1 /*- 2 * Copyright 2004-2005 Robert N. M. Watson 3 * Copyright (c) 1982, 1986, 1989, 1991, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 4. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include "opt_mac.h" 37 38 #include <sys/param.h> 39 #include <sys/domain.h> 40 #include <sys/fcntl.h> 41 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 42 #include <sys/file.h> 43 #include <sys/filedesc.h> 44 #include <sys/jail.h> 45 #include <sys/kernel.h> 46 #include <sys/lock.h> 47 #include <sys/mac.h> 48 #include <sys/mbuf.h> 49 #include <sys/mutex.h> 50 #include <sys/namei.h> 51 #include <sys/proc.h> 52 #include <sys/protosw.h> 53 #include <sys/resourcevar.h> 54 #include <sys/socket.h> 55 #include <sys/socketvar.h> 56 #include <sys/signalvar.h> 57 #include <sys/stat.h> 58 #include <sys/sx.h> 59 #include <sys/sysctl.h> 60 #include <sys/systm.h> 61 #include <sys/un.h> 62 #include <sys/unpcb.h> 63 #include <sys/vnode.h> 64 65 #include <vm/uma.h> 66 67 static uma_zone_t unp_zone; 68 static unp_gen_t unp_gencnt; 69 static u_int unp_count; 70 71 static struct unp_head unp_shead, unp_dhead; 72 73 /* 74 * Unix communications domain. 75 * 76 * TODO: 77 * SEQPACKET, RDM 78 * rethink name space problems 79 * need a proper out-of-band 80 * lock pushdown 81 */ 82 static const struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 83 static ino_t unp_ino; /* prototype for fake inode numbers */ 84 85 /* 86 * Currently, UNIX domain sockets are protected by a single subsystem lock, 87 * which covers global data structures and variables, the contents of each 88 * per-socket unpcb structure, and the so_pcb field in sockets attached to 89 * the UNIX domain. This provides for a moderate degree of paralellism, as 90 * receive operations on UNIX domain sockets do not need to acquire the 91 * subsystem lock. Finer grained locking to permit send() without acquiring 92 * a global lock would be a logical next step. 93 * 94 * The UNIX domain socket lock preceds all socket layer locks, including the 95 * socket lock and socket buffer lock, permitting UNIX domain socket code to 96 * call into socket support routines without releasing its locks. 97 * 98 * Some caution is required in areas where the UNIX domain socket code enters 99 * VFS in order to create or find rendezvous points. This results in 100 * dropping of the UNIX domain socket subsystem lock, acquisition of the 101 * Giant lock, and potential sleeping. This increases the chances of races, 102 * and exposes weaknesses in the socket->protocol API by offering poor 103 * failure modes. 104 */ 105 static struct mtx unp_mtx; 106 #define UNP_LOCK_INIT() \ 107 mtx_init(&unp_mtx, "unp", NULL, MTX_DEF) 108 #define UNP_LOCK() mtx_lock(&unp_mtx) 109 #define UNP_UNLOCK() mtx_unlock(&unp_mtx) 110 #define UNP_LOCK_ASSERT() mtx_assert(&unp_mtx, MA_OWNED) 111 #define UNP_UNLOCK_ASSERT() mtx_assert(&unp_mtx, MA_NOTOWNED) 112 113 static int unp_attach(struct socket *); 114 static void unp_detach(struct unpcb *); 115 static int unp_bind(struct unpcb *,struct sockaddr *, struct thread *); 116 static int unp_connect(struct socket *,struct sockaddr *, struct thread *); 117 static int unp_connect2(struct socket *so, struct socket *so2); 118 static void unp_disconnect(struct unpcb *); 119 static void unp_shutdown(struct unpcb *); 120 static void unp_drop(struct unpcb *, int); 121 static void unp_gc(void); 122 static void unp_scan(struct mbuf *, void (*)(struct file *)); 123 static void unp_mark(struct file *); 124 static void unp_discard(struct file *); 125 static void unp_freerights(struct file **, int); 126 static int unp_internalize(struct mbuf **, struct thread *); 127 static int unp_listen(struct socket *, struct unpcb *, struct thread *); 128 129 static int 130 uipc_abort(struct socket *so) 131 { 132 struct unpcb *unp; 133 134 UNP_LOCK(); 135 unp = sotounpcb(so); 136 if (unp == NULL) { 137 UNP_UNLOCK(); 138 return (EINVAL); 139 } 140 unp_drop(unp, ECONNABORTED); 141 unp_detach(unp); 142 UNP_UNLOCK_ASSERT(); 143 ACCEPT_LOCK(); 144 SOCK_LOCK(so); 145 sotryfree(so); 146 return (0); 147 } 148 149 static int 150 uipc_accept(struct socket *so, struct sockaddr **nam) 151 { 152 struct unpcb *unp; 153 const struct sockaddr *sa; 154 155 /* 156 * Pass back name of connected socket, 157 * if it was bound and we are still connected 158 * (our peer may have closed already!). 159 */ 160 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 161 UNP_LOCK(); 162 unp = sotounpcb(so); 163 if (unp == NULL) { 164 UNP_UNLOCK(); 165 free(*nam, M_SONAME); 166 *nam = NULL; 167 return (EINVAL); 168 } 169 if (unp->unp_conn != NULL && unp->unp_conn->unp_addr != NULL) 170 sa = (struct sockaddr *) unp->unp_conn->unp_addr; 171 else 172 sa = &sun_noname; 173 bcopy(sa, *nam, sa->sa_len); 174 UNP_UNLOCK(); 175 return (0); 176 } 177 178 static int 179 uipc_attach(struct socket *so, int proto, struct thread *td) 180 { 181 struct unpcb *unp = sotounpcb(so); 182 183 if (unp != NULL) 184 return (EISCONN); 185 return (unp_attach(so)); 186 } 187 188 static int 189 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 190 { 191 struct unpcb *unp; 192 int error; 193 194 UNP_LOCK(); 195 unp = sotounpcb(so); 196 if (unp == NULL) { 197 UNP_UNLOCK(); 198 return (EINVAL); 199 } 200 error = unp_bind(unp, nam, td); 201 UNP_UNLOCK(); 202 return (error); 203 } 204 205 static int 206 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 207 { 208 struct unpcb *unp; 209 int error; 210 211 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 212 213 UNP_LOCK(); 214 unp = sotounpcb(so); 215 if (unp == NULL) { 216 UNP_UNLOCK(); 217 return (EINVAL); 218 } 219 error = unp_connect(so, nam, td); 220 UNP_UNLOCK(); 221 return (error); 222 } 223 224 int 225 uipc_connect2(struct socket *so1, struct socket *so2) 226 { 227 struct unpcb *unp; 228 int error; 229 230 UNP_LOCK(); 231 unp = sotounpcb(so1); 232 if (unp == NULL) { 233 UNP_UNLOCK(); 234 return (EINVAL); 235 } 236 error = unp_connect2(so1, so2); 237 UNP_UNLOCK(); 238 return (error); 239 } 240 241 /* control is EOPNOTSUPP */ 242 243 static int 244 uipc_detach(struct socket *so) 245 { 246 struct unpcb *unp; 247 248 UNP_LOCK(); 249 unp = sotounpcb(so); 250 if (unp == NULL) { 251 UNP_UNLOCK(); 252 return (EINVAL); 253 } 254 unp_detach(unp); 255 UNP_UNLOCK_ASSERT(); 256 return (0); 257 } 258 259 static int 260 uipc_disconnect(struct socket *so) 261 { 262 struct unpcb *unp; 263 264 UNP_LOCK(); 265 unp = sotounpcb(so); 266 if (unp == NULL) { 267 UNP_UNLOCK(); 268 return (EINVAL); 269 } 270 unp_disconnect(unp); 271 UNP_UNLOCK(); 272 return (0); 273 } 274 275 static int 276 uipc_listen(struct socket *so, struct thread *td) 277 { 278 struct unpcb *unp; 279 int error; 280 281 UNP_LOCK(); 282 unp = sotounpcb(so); 283 if (unp == NULL || unp->unp_vnode == NULL) { 284 UNP_UNLOCK(); 285 return (EINVAL); 286 } 287 error = unp_listen(so, unp, td); 288 UNP_UNLOCK(); 289 return (error); 290 } 291 292 static int 293 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 294 { 295 struct unpcb *unp; 296 const struct sockaddr *sa; 297 298 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 299 UNP_LOCK(); 300 unp = sotounpcb(so); 301 if (unp == NULL) { 302 UNP_UNLOCK(); 303 free(*nam, M_SONAME); 304 *nam = NULL; 305 return (EINVAL); 306 } 307 if (unp->unp_conn != NULL && unp->unp_conn->unp_addr!= NULL) 308 sa = (struct sockaddr *) unp->unp_conn->unp_addr; 309 else { 310 /* 311 * XXX: It seems that this test always fails even when 312 * connection is established. So, this else clause is 313 * added as workaround to return PF_LOCAL sockaddr. 314 */ 315 sa = &sun_noname; 316 } 317 bcopy(sa, *nam, sa->sa_len); 318 UNP_UNLOCK(); 319 return (0); 320 } 321 322 static int 323 uipc_rcvd(struct socket *so, int flags) 324 { 325 struct unpcb *unp; 326 struct socket *so2; 327 u_long newhiwat; 328 329 UNP_LOCK(); 330 unp = sotounpcb(so); 331 if (unp == NULL) { 332 UNP_UNLOCK(); 333 return (EINVAL); 334 } 335 switch (so->so_type) { 336 case SOCK_DGRAM: 337 panic("uipc_rcvd DGRAM?"); 338 /*NOTREACHED*/ 339 340 case SOCK_STREAM: 341 if (unp->unp_conn == NULL) 342 break; 343 so2 = unp->unp_conn->unp_socket; 344 SOCKBUF_LOCK(&so2->so_snd); 345 SOCKBUF_LOCK(&so->so_rcv); 346 /* 347 * Adjust backpressure on sender 348 * and wakeup any waiting to write. 349 */ 350 so2->so_snd.sb_mbmax += unp->unp_mbcnt - so->so_rcv.sb_mbcnt; 351 unp->unp_mbcnt = so->so_rcv.sb_mbcnt; 352 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - 353 so->so_rcv.sb_cc; 354 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, 355 newhiwat, RLIM_INFINITY); 356 unp->unp_cc = so->so_rcv.sb_cc; 357 SOCKBUF_UNLOCK(&so->so_rcv); 358 sowwakeup_locked(so2); 359 break; 360 361 default: 362 panic("uipc_rcvd unknown socktype"); 363 } 364 UNP_UNLOCK(); 365 return (0); 366 } 367 368 /* pru_rcvoob is EOPNOTSUPP */ 369 370 static int 371 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 372 struct mbuf *control, struct thread *td) 373 { 374 int error = 0; 375 struct unpcb *unp; 376 struct socket *so2; 377 u_long newhiwat; 378 379 unp = sotounpcb(so); 380 if (unp == NULL) { 381 error = EINVAL; 382 goto release; 383 } 384 if (flags & PRUS_OOB) { 385 error = EOPNOTSUPP; 386 goto release; 387 } 388 389 if (control != NULL && (error = unp_internalize(&control, td))) 390 goto release; 391 392 UNP_LOCK(); 393 unp = sotounpcb(so); 394 if (unp == NULL) { 395 UNP_UNLOCK(); 396 error = EINVAL; 397 goto dispose_release; 398 } 399 400 switch (so->so_type) { 401 case SOCK_DGRAM: 402 { 403 const struct sockaddr *from; 404 405 if (nam != NULL) { 406 if (unp->unp_conn != NULL) { 407 error = EISCONN; 408 break; 409 } 410 error = unp_connect(so, nam, td); 411 if (error) 412 break; 413 } else { 414 if (unp->unp_conn == NULL) { 415 error = ENOTCONN; 416 break; 417 } 418 } 419 so2 = unp->unp_conn->unp_socket; 420 if (unp->unp_addr != NULL) 421 from = (struct sockaddr *)unp->unp_addr; 422 else 423 from = &sun_noname; 424 SOCKBUF_LOCK(&so2->so_rcv); 425 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) { 426 sorwakeup_locked(so2); 427 m = NULL; 428 control = NULL; 429 } else { 430 SOCKBUF_UNLOCK(&so2->so_rcv); 431 error = ENOBUFS; 432 } 433 if (nam != NULL) 434 unp_disconnect(unp); 435 break; 436 } 437 438 case SOCK_STREAM: 439 /* Connect if not connected yet. */ 440 /* 441 * Note: A better implementation would complain 442 * if not equal to the peer's address. 443 */ 444 if ((so->so_state & SS_ISCONNECTED) == 0) { 445 if (nam != NULL) { 446 error = unp_connect(so, nam, td); 447 if (error) 448 break; /* XXX */ 449 } else { 450 error = ENOTCONN; 451 break; 452 } 453 } 454 455 SOCKBUF_LOCK(&so->so_snd); 456 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 457 SOCKBUF_UNLOCK(&so->so_snd); 458 error = EPIPE; 459 break; 460 } 461 if (unp->unp_conn == NULL) 462 panic("uipc_send connected but no connection?"); 463 so2 = unp->unp_conn->unp_socket; 464 SOCKBUF_LOCK(&so2->so_rcv); 465 /* 466 * Send to paired receive port, and then reduce 467 * send buffer hiwater marks to maintain backpressure. 468 * Wake up readers. 469 */ 470 if (control != NULL) { 471 if (sbappendcontrol_locked(&so2->so_rcv, m, control)) 472 control = NULL; 473 } else { 474 sbappend_locked(&so2->so_rcv, m); 475 } 476 so->so_snd.sb_mbmax -= 477 so2->so_rcv.sb_mbcnt - unp->unp_conn->unp_mbcnt; 478 unp->unp_conn->unp_mbcnt = so2->so_rcv.sb_mbcnt; 479 newhiwat = so->so_snd.sb_hiwat - 480 (so2->so_rcv.sb_cc - unp->unp_conn->unp_cc); 481 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, 482 newhiwat, RLIM_INFINITY); 483 SOCKBUF_UNLOCK(&so->so_snd); 484 unp->unp_conn->unp_cc = so2->so_rcv.sb_cc; 485 sorwakeup_locked(so2); 486 m = NULL; 487 break; 488 489 default: 490 panic("uipc_send unknown socktype"); 491 } 492 493 /* 494 * SEND_EOF is equivalent to a SEND followed by 495 * a SHUTDOWN. 496 */ 497 if (flags & PRUS_EOF) { 498 socantsendmore(so); 499 unp_shutdown(unp); 500 } 501 UNP_UNLOCK(); 502 503 dispose_release: 504 if (control != NULL && error != 0) 505 unp_dispose(control); 506 507 release: 508 if (control != NULL) 509 m_freem(control); 510 if (m != NULL) 511 m_freem(m); 512 return (error); 513 } 514 515 static int 516 uipc_sense(struct socket *so, struct stat *sb) 517 { 518 struct unpcb *unp; 519 struct socket *so2; 520 521 UNP_LOCK(); 522 unp = sotounpcb(so); 523 if (unp == NULL) { 524 UNP_UNLOCK(); 525 return (EINVAL); 526 } 527 sb->st_blksize = so->so_snd.sb_hiwat; 528 if (so->so_type == SOCK_STREAM && unp->unp_conn != NULL) { 529 so2 = unp->unp_conn->unp_socket; 530 sb->st_blksize += so2->so_rcv.sb_cc; 531 } 532 sb->st_dev = NODEV; 533 if (unp->unp_ino == 0) 534 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 535 sb->st_ino = unp->unp_ino; 536 UNP_UNLOCK(); 537 return (0); 538 } 539 540 static int 541 uipc_shutdown(struct socket *so) 542 { 543 struct unpcb *unp; 544 545 UNP_LOCK(); 546 unp = sotounpcb(so); 547 if (unp == NULL) { 548 UNP_UNLOCK(); 549 return (EINVAL); 550 } 551 socantsendmore(so); 552 unp_shutdown(unp); 553 UNP_UNLOCK(); 554 return (0); 555 } 556 557 static int 558 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 559 { 560 struct unpcb *unp; 561 const struct sockaddr *sa; 562 563 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 564 UNP_LOCK(); 565 unp = sotounpcb(so); 566 if (unp == NULL) { 567 UNP_UNLOCK(); 568 free(*nam, M_SONAME); 569 *nam = NULL; 570 return (EINVAL); 571 } 572 if (unp->unp_addr != NULL) 573 sa = (struct sockaddr *) unp->unp_addr; 574 else 575 sa = &sun_noname; 576 bcopy(sa, *nam, sa->sa_len); 577 UNP_UNLOCK(); 578 return (0); 579 } 580 581 struct pr_usrreqs uipc_usrreqs = { 582 .pru_abort = uipc_abort, 583 .pru_accept = uipc_accept, 584 .pru_attach = uipc_attach, 585 .pru_bind = uipc_bind, 586 .pru_connect = uipc_connect, 587 .pru_connect2 = uipc_connect2, 588 .pru_detach = uipc_detach, 589 .pru_disconnect = uipc_disconnect, 590 .pru_listen = uipc_listen, 591 .pru_peeraddr = uipc_peeraddr, 592 .pru_rcvd = uipc_rcvd, 593 .pru_send = uipc_send, 594 .pru_sense = uipc_sense, 595 .pru_shutdown = uipc_shutdown, 596 .pru_sockaddr = uipc_sockaddr, 597 .pru_sosend = sosend, 598 .pru_soreceive = soreceive, 599 .pru_sopoll = sopoll, 600 }; 601 602 int 603 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 604 { 605 struct unpcb *unp; 606 struct xucred xu; 607 int error; 608 609 switch (sopt->sopt_dir) { 610 case SOPT_GET: 611 switch (sopt->sopt_name) { 612 case LOCAL_PEERCRED: 613 error = 0; 614 UNP_LOCK(); 615 unp = sotounpcb(so); 616 if (unp == NULL) { 617 UNP_UNLOCK(); 618 error = EINVAL; 619 break; 620 } 621 if (unp->unp_flags & UNP_HAVEPC) 622 xu = unp->unp_peercred; 623 else { 624 if (so->so_type == SOCK_STREAM) 625 error = ENOTCONN; 626 else 627 error = EINVAL; 628 } 629 UNP_UNLOCK(); 630 if (error == 0) 631 error = sooptcopyout(sopt, &xu, sizeof(xu)); 632 break; 633 default: 634 error = EOPNOTSUPP; 635 break; 636 } 637 break; 638 case SOPT_SET: 639 default: 640 error = EOPNOTSUPP; 641 break; 642 } 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_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 666 &unpst_sendspace, 0, ""); 667 SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 668 &unpst_recvspace, 0, ""); 669 SYSCTL_DECL(_net_local_dgram); 670 SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 671 &unpdg_sendspace, 0, ""); 672 SYSCTL_INT(_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 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 684 switch (so->so_type) { 685 686 case SOCK_STREAM: 687 error = soreserve(so, unpst_sendspace, unpst_recvspace); 688 break; 689 690 case SOCK_DGRAM: 691 error = soreserve(so, unpdg_sendspace, unpdg_recvspace); 692 break; 693 694 default: 695 panic("unp_attach"); 696 } 697 if (error) 698 return (error); 699 } 700 unp = uma_zalloc(unp_zone, M_WAITOK | M_ZERO); 701 if (unp == NULL) 702 return (ENOBUFS); 703 LIST_INIT(&unp->unp_refs); 704 unp->unp_socket = so; 705 so->so_pcb = unp; 706 707 UNP_LOCK(); 708 unp->unp_gencnt = ++unp_gencnt; 709 unp_count++; 710 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead 711 : &unp_shead, unp, unp_link); 712 UNP_UNLOCK(); 713 714 return (0); 715 } 716 717 static void 718 unp_detach(struct unpcb *unp) 719 { 720 struct vnode *vp; 721 722 UNP_LOCK_ASSERT(); 723 724 LIST_REMOVE(unp, unp_link); 725 unp->unp_gencnt = ++unp_gencnt; 726 --unp_count; 727 if ((vp = unp->unp_vnode) != NULL) { 728 /* 729 * XXXRW: should v_socket be frobbed only while holding 730 * Giant? 731 */ 732 unp->unp_vnode->v_socket = NULL; 733 unp->unp_vnode = NULL; 734 } 735 if (unp->unp_conn != NULL) 736 unp_disconnect(unp); 737 while (!LIST_EMPTY(&unp->unp_refs)) { 738 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 739 unp_drop(ref, ECONNRESET); 740 } 741 soisdisconnected(unp->unp_socket); 742 unp->unp_socket->so_pcb = NULL; 743 if (unp_rights) { 744 /* 745 * Normally the receive buffer is flushed later, 746 * in sofree, but if our receive buffer holds references 747 * to descriptors that are now garbage, we will dispose 748 * of those descriptor references after the garbage collector 749 * gets them (resulting in a "panic: closef: count < 0"). 750 */ 751 sorflush(unp->unp_socket); 752 unp_gc(); /* Will unlock UNP. */ 753 } else 754 UNP_UNLOCK(); 755 UNP_UNLOCK_ASSERT(); 756 if (unp->unp_addr != NULL) 757 FREE(unp->unp_addr, M_SONAME); 758 uma_zfree(unp_zone, unp); 759 if (vp) { 760 mtx_lock(&Giant); 761 vrele(vp); 762 mtx_unlock(&Giant); 763 } 764 } 765 766 static int 767 unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td) 768 { 769 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 770 struct vnode *vp; 771 struct mount *mp; 772 struct vattr vattr; 773 int error, namelen; 774 struct nameidata nd; 775 char *buf; 776 777 UNP_LOCK_ASSERT(); 778 779 /* 780 * XXXRW: This test-and-set of unp_vnode is non-atomic; the 781 * unlocked read here is fine, but the value of unp_vnode needs 782 * to be tested again after we do all the lookups to see if the 783 * pcb is still unbound? 784 */ 785 if (unp->unp_vnode != NULL) 786 return (EINVAL); 787 788 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 789 if (namelen <= 0) 790 return (EINVAL); 791 792 UNP_UNLOCK(); 793 794 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 795 strlcpy(buf, soun->sun_path, namelen + 1); 796 797 mtx_lock(&Giant); 798 restart: 799 mtx_assert(&Giant, MA_OWNED); 800 NDINIT(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME, UIO_SYSSPACE, 801 buf, td); 802 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 803 error = namei(&nd); 804 if (error) 805 goto done; 806 vp = nd.ni_vp; 807 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 808 NDFREE(&nd, NDF_ONLY_PNBUF); 809 if (nd.ni_dvp == vp) 810 vrele(nd.ni_dvp); 811 else 812 vput(nd.ni_dvp); 813 if (vp != NULL) { 814 vrele(vp); 815 error = EADDRINUSE; 816 goto done; 817 } 818 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 819 if (error) 820 goto done; 821 goto restart; 822 } 823 VATTR_NULL(&vattr); 824 vattr.va_type = VSOCK; 825 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 826 #ifdef MAC 827 error = mac_check_vnode_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 828 &vattr); 829 #endif 830 if (error == 0) { 831 VOP_LEASE(nd.ni_dvp, td, td->td_ucred, LEASE_WRITE); 832 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 833 } 834 NDFREE(&nd, NDF_ONLY_PNBUF); 835 vput(nd.ni_dvp); 836 if (error) { 837 vn_finished_write(mp); 838 goto done; 839 } 840 vp = nd.ni_vp; 841 ASSERT_VOP_LOCKED(vp, "unp_bind"); 842 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 843 UNP_LOCK(); 844 vp->v_socket = unp->unp_socket; 845 unp->unp_vnode = vp; 846 unp->unp_addr = soun; 847 UNP_UNLOCK(); 848 VOP_UNLOCK(vp, 0, td); 849 vn_finished_write(mp); 850 done: 851 mtx_unlock(&Giant); 852 free(buf, M_TEMP); 853 UNP_LOCK(); 854 return (error); 855 } 856 857 static int 858 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 859 { 860 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 861 struct vnode *vp; 862 struct socket *so2, *so3; 863 struct unpcb *unp, *unp2, *unp3; 864 int error, len; 865 struct nameidata nd; 866 char buf[SOCK_MAXADDRLEN]; 867 struct sockaddr *sa; 868 869 UNP_LOCK_ASSERT(); 870 unp = sotounpcb(so); 871 872 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 873 if (len <= 0) 874 return (EINVAL); 875 strlcpy(buf, soun->sun_path, len + 1); 876 UNP_UNLOCK(); 877 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 878 mtx_lock(&Giant); 879 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, td); 880 error = namei(&nd); 881 if (error) 882 vp = NULL; 883 else 884 vp = nd.ni_vp; 885 ASSERT_VOP_LOCKED(vp, "unp_connect"); 886 NDFREE(&nd, NDF_ONLY_PNBUF); 887 if (error) 888 goto bad; 889 890 if (vp->v_type != VSOCK) { 891 error = ENOTSOCK; 892 goto bad; 893 } 894 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 895 if (error) 896 goto bad; 897 mtx_unlock(&Giant); 898 UNP_LOCK(); 899 unp = sotounpcb(so); 900 if (unp == NULL) { 901 error = EINVAL; 902 goto bad2; 903 } 904 so2 = vp->v_socket; 905 if (so2 == NULL) { 906 error = ECONNREFUSED; 907 goto bad2; 908 } 909 if (so->so_type != so2->so_type) { 910 error = EPROTOTYPE; 911 goto bad2; 912 } 913 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 914 if (so2->so_options & SO_ACCEPTCONN) { 915 /* 916 * NB: drop locks here so unp_attach is entered 917 * w/o locks; this avoids a recursive lock 918 * of the head and holding sleep locks across 919 * a (potentially) blocking malloc. 920 */ 921 UNP_UNLOCK(); 922 so3 = sonewconn(so2, 0); 923 UNP_LOCK(); 924 } else 925 so3 = NULL; 926 if (so3 == NULL) { 927 error = ECONNREFUSED; 928 goto bad2; 929 } 930 unp = sotounpcb(so); 931 unp2 = sotounpcb(so2); 932 unp3 = sotounpcb(so3); 933 if (unp2->unp_addr != NULL) { 934 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 935 unp3->unp_addr = (struct sockaddr_un *) sa; 936 sa = NULL; 937 } 938 /* 939 * unp_peercred management: 940 * 941 * The connecter's (client's) credentials are copied 942 * from its process structure at the time of connect() 943 * (which is now). 944 */ 945 cru2x(td->td_ucred, &unp3->unp_peercred); 946 unp3->unp_flags |= UNP_HAVEPC; 947 /* 948 * The receiver's (server's) credentials are copied 949 * from the unp_peercred member of socket on which the 950 * former called listen(); unp_listen() cached that 951 * process's credentials at that time so we can use 952 * them now. 953 */ 954 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 955 ("unp_connect: listener without cached peercred")); 956 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 957 sizeof(unp->unp_peercred)); 958 unp->unp_flags |= UNP_HAVEPC; 959 #ifdef MAC 960 SOCK_LOCK(so); 961 mac_set_socket_peer_from_socket(so, so3); 962 mac_set_socket_peer_from_socket(so3, so); 963 SOCK_UNLOCK(so); 964 #endif 965 966 so2 = so3; 967 } 968 error = unp_connect2(so, so2); 969 bad2: 970 UNP_UNLOCK(); 971 mtx_lock(&Giant); 972 bad: 973 mtx_assert(&Giant, MA_OWNED); 974 if (vp != NULL) 975 vput(vp); 976 mtx_unlock(&Giant); 977 free(sa, M_SONAME); 978 UNP_LOCK(); 979 return (error); 980 } 981 982 static int 983 unp_connect2(struct socket *so, struct socket *so2) 984 { 985 struct unpcb *unp = sotounpcb(so); 986 struct unpcb *unp2; 987 988 UNP_LOCK_ASSERT(); 989 990 if (so2->so_type != so->so_type) 991 return (EPROTOTYPE); 992 unp2 = sotounpcb(so2); 993 unp->unp_conn = unp2; 994 switch (so->so_type) { 995 996 case SOCK_DGRAM: 997 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 998 soisconnected(so); 999 break; 1000 1001 case SOCK_STREAM: 1002 unp2->unp_conn = unp; 1003 soisconnected(so); 1004 soisconnected(so2); 1005 break; 1006 1007 default: 1008 panic("unp_connect2"); 1009 } 1010 return (0); 1011 } 1012 1013 static void 1014 unp_disconnect(struct unpcb *unp) 1015 { 1016 struct unpcb *unp2 = unp->unp_conn; 1017 struct socket *so; 1018 1019 UNP_LOCK_ASSERT(); 1020 1021 if (unp2 == NULL) 1022 return; 1023 unp->unp_conn = NULL; 1024 switch (unp->unp_socket->so_type) { 1025 1026 case SOCK_DGRAM: 1027 LIST_REMOVE(unp, unp_reflink); 1028 so = unp->unp_socket; 1029 SOCK_LOCK(so); 1030 so->so_state &= ~SS_ISCONNECTED; 1031 SOCK_UNLOCK(so); 1032 break; 1033 1034 case SOCK_STREAM: 1035 soisdisconnected(unp->unp_socket); 1036 unp2->unp_conn = NULL; 1037 soisdisconnected(unp2->unp_socket); 1038 break; 1039 } 1040 } 1041 1042 #ifdef notdef 1043 void 1044 unp_abort(struct unpcb *unp) 1045 { 1046 1047 unp_detach(unp); 1048 UNP_UNLOCK_ASSERT(); 1049 } 1050 #endif 1051 1052 /* 1053 * unp_pcblist() assumes that UNIX domain socket memory is never reclaimed 1054 * by the zone (UMA_ZONE_NOFREE), and as such potentially stale pointers 1055 * are safe to reference. It first scans the list of struct unpcb's to 1056 * generate a pointer list, then it rescans its list one entry at a time to 1057 * externalize and copyout. It checks the generation number to see if a 1058 * struct unpcb has been reused, and will skip it if so. 1059 */ 1060 static int 1061 unp_pcblist(SYSCTL_HANDLER_ARGS) 1062 { 1063 int error, i, n; 1064 struct unpcb *unp, **unp_list; 1065 unp_gen_t gencnt; 1066 struct xunpgen *xug; 1067 struct unp_head *head; 1068 struct xunpcb *xu; 1069 1070 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 1071 1072 /* 1073 * The process of preparing the PCB list is too time-consuming and 1074 * resource-intensive to repeat twice on every request. 1075 */ 1076 if (req->oldptr == NULL) { 1077 n = unp_count; 1078 req->oldidx = 2 * (sizeof *xug) 1079 + (n + n/8) * sizeof(struct xunpcb); 1080 return (0); 1081 } 1082 1083 if (req->newptr != NULL) 1084 return (EPERM); 1085 1086 /* 1087 * OK, now we're committed to doing something. 1088 */ 1089 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1090 UNP_LOCK(); 1091 gencnt = unp_gencnt; 1092 n = unp_count; 1093 UNP_UNLOCK(); 1094 1095 xug->xug_len = sizeof *xug; 1096 xug->xug_count = n; 1097 xug->xug_gen = gencnt; 1098 xug->xug_sogen = so_gencnt; 1099 error = SYSCTL_OUT(req, xug, sizeof *xug); 1100 if (error) { 1101 free(xug, M_TEMP); 1102 return (error); 1103 } 1104 1105 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1106 1107 UNP_LOCK(); 1108 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1109 unp = LIST_NEXT(unp, unp_link)) { 1110 if (unp->unp_gencnt <= gencnt) { 1111 if (cr_cansee(req->td->td_ucred, 1112 unp->unp_socket->so_cred)) 1113 continue; 1114 unp_list[i++] = unp; 1115 } 1116 } 1117 UNP_UNLOCK(); 1118 n = i; /* in case we lost some during malloc */ 1119 1120 error = 0; 1121 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK); 1122 for (i = 0; i < n; i++) { 1123 unp = unp_list[i]; 1124 if (unp->unp_gencnt <= gencnt) { 1125 xu->xu_len = sizeof *xu; 1126 xu->xu_unpp = unp; 1127 /* 1128 * XXX - need more locking here to protect against 1129 * connect/disconnect races for SMP. 1130 */ 1131 if (unp->unp_addr != NULL) 1132 bcopy(unp->unp_addr, &xu->xu_addr, 1133 unp->unp_addr->sun_len); 1134 if (unp->unp_conn != NULL && 1135 unp->unp_conn->unp_addr != NULL) 1136 bcopy(unp->unp_conn->unp_addr, 1137 &xu->xu_caddr, 1138 unp->unp_conn->unp_addr->sun_len); 1139 bcopy(unp, &xu->xu_unp, sizeof *unp); 1140 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1141 error = SYSCTL_OUT(req, xu, sizeof *xu); 1142 } 1143 } 1144 free(xu, M_TEMP); 1145 if (!error) { 1146 /* 1147 * Give the user an updated idea of our state. 1148 * If the generation differs from what we told 1149 * her before, she knows that something happened 1150 * while we were processing this request, and it 1151 * might be necessary to retry. 1152 */ 1153 xug->xug_gen = unp_gencnt; 1154 xug->xug_sogen = so_gencnt; 1155 xug->xug_count = unp_count; 1156 error = SYSCTL_OUT(req, xug, sizeof *xug); 1157 } 1158 free(unp_list, M_TEMP); 1159 free(xug, M_TEMP); 1160 return (error); 1161 } 1162 1163 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 1164 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1165 "List of active local datagram sockets"); 1166 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 1167 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1168 "List of active local stream sockets"); 1169 1170 static void 1171 unp_shutdown(struct unpcb *unp) 1172 { 1173 struct socket *so; 1174 1175 UNP_LOCK_ASSERT(); 1176 1177 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn && 1178 (so = unp->unp_conn->unp_socket)) 1179 socantrcvmore(so); 1180 } 1181 1182 static void 1183 unp_drop(struct unpcb *unp, int errno) 1184 { 1185 struct socket *so = unp->unp_socket; 1186 1187 UNP_LOCK_ASSERT(); 1188 1189 so->so_error = errno; 1190 unp_disconnect(unp); 1191 } 1192 1193 #ifdef notdef 1194 void 1195 unp_drain(void) 1196 { 1197 1198 } 1199 #endif 1200 1201 static void 1202 unp_freerights(struct file **rp, int fdcount) 1203 { 1204 int i; 1205 struct file *fp; 1206 1207 for (i = 0; i < fdcount; i++) { 1208 fp = *rp; 1209 /* 1210 * zero the pointer before calling 1211 * unp_discard since it may end up 1212 * in unp_gc().. 1213 */ 1214 *rp++ = 0; 1215 unp_discard(fp); 1216 } 1217 } 1218 1219 int 1220 unp_externalize(struct mbuf *control, struct mbuf **controlp) 1221 { 1222 struct thread *td = curthread; /* XXX */ 1223 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1224 int i; 1225 int *fdp; 1226 struct file **rp; 1227 struct file *fp; 1228 void *data; 1229 socklen_t clen = control->m_len, datalen; 1230 int error, newfds; 1231 int f; 1232 u_int newlen; 1233 1234 UNP_UNLOCK_ASSERT(); 1235 1236 error = 0; 1237 if (controlp != NULL) /* controlp == NULL => free control messages */ 1238 *controlp = NULL; 1239 1240 while (cm != NULL) { 1241 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1242 error = EINVAL; 1243 break; 1244 } 1245 1246 data = CMSG_DATA(cm); 1247 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1248 1249 if (cm->cmsg_level == SOL_SOCKET 1250 && cm->cmsg_type == SCM_RIGHTS) { 1251 newfds = datalen / sizeof(struct file *); 1252 rp = data; 1253 1254 /* If we're not outputting the descriptors free them. */ 1255 if (error || controlp == NULL) { 1256 unp_freerights(rp, newfds); 1257 goto next; 1258 } 1259 FILEDESC_LOCK(td->td_proc->p_fd); 1260 /* if the new FD's will not fit free them. */ 1261 if (!fdavail(td, newfds)) { 1262 FILEDESC_UNLOCK(td->td_proc->p_fd); 1263 error = EMSGSIZE; 1264 unp_freerights(rp, newfds); 1265 goto next; 1266 } 1267 /* 1268 * now change each pointer to an fd in the global 1269 * table to an integer that is the index to the 1270 * local fd table entry that we set up to point 1271 * to the global one we are transferring. 1272 */ 1273 newlen = newfds * sizeof(int); 1274 *controlp = sbcreatecontrol(NULL, newlen, 1275 SCM_RIGHTS, SOL_SOCKET); 1276 if (*controlp == NULL) { 1277 FILEDESC_UNLOCK(td->td_proc->p_fd); 1278 error = E2BIG; 1279 unp_freerights(rp, newfds); 1280 goto next; 1281 } 1282 1283 fdp = (int *) 1284 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1285 for (i = 0; i < newfds; i++) { 1286 if (fdalloc(td, 0, &f)) 1287 panic("unp_externalize fdalloc failed"); 1288 fp = *rp++; 1289 td->td_proc->p_fd->fd_ofiles[f] = fp; 1290 FILE_LOCK(fp); 1291 fp->f_msgcount--; 1292 FILE_UNLOCK(fp); 1293 unp_rights--; 1294 *fdp++ = f; 1295 } 1296 FILEDESC_UNLOCK(td->td_proc->p_fd); 1297 } else { /* We can just copy anything else across */ 1298 if (error || controlp == NULL) 1299 goto next; 1300 *controlp = sbcreatecontrol(NULL, datalen, 1301 cm->cmsg_type, cm->cmsg_level); 1302 if (*controlp == NULL) { 1303 error = ENOBUFS; 1304 goto next; 1305 } 1306 bcopy(data, 1307 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1308 datalen); 1309 } 1310 1311 controlp = &(*controlp)->m_next; 1312 1313 next: 1314 if (CMSG_SPACE(datalen) < clen) { 1315 clen -= CMSG_SPACE(datalen); 1316 cm = (struct cmsghdr *) 1317 ((caddr_t)cm + CMSG_SPACE(datalen)); 1318 } else { 1319 clen = 0; 1320 cm = NULL; 1321 } 1322 } 1323 1324 m_freem(control); 1325 1326 return (error); 1327 } 1328 1329 void 1330 unp_init(void) 1331 { 1332 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1333 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 1334 if (unp_zone == NULL) 1335 panic("unp_init"); 1336 uma_zone_set_max(unp_zone, nmbclusters); 1337 LIST_INIT(&unp_dhead); 1338 LIST_INIT(&unp_shead); 1339 1340 UNP_LOCK_INIT(); 1341 } 1342 1343 static int 1344 unp_internalize(struct mbuf **controlp, struct thread *td) 1345 { 1346 struct mbuf *control = *controlp; 1347 struct proc *p = td->td_proc; 1348 struct filedesc *fdescp = p->p_fd; 1349 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1350 struct cmsgcred *cmcred; 1351 struct file **rp; 1352 struct file *fp; 1353 struct timeval *tv; 1354 int i, fd, *fdp; 1355 void *data; 1356 socklen_t clen = control->m_len, datalen; 1357 int error, oldfds; 1358 u_int newlen; 1359 1360 UNP_UNLOCK_ASSERT(); 1361 1362 error = 0; 1363 *controlp = NULL; 1364 1365 while (cm != NULL) { 1366 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1367 || cm->cmsg_len > clen) { 1368 error = EINVAL; 1369 goto out; 1370 } 1371 1372 data = CMSG_DATA(cm); 1373 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1374 1375 switch (cm->cmsg_type) { 1376 /* 1377 * Fill in credential information. 1378 */ 1379 case SCM_CREDS: 1380 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1381 SCM_CREDS, SOL_SOCKET); 1382 if (*controlp == NULL) { 1383 error = ENOBUFS; 1384 goto out; 1385 } 1386 1387 cmcred = (struct cmsgcred *) 1388 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1389 cmcred->cmcred_pid = p->p_pid; 1390 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1391 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1392 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1393 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1394 CMGROUP_MAX); 1395 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1396 cmcred->cmcred_groups[i] = 1397 td->td_ucred->cr_groups[i]; 1398 break; 1399 1400 case SCM_RIGHTS: 1401 oldfds = datalen / sizeof (int); 1402 /* 1403 * check that all the FDs passed in refer to legal files 1404 * If not, reject the entire operation. 1405 */ 1406 fdp = data; 1407 FILEDESC_LOCK(fdescp); 1408 for (i = 0; i < oldfds; i++) { 1409 fd = *fdp++; 1410 if ((unsigned)fd >= fdescp->fd_nfiles || 1411 fdescp->fd_ofiles[fd] == NULL) { 1412 FILEDESC_UNLOCK(fdescp); 1413 error = EBADF; 1414 goto out; 1415 } 1416 fp = fdescp->fd_ofiles[fd]; 1417 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1418 FILEDESC_UNLOCK(fdescp); 1419 error = EOPNOTSUPP; 1420 goto out; 1421 } 1422 1423 } 1424 /* 1425 * Now replace the integer FDs with pointers to 1426 * the associated global file table entry.. 1427 */ 1428 newlen = oldfds * sizeof(struct file *); 1429 *controlp = sbcreatecontrol(NULL, newlen, 1430 SCM_RIGHTS, SOL_SOCKET); 1431 if (*controlp == NULL) { 1432 FILEDESC_UNLOCK(fdescp); 1433 error = E2BIG; 1434 goto out; 1435 } 1436 1437 fdp = data; 1438 rp = (struct file **) 1439 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1440 for (i = 0; i < oldfds; i++) { 1441 fp = fdescp->fd_ofiles[*fdp++]; 1442 *rp++ = fp; 1443 FILE_LOCK(fp); 1444 fp->f_count++; 1445 fp->f_msgcount++; 1446 FILE_UNLOCK(fp); 1447 unp_rights++; 1448 } 1449 FILEDESC_UNLOCK(fdescp); 1450 break; 1451 1452 case SCM_TIMESTAMP: 1453 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1454 SCM_TIMESTAMP, SOL_SOCKET); 1455 if (*controlp == NULL) { 1456 error = ENOBUFS; 1457 goto out; 1458 } 1459 tv = (struct timeval *) 1460 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1461 microtime(tv); 1462 break; 1463 1464 default: 1465 error = EINVAL; 1466 goto out; 1467 } 1468 1469 controlp = &(*controlp)->m_next; 1470 1471 if (CMSG_SPACE(datalen) < clen) { 1472 clen -= CMSG_SPACE(datalen); 1473 cm = (struct cmsghdr *) 1474 ((caddr_t)cm + CMSG_SPACE(datalen)); 1475 } else { 1476 clen = 0; 1477 cm = NULL; 1478 } 1479 } 1480 1481 out: 1482 m_freem(control); 1483 1484 return (error); 1485 } 1486 1487 /* 1488 * unp_defer is thread-local during garbage collection, and does not require 1489 * explicit synchronization. unp_gcing prevents other threads from entering 1490 * garbage collection, and perhaps should be an sx lock instead. 1491 */ 1492 static int unp_defer, unp_gcing; 1493 1494 static void 1495 unp_gc(void) 1496 { 1497 struct file *fp, *nextfp; 1498 struct socket *so; 1499 struct file **extra_ref, **fpp; 1500 int nunref, i; 1501 int nfiles_snap; 1502 int nfiles_slack = 20; 1503 1504 UNP_LOCK_ASSERT(); 1505 1506 if (unp_gcing) { 1507 UNP_UNLOCK(); 1508 return; 1509 } 1510 unp_gcing = 1; 1511 unp_defer = 0; 1512 UNP_UNLOCK(); 1513 /* 1514 * before going through all this, set all FDs to 1515 * be NOT defered and NOT externally accessible 1516 */ 1517 sx_slock(&filelist_lock); 1518 LIST_FOREACH(fp, &filehead, f_list) 1519 fp->f_gcflag &= ~(FMARK|FDEFER); 1520 do { 1521 LIST_FOREACH(fp, &filehead, f_list) { 1522 FILE_LOCK(fp); 1523 /* 1524 * If the file is not open, skip it 1525 */ 1526 if (fp->f_count == 0) { 1527 FILE_UNLOCK(fp); 1528 continue; 1529 } 1530 /* 1531 * If we already marked it as 'defer' in a 1532 * previous pass, then try process it this time 1533 * and un-mark it 1534 */ 1535 if (fp->f_gcflag & FDEFER) { 1536 fp->f_gcflag &= ~FDEFER; 1537 unp_defer--; 1538 } else { 1539 /* 1540 * if it's not defered, then check if it's 1541 * already marked.. if so skip it 1542 */ 1543 if (fp->f_gcflag & FMARK) { 1544 FILE_UNLOCK(fp); 1545 continue; 1546 } 1547 /* 1548 * If all references are from messages 1549 * in transit, then skip it. it's not 1550 * externally accessible. 1551 */ 1552 if (fp->f_count == fp->f_msgcount) { 1553 FILE_UNLOCK(fp); 1554 continue; 1555 } 1556 /* 1557 * If it got this far then it must be 1558 * externally accessible. 1559 */ 1560 fp->f_gcflag |= FMARK; 1561 } 1562 /* 1563 * either it was defered, or it is externally 1564 * accessible and not already marked so. 1565 * Now check if it is possibly one of OUR sockets. 1566 */ 1567 if (fp->f_type != DTYPE_SOCKET || 1568 (so = fp->f_data) == NULL) { 1569 FILE_UNLOCK(fp); 1570 continue; 1571 } 1572 FILE_UNLOCK(fp); 1573 if (so->so_proto->pr_domain != &localdomain || 1574 (so->so_proto->pr_flags&PR_RIGHTS) == 0) 1575 continue; 1576 #ifdef notdef 1577 if (so->so_rcv.sb_flags & SB_LOCK) { 1578 /* 1579 * This is problematical; it's not clear 1580 * we need to wait for the sockbuf to be 1581 * unlocked (on a uniprocessor, at least), 1582 * and it's also not clear what to do 1583 * if sbwait returns an error due to receipt 1584 * of a signal. If sbwait does return 1585 * an error, we'll go into an infinite 1586 * loop. Delete all of this for now. 1587 */ 1588 (void) sbwait(&so->so_rcv); 1589 goto restart; 1590 } 1591 #endif 1592 /* 1593 * So, Ok, it's one of our sockets and it IS externally 1594 * accessible (or was defered). Now we look 1595 * to see if we hold any file descriptors in its 1596 * message buffers. Follow those links and mark them 1597 * as accessible too. 1598 */ 1599 SOCKBUF_LOCK(&so->so_rcv); 1600 unp_scan(so->so_rcv.sb_mb, unp_mark); 1601 SOCKBUF_UNLOCK(&so->so_rcv); 1602 } 1603 } while (unp_defer); 1604 sx_sunlock(&filelist_lock); 1605 /* 1606 * We grab an extra reference to each of the file table entries 1607 * that are not otherwise accessible and then free the rights 1608 * that are stored in messages on them. 1609 * 1610 * The bug in the orginal code is a little tricky, so I'll describe 1611 * what's wrong with it here. 1612 * 1613 * It is incorrect to simply unp_discard each entry for f_msgcount 1614 * times -- consider the case of sockets A and B that contain 1615 * references to each other. On a last close of some other socket, 1616 * we trigger a gc since the number of outstanding rights (unp_rights) 1617 * is non-zero. If during the sweep phase the gc code un_discards, 1618 * we end up doing a (full) closef on the descriptor. A closef on A 1619 * results in the following chain. Closef calls soo_close, which 1620 * calls soclose. Soclose calls first (through the switch 1621 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply 1622 * returns because the previous instance had set unp_gcing, and 1623 * we return all the way back to soclose, which marks the socket 1624 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush 1625 * to free up the rights that are queued in messages on the socket A, 1626 * i.e., the reference on B. The sorflush calls via the dom_dispose 1627 * switch unp_dispose, which unp_scans with unp_discard. This second 1628 * instance of unp_discard just calls closef on B. 1629 * 1630 * Well, a similar chain occurs on B, resulting in a sorflush on B, 1631 * which results in another closef on A. Unfortunately, A is already 1632 * being closed, and the descriptor has already been marked with 1633 * SS_NOFDREF, and soclose panics at this point. 1634 * 1635 * Here, we first take an extra reference to each inaccessible 1636 * descriptor. Then, we call sorflush ourself, since we know 1637 * it is a Unix domain socket anyhow. After we destroy all the 1638 * rights carried in messages, we do a last closef to get rid 1639 * of our extra reference. This is the last close, and the 1640 * unp_detach etc will shut down the socket. 1641 * 1642 * 91/09/19, bsy@cs.cmu.edu 1643 */ 1644 again: 1645 nfiles_snap = openfiles + nfiles_slack; /* some slack */ 1646 extra_ref = malloc(nfiles_snap * sizeof(struct file *), M_TEMP, 1647 M_WAITOK); 1648 sx_slock(&filelist_lock); 1649 if (nfiles_snap < openfiles) { 1650 sx_sunlock(&filelist_lock); 1651 free(extra_ref, M_TEMP); 1652 nfiles_slack += 20; 1653 goto again; 1654 } 1655 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; 1656 fp != NULL; fp = nextfp) { 1657 nextfp = LIST_NEXT(fp, f_list); 1658 FILE_LOCK(fp); 1659 /* 1660 * If it's not open, skip it 1661 */ 1662 if (fp->f_count == 0) { 1663 FILE_UNLOCK(fp); 1664 continue; 1665 } 1666 /* 1667 * If all refs are from msgs, and it's not marked accessible 1668 * then it must be referenced from some unreachable cycle 1669 * of (shut-down) FDs, so include it in our 1670 * list of FDs to remove 1671 */ 1672 if (fp->f_count == fp->f_msgcount && !(fp->f_gcflag & FMARK)) { 1673 *fpp++ = fp; 1674 nunref++; 1675 fp->f_count++; 1676 } 1677 FILE_UNLOCK(fp); 1678 } 1679 sx_sunlock(&filelist_lock); 1680 /* 1681 * for each FD on our hit list, do the following two things 1682 */ 1683 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) { 1684 struct file *tfp = *fpp; 1685 FILE_LOCK(tfp); 1686 if (tfp->f_type == DTYPE_SOCKET && 1687 tfp->f_data != NULL) { 1688 FILE_UNLOCK(tfp); 1689 sorflush(tfp->f_data); 1690 } else { 1691 FILE_UNLOCK(tfp); 1692 } 1693 } 1694 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) 1695 closef(*fpp, (struct thread *) NULL); 1696 free(extra_ref, M_TEMP); 1697 unp_gcing = 0; 1698 1699 UNP_UNLOCK_ASSERT(); 1700 } 1701 1702 void 1703 unp_dispose(struct mbuf *m) 1704 { 1705 1706 if (m) 1707 unp_scan(m, unp_discard); 1708 } 1709 1710 static int 1711 unp_listen(struct socket *so, struct unpcb *unp, struct thread *td) 1712 { 1713 int error; 1714 1715 UNP_LOCK_ASSERT(); 1716 1717 SOCK_LOCK(so); 1718 error = solisten_proto_check(so); 1719 if (error == 0) { 1720 cru2x(td->td_ucred, &unp->unp_peercred); 1721 unp->unp_flags |= UNP_HAVEPCCACHED; 1722 solisten_proto(so); 1723 } 1724 SOCK_UNLOCK(so); 1725 return (error); 1726 } 1727 1728 static void 1729 unp_scan(struct mbuf *m0, void (*op)(struct file *)) 1730 { 1731 struct mbuf *m; 1732 struct file **rp; 1733 struct cmsghdr *cm; 1734 void *data; 1735 int i; 1736 socklen_t clen, datalen; 1737 int qfds; 1738 1739 while (m0 != NULL) { 1740 for (m = m0; m; m = m->m_next) { 1741 if (m->m_type != MT_CONTROL) 1742 continue; 1743 1744 cm = mtod(m, struct cmsghdr *); 1745 clen = m->m_len; 1746 1747 while (cm != NULL) { 1748 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 1749 break; 1750 1751 data = CMSG_DATA(cm); 1752 datalen = (caddr_t)cm + cm->cmsg_len 1753 - (caddr_t)data; 1754 1755 if (cm->cmsg_level == SOL_SOCKET && 1756 cm->cmsg_type == SCM_RIGHTS) { 1757 qfds = datalen / sizeof (struct file *); 1758 rp = data; 1759 for (i = 0; i < qfds; i++) 1760 (*op)(*rp++); 1761 } 1762 1763 if (CMSG_SPACE(datalen) < clen) { 1764 clen -= CMSG_SPACE(datalen); 1765 cm = (struct cmsghdr *) 1766 ((caddr_t)cm + CMSG_SPACE(datalen)); 1767 } else { 1768 clen = 0; 1769 cm = NULL; 1770 } 1771 } 1772 } 1773 m0 = m0->m_act; 1774 } 1775 } 1776 1777 static void 1778 unp_mark(struct file *fp) 1779 { 1780 if (fp->f_gcflag & FMARK) 1781 return; 1782 unp_defer++; 1783 fp->f_gcflag |= (FMARK|FDEFER); 1784 } 1785 1786 static void 1787 unp_discard(struct file *fp) 1788 { 1789 FILE_LOCK(fp); 1790 fp->f_msgcount--; 1791 unp_rights--; 1792 FILE_UNLOCK(fp); 1793 (void) closef(fp, (struct thread *)NULL); 1794 } 1795