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_CAPATTACH, 433 .pr_ctloutput = &uipc_ctloutput, 434 .pr_usrreqs = &uipc_usrreqs_stream 435 }, 436 { 437 .pr_type = SOCK_DGRAM, 438 .pr_domain = &localdomain, 439 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS|PR_CAPATTACH, 440 .pr_ctloutput = &uipc_ctloutput, 441 .pr_usrreqs = &uipc_usrreqs_dgram 442 }, 443 { 444 .pr_type = SOCK_SEQPACKET, 445 .pr_domain = &localdomain, 446 447 /* 448 * XXXRW: For now, PR_ADDR because soreceive will bump into them 449 * due to our use of sbappendaddr. A new sbappend variants is needed 450 * that supports both atomic record writes and control data. 451 */ 452 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED| 453 PR_WANTRCVD|PR_RIGHTS|PR_CAPATTACH, 454 .pr_ctloutput = &uipc_ctloutput, 455 .pr_usrreqs = &uipc_usrreqs_seqpacket, 456 }, 457 }; 458 459 static struct domain localdomain = { 460 .dom_family = AF_LOCAL, 461 .dom_name = "local", 462 .dom_init = unp_init, 463 .dom_externalize = unp_externalize, 464 .dom_dispose = unp_dispose, 465 .dom_protosw = localsw, 466 .dom_protoswNPROTOSW = &localsw[nitems(localsw)] 467 }; 468 DOMAIN_SET(local); 469 470 static void 471 uipc_abort(struct socket *so) 472 { 473 struct unpcb *unp, *unp2; 474 475 unp = sotounpcb(so); 476 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 477 UNP_PCB_UNLOCK_ASSERT(unp); 478 479 UNP_PCB_LOCK(unp); 480 unp2 = unp->unp_conn; 481 if (unp2 != NULL) { 482 unp_pcb_hold(unp2); 483 UNP_PCB_UNLOCK(unp); 484 unp_drop(unp2); 485 } else 486 UNP_PCB_UNLOCK(unp); 487 } 488 489 static int 490 uipc_accept(struct socket *so, struct sockaddr **nam) 491 { 492 struct unpcb *unp, *unp2; 493 const struct sockaddr *sa; 494 495 /* 496 * Pass back name of connected socket, if it was bound and we are 497 * still connected (our peer may have closed already!). 498 */ 499 unp = sotounpcb(so); 500 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 501 502 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 503 UNP_PCB_LOCK(unp); 504 unp2 = unp_pcb_lock_peer(unp); 505 if (unp2 != NULL && unp2->unp_addr != NULL) 506 sa = (struct sockaddr *)unp2->unp_addr; 507 else 508 sa = &sun_noname; 509 bcopy(sa, *nam, sa->sa_len); 510 if (unp2 != NULL) 511 unp_pcb_unlock_pair(unp, unp2); 512 else 513 UNP_PCB_UNLOCK(unp); 514 return (0); 515 } 516 517 static int 518 uipc_attach(struct socket *so, int proto, struct thread *td) 519 { 520 u_long sendspace, recvspace; 521 struct unpcb *unp; 522 int error; 523 bool locked; 524 525 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 526 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 527 switch (so->so_type) { 528 case SOCK_STREAM: 529 sendspace = unpst_sendspace; 530 recvspace = unpst_recvspace; 531 break; 532 533 case SOCK_DGRAM: 534 sendspace = unpdg_sendspace; 535 recvspace = unpdg_recvspace; 536 break; 537 538 case SOCK_SEQPACKET: 539 sendspace = unpsp_sendspace; 540 recvspace = unpsp_recvspace; 541 break; 542 543 default: 544 panic("uipc_attach"); 545 } 546 error = soreserve(so, sendspace, recvspace); 547 if (error) 548 return (error); 549 } 550 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 551 if (unp == NULL) 552 return (ENOBUFS); 553 LIST_INIT(&unp->unp_refs); 554 UNP_PCB_LOCK_INIT(unp); 555 unp->unp_socket = so; 556 so->so_pcb = unp; 557 refcount_init(&unp->unp_refcount, 1); 558 559 if ((locked = UNP_LINK_WOWNED()) == false) 560 UNP_LINK_WLOCK(); 561 562 unp->unp_gencnt = ++unp_gencnt; 563 unp->unp_ino = ++unp_ino; 564 unp_count++; 565 switch (so->so_type) { 566 case SOCK_STREAM: 567 LIST_INSERT_HEAD(&unp_shead, unp, unp_link); 568 break; 569 570 case SOCK_DGRAM: 571 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link); 572 break; 573 574 case SOCK_SEQPACKET: 575 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link); 576 break; 577 578 default: 579 panic("uipc_attach"); 580 } 581 582 if (locked == false) 583 UNP_LINK_WUNLOCK(); 584 585 return (0); 586 } 587 588 static int 589 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td) 590 { 591 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 592 struct vattr vattr; 593 int error, namelen; 594 struct nameidata nd; 595 struct unpcb *unp; 596 struct vnode *vp; 597 struct mount *mp; 598 cap_rights_t rights; 599 char *buf; 600 601 if (nam->sa_family != AF_UNIX) 602 return (EAFNOSUPPORT); 603 604 unp = sotounpcb(so); 605 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 606 607 if (soun->sun_len > sizeof(struct sockaddr_un)) 608 return (EINVAL); 609 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 610 if (namelen <= 0) 611 return (EINVAL); 612 613 /* 614 * We don't allow simultaneous bind() calls on a single UNIX domain 615 * socket, so flag in-progress operations, and return an error if an 616 * operation is already in progress. 617 * 618 * Historically, we have not allowed a socket to be rebound, so this 619 * also returns an error. Not allowing re-binding simplifies the 620 * implementation and avoids a great many possible failure modes. 621 */ 622 UNP_PCB_LOCK(unp); 623 if (unp->unp_vnode != NULL) { 624 UNP_PCB_UNLOCK(unp); 625 return (EINVAL); 626 } 627 if (unp->unp_flags & UNP_BINDING) { 628 UNP_PCB_UNLOCK(unp); 629 return (EALREADY); 630 } 631 unp->unp_flags |= UNP_BINDING; 632 UNP_PCB_UNLOCK(unp); 633 634 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 635 bcopy(soun->sun_path, buf, namelen); 636 buf[namelen] = 0; 637 638 restart: 639 NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE, 640 UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_BINDAT), 641 td); 642 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 643 error = namei(&nd); 644 if (error) 645 goto error; 646 vp = nd.ni_vp; 647 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 648 NDFREE(&nd, NDF_ONLY_PNBUF); 649 if (nd.ni_dvp == vp) 650 vrele(nd.ni_dvp); 651 else 652 vput(nd.ni_dvp); 653 if (vp != NULL) { 654 vrele(vp); 655 error = EADDRINUSE; 656 goto error; 657 } 658 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 659 if (error) 660 goto error; 661 goto restart; 662 } 663 VATTR_NULL(&vattr); 664 vattr.va_type = VSOCK; 665 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_pd->pd_cmask); 666 #ifdef MAC 667 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 668 &vattr); 669 #endif 670 if (error == 0) 671 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 672 NDFREE(&nd, NDF_ONLY_PNBUF); 673 if (error) { 674 VOP_VPUT_PAIR(nd.ni_dvp, NULL, true); 675 vn_finished_write(mp); 676 if (error == ERELOOKUP) 677 goto restart; 678 goto error; 679 } 680 vp = nd.ni_vp; 681 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 682 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 683 684 UNP_PCB_LOCK(unp); 685 VOP_UNP_BIND(vp, unp); 686 unp->unp_vnode = vp; 687 unp->unp_addr = soun; 688 unp->unp_flags &= ~UNP_BINDING; 689 UNP_PCB_UNLOCK(unp); 690 vref(vp); 691 VOP_VPUT_PAIR(nd.ni_dvp, &vp, true); 692 vn_finished_write(mp); 693 free(buf, M_TEMP); 694 return (0); 695 696 error: 697 UNP_PCB_LOCK(unp); 698 unp->unp_flags &= ~UNP_BINDING; 699 UNP_PCB_UNLOCK(unp); 700 free(buf, M_TEMP); 701 return (error); 702 } 703 704 static int 705 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 706 { 707 708 return (uipc_bindat(AT_FDCWD, so, nam, td)); 709 } 710 711 static int 712 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 713 { 714 int error; 715 716 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 717 error = unp_connect(so, nam, td); 718 return (error); 719 } 720 721 static int 722 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 723 struct thread *td) 724 { 725 int error; 726 727 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 728 error = unp_connectat(fd, so, nam, td); 729 return (error); 730 } 731 732 static void 733 uipc_close(struct socket *so) 734 { 735 struct unpcb *unp, *unp2; 736 struct vnode *vp = NULL; 737 struct mtx *vplock; 738 739 unp = sotounpcb(so); 740 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 741 742 vplock = NULL; 743 if ((vp = unp->unp_vnode) != NULL) { 744 vplock = mtx_pool_find(mtxpool_sleep, vp); 745 mtx_lock(vplock); 746 } 747 UNP_PCB_LOCK(unp); 748 if (vp && unp->unp_vnode == NULL) { 749 mtx_unlock(vplock); 750 vp = NULL; 751 } 752 if (vp != NULL) { 753 VOP_UNP_DETACH(vp); 754 unp->unp_vnode = NULL; 755 } 756 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 757 unp_disconnect(unp, unp2); 758 else 759 UNP_PCB_UNLOCK(unp); 760 if (vp) { 761 mtx_unlock(vplock); 762 vrele(vp); 763 } 764 } 765 766 static int 767 uipc_connect2(struct socket *so1, struct socket *so2) 768 { 769 struct unpcb *unp, *unp2; 770 int error; 771 772 unp = so1->so_pcb; 773 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 774 unp2 = so2->so_pcb; 775 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 776 unp_pcb_lock_pair(unp, unp2); 777 error = unp_connect2(so1, so2, PRU_CONNECT2); 778 unp_pcb_unlock_pair(unp, unp2); 779 return (error); 780 } 781 782 static void 783 uipc_detach(struct socket *so) 784 { 785 struct unpcb *unp, *unp2; 786 struct mtx *vplock; 787 struct vnode *vp; 788 int local_unp_rights; 789 790 unp = sotounpcb(so); 791 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 792 793 vp = NULL; 794 vplock = NULL; 795 796 SOCK_LOCK(so); 797 if (!SOLISTENING(so)) { 798 /* 799 * Once the socket is removed from the global lists, 800 * uipc_ready() will not be able to locate its socket buffer, so 801 * clear the buffer now. At this point internalized rights have 802 * already been disposed of. 803 */ 804 sbrelease(&so->so_rcv, so); 805 } 806 SOCK_UNLOCK(so); 807 808 UNP_LINK_WLOCK(); 809 LIST_REMOVE(unp, unp_link); 810 if (unp->unp_gcflag & UNPGC_DEAD) 811 LIST_REMOVE(unp, unp_dead); 812 unp->unp_gencnt = ++unp_gencnt; 813 --unp_count; 814 UNP_LINK_WUNLOCK(); 815 816 UNP_PCB_UNLOCK_ASSERT(unp); 817 restart: 818 if ((vp = unp->unp_vnode) != NULL) { 819 vplock = mtx_pool_find(mtxpool_sleep, vp); 820 mtx_lock(vplock); 821 } 822 UNP_PCB_LOCK(unp); 823 if (unp->unp_vnode != vp && unp->unp_vnode != NULL) { 824 if (vplock) 825 mtx_unlock(vplock); 826 UNP_PCB_UNLOCK(unp); 827 goto restart; 828 } 829 if ((vp = unp->unp_vnode) != NULL) { 830 VOP_UNP_DETACH(vp); 831 unp->unp_vnode = NULL; 832 } 833 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 834 unp_disconnect(unp, unp2); 835 else 836 UNP_PCB_UNLOCK(unp); 837 838 UNP_REF_LIST_LOCK(); 839 while (!LIST_EMPTY(&unp->unp_refs)) { 840 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 841 842 unp_pcb_hold(ref); 843 UNP_REF_LIST_UNLOCK(); 844 845 MPASS(ref != unp); 846 UNP_PCB_UNLOCK_ASSERT(ref); 847 unp_drop(ref); 848 UNP_REF_LIST_LOCK(); 849 } 850 UNP_REF_LIST_UNLOCK(); 851 852 UNP_PCB_LOCK(unp); 853 local_unp_rights = unp_rights; 854 unp->unp_socket->so_pcb = NULL; 855 unp->unp_socket = NULL; 856 free(unp->unp_addr, M_SONAME); 857 unp->unp_addr = NULL; 858 if (!unp_pcb_rele(unp)) 859 UNP_PCB_UNLOCK(unp); 860 if (vp) { 861 mtx_unlock(vplock); 862 vrele(vp); 863 } 864 if (local_unp_rights) 865 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 866 } 867 868 static int 869 uipc_disconnect(struct socket *so) 870 { 871 struct unpcb *unp, *unp2; 872 873 unp = sotounpcb(so); 874 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 875 876 UNP_PCB_LOCK(unp); 877 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 878 unp_disconnect(unp, unp2); 879 else 880 UNP_PCB_UNLOCK(unp); 881 return (0); 882 } 883 884 static int 885 uipc_listen(struct socket *so, int backlog, struct thread *td) 886 { 887 struct unpcb *unp; 888 int error; 889 890 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 891 return (EOPNOTSUPP); 892 893 /* 894 * Synchronize with concurrent connection attempts. 895 */ 896 error = 0; 897 unp = sotounpcb(so); 898 UNP_PCB_LOCK(unp); 899 if (unp->unp_conn != NULL || (unp->unp_flags & UNP_CONNECTING) != 0) 900 error = EINVAL; 901 else if (unp->unp_vnode == NULL) 902 error = EDESTADDRREQ; 903 if (error != 0) { 904 UNP_PCB_UNLOCK(unp); 905 return (error); 906 } 907 908 SOCK_LOCK(so); 909 error = solisten_proto_check(so); 910 if (error == 0) { 911 cru2xt(td, &unp->unp_peercred); 912 solisten_proto(so, backlog); 913 } 914 SOCK_UNLOCK(so); 915 UNP_PCB_UNLOCK(unp); 916 return (error); 917 } 918 919 static int 920 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 921 { 922 struct unpcb *unp, *unp2; 923 const struct sockaddr *sa; 924 925 unp = sotounpcb(so); 926 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 927 928 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 929 UNP_LINK_RLOCK(); 930 /* 931 * XXX: It seems that this test always fails even when connection is 932 * established. So, this else clause is added as workaround to 933 * return PF_LOCAL sockaddr. 934 */ 935 unp2 = unp->unp_conn; 936 if (unp2 != NULL) { 937 UNP_PCB_LOCK(unp2); 938 if (unp2->unp_addr != NULL) 939 sa = (struct sockaddr *) unp2->unp_addr; 940 else 941 sa = &sun_noname; 942 bcopy(sa, *nam, sa->sa_len); 943 UNP_PCB_UNLOCK(unp2); 944 } else { 945 sa = &sun_noname; 946 bcopy(sa, *nam, sa->sa_len); 947 } 948 UNP_LINK_RUNLOCK(); 949 return (0); 950 } 951 952 static int 953 uipc_rcvd(struct socket *so, int flags) 954 { 955 struct unpcb *unp, *unp2; 956 struct socket *so2; 957 u_int mbcnt, sbcc; 958 959 unp = sotounpcb(so); 960 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 961 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 962 ("%s: socktype %d", __func__, so->so_type)); 963 964 /* 965 * Adjust backpressure on sender and wakeup any waiting to write. 966 * 967 * The unp lock is acquired to maintain the validity of the unp_conn 968 * pointer; no lock on unp2 is required as unp2->unp_socket will be 969 * static as long as we don't permit unp2 to disconnect from unp, 970 * which is prevented by the lock on unp. We cache values from 971 * so_rcv to avoid holding the so_rcv lock over the entire 972 * transaction on the remote so_snd. 973 */ 974 SOCKBUF_LOCK(&so->so_rcv); 975 mbcnt = so->so_rcv.sb_mbcnt; 976 sbcc = sbavail(&so->so_rcv); 977 SOCKBUF_UNLOCK(&so->so_rcv); 978 /* 979 * There is a benign race condition at this point. If we're planning to 980 * clear SB_STOP, but uipc_send is called on the connected socket at 981 * this instant, it might add data to the sockbuf and set SB_STOP. Then 982 * we would erroneously clear SB_STOP below, even though the sockbuf is 983 * full. The race is benign because the only ill effect is to allow the 984 * sockbuf to exceed its size limit, and the size limits are not 985 * strictly guaranteed anyway. 986 */ 987 UNP_PCB_LOCK(unp); 988 unp2 = unp->unp_conn; 989 if (unp2 == NULL) { 990 UNP_PCB_UNLOCK(unp); 991 return (0); 992 } 993 so2 = unp2->unp_socket; 994 SOCKBUF_LOCK(&so2->so_snd); 995 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 996 so2->so_snd.sb_flags &= ~SB_STOP; 997 sowwakeup_locked(so2); 998 UNP_PCB_UNLOCK(unp); 999 return (0); 1000 } 1001 1002 static int 1003 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 1004 struct mbuf *control, struct thread *td) 1005 { 1006 struct unpcb *unp, *unp2; 1007 struct socket *so2; 1008 u_int mbcnt, sbcc; 1009 int freed, error; 1010 1011 unp = sotounpcb(so); 1012 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 1013 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 1014 so->so_type == SOCK_SEQPACKET, 1015 ("%s: socktype %d", __func__, so->so_type)); 1016 1017 freed = error = 0; 1018 if (flags & PRUS_OOB) { 1019 error = EOPNOTSUPP; 1020 goto release; 1021 } 1022 if (control != NULL && (error = unp_internalize(&control, td))) 1023 goto release; 1024 1025 unp2 = NULL; 1026 switch (so->so_type) { 1027 case SOCK_DGRAM: 1028 { 1029 const struct sockaddr *from; 1030 1031 if (nam != NULL) { 1032 error = unp_connect(so, nam, td); 1033 if (error != 0) 1034 break; 1035 } 1036 UNP_PCB_LOCK(unp); 1037 1038 /* 1039 * Because connect() and send() are non-atomic in a sendto() 1040 * with a target address, it's possible that the socket will 1041 * have disconnected before the send() can run. In that case 1042 * return the slightly counter-intuitive but otherwise 1043 * correct error that the socket is not connected. 1044 */ 1045 unp2 = unp_pcb_lock_peer(unp); 1046 if (unp2 == NULL) { 1047 UNP_PCB_UNLOCK(unp); 1048 error = ENOTCONN; 1049 break; 1050 } 1051 1052 if (unp2->unp_flags & UNP_WANTCRED_MASK) 1053 control = unp_addsockcred(td, control, 1054 unp2->unp_flags); 1055 if (unp->unp_addr != NULL) 1056 from = (struct sockaddr *)unp->unp_addr; 1057 else 1058 from = &sun_noname; 1059 so2 = unp2->unp_socket; 1060 SOCKBUF_LOCK(&so2->so_rcv); 1061 if (sbappendaddr_locked(&so2->so_rcv, from, m, 1062 control)) { 1063 sorwakeup_locked(so2); 1064 m = NULL; 1065 control = NULL; 1066 } else { 1067 soroverflow_locked(so2); 1068 error = ENOBUFS; 1069 } 1070 if (nam != NULL) 1071 unp_disconnect(unp, unp2); 1072 else 1073 unp_pcb_unlock_pair(unp, unp2); 1074 break; 1075 } 1076 1077 case SOCK_SEQPACKET: 1078 case SOCK_STREAM: 1079 if ((so->so_state & SS_ISCONNECTED) == 0) { 1080 if (nam != NULL) { 1081 error = unp_connect(so, nam, td); 1082 if (error != 0) 1083 break; 1084 } else { 1085 error = ENOTCONN; 1086 break; 1087 } 1088 } 1089 1090 UNP_PCB_LOCK(unp); 1091 if ((unp2 = unp_pcb_lock_peer(unp)) == NULL) { 1092 UNP_PCB_UNLOCK(unp); 1093 error = ENOTCONN; 1094 break; 1095 } else if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 1096 unp_pcb_unlock_pair(unp, unp2); 1097 error = EPIPE; 1098 break; 1099 } 1100 UNP_PCB_UNLOCK(unp); 1101 if ((so2 = unp2->unp_socket) == NULL) { 1102 UNP_PCB_UNLOCK(unp2); 1103 error = ENOTCONN; 1104 break; 1105 } 1106 SOCKBUF_LOCK(&so2->so_rcv); 1107 if (unp2->unp_flags & UNP_WANTCRED_MASK) { 1108 /* 1109 * Credentials are passed only once on SOCK_STREAM and 1110 * SOCK_SEQPACKET (LOCAL_CREDS => WANTCRED_ONESHOT), or 1111 * forever (LOCAL_CREDS_PERSISTENT => WANTCRED_ALWAYS). 1112 */ 1113 control = unp_addsockcred(td, control, unp2->unp_flags); 1114 unp2->unp_flags &= ~UNP_WANTCRED_ONESHOT; 1115 } 1116 1117 /* 1118 * Send to paired receive port and wake up readers. Don't 1119 * check for space available in the receive buffer if we're 1120 * attaching ancillary data; Unix domain sockets only check 1121 * for space in the sending sockbuf, and that check is 1122 * performed one level up the stack. At that level we cannot 1123 * precisely account for the amount of buffer space used 1124 * (e.g., because control messages are not yet internalized). 1125 */ 1126 switch (so->so_type) { 1127 case SOCK_STREAM: 1128 if (control != NULL) { 1129 sbappendcontrol_locked(&so2->so_rcv, m, 1130 control, flags); 1131 control = NULL; 1132 } else 1133 sbappend_locked(&so2->so_rcv, m, flags); 1134 break; 1135 1136 case SOCK_SEQPACKET: 1137 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 1138 &sun_noname, m, control)) 1139 control = NULL; 1140 break; 1141 } 1142 1143 mbcnt = so2->so_rcv.sb_mbcnt; 1144 sbcc = sbavail(&so2->so_rcv); 1145 if (sbcc) 1146 sorwakeup_locked(so2); 1147 else 1148 SOCKBUF_UNLOCK(&so2->so_rcv); 1149 1150 /* 1151 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1152 * it would be possible for uipc_rcvd to be called at this 1153 * point, drain the receiving sockbuf, clear SB_STOP, and then 1154 * we would set SB_STOP below. That could lead to an empty 1155 * sockbuf having SB_STOP set 1156 */ 1157 SOCKBUF_LOCK(&so->so_snd); 1158 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1159 so->so_snd.sb_flags |= SB_STOP; 1160 SOCKBUF_UNLOCK(&so->so_snd); 1161 UNP_PCB_UNLOCK(unp2); 1162 m = NULL; 1163 break; 1164 } 1165 1166 /* 1167 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1168 */ 1169 if (flags & PRUS_EOF) { 1170 UNP_PCB_LOCK(unp); 1171 socantsendmore(so); 1172 unp_shutdown(unp); 1173 UNP_PCB_UNLOCK(unp); 1174 } 1175 if (control != NULL && error != 0) 1176 unp_dispose_mbuf(control); 1177 1178 release: 1179 if (control != NULL) 1180 m_freem(control); 1181 /* 1182 * In case of PRUS_NOTREADY, uipc_ready() is responsible 1183 * for freeing memory. 1184 */ 1185 if (m != NULL && (flags & PRUS_NOTREADY) == 0) 1186 m_freem(m); 1187 return (error); 1188 } 1189 1190 static bool 1191 uipc_ready_scan(struct socket *so, struct mbuf *m, int count, int *errorp) 1192 { 1193 struct mbuf *mb, *n; 1194 struct sockbuf *sb; 1195 1196 SOCK_LOCK(so); 1197 if (SOLISTENING(so)) { 1198 SOCK_UNLOCK(so); 1199 return (false); 1200 } 1201 mb = NULL; 1202 sb = &so->so_rcv; 1203 SOCKBUF_LOCK(sb); 1204 if (sb->sb_fnrdy != NULL) { 1205 for (mb = sb->sb_mb, n = mb->m_nextpkt; mb != NULL;) { 1206 if (mb == m) { 1207 *errorp = sbready(sb, m, count); 1208 break; 1209 } 1210 mb = mb->m_next; 1211 if (mb == NULL) { 1212 mb = n; 1213 if (mb != NULL) 1214 n = mb->m_nextpkt; 1215 } 1216 } 1217 } 1218 SOCKBUF_UNLOCK(sb); 1219 SOCK_UNLOCK(so); 1220 return (mb != NULL); 1221 } 1222 1223 static int 1224 uipc_ready(struct socket *so, struct mbuf *m, int count) 1225 { 1226 struct unpcb *unp, *unp2; 1227 struct socket *so2; 1228 int error, i; 1229 1230 unp = sotounpcb(so); 1231 1232 KASSERT(so->so_type == SOCK_STREAM, 1233 ("%s: unexpected socket type for %p", __func__, so)); 1234 1235 UNP_PCB_LOCK(unp); 1236 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) { 1237 UNP_PCB_UNLOCK(unp); 1238 so2 = unp2->unp_socket; 1239 SOCKBUF_LOCK(&so2->so_rcv); 1240 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1241 sorwakeup_locked(so2); 1242 else 1243 SOCKBUF_UNLOCK(&so2->so_rcv); 1244 UNP_PCB_UNLOCK(unp2); 1245 return (error); 1246 } 1247 UNP_PCB_UNLOCK(unp); 1248 1249 /* 1250 * The receiving socket has been disconnected, but may still be valid. 1251 * In this case, the now-ready mbufs are still present in its socket 1252 * buffer, so perform an exhaustive search before giving up and freeing 1253 * the mbufs. 1254 */ 1255 UNP_LINK_RLOCK(); 1256 LIST_FOREACH(unp, &unp_shead, unp_link) { 1257 if (uipc_ready_scan(unp->unp_socket, m, count, &error)) 1258 break; 1259 } 1260 UNP_LINK_RUNLOCK(); 1261 1262 if (unp == NULL) { 1263 for (i = 0; i < count; i++) 1264 m = m_free(m); 1265 error = ECONNRESET; 1266 } 1267 return (error); 1268 } 1269 1270 static int 1271 uipc_sense(struct socket *so, struct stat *sb) 1272 { 1273 struct unpcb *unp; 1274 1275 unp = sotounpcb(so); 1276 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1277 1278 sb->st_blksize = so->so_snd.sb_hiwat; 1279 sb->st_dev = NODEV; 1280 sb->st_ino = unp->unp_ino; 1281 return (0); 1282 } 1283 1284 static int 1285 uipc_shutdown(struct socket *so) 1286 { 1287 struct unpcb *unp; 1288 1289 unp = sotounpcb(so); 1290 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1291 1292 UNP_PCB_LOCK(unp); 1293 socantsendmore(so); 1294 unp_shutdown(unp); 1295 UNP_PCB_UNLOCK(unp); 1296 return (0); 1297 } 1298 1299 static int 1300 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1301 { 1302 struct unpcb *unp; 1303 const struct sockaddr *sa; 1304 1305 unp = sotounpcb(so); 1306 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1307 1308 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1309 UNP_PCB_LOCK(unp); 1310 if (unp->unp_addr != NULL) 1311 sa = (struct sockaddr *) unp->unp_addr; 1312 else 1313 sa = &sun_noname; 1314 bcopy(sa, *nam, sa->sa_len); 1315 UNP_PCB_UNLOCK(unp); 1316 return (0); 1317 } 1318 1319 static struct pr_usrreqs uipc_usrreqs_dgram = { 1320 .pru_abort = uipc_abort, 1321 .pru_accept = uipc_accept, 1322 .pru_attach = uipc_attach, 1323 .pru_bind = uipc_bind, 1324 .pru_bindat = uipc_bindat, 1325 .pru_connect = uipc_connect, 1326 .pru_connectat = uipc_connectat, 1327 .pru_connect2 = uipc_connect2, 1328 .pru_detach = uipc_detach, 1329 .pru_disconnect = uipc_disconnect, 1330 .pru_listen = uipc_listen, 1331 .pru_peeraddr = uipc_peeraddr, 1332 .pru_rcvd = uipc_rcvd, 1333 .pru_send = uipc_send, 1334 .pru_sense = uipc_sense, 1335 .pru_shutdown = uipc_shutdown, 1336 .pru_sockaddr = uipc_sockaddr, 1337 .pru_soreceive = soreceive_dgram, 1338 .pru_close = uipc_close, 1339 }; 1340 1341 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1342 .pru_abort = uipc_abort, 1343 .pru_accept = uipc_accept, 1344 .pru_attach = uipc_attach, 1345 .pru_bind = uipc_bind, 1346 .pru_bindat = uipc_bindat, 1347 .pru_connect = uipc_connect, 1348 .pru_connectat = uipc_connectat, 1349 .pru_connect2 = uipc_connect2, 1350 .pru_detach = uipc_detach, 1351 .pru_disconnect = uipc_disconnect, 1352 .pru_listen = uipc_listen, 1353 .pru_peeraddr = uipc_peeraddr, 1354 .pru_rcvd = uipc_rcvd, 1355 .pru_send = uipc_send, 1356 .pru_sense = uipc_sense, 1357 .pru_shutdown = uipc_shutdown, 1358 .pru_sockaddr = uipc_sockaddr, 1359 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1360 .pru_close = uipc_close, 1361 }; 1362 1363 static struct pr_usrreqs uipc_usrreqs_stream = { 1364 .pru_abort = uipc_abort, 1365 .pru_accept = uipc_accept, 1366 .pru_attach = uipc_attach, 1367 .pru_bind = uipc_bind, 1368 .pru_bindat = uipc_bindat, 1369 .pru_connect = uipc_connect, 1370 .pru_connectat = uipc_connectat, 1371 .pru_connect2 = uipc_connect2, 1372 .pru_detach = uipc_detach, 1373 .pru_disconnect = uipc_disconnect, 1374 .pru_listen = uipc_listen, 1375 .pru_peeraddr = uipc_peeraddr, 1376 .pru_rcvd = uipc_rcvd, 1377 .pru_send = uipc_send, 1378 .pru_ready = uipc_ready, 1379 .pru_sense = uipc_sense, 1380 .pru_shutdown = uipc_shutdown, 1381 .pru_sockaddr = uipc_sockaddr, 1382 .pru_soreceive = soreceive_generic, 1383 .pru_close = uipc_close, 1384 }; 1385 1386 static int 1387 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1388 { 1389 struct unpcb *unp; 1390 struct xucred xu; 1391 int error, optval; 1392 1393 if (sopt->sopt_level != SOL_LOCAL) 1394 return (EINVAL); 1395 1396 unp = sotounpcb(so); 1397 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1398 error = 0; 1399 switch (sopt->sopt_dir) { 1400 case SOPT_GET: 1401 switch (sopt->sopt_name) { 1402 case LOCAL_PEERCRED: 1403 UNP_PCB_LOCK(unp); 1404 if (unp->unp_flags & UNP_HAVEPC) 1405 xu = unp->unp_peercred; 1406 else { 1407 if (so->so_type == SOCK_STREAM) 1408 error = ENOTCONN; 1409 else 1410 error = EINVAL; 1411 } 1412 UNP_PCB_UNLOCK(unp); 1413 if (error == 0) 1414 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1415 break; 1416 1417 case LOCAL_CREDS: 1418 /* Unlocked read. */ 1419 optval = unp->unp_flags & UNP_WANTCRED_ONESHOT ? 1 : 0; 1420 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1421 break; 1422 1423 case LOCAL_CREDS_PERSISTENT: 1424 /* Unlocked read. */ 1425 optval = unp->unp_flags & UNP_WANTCRED_ALWAYS ? 1 : 0; 1426 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1427 break; 1428 1429 case LOCAL_CONNWAIT: 1430 /* Unlocked read. */ 1431 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1432 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1433 break; 1434 1435 default: 1436 error = EOPNOTSUPP; 1437 break; 1438 } 1439 break; 1440 1441 case SOPT_SET: 1442 switch (sopt->sopt_name) { 1443 case LOCAL_CREDS: 1444 case LOCAL_CREDS_PERSISTENT: 1445 case LOCAL_CONNWAIT: 1446 error = sooptcopyin(sopt, &optval, sizeof(optval), 1447 sizeof(optval)); 1448 if (error) 1449 break; 1450 1451 #define OPTSET(bit, exclusive) do { \ 1452 UNP_PCB_LOCK(unp); \ 1453 if (optval) { \ 1454 if ((unp->unp_flags & (exclusive)) != 0) { \ 1455 UNP_PCB_UNLOCK(unp); \ 1456 error = EINVAL; \ 1457 break; \ 1458 } \ 1459 unp->unp_flags |= (bit); \ 1460 } else \ 1461 unp->unp_flags &= ~(bit); \ 1462 UNP_PCB_UNLOCK(unp); \ 1463 } while (0) 1464 1465 switch (sopt->sopt_name) { 1466 case LOCAL_CREDS: 1467 OPTSET(UNP_WANTCRED_ONESHOT, UNP_WANTCRED_ALWAYS); 1468 break; 1469 1470 case LOCAL_CREDS_PERSISTENT: 1471 OPTSET(UNP_WANTCRED_ALWAYS, UNP_WANTCRED_ONESHOT); 1472 break; 1473 1474 case LOCAL_CONNWAIT: 1475 OPTSET(UNP_CONNWAIT, 0); 1476 break; 1477 1478 default: 1479 break; 1480 } 1481 break; 1482 #undef OPTSET 1483 default: 1484 error = ENOPROTOOPT; 1485 break; 1486 } 1487 break; 1488 1489 default: 1490 error = EOPNOTSUPP; 1491 break; 1492 } 1493 return (error); 1494 } 1495 1496 static int 1497 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1498 { 1499 1500 return (unp_connectat(AT_FDCWD, so, nam, td)); 1501 } 1502 1503 static int 1504 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1505 struct thread *td) 1506 { 1507 struct mtx *vplock; 1508 struct sockaddr_un *soun; 1509 struct vnode *vp; 1510 struct socket *so2; 1511 struct unpcb *unp, *unp2, *unp3; 1512 struct nameidata nd; 1513 char buf[SOCK_MAXADDRLEN]; 1514 struct sockaddr *sa; 1515 cap_rights_t rights; 1516 int error, len; 1517 bool connreq; 1518 1519 if (nam->sa_family != AF_UNIX) 1520 return (EAFNOSUPPORT); 1521 if (nam->sa_len > sizeof(struct sockaddr_un)) 1522 return (EINVAL); 1523 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1524 if (len <= 0) 1525 return (EINVAL); 1526 soun = (struct sockaddr_un *)nam; 1527 bcopy(soun->sun_path, buf, len); 1528 buf[len] = 0; 1529 1530 error = 0; 1531 unp = sotounpcb(so); 1532 UNP_PCB_LOCK(unp); 1533 for (;;) { 1534 /* 1535 * Wait for connection state to stabilize. If a connection 1536 * already exists, give up. For datagram sockets, which permit 1537 * multiple consecutive connect(2) calls, upper layers are 1538 * responsible for disconnecting in advance of a subsequent 1539 * connect(2), but this is not synchronized with PCB connection 1540 * state. 1541 * 1542 * Also make sure that no threads are currently attempting to 1543 * lock the peer socket, to ensure that unp_conn cannot 1544 * transition between two valid sockets while locks are dropped. 1545 */ 1546 if (SOLISTENING(so)) 1547 error = EOPNOTSUPP; 1548 else if (unp->unp_conn != NULL) 1549 error = EISCONN; 1550 else if ((unp->unp_flags & UNP_CONNECTING) != 0) { 1551 error = EALREADY; 1552 } 1553 if (error != 0) { 1554 UNP_PCB_UNLOCK(unp); 1555 return (error); 1556 } 1557 if (unp->unp_pairbusy > 0) { 1558 unp->unp_flags |= UNP_WAITING; 1559 mtx_sleep(unp, UNP_PCB_LOCKPTR(unp), 0, "unpeer", 0); 1560 continue; 1561 } 1562 break; 1563 } 1564 unp->unp_flags |= UNP_CONNECTING; 1565 UNP_PCB_UNLOCK(unp); 1566 1567 connreq = (so->so_proto->pr_flags & PR_CONNREQUIRED) != 0; 1568 if (connreq) 1569 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1570 else 1571 sa = NULL; 1572 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1573 UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_CONNECTAT), 1574 td); 1575 error = namei(&nd); 1576 if (error) 1577 vp = NULL; 1578 else 1579 vp = nd.ni_vp; 1580 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1581 NDFREE_NOTHING(&nd); 1582 if (error) 1583 goto bad; 1584 1585 if (vp->v_type != VSOCK) { 1586 error = ENOTSOCK; 1587 goto bad; 1588 } 1589 #ifdef MAC 1590 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1591 if (error) 1592 goto bad; 1593 #endif 1594 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1595 if (error) 1596 goto bad; 1597 1598 unp = sotounpcb(so); 1599 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1600 1601 vplock = mtx_pool_find(mtxpool_sleep, vp); 1602 mtx_lock(vplock); 1603 VOP_UNP_CONNECT(vp, &unp2); 1604 if (unp2 == NULL) { 1605 error = ECONNREFUSED; 1606 goto bad2; 1607 } 1608 so2 = unp2->unp_socket; 1609 if (so->so_type != so2->so_type) { 1610 error = EPROTOTYPE; 1611 goto bad2; 1612 } 1613 if (connreq) { 1614 if (SOLISTENING(so2)) { 1615 CURVNET_SET(so2->so_vnet); 1616 so2 = sonewconn(so2, 0); 1617 CURVNET_RESTORE(); 1618 } else 1619 so2 = NULL; 1620 if (so2 == NULL) { 1621 error = ECONNREFUSED; 1622 goto bad2; 1623 } 1624 unp3 = sotounpcb(so2); 1625 unp_pcb_lock_pair(unp2, unp3); 1626 if (unp2->unp_addr != NULL) { 1627 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1628 unp3->unp_addr = (struct sockaddr_un *) sa; 1629 sa = NULL; 1630 } 1631 1632 unp_copy_peercred(td, unp3, unp, unp2); 1633 1634 UNP_PCB_UNLOCK(unp2); 1635 unp2 = unp3; 1636 1637 /* 1638 * It is safe to block on the PCB lock here since unp2 is 1639 * nascent and cannot be connected to any other sockets. 1640 */ 1641 UNP_PCB_LOCK(unp); 1642 #ifdef MAC 1643 mac_socketpeer_set_from_socket(so, so2); 1644 mac_socketpeer_set_from_socket(so2, so); 1645 #endif 1646 } else { 1647 unp_pcb_lock_pair(unp, unp2); 1648 } 1649 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1650 sotounpcb(so2) == unp2, 1651 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1652 error = unp_connect2(so, so2, PRU_CONNECT); 1653 unp_pcb_unlock_pair(unp, unp2); 1654 bad2: 1655 mtx_unlock(vplock); 1656 bad: 1657 if (vp != NULL) { 1658 vput(vp); 1659 } 1660 free(sa, M_SONAME); 1661 UNP_PCB_LOCK(unp); 1662 KASSERT((unp->unp_flags & UNP_CONNECTING) != 0, 1663 ("%s: unp %p has UNP_CONNECTING clear", __func__, unp)); 1664 unp->unp_flags &= ~UNP_CONNECTING; 1665 UNP_PCB_UNLOCK(unp); 1666 return (error); 1667 } 1668 1669 /* 1670 * Set socket peer credentials at connection time. 1671 * 1672 * The client's PCB credentials are copied from its process structure. The 1673 * server's PCB credentials are copied from the socket on which it called 1674 * listen(2). uipc_listen cached that process's credentials at the time. 1675 */ 1676 void 1677 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 1678 struct unpcb *server_unp, struct unpcb *listen_unp) 1679 { 1680 cru2xt(td, &client_unp->unp_peercred); 1681 client_unp->unp_flags |= UNP_HAVEPC; 1682 1683 memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred, 1684 sizeof(server_unp->unp_peercred)); 1685 server_unp->unp_flags |= UNP_HAVEPC; 1686 client_unp->unp_flags |= (listen_unp->unp_flags & UNP_WANTCRED_MASK); 1687 } 1688 1689 static int 1690 unp_connect2(struct socket *so, struct socket *so2, int req) 1691 { 1692 struct unpcb *unp; 1693 struct unpcb *unp2; 1694 1695 unp = sotounpcb(so); 1696 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1697 unp2 = sotounpcb(so2); 1698 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1699 1700 UNP_PCB_LOCK_ASSERT(unp); 1701 UNP_PCB_LOCK_ASSERT(unp2); 1702 KASSERT(unp->unp_conn == NULL, 1703 ("%s: socket %p is already connected", __func__, unp)); 1704 1705 if (so2->so_type != so->so_type) 1706 return (EPROTOTYPE); 1707 unp->unp_conn = unp2; 1708 unp_pcb_hold(unp2); 1709 unp_pcb_hold(unp); 1710 switch (so->so_type) { 1711 case SOCK_DGRAM: 1712 UNP_REF_LIST_LOCK(); 1713 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1714 UNP_REF_LIST_UNLOCK(); 1715 soisconnected(so); 1716 break; 1717 1718 case SOCK_STREAM: 1719 case SOCK_SEQPACKET: 1720 KASSERT(unp2->unp_conn == NULL, 1721 ("%s: socket %p is already connected", __func__, unp2)); 1722 unp2->unp_conn = unp; 1723 if (req == PRU_CONNECT && 1724 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1725 soisconnecting(so); 1726 else 1727 soisconnected(so); 1728 soisconnected(so2); 1729 break; 1730 1731 default: 1732 panic("unp_connect2"); 1733 } 1734 return (0); 1735 } 1736 1737 static void 1738 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1739 { 1740 struct socket *so, *so2; 1741 #ifdef INVARIANTS 1742 struct unpcb *unptmp; 1743 #endif 1744 1745 UNP_PCB_LOCK_ASSERT(unp); 1746 UNP_PCB_LOCK_ASSERT(unp2); 1747 KASSERT(unp->unp_conn == unp2, 1748 ("%s: unpcb %p is not connected to %p", __func__, unp, unp2)); 1749 1750 unp->unp_conn = NULL; 1751 so = unp->unp_socket; 1752 so2 = unp2->unp_socket; 1753 switch (unp->unp_socket->so_type) { 1754 case SOCK_DGRAM: 1755 UNP_REF_LIST_LOCK(); 1756 #ifdef INVARIANTS 1757 LIST_FOREACH(unptmp, &unp2->unp_refs, unp_reflink) { 1758 if (unptmp == unp) 1759 break; 1760 } 1761 KASSERT(unptmp != NULL, 1762 ("%s: %p not found in reflist of %p", __func__, unp, unp2)); 1763 #endif 1764 LIST_REMOVE(unp, unp_reflink); 1765 UNP_REF_LIST_UNLOCK(); 1766 if (so) { 1767 SOCK_LOCK(so); 1768 so->so_state &= ~SS_ISCONNECTED; 1769 SOCK_UNLOCK(so); 1770 } 1771 break; 1772 1773 case SOCK_STREAM: 1774 case SOCK_SEQPACKET: 1775 if (so) 1776 soisdisconnected(so); 1777 MPASS(unp2->unp_conn == unp); 1778 unp2->unp_conn = NULL; 1779 if (so2) 1780 soisdisconnected(so2); 1781 break; 1782 } 1783 1784 if (unp == unp2) { 1785 unp_pcb_rele_notlast(unp); 1786 if (!unp_pcb_rele(unp)) 1787 UNP_PCB_UNLOCK(unp); 1788 } else { 1789 if (!unp_pcb_rele(unp)) 1790 UNP_PCB_UNLOCK(unp); 1791 if (!unp_pcb_rele(unp2)) 1792 UNP_PCB_UNLOCK(unp2); 1793 } 1794 } 1795 1796 /* 1797 * unp_pcblist() walks the global list of struct unpcb's to generate a 1798 * pointer list, bumping the refcount on each unpcb. It then copies them out 1799 * sequentially, validating the generation number on each to see if it has 1800 * been detached. All of this is necessary because copyout() may sleep on 1801 * disk I/O. 1802 */ 1803 static int 1804 unp_pcblist(SYSCTL_HANDLER_ARGS) 1805 { 1806 struct unpcb *unp, **unp_list; 1807 unp_gen_t gencnt; 1808 struct xunpgen *xug; 1809 struct unp_head *head; 1810 struct xunpcb *xu; 1811 u_int i; 1812 int error, n; 1813 1814 switch ((intptr_t)arg1) { 1815 case SOCK_STREAM: 1816 head = &unp_shead; 1817 break; 1818 1819 case SOCK_DGRAM: 1820 head = &unp_dhead; 1821 break; 1822 1823 case SOCK_SEQPACKET: 1824 head = &unp_sphead; 1825 break; 1826 1827 default: 1828 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1829 } 1830 1831 /* 1832 * The process of preparing the PCB list is too time-consuming and 1833 * resource-intensive to repeat twice on every request. 1834 */ 1835 if (req->oldptr == NULL) { 1836 n = unp_count; 1837 req->oldidx = 2 * (sizeof *xug) 1838 + (n + n/8) * sizeof(struct xunpcb); 1839 return (0); 1840 } 1841 1842 if (req->newptr != NULL) 1843 return (EPERM); 1844 1845 /* 1846 * OK, now we're committed to doing something. 1847 */ 1848 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK | M_ZERO); 1849 UNP_LINK_RLOCK(); 1850 gencnt = unp_gencnt; 1851 n = unp_count; 1852 UNP_LINK_RUNLOCK(); 1853 1854 xug->xug_len = sizeof *xug; 1855 xug->xug_count = n; 1856 xug->xug_gen = gencnt; 1857 xug->xug_sogen = so_gencnt; 1858 error = SYSCTL_OUT(req, xug, sizeof *xug); 1859 if (error) { 1860 free(xug, M_TEMP); 1861 return (error); 1862 } 1863 1864 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1865 1866 UNP_LINK_RLOCK(); 1867 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1868 unp = LIST_NEXT(unp, unp_link)) { 1869 UNP_PCB_LOCK(unp); 1870 if (unp->unp_gencnt <= gencnt) { 1871 if (cr_cansee(req->td->td_ucred, 1872 unp->unp_socket->so_cred)) { 1873 UNP_PCB_UNLOCK(unp); 1874 continue; 1875 } 1876 unp_list[i++] = unp; 1877 unp_pcb_hold(unp); 1878 } 1879 UNP_PCB_UNLOCK(unp); 1880 } 1881 UNP_LINK_RUNLOCK(); 1882 n = i; /* In case we lost some during malloc. */ 1883 1884 error = 0; 1885 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1886 for (i = 0; i < n; i++) { 1887 unp = unp_list[i]; 1888 UNP_PCB_LOCK(unp); 1889 if (unp_pcb_rele(unp)) 1890 continue; 1891 1892 if (unp->unp_gencnt <= gencnt) { 1893 xu->xu_len = sizeof *xu; 1894 xu->xu_unpp = (uintptr_t)unp; 1895 /* 1896 * XXX - need more locking here to protect against 1897 * connect/disconnect races for SMP. 1898 */ 1899 if (unp->unp_addr != NULL) 1900 bcopy(unp->unp_addr, &xu->xu_addr, 1901 unp->unp_addr->sun_len); 1902 else 1903 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1904 if (unp->unp_conn != NULL && 1905 unp->unp_conn->unp_addr != NULL) 1906 bcopy(unp->unp_conn->unp_addr, 1907 &xu->xu_caddr, 1908 unp->unp_conn->unp_addr->sun_len); 1909 else 1910 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1911 xu->unp_vnode = (uintptr_t)unp->unp_vnode; 1912 xu->unp_conn = (uintptr_t)unp->unp_conn; 1913 xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs); 1914 xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink); 1915 xu->unp_gencnt = unp->unp_gencnt; 1916 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1917 UNP_PCB_UNLOCK(unp); 1918 error = SYSCTL_OUT(req, xu, sizeof *xu); 1919 } else { 1920 UNP_PCB_UNLOCK(unp); 1921 } 1922 } 1923 free(xu, M_TEMP); 1924 if (!error) { 1925 /* 1926 * Give the user an updated idea of our state. If the 1927 * generation differs from what we told her before, she knows 1928 * that something happened while we were processing this 1929 * request, and it might be necessary to retry. 1930 */ 1931 xug->xug_gen = unp_gencnt; 1932 xug->xug_sogen = so_gencnt; 1933 xug->xug_count = unp_count; 1934 error = SYSCTL_OUT(req, xug, sizeof *xug); 1935 } 1936 free(unp_list, M_TEMP); 1937 free(xug, M_TEMP); 1938 return (error); 1939 } 1940 1941 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, 1942 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1943 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1944 "List of active local datagram sockets"); 1945 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, 1946 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1947 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1948 "List of active local stream sockets"); 1949 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1950 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1951 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1952 "List of active local seqpacket sockets"); 1953 1954 static void 1955 unp_shutdown(struct unpcb *unp) 1956 { 1957 struct unpcb *unp2; 1958 struct socket *so; 1959 1960 UNP_PCB_LOCK_ASSERT(unp); 1961 1962 unp2 = unp->unp_conn; 1963 if ((unp->unp_socket->so_type == SOCK_STREAM || 1964 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1965 so = unp2->unp_socket; 1966 if (so != NULL) 1967 socantrcvmore(so); 1968 } 1969 } 1970 1971 static void 1972 unp_drop(struct unpcb *unp) 1973 { 1974 struct socket *so; 1975 struct unpcb *unp2; 1976 1977 /* 1978 * Regardless of whether the socket's peer dropped the connection 1979 * with this socket by aborting or disconnecting, POSIX requires 1980 * that ECONNRESET is returned. 1981 */ 1982 1983 UNP_PCB_LOCK(unp); 1984 so = unp->unp_socket; 1985 if (so) 1986 so->so_error = ECONNRESET; 1987 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) { 1988 /* Last reference dropped in unp_disconnect(). */ 1989 unp_pcb_rele_notlast(unp); 1990 unp_disconnect(unp, unp2); 1991 } else if (!unp_pcb_rele(unp)) { 1992 UNP_PCB_UNLOCK(unp); 1993 } 1994 } 1995 1996 static void 1997 unp_freerights(struct filedescent **fdep, int fdcount) 1998 { 1999 struct file *fp; 2000 int i; 2001 2002 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 2003 2004 for (i = 0; i < fdcount; i++) { 2005 fp = fdep[i]->fde_file; 2006 filecaps_free(&fdep[i]->fde_caps); 2007 unp_discard(fp); 2008 } 2009 free(fdep[0], M_FILECAPS); 2010 } 2011 2012 static int 2013 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 2014 { 2015 struct thread *td = curthread; /* XXX */ 2016 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2017 int i; 2018 int *fdp; 2019 struct filedesc *fdesc = td->td_proc->p_fd; 2020 struct filedescent **fdep; 2021 void *data; 2022 socklen_t clen = control->m_len, datalen; 2023 int error, newfds; 2024 u_int newlen; 2025 2026 UNP_LINK_UNLOCK_ASSERT(); 2027 2028 error = 0; 2029 if (controlp != NULL) /* controlp == NULL => free control messages */ 2030 *controlp = NULL; 2031 while (cm != NULL) { 2032 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 2033 error = EINVAL; 2034 break; 2035 } 2036 data = CMSG_DATA(cm); 2037 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2038 if (cm->cmsg_level == SOL_SOCKET 2039 && cm->cmsg_type == SCM_RIGHTS) { 2040 newfds = datalen / sizeof(*fdep); 2041 if (newfds == 0) 2042 goto next; 2043 fdep = data; 2044 2045 /* If we're not outputting the descriptors free them. */ 2046 if (error || controlp == NULL) { 2047 unp_freerights(fdep, newfds); 2048 goto next; 2049 } 2050 FILEDESC_XLOCK(fdesc); 2051 2052 /* 2053 * Now change each pointer to an fd in the global 2054 * table to an integer that is the index to the local 2055 * fd table entry that we set up to point to the 2056 * global one we are transferring. 2057 */ 2058 newlen = newfds * sizeof(int); 2059 *controlp = sbcreatecontrol(NULL, newlen, 2060 SCM_RIGHTS, SOL_SOCKET); 2061 if (*controlp == NULL) { 2062 FILEDESC_XUNLOCK(fdesc); 2063 error = E2BIG; 2064 unp_freerights(fdep, newfds); 2065 goto next; 2066 } 2067 2068 fdp = (int *) 2069 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2070 if (fdallocn(td, 0, fdp, newfds) != 0) { 2071 FILEDESC_XUNLOCK(fdesc); 2072 error = EMSGSIZE; 2073 unp_freerights(fdep, newfds); 2074 m_freem(*controlp); 2075 *controlp = NULL; 2076 goto next; 2077 } 2078 for (i = 0; i < newfds; i++, fdp++) { 2079 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2080 (flags & MSG_CMSG_CLOEXEC) != 0 ? O_CLOEXEC : 0, 2081 &fdep[i]->fde_caps); 2082 unp_externalize_fp(fdep[i]->fde_file); 2083 } 2084 2085 /* 2086 * The new type indicates that the mbuf data refers to 2087 * kernel resources that may need to be released before 2088 * the mbuf is freed. 2089 */ 2090 m_chtype(*controlp, MT_EXTCONTROL); 2091 FILEDESC_XUNLOCK(fdesc); 2092 free(fdep[0], M_FILECAPS); 2093 } else { 2094 /* We can just copy anything else across. */ 2095 if (error || controlp == NULL) 2096 goto next; 2097 *controlp = sbcreatecontrol(NULL, datalen, 2098 cm->cmsg_type, cm->cmsg_level); 2099 if (*controlp == NULL) { 2100 error = ENOBUFS; 2101 goto next; 2102 } 2103 bcopy(data, 2104 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2105 datalen); 2106 } 2107 controlp = &(*controlp)->m_next; 2108 2109 next: 2110 if (CMSG_SPACE(datalen) < clen) { 2111 clen -= CMSG_SPACE(datalen); 2112 cm = (struct cmsghdr *) 2113 ((caddr_t)cm + CMSG_SPACE(datalen)); 2114 } else { 2115 clen = 0; 2116 cm = NULL; 2117 } 2118 } 2119 2120 m_freem(control); 2121 return (error); 2122 } 2123 2124 static void 2125 unp_zone_change(void *tag) 2126 { 2127 2128 uma_zone_set_max(unp_zone, maxsockets); 2129 } 2130 2131 #ifdef INVARIANTS 2132 static void 2133 unp_zdtor(void *mem, int size __unused, void *arg __unused) 2134 { 2135 struct unpcb *unp; 2136 2137 unp = mem; 2138 2139 KASSERT(LIST_EMPTY(&unp->unp_refs), 2140 ("%s: unpcb %p has lingering refs", __func__, unp)); 2141 KASSERT(unp->unp_socket == NULL, 2142 ("%s: unpcb %p has socket backpointer", __func__, unp)); 2143 KASSERT(unp->unp_vnode == NULL, 2144 ("%s: unpcb %p has vnode references", __func__, unp)); 2145 KASSERT(unp->unp_conn == NULL, 2146 ("%s: unpcb %p is still connected", __func__, unp)); 2147 KASSERT(unp->unp_addr == NULL, 2148 ("%s: unpcb %p has leaked addr", __func__, unp)); 2149 } 2150 #endif 2151 2152 static void 2153 unp_init(void) 2154 { 2155 uma_dtor dtor; 2156 2157 #ifdef VIMAGE 2158 if (!IS_DEFAULT_VNET(curvnet)) 2159 return; 2160 #endif 2161 2162 #ifdef INVARIANTS 2163 dtor = unp_zdtor; 2164 #else 2165 dtor = NULL; 2166 #endif 2167 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, dtor, 2168 NULL, NULL, UMA_ALIGN_CACHE, 0); 2169 uma_zone_set_max(unp_zone, maxsockets); 2170 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2171 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2172 NULL, EVENTHANDLER_PRI_ANY); 2173 LIST_INIT(&unp_dhead); 2174 LIST_INIT(&unp_shead); 2175 LIST_INIT(&unp_sphead); 2176 SLIST_INIT(&unp_defers); 2177 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2178 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2179 UNP_LINK_LOCK_INIT(); 2180 UNP_DEFERRED_LOCK_INIT(); 2181 } 2182 2183 static void 2184 unp_internalize_cleanup_rights(struct mbuf *control) 2185 { 2186 struct cmsghdr *cp; 2187 struct mbuf *m; 2188 void *data; 2189 socklen_t datalen; 2190 2191 for (m = control; m != NULL; m = m->m_next) { 2192 cp = mtod(m, struct cmsghdr *); 2193 if (cp->cmsg_level != SOL_SOCKET || 2194 cp->cmsg_type != SCM_RIGHTS) 2195 continue; 2196 data = CMSG_DATA(cp); 2197 datalen = (caddr_t)cp + cp->cmsg_len - (caddr_t)data; 2198 unp_freerights(data, datalen / sizeof(struct filedesc *)); 2199 } 2200 } 2201 2202 static int 2203 unp_internalize(struct mbuf **controlp, struct thread *td) 2204 { 2205 struct mbuf *control, **initial_controlp; 2206 struct proc *p; 2207 struct filedesc *fdesc; 2208 struct bintime *bt; 2209 struct cmsghdr *cm; 2210 struct cmsgcred *cmcred; 2211 struct filedescent *fde, **fdep, *fdev; 2212 struct file *fp; 2213 struct timeval *tv; 2214 struct timespec *ts; 2215 void *data; 2216 socklen_t clen, datalen; 2217 int i, j, error, *fdp, oldfds; 2218 u_int newlen; 2219 2220 UNP_LINK_UNLOCK_ASSERT(); 2221 2222 p = td->td_proc; 2223 fdesc = p->p_fd; 2224 error = 0; 2225 control = *controlp; 2226 clen = control->m_len; 2227 *controlp = NULL; 2228 initial_controlp = controlp; 2229 for (cm = mtod(control, struct cmsghdr *); cm != NULL;) { 2230 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2231 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2232 error = EINVAL; 2233 goto out; 2234 } 2235 data = CMSG_DATA(cm); 2236 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2237 2238 switch (cm->cmsg_type) { 2239 /* 2240 * Fill in credential information. 2241 */ 2242 case SCM_CREDS: 2243 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2244 SCM_CREDS, SOL_SOCKET); 2245 if (*controlp == NULL) { 2246 error = ENOBUFS; 2247 goto out; 2248 } 2249 cmcred = (struct cmsgcred *) 2250 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2251 cmcred->cmcred_pid = p->p_pid; 2252 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2253 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2254 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2255 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2256 CMGROUP_MAX); 2257 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2258 cmcred->cmcred_groups[i] = 2259 td->td_ucred->cr_groups[i]; 2260 break; 2261 2262 case SCM_RIGHTS: 2263 oldfds = datalen / sizeof (int); 2264 if (oldfds == 0) 2265 break; 2266 /* 2267 * Check that all the FDs passed in refer to legal 2268 * files. If not, reject the entire operation. 2269 */ 2270 fdp = data; 2271 FILEDESC_SLOCK(fdesc); 2272 for (i = 0; i < oldfds; i++, fdp++) { 2273 fp = fget_locked(fdesc, *fdp); 2274 if (fp == NULL) { 2275 FILEDESC_SUNLOCK(fdesc); 2276 error = EBADF; 2277 goto out; 2278 } 2279 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2280 FILEDESC_SUNLOCK(fdesc); 2281 error = EOPNOTSUPP; 2282 goto out; 2283 } 2284 } 2285 2286 /* 2287 * Now replace the integer FDs with pointers to the 2288 * file structure and capability rights. 2289 */ 2290 newlen = oldfds * sizeof(fdep[0]); 2291 *controlp = sbcreatecontrol(NULL, newlen, 2292 SCM_RIGHTS, SOL_SOCKET); 2293 if (*controlp == NULL) { 2294 FILEDESC_SUNLOCK(fdesc); 2295 error = E2BIG; 2296 goto out; 2297 } 2298 fdp = data; 2299 for (i = 0; i < oldfds; i++, fdp++) { 2300 if (!fhold(fdesc->fd_ofiles[*fdp].fde_file)) { 2301 fdp = data; 2302 for (j = 0; j < i; j++, fdp++) { 2303 fdrop(fdesc->fd_ofiles[*fdp]. 2304 fde_file, td); 2305 } 2306 FILEDESC_SUNLOCK(fdesc); 2307 error = EBADF; 2308 goto out; 2309 } 2310 } 2311 fdp = data; 2312 fdep = (struct filedescent **) 2313 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2314 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2315 M_WAITOK); 2316 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2317 fde = &fdesc->fd_ofiles[*fdp]; 2318 fdep[i] = fdev; 2319 fdep[i]->fde_file = fde->fde_file; 2320 filecaps_copy(&fde->fde_caps, 2321 &fdep[i]->fde_caps, true); 2322 unp_internalize_fp(fdep[i]->fde_file); 2323 } 2324 FILEDESC_SUNLOCK(fdesc); 2325 break; 2326 2327 case SCM_TIMESTAMP: 2328 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2329 SCM_TIMESTAMP, SOL_SOCKET); 2330 if (*controlp == NULL) { 2331 error = ENOBUFS; 2332 goto out; 2333 } 2334 tv = (struct timeval *) 2335 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2336 microtime(tv); 2337 break; 2338 2339 case SCM_BINTIME: 2340 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2341 SCM_BINTIME, SOL_SOCKET); 2342 if (*controlp == NULL) { 2343 error = ENOBUFS; 2344 goto out; 2345 } 2346 bt = (struct bintime *) 2347 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2348 bintime(bt); 2349 break; 2350 2351 case SCM_REALTIME: 2352 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2353 SCM_REALTIME, SOL_SOCKET); 2354 if (*controlp == NULL) { 2355 error = ENOBUFS; 2356 goto out; 2357 } 2358 ts = (struct timespec *) 2359 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2360 nanotime(ts); 2361 break; 2362 2363 case SCM_MONOTONIC: 2364 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2365 SCM_MONOTONIC, SOL_SOCKET); 2366 if (*controlp == NULL) { 2367 error = ENOBUFS; 2368 goto out; 2369 } 2370 ts = (struct timespec *) 2371 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2372 nanouptime(ts); 2373 break; 2374 2375 default: 2376 error = EINVAL; 2377 goto out; 2378 } 2379 2380 if (*controlp != NULL) 2381 controlp = &(*controlp)->m_next; 2382 if (CMSG_SPACE(datalen) < clen) { 2383 clen -= CMSG_SPACE(datalen); 2384 cm = (struct cmsghdr *) 2385 ((caddr_t)cm + CMSG_SPACE(datalen)); 2386 } else { 2387 clen = 0; 2388 cm = NULL; 2389 } 2390 } 2391 2392 out: 2393 if (error != 0 && initial_controlp != NULL) 2394 unp_internalize_cleanup_rights(*initial_controlp); 2395 m_freem(control); 2396 return (error); 2397 } 2398 2399 static struct mbuf * 2400 unp_addsockcred(struct thread *td, struct mbuf *control, int mode) 2401 { 2402 struct mbuf *m, *n, *n_prev; 2403 const struct cmsghdr *cm; 2404 int ngroups, i, cmsgtype; 2405 size_t ctrlsz; 2406 2407 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2408 if (mode & UNP_WANTCRED_ALWAYS) { 2409 ctrlsz = SOCKCRED2SIZE(ngroups); 2410 cmsgtype = SCM_CREDS2; 2411 } else { 2412 ctrlsz = SOCKCREDSIZE(ngroups); 2413 cmsgtype = SCM_CREDS; 2414 } 2415 2416 m = sbcreatecontrol(NULL, ctrlsz, cmsgtype, SOL_SOCKET); 2417 if (m == NULL) 2418 return (control); 2419 2420 if (mode & UNP_WANTCRED_ALWAYS) { 2421 struct sockcred2 *sc; 2422 2423 sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *)); 2424 sc->sc_version = 0; 2425 sc->sc_pid = td->td_proc->p_pid; 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 } else { 2434 struct sockcred *sc; 2435 2436 sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *)); 2437 sc->sc_uid = td->td_ucred->cr_ruid; 2438 sc->sc_euid = td->td_ucred->cr_uid; 2439 sc->sc_gid = td->td_ucred->cr_rgid; 2440 sc->sc_egid = td->td_ucred->cr_gid; 2441 sc->sc_ngroups = ngroups; 2442 for (i = 0; i < sc->sc_ngroups; i++) 2443 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2444 } 2445 2446 /* 2447 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2448 * created SCM_CREDS control message (struct sockcred) has another 2449 * format. 2450 */ 2451 if (control != NULL && cmsgtype == SCM_CREDS) 2452 for (n = control, n_prev = NULL; n != NULL;) { 2453 cm = mtod(n, struct cmsghdr *); 2454 if (cm->cmsg_level == SOL_SOCKET && 2455 cm->cmsg_type == SCM_CREDS) { 2456 if (n_prev == NULL) 2457 control = n->m_next; 2458 else 2459 n_prev->m_next = n->m_next; 2460 n = m_free(n); 2461 } else { 2462 n_prev = n; 2463 n = n->m_next; 2464 } 2465 } 2466 2467 /* Prepend it to the head. */ 2468 m->m_next = control; 2469 return (m); 2470 } 2471 2472 static struct unpcb * 2473 fptounp(struct file *fp) 2474 { 2475 struct socket *so; 2476 2477 if (fp->f_type != DTYPE_SOCKET) 2478 return (NULL); 2479 if ((so = fp->f_data) == NULL) 2480 return (NULL); 2481 if (so->so_proto->pr_domain != &localdomain) 2482 return (NULL); 2483 return sotounpcb(so); 2484 } 2485 2486 static void 2487 unp_discard(struct file *fp) 2488 { 2489 struct unp_defer *dr; 2490 2491 if (unp_externalize_fp(fp)) { 2492 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2493 dr->ud_fp = fp; 2494 UNP_DEFERRED_LOCK(); 2495 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2496 UNP_DEFERRED_UNLOCK(); 2497 atomic_add_int(&unp_defers_count, 1); 2498 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2499 } else 2500 closef_nothread(fp); 2501 } 2502 2503 static void 2504 unp_process_defers(void *arg __unused, int pending) 2505 { 2506 struct unp_defer *dr; 2507 SLIST_HEAD(, unp_defer) drl; 2508 int count; 2509 2510 SLIST_INIT(&drl); 2511 for (;;) { 2512 UNP_DEFERRED_LOCK(); 2513 if (SLIST_FIRST(&unp_defers) == NULL) { 2514 UNP_DEFERRED_UNLOCK(); 2515 break; 2516 } 2517 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2518 UNP_DEFERRED_UNLOCK(); 2519 count = 0; 2520 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2521 SLIST_REMOVE_HEAD(&drl, ud_link); 2522 closef_nothread(dr->ud_fp); 2523 free(dr, M_TEMP); 2524 count++; 2525 } 2526 atomic_add_int(&unp_defers_count, -count); 2527 } 2528 } 2529 2530 static void 2531 unp_internalize_fp(struct file *fp) 2532 { 2533 struct unpcb *unp; 2534 2535 UNP_LINK_WLOCK(); 2536 if ((unp = fptounp(fp)) != NULL) { 2537 unp->unp_file = fp; 2538 unp->unp_msgcount++; 2539 } 2540 unp_rights++; 2541 UNP_LINK_WUNLOCK(); 2542 } 2543 2544 static int 2545 unp_externalize_fp(struct file *fp) 2546 { 2547 struct unpcb *unp; 2548 int ret; 2549 2550 UNP_LINK_WLOCK(); 2551 if ((unp = fptounp(fp)) != NULL) { 2552 unp->unp_msgcount--; 2553 ret = 1; 2554 } else 2555 ret = 0; 2556 unp_rights--; 2557 UNP_LINK_WUNLOCK(); 2558 return (ret); 2559 } 2560 2561 /* 2562 * unp_defer indicates whether additional work has been defered for a future 2563 * pass through unp_gc(). It is thread local and does not require explicit 2564 * synchronization. 2565 */ 2566 static int unp_marked; 2567 2568 static void 2569 unp_remove_dead_ref(struct filedescent **fdep, int fdcount) 2570 { 2571 struct unpcb *unp; 2572 struct file *fp; 2573 int i; 2574 2575 /* 2576 * This function can only be called from the gc task. 2577 */ 2578 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2579 ("%s: not on gc callout", __func__)); 2580 UNP_LINK_LOCK_ASSERT(); 2581 2582 for (i = 0; i < fdcount; i++) { 2583 fp = fdep[i]->fde_file; 2584 if ((unp = fptounp(fp)) == NULL) 2585 continue; 2586 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2587 continue; 2588 unp->unp_gcrefs--; 2589 } 2590 } 2591 2592 static void 2593 unp_restore_undead_ref(struct filedescent **fdep, int fdcount) 2594 { 2595 struct unpcb *unp; 2596 struct file *fp; 2597 int i; 2598 2599 /* 2600 * This function can only be called from the gc task. 2601 */ 2602 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2603 ("%s: not on gc callout", __func__)); 2604 UNP_LINK_LOCK_ASSERT(); 2605 2606 for (i = 0; i < fdcount; i++) { 2607 fp = fdep[i]->fde_file; 2608 if ((unp = fptounp(fp)) == NULL) 2609 continue; 2610 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2611 continue; 2612 unp->unp_gcrefs++; 2613 unp_marked++; 2614 } 2615 } 2616 2617 static void 2618 unp_gc_scan(struct unpcb *unp, void (*op)(struct filedescent **, int)) 2619 { 2620 struct socket *so, *soa; 2621 2622 so = unp->unp_socket; 2623 SOCK_LOCK(so); 2624 if (SOLISTENING(so)) { 2625 /* 2626 * Mark all sockets in our accept queue. 2627 */ 2628 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2629 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2630 continue; 2631 SOCKBUF_LOCK(&soa->so_rcv); 2632 unp_scan(soa->so_rcv.sb_mb, op); 2633 SOCKBUF_UNLOCK(&soa->so_rcv); 2634 } 2635 } else { 2636 /* 2637 * Mark all sockets we reference with RIGHTS. 2638 */ 2639 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2640 SOCKBUF_LOCK(&so->so_rcv); 2641 unp_scan(so->so_rcv.sb_mb, op); 2642 SOCKBUF_UNLOCK(&so->so_rcv); 2643 } 2644 } 2645 SOCK_UNLOCK(so); 2646 } 2647 2648 static int unp_recycled; 2649 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2650 "Number of unreachable sockets claimed by the garbage collector."); 2651 2652 static int unp_taskcount; 2653 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2654 "Number of times the garbage collector has run."); 2655 2656 SYSCTL_UINT(_net_local, OID_AUTO, sockcount, CTLFLAG_RD, &unp_count, 0, 2657 "Number of active local sockets."); 2658 2659 static void 2660 unp_gc(__unused void *arg, int pending) 2661 { 2662 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2663 NULL }; 2664 struct unp_head **head; 2665 struct unp_head unp_deadhead; /* List of potentially-dead sockets. */ 2666 struct file *f, **unref; 2667 struct unpcb *unp, *unptmp; 2668 int i, total, unp_unreachable; 2669 2670 LIST_INIT(&unp_deadhead); 2671 unp_taskcount++; 2672 UNP_LINK_RLOCK(); 2673 /* 2674 * First determine which sockets may be in cycles. 2675 */ 2676 unp_unreachable = 0; 2677 2678 for (head = heads; *head != NULL; head++) 2679 LIST_FOREACH(unp, *head, unp_link) { 2680 KASSERT((unp->unp_gcflag & ~UNPGC_IGNORE_RIGHTS) == 0, 2681 ("%s: unp %p has unexpected gc flags 0x%x", 2682 __func__, unp, (unsigned int)unp->unp_gcflag)); 2683 2684 f = unp->unp_file; 2685 2686 /* 2687 * Check for an unreachable socket potentially in a 2688 * cycle. It must be in a queue as indicated by 2689 * msgcount, and this must equal the file reference 2690 * count. Note that when msgcount is 0 the file is 2691 * NULL. 2692 */ 2693 if (f != NULL && unp->unp_msgcount != 0 && 2694 refcount_load(&f->f_count) == unp->unp_msgcount) { 2695 LIST_INSERT_HEAD(&unp_deadhead, unp, unp_dead); 2696 unp->unp_gcflag |= UNPGC_DEAD; 2697 unp->unp_gcrefs = unp->unp_msgcount; 2698 unp_unreachable++; 2699 } 2700 } 2701 2702 /* 2703 * Scan all sockets previously marked as potentially being in a cycle 2704 * and remove the references each socket holds on any UNPGC_DEAD 2705 * sockets in its queue. After this step, all remaining references on 2706 * sockets marked UNPGC_DEAD should not be part of any cycle. 2707 */ 2708 LIST_FOREACH(unp, &unp_deadhead, unp_dead) 2709 unp_gc_scan(unp, unp_remove_dead_ref); 2710 2711 /* 2712 * If a socket still has a non-negative refcount, it cannot be in a 2713 * cycle. In this case increment refcount of all children iteratively. 2714 * Stop the scan once we do a complete loop without discovering 2715 * a new reachable socket. 2716 */ 2717 do { 2718 unp_marked = 0; 2719 LIST_FOREACH_SAFE(unp, &unp_deadhead, unp_dead, unptmp) 2720 if (unp->unp_gcrefs > 0) { 2721 unp->unp_gcflag &= ~UNPGC_DEAD; 2722 LIST_REMOVE(unp, unp_dead); 2723 KASSERT(unp_unreachable > 0, 2724 ("%s: unp_unreachable underflow.", 2725 __func__)); 2726 unp_unreachable--; 2727 unp_gc_scan(unp, unp_restore_undead_ref); 2728 } 2729 } while (unp_marked); 2730 2731 UNP_LINK_RUNLOCK(); 2732 2733 if (unp_unreachable == 0) 2734 return; 2735 2736 /* 2737 * Allocate space for a local array of dead unpcbs. 2738 * TODO: can this path be simplified by instead using the local 2739 * dead list at unp_deadhead, after taking out references 2740 * on the file object and/or unpcb and dropping the link lock? 2741 */ 2742 unref = malloc(unp_unreachable * sizeof(struct file *), 2743 M_TEMP, M_WAITOK); 2744 2745 /* 2746 * Iterate looking for sockets which have been specifically marked 2747 * as unreachable and store them locally. 2748 */ 2749 UNP_LINK_RLOCK(); 2750 total = 0; 2751 LIST_FOREACH(unp, &unp_deadhead, unp_dead) { 2752 KASSERT((unp->unp_gcflag & UNPGC_DEAD) != 0, 2753 ("%s: unp %p not marked UNPGC_DEAD", __func__, unp)); 2754 unp->unp_gcflag &= ~UNPGC_DEAD; 2755 f = unp->unp_file; 2756 if (unp->unp_msgcount == 0 || f == NULL || 2757 refcount_load(&f->f_count) != unp->unp_msgcount || 2758 !fhold(f)) 2759 continue; 2760 unref[total++] = f; 2761 KASSERT(total <= unp_unreachable, 2762 ("%s: incorrect unreachable count.", __func__)); 2763 } 2764 UNP_LINK_RUNLOCK(); 2765 2766 /* 2767 * Now flush all sockets, free'ing rights. This will free the 2768 * struct files associated with these sockets but leave each socket 2769 * with one remaining ref. 2770 */ 2771 for (i = 0; i < total; i++) { 2772 struct socket *so; 2773 2774 so = unref[i]->f_data; 2775 CURVNET_SET(so->so_vnet); 2776 sorflush(so); 2777 CURVNET_RESTORE(); 2778 } 2779 2780 /* 2781 * And finally release the sockets so they can be reclaimed. 2782 */ 2783 for (i = 0; i < total; i++) 2784 fdrop(unref[i], NULL); 2785 unp_recycled += total; 2786 free(unref, M_TEMP); 2787 } 2788 2789 static void 2790 unp_dispose_mbuf(struct mbuf *m) 2791 { 2792 2793 if (m) 2794 unp_scan(m, unp_freerights); 2795 } 2796 2797 /* 2798 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2799 */ 2800 static void 2801 unp_dispose(struct socket *so) 2802 { 2803 struct unpcb *unp; 2804 2805 unp = sotounpcb(so); 2806 UNP_LINK_WLOCK(); 2807 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2808 UNP_LINK_WUNLOCK(); 2809 if (!SOLISTENING(so)) 2810 unp_dispose_mbuf(so->so_rcv.sb_mb); 2811 } 2812 2813 static void 2814 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2815 { 2816 struct mbuf *m; 2817 struct cmsghdr *cm; 2818 void *data; 2819 socklen_t clen, datalen; 2820 2821 while (m0 != NULL) { 2822 for (m = m0; m; m = m->m_next) { 2823 if (m->m_type != MT_CONTROL) 2824 continue; 2825 2826 cm = mtod(m, struct cmsghdr *); 2827 clen = m->m_len; 2828 2829 while (cm != NULL) { 2830 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2831 break; 2832 2833 data = CMSG_DATA(cm); 2834 datalen = (caddr_t)cm + cm->cmsg_len 2835 - (caddr_t)data; 2836 2837 if (cm->cmsg_level == SOL_SOCKET && 2838 cm->cmsg_type == SCM_RIGHTS) { 2839 (*op)(data, datalen / 2840 sizeof(struct filedescent *)); 2841 } 2842 2843 if (CMSG_SPACE(datalen) < clen) { 2844 clen -= CMSG_SPACE(datalen); 2845 cm = (struct cmsghdr *) 2846 ((caddr_t)cm + CMSG_SPACE(datalen)); 2847 } else { 2848 clen = 0; 2849 cm = NULL; 2850 } 2851 } 2852 } 2853 m0 = m0->m_nextpkt; 2854 } 2855 } 2856 2857 /* 2858 * A helper function called by VFS before socket-type vnode reclamation. 2859 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2860 * use count. 2861 */ 2862 void 2863 vfs_unp_reclaim(struct vnode *vp) 2864 { 2865 struct unpcb *unp; 2866 int active; 2867 struct mtx *vplock; 2868 2869 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2870 KASSERT(vp->v_type == VSOCK, 2871 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2872 2873 active = 0; 2874 vplock = mtx_pool_find(mtxpool_sleep, vp); 2875 mtx_lock(vplock); 2876 VOP_UNP_CONNECT(vp, &unp); 2877 if (unp == NULL) 2878 goto done; 2879 UNP_PCB_LOCK(unp); 2880 if (unp->unp_vnode == vp) { 2881 VOP_UNP_DETACH(vp); 2882 unp->unp_vnode = NULL; 2883 active = 1; 2884 } 2885 UNP_PCB_UNLOCK(unp); 2886 done: 2887 mtx_unlock(vplock); 2888 if (active) 2889 vunref(vp); 2890 } 2891 2892 #ifdef DDB 2893 static void 2894 db_print_indent(int indent) 2895 { 2896 int i; 2897 2898 for (i = 0; i < indent; i++) 2899 db_printf(" "); 2900 } 2901 2902 static void 2903 db_print_unpflags(int unp_flags) 2904 { 2905 int comma; 2906 2907 comma = 0; 2908 if (unp_flags & UNP_HAVEPC) { 2909 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2910 comma = 1; 2911 } 2912 if (unp_flags & UNP_WANTCRED_ALWAYS) { 2913 db_printf("%sUNP_WANTCRED_ALWAYS", comma ? ", " : ""); 2914 comma = 1; 2915 } 2916 if (unp_flags & UNP_WANTCRED_ONESHOT) { 2917 db_printf("%sUNP_WANTCRED_ONESHOT", comma ? ", " : ""); 2918 comma = 1; 2919 } 2920 if (unp_flags & UNP_CONNWAIT) { 2921 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2922 comma = 1; 2923 } 2924 if (unp_flags & UNP_CONNECTING) { 2925 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2926 comma = 1; 2927 } 2928 if (unp_flags & UNP_BINDING) { 2929 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2930 comma = 1; 2931 } 2932 } 2933 2934 static void 2935 db_print_xucred(int indent, struct xucred *xu) 2936 { 2937 int comma, i; 2938 2939 db_print_indent(indent); 2940 db_printf("cr_version: %u cr_uid: %u cr_pid: %d cr_ngroups: %d\n", 2941 xu->cr_version, xu->cr_uid, xu->cr_pid, xu->cr_ngroups); 2942 db_print_indent(indent); 2943 db_printf("cr_groups: "); 2944 comma = 0; 2945 for (i = 0; i < xu->cr_ngroups; i++) { 2946 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2947 comma = 1; 2948 } 2949 db_printf("\n"); 2950 } 2951 2952 static void 2953 db_print_unprefs(int indent, struct unp_head *uh) 2954 { 2955 struct unpcb *unp; 2956 int counter; 2957 2958 counter = 0; 2959 LIST_FOREACH(unp, uh, unp_reflink) { 2960 if (counter % 4 == 0) 2961 db_print_indent(indent); 2962 db_printf("%p ", unp); 2963 if (counter % 4 == 3) 2964 db_printf("\n"); 2965 counter++; 2966 } 2967 if (counter != 0 && counter % 4 != 0) 2968 db_printf("\n"); 2969 } 2970 2971 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2972 { 2973 struct unpcb *unp; 2974 2975 if (!have_addr) { 2976 db_printf("usage: show unpcb <addr>\n"); 2977 return; 2978 } 2979 unp = (struct unpcb *)addr; 2980 2981 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2982 unp->unp_vnode); 2983 2984 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2985 unp->unp_conn); 2986 2987 db_printf("unp_refs:\n"); 2988 db_print_unprefs(2, &unp->unp_refs); 2989 2990 /* XXXRW: Would be nice to print the full address, if any. */ 2991 db_printf("unp_addr: %p\n", unp->unp_addr); 2992 2993 db_printf("unp_gencnt: %llu\n", 2994 (unsigned long long)unp->unp_gencnt); 2995 2996 db_printf("unp_flags: %x (", unp->unp_flags); 2997 db_print_unpflags(unp->unp_flags); 2998 db_printf(")\n"); 2999 3000 db_printf("unp_peercred:\n"); 3001 db_print_xucred(2, &unp->unp_peercred); 3002 3003 db_printf("unp_refcount: %u\n", unp->unp_refcount); 3004 } 3005 #endif 3006