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/fcntl.h> 69 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 70 #include <sys/eventhandler.h> 71 #include <sys/file.h> 72 #include <sys/filedesc.h> 73 #include <sys/kernel.h> 74 #include <sys/lock.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 * Locking key: 110 * (l) Locked using list lock 111 * (g) Locked using linkage lock 112 */ 113 114 static uma_zone_t unp_zone; 115 static unp_gen_t unp_gencnt; /* (l) */ 116 static u_int unp_count; /* (l) Count of local sockets. */ 117 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 118 static int unp_rights; /* (g) File descriptors in flight. */ 119 static struct unp_head unp_shead; /* (l) List of stream sockets. */ 120 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 121 static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */ 122 123 struct unp_defer { 124 SLIST_ENTRY(unp_defer) ud_link; 125 struct file *ud_fp; 126 }; 127 static SLIST_HEAD(, unp_defer) unp_defers; 128 static int unp_defers_count; 129 130 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 131 132 /* 133 * Garbage collection of cyclic file descriptor/socket references occurs 134 * asynchronously in a taskqueue context in order to avoid recursion and 135 * reentrance in the UNIX domain socket, file descriptor, and socket layer 136 * code. See unp_gc() for a full description. 137 */ 138 static struct timeout_task unp_gc_task; 139 140 /* 141 * The close of unix domain sockets attached as SCM_RIGHTS is 142 * postponed to the taskqueue, to avoid arbitrary recursion depth. 143 * The attached sockets might have another sockets attached. 144 */ 145 static struct task unp_defer_task; 146 147 /* 148 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 149 * stream sockets, although the total for sender and receiver is actually 150 * only PIPSIZ. 151 * 152 * Datagram sockets really use the sendspace as the maximum datagram size, 153 * and don't really want to reserve the sendspace. Their recvspace should be 154 * large enough for at least one max-size datagram plus address. 155 */ 156 #ifndef PIPSIZ 157 #define PIPSIZ 8192 158 #endif 159 static u_long unpst_sendspace = PIPSIZ; 160 static u_long unpst_recvspace = PIPSIZ; 161 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 162 static u_long unpdg_recvspace = 4*1024; 163 static u_long unpsp_sendspace = PIPSIZ; /* really max datagram size */ 164 static u_long unpsp_recvspace = PIPSIZ; 165 166 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 167 "Local domain"); 168 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, 169 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 170 "SOCK_STREAM"); 171 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, 172 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 173 "SOCK_DGRAM"); 174 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, 175 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 176 "SOCK_SEQPACKET"); 177 178 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 179 &unpst_sendspace, 0, "Default stream send space."); 180 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 181 &unpst_recvspace, 0, "Default stream receive space."); 182 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 183 &unpdg_sendspace, 0, "Default datagram send space."); 184 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 185 &unpdg_recvspace, 0, "Default datagram receive space."); 186 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW, 187 &unpsp_sendspace, 0, "Default seqpacket send space."); 188 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW, 189 &unpsp_recvspace, 0, "Default seqpacket receive space."); 190 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 191 "File descriptors in flight."); 192 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD, 193 &unp_defers_count, 0, 194 "File descriptors deferred to taskqueue for close."); 195 196 /* 197 * Locking and synchronization: 198 * 199 * Three types of locks exist in the local domain socket implementation: a 200 * a global linkage rwlock, the mtxpool lock, and per-unpcb mutexes. 201 * The linkage lock protects the socket count, global generation number, 202 * and stream/datagram global lists. 203 * 204 * The mtxpool lock protects the vnode from being modified while referenced. 205 * Lock ordering requires that it be acquired before any unpcb locks. 206 * 207 * The unpcb lock (unp_mtx) protects all fields in the unpcb. Of particular 208 * note is that this includes the unp_conn field. So long as the unpcb lock 209 * is held the reference to the unpcb pointed to by unp_conn is valid. If we 210 * require that the unpcb pointed to by unp_conn remain live in cases where 211 * we need to drop the unp_mtx as when we need to acquire the lock for a 212 * second unpcb the caller must first acquire an additional reference on the 213 * second unpcb and then revalidate any state (typically check that unp_conn 214 * is non-NULL) upon requiring the initial unpcb lock. The lock ordering 215 * between unpcbs is the conventional ascending address order. Two helper 216 * routines exist for this: 217 * 218 * - unp_pcb_lock2(unp, unp2) - which just acquires the two locks in the 219 * safe ordering. 220 * 221 * - unp_pcb_owned_lock2(unp, unp2, freed) - the lock for unp is held 222 * when called. If unp is unlocked and unp2 is subsequently freed 223 * freed will be set to 1. 224 * 225 * The helper routines for references are: 226 * 227 * - unp_pcb_hold(unp): Can be called any time we currently hold a valid 228 * reference to unp. 229 * 230 * - unp_pcb_rele(unp): The caller must hold the unp lock. If we are 231 * releasing the last reference, detach must have been called thus 232 * unp->unp_socket be NULL. 233 * 234 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 235 * allocated in pru_attach() and freed in pru_detach(). The validity of that 236 * pointer is an invariant, so no lock is required to dereference the so_pcb 237 * pointer if a valid socket reference is held by the caller. In practice, 238 * this is always true during operations performed on a socket. Each unpcb 239 * has a back-pointer to its socket, unp_socket, which will be stable under 240 * the same circumstances. 241 * 242 * This pointer may only be safely dereferenced as long as a valid reference 243 * to the unpcb is held. Typically, this reference will be from the socket, 244 * or from another unpcb when the referring unpcb's lock is held (in order 245 * that the reference not be invalidated during use). For example, to follow 246 * unp->unp_conn->unp_socket, you need to hold a lock on unp_conn to guarantee 247 * that detach is not run clearing unp_socket. 248 * 249 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 250 * protocols, bind() is a non-atomic operation, and connect() requires 251 * potential sleeping in the protocol, due to potentially waiting on local or 252 * distributed file systems. We try to separate "lookup" operations, which 253 * may sleep, and the IPC operations themselves, which typically can occur 254 * with relative atomicity as locks can be held over the entire operation. 255 * 256 * Another tricky issue is simultaneous multi-threaded or multi-process 257 * access to a single UNIX domain socket. These are handled by the flags 258 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 259 * binding, both of which involve dropping UNIX domain socket locks in order 260 * to perform namei() and other file system operations. 261 */ 262 static struct rwlock unp_link_rwlock; 263 static struct mtx unp_defers_lock; 264 265 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 266 "unp_link_rwlock") 267 268 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 269 RA_LOCKED) 270 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 271 RA_UNLOCKED) 272 273 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 274 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 275 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 276 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 277 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 278 RA_WLOCKED) 279 #define UNP_LINK_WOWNED() rw_wowned(&unp_link_rwlock) 280 281 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \ 282 "unp_defer", NULL, MTX_DEF) 283 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock) 284 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock) 285 286 #define UNP_REF_LIST_LOCK() UNP_DEFERRED_LOCK(); 287 #define UNP_REF_LIST_UNLOCK() UNP_DEFERRED_UNLOCK(); 288 289 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 290 "unp", "unp", \ 291 MTX_DUPOK|MTX_DEF) 292 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 293 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 294 #define UNP_PCB_TRYLOCK(unp) mtx_trylock(&(unp)->unp_mtx) 295 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 296 #define UNP_PCB_OWNED(unp) mtx_owned(&(unp)->unp_mtx) 297 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 298 #define UNP_PCB_UNLOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_NOTOWNED) 299 300 static int uipc_connect2(struct socket *, struct socket *); 301 static int uipc_ctloutput(struct socket *, struct sockopt *); 302 static int unp_connect(struct socket *, struct sockaddr *, 303 struct thread *); 304 static int unp_connectat(int, struct socket *, struct sockaddr *, 305 struct thread *); 306 static int unp_connect2(struct socket *so, struct socket *so2, int); 307 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 308 static void unp_dispose(struct socket *so); 309 static void unp_dispose_mbuf(struct mbuf *); 310 static void unp_shutdown(struct unpcb *); 311 static void unp_drop(struct unpcb *); 312 static void unp_gc(__unused void *, int); 313 static void unp_scan(struct mbuf *, void (*)(struct filedescent **, int)); 314 static void unp_discard(struct file *); 315 static void unp_freerights(struct filedescent **, int); 316 static void unp_init(void); 317 static int unp_internalize(struct mbuf **, struct thread *); 318 static void unp_internalize_fp(struct file *); 319 static int unp_externalize(struct mbuf *, struct mbuf **, int); 320 static int unp_externalize_fp(struct file *); 321 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 322 static void unp_process_defers(void * __unused, int); 323 324 static void 325 unp_pcb_hold(struct unpcb *unp) 326 { 327 MPASS(unp->unp_refcount); 328 refcount_acquire(&unp->unp_refcount); 329 } 330 331 static int 332 unp_pcb_rele(struct unpcb *unp) 333 { 334 int freed; 335 336 UNP_PCB_LOCK_ASSERT(unp); 337 MPASS(unp->unp_refcount); 338 if ((freed = refcount_release(&unp->unp_refcount))) { 339 /* we got here with having detached? */ 340 MPASS(unp->unp_socket == NULL); 341 UNP_PCB_UNLOCK(unp); 342 UNP_PCB_LOCK_DESTROY(unp); 343 uma_zfree(unp_zone, unp); 344 } 345 return (freed); 346 } 347 348 static void 349 unp_pcb_lock2(struct unpcb *unp, struct unpcb *unp2) 350 { 351 MPASS(unp != unp2); 352 UNP_PCB_UNLOCK_ASSERT(unp); 353 UNP_PCB_UNLOCK_ASSERT(unp2); 354 if ((uintptr_t)unp2 > (uintptr_t)unp) { 355 UNP_PCB_LOCK(unp); 356 UNP_PCB_LOCK(unp2); 357 } else { 358 UNP_PCB_LOCK(unp2); 359 UNP_PCB_LOCK(unp); 360 } 361 } 362 363 static __noinline void 364 unp_pcb_owned_lock2_slowpath(struct unpcb *unp, struct unpcb **unp2p, 365 int *freed) 366 { 367 struct unpcb *unp2; 368 369 unp2 = *unp2p; 370 unp_pcb_hold(unp2); 371 UNP_PCB_UNLOCK(unp); 372 UNP_PCB_LOCK(unp2); 373 UNP_PCB_LOCK(unp); 374 *freed = unp_pcb_rele(unp2); 375 if (*freed) 376 *unp2p = NULL; 377 } 378 379 #define unp_pcb_owned_lock2(unp, unp2, freed) do { \ 380 freed = 0; \ 381 UNP_PCB_LOCK_ASSERT(unp); \ 382 UNP_PCB_UNLOCK_ASSERT(unp2); \ 383 MPASS((unp) != (unp2)); \ 384 if (__predict_true(UNP_PCB_TRYLOCK(unp2))) \ 385 break; \ 386 else if ((uintptr_t)(unp2) > (uintptr_t)(unp)) \ 387 UNP_PCB_LOCK(unp2); \ 388 else \ 389 unp_pcb_owned_lock2_slowpath((unp), &(unp2), &freed); \ 390 } while (0) 391 392 /* 393 * Definitions of protocols supported in the LOCAL domain. 394 */ 395 static struct domain localdomain; 396 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 397 static struct pr_usrreqs uipc_usrreqs_seqpacket; 398 static struct protosw localsw[] = { 399 { 400 .pr_type = SOCK_STREAM, 401 .pr_domain = &localdomain, 402 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 403 .pr_ctloutput = &uipc_ctloutput, 404 .pr_usrreqs = &uipc_usrreqs_stream 405 }, 406 { 407 .pr_type = SOCK_DGRAM, 408 .pr_domain = &localdomain, 409 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 410 .pr_ctloutput = &uipc_ctloutput, 411 .pr_usrreqs = &uipc_usrreqs_dgram 412 }, 413 { 414 .pr_type = SOCK_SEQPACKET, 415 .pr_domain = &localdomain, 416 417 /* 418 * XXXRW: For now, PR_ADDR because soreceive will bump into them 419 * due to our use of sbappendaddr. A new sbappend variants is needed 420 * that supports both atomic record writes and control data. 421 */ 422 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD| 423 PR_RIGHTS, 424 .pr_ctloutput = &uipc_ctloutput, 425 .pr_usrreqs = &uipc_usrreqs_seqpacket, 426 }, 427 }; 428 429 static struct domain localdomain = { 430 .dom_family = AF_LOCAL, 431 .dom_name = "local", 432 .dom_init = unp_init, 433 .dom_externalize = unp_externalize, 434 .dom_dispose = unp_dispose, 435 .dom_protosw = localsw, 436 .dom_protoswNPROTOSW = &localsw[nitems(localsw)] 437 }; 438 DOMAIN_SET(local); 439 440 static void 441 uipc_abort(struct socket *so) 442 { 443 struct unpcb *unp, *unp2; 444 445 unp = sotounpcb(so); 446 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 447 UNP_PCB_UNLOCK_ASSERT(unp); 448 449 UNP_PCB_LOCK(unp); 450 unp2 = unp->unp_conn; 451 if (unp2 != NULL) { 452 unp_pcb_hold(unp2); 453 UNP_PCB_UNLOCK(unp); 454 unp_drop(unp2); 455 } else 456 UNP_PCB_UNLOCK(unp); 457 } 458 459 static int 460 uipc_accept(struct socket *so, struct sockaddr **nam) 461 { 462 struct unpcb *unp, *unp2; 463 const struct sockaddr *sa; 464 465 /* 466 * Pass back name of connected socket, if it was bound and we are 467 * still connected (our peer may have closed already!). 468 */ 469 unp = sotounpcb(so); 470 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 471 472 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 473 UNP_LINK_RLOCK(); 474 unp2 = unp->unp_conn; 475 if (unp2 != NULL && unp2->unp_addr != NULL) { 476 UNP_PCB_LOCK(unp2); 477 sa = (struct sockaddr *) unp2->unp_addr; 478 bcopy(sa, *nam, sa->sa_len); 479 UNP_PCB_UNLOCK(unp2); 480 } else { 481 sa = &sun_noname; 482 bcopy(sa, *nam, sa->sa_len); 483 } 484 UNP_LINK_RUNLOCK(); 485 return (0); 486 } 487 488 static int 489 uipc_attach(struct socket *so, int proto, struct thread *td) 490 { 491 u_long sendspace, recvspace; 492 struct unpcb *unp; 493 int error; 494 bool locked; 495 496 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 497 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 498 switch (so->so_type) { 499 case SOCK_STREAM: 500 sendspace = unpst_sendspace; 501 recvspace = unpst_recvspace; 502 break; 503 504 case SOCK_DGRAM: 505 sendspace = unpdg_sendspace; 506 recvspace = unpdg_recvspace; 507 break; 508 509 case SOCK_SEQPACKET: 510 sendspace = unpsp_sendspace; 511 recvspace = unpsp_recvspace; 512 break; 513 514 default: 515 panic("uipc_attach"); 516 } 517 error = soreserve(so, sendspace, recvspace); 518 if (error) 519 return (error); 520 } 521 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 522 if (unp == NULL) 523 return (ENOBUFS); 524 LIST_INIT(&unp->unp_refs); 525 UNP_PCB_LOCK_INIT(unp); 526 unp->unp_socket = so; 527 so->so_pcb = unp; 528 unp->unp_refcount = 1; 529 530 if ((locked = UNP_LINK_WOWNED()) == false) 531 UNP_LINK_WLOCK(); 532 533 unp->unp_gencnt = ++unp_gencnt; 534 unp->unp_ino = ++unp_ino; 535 unp_count++; 536 switch (so->so_type) { 537 case SOCK_STREAM: 538 LIST_INSERT_HEAD(&unp_shead, unp, unp_link); 539 break; 540 541 case SOCK_DGRAM: 542 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link); 543 break; 544 545 case SOCK_SEQPACKET: 546 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link); 547 break; 548 549 default: 550 panic("uipc_attach"); 551 } 552 553 if (locked == false) 554 UNP_LINK_WUNLOCK(); 555 556 return (0); 557 } 558 559 static int 560 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td) 561 { 562 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 563 struct vattr vattr; 564 int error, namelen; 565 struct nameidata nd; 566 struct unpcb *unp; 567 struct vnode *vp; 568 struct mount *mp; 569 cap_rights_t rights; 570 char *buf; 571 572 if (nam->sa_family != AF_UNIX) 573 return (EAFNOSUPPORT); 574 575 unp = sotounpcb(so); 576 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 577 578 if (soun->sun_len > sizeof(struct sockaddr_un)) 579 return (EINVAL); 580 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 581 if (namelen <= 0) 582 return (EINVAL); 583 584 /* 585 * We don't allow simultaneous bind() calls on a single UNIX domain 586 * socket, so flag in-progress operations, and return an error if an 587 * operation is already in progress. 588 * 589 * Historically, we have not allowed a socket to be rebound, so this 590 * also returns an error. Not allowing re-binding simplifies the 591 * implementation and avoids a great many possible failure modes. 592 */ 593 UNP_PCB_LOCK(unp); 594 if (unp->unp_vnode != NULL) { 595 UNP_PCB_UNLOCK(unp); 596 return (EINVAL); 597 } 598 if (unp->unp_flags & UNP_BINDING) { 599 UNP_PCB_UNLOCK(unp); 600 return (EALREADY); 601 } 602 unp->unp_flags |= UNP_BINDING; 603 UNP_PCB_UNLOCK(unp); 604 605 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 606 bcopy(soun->sun_path, buf, namelen); 607 buf[namelen] = 0; 608 609 restart: 610 NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE, 611 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td); 612 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 613 error = namei(&nd); 614 if (error) 615 goto error; 616 vp = nd.ni_vp; 617 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 618 NDFREE(&nd, NDF_ONLY_PNBUF); 619 if (nd.ni_dvp == vp) 620 vrele(nd.ni_dvp); 621 else 622 vput(nd.ni_dvp); 623 if (vp != NULL) { 624 vrele(vp); 625 error = EADDRINUSE; 626 goto error; 627 } 628 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 629 if (error) 630 goto error; 631 goto restart; 632 } 633 VATTR_NULL(&vattr); 634 vattr.va_type = VSOCK; 635 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 636 #ifdef MAC 637 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 638 &vattr); 639 #endif 640 if (error == 0) 641 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 642 NDFREE(&nd, NDF_ONLY_PNBUF); 643 vput(nd.ni_dvp); 644 if (error) { 645 vn_finished_write(mp); 646 goto error; 647 } 648 vp = nd.ni_vp; 649 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 650 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 651 652 UNP_PCB_LOCK(unp); 653 VOP_UNP_BIND(vp, unp); 654 unp->unp_vnode = vp; 655 unp->unp_addr = soun; 656 unp->unp_flags &= ~UNP_BINDING; 657 UNP_PCB_UNLOCK(unp); 658 VOP_UNLOCK(vp); 659 vn_finished_write(mp); 660 free(buf, M_TEMP); 661 return (0); 662 663 error: 664 UNP_PCB_LOCK(unp); 665 unp->unp_flags &= ~UNP_BINDING; 666 UNP_PCB_UNLOCK(unp); 667 free(buf, M_TEMP); 668 return (error); 669 } 670 671 static int 672 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 673 { 674 675 return (uipc_bindat(AT_FDCWD, so, nam, td)); 676 } 677 678 static int 679 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 680 { 681 int error; 682 683 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 684 error = unp_connect(so, nam, td); 685 return (error); 686 } 687 688 static int 689 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 690 struct thread *td) 691 { 692 int error; 693 694 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 695 error = unp_connectat(fd, so, nam, td); 696 return (error); 697 } 698 699 static void 700 uipc_close(struct socket *so) 701 { 702 struct unpcb *unp, *unp2; 703 struct vnode *vp = NULL; 704 struct mtx *vplock; 705 int freed; 706 unp = sotounpcb(so); 707 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 708 709 vplock = NULL; 710 if ((vp = unp->unp_vnode) != NULL) { 711 vplock = mtx_pool_find(mtxpool_sleep, vp); 712 mtx_lock(vplock); 713 } 714 UNP_PCB_LOCK(unp); 715 if (vp && unp->unp_vnode == NULL) { 716 mtx_unlock(vplock); 717 vp = NULL; 718 } 719 if (vp != NULL) { 720 VOP_UNP_DETACH(vp); 721 unp->unp_vnode = NULL; 722 } 723 unp2 = unp->unp_conn; 724 unp_pcb_hold(unp); 725 if (__predict_false(unp == unp2)) { 726 unp_disconnect(unp, unp2); 727 } else if (unp2 != NULL) { 728 unp_pcb_hold(unp2); 729 unp_pcb_owned_lock2(unp, unp2, freed); 730 unp_disconnect(unp, unp2); 731 if (unp_pcb_rele(unp2) == 0) 732 UNP_PCB_UNLOCK(unp2); 733 } 734 if (unp_pcb_rele(unp) == 0) 735 UNP_PCB_UNLOCK(unp); 736 if (vp) { 737 mtx_unlock(vplock); 738 vrele(vp); 739 } 740 } 741 742 static int 743 uipc_connect2(struct socket *so1, struct socket *so2) 744 { 745 struct unpcb *unp, *unp2; 746 int error; 747 748 unp = so1->so_pcb; 749 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 750 unp2 = so2->so_pcb; 751 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 752 if (unp != unp2) 753 unp_pcb_lock2(unp, unp2); 754 else 755 UNP_PCB_LOCK(unp); 756 error = unp_connect2(so1, so2, PRU_CONNECT2); 757 if (unp != unp2) 758 UNP_PCB_UNLOCK(unp2); 759 UNP_PCB_UNLOCK(unp); 760 return (error); 761 } 762 763 static void 764 uipc_detach(struct socket *so) 765 { 766 struct unpcb *unp, *unp2; 767 struct mtx *vplock; 768 struct vnode *vp; 769 int freeunp, local_unp_rights; 770 771 unp = sotounpcb(so); 772 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 773 774 vp = NULL; 775 vplock = NULL; 776 local_unp_rights = 0; 777 778 SOCK_LOCK(so); 779 if (!SOLISTENING(so)) { 780 /* 781 * Once the socket is removed from the global lists, 782 * uipc_ready() will not be able to locate its socket buffer, so 783 * clear the buffer now. At this point internalized rights have 784 * already been disposed of. 785 */ 786 sbrelease(&so->so_rcv, so); 787 } 788 SOCK_UNLOCK(so); 789 790 UNP_LINK_WLOCK(); 791 LIST_REMOVE(unp, unp_link); 792 if (unp->unp_gcflag & UNPGC_DEAD) 793 LIST_REMOVE(unp, unp_dead); 794 unp->unp_gencnt = ++unp_gencnt; 795 --unp_count; 796 UNP_LINK_WUNLOCK(); 797 798 UNP_PCB_UNLOCK_ASSERT(unp); 799 restart: 800 if ((vp = unp->unp_vnode) != NULL) { 801 vplock = mtx_pool_find(mtxpool_sleep, vp); 802 mtx_lock(vplock); 803 } 804 UNP_PCB_LOCK(unp); 805 if (unp->unp_vnode != vp && unp->unp_vnode != NULL) { 806 if (vplock) 807 mtx_unlock(vplock); 808 UNP_PCB_UNLOCK(unp); 809 goto restart; 810 } 811 if ((vp = unp->unp_vnode) != NULL) { 812 VOP_UNP_DETACH(vp); 813 unp->unp_vnode = NULL; 814 } 815 if (__predict_false(unp == unp->unp_conn)) { 816 unp_disconnect(unp, unp); 817 unp2 = NULL; 818 } else { 819 if ((unp2 = unp->unp_conn) != NULL) { 820 unp_pcb_owned_lock2(unp, unp2, freeunp); 821 if (freeunp) 822 unp2 = NULL; 823 } 824 unp_pcb_hold(unp); 825 if (unp2 != NULL) { 826 unp_pcb_hold(unp2); 827 unp_disconnect(unp, unp2); 828 if (unp_pcb_rele(unp2) == 0) 829 UNP_PCB_UNLOCK(unp2); 830 } 831 } 832 UNP_PCB_UNLOCK(unp); 833 UNP_REF_LIST_LOCK(); 834 while (!LIST_EMPTY(&unp->unp_refs)) { 835 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 836 837 unp_pcb_hold(ref); 838 UNP_REF_LIST_UNLOCK(); 839 840 MPASS(ref != unp); 841 UNP_PCB_UNLOCK_ASSERT(ref); 842 unp_drop(ref); 843 UNP_REF_LIST_LOCK(); 844 } 845 846 UNP_REF_LIST_UNLOCK(); 847 UNP_PCB_LOCK(unp); 848 freeunp = unp_pcb_rele(unp); 849 MPASS(freeunp == 0); 850 local_unp_rights = unp_rights; 851 unp->unp_socket->so_pcb = NULL; 852 unp->unp_socket = NULL; 853 free(unp->unp_addr, M_SONAME); 854 unp->unp_addr = NULL; 855 if (!unp_pcb_rele(unp)) 856 UNP_PCB_UNLOCK(unp); 857 if (vp) { 858 mtx_unlock(vplock); 859 vrele(vp); 860 } 861 if (local_unp_rights) 862 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 863 } 864 865 static int 866 uipc_disconnect(struct socket *so) 867 { 868 struct unpcb *unp, *unp2; 869 int freed; 870 871 unp = sotounpcb(so); 872 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 873 874 UNP_PCB_LOCK(unp); 875 if ((unp2 = unp->unp_conn) == NULL) { 876 UNP_PCB_UNLOCK(unp); 877 return (0); 878 } 879 if (__predict_true(unp != unp2)) { 880 unp_pcb_owned_lock2(unp, unp2, freed); 881 if (__predict_false(freed)) { 882 UNP_PCB_UNLOCK(unp); 883 return (0); 884 } 885 unp_pcb_hold(unp2); 886 } 887 unp_pcb_hold(unp); 888 unp_disconnect(unp, unp2); 889 if (unp_pcb_rele(unp) == 0) 890 UNP_PCB_UNLOCK(unp); 891 if ((unp != unp2) && unp_pcb_rele(unp2) == 0) 892 UNP_PCB_UNLOCK(unp2); 893 return (0); 894 } 895 896 static int 897 uipc_listen(struct socket *so, int backlog, struct thread *td) 898 { 899 struct unpcb *unp; 900 int error; 901 902 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 903 return (EOPNOTSUPP); 904 905 unp = sotounpcb(so); 906 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 907 908 UNP_PCB_LOCK(unp); 909 if (unp->unp_vnode == NULL) { 910 /* Already connected or not bound to an address. */ 911 error = unp->unp_conn != NULL ? EINVAL : EDESTADDRREQ; 912 UNP_PCB_UNLOCK(unp); 913 return (error); 914 } 915 916 SOCK_LOCK(so); 917 error = solisten_proto_check(so); 918 if (error == 0) { 919 cru2xt(td, &unp->unp_peercred); 920 solisten_proto(so, backlog); 921 } 922 SOCK_UNLOCK(so); 923 UNP_PCB_UNLOCK(unp); 924 return (error); 925 } 926 927 static int 928 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 929 { 930 struct unpcb *unp, *unp2; 931 const struct sockaddr *sa; 932 933 unp = sotounpcb(so); 934 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 935 936 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 937 UNP_LINK_RLOCK(); 938 /* 939 * XXX: It seems that this test always fails even when connection is 940 * established. So, this else clause is added as workaround to 941 * return PF_LOCAL sockaddr. 942 */ 943 unp2 = unp->unp_conn; 944 if (unp2 != NULL) { 945 UNP_PCB_LOCK(unp2); 946 if (unp2->unp_addr != NULL) 947 sa = (struct sockaddr *) unp2->unp_addr; 948 else 949 sa = &sun_noname; 950 bcopy(sa, *nam, sa->sa_len); 951 UNP_PCB_UNLOCK(unp2); 952 } else { 953 sa = &sun_noname; 954 bcopy(sa, *nam, sa->sa_len); 955 } 956 UNP_LINK_RUNLOCK(); 957 return (0); 958 } 959 960 static int 961 uipc_rcvd(struct socket *so, int flags) 962 { 963 struct unpcb *unp, *unp2; 964 struct socket *so2; 965 u_int mbcnt, sbcc; 966 967 unp = sotounpcb(so); 968 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 969 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 970 ("%s: socktype %d", __func__, so->so_type)); 971 972 /* 973 * Adjust backpressure on sender and wakeup any waiting to write. 974 * 975 * The unp lock is acquired to maintain the validity of the unp_conn 976 * pointer; no lock on unp2 is required as unp2->unp_socket will be 977 * static as long as we don't permit unp2 to disconnect from unp, 978 * which is prevented by the lock on unp. We cache values from 979 * so_rcv to avoid holding the so_rcv lock over the entire 980 * transaction on the remote so_snd. 981 */ 982 SOCKBUF_LOCK(&so->so_rcv); 983 mbcnt = so->so_rcv.sb_mbcnt; 984 sbcc = sbavail(&so->so_rcv); 985 SOCKBUF_UNLOCK(&so->so_rcv); 986 /* 987 * There is a benign race condition at this point. If we're planning to 988 * clear SB_STOP, but uipc_send is called on the connected socket at 989 * this instant, it might add data to the sockbuf and set SB_STOP. Then 990 * we would erroneously clear SB_STOP below, even though the sockbuf is 991 * full. The race is benign because the only ill effect is to allow the 992 * sockbuf to exceed its size limit, and the size limits are not 993 * strictly guaranteed anyway. 994 */ 995 UNP_PCB_LOCK(unp); 996 unp2 = unp->unp_conn; 997 if (unp2 == NULL) { 998 UNP_PCB_UNLOCK(unp); 999 return (0); 1000 } 1001 so2 = unp2->unp_socket; 1002 SOCKBUF_LOCK(&so2->so_snd); 1003 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 1004 so2->so_snd.sb_flags &= ~SB_STOP; 1005 sowwakeup_locked(so2); 1006 UNP_PCB_UNLOCK(unp); 1007 return (0); 1008 } 1009 1010 static int 1011 connect_internal(struct socket *so, struct sockaddr *nam, struct thread *td) 1012 { 1013 int error; 1014 struct unpcb *unp; 1015 1016 unp = so->so_pcb; 1017 if (unp->unp_conn != NULL) 1018 return (EISCONN); 1019 error = unp_connect(so, nam, td); 1020 if (error) 1021 return (error); 1022 UNP_PCB_LOCK(unp); 1023 if (unp->unp_conn == NULL) { 1024 UNP_PCB_UNLOCK(unp); 1025 if (error == 0) 1026 error = ENOTCONN; 1027 } 1028 return (error); 1029 } 1030 1031 static int 1032 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 1033 struct mbuf *control, struct thread *td) 1034 { 1035 struct unpcb *unp, *unp2; 1036 struct socket *so2; 1037 u_int mbcnt, sbcc; 1038 int freed, error; 1039 1040 unp = sotounpcb(so); 1041 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 1042 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 1043 so->so_type == SOCK_SEQPACKET, 1044 ("%s: socktype %d", __func__, so->so_type)); 1045 1046 freed = error = 0; 1047 if (flags & PRUS_OOB) { 1048 error = EOPNOTSUPP; 1049 goto release; 1050 } 1051 if (control != NULL && (error = unp_internalize(&control, td))) 1052 goto release; 1053 1054 unp2 = NULL; 1055 switch (so->so_type) { 1056 case SOCK_DGRAM: 1057 { 1058 const struct sockaddr *from; 1059 1060 if (nam != NULL) { 1061 /* 1062 * We return with UNP_PCB_LOCK_HELD so we know that 1063 * the reference is live if the pointer is valid. 1064 */ 1065 if ((error = connect_internal(so, nam, td))) 1066 break; 1067 MPASS(unp->unp_conn != NULL); 1068 unp2 = unp->unp_conn; 1069 } else { 1070 UNP_PCB_LOCK(unp); 1071 1072 /* 1073 * Because connect() and send() are non-atomic in a sendto() 1074 * with a target address, it's possible that the socket will 1075 * have disconnected before the send() can run. In that case 1076 * return the slightly counter-intuitive but otherwise 1077 * correct error that the socket is not connected. 1078 */ 1079 if ((unp2 = unp->unp_conn) == NULL) { 1080 UNP_PCB_UNLOCK(unp); 1081 error = ENOTCONN; 1082 break; 1083 } 1084 } 1085 if (__predict_false(unp == unp2)) { 1086 if (unp->unp_socket == NULL) { 1087 error = ENOTCONN; 1088 break; 1089 } 1090 goto connect_self; 1091 } 1092 unp_pcb_owned_lock2(unp, unp2, freed); 1093 if (__predict_false(freed)) { 1094 UNP_PCB_UNLOCK(unp); 1095 error = ENOTCONN; 1096 break; 1097 } 1098 /* 1099 * The socket referencing unp2 may have been closed 1100 * or unp may have been disconnected if the unp lock 1101 * was dropped to acquire unp2. 1102 */ 1103 if (__predict_false(unp->unp_conn == NULL) || 1104 unp2->unp_socket == NULL) { 1105 UNP_PCB_UNLOCK(unp); 1106 if (unp_pcb_rele(unp2) == 0) 1107 UNP_PCB_UNLOCK(unp2); 1108 error = ENOTCONN; 1109 break; 1110 } 1111 connect_self: 1112 if (unp2->unp_flags & UNP_WANTCRED) 1113 control = unp_addsockcred(td, control); 1114 if (unp->unp_addr != NULL) 1115 from = (struct sockaddr *)unp->unp_addr; 1116 else 1117 from = &sun_noname; 1118 so2 = unp2->unp_socket; 1119 SOCKBUF_LOCK(&so2->so_rcv); 1120 if (sbappendaddr_locked(&so2->so_rcv, from, m, 1121 control)) { 1122 sorwakeup_locked(so2); 1123 m = NULL; 1124 control = NULL; 1125 } else { 1126 SOCKBUF_UNLOCK(&so2->so_rcv); 1127 error = ENOBUFS; 1128 } 1129 if (nam != NULL) 1130 unp_disconnect(unp, unp2); 1131 if (__predict_true(unp != unp2)) 1132 UNP_PCB_UNLOCK(unp2); 1133 UNP_PCB_UNLOCK(unp); 1134 break; 1135 } 1136 1137 case SOCK_SEQPACKET: 1138 case SOCK_STREAM: 1139 if ((so->so_state & SS_ISCONNECTED) == 0) { 1140 if (nam != NULL) { 1141 error = connect_internal(so, nam, td); 1142 if (error != 0) 1143 break; 1144 } else { 1145 error = ENOTCONN; 1146 break; 1147 } 1148 } else { 1149 UNP_PCB_LOCK(unp); 1150 } 1151 1152 if ((unp2 = unp->unp_conn) == NULL) { 1153 UNP_PCB_UNLOCK(unp); 1154 error = ENOTCONN; 1155 break; 1156 } else if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 1157 UNP_PCB_UNLOCK(unp); 1158 error = EPIPE; 1159 break; 1160 } else if ((unp2 = unp->unp_conn) == NULL) { 1161 UNP_PCB_UNLOCK(unp); 1162 error = ENOTCONN; 1163 break; 1164 } 1165 unp_pcb_owned_lock2(unp, unp2, freed); 1166 UNP_PCB_UNLOCK(unp); 1167 if (__predict_false(freed)) { 1168 error = ENOTCONN; 1169 break; 1170 } 1171 if ((so2 = unp2->unp_socket) == NULL) { 1172 UNP_PCB_UNLOCK(unp2); 1173 error = ENOTCONN; 1174 break; 1175 } 1176 SOCKBUF_LOCK(&so2->so_rcv); 1177 if (unp2->unp_flags & UNP_WANTCRED) { 1178 /* 1179 * Credentials are passed only once on SOCK_STREAM 1180 * and SOCK_SEQPACKET. 1181 */ 1182 unp2->unp_flags &= ~UNP_WANTCRED; 1183 control = unp_addsockcred(td, control); 1184 } 1185 1186 /* 1187 * Send to paired receive port and wake up readers. Don't 1188 * check for space available in the receive buffer if we're 1189 * attaching ancillary data; Unix domain sockets only check 1190 * for space in the sending sockbuf, and that check is 1191 * performed one level up the stack. At that level we cannot 1192 * precisely account for the amount of buffer space used 1193 * (e.g., because control messages are not yet internalized). 1194 */ 1195 switch (so->so_type) { 1196 case SOCK_STREAM: 1197 if (control != NULL) { 1198 sbappendcontrol_locked(&so2->so_rcv, m, 1199 control, flags); 1200 control = NULL; 1201 } else 1202 sbappend_locked(&so2->so_rcv, m, flags); 1203 break; 1204 1205 case SOCK_SEQPACKET: 1206 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 1207 &sun_noname, m, control)) 1208 control = NULL; 1209 break; 1210 } 1211 1212 mbcnt = so2->so_rcv.sb_mbcnt; 1213 sbcc = sbavail(&so2->so_rcv); 1214 if (sbcc) 1215 sorwakeup_locked(so2); 1216 else 1217 SOCKBUF_UNLOCK(&so2->so_rcv); 1218 1219 /* 1220 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1221 * it would be possible for uipc_rcvd to be called at this 1222 * point, drain the receiving sockbuf, clear SB_STOP, and then 1223 * we would set SB_STOP below. That could lead to an empty 1224 * sockbuf having SB_STOP set 1225 */ 1226 SOCKBUF_LOCK(&so->so_snd); 1227 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1228 so->so_snd.sb_flags |= SB_STOP; 1229 SOCKBUF_UNLOCK(&so->so_snd); 1230 UNP_PCB_UNLOCK(unp2); 1231 m = NULL; 1232 break; 1233 } 1234 1235 /* 1236 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1237 */ 1238 if (flags & PRUS_EOF) { 1239 UNP_PCB_LOCK(unp); 1240 socantsendmore(so); 1241 unp_shutdown(unp); 1242 UNP_PCB_UNLOCK(unp); 1243 } 1244 if (control != NULL && error != 0) 1245 unp_dispose_mbuf(control); 1246 1247 release: 1248 if (control != NULL) 1249 m_freem(control); 1250 /* 1251 * In case of PRUS_NOTREADY, uipc_ready() is responsible 1252 * for freeing memory. 1253 */ 1254 if (m != NULL && (flags & PRUS_NOTREADY) == 0) 1255 m_freem(m); 1256 return (error); 1257 } 1258 1259 static bool 1260 uipc_ready_scan(struct socket *so, struct mbuf *m, int count, int *errorp) 1261 { 1262 struct mbuf *mb, *n; 1263 struct sockbuf *sb; 1264 1265 SOCK_LOCK(so); 1266 if (SOLISTENING(so)) { 1267 SOCK_UNLOCK(so); 1268 return (false); 1269 } 1270 mb = NULL; 1271 sb = &so->so_rcv; 1272 SOCKBUF_LOCK(sb); 1273 if (sb->sb_fnrdy != NULL) { 1274 for (mb = sb->sb_mb, n = mb->m_nextpkt; mb != NULL;) { 1275 if (mb == m) { 1276 *errorp = sbready(sb, m, count); 1277 break; 1278 } 1279 mb = mb->m_next; 1280 if (mb == NULL) { 1281 mb = n; 1282 n = mb->m_nextpkt; 1283 } 1284 } 1285 } 1286 SOCKBUF_UNLOCK(sb); 1287 SOCK_UNLOCK(so); 1288 return (mb != NULL); 1289 } 1290 1291 static int 1292 uipc_ready(struct socket *so, struct mbuf *m, int count) 1293 { 1294 struct unpcb *unp, *unp2; 1295 struct socket *so2; 1296 int error, i; 1297 1298 unp = sotounpcb(so); 1299 1300 KASSERT(so->so_type == SOCK_STREAM, 1301 ("%s: unexpected socket type for %p", __func__, so)); 1302 1303 UNP_PCB_LOCK(unp); 1304 if ((unp2 = unp->unp_conn) == NULL) { 1305 UNP_PCB_UNLOCK(unp); 1306 goto search; 1307 } 1308 if (unp != unp2) { 1309 if (UNP_PCB_TRYLOCK(unp2) == 0) { 1310 unp_pcb_hold(unp2); 1311 UNP_PCB_UNLOCK(unp); 1312 UNP_PCB_LOCK(unp2); 1313 if (unp_pcb_rele(unp2)) 1314 goto search; 1315 } else 1316 UNP_PCB_UNLOCK(unp); 1317 } 1318 so2 = unp2->unp_socket; 1319 SOCKBUF_LOCK(&so2->so_rcv); 1320 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1321 sorwakeup_locked(so2); 1322 else 1323 SOCKBUF_UNLOCK(&so2->so_rcv); 1324 UNP_PCB_UNLOCK(unp2); 1325 return (error); 1326 1327 search: 1328 /* 1329 * The receiving socket has been disconnected, but may still be valid. 1330 * In this case, the now-ready mbufs are still present in its socket 1331 * buffer, so perform an exhaustive search before giving up and freeing 1332 * the mbufs. 1333 */ 1334 UNP_LINK_RLOCK(); 1335 LIST_FOREACH(unp, &unp_shead, unp_link) { 1336 if (uipc_ready_scan(unp->unp_socket, m, count, &error)) 1337 break; 1338 } 1339 UNP_LINK_RUNLOCK(); 1340 1341 if (unp == NULL) { 1342 for (i = 0; i < count; i++) 1343 m = m_free(m); 1344 error = ECONNRESET; 1345 } 1346 return (error); 1347 } 1348 1349 static int 1350 uipc_sense(struct socket *so, struct stat *sb) 1351 { 1352 struct unpcb *unp; 1353 1354 unp = sotounpcb(so); 1355 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1356 1357 sb->st_blksize = so->so_snd.sb_hiwat; 1358 sb->st_dev = NODEV; 1359 sb->st_ino = unp->unp_ino; 1360 return (0); 1361 } 1362 1363 static int 1364 uipc_shutdown(struct socket *so) 1365 { 1366 struct unpcb *unp; 1367 1368 unp = sotounpcb(so); 1369 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1370 1371 UNP_PCB_LOCK(unp); 1372 socantsendmore(so); 1373 unp_shutdown(unp); 1374 UNP_PCB_UNLOCK(unp); 1375 return (0); 1376 } 1377 1378 static int 1379 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1380 { 1381 struct unpcb *unp; 1382 const struct sockaddr *sa; 1383 1384 unp = sotounpcb(so); 1385 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1386 1387 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1388 UNP_PCB_LOCK(unp); 1389 if (unp->unp_addr != NULL) 1390 sa = (struct sockaddr *) unp->unp_addr; 1391 else 1392 sa = &sun_noname; 1393 bcopy(sa, *nam, sa->sa_len); 1394 UNP_PCB_UNLOCK(unp); 1395 return (0); 1396 } 1397 1398 static struct pr_usrreqs uipc_usrreqs_dgram = { 1399 .pru_abort = uipc_abort, 1400 .pru_accept = uipc_accept, 1401 .pru_attach = uipc_attach, 1402 .pru_bind = uipc_bind, 1403 .pru_bindat = uipc_bindat, 1404 .pru_connect = uipc_connect, 1405 .pru_connectat = uipc_connectat, 1406 .pru_connect2 = uipc_connect2, 1407 .pru_detach = uipc_detach, 1408 .pru_disconnect = uipc_disconnect, 1409 .pru_listen = uipc_listen, 1410 .pru_peeraddr = uipc_peeraddr, 1411 .pru_rcvd = uipc_rcvd, 1412 .pru_send = uipc_send, 1413 .pru_sense = uipc_sense, 1414 .pru_shutdown = uipc_shutdown, 1415 .pru_sockaddr = uipc_sockaddr, 1416 .pru_soreceive = soreceive_dgram, 1417 .pru_close = uipc_close, 1418 }; 1419 1420 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1421 .pru_abort = uipc_abort, 1422 .pru_accept = uipc_accept, 1423 .pru_attach = uipc_attach, 1424 .pru_bind = uipc_bind, 1425 .pru_bindat = uipc_bindat, 1426 .pru_connect = uipc_connect, 1427 .pru_connectat = uipc_connectat, 1428 .pru_connect2 = uipc_connect2, 1429 .pru_detach = uipc_detach, 1430 .pru_disconnect = uipc_disconnect, 1431 .pru_listen = uipc_listen, 1432 .pru_peeraddr = uipc_peeraddr, 1433 .pru_rcvd = uipc_rcvd, 1434 .pru_send = uipc_send, 1435 .pru_sense = uipc_sense, 1436 .pru_shutdown = uipc_shutdown, 1437 .pru_sockaddr = uipc_sockaddr, 1438 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1439 .pru_close = uipc_close, 1440 }; 1441 1442 static struct pr_usrreqs uipc_usrreqs_stream = { 1443 .pru_abort = uipc_abort, 1444 .pru_accept = uipc_accept, 1445 .pru_attach = uipc_attach, 1446 .pru_bind = uipc_bind, 1447 .pru_bindat = uipc_bindat, 1448 .pru_connect = uipc_connect, 1449 .pru_connectat = uipc_connectat, 1450 .pru_connect2 = uipc_connect2, 1451 .pru_detach = uipc_detach, 1452 .pru_disconnect = uipc_disconnect, 1453 .pru_listen = uipc_listen, 1454 .pru_peeraddr = uipc_peeraddr, 1455 .pru_rcvd = uipc_rcvd, 1456 .pru_send = uipc_send, 1457 .pru_ready = uipc_ready, 1458 .pru_sense = uipc_sense, 1459 .pru_shutdown = uipc_shutdown, 1460 .pru_sockaddr = uipc_sockaddr, 1461 .pru_soreceive = soreceive_generic, 1462 .pru_close = uipc_close, 1463 }; 1464 1465 static int 1466 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1467 { 1468 struct unpcb *unp; 1469 struct xucred xu; 1470 int error, optval; 1471 1472 if (sopt->sopt_level != 0) 1473 return (EINVAL); 1474 1475 unp = sotounpcb(so); 1476 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1477 error = 0; 1478 switch (sopt->sopt_dir) { 1479 case SOPT_GET: 1480 switch (sopt->sopt_name) { 1481 case LOCAL_PEERCRED: 1482 UNP_PCB_LOCK(unp); 1483 if (unp->unp_flags & UNP_HAVEPC) 1484 xu = unp->unp_peercred; 1485 else { 1486 if (so->so_type == SOCK_STREAM) 1487 error = ENOTCONN; 1488 else 1489 error = EINVAL; 1490 } 1491 UNP_PCB_UNLOCK(unp); 1492 if (error == 0) 1493 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1494 break; 1495 1496 case LOCAL_CREDS: 1497 /* Unlocked read. */ 1498 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1499 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1500 break; 1501 1502 case LOCAL_CONNWAIT: 1503 /* Unlocked read. */ 1504 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1505 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1506 break; 1507 1508 default: 1509 error = EOPNOTSUPP; 1510 break; 1511 } 1512 break; 1513 1514 case SOPT_SET: 1515 switch (sopt->sopt_name) { 1516 case LOCAL_CREDS: 1517 case LOCAL_CONNWAIT: 1518 error = sooptcopyin(sopt, &optval, sizeof(optval), 1519 sizeof(optval)); 1520 if (error) 1521 break; 1522 1523 #define OPTSET(bit) do { \ 1524 UNP_PCB_LOCK(unp); \ 1525 if (optval) \ 1526 unp->unp_flags |= bit; \ 1527 else \ 1528 unp->unp_flags &= ~bit; \ 1529 UNP_PCB_UNLOCK(unp); \ 1530 } while (0) 1531 1532 switch (sopt->sopt_name) { 1533 case LOCAL_CREDS: 1534 OPTSET(UNP_WANTCRED); 1535 break; 1536 1537 case LOCAL_CONNWAIT: 1538 OPTSET(UNP_CONNWAIT); 1539 break; 1540 1541 default: 1542 break; 1543 } 1544 break; 1545 #undef OPTSET 1546 default: 1547 error = ENOPROTOOPT; 1548 break; 1549 } 1550 break; 1551 1552 default: 1553 error = EOPNOTSUPP; 1554 break; 1555 } 1556 return (error); 1557 } 1558 1559 static int 1560 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1561 { 1562 1563 return (unp_connectat(AT_FDCWD, so, nam, td)); 1564 } 1565 1566 static int 1567 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1568 struct thread *td) 1569 { 1570 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1571 struct vnode *vp; 1572 struct socket *so2; 1573 struct unpcb *unp, *unp2, *unp3; 1574 struct nameidata nd; 1575 char buf[SOCK_MAXADDRLEN]; 1576 struct sockaddr *sa; 1577 cap_rights_t rights; 1578 int error, len, freed; 1579 struct mtx *vplock; 1580 1581 if (nam->sa_family != AF_UNIX) 1582 return (EAFNOSUPPORT); 1583 if (nam->sa_len > sizeof(struct sockaddr_un)) 1584 return (EINVAL); 1585 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1586 if (len <= 0) 1587 return (EINVAL); 1588 bcopy(soun->sun_path, buf, len); 1589 buf[len] = 0; 1590 1591 unp = sotounpcb(so); 1592 UNP_PCB_LOCK(unp); 1593 if (unp->unp_flags & UNP_CONNECTING) { 1594 UNP_PCB_UNLOCK(unp); 1595 return (EALREADY); 1596 } 1597 unp->unp_flags |= UNP_CONNECTING; 1598 UNP_PCB_UNLOCK(unp); 1599 1600 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1601 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1602 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td); 1603 error = namei(&nd); 1604 if (error) 1605 vp = NULL; 1606 else 1607 vp = nd.ni_vp; 1608 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1609 NDFREE(&nd, NDF_ONLY_PNBUF); 1610 if (error) 1611 goto bad; 1612 1613 if (vp->v_type != VSOCK) { 1614 error = ENOTSOCK; 1615 goto bad; 1616 } 1617 #ifdef MAC 1618 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1619 if (error) 1620 goto bad; 1621 #endif 1622 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1623 if (error) 1624 goto bad; 1625 1626 unp = sotounpcb(so); 1627 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1628 1629 vplock = mtx_pool_find(mtxpool_sleep, vp); 1630 mtx_lock(vplock); 1631 VOP_UNP_CONNECT(vp, &unp2); 1632 if (unp2 == NULL) { 1633 error = ECONNREFUSED; 1634 goto bad2; 1635 } 1636 so2 = unp2->unp_socket; 1637 if (so->so_type != so2->so_type) { 1638 error = EPROTOTYPE; 1639 goto bad2; 1640 } 1641 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1642 if (so2->so_options & SO_ACCEPTCONN) { 1643 CURVNET_SET(so2->so_vnet); 1644 so2 = sonewconn(so2, 0); 1645 CURVNET_RESTORE(); 1646 } else 1647 so2 = NULL; 1648 if (so2 == NULL) { 1649 error = ECONNREFUSED; 1650 goto bad2; 1651 } 1652 unp3 = sotounpcb(so2); 1653 unp_pcb_lock2(unp2, unp3); 1654 if (unp2->unp_addr != NULL) { 1655 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1656 unp3->unp_addr = (struct sockaddr_un *) sa; 1657 sa = NULL; 1658 } 1659 1660 unp_copy_peercred(td, unp3, unp, unp2); 1661 1662 UNP_PCB_UNLOCK(unp2); 1663 unp2 = unp3; 1664 unp_pcb_owned_lock2(unp2, unp, freed); 1665 if (__predict_false(freed)) { 1666 UNP_PCB_UNLOCK(unp2); 1667 error = ECONNREFUSED; 1668 goto bad2; 1669 } 1670 #ifdef MAC 1671 mac_socketpeer_set_from_socket(so, so2); 1672 mac_socketpeer_set_from_socket(so2, so); 1673 #endif 1674 } else { 1675 if (unp == unp2) 1676 UNP_PCB_LOCK(unp); 1677 else 1678 unp_pcb_lock2(unp, unp2); 1679 } 1680 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1681 sotounpcb(so2) == unp2, 1682 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1683 error = unp_connect2(so, so2, PRU_CONNECT); 1684 if (unp != unp2) 1685 UNP_PCB_UNLOCK(unp2); 1686 UNP_PCB_UNLOCK(unp); 1687 bad2: 1688 mtx_unlock(vplock); 1689 bad: 1690 if (vp != NULL) { 1691 vput(vp); 1692 } 1693 free(sa, M_SONAME); 1694 UNP_PCB_LOCK(unp); 1695 unp->unp_flags &= ~UNP_CONNECTING; 1696 UNP_PCB_UNLOCK(unp); 1697 return (error); 1698 } 1699 1700 /* 1701 * Set socket peer credentials at connection time. 1702 * 1703 * The client's PCB credentials are copied from its process structure. The 1704 * server's PCB credentials are copied from the socket on which it called 1705 * listen(2). uipc_listen cached that process's credentials at the time. 1706 */ 1707 void 1708 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 1709 struct unpcb *server_unp, struct unpcb *listen_unp) 1710 { 1711 cru2xt(td, &client_unp->unp_peercred); 1712 client_unp->unp_flags |= UNP_HAVEPC; 1713 1714 memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred, 1715 sizeof(server_unp->unp_peercred)); 1716 server_unp->unp_flags |= UNP_HAVEPC; 1717 if (listen_unp->unp_flags & UNP_WANTCRED) 1718 client_unp->unp_flags |= UNP_WANTCRED; 1719 } 1720 1721 static int 1722 unp_connect2(struct socket *so, struct socket *so2, int req) 1723 { 1724 struct unpcb *unp; 1725 struct unpcb *unp2; 1726 1727 unp = sotounpcb(so); 1728 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1729 unp2 = sotounpcb(so2); 1730 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1731 1732 UNP_PCB_LOCK_ASSERT(unp); 1733 UNP_PCB_LOCK_ASSERT(unp2); 1734 1735 if (so2->so_type != so->so_type) 1736 return (EPROTOTYPE); 1737 unp->unp_conn = unp2; 1738 unp_pcb_hold(unp2); 1739 unp_pcb_hold(unp); 1740 switch (so->so_type) { 1741 case SOCK_DGRAM: 1742 UNP_REF_LIST_LOCK(); 1743 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1744 UNP_REF_LIST_UNLOCK(); 1745 soisconnected(so); 1746 break; 1747 1748 case SOCK_STREAM: 1749 case SOCK_SEQPACKET: 1750 unp2->unp_conn = unp; 1751 if (req == PRU_CONNECT && 1752 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1753 soisconnecting(so); 1754 else 1755 soisconnected(so); 1756 soisconnected(so2); 1757 break; 1758 1759 default: 1760 panic("unp_connect2"); 1761 } 1762 return (0); 1763 } 1764 1765 static void 1766 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1767 { 1768 struct socket *so, *so2; 1769 int freed __unused; 1770 1771 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1772 1773 UNP_PCB_LOCK_ASSERT(unp); 1774 UNP_PCB_LOCK_ASSERT(unp2); 1775 1776 if (unp->unp_conn == NULL && unp2->unp_conn == NULL) 1777 return; 1778 1779 MPASS(unp->unp_conn == unp2); 1780 unp->unp_conn = NULL; 1781 so = unp->unp_socket; 1782 so2 = unp2->unp_socket; 1783 switch (unp->unp_socket->so_type) { 1784 case SOCK_DGRAM: 1785 UNP_REF_LIST_LOCK(); 1786 LIST_REMOVE(unp, unp_reflink); 1787 UNP_REF_LIST_UNLOCK(); 1788 if (so) { 1789 SOCK_LOCK(so); 1790 so->so_state &= ~SS_ISCONNECTED; 1791 SOCK_UNLOCK(so); 1792 } 1793 break; 1794 1795 case SOCK_STREAM: 1796 case SOCK_SEQPACKET: 1797 if (so) 1798 soisdisconnected(so); 1799 MPASS(unp2->unp_conn == unp); 1800 unp2->unp_conn = NULL; 1801 if (so2) 1802 soisdisconnected(so2); 1803 break; 1804 } 1805 freed = unp_pcb_rele(unp); 1806 MPASS(freed == 0); 1807 freed = unp_pcb_rele(unp2); 1808 MPASS(freed == 0); 1809 } 1810 1811 /* 1812 * unp_pcblist() walks the global list of struct unpcb's to generate a 1813 * pointer list, bumping the refcount on each unpcb. It then copies them out 1814 * sequentially, validating the generation number on each to see if it has 1815 * been detached. All of this is necessary because copyout() may sleep on 1816 * disk I/O. 1817 */ 1818 static int 1819 unp_pcblist(SYSCTL_HANDLER_ARGS) 1820 { 1821 struct unpcb *unp, **unp_list; 1822 unp_gen_t gencnt; 1823 struct xunpgen *xug; 1824 struct unp_head *head; 1825 struct xunpcb *xu; 1826 u_int i; 1827 int error, freeunp, n; 1828 1829 switch ((intptr_t)arg1) { 1830 case SOCK_STREAM: 1831 head = &unp_shead; 1832 break; 1833 1834 case SOCK_DGRAM: 1835 head = &unp_dhead; 1836 break; 1837 1838 case SOCK_SEQPACKET: 1839 head = &unp_sphead; 1840 break; 1841 1842 default: 1843 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1844 } 1845 1846 /* 1847 * The process of preparing the PCB list is too time-consuming and 1848 * resource-intensive to repeat twice on every request. 1849 */ 1850 if (req->oldptr == NULL) { 1851 n = unp_count; 1852 req->oldidx = 2 * (sizeof *xug) 1853 + (n + n/8) * sizeof(struct xunpcb); 1854 return (0); 1855 } 1856 1857 if (req->newptr != NULL) 1858 return (EPERM); 1859 1860 /* 1861 * OK, now we're committed to doing something. 1862 */ 1863 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK | M_ZERO); 1864 UNP_LINK_RLOCK(); 1865 gencnt = unp_gencnt; 1866 n = unp_count; 1867 UNP_LINK_RUNLOCK(); 1868 1869 xug->xug_len = sizeof *xug; 1870 xug->xug_count = n; 1871 xug->xug_gen = gencnt; 1872 xug->xug_sogen = so_gencnt; 1873 error = SYSCTL_OUT(req, xug, sizeof *xug); 1874 if (error) { 1875 free(xug, M_TEMP); 1876 return (error); 1877 } 1878 1879 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1880 1881 UNP_LINK_RLOCK(); 1882 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1883 unp = LIST_NEXT(unp, unp_link)) { 1884 UNP_PCB_LOCK(unp); 1885 if (unp->unp_gencnt <= gencnt) { 1886 if (cr_cansee(req->td->td_ucred, 1887 unp->unp_socket->so_cred)) { 1888 UNP_PCB_UNLOCK(unp); 1889 continue; 1890 } 1891 unp_list[i++] = unp; 1892 unp_pcb_hold(unp); 1893 } 1894 UNP_PCB_UNLOCK(unp); 1895 } 1896 UNP_LINK_RUNLOCK(); 1897 n = i; /* In case we lost some during malloc. */ 1898 1899 error = 0; 1900 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1901 for (i = 0; i < n; i++) { 1902 unp = unp_list[i]; 1903 UNP_PCB_LOCK(unp); 1904 freeunp = unp_pcb_rele(unp); 1905 1906 if (freeunp == 0 && unp->unp_gencnt <= gencnt) { 1907 xu->xu_len = sizeof *xu; 1908 xu->xu_unpp = (uintptr_t)unp; 1909 /* 1910 * XXX - need more locking here to protect against 1911 * connect/disconnect races for SMP. 1912 */ 1913 if (unp->unp_addr != NULL) 1914 bcopy(unp->unp_addr, &xu->xu_addr, 1915 unp->unp_addr->sun_len); 1916 else 1917 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1918 if (unp->unp_conn != NULL && 1919 unp->unp_conn->unp_addr != NULL) 1920 bcopy(unp->unp_conn->unp_addr, 1921 &xu->xu_caddr, 1922 unp->unp_conn->unp_addr->sun_len); 1923 else 1924 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1925 xu->unp_vnode = (uintptr_t)unp->unp_vnode; 1926 xu->unp_conn = (uintptr_t)unp->unp_conn; 1927 xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs); 1928 xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink); 1929 xu->unp_gencnt = unp->unp_gencnt; 1930 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1931 UNP_PCB_UNLOCK(unp); 1932 error = SYSCTL_OUT(req, xu, sizeof *xu); 1933 } else if (freeunp == 0) 1934 UNP_PCB_UNLOCK(unp); 1935 } 1936 free(xu, M_TEMP); 1937 if (!error) { 1938 /* 1939 * Give the user an updated idea of our state. If the 1940 * generation differs from what we told her before, she knows 1941 * that something happened while we were processing this 1942 * request, and it might be necessary to retry. 1943 */ 1944 xug->xug_gen = unp_gencnt; 1945 xug->xug_sogen = so_gencnt; 1946 xug->xug_count = unp_count; 1947 error = SYSCTL_OUT(req, xug, sizeof *xug); 1948 } 1949 free(unp_list, M_TEMP); 1950 free(xug, M_TEMP); 1951 return (error); 1952 } 1953 1954 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, 1955 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1956 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1957 "List of active local datagram sockets"); 1958 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, 1959 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1960 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1961 "List of active local stream sockets"); 1962 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1963 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1964 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1965 "List of active local seqpacket sockets"); 1966 1967 static void 1968 unp_shutdown(struct unpcb *unp) 1969 { 1970 struct unpcb *unp2; 1971 struct socket *so; 1972 1973 UNP_PCB_LOCK_ASSERT(unp); 1974 1975 unp2 = unp->unp_conn; 1976 if ((unp->unp_socket->so_type == SOCK_STREAM || 1977 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1978 so = unp2->unp_socket; 1979 if (so != NULL) 1980 socantrcvmore(so); 1981 } 1982 } 1983 1984 static void 1985 unp_drop(struct unpcb *unp) 1986 { 1987 struct socket *so = unp->unp_socket; 1988 struct unpcb *unp2; 1989 int freed; 1990 1991 /* 1992 * Regardless of whether the socket's peer dropped the connection 1993 * with this socket by aborting or disconnecting, POSIX requires 1994 * that ECONNRESET is returned. 1995 */ 1996 /* acquire a reference so that unp isn't freed from underneath us */ 1997 1998 UNP_PCB_LOCK(unp); 1999 if (so) 2000 so->so_error = ECONNRESET; 2001 unp2 = unp->unp_conn; 2002 if (unp2 == unp) { 2003 unp_disconnect(unp, unp2); 2004 } else if (unp2 != NULL) { 2005 unp_pcb_hold(unp2); 2006 unp_pcb_owned_lock2(unp, unp2, freed); 2007 unp_disconnect(unp, unp2); 2008 if (unp_pcb_rele(unp2) == 0) 2009 UNP_PCB_UNLOCK(unp2); 2010 } 2011 if (unp_pcb_rele(unp) == 0) 2012 UNP_PCB_UNLOCK(unp); 2013 } 2014 2015 static void 2016 unp_freerights(struct filedescent **fdep, int fdcount) 2017 { 2018 struct file *fp; 2019 int i; 2020 2021 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 2022 2023 for (i = 0; i < fdcount; i++) { 2024 fp = fdep[i]->fde_file; 2025 filecaps_free(&fdep[i]->fde_caps); 2026 unp_discard(fp); 2027 } 2028 free(fdep[0], M_FILECAPS); 2029 } 2030 2031 static int 2032 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 2033 { 2034 struct thread *td = curthread; /* XXX */ 2035 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2036 int i; 2037 int *fdp; 2038 struct filedesc *fdesc = td->td_proc->p_fd; 2039 struct filedescent **fdep; 2040 void *data; 2041 socklen_t clen = control->m_len, datalen; 2042 int error, newfds; 2043 u_int newlen; 2044 2045 UNP_LINK_UNLOCK_ASSERT(); 2046 2047 error = 0; 2048 if (controlp != NULL) /* controlp == NULL => free control messages */ 2049 *controlp = NULL; 2050 while (cm != NULL) { 2051 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 2052 error = EINVAL; 2053 break; 2054 } 2055 data = CMSG_DATA(cm); 2056 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2057 if (cm->cmsg_level == SOL_SOCKET 2058 && cm->cmsg_type == SCM_RIGHTS) { 2059 newfds = datalen / sizeof(*fdep); 2060 if (newfds == 0) 2061 goto next; 2062 fdep = data; 2063 2064 /* If we're not outputting the descriptors free them. */ 2065 if (error || controlp == NULL) { 2066 unp_freerights(fdep, newfds); 2067 goto next; 2068 } 2069 FILEDESC_XLOCK(fdesc); 2070 2071 /* 2072 * Now change each pointer to an fd in the global 2073 * table to an integer that is the index to the local 2074 * fd table entry that we set up to point to the 2075 * global one we are transferring. 2076 */ 2077 newlen = newfds * sizeof(int); 2078 *controlp = sbcreatecontrol(NULL, newlen, 2079 SCM_RIGHTS, SOL_SOCKET); 2080 if (*controlp == NULL) { 2081 FILEDESC_XUNLOCK(fdesc); 2082 error = E2BIG; 2083 unp_freerights(fdep, newfds); 2084 goto next; 2085 } 2086 2087 fdp = (int *) 2088 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2089 if (fdallocn(td, 0, fdp, newfds) != 0) { 2090 FILEDESC_XUNLOCK(fdesc); 2091 error = EMSGSIZE; 2092 unp_freerights(fdep, newfds); 2093 m_freem(*controlp); 2094 *controlp = NULL; 2095 goto next; 2096 } 2097 for (i = 0; i < newfds; i++, fdp++) { 2098 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2099 (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0, 2100 &fdep[i]->fde_caps); 2101 unp_externalize_fp(fdep[i]->fde_file); 2102 } 2103 2104 /* 2105 * The new type indicates that the mbuf data refers to 2106 * kernel resources that may need to be released before 2107 * the mbuf is freed. 2108 */ 2109 m_chtype(*controlp, MT_EXTCONTROL); 2110 FILEDESC_XUNLOCK(fdesc); 2111 free(fdep[0], M_FILECAPS); 2112 } else { 2113 /* We can just copy anything else across. */ 2114 if (error || controlp == NULL) 2115 goto next; 2116 *controlp = sbcreatecontrol(NULL, datalen, 2117 cm->cmsg_type, cm->cmsg_level); 2118 if (*controlp == NULL) { 2119 error = ENOBUFS; 2120 goto next; 2121 } 2122 bcopy(data, 2123 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2124 datalen); 2125 } 2126 controlp = &(*controlp)->m_next; 2127 2128 next: 2129 if (CMSG_SPACE(datalen) < clen) { 2130 clen -= CMSG_SPACE(datalen); 2131 cm = (struct cmsghdr *) 2132 ((caddr_t)cm + CMSG_SPACE(datalen)); 2133 } else { 2134 clen = 0; 2135 cm = NULL; 2136 } 2137 } 2138 2139 m_freem(control); 2140 return (error); 2141 } 2142 2143 static void 2144 unp_zone_change(void *tag) 2145 { 2146 2147 uma_zone_set_max(unp_zone, maxsockets); 2148 } 2149 2150 static void 2151 unp_init(void) 2152 { 2153 2154 #ifdef VIMAGE 2155 if (!IS_DEFAULT_VNET(curvnet)) 2156 return; 2157 #endif 2158 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 2159 NULL, NULL, UMA_ALIGN_CACHE, 0); 2160 if (unp_zone == NULL) 2161 panic("unp_init"); 2162 uma_zone_set_max(unp_zone, maxsockets); 2163 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2164 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2165 NULL, EVENTHANDLER_PRI_ANY); 2166 LIST_INIT(&unp_dhead); 2167 LIST_INIT(&unp_shead); 2168 LIST_INIT(&unp_sphead); 2169 SLIST_INIT(&unp_defers); 2170 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2171 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2172 UNP_LINK_LOCK_INIT(); 2173 UNP_DEFERRED_LOCK_INIT(); 2174 } 2175 2176 static void 2177 unp_internalize_cleanup_rights(struct mbuf *control) 2178 { 2179 struct cmsghdr *cp; 2180 struct mbuf *m; 2181 void *data; 2182 socklen_t datalen; 2183 2184 for (m = control; m != NULL; m = m->m_next) { 2185 cp = mtod(m, struct cmsghdr *); 2186 if (cp->cmsg_level != SOL_SOCKET || 2187 cp->cmsg_type != SCM_RIGHTS) 2188 continue; 2189 data = CMSG_DATA(cp); 2190 datalen = (caddr_t)cp + cp->cmsg_len - (caddr_t)data; 2191 unp_freerights(data, datalen / sizeof(struct filedesc *)); 2192 } 2193 } 2194 2195 static int 2196 unp_internalize(struct mbuf **controlp, struct thread *td) 2197 { 2198 struct mbuf *control, **initial_controlp; 2199 struct proc *p; 2200 struct filedesc *fdesc; 2201 struct bintime *bt; 2202 struct cmsghdr *cm; 2203 struct cmsgcred *cmcred; 2204 struct filedescent *fde, **fdep, *fdev; 2205 struct file *fp; 2206 struct timeval *tv; 2207 struct timespec *ts; 2208 void *data; 2209 socklen_t clen, datalen; 2210 int i, j, error, *fdp, oldfds; 2211 u_int newlen; 2212 2213 UNP_LINK_UNLOCK_ASSERT(); 2214 2215 p = td->td_proc; 2216 fdesc = p->p_fd; 2217 error = 0; 2218 control = *controlp; 2219 clen = control->m_len; 2220 *controlp = NULL; 2221 initial_controlp = controlp; 2222 for (cm = mtod(control, struct cmsghdr *); cm != NULL;) { 2223 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2224 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2225 error = EINVAL; 2226 goto out; 2227 } 2228 data = CMSG_DATA(cm); 2229 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2230 2231 switch (cm->cmsg_type) { 2232 /* 2233 * Fill in credential information. 2234 */ 2235 case SCM_CREDS: 2236 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2237 SCM_CREDS, SOL_SOCKET); 2238 if (*controlp == NULL) { 2239 error = ENOBUFS; 2240 goto out; 2241 } 2242 cmcred = (struct cmsgcred *) 2243 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2244 cmcred->cmcred_pid = p->p_pid; 2245 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2246 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2247 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2248 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2249 CMGROUP_MAX); 2250 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2251 cmcred->cmcred_groups[i] = 2252 td->td_ucred->cr_groups[i]; 2253 break; 2254 2255 case SCM_RIGHTS: 2256 oldfds = datalen / sizeof (int); 2257 if (oldfds == 0) 2258 break; 2259 /* 2260 * Check that all the FDs passed in refer to legal 2261 * files. If not, reject the entire operation. 2262 */ 2263 fdp = data; 2264 FILEDESC_SLOCK(fdesc); 2265 for (i = 0; i < oldfds; i++, fdp++) { 2266 fp = fget_locked(fdesc, *fdp); 2267 if (fp == NULL) { 2268 FILEDESC_SUNLOCK(fdesc); 2269 error = EBADF; 2270 goto out; 2271 } 2272 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2273 FILEDESC_SUNLOCK(fdesc); 2274 error = EOPNOTSUPP; 2275 goto out; 2276 } 2277 2278 } 2279 2280 /* 2281 * Now replace the integer FDs with pointers to the 2282 * file structure and capability rights. 2283 */ 2284 newlen = oldfds * sizeof(fdep[0]); 2285 *controlp = sbcreatecontrol(NULL, newlen, 2286 SCM_RIGHTS, SOL_SOCKET); 2287 if (*controlp == NULL) { 2288 FILEDESC_SUNLOCK(fdesc); 2289 error = E2BIG; 2290 goto out; 2291 } 2292 fdp = data; 2293 for (i = 0; i < oldfds; i++, fdp++) { 2294 if (!fhold(fdesc->fd_ofiles[*fdp].fde_file)) { 2295 fdp = data; 2296 for (j = 0; j < i; j++, fdp++) { 2297 fdrop(fdesc->fd_ofiles[*fdp]. 2298 fde_file, td); 2299 } 2300 FILEDESC_SUNLOCK(fdesc); 2301 error = EBADF; 2302 goto out; 2303 } 2304 } 2305 fdp = data; 2306 fdep = (struct filedescent **) 2307 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2308 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2309 M_WAITOK); 2310 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2311 fde = &fdesc->fd_ofiles[*fdp]; 2312 fdep[i] = fdev; 2313 fdep[i]->fde_file = fde->fde_file; 2314 filecaps_copy(&fde->fde_caps, 2315 &fdep[i]->fde_caps, true); 2316 unp_internalize_fp(fdep[i]->fde_file); 2317 } 2318 FILEDESC_SUNLOCK(fdesc); 2319 break; 2320 2321 case SCM_TIMESTAMP: 2322 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2323 SCM_TIMESTAMP, SOL_SOCKET); 2324 if (*controlp == NULL) { 2325 error = ENOBUFS; 2326 goto out; 2327 } 2328 tv = (struct timeval *) 2329 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2330 microtime(tv); 2331 break; 2332 2333 case SCM_BINTIME: 2334 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2335 SCM_BINTIME, SOL_SOCKET); 2336 if (*controlp == NULL) { 2337 error = ENOBUFS; 2338 goto out; 2339 } 2340 bt = (struct bintime *) 2341 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2342 bintime(bt); 2343 break; 2344 2345 case SCM_REALTIME: 2346 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2347 SCM_REALTIME, SOL_SOCKET); 2348 if (*controlp == NULL) { 2349 error = ENOBUFS; 2350 goto out; 2351 } 2352 ts = (struct timespec *) 2353 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2354 nanotime(ts); 2355 break; 2356 2357 case SCM_MONOTONIC: 2358 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2359 SCM_MONOTONIC, SOL_SOCKET); 2360 if (*controlp == NULL) { 2361 error = ENOBUFS; 2362 goto out; 2363 } 2364 ts = (struct timespec *) 2365 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2366 nanouptime(ts); 2367 break; 2368 2369 default: 2370 error = EINVAL; 2371 goto out; 2372 } 2373 2374 if (*controlp != NULL) 2375 controlp = &(*controlp)->m_next; 2376 if (CMSG_SPACE(datalen) < clen) { 2377 clen -= CMSG_SPACE(datalen); 2378 cm = (struct cmsghdr *) 2379 ((caddr_t)cm + CMSG_SPACE(datalen)); 2380 } else { 2381 clen = 0; 2382 cm = NULL; 2383 } 2384 } 2385 2386 out: 2387 if (error != 0 && initial_controlp != NULL) 2388 unp_internalize_cleanup_rights(*initial_controlp); 2389 m_freem(control); 2390 return (error); 2391 } 2392 2393 static struct mbuf * 2394 unp_addsockcred(struct thread *td, struct mbuf *control) 2395 { 2396 struct mbuf *m, *n, *n_prev; 2397 struct sockcred *sc; 2398 const struct cmsghdr *cm; 2399 int ngroups; 2400 int i; 2401 2402 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2403 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 2404 if (m == NULL) 2405 return (control); 2406 2407 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 2408 sc->sc_uid = td->td_ucred->cr_ruid; 2409 sc->sc_euid = td->td_ucred->cr_uid; 2410 sc->sc_gid = td->td_ucred->cr_rgid; 2411 sc->sc_egid = td->td_ucred->cr_gid; 2412 sc->sc_ngroups = ngroups; 2413 for (i = 0; i < sc->sc_ngroups; i++) 2414 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2415 2416 /* 2417 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2418 * created SCM_CREDS control message (struct sockcred) has another 2419 * format. 2420 */ 2421 if (control != NULL) 2422 for (n = control, n_prev = NULL; n != NULL;) { 2423 cm = mtod(n, struct cmsghdr *); 2424 if (cm->cmsg_level == SOL_SOCKET && 2425 cm->cmsg_type == SCM_CREDS) { 2426 if (n_prev == NULL) 2427 control = n->m_next; 2428 else 2429 n_prev->m_next = n->m_next; 2430 n = m_free(n); 2431 } else { 2432 n_prev = n; 2433 n = n->m_next; 2434 } 2435 } 2436 2437 /* Prepend it to the head. */ 2438 m->m_next = control; 2439 return (m); 2440 } 2441 2442 static struct unpcb * 2443 fptounp(struct file *fp) 2444 { 2445 struct socket *so; 2446 2447 if (fp->f_type != DTYPE_SOCKET) 2448 return (NULL); 2449 if ((so = fp->f_data) == NULL) 2450 return (NULL); 2451 if (so->so_proto->pr_domain != &localdomain) 2452 return (NULL); 2453 return sotounpcb(so); 2454 } 2455 2456 static void 2457 unp_discard(struct file *fp) 2458 { 2459 struct unp_defer *dr; 2460 2461 if (unp_externalize_fp(fp)) { 2462 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2463 dr->ud_fp = fp; 2464 UNP_DEFERRED_LOCK(); 2465 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2466 UNP_DEFERRED_UNLOCK(); 2467 atomic_add_int(&unp_defers_count, 1); 2468 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2469 } else 2470 (void) closef(fp, (struct thread *)NULL); 2471 } 2472 2473 static void 2474 unp_process_defers(void *arg __unused, int pending) 2475 { 2476 struct unp_defer *dr; 2477 SLIST_HEAD(, unp_defer) drl; 2478 int count; 2479 2480 SLIST_INIT(&drl); 2481 for (;;) { 2482 UNP_DEFERRED_LOCK(); 2483 if (SLIST_FIRST(&unp_defers) == NULL) { 2484 UNP_DEFERRED_UNLOCK(); 2485 break; 2486 } 2487 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2488 UNP_DEFERRED_UNLOCK(); 2489 count = 0; 2490 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2491 SLIST_REMOVE_HEAD(&drl, ud_link); 2492 closef(dr->ud_fp, NULL); 2493 free(dr, M_TEMP); 2494 count++; 2495 } 2496 atomic_add_int(&unp_defers_count, -count); 2497 } 2498 } 2499 2500 static void 2501 unp_internalize_fp(struct file *fp) 2502 { 2503 struct unpcb *unp; 2504 2505 UNP_LINK_WLOCK(); 2506 if ((unp = fptounp(fp)) != NULL) { 2507 unp->unp_file = fp; 2508 unp->unp_msgcount++; 2509 } 2510 unp_rights++; 2511 UNP_LINK_WUNLOCK(); 2512 } 2513 2514 static int 2515 unp_externalize_fp(struct file *fp) 2516 { 2517 struct unpcb *unp; 2518 int ret; 2519 2520 UNP_LINK_WLOCK(); 2521 if ((unp = fptounp(fp)) != NULL) { 2522 unp->unp_msgcount--; 2523 ret = 1; 2524 } else 2525 ret = 0; 2526 unp_rights--; 2527 UNP_LINK_WUNLOCK(); 2528 return (ret); 2529 } 2530 2531 /* 2532 * unp_defer indicates whether additional work has been defered for a future 2533 * pass through unp_gc(). It is thread local and does not require explicit 2534 * synchronization. 2535 */ 2536 static int unp_marked; 2537 2538 static void 2539 unp_remove_dead_ref(struct filedescent **fdep, int fdcount) 2540 { 2541 struct unpcb *unp; 2542 struct file *fp; 2543 int i; 2544 2545 /* 2546 * This function can only be called from the gc task. 2547 */ 2548 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2549 ("%s: not on gc callout", __func__)); 2550 UNP_LINK_LOCK_ASSERT(); 2551 2552 for (i = 0; i < fdcount; i++) { 2553 fp = fdep[i]->fde_file; 2554 if ((unp = fptounp(fp)) == NULL) 2555 continue; 2556 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2557 continue; 2558 unp->unp_gcrefs--; 2559 } 2560 } 2561 2562 static void 2563 unp_restore_undead_ref(struct filedescent **fdep, int fdcount) 2564 { 2565 struct unpcb *unp; 2566 struct file *fp; 2567 int i; 2568 2569 /* 2570 * This function can only be called from the gc task. 2571 */ 2572 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2573 ("%s: not on gc callout", __func__)); 2574 UNP_LINK_LOCK_ASSERT(); 2575 2576 for (i = 0; i < fdcount; i++) { 2577 fp = fdep[i]->fde_file; 2578 if ((unp = fptounp(fp)) == NULL) 2579 continue; 2580 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2581 continue; 2582 unp->unp_gcrefs++; 2583 unp_marked++; 2584 } 2585 } 2586 2587 static void 2588 unp_gc_scan(struct unpcb *unp, void (*op)(struct filedescent **, int)) 2589 { 2590 struct socket *so, *soa; 2591 2592 so = unp->unp_socket; 2593 SOCK_LOCK(so); 2594 if (SOLISTENING(so)) { 2595 /* 2596 * Mark all sockets in our accept queue. 2597 */ 2598 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2599 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2600 continue; 2601 SOCKBUF_LOCK(&soa->so_rcv); 2602 unp_scan(soa->so_rcv.sb_mb, op); 2603 SOCKBUF_UNLOCK(&soa->so_rcv); 2604 } 2605 } else { 2606 /* 2607 * Mark all sockets we reference with RIGHTS. 2608 */ 2609 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2610 SOCKBUF_LOCK(&so->so_rcv); 2611 unp_scan(so->so_rcv.sb_mb, op); 2612 SOCKBUF_UNLOCK(&so->so_rcv); 2613 } 2614 } 2615 SOCK_UNLOCK(so); 2616 } 2617 2618 static int unp_recycled; 2619 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2620 "Number of unreachable sockets claimed by the garbage collector."); 2621 2622 static int unp_taskcount; 2623 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2624 "Number of times the garbage collector has run."); 2625 2626 SYSCTL_UINT(_net_local, OID_AUTO, sockcount, CTLFLAG_RD, &unp_count, 0, 2627 "Number of active local sockets."); 2628 2629 static void 2630 unp_gc(__unused void *arg, int pending) 2631 { 2632 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2633 NULL }; 2634 struct unp_head **head; 2635 struct unp_head unp_deadhead; /* List of potentially-dead sockets. */ 2636 struct file *f, **unref; 2637 struct unpcb *unp, *unptmp; 2638 int i, total, unp_unreachable; 2639 2640 LIST_INIT(&unp_deadhead); 2641 unp_taskcount++; 2642 UNP_LINK_RLOCK(); 2643 /* 2644 * First determine which sockets may be in cycles. 2645 */ 2646 unp_unreachable = 0; 2647 2648 for (head = heads; *head != NULL; head++) 2649 LIST_FOREACH(unp, *head, unp_link) { 2650 2651 KASSERT((unp->unp_gcflag & ~UNPGC_IGNORE_RIGHTS) == 0, 2652 ("%s: unp %p has unexpected gc flags 0x%x", 2653 __func__, unp, (unsigned int)unp->unp_gcflag)); 2654 2655 f = unp->unp_file; 2656 2657 /* 2658 * Check for an unreachable socket potentially in a 2659 * cycle. It must be in a queue as indicated by 2660 * msgcount, and this must equal the file reference 2661 * count. Note that when msgcount is 0 the file is 2662 * NULL. 2663 */ 2664 if (f != NULL && unp->unp_msgcount != 0 && 2665 f->f_count == unp->unp_msgcount) { 2666 LIST_INSERT_HEAD(&unp_deadhead, unp, unp_dead); 2667 unp->unp_gcflag |= UNPGC_DEAD; 2668 unp->unp_gcrefs = unp->unp_msgcount; 2669 unp_unreachable++; 2670 } 2671 } 2672 2673 /* 2674 * Scan all sockets previously marked as potentially being in a cycle 2675 * and remove the references each socket holds on any UNPGC_DEAD 2676 * sockets in its queue. After this step, all remaining references on 2677 * sockets marked UNPGC_DEAD should not be part of any cycle. 2678 */ 2679 LIST_FOREACH(unp, &unp_deadhead, unp_dead) 2680 unp_gc_scan(unp, unp_remove_dead_ref); 2681 2682 /* 2683 * If a socket still has a non-negative refcount, it cannot be in a 2684 * cycle. In this case increment refcount of all children iteratively. 2685 * Stop the scan once we do a complete loop without discovering 2686 * a new reachable socket. 2687 */ 2688 do { 2689 unp_marked = 0; 2690 LIST_FOREACH_SAFE(unp, &unp_deadhead, unp_dead, unptmp) 2691 if (unp->unp_gcrefs > 0) { 2692 unp->unp_gcflag &= ~UNPGC_DEAD; 2693 LIST_REMOVE(unp, unp_dead); 2694 KASSERT(unp_unreachable > 0, 2695 ("%s: unp_unreachable underflow.", 2696 __func__)); 2697 unp_unreachable--; 2698 unp_gc_scan(unp, unp_restore_undead_ref); 2699 } 2700 } while (unp_marked); 2701 2702 UNP_LINK_RUNLOCK(); 2703 2704 if (unp_unreachable == 0) 2705 return; 2706 2707 /* 2708 * Allocate space for a local array of dead unpcbs. 2709 * TODO: can this path be simplified by instead using the local 2710 * dead list at unp_deadhead, after taking out references 2711 * on the file object and/or unpcb and dropping the link lock? 2712 */ 2713 unref = malloc(unp_unreachable * sizeof(struct file *), 2714 M_TEMP, M_WAITOK); 2715 2716 /* 2717 * Iterate looking for sockets which have been specifically marked 2718 * as unreachable and store them locally. 2719 */ 2720 UNP_LINK_RLOCK(); 2721 total = 0; 2722 LIST_FOREACH(unp, &unp_deadhead, unp_dead) { 2723 KASSERT((unp->unp_gcflag & UNPGC_DEAD) != 0, 2724 ("%s: unp %p not marked UNPGC_DEAD", __func__, unp)); 2725 unp->unp_gcflag &= ~UNPGC_DEAD; 2726 f = unp->unp_file; 2727 if (unp->unp_msgcount == 0 || f == NULL || 2728 f->f_count != unp->unp_msgcount || 2729 !fhold(f)) 2730 continue; 2731 unref[total++] = f; 2732 KASSERT(total <= unp_unreachable, 2733 ("%s: incorrect unreachable count.", __func__)); 2734 } 2735 UNP_LINK_RUNLOCK(); 2736 2737 /* 2738 * Now flush all sockets, free'ing rights. This will free the 2739 * struct files associated with these sockets but leave each socket 2740 * with one remaining ref. 2741 */ 2742 for (i = 0; i < total; i++) { 2743 struct socket *so; 2744 2745 so = unref[i]->f_data; 2746 CURVNET_SET(so->so_vnet); 2747 sorflush(so); 2748 CURVNET_RESTORE(); 2749 } 2750 2751 /* 2752 * And finally release the sockets so they can be reclaimed. 2753 */ 2754 for (i = 0; i < total; i++) 2755 fdrop(unref[i], NULL); 2756 unp_recycled += total; 2757 free(unref, M_TEMP); 2758 } 2759 2760 static void 2761 unp_dispose_mbuf(struct mbuf *m) 2762 { 2763 2764 if (m) 2765 unp_scan(m, unp_freerights); 2766 } 2767 2768 /* 2769 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2770 */ 2771 static void 2772 unp_dispose(struct socket *so) 2773 { 2774 struct unpcb *unp; 2775 2776 unp = sotounpcb(so); 2777 UNP_LINK_WLOCK(); 2778 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2779 UNP_LINK_WUNLOCK(); 2780 if (!SOLISTENING(so)) 2781 unp_dispose_mbuf(so->so_rcv.sb_mb); 2782 } 2783 2784 static void 2785 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2786 { 2787 struct mbuf *m; 2788 struct cmsghdr *cm; 2789 void *data; 2790 socklen_t clen, datalen; 2791 2792 while (m0 != NULL) { 2793 for (m = m0; m; m = m->m_next) { 2794 if (m->m_type != MT_CONTROL) 2795 continue; 2796 2797 cm = mtod(m, struct cmsghdr *); 2798 clen = m->m_len; 2799 2800 while (cm != NULL) { 2801 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2802 break; 2803 2804 data = CMSG_DATA(cm); 2805 datalen = (caddr_t)cm + cm->cmsg_len 2806 - (caddr_t)data; 2807 2808 if (cm->cmsg_level == SOL_SOCKET && 2809 cm->cmsg_type == SCM_RIGHTS) { 2810 (*op)(data, datalen / 2811 sizeof(struct filedescent *)); 2812 } 2813 2814 if (CMSG_SPACE(datalen) < clen) { 2815 clen -= CMSG_SPACE(datalen); 2816 cm = (struct cmsghdr *) 2817 ((caddr_t)cm + CMSG_SPACE(datalen)); 2818 } else { 2819 clen = 0; 2820 cm = NULL; 2821 } 2822 } 2823 } 2824 m0 = m0->m_nextpkt; 2825 } 2826 } 2827 2828 /* 2829 * A helper function called by VFS before socket-type vnode reclamation. 2830 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2831 * use count. 2832 */ 2833 void 2834 vfs_unp_reclaim(struct vnode *vp) 2835 { 2836 struct unpcb *unp; 2837 int active; 2838 struct mtx *vplock; 2839 2840 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2841 KASSERT(vp->v_type == VSOCK, 2842 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2843 2844 active = 0; 2845 vplock = mtx_pool_find(mtxpool_sleep, vp); 2846 mtx_lock(vplock); 2847 VOP_UNP_CONNECT(vp, &unp); 2848 if (unp == NULL) 2849 goto done; 2850 UNP_PCB_LOCK(unp); 2851 if (unp->unp_vnode == vp) { 2852 VOP_UNP_DETACH(vp); 2853 unp->unp_vnode = NULL; 2854 active = 1; 2855 } 2856 UNP_PCB_UNLOCK(unp); 2857 done: 2858 mtx_unlock(vplock); 2859 if (active) 2860 vunref(vp); 2861 } 2862 2863 #ifdef DDB 2864 static void 2865 db_print_indent(int indent) 2866 { 2867 int i; 2868 2869 for (i = 0; i < indent; i++) 2870 db_printf(" "); 2871 } 2872 2873 static void 2874 db_print_unpflags(int unp_flags) 2875 { 2876 int comma; 2877 2878 comma = 0; 2879 if (unp_flags & UNP_HAVEPC) { 2880 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2881 comma = 1; 2882 } 2883 if (unp_flags & UNP_WANTCRED) { 2884 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2885 comma = 1; 2886 } 2887 if (unp_flags & UNP_CONNWAIT) { 2888 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2889 comma = 1; 2890 } 2891 if (unp_flags & UNP_CONNECTING) { 2892 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2893 comma = 1; 2894 } 2895 if (unp_flags & UNP_BINDING) { 2896 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2897 comma = 1; 2898 } 2899 } 2900 2901 static void 2902 db_print_xucred(int indent, struct xucred *xu) 2903 { 2904 int comma, i; 2905 2906 db_print_indent(indent); 2907 db_printf("cr_version: %u cr_uid: %u cr_pid: %d cr_ngroups: %d\n", 2908 xu->cr_version, xu->cr_uid, xu->cr_pid, xu->cr_ngroups); 2909 db_print_indent(indent); 2910 db_printf("cr_groups: "); 2911 comma = 0; 2912 for (i = 0; i < xu->cr_ngroups; i++) { 2913 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2914 comma = 1; 2915 } 2916 db_printf("\n"); 2917 } 2918 2919 static void 2920 db_print_unprefs(int indent, struct unp_head *uh) 2921 { 2922 struct unpcb *unp; 2923 int counter; 2924 2925 counter = 0; 2926 LIST_FOREACH(unp, uh, unp_reflink) { 2927 if (counter % 4 == 0) 2928 db_print_indent(indent); 2929 db_printf("%p ", unp); 2930 if (counter % 4 == 3) 2931 db_printf("\n"); 2932 counter++; 2933 } 2934 if (counter != 0 && counter % 4 != 0) 2935 db_printf("\n"); 2936 } 2937 2938 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2939 { 2940 struct unpcb *unp; 2941 2942 if (!have_addr) { 2943 db_printf("usage: show unpcb <addr>\n"); 2944 return; 2945 } 2946 unp = (struct unpcb *)addr; 2947 2948 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2949 unp->unp_vnode); 2950 2951 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2952 unp->unp_conn); 2953 2954 db_printf("unp_refs:\n"); 2955 db_print_unprefs(2, &unp->unp_refs); 2956 2957 /* XXXRW: Would be nice to print the full address, if any. */ 2958 db_printf("unp_addr: %p\n", unp->unp_addr); 2959 2960 db_printf("unp_gencnt: %llu\n", 2961 (unsigned long long)unp->unp_gencnt); 2962 2963 db_printf("unp_flags: %x (", unp->unp_flags); 2964 db_print_unpflags(unp->unp_flags); 2965 db_printf(")\n"); 2966 2967 db_printf("unp_peercred:\n"); 2968 db_print_xucred(2, &unp->unp_peercred); 2969 2970 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2971 } 2972 #endif 2973