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 *, int); 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 (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_one(&rights, CAP_BINDAT), 640 td); 641 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 642 error = namei(&nd); 643 if (error) 644 goto error; 645 vp = nd.ni_vp; 646 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 647 NDFREE(&nd, NDF_ONLY_PNBUF); 648 if (nd.ni_dvp == vp) 649 vrele(nd.ni_dvp); 650 else 651 vput(nd.ni_dvp); 652 if (vp != NULL) { 653 vrele(vp); 654 error = EADDRINUSE; 655 goto error; 656 } 657 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 658 if (error) 659 goto error; 660 goto restart; 661 } 662 VATTR_NULL(&vattr); 663 vattr.va_type = VSOCK; 664 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_pd->pd_cmask); 665 #ifdef MAC 666 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 667 &vattr); 668 #endif 669 if (error == 0) 670 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 671 NDFREE(&nd, NDF_ONLY_PNBUF); 672 vput(nd.ni_dvp); 673 if (error) { 674 vn_finished_write(mp); 675 if (error == ERELOOKUP) 676 goto restart; 677 goto error; 678 } 679 vp = nd.ni_vp; 680 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 681 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 682 683 UNP_PCB_LOCK(unp); 684 VOP_UNP_BIND(vp, unp); 685 unp->unp_vnode = vp; 686 unp->unp_addr = soun; 687 unp->unp_flags &= ~UNP_BINDING; 688 UNP_PCB_UNLOCK(unp); 689 VOP_UNLOCK(vp); 690 vn_finished_write(mp); 691 free(buf, M_TEMP); 692 return (0); 693 694 error: 695 UNP_PCB_LOCK(unp); 696 unp->unp_flags &= ~UNP_BINDING; 697 UNP_PCB_UNLOCK(unp); 698 free(buf, M_TEMP); 699 return (error); 700 } 701 702 static int 703 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 704 { 705 706 return (uipc_bindat(AT_FDCWD, so, nam, td)); 707 } 708 709 static int 710 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 711 { 712 int error; 713 714 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 715 error = unp_connect(so, nam, td); 716 return (error); 717 } 718 719 static int 720 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 721 struct thread *td) 722 { 723 int error; 724 725 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 726 error = unp_connectat(fd, so, nam, td); 727 return (error); 728 } 729 730 static void 731 uipc_close(struct socket *so) 732 { 733 struct unpcb *unp, *unp2; 734 struct vnode *vp = NULL; 735 struct mtx *vplock; 736 737 unp = sotounpcb(so); 738 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 739 740 vplock = NULL; 741 if ((vp = unp->unp_vnode) != NULL) { 742 vplock = mtx_pool_find(mtxpool_sleep, vp); 743 mtx_lock(vplock); 744 } 745 UNP_PCB_LOCK(unp); 746 if (vp && unp->unp_vnode == NULL) { 747 mtx_unlock(vplock); 748 vp = NULL; 749 } 750 if (vp != NULL) { 751 VOP_UNP_DETACH(vp); 752 unp->unp_vnode = NULL; 753 } 754 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 755 unp_disconnect(unp, unp2); 756 else 757 UNP_PCB_UNLOCK(unp); 758 if (vp) { 759 mtx_unlock(vplock); 760 vrele(vp); 761 } 762 } 763 764 static int 765 uipc_connect2(struct socket *so1, struct socket *so2) 766 { 767 struct unpcb *unp, *unp2; 768 int error; 769 770 unp = so1->so_pcb; 771 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 772 unp2 = so2->so_pcb; 773 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 774 unp_pcb_lock_pair(unp, unp2); 775 error = unp_connect2(so1, so2, PRU_CONNECT2); 776 unp_pcb_unlock_pair(unp, unp2); 777 return (error); 778 } 779 780 static void 781 uipc_detach(struct socket *so) 782 { 783 struct unpcb *unp, *unp2; 784 struct mtx *vplock; 785 struct vnode *vp; 786 int local_unp_rights; 787 788 unp = sotounpcb(so); 789 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 790 791 vp = NULL; 792 vplock = NULL; 793 794 SOCK_LOCK(so); 795 if (!SOLISTENING(so)) { 796 /* 797 * Once the socket is removed from the global lists, 798 * uipc_ready() will not be able to locate its socket buffer, so 799 * clear the buffer now. At this point internalized rights have 800 * already been disposed of. 801 */ 802 sbrelease(&so->so_rcv, so); 803 } 804 SOCK_UNLOCK(so); 805 806 UNP_LINK_WLOCK(); 807 LIST_REMOVE(unp, unp_link); 808 if (unp->unp_gcflag & UNPGC_DEAD) 809 LIST_REMOVE(unp, unp_dead); 810 unp->unp_gencnt = ++unp_gencnt; 811 --unp_count; 812 UNP_LINK_WUNLOCK(); 813 814 UNP_PCB_UNLOCK_ASSERT(unp); 815 restart: 816 if ((vp = unp->unp_vnode) != NULL) { 817 vplock = mtx_pool_find(mtxpool_sleep, vp); 818 mtx_lock(vplock); 819 } 820 UNP_PCB_LOCK(unp); 821 if (unp->unp_vnode != vp && unp->unp_vnode != NULL) { 822 if (vplock) 823 mtx_unlock(vplock); 824 UNP_PCB_UNLOCK(unp); 825 goto restart; 826 } 827 if ((vp = unp->unp_vnode) != NULL) { 828 VOP_UNP_DETACH(vp); 829 unp->unp_vnode = NULL; 830 } 831 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 832 unp_disconnect(unp, unp2); 833 else 834 UNP_PCB_UNLOCK(unp); 835 836 UNP_REF_LIST_LOCK(); 837 while (!LIST_EMPTY(&unp->unp_refs)) { 838 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 839 840 unp_pcb_hold(ref); 841 UNP_REF_LIST_UNLOCK(); 842 843 MPASS(ref != unp); 844 UNP_PCB_UNLOCK_ASSERT(ref); 845 unp_drop(ref); 846 UNP_REF_LIST_LOCK(); 847 } 848 UNP_REF_LIST_UNLOCK(); 849 850 UNP_PCB_LOCK(unp); 851 local_unp_rights = unp_rights; 852 unp->unp_socket->so_pcb = NULL; 853 unp->unp_socket = NULL; 854 free(unp->unp_addr, M_SONAME); 855 unp->unp_addr = NULL; 856 if (!unp_pcb_rele(unp)) 857 UNP_PCB_UNLOCK(unp); 858 if (vp) { 859 mtx_unlock(vplock); 860 vrele(vp); 861 } 862 if (local_unp_rights) 863 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 864 } 865 866 static int 867 uipc_disconnect(struct socket *so) 868 { 869 struct unpcb *unp, *unp2; 870 871 unp = sotounpcb(so); 872 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 873 874 UNP_PCB_LOCK(unp); 875 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 876 unp_disconnect(unp, unp2); 877 else 878 UNP_PCB_UNLOCK(unp); 879 return (0); 880 } 881 882 static int 883 uipc_listen(struct socket *so, int backlog, struct thread *td) 884 { 885 struct unpcb *unp; 886 int error; 887 888 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 889 return (EOPNOTSUPP); 890 891 unp = sotounpcb(so); 892 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 893 894 UNP_PCB_LOCK(unp); 895 if (unp->unp_vnode == NULL) { 896 /* Already connected or not bound to an address. */ 897 error = unp->unp_conn != NULL ? EINVAL : EDESTADDRREQ; 898 UNP_PCB_UNLOCK(unp); 899 return (error); 900 } 901 902 SOCK_LOCK(so); 903 error = solisten_proto_check(so); 904 if (error == 0) { 905 cru2xt(td, &unp->unp_peercred); 906 solisten_proto(so, backlog); 907 } 908 SOCK_UNLOCK(so); 909 UNP_PCB_UNLOCK(unp); 910 return (error); 911 } 912 913 static int 914 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 915 { 916 struct unpcb *unp, *unp2; 917 const struct sockaddr *sa; 918 919 unp = sotounpcb(so); 920 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 921 922 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 923 UNP_LINK_RLOCK(); 924 /* 925 * XXX: It seems that this test always fails even when connection is 926 * established. So, this else clause is added as workaround to 927 * return PF_LOCAL sockaddr. 928 */ 929 unp2 = unp->unp_conn; 930 if (unp2 != NULL) { 931 UNP_PCB_LOCK(unp2); 932 if (unp2->unp_addr != NULL) 933 sa = (struct sockaddr *) unp2->unp_addr; 934 else 935 sa = &sun_noname; 936 bcopy(sa, *nam, sa->sa_len); 937 UNP_PCB_UNLOCK(unp2); 938 } else { 939 sa = &sun_noname; 940 bcopy(sa, *nam, sa->sa_len); 941 } 942 UNP_LINK_RUNLOCK(); 943 return (0); 944 } 945 946 static int 947 uipc_rcvd(struct socket *so, int flags) 948 { 949 struct unpcb *unp, *unp2; 950 struct socket *so2; 951 u_int mbcnt, sbcc; 952 953 unp = sotounpcb(so); 954 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 955 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 956 ("%s: socktype %d", __func__, so->so_type)); 957 958 /* 959 * Adjust backpressure on sender and wakeup any waiting to write. 960 * 961 * The unp lock is acquired to maintain the validity of the unp_conn 962 * pointer; no lock on unp2 is required as unp2->unp_socket will be 963 * static as long as we don't permit unp2 to disconnect from unp, 964 * which is prevented by the lock on unp. We cache values from 965 * so_rcv to avoid holding the so_rcv lock over the entire 966 * transaction on the remote so_snd. 967 */ 968 SOCKBUF_LOCK(&so->so_rcv); 969 mbcnt = so->so_rcv.sb_mbcnt; 970 sbcc = sbavail(&so->so_rcv); 971 SOCKBUF_UNLOCK(&so->so_rcv); 972 /* 973 * There is a benign race condition at this point. If we're planning to 974 * clear SB_STOP, but uipc_send is called on the connected socket at 975 * this instant, it might add data to the sockbuf and set SB_STOP. Then 976 * we would erroneously clear SB_STOP below, even though the sockbuf is 977 * full. The race is benign because the only ill effect is to allow the 978 * sockbuf to exceed its size limit, and the size limits are not 979 * strictly guaranteed anyway. 980 */ 981 UNP_PCB_LOCK(unp); 982 unp2 = unp->unp_conn; 983 if (unp2 == NULL) { 984 UNP_PCB_UNLOCK(unp); 985 return (0); 986 } 987 so2 = unp2->unp_socket; 988 SOCKBUF_LOCK(&so2->so_snd); 989 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 990 so2->so_snd.sb_flags &= ~SB_STOP; 991 sowwakeup_locked(so2); 992 UNP_PCB_UNLOCK(unp); 993 return (0); 994 } 995 996 static int 997 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 998 struct mbuf *control, struct thread *td) 999 { 1000 struct unpcb *unp, *unp2; 1001 struct socket *so2; 1002 u_int mbcnt, sbcc; 1003 int freed, error; 1004 1005 unp = sotounpcb(so); 1006 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 1007 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 1008 so->so_type == SOCK_SEQPACKET, 1009 ("%s: socktype %d", __func__, so->so_type)); 1010 1011 freed = error = 0; 1012 if (flags & PRUS_OOB) { 1013 error = EOPNOTSUPP; 1014 goto release; 1015 } 1016 if (control != NULL && (error = unp_internalize(&control, td))) 1017 goto release; 1018 1019 unp2 = NULL; 1020 switch (so->so_type) { 1021 case SOCK_DGRAM: 1022 { 1023 const struct sockaddr *from; 1024 1025 if (nam != NULL) { 1026 error = unp_connect(so, nam, td); 1027 if (error != 0) 1028 break; 1029 } 1030 UNP_PCB_LOCK(unp); 1031 1032 /* 1033 * Because connect() and send() are non-atomic in a sendto() 1034 * with a target address, it's possible that the socket will 1035 * have disconnected before the send() can run. In that case 1036 * return the slightly counter-intuitive but otherwise 1037 * correct error that the socket is not connected. 1038 */ 1039 unp2 = unp_pcb_lock_peer(unp); 1040 if (unp2 == NULL) { 1041 UNP_PCB_UNLOCK(unp); 1042 error = ENOTCONN; 1043 break; 1044 } 1045 1046 if (unp2->unp_flags & UNP_WANTCRED_MASK) 1047 control = unp_addsockcred(td, control, 1048 unp2->unp_flags); 1049 if (unp->unp_addr != NULL) 1050 from = (struct sockaddr *)unp->unp_addr; 1051 else 1052 from = &sun_noname; 1053 so2 = unp2->unp_socket; 1054 SOCKBUF_LOCK(&so2->so_rcv); 1055 if (sbappendaddr_locked(&so2->so_rcv, from, m, 1056 control)) { 1057 sorwakeup_locked(so2); 1058 m = NULL; 1059 control = NULL; 1060 } else { 1061 SOCKBUF_UNLOCK(&so2->so_rcv); 1062 error = ENOBUFS; 1063 } 1064 if (nam != NULL) 1065 unp_disconnect(unp, unp2); 1066 else 1067 unp_pcb_unlock_pair(unp, unp2); 1068 break; 1069 } 1070 1071 case SOCK_SEQPACKET: 1072 case SOCK_STREAM: 1073 if ((so->so_state & SS_ISCONNECTED) == 0) { 1074 if (nam != NULL) { 1075 error = unp_connect(so, nam, td); 1076 if (error != 0) 1077 break; 1078 } else { 1079 error = ENOTCONN; 1080 break; 1081 } 1082 } 1083 1084 UNP_PCB_LOCK(unp); 1085 if ((unp2 = unp_pcb_lock_peer(unp)) == NULL) { 1086 UNP_PCB_UNLOCK(unp); 1087 error = ENOTCONN; 1088 break; 1089 } else if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 1090 unp_pcb_unlock_pair(unp, unp2); 1091 error = EPIPE; 1092 break; 1093 } 1094 UNP_PCB_UNLOCK(unp); 1095 if ((so2 = unp2->unp_socket) == NULL) { 1096 UNP_PCB_UNLOCK(unp2); 1097 error = ENOTCONN; 1098 break; 1099 } 1100 SOCKBUF_LOCK(&so2->so_rcv); 1101 if (unp2->unp_flags & UNP_WANTCRED_MASK) { 1102 /* 1103 * Credentials are passed only once on SOCK_STREAM and 1104 * SOCK_SEQPACKET (LOCAL_CREDS => WANTCRED_ONESHOT), or 1105 * forever (LOCAL_CREDS_PERSISTENT => WANTCRED_ALWAYS). 1106 */ 1107 control = unp_addsockcred(td, control, unp2->unp_flags); 1108 unp2->unp_flags &= ~UNP_WANTCRED_ONESHOT; 1109 } 1110 1111 /* 1112 * Send to paired receive port and wake up readers. Don't 1113 * check for space available in the receive buffer if we're 1114 * attaching ancillary data; Unix domain sockets only check 1115 * for space in the sending sockbuf, and that check is 1116 * performed one level up the stack. At that level we cannot 1117 * precisely account for the amount of buffer space used 1118 * (e.g., because control messages are not yet internalized). 1119 */ 1120 switch (so->so_type) { 1121 case SOCK_STREAM: 1122 if (control != NULL) { 1123 sbappendcontrol_locked(&so2->so_rcv, m, 1124 control, flags); 1125 control = NULL; 1126 } else 1127 sbappend_locked(&so2->so_rcv, m, flags); 1128 break; 1129 1130 case SOCK_SEQPACKET: 1131 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 1132 &sun_noname, m, control)) 1133 control = NULL; 1134 break; 1135 } 1136 1137 mbcnt = so2->so_rcv.sb_mbcnt; 1138 sbcc = sbavail(&so2->so_rcv); 1139 if (sbcc) 1140 sorwakeup_locked(so2); 1141 else 1142 SOCKBUF_UNLOCK(&so2->so_rcv); 1143 1144 /* 1145 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1146 * it would be possible for uipc_rcvd to be called at this 1147 * point, drain the receiving sockbuf, clear SB_STOP, and then 1148 * we would set SB_STOP below. That could lead to an empty 1149 * sockbuf having SB_STOP set 1150 */ 1151 SOCKBUF_LOCK(&so->so_snd); 1152 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1153 so->so_snd.sb_flags |= SB_STOP; 1154 SOCKBUF_UNLOCK(&so->so_snd); 1155 UNP_PCB_UNLOCK(unp2); 1156 m = NULL; 1157 break; 1158 } 1159 1160 /* 1161 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1162 */ 1163 if (flags & PRUS_EOF) { 1164 UNP_PCB_LOCK(unp); 1165 socantsendmore(so); 1166 unp_shutdown(unp); 1167 UNP_PCB_UNLOCK(unp); 1168 } 1169 if (control != NULL && error != 0) 1170 unp_dispose_mbuf(control); 1171 1172 release: 1173 if (control != NULL) 1174 m_freem(control); 1175 /* 1176 * In case of PRUS_NOTREADY, uipc_ready() is responsible 1177 * for freeing memory. 1178 */ 1179 if (m != NULL && (flags & PRUS_NOTREADY) == 0) 1180 m_freem(m); 1181 return (error); 1182 } 1183 1184 static bool 1185 uipc_ready_scan(struct socket *so, struct mbuf *m, int count, int *errorp) 1186 { 1187 struct mbuf *mb, *n; 1188 struct sockbuf *sb; 1189 1190 SOCK_LOCK(so); 1191 if (SOLISTENING(so)) { 1192 SOCK_UNLOCK(so); 1193 return (false); 1194 } 1195 mb = NULL; 1196 sb = &so->so_rcv; 1197 SOCKBUF_LOCK(sb); 1198 if (sb->sb_fnrdy != NULL) { 1199 for (mb = sb->sb_mb, n = mb->m_nextpkt; mb != NULL;) { 1200 if (mb == m) { 1201 *errorp = sbready(sb, m, count); 1202 break; 1203 } 1204 mb = mb->m_next; 1205 if (mb == NULL) { 1206 mb = n; 1207 if (mb != NULL) 1208 n = mb->m_nextpkt; 1209 } 1210 } 1211 } 1212 SOCKBUF_UNLOCK(sb); 1213 SOCK_UNLOCK(so); 1214 return (mb != NULL); 1215 } 1216 1217 static int 1218 uipc_ready(struct socket *so, struct mbuf *m, int count) 1219 { 1220 struct unpcb *unp, *unp2; 1221 struct socket *so2; 1222 int error, i; 1223 1224 unp = sotounpcb(so); 1225 1226 KASSERT(so->so_type == SOCK_STREAM, 1227 ("%s: unexpected socket type for %p", __func__, so)); 1228 1229 UNP_PCB_LOCK(unp); 1230 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) { 1231 UNP_PCB_UNLOCK(unp); 1232 so2 = unp2->unp_socket; 1233 SOCKBUF_LOCK(&so2->so_rcv); 1234 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1235 sorwakeup_locked(so2); 1236 else 1237 SOCKBUF_UNLOCK(&so2->so_rcv); 1238 UNP_PCB_UNLOCK(unp2); 1239 return (error); 1240 } 1241 UNP_PCB_UNLOCK(unp); 1242 1243 /* 1244 * The receiving socket has been disconnected, but may still be valid. 1245 * In this case, the now-ready mbufs are still present in its socket 1246 * buffer, so perform an exhaustive search before giving up and freeing 1247 * the mbufs. 1248 */ 1249 UNP_LINK_RLOCK(); 1250 LIST_FOREACH(unp, &unp_shead, unp_link) { 1251 if (uipc_ready_scan(unp->unp_socket, m, count, &error)) 1252 break; 1253 } 1254 UNP_LINK_RUNLOCK(); 1255 1256 if (unp == NULL) { 1257 for (i = 0; i < count; i++) 1258 m = m_free(m); 1259 error = ECONNRESET; 1260 } 1261 return (error); 1262 } 1263 1264 static int 1265 uipc_sense(struct socket *so, struct stat *sb) 1266 { 1267 struct unpcb *unp; 1268 1269 unp = sotounpcb(so); 1270 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1271 1272 sb->st_blksize = so->so_snd.sb_hiwat; 1273 sb->st_dev = NODEV; 1274 sb->st_ino = unp->unp_ino; 1275 return (0); 1276 } 1277 1278 static int 1279 uipc_shutdown(struct socket *so) 1280 { 1281 struct unpcb *unp; 1282 1283 unp = sotounpcb(so); 1284 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1285 1286 UNP_PCB_LOCK(unp); 1287 socantsendmore(so); 1288 unp_shutdown(unp); 1289 UNP_PCB_UNLOCK(unp); 1290 return (0); 1291 } 1292 1293 static int 1294 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1295 { 1296 struct unpcb *unp; 1297 const struct sockaddr *sa; 1298 1299 unp = sotounpcb(so); 1300 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1301 1302 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1303 UNP_PCB_LOCK(unp); 1304 if (unp->unp_addr != NULL) 1305 sa = (struct sockaddr *) unp->unp_addr; 1306 else 1307 sa = &sun_noname; 1308 bcopy(sa, *nam, sa->sa_len); 1309 UNP_PCB_UNLOCK(unp); 1310 return (0); 1311 } 1312 1313 static struct pr_usrreqs uipc_usrreqs_dgram = { 1314 .pru_abort = uipc_abort, 1315 .pru_accept = uipc_accept, 1316 .pru_attach = uipc_attach, 1317 .pru_bind = uipc_bind, 1318 .pru_bindat = uipc_bindat, 1319 .pru_connect = uipc_connect, 1320 .pru_connectat = uipc_connectat, 1321 .pru_connect2 = uipc_connect2, 1322 .pru_detach = uipc_detach, 1323 .pru_disconnect = uipc_disconnect, 1324 .pru_listen = uipc_listen, 1325 .pru_peeraddr = uipc_peeraddr, 1326 .pru_rcvd = uipc_rcvd, 1327 .pru_send = uipc_send, 1328 .pru_sense = uipc_sense, 1329 .pru_shutdown = uipc_shutdown, 1330 .pru_sockaddr = uipc_sockaddr, 1331 .pru_soreceive = soreceive_dgram, 1332 .pru_close = uipc_close, 1333 }; 1334 1335 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1336 .pru_abort = uipc_abort, 1337 .pru_accept = uipc_accept, 1338 .pru_attach = uipc_attach, 1339 .pru_bind = uipc_bind, 1340 .pru_bindat = uipc_bindat, 1341 .pru_connect = uipc_connect, 1342 .pru_connectat = uipc_connectat, 1343 .pru_connect2 = uipc_connect2, 1344 .pru_detach = uipc_detach, 1345 .pru_disconnect = uipc_disconnect, 1346 .pru_listen = uipc_listen, 1347 .pru_peeraddr = uipc_peeraddr, 1348 .pru_rcvd = uipc_rcvd, 1349 .pru_send = uipc_send, 1350 .pru_sense = uipc_sense, 1351 .pru_shutdown = uipc_shutdown, 1352 .pru_sockaddr = uipc_sockaddr, 1353 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1354 .pru_close = uipc_close, 1355 }; 1356 1357 static struct pr_usrreqs uipc_usrreqs_stream = { 1358 .pru_abort = uipc_abort, 1359 .pru_accept = uipc_accept, 1360 .pru_attach = uipc_attach, 1361 .pru_bind = uipc_bind, 1362 .pru_bindat = uipc_bindat, 1363 .pru_connect = uipc_connect, 1364 .pru_connectat = uipc_connectat, 1365 .pru_connect2 = uipc_connect2, 1366 .pru_detach = uipc_detach, 1367 .pru_disconnect = uipc_disconnect, 1368 .pru_listen = uipc_listen, 1369 .pru_peeraddr = uipc_peeraddr, 1370 .pru_rcvd = uipc_rcvd, 1371 .pru_send = uipc_send, 1372 .pru_ready = uipc_ready, 1373 .pru_sense = uipc_sense, 1374 .pru_shutdown = uipc_shutdown, 1375 .pru_sockaddr = uipc_sockaddr, 1376 .pru_soreceive = soreceive_generic, 1377 .pru_close = uipc_close, 1378 }; 1379 1380 static int 1381 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1382 { 1383 struct unpcb *unp; 1384 struct xucred xu; 1385 int error, optval; 1386 1387 if (sopt->sopt_level != SOL_LOCAL) 1388 return (EINVAL); 1389 1390 unp = sotounpcb(so); 1391 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1392 error = 0; 1393 switch (sopt->sopt_dir) { 1394 case SOPT_GET: 1395 switch (sopt->sopt_name) { 1396 case LOCAL_PEERCRED: 1397 UNP_PCB_LOCK(unp); 1398 if (unp->unp_flags & UNP_HAVEPC) 1399 xu = unp->unp_peercred; 1400 else { 1401 if (so->so_type == SOCK_STREAM) 1402 error = ENOTCONN; 1403 else 1404 error = EINVAL; 1405 } 1406 UNP_PCB_UNLOCK(unp); 1407 if (error == 0) 1408 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1409 break; 1410 1411 case LOCAL_CREDS: 1412 /* Unlocked read. */ 1413 optval = unp->unp_flags & UNP_WANTCRED_ONESHOT ? 1 : 0; 1414 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1415 break; 1416 1417 case LOCAL_CREDS_PERSISTENT: 1418 /* Unlocked read. */ 1419 optval = unp->unp_flags & UNP_WANTCRED_ALWAYS ? 1 : 0; 1420 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1421 break; 1422 1423 case LOCAL_CONNWAIT: 1424 /* Unlocked read. */ 1425 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1426 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1427 break; 1428 1429 default: 1430 error = EOPNOTSUPP; 1431 break; 1432 } 1433 break; 1434 1435 case SOPT_SET: 1436 switch (sopt->sopt_name) { 1437 case LOCAL_CREDS: 1438 case LOCAL_CREDS_PERSISTENT: 1439 case LOCAL_CONNWAIT: 1440 error = sooptcopyin(sopt, &optval, sizeof(optval), 1441 sizeof(optval)); 1442 if (error) 1443 break; 1444 1445 #define OPTSET(bit, exclusive) do { \ 1446 UNP_PCB_LOCK(unp); \ 1447 if (optval) { \ 1448 if ((unp->unp_flags & (exclusive)) != 0) { \ 1449 UNP_PCB_UNLOCK(unp); \ 1450 error = EINVAL; \ 1451 break; \ 1452 } \ 1453 unp->unp_flags |= (bit); \ 1454 } else \ 1455 unp->unp_flags &= ~(bit); \ 1456 UNP_PCB_UNLOCK(unp); \ 1457 } while (0) 1458 1459 switch (sopt->sopt_name) { 1460 case LOCAL_CREDS: 1461 OPTSET(UNP_WANTCRED_ONESHOT, UNP_WANTCRED_ALWAYS); 1462 break; 1463 1464 case LOCAL_CREDS_PERSISTENT: 1465 OPTSET(UNP_WANTCRED_ALWAYS, UNP_WANTCRED_ONESHOT); 1466 break; 1467 1468 case LOCAL_CONNWAIT: 1469 OPTSET(UNP_CONNWAIT, 0); 1470 break; 1471 1472 default: 1473 break; 1474 } 1475 break; 1476 #undef OPTSET 1477 default: 1478 error = ENOPROTOOPT; 1479 break; 1480 } 1481 break; 1482 1483 default: 1484 error = EOPNOTSUPP; 1485 break; 1486 } 1487 return (error); 1488 } 1489 1490 static int 1491 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1492 { 1493 1494 return (unp_connectat(AT_FDCWD, so, nam, td)); 1495 } 1496 1497 static int 1498 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1499 struct thread *td) 1500 { 1501 struct mtx *vplock; 1502 struct sockaddr_un *soun; 1503 struct vnode *vp; 1504 struct socket *so2; 1505 struct unpcb *unp, *unp2, *unp3; 1506 struct nameidata nd; 1507 char buf[SOCK_MAXADDRLEN]; 1508 struct sockaddr *sa; 1509 cap_rights_t rights; 1510 int error, len; 1511 bool connreq; 1512 1513 if (nam->sa_family != AF_UNIX) 1514 return (EAFNOSUPPORT); 1515 if (nam->sa_len > sizeof(struct sockaddr_un)) 1516 return (EINVAL); 1517 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1518 if (len <= 0) 1519 return (EINVAL); 1520 soun = (struct sockaddr_un *)nam; 1521 bcopy(soun->sun_path, buf, len); 1522 buf[len] = 0; 1523 1524 unp = sotounpcb(so); 1525 UNP_PCB_LOCK(unp); 1526 for (;;) { 1527 /* 1528 * Wait for connection state to stabilize. If a connection 1529 * already exists, give up. For datagram sockets, which permit 1530 * multiple consecutive connect(2) calls, upper layers are 1531 * responsible for disconnecting in advance of a subsequent 1532 * connect(2), but this is not synchronized with PCB connection 1533 * state. 1534 * 1535 * Also make sure that no threads are currently attempting to 1536 * lock the peer socket, to ensure that unp_conn cannot 1537 * transition between two valid sockets while locks are dropped. 1538 */ 1539 if (unp->unp_conn != NULL) { 1540 UNP_PCB_UNLOCK(unp); 1541 return (EISCONN); 1542 } 1543 if ((unp->unp_flags & UNP_CONNECTING) != 0) { 1544 UNP_PCB_UNLOCK(unp); 1545 return (EALREADY); 1546 } 1547 if (unp->unp_pairbusy > 0) { 1548 unp->unp_flags |= UNP_WAITING; 1549 mtx_sleep(unp, UNP_PCB_LOCKPTR(unp), 0, "unpeer", 0); 1550 continue; 1551 } 1552 break; 1553 } 1554 unp->unp_flags |= UNP_CONNECTING; 1555 UNP_PCB_UNLOCK(unp); 1556 1557 connreq = (so->so_proto->pr_flags & PR_CONNREQUIRED) != 0; 1558 if (connreq) 1559 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1560 else 1561 sa = NULL; 1562 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1563 UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_CONNECTAT), 1564 td); 1565 error = namei(&nd); 1566 if (error) 1567 vp = NULL; 1568 else 1569 vp = nd.ni_vp; 1570 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1571 NDFREE_NOTHING(&nd); 1572 if (error) 1573 goto bad; 1574 1575 if (vp->v_type != VSOCK) { 1576 error = ENOTSOCK; 1577 goto bad; 1578 } 1579 #ifdef MAC 1580 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1581 if (error) 1582 goto bad; 1583 #endif 1584 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1585 if (error) 1586 goto bad; 1587 1588 unp = sotounpcb(so); 1589 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1590 1591 vplock = mtx_pool_find(mtxpool_sleep, vp); 1592 mtx_lock(vplock); 1593 VOP_UNP_CONNECT(vp, &unp2); 1594 if (unp2 == NULL) { 1595 error = ECONNREFUSED; 1596 goto bad2; 1597 } 1598 so2 = unp2->unp_socket; 1599 if (so->so_type != so2->so_type) { 1600 error = EPROTOTYPE; 1601 goto bad2; 1602 } 1603 if (connreq) { 1604 if (so2->so_options & SO_ACCEPTCONN) { 1605 CURVNET_SET(so2->so_vnet); 1606 so2 = sonewconn(so2, 0); 1607 CURVNET_RESTORE(); 1608 } else 1609 so2 = NULL; 1610 if (so2 == NULL) { 1611 error = ECONNREFUSED; 1612 goto bad2; 1613 } 1614 unp3 = sotounpcb(so2); 1615 unp_pcb_lock_pair(unp2, unp3); 1616 if (unp2->unp_addr != NULL) { 1617 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1618 unp3->unp_addr = (struct sockaddr_un *) sa; 1619 sa = NULL; 1620 } 1621 1622 unp_copy_peercred(td, unp3, unp, unp2); 1623 1624 UNP_PCB_UNLOCK(unp2); 1625 unp2 = unp3; 1626 1627 /* 1628 * It is safe to block on the PCB lock here since unp2 is 1629 * nascent and cannot be connected to any other sockets. 1630 */ 1631 UNP_PCB_LOCK(unp); 1632 #ifdef MAC 1633 mac_socketpeer_set_from_socket(so, so2); 1634 mac_socketpeer_set_from_socket(so2, so); 1635 #endif 1636 } else { 1637 unp_pcb_lock_pair(unp, unp2); 1638 } 1639 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1640 sotounpcb(so2) == unp2, 1641 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1642 error = unp_connect2(so, so2, PRU_CONNECT); 1643 unp_pcb_unlock_pair(unp, unp2); 1644 bad2: 1645 mtx_unlock(vplock); 1646 bad: 1647 if (vp != NULL) { 1648 vput(vp); 1649 } 1650 free(sa, M_SONAME); 1651 UNP_PCB_LOCK(unp); 1652 KASSERT((unp->unp_flags & UNP_CONNECTING) != 0, 1653 ("%s: unp %p has UNP_CONNECTING clear", __func__, unp)); 1654 unp->unp_flags &= ~UNP_CONNECTING; 1655 UNP_PCB_UNLOCK(unp); 1656 return (error); 1657 } 1658 1659 /* 1660 * Set socket peer credentials at connection time. 1661 * 1662 * The client's PCB credentials are copied from its process structure. The 1663 * server's PCB credentials are copied from the socket on which it called 1664 * listen(2). uipc_listen cached that process's credentials at the time. 1665 */ 1666 void 1667 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 1668 struct unpcb *server_unp, struct unpcb *listen_unp) 1669 { 1670 cru2xt(td, &client_unp->unp_peercred); 1671 client_unp->unp_flags |= UNP_HAVEPC; 1672 1673 memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred, 1674 sizeof(server_unp->unp_peercred)); 1675 server_unp->unp_flags |= UNP_HAVEPC; 1676 client_unp->unp_flags |= (listen_unp->unp_flags & UNP_WANTCRED_MASK); 1677 } 1678 1679 static int 1680 unp_connect2(struct socket *so, struct socket *so2, int req) 1681 { 1682 struct unpcb *unp; 1683 struct unpcb *unp2; 1684 1685 unp = sotounpcb(so); 1686 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1687 unp2 = sotounpcb(so2); 1688 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1689 1690 UNP_PCB_LOCK_ASSERT(unp); 1691 UNP_PCB_LOCK_ASSERT(unp2); 1692 KASSERT(unp->unp_conn == NULL, 1693 ("%s: socket %p is already connected", __func__, unp)); 1694 1695 if (so2->so_type != so->so_type) 1696 return (EPROTOTYPE); 1697 unp->unp_conn = unp2; 1698 unp_pcb_hold(unp2); 1699 unp_pcb_hold(unp); 1700 switch (so->so_type) { 1701 case SOCK_DGRAM: 1702 UNP_REF_LIST_LOCK(); 1703 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1704 UNP_REF_LIST_UNLOCK(); 1705 soisconnected(so); 1706 break; 1707 1708 case SOCK_STREAM: 1709 case SOCK_SEQPACKET: 1710 KASSERT(unp2->unp_conn == NULL, 1711 ("%s: socket %p is already connected", __func__, unp2)); 1712 unp2->unp_conn = unp; 1713 if (req == PRU_CONNECT && 1714 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1715 soisconnecting(so); 1716 else 1717 soisconnected(so); 1718 soisconnected(so2); 1719 break; 1720 1721 default: 1722 panic("unp_connect2"); 1723 } 1724 return (0); 1725 } 1726 1727 static void 1728 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1729 { 1730 struct socket *so, *so2; 1731 #ifdef INVARIANTS 1732 struct unpcb *unptmp; 1733 #endif 1734 1735 UNP_PCB_LOCK_ASSERT(unp); 1736 UNP_PCB_LOCK_ASSERT(unp2); 1737 KASSERT(unp->unp_conn == unp2, 1738 ("%s: unpcb %p is not connected to %p", __func__, unp, unp2)); 1739 1740 unp->unp_conn = NULL; 1741 so = unp->unp_socket; 1742 so2 = unp2->unp_socket; 1743 switch (unp->unp_socket->so_type) { 1744 case SOCK_DGRAM: 1745 UNP_REF_LIST_LOCK(); 1746 #ifdef INVARIANTS 1747 LIST_FOREACH(unptmp, &unp2->unp_refs, unp_reflink) { 1748 if (unptmp == unp) 1749 break; 1750 } 1751 KASSERT(unptmp != NULL, 1752 ("%s: %p not found in reflist of %p", __func__, unp, unp2)); 1753 #endif 1754 LIST_REMOVE(unp, unp_reflink); 1755 UNP_REF_LIST_UNLOCK(); 1756 if (so) { 1757 SOCK_LOCK(so); 1758 so->so_state &= ~SS_ISCONNECTED; 1759 SOCK_UNLOCK(so); 1760 } 1761 break; 1762 1763 case SOCK_STREAM: 1764 case SOCK_SEQPACKET: 1765 if (so) 1766 soisdisconnected(so); 1767 MPASS(unp2->unp_conn == unp); 1768 unp2->unp_conn = NULL; 1769 if (so2) 1770 soisdisconnected(so2); 1771 break; 1772 } 1773 1774 if (unp == unp2) { 1775 unp_pcb_rele_notlast(unp); 1776 if (!unp_pcb_rele(unp)) 1777 UNP_PCB_UNLOCK(unp); 1778 } else { 1779 if (!unp_pcb_rele(unp)) 1780 UNP_PCB_UNLOCK(unp); 1781 if (!unp_pcb_rele(unp2)) 1782 UNP_PCB_UNLOCK(unp2); 1783 } 1784 } 1785 1786 /* 1787 * unp_pcblist() walks the global list of struct unpcb's to generate a 1788 * pointer list, bumping the refcount on each unpcb. It then copies them out 1789 * sequentially, validating the generation number on each to see if it has 1790 * been detached. All of this is necessary because copyout() may sleep on 1791 * disk I/O. 1792 */ 1793 static int 1794 unp_pcblist(SYSCTL_HANDLER_ARGS) 1795 { 1796 struct unpcb *unp, **unp_list; 1797 unp_gen_t gencnt; 1798 struct xunpgen *xug; 1799 struct unp_head *head; 1800 struct xunpcb *xu; 1801 u_int i; 1802 int error, n; 1803 1804 switch ((intptr_t)arg1) { 1805 case SOCK_STREAM: 1806 head = &unp_shead; 1807 break; 1808 1809 case SOCK_DGRAM: 1810 head = &unp_dhead; 1811 break; 1812 1813 case SOCK_SEQPACKET: 1814 head = &unp_sphead; 1815 break; 1816 1817 default: 1818 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1819 } 1820 1821 /* 1822 * The process of preparing the PCB list is too time-consuming and 1823 * resource-intensive to repeat twice on every request. 1824 */ 1825 if (req->oldptr == NULL) { 1826 n = unp_count; 1827 req->oldidx = 2 * (sizeof *xug) 1828 + (n + n/8) * sizeof(struct xunpcb); 1829 return (0); 1830 } 1831 1832 if (req->newptr != NULL) 1833 return (EPERM); 1834 1835 /* 1836 * OK, now we're committed to doing something. 1837 */ 1838 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK | M_ZERO); 1839 UNP_LINK_RLOCK(); 1840 gencnt = unp_gencnt; 1841 n = unp_count; 1842 UNP_LINK_RUNLOCK(); 1843 1844 xug->xug_len = sizeof *xug; 1845 xug->xug_count = n; 1846 xug->xug_gen = gencnt; 1847 xug->xug_sogen = so_gencnt; 1848 error = SYSCTL_OUT(req, xug, sizeof *xug); 1849 if (error) { 1850 free(xug, M_TEMP); 1851 return (error); 1852 } 1853 1854 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1855 1856 UNP_LINK_RLOCK(); 1857 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1858 unp = LIST_NEXT(unp, unp_link)) { 1859 UNP_PCB_LOCK(unp); 1860 if (unp->unp_gencnt <= gencnt) { 1861 if (cr_cansee(req->td->td_ucred, 1862 unp->unp_socket->so_cred)) { 1863 UNP_PCB_UNLOCK(unp); 1864 continue; 1865 } 1866 unp_list[i++] = unp; 1867 unp_pcb_hold(unp); 1868 } 1869 UNP_PCB_UNLOCK(unp); 1870 } 1871 UNP_LINK_RUNLOCK(); 1872 n = i; /* In case we lost some during malloc. */ 1873 1874 error = 0; 1875 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1876 for (i = 0; i < n; i++) { 1877 unp = unp_list[i]; 1878 UNP_PCB_LOCK(unp); 1879 if (unp_pcb_rele(unp)) 1880 continue; 1881 1882 if (unp->unp_gencnt <= gencnt) { 1883 xu->xu_len = sizeof *xu; 1884 xu->xu_unpp = (uintptr_t)unp; 1885 /* 1886 * XXX - need more locking here to protect against 1887 * connect/disconnect races for SMP. 1888 */ 1889 if (unp->unp_addr != NULL) 1890 bcopy(unp->unp_addr, &xu->xu_addr, 1891 unp->unp_addr->sun_len); 1892 else 1893 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1894 if (unp->unp_conn != NULL && 1895 unp->unp_conn->unp_addr != NULL) 1896 bcopy(unp->unp_conn->unp_addr, 1897 &xu->xu_caddr, 1898 unp->unp_conn->unp_addr->sun_len); 1899 else 1900 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1901 xu->unp_vnode = (uintptr_t)unp->unp_vnode; 1902 xu->unp_conn = (uintptr_t)unp->unp_conn; 1903 xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs); 1904 xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink); 1905 xu->unp_gencnt = unp->unp_gencnt; 1906 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1907 UNP_PCB_UNLOCK(unp); 1908 error = SYSCTL_OUT(req, xu, sizeof *xu); 1909 } else { 1910 UNP_PCB_UNLOCK(unp); 1911 } 1912 } 1913 free(xu, M_TEMP); 1914 if (!error) { 1915 /* 1916 * Give the user an updated idea of our state. If the 1917 * generation differs from what we told her before, she knows 1918 * that something happened while we were processing this 1919 * request, and it might be necessary to retry. 1920 */ 1921 xug->xug_gen = unp_gencnt; 1922 xug->xug_sogen = so_gencnt; 1923 xug->xug_count = unp_count; 1924 error = SYSCTL_OUT(req, xug, sizeof *xug); 1925 } 1926 free(unp_list, M_TEMP); 1927 free(xug, M_TEMP); 1928 return (error); 1929 } 1930 1931 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, 1932 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1933 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1934 "List of active local datagram sockets"); 1935 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, 1936 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1937 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1938 "List of active local stream sockets"); 1939 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1940 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1941 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1942 "List of active local seqpacket sockets"); 1943 1944 static void 1945 unp_shutdown(struct unpcb *unp) 1946 { 1947 struct unpcb *unp2; 1948 struct socket *so; 1949 1950 UNP_PCB_LOCK_ASSERT(unp); 1951 1952 unp2 = unp->unp_conn; 1953 if ((unp->unp_socket->so_type == SOCK_STREAM || 1954 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1955 so = unp2->unp_socket; 1956 if (so != NULL) 1957 socantrcvmore(so); 1958 } 1959 } 1960 1961 static void 1962 unp_drop(struct unpcb *unp) 1963 { 1964 struct socket *so = unp->unp_socket; 1965 struct unpcb *unp2; 1966 1967 /* 1968 * Regardless of whether the socket's peer dropped the connection 1969 * with this socket by aborting or disconnecting, POSIX requires 1970 * that ECONNRESET is returned. 1971 */ 1972 1973 UNP_PCB_LOCK(unp); 1974 if (so) 1975 so->so_error = ECONNRESET; 1976 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) { 1977 /* Last reference dropped in unp_disconnect(). */ 1978 unp_pcb_rele_notlast(unp); 1979 unp_disconnect(unp, unp2); 1980 } else if (!unp_pcb_rele(unp)) { 1981 UNP_PCB_UNLOCK(unp); 1982 } 1983 } 1984 1985 static void 1986 unp_freerights(struct filedescent **fdep, int fdcount) 1987 { 1988 struct file *fp; 1989 int i; 1990 1991 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1992 1993 for (i = 0; i < fdcount; i++) { 1994 fp = fdep[i]->fde_file; 1995 filecaps_free(&fdep[i]->fde_caps); 1996 unp_discard(fp); 1997 } 1998 free(fdep[0], M_FILECAPS); 1999 } 2000 2001 static int 2002 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 2003 { 2004 struct thread *td = curthread; /* XXX */ 2005 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2006 int i; 2007 int *fdp; 2008 struct filedesc *fdesc = td->td_proc->p_fd; 2009 struct filedescent **fdep; 2010 void *data; 2011 socklen_t clen = control->m_len, datalen; 2012 int error, newfds; 2013 u_int newlen; 2014 2015 UNP_LINK_UNLOCK_ASSERT(); 2016 2017 error = 0; 2018 if (controlp != NULL) /* controlp == NULL => free control messages */ 2019 *controlp = NULL; 2020 while (cm != NULL) { 2021 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 2022 error = EINVAL; 2023 break; 2024 } 2025 data = CMSG_DATA(cm); 2026 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2027 if (cm->cmsg_level == SOL_SOCKET 2028 && cm->cmsg_type == SCM_RIGHTS) { 2029 newfds = datalen / sizeof(*fdep); 2030 if (newfds == 0) 2031 goto next; 2032 fdep = data; 2033 2034 /* If we're not outputting the descriptors free them. */ 2035 if (error || controlp == NULL) { 2036 unp_freerights(fdep, newfds); 2037 goto next; 2038 } 2039 FILEDESC_XLOCK(fdesc); 2040 2041 /* 2042 * Now change each pointer to an fd in the global 2043 * table to an integer that is the index to the local 2044 * fd table entry that we set up to point to the 2045 * global one we are transferring. 2046 */ 2047 newlen = newfds * sizeof(int); 2048 *controlp = sbcreatecontrol(NULL, newlen, 2049 SCM_RIGHTS, SOL_SOCKET); 2050 if (*controlp == NULL) { 2051 FILEDESC_XUNLOCK(fdesc); 2052 error = E2BIG; 2053 unp_freerights(fdep, newfds); 2054 goto next; 2055 } 2056 2057 fdp = (int *) 2058 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2059 if (fdallocn(td, 0, fdp, newfds) != 0) { 2060 FILEDESC_XUNLOCK(fdesc); 2061 error = EMSGSIZE; 2062 unp_freerights(fdep, newfds); 2063 m_freem(*controlp); 2064 *controlp = NULL; 2065 goto next; 2066 } 2067 for (i = 0; i < newfds; i++, fdp++) { 2068 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2069 (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0, 2070 &fdep[i]->fde_caps); 2071 unp_externalize_fp(fdep[i]->fde_file); 2072 } 2073 2074 /* 2075 * The new type indicates that the mbuf data refers to 2076 * kernel resources that may need to be released before 2077 * the mbuf is freed. 2078 */ 2079 m_chtype(*controlp, MT_EXTCONTROL); 2080 FILEDESC_XUNLOCK(fdesc); 2081 free(fdep[0], M_FILECAPS); 2082 } else { 2083 /* We can just copy anything else across. */ 2084 if (error || controlp == NULL) 2085 goto next; 2086 *controlp = sbcreatecontrol(NULL, datalen, 2087 cm->cmsg_type, cm->cmsg_level); 2088 if (*controlp == NULL) { 2089 error = ENOBUFS; 2090 goto next; 2091 } 2092 bcopy(data, 2093 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2094 datalen); 2095 } 2096 controlp = &(*controlp)->m_next; 2097 2098 next: 2099 if (CMSG_SPACE(datalen) < clen) { 2100 clen -= CMSG_SPACE(datalen); 2101 cm = (struct cmsghdr *) 2102 ((caddr_t)cm + CMSG_SPACE(datalen)); 2103 } else { 2104 clen = 0; 2105 cm = NULL; 2106 } 2107 } 2108 2109 m_freem(control); 2110 return (error); 2111 } 2112 2113 static void 2114 unp_zone_change(void *tag) 2115 { 2116 2117 uma_zone_set_max(unp_zone, maxsockets); 2118 } 2119 2120 #ifdef INVARIANTS 2121 static void 2122 unp_zdtor(void *mem, int size __unused, void *arg __unused) 2123 { 2124 struct unpcb *unp; 2125 2126 unp = mem; 2127 2128 KASSERT(LIST_EMPTY(&unp->unp_refs), 2129 ("%s: unpcb %p has lingering refs", __func__, unp)); 2130 KASSERT(unp->unp_socket == NULL, 2131 ("%s: unpcb %p has socket backpointer", __func__, unp)); 2132 KASSERT(unp->unp_vnode == NULL, 2133 ("%s: unpcb %p has vnode references", __func__, unp)); 2134 KASSERT(unp->unp_conn == NULL, 2135 ("%s: unpcb %p is still connected", __func__, unp)); 2136 KASSERT(unp->unp_addr == NULL, 2137 ("%s: unpcb %p has leaked addr", __func__, unp)); 2138 } 2139 #endif 2140 2141 static void 2142 unp_init(void) 2143 { 2144 uma_dtor dtor; 2145 2146 #ifdef VIMAGE 2147 if (!IS_DEFAULT_VNET(curvnet)) 2148 return; 2149 #endif 2150 2151 #ifdef INVARIANTS 2152 dtor = unp_zdtor; 2153 #else 2154 dtor = NULL; 2155 #endif 2156 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, dtor, 2157 NULL, NULL, UMA_ALIGN_CACHE, 0); 2158 uma_zone_set_max(unp_zone, maxsockets); 2159 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2160 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2161 NULL, EVENTHANDLER_PRI_ANY); 2162 LIST_INIT(&unp_dhead); 2163 LIST_INIT(&unp_shead); 2164 LIST_INIT(&unp_sphead); 2165 SLIST_INIT(&unp_defers); 2166 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2167 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2168 UNP_LINK_LOCK_INIT(); 2169 UNP_DEFERRED_LOCK_INIT(); 2170 } 2171 2172 static void 2173 unp_internalize_cleanup_rights(struct mbuf *control) 2174 { 2175 struct cmsghdr *cp; 2176 struct mbuf *m; 2177 void *data; 2178 socklen_t datalen; 2179 2180 for (m = control; m != NULL; m = m->m_next) { 2181 cp = mtod(m, struct cmsghdr *); 2182 if (cp->cmsg_level != SOL_SOCKET || 2183 cp->cmsg_type != SCM_RIGHTS) 2184 continue; 2185 data = CMSG_DATA(cp); 2186 datalen = (caddr_t)cp + cp->cmsg_len - (caddr_t)data; 2187 unp_freerights(data, datalen / sizeof(struct filedesc *)); 2188 } 2189 } 2190 2191 static int 2192 unp_internalize(struct mbuf **controlp, struct thread *td) 2193 { 2194 struct mbuf *control, **initial_controlp; 2195 struct proc *p; 2196 struct filedesc *fdesc; 2197 struct bintime *bt; 2198 struct cmsghdr *cm; 2199 struct cmsgcred *cmcred; 2200 struct filedescent *fde, **fdep, *fdev; 2201 struct file *fp; 2202 struct timeval *tv; 2203 struct timespec *ts; 2204 void *data; 2205 socklen_t clen, datalen; 2206 int i, j, error, *fdp, oldfds; 2207 u_int newlen; 2208 2209 UNP_LINK_UNLOCK_ASSERT(); 2210 2211 p = td->td_proc; 2212 fdesc = p->p_fd; 2213 error = 0; 2214 control = *controlp; 2215 clen = control->m_len; 2216 *controlp = NULL; 2217 initial_controlp = controlp; 2218 for (cm = mtod(control, struct cmsghdr *); cm != NULL;) { 2219 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2220 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2221 error = EINVAL; 2222 goto out; 2223 } 2224 data = CMSG_DATA(cm); 2225 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2226 2227 switch (cm->cmsg_type) { 2228 /* 2229 * Fill in credential information. 2230 */ 2231 case SCM_CREDS: 2232 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2233 SCM_CREDS, SOL_SOCKET); 2234 if (*controlp == NULL) { 2235 error = ENOBUFS; 2236 goto out; 2237 } 2238 cmcred = (struct cmsgcred *) 2239 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2240 cmcred->cmcred_pid = p->p_pid; 2241 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2242 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2243 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2244 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2245 CMGROUP_MAX); 2246 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2247 cmcred->cmcred_groups[i] = 2248 td->td_ucred->cr_groups[i]; 2249 break; 2250 2251 case SCM_RIGHTS: 2252 oldfds = datalen / sizeof (int); 2253 if (oldfds == 0) 2254 break; 2255 /* 2256 * Check that all the FDs passed in refer to legal 2257 * files. If not, reject the entire operation. 2258 */ 2259 fdp = data; 2260 FILEDESC_SLOCK(fdesc); 2261 for (i = 0; i < oldfds; i++, fdp++) { 2262 fp = fget_locked(fdesc, *fdp); 2263 if (fp == NULL) { 2264 FILEDESC_SUNLOCK(fdesc); 2265 error = EBADF; 2266 goto out; 2267 } 2268 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2269 FILEDESC_SUNLOCK(fdesc); 2270 error = EOPNOTSUPP; 2271 goto out; 2272 } 2273 } 2274 2275 /* 2276 * Now replace the integer FDs with pointers to the 2277 * file structure and capability rights. 2278 */ 2279 newlen = oldfds * sizeof(fdep[0]); 2280 *controlp = sbcreatecontrol(NULL, newlen, 2281 SCM_RIGHTS, SOL_SOCKET); 2282 if (*controlp == NULL) { 2283 FILEDESC_SUNLOCK(fdesc); 2284 error = E2BIG; 2285 goto out; 2286 } 2287 fdp = data; 2288 for (i = 0; i < oldfds; i++, fdp++) { 2289 if (!fhold(fdesc->fd_ofiles[*fdp].fde_file)) { 2290 fdp = data; 2291 for (j = 0; j < i; j++, fdp++) { 2292 fdrop(fdesc->fd_ofiles[*fdp]. 2293 fde_file, td); 2294 } 2295 FILEDESC_SUNLOCK(fdesc); 2296 error = EBADF; 2297 goto out; 2298 } 2299 } 2300 fdp = data; 2301 fdep = (struct filedescent **) 2302 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2303 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2304 M_WAITOK); 2305 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2306 fde = &fdesc->fd_ofiles[*fdp]; 2307 fdep[i] = fdev; 2308 fdep[i]->fde_file = fde->fde_file; 2309 filecaps_copy(&fde->fde_caps, 2310 &fdep[i]->fde_caps, true); 2311 unp_internalize_fp(fdep[i]->fde_file); 2312 } 2313 FILEDESC_SUNLOCK(fdesc); 2314 break; 2315 2316 case SCM_TIMESTAMP: 2317 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2318 SCM_TIMESTAMP, SOL_SOCKET); 2319 if (*controlp == NULL) { 2320 error = ENOBUFS; 2321 goto out; 2322 } 2323 tv = (struct timeval *) 2324 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2325 microtime(tv); 2326 break; 2327 2328 case SCM_BINTIME: 2329 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2330 SCM_BINTIME, SOL_SOCKET); 2331 if (*controlp == NULL) { 2332 error = ENOBUFS; 2333 goto out; 2334 } 2335 bt = (struct bintime *) 2336 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2337 bintime(bt); 2338 break; 2339 2340 case SCM_REALTIME: 2341 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2342 SCM_REALTIME, SOL_SOCKET); 2343 if (*controlp == NULL) { 2344 error = ENOBUFS; 2345 goto out; 2346 } 2347 ts = (struct timespec *) 2348 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2349 nanotime(ts); 2350 break; 2351 2352 case SCM_MONOTONIC: 2353 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2354 SCM_MONOTONIC, SOL_SOCKET); 2355 if (*controlp == NULL) { 2356 error = ENOBUFS; 2357 goto out; 2358 } 2359 ts = (struct timespec *) 2360 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2361 nanouptime(ts); 2362 break; 2363 2364 default: 2365 error = EINVAL; 2366 goto out; 2367 } 2368 2369 if (*controlp != NULL) 2370 controlp = &(*controlp)->m_next; 2371 if (CMSG_SPACE(datalen) < clen) { 2372 clen -= CMSG_SPACE(datalen); 2373 cm = (struct cmsghdr *) 2374 ((caddr_t)cm + CMSG_SPACE(datalen)); 2375 } else { 2376 clen = 0; 2377 cm = NULL; 2378 } 2379 } 2380 2381 out: 2382 if (error != 0 && initial_controlp != NULL) 2383 unp_internalize_cleanup_rights(*initial_controlp); 2384 m_freem(control); 2385 return (error); 2386 } 2387 2388 static struct mbuf * 2389 unp_addsockcred(struct thread *td, struct mbuf *control, int mode) 2390 { 2391 struct mbuf *m, *n, *n_prev; 2392 const struct cmsghdr *cm; 2393 int ngroups, i, cmsgtype; 2394 size_t ctrlsz; 2395 2396 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2397 if (mode & UNP_WANTCRED_ALWAYS) { 2398 ctrlsz = SOCKCRED2SIZE(ngroups); 2399 cmsgtype = SCM_CREDS2; 2400 } else { 2401 ctrlsz = SOCKCREDSIZE(ngroups); 2402 cmsgtype = SCM_CREDS; 2403 } 2404 2405 m = sbcreatecontrol(NULL, ctrlsz, cmsgtype, SOL_SOCKET); 2406 if (m == NULL) 2407 return (control); 2408 2409 if (mode & UNP_WANTCRED_ALWAYS) { 2410 struct sockcred2 *sc; 2411 2412 sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *)); 2413 sc->sc_version = 0; 2414 sc->sc_pid = td->td_proc->p_pid; 2415 sc->sc_uid = td->td_ucred->cr_ruid; 2416 sc->sc_euid = td->td_ucred->cr_uid; 2417 sc->sc_gid = td->td_ucred->cr_rgid; 2418 sc->sc_egid = td->td_ucred->cr_gid; 2419 sc->sc_ngroups = ngroups; 2420 for (i = 0; i < sc->sc_ngroups; i++) 2421 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2422 } else { 2423 struct sockcred *sc; 2424 2425 sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *)); 2426 sc->sc_uid = td->td_ucred->cr_ruid; 2427 sc->sc_euid = td->td_ucred->cr_uid; 2428 sc->sc_gid = td->td_ucred->cr_rgid; 2429 sc->sc_egid = td->td_ucred->cr_gid; 2430 sc->sc_ngroups = ngroups; 2431 for (i = 0; i < sc->sc_ngroups; i++) 2432 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2433 } 2434 2435 /* 2436 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2437 * created SCM_CREDS control message (struct sockcred) has another 2438 * format. 2439 */ 2440 if (control != NULL && cmsgtype == SCM_CREDS) 2441 for (n = control, n_prev = NULL; n != NULL;) { 2442 cm = mtod(n, struct cmsghdr *); 2443 if (cm->cmsg_level == SOL_SOCKET && 2444 cm->cmsg_type == SCM_CREDS) { 2445 if (n_prev == NULL) 2446 control = n->m_next; 2447 else 2448 n_prev->m_next = n->m_next; 2449 n = m_free(n); 2450 } else { 2451 n_prev = n; 2452 n = n->m_next; 2453 } 2454 } 2455 2456 /* Prepend it to the head. */ 2457 m->m_next = control; 2458 return (m); 2459 } 2460 2461 static struct unpcb * 2462 fptounp(struct file *fp) 2463 { 2464 struct socket *so; 2465 2466 if (fp->f_type != DTYPE_SOCKET) 2467 return (NULL); 2468 if ((so = fp->f_data) == NULL) 2469 return (NULL); 2470 if (so->so_proto->pr_domain != &localdomain) 2471 return (NULL); 2472 return sotounpcb(so); 2473 } 2474 2475 static void 2476 unp_discard(struct file *fp) 2477 { 2478 struct unp_defer *dr; 2479 2480 if (unp_externalize_fp(fp)) { 2481 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2482 dr->ud_fp = fp; 2483 UNP_DEFERRED_LOCK(); 2484 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2485 UNP_DEFERRED_UNLOCK(); 2486 atomic_add_int(&unp_defers_count, 1); 2487 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2488 } else 2489 closef_nothread(fp); 2490 } 2491 2492 static void 2493 unp_process_defers(void *arg __unused, int pending) 2494 { 2495 struct unp_defer *dr; 2496 SLIST_HEAD(, unp_defer) drl; 2497 int count; 2498 2499 SLIST_INIT(&drl); 2500 for (;;) { 2501 UNP_DEFERRED_LOCK(); 2502 if (SLIST_FIRST(&unp_defers) == NULL) { 2503 UNP_DEFERRED_UNLOCK(); 2504 break; 2505 } 2506 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2507 UNP_DEFERRED_UNLOCK(); 2508 count = 0; 2509 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2510 SLIST_REMOVE_HEAD(&drl, ud_link); 2511 closef_nothread(dr->ud_fp); 2512 free(dr, M_TEMP); 2513 count++; 2514 } 2515 atomic_add_int(&unp_defers_count, -count); 2516 } 2517 } 2518 2519 static void 2520 unp_internalize_fp(struct file *fp) 2521 { 2522 struct unpcb *unp; 2523 2524 UNP_LINK_WLOCK(); 2525 if ((unp = fptounp(fp)) != NULL) { 2526 unp->unp_file = fp; 2527 unp->unp_msgcount++; 2528 } 2529 unp_rights++; 2530 UNP_LINK_WUNLOCK(); 2531 } 2532 2533 static int 2534 unp_externalize_fp(struct file *fp) 2535 { 2536 struct unpcb *unp; 2537 int ret; 2538 2539 UNP_LINK_WLOCK(); 2540 if ((unp = fptounp(fp)) != NULL) { 2541 unp->unp_msgcount--; 2542 ret = 1; 2543 } else 2544 ret = 0; 2545 unp_rights--; 2546 UNP_LINK_WUNLOCK(); 2547 return (ret); 2548 } 2549 2550 /* 2551 * unp_defer indicates whether additional work has been defered for a future 2552 * pass through unp_gc(). It is thread local and does not require explicit 2553 * synchronization. 2554 */ 2555 static int unp_marked; 2556 2557 static void 2558 unp_remove_dead_ref(struct filedescent **fdep, int fdcount) 2559 { 2560 struct unpcb *unp; 2561 struct file *fp; 2562 int i; 2563 2564 /* 2565 * This function can only be called from the gc task. 2566 */ 2567 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2568 ("%s: not on gc callout", __func__)); 2569 UNP_LINK_LOCK_ASSERT(); 2570 2571 for (i = 0; i < fdcount; i++) { 2572 fp = fdep[i]->fde_file; 2573 if ((unp = fptounp(fp)) == NULL) 2574 continue; 2575 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2576 continue; 2577 unp->unp_gcrefs--; 2578 } 2579 } 2580 2581 static void 2582 unp_restore_undead_ref(struct filedescent **fdep, int fdcount) 2583 { 2584 struct unpcb *unp; 2585 struct file *fp; 2586 int i; 2587 2588 /* 2589 * This function can only be called from the gc task. 2590 */ 2591 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2592 ("%s: not on gc callout", __func__)); 2593 UNP_LINK_LOCK_ASSERT(); 2594 2595 for (i = 0; i < fdcount; i++) { 2596 fp = fdep[i]->fde_file; 2597 if ((unp = fptounp(fp)) == NULL) 2598 continue; 2599 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2600 continue; 2601 unp->unp_gcrefs++; 2602 unp_marked++; 2603 } 2604 } 2605 2606 static void 2607 unp_gc_scan(struct unpcb *unp, void (*op)(struct filedescent **, int)) 2608 { 2609 struct socket *so, *soa; 2610 2611 so = unp->unp_socket; 2612 SOCK_LOCK(so); 2613 if (SOLISTENING(so)) { 2614 /* 2615 * Mark all sockets in our accept queue. 2616 */ 2617 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2618 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2619 continue; 2620 SOCKBUF_LOCK(&soa->so_rcv); 2621 unp_scan(soa->so_rcv.sb_mb, op); 2622 SOCKBUF_UNLOCK(&soa->so_rcv); 2623 } 2624 } else { 2625 /* 2626 * Mark all sockets we reference with RIGHTS. 2627 */ 2628 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2629 SOCKBUF_LOCK(&so->so_rcv); 2630 unp_scan(so->so_rcv.sb_mb, op); 2631 SOCKBUF_UNLOCK(&so->so_rcv); 2632 } 2633 } 2634 SOCK_UNLOCK(so); 2635 } 2636 2637 static int unp_recycled; 2638 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2639 "Number of unreachable sockets claimed by the garbage collector."); 2640 2641 static int unp_taskcount; 2642 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2643 "Number of times the garbage collector has run."); 2644 2645 SYSCTL_UINT(_net_local, OID_AUTO, sockcount, CTLFLAG_RD, &unp_count, 0, 2646 "Number of active local sockets."); 2647 2648 static void 2649 unp_gc(__unused void *arg, int pending) 2650 { 2651 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2652 NULL }; 2653 struct unp_head **head; 2654 struct unp_head unp_deadhead; /* List of potentially-dead sockets. */ 2655 struct file *f, **unref; 2656 struct unpcb *unp, *unptmp; 2657 int i, total, unp_unreachable; 2658 2659 LIST_INIT(&unp_deadhead); 2660 unp_taskcount++; 2661 UNP_LINK_RLOCK(); 2662 /* 2663 * First determine which sockets may be in cycles. 2664 */ 2665 unp_unreachable = 0; 2666 2667 for (head = heads; *head != NULL; head++) 2668 LIST_FOREACH(unp, *head, unp_link) { 2669 KASSERT((unp->unp_gcflag & ~UNPGC_IGNORE_RIGHTS) == 0, 2670 ("%s: unp %p has unexpected gc flags 0x%x", 2671 __func__, unp, (unsigned int)unp->unp_gcflag)); 2672 2673 f = unp->unp_file; 2674 2675 /* 2676 * Check for an unreachable socket potentially in a 2677 * cycle. It must be in a queue as indicated by 2678 * msgcount, and this must equal the file reference 2679 * count. Note that when msgcount is 0 the file is 2680 * NULL. 2681 */ 2682 if (f != NULL && unp->unp_msgcount != 0 && 2683 refcount_load(&f->f_count) == unp->unp_msgcount) { 2684 LIST_INSERT_HEAD(&unp_deadhead, unp, unp_dead); 2685 unp->unp_gcflag |= UNPGC_DEAD; 2686 unp->unp_gcrefs = unp->unp_msgcount; 2687 unp_unreachable++; 2688 } 2689 } 2690 2691 /* 2692 * Scan all sockets previously marked as potentially being in a cycle 2693 * and remove the references each socket holds on any UNPGC_DEAD 2694 * sockets in its queue. After this step, all remaining references on 2695 * sockets marked UNPGC_DEAD should not be part of any cycle. 2696 */ 2697 LIST_FOREACH(unp, &unp_deadhead, unp_dead) 2698 unp_gc_scan(unp, unp_remove_dead_ref); 2699 2700 /* 2701 * If a socket still has a non-negative refcount, it cannot be in a 2702 * cycle. In this case increment refcount of all children iteratively. 2703 * Stop the scan once we do a complete loop without discovering 2704 * a new reachable socket. 2705 */ 2706 do { 2707 unp_marked = 0; 2708 LIST_FOREACH_SAFE(unp, &unp_deadhead, unp_dead, unptmp) 2709 if (unp->unp_gcrefs > 0) { 2710 unp->unp_gcflag &= ~UNPGC_DEAD; 2711 LIST_REMOVE(unp, unp_dead); 2712 KASSERT(unp_unreachable > 0, 2713 ("%s: unp_unreachable underflow.", 2714 __func__)); 2715 unp_unreachable--; 2716 unp_gc_scan(unp, unp_restore_undead_ref); 2717 } 2718 } while (unp_marked); 2719 2720 UNP_LINK_RUNLOCK(); 2721 2722 if (unp_unreachable == 0) 2723 return; 2724 2725 /* 2726 * Allocate space for a local array of dead unpcbs. 2727 * TODO: can this path be simplified by instead using the local 2728 * dead list at unp_deadhead, after taking out references 2729 * on the file object and/or unpcb and dropping the link lock? 2730 */ 2731 unref = malloc(unp_unreachable * sizeof(struct file *), 2732 M_TEMP, M_WAITOK); 2733 2734 /* 2735 * Iterate looking for sockets which have been specifically marked 2736 * as unreachable and store them locally. 2737 */ 2738 UNP_LINK_RLOCK(); 2739 total = 0; 2740 LIST_FOREACH(unp, &unp_deadhead, unp_dead) { 2741 KASSERT((unp->unp_gcflag & UNPGC_DEAD) != 0, 2742 ("%s: unp %p not marked UNPGC_DEAD", __func__, unp)); 2743 unp->unp_gcflag &= ~UNPGC_DEAD; 2744 f = unp->unp_file; 2745 if (unp->unp_msgcount == 0 || f == NULL || 2746 refcount_load(&f->f_count) != unp->unp_msgcount || 2747 !fhold(f)) 2748 continue; 2749 unref[total++] = f; 2750 KASSERT(total <= unp_unreachable, 2751 ("%s: incorrect unreachable count.", __func__)); 2752 } 2753 UNP_LINK_RUNLOCK(); 2754 2755 /* 2756 * Now flush all sockets, free'ing rights. This will free the 2757 * struct files associated with these sockets but leave each socket 2758 * with one remaining ref. 2759 */ 2760 for (i = 0; i < total; i++) { 2761 struct socket *so; 2762 2763 so = unref[i]->f_data; 2764 CURVNET_SET(so->so_vnet); 2765 sorflush(so); 2766 CURVNET_RESTORE(); 2767 } 2768 2769 /* 2770 * And finally release the sockets so they can be reclaimed. 2771 */ 2772 for (i = 0; i < total; i++) 2773 fdrop(unref[i], NULL); 2774 unp_recycled += total; 2775 free(unref, M_TEMP); 2776 } 2777 2778 static void 2779 unp_dispose_mbuf(struct mbuf *m) 2780 { 2781 2782 if (m) 2783 unp_scan(m, unp_freerights); 2784 } 2785 2786 /* 2787 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2788 */ 2789 static void 2790 unp_dispose(struct socket *so) 2791 { 2792 struct unpcb *unp; 2793 2794 unp = sotounpcb(so); 2795 UNP_LINK_WLOCK(); 2796 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2797 UNP_LINK_WUNLOCK(); 2798 if (!SOLISTENING(so)) 2799 unp_dispose_mbuf(so->so_rcv.sb_mb); 2800 } 2801 2802 static void 2803 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2804 { 2805 struct mbuf *m; 2806 struct cmsghdr *cm; 2807 void *data; 2808 socklen_t clen, datalen; 2809 2810 while (m0 != NULL) { 2811 for (m = m0; m; m = m->m_next) { 2812 if (m->m_type != MT_CONTROL) 2813 continue; 2814 2815 cm = mtod(m, struct cmsghdr *); 2816 clen = m->m_len; 2817 2818 while (cm != NULL) { 2819 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2820 break; 2821 2822 data = CMSG_DATA(cm); 2823 datalen = (caddr_t)cm + cm->cmsg_len 2824 - (caddr_t)data; 2825 2826 if (cm->cmsg_level == SOL_SOCKET && 2827 cm->cmsg_type == SCM_RIGHTS) { 2828 (*op)(data, datalen / 2829 sizeof(struct filedescent *)); 2830 } 2831 2832 if (CMSG_SPACE(datalen) < clen) { 2833 clen -= CMSG_SPACE(datalen); 2834 cm = (struct cmsghdr *) 2835 ((caddr_t)cm + CMSG_SPACE(datalen)); 2836 } else { 2837 clen = 0; 2838 cm = NULL; 2839 } 2840 } 2841 } 2842 m0 = m0->m_nextpkt; 2843 } 2844 } 2845 2846 /* 2847 * A helper function called by VFS before socket-type vnode reclamation. 2848 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2849 * use count. 2850 */ 2851 void 2852 vfs_unp_reclaim(struct vnode *vp) 2853 { 2854 struct unpcb *unp; 2855 int active; 2856 struct mtx *vplock; 2857 2858 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2859 KASSERT(vp->v_type == VSOCK, 2860 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2861 2862 active = 0; 2863 vplock = mtx_pool_find(mtxpool_sleep, vp); 2864 mtx_lock(vplock); 2865 VOP_UNP_CONNECT(vp, &unp); 2866 if (unp == NULL) 2867 goto done; 2868 UNP_PCB_LOCK(unp); 2869 if (unp->unp_vnode == vp) { 2870 VOP_UNP_DETACH(vp); 2871 unp->unp_vnode = NULL; 2872 active = 1; 2873 } 2874 UNP_PCB_UNLOCK(unp); 2875 done: 2876 mtx_unlock(vplock); 2877 if (active) 2878 vunref(vp); 2879 } 2880 2881 #ifdef DDB 2882 static void 2883 db_print_indent(int indent) 2884 { 2885 int i; 2886 2887 for (i = 0; i < indent; i++) 2888 db_printf(" "); 2889 } 2890 2891 static void 2892 db_print_unpflags(int unp_flags) 2893 { 2894 int comma; 2895 2896 comma = 0; 2897 if (unp_flags & UNP_HAVEPC) { 2898 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2899 comma = 1; 2900 } 2901 if (unp_flags & UNP_WANTCRED_ALWAYS) { 2902 db_printf("%sUNP_WANTCRED_ALWAYS", comma ? ", " : ""); 2903 comma = 1; 2904 } 2905 if (unp_flags & UNP_WANTCRED_ONESHOT) { 2906 db_printf("%sUNP_WANTCRED_ONESHOT", comma ? ", " : ""); 2907 comma = 1; 2908 } 2909 if (unp_flags & UNP_CONNWAIT) { 2910 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2911 comma = 1; 2912 } 2913 if (unp_flags & UNP_CONNECTING) { 2914 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2915 comma = 1; 2916 } 2917 if (unp_flags & UNP_BINDING) { 2918 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2919 comma = 1; 2920 } 2921 } 2922 2923 static void 2924 db_print_xucred(int indent, struct xucred *xu) 2925 { 2926 int comma, i; 2927 2928 db_print_indent(indent); 2929 db_printf("cr_version: %u cr_uid: %u cr_pid: %d cr_ngroups: %d\n", 2930 xu->cr_version, xu->cr_uid, xu->cr_pid, xu->cr_ngroups); 2931 db_print_indent(indent); 2932 db_printf("cr_groups: "); 2933 comma = 0; 2934 for (i = 0; i < xu->cr_ngroups; i++) { 2935 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2936 comma = 1; 2937 } 2938 db_printf("\n"); 2939 } 2940 2941 static void 2942 db_print_unprefs(int indent, struct unp_head *uh) 2943 { 2944 struct unpcb *unp; 2945 int counter; 2946 2947 counter = 0; 2948 LIST_FOREACH(unp, uh, unp_reflink) { 2949 if (counter % 4 == 0) 2950 db_print_indent(indent); 2951 db_printf("%p ", unp); 2952 if (counter % 4 == 3) 2953 db_printf("\n"); 2954 counter++; 2955 } 2956 if (counter != 0 && counter % 4 != 0) 2957 db_printf("\n"); 2958 } 2959 2960 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2961 { 2962 struct unpcb *unp; 2963 2964 if (!have_addr) { 2965 db_printf("usage: show unpcb <addr>\n"); 2966 return; 2967 } 2968 unp = (struct unpcb *)addr; 2969 2970 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2971 unp->unp_vnode); 2972 2973 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2974 unp->unp_conn); 2975 2976 db_printf("unp_refs:\n"); 2977 db_print_unprefs(2, &unp->unp_refs); 2978 2979 /* XXXRW: Would be nice to print the full address, if any. */ 2980 db_printf("unp_addr: %p\n", unp->unp_addr); 2981 2982 db_printf("unp_gencnt: %llu\n", 2983 (unsigned long long)unp->unp_gencnt); 2984 2985 db_printf("unp_flags: %x (", unp->unp_flags); 2986 db_print_unpflags(unp->unp_flags); 2987 db_printf(")\n"); 2988 2989 db_printf("unp_peercred:\n"); 2990 db_print_xucred(2, &unp->unp_peercred); 2991 2992 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2993 } 2994 #endif 2995