1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All Rights Reserved. 6 * Copyright (c) 2004-2009 Robert N. M. Watson All Rights Reserved. 7 * Copyright (c) 2018 Matthew Macy 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 34 */ 35 36 /* 37 * UNIX Domain (Local) Sockets 38 * 39 * This is an implementation of UNIX (local) domain sockets. Each socket has 40 * an associated struct unpcb (UNIX protocol control block). Stream sockets 41 * may be connected to 0 or 1 other socket. Datagram sockets may be 42 * connected to 0, 1, or many other sockets. Sockets may be created and 43 * connected in pairs (socketpair(2)), or bound/connected to using the file 44 * system name space. For most purposes, only the receive socket buffer is 45 * used, as sending on one socket delivers directly to the receive socket 46 * buffer of a second socket. 47 * 48 * The implementation is substantially complicated by the fact that 49 * "ancillary data", such as file descriptors or credentials, may be passed 50 * across UNIX domain sockets. The potential for passing UNIX domain sockets 51 * over other UNIX domain sockets requires the implementation of a simple 52 * garbage collector to find and tear down cycles of disconnected sockets. 53 * 54 * TODO: 55 * RDM 56 * rethink name space problems 57 * need a proper out-of-band 58 */ 59 60 #include <sys/cdefs.h> 61 __FBSDID("$FreeBSD$"); 62 63 #include "opt_ddb.h" 64 65 #include <sys/param.h> 66 #include <sys/capsicum.h> 67 #include <sys/domain.h> 68 #include <sys/eventhandler.h> 69 #include <sys/fcntl.h> 70 #include <sys/file.h> 71 #include <sys/filedesc.h> 72 #include <sys/kernel.h> 73 #include <sys/lock.h> 74 #include <sys/malloc.h> 75 #include <sys/mbuf.h> 76 #include <sys/mount.h> 77 #include <sys/mutex.h> 78 #include <sys/namei.h> 79 #include <sys/proc.h> 80 #include <sys/protosw.h> 81 #include <sys/queue.h> 82 #include <sys/resourcevar.h> 83 #include <sys/rwlock.h> 84 #include <sys/socket.h> 85 #include <sys/socketvar.h> 86 #include <sys/signalvar.h> 87 #include <sys/stat.h> 88 #include <sys/sx.h> 89 #include <sys/sysctl.h> 90 #include <sys/systm.h> 91 #include <sys/taskqueue.h> 92 #include <sys/un.h> 93 #include <sys/unpcb.h> 94 #include <sys/vnode.h> 95 96 #include <net/vnet.h> 97 98 #ifdef DDB 99 #include <ddb/ddb.h> 100 #endif 101 102 #include <security/mac/mac_framework.h> 103 104 #include <vm/uma.h> 105 106 MALLOC_DECLARE(M_FILECAPS); 107 108 /* 109 * See unpcb.h for the locking key. 110 */ 111 112 static uma_zone_t unp_zone; 113 static unp_gen_t unp_gencnt; /* (l) */ 114 static u_int unp_count; /* (l) Count of local sockets. */ 115 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 116 static int unp_rights; /* (g) File descriptors in flight. */ 117 static struct unp_head unp_shead; /* (l) List of stream sockets. */ 118 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 119 static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */ 120 121 struct unp_defer { 122 SLIST_ENTRY(unp_defer) ud_link; 123 struct file *ud_fp; 124 }; 125 static SLIST_HEAD(, unp_defer) unp_defers; 126 static int unp_defers_count; 127 128 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 129 130 /* 131 * Garbage collection of cyclic file descriptor/socket references occurs 132 * asynchronously in a taskqueue context in order to avoid recursion and 133 * reentrance in the UNIX domain socket, file descriptor, and socket layer 134 * code. See unp_gc() for a full description. 135 */ 136 static struct timeout_task unp_gc_task; 137 138 /* 139 * The close of unix domain sockets attached as SCM_RIGHTS is 140 * postponed to the taskqueue, to avoid arbitrary recursion depth. 141 * The attached sockets might have another sockets attached. 142 */ 143 static struct task unp_defer_task; 144 145 /* 146 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 147 * stream sockets, although the total for sender and receiver is actually 148 * only PIPSIZ. 149 * 150 * Datagram sockets really use the sendspace as the maximum datagram size, 151 * and don't really want to reserve the sendspace. Their recvspace should be 152 * large enough for at least one max-size datagram plus address. 153 */ 154 #ifndef PIPSIZ 155 #define PIPSIZ 8192 156 #endif 157 static u_long unpst_sendspace = PIPSIZ; 158 static u_long unpst_recvspace = PIPSIZ; 159 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 160 static u_long unpdg_recvspace = 16*1024; /* support 8KB syslog msgs */ 161 static u_long unpsp_sendspace = PIPSIZ; /* really max datagram size */ 162 static u_long unpsp_recvspace = PIPSIZ; 163 164 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 165 "Local domain"); 166 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, 167 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 168 "SOCK_STREAM"); 169 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, 170 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 171 "SOCK_DGRAM"); 172 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, 173 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 174 "SOCK_SEQPACKET"); 175 176 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 177 &unpst_sendspace, 0, "Default stream send space."); 178 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 179 &unpst_recvspace, 0, "Default stream receive space."); 180 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 181 &unpdg_sendspace, 0, "Default datagram send space."); 182 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 183 &unpdg_recvspace, 0, "Default datagram receive space."); 184 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW, 185 &unpsp_sendspace, 0, "Default seqpacket send space."); 186 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW, 187 &unpsp_recvspace, 0, "Default seqpacket receive space."); 188 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 189 "File descriptors in flight."); 190 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD, 191 &unp_defers_count, 0, 192 "File descriptors deferred to taskqueue for close."); 193 194 /* 195 * Locking and synchronization: 196 * 197 * Several types of locks exist in the local domain socket implementation: 198 * - a global linkage lock 199 * - a global connection list lock 200 * - the mtxpool lock 201 * - per-unpcb mutexes 202 * 203 * The linkage lock protects the global socket lists, the generation number 204 * counter and garbage collector state. 205 * 206 * The connection list lock protects the list of referring sockets in a datagram 207 * socket PCB. This lock is also overloaded to protect a global list of 208 * sockets whose buffers contain socket references in the form of SCM_RIGHTS 209 * messages. To avoid recursion, such references are released by a dedicated 210 * thread. 211 * 212 * The mtxpool lock protects the vnode from being modified while referenced. 213 * Lock ordering rules require that it be acquired before any PCB locks. 214 * 215 * The unpcb lock (unp_mtx) protects the most commonly referenced fields in the 216 * unpcb. This includes the unp_conn field, which either links two connected 217 * PCBs together (for connected socket types) or points at the destination 218 * socket (for connectionless socket types). The operations of creating or 219 * destroying a connection therefore involve locking multiple PCBs. To avoid 220 * lock order reversals, in some cases this involves dropping a PCB lock and 221 * using a reference counter to maintain liveness. 222 * 223 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 224 * allocated in pru_attach() and freed in pru_detach(). The validity of that 225 * pointer is an invariant, so no lock is required to dereference the so_pcb 226 * pointer if a valid socket reference is held by the caller. In practice, 227 * this is always true during operations performed on a socket. Each unpcb 228 * has a back-pointer to its socket, unp_socket, which will be stable under 229 * the same circumstances. 230 * 231 * This pointer may only be safely dereferenced as long as a valid reference 232 * to the unpcb is held. Typically, this reference will be from the socket, 233 * or from another unpcb when the referring unpcb's lock is held (in order 234 * that the reference not be invalidated during use). For example, to follow 235 * unp->unp_conn->unp_socket, you need to hold a lock on unp_conn to guarantee 236 * that detach is not run clearing unp_socket. 237 * 238 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 239 * protocols, bind() is a non-atomic operation, and connect() requires 240 * potential sleeping in the protocol, due to potentially waiting on local or 241 * distributed file systems. We try to separate "lookup" operations, which 242 * may sleep, and the IPC operations themselves, which typically can occur 243 * with relative atomicity as locks can be held over the entire operation. 244 * 245 * Another tricky issue is simultaneous multi-threaded or multi-process 246 * access to a single UNIX domain socket. These are handled by the flags 247 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 248 * binding, both of which involve dropping UNIX domain socket locks in order 249 * to perform namei() and other file system operations. 250 */ 251 static struct rwlock unp_link_rwlock; 252 static struct mtx unp_defers_lock; 253 254 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 255 "unp_link_rwlock") 256 257 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 258 RA_LOCKED) 259 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 260 RA_UNLOCKED) 261 262 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 263 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 264 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 265 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 266 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 267 RA_WLOCKED) 268 #define UNP_LINK_WOWNED() rw_wowned(&unp_link_rwlock) 269 270 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \ 271 "unp_defer", NULL, MTX_DEF) 272 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock) 273 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock) 274 275 #define UNP_REF_LIST_LOCK() UNP_DEFERRED_LOCK(); 276 #define UNP_REF_LIST_UNLOCK() UNP_DEFERRED_UNLOCK(); 277 278 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 279 "unp", "unp", \ 280 MTX_DUPOK|MTX_DEF) 281 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 282 #define UNP_PCB_LOCKPTR(unp) (&(unp)->unp_mtx) 283 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 284 #define UNP_PCB_TRYLOCK(unp) mtx_trylock(&(unp)->unp_mtx) 285 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 286 #define UNP_PCB_OWNED(unp) mtx_owned(&(unp)->unp_mtx) 287 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 288 #define UNP_PCB_UNLOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_NOTOWNED) 289 290 static int uipc_connect2(struct socket *, struct socket *); 291 static int uipc_ctloutput(struct socket *, struct sockopt *); 292 static int unp_connect(struct socket *, struct sockaddr *, 293 struct thread *); 294 static int unp_connectat(int, struct socket *, struct sockaddr *, 295 struct thread *); 296 static int unp_connect2(struct socket *so, struct socket *so2, int); 297 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 298 static void unp_dispose(struct socket *so); 299 static void unp_dispose_mbuf(struct mbuf *); 300 static void unp_shutdown(struct unpcb *); 301 static void unp_drop(struct unpcb *); 302 static void unp_gc(__unused void *, int); 303 static void unp_scan(struct mbuf *, void (*)(struct filedescent **, int)); 304 static void unp_discard(struct file *); 305 static void unp_freerights(struct filedescent **, int); 306 static 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 /* 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 if (error) { 673 VOP_VPUT_PAIR(nd.ni_dvp, NULL, true); 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 vref(vp); 690 VOP_VPUT_PAIR(nd.ni_dvp, &vp, true); 691 vn_finished_write(mp); 692 free(buf, M_TEMP); 693 return (0); 694 695 error: 696 UNP_PCB_LOCK(unp); 697 unp->unp_flags &= ~UNP_BINDING; 698 UNP_PCB_UNLOCK(unp); 699 free(buf, M_TEMP); 700 return (error); 701 } 702 703 static int 704 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 705 { 706 707 return (uipc_bindat(AT_FDCWD, so, nam, td)); 708 } 709 710 static int 711 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 712 { 713 int error; 714 715 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 716 error = unp_connect(so, nam, td); 717 return (error); 718 } 719 720 static int 721 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 722 struct thread *td) 723 { 724 int error; 725 726 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 727 error = unp_connectat(fd, so, nam, td); 728 return (error); 729 } 730 731 static void 732 uipc_close(struct socket *so) 733 { 734 struct unpcb *unp, *unp2; 735 struct vnode *vp = NULL; 736 struct mtx *vplock; 737 738 unp = sotounpcb(so); 739 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 740 741 vplock = NULL; 742 if ((vp = unp->unp_vnode) != NULL) { 743 vplock = mtx_pool_find(mtxpool_sleep, vp); 744 mtx_lock(vplock); 745 } 746 UNP_PCB_LOCK(unp); 747 if (vp && unp->unp_vnode == NULL) { 748 mtx_unlock(vplock); 749 vp = NULL; 750 } 751 if (vp != NULL) { 752 VOP_UNP_DETACH(vp); 753 unp->unp_vnode = NULL; 754 } 755 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 756 unp_disconnect(unp, unp2); 757 else 758 UNP_PCB_UNLOCK(unp); 759 if (vp) { 760 mtx_unlock(vplock); 761 vrele(vp); 762 } 763 } 764 765 static int 766 uipc_connect2(struct socket *so1, struct socket *so2) 767 { 768 struct unpcb *unp, *unp2; 769 int error; 770 771 unp = so1->so_pcb; 772 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 773 unp2 = so2->so_pcb; 774 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 775 unp_pcb_lock_pair(unp, unp2); 776 error = unp_connect2(so1, so2, PRU_CONNECT2); 777 unp_pcb_unlock_pair(unp, unp2); 778 return (error); 779 } 780 781 static void 782 uipc_detach(struct socket *so) 783 { 784 struct unpcb *unp, *unp2; 785 struct mtx *vplock; 786 struct vnode *vp; 787 int local_unp_rights; 788 789 unp = sotounpcb(so); 790 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 791 792 vp = NULL; 793 vplock = NULL; 794 795 SOCK_LOCK(so); 796 if (!SOLISTENING(so)) { 797 /* 798 * Once the socket is removed from the global lists, 799 * uipc_ready() will not be able to locate its socket buffer, so 800 * clear the buffer now. At this point internalized rights have 801 * already been disposed of. 802 */ 803 sbrelease(&so->so_rcv, so); 804 } 805 SOCK_UNLOCK(so); 806 807 UNP_LINK_WLOCK(); 808 LIST_REMOVE(unp, unp_link); 809 if (unp->unp_gcflag & UNPGC_DEAD) 810 LIST_REMOVE(unp, unp_dead); 811 unp->unp_gencnt = ++unp_gencnt; 812 --unp_count; 813 UNP_LINK_WUNLOCK(); 814 815 UNP_PCB_UNLOCK_ASSERT(unp); 816 restart: 817 if ((vp = unp->unp_vnode) != NULL) { 818 vplock = mtx_pool_find(mtxpool_sleep, vp); 819 mtx_lock(vplock); 820 } 821 UNP_PCB_LOCK(unp); 822 if (unp->unp_vnode != vp && unp->unp_vnode != NULL) { 823 if (vplock) 824 mtx_unlock(vplock); 825 UNP_PCB_UNLOCK(unp); 826 goto restart; 827 } 828 if ((vp = unp->unp_vnode) != NULL) { 829 VOP_UNP_DETACH(vp); 830 unp->unp_vnode = NULL; 831 } 832 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 833 unp_disconnect(unp, unp2); 834 else 835 UNP_PCB_UNLOCK(unp); 836 837 UNP_REF_LIST_LOCK(); 838 while (!LIST_EMPTY(&unp->unp_refs)) { 839 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 840 841 unp_pcb_hold(ref); 842 UNP_REF_LIST_UNLOCK(); 843 844 MPASS(ref != unp); 845 UNP_PCB_UNLOCK_ASSERT(ref); 846 unp_drop(ref); 847 UNP_REF_LIST_LOCK(); 848 } 849 UNP_REF_LIST_UNLOCK(); 850 851 UNP_PCB_LOCK(unp); 852 local_unp_rights = unp_rights; 853 unp->unp_socket->so_pcb = NULL; 854 unp->unp_socket = NULL; 855 free(unp->unp_addr, M_SONAME); 856 unp->unp_addr = NULL; 857 if (!unp_pcb_rele(unp)) 858 UNP_PCB_UNLOCK(unp); 859 if (vp) { 860 mtx_unlock(vplock); 861 vrele(vp); 862 } 863 if (local_unp_rights) 864 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 865 } 866 867 static int 868 uipc_disconnect(struct socket *so) 869 { 870 struct unpcb *unp, *unp2; 871 872 unp = sotounpcb(so); 873 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 874 875 UNP_PCB_LOCK(unp); 876 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) 877 unp_disconnect(unp, unp2); 878 else 879 UNP_PCB_UNLOCK(unp); 880 return (0); 881 } 882 883 static int 884 uipc_listen(struct socket *so, int backlog, struct thread *td) 885 { 886 struct unpcb *unp; 887 int error; 888 889 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 890 return (EOPNOTSUPP); 891 892 /* 893 * Synchronize with concurrent connection attempts. 894 */ 895 error = 0; 896 unp = sotounpcb(so); 897 UNP_PCB_LOCK(unp); 898 if (unp->unp_conn != NULL || (unp->unp_flags & UNP_CONNECTING) != 0) 899 error = EINVAL; 900 else if (unp->unp_vnode == NULL) 901 error = EDESTADDRREQ; 902 if (error != 0) { 903 UNP_PCB_UNLOCK(unp); 904 return (error); 905 } 906 907 SOCK_LOCK(so); 908 error = solisten_proto_check(so); 909 if (error == 0) { 910 cru2xt(td, &unp->unp_peercred); 911 solisten_proto(so, backlog); 912 } 913 SOCK_UNLOCK(so); 914 UNP_PCB_UNLOCK(unp); 915 return (error); 916 } 917 918 static int 919 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 920 { 921 struct unpcb *unp, *unp2; 922 const struct sockaddr *sa; 923 924 unp = sotounpcb(so); 925 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 926 927 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 928 UNP_LINK_RLOCK(); 929 /* 930 * XXX: It seems that this test always fails even when connection is 931 * established. So, this else clause is added as workaround to 932 * return PF_LOCAL sockaddr. 933 */ 934 unp2 = unp->unp_conn; 935 if (unp2 != NULL) { 936 UNP_PCB_LOCK(unp2); 937 if (unp2->unp_addr != NULL) 938 sa = (struct sockaddr *) unp2->unp_addr; 939 else 940 sa = &sun_noname; 941 bcopy(sa, *nam, sa->sa_len); 942 UNP_PCB_UNLOCK(unp2); 943 } else { 944 sa = &sun_noname; 945 bcopy(sa, *nam, sa->sa_len); 946 } 947 UNP_LINK_RUNLOCK(); 948 return (0); 949 } 950 951 static int 952 uipc_rcvd(struct socket *so, int flags) 953 { 954 struct unpcb *unp, *unp2; 955 struct socket *so2; 956 u_int mbcnt, sbcc; 957 958 unp = sotounpcb(so); 959 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 960 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 961 ("%s: socktype %d", __func__, so->so_type)); 962 963 /* 964 * Adjust backpressure on sender and wakeup any waiting to write. 965 * 966 * The unp lock is acquired to maintain the validity of the unp_conn 967 * pointer; no lock on unp2 is required as unp2->unp_socket will be 968 * static as long as we don't permit unp2 to disconnect from unp, 969 * which is prevented by the lock on unp. We cache values from 970 * so_rcv to avoid holding the so_rcv lock over the entire 971 * transaction on the remote so_snd. 972 */ 973 SOCKBUF_LOCK(&so->so_rcv); 974 mbcnt = so->so_rcv.sb_mbcnt; 975 sbcc = sbavail(&so->so_rcv); 976 SOCKBUF_UNLOCK(&so->so_rcv); 977 /* 978 * There is a benign race condition at this point. If we're planning to 979 * clear SB_STOP, but uipc_send is called on the connected socket at 980 * this instant, it might add data to the sockbuf and set SB_STOP. Then 981 * we would erroneously clear SB_STOP below, even though the sockbuf is 982 * full. The race is benign because the only ill effect is to allow the 983 * sockbuf to exceed its size limit, and the size limits are not 984 * strictly guaranteed anyway. 985 */ 986 UNP_PCB_LOCK(unp); 987 unp2 = unp->unp_conn; 988 if (unp2 == NULL) { 989 UNP_PCB_UNLOCK(unp); 990 return (0); 991 } 992 so2 = unp2->unp_socket; 993 SOCKBUF_LOCK(&so2->so_snd); 994 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 995 so2->so_snd.sb_flags &= ~SB_STOP; 996 sowwakeup_locked(so2); 997 UNP_PCB_UNLOCK(unp); 998 return (0); 999 } 1000 1001 static int 1002 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 1003 struct mbuf *control, struct thread *td) 1004 { 1005 struct unpcb *unp, *unp2; 1006 struct socket *so2; 1007 u_int mbcnt, sbcc; 1008 int error; 1009 1010 unp = sotounpcb(so); 1011 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 1012 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 1013 so->so_type == SOCK_SEQPACKET, 1014 ("%s: socktype %d", __func__, so->so_type)); 1015 1016 error = 0; 1017 if (flags & PRUS_OOB) { 1018 error = EOPNOTSUPP; 1019 goto release; 1020 } 1021 if (control != NULL && (error = unp_internalize(&control, td))) 1022 goto release; 1023 1024 unp2 = NULL; 1025 switch (so->so_type) { 1026 case SOCK_DGRAM: 1027 { 1028 const struct sockaddr *from; 1029 1030 if (nam != NULL) { 1031 error = unp_connect(so, nam, td); 1032 if (error != 0) 1033 break; 1034 } 1035 UNP_PCB_LOCK(unp); 1036 1037 /* 1038 * Because connect() and send() are non-atomic in a sendto() 1039 * with a target address, it's possible that the socket will 1040 * have disconnected before the send() can run. In that case 1041 * return the slightly counter-intuitive but otherwise 1042 * correct error that the socket is not connected. 1043 */ 1044 unp2 = unp_pcb_lock_peer(unp); 1045 if (unp2 == NULL) { 1046 UNP_PCB_UNLOCK(unp); 1047 error = ENOTCONN; 1048 break; 1049 } 1050 1051 if (unp2->unp_flags & UNP_WANTCRED_MASK) 1052 control = unp_addsockcred(td, control, 1053 unp2->unp_flags); 1054 if (unp->unp_addr != NULL) 1055 from = (struct sockaddr *)unp->unp_addr; 1056 else 1057 from = &sun_noname; 1058 so2 = unp2->unp_socket; 1059 SOCKBUF_LOCK(&so2->so_rcv); 1060 if (sbappendaddr_locked(&so2->so_rcv, from, m, 1061 control)) { 1062 sorwakeup_locked(so2); 1063 m = NULL; 1064 control = NULL; 1065 } else { 1066 soroverflow_locked(so2); 1067 error = ENOBUFS; 1068 } 1069 if (nam != NULL) 1070 unp_disconnect(unp, unp2); 1071 else 1072 unp_pcb_unlock_pair(unp, unp2); 1073 break; 1074 } 1075 1076 case SOCK_SEQPACKET: 1077 case SOCK_STREAM: 1078 if ((so->so_state & SS_ISCONNECTED) == 0) { 1079 if (nam != NULL) { 1080 error = unp_connect(so, nam, td); 1081 if (error != 0) 1082 break; 1083 } else { 1084 error = ENOTCONN; 1085 break; 1086 } 1087 } 1088 1089 UNP_PCB_LOCK(unp); 1090 if ((unp2 = unp_pcb_lock_peer(unp)) == NULL) { 1091 UNP_PCB_UNLOCK(unp); 1092 error = ENOTCONN; 1093 break; 1094 } else if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 1095 unp_pcb_unlock_pair(unp, unp2); 1096 error = EPIPE; 1097 break; 1098 } 1099 UNP_PCB_UNLOCK(unp); 1100 if ((so2 = unp2->unp_socket) == NULL) { 1101 UNP_PCB_UNLOCK(unp2); 1102 error = ENOTCONN; 1103 break; 1104 } 1105 SOCKBUF_LOCK(&so2->so_rcv); 1106 if (unp2->unp_flags & UNP_WANTCRED_MASK) { 1107 /* 1108 * Credentials are passed only once on SOCK_STREAM and 1109 * SOCK_SEQPACKET (LOCAL_CREDS => WANTCRED_ONESHOT), or 1110 * forever (LOCAL_CREDS_PERSISTENT => WANTCRED_ALWAYS). 1111 */ 1112 control = unp_addsockcred(td, control, unp2->unp_flags); 1113 unp2->unp_flags &= ~UNP_WANTCRED_ONESHOT; 1114 } 1115 1116 /* 1117 * Send to paired receive port and wake up readers. Don't 1118 * check for space available in the receive buffer if we're 1119 * attaching ancillary data; Unix domain sockets only check 1120 * for space in the sending sockbuf, and that check is 1121 * performed one level up the stack. At that level we cannot 1122 * precisely account for the amount of buffer space used 1123 * (e.g., because control messages are not yet internalized). 1124 */ 1125 switch (so->so_type) { 1126 case SOCK_STREAM: 1127 if (control != NULL) { 1128 sbappendcontrol_locked(&so2->so_rcv, m, 1129 control, flags); 1130 control = NULL; 1131 } else 1132 sbappend_locked(&so2->so_rcv, m, flags); 1133 break; 1134 1135 case SOCK_SEQPACKET: 1136 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 1137 &sun_noname, m, control)) 1138 control = NULL; 1139 break; 1140 } 1141 1142 mbcnt = so2->so_rcv.sb_mbcnt; 1143 sbcc = sbavail(&so2->so_rcv); 1144 if (sbcc) 1145 sorwakeup_locked(so2); 1146 else 1147 SOCKBUF_UNLOCK(&so2->so_rcv); 1148 1149 /* 1150 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1151 * it would be possible for uipc_rcvd to be called at this 1152 * point, drain the receiving sockbuf, clear SB_STOP, and then 1153 * we would set SB_STOP below. That could lead to an empty 1154 * sockbuf having SB_STOP set 1155 */ 1156 SOCKBUF_LOCK(&so->so_snd); 1157 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1158 so->so_snd.sb_flags |= SB_STOP; 1159 SOCKBUF_UNLOCK(&so->so_snd); 1160 UNP_PCB_UNLOCK(unp2); 1161 m = NULL; 1162 break; 1163 } 1164 1165 /* 1166 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1167 */ 1168 if (flags & PRUS_EOF) { 1169 UNP_PCB_LOCK(unp); 1170 socantsendmore(so); 1171 unp_shutdown(unp); 1172 UNP_PCB_UNLOCK(unp); 1173 } 1174 if (control != NULL && error != 0) 1175 unp_dispose_mbuf(control); 1176 1177 release: 1178 if (control != NULL) 1179 m_freem(control); 1180 /* 1181 * In case of PRUS_NOTREADY, uipc_ready() is responsible 1182 * for freeing memory. 1183 */ 1184 if (m != NULL && (flags & PRUS_NOTREADY) == 0) 1185 m_freem(m); 1186 return (error); 1187 } 1188 1189 static bool 1190 uipc_ready_scan(struct socket *so, struct mbuf *m, int count, int *errorp) 1191 { 1192 struct mbuf *mb, *n; 1193 struct sockbuf *sb; 1194 1195 SOCK_LOCK(so); 1196 if (SOLISTENING(so)) { 1197 SOCK_UNLOCK(so); 1198 return (false); 1199 } 1200 mb = NULL; 1201 sb = &so->so_rcv; 1202 SOCKBUF_LOCK(sb); 1203 if (sb->sb_fnrdy != NULL) { 1204 for (mb = sb->sb_mb, n = mb->m_nextpkt; mb != NULL;) { 1205 if (mb == m) { 1206 *errorp = sbready(sb, m, count); 1207 break; 1208 } 1209 mb = mb->m_next; 1210 if (mb == NULL) { 1211 mb = n; 1212 if (mb != NULL) 1213 n = mb->m_nextpkt; 1214 } 1215 } 1216 } 1217 SOCKBUF_UNLOCK(sb); 1218 SOCK_UNLOCK(so); 1219 return (mb != NULL); 1220 } 1221 1222 static int 1223 uipc_ready(struct socket *so, struct mbuf *m, int count) 1224 { 1225 struct unpcb *unp, *unp2; 1226 struct socket *so2; 1227 int error, i; 1228 1229 unp = sotounpcb(so); 1230 1231 KASSERT(so->so_type == SOCK_STREAM, 1232 ("%s: unexpected socket type for %p", __func__, so)); 1233 1234 UNP_PCB_LOCK(unp); 1235 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) { 1236 UNP_PCB_UNLOCK(unp); 1237 so2 = unp2->unp_socket; 1238 SOCKBUF_LOCK(&so2->so_rcv); 1239 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1240 sorwakeup_locked(so2); 1241 else 1242 SOCKBUF_UNLOCK(&so2->so_rcv); 1243 UNP_PCB_UNLOCK(unp2); 1244 return (error); 1245 } 1246 UNP_PCB_UNLOCK(unp); 1247 1248 /* 1249 * The receiving socket has been disconnected, but may still be valid. 1250 * In this case, the now-ready mbufs are still present in its socket 1251 * buffer, so perform an exhaustive search before giving up and freeing 1252 * the mbufs. 1253 */ 1254 UNP_LINK_RLOCK(); 1255 LIST_FOREACH(unp, &unp_shead, unp_link) { 1256 if (uipc_ready_scan(unp->unp_socket, m, count, &error)) 1257 break; 1258 } 1259 UNP_LINK_RUNLOCK(); 1260 1261 if (unp == NULL) { 1262 for (i = 0; i < count; i++) 1263 m = m_free(m); 1264 error = ECONNRESET; 1265 } 1266 return (error); 1267 } 1268 1269 static int 1270 uipc_sense(struct socket *so, struct stat *sb) 1271 { 1272 struct unpcb *unp; 1273 1274 unp = sotounpcb(so); 1275 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1276 1277 sb->st_blksize = so->so_snd.sb_hiwat; 1278 sb->st_dev = NODEV; 1279 sb->st_ino = unp->unp_ino; 1280 return (0); 1281 } 1282 1283 static int 1284 uipc_shutdown(struct socket *so) 1285 { 1286 struct unpcb *unp; 1287 1288 unp = sotounpcb(so); 1289 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1290 1291 UNP_PCB_LOCK(unp); 1292 socantsendmore(so); 1293 unp_shutdown(unp); 1294 UNP_PCB_UNLOCK(unp); 1295 return (0); 1296 } 1297 1298 static int 1299 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1300 { 1301 struct unpcb *unp; 1302 const struct sockaddr *sa; 1303 1304 unp = sotounpcb(so); 1305 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1306 1307 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1308 UNP_PCB_LOCK(unp); 1309 if (unp->unp_addr != NULL) 1310 sa = (struct sockaddr *) unp->unp_addr; 1311 else 1312 sa = &sun_noname; 1313 bcopy(sa, *nam, sa->sa_len); 1314 UNP_PCB_UNLOCK(unp); 1315 return (0); 1316 } 1317 1318 static struct pr_usrreqs uipc_usrreqs_dgram = { 1319 .pru_abort = uipc_abort, 1320 .pru_accept = uipc_accept, 1321 .pru_attach = uipc_attach, 1322 .pru_bind = uipc_bind, 1323 .pru_bindat = uipc_bindat, 1324 .pru_connect = uipc_connect, 1325 .pru_connectat = uipc_connectat, 1326 .pru_connect2 = uipc_connect2, 1327 .pru_detach = uipc_detach, 1328 .pru_disconnect = uipc_disconnect, 1329 .pru_listen = uipc_listen, 1330 .pru_peeraddr = uipc_peeraddr, 1331 .pru_rcvd = uipc_rcvd, 1332 .pru_send = uipc_send, 1333 .pru_sense = uipc_sense, 1334 .pru_shutdown = uipc_shutdown, 1335 .pru_sockaddr = uipc_sockaddr, 1336 .pru_soreceive = soreceive_dgram, 1337 .pru_close = uipc_close, 1338 }; 1339 1340 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1341 .pru_abort = uipc_abort, 1342 .pru_accept = uipc_accept, 1343 .pru_attach = uipc_attach, 1344 .pru_bind = uipc_bind, 1345 .pru_bindat = uipc_bindat, 1346 .pru_connect = uipc_connect, 1347 .pru_connectat = uipc_connectat, 1348 .pru_connect2 = uipc_connect2, 1349 .pru_detach = uipc_detach, 1350 .pru_disconnect = uipc_disconnect, 1351 .pru_listen = uipc_listen, 1352 .pru_peeraddr = uipc_peeraddr, 1353 .pru_rcvd = uipc_rcvd, 1354 .pru_send = uipc_send, 1355 .pru_sense = uipc_sense, 1356 .pru_shutdown = uipc_shutdown, 1357 .pru_sockaddr = uipc_sockaddr, 1358 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1359 .pru_close = uipc_close, 1360 }; 1361 1362 static struct pr_usrreqs uipc_usrreqs_stream = { 1363 .pru_abort = uipc_abort, 1364 .pru_accept = uipc_accept, 1365 .pru_attach = uipc_attach, 1366 .pru_bind = uipc_bind, 1367 .pru_bindat = uipc_bindat, 1368 .pru_connect = uipc_connect, 1369 .pru_connectat = uipc_connectat, 1370 .pru_connect2 = uipc_connect2, 1371 .pru_detach = uipc_detach, 1372 .pru_disconnect = uipc_disconnect, 1373 .pru_listen = uipc_listen, 1374 .pru_peeraddr = uipc_peeraddr, 1375 .pru_rcvd = uipc_rcvd, 1376 .pru_send = uipc_send, 1377 .pru_ready = uipc_ready, 1378 .pru_sense = uipc_sense, 1379 .pru_shutdown = uipc_shutdown, 1380 .pru_sockaddr = uipc_sockaddr, 1381 .pru_soreceive = soreceive_generic, 1382 .pru_close = uipc_close, 1383 }; 1384 1385 static int 1386 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1387 { 1388 struct unpcb *unp; 1389 struct xucred xu; 1390 int error, optval; 1391 1392 if (sopt->sopt_level != SOL_LOCAL) 1393 return (EINVAL); 1394 1395 unp = sotounpcb(so); 1396 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1397 error = 0; 1398 switch (sopt->sopt_dir) { 1399 case SOPT_GET: 1400 switch (sopt->sopt_name) { 1401 case LOCAL_PEERCRED: 1402 UNP_PCB_LOCK(unp); 1403 if (unp->unp_flags & UNP_HAVEPC) 1404 xu = unp->unp_peercred; 1405 else { 1406 if (so->so_type == SOCK_STREAM) 1407 error = ENOTCONN; 1408 else 1409 error = EINVAL; 1410 } 1411 UNP_PCB_UNLOCK(unp); 1412 if (error == 0) 1413 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1414 break; 1415 1416 case LOCAL_CREDS: 1417 /* Unlocked read. */ 1418 optval = unp->unp_flags & UNP_WANTCRED_ONESHOT ? 1 : 0; 1419 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1420 break; 1421 1422 case LOCAL_CREDS_PERSISTENT: 1423 /* Unlocked read. */ 1424 optval = unp->unp_flags & UNP_WANTCRED_ALWAYS ? 1 : 0; 1425 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1426 break; 1427 1428 case LOCAL_CONNWAIT: 1429 /* Unlocked read. */ 1430 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1431 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1432 break; 1433 1434 default: 1435 error = EOPNOTSUPP; 1436 break; 1437 } 1438 break; 1439 1440 case SOPT_SET: 1441 switch (sopt->sopt_name) { 1442 case LOCAL_CREDS: 1443 case LOCAL_CREDS_PERSISTENT: 1444 case LOCAL_CONNWAIT: 1445 error = sooptcopyin(sopt, &optval, sizeof(optval), 1446 sizeof(optval)); 1447 if (error) 1448 break; 1449 1450 #define OPTSET(bit, exclusive) do { \ 1451 UNP_PCB_LOCK(unp); \ 1452 if (optval) { \ 1453 if ((unp->unp_flags & (exclusive)) != 0) { \ 1454 UNP_PCB_UNLOCK(unp); \ 1455 error = EINVAL; \ 1456 break; \ 1457 } \ 1458 unp->unp_flags |= (bit); \ 1459 } else \ 1460 unp->unp_flags &= ~(bit); \ 1461 UNP_PCB_UNLOCK(unp); \ 1462 } while (0) 1463 1464 switch (sopt->sopt_name) { 1465 case LOCAL_CREDS: 1466 OPTSET(UNP_WANTCRED_ONESHOT, UNP_WANTCRED_ALWAYS); 1467 break; 1468 1469 case LOCAL_CREDS_PERSISTENT: 1470 OPTSET(UNP_WANTCRED_ALWAYS, UNP_WANTCRED_ONESHOT); 1471 break; 1472 1473 case LOCAL_CONNWAIT: 1474 OPTSET(UNP_CONNWAIT, 0); 1475 break; 1476 1477 default: 1478 break; 1479 } 1480 break; 1481 #undef OPTSET 1482 default: 1483 error = ENOPROTOOPT; 1484 break; 1485 } 1486 break; 1487 1488 default: 1489 error = EOPNOTSUPP; 1490 break; 1491 } 1492 return (error); 1493 } 1494 1495 static int 1496 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1497 { 1498 1499 return (unp_connectat(AT_FDCWD, so, nam, td)); 1500 } 1501 1502 static int 1503 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1504 struct thread *td) 1505 { 1506 struct mtx *vplock; 1507 struct sockaddr_un *soun; 1508 struct vnode *vp; 1509 struct socket *so2; 1510 struct unpcb *unp, *unp2, *unp3; 1511 struct nameidata nd; 1512 char buf[SOCK_MAXADDRLEN]; 1513 struct sockaddr *sa; 1514 cap_rights_t rights; 1515 int error, len; 1516 bool connreq; 1517 1518 if (nam->sa_family != AF_UNIX) 1519 return (EAFNOSUPPORT); 1520 if (nam->sa_len > sizeof(struct sockaddr_un)) 1521 return (EINVAL); 1522 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1523 if (len <= 0) 1524 return (EINVAL); 1525 soun = (struct sockaddr_un *)nam; 1526 bcopy(soun->sun_path, buf, len); 1527 buf[len] = 0; 1528 1529 error = 0; 1530 unp = sotounpcb(so); 1531 UNP_PCB_LOCK(unp); 1532 for (;;) { 1533 /* 1534 * Wait for connection state to stabilize. If a connection 1535 * already exists, give up. For datagram sockets, which permit 1536 * multiple consecutive connect(2) calls, upper layers are 1537 * responsible for disconnecting in advance of a subsequent 1538 * connect(2), but this is not synchronized with PCB connection 1539 * state. 1540 * 1541 * Also make sure that no threads are currently attempting to 1542 * lock the peer socket, to ensure that unp_conn cannot 1543 * transition between two valid sockets while locks are dropped. 1544 */ 1545 if (SOLISTENING(so)) 1546 error = EOPNOTSUPP; 1547 else if (unp->unp_conn != NULL) 1548 error = EISCONN; 1549 else if ((unp->unp_flags & UNP_CONNECTING) != 0) { 1550 error = EALREADY; 1551 } 1552 if (error != 0) { 1553 UNP_PCB_UNLOCK(unp); 1554 return (error); 1555 } 1556 if (unp->unp_pairbusy > 0) { 1557 unp->unp_flags |= UNP_WAITING; 1558 mtx_sleep(unp, UNP_PCB_LOCKPTR(unp), 0, "unpeer", 0); 1559 continue; 1560 } 1561 break; 1562 } 1563 unp->unp_flags |= UNP_CONNECTING; 1564 UNP_PCB_UNLOCK(unp); 1565 1566 connreq = (so->so_proto->pr_flags & PR_CONNREQUIRED) != 0; 1567 if (connreq) 1568 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1569 else 1570 sa = NULL; 1571 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1572 UIO_SYSSPACE, buf, fd, cap_rights_init_one(&rights, CAP_CONNECTAT)); 1573 error = namei(&nd); 1574 if (error) 1575 vp = NULL; 1576 else 1577 vp = nd.ni_vp; 1578 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1579 NDFREE_NOTHING(&nd); 1580 if (error) 1581 goto bad; 1582 1583 if (vp->v_type != VSOCK) { 1584 error = ENOTSOCK; 1585 goto bad; 1586 } 1587 #ifdef MAC 1588 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1589 if (error) 1590 goto bad; 1591 #endif 1592 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1593 if (error) 1594 goto bad; 1595 1596 unp = sotounpcb(so); 1597 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1598 1599 vplock = mtx_pool_find(mtxpool_sleep, vp); 1600 mtx_lock(vplock); 1601 VOP_UNP_CONNECT(vp, &unp2); 1602 if (unp2 == NULL) { 1603 error = ECONNREFUSED; 1604 goto bad2; 1605 } 1606 so2 = unp2->unp_socket; 1607 if (so->so_type != so2->so_type) { 1608 error = EPROTOTYPE; 1609 goto bad2; 1610 } 1611 if (connreq) { 1612 if (SOLISTENING(so2)) { 1613 CURVNET_SET(so2->so_vnet); 1614 so2 = sonewconn(so2, 0); 1615 CURVNET_RESTORE(); 1616 } else 1617 so2 = NULL; 1618 if (so2 == NULL) { 1619 error = ECONNREFUSED; 1620 goto bad2; 1621 } 1622 unp3 = sotounpcb(so2); 1623 unp_pcb_lock_pair(unp2, unp3); 1624 if (unp2->unp_addr != NULL) { 1625 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1626 unp3->unp_addr = (struct sockaddr_un *) sa; 1627 sa = NULL; 1628 } 1629 1630 unp_copy_peercred(td, unp3, unp, unp2); 1631 1632 UNP_PCB_UNLOCK(unp2); 1633 unp2 = unp3; 1634 1635 /* 1636 * It is safe to block on the PCB lock here since unp2 is 1637 * nascent and cannot be connected to any other sockets. 1638 */ 1639 UNP_PCB_LOCK(unp); 1640 #ifdef MAC 1641 mac_socketpeer_set_from_socket(so, so2); 1642 mac_socketpeer_set_from_socket(so2, so); 1643 #endif 1644 } else { 1645 unp_pcb_lock_pair(unp, unp2); 1646 } 1647 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1648 sotounpcb(so2) == unp2, 1649 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1650 error = unp_connect2(so, so2, PRU_CONNECT); 1651 unp_pcb_unlock_pair(unp, unp2); 1652 bad2: 1653 mtx_unlock(vplock); 1654 bad: 1655 if (vp != NULL) { 1656 vput(vp); 1657 } 1658 free(sa, M_SONAME); 1659 UNP_PCB_LOCK(unp); 1660 KASSERT((unp->unp_flags & UNP_CONNECTING) != 0, 1661 ("%s: unp %p has UNP_CONNECTING clear", __func__, unp)); 1662 unp->unp_flags &= ~UNP_CONNECTING; 1663 UNP_PCB_UNLOCK(unp); 1664 return (error); 1665 } 1666 1667 /* 1668 * Set socket peer credentials at connection time. 1669 * 1670 * The client's PCB credentials are copied from its process structure. The 1671 * server's PCB credentials are copied from the socket on which it called 1672 * listen(2). uipc_listen cached that process's credentials at the time. 1673 */ 1674 void 1675 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 1676 struct unpcb *server_unp, struct unpcb *listen_unp) 1677 { 1678 cru2xt(td, &client_unp->unp_peercred); 1679 client_unp->unp_flags |= UNP_HAVEPC; 1680 1681 memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred, 1682 sizeof(server_unp->unp_peercred)); 1683 server_unp->unp_flags |= UNP_HAVEPC; 1684 client_unp->unp_flags |= (listen_unp->unp_flags & UNP_WANTCRED_MASK); 1685 } 1686 1687 static int 1688 unp_connect2(struct socket *so, struct socket *so2, int req) 1689 { 1690 struct unpcb *unp; 1691 struct unpcb *unp2; 1692 1693 unp = sotounpcb(so); 1694 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1695 unp2 = sotounpcb(so2); 1696 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1697 1698 UNP_PCB_LOCK_ASSERT(unp); 1699 UNP_PCB_LOCK_ASSERT(unp2); 1700 KASSERT(unp->unp_conn == NULL, 1701 ("%s: socket %p is already connected", __func__, unp)); 1702 1703 if (so2->so_type != so->so_type) 1704 return (EPROTOTYPE); 1705 unp->unp_conn = unp2; 1706 unp_pcb_hold(unp2); 1707 unp_pcb_hold(unp); 1708 switch (so->so_type) { 1709 case SOCK_DGRAM: 1710 UNP_REF_LIST_LOCK(); 1711 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1712 UNP_REF_LIST_UNLOCK(); 1713 soisconnected(so); 1714 break; 1715 1716 case SOCK_STREAM: 1717 case SOCK_SEQPACKET: 1718 KASSERT(unp2->unp_conn == NULL, 1719 ("%s: socket %p is already connected", __func__, unp2)); 1720 unp2->unp_conn = unp; 1721 if (req == PRU_CONNECT && 1722 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1723 soisconnecting(so); 1724 else 1725 soisconnected(so); 1726 soisconnected(so2); 1727 break; 1728 1729 default: 1730 panic("unp_connect2"); 1731 } 1732 return (0); 1733 } 1734 1735 static void 1736 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1737 { 1738 struct socket *so, *so2; 1739 #ifdef INVARIANTS 1740 struct unpcb *unptmp; 1741 #endif 1742 1743 UNP_PCB_LOCK_ASSERT(unp); 1744 UNP_PCB_LOCK_ASSERT(unp2); 1745 KASSERT(unp->unp_conn == unp2, 1746 ("%s: unpcb %p is not connected to %p", __func__, unp, unp2)); 1747 1748 unp->unp_conn = NULL; 1749 so = unp->unp_socket; 1750 so2 = unp2->unp_socket; 1751 switch (unp->unp_socket->so_type) { 1752 case SOCK_DGRAM: 1753 UNP_REF_LIST_LOCK(); 1754 #ifdef INVARIANTS 1755 LIST_FOREACH(unptmp, &unp2->unp_refs, unp_reflink) { 1756 if (unptmp == unp) 1757 break; 1758 } 1759 KASSERT(unptmp != NULL, 1760 ("%s: %p not found in reflist of %p", __func__, unp, unp2)); 1761 #endif 1762 LIST_REMOVE(unp, unp_reflink); 1763 UNP_REF_LIST_UNLOCK(); 1764 if (so) { 1765 SOCK_LOCK(so); 1766 so->so_state &= ~SS_ISCONNECTED; 1767 SOCK_UNLOCK(so); 1768 } 1769 break; 1770 1771 case SOCK_STREAM: 1772 case SOCK_SEQPACKET: 1773 if (so) 1774 soisdisconnected(so); 1775 MPASS(unp2->unp_conn == unp); 1776 unp2->unp_conn = NULL; 1777 if (so2) 1778 soisdisconnected(so2); 1779 break; 1780 } 1781 1782 if (unp == unp2) { 1783 unp_pcb_rele_notlast(unp); 1784 if (!unp_pcb_rele(unp)) 1785 UNP_PCB_UNLOCK(unp); 1786 } else { 1787 if (!unp_pcb_rele(unp)) 1788 UNP_PCB_UNLOCK(unp); 1789 if (!unp_pcb_rele(unp2)) 1790 UNP_PCB_UNLOCK(unp2); 1791 } 1792 } 1793 1794 /* 1795 * unp_pcblist() walks the global list of struct unpcb's to generate a 1796 * pointer list, bumping the refcount on each unpcb. It then copies them out 1797 * sequentially, validating the generation number on each to see if it has 1798 * been detached. All of this is necessary because copyout() may sleep on 1799 * disk I/O. 1800 */ 1801 static int 1802 unp_pcblist(SYSCTL_HANDLER_ARGS) 1803 { 1804 struct unpcb *unp, **unp_list; 1805 unp_gen_t gencnt; 1806 struct xunpgen *xug; 1807 struct unp_head *head; 1808 struct xunpcb *xu; 1809 u_int i; 1810 int error, n; 1811 1812 switch ((intptr_t)arg1) { 1813 case SOCK_STREAM: 1814 head = &unp_shead; 1815 break; 1816 1817 case SOCK_DGRAM: 1818 head = &unp_dhead; 1819 break; 1820 1821 case SOCK_SEQPACKET: 1822 head = &unp_sphead; 1823 break; 1824 1825 default: 1826 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1827 } 1828 1829 /* 1830 * The process of preparing the PCB list is too time-consuming and 1831 * resource-intensive to repeat twice on every request. 1832 */ 1833 if (req->oldptr == NULL) { 1834 n = unp_count; 1835 req->oldidx = 2 * (sizeof *xug) 1836 + (n + n/8) * sizeof(struct xunpcb); 1837 return (0); 1838 } 1839 1840 if (req->newptr != NULL) 1841 return (EPERM); 1842 1843 /* 1844 * OK, now we're committed to doing something. 1845 */ 1846 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK | M_ZERO); 1847 UNP_LINK_RLOCK(); 1848 gencnt = unp_gencnt; 1849 n = unp_count; 1850 UNP_LINK_RUNLOCK(); 1851 1852 xug->xug_len = sizeof *xug; 1853 xug->xug_count = n; 1854 xug->xug_gen = gencnt; 1855 xug->xug_sogen = so_gencnt; 1856 error = SYSCTL_OUT(req, xug, sizeof *xug); 1857 if (error) { 1858 free(xug, M_TEMP); 1859 return (error); 1860 } 1861 1862 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1863 1864 UNP_LINK_RLOCK(); 1865 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1866 unp = LIST_NEXT(unp, unp_link)) { 1867 UNP_PCB_LOCK(unp); 1868 if (unp->unp_gencnt <= gencnt) { 1869 if (cr_cansee(req->td->td_ucred, 1870 unp->unp_socket->so_cred)) { 1871 UNP_PCB_UNLOCK(unp); 1872 continue; 1873 } 1874 unp_list[i++] = unp; 1875 unp_pcb_hold(unp); 1876 } 1877 UNP_PCB_UNLOCK(unp); 1878 } 1879 UNP_LINK_RUNLOCK(); 1880 n = i; /* In case we lost some during malloc. */ 1881 1882 error = 0; 1883 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1884 for (i = 0; i < n; i++) { 1885 unp = unp_list[i]; 1886 UNP_PCB_LOCK(unp); 1887 if (unp_pcb_rele(unp)) 1888 continue; 1889 1890 if (unp->unp_gencnt <= gencnt) { 1891 xu->xu_len = sizeof *xu; 1892 xu->xu_unpp = (uintptr_t)unp; 1893 /* 1894 * XXX - need more locking here to protect against 1895 * connect/disconnect races for SMP. 1896 */ 1897 if (unp->unp_addr != NULL) 1898 bcopy(unp->unp_addr, &xu->xu_addr, 1899 unp->unp_addr->sun_len); 1900 else 1901 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1902 if (unp->unp_conn != NULL && 1903 unp->unp_conn->unp_addr != NULL) 1904 bcopy(unp->unp_conn->unp_addr, 1905 &xu->xu_caddr, 1906 unp->unp_conn->unp_addr->sun_len); 1907 else 1908 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1909 xu->unp_vnode = (uintptr_t)unp->unp_vnode; 1910 xu->unp_conn = (uintptr_t)unp->unp_conn; 1911 xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs); 1912 xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink); 1913 xu->unp_gencnt = unp->unp_gencnt; 1914 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1915 UNP_PCB_UNLOCK(unp); 1916 error = SYSCTL_OUT(req, xu, sizeof *xu); 1917 } else { 1918 UNP_PCB_UNLOCK(unp); 1919 } 1920 } 1921 free(xu, M_TEMP); 1922 if (!error) { 1923 /* 1924 * Give the user an updated idea of our state. If the 1925 * generation differs from what we told her before, she knows 1926 * that something happened while we were processing this 1927 * request, and it might be necessary to retry. 1928 */ 1929 xug->xug_gen = unp_gencnt; 1930 xug->xug_sogen = so_gencnt; 1931 xug->xug_count = unp_count; 1932 error = SYSCTL_OUT(req, xug, sizeof *xug); 1933 } 1934 free(unp_list, M_TEMP); 1935 free(xug, M_TEMP); 1936 return (error); 1937 } 1938 1939 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, 1940 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1941 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1942 "List of active local datagram sockets"); 1943 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, 1944 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1945 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1946 "List of active local stream sockets"); 1947 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1948 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1949 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1950 "List of active local seqpacket sockets"); 1951 1952 static void 1953 unp_shutdown(struct unpcb *unp) 1954 { 1955 struct unpcb *unp2; 1956 struct socket *so; 1957 1958 UNP_PCB_LOCK_ASSERT(unp); 1959 1960 unp2 = unp->unp_conn; 1961 if ((unp->unp_socket->so_type == SOCK_STREAM || 1962 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1963 so = unp2->unp_socket; 1964 if (so != NULL) 1965 socantrcvmore(so); 1966 } 1967 } 1968 1969 static void 1970 unp_drop(struct unpcb *unp) 1971 { 1972 struct socket *so; 1973 struct unpcb *unp2; 1974 1975 /* 1976 * Regardless of whether the socket's peer dropped the connection 1977 * with this socket by aborting or disconnecting, POSIX requires 1978 * that ECONNRESET is returned. 1979 */ 1980 1981 UNP_PCB_LOCK(unp); 1982 so = unp->unp_socket; 1983 if (so) 1984 so->so_error = ECONNRESET; 1985 if ((unp2 = unp_pcb_lock_peer(unp)) != NULL) { 1986 /* Last reference dropped in unp_disconnect(). */ 1987 unp_pcb_rele_notlast(unp); 1988 unp_disconnect(unp, unp2); 1989 } else if (!unp_pcb_rele(unp)) { 1990 UNP_PCB_UNLOCK(unp); 1991 } 1992 } 1993 1994 static void 1995 unp_freerights(struct filedescent **fdep, int fdcount) 1996 { 1997 struct file *fp; 1998 int i; 1999 2000 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 2001 2002 for (i = 0; i < fdcount; i++) { 2003 fp = fdep[i]->fde_file; 2004 filecaps_free(&fdep[i]->fde_caps); 2005 unp_discard(fp); 2006 } 2007 free(fdep[0], M_FILECAPS); 2008 } 2009 2010 static int 2011 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 2012 { 2013 struct thread *td = curthread; /* XXX */ 2014 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2015 int i; 2016 int *fdp; 2017 struct filedesc *fdesc = td->td_proc->p_fd; 2018 struct filedescent **fdep; 2019 void *data; 2020 socklen_t clen = control->m_len, datalen; 2021 int error, newfds; 2022 u_int newlen; 2023 2024 UNP_LINK_UNLOCK_ASSERT(); 2025 2026 error = 0; 2027 if (controlp != NULL) /* controlp == NULL => free control messages */ 2028 *controlp = NULL; 2029 while (cm != NULL) { 2030 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 2031 error = EINVAL; 2032 break; 2033 } 2034 data = CMSG_DATA(cm); 2035 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2036 if (cm->cmsg_level == SOL_SOCKET 2037 && cm->cmsg_type == SCM_RIGHTS) { 2038 newfds = datalen / sizeof(*fdep); 2039 if (newfds == 0) 2040 goto next; 2041 fdep = data; 2042 2043 /* If we're not outputting the descriptors free them. */ 2044 if (error || controlp == NULL) { 2045 unp_freerights(fdep, newfds); 2046 goto next; 2047 } 2048 FILEDESC_XLOCK(fdesc); 2049 2050 /* 2051 * Now change each pointer to an fd in the global 2052 * table to an integer that is the index to the local 2053 * fd table entry that we set up to point to the 2054 * global one we are transferring. 2055 */ 2056 newlen = newfds * sizeof(int); 2057 *controlp = sbcreatecontrol(NULL, newlen, 2058 SCM_RIGHTS, SOL_SOCKET); 2059 if (*controlp == NULL) { 2060 FILEDESC_XUNLOCK(fdesc); 2061 error = E2BIG; 2062 unp_freerights(fdep, newfds); 2063 goto next; 2064 } 2065 2066 fdp = (int *) 2067 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2068 if (fdallocn(td, 0, fdp, newfds) != 0) { 2069 FILEDESC_XUNLOCK(fdesc); 2070 error = EMSGSIZE; 2071 unp_freerights(fdep, newfds); 2072 m_freem(*controlp); 2073 *controlp = NULL; 2074 goto next; 2075 } 2076 for (i = 0; i < newfds; i++, fdp++) { 2077 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2078 (flags & MSG_CMSG_CLOEXEC) != 0 ? O_CLOEXEC : 0, 2079 &fdep[i]->fde_caps); 2080 unp_externalize_fp(fdep[i]->fde_file); 2081 } 2082 2083 /* 2084 * The new type indicates that the mbuf data refers to 2085 * kernel resources that may need to be released before 2086 * the mbuf is freed. 2087 */ 2088 m_chtype(*controlp, MT_EXTCONTROL); 2089 FILEDESC_XUNLOCK(fdesc); 2090 free(fdep[0], M_FILECAPS); 2091 } else { 2092 /* We can just copy anything else across. */ 2093 if (error || controlp == NULL) 2094 goto next; 2095 *controlp = sbcreatecontrol(NULL, datalen, 2096 cm->cmsg_type, cm->cmsg_level); 2097 if (*controlp == NULL) { 2098 error = ENOBUFS; 2099 goto next; 2100 } 2101 bcopy(data, 2102 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2103 datalen); 2104 } 2105 controlp = &(*controlp)->m_next; 2106 2107 next: 2108 if (CMSG_SPACE(datalen) < clen) { 2109 clen -= CMSG_SPACE(datalen); 2110 cm = (struct cmsghdr *) 2111 ((caddr_t)cm + CMSG_SPACE(datalen)); 2112 } else { 2113 clen = 0; 2114 cm = NULL; 2115 } 2116 } 2117 2118 m_freem(control); 2119 return (error); 2120 } 2121 2122 static void 2123 unp_zone_change(void *tag) 2124 { 2125 2126 uma_zone_set_max(unp_zone, maxsockets); 2127 } 2128 2129 #ifdef INVARIANTS 2130 static void 2131 unp_zdtor(void *mem, int size __unused, void *arg __unused) 2132 { 2133 struct unpcb *unp; 2134 2135 unp = mem; 2136 2137 KASSERT(LIST_EMPTY(&unp->unp_refs), 2138 ("%s: unpcb %p has lingering refs", __func__, unp)); 2139 KASSERT(unp->unp_socket == NULL, 2140 ("%s: unpcb %p has socket backpointer", __func__, unp)); 2141 KASSERT(unp->unp_vnode == NULL, 2142 ("%s: unpcb %p has vnode references", __func__, unp)); 2143 KASSERT(unp->unp_conn == NULL, 2144 ("%s: unpcb %p is still connected", __func__, unp)); 2145 KASSERT(unp->unp_addr == NULL, 2146 ("%s: unpcb %p has leaked addr", __func__, unp)); 2147 } 2148 #endif 2149 2150 static void 2151 unp_init(void) 2152 { 2153 uma_dtor dtor; 2154 2155 #ifdef VIMAGE 2156 if (!IS_DEFAULT_VNET(curvnet)) 2157 return; 2158 #endif 2159 2160 #ifdef INVARIANTS 2161 dtor = unp_zdtor; 2162 #else 2163 dtor = NULL; 2164 #endif 2165 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, dtor, 2166 NULL, NULL, UMA_ALIGN_CACHE, 0); 2167 uma_zone_set_max(unp_zone, maxsockets); 2168 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2169 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2170 NULL, EVENTHANDLER_PRI_ANY); 2171 LIST_INIT(&unp_dhead); 2172 LIST_INIT(&unp_shead); 2173 LIST_INIT(&unp_sphead); 2174 SLIST_INIT(&unp_defers); 2175 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2176 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2177 UNP_LINK_LOCK_INIT(); 2178 UNP_DEFERRED_LOCK_INIT(); 2179 } 2180 2181 static void 2182 unp_internalize_cleanup_rights(struct mbuf *control) 2183 { 2184 struct cmsghdr *cp; 2185 struct mbuf *m; 2186 void *data; 2187 socklen_t datalen; 2188 2189 for (m = control; m != NULL; m = m->m_next) { 2190 cp = mtod(m, struct cmsghdr *); 2191 if (cp->cmsg_level != SOL_SOCKET || 2192 cp->cmsg_type != SCM_RIGHTS) 2193 continue; 2194 data = CMSG_DATA(cp); 2195 datalen = (caddr_t)cp + cp->cmsg_len - (caddr_t)data; 2196 unp_freerights(data, datalen / sizeof(struct filedesc *)); 2197 } 2198 } 2199 2200 static int 2201 unp_internalize(struct mbuf **controlp, struct thread *td) 2202 { 2203 struct mbuf *control, **initial_controlp; 2204 struct proc *p; 2205 struct filedesc *fdesc; 2206 struct bintime *bt; 2207 struct cmsghdr *cm; 2208 struct cmsgcred *cmcred; 2209 struct filedescent *fde, **fdep, *fdev; 2210 struct file *fp; 2211 struct timeval *tv; 2212 struct timespec *ts; 2213 void *data; 2214 socklen_t clen, datalen; 2215 int i, j, error, *fdp, oldfds; 2216 u_int newlen; 2217 2218 UNP_LINK_UNLOCK_ASSERT(); 2219 2220 p = td->td_proc; 2221 fdesc = p->p_fd; 2222 error = 0; 2223 control = *controlp; 2224 clen = control->m_len; 2225 *controlp = NULL; 2226 initial_controlp = controlp; 2227 for (cm = mtod(control, struct cmsghdr *); cm != NULL;) { 2228 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2229 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2230 error = EINVAL; 2231 goto out; 2232 } 2233 data = CMSG_DATA(cm); 2234 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2235 2236 switch (cm->cmsg_type) { 2237 /* 2238 * Fill in credential information. 2239 */ 2240 case SCM_CREDS: 2241 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2242 SCM_CREDS, SOL_SOCKET); 2243 if (*controlp == NULL) { 2244 error = ENOBUFS; 2245 goto out; 2246 } 2247 cmcred = (struct cmsgcred *) 2248 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2249 cmcred->cmcred_pid = p->p_pid; 2250 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2251 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2252 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2253 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2254 CMGROUP_MAX); 2255 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2256 cmcred->cmcred_groups[i] = 2257 td->td_ucred->cr_groups[i]; 2258 break; 2259 2260 case SCM_RIGHTS: 2261 oldfds = datalen / sizeof (int); 2262 if (oldfds == 0) 2263 break; 2264 /* 2265 * Check that all the FDs passed in refer to legal 2266 * files. If not, reject the entire operation. 2267 */ 2268 fdp = data; 2269 FILEDESC_SLOCK(fdesc); 2270 for (i = 0; i < oldfds; i++, fdp++) { 2271 fp = fget_locked(fdesc, *fdp); 2272 if (fp == NULL) { 2273 FILEDESC_SUNLOCK(fdesc); 2274 error = EBADF; 2275 goto out; 2276 } 2277 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2278 FILEDESC_SUNLOCK(fdesc); 2279 error = EOPNOTSUPP; 2280 goto out; 2281 } 2282 } 2283 2284 /* 2285 * Now replace the integer FDs with pointers to the 2286 * file structure and capability rights. 2287 */ 2288 newlen = oldfds * sizeof(fdep[0]); 2289 *controlp = sbcreatecontrol(NULL, newlen, 2290 SCM_RIGHTS, SOL_SOCKET); 2291 if (*controlp == NULL) { 2292 FILEDESC_SUNLOCK(fdesc); 2293 error = E2BIG; 2294 goto out; 2295 } 2296 fdp = data; 2297 for (i = 0; i < oldfds; i++, fdp++) { 2298 if (!fhold(fdesc->fd_ofiles[*fdp].fde_file)) { 2299 fdp = data; 2300 for (j = 0; j < i; j++, fdp++) { 2301 fdrop(fdesc->fd_ofiles[*fdp]. 2302 fde_file, td); 2303 } 2304 FILEDESC_SUNLOCK(fdesc); 2305 error = EBADF; 2306 goto out; 2307 } 2308 } 2309 fdp = data; 2310 fdep = (struct filedescent **) 2311 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2312 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2313 M_WAITOK); 2314 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2315 fde = &fdesc->fd_ofiles[*fdp]; 2316 fdep[i] = fdev; 2317 fdep[i]->fde_file = fde->fde_file; 2318 filecaps_copy(&fde->fde_caps, 2319 &fdep[i]->fde_caps, true); 2320 unp_internalize_fp(fdep[i]->fde_file); 2321 } 2322 FILEDESC_SUNLOCK(fdesc); 2323 break; 2324 2325 case SCM_TIMESTAMP: 2326 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2327 SCM_TIMESTAMP, SOL_SOCKET); 2328 if (*controlp == NULL) { 2329 error = ENOBUFS; 2330 goto out; 2331 } 2332 tv = (struct timeval *) 2333 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2334 microtime(tv); 2335 break; 2336 2337 case SCM_BINTIME: 2338 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2339 SCM_BINTIME, SOL_SOCKET); 2340 if (*controlp == NULL) { 2341 error = ENOBUFS; 2342 goto out; 2343 } 2344 bt = (struct bintime *) 2345 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2346 bintime(bt); 2347 break; 2348 2349 case SCM_REALTIME: 2350 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2351 SCM_REALTIME, SOL_SOCKET); 2352 if (*controlp == NULL) { 2353 error = ENOBUFS; 2354 goto out; 2355 } 2356 ts = (struct timespec *) 2357 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2358 nanotime(ts); 2359 break; 2360 2361 case SCM_MONOTONIC: 2362 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2363 SCM_MONOTONIC, SOL_SOCKET); 2364 if (*controlp == NULL) { 2365 error = ENOBUFS; 2366 goto out; 2367 } 2368 ts = (struct timespec *) 2369 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2370 nanouptime(ts); 2371 break; 2372 2373 default: 2374 error = EINVAL; 2375 goto out; 2376 } 2377 2378 if (*controlp != NULL) 2379 controlp = &(*controlp)->m_next; 2380 if (CMSG_SPACE(datalen) < clen) { 2381 clen -= CMSG_SPACE(datalen); 2382 cm = (struct cmsghdr *) 2383 ((caddr_t)cm + CMSG_SPACE(datalen)); 2384 } else { 2385 clen = 0; 2386 cm = NULL; 2387 } 2388 } 2389 2390 out: 2391 if (error != 0 && initial_controlp != NULL) 2392 unp_internalize_cleanup_rights(*initial_controlp); 2393 m_freem(control); 2394 return (error); 2395 } 2396 2397 static struct mbuf * 2398 unp_addsockcred(struct thread *td, struct mbuf *control, int mode) 2399 { 2400 struct mbuf *m, *n, *n_prev; 2401 const struct cmsghdr *cm; 2402 int ngroups, i, cmsgtype; 2403 size_t ctrlsz; 2404 2405 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2406 if (mode & UNP_WANTCRED_ALWAYS) { 2407 ctrlsz = SOCKCRED2SIZE(ngroups); 2408 cmsgtype = SCM_CREDS2; 2409 } else { 2410 ctrlsz = SOCKCREDSIZE(ngroups); 2411 cmsgtype = SCM_CREDS; 2412 } 2413 2414 m = sbcreatecontrol(NULL, ctrlsz, cmsgtype, SOL_SOCKET); 2415 if (m == NULL) 2416 return (control); 2417 2418 if (mode & UNP_WANTCRED_ALWAYS) { 2419 struct sockcred2 *sc; 2420 2421 sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *)); 2422 sc->sc_version = 0; 2423 sc->sc_pid = td->td_proc->p_pid; 2424 sc->sc_uid = td->td_ucred->cr_ruid; 2425 sc->sc_euid = td->td_ucred->cr_uid; 2426 sc->sc_gid = td->td_ucred->cr_rgid; 2427 sc->sc_egid = td->td_ucred->cr_gid; 2428 sc->sc_ngroups = ngroups; 2429 for (i = 0; i < sc->sc_ngroups; i++) 2430 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2431 } else { 2432 struct sockcred *sc; 2433 2434 sc = (void *)CMSG_DATA(mtod(m, struct cmsghdr *)); 2435 sc->sc_uid = td->td_ucred->cr_ruid; 2436 sc->sc_euid = td->td_ucred->cr_uid; 2437 sc->sc_gid = td->td_ucred->cr_rgid; 2438 sc->sc_egid = td->td_ucred->cr_gid; 2439 sc->sc_ngroups = ngroups; 2440 for (i = 0; i < sc->sc_ngroups; i++) 2441 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2442 } 2443 2444 /* 2445 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2446 * created SCM_CREDS control message (struct sockcred) has another 2447 * format. 2448 */ 2449 if (control != NULL && cmsgtype == SCM_CREDS) 2450 for (n = control, n_prev = NULL; n != NULL;) { 2451 cm = mtod(n, struct cmsghdr *); 2452 if (cm->cmsg_level == SOL_SOCKET && 2453 cm->cmsg_type == SCM_CREDS) { 2454 if (n_prev == NULL) 2455 control = n->m_next; 2456 else 2457 n_prev->m_next = n->m_next; 2458 n = m_free(n); 2459 } else { 2460 n_prev = n; 2461 n = n->m_next; 2462 } 2463 } 2464 2465 /* Prepend it to the head. */ 2466 m->m_next = control; 2467 return (m); 2468 } 2469 2470 static struct unpcb * 2471 fptounp(struct file *fp) 2472 { 2473 struct socket *so; 2474 2475 if (fp->f_type != DTYPE_SOCKET) 2476 return (NULL); 2477 if ((so = fp->f_data) == NULL) 2478 return (NULL); 2479 if (so->so_proto->pr_domain != &localdomain) 2480 return (NULL); 2481 return sotounpcb(so); 2482 } 2483 2484 static void 2485 unp_discard(struct file *fp) 2486 { 2487 struct unp_defer *dr; 2488 2489 if (unp_externalize_fp(fp)) { 2490 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2491 dr->ud_fp = fp; 2492 UNP_DEFERRED_LOCK(); 2493 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2494 UNP_DEFERRED_UNLOCK(); 2495 atomic_add_int(&unp_defers_count, 1); 2496 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2497 } else 2498 closef_nothread(fp); 2499 } 2500 2501 static void 2502 unp_process_defers(void *arg __unused, int pending) 2503 { 2504 struct unp_defer *dr; 2505 SLIST_HEAD(, unp_defer) drl; 2506 int count; 2507 2508 SLIST_INIT(&drl); 2509 for (;;) { 2510 UNP_DEFERRED_LOCK(); 2511 if (SLIST_FIRST(&unp_defers) == NULL) { 2512 UNP_DEFERRED_UNLOCK(); 2513 break; 2514 } 2515 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2516 UNP_DEFERRED_UNLOCK(); 2517 count = 0; 2518 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2519 SLIST_REMOVE_HEAD(&drl, ud_link); 2520 closef_nothread(dr->ud_fp); 2521 free(dr, M_TEMP); 2522 count++; 2523 } 2524 atomic_add_int(&unp_defers_count, -count); 2525 } 2526 } 2527 2528 static void 2529 unp_internalize_fp(struct file *fp) 2530 { 2531 struct unpcb *unp; 2532 2533 UNP_LINK_WLOCK(); 2534 if ((unp = fptounp(fp)) != NULL) { 2535 unp->unp_file = fp; 2536 unp->unp_msgcount++; 2537 } 2538 unp_rights++; 2539 UNP_LINK_WUNLOCK(); 2540 } 2541 2542 static int 2543 unp_externalize_fp(struct file *fp) 2544 { 2545 struct unpcb *unp; 2546 int ret; 2547 2548 UNP_LINK_WLOCK(); 2549 if ((unp = fptounp(fp)) != NULL) { 2550 unp->unp_msgcount--; 2551 ret = 1; 2552 } else 2553 ret = 0; 2554 unp_rights--; 2555 UNP_LINK_WUNLOCK(); 2556 return (ret); 2557 } 2558 2559 /* 2560 * unp_defer indicates whether additional work has been defered for a future 2561 * pass through unp_gc(). It is thread local and does not require explicit 2562 * synchronization. 2563 */ 2564 static int unp_marked; 2565 2566 static void 2567 unp_remove_dead_ref(struct filedescent **fdep, int fdcount) 2568 { 2569 struct unpcb *unp; 2570 struct file *fp; 2571 int i; 2572 2573 /* 2574 * This function can only be called from the gc task. 2575 */ 2576 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2577 ("%s: not on gc callout", __func__)); 2578 UNP_LINK_LOCK_ASSERT(); 2579 2580 for (i = 0; i < fdcount; i++) { 2581 fp = fdep[i]->fde_file; 2582 if ((unp = fptounp(fp)) == NULL) 2583 continue; 2584 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2585 continue; 2586 unp->unp_gcrefs--; 2587 } 2588 } 2589 2590 static void 2591 unp_restore_undead_ref(struct filedescent **fdep, int fdcount) 2592 { 2593 struct unpcb *unp; 2594 struct file *fp; 2595 int i; 2596 2597 /* 2598 * This function can only be called from the gc task. 2599 */ 2600 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2601 ("%s: not on gc callout", __func__)); 2602 UNP_LINK_LOCK_ASSERT(); 2603 2604 for (i = 0; i < fdcount; i++) { 2605 fp = fdep[i]->fde_file; 2606 if ((unp = fptounp(fp)) == NULL) 2607 continue; 2608 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2609 continue; 2610 unp->unp_gcrefs++; 2611 unp_marked++; 2612 } 2613 } 2614 2615 static void 2616 unp_gc_scan(struct unpcb *unp, void (*op)(struct filedescent **, int)) 2617 { 2618 struct socket *so, *soa; 2619 2620 so = unp->unp_socket; 2621 SOCK_LOCK(so); 2622 if (SOLISTENING(so)) { 2623 /* 2624 * Mark all sockets in our accept queue. 2625 */ 2626 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2627 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2628 continue; 2629 SOCKBUF_LOCK(&soa->so_rcv); 2630 unp_scan(soa->so_rcv.sb_mb, op); 2631 SOCKBUF_UNLOCK(&soa->so_rcv); 2632 } 2633 } else { 2634 /* 2635 * Mark all sockets we reference with RIGHTS. 2636 */ 2637 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2638 SOCKBUF_LOCK(&so->so_rcv); 2639 unp_scan(so->so_rcv.sb_mb, op); 2640 SOCKBUF_UNLOCK(&so->so_rcv); 2641 } 2642 } 2643 SOCK_UNLOCK(so); 2644 } 2645 2646 static int unp_recycled; 2647 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2648 "Number of unreachable sockets claimed by the garbage collector."); 2649 2650 static int unp_taskcount; 2651 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2652 "Number of times the garbage collector has run."); 2653 2654 SYSCTL_UINT(_net_local, OID_AUTO, sockcount, CTLFLAG_RD, &unp_count, 0, 2655 "Number of active local sockets."); 2656 2657 static void 2658 unp_gc(__unused void *arg, int pending) 2659 { 2660 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2661 NULL }; 2662 struct unp_head **head; 2663 struct unp_head unp_deadhead; /* List of potentially-dead sockets. */ 2664 struct file *f, **unref; 2665 struct unpcb *unp, *unptmp; 2666 int i, total, unp_unreachable; 2667 2668 LIST_INIT(&unp_deadhead); 2669 unp_taskcount++; 2670 UNP_LINK_RLOCK(); 2671 /* 2672 * First determine which sockets may be in cycles. 2673 */ 2674 unp_unreachable = 0; 2675 2676 for (head = heads; *head != NULL; head++) 2677 LIST_FOREACH(unp, *head, unp_link) { 2678 KASSERT((unp->unp_gcflag & ~UNPGC_IGNORE_RIGHTS) == 0, 2679 ("%s: unp %p has unexpected gc flags 0x%x", 2680 __func__, unp, (unsigned int)unp->unp_gcflag)); 2681 2682 f = unp->unp_file; 2683 2684 /* 2685 * Check for an unreachable socket potentially in a 2686 * cycle. It must be in a queue as indicated by 2687 * msgcount, and this must equal the file reference 2688 * count. Note that when msgcount is 0 the file is 2689 * NULL. 2690 */ 2691 if (f != NULL && unp->unp_msgcount != 0 && 2692 refcount_load(&f->f_count) == unp->unp_msgcount) { 2693 LIST_INSERT_HEAD(&unp_deadhead, unp, unp_dead); 2694 unp->unp_gcflag |= UNPGC_DEAD; 2695 unp->unp_gcrefs = unp->unp_msgcount; 2696 unp_unreachable++; 2697 } 2698 } 2699 2700 /* 2701 * Scan all sockets previously marked as potentially being in a cycle 2702 * and remove the references each socket holds on any UNPGC_DEAD 2703 * sockets in its queue. After this step, all remaining references on 2704 * sockets marked UNPGC_DEAD should not be part of any cycle. 2705 */ 2706 LIST_FOREACH(unp, &unp_deadhead, unp_dead) 2707 unp_gc_scan(unp, unp_remove_dead_ref); 2708 2709 /* 2710 * If a socket still has a non-negative refcount, it cannot be in a 2711 * cycle. In this case increment refcount of all children iteratively. 2712 * Stop the scan once we do a complete loop without discovering 2713 * a new reachable socket. 2714 */ 2715 do { 2716 unp_marked = 0; 2717 LIST_FOREACH_SAFE(unp, &unp_deadhead, unp_dead, unptmp) 2718 if (unp->unp_gcrefs > 0) { 2719 unp->unp_gcflag &= ~UNPGC_DEAD; 2720 LIST_REMOVE(unp, unp_dead); 2721 KASSERT(unp_unreachable > 0, 2722 ("%s: unp_unreachable underflow.", 2723 __func__)); 2724 unp_unreachable--; 2725 unp_gc_scan(unp, unp_restore_undead_ref); 2726 } 2727 } while (unp_marked); 2728 2729 UNP_LINK_RUNLOCK(); 2730 2731 if (unp_unreachable == 0) 2732 return; 2733 2734 /* 2735 * Allocate space for a local array of dead unpcbs. 2736 * TODO: can this path be simplified by instead using the local 2737 * dead list at unp_deadhead, after taking out references 2738 * on the file object and/or unpcb and dropping the link lock? 2739 */ 2740 unref = malloc(unp_unreachable * sizeof(struct file *), 2741 M_TEMP, M_WAITOK); 2742 2743 /* 2744 * Iterate looking for sockets which have been specifically marked 2745 * as unreachable and store them locally. 2746 */ 2747 UNP_LINK_RLOCK(); 2748 total = 0; 2749 LIST_FOREACH(unp, &unp_deadhead, unp_dead) { 2750 KASSERT((unp->unp_gcflag & UNPGC_DEAD) != 0, 2751 ("%s: unp %p not marked UNPGC_DEAD", __func__, unp)); 2752 unp->unp_gcflag &= ~UNPGC_DEAD; 2753 f = unp->unp_file; 2754 if (unp->unp_msgcount == 0 || f == NULL || 2755 refcount_load(&f->f_count) != unp->unp_msgcount || 2756 !fhold(f)) 2757 continue; 2758 unref[total++] = f; 2759 KASSERT(total <= unp_unreachable, 2760 ("%s: incorrect unreachable count.", __func__)); 2761 } 2762 UNP_LINK_RUNLOCK(); 2763 2764 /* 2765 * Now flush all sockets, free'ing rights. This will free the 2766 * struct files associated with these sockets but leave each socket 2767 * with one remaining ref. 2768 */ 2769 for (i = 0; i < total; i++) { 2770 struct socket *so; 2771 2772 so = unref[i]->f_data; 2773 CURVNET_SET(so->so_vnet); 2774 sorflush(so); 2775 CURVNET_RESTORE(); 2776 } 2777 2778 /* 2779 * And finally release the sockets so they can be reclaimed. 2780 */ 2781 for (i = 0; i < total; i++) 2782 fdrop(unref[i], NULL); 2783 unp_recycled += total; 2784 free(unref, M_TEMP); 2785 } 2786 2787 static void 2788 unp_dispose_mbuf(struct mbuf *m) 2789 { 2790 2791 if (m) 2792 unp_scan(m, unp_freerights); 2793 } 2794 2795 /* 2796 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2797 */ 2798 static void 2799 unp_dispose(struct socket *so) 2800 { 2801 struct unpcb *unp; 2802 2803 unp = sotounpcb(so); 2804 UNP_LINK_WLOCK(); 2805 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2806 UNP_LINK_WUNLOCK(); 2807 if (!SOLISTENING(so)) 2808 unp_dispose_mbuf(so->so_rcv.sb_mb); 2809 } 2810 2811 static void 2812 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2813 { 2814 struct mbuf *m; 2815 struct cmsghdr *cm; 2816 void *data; 2817 socklen_t clen, datalen; 2818 2819 while (m0 != NULL) { 2820 for (m = m0; m; m = m->m_next) { 2821 if (m->m_type != MT_CONTROL) 2822 continue; 2823 2824 cm = mtod(m, struct cmsghdr *); 2825 clen = m->m_len; 2826 2827 while (cm != NULL) { 2828 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2829 break; 2830 2831 data = CMSG_DATA(cm); 2832 datalen = (caddr_t)cm + cm->cmsg_len 2833 - (caddr_t)data; 2834 2835 if (cm->cmsg_level == SOL_SOCKET && 2836 cm->cmsg_type == SCM_RIGHTS) { 2837 (*op)(data, datalen / 2838 sizeof(struct filedescent *)); 2839 } 2840 2841 if (CMSG_SPACE(datalen) < clen) { 2842 clen -= CMSG_SPACE(datalen); 2843 cm = (struct cmsghdr *) 2844 ((caddr_t)cm + CMSG_SPACE(datalen)); 2845 } else { 2846 clen = 0; 2847 cm = NULL; 2848 } 2849 } 2850 } 2851 m0 = m0->m_nextpkt; 2852 } 2853 } 2854 2855 /* 2856 * A helper function called by VFS before socket-type vnode reclamation. 2857 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2858 * use count. 2859 */ 2860 void 2861 vfs_unp_reclaim(struct vnode *vp) 2862 { 2863 struct unpcb *unp; 2864 int active; 2865 struct mtx *vplock; 2866 2867 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2868 KASSERT(vp->v_type == VSOCK, 2869 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2870 2871 active = 0; 2872 vplock = mtx_pool_find(mtxpool_sleep, vp); 2873 mtx_lock(vplock); 2874 VOP_UNP_CONNECT(vp, &unp); 2875 if (unp == NULL) 2876 goto done; 2877 UNP_PCB_LOCK(unp); 2878 if (unp->unp_vnode == vp) { 2879 VOP_UNP_DETACH(vp); 2880 unp->unp_vnode = NULL; 2881 active = 1; 2882 } 2883 UNP_PCB_UNLOCK(unp); 2884 done: 2885 mtx_unlock(vplock); 2886 if (active) 2887 vunref(vp); 2888 } 2889 2890 #ifdef DDB 2891 static void 2892 db_print_indent(int indent) 2893 { 2894 int i; 2895 2896 for (i = 0; i < indent; i++) 2897 db_printf(" "); 2898 } 2899 2900 static void 2901 db_print_unpflags(int unp_flags) 2902 { 2903 int comma; 2904 2905 comma = 0; 2906 if (unp_flags & UNP_HAVEPC) { 2907 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2908 comma = 1; 2909 } 2910 if (unp_flags & UNP_WANTCRED_ALWAYS) { 2911 db_printf("%sUNP_WANTCRED_ALWAYS", comma ? ", " : ""); 2912 comma = 1; 2913 } 2914 if (unp_flags & UNP_WANTCRED_ONESHOT) { 2915 db_printf("%sUNP_WANTCRED_ONESHOT", comma ? ", " : ""); 2916 comma = 1; 2917 } 2918 if (unp_flags & UNP_CONNWAIT) { 2919 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2920 comma = 1; 2921 } 2922 if (unp_flags & UNP_CONNECTING) { 2923 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2924 comma = 1; 2925 } 2926 if (unp_flags & UNP_BINDING) { 2927 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2928 comma = 1; 2929 } 2930 } 2931 2932 static void 2933 db_print_xucred(int indent, struct xucred *xu) 2934 { 2935 int comma, i; 2936 2937 db_print_indent(indent); 2938 db_printf("cr_version: %u cr_uid: %u cr_pid: %d cr_ngroups: %d\n", 2939 xu->cr_version, xu->cr_uid, xu->cr_pid, xu->cr_ngroups); 2940 db_print_indent(indent); 2941 db_printf("cr_groups: "); 2942 comma = 0; 2943 for (i = 0; i < xu->cr_ngroups; i++) { 2944 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2945 comma = 1; 2946 } 2947 db_printf("\n"); 2948 } 2949 2950 static void 2951 db_print_unprefs(int indent, struct unp_head *uh) 2952 { 2953 struct unpcb *unp; 2954 int counter; 2955 2956 counter = 0; 2957 LIST_FOREACH(unp, uh, unp_reflink) { 2958 if (counter % 4 == 0) 2959 db_print_indent(indent); 2960 db_printf("%p ", unp); 2961 if (counter % 4 == 3) 2962 db_printf("\n"); 2963 counter++; 2964 } 2965 if (counter != 0 && counter % 4 != 0) 2966 db_printf("\n"); 2967 } 2968 2969 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2970 { 2971 struct unpcb *unp; 2972 2973 if (!have_addr) { 2974 db_printf("usage: show unpcb <addr>\n"); 2975 return; 2976 } 2977 unp = (struct unpcb *)addr; 2978 2979 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2980 unp->unp_vnode); 2981 2982 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2983 unp->unp_conn); 2984 2985 db_printf("unp_refs:\n"); 2986 db_print_unprefs(2, &unp->unp_refs); 2987 2988 /* XXXRW: Would be nice to print the full address, if any. */ 2989 db_printf("unp_addr: %p\n", unp->unp_addr); 2990 2991 db_printf("unp_gencnt: %llu\n", 2992 (unsigned long long)unp->unp_gencnt); 2993 2994 db_printf("unp_flags: %x (", unp->unp_flags); 2995 db_print_unpflags(unp->unp_flags); 2996 db_printf(")\n"); 2997 2998 db_printf("unp_peercred:\n"); 2999 db_print_xucred(2, &unp->unp_peercred); 3000 3001 db_printf("unp_refcount: %u\n", unp->unp_refcount); 3002 } 3003 #endif 3004