen));
1834                 } else {
1835                         clen = 0;
1836                         cm = NULL;
1837                 }
1838         }
1839
1840         m_freem(control);
1841         return (error);
1842 }
1843
1844 static void
1845 unp_zone_change(void *tag)
1846 {
1847
1848         uma_zone_set_max(unp_zone, maxsockets);
1849 }
1850
1851 static void
1852 unp_init(void)
1853 {
1854
1855 #ifdef VIMAGE
1856         if (!IS_DEFAULT_VNET(curvnet))
1857                 return;
1858 #endif
1859         unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL,
1860             NULL, NULL, UMA_ALIGN_PTR, 0);
1861         if (unp_zone == NULL)
1862                 panic("unp_init");
1863         uma_zone_set_max(unp_zone, maxsockets);
1864         uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached");
1865         EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change,
1866             NULL, EVENTHANDLER_PRI_ANY);
1867         LIST_INIT(&unp_dhead);
1868         LIST_INIT(&unp_shead);
1869         LIST_INIT(&unp_sphead);
1870         SLIST_INIT(&unp_defers);
1871         TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL);
1872         TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL);
1873         UNP_LINK_LOCK_INIT();
1874         UNP_LIST_LOCK_INIT();
1875         UNP_DEFERRED_LOCK_INIT();
1876 }
1877
1878 static int
1879 unp_internalize(struct mbuf **controlp, struct thread *td)
1880 {
1881         struct mbuf *control = *controlp;
1882         struct proc *p = td->td_proc;
1883         struct filedesc *fdesc = p->p_fd;
1884         struct bintime *bt;
1885         struct cmsghdr *cm = mtod(control, struct cmsghdr *);
1886         struct cmsgcred *cmcred;
1887         struct filedescent *fde, **fdep, *fdev;
1888         struct file *fp;
1889         struct timeval *tv;
1890         int i, *fdp;
1891         void *data;
1892         socklen_t clen = control->m_len, datalen;
1893         int error, oldfds;
1894         u_int newlen;
1895
1896         UNP_LINK_UNLOCK_ASSERT();
1897
1898         error = 0;
1899         *controlp = NULL;
1900         while (cm != NULL) {
1901                 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET
1902                     || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) {
1903                         error = EINVAL;
1904                         goto out;
1905                 }
1906                 data = CMSG_DATA(cm);
1907                 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data;
1908
1909                 switch (cm->cmsg_type) {
1910                 /*
1911                  * Fill in credential information.
1912                  */
1913                 case SCM_CREDS:
1914                         *controlp = sbcreatecontrol(NULL, sizeof(*cmcred),
1915                             SCM_CREDS, SOL_SOCKET);
1916                         if (*controlp == NULL) {
1917                                 error = ENOBUFS;
1918                                 goto out;
1919                         }
1920                         cmcred = (struct cmsgcred *)
1921                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1922                         cmcred->cmcred_pid = p->p_pid;
1923                         cmcred->cmcred_uid = td->td_ucred->cr_ruid;
1924                         cmcred->cmcred_gid = td->td_ucred->cr_rgid;
1925                         cmcred->cmcred_euid = td->td_ucred->cr_uid;
1926                         cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups,
1927                             CMGROUP_MAX);
1928                         for (i = 0; i < cmcred->cmcred_ngroups; i++)
1929                                 cmcred->cmcred_groups[i] =
1930                                     td->td_ucred->cr_groups[i];
1931                         break;
1932
1933                 case SCM_RIGHTS:
1934                         oldfds = datalen / sizeof (int);
1935                         if (oldfds == 0)
1936                                 break;
1937                         /*
1938                          * Check that all the FDs passed in refer to legal
1939                          * files.  If not, reject the entire operation.
1940                          */
1941                         fdp = data;
1942                         FILEDESC_SLOCK(fdesc);
1943                         for (i = 0; i < oldfds; i++, fdp++) {
1944                                 fp = fget_locked(fdesc, *fdp);
1945                                 if (fp == NULL) {
1946                                         FILEDESC_SUNLOCK(fdesc);
1947                                         error = EBADF;
1948                                         goto out;
1949                                 }
1950                                 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) {
1951                                         FILEDESC_SUNLOCK(fdesc);
1952                                         error = EOPNOTSUPP;
1953                                         goto out;
1954                                 }
1955
1956                         }
1957
1958                         /*
1959                          * Now replace the integer FDs with pointers to the
1960                          * file structure and capability rights.
1961                          */
1962                         newlen = oldfds * sizeof(fdep[0]);
1963                         *controlp = sbcreatecontrol(NULL, newlen,
1964                             SCM_RIGHTS, SOL_SOCKET);
1965                         if (*controlp == NULL) {
1966                                 FILEDESC_SUNLOCK(fdesc);
1967                                 error = E2BIG;
1968                                 goto out;
1969                         }
1970                         fdp = data;
1971                         fdep = (struct filedescent **)
1972                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1973                         fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS,
1974                             M_WAITOK);
1975                         for (i = 0; i < oldfds; i++, fdev++, fdp++) {
1976                                 fde = &fdesc->fd_ofiles[*fdp];
1977                                 fdep[i] = fdev;
1978                                 fdep[i]->fde_file = fde->fde_file;
1979                                 filecaps_copy(&fde->fde_caps,
1980                                     &fdep[i]->fde_caps, true);
1981                                 unp_internalize_fp(fdep[i]->fde_file);
1982                         }
1983                         FILEDESC_SUNLOCK(fdesc);
1984                         break;
1985
1986                 case SCM_TIMESTAMP:
1987                         *controlp = sbcreatecontrol(NULL, sizeof(*tv),
1988                             SCM_TIMESTAMP, SOL_SOCKET);
1989                         if (*controlp == NULL) {
1990                                 error = ENOBUFS;
1991                                 goto out;
1992                         }
1993                         tv = (struct timeval *)
1994                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
1995                         microtime(tv);
1996                         break;
1997
1998                 case SCM_BINTIME:
1999                         *controlp = sbcreatecontrol(NULL, sizeof(*bt),
2000                             SCM_BINTIME, SOL_SOCKET);
2001                         if (*controlp == NULL) {
2002                                 error = ENOBUFS;
2003                                 goto out;
2004                         }
2005                         bt = (struct bintime *)
2006                             CMSG_DATA(mtod(*controlp, struct cmsghdr *));
2007                         bintime(bt);
2008                         break;
2009
2010                 default:
2011                         error = EINVAL;
2012                         goto out;
2013                 }
2014
2015                 controlp = &(*controlp)->m_next;
2016                 if (CMSG_SPACE(datalen) < clen) {
2017                         clen -= CMSG_SPACE(datalen);
2018                         cm = (struct cmsghdr *)
2019                             ((caddr_t)cm + CMSG_SPACE(datalen));
2020                 } else {
2021                         clen = 0;
2022                         cm = NULL;
2023                 }
2024         }
2025
2026 out:
2027         m_freem(control);
2028         return (error);
2029 }
2030
2031 static struct mbuf *
2032 unp_addsockcred(struct thread *td, struct mbuf *control)
2033 {
2034         struct mbuf *m, *n, *n_prev;
2035         struct sockcred *sc;
2036         const struct cmsghdr *cm;
2037         int ngroups;
2038         int i;
2039
2040         ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX);
2041         m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET);
2042         if (m == NULL)
2043                 return (control);
2044
2045         sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *));
2046         sc->sc_uid = td->td_ucred->cr_ruid;
2047         sc->sc_euid = td->td_ucred->cr_uid;
2048         sc->sc_gid = td->td_ucred->cr_rgid;
2049         sc->sc_egid = td->td_ucred->cr_gid;
2050         sc->sc_ngroups = ngroups;
2051         for (i = 0; i < sc->sc_ngroups; i++)
2052                 sc->sc_groups[i] = td->td_ucred->cr_groups[i];
2053
2054         /*
2055          * Unlink SCM_CREDS control messages (struct cmsgcred), since just
2056          * created SCM_CREDS control message (struct sockcred) has another
2057          * format.
2058          */
2059         if (control != NULL)
2060                 for (n = control, n_prev = NULL; n != NULL;) {
2061                         cm = mtod(n, struct cmsghdr *);
2062                         if (cm->cmsg_level == SOL_SOCKET &&
2063                             cm->cmsg_type == SCM_CREDS) {
2064                                 if (n_prev == NULL)
2065                                         control = n->m_next;
2066                                 else
2067                                         n_prev->m_next = n->m_next;
2068                                 n = m_free(n);
2069                         } else {
2070                                 n_prev = n;
2071                                 n = n->m_next;
2072                         }
2073                 }
2074
2075         /* Prepend it to the head. */
2076         m->m_next = control;
2077         return (m);
2078 }
2079
2080 static struct unpcb *
2081 fptounp(struct file *fp)
2082 {
2083         struct socket *so;
2084
2085         if (fp->f_type != DTYPE_SOCKET)
2086                 return (NULL);
2087         if ((so = fp->f_data) == NULL)
2088                 return (NULL);
2089         if (so->so_proto->pr_domain != &localdomain)
2090                 return (NULL);
2091         return sotounpcb(so);
2092 }
2093
2094 static void
2095 unp_discard(struct file *fp)
2096 {
2097         struct unp_defer *dr;
2098
2099         if (unp_externalize_fp(fp)) {
2100                 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK);
2101                 dr->ud_fp = fp;
2102                 UNP_DEFERRED_LOCK();
2103                 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link);
2104                 UNP_DEFERRED_UNLOCK();
2105                 atomic_add_int(&unp_defers_count, 1);
2106                 taskqueue_enqueue(taskqueue_thread, &unp_defer_task);
2107         } else
2108                 (void) closef(fp, (struct thread *)NULL);
2109 }
2110
2111 static void
2112 unp_process_defers(void *arg __unused, int pending)
2113 {
2114         struct unp_defer *dr;
2115         SLIST_HEAD(, unp_defer) drl;
2116         int count;
2117
2118         SLIST_INIT(&drl);
2119         for (;;) {
2120                 UNP_DEFERRED_LOCK();
2121                 if (SLIST_FIRST(&unp_defers) == NULL) {
2122                         UNP_DEFERRED_UNLOCK();
2123                         break;
2124                 }
2125                 SLIST_SWAP(&unp_defers, &drl, unp_defer);
2126                 UNP_DEFERRED_UNLOCK();
2127                 count = 0;
2128                 while ((dr = SLIST_FIRST(&drl)) != NULL) {
2129                         SLIST_REMOVE_HEAD(&drl, ud_link);
2130                         closef(dr->ud_fp, NULL);
2131                         free(dr, M_TEMP);
2132                         count++;
2133                 }
2134                 atomic_add_int(&unp_defers_count, -count);
2135         }
2136 }
2137
2138 static void
2139 unp_internalize_fp(struct file *fp)
2140 {
2141         struct unpcb *unp;
2142
2143         UNP_LINK_WLOCK();
2144         if ((unp = fptounp(fp)) != NULL) {
2145                 unp->unp_file = fp;
2146                 unp->unp_msgcount++;
2147         }
2148         fhold(fp);
2149         unp_rights++;
2150         UNP_LINK_WUNLOCK();
2151 }
2152
2153 static int
2154 unp_externalize_fp(struct file *fp)
2155 {
2156         struct unpcb *unp;
2157         int ret;
2158
2159         UNP_LINK_WLOCK();
2160         if ((unp = fptounp(fp)) != NULL) {
2161                 unp->unp_msgcount--;
2162                 ret = 1;
2163         } else
2164                 ret = 0;
2165         unp_rights--;
2166         UNP_LINK_WUNLOCK();
2167         return (ret);
2168 }
2169
2170 /*
2171  * unp_defer indicates whether additional work has been defered for a future
2172  * pass through unp_gc().  It is thread local and does not require explicit
2173  * synchronization.
2174  */
2175 static int      unp_marked;
2176 static int      unp_unreachable;
2177
2178 static void
2179 unp_accessable(struct filedescent **fdep, int fdcount)
2180 {
2181         struct unpcb *unp;
2182         struct file *fp;
2183         int i;
2184
2185         for (i = 0; i < fdcount; i++) {
2186                 fp = fdep[i]->fde_file;
2187                 if ((unp = fptounp(fp)) == NULL)
2188                         continue;
2189                 if (unp->unp_gcflag & UNPGC_REF)
2190                         continue;
2191                 unp->unp_gcflag &= ~UNPGC_DEAD;
2192                 unp->unp_gcflag |= UNPGC_REF;
2193                 unp_marked++;
2194         }
2195 }
2196
2197 static void
2198 unp_gc_process(struct unpcb *unp)
2199 {
2200         struct socket *soa;
2201         struct socket *so;
2202         struct file *fp;
2203
2204         /* Already processed. */
2205         if (unp->unp_gcflag & UNPGC_SCANNED)
2206                 return;
2207         fp = unp->unp_file;
2208
2209         /*
2210          * Check for a socket potentially in a cycle.  It must be in a
2211          * queue as indicated by msgcount, and this must equal the file
2212          * reference count.  Note that when msgcount is 0 the file is NULL.
2213          */
2214         if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp &&
2215             unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) {
2216                 unp->unp_gcflag |= UNPGC_DEAD;
2217                 unp_unreachable++;
2218                 return;
2219         }
2220
2221         /*
2222          * Mark all sockets we reference with RIGHTS.
2223          */
2224         so = unp->unp_socket;
2225         if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) {
2226                 SOCKBUF_LOCK(&so->so_rcv);
2227                 unp_scan(so->so_rcv.sb_mb, unp_accessable);
2228                 SOCKBUF_UNLOCK(&so->so_rcv);
2229         }
2230
2231         /*
2232          * Mark all sockets in our accept queue.
2233          */
2234         ACCEPT_LOCK();
2235         TAILQ_FOREACH(soa, &so->so_comp, so_list) {
2236                 if ((sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) != 0)
2237                         continue;
2238                 SOCKBUF_LOCK(&soa->so_rcv);
2239                 unp_scan(soa->so_rcv.sb_mb, unp_accessable);
2240                 SOCKBUF_UNLOCK(&soa->so_rcv);
2241         }
2242         ACCEPT_UNLOCK();
2243         unp->unp_gcflag |= UNPGC_SCANNED;
2244 }
2245
2246 static int unp_recycled;
2247 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0,
2248     "Number of unreachable sockets claimed by the garbage collector.");
2249
2250 static int unp_taskcount;
2251 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0,
2252     "Number of times the garbage collector has run.");
2253
2254 static void
2255 unp_gc(__unused void *arg, int pending)
2256 {
2257         struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead,
2258                                     NULL };
2259         struct unp_head **head;
2260         struct file *f, **unref;
2261         struct unpcb *unp;
2262         int i, total;
2263
2264         unp_taskcount++;
2265         UNP_LIST_LOCK();
2266         /*
2267          * First clear all gc flags from previous runs, apart from
2268          * UNPGC_IGNORE_RIGHTS.
2269          */
2270         for (head = heads; *head != NULL; head++)
2271                 LIST_FOREACH(unp, *head, unp_link)
2272                         unp->unp_gcflag =
2273                             (unp->unp_gcflag & UNPGC_IGNORE_RIGHTS);
2274
2275         /*
2276          * Scan marking all reachable sockets with UNPGC_REF.  Once a socket
2277          * is reachable all of the sockets it references are reachable.
2278          * Stop the scan once we do a complete loop without discovering
2279          * a new reachable socket.
2280          */
2281         do {
2282                 unp_unreachable = 0;
2283                 unp_marked = 0;
2284                 for (head = heads; *head != NULL; head++)
2285                         LIST_FOREACH(unp, *head, unp_link)
2286                                 unp_gc_process(unp);
2287         } while (unp_marked);
2288         UNP_LIST_UNLOCK();
2289         if (unp_unreachable == 0)
2290                 return;
2291
2292         /*
2293          * Allocate space for a local list of dead unpcbs.
2294          */
2295         unref = malloc(unp_unreachable * sizeof(struct file *),
2296             M_TEMP, M_WAITOK);
2297
2298         /*
2299          * Iterate looking for sockets which have been specifically marked
2300          * as as unreachable and store them locally.
2301          */
2302         UNP_LINK_RLOCK();
2303         UNP_LIST_LOCK();
2304         for (total = 0, head = heads; *head != NULL; head++)
2305                 LIST_FOREACH(unp, *head, unp_link)
2306                         if ((unp->unp_gcflag & UNPGC_DEAD) != 0) {
2307                                 f = unp->unp_file;
2308                                 if (unp->unp_msgcount == 0 || f == NULL ||
2309                                     f->f_count != unp->unp_msgcount)
2310                                         continue;
2311                                 unref[total++] = f;
2312                                 fhold(f);
2313                                 KASSERT(total <= unp_unreachable,
2314                                     ("unp_gc: incorrect unreachable count."));
2315                         }
2316         UNP_LIST_UNLOCK();
2317         UNP_LINK_RUNLOCK();
2318
2319         /*
2320          * Now flush all sockets, free'ing rights.  This will free the
2321          * struct files associated with these sockets but leave each socket
2322          * with one remaining ref.
2323          */
2324         for (i = 0; i < total; i++) {
2325                 struct socket *so;
2326
2327                 so = unref[i]->f_data;
2328                 CURVNET_SET(so->so_vnet);
2329                 sorflush(so);
2330                 CURVNET_RESTORE();
2331         }
2332
2333         /*
2334          * And finally release the sockets so they can be reclaimed.
2335          */
2336         for (i = 0; i < total; i++)
2337                 fdrop(unref[i], NULL);
2338         unp_recycled += total;
2339         free(unref, M_TEMP);
2340 }
2341
2342 static void
2343 unp_dispose(struct mbuf *m)
2344 {
2345
2346         if (m)
2347                 unp_scan(m, unp_freerights);
2348 }
2349
2350 /*
2351  * Synchronize against unp_gc, which can trip over data as we are freeing it.
2352  */
2353 static void
2354 unp_dispose_so(struct socket *so)
2355 {
2356         struct unpcb *unp;
2357
2358         unp = sotounpcb(so);
2359         UNP_LIST_LOCK();
2360         unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS;
2361         UNP_LIST_UNLOCK();
2362         unp_dispose(so->so_rcv.sb_mb);
2363 }
2364
2365 static void
2366 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int))
2367 {
2368         struct mbuf *m;
2369         struct cmsghdr *cm;
2370         void *data;
2371         socklen_t clen, datalen;
2372
2373         while (m0 != NULL) {
2374                 for (m = m0; m; m = m->m_next) {
2375                         if (m->m_type != MT_CONTROL)
2376                                 continue;
2377
2378                         cm = mtod(m, struct cmsghdr *);
2379                         clen = m->m_len;
2380
2381                         while (cm != NULL) {
2382                                 if (sizeof(*cm) > clen || cm->cmsg_len > clen)
2383                                         break;
2384
2385                                 data = CMSG_DATA(cm);
2386                                 datalen = (caddr_t)cm + cm->cmsg_len
2387                                     - (caddr_t)data;
2388
2389                                 if (cm->cmsg_level == SOL_SOCKET &&
2390                                     cm->cmsg_type == SCM_RIGHTS) {
2391                                         (*op)(data, datalen /
2392                                             sizeof(struct filedescent *));
2393                                 }
2394
2395                                 if (CMSG_SPACE(datalen) < clen) {
2396                                         clen -= CMSG_SPACE(datalen);
2397                                         cm = (struct cmsghdr *)
2398                                             ((caddr_t)cm + CMSG_SPACE(datalen));
2399                                 } else {
2400                                         clen = 0;
2401                                         cm = NULL;
2402                                 }
2403                         }
2404                 }
2405                 m0 = m0->m_nextpkt;
2406         }
2407 }
2408
2409 /*
2410  * A helper function called by VFS before socket-type vnode reclamation.
2411  * For an active vnode it clears unp_vnode pointer and decrements unp_vnode
2412  * use count.
2413  */
2414 void
2415 vfs_unp_reclaim(struct vnode *vp)
2416 {
2417         struct socket *so;
2418         struct unpcb *unp;
2419         int active;
2420
2421         ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim");
2422         KASSERT(vp->v_type == VSOCK,
2423             ("vfs_unp_reclaim: vp->v_type != VSOCK"));
2424
2425         active = 0;
2426         UNP_LINK_WLOCK();
2427         VOP_UNP_CONNECT(vp, &so);
2428         if (so == NULL)
2429                 goto done;
2430         unp = sotounpcb(so);
2431         if (unp == NULL)
2432                 goto done;
2433         UNP_PCB_LOCK(unp);
2434         if (unp->unp_vnode == vp) {
2435                 VOP_UNP_DETACH(vp);
2436                 unp->unp_vnode = NULL;
2437                 active = 1;
2438         }
2439         UNP_PCB_UNLOCK(unp);
2440 done:
2441         UNP_LINK_WUNLOCK();
2442         if (active)
2443                 vunref(vp);
2444 }
2445
2446 #ifdef DDB
2447 static void
2448 db_print_indent(int indent)
2449 {
2450         int i;
2451
2452         for (i = 0; i < indent; i++)
2453                 db_printf(" ");
2454 }
2455
2456 static void
2457 db_print_unpflags(int unp_flags)
2458 {
2459         int comma;
2460
2461         comma = 0;
2462         if (unp_flags & UNP_HAVEPC) {
2463                 db_printf("%sUNP_HAVEPC", comma ? ", " : "");
2464                 comma = 1;
2465         }
2466         if (unp_flags & UNP_HAVEPCCACHED) {
2467                 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : "");
2468                 comma = 1;
2469         }
2470         if (unp_flags & UNP_WANTCRED) {
2471                 db_printf("%sUNP_WANTCRED", comma ? ", " : "");
2472                 comma = 1;
2473         }
2474         if (unp_flags & UNP_CONNWAIT) {
2475                 db_printf("%sUNP_CONNWAIT", comma ? ", " : "");
2476                 comma = 1;
2477         }
2478         if (unp_flags & UNP_CONNECTING) {
2479                 db_printf("%sUNP_CONNECTING", comma ? ", " : "");
2480                 comma = 1;
2481         }
2482         if (unp_flags & UNP_BINDING) {
2483                 db_printf("%sUNP_BINDING", comma ? ", " : "");
2484                 comma = 1;
2485         }
2486 }
2487
2488 static void
2489 db_print_xucred(int indent, struct xucred *xu)
2490 {
2491         int comma, i;
2492
2493         db_print_indent(indent);
2494         db_printf("cr_version: %u   cr_uid: %u   cr_ngroups: %d\n",
2495             xu->cr_version, xu->cr_uid, xu->cr_ngroups);
2496         db_print_indent(indent);
2497         db_printf("cr_groups: ");
2498         comma = 0;
2499         for (i = 0; i < xu->cr_ngroups; i++) {
2500                 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]);
2501                 comma = 1;
2502         }
2503         db_printf("\n");
2504 }
2505
2506 static void
2507 db_print_unprefs(int indent, struct unp_head *uh)
2508 {
2509         struct unpcb *unp;
2510         int counter;
2511
2512         counter = 0;
2513         LIST_FOREACH(unp, uh, unp_reflink) {
2514                 if (counter % 4 == 0)
2515                         db_print_indent(indent);
2516                 db_printf("%p  ", unp);
2517                 if (counter % 4 == 3)
2518                         db_printf("\n");
2519                 counter++;
2520         }
2521         if (counter != 0 && counter % 4 != 0)
2522                 db_printf("\n");
2523 }
2524
2525 DB_SHOW_COMMAND(unpcb, db_show_unpcb)
2526 {
2527         struct unpcb *unp;
2528
2529         if (!have_addr) {
2530                 db_printf("usage: show unpcb <addr>\n");
2531                 return;
2532         }
2533         unp = (struct unpcb *)addr;
2534
2535         db_printf("unp_socket: %p   unp_vnode: %p\n", unp->unp_socket,
2536             unp->unp_vnode);
2537
2538         db_printf("unp_ino: %ju   unp_conn: %p\n", (uintmax_t)unp->unp_ino,
2539             unp->unp_conn);
2540
2541         db_printf("unp_refs:\n");
2542         db_print_unprefs(2, &unp->unp_refs);
2543
2544         /* XXXRW: Would be nice to print the full address, if any. */
2545         db_printf("unp_addr: %p\n", unp->unp_addr);
2546
2547         db_printf("unp_gencnt: %llu\n",
2548             (unsigned long long)unp->unp_gencnt);
2549
2550         db_printf("unp_flags: %x (", unp->unp_flags);
2551         db_print_unpflags(unp->unp_flags);
2552         db_printf(")\n");
2553
2554         db_printf("unp_peercred:\n");
2555         db_print_xucred(2, &unp->unp_peercred);
2556
2557         db_printf("unp_refcount: %u\n", unp->unp_refcount);
2558 }
2559 #endif