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_count++; 534 switch (so->so_type) { 535 case SOCK_STREAM: 536 LIST_INSERT_HEAD(&unp_shead, unp, unp_link); 537 break; 538 539 case SOCK_DGRAM: 540 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link); 541 break; 542 543 case SOCK_SEQPACKET: 544 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link); 545 break; 546 547 default: 548 panic("uipc_attach"); 549 } 550 551 if (locked == false) 552 UNP_LINK_WUNLOCK(); 553 554 return (0); 555 } 556 557 static int 558 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td) 559 { 560 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 561 struct vattr vattr; 562 int error, namelen; 563 struct nameidata nd; 564 struct unpcb *unp; 565 struct vnode *vp; 566 struct mount *mp; 567 cap_rights_t rights; 568 char *buf; 569 570 if (nam->sa_family != AF_UNIX) 571 return (EAFNOSUPPORT); 572 573 unp = sotounpcb(so); 574 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 575 576 if (soun->sun_len > sizeof(struct sockaddr_un)) 577 return (EINVAL); 578 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 579 if (namelen <= 0) 580 return (EINVAL); 581 582 /* 583 * We don't allow simultaneous bind() calls on a single UNIX domain 584 * socket, so flag in-progress operations, and return an error if an 585 * operation is already in progress. 586 * 587 * Historically, we have not allowed a socket to be rebound, so this 588 * also returns an error. Not allowing re-binding simplifies the 589 * implementation and avoids a great many possible failure modes. 590 */ 591 UNP_PCB_LOCK(unp); 592 if (unp->unp_vnode != NULL) { 593 UNP_PCB_UNLOCK(unp); 594 return (EINVAL); 595 } 596 if (unp->unp_flags & UNP_BINDING) { 597 UNP_PCB_UNLOCK(unp); 598 return (EALREADY); 599 } 600 unp->unp_flags |= UNP_BINDING; 601 UNP_PCB_UNLOCK(unp); 602 603 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 604 bcopy(soun->sun_path, buf, namelen); 605 buf[namelen] = 0; 606 607 restart: 608 NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE, 609 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td); 610 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 611 error = namei(&nd); 612 if (error) 613 goto error; 614 vp = nd.ni_vp; 615 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 616 NDFREE(&nd, NDF_ONLY_PNBUF); 617 if (nd.ni_dvp == vp) 618 vrele(nd.ni_dvp); 619 else 620 vput(nd.ni_dvp); 621 if (vp != NULL) { 622 vrele(vp); 623 error = EADDRINUSE; 624 goto error; 625 } 626 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 627 if (error) 628 goto error; 629 goto restart; 630 } 631 VATTR_NULL(&vattr); 632 vattr.va_type = VSOCK; 633 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 634 #ifdef MAC 635 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 636 &vattr); 637 #endif 638 if (error == 0) 639 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 640 NDFREE(&nd, NDF_ONLY_PNBUF); 641 vput(nd.ni_dvp); 642 if (error) { 643 vn_finished_write(mp); 644 goto error; 645 } 646 vp = nd.ni_vp; 647 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 648 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 649 650 UNP_PCB_LOCK(unp); 651 VOP_UNP_BIND(vp, unp); 652 unp->unp_vnode = vp; 653 unp->unp_addr = soun; 654 unp->unp_flags &= ~UNP_BINDING; 655 UNP_PCB_UNLOCK(unp); 656 VOP_UNLOCK(vp, 0); 657 vn_finished_write(mp); 658 free(buf, M_TEMP); 659 return (0); 660 661 error: 662 UNP_PCB_LOCK(unp); 663 unp->unp_flags &= ~UNP_BINDING; 664 UNP_PCB_UNLOCK(unp); 665 free(buf, M_TEMP); 666 return (error); 667 } 668 669 static int 670 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 671 { 672 673 return (uipc_bindat(AT_FDCWD, so, nam, td)); 674 } 675 676 static int 677 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 678 { 679 int error; 680 681 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 682 error = unp_connect(so, nam, td); 683 return (error); 684 } 685 686 static int 687 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 688 struct thread *td) 689 { 690 int error; 691 692 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 693 error = unp_connectat(fd, so, nam, td); 694 return (error); 695 } 696 697 static void 698 uipc_close(struct socket *so) 699 { 700 struct unpcb *unp, *unp2; 701 struct vnode *vp = NULL; 702 struct mtx *vplock; 703 int freed; 704 unp = sotounpcb(so); 705 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 706 707 708 vplock = NULL; 709 if ((vp = unp->unp_vnode) != NULL) { 710 vplock = mtx_pool_find(mtxpool_sleep, vp); 711 mtx_lock(vplock); 712 } 713 UNP_PCB_LOCK(unp); 714 if (vp && unp->unp_vnode == NULL) { 715 mtx_unlock(vplock); 716 vp = NULL; 717 } 718 if (vp != NULL) { 719 VOP_UNP_DETACH(vp); 720 unp->unp_vnode = NULL; 721 } 722 unp2 = unp->unp_conn; 723 unp_pcb_hold(unp); 724 if (__predict_false(unp == unp2)) { 725 unp_disconnect(unp, unp2); 726 } else if (unp2 != NULL) { 727 unp_pcb_hold(unp2); 728 unp_pcb_owned_lock2(unp, unp2, freed); 729 unp_disconnect(unp, unp2); 730 if (unp_pcb_rele(unp2) == 0) 731 UNP_PCB_UNLOCK(unp2); 732 } 733 if (unp_pcb_rele(unp) == 0) 734 UNP_PCB_UNLOCK(unp); 735 if (vp) { 736 mtx_unlock(vplock); 737 vrele(vp); 738 } 739 } 740 741 static int 742 uipc_connect2(struct socket *so1, struct socket *so2) 743 { 744 struct unpcb *unp, *unp2; 745 int error; 746 747 unp = so1->so_pcb; 748 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 749 unp2 = so2->so_pcb; 750 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 751 if (unp != unp2) 752 unp_pcb_lock2(unp, unp2); 753 else 754 UNP_PCB_LOCK(unp); 755 error = unp_connect2(so1, so2, PRU_CONNECT2); 756 if (unp != unp2) 757 UNP_PCB_UNLOCK(unp2); 758 UNP_PCB_UNLOCK(unp); 759 return (error); 760 } 761 762 static void 763 uipc_detach(struct socket *so) 764 { 765 struct unpcb *unp, *unp2; 766 struct mtx *vplock; 767 struct sockaddr_un *saved_unp_addr; 768 struct vnode *vp; 769 int freeunp, local_unp_rights; 770 771 unp = sotounpcb(so); 772 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 773 774 vp = NULL; 775 vplock = NULL; 776 local_unp_rights = 0; 777 778 UNP_LINK_WLOCK(); 779 LIST_REMOVE(unp, unp_link); 780 unp->unp_gencnt = ++unp_gencnt; 781 --unp_count; 782 UNP_LINK_WUNLOCK(); 783 784 UNP_PCB_UNLOCK_ASSERT(unp); 785 restart: 786 if ((vp = unp->unp_vnode) != NULL) { 787 vplock = mtx_pool_find(mtxpool_sleep, vp); 788 mtx_lock(vplock); 789 } 790 UNP_PCB_LOCK(unp); 791 if (unp->unp_vnode != vp && 792 unp->unp_vnode != NULL) { 793 if (vplock) 794 mtx_unlock(vplock); 795 UNP_PCB_UNLOCK(unp); 796 goto restart; 797 } 798 if ((unp->unp_flags & UNP_NASCENT) != 0) { 799 goto teardown; 800 } 801 if ((vp = unp->unp_vnode) != NULL) { 802 VOP_UNP_DETACH(vp); 803 unp->unp_vnode = NULL; 804 } 805 if (__predict_false(unp == unp->unp_conn)) { 806 unp_disconnect(unp, unp); 807 unp2 = NULL; 808 goto connect_self; 809 } 810 if ((unp2 = unp->unp_conn) != NULL) { 811 unp_pcb_owned_lock2(unp, unp2, freeunp); 812 if (freeunp) 813 unp2 = NULL; 814 } 815 unp_pcb_hold(unp); 816 if (unp2 != NULL) { 817 unp_pcb_hold(unp2); 818 unp_disconnect(unp, unp2); 819 if (unp_pcb_rele(unp2) == 0) 820 UNP_PCB_UNLOCK(unp2); 821 } 822 connect_self: 823 UNP_PCB_UNLOCK(unp); 824 UNP_REF_LIST_LOCK(); 825 while (!LIST_EMPTY(&unp->unp_refs)) { 826 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 827 828 unp_pcb_hold(ref); 829 UNP_REF_LIST_UNLOCK(); 830 831 MPASS(ref != unp); 832 UNP_PCB_UNLOCK_ASSERT(ref); 833 unp_drop(ref); 834 UNP_REF_LIST_LOCK(); 835 } 836 837 UNP_REF_LIST_UNLOCK(); 838 UNP_PCB_LOCK(unp); 839 freeunp = unp_pcb_rele(unp); 840 MPASS(freeunp == 0); 841 local_unp_rights = unp_rights; 842 teardown: 843 unp->unp_socket->so_pcb = NULL; 844 saved_unp_addr = unp->unp_addr; 845 unp->unp_addr = NULL; 846 unp->unp_socket = NULL; 847 freeunp = unp_pcb_rele(unp); 848 if (saved_unp_addr != NULL) 849 free(saved_unp_addr, M_SONAME); 850 if (!freeunp) 851 UNP_PCB_UNLOCK(unp); 852 if (vp) { 853 mtx_unlock(vplock); 854 vrele(vp); 855 } 856 if (local_unp_rights) 857 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 858 } 859 860 static int 861 uipc_disconnect(struct socket *so) 862 { 863 struct unpcb *unp, *unp2; 864 int freed; 865 866 unp = sotounpcb(so); 867 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 868 869 UNP_PCB_LOCK(unp); 870 if ((unp2 = unp->unp_conn) == NULL) { 871 UNP_PCB_UNLOCK(unp); 872 return (0); 873 } 874 if (__predict_true(unp != unp2)) { 875 unp_pcb_owned_lock2(unp, unp2, freed); 876 if (__predict_false(freed)) { 877 UNP_PCB_UNLOCK(unp); 878 return (0); 879 } 880 unp_pcb_hold(unp2); 881 } 882 unp_pcb_hold(unp); 883 unp_disconnect(unp, unp2); 884 if (unp_pcb_rele(unp) == 0) 885 UNP_PCB_UNLOCK(unp); 886 if ((unp != unp2) && unp_pcb_rele(unp2) == 0) 887 UNP_PCB_UNLOCK(unp2); 888 return (0); 889 } 890 891 static int 892 uipc_listen(struct socket *so, int backlog, struct thread *td) 893 { 894 struct unpcb *unp; 895 int error; 896 897 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 898 return (EOPNOTSUPP); 899 900 unp = sotounpcb(so); 901 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 902 903 UNP_PCB_LOCK(unp); 904 if (unp->unp_vnode == NULL) { 905 /* Already connected or not bound to an address. */ 906 error = unp->unp_conn != NULL ? EINVAL : EDESTADDRREQ; 907 UNP_PCB_UNLOCK(unp); 908 return (error); 909 } 910 911 SOCK_LOCK(so); 912 error = solisten_proto_check(so); 913 if (error == 0) { 914 cru2x(td->td_ucred, &unp->unp_peercred); 915 solisten_proto(so, backlog); 916 } 917 SOCK_UNLOCK(so); 918 UNP_PCB_UNLOCK(unp); 919 return (error); 920 } 921 922 static int 923 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 924 { 925 struct unpcb *unp, *unp2; 926 const struct sockaddr *sa; 927 928 unp = sotounpcb(so); 929 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 930 931 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 932 UNP_LINK_RLOCK(); 933 /* 934 * XXX: It seems that this test always fails even when connection is 935 * established. So, this else clause is added as workaround to 936 * return PF_LOCAL sockaddr. 937 */ 938 unp2 = unp->unp_conn; 939 if (unp2 != NULL) { 940 UNP_PCB_LOCK(unp2); 941 if (unp2->unp_addr != NULL) 942 sa = (struct sockaddr *) unp2->unp_addr; 943 else 944 sa = &sun_noname; 945 bcopy(sa, *nam, sa->sa_len); 946 UNP_PCB_UNLOCK(unp2); 947 } else { 948 sa = &sun_noname; 949 bcopy(sa, *nam, sa->sa_len); 950 } 951 UNP_LINK_RUNLOCK(); 952 return (0); 953 } 954 955 static int 956 uipc_rcvd(struct socket *so, int flags) 957 { 958 struct unpcb *unp, *unp2; 959 struct socket *so2; 960 u_int mbcnt, sbcc; 961 962 unp = sotounpcb(so); 963 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 964 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 965 ("%s: socktype %d", __func__, so->so_type)); 966 967 /* 968 * Adjust backpressure on sender and wakeup any waiting to write. 969 * 970 * The unp lock is acquired to maintain the validity of the unp_conn 971 * pointer; no lock on unp2 is required as unp2->unp_socket will be 972 * static as long as we don't permit unp2 to disconnect from unp, 973 * which is prevented by the lock on unp. We cache values from 974 * so_rcv to avoid holding the so_rcv lock over the entire 975 * transaction on the remote so_snd. 976 */ 977 SOCKBUF_LOCK(&so->so_rcv); 978 mbcnt = so->so_rcv.sb_mbcnt; 979 sbcc = sbavail(&so->so_rcv); 980 SOCKBUF_UNLOCK(&so->so_rcv); 981 /* 982 * There is a benign race condition at this point. If we're planning to 983 * clear SB_STOP, but uipc_send is called on the connected socket at 984 * this instant, it might add data to the sockbuf and set SB_STOP. Then 985 * we would erroneously clear SB_STOP below, even though the sockbuf is 986 * full. The race is benign because the only ill effect is to allow the 987 * sockbuf to exceed its size limit, and the size limits are not 988 * strictly guaranteed anyway. 989 */ 990 UNP_PCB_LOCK(unp); 991 unp2 = unp->unp_conn; 992 if (unp2 == NULL) { 993 UNP_PCB_UNLOCK(unp); 994 return (0); 995 } 996 so2 = unp2->unp_socket; 997 SOCKBUF_LOCK(&so2->so_snd); 998 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 999 so2->so_snd.sb_flags &= ~SB_STOP; 1000 sowwakeup_locked(so2); 1001 UNP_PCB_UNLOCK(unp); 1002 return (0); 1003 } 1004 1005 static int 1006 connect_internal(struct socket *so, struct sockaddr *nam, struct thread *td) 1007 { 1008 int error; 1009 struct unpcb *unp; 1010 1011 unp = so->so_pcb; 1012 if (unp->unp_conn != NULL) 1013 return (EISCONN); 1014 error = unp_connect(so, nam, td); 1015 if (error) 1016 return (error); 1017 UNP_PCB_LOCK(unp); 1018 if (unp->unp_conn == NULL) { 1019 UNP_PCB_UNLOCK(unp); 1020 if (error == 0) 1021 error = ENOTCONN; 1022 } 1023 return (error); 1024 } 1025 1026 1027 static int 1028 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 1029 struct mbuf *control, struct thread *td) 1030 { 1031 struct unpcb *unp, *unp2; 1032 struct socket *so2; 1033 u_int mbcnt, sbcc; 1034 int freed, error; 1035 1036 unp = sotounpcb(so); 1037 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 1038 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 1039 so->so_type == SOCK_SEQPACKET, 1040 ("%s: socktype %d", __func__, so->so_type)); 1041 1042 freed = error = 0; 1043 if (flags & PRUS_OOB) { 1044 error = EOPNOTSUPP; 1045 goto release; 1046 } 1047 if (control != NULL && (error = unp_internalize(&control, td))) 1048 goto release; 1049 1050 unp2 = NULL; 1051 switch (so->so_type) { 1052 case SOCK_DGRAM: 1053 { 1054 const struct sockaddr *from; 1055 1056 if (nam != NULL) { 1057 /* 1058 * We return with UNP_PCB_LOCK_HELD so we know that 1059 * the reference is live if the pointer is valid. 1060 */ 1061 if ((error = connect_internal(so, nam, td))) 1062 break; 1063 MPASS(unp->unp_conn != NULL); 1064 unp2 = unp->unp_conn; 1065 } else { 1066 UNP_PCB_LOCK(unp); 1067 1068 /* 1069 * Because connect() and send() are non-atomic in a sendto() 1070 * with a target address, it's possible that the socket will 1071 * have disconnected before the send() can run. In that case 1072 * return the slightly counter-intuitive but otherwise 1073 * correct error that the socket is not connected. 1074 */ 1075 if ((unp2 = unp->unp_conn) == NULL) { 1076 UNP_PCB_UNLOCK(unp); 1077 error = ENOTCONN; 1078 break; 1079 } 1080 } 1081 if (__predict_false(unp == unp2)) { 1082 if (unp->unp_socket == NULL) { 1083 error = ENOTCONN; 1084 break; 1085 } 1086 goto connect_self; 1087 } 1088 unp_pcb_owned_lock2(unp, unp2, freed); 1089 if (__predict_false(freed)) { 1090 UNP_PCB_UNLOCK(unp); 1091 error = ENOTCONN; 1092 break; 1093 } 1094 /* 1095 * The socket referencing unp2 may have been closed 1096 * or unp may have been disconnected if the unp lock 1097 * was dropped to acquire unp2. 1098 */ 1099 if (__predict_false(unp->unp_conn == NULL) || 1100 unp2->unp_socket == NULL) { 1101 UNP_PCB_UNLOCK(unp); 1102 if (unp_pcb_rele(unp2) == 0) 1103 UNP_PCB_UNLOCK(unp2); 1104 error = ENOTCONN; 1105 break; 1106 } 1107 connect_self: 1108 if (unp2->unp_flags & UNP_WANTCRED) 1109 control = unp_addsockcred(td, control); 1110 if (unp->unp_addr != NULL) 1111 from = (struct sockaddr *)unp->unp_addr; 1112 else 1113 from = &sun_noname; 1114 so2 = unp2->unp_socket; 1115 SOCKBUF_LOCK(&so2->so_rcv); 1116 if (sbappendaddr_locked(&so2->so_rcv, from, m, 1117 control)) { 1118 sorwakeup_locked(so2); 1119 m = NULL; 1120 control = NULL; 1121 } else { 1122 SOCKBUF_UNLOCK(&so2->so_rcv); 1123 error = ENOBUFS; 1124 } 1125 if (nam != NULL) 1126 unp_disconnect(unp, unp2); 1127 if (__predict_true(unp != unp2)) 1128 UNP_PCB_UNLOCK(unp2); 1129 UNP_PCB_UNLOCK(unp); 1130 break; 1131 } 1132 1133 case SOCK_SEQPACKET: 1134 case SOCK_STREAM: 1135 if ((so->so_state & SS_ISCONNECTED) == 0) { 1136 if (nam != NULL) { 1137 if ((error = connect_internal(so, nam, td))) 1138 break; 1139 } else { 1140 error = ENOTCONN; 1141 break; 1142 } 1143 } else if ((unp2 = unp->unp_conn) == NULL) { 1144 error = ENOTCONN; 1145 break; 1146 } else if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 1147 error = EPIPE; 1148 break; 1149 } else { 1150 UNP_PCB_LOCK(unp); 1151 if ((unp2 = unp->unp_conn) == NULL) { 1152 UNP_PCB_UNLOCK(unp); 1153 error = ENOTCONN; 1154 break; 1155 } 1156 } 1157 unp_pcb_owned_lock2(unp, unp2, freed); 1158 UNP_PCB_UNLOCK(unp); 1159 if (__predict_false(freed)) { 1160 error = ENOTCONN; 1161 break; 1162 } 1163 if ((so2 = unp2->unp_socket) == NULL) { 1164 UNP_PCB_UNLOCK(unp2); 1165 error = ENOTCONN; 1166 break; 1167 } 1168 SOCKBUF_LOCK(&so2->so_rcv); 1169 if (unp2->unp_flags & UNP_WANTCRED) { 1170 /* 1171 * Credentials are passed only once on SOCK_STREAM 1172 * and SOCK_SEQPACKET. 1173 */ 1174 unp2->unp_flags &= ~UNP_WANTCRED; 1175 control = unp_addsockcred(td, control); 1176 } 1177 1178 /* 1179 * Send to paired receive port and wake up readers. Don't 1180 * check for space available in the receive buffer if we're 1181 * attaching ancillary data; Unix domain sockets only check 1182 * for space in the sending sockbuf, and that check is 1183 * performed one level up the stack. At that level we cannot 1184 * precisely account for the amount of buffer space used 1185 * (e.g., because control messages are not yet internalized). 1186 */ 1187 switch (so->so_type) { 1188 case SOCK_STREAM: 1189 if (control != NULL) { 1190 sbappendcontrol_locked(&so2->so_rcv, m, 1191 control); 1192 control = NULL; 1193 } else 1194 sbappend_locked(&so2->so_rcv, m, flags); 1195 break; 1196 1197 case SOCK_SEQPACKET: { 1198 const struct sockaddr *from; 1199 1200 from = &sun_noname; 1201 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 1202 from, m, control)) 1203 control = NULL; 1204 break; 1205 } 1206 } 1207 1208 mbcnt = so2->so_rcv.sb_mbcnt; 1209 sbcc = sbavail(&so2->so_rcv); 1210 if (sbcc) 1211 sorwakeup_locked(so2); 1212 else 1213 SOCKBUF_UNLOCK(&so2->so_rcv); 1214 1215 /* 1216 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1217 * it would be possible for uipc_rcvd to be called at this 1218 * point, drain the receiving sockbuf, clear SB_STOP, and then 1219 * we would set SB_STOP below. That could lead to an empty 1220 * sockbuf having SB_STOP set 1221 */ 1222 SOCKBUF_LOCK(&so->so_snd); 1223 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1224 so->so_snd.sb_flags |= SB_STOP; 1225 SOCKBUF_UNLOCK(&so->so_snd); 1226 UNP_PCB_UNLOCK(unp2); 1227 m = NULL; 1228 break; 1229 } 1230 1231 /* 1232 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1233 */ 1234 if (flags & PRUS_EOF) { 1235 UNP_PCB_LOCK(unp); 1236 socantsendmore(so); 1237 unp_shutdown(unp); 1238 UNP_PCB_UNLOCK(unp); 1239 } 1240 if (control != NULL && error != 0) 1241 unp_dispose_mbuf(control); 1242 1243 release: 1244 if (control != NULL) 1245 m_freem(control); 1246 /* 1247 * In case of PRUS_NOTREADY, uipc_ready() is responsible 1248 * for freeing memory. 1249 */ 1250 if (m != NULL && (flags & PRUS_NOTREADY) == 0) 1251 m_freem(m); 1252 return (error); 1253 } 1254 1255 static int 1256 uipc_ready(struct socket *so, struct mbuf *m, int count) 1257 { 1258 struct unpcb *unp, *unp2; 1259 struct socket *so2; 1260 int error; 1261 1262 unp = sotounpcb(so); 1263 1264 UNP_PCB_LOCK(unp); 1265 if ((unp2 = unp->unp_conn) == NULL) { 1266 UNP_PCB_UNLOCK(unp); 1267 goto error; 1268 } 1269 if (unp != unp2) { 1270 if (UNP_PCB_TRYLOCK(unp2) == 0) { 1271 unp_pcb_hold(unp2); 1272 UNP_PCB_UNLOCK(unp); 1273 UNP_PCB_LOCK(unp2); 1274 if (unp_pcb_rele(unp2)) 1275 goto error; 1276 } else 1277 UNP_PCB_UNLOCK(unp); 1278 } 1279 so2 = unp2->unp_socket; 1280 1281 SOCKBUF_LOCK(&so2->so_rcv); 1282 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1283 sorwakeup_locked(so2); 1284 else 1285 SOCKBUF_UNLOCK(&so2->so_rcv); 1286 1287 UNP_PCB_UNLOCK(unp2); 1288 1289 return (error); 1290 error: 1291 for (int i = 0; i < count; i++) 1292 m = m_free(m); 1293 return (ECONNRESET); 1294 } 1295 1296 static int 1297 uipc_sense(struct socket *so, struct stat *sb) 1298 { 1299 struct unpcb *unp; 1300 1301 unp = sotounpcb(so); 1302 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1303 1304 sb->st_blksize = so->so_snd.sb_hiwat; 1305 UNP_PCB_LOCK(unp); 1306 sb->st_dev = NODEV; 1307 if (unp->unp_ino == 0) 1308 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 1309 sb->st_ino = unp->unp_ino; 1310 UNP_PCB_UNLOCK(unp); 1311 return (0); 1312 } 1313 1314 static int 1315 uipc_shutdown(struct socket *so) 1316 { 1317 struct unpcb *unp; 1318 1319 unp = sotounpcb(so); 1320 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1321 1322 UNP_PCB_LOCK(unp); 1323 socantsendmore(so); 1324 unp_shutdown(unp); 1325 UNP_PCB_UNLOCK(unp); 1326 return (0); 1327 } 1328 1329 static int 1330 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1331 { 1332 struct unpcb *unp; 1333 const struct sockaddr *sa; 1334 1335 unp = sotounpcb(so); 1336 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1337 1338 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1339 UNP_PCB_LOCK(unp); 1340 if (unp->unp_addr != NULL) 1341 sa = (struct sockaddr *) unp->unp_addr; 1342 else 1343 sa = &sun_noname; 1344 bcopy(sa, *nam, sa->sa_len); 1345 UNP_PCB_UNLOCK(unp); 1346 return (0); 1347 } 1348 1349 static struct pr_usrreqs uipc_usrreqs_dgram = { 1350 .pru_abort = uipc_abort, 1351 .pru_accept = uipc_accept, 1352 .pru_attach = uipc_attach, 1353 .pru_bind = uipc_bind, 1354 .pru_bindat = uipc_bindat, 1355 .pru_connect = uipc_connect, 1356 .pru_connectat = uipc_connectat, 1357 .pru_connect2 = uipc_connect2, 1358 .pru_detach = uipc_detach, 1359 .pru_disconnect = uipc_disconnect, 1360 .pru_listen = uipc_listen, 1361 .pru_peeraddr = uipc_peeraddr, 1362 .pru_rcvd = uipc_rcvd, 1363 .pru_send = uipc_send, 1364 .pru_sense = uipc_sense, 1365 .pru_shutdown = uipc_shutdown, 1366 .pru_sockaddr = uipc_sockaddr, 1367 .pru_soreceive = soreceive_dgram, 1368 .pru_close = uipc_close, 1369 }; 1370 1371 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1372 .pru_abort = uipc_abort, 1373 .pru_accept = uipc_accept, 1374 .pru_attach = uipc_attach, 1375 .pru_bind = uipc_bind, 1376 .pru_bindat = uipc_bindat, 1377 .pru_connect = uipc_connect, 1378 .pru_connectat = uipc_connectat, 1379 .pru_connect2 = uipc_connect2, 1380 .pru_detach = uipc_detach, 1381 .pru_disconnect = uipc_disconnect, 1382 .pru_listen = uipc_listen, 1383 .pru_peeraddr = uipc_peeraddr, 1384 .pru_rcvd = uipc_rcvd, 1385 .pru_send = uipc_send, 1386 .pru_sense = uipc_sense, 1387 .pru_shutdown = uipc_shutdown, 1388 .pru_sockaddr = uipc_sockaddr, 1389 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1390 .pru_close = uipc_close, 1391 }; 1392 1393 static struct pr_usrreqs uipc_usrreqs_stream = { 1394 .pru_abort = uipc_abort, 1395 .pru_accept = uipc_accept, 1396 .pru_attach = uipc_attach, 1397 .pru_bind = uipc_bind, 1398 .pru_bindat = uipc_bindat, 1399 .pru_connect = uipc_connect, 1400 .pru_connectat = uipc_connectat, 1401 .pru_connect2 = uipc_connect2, 1402 .pru_detach = uipc_detach, 1403 .pru_disconnect = uipc_disconnect, 1404 .pru_listen = uipc_listen, 1405 .pru_peeraddr = uipc_peeraddr, 1406 .pru_rcvd = uipc_rcvd, 1407 .pru_send = uipc_send, 1408 .pru_ready = uipc_ready, 1409 .pru_sense = uipc_sense, 1410 .pru_shutdown = uipc_shutdown, 1411 .pru_sockaddr = uipc_sockaddr, 1412 .pru_soreceive = soreceive_generic, 1413 .pru_close = uipc_close, 1414 }; 1415 1416 static int 1417 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1418 { 1419 struct unpcb *unp; 1420 struct xucred xu; 1421 int error, optval; 1422 1423 if (sopt->sopt_level != 0) 1424 return (EINVAL); 1425 1426 unp = sotounpcb(so); 1427 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1428 error = 0; 1429 switch (sopt->sopt_dir) { 1430 case SOPT_GET: 1431 switch (sopt->sopt_name) { 1432 case LOCAL_PEERCRED: 1433 UNP_PCB_LOCK(unp); 1434 if (unp->unp_flags & UNP_HAVEPC) 1435 xu = unp->unp_peercred; 1436 else { 1437 if (so->so_type == SOCK_STREAM) 1438 error = ENOTCONN; 1439 else 1440 error = EINVAL; 1441 } 1442 UNP_PCB_UNLOCK(unp); 1443 if (error == 0) 1444 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1445 break; 1446 1447 case LOCAL_CREDS: 1448 /* Unlocked read. */ 1449 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1450 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1451 break; 1452 1453 case LOCAL_CONNWAIT: 1454 /* Unlocked read. */ 1455 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1456 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1457 break; 1458 1459 default: 1460 error = EOPNOTSUPP; 1461 break; 1462 } 1463 break; 1464 1465 case SOPT_SET: 1466 switch (sopt->sopt_name) { 1467 case LOCAL_CREDS: 1468 case LOCAL_CONNWAIT: 1469 error = sooptcopyin(sopt, &optval, sizeof(optval), 1470 sizeof(optval)); 1471 if (error) 1472 break; 1473 1474 #define OPTSET(bit) do { \ 1475 UNP_PCB_LOCK(unp); \ 1476 if (optval) \ 1477 unp->unp_flags |= bit; \ 1478 else \ 1479 unp->unp_flags &= ~bit; \ 1480 UNP_PCB_UNLOCK(unp); \ 1481 } while (0) 1482 1483 switch (sopt->sopt_name) { 1484 case LOCAL_CREDS: 1485 OPTSET(UNP_WANTCRED); 1486 break; 1487 1488 case LOCAL_CONNWAIT: 1489 OPTSET(UNP_CONNWAIT); 1490 break; 1491 1492 default: 1493 break; 1494 } 1495 break; 1496 #undef OPTSET 1497 default: 1498 error = ENOPROTOOPT; 1499 break; 1500 } 1501 break; 1502 1503 default: 1504 error = EOPNOTSUPP; 1505 break; 1506 } 1507 return (error); 1508 } 1509 1510 static int 1511 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1512 { 1513 1514 return (unp_connectat(AT_FDCWD, so, nam, td)); 1515 } 1516 1517 static int 1518 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1519 struct thread *td) 1520 { 1521 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1522 struct vnode *vp; 1523 struct socket *so2; 1524 struct unpcb *unp, *unp2, *unp3; 1525 struct nameidata nd; 1526 char buf[SOCK_MAXADDRLEN]; 1527 struct sockaddr *sa; 1528 cap_rights_t rights; 1529 int error, len, freed; 1530 struct mtx *vplock; 1531 1532 if (nam->sa_family != AF_UNIX) 1533 return (EAFNOSUPPORT); 1534 if (nam->sa_len > sizeof(struct sockaddr_un)) 1535 return (EINVAL); 1536 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1537 if (len <= 0) 1538 return (EINVAL); 1539 bcopy(soun->sun_path, buf, len); 1540 buf[len] = 0; 1541 1542 unp = sotounpcb(so); 1543 UNP_PCB_LOCK(unp); 1544 if (unp->unp_flags & UNP_CONNECTING) { 1545 UNP_PCB_UNLOCK(unp); 1546 return (EALREADY); 1547 } 1548 unp->unp_flags |= UNP_CONNECTING; 1549 UNP_PCB_UNLOCK(unp); 1550 1551 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1552 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1553 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td); 1554 error = namei(&nd); 1555 if (error) 1556 vp = NULL; 1557 else 1558 vp = nd.ni_vp; 1559 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1560 NDFREE(&nd, NDF_ONLY_PNBUF); 1561 if (error) 1562 goto bad; 1563 1564 if (vp->v_type != VSOCK) { 1565 error = ENOTSOCK; 1566 goto bad; 1567 } 1568 #ifdef MAC 1569 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1570 if (error) 1571 goto bad; 1572 #endif 1573 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1574 if (error) 1575 goto bad; 1576 1577 unp = sotounpcb(so); 1578 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1579 1580 vplock = mtx_pool_find(mtxpool_sleep, vp); 1581 mtx_lock(vplock); 1582 VOP_UNP_CONNECT(vp, &unp2); 1583 if (unp2 == NULL) { 1584 error = ECONNREFUSED; 1585 goto bad2; 1586 } 1587 so2 = unp2->unp_socket; 1588 if (so->so_type != so2->so_type) { 1589 error = EPROTOTYPE; 1590 goto bad2; 1591 } 1592 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1593 if (so2->so_options & SO_ACCEPTCONN) { 1594 CURVNET_SET(so2->so_vnet); 1595 so2 = sonewconn(so2, 0); 1596 CURVNET_RESTORE(); 1597 } else 1598 so2 = NULL; 1599 if (so2 == NULL) { 1600 error = ECONNREFUSED; 1601 goto bad2; 1602 } 1603 unp3 = sotounpcb(so2); 1604 unp_pcb_lock2(unp2, unp3); 1605 if (unp2->unp_addr != NULL) { 1606 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1607 unp3->unp_addr = (struct sockaddr_un *) sa; 1608 sa = NULL; 1609 } 1610 1611 unp_copy_peercred(td, unp3, unp, unp2); 1612 1613 UNP_PCB_UNLOCK(unp2); 1614 unp2 = unp3; 1615 unp_pcb_owned_lock2(unp2, unp, freed); 1616 if (__predict_false(freed)) { 1617 UNP_PCB_UNLOCK(unp2); 1618 error = ECONNREFUSED; 1619 goto bad2; 1620 } 1621 #ifdef MAC 1622 mac_socketpeer_set_from_socket(so, so2); 1623 mac_socketpeer_set_from_socket(so2, so); 1624 #endif 1625 } else { 1626 if (unp == unp2) 1627 UNP_PCB_LOCK(unp); 1628 else 1629 unp_pcb_lock2(unp, unp2); 1630 } 1631 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1632 sotounpcb(so2) == unp2, 1633 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1634 error = unp_connect2(so, so2, PRU_CONNECT); 1635 if (unp != unp2) 1636 UNP_PCB_UNLOCK(unp2); 1637 UNP_PCB_UNLOCK(unp); 1638 bad2: 1639 mtx_unlock(vplock); 1640 bad: 1641 if (vp != NULL) { 1642 vput(vp); 1643 } 1644 free(sa, M_SONAME); 1645 UNP_PCB_LOCK(unp); 1646 unp->unp_flags &= ~UNP_CONNECTING; 1647 UNP_PCB_UNLOCK(unp); 1648 return (error); 1649 } 1650 1651 /* 1652 * Set socket peer credentials at connection time. 1653 * 1654 * The client's PCB credentials are copied from its process structure. The 1655 * server's PCB credentials are copied from the socket on which it called 1656 * listen(2). uipc_listen cached that process's credentials at the time. 1657 */ 1658 void 1659 unp_copy_peercred(struct thread *td, struct unpcb *client_unp, 1660 struct unpcb *server_unp, struct unpcb *listen_unp) 1661 { 1662 cru2x(td->td_ucred, &client_unp->unp_peercred); 1663 client_unp->unp_flags |= UNP_HAVEPC; 1664 1665 memcpy(&server_unp->unp_peercred, &listen_unp->unp_peercred, 1666 sizeof(server_unp->unp_peercred)); 1667 server_unp->unp_flags |= UNP_HAVEPC; 1668 if (listen_unp->unp_flags & UNP_WANTCRED) 1669 client_unp->unp_flags |= UNP_WANTCRED; 1670 } 1671 1672 static int 1673 unp_connect2(struct socket *so, struct socket *so2, int req) 1674 { 1675 struct unpcb *unp; 1676 struct unpcb *unp2; 1677 1678 unp = sotounpcb(so); 1679 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1680 unp2 = sotounpcb(so2); 1681 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1682 1683 UNP_PCB_LOCK_ASSERT(unp); 1684 UNP_PCB_LOCK_ASSERT(unp2); 1685 1686 if (so2->so_type != so->so_type) 1687 return (EPROTOTYPE); 1688 unp2->unp_flags &= ~UNP_NASCENT; 1689 unp->unp_conn = unp2; 1690 unp_pcb_hold(unp2); 1691 unp_pcb_hold(unp); 1692 switch (so->so_type) { 1693 case SOCK_DGRAM: 1694 UNP_REF_LIST_LOCK(); 1695 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1696 UNP_REF_LIST_UNLOCK(); 1697 soisconnected(so); 1698 break; 1699 1700 case SOCK_STREAM: 1701 case SOCK_SEQPACKET: 1702 unp2->unp_conn = unp; 1703 if (req == PRU_CONNECT && 1704 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1705 soisconnecting(so); 1706 else 1707 soisconnected(so); 1708 soisconnected(so2); 1709 break; 1710 1711 default: 1712 panic("unp_connect2"); 1713 } 1714 return (0); 1715 } 1716 1717 static void 1718 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1719 { 1720 struct socket *so, *so2; 1721 int freed __unused; 1722 1723 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1724 1725 UNP_PCB_LOCK_ASSERT(unp); 1726 UNP_PCB_LOCK_ASSERT(unp2); 1727 1728 if (unp->unp_conn == NULL && unp2->unp_conn == NULL) 1729 return; 1730 1731 MPASS(unp->unp_conn == unp2); 1732 unp->unp_conn = NULL; 1733 so = unp->unp_socket; 1734 so2 = unp2->unp_socket; 1735 switch (unp->unp_socket->so_type) { 1736 case SOCK_DGRAM: 1737 UNP_REF_LIST_LOCK(); 1738 LIST_REMOVE(unp, unp_reflink); 1739 UNP_REF_LIST_UNLOCK(); 1740 if (so) { 1741 SOCK_LOCK(so); 1742 so->so_state &= ~SS_ISCONNECTED; 1743 SOCK_UNLOCK(so); 1744 } 1745 break; 1746 1747 case SOCK_STREAM: 1748 case SOCK_SEQPACKET: 1749 if (so) 1750 soisdisconnected(so); 1751 MPASS(unp2->unp_conn == unp); 1752 unp2->unp_conn = NULL; 1753 if (so2) 1754 soisdisconnected(so2); 1755 break; 1756 } 1757 freed = unp_pcb_rele(unp); 1758 MPASS(freed == 0); 1759 freed = unp_pcb_rele(unp2); 1760 MPASS(freed == 0); 1761 } 1762 1763 /* 1764 * unp_pcblist() walks the global list of struct unpcb's to generate a 1765 * pointer list, bumping the refcount on each unpcb. It then copies them out 1766 * sequentially, validating the generation number on each to see if it has 1767 * been detached. All of this is necessary because copyout() may sleep on 1768 * disk I/O. 1769 */ 1770 static int 1771 unp_pcblist(SYSCTL_HANDLER_ARGS) 1772 { 1773 struct unpcb *unp, **unp_list; 1774 unp_gen_t gencnt; 1775 struct xunpgen *xug; 1776 struct unp_head *head; 1777 struct xunpcb *xu; 1778 u_int i; 1779 int error, freeunp, n; 1780 1781 switch ((intptr_t)arg1) { 1782 case SOCK_STREAM: 1783 head = &unp_shead; 1784 break; 1785 1786 case SOCK_DGRAM: 1787 head = &unp_dhead; 1788 break; 1789 1790 case SOCK_SEQPACKET: 1791 head = &unp_sphead; 1792 break; 1793 1794 default: 1795 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1796 } 1797 1798 /* 1799 * The process of preparing the PCB list is too time-consuming and 1800 * resource-intensive to repeat twice on every request. 1801 */ 1802 if (req->oldptr == NULL) { 1803 n = unp_count; 1804 req->oldidx = 2 * (sizeof *xug) 1805 + (n + n/8) * sizeof(struct xunpcb); 1806 return (0); 1807 } 1808 1809 if (req->newptr != NULL) 1810 return (EPERM); 1811 1812 /* 1813 * OK, now we're committed to doing something. 1814 */ 1815 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1816 UNP_LINK_RLOCK(); 1817 gencnt = unp_gencnt; 1818 n = unp_count; 1819 UNP_LINK_RUNLOCK(); 1820 1821 xug->xug_len = sizeof *xug; 1822 xug->xug_count = n; 1823 xug->xug_gen = gencnt; 1824 xug->xug_sogen = so_gencnt; 1825 error = SYSCTL_OUT(req, xug, sizeof *xug); 1826 if (error) { 1827 free(xug, M_TEMP); 1828 return (error); 1829 } 1830 1831 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1832 1833 UNP_LINK_RLOCK(); 1834 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1835 unp = LIST_NEXT(unp, unp_link)) { 1836 UNP_PCB_LOCK(unp); 1837 if (unp->unp_gencnt <= gencnt) { 1838 if (cr_cansee(req->td->td_ucred, 1839 unp->unp_socket->so_cred)) { 1840 UNP_PCB_UNLOCK(unp); 1841 continue; 1842 } 1843 unp_list[i++] = unp; 1844 unp_pcb_hold(unp); 1845 } 1846 UNP_PCB_UNLOCK(unp); 1847 } 1848 UNP_LINK_RUNLOCK(); 1849 n = i; /* In case we lost some during malloc. */ 1850 1851 error = 0; 1852 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1853 for (i = 0; i < n; i++) { 1854 unp = unp_list[i]; 1855 UNP_PCB_LOCK(unp); 1856 freeunp = unp_pcb_rele(unp); 1857 1858 if (freeunp == 0 && unp->unp_gencnt <= gencnt) { 1859 xu->xu_len = sizeof *xu; 1860 xu->xu_unpp = (uintptr_t)unp; 1861 /* 1862 * XXX - need more locking here to protect against 1863 * connect/disconnect races for SMP. 1864 */ 1865 if (unp->unp_addr != NULL) 1866 bcopy(unp->unp_addr, &xu->xu_addr, 1867 unp->unp_addr->sun_len); 1868 else 1869 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1870 if (unp->unp_conn != NULL && 1871 unp->unp_conn->unp_addr != NULL) 1872 bcopy(unp->unp_conn->unp_addr, 1873 &xu->xu_caddr, 1874 unp->unp_conn->unp_addr->sun_len); 1875 else 1876 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1877 xu->unp_vnode = (uintptr_t)unp->unp_vnode; 1878 xu->unp_conn = (uintptr_t)unp->unp_conn; 1879 xu->xu_firstref = (uintptr_t)LIST_FIRST(&unp->unp_refs); 1880 xu->xu_nextref = (uintptr_t)LIST_NEXT(unp, unp_reflink); 1881 xu->unp_gencnt = unp->unp_gencnt; 1882 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1883 UNP_PCB_UNLOCK(unp); 1884 error = SYSCTL_OUT(req, xu, sizeof *xu); 1885 } else if (freeunp == 0) 1886 UNP_PCB_UNLOCK(unp); 1887 } 1888 free(xu, M_TEMP); 1889 if (!error) { 1890 /* 1891 * Give the user an updated idea of our state. If the 1892 * generation differs from what we told her before, she knows 1893 * that something happened while we were processing this 1894 * request, and it might be necessary to retry. 1895 */ 1896 xug->xug_gen = unp_gencnt; 1897 xug->xug_sogen = so_gencnt; 1898 xug->xug_count = unp_count; 1899 error = SYSCTL_OUT(req, xug, sizeof *xug); 1900 } 1901 free(unp_list, M_TEMP); 1902 free(xug, M_TEMP); 1903 return (error); 1904 } 1905 1906 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1907 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1908 "List of active local datagram sockets"); 1909 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1910 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1911 "List of active local stream sockets"); 1912 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1913 CTLTYPE_OPAQUE | CTLFLAG_RD, 1914 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1915 "List of active local seqpacket sockets"); 1916 1917 static void 1918 unp_shutdown(struct unpcb *unp) 1919 { 1920 struct unpcb *unp2; 1921 struct socket *so; 1922 1923 UNP_PCB_LOCK_ASSERT(unp); 1924 1925 unp2 = unp->unp_conn; 1926 if ((unp->unp_socket->so_type == SOCK_STREAM || 1927 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1928 so = unp2->unp_socket; 1929 if (so != NULL) 1930 socantrcvmore(so); 1931 } 1932 } 1933 1934 static void 1935 unp_drop(struct unpcb *unp) 1936 { 1937 struct socket *so = unp->unp_socket; 1938 struct unpcb *unp2; 1939 int freed; 1940 1941 /* 1942 * Regardless of whether the socket's peer dropped the connection 1943 * with this socket by aborting or disconnecting, POSIX requires 1944 * that ECONNRESET is returned. 1945 */ 1946 /* acquire a reference so that unp isn't freed from underneath us */ 1947 1948 UNP_PCB_LOCK(unp); 1949 if (so) 1950 so->so_error = ECONNRESET; 1951 unp2 = unp->unp_conn; 1952 if (unp2 == unp) { 1953 unp_disconnect(unp, unp2); 1954 } else if (unp2 != NULL) { 1955 unp_pcb_hold(unp2); 1956 unp_pcb_owned_lock2(unp, unp2, freed); 1957 unp_disconnect(unp, unp2); 1958 if (unp_pcb_rele(unp2) == 0) 1959 UNP_PCB_UNLOCK(unp2); 1960 } 1961 if (unp_pcb_rele(unp) == 0) 1962 UNP_PCB_UNLOCK(unp); 1963 } 1964 1965 static void 1966 unp_freerights(struct filedescent **fdep, int fdcount) 1967 { 1968 struct file *fp; 1969 int i; 1970 1971 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1972 1973 for (i = 0; i < fdcount; i++) { 1974 fp = fdep[i]->fde_file; 1975 filecaps_free(&fdep[i]->fde_caps); 1976 unp_discard(fp); 1977 } 1978 free(fdep[0], M_FILECAPS); 1979 } 1980 1981 static int 1982 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 1983 { 1984 struct thread *td = curthread; /* XXX */ 1985 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1986 int i; 1987 int *fdp; 1988 struct filedesc *fdesc = td->td_proc->p_fd; 1989 struct filedescent **fdep; 1990 void *data; 1991 socklen_t clen = control->m_len, datalen; 1992 int error, newfds; 1993 u_int newlen; 1994 1995 UNP_LINK_UNLOCK_ASSERT(); 1996 1997 error = 0; 1998 if (controlp != NULL) /* controlp == NULL => free control messages */ 1999 *controlp = NULL; 2000 while (cm != NULL) { 2001 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 2002 error = EINVAL; 2003 break; 2004 } 2005 data = CMSG_DATA(cm); 2006 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2007 if (cm->cmsg_level == SOL_SOCKET 2008 && cm->cmsg_type == SCM_RIGHTS) { 2009 newfds = datalen / sizeof(*fdep); 2010 if (newfds == 0) 2011 goto next; 2012 fdep = data; 2013 2014 /* If we're not outputting the descriptors free them. */ 2015 if (error || controlp == NULL) { 2016 unp_freerights(fdep, newfds); 2017 goto next; 2018 } 2019 FILEDESC_XLOCK(fdesc); 2020 2021 /* 2022 * Now change each pointer to an fd in the global 2023 * table to an integer that is the index to the local 2024 * fd table entry that we set up to point to the 2025 * global one we are transferring. 2026 */ 2027 newlen = newfds * sizeof(int); 2028 *controlp = sbcreatecontrol(NULL, newlen, 2029 SCM_RIGHTS, SOL_SOCKET); 2030 if (*controlp == NULL) { 2031 FILEDESC_XUNLOCK(fdesc); 2032 error = E2BIG; 2033 unp_freerights(fdep, newfds); 2034 goto next; 2035 } 2036 2037 fdp = (int *) 2038 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2039 if (fdallocn(td, 0, fdp, newfds) != 0) { 2040 FILEDESC_XUNLOCK(fdesc); 2041 error = EMSGSIZE; 2042 unp_freerights(fdep, newfds); 2043 m_freem(*controlp); 2044 *controlp = NULL; 2045 goto next; 2046 } 2047 for (i = 0; i < newfds; i++, fdp++) { 2048 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2049 (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0, 2050 &fdep[i]->fde_caps); 2051 unp_externalize_fp(fdep[i]->fde_file); 2052 } 2053 2054 /* 2055 * The new type indicates that the mbuf data refers to 2056 * kernel resources that may need to be released before 2057 * the mbuf is freed. 2058 */ 2059 m_chtype(*controlp, MT_EXTCONTROL); 2060 FILEDESC_XUNLOCK(fdesc); 2061 free(fdep[0], M_FILECAPS); 2062 } else { 2063 /* We can just copy anything else across. */ 2064 if (error || controlp == NULL) 2065 goto next; 2066 *controlp = sbcreatecontrol(NULL, datalen, 2067 cm->cmsg_type, cm->cmsg_level); 2068 if (*controlp == NULL) { 2069 error = ENOBUFS; 2070 goto next; 2071 } 2072 bcopy(data, 2073 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2074 datalen); 2075 } 2076 controlp = &(*controlp)->m_next; 2077 2078 next: 2079 if (CMSG_SPACE(datalen) < clen) { 2080 clen -= CMSG_SPACE(datalen); 2081 cm = (struct cmsghdr *) 2082 ((caddr_t)cm + CMSG_SPACE(datalen)); 2083 } else { 2084 clen = 0; 2085 cm = NULL; 2086 } 2087 } 2088 2089 m_freem(control); 2090 return (error); 2091 } 2092 2093 static void 2094 unp_zone_change(void *tag) 2095 { 2096 2097 uma_zone_set_max(unp_zone, maxsockets); 2098 } 2099 2100 static void 2101 unp_init(void) 2102 { 2103 2104 #ifdef VIMAGE 2105 if (!IS_DEFAULT_VNET(curvnet)) 2106 return; 2107 #endif 2108 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 2109 NULL, NULL, UMA_ALIGN_CACHE, 0); 2110 if (unp_zone == NULL) 2111 panic("unp_init"); 2112 uma_zone_set_max(unp_zone, maxsockets); 2113 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2114 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2115 NULL, EVENTHANDLER_PRI_ANY); 2116 LIST_INIT(&unp_dhead); 2117 LIST_INIT(&unp_shead); 2118 LIST_INIT(&unp_sphead); 2119 SLIST_INIT(&unp_defers); 2120 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2121 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2122 UNP_LINK_LOCK_INIT(); 2123 UNP_DEFERRED_LOCK_INIT(); 2124 } 2125 2126 static int 2127 unp_internalize(struct mbuf **controlp, struct thread *td) 2128 { 2129 struct mbuf *control = *controlp; 2130 struct proc *p = td->td_proc; 2131 struct filedesc *fdesc = p->p_fd; 2132 struct bintime *bt; 2133 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2134 struct cmsgcred *cmcred; 2135 struct filedescent *fde, **fdep, *fdev; 2136 struct file *fp; 2137 struct timeval *tv; 2138 struct timespec *ts; 2139 int i, *fdp; 2140 void *data; 2141 socklen_t clen = control->m_len, datalen; 2142 int error, oldfds; 2143 u_int newlen; 2144 2145 UNP_LINK_UNLOCK_ASSERT(); 2146 2147 error = 0; 2148 *controlp = NULL; 2149 while (cm != NULL) { 2150 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2151 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2152 error = EINVAL; 2153 goto out; 2154 } 2155 data = CMSG_DATA(cm); 2156 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2157 2158 switch (cm->cmsg_type) { 2159 /* 2160 * Fill in credential information. 2161 */ 2162 case SCM_CREDS: 2163 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2164 SCM_CREDS, SOL_SOCKET); 2165 if (*controlp == NULL) { 2166 error = ENOBUFS; 2167 goto out; 2168 } 2169 cmcred = (struct cmsgcred *) 2170 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2171 cmcred->cmcred_pid = p->p_pid; 2172 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2173 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2174 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2175 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2176 CMGROUP_MAX); 2177 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2178 cmcred->cmcred_groups[i] = 2179 td->td_ucred->cr_groups[i]; 2180 break; 2181 2182 case SCM_RIGHTS: 2183 oldfds = datalen / sizeof (int); 2184 if (oldfds == 0) 2185 break; 2186 /* 2187 * Check that all the FDs passed in refer to legal 2188 * files. If not, reject the entire operation. 2189 */ 2190 fdp = data; 2191 FILEDESC_SLOCK(fdesc); 2192 for (i = 0; i < oldfds; i++, fdp++) { 2193 fp = fget_locked(fdesc, *fdp); 2194 if (fp == NULL) { 2195 FILEDESC_SUNLOCK(fdesc); 2196 error = EBADF; 2197 goto out; 2198 } 2199 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2200 FILEDESC_SUNLOCK(fdesc); 2201 error = EOPNOTSUPP; 2202 goto out; 2203 } 2204 2205 } 2206 2207 /* 2208 * Now replace the integer FDs with pointers to the 2209 * file structure and capability rights. 2210 */ 2211 newlen = oldfds * sizeof(fdep[0]); 2212 *controlp = sbcreatecontrol(NULL, newlen, 2213 SCM_RIGHTS, SOL_SOCKET); 2214 if (*controlp == NULL) { 2215 FILEDESC_SUNLOCK(fdesc); 2216 error = E2BIG; 2217 goto out; 2218 } 2219 fdp = data; 2220 fdep = (struct filedescent **) 2221 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2222 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2223 M_WAITOK); 2224 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2225 fde = &fdesc->fd_ofiles[*fdp]; 2226 fdep[i] = fdev; 2227 fdep[i]->fde_file = fde->fde_file; 2228 filecaps_copy(&fde->fde_caps, 2229 &fdep[i]->fde_caps, true); 2230 unp_internalize_fp(fdep[i]->fde_file); 2231 } 2232 FILEDESC_SUNLOCK(fdesc); 2233 break; 2234 2235 case SCM_TIMESTAMP: 2236 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2237 SCM_TIMESTAMP, SOL_SOCKET); 2238 if (*controlp == NULL) { 2239 error = ENOBUFS; 2240 goto out; 2241 } 2242 tv = (struct timeval *) 2243 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2244 microtime(tv); 2245 break; 2246 2247 case SCM_BINTIME: 2248 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2249 SCM_BINTIME, SOL_SOCKET); 2250 if (*controlp == NULL) { 2251 error = ENOBUFS; 2252 goto out; 2253 } 2254 bt = (struct bintime *) 2255 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2256 bintime(bt); 2257 break; 2258 2259 case SCM_REALTIME: 2260 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2261 SCM_REALTIME, SOL_SOCKET); 2262 if (*controlp == NULL) { 2263 error = ENOBUFS; 2264 goto out; 2265 } 2266 ts = (struct timespec *) 2267 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2268 nanotime(ts); 2269 break; 2270 2271 case SCM_MONOTONIC: 2272 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2273 SCM_MONOTONIC, SOL_SOCKET); 2274 if (*controlp == NULL) { 2275 error = ENOBUFS; 2276 goto out; 2277 } 2278 ts = (struct timespec *) 2279 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2280 nanouptime(ts); 2281 break; 2282 2283 default: 2284 error = EINVAL; 2285 goto out; 2286 } 2287 2288 controlp = &(*controlp)->m_next; 2289 if (CMSG_SPACE(datalen) < clen) { 2290 clen -= CMSG_SPACE(datalen); 2291 cm = (struct cmsghdr *) 2292 ((caddr_t)cm + CMSG_SPACE(datalen)); 2293 } else { 2294 clen = 0; 2295 cm = NULL; 2296 } 2297 } 2298 2299 out: 2300 m_freem(control); 2301 return (error); 2302 } 2303 2304 static struct mbuf * 2305 unp_addsockcred(struct thread *td, struct mbuf *control) 2306 { 2307 struct mbuf *m, *n, *n_prev; 2308 struct sockcred *sc; 2309 const struct cmsghdr *cm; 2310 int ngroups; 2311 int i; 2312 2313 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2314 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 2315 if (m == NULL) 2316 return (control); 2317 2318 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 2319 sc->sc_uid = td->td_ucred->cr_ruid; 2320 sc->sc_euid = td->td_ucred->cr_uid; 2321 sc->sc_gid = td->td_ucred->cr_rgid; 2322 sc->sc_egid = td->td_ucred->cr_gid; 2323 sc->sc_ngroups = ngroups; 2324 for (i = 0; i < sc->sc_ngroups; i++) 2325 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2326 2327 /* 2328 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2329 * created SCM_CREDS control message (struct sockcred) has another 2330 * format. 2331 */ 2332 if (control != NULL) 2333 for (n = control, n_prev = NULL; n != NULL;) { 2334 cm = mtod(n, struct cmsghdr *); 2335 if (cm->cmsg_level == SOL_SOCKET && 2336 cm->cmsg_type == SCM_CREDS) { 2337 if (n_prev == NULL) 2338 control = n->m_next; 2339 else 2340 n_prev->m_next = n->m_next; 2341 n = m_free(n); 2342 } else { 2343 n_prev = n; 2344 n = n->m_next; 2345 } 2346 } 2347 2348 /* Prepend it to the head. */ 2349 m->m_next = control; 2350 return (m); 2351 } 2352 2353 static struct unpcb * 2354 fptounp(struct file *fp) 2355 { 2356 struct socket *so; 2357 2358 if (fp->f_type != DTYPE_SOCKET) 2359 return (NULL); 2360 if ((so = fp->f_data) == NULL) 2361 return (NULL); 2362 if (so->so_proto->pr_domain != &localdomain) 2363 return (NULL); 2364 return sotounpcb(so); 2365 } 2366 2367 static void 2368 unp_discard(struct file *fp) 2369 { 2370 struct unp_defer *dr; 2371 2372 if (unp_externalize_fp(fp)) { 2373 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2374 dr->ud_fp = fp; 2375 UNP_DEFERRED_LOCK(); 2376 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2377 UNP_DEFERRED_UNLOCK(); 2378 atomic_add_int(&unp_defers_count, 1); 2379 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2380 } else 2381 (void) closef(fp, (struct thread *)NULL); 2382 } 2383 2384 static void 2385 unp_process_defers(void *arg __unused, int pending) 2386 { 2387 struct unp_defer *dr; 2388 SLIST_HEAD(, unp_defer) drl; 2389 int count; 2390 2391 SLIST_INIT(&drl); 2392 for (;;) { 2393 UNP_DEFERRED_LOCK(); 2394 if (SLIST_FIRST(&unp_defers) == NULL) { 2395 UNP_DEFERRED_UNLOCK(); 2396 break; 2397 } 2398 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2399 UNP_DEFERRED_UNLOCK(); 2400 count = 0; 2401 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2402 SLIST_REMOVE_HEAD(&drl, ud_link); 2403 closef(dr->ud_fp, NULL); 2404 free(dr, M_TEMP); 2405 count++; 2406 } 2407 atomic_add_int(&unp_defers_count, -count); 2408 } 2409 } 2410 2411 static void 2412 unp_internalize_fp(struct file *fp) 2413 { 2414 struct unpcb *unp; 2415 2416 UNP_LINK_WLOCK(); 2417 if ((unp = fptounp(fp)) != NULL) { 2418 unp->unp_file = fp; 2419 unp->unp_msgcount++; 2420 } 2421 fhold(fp); 2422 unp_rights++; 2423 UNP_LINK_WUNLOCK(); 2424 } 2425 2426 static int 2427 unp_externalize_fp(struct file *fp) 2428 { 2429 struct unpcb *unp; 2430 int ret; 2431 2432 UNP_LINK_WLOCK(); 2433 if ((unp = fptounp(fp)) != NULL) { 2434 unp->unp_msgcount--; 2435 ret = 1; 2436 } else 2437 ret = 0; 2438 unp_rights--; 2439 UNP_LINK_WUNLOCK(); 2440 return (ret); 2441 } 2442 2443 /* 2444 * unp_defer indicates whether additional work has been defered for a future 2445 * pass through unp_gc(). It is thread local and does not require explicit 2446 * synchronization. 2447 */ 2448 static int unp_marked; 2449 static int unp_unreachable; 2450 2451 static void 2452 unp_accessable(struct filedescent **fdep, int fdcount) 2453 { 2454 struct unpcb *unp; 2455 struct file *fp; 2456 int i; 2457 2458 for (i = 0; i < fdcount; i++) { 2459 fp = fdep[i]->fde_file; 2460 if ((unp = fptounp(fp)) == NULL) 2461 continue; 2462 if (unp->unp_gcflag & UNPGC_REF) 2463 continue; 2464 unp->unp_gcflag &= ~UNPGC_DEAD; 2465 unp->unp_gcflag |= UNPGC_REF; 2466 unp_marked++; 2467 } 2468 } 2469 2470 static void 2471 unp_gc_process(struct unpcb *unp) 2472 { 2473 struct socket *so, *soa; 2474 struct file *fp; 2475 2476 /* Already processed. */ 2477 if (unp->unp_gcflag & UNPGC_SCANNED) 2478 return; 2479 fp = unp->unp_file; 2480 2481 /* 2482 * Check for a socket potentially in a cycle. It must be in a 2483 * queue as indicated by msgcount, and this must equal the file 2484 * reference count. Note that when msgcount is 0 the file is NULL. 2485 */ 2486 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2487 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2488 unp->unp_gcflag |= UNPGC_DEAD; 2489 unp_unreachable++; 2490 return; 2491 } 2492 2493 so = unp->unp_socket; 2494 SOCK_LOCK(so); 2495 if (SOLISTENING(so)) { 2496 /* 2497 * Mark all sockets in our accept queue. 2498 */ 2499 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2500 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2501 continue; 2502 SOCKBUF_LOCK(&soa->so_rcv); 2503 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2504 SOCKBUF_UNLOCK(&soa->so_rcv); 2505 } 2506 } else { 2507 /* 2508 * Mark all sockets we reference with RIGHTS. 2509 */ 2510 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2511 SOCKBUF_LOCK(&so->so_rcv); 2512 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2513 SOCKBUF_UNLOCK(&so->so_rcv); 2514 } 2515 } 2516 SOCK_UNLOCK(so); 2517 unp->unp_gcflag |= UNPGC_SCANNED; 2518 } 2519 2520 static int unp_recycled; 2521 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2522 "Number of unreachable sockets claimed by the garbage collector."); 2523 2524 static int unp_taskcount; 2525 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2526 "Number of times the garbage collector has run."); 2527 2528 static void 2529 unp_gc(__unused void *arg, int pending) 2530 { 2531 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2532 NULL }; 2533 struct unp_head **head; 2534 struct file *f, **unref; 2535 struct unpcb *unp; 2536 int i, total; 2537 2538 unp_taskcount++; 2539 UNP_LINK_RLOCK(); 2540 /* 2541 * First clear all gc flags from previous runs, apart from 2542 * UNPGC_IGNORE_RIGHTS. 2543 */ 2544 for (head = heads; *head != NULL; head++) 2545 LIST_FOREACH(unp, *head, unp_link) 2546 unp->unp_gcflag = 2547 (unp->unp_gcflag & UNPGC_IGNORE_RIGHTS); 2548 2549 /* 2550 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2551 * is reachable all of the sockets it references are reachable. 2552 * Stop the scan once we do a complete loop without discovering 2553 * a new reachable socket. 2554 */ 2555 do { 2556 unp_unreachable = 0; 2557 unp_marked = 0; 2558 for (head = heads; *head != NULL; head++) 2559 LIST_FOREACH(unp, *head, unp_link) 2560 unp_gc_process(unp); 2561 } while (unp_marked); 2562 UNP_LINK_RUNLOCK(); 2563 if (unp_unreachable == 0) 2564 return; 2565 2566 /* 2567 * Allocate space for a local list of dead unpcbs. 2568 */ 2569 unref = malloc(unp_unreachable * sizeof(struct file *), 2570 M_TEMP, M_WAITOK); 2571 2572 /* 2573 * Iterate looking for sockets which have been specifically marked 2574 * as as unreachable and store them locally. 2575 */ 2576 UNP_LINK_RLOCK(); 2577 for (total = 0, head = heads; *head != NULL; head++) 2578 LIST_FOREACH(unp, *head, unp_link) 2579 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2580 f = unp->unp_file; 2581 if (unp->unp_msgcount == 0 || f == NULL || 2582 f->f_count != unp->unp_msgcount) 2583 continue; 2584 unref[total++] = f; 2585 fhold(f); 2586 KASSERT(total <= unp_unreachable, 2587 ("unp_gc: incorrect unreachable count.")); 2588 } 2589 UNP_LINK_RUNLOCK(); 2590 2591 /* 2592 * Now flush all sockets, free'ing rights. This will free the 2593 * struct files associated with these sockets but leave each socket 2594 * with one remaining ref. 2595 */ 2596 for (i = 0; i < total; i++) { 2597 struct socket *so; 2598 2599 so = unref[i]->f_data; 2600 CURVNET_SET(so->so_vnet); 2601 sorflush(so); 2602 CURVNET_RESTORE(); 2603 } 2604 2605 /* 2606 * And finally release the sockets so they can be reclaimed. 2607 */ 2608 for (i = 0; i < total; i++) 2609 fdrop(unref[i], NULL); 2610 unp_recycled += total; 2611 free(unref, M_TEMP); 2612 } 2613 2614 static void 2615 unp_dispose_mbuf(struct mbuf *m) 2616 { 2617 2618 if (m) 2619 unp_scan(m, unp_freerights); 2620 } 2621 2622 /* 2623 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2624 */ 2625 static void 2626 unp_dispose(struct socket *so) 2627 { 2628 struct unpcb *unp; 2629 2630 unp = sotounpcb(so); 2631 UNP_LINK_WLOCK(); 2632 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2633 UNP_LINK_WUNLOCK(); 2634 if (!SOLISTENING(so)) 2635 unp_dispose_mbuf(so->so_rcv.sb_mb); 2636 } 2637 2638 static void 2639 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2640 { 2641 struct mbuf *m; 2642 struct cmsghdr *cm; 2643 void *data; 2644 socklen_t clen, datalen; 2645 2646 while (m0 != NULL) { 2647 for (m = m0; m; m = m->m_next) { 2648 if (m->m_type != MT_CONTROL) 2649 continue; 2650 2651 cm = mtod(m, struct cmsghdr *); 2652 clen = m->m_len; 2653 2654 while (cm != NULL) { 2655 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2656 break; 2657 2658 data = CMSG_DATA(cm); 2659 datalen = (caddr_t)cm + cm->cmsg_len 2660 - (caddr_t)data; 2661 2662 if (cm->cmsg_level == SOL_SOCKET && 2663 cm->cmsg_type == SCM_RIGHTS) { 2664 (*op)(data, datalen / 2665 sizeof(struct filedescent *)); 2666 } 2667 2668 if (CMSG_SPACE(datalen) < clen) { 2669 clen -= CMSG_SPACE(datalen); 2670 cm = (struct cmsghdr *) 2671 ((caddr_t)cm + CMSG_SPACE(datalen)); 2672 } else { 2673 clen = 0; 2674 cm = NULL; 2675 } 2676 } 2677 } 2678 m0 = m0->m_nextpkt; 2679 } 2680 } 2681 2682 /* 2683 * A helper function called by VFS before socket-type vnode reclamation. 2684 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2685 * use count. 2686 */ 2687 void 2688 vfs_unp_reclaim(struct vnode *vp) 2689 { 2690 struct unpcb *unp; 2691 int active; 2692 struct mtx *vplock; 2693 2694 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2695 KASSERT(vp->v_type == VSOCK, 2696 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2697 2698 active = 0; 2699 vplock = mtx_pool_find(mtxpool_sleep, vp); 2700 mtx_lock(vplock); 2701 VOP_UNP_CONNECT(vp, &unp); 2702 if (unp == NULL) 2703 goto done; 2704 UNP_PCB_LOCK(unp); 2705 if (unp->unp_vnode == vp) { 2706 VOP_UNP_DETACH(vp); 2707 unp->unp_vnode = NULL; 2708 active = 1; 2709 } 2710 UNP_PCB_UNLOCK(unp); 2711 done: 2712 mtx_unlock(vplock); 2713 if (active) 2714 vunref(vp); 2715 } 2716 2717 #ifdef DDB 2718 static void 2719 db_print_indent(int indent) 2720 { 2721 int i; 2722 2723 for (i = 0; i < indent; i++) 2724 db_printf(" "); 2725 } 2726 2727 static void 2728 db_print_unpflags(int unp_flags) 2729 { 2730 int comma; 2731 2732 comma = 0; 2733 if (unp_flags & UNP_HAVEPC) { 2734 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2735 comma = 1; 2736 } 2737 if (unp_flags & UNP_WANTCRED) { 2738 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2739 comma = 1; 2740 } 2741 if (unp_flags & UNP_CONNWAIT) { 2742 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2743 comma = 1; 2744 } 2745 if (unp_flags & UNP_CONNECTING) { 2746 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2747 comma = 1; 2748 } 2749 if (unp_flags & UNP_BINDING) { 2750 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2751 comma = 1; 2752 } 2753 } 2754 2755 static void 2756 db_print_xucred(int indent, struct xucred *xu) 2757 { 2758 int comma, i; 2759 2760 db_print_indent(indent); 2761 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2762 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2763 db_print_indent(indent); 2764 db_printf("cr_groups: "); 2765 comma = 0; 2766 for (i = 0; i < xu->cr_ngroups; i++) { 2767 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2768 comma = 1; 2769 } 2770 db_printf("\n"); 2771 } 2772 2773 static void 2774 db_print_unprefs(int indent, struct unp_head *uh) 2775 { 2776 struct unpcb *unp; 2777 int counter; 2778 2779 counter = 0; 2780 LIST_FOREACH(unp, uh, unp_reflink) { 2781 if (counter % 4 == 0) 2782 db_print_indent(indent); 2783 db_printf("%p ", unp); 2784 if (counter % 4 == 3) 2785 db_printf("\n"); 2786 counter++; 2787 } 2788 if (counter != 0 && counter % 4 != 0) 2789 db_printf("\n"); 2790 } 2791 2792 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2793 { 2794 struct unpcb *unp; 2795 2796 if (!have_addr) { 2797 db_printf("usage: show unpcb <addr>\n"); 2798 return; 2799 } 2800 unp = (struct unpcb *)addr; 2801 2802 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2803 unp->unp_vnode); 2804 2805 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2806 unp->unp_conn); 2807 2808 db_printf("unp_refs:\n"); 2809 db_print_unprefs(2, &unp->unp_refs); 2810 2811 /* XXXRW: Would be nice to print the full address, if any. */ 2812 db_printf("unp_addr: %p\n", unp->unp_addr); 2813 2814 db_printf("unp_gencnt: %llu\n", 2815 (unsigned long long)unp->unp_gencnt); 2816 2817 db_printf("unp_flags: %x (", unp->unp_flags); 2818 db_print_unpflags(unp->unp_flags); 2819 db_printf(")\n"); 2820 2821 db_printf("unp_peercred:\n"); 2822 db_print_xucred(2, &unp->unp_peercred); 2823 2824 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2825 } 2826 #endif 2827