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/8.0/sys/kern/uipc_usrreq.c 196019 2009-08-01 19:26:27Z rwatson $"); 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 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 398 if (namelen <= 0) 399 return (EINVAL); 400 401 /* 402 * We don't allow simultaneous bind() calls on a single UNIX domain 403 * socket, so flag in-progress operations, and return an error if an 404 * operation is already in progress. 405 * 406 * Historically, we have not allowed a socket to be rebound, so this 407 * also returns an error. Not allowing re-binding simplifies the 408 * implementation and avoids a great many possible failure modes. 409 */ 410 UNP_PCB_LOCK(unp); 411 if (unp->unp_vnode != NULL) { 412 UNP_PCB_UNLOCK(unp); 413 return (EINVAL); 414 } 415 if (unp->unp_flags & UNP_BINDING) { 416 UNP_PCB_UNLOCK(unp); 417 return (EALREADY); 418 } 419 unp->unp_flags |= UNP_BINDING; 420 UNP_PCB_UNLOCK(unp); 421 422 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 423 bcopy(soun->sun_path, buf, namelen); 424 buf[namelen] = 0; 425 426 restart: 427 vfslocked = 0; 428 NDINIT(&nd, CREATE, MPSAFE | NOFOLLOW | LOCKPARENT | SAVENAME, 429 UIO_SYSSPACE, buf, td); 430 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 431 error = namei(&nd); 432 if (error) 433 goto error; 434 vp = nd.ni_vp; 435 vfslocked = NDHASGIANT(&nd); 436 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 437 NDFREE(&nd, NDF_ONLY_PNBUF); 438 if (nd.ni_dvp == vp) 439 vrele(nd.ni_dvp); 440 else 441 vput(nd.ni_dvp); 442 if (vp != NULL) { 443 vrele(vp); 444 error = EADDRINUSE; 445 goto error; 446 } 447 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 448 if (error) 449 goto error; 450 VFS_UNLOCK_GIANT(vfslocked); 451 goto restart; 452 } 453 VATTR_NULL(&vattr); 454 vattr.va_type = VSOCK; 455 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 456 #ifdef MAC 457 error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 458 &vattr); 459 #endif 460 if (error == 0) 461 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 462 NDFREE(&nd, NDF_ONLY_PNBUF); 463 vput(nd.ni_dvp); 464 if (error) { 465 vn_finished_write(mp); 466 goto error; 467 } 468 vp = nd.ni_vp; 469 ASSERT_VOP_ELOCKED(vp, "uipc_bind"); 470 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 471 472 UNP_LINK_WLOCK(); 473 UNP_PCB_LOCK(unp); 474 vp->v_socket = unp->unp_socket; 475 unp->unp_vnode = vp; 476 unp->unp_addr = soun; 477 unp->unp_flags &= ~UNP_BINDING; 478 UNP_PCB_UNLOCK(unp); 479 UNP_LINK_WUNLOCK(); 480 VOP_UNLOCK(vp, 0); 481 vn_finished_write(mp); 482 VFS_UNLOCK_GIANT(vfslocked); 483 free(buf, M_TEMP); 484 return (0); 485 486 error: 487 VFS_UNLOCK_GIANT(vfslocked); 488 UNP_PCB_LOCK(unp); 489 unp->unp_flags &= ~UNP_BINDING; 490 UNP_PCB_UNLOCK(unp); 491 free(buf, M_TEMP); 492 return (error); 493 } 494 495 static int 496 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 497 { 498 int error; 499 500 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 501 UNP_LINK_WLOCK(); 502 error = unp_connect(so, nam, td); 503 UNP_LINK_WUNLOCK(); 504 return (error); 505 } 506 507 static void 508 uipc_close(struct socket *so) 509 { 510 struct unpcb *unp, *unp2; 511 512 unp = sotounpcb(so); 513 KASSERT(unp != NULL, ("uipc_close: unp == NULL")); 514 515 UNP_LINK_WLOCK(); 516 UNP_PCB_LOCK(unp); 517 unp2 = unp->unp_conn; 518 if (unp2 != NULL) { 519 UNP_PCB_LOCK(unp2); 520 unp_disconnect(unp, unp2); 521 UNP_PCB_UNLOCK(unp2); 522 } 523 UNP_PCB_UNLOCK(unp); 524 UNP_LINK_WUNLOCK(); 525 } 526 527 static int 528 uipc_connect2(struct socket *so1, struct socket *so2) 529 { 530 struct unpcb *unp, *unp2; 531 int error; 532 533 UNP_LINK_WLOCK(); 534 unp = so1->so_pcb; 535 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 536 UNP_PCB_LOCK(unp); 537 unp2 = so2->so_pcb; 538 KASSERT(unp2 != NULL, ("uipc_connect2: unp2 == NULL")); 539 UNP_PCB_LOCK(unp2); 540 error = unp_connect2(so1, so2, PRU_CONNECT2); 541 UNP_PCB_UNLOCK(unp2); 542 UNP_PCB_UNLOCK(unp); 543 UNP_LINK_WUNLOCK(); 544 return (error); 545 } 546 547 static void 548 uipc_detach(struct socket *so) 549 { 550 struct unpcb *unp, *unp2; 551 struct sockaddr_un *saved_unp_addr; 552 struct vnode *vp; 553 int freeunp, local_unp_rights; 554 555 unp = sotounpcb(so); 556 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 557 558 UNP_LINK_WLOCK(); 559 UNP_LIST_LOCK(); 560 UNP_PCB_LOCK(unp); 561 LIST_REMOVE(unp, unp_link); 562 unp->unp_gencnt = ++unp_gencnt; 563 --unp_count; 564 UNP_LIST_UNLOCK(); 565 566 /* 567 * XXXRW: Should assert vp->v_socket == so. 568 */ 569 if ((vp = unp->unp_vnode) != NULL) { 570 unp->unp_vnode->v_socket = NULL; 571 unp->unp_vnode = NULL; 572 } 573 unp2 = unp->unp_conn; 574 if (unp2 != NULL) { 575 UNP_PCB_LOCK(unp2); 576 unp_disconnect(unp, unp2); 577 UNP_PCB_UNLOCK(unp2); 578 } 579 580 /* 581 * We hold the linkage lock exclusively, so it's OK to acquire 582 * multiple pcb locks at a time. 583 */ 584 while (!LIST_EMPTY(&unp->unp_refs)) { 585 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 586 587 UNP_PCB_LOCK(ref); 588 unp_drop(ref, ECONNRESET); 589 UNP_PCB_UNLOCK(ref); 590 } 591 local_unp_rights = unp_rights; 592 UNP_LINK_WUNLOCK(); 593 unp->unp_socket->so_pcb = NULL; 594 saved_unp_addr = unp->unp_addr; 595 unp->unp_addr = NULL; 596 unp->unp_refcount--; 597 freeunp = (unp->unp_refcount == 0); 598 if (saved_unp_addr != NULL) 599 free(saved_unp_addr, M_SONAME); 600 if (freeunp) { 601 UNP_PCB_LOCK_DESTROY(unp); 602 uma_zfree(unp_zone, unp); 603 } else 604 UNP_PCB_UNLOCK(unp); 605 if (vp) { 606 int vfslocked; 607 608 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 609 vrele(vp); 610 VFS_UNLOCK_GIANT(vfslocked); 611 } 612 if (local_unp_rights) 613 taskqueue_enqueue(taskqueue_thread, &unp_gc_task); 614 } 615 616 static int 617 uipc_disconnect(struct socket *so) 618 { 619 struct unpcb *unp, *unp2; 620 621 unp = sotounpcb(so); 622 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 623 624 UNP_LINK_WLOCK(); 625 UNP_PCB_LOCK(unp); 626 unp2 = unp->unp_conn; 627 if (unp2 != NULL) { 628 UNP_PCB_LOCK(unp2); 629 unp_disconnect(unp, unp2); 630 UNP_PCB_UNLOCK(unp2); 631 } 632 UNP_PCB_UNLOCK(unp); 633 UNP_LINK_WUNLOCK(); 634 return (0); 635 } 636 637 static int 638 uipc_listen(struct socket *so, int backlog, struct thread *td) 639 { 640 struct unpcb *unp; 641 int error; 642 643 unp = sotounpcb(so); 644 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 645 646 UNP_PCB_LOCK(unp); 647 if (unp->unp_vnode == NULL) { 648 UNP_PCB_UNLOCK(unp); 649 return (EINVAL); 650 } 651 652 SOCK_LOCK(so); 653 error = solisten_proto_check(so); 654 if (error == 0) { 655 cru2x(td->td_ucred, &unp->unp_peercred); 656 unp->unp_flags |= UNP_HAVEPCCACHED; 657 solisten_proto(so, backlog); 658 } 659 SOCK_UNLOCK(so); 660 UNP_PCB_UNLOCK(unp); 661 return (error); 662 } 663 664 static int 665 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 666 { 667 struct unpcb *unp, *unp2; 668 const struct sockaddr *sa; 669 670 unp = sotounpcb(so); 671 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 672 673 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 674 UNP_LINK_RLOCK(); 675 /* 676 * XXX: It seems that this test always fails even when connection is 677 * established. So, this else clause is added as workaround to 678 * return PF_LOCAL sockaddr. 679 */ 680 unp2 = unp->unp_conn; 681 if (unp2 != NULL) { 682 UNP_PCB_LOCK(unp2); 683 if (unp2->unp_addr != NULL) 684 sa = (struct sockaddr *) unp2->unp_addr; 685 else 686 sa = &sun_noname; 687 bcopy(sa, *nam, sa->sa_len); 688 UNP_PCB_UNLOCK(unp2); 689 } else { 690 sa = &sun_noname; 691 bcopy(sa, *nam, sa->sa_len); 692 } 693 UNP_LINK_RUNLOCK(); 694 return (0); 695 } 696 697 static int 698 uipc_rcvd(struct socket *so, int flags) 699 { 700 struct unpcb *unp, *unp2; 701 struct socket *so2; 702 u_int mbcnt, sbcc; 703 u_long newhiwat; 704 705 unp = sotounpcb(so); 706 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL")); 707 708 if (so->so_type == SOCK_DGRAM) 709 panic("uipc_rcvd DGRAM?"); 710 711 if (so->so_type != SOCK_STREAM) 712 panic("uipc_rcvd unknown socktype"); 713 714 /* 715 * Adjust backpressure on sender and wakeup any waiting to write. 716 * 717 * The unp lock is acquired to maintain the validity of the unp_conn 718 * pointer; no lock on unp2 is required as unp2->unp_socket will be 719 * static as long as we don't permit unp2 to disconnect from unp, 720 * which is prevented by the lock on unp. We cache values from 721 * so_rcv to avoid holding the so_rcv lock over the entire 722 * transaction on the remote so_snd. 723 */ 724 SOCKBUF_LOCK(&so->so_rcv); 725 mbcnt = so->so_rcv.sb_mbcnt; 726 sbcc = so->so_rcv.sb_cc; 727 SOCKBUF_UNLOCK(&so->so_rcv); 728 UNP_PCB_LOCK(unp); 729 unp2 = unp->unp_conn; 730 if (unp2 == NULL) { 731 UNP_PCB_UNLOCK(unp); 732 return (0); 733 } 734 so2 = unp2->unp_socket; 735 SOCKBUF_LOCK(&so2->so_snd); 736 so2->so_snd.sb_mbmax += unp->unp_mbcnt - mbcnt; 737 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - sbcc; 738 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, 739 newhiwat, RLIM_INFINITY); 740 sowwakeup_locked(so2); 741 unp->unp_mbcnt = mbcnt; 742 unp->unp_cc = sbcc; 743 UNP_PCB_UNLOCK(unp); 744 return (0); 745 } 746 747 static int 748 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 749 struct mbuf *control, struct thread *td) 750 { 751 struct unpcb *unp, *unp2; 752 struct socket *so2; 753 u_int mbcnt_delta, sbcc; 754 u_long newhiwat; 755 int error = 0; 756 757 unp = sotounpcb(so); 758 KASSERT(unp != NULL, ("uipc_send: unp == NULL")); 759 760 if (flags & PRUS_OOB) { 761 error = EOPNOTSUPP; 762 goto release; 763 } 764 if (control != NULL && (error = unp_internalize(&control, td))) 765 goto release; 766 if ((nam != NULL) || (flags & PRUS_EOF)) 767 UNP_LINK_WLOCK(); 768 else 769 UNP_LINK_RLOCK(); 770 switch (so->so_type) { 771 case SOCK_DGRAM: 772 { 773 const struct sockaddr *from; 774 775 unp2 = unp->unp_conn; 776 if (nam != NULL) { 777 UNP_LINK_WLOCK_ASSERT(); 778 if (unp2 != NULL) { 779 error = EISCONN; 780 break; 781 } 782 error = unp_connect(so, nam, td); 783 if (error) 784 break; 785 unp2 = unp->unp_conn; 786 } 787 788 /* 789 * Because connect() and send() are non-atomic in a sendto() 790 * with a target address, it's possible that the socket will 791 * have disconnected before the send() can run. In that case 792 * return the slightly counter-intuitive but otherwise 793 * correct error that the socket is not connected. 794 */ 795 if (unp2 == NULL) { 796 error = ENOTCONN; 797 break; 798 } 799 /* Lockless read. */ 800 if (unp2->unp_flags & UNP_WANTCRED) 801 control = unp_addsockcred(td, control); 802 UNP_PCB_LOCK(unp); 803 if (unp->unp_addr != NULL) 804 from = (struct sockaddr *)unp->unp_addr; 805 else 806 from = &sun_noname; 807 so2 = unp2->unp_socket; 808 SOCKBUF_LOCK(&so2->so_rcv); 809 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) { 810 sorwakeup_locked(so2); 811 m = NULL; 812 control = NULL; 813 } else { 814 SOCKBUF_UNLOCK(&so2->so_rcv); 815 error = ENOBUFS; 816 } 817 if (nam != NULL) { 818 UNP_LINK_WLOCK_ASSERT(); 819 UNP_PCB_LOCK(unp2); 820 unp_disconnect(unp, unp2); 821 UNP_PCB_UNLOCK(unp2); 822 } 823 UNP_PCB_UNLOCK(unp); 824 break; 825 } 826 827 case SOCK_STREAM: 828 if ((so->so_state & SS_ISCONNECTED) == 0) { 829 if (nam != NULL) { 830 UNP_LINK_WLOCK_ASSERT(); 831 error = unp_connect(so, nam, td); 832 if (error) 833 break; /* XXX */ 834 } else { 835 error = ENOTCONN; 836 break; 837 } 838 } 839 840 /* Lockless read. */ 841 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 842 error = EPIPE; 843 break; 844 } 845 846 /* 847 * Because connect() and send() are non-atomic in a sendto() 848 * with a target address, it's possible that the socket will 849 * have disconnected before the send() can run. In that case 850 * return the slightly counter-intuitive but otherwise 851 * correct error that the socket is not connected. 852 * 853 * Locking here must be done carefully: the linkage lock 854 * prevents interconnections between unpcbs from changing, so 855 * we can traverse from unp to unp2 without acquiring unp's 856 * lock. Socket buffer locks follow unpcb locks, so we can 857 * acquire both remote and lock socket buffer locks. 858 */ 859 unp2 = unp->unp_conn; 860 if (unp2 == NULL) { 861 error = ENOTCONN; 862 break; 863 } 864 so2 = unp2->unp_socket; 865 UNP_PCB_LOCK(unp2); 866 SOCKBUF_LOCK(&so2->so_rcv); 867 if (unp2->unp_flags & UNP_WANTCRED) { 868 /* 869 * Credentials are passed only once on SOCK_STREAM. 870 */ 871 unp2->unp_flags &= ~UNP_WANTCRED; 872 control = unp_addsockcred(td, control); 873 } 874 /* 875 * Send to paired receive port, and then reduce send buffer 876 * hiwater marks to maintain backpressure. Wake up readers. 877 */ 878 if (control != NULL) { 879 if (sbappendcontrol_locked(&so2->so_rcv, m, control)) 880 control = NULL; 881 } else 882 sbappend_locked(&so2->so_rcv, m); 883 mbcnt_delta = so2->so_rcv.sb_mbcnt - unp2->unp_mbcnt; 884 unp2->unp_mbcnt = so2->so_rcv.sb_mbcnt; 885 sbcc = so2->so_rcv.sb_cc; 886 sorwakeup_locked(so2); 887 888 SOCKBUF_LOCK(&so->so_snd); 889 newhiwat = so->so_snd.sb_hiwat - (sbcc - unp2->unp_cc); 890 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, 891 newhiwat, RLIM_INFINITY); 892 so->so_snd.sb_mbmax -= mbcnt_delta; 893 SOCKBUF_UNLOCK(&so->so_snd); 894 unp2->unp_cc = sbcc; 895 UNP_PCB_UNLOCK(unp2); 896 m = NULL; 897 break; 898 899 default: 900 panic("uipc_send unknown socktype"); 901 } 902 903 /* 904 * PRUS_EOF is equivalent to pru_send followed by pru_shutdown. 905 */ 906 if (flags & PRUS_EOF) { 907 UNP_PCB_LOCK(unp); 908 socantsendmore(so); 909 unp_shutdown(unp); 910 UNP_PCB_UNLOCK(unp); 911 } 912 913 if ((nam != NULL) || (flags & PRUS_EOF)) 914 UNP_LINK_WUNLOCK(); 915 else 916 UNP_LINK_RUNLOCK(); 917 918 if (control != NULL && error != 0) 919 unp_dispose(control); 920 921 release: 922 if (control != NULL) 923 m_freem(control); 924 if (m != NULL) 925 m_freem(m); 926 return (error); 927 } 928 929 static int 930 uipc_sense(struct socket *so, struct stat *sb) 931 { 932 struct unpcb *unp, *unp2; 933 struct socket *so2; 934 935 unp = sotounpcb(so); 936 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 937 938 sb->st_blksize = so->so_snd.sb_hiwat; 939 UNP_LINK_RLOCK(); 940 UNP_PCB_LOCK(unp); 941 unp2 = unp->unp_conn; 942 if (so->so_type == SOCK_STREAM && unp2 != NULL) { 943 so2 = unp2->unp_socket; 944 sb->st_blksize += so2->so_rcv.sb_cc; 945 } 946 sb->st_dev = NODEV; 947 if (unp->unp_ino == 0) 948 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 949 sb->st_ino = unp->unp_ino; 950 UNP_PCB_UNLOCK(unp); 951 UNP_LINK_RUNLOCK(); 952 return (0); 953 } 954 955 static int 956 uipc_shutdown(struct socket *so) 957 { 958 struct unpcb *unp; 959 960 unp = sotounpcb(so); 961 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 962 963 UNP_LINK_WLOCK(); 964 UNP_PCB_LOCK(unp); 965 socantsendmore(so); 966 unp_shutdown(unp); 967 UNP_PCB_UNLOCK(unp); 968 UNP_LINK_WUNLOCK(); 969 return (0); 970 } 971 972 static int 973 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 974 { 975 struct unpcb *unp; 976 const struct sockaddr *sa; 977 978 unp = sotounpcb(so); 979 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 980 981 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 982 UNP_PCB_LOCK(unp); 983 if (unp->unp_addr != NULL) 984 sa = (struct sockaddr *) unp->unp_addr; 985 else 986 sa = &sun_noname; 987 bcopy(sa, *nam, sa->sa_len); 988 UNP_PCB_UNLOCK(unp); 989 return (0); 990 } 991 992 static struct pr_usrreqs uipc_usrreqs_dgram = { 993 .pru_abort = uipc_abort, 994 .pru_accept = uipc_accept, 995 .pru_attach = uipc_attach, 996 .pru_bind = uipc_bind, 997 .pru_connect = uipc_connect, 998 .pru_connect2 = uipc_connect2, 999 .pru_detach = uipc_detach, 1000 .pru_disconnect = uipc_disconnect, 1001 .pru_listen = uipc_listen, 1002 .pru_peeraddr = uipc_peeraddr, 1003 .pru_rcvd = uipc_rcvd, 1004 .pru_send = uipc_send, 1005 .pru_sense = uipc_sense, 1006 .pru_shutdown = uipc_shutdown, 1007 .pru_sockaddr = uipc_sockaddr, 1008 .pru_soreceive = soreceive_dgram, 1009 .pru_close = uipc_close, 1010 }; 1011 1012 static struct pr_usrreqs uipc_usrreqs_stream = { 1013 .pru_abort = uipc_abort, 1014 .pru_accept = uipc_accept, 1015 .pru_attach = uipc_attach, 1016 .pru_bind = uipc_bind, 1017 .pru_connect = uipc_connect, 1018 .pru_connect2 = uipc_connect2, 1019 .pru_detach = uipc_detach, 1020 .pru_disconnect = uipc_disconnect, 1021 .pru_listen = uipc_listen, 1022 .pru_peeraddr = uipc_peeraddr, 1023 .pru_rcvd = uipc_rcvd, 1024 .pru_send = uipc_send, 1025 .pru_sense = uipc_sense, 1026 .pru_shutdown = uipc_shutdown, 1027 .pru_sockaddr = uipc_sockaddr, 1028 .pru_soreceive = soreceive_generic, 1029 .pru_close = uipc_close, 1030 }; 1031 1032 static int 1033 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 1034 { 1035 struct unpcb *unp; 1036 struct xucred xu; 1037 int error, optval; 1038 1039 if (sopt->sopt_level != 0) 1040 return (EINVAL); 1041 1042 unp = sotounpcb(so); 1043 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 1044 error = 0; 1045 switch (sopt->sopt_dir) { 1046 case SOPT_GET: 1047 switch (sopt->sopt_name) { 1048 case LOCAL_PEERCRED: 1049 UNP_PCB_LOCK(unp); 1050 if (unp->unp_flags & UNP_HAVEPC) 1051 xu = unp->unp_peercred; 1052 else { 1053 if (so->so_type == SOCK_STREAM) 1054 error = ENOTCONN; 1055 else 1056 error = EINVAL; 1057 } 1058 UNP_PCB_UNLOCK(unp); 1059 if (error == 0) 1060 error = sooptcopyout(sopt, &xu, sizeof(xu)); 1061 break; 1062 1063 case LOCAL_CREDS: 1064 /* Unlocked read. */ 1065 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 1066 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1067 break; 1068 1069 case LOCAL_CONNWAIT: 1070 /* Unlocked read. */ 1071 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 1072 error = sooptcopyout(sopt, &optval, sizeof(optval)); 1073 break; 1074 1075 default: 1076 error = EOPNOTSUPP; 1077 break; 1078 } 1079 break; 1080 1081 case SOPT_SET: 1082 switch (sopt->sopt_name) { 1083 case LOCAL_CREDS: 1084 case LOCAL_CONNWAIT: 1085 error = sooptcopyin(sopt, &optval, sizeof(optval), 1086 sizeof(optval)); 1087 if (error) 1088 break; 1089 1090 #define OPTSET(bit) do { \ 1091 UNP_PCB_LOCK(unp); \ 1092 if (optval) \ 1093 unp->unp_flags |= bit; \ 1094 else \ 1095 unp->unp_flags &= ~bit; \ 1096 UNP_PCB_UNLOCK(unp); \ 1097 } while (0) 1098 1099 switch (sopt->sopt_name) { 1100 case LOCAL_CREDS: 1101 OPTSET(UNP_WANTCRED); 1102 break; 1103 1104 case LOCAL_CONNWAIT: 1105 OPTSET(UNP_CONNWAIT); 1106 break; 1107 1108 default: 1109 break; 1110 } 1111 break; 1112 #undef OPTSET 1113 default: 1114 error = ENOPROTOOPT; 1115 break; 1116 } 1117 break; 1118 1119 default: 1120 error = EOPNOTSUPP; 1121 break; 1122 } 1123 return (error); 1124 } 1125 1126 static int 1127 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 1128 { 1129 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 1130 struct vnode *vp; 1131 struct socket *so2, *so3; 1132 struct unpcb *unp, *unp2, *unp3; 1133 int error, len, vfslocked; 1134 struct nameidata nd; 1135 char buf[SOCK_MAXADDRLEN]; 1136 struct sockaddr *sa; 1137 1138 UNP_LINK_WLOCK_ASSERT(); 1139 1140 unp = sotounpcb(so); 1141 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1142 1143 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 1144 if (len <= 0) 1145 return (EINVAL); 1146 bcopy(soun->sun_path, buf, len); 1147 buf[len] = 0; 1148 1149 UNP_PCB_LOCK(unp); 1150 if (unp->unp_flags & UNP_CONNECTING) { 1151 UNP_PCB_UNLOCK(unp); 1152 return (EALREADY); 1153 } 1154 UNP_LINK_WUNLOCK(); 1155 unp->unp_flags |= UNP_CONNECTING; 1156 UNP_PCB_UNLOCK(unp); 1157 1158 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 1159 NDINIT(&nd, LOOKUP, MPSAFE | FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, 1160 td); 1161 error = namei(&nd); 1162 if (error) 1163 vp = NULL; 1164 else 1165 vp = nd.ni_vp; 1166 ASSERT_VOP_LOCKED(vp, "unp_connect"); 1167 vfslocked = NDHASGIANT(&nd); 1168 NDFREE(&nd, NDF_ONLY_PNBUF); 1169 if (error) 1170 goto bad; 1171 1172 if (vp->v_type != VSOCK) { 1173 error = ENOTSOCK; 1174 goto bad; 1175 } 1176 #ifdef MAC 1177 error = mac_vnode_check_open(td->td_ucred, vp, VWRITE | VREAD); 1178 if (error) 1179 goto bad; 1180 #endif 1181 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 1182 if (error) 1183 goto bad; 1184 VFS_UNLOCK_GIANT(vfslocked); 1185 1186 unp = sotounpcb(so); 1187 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1188 1189 /* 1190 * Lock linkage lock for two reasons: make sure v_socket is stable, 1191 * and to protect simultaneous locking of multiple pcbs. 1192 */ 1193 UNP_LINK_WLOCK(); 1194 so2 = vp->v_socket; 1195 if (so2 == NULL) { 1196 error = ECONNREFUSED; 1197 goto bad2; 1198 } 1199 if (so->so_type != so2->so_type) { 1200 error = EPROTOTYPE; 1201 goto bad2; 1202 } 1203 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1204 if (so2->so_options & SO_ACCEPTCONN) { 1205 so3 = sonewconn(so2, 0); 1206 } else 1207 so3 = NULL; 1208 if (so3 == NULL) { 1209 error = ECONNREFUSED; 1210 goto bad2; 1211 } 1212 unp = sotounpcb(so); 1213 unp2 = sotounpcb(so2); 1214 unp3 = sotounpcb(so3); 1215 UNP_PCB_LOCK(unp); 1216 UNP_PCB_LOCK(unp2); 1217 UNP_PCB_LOCK(unp3); 1218 if (unp2->unp_addr != NULL) { 1219 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 1220 unp3->unp_addr = (struct sockaddr_un *) sa; 1221 sa = NULL; 1222 } 1223 1224 /* 1225 * The connecter's (client's) credentials are copied from its 1226 * process structure at the time of connect() (which is now). 1227 */ 1228 cru2x(td->td_ucred, &unp3->unp_peercred); 1229 unp3->unp_flags |= UNP_HAVEPC; 1230 1231 /* 1232 * The receiver's (server's) credentials are copied from the 1233 * unp_peercred member of socket on which the former called 1234 * listen(); uipc_listen() cached that process's credentials 1235 * at that time so we can use them now. 1236 */ 1237 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1238 ("unp_connect: listener without cached peercred")); 1239 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1240 sizeof(unp->unp_peercred)); 1241 unp->unp_flags |= UNP_HAVEPC; 1242 if (unp2->unp_flags & UNP_WANTCRED) 1243 unp3->unp_flags |= UNP_WANTCRED; 1244 UNP_PCB_UNLOCK(unp3); 1245 UNP_PCB_UNLOCK(unp2); 1246 UNP_PCB_UNLOCK(unp); 1247 #ifdef MAC 1248 mac_socketpeer_set_from_socket(so, so3); 1249 mac_socketpeer_set_from_socket(so3, so); 1250 #endif 1251 1252 so2 = so3; 1253 } 1254 unp = sotounpcb(so); 1255 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 1256 unp2 = sotounpcb(so2); 1257 KASSERT(unp2 != NULL, ("unp_connect: unp2 == NULL")); 1258 UNP_PCB_LOCK(unp); 1259 UNP_PCB_LOCK(unp2); 1260 error = unp_connect2(so, so2, PRU_CONNECT); 1261 UNP_PCB_UNLOCK(unp2); 1262 UNP_PCB_UNLOCK(unp); 1263 bad2: 1264 UNP_LINK_WUNLOCK(); 1265 if (vfslocked) 1266 /* 1267 * Giant has been previously acquired. This means filesystem 1268 * isn't MPSAFE. Do it once again. 1269 */ 1270 mtx_lock(&Giant); 1271 bad: 1272 if (vp != NULL) 1273 vput(vp); 1274 VFS_UNLOCK_GIANT(vfslocked); 1275 free(sa, M_SONAME); 1276 UNP_LINK_WLOCK(); 1277 UNP_PCB_LOCK(unp); 1278 unp->unp_flags &= ~UNP_CONNECTING; 1279 UNP_PCB_UNLOCK(unp); 1280 return (error); 1281 } 1282 1283 static int 1284 unp_connect2(struct socket *so, struct socket *so2, int req) 1285 { 1286 struct unpcb *unp; 1287 struct unpcb *unp2; 1288 1289 unp = sotounpcb(so); 1290 KASSERT(unp != NULL, ("unp_connect2: unp == NULL")); 1291 unp2 = sotounpcb(so2); 1292 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 1293 1294 UNP_LINK_WLOCK_ASSERT(); 1295 UNP_PCB_LOCK_ASSERT(unp); 1296 UNP_PCB_LOCK_ASSERT(unp2); 1297 1298 if (so2->so_type != so->so_type) 1299 return (EPROTOTYPE); 1300 unp->unp_conn = unp2; 1301 1302 switch (so->so_type) { 1303 case SOCK_DGRAM: 1304 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1305 soisconnected(so); 1306 break; 1307 1308 case SOCK_STREAM: 1309 unp2->unp_conn = unp; 1310 if (req == PRU_CONNECT && 1311 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1312 soisconnecting(so); 1313 else 1314 soisconnected(so); 1315 soisconnected(so2); 1316 break; 1317 1318 default: 1319 panic("unp_connect2"); 1320 } 1321 return (0); 1322 } 1323 1324 static void 1325 unp_disconnect(struct unpcb *unp, struct unpcb *unp2) 1326 { 1327 struct socket *so; 1328 1329 KASSERT(unp2 != NULL, ("unp_disconnect: unp2 == NULL")); 1330 1331 UNP_LINK_WLOCK_ASSERT(); 1332 UNP_PCB_LOCK_ASSERT(unp); 1333 UNP_PCB_LOCK_ASSERT(unp2); 1334 1335 unp->unp_conn = NULL; 1336 switch (unp->unp_socket->so_type) { 1337 case SOCK_DGRAM: 1338 LIST_REMOVE(unp, unp_reflink); 1339 so = unp->unp_socket; 1340 SOCK_LOCK(so); 1341 so->so_state &= ~SS_ISCONNECTED; 1342 SOCK_UNLOCK(so); 1343 break; 1344 1345 case SOCK_STREAM: 1346 soisdisconnected(unp->unp_socket); 1347 unp2->unp_conn = NULL; 1348 soisdisconnected(unp2->unp_socket); 1349 break; 1350 } 1351 } 1352 1353 /* 1354 * unp_pcblist() walks the global list of struct unpcb's to generate a 1355 * pointer list, bumping the refcount on each unpcb. It then copies them out 1356 * sequentially, validating the generation number on each to see if it has 1357 * been detached. All of this is necessary because copyout() may sleep on 1358 * disk I/O. 1359 */ 1360 static int 1361 unp_pcblist(SYSCTL_HANDLER_ARGS) 1362 { 1363 int error, i, n; 1364 int freeunp; 1365 struct unpcb *unp, **unp_list; 1366 unp_gen_t gencnt; 1367 struct xunpgen *xug; 1368 struct unp_head *head; 1369 struct xunpcb *xu; 1370 1371 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 1372 1373 /* 1374 * The process of preparing the PCB list is too time-consuming and 1375 * resource-intensive to repeat twice on every request. 1376 */ 1377 if (req->oldptr == NULL) { 1378 n = unp_count; 1379 req->oldidx = 2 * (sizeof *xug) 1380 + (n + n/8) * sizeof(struct xunpcb); 1381 return (0); 1382 } 1383 1384 if (req->newptr != NULL) 1385 return (EPERM); 1386 1387 /* 1388 * OK, now we're committed to doing something. 1389 */ 1390 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1391 UNP_LIST_LOCK(); 1392 gencnt = unp_gencnt; 1393 n = unp_count; 1394 UNP_LIST_UNLOCK(); 1395 1396 xug->xug_len = sizeof *xug; 1397 xug->xug_count = n; 1398 xug->xug_gen = gencnt; 1399 xug->xug_sogen = so_gencnt; 1400 error = SYSCTL_OUT(req, xug, sizeof *xug); 1401 if (error) { 1402 free(xug, M_TEMP); 1403 return (error); 1404 } 1405 1406 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1407 1408 UNP_LIST_LOCK(); 1409 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1410 unp = LIST_NEXT(unp, unp_link)) { 1411 UNP_PCB_LOCK(unp); 1412 if (unp->unp_gencnt <= gencnt) { 1413 if (cr_cansee(req->td->td_ucred, 1414 unp->unp_socket->so_cred)) { 1415 UNP_PCB_UNLOCK(unp); 1416 continue; 1417 } 1418 unp_list[i++] = unp; 1419 unp->unp_refcount++; 1420 } 1421 UNP_PCB_UNLOCK(unp); 1422 } 1423 UNP_LIST_UNLOCK(); 1424 n = i; /* In case we lost some during malloc. */ 1425 1426 error = 0; 1427 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1428 for (i = 0; i < n; i++) { 1429 unp = unp_list[i]; 1430 UNP_PCB_LOCK(unp); 1431 unp->unp_refcount--; 1432 if (unp->unp_refcount != 0 && unp->unp_gencnt <= gencnt) { 1433 xu->xu_len = sizeof *xu; 1434 xu->xu_unpp = unp; 1435 /* 1436 * XXX - need more locking here to protect against 1437 * connect/disconnect races for SMP. 1438 */ 1439 if (unp->unp_addr != NULL) 1440 bcopy(unp->unp_addr, &xu->xu_addr, 1441 unp->unp_addr->sun_len); 1442 if (unp->unp_conn != NULL && 1443 unp->unp_conn->unp_addr != NULL) 1444 bcopy(unp->unp_conn->unp_addr, 1445 &xu->xu_caddr, 1446 unp->unp_conn->unp_addr->sun_len); 1447 bcopy(unp, &xu->xu_unp, sizeof *unp); 1448 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1449 UNP_PCB_UNLOCK(unp); 1450 error = SYSCTL_OUT(req, xu, sizeof *xu); 1451 } else { 1452 freeunp = (unp->unp_refcount == 0); 1453 UNP_PCB_UNLOCK(unp); 1454 if (freeunp) { 1455 UNP_PCB_LOCK_DESTROY(unp); 1456 uma_zfree(unp_zone, unp); 1457 } 1458 } 1459 } 1460 free(xu, M_TEMP); 1461 if (!error) { 1462 /* 1463 * Give the user an updated idea of our state. If the 1464 * generation differs from what we told her before, she knows 1465 * that something happened while we were processing this 1466 * request, and it might be necessary to retry. 1467 */ 1468 xug->xug_gen = unp_gencnt; 1469 xug->xug_sogen = so_gencnt; 1470 xug->xug_count = unp_count; 1471 error = SYSCTL_OUT(req, xug, sizeof *xug); 1472 } 1473 free(unp_list, M_TEMP); 1474 free(xug, M_TEMP); 1475 return (error); 1476 } 1477 1478 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 1479 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1480 "List of active local datagram sockets"); 1481 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 1482 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1483 "List of active local stream sockets"); 1484 1485 static void 1486 unp_shutdown(struct unpcb *unp) 1487 { 1488 struct unpcb *unp2; 1489 struct socket *so; 1490 1491 UNP_LINK_WLOCK_ASSERT(); 1492 UNP_PCB_LOCK_ASSERT(unp); 1493 1494 unp2 = unp->unp_conn; 1495 if (unp->unp_socket->so_type == SOCK_STREAM && unp2 != NULL) { 1496 so = unp2->unp_socket; 1497 if (so != NULL) 1498 socantrcvmore(so); 1499 } 1500 } 1501 1502 static void 1503 unp_drop(struct unpcb *unp, int errno) 1504 { 1505 struct socket *so = unp->unp_socket; 1506 struct unpcb *unp2; 1507 1508 UNP_LINK_WLOCK_ASSERT(); 1509 UNP_PCB_LOCK_ASSERT(unp); 1510 1511 so->so_error = errno; 1512 unp2 = unp->unp_conn; 1513 if (unp2 == NULL) 1514 return; 1515 UNP_PCB_LOCK(unp2); 1516 unp_disconnect(unp, unp2); 1517 UNP_PCB_UNLOCK(unp2); 1518 } 1519 1520 static void 1521 unp_freerights(struct file **rp, int fdcount) 1522 { 1523 int i; 1524 struct file *fp; 1525 1526 for (i = 0; i < fdcount; i++) { 1527 fp = *rp; 1528 *rp++ = NULL; 1529 unp_discard(fp); 1530 } 1531 } 1532 1533 static int 1534 unp_externalize(struct mbuf *control, struct mbuf **controlp) 1535 { 1536 struct thread *td = curthread; /* XXX */ 1537 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1538 int i; 1539 int *fdp; 1540 struct file **rp; 1541 struct file *fp; 1542 void *data; 1543 socklen_t clen = control->m_len, datalen; 1544 int error, newfds; 1545 int f; 1546 u_int newlen; 1547 1548 UNP_LINK_UNLOCK_ASSERT(); 1549 1550 error = 0; 1551 if (controlp != NULL) /* controlp == NULL => free control messages */ 1552 *controlp = NULL; 1553 while (cm != NULL) { 1554 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1555 error = EINVAL; 1556 break; 1557 } 1558 data = CMSG_DATA(cm); 1559 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1560 if (cm->cmsg_level == SOL_SOCKET 1561 && cm->cmsg_type == SCM_RIGHTS) { 1562 newfds = datalen / sizeof(struct file *); 1563 rp = data; 1564 1565 /* If we're not outputting the descriptors free them. */ 1566 if (error || controlp == NULL) { 1567 unp_freerights(rp, newfds); 1568 goto next; 1569 } 1570 FILEDESC_XLOCK(td->td_proc->p_fd); 1571 /* if the new FD's will not fit free them. */ 1572 if (!fdavail(td, newfds)) { 1573 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1574 error = EMSGSIZE; 1575 unp_freerights(rp, newfds); 1576 goto next; 1577 } 1578 1579 /* 1580 * Now change each pointer to an fd in the global 1581 * table to an integer that is the index to the local 1582 * fd table entry that we set up to point to the 1583 * global one we are transferring. 1584 */ 1585 newlen = newfds * sizeof(int); 1586 *controlp = sbcreatecontrol(NULL, newlen, 1587 SCM_RIGHTS, SOL_SOCKET); 1588 if (*controlp == NULL) { 1589 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1590 error = E2BIG; 1591 unp_freerights(rp, newfds); 1592 goto next; 1593 } 1594 1595 fdp = (int *) 1596 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1597 for (i = 0; i < newfds; i++) { 1598 if (fdalloc(td, 0, &f)) 1599 panic("unp_externalize fdalloc failed"); 1600 fp = *rp++; 1601 td->td_proc->p_fd->fd_ofiles[f] = fp; 1602 unp_externalize_fp(fp); 1603 *fdp++ = f; 1604 } 1605 FILEDESC_XUNLOCK(td->td_proc->p_fd); 1606 } else { 1607 /* We can just copy anything else across. */ 1608 if (error || controlp == NULL) 1609 goto next; 1610 *controlp = sbcreatecontrol(NULL, datalen, 1611 cm->cmsg_type, cm->cmsg_level); 1612 if (*controlp == NULL) { 1613 error = ENOBUFS; 1614 goto next; 1615 } 1616 bcopy(data, 1617 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1618 datalen); 1619 } 1620 controlp = &(*controlp)->m_next; 1621 1622 next: 1623 if (CMSG_SPACE(datalen) < clen) { 1624 clen -= CMSG_SPACE(datalen); 1625 cm = (struct cmsghdr *) 1626 ((caddr_t)cm + CMSG_SPACE(datalen)); 1627 } else { 1628 clen = 0; 1629 cm = NULL; 1630 } 1631 } 1632 1633 m_freem(control); 1634 return (error); 1635 } 1636 1637 static void 1638 unp_zone_change(void *tag) 1639 { 1640 1641 uma_zone_set_max(unp_zone, maxsockets); 1642 } 1643 1644 static void 1645 unp_init(void) 1646 { 1647 1648 #ifdef VIMAGE 1649 if (!IS_DEFAULT_VNET(curvnet)) 1650 return; 1651 #endif 1652 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1653 NULL, NULL, UMA_ALIGN_PTR, 0); 1654 if (unp_zone == NULL) 1655 panic("unp_init"); 1656 uma_zone_set_max(unp_zone, maxsockets); 1657 EVENTHANDLER_REGISTER(maxsockets_change, unp_zone_change, 1658 NULL, EVENTHANDLER_PRI_ANY); 1659 LIST_INIT(&unp_dhead); 1660 LIST_INIT(&unp_shead); 1661 TASK_INIT(&unp_gc_task, 0, unp_gc, NULL); 1662 UNP_LINK_LOCK_INIT(); 1663 UNP_LIST_LOCK_INIT(); 1664 } 1665 1666 static int 1667 unp_internalize(struct mbuf **controlp, struct thread *td) 1668 { 1669 struct mbuf *control = *controlp; 1670 struct proc *p = td->td_proc; 1671 struct filedesc *fdescp = p->p_fd; 1672 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1673 struct cmsgcred *cmcred; 1674 struct file **rp; 1675 struct file *fp; 1676 struct timeval *tv; 1677 int i, fd, *fdp; 1678 void *data; 1679 socklen_t clen = control->m_len, datalen; 1680 int error, oldfds; 1681 u_int newlen; 1682 1683 UNP_LINK_UNLOCK_ASSERT(); 1684 1685 error = 0; 1686 *controlp = NULL; 1687 while (cm != NULL) { 1688 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1689 || cm->cmsg_len > clen) { 1690 error = EINVAL; 1691 goto out; 1692 } 1693 data = CMSG_DATA(cm); 1694 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1695 1696 switch (cm->cmsg_type) { 1697 /* 1698 * Fill in credential information. 1699 */ 1700 case SCM_CREDS: 1701 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1702 SCM_CREDS, SOL_SOCKET); 1703 if (*controlp == NULL) { 1704 error = ENOBUFS; 1705 goto out; 1706 } 1707 cmcred = (struct cmsgcred *) 1708 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1709 cmcred->cmcred_pid = p->p_pid; 1710 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1711 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1712 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1713 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1714 CMGROUP_MAX); 1715 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1716 cmcred->cmcred_groups[i] = 1717 td->td_ucred->cr_groups[i]; 1718 break; 1719 1720 case SCM_RIGHTS: 1721 oldfds = datalen / sizeof (int); 1722 /* 1723 * Check that all the FDs passed in refer to legal 1724 * files. If not, reject the entire operation. 1725 */ 1726 fdp = data; 1727 FILEDESC_SLOCK(fdescp); 1728 for (i = 0; i < oldfds; i++) { 1729 fd = *fdp++; 1730 if ((unsigned)fd >= fdescp->fd_nfiles || 1731 fdescp->fd_ofiles[fd] == NULL) { 1732 FILEDESC_SUNLOCK(fdescp); 1733 error = EBADF; 1734 goto out; 1735 } 1736 fp = fdescp->fd_ofiles[fd]; 1737 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1738 FILEDESC_SUNLOCK(fdescp); 1739 error = EOPNOTSUPP; 1740 goto out; 1741 } 1742 1743 } 1744 1745 /* 1746 * Now replace the integer FDs with pointers to the 1747 * associated global file table entry.. 1748 */ 1749 newlen = oldfds * sizeof(struct file *); 1750 *controlp = sbcreatecontrol(NULL, newlen, 1751 SCM_RIGHTS, SOL_SOCKET); 1752 if (*controlp == NULL) { 1753 FILEDESC_SUNLOCK(fdescp); 1754 error = E2BIG; 1755 goto out; 1756 } 1757 fdp = data; 1758 rp = (struct file **) 1759 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1760 for (i = 0; i < oldfds; i++) { 1761 fp = fdescp->fd_ofiles[*fdp++]; 1762 *rp++ = fp; 1763 unp_internalize_fp(fp); 1764 } 1765 FILEDESC_SUNLOCK(fdescp); 1766 break; 1767 1768 case SCM_TIMESTAMP: 1769 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1770 SCM_TIMESTAMP, SOL_SOCKET); 1771 if (*controlp == NULL) { 1772 error = ENOBUFS; 1773 goto out; 1774 } 1775 tv = (struct timeval *) 1776 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1777 microtime(tv); 1778 break; 1779 1780 default: 1781 error = EINVAL; 1782 goto out; 1783 } 1784 1785 controlp = &(*controlp)->m_next; 1786 if (CMSG_SPACE(datalen) < clen) { 1787 clen -= CMSG_SPACE(datalen); 1788 cm = (struct cmsghdr *) 1789 ((caddr_t)cm + CMSG_SPACE(datalen)); 1790 } else { 1791 clen = 0; 1792 cm = NULL; 1793 } 1794 } 1795 1796 out: 1797 m_freem(control); 1798 return (error); 1799 } 1800 1801 static struct mbuf * 1802 unp_addsockcred(struct thread *td, struct mbuf *control) 1803 { 1804 struct mbuf *m, *n, *n_prev; 1805 struct sockcred *sc; 1806 const struct cmsghdr *cm; 1807 int ngroups; 1808 int i; 1809 1810 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 1811 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 1812 if (m == NULL) 1813 return (control); 1814 1815 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 1816 sc->sc_uid = td->td_ucred->cr_ruid; 1817 sc->sc_euid = td->td_ucred->cr_uid; 1818 sc->sc_gid = td->td_ucred->cr_rgid; 1819 sc->sc_egid = td->td_ucred->cr_gid; 1820 sc->sc_ngroups = ngroups; 1821 for (i = 0; i < sc->sc_ngroups; i++) 1822 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 1823 1824 /* 1825 * Unlink SCM_CREDS control messages (struct cmsgcred), since just 1826 * created SCM_CREDS control message (struct sockcred) has another 1827 * format. 1828 */ 1829 if (control != NULL) 1830 for (n = control, n_prev = NULL; n != NULL;) { 1831 cm = mtod(n, struct cmsghdr *); 1832 if (cm->cmsg_level == SOL_SOCKET && 1833 cm->cmsg_type == SCM_CREDS) { 1834 if (n_prev == NULL) 1835 control = n->m_next; 1836 else 1837 n_prev->m_next = n->m_next; 1838 n = m_free(n); 1839 } else { 1840 n_prev = n; 1841 n = n->m_next; 1842 } 1843 } 1844 1845 /* Prepend it to the head. */ 1846 m->m_next = control; 1847 return (m); 1848 } 1849 1850 static struct unpcb * 1851 fptounp(struct file *fp) 1852 { 1853 struct socket *so; 1854 1855 if (fp->f_type != DTYPE_SOCKET) 1856 return (NULL); 1857 if ((so = fp->f_data) == NULL) 1858 return (NULL); 1859 if (so->so_proto->pr_domain != &localdomain) 1860 return (NULL); 1861 return sotounpcb(so); 1862 } 1863 1864 static void 1865 unp_discard(struct file *fp) 1866 { 1867 1868 unp_externalize_fp(fp); 1869 (void) closef(fp, (struct thread *)NULL); 1870 } 1871 1872 static void 1873 unp_internalize_fp(struct file *fp) 1874 { 1875 struct unpcb *unp; 1876 1877 UNP_LINK_WLOCK(); 1878 if ((unp = fptounp(fp)) != NULL) { 1879 unp->unp_file = fp; 1880 unp->unp_msgcount++; 1881 } 1882 fhold(fp); 1883 unp_rights++; 1884 UNP_LINK_WUNLOCK(); 1885 } 1886 1887 static void 1888 unp_externalize_fp(struct file *fp) 1889 { 1890 struct unpcb *unp; 1891 1892 UNP_LINK_WLOCK(); 1893 if ((unp = fptounp(fp)) != NULL) 1894 unp->unp_msgcount--; 1895 unp_rights--; 1896 UNP_LINK_WUNLOCK(); 1897 } 1898 1899 /* 1900 * unp_defer indicates whether additional work has been defered for a future 1901 * pass through unp_gc(). It is thread local and does not require explicit 1902 * synchronization. 1903 */ 1904 static int unp_marked; 1905 static int unp_unreachable; 1906 1907 static void 1908 unp_accessable(struct file *fp) 1909 { 1910 struct unpcb *unp; 1911 1912 if ((unp = fptounp(fp)) == NULL) 1913 return; 1914 if (unp->unp_gcflag & UNPGC_REF) 1915 return; 1916 unp->unp_gcflag &= ~UNPGC_DEAD; 1917 unp->unp_gcflag |= UNPGC_REF; 1918 unp_marked++; 1919 } 1920 1921 static void 1922 unp_gc_process(struct unpcb *unp) 1923 { 1924 struct socket *soa; 1925 struct socket *so; 1926 struct file *fp; 1927 1928 /* Already processed. */ 1929 if (unp->unp_gcflag & UNPGC_SCANNED) 1930 return; 1931 fp = unp->unp_file; 1932 1933 /* 1934 * Check for a socket potentially in a cycle. It must be in a 1935 * queue as indicated by msgcount, and this must equal the file 1936 * reference count. Note that when msgcount is 0 the file is NULL. 1937 */ 1938 if ((unp->unp_gcflag & UNPGC_REF) == 0 && fp && 1939 unp->unp_msgcount != 0 && fp->f_count == unp->unp_msgcount) { 1940 unp->unp_gcflag |= UNPGC_DEAD; 1941 unp_unreachable++; 1942 return; 1943 } 1944 1945 /* 1946 * Mark all sockets we reference with RIGHTS. 1947 */ 1948 so = unp->unp_socket; 1949 SOCKBUF_LOCK(&so->so_rcv); 1950 unp_scan(so->so_rcv.sb_mb, unp_accessable); 1951 SOCKBUF_UNLOCK(&so->so_rcv); 1952 1953 /* 1954 * Mark all sockets in our accept queue. 1955 */ 1956 ACCEPT_LOCK(); 1957 TAILQ_FOREACH(soa, &so->so_comp, so_list) { 1958 SOCKBUF_LOCK(&soa->so_rcv); 1959 unp_scan(soa->so_rcv.sb_mb, unp_accessable); 1960 SOCKBUF_UNLOCK(&soa->so_rcv); 1961 } 1962 ACCEPT_UNLOCK(); 1963 unp->unp_gcflag |= UNPGC_SCANNED; 1964 } 1965 1966 static int unp_recycled; 1967 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, 1968 "Number of unreachable sockets claimed by the garbage collector."); 1969 1970 static int unp_taskcount; 1971 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, 1972 "Number of times the garbage collector has run."); 1973 1974 static void 1975 unp_gc(__unused void *arg, int pending) 1976 { 1977 struct unp_head *heads[] = { &unp_dhead, &unp_shead, NULL }; 1978 struct unp_head **head; 1979 struct file **unref; 1980 struct unpcb *unp; 1981 int i; 1982 1983 unp_taskcount++; 1984 UNP_LIST_LOCK(); 1985 /* 1986 * First clear all gc flags from previous runs. 1987 */ 1988 for (head = heads; *head != NULL; head++) 1989 LIST_FOREACH(unp, *head, unp_link) 1990 unp->unp_gcflag = 0; 1991 1992 /* 1993 * Scan marking all reachable sockets with UNPGC_REF. Once a socket 1994 * is reachable all of the sockets it references are reachable. 1995 * Stop the scan once we do a complete loop without discovering 1996 * a new reachable socket. 1997 */ 1998 do { 1999 unp_unreachable = 0; 2000 unp_marked = 0; 2001 for (head = heads; *head != NULL; head++) 2002 LIST_FOREACH(unp, *head, unp_link) 2003 unp_gc_process(unp); 2004 } while (unp_marked); 2005 UNP_LIST_UNLOCK(); 2006 if (unp_unreachable == 0) 2007 return; 2008 2009 /* 2010 * Allocate space for a local list of dead unpcbs. 2011 */ 2012 unref = malloc(unp_unreachable * sizeof(struct file *), 2013 M_TEMP, M_WAITOK); 2014 2015 /* 2016 * Iterate looking for sockets which have been specifically marked 2017 * as as unreachable and store them locally. 2018 */ 2019 UNP_LIST_LOCK(); 2020 for (i = 0, head = heads; *head != NULL; head++) 2021 LIST_FOREACH(unp, *head, unp_link) 2022 if (unp->unp_gcflag & UNPGC_DEAD) { 2023 unref[i++] = unp->unp_file; 2024 fhold(unp->unp_file); 2025 KASSERT(unp->unp_file != NULL, 2026 ("unp_gc: Invalid unpcb.")); 2027 KASSERT(i <= unp_unreachable, 2028 ("unp_gc: incorrect unreachable count.")); 2029 } 2030 UNP_LIST_UNLOCK(); 2031 2032 /* 2033 * Now flush all sockets, free'ing rights. This will free the 2034 * struct files associated with these sockets but leave each socket 2035 * with one remaining ref. 2036 */ 2037 for (i = 0; i < unp_unreachable; i++) 2038 sorflush(unref[i]->f_data); 2039 2040 /* 2041 * And finally release the sockets so they can be reclaimed. 2042 */ 2043 for (i = 0; i < unp_unreachable; i++) 2044 fdrop(unref[i], NULL); 2045 unp_recycled += unp_unreachable; 2046 free(unref, M_TEMP); 2047 } 2048 2049 static void 2050 unp_dispose(struct mbuf *m) 2051 { 2052 2053 if (m) 2054 unp_scan(m, unp_discard); 2055 } 2056 2057 static void 2058 unp_scan(struct mbuf *m0, void (*op)(struct file *)) 2059 { 2060 struct mbuf *m; 2061 struct file **rp; 2062 struct cmsghdr *cm; 2063 void *data; 2064 int i; 2065 socklen_t clen, datalen; 2066 int qfds; 2067 2068 while (m0 != NULL) { 2069 for (m = m0; m; m = m->m_next) { 2070 if (m->m_type != MT_CONTROL) 2071 continue; 2072 2073 cm = mtod(m, struct cmsghdr *); 2074 clen = m->m_len; 2075 2076 while (cm != NULL) { 2077 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 2078 break; 2079 2080 data = CMSG_DATA(cm); 2081 datalen = (caddr_t)cm + cm->cmsg_len 2082 - (caddr_t)data; 2083 2084 if (cm->cmsg_level == SOL_SOCKET && 2085 cm->cmsg_type == SCM_RIGHTS) { 2086 qfds = datalen / sizeof (struct file *); 2087 rp = data; 2088 for (i = 0; i < qfds; i++) 2089 (*op)(*rp++); 2090 } 2091 2092 if (CMSG_SPACE(datalen) < clen) { 2093 clen -= CMSG_SPACE(datalen); 2094 cm = (struct cmsghdr *) 2095 ((caddr_t)cm + CMSG_SPACE(datalen)); 2096 } else { 2097 clen = 0; 2098 cm = NULL; 2099 } 2100 } 2101 } 2102 m0 = m0->m_act; 2103 } 2104 } 2105 2106 #ifdef DDB 2107 static void 2108 db_print_indent(int indent) 2109 { 2110 int i; 2111 2112 for (i = 0; i < indent; i++) 2113 db_printf(" "); 2114 } 2115 2116 static void 2117 db_print_unpflags(int unp_flags) 2118 { 2119 int comma; 2120 2121 comma = 0; 2122 if (unp_flags & UNP_HAVEPC) { 2123 db_printf("%sUNP_HAVEPC", comma ? ", " : ""); 2124 comma = 1; 2125 } 2126 if (unp_flags & UNP_HAVEPCCACHED) { 2127 db_printf("%sUNP_HAVEPCCACHED", comma ? ", " : ""); 2128 comma = 1; 2129 } 2130 if (unp_flags & UNP_WANTCRED) { 2131 db_printf("%sUNP_WANTCRED", comma ? ", " : ""); 2132 comma = 1; 2133 } 2134 if (unp_flags & UNP_CONNWAIT) { 2135 db_printf("%sUNP_CONNWAIT", comma ? ", " : ""); 2136 comma = 1; 2137 } 2138 if (unp_flags & UNP_CONNECTING) { 2139 db_printf("%sUNP_CONNECTING", comma ? ", " : ""); 2140 comma = 1; 2141 } 2142 if (unp_flags & UNP_BINDING) { 2143 db_printf("%sUNP_BINDING", comma ? ", " : ""); 2144 comma = 1; 2145 } 2146 } 2147 2148 static void 2149 db_print_xucred(int indent, struct xucred *xu) 2150 { 2151 int comma, i; 2152 2153 db_print_indent(indent); 2154 db_printf("cr_version: %u cr_uid: %u cr_ngroups: %d\n", 2155 xu->cr_version, xu->cr_uid, xu->cr_ngroups); 2156 db_print_indent(indent); 2157 db_printf("cr_groups: "); 2158 comma = 0; 2159 for (i = 0; i < xu->cr_ngroups; i++) { 2160 db_printf("%s%u", comma ? ", " : "", xu->cr_groups[i]); 2161 comma = 1; 2162 } 2163 db_printf("\n"); 2164 } 2165 2166 static void 2167 db_print_unprefs(int indent, struct unp_head *uh) 2168 { 2169 struct unpcb *unp; 2170 int counter; 2171 2172 counter = 0; 2173 LIST_FOREACH(unp, uh, unp_reflink) { 2174 if (counter % 4 == 0) 2175 db_print_indent(indent); 2176 db_printf("%p ", unp); 2177 if (counter % 4 == 3) 2178 db_printf("\n"); 2179 counter++; 2180 } 2181 if (counter != 0 && counter % 4 != 0) 2182 db_printf("\n"); 2183 } 2184 2185 DB_SHOW_COMMAND(unpcb, db_show_unpcb) 2186 { 2187 struct unpcb *unp; 2188 2189 if (!have_addr) { 2190 db_printf("usage: show unpcb <addr>\n"); 2191 return; 2192 } 2193 unp = (struct unpcb *)addr; 2194 2195 db_printf("unp_socket: %p unp_vnode: %p\n", unp->unp_socket, 2196 unp->unp_vnode); 2197 2198 db_printf("unp_ino: %d unp_conn: %p\n", unp->unp_ino, 2199 unp->unp_conn); 2200 2201 db_printf("unp_refs:\n"); 2202 db_print_unprefs(2, &unp->unp_refs); 2203 2204 /* XXXRW: Would be nice to print the full address, if any. */ 2205 db_printf("unp_addr: %p\n", unp->unp_addr); 2206 2207 db_printf("unp_cc: %d unp_mbcnt: %d unp_gencnt: %llu\n", 2208 unp->unp_cc, unp->unp_mbcnt, 2209 (unsigned long long)unp->unp_gencnt); 2210 2211 db_printf("unp_flags: %x (", unp->unp_flags); 2212 db_print_unpflags(unp->unp_flags); 2213 db_printf(")\n"); 2214 2215 db_printf("unp_peercred:\n"); 2216 db_print_xucred(2, &unp->unp_peercred); 2217 2218 db_printf("unp_refcount: %u\n", unp->unp_refcount); 2219 } 2220 #endif
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