1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. 6 * Copyright (c) 2004-2009 Robert N. M. Watson 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 34 */ 35 36 /* 37 * UNIX Domain (Local) Sockets 38 * 39 * This is an implementation of UNIX (local) domain sockets. Each socket has 40 * an associated struct unpcb (UNIX protocol control block). Stream sockets 41 * may be connected to 0 or 1 other socket. Datagram sockets may be 42 * connected to 0, 1, or many other sockets. Sockets may be created and 43 * connected in pairs (socketpair(2)), or bound/connected to using the file 44 * system name space. For most purposes, only the receive socket buffer is 45 * used, as sending on one socket delivers directly to the receive socket 46 * buffer of a second socket. 47 * 48 * The implementation is substantially complicated by the fact that 49 * "ancillary data", such as file descriptors or credentials, may be passed 50 * across UNIX domain sockets. The potential for passing UNIX domain sockets 51 * over other UNIX domain sockets requires the implementation of a simple 52 * garbage collector to find and tear down cycles of disconnected sockets. 53 * 54 * TODO: 55 * RDM 56 * rethink name space problems 57 * need a proper out-of-band 58 */ 59 60 #include <sys/cdefs.h> 61 __FBSDID("$FreeBSD$"); 62 63 #include "opt_ddb.h" 64 65 #include <sys/param.h> 66 #include <sys/capsicum.h> 67 #include <sys/domain.h> 68 #include <sys/fcntl.h> 69 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 70 #include <sys/eventhandler.h> 71 #include <sys/file.h> 72 #include <sys/filedesc.h> 73 #include <sys/kernel.h> 74 #include <sys/lock.h> 75 #include <sys/mbuf.h> 76 #include <sys/mount.h> 77 #include <sys/mutex.h> 78 #include <sys/namei.h> 79 #include <sys/proc.h> 80 #include <sys/protosw.h> 81 #include <sys/queue.h> 82 #include <sys/resourcevar.h> 83 #include <sys/rwlock.h> 84 #include <sys/socket.h> 85 #include <sys/socketvar.h> 86 #include <sys/signalvar.h> 87 #include <sys/stat.h> 88 #include <sys/sx.h> 89 #include <sys/sysctl.h> 90 #include <sys/systm.h> 91 #include <sys/taskqueue.h> 92 #include <sys/un.h> 93 #include <sys/unpcb.h> 94 #include <sys/vnode.h> 95 96 #include <net/vnet.h> 97 98 #ifdef DDB 99 #include <ddb/ddb.h> 100 #endif 101 102 #include <security/mac/mac_framework.h> 103 104 #include <vm/uma.h> 105 106 MALLOC_DECLARE(M_FILECAPS); 107 108 /* 109 * Locking key: 110 * (l) Locked using list lock 111 * (g) Locked using linkage lock 112 */ 113 114 static uma_zone_t unp_zone; 115 static unp_gen_t unp_gencnt; /* (l) */ 116 static u_int unp_count; /* (l) Count of local sockets. */ 117 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 118 static int unp_rights; /* (g) File descriptors in flight. */ 119 static struct unp_head unp_shead; /* (l) List of stream sockets. */ 120 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 121 static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */ 122 123 struct unp_defer { 124 SLIST_ENTRY(unp_defer) ud_link; 125 struct file *ud_fp; 126 }; 127 static SLIST_HEAD(, unp_defer) unp_defers; 128 static int unp_defers_count; 129 130 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 131 132 /* 133 * Garbage collection of cyclic file descriptor/socket references occurs 134 * asynchronously in a taskqueue context in order to avoid recursion and 135 * reentrance in the UNIX domain socket, file descriptor, and socket layer 136 * code. See unp_gc() for a full description. 137 */ 138 static struct timeout_task unp_gc_task; 139 140 /* 141 * The close of unix domain sockets attached as SCM_RIGHTS is 142 * postponed to the taskqueue, to avoid arbitrary recursion depth. 143 * The attached sockets might have another sockets attached. 144 */ 145 static struct task unp_defer_task; 146 147 /* 148 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 149 * stream sockets, although the total for sender and receiver is actually 150 * only PIPSIZ. 151 * 152 * Datagram sockets really use the sendspace as the maximum datagram size, 153 * and don't really want to reserve the sendspace. Their recvspace should be 154 * large enough for at least one max-size datagram plus address. 155 */ 156 #ifndef PIPSIZ 157 #define PIPSIZ 8192 158 #endif 159 static u_long unpst_sendspace = PIPSIZ; 160 static u_long unpst_recvspace = PIPSIZ; 161 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 162 static u_long unpdg_recvspace = 4*1024; 163 static u_long unpsp_sendspace = PIPSIZ; /* really max datagram size */ 164 static u_long unpsp_recvspace = PIPSIZ; 165 166 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain"); 167 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, 168 "SOCK_STREAM"); 169 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM"); 170 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, CTLFLAG_RW, 0, 171 "SOCK_SEQPACKET"); 172 173 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 174 &unpst_sendspace, 0, "Default stream send space."); 175 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 176 &unpst_recvspace, 0, "Default stream receive space."); 177 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 178 &unpdg_sendspace, 0, "Default datagram send space."); 179 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 180 &unpdg_recvspace, 0, "Default datagram receive space."); 181 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW, 182 &unpsp_sendspace, 0, "Default seqpacket send space."); 183 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW, 184 &unpsp_recvspace, 0, "Default seqpacket receive space."); 185 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 186 "File descriptors in flight."); 187 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD, 188 &unp_defers_count, 0, 189 "File descriptors deferred to taskqueue for close."); 190 191 /* 192 * Locking and synchronization: 193 * 194 * Three types of locks exist in the local domain socket implementation: a 195 * a global linkage rwlock, the mtxpool lock, and per-unpcb mutexes. 196 * The linkage lock protects the socket count, global generation number, 197 * and stream/datagram global lists. 198 * 199 * The mtxpool lock protects the vnode from being modified while referenced. 200 * Lock ordering requires that it be acquired before any unpcb locks. 201 * 202 * The unpcb lock (unp_mtx) protects all fields in the unpcb. Of particular 203 * note is that this includes the unp_conn field. So long as the unpcb lock 204 * is held the reference to the unpcb pointed to by unp_conn is valid. If we 205 * require that the unpcb pointed to by unp_conn remain live in cases where 206 * we need to drop the unp_mtx as when we need to acquire the lock for a 207 * second unpcb the caller must first acquire an additional reference on the 208 * second unpcb and then revalidate any state (typically check that unp_conn 209 * is non-NULL) upon requiring the initial unpcb lock. The lock ordering 210 * between unpcbs is the conventional ascending address order. Two helper 211 * routines exist for this: 212 * 213 * - unp_pcb_lock2(unp, unp2) - which just acquires the two locks in the 214 * safe ordering. 215 * 216 * - unp_pcb_owned_lock2(unp, unp2, freed) - the lock for unp is held 217 * when called. If unp is unlocked and unp2 is subsequently freed 218 * freed will be set to 1. 219 * 220 * The helper routines for references are: 221 * 222 * - unp_pcb_hold(unp): Can be called any time we currently hold a valid 223 * reference to unp. 224 * 225 * - unp_pcb_rele(unp): The caller must hold the unp lock. If we are 226 * releasing the last reference, detach must have been called thus 227 * unp->unp_socket be NULL. 228 * 229 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 230 * allocated in pru_attach() and freed in pru_detach(). The validity of that 231 * pointer is an invariant, so no lock is required to dereference the so_pcb 232 * pointer if a valid socket reference is held by the caller. In practice, 233 * this is always true during operations performed on a socket. Each unpcb 234 * has a back-pointer to its socket, unp_socket, which will be stable under 235 * the same circumstances. 236 * 237 * This pointer may only be safely dereferenced as long as a valid reference 238 * to the unpcb is held. Typically, this reference will be from the socket, 239 * or from another unpcb when the referring unpcb's lock is held (in order 240 * that the reference not be invalidated during use). For example, to follow 241 * unp->unp_conn->unp_socket, you need to hold a lock on unp_conn to guarantee 242 * that detach is not run clearing unp_socket. 243 * 244 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 245 * protocols, bind() is a non-atomic operation, and connect() requires 246 * potential sleeping in the protocol, due to potentially waiting on local or 247 * distributed file systems. We try to separate "lookup" operations, which 248 * may sleep, and the IPC operations themselves, which typically can occur 249 * with relative atomicity as locks can be held over the entire operation. 250 * 251 * Another tricky issue is simultaneous multi-threaded or multi-process 252 * access to a single UNIX domain socket. These are handled by the flags 253 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 254 * binding, both of which involve dropping UNIX domain socket locks in order 255 * to perform namei() and other file system operations. 256 */ 257 static struct rwlock unp_link_rwlock; 258 static struct mtx unp_defers_lock; 259 260 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 261 "unp_link_rwlock") 262 263 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 264 RA_LOCKED) 265 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 266 RA_UNLOCKED) 267 268 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 269 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 270 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 271 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 272 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 273 RA_WLOCKED) 274 #define UNP_LINK_WOWNED() rw_wowned(&unp_link_rwlock) 275 276 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \ 277 "unp_defer", NULL, MTX_DEF) 278 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock) 279 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock) 280 281 #define UNP_REF_LIST_LOCK() UNP_DEFERRED_LOCK(); 282 #define UNP_REF_LIST_UNLOCK() UNP_DEFERRED_UNLOCK(); 283 284 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 285 "unp_mtx", "unp_mtx", \ 286 MTX_DUPOK|MTX_DEF) 287 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 288 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 289 #define UNP_PCB_TRYLOCK(unp) mtx_trylock(&(unp)->unp_mtx) 290 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 291 #define UNP_PCB_OWNED(unp) mtx_owned(&(unp)->unp_mtx) 292 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 293 #define UNP_PCB_UNLOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_NOTOWNED) 294 295 static int uipc_connect2(struct socket *, struct socket *); 296 static int uipc_ctloutput(struct socket *, struct sockopt *); 297 static int unp_connect(struct socket *, struct sockaddr *, 298 struct thread *); 299 static int unp_connectat(int, struct socket *, struct sockaddr *, 300 struct thread *); 301 static int unp_connect2(struct socket *so, struct socket *so2, int); 302 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 303 static void unp_dispose(struct socket *so); 304 static void unp_dispose_mbuf(struct mbuf *); 305 static void unp_shutdown(struct unpcb *); 306 static void unp_drop(struct unpcb *); 307 static void unp_gc(__unused void *, int); 308 static void unp_scan(struct mbuf *, void (*)(struct filedescent **, int)); 309 static void unp_discard(struct file *); 310 static void unp_freerights(struct filedescent **, int); 311 static void unp_init(void); 312 static int unp_internalize(struct mbuf **, struct thread *); 313 static void unp_internalize_fp(struct file *); 314 static int unp_externalize(struct mbuf *, struct mbuf **, int); 315 static int unp_externalize_fp(struct file *); 316 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 317 static void unp_process_defers(void * __unused, int); 318 319 320 static void 321 unp_pcb_hold(struct unpcb *unp) 322 { 323 MPASS(unp->unp_refcount); 324 refcount_acquire(&unp->unp_refcount); 325 } 326 327 static int 328 unp_pcb_rele(struct unpcb *unp) 329 { 330 int freed; 331 332 UNP_PCB_LOCK_ASSERT(unp); 333 MPASS(unp->unp_refcount); 334 if ((freed = refcount_release(&unp->unp_refcount))) { 335 /* we got here with having detached? */ 336 MPASS(unp->unp_socket == NULL); 337 UNP_PCB_UNLOCK(unp); 338 UNP_PCB_LOCK_DESTROY(unp); 339 uma_zfree(unp_zone, unp); 340 } 341 return (freed); 342 } 343 344 static void 345 unp_pcb_lock2(struct unpcb *unp, struct unpcb *unp2) 346 { 347 UNP_PCB_UNLOCK_ASSERT(unp); 348 UNP_PCB_UNLOCK_ASSERT(unp2); 349 if ((uintptr_t)unp2 > (uintptr_t)unp) { 350 UNP_PCB_LOCK(unp); 351 UNP_PCB_LOCK(unp2); 352 } else { 353 UNP_PCB_LOCK(unp2); 354 UNP_PCB_LOCK(unp); 355 } 356 } 357 358 static __noinline void 359 unp_pcb_owned_lock2_slowpath(struct unpcb *unp, struct unpcb **unp2p, int *freed) 360 361 { 362 struct unpcb *unp2; 363 364 unp2 = *unp2p; 365 unp_pcb_hold((unp2)); 366 UNP_PCB_UNLOCK((unp)); 367 UNP_PCB_LOCK((unp2)); 368 UNP_PCB_LOCK((unp)); 369 *freed = unp_pcb_rele((unp2)); 370 if (*freed) 371 *unp2p = NULL; 372 } 373 374 #define unp_pcb_owned_lock2(unp, unp2, freed) do { \ 375 freed = 0; \ 376 UNP_PCB_LOCK_ASSERT((unp)); \ 377 UNP_PCB_UNLOCK_ASSERT((unp2)); \ 378 if (__predict_true(UNP_PCB_TRYLOCK((unp2)))) \ 379 break; \ 380 else if ((uintptr_t)(unp2) > (uintptr_t)(unp)) \ 381 UNP_PCB_LOCK((unp2)); \ 382 else { \ 383 unp_pcb_owned_lock2_slowpath((unp), &(unp2), &freed); \ 384 } \ 385 } while (0) 386 387 388 /* 389 * Definitions of protocols supported in the LOCAL domain. 390 */ 391 static struct domain localdomain; 392 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 393 static struct pr_usrreqs uipc_usrreqs_seqpacket; 394 static struct protosw localsw[] = { 395 { 396 .pr_type = SOCK_STREAM, 397 .pr_domain = &localdomain, 398 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 399 .pr_ctloutput = &uipc_ctloutput, 400 .pr_usrreqs = &uipc_usrreqs_stream 401 }, 402 { 403 .pr_type = SOCK_DGRAM, 404 .pr_domain = &localdomain, 405 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 406 .pr_ctloutput = &uipc_ctloutput, 407 .pr_usrreqs = &uipc_usrreqs_dgram 408 }, 409 { 410 .pr_type = SOCK_SEQPACKET, 411 .pr_domain = &localdomain, 412 413 /* 414 * XXXRW: For now, PR_ADDR because soreceive will bump into them 415 * due to our use of sbappendaddr. A new sbappend variants is needed 416 * that supports both atomic record writes and control data. 417 */ 418 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD| 419 PR_RIGHTS, 420 .pr_ctloutput = &uipc_ctloutput, 421 .pr_usrreqs = &uipc_usrreqs_seqpacket, 422 }, 423 }; 424 425 static struct domain localdomain = { 426 .dom_family = AF_LOCAL, 427 .dom_name = "local", 428 .dom_init = unp_init, 429 .dom_externalize = unp_externalize, 430 .dom_dispose = unp_dispose, 431 .dom_protosw = localsw, 432 .dom_protoswNPROTOSW = &localsw[nitems(localsw)] 433 }; 434 DOMAIN_SET(local); 435 436 static void 437 uipc_abort(struct socket *so) 438 { 439 struct unpcb *unp, *unp2; 440 441 unp = sotounpcb(so); 442 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 443 UNP_PCB_UNLOCK_ASSERT(unp); 444 445 UNP_PCB_LOCK(unp); 446 unp2 = unp->unp_conn; 447 if (unp2 != NULL) { 448 unp_pcb_hold(unp2); 449 UNP_PCB_UNLOCK(unp); 450 unp_drop(unp2); 451 } else 452 UNP_PCB_UNLOCK(unp); 453 } 454 455 static int 456 uipc_accept(struct socket *so, struct sockaddr **nam) 457 { 458 struct unpcb *unp, *unp2; 459 const struct sockaddr *sa; 460 461 /* 462 * Pass back name of connected socket, if it was bound and we are 463 * still connected (our peer may have closed already!). 464 */ 465 unp = sotounpcb(so); 466 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 467 468 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 469 UNP_LINK_RLOCK(); 470 unp2 = unp->unp_conn; 471 if (unp2 != NULL && unp2->unp_addr != NULL) { 472 UNP_PCB_LOCK(unp2); 473 sa = (struct sockaddr *) unp2->unp_addr; 474 bcopy(sa, *nam, sa->sa_len); 475 UNP_PCB_UNLOCK(unp2); 476 } else { 477 sa = &sun_noname; 478 bcopy(sa, *nam, sa->sa_len); 479 } 480 UNP_LINK_RUNLOCK(); 481 return (0); 482 } 483 484 static int 485 uipc_attach(struct socket *so, int proto, struct thread *td) 486 { 487 u_long sendspace, recvspace; 488 struct unpcb *unp; 489 int error; 490 bool locked; 491 492 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 493 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 494 switch (so->so_type) { 495 case SOCK_STREAM: 496 sendspace = unpst_sendspace; 497 recvspace = unpst_recvspace; 498 break; 499 500 case SOCK_DGRAM: 501 sendspace = unpdg_sendspace; 502 recvspace = unpdg_recvspace; 503 break; 504 505 case SOCK_SEQPACKET: 506 sendspace = unpsp_sendspace; 507 recvspace = unpsp_recvspace; 508 break; 509 510 default: 511 panic("uipc_attach"); 512 } 513 error = soreserve(so, sendspace, recvspace); 514 if (error) 515 return (error); 516 } 517 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 518 if (unp == NULL) 519 return (ENOBUFS); 520 LIST_INIT(&unp->unp_refs); 521 UNP_PCB_LOCK_INIT(unp); 522 unp->unp_socket = so; 523 so->so_pcb = unp; 524 unp->unp_refcount = 1; 525 if (so->so_listen != NULL) 526 unp->unp_flags |= UNP_NASCENT; 527 528 if ((locked = UNP_LINK_WOWNED()) == false) 529 UNP_LINK_WLOCK(); 530 531 unp->unp_gencnt = ++unp_gencnt; 532 unp_count++; 533 switch (so->so_type) { 534 case SOCK_STREAM: 535 LIST_INSERT_HEAD(&unp_shead, unp, unp_link); 536 break; 537 538 case SOCK_DGRAM: 539 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link); 540 break; 541 542 case SOCK_SEQPACKET: 543 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link); 544 break; 545 546 default: 547 panic("uipc_attach"); 548 } 549 550 if (locked == false) 551 UNP_LINK_WUNLOCK(); 552 553 return (0); 554 } 555 556 static int 557 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td) 558 { 559 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 560 struct vattr vattr; 561 int error, namelen; 562 struct nameidata nd; 563 struct unpcb *unp; 564 struct vnode *vp; 565 struct mount *mp; 566 cap_rights_t rights; 567 char *buf; 568 569 if (nam->sa_family != AF_UNIX) 570 return (EAFNOSUPPORT); 571 572 unp = sotounpcb(so); 573 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 574 575 if (soun->sun_len > sizeof(struct sockaddr_un)) 576 return (EINVAL); 577 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 578 if (namelen <= 0) 579 return (EINVAL); 580 581 /* 582 * We don't allow simultaneous bind() calls on a single UNIX domain 583 * socket, so flag in-progress operations, and return an error if an 584 * operation is already in progress. 585 * 586 * Historically, we have not allowed a socket to be rebound, so this 587 * also returns an error. Not allowing re-binding simplifies the 588 * implementation and avoids a great many possible failure modes. 589 */ 590 UNP_PCB_LOCK(unp); 591 if (unp->unp_vnode != NULL) { 592 UNP_PCB_UNLOCK(unp); 593 return (EINVAL); 594 } 595 if (unp->unp_flags & UNP_BINDING) { 596 UNP_PCB_UNLOCK(unp); 597 return (EALREADY); 598 } 599 unp->unp_flags |= UNP_BINDING; 600 UNP_PCB_UNLOCK(unp); 601 602 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 603 bcopy(soun->sun_path, buf, namelen); 604 buf[namelen] = 0; 605 606 restart: 607 NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE, 608 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td); 609 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 610 error = namei(&nd); 611 if (error) 612 goto error; 613 vp = nd.ni_vp; 614 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 615 NDFREE(&nd, NDF_ONLY_PNBUF); 616 if (nd.ni_dvp == vp) 617 vrele(nd.ni_dvp); 618 else 619 vput(nd.ni_dvp); 620 if (vp != NULL) { 621 vrele(vp); 622 error = EADDRINUSE; 623 goto error; 624 } 625 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 626 if (error) 627 goto error; 628 goto restart; 629 } 630 VATTR_NULL(&vattr); 631 vattr.va_type = VSOCK; 632 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 633 #ifdef MAC 634 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 635 &vattr); 636 #endif 637 if (error == 0) 638 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 639 NDFREE(&nd, NDF_ONLY_PNBUF); 640 vput(nd.ni_dvp); 641 if (error) { 642 vn_finished_write(mp); 643 goto error; 644 } 645 vp = nd.ni_vp; 646 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 647 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 648 649 UNP_PCB_LOCK(unp); 650 VOP_UNP_BIND(vp, unp); 651 unp->unp_vnode = vp; 652 unp->unp_addr = soun; 653 unp->unp_flags &= ~UNP_BINDING; 654 UNP_PCB_UNLOCK(unp); 655 VOP_UNLOCK(vp, 0); 656 vn_finished_write(mp); 657 free(buf, M_TEMP); 658 return (0); 659 660 error: 661 UNP_PCB_LOCK(unp); 662 unp->unp_flags &= ~UNP_BINDING; 663 UNP_PCB_UNLOCK(unp); 664 free(buf, M_TEMP); 665 return (error); 666 } 667 668 static int 669 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 670 { 671 672 return (uipc_bindat(AT_FDCWD, so, nam, td)); 673 } 674 675 static int 676 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 677 { 678 int error; 679 680 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 681 error = unp_connect(so, nam, td); 682 return (error); 683 } 684 685 static int 686 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 687 struct thread *td) 688 { 689 int error; 690 691 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 692 error = unp_connectat(fd, so, nam, td); 693 return (error); 694 } 695 696 static void 697 uipc_close(struct socket *so) 698 { 699 struct unpcb *unp, *unp2; 700 struct vnode *vp = NULL; 701 struct mtx *vplock; 702 int freed; 703 unp = sotounpcb(so); 704 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 705 706 707 vplock = NULL; 708 if ((vp = unp->unp_vnode) != NULL) { 709 vplock = mtx_pool_find(mtxpool_sleep, vp); 710 mtx_lock(vplock); 711 } 712 UNP_PCB_LOCK(unp); 713 if (vp && unp->unp_vnode == NULL) { 714 mtx_unlock(vplock); 715 vp = NULL; 716 } 717 if (vp != NULL) { 718 VOP_UNP_DETACH(vp); 719 unp->unp_vnode = NULL; 720 } 721 unp2 = unp->unp_conn; 722 unp_pcb_hold(unp); 723 if (unp2 != NULL) { 724 unp_pcb_hold(unp2); 725 unp_pcb_owned_lock2(unp, unp2, freed); 726 unp_disconnect(unp, unp2); 727 if (unp_pcb_rele(unp2) == 0) 728 UNP_PCB_UNLOCK(unp2); 729 } 730 if (unp_pcb_rele(unp) == 0) 731 UNP_PCB_UNLOCK(unp); 732 if (vp) { 733 mtx_unlock(vplock); 734 vrele(vp); 735 } 736 } 737 738 static int 739 uipc_connect2(struct socket *so1, struct socket *so2) 740 { 741 struct unpcb *unp, *unp2; 742 int error; 743 744 unp = so1->so_pcb; 745 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 746 unp2 = so2->so_pcb; 747 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 748 unp_pcb_lock2(unp, unp2); 749 error = unp_connect2(so1, so2, PRU_CONNECT2); 750 UNP_PCB_UNLOCK(unp2); 751 UNP_PCB_UNLOCK(unp); 752 return (error); 753 } 754 755 static void 756 uipc_detach(struct socket *so) 757 { 758 struct unpcb *unp, *unp2; 759 struct mtx *vplock; 760 struct sockaddr_un *saved_unp_addr; 761 struct vnode *vp; 762 int freeunp, local_unp_rights; 763 764 unp = sotounpcb(so); 765 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 766 767 vp = NULL; 768 local_unp_rights = 0; 769 770 UNP_LINK_WLOCK(); 771 LIST_REMOVE(unp, unp_link); 772 unp->unp_gencnt = ++unp_gencnt; 773 --unp_count; 774 UNP_LINK_WUNLOCK(); 775 776 UNP_PCB_UNLOCK_ASSERT(unp); 777 restart: 778 if ((vp = unp->unp_vnode) != NULL) { 779 vplock = mtx_pool_find(mtxpool_sleep, vp); 780 mtx_lock(vplock); 781 } 782 UNP_PCB_LOCK(unp); 783 if ((unp2 = unp->unp_conn) != NULL) { 784 unp_pcb_owned_lock2(unp, unp2, freeunp); 785 if (freeunp) 786 unp2 = NULL; 787 } 788 if (unp->unp_vnode != vp && 789 unp->unp_vnode != NULL) { 790 mtx_unlock(vplock); 791 UNP_PCB_UNLOCK(unp); 792 if (unp2) 793 UNP_PCB_UNLOCK(unp2); 794 goto restart; 795 } 796 if ((unp->unp_flags & UNP_NASCENT) != 0) { 797 if (unp2) 798 UNP_PCB_UNLOCK(unp2); 799 goto teardown; 800 } 801 if ((vp = unp->unp_vnode) != NULL) { 802 VOP_UNP_DETACH(vp); 803 unp->unp_vnode = NULL; 804 } 805 unp_pcb_hold(unp); 806 if (unp2 != NULL) { 807 unp_pcb_hold(unp2); 808 unp_disconnect(unp, unp2); 809 if (unp_pcb_rele(unp2) == 0) 810 UNP_PCB_UNLOCK(unp2); 811 } 812 UNP_PCB_UNLOCK(unp); 813 UNP_REF_LIST_LOCK(); 814 while (!LIST_EMPTY(&unp->unp_refs)) { 815 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 816 817 unp_pcb_hold(ref); 818 UNP_REF_LIST_UNLOCK(); 819 820 MPASS(ref != unp); 821 UNP_PCB_UNLOCK_ASSERT(ref); 822 unp_drop(ref); 823 UNP_REF_LIST_LOCK(); 824 } 825 826 UNP_REF_LIST_UNLOCK(); 827 UNP_PCB_LOCK(unp); 828 freeunp = unp_pcb_rele(unp); 829 MPASS(freeunp == 0); 830 local_unp_rights = unp_rights; 831 teardown: 832 unp->unp_socket->so_pcb = NULL; 833 saved_unp_addr = unp->unp_addr; 834 unp->unp_addr = NULL; 835 unp->unp_socket = NULL; 836 freeunp = unp_pcb_rele(unp); 837 if (saved_unp_addr != NULL) 838 free(saved_unp_addr, M_SONAME); 839 if (!freeunp) 840 UNP_PCB_UNLOCK(unp); 841 if (vp) { 842 mtx_unlock(vplock); 843 vrele(vp); 844 } 845 if (local_unp_rights) 846 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 847 } 848 849 static int 850 uipc_disconnect(struct socket *so) 851 { 852 struct unpcb *unp, *unp2; 853 int freed; 854 855 unp = sotounpcb(so); 856 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 857 858 UNP_PCB_LOCK(unp); 859 if ((unp2 = unp->unp_conn) == NULL) { 860 UNP_PCB_UNLOCK(unp); 861 return (0); 862 } 863 unp_pcb_owned_lock2(unp, unp2, freed); 864 if (__predict_false(freed)) { 865 UNP_PCB_UNLOCK(unp); 866 return (0); 867 } 868 unp_pcb_hold(unp2); 869 unp_pcb_hold(unp); 870 unp_disconnect(unp, unp2); 871 if (unp_pcb_rele(unp) == 0) 872 UNP_PCB_UNLOCK(unp); 873 if (unp_pcb_rele(unp2) == 0) 874 UNP_PCB_UNLOCK(unp2); 875 return (0); 876 } 877 878 static int 879 uipc_listen(struct socket *so, int backlog, struct thread *td) 880 { 881 struct unpcb *unp; 882 int error; 883 884 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 885 return (EOPNOTSUPP); 886 887 unp = sotounpcb(so); 888 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 889 890 UNP_PCB_LOCK(unp); 891 if (unp->unp_vnode == NULL) { 892 /* Already connected or not bound to an address. */ 893 error = unp->unp_conn != NULL ? EINVAL : EDESTADDRREQ; 894 UNP_PCB_UNLOCK(unp); 895 return (error); 896 } 897 898 SOCK_LOCK(so); 899 error = solisten_proto_check(so); 900 if (error == 0) { 901 cru2x(td->td_ucred, &unp->unp_peercred); 902 solisten_proto(so, backlog); 903 } 904 SOCK_UNLOCK(so); 905 UNP_PCB_UNLOCK(unp); 906 return (error); 907 } 908 909 static int 910 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 911 { 912 struct unpcb *unp, *unp2; 913 const struct sockaddr *sa; 914 915 unp = sotounpcb(so); 916 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 917 918 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 919 UNP_LINK_RLOCK(); 920 /* 921 * XXX: It seems that this test always fails even when connection is 922 * established. So, this else clause is added as workaround to 923 * return PF_LOCAL sockaddr. 924 */ 925 unp2 = unp->unp_conn; 926 if (unp2 != NULL) { 927 UNP_PCB_LOCK(unp2); 928 if (unp2->unp_addr != NULL) 929 sa = (struct sockaddr *) unp2->unp_addr; 930 else 931 sa = &sun_noname; 932 bcopy(sa, *nam, sa->sa_len); 933 UNP_PCB_UNLOCK(unp2); 934 } else { 935 sa = &sun_noname; 936 bcopy(sa, *nam, sa->sa_len); 937 } 938 UNP_LINK_RUNLOCK(); 939 return (0); 940 } 941 942 static int 943 uipc_rcvd(struct socket *so, int flags) 944 { 945 struct unpcb *unp, *unp2; 946 struct socket *so2; 947 u_int mbcnt, sbcc; 948 949 unp = sotounpcb(so); 950 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 951 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 952 ("%s: socktype %d", __func__, so->so_type)); 953 954 /* 955 * Adjust backpressure on sender and wakeup any waiting to write. 956 * 957 * The unp lock is acquired to maintain the validity of the unp_conn 958 * pointer; no lock on unp2 is required as unp2->unp_socket will be 959 * static as long as we don't permit unp2 to disconnect from unp, 960 * which is prevented by the lock on unp. We cache values from 961 * so_rcv to avoid holding the so_rcv lock over the entire 962 * transaction on the remote so_snd. 963 */ 964 SOCKBUF_LOCK(&so->so_rcv); 965 mbcnt = so->so_rcv.sb_mbcnt; 966 sbcc = sbavail(&so->so_rcv); 967 SOCKBUF_UNLOCK(&so->so_rcv); 968 /* 969 * There is a benign race condition at this point. If we're planning to 970 * clear SB_STOP, but uipc_send is called on the connected socket at 971 * this instant, it might add data to the sockbuf and set SB_STOP. Then 972 * we would erroneously clear SB_STOP below, even though the sockbuf is 973 * full. The race is benign because the only ill effect is to allow the 974 * sockbuf to exceed its size limit, and the size limits are not 975 * strictly guaranteed anyway. 976 */ 977 UNP_PCB_LOCK(unp); 978 unp2 = unp->unp_conn; 979 if (unp2 == NULL) { 980 UNP_PCB_UNLOCK(unp); 981 return (0); 982 } 983 so2 = unp2->unp_socket; 984 SOCKBUF_LOCK(&so2->so_snd); 985 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 986 so2->so_snd.sb_flags &= ~SB_STOP; 987 sowwakeup_locked(so2); 988 UNP_PCB_UNLOCK(unp); 989 return (0); 990 } 991 992 static int 993 connect_internal(struct socket *so, struct sockaddr *nam, struct thread *td) 994 { 995 int error; 996 struct unpcb *unp; 997 998 unp = so->so_pcb; 999 if (unp->unp_conn != NULL) 1000 return (EISCONN); 1001 error = unp_connect(so, nam, td); 1002 if (error) 1003 return (error); 1004 UNP_PCB_LOCK(unp); 1005 if (unp->unp_conn == NULL) { 1006 UNP_PCB_UNLOCK(unp); 1007 if (error == 0) 1008 error = ENOTCONN; 1009 } 1010 return (error); 1011 } 1012 1013 1014 static int 1015 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 1016 struct mbuf *control, struct thread *td) 1017 { 1018 struct unpcb *unp, *unp2; 1019 struct socket *so2; 1020 u_int mbcnt, sbcc; 1021 int freed, error; 1022 1023 unp = sotounpcb(so); 1024 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 1025 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 1026 so->so_type == SOCK_SEQPACKET, 1027 ("%s: socktype %d", __func__, so->so_type)); 1028 1029 freed = error = 0; 1030 if (flags & PRUS_OOB) { 1031 error = EOPNOTSUPP; 1032 goto release; 1033 } 1034 if (control != NULL && (error = unp_internalize(&control, td))) 1035 goto release; 1036 1037 unp2 = NULL; 1038 switch (so->so_type) { 1039 case SOCK_DGRAM: 1040 { 1041 const struct sockaddr *from; 1042 1043 if (nam != NULL) { 1044 /* 1045 * We return with UNP_PCB_LOCK_HELD so we know that 1046 * the reference is live if the pointer is valid. 1047 */ 1048 if ((error = connect_internal(so, nam, td))) 1049 break; 1050 MPASS(unp->unp_conn != NULL); 1051 unp2 = unp->unp_conn; 1052 } else { 1053 UNP_PCB_LOCK(unp); 1054 1055 /* 1056 * Because connect() and send() are non-atomic in a sendto() 1057 * with a target address, it's possible that the socket will 1058 * have disconnected before the send() can run. In that case 1059 * return the slightly counter-intuitive but otherwise 1060 * correct error that the socket is not connected. 1061 */ 1062 if ((unp2 = unp->unp_conn) == NULL) { 1063 UNP_PCB_UNLOCK(unp); 1064 error = ENOTCONN; 1065 break; 1066 } 1067 } 1068 unp_pcb_owned_lock2(unp, unp2, freed); 1069 if (__predict_false(freed)) { 1070 UNP_PCB_UNLOCK(unp); 1071 error = ENOTCONN; 1072 break; 1073 } 1074 /* 1075 * The socket referencing unp2 may have been closed 1076 * or unp may have been disconnected if the unp lock 1077 * was dropped to acquire unp2. 1078 */ 1079 if (__predict_false(unp->unp_conn == NULL) || 1080 unp2->unp_socket == NULL) { 1081 UNP_PCB_UNLOCK(unp); 1082 if (unp_pcb_rele(unp2) == 0) 1083 UNP_PCB_UNLOCK(unp2); 1084 error = ENOTCONN; 1085 break; 1086 } 1087 if (unp2->unp_flags & UNP_WANTCRED) 1088 control = unp_addsockcred(td, control); 1089 if (unp->unp_addr != NULL) 1090 from = (struct sockaddr *)unp->unp_addr; 1091 else 1092 from = &sun_noname; 1093 so2 = unp2->unp_socket; 1094 SOCKBUF_LOCK(&so2->so_rcv); 1095 if (sbappendaddr_locked(&so2->so_rcv, from, m, 1096 control)) { 1097 sorwakeup_locked(so2); 1098 m = NULL; 1099 control = NULL; 1100 } else { 1101 SOCKBUF_UNLOCK(&so2->so_rcv); 1102 error = ENOBUFS; 1103 } 1104 if (nam != NULL) 1105 unp_disconnect(unp, unp2); 1106 UNP_PCB_UNLOCK(unp2); 1107 UNP_PCB_UNLOCK(unp); 1108 break; 1109 } 1110 1111 case SOCK_SEQPACKET: 1112 case SOCK_STREAM: 1113 if ((so->so_state & SS_ISCONNECTED) == 0) { 1114 if (nam != NULL) { 1115 if ((error = connect_internal(so, nam, td))) 1116 break; 1117 } else { 1118 error = ENOTCONN; 1119 break; 1120 } 1121 } else if ((unp2 = unp->unp_conn) == NULL) { 1122 error = ENOTCONN; 1123 break; 1124 } else if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 1125 error = EPIPE; 1126 break; 1127 } else { 1128 UNP_PCB_LOCK(unp); 1129 if ((unp2 = unp->unp_conn) == NULL) { 1130 UNP_PCB_UNLOCK(unp); 1131 error = ENOTCONN; 1132 break; 1133 } 1134 } 1135 unp_pcb_owned_lock2(unp, unp2, freed); 1136 UNP_PCB_UNLOCK(unp); 1137 if (__predict_false(freed)) { 1138 error = ENOTCONN; 1139 break; 1140 } 1141 if ((so2 = unp2->unp_socket) == NULL) { 1142 UNP_PCB_UNLOCK(unp2); 1143 error = ENOTCONN; 1144 break; 1145 } 1146 SOCKBUF_LOCK(&so2->so_rcv); 1147 if (unp2->unp_flags & UNP_WANTCRED) { 1148 /* 1149 * Credentials are passed only once on SOCK_STREAM 1150 * and SOCK_SEQPACKET. 1151 */ 1152 unp2->unp_flags &= ~UNP_WANTCRED; 1153 control = unp_addsockcred(td, control); 1154 } 1155 /* 1156 * Send to paired receive port, and then reduce send buffer 1157 * hiwater marks to maintain backpressure. Wake up readers. 1158 */ 1159 switch (so->so_type) { 1160 case SOCK_STREAM: 1161 if (control != NULL) { 1162 if (sbappendcontrol_locked(&so2->so_rcv, m, 1163 control)) 1164 control = NULL; 1165 } else 1166 sbappend_locked(&so2->so_rcv, m, flags); 1167 break; 1168 1169 case SOCK_SEQPACKET: { 1170 const struct sockaddr *from; 1171 1172 from = &sun_noname; 1173 /* 1174 * Don't check for space available in so2->so_rcv. 1175 * Unix domain sockets only check for space in the 1176 * sending sockbuf, and that check is performed one 1177 * level up the stack. 1178 */ 1179 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 1180 from, m, control)) 1181 control = NULL; 1182 break; 1183 } 1184 } 1185 1186 mbcnt = so2->so_rcv.sb_mbcnt; 1187 sbcc = sbavail(&so2->so_rcv); 1188 if (sbcc) 1189 sorwakeup_locked(so2); 1190 else 1191 SOCKBUF_UNLOCK(&so2->so_rcv); 1192 1193 /* 1194 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1195 * it would be possible for uipc_rcvd to be called at this 1196 * point, drain the receiving sockbuf, clear SB_STOP, and then 1197 * we would set SB_STOP below. That could lead to an empty 1198 * sockbuf having SB_STOP set 1199 */ 1200 SOCKBUF_LOCK(&so->so_snd); 1201 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1202 so->so_snd.sb_flags |= SB_STOP; 1203 SOCKBUF_UNLOCK(&so->so_snd); 1204 UNP_PCB_UNLOCK(unp2); 1205 m = NULL; 1206 break; 1207 } 1208 1209 /* 1210 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1211 */ 1212 if (flags & PRUS_EOF) { 1213 UNP_PCB_LOCK(unp); 1214 socantsendmore(so); 1215 unp_shutdown(unp); 1216 UNP_PCB_UNLOCK(unp); 1217 } 1218 if (control != NULL && error != 0) 1219 unp_dispose_mbuf(control); 1220 1221 release: 1222 if (control != NULL) 1223 m_freem(control); 1224 /* 1225 * In case of PRUS_NOTREADY, uipc_ready() is responsible 1226 * for freeing memory. 1227 */ 1228 if (m != NULL && (flags & PRUS_NOTREADY) == 0) 1229 m_freem(m); 1230 return (error); 1231 } 1232 1233 static int 1234 uipc_ready(struct socket *so, struct mbuf *m, int count) 1235 { 1236 struct unpcb *unp, *unp2; 1237 struct socket *so2; 1238 int error; 1239 1240 unp = sotounpcb(so); 1241 1242 UNP_LINK_RLOCK(); 1243 if ((unp2 = unp->unp_conn) == NULL) { 1244 UNP_LINK_RUNLOCK(); 1245 for (int i = 0; i < count; i++) 1246 m = m_free(m); 1247 return (ECONNRESET); 1248 } 1249 UNP_PCB_LOCK(unp2); 1250 so2 = unp2->unp_socket; 1251 1252 SOCKBUF_LOCK(&so2->so_rcv); 1253 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1254 sorwakeup_locked(so2); 1255 else 1256 SOCKBUF_UNLOCK(&so2->so_rcv); 1257 1258 UNP_PCB_UNLOCK(unp2); 1259 UNP_LINK_RUNLOCK(); 1260 1261 return (error); 1262 } 1263 1264 static int 1265 uipc_sense(struct socket *so, struct stat *sb) 1266 { 1267 struct unpcb *unp; 1268 1269 unp = sotounpcb(so); 1270 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1271 1272 sb->st_blksize = so->so_snd.sb_hiwat; 1273 UNP_PCB_LOCK(unp); 1274 sb->st_dev = NODEV; 1275 if (unp->unp_ino == 0) 1276 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 1277 sb->st_ino = unp->unp_ino; 1278 UNP_PCB_UNLOCK(unp); 1279 return (0); 1280 } 1281 1282 static int 1283 uipc_shutdown(struct socket *so) 1284 { 1285 struct unpcb *unp; 1286 1287 unp = sotounpcb(so); 1288 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1289 1290 UNP_PCB_LOCK(unp); 1291 socantsendmore(so); 1292 unp_shutdown(unp); 1293 UNP_PCB_UNLOCK(unp); 1294 return (0); 1295 } 1296 1297 static int 1298 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1299 { 1300 struct unpcb *unp; 1301 const struct sockaddr *sa; 1302 1303 unp = sotounpcb(so); 1304 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1305 1306 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1307 UNP_PCB_LOCK(unp); 1308 if (unp->unp_addr != NULL) 1309 sa = (struct sockaddr *) unp->unp_addr; 1310 else 1311 sa = &sun_noname; 1312 bcopy(sa, *nam, sa->sa_len); 1313 UNP_PCB_UNLOCK(unp); 1314 return (0); 1315 } 1316 1317 static struct pr_usrreqs uipc_usrreqs_dgram = { 1318 .pru_abort = uipc_abort, 1319 .pru_accept = uipc_accept, 1320 .pru_attach = uipc_attach, 1321 .pru_bind = uipc_bind, 1322 .pru_bindat = uipc_bindat, 1323 .pru_connect = uipc_connect, 1324 .pru_connectat = uipc_connectat, 1325 .pru_connect2 = uipc_connect2, 1326 .pru_detach = uipc_detach, 1327 .pru_disconnect = uipc_disconnect, 1328 .pru_listen = uipc_listen, 1329 .pru_peeraddr = uipc_peeraddr, 1330 .pru_rcvd = uipc_rcvd, 1331 .pru_send = uipc_send, 1332 .pru_sense = uipc_sense, 1333 .pru_shutdown = uipc_shutdown, 1334 .pru_sockaddr = uipc_sockaddr, 1335 .pru_soreceive = soreceive_dgram, 1336 .pru_close = uipc_close, 1337 }; 1338 1339 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1340 .pru_abort = uipc_abort, 1341 .pru_accept = uipc_accept, 1342 .pru_attach = uipc_attach, 1343 .pru_bind = uipc_bind, 1344 .pru_bindat = uipc_bindat, 1345 .pru_connect = uipc_connect, 1346 .pru_connectat = uipc_connectat, 1347 .pru_connect2 = uipc_connect2, 1348 .pru_detach = uipc_detach, 1349 .pru_disconnect = uipc_disconnect, 1350 .pru_listen = uipc_listen, 1351 .pru_peeraddr = uipc_peeraddr, 1352 .pru_rcvd = uipc_rcvd, 1353 .pru_send = uipc_send, 1354 .pru_sense = uipc_sense, 1355 .pru_shutdown = uipc_shutdown, 1356 .pru_sockaddr = uipc_sockaddr, 1357 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1358 .pru_close = uipc_close, 1359 }; 1360 1361 static struct pr_usrreqs uipc_usrreqs_stream = { 1362 .pru_abort = uipc_abort, 1363 .pru_accept = uipc_accept, 1364 .pru_attach = uipc_attach, 1365 .pru_bind = uipc_bind, 1366 .pru_bindat = uipc_bindat, 1367 .pru_connect = uipc_connect, 1368 .pru_connectat = uipc_connectat, 1369 .pru_connect2 = uipc_connect2, 1370 .pru_detach = uipc_detach, 1371 .pru_disconnect = uipc_disconnect, 1372 .pru_listen = uipc_listen, 1373 .pru_peeraddr = uipc_peeraddr, 1374 .pru_rcvd = uipc_rcvd, 1375 .pru_send = uipc_send, 1376 .pru_ready = uipc_ready, 1377 .pru_sense = uipc_sense, 1378 .pru_shutdown = uipc_shutdown, 1379 .pru_sockaddr = uipc_sockaddr, 1380 .pru_soreceive = soreceive_generic, 1381 .pru_close = uipc_close, 1382 }; 1383 1384 static int 1385 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1386 { 1387 struct unpcb *unp; 1388 struct xucred xu; 1389 int error, optval; 1390 1391 if (sopt->sopt_level != 0) 1392 return (EINVAL); 1393 1394 unp = sotounpcb(so); 1395 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1396 error = 0; 1397 switch (sopt->sopt_dir) { 1398 case SOPT_GET: 1399 switch (sopt->sopt_name) { 1400 case LOCAL_PEERCRED: 1401 UNP_PCB_LOCK(unp); 1402 if (unp->unp_flags & UNP_HAVEPC) 1403 xu = unp->unp_peercred; 1404 else { 1405 if (so->so_type == SOCK_STREAM) 1406 error = ENOTCONN; 1407 else 1408 error = EINVAL; 1409 } 1410 UNP_PCB_UNLOCK(unp); 1411 if (error == 0) 1412 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1413 break; 1414 1415 case LOCAL_CREDS: 1416 /* Unlocked read. */ 1417 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1418 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1419 break; 1420 1421 case LOCAL_CONNWAIT: 1422 /* Unlocked read. */ 1423 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1424 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1425 break; 1426 1427 default: 1428 error = EOPNOTSUPP; 1429 break; 1430 } 1431 break; 1432 1433 case SOPT_SET: 1434 switch (sopt->sopt_name) { 1435 case LOCAL_CREDS: 1436 case LOCAL_CONNWAIT: 1437 error = sooptcopyin(sopt, &optval, sizeof(optval), 1438 sizeof(optval)); 1439 if (error) 1440 break; 1441 1442 #define OPTSET(bit) do { \ 1443 UNP_PCB_LOCK(unp); \ 1444 if (optval) \ 1445 unp->unp_flags |= bit; \ 1446 else \ 1447 unp->unp_flags &= ~bit; \ 1448 UNP_PCB_UNLOCK(unp); \ 1449 } while (0) 1450 1451 switch (sopt->sopt_name) { 1452 case LOCAL_CREDS: 1453 OPTSET(UNP_WANTCRED); 1454 break; 1455 1456 case LOCAL_CONNWAIT: 1457 OPTSET(UNP_CONNWAIT); 1458 break; 1459 1460 default: 1461 break; 1462 } 1463 break; 1464 #undef OPTSET 1465 default: 1466 error = ENOPROTOOPT; 1467 break; 1468 } 1469 break; 1470 1471 default: 1472 error = EOPNOTSUPP; 1473 break; 1474 } 1475 return (error); 1476 } 1477 1478 static int 1479 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1480 { 1481 1482 return (unp_connectat(AT_FDCWD, so, nam, td)); 1483 } 1484 1485 static int 1486 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1487 struct thread *td) 1488 { 1489 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1490 struct vnode *vp; 1491 struct socket *so2; 1492 struct unpcb *unp, *unp2, *unp3; 1493 struct nameidata nd; 1494 char buf[SOCK_MAXADDRLEN]; 1495 struct sockaddr *sa; 1496 cap_rights_t rights; 1497 int error, len, freed; 1498 struct mtx *vplock; 1499 1500 if (nam->sa_family != AF_UNIX) 1501 return (EAFNOSUPPORT); 1502 if (nam->sa_len > sizeof(struct sockaddr_un)) 1503 return (EINVAL); 1504 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1505 if (len <= 0) 1506 return (EINVAL); 1507 bcopy(soun->sun_path, buf, len); 1508 buf[len] = 0; 1509 1510 unp = sotounpcb(so); 1511 UNP_PCB_LOCK(unp); 1512 if (unp->unp_flags & UNP_CONNECTING) { 1513 UNP_PCB_UNLOCK(unp); 1514 return (EALREADY); 1515 } 1516 unp->unp_flags |= UNP_CONNECTING; 1517 UNP_PCB_UNLOCK(unp); 1518 1519 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1520 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1521 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td); 1522 error = namei(&nd); 1523 if (error) 1524 vp = NULL; 1525 else 1526 vp = nd.ni_vp; 1527 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1528 NDFREE(&nd, NDF_ONLY_PNBUF); 1529 if (error) 1530 goto bad; 1531 1532 if (vp->v_type != VSOCK) { 1533 error = ENOTSOCK; 1534 goto bad; 1535 } 1536 #ifdef MAC 1537 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1538 if (error) 1539 goto bad; 1540 #endif 1541 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1542 if (error) 1543 goto bad; 1544 1545 unp = sotounpcb(so); 1546 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1547 1548 vplock = mtx_pool_find(mtxpool_sleep, vp); 1549 mtx_lock(vplock); 1550 VOP_UNP_CONNECT(vp, &unp2); 1551 if (unp2 == NULL) { 1552 error = ECONNREFUSED; 1553 goto bad2; 1554 } 1555 so2 = unp2->unp_socket; 1556 if (so->so_type != so2->so_type) { 1557 error = EPROTOTYPE; 1558 goto bad2; 1559 } 1560 unp_pcb_lock2(unp, unp2); 1561 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1562 if (so2->so_options & SO_ACCEPTCONN) { 1563 CURVNET_SET(so2->so_vnet); 1564 so2 = sonewconn(so2, 0); 1565 CURVNET_RESTORE(); 1566 } else 1567 so2 = NULL; 1568 if (so2 == NULL) { 1569 error = ECONNREFUSED; 1570 goto bad3; 1571 } 1572 unp3 = sotounpcb(so2); 1573 UNP_PCB_UNLOCK(unp); 1574 unp_pcb_owned_lock2(unp2, unp3, freed); 1575 MPASS(!freed); 1576 if (unp2->unp_addr != NULL) { 1577 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1578 unp3->unp_addr = (struct sockaddr_un *) sa; 1579 sa = NULL; 1580 } 1581 1582 /* 1583 * The connector's (client's) credentials are copied from its 1584 * process structure at the time of connect() (which is now). 1585 */ 1586 cru2x(td->td_ucred, &unp3->unp_peercred); 1587 unp3->unp_flags |= UNP_HAVEPC; 1588 1589 /* 1590 * The receiver's (server's) credentials are copied from the 1591 * unp_peercred member of socket on which the former called 1592 * listen(); uipc_listen() cached that process's credentials 1593 * at that time so we can use them now. 1594 */ 1595 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1596 sizeof(unp->unp_peercred)); 1597 unp->unp_flags |= UNP_HAVEPC; 1598 if (unp2->unp_flags & UNP_WANTCRED) 1599 unp3->unp_flags |= UNP_WANTCRED; 1600 UNP_PCB_UNLOCK(unp2); 1601 unp2 = unp3; 1602 unp_pcb_owned_lock2(unp2, unp, freed); 1603 MPASS(!freed); 1604 #ifdef MAC 1605 mac_socketpeer_set_from_socket(so, so2); 1606 mac_socketpeer_set_from_socket(so2, so); 1607 #endif 1608 } 1609 1610 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1611 sotounpcb(so2) == unp2, 1612 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1613 error = unp_connect2(so, so2, PRU_CONNECT); 1614 bad3: 1615 UNP_PCB_UNLOCK(unp2); 1616 UNP_PCB_UNLOCK(unp); 1617 bad2: 1618 mtx_unlock(vplock); 1619 bad: 1620 if (vp != NULL) { 1621 vput(vp); 1622 } 1623 free(sa, M_SONAME); 1624 UNP_PCB_LOCK(unp); 1625 unp->unp_flags &= ~UNP_CONNECTING; 1626 UNP_PCB_UNLOCK(unp); 1627 return (error); 1628 } 1629 1630 static int 1631 unp_connect2(struct socket *so, struct socket *so2, int req) 1632 { 1633 struct unpcb *unp; 1634 struct unpcb *unp2; 1635 1636 unp = sotounpcb(so); 1637 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1638 unp2 = sotounpcb(so2); 1639 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1640 1641 UNP_PCB_LOCK_ASSERT(unp); 1642 UNP_PCB_LOCK_ASSERT(unp2); 1643 1644 if (so2->so_type != so->so_type) 1645 return (EPROTOTYPE); 1646 unp2->unp_flags &= ~UNP_NASCENT; 1647 unp->unp_conn = unp2; 1648 unp_pcb_hold(unp2); 1649 unp_pcb_hold(unp); 1650 switch (so->so_type) { 1651 case SOCK_DGRAM: 1652 UNP_REF_LIST_LOCK(); 1653 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1654 UNP_REF_LIST_UNLOCK(); 1655 soisconnected(so); 1656 break; 1657 1658 case SOCK_STREAM: 1659 case SOCK_SEQPACKET: 1660 unp2->unp_conn = unp; 1661 if (req == PRU_CONNECT && 1662 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1663 soisconnecting(so); 1664 else 1665 soisconnected(so); 1666 soisconnected(so2); 1667 break; 1668 1669 default: 1670 panic("unp_connect2"); 1671 } 1672 return (0); 1673 } 1674 1675 static void 1676 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1677 { 1678 struct socket *so, *so2; 1679 int rele, freed; 1680 1681 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1682 1683 UNP_PCB_LOCK_ASSERT(unp); 1684 UNP_PCB_LOCK_ASSERT(unp2); 1685 1686 if (unp->unp_conn == NULL && unp2->unp_conn == NULL) 1687 return; 1688 1689 MPASS(unp->unp_conn == unp2); 1690 unp->unp_conn = NULL; 1691 rele = 0; 1692 so = unp->unp_socket; 1693 so2 = unp2->unp_socket; 1694 switch (unp->unp_socket->so_type) { 1695 case SOCK_DGRAM: 1696 UNP_REF_LIST_LOCK(); 1697 LIST_REMOVE(unp, unp_reflink); 1698 UNP_REF_LIST_UNLOCK(); 1699 if (so) { 1700 SOCK_LOCK(so); 1701 so->so_state &= ~SS_ISCONNECTED; 1702 SOCK_UNLOCK(so); 1703 } 1704 break; 1705 1706 case SOCK_STREAM: 1707 case SOCK_SEQPACKET: 1708 if (so) 1709 soisdisconnected(so); 1710 MPASS(unp2->unp_conn == unp); 1711 unp2->unp_conn = NULL; 1712 if (so2) 1713 soisdisconnected(so2); 1714 break; 1715 } 1716 freed = unp_pcb_rele(unp); 1717 MPASS(freed == 0); 1718 freed = unp_pcb_rele(unp2); 1719 MPASS(freed == 0); 1720 } 1721 1722 /* 1723 * unp_pcblist() walks the global list of struct unpcb's to generate a 1724 * pointer list, bumping the refcount on each unpcb. It then copies them out 1725 * sequentially, validating the generation number on each to see if it has 1726 * been detached. All of this is necessary because copyout() may sleep on 1727 * disk I/O. 1728 */ 1729 static int 1730 unp_pcblist(SYSCTL_HANDLER_ARGS) 1731 { 1732 struct unpcb *unp, **unp_list; 1733 unp_gen_t gencnt; 1734 struct xunpgen *xug; 1735 struct unp_head *head; 1736 struct xunpcb *xu; 1737 u_int i; 1738 int error, freeunp, n; 1739 1740 switch ((intptr_t)arg1) { 1741 case SOCK_STREAM: 1742 head = &unp_shead; 1743 break; 1744 1745 case SOCK_DGRAM: 1746 head = &unp_dhead; 1747 break; 1748 1749 case SOCK_SEQPACKET: 1750 head = &unp_sphead; 1751 break; 1752 1753 default: 1754 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1755 } 1756 1757 /* 1758 * The process of preparing the PCB list is too time-consuming and 1759 * resource-intensive to repeat twice on every request. 1760 */ 1761 if (req->oldptr == NULL) { 1762 n = unp_count; 1763 req->oldidx = 2 * (sizeof *xug) 1764 + (n + n/8) * sizeof(struct xunpcb); 1765 return (0); 1766 } 1767 1768 if (req->newptr != NULL) 1769 return (EPERM); 1770 1771 /* 1772 * OK, now we're committed to doing something. 1773 */ 1774 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1775 UNP_LINK_RLOCK(); 1776 gencnt = unp_gencnt; 1777 n = unp_count; 1778 UNP_LINK_RUNLOCK(); 1779 1780 xug->xug_len = sizeof *xug; 1781 xug->xug_count = n; 1782 xug->xug_gen = gencnt; 1783 xug->xug_sogen = so_gencnt; 1784 error = SYSCTL_OUT(req, xug, sizeof *xug); 1785 if (error) { 1786 free(xug, M_TEMP); 1787 return (error); 1788 } 1789 1790 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1791 1792 UNP_LINK_RLOCK(); 1793 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1794 unp = LIST_NEXT(unp, unp_link)) { 1795 UNP_PCB_LOCK(unp); 1796 if (unp->unp_gencnt <= gencnt) { 1797 if (cr_cansee(req->td->td_ucred, 1798 unp->unp_socket->so_cred)) { 1799 UNP_PCB_UNLOCK(unp); 1800 continue; 1801 } 1802 unp_list[i++] = unp; 1803 unp_pcb_hold(unp); 1804 } 1805 UNP_PCB_UNLOCK(unp); 1806 } 1807 UNP_LINK_RUNLOCK(); 1808 n = i; /* In case we lost some during malloc. */ 1809 1810 error = 0; 1811 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1812 for (i = 0; i < n; i++) { 1813 unp = unp_list[i]; 1814 UNP_PCB_LOCK(unp); 1815 freeunp = unp_pcb_rele(unp); 1816 1817 if (freeunp == 0 && unp->unp_gencnt <= gencnt) { 1818 xu->xu_len = sizeof *xu; 1819 xu->xu_unpp = unp; 1820 /* 1821 * XXX - need more locking here to protect against 1822 * connect/disconnect races for SMP. 1823 */ 1824 if (unp->unp_addr != NULL) 1825 bcopy(unp->unp_addr, &xu->xu_addr, 1826 unp->unp_addr->sun_len); 1827 else 1828 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1829 if (unp->unp_conn != NULL && 1830 unp->unp_conn->unp_addr != NULL) 1831 bcopy(unp->unp_conn->unp_addr, 1832 &xu->xu_caddr, 1833 unp->unp_conn->unp_addr->sun_len); 1834 else 1835 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1836 xu->unp_vnode = unp->unp_vnode; 1837 xu->unp_conn = unp->unp_conn; 1838 xu->xu_firstref = LIST_FIRST(&unp->unp_refs); 1839 xu->xu_nextref = LIST_NEXT(unp, unp_reflink); 1840 xu->unp_gencnt = unp->unp_gencnt; 1841 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1842 UNP_PCB_UNLOCK(unp); 1843 error = SYSCTL_OUT(req, xu, sizeof *xu); 1844 } else if (freeunp == 0) 1845 UNP_PCB_UNLOCK(unp); 1846 } 1847 free(xu, M_TEMP); 1848 if (!error) { 1849 /* 1850 * Give the user an updated idea of our state. If the 1851 * generation differs from what we told her before, she knows 1852 * that something happened while we were processing this 1853 * request, and it might be necessary to retry. 1854 */ 1855 xug->xug_gen = unp_gencnt; 1856 xug->xug_sogen = so_gencnt; 1857 xug->xug_count = unp_count; 1858 error = SYSCTL_OUT(req, xug, sizeof *xug); 1859 } 1860 free(unp_list, M_TEMP); 1861 free(xug, M_TEMP); 1862 return (error); 1863 } 1864 1865 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1866 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1867 "List of active local datagram sockets"); 1868 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1869 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1870 "List of active local stream sockets"); 1871 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1872 CTLTYPE_OPAQUE | CTLFLAG_RD, 1873 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1874 "List of active local seqpacket sockets"); 1875 1876 static void 1877 unp_shutdown(struct unpcb *unp) 1878 { 1879 struct unpcb *unp2; 1880 struct socket *so; 1881 1882 UNP_PCB_LOCK_ASSERT(unp); 1883 1884 unp2 = unp->unp_conn; 1885 if ((unp->unp_socket->so_type == SOCK_STREAM || 1886 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1887 so = unp2->unp_socket; 1888 if (so != NULL) 1889 socantrcvmore(so); 1890 } 1891 } 1892 1893 static void 1894 unp_drop(struct unpcb *unp) 1895 { 1896 struct socket *so = unp->unp_socket; 1897 struct unpcb *unp2; 1898 int freed; 1899 1900 /* 1901 * Regardless of whether the socket's peer dropped the connection 1902 * with this socket by aborting or disconnecting, POSIX requires 1903 * that ECONNRESET is returned. 1904 */ 1905 /* acquire a reference so that unp isn't freed from underneath us */ 1906 1907 UNP_PCB_LOCK(unp); 1908 if (so) 1909 so->so_error = ECONNRESET; 1910 unp2 = unp->unp_conn; 1911 if (unp2 != NULL) { 1912 unp_pcb_hold(unp2); 1913 unp_pcb_owned_lock2(unp, unp2, freed); 1914 unp_disconnect(unp, unp2); 1915 if (unp_pcb_rele(unp2) == 0) 1916 UNP_PCB_UNLOCK(unp2); 1917 } 1918 if (unp_pcb_rele(unp) == 0) 1919 UNP_PCB_UNLOCK(unp); 1920 } 1921 1922 static void 1923 unp_freerights(struct filedescent **fdep, int fdcount) 1924 { 1925 struct file *fp; 1926 int i; 1927 1928 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1929 1930 for (i = 0; i < fdcount; i++) { 1931 fp = fdep[i]->fde_file; 1932 filecaps_free(&fdep[i]->fde_caps); 1933 unp_discard(fp); 1934 } 1935 free(fdep[0], M_FILECAPS); 1936 } 1937 1938 static int 1939 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 1940 { 1941 struct thread *td = curthread; /* XXX */ 1942 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1943 int i; 1944 int *fdp; 1945 struct filedesc *fdesc = td->td_proc->p_fd; 1946 struct filedescent **fdep; 1947 void *data; 1948 socklen_t clen = control->m_len, datalen; 1949 int error, newfds; 1950 u_int newlen; 1951 1952 UNP_LINK_UNLOCK_ASSERT(); 1953 1954 error = 0; 1955 if (controlp != NULL) /* controlp == NULL => free control messages */ 1956 *controlp = NULL; 1957 while (cm != NULL) { 1958 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1959 error = EINVAL; 1960 break; 1961 } 1962 data = CMSG_DATA(cm); 1963 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1964 if (cm->cmsg_level == SOL_SOCKET 1965 && cm->cmsg_type == SCM_RIGHTS) { 1966 newfds = datalen / sizeof(*fdep); 1967 if (newfds == 0) 1968 goto next; 1969 fdep = data; 1970 1971 /* If we're not outputting the descriptors free them. */ 1972 if (error || controlp == NULL) { 1973 unp_freerights(fdep, newfds); 1974 goto next; 1975 } 1976 FILEDESC_XLOCK(fdesc); 1977 1978 /* 1979 * Now change each pointer to an fd in the global 1980 * table to an integer that is the index to the local 1981 * fd table entry that we set up to point to the 1982 * global one we are transferring. 1983 */ 1984 newlen = newfds * sizeof(int); 1985 *controlp = sbcreatecontrol(NULL, newlen, 1986 SCM_RIGHTS, SOL_SOCKET); 1987 if (*controlp == NULL) { 1988 FILEDESC_XUNLOCK(fdesc); 1989 error = E2BIG; 1990 unp_freerights(fdep, newfds); 1991 goto next; 1992 } 1993 1994 fdp = (int *) 1995 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1996 if (fdallocn(td, 0, fdp, newfds) != 0) { 1997 FILEDESC_XUNLOCK(fdesc); 1998 error = EMSGSIZE; 1999 unp_freerights(fdep, newfds); 2000 m_freem(*controlp); 2001 *controlp = NULL; 2002 goto next; 2003 } 2004 for (i = 0; i < newfds; i++, fdp++) { 2005 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2006 (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0, 2007 &fdep[i]->fde_caps); 2008 unp_externalize_fp(fdep[i]->fde_file); 2009 } 2010 FILEDESC_XUNLOCK(fdesc); 2011 free(fdep[0], M_FILECAPS); 2012 } else { 2013 /* We can just copy anything else across. */ 2014 if (error || controlp == NULL) 2015 goto next; 2016 *controlp = sbcreatecontrol(NULL, datalen, 2017 cm->cmsg_type, cm->cmsg_level); 2018 if (*controlp == NULL) { 2019 error = ENOBUFS; 2020 goto next; 2021 } 2022 bcopy(data, 2023 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2024 datalen); 2025 } 2026 controlp = &(*controlp)->m_next; 2027 2028 next: 2029 if (CMSG_SPACE(datalen) < clen) { 2030 clen -= CMSG_SPACE(datalen); 2031 cm = (struct cmsghdr *) 2032 ((caddr_t)cm + CMSG_SPACE(datalen)); 2033 } else { 2034 clen = 0; 2035 cm = NULL; 2036 } 2037 } 2038 2039 m_freem(control); 2040 return (error); 2041 } 2042 2043 static void 2044 unp_zone_change(void *tag) 2045 { 2046 2047 uma_zone_set_max(unp_zone, maxsockets); 2048 } 2049 2050 static void 2051 unp_init(void) 2052 { 2053 2054 #ifdef VIMAGE 2055 if (!IS_DEFAULT_VNET(curvnet)) 2056 return; 2057 #endif 2058 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 2059 NULL, NULL, UMA_ALIGN_CACHE, 0); 2060 if (unp_zone == NULL) 2061 panic("unp_init"); 2062 uma_zone_set_max(unp_zone, maxsockets); 2063 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2064 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2065 NULL, EVENTHANDLER_PRI_ANY); 2066 LIST_INIT(&unp_dhead); 2067 LIST_INIT(&unp_shead); 2068 LIST_INIT(&unp_sphead); 2069 SLIST_INIT(&unp_defers); 2070 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2071 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2072 UNP_LINK_LOCK_INIT(); 2073 UNP_DEFERRED_LOCK_INIT(); 2074 } 2075 2076 static int 2077 unp_internalize(struct mbuf **controlp, struct thread *td) 2078 { 2079 struct mbuf *control = *controlp; 2080 struct proc *p = td->td_proc; 2081 struct filedesc *fdesc = p->p_fd; 2082 struct bintime *bt; 2083 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2084 struct cmsgcred *cmcred; 2085 struct filedescent *fde, **fdep, *fdev; 2086 struct file *fp; 2087 struct timeval *tv; 2088 struct timespec *ts; 2089 int i, *fdp; 2090 void *data; 2091 socklen_t clen = control->m_len, datalen; 2092 int error, oldfds; 2093 u_int newlen; 2094 2095 UNP_LINK_UNLOCK_ASSERT(); 2096 2097 error = 0; 2098 *controlp = NULL; 2099 while (cm != NULL) { 2100 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2101 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2102 error = EINVAL; 2103 goto out; 2104 } 2105 data = CMSG_DATA(cm); 2106 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2107 2108 switch (cm->cmsg_type) { 2109 /* 2110 * Fill in credential information. 2111 */ 2112 case SCM_CREDS: 2113 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2114 SCM_CREDS, SOL_SOCKET); 2115 if (*controlp == NULL) { 2116 error = ENOBUFS; 2117 goto out; 2118 } 2119 cmcred = (struct cmsgcred *) 2120 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2121 cmcred->cmcred_pid = p->p_pid; 2122 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2123 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2124 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2125 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2126 CMGROUP_MAX); 2127 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2128 cmcred->cmcred_groups[i] = 2129 td->td_ucred->cr_groups[i]; 2130 break; 2131 2132 case SCM_RIGHTS: 2133 oldfds = datalen / sizeof (int); 2134 if (oldfds == 0) 2135 break; 2136 /* 2137 * Check that all the FDs passed in refer to legal 2138 * files. If not, reject the entire operation. 2139 */ 2140 fdp = data; 2141 FILEDESC_SLOCK(fdesc); 2142 for (i = 0; i < oldfds; i++, fdp++) { 2143 fp = fget_locked(fdesc, *fdp); 2144 if (fp == NULL) { 2145 FILEDESC_SUNLOCK(fdesc); 2146 error = EBADF; 2147 goto out; 2148 } 2149 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2150 FILEDESC_SUNLOCK(fdesc); 2151 error = EOPNOTSUPP; 2152 goto out; 2153 } 2154 2155 } 2156 2157 /* 2158 * Now replace the integer FDs with pointers to the 2159 * file structure and capability rights. 2160 */ 2161 newlen = oldfds * sizeof(fdep[0]); 2162 *controlp = sbcreatecontrol(NULL, newlen, 2163 SCM_RIGHTS, SOL_SOCKET); 2164 if (*controlp == NULL) { 2165 FILEDESC_SUNLOCK(fdesc); 2166 error = E2BIG; 2167 goto out; 2168 } 2169 fdp = data; 2170 fdep = (struct filedescent **) 2171 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2172 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2173 M_WAITOK); 2174 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2175 fde = &fdesc->fd_ofiles[*fdp]; 2176 fdep[i] = fdev; 2177 fdep[i]->fde_file = fde->fde_file; 2178 filecaps_copy(&fde->fde_caps, 2179 &fdep[i]->fde_caps, true); 2180 unp_internalize_fp(fdep[i]->fde_file); 2181 } 2182 FILEDESC_SUNLOCK(fdesc); 2183 break; 2184 2185 case SCM_TIMESTAMP: 2186 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2187 SCM_TIMESTAMP, SOL_SOCKET); 2188 if (*controlp == NULL) { 2189 error = ENOBUFS; 2190 goto out; 2191 } 2192 tv = (struct timeval *) 2193 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2194 microtime(tv); 2195 break; 2196 2197 case SCM_BINTIME: 2198 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2199 SCM_BINTIME, SOL_SOCKET); 2200 if (*controlp == NULL) { 2201 error = ENOBUFS; 2202 goto out; 2203 } 2204 bt = (struct bintime *) 2205 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2206 bintime(bt); 2207 break; 2208 2209 case SCM_REALTIME: 2210 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2211 SCM_REALTIME, SOL_SOCKET); 2212 if (*controlp == NULL) { 2213 error = ENOBUFS; 2214 goto out; 2215 } 2216 ts = (struct timespec *) 2217 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2218 nanotime(ts); 2219 break; 2220 2221 case SCM_MONOTONIC: 2222 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2223 SCM_MONOTONIC, SOL_SOCKET); 2224 if (*controlp == NULL) { 2225 error = ENOBUFS; 2226 goto out; 2227 } 2228 ts = (struct timespec *) 2229 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2230 nanouptime(ts); 2231 break; 2232 2233 default: 2234 error = EINVAL; 2235 goto out; 2236 } 2237 2238 controlp = &(*controlp)->m_next; 2239 if (CMSG_SPACE(datalen) < clen) { 2240 clen -= CMSG_SPACE(datalen); 2241 cm = (struct cmsghdr *) 2242 ((caddr_t)cm + CMSG_SPACE(datalen)); 2243 } else { 2244 clen = 0; 2245 cm = NULL; 2246 } 2247 } 2248 2249 out: 2250 m_freem(control); 2251 return (error); 2252 } 2253 2254 static struct mbuf * 2255 unp_addsockcred(struct thread *td, struct mbuf *control) 2256 { 2257 struct mbuf *m, *n, *n_prev; 2258 struct sockcred *sc; 2259 const struct cmsghdr *cm; 2260 int ngroups; 2261 int i; 2262 2263 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2264 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 2265 if (m == NULL) 2266 return (control); 2267 2268 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 2269 sc->sc_uid = td->td_ucred->cr_ruid; 2270 sc->sc_euid = td->td_ucred->cr_uid; 2271 sc->sc_gid = td->td_ucred->cr_rgid; 2272 sc->sc_egid = td->td_ucred->cr_gid; 2273 sc->sc_ngroups = ngroups; 2274 for (i = 0; i < sc->sc_ngroups; i++) 2275 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2276 2277 /* 2278 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2279 * created SCM_CREDS control message (struct sockcred) has another 2280 * format. 2281 */ 2282 if (control != NULL) 2283 for (n = control, n_prev = NULL; n != NULL;) { 2284 cm = mtod(n, struct cmsghdr *); 2285 if (cm->cmsg_level == SOL_SOCKET && 2286 cm->cmsg_type == SCM_CREDS) { 2287 if (n_prev == NULL) 2288 control = n->m_next; 2289 else 2290 n_prev->m_next = n->m_next; 2291 n = m_free(n); 2292 } else { 2293 n_prev = n; 2294 n = n->m_next; 2295 } 2296 } 2297 2298 /* Prepend it to the head. */ 2299 m->m_next = control; 2300 return (m); 2301 } 2302 2303 static struct unpcb * 2304 fptounp(struct file *fp) 2305 { 2306 struct socket *so; 2307 2308 if (fp->f_type != DTYPE_SOCKET) 2309 return (NULL); 2310 if ((so = fp->f_data) == NULL) 2311 return (NULL); 2312 if (so->so_proto->pr_domain != &localdomain) 2313 return (NULL); 2314 return sotounpcb(so); 2315 } 2316 2317 static void 2318 unp_discard(struct file *fp) 2319 { 2320 struct unp_defer *dr; 2321 2322 if (unp_externalize_fp(fp)) { 2323 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2324 dr->ud_fp = fp; 2325 UNP_DEFERRED_LOCK(); 2326 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2327 UNP_DEFERRED_UNLOCK(); 2328 atomic_add_int(&unp_defers_count, 1); 2329 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2330 } else 2331 (void) closef(fp, (struct thread *)NULL); 2332 } 2333 2334 static void 2335 unp_process_defers(void *arg __unused, int pending) 2336 { 2337 struct unp_defer *dr; 2338 SLIST_HEAD(, unp_defer) drl; 2339 int count; 2340 2341 SLIST_INIT(&drl); 2342 for (;;) { 2343 UNP_DEFERRED_LOCK(); 2344 if (SLIST_FIRST(&unp_defers) == NULL) { 2345 UNP_DEFERRED_UNLOCK(); 2346 break; 2347 } 2348 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2349 UNP_DEFERRED_UNLOCK(); 2350 count = 0; 2351 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2352 SLIST_REMOVE_HEAD(&drl, ud_link); 2353 closef(dr->ud_fp, NULL); 2354 free(dr, M_TEMP); 2355 count++; 2356 } 2357 atomic_add_int(&unp_defers_count, -count); 2358 } 2359 } 2360 2361 static void 2362 unp_internalize_fp(struct file *fp) 2363 { 2364 struct unpcb *unp; 2365 2366 UNP_LINK_WLOCK(); 2367 if ((unp = fptounp(fp)) != NULL) { 2368 unp->unp_file = fp; 2369 unp->unp_msgcount++; 2370 } 2371 fhold(fp); 2372 unp_rights++; 2373 UNP_LINK_WUNLOCK(); 2374 } 2375 2376 static int 2377 unp_externalize_fp(struct file *fp) 2378 { 2379 struct unpcb *unp; 2380 int ret; 2381 2382 UNP_LINK_WLOCK(); 2383 if ((unp = fptounp(fp)) != NULL) { 2384 unp->unp_msgcount--; 2385 ret = 1; 2386 } else 2387 ret = 0; 2388 unp_rights--; 2389 UNP_LINK_WUNLOCK(); 2390 return (ret); 2391 } 2392 2393 /* 2394 * unp_defer indicates whether additional work has been defered for a future 2395 * pass through unp_gc(). It is thread local and does not require explicit 2396 * synchronization. 2397 */ 2398 static int unp_marked; 2399 static int unp_unreachable; 2400 2401 static void 2402 unp_accessable(struct filedescent **fdep, int fdcount) 2403 { 2404 struct unpcb *unp; 2405 struct file *fp; 2406 int i; 2407 2408 for (i = 0; i < fdcount; i++) { 2409 fp = fdep[i]->fde_file; 2410 if ((unp = fptounp(fp)) == NULL) 2411 continue; 2412 if (unp->unp_gcflag & UNPGC_REF) 2413 continue; 2414 unp->unp_gcflag &= ~UNPGC_DEAD; 2415 unp->unp_gcflag |= UNPGC_REF; 2416 unp_marked++; 2417 } 2418 } 2419 2420 static void 2421 unp_gc_process(struct unpcb *unp) 2422 { 2423 struct socket *so, *soa; 2424 struct file *fp; 2425 2426 /* Already processed. */ 2427 if (unp->unp_gcflag & UNPGC_SCANNED) 2428 return; 2429 fp = unp->unp_file; 2430 2431 /* 2432 * Check for a socket potentially in a cycle. It must be in a 2433 * queue as indicated by msgcount, and this must equal the file 2434 * reference count. Note that when msgcount is 0 the file is NULL. 2435 */ 2436 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2437 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2438 unp->unp_gcflag |= UNPGC_DEAD; 2439 unp_unreachable++; 2440 return; 2441 } 2442 2443 so = unp->unp_socket; 2444 SOCK_LOCK(so); 2445 if (SOLISTENING(so)) { 2446 /* 2447 * Mark all sockets in our accept queue. 2448 */ 2449 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2450 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2451 continue; 2452 SOCKBUF_LOCK(&soa->so_rcv); 2453 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2454 SOCKBUF_UNLOCK(&soa->so_rcv); 2455 } 2456 } else { 2457 /* 2458 * Mark all sockets we reference with RIGHTS. 2459 */ 2460 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2461 SOCKBUF_LOCK(&so->so_rcv); 2462 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2463 SOCKBUF_UNLOCK(&so->so_rcv); 2464 } 2465 } 2466 SOCK_UNLOCK(so); 2467 unp->unp_gcflag |= UNPGC_SCANNED; 2468 } 2469 2470 static int unp_recycled; 2471 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2472 "Number of unreachable sockets claimed by the garbage collector."); 2473 2474 static int unp_taskcount; 2475 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2476 "Number of times the garbage collector has run."); 2477 2478 static void 2479 unp_gc(__unused void *arg, int pending) 2480 { 2481 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2482 NULL }; 2483 struct unp_head **head; 2484 struct file *f, **unref; 2485 struct unpcb *unp; 2486 int i, total; 2487 2488 unp_taskcount++; 2489 UNP_LINK_RLOCK(); 2490 /* 2491 * First clear all gc flags from previous runs, apart from 2492 * UNPGC_IGNORE_RIGHTS. 2493 */ 2494 for (head = heads; *head != NULL; head++) 2495 LIST_FOREACH(unp, *head, unp_link) 2496 unp->unp_gcflag = 2497 (unp->unp_gcflag & UNPGC_IGNORE_RIGHTS); 2498 2499 /* 2500 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2501 * is reachable all of the sockets it references are reachable. 2502 * Stop the scan once we do a complete loop without discovering 2503 * a new reachable socket. 2504 */ 2505 do { 2506 unp_unreachable = 0; 2507 unp_marked = 0; 2508 for (head = heads; *head != NULL; head++) 2509 LIST_FOREACH(unp, *head, unp_link) 2510 unp_gc_process(unp); 2511 } while (unp_marked); 2512 UNP_LINK_RUNLOCK(); 2513 if (unp_unreachable == 0) 2514 return; 2515 2516 /* 2517 * Allocate space for a local list of dead unpcbs. 2518 */ 2519 unref = malloc(unp_unreachable * sizeof(struct file *), 2520 M_TEMP, M_WAITOK); 2521 2522 /* 2523 * Iterate looking for sockets which have been specifically marked 2524 * as as unreachable and store them locally. 2525 */ 2526 UNP_LINK_RLOCK(); 2527 for (total = 0, head = heads; *head != NULL; head++) 2528 LIST_FOREACH(unp, *head, unp_link) 2529 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2530 f = unp->unp_file; 2531 if (unp->unp_msgcount == 0 || f == NULL || 2532 f->f_count != unp->unp_msgcount) 2533 continue; 2534 unref[total++] = f; 2535 fhold(f); 2536 KASSERT(total <= unp_unreachable, 2537 ("unp_gc: incorrect unreachable count.")); 2538 } 2539 UNP_LINK_RUNLOCK(); 2540 2541 /* 2542 * Now flush all sockets, free'ing rights. This will free the 2543 * struct files associated with these sockets but leave each socket 2544 * with one remaining ref. 2545 */ 2546 for (i = 0; i < total; i++) { 2547 struct socket *so; 2548 2549 so = unref[i]->f_data; 2550 CURVNET_SET(so->so_vnet); 2551 sorflush(so); 2552 CURVNET_RESTORE(); 2553 } 2554 2555 /* 2556 * And finally release the sockets so they can be reclaimed. 2557 */ 2558 for (i = 0; i < total; i++) 2559 fdrop(unref[i], NULL); 2560 unp_recycled += total; 2561 free(unref, M_TEMP); 2562 } 2563 2564 static void 2565 unp_dispose_mbuf(struct mbuf *m) 2566 { 2567 2568 if (m) 2569 unp_scan(m, unp_freerights); 2570 } 2571 2572 /* 2573 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2574 */ 2575 static void 2576 unp_dispose(struct socket *so) 2577 { 2578 struct unpcb *unp; 2579 2580 unp = sotounpcb(so); 2581 UNP_LINK_WLOCK(); 2582 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2583 UNP_LINK_WUNLOCK(); 2584 if (!SOLISTENING(so)) 2585 unp_dispose_mbuf(so->so_rcv.sb_mb); 2586 } 2587 2588 static void 2589 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2590 { 2591 struct mbuf *m; 2592 struct cmsghdr *cm; 2593 void *data; 2594 socklen_t clen, datalen; 2595 2596 while (m0 != NULL) { 2597 for (m = m0; m; m = m->m_next) { 2598 if (m->m_type != MT_CONTROL) 2599 continue; 2600 2601 cm = mtod(m, struct cmsghdr *); 2602 clen = m->m_len; 2603 2604 while (cm != NULL) { 2605 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2606 break; 2607 2608 data = CMSG_DATA(cm); 2609 datalen = (caddr_t)cm + cm->cmsg_len 2610 - (caddr_t)data; 2611 2612 if (cm->cmsg_level == SOL_SOCKET && 2613 cm->cmsg_type == SCM_RIGHTS) { 2614 (*op)(data, datalen / 2615 sizeof(struct filedescent *)); 2616 } 2617 2618 if (CMSG_SPACE(datalen) < clen) { 2619 clen -= CMSG_SPACE(datalen); 2620 cm = (struct cmsghdr *) 2621 ((caddr_t)cm + CMSG_SPACE(datalen)); 2622 } else { 2623 clen = 0; 2624 cm = NULL; 2625 } 2626 } 2627 } 2628 m0 = m0->m_nextpkt; 2629 } 2630 } 2631 2632 /* 2633 * A helper function called by VFS before socket-type vnode reclamation. 2634 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2635 * use count. 2636 */ 2637 void 2638 vfs_unp_reclaim(struct vnode *vp) 2639 { 2640 struct unpcb *unp; 2641 int active; 2642 struct mtx *vplock; 2643 2644 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2645 KASSERT(vp->v_type == VSOCK, 2646 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2647 2648 active = 0; 2649 vplock = mtx_pool_find(mtxpool_sleep, vp); 2650 mtx_lock(vplock); 2651 VOP_UNP_CONNECT(vp, &unp); 2652 if (unp == NULL) 2653 goto done; 2654 UNP_PCB_LOCK(unp); 2655 if (unp->unp_vnode == vp) { 2656 VOP_UNP_DETACH(vp); 2657 unp->unp_vnode = NULL; 2658 active = 1; 2659 } 2660 UNP_PCB_UNLOCK(unp); 2661 done: 2662 mtx_unlock(vplock); 2663 if (active) 2664 vunref(vp); 2665 } 2666 2667 #ifdef DDB 2668 static void 2669 db_print_indent(int indent) 2670 { 2671 int i; 2672 2673 for (i = 0; i < indent; i++) 2674 db_printf(" "); 2675 } 2676 2677 static void 2678 db_print_unpflags(int unp_flags) 2679 { 2680 int comma; 2681 2682 comma = 0; 2683 if (unp_flags & UNP_HAVEPC) { 2684 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2685 comma = 1; 2686 } 2687 if (unp_flags & UNP_WANTCRED) { 2688 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2689 comma = 1; 2690 } 2691 if (unp_flags & UNP_CONNWAIT) { 2692 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2693 comma = 1; 2694 } 2695 if (unp_flags & UNP_CONNECTING) { 2696 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2697 comma = 1; 2698 } 2699 if (unp_flags & UNP_BINDING) { 2700 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2701 comma = 1; 2702 } 2703 } 2704 2705 static void 2706 db_print_xucred(int indent, struct xucred *xu) 2707 { 2708 int comma, i; 2709 2710 db_print_indent(indent); 2711 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2712 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2713 db_print_indent(indent); 2714 db_printf("cr_groups: "); 2715 comma = 0; 2716 for (i = 0; i < xu->cr_ngroups; i++) { 2717 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2718 comma = 1; 2719 } 2720 db_printf("\n"); 2721 } 2722 2723 static void 2724 db_print_unprefs(int indent, struct unp_head *uh) 2725 { 2726 struct unpcb *unp; 2727 int counter; 2728 2729 counter = 0; 2730 LIST_FOREACH(unp, uh, unp_reflink) { 2731 if (counter % 4 == 0) 2732 db_print_indent(indent); 2733 db_printf("%p ", unp); 2734 if (counter % 4 == 3) 2735 db_printf("\n"); 2736 counter++; 2737 } 2738 if (counter != 0 && counter % 4 != 0) 2739 db_printf("\n"); 2740 } 2741 2742 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2743 { 2744 struct unpcb *unp; 2745 2746 if (!have_addr) { 2747 db_printf("usage: show unpcb <addr>\n"); 2748 return; 2749 } 2750 unp = (struct unpcb *)addr; 2751 2752 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2753 unp->unp_vnode); 2754 2755 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2756 unp->unp_conn); 2757 2758 db_printf("unp_refs:\n"); 2759 db_print_unprefs(2, &unp->unp_refs); 2760 2761 /* XXXRW: Would be nice to print the full address, if any. */ 2762 db_printf("unp_addr: %p\n", unp->unp_addr); 2763 2764 db_printf("unp_gencnt: %llu\n", 2765 (unsigned long long)unp->unp_gencnt); 2766 2767 db_printf("unp_flags: %x (", unp->unp_flags); 2768 db_print_unpflags(unp->unp_flags); 2769 db_printf(")\n"); 2770 2771 db_printf("unp_peercred:\n"); 2772 db_print_xucred(2, &unp->unp_peercred); 2773 2774 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2775 } 2776 #endif 2777