Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
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 * SEQPACKET, RDM 54 * rethink name space problems 55 * need a proper out-of-band 56 */ 57 58 #include <sys/cdefs.h> 59 __FBSDID("$FreeBSD: releng/8.1/sys/kern/uipc_usrreq.c 225827 2011-09-28 08:47:17Z bz $"); 60 61 #include "opt_ddb.h" 62 63 #include <sys/param.h> 64 #include <sys/domain.h> 65 #include <sys/fcntl.h> 66 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 67 #include <sys/eventhandler.h> 68 #include <sys/file.h> 69 #include <sys/filedesc.h> 70 #include <sys/kernel.h> 71 #include <sys/lock.h> 72 #include <sys/mbuf.h> 73 #include <sys/mount.h> 74 #include <sys/mutex.h> 75 #include <sys/namei.h> 76 #include <sys/proc.h> 77 #include <sys/protosw.h> 78 #include <sys/resourcevar.h> 79 #include <sys/rwlock.h> 80 #include <sys/socket.h> 81 #include <sys/socketvar.h> 82 #include <sys/signalvar.h> 83 #include <sys/stat.h> 84 #include <sys/sx.h> 85 #include <sys/sysctl.h> 86 #include <sys/systm.h> 87 #include <sys/taskqueue.h> 88 #include <sys/un.h> 89 #include <sys/unpcb.h> 90 #include <sys/vnode.h> 91 92 #include <net/vnet.h> 93 94 #ifdef DDB 95 #include <ddb/ddb.h> 96 #endif 97 98 #include <security/mac/mac_framework.h> 99 100 #include <vm/uma.h> 101 102 /* 103 * Locking key: 104 * (l) Locked using list lock 105 * (g) Locked using linkage lock 106 */ 107 108 static uma_zone_t unp_zone; 109 static unp_gen_t unp_gencnt; /* (l) */ 110 static u_int unp_count; /* (l) Count of local sockets. */ 111 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 112 static int unp_rights; /* (g) File descriptors in flight. */ 113 static struct unp_head unp_shead; /* (l) List of stream sockets. */ 114 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 115 116 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 117 118 /* 119 * Garbage collection of cyclic file descriptor/socket references occurs 120 * asynchronously in a taskqueue context in order to avoid recursion and 121 * reentrance in the UNIX domain socket, file descriptor, and socket layer 122 * code. See unp_gc() for a full description. 123 */ 124 static struct task unp_gc_task; 125 126 /* 127 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 128 * stream sockets, although the total for sender and receiver is actually 129 * only PIPSIZ. 130 * 131 * Datagram sockets really use the sendspace as the maximum datagram size, 132 * and don't really want to reserve the sendspace. Their recvspace should be 133 * large enough for at least one max-size datagram plus address. 134 */ 135 #ifndef PIPSIZ 136 #define PIPSIZ 8192 137 #endif 138 static u_long unpst_sendspace = PIPSIZ; 139 static u_long unpst_recvspace = PIPSIZ; 140 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 141 static u_long unpdg_recvspace = 4*1024; 142 143 SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain"); 144 SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, "SOCK_STREAM"); 145 SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM"); 146 147 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 148 &unpst_sendspace, 0, "Default stream send space."); 149 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 150 &unpst_recvspace, 0, "Default stream receive space."); 151 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 152 &unpdg_sendspace, 0, "Default datagram send space."); 153 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 154 &unpdg_recvspace, 0, "Default datagram receive space."); 155 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 156 "File descriptors in flight."); 157 158 /*- 159 * Locking and synchronization: 160 * 161 * Three types of locks exit in the local domain socket implementation: a 162 * global list mutex, a global linkage rwlock, and per-unpcb mutexes. Of the 163 * global locks, the list lock protects the socket count, global generation 164 * number, and stream/datagram global lists. The linkage lock protects the 165 * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be 166 * held exclusively over the acquisition of multiple unpcb locks to prevent 167 * deadlock. 168 * 169 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 170 * allocated in pru_attach() and freed in pru_detach(). The validity of that 171 * pointer is an invariant, so no lock is required to dereference the so_pcb 172 * pointer if a valid socket reference is held by the caller. In practice, 173 * this is always true during operations performed on a socket. Each unpcb 174 * has a back-pointer to its socket, unp_socket, which will be stable under 175 * the same circumstances. 176 * 177 * This pointer may only be safely dereferenced as long as a valid reference 178 * to the unpcb is held. Typically, this reference will be from the socket, 179 * or from another unpcb when the referring unpcb's lock is held (in order 180 * that the reference not be invalidated during use). For example, to follow 181 * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn, 182 * as unp_socket remains valid as long as the reference to unp_conn is valid. 183 * 184 * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual 185 * atomic reads without the lock may be performed "lockless", but more 186 * complex reads and read-modify-writes require the mutex to be held. No 187 * lock order is defined between unpcb locks -- multiple unpcb locks may be 188 * acquired at the same time only when holding the linkage rwlock 189 * exclusively, which prevents deadlocks. 190 * 191 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 192 * protocols, bind() is a non-atomic operation, and connect() requires 193 * potential sleeping in the protocol, due to potentially waiting on local or 194 * distributed file systems. We try to separate "lookup" operations, which 195 * may sleep, and the IPC operations themselves, which typically can occur 196 * with relative atomicity as locks can be held over the entire operation. 197 * 198 * Another tricky issue is simultaneous multi-threaded or multi-process 199 * access to a single UNIX domain socket. These are handled by the flags 200 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 201 * binding, both of which involve dropping UNIX domain socket locks in order 202 * to perform namei() and other file system operations. 203 */ 204 static struct rwlock unp_link_rwlock; 205 static struct mtx unp_list_lock; 206 207 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 208 "unp_link_rwlock") 209 210 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 211 RA_LOCKED) 212 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 213 RA_UNLOCKED) 214 215 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 216 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 217 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 218 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 219 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 220 RA_WLOCKED) 221 222 #define UNP_LIST_LOCK_INIT() mtx_init(&unp_list_lock, \ 223 "unp_list_lock", NULL, MTX_DEF) 224 #define UNP_LIST_LOCK() mtx_lock(&unp_list_lock) 225 #define UNP_LIST_UNLOCK() mtx_unlock(&unp_list_lock) 226 227 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 228 "unp_mtx", "unp_mtx", \ 229 MTX_DUPOK|MTX_DEF|MTX_RECURSE) 230 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 231 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 232 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 233 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 234 235 static int uipc_connect2(struct socket *, struct socket *); 236 static int uipc_ctloutput(struct socket *, struct sockopt *); 237 static int unp_connect(struct socket *, struct sockaddr *, 238 struct thread *); 239 static int unp_connect2(struct socket *so, struct socket *so2, int); 240 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 241 static void unp_dispose(struct mbuf *); 242 static void unp_shutdown(struct unpcb *); 243 static void unp_drop(struct unpcb *, int); 244 static void unp_gc(__unused void *, int); 245 static void unp_scan(struct mbuf *, void (*)(struct file *)); 246 static void unp_discard(struct file *); 247 static void unp_freerights(struct file **, int); 248 static void unp_init(void); 249 static int unp_internalize(struct mbuf **, struct thread *); 250 static void unp_internalize_fp(struct file *); 251 static int unp_externalize(struct mbuf *, struct mbuf **); 252 static void unp_externalize_fp(struct file *); 253 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 254 255 /* 256 * Definitions of protocols supported in the LOCAL domain. 257 */ 258 static struct domain localdomain; 259 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 260 static struct protosw localsw[] = { 261 { 262 .pr_type = SOCK_STREAM, 263 .pr_domain = &localdomain, 264 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 265 .pr_ctloutput = &uipc_ctloutput, 266 .pr_usrreqs = &uipc_usrreqs_stream 267 }, 268 { 269 .pr_type = SOCK_DGRAM, 270 .pr_domain = &localdomain, 271 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 272 .pr_usrreqs = &uipc_usrreqs_dgram 273 }, 274 }; 275 276 static struct domain localdomain = { 277 .dom_family = AF_LOCAL, 278 .dom_name = "local", 279 .dom_init = unp_init, 280 .dom_externalize = unp_externalize, 281 .dom_dispose = unp_dispose, 282 .dom_protosw = localsw, 283 .dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])] 284 }; 285 DOMAIN_SET(local); 286 287 static void 288 uipc_abort(struct socket *so) 289 { 290 struct unpcb *unp, *unp2; 291 292 unp = sotounpcb(so); 293 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 294 295 UNP_LINK_WLOCK(); 296 UNP_PCB_LOCK(unp); 297 unp2 = unp->unp_conn; 298 if (unp2 != NULL) { 299 UNP_PCB_LOCK(unp2); 300 unp_drop(unp2, ECONNABORTED); 301 UNP_PCB_UNLOCK(unp2); 302 } 303 UNP_PCB_UNLOCK(unp); 304 UNP_LINK_WUNLOCK(); 305 } 306 307 static int 308 uipc_accept(struct socket *so, struct sockaddr **nam) 309 { 310 struct unpcb *unp, *unp2; 311 const struct sockaddr *sa; 312 313 /* 314 * Pass back name of connected socket, if it was bound and we are 315 * still connected (our peer may have closed already!). 316 */ 317 unp = sotounpcb(so); 318 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 319 320 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 321 UNP_LINK_RLOCK(); 322 unp2 = unp->unp_conn; 323 if (unp2 != NULL && unp2->unp_addr != NULL) { 324 UNP_PCB_LOCK(unp2); 325 sa = (struct sockaddr *) unp2->unp_addr; 326 bcopy(sa, *nam, sa->sa_len); 327 UNP_PCB_UNLOCK(unp2); 328 } else { 329 sa = &sun_noname; 330 bcopy(sa, *nam, sa->sa_len); 331 } 332 UNP_LINK_RUNLOCK(); 333 return (0); 334 } 335 336 static int 337 uipc_attach(struct socket *so, int proto, struct thread *td) 338 { 339 u_long sendspace, recvspace; 340 struct unpcb *unp; 341 int error; 342 343 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 344 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 345 switch (so->so_type) { 346 case SOCK_STREAM: 347 sendspace = unpst_sendspace; 348 recvspace = unpst_recvspace; 349 break; 350 351 case SOCK_DGRAM: 352 sendspace = unpdg_sendspace; 353 recvspace = unpdg_recvspace; 354 break; 355 356 default: 357 panic("uipc_attach"); 358 } 359 error = soreserve(so, sendspace, recvspace); 360 if (error) 361 return (error); 362 } 363 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 364 if (unp == NULL) 365 return (ENOBUFS); 366 LIST_INIT(&unp->unp_refs); 367 UNP_PCB_LOCK_INIT(unp); 368 unp->unp_socket = so; 369 so->so_pcb = unp; 370 unp->unp_refcount = 1; 371 372 UNP_LIST_LOCK(); 373 unp->unp_gencnt = ++unp_gencnt; 374 unp_count++; 375 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead : &unp_shead, 376 unp, unp_link); 377 UNP_LIST_UNLOCK(); 378 379 return (0); 380 } 381 382 static int 383 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 384 { 385 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 386 struct vattr vattr; 387 int error, namelen, vfslocked; 388 struct nameidata nd; 389 struct unpcb *unp; 390 struct vnode *vp; 391 struct mount *mp; 392 char *buf; 393 394 unp = sotounpcb(so); 395 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 396 397 if (soun->sun_len > sizeof(struct sockaddr_un)) 398 return (EINVAL); 399 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 400 if (namelen <= 0) 401 return (EINVAL); 402 403 /* 404 * We don't allow simultaneous bind() calls on a single UNIX domain 405 * socket, so flag in-progress operations, and return an error if an 406 * operation is already in progress. 407 * 408 * Historically, we have not allowed a socket to be rebound, so this 409 * also returns an error. Not allowing re-binding simplifies the 410 * implementation and avoids a great many possible failure modes. 411 */ 412 UNP_PCB_LOCK(unp); 413 if (unp->unp_vnode != NULL) { 414 UNP_PCB_UNLOCK(unp); 415 return (EINVAL); 416 } 417 if (unp->unp_flags & UNP_BINDING) { 418 UNP_PCB_UNLOCK(unp); 419 return (EALREADY); 420 } 421 unp->unp_flags |= UNP_BINDING; 422 UNP_PCB_UNLOCK(unp); 423 424 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 425 bcopy(soun->sun_path, buf, namelen); 426 buf[namelen] = 0; 427 428 restart: 429 vfslocked = 0; 430 NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME, 431 UIO_SYSSPACE, buf, td); 432 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 433 error = namei(&nd); 434 if (error) 435 goto error; 436 vp = nd.ni_vp; 437 vfslocked = NDHASGIANT(&nd); 438 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 439 NDFREE(&nd, NDF_ONLY_PNBUF); 440 if (nd.ni_dvp == vp) 441 vrele(nd.ni_dvp); 442 else 443 vput(nd.ni_dvp); 444 if (vp != NULL) { 445 vrele(vp); 446 error = EADDRINUSE; 447 goto error; 448 } 449 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 450 if (error) 451 goto error; 452 VFS_UNLOCK_GIANT(vfslocked); 453 goto restart; 454 } 455 VATTR_NULL(&vattr); 456 vattr.va_type = VSOCK; 457 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 458 #ifdef MAC 459 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 460 &vattr); 461 #endif 462 if (error == 0) 463 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 464 NDFREE(&nd, NDF_ONLY_PNBUF); 465 vput(nd.ni_dvp); 466 if (error) { 467 vn_finished_write(mp); 468 goto error; 469 } 470 vp = nd.ni_vp; 471 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 472 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 473 474 UNP_LINK_WLOCK(); 475 UNP_PCB_LOCK(unp); 476 vp->v_socket = unp->unp_socket; 477 unp->unp_vnode = vp; 478 unp->unp_addr = soun; 479 unp->unp_flags &= ~UNP_BINDING; 480 UNP_PCB_UNLOCK(unp); 481 UNP_LINK_WUNLOCK(); 482 VOP_UNLOCK(vp, 0); 483 vn_finished_write(mp); 484 VFS_UNLOCK_GIANT(vfslocked); 485 free(buf, M_TEMP); 486 return (0); 487 488 error: 489 VFS_UNLOCK_GIANT(vfslocked); 490 UNP_PCB_LOCK(unp); 491 unp->unp_flags &= ~UNP_BINDING; 492 UNP_PCB_UNLOCK(unp); 493 free(buf, M_TEMP); 494 return (error); 495 } 496 497 static int 498 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 499 { 500 int error; 501 502 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 503 UNP_LINK_WLOCK(); 504 error = unp_connect(so, nam, td); 505 UNP_LINK_WUNLOCK(); 506 return (error); 507 } 508 509 static void 510 uipc_close(struct socket *so) 511 { 512 struct unpcb *unp, *unp2; 513 514 unp = sotounpcb(so); 515 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 516 517 UNP_LINK_WLOCK(); 518 UNP_PCB_LOCK(unp); 519 unp2 = unp->unp_conn; 520 if (unp2 != NULL) { 521 UNP_PCB_LOCK(unp2); 522 unp_disconnect(unp, unp2); 523 UNP_PCB_UNLOCK(unp2); 524 } 525 UNP_PCB_UNLOCK(unp); 526 UNP_LINK_WUNLOCK(); 527 } 528 529 static int 530 uipc_connect2(struct socket *so1, struct socket *so2) 531 { 532 struct unpcb *unp, *unp2; 533 int error; 534 535 UNP_LINK_WLOCK(); 536 unp = so1->so_pcb; 537 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 538 UNP_PCB_LOCK(unp); 539 unp2 = so2->so_pcb; 540 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 541 UNP_PCB_LOCK(unp2); 542 error = unp_connect2(so1, so2, PRU_CONNECT2); 543 UNP_PCB_UNLOCK(unp2); 544 UNP_PCB_UNLOCK(unp); 545 UNP_LINK_WUNLOCK(); 546 return (error); 547 } 548 549 static void 550 uipc_detach(struct socket *so) 551 { 552 struct unpcb *unp, *unp2; 553 struct sockaddr_un *saved_unp_addr; 554 struct vnode *vp; 555 int freeunp, local_unp_rights; 556 557 unp = sotounpcb(so); 558 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 559 560 UNP_LINK_WLOCK(); 561 UNP_LIST_LOCK(); 562 UNP_PCB_LOCK(unp); 563 LIST_REMOVE(unp, unp_link); 564 unp->unp_gencnt = ++unp_gencnt; 565 --unp_count; 566 UNP_LIST_UNLOCK(); 567 568 /* 569 * XXXRW: Should assert vp->v_socket == so. 570 */ 571 if ((vp = unp->unp_vnode) != NULL) { 572 unp->unp_vnode->v_socket = NULL; 573 unp->unp_vnode = NULL; 574 } 575 unp2 = unp->unp_conn; 576 if (unp2 != NULL) { 577 UNP_PCB_LOCK(unp2); 578 unp_disconnect(unp, unp2); 579 UNP_PCB_UNLOCK(unp2); 580 } 581 582 /* 583 * We hold the linkage lock exclusively, so it's OK to acquire 584 * multiple pcb locks at a time. 585 */ 586 while (!LIST_EMPTY(&unp->unp_refs)) { 587 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 588 589 UNP_PCB_LOCK(ref); 590 unp_drop(ref, ECONNRESET); 591 UNP_PCB_UNLOCK(ref); 592 } 593 local_unp_rights = unp_rights; 594 UNP_LINK_WUNLOCK(); 595 unp->unp_socket->so_pcb = NULL; 596 saved_unp_addr = unp->unp_addr; 597 unp->unp_addr = NULL; 598 unp->unp_refcount--; 599 freeunp = (unp->unp_refcount == 0); 600 if (saved_unp_addr != NULL) 601 free(saved_unp_addr, M_SONAME); 602 if (freeunp) { 603 UNP_PCB_LOCK_DESTROY(unp); 604 uma_zfree(unp_zone, unp); 605 } else 606 UNP_PCB_UNLOCK(unp); 607 if (vp) { 608 int vfslocked; 609 610 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 611 vrele(vp); 612 VFS_UNLOCK_GIANT(vfslocked); 613 } 614 if (local_unp_rights) 615 taskqueue_enqueue(taskqueue_thread, &unp_gc_task); 616 } 617 618 static int 619 uipc_disconnect(struct socket *so) 620 { 621 struct unpcb *unp, *unp2; 622 623 unp = sotounpcb(so); 624 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 625 626 UNP_LINK_WLOCK(); 627 UNP_PCB_LOCK(unp); 628 unp2 = unp->unp_conn; 629 if (unp2 != NULL) { 630 UNP_PCB_LOCK(unp2); 631 unp_disconnect(unp, unp2); 632 UNP_PCB_UNLOCK(unp2); 633 } 634 UNP_PCB_UNLOCK(unp); 635 UNP_LINK_WUNLOCK(); 636 return (0); 637 } 638 639 static int 640 uipc_listen(struct socket *so, int backlog, struct thread *td) 641 { 642 struct unpcb *unp; 643 int error; 644 645 unp = sotounpcb(so); 646 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 647 648 UNP_PCB_LOCK(unp); 649 if (unp->unp_vnode == NULL) { 650 UNP_PCB_UNLOCK(unp); 651 return (EINVAL); 652 } 653 654 SOCK_LOCK(so); 655 error = solisten_proto_check(so); 656 if (error == 0) { 657 cru2x(td->td_ucred, &unp->unp_peercred); 658 unp->unp_flags |= UNP_HAVEPCCACHED; 659 solisten_proto(so, backlog); 660 } 661 SOCK_UNLOCK(so); 662 UNP_PCB_UNLOCK(unp); 663 return (error); 664 } 665 666 static int 667 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 668 { 669 struct unpcb *unp, *unp2; 670 const struct sockaddr *sa; 671 672 unp = sotounpcb(so); 673 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 674 675 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 676 UNP_LINK_RLOCK(); 677 /* 678 * XXX: It seems that this test always fails even when connection is 679 * established. So, this else clause is added as workaround to 680 * return PF_LOCAL sockaddr. 681 */ 682 unp2 = unp->unp_conn; 683 if (unp2 != NULL) { 684 UNP_PCB_LOCK(unp2); 685 if (unp2->unp_addr != NULL) 686 sa = (struct sockaddr *) unp2->unp_addr; 687 else 688 sa = &sun_noname; 689 bcopy(sa, *nam, sa->sa_len); 690 UNP_PCB_UNLOCK(unp2); 691 } else { 692 sa = &sun_noname; 693 bcopy(sa, *nam, sa->sa_len); 694 } 695 UNP_LINK_RUNLOCK(); 696 return (0); 697 } 698 699 static int 700 uipc_rcvd(struct socket *so, int flags) 701 { 702 struct unpcb *unp, *unp2; 703 struct socket *so2; 704 u_int mbcnt, sbcc; 705 u_long newhiwat; 706 707 unp = sotounpcb(so); 708 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL")); 709 710 if (so->so_type == SOCK_DGRAM) 711 panic("uipc_rcvd DGRAM?"); 712 713 if (so->so_type != SOCK_STREAM) 714 panic("uipc_rcvd unknown socktype"); 715 716 /* 717 * Adjust backpressure on sender and wakeup any waiting to write. 718 * 719 * The unp lock is acquired to maintain the validity of the unp_conn 720 * pointer; no lock on unp2 is required as unp2->unp_socket will be 721 * static as long as we don't permit unp2 to disconnect from unp, 722 * which is prevented by the lock on unp. We cache values from 723 * so_rcv to avoid holding the so_rcv lock over the entire 724 * transaction on the remote so_snd. 725 */ 726 SOCKBUF_LOCK(&so->so_rcv); 727 mbcnt = so->so_rcv.sb_mbcnt; 728 sbcc = so->so_rcv.sb_cc; 729 SOCKBUF_UNLOCK(&so->so_rcv); 730 UNP_PCB_LOCK(unp); 731 unp2 = unp->unp_conn; 732 if (unp2 == NULL) { 733 UNP_PCB_UNLOCK(unp); 734 return (0); 735 } 736 so2 = unp2->unp_socket; 737 SOCKBUF_LOCK(&so2->so_snd); 738 so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt; 739 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc; 740 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, 741 newhiwat, RLIM_INFINITY); 742 sowwakeup_locked(so2); 743 unp->unp_mbcnt = mbcnt; 744 unp->unp_cc = sbcc; 745 UNP_PCB_UNLOCK(unp); 746 return (0); 747 } 748 749 static int 750 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 751 struct mbuf *control, struct thread *td) 752 { 753 struct unpcb *unp, *unp2; 754 struct socket *so2; 755 u_int mbcnt_delta, sbcc; 756 u_long newhiwat; 757 int error = 0; 758 759 unp = sotounpcb(so); 760 KASSERT(unp != NULL, ("uipc_send: unp == NULL")); 761 762 if (flags & PRUS_OOB) { 763 error = EOPNOTSUPP; 764 goto release; 765 } 766 if (control != NULL && (error = unp_internalize(&control, td))) 767 goto release; 768 if ((nam != NULL) || (flags & PRUS_EOF)) 769 UNP_LINK_WLOCK(); 770 else 771 UNP_LINK_RLOCK(); 772 switch (so->so_type) { 773 case SOCK_DGRAM: 774 { 775 const struct sockaddr *from; 776 777 unp2 = unp->unp_conn; 778 if (nam != NULL) { 779 UNP_LINK_WLOCK_ASSERT(); 780 if (unp2 != NULL) { 781 error = EISCONN; 782 break; 783 } 784 error = unp_connect(so, nam, td); 785 if (error) 786 break; 787 unp2 = unp->unp_conn; 788 } 789 790 /* 791 * Because connect() and send() are non-atomic in a sendto() 792 * with a target address, it's possible that the socket will 793 * have disconnected before the send() can run. In that case 794 * return the slightly counter-intuitive but otherwise 795 * correct error that the socket is not connected. 796 */ 797 if (unp2 == NULL) { 798 error = ENOTCONN; 799 break; 800 } 801 /* Lockless read. */ 802 if (unp2->unp_flags & UNP_WANTCRED) 803 control = unp_addsockcred(td, control); 804 UNP_PCB_LOCK(unp); 805 if (unp->unp_addr != NULL) 806 from = (struct sockaddr *)unp->unp_addr; 807 else 808 from = &sun_noname; 809 so2 = unp2->unp_socket; 810 SOCKBUF_LOCK(&so2->so_rcv); 811 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) { 812 sorwakeup_locked(so2); 813 m = NULL; 814 control = NULL; 815 } else { 816 SOCKBUF_UNLOCK(&so2->so_rcv); 817 error = ENOBUFS; 818 } 819 if (nam != NULL) { 820 UNP_LINK_WLOCK_ASSERT(); 821 UNP_PCB_LOCK(unp2); 822 unp_disconnect(unp, unp2); 823 UNP_PCB_UNLOCK(unp2); 824 } 825 UNP_PCB_UNLOCK(unp); 826 break; 827 } 828 829 case SOCK_STREAM: 830 if ((so->so_state & SS_ISCONNECTED) == 0) { 831 if (nam != NULL) { 832 UNP_LINK_WLOCK_ASSERT(); 833 error = unp_connect(so, nam, td); 834 if (error) 835 break; /* XXX */ 836 } else { 837 error = ENOTCONN; 838 break; 839 } 840 } 841 842 /* Lockless read. */ 843 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 844 error = EPIPE; 845 break; 846 } 847 848 /* 849 * Because connect() and send() are non-atomic in a sendto() 850 * with a target address, it's possible that the socket will 851 * have disconnected before the send() can run. In that case 852 * return the slightly counter-intuitive but otherwise 853 * correct error that the socket is not connected. 854 * 855 * Locking here must be done carefully: the linkage lock 856 * prevents interconnections between unpcbs from changing, so 857 * we can traverse from unp to unp2 without acquiring unp's 858 * lock. Socket buffer locks follow unpcb locks, so we can 859 * acquire both remote and lock socket buffer locks. 860 */ 861 unp2 = unp->unp_conn; 862 if (unp2 == NULL) { 863 error = ENOTCONN; 864 break; 865 } 866 so2 = unp2->unp_socket; 867 UNP_PCB_LOCK(unp2); 868 SOCKBUF_LOCK(&so2->so_rcv); 869 if (unp2->unp_flags & UNP_WANTCRED) { 870 /* 871 * Credentials are passed only once on SOCK_STREAM. 872 */ 873 unp2->unp_flags &= ~UNP_WANTCRED; 874 control = unp_addsockcred(td, control); 875 } 876 /* 877 * Send to paired receive port, and then reduce send buffer 878 * hiwater marks to maintain backpressure. Wake up readers. 879 */ 880 if (control != NULL) { 881 if (sbappendcontrol_locked(&so2->so_rcv, m, control)) 882 control = NULL; 883 } else 884 sbappend_locked(&so2->so_rcv, m); 885 mbcnt_delta = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt; 886 unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt; 887 sbcc = so2->so_rcv.sb_cc; 888 sorwakeup_locked(so2); 889 890 SOCKBUF_LOCK(&so->so_snd); 891 newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc); 892 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, 893 newhiwat, RLIM_INFINITY); 894 so->so_snd.sb_mbmax -= mbcnt_delta; 895 SOCKBUF_UNLOCK(&so->so_snd); 896 unp2->unp_cc = sbcc; 897 UNP_PCB_UNLOCK(unp2); 898 m = NULL; 899 break; 900 901 default: 902 panic("uipc_send unknown socktype"); 903 } 904 905 /* 906 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 907 */ 908 if (flags & PRUS_EOF) { 909 UNP_PCB_LOCK(unp); 910 socantsendmore(so); 911 unp_shutdown(unp); 912 UNP_PCB_UNLOCK(unp); 913 } 914 915 if ((nam != NULL) || (flags & PRUS_EOF)) 916 UNP_LINK_WUNLOCK(); 917 else 918 UNP_LINK_RUNLOCK(); 919 920 if (control != NULL && error != 0) 921 unp_dispose(control); 922 923 release: 924 if (control != NULL) 925 m_freem(control); 926 if (m != NULL) 927 m_freem(m); 928 return (error); 929 } 930 931 static int 932 uipc_sense(struct socket *so, struct stat *sb) 933 { 934 struct unpcb *unp, *unp2; 935 struct socket *so2; 936 937 unp = sotounpcb(so); 938 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 939 940 sb->st_blksize = so->so_snd.sb_hiwat; 941 UNP_LINK_RLOCK(); 942 UNP_PCB_LOCK(unp); 943 unp2 = unp->unp_conn; 944 if (so->so_type == SOCK_STREAM && unp2 != NULL) { 945 so2 = unp2->unp_socket; 946 sb->st_blksize += so2->so_rcv.sb_cc; 947 } 948 sb->st_dev = NODEV; 949 if (unp->unp_ino == 0) 950 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 951 sb->st_ino = unp->unp_ino; 952 UNP_PCB_UNLOCK(unp); 953 UNP_LINK_RUNLOCK(); 954 return (0); 955 } 956 957 static int 958 uipc_shutdown(struct socket *so) 959 { 960 struct unpcb *unp; 961 962 unp = sotounpcb(so); 963 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 964 965 UNP_LINK_WLOCK(); 966 UNP_PCB_LOCK(unp); 967 socantsendmore(so); 968 unp_shutdown(unp); 969 UNP_PCB_UNLOCK(unp); 970 UNP_LINK_WUNLOCK(); 971 return (0); 972 } 973 974 static int 975 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 976 { 977 struct unpcb *unp; 978 const struct sockaddr *sa; 979 980 unp = sotounpcb(so); 981 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 982 983 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 984 UNP_PCB_LOCK(unp); 985 if (unp->unp_addr != NULL) 986 sa = (struct sockaddr *) unp->unp_addr; 987 else 988 sa = &sun_noname; 989 bcopy(sa, *nam, sa->sa_len); 990 UNP_PCB_UNLOCK(unp); 991 return (0); 992 } 993 994 static struct pr_usrreqs uipc_usrreqs_dgram = { 995 .pru_abort = uipc_abort, 996 .pru_accept = uipc_accept, 997 .pru_attach = uipc_attach, 998 .pru_bind = uipc_bind, 999 .pru_connect = uipc_connect, 1000 .pru_connect2 = uipc_connect2, 1001 .pru_detach = uipc_detach, 1002 .pru_disconnect = uipc_disconnect, 1003 .pru_listen = uipc_listen, 1004 .pru_peeraddr = uipc_peeraddr, 1005 .pru_rcvd = uipc_rcvd, 1006 .pru_send = uipc_send, 1007 .pru_sense = uipc_sense, 1008 .pru_shutdown = uipc_shutdown, 1009 .pru_sockaddr = uipc_sockaddr, 1010 .pru_soreceive = soreceive_dgram, 1011 .pru_close = uipc_close, 1012 }; 1013 1014 static struct pr_usrreqs uipc_usrreqs_stream = { 1015 .pru_abort = uipc_abort, 1016 .pru_accept = uipc_accept, 1017 .pru_attach = uipc_attach, 1018 .pru_bind = uipc_bind, 1019 .pru_connect = uipc_connect, 1020 .pru_connect2 = uipc_connect2, 1021 .pru_detach = uipc_detach, 1022 .pru_disconnect = uipc_disconnect, 1023 .pru_listen = uipc_listen, 1024 .pru_peeraddr = uipc_peeraddr, 1025 .pru_rcvd = uipc_rcvd, 1026 .pru_send = uipc_send, 1027 .pru_sense = uipc_sense, 1028 .pru_shutdown = uipc_shutdown, 1029 .pru_sockaddr = uipc_sockaddr, 1030 .pru_soreceive = soreceive_generic, 1031 .pru_close = uipc_close, 1032 }; 1033 1034 static int 1035 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1036 { 1037 struct unpcb *unp; 1038 struct xucred xu; 1039 int error, optval; 1040 1041 if (sopt->sopt_level != 0) 1042 return (EINVAL); 1043 1044 unp = sotounpcb(so); 1045 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1046 error = 0; 1047 switch (sopt->sopt_dir) { 1048 case SOPT_GET: 1049 switch (sopt->sopt_name) { 1050 case LOCAL_PEERCRED: 1051 UNP_PCB_LOCK(unp); 1052 if (unp->unp_flags & UNP_HAVEPC) 1053 xu = unp->unp_peercred; 1054 else { 1055 if (so->so_type == SOCK_STREAM) 1056 error = ENOTCONN; 1057 else 1058 error = EINVAL; 1059 } 1060 UNP_PCB_UNLOCK(unp); 1061 if (error == 0) 1062 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1063 break; 1064 1065 case LOCAL_CREDS: 1066 /* Unlocked read. */ 1067 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1068 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1069 break; 1070 1071 case LOCAL_CONNWAIT: 1072 /* Unlocked read. */ 1073 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1074 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1075 break; 1076 1077 default: 1078 error = EOPNOTSUPP; 1079 break; 1080 } 1081 break; 1082 1083 case SOPT_SET: 1084 switch (sopt->sopt_name) { 1085 case LOCAL_CREDS: 1086 case LOCAL_CONNWAIT: 1087 error = sooptcopyin(sopt, &optval, sizeof(optval), 1088 sizeof(optval)); 1089 if (error) 1090 break; 1091 1092 #define OPTSET(bit) do { \ 1093 UNP_PCB_LOCK(unp); \ 1094 if (optval) \ 1095 unp->unp_flags |= bit; \ 1096 else \ 1097 unp->unp_flags &= ~bit; \ 1098 UNP_PCB_UNLOCK(unp); \ 1099 } while (0) 1100 1101 switch (sopt->sopt_name) { 1102 case LOCAL_CREDS: 1103 OPTSET(UNP_WANTCRED); 1104 break; 1105 1106 case LOCAL_CONNWAIT: 1107 OPTSET(UNP_CONNWAIT); 1108 break; 1109 1110 default: 1111 break; 1112 } 1113 break; 1114 #undef OPTSET 1115 default: 1116 error = ENOPROTOOPT; 1117 break; 1118 } 1119 break; 1120 1121 default: 1122 error = EOPNOTSUPP; 1123 break; 1124 } 1125 return (error); 1126 } 1127 1128 static int 1129 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1130 { 1131 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1132 struct vnode *vp; 1133 struct socket *so2, *so3; 1134 struct unpcb *unp, *unp2, *unp3; 1135 int error, len, vfslocked; 1136 struct nameidata nd; 1137 char buf[SOCK_MAXADDRLEN]; 1138 struct sockaddr *sa; 1139 1140 UNP_LINK_WLOCK_ASSERT(); 1141 1142 unp = sotounpcb(so); 1143 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1144 1145 if (nam->sa_len > sizeof(struct sockaddr_un)) 1146 return (EINVAL); 1147 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1148 if (len <= 0) 1149 return (EINVAL); 1150 bcopy(soun->sun_path, buf, len); 1151 buf[len] = 0; 1152 1153 UNP_PCB_LOCK(unp); 1154 if (unp->unp_flags & UNP_CONNECTING) { 1155 UNP_PCB_UNLOCK(unp); 1156 return (EALREADY); 1157 } 1158 UNP_LINK_WUNLOCK(); 1159 unp->unp_flags |= UNP_CONNECTING; 1160 UNP_PCB_UNLOCK(unp); 1161 1162 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1163 NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, 1164 td); 1165 error = namei(&nd); 1166 if (error) 1167 vp = NULL; 1168 else 1169 vp = nd.ni_vp; 1170 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1171 vfslocked = NDHASGIANT(&nd); 1172 NDFREE(&nd, NDF_ONLY_PNBUF); 1173 if (error) 1174 goto bad; 1175 1176 if (vp->v_type != VSOCK) { 1177 error = ENOTSOCK; 1178 goto bad; 1179 } 1180 #ifdef MAC 1181 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1182 if (error) 1183 goto bad; 1184 #endif 1185 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1186 if (error) 1187 goto bad; 1188 VFS_UNLOCK_GIANT(vfslocked); 1189 1190 unp = sotounpcb(so); 1191 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1192 1193 /* 1194 * Lock linkage lock for two reasons: make sure v_socket is stable, 1195 * and to protect simultaneous locking of multiple pcbs. 1196 */ 1197 UNP_LINK_WLOCK(); 1198 so2 = vp->v_socket; 1199 if (so2 == NULL) { 1200 error = ECONNREFUSED; 1201 goto bad2; 1202 } 1203 if (so->so_type != so2->so_type) { 1204 error = EPROTOTYPE; 1205 goto bad2; 1206 } 1207 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1208 if (so2->so_options & SO_ACCEPTCONN) { 1209 so3 = sonewconn(so2, 0); 1210 } else 1211 so3 = NULL; 1212 if (so3 == NULL) { 1213 error = ECONNREFUSED; 1214 goto bad2; 1215 } 1216 unp = sotounpcb(so); 1217 unp2 = sotounpcb(so2); 1218 unp3 = sotounpcb(so3); 1219 UNP_PCB_LOCK(unp); 1220 UNP_PCB_LOCK(unp2); 1221 UNP_PCB_LOCK(unp3); 1222 if (unp2->unp_addr != NULL) { 1223 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1224 unp3->unp_addr = (struct sockaddr_un *) sa; 1225 sa = NULL; 1226 } 1227 1228 /* 1229 * The connecter's (client's) credentials are copied from its 1230 * process structure at the time of connect() (which is now). 1231 */ 1232 cru2x(td->td_ucred, &unp3->unp_peercred); 1233 unp3->unp_flags |= UNP_HAVEPC; 1234 1235 /* 1236 * The receiver's (server's) credentials are copied from the 1237 * unp_peercred member of socket on which the former called 1238 * listen(); uipc_listen() cached that process's credentials 1239 * at that time so we can use them now. 1240 */ 1241 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1242 ("unp_connect: listener without cached peercred")); 1243 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1244 sizeof(unp->unp_peercred)); 1245 unp->unp_flags |= UNP_HAVEPC; 1246 if (unp2->unp_flags & UNP_WANTCRED) 1247 unp3->unp_flags |= UNP_WANTCRED; 1248 UNP_PCB_UNLOCK(unp3); 1249 UNP_PCB_UNLOCK(unp2); 1250 UNP_PCB_UNLOCK(unp); 1251 #ifdef MAC 1252 mac_socketpeer_set_from_socket(so, so3); 1253 mac_socketpeer_set_from_socket(so3, so); 1254 #endif 1255 1256 so2 = so3; 1257 } 1258 unp = sotounpcb(so); 1259 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1260 unp2 = sotounpcb(so2); 1261 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL")); 1262 UNP_PCB_LOCK(unp); 1263 UNP_PCB_LOCK(unp2); 1264 error = unp_connect2(so, so2, PRU_CONNECT); 1265 UNP_PCB_UNLOCK(unp2); 1266 UNP_PCB_UNLOCK(unp); 1267 bad2: 1268 UNP_LINK_WUNLOCK(); 1269 if (vfslocked) 1270 /* 1271 * Giant has been previously acquired. This means filesystem 1272 * isn't MPSAFE. Do it once again. 1273 */ 1274 mtx_lock(&Giant); 1275 bad: 1276 if (vp != NULL) 1277 vput(vp); 1278 VFS_UNLOCK_GIANT(vfslocked); 1279 free(sa, M_SONAME); 1280 UNP_LINK_WLOCK(); 1281 UNP_PCB_LOCK(unp); 1282 unp->unp_flags &= ~UNP_CONNECTING; 1283 UNP_PCB_UNLOCK(unp); 1284 return (error); 1285 } 1286 1287 static int 1288 unp_connect2(struct socket *so, struct socket *so2, int req) 1289 { 1290 struct unpcb *unp; 1291 struct unpcb *unp2; 1292 1293 unp = sotounpcb(so); 1294 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1295 unp2 = sotounpcb(so2); 1296 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1297 1298 UNP_LINK_WLOCK_ASSERT(); 1299 UNP_PCB_LOCK_ASSERT(unp); 1300 UNP_PCB_LOCK_ASSERT(unp2); 1301 1302 if (so2->so_type != so->so_type) 1303 return (EPROTOTYPE); 1304 unp->unp_conn = unp2; 1305 1306 switch (so->so_type) { 1307 case SOCK_DGRAM: 1308 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1309 soisconnected(so); 1310 break; 1311 1312 case SOCK_STREAM: 1313 unp2->unp_conn = unp; 1314 if (req == PRU_CONNECT && 1315 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1316 soisconnecting(so); 1317 else 1318 soisconnected(so); 1319 soisconnected(so2); 1320 break; 1321 1322 default: 1323 panic("unp_connect2"); 1324 } 1325 return (0); 1326 } 1327 1328 static void 1329 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1330 { 1331 struct socket *so; 1332 1333 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1334 1335 UNP_LINK_WLOCK_ASSERT(); 1336 UNP_PCB_LOCK_ASSERT(unp); 1337 UNP_PCB_LOCK_ASSERT(unp2); 1338 1339 unp->unp_conn = NULL; 1340 switch (unp->unp_socket->so_type) { 1341 case SOCK_DGRAM: 1342 LIST_REMOVE(unp, unp_reflink); 1343 so = unp->unp_socket; 1344 SOCK_LOCK(so); 1345 so->so_state &= ~SS_ISCONNECTED; 1346 SOCK_UNLOCK(so); 1347 break; 1348 1349 case SOCK_STREAM: 1350 soisdisconnected(unp->unp_socket); 1351 unp2->unp_conn = NULL; 1352 soisdisconnected(unp2->unp_socket); 1353 break; 1354 } 1355 } 1356 1357 /* 1358 * unp_pcblist() walks the global list of struct unpcb's to generate a 1359 * pointer list, bumping the refcount on each unpcb. It then copies them out 1360 * sequentially, validating the generation number on each to see if it has 1361 * been detached. All of this is necessary because copyout() may sleep on 1362 * disk I/O. 1363 */ 1364 static int 1365 unp_pcblist(SYSCTL_HANDLER_ARGS) 1366 { 1367 int error, i, n; 1368 int freeunp; 1369 struct unpcb *unp, **unp_list; 1370 unp_gen_t gencnt; 1371 struct xunpgen *xug; 1372 struct unp_head *head; 1373 struct xunpcb *xu; 1374 1375 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 1376 1377 /* 1378 * The process of preparing the PCB list is too time-consuming and 1379 * resource-intensive to repeat twice on every request. 1380 */ 1381 if (req->oldptr == NULL) { 1382 n = unp_count; 1383 req->oldidx = 2 * (sizeof *xug) 1384 + (n + n/8) * sizeof(struct xunpcb); 1385 return (0); 1386 } 1387 1388 if (req->newptr != NULL) 1389 return (EPERM); 1390 1391 /* 1392 * OK, now we're committed to doing something. 1393 */ 1394 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1395 UNP_LIST_LOCK(); 1396 gencnt = unp_gencnt; 1397 n = unp_count; 1398 UNP_LIST_UNLOCK(); 1399 1400 xug->xug_len = sizeof *xug; 1401 xug->xug_count = n; 1402 xug->xug_gen = gencnt; 1403 xug->xug_sogen = so_gencnt; 1404 error = SYSCTL_OUT(req, xug, sizeof *xug); 1405 if (error) { 1406 free(xug, M_TEMP); 1407 return (error); 1408 } 1409 1410 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1411 1412 UNP_LIST_LOCK(); 1413 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1414 unp = LIST_NEXT(unp, unp_link)) { 1415 UNP_PCB_LOCK(unp); 1416 if (unp->unp_gencnt <= gencnt) { 1417 if (cr_cansee(req->td->td_ucred, 1418 unp->unp_socket->so_cred)) { 1419 UNP_PCB_UNLOCK(unp); 1420 continue; 1421 } 1422 unp_list[i++] = unp; 1423 unp->unp_refcount++; 1424 } 1425 UNP_PCB_UNLOCK(unp); 1426 } 1427 UNP_LIST_UNLOCK(); 1428 n = i; /* In case we lost some during malloc. */ 1429 1430 error = 0; 1431 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1432 for (i = 0; i < n; i++) { 1433 unp = unp_list[i]; 1434 UNP_PCB_LOCK(unp); 1435 unp->unp_refcount--; 1436 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) { 1437 xu->xu_len = sizeof *xu; 1438 xu->xu_unpp = unp; 1439 /* 1440 * XXX - need more locking here to protect against 1441 * connect/disconnect races for SMP. 1442 */ 1443 if (unp->unp_addr != NULL) 1444 bcopy(unp->unp_addr, &xu->xu_addr, 1445 unp->unp_addr->sun_len); 1446 if (unp->unp_conn != NULL && 1447 unp->unp_conn->unp_addr != NULL) 1448 bcopy(unp->unp_conn->unp_addr, 1449 &xu->xu_caddr, 1450 unp->unp_conn->unp_addr->sun_len); 1451 bcopy(unp, &xu->xu_unp, sizeof *unp); 1452 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1453 UNP_PCB_UNLOCK(unp); 1454 error = SYSCTL_OUT(req, xu, sizeof *xu); 1455 } else { 1456 freeunp = (unp->unp_refcount == 0); 1457 UNP_PCB_UNLOCK(unp); 1458 if (freeunp) { 1459 UNP_PCB_LOCK_DESTROY(unp); 1460 uma_zfree(unp_zone, unp); 1461 } 1462 } 1463 } 1464 free(xu, M_TEMP); 1465 if (!error) { 1466 /* 1467 * Give the user an updated idea of our state. If the 1468 * generation differs from what we told her before, she knows 1469 * that something happened while we were processing this 1470 * request, and it might be necessary to retry. 1471 */ 1472 xug->xug_gen = unp_gencnt; 1473 xug->xug_sogen = so_gencnt; 1474 xug->xug_count = unp_count; 1475 error = SYSCTL_OUT(req, xug, sizeof *xug); 1476 } 1477 free(unp_list, M_TEMP); 1478 free(xug, M_TEMP); 1479 return (error); 1480 } 1481 1482 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 1483 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1484 "List of active local datagram sockets"); 1485 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 1486 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1487 "List of active local stream sockets"); 1488 1489 static void 1490 unp_shutdown(struct unpcb *unp) 1491 { 1492 struct unpcb *unp2; 1493 struct socket *so; 1494 1495 UNP_LINK_WLOCK_ASSERT(); 1496 UNP_PCB_LOCK_ASSERT(unp); 1497 1498 unp2 = unp->unp_conn; 1499 if (unp->unp_socket->so_type == SOCK_STREAM && unp2 != NULL) { 1500 so = unp2->unp_socket; 1501 if (so != NULL) 1502 socantrcvmore(so); 1503 } 1504 } 1505 1506 static void 1507 unp_drop(struct unpcb *unp, int errno) 1508 { 1509 struct socket *so = unp->unp_socket; 1510 struct unpcb *unp2; 1511 1512 UNP_LINK_WLOCK_ASSERT(); 1513 UNP_PCB_LOCK_ASSERT(unp); 1514 1515 so->so_error = errno; 1516 unp2 = unp->unp_conn; 1517 if (unp2 == NULL) 1518 return; 1519 UNP_PCB_LOCK(unp2); 1520 unp_disconnect(unp, unp2); 1521 UNP_PCB_UNLOCK(unp2); 1522 } 1523 1524 static void 1525 unp_freerights(struct file **rp, int fdcount) 1526 { 1527 int i; 1528 struct file *fp; 1529 1530 for (i = 0; i < fdcount; i++) { 1531 fp = *rp; 1532 *rp++ = NULL; 1533 unp_discard(fp); 1534 } 1535 } 1536 1537 static int 1538 unp_externalize(struct mbuf *control, struct mbuf **controlp) 1539 { 1540 struct thread *td = curthread; /* XXX */ 1541 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1542 int i; 1543 int *fdp; 1544 struct file **rp; 1545 struct file *fp; 1546 void *data; 1547 socklen_t clen = control->m_len, datalen; 1548 int error, newfds; 1549 int f; 1550 u_int newlen; 1551 1552 UNP_LINK_UNLOCK_ASSERT(); 1553 1554 error = 0; 1555 if (controlp != NULL) /* controlp == NULL => free control messages */ 1556 *controlp = NULL; 1557 while (cm != NULL) { 1558 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1559 error = EINVAL; 1560 break; 1561 } 1562 data = CMSG_DATA(cm); 1563 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1564 if (cm->cmsg_level == SOL_SOCKET 1565 && cm->cmsg_type == SCM_RIGHTS) { 1566 newfds = datalen / sizeof(struct file *); 1567 rp = data; 1568 1569 /* If we're not outputting the descriptors free them. */ 1570 if (error || controlp == NULL) { 1571 unp_freerights(rp, newfds); 1572 goto next; 1573 } 1574 FILEDESC_XLOCK(td->td_proc->p_fd); 1575 /* if the new FD's will not fit free them. */ 1576 if (!fdavail(td, newfds)) { 1577 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1578 error = EMSGSIZE; 1579 unp_freerights(rp, newfds); 1580 goto next; 1581 } 1582 1583 /* 1584 * Now change each pointer to an fd in the global 1585 * table to an integer that is the index to the local 1586 * fd table entry that we set up to point to the 1587 * global one we are transferring. 1588 */ 1589 newlen = newfds * sizeof(int); 1590 *controlp = sbcreatecontrol(NULL, newlen, 1591 SCM_RIGHTS, SOL_SOCKET); 1592 if (*controlp == NULL) { 1593 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1594 error = E2BIG; 1595 unp_freerights(rp, newfds); 1596 goto next; 1597 } 1598 1599 fdp = (int *) 1600 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1601 for (i = 0; i < newfds; i++) { 1602 if (fdalloc(td, 0, &f)) 1603 panic("unp_externalize fdalloc failed"); 1604 fp = *rp++; 1605 td->td_proc->p_fd->fd_ofiles[f] = fp; 1606 unp_externalize_fp(fp); 1607 *fdp++ = f; 1608 } 1609 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1610 } else { 1611 /* We can just copy anything else across. */ 1612 if (error || controlp == NULL) 1613 goto next; 1614 *controlp = sbcreatecontrol(NULL, datalen, 1615 cm->cmsg_type, cm->cmsg_level); 1616 if (*controlp == NULL) { 1617 error = ENOBUFS; 1618 goto next; 1619 } 1620 bcopy(data, 1621 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1622 datalen); 1623 } 1624 controlp = &(*controlp)->m_next; 1625 1626 next: 1627 if (CMSG_SPACE(datalen) < clen) { 1628 clen -= CMSG_SPACE(datalen); 1629 cm = (struct cmsghdr *) 1630 ((caddr_t)cm + CMSG_SPACE(datalen)); 1631 } else { 1632 clen = 0; 1633 cm = NULL; 1634 } 1635 } 1636 1637 m_freem(control); 1638 return (error); 1639 } 1640 1641 static void 1642 unp_zone_change(void *tag) 1643 { 1644 1645 uma_zone_set_max(unp_zone, maxsockets); 1646 } 1647 1648 static void 1649 unp_init(void) 1650 { 1651 1652 #ifdef VIMAGE 1653 if (!IS_DEFAULT_VNET(curvnet)) 1654 return; 1655 #endif 1656 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1657 NULL, NULL, UMA_ALIGN_PTR, 0); 1658 if (unp_zone == NULL) 1659 panic("unp_init"); 1660 uma_zone_set_max(unp_zone, maxsockets); 1661 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 1662 NULL, EVENTHANDLER_PRI_ANY); 1663 LIST_INIT(&unp_dhead); 1664 LIST_INIT(&unp_shead); 1665 TASK_INIT(&unp_gc_task, 0, unp_gc, NULL); 1666 UNP_LINK_LOCK_INIT(); 1667 UNP_LIST_LOCK_INIT(); 1668 } 1669 1670 static int 1671 unp_internalize(struct mbuf **controlp, struct thread *td) 1672 { 1673 struct mbuf *control = *controlp; 1674 struct proc *p = td->td_proc; 1675 struct filedesc *fdescp = p->p_fd; 1676 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1677 struct cmsgcred *cmcred; 1678 struct file **rp; 1679 struct file *fp; 1680 struct timeval *tv; 1681 int i, fd, *fdp; 1682 void *data; 1683 socklen_t clen = control->m_len, datalen; 1684 int error, oldfds; 1685 u_int newlen; 1686 1687 UNP_LINK_UNLOCK_ASSERT(); 1688 1689 error = 0; 1690 *controlp = NULL; 1691 while (cm != NULL) { 1692 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1693 || cm->cmsg_len > clen) { 1694 error = EINVAL; 1695 goto out; 1696 } 1697 data = CMSG_DATA(cm); 1698 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1699 1700 switch (cm->cmsg_type) { 1701 /* 1702 * Fill in credential information. 1703 */ 1704 case SCM_CREDS: 1705 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1706 SCM_CREDS, SOL_SOCKET); 1707 if (*controlp == NULL) { 1708 error = ENOBUFS; 1709 goto out; 1710 } 1711 cmcred = (struct cmsgcred *) 1712 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1713 cmcred->cmcred_pid = p->p_pid; 1714 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1715 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1716 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1717 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1718 CMGROUP_MAX); 1719 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1720 cmcred->cmcred_groups[i] = 1721 td->td_ucred->cr_groups[i]; 1722 break; 1723 1724 case SCM_RIGHTS: 1725 oldfds = datalen / sizeof (int); 1726 /* 1727 * Check that all the FDs passed in refer to legal 1728 * files. If not, reject the entire operation. 1729 */ 1730 fdp = data; 1731 FILEDESC_SLOCK(fdescp); 1732 for (i = 0; i < oldfds; i++) { 1733 fd = *fdp++; 1734 if ((unsigned)fd >= fdescp->fd_nfiles || 1735 fdescp->fd_ofiles[fd] == NULL) { 1736 FILEDESC_SUNLOCK(fdescp); 1737 error = EBADF; 1738 goto out; 1739 } 1740 fp = fdescp->fd_ofiles[fd]; 1741 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1742 FILEDESC_SUNLOCK(fdescp); 1743 error = EOPNOTSUPP; 1744 goto out; 1745 } 1746 1747 } 1748 1749 /* 1750 * Now replace the integer FDs with pointers to the 1751 * associated global file table entry.. 1752 */ 1753 newlen = oldfds * sizeof(struct file *); 1754 *controlp = sbcreatecontrol(NULL, newlen, 1755 SCM_RIGHTS, SOL_SOCKET); 1756 if (*controlp == NULL) { 1757 FILEDESC_SUNLOCK(fdescp); 1758 error = E2BIG; 1759 goto out; 1760 } 1761 fdp = data; 1762 rp = (struct file **) 1763 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1764 for (i = 0; i < oldfds; i++) { 1765 fp = fdescp->fd_ofiles[*fdp++]; 1766 *rp++ = fp; 1767 unp_internalize_fp(fp); 1768 } 1769 FILEDESC_SUNLOCK(fdescp); 1770 break; 1771 1772 case SCM_TIMESTAMP: 1773 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1774 SCM_TIMESTAMP, SOL_SOCKET); 1775 if (*controlp == NULL) { 1776 error = ENOBUFS; 1777 goto out; 1778 } 1779 tv = (struct timeval *) 1780 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1781 microtime(tv); 1782 break; 1783 1784 default: 1785 error = EINVAL; 1786 goto out; 1787 } 1788 1789 controlp = &(*controlp)->m_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 out: 1801 m_freem(control); 1802 return (error); 1803 } 1804 1805 static struct mbuf * 1806 unp_addsockcred(struct thread *td, struct mbuf *control) 1807 { 1808 struct mbuf *m, *n, *n_prev; 1809 struct sockcred *sc; 1810 const struct cmsghdr *cm; 1811 int ngroups; 1812 int i; 1813 1814 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 1815 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 1816 if (m == NULL) 1817 return (control); 1818 1819 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 1820 sc->sc_uid = td->td_ucred->cr_ruid; 1821 sc->sc_euid = td->td_ucred->cr_uid; 1822 sc->sc_gid = td->td_ucred->cr_rgid; 1823 sc->sc_egid = td->td_ucred->cr_gid; 1824 sc->sc_ngroups = ngroups; 1825 for (i = 0; i < sc->sc_ngroups; i++) 1826 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 1827 1828 /* 1829 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 1830 * created SCM_CREDS control message (struct sockcred) has another 1831 * format. 1832 */ 1833 if (control != NULL) 1834 for (n = control, n_prev = NULL; n != NULL;) { 1835 cm = mtod(n, struct cmsghdr *); 1836 if (cm->cmsg_level == SOL_SOCKET && 1837 cm->cmsg_type == SCM_CREDS) { 1838 if (n_prev == NULL) 1839 control = n->m_next; 1840 else 1841 n_prev->m_next = n->m_next; 1842 n = m_free(n); 1843 } else { 1844 n_prev = n; 1845 n = n->m_next; 1846 } 1847 } 1848 1849 /* Prepend it to the head. */ 1850 m->m_next = control; 1851 return (m); 1852 } 1853 1854 static struct unpcb * 1855 fptounp(struct file *fp) 1856 { 1857 struct socket *so; 1858 1859 if (fp->f_type != DTYPE_SOCKET) 1860 return (NULL); 1861 if ((so = fp->f_data) == NULL) 1862 return (NULL); 1863 if (so->so_proto->pr_domain != &localdomain) 1864 return (NULL); 1865 return sotounpcb(so); 1866 } 1867 1868 static void 1869 unp_discard(struct file *fp) 1870 { 1871 1872 unp_externalize_fp(fp); 1873 (void) closef(fp, (struct thread *)NULL); 1874 } 1875 1876 static void 1877 unp_internalize_fp(struct file *fp) 1878 { 1879 struct unpcb *unp; 1880 1881 UNP_LINK_WLOCK(); 1882 if ((unp = fptounp(fp)) != NULL) { 1883 unp->unp_file = fp; 1884 unp->unp_msgcount++; 1885 } 1886 fhold(fp); 1887 unp_rights++; 1888 UNP_LINK_WUNLOCK(); 1889 } 1890 1891 static void 1892 unp_externalize_fp(struct file *fp) 1893 { 1894 struct unpcb *unp; 1895 1896 UNP_LINK_WLOCK(); 1897 if ((unp = fptounp(fp)) != NULL) 1898 unp->unp_msgcount--; 1899 unp_rights--; 1900 UNP_LINK_WUNLOCK(); 1901 } 1902 1903 /* 1904 * unp_defer indicates whether additional work has been defered for a future 1905 * pass through unp_gc(). It is thread local and does not require explicit 1906 * synchronization. 1907 */ 1908 static int unp_marked; 1909 static int unp_unreachable; 1910 1911 static void 1912 unp_accessable(struct file *fp) 1913 { 1914 struct unpcb *unp; 1915 1916 if ((unp = fptounp(fp)) == NULL) 1917 return; 1918 if (unp->unp_gcflag & UNPGC_REF) 1919 return; 1920 unp->unp_gcflag &= ~UNPGC_DEAD; 1921 unp->unp_gcflag |= UNPGC_REF; 1922 unp_marked++; 1923 } 1924 1925 static void 1926 unp_gc_process(struct unpcb *unp) 1927 { 1928 struct socket *soa; 1929 struct socket *so; 1930 struct file *fp; 1931 1932 /* Already processed. */ 1933 if (unp->unp_gcflag & UNPGC_SCANNED) 1934 return; 1935 fp = unp->unp_file; 1936 1937 /* 1938 * Check for a socket potentially in a cycle. It must be in a 1939 * queue as indicated by msgcount, and this must equal the file 1940 * reference count. Note that when msgcount is 0 the file is NULL. 1941 */ 1942 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 1943 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 1944 unp->unp_gcflag |= UNPGC_DEAD; 1945 unp_unreachable++; 1946 return; 1947 } 1948 1949 /* 1950 * Mark all sockets we reference with RIGHTS. 1951 */ 1952 so = unp->unp_socket; 1953 SOCKBUF_LOCK(&so->so_rcv); 1954 unp_scan(so->so_rcv.sb_mb, unp_accessable); 1955 SOCKBUF_UNLOCK(&so->so_rcv); 1956 1957 /* 1958 * Mark all sockets in our accept queue. 1959 */ 1960 ACCEPT_LOCK(); 1961 TAILQ_FOREACH(soa, &so->so_comp, so_list) { 1962 SOCKBUF_LOCK(&soa->so_rcv); 1963 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 1964 SOCKBUF_UNLOCK(&soa->so_rcv); 1965 } 1966 ACCEPT_UNLOCK(); 1967 unp->unp_gcflag |= UNPGC_SCANNED; 1968 } 1969 1970 static int unp_recycled; 1971 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 1972 "Number of unreachable sockets claimed by the garbage collector."); 1973 1974 static int unp_taskcount; 1975 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 1976 "Number of times the garbage collector has run."); 1977 1978 static void 1979 unp_gc(__unused void *arg, int pending) 1980 { 1981 struct unp_head *heads[] = { &unp_dhead, &unp_shead, NULL }; 1982 struct unp_head **head; 1983 struct file **unref; 1984 struct unpcb *unp; 1985 int i; 1986 1987 unp_taskcount++; 1988 UNP_LIST_LOCK(); 1989 /* 1990 * First clear all gc flags from previous runs. 1991 */ 1992 for (head = heads; *head != NULL; head++) 1993 LIST_FOREACH(unp, *head, unp_link) 1994 unp->unp_gcflag = 0; 1995 1996 /* 1997 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 1998 * is reachable all of the sockets it references are reachable. 1999 * Stop the scan once we do a complete loop without discovering 2000 * a new reachable socket. 2001 */ 2002 do { 2003 unp_unreachable = 0; 2004 unp_marked = 0; 2005 for (head = heads; *head != NULL; head++) 2006 LIST_FOREACH(unp, *head, unp_link) 2007 unp_gc_process(unp); 2008 } while (unp_marked); 2009 UNP_LIST_UNLOCK(); 2010 if (unp_unreachable == 0) 2011 return; 2012 2013 /* 2014 * Allocate space for a local list of dead unpcbs. 2015 */ 2016 unref = malloc(unp_unreachable * sizeof(struct file *), 2017 M_TEMP, M_WAITOK); 2018 2019 /* 2020 * Iterate looking for sockets which have been specifically marked 2021 * as as unreachable and store them locally. 2022 */ 2023 UNP_LIST_LOCK(); 2024 for (i = 0, head = heads; *head != NULL; head++) 2025 LIST_FOREACH(unp, *head, unp_link) 2026 if (unp->unp_gcflag & UNPGC_DEAD) { 2027 unref[i++] = unp->unp_file; 2028 fhold(unp->unp_file); 2029 KASSERT(unp->unp_file != NULL, 2030 ("unp_gc: Invalid unpcb.")); 2031 KASSERT(i <= unp_unreachable, 2032 ("unp_gc: incorrect unreachable count.")); 2033 } 2034 UNP_LIST_UNLOCK(); 2035 2036 /* 2037 * Now flush all sockets, free'ing rights. This will free the 2038 * struct files associated with these sockets but leave each socket 2039 * with one remaining ref. 2040 */ 2041 for (i = 0; i < unp_unreachable; i++) 2042 sorflush(unref[i]->f_data); 2043 2044 /* 2045 * And finally release the sockets so they can be reclaimed. 2046 */ 2047 for (i = 0; i < unp_unreachable; i++) 2048 fdrop(unref[i], NULL); 2049 unp_recycled += unp_unreachable; 2050 free(unref, M_TEMP); 2051 } 2052 2053 static void 2054 unp_dispose(struct mbuf *m) 2055 { 2056 2057 if (m) 2058 unp_scan(m, unp_discard); 2059 } 2060 2061 static void 2062 unp_scan(struct mbuf *m0, void (*op)(struct file *)) 2063 { 2064 struct mbuf *m; 2065 struct file **rp; 2066 struct cmsghdr *cm; 2067 void *data; 2068 int i; 2069 socklen_t clen, datalen; 2070 int qfds; 2071 2072 while (m0 != NULL) { 2073 for (m = m0; m; m = m->m_next) { 2074 if (m->m_type != MT_CONTROL) 2075 continue; 2076 2077 cm = mtod(m, struct cmsghdr *); 2078 clen = m->m_len; 2079 2080 while (cm != NULL) { 2081 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2082 break; 2083 2084 data = CMSG_DATA(cm); 2085 datalen = (caddr_t)cm + cm->cmsg_len 2086 - (caddr_t)data; 2087 2088 if (cm->cmsg_level == SOL_SOCKET && 2089 cm->cmsg_type == SCM_RIGHTS) { 2090 qfds = datalen / sizeof (struct file *); 2091 rp = data; 2092 for (i = 0; i < qfds; i++) 2093 (*op)(*rp++); 2094 } 2095 2096 if (CMSG_SPACE(datalen) < clen) { 2097 clen -= CMSG_SPACE(datalen); 2098 cm = (struct cmsghdr *) 2099 ((caddr_t)cm + CMSG_SPACE(datalen)); 2100 } else { 2101 clen = 0; 2102 cm = NULL; 2103 } 2104 } 2105 } 2106 m0 = m0->m_act; 2107 } 2108 } 2109 2110 #ifdef DDB 2111 static void 2112 db_print_indent(int indent) 2113 { 2114 int i; 2115 2116 for (i = 0; i < indent; i++) 2117 db_printf(" "); 2118 } 2119 2120 static void 2121 db_print_unpflags(int unp_flags) 2122 { 2123 int comma; 2124 2125 comma = 0; 2126 if (unp_flags & UNP_HAVEPC) { 2127 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2128 comma = 1; 2129 } 2130 if (unp_flags & UNP_HAVEPCCACHED) { 2131 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : ""); 2132 comma = 1; 2133 } 2134 if (unp_flags & UNP_WANTCRED) { 2135 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2136 comma = 1; 2137 } 2138 if (unp_flags & UNP_CONNWAIT) { 2139 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2140 comma = 1; 2141 } 2142 if (unp_flags & UNP_CONNECTING) { 2143 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2144 comma = 1; 2145 } 2146 if (unp_flags & UNP_BINDING) { 2147 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2148 comma = 1; 2149 } 2150 } 2151 2152 static void 2153 db_print_xucred(int indent, struct xucred *xu) 2154 { 2155 int comma, i; 2156 2157 db_print_indent(indent); 2158 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2159 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2160 db_print_indent(indent); 2161 db_printf("cr_groups: "); 2162 comma = 0; 2163 for (i = 0; i < xu->cr_ngroups; i++) { 2164 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2165 comma = 1; 2166 } 2167 db_printf("\n"); 2168 } 2169 2170 static void 2171 db_print_unprefs(int indent, struct unp_head *uh) 2172 { 2173 struct unpcb *unp; 2174 int counter; 2175 2176 counter = 0; 2177 LIST_FOREACH(unp, uh, unp_reflink) { 2178 if (counter % 4 == 0) 2179 db_print_indent(indent); 2180 db_printf("%p ", unp); 2181 if (counter % 4 == 3) 2182 db_printf("\n"); 2183 counter++; 2184 } 2185 if (counter != 0 && counter % 4 != 0) 2186 db_printf("\n"); 2187 } 2188 2189 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2190 { 2191 struct unpcb *unp; 2192 2193 if (!have_addr) { 2194 db_printf("usage: show unpcb <addr>\n"); 2195 return; 2196 } 2197 unp = (struct unpcb *)addr; 2198 2199 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2200 unp->unp_vnode); 2201 2202 db_printf("unp_ino: %d unp_conn: %p\n", unp->unp_ino, 2203 unp->unp_conn); 2204 2205 db_printf("unp_refs:\n"); 2206 db_print_unprefs(2, &unp->unp_refs); 2207 2208 /* XXXRW: Would be nice to print the full address, if any. */ 2209 db_printf("unp_addr: %p\n", unp->unp_addr); 2210 2211 db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n", 2212 unp->unp_cc, unp->unp_mbcnt, 2213 (unsigned long long)unp->unp_gencnt); 2214 2215 db_printf("unp_flags: %x (", unp->unp_flags); 2216 db_print_unpflags(unp->unp_flags); 2217 db_printf(")\n"); 2218 2219 db_printf("unp_peercred:\n"); 2220 db_print_xucred(2, &unp->unp_peercred); 2221 2222 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2223 } 2224 #endif
Cache object: 641463c9fb53b2e0bb768c60eca7458f
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