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