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 * 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/8.4/sys/kern/uipc_usrreq.c 233802 2012-04-02 18:54:10Z trociny $"); 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/queue.h> 79 #include <sys/resourcevar.h> 80 #include <sys/rwlock.h> 81 #include <sys/socket.h> 82 #include <sys/socketvar.h> 83 #include <sys/signalvar.h> 84 #include <sys/stat.h> 85 #include <sys/sx.h> 86 #include <sys/sysctl.h> 87 #include <sys/systm.h> 88 #include <sys/taskqueue.h> 89 #include <sys/un.h> 90 #include <sys/unpcb.h> 91 #include <sys/vnode.h> 92 93 #include <net/vnet.h> 94 95 #ifdef DDB 96 #include <ddb/ddb.h> 97 #endif 98 99 #include <security/mac/mac_framework.h> 100 101 #include <vm/uma.h> 102 103 /* 104 * Locking key: 105 * (l) Locked using list lock 106 * (g) Locked using linkage lock 107 */ 108 109 static uma_zone_t unp_zone; 110 static unp_gen_t unp_gencnt; /* (l) */ 111 static u_int unp_count; /* (l) Count of local sockets. */ 112 static ino_t unp_ino; /* Prototype for fake inode numbers. */ 113 static int unp_rights; /* (g) File descriptors in flight. */ 114 static struct unp_head unp_shead; /* (l) List of stream sockets. */ 115 static struct unp_head unp_dhead; /* (l) List of datagram sockets. */ 116 117 struct unp_defer { 118 SLIST_ENTRY(unp_defer) ud_link; 119 struct file *ud_fp; 120 }; 121 static SLIST_HEAD(, unp_defer) unp_defers; 122 static int unp_defers_count; 123 124 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 125 126 /* 127 * Garbage collection of cyclic file descriptor/socket references occurs 128 * asynchronously in a taskqueue context in order to avoid recursion and 129 * reentrance in the UNIX domain socket, file descriptor, and socket layer 130 * code. See unp_gc() for a full description. 131 */ 132 static struct task unp_gc_task; 133 134 /* 135 * The close of unix domain sockets attached as SCM_RIGHTS is 136 * postponed to the taskqueue, to avoid arbitrary recursion depth. 137 * The attached sockets might have another sockets attached. 138 */ 139 static struct task unp_defer_task; 140 141 /* 142 * Both send and receive buffers are allocated PIPSIZ bytes of buffering for 143 * stream sockets, although the total for sender and receiver is actually 144 * only PIPSIZ. 145 * 146 * Datagram sockets really use the sendspace as the maximum datagram size, 147 * and don't really want to reserve the sendspace. Their recvspace should be 148 * large enough for at least one max-size datagram plus address. 149 */ 150 #ifndef PIPSIZ 151 #define PIPSIZ 8192 152 #endif 153 static u_long unpst_sendspace = PIPSIZ; 154 static u_long unpst_recvspace = PIPSIZ; 155 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 156 static u_long unpdg_recvspace = 4*1024; 157 158 SYSCTL_NODE(_net, PF_LOCAL, local, CTLFLAG_RW, 0, "Local domain"); 159 SYSCTL_NODE(_net_local, SOCK_STREAM, stream, CTLFLAG_RW, 0, "SOCK_STREAM"); 160 SYSCTL_NODE(_net_local, SOCK_DGRAM, dgram, CTLFLAG_RW, 0, "SOCK_DGRAM"); 161 162 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 163 &unpst_sendspace, 0, "Default stream send space."); 164 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 165 &unpst_recvspace, 0, "Default stream receive space."); 166 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 167 &unpdg_sendspace, 0, "Default datagram send space."); 168 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 169 &unpdg_recvspace, 0, "Default datagram receive space."); 170 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 171 "File descriptors in flight."); 172 SYSCTL_INT(_net_local, OID_AUTO, deferred, CTLFLAG_RD, 173 &unp_defers_count, 0, 174 "File descriptors deferred to taskqueue for close."); 175 176 /*- 177 * Locking and synchronization: 178 * 179 * Three types of locks exit in the local domain socket implementation: a 180 * global list mutex, a global linkage rwlock, and per-unpcb mutexes. Of the 181 * global locks, the list lock protects the socket count, global generation 182 * number, and stream/datagram global lists. The linkage lock protects the 183 * interconnection of unpcbs, the v_socket and unp_vnode pointers, and can be 184 * held exclusively over the acquisition of multiple unpcb locks to prevent 185 * deadlock. 186 * 187 * UNIX domain sockets each have an unpcb hung off of their so_pcb pointer, 188 * allocated in pru_attach() and freed in pru_detach(). The validity of that 189 * pointer is an invariant, so no lock is required to dereference the so_pcb 190 * pointer if a valid socket reference is held by the caller. In practice, 191 * this is always true during operations performed on a socket. Each unpcb 192 * has a back-pointer to its socket, unp_socket, which will be stable under 193 * the same circumstances. 194 * 195 * This pointer may only be safely dereferenced as long as a valid reference 196 * to the unpcb is held. Typically, this reference will be from the socket, 197 * or from another unpcb when the referring unpcb's lock is held (in order 198 * that the reference not be invalidated during use). For example, to follow 199 * unp->unp_conn->unp_socket, you need unlock the lock on unp, not unp_conn, 200 * as unp_socket remains valid as long as the reference to unp_conn is valid. 201 * 202 * Fields of unpcbss are locked using a per-unpcb lock, unp_mtx. Individual 203 * atomic reads without the lock may be performed "lockless", but more 204 * complex reads and read-modify-writes require the mutex to be held. No 205 * lock order is defined between unpcb locks -- multiple unpcb locks may be 206 * acquired at the same time only when holding the linkage rwlock 207 * exclusively, which prevents deadlocks. 208 * 209 * Blocking with UNIX domain sockets is a tricky issue: unlike most network 210 * protocols, bind() is a non-atomic operation, and connect() requires 211 * potential sleeping in the protocol, due to potentially waiting on local or 212 * distributed file systems. We try to separate "lookup" operations, which 213 * may sleep, and the IPC operations themselves, which typically can occur 214 * with relative atomicity as locks can be held over the entire operation. 215 * 216 * Another tricky issue is simultaneous multi-threaded or multi-process 217 * access to a single UNIX domain socket. These are handled by the flags 218 * UNP_CONNECTING and UNP_BINDING, which prevent concurrent connecting or 219 * binding, both of which involve dropping UNIX domain socket locks in order 220 * to perform namei() and other file system operations. 221 */ 222 static struct rwlock unp_link_rwlock; 223 static struct mtx unp_list_lock; 224 static struct mtx unp_defers_lock; 225 226 #define UNP_LINK_LOCK_INIT() rw_init(&unp_link_rwlock, \ 227 "unp_link_rwlock") 228 229 #define UNP_LINK_LOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 230 RA_LOCKED) 231 #define UNP_LINK_UNLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 232 RA_UNLOCKED) 233 234 #define UNP_LINK_RLOCK() rw_rlock(&unp_link_rwlock) 235 #define UNP_LINK_RUNLOCK() rw_runlock(&unp_link_rwlock) 236 #define UNP_LINK_WLOCK() rw_wlock(&unp_link_rwlock) 237 #define UNP_LINK_WUNLOCK() rw_wunlock(&unp_link_rwlock) 238 #define UNP_LINK_WLOCK_ASSERT() rw_assert(&unp_link_rwlock, \ 239 RA_WLOCKED) 240 241 #define UNP_LIST_LOCK_INIT() mtx_init(&unp_list_lock, \ 242 "unp_list_lock", NULL, MTX_DEF) 243 #define UNP_LIST_LOCK() mtx_lock(&unp_list_lock) 244 #define UNP_LIST_UNLOCK() mtx_unlock(&unp_list_lock) 245 246 #define UNP_DEFERRED_LOCK_INIT() mtx_init(&unp_defers_lock, \ 247 "unp_defer", NULL, MTX_DEF) 248 #define UNP_DEFERRED_LOCK() mtx_lock(&unp_defers_lock) 249 #define UNP_DEFERRED_UNLOCK() mtx_unlock(&unp_defers_lock) 250 251 #define UNP_PCB_LOCK_INIT(unp) mtx_init(&(unp)->unp_mtx, \ 252 "unp_mtx", "unp_mtx", \ 253 MTX_DUPOK|MTX_DEF|MTX_RECURSE) 254 #define UNP_PCB_LOCK_DESTROY(unp) mtx_destroy(&(unp)->unp_mtx) 255 #define UNP_PCB_LOCK(unp) mtx_lock(&(unp)->unp_mtx) 256 #define UNP_PCB_UNLOCK(unp) mtx_unlock(&(unp)->unp_mtx) 257 #define UNP_PCB_LOCK_ASSERT(unp) mtx_assert(&(unp)->unp_mtx, MA_OWNED) 258 259 static int uipc_connect2(struct socket *, struct socket *); 260 static int uipc_ctloutput(struct socket *, struct sockopt *); 261 static int unp_connect(struct socket *, struct sockaddr *, 262 struct thread *); 263 static int unp_connect2(struct socket *so, struct socket *so2, int); 264 static void unp_disconnect(struct unpcb *unp, struct unpcb *unp2); 265 static void unp_dispose(struct mbuf *); 266 static void unp_shutdown(struct unpcb *); 267 static void unp_drop(struct unpcb *, int); 268 static void unp_gc(__unused void *, int); 269 static void unp_scan(struct mbuf *, void (*)(struct file *)); 270 static void unp_discard(struct file *); 271 static void unp_freerights(struct file **, int); 272 static void unp_init(void); 273 static int unp_internalize(struct mbuf **, struct thread *); 274 static void unp_internalize_fp(struct file *); 275 static int unp_externalize(struct mbuf *, struct mbuf **); 276 static int unp_externalize_fp(struct file *); 277 static struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 278 static void unp_process_defers(void * __unused, int); 279 280 /* 281 * Definitions of protocols supported in the LOCAL domain. 282 */ 283 static struct domain localdomain; 284 static struct pr_usrreqs uipc_usrreqs_dgram, uipc_usrreqs_stream; 285 static struct protosw localsw[] = { 286 { 287 .pr_type = SOCK_STREAM, 288 .pr_domain = &localdomain, 289 .pr_flags = PR_CONNREQUIRED|PR_WANTRCVD|PR_RIGHTS, 290 .pr_ctloutput = &uipc_ctloutput, 291 .pr_usrreqs = &uipc_usrreqs_stream 292 }, 293 { 294 .pr_type = SOCK_DGRAM, 295 .pr_domain = &localdomain, 296 .pr_flags = PR_ATOMIC|PR_ADDR|PR_RIGHTS, 297 .pr_usrreqs = &uipc_usrreqs_dgram 298 }, 299 }; 300 301 static struct domain localdomain = { 302 .dom_family = AF_LOCAL, 303 .dom_name = "local", 304 .dom_init = unp_init, 305 .dom_externalize = unp_externalize, 306 .dom_dispose = unp_dispose, 307 .dom_protosw = localsw, 308 .dom_protoswNPROTOSW = &localsw[sizeof(localsw)/sizeof(localsw[0])] 309 }; 310 DOMAIN_SET(local); 311 312 static void 313 uipc_abort(struct socket *so) 314 { 315 struct unpcb *unp, *unp2; 316 317 unp = sotounpcb(so); 318 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 319 320 UNP_LINK_WLOCK(); 321 UNP_PCB_LOCK(unp); 322 unp2 = unp->unp_conn; 323 if (unp2 != NULL) { 324 UNP_PCB_LOCK(unp2); 325 unp_drop(unp2, ECONNABORTED); 326 UNP_PCB_UNLOCK(unp2); 327 } 328 UNP_PCB_UNLOCK(unp); 329 UNP_LINK_WUNLOCK(); 330 } 331 332 static int 333 uipc_accept(struct socket *so, struct sockaddr **nam) 334 { 335 struct unpcb *unp, *unp2; 336 const struct sockaddr *sa; 337 338 /* 339 * Pass back name of connected socket, if it was bound and we are 340 * still connected (our peer may have closed already!). 341 */ 342 unp = sotounpcb(so); 343 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 344 345 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 346 UNP_LINK_RLOCK(); 347 unp2 = unp->unp_conn; 348 if (unp2 != NULL && unp2->unp_addr != NULL) { 349 UNP_PCB_LOCK(unp2); 350 sa = (struct sockaddr *) unp2->unp_addr; 351 bcopy(sa, *nam, sa->sa_len); 352 UNP_PCB_UNLOCK(unp2); 353 } else { 354 sa = &sun_noname; 355 bcopy(sa, *nam, sa->sa_len); 356 } 357 UNP_LINK_RUNLOCK(); 358 return (0); 359 } 360 361 static int 362 uipc_attach(struct socket *so, int proto, struct thread *td) 363 { 364 u_long sendspace, recvspace; 365 struct unpcb *unp; 366 int error; 367 368 KASSERT(so->so_pcb == NULL, ("uipc_attach: so_pcb != NULL")); 369 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 370 switch (so->so_type) { 371 case SOCK_STREAM: 372 sendspace = unpst_sendspace; 373 recvspace = unpst_recvspace; 374 break; 375 376 case SOCK_DGRAM: 377 sendspace = unpdg_sendspace; 378 recvspace = unpdg_recvspace; 379 break; 380 381 default: 382 panic("uipc_attach"); 383 } 384 error = soreserve(so, sendspace, recvspace); 385 if (error) 386 return (error); 387 } 388 unp = uma_zalloc(unp_zone, M_NOWAIT | M_ZERO); 389 if (unp == NULL) 390 return (ENOBUFS); 391 LIST_INIT(&unp->unp_refs); 392 UNP_PCB_LOCK_INIT(unp); 393 unp->unp_socket = so; 394 so->so_pcb = unp; 395 unp->unp_refcount = 1; 396 397 UNP_LIST_LOCK(); 398 unp->unp_gencnt = ++unp_gencnt; 399 unp_count++; 400 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead : &unp_shead, 401 unp, unp_link); 402 UNP_LIST_UNLOCK(); 403 404 return (0); 405 } 406 407 static int 408 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 409 { 410 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 411 struct vattr vattr; 412 int error, namelen, vfslocked; 413 struct nameidata nd; 414 struct unpcb *unp; 415 struct vnode *vp; 416 struct mount *mp; 417 char *buf; 418 419 unp = sotounpcb(so); 420 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 421 422 if (soun->sun_len > sizeof(struct sockaddr_un)) 423 return (EINVAL); 424 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 425 if (namelen <= 0) 426 return (EINVAL); 427 428 /* 429 * We don't allow simultaneous bind() calls on a single UNIX domain 430 * socket, so flag in-progress operations, and return an error if an 431 * operation is already in progress. 432 * 433 * Historically, we have not allowed a socket to be rebound, so this 434 * also returns an error. Not allowing re-binding simplifies the 435 * implementation and avoids a great many possible failure modes. 436 */ 437 UNP_PCB_LOCK(unp); 438 if (unp->unp_vnode != NULL) { 439 UNP_PCB_UNLOCK(unp); 440 return (EINVAL); 441 } 442 if (unp->unp_flags & UNP_BINDING) { 443 UNP_PCB_UNLOCK(unp); 444 return (EALREADY); 445 } 446 unp->unp_flags |= UNP_BINDING; 447 UNP_PCB_UNLOCK(unp); 448 449 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 450 bcopy(soun->sun_path, buf, namelen); 451 buf[namelen] = 0; 452 453 restart: 454 vfslocked = 0; 455 NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME, 456 UIO_SYSSPACE, buf, td); 457 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 458 error = namei(&nd); 459 if (error) 460 goto error; 461 vp = nd.ni_vp; 462 vfslocked = NDHASGIANT(&nd); 463 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 464 NDFREE(&nd, NDF_ONLY_PNBUF); 465 if (nd.ni_dvp == vp) 466 vrele(nd.ni_dvp); 467 else 468 vput(nd.ni_dvp); 469 if (vp != NULL) { 470 vrele(vp); 471 error = EADDRINUSE; 472 goto error; 473 } 474 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 475 if (error) 476 goto error; 477 VFS_UNLOCK_GIANT(vfslocked); 478 goto restart; 479 } 480 VATTR_NULL(&vattr); 481 vattr.va_type = VSOCK; 482 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 483 #ifdef MAC 484 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 485 &vattr); 486 #endif 487 if (error == 0) 488 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 489 NDFREE(&nd, NDF_ONLY_PNBUF); 490 vput(nd.ni_dvp); 491 if (error) { 492 vn_finished_write(mp); 493 goto error; 494 } 495 vp = nd.ni_vp; 496 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 497 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 498 499 UNP_LINK_WLOCK(); 500 UNP_PCB_LOCK(unp); 501 vp->v_socket = unp->unp_socket; 502 unp->unp_vnode = vp; 503 unp->unp_addr = soun; 504 unp->unp_flags &= ~UNP_BINDING; 505 UNP_PCB_UNLOCK(unp); 506 UNP_LINK_WUNLOCK(); 507 VOP_UNLOCK(vp, 0); 508 vn_finished_write(mp); 509 VFS_UNLOCK_GIANT(vfslocked); 510 free(buf, M_TEMP); 511 return (0); 512 513 error: 514 VFS_UNLOCK_GIANT(vfslocked); 515 UNP_PCB_LOCK(unp); 516 unp->unp_flags &= ~UNP_BINDING; 517 UNP_PCB_UNLOCK(unp); 518 free(buf, M_TEMP); 519 return (error); 520 } 521 522 static int 523 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 524 { 525 int error; 526 527 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 528 UNP_LINK_WLOCK(); 529 error = unp_connect(so, nam, td); 530 UNP_LINK_WUNLOCK(); 531 return (error); 532 } 533 534 static void 535 uipc_close(struct socket *so) 536 { 537 struct unpcb *unp, *unp2; 538 539 unp = sotounpcb(so); 540 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 541 542 UNP_LINK_WLOCK(); 543 UNP_PCB_LOCK(unp); 544 unp2 = unp->unp_conn; 545 if (unp2 != NULL) { 546 UNP_PCB_LOCK(unp2); 547 unp_disconnect(unp, unp2); 548 UNP_PCB_UNLOCK(unp2); 549 } 550 UNP_PCB_UNLOCK(unp); 551 UNP_LINK_WUNLOCK(); 552 } 553 554 static int 555 uipc_connect2(struct socket *so1, struct socket *so2) 556 { 557 struct unpcb *unp, *unp2; 558 int error; 559 560 UNP_LINK_WLOCK(); 561 unp = so1->so_pcb; 562 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 563 UNP_PCB_LOCK(unp); 564 unp2 = so2->so_pcb; 565 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 566 UNP_PCB_LOCK(unp2); 567 error = unp_connect2(so1, so2, PRU_CONNECT2); 568 UNP_PCB_UNLOCK(unp2); 569 UNP_PCB_UNLOCK(unp); 570 UNP_LINK_WUNLOCK(); 571 return (error); 572 } 573 574 static void 575 uipc_detach(struct socket *so) 576 { 577 struct unpcb *unp, *unp2; 578 struct sockaddr_un *saved_unp_addr; 579 struct vnode *vp; 580 int freeunp, local_unp_rights; 581 582 unp = sotounpcb(so); 583 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 584 585 UNP_LINK_WLOCK(); 586 UNP_LIST_LOCK(); 587 UNP_PCB_LOCK(unp); 588 LIST_REMOVE(unp, unp_link); 589 unp->unp_gencnt = ++unp_gencnt; 590 --unp_count; 591 UNP_LIST_UNLOCK(); 592 593 /* 594 * XXXRW: Should assert vp->v_socket == so. 595 */ 596 if ((vp = unp->unp_vnode) != NULL) { 597 unp->unp_vnode->v_socket = NULL; 598 unp->unp_vnode = NULL; 599 } 600 unp2 = unp->unp_conn; 601 if (unp2 != NULL) { 602 UNP_PCB_LOCK(unp2); 603 unp_disconnect(unp, unp2); 604 UNP_PCB_UNLOCK(unp2); 605 } 606 607 /* 608 * We hold the linkage lock exclusively, so it's OK to acquire 609 * multiple pcb locks at a time. 610 */ 611 while (!LIST_EMPTY(&unp->unp_refs)) { 612 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 613 614 UNP_PCB_LOCK(ref); 615 unp_drop(ref, ECONNRESET); 616 UNP_PCB_UNLOCK(ref); 617 } 618 local_unp_rights = unp_rights; 619 UNP_LINK_WUNLOCK(); 620 unp->unp_socket->so_pcb = NULL; 621 saved_unp_addr = unp->unp_addr; 622 unp->unp_addr = NULL; 623 unp->unp_refcount--; 624 freeunp = (unp->unp_refcount == 0); 625 if (saved_unp_addr != NULL) 626 free(saved_unp_addr, M_SONAME); 627 if (freeunp) { 628 UNP_PCB_LOCK_DESTROY(unp); 629 uma_zfree(unp_zone, unp); 630 } else 631 UNP_PCB_UNLOCK(unp); 632 if (vp) { 633 int vfslocked; 634 635 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 636 vrele(vp); 637 VFS_UNLOCK_GIANT(vfslocked); 638 } 639 if (local_unp_rights) 640 taskqueue_enqueue(taskqueue_thread, &unp_gc_task); 641 } 642 643 static int 644 uipc_disconnect(struct socket *so) 645 { 646 struct unpcb *unp, *unp2; 647 648 unp = sotounpcb(so); 649 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 650 651 UNP_LINK_WLOCK(); 652 UNP_PCB_LOCK(unp); 653 unp2 = unp->unp_conn; 654 if (unp2 != NULL) { 655 UNP_PCB_LOCK(unp2); 656 unp_disconnect(unp, unp2); 657 UNP_PCB_UNLOCK(unp2); 658 } 659 UNP_PCB_UNLOCK(unp); 660 UNP_LINK_WUNLOCK(); 661 return (0); 662 } 663 664 static int 665 uipc_listen(struct socket *so, int backlog, struct thread *td) 666 { 667 struct unpcb *unp; 668 int error; 669 670 unp = sotounpcb(so); 671 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 672 673 UNP_PCB_LOCK(unp); 674 if (unp->unp_vnode == NULL) { 675 UNP_PCB_UNLOCK(unp); 676 return (EINVAL); 677 } 678 679 SOCK_LOCK(so); 680 error = solisten_proto_check(so); 681 if (error == 0) { 682 cru2x(td->td_ucred, &unp->unp_peercred); 683 unp->unp_flags |= UNP_HAVEPCCACHED; 684 solisten_proto(so, backlog); 685 } 686 SOCK_UNLOCK(so); 687 UNP_PCB_UNLOCK(unp); 688 return (error); 689 } 690 691 static int 692 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 693 { 694 struct unpcb *unp, *unp2; 695 const struct sockaddr *sa; 696 697 unp = sotounpcb(so); 698 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 699 700 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 701 UNP_LINK_RLOCK(); 702 /* 703 * XXX: It seems that this test always fails even when connection is 704 * established. So, this else clause is added as workaround to 705 * return PF_LOCAL sockaddr. 706 */ 707 unp2 = unp->unp_conn; 708 if (unp2 != NULL) { 709 UNP_PCB_LOCK(unp2); 710 if (unp2->unp_addr != NULL) 711 sa = (struct sockaddr *) unp2->unp_addr; 712 else 713 sa = &sun_noname; 714 bcopy(sa, *nam, sa->sa_len); 715 UNP_PCB_UNLOCK(unp2); 716 } else { 717 sa = &sun_noname; 718 bcopy(sa, *nam, sa->sa_len); 719 } 720 UNP_LINK_RUNLOCK(); 721 return (0); 722 } 723 724 static int 725 uipc_rcvd(struct socket *so, int flags) 726 { 727 struct unpcb *unp, *unp2; 728 struct socket *so2; 729 u_int mbcnt, sbcc; 730 u_long newhiwat; 731 732 unp = sotounpcb(so); 733 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL")); 734 735 if (so->so_type == SOCK_DGRAM) 736 panic("uipc_rcvd DGRAM?"); 737 738 if (so->so_type != SOCK_STREAM) 739 panic("uipc_rcvd unknown socktype"); 740 741 /* 742 * Adjust backpressure on sender and wakeup any waiting to write. 743 * 744 * The unp lock is acquired to maintain the validity of the unp_conn 745 * pointer; no lock on unp2 is required as unp2->unp_socket will be 746 * static as long as we don't permit unp2 to disconnect from unp, 747 * which is prevented by the lock on unp. We cache values from 748 * so_rcv to avoid holding the so_rcv lock over the entire 749 * transaction on the remote so_snd. 750 */ 751 SOCKBUF_LOCK(&so->so_rcv); 752 mbcnt = so->so_rcv.sb_mbcnt; 753 sbcc = so->so_rcv.sb_cc; 754 SOCKBUF_UNLOCK(&so->so_rcv); 755 UNP_PCB_LOCK(unp); 756 unp2 = unp->unp_conn; 757 if (unp2 == NULL) { 758 UNP_PCB_UNLOCK(unp); 759 return (0); 760 } 761 so2 = unp2->unp_socket; 762 SOCKBUF_LOCK(&so2->so_snd); 763 so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt; 764 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc; 765 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, 766 newhiwat, RLIM_INFINITY); 767 sowwakeup_locked(so2); 768 unp->unp_mbcnt = mbcnt; 769 unp->unp_cc = sbcc; 770 UNP_PCB_UNLOCK(unp); 771 return (0); 772 } 773 774 static int 775 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 776 struct mbuf *control, struct thread *td) 777 { 778 struct unpcb *unp, *unp2; 779 struct socket *so2; 780 u_int mbcnt_delta, sbcc; 781 u_int newhiwat; 782 int error = 0; 783 784 unp = sotounpcb(so); 785 KASSERT(unp != NULL, ("uipc_send: unp == NULL")); 786 787 if (flags & PRUS_OOB) { 788 error = EOPNOTSUPP; 789 goto release; 790 } 791 if (control != NULL && (error = unp_internalize(&control, td))) 792 goto release; 793 if ((nam != NULL) || (flags & PRUS_EOF)) 794 UNP_LINK_WLOCK(); 795 else 796 UNP_LINK_RLOCK(); 797 switch (so->so_type) { 798 case SOCK_DGRAM: 799 { 800 const struct sockaddr *from; 801 802 unp2 = unp->unp_conn; 803 if (nam != NULL) { 804 UNP_LINK_WLOCK_ASSERT(); 805 if (unp2 != NULL) { 806 error = EISCONN; 807 break; 808 } 809 error = unp_connect(so, nam, td); 810 if (error) 811 break; 812 unp2 = unp->unp_conn; 813 } 814 815 /* 816 * Because connect() and send() are non-atomic in a sendto() 817 * with a target address, it's possible that the socket will 818 * have disconnected before the send() can run. In that case 819 * return the slightly counter-intuitive but otherwise 820 * correct error that the socket is not connected. 821 */ 822 if (unp2 == NULL) { 823 error = ENOTCONN; 824 break; 825 } 826 /* Lockless read. */ 827 if (unp2->unp_flags & UNP_WANTCRED) 828 control = unp_addsockcred(td, control); 829 UNP_PCB_LOCK(unp); 830 if (unp->unp_addr != NULL) 831 from = (struct sockaddr *)unp->unp_addr; 832 else 833 from = &sun_noname; 834 so2 = unp2->unp_socket; 835 SOCKBUF_LOCK(&so2->so_rcv); 836 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) { 837 sorwakeup_locked(so2); 838 m = NULL; 839 control = NULL; 840 } else { 841 SOCKBUF_UNLOCK(&so2->so_rcv); 842 error = ENOBUFS; 843 } 844 if (nam != NULL) { 845 UNP_LINK_WLOCK_ASSERT(); 846 UNP_PCB_LOCK(unp2); 847 unp_disconnect(unp, unp2); 848 UNP_PCB_UNLOCK(unp2); 849 } 850 UNP_PCB_UNLOCK(unp); 851 break; 852 } 853 854 case SOCK_STREAM: 855 if ((so->so_state & SS_ISCONNECTED) == 0) { 856 if (nam != NULL) { 857 UNP_LINK_WLOCK_ASSERT(); 858 error = unp_connect(so, nam, td); 859 if (error) 860 break; /* XXX */ 861 } else { 862 error = ENOTCONN; 863 break; 864 } 865 } 866 867 /* Lockless read. */ 868 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 869 error = EPIPE; 870 break; 871 } 872 873 /* 874 * Because connect() and send() are non-atomic in a sendto() 875 * with a target address, it's possible that the socket will 876 * have disconnected before the send() can run. In that case 877 * return the slightly counter-intuitive but otherwise 878 * correct error that the socket is not connected. 879 * 880 * Locking here must be done carefully: the linkage lock 881 * prevents interconnections between unpcbs from changing, so 882 * we can traverse from unp to unp2 without acquiring unp's 883 * lock. Socket buffer locks follow unpcb locks, so we can 884 * acquire both remote and lock socket buffer locks. 885 */ 886 unp2 = unp->unp_conn; 887 if (unp2 == NULL) { 888 error = ENOTCONN; 889 break; 890 } 891 so2 = unp2->unp_socket; 892 UNP_PCB_LOCK(unp2); 893 SOCKBUF_LOCK(&so2->so_rcv); 894 if (unp2->unp_flags & UNP_WANTCRED) { 895 /* 896 * Credentials are passed only once on SOCK_STREAM. 897 */ 898 unp2->unp_flags &= ~UNP_WANTCRED; 899 control = unp_addsockcred(td, control); 900 } 901 /* 902 * Send to paired receive port, and then reduce send buffer 903 * hiwater marks to maintain backpressure. Wake up readers. 904 */ 905 if (control != NULL) { 906 if (sbappendcontrol_locked(&so2->so_rcv, m, control)) 907 control = NULL; 908 } else 909 sbappend_locked(&so2->so_rcv, m); 910 mbcnt_delta = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt; 911 unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt; 912 sbcc = so2->so_rcv.sb_cc; 913 sorwakeup_locked(so2); 914 915 SOCKBUF_LOCK(&so->so_snd); 916 if ((int)so->so_snd.sb_hiwat >= (int)(sbcc - unp2->unp_cc)) 917 newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc); 918 else 919 newhiwat = 0; 920 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, 921 newhiwat, RLIM_INFINITY); 922 so->so_snd.sb_mbmax -= mbcnt_delta; 923 SOCKBUF_UNLOCK(&so->so_snd); 924 unp2->unp_cc = sbcc; 925 UNP_PCB_UNLOCK(unp2); 926 m = NULL; 927 break; 928 929 default: 930 panic("uipc_send unknown socktype"); 931 } 932 933 /* 934 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 935 */ 936 if (flags & PRUS_EOF) { 937 UNP_PCB_LOCK(unp); 938 socantsendmore(so); 939 unp_shutdown(unp); 940 UNP_PCB_UNLOCK(unp); 941 } 942 943 if ((nam != NULL) || (flags & PRUS_EOF)) 944 UNP_LINK_WUNLOCK(); 945 else 946 UNP_LINK_RUNLOCK(); 947 948 if (control != NULL && error != 0) 949 unp_dispose(control); 950 951 release: 952 if (control != NULL) 953 m_freem(control); 954 if (m != NULL) 955 m_freem(m); 956 return (error); 957 } 958 959 static int 960 uipc_sense(struct socket *so, struct stat *sb) 961 { 962 struct unpcb *unp, *unp2; 963 struct socket *so2; 964 965 unp = sotounpcb(so); 966 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 967 968 sb->st_blksize = so->so_snd.sb_hiwat; 969 UNP_LINK_RLOCK(); 970 UNP_PCB_LOCK(unp); 971 unp2 = unp->unp_conn; 972 if (so->so_type == SOCK_STREAM && unp2 != NULL) { 973 so2 = unp2->unp_socket; 974 sb->st_blksize += so2->so_rcv.sb_cc; 975 } 976 sb->st_dev = NODEV; 977 if (unp->unp_ino == 0) 978 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 979 sb->st_ino = unp->unp_ino; 980 UNP_PCB_UNLOCK(unp); 981 UNP_LINK_RUNLOCK(); 982 return (0); 983 } 984 985 static int 986 uipc_shutdown(struct socket *so) 987 { 988 struct unpcb *unp; 989 990 unp = sotounpcb(so); 991 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 992 993 UNP_LINK_WLOCK(); 994 UNP_PCB_LOCK(unp); 995 socantsendmore(so); 996 unp_shutdown(unp); 997 UNP_PCB_UNLOCK(unp); 998 UNP_LINK_WUNLOCK(); 999 return (0); 1000 } 1001 1002 static int 1003 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 1004 { 1005 struct unpcb *unp; 1006 const struct sockaddr *sa; 1007 1008 unp = sotounpcb(so); 1009 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 1010 1011 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1012 UNP_PCB_LOCK(unp); 1013 if (unp->unp_addr != NULL) 1014 sa = (struct sockaddr *) unp->unp_addr; 1015 else 1016 sa = &sun_noname; 1017 bcopy(sa, *nam, sa->sa_len); 1018 UNP_PCB_UNLOCK(unp); 1019 return (0); 1020 } 1021 1022 static struct pr_usrreqs uipc_usrreqs_dgram = { 1023 .pru_abort = uipc_abort, 1024 .pru_accept = uipc_accept, 1025 .pru_attach = uipc_attach, 1026 .pru_bind = uipc_bind, 1027 .pru_connect = uipc_connect, 1028 .pru_connect2 = uipc_connect2, 1029 .pru_detach = uipc_detach, 1030 .pru_disconnect = uipc_disconnect, 1031 .pru_listen = uipc_listen, 1032 .pru_peeraddr = uipc_peeraddr, 1033 .pru_rcvd = uipc_rcvd, 1034 .pru_send = uipc_send, 1035 .pru_sense = uipc_sense, 1036 .pru_shutdown = uipc_shutdown, 1037 .pru_sockaddr = uipc_sockaddr, 1038 .pru_soreceive = soreceive_dgram, 1039 .pru_close = uipc_close, 1040 }; 1041 1042 static struct pr_usrreqs uipc_usrreqs_stream = { 1043 .pru_abort = uipc_abort, 1044 .pru_accept = uipc_accept, 1045 .pru_attach = uipc_attach, 1046 .pru_bind = uipc_bind, 1047 .pru_connect = uipc_connect, 1048 .pru_connect2 = uipc_connect2, 1049 .pru_detach = uipc_detach, 1050 .pru_disconnect = uipc_disconnect, 1051 .pru_listen = uipc_listen, 1052 .pru_peeraddr = uipc_peeraddr, 1053 .pru_rcvd = uipc_rcvd, 1054 .pru_send = uipc_send, 1055 .pru_sense = uipc_sense, 1056 .pru_shutdown = uipc_shutdown, 1057 .pru_sockaddr = uipc_sockaddr, 1058 .pru_soreceive = soreceive_generic, 1059 .pru_close = uipc_close, 1060 }; 1061 1062 static int 1063 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1064 { 1065 struct unpcb *unp; 1066 struct xucred xu; 1067 int error, optval; 1068 1069 if (sopt->sopt_level != 0) 1070 return (EINVAL); 1071 1072 unp = sotounpcb(so); 1073 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1074 error = 0; 1075 switch (sopt->sopt_dir) { 1076 case SOPT_GET: 1077 switch (sopt->sopt_name) { 1078 case LOCAL_PEERCRED: 1079 UNP_PCB_LOCK(unp); 1080 if (unp->unp_flags & UNP_HAVEPC) 1081 xu = unp->unp_peercred; 1082 else { 1083 if (so->so_type == SOCK_STREAM) 1084 error = ENOTCONN; 1085 else 1086 error = EINVAL; 1087 } 1088 UNP_PCB_UNLOCK(unp); 1089 if (error == 0) 1090 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1091 break; 1092 1093 case LOCAL_CREDS: 1094 /* Unlocked read. */ 1095 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1096 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1097 break; 1098 1099 case LOCAL_CONNWAIT: 1100 /* Unlocked read. */ 1101 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1102 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1103 break; 1104 1105 default: 1106 error = EOPNOTSUPP; 1107 break; 1108 } 1109 break; 1110 1111 case SOPT_SET: 1112 switch (sopt->sopt_name) { 1113 case LOCAL_CREDS: 1114 case LOCAL_CONNWAIT: 1115 error = sooptcopyin(sopt, &optval, sizeof(optval), 1116 sizeof(optval)); 1117 if (error) 1118 break; 1119 1120 #define OPTSET(bit) do { \ 1121 UNP_PCB_LOCK(unp); \ 1122 if (optval) \ 1123 unp->unp_flags |= bit; \ 1124 else \ 1125 unp->unp_flags &= ~bit; \ 1126 UNP_PCB_UNLOCK(unp); \ 1127 } while (0) 1128 1129 switch (sopt->sopt_name) { 1130 case LOCAL_CREDS: 1131 OPTSET(UNP_WANTCRED); 1132 break; 1133 1134 case LOCAL_CONNWAIT: 1135 OPTSET(UNP_CONNWAIT); 1136 break; 1137 1138 default: 1139 break; 1140 } 1141 break; 1142 #undef OPTSET 1143 default: 1144 error = ENOPROTOOPT; 1145 break; 1146 } 1147 break; 1148 1149 default: 1150 error = EOPNOTSUPP; 1151 break; 1152 } 1153 return (error); 1154 } 1155 1156 static int 1157 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1158 { 1159 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1160 struct vnode *vp; 1161 struct socket *so2, *so3; 1162 struct unpcb *unp, *unp2, *unp3; 1163 int error, len, vfslocked; 1164 struct nameidata nd; 1165 char buf[SOCK_MAXADDRLEN]; 1166 struct sockaddr *sa; 1167 1168 UNP_LINK_WLOCK_ASSERT(); 1169 1170 unp = sotounpcb(so); 1171 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1172 1173 if (nam->sa_len > sizeof(struct sockaddr_un)) 1174 return (EINVAL); 1175 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1176 if (len <= 0) 1177 return (EINVAL); 1178 bcopy(soun->sun_path, buf, len); 1179 buf[len] = 0; 1180 1181 UNP_PCB_LOCK(unp); 1182 if (unp->unp_flags & UNP_CONNECTING) { 1183 UNP_PCB_UNLOCK(unp); 1184 return (EALREADY); 1185 } 1186 UNP_LINK_WUNLOCK(); 1187 unp->unp_flags |= UNP_CONNECTING; 1188 UNP_PCB_UNLOCK(unp); 1189 1190 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1191 NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKSHARED | LOCKLEAF, 1192 UIO_SYSSPACE, buf, td); 1193 error = namei(&nd); 1194 if (error) 1195 vp = NULL; 1196 else 1197 vp = nd.ni_vp; 1198 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1199 vfslocked = NDHASGIANT(&nd); 1200 NDFREE(&nd, NDF_ONLY_PNBUF); 1201 if (error) 1202 goto bad; 1203 1204 if (vp->v_type != VSOCK) { 1205 error = ENOTSOCK; 1206 goto bad; 1207 } 1208 #ifdef MAC 1209 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1210 if (error) 1211 goto bad; 1212 #endif 1213 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1214 if (error) 1215 goto bad; 1216 VFS_UNLOCK_GIANT(vfslocked); 1217 1218 unp = sotounpcb(so); 1219 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1220 1221 /* 1222 * Lock linkage lock for two reasons: make sure v_socket is stable, 1223 * and to protect simultaneous locking of multiple pcbs. 1224 */ 1225 UNP_LINK_WLOCK(); 1226 so2 = vp->v_socket; 1227 if (so2 == NULL) { 1228 error = ECONNREFUSED; 1229 goto bad2; 1230 } 1231 if (so->so_type != so2->so_type) { 1232 error = EPROTOTYPE; 1233 goto bad2; 1234 } 1235 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1236 if (so2->so_options & SO_ACCEPTCONN) { 1237 CURVNET_SET(so2->so_vnet); 1238 so3 = sonewconn(so2, 0); 1239 CURVNET_RESTORE(); 1240 } else 1241 so3 = NULL; 1242 if (so3 == NULL) { 1243 error = ECONNREFUSED; 1244 goto bad2; 1245 } 1246 unp = sotounpcb(so); 1247 unp2 = sotounpcb(so2); 1248 unp3 = sotounpcb(so3); 1249 UNP_PCB_LOCK(unp); 1250 UNP_PCB_LOCK(unp2); 1251 UNP_PCB_LOCK(unp3); 1252 if (unp2->unp_addr != NULL) { 1253 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1254 unp3->unp_addr = (struct sockaddr_un *) sa; 1255 sa = NULL; 1256 } 1257 1258 /* 1259 * The connecter's (client's) credentials are copied from its 1260 * process structure at the time of connect() (which is now). 1261 */ 1262 cru2x(td->td_ucred, &unp3->unp_peercred); 1263 unp3->unp_flags |= UNP_HAVEPC; 1264 1265 /* 1266 * The receiver's (server's) credentials are copied from the 1267 * unp_peercred member of socket on which the former called 1268 * listen(); uipc_listen() cached that process's credentials 1269 * at that time so we can use them now. 1270 */ 1271 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1272 ("unp_connect: listener without cached peercred")); 1273 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1274 sizeof(unp->unp_peercred)); 1275 unp->unp_flags |= UNP_HAVEPC; 1276 if (unp2->unp_flags & UNP_WANTCRED) 1277 unp3->unp_flags |= UNP_WANTCRED; 1278 UNP_PCB_UNLOCK(unp3); 1279 UNP_PCB_UNLOCK(unp2); 1280 UNP_PCB_UNLOCK(unp); 1281 #ifdef MAC 1282 mac_socketpeer_set_from_socket(so, so3); 1283 mac_socketpeer_set_from_socket(so3, so); 1284 #endif 1285 1286 so2 = so3; 1287 } 1288 unp = sotounpcb(so); 1289 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1290 unp2 = sotounpcb(so2); 1291 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL")); 1292 UNP_PCB_LOCK(unp); 1293 UNP_PCB_LOCK(unp2); 1294 error = unp_connect2(so, so2, PRU_CONNECT); 1295 UNP_PCB_UNLOCK(unp2); 1296 UNP_PCB_UNLOCK(unp); 1297 bad2: 1298 UNP_LINK_WUNLOCK(); 1299 if (vfslocked) 1300 /* 1301 * Giant has been previously acquired. This means filesystem 1302 * isn't MPSAFE. Do it once again. 1303 */ 1304 mtx_lock(&Giant); 1305 bad: 1306 if (vp != NULL) 1307 vput(vp); 1308 VFS_UNLOCK_GIANT(vfslocked); 1309 free(sa, M_SONAME); 1310 UNP_LINK_WLOCK(); 1311 UNP_PCB_LOCK(unp); 1312 unp->unp_flags &= ~UNP_CONNECTING; 1313 UNP_PCB_UNLOCK(unp); 1314 return (error); 1315 } 1316 1317 static int 1318 unp_connect2(struct socket *so, struct socket *so2, int req) 1319 { 1320 struct unpcb *unp; 1321 struct unpcb *unp2; 1322 1323 unp = sotounpcb(so); 1324 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1325 unp2 = sotounpcb(so2); 1326 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1327 1328 UNP_LINK_WLOCK_ASSERT(); 1329 UNP_PCB_LOCK_ASSERT(unp); 1330 UNP_PCB_LOCK_ASSERT(unp2); 1331 1332 if (so2->so_type != so->so_type) 1333 return (EPROTOTYPE); 1334 unp->unp_conn = unp2; 1335 1336 switch (so->so_type) { 1337 case SOCK_DGRAM: 1338 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1339 soisconnected(so); 1340 break; 1341 1342 case SOCK_STREAM: 1343 unp2->unp_conn = unp; 1344 if (req == PRU_CONNECT && 1345 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1346 soisconnecting(so); 1347 else 1348 soisconnected(so); 1349 soisconnected(so2); 1350 break; 1351 1352 default: 1353 panic("unp_connect2"); 1354 } 1355 return (0); 1356 } 1357 1358 static void 1359 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1360 { 1361 struct socket *so; 1362 1363 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1364 1365 UNP_LINK_WLOCK_ASSERT(); 1366 UNP_PCB_LOCK_ASSERT(unp); 1367 UNP_PCB_LOCK_ASSERT(unp2); 1368 1369 unp->unp_conn = NULL; 1370 switch (unp->unp_socket->so_type) { 1371 case SOCK_DGRAM: 1372 LIST_REMOVE(unp, unp_reflink); 1373 so = unp->unp_socket; 1374 SOCK_LOCK(so); 1375 so->so_state &= ~SS_ISCONNECTED; 1376 SOCK_UNLOCK(so); 1377 break; 1378 1379 case SOCK_STREAM: 1380 soisdisconnected(unp->unp_socket); 1381 unp2->unp_conn = NULL; 1382 soisdisconnected(unp2->unp_socket); 1383 break; 1384 } 1385 } 1386 1387 /* 1388 * unp_pcblist() walks the global list of struct unpcb's to generate a 1389 * pointer list, bumping the refcount on each unpcb. It then copies them out 1390 * sequentially, validating the generation number on each to see if it has 1391 * been detached. All of this is necessary because copyout() may sleep on 1392 * disk I/O. 1393 */ 1394 static int 1395 unp_pcblist(SYSCTL_HANDLER_ARGS) 1396 { 1397 int error, i, n; 1398 int freeunp; 1399 struct unpcb *unp, **unp_list; 1400 unp_gen_t gencnt; 1401 struct xunpgen *xug; 1402 struct unp_head *head; 1403 struct xunpcb *xu; 1404 1405 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 1406 1407 /* 1408 * The process of preparing the PCB list is too time-consuming and 1409 * resource-intensive to repeat twice on every request. 1410 */ 1411 if (req->oldptr == NULL) { 1412 n = unp_count; 1413 req->oldidx = 2 * (sizeof *xug) 1414 + (n + n/8) * sizeof(struct xunpcb); 1415 return (0); 1416 } 1417 1418 if (req->newptr != NULL) 1419 return (EPERM); 1420 1421 /* 1422 * OK, now we're committed to doing something. 1423 */ 1424 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1425 UNP_LIST_LOCK(); 1426 gencnt = unp_gencnt; 1427 n = unp_count; 1428 UNP_LIST_UNLOCK(); 1429 1430 xug->xug_len = sizeof *xug; 1431 xug->xug_count = n; 1432 xug->xug_gen = gencnt; 1433 xug->xug_sogen = so_gencnt; 1434 error = SYSCTL_OUT(req, xug, sizeof *xug); 1435 if (error) { 1436 free(xug, M_TEMP); 1437 return (error); 1438 } 1439 1440 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1441 1442 UNP_LIST_LOCK(); 1443 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1444 unp = LIST_NEXT(unp, unp_link)) { 1445 UNP_PCB_LOCK(unp); 1446 if (unp->unp_gencnt <= gencnt) { 1447 if (cr_cansee(req->td->td_ucred, 1448 unp->unp_socket->so_cred)) { 1449 UNP_PCB_UNLOCK(unp); 1450 continue; 1451 } 1452 unp_list[i++] = unp; 1453 unp->unp_refcount++; 1454 } 1455 UNP_PCB_UNLOCK(unp); 1456 } 1457 UNP_LIST_UNLOCK(); 1458 n = i; /* In case we lost some during malloc. */ 1459 1460 error = 0; 1461 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1462 for (i = 0; i < n; i++) { 1463 unp = unp_list[i]; 1464 UNP_PCB_LOCK(unp); 1465 unp->unp_refcount--; 1466 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) { 1467 xu->xu_len = sizeof *xu; 1468 xu->xu_unpp = unp; 1469 /* 1470 * XXX - need more locking here to protect against 1471 * connect/disconnect races for SMP. 1472 */ 1473 if (unp->unp_addr != NULL) 1474 bcopy(unp->unp_addr, &xu->xu_addr, 1475 unp->unp_addr->sun_len); 1476 if (unp->unp_conn != NULL && 1477 unp->unp_conn->unp_addr != NULL) 1478 bcopy(unp->unp_conn->unp_addr, 1479 &xu->xu_caddr, 1480 unp->unp_conn->unp_addr->sun_len); 1481 bcopy(unp, &xu->xu_unp, sizeof *unp); 1482 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1483 UNP_PCB_UNLOCK(unp); 1484 error = SYSCTL_OUT(req, xu, sizeof *xu); 1485 } else { 1486 freeunp = (unp->unp_refcount == 0); 1487 UNP_PCB_UNLOCK(unp); 1488 if (freeunp) { 1489 UNP_PCB_LOCK_DESTROY(unp); 1490 uma_zfree(unp_zone, unp); 1491 } 1492 } 1493 } 1494 free(xu, M_TEMP); 1495 if (!error) { 1496 /* 1497 * Give the user an updated idea of our state. If the 1498 * generation differs from what we told her before, she knows 1499 * that something happened while we were processing this 1500 * request, and it might be necessary to retry. 1501 */ 1502 xug->xug_gen = unp_gencnt; 1503 xug->xug_sogen = so_gencnt; 1504 xug->xug_count = unp_count; 1505 error = SYSCTL_OUT(req, xug, sizeof *xug); 1506 } 1507 free(unp_list, M_TEMP); 1508 free(xug, M_TEMP); 1509 return (error); 1510 } 1511 1512 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 1513 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1514 "List of active local datagram sockets"); 1515 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 1516 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1517 "List of active local stream sockets"); 1518 1519 static void 1520 unp_shutdown(struct unpcb *unp) 1521 { 1522 struct unpcb *unp2; 1523 struct socket *so; 1524 1525 UNP_LINK_WLOCK_ASSERT(); 1526 UNP_PCB_LOCK_ASSERT(unp); 1527 1528 unp2 = unp->unp_conn; 1529 if (unp->unp_socket->so_type == SOCK_STREAM && unp2 != NULL) { 1530 so = unp2->unp_socket; 1531 if (so != NULL) 1532 socantrcvmore(so); 1533 } 1534 } 1535 1536 static void 1537 unp_drop(struct unpcb *unp, int errno) 1538 { 1539 struct socket *so = unp->unp_socket; 1540 struct unpcb *unp2; 1541 1542 UNP_LINK_WLOCK_ASSERT(); 1543 UNP_PCB_LOCK_ASSERT(unp); 1544 1545 so->so_error = errno; 1546 unp2 = unp->unp_conn; 1547 if (unp2 == NULL) 1548 return; 1549 UNP_PCB_LOCK(unp2); 1550 unp_disconnect(unp, unp2); 1551 UNP_PCB_UNLOCK(unp2); 1552 } 1553 1554 static void 1555 unp_freerights(struct file **rp, int fdcount) 1556 { 1557 int i; 1558 struct file *fp; 1559 1560 for (i = 0; i < fdcount; i++) { 1561 fp = *rp; 1562 *rp++ = NULL; 1563 unp_discard(fp); 1564 } 1565 } 1566 1567 static int 1568 unp_externalize(struct mbuf *control, struct mbuf **controlp) 1569 { 1570 struct thread *td = curthread; /* XXX */ 1571 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1572 int i; 1573 int *fdp; 1574 struct file **rp; 1575 struct file *fp; 1576 void *data; 1577 socklen_t clen = control->m_len, datalen; 1578 int error, newfds; 1579 int f; 1580 u_int newlen; 1581 1582 UNP_LINK_UNLOCK_ASSERT(); 1583 1584 error = 0; 1585 if (controlp != NULL) /* controlp == NULL => free control messages */ 1586 *controlp = NULL; 1587 while (cm != NULL) { 1588 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1589 error = EINVAL; 1590 break; 1591 } 1592 data = CMSG_DATA(cm); 1593 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1594 if (cm->cmsg_level == SOL_SOCKET 1595 && cm->cmsg_type == SCM_RIGHTS) { 1596 newfds = datalen / sizeof(struct file *); 1597 rp = data; 1598 1599 /* If we're not outputting the descriptors free them. */ 1600 if (error || controlp == NULL) { 1601 unp_freerights(rp, newfds); 1602 goto next; 1603 } 1604 FILEDESC_XLOCK(td->td_proc->p_fd); 1605 /* if the new FD's will not fit free them. */ 1606 if (!fdavail(td, newfds)) { 1607 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1608 error = EMSGSIZE; 1609 unp_freerights(rp, newfds); 1610 goto next; 1611 } 1612 1613 /* 1614 * Now change each pointer to an fd in the global 1615 * table to an integer that is the index to the local 1616 * fd table entry that we set up to point to the 1617 * global one we are transferring. 1618 */ 1619 newlen = newfds * sizeof(int); 1620 *controlp = sbcreatecontrol(NULL, newlen, 1621 SCM_RIGHTS, SOL_SOCKET); 1622 if (*controlp == NULL) { 1623 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1624 error = E2BIG; 1625 unp_freerights(rp, newfds); 1626 goto next; 1627 } 1628 1629 fdp = (int *) 1630 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1631 for (i = 0; i < newfds; i++) { 1632 if (fdalloc(td, 0, &f)) 1633 panic("unp_externalize fdalloc failed"); 1634 fp = *rp++; 1635 td->td_proc->p_fd->fd_ofiles[f] = fp; 1636 unp_externalize_fp(fp); 1637 *fdp++ = f; 1638 } 1639 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1640 } else { 1641 /* We can just copy anything else across. */ 1642 if (error || controlp == NULL) 1643 goto next; 1644 *controlp = sbcreatecontrol(NULL, datalen, 1645 cm->cmsg_type, cm->cmsg_level); 1646 if (*controlp == NULL) { 1647 error = ENOBUFS; 1648 goto next; 1649 } 1650 bcopy(data, 1651 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1652 datalen); 1653 } 1654 controlp = &(*controlp)->m_next; 1655 1656 next: 1657 if (CMSG_SPACE(datalen) < clen) { 1658 clen -= CMSG_SPACE(datalen); 1659 cm = (struct cmsghdr *) 1660 ((caddr_t)cm + CMSG_SPACE(datalen)); 1661 } else { 1662 clen = 0; 1663 cm = NULL; 1664 } 1665 } 1666 1667 m_freem(control); 1668 return (error); 1669 } 1670 1671 static void 1672 unp_zone_change(void *tag) 1673 { 1674 1675 uma_zone_set_max(unp_zone, maxsockets); 1676 } 1677 1678 static void 1679 unp_init(void) 1680 { 1681 1682 #ifdef VIMAGE 1683 if (!IS_DEFAULT_VNET(curvnet)) 1684 return; 1685 #endif 1686 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1687 NULL, NULL, UMA_ALIGN_PTR, 0); 1688 if (unp_zone == NULL) 1689 panic("unp_init"); 1690 uma_zone_set_max(unp_zone, maxsockets); 1691 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 1692 NULL, EVENTHANDLER_PRI_ANY); 1693 LIST_INIT(&unp_dhead); 1694 LIST_INIT(&unp_shead); 1695 SLIST_INIT(&unp_defers); 1696 TASK_INIT(&unp_gc_task, 0, unp_gc, NULL); 1697 TASK_INIT(&unp_defer_task, 0, unp_process_defers, NULL); 1698 UNP_LINK_LOCK_INIT(); 1699 UNP_LIST_LOCK_INIT(); 1700 UNP_DEFERRED_LOCK_INIT(); 1701 } 1702 1703 static int 1704 unp_internalize(struct mbuf **controlp, struct thread *td) 1705 { 1706 struct mbuf *control = *controlp; 1707 struct proc *p = td->td_proc; 1708 struct filedesc *fdescp = p->p_fd; 1709 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1710 struct cmsgcred *cmcred; 1711 struct file **rp; 1712 struct file *fp; 1713 struct timeval *tv; 1714 int i, fd, *fdp; 1715 void *data; 1716 socklen_t clen = control->m_len, datalen; 1717 int error, oldfds; 1718 u_int newlen; 1719 1720 UNP_LINK_UNLOCK_ASSERT(); 1721 1722 error = 0; 1723 *controlp = NULL; 1724 while (cm != NULL) { 1725 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1726 || cm->cmsg_len > clen) { 1727 error = EINVAL; 1728 goto out; 1729 } 1730 data = CMSG_DATA(cm); 1731 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1732 1733 switch (cm->cmsg_type) { 1734 /* 1735 * Fill in credential information. 1736 */ 1737 case SCM_CREDS: 1738 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1739 SCM_CREDS, SOL_SOCKET); 1740 if (*controlp == NULL) { 1741 error = ENOBUFS; 1742 goto out; 1743 } 1744 cmcred = (struct cmsgcred *) 1745 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1746 cmcred->cmcred_pid = p->p_pid; 1747 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1748 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1749 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1750 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1751 CMGROUP_MAX); 1752 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1753 cmcred->cmcred_groups[i] = 1754 td->td_ucred->cr_groups[i]; 1755 break; 1756 1757 case SCM_RIGHTS: 1758 oldfds = datalen / sizeof (int); 1759 /* 1760 * Check that all the FDs passed in refer to legal 1761 * files. If not, reject the entire operation. 1762 */ 1763 fdp = data; 1764 FILEDESC_SLOCK(fdescp); 1765 for (i = 0; i < oldfds; i++) { 1766 fd = *fdp++; 1767 if ((unsigned)fd >= fdescp->fd_nfiles || 1768 fdescp->fd_ofiles[fd] == NULL) { 1769 FILEDESC_SUNLOCK(fdescp); 1770 error = EBADF; 1771 goto out; 1772 } 1773 fp = fdescp->fd_ofiles[fd]; 1774 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1775 FILEDESC_SUNLOCK(fdescp); 1776 error = EOPNOTSUPP; 1777 goto out; 1778 } 1779 1780 } 1781 1782 /* 1783 * Now replace the integer FDs with pointers to the 1784 * associated global file table entry.. 1785 */ 1786 newlen = oldfds * sizeof(struct file *); 1787 *controlp = sbcreatecontrol(NULL, newlen, 1788 SCM_RIGHTS, SOL_SOCKET); 1789 if (*controlp == NULL) { 1790 FILEDESC_SUNLOCK(fdescp); 1791 error = E2BIG; 1792 goto out; 1793 } 1794 fdp = data; 1795 rp = (struct file **) 1796 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1797 for (i = 0; i < oldfds; i++) { 1798 fp = fdescp->fd_ofiles[*fdp++]; 1799 *rp++ = fp; 1800 unp_internalize_fp(fp); 1801 } 1802 FILEDESC_SUNLOCK(fdescp); 1803 break; 1804 1805 case SCM_TIMESTAMP: 1806 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1807 SCM_TIMESTAMP, SOL_SOCKET); 1808 if (*controlp == NULL) { 1809 error = ENOBUFS; 1810 goto out; 1811 } 1812 tv = (struct timeval *) 1813 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1814 microtime(tv); 1815 break; 1816 1817 default: 1818 error = EINVAL; 1819 goto out; 1820 } 1821 1822 controlp = &(*controlp)->m_next; 1823 if (CMSG_SPACE(datalen) < clen) { 1824 clen -= CMSG_SPACE(datalen); 1825 cm = (struct cmsghdr *) 1826 ((caddr_t)cm + CMSG_SPACE(datalen)); 1827 } else { 1828 clen = 0; 1829 cm = NULL; 1830 } 1831 } 1832 1833 out: 1834 m_freem(control); 1835 return (error); 1836 } 1837 1838 static struct mbuf * 1839 unp_addsockcred(struct thread *td, struct mbuf *control) 1840 { 1841 struct mbuf *m, *n, *n_prev; 1842 struct sockcred *sc; 1843 const struct cmsghdr *cm; 1844 int ngroups; 1845 int i; 1846 1847 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 1848 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 1849 if (m == NULL) 1850 return (control); 1851 1852 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 1853 sc->sc_uid = td->td_ucred->cr_ruid; 1854 sc->sc_euid = td->td_ucred->cr_uid; 1855 sc->sc_gid = td->td_ucred->cr_rgid; 1856 sc->sc_egid = td->td_ucred->cr_gid; 1857 sc->sc_ngroups = ngroups; 1858 for (i = 0; i < sc->sc_ngroups; i++) 1859 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 1860 1861 /* 1862 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 1863 * created SCM_CREDS control message (struct sockcred) has another 1864 * format. 1865 */ 1866 if (control != NULL) 1867 for (n = control, n_prev = NULL; n != NULL;) { 1868 cm = mtod(n, struct cmsghdr *); 1869 if (cm->cmsg_level == SOL_SOCKET && 1870 cm->cmsg_type == SCM_CREDS) { 1871 if (n_prev == NULL) 1872 control = n->m_next; 1873 else 1874 n_prev->m_next = n->m_next; 1875 n = m_free(n); 1876 } else { 1877 n_prev = n; 1878 n = n->m_next; 1879 } 1880 } 1881 1882 /* Prepend it to the head. */ 1883 m->m_next = control; 1884 return (m); 1885 } 1886 1887 static struct unpcb * 1888 fptounp(struct file *fp) 1889 { 1890 struct socket *so; 1891 1892 if (fp->f_type != DTYPE_SOCKET) 1893 return (NULL); 1894 if ((so = fp->f_data) == NULL) 1895 return (NULL); 1896 if (so->so_proto->pr_domain != &localdomain) 1897 return (NULL); 1898 return sotounpcb(so); 1899 } 1900 1901 static void 1902 unp_discard(struct file *fp) 1903 { 1904 struct unp_defer *dr; 1905 1906 if (unp_externalize_fp(fp)) { 1907 dr = malloc(sizeof(*dr), M_TEMP, M_WAITOK); 1908 dr->ud_fp = fp; 1909 UNP_DEFERRED_LOCK(); 1910 SLIST_INSERT_HEAD(&unp_defers, dr, ud_link); 1911 UNP_DEFERRED_UNLOCK(); 1912 atomic_add_int(&unp_defers_count, 1); 1913 taskqueue_enqueue(taskqueue_thread, &unp_defer_task); 1914 } else 1915 (void) closef(fp, (struct thread *)NULL); 1916 } 1917 1918 static void 1919 unp_process_defers(void *arg __unused, int pending) 1920 { 1921 struct unp_defer *dr; 1922 SLIST_HEAD(, unp_defer) drl; 1923 int count; 1924 1925 SLIST_INIT(&drl); 1926 for (;;) { 1927 UNP_DEFERRED_LOCK(); 1928 if (SLIST_FIRST(&unp_defers) == NULL) { 1929 UNP_DEFERRED_UNLOCK(); 1930 break; 1931 } 1932 SLIST_SWAP(&unp_defers, &drl, unp_defer); 1933 UNP_DEFERRED_UNLOCK(); 1934 count = 0; 1935 while ((dr = SLIST_FIRST(&drl)) != NULL) { 1936 SLIST_REMOVE_HEAD(&drl, ud_link); 1937 closef(dr->ud_fp, NULL); 1938 free(dr, M_TEMP); 1939 count++; 1940 } 1941 atomic_add_int(&unp_defers_count, -count); 1942 } 1943 } 1944 1945 static void 1946 unp_internalize_fp(struct file *fp) 1947 { 1948 struct unpcb *unp; 1949 1950 UNP_LINK_WLOCK(); 1951 if ((unp = fptounp(fp)) != NULL) { 1952 unp->unp_file = fp; 1953 unp->unp_msgcount++; 1954 } 1955 fhold(fp); 1956 unp_rights++; 1957 UNP_LINK_WUNLOCK(); 1958 } 1959 1960 static int 1961 unp_externalize_fp(struct file *fp) 1962 { 1963 struct unpcb *unp; 1964 int ret; 1965 1966 UNP_LINK_WLOCK(); 1967 if ((unp = fptounp(fp)) != NULL) { 1968 unp->unp_msgcount--; 1969 ret = 1; 1970 } else 1971 ret = 0; 1972 unp_rights--; 1973 UNP_LINK_WUNLOCK(); 1974 return (ret); 1975 } 1976 1977 /* 1978 * unp_defer indicates whether additional work has been defered for a future 1979 * pass through unp_gc(). It is thread local and does not require explicit 1980 * synchronization. 1981 */ 1982 static int unp_marked; 1983 static int unp_unreachable; 1984 1985 static void 1986 unp_accessable(struct file *fp) 1987 { 1988 struct unpcb *unp; 1989 1990 if ((unp = fptounp(fp)) == NULL) 1991 return; 1992 if (unp->unp_gcflag & UNPGC_REF) 1993 return; 1994 unp->unp_gcflag &= ~UNPGC_DEAD; 1995 unp->unp_gcflag |= UNPGC_REF; 1996 unp_marked++; 1997 } 1998 1999 static void 2000 unp_gc_process(struct unpcb *unp) 2001 { 2002 struct socket *soa; 2003 struct socket *so; 2004 struct file *fp; 2005 2006 /* Already processed. */ 2007 if (unp->unp_gcflag & UNPGC_SCANNED) 2008 return; 2009 fp = unp->unp_file; 2010 2011 /* 2012 * Check for a socket potentially in a cycle. It must be in a 2013 * queue as indicated by msgcount, and this must equal the file 2014 * reference count. Note that when msgcount is 0 the file is NULL. 2015 */ 2016 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 2017 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 2018 unp->unp_gcflag |= UNPGC_DEAD; 2019 unp_unreachable++; 2020 return; 2021 } 2022 2023 /* 2024 * Mark all sockets we reference with RIGHTS. 2025 */ 2026 so = unp->unp_socket; 2027 SOCKBUF_LOCK(&so->so_rcv); 2028 unp_scan(so->so_rcv.sb_mb, unp_accessable); 2029 SOCKBUF_UNLOCK(&so->so_rcv); 2030 2031 /* 2032 * Mark all sockets in our accept queue. 2033 */ 2034 ACCEPT_LOCK(); 2035 TAILQ_FOREACH(soa, &so->so_comp, so_list) { 2036 SOCKBUF_LOCK(&soa->so_rcv); 2037 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 2038 SOCKBUF_UNLOCK(&soa->so_rcv); 2039 } 2040 ACCEPT_UNLOCK(); 2041 unp->unp_gcflag |= UNPGC_SCANNED; 2042 } 2043 2044 static int unp_recycled; 2045 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 2046 "Number of unreachable sockets claimed by the garbage collector."); 2047 2048 static int unp_taskcount; 2049 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 2050 "Number of times the garbage collector has run."); 2051 2052 static void 2053 unp_gc(__unused void *arg, int pending) 2054 { 2055 struct unp_head *heads[] = { &unp_dhead, &unp_shead, NULL }; 2056 struct unp_head **head; 2057 struct file *f, **unref; 2058 struct unpcb *unp; 2059 int i, total; 2060 2061 unp_taskcount++; 2062 UNP_LIST_LOCK(); 2063 /* 2064 * First clear all gc flags from previous runs. 2065 */ 2066 for (head = heads; *head != NULL; head++) 2067 LIST_FOREACH(unp, *head, unp_link) 2068 unp->unp_gcflag = 0; 2069 2070 /* 2071 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 2072 * is reachable all of the sockets it references are reachable. 2073 * Stop the scan once we do a complete loop without discovering 2074 * a new reachable socket. 2075 */ 2076 do { 2077 unp_unreachable = 0; 2078 unp_marked = 0; 2079 for (head = heads; *head != NULL; head++) 2080 LIST_FOREACH(unp, *head, unp_link) 2081 unp_gc_process(unp); 2082 } while (unp_marked); 2083 UNP_LIST_UNLOCK(); 2084 if (unp_unreachable == 0) 2085 return; 2086 2087 /* 2088 * Allocate space for a local list of dead unpcbs. 2089 */ 2090 unref = malloc(unp_unreachable * sizeof(struct file *), 2091 M_TEMP, M_WAITOK); 2092 2093 /* 2094 * Iterate looking for sockets which have been specifically marked 2095 * as as unreachable and store them locally. 2096 */ 2097 UNP_LINK_RLOCK(); 2098 UNP_LIST_LOCK(); 2099 for (total = 0, head = heads; *head != NULL; head++) 2100 LIST_FOREACH(unp, *head, unp_link) 2101 if ((unp->unp_gcflag & UNPGC_DEAD) != 0) { 2102 f = unp->unp_file; 2103 if (unp->unp_msgcount == 0 || f == NULL || 2104 f->f_count != unp->unp_msgcount) 2105 continue; 2106 unref[total++] = f; 2107 fhold(f); 2108 KASSERT(total <= unp_unreachable, 2109 ("unp_gc: incorrect unreachable count.")); 2110 } 2111 UNP_LIST_UNLOCK(); 2112 UNP_LINK_RUNLOCK(); 2113 2114 /* 2115 * Now flush all sockets, free'ing rights. This will free the 2116 * struct files associated with these sockets but leave each socket 2117 * with one remaining ref. 2118 */ 2119 for (i = 0; i < total; i++) { 2120 struct socket *so; 2121 2122 so = unref[i]->f_data; 2123 CURVNET_SET(so->so_vnet); 2124 sorflush(so); 2125 CURVNET_RESTORE(); 2126 } 2127 2128 /* 2129 * And finally release the sockets so they can be reclaimed. 2130 */ 2131 for (i = 0; i < total; i++) 2132 fdrop(unref[i], NULL); 2133 unp_recycled += total; 2134 free(unref, M_TEMP); 2135 } 2136 2137 static void 2138 unp_dispose(struct mbuf *m) 2139 { 2140 2141 if (m) 2142 unp_scan(m, unp_discard); 2143 } 2144 2145 static void 2146 unp_scan(struct mbuf *m0, void (*op)(struct file *)) 2147 { 2148 struct mbuf *m; 2149 struct file **rp; 2150 struct cmsghdr *cm; 2151 void *data; 2152 int i; 2153 socklen_t clen, datalen; 2154 int qfds; 2155 2156 while (m0 != NULL) { 2157 for (m = m0; m; m = m->m_next) { 2158 if (m->m_type != MT_CONTROL) 2159 continue; 2160 2161 cm = mtod(m, struct cmsghdr *); 2162 clen = m->m_len; 2163 2164 while (cm != NULL) { 2165 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2166 break; 2167 2168 data = CMSG_DATA(cm); 2169 datalen = (caddr_t)cm + cm->cmsg_len 2170 - (caddr_t)data; 2171 2172 if (cm->cmsg_level == SOL_SOCKET && 2173 cm->cmsg_type == SCM_RIGHTS) { 2174 qfds = datalen / sizeof (struct file *); 2175 rp = data; 2176 for (i = 0; i < qfds; i++) 2177 (*op)(*rp++); 2178 } 2179 2180 if (CMSG_SPACE(datalen) < clen) { 2181 clen -= CMSG_SPACE(datalen); 2182 cm = (struct cmsghdr *) 2183 ((caddr_t)cm + CMSG_SPACE(datalen)); 2184 } else { 2185 clen = 0; 2186 cm = NULL; 2187 } 2188 } 2189 } 2190 m0 = m0->m_act; 2191 } 2192 } 2193 2194 #ifdef DDB 2195 static void 2196 db_print_indent(int indent) 2197 { 2198 int i; 2199 2200 for (i = 0; i < indent; i++) 2201 db_printf(" "); 2202 } 2203 2204 static void 2205 db_print_unpflags(int unp_flags) 2206 { 2207 int comma; 2208 2209 comma = 0; 2210 if (unp_flags & UNP_HAVEPC) { 2211 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2212 comma = 1; 2213 } 2214 if (unp_flags & UNP_HAVEPCCACHED) { 2215 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : ""); 2216 comma = 1; 2217 } 2218 if (unp_flags & UNP_WANTCRED) { 2219 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2220 comma = 1; 2221 } 2222 if (unp_flags & UNP_CONNWAIT) { 2223 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2224 comma = 1; 2225 } 2226 if (unp_flags & UNP_CONNECTING) { 2227 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2228 comma = 1; 2229 } 2230 if (unp_flags & UNP_BINDING) { 2231 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2232 comma = 1; 2233 } 2234 } 2235 2236 static void 2237 db_print_xucred(int indent, struct xucred *xu) 2238 { 2239 int comma, i; 2240 2241 db_print_indent(indent); 2242 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2243 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2244 db_print_indent(indent); 2245 db_printf("cr_groups: "); 2246 comma = 0; 2247 for (i = 0; i < xu->cr_ngroups; i++) { 2248 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2249 comma = 1; 2250 } 2251 db_printf("\n"); 2252 } 2253 2254 static void 2255 db_print_unprefs(int indent, struct unp_head *uh) 2256 { 2257 struct unpcb *unp; 2258 int counter; 2259 2260 counter = 0; 2261 LIST_FOREACH(unp, uh, unp_reflink) { 2262 if (counter % 4 == 0) 2263 db_print_indent(indent); 2264 db_printf("%p ", unp); 2265 if (counter % 4 == 3) 2266 db_printf("\n"); 2267 counter++; 2268 } 2269 if (counter != 0 && counter % 4 != 0) 2270 db_printf("\n"); 2271 } 2272 2273 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2274 { 2275 struct unpcb *unp; 2276 2277 if (!have_addr) { 2278 db_printf("usage: show unpcb <addr>\n"); 2279 return; 2280 } 2281 unp = (struct unpcb *)addr; 2282 2283 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2284 unp->unp_vnode); 2285 2286 db_printf("unp_ino: %d unp_conn: %p\n", unp->unp_ino, 2287 unp->unp_conn); 2288 2289 db_printf("unp_refs:\n"); 2290 db_print_unprefs(2, &unp->unp_refs); 2291 2292 /* XXXRW: Would be nice to print the full address, if any. */ 2293 db_printf("unp_addr: %p\n", unp->unp_addr); 2294 2295 db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n", 2296 unp->unp_cc, unp->unp_mbcnt, 2297 (unsigned long long)unp->unp_gencnt); 2298 2299 db_printf("unp_flags: %x (", unp->unp_flags); 2300 db_print_unpflags(unp->unp_flags); 2301 db_printf(")\n"); 2302 2303 db_printf("unp_peercred:\n"); 2304 db_print_xucred(2, &unp->unp_peercred); 2305 2306 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2307 } 2308 #endif
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