1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. 4 * Copyright (c) 2004-2009 Robert N. M. Watson 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 4. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 32 */ 33 34 /* 35 * UNIX Domain (Local) Sockets 36 * 37 * This is an implementation of UNIX (local) domain sockets. Each socket has 38 * an associated struct unpcb (UNIX protocol control block). Stream sockets 39 * may be connected to 0 or 1 other socket. Datagram sockets may be 40 * connected to 0, 1, or many other sockets. Sockets may be created and 41 * connected in pairs (socketpair(2)), or bound/connected to using the file 42 * system name space. For most purposes, only the receive socket buffer is 43 * used, as sending on one socket delivers directly to the receive socket 44 * buffer of a second socket. 45 * 46 * The implementation is substantially complicated by the fact that 47 * "ancillary data", such as file descriptors or credentials, may be passed 48 * across UNIX domain sockets. The potential for passing UNIX domain sockets 49 * over other UNIX domain sockets requires the implementation of a simple 50 * garbage collector to find and tear down cycles of disconnected sockets. 51 * 52 * TODO: 53 * RDM 54 * rethink name space problems 55 * need a proper out-of-band 56 */ 57 58 #include <sys/cdefs.h> 59 __FBSDID("$FreeBSD$"); 60 61 #include "opt_ddb.h" 62 63 #include <sys/param.h> 64 #include <sys/capsicum.h> 65 #include <sys/domain.h> 66 #include <sys/fcntl.h> 67 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 68 #include <sys/eventhandler.h> 69 #include <sys/file.h> 70 #include <sys/filedesc.h> 71 #include <sys/kernel.h> 72 #include <sys/lock.h> 73 #include <sys/mbuf.h> 74 #include <sys/mount.h> 75 #include <sys/mutex.h> 76 #include <sys/namei.h> 77 #include <sys/proc.h> 78 #include <sys/protosw.h> 79 #include <sys/queue.h> 80 #include <sys/resourcevar.h> 81 #include <sys/rwlock.h> 82 #include <sys/socket.h> 83 #include <sys/socketvar.h> 84 #include <sys/signalvar.h> 85 #include <sys/stat.h> 86 #include <sys/sx.h> 87 #include <sys/sysctl.h> 88 #include <sys/systm.h> 89 #include <sys/taskqueue.h> 90 #include <sys/un.h> 91 #include <sys/unpcb.h> 92 #include <sys/vnode.h> 93 94 #include <net/vnet.h> 95 96 #ifdef DDB 97 #include <ddb/ddb.h> 98 #endif 99 100 #include <security/mac/mac_framework.h> 101 102 #include <vm/uma.h> 103 104 MALLOC_DECLARE(M_FILECAPS); 105 106 /* 107 * Locking key: 108 * (l) Locked using list lock 109 * (g) Locked using linkage lock 110 */ 111 112 static uma_zone_t unp_zone; 113 static unp_gen_t unp_gencnt; /* (l) */ 114 static u_int unp_count; /* (l) Count of local sockets. */ 115 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 116 static int unp_rights; /* (g) File descriptors in flight. */ 117 static struct unp_head unp_shead; /* (l) List of stream sockets. */ 118 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 119 static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */ 120 121 struct unp_defer { 122 SLIST_ENTRY(unp_defer) ud_link; 123 struct file *ud_fp; 124 }; 125 static SLIST_HEAD(, unp_defer) unp_defers; 126 static int unp_defers_count; 127 128 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 129 130 /* 131 * Garbage collection of cyclic file descriptor/socket references occurs 132 * asynchronously in a taskqueue context in order to avoid recursion and 133 * reentrance in the UNIX domain socket, file descriptor, and socket layer 134 * code. See unp_gc() for a full description. 135 */ 136 static struct timeout_task unp_gc_task; 137 138 /* 139 * The close of unix domain sockets attached as SCM_RIGHTS is 140 * postponed to the taskqueue, to avoid arbitrary recursion depth. 141 * The attached sockets might have another sockets attached. 142 */ 143 static struct task unp_defer_task; 144 145 /* 146 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 147 * stream sockets, although the total for sender and receiver is actually 148 * only PIPSIZ. 149 * 150 * Datagram sockets really use the sendspace as the maximum datagram size, 151 * and don't really want to reserve the sendspace. Their recvspace should be 152 * large enough for at least one max-size datagram plus address. 153 */ 154 #ifndef PIPSIZ 155 #define PIPSIZ 8192 156 #endif 157 static u_long unpst_sendspace = PIPSIZ; 158 static u_long unpst_recvspace = PIPSIZ; 159 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 160 static u_long unpdg_recvspace = 4*1024; 161 static u_long unpsp_sendspace = PIPSIZ; /* really max datagram size */ 162 static u_long unpsp_recvspace = PIPSIZ; 163 164 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain"); 165 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, 166 "SOCK_STREAM"); 167 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM"); 168 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, CTLFLAG_RW, 0, 169 "SOCK_SEQPACKET"); 170 171 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 172 &unpst_sendspace, 0, "Default stream send space."); 173 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 174 &unpst_recvspace, 0, "Default stream receive space."); 175 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 176 &unpdg_sendspace, 0, "Default datagram send space."); 177 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 178 &unpdg_recvspace, 0, "Default datagram receive space."); 179 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW, 180 &unpsp_sendspace, 0, "Default seqpacket send space."); 181 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW, 182 &unpsp_recvspace, 0, "Default seqpacket receive space."); 183 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 184 "File descriptors in flight."); 185 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD, 186 &unp_defers_count, 0, 187 "File descriptors deferred to taskqueue for close."); 188 189 /* 190 * Locking and synchronization: 191 * 192 * Three types of locks exit in the local domain socket implementation: a 193 * global list mutex, a global linkage rwlock, and per-unpcb mutexes. Of the 194 * global locks, the list lock protects the socket count, global generation 195 * number, and stream/datagram global lists. The linkage lock protects the 196 * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be 197 * held exclusively over the acquisition of multiple unpcb locks to prevent 198 * deadlock. 199 * 200 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 201 * allocated in pru_attach() and freed in pru_detach(). The validity of that 202 * pointer is an invariant, so no lock is required to dereference the so_pcb 203 * pointer if a valid socket reference is held by the caller. In practice, 204 * this is always true during operations performed on a socket. Each unpcb 205 * has a back-pointer to its socket, unp_socket, which will be stable under 206 * the same circumstances. 207 * 208 * This pointer may only be safely dereferenced as long as a valid reference 209 * to the unpcb is held. Typically, this reference will be from the socket, 210 * or from another unpcb when the referring unpcb's lock is held (in order 211 * that the reference not be invalidated during use). For example, to follow 212 * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn, 213 * as unp_socket remains valid as long as the reference to unp_conn is valid. 214 * 215 * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual 216 * atomic reads without the lock may be performed "lockless", but more 217 * complex reads and read-modify-writes require the mutex to be held. No 218 * lock order is defined between unpcb locks -- multiple unpcb locks may be 219 * acquired at the same time only when holding the linkage rwlock 220 * exclusively, which prevents deadlocks. 221 * 222 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 223 * protocols, bind() is a non-atomic operation, and connect() requires 224 * potential sleeping in the protocol, due to potentially waiting on local or 225 * distributed file systems. We try to separate "lookup" operations, which 226 * may sleep, and the IPC operations themselves, which typically can occur 227 * with relative atomicity as locks can be held over the entire operation. 228 * 229 * Another tricky issue is simultaneous multi-threaded or multi-process 230 * access to a single UNIX domain socket. These are handled by the flags 231 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 232 * binding, both of which involve dropping UNIX domain socket locks in order 233 * to perform namei() and other file system operations. 234 */ 235 static struct rwlock unp_link_rwlock; 236 static struct mtx unp_list_lock; 237 static struct mtx unp_defers_lock; 238 239 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 240 "unp_link_rwlock") 241 242 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 243 RA_LOCKED) 244 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 245 RA_UNLOCKED) 246 247 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 248 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 249 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 250 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 251 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 252 RA_WLOCKED) 253 254 #define UNP_LIST_LOCK_INIT() mtx_init(&unp_list_lock, \ 255 "unp_list_lock", NULL, MTX_DEF) 256 #define UNP_LIST_LOCK() mtx_lock(&unp_list_lock) 257 #define UNP_LIST_UNLOCK() mtx_unlock(&unp_list_lock) 258 259 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \ 260 "unp_defer", NULL, MTX_DEF) 261 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock) 262 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock) 263 264 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 265 "unp_mtx", "unp_mtx", \ 266 MTX_DUPOK|MTX_DEF|MTX_RECURSE) 267 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 268 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 269 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 270 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 271 272 static int uipc_connect2(struct socket *, struct socket *); 273 static int uipc_ctloutput(struct socket *, struct sockopt *); 274 static int unp_connect(struct socket *, struct sockaddr *, 275 struct thread *); 276 static int unp_connectat(int, struct socket *, struct sockaddr *, 277 struct thread *); 278 static int unp_connect2(struct socket *so, struct socket *so2, int); 279 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 280 static void unp_dispose(struct mbuf *); 281 static void unp_shutdown(struct unpcb *); 282 static void unp_drop(struct unpcb *, int); 283 static void unp_gc(__unused void *, int); 284 static void unp_scan(struct mbuf *, void (*)(struct filedescent **, int)); 285 static void unp_discard(struct file *); 286 static void unp_freerights(struct filedescent **, int); 287 static void unp_init(void); 288 static int unp_internalize(struct mbuf **, struct thread *); 289 static void unp_internalize_fp(struct file *); 290 static int unp_externalize(struct mbuf *, struct mbuf **, int); 291 static int unp_externalize_fp(struct file *); 292 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 293 static void unp_process_defers(void * __unused, int); 294 295 /* 296 * Definitions of protocols supported in the LOCAL domain. 297 */ 298 static struct domain localdomain; 299 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 300 static struct pr_usrreqs uipc_usrreqs_seqpacket; 301 static struct protosw localsw[] = { 302 { 303 .pr_type = SOCK_STREAM, 304 .pr_domain = &localdomain, 305 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 306 .pr_ctloutput = &uipc_ctloutput, 307 .pr_usrreqs = &uipc_usrreqs_stream 308 }, 309 { 310 .pr_type = SOCK_DGRAM, 311 .pr_domain = &localdomain, 312 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 313 .pr_ctloutput = &uipc_ctloutput, 314 .pr_usrreqs = &uipc_usrreqs_dgram 315 }, 316 { 317 .pr_type = SOCK_SEQPACKET, 318 .pr_domain = &localdomain, 319 320 /* 321 * XXXRW: For now, PR_ADDR because soreceive will bump into them 322 * due to our use of sbappendaddr. A new sbappend variants is needed 323 * that supports both atomic record writes and control data. 324 */ 325 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD| 326 PR_RIGHTS, 327 .pr_ctloutput = &uipc_ctloutput, 328 .pr_usrreqs = &uipc_usrreqs_seqpacket, 329 }, 330 }; 331 332 static struct domain localdomain = { 333 .dom_family = AF_LOCAL, 334 .dom_name = "local", 335 .dom_init = unp_init, 336 .dom_externalize = unp_externalize, 337 .dom_dispose = unp_dispose, 338 .dom_protosw = localsw, 339 .dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])] 340 }; 341 DOMAIN_SET(local); 342 343 static void 344 uipc_abort(struct socket *so) 345 { 346 struct unpcb *unp, *unp2; 347 348 unp = sotounpcb(so); 349 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 350 351 UNP_LINK_WLOCK(); 352 UNP_PCB_LOCK(unp); 353 unp2 = unp->unp_conn; 354 if (unp2 != NULL) { 355 UNP_PCB_LOCK(unp2); 356 unp_drop(unp2, ECONNABORTED); 357 UNP_PCB_UNLOCK(unp2); 358 } 359 UNP_PCB_UNLOCK(unp); 360 UNP_LINK_WUNLOCK(); 361 } 362 363 static int 364 uipc_accept(struct socket *so, struct sockaddr **nam) 365 { 366 struct unpcb *unp, *unp2; 367 const struct sockaddr *sa; 368 369 /* 370 * Pass back name of connected socket, if it was bound and we are 371 * still connected (our peer may have closed already!). 372 */ 373 unp = sotounpcb(so); 374 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 375 376 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 377 UNP_LINK_RLOCK(); 378 unp2 = unp->unp_conn; 379 if (unp2 != NULL && unp2->unp_addr != NULL) { 380 UNP_PCB_LOCK(unp2); 381 sa = (struct sockaddr *) unp2->unp_addr; 382 bcopy(sa, *nam, sa->sa_len); 383 UNP_PCB_UNLOCK(unp2); 384 } else { 385 sa = &sun_noname; 386 bcopy(sa, *nam, sa->sa_len); 387 } 388 UNP_LINK_RUNLOCK(); 389 return (0); 390 } 391 392 static int 393 uipc_attach(struct socket *so, int proto, struct thread *td) 394 { 395 u_long sendspace, recvspace; 396 struct unpcb *unp; 397 int error; 398 399 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 400 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 401 switch (so->so_type) { 402 case SOCK_STREAM: 403 sendspace = unpst_sendspace; 404 recvspace = unpst_recvspace; 405 break; 406 407 case SOCK_DGRAM: 408 sendspace = unpdg_sendspace; 409 recvspace = unpdg_recvspace; 410 break; 411 412 case SOCK_SEQPACKET: 413 sendspace = unpsp_sendspace; 414 recvspace = unpsp_recvspace; 415 break; 416 417 default: 418 panic("uipc_attach"); 419 } 420 error = soreserve(so, sendspace, recvspace); 421 if (error) 422 return (error); 423 } 424 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 425 if (unp == NULL) 426 return (ENOBUFS); 427 LIST_INIT(&unp->unp_refs); 428 UNP_PCB_LOCK_INIT(unp); 429 unp->unp_socket = so; 430 so->so_pcb = unp; 431 unp->unp_refcount = 1; 432 433 UNP_LIST_LOCK(); 434 unp->unp_gencnt = ++unp_gencnt; 435 unp_count++; 436 switch (so->so_type) { 437 case SOCK_STREAM: 438 LIST_INSERT_HEAD(&unp_shead, unp, unp_link); 439 break; 440 441 case SOCK_DGRAM: 442 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link); 443 break; 444 445 case SOCK_SEQPACKET: 446 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link); 447 break; 448 449 default: 450 panic("uipc_attach"); 451 } 452 UNP_LIST_UNLOCK(); 453 454 return (0); 455 } 456 457 static int 458 uipc_bindat(int fd, struct socket *so, struct sockaddr *nam, struct thread *td) 459 { 460 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 461 struct vattr vattr; 462 int error, namelen; 463 struct nameidata nd; 464 struct unpcb *unp; 465 struct vnode *vp; 466 struct mount *mp; 467 cap_rights_t rights; 468 char *buf; 469 470 if (nam->sa_family != AF_UNIX) 471 return (EAFNOSUPPORT); 472 473 unp = sotounpcb(so); 474 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 475 476 if (soun->sun_len > sizeof(struct sockaddr_un)) 477 return (EINVAL); 478 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 479 if (namelen <= 0) 480 return (EINVAL); 481 482 /* 483 * We don't allow simultaneous bind() calls on a single UNIX domain 484 * socket, so flag in-progress operations, and return an error if an 485 * operation is already in progress. 486 * 487 * Historically, we have not allowed a socket to be rebound, so this 488 * also returns an error. Not allowing re-binding simplifies the 489 * implementation and avoids a great many possible failure modes. 490 */ 491 UNP_PCB_LOCK(unp); 492 if (unp->unp_vnode != NULL) { 493 UNP_PCB_UNLOCK(unp); 494 return (EINVAL); 495 } 496 if (unp->unp_flags & UNP_BINDING) { 497 UNP_PCB_UNLOCK(unp); 498 return (EALREADY); 499 } 500 unp->unp_flags |= UNP_BINDING; 501 UNP_PCB_UNLOCK(unp); 502 503 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 504 bcopy(soun->sun_path, buf, namelen); 505 buf[namelen] = 0; 506 507 restart: 508 NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME | NOCACHE, 509 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td); 510 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 511 error = namei(&nd); 512 if (error) 513 goto error; 514 vp = nd.ni_vp; 515 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 516 NDFREE(&nd, NDF_ONLY_PNBUF); 517 if (nd.ni_dvp == vp) 518 vrele(nd.ni_dvp); 519 else 520 vput(nd.ni_dvp); 521 if (vp != NULL) { 522 vrele(vp); 523 error = EADDRINUSE; 524 goto error; 525 } 526 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 527 if (error) 528 goto error; 529 goto restart; 530 } 531 VATTR_NULL(&vattr); 532 vattr.va_type = VSOCK; 533 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 534 #ifdef MAC 535 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 536 &vattr); 537 #endif 538 if (error == 0) 539 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 540 NDFREE(&nd, NDF_ONLY_PNBUF); 541 vput(nd.ni_dvp); 542 if (error) { 543 vn_finished_write(mp); 544 goto error; 545 } 546 vp = nd.ni_vp; 547 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 548 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 549 550 UNP_LINK_WLOCK(); 551 UNP_PCB_LOCK(unp); 552 VOP_UNP_BIND(vp, unp->unp_socket); 553 unp->unp_vnode = vp; 554 unp->unp_addr = soun; 555 unp->unp_flags &= ~UNP_BINDING; 556 UNP_PCB_UNLOCK(unp); 557 UNP_LINK_WUNLOCK(); 558 VOP_UNLOCK(vp, 0); 559 vn_finished_write(mp); 560 free(buf, M_TEMP); 561 return (0); 562 563 error: 564 UNP_PCB_LOCK(unp); 565 unp->unp_flags &= ~UNP_BINDING; 566 UNP_PCB_UNLOCK(unp); 567 free(buf, M_TEMP); 568 return (error); 569 } 570 571 static int 572 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 573 { 574 575 return (uipc_bindat(AT_FDCWD, so, nam, td)); 576 } 577 578 static int 579 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 580 { 581 int error; 582 583 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 584 UNP_LINK_WLOCK(); 585 error = unp_connect(so, nam, td); 586 UNP_LINK_WUNLOCK(); 587 return (error); 588 } 589 590 static int 591 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 592 struct thread *td) 593 { 594 int error; 595 596 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 597 UNP_LINK_WLOCK(); 598 error = unp_connectat(fd, so, nam, td); 599 UNP_LINK_WUNLOCK(); 600 return (error); 601 } 602 603 static void 604 uipc_close(struct socket *so) 605 { 606 struct unpcb *unp, *unp2; 607 608 unp = sotounpcb(so); 609 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 610 611 UNP_LINK_WLOCK(); 612 UNP_PCB_LOCK(unp); 613 unp2 = unp->unp_conn; 614 if (unp2 != NULL) { 615 UNP_PCB_LOCK(unp2); 616 unp_disconnect(unp, unp2); 617 UNP_PCB_UNLOCK(unp2); 618 } 619 UNP_PCB_UNLOCK(unp); 620 UNP_LINK_WUNLOCK(); 621 } 622 623 static int 624 uipc_connect2(struct socket *so1, struct socket *so2) 625 { 626 struct unpcb *unp, *unp2; 627 int error; 628 629 UNP_LINK_WLOCK(); 630 unp = so1->so_pcb; 631 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 632 UNP_PCB_LOCK(unp); 633 unp2 = so2->so_pcb; 634 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 635 UNP_PCB_LOCK(unp2); 636 error = unp_connect2(so1, so2, PRU_CONNECT2); 637 UNP_PCB_UNLOCK(unp2); 638 UNP_PCB_UNLOCK(unp); 639 UNP_LINK_WUNLOCK(); 640 return (error); 641 } 642 643 static void 644 uipc_detach(struct socket *so) 645 { 646 struct unpcb *unp, *unp2; 647 struct sockaddr_un *saved_unp_addr; 648 struct vnode *vp; 649 int freeunp, local_unp_rights; 650 651 unp = sotounpcb(so); 652 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 653 654 UNP_LINK_WLOCK(); 655 UNP_LIST_LOCK(); 656 UNP_PCB_LOCK(unp); 657 LIST_REMOVE(unp, unp_link); 658 unp->unp_gencnt = ++unp_gencnt; 659 --unp_count; 660 UNP_LIST_UNLOCK(); 661 662 /* 663 * XXXRW: Should assert vp->v_socket == so. 664 */ 665 if ((vp = unp->unp_vnode) != NULL) { 666 VOP_UNP_DETACH(vp); 667 unp->unp_vnode = NULL; 668 } 669 unp2 = unp->unp_conn; 670 if (unp2 != NULL) { 671 UNP_PCB_LOCK(unp2); 672 unp_disconnect(unp, unp2); 673 UNP_PCB_UNLOCK(unp2); 674 } 675 676 /* 677 * We hold the linkage lock exclusively, so it's OK to acquire 678 * multiple pcb locks at a time. 679 */ 680 while (!LIST_EMPTY(&unp->unp_refs)) { 681 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 682 683 UNP_PCB_LOCK(ref); 684 unp_drop(ref, ECONNRESET); 685 UNP_PCB_UNLOCK(ref); 686 } 687 local_unp_rights = unp_rights; 688 UNP_LINK_WUNLOCK(); 689 unp->unp_socket->so_pcb = NULL; 690 saved_unp_addr = unp->unp_addr; 691 unp->unp_addr = NULL; 692 unp->unp_refcount--; 693 freeunp = (unp->unp_refcount == 0); 694 if (saved_unp_addr != NULL) 695 free(saved_unp_addr, M_SONAME); 696 if (freeunp) { 697 UNP_PCB_LOCK_DESTROY(unp); 698 uma_zfree(unp_zone, unp); 699 } else 700 UNP_PCB_UNLOCK(unp); 701 if (vp) 702 vrele(vp); 703 if (local_unp_rights) 704 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 705 } 706 707 static int 708 uipc_disconnect(struct socket *so) 709 { 710 struct unpcb *unp, *unp2; 711 712 unp = sotounpcb(so); 713 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 714 715 UNP_LINK_WLOCK(); 716 UNP_PCB_LOCK(unp); 717 unp2 = unp->unp_conn; 718 if (unp2 != NULL) { 719 UNP_PCB_LOCK(unp2); 720 unp_disconnect(unp, unp2); 721 UNP_PCB_UNLOCK(unp2); 722 } 723 UNP_PCB_UNLOCK(unp); 724 UNP_LINK_WUNLOCK(); 725 return (0); 726 } 727 728 static int 729 uipc_listen(struct socket *so, int backlog, struct thread *td) 730 { 731 struct unpcb *unp; 732 int error; 733 734 unp = sotounpcb(so); 735 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 736 737 UNP_PCB_LOCK(unp); 738 if (unp->unp_vnode == NULL) { 739 UNP_PCB_UNLOCK(unp); 740 return (EINVAL); 741 } 742 743 SOCK_LOCK(so); 744 error = solisten_proto_check(so); 745 if (error == 0) { 746 cru2x(td->td_ucred, &unp->unp_peercred); 747 unp->unp_flags |= UNP_HAVEPCCACHED; 748 solisten_proto(so, backlog); 749 } 750 SOCK_UNLOCK(so); 751 UNP_PCB_UNLOCK(unp); 752 return (error); 753 } 754 755 static int 756 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 757 { 758 struct unpcb *unp, *unp2; 759 const struct sockaddr *sa; 760 761 unp = sotounpcb(so); 762 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 763 764 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 765 UNP_LINK_RLOCK(); 766 /* 767 * XXX: It seems that this test always fails even when connection is 768 * established. So, this else clause is added as workaround to 769 * return PF_LOCAL sockaddr. 770 */ 771 unp2 = unp->unp_conn; 772 if (unp2 != NULL) { 773 UNP_PCB_LOCK(unp2); 774 if (unp2->unp_addr != NULL) 775 sa = (struct sockaddr *) unp2->unp_addr; 776 else 777 sa = &sun_noname; 778 bcopy(sa, *nam, sa->sa_len); 779 UNP_PCB_UNLOCK(unp2); 780 } else { 781 sa = &sun_noname; 782 bcopy(sa, *nam, sa->sa_len); 783 } 784 UNP_LINK_RUNLOCK(); 785 return (0); 786 } 787 788 static int 789 uipc_rcvd(struct socket *so, int flags) 790 { 791 struct unpcb *unp, *unp2; 792 struct socket *so2; 793 u_int mbcnt, sbcc; 794 795 unp = sotounpcb(so); 796 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 797 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET, 798 ("%s: socktype %d", __func__, so->so_type)); 799 800 /* 801 * Adjust backpressure on sender and wakeup any waiting to write. 802 * 803 * The unp lock is acquired to maintain the validity of the unp_conn 804 * pointer; no lock on unp2 is required as unp2->unp_socket will be 805 * static as long as we don't permit unp2 to disconnect from unp, 806 * which is prevented by the lock on unp. We cache values from 807 * so_rcv to avoid holding the so_rcv lock over the entire 808 * transaction on the remote so_snd. 809 */ 810 SOCKBUF_LOCK(&so->so_rcv); 811 mbcnt = so->so_rcv.sb_mbcnt; 812 sbcc = sbavail(&so->so_rcv); 813 SOCKBUF_UNLOCK(&so->so_rcv); 814 /* 815 * There is a benign race condition at this point. If we're planning to 816 * clear SB_STOP, but uipc_send is called on the connected socket at 817 * this instant, it might add data to the sockbuf and set SB_STOP. Then 818 * we would erroneously clear SB_STOP below, even though the sockbuf is 819 * full. The race is benign because the only ill effect is to allow the 820 * sockbuf to exceed its size limit, and the size limits are not 821 * strictly guaranteed anyway. 822 */ 823 UNP_PCB_LOCK(unp); 824 unp2 = unp->unp_conn; 825 if (unp2 == NULL) { 826 UNP_PCB_UNLOCK(unp); 827 return (0); 828 } 829 so2 = unp2->unp_socket; 830 SOCKBUF_LOCK(&so2->so_snd); 831 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 832 so2->so_snd.sb_flags &= ~SB_STOP; 833 sowwakeup_locked(so2); 834 UNP_PCB_UNLOCK(unp); 835 return (0); 836 } 837 838 static int 839 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 840 struct mbuf *control, struct thread *td) 841 { 842 struct unpcb *unp, *unp2; 843 struct socket *so2; 844 u_int mbcnt, sbcc; 845 int error = 0; 846 847 unp = sotounpcb(so); 848 KASSERT(unp != NULL, ("%s: unp == NULL", __func__)); 849 KASSERT(so->so_type == SOCK_STREAM || so->so_type == SOCK_DGRAM || 850 so->so_type == SOCK_SEQPACKET, 851 ("%s: socktype %d", __func__, so->so_type)); 852 853 if (flags & PRUS_OOB) { 854 error = EOPNOTSUPP; 855 goto release; 856 } 857 if (control != NULL && (error = unp_internalize(&control, td))) 858 goto release; 859 if ((nam != NULL) || (flags & PRUS_EOF)) 860 UNP_LINK_WLOCK(); 861 else 862 UNP_LINK_RLOCK(); 863 switch (so->so_type) { 864 case SOCK_DGRAM: 865 { 866 const struct sockaddr *from; 867 868 unp2 = unp->unp_conn; 869 if (nam != NULL) { 870 UNP_LINK_WLOCK_ASSERT(); 871 if (unp2 != NULL) { 872 error = EISCONN; 873 break; 874 } 875 error = unp_connect(so, nam, td); 876 if (error) 877 break; 878 unp2 = unp->unp_conn; 879 } 880 881 /* 882 * Because connect() and send() are non-atomic in a sendto() 883 * with a target address, it's possible that the socket will 884 * have disconnected before the send() can run. In that case 885 * return the slightly counter-intuitive but otherwise 886 * correct error that the socket is not connected. 887 */ 888 if (unp2 == NULL) { 889 error = ENOTCONN; 890 break; 891 } 892 /* Lockless read. */ 893 if (unp2->unp_flags & UNP_WANTCRED) 894 control = unp_addsockcred(td, control); 895 UNP_PCB_LOCK(unp); 896 if (unp->unp_addr != NULL) 897 from = (struct sockaddr *)unp->unp_addr; 898 else 899 from = &sun_noname; 900 so2 = unp2->unp_socket; 901 SOCKBUF_LOCK(&so2->so_rcv); 902 if (sbappendaddr_locked(&so2->so_rcv, from, m, 903 control)) { 904 sorwakeup_locked(so2); 905 m = NULL; 906 control = NULL; 907 } else { 908 SOCKBUF_UNLOCK(&so2->so_rcv); 909 error = ENOBUFS; 910 } 911 if (nam != NULL) { 912 UNP_LINK_WLOCK_ASSERT(); 913 UNP_PCB_LOCK(unp2); 914 unp_disconnect(unp, unp2); 915 UNP_PCB_UNLOCK(unp2); 916 } 917 UNP_PCB_UNLOCK(unp); 918 break; 919 } 920 921 case SOCK_SEQPACKET: 922 case SOCK_STREAM: 923 if ((so->so_state & SS_ISCONNECTED) == 0) { 924 if (nam != NULL) { 925 UNP_LINK_WLOCK_ASSERT(); 926 error = unp_connect(so, nam, td); 927 if (error) 928 break; /* XXX */ 929 } else { 930 error = ENOTCONN; 931 break; 932 } 933 } 934 935 /* Lockless read. */ 936 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 937 error = EPIPE; 938 break; 939 } 940 941 /* 942 * Because connect() and send() are non-atomic in a sendto() 943 * with a target address, it's possible that the socket will 944 * have disconnected before the send() can run. In that case 945 * return the slightly counter-intuitive but otherwise 946 * correct error that the socket is not connected. 947 * 948 * Locking here must be done carefully: the linkage lock 949 * prevents interconnections between unpcbs from changing, so 950 * we can traverse from unp to unp2 without acquiring unp's 951 * lock. Socket buffer locks follow unpcb locks, so we can 952 * acquire both remote and lock socket buffer locks. 953 */ 954 unp2 = unp->unp_conn; 955 if (unp2 == NULL) { 956 error = ENOTCONN; 957 break; 958 } 959 so2 = unp2->unp_socket; 960 UNP_PCB_LOCK(unp2); 961 SOCKBUF_LOCK(&so2->so_rcv); 962 if (unp2->unp_flags & UNP_WANTCRED) { 963 /* 964 * Credentials are passed only once on SOCK_STREAM 965 * and SOCK_SEQPACKET. 966 */ 967 unp2->unp_flags &= ~UNP_WANTCRED; 968 control = unp_addsockcred(td, control); 969 } 970 /* 971 * Send to paired receive port, and then reduce send buffer 972 * hiwater marks to maintain backpressure. Wake up readers. 973 */ 974 switch (so->so_type) { 975 case SOCK_STREAM: 976 if (control != NULL) { 977 if (sbappendcontrol_locked(&so2->so_rcv, m, 978 control)) 979 control = NULL; 980 } else 981 sbappend_locked(&so2->so_rcv, m); 982 break; 983 984 case SOCK_SEQPACKET: { 985 const struct sockaddr *from; 986 987 from = &sun_noname; 988 /* 989 * Don't check for space available in so2->so_rcv. 990 * Unix domain sockets only check for space in the 991 * sending sockbuf, and that check is performed one 992 * level up the stack. 993 */ 994 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 995 from, m, control)) 996 control = NULL; 997 break; 998 } 999 } 1000 1001 mbcnt = so2->so_rcv.sb_mbcnt; 1002 sbcc = sbavail(&so2->so_rcv); 1003 if (sbcc) 1004 sorwakeup_locked(so2); 1005 else 1006 SOCKBUF_UNLOCK(&so2->so_rcv); 1007 1008 /* 1009 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1010 * it would be possible for uipc_rcvd to be called at this 1011 * point, drain the receiving sockbuf, clear SB_STOP, and then 1012 * we would set SB_STOP below. That could lead to an empty 1013 * sockbuf having SB_STOP set 1014 */ 1015 SOCKBUF_LOCK(&so->so_snd); 1016 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1017 so->so_snd.sb_flags |= SB_STOP; 1018 SOCKBUF_UNLOCK(&so->so_snd); 1019 UNP_PCB_UNLOCK(unp2); 1020 m = NULL; 1021 break; 1022 } 1023 1024 /* 1025 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1026 */ 1027 if (flags & PRUS_EOF) { 1028 UNP_PCB_LOCK(unp); 1029 socantsendmore(so); 1030 unp_shutdown(unp); 1031 UNP_PCB_UNLOCK(unp); 1032 } 1033 1034 if ((nam != NULL) || (flags & PRUS_EOF)) 1035 UNP_LINK_WUNLOCK(); 1036 else 1037 UNP_LINK_RUNLOCK(); 1038 1039 if (control != NULL && error != 0) 1040 unp_dispose(control); 1041 1042 release: 1043 if (control != NULL) 1044 m_freem(control); 1045 if (m != NULL) 1046 m_freem(m); 1047 return (error); 1048 } 1049 1050 static int 1051 uipc_ready(struct socket *so, struct mbuf *m, int count) 1052 { 1053 struct unpcb *unp, *unp2; 1054 struct socket *so2; 1055 int error; 1056 1057 unp = sotounpcb(so); 1058 1059 UNP_LINK_RLOCK(); 1060 unp2 = unp->unp_conn; 1061 UNP_PCB_LOCK(unp2); 1062 so2 = unp2->unp_socket; 1063 1064 SOCKBUF_LOCK(&so2->so_rcv); 1065 if ((error = sbready(&so2->so_rcv, m, count)) == 0) 1066 sorwakeup_locked(so2); 1067 else 1068 SOCKBUF_UNLOCK(&so2->so_rcv); 1069 1070 UNP_PCB_UNLOCK(unp2); 1071 UNP_LINK_RUNLOCK(); 1072 1073 return (error); 1074 } 1075 1076 static int 1077 uipc_sense(struct socket *so, struct stat *sb) 1078 { 1079 struct unpcb *unp; 1080 1081 unp = sotounpcb(so); 1082 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1083 1084 sb->st_blksize = so->so_snd.sb_hiwat; 1085 UNP_PCB_LOCK(unp); 1086 sb->st_dev = NODEV; 1087 if (unp->unp_ino == 0) 1088 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 1089 sb->st_ino = unp->unp_ino; 1090 UNP_PCB_UNLOCK(unp); 1091 return (0); 1092 } 1093 1094 static int 1095 uipc_shutdown(struct socket *so) 1096 { 1097 struct unpcb *unp; 1098 1099 unp = sotounpcb(so); 1100 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1101 1102 UNP_LINK_WLOCK(); 1103 UNP_PCB_LOCK(unp); 1104 socantsendmore(so); 1105 unp_shutdown(unp); 1106 UNP_PCB_UNLOCK(unp); 1107 UNP_LINK_WUNLOCK(); 1108 return (0); 1109 } 1110 1111 static int 1112 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1113 { 1114 struct unpcb *unp; 1115 const struct sockaddr *sa; 1116 1117 unp = sotounpcb(so); 1118 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1119 1120 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1121 UNP_PCB_LOCK(unp); 1122 if (unp->unp_addr != NULL) 1123 sa = (struct sockaddr *) unp->unp_addr; 1124 else 1125 sa = &sun_noname; 1126 bcopy(sa, *nam, sa->sa_len); 1127 UNP_PCB_UNLOCK(unp); 1128 return (0); 1129 } 1130 1131 static struct pr_usrreqs uipc_usrreqs_dgram = { 1132 .pru_abort = uipc_abort, 1133 .pru_accept = uipc_accept, 1134 .pru_attach = uipc_attach, 1135 .pru_bind = uipc_bind, 1136 .pru_bindat = uipc_bindat, 1137 .pru_connect = uipc_connect, 1138 .pru_connectat = uipc_connectat, 1139 .pru_connect2 = uipc_connect2, 1140 .pru_detach = uipc_detach, 1141 .pru_disconnect = uipc_disconnect, 1142 .pru_listen = uipc_listen, 1143 .pru_peeraddr = uipc_peeraddr, 1144 .pru_rcvd = uipc_rcvd, 1145 .pru_send = uipc_send, 1146 .pru_sense = uipc_sense, 1147 .pru_shutdown = uipc_shutdown, 1148 .pru_sockaddr = uipc_sockaddr, 1149 .pru_soreceive = soreceive_dgram, 1150 .pru_close = uipc_close, 1151 }; 1152 1153 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1154 .pru_abort = uipc_abort, 1155 .pru_accept = uipc_accept, 1156 .pru_attach = uipc_attach, 1157 .pru_bind = uipc_bind, 1158 .pru_bindat = uipc_bindat, 1159 .pru_connect = uipc_connect, 1160 .pru_connectat = uipc_connectat, 1161 .pru_connect2 = uipc_connect2, 1162 .pru_detach = uipc_detach, 1163 .pru_disconnect = uipc_disconnect, 1164 .pru_listen = uipc_listen, 1165 .pru_peeraddr = uipc_peeraddr, 1166 .pru_rcvd = uipc_rcvd, 1167 .pru_send = uipc_send, 1168 .pru_sense = uipc_sense, 1169 .pru_shutdown = uipc_shutdown, 1170 .pru_sockaddr = uipc_sockaddr, 1171 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1172 .pru_close = uipc_close, 1173 }; 1174 1175 static struct pr_usrreqs uipc_usrreqs_stream = { 1176 .pru_abort = uipc_abort, 1177 .pru_accept = uipc_accept, 1178 .pru_attach = uipc_attach, 1179 .pru_bind = uipc_bind, 1180 .pru_bindat = uipc_bindat, 1181 .pru_connect = uipc_connect, 1182 .pru_connectat = uipc_connectat, 1183 .pru_connect2 = uipc_connect2, 1184 .pru_detach = uipc_detach, 1185 .pru_disconnect = uipc_disconnect, 1186 .pru_listen = uipc_listen, 1187 .pru_peeraddr = uipc_peeraddr, 1188 .pru_rcvd = uipc_rcvd, 1189 .pru_send = uipc_send, 1190 .pru_ready = uipc_ready, 1191 .pru_sense = uipc_sense, 1192 .pru_shutdown = uipc_shutdown, 1193 .pru_sockaddr = uipc_sockaddr, 1194 .pru_soreceive = soreceive_generic, 1195 .pru_close = uipc_close, 1196 }; 1197 1198 static int 1199 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1200 { 1201 struct unpcb *unp; 1202 struct xucred xu; 1203 int error, optval; 1204 1205 if (sopt->sopt_level != 0) 1206 return (EINVAL); 1207 1208 unp = sotounpcb(so); 1209 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1210 error = 0; 1211 switch (sopt->sopt_dir) { 1212 case SOPT_GET: 1213 switch (sopt->sopt_name) { 1214 case LOCAL_PEERCRED: 1215 UNP_PCB_LOCK(unp); 1216 if (unp->unp_flags & UNP_HAVEPC) 1217 xu = unp->unp_peercred; 1218 else { 1219 if (so->so_type == SOCK_STREAM) 1220 error = ENOTCONN; 1221 else 1222 error = EINVAL; 1223 } 1224 UNP_PCB_UNLOCK(unp); 1225 if (error == 0) 1226 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1227 break; 1228 1229 case LOCAL_CREDS: 1230 /* Unlocked read. */ 1231 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1232 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1233 break; 1234 1235 case LOCAL_CONNWAIT: 1236 /* Unlocked read. */ 1237 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1238 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1239 break; 1240 1241 default: 1242 error = EOPNOTSUPP; 1243 break; 1244 } 1245 break; 1246 1247 case SOPT_SET: 1248 switch (sopt->sopt_name) { 1249 case LOCAL_CREDS: 1250 case LOCAL_CONNWAIT: 1251 error = sooptcopyin(sopt, &optval, sizeof(optval), 1252 sizeof(optval)); 1253 if (error) 1254 break; 1255 1256 #define OPTSET(bit) do { \ 1257 UNP_PCB_LOCK(unp); \ 1258 if (optval) \ 1259 unp->unp_flags |= bit; \ 1260 else \ 1261 unp->unp_flags &= ~bit; \ 1262 UNP_PCB_UNLOCK(unp); \ 1263 } while (0) 1264 1265 switch (sopt->sopt_name) { 1266 case LOCAL_CREDS: 1267 OPTSET(UNP_WANTCRED); 1268 break; 1269 1270 case LOCAL_CONNWAIT: 1271 OPTSET(UNP_CONNWAIT); 1272 break; 1273 1274 default: 1275 break; 1276 } 1277 break; 1278 #undef OPTSET 1279 default: 1280 error = ENOPROTOOPT; 1281 break; 1282 } 1283 break; 1284 1285 default: 1286 error = EOPNOTSUPP; 1287 break; 1288 } 1289 return (error); 1290 } 1291 1292 static int 1293 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1294 { 1295 1296 return (unp_connectat(AT_FDCWD, so, nam, td)); 1297 } 1298 1299 static int 1300 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1301 struct thread *td) 1302 { 1303 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1304 struct vnode *vp; 1305 struct socket *so2, *so3; 1306 struct unpcb *unp, *unp2, *unp3; 1307 struct nameidata nd; 1308 char buf[SOCK_MAXADDRLEN]; 1309 struct sockaddr *sa; 1310 cap_rights_t rights; 1311 int error, len; 1312 1313 if (nam->sa_family != AF_UNIX) 1314 return (EAFNOSUPPORT); 1315 1316 UNP_LINK_WLOCK_ASSERT(); 1317 1318 unp = sotounpcb(so); 1319 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1320 1321 if (nam->sa_len > sizeof(struct sockaddr_un)) 1322 return (EINVAL); 1323 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1324 if (len <= 0) 1325 return (EINVAL); 1326 bcopy(soun->sun_path, buf, len); 1327 buf[len] = 0; 1328 1329 UNP_PCB_LOCK(unp); 1330 if (unp->unp_flags & UNP_CONNECTING) { 1331 UNP_PCB_UNLOCK(unp); 1332 return (EALREADY); 1333 } 1334 UNP_LINK_WUNLOCK(); 1335 unp->unp_flags |= UNP_CONNECTING; 1336 UNP_PCB_UNLOCK(unp); 1337 1338 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1339 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1340 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td); 1341 error = namei(&nd); 1342 if (error) 1343 vp = NULL; 1344 else 1345 vp = nd.ni_vp; 1346 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1347 NDFREE(&nd, NDF_ONLY_PNBUF); 1348 if (error) 1349 goto bad; 1350 1351 if (vp->v_type != VSOCK) { 1352 error = ENOTSOCK; 1353 goto bad; 1354 } 1355 #ifdef MAC 1356 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1357 if (error) 1358 goto bad; 1359 #endif 1360 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1361 if (error) 1362 goto bad; 1363 1364 unp = sotounpcb(so); 1365 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1366 1367 /* 1368 * Lock linkage lock for two reasons: make sure v_socket is stable, 1369 * and to protect simultaneous locking of multiple pcbs. 1370 */ 1371 UNP_LINK_WLOCK(); 1372 VOP_UNP_CONNECT(vp, &so2); 1373 if (so2 == NULL) { 1374 error = ECONNREFUSED; 1375 goto bad2; 1376 } 1377 if (so->so_type != so2->so_type) { 1378 error = EPROTOTYPE; 1379 goto bad2; 1380 } 1381 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1382 if (so2->so_options & SO_ACCEPTCONN) { 1383 CURVNET_SET(so2->so_vnet); 1384 so3 = sonewconn(so2, 0); 1385 CURVNET_RESTORE(); 1386 } else 1387 so3 = NULL; 1388 if (so3 == NULL) { 1389 error = ECONNREFUSED; 1390 goto bad2; 1391 } 1392 unp = sotounpcb(so); 1393 unp2 = sotounpcb(so2); 1394 unp3 = sotounpcb(so3); 1395 UNP_PCB_LOCK(unp); 1396 UNP_PCB_LOCK(unp2); 1397 UNP_PCB_LOCK(unp3); 1398 if (unp2->unp_addr != NULL) { 1399 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1400 unp3->unp_addr = (struct sockaddr_un *) sa; 1401 sa = NULL; 1402 } 1403 1404 /* 1405 * The connector's (client's) credentials are copied from its 1406 * process structure at the time of connect() (which is now). 1407 */ 1408 cru2x(td->td_ucred, &unp3->unp_peercred); 1409 unp3->unp_flags |= UNP_HAVEPC; 1410 1411 /* 1412 * The receiver's (server's) credentials are copied from the 1413 * unp_peercred member of socket on which the former called 1414 * listen(); uipc_listen() cached that process's credentials 1415 * at that time so we can use them now. 1416 */ 1417 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1418 ("unp_connect: listener without cached peercred")); 1419 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1420 sizeof(unp->unp_peercred)); 1421 unp->unp_flags |= UNP_HAVEPC; 1422 if (unp2->unp_flags & UNP_WANTCRED) 1423 unp3->unp_flags |= UNP_WANTCRED; 1424 UNP_PCB_UNLOCK(unp3); 1425 UNP_PCB_UNLOCK(unp2); 1426 UNP_PCB_UNLOCK(unp); 1427 #ifdef MAC 1428 mac_socketpeer_set_from_socket(so, so3); 1429 mac_socketpeer_set_from_socket(so3, so); 1430 #endif 1431 1432 so2 = so3; 1433 } 1434 unp = sotounpcb(so); 1435 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1436 unp2 = sotounpcb(so2); 1437 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL")); 1438 UNP_PCB_LOCK(unp); 1439 UNP_PCB_LOCK(unp2); 1440 error = unp_connect2(so, so2, PRU_CONNECT); 1441 UNP_PCB_UNLOCK(unp2); 1442 UNP_PCB_UNLOCK(unp); 1443 bad2: 1444 UNP_LINK_WUNLOCK(); 1445 bad: 1446 if (vp != NULL) 1447 vput(vp); 1448 free(sa, M_SONAME); 1449 UNP_LINK_WLOCK(); 1450 UNP_PCB_LOCK(unp); 1451 unp->unp_flags &= ~UNP_CONNECTING; 1452 UNP_PCB_UNLOCK(unp); 1453 return (error); 1454 } 1455 1456 static int 1457 unp_connect2(struct socket *so, struct socket *so2, int req) 1458 { 1459 struct unpcb *unp; 1460 struct unpcb *unp2; 1461 1462 unp = sotounpcb(so); 1463 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1464 unp2 = sotounpcb(so2); 1465 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1466 1467 UNP_LINK_WLOCK_ASSERT(); 1468 UNP_PCB_LOCK_ASSERT(unp); 1469 UNP_PCB_LOCK_ASSERT(unp2); 1470 1471 if (so2->so_type != so->so_type) 1472 return (EPROTOTYPE); 1473 unp->unp_conn = unp2; 1474 1475 switch (so->so_type) { 1476 case SOCK_DGRAM: 1477 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1478 soisconnected(so); 1479 break; 1480 1481 case SOCK_STREAM: 1482 case SOCK_SEQPACKET: 1483 unp2->unp_conn = unp; 1484 if (req == PRU_CONNECT && 1485 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1486 soisconnecting(so); 1487 else 1488 soisconnected(so); 1489 soisconnected(so2); 1490 break; 1491 1492 default: 1493 panic("unp_connect2"); 1494 } 1495 return (0); 1496 } 1497 1498 static void 1499 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1500 { 1501 struct socket *so; 1502 1503 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1504 1505 UNP_LINK_WLOCK_ASSERT(); 1506 UNP_PCB_LOCK_ASSERT(unp); 1507 UNP_PCB_LOCK_ASSERT(unp2); 1508 1509 unp->unp_conn = NULL; 1510 switch (unp->unp_socket->so_type) { 1511 case SOCK_DGRAM: 1512 LIST_REMOVE(unp, unp_reflink); 1513 so = unp->unp_socket; 1514 SOCK_LOCK(so); 1515 so->so_state &= ~SS_ISCONNECTED; 1516 SOCK_UNLOCK(so); 1517 break; 1518 1519 case SOCK_STREAM: 1520 case SOCK_SEQPACKET: 1521 soisdisconnected(unp->unp_socket); 1522 unp2->unp_conn = NULL; 1523 soisdisconnected(unp2->unp_socket); 1524 break; 1525 } 1526 } 1527 1528 /* 1529 * unp_pcblist() walks the global list of struct unpcb's to generate a 1530 * pointer list, bumping the refcount on each unpcb. It then copies them out 1531 * sequentially, validating the generation number on each to see if it has 1532 * been detached. All of this is necessary because copyout() may sleep on 1533 * disk I/O. 1534 */ 1535 static int 1536 unp_pcblist(SYSCTL_HANDLER_ARGS) 1537 { 1538 int error, i, n; 1539 int freeunp; 1540 struct unpcb *unp, **unp_list; 1541 unp_gen_t gencnt; 1542 struct xunpgen *xug; 1543 struct unp_head *head; 1544 struct xunpcb *xu; 1545 1546 switch ((intptr_t)arg1) { 1547 case SOCK_STREAM: 1548 head = &unp_shead; 1549 break; 1550 1551 case SOCK_DGRAM: 1552 head = &unp_dhead; 1553 break; 1554 1555 case SOCK_SEQPACKET: 1556 head = &unp_sphead; 1557 break; 1558 1559 default: 1560 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1561 } 1562 1563 /* 1564 * The process of preparing the PCB list is too time-consuming and 1565 * resource-intensive to repeat twice on every request. 1566 */ 1567 if (req->oldptr == NULL) { 1568 n = unp_count; 1569 req->oldidx = 2 * (sizeof *xug) 1570 + (n + n/8) * sizeof(struct xunpcb); 1571 return (0); 1572 } 1573 1574 if (req->newptr != NULL) 1575 return (EPERM); 1576 1577 /* 1578 * OK, now we're committed to doing something. 1579 */ 1580 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1581 UNP_LIST_LOCK(); 1582 gencnt = unp_gencnt; 1583 n = unp_count; 1584 UNP_LIST_UNLOCK(); 1585 1586 xug->xug_len = sizeof *xug; 1587 xug->xug_count = n; 1588 xug->xug_gen = gencnt; 1589 xug->xug_sogen = so_gencnt; 1590 error = SYSCTL_OUT(req, xug, sizeof *xug); 1591 if (error) { 1592 free(xug, M_TEMP); 1593 return (error); 1594 } 1595 1596 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1597 1598 UNP_LIST_LOCK(); 1599 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1600 unp = LIST_NEXT(unp, unp_link)) { 1601 UNP_PCB_LOCK(unp); 1602 if (unp->unp_gencnt <= gencnt) { 1603 if (cr_cansee(req->td->td_ucred, 1604 unp->unp_socket->so_cred)) { 1605 UNP_PCB_UNLOCK(unp); 1606 continue; 1607 } 1608 unp_list[i++] = unp; 1609 unp->unp_refcount++; 1610 } 1611 UNP_PCB_UNLOCK(unp); 1612 } 1613 UNP_LIST_UNLOCK(); 1614 n = i; /* In case we lost some during malloc. */ 1615 1616 error = 0; 1617 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1618 for (i = 0; i < n; i++) { 1619 unp = unp_list[i]; 1620 UNP_PCB_LOCK(unp); 1621 unp->unp_refcount--; 1622 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) { 1623 xu->xu_len = sizeof *xu; 1624 xu->xu_unpp = unp; 1625 /* 1626 * XXX - need more locking here to protect against 1627 * connect/disconnect races for SMP. 1628 */ 1629 if (unp->unp_addr != NULL) 1630 bcopy(unp->unp_addr, &xu->xu_addr, 1631 unp->unp_addr->sun_len); 1632 if (unp->unp_conn != NULL && 1633 unp->unp_conn->unp_addr != NULL) 1634 bcopy(unp->unp_conn->unp_addr, 1635 &xu->xu_caddr, 1636 unp->unp_conn->unp_addr->sun_len); 1637 bcopy(unp, &xu->xu_unp, sizeof *unp); 1638 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1639 UNP_PCB_UNLOCK(unp); 1640 error = SYSCTL_OUT(req, xu, sizeof *xu); 1641 } else { 1642 freeunp = (unp->unp_refcount == 0); 1643 UNP_PCB_UNLOCK(unp); 1644 if (freeunp) { 1645 UNP_PCB_LOCK_DESTROY(unp); 1646 uma_zfree(unp_zone, unp); 1647 } 1648 } 1649 } 1650 free(xu, M_TEMP); 1651 if (!error) { 1652 /* 1653 * Give the user an updated idea of our state. If the 1654 * generation differs from what we told her before, she knows 1655 * that something happened while we were processing this 1656 * request, and it might be necessary to retry. 1657 */ 1658 xug->xug_gen = unp_gencnt; 1659 xug->xug_sogen = so_gencnt; 1660 xug->xug_count = unp_count; 1661 error = SYSCTL_OUT(req, xug, sizeof *xug); 1662 } 1663 free(unp_list, M_TEMP); 1664 free(xug, M_TEMP); 1665 return (error); 1666 } 1667 1668 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1669 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1670 "List of active local datagram sockets"); 1671 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1672 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1673 "List of active local stream sockets"); 1674 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1675 CTLTYPE_OPAQUE | CTLFLAG_RD, 1676 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1677 "List of active local seqpacket sockets"); 1678 1679 static void 1680 unp_shutdown(struct unpcb *unp) 1681 { 1682 struct unpcb *unp2; 1683 struct socket *so; 1684 1685 UNP_LINK_WLOCK_ASSERT(); 1686 UNP_PCB_LOCK_ASSERT(unp); 1687 1688 unp2 = unp->unp_conn; 1689 if ((unp->unp_socket->so_type == SOCK_STREAM || 1690 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1691 so = unp2->unp_socket; 1692 if (so != NULL) 1693 socantrcvmore(so); 1694 } 1695 } 1696 1697 static void 1698 unp_drop(struct unpcb *unp, int errno) 1699 { 1700 struct socket *so = unp->unp_socket; 1701 struct unpcb *unp2; 1702 1703 UNP_LINK_WLOCK_ASSERT(); 1704 UNP_PCB_LOCK_ASSERT(unp); 1705 1706 so->so_error = errno; 1707 unp2 = unp->unp_conn; 1708 if (unp2 == NULL) 1709 return; 1710 UNP_PCB_LOCK(unp2); 1711 unp_disconnect(unp, unp2); 1712 UNP_PCB_UNLOCK(unp2); 1713 } 1714 1715 static void 1716 unp_freerights(struct filedescent **fdep, int fdcount) 1717 { 1718 struct file *fp; 1719 int i; 1720 1721 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1722 1723 for (i = 0; i < fdcount; i++) { 1724 fp = fdep[i]->fde_file; 1725 filecaps_free(&fdep[i]->fde_caps); 1726 unp_discard(fp); 1727 } 1728 free(fdep[0], M_FILECAPS); 1729 } 1730 1731 static int 1732 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 1733 { 1734 struct thread *td = curthread; /* XXX */ 1735 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1736 int i; 1737 int *fdp; 1738 struct filedesc *fdesc = td->td_proc->p_fd; 1739 struct filedescent *fde, **fdep; 1740 void *data; 1741 socklen_t clen = control->m_len, datalen; 1742 int error, newfds; 1743 u_int newlen; 1744 1745 UNP_LINK_UNLOCK_ASSERT(); 1746 1747 error = 0; 1748 if (controlp != NULL) /* controlp == NULL => free control messages */ 1749 *controlp = NULL; 1750 while (cm != NULL) { 1751 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1752 error = EINVAL; 1753 break; 1754 } 1755 data = CMSG_DATA(cm); 1756 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1757 if (cm->cmsg_level == SOL_SOCKET 1758 && cm->cmsg_type == SCM_RIGHTS) { 1759 newfds = datalen / sizeof(*fdep); 1760 if (newfds == 0) 1761 goto next; 1762 fdep = data; 1763 1764 /* If we're not outputting the descriptors free them. */ 1765 if (error || controlp == NULL) { 1766 unp_freerights(fdep, newfds); 1767 goto next; 1768 } 1769 FILEDESC_XLOCK(fdesc); 1770 1771 /* 1772 * Now change each pointer to an fd in the global 1773 * table to an integer that is the index to the local 1774 * fd table entry that we set up to point to the 1775 * global one we are transferring. 1776 */ 1777 newlen = newfds * sizeof(int); 1778 *controlp = sbcreatecontrol(NULL, newlen, 1779 SCM_RIGHTS, SOL_SOCKET); 1780 if (*controlp == NULL) { 1781 FILEDESC_XUNLOCK(fdesc); 1782 error = E2BIG; 1783 unp_freerights(fdep, newfds); 1784 goto next; 1785 } 1786 1787 fdp = (int *) 1788 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1789 if (fdallocn(td, 0, fdp, newfds) != 0) { 1790 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1791 error = EMSGSIZE; 1792 unp_freerights(fdep, newfds); 1793 m_freem(*controlp); 1794 *controlp = NULL; 1795 goto next; 1796 } 1797 for (i = 0; i < newfds; i++, fdp++) { 1798 fde = &fdesc->fd_ofiles[*fdp]; 1799 fde->fde_file = fdep[i]->fde_file; 1800 filecaps_move(&fdep[i]->fde_caps, 1801 &fde->fde_caps); 1802 if ((flags & MSG_CMSG_CLOEXEC) != 0) 1803 fde->fde_flags |= UF_EXCLOSE; 1804 unp_externalize_fp(fde->fde_file); 1805 } 1806 FILEDESC_XUNLOCK(fdesc); 1807 free(fdep[0], M_FILECAPS); 1808 } else { 1809 /* We can just copy anything else across. */ 1810 if (error || controlp == NULL) 1811 goto next; 1812 *controlp = sbcreatecontrol(NULL, datalen, 1813 cm->cmsg_type, cm->cmsg_level); 1814 if (*controlp == NULL) { 1815 error = ENOBUFS; 1816 goto next; 1817 } 1818 bcopy(data, 1819 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1820 datalen); 1821 } 1822 controlp = &(*controlp)->m_next; 1823 1824 next: 1825 if (CMSG_SPACE(datalen) < clen) { 1826 clen -= CMSG_SPACE(datalen); 1827 cm = (struct cmsghdr *) 1828 ((caddr_t)cm + CMSG_SPACE(datalen)); 1829 } else { 1830 clen = 0; 1831 cm = NULL; 1832 } 1833 } 1834 1835 m_freem(control); 1836 return (error); 1837 } 1838 1839 static void 1840 unp_zone_change(void *tag) 1841 { 1842 1843 uma_zone_set_max(unp_zone, maxsockets); 1844 } 1845 1846 static void 1847 unp_init(void) 1848 { 1849 1850 #ifdef VIMAGE 1851 if (!IS_DEFAULT_VNET(curvnet)) 1852 return; 1853 #endif 1854 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1855 NULL, NULL, UMA_ALIGN_PTR, 0); 1856 if (unp_zone == NULL) 1857 panic("unp_init"); 1858 uma_zone_set_max(unp_zone, maxsockets); 1859 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 1860 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 1861 NULL, EVENTHANDLER_PRI_ANY); 1862 LIST_INIT(&unp_dhead); 1863 LIST_INIT(&unp_shead); 1864 LIST_INIT(&unp_sphead); 1865 SLIST_INIT(&unp_defers); 1866 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 1867 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 1868 UNP_LINK_LOCK_INIT(); 1869 UNP_LIST_LOCK_INIT(); 1870 UNP_DEFERRED_LOCK_INIT(); 1871 } 1872 1873 static int 1874 unp_internalize(struct mbuf **controlp, struct thread *td) 1875 { 1876 struct mbuf *control = *controlp; 1877 struct proc *p = td->td_proc; 1878 struct filedesc *fdesc = p->p_fd; 1879 struct bintime *bt; 1880 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1881 struct cmsgcred *cmcred; 1882 struct filedescent *fde, **fdep, *fdev; 1883 struct file *fp; 1884 struct timeval *tv; 1885 int i, *fdp; 1886 void *data; 1887 socklen_t clen = control->m_len, datalen; 1888 int error, oldfds; 1889 u_int newlen; 1890 1891 UNP_LINK_UNLOCK_ASSERT(); 1892 1893 error = 0; 1894 *controlp = NULL; 1895 while (cm != NULL) { 1896 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1897 || cm->cmsg_len > clen || cm->cmsg_len < sizeof(*cm)) { 1898 error = EINVAL; 1899 goto out; 1900 } 1901 data = CMSG_DATA(cm); 1902 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1903 1904 switch (cm->cmsg_type) { 1905 /* 1906 * Fill in credential information. 1907 */ 1908 case SCM_CREDS: 1909 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1910 SCM_CREDS, SOL_SOCKET); 1911 if (*controlp == NULL) { 1912 error = ENOBUFS; 1913 goto out; 1914 } 1915 cmcred = (struct cmsgcred *) 1916 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1917 cmcred->cmcred_pid = p->p_pid; 1918 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1919 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1920 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1921 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1922 CMGROUP_MAX); 1923 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1924 cmcred->cmcred_groups[i] = 1925 td->td_ucred->cr_groups[i]; 1926 break; 1927 1928 case SCM_RIGHTS: 1929 oldfds = datalen / sizeof (int); 1930 if (oldfds == 0) 1931 break; 1932 /* 1933 * Check that all the FDs passed in refer to legal 1934 * files. If not, reject the entire operation. 1935 */ 1936 fdp = data; 1937 FILEDESC_SLOCK(fdesc); 1938 for (i = 0; i < oldfds; i++, fdp++) { 1939 fp = fget_locked(fdesc, *fdp); 1940 if (fp == NULL) { 1941 FILEDESC_SUNLOCK(fdesc); 1942 error = EBADF; 1943 goto out; 1944 } 1945 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1946 FILEDESC_SUNLOCK(fdesc); 1947 error = EOPNOTSUPP; 1948 goto out; 1949 } 1950 1951 } 1952 1953 /* 1954 * Now replace the integer FDs with pointers to the 1955 * file structure and capability rights. 1956 */ 1957 newlen = oldfds * sizeof(fdep[0]); 1958 *controlp = sbcreatecontrol(NULL, newlen, 1959 SCM_RIGHTS, SOL_SOCKET); 1960 if (*controlp == NULL) { 1961 FILEDESC_SUNLOCK(fdesc); 1962 error = E2BIG; 1963 goto out; 1964 } 1965 fdp = data; 1966 fdep = (struct filedescent **) 1967 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1968 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 1969 M_WAITOK); 1970 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 1971 fde = &fdesc->fd_ofiles[*fdp]; 1972 fdep[i] = fdev; 1973 fdep[i]->fde_file = fde->fde_file; 1974 filecaps_copy(&fde->fde_caps, 1975 &fdep[i]->fde_caps); 1976 unp_internalize_fp(fdep[i]->fde_file); 1977 } 1978 FILEDESC_SUNLOCK(fdesc); 1979 break; 1980 1981 case SCM_TIMESTAMP: 1982 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1983 SCM_TIMESTAMP, SOL_SOCKET); 1984 if (*controlp == NULL) { 1985 error = ENOBUFS; 1986 goto out; 1987 } 1988 tv = (struct timeval *) 1989 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1990 microtime(tv); 1991 break; 1992 1993 case SCM_BINTIME: 1994 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 1995 SCM_BINTIME, SOL_SOCKET); 1996 if (*controlp == NULL) { 1997 error = ENOBUFS; 1998 goto out; 1999 } 2000 bt = (struct bintime *) 2001 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 2002 bintime(bt); 2003 break; 2004 2005 default: 2006 error = EINVAL; 2007 goto out; 2008 } 2009 2010 controlp = &(*controlp)->m_next; 2011 if (CMSG_SPACE(datalen) < clen) { 2012 clen -= CMSG_SPACE(datalen); 2013 cm = (struct cmsghdr *) 2014 ((caddr_t)cm + CMSG_SPACE(datalen)); 2015 } else { 2016 clen = 0; 2017 cm = NULL; 2018 } 2019 } 2020 2021 out: 2022 m_freem(control); 2023 return (error); 2024 } 2025 2026 static struct mbuf * 2027 unp_addsockcred(struct thread *td, struct mbuf *control) 2028 { 2029 struct mbuf *m, *n, *n_prev; 2030 struct sockcred *sc; 2031 const struct cmsghdr *cm; 2032 int ngroups; 2033 int i; 2034 2035 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2036 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 2037 if (m == NULL) 2038 return (control); 2039 2040 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 2041 sc->sc_uid = td->td_ucred->cr_ruid; 2042 sc->sc_euid = td->td_ucred->cr_uid; 2043 sc->sc_gid = td->td_ucred->cr_rgid; 2044 sc->sc_egid = td->td_ucred->cr_gid; 2045 sc->sc_ngroups = ngroups; 2046 for (i = 0; i < sc->sc_ngroups; i++) 2047 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2048 2049 /* 2050 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2051 * created SCM_CREDS control message (struct sockcred) has another 2052 * format. 2053 */ 2054 if (control != NULL) 2055 for (n = control, n_prev = NULL; n != NULL;) { 2056 cm = mtod(n, struct cmsghdr *); 2057 if (cm->cmsg_level == SOL_SOCKET && 2058 cm->cmsg_type == SCM_CREDS) { 2059 if (n_prev == NULL) 2060 control = n->m_next; 2061 else 2062 n_prev->m_next = n->m_next; 2063 n = m_free(n); 2064 } else { 2065 n_prev = n; 2066 n = n->m_next; 2067 } 2068 } 2069 2070 /* Prepend it to the head. */ 2071 m->m_next = control; 2072 return (m); 2073 } 2074 2075 static struct unpcb * 2076 fptounp(struct file *fp) 2077 { 2078 struct socket *so; 2079 2080 if (fp->f_type != DTYPE_SOCKET) 2081 return (NULL); 2082 if ((so = fp->f_data) == NULL) 2083 return (NULL); 2084 if (so->so_proto->pr_domain != &localdomain) 2085 return (NULL); 2086 return sotounpcb(so); 2087 } 2088 2089 static void 2090 unp_discard(struct file *fp) 2091 { 2092 struct unp_defer *dr; 2093 2094 if (unp_externalize_fp(fp)) { 2095 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2096 dr->ud_fp = fp; 2097 UNP_DEFERRED_LOCK(); 2098 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2099 UNP_DEFERRED_UNLOCK(); 2100 atomic_add_int(&unp_defers_count, 1); 2101 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2102 } else 2103 (void) closef(fp, (struct thread *)NULL); 2104 } 2105 2106 static void 2107 unp_process_defers(void *arg __unused, int pending) 2108 { 2109 struct unp_defer *dr; 2110 SLIST_HEAD(, unp_defer) drl; 2111 int count; 2112 2113 SLIST_INIT(&drl); 2114 for (;;) { 2115 UNP_DEFERRED_LOCK(); 2116 if (SLIST_FIRST(&unp_defers) == NULL) { 2117 UNP_DEFERRED_UNLOCK(); 2118 break; 2119 } 2120 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2121 UNP_DEFERRED_UNLOCK(); 2122 count = 0; 2123 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2124 SLIST_REMOVE_HEAD(&drl, ud_link); 2125 closef(dr->ud_fp, NULL); 2126 free(dr, M_TEMP); 2127 count++; 2128 } 2129 atomic_add_int(&unp_defers_count, -count); 2130 } 2131 } 2132 2133 static void 2134 unp_internalize_fp(struct file *fp) 2135 { 2136 struct unpcb *unp; 2137 2138 UNP_LINK_WLOCK(); 2139 if ((unp = fptounp(fp)) != NULL) { 2140 unp->unp_file = fp; 2141 unp->unp_msgcount++; 2142 } 2143 fhold(fp); 2144 unp_rights++; 2145 UNP_LINK_WUNLOCK(); 2146 } 2147 2148 static int 2149 unp_externalize_fp(struct file *fp) 2150 { 2151 struct unpcb *unp; 2152 int ret; 2153 2154 UNP_LINK_WLOCK(); 2155 if ((unp = fptounp(fp)) != NULL) { 2156 unp->unp_msgcount--; 2157 ret = 1; 2158 } else 2159 ret = 0; 2160 unp_rights--; 2161 UNP_LINK_WUNLOCK(); 2162 return (ret); 2163 } 2164 2165 /* 2166 * unp_defer indicates whether additional work has been defered for a future 2167 * pass through unp_gc(). It is thread local and does not require explicit 2168 * synchronization. 2169 */ 2170 static int unp_marked; 2171 static int unp_unreachable; 2172 2173 static void 2174 unp_accessable(struct filedescent **fdep, int fdcount) 2175 { 2176 struct unpcb *unp; 2177 struct file *fp; 2178 int i; 2179 2180 for (i = 0; i < fdcount; i++) { 2181 fp = fdep[i]->fde_file; 2182 if ((unp = fptounp(fp)) == NULL) 2183 continue; 2184 if (unp->unp_gcflag & UNPGC_REF) 2185 continue; 2186 unp->unp_gcflag &= ~UNPGC_DEAD; 2187 unp->unp_gcflag |= UNPGC_REF; 2188 unp_marked++; 2189 } 2190 } 2191 2192 static void 2193 unp_gc_process(struct unpcb *unp) 2194 { 2195 struct socket *soa; 2196 struct socket *so; 2197 struct file *fp; 2198 2199 /* Already processed. */ 2200 if (unp->unp_gcflag & UNPGC_SCANNED) 2201 return; 2202 fp = unp->unp_file; 2203 2204 /* 2205 * Check for a socket potentially in a cycle. It must be in a 2206 * queue as indicated by msgcount, and this must equal the file 2207 * reference count. Note that when msgcount is 0 the file is NULL. 2208 */ 2209 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2210 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2211 unp->unp_gcflag |= UNPGC_DEAD; 2212 unp_unreachable++; 2213 return; 2214 } 2215 2216 /* 2217 * Mark all sockets we reference with RIGHTS. 2218 */ 2219 so = unp->unp_socket; 2220 SOCKBUF_LOCK(&so->so_rcv); 2221 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2222 SOCKBUF_UNLOCK(&so->so_rcv); 2223 2224 /* 2225 * Mark all sockets in our accept queue. 2226 */ 2227 ACCEPT_LOCK(); 2228 TAILQ_FOREACH(soa, &so->so_comp, so_list) { 2229 SOCKBUF_LOCK(&soa->so_rcv); 2230 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2231 SOCKBUF_UNLOCK(&soa->so_rcv); 2232 } 2233 ACCEPT_UNLOCK(); 2234 unp->unp_gcflag |= UNPGC_SCANNED; 2235 } 2236 2237 static int unp_recycled; 2238 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2239 "Number of unreachable sockets claimed by the garbage collector."); 2240 2241 static int unp_taskcount; 2242 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2243 "Number of times the garbage collector has run."); 2244 2245 static void 2246 unp_gc(__unused void *arg, int pending) 2247 { 2248 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2249 NULL }; 2250 struct unp_head **head; 2251 struct file *f, **unref; 2252 struct unpcb *unp; 2253 int i, total; 2254 2255 unp_taskcount++; 2256 UNP_LIST_LOCK(); 2257 /* 2258 * First clear all gc flags from previous runs. 2259 */ 2260 for (head = heads; *head != NULL; head++) 2261 LIST_FOREACH(unp, *head, unp_link) 2262 unp->unp_gcflag = 0; 2263 2264 /* 2265 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2266 * is reachable all of the sockets it references are reachable. 2267 * Stop the scan once we do a complete loop without discovering 2268 * a new reachable socket. 2269 */ 2270 do { 2271 unp_unreachable = 0; 2272 unp_marked = 0; 2273 for (head = heads; *head != NULL; head++) 2274 LIST_FOREACH(unp, *head, unp_link) 2275 unp_gc_process(unp); 2276 } while (unp_marked); 2277 UNP_LIST_UNLOCK(); 2278 if (unp_unreachable == 0) 2279 return; 2280 2281 /* 2282 * Allocate space for a local list of dead unpcbs. 2283 */ 2284 unref = malloc(unp_unreachable * sizeof(struct file *), 2285 M_TEMP, M_WAITOK); 2286 2287 /* 2288 * Iterate looking for sockets which have been specifically marked 2289 * as as unreachable and store them locally. 2290 */ 2291 UNP_LINK_RLOCK(); 2292 UNP_LIST_LOCK(); 2293 for (total = 0, head = heads; *head != NULL; head++) 2294 LIST_FOREACH(unp, *head, unp_link) 2295 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2296 f = unp->unp_file; 2297 if (unp->unp_msgcount == 0 || f == NULL || 2298 f->f_count != unp->unp_msgcount) 2299 continue; 2300 unref[total++] = f; 2301 fhold(f); 2302 KASSERT(total <= unp_unreachable, 2303 ("unp_gc: incorrect unreachable count.")); 2304 } 2305 UNP_LIST_UNLOCK(); 2306 UNP_LINK_RUNLOCK(); 2307 2308 /* 2309 * Now flush all sockets, free'ing rights. This will free the 2310 * struct files associated with these sockets but leave each socket 2311 * with one remaining ref. 2312 */ 2313 for (i = 0; i < total; i++) { 2314 struct socket *so; 2315 2316 so = unref[i]->f_data; 2317 CURVNET_SET(so->so_vnet); 2318 sorflush(so); 2319 CURVNET_RESTORE(); 2320 } 2321 2322 /* 2323 * And finally release the sockets so they can be reclaimed. 2324 */ 2325 for (i = 0; i < total; i++) 2326 fdrop(unref[i], NULL); 2327 unp_recycled += total; 2328 free(unref, M_TEMP); 2329 } 2330 2331 static void 2332 unp_dispose(struct mbuf *m) 2333 { 2334 2335 if (m) 2336 unp_scan(m, unp_freerights); 2337 } 2338 2339 static void 2340 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2341 { 2342 struct mbuf *m; 2343 struct cmsghdr *cm; 2344 void *data; 2345 socklen_t clen, datalen; 2346 2347 while (m0 != NULL) { 2348 for (m = m0; m; m = m->m_next) { 2349 if (m->m_type != MT_CONTROL) 2350 continue; 2351 2352 cm = mtod(m, struct cmsghdr *); 2353 clen = m->m_len; 2354 2355 while (cm != NULL) { 2356 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2357 break; 2358 2359 data = CMSG_DATA(cm); 2360 datalen = (caddr_t)cm + cm->cmsg_len 2361 - (caddr_t)data; 2362 2363 if (cm->cmsg_level == SOL_SOCKET && 2364 cm->cmsg_type == SCM_RIGHTS) { 2365 (*op)(data, datalen / 2366 sizeof(struct filedescent *)); 2367 } 2368 2369 if (CMSG_SPACE(datalen) < clen) { 2370 clen -= CMSG_SPACE(datalen); 2371 cm = (struct cmsghdr *) 2372 ((caddr_t)cm + CMSG_SPACE(datalen)); 2373 } else { 2374 clen = 0; 2375 cm = NULL; 2376 } 2377 } 2378 } 2379 m0 = m0->m_nextpkt; 2380 } 2381 } 2382 2383 /* 2384 * A helper function called by VFS before socket-type vnode reclamation. 2385 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2386 * use count. 2387 */ 2388 void 2389 vfs_unp_reclaim(struct vnode *vp) 2390 { 2391 struct socket *so; 2392 struct unpcb *unp; 2393 int active; 2394 2395 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2396 KASSERT(vp->v_type == VSOCK, 2397 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2398 2399 active = 0; 2400 UNP_LINK_WLOCK(); 2401 VOP_UNP_CONNECT(vp, &so); 2402 if (so == NULL) 2403 goto done; 2404 unp = sotounpcb(so); 2405 if (unp == NULL) 2406 goto done; 2407 UNP_PCB_LOCK(unp); 2408 if (unp->unp_vnode == vp) { 2409 VOP_UNP_DETACH(vp); 2410 unp->unp_vnode = NULL; 2411 active = 1; 2412 } 2413 UNP_PCB_UNLOCK(unp); 2414 done: 2415 UNP_LINK_WUNLOCK(); 2416 if (active) 2417 vunref(vp); 2418 } 2419 2420 #ifdef DDB 2421 static void 2422 db_print_indent(int indent) 2423 { 2424 int i; 2425 2426 for (i = 0; i < indent; i++) 2427 db_printf(" "); 2428 } 2429 2430 static void 2431 db_print_unpflags(int unp_flags) 2432 { 2433 int comma; 2434 2435 comma = 0; 2436 if (unp_flags & UNP_HAVEPC) { 2437 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2438 comma = 1; 2439 } 2440 if (unp_flags & UNP_HAVEPCCACHED) { 2441 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : ""); 2442 comma = 1; 2443 } 2444 if (unp_flags & UNP_WANTCRED) { 2445 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2446 comma = 1; 2447 } 2448 if (unp_flags & UNP_CONNWAIT) { 2449 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2450 comma = 1; 2451 } 2452 if (unp_flags & UNP_CONNECTING) { 2453 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2454 comma = 1; 2455 } 2456 if (unp_flags & UNP_BINDING) { 2457 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2458 comma = 1; 2459 } 2460 } 2461 2462 static void 2463 db_print_xucred(int indent, struct xucred *xu) 2464 { 2465 int comma, i; 2466 2467 db_print_indent(indent); 2468 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2469 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2470 db_print_indent(indent); 2471 db_printf("cr_groups: "); 2472 comma = 0; 2473 for (i = 0; i < xu->cr_ngroups; i++) { 2474 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2475 comma = 1; 2476 } 2477 db_printf("\n"); 2478 } 2479 2480 static void 2481 db_print_unprefs(int indent, struct unp_head *uh) 2482 { 2483 struct unpcb *unp; 2484 int counter; 2485 2486 counter = 0; 2487 LIST_FOREACH(unp, uh, unp_reflink) { 2488 if (counter % 4 == 0) 2489 db_print_indent(indent); 2490 db_printf("%p ", unp); 2491 if (counter % 4 == 3) 2492 db_printf("\n"); 2493 counter++; 2494 } 2495 if (counter != 0 && counter % 4 != 0) 2496 db_printf("\n"); 2497 } 2498 2499 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2500 { 2501 struct unpcb *unp; 2502 2503 if (!have_addr) { 2504 db_printf("usage: show unpcb <addr>\n"); 2505 return; 2506 } 2507 unp = (struct unpcb *)addr; 2508 2509 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2510 unp->unp_vnode); 2511 2512 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2513 unp->unp_conn); 2514 2515 db_printf("unp_refs:\n"); 2516 db_print_unprefs(2, &unp->unp_refs); 2517 2518 /* XXXRW: Would be nice to print the full address, if any. */ 2519 db_printf("unp_addr: %p\n", unp->unp_addr); 2520 2521 db_printf("unp_gencnt: %llu\n", 2522 (unsigned long long)unp->unp_gencnt); 2523 2524 db_printf("unp_flags: %x (", unp->unp_flags); 2525 db_print_unpflags(unp->unp_flags); 2526 db_printf(")\n"); 2527 2528 db_printf("unp_peercred:\n"); 2529 db_print_xucred(2, &unp->unp_peercred); 2530 2531 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2532 } 2533 #endif 2534