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