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, 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 (__predict_true(unp != unp2)) { 876 unp_pcb_owned_lock2(unp, unp2, freed); 877 if (__predict_false(freed)) { 878 UNP_PCB_UNLOCK(unp); 879 return (0); 880 } 881 unp_pcb_hold(unp2); 882 } 883 unp_pcb_hold(unp); 884 unp_disconnect(unp, unp2); 885 if (unp_pcb_rele(unp) == 0) 886 UNP_PCB_UNLOCK(unp); 887 if ((unp != unp2) && unp_pcb_rele(unp2) == 0) 888 UNP_PCB_UNLOCK(unp2); 889 return (0); 890 } 891 892 static int 893 uipc_listen(struct socket *so, int backlog, struct thread *td) 894 { 895 struct unpcb *unp; 896 int error; 897 898 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 899 return (EOPNOTSUPP); 900 901 unp = sotounpcb(so); 902 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 903 904 UNP_PCB_LOCK(unp); 905 if (unp->unp_vnode == NULL) { 906 /* Already connected or not bound to an address. */ 907 error = unp->unp_conn != NULL ? EINVAL : EDESTADDRREQ; 908 UNP_PCB_UNLOCK(unp); 909 return (error); 910 } 911 912 SOCK_LOCK(so); 913 error = solisten_proto_check(so); 914 if (error == 0) { 915 cru2x(td->td_ucred, &unp->unp_peercred); 916 solisten_proto(so, backlog); 917 } 918 SOCK_UNLOCK(so); 919 UNP_PCB_UNLOCK(unp); 920 return (error); 921 } 922 923 static int 924 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 925 { 926 struct unpcb *unp, *unp2; 927 const struct sockaddr *sa; 928 929 unp = sotounpcb(so); 930 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 931 932 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 933 UNP_LINK_RLOCK(); 934 /* 935 * XXX: It seems that this test always fails even when connection is 936 * established. So, this else clause is added as workaround to 937 * return PF_LOCAL sockaddr. 938 */ 939 unp2 = unp->unp_conn; 940 if (unp2 != NULL) { 941 UNP_PCB_LOCK(unp2); 942 if (unp2->unp_addr != NULL) 943 sa = (struct sockaddr *) unp2->unp_addr; 944 else 945 sa = &sun_noname; 946 bcopy(sa, *nam, sa->sa_len); 947 UNP_PCB_UNLOCK(unp2); 948 } else { 949 sa = &sun_noname; 950 bcopy(sa, *nam, sa->sa_len); 951 } 952 UNP_LINK_RUNLOCK(); 953 return (0); 954 } 955 956 static int 957 uipc_rcvd(struct socket *so, int flags) 958 { 959 struct unpcb *unp, *unp2; 960 struct socket *so2; 961 u_int mbcnt, sbcc; 962 963 unp = sotounpcb(so); 964 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 965 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 966 ("%s: socktype %d", __func__, so->so_type)); 967 968 /* 969 * Adjust backpressure on sender and wakeup any waiting to write. 970 * 971 * The unp lock is acquired to maintain the validity of the unp_conn 972 * pointer; no lock on unp2 is required as unp2->unp_socket will be 973 * static as long as we don't permit unp2 to disconnect from unp, 974 * which is prevented by the lock on unp. We cache values from 975 * so_rcv to avoid holding the so_rcv lock over the entire 976 * transaction on the remote so_snd. 977 */ 978 SOCKBUF_LOCK(&so->so_rcv); 979 mbcnt = so->so_rcv.sb_mbcnt; 980 sbcc = sbavail(&so->so_rcv); 981 SOCKBUF_UNLOCK(&so->so_rcv); 982 /* 983 * There is a benign race condition at this point. If we're planning to 984 * clear SB_STOP, but uipc_send is called on the connected socket at 985 * this instant, it might add data to the sockbuf and set SB_STOP. Then 986 * we would erroneously clear SB_STOP below, even though the sockbuf is 987 * full. The race is benign because the only ill effect is to allow the 988 * sockbuf to exceed its size limit, and the size limits are not 989 * strictly guaranteed anyway. 990 */ 991 UNP_PCB_LOCK(unp); 992 unp2 = unp->unp_conn; 993 if (unp2 == NULL) { 994 UNP_PCB_UNLOCK(unp); 995 return (0); 996 } 997 so2 = unp2->unp_socket; 998 SOCKBUF_LOCK(&so2->so_snd); 999 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 1000 so2->so_snd.sb_flags &= ~SB_STOP; 1001 sowwakeup_locked(so2); 1002 UNP_PCB_UNLOCK(unp); 1003 return (0); 1004 } 1005 1006 static int 1007 connect_internal(struct socket *so, struct sockaddr *nam, struct thread *td) 1008 { 1009 int error; 1010 struct unpcb *unp; 1011 1012 unp = so->so_pcb; 1013 if (unp->unp_conn != NULL) 1014 return (EISCONN); 1015 error = unp_connect(so, nam, td); 1016 if (error) 1017 return (error); 1018 UNP_PCB_LOCK(unp); 1019 if (unp->unp_conn == NULL) { 1020 UNP_PCB_UNLOCK(unp); 1021 if (error == 0) 1022 error = ENOTCONN; 1023 } 1024 return (error); 1025 } 1026 1027 1028 static int 1029 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 1030 struct mbuf *control, struct thread *td) 1031 { 1032 struct unpcb *unp, *unp2; 1033 struct socket *so2; 1034 u_int mbcnt, sbcc; 1035 int freed, error; 1036 1037 unp = sotounpcb(so); 1038 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 1039 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 1040 so->so_type == SOCK_SEQPACKET, 1041 ("%s: socktype %d", __func__, so->so_type)); 1042 1043 freed = error = 0; 1044 if (flags & PRUS_OOB) { 1045 error = EOPNOTSUPP; 1046 goto release; 1047 } 1048 if (control != NULL && (error = unp_internalize(&control, td))) 1049 goto release; 1050 1051 unp2 = NULL; 1052 switch (so->so_type) { 1053 case SOCK_DGRAM: 1054 { 1055 const struct sockaddr *from; 1056 1057 if (nam != NULL) { 1058 /* 1059 * We return with UNP_PCB_LOCK_HELD so we know that 1060 * the reference is live if the pointer is valid. 1061 */ 1062 if ((error = connect_internal(so, nam, td))) 1063 break; 1064 MPASS(unp->unp_conn != NULL); 1065 unp2 = unp->unp_conn; 1066 } else { 1067 UNP_PCB_LOCK(unp); 1068 1069 /* 1070 * Because connect() and send() are non-atomic in a sendto() 1071 * with a target address, it's possible that the socket will 1072 * have disconnected before the send() can run. In that case 1073 * return the slightly counter-intuitive but otherwise 1074 * correct error that the socket is not connected. 1075 */ 1076 if ((unp2 = unp->unp_conn) == NULL) { 1077 UNP_PCB_UNLOCK(unp); 1078 error = ENOTCONN; 1079 break; 1080 } 1081 } 1082 if (__predict_false(unp == unp2)) { 1083 if (unp->unp_socket == NULL) { 1084 error = ENOTCONN; 1085 break; 1086 } 1087 goto connect_self; 1088 } 1089 unp_pcb_owned_lock2(unp, unp2, freed); 1090 if (__predict_false(freed)) { 1091 UNP_PCB_UNLOCK(unp); 1092 error = ENOTCONN; 1093 break; 1094 } 1095 /* 1096 * The socket referencing unp2 may have been closed 1097 * or unp may have been disconnected if the unp lock 1098 * was dropped to acquire unp2. 1099 */ 1100 if (__predict_false(unp->unp_conn == NULL) || 1101 unp2->unp_socket == NULL) { 1102 UNP_PCB_UNLOCK(unp); 1103 if (unp_pcb_rele(unp2) == 0) 1104 UNP_PCB_UNLOCK(unp2); 1105 error = ENOTCONN; 1106 break; 1107 } 1108 connect_self: 1109 if (unp2->unp_flags & UNP_WANTCRED) 1110 control = unp_addsockcred(td, control); 1111 if (unp->unp_addr != NULL) 1112 from = (struct sockaddr *)unp->unp_addr; 1113 else 1114 from = &sun_noname; 1115 so2 = unp2->unp_socket; 1116 SOCKBUF_LOCK(&so2->so_rcv); 1117 if (sbappendaddr_locked(&so2->so_rcv, from, m, 1118 control)) { 1119 sorwakeup_locked(so2); 1120 m = NULL; 1121 control = NULL; 1122 } else { 1123 SOCKBUF_UNLOCK(&so2->so_rcv); 1124 error = ENOBUFS; 1125 } 1126 if (nam != NULL) 1127 unp_disconnect(unp, unp2); 1128 if (__predict_true(unp != unp2)) 1129 UNP_PCB_UNLOCK(unp2); 1130 UNP_PCB_UNLOCK(unp); 1131 break; 1132 } 1133 1134 case SOCK_SEQPACKET: 1135 case SOCK_STREAM: 1136 if ((so->so_state & SS_ISCONNECTED) == 0) { 1137 if (nam != NULL) { 1138 if ((error = connect_internal(so, nam, td))) 1139 break; 1140 } else { 1141 error = ENOTCONN; 1142 break; 1143 } 1144 } else if ((unp2 = unp->unp_conn) == NULL) { 1145 error = ENOTCONN; 1146 break; 1147 } else if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 1148 error = EPIPE; 1149 break; 1150 } else { 1151 UNP_PCB_LOCK(unp); 1152 if ((unp2 = unp->unp_conn) == NULL) { 1153 UNP_PCB_UNLOCK(unp); 1154 error = ENOTCONN; 1155 break; 1156 } 1157 } 1158 unp_pcb_owned_lock2(unp, unp2, freed); 1159 UNP_PCB_UNLOCK(unp); 1160 if (__predict_false(freed)) { 1161 error = ENOTCONN; 1162 break; 1163 } 1164 if ((so2 = unp2->unp_socket) == NULL) { 1165 UNP_PCB_UNLOCK(unp2); 1166 error = ENOTCONN; 1167 break; 1168 } 1169 SOCKBUF_LOCK(&so2->so_rcv); 1170 if (unp2->unp_flags & UNP_WANTCRED) { 1171 /* 1172 * Credentials are passed only once on SOCK_STREAM 1173 * and SOCK_SEQPACKET. 1174 */ 1175 unp2->unp_flags &= ~UNP_WANTCRED; 1176 control = unp_addsockcred(td, control); 1177 } 1178 1179 /* 1180 * Send to paired receive port and wake up readers. Don't 1181 * check for space available in the receive buffer if we're 1182 * attaching ancillary data; Unix domain sockets only check 1183 * for space in the sending sockbuf, and that check is 1184 * performed one level up the stack. At that level we cannot 1185 * precisely account for the amount of buffer space used 1186 * (e.g., because control messages are not yet internalized). 1187 */ 1188 switch (so->so_type) { 1189 case SOCK_STREAM: 1190 if (control != NULL) { 1191 sbappendcontrol_locked(&so2->so_rcv, m, 1192 control); 1193 control = NULL; 1194 } else 1195 sbappend_locked(&so2->so_rcv, m, flags); 1196 break; 1197 1198 case SOCK_SEQPACKET: { 1199 const struct sockaddr *from; 1200 1201 from = &sun_noname; 1202 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 1203 from, m, control)) 1204 control = NULL; 1205 break; 1206 } 1207 } 1208 1209 mbcnt = so2->so_rcv.sb_mbcnt; 1210 sbcc = sbavail(&so2->so_rcv); 1211 if (sbcc) 1212 sorwakeup_locked(so2); 1213 else 1214 SOCKBUF_UNLOCK(&so2->so_rcv); 1215 1216 /* 1217 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1218 * it would be possible for uipc_rcvd to be called at this 1219 * point, drain the receiving sockbuf, clear SB_STOP, and then 1220 * we would set SB_STOP below. That could lead to an empty 1221 * sockbuf having SB_STOP set 1222 */ 1223 SOCKBUF_LOCK(&so->so_snd); 1224 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1225 so->so_snd.sb_flags |= SB_STOP; 1226 SOCKBUF_UNLOCK(&so->so_snd); 1227 UNP_PCB_UNLOCK(unp2); 1228 m = NULL; 1229 break; 1230 } 1231 1232 /* 1233 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1234 */ 1235 if (flags & PRUS_EOF) { 1236 UNP_PCB_LOCK(unp); 1237 socantsendmore(so); 1238 unp_shutdown(unp); 1239 UNP_PCB_UNLOCK(unp); 1240 } 1241 if (control != NULL && error != 0) 1242 unp_dispose_mbuf(control); 1243 1244 release: 1245 if (control != NULL) 1246 m_freem(control); 1247 /* 1248 * In case of PRUS_NOTREADY, uipc_ready() is responsible 1249 * for freeing memory. 1250 */ 1251 if (m != NULL && (flags & PRUS_NOTREADY) == 0) 1252 m_freem(m); 1253 return (error); 1254 } 1255 1256 static int 1257 uipc_ready(struct socket *so, struct mbuf *m, int count) 1258 { 1259 struct unpcb *unp, *unp2; 1260 struct socket *so2; 1261 int error; 1262 1263 unp = sotounpcb(so); 1264 1265 UNP_PCB_LOCK(unp); 1266 if ((unp2 = unp->unp_conn) == NULL) { 1267 UNP_PCB_UNLOCK(unp); 1268 goto error; 1269 } 1270 if (unp != unp2) { 1271 if (UNP_PCB_TRYLOCK(unp2) == 0) { 1272 unp_pcb_hold(unp2); 1273 UNP_PCB_UNLOCK(unp); 1274 UNP_PCB_LOCK(unp2); 1275 if (unp_pcb_rele(unp2)) 1276 goto error; 1277 } else 1278 UNP_PCB_UNLOCK(unp); 1279 } 1280 so2 = unp2->unp_socket; 1281 1282 SOCKBUF_LOCK(&so2->so_rcv); 1283 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1284 sorwakeup_locked(so2); 1285 else 1286 SOCKBUF_UNLOCK(&so2->so_rcv); 1287 1288 UNP_PCB_UNLOCK(unp2); 1289 1290 return (error); 1291 error: 1292 for (int i = 0; i < count; i++) 1293 m = m_free(m); 1294 return (ECONNRESET); 1295 } 1296 1297 static int 1298 uipc_sense(struct socket *so, struct stat *sb) 1299 { 1300 struct unpcb *unp; 1301 1302 unp = sotounpcb(so); 1303 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1304 1305 sb->st_blksize = so->so_snd.sb_hiwat; 1306 sb->st_dev = NODEV; 1307 sb->st_ino = unp->unp_ino; 1308 return (0); 1309 } 1310 1311 static int 1312 uipc_shutdown(struct socket *so) 1313 { 1314 struct unpcb *unp; 1315 1316 unp = sotounpcb(so); 1317 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1318 1319 UNP_PCB_LOCK(unp); 1320 socantsendmore(so); 1321 unp_shutdown(unp); 1322 UNP_PCB_UNLOCK(unp); 1323 return (0); 1324 } 1325 1326 static int 1327 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1328 { 1329 struct unpcb *unp; 1330 const struct sockaddr *sa; 1331 1332 unp = sotounpcb(so); 1333 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1334 1335 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1336 UNP_PCB_LOCK(unp); 1337 if (unp->unp_addr != NULL) 1338 sa = (struct sockaddr *) unp->unp_addr; 1339 else 1340 sa = &sun_noname; 1341 bcopy(sa, *nam, sa->sa_len); 1342 UNP_PCB_UNLOCK(unp); 1343 return (0); 1344 } 1345 1346 static struct pr_usrreqs uipc_usrreqs_dgram = { 1347 .pru_abort = uipc_abort, 1348 .pru_accept = uipc_accept, 1349 .pru_attach = uipc_attach, 1350 .pru_bind = uipc_bind, 1351 .pru_bindat = uipc_bindat, 1352 .pru_connect = uipc_connect, 1353 .pru_connectat = uipc_connectat, 1354 .pru_connect2 = uipc_connect2, 1355 .pru_detach = uipc_detach, 1356 .pru_disconnect = uipc_disconnect, 1357 .pru_listen = uipc_listen, 1358 .pru_peeraddr = uipc_peeraddr, 1359 .pru_rcvd = uipc_rcvd, 1360 .pru_send = uipc_send, 1361 .pru_sense = uipc_sense, 1362 .pru_shutdown = uipc_shutdown, 1363 .pru_sockaddr = uipc_sockaddr, 1364 .pru_soreceive = soreceive_dgram, 1365 .pru_close = uipc_close, 1366 }; 1367 1368 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1369 .pru_abort = uipc_abort, 1370 .pru_accept = uipc_accept, 1371 .pru_attach = uipc_attach, 1372 .pru_bind = uipc_bind, 1373 .pru_bindat = uipc_bindat, 1374 .pru_connect = uipc_connect, 1375 .pru_connectat = uipc_connectat, 1376 .pru_connect2 = uipc_connect2, 1377 .pru_detach = uipc_detach, 1378 .pru_disconnect = uipc_disconnect, 1379 .pru_listen = uipc_listen, 1380 .pru_peeraddr = uipc_peeraddr, 1381 .pru_rcvd = uipc_rcvd, 1382 .pru_send = uipc_send, 1383 .pru_sense = uipc_sense, 1384 .pru_shutdown = uipc_shutdown, 1385 .pru_sockaddr = uipc_sockaddr, 1386 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1387 .pru_close = uipc_close, 1388 }; 1389 1390 static struct pr_usrreqs uipc_usrreqs_stream = { 1391 .pru_abort = uipc_abort, 1392 .pru_accept = uipc_accept, 1393 .pru_attach = uipc_attach, 1394 .pru_bind = uipc_bind, 1395 .pru_bindat = uipc_bindat, 1396 .pru_connect = uipc_connect, 1397 .pru_connectat = uipc_connectat, 1398 .pru_connect2 = uipc_connect2, 1399 .pru_detach = uipc_detach, 1400 .pru_disconnect = uipc_disconnect, 1401 .pru_listen = uipc_listen, 1402 .pru_peeraddr = uipc_peeraddr, 1403 .pru_rcvd = uipc_rcvd, 1404 .pru_send = uipc_send, 1405 .pru_ready = uipc_ready, 1406 .pru_sense = uipc_sense, 1407 .pru_shutdown = uipc_shutdown, 1408 .pru_sockaddr = uipc_sockaddr, 1409 .pru_soreceive = soreceive_generic, 1410 .pru_close = uipc_close, 1411 }; 1412 1413 static int 1414 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1415 { 1416 struct unpcb *unp; 1417 struct xucred xu; 1418 int error, optval; 1419 1420 if (sopt->sopt_level != 0) 1421 return (EINVAL); 1422 1423 unp = sotounpcb(so); 1424 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1425 error = 0; 1426 switch (sopt->sopt_dir) { 1427 case SOPT_GET: 1428 switch (sopt->sopt_name) { 1429 case LOCAL_PEERCRED: 1430 UNP_PCB_LOCK(unp); 1431 if (unp->unp_flags & UNP_HAVEPC) 1432 xu = unp->unp_peercred; 1433 else { 1434 if (so->so_type == SOCK_STREAM) 1435 error = ENOTCONN; 1436 else 1437 error = EINVAL; 1438 } 1439 UNP_PCB_UNLOCK(unp); 1440 if (error == 0) 1441 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1442 break; 1443 1444 case LOCAL_CREDS: 1445 /* Unlocked read. */ 1446 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1447 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1448 break; 1449 1450 case LOCAL_CONNWAIT: 1451 /* Unlocked read. */ 1452 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1453 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1454 break; 1455 1456 default: 1457 error = EOPNOTSUPP; 1458 break; 1459 } 1460 break; 1461 1462 case SOPT_SET: 1463 switch (sopt->sopt_name) { 1464 case LOCAL_CREDS: 1465 case LOCAL_CONNWAIT: 1466 error = sooptcopyin(sopt, &optval, sizeof(optval), 1467 sizeof(optval)); 1468 if (error) 1469 break; 1470 1471 #define OPTSET(bit) do { \ 1472 UNP_PCB_LOCK(unp); \ 1473 if (optval) \ 1474 unp->unp_flags |= bit; \ 1475 else \ 1476 unp->unp_flags &= ~bit; \ 1477 UNP_PCB_UNLOCK(unp); \ 1478 } while (0) 1479 1480 switch (sopt->sopt_name) { 1481 case LOCAL_CREDS: 1482 OPTSET(UNP_WANTCRED); 1483 break; 1484 1485 case LOCAL_CONNWAIT: 1486 OPTSET(UNP_CONNWAIT); 1487 break; 1488 1489 default: 1490 break; 1491 } 1492 break; 1493 #undef OPTSET 1494 default: 1495 error = ENOPROTOOPT; 1496 break; 1497 } 1498 break; 1499 1500 default: 1501 error = EOPNOTSUPP; 1502 break; 1503 } 1504 return (error); 1505 } 1506 1507 static int 1508 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1509 { 1510 1511 return (unp_connectat(AT_FDCWD, so, nam, td)); 1512 } 1513 1514 static int 1515 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1516 struct thread *td) 1517 { 1518 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1519 struct vnode *vp; 1520 struct socket *so2; 1521 struct unpcb *unp, *unp2, *unp3; 1522 struct nameidata nd; 1523 char buf[SOCK_MAXADDRLEN]; 1524 struct sockaddr *sa; 1525 cap_rights_t rights; 1526 int error, len, freed; 1527 struct mtx *vplock; 1528 1529 if (nam->sa_family != AF_UNIX) 1530 return (EAFNOSUPPORT); 1531 if (nam->sa_len > sizeof(struct sockaddr_un)) 1532 return (EINVAL); 1533 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1534 if (len <= 0) 1535 return (EINVAL); 1536 bcopy(soun->sun_path, buf, len); 1537 buf[len] = 0; 1538 1539 unp = sotounpcb(so); 1540 UNP_PCB_LOCK(unp); 1541 if (unp->unp_flags & UNP_CONNECTING) { 1542 UNP_PCB_UNLOCK(unp); 1543 return (EALREADY); 1544 } 1545 unp->unp_flags |= UNP_CONNECTING; 1546 UNP_PCB_UNLOCK(unp); 1547 1548 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1549 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1550 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td); 1551 error = namei(&nd); 1552 if (error) 1553 vp = NULL; 1554 else 1555 vp = nd.ni_vp; 1556 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1557 NDFREE(&nd, NDF_ONLY_PNBUF); 1558 if (error) 1559 goto bad; 1560 1561 if (vp->v_type != VSOCK) { 1562 error = ENOTSOCK; 1563 goto bad; 1564 } 1565 #ifdef MAC 1566 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1567 if (error) 1568 goto bad; 1569 #endif 1570 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1571 if (error) 1572 goto bad; 1573 1574 unp = sotounpcb(so); 1575 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1576 1577 vplock = mtx_pool_find(mtxpool_sleep, vp); 1578 mtx_lock(vplock); 1579 VOP_UNP_CONNECT(vp, &unp2); 1580 if (unp2 == NULL) { 1581 error = ECONNREFUSED; 1582 goto bad2; 1583 } 1584 so2 = unp2->unp_socket; 1585 if (so->so_type != so2->so_type) { 1586 error = EPROTOTYPE; 1587 goto bad2; 1588 } 1589 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1590 if (so2->so_options & SO_ACCEPTCONN) { 1591 CURVNET_SET(so2->so_vnet); 1592 so2 = sonewconn(so2, 0); 1593 CURVNET_RESTORE(); 1594 } else 1595 so2 = NULL; 1596 if (so2 == NULL) { 1597 error = ECONNREFUSED; 1598 goto bad2; 1599 } 1600 unp3 = sotounpcb(so2); 1601 unp_pcb_lock2(unp2, unp3); 1602 if (unp2->unp_addr != NULL) { 1603 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1604 unp3->unp_addr = (struct sockaddr_un *) sa; 1605 sa = NULL; 1606 } 1607 1608 unp_copy_peercred(td, unp3, unp, unp2); 1609 1610 UNP_PCB_UNLOCK(unp2); 1611 unp2 = unp3; 1612 unp_pcb_owned_lock2(unp2, unp, freed); 1613 if (__predict_false(freed)) { 1614 UNP_PCB_UNLOCK(unp2); 1615 error = ECONNREFUSED; 1616 goto bad2; 1617 } 1618 #ifdef MAC 1619 mac_socketpeer_set_from_socket(so, so2); 1620 mac_socketpeer_set_from_socket(so2, so); 1621 #endif 1622 } else { 1623 if (unp == unp2) 1624 UNP_PCB_LOCK(unp); 1625 else 1626 unp_pcb_lock2(unp, unp2); 1627 } 1628 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1629 sotounpcb(so2) == unp2, 1630 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1631 error = unp_connect2(so, so2, PRU_CONNECT); 1632 if (unp != unp2) 1633 UNP_PCB_UNLOCK(unp2); 1634 UNP_PCB_UNLOCK(unp); 1635 bad2: 1636 mtx_unlock(vplock); 1637 bad: 1638 if (vp != NULL) { 1639 vput(vp); 1640 } 1641 free(sa, M_SONAME); 1642 UNP_PCB_LOCK(unp); 1643 unp->unp_flags &= ~UNP_CONNECTING; 1644 UNP_PCB_UNLOCK(unp); 1645 return (error); 1646 } 1647 1648 /* 1649 * Set socket peer credentials at connection time. 1650 * 1651 * The client's PCB credentials are copied from its process structure. The 1652 * server's PCB credentials are copied from the socket on which it called 1653 * listen(2). uipc_listen cached that process's credentials at the time. 1654 */ 1655 void 1656 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 1657 struct unpcb *server_unp, struct unpcb *listen_unp) 1658 { 1659 cru2x(td->td_ucred, &client_unp->unp_peercred); 1660 client_unp->unp_flags |= UNP_HAVEPC; 1661 1662 memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred, 1663 sizeof(server_unp->unp_peercred)); 1664 server_unp->unp_flags |= UNP_HAVEPC; 1665 if (listen_unp->unp_flags & UNP_WANTCRED) 1666 client_unp->unp_flags |= UNP_WANTCRED; 1667 } 1668 1669 static int 1670 unp_connect2(struct socket *so, struct socket *so2, int req) 1671 { 1672 struct unpcb *unp; 1673 struct unpcb *unp2; 1674 1675 unp = sotounpcb(so); 1676 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1677 unp2 = sotounpcb(so2); 1678 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1679 1680 UNP_PCB_LOCK_ASSERT(unp); 1681 UNP_PCB_LOCK_ASSERT(unp2); 1682 1683 if (so2->so_type != so->so_type) 1684 return (EPROTOTYPE); 1685 unp2->unp_flags &= ~UNP_NASCENT; 1686 unp->unp_conn = unp2; 1687 unp_pcb_hold(unp2); 1688 unp_pcb_hold(unp); 1689 switch (so->so_type) { 1690 case SOCK_DGRAM: 1691 UNP_REF_LIST_LOCK(); 1692 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1693 UNP_REF_LIST_UNLOCK(); 1694 soisconnected(so); 1695 break; 1696 1697 case SOCK_STREAM: 1698 case SOCK_SEQPACKET: 1699 unp2->unp_conn = unp; 1700 if (req == PRU_CONNECT && 1701 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1702 soisconnecting(so); 1703 else 1704 soisconnected(so); 1705 soisconnected(so2); 1706 break; 1707 1708 default: 1709 panic("unp_connect2"); 1710 } 1711 return (0); 1712 } 1713 1714 static void 1715 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1716 { 1717 struct socket *so, *so2; 1718 int freed __unused; 1719 1720 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1721 1722 UNP_PCB_LOCK_ASSERT(unp); 1723 UNP_PCB_LOCK_ASSERT(unp2); 1724 1725 if (unp->unp_conn == NULL && unp2->unp_conn == NULL) 1726 return; 1727 1728 MPASS(unp->unp_conn == unp2); 1729 unp->unp_conn = NULL; 1730 so = unp->unp_socket; 1731 so2 = unp2->unp_socket; 1732 switch (unp->unp_socket->so_type) { 1733 case SOCK_DGRAM: 1734 UNP_REF_LIST_LOCK(); 1735 LIST_REMOVE(unp, unp_reflink); 1736 UNP_REF_LIST_UNLOCK(); 1737 if (so) { 1738 SOCK_LOCK(so); 1739 so->so_state &= ~SS_ISCONNECTED; 1740 SOCK_UNLOCK(so); 1741 } 1742 break; 1743 1744 case SOCK_STREAM: 1745 case SOCK_SEQPACKET: 1746 if (so) 1747 soisdisconnected(so); 1748 MPASS(unp2->unp_conn == unp); 1749 unp2->unp_conn = NULL; 1750 if (so2) 1751 soisdisconnected(so2); 1752 break; 1753 } 1754 freed = unp_pcb_rele(unp); 1755 MPASS(freed == 0); 1756 freed = unp_pcb_rele(unp2); 1757 MPASS(freed == 0); 1758 } 1759 1760 /* 1761 * unp_pcblist() walks the global list of struct unpcb's to generate a 1762 * pointer list, bumping the refcount on each unpcb. It then copies them out 1763 * sequentially, validating the generation number on each to see if it has 1764 * been detached. All of this is necessary because copyout() may sleep on 1765 * disk I/O. 1766 */ 1767 static int 1768 unp_pcblist(SYSCTL_HANDLER_ARGS) 1769 { 1770 struct unpcb *unp, **unp_list; 1771 unp_gen_t gencnt; 1772 struct xunpgen *xug; 1773 struct unp_head *head; 1774 struct xunpcb *xu; 1775 u_int i; 1776 int error, freeunp, n; 1777 1778 switch ((intptr_t)arg1) { 1779 case SOCK_STREAM: 1780 head = &unp_shead; 1781 break; 1782 1783 case SOCK_DGRAM: 1784 head = &unp_dhead; 1785 break; 1786 1787 case SOCK_SEQPACKET: 1788 head = &unp_sphead; 1789 break; 1790 1791 default: 1792 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1793 } 1794 1795 /* 1796 * The process of preparing the PCB list is too time-consuming and 1797 * resource-intensive to repeat twice on every request. 1798 */ 1799 if (req->oldptr == NULL) { 1800 n = unp_count; 1801 req->oldidx = 2 * (sizeof *xug) 1802 + (n + n/8) * sizeof(struct xunpcb); 1803 return (0); 1804 } 1805 1806 if (req->newptr != NULL) 1807 return (EPERM); 1808 1809 /* 1810 * OK, now we're committed to doing something. 1811 */ 1812 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK | M_ZERO); 1813 UNP_LINK_RLOCK(); 1814 gencnt = unp_gencnt; 1815 n = unp_count; 1816 UNP_LINK_RUNLOCK(); 1817 1818 xug->xug_len = sizeof *xug; 1819 xug->xug_count = n; 1820 xug->xug_gen = gencnt; 1821 xug->xug_sogen = so_gencnt; 1822 error = SYSCTL_OUT(req, xug, sizeof *xug); 1823 if (error) { 1824 free(xug, M_TEMP); 1825 return (error); 1826 } 1827 1828 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1829 1830 UNP_LINK_RLOCK(); 1831 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1832 unp = LIST_NEXT(unp, unp_link)) { 1833 UNP_PCB_LOCK(unp); 1834 if (unp->unp_gencnt <= gencnt) { 1835 if (cr_cansee(req->td->td_ucred, 1836 unp->unp_socket->so_cred)) { 1837 UNP_PCB_UNLOCK(unp); 1838 continue; 1839 } 1840 unp_list[i++] = unp; 1841 unp_pcb_hold(unp); 1842 } 1843 UNP_PCB_UNLOCK(unp); 1844 } 1845 UNP_LINK_RUNLOCK(); 1846 n = i; /* In case we lost some during malloc. */ 1847 1848 error = 0; 1849 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1850 for (i = 0; i < n; i++) { 1851 unp = unp_list[i]; 1852 UNP_PCB_LOCK(unp); 1853 freeunp = unp_pcb_rele(unp); 1854 1855 if (freeunp == 0 && unp->unp_gencnt <= gencnt) { 1856 xu->xu_len = sizeof *xu; 1857 xu->xu_unpp = (uintptr_t)unp; 1858 /* 1859 * XXX - need more locking here to protect against 1860 * connect/disconnect races for SMP. 1861 */ 1862 if (unp->unp_addr != NULL) 1863 bcopy(unp->unp_addr, &xu->xu_addr, 1864 unp->unp_addr->sun_len); 1865 else 1866 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1867 if (unp->unp_conn != NULL && 1868 unp->unp_conn->unp_addr != NULL) 1869 bcopy(unp->unp_conn->unp_addr, 1870 &xu->xu_caddr, 1871 unp->unp_conn->unp_addr->sun_len); 1872 else 1873 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1874 xu->unp_vnode = (uintptr_t)unp->unp_vnode; 1875 xu->unp_conn = (uintptr_t)unp->unp_conn; 1876 xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs); 1877 xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink); 1878 xu->unp_gencnt = unp->unp_gencnt; 1879 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1880 UNP_PCB_UNLOCK(unp); 1881 error = SYSCTL_OUT(req, xu, sizeof *xu); 1882 } else if (freeunp == 0) 1883 UNP_PCB_UNLOCK(unp); 1884 } 1885 free(xu, M_TEMP); 1886 if (!error) { 1887 /* 1888 * Give the user an updated idea of our state. If the 1889 * generation differs from what we told her before, she knows 1890 * that something happened while we were processing this 1891 * request, and it might be necessary to retry. 1892 */ 1893 xug->xug_gen = unp_gencnt; 1894 xug->xug_sogen = so_gencnt; 1895 xug->xug_count = unp_count; 1896 error = SYSCTL_OUT(req, xug, sizeof *xug); 1897 } 1898 free(unp_list, M_TEMP); 1899 free(xug, M_TEMP); 1900 return (error); 1901 } 1902 1903 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1904 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1905 "List of active local datagram sockets"); 1906 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1907 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1908 "List of active local stream sockets"); 1909 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1910 CTLTYPE_OPAQUE | CTLFLAG_RD, 1911 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1912 "List of active local seqpacket sockets"); 1913 1914 static void 1915 unp_shutdown(struct unpcb *unp) 1916 { 1917 struct unpcb *unp2; 1918 struct socket *so; 1919 1920 UNP_PCB_LOCK_ASSERT(unp); 1921 1922 unp2 = unp->unp_conn; 1923 if ((unp->unp_socket->so_type == SOCK_STREAM || 1924 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1925 so = unp2->unp_socket; 1926 if (so != NULL) 1927 socantrcvmore(so); 1928 } 1929 } 1930 1931 static void 1932 unp_drop(struct unpcb *unp) 1933 { 1934 struct socket *so = unp->unp_socket; 1935 struct unpcb *unp2; 1936 int freed; 1937 1938 /* 1939 * Regardless of whether the socket's peer dropped the connection 1940 * with this socket by aborting or disconnecting, POSIX requires 1941 * that ECONNRESET is returned. 1942 */ 1943 /* acquire a reference so that unp isn't freed from underneath us */ 1944 1945 UNP_PCB_LOCK(unp); 1946 if (so) 1947 so->so_error = ECONNRESET; 1948 unp2 = unp->unp_conn; 1949 if (unp2 == unp) { 1950 unp_disconnect(unp, unp2); 1951 } else if (unp2 != NULL) { 1952 unp_pcb_hold(unp2); 1953 unp_pcb_owned_lock2(unp, unp2, freed); 1954 unp_disconnect(unp, unp2); 1955 if (unp_pcb_rele(unp2) == 0) 1956 UNP_PCB_UNLOCK(unp2); 1957 } 1958 if (unp_pcb_rele(unp) == 0) 1959 UNP_PCB_UNLOCK(unp); 1960 } 1961 1962 static void 1963 unp_freerights(struct filedescent **fdep, int fdcount) 1964 { 1965 struct file *fp; 1966 int i; 1967 1968 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1969 1970 for (i = 0; i < fdcount; i++) { 1971 fp = fdep[i]->fde_file; 1972 filecaps_free(&fdep[i]->fde_caps); 1973 unp_discard(fp); 1974 } 1975 free(fdep[0], M_FILECAPS); 1976 } 1977 1978 static int 1979 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 1980 { 1981 struct thread *td = curthread; /* XXX */ 1982 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1983 int i; 1984 int *fdp; 1985 struct filedesc *fdesc = td->td_proc->p_fd; 1986 struct filedescent **fdep; 1987 void *data; 1988 socklen_t clen = control->m_len, datalen; 1989 int error, newfds; 1990 u_int newlen; 1991 1992 UNP_LINK_UNLOCK_ASSERT(); 1993 1994 error = 0; 1995 if (controlp != NULL) /* controlp == NULL => free control messages */ 1996 *controlp = NULL; 1997 while (cm != NULL) { 1998 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1999 error = EINVAL; 2000 break; 2001 } 2002 data = CMSG_DATA(cm); 2003 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2004 if (cm->cmsg_level == SOL_SOCKET 2005 && cm->cmsg_type == SCM_RIGHTS) { 2006 newfds = datalen / sizeof(*fdep); 2007 if (newfds == 0) 2008 goto next; 2009 fdep = data; 2010 2011 /* If we're not outputting the descriptors free them. */ 2012 if (error || controlp == NULL) { 2013 unp_freerights(fdep, newfds); 2014 goto next; 2015 } 2016 FILEDESC_XLOCK(fdesc); 2017 2018 /* 2019 * Now change each pointer to an fd in the global 2020 * table to an integer that is the index to the local 2021 * fd table entry that we set up to point to the 2022 * global one we are transferring. 2023 */ 2024 newlen = newfds * sizeof(int); 2025 *controlp = sbcreatecontrol(NULL, newlen, 2026 SCM_RIGHTS, SOL_SOCKET); 2027 if (*controlp == NULL) { 2028 FILEDESC_XUNLOCK(fdesc); 2029 error = E2BIG; 2030 unp_freerights(fdep, newfds); 2031 goto next; 2032 } 2033 2034 fdp = (int *) 2035 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2036 if (fdallocn(td, 0, fdp, newfds) != 0) { 2037 FILEDESC_XUNLOCK(fdesc); 2038 error = EMSGSIZE; 2039 unp_freerights(fdep, newfds); 2040 m_freem(*controlp); 2041 *controlp = NULL; 2042 goto next; 2043 } 2044 for (i = 0; i < newfds; i++, fdp++) { 2045 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2046 (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0, 2047 &fdep[i]->fde_caps); 2048 unp_externalize_fp(fdep[i]->fde_file); 2049 } 2050 2051 /* 2052 * The new type indicates that the mbuf data refers to 2053 * kernel resources that may need to be released before 2054 * the mbuf is freed. 2055 */ 2056 m_chtype(*controlp, MT_EXTCONTROL); 2057 FILEDESC_XUNLOCK(fdesc); 2058 free(fdep[0], M_FILECAPS); 2059 } else { 2060 /* We can just copy anything else across. */ 2061 if (error || controlp == NULL) 2062 goto next; 2063 *controlp = sbcreatecontrol(NULL, datalen, 2064 cm->cmsg_type, cm->cmsg_level); 2065 if (*controlp == NULL) { 2066 error = ENOBUFS; 2067 goto next; 2068 } 2069 bcopy(data, 2070 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2071 datalen); 2072 } 2073 controlp = &(*controlp)->m_next; 2074 2075 next: 2076 if (CMSG_SPACE(datalen) < clen) { 2077 clen -= CMSG_SPACE(datalen); 2078 cm = (struct cmsghdr *) 2079 ((caddr_t)cm + CMSG_SPACE(datalen)); 2080 } else { 2081 clen = 0; 2082 cm = NULL; 2083 } 2084 } 2085 2086 m_freem(control); 2087 return (error); 2088 } 2089 2090 static void 2091 unp_zone_change(void *tag) 2092 { 2093 2094 uma_zone_set_max(unp_zone, maxsockets); 2095 } 2096 2097 static void 2098 unp_init(void) 2099 { 2100 2101 #ifdef VIMAGE 2102 if (!IS_DEFAULT_VNET(curvnet)) 2103 return; 2104 #endif 2105 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 2106 NULL, NULL, UMA_ALIGN_CACHE, 0); 2107 if (unp_zone == NULL) 2108 panic("unp_init"); 2109 uma_zone_set_max(unp_zone, maxsockets); 2110 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2111 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2112 NULL, EVENTHANDLER_PRI_ANY); 2113 LIST_INIT(&unp_dhead); 2114 LIST_INIT(&unp_shead); 2115 LIST_INIT(&unp_sphead); 2116 SLIST_INIT(&unp_defers); 2117 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2118 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2119 UNP_LINK_LOCK_INIT(); 2120 UNP_DEFERRED_LOCK_INIT(); 2121 } 2122 2123 static int 2124 unp_internalize(struct mbuf **controlp, struct thread *td) 2125 { 2126 struct mbuf *control = *controlp; 2127 struct proc *p = td->td_proc; 2128 struct filedesc *fdesc = p->p_fd; 2129 struct bintime *bt; 2130 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2131 struct cmsgcred *cmcred; 2132 struct filedescent *fde, **fdep, *fdev; 2133 struct file *fp; 2134 struct timeval *tv; 2135 struct timespec *ts; 2136 int i, *fdp; 2137 void *data; 2138 socklen_t clen = control->m_len, datalen; 2139 int error, oldfds; 2140 u_int newlen; 2141 2142 UNP_LINK_UNLOCK_ASSERT(); 2143 2144 error = 0; 2145 *controlp = NULL; 2146 while (cm != NULL) { 2147 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2148 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2149 error = EINVAL; 2150 goto out; 2151 } 2152 data = CMSG_DATA(cm); 2153 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2154 2155 switch (cm->cmsg_type) { 2156 /* 2157 * Fill in credential information. 2158 */ 2159 case SCM_CREDS: 2160 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2161 SCM_CREDS, SOL_SOCKET); 2162 if (*controlp == NULL) { 2163 error = ENOBUFS; 2164 goto out; 2165 } 2166 cmcred = (struct cmsgcred *) 2167 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2168 cmcred->cmcred_pid = p->p_pid; 2169 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2170 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2171 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2172 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2173 CMGROUP_MAX); 2174 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2175 cmcred->cmcred_groups[i] = 2176 td->td_ucred->cr_groups[i]; 2177 break; 2178 2179 case SCM_RIGHTS: 2180 oldfds = datalen / sizeof (int); 2181 if (oldfds == 0) 2182 break; 2183 /* 2184 * Check that all the FDs passed in refer to legal 2185 * files. If not, reject the entire operation. 2186 */ 2187 fdp = data; 2188 FILEDESC_SLOCK(fdesc); 2189 for (i = 0; i < oldfds; i++, fdp++) { 2190 fp = fget_locked(fdesc, *fdp); 2191 if (fp == NULL) { 2192 FILEDESC_SUNLOCK(fdesc); 2193 error = EBADF; 2194 goto out; 2195 } 2196 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2197 FILEDESC_SUNLOCK(fdesc); 2198 error = EOPNOTSUPP; 2199 goto out; 2200 } 2201 2202 } 2203 2204 /* 2205 * Now replace the integer FDs with pointers to the 2206 * file structure and capability rights. 2207 */ 2208 newlen = oldfds * sizeof(fdep[0]); 2209 *controlp = sbcreatecontrol(NULL, newlen, 2210 SCM_RIGHTS, SOL_SOCKET); 2211 if (*controlp == NULL) { 2212 FILEDESC_SUNLOCK(fdesc); 2213 error = E2BIG; 2214 goto out; 2215 } 2216 fdp = data; 2217 fdep = (struct filedescent **) 2218 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2219 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2220 M_WAITOK); 2221 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2222 fde = &fdesc->fd_ofiles[*fdp]; 2223 fdep[i] = fdev; 2224 fdep[i]->fde_file = fde->fde_file; 2225 filecaps_copy(&fde->fde_caps, 2226 &fdep[i]->fde_caps, true); 2227 unp_internalize_fp(fdep[i]->fde_file); 2228 } 2229 FILEDESC_SUNLOCK(fdesc); 2230 break; 2231 2232 case SCM_TIMESTAMP: 2233 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2234 SCM_TIMESTAMP, SOL_SOCKET); 2235 if (*controlp == NULL) { 2236 error = ENOBUFS; 2237 goto out; 2238 } 2239 tv = (struct timeval *) 2240 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2241 microtime(tv); 2242 break; 2243 2244 case SCM_BINTIME: 2245 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2246 SCM_BINTIME, SOL_SOCKET); 2247 if (*controlp == NULL) { 2248 error = ENOBUFS; 2249 goto out; 2250 } 2251 bt = (struct bintime *) 2252 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2253 bintime(bt); 2254 break; 2255 2256 case SCM_REALTIME: 2257 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2258 SCM_REALTIME, SOL_SOCKET); 2259 if (*controlp == NULL) { 2260 error = ENOBUFS; 2261 goto out; 2262 } 2263 ts = (struct timespec *) 2264 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2265 nanotime(ts); 2266 break; 2267 2268 case SCM_MONOTONIC: 2269 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2270 SCM_MONOTONIC, SOL_SOCKET); 2271 if (*controlp == NULL) { 2272 error = ENOBUFS; 2273 goto out; 2274 } 2275 ts = (struct timespec *) 2276 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2277 nanouptime(ts); 2278 break; 2279 2280 default: 2281 error = EINVAL; 2282 goto out; 2283 } 2284 2285 controlp = &(*controlp)->m_next; 2286 if (CMSG_SPACE(datalen) < clen) { 2287 clen -= CMSG_SPACE(datalen); 2288 cm = (struct cmsghdr *) 2289 ((caddr_t)cm + CMSG_SPACE(datalen)); 2290 } else { 2291 clen = 0; 2292 cm = NULL; 2293 } 2294 } 2295 2296 out: 2297 m_freem(control); 2298 return (error); 2299 } 2300 2301 static struct mbuf * 2302 unp_addsockcred(struct thread *td, struct mbuf *control) 2303 { 2304 struct mbuf *m, *n, *n_prev; 2305 struct sockcred *sc; 2306 const struct cmsghdr *cm; 2307 int ngroups; 2308 int i; 2309 2310 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2311 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 2312 if (m == NULL) 2313 return (control); 2314 2315 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 2316 sc->sc_uid = td->td_ucred->cr_ruid; 2317 sc->sc_euid = td->td_ucred->cr_uid; 2318 sc->sc_gid = td->td_ucred->cr_rgid; 2319 sc->sc_egid = td->td_ucred->cr_gid; 2320 sc->sc_ngroups = ngroups; 2321 for (i = 0; i < sc->sc_ngroups; i++) 2322 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2323 2324 /* 2325 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2326 * created SCM_CREDS control message (struct sockcred) has another 2327 * format. 2328 */ 2329 if (control != NULL) 2330 for (n = control, n_prev = NULL; n != NULL;) { 2331 cm = mtod(n, struct cmsghdr *); 2332 if (cm->cmsg_level == SOL_SOCKET && 2333 cm->cmsg_type == SCM_CREDS) { 2334 if (n_prev == NULL) 2335 control = n->m_next; 2336 else 2337 n_prev->m_next = n->m_next; 2338 n = m_free(n); 2339 } else { 2340 n_prev = n; 2341 n = n->m_next; 2342 } 2343 } 2344 2345 /* Prepend it to the head. */ 2346 m->m_next = control; 2347 return (m); 2348 } 2349 2350 static struct unpcb * 2351 fptounp(struct file *fp) 2352 { 2353 struct socket *so; 2354 2355 if (fp->f_type != DTYPE_SOCKET) 2356 return (NULL); 2357 if ((so = fp->f_data) == NULL) 2358 return (NULL); 2359 if (so->so_proto->pr_domain != &localdomain) 2360 return (NULL); 2361 return sotounpcb(so); 2362 } 2363 2364 static void 2365 unp_discard(struct file *fp) 2366 { 2367 struct unp_defer *dr; 2368 2369 if (unp_externalize_fp(fp)) { 2370 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2371 dr->ud_fp = fp; 2372 UNP_DEFERRED_LOCK(); 2373 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2374 UNP_DEFERRED_UNLOCK(); 2375 atomic_add_int(&unp_defers_count, 1); 2376 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2377 } else 2378 (void) closef(fp, (struct thread *)NULL); 2379 } 2380 2381 static void 2382 unp_process_defers(void *arg __unused, int pending) 2383 { 2384 struct unp_defer *dr; 2385 SLIST_HEAD(, unp_defer) drl; 2386 int count; 2387 2388 SLIST_INIT(&drl); 2389 for (;;) { 2390 UNP_DEFERRED_LOCK(); 2391 if (SLIST_FIRST(&unp_defers) == NULL) { 2392 UNP_DEFERRED_UNLOCK(); 2393 break; 2394 } 2395 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2396 UNP_DEFERRED_UNLOCK(); 2397 count = 0; 2398 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2399 SLIST_REMOVE_HEAD(&drl, ud_link); 2400 closef(dr->ud_fp, NULL); 2401 free(dr, M_TEMP); 2402 count++; 2403 } 2404 atomic_add_int(&unp_defers_count, -count); 2405 } 2406 } 2407 2408 static void 2409 unp_internalize_fp(struct file *fp) 2410 { 2411 struct unpcb *unp; 2412 2413 UNP_LINK_WLOCK(); 2414 if ((unp = fptounp(fp)) != NULL) { 2415 unp->unp_file = fp; 2416 unp->unp_msgcount++; 2417 } 2418 fhold(fp); 2419 unp_rights++; 2420 UNP_LINK_WUNLOCK(); 2421 } 2422 2423 static int 2424 unp_externalize_fp(struct file *fp) 2425 { 2426 struct unpcb *unp; 2427 int ret; 2428 2429 UNP_LINK_WLOCK(); 2430 if ((unp = fptounp(fp)) != NULL) { 2431 unp->unp_msgcount--; 2432 ret = 1; 2433 } else 2434 ret = 0; 2435 unp_rights--; 2436 UNP_LINK_WUNLOCK(); 2437 return (ret); 2438 } 2439 2440 /* 2441 * unp_defer indicates whether additional work has been defered for a future 2442 * pass through unp_gc(). It is thread local and does not require explicit 2443 * synchronization. 2444 */ 2445 static int unp_marked; 2446 static int unp_unreachable; 2447 2448 static void 2449 unp_accessable(struct filedescent **fdep, int fdcount) 2450 { 2451 struct unpcb *unp; 2452 struct file *fp; 2453 int i; 2454 2455 for (i = 0; i < fdcount; i++) { 2456 fp = fdep[i]->fde_file; 2457 if ((unp = fptounp(fp)) == NULL) 2458 continue; 2459 if (unp->unp_gcflag & UNPGC_REF) 2460 continue; 2461 unp->unp_gcflag &= ~UNPGC_DEAD; 2462 unp->unp_gcflag |= UNPGC_REF; 2463 unp_marked++; 2464 } 2465 } 2466 2467 static void 2468 unp_gc_process(struct unpcb *unp) 2469 { 2470 struct socket *so, *soa; 2471 struct file *fp; 2472 2473 /* Already processed. */ 2474 if (unp->unp_gcflag & UNPGC_SCANNED) 2475 return; 2476 fp = unp->unp_file; 2477 2478 /* 2479 * Check for a socket potentially in a cycle. It must be in a 2480 * queue as indicated by msgcount, and this must equal the file 2481 * reference count. Note that when msgcount is 0 the file is NULL. 2482 */ 2483 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2484 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2485 unp->unp_gcflag |= UNPGC_DEAD; 2486 unp_unreachable++; 2487 return; 2488 } 2489 2490 so = unp->unp_socket; 2491 SOCK_LOCK(so); 2492 if (SOLISTENING(so)) { 2493 /* 2494 * Mark all sockets in our accept queue. 2495 */ 2496 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2497 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2498 continue; 2499 SOCKBUF_LOCK(&soa->so_rcv); 2500 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2501 SOCKBUF_UNLOCK(&soa->so_rcv); 2502 } 2503 } else { 2504 /* 2505 * Mark all sockets we reference with RIGHTS. 2506 */ 2507 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2508 SOCKBUF_LOCK(&so->so_rcv); 2509 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2510 SOCKBUF_UNLOCK(&so->so_rcv); 2511 } 2512 } 2513 SOCK_UNLOCK(so); 2514 unp->unp_gcflag |= UNPGC_SCANNED; 2515 } 2516 2517 static int unp_recycled; 2518 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2519 "Number of unreachable sockets claimed by the garbage collector."); 2520 2521 static int unp_taskcount; 2522 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2523 "Number of times the garbage collector has run."); 2524 2525 static void 2526 unp_gc(__unused void *arg, int pending) 2527 { 2528 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2529 NULL }; 2530 struct unp_head **head; 2531 struct file *f, **unref; 2532 struct unpcb *unp; 2533 int i, total; 2534 2535 unp_taskcount++; 2536 UNP_LINK_RLOCK(); 2537 /* 2538 * First clear all gc flags from previous runs, apart from 2539 * UNPGC_IGNORE_RIGHTS. 2540 */ 2541 for (head = heads; *head != NULL; head++) 2542 LIST_FOREACH(unp, *head, unp_link) 2543 unp->unp_gcflag = 2544 (unp->unp_gcflag & UNPGC_IGNORE_RIGHTS); 2545 2546 /* 2547 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2548 * is reachable all of the sockets it references are reachable. 2549 * Stop the scan once we do a complete loop without discovering 2550 * a new reachable socket. 2551 */ 2552 do { 2553 unp_unreachable = 0; 2554 unp_marked = 0; 2555 for (head = heads; *head != NULL; head++) 2556 LIST_FOREACH(unp, *head, unp_link) 2557 unp_gc_process(unp); 2558 } while (unp_marked); 2559 UNP_LINK_RUNLOCK(); 2560 if (unp_unreachable == 0) 2561 return; 2562 2563 /* 2564 * Allocate space for a local list of dead unpcbs. 2565 */ 2566 unref = malloc(unp_unreachable * sizeof(struct file *), 2567 M_TEMP, M_WAITOK); 2568 2569 /* 2570 * Iterate looking for sockets which have been specifically marked 2571 * as as unreachable and store them locally. 2572 */ 2573 UNP_LINK_RLOCK(); 2574 for (total = 0, head = heads; *head != NULL; head++) 2575 LIST_FOREACH(unp, *head, unp_link) 2576 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2577 f = unp->unp_file; 2578 if (unp->unp_msgcount == 0 || f == NULL || 2579 f->f_count != unp->unp_msgcount) 2580 continue; 2581 unref[total++] = f; 2582 fhold(f); 2583 KASSERT(total <= unp_unreachable, 2584 ("unp_gc: incorrect unreachable count.")); 2585 } 2586 UNP_LINK_RUNLOCK(); 2587 2588 /* 2589 * Now flush all sockets, free'ing rights. This will free the 2590 * struct files associated with these sockets but leave each socket 2591 * with one remaining ref. 2592 */ 2593 for (i = 0; i < total; i++) { 2594 struct socket *so; 2595 2596 so = unref[i]->f_data; 2597 CURVNET_SET(so->so_vnet); 2598 sorflush(so); 2599 CURVNET_RESTORE(); 2600 } 2601 2602 /* 2603 * And finally release the sockets so they can be reclaimed. 2604 */ 2605 for (i = 0; i < total; i++) 2606 fdrop(unref[i], NULL); 2607 unp_recycled += total; 2608 free(unref, M_TEMP); 2609 } 2610 2611 static void 2612 unp_dispose_mbuf(struct mbuf *m) 2613 { 2614 2615 if (m) 2616 unp_scan(m, unp_freerights); 2617 } 2618 2619 /* 2620 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2621 */ 2622 static void 2623 unp_dispose(struct socket *so) 2624 { 2625 struct unpcb *unp; 2626 2627 unp = sotounpcb(so); 2628 UNP_LINK_WLOCK(); 2629 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2630 UNP_LINK_WUNLOCK(); 2631 if (!SOLISTENING(so)) 2632 unp_dispose_mbuf(so->so_rcv.sb_mb); 2633 } 2634 2635 static void 2636 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2637 { 2638 struct mbuf *m; 2639 struct cmsghdr *cm; 2640 void *data; 2641 socklen_t clen, datalen; 2642 2643 while (m0 != NULL) { 2644 for (m = m0; m; m = m->m_next) { 2645 if (m->m_type != MT_CONTROL) 2646 continue; 2647 2648 cm = mtod(m, struct cmsghdr *); 2649 clen = m->m_len; 2650 2651 while (cm != NULL) { 2652 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2653 break; 2654 2655 data = CMSG_DATA(cm); 2656 datalen = (caddr_t)cm + cm->cmsg_len 2657 - (caddr_t)data; 2658 2659 if (cm->cmsg_level == SOL_SOCKET && 2660 cm->cmsg_type == SCM_RIGHTS) { 2661 (*op)(data, datalen / 2662 sizeof(struct filedescent *)); 2663 } 2664 2665 if (CMSG_SPACE(datalen) < clen) { 2666 clen -= CMSG_SPACE(datalen); 2667 cm = (struct cmsghdr *) 2668 ((caddr_t)cm + CMSG_SPACE(datalen)); 2669 } else { 2670 clen = 0; 2671 cm = NULL; 2672 } 2673 } 2674 } 2675 m0 = m0->m_nextpkt; 2676 } 2677 } 2678 2679 /* 2680 * A helper function called by VFS before socket-type vnode reclamation. 2681 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2682 * use count. 2683 */ 2684 void 2685 vfs_unp_reclaim(struct vnode *vp) 2686 { 2687 struct unpcb *unp; 2688 int active; 2689 struct mtx *vplock; 2690 2691 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2692 KASSERT(vp->v_type == VSOCK, 2693 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2694 2695 active = 0; 2696 vplock = mtx_pool_find(mtxpool_sleep, vp); 2697 mtx_lock(vplock); 2698 VOP_UNP_CONNECT(vp, &unp); 2699 if (unp == NULL) 2700 goto done; 2701 UNP_PCB_LOCK(unp); 2702 if (unp->unp_vnode == vp) { 2703 VOP_UNP_DETACH(vp); 2704 unp->unp_vnode = NULL; 2705 active = 1; 2706 } 2707 UNP_PCB_UNLOCK(unp); 2708 done: 2709 mtx_unlock(vplock); 2710 if (active) 2711 vunref(vp); 2712 } 2713 2714 #ifdef DDB 2715 static void 2716 db_print_indent(int indent) 2717 { 2718 int i; 2719 2720 for (i = 0; i < indent; i++) 2721 db_printf(" "); 2722 } 2723 2724 static void 2725 db_print_unpflags(int unp_flags) 2726 { 2727 int comma; 2728 2729 comma = 0; 2730 if (unp_flags & UNP_HAVEPC) { 2731 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2732 comma = 1; 2733 } 2734 if (unp_flags & UNP_WANTCRED) { 2735 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2736 comma = 1; 2737 } 2738 if (unp_flags & UNP_CONNWAIT) { 2739 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2740 comma = 1; 2741 } 2742 if (unp_flags & UNP_CONNECTING) { 2743 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2744 comma = 1; 2745 } 2746 if (unp_flags & UNP_BINDING) { 2747 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2748 comma = 1; 2749 } 2750 } 2751 2752 static void 2753 db_print_xucred(int indent, struct xucred *xu) 2754 { 2755 int comma, i; 2756 2757 db_print_indent(indent); 2758 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2759 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2760 db_print_indent(indent); 2761 db_printf("cr_groups: "); 2762 comma = 0; 2763 for (i = 0; i < xu->cr_ngroups; i++) { 2764 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2765 comma = 1; 2766 } 2767 db_printf("\n"); 2768 } 2769 2770 static void 2771 db_print_unprefs(int indent, struct unp_head *uh) 2772 { 2773 struct unpcb *unp; 2774 int counter; 2775 2776 counter = 0; 2777 LIST_FOREACH(unp, uh, unp_reflink) { 2778 if (counter % 4 == 0) 2779 db_print_indent(indent); 2780 db_printf("%p ", unp); 2781 if (counter % 4 == 3) 2782 db_printf("\n"); 2783 counter++; 2784 } 2785 if (counter != 0 && counter % 4 != 0) 2786 db_printf("\n"); 2787 } 2788 2789 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2790 { 2791 struct unpcb *unp; 2792 2793 if (!have_addr) { 2794 db_printf("usage: show unpcb <addr>\n"); 2795 return; 2796 } 2797 unp = (struct unpcb *)addr; 2798 2799 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2800 unp->unp_vnode); 2801 2802 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2803 unp->unp_conn); 2804 2805 db_printf("unp_refs:\n"); 2806 db_print_unprefs(2, &unp->unp_refs); 2807 2808 /* XXXRW: Would be nice to print the full address, if any. */ 2809 db_printf("unp_addr: %p\n", unp->unp_addr); 2810 2811 db_printf("unp_gencnt: %llu\n", 2812 (unsigned long long)unp->unp_gencnt); 2813 2814 db_printf("unp_flags: %x (", unp->unp_flags); 2815 db_print_unpflags(unp->unp_flags); 2816 db_printf(")\n"); 2817 2818 db_printf("unp_peercred:\n"); 2819 db_print_xucred(2, &unp->unp_peercred); 2820 2821 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2822 } 2823 #endif 2824