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. All Rights Reserved. 6 * Copyright (c) 2004-2009 Robert N. M. Watson All Rights Reserved. 7 * Copyright (c) 2018 Matthew Macy 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/eventhandler.h> 69 #include <sys/fcntl.h> 70 #include <sys/file.h> 71 #include <sys/filedesc.h> 72 #include <sys/kernel.h> 73 #include <sys/lock.h> 74 #include <sys/malloc.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 * See unpcb.h for the locking key. 110 */ 111 112 static uma_zone_t unp_zone; 113 static unp_gen_t unp_gencnt; /* (l) */ 114 static u_int unp_count; /* (l) Count of local sockets. */ 115 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 116 static int unp_rights; /* (g) File descriptors in flight. */ 117 static struct unp_head unp_shead; /* (l) List of stream sockets. */ 118 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 119 static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */ 120 121 struct unp_defer { 122 SLIST_ENTRY(unp_defer) ud_link; 123 struct file *ud_fp; 124 }; 125 static SLIST_HEAD(, unp_defer) unp_defers; 126 static int unp_defers_count; 127 128 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 129 130 /* 131 * Garbage collection of cyclic file descriptor/socket references occurs 132 * asynchronously in a taskqueue context in order to avoid recursion and 133 * reentrance in the UNIX domain socket, file descriptor, and socket layer 134 * code. See unp_gc() for a full description. 135 */ 136 static struct timeout_task unp_gc_task; 137 138 /* 139 * The close of unix domain sockets attached as SCM_RIGHTS is 140 * postponed to the taskqueue, to avoid arbitrary recursion depth. 141 * The attached sockets might have another sockets attached. 142 */ 143 static struct task unp_defer_task; 144 145 /* 146 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 147 * stream sockets, although the total for sender and receiver is actually 148 * only PIPSIZ. 149 * 150 * Datagram sockets really use the sendspace as the maximum datagram size, 151 * and don't really want to reserve the sendspace. Their recvspace should be 152 * large enough for at least one max-size datagram plus address. 153 */ 154 #ifndef PIPSIZ 155 #define PIPSIZ 8192 156 #endif 157 static u_long unpst_sendspace = PIPSIZ; 158 static u_long unpst_recvspace = PIPSIZ; 159 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 160 static u_long unpdg_recvspace = 16*1024; /* support 8KB syslog msgs */ 161 static u_long unpsp_sendspace = PIPSIZ; /* really max datagram size */ 162 static u_long unpsp_recvspace = PIPSIZ; 163 164 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 165 "Local domain"); 166 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, 167 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 168 "SOCK_STREAM"); 169 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, 170 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 171 "SOCK_DGRAM"); 172 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, 173 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 174 "SOCK_SEQPACKET"); 175 176 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 177 &unpst_sendspace, 0, "Default stream send space."); 178 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 179 &unpst_recvspace, 0, "Default stream receive space."); 180 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 181 &unpdg_sendspace, 0, "Default datagram send space."); 182 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 183 &unpdg_recvspace, 0, "Default datagram receive space."); 184 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW, 185 &unpsp_sendspace, 0, "Default seqpacket send space."); 186 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW, 187 &unpsp_recvspace, 0, "Default seqpacket receive space."); 188 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 189 "File descriptors in flight."); 190 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD, 191 &unp_defers_count, 0, 192 "File descriptors deferred to taskqueue for close."); 193 194 /* 195 * Locking and synchronization: 196 * 197 * Several types of locks exist in the local domain socket implementation: 198 * - a global linkage lock 199 * - a global connection list lock 200 * - the mtxpool lock 201 * - per-unpcb mutexes 202 * 203 * The linkage lock protects the global socket lists, the generation number 204 * counter and garbage collector state. 205 * 206 * The connection list lock protects the list of referring sockets in a datagram 207 * socket PCB. This lock is also overloaded to protect a global list of 208 * sockets whose buffers contain socket references in the form of SCM_RIGHTS 209 * messages. To avoid recursion, such references are released by a dedicated 210 * thread. 211 * 212 * The mtxpool lock protects the vnode from being modified while referenced. 213 * Lock ordering rules require that it be acquired before any PCB locks. 214 * 215 * The unpcb lock (unp_mtx) protects the most commonly referenced fields in the 216 * unpcb. This includes the unp_conn field, which either links two connected 217 * PCBs together (for connected socket types) or points at the destination 218 * socket (for connectionless socket types). The operations of creating or 219 * destroying a connection therefore involve locking multiple PCBs. To avoid 220 * lock order reversals, in some cases this involves dropping a PCB lock and 221 * using a reference counter to maintain liveness. 222 * 223 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 224 * allocated in pru_attach() and freed in pru_detach(). The validity of that 225 * pointer is an invariant, so no lock is required to dereference the so_pcb 226 * pointer if a valid socket reference is held by the caller. In practice, 227 * this is always true during operations performed on a socket. Each unpcb 228 * has a back-pointer to its socket, unp_socket, which will be stable under 229 * the same circumstances. 230 * 231 * This pointer may only be safely dereferenced as long as a valid reference 232 * to the unpcb is held. Typically, this reference will be from the socket, 233 * or from another unpcb when the referring unpcb's lock is held (in order 234 * that the reference not be invalidated during use). For example, to follow 235 * unp->unp_conn->unp_socket, you need to hold a lock on unp_conn to guarantee 236 * that detach is not run clearing unp_socket. 237 * 238 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 239 * protocols, bind() is a non-atomic operation, and connect() requires 240 * potential sleeping in the protocol, due to potentially waiting on local or 241 * distributed file systems. We try to separate "lookup" operations, which 242 * may sleep, and the IPC operations themselves, which typically can occur 243 * with relative atomicity as locks can be held over the entire operation. 244 * 245 * Another tricky issue is simultaneous multi-threaded or multi-process 246 * access to a single UNIX domain socket. These are handled by the flags 247 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 248 * binding, both of which involve dropping UNIX domain socket locks in order 249 * to perform namei() and other file system operations. 250 */ 251 static struct rwlock unp_link_rwlock; 252 static struct mtx unp_defers_lock; 253 254 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 255 "unp_link_rwlock") 256 257 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 258 RA_LOCKED) 259 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 260 RA_UNLOCKED) 261 262 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 263 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 264 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 265 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 266 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 267 RA_WLOCKED) 268 #define UNP_LINK_WOWNED() rw_wowned(&unp_link_rwlock) 269 270 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \ 271 "unp_defer", NULL, MTX_DEF) 272 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock) 273 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock) 274 275 #define UNP_REF_LIST_LOCK() UNP_DEFERRED_LOCK(); 276 #define UNP_REF_LIST_UNLOCK() UNP_DEFERRED_UNLOCK(); 277 278 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 279 "unp", "unp", \ 280 MTX_DUPOK|MTX_DEF) 281 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 282 #define UNP_PCB_LOCKPTR(unp) (&(unp)->unp_mtx) 283 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 284 #define UNP_PCB_TRYLOCK(unp) mtx_trylock(&(unp)->unp_mtx) 285 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 286 #define UNP_PCB_OWNED(unp) mtx_owned(&(unp)->unp_mtx) 287 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 288 #define UNP_PCB_UNLOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_NOTOWNED) 289 290 static int uipc_connect2(struct socket *, struct socket *); 291 static int uipc_ctloutput(struct socket *, struct sockopt *); 292 static int unp_connect(struct socket *, struct sockaddr *, 293 struct thread *); 294 static int unp_connectat(int, struct socket *, struct sockaddr *, 295 struct thread *); 296 static void unp_connect2(struct socket *so, struct socket *so2, int); 297 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 298 static void unp_dispose(struct socket *so); 299 static void unp_shutdown(struct unpcb *); 300 static void unp_drop(struct unpcb *); 301 static void unp_gc(__unused void *, int); 302 static void unp_scan(struct mbuf *, void (*)(struct filedescent **, int)); 303 static void unp_discard(struct file *); 304 static void unp_freerights(struct filedescent **, int); 305 static int unp_internalize(struct mbuf **, struct thread *); 306 static void unp_internalize_fp(struct file *); 307 static int unp_externalize(struct mbuf *, struct mbuf **, int); 308 static int unp_externalize_fp(struct file *); 309 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *, int); 310 static void unp_process_defers(void * __unused, int); 311 312 static void 313 unp_pcb_hold(struct unpcb *unp) 314 { 315 u_int old __unused; 316 317 old = refcount_acquire(&unp->unp_refcount); 318 KASSERT(old > 0, ("%s: unpcb %p has no references", __func__, unp)); 319 } 320 321 static __result_use_check bool 322 unp_pcb_rele(struct unpcb *unp) 323 { 324 bool ret; 325 326 UNP_PCB_LOCK_ASSERT(unp); 327 328 if ((ret = refcount_release(&unp->unp_refcount))) { 329 UNP_PCB_UNLOCK(unp); 330 UNP_PCB_LOCK_DESTROY(unp); 331 uma_zfree(unp_zone, unp); 332 } 333 return (ret); 334 } 335 336 static void 337 unp_pcb_rele_notlast(struct unpcb *unp) 338 { 339 bool ret __unused; 340 341 ret = refcount_release(&unp->unp_refcount); 342 KASSERT(!ret, ("%s: unpcb %p has no references", __func__, unp)); 343 } 344 345 static void 346 unp_pcb_lock_pair(struct unpcb *unp, struct unpcb *unp2) 347 { 348 UNP_PCB_UNLOCK_ASSERT(unp); 349 UNP_PCB_UNLOCK_ASSERT(unp2); 350 351 if (unp == unp2) { 352 UNP_PCB_LOCK(unp); 353 } else if ((uintptr_t)unp2 > (uintptr_t)unp) { 354 UNP_PCB_LOCK(unp); 355 UNP_PCB_LOCK(unp2); 356 } else { 357 UNP_PCB_LOCK(unp2); 358 UNP_PCB_LOCK(unp); 359 } 360 } 361 362 static void 363 unp_pcb_unlock_pair(struct unpcb *unp, struct unpcb *unp2) 364 { 365 UNP_PCB_UNLOCK(unp); 366 if (unp != unp2) 367 UNP_PCB_UNLOCK(unp2); 368 } 369 370 /* 371 * Try to lock the connected peer of an already locked socket. In some cases 372 * this requires that we unlock the current socket. The pairbusy counter is 373 * used to block concurrent connection attempts while the lock is dropped. The 374 * caller must be careful to revalidate PCB state. 375 */ 376 static struct unpcb * 377 unp_pcb_lock_peer(struct unpcb *unp) 378 { 379 struct unpcb *unp2; 380 381 UNP_PCB_LOCK_ASSERT(unp); 382 unp2 = unp->unp_conn; 383 if (unp2 == NULL) 384 return (NULL); 385 if (__predict_false(unp == unp2)) 386 return (unp); 387 388 UNP_PCB_UNLOCK_ASSERT(unp2); 389 390 if (__predict_true(UNP_PCB_TRYLOCK(unp2))) 391 return (unp2); 392 if ((uintptr_t)unp2 > (uintptr_t)unp) { 393 UNP_PCB_LOCK(unp2); 394 return (unp2); 395 } 396 unp->unp_pairbusy++; 397 unp_pcb_hold(unp2); 398 UNP_PCB_UNLOCK(unp); 399 400 UNP_PCB_LOCK(unp2); 401 UNP_PCB_LOCK(unp); 402 KASSERT(unp->unp_conn == unp2 || unp->unp_conn == NULL, 403 ("%s: socket %p was reconnected", __func__, unp)); 404 if (--unp->unp_pairbusy == 0 && (unp->unp_flags & UNP_WAITING) != 0) { 405 unp->unp_flags &= ~UNP_WAITING; 406 wakeup(unp); 407 } 408 if (unp_pcb_rele(unp2)) { 409 /* unp2 is unlocked. */ 410 return (NULL); 411 } 412 if (unp->unp_conn == NULL) { 413 UNP_PCB_UNLOCK(unp2); 414 return (NULL); 415 } 416 return (unp2); 417 } 418 419 /* 420 * Definitions of protocols supported in the LOCAL domain. 421 */ 422 static struct domain localdomain; 423 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 424 static struct pr_usrreqs uipc_usrreqs_seqpacket; 425 static struct protosw localsw[] = { 426 { 427 .pr_type = SOCK_STREAM, 428 .pr_domain = &localdomain, 429 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS| 430 PR_CAPATTACH, 431 .pr_ctloutput = &uipc_ctloutput, 432 .pr_usrreqs = &uipc_usrreqs_stream 433 }, 434 { 435 .pr_type = SOCK_DGRAM, 436 .pr_domain = &localdomain, 437 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS|PR_CAPATTACH, 438 .pr_ctloutput = &uipc_ctloutput, 439 .pr_usrreqs = &uipc_usrreqs_dgram 440 }, 441 { 442 .pr_type = SOCK_SEQPACKET, 443 .pr_domain = &localdomain, 444 445 /* 446 * XXXRW: For now, PR_ADDR because soreceive will bump into them 447 * due to our use of sbappendaddr. A new sbappend variants is needed 448 * that supports both atomic record writes and control data. 449 */ 450 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED| 451 PR_WANTRCVD|PR_RIGHTS|PR_CAPATTACH, 452 .pr_ctloutput = &uipc_ctloutput, 453 .pr_usrreqs = &uipc_usrreqs_seqpacket, 454 }, 455 }; 456 457 static struct domain localdomain = { 458 .dom_family = AF_LOCAL, 459 .dom_name = "local", 460 .dom_externalize = unp_externalize, 461 .dom_dispose = unp_dispose, 462 .dom_protosw = localsw, 463 .dom_protoswNPROTOSW = &localsw[nitems(localsw)] 464 }; 465 DOMAIN_SET(local); 466 467 static void 468 uipc_abort(struct socket *so) 469 { 470 struct unpcb *unp, *unp2; 471 472 unp = sotounpcb(so); 473 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 474 UNP_PCB_UNLOCK_ASSERT(unp); 475 476 UNP_PCB_LOCK(unp); 477 unp2 = unp->unp_conn; 478 if (unp2 != NULL) { 479 unp_pcb_hold(unp2); 480 UNP_PCB_UNLOCK(unp); 481 unp_drop(unp2); 482 } else 483 UNP_PCB_UNLOCK(unp); 484 } 485 486 static int 487 uipc_accept(struct socket *so, struct sockaddr **nam) 488 { 489 struct unpcb *unp, *unp2; 490 const struct sockaddr *sa; 491 492 /* 493 * Pass back name of connected socket, if it was bound and we are 494 * still connected (our peer may have closed already!). 495 */ 496 unp = sotounpcb(so); 497 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 498 499 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 500 UNP_PCB_LOCK(unp); 501 unp2 = unp_pcb_lock_peer(unp); 502 if (unp2 != NULL && unp2->unp_addr != NULL) 503 sa = (struct sockaddr *)unp2->unp_addr; 504 else 505 sa = &sun_noname; 506 bcopy(sa, *nam, sa->sa_len); 507 if (unp2 != NULL) 508 unp_pcb_unlock_pair(unp, unp2); 509 else 510 UNP_PCB_UNLOCK(unp); 511 return (0); 512 } 513 514 static int 515 uipc_attach(struct socket *so, int proto, struct thread *td) 516 { 517 u_long sendspace, recvspace; 518 struct unpcb *unp; 519 int error; 520 bool locked; 521 522 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 523 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 524 switch (so->so_type) { 525 case SOCK_STREAM: 526 sendspace = unpst_sendspace; 527 recvspace = unpst_recvspace; 528 break; 529 530 case SOCK_DGRAM: 531 sendspace = unpdg_sendspace; 532 recvspace = unpdg_recvspace; 533 break; 534 535 case SOCK_SEQPACKET: 536 sendspace = unpsp_sendspace; 537 recvspace = unpsp_recvspace; 538 break; 539 540 default: 541 panic("uipc_attach"); 542 } 543 error = soreserve(so, sendspace, recvspace); 544 if (error) 545 return (error); 546 } 547 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 548 if (unp == NULL) 549 return (ENOBUFS); 550 LIST_INIT(&unp->unp_refs); 551 UNP_PCB_LOCK_INIT(unp); 552 unp->unp_socket = so; 553 so->so_pcb = unp; 554 refcount_init(&unp->unp_refcount, 1); 555 556 if ((locked = UNP_LINK_WOWNED()) == false) 557 UNP_LINK_WLOCK(); 558 559 unp->unp_gencnt = ++unp_gencnt; 560 unp->unp_ino = ++unp_ino; 561 unp_count++; 562 switch (so->so_type) { 563 case SOCK_STREAM: 564 LIST_INSERT_HEAD(&unp_shead, unp, unp_link); 565 break; 566 567 case SOCK_DGRAM: 568 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link); 569 break; 570 571 case SOCK_SEQPACKET: 572 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link); 573 break; 574 575 default: 576 panic("uipc_attach"); 577 } 578 579 if (locked == false) 580 UNP_LINK_WUNLOCK(); 581 582 return (0); 583 } 584 585 static int 586 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td) 587 { 588 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 589 struct vattr vattr; 590 int error, namelen; 591 struct nameidata nd; 592 struct unpcb *unp; 593 struct vnode *vp; 594 struct mount *mp; 595 cap_rights_t rights; 596 char *buf; 597 598 if (nam->sa_family != AF_UNIX) 599 return (EAFNOSUPPORT); 600 601 unp = sotounpcb(so); 602 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 603 604 if (soun->sun_len > sizeof(struct sockaddr_un)) 605 return (EINVAL); 606 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 607 if (namelen <= 0) 608 return (EINVAL); 609 610 /* 611 * We don't allow simultaneous bind() calls on a single UNIX domain 612 * socket, so flag in-progress operations, and return an error if an 613 * operation is already in progress. 614 * 615 * Historically, we have not allowed a socket to be rebound, so this 616 * also returns an error. Not allowing re-binding simplifies the 617 * implementation and avoids a great many possible failure modes. 618 */ 619 UNP_PCB_LOCK(unp); 620 if (unp->unp_vnode != NULL) { 621 UNP_PCB_UNLOCK(unp); 622 return (EINVAL); 623 } 624 if (unp->unp_flags & UNP_BINDING) { 625 UNP_PCB_UNLOCK(unp); 626 return (EALREADY); 627 } 628 unp->unp_flags |= UNP_BINDING; 629 UNP_PCB_UNLOCK(unp); 630 631 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 632 bcopy(soun->sun_path, buf, namelen); 633 buf[namelen] = 0; 634 635 restart: 636 NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE, 637 UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_BINDAT)); 638 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 639 error = namei(&nd); 640 if (error) 641 goto error; 642 vp = nd.ni_vp; 643 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 644 NDFREE_PNBUF(&nd); 645 if (nd.ni_dvp == vp) 646 vrele(nd.ni_dvp); 647 else 648 vput(nd.ni_dvp); 649 if (vp != NULL) { 650 vrele(vp); 651 error = EADDRINUSE; 652 goto error; 653 } 654 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 655 if (error) 656 goto error; 657 goto restart; 658 } 659 VATTR_NULL(&vattr); 660 vattr.va_type = VSOCK; 661 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_pd->pd_cmask); 662 #ifdef MAC 663 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 664 &vattr); 665 #endif 666 if (error == 0) 667 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 668 NDFREE_PNBUF(&nd); 669 if (error) { 670 VOP_VPUT_PAIR(nd.ni_dvp, NULL, true); 671 vn_finished_write(mp); 672 if (error == ERELOOKUP) 673 goto restart; 674 goto error; 675 } 676 vp = nd.ni_vp; 677 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 678 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 679 680 UNP_PCB_LOCK(unp); 681 VOP_UNP_BIND(vp, unp); 682 unp->unp_vnode = vp; 683 unp->unp_addr = soun; 684 unp->unp_flags &= ~UNP_BINDING; 685 UNP_PCB_UNLOCK(unp); 686 vref(vp); 687 VOP_VPUT_PAIR(nd.ni_dvp, &vp, true); 688 vn_finished_write(mp); 689 free(buf, M_TEMP); 690 return (0); 691 692 error: 693 UNP_PCB_LOCK(unp); 694 unp->unp_flags &= ~UNP_BINDING; 695 UNP_PCB_UNLOCK(unp); 696 free(buf, M_TEMP); 697 return (error); 698 } 699 700 static int 701 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 702 { 703 704 return (uipc_bindat(AT_FDCWD, so, nam, td)); 705 } 706 707 static int 708 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 709 { 710 int error; 711 712 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 713 error = unp_connect(so, nam, td); 714 return (error); 715 } 716 717 static int 718 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 719 struct thread *td) 720 { 721 int error; 722 723 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 724 error = unp_connectat(fd, so, nam, td); 725 return (error); 726 } 727 728 static void 729 uipc_close(struct socket *so) 730 { 731 struct unpcb *unp, *unp2; 732 struct vnode *vp = NULL; 733 struct mtx *vplock; 734 735 unp = sotounpcb(so); 736 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 737 738 vplock = NULL; 739 if ((vp = unp->unp_vnode) != NULL) { 740 vplock = mtx_pool_find(mtxpool_sleep, vp); 741 mtx_lock(vplock); 742 } 743 UNP_PCB_LOCK(unp); 744 if (vp && unp->unp_vnode == NULL) { 745 mtx_unlock(vplock); 746 vp = NULL; 747 } 748 if (vp != NULL) { 749 VOP_UNP_DETACH(vp); 750 unp->unp_vnode = NULL; 751 } 752 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 753 unp_disconnect(unp, unp2); 754 else 755 UNP_PCB_UNLOCK(unp); 756 if (vp) { 757 mtx_unlock(vplock); 758 vrele(vp); 759 } 760 } 761 762 static int 763 uipc_connect2(struct socket *so1, struct socket *so2) 764 { 765 struct unpcb *unp, *unp2; 766 767 if (so1->so_type != so2->so_type) 768 return (EPROTOTYPE); 769 770 unp = so1->so_pcb; 771 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 772 unp2 = so2->so_pcb; 773 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 774 unp_pcb_lock_pair(unp, unp2); 775 unp_connect2(so1, so2, PRU_CONNECT2); 776 unp_pcb_unlock_pair(unp, unp2); 777 778 return (0); 779 } 780 781 static void 782 uipc_detach(struct socket *so) 783 { 784 struct unpcb *unp, *unp2; 785 struct mtx *vplock; 786 struct vnode *vp; 787 int local_unp_rights; 788 789 unp = sotounpcb(so); 790 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 791 792 vp = NULL; 793 vplock = NULL; 794 795 UNP_LINK_WLOCK(); 796 LIST_REMOVE(unp, unp_link); 797 if (unp->unp_gcflag & UNPGC_DEAD) 798 LIST_REMOVE(unp, unp_dead); 799 unp->unp_gencnt = ++unp_gencnt; 800 --unp_count; 801 UNP_LINK_WUNLOCK(); 802 803 UNP_PCB_UNLOCK_ASSERT(unp); 804 restart: 805 if ((vp = unp->unp_vnode) != NULL) { 806 vplock = mtx_pool_find(mtxpool_sleep, vp); 807 mtx_lock(vplock); 808 } 809 UNP_PCB_LOCK(unp); 810 if (unp->unp_vnode != vp && unp->unp_vnode != NULL) { 811 if (vplock) 812 mtx_unlock(vplock); 813 UNP_PCB_UNLOCK(unp); 814 goto restart; 815 } 816 if ((vp = unp->unp_vnode) != NULL) { 817 VOP_UNP_DETACH(vp); 818 unp->unp_vnode = NULL; 819 } 820 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 821 unp_disconnect(unp, unp2); 822 else 823 UNP_PCB_UNLOCK(unp); 824 825 UNP_REF_LIST_LOCK(); 826 while (!LIST_EMPTY(&unp->unp_refs)) { 827 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 828 829 unp_pcb_hold(ref); 830 UNP_REF_LIST_UNLOCK(); 831 832 MPASS(ref != unp); 833 UNP_PCB_UNLOCK_ASSERT(ref); 834 unp_drop(ref); 835 UNP_REF_LIST_LOCK(); 836 } 837 UNP_REF_LIST_UNLOCK(); 838 839 UNP_PCB_LOCK(unp); 840 local_unp_rights = unp_rights; 841 unp->unp_socket->so_pcb = NULL; 842 unp->unp_socket = NULL; 843 free(unp->unp_addr, M_SONAME); 844 unp->unp_addr = NULL; 845 if (!unp_pcb_rele(unp)) 846 UNP_PCB_UNLOCK(unp); 847 if (vp) { 848 mtx_unlock(vplock); 849 vrele(vp); 850 } 851 if (local_unp_rights) 852 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 853 } 854 855 static int 856 uipc_disconnect(struct socket *so) 857 { 858 struct unpcb *unp, *unp2; 859 860 unp = sotounpcb(so); 861 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 862 863 UNP_PCB_LOCK(unp); 864 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 865 unp_disconnect(unp, unp2); 866 else 867 UNP_PCB_UNLOCK(unp); 868 return (0); 869 } 870 871 static int 872 uipc_listen(struct socket *so, int backlog, struct thread *td) 873 { 874 struct unpcb *unp; 875 int error; 876 877 MPASS(so->so_type != SOCK_DGRAM); 878 879 /* 880 * Synchronize with concurrent connection attempts. 881 */ 882 error = 0; 883 unp = sotounpcb(so); 884 UNP_PCB_LOCK(unp); 885 if (unp->unp_conn != NULL || (unp->unp_flags & UNP_CONNECTING) != 0) 886 error = EINVAL; 887 else if (unp->unp_vnode == NULL) 888 error = EDESTADDRREQ; 889 if (error != 0) { 890 UNP_PCB_UNLOCK(unp); 891 return (error); 892 } 893 894 SOCK_LOCK(so); 895 error = solisten_proto_check(so); 896 if (error == 0) { 897 cru2xt(td, &unp->unp_peercred); 898 solisten_proto(so, backlog); 899 } 900 SOCK_UNLOCK(so); 901 UNP_PCB_UNLOCK(unp); 902 return (error); 903 } 904 905 static int 906 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 907 { 908 struct unpcb *unp, *unp2; 909 const struct sockaddr *sa; 910 911 unp = sotounpcb(so); 912 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 913 914 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 915 UNP_LINK_RLOCK(); 916 /* 917 * XXX: It seems that this test always fails even when connection is 918 * established. So, this else clause is added as workaround to 919 * return PF_LOCAL sockaddr. 920 */ 921 unp2 = unp->unp_conn; 922 if (unp2 != NULL) { 923 UNP_PCB_LOCK(unp2); 924 if (unp2->unp_addr != NULL) 925 sa = (struct sockaddr *) unp2->unp_addr; 926 else 927 sa = &sun_noname; 928 bcopy(sa, *nam, sa->sa_len); 929 UNP_PCB_UNLOCK(unp2); 930 } else { 931 sa = &sun_noname; 932 bcopy(sa, *nam, sa->sa_len); 933 } 934 UNP_LINK_RUNLOCK(); 935 return (0); 936 } 937 938 static int 939 uipc_rcvd(struct socket *so, int flags) 940 { 941 struct unpcb *unp, *unp2; 942 struct socket *so2; 943 u_int mbcnt, sbcc; 944 945 unp = sotounpcb(so); 946 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 947 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 948 ("%s: socktype %d", __func__, so->so_type)); 949 950 /* 951 * Adjust backpressure on sender and wakeup any waiting to write. 952 * 953 * The unp lock is acquired to maintain the validity of the unp_conn 954 * pointer; no lock on unp2 is required as unp2->unp_socket will be 955 * static as long as we don't permit unp2 to disconnect from unp, 956 * which is prevented by the lock on unp. We cache values from 957 * so_rcv to avoid holding the so_rcv lock over the entire 958 * transaction on the remote so_snd. 959 */ 960 SOCKBUF_LOCK(&so->so_rcv); 961 mbcnt = so->so_rcv.sb_mbcnt; 962 sbcc = sbavail(&so->so_rcv); 963 SOCKBUF_UNLOCK(&so->so_rcv); 964 /* 965 * There is a benign race condition at this point. If we're planning to 966 * clear SB_STOP, but uipc_send is called on the connected socket at 967 * this instant, it might add data to the sockbuf and set SB_STOP. Then 968 * we would erroneously clear SB_STOP below, even though the sockbuf is 969 * full. The race is benign because the only ill effect is to allow the 970 * sockbuf to exceed its size limit, and the size limits are not 971 * strictly guaranteed anyway. 972 */ 973 UNP_PCB_LOCK(unp); 974 unp2 = unp->unp_conn; 975 if (unp2 == NULL) { 976 UNP_PCB_UNLOCK(unp); 977 return (0); 978 } 979 so2 = unp2->unp_socket; 980 SOCKBUF_LOCK(&so2->so_snd); 981 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 982 so2->so_snd.sb_flags &= ~SB_STOP; 983 sowwakeup_locked(so2); 984 UNP_PCB_UNLOCK(unp); 985 return (0); 986 } 987 988 static int 989 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 990 struct mbuf *control, struct thread *td) 991 { 992 struct unpcb *unp, *unp2; 993 struct socket *so2; 994 u_int mbcnt, sbcc; 995 int error; 996 997 unp = sotounpcb(so); 998 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 999 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 1000 so->so_type == SOCK_SEQPACKET, 1001 ("%s: socktype %d", __func__, so->so_type)); 1002 1003 error = 0; 1004 if (flags & PRUS_OOB) { 1005 error = EOPNOTSUPP; 1006 goto release; 1007 } 1008 if (control != NULL && (error = unp_internalize(&control, td))) 1009 goto release; 1010 1011 unp2 = NULL; 1012 switch (so->so_type) { 1013 case SOCK_DGRAM: 1014 { 1015 const struct sockaddr *from; 1016 1017 if (nam != NULL) { 1018 error = unp_connect(so, nam, td); 1019 if (error != 0) 1020 break; 1021 } 1022 UNP_PCB_LOCK(unp); 1023 1024 /* 1025 * Because connect() and send() are non-atomic in a sendto() 1026 * with a target address, it's possible that the socket will 1027 * have disconnected before the send() can run. In that case 1028 * return the slightly counter-intuitive but otherwise 1029 * correct error that the socket is not connected. 1030 */ 1031 unp2 = unp_pcb_lock_peer(unp); 1032 if (unp2 == NULL) { 1033 UNP_PCB_UNLOCK(unp); 1034 error = ENOTCONN; 1035 break; 1036 } 1037 1038 if (unp2->unp_flags & UNP_WANTCRED_MASK) 1039 control = unp_addsockcred(td, control, 1040 unp2->unp_flags); 1041 if (unp->unp_addr != NULL) 1042 from = (struct sockaddr *)unp->unp_addr; 1043 else 1044 from = &sun_noname; 1045 so2 = unp2->unp_socket; 1046 SOCKBUF_LOCK(&so2->so_rcv); 1047 if (sbappendaddr_locked(&so2->so_rcv, from, m, 1048 control)) { 1049 sorwakeup_locked(so2); 1050 m = NULL; 1051 control = NULL; 1052 } else { 1053 soroverflow_locked(so2); 1054 error = (so->so_state & SS_NBIO) ? EAGAIN : ENOBUFS; 1055 } 1056 if (nam != NULL) 1057 unp_disconnect(unp, unp2); 1058 else 1059 unp_pcb_unlock_pair(unp, unp2); 1060 break; 1061 } 1062 1063 case SOCK_SEQPACKET: 1064 case SOCK_STREAM: 1065 if ((so->so_state & SS_ISCONNECTED) == 0) { 1066 if (nam != NULL) { 1067 error = unp_connect(so, nam, td); 1068 if (error != 0) 1069 break; 1070 } else { 1071 error = ENOTCONN; 1072 break; 1073 } 1074 } 1075 1076 UNP_PCB_LOCK(unp); 1077 if ((unp2 = unp_pcb_lock_peer(unp)) == NULL) { 1078 UNP_PCB_UNLOCK(unp); 1079 error = ENOTCONN; 1080 break; 1081 } else if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 1082 unp_pcb_unlock_pair(unp, unp2); 1083 error = EPIPE; 1084 break; 1085 } 1086 UNP_PCB_UNLOCK(unp); 1087 if ((so2 = unp2->unp_socket) == NULL) { 1088 UNP_PCB_UNLOCK(unp2); 1089 error = ENOTCONN; 1090 break; 1091 } 1092 SOCKBUF_LOCK(&so2->so_rcv); 1093 if (unp2->unp_flags & UNP_WANTCRED_MASK) { 1094 /* 1095 * Credentials are passed only once on SOCK_STREAM and 1096 * SOCK_SEQPACKET (LOCAL_CREDS => WANTCRED_ONESHOT), or 1097 * forever (LOCAL_CREDS_PERSISTENT => WANTCRED_ALWAYS). 1098 */ 1099 control = unp_addsockcred(td, control, unp2->unp_flags); 1100 unp2->unp_flags &= ~UNP_WANTCRED_ONESHOT; 1101 } 1102 1103 /* 1104 * Send to paired receive port and wake up readers. Don't 1105 * check for space available in the receive buffer if we're 1106 * attaching ancillary data; Unix domain sockets only check 1107 * for space in the sending sockbuf, and that check is 1108 * performed one level up the stack. At that level we cannot 1109 * precisely account for the amount of buffer space used 1110 * (e.g., because control messages are not yet internalized). 1111 */ 1112 switch (so->so_type) { 1113 case SOCK_STREAM: 1114 if (control != NULL) { 1115 sbappendcontrol_locked(&so2->so_rcv, m, 1116 control, flags); 1117 control = NULL; 1118 } else 1119 sbappend_locked(&so2->so_rcv, m, flags); 1120 break; 1121 1122 case SOCK_SEQPACKET: 1123 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 1124 &sun_noname, m, control)) 1125 control = NULL; 1126 break; 1127 } 1128 1129 mbcnt = so2->so_rcv.sb_mbcnt; 1130 sbcc = sbavail(&so2->so_rcv); 1131 if (sbcc) 1132 sorwakeup_locked(so2); 1133 else 1134 SOCKBUF_UNLOCK(&so2->so_rcv); 1135 1136 /* 1137 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1138 * it would be possible for uipc_rcvd to be called at this 1139 * point, drain the receiving sockbuf, clear SB_STOP, and then 1140 * we would set SB_STOP below. That could lead to an empty 1141 * sockbuf having SB_STOP set 1142 */ 1143 SOCKBUF_LOCK(&so->so_snd); 1144 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1145 so->so_snd.sb_flags |= SB_STOP; 1146 SOCKBUF_UNLOCK(&so->so_snd); 1147 UNP_PCB_UNLOCK(unp2); 1148 m = NULL; 1149 break; 1150 } 1151 1152 /* 1153 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1154 */ 1155 if (flags & PRUS_EOF) { 1156 UNP_PCB_LOCK(unp); 1157 socantsendmore(so); 1158 unp_shutdown(unp); 1159 UNP_PCB_UNLOCK(unp); 1160 } 1161 if (control != NULL && error != 0) 1162 unp_scan(control, unp_freerights); 1163 1164 release: 1165 if (control != NULL) 1166 m_freem(control); 1167 /* 1168 * In case of PRUS_NOTREADY, uipc_ready() is responsible 1169 * for freeing memory. 1170 */ 1171 if (m != NULL && (flags & PRUS_NOTREADY) == 0) 1172 m_freem(m); 1173 return (error); 1174 } 1175 1176 static bool 1177 uipc_ready_scan(struct socket *so, struct mbuf *m, int count, int *errorp) 1178 { 1179 struct mbuf *mb, *n; 1180 struct sockbuf *sb; 1181 1182 SOCK_LOCK(so); 1183 if (SOLISTENING(so)) { 1184 SOCK_UNLOCK(so); 1185 return (false); 1186 } 1187 mb = NULL; 1188 sb = &so->so_rcv; 1189 SOCKBUF_LOCK(sb); 1190 if (sb->sb_fnrdy != NULL) { 1191 for (mb = sb->sb_mb, n = mb->m_nextpkt; mb != NULL;) { 1192 if (mb == m) { 1193 *errorp = sbready(sb, m, count); 1194 break; 1195 } 1196 mb = mb->m_next; 1197 if (mb == NULL) { 1198 mb = n; 1199 if (mb != NULL) 1200 n = mb->m_nextpkt; 1201 } 1202 } 1203 } 1204 SOCKBUF_UNLOCK(sb); 1205 SOCK_UNLOCK(so); 1206 return (mb != NULL); 1207 } 1208 1209 static int 1210 uipc_ready(struct socket *so, struct mbuf *m, int count) 1211 { 1212 struct unpcb *unp, *unp2; 1213 struct socket *so2; 1214 int error, i; 1215 1216 unp = sotounpcb(so); 1217 1218 KASSERT(so->so_type == SOCK_STREAM, 1219 ("%s: unexpected socket type for %p", __func__, so)); 1220 1221 UNP_PCB_LOCK(unp); 1222 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) { 1223 UNP_PCB_UNLOCK(unp); 1224 so2 = unp2->unp_socket; 1225 SOCKBUF_LOCK(&so2->so_rcv); 1226 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1227 sorwakeup_locked(so2); 1228 else 1229 SOCKBUF_UNLOCK(&so2->so_rcv); 1230 UNP_PCB_UNLOCK(unp2); 1231 return (error); 1232 } 1233 UNP_PCB_UNLOCK(unp); 1234 1235 /* 1236 * The receiving socket has been disconnected, but may still be valid. 1237 * In this case, the now-ready mbufs are still present in its socket 1238 * buffer, so perform an exhaustive search before giving up and freeing 1239 * the mbufs. 1240 */ 1241 UNP_LINK_RLOCK(); 1242 LIST_FOREACH(unp, &unp_shead, unp_link) { 1243 if (uipc_ready_scan(unp->unp_socket, m, count, &error)) 1244 break; 1245 } 1246 UNP_LINK_RUNLOCK(); 1247 1248 if (unp == NULL) { 1249 for (i = 0; i < count; i++) 1250 m = m_free(m); 1251 error = ECONNRESET; 1252 } 1253 return (error); 1254 } 1255 1256 static int 1257 uipc_sense(struct socket *so, struct stat *sb) 1258 { 1259 struct unpcb *unp; 1260 1261 unp = sotounpcb(so); 1262 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1263 1264 sb->st_blksize = so->so_snd.sb_hiwat; 1265 sb->st_dev = NODEV; 1266 sb->st_ino = unp->unp_ino; 1267 return (0); 1268 } 1269 1270 static int 1271 uipc_shutdown(struct socket *so) 1272 { 1273 struct unpcb *unp; 1274 1275 unp = sotounpcb(so); 1276 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1277 1278 UNP_PCB_LOCK(unp); 1279 socantsendmore(so); 1280 unp_shutdown(unp); 1281 UNP_PCB_UNLOCK(unp); 1282 return (0); 1283 } 1284 1285 static int 1286 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1287 { 1288 struct unpcb *unp; 1289 const struct sockaddr *sa; 1290 1291 unp = sotounpcb(so); 1292 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1293 1294 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1295 UNP_PCB_LOCK(unp); 1296 if (unp->unp_addr != NULL) 1297 sa = (struct sockaddr *) unp->unp_addr; 1298 else 1299 sa = &sun_noname; 1300 bcopy(sa, *nam, sa->sa_len); 1301 UNP_PCB_UNLOCK(unp); 1302 return (0); 1303 } 1304 1305 static struct pr_usrreqs uipc_usrreqs_dgram = { 1306 .pru_abort = uipc_abort, 1307 .pru_accept = uipc_accept, 1308 .pru_attach = uipc_attach, 1309 .pru_bind = uipc_bind, 1310 .pru_bindat = uipc_bindat, 1311 .pru_connect = uipc_connect, 1312 .pru_connectat = uipc_connectat, 1313 .pru_connect2 = uipc_connect2, 1314 .pru_detach = uipc_detach, 1315 .pru_disconnect = uipc_disconnect, 1316 .pru_peeraddr = uipc_peeraddr, 1317 .pru_send = uipc_send, 1318 .pru_sense = uipc_sense, 1319 .pru_shutdown = uipc_shutdown, 1320 .pru_sockaddr = uipc_sockaddr, 1321 .pru_soreceive = soreceive_dgram, 1322 .pru_close = uipc_close, 1323 }; 1324 1325 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1326 .pru_abort = uipc_abort, 1327 .pru_accept = uipc_accept, 1328 .pru_attach = uipc_attach, 1329 .pru_bind = uipc_bind, 1330 .pru_bindat = uipc_bindat, 1331 .pru_connect = uipc_connect, 1332 .pru_connectat = uipc_connectat, 1333 .pru_connect2 = uipc_connect2, 1334 .pru_detach = uipc_detach, 1335 .pru_disconnect = uipc_disconnect, 1336 .pru_listen = uipc_listen, 1337 .pru_peeraddr = uipc_peeraddr, 1338 .pru_rcvd = uipc_rcvd, 1339 .pru_send = uipc_send, 1340 .pru_sense = uipc_sense, 1341 .pru_shutdown = uipc_shutdown, 1342 .pru_sockaddr = uipc_sockaddr, 1343 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1344 .pru_close = uipc_close, 1345 }; 1346 1347 static struct pr_usrreqs uipc_usrreqs_stream = { 1348 .pru_abort = uipc_abort, 1349 .pru_accept = uipc_accept, 1350 .pru_attach = uipc_attach, 1351 .pru_bind = uipc_bind, 1352 .pru_bindat = uipc_bindat, 1353 .pru_connect = uipc_connect, 1354 .pru_connectat = uipc_connectat, 1355 .pru_connect2 = uipc_connect2, 1356 .pru_detach = uipc_detach, 1357 .pru_disconnect = uipc_disconnect, 1358 .pru_listen = uipc_listen, 1359 .pru_peeraddr = uipc_peeraddr, 1360 .pru_rcvd = uipc_rcvd, 1361 .pru_send = uipc_send, 1362 .pru_ready = uipc_ready, 1363 .pru_sense = uipc_sense, 1364 .pru_shutdown = uipc_shutdown, 1365 .pru_sockaddr = uipc_sockaddr, 1366 .pru_soreceive = soreceive_generic, 1367 .pru_close = uipc_close, 1368 }; 1369 1370 static int 1371 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1372 { 1373 struct unpcb *unp; 1374 struct xucred xu; 1375 int error, optval; 1376 1377 if (sopt->sopt_level != SOL_LOCAL) 1378 return (EINVAL); 1379 1380 unp = sotounpcb(so); 1381 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1382 error = 0; 1383 switch (sopt->sopt_dir) { 1384 case SOPT_GET: 1385 switch (sopt->sopt_name) { 1386 case LOCAL_PEERCRED: 1387 UNP_PCB_LOCK(unp); 1388 if (unp->unp_flags & UNP_HAVEPC) 1389 xu = unp->unp_peercred; 1390 else { 1391 if (so->so_type == SOCK_STREAM) 1392 error = ENOTCONN; 1393 else 1394 error = EINVAL; 1395 } 1396 UNP_PCB_UNLOCK(unp); 1397 if (error == 0) 1398 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1399 break; 1400 1401 case LOCAL_CREDS: 1402 /* Unlocked read. */ 1403 optval = unp->unp_flags & UNP_WANTCRED_ONESHOT ? 1 : 0; 1404 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1405 break; 1406 1407 case LOCAL_CREDS_PERSISTENT: 1408 /* Unlocked read. */ 1409 optval = unp->unp_flags & UNP_WANTCRED_ALWAYS ? 1 : 0; 1410 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1411 break; 1412 1413 case LOCAL_CONNWAIT: 1414 /* Unlocked read. */ 1415 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1416 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1417 break; 1418 1419 default: 1420 error = EOPNOTSUPP; 1421 break; 1422 } 1423 break; 1424 1425 case SOPT_SET: 1426 switch (sopt->sopt_name) { 1427 case LOCAL_CREDS: 1428 case LOCAL_CREDS_PERSISTENT: 1429 case LOCAL_CONNWAIT: 1430 error = sooptcopyin(sopt, &optval, sizeof(optval), 1431 sizeof(optval)); 1432 if (error) 1433 break; 1434 1435 #define OPTSET(bit, exclusive) do { \ 1436 UNP_PCB_LOCK(unp); \ 1437 if (optval) { \ 1438 if ((unp->unp_flags & (exclusive)) != 0) { \ 1439 UNP_PCB_UNLOCK(unp); \ 1440 error = EINVAL; \ 1441 break; \ 1442 } \ 1443 unp->unp_flags |= (bit); \ 1444 } else \ 1445 unp->unp_flags &= ~(bit); \ 1446 UNP_PCB_UNLOCK(unp); \ 1447 } while (0) 1448 1449 switch (sopt->sopt_name) { 1450 case LOCAL_CREDS: 1451 OPTSET(UNP_WANTCRED_ONESHOT, UNP_WANTCRED_ALWAYS); 1452 break; 1453 1454 case LOCAL_CREDS_PERSISTENT: 1455 OPTSET(UNP_WANTCRED_ALWAYS, UNP_WANTCRED_ONESHOT); 1456 break; 1457 1458 case LOCAL_CONNWAIT: 1459 OPTSET(UNP_CONNWAIT, 0); 1460 break; 1461 1462 default: 1463 break; 1464 } 1465 break; 1466 #undef OPTSET 1467 default: 1468 error = ENOPROTOOPT; 1469 break; 1470 } 1471 break; 1472 1473 default: 1474 error = EOPNOTSUPP; 1475 break; 1476 } 1477 return (error); 1478 } 1479 1480 static int 1481 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1482 { 1483 1484 return (unp_connectat(AT_FDCWD, so, nam, td)); 1485 } 1486 1487 static int 1488 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1489 struct thread *td) 1490 { 1491 struct mtx *vplock; 1492 struct sockaddr_un *soun; 1493 struct vnode *vp; 1494 struct socket *so2; 1495 struct unpcb *unp, *unp2, *unp3; 1496 struct nameidata nd; 1497 char buf[SOCK_MAXADDRLEN]; 1498 struct sockaddr *sa; 1499 cap_rights_t rights; 1500 int error, len; 1501 bool connreq; 1502 1503 if (nam->sa_family != AF_UNIX) 1504 return (EAFNOSUPPORT); 1505 if (nam->sa_len > sizeof(struct sockaddr_un)) 1506 return (EINVAL); 1507 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1508 if (len <= 0) 1509 return (EINVAL); 1510 soun = (struct sockaddr_un *)nam; 1511 bcopy(soun->sun_path, buf, len); 1512 buf[len] = 0; 1513 1514 error = 0; 1515 unp = sotounpcb(so); 1516 UNP_PCB_LOCK(unp); 1517 for (;;) { 1518 /* 1519 * Wait for connection state to stabilize. If a connection 1520 * already exists, give up. For datagram sockets, which permit 1521 * multiple consecutive connect(2) calls, upper layers are 1522 * responsible for disconnecting in advance of a subsequent 1523 * connect(2), but this is not synchronized with PCB connection 1524 * state. 1525 * 1526 * Also make sure that no threads are currently attempting to 1527 * lock the peer socket, to ensure that unp_conn cannot 1528 * transition between two valid sockets while locks are dropped. 1529 */ 1530 if (SOLISTENING(so)) 1531 error = EOPNOTSUPP; 1532 else if (unp->unp_conn != NULL) 1533 error = EISCONN; 1534 else if ((unp->unp_flags & UNP_CONNECTING) != 0) { 1535 error = EALREADY; 1536 } 1537 if (error != 0) { 1538 UNP_PCB_UNLOCK(unp); 1539 return (error); 1540 } 1541 if (unp->unp_pairbusy > 0) { 1542 unp->unp_flags |= UNP_WAITING; 1543 mtx_sleep(unp, UNP_PCB_LOCKPTR(unp), 0, "unpeer", 0); 1544 continue; 1545 } 1546 break; 1547 } 1548 unp->unp_flags |= UNP_CONNECTING; 1549 UNP_PCB_UNLOCK(unp); 1550 1551 connreq = (so->so_proto->pr_flags & PR_CONNREQUIRED) != 0; 1552 if (connreq) 1553 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1554 else 1555 sa = NULL; 1556 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1557 UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_CONNECTAT)); 1558 error = namei(&nd); 1559 if (error) 1560 vp = NULL; 1561 else 1562 vp = nd.ni_vp; 1563 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1564 NDFREE_NOTHING(&nd); 1565 if (error) 1566 goto bad; 1567 1568 if (vp->v_type != VSOCK) { 1569 error = ENOTSOCK; 1570 goto bad; 1571 } 1572 #ifdef MAC 1573 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1574 if (error) 1575 goto bad; 1576 #endif 1577 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1578 if (error) 1579 goto bad; 1580 1581 unp = sotounpcb(so); 1582 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1583 1584 vplock = mtx_pool_find(mtxpool_sleep, vp); 1585 mtx_lock(vplock); 1586 VOP_UNP_CONNECT(vp, &unp2); 1587 if (unp2 == NULL) { 1588 error = ECONNREFUSED; 1589 goto bad2; 1590 } 1591 so2 = unp2->unp_socket; 1592 if (so->so_type != so2->so_type) { 1593 error = EPROTOTYPE; 1594 goto bad2; 1595 } 1596 if (connreq) { 1597 if (SOLISTENING(so2)) { 1598 CURVNET_SET(so2->so_vnet); 1599 so2 = sonewconn(so2, 0); 1600 CURVNET_RESTORE(); 1601 } else 1602 so2 = NULL; 1603 if (so2 == NULL) { 1604 error = ECONNREFUSED; 1605 goto bad2; 1606 } 1607 unp3 = sotounpcb(so2); 1608 unp_pcb_lock_pair(unp2, unp3); 1609 if (unp2->unp_addr != NULL) { 1610 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1611 unp3->unp_addr = (struct sockaddr_un *) sa; 1612 sa = NULL; 1613 } 1614 1615 unp_copy_peercred(td, unp3, unp, unp2); 1616 1617 UNP_PCB_UNLOCK(unp2); 1618 unp2 = unp3; 1619 1620 /* 1621 * It is safe to block on the PCB lock here since unp2 is 1622 * nascent and cannot be connected to any other sockets. 1623 */ 1624 UNP_PCB_LOCK(unp); 1625 #ifdef MAC 1626 mac_socketpeer_set_from_socket(so, so2); 1627 mac_socketpeer_set_from_socket(so2, so); 1628 #endif 1629 } else { 1630 unp_pcb_lock_pair(unp, unp2); 1631 } 1632 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1633 sotounpcb(so2) == unp2, 1634 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1635 unp_connect2(so, so2, PRU_CONNECT); 1636 KASSERT((unp->unp_flags & UNP_CONNECTING) != 0, 1637 ("%s: unp %p has UNP_CONNECTING clear", __func__, unp)); 1638 unp->unp_flags &= ~UNP_CONNECTING; 1639 unp_pcb_unlock_pair(unp, unp2); 1640 bad2: 1641 mtx_unlock(vplock); 1642 bad: 1643 if (vp != NULL) { 1644 vput(vp); 1645 } 1646 free(sa, M_SONAME); 1647 if (__predict_false(error)) { 1648 UNP_PCB_LOCK(unp); 1649 KASSERT((unp->unp_flags & UNP_CONNECTING) != 0, 1650 ("%s: unp %p has UNP_CONNECTING clear", __func__, unp)); 1651 unp->unp_flags &= ~UNP_CONNECTING; 1652 UNP_PCB_UNLOCK(unp); 1653 } 1654 return (error); 1655 } 1656 1657 /* 1658 * Set socket peer credentials at connection time. 1659 * 1660 * The client's PCB credentials are copied from its process structure. The 1661 * server's PCB credentials are copied from the socket on which it called 1662 * listen(2). uipc_listen cached that process's credentials at the time. 1663 */ 1664 void 1665 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 1666 struct unpcb *server_unp, struct unpcb *listen_unp) 1667 { 1668 cru2xt(td, &client_unp->unp_peercred); 1669 client_unp->unp_flags |= UNP_HAVEPC; 1670 1671 memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred, 1672 sizeof(server_unp->unp_peercred)); 1673 server_unp->unp_flags |= UNP_HAVEPC; 1674 client_unp->unp_flags |= (listen_unp->unp_flags & UNP_WANTCRED_MASK); 1675 } 1676 1677 static void 1678 unp_connect2(struct socket *so, struct socket *so2, int req) 1679 { 1680 struct unpcb *unp; 1681 struct unpcb *unp2; 1682 1683 MPASS(so2->so_type == so->so_type); 1684 unp = sotounpcb(so); 1685 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1686 unp2 = sotounpcb(so2); 1687 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1688 1689 UNP_PCB_LOCK_ASSERT(unp); 1690 UNP_PCB_LOCK_ASSERT(unp2); 1691 KASSERT(unp->unp_conn == NULL, 1692 ("%s: socket %p is already connected", __func__, unp)); 1693 1694 unp->unp_conn = unp2; 1695 unp_pcb_hold(unp2); 1696 unp_pcb_hold(unp); 1697 switch (so->so_type) { 1698 case SOCK_DGRAM: 1699 UNP_REF_LIST_LOCK(); 1700 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1701 UNP_REF_LIST_UNLOCK(); 1702 soisconnected(so); 1703 break; 1704 1705 case SOCK_STREAM: 1706 case SOCK_SEQPACKET: 1707 KASSERT(unp2->unp_conn == NULL, 1708 ("%s: socket %p is already connected", __func__, unp2)); 1709 unp2->unp_conn = unp; 1710 if (req == PRU_CONNECT && 1711 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1712 soisconnecting(so); 1713 else 1714 soisconnected(so); 1715 soisconnected(so2); 1716 break; 1717 1718 default: 1719 panic("unp_connect2"); 1720 } 1721 } 1722 1723 static void 1724 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1725 { 1726 struct socket *so, *so2; 1727 #ifdef INVARIANTS 1728 struct unpcb *unptmp; 1729 #endif 1730 1731 UNP_PCB_LOCK_ASSERT(unp); 1732 UNP_PCB_LOCK_ASSERT(unp2); 1733 KASSERT(unp->unp_conn == unp2, 1734 ("%s: unpcb %p is not connected to %p", __func__, unp, unp2)); 1735 1736 unp->unp_conn = NULL; 1737 so = unp->unp_socket; 1738 so2 = unp2->unp_socket; 1739 switch (unp->unp_socket->so_type) { 1740 case SOCK_DGRAM: 1741 UNP_REF_LIST_LOCK(); 1742 #ifdef INVARIANTS 1743 LIST_FOREACH(unptmp, &unp2->unp_refs, unp_reflink) { 1744 if (unptmp == unp) 1745 break; 1746 } 1747 KASSERT(unptmp != NULL, 1748 ("%s: %p not found in reflist of %p", __func__, unp, unp2)); 1749 #endif 1750 LIST_REMOVE(unp, unp_reflink); 1751 UNP_REF_LIST_UNLOCK(); 1752 if (so) { 1753 SOCK_LOCK(so); 1754 so->so_state &= ~SS_ISCONNECTED; 1755 SOCK_UNLOCK(so); 1756 } 1757 break; 1758 1759 case SOCK_STREAM: 1760 case SOCK_SEQPACKET: 1761 if (so) 1762 soisdisconnected(so); 1763 MPASS(unp2->unp_conn == unp); 1764 unp2->unp_conn = NULL; 1765 if (so2) 1766 soisdisconnected(so2); 1767 break; 1768 } 1769 1770 if (unp == unp2) { 1771 unp_pcb_rele_notlast(unp); 1772 if (!unp_pcb_rele(unp)) 1773 UNP_PCB_UNLOCK(unp); 1774 } else { 1775 if (!unp_pcb_rele(unp)) 1776 UNP_PCB_UNLOCK(unp); 1777 if (!unp_pcb_rele(unp2)) 1778 UNP_PCB_UNLOCK(unp2); 1779 } 1780 } 1781 1782 /* 1783 * unp_pcblist() walks the global list of struct unpcb's to generate a 1784 * pointer list, bumping the refcount on each unpcb. It then copies them out 1785 * sequentially, validating the generation number on each to see if it has 1786 * been detached. All of this is necessary because copyout() may sleep on 1787 * disk I/O. 1788 */ 1789 static int 1790 unp_pcblist(SYSCTL_HANDLER_ARGS) 1791 { 1792 struct unpcb *unp, **unp_list; 1793 unp_gen_t gencnt; 1794 struct xunpgen *xug; 1795 struct unp_head *head; 1796 struct xunpcb *xu; 1797 u_int i; 1798 int error, n; 1799 1800 switch ((intptr_t)arg1) { 1801 case SOCK_STREAM: 1802 head = &unp_shead; 1803 break; 1804 1805 case SOCK_DGRAM: 1806 head = &unp_dhead; 1807 break; 1808 1809 case SOCK_SEQPACKET: 1810 head = &unp_sphead; 1811 break; 1812 1813 default: 1814 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1815 } 1816 1817 /* 1818 * The process of preparing the PCB list is too time-consuming and 1819 * resource-intensive to repeat twice on every request. 1820 */ 1821 if (req->oldptr == NULL) { 1822 n = unp_count; 1823 req->oldidx = 2 * (sizeof *xug) 1824 + (n + n/8) * sizeof(struct xunpcb); 1825 return (0); 1826 } 1827 1828 if (req->newptr != NULL) 1829 return (EPERM); 1830 1831 /* 1832 * OK, now we're committed to doing something. 1833 */ 1834 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK | M_ZERO); 1835 UNP_LINK_RLOCK(); 1836 gencnt = unp_gencnt; 1837 n = unp_count; 1838 UNP_LINK_RUNLOCK(); 1839 1840 xug->xug_len = sizeof *xug; 1841 xug->xug_count = n; 1842 xug->xug_gen = gencnt; 1843 xug->xug_sogen = so_gencnt; 1844 error = SYSCTL_OUT(req, xug, sizeof *xug); 1845 if (error) { 1846 free(xug, M_TEMP); 1847 return (error); 1848 } 1849 1850 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1851 1852 UNP_LINK_RLOCK(); 1853 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1854 unp = LIST_NEXT(unp, unp_link)) { 1855 UNP_PCB_LOCK(unp); 1856 if (unp->unp_gencnt <= gencnt) { 1857 if (cr_cansee(req->td->td_ucred, 1858 unp->unp_socket->so_cred)) { 1859 UNP_PCB_UNLOCK(unp); 1860 continue; 1861 } 1862 unp_list[i++] = unp; 1863 unp_pcb_hold(unp); 1864 } 1865 UNP_PCB_UNLOCK(unp); 1866 } 1867 UNP_LINK_RUNLOCK(); 1868 n = i; /* In case we lost some during malloc. */ 1869 1870 error = 0; 1871 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1872 for (i = 0; i < n; i++) { 1873 unp = unp_list[i]; 1874 UNP_PCB_LOCK(unp); 1875 if (unp_pcb_rele(unp)) 1876 continue; 1877 1878 if (unp->unp_gencnt <= gencnt) { 1879 xu->xu_len = sizeof *xu; 1880 xu->xu_unpp = (uintptr_t)unp; 1881 /* 1882 * XXX - need more locking here to protect against 1883 * connect/disconnect races for SMP. 1884 */ 1885 if (unp->unp_addr != NULL) 1886 bcopy(unp->unp_addr, &xu->xu_addr, 1887 unp->unp_addr->sun_len); 1888 else 1889 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1890 if (unp->unp_conn != NULL && 1891 unp->unp_conn->unp_addr != NULL) 1892 bcopy(unp->unp_conn->unp_addr, 1893 &xu->xu_caddr, 1894 unp->unp_conn->unp_addr->sun_len); 1895 else 1896 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1897 xu->unp_vnode = (uintptr_t)unp->unp_vnode; 1898 xu->unp_conn = (uintptr_t)unp->unp_conn; 1899 xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs); 1900 xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink); 1901 xu->unp_gencnt = unp->unp_gencnt; 1902 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1903 UNP_PCB_UNLOCK(unp); 1904 error = SYSCTL_OUT(req, xu, sizeof *xu); 1905 } else { 1906 UNP_PCB_UNLOCK(unp); 1907 } 1908 } 1909 free(xu, M_TEMP); 1910 if (!error) { 1911 /* 1912 * Give the user an updated idea of our state. If the 1913 * generation differs from what we told her before, she knows 1914 * that something happened while we were processing this 1915 * request, and it might be necessary to retry. 1916 */ 1917 xug->xug_gen = unp_gencnt; 1918 xug->xug_sogen = so_gencnt; 1919 xug->xug_count = unp_count; 1920 error = SYSCTL_OUT(req, xug, sizeof *xug); 1921 } 1922 free(unp_list, M_TEMP); 1923 free(xug, M_TEMP); 1924 return (error); 1925 } 1926 1927 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, 1928 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1929 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1930 "List of active local datagram sockets"); 1931 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, 1932 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1933 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1934 "List of active local stream sockets"); 1935 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1936 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1937 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1938 "List of active local seqpacket sockets"); 1939 1940 static void 1941 unp_shutdown(struct unpcb *unp) 1942 { 1943 struct unpcb *unp2; 1944 struct socket *so; 1945 1946 UNP_PCB_LOCK_ASSERT(unp); 1947 1948 unp2 = unp->unp_conn; 1949 if ((unp->unp_socket->so_type == SOCK_STREAM || 1950 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1951 so = unp2->unp_socket; 1952 if (so != NULL) 1953 socantrcvmore(so); 1954 } 1955 } 1956 1957 static void 1958 unp_drop(struct unpcb *unp) 1959 { 1960 struct socket *so; 1961 struct unpcb *unp2; 1962 1963 /* 1964 * Regardless of whether the socket's peer dropped the connection 1965 * with this socket by aborting or disconnecting, POSIX requires 1966 * that ECONNRESET is returned. 1967 */ 1968 1969 UNP_PCB_LOCK(unp); 1970 so = unp->unp_socket; 1971 if (so) 1972 so->so_error = ECONNRESET; 1973 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) { 1974 /* Last reference dropped in unp_disconnect(). */ 1975 unp_pcb_rele_notlast(unp); 1976 unp_disconnect(unp, unp2); 1977 } else if (!unp_pcb_rele(unp)) { 1978 UNP_PCB_UNLOCK(unp); 1979 } 1980 } 1981 1982 static void 1983 unp_freerights(struct filedescent **fdep, int fdcount) 1984 { 1985 struct file *fp; 1986 int i; 1987 1988 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1989 1990 for (i = 0; i < fdcount; i++) { 1991 fp = fdep[i]->fde_file; 1992 filecaps_free(&fdep[i]->fde_caps); 1993 unp_discard(fp); 1994 } 1995 free(fdep[0], M_FILECAPS); 1996 } 1997 1998 static int 1999 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 2000 { 2001 struct thread *td = curthread; /* XXX */ 2002 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2003 int i; 2004 int *fdp; 2005 struct filedesc *fdesc = td->td_proc->p_fd; 2006 struct filedescent **fdep; 2007 void *data; 2008 socklen_t clen = control->m_len, datalen; 2009 int error, newfds; 2010 u_int newlen; 2011 2012 UNP_LINK_UNLOCK_ASSERT(); 2013 2014 error = 0; 2015 if (controlp != NULL) /* controlp == NULL => free control messages */ 2016 *controlp = NULL; 2017 while (cm != NULL) { 2018 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 2019 error = EINVAL; 2020 break; 2021 } 2022 data = CMSG_DATA(cm); 2023 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2024 if (cm->cmsg_level == SOL_SOCKET 2025 && cm->cmsg_type == SCM_RIGHTS) { 2026 newfds = datalen / sizeof(*fdep); 2027 if (newfds == 0) 2028 goto next; 2029 fdep = data; 2030 2031 /* If we're not outputting the descriptors free them. */ 2032 if (error || controlp == NULL) { 2033 unp_freerights(fdep, newfds); 2034 goto next; 2035 } 2036 FILEDESC_XLOCK(fdesc); 2037 2038 /* 2039 * Now change each pointer to an fd in the global 2040 * table to an integer that is the index to the local 2041 * fd table entry that we set up to point to the 2042 * global one we are transferring. 2043 */ 2044 newlen = newfds * sizeof(int); 2045 *controlp = sbcreatecontrol(NULL, newlen, 2046 SCM_RIGHTS, SOL_SOCKET, M_NOWAIT); 2047 if (*controlp == NULL) { 2048 FILEDESC_XUNLOCK(fdesc); 2049 error = E2BIG; 2050 unp_freerights(fdep, newfds); 2051 goto next; 2052 } 2053 2054 fdp = (int *) 2055 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2056 if (fdallocn(td, 0, fdp, newfds) != 0) { 2057 FILEDESC_XUNLOCK(fdesc); 2058 error = EMSGSIZE; 2059 unp_freerights(fdep, newfds); 2060 m_freem(*controlp); 2061 *controlp = NULL; 2062 goto next; 2063 } 2064 for (i = 0; i < newfds; i++, fdp++) { 2065 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2066 (flags & MSG_CMSG_CLOEXEC) != 0 ? O_CLOEXEC : 0, 2067 &fdep[i]->fde_caps); 2068 unp_externalize_fp(fdep[i]->fde_file); 2069 } 2070 2071 /* 2072 * The new type indicates that the mbuf data refers to 2073 * kernel resources that may need to be released before 2074 * the mbuf is freed. 2075 */ 2076 m_chtype(*controlp, MT_EXTCONTROL); 2077 FILEDESC_XUNLOCK(fdesc); 2078 free(fdep[0], M_FILECAPS); 2079 } else { 2080 /* We can just copy anything else across. */ 2081 if (error || controlp == NULL) 2082 goto next; 2083 *controlp = sbcreatecontrol(NULL, datalen, 2084 cm->cmsg_type, cm->cmsg_level, M_NOWAIT); 2085 if (*controlp == NULL) { 2086 error = ENOBUFS; 2087 goto next; 2088 } 2089 bcopy(data, 2090 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2091 datalen); 2092 } 2093 controlp = &(*controlp)->m_next; 2094 2095 next: 2096 if (CMSG_SPACE(datalen) < clen) { 2097 clen -= CMSG_SPACE(datalen); 2098 cm = (struct cmsghdr *) 2099 ((caddr_t)cm + CMSG_SPACE(datalen)); 2100 } else { 2101 clen = 0; 2102 cm = NULL; 2103 } 2104 } 2105 2106 m_freem(control); 2107 return (error); 2108 } 2109 2110 static void 2111 unp_zone_change(void *tag) 2112 { 2113 2114 uma_zone_set_max(unp_zone, maxsockets); 2115 } 2116 2117 #ifdef INVARIANTS 2118 static void 2119 unp_zdtor(void *mem, int size __unused, void *arg __unused) 2120 { 2121 struct unpcb *unp; 2122 2123 unp = mem; 2124 2125 KASSERT(LIST_EMPTY(&unp->unp_refs), 2126 ("%s: unpcb %p has lingering refs", __func__, unp)); 2127 KASSERT(unp->unp_socket == NULL, 2128 ("%s: unpcb %p has socket backpointer", __func__, unp)); 2129 KASSERT(unp->unp_vnode == NULL, 2130 ("%s: unpcb %p has vnode references", __func__, unp)); 2131 KASSERT(unp->unp_conn == NULL, 2132 ("%s: unpcb %p is still connected", __func__, unp)); 2133 KASSERT(unp->unp_addr == NULL, 2134 ("%s: unpcb %p has leaked addr", __func__, unp)); 2135 } 2136 #endif 2137 2138 static void 2139 unp_init(void *arg __unused) 2140 { 2141 uma_dtor dtor; 2142 2143 #ifdef INVARIANTS 2144 dtor = unp_zdtor; 2145 #else 2146 dtor = NULL; 2147 #endif 2148 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, dtor, 2149 NULL, NULL, UMA_ALIGN_CACHE, 0); 2150 uma_zone_set_max(unp_zone, maxsockets); 2151 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2152 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2153 NULL, EVENTHANDLER_PRI_ANY); 2154 LIST_INIT(&unp_dhead); 2155 LIST_INIT(&unp_shead); 2156 LIST_INIT(&unp_sphead); 2157 SLIST_INIT(&unp_defers); 2158 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2159 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2160 UNP_LINK_LOCK_INIT(); 2161 UNP_DEFERRED_LOCK_INIT(); 2162 } 2163 SYSINIT(unp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_SECOND, unp_init, NULL); 2164 2165 static void 2166 unp_internalize_cleanup_rights(struct mbuf *control) 2167 { 2168 struct cmsghdr *cp; 2169 struct mbuf *m; 2170 void *data; 2171 socklen_t datalen; 2172 2173 for (m = control; m != NULL; m = m->m_next) { 2174 cp = mtod(m, struct cmsghdr *); 2175 if (cp->cmsg_level != SOL_SOCKET || 2176 cp->cmsg_type != SCM_RIGHTS) 2177 continue; 2178 data = CMSG_DATA(cp); 2179 datalen = (caddr_t)cp + cp->cmsg_len - (caddr_t)data; 2180 unp_freerights(data, datalen / sizeof(struct filedesc *)); 2181 } 2182 } 2183 2184 static int 2185 unp_internalize(struct mbuf **controlp, struct thread *td) 2186 { 2187 struct mbuf *control, **initial_controlp; 2188 struct proc *p; 2189 struct filedesc *fdesc; 2190 struct bintime *bt; 2191 struct cmsghdr *cm; 2192 struct cmsgcred *cmcred; 2193 struct filedescent *fde, **fdep, *fdev; 2194 struct file *fp; 2195 struct timeval *tv; 2196 struct timespec *ts; 2197 void *data; 2198 socklen_t clen, datalen; 2199 int i, j, error, *fdp, oldfds; 2200 u_int newlen; 2201 2202 UNP_LINK_UNLOCK_ASSERT(); 2203 2204 p = td->td_proc; 2205 fdesc = p->p_fd; 2206 error = 0; 2207 control = *controlp; 2208 clen = control->m_len; 2209 *controlp = NULL; 2210 initial_controlp = controlp; 2211 for (cm = mtod(control, struct cmsghdr *); cm != NULL;) { 2212 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2213 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2214 error = EINVAL; 2215 goto out; 2216 } 2217 data = CMSG_DATA(cm); 2218 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2219 2220 switch (cm->cmsg_type) { 2221 /* 2222 * Fill in credential information. 2223 */ 2224 case SCM_CREDS: 2225 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2226 SCM_CREDS, SOL_SOCKET, M_WAITOK); 2227 cmcred = (struct cmsgcred *) 2228 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2229 cmcred->cmcred_pid = p->p_pid; 2230 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2231 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2232 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2233 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2234 CMGROUP_MAX); 2235 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2236 cmcred->cmcred_groups[i] = 2237 td->td_ucred->cr_groups[i]; 2238 break; 2239 2240 case SCM_RIGHTS: 2241 oldfds = datalen / sizeof (int); 2242 if (oldfds == 0) 2243 break; 2244 /* 2245 * Check that all the FDs passed in refer to legal 2246 * files. If not, reject the entire operation. 2247 */ 2248 fdp = data; 2249 FILEDESC_SLOCK(fdesc); 2250 for (i = 0; i < oldfds; i++, fdp++) { 2251 fp = fget_noref(fdesc, *fdp); 2252 if (fp == NULL) { 2253 FILEDESC_SUNLOCK(fdesc); 2254 error = EBADF; 2255 goto out; 2256 } 2257 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2258 FILEDESC_SUNLOCK(fdesc); 2259 error = EOPNOTSUPP; 2260 goto out; 2261 } 2262 } 2263 2264 /* 2265 * Now replace the integer FDs with pointers to the 2266 * file structure and capability rights. 2267 */ 2268 newlen = oldfds * sizeof(fdep[0]); 2269 *controlp = sbcreatecontrol(NULL, newlen, 2270 SCM_RIGHTS, SOL_SOCKET, M_WAITOK); 2271 fdp = data; 2272 for (i = 0; i < oldfds; i++, fdp++) { 2273 if (!fhold(fdesc->fd_ofiles[*fdp].fde_file)) { 2274 fdp = data; 2275 for (j = 0; j < i; j++, fdp++) { 2276 fdrop(fdesc->fd_ofiles[*fdp]. 2277 fde_file, td); 2278 } 2279 FILEDESC_SUNLOCK(fdesc); 2280 error = EBADF; 2281 goto out; 2282 } 2283 } 2284 fdp = data; 2285 fdep = (struct filedescent **) 2286 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2287 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2288 M_WAITOK); 2289 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2290 fde = &fdesc->fd_ofiles[*fdp]; 2291 fdep[i] = fdev; 2292 fdep[i]->fde_file = fde->fde_file; 2293 filecaps_copy(&fde->fde_caps, 2294 &fdep[i]->fde_caps, true); 2295 unp_internalize_fp(fdep[i]->fde_file); 2296 } 2297 FILEDESC_SUNLOCK(fdesc); 2298 break; 2299 2300 case SCM_TIMESTAMP: 2301 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2302 SCM_TIMESTAMP, SOL_SOCKET, M_WAITOK); 2303 tv = (struct timeval *) 2304 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2305 microtime(tv); 2306 break; 2307 2308 case SCM_BINTIME: 2309 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2310 SCM_BINTIME, SOL_SOCKET, M_WAITOK); 2311 bt = (struct bintime *) 2312 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2313 bintime(bt); 2314 break; 2315 2316 case SCM_REALTIME: 2317 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2318 SCM_REALTIME, SOL_SOCKET, M_WAITOK); 2319 ts = (struct timespec *) 2320 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2321 nanotime(ts); 2322 break; 2323 2324 case SCM_MONOTONIC: 2325 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2326 SCM_MONOTONIC, SOL_SOCKET, M_WAITOK); 2327 ts = (struct timespec *) 2328 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2329 nanouptime(ts); 2330 break; 2331 2332 default: 2333 error = EINVAL; 2334 goto out; 2335 } 2336 2337 if (*controlp != NULL) 2338 controlp = &(*controlp)->m_next; 2339 if (CMSG_SPACE(datalen) < clen) { 2340 clen -= CMSG_SPACE(datalen); 2341 cm = (struct cmsghdr *) 2342 ((caddr_t)cm + CMSG_SPACE(datalen)); 2343 } else { 2344 clen = 0; 2345 cm = NULL; 2346 } 2347 } 2348 2349 out: 2350 if (error != 0 && initial_controlp != NULL) 2351 unp_internalize_cleanup_rights(*initial_controlp); 2352 m_freem(control); 2353 return (error); 2354 } 2355 2356 static struct mbuf * 2357 unp_addsockcred(struct thread *td, struct mbuf *control, int mode) 2358 { 2359 struct mbuf *m, *n, *n_prev; 2360 const struct cmsghdr *cm; 2361 int ngroups, i, cmsgtype; 2362 size_t ctrlsz; 2363 2364 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2365 if (mode & UNP_WANTCRED_ALWAYS) { 2366 ctrlsz = SOCKCRED2SIZE(ngroups); 2367 cmsgtype = SCM_CREDS2; 2368 } else { 2369 ctrlsz = SOCKCREDSIZE(ngroups); 2370 cmsgtype = SCM_CREDS; 2371 } 2372 2373 m = sbcreatecontrol(NULL, ctrlsz, cmsgtype, SOL_SOCKET, M_NOWAIT); 2374 if (m == NULL) 2375 return (control); 2376 2377 if (mode & UNP_WANTCRED_ALWAYS) { 2378 struct sockcred2 *sc; 2379 2380 sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *)); 2381 sc->sc_version = 0; 2382 sc->sc_pid = td->td_proc->p_pid; 2383 sc->sc_uid = td->td_ucred->cr_ruid; 2384 sc->sc_euid = td->td_ucred->cr_uid; 2385 sc->sc_gid = td->td_ucred->cr_rgid; 2386 sc->sc_egid = td->td_ucred->cr_gid; 2387 sc->sc_ngroups = ngroups; 2388 for (i = 0; i < sc->sc_ngroups; i++) 2389 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2390 } else { 2391 struct sockcred *sc; 2392 2393 sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *)); 2394 sc->sc_uid = td->td_ucred->cr_ruid; 2395 sc->sc_euid = td->td_ucred->cr_uid; 2396 sc->sc_gid = td->td_ucred->cr_rgid; 2397 sc->sc_egid = td->td_ucred->cr_gid; 2398 sc->sc_ngroups = ngroups; 2399 for (i = 0; i < sc->sc_ngroups; i++) 2400 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2401 } 2402 2403 /* 2404 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2405 * created SCM_CREDS control message (struct sockcred) has another 2406 * format. 2407 */ 2408 if (control != NULL && cmsgtype == SCM_CREDS) 2409 for (n = control, n_prev = NULL; n != NULL;) { 2410 cm = mtod(n, struct cmsghdr *); 2411 if (cm->cmsg_level == SOL_SOCKET && 2412 cm->cmsg_type == SCM_CREDS) { 2413 if (n_prev == NULL) 2414 control = n->m_next; 2415 else 2416 n_prev->m_next = n->m_next; 2417 n = m_free(n); 2418 } else { 2419 n_prev = n; 2420 n = n->m_next; 2421 } 2422 } 2423 2424 /* Prepend it to the head. */ 2425 m->m_next = control; 2426 return (m); 2427 } 2428 2429 static struct unpcb * 2430 fptounp(struct file *fp) 2431 { 2432 struct socket *so; 2433 2434 if (fp->f_type != DTYPE_SOCKET) 2435 return (NULL); 2436 if ((so = fp->f_data) == NULL) 2437 return (NULL); 2438 if (so->so_proto->pr_domain != &localdomain) 2439 return (NULL); 2440 return sotounpcb(so); 2441 } 2442 2443 static void 2444 unp_discard(struct file *fp) 2445 { 2446 struct unp_defer *dr; 2447 2448 if (unp_externalize_fp(fp)) { 2449 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2450 dr->ud_fp = fp; 2451 UNP_DEFERRED_LOCK(); 2452 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2453 UNP_DEFERRED_UNLOCK(); 2454 atomic_add_int(&unp_defers_count, 1); 2455 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2456 } else 2457 closef_nothread(fp); 2458 } 2459 2460 static void 2461 unp_process_defers(void *arg __unused, int pending) 2462 { 2463 struct unp_defer *dr; 2464 SLIST_HEAD(, unp_defer) drl; 2465 int count; 2466 2467 SLIST_INIT(&drl); 2468 for (;;) { 2469 UNP_DEFERRED_LOCK(); 2470 if (SLIST_FIRST(&unp_defers) == NULL) { 2471 UNP_DEFERRED_UNLOCK(); 2472 break; 2473 } 2474 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2475 UNP_DEFERRED_UNLOCK(); 2476 count = 0; 2477 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2478 SLIST_REMOVE_HEAD(&drl, ud_link); 2479 closef_nothread(dr->ud_fp); 2480 free(dr, M_TEMP); 2481 count++; 2482 } 2483 atomic_add_int(&unp_defers_count, -count); 2484 } 2485 } 2486 2487 static void 2488 unp_internalize_fp(struct file *fp) 2489 { 2490 struct unpcb *unp; 2491 2492 UNP_LINK_WLOCK(); 2493 if ((unp = fptounp(fp)) != NULL) { 2494 unp->unp_file = fp; 2495 unp->unp_msgcount++; 2496 } 2497 unp_rights++; 2498 UNP_LINK_WUNLOCK(); 2499 } 2500 2501 static int 2502 unp_externalize_fp(struct file *fp) 2503 { 2504 struct unpcb *unp; 2505 int ret; 2506 2507 UNP_LINK_WLOCK(); 2508 if ((unp = fptounp(fp)) != NULL) { 2509 unp->unp_msgcount--; 2510 ret = 1; 2511 } else 2512 ret = 0; 2513 unp_rights--; 2514 UNP_LINK_WUNLOCK(); 2515 return (ret); 2516 } 2517 2518 /* 2519 * unp_defer indicates whether additional work has been defered for a future 2520 * pass through unp_gc(). It is thread local and does not require explicit 2521 * synchronization. 2522 */ 2523 static int unp_marked; 2524 2525 static void 2526 unp_remove_dead_ref(struct filedescent **fdep, int fdcount) 2527 { 2528 struct unpcb *unp; 2529 struct file *fp; 2530 int i; 2531 2532 /* 2533 * This function can only be called from the gc task. 2534 */ 2535 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2536 ("%s: not on gc callout", __func__)); 2537 UNP_LINK_LOCK_ASSERT(); 2538 2539 for (i = 0; i < fdcount; i++) { 2540 fp = fdep[i]->fde_file; 2541 if ((unp = fptounp(fp)) == NULL) 2542 continue; 2543 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2544 continue; 2545 unp->unp_gcrefs--; 2546 } 2547 } 2548 2549 static void 2550 unp_restore_undead_ref(struct filedescent **fdep, int fdcount) 2551 { 2552 struct unpcb *unp; 2553 struct file *fp; 2554 int i; 2555 2556 /* 2557 * This function can only be called from the gc task. 2558 */ 2559 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2560 ("%s: not on gc callout", __func__)); 2561 UNP_LINK_LOCK_ASSERT(); 2562 2563 for (i = 0; i < fdcount; i++) { 2564 fp = fdep[i]->fde_file; 2565 if ((unp = fptounp(fp)) == NULL) 2566 continue; 2567 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2568 continue; 2569 unp->unp_gcrefs++; 2570 unp_marked++; 2571 } 2572 } 2573 2574 static void 2575 unp_gc_scan(struct unpcb *unp, void (*op)(struct filedescent **, int)) 2576 { 2577 struct socket *so, *soa; 2578 2579 so = unp->unp_socket; 2580 SOCK_LOCK(so); 2581 if (SOLISTENING(so)) { 2582 /* 2583 * Mark all sockets in our accept queue. 2584 */ 2585 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2586 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2587 continue; 2588 SOCKBUF_LOCK(&soa->so_rcv); 2589 unp_scan(soa->so_rcv.sb_mb, op); 2590 SOCKBUF_UNLOCK(&soa->so_rcv); 2591 } 2592 } else { 2593 /* 2594 * Mark all sockets we reference with RIGHTS. 2595 */ 2596 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2597 SOCKBUF_LOCK(&so->so_rcv); 2598 unp_scan(so->so_rcv.sb_mb, op); 2599 SOCKBUF_UNLOCK(&so->so_rcv); 2600 } 2601 } 2602 SOCK_UNLOCK(so); 2603 } 2604 2605 static int unp_recycled; 2606 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2607 "Number of unreachable sockets claimed by the garbage collector."); 2608 2609 static int unp_taskcount; 2610 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2611 "Number of times the garbage collector has run."); 2612 2613 SYSCTL_UINT(_net_local, OID_AUTO, sockcount, CTLFLAG_RD, &unp_count, 0, 2614 "Number of active local sockets."); 2615 2616 static void 2617 unp_gc(__unused void *arg, int pending) 2618 { 2619 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2620 NULL }; 2621 struct unp_head **head; 2622 struct unp_head unp_deadhead; /* List of potentially-dead sockets. */ 2623 struct file *f, **unref; 2624 struct unpcb *unp, *unptmp; 2625 int i, total, unp_unreachable; 2626 2627 LIST_INIT(&unp_deadhead); 2628 unp_taskcount++; 2629 UNP_LINK_RLOCK(); 2630 /* 2631 * First determine which sockets may be in cycles. 2632 */ 2633 unp_unreachable = 0; 2634 2635 for (head = heads; *head != NULL; head++) 2636 LIST_FOREACH(unp, *head, unp_link) { 2637 KASSERT((unp->unp_gcflag & ~UNPGC_IGNORE_RIGHTS) == 0, 2638 ("%s: unp %p has unexpected gc flags 0x%x", 2639 __func__, unp, (unsigned int)unp->unp_gcflag)); 2640 2641 f = unp->unp_file; 2642 2643 /* 2644 * Check for an unreachable socket potentially in a 2645 * cycle. It must be in a queue as indicated by 2646 * msgcount, and this must equal the file reference 2647 * count. Note that when msgcount is 0 the file is 2648 * NULL. 2649 */ 2650 if (f != NULL && unp->unp_msgcount != 0 && 2651 refcount_load(&f->f_count) == unp->unp_msgcount) { 2652 LIST_INSERT_HEAD(&unp_deadhead, unp, unp_dead); 2653 unp->unp_gcflag |= UNPGC_DEAD; 2654 unp->unp_gcrefs = unp->unp_msgcount; 2655 unp_unreachable++; 2656 } 2657 } 2658 2659 /* 2660 * Scan all sockets previously marked as potentially being in a cycle 2661 * and remove the references each socket holds on any UNPGC_DEAD 2662 * sockets in its queue. After this step, all remaining references on 2663 * sockets marked UNPGC_DEAD should not be part of any cycle. 2664 */ 2665 LIST_FOREACH(unp, &unp_deadhead, unp_dead) 2666 unp_gc_scan(unp, unp_remove_dead_ref); 2667 2668 /* 2669 * If a socket still has a non-negative refcount, it cannot be in a 2670 * cycle. In this case increment refcount of all children iteratively. 2671 * Stop the scan once we do a complete loop without discovering 2672 * a new reachable socket. 2673 */ 2674 do { 2675 unp_marked = 0; 2676 LIST_FOREACH_SAFE(unp, &unp_deadhead, unp_dead, unptmp) 2677 if (unp->unp_gcrefs > 0) { 2678 unp->unp_gcflag &= ~UNPGC_DEAD; 2679 LIST_REMOVE(unp, unp_dead); 2680 KASSERT(unp_unreachable > 0, 2681 ("%s: unp_unreachable underflow.", 2682 __func__)); 2683 unp_unreachable--; 2684 unp_gc_scan(unp, unp_restore_undead_ref); 2685 } 2686 } while (unp_marked); 2687 2688 UNP_LINK_RUNLOCK(); 2689 2690 if (unp_unreachable == 0) 2691 return; 2692 2693 /* 2694 * Allocate space for a local array of dead unpcbs. 2695 * TODO: can this path be simplified by instead using the local 2696 * dead list at unp_deadhead, after taking out references 2697 * on the file object and/or unpcb and dropping the link lock? 2698 */ 2699 unref = malloc(unp_unreachable * sizeof(struct file *), 2700 M_TEMP, M_WAITOK); 2701 2702 /* 2703 * Iterate looking for sockets which have been specifically marked 2704 * as unreachable and store them locally. 2705 */ 2706 UNP_LINK_RLOCK(); 2707 total = 0; 2708 LIST_FOREACH(unp, &unp_deadhead, unp_dead) { 2709 KASSERT((unp->unp_gcflag & UNPGC_DEAD) != 0, 2710 ("%s: unp %p not marked UNPGC_DEAD", __func__, unp)); 2711 unp->unp_gcflag &= ~UNPGC_DEAD; 2712 f = unp->unp_file; 2713 if (unp->unp_msgcount == 0 || f == NULL || 2714 refcount_load(&f->f_count) != unp->unp_msgcount || 2715 !fhold(f)) 2716 continue; 2717 unref[total++] = f; 2718 KASSERT(total <= unp_unreachable, 2719 ("%s: incorrect unreachable count.", __func__)); 2720 } 2721 UNP_LINK_RUNLOCK(); 2722 2723 /* 2724 * Now flush all sockets, free'ing rights. This will free the 2725 * struct files associated with these sockets but leave each socket 2726 * with one remaining ref. 2727 */ 2728 for (i = 0; i < total; i++) { 2729 struct socket *so; 2730 2731 so = unref[i]->f_data; 2732 CURVNET_SET(so->so_vnet); 2733 sorflush(so); 2734 CURVNET_RESTORE(); 2735 } 2736 2737 /* 2738 * And finally release the sockets so they can be reclaimed. 2739 */ 2740 for (i = 0; i < total; i++) 2741 fdrop(unref[i], NULL); 2742 unp_recycled += total; 2743 free(unref, M_TEMP); 2744 } 2745 2746 /* 2747 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2748 */ 2749 static void 2750 unp_dispose(struct socket *so) 2751 { 2752 struct sockbuf *sb = &so->so_rcv; 2753 struct unpcb *unp; 2754 struct mbuf *m; 2755 2756 MPASS(!SOLISTENING(so)); 2757 2758 unp = sotounpcb(so); 2759 UNP_LINK_WLOCK(); 2760 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2761 UNP_LINK_WUNLOCK(); 2762 2763 /* 2764 * Grab our special mbufs before calling sbrelease(). 2765 */ 2766 SOCK_RECVBUF_LOCK(so); 2767 m = sbcut_locked(sb, sb->sb_ccc); 2768 KASSERT(sb->sb_ccc == 0 && sb->sb_mb == 0 && sb->sb_mbcnt == 0, 2769 ("%s: ccc %u mb %p mbcnt %u", __func__, 2770 sb->sb_ccc, (void *)sb->sb_mb, sb->sb_mbcnt)); 2771 sbrelease_locked(so, SO_RCV); 2772 SOCK_RECVBUF_UNLOCK(so); 2773 if (SOCK_IO_RECV_OWNED(so)) 2774 SOCK_IO_RECV_UNLOCK(so); 2775 2776 if (m != NULL) { 2777 unp_scan(m, unp_freerights); 2778 m_freem(m); 2779 } 2780 } 2781 2782 static void 2783 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2784 { 2785 struct mbuf *m; 2786 struct cmsghdr *cm; 2787 void *data; 2788 socklen_t clen, datalen; 2789 2790 while (m0 != NULL) { 2791 for (m = m0; m; m = m->m_next) { 2792 if (m->m_type != MT_CONTROL) 2793 continue; 2794 2795 cm = mtod(m, struct cmsghdr *); 2796 clen = m->m_len; 2797 2798 while (cm != NULL) { 2799 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2800 break; 2801 2802 data = CMSG_DATA(cm); 2803 datalen = (caddr_t)cm + cm->cmsg_len 2804 - (caddr_t)data; 2805 2806 if (cm->cmsg_level == SOL_SOCKET && 2807 cm->cmsg_type == SCM_RIGHTS) { 2808 (*op)(data, datalen / 2809 sizeof(struct filedescent *)); 2810 } 2811 2812 if (CMSG_SPACE(datalen) < clen) { 2813 clen -= CMSG_SPACE(datalen); 2814 cm = (struct cmsghdr *) 2815 ((caddr_t)cm + CMSG_SPACE(datalen)); 2816 } else { 2817 clen = 0; 2818 cm = NULL; 2819 } 2820 } 2821 } 2822 m0 = m0->m_nextpkt; 2823 } 2824 } 2825 2826 /* 2827 * A helper function called by VFS before socket-type vnode reclamation. 2828 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2829 * use count. 2830 */ 2831 void 2832 vfs_unp_reclaim(struct vnode *vp) 2833 { 2834 struct unpcb *unp; 2835 int active; 2836 struct mtx *vplock; 2837 2838 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2839 KASSERT(vp->v_type == VSOCK, 2840 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2841 2842 active = 0; 2843 vplock = mtx_pool_find(mtxpool_sleep, vp); 2844 mtx_lock(vplock); 2845 VOP_UNP_CONNECT(vp, &unp); 2846 if (unp == NULL) 2847 goto done; 2848 UNP_PCB_LOCK(unp); 2849 if (unp->unp_vnode == vp) { 2850 VOP_UNP_DETACH(vp); 2851 unp->unp_vnode = NULL; 2852 active = 1; 2853 } 2854 UNP_PCB_UNLOCK(unp); 2855 done: 2856 mtx_unlock(vplock); 2857 if (active) 2858 vunref(vp); 2859 } 2860 2861 #ifdef DDB 2862 static void 2863 db_print_indent(int indent) 2864 { 2865 int i; 2866 2867 for (i = 0; i < indent; i++) 2868 db_printf(" "); 2869 } 2870 2871 static void 2872 db_print_unpflags(int unp_flags) 2873 { 2874 int comma; 2875 2876 comma = 0; 2877 if (unp_flags & UNP_HAVEPC) { 2878 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2879 comma = 1; 2880 } 2881 if (unp_flags & UNP_WANTCRED_ALWAYS) { 2882 db_printf("%sUNP_WANTCRED_ALWAYS", comma ? ", " : ""); 2883 comma = 1; 2884 } 2885 if (unp_flags & UNP_WANTCRED_ONESHOT) { 2886 db_printf("%sUNP_WANTCRED_ONESHOT", comma ? ", " : ""); 2887 comma = 1; 2888 } 2889 if (unp_flags & UNP_CONNWAIT) { 2890 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2891 comma = 1; 2892 } 2893 if (unp_flags & UNP_CONNECTING) { 2894 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2895 comma = 1; 2896 } 2897 if (unp_flags & UNP_BINDING) { 2898 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2899 comma = 1; 2900 } 2901 } 2902 2903 static void 2904 db_print_xucred(int indent, struct xucred *xu) 2905 { 2906 int comma, i; 2907 2908 db_print_indent(indent); 2909 db_printf("cr_version: %u cr_uid: %u cr_pid: %d cr_ngroups: %d\n", 2910 xu->cr_version, xu->cr_uid, xu->cr_pid, xu->cr_ngroups); 2911 db_print_indent(indent); 2912 db_printf("cr_groups: "); 2913 comma = 0; 2914 for (i = 0; i < xu->cr_ngroups; i++) { 2915 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2916 comma = 1; 2917 } 2918 db_printf("\n"); 2919 } 2920 2921 static void 2922 db_print_unprefs(int indent, struct unp_head *uh) 2923 { 2924 struct unpcb *unp; 2925 int counter; 2926 2927 counter = 0; 2928 LIST_FOREACH(unp, uh, unp_reflink) { 2929 if (counter % 4 == 0) 2930 db_print_indent(indent); 2931 db_printf("%p ", unp); 2932 if (counter % 4 == 3) 2933 db_printf("\n"); 2934 counter++; 2935 } 2936 if (counter != 0 && counter % 4 != 0) 2937 db_printf("\n"); 2938 } 2939 2940 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2941 { 2942 struct unpcb *unp; 2943 2944 if (!have_addr) { 2945 db_printf("usage: show unpcb <addr>\n"); 2946 return; 2947 } 2948 unp = (struct unpcb *)addr; 2949 2950 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2951 unp->unp_vnode); 2952 2953 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2954 unp->unp_conn); 2955 2956 db_printf("unp_refs:\n"); 2957 db_print_unprefs(2, &unp->unp_refs); 2958 2959 /* XXXRW: Would be nice to print the full address, if any. */ 2960 db_printf("unp_addr: %p\n", unp->unp_addr); 2961 2962 db_printf("unp_gencnt: %llu\n", 2963 (unsigned long long)unp->unp_gencnt); 2964 2965 db_printf("unp_flags: %x (", unp->unp_flags); 2966 db_print_unpflags(unp->unp_flags); 2967 db_printf(")\n"); 2968 2969 db_printf("unp_peercred:\n"); 2970 db_print_xucred(2, &unp->unp_peercred); 2971 2972 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2973 } 2974 #endif 2975