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 struct mbuf *unp_addsockcred(struct thread *, struct mbuf *); 85 86 /* 87 * Currently, UNIX domain sockets are protected by a single subsystem lock, 88 * which covers global data structures and variables, the contents of each 89 * per-socket unpcb structure, and the so_pcb field in sockets attached to 90 * the UNIX domain. This provides for a moderate degree of paralellism, as 91 * receive operations on UNIX domain sockets do not need to acquire the 92 * subsystem lock. Finer grained locking to permit send() without acquiring 93 * a global lock would be a logical next step. 94 * 95 * The UNIX domain socket lock preceds all socket layer locks, including the 96 * socket lock and socket buffer lock, permitting UNIX domain socket code to 97 * call into socket support routines without releasing its locks. 98 * 99 * Some caution is required in areas where the UNIX domain socket code enters 100 * VFS in order to create or find rendezvous points. This results in 101 * dropping of the UNIX domain socket subsystem lock, acquisition of the 102 * Giant lock, and potential sleeping. This increases the chances of races, 103 * and exposes weaknesses in the socket->protocol API by offering poor 104 * failure modes. 105 */ 106 static struct mtx unp_mtx; 107 #define UNP_LOCK_INIT() \ 108 mtx_init(&unp_mtx, "unp", NULL, MTX_DEF) 109 #define UNP_LOCK() mtx_lock(&unp_mtx) 110 #define UNP_UNLOCK() mtx_unlock(&unp_mtx) 111 #define UNP_LOCK_ASSERT() mtx_assert(&unp_mtx, MA_OWNED) 112 #define UNP_UNLOCK_ASSERT() mtx_assert(&unp_mtx, MA_NOTOWNED) 113 114 static int unp_attach(struct socket *); 115 static void unp_detach(struct unpcb *); 116 static int unp_bind(struct unpcb *,struct sockaddr *, struct thread *); 117 static int unp_connect(struct socket *,struct sockaddr *, struct thread *); 118 static int unp_connect2(struct socket *so, struct socket *so2, int); 119 static void unp_disconnect(struct unpcb *); 120 static void unp_shutdown(struct unpcb *); 121 static void unp_drop(struct unpcb *, int); 122 static void unp_gc(void); 123 static void unp_scan(struct mbuf *, void (*)(struct file *)); 124 static void unp_mark(struct file *); 125 static void unp_discard(struct file *); 126 static void unp_freerights(struct file **, int); 127 static int unp_internalize(struct mbuf **, struct thread *); 128 static int unp_listen(struct socket *, struct unpcb *, struct thread *); 129 130 static int 131 uipc_abort(struct socket *so) 132 { 133 struct unpcb *unp; 134 135 UNP_LOCK(); 136 unp = sotounpcb(so); 137 if (unp == NULL) { 138 UNP_UNLOCK(); 139 return (EINVAL); 140 } 141 unp_drop(unp, ECONNABORTED); 142 unp_detach(unp); 143 UNP_UNLOCK_ASSERT(); 144 ACCEPT_LOCK(); 145 SOCK_LOCK(so); 146 sotryfree(so); 147 return (0); 148 } 149 150 static int 151 uipc_accept(struct socket *so, struct sockaddr **nam) 152 { 153 struct unpcb *unp; 154 const struct sockaddr *sa; 155 156 /* 157 * Pass back name of connected socket, 158 * if it was bound and we are still connected 159 * (our peer may have closed already!). 160 */ 161 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 162 UNP_LOCK(); 163 unp = sotounpcb(so); 164 if (unp == NULL) { 165 UNP_UNLOCK(); 166 free(*nam, M_SONAME); 167 *nam = NULL; 168 return (EINVAL); 169 } 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 struct unpcb *unp = sotounpcb(so); 183 184 if (unp != NULL) 185 return (EISCONN); 186 return (unp_attach(so)); 187 } 188 189 static int 190 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 191 { 192 struct unpcb *unp; 193 int error; 194 195 UNP_LOCK(); 196 unp = sotounpcb(so); 197 if (unp == NULL) { 198 UNP_UNLOCK(); 199 return (EINVAL); 200 } 201 error = unp_bind(unp, nam, td); 202 UNP_UNLOCK(); 203 return (error); 204 } 205 206 static int 207 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 208 { 209 struct unpcb *unp; 210 int error; 211 212 KASSERT(td == curthread, ("uipc_connect: td != curthread")); 213 214 UNP_LOCK(); 215 unp = sotounpcb(so); 216 if (unp == NULL) { 217 UNP_UNLOCK(); 218 return (EINVAL); 219 } 220 error = unp_connect(so, nam, td); 221 UNP_UNLOCK(); 222 return (error); 223 } 224 225 int 226 uipc_connect2(struct socket *so1, struct socket *so2) 227 { 228 struct unpcb *unp; 229 int error; 230 231 UNP_LOCK(); 232 unp = sotounpcb(so1); 233 if (unp == NULL) { 234 UNP_UNLOCK(); 235 return (EINVAL); 236 } 237 error = unp_connect2(so1, so2, PRU_CONNECT2); 238 UNP_UNLOCK(); 239 return (error); 240 } 241 242 /* control is EOPNOTSUPP */ 243 244 static int 245 uipc_detach(struct socket *so) 246 { 247 struct unpcb *unp; 248 249 UNP_LOCK(); 250 unp = sotounpcb(so); 251 if (unp == NULL) { 252 UNP_UNLOCK(); 253 return (EINVAL); 254 } 255 unp_detach(unp); 256 UNP_UNLOCK_ASSERT(); 257 return (0); 258 } 259 260 static int 261 uipc_disconnect(struct socket *so) 262 { 263 struct unpcb *unp; 264 265 UNP_LOCK(); 266 unp = sotounpcb(so); 267 if (unp == NULL) { 268 UNP_UNLOCK(); 269 return (EINVAL); 270 } 271 unp_disconnect(unp); 272 UNP_UNLOCK(); 273 return (0); 274 } 275 276 static int 277 uipc_listen(struct socket *so, struct thread *td) 278 { 279 struct unpcb *unp; 280 int error; 281 282 UNP_LOCK(); 283 unp = sotounpcb(so); 284 if (unp == NULL || unp->unp_vnode == NULL) { 285 UNP_UNLOCK(); 286 return (EINVAL); 287 } 288 error = unp_listen(so, unp, td); 289 UNP_UNLOCK(); 290 return (error); 291 } 292 293 static int 294 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 295 { 296 struct unpcb *unp; 297 const struct sockaddr *sa; 298 299 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 300 UNP_LOCK(); 301 unp = sotounpcb(so); 302 if (unp == NULL) { 303 UNP_UNLOCK(); 304 free(*nam, M_SONAME); 305 *nam = NULL; 306 return (EINVAL); 307 } 308 if (unp->unp_conn != NULL && unp->unp_conn->unp_addr!= NULL) 309 sa = (struct sockaddr *) unp->unp_conn->unp_addr; 310 else { 311 /* 312 * XXX: It seems that this test always fails even when 313 * connection is established. So, this else clause is 314 * added as workaround to return PF_LOCAL sockaddr. 315 */ 316 sa = &sun_noname; 317 } 318 bcopy(sa, *nam, sa->sa_len); 319 UNP_UNLOCK(); 320 return (0); 321 } 322 323 static int 324 uipc_rcvd(struct socket *so, int flags) 325 { 326 struct unpcb *unp; 327 struct socket *so2; 328 u_long newhiwat; 329 330 UNP_LOCK(); 331 unp = sotounpcb(so); 332 if (unp == NULL) { 333 UNP_UNLOCK(); 334 return (EINVAL); 335 } 336 switch (so->so_type) { 337 case SOCK_DGRAM: 338 panic("uipc_rcvd DGRAM?"); 339 /*NOTREACHED*/ 340 341 case SOCK_STREAM: 342 if (unp->unp_conn == NULL) 343 break; 344 so2 = unp->unp_conn->unp_socket; 345 SOCKBUF_LOCK(&so2->so_snd); 346 SOCKBUF_LOCK(&so->so_rcv); 347 /* 348 * Adjust backpressure on sender 349 * and wakeup any waiting to write. 350 */ 351 so2->so_snd.sb_mbmax += unp->unp_mbcnt - so->so_rcv.sb_mbcnt; 352 unp->unp_mbcnt = so->so_rcv.sb_mbcnt; 353 newhiwat = so2->so_snd.sb_hiwat + unp->unp_cc - 354 so->so_rcv.sb_cc; 355 (void)chgsbsize(so2->so_cred->cr_uidinfo, &so2->so_snd.sb_hiwat, 356 newhiwat, RLIM_INFINITY); 357 unp->unp_cc = so->so_rcv.sb_cc; 358 SOCKBUF_UNLOCK(&so->so_rcv); 359 sowwakeup_locked(so2); 360 break; 361 362 default: 363 panic("uipc_rcvd unknown socktype"); 364 } 365 UNP_UNLOCK(); 366 return (0); 367 } 368 369 /* pru_rcvoob is EOPNOTSUPP */ 370 371 static int 372 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 373 struct mbuf *control, struct thread *td) 374 { 375 int error = 0; 376 struct unpcb *unp; 377 struct socket *so2; 378 u_long newhiwat; 379 380 unp = sotounpcb(so); 381 if (unp == NULL) { 382 error = EINVAL; 383 goto release; 384 } 385 if (flags & PRUS_OOB) { 386 error = EOPNOTSUPP; 387 goto release; 388 } 389 390 if (control != NULL && (error = unp_internalize(&control, td))) 391 goto release; 392 393 UNP_LOCK(); 394 unp = sotounpcb(so); 395 if (unp == NULL) { 396 UNP_UNLOCK(); 397 error = EINVAL; 398 goto dispose_release; 399 } 400 401 switch (so->so_type) { 402 case SOCK_DGRAM: 403 { 404 const struct sockaddr *from; 405 406 if (nam != NULL) { 407 if (unp->unp_conn != NULL) { 408 error = EISCONN; 409 break; 410 } 411 error = unp_connect(so, nam, td); 412 if (error) 413 break; 414 } else { 415 if (unp->unp_conn == NULL) { 416 error = ENOTCONN; 417 break; 418 } 419 } 420 so2 = unp->unp_conn->unp_socket; 421 if (unp->unp_addr != NULL) 422 from = (struct sockaddr *)unp->unp_addr; 423 else 424 from = &sun_noname; 425 if (unp->unp_conn->unp_flags & UNP_WANTCRED) 426 control = unp_addsockcred(td, control); 427 SOCKBUF_LOCK(&so2->so_rcv); 428 if (sbappendaddr_locked(&so2->so_rcv, from, m, control)) { 429 sorwakeup_locked(so2); 430 m = NULL; 431 control = NULL; 432 } else { 433 SOCKBUF_UNLOCK(&so2->so_rcv); 434 error = ENOBUFS; 435 } 436 if (nam != NULL) 437 unp_disconnect(unp); 438 break; 439 } 440 441 case SOCK_STREAM: 442 /* Connect if not connected yet. */ 443 /* 444 * Note: A better implementation would complain 445 * if not equal to the peer's address. 446 */ 447 if ((so->so_state & SS_ISCONNECTED) == 0) { 448 if (nam != NULL) { 449 error = unp_connect(so, nam, td); 450 if (error) 451 break; /* XXX */ 452 } else { 453 error = ENOTCONN; 454 break; 455 } 456 } 457 458 SOCKBUF_LOCK(&so->so_snd); 459 if (so->so_snd.sb_state & SBS_CANTSENDMORE) { 460 SOCKBUF_UNLOCK(&so->so_snd); 461 error = EPIPE; 462 break; 463 } 464 if (unp->unp_conn == NULL) 465 panic("uipc_send connected but no connection?"); 466 so2 = unp->unp_conn->unp_socket; 467 SOCKBUF_LOCK(&so2->so_rcv); 468 if (unp->unp_conn->unp_flags & UNP_WANTCRED) { 469 /* 470 * Credentials are passed only once on 471 * SOCK_STREAM. 472 */ 473 unp->unp_conn->unp_flags &= ~UNP_WANTCRED; 474 control = unp_addsockcred(td, control); 475 } 476 /* 477 * Send to paired receive port, and then reduce 478 * send buffer hiwater marks to maintain backpressure. 479 * Wake up readers. 480 */ 481 if (control != NULL) { 482 if (sbappendcontrol_locked(&so2->so_rcv, m, control)) 483 control = NULL; 484 } else { 485 sbappend_locked(&so2->so_rcv, m); 486 } 487 so->so_snd.sb_mbmax -= 488 so2->so_rcv.sb_mbcnt - unp->unp_conn->unp_mbcnt; 489 unp->unp_conn->unp_mbcnt = so2->so_rcv.sb_mbcnt; 490 newhiwat = so->so_snd.sb_hiwat - 491 (so2->so_rcv.sb_cc - unp->unp_conn->unp_cc); 492 (void)chgsbsize(so->so_cred->cr_uidinfo, &so->so_snd.sb_hiwat, 493 newhiwat, RLIM_INFINITY); 494 SOCKBUF_UNLOCK(&so->so_snd); 495 unp->unp_conn->unp_cc = so2->so_rcv.sb_cc; 496 sorwakeup_locked(so2); 497 m = NULL; 498 break; 499 500 default: 501 panic("uipc_send unknown socktype"); 502 } 503 504 /* 505 * SEND_EOF is equivalent to a SEND followed by 506 * a SHUTDOWN. 507 */ 508 if (flags & PRUS_EOF) { 509 socantsendmore(so); 510 unp_shutdown(unp); 511 } 512 UNP_UNLOCK(); 513 514 dispose_release: 515 if (control != NULL && error != 0) 516 unp_dispose(control); 517 518 release: 519 if (control != NULL) 520 m_freem(control); 521 if (m != NULL) 522 m_freem(m); 523 return (error); 524 } 525 526 static int 527 uipc_sense(struct socket *so, struct stat *sb) 528 { 529 struct unpcb *unp; 530 struct socket *so2; 531 532 UNP_LOCK(); 533 unp = sotounpcb(so); 534 if (unp == NULL) { 535 UNP_UNLOCK(); 536 return (EINVAL); 537 } 538 sb->st_blksize = so->so_snd.sb_hiwat; 539 if (so->so_type == SOCK_STREAM && unp->unp_conn != NULL) { 540 so2 = unp->unp_conn->unp_socket; 541 sb->st_blksize += so2->so_rcv.sb_cc; 542 } 543 sb->st_dev = NODEV; 544 if (unp->unp_ino == 0) 545 unp->unp_ino = (++unp_ino == 0) ? ++unp_ino : unp_ino; 546 sb->st_ino = unp->unp_ino; 547 UNP_UNLOCK(); 548 return (0); 549 } 550 551 static int 552 uipc_shutdown(struct socket *so) 553 { 554 struct unpcb *unp; 555 556 UNP_LOCK(); 557 unp = sotounpcb(so); 558 if (unp == NULL) { 559 UNP_UNLOCK(); 560 return (EINVAL); 561 } 562 socantsendmore(so); 563 unp_shutdown(unp); 564 UNP_UNLOCK(); 565 return (0); 566 } 567 568 static int 569 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 570 { 571 struct unpcb *unp; 572 const struct sockaddr *sa; 573 574 *nam = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 575 UNP_LOCK(); 576 unp = sotounpcb(so); 577 if (unp == NULL) { 578 UNP_UNLOCK(); 579 free(*nam, M_SONAME); 580 *nam = NULL; 581 return (EINVAL); 582 } 583 if (unp->unp_addr != NULL) 584 sa = (struct sockaddr *) unp->unp_addr; 585 else 586 sa = &sun_noname; 587 bcopy(sa, *nam, sa->sa_len); 588 UNP_UNLOCK(); 589 return (0); 590 } 591 592 struct pr_usrreqs uipc_usrreqs = { 593 .pru_abort = uipc_abort, 594 .pru_accept = uipc_accept, 595 .pru_attach = uipc_attach, 596 .pru_bind = uipc_bind, 597 .pru_connect = uipc_connect, 598 .pru_connect2 = uipc_connect2, 599 .pru_detach = uipc_detach, 600 .pru_disconnect = uipc_disconnect, 601 .pru_listen = uipc_listen, 602 .pru_peeraddr = uipc_peeraddr, 603 .pru_rcvd = uipc_rcvd, 604 .pru_send = uipc_send, 605 .pru_sense = uipc_sense, 606 .pru_shutdown = uipc_shutdown, 607 .pru_sockaddr = uipc_sockaddr, 608 .pru_sosend = sosend, 609 .pru_soreceive = soreceive, 610 .pru_sopoll = sopoll, 611 }; 612 613 int 614 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 615 { 616 struct unpcb *unp; 617 struct xucred xu; 618 int error, optval; 619 620 if (sopt->sopt_level != 0) 621 return (EINVAL); 622 623 UNP_LOCK(); 624 unp = sotounpcb(so); 625 if (unp == NULL) { 626 UNP_UNLOCK(); 627 return (EINVAL); 628 } 629 error = 0; 630 631 switch (sopt->sopt_dir) { 632 case SOPT_GET: 633 switch (sopt->sopt_name) { 634 case LOCAL_PEERCRED: 635 if (unp->unp_flags & UNP_HAVEPC) 636 xu = unp->unp_peercred; 637 else { 638 if (so->so_type == SOCK_STREAM) 639 error = ENOTCONN; 640 else 641 error = EINVAL; 642 } 643 if (error == 0) 644 error = sooptcopyout(sopt, &xu, sizeof(xu)); 645 break; 646 case LOCAL_CREDS: 647 optval = unp->unp_flags & UNP_WANTCRED ? 1 : 0; 648 error = sooptcopyout(sopt, &optval, sizeof(optval)); 649 break; 650 case LOCAL_CONNWAIT: 651 optval = unp->unp_flags & UNP_CONNWAIT ? 1 : 0; 652 error = sooptcopyout(sopt, &optval, sizeof(optval)); 653 break; 654 default: 655 error = EOPNOTSUPP; 656 break; 657 } 658 break; 659 case SOPT_SET: 660 switch (sopt->sopt_name) { 661 case LOCAL_CREDS: 662 case LOCAL_CONNWAIT: 663 error = sooptcopyin(sopt, &optval, sizeof(optval), 664 sizeof(optval)); 665 if (error) 666 break; 667 668 #define OPTSET(bit) \ 669 if (optval) \ 670 unp->unp_flags |= bit; \ 671 else \ 672 unp->unp_flags &= ~bit; 673 674 switch (sopt->sopt_name) { 675 case LOCAL_CREDS: 676 OPTSET(UNP_WANTCRED); 677 break; 678 case LOCAL_CONNWAIT: 679 OPTSET(UNP_CONNWAIT); 680 break; 681 default: 682 break; 683 } 684 break; 685 #undef OPTSET 686 default: 687 error = ENOPROTOOPT; 688 break; 689 } 690 break; 691 default: 692 error = EOPNOTSUPP; 693 break; 694 } 695 UNP_UNLOCK(); 696 return (error); 697 } 698 699 /* 700 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 701 * for stream sockets, although the total for sender and receiver is 702 * actually only PIPSIZ. 703 * Datagram sockets really use the sendspace as the maximum datagram size, 704 * and don't really want to reserve the sendspace. Their recvspace should 705 * be large enough for at least one max-size datagram plus address. 706 */ 707 #ifndef PIPSIZ 708 #define PIPSIZ 8192 709 #endif 710 static u_long unpst_sendspace = PIPSIZ; 711 static u_long unpst_recvspace = PIPSIZ; 712 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 713 static u_long unpdg_recvspace = 4*1024; 714 715 static int unp_rights; /* file descriptors in flight */ 716 717 SYSCTL_DECL(_net_local_stream); 718 SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 719 &unpst_sendspace, 0, ""); 720 SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 721 &unpst_recvspace, 0, ""); 722 SYSCTL_DECL(_net_local_dgram); 723 SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 724 &unpdg_sendspace, 0, ""); 725 SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 726 &unpdg_recvspace, 0, ""); 727 SYSCTL_DECL(_net_local); 728 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, ""); 729 730 static int 731 unp_attach(struct socket *so) 732 { 733 struct unpcb *unp; 734 int error; 735 736 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 737 switch (so->so_type) { 738 739 case SOCK_STREAM: 740 error = soreserve(so, unpst_sendspace, unpst_recvspace); 741 break; 742 743 case SOCK_DGRAM: 744 error = soreserve(so, unpdg_sendspace, unpdg_recvspace); 745 break; 746 747 default: 748 panic("unp_attach"); 749 } 750 if (error) 751 return (error); 752 } 753 unp = uma_zalloc(unp_zone, M_WAITOK | M_ZERO); 754 if (unp == NULL) 755 return (ENOBUFS); 756 LIST_INIT(&unp->unp_refs); 757 unp->unp_socket = so; 758 so->so_pcb = unp; 759 760 UNP_LOCK(); 761 unp->unp_gencnt = ++unp_gencnt; 762 unp_count++; 763 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead 764 : &unp_shead, unp, unp_link); 765 UNP_UNLOCK(); 766 767 return (0); 768 } 769 770 static void 771 unp_detach(struct unpcb *unp) 772 { 773 struct vnode *vp; 774 775 UNP_LOCK_ASSERT(); 776 777 LIST_REMOVE(unp, unp_link); 778 unp->unp_gencnt = ++unp_gencnt; 779 --unp_count; 780 if ((vp = unp->unp_vnode) != NULL) { 781 /* 782 * XXXRW: should v_socket be frobbed only while holding 783 * Giant? 784 */ 785 unp->unp_vnode->v_socket = NULL; 786 unp->unp_vnode = NULL; 787 } 788 if (unp->unp_conn != NULL) 789 unp_disconnect(unp); 790 while (!LIST_EMPTY(&unp->unp_refs)) { 791 struct unpcb *ref = LIST_FIRST(&unp->unp_refs); 792 unp_drop(ref, ECONNRESET); 793 } 794 soisdisconnected(unp->unp_socket); 795 unp->unp_socket->so_pcb = NULL; 796 if (unp_rights) { 797 /* 798 * Normally the receive buffer is flushed later, 799 * in sofree, but if our receive buffer holds references 800 * to descriptors that are now garbage, we will dispose 801 * of those descriptor references after the garbage collector 802 * gets them (resulting in a "panic: closef: count < 0"). 803 */ 804 sorflush(unp->unp_socket); 805 unp_gc(); /* Will unlock UNP. */ 806 } else 807 UNP_UNLOCK(); 808 UNP_UNLOCK_ASSERT(); 809 if (unp->unp_addr != NULL) 810 FREE(unp->unp_addr, M_SONAME); 811 uma_zfree(unp_zone, unp); 812 if (vp) { 813 mtx_lock(&Giant); 814 vrele(vp); 815 mtx_unlock(&Giant); 816 } 817 } 818 819 static int 820 unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td) 821 { 822 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 823 struct vnode *vp; 824 struct mount *mp; 825 struct vattr vattr; 826 int error, namelen; 827 struct nameidata nd; 828 char *buf; 829 830 UNP_LOCK_ASSERT(); 831 832 /* 833 * XXXRW: This test-and-set of unp_vnode is non-atomic; the 834 * unlocked read here is fine, but the value of unp_vnode needs 835 * to be tested again after we do all the lookups to see if the 836 * pcb is still unbound? 837 */ 838 if (unp->unp_vnode != NULL) 839 return (EINVAL); 840 841 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 842 if (namelen <= 0) 843 return (EINVAL); 844 845 UNP_UNLOCK(); 846 847 buf = malloc(namelen + 1, M_TEMP, M_WAITOK); 848 strlcpy(buf, soun->sun_path, namelen + 1); 849 850 mtx_lock(&Giant); 851 restart: 852 mtx_assert(&Giant, MA_OWNED); 853 NDINIT(&nd, CREATE, NOFOLLOW | LOCKPARENT | SAVENAME, UIO_SYSSPACE, 854 buf, td); 855 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 856 error = namei(&nd); 857 if (error) 858 goto done; 859 vp = nd.ni_vp; 860 if (vp != NULL || vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) { 861 NDFREE(&nd, NDF_ONLY_PNBUF); 862 if (nd.ni_dvp == vp) 863 vrele(nd.ni_dvp); 864 else 865 vput(nd.ni_dvp); 866 if (vp != NULL) { 867 vrele(vp); 868 error = EADDRINUSE; 869 goto done; 870 } 871 error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH); 872 if (error) 873 goto done; 874 goto restart; 875 } 876 VATTR_NULL(&vattr); 877 vattr.va_type = VSOCK; 878 vattr.va_mode = (ACCESSPERMS & ~td->td_proc->p_fd->fd_cmask); 879 #ifdef MAC 880 error = mac_check_vnode_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd, 881 &vattr); 882 #endif 883 if (error == 0) { 884 VOP_LEASE(nd.ni_dvp, td, td->td_ucred, LEASE_WRITE); 885 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 886 } 887 NDFREE(&nd, NDF_ONLY_PNBUF); 888 vput(nd.ni_dvp); 889 if (error) { 890 vn_finished_write(mp); 891 goto done; 892 } 893 vp = nd.ni_vp; 894 ASSERT_VOP_LOCKED(vp, "unp_bind"); 895 soun = (struct sockaddr_un *)sodupsockaddr(nam, M_WAITOK); 896 UNP_LOCK(); 897 vp->v_socket = unp->unp_socket; 898 unp->unp_vnode = vp; 899 unp->unp_addr = soun; 900 UNP_UNLOCK(); 901 VOP_UNLOCK(vp, 0, td); 902 vn_finished_write(mp); 903 done: 904 mtx_unlock(&Giant); 905 free(buf, M_TEMP); 906 UNP_LOCK(); 907 return (error); 908 } 909 910 static int 911 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 912 { 913 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 914 struct vnode *vp; 915 struct socket *so2, *so3; 916 struct unpcb *unp, *unp2, *unp3; 917 int error, len; 918 struct nameidata nd; 919 char buf[SOCK_MAXADDRLEN]; 920 struct sockaddr *sa; 921 922 UNP_LOCK_ASSERT(); 923 unp = sotounpcb(so); 924 925 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 926 if (len <= 0) 927 return (EINVAL); 928 strlcpy(buf, soun->sun_path, len + 1); 929 UNP_UNLOCK(); 930 sa = malloc(sizeof(struct sockaddr_un), M_SONAME, M_WAITOK); 931 mtx_lock(&Giant); 932 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, buf, td); 933 error = namei(&nd); 934 if (error) 935 vp = NULL; 936 else 937 vp = nd.ni_vp; 938 ASSERT_VOP_LOCKED(vp, "unp_connect"); 939 NDFREE(&nd, NDF_ONLY_PNBUF); 940 if (error) 941 goto bad; 942 943 if (vp->v_type != VSOCK) { 944 error = ENOTSOCK; 945 goto bad; 946 } 947 error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td); 948 if (error) 949 goto bad; 950 mtx_unlock(&Giant); 951 UNP_LOCK(); 952 unp = sotounpcb(so); 953 if (unp == NULL) { 954 error = EINVAL; 955 goto bad2; 956 } 957 so2 = vp->v_socket; 958 if (so2 == NULL) { 959 error = ECONNREFUSED; 960 goto bad2; 961 } 962 if (so->so_type != so2->so_type) { 963 error = EPROTOTYPE; 964 goto bad2; 965 } 966 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 967 if (so2->so_options & SO_ACCEPTCONN) { 968 /* 969 * NB: drop locks here so unp_attach is entered 970 * w/o locks; this avoids a recursive lock 971 * of the head and holding sleep locks across 972 * a (potentially) blocking malloc. 973 */ 974 UNP_UNLOCK(); 975 so3 = sonewconn(so2, 0); 976 UNP_LOCK(); 977 } else 978 so3 = NULL; 979 if (so3 == NULL) { 980 error = ECONNREFUSED; 981 goto bad2; 982 } 983 unp = sotounpcb(so); 984 unp2 = sotounpcb(so2); 985 unp3 = sotounpcb(so3); 986 if (unp2->unp_addr != NULL) { 987 bcopy(unp2->unp_addr, sa, unp2->unp_addr->sun_len); 988 unp3->unp_addr = (struct sockaddr_un *) sa; 989 sa = NULL; 990 } 991 /* 992 * unp_peercred management: 993 * 994 * The connecter's (client's) credentials are copied 995 * from its process structure at the time of connect() 996 * (which is now). 997 */ 998 cru2x(td->td_ucred, &unp3->unp_peercred); 999 unp3->unp_flags |= UNP_HAVEPC; 1000 /* 1001 * The receiver's (server's) credentials are copied 1002 * from the unp_peercred member of socket on which the 1003 * former called listen(); unp_listen() cached that 1004 * process's credentials at that time so we can use 1005 * them now. 1006 */ 1007 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1008 ("unp_connect: listener without cached peercred")); 1009 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1010 sizeof(unp->unp_peercred)); 1011 unp->unp_flags |= UNP_HAVEPC; 1012 #ifdef MAC 1013 SOCK_LOCK(so); 1014 mac_set_socket_peer_from_socket(so, so3); 1015 mac_set_socket_peer_from_socket(so3, so); 1016 SOCK_UNLOCK(so); 1017 #endif 1018 1019 so2 = so3; 1020 } 1021 error = unp_connect2(so, so2, PRU_CONNECT); 1022 bad2: 1023 UNP_UNLOCK(); 1024 mtx_lock(&Giant); 1025 bad: 1026 mtx_assert(&Giant, MA_OWNED); 1027 if (vp != NULL) 1028 vput(vp); 1029 mtx_unlock(&Giant); 1030 free(sa, M_SONAME); 1031 UNP_LOCK(); 1032 return (error); 1033 } 1034 1035 static int 1036 unp_connect2(struct socket *so, struct socket *so2, int req) 1037 { 1038 struct unpcb *unp = sotounpcb(so); 1039 struct unpcb *unp2; 1040 1041 UNP_LOCK_ASSERT(); 1042 1043 if (so2->so_type != so->so_type) 1044 return (EPROTOTYPE); 1045 unp2 = sotounpcb(so2); 1046 unp->unp_conn = unp2; 1047 switch (so->so_type) { 1048 1049 case SOCK_DGRAM: 1050 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1051 soisconnected(so); 1052 break; 1053 1054 case SOCK_STREAM: 1055 unp2->unp_conn = unp; 1056 if (req == PRU_CONNECT && 1057 ((unp->unp_flags | unp2->unp_flags) & UNP_CONNWAIT)) 1058 soisconnecting(so); 1059 else 1060 soisconnected(so); 1061 soisconnected(so2); 1062 break; 1063 1064 default: 1065 panic("unp_connect2"); 1066 } 1067 return (0); 1068 } 1069 1070 static void 1071 unp_disconnect(struct unpcb *unp) 1072 { 1073 struct unpcb *unp2 = unp->unp_conn; 1074 struct socket *so; 1075 1076 UNP_LOCK_ASSERT(); 1077 1078 if (unp2 == NULL) 1079 return; 1080 unp->unp_conn = NULL; 1081 switch (unp->unp_socket->so_type) { 1082 1083 case SOCK_DGRAM: 1084 LIST_REMOVE(unp, unp_reflink); 1085 so = unp->unp_socket; 1086 SOCK_LOCK(so); 1087 so->so_state &= ~SS_ISCONNECTED; 1088 SOCK_UNLOCK(so); 1089 break; 1090 1091 case SOCK_STREAM: 1092 soisdisconnected(unp->unp_socket); 1093 unp2->unp_conn = NULL; 1094 soisdisconnected(unp2->unp_socket); 1095 break; 1096 } 1097 } 1098 1099 #ifdef notdef 1100 void 1101 unp_abort(struct unpcb *unp) 1102 { 1103 1104 unp_detach(unp); 1105 UNP_UNLOCK_ASSERT(); 1106 } 1107 #endif 1108 1109 /* 1110 * unp_pcblist() assumes that UNIX domain socket memory is never reclaimed 1111 * by the zone (UMA_ZONE_NOFREE), and as such potentially stale pointers 1112 * are safe to reference. It first scans the list of struct unpcb's to 1113 * generate a pointer list, then it rescans its list one entry at a time to 1114 * externalize and copyout. It checks the generation number to see if a 1115 * struct unpcb has been reused, and will skip it if so. 1116 */ 1117 static int 1118 unp_pcblist(SYSCTL_HANDLER_ARGS) 1119 { 1120 int error, i, n; 1121 struct unpcb *unp, **unp_list; 1122 unp_gen_t gencnt; 1123 struct xunpgen *xug; 1124 struct unp_head *head; 1125 struct xunpcb *xu; 1126 1127 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 1128 1129 /* 1130 * The process of preparing the PCB list is too time-consuming and 1131 * resource-intensive to repeat twice on every request. 1132 */ 1133 if (req->oldptr == NULL) { 1134 n = unp_count; 1135 req->oldidx = 2 * (sizeof *xug) 1136 + (n + n/8) * sizeof(struct xunpcb); 1137 return (0); 1138 } 1139 1140 if (req->newptr != NULL) 1141 return (EPERM); 1142 1143 /* 1144 * OK, now we're committed to doing something. 1145 */ 1146 xug = malloc(sizeof(*xug), M_TEMP, M_WAITOK); 1147 UNP_LOCK(); 1148 gencnt = unp_gencnt; 1149 n = unp_count; 1150 UNP_UNLOCK(); 1151 1152 xug->xug_len = sizeof *xug; 1153 xug->xug_count = n; 1154 xug->xug_gen = gencnt; 1155 xug->xug_sogen = so_gencnt; 1156 error = SYSCTL_OUT(req, xug, sizeof *xug); 1157 if (error) { 1158 free(xug, M_TEMP); 1159 return (error); 1160 } 1161 1162 unp_list = malloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1163 1164 UNP_LOCK(); 1165 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1166 unp = LIST_NEXT(unp, unp_link)) { 1167 if (unp->unp_gencnt <= gencnt) { 1168 if (cr_cansee(req->td->td_ucred, 1169 unp->unp_socket->so_cred)) 1170 continue; 1171 unp_list[i++] = unp; 1172 } 1173 } 1174 UNP_UNLOCK(); 1175 n = i; /* in case we lost some during malloc */ 1176 1177 error = 0; 1178 xu = malloc(sizeof(*xu), M_TEMP, M_WAITOK | M_ZERO); 1179 for (i = 0; i < n; i++) { 1180 unp = unp_list[i]; 1181 if (unp->unp_gencnt <= gencnt) { 1182 xu->xu_len = sizeof *xu; 1183 xu->xu_unpp = unp; 1184 /* 1185 * XXX - need more locking here to protect against 1186 * connect/disconnect races for SMP. 1187 */ 1188 if (unp->unp_addr != NULL) 1189 bcopy(unp->unp_addr, &xu->xu_addr, 1190 unp->unp_addr->sun_len); 1191 if (unp->unp_conn != NULL && 1192 unp->unp_conn->unp_addr != NULL) 1193 bcopy(unp->unp_conn->unp_addr, 1194 &xu->xu_caddr, 1195 unp->unp_conn->unp_addr->sun_len); 1196 bcopy(unp, &xu->xu_unp, sizeof *unp); 1197 sotoxsocket(unp->unp_socket, &xu->xu_socket); 1198 error = SYSCTL_OUT(req, xu, sizeof *xu); 1199 } 1200 } 1201 free(xu, M_TEMP); 1202 if (!error) { 1203 /* 1204 * Give the user an updated idea of our state. 1205 * If the generation differs from what we told 1206 * her before, she knows that something happened 1207 * while we were processing this request, and it 1208 * might be necessary to retry. 1209 */ 1210 xug->xug_gen = unp_gencnt; 1211 xug->xug_sogen = so_gencnt; 1212 xug->xug_count = unp_count; 1213 error = SYSCTL_OUT(req, xug, sizeof *xug); 1214 } 1215 free(unp_list, M_TEMP); 1216 free(xug, M_TEMP); 1217 return (error); 1218 } 1219 1220 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 1221 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1222 "List of active local datagram sockets"); 1223 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 1224 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1225 "List of active local stream sockets"); 1226 1227 static void 1228 unp_shutdown(struct unpcb *unp) 1229 { 1230 struct socket *so; 1231 1232 UNP_LOCK_ASSERT(); 1233 1234 if (unp->unp_socket->so_type == SOCK_STREAM && unp->unp_conn && 1235 (so = unp->unp_conn->unp_socket)) 1236 socantrcvmore(so); 1237 } 1238 1239 static void 1240 unp_drop(struct unpcb *unp, int errno) 1241 { 1242 struct socket *so = unp->unp_socket; 1243 1244 UNP_LOCK_ASSERT(); 1245 1246 so->so_error = errno; 1247 unp_disconnect(unp); 1248 } 1249 1250 #ifdef notdef 1251 void 1252 unp_drain(void) 1253 { 1254 1255 } 1256 #endif 1257 1258 static void 1259 unp_freerights(struct file **rp, int fdcount) 1260 { 1261 int i; 1262 struct file *fp; 1263 1264 for (i = 0; i < fdcount; i++) { 1265 fp = *rp; 1266 /* 1267 * zero the pointer before calling 1268 * unp_discard since it may end up 1269 * in unp_gc().. 1270 */ 1271 *rp++ = 0; 1272 unp_discard(fp); 1273 } 1274 } 1275 1276 int 1277 unp_externalize(struct mbuf *control, struct mbuf **controlp) 1278 { 1279 struct thread *td = curthread; /* XXX */ 1280 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1281 int i; 1282 int *fdp; 1283 struct file **rp; 1284 struct file *fp; 1285 void *data; 1286 socklen_t clen = control->m_len, datalen; 1287 int error, newfds; 1288 int f; 1289 u_int newlen; 1290 1291 UNP_UNLOCK_ASSERT(); 1292 1293 error = 0; 1294 if (controlp != NULL) /* controlp == NULL => free control messages */ 1295 *controlp = NULL; 1296 1297 while (cm != NULL) { 1298 if (sizeof(*cm) > clen || cm->cmsg_len > clen) { 1299 error = EINVAL; 1300 break; 1301 } 1302 1303 data = CMSG_DATA(cm); 1304 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1305 1306 if (cm->cmsg_level == SOL_SOCKET 1307 && cm->cmsg_type == SCM_RIGHTS) { 1308 newfds = datalen / sizeof(struct file *); 1309 rp = data; 1310 1311 /* If we're not outputting the descriptors free them. */ 1312 if (error || controlp == NULL) { 1313 unp_freerights(rp, newfds); 1314 goto next; 1315 } 1316 FILEDESC_LOCK(td->td_proc->p_fd); 1317 /* if the new FD's will not fit free them. */ 1318 if (!fdavail(td, newfds)) { 1319 FILEDESC_UNLOCK(td->td_proc->p_fd); 1320 error = EMSGSIZE; 1321 unp_freerights(rp, newfds); 1322 goto next; 1323 } 1324 /* 1325 * now change each pointer to an fd in the global 1326 * table to an integer that is the index to the 1327 * local fd table entry that we set up to point 1328 * to the global one we are transferring. 1329 */ 1330 newlen = newfds * sizeof(int); 1331 *controlp = sbcreatecontrol(NULL, newlen, 1332 SCM_RIGHTS, SOL_SOCKET); 1333 if (*controlp == NULL) { 1334 FILEDESC_UNLOCK(td->td_proc->p_fd); 1335 error = E2BIG; 1336 unp_freerights(rp, newfds); 1337 goto next; 1338 } 1339 1340 fdp = (int *) 1341 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1342 for (i = 0; i < newfds; i++) { 1343 if (fdalloc(td, 0, &f)) 1344 panic("unp_externalize fdalloc failed"); 1345 fp = *rp++; 1346 td->td_proc->p_fd->fd_ofiles[f] = fp; 1347 FILE_LOCK(fp); 1348 fp->f_msgcount--; 1349 FILE_UNLOCK(fp); 1350 unp_rights--; 1351 *fdp++ = f; 1352 } 1353 FILEDESC_UNLOCK(td->td_proc->p_fd); 1354 } else { /* We can just copy anything else across */ 1355 if (error || controlp == NULL) 1356 goto next; 1357 *controlp = sbcreatecontrol(NULL, datalen, 1358 cm->cmsg_type, cm->cmsg_level); 1359 if (*controlp == NULL) { 1360 error = ENOBUFS; 1361 goto next; 1362 } 1363 bcopy(data, 1364 CMSG_DATA(mtod(*controlp, struct cmsghdr *)), 1365 datalen); 1366 } 1367 1368 controlp = &(*controlp)->m_next; 1369 1370 next: 1371 if (CMSG_SPACE(datalen) < clen) { 1372 clen -= CMSG_SPACE(datalen); 1373 cm = (struct cmsghdr *) 1374 ((caddr_t)cm + CMSG_SPACE(datalen)); 1375 } else { 1376 clen = 0; 1377 cm = NULL; 1378 } 1379 } 1380 1381 m_freem(control); 1382 1383 return (error); 1384 } 1385 1386 void 1387 unp_init(void) 1388 { 1389 unp_zone = uma_zcreate("unpcb", sizeof(struct unpcb), NULL, NULL, 1390 NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 1391 if (unp_zone == NULL) 1392 panic("unp_init"); 1393 uma_zone_set_max(unp_zone, nmbclusters); 1394 LIST_INIT(&unp_dhead); 1395 LIST_INIT(&unp_shead); 1396 1397 UNP_LOCK_INIT(); 1398 } 1399 1400 static int 1401 unp_internalize(struct mbuf **controlp, struct thread *td) 1402 { 1403 struct mbuf *control = *controlp; 1404 struct proc *p = td->td_proc; 1405 struct filedesc *fdescp = p->p_fd; 1406 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1407 struct cmsgcred *cmcred; 1408 struct file **rp; 1409 struct file *fp; 1410 struct timeval *tv; 1411 int i, fd, *fdp; 1412 void *data; 1413 socklen_t clen = control->m_len, datalen; 1414 int error, oldfds; 1415 u_int newlen; 1416 1417 UNP_UNLOCK_ASSERT(); 1418 1419 error = 0; 1420 *controlp = NULL; 1421 1422 while (cm != NULL) { 1423 if (sizeof(*cm) > clen || cm->cmsg_level != SOL_SOCKET 1424 || cm->cmsg_len > clen) { 1425 error = EINVAL; 1426 goto out; 1427 } 1428 1429 data = CMSG_DATA(cm); 1430 datalen = (caddr_t)cm + cm->cmsg_len - (caddr_t)data; 1431 1432 switch (cm->cmsg_type) { 1433 /* 1434 * Fill in credential information. 1435 */ 1436 case SCM_CREDS: 1437 *controlp = sbcreatecontrol(NULL, sizeof(*cmcred), 1438 SCM_CREDS, SOL_SOCKET); 1439 if (*controlp == NULL) { 1440 error = ENOBUFS; 1441 goto out; 1442 } 1443 1444 cmcred = (struct cmsgcred *) 1445 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1446 cmcred->cmcred_pid = p->p_pid; 1447 cmcred->cmcred_uid = td->td_ucred->cr_ruid; 1448 cmcred->cmcred_gid = td->td_ucred->cr_rgid; 1449 cmcred->cmcred_euid = td->td_ucred->cr_uid; 1450 cmcred->cmcred_ngroups = MIN(td->td_ucred->cr_ngroups, 1451 CMGROUP_MAX); 1452 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1453 cmcred->cmcred_groups[i] = 1454 td->td_ucred->cr_groups[i]; 1455 break; 1456 1457 case SCM_RIGHTS: 1458 oldfds = datalen / sizeof (int); 1459 /* 1460 * check that all the FDs passed in refer to legal files 1461 * If not, reject the entire operation. 1462 */ 1463 fdp = data; 1464 FILEDESC_LOCK(fdescp); 1465 for (i = 0; i < oldfds; i++) { 1466 fd = *fdp++; 1467 if ((unsigned)fd >= fdescp->fd_nfiles || 1468 fdescp->fd_ofiles[fd] == NULL) { 1469 FILEDESC_UNLOCK(fdescp); 1470 error = EBADF; 1471 goto out; 1472 } 1473 fp = fdescp->fd_ofiles[fd]; 1474 if (!(fp->f_ops->fo_flags & DFLAG_PASSABLE)) { 1475 FILEDESC_UNLOCK(fdescp); 1476 error = EOPNOTSUPP; 1477 goto out; 1478 } 1479 1480 } 1481 /* 1482 * Now replace the integer FDs with pointers to 1483 * the associated global file table entry.. 1484 */ 1485 newlen = oldfds * sizeof(struct file *); 1486 *controlp = sbcreatecontrol(NULL, newlen, 1487 SCM_RIGHTS, SOL_SOCKET); 1488 if (*controlp == NULL) { 1489 FILEDESC_UNLOCK(fdescp); 1490 error = E2BIG; 1491 goto out; 1492 } 1493 1494 fdp = data; 1495 rp = (struct file **) 1496 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1497 for (i = 0; i < oldfds; i++) { 1498 fp = fdescp->fd_ofiles[*fdp++]; 1499 *rp++ = fp; 1500 FILE_LOCK(fp); 1501 fp->f_count++; 1502 fp->f_msgcount++; 1503 FILE_UNLOCK(fp); 1504 unp_rights++; 1505 } 1506 FILEDESC_UNLOCK(fdescp); 1507 break; 1508 1509 case SCM_TIMESTAMP: 1510 *controlp = sbcreatecontrol(NULL, sizeof(*tv), 1511 SCM_TIMESTAMP, SOL_SOCKET); 1512 if (*controlp == NULL) { 1513 error = ENOBUFS; 1514 goto out; 1515 } 1516 tv = (struct timeval *) 1517 CMSG_DATA(mtod(*controlp, struct cmsghdr *)); 1518 microtime(tv); 1519 break; 1520 1521 default: 1522 error = EINVAL; 1523 goto out; 1524 } 1525 1526 controlp = &(*controlp)->m_next; 1527 1528 if (CMSG_SPACE(datalen) < clen) { 1529 clen -= CMSG_SPACE(datalen); 1530 cm = (struct cmsghdr *) 1531 ((caddr_t)cm + CMSG_SPACE(datalen)); 1532 } else { 1533 clen = 0; 1534 cm = NULL; 1535 } 1536 } 1537 1538 out: 1539 m_freem(control); 1540 1541 return (error); 1542 } 1543 1544 struct mbuf * 1545 unp_addsockcred(struct thread *td, struct mbuf *control) 1546 { 1547 struct mbuf *m, *n; 1548 struct sockcred *sc; 1549 int ngroups; 1550 int i; 1551 1552 ngroups = MIN(td->td_ucred->cr_ngroups, CMGROUP_MAX); 1553 1554 m = sbcreatecontrol(NULL, SOCKCREDSIZE(ngroups), SCM_CREDS, SOL_SOCKET); 1555 if (m == NULL) 1556 return (control); 1557 m->m_next = NULL; 1558 1559 sc = (struct sockcred *) CMSG_DATA(mtod(m, struct cmsghdr *)); 1560 sc->sc_uid = td->td_ucred->cr_ruid; 1561 sc->sc_euid = td->td_ucred->cr_uid; 1562 sc->sc_gid = td->td_ucred->cr_rgid; 1563 sc->sc_egid = td->td_ucred->cr_gid; 1564 sc->sc_ngroups = ngroups; 1565 for (i = 0; i < sc->sc_ngroups; i++) 1566 sc->sc_groups[i] = td->td_ucred->cr_groups[i]; 1567 1568 /* 1569 * If a control message already exists, append us to the end. 1570 */ 1571 if (control != NULL) { 1572 for (n = control; n->m_next != NULL; n = n->m_next) 1573 ; 1574 n->m_next = m; 1575 } else 1576 control = m; 1577 1578 return (control); 1579 } 1580 1581 /* 1582 * unp_defer is thread-local during garbage collection, and does not require 1583 * explicit synchronization. unp_gcing prevents other threads from entering 1584 * garbage collection, and perhaps should be an sx lock instead. 1585 */ 1586 static int unp_defer, unp_gcing; 1587 1588 static void 1589 unp_gc(void) 1590 { 1591 struct file *fp, *nextfp; 1592 struct socket *so; 1593 struct file **extra_ref, **fpp; 1594 int nunref, i; 1595 int nfiles_snap; 1596 int nfiles_slack = 20; 1597 1598 UNP_LOCK_ASSERT(); 1599 1600 if (unp_gcing) { 1601 UNP_UNLOCK(); 1602 return; 1603 } 1604 unp_gcing = 1; 1605 unp_defer = 0; 1606 UNP_UNLOCK(); 1607 /* 1608 * before going through all this, set all FDs to 1609 * be NOT defered and NOT externally accessible 1610 */ 1611 sx_slock(&filelist_lock); 1612 LIST_FOREACH(fp, &filehead, f_list) 1613 fp->f_gcflag &= ~(FMARK|FDEFER); 1614 do { 1615 LIST_FOREACH(fp, &filehead, f_list) { 1616 FILE_LOCK(fp); 1617 /* 1618 * If the file is not open, skip it 1619 */ 1620 if (fp->f_count == 0) { 1621 FILE_UNLOCK(fp); 1622 continue; 1623 } 1624 /* 1625 * If we already marked it as 'defer' in a 1626 * previous pass, then try process it this time 1627 * and un-mark it 1628 */ 1629 if (fp->f_gcflag & FDEFER) { 1630 fp->f_gcflag &= ~FDEFER; 1631 unp_defer--; 1632 } else { 1633 /* 1634 * if it's not defered, then check if it's 1635 * already marked.. if so skip it 1636 */ 1637 if (fp->f_gcflag & FMARK) { 1638 FILE_UNLOCK(fp); 1639 continue; 1640 } 1641 /* 1642 * If all references are from messages 1643 * in transit, then skip it. it's not 1644 * externally accessible. 1645 */ 1646 if (fp->f_count == fp->f_msgcount) { 1647 FILE_UNLOCK(fp); 1648 continue; 1649 } 1650 /* 1651 * If it got this far then it must be 1652 * externally accessible. 1653 */ 1654 fp->f_gcflag |= FMARK; 1655 } 1656 /* 1657 * either it was defered, or it is externally 1658 * accessible and not already marked so. 1659 * Now check if it is possibly one of OUR sockets. 1660 */ 1661 if (fp->f_type != DTYPE_SOCKET || 1662 (so = fp->f_data) == NULL) { 1663 FILE_UNLOCK(fp); 1664 continue; 1665 } 1666 FILE_UNLOCK(fp); 1667 if (so->so_proto->pr_domain != &localdomain || 1668 (so->so_proto->pr_flags&PR_RIGHTS) == 0) 1669 continue; 1670 #ifdef notdef 1671 if (so->so_rcv.sb_flags & SB_LOCK) { 1672 /* 1673 * This is problematical; it's not clear 1674 * we need to wait for the sockbuf to be 1675 * unlocked (on a uniprocessor, at least), 1676 * and it's also not clear what to do 1677 * if sbwait returns an error due to receipt 1678 * of a signal. If sbwait does return 1679 * an error, we'll go into an infinite 1680 * loop. Delete all of this for now. 1681 */ 1682 (void) sbwait(&so->so_rcv); 1683 goto restart; 1684 } 1685 #endif 1686 /* 1687 * So, Ok, it's one of our sockets and it IS externally 1688 * accessible (or was defered). Now we look 1689 * to see if we hold any file descriptors in its 1690 * message buffers. Follow those links and mark them 1691 * as accessible too. 1692 */ 1693 SOCKBUF_LOCK(&so->so_rcv); 1694 unp_scan(so->so_rcv.sb_mb, unp_mark); 1695 SOCKBUF_UNLOCK(&so->so_rcv); 1696 } 1697 } while (unp_defer); 1698 sx_sunlock(&filelist_lock); 1699 /* 1700 * We grab an extra reference to each of the file table entries 1701 * that are not otherwise accessible and then free the rights 1702 * that are stored in messages on them. 1703 * 1704 * The bug in the orginal code is a little tricky, so I'll describe 1705 * what's wrong with it here. 1706 * 1707 * It is incorrect to simply unp_discard each entry for f_msgcount 1708 * times -- consider the case of sockets A and B that contain 1709 * references to each other. On a last close of some other socket, 1710 * we trigger a gc since the number of outstanding rights (unp_rights) 1711 * is non-zero. If during the sweep phase the gc code un_discards, 1712 * we end up doing a (full) closef on the descriptor. A closef on A 1713 * results in the following chain. Closef calls soo_close, which 1714 * calls soclose. Soclose calls first (through the switch 1715 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply 1716 * returns because the previous instance had set unp_gcing, and 1717 * we return all the way back to soclose, which marks the socket 1718 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush 1719 * to free up the rights that are queued in messages on the socket A, 1720 * i.e., the reference on B. The sorflush calls via the dom_dispose 1721 * switch unp_dispose, which unp_scans with unp_discard. This second 1722 * instance of unp_discard just calls closef on B. 1723 * 1724 * Well, a similar chain occurs on B, resulting in a sorflush on B, 1725 * which results in another closef on A. Unfortunately, A is already 1726 * being closed, and the descriptor has already been marked with 1727 * SS_NOFDREF, and soclose panics at this point. 1728 * 1729 * Here, we first take an extra reference to each inaccessible 1730 * descriptor. Then, we call sorflush ourself, since we know 1731 * it is a Unix domain socket anyhow. After we destroy all the 1732 * rights carried in messages, we do a last closef to get rid 1733 * of our extra reference. This is the last close, and the 1734 * unp_detach etc will shut down the socket. 1735 * 1736 * 91/09/19, bsy@cs.cmu.edu 1737 */ 1738 again: 1739 nfiles_snap = openfiles + nfiles_slack; /* some slack */ 1740 extra_ref = malloc(nfiles_snap * sizeof(struct file *), M_TEMP, 1741 M_WAITOK); 1742 sx_slock(&filelist_lock); 1743 if (nfiles_snap < openfiles) { 1744 sx_sunlock(&filelist_lock); 1745 free(extra_ref, M_TEMP); 1746 nfiles_slack += 20; 1747 goto again; 1748 } 1749 for (nunref = 0, fp = LIST_FIRST(&filehead), fpp = extra_ref; 1750 fp != NULL; fp = nextfp) { 1751 nextfp = LIST_NEXT(fp, f_list); 1752 FILE_LOCK(fp); 1753 /* 1754 * If it's not open, skip it 1755 */ 1756 if (fp->f_count == 0) { 1757 FILE_UNLOCK(fp); 1758 continue; 1759 } 1760 /* 1761 * If all refs are from msgs, and it's not marked accessible 1762 * then it must be referenced from some unreachable cycle 1763 * of (shut-down) FDs, so include it in our 1764 * list of FDs to remove 1765 */ 1766 if (fp->f_count == fp->f_msgcount && !(fp->f_gcflag & FMARK)) { 1767 *fpp++ = fp; 1768 nunref++; 1769 fp->f_count++; 1770 } 1771 FILE_UNLOCK(fp); 1772 } 1773 sx_sunlock(&filelist_lock); 1774 /* 1775 * for each FD on our hit list, do the following two things 1776 */ 1777 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) { 1778 struct file *tfp = *fpp; 1779 FILE_LOCK(tfp); 1780 if (tfp->f_type == DTYPE_SOCKET && 1781 tfp->f_data != NULL) { 1782 FILE_UNLOCK(tfp); 1783 sorflush(tfp->f_data); 1784 } else { 1785 FILE_UNLOCK(tfp); 1786 } 1787 } 1788 for (i = nunref, fpp = extra_ref; --i >= 0; ++fpp) 1789 closef(*fpp, (struct thread *) NULL); 1790 free(extra_ref, M_TEMP); 1791 unp_gcing = 0; 1792 1793 UNP_UNLOCK_ASSERT(); 1794 } 1795 1796 void 1797 unp_dispose(struct mbuf *m) 1798 { 1799 1800 if (m) 1801 unp_scan(m, unp_discard); 1802 } 1803 1804 static int 1805 unp_listen(struct socket *so, struct unpcb *unp, struct thread *td) 1806 { 1807 int error; 1808 1809 UNP_LOCK_ASSERT(); 1810 1811 SOCK_LOCK(so); 1812 error = solisten_proto_check(so); 1813 if (error == 0) { 1814 cru2x(td->td_ucred, &unp->unp_peercred); 1815 unp->unp_flags |= UNP_HAVEPCCACHED; 1816 solisten_proto(so); 1817 } 1818 SOCK_UNLOCK(so); 1819 return (error); 1820 } 1821 1822 static void 1823 unp_scan(struct mbuf *m0, void (*op)(struct file *)) 1824 { 1825 struct mbuf *m; 1826 struct file **rp; 1827 struct cmsghdr *cm; 1828 void *data; 1829 int i; 1830 socklen_t clen, datalen; 1831 int qfds; 1832 1833 while (m0 != NULL) { 1834 for (m = m0; m; m = m->m_next) { 1835 if (m->m_type != MT_CONTROL) 1836 continue; 1837 1838 cm = mtod(m, struct cmsghdr *); 1839 clen = m->m_len; 1840 1841 while (cm != NULL) { 1842 if (sizeof(*cm) > clen || cm->cmsg_len > clen) 1843 break; 1844 1845 data = CMSG_DATA(cm); 1846 datalen = (caddr_t)cm + cm->cmsg_len 1847 - (caddr_t)data; 1848 1849 if (cm->cmsg_level == SOL_SOCKET && 1850 cm->cmsg_type == SCM_RIGHTS) { 1851 qfds = datalen / sizeof (struct file *); 1852 rp = data; 1853 for (i = 0; i < qfds; i++) 1854 (*op)(*rp++); 1855 } 1856 1857 if (CMSG_SPACE(datalen) < clen) { 1858 clen -= CMSG_SPACE(datalen); 1859 cm = (struct cmsghdr *) 1860 ((caddr_t)cm + CMSG_SPACE(datalen)); 1861 } else { 1862 clen = 0; 1863 cm = NULL; 1864 } 1865 } 1866 } 1867 m0 = m0->m_act; 1868 } 1869 } 1870 1871 static void 1872 unp_mark(struct file *fp) 1873 { 1874 if (fp->f_gcflag & FMARK) 1875 return; 1876 unp_defer++; 1877 fp->f_gcflag |= (FMARK|FDEFER); 1878 } 1879 1880 static void 1881 unp_discard(struct file *fp) 1882 { 1883 FILE_LOCK(fp); 1884 fp->f_msgcount--; 1885 unp_rights--; 1886 FILE_UNLOCK(fp); 1887 (void) closef(fp, (struct thread *)NULL); 1888 } 1889