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