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