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 unp = sotounpcb(so); 471 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 472 473 if (soun->sun_len > sizeof(struct sockaddr_un)) 474 return (EINVAL); 475 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 476 if (namelen <= 0) 477 return (EINVAL); 478 479 /* 480 * We don't allow simultaneous bind() calls on a single UNIX domain 481 * socket, so flag in-progress operations, and return an error if an 482 * operation is already in progress. 483 * 484 * Historically, we have not allowed a socket to be rebound, so this 485 * also returns an error. Not allowing re-binding simplifies the 486 * implementation and avoids a great many possible failure modes. 487 */ 488 UNP_PCB_LOCK(unp); 489 if (unp->unp_vnode != NULL) { 490 UNP_PCB_UNLOCK(unp); 491 return (EINVAL); 492 } 493 if (unp->unp_flags & UNP_BINDING) { 494 UNP_PCB_UNLOCK(unp); 495 return (EALREADY); 496 } 497 unp->unp_flags |= UNP_BINDING; 498 UNP_PCB_UNLOCK(unp); 499 500 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 501 bcopy(soun->sun_path, buf, namelen); 502 buf[namelen] = 0; 503 504 restart: 505 NDINIT_ATRIGHTS(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME, 506 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_BINDAT), td); 507 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 508 error = namei(&nd); 509 if (error) 510 goto error; 511 vp = nd.ni_vp; 512 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 513 NDFREE(&nd, NDF_ONLY_PNBUF); 514 if (nd.ni_dvp == vp) 515 vrele(nd.ni_dvp); 516 else 517 vput(nd.ni_dvp); 518 if (vp != NULL) { 519 vrele(vp); 520 error = EADDRINUSE; 521 goto error; 522 } 523 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 524 if (error) 525 goto error; 526 goto restart; 527 } 528 VATTR_NULL(&vattr); 529 vattr.va_type = VSOCK; 530 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 531 #ifdef MAC 532 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 533 &vattr); 534 #endif 535 if (error == 0) 536 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 537 NDFREE(&nd, NDF_ONLY_PNBUF); 538 vput(nd.ni_dvp); 539 if (error) { 540 vn_finished_write(mp); 541 goto error; 542 } 543 vp = nd.ni_vp; 544 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 545 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 546 547 UNP_LINK_WLOCK(); 548 UNP_PCB_LOCK(unp); 549 VOP_UNP_BIND(vp, unp->unp_socket); 550 unp->unp_vnode = vp; 551 unp->unp_addr = soun; 552 unp->unp_flags &= ~UNP_BINDING; 553 UNP_PCB_UNLOCK(unp); 554 UNP_LINK_WUNLOCK(); 555 VOP_UNLOCK(vp, 0); 556 vn_finished_write(mp); 557 free(buf, M_TEMP); 558 return (0); 559 560 error: 561 UNP_PCB_LOCK(unp); 562 unp->unp_flags &= ~UNP_BINDING; 563 UNP_PCB_UNLOCK(unp); 564 free(buf, M_TEMP); 565 return (error); 566 } 567 568 static int 569 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 570 { 571 572 return (uipc_bindat(AT_FDCWD, so, nam, td)); 573 } 574 575 static int 576 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 577 { 578 int error; 579 580 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 581 UNP_LINK_WLOCK(); 582 error = unp_connect(so, nam, td); 583 UNP_LINK_WUNLOCK(); 584 return (error); 585 } 586 587 static int 588 uipc_connectat(int fd, struct socket *so, struct sockaddr *nam, 589 struct thread *td) 590 { 591 int error; 592 593 KASSERT(td == curthread, ("uipc_connectat: td != curthread")); 594 UNP_LINK_WLOCK(); 595 error = unp_connectat(fd, so, nam, td); 596 UNP_LINK_WUNLOCK(); 597 return (error); 598 } 599 600 static void 601 uipc_close(struct socket *so) 602 { 603 struct unpcb *unp, *unp2; 604 605 unp = sotounpcb(so); 606 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 607 608 UNP_LINK_WLOCK(); 609 UNP_PCB_LOCK(unp); 610 unp2 = unp->unp_conn; 611 if (unp2 != NULL) { 612 UNP_PCB_LOCK(unp2); 613 unp_disconnect(unp, unp2); 614 UNP_PCB_UNLOCK(unp2); 615 } 616 UNP_PCB_UNLOCK(unp); 617 UNP_LINK_WUNLOCK(); 618 } 619 620 static int 621 uipc_connect2(struct socket *so1, struct socket *so2) 622 { 623 struct unpcb *unp, *unp2; 624 int error; 625 626 UNP_LINK_WLOCK(); 627 unp = so1->so_pcb; 628 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 629 UNP_PCB_LOCK(unp); 630 unp2 = so2->so_pcb; 631 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 632 UNP_PCB_LOCK(unp2); 633 error = unp_connect2(so1, so2, PRU_CONNECT2); 634 UNP_PCB_UNLOCK(unp2); 635 UNP_PCB_UNLOCK(unp); 636 UNP_LINK_WUNLOCK(); 637 return (error); 638 } 639 640 static void 641 uipc_detach(struct socket *so) 642 { 643 struct unpcb *unp, *unp2; 644 struct sockaddr_un *saved_unp_addr; 645 struct vnode *vp; 646 int freeunp, local_unp_rights; 647 648 unp = sotounpcb(so); 649 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 650 651 UNP_LINK_WLOCK(); 652 UNP_LIST_LOCK(); 653 UNP_PCB_LOCK(unp); 654 LIST_REMOVE(unp, unp_link); 655 unp->unp_gencnt = ++unp_gencnt; 656 --unp_count; 657 UNP_LIST_UNLOCK(); 658 659 /* 660 * XXXRW: Should assert vp->v_socket == so. 661 */ 662 if ((vp = unp->unp_vnode) != NULL) { 663 VOP_UNP_DETACH(vp); 664 unp->unp_vnode = NULL; 665 } 666 unp2 = unp->unp_conn; 667 if (unp2 != NULL) { 668 UNP_PCB_LOCK(unp2); 669 unp_disconnect(unp, unp2); 670 UNP_PCB_UNLOCK(unp2); 671 } 672 673 /* 674 * We hold the linkage lock exclusively, so it's OK to acquire 675 * multiple pcb locks at a time. 676 */ 677 while (!LIST_EMPTY(&unp->unp_refs)) { 678 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 679 680 UNP_PCB_LOCK(ref); 681 unp_drop(ref, ECONNRESET); 682 UNP_PCB_UNLOCK(ref); 683 } 684 local_unp_rights = unp_rights; 685 UNP_LINK_WUNLOCK(); 686 unp->unp_socket->so_pcb = NULL; 687 saved_unp_addr = unp->unp_addr; 688 unp->unp_addr = NULL; 689 unp->unp_refcount--; 690 freeunp = (unp->unp_refcount == 0); 691 if (saved_unp_addr != NULL) 692 free(saved_unp_addr, M_SONAME); 693 if (freeunp) { 694 UNP_PCB_LOCK_DESTROY(unp); 695 uma_zfree(unp_zone, unp); 696 } else 697 UNP_PCB_UNLOCK(unp); 698 if (vp) 699 vrele(vp); 700 if (local_unp_rights) 701 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 702 } 703 704 static int 705 uipc_disconnect(struct socket *so) 706 { 707 struct unpcb *unp, *unp2; 708 709 unp = sotounpcb(so); 710 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 711 712 UNP_LINK_WLOCK(); 713 UNP_PCB_LOCK(unp); 714 unp2 = unp->unp_conn; 715 if (unp2 != NULL) { 716 UNP_PCB_LOCK(unp2); 717 unp_disconnect(unp, unp2); 718 UNP_PCB_UNLOCK(unp2); 719 } 720 UNP_PCB_UNLOCK(unp); 721 UNP_LINK_WUNLOCK(); 722 return (0); 723 } 724 725 static int 726 uipc_listen(struct socket *so, int backlog, struct thread *td) 727 { 728 struct unpcb *unp; 729 int error; 730 731 unp = sotounpcb(so); 732 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 733 734 UNP_PCB_LOCK(unp); 735 if (unp->unp_vnode == NULL) { 736 UNP_PCB_UNLOCK(unp); 737 return (EINVAL); 738 } 739 740 SOCK_LOCK(so); 741 error = solisten_proto_check(so); 742 if (error == 0) { 743 cru2x(td->td_ucred, &unp->unp_peercred); 744 unp->unp_flags |= UNP_HAVEPCCACHED; 745 solisten_proto(so, backlog); 746 } 747 SOCK_UNLOCK(so); 748 UNP_PCB_UNLOCK(unp); 749 return (error); 750 } 751 752 static int 753 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 754 { 755 struct unpcb *unp, *unp2; 756 const struct sockaddr *sa; 757 758 unp = sotounpcb(so); 759 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 760 761 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 762 UNP_LINK_RLOCK(); 763 /* 764 * XXX: It seems that this test always fails even when connection is 765 * established. So, this else clause is added as workaround to 766 * return PF_LOCAL sockaddr. 767 */ 768 unp2 = unp->unp_conn; 769 if (unp2 != NULL) { 770 UNP_PCB_LOCK(unp2); 771 if (unp2->unp_addr != NULL) 772 sa = (struct sockaddr *) unp2->unp_addr; 773 else 774 sa = &sun_noname; 775 bcopy(sa, *nam, sa->sa_len); 776 UNP_PCB_UNLOCK(unp2); 777 } else { 778 sa = &sun_noname; 779 bcopy(sa, *nam, sa->sa_len); 780 } 781 UNP_LINK_RUNLOCK(); 782 return (0); 783 } 784 785 static int 786 uipc_rcvd(struct socket *so, int flags) 787 { 788 struct unpcb *unp, *unp2; 789 struct socket *so2; 790 u_int mbcnt, sbcc; 791 792 unp = sotounpcb(so); 793 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL")); 794 795 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 796 panic("uipc_rcvd socktype %d", so->so_type); 797 798 /* 799 * Adjust backpressure on sender and wakeup any waiting to write. 800 * 801 * The unp lock is acquired to maintain the validity of the unp_conn 802 * pointer; no lock on unp2 is required as unp2->unp_socket will be 803 * static as long as we don't permit unp2 to disconnect from unp, 804 * which is prevented by the lock on unp. We cache values from 805 * so_rcv to avoid holding the so_rcv lock over the entire 806 * transaction on the remote so_snd. 807 */ 808 SOCKBUF_LOCK(&so->so_rcv); 809 mbcnt = so->so_rcv.sb_mbcnt; 810 sbcc = so->so_rcv.sb_cc; 811 SOCKBUF_UNLOCK(&so->so_rcv); 812 /* 813 * There is a benign race condition at this point. If we're planning to 814 * clear SB_STOP, but uipc_send is called on the connected socket at 815 * this instant, it might add data to the sockbuf and set SB_STOP. Then 816 * we would erroneously clear SB_STOP below, even though the sockbuf is 817 * full. The race is benign because the only ill effect is to allow the 818 * sockbuf to exceed its size limit, and the size limits are not 819 * strictly guaranteed anyway. 820 */ 821 UNP_PCB_LOCK(unp); 822 unp2 = unp->unp_conn; 823 if (unp2 == NULL) { 824 UNP_PCB_UNLOCK(unp); 825 return (0); 826 } 827 so2 = unp2->unp_socket; 828 SOCKBUF_LOCK(&so2->so_snd); 829 if (sbcc < so2->so_snd.sb_hiwat && mbcnt < so2->so_snd.sb_mbmax) 830 so2->so_snd.sb_flags &= ~SB_STOP; 831 sowwakeup_locked(so2); 832 UNP_PCB_UNLOCK(unp); 833 return (0); 834 } 835 836 static int 837 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 838 struct mbuf *control, struct thread *td) 839 { 840 struct unpcb *unp, *unp2; 841 struct socket *so2; 842 u_int mbcnt, sbcc; 843 int error = 0; 844 845 unp = sotounpcb(so); 846 KASSERT(unp != NULL, ("uipc_send: unp == NULL")); 847 848 if (flags & PRUS_OOB) { 849 error = EOPNOTSUPP; 850 goto release; 851 } 852 if (control != NULL && (error = unp_internalize(&control, td))) 853 goto release; 854 if ((nam != NULL) || (flags & PRUS_EOF)) 855 UNP_LINK_WLOCK(); 856 else 857 UNP_LINK_RLOCK(); 858 switch (so->so_type) { 859 case SOCK_DGRAM: 860 { 861 const struct sockaddr *from; 862 863 unp2 = unp->unp_conn; 864 if (nam != NULL) { 865 UNP_LINK_WLOCK_ASSERT(); 866 if (unp2 != NULL) { 867 error = EISCONN; 868 break; 869 } 870 error = unp_connect(so, nam, td); 871 if (error) 872 break; 873 unp2 = unp->unp_conn; 874 } 875 876 /* 877 * Because connect() and send() are non-atomic in a sendto() 878 * with a target address, it's possible that the socket will 879 * have disconnected before the send() can run. In that case 880 * return the slightly counter-intuitive but otherwise 881 * correct error that the socket is not connected. 882 */ 883 if (unp2 == NULL) { 884 error = ENOTCONN; 885 break; 886 } 887 /* Lockless read. */ 888 if (unp2->unp_flags & UNP_WANTCRED) 889 control = unp_addsockcred(td, control); 890 UNP_PCB_LOCK(unp); 891 if (unp->unp_addr != NULL) 892 from = (struct sockaddr *)unp->unp_addr; 893 else 894 from = &sun_noname; 895 so2 = unp2->unp_socket; 896 SOCKBUF_LOCK(&so2->so_rcv); 897 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, from, m, 898 control)) { 899 sorwakeup_locked(so2); 900 m = NULL; 901 control = NULL; 902 } else { 903 SOCKBUF_UNLOCK(&so2->so_rcv); 904 error = ENOBUFS; 905 } 906 if (nam != NULL) { 907 UNP_LINK_WLOCK_ASSERT(); 908 UNP_PCB_LOCK(unp2); 909 unp_disconnect(unp, unp2); 910 UNP_PCB_UNLOCK(unp2); 911 } 912 UNP_PCB_UNLOCK(unp); 913 break; 914 } 915 916 case SOCK_SEQPACKET: 917 case SOCK_STREAM: 918 if ((so->so_state & SS_ISCONNECTED) == 0) { 919 if (nam != NULL) { 920 UNP_LINK_WLOCK_ASSERT(); 921 error = unp_connect(so, nam, td); 922 if (error) 923 break; /* XXX */ 924 } else { 925 error = ENOTCONN; 926 break; 927 } 928 } 929 930 /* Lockless read. */ 931 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 932 error = EPIPE; 933 break; 934 } 935 936 /* 937 * Because connect() and send() are non-atomic in a sendto() 938 * with a target address, it's possible that the socket will 939 * have disconnected before the send() can run. In that case 940 * return the slightly counter-intuitive but otherwise 941 * correct error that the socket is not connected. 942 * 943 * Locking here must be done carefully: the linkage lock 944 * prevents interconnections between unpcbs from changing, so 945 * we can traverse from unp to unp2 without acquiring unp's 946 * lock. Socket buffer locks follow unpcb locks, so we can 947 * acquire both remote and lock socket buffer locks. 948 */ 949 unp2 = unp->unp_conn; 950 if (unp2 == NULL) { 951 error = ENOTCONN; 952 break; 953 } 954 so2 = unp2->unp_socket; 955 UNP_PCB_LOCK(unp2); 956 SOCKBUF_LOCK(&so2->so_rcv); 957 if (unp2->unp_flags & UNP_WANTCRED) { 958 /* 959 * Credentials are passed only once on SOCK_STREAM 960 * and SOCK_SEQPACKET. 961 */ 962 unp2->unp_flags &= ~UNP_WANTCRED; 963 control = unp_addsockcred(td, control); 964 } 965 /* 966 * Send to paired receive port, and then reduce send buffer 967 * hiwater marks to maintain backpressure. Wake up readers. 968 */ 969 switch (so->so_type) { 970 case SOCK_STREAM: 971 if (control != NULL) { 972 if (sbappendcontrol_locked(&so2->so_rcv, m, 973 control)) 974 control = NULL; 975 } else 976 sbappend_locked(&so2->so_rcv, m); 977 break; 978 979 case SOCK_SEQPACKET: { 980 const struct sockaddr *from; 981 982 from = &sun_noname; 983 /* 984 * Don't check for space available in so2->so_rcv. 985 * Unix domain sockets only check for space in the 986 * sending sockbuf, and that check is performed one 987 * level up the stack. 988 */ 989 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 990 from, m, control)) 991 control = NULL; 992 break; 993 } 994 } 995 996 mbcnt = so2->so_rcv.sb_mbcnt; 997 sbcc = so2->so_rcv.sb_cc; 998 sorwakeup_locked(so2); 999 1000 /* 1001 * The PCB lock on unp2 protects the SB_STOP flag. Without it, 1002 * it would be possible for uipc_rcvd to be called at this 1003 * point, drain the receiving sockbuf, clear SB_STOP, and then 1004 * we would set SB_STOP below. That could lead to an empty 1005 * sockbuf having SB_STOP set 1006 */ 1007 SOCKBUF_LOCK(&so->so_snd); 1008 if (sbcc >= so->so_snd.sb_hiwat || mbcnt >= so->so_snd.sb_mbmax) 1009 so->so_snd.sb_flags |= SB_STOP; 1010 SOCKBUF_UNLOCK(&so->so_snd); 1011 UNP_PCB_UNLOCK(unp2); 1012 m = NULL; 1013 break; 1014 1015 default: 1016 panic("uipc_send unknown socktype"); 1017 } 1018 1019 /* 1020 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1021 */ 1022 if (flags & PRUS_EOF) { 1023 UNP_PCB_LOCK(unp); 1024 socantsendmore(so); 1025 unp_shutdown(unp); 1026 UNP_PCB_UNLOCK(unp); 1027 } 1028 1029 if ((nam != NULL) || (flags & PRUS_EOF)) 1030 UNP_LINK_WUNLOCK(); 1031 else 1032 UNP_LINK_RUNLOCK(); 1033 1034 if (control != NULL && error != 0) 1035 unp_dispose(control); 1036 1037 release: 1038 if (control != NULL) 1039 m_freem(control); 1040 if (m != NULL) 1041 m_freem(m); 1042 return (error); 1043 } 1044 1045 static int 1046 uipc_sense(struct socket *so, struct stat *sb) 1047 { 1048 struct unpcb *unp; 1049 1050 unp = sotounpcb(so); 1051 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1052 1053 sb->st_blksize = so->so_snd.sb_hiwat; 1054 UNP_PCB_LOCK(unp); 1055 sb->st_dev = NODEV; 1056 if (unp->unp_ino == 0) 1057 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 1058 sb->st_ino = unp->unp_ino; 1059 UNP_PCB_UNLOCK(unp); 1060 return (0); 1061 } 1062 1063 static int 1064 uipc_shutdown(struct socket *so) 1065 { 1066 struct unpcb *unp; 1067 1068 unp = sotounpcb(so); 1069 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1070 1071 UNP_LINK_WLOCK(); 1072 UNP_PCB_LOCK(unp); 1073 socantsendmore(so); 1074 unp_shutdown(unp); 1075 UNP_PCB_UNLOCK(unp); 1076 UNP_LINK_WUNLOCK(); 1077 return (0); 1078 } 1079 1080 static int 1081 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1082 { 1083 struct unpcb *unp; 1084 const struct sockaddr *sa; 1085 1086 unp = sotounpcb(so); 1087 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1088 1089 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1090 UNP_PCB_LOCK(unp); 1091 if (unp->unp_addr != NULL) 1092 sa = (struct sockaddr *) unp->unp_addr; 1093 else 1094 sa = &sun_noname; 1095 bcopy(sa, *nam, sa->sa_len); 1096 UNP_PCB_UNLOCK(unp); 1097 return (0); 1098 } 1099 1100 static struct pr_usrreqs uipc_usrreqs_dgram = { 1101 .pru_abort = uipc_abort, 1102 .pru_accept = uipc_accept, 1103 .pru_attach = uipc_attach, 1104 .pru_bind = uipc_bind, 1105 .pru_bindat = uipc_bindat, 1106 .pru_connect = uipc_connect, 1107 .pru_connectat = uipc_connectat, 1108 .pru_connect2 = uipc_connect2, 1109 .pru_detach = uipc_detach, 1110 .pru_disconnect = uipc_disconnect, 1111 .pru_listen = uipc_listen, 1112 .pru_peeraddr = uipc_peeraddr, 1113 .pru_rcvd = uipc_rcvd, 1114 .pru_send = uipc_send, 1115 .pru_sense = uipc_sense, 1116 .pru_shutdown = uipc_shutdown, 1117 .pru_sockaddr = uipc_sockaddr, 1118 .pru_soreceive = soreceive_dgram, 1119 .pru_close = uipc_close, 1120 }; 1121 1122 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1123 .pru_abort = uipc_abort, 1124 .pru_accept = uipc_accept, 1125 .pru_attach = uipc_attach, 1126 .pru_bind = uipc_bind, 1127 .pru_bindat = uipc_bindat, 1128 .pru_connect = uipc_connect, 1129 .pru_connectat = uipc_connectat, 1130 .pru_connect2 = uipc_connect2, 1131 .pru_detach = uipc_detach, 1132 .pru_disconnect = uipc_disconnect, 1133 .pru_listen = uipc_listen, 1134 .pru_peeraddr = uipc_peeraddr, 1135 .pru_rcvd = uipc_rcvd, 1136 .pru_send = uipc_send, 1137 .pru_sense = uipc_sense, 1138 .pru_shutdown = uipc_shutdown, 1139 .pru_sockaddr = uipc_sockaddr, 1140 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1141 .pru_close = uipc_close, 1142 }; 1143 1144 static struct pr_usrreqs uipc_usrreqs_stream = { 1145 .pru_abort = uipc_abort, 1146 .pru_accept = uipc_accept, 1147 .pru_attach = uipc_attach, 1148 .pru_bind = uipc_bind, 1149 .pru_bindat = uipc_bindat, 1150 .pru_connect = uipc_connect, 1151 .pru_connectat = uipc_connectat, 1152 .pru_connect2 = uipc_connect2, 1153 .pru_detach = uipc_detach, 1154 .pru_disconnect = uipc_disconnect, 1155 .pru_listen = uipc_listen, 1156 .pru_peeraddr = uipc_peeraddr, 1157 .pru_rcvd = uipc_rcvd, 1158 .pru_send = uipc_send, 1159 .pru_sense = uipc_sense, 1160 .pru_shutdown = uipc_shutdown, 1161 .pru_sockaddr = uipc_sockaddr, 1162 .pru_soreceive = soreceive_generic, 1163 .pru_close = uipc_close, 1164 }; 1165 1166 static int 1167 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1168 { 1169 struct unpcb *unp; 1170 struct xucred xu; 1171 int error, optval; 1172 1173 if (sopt->sopt_level != 0) 1174 return (EINVAL); 1175 1176 unp = sotounpcb(so); 1177 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1178 error = 0; 1179 switch (sopt->sopt_dir) { 1180 case SOPT_GET: 1181 switch (sopt->sopt_name) { 1182 case LOCAL_PEERCRED: 1183 UNP_PCB_LOCK(unp); 1184 if (unp->unp_flags & UNP_HAVEPC) 1185 xu = unp->unp_peercred; 1186 else { 1187 if (so->so_type == SOCK_STREAM) 1188 error = ENOTCONN; 1189 else 1190 error = EINVAL; 1191 } 1192 UNP_PCB_UNLOCK(unp); 1193 if (error == 0) 1194 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1195 break; 1196 1197 case LOCAL_CREDS: 1198 /* Unlocked read. */ 1199 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1200 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1201 break; 1202 1203 case LOCAL_CONNWAIT: 1204 /* Unlocked read. */ 1205 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1206 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1207 break; 1208 1209 default: 1210 error = EOPNOTSUPP; 1211 break; 1212 } 1213 break; 1214 1215 case SOPT_SET: 1216 switch (sopt->sopt_name) { 1217 case LOCAL_CREDS: 1218 case LOCAL_CONNWAIT: 1219 error = sooptcopyin(sopt, &optval, sizeof(optval), 1220 sizeof(optval)); 1221 if (error) 1222 break; 1223 1224 #define OPTSET(bit) do { \ 1225 UNP_PCB_LOCK(unp); \ 1226 if (optval) \ 1227 unp->unp_flags |= bit; \ 1228 else \ 1229 unp->unp_flags &= ~bit; \ 1230 UNP_PCB_UNLOCK(unp); \ 1231 } while (0) 1232 1233 switch (sopt->sopt_name) { 1234 case LOCAL_CREDS: 1235 OPTSET(UNP_WANTCRED); 1236 break; 1237 1238 case LOCAL_CONNWAIT: 1239 OPTSET(UNP_CONNWAIT); 1240 break; 1241 1242 default: 1243 break; 1244 } 1245 break; 1246 #undef OPTSET 1247 default: 1248 error = ENOPROTOOPT; 1249 break; 1250 } 1251 break; 1252 1253 default: 1254 error = EOPNOTSUPP; 1255 break; 1256 } 1257 return (error); 1258 } 1259 1260 static int 1261 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1262 { 1263 1264 return (unp_connectat(AT_FDCWD, so, nam, td)); 1265 } 1266 1267 static int 1268 unp_connectat(int fd, struct socket *so, struct sockaddr *nam, 1269 struct thread *td) 1270 { 1271 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1272 struct vnode *vp; 1273 struct socket *so2, *so3; 1274 struct unpcb *unp, *unp2, *unp3; 1275 struct nameidata nd; 1276 char buf[SOCK_MAXADDRLEN]; 1277 struct sockaddr *sa; 1278 cap_rights_t rights; 1279 int error, len; 1280 1281 UNP_LINK_WLOCK_ASSERT(); 1282 1283 unp = sotounpcb(so); 1284 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1285 1286 if (nam->sa_len > sizeof(struct sockaddr_un)) 1287 return (EINVAL); 1288 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1289 if (len <= 0) 1290 return (EINVAL); 1291 bcopy(soun->sun_path, buf, len); 1292 buf[len] = 0; 1293 1294 UNP_PCB_LOCK(unp); 1295 if (unp->unp_flags & UNP_CONNECTING) { 1296 UNP_PCB_UNLOCK(unp); 1297 return (EALREADY); 1298 } 1299 UNP_LINK_WUNLOCK(); 1300 unp->unp_flags |= UNP_CONNECTING; 1301 UNP_PCB_UNLOCK(unp); 1302 1303 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1304 NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF, 1305 UIO_SYSSPACE, buf, fd, cap_rights_init(&rights, CAP_CONNECTAT), td); 1306 error = namei(&nd); 1307 if (error) 1308 vp = NULL; 1309 else 1310 vp = nd.ni_vp; 1311 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1312 NDFREE(&nd, NDF_ONLY_PNBUF); 1313 if (error) 1314 goto bad; 1315 1316 if (vp->v_type != VSOCK) { 1317 error = ENOTSOCK; 1318 goto bad; 1319 } 1320 #ifdef MAC 1321 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1322 if (error) 1323 goto bad; 1324 #endif 1325 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1326 if (error) 1327 goto bad; 1328 1329 unp = sotounpcb(so); 1330 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1331 1332 /* 1333 * Lock linkage lock for two reasons: make sure v_socket is stable, 1334 * and to protect simultaneous locking of multiple pcbs. 1335 */ 1336 UNP_LINK_WLOCK(); 1337 VOP_UNP_CONNECT(vp, &so2); 1338 if (so2 == NULL) { 1339 error = ECONNREFUSED; 1340 goto bad2; 1341 } 1342 if (so->so_type != so2->so_type) { 1343 error = EPROTOTYPE; 1344 goto bad2; 1345 } 1346 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1347 if (so2->so_options & SO_ACCEPTCONN) { 1348 CURVNET_SET(so2->so_vnet); 1349 so3 = sonewconn(so2, 0); 1350 CURVNET_RESTORE(); 1351 } else 1352 so3 = NULL; 1353 if (so3 == NULL) { 1354 error = ECONNREFUSED; 1355 goto bad2; 1356 } 1357 unp = sotounpcb(so); 1358 unp2 = sotounpcb(so2); 1359 unp3 = sotounpcb(so3); 1360 UNP_PCB_LOCK(unp); 1361 UNP_PCB_LOCK(unp2); 1362 UNP_PCB_LOCK(unp3); 1363 if (unp2->unp_addr != NULL) { 1364 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1365 unp3->unp_addr = (struct sockaddr_un *) sa; 1366 sa = NULL; 1367 } 1368 1369 /* 1370 * The connector's (client's) credentials are copied from its 1371 * process structure at the time of connect() (which is now). 1372 */ 1373 cru2x(td->td_ucred, &unp3->unp_peercred); 1374 unp3->unp_flags |= UNP_HAVEPC; 1375 1376 /* 1377 * The receiver's (server's) credentials are copied from the 1378 * unp_peercred member of socket on which the former called 1379 * listen(); uipc_listen() cached that process's credentials 1380 * at that time so we can use them now. 1381 */ 1382 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1383 ("unp_connect: listener without cached peercred")); 1384 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1385 sizeof(unp->unp_peercred)); 1386 unp->unp_flags |= UNP_HAVEPC; 1387 if (unp2->unp_flags & UNP_WANTCRED) 1388 unp3->unp_flags |= UNP_WANTCRED; 1389 UNP_PCB_UNLOCK(unp3); 1390 UNP_PCB_UNLOCK(unp2); 1391 UNP_PCB_UNLOCK(unp); 1392 #ifdef MAC 1393 mac_socketpeer_set_from_socket(so, so3); 1394 mac_socketpeer_set_from_socket(so3, so); 1395 #endif 1396 1397 so2 = so3; 1398 } 1399 unp = sotounpcb(so); 1400 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1401 unp2 = sotounpcb(so2); 1402 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL")); 1403 UNP_PCB_LOCK(unp); 1404 UNP_PCB_LOCK(unp2); 1405 error = unp_connect2(so, so2, PRU_CONNECT); 1406 UNP_PCB_UNLOCK(unp2); 1407 UNP_PCB_UNLOCK(unp); 1408 bad2: 1409 UNP_LINK_WUNLOCK(); 1410 bad: 1411 if (vp != NULL) 1412 vput(vp); 1413 free(sa, M_SONAME); 1414 UNP_LINK_WLOCK(); 1415 UNP_PCB_LOCK(unp); 1416 unp->unp_flags &= ~UNP_CONNECTING; 1417 UNP_PCB_UNLOCK(unp); 1418 return (error); 1419 } 1420 1421 static int 1422 unp_connect2(struct socket *so, struct socket *so2, int req) 1423 { 1424 struct unpcb *unp; 1425 struct unpcb *unp2; 1426 1427 unp = sotounpcb(so); 1428 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1429 unp2 = sotounpcb(so2); 1430 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1431 1432 UNP_LINK_WLOCK_ASSERT(); 1433 UNP_PCB_LOCK_ASSERT(unp); 1434 UNP_PCB_LOCK_ASSERT(unp2); 1435 1436 if (so2->so_type != so->so_type) 1437 return (EPROTOTYPE); 1438 unp->unp_conn = unp2; 1439 1440 switch (so->so_type) { 1441 case SOCK_DGRAM: 1442 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1443 soisconnected(so); 1444 break; 1445 1446 case SOCK_STREAM: 1447 case SOCK_SEQPACKET: 1448 unp2->unp_conn = unp; 1449 if (req == PRU_CONNECT && 1450 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1451 soisconnecting(so); 1452 else 1453 soisconnected(so); 1454 soisconnected(so2); 1455 break; 1456 1457 default: 1458 panic("unp_connect2"); 1459 } 1460 return (0); 1461 } 1462 1463 static void 1464 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1465 { 1466 struct socket *so; 1467 1468 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1469 1470 UNP_LINK_WLOCK_ASSERT(); 1471 UNP_PCB_LOCK_ASSERT(unp); 1472 UNP_PCB_LOCK_ASSERT(unp2); 1473 1474 unp->unp_conn = NULL; 1475 switch (unp->unp_socket->so_type) { 1476 case SOCK_DGRAM: 1477 LIST_REMOVE(unp, unp_reflink); 1478 so = unp->unp_socket; 1479 SOCK_LOCK(so); 1480 so->so_state &= ~SS_ISCONNECTED; 1481 SOCK_UNLOCK(so); 1482 break; 1483 1484 case SOCK_STREAM: 1485 case SOCK_SEQPACKET: 1486 soisdisconnected(unp->unp_socket); 1487 unp2->unp_conn = NULL; 1488 soisdisconnected(unp2->unp_socket); 1489 break; 1490 } 1491 } 1492 1493 /* 1494 * unp_pcblist() walks the global list of struct unpcb's to generate a 1495 * pointer list, bumping the refcount on each unpcb. It then copies them out 1496 * sequentially, validating the generation number on each to see if it has 1497 * been detached. All of this is necessary because copyout() may sleep on 1498 * disk I/O. 1499 */ 1500 static int 1501 unp_pcblist(SYSCTL_HANDLER_ARGS) 1502 { 1503 int error, i, n; 1504 int freeunp; 1505 struct unpcb *unp, **unp_list; 1506 unp_gen_t gencnt; 1507 struct xunpgen *xug; 1508 struct unp_head *head; 1509 struct xunpcb *xu; 1510 1511 switch ((intptr_t)arg1) { 1512 case SOCK_STREAM: 1513 head = &unp_shead; 1514 break; 1515 1516 case SOCK_DGRAM: 1517 head = &unp_dhead; 1518 break; 1519 1520 case SOCK_SEQPACKET: 1521 head = &unp_sphead; 1522 break; 1523 1524 default: 1525 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1526 } 1527 1528 /* 1529 * The process of preparing the PCB list is too time-consuming and 1530 * resource-intensive to repeat twice on every request. 1531 */ 1532 if (req->oldptr == NULL) { 1533 n = unp_count; 1534 req->oldidx = 2 * (sizeof *xug) 1535 + (n + n/8) * sizeof(struct xunpcb); 1536 return (0); 1537 } 1538 1539 if (req->newptr != NULL) 1540 return (EPERM); 1541 1542 /* 1543 * OK, now we're committed to doing something. 1544 */ 1545 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1546 UNP_LIST_LOCK(); 1547 gencnt = unp_gencnt; 1548 n = unp_count; 1549 UNP_LIST_UNLOCK(); 1550 1551 xug->xug_len = sizeof *xug; 1552 xug->xug_count = n; 1553 xug->xug_gen = gencnt; 1554 xug->xug_sogen = so_gencnt; 1555 error = SYSCTL_OUT(req, xug, sizeof *xug); 1556 if (error) { 1557 free(xug, M_TEMP); 1558 return (error); 1559 } 1560 1561 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1562 1563 UNP_LIST_LOCK(); 1564 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1565 unp = LIST_NEXT(unp, unp_link)) { 1566 UNP_PCB_LOCK(unp); 1567 if (unp->unp_gencnt <= gencnt) { 1568 if (cr_cansee(req->td->td_ucred, 1569 unp->unp_socket->so_cred)) { 1570 UNP_PCB_UNLOCK(unp); 1571 continue; 1572 } 1573 unp_list[i++] = unp; 1574 unp->unp_refcount++; 1575 } 1576 UNP_PCB_UNLOCK(unp); 1577 } 1578 UNP_LIST_UNLOCK(); 1579 n = i; /* In case we lost some during malloc. */ 1580 1581 error = 0; 1582 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1583 for (i = 0; i < n; i++) { 1584 unp = unp_list[i]; 1585 UNP_PCB_LOCK(unp); 1586 unp->unp_refcount--; 1587 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) { 1588 xu->xu_len = sizeof *xu; 1589 xu->xu_unpp = unp; 1590 /* 1591 * XXX - need more locking here to protect against 1592 * connect/disconnect races for SMP. 1593 */ 1594 if (unp->unp_addr != NULL) 1595 bcopy(unp->unp_addr, &xu->xu_addr, 1596 unp->unp_addr->sun_len); 1597 if (unp->unp_conn != NULL && 1598 unp->unp_conn->unp_addr != NULL) 1599 bcopy(unp->unp_conn->unp_addr, 1600 &xu->xu_caddr, 1601 unp->unp_conn->unp_addr->sun_len); 1602 bcopy(unp, &xu->xu_unp, sizeof *unp); 1603 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1604 UNP_PCB_UNLOCK(unp); 1605 error = SYSCTL_OUT(req, xu, sizeof *xu); 1606 } else { 1607 freeunp = (unp->unp_refcount == 0); 1608 UNP_PCB_UNLOCK(unp); 1609 if (freeunp) { 1610 UNP_PCB_LOCK_DESTROY(unp); 1611 uma_zfree(unp_zone, unp); 1612 } 1613 } 1614 } 1615 free(xu, M_TEMP); 1616 if (!error) { 1617 /* 1618 * Give the user an updated idea of our state. If the 1619 * generation differs from what we told her before, she knows 1620 * that something happened while we were processing this 1621 * request, and it might be necessary to retry. 1622 */ 1623 xug->xug_gen = unp_gencnt; 1624 xug->xug_sogen = so_gencnt; 1625 xug->xug_count = unp_count; 1626 error = SYSCTL_OUT(req, xug, sizeof *xug); 1627 } 1628 free(unp_list, M_TEMP); 1629 free(xug, M_TEMP); 1630 return (error); 1631 } 1632 1633 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1634 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1635 "List of active local datagram sockets"); 1636 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1637 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1638 "List of active local stream sockets"); 1639 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1640 CTLTYPE_OPAQUE | CTLFLAG_RD, 1641 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1642 "List of active local seqpacket sockets"); 1643 1644 static void 1645 unp_shutdown(struct unpcb *unp) 1646 { 1647 struct unpcb *unp2; 1648 struct socket *so; 1649 1650 UNP_LINK_WLOCK_ASSERT(); 1651 UNP_PCB_LOCK_ASSERT(unp); 1652 1653 unp2 = unp->unp_conn; 1654 if ((unp->unp_socket->so_type == SOCK_STREAM || 1655 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1656 so = unp2->unp_socket; 1657 if (so != NULL) 1658 socantrcvmore(so); 1659 } 1660 } 1661 1662 static void 1663 unp_drop(struct unpcb *unp, int errno) 1664 { 1665 struct socket *so = unp->unp_socket; 1666 struct unpcb *unp2; 1667 1668 UNP_LINK_WLOCK_ASSERT(); 1669 UNP_PCB_LOCK_ASSERT(unp); 1670 1671 so->so_error = errno; 1672 unp2 = unp->unp_conn; 1673 if (unp2 == NULL) 1674 return; 1675 UNP_PCB_LOCK(unp2); 1676 unp_disconnect(unp, unp2); 1677 UNP_PCB_UNLOCK(unp2); 1678 } 1679 1680 static void 1681 unp_freerights(struct filedescent **fdep, int fdcount) 1682 { 1683 struct file *fp; 1684 int i; 1685 1686 KASSERT(fdcount > 0, ("%s: fdcount %d", __func__, fdcount)); 1687 1688 for (i = 0; i < fdcount; i++) { 1689 fp = fdep[i]->fde_file; 1690 filecaps_free(&fdep[i]->fde_caps); 1691 unp_discard(fp); 1692 } 1693 free(fdep[0], M_FILECAPS); 1694 } 1695 1696 static int 1697 unp_externalize(struct mbuf *control, struct mbuf **controlp, int flags) 1698 { 1699 struct thread *td = curthread; /* XXX */ 1700 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1701 int i; 1702 int *fdp; 1703 struct filedesc *fdesc = td->td_proc->p_fd; 1704 struct filedescent *fde, **fdep; 1705 void *data; 1706 socklen_t clen = control->m_len, datalen; 1707 int error, newfds; 1708 u_int newlen; 1709 1710 UNP_LINK_UNLOCK_ASSERT(); 1711 1712 error = 0; 1713 if (controlp != NULL) /* controlp == NULL => free control messages */ 1714 *controlp = NULL; 1715 while (cm != NULL) { 1716 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1717 error = EINVAL; 1718 break; 1719 } 1720 data = CMSG_DATA(cm); 1721 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1722 if (cm->cmsg_level == SOL_SOCKET 1723 && cm->cmsg_type == SCM_RIGHTS) { 1724 newfds = datalen / sizeof(*fdep); 1725 if (newfds == 0) 1726 goto next; 1727 fdep = data; 1728 1729 /* If we're not outputting the descriptors free them. */ 1730 if (error || controlp == NULL) { 1731 unp_freerights(fdep, newfds); 1732 goto next; 1733 } 1734 FILEDESC_XLOCK(fdesc); 1735 1736 /* 1737 * Now change each pointer to an fd in the global 1738 * table to an integer that is the index to the local 1739 * fd table entry that we set up to point to the 1740 * global one we are transferring. 1741 */ 1742 newlen = newfds * sizeof(int); 1743 *controlp = sbcreatecontrol(NULL, newlen, 1744 SCM_RIGHTS, SOL_SOCKET); 1745 if (*controlp == NULL) { 1746 FILEDESC_XUNLOCK(fdesc); 1747 error = E2BIG; 1748 unp_freerights(fdep, newfds); 1749 goto next; 1750 } 1751 1752 fdp = (int *) 1753 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1754 if (fdallocn(td, 0, fdp, newfds) != 0) { 1755 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1756 error = EMSGSIZE; 1757 unp_freerights(fdep, newfds); 1758 m_freem(*controlp); 1759 *controlp = NULL; 1760 goto next; 1761 } 1762 for (i = 0; i < newfds; i++, fdp++) { 1763 fde = &fdesc->fd_ofiles[*fdp]; 1764 fde->fde_file = fdep[i]->fde_file; 1765 filecaps_move(&fdep[i]->fde_caps, 1766 &fde->fde_caps); 1767 if ((flags & MSG_CMSG_CLOEXEC) != 0) 1768 fde->fde_flags |= UF_EXCLOSE; 1769 unp_externalize_fp(fde->fde_file); 1770 } 1771 FILEDESC_XUNLOCK(fdesc); 1772 free(fdep[0], M_FILECAPS); 1773 } else { 1774 /* We can just copy anything else across. */ 1775 if (error || controlp == NULL) 1776 goto next; 1777 *controlp = sbcreatecontrol(NULL, datalen, 1778 cm->cmsg_type, cm->cmsg_level); 1779 if (*controlp == NULL) { 1780 error = ENOBUFS; 1781 goto next; 1782 } 1783 bcopy(data, 1784 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1785 datalen); 1786 } 1787 controlp = &(*controlp)->m_next; 1788 1789 next: 1790 if (CMSG_SPACE(datalen) < clen) { 1791 clen -= CMSG_SPACE(datalen); 1792 cm = (struct cmsghdr *) 1793 ((caddr_t)cm + CMSG_SPACE(datalen)); 1794 } else { 1795 clen = 0; 1796 cm = NULL; 1797 } 1798 } 1799 1800 m_freem(control); 1801 return (error); 1802 } 1803 1804 static void 1805 unp_zone_change(void *tag) 1806 { 1807 1808 uma_zone_set_max(unp_zone, maxsockets); 1809 } 1810 1811 static void 1812 unp_init(void) 1813 { 1814 1815 #ifdef VIMAGE 1816 if (!IS_DEFAULT_VNET(curvnet)) 1817 return; 1818 #endif 1819 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1820 NULL, NULL, UMA_ALIGN_PTR, 0); 1821 if (unp_zone == NULL) 1822 panic("unp_init"); 1823 uma_zone_set_max(unp_zone, maxsockets); 1824 uma_zone_set_warning(unp_zone, "kern.ipc.maxsockets limit reached"); 1825 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 1826 NULL, EVENTHANDLER_PRI_ANY); 1827 LIST_INIT(&unp_dhead); 1828 LIST_INIT(&unp_shead); 1829 LIST_INIT(&unp_sphead); 1830 SLIST_INIT(&unp_defers); 1831 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 1832 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 1833 UNP_LINK_LOCK_INIT(); 1834 UNP_LIST_LOCK_INIT(); 1835 UNP_DEFERRED_LOCK_INIT(); 1836 } 1837 1838 static int 1839 unp_internalize(struct mbuf **controlp, struct thread *td) 1840 { 1841 struct mbuf *control = *controlp; 1842 struct proc *p = td->td_proc; 1843 struct filedesc *fdesc = p->p_fd; 1844 struct bintime *bt; 1845 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1846 struct cmsgcred *cmcred; 1847 struct filedescent *fde, **fdep, *fdev; 1848 struct file *fp; 1849 struct timeval *tv; 1850 int i, fd, *fdp; 1851 void *data; 1852 socklen_t clen = control->m_len, datalen; 1853 int error, oldfds; 1854 u_int newlen; 1855 1856 UNP_LINK_UNLOCK_ASSERT(); 1857 1858 error = 0; 1859 *controlp = NULL; 1860 while (cm != NULL) { 1861 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1862 || cm->cmsg_len > clen) { 1863 error = EINVAL; 1864 goto out; 1865 } 1866 data = CMSG_DATA(cm); 1867 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1868 1869 switch (cm->cmsg_type) { 1870 /* 1871 * Fill in credential information. 1872 */ 1873 case SCM_CREDS: 1874 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1875 SCM_CREDS, SOL_SOCKET); 1876 if (*controlp == NULL) { 1877 error = ENOBUFS; 1878 goto out; 1879 } 1880 cmcred = (struct cmsgcred *) 1881 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1882 cmcred->cmcred_pid = p->p_pid; 1883 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1884 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1885 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1886 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1887 CMGROUP_MAX); 1888 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1889 cmcred->cmcred_groups[i] = 1890 td->td_ucred->cr_groups[i]; 1891 break; 1892 1893 case SCM_RIGHTS: 1894 oldfds = datalen / sizeof (int); 1895 if (oldfds == 0) 1896 break; 1897 /* 1898 * Check that all the FDs passed in refer to legal 1899 * files. If not, reject the entire operation. 1900 */ 1901 fdp = data; 1902 FILEDESC_SLOCK(fdesc); 1903 for (i = 0; i < oldfds; i++) { 1904 fd = *fdp++; 1905 if (fget_locked(fdesc, fd) == NULL) { 1906 FILEDESC_SUNLOCK(fdesc); 1907 error = EBADF; 1908 goto out; 1909 } 1910 fp = fdesc->fd_ofiles[fd].fde_file; 1911 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1912 FILEDESC_SUNLOCK(fdesc); 1913 error = EOPNOTSUPP; 1914 goto out; 1915 } 1916 1917 } 1918 1919 /* 1920 * Now replace the integer FDs with pointers to the 1921 * file structure and capability rights. 1922 */ 1923 newlen = oldfds * sizeof(fdep[0]); 1924 *controlp = sbcreatecontrol(NULL, newlen, 1925 SCM_RIGHTS, SOL_SOCKET); 1926 if (*controlp == NULL) { 1927 FILEDESC_SUNLOCK(fdesc); 1928 error = E2BIG; 1929 goto out; 1930 } 1931 fdp = data; 1932 fdep = (struct filedescent **) 1933 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1934 fdev = malloc(sizeof(*fdev) * oldfds, M_FILECAPS, 1935 M_WAITOK); 1936 for (i = 0; i < oldfds; i++, fdev++, fdp++) { 1937 fde = &fdesc->fd_ofiles[*fdp]; 1938 fdep[i] = fdev; 1939 fdep[i]->fde_file = fde->fde_file; 1940 filecaps_copy(&fde->fde_caps, 1941 &fdep[i]->fde_caps); 1942 unp_internalize_fp(fdep[i]->fde_file); 1943 } 1944 FILEDESC_SUNLOCK(fdesc); 1945 break; 1946 1947 case SCM_TIMESTAMP: 1948 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1949 SCM_TIMESTAMP, SOL_SOCKET); 1950 if (*controlp == NULL) { 1951 error = ENOBUFS; 1952 goto out; 1953 } 1954 tv = (struct timeval *) 1955 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1956 microtime(tv); 1957 break; 1958 1959 case SCM_BINTIME: 1960 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 1961 SCM_BINTIME, SOL_SOCKET); 1962 if (*controlp == NULL) { 1963 error = ENOBUFS; 1964 goto out; 1965 } 1966 bt = (struct bintime *) 1967 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1968 bintime(bt); 1969 break; 1970 1971 default: 1972 error = EINVAL; 1973 goto out; 1974 } 1975 1976 controlp = &(*controlp)->m_next; 1977 if (CMSG_SPACE(datalen) < clen) { 1978 clen -= CMSG_SPACE(datalen); 1979 cm = (struct cmsghdr *) 1980 ((caddr_t)cm + CMSG_SPACE(datalen)); 1981 } else { 1982 clen = 0; 1983 cm = NULL; 1984 } 1985 } 1986 1987 out: 1988 m_freem(control); 1989 return (error); 1990 } 1991 1992 static struct mbuf * 1993 unp_addsockcred(struct thread *td, struct mbuf *control) 1994 { 1995 struct mbuf *m, *n, *n_prev; 1996 struct sockcred *sc; 1997 const struct cmsghdr *cm; 1998 int ngroups; 1999 int i; 2000 2001 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 2002 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 2003 if (m == NULL) 2004 return (control); 2005 2006 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 2007 sc->sc_uid = td->td_ucred->cr_ruid; 2008 sc->sc_euid = td->td_ucred->cr_uid; 2009 sc->sc_gid = td->td_ucred->cr_rgid; 2010 sc->sc_egid = td->td_ucred->cr_gid; 2011 sc->sc_ngroups = ngroups; 2012 for (i = 0; i < sc->sc_ngroups; i++) 2013 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 2014 2015 /* 2016 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 2017 * created SCM_CREDS control message (struct sockcred) has another 2018 * format. 2019 */ 2020 if (control != NULL) 2021 for (n = control, n_prev = NULL; n != NULL;) { 2022 cm = mtod(n, struct cmsghdr *); 2023 if (cm->cmsg_level == SOL_SOCKET && 2024 cm->cmsg_type == SCM_CREDS) { 2025 if (n_prev == NULL) 2026 control = n->m_next; 2027 else 2028 n_prev->m_next = n->m_next; 2029 n = m_free(n); 2030 } else { 2031 n_prev = n; 2032 n = n->m_next; 2033 } 2034 } 2035 2036 /* Prepend it to the head. */ 2037 m->m_next = control; 2038 return (m); 2039 } 2040 2041 static struct unpcb * 2042 fptounp(struct file *fp) 2043 { 2044 struct socket *so; 2045 2046 if (fp->f_type != DTYPE_SOCKET) 2047 return (NULL); 2048 if ((so = fp->f_data) == NULL) 2049 return (NULL); 2050 if (so->so_proto->pr_domain != &localdomain) 2051 return (NULL); 2052 return sotounpcb(so); 2053 } 2054 2055 static void 2056 unp_discard(struct file *fp) 2057 { 2058 struct unp_defer *dr; 2059 2060 if (unp_externalize_fp(fp)) { 2061 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2062 dr->ud_fp = fp; 2063 UNP_DEFERRED_LOCK(); 2064 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2065 UNP_DEFERRED_UNLOCK(); 2066 atomic_add_int(&unp_defers_count, 1); 2067 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2068 } else 2069 (void) closef(fp, (struct thread *)NULL); 2070 } 2071 2072 static void 2073 unp_process_defers(void *arg __unused, int pending) 2074 { 2075 struct unp_defer *dr; 2076 SLIST_HEAD(, unp_defer) drl; 2077 int count; 2078 2079 SLIST_INIT(&drl); 2080 for (;;) { 2081 UNP_DEFERRED_LOCK(); 2082 if (SLIST_FIRST(&unp_defers) == NULL) { 2083 UNP_DEFERRED_UNLOCK(); 2084 break; 2085 } 2086 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2087 UNP_DEFERRED_UNLOCK(); 2088 count = 0; 2089 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2090 SLIST_REMOVE_HEAD(&drl, ud_link); 2091 closef(dr->ud_fp, NULL); 2092 free(dr, M_TEMP); 2093 count++; 2094 } 2095 atomic_add_int(&unp_defers_count, -count); 2096 } 2097 } 2098 2099 static void 2100 unp_internalize_fp(struct file *fp) 2101 { 2102 struct unpcb *unp; 2103 2104 UNP_LINK_WLOCK(); 2105 if ((unp = fptounp(fp)) != NULL) { 2106 unp->unp_file = fp; 2107 unp->unp_msgcount++; 2108 } 2109 fhold(fp); 2110 unp_rights++; 2111 UNP_LINK_WUNLOCK(); 2112 } 2113 2114 static int 2115 unp_externalize_fp(struct file *fp) 2116 { 2117 struct unpcb *unp; 2118 int ret; 2119 2120 UNP_LINK_WLOCK(); 2121 if ((unp = fptounp(fp)) != NULL) { 2122 unp->unp_msgcount--; 2123 ret = 1; 2124 } else 2125 ret = 0; 2126 unp_rights--; 2127 UNP_LINK_WUNLOCK(); 2128 return (ret); 2129 } 2130 2131 /* 2132 * unp_defer indicates whether additional work has been defered for a future 2133 * pass through unp_gc(). It is thread local and does not require explicit 2134 * synchronization. 2135 */ 2136 static int unp_marked; 2137 static int unp_unreachable; 2138 2139 static void 2140 unp_accessable(struct filedescent **fdep, int fdcount) 2141 { 2142 struct unpcb *unp; 2143 struct file *fp; 2144 int i; 2145 2146 for (i = 0; i < fdcount; i++) { 2147 fp = fdep[i]->fde_file; 2148 if ((unp = fptounp(fp)) == NULL) 2149 continue; 2150 if (unp->unp_gcflag & UNPGC_REF) 2151 continue; 2152 unp->unp_gcflag &= ~UNPGC_DEAD; 2153 unp->unp_gcflag |= UNPGC_REF; 2154 unp_marked++; 2155 } 2156 } 2157 2158 static void 2159 unp_gc_process(struct unpcb *unp) 2160 { 2161 struct socket *soa; 2162 struct socket *so; 2163 struct file *fp; 2164 2165 /* Already processed. */ 2166 if (unp->unp_gcflag & UNPGC_SCANNED) 2167 return; 2168 fp = unp->unp_file; 2169 2170 /* 2171 * Check for a socket potentially in a cycle. It must be in a 2172 * queue as indicated by msgcount, and this must equal the file 2173 * reference count. Note that when msgcount is 0 the file is NULL. 2174 */ 2175 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2176 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2177 unp->unp_gcflag |= UNPGC_DEAD; 2178 unp_unreachable++; 2179 return; 2180 } 2181 2182 /* 2183 * Mark all sockets we reference with RIGHTS. 2184 */ 2185 so = unp->unp_socket; 2186 SOCKBUF_LOCK(&so->so_rcv); 2187 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2188 SOCKBUF_UNLOCK(&so->so_rcv); 2189 2190 /* 2191 * Mark all sockets in our accept queue. 2192 */ 2193 ACCEPT_LOCK(); 2194 TAILQ_FOREACH(soa, &so->so_comp, so_list) { 2195 SOCKBUF_LOCK(&soa->so_rcv); 2196 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2197 SOCKBUF_UNLOCK(&soa->so_rcv); 2198 } 2199 ACCEPT_UNLOCK(); 2200 unp->unp_gcflag |= UNPGC_SCANNED; 2201 } 2202 2203 static int unp_recycled; 2204 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2205 "Number of unreachable sockets claimed by the garbage collector."); 2206 2207 static int unp_taskcount; 2208 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2209 "Number of times the garbage collector has run."); 2210 2211 static void 2212 unp_gc(__unused void *arg, int pending) 2213 { 2214 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2215 NULL }; 2216 struct unp_head **head; 2217 struct file *f, **unref; 2218 struct unpcb *unp; 2219 int i, total; 2220 2221 unp_taskcount++; 2222 UNP_LIST_LOCK(); 2223 /* 2224 * First clear all gc flags from previous runs. 2225 */ 2226 for (head = heads; *head != NULL; head++) 2227 LIST_FOREACH(unp, *head, unp_link) 2228 unp->unp_gcflag = 0; 2229 2230 /* 2231 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2232 * is reachable all of the sockets it references are reachable. 2233 * Stop the scan once we do a complete loop without discovering 2234 * a new reachable socket. 2235 */ 2236 do { 2237 unp_unreachable = 0; 2238 unp_marked = 0; 2239 for (head = heads; *head != NULL; head++) 2240 LIST_FOREACH(unp, *head, unp_link) 2241 unp_gc_process(unp); 2242 } while (unp_marked); 2243 UNP_LIST_UNLOCK(); 2244 if (unp_unreachable == 0) 2245 return; 2246 2247 /* 2248 * Allocate space for a local list of dead unpcbs. 2249 */ 2250 unref = malloc(unp_unreachable * sizeof(struct file *), 2251 M_TEMP, M_WAITOK); 2252 2253 /* 2254 * Iterate looking for sockets which have been specifically marked 2255 * as as unreachable and store them locally. 2256 */ 2257 UNP_LINK_RLOCK(); 2258 UNP_LIST_LOCK(); 2259 for (total = 0, head = heads; *head != NULL; head++) 2260 LIST_FOREACH(unp, *head, unp_link) 2261 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2262 f = unp->unp_file; 2263 if (unp->unp_msgcount == 0 || f == NULL || 2264 f->f_count != unp->unp_msgcount) 2265 continue; 2266 unref[total++] = f; 2267 fhold(f); 2268 KASSERT(total <= unp_unreachable, 2269 ("unp_gc: incorrect unreachable count.")); 2270 } 2271 UNP_LIST_UNLOCK(); 2272 UNP_LINK_RUNLOCK(); 2273 2274 /* 2275 * Now flush all sockets, free'ing rights. This will free the 2276 * struct files associated with these sockets but leave each socket 2277 * with one remaining ref. 2278 */ 2279 for (i = 0; i < total; i++) { 2280 struct socket *so; 2281 2282 so = unref[i]->f_data; 2283 CURVNET_SET(so->so_vnet); 2284 sorflush(so); 2285 CURVNET_RESTORE(); 2286 } 2287 2288 /* 2289 * And finally release the sockets so they can be reclaimed. 2290 */ 2291 for (i = 0; i < total; i++) 2292 fdrop(unref[i], NULL); 2293 unp_recycled += total; 2294 free(unref, M_TEMP); 2295 } 2296 2297 static void 2298 unp_dispose(struct mbuf *m) 2299 { 2300 2301 if (m) 2302 unp_scan(m, unp_freerights); 2303 } 2304 2305 static void 2306 unp_scan(struct mbuf *m0, void (*op)(struct filedescent **, int)) 2307 { 2308 struct mbuf *m; 2309 struct cmsghdr *cm; 2310 void *data; 2311 socklen_t clen, datalen; 2312 2313 while (m0 != NULL) { 2314 for (m = m0; m; m = m->m_next) { 2315 if (m->m_type != MT_CONTROL) 2316 continue; 2317 2318 cm = mtod(m, struct cmsghdr *); 2319 clen = m->m_len; 2320 2321 while (cm != NULL) { 2322 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2323 break; 2324 2325 data = CMSG_DATA(cm); 2326 datalen = (caddr_t)cm + cm->cmsg_len 2327 - (caddr_t)data; 2328 2329 if (cm->cmsg_level == SOL_SOCKET && 2330 cm->cmsg_type == SCM_RIGHTS) { 2331 (*op)(data, datalen / 2332 sizeof(struct filedescent *)); 2333 } 2334 2335 if (CMSG_SPACE(datalen) < clen) { 2336 clen -= CMSG_SPACE(datalen); 2337 cm = (struct cmsghdr *) 2338 ((caddr_t)cm + CMSG_SPACE(datalen)); 2339 } else { 2340 clen = 0; 2341 cm = NULL; 2342 } 2343 } 2344 } 2345 m0 = m0->m_act; 2346 } 2347 } 2348 2349 /* 2350 * A helper function called by VFS before socket-type vnode reclamation. 2351 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2352 * use count. 2353 */ 2354 void 2355 vfs_unp_reclaim(struct vnode *vp) 2356 { 2357 struct socket *so; 2358 struct unpcb *unp; 2359 int active; 2360 2361 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2362 KASSERT(vp->v_type == VSOCK, 2363 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2364 2365 active = 0; 2366 UNP_LINK_WLOCK(); 2367 VOP_UNP_CONNECT(vp, &so); 2368 if (so == NULL) 2369 goto done; 2370 unp = sotounpcb(so); 2371 if (unp == NULL) 2372 goto done; 2373 UNP_PCB_LOCK(unp); 2374 if (unp->unp_vnode == vp) { 2375 VOP_UNP_DETACH(vp); 2376 unp->unp_vnode = NULL; 2377 active = 1; 2378 } 2379 UNP_PCB_UNLOCK(unp); 2380 done: 2381 UNP_LINK_WUNLOCK(); 2382 if (active) 2383 vunref(vp); 2384 } 2385 2386 #ifdef DDB 2387 static void 2388 db_print_indent(int indent) 2389 { 2390 int i; 2391 2392 for (i = 0; i < indent; i++) 2393 db_printf(" "); 2394 } 2395 2396 static void 2397 db_print_unpflags(int unp_flags) 2398 { 2399 int comma; 2400 2401 comma = 0; 2402 if (unp_flags & UNP_HAVEPC) { 2403 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2404 comma = 1; 2405 } 2406 if (unp_flags & UNP_HAVEPCCACHED) { 2407 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : ""); 2408 comma = 1; 2409 } 2410 if (unp_flags & UNP_WANTCRED) { 2411 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2412 comma = 1; 2413 } 2414 if (unp_flags & UNP_CONNWAIT) { 2415 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2416 comma = 1; 2417 } 2418 if (unp_flags & UNP_CONNECTING) { 2419 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2420 comma = 1; 2421 } 2422 if (unp_flags & UNP_BINDING) { 2423 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2424 comma = 1; 2425 } 2426 } 2427 2428 static void 2429 db_print_xucred(int indent, struct xucred *xu) 2430 { 2431 int comma, i; 2432 2433 db_print_indent(indent); 2434 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2435 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2436 db_print_indent(indent); 2437 db_printf("cr_groups: "); 2438 comma = 0; 2439 for (i = 0; i < xu->cr_ngroups; i++) { 2440 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2441 comma = 1; 2442 } 2443 db_printf("\n"); 2444 } 2445 2446 static void 2447 db_print_unprefs(int indent, struct unp_head *uh) 2448 { 2449 struct unpcb *unp; 2450 int counter; 2451 2452 counter = 0; 2453 LIST_FOREACH(unp, uh, unp_reflink) { 2454 if (counter % 4 == 0) 2455 db_print_indent(indent); 2456 db_printf("%p ", unp); 2457 if (counter % 4 == 3) 2458 db_printf("\n"); 2459 counter++; 2460 } 2461 if (counter != 0 && counter % 4 != 0) 2462 db_printf("\n"); 2463 } 2464 2465 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2466 { 2467 struct unpcb *unp; 2468 2469 if (!have_addr) { 2470 db_printf("usage: show unpcb <addr>\n"); 2471 return; 2472 } 2473 unp = (struct unpcb *)addr; 2474 2475 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2476 unp->unp_vnode); 2477 2478 db_printf("unp_ino: %ju unp_conn: %p\n", (uintmax_t)unp->unp_ino, 2479 unp->unp_conn); 2480 2481 db_printf("unp_refs:\n"); 2482 db_print_unprefs(2, &unp->unp_refs); 2483 2484 /* XXXRW: Would be nice to print the full address, if any. */ 2485 db_printf("unp_addr: %p\n", unp->unp_addr); 2486 2487 db_printf("unp_gencnt: %llu\n", 2488 (unsigned long long)unp->unp_gencnt); 2489 2490 db_printf("unp_flags: %x (", unp->unp_flags); 2491 db_print_unpflags(unp->unp_flags); 2492 db_printf(")\n"); 2493 2494 db_printf("unp_peercred:\n"); 2495 db_print_xucred(2, &unp->unp_peercred); 2496 2497 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2498 } 2499 #endif 2500