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 UNP_LINK_WLOCK(); 779 LIST_REMOVE(unp, unp_link); 780 if (unp->unp_gcflag & UNPGC_DEAD) 781 LIST_REMOVE(unp, unp_dead); 782 unp->unp_gencnt = ++unp_gencnt; 783 --unp_count; 784 UNP_LINK_WUNLOCK(); 785 786 UNP_PCB_UNLOCK_ASSERT(unp); 787 restart: 788 if ((vp = unp->unp_vnode) != NULL) { 789 vplock = mtx_pool_find(mtxpool_sleep, vp); 790 mtx_lock(vplock); 791 } 792 UNP_PCB_LOCK(unp); 793 if (unp->unp_vnode != vp && unp->unp_vnode != NULL) { 794 if (vplock) 795 mtx_unlock(vplock); 796 UNP_PCB_UNLOCK(unp); 797 goto restart; 798 } 799 if ((vp = unp->unp_vnode) != NULL) { 800 VOP_UNP_DETACH(vp); 801 unp->unp_vnode = NULL; 802 } 803 if (__predict_false(unp == unp->unp_conn)) { 804 unp_disconnect(unp, unp); 805 unp2 = NULL; 806 } else { 807 if ((unp2 = unp->unp_conn) != NULL) { 808 unp_pcb_owned_lock2(unp, unp2, freeunp); 809 if (freeunp) 810 unp2 = NULL; 811 } 812 unp_pcb_hold(unp); 813 if (unp2 != NULL) { 814 unp_pcb_hold(unp2); 815 unp_disconnect(unp, unp2); 816 if (unp_pcb_rele(unp2) == 0) 817 UNP_PCB_UNLOCK(unp2); 818 } 819 } 820 UNP_PCB_UNLOCK(unp); 821 UNP_REF_LIST_LOCK(); 822 while (!LIST_EMPTY(&unp->unp_refs)) { 823 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 824 825 unp_pcb_hold(ref); 826 UNP_REF_LIST_UNLOCK(); 827 828 MPASS(ref != unp); 829 UNP_PCB_UNLOCK_ASSERT(ref); 830 unp_drop(ref); 831 UNP_REF_LIST_LOCK(); 832 } 833 834 UNP_REF_LIST_UNLOCK(); 835 UNP_PCB_LOCK(unp); 836 freeunp = unp_pcb_rele(unp); 837 MPASS(freeunp == 0); 838 local_unp_rights = unp_rights; 839 unp->unp_socket->so_pcb = NULL; 840 unp->unp_socket = NULL; 841 free(unp->unp_addr, M_SONAME); 842 unp->unp_addr = NULL; 843 if (!unp_pcb_rele(unp)) 844 UNP_PCB_UNLOCK(unp); 845 if (vp) { 846 mtx_unlock(vplock); 847 vrele(vp); 848 } 849 if (local_unp_rights) 850 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 851 } 852 853 static int 854 uipc_disconnect(struct socket *so) 855 { 856 struct unpcb *unp, *unp2; 857 int freed; 858 859 unp = sotounpcb(so); 860 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 861 862 UNP_PCB_LOCK(unp); 863 if ((unp2 = unp->unp_conn) == NULL) { 864 UNP_PCB_UNLOCK(unp); 865 return (0); 866 } 867 if (__predict_true(unp != unp2)) { 868 unp_pcb_owned_lock2(unp, unp2, freed); 869 if (__predict_false(freed)) { 870 UNP_PCB_UNLOCK(unp); 871 return (0); 872 } 873 unp_pcb_hold(unp2); 874 } 875 unp_pcb_hold(unp); 876 unp_disconnect(unp, unp2); 877 if (unp_pcb_rele(unp) == 0) 878 UNP_PCB_UNLOCK(unp); 879 if ((unp != unp2) && unp_pcb_rele(unp2) == 0) 880 UNP_PCB_UNLOCK(unp2); 881 return (0); 882 } 883 884 static int 885 uipc_listen(struct socket *so, int backlog, struct thread *td) 886 { 887 struct unpcb *unp; 888 int error; 889 890 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 891 return (EOPNOTSUPP); 892 893 unp = sotounpcb(so); 894 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 895 896 UNP_PCB_LOCK(unp); 897 if (unp->unp_vnode == NULL) { 898 /* Already connected or not bound to an address. */ 899 error = unp->unp_conn != NULL ? EINVAL : EDESTADDRREQ; 900 UNP_PCB_UNLOCK(unp); 901 return (error); 902 } 903 904 SOCK_LOCK(so); 905 error = solisten_proto_check(so); 906 if (error == 0) { 907 cru2xt(td, &unp->unp_peercred); 908 solisten_proto(so, backlog); 909 } 910 SOCK_UNLOCK(so); 911 UNP_PCB_UNLOCK(unp); 912 return (error); 913 } 914 915 static int 916 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 917 { 918 struct unpcb *unp, *unp2; 919 const struct sockaddr *sa; 920 921 unp = sotounpcb(so); 922 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 923 924 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 925 UNP_LINK_RLOCK(); 926 /* 927 * XXX: It seems that this test always fails even when connection is 928 * established. So, this else clause is added as workaround to 929 * return PF_LOCAL sockaddr. 930 */ 931 unp2 = unp->unp_conn; 932 if (unp2 != NULL) { 933 UNP_PCB_LOCK(unp2); 934 if (unp2->unp_addr != NULL) 935 sa = (struct sockaddr *) unp2->unp_addr; 936 else 937 sa = &sun_noname; 938 bcopy(sa, *nam, sa->sa_len); 939 UNP_PCB_UNLOCK(unp2); 940 } else { 941 sa = &sun_noname; 942 bcopy(sa, *nam, sa->sa_len); 943 } 944 UNP_LINK_RUNLOCK(); 945 return (0); 946 } 947 948 static int 949 uipc_rcvd(struct socket *so, int flags) 950 { 951 struct unpcb *unp, *unp2; 952 struct socket *so2; 953 u_int mbcnt, sbcc; 954 955 unp = sotounpcb(so); 956 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 957 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 958 ("%s: socktype %d", __func__, so->so_type)); 959 960 /* 961 * Adjust backpressure on sender and wakeup any waiting to write. 962 * 963 * The unp lock is acquired to maintain the validity of the unp_conn 964 * pointer; no lock on unp2 is required as unp2->unp_socket will be 965 * static as long as we don't permit unp2 to disconnect from unp, 966 * which is prevented by the lock on unp. We cache values from 967 * so_rcv to avoid holding the so_rcv lock over the entire 968 * transaction on the remote so_snd. 969 */ 970 SOCKBUF_LOCK(&so->so_rcv); 971 mbcnt = so->so_rcv.sb_mbcnt; 972 sbcc = sbavail(&so->so_rcv); 973 SOCKBUF_UNLOCK(&so->so_rcv); 974 /* 975 * There is a benign race condition at this point. If we're planning to 976 * clear SB_STOP, but uipc_send is called on the connected socket at 977 * this instant, it might add data to the sockbuf and set SB_STOP. Then 978 * we would erroneously clear SB_STOP below, even though the sockbuf is 979 * full. The race is benign because the only ill effect is to allow the 980 * sockbuf to exceed its size limit, and the size limits are not 981 * strictly guaranteed anyway. 982 */ 983 UNP_PCB_LOCK(unp); 984 unp2 = unp->unp_conn; 985 if (unp2 == NULL) { 986 UNP_PCB_UNLOCK(unp); 987 return (0); 988 } 989 so2 = unp2->unp_socket; 990 SOCKBUF_LOCK(&so2->so_snd); 991 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 992 so2->so_snd.sb_flags &= ~SB_STOP; 993 sowwakeup_locked(so2); 994 UNP_PCB_UNLOCK(unp); 995 return (0); 996 } 997 998 static int 999 connect_internal(struct socket *so, struct sockaddr *nam, struct thread *td) 1000 { 1001 int error; 1002 struct unpcb *unp; 1003 1004 unp = so->so_pcb; 1005 if (unp->unp_conn != NULL) 1006 return (EISCONN); 1007 error = unp_connect(so, nam, td); 1008 if (error) 1009 return (error); 1010 UNP_PCB_LOCK(unp); 1011 if (unp->unp_conn == NULL) { 1012 UNP_PCB_UNLOCK(unp); 1013 if (error == 0) 1014 error = ENOTCONN; 1015 } 1016 return (error); 1017 } 1018 1019 static int 1020 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 1021 struct mbuf *control, struct thread *td) 1022 { 1023 struct unpcb *unp, *unp2; 1024 struct socket *so2; 1025 u_int mbcnt, sbcc; 1026 int freed, error; 1027 1028 unp = sotounpcb(so); 1029 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 1030 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 1031 so->so_type == SOCK_SEQPACKET, 1032 ("%s: socktype %d", __func__, so->so_type)); 1033 1034 freed = error = 0; 1035 if (flags & PRUS_OOB) { 1036 error = EOPNOTSUPP; 1037 goto release; 1038 } 1039 if (control != NULL && (error = unp_internalize(&control, td))) 1040 goto release; 1041 1042 unp2 = NULL; 1043 switch (so->so_type) { 1044 case SOCK_DGRAM: 1045 { 1046 const struct sockaddr *from; 1047 1048 if (nam != NULL) { 1049 /* 1050 * We return with UNP_PCB_LOCK_HELD so we know that 1051 * the reference is live if the pointer is valid. 1052 */ 1053 if ((error = connect_internal(so, nam, td))) 1054 break; 1055 MPASS(unp->unp_conn != NULL); 1056 unp2 = unp->unp_conn; 1057 } else { 1058 UNP_PCB_LOCK(unp); 1059 1060 /* 1061 * Because connect() and send() are non-atomic in a sendto() 1062 * with a target address, it's possible that the socket will 1063 * have disconnected before the send() can run. In that case 1064 * return the slightly counter-intuitive but otherwise 1065 * correct error that the socket is not connected. 1066 */ 1067 if ((unp2 = unp->unp_conn) == NULL) { 1068 UNP_PCB_UNLOCK(unp); 1069 error = ENOTCONN; 1070 break; 1071 } 1072 } 1073 if (__predict_false(unp == unp2)) { 1074 if (unp->unp_socket == NULL) { 1075 error = ENOTCONN; 1076 break; 1077 } 1078 goto connect_self; 1079 } 1080 unp_pcb_owned_lock2(unp, unp2, freed); 1081 if (__predict_false(freed)) { 1082 UNP_PCB_UNLOCK(unp); 1083 error = ENOTCONN; 1084 break; 1085 } 1086 /* 1087 * The socket referencing unp2 may have been closed 1088 * or unp may have been disconnected if the unp lock 1089 * was dropped to acquire unp2. 1090 */ 1091 if (__predict_false(unp->unp_conn == NULL) || 1092 unp2->unp_socket == NULL) { 1093 UNP_PCB_UNLOCK(unp); 1094 if (unp_pcb_rele(unp2) == 0) 1095 UNP_PCB_UNLOCK(unp2); 1096 error = ENOTCONN; 1097 break; 1098 } 1099 connect_self: 1100 if (unp2->unp_flags & UNP_WANTCRED) 1101 control = unp_addsockcred(td, control); 1102 if (unp->unp_addr != NULL) 1103 from = (struct sockaddr *)unp->unp_addr; 1104 else 1105 from = &sun_noname; 1106 so2 = unp2->unp_socket; 1107 SOCKBUF_LOCK(&so2->so_rcv); 1108 if (sbappendaddr_locked(&so2->so_rcv, from, m, 1109 control)) { 1110 sorwakeup_locked(so2); 1111 m = NULL; 1112 control = NULL; 1113 } else { 1114 SOCKBUF_UNLOCK(&so2->so_rcv); 1115 error = ENOBUFS; 1116 } 1117 if (nam != NULL) 1118 unp_disconnect(unp, unp2); 1119 if (__predict_true(unp != unp2)) 1120 UNP_PCB_UNLOCK(unp2); 1121 UNP_PCB_UNLOCK(unp); 1122 break; 1123 } 1124 1125 case SOCK_SEQPACKET: 1126 case SOCK_STREAM: 1127 if ((so->so_state & SS_ISCONNECTED) == 0) { 1128 if (nam != NULL) { 1129 if ((error = connect_internal(so, nam, td))) 1130 break; 1131 } else { 1132 error = ENOTCONN; 1133 break; 1134 } 1135 } else if ((unp2 = unp->unp_conn) == NULL) { 1136 error = ENOTCONN; 1137 break; 1138 } else if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 1139 error = EPIPE; 1140 break; 1141 } else { 1142 UNP_PCB_LOCK(unp); 1143 if ((unp2 = unp->unp_conn) == NULL) { 1144 UNP_PCB_UNLOCK(unp); 1145 error = ENOTCONN; 1146 break; 1147 } 1148 } 1149 unp_pcb_owned_lock2(unp, unp2, freed); 1150 UNP_PCB_UNLOCK(unp); 1151 if (__predict_false(freed)) { 1152 error = ENOTCONN; 1153 break; 1154 } 1155 if ((so2 = unp2->unp_socket) == NULL) { 1156 UNP_PCB_UNLOCK(unp2); 1157 error = ENOTCONN; 1158 break; 1159 } 1160 SOCKBUF_LOCK(&so2->so_rcv); 1161 if (unp2->unp_flags & UNP_WANTCRED) { 1162 /* 1163 * Credentials are passed only once on SOCK_STREAM 1164 * and SOCK_SEQPACKET. 1165 */ 1166 unp2->unp_flags &= ~UNP_WANTCRED; 1167 control = unp_addsockcred(td, control); 1168 } 1169 1170 /* 1171 * Send to paired receive port and wake up readers. Don't 1172 * check for space available in the receive buffer if we're 1173 * attaching ancillary data; Unix domain sockets only check 1174 * for space in the sending sockbuf, and that check is 1175 * performed one level up the stack. At that level we cannot 1176 * precisely account for the amount of buffer space used 1177 * (e.g., because control messages are not yet internalized). 1178 */ 1179 switch (so->so_type) { 1180 case SOCK_STREAM: 1181 if (control != NULL) { 1182 sbappendcontrol_locked(&so2->so_rcv, m, 1183 control); 1184 control = NULL; 1185 } else 1186 sbappend_locked(&so2->so_rcv, m, flags); 1187 break; 1188 1189 case SOCK_SEQPACKET: { 1190 const struct sockaddr *from; 1191 1192 from = &sun_noname; 1193 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 1194 from, m, control)) 1195 control = NULL; 1196 break; 1197 } 1198 } 1199 1200 mbcnt = so2->so_rcv.sb_mbcnt; 1201 sbcc = sbavail(&so2->so_rcv); 1202 if (sbcc) 1203 sorwakeup_locked(so2); 1204 else 1205 SOCKBUF_UNLOCK(&so2->so_rcv); 1206 1207 /* 1208 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1209 * it would be possible for uipc_rcvd to be called at this 1210 * point, drain the receiving sockbuf, clear SB_STOP, and then 1211 * we would set SB_STOP below. That could lead to an empty 1212 * sockbuf having SB_STOP set 1213 */ 1214 SOCKBUF_LOCK(&so->so_snd); 1215 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1216 so->so_snd.sb_flags |= SB_STOP; 1217 SOCKBUF_UNLOCK(&so->so_snd); 1218 UNP_PCB_UNLOCK(unp2); 1219 m = NULL; 1220 break; 1221 } 1222 1223 /* 1224 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1225 */ 1226 if (flags & PRUS_EOF) { 1227 UNP_PCB_LOCK(unp); 1228 socantsendmore(so); 1229 unp_shutdown(unp); 1230 UNP_PCB_UNLOCK(unp); 1231 } 1232 if (control != NULL && error != 0) 1233 unp_dispose_mbuf(control); 1234 1235 release: 1236 if (control != NULL) 1237 m_freem(control); 1238 /* 1239 * In case of PRUS_NOTREADY, uipc_ready() is responsible 1240 * for freeing memory. 1241 */ 1242 if (m != NULL && (flags & PRUS_NOTREADY) == 0) 1243 m_freem(m); 1244 return (error); 1245 } 1246 1247 static int 1248 uipc_ready(struct socket *so, struct mbuf *m, int count) 1249 { 1250 struct unpcb *unp, *unp2; 1251 struct socket *so2; 1252 int error; 1253 1254 unp = sotounpcb(so); 1255 1256 UNP_PCB_LOCK(unp); 1257 if ((unp2 = unp->unp_conn) == NULL) { 1258 UNP_PCB_UNLOCK(unp); 1259 goto error; 1260 } 1261 if (unp != unp2) { 1262 if (UNP_PCB_TRYLOCK(unp2) == 0) { 1263 unp_pcb_hold(unp2); 1264 UNP_PCB_UNLOCK(unp); 1265 UNP_PCB_LOCK(unp2); 1266 if (unp_pcb_rele(unp2)) 1267 goto error; 1268 } else 1269 UNP_PCB_UNLOCK(unp); 1270 } 1271 so2 = unp2->unp_socket; 1272 1273 SOCKBUF_LOCK(&so2->so_rcv); 1274 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1275 sorwakeup_locked(so2); 1276 else 1277 SOCKBUF_UNLOCK(&so2->so_rcv); 1278 1279 UNP_PCB_UNLOCK(unp2); 1280 1281 return (error); 1282 error: 1283 for (int i = 0; i < count; i++) 1284 m = m_free(m); 1285 return (ECONNRESET); 1286 } 1287 1288 static int 1289 uipc_sense(struct socket *so, struct stat *sb) 1290 { 1291 struct unpcb *unp; 1292 1293 unp = sotounpcb(so); 1294 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1295 1296 sb->st_blksize = so->so_snd.sb_hiwat; 1297 sb->st_dev = NODEV; 1298 sb->st_ino = unp->unp_ino; 1299 return (0); 1300 } 1301 1302 static int 1303 uipc_shutdown(struct socket *so) 1304 { 1305 struct unpcb *unp; 1306 1307 unp = sotounpcb(so); 1308 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1309 1310 UNP_PCB_LOCK(unp); 1311 socantsendmore(so); 1312 unp_shutdown(unp); 1313 UNP_PCB_UNLOCK(unp); 1314 return (0); 1315 } 1316 1317 static int 1318 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1319 { 1320 struct unpcb *unp; 1321 const struct sockaddr *sa; 1322 1323 unp = sotounpcb(so); 1324 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1325 1326 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1327 UNP_PCB_LOCK(unp); 1328 if (unp->unp_addr != NULL) 1329 sa = (struct sockaddr *) unp->unp_addr; 1330 else 1331 sa = &sun_noname; 1332 bcopy(sa, *nam, sa->sa_len); 1333 UNP_PCB_UNLOCK(unp); 1334 return (0); 1335 } 1336 1337 static struct pr_usrreqs uipc_usrreqs_dgram = { 1338 .pru_abort = uipc_abort, 1339 .pru_accept = uipc_accept, 1340 .pru_attach = uipc_attach, 1341 .pru_bind = uipc_bind, 1342 .pru_bindat = uipc_bindat, 1343 .pru_connect = uipc_connect, 1344 .pru_connectat = uipc_connectat, 1345 .pru_connect2 = uipc_connect2, 1346 .pru_detach = uipc_detach, 1347 .pru_disconnect = uipc_disconnect, 1348 .pru_listen = uipc_listen, 1349 .pru_peeraddr = uipc_peeraddr, 1350 .pru_rcvd = uipc_rcvd, 1351 .pru_send = uipc_send, 1352 .pru_sense = uipc_sense, 1353 .pru_shutdown = uipc_shutdown, 1354 .pru_sockaddr = uipc_sockaddr, 1355 .pru_soreceive = soreceive_dgram, 1356 .pru_close = uipc_close, 1357 }; 1358 1359 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1360 .pru_abort = uipc_abort, 1361 .pru_accept = uipc_accept, 1362 .pru_attach = uipc_attach, 1363 .pru_bind = uipc_bind, 1364 .pru_bindat = uipc_bindat, 1365 .pru_connect = uipc_connect, 1366 .pru_connectat = uipc_connectat, 1367 .pru_connect2 = uipc_connect2, 1368 .pru_detach = uipc_detach, 1369 .pru_disconnect = uipc_disconnect, 1370 .pru_listen = uipc_listen, 1371 .pru_peeraddr = uipc_peeraddr, 1372 .pru_rcvd = uipc_rcvd, 1373 .pru_send = uipc_send, 1374 .pru_sense = uipc_sense, 1375 .pru_shutdown = uipc_shutdown, 1376 .pru_sockaddr = uipc_sockaddr, 1377 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1378 .pru_close = uipc_close, 1379 }; 1380 1381 static struct pr_usrreqs uipc_usrreqs_stream = { 1382 .pru_abort = uipc_abort, 1383 .pru_accept = uipc_accept, 1384 .pru_attach = uipc_attach, 1385 .pru_bind = uipc_bind, 1386 .pru_bindat = uipc_bindat, 1387 .pru_connect = uipc_connect, 1388 .pru_connectat = uipc_connectat, 1389 .pru_connect2 = uipc_connect2, 1390 .pru_detach = uipc_detach, 1391 .pru_disconnect = uipc_disconnect, 1392 .pru_listen = uipc_listen, 1393 .pru_peeraddr = uipc_peeraddr, 1394 .pru_rcvd = uipc_rcvd, 1395 .pru_send = uipc_send, 1396 .pru_ready = uipc_ready, 1397 .pru_sense = uipc_sense, 1398 .pru_shutdown = uipc_shutdown, 1399 .pru_sockaddr = uipc_sockaddr, 1400 .pru_soreceive = soreceive_generic, 1401 .pru_close = uipc_close, 1402 }; 1403 1404 static int 1405 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1406 { 1407 struct unpcb *unp; 1408 struct xucred xu; 1409 int error, optval; 1410 1411 if (sopt->sopt_level != 0) 1412 return (EINVAL); 1413 1414 unp = sotounpcb(so); 1415 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1416 error = 0; 1417 switch (sopt->sopt_dir) { 1418 case SOPT_GET: 1419 switch (sopt->sopt_name) { 1420 case LOCAL_PEERCRED: 1421 UNP_PCB_LOCK(unp); 1422 if (unp->unp_flags & UNP_HAVEPC) 1423 xu = unp->unp_peercred; 1424 else { 1425 if (so->so_type == SOCK_STREAM) 1426 error = ENOTCONN; 1427 else 1428 error = EINVAL; 1429 } 1430 UNP_PCB_UNLOCK(unp); 1431 if (error == 0) 1432 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1433 break; 1434 1435 case LOCAL_CREDS: 1436 /* Unlocked read. */ 1437 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1438 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1439 break; 1440 1441 case LOCAL_CONNWAIT: 1442 /* Unlocked read. */ 1443 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1444 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1445 break; 1446 1447 default: 1448 error = EOPNOTSUPP; 1449 break; 1450 } 1451 break; 1452 1453 case SOPT_SET: 1454 switch (sopt->sopt_name) { 1455 case LOCAL_CREDS: 1456 case LOCAL_CONNWAIT: 1457 error = sooptcopyin(sopt, &optval, sizeof(optval), 1458 sizeof(optval)); 1459 if (error) 1460 break; 1461 1462 #define OPTSET(bit) do { \ 1463 UNP_PCB_LOCK(unp); \ 1464 if (optval) \ 1465 unp->unp_flags |= bit; \ 1466 else \ 1467 unp->unp_flags &= ~bit; \ 1468 UNP_PCB_UNLOCK(unp); \ 1469 } while (0) 1470 1471 switch (sopt->sopt_name) { 1472 case LOCAL_CREDS: 1473 OPTSET(UNP_WANTCRED); 1474 break; 1475 1476 case LOCAL_CONNWAIT: 1477 OPTSET(UNP_CONNWAIT); 1478 break; 1479 1480 default: 1481 break; 1482 } 1483 break; 1484 #undef OPTSET 1485 default: 1486 error = ENOPROTOOPT; 1487 break; 1488 } 1489 break; 1490 1491 default: 1492 error = EOPNOTSUPP; 1493 break; 1494 } 1495 return (error); 1496 } 1497 1498 static int 1499 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1500 { 1501 1502 return (unp_connectat(AT_FDCWD, so, nam, td)); 1503 } 1504 1505 static int 1506 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1507 struct thread *td) 1508 { 1509 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1510 struct vnode *vp; 1511 struct socket *so2; 1512 struct unpcb *unp, *unp2, *unp3; 1513 struct nameidata nd; 1514 char buf[SOCK_MAXADDRLEN]; 1515 struct sockaddr *sa; 1516 cap_rights_t rights; 1517 int error, len, freed; 1518 struct mtx *vplock; 1519 1520 if (nam->sa_family != AF_UNIX) 1521 return (EAFNOSUPPORT); 1522 if (nam->sa_len > sizeof(struct sockaddr_un)) 1523 return (EINVAL); 1524 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1525 if (len <= 0) 1526 return (EINVAL); 1527 bcopy(soun->sun_path, buf, len); 1528 buf[len] = 0; 1529 1530 unp = sotounpcb(so); 1531 UNP_PCB_LOCK(unp); 1532 if (unp->unp_flags & UNP_CONNECTING) { 1533 UNP_PCB_UNLOCK(unp); 1534 return (EALREADY); 1535 } 1536 unp->unp_flags |= UNP_CONNECTING; 1537 UNP_PCB_UNLOCK(unp); 1538 1539 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1540 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1541 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td); 1542 error = namei(&nd); 1543 if (error) 1544 vp = NULL; 1545 else 1546 vp = nd.ni_vp; 1547 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1548 NDFREE(&nd, NDF_ONLY_PNBUF); 1549 if (error) 1550 goto bad; 1551 1552 if (vp->v_type != VSOCK) { 1553 error = ENOTSOCK; 1554 goto bad; 1555 } 1556 #ifdef MAC 1557 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1558 if (error) 1559 goto bad; 1560 #endif 1561 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1562 if (error) 1563 goto bad; 1564 1565 unp = sotounpcb(so); 1566 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1567 1568 vplock = mtx_pool_find(mtxpool_sleep, vp); 1569 mtx_lock(vplock); 1570 VOP_UNP_CONNECT(vp, &unp2); 1571 if (unp2 == NULL) { 1572 error = ECONNREFUSED; 1573 goto bad2; 1574 } 1575 so2 = unp2->unp_socket; 1576 if (so->so_type != so2->so_type) { 1577 error = EPROTOTYPE; 1578 goto bad2; 1579 } 1580 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1581 if (so2->so_options & SO_ACCEPTCONN) { 1582 CURVNET_SET(so2->so_vnet); 1583 so2 = sonewconn(so2, 0); 1584 CURVNET_RESTORE(); 1585 } else 1586 so2 = NULL; 1587 if (so2 == NULL) { 1588 error = ECONNREFUSED; 1589 goto bad2; 1590 } 1591 unp3 = sotounpcb(so2); 1592 unp_pcb_lock2(unp2, unp3); 1593 if (unp2->unp_addr != NULL) { 1594 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1595 unp3->unp_addr = (struct sockaddr_un *) sa; 1596 sa = NULL; 1597 } 1598 1599 unp_copy_peercred(td, unp3, unp, unp2); 1600 1601 UNP_PCB_UNLOCK(unp2); 1602 unp2 = unp3; 1603 unp_pcb_owned_lock2(unp2, unp, freed); 1604 if (__predict_false(freed)) { 1605 UNP_PCB_UNLOCK(unp2); 1606 error = ECONNREFUSED; 1607 goto bad2; 1608 } 1609 #ifdef MAC 1610 mac_socketpeer_set_from_socket(so, so2); 1611 mac_socketpeer_set_from_socket(so2, so); 1612 #endif 1613 } else { 1614 if (unp == unp2) 1615 UNP_PCB_LOCK(unp); 1616 else 1617 unp_pcb_lock2(unp, unp2); 1618 } 1619 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1620 sotounpcb(so2) == unp2, 1621 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1622 error = unp_connect2(so, so2, PRU_CONNECT); 1623 if (unp != unp2) 1624 UNP_PCB_UNLOCK(unp2); 1625 UNP_PCB_UNLOCK(unp); 1626 bad2: 1627 mtx_unlock(vplock); 1628 bad: 1629 if (vp != NULL) { 1630 vput(vp); 1631 } 1632 free(sa, M_SONAME); 1633 UNP_PCB_LOCK(unp); 1634 unp->unp_flags &= ~UNP_CONNECTING; 1635 UNP_PCB_UNLOCK(unp); 1636 return (error); 1637 } 1638 1639 /* 1640 * Set socket peer credentials at connection time. 1641 * 1642 * The client's PCB credentials are copied from its process structure. The 1643 * server's PCB credentials are copied from the socket on which it called 1644 * listen(2). uipc_listen cached that process's credentials at the time. 1645 */ 1646 void 1647 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 1648 struct unpcb *server_unp, struct unpcb *listen_unp) 1649 { 1650 cru2xt(td, &client_unp->unp_peercred); 1651 client_unp->unp_flags |= UNP_HAVEPC; 1652 1653 memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred, 1654 sizeof(server_unp->unp_peercred)); 1655 server_unp->unp_flags |= UNP_HAVEPC; 1656 if (listen_unp->unp_flags & UNP_WANTCRED) 1657 client_unp->unp_flags |= UNP_WANTCRED; 1658 } 1659 1660 static int 1661 unp_connect2(struct socket *so, struct socket *so2, int req) 1662 { 1663 struct unpcb *unp; 1664 struct unpcb *unp2; 1665 1666 unp = sotounpcb(so); 1667 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1668 unp2 = sotounpcb(so2); 1669 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1670 1671 UNP_PCB_LOCK_ASSERT(unp); 1672 UNP_PCB_LOCK_ASSERT(unp2); 1673 1674 if (so2->so_type != so->so_type) 1675 return (EPROTOTYPE); 1676 unp->unp_conn = unp2; 1677 unp_pcb_hold(unp2); 1678 unp_pcb_hold(unp); 1679 switch (so->so_type) { 1680 case SOCK_DGRAM: 1681 UNP_REF_LIST_LOCK(); 1682 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1683 UNP_REF_LIST_UNLOCK(); 1684 soisconnected(so); 1685 break; 1686 1687 case SOCK_STREAM: 1688 case SOCK_SEQPACKET: 1689 unp2->unp_conn = unp; 1690 if (req == PRU_CONNECT && 1691 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1692 soisconnecting(so); 1693 else 1694 soisconnected(so); 1695 soisconnected(so2); 1696 break; 1697 1698 default: 1699 panic("unp_connect2"); 1700 } 1701 return (0); 1702 } 1703 1704 static void 1705 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1706 { 1707 struct socket *so, *so2; 1708 int freed __unused; 1709 1710 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1711 1712 UNP_PCB_LOCK_ASSERT(unp); 1713 UNP_PCB_LOCK_ASSERT(unp2); 1714 1715 if (unp->unp_conn == NULL && unp2->unp_conn == NULL) 1716 return; 1717 1718 MPASS(unp->unp_conn == unp2); 1719 unp->unp_conn = NULL; 1720 so = unp->unp_socket; 1721 so2 = unp2->unp_socket; 1722 switch (unp->unp_socket->so_type) { 1723 case SOCK_DGRAM: 1724 UNP_REF_LIST_LOCK(); 1725 LIST_REMOVE(unp, unp_reflink); 1726 UNP_REF_LIST_UNLOCK(); 1727 if (so) { 1728 SOCK_LOCK(so); 1729 so->so_state &= ~SS_ISCONNECTED; 1730 SOCK_UNLOCK(so); 1731 } 1732 break; 1733 1734 case SOCK_STREAM: 1735 case SOCK_SEQPACKET: 1736 if (so) 1737 soisdisconnected(so); 1738 MPASS(unp2->unp_conn == unp); 1739 unp2->unp_conn = NULL; 1740 if (so2) 1741 soisdisconnected(so2); 1742 break; 1743 } 1744 freed = unp_pcb_rele(unp); 1745 MPASS(freed == 0); 1746 freed = unp_pcb_rele(unp2); 1747 MPASS(freed == 0); 1748 } 1749 1750 /* 1751 * unp_pcblist() walks the global list of struct unpcb's to generate a 1752 * pointer list, bumping the refcount on each unpcb. It then copies them out 1753 * sequentially, validating the generation number on each to see if it has 1754 * been detached. All of this is necessary because copyout() may sleep on 1755 * disk I/O. 1756 */ 1757 static int 1758 unp_pcblist(SYSCTL_HANDLER_ARGS) 1759 { 1760 struct unpcb *unp, **unp_list; 1761 unp_gen_t gencnt; 1762 struct xunpgen *xug; 1763 struct unp_head *head; 1764 struct xunpcb *xu; 1765 u_int i; 1766 int error, freeunp, n; 1767 1768 switch ((intptr_t)arg1) { 1769 case SOCK_STREAM: 1770 head = &unp_shead; 1771 break; 1772 1773 case SOCK_DGRAM: 1774 head = &unp_dhead; 1775 break; 1776 1777 case SOCK_SEQPACKET: 1778 head = &unp_sphead; 1779 break; 1780 1781 default: 1782 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1783 } 1784 1785 /* 1786 * The process of preparing the PCB list is too time-consuming and 1787 * resource-intensive to repeat twice on every request. 1788 */ 1789 if (req->oldptr == NULL) { 1790 n = unp_count; 1791 req->oldidx = 2 * (sizeof *xug) 1792 + (n + n/8) * sizeof(struct xunpcb); 1793 return (0); 1794 } 1795 1796 if (req->newptr != NULL) 1797 return (EPERM); 1798 1799 /* 1800 * OK, now we're committed to doing something. 1801 */ 1802 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK | M_ZERO); 1803 UNP_LINK_RLOCK(); 1804 gencnt = unp_gencnt; 1805 n = unp_count; 1806 UNP_LINK_RUNLOCK(); 1807 1808 xug->xug_len = sizeof *xug; 1809 xug->xug_count = n; 1810 xug->xug_gen = gencnt; 1811 xug->xug_sogen = so_gencnt; 1812 error = SYSCTL_OUT(req, xug, sizeof *xug); 1813 if (error) { 1814 free(xug, M_TEMP); 1815 return (error); 1816 } 1817 1818 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1819 1820 UNP_LINK_RLOCK(); 1821 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1822 unp = LIST_NEXT(unp, unp_link)) { 1823 UNP_PCB_LOCK(unp); 1824 if (unp->unp_gencnt <= gencnt) { 1825 if (cr_cansee(req->td->td_ucred, 1826 unp->unp_socket->so_cred)) { 1827 UNP_PCB_UNLOCK(unp); 1828 continue; 1829 } 1830 unp_list[i++] = unp; 1831 unp_pcb_hold(unp); 1832 } 1833 UNP_PCB_UNLOCK(unp); 1834 } 1835 UNP_LINK_RUNLOCK(); 1836 n = i; /* In case we lost some during malloc. */ 1837 1838 error = 0; 1839 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1840 for (i = 0; i < n; i++) { 1841 unp = unp_list[i]; 1842 UNP_PCB_LOCK(unp); 1843 freeunp = unp_pcb_rele(unp); 1844 1845 if (freeunp == 0 && unp->unp_gencnt <= gencnt) { 1846 xu->xu_len = sizeof *xu; 1847 xu->xu_unpp = (uintptr_t)unp; 1848 /* 1849 * XXX - need more locking here to protect against 1850 * connect/disconnect races for SMP. 1851 */ 1852 if (unp->unp_addr != NULL) 1853 bcopy(unp->unp_addr, &xu->xu_addr, 1854 unp->unp_addr->sun_len); 1855 else 1856 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1857 if (unp->unp_conn != NULL && 1858 unp->unp_conn->unp_addr != NULL) 1859 bcopy(unp->unp_conn->unp_addr, 1860 &xu->xu_caddr, 1861 unp->unp_conn->unp_addr->sun_len); 1862 else 1863 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1864 xu->unp_vnode = (uintptr_t)unp->unp_vnode; 1865 xu->unp_conn = (uintptr_t)unp->unp_conn; 1866 xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs); 1867 xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink); 1868 xu->unp_gencnt = unp->unp_gencnt; 1869 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1870 UNP_PCB_UNLOCK(unp); 1871 error = SYSCTL_OUT(req, xu, sizeof *xu); 1872 } else if (freeunp == 0) 1873 UNP_PCB_UNLOCK(unp); 1874 } 1875 free(xu, M_TEMP); 1876 if (!error) { 1877 /* 1878 * Give the user an updated idea of our state. If the 1879 * generation differs from what we told her before, she knows 1880 * that something happened while we were processing this 1881 * request, and it might be necessary to retry. 1882 */ 1883 xug->xug_gen = unp_gencnt; 1884 xug->xug_sogen = so_gencnt; 1885 xug->xug_count = unp_count; 1886 error = SYSCTL_OUT(req, xug, sizeof *xug); 1887 } 1888 free(unp_list, M_TEMP); 1889 free(xug, M_TEMP); 1890 return (error); 1891 } 1892 1893 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, 1894 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1895 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1896 "List of active local datagram sockets"); 1897 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, 1898 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1899 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1900 "List of active local stream sockets"); 1901 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1902 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, 1903 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1904 "List of active local seqpacket sockets"); 1905 1906 static void 1907 unp_shutdown(struct unpcb *unp) 1908 { 1909 struct unpcb *unp2; 1910 struct socket *so; 1911 1912 UNP_PCB_LOCK_ASSERT(unp); 1913 1914 unp2 = unp->unp_conn; 1915 if ((unp->unp_socket->so_type == SOCK_STREAM || 1916 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1917 so = unp2->unp_socket; 1918 if (so != NULL) 1919 socantrcvmore(so); 1920 } 1921 } 1922 1923 static void 1924 unp_drop(struct unpcb *unp) 1925 { 1926 struct socket *so = unp->unp_socket; 1927 struct unpcb *unp2; 1928 int freed; 1929 1930 /* 1931 * Regardless of whether the socket's peer dropped the connection 1932 * with this socket by aborting or disconnecting, POSIX requires 1933 * that ECONNRESET is returned. 1934 */ 1935 /* acquire a reference so that unp isn't freed from underneath us */ 1936 1937 UNP_PCB_LOCK(unp); 1938 if (so) 1939 so->so_error = ECONNRESET; 1940 unp2 = unp->unp_conn; 1941 if (unp2 == unp) { 1942 unp_disconnect(unp, unp2); 1943 } else if (unp2 != NULL) { 1944 unp_pcb_hold(unp2); 1945 unp_pcb_owned_lock2(unp, unp2, freed); 1946 unp_disconnect(unp, unp2); 1947 if (unp_pcb_rele(unp2) == 0) 1948 UNP_PCB_UNLOCK(unp2); 1949 } 1950 if (unp_pcb_rele(unp) == 0) 1951 UNP_PCB_UNLOCK(unp); 1952 } 1953 1954 static void 1955 unp_freerights(struct filedescent **fdep, int fdcount) 1956 { 1957 struct file *fp; 1958 int i; 1959 1960 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1961 1962 for (i = 0; i < fdcount; i++) { 1963 fp = fdep[i]->fde_file; 1964 filecaps_free(&fdep[i]->fde_caps); 1965 unp_discard(fp); 1966 } 1967 free(fdep[0], M_FILECAPS); 1968 } 1969 1970 static int 1971 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 1972 { 1973 struct thread *td = curthread; /* XXX */ 1974 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1975 int i; 1976 int *fdp; 1977 struct filedesc *fdesc = td->td_proc->p_fd; 1978 struct filedescent **fdep; 1979 void *data; 1980 socklen_t clen = control->m_len, datalen; 1981 int error, newfds; 1982 u_int newlen; 1983 1984 UNP_LINK_UNLOCK_ASSERT(); 1985 1986 error = 0; 1987 if (controlp != NULL) /* controlp == NULL => free control messages */ 1988 *controlp = NULL; 1989 while (cm != NULL) { 1990 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1991 error = EINVAL; 1992 break; 1993 } 1994 data = CMSG_DATA(cm); 1995 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1996 if (cm->cmsg_level == SOL_SOCKET 1997 && cm->cmsg_type == SCM_RIGHTS) { 1998 newfds = datalen / sizeof(*fdep); 1999 if (newfds == 0) 2000 goto next; 2001 fdep = data; 2002 2003 /* If we're not outputting the descriptors free them. */ 2004 if (error || controlp == NULL) { 2005 unp_freerights(fdep, newfds); 2006 goto next; 2007 } 2008 FILEDESC_XLOCK(fdesc); 2009 2010 /* 2011 * Now change each pointer to an fd in the global 2012 * table to an integer that is the index to the local 2013 * fd table entry that we set up to point to the 2014 * global one we are transferring. 2015 */ 2016 newlen = newfds * sizeof(int); 2017 *controlp = sbcreatecontrol(NULL, newlen, 2018 SCM_RIGHTS, SOL_SOCKET); 2019 if (*controlp == NULL) { 2020 FILEDESC_XUNLOCK(fdesc); 2021 error = E2BIG; 2022 unp_freerights(fdep, newfds); 2023 goto next; 2024 } 2025 2026 fdp = (int *) 2027 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2028 if (fdallocn(td, 0, fdp, newfds) != 0) { 2029 FILEDESC_XUNLOCK(fdesc); 2030 error = EMSGSIZE; 2031 unp_freerights(fdep, newfds); 2032 m_freem(*controlp); 2033 *controlp = NULL; 2034 goto next; 2035 } 2036 for (i = 0; i < newfds; i++, fdp++) { 2037 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2038 (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0, 2039 &fdep[i]->fde_caps); 2040 unp_externalize_fp(fdep[i]->fde_file); 2041 } 2042 2043 /* 2044 * The new type indicates that the mbuf data refers to 2045 * kernel resources that may need to be released before 2046 * the mbuf is freed. 2047 */ 2048 m_chtype(*controlp, MT_EXTCONTROL); 2049 FILEDESC_XUNLOCK(fdesc); 2050 free(fdep[0], M_FILECAPS); 2051 } else { 2052 /* We can just copy anything else across. */ 2053 if (error || controlp == NULL) 2054 goto next; 2055 *controlp = sbcreatecontrol(NULL, datalen, 2056 cm->cmsg_type, cm->cmsg_level); 2057 if (*controlp == NULL) { 2058 error = ENOBUFS; 2059 goto next; 2060 } 2061 bcopy(data, 2062 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2063 datalen); 2064 } 2065 controlp = &(*controlp)->m_next; 2066 2067 next: 2068 if (CMSG_SPACE(datalen) < clen) { 2069 clen -= CMSG_SPACE(datalen); 2070 cm = (struct cmsghdr *) 2071 ((caddr_t)cm + CMSG_SPACE(datalen)); 2072 } else { 2073 clen = 0; 2074 cm = NULL; 2075 } 2076 } 2077 2078 m_freem(control); 2079 return (error); 2080 } 2081 2082 static void 2083 unp_zone_change(void *tag) 2084 { 2085 2086 uma_zone_set_max(unp_zone, maxsockets); 2087 } 2088 2089 static void 2090 unp_init(void) 2091 { 2092 2093 #ifdef VIMAGE 2094 if (!IS_DEFAULT_VNET(curvnet)) 2095 return; 2096 #endif 2097 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 2098 NULL, NULL, UMA_ALIGN_CACHE, 0); 2099 if (unp_zone == NULL) 2100 panic("unp_init"); 2101 uma_zone_set_max(unp_zone, maxsockets); 2102 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2103 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2104 NULL, EVENTHANDLER_PRI_ANY); 2105 LIST_INIT(&unp_dhead); 2106 LIST_INIT(&unp_shead); 2107 LIST_INIT(&unp_sphead); 2108 SLIST_INIT(&unp_defers); 2109 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2110 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2111 UNP_LINK_LOCK_INIT(); 2112 UNP_DEFERRED_LOCK_INIT(); 2113 } 2114 2115 static void 2116 unp_internalize_cleanup_rights(struct mbuf *control) 2117 { 2118 struct cmsghdr *cp; 2119 struct mbuf *m; 2120 void *data; 2121 socklen_t datalen; 2122 2123 for (m = control; m != NULL; m = m->m_next) { 2124 cp = mtod(m, struct cmsghdr *); 2125 if (cp->cmsg_level != SOL_SOCKET || 2126 cp->cmsg_type != SCM_RIGHTS) 2127 continue; 2128 data = CMSG_DATA(cp); 2129 datalen = (caddr_t)cp + cp->cmsg_len - (caddr_t)data; 2130 unp_freerights(data, datalen / sizeof(struct filedesc *)); 2131 } 2132 } 2133 2134 static int 2135 unp_internalize(struct mbuf **controlp, struct thread *td) 2136 { 2137 struct mbuf *control, **initial_controlp; 2138 struct proc *p; 2139 struct filedesc *fdesc; 2140 struct bintime *bt; 2141 struct cmsghdr *cm; 2142 struct cmsgcred *cmcred; 2143 struct filedescent *fde, **fdep, *fdev; 2144 struct file *fp; 2145 struct timeval *tv; 2146 struct timespec *ts; 2147 void *data; 2148 socklen_t clen, datalen; 2149 int i, j, error, *fdp, oldfds; 2150 u_int newlen; 2151 2152 UNP_LINK_UNLOCK_ASSERT(); 2153 2154 p = td->td_proc; 2155 fdesc = p->p_fd; 2156 error = 0; 2157 control = *controlp; 2158 clen = control->m_len; 2159 *controlp = NULL; 2160 initial_controlp = controlp; 2161 for (cm = mtod(control, struct cmsghdr *); cm != NULL;) { 2162 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2163 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2164 error = EINVAL; 2165 goto out; 2166 } 2167 data = CMSG_DATA(cm); 2168 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2169 2170 switch (cm->cmsg_type) { 2171 /* 2172 * Fill in credential information. 2173 */ 2174 case SCM_CREDS: 2175 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2176 SCM_CREDS, SOL_SOCKET); 2177 if (*controlp == NULL) { 2178 error = ENOBUFS; 2179 goto out; 2180 } 2181 cmcred = (struct cmsgcred *) 2182 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2183 cmcred->cmcred_pid = p->p_pid; 2184 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2185 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2186 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2187 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2188 CMGROUP_MAX); 2189 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2190 cmcred->cmcred_groups[i] = 2191 td->td_ucred->cr_groups[i]; 2192 break; 2193 2194 case SCM_RIGHTS: 2195 oldfds = datalen / sizeof (int); 2196 if (oldfds == 0) 2197 break; 2198 /* 2199 * Check that all the FDs passed in refer to legal 2200 * files. If not, reject the entire operation. 2201 */ 2202 fdp = data; 2203 FILEDESC_SLOCK(fdesc); 2204 for (i = 0; i < oldfds; i++, fdp++) { 2205 fp = fget_locked(fdesc, *fdp); 2206 if (fp == NULL) { 2207 FILEDESC_SUNLOCK(fdesc); 2208 error = EBADF; 2209 goto out; 2210 } 2211 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2212 FILEDESC_SUNLOCK(fdesc); 2213 error = EOPNOTSUPP; 2214 goto out; 2215 } 2216 2217 } 2218 2219 /* 2220 * Now replace the integer FDs with pointers to the 2221 * file structure and capability rights. 2222 */ 2223 newlen = oldfds * sizeof(fdep[0]); 2224 *controlp = sbcreatecontrol(NULL, newlen, 2225 SCM_RIGHTS, SOL_SOCKET); 2226 if (*controlp == NULL) { 2227 FILEDESC_SUNLOCK(fdesc); 2228 error = E2BIG; 2229 goto out; 2230 } 2231 fdp = data; 2232 for (i = 0; i < oldfds; i++, fdp++) { 2233 if (!fhold(fdesc->fd_ofiles[*fdp].fde_file)) { 2234 fdp = data; 2235 for (j = 0; j < i; j++, fdp++) { 2236 fdrop(fdesc->fd_ofiles[*fdp]. 2237 fde_file, td); 2238 } 2239 FILEDESC_SUNLOCK(fdesc); 2240 error = EBADF; 2241 goto out; 2242 } 2243 } 2244 fdp = data; 2245 fdep = (struct filedescent **) 2246 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2247 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2248 M_WAITOK); 2249 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2250 fde = &fdesc->fd_ofiles[*fdp]; 2251 fdep[i] = fdev; 2252 fdep[i]->fde_file = fde->fde_file; 2253 filecaps_copy(&fde->fde_caps, 2254 &fdep[i]->fde_caps, true); 2255 unp_internalize_fp(fdep[i]->fde_file); 2256 } 2257 FILEDESC_SUNLOCK(fdesc); 2258 break; 2259 2260 case SCM_TIMESTAMP: 2261 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2262 SCM_TIMESTAMP, SOL_SOCKET); 2263 if (*controlp == NULL) { 2264 error = ENOBUFS; 2265 goto out; 2266 } 2267 tv = (struct timeval *) 2268 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2269 microtime(tv); 2270 break; 2271 2272 case SCM_BINTIME: 2273 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2274 SCM_BINTIME, SOL_SOCKET); 2275 if (*controlp == NULL) { 2276 error = ENOBUFS; 2277 goto out; 2278 } 2279 bt = (struct bintime *) 2280 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2281 bintime(bt); 2282 break; 2283 2284 case SCM_REALTIME: 2285 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2286 SCM_REALTIME, SOL_SOCKET); 2287 if (*controlp == NULL) { 2288 error = ENOBUFS; 2289 goto out; 2290 } 2291 ts = (struct timespec *) 2292 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2293 nanotime(ts); 2294 break; 2295 2296 case SCM_MONOTONIC: 2297 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2298 SCM_MONOTONIC, SOL_SOCKET); 2299 if (*controlp == NULL) { 2300 error = ENOBUFS; 2301 goto out; 2302 } 2303 ts = (struct timespec *) 2304 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2305 nanouptime(ts); 2306 break; 2307 2308 default: 2309 error = EINVAL; 2310 goto out; 2311 } 2312 2313 if (*controlp != NULL) 2314 controlp = &(*controlp)->m_next; 2315 if (CMSG_SPACE(datalen) < clen) { 2316 clen -= CMSG_SPACE(datalen); 2317 cm = (struct cmsghdr *) 2318 ((caddr_t)cm + CMSG_SPACE(datalen)); 2319 } else { 2320 clen = 0; 2321 cm = NULL; 2322 } 2323 } 2324 2325 out: 2326 if (error != 0 && initial_controlp != NULL) 2327 unp_internalize_cleanup_rights(*initial_controlp); 2328 m_freem(control); 2329 return (error); 2330 } 2331 2332 static struct mbuf * 2333 unp_addsockcred(struct thread *td, struct mbuf *control) 2334 { 2335 struct mbuf *m, *n, *n_prev; 2336 struct sockcred *sc; 2337 const struct cmsghdr *cm; 2338 int ngroups; 2339 int i; 2340 2341 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2342 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 2343 if (m == NULL) 2344 return (control); 2345 2346 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 2347 sc->sc_uid = td->td_ucred->cr_ruid; 2348 sc->sc_euid = td->td_ucred->cr_uid; 2349 sc->sc_gid = td->td_ucred->cr_rgid; 2350 sc->sc_egid = td->td_ucred->cr_gid; 2351 sc->sc_ngroups = ngroups; 2352 for (i = 0; i < sc->sc_ngroups; i++) 2353 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2354 2355 /* 2356 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2357 * created SCM_CREDS control message (struct sockcred) has another 2358 * format. 2359 */ 2360 if (control != NULL) 2361 for (n = control, n_prev = NULL; n != NULL;) { 2362 cm = mtod(n, struct cmsghdr *); 2363 if (cm->cmsg_level == SOL_SOCKET && 2364 cm->cmsg_type == SCM_CREDS) { 2365 if (n_prev == NULL) 2366 control = n->m_next; 2367 else 2368 n_prev->m_next = n->m_next; 2369 n = m_free(n); 2370 } else { 2371 n_prev = n; 2372 n = n->m_next; 2373 } 2374 } 2375 2376 /* Prepend it to the head. */ 2377 m->m_next = control; 2378 return (m); 2379 } 2380 2381 static struct unpcb * 2382 fptounp(struct file *fp) 2383 { 2384 struct socket *so; 2385 2386 if (fp->f_type != DTYPE_SOCKET) 2387 return (NULL); 2388 if ((so = fp->f_data) == NULL) 2389 return (NULL); 2390 if (so->so_proto->pr_domain != &localdomain) 2391 return (NULL); 2392 return sotounpcb(so); 2393 } 2394 2395 static void 2396 unp_discard(struct file *fp) 2397 { 2398 struct unp_defer *dr; 2399 2400 if (unp_externalize_fp(fp)) { 2401 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2402 dr->ud_fp = fp; 2403 UNP_DEFERRED_LOCK(); 2404 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2405 UNP_DEFERRED_UNLOCK(); 2406 atomic_add_int(&unp_defers_count, 1); 2407 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2408 } else 2409 (void) closef(fp, (struct thread *)NULL); 2410 } 2411 2412 static void 2413 unp_process_defers(void *arg __unused, int pending) 2414 { 2415 struct unp_defer *dr; 2416 SLIST_HEAD(, unp_defer) drl; 2417 int count; 2418 2419 SLIST_INIT(&drl); 2420 for (;;) { 2421 UNP_DEFERRED_LOCK(); 2422 if (SLIST_FIRST(&unp_defers) == NULL) { 2423 UNP_DEFERRED_UNLOCK(); 2424 break; 2425 } 2426 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2427 UNP_DEFERRED_UNLOCK(); 2428 count = 0; 2429 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2430 SLIST_REMOVE_HEAD(&drl, ud_link); 2431 closef(dr->ud_fp, NULL); 2432 free(dr, M_TEMP); 2433 count++; 2434 } 2435 atomic_add_int(&unp_defers_count, -count); 2436 } 2437 } 2438 2439 static void 2440 unp_internalize_fp(struct file *fp) 2441 { 2442 struct unpcb *unp; 2443 2444 UNP_LINK_WLOCK(); 2445 if ((unp = fptounp(fp)) != NULL) { 2446 unp->unp_file = fp; 2447 unp->unp_msgcount++; 2448 } 2449 unp_rights++; 2450 UNP_LINK_WUNLOCK(); 2451 } 2452 2453 static int 2454 unp_externalize_fp(struct file *fp) 2455 { 2456 struct unpcb *unp; 2457 int ret; 2458 2459 UNP_LINK_WLOCK(); 2460 if ((unp = fptounp(fp)) != NULL) { 2461 unp->unp_msgcount--; 2462 ret = 1; 2463 } else 2464 ret = 0; 2465 unp_rights--; 2466 UNP_LINK_WUNLOCK(); 2467 return (ret); 2468 } 2469 2470 /* 2471 * unp_defer indicates whether additional work has been defered for a future 2472 * pass through unp_gc(). It is thread local and does not require explicit 2473 * synchronization. 2474 */ 2475 static int unp_marked; 2476 2477 static void 2478 unp_remove_dead_ref(struct filedescent **fdep, int fdcount) 2479 { 2480 struct unpcb *unp; 2481 struct file *fp; 2482 int i; 2483 2484 /* 2485 * This function can only be called from the gc task. 2486 */ 2487 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2488 ("%s: not on gc callout", __func__)); 2489 UNP_LINK_LOCK_ASSERT(); 2490 2491 for (i = 0; i < fdcount; i++) { 2492 fp = fdep[i]->fde_file; 2493 if ((unp = fptounp(fp)) == NULL) 2494 continue; 2495 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2496 continue; 2497 unp->unp_gcrefs--; 2498 } 2499 } 2500 2501 static void 2502 unp_restore_undead_ref(struct filedescent **fdep, int fdcount) 2503 { 2504 struct unpcb *unp; 2505 struct file *fp; 2506 int i; 2507 2508 /* 2509 * This function can only be called from the gc task. 2510 */ 2511 KASSERT(taskqueue_member(taskqueue_thread, curthread) != 0, 2512 ("%s: not on gc callout", __func__)); 2513 UNP_LINK_LOCK_ASSERT(); 2514 2515 for (i = 0; i < fdcount; i++) { 2516 fp = fdep[i]->fde_file; 2517 if ((unp = fptounp(fp)) == NULL) 2518 continue; 2519 if ((unp->unp_gcflag & UNPGC_DEAD) == 0) 2520 continue; 2521 unp->unp_gcrefs++; 2522 unp_marked++; 2523 } 2524 } 2525 2526 static void 2527 unp_gc_scan(struct unpcb *unp, void (*op)(struct filedescent **, int)) 2528 { 2529 struct socket *so, *soa; 2530 2531 so = unp->unp_socket; 2532 SOCK_LOCK(so); 2533 if (SOLISTENING(so)) { 2534 /* 2535 * Mark all sockets in our accept queue. 2536 */ 2537 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2538 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2539 continue; 2540 SOCKBUF_LOCK(&soa->so_rcv); 2541 unp_scan(soa->so_rcv.sb_mb, op); 2542 SOCKBUF_UNLOCK(&soa->so_rcv); 2543 } 2544 } else { 2545 /* 2546 * Mark all sockets we reference with RIGHTS. 2547 */ 2548 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2549 SOCKBUF_LOCK(&so->so_rcv); 2550 unp_scan(so->so_rcv.sb_mb, op); 2551 SOCKBUF_UNLOCK(&so->so_rcv); 2552 } 2553 } 2554 SOCK_UNLOCK(so); 2555 } 2556 2557 static int unp_recycled; 2558 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2559 "Number of unreachable sockets claimed by the garbage collector."); 2560 2561 static int unp_taskcount; 2562 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2563 "Number of times the garbage collector has run."); 2564 2565 SYSCTL_UINT(_net_local, OID_AUTO, sockcount, CTLFLAG_RD, &unp_count, 0, 2566 "Number of active local sockets."); 2567 2568 static void 2569 unp_gc(__unused void *arg, int pending) 2570 { 2571 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2572 NULL }; 2573 struct unp_head **head; 2574 struct unp_head unp_deadhead; /* List of potentially-dead sockets. */ 2575 struct file *f, **unref; 2576 struct unpcb *unp, *unptmp; 2577 int i, total, unp_unreachable; 2578 2579 LIST_INIT(&unp_deadhead); 2580 unp_taskcount++; 2581 UNP_LINK_RLOCK(); 2582 /* 2583 * First determine which sockets may be in cycles. 2584 */ 2585 unp_unreachable = 0; 2586 2587 for (head = heads; *head != NULL; head++) 2588 LIST_FOREACH(unp, *head, unp_link) { 2589 2590 KASSERT((unp->unp_gcflag & ~UNPGC_IGNORE_RIGHTS) == 0, 2591 ("%s: unp %p has unexpected gc flags 0x%x", 2592 __func__, unp, (unsigned int)unp->unp_gcflag)); 2593 2594 f = unp->unp_file; 2595 2596 /* 2597 * Check for an unreachable socket potentially in a 2598 * cycle. It must be in a queue as indicated by 2599 * msgcount, and this must equal the file reference 2600 * count. Note that when msgcount is 0 the file is 2601 * NULL. 2602 */ 2603 if (f != NULL && unp->unp_msgcount != 0 && 2604 f->f_count == unp->unp_msgcount) { 2605 LIST_INSERT_HEAD(&unp_deadhead, unp, unp_dead); 2606 unp->unp_gcflag |= UNPGC_DEAD; 2607 unp->unp_gcrefs = unp->unp_msgcount; 2608 unp_unreachable++; 2609 } 2610 } 2611 2612 /* 2613 * Scan all sockets previously marked as potentially being in a cycle 2614 * and remove the references each socket holds on any UNPGC_DEAD 2615 * sockets in its queue. After this step, all remaining references on 2616 * sockets marked UNPGC_DEAD should not be part of any cycle. 2617 */ 2618 LIST_FOREACH(unp, &unp_deadhead, unp_dead) 2619 unp_gc_scan(unp, unp_remove_dead_ref); 2620 2621 /* 2622 * If a socket still has a non-negative refcount, it cannot be in a 2623 * cycle. In this case increment refcount of all children iteratively. 2624 * Stop the scan once we do a complete loop without discovering 2625 * a new reachable socket. 2626 */ 2627 do { 2628 unp_marked = 0; 2629 LIST_FOREACH_SAFE(unp, &unp_deadhead, unp_dead, unptmp) 2630 if (unp->unp_gcrefs > 0) { 2631 unp->unp_gcflag &= ~UNPGC_DEAD; 2632 LIST_REMOVE(unp, unp_dead); 2633 KASSERT(unp_unreachable > 0, 2634 ("%s: unp_unreachable underflow.", 2635 __func__)); 2636 unp_unreachable--; 2637 unp_gc_scan(unp, unp_restore_undead_ref); 2638 } 2639 } while (unp_marked); 2640 2641 UNP_LINK_RUNLOCK(); 2642 2643 if (unp_unreachable == 0) 2644 return; 2645 2646 /* 2647 * Allocate space for a local array of dead unpcbs. 2648 * TODO: can this path be simplified by instead using the local 2649 * dead list at unp_deadhead, after taking out references 2650 * on the file object and/or unpcb and dropping the link lock? 2651 */ 2652 unref = malloc(unp_unreachable * sizeof(struct file *), 2653 M_TEMP, M_WAITOK); 2654 2655 /* 2656 * Iterate looking for sockets which have been specifically marked 2657 * as unreachable and store them locally. 2658 */ 2659 UNP_LINK_RLOCK(); 2660 total = 0; 2661 LIST_FOREACH(unp, &unp_deadhead, unp_dead) { 2662 KASSERT((unp->unp_gcflag & UNPGC_DEAD) != 0, 2663 ("%s: unp %p not marked UNPGC_DEAD", __func__, unp)); 2664 unp->unp_gcflag &= ~UNPGC_DEAD; 2665 f = unp->unp_file; 2666 if (unp->unp_msgcount == 0 || f == NULL || 2667 f->f_count != unp->unp_msgcount || 2668 !fhold(f)) 2669 continue; 2670 unref[total++] = f; 2671 KASSERT(total <= unp_unreachable, 2672 ("%s: incorrect unreachable count.", __func__)); 2673 } 2674 UNP_LINK_RUNLOCK(); 2675 2676 /* 2677 * Now flush all sockets, free'ing rights. This will free the 2678 * struct files associated with these sockets but leave each socket 2679 * with one remaining ref. 2680 */ 2681 for (i = 0; i < total; i++) { 2682 struct socket *so; 2683 2684 so = unref[i]->f_data; 2685 CURVNET_SET(so->so_vnet); 2686 sorflush(so); 2687 CURVNET_RESTORE(); 2688 } 2689 2690 /* 2691 * And finally release the sockets so they can be reclaimed. 2692 */ 2693 for (i = 0; i < total; i++) 2694 fdrop(unref[i], NULL); 2695 unp_recycled += total; 2696 free(unref, M_TEMP); 2697 } 2698 2699 static void 2700 unp_dispose_mbuf(struct mbuf *m) 2701 { 2702 2703 if (m) 2704 unp_scan(m, unp_freerights); 2705 } 2706 2707 /* 2708 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2709 */ 2710 static void 2711 unp_dispose(struct socket *so) 2712 { 2713 struct unpcb *unp; 2714 2715 unp = sotounpcb(so); 2716 UNP_LINK_WLOCK(); 2717 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2718 UNP_LINK_WUNLOCK(); 2719 if (!SOLISTENING(so)) 2720 unp_dispose_mbuf(so->so_rcv.sb_mb); 2721 } 2722 2723 static void 2724 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2725 { 2726 struct mbuf *m; 2727 struct cmsghdr *cm; 2728 void *data; 2729 socklen_t clen, datalen; 2730 2731 while (m0 != NULL) { 2732 for (m = m0; m; m = m->m_next) { 2733 if (m->m_type != MT_CONTROL) 2734 continue; 2735 2736 cm = mtod(m, struct cmsghdr *); 2737 clen = m->m_len; 2738 2739 while (cm != NULL) { 2740 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2741 break; 2742 2743 data = CMSG_DATA(cm); 2744 datalen = (caddr_t)cm + cm->cmsg_len 2745 - (caddr_t)data; 2746 2747 if (cm->cmsg_level == SOL_SOCKET && 2748 cm->cmsg_type == SCM_RIGHTS) { 2749 (*op)(data, datalen / 2750 sizeof(struct filedescent *)); 2751 } 2752 2753 if (CMSG_SPACE(datalen) < clen) { 2754 clen -= CMSG_SPACE(datalen); 2755 cm = (struct cmsghdr *) 2756 ((caddr_t)cm + CMSG_SPACE(datalen)); 2757 } else { 2758 clen = 0; 2759 cm = NULL; 2760 } 2761 } 2762 } 2763 m0 = m0->m_nextpkt; 2764 } 2765 } 2766 2767 /* 2768 * A helper function called by VFS before socket-type vnode reclamation. 2769 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2770 * use count. 2771 */ 2772 void 2773 vfs_unp_reclaim(struct vnode *vp) 2774 { 2775 struct unpcb *unp; 2776 int active; 2777 struct mtx *vplock; 2778 2779 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2780 KASSERT(vp->v_type == VSOCK, 2781 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2782 2783 active = 0; 2784 vplock = mtx_pool_find(mtxpool_sleep, vp); 2785 mtx_lock(vplock); 2786 VOP_UNP_CONNECT(vp, &unp); 2787 if (unp == NULL) 2788 goto done; 2789 UNP_PCB_LOCK(unp); 2790 if (unp->unp_vnode == vp) { 2791 VOP_UNP_DETACH(vp); 2792 unp->unp_vnode = NULL; 2793 active = 1; 2794 } 2795 UNP_PCB_UNLOCK(unp); 2796 done: 2797 mtx_unlock(vplock); 2798 if (active) 2799 vunref(vp); 2800 } 2801 2802 #ifdef DDB 2803 static void 2804 db_print_indent(int indent) 2805 { 2806 int i; 2807 2808 for (i = 0; i < indent; i++) 2809 db_printf(" "); 2810 } 2811 2812 static void 2813 db_print_unpflags(int unp_flags) 2814 { 2815 int comma; 2816 2817 comma = 0; 2818 if (unp_flags & UNP_HAVEPC) { 2819 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2820 comma = 1; 2821 } 2822 if (unp_flags & UNP_WANTCRED) { 2823 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2824 comma = 1; 2825 } 2826 if (unp_flags & UNP_CONNWAIT) { 2827 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2828 comma = 1; 2829 } 2830 if (unp_flags & UNP_CONNECTING) { 2831 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2832 comma = 1; 2833 } 2834 if (unp_flags & UNP_BINDING) { 2835 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2836 comma = 1; 2837 } 2838 } 2839 2840 static void 2841 db_print_xucred(int indent, struct xucred *xu) 2842 { 2843 int comma, i; 2844 2845 db_print_indent(indent); 2846 db_printf("cr_version: %u cr_uid: %u cr_pid: %d cr_ngroups: %d\n", 2847 xu->cr_version, xu->cr_uid, xu->cr_pid, xu->cr_ngroups); 2848 db_print_indent(indent); 2849 db_printf("cr_groups: "); 2850 comma = 0; 2851 for (i = 0; i < xu->cr_ngroups; i++) { 2852 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2853 comma = 1; 2854 } 2855 db_printf("\n"); 2856 } 2857 2858 static void 2859 db_print_unprefs(int indent, struct unp_head *uh) 2860 { 2861 struct unpcb *unp; 2862 int counter; 2863 2864 counter = 0; 2865 LIST_FOREACH(unp, uh, unp_reflink) { 2866 if (counter % 4 == 0) 2867 db_print_indent(indent); 2868 db_printf("%p ", unp); 2869 if (counter % 4 == 3) 2870 db_printf("\n"); 2871 counter++; 2872 } 2873 if (counter != 0 && counter % 4 != 0) 2874 db_printf("\n"); 2875 } 2876 2877 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2878 { 2879 struct unpcb *unp; 2880 2881 if (!have_addr) { 2882 db_printf("usage: show unpcb <addr>\n"); 2883 return; 2884 } 2885 unp = (struct unpcb *)addr; 2886 2887 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2888 unp->unp_vnode); 2889 2890 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2891 unp->unp_conn); 2892 2893 db_printf("unp_refs:\n"); 2894 db_print_unprefs(2, &unp->unp_refs); 2895 2896 /* XXXRW: Would be nice to print the full address, if any. */ 2897 db_printf("unp_addr: %p\n", unp->unp_addr); 2898 2899 db_printf("unp_gencnt: %llu\n", 2900 (unsigned long long)unp->unp_gencnt); 2901 2902 db_printf("unp_flags: %x (", unp->unp_flags); 2903 db_print_unpflags(unp->unp_flags); 2904 db_printf(")\n"); 2905 2906 db_printf("unp_peercred:\n"); 2907 db_print_xucred(2, &unp->unp_peercred); 2908 2909 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2910 } 2911 #endif 2912