Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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sys/kern/uipc_usrreq.c
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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 * distinguish datagram size limits from flow control limits in SEQPACKET 55 * rethink name space problems 56 * need a proper out-of-band 57 */ 58 59 #include <sys/cdefs.h> 60 __FBSDID("$FreeBSD$"); 61 62 #include "opt_ddb.h" 63 64 #include <sys/param.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 /* 105 * Locking key: 106 * (l) Locked using list lock 107 * (g) Locked using linkage lock 108 */ 109 110 static uma_zone_t unp_zone; 111 static unp_gen_t unp_gencnt; /* (l) */ 112 static u_int unp_count; /* (l) Count of local sockets. */ 113 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 114 static int unp_rights; /* (g) File descriptors in flight. */ 115 static struct unp_head unp_shead; /* (l) List of stream sockets. */ 116 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 117 static struct unp_head unp_sphead; /* (l) List of seqpacket sockets. */ 118 119 struct unp_defer { 120 SLIST_ENTRY(unp_defer) ud_link; 121 struct file *ud_fp; 122 }; 123 static SLIST_HEAD(, unp_defer) unp_defers; 124 static int unp_defers_count; 125 126 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 127 128 /* 129 * Garbage collection of cyclic file descriptor/socket references occurs 130 * asynchronously in a taskqueue context in order to avoid recursion and 131 * reentrance in the UNIX domain socket, file descriptor, and socket layer 132 * code. See unp_gc() for a full description. 133 */ 134 static struct timeout_task unp_gc_task; 135 136 /* 137 * The close of unix domain sockets attached as SCM_RIGHTS is 138 * postponed to the taskqueue, to avoid arbitrary recursion depth. 139 * The attached sockets might have another sockets attached. 140 */ 141 static struct task unp_defer_task; 142 143 /* 144 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 145 * stream sockets, although the total for sender and receiver is actually 146 * only PIPSIZ. 147 * 148 * Datagram sockets really use the sendspace as the maximum datagram size, 149 * and don't really want to reserve the sendspace. Their recvspace should be 150 * large enough for at least one max-size datagram plus address. 151 */ 152 #ifndef PIPSIZ 153 #define PIPSIZ 8192 154 #endif 155 static u_long unpst_sendspace = PIPSIZ; 156 static u_long unpst_recvspace = PIPSIZ; 157 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 158 static u_long unpdg_recvspace = 4*1024; 159 static u_long unpsp_sendspace = PIPSIZ; /* really max datagram size */ 160 static u_long unpsp_recvspace = PIPSIZ; 161 162 static SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain"); 163 static SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, 164 "SOCK_STREAM"); 165 static SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM"); 166 static SYSCTL_NODE(_net_local, SOCK_SEQPACKET, seqpacket, CTLFLAG_RW, 0, 167 "SOCK_SEQPACKET"); 168 169 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 170 &unpst_sendspace, 0, "Default stream send space."); 171 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 172 &unpst_recvspace, 0, "Default stream receive space."); 173 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 174 &unpdg_sendspace, 0, "Default datagram send space."); 175 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 176 &unpdg_recvspace, 0, "Default datagram receive space."); 177 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, maxseqpacket, CTLFLAG_RW, 178 &unpsp_sendspace, 0, "Default seqpacket send space."); 179 SYSCTL_ULONG(_net_local_seqpacket, OID_AUTO, recvspace, CTLFLAG_RW, 180 &unpsp_recvspace, 0, "Default seqpacket receive space."); 181 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 182 "File descriptors in flight."); 183 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD, 184 &unp_defers_count, 0, 185 "File descriptors deferred to taskqueue for close."); 186 187 /* 188 * Locking and synchronization: 189 * 190 * Three types of locks exit in the local domain socket implementation: a 191 * global list mutex, a global linkage rwlock, and per-unpcb mutexes. Of the 192 * global locks, the list lock protects the socket count, global generation 193 * number, and stream/datagram global lists. The linkage lock protects the 194 * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be 195 * held exclusively over the acquisition of multiple unpcb locks to prevent 196 * deadlock. 197 * 198 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 199 * allocated in pru_attach() and freed in pru_detach(). The validity of that 200 * pointer is an invariant, so no lock is required to dereference the so_pcb 201 * pointer if a valid socket reference is held by the caller. In practice, 202 * this is always true during operations performed on a socket. Each unpcb 203 * has a back-pointer to its socket, unp_socket, which will be stable under 204 * the same circumstances. 205 * 206 * This pointer may only be safely dereferenced as long as a valid reference 207 * to the unpcb is held. Typically, this reference will be from the socket, 208 * or from another unpcb when the referring unpcb's lock is held (in order 209 * that the reference not be invalidated during use). For example, to follow 210 * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn, 211 * as unp_socket remains valid as long as the reference to unp_conn is valid. 212 * 213 * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual 214 * atomic reads without the lock may be performed "lockless", but more 215 * complex reads and read-modify-writes require the mutex to be held. No 216 * lock order is defined between unpcb locks -- multiple unpcb locks may be 217 * acquired at the same time only when holding the linkage rwlock 218 * exclusively, which prevents deadlocks. 219 * 220 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 221 * protocols, bind() is a non-atomic operation, and connect() requires 222 * potential sleeping in the protocol, due to potentially waiting on local or 223 * distributed file systems. We try to separate "lookup" operations, which 224 * may sleep, and the IPC operations themselves, which typically can occur 225 * with relative atomicity as locks can be held over the entire operation. 226 * 227 * Another tricky issue is simultaneous multi-threaded or multi-process 228 * access to a single UNIX domain socket. These are handled by the flags 229 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 230 * binding, both of which involve dropping UNIX domain socket locks in order 231 * to perform namei() and other file system operations. 232 */ 233 static struct rwlock unp_link_rwlock; 234 static struct mtx unp_list_lock; 235 static struct mtx unp_defers_lock; 236 237 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 238 "unp_link_rwlock") 239 240 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 241 RA_LOCKED) 242 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 243 RA_UNLOCKED) 244 245 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 246 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 247 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 248 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 249 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 250 RA_WLOCKED) 251 252 #define UNP_LIST_LOCK_INIT() mtx_init(&unp_list_lock, \ 253 "unp_list_lock", NULL, MTX_DEF) 254 #define UNP_LIST_LOCK() mtx_lock(&unp_list_lock) 255 #define UNP_LIST_UNLOCK() mtx_unlock(&unp_list_lock) 256 257 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \ 258 "unp_defer", NULL, MTX_DEF) 259 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock) 260 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock) 261 262 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 263 "unp_mtx", "unp_mtx", \ 264 MTX_DUPOK|MTX_DEF|MTX_RECURSE) 265 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 266 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 267 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 268 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 269 270 static int uipc_connect2(struct socket *, struct socket *); 271 static int uipc_ctloutput(struct socket *, struct sockopt *); 272 static int unp_connect(struct socket *, struct sockaddr *, 273 struct thread *); 274 static int unp_connect2(struct socket *so, struct socket *so2, int); 275 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 276 static void unp_dispose(struct mbuf *); 277 static void unp_shutdown(struct unpcb *); 278 static void unp_drop(struct unpcb *, int); 279 static void unp_gc(__unused void *, int); 280 static void unp_scan(struct mbuf *, void (*)(struct file *)); 281 static void unp_discard(struct file *); 282 static void unp_freerights(struct file **, int); 283 static void unp_init(void); 284 static int unp_internalize(struct mbuf **, struct thread *); 285 static void unp_internalize_fp(struct file *); 286 static int unp_externalize(struct mbuf *, struct mbuf **); 287 static int unp_externalize_fp(struct file *); 288 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 289 static void unp_process_defers(void * __unused, int); 290 291 /* 292 * Definitions of protocols supported in the LOCAL domain. 293 */ 294 static struct domain localdomain; 295 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 296 static struct pr_usrreqs uipc_usrreqs_seqpacket; 297 static struct protosw localsw[] = { 298 { 299 .pr_type = SOCK_STREAM, 300 .pr_domain = &localdomain, 301 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 302 .pr_ctloutput = &uipc_ctloutput, 303 .pr_usrreqs = &uipc_usrreqs_stream 304 }, 305 { 306 .pr_type = SOCK_DGRAM, 307 .pr_domain = &localdomain, 308 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 309 .pr_ctloutput = &uipc_ctloutput, 310 .pr_usrreqs = &uipc_usrreqs_dgram 311 }, 312 { 313 .pr_type = SOCK_SEQPACKET, 314 .pr_domain = &localdomain, 315 316 /* 317 * XXXRW: For now, PR_ADDR because soreceive will bump into them 318 * due to our use of sbappendaddr. A new sbappend variants is needed 319 * that supports both atomic record writes and control data. 320 */ 321 .pr_flags = PR_ADDR|PR_ATOMIC|PR_CONNREQUIRED|PR_WANTRCVD| 322 PR_RIGHTS, 323 .pr_ctloutput = &uipc_ctloutput, 324 .pr_usrreqs = &uipc_usrreqs_seqpacket, 325 }, 326 }; 327 328 static struct domain localdomain = { 329 .dom_family = AF_LOCAL, 330 .dom_name = "local", 331 .dom_init = unp_init, 332 .dom_externalize = unp_externalize, 333 .dom_dispose = unp_dispose, 334 .dom_protosw = localsw, 335 .dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])] 336 }; 337 DOMAIN_SET(local); 338 339 static void 340 uipc_abort(struct socket *so) 341 { 342 struct unpcb *unp, *unp2; 343 344 unp = sotounpcb(so); 345 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 346 347 UNP_LINK_WLOCK(); 348 UNP_PCB_LOCK(unp); 349 unp2 = unp->unp_conn; 350 if (unp2 != NULL) { 351 UNP_PCB_LOCK(unp2); 352 unp_drop(unp2, ECONNABORTED); 353 UNP_PCB_UNLOCK(unp2); 354 } 355 UNP_PCB_UNLOCK(unp); 356 UNP_LINK_WUNLOCK(); 357 } 358 359 static int 360 uipc_accept(struct socket *so, struct sockaddr **nam) 361 { 362 struct unpcb *unp, *unp2; 363 const struct sockaddr *sa; 364 365 /* 366 * Pass back name of connected socket, if it was bound and we are 367 * still connected (our peer may have closed already!). 368 */ 369 unp = sotounpcb(so); 370 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 371 372 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 373 UNP_LINK_RLOCK(); 374 unp2 = unp->unp_conn; 375 if (unp2 != NULL && unp2->unp_addr != NULL) { 376 UNP_PCB_LOCK(unp2); 377 sa = (struct sockaddr *) unp2->unp_addr; 378 bcopy(sa, *nam, sa->sa_len); 379 UNP_PCB_UNLOCK(unp2); 380 } else { 381 sa = &sun_noname; 382 bcopy(sa, *nam, sa->sa_len); 383 } 384 UNP_LINK_RUNLOCK(); 385 return (0); 386 } 387 388 static int 389 uipc_attach(struct socket *so, int proto, struct thread *td) 390 { 391 u_long sendspace, recvspace; 392 struct unpcb *unp; 393 int error; 394 395 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 396 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 397 switch (so->so_type) { 398 case SOCK_STREAM: 399 sendspace = unpst_sendspace; 400 recvspace = unpst_recvspace; 401 break; 402 403 case SOCK_DGRAM: 404 sendspace = unpdg_sendspace; 405 recvspace = unpdg_recvspace; 406 break; 407 408 case SOCK_SEQPACKET: 409 sendspace = unpsp_sendspace; 410 recvspace = unpsp_recvspace; 411 break; 412 413 default: 414 panic("uipc_attach"); 415 } 416 error = soreserve(so, sendspace, recvspace); 417 if (error) 418 return (error); 419 } 420 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 421 if (unp == NULL) 422 return (ENOBUFS); 423 LIST_INIT(&unp->unp_refs); 424 UNP_PCB_LOCK_INIT(unp); 425 unp->unp_socket = so; 426 so->so_pcb = unp; 427 unp->unp_refcount = 1; 428 429 UNP_LIST_LOCK(); 430 unp->unp_gencnt = ++unp_gencnt; 431 unp_count++; 432 switch (so->so_type) { 433 case SOCK_STREAM: 434 LIST_INSERT_HEAD(&unp_shead, unp, unp_link); 435 break; 436 437 case SOCK_DGRAM: 438 LIST_INSERT_HEAD(&unp_dhead, unp, unp_link); 439 break; 440 441 case SOCK_SEQPACKET: 442 LIST_INSERT_HEAD(&unp_sphead, unp, unp_link); 443 break; 444 445 default: 446 panic("uipc_attach"); 447 } 448 UNP_LIST_UNLOCK(); 449 450 return (0); 451 } 452 453 static int 454 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 455 { 456 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 457 struct vattr vattr; 458 int error, namelen, vfslocked; 459 struct nameidata nd; 460 struct unpcb *unp; 461 struct vnode *vp; 462 struct mount *mp; 463 char *buf; 464 465 unp = sotounpcb(so); 466 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 467 468 if (soun->sun_len > sizeof(struct sockaddr_un)) 469 return (EINVAL); 470 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 471 if (namelen <= 0) 472 return (EINVAL); 473 474 /* 475 * We don't allow simultaneous bind() calls on a single UNIX domain 476 * socket, so flag in-progress operations, and return an error if an 477 * operation is already in progress. 478 * 479 * Historically, we have not allowed a socket to be rebound, so this 480 * also returns an error. Not allowing re-binding simplifies the 481 * implementation and avoids a great many possible failure modes. 482 */ 483 UNP_PCB_LOCK(unp); 484 if (unp->unp_vnode != NULL) { 485 UNP_PCB_UNLOCK(unp); 486 return (EINVAL); 487 } 488 if (unp->unp_flags & UNP_BINDING) { 489 UNP_PCB_UNLOCK(unp); 490 return (EALREADY); 491 } 492 unp->unp_flags |= UNP_BINDING; 493 UNP_PCB_UNLOCK(unp); 494 495 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 496 bcopy(soun->sun_path, buf, namelen); 497 buf[namelen] = 0; 498 499 restart: 500 vfslocked = 0; 501 NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME, 502 UIO_SYSSPACE, buf, td); 503 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 504 error = namei(&nd); 505 if (error) 506 goto error; 507 vp = nd.ni_vp; 508 vfslocked = NDHASGIANT(&nd); 509 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 510 NDFREE(&nd, NDF_ONLY_PNBUF); 511 if (nd.ni_dvp == vp) 512 vrele(nd.ni_dvp); 513 else 514 vput(nd.ni_dvp); 515 if (vp != NULL) { 516 vrele(vp); 517 error = EADDRINUSE; 518 goto error; 519 } 520 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 521 if (error) 522 goto error; 523 VFS_UNLOCK_GIANT(vfslocked); 524 goto restart; 525 } 526 VATTR_NULL(&vattr); 527 vattr.va_type = VSOCK; 528 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 529 #ifdef MAC 530 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 531 &vattr); 532 #endif 533 if (error == 0) 534 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 535 NDFREE(&nd, NDF_ONLY_PNBUF); 536 vput(nd.ni_dvp); 537 if (error) { 538 vn_finished_write(mp); 539 goto error; 540 } 541 vp = nd.ni_vp; 542 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 543 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 544 545 UNP_LINK_WLOCK(); 546 UNP_PCB_LOCK(unp); 547 VOP_UNP_BIND(vp, unp->unp_socket); 548 unp->unp_vnode = vp; 549 unp->unp_addr = soun; 550 unp->unp_flags &= ~UNP_BINDING; 551 UNP_PCB_UNLOCK(unp); 552 UNP_LINK_WUNLOCK(); 553 VOP_UNLOCK(vp, 0); 554 vn_finished_write(mp); 555 VFS_UNLOCK_GIANT(vfslocked); 556 free(buf, M_TEMP); 557 return (0); 558 559 error: 560 VFS_UNLOCK_GIANT(vfslocked); 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_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 570 { 571 int error; 572 573 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 574 UNP_LINK_WLOCK(); 575 error = unp_connect(so, nam, td); 576 UNP_LINK_WUNLOCK(); 577 return (error); 578 } 579 580 static void 581 uipc_close(struct socket *so) 582 { 583 struct unpcb *unp, *unp2; 584 585 unp = sotounpcb(so); 586 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 587 588 UNP_LINK_WLOCK(); 589 UNP_PCB_LOCK(unp); 590 unp2 = unp->unp_conn; 591 if (unp2 != NULL) { 592 UNP_PCB_LOCK(unp2); 593 unp_disconnect(unp, unp2); 594 UNP_PCB_UNLOCK(unp2); 595 } 596 UNP_PCB_UNLOCK(unp); 597 UNP_LINK_WUNLOCK(); 598 } 599 600 static int 601 uipc_connect2(struct socket *so1, struct socket *so2) 602 { 603 struct unpcb *unp, *unp2; 604 int error; 605 606 UNP_LINK_WLOCK(); 607 unp = so1->so_pcb; 608 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 609 UNP_PCB_LOCK(unp); 610 unp2 = so2->so_pcb; 611 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 612 UNP_PCB_LOCK(unp2); 613 error = unp_connect2(so1, so2, PRU_CONNECT2); 614 UNP_PCB_UNLOCK(unp2); 615 UNP_PCB_UNLOCK(unp); 616 UNP_LINK_WUNLOCK(); 617 return (error); 618 } 619 620 static void 621 uipc_detach(struct socket *so) 622 { 623 struct unpcb *unp, *unp2; 624 struct sockaddr_un *saved_unp_addr; 625 struct vnode *vp; 626 int freeunp, local_unp_rights; 627 628 unp = sotounpcb(so); 629 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 630 631 UNP_LINK_WLOCK(); 632 UNP_LIST_LOCK(); 633 UNP_PCB_LOCK(unp); 634 LIST_REMOVE(unp, unp_link); 635 unp->unp_gencnt = ++unp_gencnt; 636 --unp_count; 637 UNP_LIST_UNLOCK(); 638 639 /* 640 * XXXRW: Should assert vp->v_socket == so. 641 */ 642 if ((vp = unp->unp_vnode) != NULL) { 643 VOP_UNP_DETACH(vp); 644 unp->unp_vnode = NULL; 645 } 646 unp2 = unp->unp_conn; 647 if (unp2 != NULL) { 648 UNP_PCB_LOCK(unp2); 649 unp_disconnect(unp, unp2); 650 UNP_PCB_UNLOCK(unp2); 651 } 652 653 /* 654 * We hold the linkage lock exclusively, so it's OK to acquire 655 * multiple pcb locks at a time. 656 */ 657 while (!LIST_EMPTY(&unp->unp_refs)) { 658 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 659 660 UNP_PCB_LOCK(ref); 661 unp_drop(ref, ECONNRESET); 662 UNP_PCB_UNLOCK(ref); 663 } 664 local_unp_rights = unp_rights; 665 UNP_LINK_WUNLOCK(); 666 unp->unp_socket->so_pcb = NULL; 667 saved_unp_addr = unp->unp_addr; 668 unp->unp_addr = NULL; 669 unp->unp_refcount--; 670 freeunp = (unp->unp_refcount == 0); 671 if (saved_unp_addr != NULL) 672 free(saved_unp_addr, M_SONAME); 673 if (freeunp) { 674 UNP_PCB_LOCK_DESTROY(unp); 675 uma_zfree(unp_zone, unp); 676 } else 677 UNP_PCB_UNLOCK(unp); 678 if (vp) { 679 int vfslocked; 680 681 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 682 vrele(vp); 683 VFS_UNLOCK_GIANT(vfslocked); 684 } 685 if (local_unp_rights) 686 taskqueue_enqueue_timeout(taskqueue_thread, &unp_gc_task, -1); 687 } 688 689 static int 690 uipc_disconnect(struct socket *so) 691 { 692 struct unpcb *unp, *unp2; 693 694 unp = sotounpcb(so); 695 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 696 697 UNP_LINK_WLOCK(); 698 UNP_PCB_LOCK(unp); 699 unp2 = unp->unp_conn; 700 if (unp2 != NULL) { 701 UNP_PCB_LOCK(unp2); 702 unp_disconnect(unp, unp2); 703 UNP_PCB_UNLOCK(unp2); 704 } 705 UNP_PCB_UNLOCK(unp); 706 UNP_LINK_WUNLOCK(); 707 return (0); 708 } 709 710 static int 711 uipc_listen(struct socket *so, int backlog, struct thread *td) 712 { 713 struct unpcb *unp; 714 int error; 715 716 unp = sotounpcb(so); 717 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 718 719 UNP_PCB_LOCK(unp); 720 if (unp->unp_vnode == NULL) { 721 UNP_PCB_UNLOCK(unp); 722 return (EINVAL); 723 } 724 725 SOCK_LOCK(so); 726 error = solisten_proto_check(so); 727 if (error == 0) { 728 cru2x(td->td_ucred, &unp->unp_peercred); 729 unp->unp_flags |= UNP_HAVEPCCACHED; 730 solisten_proto(so, backlog); 731 } 732 SOCK_UNLOCK(so); 733 UNP_PCB_UNLOCK(unp); 734 return (error); 735 } 736 737 static int 738 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 739 { 740 struct unpcb *unp, *unp2; 741 const struct sockaddr *sa; 742 743 unp = sotounpcb(so); 744 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 745 746 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 747 UNP_LINK_RLOCK(); 748 /* 749 * XXX: It seems that this test always fails even when connection is 750 * established. So, this else clause is added as workaround to 751 * return PF_LOCAL sockaddr. 752 */ 753 unp2 = unp->unp_conn; 754 if (unp2 != NULL) { 755 UNP_PCB_LOCK(unp2); 756 if (unp2->unp_addr != NULL) 757 sa = (struct sockaddr *) unp2->unp_addr; 758 else 759 sa = &sun_noname; 760 bcopy(sa, *nam, sa->sa_len); 761 UNP_PCB_UNLOCK(unp2); 762 } else { 763 sa = &sun_noname; 764 bcopy(sa, *nam, sa->sa_len); 765 } 766 UNP_LINK_RUNLOCK(); 767 return (0); 768 } 769 770 static int 771 uipc_rcvd(struct socket *so, int flags) 772 { 773 struct unpcb *unp, *unp2; 774 struct socket *so2; 775 u_int mbcnt, sbcc; 776 u_long newhiwat; 777 778 unp = sotounpcb(so); 779 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL")); 780 781 if (so->so_type != SOCK_STREAM && so->so_type != SOCK_SEQPACKET) 782 panic("uipc_rcvd socktype %d", so->so_type); 783 784 /* 785 * Adjust backpressure on sender and wakeup any waiting to write. 786 * 787 * The unp lock is acquired to maintain the validity of the unp_conn 788 * pointer; no lock on unp2 is required as unp2->unp_socket will be 789 * static as long as we don't permit unp2 to disconnect from unp, 790 * which is prevented by the lock on unp. We cache values from 791 * so_rcv to avoid holding the so_rcv lock over the entire 792 * transaction on the remote so_snd. 793 */ 794 SOCKBUF_LOCK(&so->so_rcv); 795 mbcnt = so->so_rcv.sb_mbcnt; 796 sbcc = so->so_rcv.sb_cc; 797 SOCKBUF_UNLOCK(&so->so_rcv); 798 UNP_PCB_LOCK(unp); 799 unp2 = unp->unp_conn; 800 if (unp2 == NULL) { 801 UNP_PCB_UNLOCK(unp); 802 return (0); 803 } 804 so2 = unp2->unp_socket; 805 SOCKBUF_LOCK(&so2->so_snd); 806 so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt; 807 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc; 808 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, 809 newhiwat, RLIM_INFINITY); 810 sowwakeup_locked(so2); 811 unp->unp_mbcnt = mbcnt; 812 unp->unp_cc = sbcc; 813 UNP_PCB_UNLOCK(unp); 814 return (0); 815 } 816 817 static int 818 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 819 struct mbuf *control, struct thread *td) 820 { 821 struct unpcb *unp, *unp2; 822 struct socket *so2; 823 u_int mbcnt_delta, sbcc; 824 u_int newhiwat; 825 int error = 0; 826 827 unp = sotounpcb(so); 828 KASSERT(unp != NULL, ("uipc_send: unp == NULL")); 829 830 if (flags & PRUS_OOB) { 831 error = EOPNOTSUPP; 832 goto release; 833 } 834 if (control != NULL && (error = unp_internalize(&control, td))) 835 goto release; 836 if ((nam != NULL) || (flags & PRUS_EOF)) 837 UNP_LINK_WLOCK(); 838 else 839 UNP_LINK_RLOCK(); 840 switch (so->so_type) { 841 case SOCK_DGRAM: 842 { 843 const struct sockaddr *from; 844 845 unp2 = unp->unp_conn; 846 if (nam != NULL) { 847 UNP_LINK_WLOCK_ASSERT(); 848 if (unp2 != NULL) { 849 error = EISCONN; 850 break; 851 } 852 error = unp_connect(so, nam, td); 853 if (error) 854 break; 855 unp2 = unp->unp_conn; 856 } 857 858 /* 859 * Because connect() and send() are non-atomic in a sendto() 860 * with a target address, it's possible that the socket will 861 * have disconnected before the send() can run. In that case 862 * return the slightly counter-intuitive but otherwise 863 * correct error that the socket is not connected. 864 */ 865 if (unp2 == NULL) { 866 error = ENOTCONN; 867 break; 868 } 869 /* Lockless read. */ 870 if (unp2->unp_flags & UNP_WANTCRED) 871 control = unp_addsockcred(td, control); 872 UNP_PCB_LOCK(unp); 873 if (unp->unp_addr != NULL) 874 from = (struct sockaddr *)unp->unp_addr; 875 else 876 from = &sun_noname; 877 so2 = unp2->unp_socket; 878 SOCKBUF_LOCK(&so2->so_rcv); 879 if (sbappendaddr_locked(&so2->so_rcv, from, m, 880 control)) { 881 sorwakeup_locked(so2); 882 m = NULL; 883 control = NULL; 884 } else { 885 SOCKBUF_UNLOCK(&so2->so_rcv); 886 error = ENOBUFS; 887 } 888 if (nam != NULL) { 889 UNP_LINK_WLOCK_ASSERT(); 890 UNP_PCB_LOCK(unp2); 891 unp_disconnect(unp, unp2); 892 UNP_PCB_UNLOCK(unp2); 893 } 894 UNP_PCB_UNLOCK(unp); 895 break; 896 } 897 898 case SOCK_SEQPACKET: 899 case SOCK_STREAM: 900 if ((so->so_state & SS_ISCONNECTED) == 0) { 901 if (nam != NULL) { 902 UNP_LINK_WLOCK_ASSERT(); 903 error = unp_connect(so, nam, td); 904 if (error) 905 break; /* XXX */ 906 } else { 907 error = ENOTCONN; 908 break; 909 } 910 } 911 912 /* Lockless read. */ 913 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 914 error = EPIPE; 915 break; 916 } 917 918 /* 919 * Because connect() and send() are non-atomic in a sendto() 920 * with a target address, it's possible that the socket will 921 * have disconnected before the send() can run. In that case 922 * return the slightly counter-intuitive but otherwise 923 * correct error that the socket is not connected. 924 * 925 * Locking here must be done carefully: the linkage lock 926 * prevents interconnections between unpcbs from changing, so 927 * we can traverse from unp to unp2 without acquiring unp's 928 * lock. Socket buffer locks follow unpcb locks, so we can 929 * acquire both remote and lock socket buffer locks. 930 */ 931 unp2 = unp->unp_conn; 932 if (unp2 == NULL) { 933 error = ENOTCONN; 934 break; 935 } 936 so2 = unp2->unp_socket; 937 UNP_PCB_LOCK(unp2); 938 SOCKBUF_LOCK(&so2->so_rcv); 939 if (unp2->unp_flags & UNP_WANTCRED) { 940 /* 941 * Credentials are passed only once on SOCK_STREAM 942 * and SOCK_SEQPACKET. 943 */ 944 unp2->unp_flags &= ~UNP_WANTCRED; 945 control = unp_addsockcred(td, control); 946 } 947 /* 948 * Send to paired receive port, and then reduce send buffer 949 * hiwater marks to maintain backpressure. Wake up readers. 950 */ 951 switch (so->so_type) { 952 case SOCK_STREAM: 953 if (control != NULL) { 954 if (sbappendcontrol_locked(&so2->so_rcv, m, 955 control)) 956 control = NULL; 957 } else 958 sbappend_locked(&so2->so_rcv, m); 959 break; 960 961 case SOCK_SEQPACKET: { 962 const struct sockaddr *from; 963 964 from = &sun_noname; 965 /* 966 * Don't check for space available in so2->so_rcv. 967 * Unix domain sockets only check for space in the 968 * sending sockbuf, and that check is performed one 969 * level up the stack. 970 */ 971 if (sbappendaddr_nospacecheck_locked(&so2->so_rcv, 972 from, m, control)) 973 control = NULL; 974 break; 975 } 976 } 977 978 /* 979 * XXXRW: While fine for SOCK_STREAM, this conflates maximum 980 * datagram size and back-pressure for SOCK_SEQPACKET, which 981 * can lead to undesired return of EMSGSIZE on send instead 982 * of more desirable blocking. 983 */ 984 mbcnt_delta = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt; 985 unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt; 986 sbcc = so2->so_rcv.sb_cc; 987 sorwakeup_locked(so2); 988 989 SOCKBUF_LOCK(&so->so_snd); 990 if ((int)so->so_snd.sb_hiwat >= (int)(sbcc - unp2->unp_cc)) 991 newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc); 992 else 993 newhiwat = 0; 994 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, 995 newhiwat, RLIM_INFINITY); 996 so->so_snd.sb_mbmax -= mbcnt_delta; 997 SOCKBUF_UNLOCK(&so->so_snd); 998 unp2->unp_cc = sbcc; 999 UNP_PCB_UNLOCK(unp2); 1000 m = NULL; 1001 break; 1002 1003 default: 1004 panic("uipc_send unknown socktype"); 1005 } 1006 1007 /* 1008 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 1009 */ 1010 if (flags & PRUS_EOF) { 1011 UNP_PCB_LOCK(unp); 1012 socantsendmore(so); 1013 unp_shutdown(unp); 1014 UNP_PCB_UNLOCK(unp); 1015 } 1016 1017 if ((nam != NULL) || (flags & PRUS_EOF)) 1018 UNP_LINK_WUNLOCK(); 1019 else 1020 UNP_LINK_RUNLOCK(); 1021 1022 if (control != NULL && error != 0) 1023 unp_dispose(control); 1024 1025 release: 1026 if (control != NULL) 1027 m_freem(control); 1028 if (m != NULL) 1029 m_freem(m); 1030 return (error); 1031 } 1032 1033 static int 1034 uipc_sense(struct socket *so, struct stat *sb) 1035 { 1036 struct unpcb *unp, *unp2; 1037 struct socket *so2; 1038 1039 unp = sotounpcb(so); 1040 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 1041 1042 sb->st_blksize = so->so_snd.sb_hiwat; 1043 UNP_LINK_RLOCK(); 1044 UNP_PCB_LOCK(unp); 1045 unp2 = unp->unp_conn; 1046 if ((so->so_type == SOCK_STREAM || so->so_type == SOCK_SEQPACKET) && 1047 unp2 != NULL) { 1048 so2 = unp2->unp_socket; 1049 sb->st_blksize += so2->so_rcv.sb_cc; 1050 } 1051 sb->st_dev = NODEV; 1052 if (unp->unp_ino == 0) 1053 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 1054 sb->st_ino = unp->unp_ino; 1055 UNP_PCB_UNLOCK(unp); 1056 UNP_LINK_RUNLOCK(); 1057 return (0); 1058 } 1059 1060 static int 1061 uipc_shutdown(struct socket *so) 1062 { 1063 struct unpcb *unp; 1064 1065 unp = sotounpcb(so); 1066 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 1067 1068 UNP_LINK_WLOCK(); 1069 UNP_PCB_LOCK(unp); 1070 socantsendmore(so); 1071 unp_shutdown(unp); 1072 UNP_PCB_UNLOCK(unp); 1073 UNP_LINK_WUNLOCK(); 1074 return (0); 1075 } 1076 1077 static int 1078 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1079 { 1080 struct unpcb *unp; 1081 const struct sockaddr *sa; 1082 1083 unp = sotounpcb(so); 1084 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1085 1086 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1087 UNP_PCB_LOCK(unp); 1088 if (unp->unp_addr != NULL) 1089 sa = (struct sockaddr *) unp->unp_addr; 1090 else 1091 sa = &sun_noname; 1092 bcopy(sa, *nam, sa->sa_len); 1093 UNP_PCB_UNLOCK(unp); 1094 return (0); 1095 } 1096 1097 static struct pr_usrreqs uipc_usrreqs_dgram = { 1098 .pru_abort = uipc_abort, 1099 .pru_accept = uipc_accept, 1100 .pru_attach = uipc_attach, 1101 .pru_bind = uipc_bind, 1102 .pru_connect = uipc_connect, 1103 .pru_connect2 = uipc_connect2, 1104 .pru_detach = uipc_detach, 1105 .pru_disconnect = uipc_disconnect, 1106 .pru_listen = uipc_listen, 1107 .pru_peeraddr = uipc_peeraddr, 1108 .pru_rcvd = uipc_rcvd, 1109 .pru_send = uipc_send, 1110 .pru_sense = uipc_sense, 1111 .pru_shutdown = uipc_shutdown, 1112 .pru_sockaddr = uipc_sockaddr, 1113 .pru_soreceive = soreceive_dgram, 1114 .pru_close = uipc_close, 1115 }; 1116 1117 static struct pr_usrreqs uipc_usrreqs_seqpacket = { 1118 .pru_abort = uipc_abort, 1119 .pru_accept = uipc_accept, 1120 .pru_attach = uipc_attach, 1121 .pru_bind = uipc_bind, 1122 .pru_connect = uipc_connect, 1123 .pru_connect2 = uipc_connect2, 1124 .pru_detach = uipc_detach, 1125 .pru_disconnect = uipc_disconnect, 1126 .pru_listen = uipc_listen, 1127 .pru_peeraddr = uipc_peeraddr, 1128 .pru_rcvd = uipc_rcvd, 1129 .pru_send = uipc_send, 1130 .pru_sense = uipc_sense, 1131 .pru_shutdown = uipc_shutdown, 1132 .pru_sockaddr = uipc_sockaddr, 1133 .pru_soreceive = soreceive_generic, /* XXX: or...? */ 1134 .pru_close = uipc_close, 1135 }; 1136 1137 static struct pr_usrreqs uipc_usrreqs_stream = { 1138 .pru_abort = uipc_abort, 1139 .pru_accept = uipc_accept, 1140 .pru_attach = uipc_attach, 1141 .pru_bind = uipc_bind, 1142 .pru_connect = uipc_connect, 1143 .pru_connect2 = uipc_connect2, 1144 .pru_detach = uipc_detach, 1145 .pru_disconnect = uipc_disconnect, 1146 .pru_listen = uipc_listen, 1147 .pru_peeraddr = uipc_peeraddr, 1148 .pru_rcvd = uipc_rcvd, 1149 .pru_send = uipc_send, 1150 .pru_sense = uipc_sense, 1151 .pru_shutdown = uipc_shutdown, 1152 .pru_sockaddr = uipc_sockaddr, 1153 .pru_soreceive = soreceive_generic, 1154 .pru_close = uipc_close, 1155 }; 1156 1157 static int 1158 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1159 { 1160 struct unpcb *unp; 1161 struct xucred xu; 1162 int error, optval; 1163 1164 if (sopt->sopt_level != 0) 1165 return (EINVAL); 1166 1167 unp = sotounpcb(so); 1168 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1169 error = 0; 1170 switch (sopt->sopt_dir) { 1171 case SOPT_GET: 1172 switch (sopt->sopt_name) { 1173 case LOCAL_PEERCRED: 1174 UNP_PCB_LOCK(unp); 1175 if (unp->unp_flags & UNP_HAVEPC) 1176 xu = unp->unp_peercred; 1177 else { 1178 if (so->so_type == SOCK_STREAM) 1179 error = ENOTCONN; 1180 else 1181 error = EINVAL; 1182 } 1183 UNP_PCB_UNLOCK(unp); 1184 if (error == 0) 1185 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1186 break; 1187 1188 case LOCAL_CREDS: 1189 /* Unlocked read. */ 1190 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1191 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1192 break; 1193 1194 case LOCAL_CONNWAIT: 1195 /* Unlocked read. */ 1196 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1197 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1198 break; 1199 1200 default: 1201 error = EOPNOTSUPP; 1202 break; 1203 } 1204 break; 1205 1206 case SOPT_SET: 1207 switch (sopt->sopt_name) { 1208 case LOCAL_CREDS: 1209 case LOCAL_CONNWAIT: 1210 error = sooptcopyin(sopt, &optval, sizeof(optval), 1211 sizeof(optval)); 1212 if (error) 1213 break; 1214 1215 #define OPTSET(bit) do { \ 1216 UNP_PCB_LOCK(unp); \ 1217 if (optval) \ 1218 unp->unp_flags |= bit; \ 1219 else \ 1220 unp->unp_flags &= ~bit; \ 1221 UNP_PCB_UNLOCK(unp); \ 1222 } while (0) 1223 1224 switch (sopt->sopt_name) { 1225 case LOCAL_CREDS: 1226 OPTSET(UNP_WANTCRED); 1227 break; 1228 1229 case LOCAL_CONNWAIT: 1230 OPTSET(UNP_CONNWAIT); 1231 break; 1232 1233 default: 1234 break; 1235 } 1236 break; 1237 #undef OPTSET 1238 default: 1239 error = ENOPROTOOPT; 1240 break; 1241 } 1242 break; 1243 1244 default: 1245 error = EOPNOTSUPP; 1246 break; 1247 } 1248 return (error); 1249 } 1250 1251 static int 1252 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1253 { 1254 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1255 struct vnode *vp; 1256 struct socket *so2, *so3; 1257 struct unpcb *unp, *unp2, *unp3; 1258 int error, len, vfslocked; 1259 struct nameidata nd; 1260 char buf[SOCK_MAXADDRLEN]; 1261 struct sockaddr *sa; 1262 1263 UNP_LINK_WLOCK_ASSERT(); 1264 1265 unp = sotounpcb(so); 1266 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1267 1268 if (nam->sa_len > sizeof(struct sockaddr_un)) 1269 return (EINVAL); 1270 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1271 if (len <= 0) 1272 return (EINVAL); 1273 bcopy(soun->sun_path, buf, len); 1274 buf[len] = 0; 1275 1276 UNP_PCB_LOCK(unp); 1277 if (unp->unp_flags & UNP_CONNECTING) { 1278 UNP_PCB_UNLOCK(unp); 1279 return (EALREADY); 1280 } 1281 UNP_LINK_WUNLOCK(); 1282 unp->unp_flags |= UNP_CONNECTING; 1283 UNP_PCB_UNLOCK(unp); 1284 1285 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1286 NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKSHARED | LOCKLEAF, 1287 UIO_SYSSPACE, buf, td); 1288 error = namei(&nd); 1289 if (error) 1290 vp = NULL; 1291 else 1292 vp = nd.ni_vp; 1293 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1294 vfslocked = NDHASGIANT(&nd); 1295 NDFREE(&nd, NDF_ONLY_PNBUF); 1296 if (error) 1297 goto bad; 1298 1299 if (vp->v_type != VSOCK) { 1300 error = ENOTSOCK; 1301 goto bad; 1302 } 1303 #ifdef MAC 1304 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1305 if (error) 1306 goto bad; 1307 #endif 1308 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1309 if (error) 1310 goto bad; 1311 VFS_UNLOCK_GIANT(vfslocked); 1312 1313 unp = sotounpcb(so); 1314 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1315 1316 /* 1317 * Lock linkage lock for two reasons: make sure v_socket is stable, 1318 * and to protect simultaneous locking of multiple pcbs. 1319 */ 1320 UNP_LINK_WLOCK(); 1321 VOP_UNP_CONNECT(vp, &so2); 1322 if (so2 == NULL) { 1323 error = ECONNREFUSED; 1324 goto bad2; 1325 } 1326 if (so->so_type != so2->so_type) { 1327 error = EPROTOTYPE; 1328 goto bad2; 1329 } 1330 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1331 if (so2->so_options & SO_ACCEPTCONN) { 1332 CURVNET_SET(so2->so_vnet); 1333 so3 = sonewconn(so2, 0); 1334 CURVNET_RESTORE(); 1335 } else 1336 so3 = NULL; 1337 if (so3 == NULL) { 1338 error = ECONNREFUSED; 1339 goto bad2; 1340 } 1341 unp = sotounpcb(so); 1342 unp2 = sotounpcb(so2); 1343 unp3 = sotounpcb(so3); 1344 UNP_PCB_LOCK(unp); 1345 UNP_PCB_LOCK(unp2); 1346 UNP_PCB_LOCK(unp3); 1347 if (unp2->unp_addr != NULL) { 1348 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1349 unp3->unp_addr = (struct sockaddr_un *) sa; 1350 sa = NULL; 1351 } 1352 1353 /* 1354 * The connector's (client's) credentials are copied from its 1355 * process structure at the time of connect() (which is now). 1356 */ 1357 cru2x(td->td_ucred, &unp3->unp_peercred); 1358 unp3->unp_flags |= UNP_HAVEPC; 1359 1360 /* 1361 * The receiver's (server's) credentials are copied from the 1362 * unp_peercred member of socket on which the former called 1363 * listen(); uipc_listen() cached that process's credentials 1364 * at that time so we can use them now. 1365 */ 1366 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1367 ("unp_connect: listener without cached peercred")); 1368 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1369 sizeof(unp->unp_peercred)); 1370 unp->unp_flags |= UNP_HAVEPC; 1371 if (unp2->unp_flags & UNP_WANTCRED) 1372 unp3->unp_flags |= UNP_WANTCRED; 1373 UNP_PCB_UNLOCK(unp3); 1374 UNP_PCB_UNLOCK(unp2); 1375 UNP_PCB_UNLOCK(unp); 1376 #ifdef MAC 1377 mac_socketpeer_set_from_socket(so, so3); 1378 mac_socketpeer_set_from_socket(so3, so); 1379 #endif 1380 1381 so2 = so3; 1382 } 1383 unp = sotounpcb(so); 1384 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1385 unp2 = sotounpcb(so2); 1386 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL")); 1387 UNP_PCB_LOCK(unp); 1388 UNP_PCB_LOCK(unp2); 1389 error = unp_connect2(so, so2, PRU_CONNECT); 1390 UNP_PCB_UNLOCK(unp2); 1391 UNP_PCB_UNLOCK(unp); 1392 bad2: 1393 UNP_LINK_WUNLOCK(); 1394 if (vfslocked) 1395 /* 1396 * Giant has been previously acquired. This means filesystem 1397 * isn't MPSAFE. Do it once again. 1398 */ 1399 mtx_lock(&Giant); 1400 bad: 1401 if (vp != NULL) 1402 vput(vp); 1403 VFS_UNLOCK_GIANT(vfslocked); 1404 free(sa, M_SONAME); 1405 UNP_LINK_WLOCK(); 1406 UNP_PCB_LOCK(unp); 1407 unp->unp_flags &= ~UNP_CONNECTING; 1408 UNP_PCB_UNLOCK(unp); 1409 return (error); 1410 } 1411 1412 static int 1413 unp_connect2(struct socket *so, struct socket *so2, int req) 1414 { 1415 struct unpcb *unp; 1416 struct unpcb *unp2; 1417 1418 unp = sotounpcb(so); 1419 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1420 unp2 = sotounpcb(so2); 1421 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1422 1423 UNP_LINK_WLOCK_ASSERT(); 1424 UNP_PCB_LOCK_ASSERT(unp); 1425 UNP_PCB_LOCK_ASSERT(unp2); 1426 1427 if (so2->so_type != so->so_type) 1428 return (EPROTOTYPE); 1429 unp->unp_conn = unp2; 1430 1431 switch (so->so_type) { 1432 case SOCK_DGRAM: 1433 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1434 soisconnected(so); 1435 break; 1436 1437 case SOCK_STREAM: 1438 case SOCK_SEQPACKET: 1439 unp2->unp_conn = unp; 1440 if (req == PRU_CONNECT && 1441 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1442 soisconnecting(so); 1443 else 1444 soisconnected(so); 1445 soisconnected(so2); 1446 break; 1447 1448 default: 1449 panic("unp_connect2"); 1450 } 1451 return (0); 1452 } 1453 1454 static void 1455 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1456 { 1457 struct socket *so; 1458 1459 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1460 1461 UNP_LINK_WLOCK_ASSERT(); 1462 UNP_PCB_LOCK_ASSERT(unp); 1463 UNP_PCB_LOCK_ASSERT(unp2); 1464 1465 unp->unp_conn = NULL; 1466 switch (unp->unp_socket->so_type) { 1467 case SOCK_DGRAM: 1468 LIST_REMOVE(unp, unp_reflink); 1469 so = unp->unp_socket; 1470 SOCK_LOCK(so); 1471 so->so_state &= ~SS_ISCONNECTED; 1472 SOCK_UNLOCK(so); 1473 break; 1474 1475 case SOCK_STREAM: 1476 case SOCK_SEQPACKET: 1477 soisdisconnected(unp->unp_socket); 1478 unp2->unp_conn = NULL; 1479 soisdisconnected(unp2->unp_socket); 1480 break; 1481 } 1482 } 1483 1484 /* 1485 * unp_pcblist() walks the global list of struct unpcb's to generate a 1486 * pointer list, bumping the refcount on each unpcb. It then copies them out 1487 * sequentially, validating the generation number on each to see if it has 1488 * been detached. All of this is necessary because copyout() may sleep on 1489 * disk I/O. 1490 */ 1491 static int 1492 unp_pcblist(SYSCTL_HANDLER_ARGS) 1493 { 1494 int error, i, n; 1495 int freeunp; 1496 struct unpcb *unp, **unp_list; 1497 unp_gen_t gencnt; 1498 struct xunpgen *xug; 1499 struct unp_head *head; 1500 struct xunpcb *xu; 1501 1502 switch ((intptr_t)arg1) { 1503 case SOCK_STREAM: 1504 head = &unp_shead; 1505 break; 1506 1507 case SOCK_DGRAM: 1508 head = &unp_dhead; 1509 break; 1510 1511 case SOCK_SEQPACKET: 1512 head = &unp_sphead; 1513 break; 1514 1515 default: 1516 panic("unp_pcblist: arg1 %d", (int)(intptr_t)arg1); 1517 } 1518 1519 /* 1520 * The process of preparing the PCB list is too time-consuming and 1521 * resource-intensive to repeat twice on every request. 1522 */ 1523 if (req->oldptr == NULL) { 1524 n = unp_count; 1525 req->oldidx = 2 * (sizeof *xug) 1526 + (n + n/8) * sizeof(struct xunpcb); 1527 return (0); 1528 } 1529 1530 if (req->newptr != NULL) 1531 return (EPERM); 1532 1533 /* 1534 * OK, now we're committed to doing something. 1535 */ 1536 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1537 UNP_LIST_LOCK(); 1538 gencnt = unp_gencnt; 1539 n = unp_count; 1540 UNP_LIST_UNLOCK(); 1541 1542 xug->xug_len = sizeof *xug; 1543 xug->xug_count = n; 1544 xug->xug_gen = gencnt; 1545 xug->xug_sogen = so_gencnt; 1546 error = SYSCTL_OUT(req, xug, sizeof *xug); 1547 if (error) { 1548 free(xug, M_TEMP); 1549 return (error); 1550 } 1551 1552 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1553 1554 UNP_LIST_LOCK(); 1555 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1556 unp = LIST_NEXT(unp, unp_link)) { 1557 UNP_PCB_LOCK(unp); 1558 if (unp->unp_gencnt <= gencnt) { 1559 if (cr_cansee(req->td->td_ucred, 1560 unp->unp_socket->so_cred)) { 1561 UNP_PCB_UNLOCK(unp); 1562 continue; 1563 } 1564 unp_list[i++] = unp; 1565 unp->unp_refcount++; 1566 } 1567 UNP_PCB_UNLOCK(unp); 1568 } 1569 UNP_LIST_UNLOCK(); 1570 n = i; /* In case we lost some during malloc. */ 1571 1572 error = 0; 1573 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1574 for (i = 0; i < n; i++) { 1575 unp = unp_list[i]; 1576 UNP_PCB_LOCK(unp); 1577 unp->unp_refcount--; 1578 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) { 1579 xu->xu_len = sizeof *xu; 1580 xu->xu_unpp = unp; 1581 /* 1582 * XXX - need more locking here to protect against 1583 * connect/disconnect races for SMP. 1584 */ 1585 if (unp->unp_addr != NULL) 1586 bcopy(unp->unp_addr, &xu->xu_addr, 1587 unp->unp_addr->sun_len); 1588 if (unp->unp_conn != NULL && 1589 unp->unp_conn->unp_addr != NULL) 1590 bcopy(unp->unp_conn->unp_addr, 1591 &xu->xu_caddr, 1592 unp->unp_conn->unp_addr->sun_len); 1593 bcopy(unp, &xu->xu_unp, sizeof *unp); 1594 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1595 UNP_PCB_UNLOCK(unp); 1596 error = SYSCTL_OUT(req, xu, sizeof *xu); 1597 } else { 1598 freeunp = (unp->unp_refcount == 0); 1599 UNP_PCB_UNLOCK(unp); 1600 if (freeunp) { 1601 UNP_PCB_LOCK_DESTROY(unp); 1602 uma_zfree(unp_zone, unp); 1603 } 1604 } 1605 } 1606 free(xu, M_TEMP); 1607 if (!error) { 1608 /* 1609 * Give the user an updated idea of our state. If the 1610 * generation differs from what we told her before, she knows 1611 * that something happened while we were processing this 1612 * request, and it might be necessary to retry. 1613 */ 1614 xug->xug_gen = unp_gencnt; 1615 xug->xug_sogen = so_gencnt; 1616 xug->xug_count = unp_count; 1617 error = SYSCTL_OUT(req, xug, sizeof *xug); 1618 } 1619 free(unp_list, M_TEMP); 1620 free(xug, M_TEMP); 1621 return (error); 1622 } 1623 1624 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1625 (void *)(intptr_t)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1626 "List of active local datagram sockets"); 1627 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLTYPE_OPAQUE | CTLFLAG_RD, 1628 (void *)(intptr_t)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1629 "List of active local stream sockets"); 1630 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, 1631 CTLTYPE_OPAQUE | CTLFLAG_RD, 1632 (void *)(intptr_t)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1633 "List of active local seqpacket sockets"); 1634 1635 static void 1636 unp_shutdown(struct unpcb *unp) 1637 { 1638 struct unpcb *unp2; 1639 struct socket *so; 1640 1641 UNP_LINK_WLOCK_ASSERT(); 1642 UNP_PCB_LOCK_ASSERT(unp); 1643 1644 unp2 = unp->unp_conn; 1645 if ((unp->unp_socket->so_type == SOCK_STREAM || 1646 (unp->unp_socket->so_type == SOCK_SEQPACKET)) && unp2 != NULL) { 1647 so = unp2->unp_socket; 1648 if (so != NULL) 1649 socantrcvmore(so); 1650 } 1651 } 1652 1653 static void 1654 unp_drop(struct unpcb *unp, int errno) 1655 { 1656 struct socket *so = unp->unp_socket; 1657 struct unpcb *unp2; 1658 1659 UNP_LINK_WLOCK_ASSERT(); 1660 UNP_PCB_LOCK_ASSERT(unp); 1661 1662 so->so_error = errno; 1663 unp2 = unp->unp_conn; 1664 if (unp2 == NULL) 1665 return; 1666 UNP_PCB_LOCK(unp2); 1667 unp_disconnect(unp, unp2); 1668 UNP_PCB_UNLOCK(unp2); 1669 } 1670 1671 static void 1672 unp_freerights(struct file **rp, int fdcount) 1673 { 1674 int i; 1675 struct file *fp; 1676 1677 for (i = 0; i < fdcount; i++) { 1678 fp = *rp; 1679 *rp++ = NULL; 1680 unp_discard(fp); 1681 } 1682 } 1683 1684 static int 1685 unp_externalize(struct mbuf *control, struct mbuf **controlp) 1686 { 1687 struct thread *td = curthread; /* XXX */ 1688 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1689 int i; 1690 int *fdp; 1691 struct file **rp; 1692 struct file *fp; 1693 void *data; 1694 socklen_t clen = control->m_len, datalen; 1695 int error, newfds; 1696 u_int newlen; 1697 1698 UNP_LINK_UNLOCK_ASSERT(); 1699 1700 error = 0; 1701 if (controlp != NULL) /* controlp == NULL => free control messages */ 1702 *controlp = NULL; 1703 while (cm != NULL) { 1704 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1705 error = EINVAL; 1706 break; 1707 } 1708 data = CMSG_DATA(cm); 1709 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1710 if (cm->cmsg_level == SOL_SOCKET 1711 && cm->cmsg_type == SCM_RIGHTS) { 1712 newfds = datalen / sizeof(struct file *); 1713 rp = data; 1714 1715 /* If we're not outputting the descriptors free them. */ 1716 if (error || controlp == NULL) { 1717 unp_freerights(rp, newfds); 1718 goto next; 1719 } 1720 FILEDESC_XLOCK(td->td_proc->p_fd); 1721 /* 1722 * Now change each pointer to an fd in the global 1723 * table to an integer that is the index to the local 1724 * fd table entry that we set up to point to the 1725 * global one we are transferring. 1726 */ 1727 newlen = newfds * sizeof(int); 1728 *controlp = sbcreatecontrol(NULL, newlen, 1729 SCM_RIGHTS, SOL_SOCKET); 1730 if (*controlp == NULL) { 1731 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1732 error = E2BIG; 1733 unp_freerights(rp, newfds); 1734 goto next; 1735 } 1736 1737 fdp = (int *) 1738 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1739 if (fdallocn(td, 0, fdp, newfds) != 0) { 1740 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1741 error = EMSGSIZE; 1742 unp_freerights(rp, newfds); 1743 m_freem(*controlp); 1744 *controlp = NULL; 1745 goto next; 1746 } 1747 for (i = 0; i < newfds; i++) { 1748 fp = *rp++; 1749 td->td_proc->p_fd->fd_ofiles[fdp[i]] = fp; 1750 unp_externalize_fp(fp); 1751 } 1752 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1753 } else { 1754 /* We can just copy anything else across. */ 1755 if (error || controlp == NULL) 1756 goto next; 1757 *controlp = sbcreatecontrol(NULL, datalen, 1758 cm->cmsg_type, cm->cmsg_level); 1759 if (*controlp == NULL) { 1760 error = ENOBUFS; 1761 goto next; 1762 } 1763 bcopy(data, 1764 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1765 datalen); 1766 } 1767 controlp = &(*controlp)->m_next; 1768 1769 next: 1770 if (CMSG_SPACE(datalen) < clen) { 1771 clen -= CMSG_SPACE(datalen); 1772 cm = (struct cmsghdr *) 1773 ((caddr_t)cm + CMSG_SPACE(datalen)); 1774 } else { 1775 clen = 0; 1776 cm = NULL; 1777 } 1778 } 1779 1780 m_freem(control); 1781 return (error); 1782 } 1783 1784 static void 1785 unp_zone_change(void *tag) 1786 { 1787 1788 uma_zone_set_max(unp_zone, maxsockets); 1789 } 1790 1791 static void 1792 unp_init(void) 1793 { 1794 1795 #ifdef VIMAGE 1796 if (!IS_DEFAULT_VNET(curvnet)) 1797 return; 1798 #endif 1799 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1800 NULL, NULL, UMA_ALIGN_PTR, 0); 1801 if (unp_zone == NULL) 1802 panic("unp_init"); 1803 uma_zone_set_max(unp_zone, maxsockets); 1804 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 1805 NULL, EVENTHANDLER_PRI_ANY); 1806 LIST_INIT(&unp_dhead); 1807 LIST_INIT(&unp_shead); 1808 LIST_INIT(&unp_sphead); 1809 SLIST_INIT(&unp_defers); 1810 TIMEOUT_TASK_INIT(taskqueue_thread, &unp_gc_task, 0, unp_gc, NULL); 1811 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 1812 UNP_LINK_LOCK_INIT(); 1813 UNP_LIST_LOCK_INIT(); 1814 UNP_DEFERRED_LOCK_INIT(); 1815 } 1816 1817 static int 1818 unp_internalize(struct mbuf **controlp, struct thread *td) 1819 { 1820 struct mbuf *control = *controlp; 1821 struct proc *p = td->td_proc; 1822 struct filedesc *fdescp = p->p_fd; 1823 struct bintime *bt; 1824 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1825 struct cmsgcred *cmcred; 1826 struct file **rp; 1827 struct file *fp; 1828 struct timeval *tv; 1829 int i, fd, *fdp; 1830 void *data; 1831 socklen_t clen = control->m_len, datalen; 1832 int error, oldfds; 1833 u_int newlen; 1834 1835 UNP_LINK_UNLOCK_ASSERT(); 1836 1837 error = 0; 1838 *controlp = NULL; 1839 while (cm != NULL) { 1840 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1841 || cm->cmsg_len > clen) { 1842 error = EINVAL; 1843 goto out; 1844 } 1845 data = CMSG_DATA(cm); 1846 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1847 1848 switch (cm->cmsg_type) { 1849 /* 1850 * Fill in credential information. 1851 */ 1852 case SCM_CREDS: 1853 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1854 SCM_CREDS, SOL_SOCKET); 1855 if (*controlp == NULL) { 1856 error = ENOBUFS; 1857 goto out; 1858 } 1859 cmcred = (struct cmsgcred *) 1860 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1861 cmcred->cmcred_pid = p->p_pid; 1862 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1863 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1864 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1865 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1866 CMGROUP_MAX); 1867 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1868 cmcred->cmcred_groups[i] = 1869 td->td_ucred->cr_groups[i]; 1870 break; 1871 1872 case SCM_RIGHTS: 1873 oldfds = datalen / sizeof (int); 1874 /* 1875 * Check that all the FDs passed in refer to legal 1876 * files. If not, reject the entire operation. 1877 */ 1878 fdp = data; 1879 FILEDESC_SLOCK(fdescp); 1880 for (i = 0; i < oldfds; i++) { 1881 fd = *fdp++; 1882 if ((unsigned)fd >= fdescp->fd_nfiles || 1883 fdescp->fd_ofiles[fd] == NULL) { 1884 FILEDESC_SUNLOCK(fdescp); 1885 error = EBADF; 1886 goto out; 1887 } 1888 fp = fdescp->fd_ofiles[fd]; 1889 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1890 FILEDESC_SUNLOCK(fdescp); 1891 error = EOPNOTSUPP; 1892 goto out; 1893 } 1894 1895 } 1896 1897 /* 1898 * Now replace the integer FDs with pointers to the 1899 * associated global file table entry.. 1900 */ 1901 newlen = oldfds * sizeof(struct file *); 1902 *controlp = sbcreatecontrol(NULL, newlen, 1903 SCM_RIGHTS, SOL_SOCKET); 1904 if (*controlp == NULL) { 1905 FILEDESC_SUNLOCK(fdescp); 1906 error = E2BIG; 1907 goto out; 1908 } 1909 fdp = data; 1910 rp = (struct file **) 1911 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1912 for (i = 0; i < oldfds; i++) { 1913 fp = fdescp->fd_ofiles[*fdp++]; 1914 *rp++ = fp; 1915 unp_internalize_fp(fp); 1916 } 1917 FILEDESC_SUNLOCK(fdescp); 1918 break; 1919 1920 case SCM_TIMESTAMP: 1921 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1922 SCM_TIMESTAMP, SOL_SOCKET); 1923 if (*controlp == NULL) { 1924 error = ENOBUFS; 1925 goto out; 1926 } 1927 tv = (struct timeval *) 1928 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1929 microtime(tv); 1930 break; 1931 1932 case SCM_BINTIME: 1933 *controlp = sbcreatecontrol(NULL, sizeof(*bt), 1934 SCM_BINTIME, SOL_SOCKET); 1935 if (*controlp == NULL) { 1936 error = ENOBUFS; 1937 goto out; 1938 } 1939 bt = (struct bintime *) 1940 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1941 bintime(bt); 1942 break; 1943 1944 default: 1945 error = EINVAL; 1946 goto out; 1947 } 1948 1949 controlp = &(*controlp)->m_next; 1950 if (CMSG_SPACE(datalen) < clen) { 1951 clen -= CMSG_SPACE(datalen); 1952 cm = (struct cmsghdr *) 1953 ((caddr_t)cm + CMSG_SPACE(datalen)); 1954 } else { 1955 clen = 0; 1956 cm = NULL; 1957 } 1958 } 1959 1960 out: 1961 m_freem(control); 1962 return (error); 1963 } 1964 1965 static struct mbuf * 1966 unp_addsockcred(struct thread *td, struct mbuf *control) 1967 { 1968 struct mbuf *m, *n, *n_prev; 1969 struct sockcred *sc; 1970 const struct cmsghdr *cm; 1971 int ngroups; 1972 int i; 1973 1974 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 1975 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 1976 if (m == NULL) 1977 return (control); 1978 1979 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 1980 sc->sc_uid = td->td_ucred->cr_ruid; 1981 sc->sc_euid = td->td_ucred->cr_uid; 1982 sc->sc_gid = td->td_ucred->cr_rgid; 1983 sc->sc_egid = td->td_ucred->cr_gid; 1984 sc->sc_ngroups = ngroups; 1985 for (i = 0; i < sc->sc_ngroups; i++) 1986 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 1987 1988 /* 1989 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 1990 * created SCM_CREDS control message (struct sockcred) has another 1991 * format. 1992 */ 1993 if (control != NULL) 1994 for (n = control, n_prev = NULL; n != NULL;) { 1995 cm = mtod(n, struct cmsghdr *); 1996 if (cm->cmsg_level == SOL_SOCKET && 1997 cm->cmsg_type == SCM_CREDS) { 1998 if (n_prev == NULL) 1999 control = n->m_next; 2000 else 2001 n_prev->m_next = n->m_next; 2002 n = m_free(n); 2003 } else { 2004 n_prev = n; 2005 n = n->m_next; 2006 } 2007 } 2008 2009 /* Prepend it to the head. */ 2010 m->m_next = control; 2011 return (m); 2012 } 2013 2014 static struct unpcb * 2015 fptounp(struct file *fp) 2016 { 2017 struct socket *so; 2018 2019 if (fp->f_type != DTYPE_SOCKET) 2020 return (NULL); 2021 if ((so = fp->f_data) == NULL) 2022 return (NULL); 2023 if (so->so_proto->pr_domain != &localdomain) 2024 return (NULL); 2025 return sotounpcb(so); 2026 } 2027 2028 static void 2029 unp_discard(struct file *fp) 2030 { 2031 struct unp_defer *dr; 2032 2033 if (unp_externalize_fp(fp)) { 2034 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 2035 dr->ud_fp = fp; 2036 UNP_DEFERRED_LOCK(); 2037 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 2038 UNP_DEFERRED_UNLOCK(); 2039 atomic_add_int(&unp_defers_count, 1); 2040 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 2041 } else 2042 (void) closef(fp, (struct thread *)NULL); 2043 } 2044 2045 static void 2046 unp_process_defers(void *arg __unused, int pending) 2047 { 2048 struct unp_defer *dr; 2049 SLIST_HEAD(, unp_defer) drl; 2050 int count; 2051 2052 SLIST_INIT(&drl); 2053 for (;;) { 2054 UNP_DEFERRED_LOCK(); 2055 if (SLIST_FIRST(&unp_defers) == NULL) { 2056 UNP_DEFERRED_UNLOCK(); 2057 break; 2058 } 2059 SLIST_SWAP(&unp_defers, &drl, unp_defer); 2060 UNP_DEFERRED_UNLOCK(); 2061 count = 0; 2062 while ((dr = SLIST_FIRST(&drl)) != NULL) { 2063 SLIST_REMOVE_HEAD(&drl, ud_link); 2064 closef(dr->ud_fp, NULL); 2065 free(dr, M_TEMP); 2066 count++; 2067 } 2068 atomic_add_int(&unp_defers_count, -count); 2069 } 2070 } 2071 2072 static void 2073 unp_internalize_fp(struct file *fp) 2074 { 2075 struct unpcb *unp; 2076 2077 UNP_LINK_WLOCK(); 2078 if ((unp = fptounp(fp)) != NULL) { 2079 unp->unp_file = fp; 2080 unp->unp_msgcount++; 2081 } 2082 fhold(fp); 2083 unp_rights++; 2084 UNP_LINK_WUNLOCK(); 2085 } 2086 2087 static int 2088 unp_externalize_fp(struct file *fp) 2089 { 2090 struct unpcb *unp; 2091 int ret; 2092 2093 UNP_LINK_WLOCK(); 2094 if ((unp = fptounp(fp)) != NULL) { 2095 unp->unp_msgcount--; 2096 ret = 1; 2097 } else 2098 ret = 0; 2099 unp_rights--; 2100 UNP_LINK_WUNLOCK(); 2101 return (ret); 2102 } 2103 2104 /* 2105 * unp_defer indicates whether additional work has been defered for a future 2106 * pass through unp_gc(). It is thread local and does not require explicit 2107 * synchronization. 2108 */ 2109 static int unp_marked; 2110 static int unp_unreachable; 2111 2112 static void 2113 unp_accessable(struct file *fp) 2114 { 2115 struct unpcb *unp; 2116 2117 if ((unp = fptounp(fp)) == NULL) 2118 return; 2119 if (unp->unp_gcflag & UNPGC_REF) 2120 return; 2121 unp->unp_gcflag &= ~UNPGC_DEAD; 2122 unp->unp_gcflag |= UNPGC_REF; 2123 unp_marked++; 2124 } 2125 2126 static void 2127 unp_gc_process(struct unpcb *unp) 2128 { 2129 struct socket *soa; 2130 struct socket *so; 2131 struct file *fp; 2132 2133 /* Already processed. */ 2134 if (unp->unp_gcflag & UNPGC_SCANNED) 2135 return; 2136 fp = unp->unp_file; 2137 2138 /* 2139 * Check for a socket potentially in a cycle. It must be in a 2140 * queue as indicated by msgcount, and this must equal the file 2141 * reference count. Note that when msgcount is 0 the file is NULL. 2142 */ 2143 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2144 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2145 unp->unp_gcflag |= UNPGC_DEAD; 2146 unp_unreachable++; 2147 return; 2148 } 2149 2150 /* 2151 * Mark all sockets we reference with RIGHTS. 2152 */ 2153 so = unp->unp_socket; 2154 SOCKBUF_LOCK(&so->so_rcv); 2155 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2156 SOCKBUF_UNLOCK(&so->so_rcv); 2157 2158 /* 2159 * Mark all sockets in our accept queue. 2160 */ 2161 ACCEPT_LOCK(); 2162 TAILQ_FOREACH(soa, &so->so_comp, so_list) { 2163 SOCKBUF_LOCK(&soa->so_rcv); 2164 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2165 SOCKBUF_UNLOCK(&soa->so_rcv); 2166 } 2167 ACCEPT_UNLOCK(); 2168 unp->unp_gcflag |= UNPGC_SCANNED; 2169 } 2170 2171 static int unp_recycled; 2172 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2173 "Number of unreachable sockets claimed by the garbage collector."); 2174 2175 static int unp_taskcount; 2176 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2177 "Number of times the garbage collector has run."); 2178 2179 static void 2180 unp_gc(__unused void *arg, int pending) 2181 { 2182 struct unp_head *heads[] = { &unp_dhead, &unp_shead, &unp_sphead, 2183 NULL }; 2184 struct unp_head **head; 2185 struct file *f, **unref; 2186 struct unpcb *unp; 2187 int i, total; 2188 2189 unp_taskcount++; 2190 UNP_LIST_LOCK(); 2191 /* 2192 * First clear all gc flags from previous runs. 2193 */ 2194 for (head = heads; *head != NULL; head++) 2195 LIST_FOREACH(unp, *head, unp_link) 2196 unp->unp_gcflag = 0; 2197 2198 /* 2199 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2200 * is reachable all of the sockets it references are reachable. 2201 * Stop the scan once we do a complete loop without discovering 2202 * a new reachable socket. 2203 */ 2204 do { 2205 unp_unreachable = 0; 2206 unp_marked = 0; 2207 for (head = heads; *head != NULL; head++) 2208 LIST_FOREACH(unp, *head, unp_link) 2209 unp_gc_process(unp); 2210 } while (unp_marked); 2211 UNP_LIST_UNLOCK(); 2212 if (unp_unreachable == 0) 2213 return; 2214 2215 /* 2216 * Allocate space for a local list of dead unpcbs. 2217 */ 2218 unref = malloc(unp_unreachable * sizeof(struct file *), 2219 M_TEMP, M_WAITOK); 2220 2221 /* 2222 * Iterate looking for sockets which have been specifically marked 2223 * as as unreachable and store them locally. 2224 */ 2225 UNP_LINK_RLOCK(); 2226 UNP_LIST_LOCK(); 2227 for (total = 0, head = heads; *head != NULL; head++) 2228 LIST_FOREACH(unp, *head, unp_link) 2229 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2230 f = unp->unp_file; 2231 if (unp->unp_msgcount == 0 || f == NULL || 2232 f->f_count != unp->unp_msgcount) 2233 continue; 2234 unref[total++] = f; 2235 fhold(f); 2236 KASSERT(total <= unp_unreachable, 2237 ("unp_gc: incorrect unreachable count.")); 2238 } 2239 UNP_LIST_UNLOCK(); 2240 UNP_LINK_RUNLOCK(); 2241 2242 /* 2243 * Now flush all sockets, free'ing rights. This will free the 2244 * struct files associated with these sockets but leave each socket 2245 * with one remaining ref. 2246 */ 2247 for (i = 0; i < total; i++) { 2248 struct socket *so; 2249 2250 so = unref[i]->f_data; 2251 CURVNET_SET(so->so_vnet); 2252 sorflush(so); 2253 CURVNET_RESTORE(); 2254 } 2255 2256 /* 2257 * And finally release the sockets so they can be reclaimed. 2258 */ 2259 for (i = 0; i < total; i++) 2260 fdrop(unref[i], NULL); 2261 unp_recycled += total; 2262 free(unref, M_TEMP); 2263 } 2264 2265 static void 2266 unp_dispose(struct mbuf *m) 2267 { 2268 2269 if (m) 2270 unp_scan(m, unp_discard); 2271 } 2272 2273 static void 2274 unp_scan(struct mbuf *m0, void (*op)(struct file *)) 2275 { 2276 struct mbuf *m; 2277 struct file **rp; 2278 struct cmsghdr *cm; 2279 void *data; 2280 int i; 2281 socklen_t clen, datalen; 2282 int qfds; 2283 2284 while (m0 != NULL) { 2285 for (m = m0; m; m = m->m_next) { 2286 if (m->m_type != MT_CONTROL) 2287 continue; 2288 2289 cm = mtod(m, struct cmsghdr *); 2290 clen = m->m_len; 2291 2292 while (cm != NULL) { 2293 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2294 break; 2295 2296 data = CMSG_DATA(cm); 2297 datalen = (caddr_t)cm + cm->cmsg_len 2298 - (caddr_t)data; 2299 2300 if (cm->cmsg_level == SOL_SOCKET && 2301 cm->cmsg_type == SCM_RIGHTS) { 2302 qfds = datalen / sizeof (struct file *); 2303 rp = data; 2304 for (i = 0; i < qfds; i++) 2305 (*op)(*rp++); 2306 } 2307 2308 if (CMSG_SPACE(datalen) < clen) { 2309 clen -= CMSG_SPACE(datalen); 2310 cm = (struct cmsghdr *) 2311 ((caddr_t)cm + CMSG_SPACE(datalen)); 2312 } else { 2313 clen = 0; 2314 cm = NULL; 2315 } 2316 } 2317 } 2318 m0 = m0->m_act; 2319 } 2320 } 2321 2322 /* 2323 * A helper function called by VFS before socket-type vnode reclamation. 2324 * For an active vnode it clears unp_vnode pointer and decrements unp_vnode 2325 * use count. 2326 */ 2327 void 2328 vfs_unp_reclaim(struct vnode *vp) 2329 { 2330 struct socket *so; 2331 struct unpcb *unp; 2332 int active; 2333 2334 ASSERT_VOP_ELOCKED(vp, "vfs_unp_reclaim"); 2335 KASSERT(vp->v_type == VSOCK, 2336 ("vfs_unp_reclaim: vp->v_type != VSOCK")); 2337 2338 active = 0; 2339 UNP_LINK_WLOCK(); 2340 VOP_UNP_CONNECT(vp, &so); 2341 if (so == NULL) 2342 goto done; 2343 unp = sotounpcb(so); 2344 if (unp == NULL) 2345 goto done; 2346 UNP_PCB_LOCK(unp); 2347 if (unp->unp_vnode == vp) { 2348 VOP_UNP_DETACH(vp); 2349 unp->unp_vnode = NULL; 2350 active = 1; 2351 } 2352 UNP_PCB_UNLOCK(unp); 2353 done: 2354 UNP_LINK_WUNLOCK(); 2355 if (active) 2356 vunref(vp); 2357 } 2358 2359 #ifdef DDB 2360 static void 2361 db_print_indent(int indent) 2362 { 2363 int i; 2364 2365 for (i = 0; i < indent; i++) 2366 db_printf(" "); 2367 } 2368 2369 static void 2370 db_print_unpflags(int unp_flags) 2371 { 2372 int comma; 2373 2374 comma = 0; 2375 if (unp_flags & UNP_HAVEPC) { 2376 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2377 comma = 1; 2378 } 2379 if (unp_flags & UNP_HAVEPCCACHED) { 2380 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : ""); 2381 comma = 1; 2382 } 2383 if (unp_flags & UNP_WANTCRED) { 2384 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2385 comma = 1; 2386 } 2387 if (unp_flags & UNP_CONNWAIT) { 2388 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2389 comma = 1; 2390 } 2391 if (unp_flags & UNP_CONNECTING) { 2392 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2393 comma = 1; 2394 } 2395 if (unp_flags & UNP_BINDING) { 2396 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2397 comma = 1; 2398 } 2399 } 2400 2401 static void 2402 db_print_xucred(int indent, struct xucred *xu) 2403 { 2404 int comma, i; 2405 2406 db_print_indent(indent); 2407 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2408 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2409 db_print_indent(indent); 2410 db_printf("cr_groups: "); 2411 comma = 0; 2412 for (i = 0; i < xu->cr_ngroups; i++) { 2413 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2414 comma = 1; 2415 } 2416 db_printf("\n"); 2417 } 2418 2419 static void 2420 db_print_unprefs(int indent, struct unp_head *uh) 2421 { 2422 struct unpcb *unp; 2423 int counter; 2424 2425 counter = 0; 2426 LIST_FOREACH(unp, uh, unp_reflink) { 2427 if (counter % 4 == 0) 2428 db_print_indent(indent); 2429 db_printf("%p ", unp); 2430 if (counter % 4 == 3) 2431 db_printf("\n"); 2432 counter++; 2433 } 2434 if (counter != 0 && counter % 4 != 0) 2435 db_printf("\n"); 2436 } 2437 2438 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2439 { 2440 struct unpcb *unp; 2441 2442 if (!have_addr) { 2443 db_printf("usage: show unpcb <addr>\n"); 2444 return; 2445 } 2446 unp = (struct unpcb *)addr; 2447 2448 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2449 unp->unp_vnode); 2450 2451 db_printf("unp_ino: %d unp_conn: %p\n", unp->unp_ino, 2452 unp->unp_conn); 2453 2454 db_printf("unp_refs:\n"); 2455 db_print_unprefs(2, &unp->unp_refs); 2456 2457 /* XXXRW: Would be nice to print the full address, if any. */ 2458 db_printf("unp_addr: %p\n", unp->unp_addr); 2459 2460 db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n", 2461 unp->unp_cc, unp->unp_mbcnt, 2462 (unsigned long long)unp->unp_gencnt); 2463 2464 db_printf("unp_flags: %x (", unp->unp_flags); 2465 db_print_unpflags(unp->unp_flags); 2466 db_printf(")\n"); 2467 2468 db_printf("unp_peercred:\n"); 2469 db_print_xucred(2, &unp->unp_peercred); 2470 2471 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2472 } 2473 #endif
Cache object: db4e5f4cedfc085f26fc9516060118a0
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