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, int *freed) 361 362 { 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 } \ 387 } while (0) 388 389 390 /* 391 * Definitions of protocols supported in the LOCAL domain. 392 */ 393 static struct domain localdomain; 394 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 395 static struct pr_usrreqs uipc_usrreqs_seqpacket; 396 static struct protosw localsw[] = { 397 { 398 .pr_type = SOCK_STREAM, 399 .pr_domain = &localdomain, 400 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 401 .pr_ctloutput = &uipc_ctloutput, 402 .pr_usrreqs = &uipc_usrreqs_stream 403 }, 404 { 405 .pr_type = SOCK_DGRAM, 406 .pr_domain = &localdomain, 407 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 408 .pr_ctloutput = &uipc_ctloutput, 409 .pr_usrreqs = &uipc_usrreqs_dgram 410 }, 411 { 412 .pr_type = SOCK_SEQPACKET, 413 .pr_domain = &localdomain, 414 415 /* 416 * XXXRW: For now, PR_ADDR because soreceive will bump into them 417 * due to our use of sbappendaddr. A new sbappend variants is needed 418 * that supports both atomic record writes and control data. 419 */ 420 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD| 421 PR_RIGHTS, 422 .pr_ctloutput = &uipc_ctloutput, 423 .pr_usrreqs = &uipc_usrreqs_seqpacket, 424 }, 425 }; 426 427 static struct domain localdomain = { 428 .dom_family = AF_LOCAL, 429 .dom_name = "local", 430 .dom_init = unp_init, 431 .dom_externalize = unp_externalize, 432 .dom_dispose = unp_dispose, 433 .dom_protosw = localsw, 434 .dom_protoswNPROTOSW = &localsw[nitems(localsw)] 435 }; 436 DOMAIN_SET(local); 437 438 static void 439 uipc_abort(struct socket *so) 440 { 441 struct unpcb *unp, *unp2; 442 443 unp = sotounpcb(so); 444 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 445 UNP_PCB_UNLOCK_ASSERT(unp); 446 447 UNP_PCB_LOCK(unp); 448 unp2 = unp->unp_conn; 449 if (unp2 != NULL) { 450 unp_pcb_hold(unp2); 451 UNP_PCB_UNLOCK(unp); 452 unp_drop(unp2); 453 } else 454 UNP_PCB_UNLOCK(unp); 455 } 456 457 static int 458 uipc_accept(struct socket *so, struct sockaddr **nam) 459 { 460 struct unpcb *unp, *unp2; 461 const struct sockaddr *sa; 462 463 /* 464 * Pass back name of connected socket, if it was bound and we are 465 * still connected (our peer may have closed already!). 466 */ 467 unp = sotounpcb(so); 468 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 469 470 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 471 UNP_LINK_RLOCK(); 472 unp2 = unp->unp_conn; 473 if (unp2 != NULL && unp2->unp_addr != NULL) { 474 UNP_PCB_LOCK(unp2); 475 sa = (struct sockaddr *) unp2->unp_addr; 476 bcopy(sa, *nam, sa->sa_len); 477 UNP_PCB_UNLOCK(unp2); 478 } else { 479 sa = &sun_noname; 480 bcopy(sa, *nam, sa->sa_len); 481 } 482 UNP_LINK_RUNLOCK(); 483 return (0); 484 } 485 486 static int 487 uipc_attach(struct socket *so, int proto, struct thread *td) 488 { 489 u_long sendspace, recvspace; 490 struct unpcb *unp; 491 int error; 492 bool locked; 493 494 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 495 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 496 switch (so->so_type) { 497 case SOCK_STREAM: 498 sendspace = unpst_sendspace; 499 recvspace = unpst_recvspace; 500 break; 501 502 case SOCK_DGRAM: 503 sendspace = unpdg_sendspace; 504 recvspace = unpdg_recvspace; 505 break; 506 507 case SOCK_SEQPACKET: 508 sendspace = unpsp_sendspace; 509 recvspace = unpsp_recvspace; 510 break; 511 512 default: 513 panic("uipc_attach"); 514 } 515 error = soreserve(so, sendspace, recvspace); 516 if (error) 517 return (error); 518 } 519 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 520 if (unp == NULL) 521 return (ENOBUFS); 522 LIST_INIT(&unp->unp_refs); 523 UNP_PCB_LOCK_INIT(unp); 524 unp->unp_socket = so; 525 so->so_pcb = unp; 526 unp->unp_refcount = 1; 527 if (so->so_listen != NULL) 528 unp->unp_flags |= UNP_NASCENT; 529 530 if ((locked = UNP_LINK_WOWNED()) == false) 531 UNP_LINK_WLOCK(); 532 533 unp->unp_gencnt = ++unp_gencnt; 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, 0); 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 unp->unp_gencnt = ++unp_gencnt; 782 --unp_count; 783 UNP_LINK_WUNLOCK(); 784 785 UNP_PCB_UNLOCK_ASSERT(unp); 786 restart: 787 if ((vp = unp->unp_vnode) != NULL) { 788 vplock = mtx_pool_find(mtxpool_sleep, vp); 789 mtx_lock(vplock); 790 } 791 UNP_PCB_LOCK(unp); 792 if (unp->unp_vnode != vp && 793 unp->unp_vnode != NULL) { 794 if (vplock) 795 mtx_unlock(vplock); 796 UNP_PCB_UNLOCK(unp); 797 goto restart; 798 } 799 if ((unp->unp_flags & UNP_NASCENT) != 0) { 800 goto teardown; 801 } 802 if ((vp = unp->unp_vnode) != NULL) { 803 VOP_UNP_DETACH(vp); 804 unp->unp_vnode = NULL; 805 } 806 if (__predict_false(unp == unp->unp_conn)) { 807 unp_disconnect(unp, unp); 808 unp2 = NULL; 809 goto connect_self; 810 } 811 if ((unp2 = unp->unp_conn) != NULL) { 812 unp_pcb_owned_lock2(unp, unp2, freeunp); 813 if (freeunp) 814 unp2 = NULL; 815 } 816 unp_pcb_hold(unp); 817 if (unp2 != NULL) { 818 unp_pcb_hold(unp2); 819 unp_disconnect(unp, unp2); 820 if (unp_pcb_rele(unp2) == 0) 821 UNP_PCB_UNLOCK(unp2); 822 } 823 connect_self: 824 UNP_PCB_UNLOCK(unp); 825 UNP_REF_LIST_LOCK(); 826 while (!LIST_EMPTY(&unp->unp_refs)) { 827 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 828 829 unp_pcb_hold(ref); 830 UNP_REF_LIST_UNLOCK(); 831 832 MPASS(ref != unp); 833 UNP_PCB_UNLOCK_ASSERT(ref); 834 unp_drop(ref); 835 UNP_REF_LIST_LOCK(); 836 } 837 838 UNP_REF_LIST_UNLOCK(); 839 UNP_PCB_LOCK(unp); 840 freeunp = unp_pcb_rele(unp); 841 MPASS(freeunp == 0); 842 local_unp_rights = unp_rights; 843 teardown: 844 unp->unp_socket->so_pcb = NULL; 845 saved_unp_addr = unp->unp_addr; 846 unp->unp_addr = NULL; 847 unp->unp_socket = NULL; 848 freeunp = unp_pcb_rele(unp); 849 if (saved_unp_addr != NULL) 850 free(saved_unp_addr, M_SONAME); 851 if (!freeunp) 852 UNP_PCB_UNLOCK(unp); 853 if (vp) { 854 mtx_unlock(vplock); 855 vrele(vp); 856 } 857 if (local_unp_rights) 858 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 859 } 860 861 static int 862 uipc_disconnect(struct socket *so) 863 { 864 struct unpcb *unp, *unp2; 865 int freed; 866 867 unp = sotounpcb(so); 868 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 869 870 UNP_PCB_LOCK(unp); 871 if ((unp2 = unp->unp_conn) == NULL) { 872 UNP_PCB_UNLOCK(unp); 873 return (0); 874 } 875 if (unp == unp2) { 876 if (unp_pcb_rele(unp) == 0) 877 UNP_PCB_UNLOCK(unp); 878 } 879 unp_pcb_owned_lock2(unp, unp2, freed); 880 if (__predict_false(freed)) { 881 UNP_PCB_UNLOCK(unp); 882 return (0); 883 } 884 unp_pcb_hold(unp2); 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_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 cru2x(td->td_ucred, &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 * Send to paired receive port, and then reduce send buffer 1182 * hiwater marks to maintain backpressure. Wake up readers. 1183 */ 1184 switch (so->so_type) { 1185 case SOCK_STREAM: 1186 if (control != NULL) { 1187 if (sbappendcontrol_locked(&so2->so_rcv, m, 1188 control)) 1189 control = NULL; 1190 } else 1191 sbappend_locked(&so2->so_rcv, m, flags); 1192 break; 1193 1194 case SOCK_SEQPACKET: { 1195 const struct sockaddr *from; 1196 1197 from = &sun_noname; 1198 /* 1199 * Don't check for space available in so2->so_rcv. 1200 * Unix domain sockets only check for space in the 1201 * sending sockbuf, and that check is performed one 1202 * level up the stack. 1203 */ 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_LINK_RLOCK(); 1268 if ((unp2 = unp->unp_conn) == NULL) { 1269 UNP_LINK_RUNLOCK(); 1270 for (int i = 0; i < count; i++) 1271 m = m_free(m); 1272 return (ECONNRESET); 1273 } 1274 UNP_PCB_LOCK(unp2); 1275 so2 = unp2->unp_socket; 1276 1277 SOCKBUF_LOCK(&so2->so_rcv); 1278 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1279 sorwakeup_locked(so2); 1280 else 1281 SOCKBUF_UNLOCK(&so2->so_rcv); 1282 1283 UNP_PCB_UNLOCK(unp2); 1284 UNP_LINK_RUNLOCK(); 1285 1286 return (error); 1287 } 1288 1289 static int 1290 uipc_sense(struct socket *so, struct stat *sb) 1291 { 1292 struct unpcb *unp; 1293 1294 unp = sotounpcb(so); 1295 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1296 1297 sb->st_blksize = so->so_snd.sb_hiwat; 1298 UNP_PCB_LOCK(unp); 1299 sb->st_dev = NODEV; 1300 if (unp->unp_ino == 0) 1301 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 1302 sb->st_ino = unp->unp_ino; 1303 UNP_PCB_UNLOCK(unp); 1304 return (0); 1305 } 1306 1307 static int 1308 uipc_shutdown(struct socket *so) 1309 { 1310 struct unpcb *unp; 1311 1312 unp = sotounpcb(so); 1313 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1314 1315 UNP_PCB_LOCK(unp); 1316 socantsendmore(so); 1317 unp_shutdown(unp); 1318 UNP_PCB_UNLOCK(unp); 1319 return (0); 1320 } 1321 1322 static int 1323 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1324 { 1325 struct unpcb *unp; 1326 const struct sockaddr *sa; 1327 1328 unp = sotounpcb(so); 1329 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1330 1331 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1332 UNP_PCB_LOCK(unp); 1333 if (unp->unp_addr != NULL) 1334 sa = (struct sockaddr *) unp->unp_addr; 1335 else 1336 sa = &sun_noname; 1337 bcopy(sa, *nam, sa->sa_len); 1338 UNP_PCB_UNLOCK(unp); 1339 return (0); 1340 } 1341 1342 static struct pr_usrreqs uipc_usrreqs_dgram = { 1343 .pru_abort = uipc_abort, 1344 .pru_accept = uipc_accept, 1345 .pru_attach = uipc_attach, 1346 .pru_bind = uipc_bind, 1347 .pru_bindat = uipc_bindat, 1348 .pru_connect = uipc_connect, 1349 .pru_connectat = uipc_connectat, 1350 .pru_connect2 = uipc_connect2, 1351 .pru_detach = uipc_detach, 1352 .pru_disconnect = uipc_disconnect, 1353 .pru_listen = uipc_listen, 1354 .pru_peeraddr = uipc_peeraddr, 1355 .pru_rcvd = uipc_rcvd, 1356 .pru_send = uipc_send, 1357 .pru_sense = uipc_sense, 1358 .pru_shutdown = uipc_shutdown, 1359 .pru_sockaddr = uipc_sockaddr, 1360 .pru_soreceive = soreceive_dgram, 1361 .pru_close = uipc_close, 1362 }; 1363 1364 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1365 .pru_abort = uipc_abort, 1366 .pru_accept = uipc_accept, 1367 .pru_attach = uipc_attach, 1368 .pru_bind = uipc_bind, 1369 .pru_bindat = uipc_bindat, 1370 .pru_connect = uipc_connect, 1371 .pru_connectat = uipc_connectat, 1372 .pru_connect2 = uipc_connect2, 1373 .pru_detach = uipc_detach, 1374 .pru_disconnect = uipc_disconnect, 1375 .pru_listen = uipc_listen, 1376 .pru_peeraddr = uipc_peeraddr, 1377 .pru_rcvd = uipc_rcvd, 1378 .pru_send = uipc_send, 1379 .pru_sense = uipc_sense, 1380 .pru_shutdown = uipc_shutdown, 1381 .pru_sockaddr = uipc_sockaddr, 1382 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1383 .pru_close = uipc_close, 1384 }; 1385 1386 static struct pr_usrreqs uipc_usrreqs_stream = { 1387 .pru_abort = uipc_abort, 1388 .pru_accept = uipc_accept, 1389 .pru_attach = uipc_attach, 1390 .pru_bind = uipc_bind, 1391 .pru_bindat = uipc_bindat, 1392 .pru_connect = uipc_connect, 1393 .pru_connectat = uipc_connectat, 1394 .pru_connect2 = uipc_connect2, 1395 .pru_detach = uipc_detach, 1396 .pru_disconnect = uipc_disconnect, 1397 .pru_listen = uipc_listen, 1398 .pru_peeraddr = uipc_peeraddr, 1399 .pru_rcvd = uipc_rcvd, 1400 .pru_send = uipc_send, 1401 .pru_ready = uipc_ready, 1402 .pru_sense = uipc_sense, 1403 .pru_shutdown = uipc_shutdown, 1404 .pru_sockaddr = uipc_sockaddr, 1405 .pru_soreceive = soreceive_generic, 1406 .pru_close = uipc_close, 1407 }; 1408 1409 static int 1410 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1411 { 1412 struct unpcb *unp; 1413 struct xucred xu; 1414 int error, optval; 1415 1416 if (sopt->sopt_level != 0) 1417 return (EINVAL); 1418 1419 unp = sotounpcb(so); 1420 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1421 error = 0; 1422 switch (sopt->sopt_dir) { 1423 case SOPT_GET: 1424 switch (sopt->sopt_name) { 1425 case LOCAL_PEERCRED: 1426 UNP_PCB_LOCK(unp); 1427 if (unp->unp_flags & UNP_HAVEPC) 1428 xu = unp->unp_peercred; 1429 else { 1430 if (so->so_type == SOCK_STREAM) 1431 error = ENOTCONN; 1432 else 1433 error = EINVAL; 1434 } 1435 UNP_PCB_UNLOCK(unp); 1436 if (error == 0) 1437 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1438 break; 1439 1440 case LOCAL_CREDS: 1441 /* Unlocked read. */ 1442 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1443 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1444 break; 1445 1446 case LOCAL_CONNWAIT: 1447 /* Unlocked read. */ 1448 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1449 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1450 break; 1451 1452 default: 1453 error = EOPNOTSUPP; 1454 break; 1455 } 1456 break; 1457 1458 case SOPT_SET: 1459 switch (sopt->sopt_name) { 1460 case LOCAL_CREDS: 1461 case LOCAL_CONNWAIT: 1462 error = sooptcopyin(sopt, &optval, sizeof(optval), 1463 sizeof(optval)); 1464 if (error) 1465 break; 1466 1467 #define OPTSET(bit) do { \ 1468 UNP_PCB_LOCK(unp); \ 1469 if (optval) \ 1470 unp->unp_flags |= bit; \ 1471 else \ 1472 unp->unp_flags &= ~bit; \ 1473 UNP_PCB_UNLOCK(unp); \ 1474 } while (0) 1475 1476 switch (sopt->sopt_name) { 1477 case LOCAL_CREDS: 1478 OPTSET(UNP_WANTCRED); 1479 break; 1480 1481 case LOCAL_CONNWAIT: 1482 OPTSET(UNP_CONNWAIT); 1483 break; 1484 1485 default: 1486 break; 1487 } 1488 break; 1489 #undef OPTSET 1490 default: 1491 error = ENOPROTOOPT; 1492 break; 1493 } 1494 break; 1495 1496 default: 1497 error = EOPNOTSUPP; 1498 break; 1499 } 1500 return (error); 1501 } 1502 1503 static int 1504 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1505 { 1506 1507 return (unp_connectat(AT_FDCWD, so, nam, td)); 1508 } 1509 1510 static int 1511 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1512 struct thread *td) 1513 { 1514 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1515 struct vnode *vp; 1516 struct socket *so2; 1517 struct unpcb *unp, *unp2, *unp3; 1518 struct nameidata nd; 1519 char buf[SOCK_MAXADDRLEN]; 1520 struct sockaddr *sa; 1521 cap_rights_t rights; 1522 int error, len, freed; 1523 struct mtx *vplock; 1524 1525 if (nam->sa_family != AF_UNIX) 1526 return (EAFNOSUPPORT); 1527 if (nam->sa_len > sizeof(struct sockaddr_un)) 1528 return (EINVAL); 1529 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1530 if (len <= 0) 1531 return (EINVAL); 1532 bcopy(soun->sun_path, buf, len); 1533 buf[len] = 0; 1534 1535 unp = sotounpcb(so); 1536 UNP_PCB_LOCK(unp); 1537 if (unp->unp_flags & UNP_CONNECTING) { 1538 UNP_PCB_UNLOCK(unp); 1539 return (EALREADY); 1540 } 1541 unp->unp_flags |= UNP_CONNECTING; 1542 UNP_PCB_UNLOCK(unp); 1543 1544 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1545 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1546 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td); 1547 error = namei(&nd); 1548 if (error) 1549 vp = NULL; 1550 else 1551 vp = nd.ni_vp; 1552 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1553 NDFREE(&nd, NDF_ONLY_PNBUF); 1554 if (error) 1555 goto bad; 1556 1557 if (vp->v_type != VSOCK) { 1558 error = ENOTSOCK; 1559 goto bad; 1560 } 1561 #ifdef MAC 1562 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1563 if (error) 1564 goto bad; 1565 #endif 1566 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1567 if (error) 1568 goto bad; 1569 1570 unp = sotounpcb(so); 1571 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1572 1573 vplock = mtx_pool_find(mtxpool_sleep, vp); 1574 mtx_lock(vplock); 1575 VOP_UNP_CONNECT(vp, &unp2); 1576 if (unp2 == NULL) { 1577 error = ECONNREFUSED; 1578 goto bad2; 1579 } 1580 so2 = unp2->unp_socket; 1581 if (so->so_type != so2->so_type) { 1582 error = EPROTOTYPE; 1583 goto bad2; 1584 } 1585 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1586 if (so2->so_options & SO_ACCEPTCONN) { 1587 CURVNET_SET(so2->so_vnet); 1588 so2 = sonewconn(so2, 0); 1589 CURVNET_RESTORE(); 1590 } else 1591 so2 = NULL; 1592 if (so2 == NULL) { 1593 error = ECONNREFUSED; 1594 goto bad2; 1595 } 1596 unp3 = sotounpcb(so2); 1597 unp_pcb_lock2(unp2, unp3); 1598 if (unp2->unp_addr != NULL) { 1599 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1600 unp3->unp_addr = (struct sockaddr_un *) sa; 1601 sa = NULL; 1602 } 1603 1604 /* 1605 * The connector's (client's) credentials are copied from its 1606 * process structure at the time of connect() (which is now). 1607 */ 1608 cru2x(td->td_ucred, &unp3->unp_peercred); 1609 unp3->unp_flags |= UNP_HAVEPC; 1610 1611 /* 1612 * The receiver's (server's) credentials are copied from the 1613 * unp_peercred member of socket on which the former called 1614 * listen(); uipc_listen() cached that process's credentials 1615 * at that time so we can use them now. 1616 */ 1617 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1618 sizeof(unp->unp_peercred)); 1619 unp->unp_flags |= UNP_HAVEPC; 1620 if (unp2->unp_flags & UNP_WANTCRED) 1621 unp3->unp_flags |= UNP_WANTCRED; 1622 UNP_PCB_UNLOCK(unp2); 1623 unp2 = unp3; 1624 unp_pcb_owned_lock2(unp2, unp, freed); 1625 if (__predict_false(freed)) { 1626 UNP_PCB_UNLOCK(unp2); 1627 error = ECONNREFUSED; 1628 goto bad2; 1629 } 1630 #ifdef MAC 1631 mac_socketpeer_set_from_socket(so, so2); 1632 mac_socketpeer_set_from_socket(so2, so); 1633 #endif 1634 } else { 1635 if (unp == unp2) 1636 UNP_PCB_LOCK(unp); 1637 else 1638 unp_pcb_lock2(unp, unp2); 1639 } 1640 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1641 sotounpcb(so2) == unp2, 1642 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1643 error = unp_connect2(so, so2, PRU_CONNECT); 1644 if (unp != unp2) 1645 UNP_PCB_UNLOCK(unp2); 1646 UNP_PCB_UNLOCK(unp); 1647 bad2: 1648 mtx_unlock(vplock); 1649 bad: 1650 if (vp != NULL) { 1651 vput(vp); 1652 } 1653 free(sa, M_SONAME); 1654 UNP_PCB_LOCK(unp); 1655 unp->unp_flags &= ~UNP_CONNECTING; 1656 UNP_PCB_UNLOCK(unp); 1657 return (error); 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 unp2->unp_flags &= ~UNP_NASCENT; 1677 unp->unp_conn = unp2; 1678 unp_pcb_hold(unp2); 1679 unp_pcb_hold(unp); 1680 switch (so->so_type) { 1681 case SOCK_DGRAM: 1682 UNP_REF_LIST_LOCK(); 1683 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1684 UNP_REF_LIST_UNLOCK(); 1685 soisconnected(so); 1686 break; 1687 1688 case SOCK_STREAM: 1689 case SOCK_SEQPACKET: 1690 unp2->unp_conn = unp; 1691 if (req == PRU_CONNECT && 1692 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1693 soisconnecting(so); 1694 else 1695 soisconnected(so); 1696 soisconnected(so2); 1697 break; 1698 1699 default: 1700 panic("unp_connect2"); 1701 } 1702 return (0); 1703 } 1704 1705 static void 1706 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1707 { 1708 struct socket *so, *so2; 1709 int freed __unused; 1710 1711 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1712 1713 UNP_PCB_LOCK_ASSERT(unp); 1714 UNP_PCB_LOCK_ASSERT(unp2); 1715 1716 if (unp->unp_conn == NULL && unp2->unp_conn == NULL) 1717 return; 1718 1719 MPASS(unp->unp_conn == unp2); 1720 unp->unp_conn = NULL; 1721 so = unp->unp_socket; 1722 so2 = unp2->unp_socket; 1723 switch (unp->unp_socket->so_type) { 1724 case SOCK_DGRAM: 1725 UNP_REF_LIST_LOCK(); 1726 LIST_REMOVE(unp, unp_reflink); 1727 UNP_REF_LIST_UNLOCK(); 1728 if (so) { 1729 SOCK_LOCK(so); 1730 so->so_state &= ~SS_ISCONNECTED; 1731 SOCK_UNLOCK(so); 1732 } 1733 break; 1734 1735 case SOCK_STREAM: 1736 case SOCK_SEQPACKET: 1737 if (so) 1738 soisdisconnected(so); 1739 MPASS(unp2->unp_conn == unp); 1740 unp2->unp_conn = NULL; 1741 if (so2) 1742 soisdisconnected(so2); 1743 break; 1744 } 1745 freed = unp_pcb_rele(unp); 1746 MPASS(freed == 0); 1747 freed = unp_pcb_rele(unp2); 1748 MPASS(freed == 0); 1749 } 1750 1751 /* 1752 * unp_pcblist() walks the global list of struct unpcb's to generate a 1753 * pointer list, bumping the refcount on each unpcb. It then copies them out 1754 * sequentially, validating the generation number on each to see if it has 1755 * been detached. All of this is necessary because copyout() may sleep on 1756 * disk I/O. 1757 */ 1758 static int 1759 unp_pcblist(SYSCTL_HANDLER_ARGS) 1760 { 1761 struct unpcb *unp, **unp_list; 1762 unp_gen_t gencnt; 1763 struct xunpgen *xug; 1764 struct unp_head *head; 1765 struct xunpcb *xu; 1766 u_int i; 1767 int error, freeunp, n; 1768 1769 switch ((intptr_t)arg1) { 1770 case SOCK_STREAM: 1771 head = &unp_shead; 1772 break; 1773 1774 case SOCK_DGRAM: 1775 head = &unp_dhead; 1776 break; 1777 1778 case SOCK_SEQPACKET: 1779 head = &unp_sphead; 1780 break; 1781 1782 default: 1783 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1784 } 1785 1786 /* 1787 * The process of preparing the PCB list is too time-consuming and 1788 * resource-intensive to repeat twice on every request. 1789 */ 1790 if (req->oldptr == NULL) { 1791 n = unp_count; 1792 req->oldidx = 2 * (sizeof *xug) 1793 + (n + n/8) * sizeof(struct xunpcb); 1794 return (0); 1795 } 1796 1797 if (req->newptr != NULL) 1798 return (EPERM); 1799 1800 /* 1801 * OK, now we're committed to doing something. 1802 */ 1803 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1804 UNP_LINK_RLOCK(); 1805 gencnt = unp_gencnt; 1806 n = unp_count; 1807 UNP_LINK_RUNLOCK(); 1808 1809 xug->xug_len = sizeof *xug; 1810 xug->xug_count = n; 1811 xug->xug_gen = gencnt; 1812 xug->xug_sogen = so_gencnt; 1813 error = SYSCTL_OUT(req, xug, sizeof *xug); 1814 if (error) { 1815 free(xug, M_TEMP); 1816 return (error); 1817 } 1818 1819 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1820 1821 UNP_LINK_RLOCK(); 1822 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1823 unp = LIST_NEXT(unp, unp_link)) { 1824 UNP_PCB_LOCK(unp); 1825 if (unp->unp_gencnt <= gencnt) { 1826 if (cr_cansee(req->td->td_ucred, 1827 unp->unp_socket->so_cred)) { 1828 UNP_PCB_UNLOCK(unp); 1829 continue; 1830 } 1831 unp_list[i++] = unp; 1832 unp_pcb_hold(unp); 1833 } 1834 UNP_PCB_UNLOCK(unp); 1835 } 1836 UNP_LINK_RUNLOCK(); 1837 n = i; /* In case we lost some during malloc. */ 1838 1839 error = 0; 1840 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1841 for (i = 0; i < n; i++) { 1842 unp = unp_list[i]; 1843 UNP_PCB_LOCK(unp); 1844 freeunp = unp_pcb_rele(unp); 1845 1846 if (freeunp == 0 && unp->unp_gencnt <= gencnt) { 1847 xu->xu_len = sizeof *xu; 1848 xu->xu_unpp = unp; 1849 /* 1850 * XXX - need more locking here to protect against 1851 * connect/disconnect races for SMP. 1852 */ 1853 if (unp->unp_addr != NULL) 1854 bcopy(unp->unp_addr, &xu->xu_addr, 1855 unp->unp_addr->sun_len); 1856 else 1857 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1858 if (unp->unp_conn != NULL && 1859 unp->unp_conn->unp_addr != NULL) 1860 bcopy(unp->unp_conn->unp_addr, 1861 &xu->xu_caddr, 1862 unp->unp_conn->unp_addr->sun_len); 1863 else 1864 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1865 xu->unp_vnode = unp->unp_vnode; 1866 xu->unp_conn = unp->unp_conn; 1867 xu->xu_firstref = LIST_FIRST(&unp->unp_refs); 1868 xu->xu_nextref = LIST_NEXT(unp, unp_reflink); 1869 xu->unp_gencnt = unp->unp_gencnt; 1870 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1871 UNP_PCB_UNLOCK(unp); 1872 error = SYSCTL_OUT(req, xu, sizeof *xu); 1873 } else if (freeunp == 0) 1874 UNP_PCB_UNLOCK(unp); 1875 } 1876 free(xu, M_TEMP); 1877 if (!error) { 1878 /* 1879 * Give the user an updated idea of our state. If the 1880 * generation differs from what we told her before, she knows 1881 * that something happened while we were processing this 1882 * request, and it might be necessary to retry. 1883 */ 1884 xug->xug_gen = unp_gencnt; 1885 xug->xug_sogen = so_gencnt; 1886 xug->xug_count = unp_count; 1887 error = SYSCTL_OUT(req, xug, sizeof *xug); 1888 } 1889 free(unp_list, M_TEMP); 1890 free(xug, M_TEMP); 1891 return (error); 1892 } 1893 1894 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 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, CTLTYPE_OPAQUE | CTLFLAG_RD, 1898 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1899 "List of active local stream sockets"); 1900 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1901 CTLTYPE_OPAQUE | CTLFLAG_RD, 1902 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1903 "List of active local seqpacket sockets"); 1904 1905 static void 1906 unp_shutdown(struct unpcb *unp) 1907 { 1908 struct unpcb *unp2; 1909 struct socket *so; 1910 1911 UNP_PCB_LOCK_ASSERT(unp); 1912 1913 unp2 = unp->unp_conn; 1914 if ((unp->unp_socket->so_type == SOCK_STREAM || 1915 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1916 so = unp2->unp_socket; 1917 if (so != NULL) 1918 socantrcvmore(so); 1919 } 1920 } 1921 1922 static void 1923 unp_drop(struct unpcb *unp) 1924 { 1925 struct socket *so = unp->unp_socket; 1926 struct unpcb *unp2; 1927 int freed; 1928 1929 /* 1930 * Regardless of whether the socket's peer dropped the connection 1931 * with this socket by aborting or disconnecting, POSIX requires 1932 * that ECONNRESET is returned. 1933 */ 1934 /* acquire a reference so that unp isn't freed from underneath us */ 1935 1936 UNP_PCB_LOCK(unp); 1937 if (so) 1938 so->so_error = ECONNRESET; 1939 unp2 = unp->unp_conn; 1940 if (unp2 == unp) { 1941 unp_disconnect(unp, unp2); 1942 } else if (unp2 != NULL) { 1943 unp_pcb_hold(unp2); 1944 unp_pcb_owned_lock2(unp, unp2, freed); 1945 unp_disconnect(unp, unp2); 1946 if (unp_pcb_rele(unp2) == 0) 1947 UNP_PCB_UNLOCK(unp2); 1948 } 1949 if (unp_pcb_rele(unp) == 0) 1950 UNP_PCB_UNLOCK(unp); 1951 } 1952 1953 static void 1954 unp_freerights(struct filedescent **fdep, int fdcount) 1955 { 1956 struct file *fp; 1957 int i; 1958 1959 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1960 1961 for (i = 0; i < fdcount; i++) { 1962 fp = fdep[i]->fde_file; 1963 filecaps_free(&fdep[i]->fde_caps); 1964 unp_discard(fp); 1965 } 1966 free(fdep[0], M_FILECAPS); 1967 } 1968 1969 static int 1970 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 1971 { 1972 struct thread *td = curthread; /* XXX */ 1973 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1974 int i; 1975 int *fdp; 1976 struct filedesc *fdesc = td->td_proc->p_fd; 1977 struct filedescent **fdep; 1978 void *data; 1979 socklen_t clen = control->m_len, datalen; 1980 int error, newfds; 1981 u_int newlen; 1982 1983 UNP_LINK_UNLOCK_ASSERT(); 1984 1985 error = 0; 1986 if (controlp != NULL) /* controlp == NULL => free control messages */ 1987 *controlp = NULL; 1988 while (cm != NULL) { 1989 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1990 error = EINVAL; 1991 break; 1992 } 1993 data = CMSG_DATA(cm); 1994 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1995 if (cm->cmsg_level == SOL_SOCKET 1996 && cm->cmsg_type == SCM_RIGHTS) { 1997 newfds = datalen / sizeof(*fdep); 1998 if (newfds == 0) 1999 goto next; 2000 fdep = data; 2001 2002 /* If we're not outputting the descriptors free them. */ 2003 if (error || controlp == NULL) { 2004 unp_freerights(fdep, newfds); 2005 goto next; 2006 } 2007 FILEDESC_XLOCK(fdesc); 2008 2009 /* 2010 * Now change each pointer to an fd in the global 2011 * table to an integer that is the index to the local 2012 * fd table entry that we set up to point to the 2013 * global one we are transferring. 2014 */ 2015 newlen = newfds * sizeof(int); 2016 *controlp = sbcreatecontrol(NULL, newlen, 2017 SCM_RIGHTS, SOL_SOCKET); 2018 if (*controlp == NULL) { 2019 FILEDESC_XUNLOCK(fdesc); 2020 error = E2BIG; 2021 unp_freerights(fdep, newfds); 2022 goto next; 2023 } 2024 2025 fdp = (int *) 2026 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2027 if (fdallocn(td, 0, fdp, newfds) != 0) { 2028 FILEDESC_XUNLOCK(fdesc); 2029 error = EMSGSIZE; 2030 unp_freerights(fdep, newfds); 2031 m_freem(*controlp); 2032 *controlp = NULL; 2033 goto next; 2034 } 2035 for (i = 0; i < newfds; i++, fdp++) { 2036 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2037 (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0, 2038 &fdep[i]->fde_caps); 2039 unp_externalize_fp(fdep[i]->fde_file); 2040 } 2041 FILEDESC_XUNLOCK(fdesc); 2042 free(fdep[0], M_FILECAPS); 2043 } else { 2044 /* We can just copy anything else across. */ 2045 if (error || controlp == NULL) 2046 goto next; 2047 *controlp = sbcreatecontrol(NULL, datalen, 2048 cm->cmsg_type, cm->cmsg_level); 2049 if (*controlp == NULL) { 2050 error = ENOBUFS; 2051 goto next; 2052 } 2053 bcopy(data, 2054 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2055 datalen); 2056 } 2057 controlp = &(*controlp)->m_next; 2058 2059 next: 2060 if (CMSG_SPACE(datalen) < clen) { 2061 clen -= CMSG_SPACE(datalen); 2062 cm = (struct cmsghdr *) 2063 ((caddr_t)cm + CMSG_SPACE(datalen)); 2064 } else { 2065 clen = 0; 2066 cm = NULL; 2067 } 2068 } 2069 2070 m_freem(control); 2071 return (error); 2072 } 2073 2074 static void 2075 unp_zone_change(void *tag) 2076 { 2077 2078 uma_zone_set_max(unp_zone, maxsockets); 2079 } 2080 2081 static void 2082 unp_init(void) 2083 { 2084 2085 #ifdef VIMAGE 2086 if (!IS_DEFAULT_VNET(curvnet)) 2087 return; 2088 #endif 2089 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 2090 NULL, NULL, UMA_ALIGN_CACHE, 0); 2091 if (unp_zone == NULL) 2092 panic("unp_init"); 2093 uma_zone_set_max(unp_zone, maxsockets); 2094 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2095 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2096 NULL, EVENTHANDLER_PRI_ANY); 2097 LIST_INIT(&unp_dhead); 2098 LIST_INIT(&unp_shead); 2099 LIST_INIT(&unp_sphead); 2100 SLIST_INIT(&unp_defers); 2101 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2102 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2103 UNP_LINK_LOCK_INIT(); 2104 UNP_DEFERRED_LOCK_INIT(); 2105 } 2106 2107 static int 2108 unp_internalize(struct mbuf **controlp, struct thread *td) 2109 { 2110 struct mbuf *control = *controlp; 2111 struct proc *p = td->td_proc; 2112 struct filedesc *fdesc = p->p_fd; 2113 struct bintime *bt; 2114 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2115 struct cmsgcred *cmcred; 2116 struct filedescent *fde, **fdep, *fdev; 2117 struct file *fp; 2118 struct timeval *tv; 2119 struct timespec *ts; 2120 int i, *fdp; 2121 void *data; 2122 socklen_t clen = control->m_len, datalen; 2123 int error, oldfds; 2124 u_int newlen; 2125 2126 UNP_LINK_UNLOCK_ASSERT(); 2127 2128 error = 0; 2129 *controlp = NULL; 2130 while (cm != NULL) { 2131 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2132 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2133 error = EINVAL; 2134 goto out; 2135 } 2136 data = CMSG_DATA(cm); 2137 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2138 2139 switch (cm->cmsg_type) { 2140 /* 2141 * Fill in credential information. 2142 */ 2143 case SCM_CREDS: 2144 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2145 SCM_CREDS, SOL_SOCKET); 2146 if (*controlp == NULL) { 2147 error = ENOBUFS; 2148 goto out; 2149 } 2150 cmcred = (struct cmsgcred *) 2151 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2152 cmcred->cmcred_pid = p->p_pid; 2153 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2154 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2155 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2156 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2157 CMGROUP_MAX); 2158 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2159 cmcred->cmcred_groups[i] = 2160 td->td_ucred->cr_groups[i]; 2161 break; 2162 2163 case SCM_RIGHTS: 2164 oldfds = datalen / sizeof (int); 2165 if (oldfds == 0) 2166 break; 2167 /* 2168 * Check that all the FDs passed in refer to legal 2169 * files. If not, reject the entire operation. 2170 */ 2171 fdp = data; 2172 FILEDESC_SLOCK(fdesc); 2173 for (i = 0; i < oldfds; i++, fdp++) { 2174 fp = fget_locked(fdesc, *fdp); 2175 if (fp == NULL) { 2176 FILEDESC_SUNLOCK(fdesc); 2177 error = EBADF; 2178 goto out; 2179 } 2180 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2181 FILEDESC_SUNLOCK(fdesc); 2182 error = EOPNOTSUPP; 2183 goto out; 2184 } 2185 2186 } 2187 2188 /* 2189 * Now replace the integer FDs with pointers to the 2190 * file structure and capability rights. 2191 */ 2192 newlen = oldfds * sizeof(fdep[0]); 2193 *controlp = sbcreatecontrol(NULL, newlen, 2194 SCM_RIGHTS, SOL_SOCKET); 2195 if (*controlp == NULL) { 2196 FILEDESC_SUNLOCK(fdesc); 2197 error = E2BIG; 2198 goto out; 2199 } 2200 fdp = data; 2201 fdep = (struct filedescent **) 2202 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2203 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2204 M_WAITOK); 2205 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2206 fde = &fdesc->fd_ofiles[*fdp]; 2207 fdep[i] = fdev; 2208 fdep[i]->fde_file = fde->fde_file; 2209 filecaps_copy(&fde->fde_caps, 2210 &fdep[i]->fde_caps, true); 2211 unp_internalize_fp(fdep[i]->fde_file); 2212 } 2213 FILEDESC_SUNLOCK(fdesc); 2214 break; 2215 2216 case SCM_TIMESTAMP: 2217 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2218 SCM_TIMESTAMP, SOL_SOCKET); 2219 if (*controlp == NULL) { 2220 error = ENOBUFS; 2221 goto out; 2222 } 2223 tv = (struct timeval *) 2224 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2225 microtime(tv); 2226 break; 2227 2228 case SCM_BINTIME: 2229 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2230 SCM_BINTIME, SOL_SOCKET); 2231 if (*controlp == NULL) { 2232 error = ENOBUFS; 2233 goto out; 2234 } 2235 bt = (struct bintime *) 2236 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2237 bintime(bt); 2238 break; 2239 2240 case SCM_REALTIME: 2241 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2242 SCM_REALTIME, SOL_SOCKET); 2243 if (*controlp == NULL) { 2244 error = ENOBUFS; 2245 goto out; 2246 } 2247 ts = (struct timespec *) 2248 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2249 nanotime(ts); 2250 break; 2251 2252 case SCM_MONOTONIC: 2253 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2254 SCM_MONOTONIC, SOL_SOCKET); 2255 if (*controlp == NULL) { 2256 error = ENOBUFS; 2257 goto out; 2258 } 2259 ts = (struct timespec *) 2260 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2261 nanouptime(ts); 2262 break; 2263 2264 default: 2265 error = EINVAL; 2266 goto out; 2267 } 2268 2269 controlp = &(*controlp)->m_next; 2270 if (CMSG_SPACE(datalen) < clen) { 2271 clen -= CMSG_SPACE(datalen); 2272 cm = (struct cmsghdr *) 2273 ((caddr_t)cm + CMSG_SPACE(datalen)); 2274 } else { 2275 clen = 0; 2276 cm = NULL; 2277 } 2278 } 2279 2280 out: 2281 m_freem(control); 2282 return (error); 2283 } 2284 2285 static struct mbuf * 2286 unp_addsockcred(struct thread *td, struct mbuf *control) 2287 { 2288 struct mbuf *m, *n, *n_prev; 2289 struct sockcred *sc; 2290 const struct cmsghdr *cm; 2291 int ngroups; 2292 int i; 2293 2294 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2295 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 2296 if (m == NULL) 2297 return (control); 2298 2299 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 2300 sc->sc_uid = td->td_ucred->cr_ruid; 2301 sc->sc_euid = td->td_ucred->cr_uid; 2302 sc->sc_gid = td->td_ucred->cr_rgid; 2303 sc->sc_egid = td->td_ucred->cr_gid; 2304 sc->sc_ngroups = ngroups; 2305 for (i = 0; i < sc->sc_ngroups; i++) 2306 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2307 2308 /* 2309 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2310 * created SCM_CREDS control message (struct sockcred) has another 2311 * format. 2312 */ 2313 if (control != NULL) 2314 for (n = control, n_prev = NULL; n != NULL;) { 2315 cm = mtod(n, struct cmsghdr *); 2316 if (cm->cmsg_level == SOL_SOCKET && 2317 cm->cmsg_type == SCM_CREDS) { 2318 if (n_prev == NULL) 2319 control = n->m_next; 2320 else 2321 n_prev->m_next = n->m_next; 2322 n = m_free(n); 2323 } else { 2324 n_prev = n; 2325 n = n->m_next; 2326 } 2327 } 2328 2329 /* Prepend it to the head. */ 2330 m->m_next = control; 2331 return (m); 2332 } 2333 2334 static struct unpcb * 2335 fptounp(struct file *fp) 2336 { 2337 struct socket *so; 2338 2339 if (fp->f_type != DTYPE_SOCKET) 2340 return (NULL); 2341 if ((so = fp->f_data) == NULL) 2342 return (NULL); 2343 if (so->so_proto->pr_domain != &localdomain) 2344 return (NULL); 2345 return sotounpcb(so); 2346 } 2347 2348 static void 2349 unp_discard(struct file *fp) 2350 { 2351 struct unp_defer *dr; 2352 2353 if (unp_externalize_fp(fp)) { 2354 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2355 dr->ud_fp = fp; 2356 UNP_DEFERRED_LOCK(); 2357 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2358 UNP_DEFERRED_UNLOCK(); 2359 atomic_add_int(&unp_defers_count, 1); 2360 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2361 } else 2362 (void) closef(fp, (struct thread *)NULL); 2363 } 2364 2365 static void 2366 unp_process_defers(void *arg __unused, int pending) 2367 { 2368 struct unp_defer *dr; 2369 SLIST_HEAD(, unp_defer) drl; 2370 int count; 2371 2372 SLIST_INIT(&drl); 2373 for (;;) { 2374 UNP_DEFERRED_LOCK(); 2375 if (SLIST_FIRST(&unp_defers) == NULL) { 2376 UNP_DEFERRED_UNLOCK(); 2377 break; 2378 } 2379 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2380 UNP_DEFERRED_UNLOCK(); 2381 count = 0; 2382 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2383 SLIST_REMOVE_HEAD(&drl, ud_link); 2384 closef(dr->ud_fp, NULL); 2385 free(dr, M_TEMP); 2386 count++; 2387 } 2388 atomic_add_int(&unp_defers_count, -count); 2389 } 2390 } 2391 2392 static void 2393 unp_internalize_fp(struct file *fp) 2394 { 2395 struct unpcb *unp; 2396 2397 UNP_LINK_WLOCK(); 2398 if ((unp = fptounp(fp)) != NULL) { 2399 unp->unp_file = fp; 2400 unp->unp_msgcount++; 2401 } 2402 fhold(fp); 2403 unp_rights++; 2404 UNP_LINK_WUNLOCK(); 2405 } 2406 2407 static int 2408 unp_externalize_fp(struct file *fp) 2409 { 2410 struct unpcb *unp; 2411 int ret; 2412 2413 UNP_LINK_WLOCK(); 2414 if ((unp = fptounp(fp)) != NULL) { 2415 unp->unp_msgcount--; 2416 ret = 1; 2417 } else 2418 ret = 0; 2419 unp_rights--; 2420 UNP_LINK_WUNLOCK(); 2421 return (ret); 2422 } 2423 2424 /* 2425 * unp_defer indicates whether additional work has been defered for a future 2426 * pass through unp_gc(). It is thread local and does not require explicit 2427 * synchronization. 2428 */ 2429 static int unp_marked; 2430 static int unp_unreachable; 2431 2432 static void 2433 unp_accessable(struct filedescent **fdep, int fdcount) 2434 { 2435 struct unpcb *unp; 2436 struct file *fp; 2437 int i; 2438 2439 for (i = 0; i < fdcount; i++) { 2440 fp = fdep[i]->fde_file; 2441 if ((unp = fptounp(fp)) == NULL) 2442 continue; 2443 if (unp->unp_gcflag & UNPGC_REF) 2444 continue; 2445 unp->unp_gcflag &= ~UNPGC_DEAD; 2446 unp->unp_gcflag |= UNPGC_REF; 2447 unp_marked++; 2448 } 2449 } 2450 2451 static void 2452 unp_gc_process(struct unpcb *unp) 2453 { 2454 struct socket *so, *soa; 2455 struct file *fp; 2456 2457 /* Already processed. */ 2458 if (unp->unp_gcflag & UNPGC_SCANNED) 2459 return; 2460 fp = unp->unp_file; 2461 2462 /* 2463 * Check for a socket potentially in a cycle. It must be in a 2464 * queue as indicated by msgcount, and this must equal the file 2465 * reference count. Note that when msgcount is 0 the file is NULL. 2466 */ 2467 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2468 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2469 unp->unp_gcflag |= UNPGC_DEAD; 2470 unp_unreachable++; 2471 return; 2472 } 2473 2474 so = unp->unp_socket; 2475 SOCK_LOCK(so); 2476 if (SOLISTENING(so)) { 2477 /* 2478 * Mark all sockets in our accept queue. 2479 */ 2480 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2481 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2482 continue; 2483 SOCKBUF_LOCK(&soa->so_rcv); 2484 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2485 SOCKBUF_UNLOCK(&soa->so_rcv); 2486 } 2487 } else { 2488 /* 2489 * Mark all sockets we reference with RIGHTS. 2490 */ 2491 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2492 SOCKBUF_LOCK(&so->so_rcv); 2493 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2494 SOCKBUF_UNLOCK(&so->so_rcv); 2495 } 2496 } 2497 SOCK_UNLOCK(so); 2498 unp->unp_gcflag |= UNPGC_SCANNED; 2499 } 2500 2501 static int unp_recycled; 2502 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2503 "Number of unreachable sockets claimed by the garbage collector."); 2504 2505 static int unp_taskcount; 2506 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2507 "Number of times the garbage collector has run."); 2508 2509 static void 2510 unp_gc(__unused void *arg, int pending) 2511 { 2512 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2513 NULL }; 2514 struct unp_head **head; 2515 struct file *f, **unref; 2516 struct unpcb *unp; 2517 int i, total; 2518 2519 unp_taskcount++; 2520 UNP_LINK_RLOCK(); 2521 /* 2522 * First clear all gc flags from previous runs, apart from 2523 * UNPGC_IGNORE_RIGHTS. 2524 */ 2525 for (head = heads; *head != NULL; head++) 2526 LIST_FOREACH(unp, *head, unp_link) 2527 unp->unp_gcflag = 2528 (unp->unp_gcflag & UNPGC_IGNORE_RIGHTS); 2529 2530 /* 2531 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2532 * is reachable all of the sockets it references are reachable. 2533 * Stop the scan once we do a complete loop without discovering 2534 * a new reachable socket. 2535 */ 2536 do { 2537 unp_unreachable = 0; 2538 unp_marked = 0; 2539 for (head = heads; *head != NULL; head++) 2540 LIST_FOREACH(unp, *head, unp_link) 2541 unp_gc_process(unp); 2542 } while (unp_marked); 2543 UNP_LINK_RUNLOCK(); 2544 if (unp_unreachable == 0) 2545 return; 2546 2547 /* 2548 * Allocate space for a local list of dead unpcbs. 2549 */ 2550 unref = malloc(unp_unreachable * sizeof(struct file *), 2551 M_TEMP, M_WAITOK); 2552 2553 /* 2554 * Iterate looking for sockets which have been specifically marked 2555 * as as unreachable and store them locally. 2556 */ 2557 UNP_LINK_RLOCK(); 2558 for (total = 0, head = heads; *head != NULL; head++) 2559 LIST_FOREACH(unp, *head, unp_link) 2560 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2561 f = unp->unp_file; 2562 if (unp->unp_msgcount == 0 || f == NULL || 2563 f->f_count != unp->unp_msgcount) 2564 continue; 2565 unref[total++] = f; 2566 fhold(f); 2567 KASSERT(total <= unp_unreachable, 2568 ("unp_gc: incorrect unreachable count.")); 2569 } 2570 UNP_LINK_RUNLOCK(); 2571 2572 /* 2573 * Now flush all sockets, free'ing rights. This will free the 2574 * struct files associated with these sockets but leave each socket 2575 * with one remaining ref. 2576 */ 2577 for (i = 0; i < total; i++) { 2578 struct socket *so; 2579 2580 so = unref[i]->f_data; 2581 CURVNET_SET(so->so_vnet); 2582 sorflush(so); 2583 CURVNET_RESTORE(); 2584 } 2585 2586 /* 2587 * And finally release the sockets so they can be reclaimed. 2588 */ 2589 for (i = 0; i < total; i++) 2590 fdrop(unref[i], NULL); 2591 unp_recycled += total; 2592 free(unref, M_TEMP); 2593 } 2594 2595 static void 2596 unp_dispose_mbuf(struct mbuf *m) 2597 { 2598 2599 if (m) 2600 unp_scan(m, unp_freerights); 2601 } 2602 2603 /* 2604 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2605 */ 2606 static void 2607 unp_dispose(struct socket *so) 2608 { 2609 struct unpcb *unp; 2610 2611 unp = sotounpcb(so); 2612 UNP_LINK_WLOCK(); 2613 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2614 UNP_LINK_WUNLOCK(); 2615 if (!SOLISTENING(so)) 2616 unp_dispose_mbuf(so->so_rcv.sb_mb); 2617 } 2618 2619 static void 2620 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2621 { 2622 struct mbuf *m; 2623 struct cmsghdr *cm; 2624 void *data; 2625 socklen_t clen, datalen; 2626 2627 while (m0 != NULL) { 2628 for (m = m0; m; m = m->m_next) { 2629 if (m->m_type != MT_CONTROL) 2630 continue; 2631 2632 cm = mtod(m, struct cmsghdr *); 2633 clen = m->m_len; 2634 2635 while (cm != NULL) { 2636 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2637 break; 2638 2639 data = CMSG_DATA(cm); 2640 datalen = (caddr_t)cm + cm->cmsg_len 2641 - (caddr_t)data; 2642 2643 if (cm->cmsg_level == SOL_SOCKET && 2644 cm->cmsg_type == SCM_RIGHTS) { 2645 (*op)(data, datalen / 2646 sizeof(struct filedescent *)); 2647 } 2648 2649 if (CMSG_SPACE(datalen) < clen) { 2650 clen -= CMSG_SPACE(datalen); 2651 cm = (struct cmsghdr *) 2652 ((caddr_t)cm + CMSG_SPACE(datalen)); 2653 } else { 2654 clen = 0; 2655 cm = NULL; 2656 } 2657 } 2658 } 2659 m0 = m0->m_nextpkt; 2660 } 2661 } 2662 2663 /* 2664 * A helper function called by VFS before socket-type vnode reclamation. 2665 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2666 * use count. 2667 */ 2668 void 2669 vfs_unp_reclaim(struct vnode *vp) 2670 { 2671 struct unpcb *unp; 2672 int active; 2673 struct mtx *vplock; 2674 2675 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2676 KASSERT(vp->v_type == VSOCK, 2677 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2678 2679 active = 0; 2680 vplock = mtx_pool_find(mtxpool_sleep, vp); 2681 mtx_lock(vplock); 2682 VOP_UNP_CONNECT(vp, &unp); 2683 if (unp == NULL) 2684 goto done; 2685 UNP_PCB_LOCK(unp); 2686 if (unp->unp_vnode == vp) { 2687 VOP_UNP_DETACH(vp); 2688 unp->unp_vnode = NULL; 2689 active = 1; 2690 } 2691 UNP_PCB_UNLOCK(unp); 2692 done: 2693 mtx_unlock(vplock); 2694 if (active) 2695 vunref(vp); 2696 } 2697 2698 #ifdef DDB 2699 static void 2700 db_print_indent(int indent) 2701 { 2702 int i; 2703 2704 for (i = 0; i < indent; i++) 2705 db_printf(" "); 2706 } 2707 2708 static void 2709 db_print_unpflags(int unp_flags) 2710 { 2711 int comma; 2712 2713 comma = 0; 2714 if (unp_flags & UNP_HAVEPC) { 2715 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2716 comma = 1; 2717 } 2718 if (unp_flags & UNP_WANTCRED) { 2719 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2720 comma = 1; 2721 } 2722 if (unp_flags & UNP_CONNWAIT) { 2723 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2724 comma = 1; 2725 } 2726 if (unp_flags & UNP_CONNECTING) { 2727 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2728 comma = 1; 2729 } 2730 if (unp_flags & UNP_BINDING) { 2731 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2732 comma = 1; 2733 } 2734 } 2735 2736 static void 2737 db_print_xucred(int indent, struct xucred *xu) 2738 { 2739 int comma, i; 2740 2741 db_print_indent(indent); 2742 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2743 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2744 db_print_indent(indent); 2745 db_printf("cr_groups: "); 2746 comma = 0; 2747 for (i = 0; i < xu->cr_ngroups; i++) { 2748 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2749 comma = 1; 2750 } 2751 db_printf("\n"); 2752 } 2753 2754 static void 2755 db_print_unprefs(int indent, struct unp_head *uh) 2756 { 2757 struct unpcb *unp; 2758 int counter; 2759 2760 counter = 0; 2761 LIST_FOREACH(unp, uh, unp_reflink) { 2762 if (counter % 4 == 0) 2763 db_print_indent(indent); 2764 db_printf("%p ", unp); 2765 if (counter % 4 == 3) 2766 db_printf("\n"); 2767 counter++; 2768 } 2769 if (counter != 0 && counter % 4 != 0) 2770 db_printf("\n"); 2771 } 2772 2773 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2774 { 2775 struct unpcb *unp; 2776 2777 if (!have_addr) { 2778 db_printf("usage: show unpcb <addr>\n"); 2779 return; 2780 } 2781 unp = (struct unpcb *)addr; 2782 2783 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2784 unp->unp_vnode); 2785 2786 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2787 unp->unp_conn); 2788 2789 db_printf("unp_refs:\n"); 2790 db_print_unprefs(2, &unp->unp_refs); 2791 2792 /* XXXRW: Would be nice to print the full address, if any. */ 2793 db_printf("unp_addr: %p\n", unp->unp_addr); 2794 2795 db_printf("unp_gencnt: %llu\n", 2796 (unsigned long long)unp->unp_gencnt); 2797 2798 db_printf("unp_flags: %x (", unp->unp_flags); 2799 db_print_unpflags(unp->unp_flags); 2800 db_printf(")\n"); 2801 2802 db_printf("unp_peercred:\n"); 2803 db_print_xucred(2, &unp->unp_peercred); 2804 2805 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2806 } 2807 #endif 2808