1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1982, 1986, 1989, 1991, 1993 5 * The Regents of the University of California. All Rights Reserved. 6 * Copyright (c) 2004-2009 Robert N. M. Watson All Rights Reserved. 7 * Copyright (c) 2018 Matthew Macy 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 34 */ 35 36 /* 37 * UNIX Domain (Local) Sockets 38 * 39 * This is an implementation of UNIX (local) domain sockets. Each socket has 40 * an associated struct unpcb (UNIX protocol control block). Stream sockets 41 * may be connected to 0 or 1 other socket. Datagram sockets may be 42 * connected to 0, 1, or many other sockets. Sockets may be created and 43 * connected in pairs (socketpair(2)), or bound/connected to using the file 44 * system name space. For most purposes, only the receive socket buffer is 45 * used, as sending on one socket delivers directly to the receive socket 46 * buffer of a second socket. 47 * 48 * The implementation is substantially complicated by the fact that 49 * "ancillary data", such as file descriptors or credentials, may be passed 50 * across UNIX domain sockets. The potential for passing UNIX domain sockets 51 * over other UNIX domain sockets requires the implementation of a simple 52 * garbage collector to find and tear down cycles of disconnected sockets. 53 * 54 * TODO: 55 * RDM 56 * rethink name space problems 57 * need a proper out-of-band 58 */ 59 60 #include <sys/cdefs.h> 61 __FBSDID("$FreeBSD$"); 62 63 #include "opt_ddb.h" 64 65 #include <sys/param.h> 66 #include <sys/capsicum.h> 67 #include <sys/domain.h> 68 #include <sys/fcntl.h> 69 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 70 #include <sys/eventhandler.h> 71 #include <sys/file.h> 72 #include <sys/filedesc.h> 73 #include <sys/kernel.h> 74 #include <sys/lock.h> 75 #include <sys/mbuf.h> 76 #include <sys/mount.h> 77 #include <sys/mutex.h> 78 #include <sys/namei.h> 79 #include <sys/proc.h> 80 #include <sys/protosw.h> 81 #include <sys/queue.h> 82 #include <sys/resourcevar.h> 83 #include <sys/rwlock.h> 84 #include <sys/socket.h> 85 #include <sys/socketvar.h> 86 #include <sys/signalvar.h> 87 #include <sys/stat.h> 88 #include <sys/sx.h> 89 #include <sys/sysctl.h> 90 #include <sys/systm.h> 91 #include <sys/taskqueue.h> 92 #include <sys/un.h> 93 #include <sys/unpcb.h> 94 #include <sys/vnode.h> 95 96 #include <net/vnet.h> 97 98 #ifdef DDB 99 #include <ddb/ddb.h> 100 #endif 101 102 #include <security/mac/mac_framework.h> 103 104 #include <vm/uma.h> 105 106 MALLOC_DECLARE(M_FILECAPS); 107 108 /* 109 * Locking key: 110 * (l) Locked using list lock 111 * (g) Locked using linkage lock 112 */ 113 114 static uma_zone_t unp_zone; 115 static unp_gen_t unp_gencnt; /* (l) */ 116 static u_int unp_count; /* (l) Count of local sockets. */ 117 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 118 static int unp_rights; /* (g) File descriptors in flight. */ 119 static struct unp_head unp_shead; /* (l) List of stream sockets. */ 120 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 121 static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */ 122 123 struct unp_defer { 124 SLIST_ENTRY(unp_defer) ud_link; 125 struct file *ud_fp; 126 }; 127 static SLIST_HEAD(, unp_defer) unp_defers; 128 static int unp_defers_count; 129 130 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 131 132 /* 133 * Garbage collection of cyclic file descriptor/socket references occurs 134 * asynchronously in a taskqueue context in order to avoid recursion and 135 * reentrance in the UNIX domain socket, file descriptor, and socket layer 136 * code. See unp_gc() for a full description. 137 */ 138 static struct timeout_task unp_gc_task; 139 140 /* 141 * The close of unix domain sockets attached as SCM_RIGHTS is 142 * postponed to the taskqueue, to avoid arbitrary recursion depth. 143 * The attached sockets might have another sockets attached. 144 */ 145 static struct task unp_defer_task; 146 147 /* 148 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 149 * stream sockets, although the total for sender and receiver is actually 150 * only PIPSIZ. 151 * 152 * Datagram sockets really use the sendspace as the maximum datagram size, 153 * and don't really want to reserve the sendspace. Their recvspace should be 154 * large enough for at least one max-size datagram plus address. 155 */ 156 #ifndef PIPSIZ 157 #define PIPSIZ 8192 158 #endif 159 static u_long unpst_sendspace = PIPSIZ; 160 static u_long unpst_recvspace = PIPSIZ; 161 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 162 static u_long unpdg_recvspace = 4*1024; 163 static u_long unpsp_sendspace = PIPSIZ; /* really max datagram size */ 164 static u_long unpsp_recvspace = PIPSIZ; 165 166 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain"); 167 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, 168 "SOCK_STREAM"); 169 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM"); 170 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, CTLFLAG_RW, 0, 171 "SOCK_SEQPACKET"); 172 173 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 174 &unpst_sendspace, 0, "Default stream send space."); 175 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 176 &unpst_recvspace, 0, "Default stream receive space."); 177 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 178 &unpdg_sendspace, 0, "Default datagram send space."); 179 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 180 &unpdg_recvspace, 0, "Default datagram receive space."); 181 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW, 182 &unpsp_sendspace, 0, "Default seqpacket send space."); 183 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW, 184 &unpsp_recvspace, 0, "Default seqpacket receive space."); 185 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 186 "File descriptors in flight."); 187 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD, 188 &unp_defers_count, 0, 189 "File descriptors deferred to taskqueue for close."); 190 191 /* 192 * Locking and synchronization: 193 * 194 * Three types of locks exist in the local domain socket implementation: a 195 * a global linkage rwlock, the mtxpool lock, and per-unpcb mutexes. 196 * The linkage lock protects the socket count, global generation number, 197 * and stream/datagram global lists. 198 * 199 * The mtxpool lock protects the vnode from being modified while referenced. 200 * Lock ordering requires that it be acquired before any unpcb locks. 201 * 202 * The unpcb lock (unp_mtx) protects all fields in the unpcb. Of particular 203 * note is that this includes the unp_conn field. So long as the unpcb lock 204 * is held the reference to the unpcb pointed to by unp_conn is valid. If we 205 * require that the unpcb pointed to by unp_conn remain live in cases where 206 * we need to drop the unp_mtx as when we need to acquire the lock for a 207 * second unpcb the caller must first acquire an additional reference on the 208 * second unpcb and then revalidate any state (typically check that unp_conn 209 * is non-NULL) upon requiring the initial unpcb lock. The lock ordering 210 * between unpcbs is the conventional ascending address order. Two helper 211 * routines exist for this: 212 * 213 * - unp_pcb_lock2(unp, unp2) - which just acquires the two locks in the 214 * safe ordering. 215 * 216 * - unp_pcb_owned_lock2(unp, unp2, freed) - the lock for unp is held 217 * when called. If unp is unlocked and unp2 is subsequently freed 218 * freed will be set to 1. 219 * 220 * The helper routines for references are: 221 * 222 * - unp_pcb_hold(unp): Can be called any time we currently hold a valid 223 * reference to unp. 224 * 225 * - unp_pcb_rele(unp): The caller must hold the unp lock. If we are 226 * releasing the last reference, detach must have been called thus 227 * unp->unp_socket be NULL. 228 * 229 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 230 * allocated in pru_attach() and freed in pru_detach(). The validity of that 231 * pointer is an invariant, so no lock is required to dereference the so_pcb 232 * pointer if a valid socket reference is held by the caller. In practice, 233 * this is always true during operations performed on a socket. Each unpcb 234 * has a back-pointer to its socket, unp_socket, which will be stable under 235 * the same circumstances. 236 * 237 * This pointer may only be safely dereferenced as long as a valid reference 238 * to the unpcb is held. Typically, this reference will be from the socket, 239 * or from another unpcb when the referring unpcb's lock is held (in order 240 * that the reference not be invalidated during use). For example, to follow 241 * unp->unp_conn->unp_socket, you need to hold a lock on unp_conn to guarantee 242 * that detach is not run clearing unp_socket. 243 * 244 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 245 * protocols, bind() is a non-atomic operation, and connect() requires 246 * potential sleeping in the protocol, due to potentially waiting on local or 247 * distributed file systems. We try to separate "lookup" operations, which 248 * may sleep, and the IPC operations themselves, which typically can occur 249 * with relative atomicity as locks can be held over the entire operation. 250 * 251 * Another tricky issue is simultaneous multi-threaded or multi-process 252 * access to a single UNIX domain socket. These are handled by the flags 253 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 254 * binding, both of which involve dropping UNIX domain socket locks in order 255 * to perform namei() and other file system operations. 256 */ 257 static struct rwlock unp_link_rwlock; 258 static struct mtx unp_defers_lock; 259 260 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 261 "unp_link_rwlock") 262 263 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 264 RA_LOCKED) 265 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 266 RA_UNLOCKED) 267 268 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 269 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 270 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 271 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 272 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 273 RA_WLOCKED) 274 #define UNP_LINK_WOWNED() rw_wowned(&unp_link_rwlock) 275 276 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \ 277 "unp_defer", NULL, MTX_DEF) 278 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock) 279 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock) 280 281 #define UNP_REF_LIST_LOCK() UNP_DEFERRED_LOCK(); 282 #define UNP_REF_LIST_UNLOCK() UNP_DEFERRED_UNLOCK(); 283 284 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 285 "unp", "unp", \ 286 MTX_DUPOK|MTX_DEF) 287 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 288 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 289 #define UNP_PCB_TRYLOCK(unp) mtx_trylock(&(unp)->unp_mtx) 290 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 291 #define UNP_PCB_OWNED(unp) mtx_owned(&(unp)->unp_mtx) 292 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 293 #define UNP_PCB_UNLOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_NOTOWNED) 294 295 static int uipc_connect2(struct socket *, struct socket *); 296 static int uipc_ctloutput(struct socket *, struct sockopt *); 297 static int unp_connect(struct socket *, struct sockaddr *, 298 struct thread *); 299 static int unp_connectat(int, struct socket *, struct sockaddr *, 300 struct thread *); 301 static int unp_connect2(struct socket *so, struct socket *so2, int); 302 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 303 static void unp_dispose(struct socket *so); 304 static void unp_dispose_mbuf(struct mbuf *); 305 static void unp_shutdown(struct unpcb *); 306 static void unp_drop(struct unpcb *); 307 static void unp_gc(__unused void *, int); 308 static void unp_scan(struct mbuf *, void (*)(struct filedescent **, int)); 309 static void unp_discard(struct file *); 310 static void unp_freerights(struct filedescent **, int); 311 static void unp_init(void); 312 static int unp_internalize(struct mbuf **, struct thread *); 313 static void unp_internalize_fp(struct file *); 314 static int unp_externalize(struct mbuf *, struct mbuf **, int); 315 static int unp_externalize_fp(struct file *); 316 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 317 static void unp_process_defers(void * __unused, int); 318 319 320 static void 321 unp_pcb_hold(struct unpcb *unp) 322 { 323 MPASS(unp->unp_refcount); 324 refcount_acquire(&unp->unp_refcount); 325 } 326 327 static int 328 unp_pcb_rele(struct unpcb *unp) 329 { 330 int freed; 331 332 UNP_PCB_LOCK_ASSERT(unp); 333 MPASS(unp->unp_refcount); 334 if ((freed = refcount_release(&unp->unp_refcount))) { 335 /* we got here with having detached? */ 336 MPASS(unp->unp_socket == NULL); 337 UNP_PCB_UNLOCK(unp); 338 UNP_PCB_LOCK_DESTROY(unp); 339 uma_zfree(unp_zone, unp); 340 } 341 return (freed); 342 } 343 344 static void 345 unp_pcb_lock2(struct unpcb *unp, struct unpcb *unp2) 346 { 347 MPASS(unp != unp2); 348 UNP_PCB_UNLOCK_ASSERT(unp); 349 UNP_PCB_UNLOCK_ASSERT(unp2); 350 if ((uintptr_t)unp2 > (uintptr_t)unp) { 351 UNP_PCB_LOCK(unp); 352 UNP_PCB_LOCK(unp2); 353 } else { 354 UNP_PCB_LOCK(unp2); 355 UNP_PCB_LOCK(unp); 356 } 357 } 358 359 static __noinline void 360 unp_pcb_owned_lock2_slowpath(struct unpcb *unp, struct unpcb **unp2p, int *freed) 361 362 { 363 struct unpcb *unp2; 364 365 unp2 = *unp2p; 366 unp_pcb_hold((unp2)); 367 UNP_PCB_UNLOCK((unp)); 368 UNP_PCB_LOCK((unp2)); 369 UNP_PCB_LOCK((unp)); 370 *freed = unp_pcb_rele((unp2)); 371 if (*freed) 372 *unp2p = NULL; 373 } 374 375 #define unp_pcb_owned_lock2(unp, unp2, freed) do { \ 376 freed = 0; \ 377 UNP_PCB_LOCK_ASSERT((unp)); \ 378 UNP_PCB_UNLOCK_ASSERT((unp2)); \ 379 MPASS(unp != unp2); \ 380 if (__predict_true(UNP_PCB_TRYLOCK((unp2)))) \ 381 break; \ 382 else if ((uintptr_t)(unp2) > (uintptr_t)(unp)) \ 383 UNP_PCB_LOCK((unp2)); \ 384 else { \ 385 unp_pcb_owned_lock2_slowpath((unp), &(unp2), &freed); \ 386 } \ 387 } while (0) 388 389 390 /* 391 * Definitions of protocols supported in the LOCAL domain. 392 */ 393 static struct domain localdomain; 394 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 395 static struct pr_usrreqs uipc_usrreqs_seqpacket; 396 static struct protosw localsw[] = { 397 { 398 .pr_type = SOCK_STREAM, 399 .pr_domain = &localdomain, 400 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 401 .pr_ctloutput = &uipc_ctloutput, 402 .pr_usrreqs = &uipc_usrreqs_stream 403 }, 404 { 405 .pr_type = SOCK_DGRAM, 406 .pr_domain = &localdomain, 407 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 408 .pr_ctloutput = &uipc_ctloutput, 409 .pr_usrreqs = &uipc_usrreqs_dgram 410 }, 411 { 412 .pr_type = SOCK_SEQPACKET, 413 .pr_domain = &localdomain, 414 415 /* 416 * XXXRW: For now, PR_ADDR because soreceive will bump into them 417 * due to our use of sbappendaddr. A new sbappend variants is needed 418 * that supports both atomic record writes and control data. 419 */ 420 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD| 421 PR_RIGHTS, 422 .pr_ctloutput = &uipc_ctloutput, 423 .pr_usrreqs = &uipc_usrreqs_seqpacket, 424 }, 425 }; 426 427 static struct domain localdomain = { 428 .dom_family = AF_LOCAL, 429 .dom_name = "local", 430 .dom_init = unp_init, 431 .dom_externalize = unp_externalize, 432 .dom_dispose = unp_dispose, 433 .dom_protosw = localsw, 434 .dom_protoswNPROTOSW = &localsw[nitems(localsw)] 435 }; 436 DOMAIN_SET(local); 437 438 static void 439 uipc_abort(struct socket *so) 440 { 441 struct unpcb *unp, *unp2; 442 443 unp = sotounpcb(so); 444 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 445 UNP_PCB_UNLOCK_ASSERT(unp); 446 447 UNP_PCB_LOCK(unp); 448 unp2 = unp->unp_conn; 449 if (unp2 != NULL) { 450 unp_pcb_hold(unp2); 451 UNP_PCB_UNLOCK(unp); 452 unp_drop(unp2); 453 } else 454 UNP_PCB_UNLOCK(unp); 455 } 456 457 static int 458 uipc_accept(struct socket *so, struct sockaddr **nam) 459 { 460 struct unpcb *unp, *unp2; 461 const struct sockaddr *sa; 462 463 /* 464 * Pass back name of connected socket, if it was bound and we are 465 * still connected (our peer may have closed already!). 466 */ 467 unp = sotounpcb(so); 468 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 469 470 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 471 UNP_LINK_RLOCK(); 472 unp2 = unp->unp_conn; 473 if (unp2 != NULL && unp2->unp_addr != NULL) { 474 UNP_PCB_LOCK(unp2); 475 sa = (struct sockaddr *) unp2->unp_addr; 476 bcopy(sa, *nam, sa->sa_len); 477 UNP_PCB_UNLOCK(unp2); 478 } else { 479 sa = &sun_noname; 480 bcopy(sa, *nam, sa->sa_len); 481 } 482 UNP_LINK_RUNLOCK(); 483 return (0); 484 } 485 486 static int 487 uipc_attach(struct socket *so, int proto, struct thread *td) 488 { 489 u_long sendspace, recvspace; 490 struct unpcb *unp; 491 int error; 492 bool locked; 493 494 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 495 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 496 switch (so->so_type) { 497 case SOCK_STREAM: 498 sendspace = unpst_sendspace; 499 recvspace = unpst_recvspace; 500 break; 501 502 case SOCK_DGRAM: 503 sendspace = unpdg_sendspace; 504 recvspace = unpdg_recvspace; 505 break; 506 507 case SOCK_SEQPACKET: 508 sendspace = unpsp_sendspace; 509 recvspace = unpsp_recvspace; 510 break; 511 512 default: 513 panic("uipc_attach"); 514 } 515 error = soreserve(so, sendspace, recvspace); 516 if (error) 517 return (error); 518 } 519 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 520 if (unp == NULL) 521 return (ENOBUFS); 522 LIST_INIT(&unp->unp_refs); 523 UNP_PCB_LOCK_INIT(unp); 524 unp->unp_socket = so; 525 so->so_pcb = unp; 526 unp->unp_refcount = 1; 527 if (so->so_listen != NULL) 528 unp->unp_flags |= UNP_NASCENT; 529 530 if ((locked = UNP_LINK_WOWNED()) == false) 531 UNP_LINK_WLOCK(); 532 533 unp->unp_gencnt = ++unp_gencnt; 534 unp_count++; 535 switch (so->so_type) { 536 case SOCK_STREAM: 537 LIST_INSERT_HEAD(&unp_shead, unp, unp_link); 538 break; 539 540 case SOCK_DGRAM: 541 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link); 542 break; 543 544 case SOCK_SEQPACKET: 545 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link); 546 break; 547 548 default: 549 panic("uipc_attach"); 550 } 551 552 if (locked == false) 553 UNP_LINK_WUNLOCK(); 554 555 return (0); 556 } 557 558 static int 559 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td) 560 { 561 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 562 struct vattr vattr; 563 int error, namelen; 564 struct nameidata nd; 565 struct unpcb *unp; 566 struct vnode *vp; 567 struct mount *mp; 568 cap_rights_t rights; 569 char *buf; 570 571 if (nam->sa_family != AF_UNIX) 572 return (EAFNOSUPPORT); 573 574 unp = sotounpcb(so); 575 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 576 577 if (soun->sun_len > sizeof(struct sockaddr_un)) 578 return (EINVAL); 579 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 580 if (namelen <= 0) 581 return (EINVAL); 582 583 /* 584 * We don't allow simultaneous bind() calls on a single UNIX domain 585 * socket, so flag in-progress operations, and return an error if an 586 * operation is already in progress. 587 * 588 * Historically, we have not allowed a socket to be rebound, so this 589 * also returns an error. Not allowing re-binding simplifies the 590 * implementation and avoids a great many possible failure modes. 591 */ 592 UNP_PCB_LOCK(unp); 593 if (unp->unp_vnode != NULL) { 594 UNP_PCB_UNLOCK(unp); 595 return (EINVAL); 596 } 597 if (unp->unp_flags & UNP_BINDING) { 598 UNP_PCB_UNLOCK(unp); 599 return (EALREADY); 600 } 601 unp->unp_flags |= UNP_BINDING; 602 UNP_PCB_UNLOCK(unp); 603 604 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 605 bcopy(soun->sun_path, buf, namelen); 606 buf[namelen] = 0; 607 608 restart: 609 NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE, 610 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td); 611 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 612 error = namei(&nd); 613 if (error) 614 goto error; 615 vp = nd.ni_vp; 616 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 617 NDFREE(&nd, NDF_ONLY_PNBUF); 618 if (nd.ni_dvp == vp) 619 vrele(nd.ni_dvp); 620 else 621 vput(nd.ni_dvp); 622 if (vp != NULL) { 623 vrele(vp); 624 error = EADDRINUSE; 625 goto error; 626 } 627 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 628 if (error) 629 goto error; 630 goto restart; 631 } 632 VATTR_NULL(&vattr); 633 vattr.va_type = VSOCK; 634 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 635 #ifdef MAC 636 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 637 &vattr); 638 #endif 639 if (error == 0) 640 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 641 NDFREE(&nd, NDF_ONLY_PNBUF); 642 vput(nd.ni_dvp); 643 if (error) { 644 vn_finished_write(mp); 645 goto error; 646 } 647 vp = nd.ni_vp; 648 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 649 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 650 651 UNP_PCB_LOCK(unp); 652 VOP_UNP_BIND(vp, unp); 653 unp->unp_vnode = vp; 654 unp->unp_addr = soun; 655 unp->unp_flags &= ~UNP_BINDING; 656 UNP_PCB_UNLOCK(unp); 657 VOP_UNLOCK(vp, 0); 658 vn_finished_write(mp); 659 free(buf, M_TEMP); 660 return (0); 661 662 error: 663 UNP_PCB_LOCK(unp); 664 unp->unp_flags &= ~UNP_BINDING; 665 UNP_PCB_UNLOCK(unp); 666 free(buf, M_TEMP); 667 return (error); 668 } 669 670 static int 671 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 672 { 673 674 return (uipc_bindat(AT_FDCWD, so, nam, td)); 675 } 676 677 static int 678 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 679 { 680 int error; 681 682 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 683 error = unp_connect(so, nam, td); 684 return (error); 685 } 686 687 static int 688 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 689 struct thread *td) 690 { 691 int error; 692 693 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 694 error = unp_connectat(fd, so, nam, td); 695 return (error); 696 } 697 698 static void 699 uipc_close(struct socket *so) 700 { 701 struct unpcb *unp, *unp2; 702 struct vnode *vp = NULL; 703 struct mtx *vplock; 704 int freed; 705 unp = sotounpcb(so); 706 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 707 708 709 vplock = NULL; 710 if ((vp = unp->unp_vnode) != NULL) { 711 vplock = mtx_pool_find(mtxpool_sleep, vp); 712 mtx_lock(vplock); 713 } 714 UNP_PCB_LOCK(unp); 715 if (vp && unp->unp_vnode == NULL) { 716 mtx_unlock(vplock); 717 vp = NULL; 718 } 719 if (vp != NULL) { 720 VOP_UNP_DETACH(vp); 721 unp->unp_vnode = NULL; 722 } 723 unp2 = unp->unp_conn; 724 unp_pcb_hold(unp); 725 if (__predict_false(unp == unp2)) { 726 unp_disconnect(unp, unp2); 727 } else if (unp2 != NULL) { 728 unp_pcb_hold(unp2); 729 unp_pcb_owned_lock2(unp, unp2, freed); 730 unp_disconnect(unp, unp2); 731 if (unp_pcb_rele(unp2) == 0) 732 UNP_PCB_UNLOCK(unp2); 733 } 734 if (unp_pcb_rele(unp) == 0) 735 UNP_PCB_UNLOCK(unp); 736 if (vp) { 737 mtx_unlock(vplock); 738 vrele(vp); 739 } 740 } 741 742 static int 743 uipc_connect2(struct socket *so1, struct socket *so2) 744 { 745 struct unpcb *unp, *unp2; 746 int error; 747 748 unp = so1->so_pcb; 749 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 750 unp2 = so2->so_pcb; 751 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 752 if (unp != unp2) 753 unp_pcb_lock2(unp, unp2); 754 else 755 UNP_PCB_LOCK(unp); 756 error = unp_connect2(so1, so2, PRU_CONNECT2); 757 if (unp != unp2) 758 UNP_PCB_UNLOCK(unp2); 759 UNP_PCB_UNLOCK(unp); 760 return (error); 761 } 762 763 static void 764 uipc_detach(struct socket *so) 765 { 766 struct unpcb *unp, *unp2; 767 struct mtx *vplock; 768 struct sockaddr_un *saved_unp_addr; 769 struct vnode *vp; 770 int freeunp, local_unp_rights; 771 772 unp = sotounpcb(so); 773 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 774 775 vp = NULL; 776 vplock = NULL; 777 local_unp_rights = 0; 778 779 UNP_LINK_WLOCK(); 780 LIST_REMOVE(unp, unp_link); 781 unp->unp_gencnt = ++unp_gencnt; 782 --unp_count; 783 UNP_LINK_WUNLOCK(); 784 785 UNP_PCB_UNLOCK_ASSERT(unp); 786 restart: 787 if ((vp = unp->unp_vnode) != NULL) { 788 vplock = mtx_pool_find(mtxpool_sleep, vp); 789 mtx_lock(vplock); 790 } 791 UNP_PCB_LOCK(unp); 792 if (unp->unp_vnode != vp && 793 unp->unp_vnode != NULL) { 794 if (vplock) 795 mtx_unlock(vplock); 796 UNP_PCB_UNLOCK(unp); 797 goto restart; 798 } 799 if ((unp->unp_flags & UNP_NASCENT) != 0) { 800 goto teardown; 801 } 802 if ((vp = unp->unp_vnode) != NULL) { 803 VOP_UNP_DETACH(vp); 804 unp->unp_vnode = NULL; 805 } 806 if (__predict_false(unp == unp->unp_conn)) { 807 unp_disconnect(unp, unp); 808 unp2 = NULL; 809 goto connect_self; 810 } 811 if ((unp2 = unp->unp_conn) != NULL) { 812 unp_pcb_owned_lock2(unp, unp2, freeunp); 813 if (freeunp) 814 unp2 = NULL; 815 } 816 unp_pcb_hold(unp); 817 if (unp2 != NULL) { 818 unp_pcb_hold(unp2); 819 unp_disconnect(unp, unp2); 820 if (unp_pcb_rele(unp2) == 0) 821 UNP_PCB_UNLOCK(unp2); 822 } 823 connect_self: 824 UNP_PCB_UNLOCK(unp); 825 UNP_REF_LIST_LOCK(); 826 while (!LIST_EMPTY(&unp->unp_refs)) { 827 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 828 829 unp_pcb_hold(ref); 830 UNP_REF_LIST_UNLOCK(); 831 832 MPASS(ref != unp); 833 UNP_PCB_UNLOCK_ASSERT(ref); 834 unp_drop(ref); 835 UNP_REF_LIST_LOCK(); 836 } 837 838 UNP_REF_LIST_UNLOCK(); 839 UNP_PCB_LOCK(unp); 840 freeunp = unp_pcb_rele(unp); 841 MPASS(freeunp == 0); 842 local_unp_rights = unp_rights; 843 teardown: 844 unp->unp_socket->so_pcb = NULL; 845 saved_unp_addr = unp->unp_addr; 846 unp->unp_addr = NULL; 847 unp->unp_socket = NULL; 848 freeunp = unp_pcb_rele(unp); 849 if (saved_unp_addr != NULL) 850 free(saved_unp_addr, M_SONAME); 851 if (!freeunp) 852 UNP_PCB_UNLOCK(unp); 853 if (vp) { 854 mtx_unlock(vplock); 855 vrele(vp); 856 } 857 if (local_unp_rights) 858 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 859 } 860 861 static int 862 uipc_disconnect(struct socket *so) 863 { 864 struct unpcb *unp, *unp2; 865 int freed; 866 867 unp = sotounpcb(so); 868 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 869 870 UNP_PCB_LOCK(unp); 871 if ((unp2 = unp->unp_conn) == NULL) { 872 UNP_PCB_UNLOCK(unp); 873 return (0); 874 } 875 if (__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 * Send to paired receive port, and then reduce send buffer 1180 * hiwater marks to maintain backpressure. Wake up readers. 1181 */ 1182 switch (so->so_type) { 1183 case SOCK_STREAM: 1184 if (control != NULL) { 1185 if (sbappendcontrol_locked(&so2->so_rcv, m, 1186 control)) 1187 control = NULL; 1188 } else 1189 sbappend_locked(&so2->so_rcv, m, flags); 1190 break; 1191 1192 case SOCK_SEQPACKET: { 1193 const struct sockaddr *from; 1194 1195 from = &sun_noname; 1196 /* 1197 * Don't check for space available in so2->so_rcv. 1198 * Unix domain sockets only check for space in the 1199 * sending sockbuf, and that check is performed one 1200 * level up the stack. 1201 */ 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 UNP_PCB_LOCK(unp); 1307 sb->st_dev = NODEV; 1308 if (unp->unp_ino == 0) 1309 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 1310 sb->st_ino = unp->unp_ino; 1311 UNP_PCB_UNLOCK(unp); 1312 return (0); 1313 } 1314 1315 static int 1316 uipc_shutdown(struct socket *so) 1317 { 1318 struct unpcb *unp; 1319 1320 unp = sotounpcb(so); 1321 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1322 1323 UNP_PCB_LOCK(unp); 1324 socantsendmore(so); 1325 unp_shutdown(unp); 1326 UNP_PCB_UNLOCK(unp); 1327 return (0); 1328 } 1329 1330 static int 1331 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1332 { 1333 struct unpcb *unp; 1334 const struct sockaddr *sa; 1335 1336 unp = sotounpcb(so); 1337 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1338 1339 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1340 UNP_PCB_LOCK(unp); 1341 if (unp->unp_addr != NULL) 1342 sa = (struct sockaddr *) unp->unp_addr; 1343 else 1344 sa = &sun_noname; 1345 bcopy(sa, *nam, sa->sa_len); 1346 UNP_PCB_UNLOCK(unp); 1347 return (0); 1348 } 1349 1350 static struct pr_usrreqs uipc_usrreqs_dgram = { 1351 .pru_abort = uipc_abort, 1352 .pru_accept = uipc_accept, 1353 .pru_attach = uipc_attach, 1354 .pru_bind = uipc_bind, 1355 .pru_bindat = uipc_bindat, 1356 .pru_connect = uipc_connect, 1357 .pru_connectat = uipc_connectat, 1358 .pru_connect2 = uipc_connect2, 1359 .pru_detach = uipc_detach, 1360 .pru_disconnect = uipc_disconnect, 1361 .pru_listen = uipc_listen, 1362 .pru_peeraddr = uipc_peeraddr, 1363 .pru_rcvd = uipc_rcvd, 1364 .pru_send = uipc_send, 1365 .pru_sense = uipc_sense, 1366 .pru_shutdown = uipc_shutdown, 1367 .pru_sockaddr = uipc_sockaddr, 1368 .pru_soreceive = soreceive_dgram, 1369 .pru_close = uipc_close, 1370 }; 1371 1372 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1373 .pru_abort = uipc_abort, 1374 .pru_accept = uipc_accept, 1375 .pru_attach = uipc_attach, 1376 .pru_bind = uipc_bind, 1377 .pru_bindat = uipc_bindat, 1378 .pru_connect = uipc_connect, 1379 .pru_connectat = uipc_connectat, 1380 .pru_connect2 = uipc_connect2, 1381 .pru_detach = uipc_detach, 1382 .pru_disconnect = uipc_disconnect, 1383 .pru_listen = uipc_listen, 1384 .pru_peeraddr = uipc_peeraddr, 1385 .pru_rcvd = uipc_rcvd, 1386 .pru_send = uipc_send, 1387 .pru_sense = uipc_sense, 1388 .pru_shutdown = uipc_shutdown, 1389 .pru_sockaddr = uipc_sockaddr, 1390 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1391 .pru_close = uipc_close, 1392 }; 1393 1394 static struct pr_usrreqs uipc_usrreqs_stream = { 1395 .pru_abort = uipc_abort, 1396 .pru_accept = uipc_accept, 1397 .pru_attach = uipc_attach, 1398 .pru_bind = uipc_bind, 1399 .pru_bindat = uipc_bindat, 1400 .pru_connect = uipc_connect, 1401 .pru_connectat = uipc_connectat, 1402 .pru_connect2 = uipc_connect2, 1403 .pru_detach = uipc_detach, 1404 .pru_disconnect = uipc_disconnect, 1405 .pru_listen = uipc_listen, 1406 .pru_peeraddr = uipc_peeraddr, 1407 .pru_rcvd = uipc_rcvd, 1408 .pru_send = uipc_send, 1409 .pru_ready = uipc_ready, 1410 .pru_sense = uipc_sense, 1411 .pru_shutdown = uipc_shutdown, 1412 .pru_sockaddr = uipc_sockaddr, 1413 .pru_soreceive = soreceive_generic, 1414 .pru_close = uipc_close, 1415 }; 1416 1417 static int 1418 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1419 { 1420 struct unpcb *unp; 1421 struct xucred xu; 1422 int error, optval; 1423 1424 if (sopt->sopt_level != 0) 1425 return (EINVAL); 1426 1427 unp = sotounpcb(so); 1428 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1429 error = 0; 1430 switch (sopt->sopt_dir) { 1431 case SOPT_GET: 1432 switch (sopt->sopt_name) { 1433 case LOCAL_PEERCRED: 1434 UNP_PCB_LOCK(unp); 1435 if (unp->unp_flags & UNP_HAVEPC) 1436 xu = unp->unp_peercred; 1437 else { 1438 if (so->so_type == SOCK_STREAM) 1439 error = ENOTCONN; 1440 else 1441 error = EINVAL; 1442 } 1443 UNP_PCB_UNLOCK(unp); 1444 if (error == 0) 1445 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1446 break; 1447 1448 case LOCAL_CREDS: 1449 /* Unlocked read. */ 1450 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1451 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1452 break; 1453 1454 case LOCAL_CONNWAIT: 1455 /* Unlocked read. */ 1456 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1457 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1458 break; 1459 1460 default: 1461 error = EOPNOTSUPP; 1462 break; 1463 } 1464 break; 1465 1466 case SOPT_SET: 1467 switch (sopt->sopt_name) { 1468 case LOCAL_CREDS: 1469 case LOCAL_CONNWAIT: 1470 error = sooptcopyin(sopt, &optval, sizeof(optval), 1471 sizeof(optval)); 1472 if (error) 1473 break; 1474 1475 #define OPTSET(bit) do { \ 1476 UNP_PCB_LOCK(unp); \ 1477 if (optval) \ 1478 unp->unp_flags |= bit; \ 1479 else \ 1480 unp->unp_flags &= ~bit; \ 1481 UNP_PCB_UNLOCK(unp); \ 1482 } while (0) 1483 1484 switch (sopt->sopt_name) { 1485 case LOCAL_CREDS: 1486 OPTSET(UNP_WANTCRED); 1487 break; 1488 1489 case LOCAL_CONNWAIT: 1490 OPTSET(UNP_CONNWAIT); 1491 break; 1492 1493 default: 1494 break; 1495 } 1496 break; 1497 #undef OPTSET 1498 default: 1499 error = ENOPROTOOPT; 1500 break; 1501 } 1502 break; 1503 1504 default: 1505 error = EOPNOTSUPP; 1506 break; 1507 } 1508 return (error); 1509 } 1510 1511 static int 1512 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1513 { 1514 1515 return (unp_connectat(AT_FDCWD, so, nam, td)); 1516 } 1517 1518 static int 1519 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1520 struct thread *td) 1521 { 1522 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1523 struct vnode *vp; 1524 struct socket *so2; 1525 struct unpcb *unp, *unp2, *unp3; 1526 struct nameidata nd; 1527 char buf[SOCK_MAXADDRLEN]; 1528 struct sockaddr *sa; 1529 cap_rights_t rights; 1530 int error, len, freed; 1531 struct mtx *vplock; 1532 1533 if (nam->sa_family != AF_UNIX) 1534 return (EAFNOSUPPORT); 1535 if (nam->sa_len > sizeof(struct sockaddr_un)) 1536 return (EINVAL); 1537 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1538 if (len <= 0) 1539 return (EINVAL); 1540 bcopy(soun->sun_path, buf, len); 1541 buf[len] = 0; 1542 1543 unp = sotounpcb(so); 1544 UNP_PCB_LOCK(unp); 1545 if (unp->unp_flags & UNP_CONNECTING) { 1546 UNP_PCB_UNLOCK(unp); 1547 return (EALREADY); 1548 } 1549 unp->unp_flags |= UNP_CONNECTING; 1550 UNP_PCB_UNLOCK(unp); 1551 1552 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1553 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1554 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td); 1555 error = namei(&nd); 1556 if (error) 1557 vp = NULL; 1558 else 1559 vp = nd.ni_vp; 1560 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1561 NDFREE(&nd, NDF_ONLY_PNBUF); 1562 if (error) 1563 goto bad; 1564 1565 if (vp->v_type != VSOCK) { 1566 error = ENOTSOCK; 1567 goto bad; 1568 } 1569 #ifdef MAC 1570 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1571 if (error) 1572 goto bad; 1573 #endif 1574 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1575 if (error) 1576 goto bad; 1577 1578 unp = sotounpcb(so); 1579 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1580 1581 vplock = mtx_pool_find(mtxpool_sleep, vp); 1582 mtx_lock(vplock); 1583 VOP_UNP_CONNECT(vp, &unp2); 1584 if (unp2 == NULL) { 1585 error = ECONNREFUSED; 1586 goto bad2; 1587 } 1588 so2 = unp2->unp_socket; 1589 if (so->so_type != so2->so_type) { 1590 error = EPROTOTYPE; 1591 goto bad2; 1592 } 1593 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1594 if (so2->so_options & SO_ACCEPTCONN) { 1595 CURVNET_SET(so2->so_vnet); 1596 so2 = sonewconn(so2, 0); 1597 CURVNET_RESTORE(); 1598 } else 1599 so2 = NULL; 1600 if (so2 == NULL) { 1601 error = ECONNREFUSED; 1602 goto bad2; 1603 } 1604 unp3 = sotounpcb(so2); 1605 unp_pcb_lock2(unp2, unp3); 1606 if (unp2->unp_addr != NULL) { 1607 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1608 unp3->unp_addr = (struct sockaddr_un *) sa; 1609 sa = NULL; 1610 } 1611 1612 /* 1613 * The connector's (client's) credentials are copied from its 1614 * process structure at the time of connect() (which is now). 1615 */ 1616 cru2x(td->td_ucred, &unp3->unp_peercred); 1617 unp3->unp_flags |= UNP_HAVEPC; 1618 1619 /* 1620 * The receiver's (server's) credentials are copied from the 1621 * unp_peercred member of socket on which the former called 1622 * listen(); uipc_listen() cached that process's credentials 1623 * at that time so we can use them now. 1624 */ 1625 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1626 sizeof(unp->unp_peercred)); 1627 unp->unp_flags |= UNP_HAVEPC; 1628 if (unp2->unp_flags & UNP_WANTCRED) 1629 unp3->unp_flags |= UNP_WANTCRED; 1630 UNP_PCB_UNLOCK(unp2); 1631 unp2 = unp3; 1632 unp_pcb_owned_lock2(unp2, unp, freed); 1633 if (__predict_false(freed)) { 1634 UNP_PCB_UNLOCK(unp2); 1635 error = ECONNREFUSED; 1636 goto bad2; 1637 } 1638 #ifdef MAC 1639 mac_socketpeer_set_from_socket(so, so2); 1640 mac_socketpeer_set_from_socket(so2, so); 1641 #endif 1642 } else { 1643 if (unp == unp2) 1644 UNP_PCB_LOCK(unp); 1645 else 1646 unp_pcb_lock2(unp, unp2); 1647 } 1648 KASSERT(unp2 != NULL && so2 != NULL && unp2->unp_socket == so2 && 1649 sotounpcb(so2) == unp2, 1650 ("%s: unp2 %p so2 %p", __func__, unp2, so2)); 1651 error = unp_connect2(so, so2, PRU_CONNECT); 1652 if (unp != unp2) 1653 UNP_PCB_UNLOCK(unp2); 1654 UNP_PCB_UNLOCK(unp); 1655 bad2: 1656 mtx_unlock(vplock); 1657 bad: 1658 if (vp != NULL) { 1659 vput(vp); 1660 } 1661 free(sa, M_SONAME); 1662 UNP_PCB_LOCK(unp); 1663 unp->unp_flags &= ~UNP_CONNECTING; 1664 UNP_PCB_UNLOCK(unp); 1665 return (error); 1666 } 1667 1668 static int 1669 unp_connect2(struct socket *so, struct socket *so2, int req) 1670 { 1671 struct unpcb *unp; 1672 struct unpcb *unp2; 1673 1674 unp = sotounpcb(so); 1675 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1676 unp2 = sotounpcb(so2); 1677 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1678 1679 UNP_PCB_LOCK_ASSERT(unp); 1680 UNP_PCB_LOCK_ASSERT(unp2); 1681 1682 if (so2->so_type != so->so_type) 1683 return (EPROTOTYPE); 1684 unp2->unp_flags &= ~UNP_NASCENT; 1685 unp->unp_conn = unp2; 1686 unp_pcb_hold(unp2); 1687 unp_pcb_hold(unp); 1688 switch (so->so_type) { 1689 case SOCK_DGRAM: 1690 UNP_REF_LIST_LOCK(); 1691 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1692 UNP_REF_LIST_UNLOCK(); 1693 soisconnected(so); 1694 break; 1695 1696 case SOCK_STREAM: 1697 case SOCK_SEQPACKET: 1698 unp2->unp_conn = unp; 1699 if (req == PRU_CONNECT && 1700 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1701 soisconnecting(so); 1702 else 1703 soisconnected(so); 1704 soisconnected(so2); 1705 break; 1706 1707 default: 1708 panic("unp_connect2"); 1709 } 1710 return (0); 1711 } 1712 1713 static void 1714 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1715 { 1716 struct socket *so, *so2; 1717 int freed __unused; 1718 1719 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1720 1721 UNP_PCB_LOCK_ASSERT(unp); 1722 UNP_PCB_LOCK_ASSERT(unp2); 1723 1724 if (unp->unp_conn == NULL && unp2->unp_conn == NULL) 1725 return; 1726 1727 MPASS(unp->unp_conn == unp2); 1728 unp->unp_conn = NULL; 1729 so = unp->unp_socket; 1730 so2 = unp2->unp_socket; 1731 switch (unp->unp_socket->so_type) { 1732 case SOCK_DGRAM: 1733 UNP_REF_LIST_LOCK(); 1734 LIST_REMOVE(unp, unp_reflink); 1735 UNP_REF_LIST_UNLOCK(); 1736 if (so) { 1737 SOCK_LOCK(so); 1738 so->so_state &= ~SS_ISCONNECTED; 1739 SOCK_UNLOCK(so); 1740 } 1741 break; 1742 1743 case SOCK_STREAM: 1744 case SOCK_SEQPACKET: 1745 if (so) 1746 soisdisconnected(so); 1747 MPASS(unp2->unp_conn == unp); 1748 unp2->unp_conn = NULL; 1749 if (so2) 1750 soisdisconnected(so2); 1751 break; 1752 } 1753 freed = unp_pcb_rele(unp); 1754 MPASS(freed == 0); 1755 freed = unp_pcb_rele(unp2); 1756 MPASS(freed == 0); 1757 } 1758 1759 /* 1760 * unp_pcblist() walks the global list of struct unpcb's to generate a 1761 * pointer list, bumping the refcount on each unpcb. It then copies them out 1762 * sequentially, validating the generation number on each to see if it has 1763 * been detached. All of this is necessary because copyout() may sleep on 1764 * disk I/O. 1765 */ 1766 static int 1767 unp_pcblist(SYSCTL_HANDLER_ARGS) 1768 { 1769 struct unpcb *unp, **unp_list; 1770 unp_gen_t gencnt; 1771 struct xunpgen *xug; 1772 struct unp_head *head; 1773 struct xunpcb *xu; 1774 u_int i; 1775 int error, freeunp, n; 1776 1777 switch ((intptr_t)arg1) { 1778 case SOCK_STREAM: 1779 head = &unp_shead; 1780 break; 1781 1782 case SOCK_DGRAM: 1783 head = &unp_dhead; 1784 break; 1785 1786 case SOCK_SEQPACKET: 1787 head = &unp_sphead; 1788 break; 1789 1790 default: 1791 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1792 } 1793 1794 /* 1795 * The process of preparing the PCB list is too time-consuming and 1796 * resource-intensive to repeat twice on every request. 1797 */ 1798 if (req->oldptr == NULL) { 1799 n = unp_count; 1800 req->oldidx = 2 * (sizeof *xug) 1801 + (n + n/8) * sizeof(struct xunpcb); 1802 return (0); 1803 } 1804 1805 if (req->newptr != NULL) 1806 return (EPERM); 1807 1808 /* 1809 * OK, now we're committed to doing something. 1810 */ 1811 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1812 UNP_LINK_RLOCK(); 1813 gencnt = unp_gencnt; 1814 n = unp_count; 1815 UNP_LINK_RUNLOCK(); 1816 1817 xug->xug_len = sizeof *xug; 1818 xug->xug_count = n; 1819 xug->xug_gen = gencnt; 1820 xug->xug_sogen = so_gencnt; 1821 error = SYSCTL_OUT(req, xug, sizeof *xug); 1822 if (error) { 1823 free(xug, M_TEMP); 1824 return (error); 1825 } 1826 1827 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1828 1829 UNP_LINK_RLOCK(); 1830 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1831 unp = LIST_NEXT(unp, unp_link)) { 1832 UNP_PCB_LOCK(unp); 1833 if (unp->unp_gencnt <= gencnt) { 1834 if (cr_cansee(req->td->td_ucred, 1835 unp->unp_socket->so_cred)) { 1836 UNP_PCB_UNLOCK(unp); 1837 continue; 1838 } 1839 unp_list[i++] = unp; 1840 unp_pcb_hold(unp); 1841 } 1842 UNP_PCB_UNLOCK(unp); 1843 } 1844 UNP_LINK_RUNLOCK(); 1845 n = i; /* In case we lost some during malloc. */ 1846 1847 error = 0; 1848 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1849 for (i = 0; i < n; i++) { 1850 unp = unp_list[i]; 1851 UNP_PCB_LOCK(unp); 1852 freeunp = unp_pcb_rele(unp); 1853 1854 if (freeunp == 0 && unp->unp_gencnt <= gencnt) { 1855 xu->xu_len = sizeof *xu; 1856 xu->xu_unpp = unp; 1857 /* 1858 * XXX - need more locking here to protect against 1859 * connect/disconnect races for SMP. 1860 */ 1861 if (unp->unp_addr != NULL) 1862 bcopy(unp->unp_addr, &xu->xu_addr, 1863 unp->unp_addr->sun_len); 1864 else 1865 bzero(&xu->xu_addr, sizeof(xu->xu_addr)); 1866 if (unp->unp_conn != NULL && 1867 unp->unp_conn->unp_addr != NULL) 1868 bcopy(unp->unp_conn->unp_addr, 1869 &xu->xu_caddr, 1870 unp->unp_conn->unp_addr->sun_len); 1871 else 1872 bzero(&xu->xu_caddr, sizeof(xu->xu_caddr)); 1873 xu->unp_vnode = unp->unp_vnode; 1874 xu->unp_conn = unp->unp_conn; 1875 xu->xu_firstref = LIST_FIRST(&unp->unp_refs); 1876 xu->xu_nextref = LIST_NEXT(unp, unp_reflink); 1877 xu->unp_gencnt = unp->unp_gencnt; 1878 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1879 UNP_PCB_UNLOCK(unp); 1880 error = SYSCTL_OUT(req, xu, sizeof *xu); 1881 } else if (freeunp == 0) 1882 UNP_PCB_UNLOCK(unp); 1883 } 1884 free(xu, M_TEMP); 1885 if (!error) { 1886 /* 1887 * Give the user an updated idea of our state. If the 1888 * generation differs from what we told her before, she knows 1889 * that something happened while we were processing this 1890 * request, and it might be necessary to retry. 1891 */ 1892 xug->xug_gen = unp_gencnt; 1893 xug->xug_sogen = so_gencnt; 1894 xug->xug_count = unp_count; 1895 error = SYSCTL_OUT(req, xug, sizeof *xug); 1896 } 1897 free(unp_list, M_TEMP); 1898 free(xug, M_TEMP); 1899 return (error); 1900 } 1901 1902 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1903 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1904 "List of active local datagram sockets"); 1905 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1906 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1907 "List of active local stream sockets"); 1908 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1909 CTLTYPE_OPAQUE | CTLFLAG_RD, 1910 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1911 "List of active local seqpacket sockets"); 1912 1913 static void 1914 unp_shutdown(struct unpcb *unp) 1915 { 1916 struct unpcb *unp2; 1917 struct socket *so; 1918 1919 UNP_PCB_LOCK_ASSERT(unp); 1920 1921 unp2 = unp->unp_conn; 1922 if ((unp->unp_socket->so_type == SOCK_STREAM || 1923 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1924 so = unp2->unp_socket; 1925 if (so != NULL) 1926 socantrcvmore(so); 1927 } 1928 } 1929 1930 static void 1931 unp_drop(struct unpcb *unp) 1932 { 1933 struct socket *so = unp->unp_socket; 1934 struct unpcb *unp2; 1935 int freed; 1936 1937 /* 1938 * Regardless of whether the socket's peer dropped the connection 1939 * with this socket by aborting or disconnecting, POSIX requires 1940 * that ECONNRESET is returned. 1941 */ 1942 /* acquire a reference so that unp isn't freed from underneath us */ 1943 1944 UNP_PCB_LOCK(unp); 1945 if (so) 1946 so->so_error = ECONNRESET; 1947 unp2 = unp->unp_conn; 1948 if (unp2 == unp) { 1949 unp_disconnect(unp, unp2); 1950 } else if (unp2 != NULL) { 1951 unp_pcb_hold(unp2); 1952 unp_pcb_owned_lock2(unp, unp2, freed); 1953 unp_disconnect(unp, unp2); 1954 if (unp_pcb_rele(unp2) == 0) 1955 UNP_PCB_UNLOCK(unp2); 1956 } 1957 if (unp_pcb_rele(unp) == 0) 1958 UNP_PCB_UNLOCK(unp); 1959 } 1960 1961 static void 1962 unp_freerights(struct filedescent **fdep, int fdcount) 1963 { 1964 struct file *fp; 1965 int i; 1966 1967 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1968 1969 for (i = 0; i < fdcount; i++) { 1970 fp = fdep[i]->fde_file; 1971 filecaps_free(&fdep[i]->fde_caps); 1972 unp_discard(fp); 1973 } 1974 free(fdep[0], M_FILECAPS); 1975 } 1976 1977 static int 1978 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 1979 { 1980 struct thread *td = curthread; /* XXX */ 1981 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1982 int i; 1983 int *fdp; 1984 struct filedesc *fdesc = td->td_proc->p_fd; 1985 struct filedescent **fdep; 1986 void *data; 1987 socklen_t clen = control->m_len, datalen; 1988 int error, newfds; 1989 u_int newlen; 1990 1991 UNP_LINK_UNLOCK_ASSERT(); 1992 1993 error = 0; 1994 if (controlp != NULL) /* controlp == NULL => free control messages */ 1995 *controlp = NULL; 1996 while (cm != NULL) { 1997 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1998 error = EINVAL; 1999 break; 2000 } 2001 data = CMSG_DATA(cm); 2002 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2003 if (cm->cmsg_level == SOL_SOCKET 2004 && cm->cmsg_type == SCM_RIGHTS) { 2005 newfds = datalen / sizeof(*fdep); 2006 if (newfds == 0) 2007 goto next; 2008 fdep = data; 2009 2010 /* If we're not outputting the descriptors free them. */ 2011 if (error || controlp == NULL) { 2012 unp_freerights(fdep, newfds); 2013 goto next; 2014 } 2015 FILEDESC_XLOCK(fdesc); 2016 2017 /* 2018 * Now change each pointer to an fd in the global 2019 * table to an integer that is the index to the local 2020 * fd table entry that we set up to point to the 2021 * global one we are transferring. 2022 */ 2023 newlen = newfds * sizeof(int); 2024 *controlp = sbcreatecontrol(NULL, newlen, 2025 SCM_RIGHTS, SOL_SOCKET); 2026 if (*controlp == NULL) { 2027 FILEDESC_XUNLOCK(fdesc); 2028 error = E2BIG; 2029 unp_freerights(fdep, newfds); 2030 goto next; 2031 } 2032 2033 fdp = (int *) 2034 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2035 if (fdallocn(td, 0, fdp, newfds) != 0) { 2036 FILEDESC_XUNLOCK(fdesc); 2037 error = EMSGSIZE; 2038 unp_freerights(fdep, newfds); 2039 m_freem(*controlp); 2040 *controlp = NULL; 2041 goto next; 2042 } 2043 for (i = 0; i < newfds; i++, fdp++) { 2044 _finstall(fdesc, fdep[i]->fde_file, *fdp, 2045 (flags & MSG_CMSG_CLOEXEC) != 0 ? UF_EXCLOSE : 0, 2046 &fdep[i]->fde_caps); 2047 unp_externalize_fp(fdep[i]->fde_file); 2048 } 2049 FILEDESC_XUNLOCK(fdesc); 2050 free(fdep[0], M_FILECAPS); 2051 } else { 2052 /* We can just copy anything else across. */ 2053 if (error || controlp == NULL) 2054 goto next; 2055 *controlp = sbcreatecontrol(NULL, datalen, 2056 cm->cmsg_type, cm->cmsg_level); 2057 if (*controlp == NULL) { 2058 error = ENOBUFS; 2059 goto next; 2060 } 2061 bcopy(data, 2062 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 2063 datalen); 2064 } 2065 controlp = &(*controlp)->m_next; 2066 2067 next: 2068 if (CMSG_SPACE(datalen) < clen) { 2069 clen -= CMSG_SPACE(datalen); 2070 cm = (struct cmsghdr *) 2071 ((caddr_t)cm + CMSG_SPACE(datalen)); 2072 } else { 2073 clen = 0; 2074 cm = NULL; 2075 } 2076 } 2077 2078 m_freem(control); 2079 return (error); 2080 } 2081 2082 static void 2083 unp_zone_change(void *tag) 2084 { 2085 2086 uma_zone_set_max(unp_zone, maxsockets); 2087 } 2088 2089 static void 2090 unp_init(void) 2091 { 2092 2093 #ifdef VIMAGE 2094 if (!IS_DEFAULT_VNET(curvnet)) 2095 return; 2096 #endif 2097 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 2098 NULL, NULL, UMA_ALIGN_CACHE, 0); 2099 if (unp_zone == NULL) 2100 panic("unp_init"); 2101 uma_zone_set_max(unp_zone, maxsockets); 2102 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 2103 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 2104 NULL, EVENTHANDLER_PRI_ANY); 2105 LIST_INIT(&unp_dhead); 2106 LIST_INIT(&unp_shead); 2107 LIST_INIT(&unp_sphead); 2108 SLIST_INIT(&unp_defers); 2109 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 2110 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 2111 UNP_LINK_LOCK_INIT(); 2112 UNP_DEFERRED_LOCK_INIT(); 2113 } 2114 2115 static int 2116 unp_internalize(struct mbuf **controlp, struct thread *td) 2117 { 2118 struct mbuf *control = *controlp; 2119 struct proc *p = td->td_proc; 2120 struct filedesc *fdesc = p->p_fd; 2121 struct bintime *bt; 2122 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 2123 struct cmsgcred *cmcred; 2124 struct filedescent *fde, **fdep, *fdev; 2125 struct file *fp; 2126 struct timeval *tv; 2127 struct timespec *ts; 2128 int i, *fdp; 2129 void *data; 2130 socklen_t clen = control->m_len, datalen; 2131 int error, oldfds; 2132 u_int newlen; 2133 2134 UNP_LINK_UNLOCK_ASSERT(); 2135 2136 error = 0; 2137 *controlp = NULL; 2138 while (cm != NULL) { 2139 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 2140 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 2141 error = EINVAL; 2142 goto out; 2143 } 2144 data = CMSG_DATA(cm); 2145 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 2146 2147 switch (cm->cmsg_type) { 2148 /* 2149 * Fill in credential information. 2150 */ 2151 case SCM_CREDS: 2152 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 2153 SCM_CREDS, SOL_SOCKET); 2154 if (*controlp == NULL) { 2155 error = ENOBUFS; 2156 goto out; 2157 } 2158 cmcred = (struct cmsgcred *) 2159 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2160 cmcred->cmcred_pid = p->p_pid; 2161 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 2162 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 2163 cmcred->cmcred_euid = td->td_ucred->cr_uid; 2164 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 2165 CMGROUP_MAX); 2166 for (i = 0; i < cmcred->cmcred_ngroups; i++) 2167 cmcred->cmcred_groups[i] = 2168 td->td_ucred->cr_groups[i]; 2169 break; 2170 2171 case SCM_RIGHTS: 2172 oldfds = datalen / sizeof (int); 2173 if (oldfds == 0) 2174 break; 2175 /* 2176 * Check that all the FDs passed in refer to legal 2177 * files. If not, reject the entire operation. 2178 */ 2179 fdp = data; 2180 FILEDESC_SLOCK(fdesc); 2181 for (i = 0; i < oldfds; i++, fdp++) { 2182 fp = fget_locked(fdesc, *fdp); 2183 if (fp == NULL) { 2184 FILEDESC_SUNLOCK(fdesc); 2185 error = EBADF; 2186 goto out; 2187 } 2188 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 2189 FILEDESC_SUNLOCK(fdesc); 2190 error = EOPNOTSUPP; 2191 goto out; 2192 } 2193 2194 } 2195 2196 /* 2197 * Now replace the integer FDs with pointers to the 2198 * file structure and capability rights. 2199 */ 2200 newlen = oldfds * sizeof(fdep[0]); 2201 *controlp = sbcreatecontrol(NULL, newlen, 2202 SCM_RIGHTS, SOL_SOCKET); 2203 if (*controlp == NULL) { 2204 FILEDESC_SUNLOCK(fdesc); 2205 error = E2BIG; 2206 goto out; 2207 } 2208 fdp = data; 2209 fdep = (struct filedescent **) 2210 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2211 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 2212 M_WAITOK); 2213 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 2214 fde = &fdesc->fd_ofiles[*fdp]; 2215 fdep[i] = fdev; 2216 fdep[i]->fde_file = fde->fde_file; 2217 filecaps_copy(&fde->fde_caps, 2218 &fdep[i]->fde_caps, true); 2219 unp_internalize_fp(fdep[i]->fde_file); 2220 } 2221 FILEDESC_SUNLOCK(fdesc); 2222 break; 2223 2224 case SCM_TIMESTAMP: 2225 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 2226 SCM_TIMESTAMP, SOL_SOCKET); 2227 if (*controlp == NULL) { 2228 error = ENOBUFS; 2229 goto out; 2230 } 2231 tv = (struct timeval *) 2232 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2233 microtime(tv); 2234 break; 2235 2236 case SCM_BINTIME: 2237 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 2238 SCM_BINTIME, SOL_SOCKET); 2239 if (*controlp == NULL) { 2240 error = ENOBUFS; 2241 goto out; 2242 } 2243 bt = (struct bintime *) 2244 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2245 bintime(bt); 2246 break; 2247 2248 case SCM_REALTIME: 2249 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2250 SCM_REALTIME, SOL_SOCKET); 2251 if (*controlp == NULL) { 2252 error = ENOBUFS; 2253 goto out; 2254 } 2255 ts = (struct timespec *) 2256 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2257 nanotime(ts); 2258 break; 2259 2260 case SCM_MONOTONIC: 2261 *controlp = sbcreatecontrol(NULL, sizeof(*ts), 2262 SCM_MONOTONIC, SOL_SOCKET); 2263 if (*controlp == NULL) { 2264 error = ENOBUFS; 2265 goto out; 2266 } 2267 ts = (struct timespec *) 2268 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2269 nanouptime(ts); 2270 break; 2271 2272 default: 2273 error = EINVAL; 2274 goto out; 2275 } 2276 2277 controlp = &(*controlp)->m_next; 2278 if (CMSG_SPACE(datalen) < clen) { 2279 clen -= CMSG_SPACE(datalen); 2280 cm = (struct cmsghdr *) 2281 ((caddr_t)cm + CMSG_SPACE(datalen)); 2282 } else { 2283 clen = 0; 2284 cm = NULL; 2285 } 2286 } 2287 2288 out: 2289 m_freem(control); 2290 return (error); 2291 } 2292 2293 static struct mbuf * 2294 unp_addsockcred(struct thread *td, struct mbuf *control) 2295 { 2296 struct mbuf *m, *n, *n_prev; 2297 struct sockcred *sc; 2298 const struct cmsghdr *cm; 2299 int ngroups; 2300 int i; 2301 2302 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2303 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 2304 if (m == NULL) 2305 return (control); 2306 2307 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 2308 sc->sc_uid = td->td_ucred->cr_ruid; 2309 sc->sc_euid = td->td_ucred->cr_uid; 2310 sc->sc_gid = td->td_ucred->cr_rgid; 2311 sc->sc_egid = td->td_ucred->cr_gid; 2312 sc->sc_ngroups = ngroups; 2313 for (i = 0; i < sc->sc_ngroups; i++) 2314 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2315 2316 /* 2317 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2318 * created SCM_CREDS control message (struct sockcred) has another 2319 * format. 2320 */ 2321 if (control != NULL) 2322 for (n = control, n_prev = NULL; n != NULL;) { 2323 cm = mtod(n, struct cmsghdr *); 2324 if (cm->cmsg_level == SOL_SOCKET && 2325 cm->cmsg_type == SCM_CREDS) { 2326 if (n_prev == NULL) 2327 control = n->m_next; 2328 else 2329 n_prev->m_next = n->m_next; 2330 n = m_free(n); 2331 } else { 2332 n_prev = n; 2333 n = n->m_next; 2334 } 2335 } 2336 2337 /* Prepend it to the head. */ 2338 m->m_next = control; 2339 return (m); 2340 } 2341 2342 static struct unpcb * 2343 fptounp(struct file *fp) 2344 { 2345 struct socket *so; 2346 2347 if (fp->f_type != DTYPE_SOCKET) 2348 return (NULL); 2349 if ((so = fp->f_data) == NULL) 2350 return (NULL); 2351 if (so->so_proto->pr_domain != &localdomain) 2352 return (NULL); 2353 return sotounpcb(so); 2354 } 2355 2356 static void 2357 unp_discard(struct file *fp) 2358 { 2359 struct unp_defer *dr; 2360 2361 if (unp_externalize_fp(fp)) { 2362 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2363 dr->ud_fp = fp; 2364 UNP_DEFERRED_LOCK(); 2365 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2366 UNP_DEFERRED_UNLOCK(); 2367 atomic_add_int(&unp_defers_count, 1); 2368 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2369 } else 2370 (void) closef(fp, (struct thread *)NULL); 2371 } 2372 2373 static void 2374 unp_process_defers(void *arg __unused, int pending) 2375 { 2376 struct unp_defer *dr; 2377 SLIST_HEAD(, unp_defer) drl; 2378 int count; 2379 2380 SLIST_INIT(&drl); 2381 for (;;) { 2382 UNP_DEFERRED_LOCK(); 2383 if (SLIST_FIRST(&unp_defers) == NULL) { 2384 UNP_DEFERRED_UNLOCK(); 2385 break; 2386 } 2387 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2388 UNP_DEFERRED_UNLOCK(); 2389 count = 0; 2390 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2391 SLIST_REMOVE_HEAD(&drl, ud_link); 2392 closef(dr->ud_fp, NULL); 2393 free(dr, M_TEMP); 2394 count++; 2395 } 2396 atomic_add_int(&unp_defers_count, -count); 2397 } 2398 } 2399 2400 static void 2401 unp_internalize_fp(struct file *fp) 2402 { 2403 struct unpcb *unp; 2404 2405 UNP_LINK_WLOCK(); 2406 if ((unp = fptounp(fp)) != NULL) { 2407 unp->unp_file = fp; 2408 unp->unp_msgcount++; 2409 } 2410 fhold(fp); 2411 unp_rights++; 2412 UNP_LINK_WUNLOCK(); 2413 } 2414 2415 static int 2416 unp_externalize_fp(struct file *fp) 2417 { 2418 struct unpcb *unp; 2419 int ret; 2420 2421 UNP_LINK_WLOCK(); 2422 if ((unp = fptounp(fp)) != NULL) { 2423 unp->unp_msgcount--; 2424 ret = 1; 2425 } else 2426 ret = 0; 2427 unp_rights--; 2428 UNP_LINK_WUNLOCK(); 2429 return (ret); 2430 } 2431 2432 /* 2433 * unp_defer indicates whether additional work has been defered for a future 2434 * pass through unp_gc(). It is thread local and does not require explicit 2435 * synchronization. 2436 */ 2437 static int unp_marked; 2438 static int unp_unreachable; 2439 2440 static void 2441 unp_accessable(struct filedescent **fdep, int fdcount) 2442 { 2443 struct unpcb *unp; 2444 struct file *fp; 2445 int i; 2446 2447 for (i = 0; i < fdcount; i++) { 2448 fp = fdep[i]->fde_file; 2449 if ((unp = fptounp(fp)) == NULL) 2450 continue; 2451 if (unp->unp_gcflag & UNPGC_REF) 2452 continue; 2453 unp->unp_gcflag &= ~UNPGC_DEAD; 2454 unp->unp_gcflag |= UNPGC_REF; 2455 unp_marked++; 2456 } 2457 } 2458 2459 static void 2460 unp_gc_process(struct unpcb *unp) 2461 { 2462 struct socket *so, *soa; 2463 struct file *fp; 2464 2465 /* Already processed. */ 2466 if (unp->unp_gcflag & UNPGC_SCANNED) 2467 return; 2468 fp = unp->unp_file; 2469 2470 /* 2471 * Check for a socket potentially in a cycle. It must be in a 2472 * queue as indicated by msgcount, and this must equal the file 2473 * reference count. Note that when msgcount is 0 the file is NULL. 2474 */ 2475 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2476 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2477 unp->unp_gcflag |= UNPGC_DEAD; 2478 unp_unreachable++; 2479 return; 2480 } 2481 2482 so = unp->unp_socket; 2483 SOCK_LOCK(so); 2484 if (SOLISTENING(so)) { 2485 /* 2486 * Mark all sockets in our accept queue. 2487 */ 2488 TAILQ_FOREACH(soa, &so->sol_comp, so_list) { 2489 if (sotounpcb(soa)->unp_gcflag & UNPGC_IGNORE_RIGHTS) 2490 continue; 2491 SOCKBUF_LOCK(&soa->so_rcv); 2492 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2493 SOCKBUF_UNLOCK(&soa->so_rcv); 2494 } 2495 } else { 2496 /* 2497 * Mark all sockets we reference with RIGHTS. 2498 */ 2499 if ((unp->unp_gcflag & UNPGC_IGNORE_RIGHTS) == 0) { 2500 SOCKBUF_LOCK(&so->so_rcv); 2501 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2502 SOCKBUF_UNLOCK(&so->so_rcv); 2503 } 2504 } 2505 SOCK_UNLOCK(so); 2506 unp->unp_gcflag |= UNPGC_SCANNED; 2507 } 2508 2509 static int unp_recycled; 2510 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2511 "Number of unreachable sockets claimed by the garbage collector."); 2512 2513 static int unp_taskcount; 2514 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2515 "Number of times the garbage collector has run."); 2516 2517 static void 2518 unp_gc(__unused void *arg, int pending) 2519 { 2520 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2521 NULL }; 2522 struct unp_head **head; 2523 struct file *f, **unref; 2524 struct unpcb *unp; 2525 int i, total; 2526 2527 unp_taskcount++; 2528 UNP_LINK_RLOCK(); 2529 /* 2530 * First clear all gc flags from previous runs, apart from 2531 * UNPGC_IGNORE_RIGHTS. 2532 */ 2533 for (head = heads; *head != NULL; head++) 2534 LIST_FOREACH(unp, *head, unp_link) 2535 unp->unp_gcflag = 2536 (unp->unp_gcflag & UNPGC_IGNORE_RIGHTS); 2537 2538 /* 2539 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2540 * is reachable all of the sockets it references are reachable. 2541 * Stop the scan once we do a complete loop without discovering 2542 * a new reachable socket. 2543 */ 2544 do { 2545 unp_unreachable = 0; 2546 unp_marked = 0; 2547 for (head = heads; *head != NULL; head++) 2548 LIST_FOREACH(unp, *head, unp_link) 2549 unp_gc_process(unp); 2550 } while (unp_marked); 2551 UNP_LINK_RUNLOCK(); 2552 if (unp_unreachable == 0) 2553 return; 2554 2555 /* 2556 * Allocate space for a local list of dead unpcbs. 2557 */ 2558 unref = malloc(unp_unreachable * sizeof(struct file *), 2559 M_TEMP, M_WAITOK); 2560 2561 /* 2562 * Iterate looking for sockets which have been specifically marked 2563 * as as unreachable and store them locally. 2564 */ 2565 UNP_LINK_RLOCK(); 2566 for (total = 0, head = heads; *head != NULL; head++) 2567 LIST_FOREACH(unp, *head, unp_link) 2568 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2569 f = unp->unp_file; 2570 if (unp->unp_msgcount == 0 || f == NULL || 2571 f->f_count != unp->unp_msgcount) 2572 continue; 2573 unref[total++] = f; 2574 fhold(f); 2575 KASSERT(total <= unp_unreachable, 2576 ("unp_gc: incorrect unreachable count.")); 2577 } 2578 UNP_LINK_RUNLOCK(); 2579 2580 /* 2581 * Now flush all sockets, free'ing rights. This will free the 2582 * struct files associated with these sockets but leave each socket 2583 * with one remaining ref. 2584 */ 2585 for (i = 0; i < total; i++) { 2586 struct socket *so; 2587 2588 so = unref[i]->f_data; 2589 CURVNET_SET(so->so_vnet); 2590 sorflush(so); 2591 CURVNET_RESTORE(); 2592 } 2593 2594 /* 2595 * And finally release the sockets so they can be reclaimed. 2596 */ 2597 for (i = 0; i < total; i++) 2598 fdrop(unref[i], NULL); 2599 unp_recycled += total; 2600 free(unref, M_TEMP); 2601 } 2602 2603 static void 2604 unp_dispose_mbuf(struct mbuf *m) 2605 { 2606 2607 if (m) 2608 unp_scan(m, unp_freerights); 2609 } 2610 2611 /* 2612 * Synchronize against unp_gc, which can trip over data as we are freeing it. 2613 */ 2614 static void 2615 unp_dispose(struct socket *so) 2616 { 2617 struct unpcb *unp; 2618 2619 unp = sotounpcb(so); 2620 UNP_LINK_WLOCK(); 2621 unp->unp_gcflag |= UNPGC_IGNORE_RIGHTS; 2622 UNP_LINK_WUNLOCK(); 2623 if (!SOLISTENING(so)) 2624 unp_dispose_mbuf(so->so_rcv.sb_mb); 2625 } 2626 2627 static void 2628 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2629 { 2630 struct mbuf *m; 2631 struct cmsghdr *cm; 2632 void *data; 2633 socklen_t clen, datalen; 2634 2635 while (m0 != NULL) { 2636 for (m = m0; m; m = m->m_next) { 2637 if (m->m_type != MT_CONTROL) 2638 continue; 2639 2640 cm = mtod(m, struct cmsghdr *); 2641 clen = m->m_len; 2642 2643 while (cm != NULL) { 2644 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2645 break; 2646 2647 data = CMSG_DATA(cm); 2648 datalen = (caddr_t)cm + cm->cmsg_len 2649 - (caddr_t)data; 2650 2651 if (cm->cmsg_level == SOL_SOCKET && 2652 cm->cmsg_type == SCM_RIGHTS) { 2653 (*op)(data, datalen / 2654 sizeof(struct filedescent *)); 2655 } 2656 2657 if (CMSG_SPACE(datalen) < clen) { 2658 clen -= CMSG_SPACE(datalen); 2659 cm = (struct cmsghdr *) 2660 ((caddr_t)cm + CMSG_SPACE(datalen)); 2661 } else { 2662 clen = 0; 2663 cm = NULL; 2664 } 2665 } 2666 } 2667 m0 = m0->m_nextpkt; 2668 } 2669 } 2670 2671 /* 2672 * A helper function called by VFS before socket-type vnode reclamation. 2673 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2674 * use count. 2675 */ 2676 void 2677 vfs_unp_reclaim(struct vnode *vp) 2678 { 2679 struct unpcb *unp; 2680 int active; 2681 struct mtx *vplock; 2682 2683 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2684 KASSERT(vp->v_type == VSOCK, 2685 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2686 2687 active = 0; 2688 vplock = mtx_pool_find(mtxpool_sleep, vp); 2689 mtx_lock(vplock); 2690 VOP_UNP_CONNECT(vp, &unp); 2691 if (unp == NULL) 2692 goto done; 2693 UNP_PCB_LOCK(unp); 2694 if (unp->unp_vnode == vp) { 2695 VOP_UNP_DETACH(vp); 2696 unp->unp_vnode = NULL; 2697 active = 1; 2698 } 2699 UNP_PCB_UNLOCK(unp); 2700 done: 2701 mtx_unlock(vplock); 2702 if (active) 2703 vunref(vp); 2704 } 2705 2706 #ifdef DDB 2707 static void 2708 db_print_indent(int indent) 2709 { 2710 int i; 2711 2712 for (i = 0; i < indent; i++) 2713 db_printf(" "); 2714 } 2715 2716 static void 2717 db_print_unpflags(int unp_flags) 2718 { 2719 int comma; 2720 2721 comma = 0; 2722 if (unp_flags & UNP_HAVEPC) { 2723 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2724 comma = 1; 2725 } 2726 if (unp_flags & UNP_WANTCRED) { 2727 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2728 comma = 1; 2729 } 2730 if (unp_flags & UNP_CONNWAIT) { 2731 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2732 comma = 1; 2733 } 2734 if (unp_flags & UNP_CONNECTING) { 2735 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2736 comma = 1; 2737 } 2738 if (unp_flags & UNP_BINDING) { 2739 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2740 comma = 1; 2741 } 2742 } 2743 2744 static void 2745 db_print_xucred(int indent, struct xucred *xu) 2746 { 2747 int comma, i; 2748 2749 db_print_indent(indent); 2750 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2751 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2752 db_print_indent(indent); 2753 db_printf("cr_groups: "); 2754 comma = 0; 2755 for (i = 0; i < xu->cr_ngroups; i++) { 2756 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2757 comma = 1; 2758 } 2759 db_printf("\n"); 2760 } 2761 2762 static void 2763 db_print_unprefs(int indent, struct unp_head *uh) 2764 { 2765 struct unpcb *unp; 2766 int counter; 2767 2768 counter = 0; 2769 LIST_FOREACH(unp, uh, unp_reflink) { 2770 if (counter % 4 == 0) 2771 db_print_indent(indent); 2772 db_printf("%p ", unp); 2773 if (counter % 4 == 3) 2774 db_printf("\n"); 2775 counter++; 2776 } 2777 if (counter != 0 && counter % 4 != 0) 2778 db_printf("\n"); 2779 } 2780 2781 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2782 { 2783 struct unpcb *unp; 2784 2785 if (!have_addr) { 2786 db_printf("usage: show unpcb <addr>\n"); 2787 return; 2788 } 2789 unp = (struct unpcb *)addr; 2790 2791 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2792 unp->unp_vnode); 2793 2794 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2795 unp->unp_conn); 2796 2797 db_printf("unp_refs:\n"); 2798 db_print_unprefs(2, &unp->unp_refs); 2799 2800 /* XXXRW: Would be nice to print the full address, if any. */ 2801 db_printf("unp_addr: %p\n", unp->unp_addr); 2802 2803 db_printf("unp_gencnt: %llu\n", 2804 (unsigned long long)unp->unp_gencnt); 2805 2806 db_printf("unp_flags: %x (", unp->unp_flags); 2807 db_print_unpflags(unp->unp_flags); 2808 db_printf(")\n"); 2809 2810 db_printf("unp_peercred:\n"); 2811 db_print_xucred(2, &unp->unp_peercred); 2812 2813 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2814 } 2815 #endif 2816