1 /*- 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. 4 * Copyright 2004-2006 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 #include <sys/cdefs.h> 35 __FBSDID("$FreeBSD$"); 36 37 #include "opt_mac.h" 38 39 #include <sys/param.h> 40 #include <sys/domain.h> 41 #include <sys/fcntl.h> 42 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 43 #include <sys/file.h> 44 #include <sys/filedesc.h> 45 #include <sys/jail.h> 46 #include <sys/kernel.h> 47 #include <sys/lock.h> 48 #include <sys/mac.h> 49 #include <sys/mbuf.h> 50 #include <sys/mount.h> 51 #include <sys/mutex.h> 52 #include <sys/namei.h> 53 #include <sys/proc.h> 54 #include <sys/protosw.h> 55 #include <sys/resourcevar.h> 56 #include <sys/socket.h> 57 #include <sys/socketvar.h> 58 #include <sys/signalvar.h> 59 #include <sys/stat.h> 60 #include <sys/sx.h> 61 #include <sys/sysctl.h> 62 #include <sys/systm.h> 63 #include <sys/taskqueue.h> 64 #include <sys/un.h> 65 #include <sys/unpcb.h> 66 #include <sys/vnode.h> 67 68 #include <vm/uma.h> 69 70 static uma_zone_t unp_zone; 71 static unp_gen_t unp_gencnt; 72 static u_int unp_count; 73 74 static struct unp_head unp_shead, unp_dhead; 75 76 /* 77 * Unix communications domain. 78 * 79 * TODO: 80 * SEQPACKET, RDM 81 * rethink name space problems 82 * need a proper out-of-band 83 * lock pushdown 84 */ 85 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 86 static ino_t unp_ino; /* prototype for fake inode numbers */ 87 struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 88 89 /* 90 * Currently, UNIX domain sockets are protected by a single subsystem lock, 91 * which covers global data structures and variables, the contents of each 92 * per-socket unpcb structure, and the so_pcb field in sockets attached to 93 * the UNIX domain. This provides for a moderate degree of paralellism, as 94 * receive operations on UNIX domain sockets do not need to acquire the 95 * subsystem lock. Finer grained locking to permit send() without acquiring 96 * a global lock would be a logical next step. 97 * 98 * The UNIX domain socket lock preceds all socket layer locks, including the 99 * socket lock and socket buffer lock, permitting UNIX domain socket code to 100 * call into socket support routines without releasing its locks. 101 * 102 * Some caution is required in areas where the UNIX domain socket code enters 103 * VFS in order to create or find rendezvous points. This results in 104 * dropping of the UNIX domain socket subsystem lock, acquisition of the 105 * Giant lock, and potential sleeping. This increases the chances of races, 106 * and exposes weaknesses in the socket->protocol API by offering poor 107 * failure modes. 108 */ 109 static struct mtx unp_mtx; 110 #define UNP_LOCK_INIT() \ 111 mtx_init(&unp_mtx, "unp", NULL, MTX_DEF) 112 #define UNP_LOCK() mtx_lock(&unp_mtx) 113 #define UNP_UNLOCK() mtx_unlock(&unp_mtx) 114 #define UNP_LOCK_ASSERT() mtx_assert(&unp_mtx, MA_OWNED) 115 #define UNP_UNLOCK_ASSERT() mtx_assert(&unp_mtx, MA_NOTOWNED) 116 117 /* 118 * Garbage collection of cyclic file descriptor/socket references occurs 119 * asynchronously in a taskqueue context in order to avoid recursion and 120 * reentrance in the UNIX domain socket, file descriptor, and socket layer 121 * code. See unp_gc() for a full description. 122 */ 123 static struct task unp_gc_task; 124 125 static int unp_attach(struct socket *); 126 static void unp_detach(struct unpcb *); 127 static int unp_bind(struct unpcb *,struct sockaddr *, struct thread *); 128 static int unp_connect(struct socket *,struct sockaddr *, struct thread *); 129 static int unp_connect2(struct socket *so, struct socket *so2, int); 130 static void unp_disconnect(struct unpcb *); 131 static void unp_shutdown(struct unpcb *); 132 static void unp_drop(struct unpcb *, int); 133 static void unp_gc(__unused void *, int); 134 static void unp_scan(struct mbuf *, void (*)(struct file *)); 135 static void unp_mark(struct file *); 136 static void unp_discard(struct file *); 137 static void unp_freerights(struct file **, int); 138 static int unp_internalize(struct mbuf **, struct thread *); 139 static int unp_listen(struct socket *, struct unpcb *, int, 140 struct thread *); 141 142 static void 143 uipc_abort(struct socket *so) 144 { 145 struct unpcb *unp; 146 147 unp = sotounpcb(so); 148 KASSERT(unp != NULL, ("uipc_abort: unp == NULL")); 149 UNP_LOCK(); 150 unp_drop(unp, ECONNABORTED); 151 unp_detach(unp); 152 UNP_UNLOCK_ASSERT(); 153 } 154 155 static int 156 uipc_accept(struct socket *so, struct sockaddr **nam) 157 { 158 struct unpcb *unp; 159 const struct sockaddr *sa; 160 161 /* 162 * Pass back name of connected socket, 163 * if it was bound and we are still connected 164 * (our peer may have closed already!). 165 */ 166 unp = sotounpcb(so); 167 KASSERT(unp != NULL, ("uipc_accept: unp == NULL")); 168 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 169 UNP_LOCK(); 170 if (unp->unp_conn != NULL && unp->unp_conn->unp_addr != NULL) 171 sa = (struct sockaddr *) unp->unp_conn->unp_addr; 172 else 173 sa = &sun_noname; 174 bcopy(sa, *nam, sa->sa_len); 175 UNP_UNLOCK(); 176 return (0); 177 } 178 179 static int 180 uipc_attach(struct socket *so, int proto, struct thread *td) 181 { 182 183 return (unp_attach(so)); 184 } 185 186 static int 187 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 188 { 189 struct unpcb *unp; 190 int error; 191 192 unp = sotounpcb(so); 193 KASSERT(unp != NULL, ("uipc_bind: unp == NULL")); 194 UNP_LOCK(); 195 error = unp_bind(unp, nam, td); 196 UNP_UNLOCK(); 197 return (error); 198 } 199 200 static int 201 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 202 { 203 struct unpcb *unp; 204 int error; 205 206 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 207 unp = sotounpcb(so); 208 KASSERT(unp != NULL, ("uipc_connect: unp == NULL")); 209 UNP_LOCK(); 210 error = unp_connect(so, nam, td); 211 UNP_UNLOCK(); 212 return (error); 213 } 214 215 int 216 uipc_connect2(struct socket *so1, struct socket *so2) 217 { 218 struct unpcb *unp; 219 int error; 220 221 unp = sotounpcb(so1); 222 KASSERT(unp != NULL, ("uipc_connect2: unp == NULL")); 223 UNP_LOCK(); 224 error = unp_connect2(so1, so2, PRU_CONNECT2); 225 UNP_UNLOCK(); 226 return (error); 227 } 228 229 /* control is EOPNOTSUPP */ 230 231 static void 232 uipc_detach(struct socket *so) 233 { 234 struct unpcb *unp; 235 236 unp = sotounpcb(so); 237 KASSERT(unp != NULL, ("uipc_detach: unp == NULL")); 238 UNP_LOCK(); 239 unp_detach(unp); 240 UNP_UNLOCK_ASSERT(); 241 } 242 243 static int 244 uipc_disconnect(struct socket *so) 245 { 246 struct unpcb *unp; 247 248 unp = sotounpcb(so); 249 KASSERT(unp != NULL, ("uipc_disconnect: unp == NULL")); 250 UNP_LOCK(); 251 unp_disconnect(unp); 252 UNP_UNLOCK(); 253 return (0); 254 } 255 256 static int 257 uipc_listen(struct socket *so, int backlog, struct thread *td) 258 { 259 struct unpcb *unp; 260 int error; 261 262 unp = sotounpcb(so); 263 KASSERT(unp != NULL, ("uipc_listen: unp == NULL")); 264 UNP_LOCK(); 265 if (unp->unp_vnode == NULL) { 266 UNP_UNLOCK(); 267 return (EINVAL); 268 } 269 error = unp_listen(so, unp, backlog, td); 270 UNP_UNLOCK(); 271 return (error); 272 } 273 274 static int 275 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 276 { 277 struct unpcb *unp; 278 const struct sockaddr *sa; 279 280 unp = sotounpcb(so); 281 KASSERT(unp != NULL, ("uipc_peeraddr: unp == NULL")); 282 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 283 UNP_LOCK(); 284 if (unp->unp_conn != NULL && unp->unp_conn->unp_addr!= NULL) 285 sa = (struct sockaddr *) unp->unp_conn->unp_addr; 286 else { 287 /* 288 * XXX: It seems that this test always fails even when 289 * connection is established. So, this else clause is 290 * added as workaround to return PF_LOCAL sockaddr. 291 */ 292 sa = &sun_noname; 293 } 294 bcopy(sa, *nam, sa->sa_len); 295 UNP_UNLOCK(); 296 return (0); 297 } 298 299 static int 300 uipc_rcvd(struct socket *so, int flags) 301 { 302 struct unpcb *unp; 303 struct socket *so2; 304 u_long newhiwat; 305 306 unp = sotounpcb(so); 307 KASSERT(unp != NULL, ("uipc_rcvd: unp == NULL")); 308 UNP_LOCK(); 309 switch (so->so_type) { 310 case SOCK_DGRAM: 311 panic("uipc_rcvd DGRAM?"); 312 /*NOTREACHED*/ 313 314 case SOCK_STREAM: 315 if (unp->unp_conn == NULL) 316 break; 317 so2 = unp->unp_conn->unp_socket; 318 SOCKBUF_LOCK(&so2->so_snd); 319 SOCKBUF_LOCK(&so->so_rcv); 320 /* 321 * Adjust backpressure on sender 322 * and wakeup any waiting to write. 323 */ 324 so2->so_snd.sb_mbmax += unp->unp_mbcnt - so->so_rcv.sb_mbcnt; 325 unp->unp_mbcnt = so->so_rcv.sb_mbcnt; 326 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - 327 so->so_rcv.sb_cc; 328 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, 329 newhiwat, RLIM_INFINITY); 330 unp->unp_cc = so->so_rcv.sb_cc; 331 SOCKBUF_UNLOCK(&so->so_rcv); 332 sowwakeup_locked(so2); 333 break; 334 335 default: 336 panic("uipc_rcvd unknown socktype"); 337 } 338 UNP_UNLOCK(); 339 return (0); 340 } 341 342 /* pru_rcvoob is EOPNOTSUPP */ 343 344 static int 345 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 346 struct mbuf *control, struct thread *td) 347 { 348 int error = 0; 349 struct unpcb *unp; 350 struct socket *so2; 351 u_long newhiwat; 352 353 unp = sotounpcb(so); 354 KASSERT(unp != NULL, ("uipc_send: unp == NULL")); 355 if (flags & PRUS_OOB) { 356 error = EOPNOTSUPP; 357 goto release; 358 } 359 360 if (control != NULL && (error = unp_internalize(&control, td))) 361 goto release; 362 363 UNP_LOCK(); 364 switch (so->so_type) { 365 case SOCK_DGRAM: 366 { 367 const struct sockaddr *from; 368 369 if (nam != NULL) { 370 if (unp->unp_conn != NULL) { 371 error = EISCONN; 372 break; 373 } 374 error = unp_connect(so, nam, td); 375 if (error) 376 break; 377 } else { 378 if (unp->unp_conn == NULL) { 379 error = ENOTCONN; 380 break; 381 } 382 } 383 so2 = unp->unp_conn->unp_socket; 384 if (unp->unp_addr != NULL) 385 from = (struct sockaddr *)unp->unp_addr; 386 else 387 from = &sun_noname; 388 if (unp->unp_conn->unp_flags & UNP_WANTCRED) 389 control = unp_addsockcred(td, control); 390 SOCKBUF_LOCK(&so2->so_rcv); 391 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) { 392 sorwakeup_locked(so2); 393 m = NULL; 394 control = NULL; 395 } else { 396 SOCKBUF_UNLOCK(&so2->so_rcv); 397 error = ENOBUFS; 398 } 399 if (nam != NULL) 400 unp_disconnect(unp); 401 break; 402 } 403 404 case SOCK_STREAM: 405 /* Connect if not connected yet. */ 406 /* 407 * Note: A better implementation would complain 408 * if not equal to the peer's address. 409 */ 410 if ((so->so_state & SS_ISCONNECTED) == 0) { 411 if (nam != NULL) { 412 error = unp_connect(so, nam, td); 413 if (error) 414 break; /* XXX */ 415 } else { 416 error = ENOTCONN; 417 break; 418 } 419 } 420 421 SOCKBUF_LOCK(&so->so_snd); 422 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 423 SOCKBUF_UNLOCK(&so->so_snd); 424 error = EPIPE; 425 break; 426 } 427 if (unp->unp_conn == NULL) 428 panic("uipc_send connected but no connection?"); 429 so2 = unp->unp_conn->unp_socket; 430 SOCKBUF_LOCK(&so2->so_rcv); 431 if (unp->unp_conn->unp_flags & UNP_WANTCRED) { 432 /* 433 * Credentials are passed only once on 434 * SOCK_STREAM. 435 */ 436 unp->unp_conn->unp_flags &= ~UNP_WANTCRED; 437 control = unp_addsockcred(td, control); 438 } 439 /* 440 * Send to paired receive port, and then reduce 441 * send buffer hiwater marks to maintain backpressure. 442 * Wake up readers. 443 */ 444 if (control != NULL) { 445 if (sbappendcontrol_locked(&so2->so_rcv, m, control)) 446 control = NULL; 447 } else { 448 sbappend_locked(&so2->so_rcv, m); 449 } 450 so->so_snd.sb_mbmax -= 451 so2->so_rcv.sb_mbcnt - unp->unp_conn->unp_mbcnt; 452 unp->unp_conn->unp_mbcnt = so2->so_rcv.sb_mbcnt; 453 newhiwat = so->so_snd.sb_hiwat - 454 (so2->so_rcv.sb_cc - unp->unp_conn->unp_cc); 455 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, 456 newhiwat, RLIM_INFINITY); 457 SOCKBUF_UNLOCK(&so->so_snd); 458 unp->unp_conn->unp_cc = so2->so_rcv.sb_cc; 459 sorwakeup_locked(so2); 460 m = NULL; 461 break; 462 463 default: 464 panic("uipc_send unknown socktype"); 465 } 466 467 /* 468 * SEND_EOF is equivalent to a SEND followed by 469 * a SHUTDOWN. 470 */ 471 if (flags & PRUS_EOF) { 472 socantsendmore(so); 473 unp_shutdown(unp); 474 } 475 UNP_UNLOCK(); 476 477 if (control != NULL && error != 0) 478 unp_dispose(control); 479 480 release: 481 if (control != NULL) 482 m_freem(control); 483 if (m != NULL) 484 m_freem(m); 485 return (error); 486 } 487 488 static int 489 uipc_sense(struct socket *so, struct stat *sb) 490 { 491 struct unpcb *unp; 492 struct socket *so2; 493 494 unp = sotounpcb(so); 495 KASSERT(unp != NULL, ("uipc_sense: unp == NULL")); 496 UNP_LOCK(); 497 sb->st_blksize = so->so_snd.sb_hiwat; 498 if (so->so_type == SOCK_STREAM && unp->unp_conn != NULL) { 499 so2 = unp->unp_conn->unp_socket; 500 sb->st_blksize += so2->so_rcv.sb_cc; 501 } 502 sb->st_dev = NODEV; 503 if (unp->unp_ino == 0) 504 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 505 sb->st_ino = unp->unp_ino; 506 UNP_UNLOCK(); 507 return (0); 508 } 509 510 static int 511 uipc_shutdown(struct socket *so) 512 { 513 struct unpcb *unp; 514 515 unp = sotounpcb(so); 516 KASSERT(unp != NULL, ("uipc_shutdown: unp == NULL")); 517 UNP_LOCK(); 518 socantsendmore(so); 519 unp_shutdown(unp); 520 UNP_UNLOCK(); 521 return (0); 522 } 523 524 static int 525 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 526 { 527 struct unpcb *unp; 528 const struct sockaddr *sa; 529 530 unp = sotounpcb(so); 531 KASSERT(unp != NULL, ("uipc_sockaddr: unp == NULL")); 532 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 533 UNP_LOCK(); 534 if (unp->unp_addr != NULL) 535 sa = (struct sockaddr *) unp->unp_addr; 536 else 537 sa = &sun_noname; 538 bcopy(sa, *nam, sa->sa_len); 539 UNP_UNLOCK(); 540 return (0); 541 } 542 543 struct pr_usrreqs uipc_usrreqs = { 544 .pru_abort = uipc_abort, 545 .pru_accept = uipc_accept, 546 .pru_attach = uipc_attach, 547 .pru_bind = uipc_bind, 548 .pru_connect = uipc_connect, 549 .pru_connect2 = uipc_connect2, 550 .pru_detach = uipc_detach, 551 .pru_disconnect = uipc_disconnect, 552 .pru_listen = uipc_listen, 553 .pru_peeraddr = uipc_peeraddr, 554 .pru_rcvd = uipc_rcvd, 555 .pru_send = uipc_send, 556 .pru_sense = uipc_sense, 557 .pru_shutdown = uipc_shutdown, 558 .pru_sockaddr = uipc_sockaddr, 559 .pru_sosend = sosend, 560 .pru_soreceive = soreceive, 561 .pru_sopoll = sopoll, 562 }; 563 564 int 565 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 566 { 567 struct unpcb *unp; 568 struct xucred xu; 569 int error, optval; 570 571 if (sopt->sopt_level != 0) 572 return (EINVAL); 573 574 unp = sotounpcb(so); 575 KASSERT(unp != NULL, ("uipc_ctloutput: unp == NULL")); 576 UNP_LOCK(); 577 error = 0; 578 switch (sopt->sopt_dir) { 579 case SOPT_GET: 580 switch (sopt->sopt_name) { 581 case LOCAL_PEERCRED: 582 if (unp->unp_flags & UNP_HAVEPC) 583 xu = unp->unp_peercred; 584 else { 585 if (so->so_type == SOCK_STREAM) 586 error = ENOTCONN; 587 else 588 error = EINVAL; 589 } 590 if (error == 0) 591 error = sooptcopyout(sopt, &xu, sizeof(xu)); 592 break; 593 case LOCAL_CREDS: 594 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 595 error = sooptcopyout(sopt, &optval, sizeof(optval)); 596 break; 597 case LOCAL_CONNWAIT: 598 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 599 error = sooptcopyout(sopt, &optval, sizeof(optval)); 600 break; 601 default: 602 error = EOPNOTSUPP; 603 break; 604 } 605 break; 606 case SOPT_SET: 607 switch (sopt->sopt_name) { 608 case LOCAL_CREDS: 609 case LOCAL_CONNWAIT: 610 error = sooptcopyin(sopt, &optval, sizeof(optval), 611 sizeof(optval)); 612 if (error) 613 break; 614 615 #define OPTSET(bit) \ 616 if (optval) \ 617 unp->unp_flags |= bit; \ 618 else \ 619 unp->unp_flags &= ~bit; 620 621 switch (sopt->sopt_name) { 622 case LOCAL_CREDS: 623 OPTSET(UNP_WANTCRED); 624 break; 625 case LOCAL_CONNWAIT: 626 OPTSET(UNP_CONNWAIT); 627 break; 628 default: 629 break; 630 } 631 break; 632 #undef OPTSET 633 default: 634 error = ENOPROTOOPT; 635 break; 636 } 637 break; 638 default: 639 error = EOPNOTSUPP; 640 break; 641 } 642 UNP_UNLOCK(); 643 return (error); 644 } 645 646 /* 647 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 648 * for stream sockets, although the total for sender and receiver is 649 * actually only PIPSIZ. 650 * Datagram sockets really use the sendspace as the maximum datagram size, 651 * and don't really want to reserve the sendspace. Their recvspace should 652 * be large enough for at least one max-size datagram plus address. 653 */ 654 #ifndef PIPSIZ 655 #define PIPSIZ 8192 656 #endif 657 static u_long unpst_sendspace = PIPSIZ; 658 static u_long unpst_recvspace = PIPSIZ; 659 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 660 static u_long unpdg_recvspace = 4*1024; 661 662 static int unp_rights; /* file descriptors in flight */ 663 664 SYSCTL_DECL(_net_local_stream); 665 SYSCTL_ULONG(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 666 &unpst_sendspace, 0, ""); 667 SYSCTL_ULONG(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 668 &unpst_recvspace, 0, ""); 669 SYSCTL_DECL(_net_local_dgram); 670 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 671 &unpdg_sendspace, 0, ""); 672 SYSCTL_ULONG(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 673 &unpdg_recvspace, 0, ""); 674 SYSCTL_DECL(_net_local); 675 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, ""); 676 677 static int 678 unp_attach(struct socket *so) 679 { 680 struct unpcb *unp; 681 int error; 682 683 KASSERT(so->so_pcb == NULL, ("unp_attach: so_pcb != NULL")); 684 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 685 switch (so->so_type) { 686 687 case SOCK_STREAM: 688 error = soreserve(so, unpst_sendspace, unpst_recvspace); 689 break; 690 691 case SOCK_DGRAM: 692 error = soreserve(so, unpdg_sendspace, unpdg_recvspace); 693 break; 694 695 default: 696 panic("unp_attach"); 697 } 698 if (error) 699 return (error); 700 } 701 unp = uma_zalloc(unp_zone, M_WAITOK | M_ZERO); 702 if (unp == NULL) 703 return (ENOBUFS); 704 LIST_INIT(&unp->unp_refs); 705 unp->unp_socket = so; 706 so->so_pcb = unp; 707 708 UNP_LOCK(); 709 unp->unp_gencnt = ++unp_gencnt; 710 unp_count++; 711 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead 712 : &unp_shead, unp, unp_link); 713 UNP_UNLOCK(); 714 715 return (0); 716 } 717 718 static void 719 unp_detach(struct unpcb *unp) 720 { 721 struct vnode *vp; 722 int local_unp_rights; 723 724 UNP_LOCK_ASSERT(); 725 726 LIST_REMOVE(unp, unp_link); 727 unp->unp_gencnt = ++unp_gencnt; 728 --unp_count; 729 if ((vp = unp->unp_vnode) != NULL) { 730 /* 731 * XXXRW: should v_socket be frobbed only while holding 732 * Giant? 733 */ 734 unp->unp_vnode->v_socket = NULL; 735 unp->unp_vnode = NULL; 736 } 737 if (unp->unp_conn != NULL) 738 unp_disconnect(unp); 739 while (!LIST_EMPTY(&unp->unp_refs)) { 740 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 741 unp_drop(ref, ECONNRESET); 742 } 743 soisdisconnected(unp->unp_socket); 744 unp->unp_socket->so_pcb = NULL; 745 local_unp_rights = unp_rights; 746 UNP_UNLOCK(); 747 if (unp->unp_addr != NULL) 748 FREE(unp->unp_addr, M_SONAME); 749 uma_zfree(unp_zone, unp); 750 if (vp) { 751 int vfslocked; 752 753 vfslocked = VFS_LOCK_GIANT(vp->v_mount); 754 vrele(vp); 755 VFS_UNLOCK_GIANT(vfslocked); 756 } 757 if (local_unp_rights) 758 taskqueue_enqueue(taskqueue_thread, &unp_gc_task); 759 } 760 761 static int 762 unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td) 763 { 764 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 765 struct vnode *vp; 766 struct mount *mp; 767 struct vattr vattr; 768 int error, namelen; 769 struct nameidata nd; 770 char *buf; 771 772 UNP_LOCK_ASSERT(); 773 774 /* 775 * XXXRW: This test-and-set of unp_vnode is non-atomic; the 776 * unlocked read here is fine, but the value of unp_vnode needs 777 * to be tested again after we do all the lookups to see if the 778 * pcb is still unbound? 779 */ 780 if (unp->unp_vnode != NULL) 781 return (EINVAL); 782 783 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 784 if (namelen <= 0) 785 return (EINVAL); 786 787 UNP_UNLOCK(); 788 789 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 790 strlcpy(buf, soun->sun_path, namelen + 1); 791 792 mtx_lock(&Giant); 793 restart: 794 mtx_assert(&Giant, MA_OWNED); 795 NDINIT(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME, UIO_SYSSPACE, 796 buf, td); 797 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 798 error = namei(&nd); 799 if (error) 800 goto done; 801 vp = nd.ni_vp; 802 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 803 NDFREE(&nd, NDF_ONLY_PNBUF); 804 if (nd.ni_dvp == vp) 805 vrele(nd.ni_dvp); 806 else 807 vput(nd.ni_dvp); 808 if (vp != NULL) { 809 vrele(vp); 810 error = EADDRINUSE; 811 goto done; 812 } 813 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 814 if (error) 815 goto done; 816 goto restart; 817 } 818 VATTR_NULL(&vattr); 819 vattr.va_type = VSOCK; 820 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 821 #ifdef MAC 822 error = mac_check_vnode_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 823 &vattr); 824 #endif 825 if (error == 0) { 826 VOP_LEASE(nd.ni_dvp, td, td->td_ucred, LEASE_WRITE); 827 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 828 } 829 NDFREE(&nd, NDF_ONLY_PNBUF); 830 vput(nd.ni_dvp); 831 if (error) { 832 vn_finished_write(mp); 833 goto done; 834 } 835 vp = nd.ni_vp; 836 ASSERT_VOP_LOCKED(vp, "unp_bind"); 837 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 838 UNP_LOCK(); 839 vp->v_socket = unp->unp_socket; 840 unp->unp_vnode = vp; 841 unp->unp_addr = soun; 842 UNP_UNLOCK(); 843 VOP_UNLOCK(vp, 0, td); 844 vn_finished_write(mp); 845 done: 846 mtx_unlock(&Giant); 847 free(buf, M_TEMP); 848 UNP_LOCK(); 849 return (error); 850 } 851 852 static int 853 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 854 { 855 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 856 struct vnode *vp; 857 struct socket *so2, *so3; 858 struct unpcb *unp, *unp2, *unp3; 859 int error, len; 860 struct nameidata nd; 861 char buf[SOCK_MAXADDRLEN]; 862 struct sockaddr *sa; 863 864 UNP_LOCK_ASSERT(); 865 866 unp = sotounpcb(so); 867 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 868 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 869 if (len <= 0) 870 return (EINVAL); 871 strlcpy(buf, soun->sun_path, len + 1); 872 UNP_UNLOCK(); 873 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 874 mtx_lock(&Giant); 875 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, td); 876 error = namei(&nd); 877 if (error) 878 vp = NULL; 879 else 880 vp = nd.ni_vp; 881 ASSERT_VOP_LOCKED(vp, "unp_connect"); 882 NDFREE(&nd, NDF_ONLY_PNBUF); 883 if (error) 884 goto bad; 885 886 if (vp->v_type != VSOCK) { 887 error = ENOTSOCK; 888 goto bad; 889 } 890 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 891 if (error) 892 goto bad; 893 mtx_unlock(&Giant); 894 UNP_LOCK(); 895 unp = sotounpcb(so); 896 KASSERT(unp != NULL, ("unp_connect: unp == NULL")); 897 so2 = vp->v_socket; 898 if (so2 == NULL) { 899 error = ECONNREFUSED; 900 goto bad2; 901 } 902 if (so->so_type != so2->so_type) { 903 error = EPROTOTYPE; 904 goto bad2; 905 } 906 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 907 if (so2->so_options & SO_ACCEPTCONN) { 908 /* 909 * NB: drop locks here so unp_attach is entered 910 * w/o locks; this avoids a recursive lock 911 * of the head and holding sleep locks across 912 * a (potentially) blocking malloc. 913 */ 914 UNP_UNLOCK(); 915 so3 = sonewconn(so2, 0); 916 UNP_LOCK(); 917 } else 918 so3 = NULL; 919 if (so3 == NULL) { 920 error = ECONNREFUSED; 921 goto bad2; 922 } 923 unp = sotounpcb(so); 924 unp2 = sotounpcb(so2); 925 unp3 = sotounpcb(so3); 926 if (unp2->unp_addr != NULL) { 927 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 928 unp3->unp_addr = (struct sockaddr_un *) sa; 929 sa = NULL; 930 } 931 /* 932 * unp_peercred management: 933 * 934 * The connecter's (client's) credentials are copied 935 * from its process structure at the time of connect() 936 * (which is now). 937 */ 938 cru2x(td->td_ucred, &unp3->unp_peercred); 939 unp3->unp_flags |= UNP_HAVEPC; 940 /* 941 * The receiver's (server's) credentials are copied 942 * from the unp_peercred member of socket on which the 943 * former called listen(); unp_listen() cached that 944 * process's credentials at that time so we can use 945 * them now. 946 */ 947 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 948 ("unp_connect: listener without cached peercred")); 949 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 950 sizeof(unp->unp_peercred)); 951 unp->unp_flags |= UNP_HAVEPC; 952 #ifdef MAC 953 SOCK_LOCK(so); 954 mac_set_socket_peer_from_socket(so, so3); 955 mac_set_socket_peer_from_socket(so3, so); 956 SOCK_UNLOCK(so); 957 #endif 958 959 so2 = so3; 960 } 961 error = unp_connect2(so, so2, PRU_CONNECT); 962 bad2: 963 UNP_UNLOCK(); 964 mtx_lock(&Giant); 965 bad: 966 mtx_assert(&Giant, MA_OWNED); 967 if (vp != NULL) 968 vput(vp); 969 mtx_unlock(&Giant); 970 free(sa, M_SONAME); 971 UNP_LOCK(); 972 return (error); 973 } 974 975 static int 976 unp_connect2(struct socket *so, struct socket *so2, int req) 977 { 978 struct unpcb *unp = sotounpcb(so); 979 struct unpcb *unp2; 980 981 UNP_LOCK_ASSERT(); 982 983 if (so2->so_type != so->so_type) 984 return (EPROTOTYPE); 985 unp2 = sotounpcb(so2); 986 KASSERT(unp2 != NULL, ("unp_connect2: unp2 == NULL")); 987 unp->unp_conn = unp2; 988 switch (so->so_type) { 989 990 case SOCK_DGRAM: 991 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 992 soisconnected(so); 993 break; 994 995 case SOCK_STREAM: 996 unp2->unp_conn = unp; 997 if (req == PRU_CONNECT && 998 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 999 soisconnecting(so); 1000 else 1001 soisconnected(so); 1002 soisconnected(so2); 1003 break; 1004 1005 default: 1006 panic("unp_connect2"); 1007 } 1008 return (0); 1009 } 1010 1011 static void 1012 unp_disconnect(struct unpcb *unp) 1013 { 1014 struct unpcb *unp2 = unp->unp_conn; 1015 struct socket *so; 1016 1017 UNP_LOCK_ASSERT(); 1018 1019 if (unp2 == NULL) 1020 return; 1021 unp->unp_conn = NULL; 1022 switch (unp->unp_socket->so_type) { 1023 case SOCK_DGRAM: 1024 LIST_REMOVE(unp, unp_reflink); 1025 so = unp->unp_socket; 1026 SOCK_LOCK(so); 1027 so->so_state &= ~SS_ISCONNECTED; 1028 SOCK_UNLOCK(so); 1029 break; 1030 1031 case SOCK_STREAM: 1032 soisdisconnected(unp->unp_socket); 1033 unp2->unp_conn = NULL; 1034 soisdisconnected(unp2->unp_socket); 1035 break; 1036 } 1037 } 1038 1039 #ifdef notdef 1040 void 1041 unp_abort(struct unpcb *unp) 1042 { 1043 1044 unp_detach(unp); 1045 UNP_UNLOCK_ASSERT(); 1046 } 1047 #endif 1048 1049 /* 1050 * unp_pcblist() assumes that UNIX domain socket memory is never reclaimed 1051 * by the zone (UMA_ZONE_NOFREE), and as such potentially stale pointers 1052 * are safe to reference. It first scans the list of struct unpcb's to 1053 * generate a pointer list, then it rescans its list one entry at a time to 1054 * externalize and copyout. It checks the generation number to see if a 1055 * struct unpcb has been reused, and will skip it if so. 1056 */ 1057 static int 1058 unp_pcblist(SYSCTL_HANDLER_ARGS) 1059 { 1060 int error, i, n; 1061 struct unpcb *unp, **unp_list; 1062 unp_gen_t gencnt; 1063 struct xunpgen *xug; 1064 struct unp_head *head; 1065 struct xunpcb *xu; 1066 1067 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 1068 1069 /* 1070 * The process of preparing the PCB list is too time-consuming and 1071 * resource-intensive to repeat twice on every request. 1072 */ 1073 if (req->oldptr == NULL) { 1074 n = unp_count; 1075 req->oldidx = 2 * (sizeof *xug) 1076 + (n + n/8) * sizeof(struct xunpcb); 1077 return (0); 1078 } 1079 1080 if (req->newptr != NULL) 1081 return (EPERM); 1082 1083 /* 1084 * OK, now we're committed to doing something. 1085 */ 1086 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1087 UNP_LOCK(); 1088 gencnt = unp_gencnt; 1089 n = unp_count; 1090 UNP_UNLOCK(); 1091 1092 xug->xug_len = sizeof *xug; 1093 xug->xug_count = n; 1094 xug->xug_gen = gencnt; 1095 xug->xug_sogen = so_gencnt; 1096 error = SYSCTL_OUT(req, xug, sizeof *xug); 1097 if (error) { 1098 free(xug, M_TEMP); 1099 return (error); 1100 } 1101 1102 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1103 1104 UNP_LOCK(); 1105 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1106 unp = LIST_NEXT(unp, unp_link)) { 1107 if (unp->unp_gencnt <= gencnt) { 1108 if (cr_cansee(req->td->td_ucred, 1109 unp->unp_socket->so_cred)) 1110 continue; 1111 unp_list[i++] = unp; 1112 } 1113 } 1114 UNP_UNLOCK(); 1115 n = i; /* in case we lost some during malloc */ 1116 1117 error = 0; 1118 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1119 for (i = 0; i < n; i++) { 1120 unp = unp_list[i]; 1121 if (unp->unp_gencnt <= gencnt) { 1122 xu->xu_len = sizeof *xu; 1123 xu->xu_unpp = unp; 1124 /* 1125 * XXX - need more locking here to protect against 1126 * connect/disconnect races for SMP. 1127 */ 1128 if (unp->unp_addr != NULL) 1129 bcopy(unp->unp_addr, &xu->xu_addr, 1130 unp->unp_addr->sun_len); 1131 if (unp->unp_conn != NULL && 1132 unp->unp_conn->unp_addr != NULL) 1133 bcopy(unp->unp_conn->unp_addr, 1134 &xu->xu_caddr, 1135 unp->unp_conn->unp_addr->sun_len); 1136 bcopy(unp, &xu->xu_unp, sizeof *unp); 1137 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1138 error = SYSCTL_OUT(req, xu, sizeof *xu); 1139 } 1140 } 1141 free(xu, M_TEMP); 1142 if (!error) { 1143 /* 1144 * Give the user an updated idea of our state. 1145 * If the generation differs from what we told 1146 * her before, she knows that something happened 1147 * while we were processing this request, and it 1148 * might be necessary to retry. 1149 */ 1150 xug->xug_gen = unp_gencnt; 1151 xug->xug_sogen = so_gencnt; 1152 xug->xug_count = unp_count; 1153 error = SYSCTL_OUT(req, xug, sizeof *xug); 1154 } 1155 free(unp_list, M_TEMP); 1156 free(xug, M_TEMP); 1157 return (error); 1158 } 1159 1160 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 1161 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1162 "List of active local datagram sockets"); 1163 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 1164 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1165 "List of active local stream sockets"); 1166 1167 static void 1168 unp_shutdown(struct unpcb *unp) 1169 { 1170 struct socket *so; 1171 1172 UNP_LOCK_ASSERT(); 1173 1174 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn && 1175 (so = unp->unp_conn->unp_socket)) 1176 socantrcvmore(so); 1177 } 1178 1179 static void 1180 unp_drop(struct unpcb *unp, int errno) 1181 { 1182 struct socket *so = unp->unp_socket; 1183 1184 UNP_LOCK_ASSERT(); 1185 1186 so->so_error = errno; 1187 unp_disconnect(unp); 1188 } 1189 1190 #ifdef notdef 1191 void 1192 unp_drain(void) 1193 { 1194 1195 } 1196 #endif 1197 1198 static void 1199 unp_freerights(struct file **rp, int fdcount) 1200 { 1201 int i; 1202 struct file *fp; 1203 1204 for (i = 0; i < fdcount; i++) { 1205 fp = *rp; 1206 /* 1207 * zero the pointer before calling 1208 * unp_discard since it may end up 1209 * in unp_gc().. 1210 * 1211 * XXXRW: This is less true than it used to be. 1212 */ 1213 *rp++ = 0; 1214 unp_discard(fp); 1215 } 1216 } 1217 1218 int 1219 unp_externalize(struct mbuf *control, struct mbuf **controlp) 1220 { 1221 struct thread *td = curthread; /* XXX */ 1222 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1223 int i; 1224 int *fdp; 1225 struct file **rp; 1226 struct file *fp; 1227 void *data; 1228 socklen_t clen = control->m_len, datalen; 1229 int error, newfds; 1230 int f; 1231 u_int newlen; 1232 1233 UNP_UNLOCK_ASSERT(); 1234 1235 error = 0; 1236 if (controlp != NULL) /* controlp == NULL => free control messages */ 1237 *controlp = NULL; 1238 1239 while (cm != NULL) { 1240 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1241 error = EINVAL; 1242 break; 1243 } 1244 1245 data = CMSG_DATA(cm); 1246 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1247 1248 if (cm->cmsg_level == SOL_SOCKET 1249 && cm->cmsg_type == SCM_RIGHTS) { 1250 newfds = datalen / sizeof(struct file *); 1251 rp = data; 1252 1253 /* If we're not outputting the descriptors free them. */ 1254 if (error || controlp == NULL) { 1255 unp_freerights(rp, newfds); 1256 goto next; 1257 } 1258 FILEDESC_LOCK(td->td_proc->p_fd); 1259 /* if the new FD's will not fit free them. */ 1260 if (!fdavail(td, newfds)) { 1261 FILEDESC_UNLOCK(td->td_proc->p_fd); 1262 error = EMSGSIZE; 1263 unp_freerights(rp, newfds); 1264 goto next; 1265 } 1266 /* 1267 * now change each pointer to an fd in the global 1268 * table to an integer that is the index to the 1269 * local fd table entry that we set up to point 1270 * to the global one we are transferring. 1271 */ 1272 newlen = newfds * sizeof(int); 1273 *controlp = sbcreatecontrol(NULL, newlen, 1274 SCM_RIGHTS, SOL_SOCKET); 1275 if (*controlp == NULL) { 1276 FILEDESC_UNLOCK(td->td_proc->p_fd); 1277 error = E2BIG; 1278 unp_freerights(rp, newfds); 1279 goto next; 1280 } 1281 1282 fdp = (int *) 1283 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1284 for (i = 0; i < newfds; i++) { 1285 if (fdalloc(td, 0, &f)) 1286 panic("unp_externalize fdalloc failed"); 1287 fp = *rp++; 1288 td->td_proc->p_fd->fd_ofiles[f] = fp; 1289 FILE_LOCK(fp); 1290 fp->f_msgcount--; 1291 FILE_UNLOCK(fp); 1292 unp_rights--; 1293 *fdp++ = f; 1294 } 1295 FILEDESC_UNLOCK(td->td_proc->p_fd); 1296 } else { /* We can just copy anything else across */ 1297 if (error || controlp == NULL) 1298 goto next; 1299 *controlp = sbcreatecontrol(NULL, datalen, 1300 cm->cmsg_type, cm->cmsg_level); 1301 if (*controlp == NULL) { 1302 error = ENOBUFS; 1303 goto next; 1304 } 1305 bcopy(data, 1306 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1307 datalen); 1308 } 1309 1310 controlp = &(*controlp)->m_next; 1311 1312 next: 1313 if (CMSG_SPACE(datalen) < clen) { 1314 clen -= CMSG_SPACE(datalen); 1315 cm = (struct cmsghdr *) 1316 ((caddr_t)cm + CMSG_SPACE(datalen)); 1317 } else { 1318 clen = 0; 1319 cm = NULL; 1320 } 1321 } 1322 1323 m_freem(control); 1324 1325 return (error); 1326 } 1327 1328 void 1329 unp_init(void) 1330 { 1331 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1332 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 1333 if (unp_zone == NULL) 1334 panic("unp_init"); 1335 uma_zone_set_max(unp_zone, nmbclusters); 1336 LIST_INIT(&unp_dhead); 1337 LIST_INIT(&unp_shead); 1338 TASK_INIT(&unp_gc_task, 0, unp_gc, NULL); 1339 UNP_LOCK_INIT(); 1340 } 1341 1342 static int 1343 unp_internalize(struct mbuf **controlp, struct thread *td) 1344 { 1345 struct mbuf *control = *controlp; 1346 struct proc *p = td->td_proc; 1347 struct filedesc *fdescp = p->p_fd; 1348 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1349 struct cmsgcred *cmcred; 1350 struct file **rp; 1351 struct file *fp; 1352 struct timeval *tv; 1353 int i, fd, *fdp; 1354 void *data; 1355 socklen_t clen = control->m_len, datalen; 1356 int error, oldfds; 1357 u_int newlen; 1358 1359 UNP_UNLOCK_ASSERT(); 1360 1361 error = 0; 1362 *controlp = NULL; 1363 1364 while (cm != NULL) { 1365 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1366 || cm->cmsg_len > clen) { 1367 error = EINVAL; 1368 goto out; 1369 } 1370 1371 data = CMSG_DATA(cm); 1372 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1373 1374 switch (cm->cmsg_type) { 1375 /* 1376 * Fill in credential information. 1377 */ 1378 case SCM_CREDS: 1379 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1380 SCM_CREDS, SOL_SOCKET); 1381 if (*controlp == NULL) { 1382 error = ENOBUFS; 1383 goto out; 1384 } 1385 1386 cmcred = (struct cmsgcred *) 1387 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1388 cmcred->cmcred_pid = p->p_pid; 1389 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1390 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1391 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1392 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1393 CMGROUP_MAX); 1394 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1395 cmcred->cmcred_groups[i] = 1396 td->td_ucred->cr_groups[i]; 1397 break; 1398 1399 case SCM_RIGHTS: 1400 oldfds = datalen / sizeof (int); 1401 /* 1402 * check that all the FDs passed in refer to legal files 1403 * If not, reject the entire operation. 1404 */ 1405 fdp = data; 1406 FILEDESC_LOCK(fdescp); 1407 for (i = 0; i < oldfds; i++) { 1408 fd = *fdp++; 1409 if ((unsigned)fd >= fdescp->fd_nfiles || 1410 fdescp->fd_ofiles[fd] == NULL) { 1411 FILEDESC_UNLOCK(fdescp); 1412 error = EBADF; 1413 goto out; 1414 } 1415 fp = fdescp->fd_ofiles[fd]; 1416 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1417 FILEDESC_UNLOCK(fdescp); 1418 error = EOPNOTSUPP; 1419 goto out; 1420 } 1421 1422 } 1423 /* 1424 * Now replace the integer FDs with pointers to 1425 * the associated global file table entry.. 1426 */ 1427 newlen = oldfds * sizeof(struct file *); 1428 *controlp = sbcreatecontrol(NULL, newlen, 1429 SCM_RIGHTS, SOL_SOCKET); 1430 if (*controlp == NULL) { 1431 FILEDESC_UNLOCK(fdescp); 1432 error = E2BIG; 1433 goto out; 1434 } 1435 1436 fdp = data; 1437 rp = (struct file **) 1438 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1439 for (i = 0; i < oldfds; i++) { 1440 fp = fdescp->fd_ofiles[*fdp++]; 1441 *rp++ = fp; 1442 FILE_LOCK(fp); 1443 fp->f_count++; 1444 fp->f_msgcount++; 1445 FILE_UNLOCK(fp); 1446 unp_rights++; 1447 } 1448 FILEDESC_UNLOCK(fdescp); 1449 break; 1450 1451 case SCM_TIMESTAMP: 1452 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1453 SCM_TIMESTAMP, SOL_SOCKET); 1454 if (*controlp == NULL) { 1455 error = ENOBUFS; 1456 goto out; 1457 } 1458 tv = (struct timeval *) 1459 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1460 microtime(tv); 1461 break; 1462 1463 default: 1464 error = EINVAL; 1465 goto out; 1466 } 1467 1468 controlp = &(*controlp)->m_next; 1469 1470 if (CMSG_SPACE(datalen) < clen) { 1471 clen -= CMSG_SPACE(datalen); 1472 cm = (struct cmsghdr *) 1473 ((caddr_t)cm + CMSG_SPACE(datalen)); 1474 } else { 1475 clen = 0; 1476 cm = NULL; 1477 } 1478 } 1479 1480 out: 1481 m_freem(control); 1482 1483 return (error); 1484 } 1485 1486 struct mbuf * 1487 unp_addsockcred(struct thread *td, struct mbuf *control) 1488 { 1489 struct mbuf *m, *n; 1490 struct sockcred *sc; 1491 int ngroups; 1492 int i; 1493 1494 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 1495 1496 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 1497 if (m == NULL) 1498 return (control); 1499 m->m_next = NULL; 1500 1501 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 1502 sc->sc_uid = td->td_ucred->cr_ruid; 1503 sc->sc_euid = td->td_ucred->cr_uid; 1504 sc->sc_gid = td->td_ucred->cr_rgid; 1505 sc->sc_egid = td->td_ucred->cr_gid; 1506 sc->sc_ngroups = ngroups; 1507 for (i = 0; i < sc->sc_ngroups; i++) 1508 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 1509 1510 /* 1511 * If a control message already exists, append us to the end. 1512 */ 1513 if (control != NULL) { 1514 for (n = control; n->m_next != NULL; n = n->m_next) 1515 ; 1516 n->m_next = m; 1517 } else 1518 control = m; 1519 1520 return (control); 1521 } 1522 1523 /* 1524 * unp_defer indicates whether additional work has been defered for a future 1525 * pass through unp_gc(). It is thread local and does not require explicit 1526 * synchronization. 1527 */ 1528 static int unp_defer; 1529 1530 static int unp_taskcount; 1531 SYSCTL_INT(_net_local, OID_AUTO, taskcount, CTLFLAG_RD, &unp_taskcount, 0, ""); 1532 1533 static int unp_recycled; 1534 SYSCTL_INT(_net_local, OID_AUTO, recycled, CTLFLAG_RD, &unp_recycled, 0, ""); 1535 1536 static void 1537 unp_gc(__unused void *arg, int pending) 1538 { 1539 struct file *fp, *nextfp; 1540 struct socket *so; 1541 struct file **extra_ref, **fpp; 1542 int nunref, i; 1543 int nfiles_snap; 1544 int nfiles_slack = 20; 1545 1546 unp_taskcount++; 1547 unp_defer = 0; 1548 /* 1549 * before going through all this, set all FDs to 1550 * be NOT defered and NOT externally accessible 1551 */ 1552 sx_slock(&filelist_lock); 1553 LIST_FOREACH(fp, &filehead, f_list) 1554 fp->f_gcflag &= ~(FMARK|FDEFER); 1555 do { 1556 KASSERT(unp_defer >= 0, ("unp_gc: unp_defer %d", unp_defer)); 1557 LIST_FOREACH(fp, &filehead, f_list) { 1558 FILE_LOCK(fp); 1559 /* 1560 * If the file is not open, skip it -- could be a 1561 * file in the process of being opened, or in the 1562 * process of being closed. If the file is 1563 * "closing", it may have been marked for deferred 1564 * consideration. Clear the flag now if so. 1565 */ 1566 if (fp->f_count == 0) { 1567 if (fp->f_gcflag & FDEFER) 1568 unp_defer--; 1569 fp->f_gcflag &= ~(FMARK|FDEFER); 1570 FILE_UNLOCK(fp); 1571 continue; 1572 } 1573 /* 1574 * If we already marked it as 'defer' in a 1575 * previous pass, then try process it this time 1576 * and un-mark it 1577 */ 1578 if (fp->f_gcflag & FDEFER) { 1579 fp->f_gcflag &= ~FDEFER; 1580 unp_defer--; 1581 } else { 1582 /* 1583 * if it's not defered, then check if it's 1584 * already marked.. if so skip it 1585 */ 1586 if (fp->f_gcflag & FMARK) { 1587 FILE_UNLOCK(fp); 1588 continue; 1589 } 1590 /* 1591 * If all references are from messages 1592 * in transit, then skip it. it's not 1593 * externally accessible. 1594 */ 1595 if (fp->f_count == fp->f_msgcount) { 1596 FILE_UNLOCK(fp); 1597 continue; 1598 } 1599 /* 1600 * If it got this far then it must be 1601 * externally accessible. 1602 */ 1603 fp->f_gcflag |= FMARK; 1604 } 1605 /* 1606 * either it was defered, or it is externally 1607 * accessible and not already marked so. 1608 * Now check if it is possibly one of OUR sockets. 1609 */ 1610 if (fp->f_type != DTYPE_SOCKET || 1611 (so = fp->f_data) == NULL) { 1612 FILE_UNLOCK(fp); 1613 continue; 1614 } 1615 FILE_UNLOCK(fp); 1616 if (so->so_proto->pr_domain != &localdomain || 1617 (so->so_proto->pr_flags&PR_RIGHTS) == 0) 1618 continue; 1619 /* 1620 * So, Ok, it's one of our sockets and it IS externally 1621 * accessible (or was defered). Now we look 1622 * to see if we hold any file descriptors in its 1623 * message buffers. Follow those links and mark them 1624 * as accessible too. 1625 */ 1626 SOCKBUF_LOCK(&so->so_rcv); 1627 unp_scan(so->so_rcv.sb_mb, unp_mark); 1628 SOCKBUF_UNLOCK(&so->so_rcv); 1629 } 1630 } while (unp_defer); 1631 sx_sunlock(&filelist_lock); 1632 /* 1633 * XXXRW: The following comments need updating for a post-SMPng and 1634 * deferred unp_gc() world, but are still generally accurate. 1635 * 1636 * We grab an extra reference to each of the file table entries 1637 * that are not otherwise accessible and then free the rights 1638 * that are stored in messages on them. 1639 * 1640 * The bug in the orginal code is a little tricky, so I'll describe 1641 * what's wrong with it here. 1642 * 1643 * It is incorrect to simply unp_discard each entry for f_msgcount 1644 * times -- consider the case of sockets A and B that contain 1645 * references to each other. On a last close of some other socket, 1646 * we trigger a gc since the number of outstanding rights (unp_rights) 1647 * is non-zero. If during the sweep phase the gc code unp_discards, 1648 * we end up doing a (full) closef on the descriptor. A closef on A 1649 * results in the following chain. Closef calls soo_close, which 1650 * calls soclose. Soclose calls first (through the switch 1651 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply 1652 * returns because the previous instance had set unp_gcing, and 1653 * we return all the way back to soclose, which marks the socket 1654 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush 1655 * to free up the rights that are queued in messages on the socket A, 1656 * i.e., the reference on B. The sorflush calls via the dom_dispose 1657 * switch unp_dispose, which unp_scans with unp_discard. This second 1658 * instance of unp_discard just calls closef on B. 1659 * 1660 * Well, a similar chain occurs on B, resulting in a sorflush on B, 1661 * which results in another closef on A. Unfortunately, A is already 1662 * being closed, and the descriptor has already been marked with 1663 * SS_NOFDREF, and soclose panics at this point. 1664 * 1665 * Here, we first take an extra reference to each inaccessible 1666 * descriptor. Then, we call sorflush ourself, since we know 1667 * it is a Unix domain socket anyhow. After we destroy all the 1668 * rights carried in messages, we do a last closef to get rid 1669 * of our extra reference. This is the last close, and the 1670 * unp_detach etc will shut down the socket. 1671 * 1672 * 91/09/19, bsy@cs.cmu.edu 1673 */ 1674 again: 1675 nfiles_snap = openfiles + nfiles_slack; /* some slack */ 1676 extra_ref = malloc(nfiles_snap * sizeof(struct file *), M_TEMP, 1677 M_WAITOK); 1678 sx_slock(&filelist_lock); 1679 if (nfiles_snap < openfiles) { 1680 sx_sunlock(&filelist_lock); 1681 free(extra_ref, M_TEMP); 1682 nfiles_slack += 20; 1683 goto again; 1684 } 1685 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; 1686 fp != NULL; fp = nextfp) { 1687 nextfp = LIST_NEXT(fp, f_list); 1688 FILE_LOCK(fp); 1689 /* 1690 * If it's not open, skip it 1691 */ 1692 if (fp->f_count == 0) { 1693 FILE_UNLOCK(fp); 1694 continue; 1695 } 1696 /* 1697 * If all refs are from msgs, and it's not marked accessible 1698 * then it must be referenced from some unreachable cycle 1699 * of (shut-down) FDs, so include it in our 1700 * list of FDs to remove 1701 */ 1702 if (fp->f_count == fp->f_msgcount && !(fp->f_gcflag & FMARK)) { 1703 *fpp++ = fp; 1704 nunref++; 1705 fp->f_count++; 1706 } 1707 FILE_UNLOCK(fp); 1708 } 1709 sx_sunlock(&filelist_lock); 1710 /* 1711 * for each FD on our hit list, do the following two things 1712 */ 1713 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) { 1714 struct file *tfp = *fpp; 1715 FILE_LOCK(tfp); 1716 if (tfp->f_type == DTYPE_SOCKET && 1717 tfp->f_data != NULL) { 1718 FILE_UNLOCK(tfp); 1719 sorflush(tfp->f_data); 1720 } else { 1721 FILE_UNLOCK(tfp); 1722 } 1723 } 1724 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) { 1725 closef(*fpp, (struct thread *) NULL); 1726 unp_recycled++; 1727 } 1728 free(extra_ref, M_TEMP); 1729 } 1730 1731 void 1732 unp_dispose(struct mbuf *m) 1733 { 1734 1735 if (m) 1736 unp_scan(m, unp_discard); 1737 } 1738 1739 static int 1740 unp_listen(struct socket *so, struct unpcb *unp, int backlog, 1741 struct thread *td) 1742 { 1743 int error; 1744 1745 UNP_LOCK_ASSERT(); 1746 1747 SOCK_LOCK(so); 1748 error = solisten_proto_check(so); 1749 if (error == 0) { 1750 cru2x(td->td_ucred, &unp->unp_peercred); 1751 unp->unp_flags |= UNP_HAVEPCCACHED; 1752 solisten_proto(so, backlog); 1753 } 1754 SOCK_UNLOCK(so); 1755 return (error); 1756 } 1757 1758 static void 1759 unp_scan(struct mbuf *m0, void (*op)(struct file *)) 1760 { 1761 struct mbuf *m; 1762 struct file **rp; 1763 struct cmsghdr *cm; 1764 void *data; 1765 int i; 1766 socklen_t clen, datalen; 1767 int qfds; 1768 1769 while (m0 != NULL) { 1770 for (m = m0; m; m = m->m_next) { 1771 if (m->m_type != MT_CONTROL) 1772 continue; 1773 1774 cm = mtod(m, struct cmsghdr *); 1775 clen = m->m_len; 1776 1777 while (cm != NULL) { 1778 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 1779 break; 1780 1781 data = CMSG_DATA(cm); 1782 datalen = (caddr_t)cm + cm->cmsg_len 1783 - (caddr_t)data; 1784 1785 if (cm->cmsg_level == SOL_SOCKET && 1786 cm->cmsg_type == SCM_RIGHTS) { 1787 qfds = datalen / sizeof (struct file *); 1788 rp = data; 1789 for (i = 0; i < qfds; i++) 1790 (*op)(*rp++); 1791 } 1792 1793 if (CMSG_SPACE(datalen) < clen) { 1794 clen -= CMSG_SPACE(datalen); 1795 cm = (struct cmsghdr *) 1796 ((caddr_t)cm + CMSG_SPACE(datalen)); 1797 } else { 1798 clen = 0; 1799 cm = NULL; 1800 } 1801 } 1802 } 1803 m0 = m0->m_act; 1804 } 1805 } 1806 1807 static void 1808 unp_mark(struct file *fp) 1809 { 1810 if (fp->f_gcflag & FMARK) 1811 return; 1812 unp_defer++; 1813 fp->f_gcflag |= (FMARK|FDEFER); 1814 } 1815 1816 static void 1817 unp_discard(struct file *fp) 1818 { 1819 UNP_LOCK(); 1820 FILE_LOCK(fp); 1821 fp->f_msgcount--; 1822 unp_rights--; 1823 FILE_UNLOCK(fp); 1824 UNP_UNLOCK(); 1825 (void) closef(fp, (struct thread *)NULL); 1826 } 1827