1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 30 * $FreeBSD: src/sys/kern/uipc_usrreq.c,v 1.54.2.10 2003/03/04 17:28:09 nectar Exp $ 31 */ 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/kernel.h> 36 #include <sys/domain.h> 37 #include <sys/fcntl.h> 38 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 39 #include <sys/proc.h> 40 #include <sys/file.h> 41 #include <sys/filedesc.h> 42 #include <sys/mbuf.h> 43 #include <sys/nlookup.h> 44 #include <sys/protosw.h> 45 #include <sys/socket.h> 46 #include <sys/socketvar.h> 47 #include <sys/resourcevar.h> 48 #include <sys/stat.h> 49 #include <sys/mount.h> 50 #include <sys/sysctl.h> 51 #include <sys/un.h> 52 #include <sys/unpcb.h> 53 #include <sys/vnode.h> 54 55 #include <sys/file2.h> 56 #include <sys/spinlock2.h> 57 #include <sys/socketvar2.h> 58 #include <sys/msgport2.h> 59 60 typedef struct unp_defdiscard { 61 struct unp_defdiscard *next; 62 struct file *fp; 63 } *unp_defdiscard_t; 64 65 static MALLOC_DEFINE(M_UNPCB, "unpcb", "unpcb struct"); 66 static unp_gen_t unp_gencnt; 67 static u_int unp_count; 68 69 static struct unp_head unp_shead, unp_dhead; 70 71 static struct lwkt_token unp_token = LWKT_TOKEN_INITIALIZER(unp_token); 72 static int unp_defdiscard_nest; 73 static unp_defdiscard_t unp_defdiscard_base; 74 75 /* 76 * Unix communications domain. 77 * 78 * TODO: 79 * RDM 80 * rethink name space problems 81 * need a proper out-of-band 82 * lock pushdown 83 */ 84 static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 85 static ino_t unp_ino = 1; /* prototype for fake inode numbers */ 86 static struct spinlock unp_ino_spin = SPINLOCK_INITIALIZER(&unp_ino_spin); 87 88 static int unp_attach (struct socket *, struct pru_attach_info *); 89 static void unp_detach (struct unpcb *); 90 static int unp_bind (struct unpcb *,struct sockaddr *, struct thread *); 91 static int unp_connect (struct socket *,struct sockaddr *, 92 struct thread *); 93 static void unp_disconnect (struct unpcb *); 94 static void unp_shutdown (struct unpcb *); 95 static void unp_drop (struct unpcb *, int); 96 static void unp_gc (void); 97 static int unp_gc_clearmarks(struct file *, void *); 98 static int unp_gc_checkmarks(struct file *, void *); 99 static int unp_gc_checkrefs(struct file *, void *); 100 static int unp_revoke_gc_check(struct file *, void *); 101 static void unp_scan (struct mbuf *, void (*)(struct file *, void *), 102 void *data); 103 static void unp_mark (struct file *, void *data); 104 static void unp_discard (struct file *, void *); 105 static int unp_internalize (struct mbuf *, struct thread *); 106 static int unp_listen (struct unpcb *, struct thread *); 107 static void unp_fp_externalize(struct lwp *lp, struct file *fp, int fd); 108 109 /* 110 * SMP Considerations: 111 * 112 * Since unp_token will be automaticly released upon execution of 113 * blocking code, we need to reference unp_conn before any possible 114 * blocking code to prevent it from being ripped behind our back. 115 * 116 * Any adjustment to unp->unp_conn requires both the global unp_token 117 * AND the per-unp token (lwkt_token_pool_lookup(unp)) to be held. 118 * 119 * Any access to so_pcb to obtain unp requires the pool token for 120 * unp to be held. 121 */ 122 123 /* NOTE: unp_token MUST be held */ 124 static __inline void 125 unp_reference(struct unpcb *unp) 126 { 127 atomic_add_int(&unp->unp_refcnt, 1); 128 } 129 130 /* NOTE: unp_token MUST be held */ 131 static __inline void 132 unp_free(struct unpcb *unp) 133 { 134 KKASSERT(unp->unp_refcnt > 0); 135 if (atomic_fetchadd_int(&unp->unp_refcnt, -1) == 1) 136 unp_detach(unp); 137 } 138 139 /* 140 * NOTE: (so) is referenced from soabort*() and netmsg_pru_abort() 141 * will sofree() it when we return. 142 */ 143 static void 144 uipc_abort(netmsg_t msg) 145 { 146 struct unpcb *unp; 147 int error; 148 149 lwkt_gettoken(&unp_token); 150 unp = msg->base.nm_so->so_pcb; 151 if (unp) { 152 unp_drop(unp, ECONNABORTED); 153 unp_free(unp); 154 error = 0; 155 } else { 156 error = EINVAL; 157 } 158 lwkt_reltoken(&unp_token); 159 160 lwkt_replymsg(&msg->lmsg, error); 161 } 162 163 static void 164 uipc_accept(netmsg_t msg) 165 { 166 struct unpcb *unp; 167 int error; 168 169 lwkt_gettoken(&unp_token); 170 unp = msg->base.nm_so->so_pcb; 171 if (unp == NULL) { 172 error = EINVAL; 173 } else { 174 struct unpcb *unp2 = unp->unp_conn; 175 176 /* 177 * Pass back name of connected socket, 178 * if it was bound and we are still connected 179 * (our peer may have closed already!). 180 */ 181 if (unp2 && unp2->unp_addr) { 182 unp_reference(unp2); 183 *msg->accept.nm_nam = dup_sockaddr( 184 (struct sockaddr *)unp2->unp_addr); 185 unp_free(unp2); 186 } else { 187 *msg->accept.nm_nam = dup_sockaddr(&sun_noname); 188 } 189 error = 0; 190 } 191 lwkt_reltoken(&unp_token); 192 lwkt_replymsg(&msg->lmsg, error); 193 } 194 195 static void 196 uipc_attach(netmsg_t msg) 197 { 198 struct unpcb *unp; 199 int error; 200 201 lwkt_gettoken(&unp_token); 202 unp = msg->base.nm_so->so_pcb; 203 if (unp) 204 error = EISCONN; 205 else 206 error = unp_attach(msg->base.nm_so, msg->attach.nm_ai); 207 lwkt_reltoken(&unp_token); 208 lwkt_replymsg(&msg->lmsg, error); 209 } 210 211 static void 212 uipc_bind(netmsg_t msg) 213 { 214 struct unpcb *unp; 215 int error; 216 217 lwkt_gettoken(&unp_token); 218 unp = msg->base.nm_so->so_pcb; 219 if (unp) 220 error = unp_bind(unp, msg->bind.nm_nam, msg->bind.nm_td); 221 else 222 error = EINVAL; 223 lwkt_reltoken(&unp_token); 224 lwkt_replymsg(&msg->lmsg, error); 225 } 226 227 static void 228 uipc_connect(netmsg_t msg) 229 { 230 struct unpcb *unp; 231 int error; 232 233 unp = msg->base.nm_so->so_pcb; 234 if (unp) { 235 error = unp_connect(msg->base.nm_so, 236 msg->connect.nm_nam, 237 msg->connect.nm_td); 238 } else { 239 error = EINVAL; 240 } 241 lwkt_replymsg(&msg->lmsg, error); 242 } 243 244 static void 245 uipc_connect2(netmsg_t msg) 246 { 247 struct unpcb *unp; 248 int error; 249 250 unp = msg->connect2.nm_so1->so_pcb; 251 if (unp) { 252 error = unp_connect2(msg->connect2.nm_so1, 253 msg->connect2.nm_so2); 254 } else { 255 error = EINVAL; 256 } 257 lwkt_replymsg(&msg->lmsg, error); 258 } 259 260 /* control is EOPNOTSUPP */ 261 262 static void 263 uipc_detach(netmsg_t msg) 264 { 265 struct unpcb *unp; 266 int error; 267 268 lwkt_gettoken(&unp_token); 269 unp = msg->base.nm_so->so_pcb; 270 if (unp) { 271 unp_free(unp); 272 error = 0; 273 } else { 274 error = EINVAL; 275 } 276 lwkt_reltoken(&unp_token); 277 lwkt_replymsg(&msg->lmsg, error); 278 } 279 280 static void 281 uipc_disconnect(netmsg_t msg) 282 { 283 struct unpcb *unp; 284 int error; 285 286 lwkt_gettoken(&unp_token); 287 unp = msg->base.nm_so->so_pcb; 288 if (unp) { 289 unp_disconnect(unp); 290 error = 0; 291 } else { 292 error = EINVAL; 293 } 294 lwkt_reltoken(&unp_token); 295 lwkt_replymsg(&msg->lmsg, error); 296 } 297 298 static void 299 uipc_listen(netmsg_t msg) 300 { 301 struct unpcb *unp; 302 int error; 303 304 lwkt_gettoken(&unp_token); 305 unp = msg->base.nm_so->so_pcb; 306 if (unp == NULL || unp->unp_vnode == NULL) 307 error = EINVAL; 308 else 309 error = unp_listen(unp, msg->listen.nm_td); 310 lwkt_reltoken(&unp_token); 311 lwkt_replymsg(&msg->lmsg, error); 312 } 313 314 static void 315 uipc_peeraddr(netmsg_t msg) 316 { 317 struct unpcb *unp; 318 int error; 319 320 lwkt_gettoken(&unp_token); 321 unp = msg->base.nm_so->so_pcb; 322 if (unp == NULL) { 323 error = EINVAL; 324 } else if (unp->unp_conn && unp->unp_conn->unp_addr) { 325 struct unpcb *unp2 = unp->unp_conn; 326 327 unp_reference(unp2); 328 *msg->peeraddr.nm_nam = dup_sockaddr( 329 (struct sockaddr *)unp2->unp_addr); 330 unp_free(unp2); 331 error = 0; 332 } else { 333 /* 334 * XXX: It seems that this test always fails even when 335 * connection is established. So, this else clause is 336 * added as workaround to return PF_LOCAL sockaddr. 337 */ 338 *msg->peeraddr.nm_nam = dup_sockaddr(&sun_noname); 339 error = 0; 340 } 341 lwkt_reltoken(&unp_token); 342 lwkt_replymsg(&msg->lmsg, error); 343 } 344 345 static void 346 uipc_rcvd(netmsg_t msg) 347 { 348 struct unpcb *unp, *unp2; 349 struct socket *so; 350 struct socket *so2; 351 int error; 352 353 /* 354 * so_pcb is only modified with both the global and the unp 355 * pool token held. The unp pointer is invalid until we verify 356 * that it is good by re-checking so_pcb AFTER obtaining the token. 357 */ 358 so = msg->base.nm_so; 359 while ((unp = so->so_pcb) != NULL) { 360 lwkt_getpooltoken(unp); 361 if (unp == so->so_pcb) 362 break; 363 lwkt_relpooltoken(unp); 364 } 365 if (unp == NULL) { 366 error = EINVAL; 367 goto done; 368 } 369 /* pool token held */ 370 371 switch (so->so_type) { 372 case SOCK_DGRAM: 373 panic("uipc_rcvd DGRAM?"); 374 /*NOTREACHED*/ 375 case SOCK_STREAM: 376 case SOCK_SEQPACKET: 377 if (unp->unp_conn == NULL) 378 break; 379 unp2 = unp->unp_conn; /* protected by pool token */ 380 381 /* 382 * Because we are transfering mbufs directly to the 383 * peer socket we have to use SSB_STOP on the sender 384 * to prevent it from building up infinite mbufs. 385 * 386 * As in several places in this module w ehave to ref unp2 387 * to ensure that it does not get ripped out from under us 388 * if we block on the so2 token or in sowwakeup(). 389 */ 390 so2 = unp2->unp_socket; 391 unp_reference(unp2); 392 lwkt_gettoken(&so2->so_rcv.ssb_token); 393 if (so->so_rcv.ssb_cc < so2->so_snd.ssb_hiwat && 394 so->so_rcv.ssb_mbcnt < so2->so_snd.ssb_mbmax 395 ) { 396 atomic_clear_int(&so2->so_snd.ssb_flags, SSB_STOP); 397 398 sowwakeup(so2); 399 } 400 lwkt_reltoken(&so2->so_rcv.ssb_token); 401 unp_free(unp2); 402 break; 403 default: 404 panic("uipc_rcvd unknown socktype"); 405 /*NOTREACHED*/ 406 } 407 error = 0; 408 lwkt_relpooltoken(unp); 409 done: 410 lwkt_replymsg(&msg->lmsg, error); 411 } 412 413 /* pru_rcvoob is EOPNOTSUPP */ 414 415 static void 416 uipc_send(netmsg_t msg) 417 { 418 struct unpcb *unp, *unp2; 419 struct socket *so; 420 struct socket *so2; 421 struct mbuf *control; 422 struct mbuf *m; 423 int error = 0; 424 425 so = msg->base.nm_so; 426 control = msg->send.nm_control; 427 m = msg->send.nm_m; 428 429 /* 430 * so_pcb is only modified with both the global and the unp 431 * pool token held. The unp pointer is invalid until we verify 432 * that it is good by re-checking so_pcb AFTER obtaining the token. 433 */ 434 so = msg->base.nm_so; 435 while ((unp = so->so_pcb) != NULL) { 436 lwkt_getpooltoken(unp); 437 if (unp == so->so_pcb) 438 break; 439 lwkt_relpooltoken(unp); 440 } 441 if (unp == NULL) { 442 error = EINVAL; 443 goto done; 444 } 445 /* pool token held */ 446 447 if (msg->send.nm_flags & PRUS_OOB) { 448 error = EOPNOTSUPP; 449 goto release; 450 } 451 452 wakeup_start_delayed(); 453 454 if (control && (error = unp_internalize(control, msg->send.nm_td))) 455 goto release; 456 457 switch (so->so_type) { 458 case SOCK_DGRAM: 459 { 460 struct sockaddr *from; 461 462 if (msg->send.nm_addr) { 463 if (unp->unp_conn) { 464 error = EISCONN; 465 break; 466 } 467 error = unp_connect(so, 468 msg->send.nm_addr, 469 msg->send.nm_td); 470 if (error) 471 break; 472 } else { 473 if (unp->unp_conn == NULL) { 474 error = ENOTCONN; 475 break; 476 } 477 } 478 unp2 = unp->unp_conn; 479 so2 = unp2->unp_socket; 480 if (unp->unp_addr) 481 from = (struct sockaddr *)unp->unp_addr; 482 else 483 from = &sun_noname; 484 485 unp_reference(unp2); 486 487 lwkt_gettoken(&so2->so_rcv.ssb_token); 488 if (ssb_appendaddr(&so2->so_rcv, from, m, control)) { 489 sorwakeup(so2); 490 m = NULL; 491 control = NULL; 492 } else { 493 error = ENOBUFS; 494 } 495 if (msg->send.nm_addr) 496 unp_disconnect(unp); 497 lwkt_reltoken(&so2->so_rcv.ssb_token); 498 499 unp_free(unp2); 500 break; 501 } 502 503 case SOCK_STREAM: 504 case SOCK_SEQPACKET: 505 /* Connect if not connected yet. */ 506 /* 507 * Note: A better implementation would complain 508 * if not equal to the peer's address. 509 */ 510 if (!(so->so_state & SS_ISCONNECTED)) { 511 if (msg->send.nm_addr) { 512 error = unp_connect(so, 513 msg->send.nm_addr, 514 msg->send.nm_td); 515 if (error) 516 break; /* XXX */ 517 } else { 518 error = ENOTCONN; 519 break; 520 } 521 } 522 523 if (so->so_state & SS_CANTSENDMORE) { 524 error = EPIPE; 525 break; 526 } 527 if (unp->unp_conn == NULL) 528 panic("uipc_send connected but no connection?"); 529 unp2 = unp->unp_conn; 530 so2 = unp2->unp_socket; 531 532 unp_reference(unp2); 533 534 /* 535 * Send to paired receive port, and then reduce 536 * send buffer hiwater marks to maintain backpressure. 537 * Wake up readers. 538 */ 539 lwkt_gettoken(&so2->so_rcv.ssb_token); 540 if (control) { 541 if (ssb_appendcontrol(&so2->so_rcv, m, control)) { 542 control = NULL; 543 m = NULL; 544 } 545 } else if (so->so_type == SOCK_SEQPACKET) { 546 sbappendrecord(&so2->so_rcv.sb, m); 547 m = NULL; 548 } else { 549 sbappend(&so2->so_rcv.sb, m); 550 m = NULL; 551 } 552 553 /* 554 * Because we are transfering mbufs directly to the 555 * peer socket we have to use SSB_STOP on the sender 556 * to prevent it from building up infinite mbufs. 557 */ 558 if (so2->so_rcv.ssb_cc >= so->so_snd.ssb_hiwat || 559 so2->so_rcv.ssb_mbcnt >= so->so_snd.ssb_mbmax 560 ) { 561 atomic_set_int(&so->so_snd.ssb_flags, SSB_STOP); 562 } 563 lwkt_reltoken(&so2->so_rcv.ssb_token); 564 sorwakeup(so2); 565 566 unp_free(unp2); 567 break; 568 569 default: 570 panic("uipc_send unknown socktype"); 571 } 572 573 /* 574 * SEND_EOF is equivalent to a SEND followed by a SHUTDOWN. 575 */ 576 if (msg->send.nm_flags & PRUS_EOF) { 577 socantsendmore(so); 578 unp_shutdown(unp); 579 } 580 581 if (control && error != 0) 582 unp_dispose(control); 583 release: 584 lwkt_relpooltoken(unp); 585 wakeup_end_delayed(); 586 done: 587 588 if (control) 589 m_freem(control); 590 if (m) 591 m_freem(m); 592 lwkt_replymsg(&msg->lmsg, error); 593 } 594 595 /* 596 * MPSAFE 597 */ 598 static void 599 uipc_sense(netmsg_t msg) 600 { 601 struct unpcb *unp; 602 struct socket *so; 603 struct stat *sb; 604 int error; 605 606 so = msg->base.nm_so; 607 sb = msg->sense.nm_stat; 608 609 /* 610 * so_pcb is only modified with both the global and the unp 611 * pool token held. The unp pointer is invalid until we verify 612 * that it is good by re-checking so_pcb AFTER obtaining the token. 613 */ 614 while ((unp = so->so_pcb) != NULL) { 615 lwkt_getpooltoken(unp); 616 if (unp == so->so_pcb) 617 break; 618 lwkt_relpooltoken(unp); 619 } 620 if (unp == NULL) { 621 error = EINVAL; 622 goto done; 623 } 624 /* pool token held */ 625 626 sb->st_blksize = so->so_snd.ssb_hiwat; 627 sb->st_dev = NOUDEV; 628 if (unp->unp_ino == 0) { /* make up a non-zero inode number */ 629 spin_lock(&unp_ino_spin); 630 unp->unp_ino = unp_ino++; 631 spin_unlock(&unp_ino_spin); 632 } 633 sb->st_ino = unp->unp_ino; 634 error = 0; 635 lwkt_relpooltoken(unp); 636 done: 637 lwkt_replymsg(&msg->lmsg, error); 638 } 639 640 static void 641 uipc_shutdown(netmsg_t msg) 642 { 643 struct socket *so; 644 struct unpcb *unp; 645 int error; 646 647 /* 648 * so_pcb is only modified with both the global and the unp 649 * pool token held. The unp pointer is invalid until we verify 650 * that it is good by re-checking so_pcb AFTER obtaining the token. 651 */ 652 so = msg->base.nm_so; 653 while ((unp = so->so_pcb) != NULL) { 654 lwkt_getpooltoken(unp); 655 if (unp == so->so_pcb) 656 break; 657 lwkt_relpooltoken(unp); 658 } 659 if (unp) { 660 /* pool token held */ 661 socantsendmore(so); 662 unp_shutdown(unp); 663 lwkt_relpooltoken(unp); 664 error = 0; 665 } else { 666 error = EINVAL; 667 } 668 lwkt_replymsg(&msg->lmsg, error); 669 } 670 671 static void 672 uipc_sockaddr(netmsg_t msg) 673 { 674 struct socket *so; 675 struct unpcb *unp; 676 int error; 677 678 /* 679 * so_pcb is only modified with both the global and the unp 680 * pool token held. The unp pointer is invalid until we verify 681 * that it is good by re-checking so_pcb AFTER obtaining the token. 682 */ 683 so = msg->base.nm_so; 684 while ((unp = so->so_pcb) != NULL) { 685 lwkt_getpooltoken(unp); 686 if (unp == so->so_pcb) 687 break; 688 lwkt_relpooltoken(unp); 689 } 690 if (unp) { 691 /* pool token held */ 692 if (unp->unp_addr) { 693 *msg->sockaddr.nm_nam = 694 dup_sockaddr((struct sockaddr *)unp->unp_addr); 695 } 696 lwkt_relpooltoken(unp); 697 error = 0; 698 } else { 699 error = EINVAL; 700 } 701 lwkt_replymsg(&msg->lmsg, error); 702 } 703 704 struct pr_usrreqs uipc_usrreqs = { 705 .pru_abort = uipc_abort, 706 .pru_accept = uipc_accept, 707 .pru_attach = uipc_attach, 708 .pru_bind = uipc_bind, 709 .pru_connect = uipc_connect, 710 .pru_connect2 = uipc_connect2, 711 .pru_control = pr_generic_notsupp, 712 .pru_detach = uipc_detach, 713 .pru_disconnect = uipc_disconnect, 714 .pru_listen = uipc_listen, 715 .pru_peeraddr = uipc_peeraddr, 716 .pru_rcvd = uipc_rcvd, 717 .pru_rcvoob = pr_generic_notsupp, 718 .pru_send = uipc_send, 719 .pru_sense = uipc_sense, 720 .pru_shutdown = uipc_shutdown, 721 .pru_sockaddr = uipc_sockaddr, 722 .pru_sosend = sosend, 723 .pru_soreceive = soreceive 724 }; 725 726 void 727 uipc_ctloutput(netmsg_t msg) 728 { 729 struct socket *so; 730 struct sockopt *sopt; 731 struct unpcb *unp; 732 int error = 0; 733 734 lwkt_gettoken(&unp_token); 735 so = msg->base.nm_so; 736 sopt = msg->ctloutput.nm_sopt; 737 unp = so->so_pcb; 738 739 switch (sopt->sopt_dir) { 740 case SOPT_GET: 741 switch (sopt->sopt_name) { 742 case LOCAL_PEERCRED: 743 if (unp->unp_flags & UNP_HAVEPC) 744 soopt_from_kbuf(sopt, &unp->unp_peercred, 745 sizeof(unp->unp_peercred)); 746 else { 747 if (so->so_type == SOCK_STREAM) 748 error = ENOTCONN; 749 else if (so->so_type == SOCK_SEQPACKET) 750 error = ENOTCONN; 751 else 752 error = EINVAL; 753 } 754 break; 755 default: 756 error = EOPNOTSUPP; 757 break; 758 } 759 break; 760 case SOPT_SET: 761 default: 762 error = EOPNOTSUPP; 763 break; 764 } 765 lwkt_reltoken(&unp_token); 766 lwkt_replymsg(&msg->lmsg, error); 767 } 768 769 /* 770 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 771 * for stream sockets, although the total for sender and receiver is 772 * actually only PIPSIZ. 773 * 774 * Datagram sockets really use the sendspace as the maximum datagram size, 775 * and don't really want to reserve the sendspace. Their recvspace should 776 * be large enough for at least one max-size datagram plus address. 777 * 778 * We want the local send/recv space to be significant larger then lo0's 779 * mtu of 16384. 780 */ 781 #ifndef PIPSIZ 782 #define PIPSIZ 57344 783 #endif 784 static u_long unpst_sendspace = PIPSIZ; 785 static u_long unpst_recvspace = PIPSIZ; 786 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 787 static u_long unpdg_recvspace = 4*1024; 788 789 static int unp_rights; /* file descriptors in flight */ 790 static struct spinlock unp_spin = SPINLOCK_INITIALIZER(&unp_spin); 791 792 SYSCTL_DECL(_net_local_seqpacket); 793 SYSCTL_DECL(_net_local_stream); 794 SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 795 &unpst_sendspace, 0, "Size of stream socket send buffer"); 796 SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 797 &unpst_recvspace, 0, "Size of stream socket receive buffer"); 798 799 SYSCTL_DECL(_net_local_dgram); 800 SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 801 &unpdg_sendspace, 0, "Max datagram socket size"); 802 SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 803 &unpdg_recvspace, 0, "Size of datagram socket receive buffer"); 804 805 SYSCTL_DECL(_net_local); 806 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, 807 "File descriptors in flight"); 808 809 static int 810 unp_attach(struct socket *so, struct pru_attach_info *ai) 811 { 812 struct unpcb *unp; 813 int error; 814 815 lwkt_gettoken(&unp_token); 816 817 if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) { 818 switch (so->so_type) { 819 820 case SOCK_STREAM: 821 case SOCK_SEQPACKET: 822 error = soreserve(so, unpst_sendspace, unpst_recvspace, 823 ai->sb_rlimit); 824 break; 825 826 case SOCK_DGRAM: 827 error = soreserve(so, unpdg_sendspace, unpdg_recvspace, 828 ai->sb_rlimit); 829 break; 830 831 default: 832 panic("unp_attach"); 833 } 834 if (error) 835 goto failed; 836 } 837 unp = kmalloc(sizeof(*unp), M_UNPCB, M_WAITOK | M_ZERO | M_NULLOK); 838 if (unp == NULL) { 839 error = ENOBUFS; 840 goto failed; 841 } 842 unp->unp_refcnt = 1; 843 unp->unp_gencnt = ++unp_gencnt; 844 unp_count++; 845 LIST_INIT(&unp->unp_refs); 846 unp->unp_socket = so; 847 unp->unp_rvnode = ai->fd_rdir; /* jail cruft XXX JH */ 848 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead 849 : &unp_shead, unp, unp_link); 850 so->so_pcb = (caddr_t)unp; 851 soreference(so); 852 error = 0; 853 failed: 854 lwkt_reltoken(&unp_token); 855 return error; 856 } 857 858 static void 859 unp_detach(struct unpcb *unp) 860 { 861 struct socket *so; 862 863 lwkt_gettoken(&unp_token); 864 lwkt_getpooltoken(unp); 865 866 LIST_REMOVE(unp, unp_link); /* both tokens required */ 867 unp->unp_gencnt = ++unp_gencnt; 868 --unp_count; 869 if (unp->unp_vnode) { 870 unp->unp_vnode->v_socket = NULL; 871 vrele(unp->unp_vnode); 872 unp->unp_vnode = NULL; 873 } 874 if (unp->unp_conn) 875 unp_disconnect(unp); 876 while (!LIST_EMPTY(&unp->unp_refs)) 877 unp_drop(LIST_FIRST(&unp->unp_refs), ECONNRESET); 878 soisdisconnected(unp->unp_socket); 879 so = unp->unp_socket; 880 soreference(so); /* for delayed sorflush */ 881 KKASSERT(so->so_pcb == unp); 882 so->so_pcb = NULL; /* both tokens required */ 883 unp->unp_socket = NULL; 884 sofree(so); /* remove pcb ref */ 885 886 if (unp_rights) { 887 /* 888 * Normally the receive buffer is flushed later, 889 * in sofree, but if our receive buffer holds references 890 * to descriptors that are now garbage, we will dispose 891 * of those descriptor references after the garbage collector 892 * gets them (resulting in a "panic: closef: count < 0"). 893 */ 894 sorflush(so); 895 unp_gc(); 896 } 897 sofree(so); 898 lwkt_relpooltoken(unp); 899 lwkt_reltoken(&unp_token); 900 901 if (unp->unp_addr) 902 kfree(unp->unp_addr, M_SONAME); 903 kfree(unp, M_UNPCB); 904 } 905 906 static int 907 unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td) 908 { 909 struct proc *p = td->td_proc; 910 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 911 struct vnode *vp; 912 struct vattr vattr; 913 int error, namelen; 914 struct nlookupdata nd; 915 char buf[SOCK_MAXADDRLEN]; 916 917 lwkt_gettoken(&unp_token); 918 if (unp->unp_vnode != NULL) { 919 error = EINVAL; 920 goto failed; 921 } 922 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 923 if (namelen <= 0) { 924 error = EINVAL; 925 goto failed; 926 } 927 strncpy(buf, soun->sun_path, namelen); 928 buf[namelen] = 0; /* null-terminate the string */ 929 error = nlookup_init(&nd, buf, UIO_SYSSPACE, 930 NLC_LOCKVP | NLC_CREATE | NLC_REFDVP); 931 if (error == 0) 932 error = nlookup(&nd); 933 if (error == 0 && nd.nl_nch.ncp->nc_vp != NULL) 934 error = EADDRINUSE; 935 if (error) 936 goto done; 937 938 VATTR_NULL(&vattr); 939 vattr.va_type = VSOCK; 940 vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask); 941 error = VOP_NCREATE(&nd.nl_nch, nd.nl_dvp, &vp, nd.nl_cred, &vattr); 942 if (error == 0) { 943 if (unp->unp_vnode == NULL) { 944 vp->v_socket = unp->unp_socket; 945 unp->unp_vnode = vp; 946 unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam); 947 vn_unlock(vp); 948 } else { 949 vput(vp); /* late race */ 950 error = EINVAL; 951 } 952 } 953 done: 954 nlookup_done(&nd); 955 failed: 956 lwkt_reltoken(&unp_token); 957 return (error); 958 } 959 960 static int 961 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 962 { 963 struct proc *p = td->td_proc; 964 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 965 struct vnode *vp; 966 struct socket *so2, *so3; 967 struct unpcb *unp, *unp2, *unp3; 968 int error, len; 969 struct nlookupdata nd; 970 char buf[SOCK_MAXADDRLEN]; 971 972 lwkt_gettoken(&unp_token); 973 974 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 975 if (len <= 0) { 976 error = EINVAL; 977 goto failed; 978 } 979 strncpy(buf, soun->sun_path, len); 980 buf[len] = 0; 981 982 vp = NULL; 983 error = nlookup_init(&nd, buf, UIO_SYSSPACE, NLC_FOLLOW); 984 if (error == 0) 985 error = nlookup(&nd); 986 if (error == 0) 987 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp); 988 nlookup_done(&nd); 989 if (error) 990 goto failed; 991 992 if (vp->v_type != VSOCK) { 993 error = ENOTSOCK; 994 goto bad; 995 } 996 error = VOP_EACCESS(vp, VWRITE, p->p_ucred); 997 if (error) 998 goto bad; 999 so2 = vp->v_socket; 1000 if (so2 == NULL) { 1001 error = ECONNREFUSED; 1002 goto bad; 1003 } 1004 if (so->so_type != so2->so_type) { 1005 error = EPROTOTYPE; 1006 goto bad; 1007 } 1008 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 1009 if (!(so2->so_options & SO_ACCEPTCONN) || 1010 (so3 = sonewconn(so2, 0)) == NULL) { 1011 error = ECONNREFUSED; 1012 goto bad; 1013 } 1014 unp = so->so_pcb; 1015 if (unp->unp_conn) { /* race, already connected! */ 1016 error = EISCONN; 1017 sofree(so3); 1018 goto bad; 1019 } 1020 unp2 = so2->so_pcb; 1021 unp3 = so3->so_pcb; 1022 if (unp2->unp_addr) 1023 unp3->unp_addr = (struct sockaddr_un *) 1024 dup_sockaddr((struct sockaddr *)unp2->unp_addr); 1025 1026 /* 1027 * unp_peercred management: 1028 * 1029 * The connecter's (client's) credentials are copied 1030 * from its process structure at the time of connect() 1031 * (which is now). 1032 */ 1033 cru2x(p->p_ucred, &unp3->unp_peercred); 1034 unp3->unp_flags |= UNP_HAVEPC; 1035 /* 1036 * The receiver's (server's) credentials are copied 1037 * from the unp_peercred member of socket on which the 1038 * former called listen(); unp_listen() cached that 1039 * process's credentials at that time so we can use 1040 * them now. 1041 */ 1042 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 1043 ("unp_connect: listener without cached peercred")); 1044 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 1045 sizeof(unp->unp_peercred)); 1046 unp->unp_flags |= UNP_HAVEPC; 1047 1048 so2 = so3; 1049 } 1050 error = unp_connect2(so, so2); 1051 bad: 1052 vput(vp); 1053 failed: 1054 lwkt_reltoken(&unp_token); 1055 return (error); 1056 } 1057 1058 /* 1059 * Connect two unix domain sockets together. 1060 * 1061 * NOTE: Semantics for any change to unp_conn requires that the per-unp 1062 * pool token also be held. 1063 */ 1064 int 1065 unp_connect2(struct socket *so, struct socket *so2) 1066 { 1067 struct unpcb *unp; 1068 struct unpcb *unp2; 1069 1070 lwkt_gettoken(&unp_token); 1071 unp = so->so_pcb; 1072 if (so2->so_type != so->so_type) { 1073 lwkt_reltoken(&unp_token); 1074 return (EPROTOTYPE); 1075 } 1076 unp2 = so2->so_pcb; 1077 lwkt_getpooltoken(unp); 1078 lwkt_getpooltoken(unp2); 1079 1080 unp->unp_conn = unp2; 1081 1082 switch (so->so_type) { 1083 case SOCK_DGRAM: 1084 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 1085 soisconnected(so); 1086 break; 1087 1088 case SOCK_STREAM: 1089 case SOCK_SEQPACKET: 1090 unp2->unp_conn = unp; 1091 soisconnected(so); 1092 soisconnected(so2); 1093 break; 1094 1095 default: 1096 panic("unp_connect2"); 1097 } 1098 lwkt_relpooltoken(unp2); 1099 lwkt_relpooltoken(unp); 1100 lwkt_reltoken(&unp_token); 1101 return (0); 1102 } 1103 1104 /* 1105 * Disconnect a unix domain socket pair. 1106 * 1107 * NOTE: Semantics for any change to unp_conn requires that the per-unp 1108 * pool token also be held. 1109 */ 1110 static void 1111 unp_disconnect(struct unpcb *unp) 1112 { 1113 struct unpcb *unp2; 1114 1115 lwkt_gettoken(&unp_token); 1116 lwkt_getpooltoken(unp); 1117 1118 while ((unp2 = unp->unp_conn) != NULL) { 1119 lwkt_getpooltoken(unp2); 1120 if (unp2 == unp->unp_conn) 1121 break; 1122 lwkt_relpooltoken(unp2); 1123 } 1124 if (unp2 == NULL) 1125 goto done; 1126 1127 unp->unp_conn = NULL; 1128 1129 switch (unp->unp_socket->so_type) { 1130 case SOCK_DGRAM: 1131 LIST_REMOVE(unp, unp_reflink); 1132 soclrstate(unp->unp_socket, SS_ISCONNECTED); 1133 break; 1134 1135 case SOCK_STREAM: 1136 case SOCK_SEQPACKET: 1137 unp_reference(unp2); 1138 unp2->unp_conn = NULL; 1139 1140 soisdisconnected(unp->unp_socket); 1141 soisdisconnected(unp2->unp_socket); 1142 1143 unp_free(unp2); 1144 break; 1145 } 1146 lwkt_relpooltoken(unp2); 1147 done: 1148 lwkt_relpooltoken(unp); 1149 lwkt_reltoken(&unp_token); 1150 } 1151 1152 #ifdef notdef 1153 void 1154 unp_abort(struct unpcb *unp) 1155 { 1156 lwkt_gettoken(&unp_token); 1157 unp_free(unp); 1158 lwkt_reltoken(&unp_token); 1159 } 1160 #endif 1161 1162 static int 1163 prison_unpcb(struct thread *td, struct unpcb *unp) 1164 { 1165 struct proc *p; 1166 1167 if (td == NULL) 1168 return (0); 1169 if ((p = td->td_proc) == NULL) 1170 return (0); 1171 if (!p->p_ucred->cr_prison) 1172 return (0); 1173 if (p->p_fd->fd_rdir == unp->unp_rvnode) 1174 return (0); 1175 return (1); 1176 } 1177 1178 static int 1179 unp_pcblist(SYSCTL_HANDLER_ARGS) 1180 { 1181 int error, i, n; 1182 struct unpcb *unp, **unp_list; 1183 unp_gen_t gencnt; 1184 struct unp_head *head; 1185 1186 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 1187 1188 KKASSERT(curproc != NULL); 1189 1190 /* 1191 * The process of preparing the PCB list is too time-consuming and 1192 * resource-intensive to repeat twice on every request. 1193 */ 1194 if (req->oldptr == NULL) { 1195 n = unp_count; 1196 req->oldidx = (n + n/8) * sizeof(struct xunpcb); 1197 return 0; 1198 } 1199 1200 if (req->newptr != NULL) 1201 return EPERM; 1202 1203 lwkt_gettoken(&unp_token); 1204 1205 /* 1206 * OK, now we're committed to doing something. 1207 */ 1208 gencnt = unp_gencnt; 1209 n = unp_count; 1210 1211 unp_list = kmalloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 1212 1213 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 1214 unp = LIST_NEXT(unp, unp_link)) { 1215 if (unp->unp_gencnt <= gencnt && !prison_unpcb(req->td, unp)) 1216 unp_list[i++] = unp; 1217 } 1218 n = i; /* in case we lost some during malloc */ 1219 1220 error = 0; 1221 for (i = 0; i < n; i++) { 1222 unp = unp_list[i]; 1223 if (unp->unp_gencnt <= gencnt) { 1224 struct xunpcb xu; 1225 xu.xu_len = sizeof xu; 1226 xu.xu_unpp = unp; 1227 /* 1228 * XXX - need more locking here to protect against 1229 * connect/disconnect races for SMP. 1230 */ 1231 if (unp->unp_addr) 1232 bcopy(unp->unp_addr, &xu.xu_addr, 1233 unp->unp_addr->sun_len); 1234 if (unp->unp_conn && unp->unp_conn->unp_addr) 1235 bcopy(unp->unp_conn->unp_addr, 1236 &xu.xu_caddr, 1237 unp->unp_conn->unp_addr->sun_len); 1238 bcopy(unp, &xu.xu_unp, sizeof *unp); 1239 sotoxsocket(unp->unp_socket, &xu.xu_socket); 1240 error = SYSCTL_OUT(req, &xu, sizeof xu); 1241 } 1242 } 1243 lwkt_reltoken(&unp_token); 1244 kfree(unp_list, M_TEMP); 1245 1246 return error; 1247 } 1248 1249 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 1250 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 1251 "List of active local datagram sockets"); 1252 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 1253 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 1254 "List of active local stream sockets"); 1255 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, CTLFLAG_RD, 1256 (caddr_t)(long)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 1257 "List of active local seqpacket stream sockets"); 1258 1259 static void 1260 unp_shutdown(struct unpcb *unp) 1261 { 1262 struct socket *so; 1263 1264 if ((unp->unp_socket->so_type == SOCK_STREAM || 1265 unp->unp_socket->so_type == SOCK_SEQPACKET) && 1266 unp->unp_conn != NULL && (so = unp->unp_conn->unp_socket)) { 1267 socantrcvmore(so); 1268 } 1269 } 1270 1271 static void 1272 unp_drop(struct unpcb *unp, int err) 1273 { 1274 struct socket *so = unp->unp_socket; 1275 1276 so->so_error = err; 1277 unp_disconnect(unp); 1278 } 1279 1280 #ifdef notdef 1281 void 1282 unp_drain(void) 1283 { 1284 lwkt_gettoken(&unp_token); 1285 lwkt_reltoken(&unp_token); 1286 } 1287 #endif 1288 1289 int 1290 unp_externalize(struct mbuf *rights) 1291 { 1292 struct thread *td = curthread; 1293 struct proc *p = td->td_proc; /* XXX */ 1294 struct lwp *lp = td->td_lwp; 1295 struct cmsghdr *cm = mtod(rights, struct cmsghdr *); 1296 int *fdp; 1297 int i; 1298 struct file **rp; 1299 struct file *fp; 1300 int newfds = (cm->cmsg_len - (CMSG_DATA(cm) - (u_char *)cm)) 1301 / sizeof (struct file *); 1302 int f; 1303 1304 lwkt_gettoken(&unp_token); 1305 1306 /* 1307 * if the new FD's will not fit, then we free them all 1308 */ 1309 if (!fdavail(p, newfds)) { 1310 rp = (struct file **)CMSG_DATA(cm); 1311 for (i = 0; i < newfds; i++) { 1312 fp = *rp; 1313 /* 1314 * zero the pointer before calling unp_discard, 1315 * since it may end up in unp_gc().. 1316 */ 1317 *rp++ = NULL; 1318 unp_discard(fp, NULL); 1319 } 1320 lwkt_reltoken(&unp_token); 1321 return (EMSGSIZE); 1322 } 1323 1324 /* 1325 * now change each pointer to an fd in the global table to 1326 * an integer that is the index to the local fd table entry 1327 * that we set up to point to the global one we are transferring. 1328 * If sizeof (struct file *) is bigger than or equal to sizeof int, 1329 * then do it in forward order. In that case, an integer will 1330 * always come in the same place or before its corresponding 1331 * struct file pointer. 1332 * If sizeof (struct file *) is smaller than sizeof int, then 1333 * do it in reverse order. 1334 */ 1335 if (sizeof (struct file *) >= sizeof (int)) { 1336 fdp = (int *)CMSG_DATA(cm); 1337 rp = (struct file **)CMSG_DATA(cm); 1338 for (i = 0; i < newfds; i++) { 1339 if (fdalloc(p, 0, &f)) 1340 panic("unp_externalize"); 1341 fp = *rp++; 1342 unp_fp_externalize(lp, fp, f); 1343 *fdp++ = f; 1344 } 1345 } else { 1346 fdp = (int *)CMSG_DATA(cm) + newfds - 1; 1347 rp = (struct file **)CMSG_DATA(cm) + newfds - 1; 1348 for (i = 0; i < newfds; i++) { 1349 if (fdalloc(p, 0, &f)) 1350 panic("unp_externalize"); 1351 fp = *rp--; 1352 unp_fp_externalize(lp, fp, f); 1353 *fdp-- = f; 1354 } 1355 } 1356 1357 /* 1358 * Adjust length, in case sizeof(struct file *) and sizeof(int) 1359 * differs. 1360 */ 1361 cm->cmsg_len = CMSG_LEN(newfds * sizeof(int)); 1362 rights->m_len = cm->cmsg_len; 1363 1364 lwkt_reltoken(&unp_token); 1365 return (0); 1366 } 1367 1368 static void 1369 unp_fp_externalize(struct lwp *lp, struct file *fp, int fd) 1370 { 1371 struct file *fx; 1372 int error; 1373 1374 lwkt_gettoken(&unp_token); 1375 1376 if (lp) { 1377 KKASSERT(fd >= 0); 1378 if (fp->f_flag & FREVOKED) { 1379 kprintf("Warning: revoked fp exiting unix socket\n"); 1380 fx = NULL; 1381 error = falloc(lp, &fx, NULL); 1382 if (error == 0) 1383 fsetfd(lp->lwp_proc->p_fd, fx, fd); 1384 else 1385 fsetfd(lp->lwp_proc->p_fd, NULL, fd); 1386 fdrop(fx); 1387 } else { 1388 fsetfd(lp->lwp_proc->p_fd, fp, fd); 1389 } 1390 } 1391 spin_lock(&unp_spin); 1392 fp->f_msgcount--; 1393 unp_rights--; 1394 spin_unlock(&unp_spin); 1395 fdrop(fp); 1396 1397 lwkt_reltoken(&unp_token); 1398 } 1399 1400 1401 void 1402 unp_init(void) 1403 { 1404 LIST_INIT(&unp_dhead); 1405 LIST_INIT(&unp_shead); 1406 spin_init(&unp_spin); 1407 } 1408 1409 static int 1410 unp_internalize(struct mbuf *control, struct thread *td) 1411 { 1412 struct proc *p = td->td_proc; 1413 struct filedesc *fdescp; 1414 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1415 struct file **rp; 1416 struct file *fp; 1417 int i, fd, *fdp; 1418 struct cmsgcred *cmcred; 1419 int oldfds; 1420 u_int newlen; 1421 int error; 1422 1423 KKASSERT(p); 1424 lwkt_gettoken(&unp_token); 1425 1426 fdescp = p->p_fd; 1427 if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) || 1428 cm->cmsg_level != SOL_SOCKET || 1429 CMSG_ALIGN(cm->cmsg_len) != control->m_len) { 1430 error = EINVAL; 1431 goto done; 1432 } 1433 1434 /* 1435 * Fill in credential information. 1436 */ 1437 if (cm->cmsg_type == SCM_CREDS) { 1438 cmcred = (struct cmsgcred *)CMSG_DATA(cm); 1439 cmcred->cmcred_pid = p->p_pid; 1440 cmcred->cmcred_uid = p->p_ucred->cr_ruid; 1441 cmcred->cmcred_gid = p->p_ucred->cr_rgid; 1442 cmcred->cmcred_euid = p->p_ucred->cr_uid; 1443 cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups, 1444 CMGROUP_MAX); 1445 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1446 cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i]; 1447 error = 0; 1448 goto done; 1449 } 1450 1451 /* 1452 * cmsghdr may not be aligned, do not allow calculation(s) to 1453 * go negative. 1454 */ 1455 if (cm->cmsg_len < CMSG_LEN(0)) { 1456 error = EINVAL; 1457 goto done; 1458 } 1459 1460 oldfds = (cm->cmsg_len - CMSG_LEN(0)) / sizeof (int); 1461 1462 /* 1463 * check that all the FDs passed in refer to legal OPEN files 1464 * If not, reject the entire operation. 1465 */ 1466 fdp = (int *)CMSG_DATA(cm); 1467 for (i = 0; i < oldfds; i++) { 1468 fd = *fdp++; 1469 if ((unsigned)fd >= fdescp->fd_nfiles || 1470 fdescp->fd_files[fd].fp == NULL) { 1471 error = EBADF; 1472 goto done; 1473 } 1474 if (fdescp->fd_files[fd].fp->f_type == DTYPE_KQUEUE) { 1475 error = EOPNOTSUPP; 1476 goto done; 1477 } 1478 } 1479 /* 1480 * Now replace the integer FDs with pointers to 1481 * the associated global file table entry.. 1482 * Allocate a bigger buffer as necessary. But if an cluster is not 1483 * enough, return E2BIG. 1484 */ 1485 newlen = CMSG_LEN(oldfds * sizeof(struct file *)); 1486 if (newlen > MCLBYTES) { 1487 error = E2BIG; 1488 goto done; 1489 } 1490 if (newlen - control->m_len > M_TRAILINGSPACE(control)) { 1491 if (control->m_flags & M_EXT) { 1492 error = E2BIG; 1493 goto done; 1494 } 1495 MCLGET(control, MB_WAIT); 1496 if (!(control->m_flags & M_EXT)) { 1497 error = ENOBUFS; 1498 goto done; 1499 } 1500 1501 /* copy the data to the cluster */ 1502 memcpy(mtod(control, char *), cm, cm->cmsg_len); 1503 cm = mtod(control, struct cmsghdr *); 1504 } 1505 1506 /* 1507 * Adjust length, in case sizeof(struct file *) and sizeof(int) 1508 * differs. 1509 */ 1510 cm->cmsg_len = newlen; 1511 control->m_len = CMSG_ALIGN(newlen); 1512 1513 /* 1514 * Transform the file descriptors into struct file pointers. 1515 * If sizeof (struct file *) is bigger than or equal to sizeof int, 1516 * then do it in reverse order so that the int won't get until 1517 * we're done. 1518 * If sizeof (struct file *) is smaller than sizeof int, then 1519 * do it in forward order. 1520 */ 1521 if (sizeof (struct file *) >= sizeof (int)) { 1522 fdp = (int *)CMSG_DATA(cm) + oldfds - 1; 1523 rp = (struct file **)CMSG_DATA(cm) + oldfds - 1; 1524 for (i = 0; i < oldfds; i++) { 1525 fp = fdescp->fd_files[*fdp--].fp; 1526 *rp-- = fp; 1527 fhold(fp); 1528 spin_lock(&unp_spin); 1529 fp->f_msgcount++; 1530 unp_rights++; 1531 spin_unlock(&unp_spin); 1532 } 1533 } else { 1534 fdp = (int *)CMSG_DATA(cm); 1535 rp = (struct file **)CMSG_DATA(cm); 1536 for (i = 0; i < oldfds; i++) { 1537 fp = fdescp->fd_files[*fdp++].fp; 1538 *rp++ = fp; 1539 fhold(fp); 1540 spin_lock(&unp_spin); 1541 fp->f_msgcount++; 1542 unp_rights++; 1543 spin_unlock(&unp_spin); 1544 } 1545 } 1546 error = 0; 1547 done: 1548 lwkt_reltoken(&unp_token); 1549 return error; 1550 } 1551 1552 /* 1553 * Garbage collect in-transit file descriptors that get lost due to 1554 * loops (i.e. when a socket is sent to another process over itself, 1555 * and more complex situations). 1556 * 1557 * NOT MPSAFE - TODO socket flush code and maybe closef. Rest is MPSAFE. 1558 */ 1559 1560 struct unp_gc_info { 1561 struct file **extra_ref; 1562 struct file *locked_fp; 1563 int defer; 1564 int index; 1565 int maxindex; 1566 }; 1567 1568 static void 1569 unp_gc(void) 1570 { 1571 struct unp_gc_info info; 1572 static boolean_t unp_gcing; 1573 struct file **fpp; 1574 int i; 1575 1576 /* 1577 * Only one gc can be in-progress at any given moment 1578 */ 1579 spin_lock(&unp_spin); 1580 if (unp_gcing) { 1581 spin_unlock(&unp_spin); 1582 return; 1583 } 1584 unp_gcing = TRUE; 1585 spin_unlock(&unp_spin); 1586 1587 lwkt_gettoken(&unp_token); 1588 1589 /* 1590 * Before going through all this, set all FDs to be NOT defered 1591 * and NOT externally accessible (not marked). During the scan 1592 * a fd can be marked externally accessible but we may or may not 1593 * be able to immediately process it (controlled by FDEFER). 1594 * 1595 * If we loop sleep a bit. The complexity of the topology can cause 1596 * multiple loops. Also failure to acquire the socket's so_rcv 1597 * token can cause us to loop. 1598 */ 1599 allfiles_scan_exclusive(unp_gc_clearmarks, NULL); 1600 do { 1601 info.defer = 0; 1602 allfiles_scan_exclusive(unp_gc_checkmarks, &info); 1603 if (info.defer) 1604 tsleep(&info, 0, "gcagain", 1); 1605 } while (info.defer); 1606 1607 /* 1608 * We grab an extra reference to each of the file table entries 1609 * that are not otherwise accessible and then free the rights 1610 * that are stored in messages on them. 1611 * 1612 * The bug in the orginal code is a little tricky, so I'll describe 1613 * what's wrong with it here. 1614 * 1615 * It is incorrect to simply unp_discard each entry for f_msgcount 1616 * times -- consider the case of sockets A and B that contain 1617 * references to each other. On a last close of some other socket, 1618 * we trigger a gc since the number of outstanding rights (unp_rights) 1619 * is non-zero. If during the sweep phase the gc code un_discards, 1620 * we end up doing a (full) closef on the descriptor. A closef on A 1621 * results in the following chain. Closef calls soo_close, which 1622 * calls soclose. Soclose calls first (through the switch 1623 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply 1624 * returns because the previous instance had set unp_gcing, and 1625 * we return all the way back to soclose, which marks the socket 1626 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush 1627 * to free up the rights that are queued in messages on the socket A, 1628 * i.e., the reference on B. The sorflush calls via the dom_dispose 1629 * switch unp_dispose, which unp_scans with unp_discard. This second 1630 * instance of unp_discard just calls closef on B. 1631 * 1632 * Well, a similar chain occurs on B, resulting in a sorflush on B, 1633 * which results in another closef on A. Unfortunately, A is already 1634 * being closed, and the descriptor has already been marked with 1635 * SS_NOFDREF, and soclose panics at this point. 1636 * 1637 * Here, we first take an extra reference to each inaccessible 1638 * descriptor. Then, we call sorflush ourself, since we know 1639 * it is a Unix domain socket anyhow. After we destroy all the 1640 * rights carried in messages, we do a last closef to get rid 1641 * of our extra reference. This is the last close, and the 1642 * unp_detach etc will shut down the socket. 1643 * 1644 * 91/09/19, bsy@cs.cmu.edu 1645 */ 1646 info.extra_ref = kmalloc(256 * sizeof(struct file *), M_FILE, M_WAITOK); 1647 info.maxindex = 256; 1648 1649 do { 1650 /* 1651 * Look for matches 1652 */ 1653 info.index = 0; 1654 allfiles_scan_exclusive(unp_gc_checkrefs, &info); 1655 1656 /* 1657 * For each FD on our hit list, do the following two things 1658 */ 1659 for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp) { 1660 struct file *tfp = *fpp; 1661 if (tfp->f_type == DTYPE_SOCKET && tfp->f_data != NULL) 1662 sorflush((struct socket *)(tfp->f_data)); 1663 } 1664 for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp) 1665 closef(*fpp, NULL); 1666 } while (info.index == info.maxindex); 1667 1668 lwkt_reltoken(&unp_token); 1669 1670 kfree((caddr_t)info.extra_ref, M_FILE); 1671 unp_gcing = FALSE; 1672 } 1673 1674 /* 1675 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry 1676 */ 1677 static int 1678 unp_gc_checkrefs(struct file *fp, void *data) 1679 { 1680 struct unp_gc_info *info = data; 1681 1682 if (fp->f_count == 0) 1683 return(0); 1684 if (info->index == info->maxindex) 1685 return(-1); 1686 1687 /* 1688 * If all refs are from msgs, and it's not marked accessible 1689 * then it must be referenced from some unreachable cycle 1690 * of (shut-down) FDs, so include it in our 1691 * list of FDs to remove 1692 */ 1693 if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) { 1694 info->extra_ref[info->index++] = fp; 1695 fhold(fp); 1696 } 1697 return(0); 1698 } 1699 1700 /* 1701 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry 1702 */ 1703 static int 1704 unp_gc_clearmarks(struct file *fp, void *data __unused) 1705 { 1706 atomic_clear_int(&fp->f_flag, FMARK | FDEFER); 1707 return(0); 1708 } 1709 1710 /* 1711 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry 1712 */ 1713 static int 1714 unp_gc_checkmarks(struct file *fp, void *data) 1715 { 1716 struct unp_gc_info *info = data; 1717 struct socket *so; 1718 1719 /* 1720 * If the file is not open, skip it. Make sure it isn't marked 1721 * defered or we could loop forever, in case we somehow race 1722 * something. 1723 */ 1724 if (fp->f_count == 0) { 1725 if (fp->f_flag & FDEFER) 1726 atomic_clear_int(&fp->f_flag, FDEFER); 1727 return(0); 1728 } 1729 /* 1730 * If we already marked it as 'defer' in a 1731 * previous pass, then try process it this time 1732 * and un-mark it 1733 */ 1734 if (fp->f_flag & FDEFER) { 1735 atomic_clear_int(&fp->f_flag, FDEFER); 1736 } else { 1737 /* 1738 * if it's not defered, then check if it's 1739 * already marked.. if so skip it 1740 */ 1741 if (fp->f_flag & FMARK) 1742 return(0); 1743 /* 1744 * If all references are from messages 1745 * in transit, then skip it. it's not 1746 * externally accessible. 1747 */ 1748 if (fp->f_count == fp->f_msgcount) 1749 return(0); 1750 /* 1751 * If it got this far then it must be 1752 * externally accessible. 1753 */ 1754 atomic_set_int(&fp->f_flag, FMARK); 1755 } 1756 1757 /* 1758 * either it was defered, or it is externally 1759 * accessible and not already marked so. 1760 * Now check if it is possibly one of OUR sockets. 1761 */ 1762 if (fp->f_type != DTYPE_SOCKET || 1763 (so = (struct socket *)fp->f_data) == NULL) { 1764 return(0); 1765 } 1766 if (so->so_proto->pr_domain != &localdomain || 1767 !(so->so_proto->pr_flags & PR_RIGHTS)) { 1768 return(0); 1769 } 1770 1771 /* 1772 * So, Ok, it's one of our sockets and it IS externally accessible 1773 * (or was defered). Now we look to see if we hold any file 1774 * descriptors in its message buffers. Follow those links and mark 1775 * them as accessible too. 1776 * 1777 * We are holding multiple spinlocks here, if we cannot get the 1778 * token non-blocking defer until the next loop. 1779 */ 1780 info->locked_fp = fp; 1781 if (lwkt_trytoken(&so->so_rcv.ssb_token)) { 1782 unp_scan(so->so_rcv.ssb_mb, unp_mark, info); 1783 lwkt_reltoken(&so->so_rcv.ssb_token); 1784 } else { 1785 atomic_set_int(&fp->f_flag, FDEFER); 1786 ++info->defer; 1787 } 1788 return (0); 1789 } 1790 1791 /* 1792 * Scan all unix domain sockets and replace any revoked file pointers 1793 * found with the dummy file pointer fx. We don't worry about races 1794 * against file pointers being read out as those are handled in the 1795 * externalize code. 1796 */ 1797 1798 #define REVOKE_GC_MAXFILES 32 1799 1800 struct unp_revoke_gc_info { 1801 struct file *fx; 1802 struct file *fary[REVOKE_GC_MAXFILES]; 1803 int fcount; 1804 }; 1805 1806 void 1807 unp_revoke_gc(struct file *fx) 1808 { 1809 struct unp_revoke_gc_info info; 1810 int i; 1811 1812 lwkt_gettoken(&unp_token); 1813 info.fx = fx; 1814 do { 1815 info.fcount = 0; 1816 allfiles_scan_exclusive(unp_revoke_gc_check, &info); 1817 for (i = 0; i < info.fcount; ++i) 1818 unp_fp_externalize(NULL, info.fary[i], -1); 1819 } while (info.fcount == REVOKE_GC_MAXFILES); 1820 lwkt_reltoken(&unp_token); 1821 } 1822 1823 /* 1824 * Check for and replace revoked descriptors. 1825 * 1826 * WARNING: This routine is not allowed to block. 1827 */ 1828 static int 1829 unp_revoke_gc_check(struct file *fps, void *vinfo) 1830 { 1831 struct unp_revoke_gc_info *info = vinfo; 1832 struct file *fp; 1833 struct socket *so; 1834 struct mbuf *m0; 1835 struct mbuf *m; 1836 struct file **rp; 1837 struct cmsghdr *cm; 1838 int i; 1839 int qfds; 1840 1841 /* 1842 * Is this a unix domain socket with rights-passing abilities? 1843 */ 1844 if (fps->f_type != DTYPE_SOCKET) 1845 return (0); 1846 if ((so = (struct socket *)fps->f_data) == NULL) 1847 return(0); 1848 if (so->so_proto->pr_domain != &localdomain) 1849 return(0); 1850 if ((so->so_proto->pr_flags & PR_RIGHTS) == 0) 1851 return(0); 1852 1853 /* 1854 * Scan the mbufs for control messages and replace any revoked 1855 * descriptors we find. 1856 */ 1857 lwkt_gettoken(&so->so_rcv.ssb_token); 1858 m0 = so->so_rcv.ssb_mb; 1859 while (m0) { 1860 for (m = m0; m; m = m->m_next) { 1861 if (m->m_type != MT_CONTROL) 1862 continue; 1863 if (m->m_len < sizeof(*cm)) 1864 continue; 1865 cm = mtod(m, struct cmsghdr *); 1866 if (cm->cmsg_level != SOL_SOCKET || 1867 cm->cmsg_type != SCM_RIGHTS) { 1868 continue; 1869 } 1870 qfds = (cm->cmsg_len - CMSG_LEN(0)) / sizeof(void *); 1871 rp = (struct file **)CMSG_DATA(cm); 1872 for (i = 0; i < qfds; i++) { 1873 fp = rp[i]; 1874 if (fp->f_flag & FREVOKED) { 1875 kprintf("Warning: Removing revoked fp from unix domain socket queue\n"); 1876 fhold(info->fx); 1877 info->fx->f_msgcount++; 1878 unp_rights++; 1879 rp[i] = info->fx; 1880 info->fary[info->fcount++] = fp; 1881 } 1882 if (info->fcount == REVOKE_GC_MAXFILES) 1883 break; 1884 } 1885 if (info->fcount == REVOKE_GC_MAXFILES) 1886 break; 1887 } 1888 m0 = m0->m_nextpkt; 1889 if (info->fcount == REVOKE_GC_MAXFILES) 1890 break; 1891 } 1892 lwkt_reltoken(&so->so_rcv.ssb_token); 1893 1894 /* 1895 * Stop the scan if we filled up our array. 1896 */ 1897 if (info->fcount == REVOKE_GC_MAXFILES) 1898 return(-1); 1899 return(0); 1900 } 1901 1902 /* 1903 * Dispose of the fp's stored in a mbuf. 1904 * 1905 * The dds loop can cause additional fps to be entered onto the 1906 * list while it is running, flattening out the operation and avoiding 1907 * a deep kernel stack recursion. 1908 */ 1909 void 1910 unp_dispose(struct mbuf *m) 1911 { 1912 unp_defdiscard_t dds; 1913 1914 lwkt_gettoken(&unp_token); 1915 ++unp_defdiscard_nest; 1916 if (m) { 1917 unp_scan(m, unp_discard, NULL); 1918 } 1919 if (unp_defdiscard_nest == 1) { 1920 while ((dds = unp_defdiscard_base) != NULL) { 1921 unp_defdiscard_base = dds->next; 1922 closef(dds->fp, NULL); 1923 kfree(dds, M_UNPCB); 1924 } 1925 } 1926 --unp_defdiscard_nest; 1927 lwkt_reltoken(&unp_token); 1928 } 1929 1930 static int 1931 unp_listen(struct unpcb *unp, struct thread *td) 1932 { 1933 struct proc *p = td->td_proc; 1934 1935 KKASSERT(p); 1936 lwkt_gettoken(&unp_token); 1937 cru2x(p->p_ucred, &unp->unp_peercred); 1938 unp->unp_flags |= UNP_HAVEPCCACHED; 1939 lwkt_reltoken(&unp_token); 1940 return (0); 1941 } 1942 1943 static void 1944 unp_scan(struct mbuf *m0, void (*op)(struct file *, void *), void *data) 1945 { 1946 struct mbuf *m; 1947 struct file **rp; 1948 struct cmsghdr *cm; 1949 int i; 1950 int qfds; 1951 1952 while (m0) { 1953 for (m = m0; m; m = m->m_next) { 1954 if (m->m_type == MT_CONTROL && 1955 m->m_len >= sizeof(*cm)) { 1956 cm = mtod(m, struct cmsghdr *); 1957 if (cm->cmsg_level != SOL_SOCKET || 1958 cm->cmsg_type != SCM_RIGHTS) 1959 continue; 1960 qfds = (cm->cmsg_len - CMSG_LEN(0)) / 1961 sizeof(void *); 1962 rp = (struct file **)CMSG_DATA(cm); 1963 for (i = 0; i < qfds; i++) 1964 (*op)(*rp++, data); 1965 break; /* XXX, but saves time */ 1966 } 1967 } 1968 m0 = m0->m_nextpkt; 1969 } 1970 } 1971 1972 /* 1973 * Mark visibility. info->defer is recalculated on every pass. 1974 */ 1975 static void 1976 unp_mark(struct file *fp, void *data) 1977 { 1978 struct unp_gc_info *info = data; 1979 1980 if ((fp->f_flag & FMARK) == 0) { 1981 ++info->defer; 1982 atomic_set_int(&fp->f_flag, FMARK | FDEFER); 1983 } else if (fp->f_flag & FDEFER) { 1984 ++info->defer; 1985 } 1986 } 1987 1988 /* 1989 * Discard a fp previously held in a unix domain socket mbuf. To 1990 * avoid blowing out the kernel stack due to contrived chain-reactions 1991 * we may have to defer the operation to a higher procedural level. 1992 * 1993 * Caller holds unp_token 1994 */ 1995 static void 1996 unp_discard(struct file *fp, void *data __unused) 1997 { 1998 unp_defdiscard_t dds; 1999 2000 spin_lock(&unp_spin); 2001 fp->f_msgcount--; 2002 unp_rights--; 2003 spin_unlock(&unp_spin); 2004 2005 if (unp_defdiscard_nest) { 2006 dds = kmalloc(sizeof(*dds), M_UNPCB, M_WAITOK|M_ZERO); 2007 dds->fp = fp; 2008 dds->next = unp_defdiscard_base; 2009 unp_defdiscard_base = dds; 2010 } else { 2011 closef(fp, NULL); 2012 } 2013 } 2014 2015