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