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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * From: @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 34 * $FreeBSD: src/sys/kern/uipc_usrreq.c,v 1.54.2.10 2003/03/04 17:28:09 nectar Exp $ 35 * $DragonFly: src/sys/kern/uipc_usrreq.c,v 1.44 2008/09/06 05:44:58 dillon Exp $ 36 */ 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/kernel.h> 41 #include <sys/domain.h> 42 #include <sys/fcntl.h> 43 #include <sys/malloc.h> /* XXX must be before <sys/file.h> */ 44 #include <sys/proc.h> 45 #include <sys/file.h> 46 #include <sys/filedesc.h> 47 #include <sys/mbuf.h> 48 #include <sys/nlookup.h> 49 #include <sys/protosw.h> 50 #include <sys/socket.h> 51 #include <sys/socketvar.h> 52 #include <sys/resourcevar.h> 53 #include <sys/stat.h> 54 #include <sys/mount.h> 55 #include <sys/sysctl.h> 56 #include <sys/un.h> 57 #include <sys/unpcb.h> 58 #include <sys/vnode.h> 59 #include <sys/file2.h> 60 #include <sys/spinlock2.h> 61 62 63 static MALLOC_DEFINE(M_UNPCB, "unpcb", "unpcb struct"); 64 static unp_gen_t unp_gencnt; 65 static u_int unp_count; 66 67 static struct unp_head unp_shead, unp_dhead; 68 69 /* 70 * Unix communications domain. 71 * 72 * TODO: 73 * RDM 74 * rethink name space problems 75 * need a proper out-of-band 76 * lock pushdown 77 */ 78 static struct sockaddr sun_noname = { sizeof(sun_noname), AF_LOCAL }; 79 static ino_t unp_ino = 1; /* prototype for fake inode numbers */ 80 static struct spinlock unp_ino_spin = SPINLOCK_INITIALIZER(&unp_ino_spin); 81 82 static int unp_attach (struct socket *, struct pru_attach_info *); 83 static void unp_detach (struct unpcb *); 84 static int unp_bind (struct unpcb *,struct sockaddr *, struct thread *); 85 static int unp_connect (struct socket *,struct sockaddr *, 86 struct thread *); 87 static void unp_disconnect (struct unpcb *); 88 static void unp_shutdown (struct unpcb *); 89 static void unp_drop (struct unpcb *, int); 90 static void unp_gc (void); 91 static int unp_gc_clearmarks(struct file *, void *); 92 static int unp_gc_checkmarks(struct file *, void *); 93 static int unp_gc_checkrefs(struct file *, void *); 94 static int unp_revoke_gc_check(struct file *, void *); 95 static void unp_scan (struct mbuf *, void (*)(struct file *, void *), 96 void *data); 97 static void unp_mark (struct file *, void *data); 98 static void unp_discard (struct file *, void *); 99 static int unp_internalize (struct mbuf *, struct thread *); 100 static int unp_listen (struct unpcb *, struct thread *); 101 static void unp_fp_externalize(struct lwp *lp, struct file *fp, int fd); 102 103 static int 104 uipc_abort(struct socket *so) 105 { 106 struct unpcb *unp = so->so_pcb; 107 108 if (unp == NULL) 109 return EINVAL; 110 unp_drop(unp, ECONNABORTED); 111 unp_detach(unp); 112 sofree(so); 113 return 0; 114 } 115 116 static int 117 uipc_accept(struct socket *so, struct sockaddr **nam) 118 { 119 struct unpcb *unp = so->so_pcb; 120 121 if (unp == NULL) 122 return EINVAL; 123 124 /* 125 * Pass back name of connected socket, 126 * if it was bound and we are still connected 127 * (our peer may have closed already!). 128 */ 129 if (unp->unp_conn && unp->unp_conn->unp_addr) { 130 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr); 131 } else { 132 *nam = dup_sockaddr((struct sockaddr *)&sun_noname); 133 } 134 return 0; 135 } 136 137 static int 138 uipc_attach(struct socket *so, int proto, struct pru_attach_info *ai) 139 { 140 struct unpcb *unp = so->so_pcb; 141 142 if (unp != NULL) 143 return EISCONN; 144 return unp_attach(so, ai); 145 } 146 147 static int 148 uipc_bind(struct socket *so, struct sockaddr *nam, struct thread *td) 149 { 150 struct unpcb *unp = so->so_pcb; 151 152 if (unp == NULL) 153 return EINVAL; 154 return unp_bind(unp, nam, td); 155 } 156 157 static int 158 uipc_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 159 { 160 struct unpcb *unp = so->so_pcb; 161 162 if (unp == NULL) 163 return EINVAL; 164 return unp_connect(so, nam, td); 165 } 166 167 static int 168 uipc_connect2(struct socket *so1, struct socket *so2) 169 { 170 struct unpcb *unp = so1->so_pcb; 171 172 if (unp == NULL) 173 return EINVAL; 174 175 return unp_connect2(so1, so2); 176 } 177 178 /* control is EOPNOTSUPP */ 179 180 static int 181 uipc_detach(struct socket *so) 182 { 183 struct unpcb *unp = so->so_pcb; 184 185 if (unp == NULL) 186 return EINVAL; 187 188 unp_detach(unp); 189 return 0; 190 } 191 192 static int 193 uipc_disconnect(struct socket *so) 194 { 195 struct unpcb *unp = so->so_pcb; 196 197 if (unp == NULL) 198 return EINVAL; 199 unp_disconnect(unp); 200 return 0; 201 } 202 203 static int 204 uipc_listen(struct socket *so, struct thread *td) 205 { 206 struct unpcb *unp = so->so_pcb; 207 208 if (unp == NULL || unp->unp_vnode == NULL) 209 return EINVAL; 210 return unp_listen(unp, td); 211 } 212 213 static int 214 uipc_peeraddr(struct socket *so, struct sockaddr **nam) 215 { 216 struct unpcb *unp = so->so_pcb; 217 218 if (unp == NULL) 219 return EINVAL; 220 if (unp->unp_conn && unp->unp_conn->unp_addr) 221 *nam = dup_sockaddr((struct sockaddr *)unp->unp_conn->unp_addr); 222 else { 223 /* 224 * XXX: It seems that this test always fails even when 225 * connection is established. So, this else clause is 226 * added as workaround to return PF_LOCAL sockaddr. 227 */ 228 *nam = dup_sockaddr((struct sockaddr *)&sun_noname); 229 } 230 return 0; 231 } 232 233 static int 234 uipc_rcvd(struct socket *so, int flags) 235 { 236 struct unpcb *unp = so->so_pcb; 237 struct socket *so2; 238 239 if (unp == NULL) 240 return EINVAL; 241 switch (so->so_type) { 242 case SOCK_DGRAM: 243 panic("uipc_rcvd DGRAM?"); 244 /*NOTREACHED*/ 245 246 case SOCK_STREAM: 247 case SOCK_SEQPACKET: 248 if (unp->unp_conn == NULL) 249 break; 250 /* 251 * Because we are transfering mbufs directly to the 252 * peer socket we have to use SSB_STOP on the sender 253 * to prevent it from building up infinite mbufs. 254 */ 255 so2 = unp->unp_conn->unp_socket; 256 if (so->so_rcv.ssb_cc < so2->so_snd.ssb_hiwat && 257 so->so_rcv.ssb_mbcnt < so2->so_snd.ssb_mbmax 258 ) { 259 so2->so_snd.ssb_flags &= ~SSB_STOP; 260 sowwakeup(so2); 261 } 262 break; 263 264 default: 265 panic("uipc_rcvd unknown socktype"); 266 } 267 return 0; 268 } 269 270 /* pru_rcvoob is EOPNOTSUPP */ 271 272 static int 273 uipc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam, 274 struct mbuf *control, struct thread *td) 275 { 276 int error = 0; 277 struct unpcb *unp = so->so_pcb; 278 struct socket *so2; 279 280 if (unp == NULL) { 281 error = EINVAL; 282 goto release; 283 } 284 if (flags & PRUS_OOB) { 285 error = EOPNOTSUPP; 286 goto release; 287 } 288 289 if (control && (error = unp_internalize(control, td))) 290 goto release; 291 292 switch (so->so_type) { 293 case SOCK_DGRAM: 294 { 295 struct sockaddr *from; 296 297 if (nam) { 298 if (unp->unp_conn) { 299 error = EISCONN; 300 break; 301 } 302 error = unp_connect(so, nam, td); 303 if (error) 304 break; 305 } else { 306 if (unp->unp_conn == NULL) { 307 error = ENOTCONN; 308 break; 309 } 310 } 311 so2 = unp->unp_conn->unp_socket; 312 if (unp->unp_addr) 313 from = (struct sockaddr *)unp->unp_addr; 314 else 315 from = &sun_noname; 316 if (ssb_appendaddr(&so2->so_rcv, from, m, control)) { 317 sorwakeup(so2); 318 m = NULL; 319 control = NULL; 320 } else { 321 error = ENOBUFS; 322 } 323 if (nam) 324 unp_disconnect(unp); 325 break; 326 } 327 328 case SOCK_STREAM: 329 case SOCK_SEQPACKET: 330 /* Connect if not connected yet. */ 331 /* 332 * Note: A better implementation would complain 333 * if not equal to the peer's address. 334 */ 335 if (!(so->so_state & SS_ISCONNECTED)) { 336 if (nam) { 337 error = unp_connect(so, nam, td); 338 if (error) 339 break; /* XXX */ 340 } else { 341 error = ENOTCONN; 342 break; 343 } 344 } 345 346 if (so->so_state & SS_CANTSENDMORE) { 347 error = EPIPE; 348 break; 349 } 350 if (unp->unp_conn == NULL) 351 panic("uipc_send connected but no connection?"); 352 so2 = unp->unp_conn->unp_socket; 353 /* 354 * Send to paired receive port, and then reduce 355 * send buffer hiwater marks to maintain backpressure. 356 * Wake up readers. 357 */ 358 if (control) { 359 if (ssb_appendcontrol(&so2->so_rcv, m, control)) { 360 control = NULL; 361 m = NULL; 362 } 363 } else if (so->so_type == SOCK_SEQPACKET) { 364 sbappendrecord(&so2->so_rcv.sb, m); 365 m = NULL; 366 } else { 367 sbappend(&so2->so_rcv.sb, m); 368 m = NULL; 369 } 370 371 /* 372 * Because we are transfering mbufs directly to the 373 * peer socket we have to use SSB_STOP on the sender 374 * to prevent it from building up infinite mbufs. 375 */ 376 if (so2->so_rcv.ssb_cc >= so->so_snd.ssb_hiwat || 377 so2->so_rcv.ssb_mbcnt >= so->so_snd.ssb_mbmax 378 ) { 379 so->so_snd.ssb_flags |= SSB_STOP; 380 } 381 sorwakeup(so2); 382 break; 383 384 default: 385 panic("uipc_send unknown socktype"); 386 } 387 388 /* 389 * SEND_EOF is equivalent to a SEND followed by a SHUTDOWN. 390 */ 391 if (flags & PRUS_EOF) { 392 socantsendmore(so); 393 unp_shutdown(unp); 394 } 395 396 if (control && error != 0) 397 unp_dispose(control); 398 399 release: 400 if (control) 401 m_freem(control); 402 if (m) 403 m_freem(m); 404 return error; 405 } 406 407 /* 408 * MPSAFE 409 */ 410 static int 411 uipc_sense(struct socket *so, struct stat *sb) 412 { 413 struct unpcb *unp = so->so_pcb; 414 415 if (unp == NULL) 416 return EINVAL; 417 sb->st_blksize = so->so_snd.ssb_hiwat; 418 sb->st_dev = NOUDEV; 419 if (unp->unp_ino == 0) { /* make up a non-zero inode number */ 420 spin_lock_wr(&unp_ino_spin); 421 unp->unp_ino = unp_ino++; 422 spin_unlock_wr(&unp_ino_spin); 423 } 424 sb->st_ino = unp->unp_ino; 425 return (0); 426 } 427 428 static int 429 uipc_shutdown(struct socket *so) 430 { 431 struct unpcb *unp = so->so_pcb; 432 433 if (unp == NULL) 434 return EINVAL; 435 socantsendmore(so); 436 unp_shutdown(unp); 437 return 0; 438 } 439 440 static int 441 uipc_sockaddr(struct socket *so, struct sockaddr **nam) 442 { 443 struct unpcb *unp = so->so_pcb; 444 445 if (unp == NULL) 446 return EINVAL; 447 if (unp->unp_addr) 448 *nam = dup_sockaddr((struct sockaddr *)unp->unp_addr); 449 return 0; 450 } 451 452 struct pr_usrreqs uipc_usrreqs = { 453 .pru_abort = uipc_abort, 454 .pru_accept = uipc_accept, 455 .pru_attach = uipc_attach, 456 .pru_bind = uipc_bind, 457 .pru_connect = uipc_connect, 458 .pru_connect2 = uipc_connect2, 459 .pru_control = pru_control_notsupp, 460 .pru_detach = uipc_detach, 461 .pru_disconnect = uipc_disconnect, 462 .pru_listen = uipc_listen, 463 .pru_peeraddr = uipc_peeraddr, 464 .pru_rcvd = uipc_rcvd, 465 .pru_rcvoob = pru_rcvoob_notsupp, 466 .pru_send = uipc_send, 467 .pru_sense = uipc_sense, 468 .pru_shutdown = uipc_shutdown, 469 .pru_sockaddr = uipc_sockaddr, 470 .pru_sosend = sosend, 471 .pru_soreceive = soreceive, 472 .pru_sopoll = sopoll 473 }; 474 475 int 476 uipc_ctloutput(struct socket *so, struct sockopt *sopt) 477 { 478 struct unpcb *unp = so->so_pcb; 479 int error = 0; 480 481 switch (sopt->sopt_dir) { 482 case SOPT_GET: 483 switch (sopt->sopt_name) { 484 case LOCAL_PEERCRED: 485 if (unp->unp_flags & UNP_HAVEPC) 486 soopt_from_kbuf(sopt, &unp->unp_peercred, 487 sizeof(unp->unp_peercred)); 488 else { 489 if (so->so_type == SOCK_STREAM) 490 error = ENOTCONN; 491 else if (so->so_type == SOCK_SEQPACKET) 492 error = ENOTCONN; 493 else 494 error = EINVAL; 495 } 496 break; 497 default: 498 error = EOPNOTSUPP; 499 break; 500 } 501 break; 502 case SOPT_SET: 503 default: 504 error = EOPNOTSUPP; 505 break; 506 } 507 return (error); 508 } 509 510 /* 511 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 512 * for stream sockets, although the total for sender and receiver is 513 * actually only PIPSIZ. 514 * 515 * Datagram sockets really use the sendspace as the maximum datagram size, 516 * and don't really want to reserve the sendspace. Their recvspace should 517 * be large enough for at least one max-size datagram plus address. 518 * 519 * We want the local send/recv space to be significant larger then lo0's 520 * mtu of 16384. 521 */ 522 #ifndef PIPSIZ 523 #define PIPSIZ 57344 524 #endif 525 static u_long unpst_sendspace = PIPSIZ; 526 static u_long unpst_recvspace = PIPSIZ; 527 static u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 528 static u_long unpdg_recvspace = 4*1024; 529 530 static int unp_rights; /* file descriptors in flight */ 531 static struct spinlock unp_spin = SPINLOCK_INITIALIZER(&unp_spin); 532 533 SYSCTL_DECL(_net_local_seqpacket); 534 SYSCTL_DECL(_net_local_stream); 535 SYSCTL_INT(_net_local_stream, OID_AUTO, sendspace, CTLFLAG_RW, 536 &unpst_sendspace, 0, ""); 537 SYSCTL_INT(_net_local_stream, OID_AUTO, recvspace, CTLFLAG_RW, 538 &unpst_recvspace, 0, ""); 539 540 SYSCTL_DECL(_net_local_dgram); 541 SYSCTL_INT(_net_local_dgram, OID_AUTO, maxdgram, CTLFLAG_RW, 542 &unpdg_sendspace, 0, ""); 543 SYSCTL_INT(_net_local_dgram, OID_AUTO, recvspace, CTLFLAG_RW, 544 &unpdg_recvspace, 0, ""); 545 546 SYSCTL_DECL(_net_local); 547 SYSCTL_INT(_net_local, OID_AUTO, inflight, CTLFLAG_RD, &unp_rights, 0, ""); 548 549 static int 550 unp_attach(struct socket *so, struct pru_attach_info *ai) 551 { 552 struct unpcb *unp; 553 int error; 554 555 if (so->so_snd.ssb_hiwat == 0 || so->so_rcv.ssb_hiwat == 0) { 556 switch (so->so_type) { 557 558 case SOCK_STREAM: 559 case SOCK_SEQPACKET: 560 error = soreserve(so, unpst_sendspace, unpst_recvspace, 561 ai->sb_rlimit); 562 break; 563 564 case SOCK_DGRAM: 565 error = soreserve(so, unpdg_sendspace, unpdg_recvspace, 566 ai->sb_rlimit); 567 break; 568 569 default: 570 panic("unp_attach"); 571 } 572 if (error) 573 return (error); 574 } 575 unp = kmalloc(sizeof(*unp), M_UNPCB, M_NOWAIT|M_ZERO); 576 if (unp == NULL) 577 return (ENOBUFS); 578 unp->unp_gencnt = ++unp_gencnt; 579 unp_count++; 580 LIST_INIT(&unp->unp_refs); 581 unp->unp_socket = so; 582 unp->unp_rvnode = ai->fd_rdir; /* jail cruft XXX JH */ 583 LIST_INSERT_HEAD(so->so_type == SOCK_DGRAM ? &unp_dhead 584 : &unp_shead, unp, unp_link); 585 so->so_pcb = (caddr_t)unp; 586 so->so_port = sync_soport(so, NULL, NULL); 587 return (0); 588 } 589 590 static void 591 unp_detach(struct unpcb *unp) 592 { 593 LIST_REMOVE(unp, unp_link); 594 unp->unp_gencnt = ++unp_gencnt; 595 --unp_count; 596 if (unp->unp_vnode) { 597 unp->unp_vnode->v_socket = NULL; 598 vrele(unp->unp_vnode); 599 unp->unp_vnode = NULL; 600 } 601 if (unp->unp_conn) 602 unp_disconnect(unp); 603 while (!LIST_EMPTY(&unp->unp_refs)) 604 unp_drop(LIST_FIRST(&unp->unp_refs), ECONNRESET); 605 soisdisconnected(unp->unp_socket); 606 unp->unp_socket->so_pcb = NULL; 607 if (unp_rights) { 608 /* 609 * Normally the receive buffer is flushed later, 610 * in sofree, but if our receive buffer holds references 611 * to descriptors that are now garbage, we will dispose 612 * of those descriptor references after the garbage collector 613 * gets them (resulting in a "panic: closef: count < 0"). 614 */ 615 sorflush(unp->unp_socket); 616 unp_gc(); 617 } 618 if (unp->unp_addr) 619 kfree(unp->unp_addr, M_SONAME); 620 kfree(unp, M_UNPCB); 621 } 622 623 static int 624 unp_bind(struct unpcb *unp, struct sockaddr *nam, struct thread *td) 625 { 626 struct proc *p = td->td_proc; 627 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 628 struct vnode *vp; 629 struct vattr vattr; 630 int error, namelen; 631 struct nlookupdata nd; 632 char buf[SOCK_MAXADDRLEN]; 633 634 if (unp->unp_vnode != NULL) 635 return (EINVAL); 636 namelen = soun->sun_len - offsetof(struct sockaddr_un, sun_path); 637 if (namelen <= 0) 638 return (EINVAL); 639 strncpy(buf, soun->sun_path, namelen); 640 buf[namelen] = 0; /* null-terminate the string */ 641 error = nlookup_init(&nd, buf, UIO_SYSSPACE, 642 NLC_LOCKVP | NLC_CREATE | NLC_REFDVP); 643 if (error == 0) 644 error = nlookup(&nd); 645 if (error == 0 && nd.nl_nch.ncp->nc_vp != NULL) 646 error = EADDRINUSE; 647 if (error) 648 goto done; 649 650 VATTR_NULL(&vattr); 651 vattr.va_type = VSOCK; 652 vattr.va_mode = (ACCESSPERMS & ~p->p_fd->fd_cmask); 653 error = VOP_NCREATE(&nd.nl_nch, nd.nl_dvp, &vp, nd.nl_cred, &vattr); 654 if (error == 0) { 655 vp->v_socket = unp->unp_socket; 656 unp->unp_vnode = vp; 657 unp->unp_addr = (struct sockaddr_un *)dup_sockaddr(nam); 658 vn_unlock(vp); 659 } 660 done: 661 nlookup_done(&nd); 662 return (error); 663 } 664 665 static int 666 unp_connect(struct socket *so, struct sockaddr *nam, struct thread *td) 667 { 668 struct proc *p = td->td_proc; 669 struct sockaddr_un *soun = (struct sockaddr_un *)nam; 670 struct vnode *vp; 671 struct socket *so2, *so3; 672 struct unpcb *unp, *unp2, *unp3; 673 int error, len; 674 struct nlookupdata nd; 675 char buf[SOCK_MAXADDRLEN]; 676 677 KKASSERT(p); 678 679 len = nam->sa_len - offsetof(struct sockaddr_un, sun_path); 680 if (len <= 0) 681 return EINVAL; 682 strncpy(buf, soun->sun_path, len); 683 buf[len] = 0; 684 685 vp = NULL; 686 error = nlookup_init(&nd, buf, UIO_SYSSPACE, NLC_FOLLOW); 687 if (error == 0) 688 error = nlookup(&nd); 689 if (error == 0) 690 error = cache_vget(&nd.nl_nch, nd.nl_cred, LK_EXCLUSIVE, &vp); 691 nlookup_done(&nd); 692 if (error) 693 return (error); 694 695 if (vp->v_type != VSOCK) { 696 error = ENOTSOCK; 697 goto bad; 698 } 699 error = VOP_ACCESS(vp, VWRITE, p->p_ucred); 700 if (error) 701 goto bad; 702 so2 = vp->v_socket; 703 if (so2 == NULL) { 704 error = ECONNREFUSED; 705 goto bad; 706 } 707 if (so->so_type != so2->so_type) { 708 error = EPROTOTYPE; 709 goto bad; 710 } 711 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 712 if (!(so2->so_options & SO_ACCEPTCONN) || 713 (so3 = sonewconn(so2, 0)) == NULL) { 714 error = ECONNREFUSED; 715 goto bad; 716 } 717 unp = so->so_pcb; 718 unp2 = so2->so_pcb; 719 unp3 = so3->so_pcb; 720 if (unp2->unp_addr) 721 unp3->unp_addr = (struct sockaddr_un *) 722 dup_sockaddr((struct sockaddr *)unp2->unp_addr); 723 724 /* 725 * unp_peercred management: 726 * 727 * The connecter's (client's) credentials are copied 728 * from its process structure at the time of connect() 729 * (which is now). 730 */ 731 cru2x(p->p_ucred, &unp3->unp_peercred); 732 unp3->unp_flags |= UNP_HAVEPC; 733 /* 734 * The receiver's (server's) credentials are copied 735 * from the unp_peercred member of socket on which the 736 * former called listen(); unp_listen() cached that 737 * process's credentials at that time so we can use 738 * them now. 739 */ 740 KASSERT(unp2->unp_flags & UNP_HAVEPCCACHED, 741 ("unp_connect: listener without cached peercred")); 742 memcpy(&unp->unp_peercred, &unp2->unp_peercred, 743 sizeof(unp->unp_peercred)); 744 unp->unp_flags |= UNP_HAVEPC; 745 746 so2 = so3; 747 } 748 error = unp_connect2(so, so2); 749 bad: 750 vput(vp); 751 return (error); 752 } 753 754 int 755 unp_connect2(struct socket *so, struct socket *so2) 756 { 757 struct unpcb *unp = so->so_pcb; 758 struct unpcb *unp2; 759 760 if (so2->so_type != so->so_type) 761 return (EPROTOTYPE); 762 unp2 = so2->so_pcb; 763 unp->unp_conn = unp2; 764 switch (so->so_type) { 765 766 case SOCK_DGRAM: 767 LIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_reflink); 768 soisconnected(so); 769 break; 770 771 case SOCK_STREAM: 772 case SOCK_SEQPACKET: 773 unp2->unp_conn = unp; 774 soisconnected(so); 775 soisconnected(so2); 776 break; 777 778 default: 779 panic("unp_connect2"); 780 } 781 return (0); 782 } 783 784 static void 785 unp_disconnect(struct unpcb *unp) 786 { 787 struct unpcb *unp2 = unp->unp_conn; 788 789 if (unp2 == NULL) 790 return; 791 792 unp->unp_conn = NULL; 793 794 switch (unp->unp_socket->so_type) { 795 case SOCK_DGRAM: 796 LIST_REMOVE(unp, unp_reflink); 797 unp->unp_socket->so_state &= ~SS_ISCONNECTED; 798 break; 799 case SOCK_STREAM: 800 case SOCK_SEQPACKET: 801 soisdisconnected(unp->unp_socket); 802 unp2->unp_conn = NULL; 803 soisdisconnected(unp2->unp_socket); 804 break; 805 } 806 } 807 808 #ifdef notdef 809 void 810 unp_abort(struct unpcb *unp) 811 { 812 813 unp_detach(unp); 814 } 815 #endif 816 817 static int 818 prison_unpcb(struct thread *td, struct unpcb *unp) 819 { 820 struct proc *p; 821 822 if (td == NULL) 823 return (0); 824 if ((p = td->td_proc) == NULL) 825 return (0); 826 if (!p->p_ucred->cr_prison) 827 return (0); 828 if (p->p_fd->fd_rdir == unp->unp_rvnode) 829 return (0); 830 return (1); 831 } 832 833 static int 834 unp_pcblist(SYSCTL_HANDLER_ARGS) 835 { 836 int error, i, n; 837 struct unpcb *unp, **unp_list; 838 unp_gen_t gencnt; 839 struct unp_head *head; 840 841 head = ((intptr_t)arg1 == SOCK_DGRAM ? &unp_dhead : &unp_shead); 842 843 KKASSERT(curproc != NULL); 844 845 /* 846 * The process of preparing the PCB list is too time-consuming and 847 * resource-intensive to repeat twice on every request. 848 */ 849 if (req->oldptr == NULL) { 850 n = unp_count; 851 req->oldidx = (n + n/8) * sizeof(struct xunpcb); 852 return 0; 853 } 854 855 if (req->newptr != NULL) 856 return EPERM; 857 858 /* 859 * OK, now we're committed to doing something. 860 */ 861 gencnt = unp_gencnt; 862 n = unp_count; 863 864 unp_list = kmalloc(n * sizeof *unp_list, M_TEMP, M_WAITOK); 865 866 for (unp = LIST_FIRST(head), i = 0; unp && i < n; 867 unp = LIST_NEXT(unp, unp_link)) { 868 if (unp->unp_gencnt <= gencnt && !prison_unpcb(req->td, unp)) 869 unp_list[i++] = unp; 870 } 871 n = i; /* in case we lost some during malloc */ 872 873 error = 0; 874 for (i = 0; i < n; i++) { 875 unp = unp_list[i]; 876 if (unp->unp_gencnt <= gencnt) { 877 struct xunpcb xu; 878 xu.xu_len = sizeof xu; 879 xu.xu_unpp = unp; 880 /* 881 * XXX - need more locking here to protect against 882 * connect/disconnect races for SMP. 883 */ 884 if (unp->unp_addr) 885 bcopy(unp->unp_addr, &xu.xu_addr, 886 unp->unp_addr->sun_len); 887 if (unp->unp_conn && unp->unp_conn->unp_addr) 888 bcopy(unp->unp_conn->unp_addr, 889 &xu.xu_caddr, 890 unp->unp_conn->unp_addr->sun_len); 891 bcopy(unp, &xu.xu_unp, sizeof *unp); 892 sotoxsocket(unp->unp_socket, &xu.xu_socket); 893 error = SYSCTL_OUT(req, &xu, sizeof xu); 894 } 895 } 896 kfree(unp_list, M_TEMP); 897 return error; 898 } 899 900 SYSCTL_PROC(_net_local_dgram, OID_AUTO, pcblist, CTLFLAG_RD, 901 (caddr_t)(long)SOCK_DGRAM, 0, unp_pcblist, "S,xunpcb", 902 "List of active local datagram sockets"); 903 SYSCTL_PROC(_net_local_stream, OID_AUTO, pcblist, CTLFLAG_RD, 904 (caddr_t)(long)SOCK_STREAM, 0, unp_pcblist, "S,xunpcb", 905 "List of active local stream sockets"); 906 SYSCTL_PROC(_net_local_seqpacket, OID_AUTO, pcblist, CTLFLAG_RD, 907 (caddr_t)(long)SOCK_SEQPACKET, 0, unp_pcblist, "S,xunpcb", 908 "List of active local seqpacket stream sockets"); 909 910 static void 911 unp_shutdown(struct unpcb *unp) 912 { 913 struct socket *so; 914 915 if ((unp->unp_socket->so_type == SOCK_STREAM || 916 unp->unp_socket->so_type == SOCK_SEQPACKET) && 917 unp->unp_conn != NULL && (so = unp->unp_conn->unp_socket)) { 918 socantrcvmore(so); 919 } 920 } 921 922 static void 923 unp_drop(struct unpcb *unp, int err) 924 { 925 struct socket *so = unp->unp_socket; 926 927 so->so_error = err; 928 unp_disconnect(unp); 929 } 930 931 #ifdef notdef 932 void 933 unp_drain(void) 934 { 935 936 } 937 #endif 938 939 int 940 unp_externalize(struct mbuf *rights) 941 { 942 struct thread *td = curthread; 943 struct proc *p = td->td_proc; /* XXX */ 944 struct lwp *lp = td->td_lwp; 945 struct cmsghdr *cm = mtod(rights, struct cmsghdr *); 946 int *fdp; 947 int i; 948 struct file **rp; 949 struct file *fp; 950 int newfds = (cm->cmsg_len - (CMSG_DATA(cm) - (u_char *)cm)) 951 / sizeof (struct file *); 952 int f; 953 954 /* 955 * if the new FD's will not fit, then we free them all 956 */ 957 if (!fdavail(p, newfds)) { 958 rp = (struct file **)CMSG_DATA(cm); 959 for (i = 0; i < newfds; i++) { 960 fp = *rp; 961 /* 962 * zero the pointer before calling unp_discard, 963 * since it may end up in unp_gc().. 964 */ 965 *rp++ = 0; 966 unp_discard(fp, NULL); 967 } 968 return (EMSGSIZE); 969 } 970 971 /* 972 * now change each pointer to an fd in the global table to 973 * an integer that is the index to the local fd table entry 974 * that we set up to point to the global one we are transferring. 975 * If sizeof (struct file *) is bigger than or equal to sizeof int, 976 * then do it in forward order. In that case, an integer will 977 * always come in the same place or before its corresponding 978 * struct file pointer. 979 * If sizeof (struct file *) is smaller than sizeof int, then 980 * do it in reverse order. 981 */ 982 if (sizeof (struct file *) >= sizeof (int)) { 983 fdp = (int *)CMSG_DATA(cm); 984 rp = (struct file **)CMSG_DATA(cm); 985 for (i = 0; i < newfds; i++) { 986 if (fdalloc(p, 0, &f)) 987 panic("unp_externalize"); 988 fp = *rp++; 989 unp_fp_externalize(lp, fp, f); 990 *fdp++ = f; 991 } 992 } else { 993 fdp = (int *)CMSG_DATA(cm) + newfds - 1; 994 rp = (struct file **)CMSG_DATA(cm) + newfds - 1; 995 for (i = 0; i < newfds; i++) { 996 if (fdalloc(p, 0, &f)) 997 panic("unp_externalize"); 998 fp = *rp--; 999 unp_fp_externalize(lp, fp, f); 1000 *fdp-- = f; 1001 } 1002 } 1003 1004 /* 1005 * Adjust length, in case sizeof(struct file *) and sizeof(int) 1006 * differs. 1007 */ 1008 cm->cmsg_len = CMSG_LEN(newfds * sizeof(int)); 1009 rights->m_len = cm->cmsg_len; 1010 return (0); 1011 } 1012 1013 static void 1014 unp_fp_externalize(struct lwp *lp, struct file *fp, int fd) 1015 { 1016 struct file *fx; 1017 int error; 1018 1019 if (lp) { 1020 KKASSERT(fd >= 0); 1021 if (fp->f_flag & FREVOKED) { 1022 kprintf("Warning: revoked fp exiting unix socket\n"); 1023 fx = NULL; 1024 error = falloc(lp, &fx, NULL); 1025 if (error == 0) 1026 fsetfd(lp->lwp_proc->p_fd, fx, fd); 1027 else 1028 fsetfd(lp->lwp_proc->p_fd, NULL, fd); 1029 fdrop(fx); 1030 } else { 1031 fsetfd(lp->lwp_proc->p_fd, fp, fd); 1032 } 1033 } 1034 spin_lock_wr(&unp_spin); 1035 fp->f_msgcount--; 1036 unp_rights--; 1037 spin_unlock_wr(&unp_spin); 1038 fdrop(fp); 1039 } 1040 1041 1042 void 1043 unp_init(void) 1044 { 1045 LIST_INIT(&unp_dhead); 1046 LIST_INIT(&unp_shead); 1047 spin_init(&unp_spin); 1048 } 1049 1050 static int 1051 unp_internalize(struct mbuf *control, struct thread *td) 1052 { 1053 struct proc *p = td->td_proc; 1054 struct filedesc *fdescp; 1055 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 1056 struct file **rp; 1057 struct file *fp; 1058 int i, fd, *fdp; 1059 struct cmsgcred *cmcred; 1060 int oldfds; 1061 u_int newlen; 1062 1063 KKASSERT(p); 1064 fdescp = p->p_fd; 1065 if ((cm->cmsg_type != SCM_RIGHTS && cm->cmsg_type != SCM_CREDS) || 1066 cm->cmsg_level != SOL_SOCKET || 1067 CMSG_ALIGN(cm->cmsg_len) != control->m_len) { 1068 return (EINVAL); 1069 } 1070 1071 /* 1072 * Fill in credential information. 1073 */ 1074 if (cm->cmsg_type == SCM_CREDS) { 1075 cmcred = (struct cmsgcred *)CMSG_DATA(cm); 1076 cmcred->cmcred_pid = p->p_pid; 1077 cmcred->cmcred_uid = p->p_ucred->cr_ruid; 1078 cmcred->cmcred_gid = p->p_ucred->cr_rgid; 1079 cmcred->cmcred_euid = p->p_ucred->cr_uid; 1080 cmcred->cmcred_ngroups = MIN(p->p_ucred->cr_ngroups, 1081 CMGROUP_MAX); 1082 for (i = 0; i < cmcred->cmcred_ngroups; i++) 1083 cmcred->cmcred_groups[i] = p->p_ucred->cr_groups[i]; 1084 return(0); 1085 } 1086 1087 /* 1088 * cmsghdr may not be aligned, do not allow calculation(s) to 1089 * go negative. 1090 */ 1091 if (cm->cmsg_len < CMSG_LEN(0)) 1092 return(EINVAL); 1093 1094 oldfds = (cm->cmsg_len - CMSG_LEN(0)) / sizeof (int); 1095 1096 /* 1097 * check that all the FDs passed in refer to legal OPEN files 1098 * If not, reject the entire operation. 1099 */ 1100 fdp = (int *)CMSG_DATA(cm); 1101 for (i = 0; i < oldfds; i++) { 1102 fd = *fdp++; 1103 if ((unsigned)fd >= fdescp->fd_nfiles || 1104 fdescp->fd_files[fd].fp == NULL) 1105 return (EBADF); 1106 if (fdescp->fd_files[fd].fp->f_type == DTYPE_KQUEUE) 1107 return (EOPNOTSUPP); 1108 } 1109 /* 1110 * Now replace the integer FDs with pointers to 1111 * the associated global file table entry.. 1112 * Allocate a bigger buffer as necessary. But if an cluster is not 1113 * enough, return E2BIG. 1114 */ 1115 newlen = CMSG_LEN(oldfds * sizeof(struct file *)); 1116 if (newlen > MCLBYTES) 1117 return (E2BIG); 1118 if (newlen - control->m_len > M_TRAILINGSPACE(control)) { 1119 if (control->m_flags & M_EXT) 1120 return (E2BIG); 1121 MCLGET(control, MB_WAIT); 1122 if (!(control->m_flags & M_EXT)) 1123 return (ENOBUFS); 1124 1125 /* copy the data to the cluster */ 1126 memcpy(mtod(control, char *), cm, cm->cmsg_len); 1127 cm = mtod(control, struct cmsghdr *); 1128 } 1129 1130 /* 1131 * Adjust length, in case sizeof(struct file *) and sizeof(int) 1132 * differs. 1133 */ 1134 cm->cmsg_len = newlen; 1135 control->m_len = CMSG_ALIGN(newlen); 1136 1137 /* 1138 * Transform the file descriptors into struct file pointers. 1139 * If sizeof (struct file *) is bigger than or equal to sizeof int, 1140 * then do it in reverse order so that the int won't get until 1141 * we're done. 1142 * If sizeof (struct file *) is smaller than sizeof int, then 1143 * do it in forward order. 1144 */ 1145 if (sizeof (struct file *) >= sizeof (int)) { 1146 fdp = (int *)CMSG_DATA(cm) + oldfds - 1; 1147 rp = (struct file **)CMSG_DATA(cm) + oldfds - 1; 1148 for (i = 0; i < oldfds; i++) { 1149 fp = fdescp->fd_files[*fdp--].fp; 1150 *rp-- = fp; 1151 fhold(fp); 1152 spin_lock_wr(&unp_spin); 1153 fp->f_msgcount++; 1154 unp_rights++; 1155 spin_unlock_wr(&unp_spin); 1156 } 1157 } else { 1158 fdp = (int *)CMSG_DATA(cm); 1159 rp = (struct file **)CMSG_DATA(cm); 1160 for (i = 0; i < oldfds; i++) { 1161 fp = fdescp->fd_files[*fdp++].fp; 1162 *rp++ = fp; 1163 fhold(fp); 1164 spin_lock_wr(&unp_spin); 1165 fp->f_msgcount++; 1166 unp_rights++; 1167 spin_unlock_wr(&unp_spin); 1168 } 1169 } 1170 return (0); 1171 } 1172 1173 /* 1174 * Garbage collect in-transit file descriptors that get lost due to 1175 * loops (i.e. when a socket is sent to another process over itself, 1176 * and more complex situations). 1177 * 1178 * NOT MPSAFE - TODO socket flush code and maybe closef. Rest is MPSAFE. 1179 */ 1180 1181 struct unp_gc_info { 1182 struct file **extra_ref; 1183 struct file *locked_fp; 1184 int defer; 1185 int index; 1186 int maxindex; 1187 }; 1188 1189 static void 1190 unp_gc(void) 1191 { 1192 struct unp_gc_info info; 1193 static boolean_t unp_gcing; 1194 struct file **fpp; 1195 int i; 1196 1197 spin_lock_wr(&unp_spin); 1198 if (unp_gcing) { 1199 spin_unlock_wr(&unp_spin); 1200 return; 1201 } 1202 unp_gcing = TRUE; 1203 spin_unlock_wr(&unp_spin); 1204 1205 /* 1206 * before going through all this, set all FDs to 1207 * be NOT defered and NOT externally accessible 1208 */ 1209 info.defer = 0; 1210 allfiles_scan_exclusive(unp_gc_clearmarks, NULL); 1211 do { 1212 allfiles_scan_exclusive(unp_gc_checkmarks, &info); 1213 } while (info.defer); 1214 1215 /* 1216 * We grab an extra reference to each of the file table entries 1217 * that are not otherwise accessible and then free the rights 1218 * that are stored in messages on them. 1219 * 1220 * The bug in the orginal code is a little tricky, so I'll describe 1221 * what's wrong with it here. 1222 * 1223 * It is incorrect to simply unp_discard each entry for f_msgcount 1224 * times -- consider the case of sockets A and B that contain 1225 * references to each other. On a last close of some other socket, 1226 * we trigger a gc since the number of outstanding rights (unp_rights) 1227 * is non-zero. If during the sweep phase the gc code un_discards, 1228 * we end up doing a (full) closef on the descriptor. A closef on A 1229 * results in the following chain. Closef calls soo_close, which 1230 * calls soclose. Soclose calls first (through the switch 1231 * uipc_usrreq) unp_detach, which re-invokes unp_gc. Unp_gc simply 1232 * returns because the previous instance had set unp_gcing, and 1233 * we return all the way back to soclose, which marks the socket 1234 * with SS_NOFDREF, and then calls sofree. Sofree calls sorflush 1235 * to free up the rights that are queued in messages on the socket A, 1236 * i.e., the reference on B. The sorflush calls via the dom_dispose 1237 * switch unp_dispose, which unp_scans with unp_discard. This second 1238 * instance of unp_discard just calls closef on B. 1239 * 1240 * Well, a similar chain occurs on B, resulting in a sorflush on B, 1241 * which results in another closef on A. Unfortunately, A is already 1242 * being closed, and the descriptor has already been marked with 1243 * SS_NOFDREF, and soclose panics at this point. 1244 * 1245 * Here, we first take an extra reference to each inaccessible 1246 * descriptor. Then, we call sorflush ourself, since we know 1247 * it is a Unix domain socket anyhow. After we destroy all the 1248 * rights carried in messages, we do a last closef to get rid 1249 * of our extra reference. This is the last close, and the 1250 * unp_detach etc will shut down the socket. 1251 * 1252 * 91/09/19, bsy@cs.cmu.edu 1253 */ 1254 info.extra_ref = kmalloc(256 * sizeof(struct file *), M_FILE, M_WAITOK); 1255 info.maxindex = 256; 1256 1257 do { 1258 /* 1259 * Look for matches 1260 */ 1261 info.index = 0; 1262 allfiles_scan_exclusive(unp_gc_checkrefs, &info); 1263 1264 /* 1265 * For each FD on our hit list, do the following two things 1266 */ 1267 for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp) { 1268 struct file *tfp = *fpp; 1269 if (tfp->f_type == DTYPE_SOCKET && tfp->f_data != NULL) 1270 sorflush((struct socket *)(tfp->f_data)); 1271 } 1272 for (i = info.index, fpp = info.extra_ref; --i >= 0; ++fpp) 1273 closef(*fpp, NULL); 1274 } while (info.index == info.maxindex); 1275 kfree((caddr_t)info.extra_ref, M_FILE); 1276 unp_gcing = FALSE; 1277 } 1278 1279 /* 1280 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry 1281 */ 1282 static int 1283 unp_gc_checkrefs(struct file *fp, void *data) 1284 { 1285 struct unp_gc_info *info = data; 1286 1287 if (fp->f_count == 0) 1288 return(0); 1289 if (info->index == info->maxindex) 1290 return(-1); 1291 1292 /* 1293 * If all refs are from msgs, and it's not marked accessible 1294 * then it must be referenced from some unreachable cycle 1295 * of (shut-down) FDs, so include it in our 1296 * list of FDs to remove 1297 */ 1298 if (fp->f_count == fp->f_msgcount && !(fp->f_flag & FMARK)) { 1299 info->extra_ref[info->index++] = fp; 1300 fhold(fp); 1301 } 1302 return(0); 1303 } 1304 1305 /* 1306 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry 1307 */ 1308 static int 1309 unp_gc_clearmarks(struct file *fp, void *data __unused) 1310 { 1311 atomic_clear_int(&fp->f_flag, FMARK | FDEFER); 1312 return(0); 1313 } 1314 1315 /* 1316 * MPSAFE - NOTE: filehead list and file pointer spinlocked on entry 1317 */ 1318 static int 1319 unp_gc_checkmarks(struct file *fp, void *data) 1320 { 1321 struct unp_gc_info *info = data; 1322 struct socket *so; 1323 1324 /* 1325 * If the file is not open, skip it 1326 */ 1327 if (fp->f_count == 0) 1328 return(0); 1329 /* 1330 * If we already marked it as 'defer' in a 1331 * previous pass, then try process it this time 1332 * and un-mark it 1333 */ 1334 if (fp->f_flag & FDEFER) { 1335 atomic_clear_int(&fp->f_flag, FDEFER); 1336 --info->defer; 1337 } else { 1338 /* 1339 * if it's not defered, then check if it's 1340 * already marked.. if so skip it 1341 */ 1342 if (fp->f_flag & FMARK) 1343 return(0); 1344 /* 1345 * If all references are from messages 1346 * in transit, then skip it. it's not 1347 * externally accessible. 1348 */ 1349 if (fp->f_count == fp->f_msgcount) 1350 return(0); 1351 /* 1352 * If it got this far then it must be 1353 * externally accessible. 1354 */ 1355 atomic_set_int(&fp->f_flag, FMARK); 1356 } 1357 1358 /* 1359 * either it was defered, or it is externally 1360 * accessible and not already marked so. 1361 * Now check if it is possibly one of OUR sockets. 1362 */ 1363 if (fp->f_type != DTYPE_SOCKET || 1364 (so = (struct socket *)fp->f_data) == NULL) 1365 return(0); 1366 if (so->so_proto->pr_domain != &localdomain || 1367 !(so->so_proto->pr_flags & PR_RIGHTS)) 1368 return(0); 1369 #ifdef notdef 1370 if (so->so_rcv.ssb_flags & SSB_LOCK) { 1371 /* 1372 * This is problematical; it's not clear 1373 * we need to wait for the sockbuf to be 1374 * unlocked (on a uniprocessor, at least), 1375 * and it's also not clear what to do 1376 * if sbwait returns an error due to receipt 1377 * of a signal. If sbwait does return 1378 * an error, we'll go into an infinite 1379 * loop. Delete all of this for now. 1380 */ 1381 sbwait(&so->so_rcv); 1382 goto restart; 1383 } 1384 #endif 1385 /* 1386 * So, Ok, it's one of our sockets and it IS externally 1387 * accessible (or was defered). Now we look 1388 * to see if we hold any file descriptors in its 1389 * message buffers. Follow those links and mark them 1390 * as accessible too. 1391 */ 1392 info->locked_fp = fp; 1393 /* spin_lock_wr(&so->so_rcv.sb_spin); */ 1394 unp_scan(so->so_rcv.ssb_mb, unp_mark, info); 1395 /* spin_unlock_wr(&so->so_rcv.sb_spin);*/ 1396 return (0); 1397 } 1398 1399 /* 1400 * Scan all unix domain sockets and replace any revoked file pointers 1401 * found with the dummy file pointer fx. We don't worry about races 1402 * against file pointers being read out as those are handled in the 1403 * externalize code. 1404 */ 1405 1406 #define REVOKE_GC_MAXFILES 32 1407 1408 struct unp_revoke_gc_info { 1409 struct file *fx; 1410 struct file *fary[REVOKE_GC_MAXFILES]; 1411 int fcount; 1412 }; 1413 1414 void 1415 unp_revoke_gc(struct file *fx) 1416 { 1417 struct unp_revoke_gc_info info; 1418 int i; 1419 1420 info.fx = fx; 1421 do { 1422 info.fcount = 0; 1423 allfiles_scan_exclusive(unp_revoke_gc_check, &info); 1424 for (i = 0; i < info.fcount; ++i) 1425 unp_fp_externalize(NULL, info.fary[i], -1); 1426 } while (info.fcount == REVOKE_GC_MAXFILES); 1427 } 1428 1429 /* 1430 * Check for and replace revoked descriptors. 1431 * 1432 * WARNING: This routine is not allowed to block. 1433 */ 1434 static int 1435 unp_revoke_gc_check(struct file *fps, void *vinfo) 1436 { 1437 struct unp_revoke_gc_info *info = vinfo; 1438 struct file *fp; 1439 struct socket *so; 1440 struct mbuf *m0; 1441 struct mbuf *m; 1442 struct file **rp; 1443 struct cmsghdr *cm; 1444 int i; 1445 int qfds; 1446 1447 /* 1448 * Is this a unix domain socket with rights-passing abilities? 1449 */ 1450 if (fps->f_type != DTYPE_SOCKET) 1451 return (0); 1452 if ((so = (struct socket *)fps->f_data) == NULL) 1453 return(0); 1454 if (so->so_proto->pr_domain != &localdomain) 1455 return(0); 1456 if ((so->so_proto->pr_flags & PR_RIGHTS) == 0) 1457 return(0); 1458 1459 /* 1460 * Scan the mbufs for control messages and replace any revoked 1461 * descriptors we find. 1462 */ 1463 m0 = so->so_rcv.ssb_mb; 1464 while (m0) { 1465 for (m = m0; m; m = m->m_next) { 1466 if (m->m_type != MT_CONTROL) 1467 continue; 1468 if (m->m_len < sizeof(*cm)) 1469 continue; 1470 cm = mtod(m, struct cmsghdr *); 1471 if (cm->cmsg_level != SOL_SOCKET || 1472 cm->cmsg_type != SCM_RIGHTS) { 1473 continue; 1474 } 1475 qfds = (cm->cmsg_len - CMSG_LEN(0)) / sizeof(void *); 1476 rp = (struct file **)CMSG_DATA(cm); 1477 for (i = 0; i < qfds; i++) { 1478 fp = rp[i]; 1479 if (fp->f_flag & FREVOKED) { 1480 kprintf("Warning: Removing revoked fp from unix domain socket queue\n"); 1481 fhold(info->fx); 1482 info->fx->f_msgcount++; 1483 unp_rights++; 1484 rp[i] = info->fx; 1485 info->fary[info->fcount++] = fp; 1486 } 1487 if (info->fcount == REVOKE_GC_MAXFILES) 1488 break; 1489 } 1490 if (info->fcount == REVOKE_GC_MAXFILES) 1491 break; 1492 } 1493 m0 = m0->m_nextpkt; 1494 if (info->fcount == REVOKE_GC_MAXFILES) 1495 break; 1496 } 1497 1498 /* 1499 * Stop the scan if we filled up our array. 1500 */ 1501 if (info->fcount == REVOKE_GC_MAXFILES) 1502 return(-1); 1503 return(0); 1504 } 1505 1506 void 1507 unp_dispose(struct mbuf *m) 1508 { 1509 if (m) 1510 unp_scan(m, unp_discard, NULL); 1511 } 1512 1513 static int 1514 unp_listen(struct unpcb *unp, struct thread *td) 1515 { 1516 struct proc *p = td->td_proc; 1517 1518 KKASSERT(p); 1519 cru2x(p->p_ucred, &unp->unp_peercred); 1520 unp->unp_flags |= UNP_HAVEPCCACHED; 1521 return (0); 1522 } 1523 1524 static void 1525 unp_scan(struct mbuf *m0, void (*op)(struct file *, void *), void *data) 1526 { 1527 struct mbuf *m; 1528 struct file **rp; 1529 struct cmsghdr *cm; 1530 int i; 1531 int qfds; 1532 1533 while (m0) { 1534 for (m = m0; m; m = m->m_next) { 1535 if (m->m_type == MT_CONTROL && 1536 m->m_len >= sizeof(*cm)) { 1537 cm = mtod(m, struct cmsghdr *); 1538 if (cm->cmsg_level != SOL_SOCKET || 1539 cm->cmsg_type != SCM_RIGHTS) 1540 continue; 1541 qfds = (cm->cmsg_len - CMSG_LEN(0)) / 1542 sizeof(void *); 1543 rp = (struct file **)CMSG_DATA(cm); 1544 for (i = 0; i < qfds; i++) 1545 (*op)(*rp++, data); 1546 break; /* XXX, but saves time */ 1547 } 1548 } 1549 m0 = m0->m_nextpkt; 1550 } 1551 } 1552 1553 static void 1554 unp_mark(struct file *fp, void *data) 1555 { 1556 struct unp_gc_info *info = data; 1557 1558 if ((fp->f_flag & FMARK) == 0) { 1559 ++info->defer; 1560 atomic_set_int(&fp->f_flag, FMARK | FDEFER); 1561 } 1562 } 1563 1564 static void 1565 unp_discard(struct file *fp, void *data __unused) 1566 { 1567 spin_lock_wr(&unp_spin); 1568 fp->f_msgcount--; 1569 unp_rights--; 1570 spin_unlock_wr(&unp_spin); 1571 closef(fp, NULL); 1572 } 1573 1574