1 /* $OpenBSD: uipc_usrreq.c,v 1.123 2018/01/04 10:45:30 mpi Exp $ */ 2 /* $NetBSD: uipc_usrreq.c,v 1.18 1996/02/09 19:00:50 christos Exp $ */ 3 4 /* 5 * Copyright (c) 1982, 1986, 1989, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * @(#)uipc_usrreq.c 8.3 (Berkeley) 1/4/94 33 */ 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/proc.h> 38 #include <sys/filedesc.h> 39 #include <sys/domain.h> 40 #include <sys/protosw.h> 41 #include <sys/queue.h> 42 #include <sys/socket.h> 43 #include <sys/socketvar.h> 44 #include <sys/unpcb.h> 45 #include <sys/un.h> 46 #include <sys/namei.h> 47 #include <sys/vnode.h> 48 #include <sys/file.h> 49 #include <sys/stat.h> 50 #include <sys/mbuf.h> 51 #include <sys/task.h> 52 #include <sys/pledge.h> 53 54 void uipc_setaddr(const struct unpcb *, struct mbuf *); 55 56 /* list of all UNIX domain sockets, for unp_gc() */ 57 LIST_HEAD(unp_head, unpcb) unp_head = LIST_HEAD_INITIALIZER(unp_head); 58 59 /* 60 * Stack of sets of files that were passed over a socket but were 61 * not received and need to be closed. 62 */ 63 struct unp_deferral { 64 SLIST_ENTRY(unp_deferral) ud_link; 65 int ud_n; 66 /* followed by ud_n struct fdpass */ 67 struct fdpass ud_fp[]; 68 }; 69 70 void unp_discard(struct fdpass *, int); 71 void unp_mark(struct fdpass *, int); 72 void unp_scan(struct mbuf *, void (*)(struct fdpass *, int)); 73 int unp_nam2sun(struct mbuf *, struct sockaddr_un **, size_t *); 74 75 /* list of sets of files that were sent over sockets that are now closed */ 76 SLIST_HEAD(,unp_deferral) unp_deferred = SLIST_HEAD_INITIALIZER(unp_deferred); 77 78 struct task unp_gc_task = TASK_INITIALIZER(unp_gc, NULL); 79 80 81 /* 82 * Unix communications domain. 83 * 84 * TODO: 85 * RDM 86 * rethink name space problems 87 * need a proper out-of-band 88 */ 89 struct sockaddr sun_noname = { sizeof(sun_noname), AF_UNIX }; 90 ino_t unp_ino; /* prototype for fake inode numbers */ 91 92 void 93 uipc_setaddr(const struct unpcb *unp, struct mbuf *nam) 94 { 95 if (unp != NULL && unp->unp_addr != NULL) { 96 nam->m_len = unp->unp_addr->m_len; 97 memcpy(mtod(nam, caddr_t), mtod(unp->unp_addr, caddr_t), 98 nam->m_len); 99 } else { 100 nam->m_len = sizeof(sun_noname); 101 memcpy(mtod(nam, struct sockaddr *), &sun_noname, 102 nam->m_len); 103 } 104 } 105 106 int 107 uipc_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam, 108 struct mbuf *control, struct proc *p) 109 { 110 struct unpcb *unp = sotounpcb(so); 111 struct socket *so2; 112 int error = 0; 113 114 if (req == PRU_CONTROL) 115 return (EOPNOTSUPP); 116 if (req != PRU_SEND && control && control->m_len) { 117 error = EOPNOTSUPP; 118 goto release; 119 } 120 if (unp == NULL) { 121 error = EINVAL; 122 goto release; 123 } 124 125 NET_ASSERT_UNLOCKED(); 126 127 switch (req) { 128 129 case PRU_BIND: 130 error = unp_bind(unp, nam, p); 131 break; 132 133 case PRU_LISTEN: 134 if (unp->unp_vnode == NULL) 135 error = EINVAL; 136 break; 137 138 case PRU_CONNECT: 139 error = unp_connect(so, nam, p); 140 break; 141 142 case PRU_CONNECT2: 143 error = unp_connect2(so, (struct socket *)nam); 144 break; 145 146 case PRU_DISCONNECT: 147 unp_disconnect(unp); 148 break; 149 150 case PRU_ACCEPT: 151 /* 152 * Pass back name of connected socket, 153 * if it was bound and we are still connected 154 * (our peer may have closed already!). 155 */ 156 uipc_setaddr(unp->unp_conn, nam); 157 break; 158 159 case PRU_SHUTDOWN: 160 socantsendmore(so); 161 unp_shutdown(unp); 162 break; 163 164 case PRU_RCVD: 165 switch (so->so_type) { 166 167 case SOCK_DGRAM: 168 panic("uipc 1"); 169 /*NOTREACHED*/ 170 171 case SOCK_STREAM: 172 case SOCK_SEQPACKET: 173 if (unp->unp_conn == NULL) 174 break; 175 so2 = unp->unp_conn->unp_socket; 176 /* 177 * Adjust backpressure on sender 178 * and wakeup any waiting to write. 179 */ 180 so2->so_snd.sb_mbcnt = so->so_rcv.sb_mbcnt; 181 so2->so_snd.sb_cc = so->so_rcv.sb_cc; 182 sowwakeup(so2); 183 break; 184 185 default: 186 panic("uipc 2"); 187 } 188 break; 189 190 case PRU_SEND: 191 if (control && (error = unp_internalize(control, p))) 192 break; 193 switch (so->so_type) { 194 195 case SOCK_DGRAM: { 196 struct sockaddr *from; 197 198 if (nam) { 199 if (unp->unp_conn) { 200 error = EISCONN; 201 break; 202 } 203 error = unp_connect(so, nam, p); 204 if (error) 205 break; 206 } else { 207 if (unp->unp_conn == NULL) { 208 error = ENOTCONN; 209 break; 210 } 211 } 212 so2 = unp->unp_conn->unp_socket; 213 if (unp->unp_addr) 214 from = mtod(unp->unp_addr, struct sockaddr *); 215 else 216 from = &sun_noname; 217 if (sbappendaddr(so2, &so2->so_rcv, from, m, control)) { 218 sorwakeup(so2); 219 m = NULL; 220 control = NULL; 221 } else 222 error = ENOBUFS; 223 if (nam) 224 unp_disconnect(unp); 225 break; 226 } 227 228 case SOCK_STREAM: 229 case SOCK_SEQPACKET: 230 if (so->so_state & SS_CANTSENDMORE) { 231 error = EPIPE; 232 break; 233 } 234 if (unp->unp_conn == NULL) { 235 error = ENOTCONN; 236 break; 237 } 238 so2 = unp->unp_conn->unp_socket; 239 /* 240 * Send to paired receive port, and then raise 241 * send buffer counts to maintain backpressure. 242 * Wake up readers. 243 */ 244 if (control) { 245 if (sbappendcontrol(so2, &so2->so_rcv, m, 246 control)) { 247 control = NULL; 248 } else { 249 error = ENOBUFS; 250 break; 251 } 252 } else if (so->so_type == SOCK_SEQPACKET) 253 sbappendrecord(so2, &so2->so_rcv, m); 254 else 255 sbappend(so2, &so2->so_rcv, m); 256 so->so_snd.sb_mbcnt = so2->so_rcv.sb_mbcnt; 257 so->so_snd.sb_cc = so2->so_rcv.sb_cc; 258 sorwakeup(so2); 259 m = NULL; 260 break; 261 262 default: 263 panic("uipc 4"); 264 } 265 /* we need to undo unp_internalize in case of errors */ 266 if (control && error) 267 unp_dispose(control); 268 break; 269 270 case PRU_ABORT: 271 unp_drop(unp, ECONNABORTED); 272 break; 273 274 case PRU_SENSE: { 275 struct stat *sb = (struct stat *)m; 276 277 sb->st_blksize = so->so_snd.sb_hiwat; 278 sb->st_dev = NODEV; 279 if (unp->unp_ino == 0) 280 unp->unp_ino = unp_ino++; 281 sb->st_atim.tv_sec = 282 sb->st_mtim.tv_sec = 283 sb->st_ctim.tv_sec = unp->unp_ctime.tv_sec; 284 sb->st_atim.tv_nsec = 285 sb->st_mtim.tv_nsec = 286 sb->st_ctim.tv_nsec = unp->unp_ctime.tv_nsec; 287 sb->st_ino = unp->unp_ino; 288 return (0); 289 } 290 291 case PRU_RCVOOB: 292 return (EOPNOTSUPP); 293 294 case PRU_SENDOOB: 295 error = EOPNOTSUPP; 296 break; 297 298 case PRU_SOCKADDR: 299 uipc_setaddr(unp, nam); 300 break; 301 302 case PRU_PEERADDR: 303 uipc_setaddr(unp->unp_conn, nam); 304 break; 305 306 case PRU_SLOWTIMO: 307 break; 308 309 default: 310 panic("piusrreq"); 311 } 312 release: 313 m_freem(control); 314 m_freem(m); 315 return (error); 316 } 317 318 /* 319 * Both send and receive buffers are allocated PIPSIZ bytes of buffering 320 * for stream sockets, although the total for sender and receiver is 321 * actually only PIPSIZ. 322 * Datagram sockets really use the sendspace as the maximum datagram size, 323 * and don't really want to reserve the sendspace. Their recvspace should 324 * be large enough for at least one max-size datagram plus address. 325 */ 326 #define PIPSIZ 4096 327 u_long unpst_sendspace = PIPSIZ; 328 u_long unpst_recvspace = PIPSIZ; 329 u_long unpdg_sendspace = 2*1024; /* really max datagram size */ 330 u_long unpdg_recvspace = 4*1024; 331 332 int unp_rights; /* file descriptors in flight */ 333 334 int 335 uipc_attach(struct socket *so, int proto) 336 { 337 struct unpcb *unp; 338 int error; 339 340 if (so->so_pcb) 341 return EISCONN; 342 if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { 343 switch (so->so_type) { 344 345 case SOCK_STREAM: 346 case SOCK_SEQPACKET: 347 error = soreserve(so, unpst_sendspace, unpst_recvspace); 348 break; 349 350 case SOCK_DGRAM: 351 error = soreserve(so, unpdg_sendspace, unpdg_recvspace); 352 break; 353 354 default: 355 panic("unp_attach"); 356 } 357 if (error) 358 return (error); 359 } 360 unp = malloc(sizeof(*unp), M_PCB, M_NOWAIT|M_ZERO); 361 if (unp == NULL) 362 return (ENOBUFS); 363 unp->unp_socket = so; 364 so->so_pcb = unp; 365 getnanotime(&unp->unp_ctime); 366 LIST_INSERT_HEAD(&unp_head, unp, unp_link); 367 return (0); 368 } 369 370 int 371 uipc_detach(struct socket *so) 372 { 373 struct unpcb *unp = sotounpcb(so); 374 375 if (unp == NULL) 376 return (EINVAL); 377 378 NET_ASSERT_UNLOCKED(); 379 380 unp_detach(unp); 381 382 return (0); 383 } 384 385 void 386 unp_detach(struct unpcb *unp) 387 { 388 struct vnode *vp; 389 390 LIST_REMOVE(unp, unp_link); 391 if (unp->unp_vnode) { 392 unp->unp_vnode->v_socket = NULL; 393 vp = unp->unp_vnode; 394 unp->unp_vnode = NULL; 395 vrele(vp); 396 } 397 if (unp->unp_conn) 398 unp_disconnect(unp); 399 while (!SLIST_EMPTY(&unp->unp_refs)) 400 unp_drop(SLIST_FIRST(&unp->unp_refs), ECONNRESET); 401 soisdisconnected(unp->unp_socket); 402 unp->unp_socket->so_pcb = NULL; 403 m_freem(unp->unp_addr); 404 free(unp, M_PCB, sizeof *unp); 405 if (unp_rights) 406 task_add(systq, &unp_gc_task); 407 } 408 409 int 410 unp_bind(struct unpcb *unp, struct mbuf *nam, struct proc *p) 411 { 412 struct sockaddr_un *soun; 413 struct mbuf *nam2; 414 struct vnode *vp; 415 struct vattr vattr; 416 int error; 417 struct nameidata nd; 418 size_t pathlen; 419 420 if (unp->unp_vnode != NULL) 421 return (EINVAL); 422 if ((error = unp_nam2sun(nam, &soun, &pathlen))) 423 return (error); 424 425 nam2 = m_getclr(M_WAITOK, MT_SONAME); 426 nam2->m_len = sizeof(struct sockaddr_un); 427 memcpy(mtod(nam2, struct sockaddr_un *), soun, 428 offsetof(struct sockaddr_un, sun_path) + pathlen); 429 /* No need to NUL terminate: m_getclr() returns zero'd mbufs. */ 430 431 soun = mtod(nam2, struct sockaddr_un *); 432 433 /* Fixup sun_len to keep it in sync with m_len. */ 434 soun->sun_len = nam2->m_len; 435 436 NDINIT(&nd, CREATE, NOFOLLOW | LOCKPARENT, UIO_SYSSPACE, 437 soun->sun_path, p); 438 nd.ni_pledge = PLEDGE_UNIX; 439 /* SHOULD BE ABLE TO ADOPT EXISTING AND wakeup() ALA FIFO's */ 440 if ((error = namei(&nd)) != 0) { 441 m_freem(nam2); 442 return (error); 443 } 444 vp = nd.ni_vp; 445 if (vp != NULL) { 446 VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd); 447 if (nd.ni_dvp == vp) 448 vrele(nd.ni_dvp); 449 else 450 vput(nd.ni_dvp); 451 vrele(vp); 452 m_freem(nam2); 453 return (EADDRINUSE); 454 } 455 VATTR_NULL(&vattr); 456 vattr.va_type = VSOCK; 457 vattr.va_mode = ACCESSPERMS &~ p->p_fd->fd_cmask; 458 error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr); 459 if (error) { 460 m_freem(nam2); 461 return (error); 462 } 463 unp->unp_addr = nam2; 464 vp = nd.ni_vp; 465 vp->v_socket = unp->unp_socket; 466 unp->unp_vnode = vp; 467 unp->unp_connid.uid = p->p_ucred->cr_uid; 468 unp->unp_connid.gid = p->p_ucred->cr_gid; 469 unp->unp_connid.pid = p->p_p->ps_pid; 470 unp->unp_flags |= UNP_FEIDSBIND; 471 VOP_UNLOCK(vp, p); 472 return (0); 473 } 474 475 int 476 unp_connect(struct socket *so, struct mbuf *nam, struct proc *p) 477 { 478 struct sockaddr_un *soun; 479 struct vnode *vp; 480 struct socket *so2, *so3; 481 struct unpcb *unp, *unp2, *unp3; 482 struct nameidata nd; 483 int error; 484 485 if ((error = unp_nam2sun(nam, &soun, NULL))) 486 return (error); 487 488 NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, soun->sun_path, p); 489 nd.ni_pledge = PLEDGE_UNIX; 490 if ((error = namei(&nd)) != 0) 491 return (error); 492 vp = nd.ni_vp; 493 if (vp->v_type != VSOCK) { 494 error = ENOTSOCK; 495 goto bad; 496 } 497 if ((error = VOP_ACCESS(vp, VWRITE, p->p_ucred, p)) != 0) 498 goto bad; 499 so2 = vp->v_socket; 500 if (so2 == NULL) { 501 error = ECONNREFUSED; 502 goto bad; 503 } 504 if (so->so_type != so2->so_type) { 505 error = EPROTOTYPE; 506 goto bad; 507 } 508 if (so->so_proto->pr_flags & PR_CONNREQUIRED) { 509 if ((so2->so_options & SO_ACCEPTCONN) == 0 || 510 (so3 = sonewconn(so2, 0)) == 0) { 511 error = ECONNREFUSED; 512 goto bad; 513 } 514 unp = sotounpcb(so); 515 unp2 = sotounpcb(so2); 516 unp3 = sotounpcb(so3); 517 if (unp2->unp_addr) 518 unp3->unp_addr = 519 m_copym(unp2->unp_addr, 0, M_COPYALL, M_NOWAIT); 520 unp3->unp_connid.uid = p->p_ucred->cr_uid; 521 unp3->unp_connid.gid = p->p_ucred->cr_gid; 522 unp3->unp_connid.pid = p->p_p->ps_pid; 523 unp3->unp_flags |= UNP_FEIDS; 524 so2 = so3; 525 if (unp2->unp_flags & UNP_FEIDSBIND) { 526 unp->unp_connid = unp2->unp_connid; 527 unp->unp_flags |= UNP_FEIDS; 528 } 529 } 530 error = unp_connect2(so, so2); 531 bad: 532 vput(vp); 533 return (error); 534 } 535 536 int 537 unp_connect2(struct socket *so, struct socket *so2) 538 { 539 struct unpcb *unp = sotounpcb(so); 540 struct unpcb *unp2; 541 542 if (so2->so_type != so->so_type) 543 return (EPROTOTYPE); 544 unp2 = sotounpcb(so2); 545 unp->unp_conn = unp2; 546 switch (so->so_type) { 547 548 case SOCK_DGRAM: 549 SLIST_INSERT_HEAD(&unp2->unp_refs, unp, unp_nextref); 550 soisconnected(so); 551 break; 552 553 case SOCK_STREAM: 554 case SOCK_SEQPACKET: 555 unp2->unp_conn = unp; 556 soisconnected(so); 557 soisconnected(so2); 558 break; 559 560 default: 561 panic("unp_connect2"); 562 } 563 return (0); 564 } 565 566 void 567 unp_disconnect(struct unpcb *unp) 568 { 569 struct unpcb *unp2 = unp->unp_conn; 570 571 if (unp2 == NULL) 572 return; 573 unp->unp_conn = NULL; 574 switch (unp->unp_socket->so_type) { 575 576 case SOCK_DGRAM: 577 SLIST_REMOVE(&unp2->unp_refs, unp, unpcb, unp_nextref); 578 unp->unp_socket->so_state &= ~SS_ISCONNECTED; 579 break; 580 581 case SOCK_STREAM: 582 case SOCK_SEQPACKET: 583 unp->unp_socket->so_snd.sb_mbcnt = 0; 584 unp->unp_socket->so_snd.sb_cc = 0; 585 soisdisconnected(unp->unp_socket); 586 unp2->unp_conn = NULL; 587 unp2->unp_socket->so_snd.sb_mbcnt = 0; 588 unp2->unp_socket->so_snd.sb_cc = 0; 589 soisdisconnected(unp2->unp_socket); 590 break; 591 } 592 } 593 594 void 595 unp_shutdown(struct unpcb *unp) 596 { 597 struct socket *so; 598 599 switch (unp->unp_socket->so_type) { 600 case SOCK_STREAM: 601 case SOCK_SEQPACKET: 602 if (unp->unp_conn && (so = unp->unp_conn->unp_socket)) 603 socantrcvmore(so); 604 break; 605 default: 606 break; 607 } 608 } 609 610 void 611 unp_drop(struct unpcb *unp, int errno) 612 { 613 struct socket *so = unp->unp_socket; 614 615 so->so_error = errno; 616 unp_disconnect(unp); 617 if (so->so_head) { 618 so->so_pcb = NULL; 619 sofree(so); 620 m_freem(unp->unp_addr); 621 free(unp, M_PCB, sizeof *unp); 622 } 623 } 624 625 #ifdef notdef 626 unp_drain(void) 627 { 628 629 } 630 #endif 631 632 extern struct domain unixdomain; 633 634 static struct unpcb * 635 fptounp(struct file *fp) 636 { 637 struct socket *so; 638 639 if (fp->f_type != DTYPE_SOCKET) 640 return (NULL); 641 if ((so = fp->f_data) == NULL) 642 return (NULL); 643 if (so->so_proto->pr_domain != &unixdomain) 644 return (NULL); 645 return (sotounpcb(so)); 646 } 647 648 int 649 unp_externalize(struct mbuf *rights, socklen_t controllen, int flags) 650 { 651 struct proc *p = curproc; /* XXX */ 652 struct cmsghdr *cm = mtod(rights, struct cmsghdr *); 653 int i, *fdp = NULL; 654 struct fdpass *rp; 655 struct file *fp; 656 int nfds, error = 0; 657 658 nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) / 659 sizeof(struct fdpass); 660 if (controllen < CMSG_ALIGN(sizeof(struct cmsghdr))) 661 controllen = 0; 662 else 663 controllen -= CMSG_ALIGN(sizeof(struct cmsghdr)); 664 if (nfds > controllen / sizeof(int)) { 665 error = EMSGSIZE; 666 goto restart; 667 } 668 669 /* Make sure the recipient should be able to see the descriptors.. */ 670 rp = (struct fdpass *)CMSG_DATA(cm); 671 for (i = 0; i < nfds; i++) { 672 fp = rp->fp; 673 rp++; 674 error = pledge_recvfd(p, fp); 675 if (error) 676 break; 677 678 /* 679 * No to block devices. If passing a directory, 680 * make sure that it is underneath the root. 681 */ 682 if (p->p_fd->fd_rdir != NULL && fp->f_type == DTYPE_VNODE) { 683 struct vnode *vp = (struct vnode *)fp->f_data; 684 685 if (vp->v_type == VBLK || 686 (vp->v_type == VDIR && 687 !vn_isunder(vp, p->p_fd->fd_rdir, p))) { 688 error = EPERM; 689 break; 690 } 691 } 692 } 693 694 fdp = mallocarray(nfds, sizeof(int), M_TEMP, M_WAITOK); 695 696 restart: 697 fdplock(p->p_fd); 698 if (error != 0) { 699 if (nfds > 0) { 700 rp = ((struct fdpass *)CMSG_DATA(cm)); 701 unp_discard(rp, nfds); 702 } 703 goto out; 704 } 705 706 /* 707 * First loop -- allocate file descriptor table slots for the 708 * new descriptors. 709 */ 710 rp = ((struct fdpass *)CMSG_DATA(cm)); 711 for (i = 0; i < nfds; i++) { 712 if ((error = fdalloc(p, 0, &fdp[i])) != 0) { 713 /* 714 * Back out what we've done so far. 715 */ 716 for (--i; i >= 0; i--) 717 fdremove(p->p_fd, fdp[i]); 718 719 if (error == ENOSPC) { 720 fdexpand(p); 721 error = 0; 722 } else { 723 /* 724 * This is the error that has historically 725 * been returned, and some callers may 726 * expect it. 727 */ 728 error = EMSGSIZE; 729 } 730 fdpunlock(p->p_fd); 731 goto restart; 732 } 733 734 /* 735 * Make the slot reference the descriptor so that 736 * fdalloc() works properly.. We finalize it all 737 * in the loop below. 738 */ 739 p->p_fd->fd_ofiles[fdp[i]] = rp->fp; 740 p->p_fd->fd_ofileflags[fdp[i]] = (rp->flags & UF_PLEDGED); 741 rp++; 742 743 if (flags & MSG_CMSG_CLOEXEC) 744 p->p_fd->fd_ofileflags[fdp[i]] |= UF_EXCLOSE; 745 } 746 747 /* 748 * Now that adding them has succeeded, update all of the 749 * descriptor passing state. 750 */ 751 rp = (struct fdpass *)CMSG_DATA(cm); 752 for (i = 0; i < nfds; i++) { 753 struct unpcb *unp; 754 755 fp = rp->fp; 756 rp++; 757 if ((unp = fptounp(fp)) != NULL) 758 unp->unp_msgcount--; 759 unp_rights--; 760 } 761 762 /* 763 * Copy temporary array to message and adjust length, in case of 764 * transition from large struct file pointers to ints. 765 */ 766 memcpy(CMSG_DATA(cm), fdp, nfds * sizeof(int)); 767 cm->cmsg_len = CMSG_LEN(nfds * sizeof(int)); 768 rights->m_len = CMSG_LEN(nfds * sizeof(int)); 769 out: 770 fdpunlock(p->p_fd); 771 if (fdp) 772 free(fdp, M_TEMP, nfds * sizeof(int)); 773 return (error); 774 } 775 776 int 777 unp_internalize(struct mbuf *control, struct proc *p) 778 { 779 struct filedesc *fdp = p->p_fd; 780 struct cmsghdr *cm = mtod(control, struct cmsghdr *); 781 struct fdpass *rp; 782 struct file *fp; 783 struct unpcb *unp; 784 int i, error; 785 int nfds, *ip, fd, neededspace; 786 787 /* 788 * Check for two potential msg_controllen values because 789 * IETF stuck their nose in a place it does not belong. 790 */ 791 if (cm->cmsg_type != SCM_RIGHTS || cm->cmsg_level != SOL_SOCKET || 792 !(cm->cmsg_len == control->m_len || 793 control->m_len == CMSG_ALIGN(cm->cmsg_len))) 794 return (EINVAL); 795 nfds = (cm->cmsg_len - CMSG_ALIGN(sizeof(*cm))) / sizeof (int); 796 797 if (unp_rights + nfds > maxfiles / 10) 798 return (EMFILE); 799 800 /* Make sure we have room for the struct file pointers */ 801 morespace: 802 neededspace = CMSG_SPACE(nfds * sizeof(struct fdpass)) - 803 control->m_len; 804 if (neededspace > M_TRAILINGSPACE(control)) { 805 char *tmp; 806 /* if we already have a cluster, the message is just too big */ 807 if (control->m_flags & M_EXT) 808 return (E2BIG); 809 810 /* copy cmsg data temporarily out of the mbuf */ 811 tmp = malloc(control->m_len, M_TEMP, M_WAITOK); 812 memcpy(tmp, mtod(control, caddr_t), control->m_len); 813 814 /* allocate a cluster and try again */ 815 MCLGET(control, M_WAIT); 816 if ((control->m_flags & M_EXT) == 0) { 817 free(tmp, M_TEMP, control->m_len); 818 return (ENOBUFS); /* allocation failed */ 819 } 820 821 /* copy the data back into the cluster */ 822 cm = mtod(control, struct cmsghdr *); 823 memcpy(cm, tmp, control->m_len); 824 free(tmp, M_TEMP, control->m_len); 825 goto morespace; 826 } 827 828 /* adjust message & mbuf to note amount of space actually used. */ 829 cm->cmsg_len = CMSG_LEN(nfds * sizeof(struct fdpass)); 830 control->m_len = CMSG_SPACE(nfds * sizeof(struct fdpass)); 831 832 ip = ((int *)CMSG_DATA(cm)) + nfds - 1; 833 rp = ((struct fdpass *)CMSG_DATA(cm)) + nfds - 1; 834 for (i = 0; i < nfds; i++) { 835 memcpy(&fd, ip, sizeof fd); 836 ip--; 837 if ((fp = fd_getfile(fdp, fd)) == NULL) { 838 error = EBADF; 839 goto fail; 840 } 841 if (fp->f_count == LONG_MAX-2) { 842 error = EDEADLK; 843 goto fail; 844 } 845 error = pledge_sendfd(p, fp); 846 if (error) 847 goto fail; 848 849 /* kqueue descriptors cannot be copied */ 850 if (fp->f_type == DTYPE_KQUEUE) { 851 error = EINVAL; 852 goto fail; 853 } 854 rp->fp = fp; 855 rp->flags = fdp->fd_ofileflags[fd] & UF_PLEDGED; 856 rp--; 857 fp->f_count++; 858 if ((unp = fptounp(fp)) != NULL) { 859 unp->unp_file = fp; 860 unp->unp_msgcount++; 861 } 862 unp_rights++; 863 } 864 return (0); 865 fail: 866 /* Back out what we just did. */ 867 for ( ; i > 0; i--) { 868 rp++; 869 fp = rp->fp; 870 fp->f_count--; 871 if ((unp = fptounp(fp)) != NULL) 872 unp->unp_msgcount--; 873 unp_rights--; 874 } 875 876 return (error); 877 } 878 879 int unp_defer, unp_gcing; 880 881 void 882 unp_gc(void *arg __unused) 883 { 884 struct unp_deferral *defer; 885 struct file *fp; 886 struct socket *so; 887 struct unpcb *unp; 888 int nunref, i; 889 890 if (unp_gcing) 891 return; 892 unp_gcing = 1; 893 894 /* close any fds on the deferred list */ 895 while ((defer = SLIST_FIRST(&unp_deferred)) != NULL) { 896 SLIST_REMOVE_HEAD(&unp_deferred, ud_link); 897 for (i = 0; i < defer->ud_n; i++) { 898 fp = defer->ud_fp[i].fp; 899 if (fp == NULL) 900 continue; 901 FREF(fp); 902 if ((unp = fptounp(fp)) != NULL) 903 unp->unp_msgcount--; 904 unp_rights--; 905 (void) closef(fp, NULL); 906 } 907 free(defer, M_TEMP, sizeof(*defer) + 908 sizeof(struct fdpass) * defer->ud_n); 909 } 910 911 unp_defer = 0; 912 LIST_FOREACH(unp, &unp_head, unp_link) 913 unp->unp_flags &= ~(UNP_GCMARK | UNP_GCDEFER | UNP_GCDEAD); 914 do { 915 nunref = 0; 916 LIST_FOREACH(unp, &unp_head, unp_link) { 917 if (unp->unp_flags & UNP_GCDEFER) { 918 /* 919 * This socket is referenced by another 920 * socket which is known to be live, 921 * so it's certainly live. 922 */ 923 unp->unp_flags &= ~UNP_GCDEFER; 924 unp_defer--; 925 } else if (unp->unp_flags & UNP_GCMARK) { 926 /* marked as live in previous pass */ 927 continue; 928 } else if ((fp = unp->unp_file) == NULL) { 929 /* not being passed, so can't be in loop */ 930 } else if (fp->f_count == 0) { 931 /* 932 * Already being closed, let normal close 933 * path take its course 934 */ 935 } else { 936 /* 937 * Unreferenced by other sockets so far, 938 * so if all the references (f_count) are 939 * from passing (unp_msgcount) then this 940 * socket is prospectively dead 941 */ 942 if (fp->f_count == unp->unp_msgcount) { 943 nunref++; 944 unp->unp_flags |= UNP_GCDEAD; 945 continue; 946 } 947 } 948 949 /* 950 * This is the first time we've seen this socket on 951 * the mark pass and known it has a live reference, 952 * so mark it, then scan its receive buffer for 953 * sockets and note them as deferred (== referenced, 954 * but not yet marked). 955 */ 956 unp->unp_flags |= UNP_GCMARK; 957 958 so = unp->unp_socket; 959 unp_scan(so->so_rcv.sb_mb, unp_mark); 960 } 961 } while (unp_defer); 962 963 /* 964 * If there are any unreferenced sockets, then for each dispose 965 * of files in its receive buffer and then close it. 966 */ 967 if (nunref) { 968 LIST_FOREACH(unp, &unp_head, unp_link) { 969 if (unp->unp_flags & UNP_GCDEAD) 970 unp_scan(unp->unp_socket->so_rcv.sb_mb, 971 unp_discard); 972 } 973 } 974 unp_gcing = 0; 975 } 976 977 void 978 unp_dispose(struct mbuf *m) 979 { 980 981 if (m) 982 unp_scan(m, unp_discard); 983 } 984 985 void 986 unp_scan(struct mbuf *m0, void (*op)(struct fdpass *, int)) 987 { 988 struct mbuf *m; 989 struct fdpass *rp; 990 struct cmsghdr *cm; 991 int qfds; 992 993 while (m0) { 994 for (m = m0; m; m = m->m_next) { 995 if (m->m_type == MT_CONTROL && 996 m->m_len >= sizeof(*cm)) { 997 cm = mtod(m, struct cmsghdr *); 998 if (cm->cmsg_level != SOL_SOCKET || 999 cm->cmsg_type != SCM_RIGHTS) 1000 continue; 1001 qfds = (cm->cmsg_len - CMSG_ALIGN(sizeof *cm)) 1002 / sizeof(struct fdpass); 1003 if (qfds > 0) { 1004 rp = (struct fdpass *)CMSG_DATA(cm); 1005 op(rp, qfds); 1006 } 1007 break; /* XXX, but saves time */ 1008 } 1009 } 1010 m0 = m0->m_nextpkt; 1011 } 1012 } 1013 1014 void 1015 unp_mark(struct fdpass *rp, int nfds) 1016 { 1017 struct unpcb *unp; 1018 int i; 1019 1020 for (i = 0; i < nfds; i++) { 1021 if (rp[i].fp == NULL) 1022 continue; 1023 1024 unp = fptounp(rp[i].fp); 1025 if (unp == NULL) 1026 continue; 1027 1028 if (unp->unp_flags & (UNP_GCMARK|UNP_GCDEFER)) 1029 continue; 1030 1031 unp_defer++; 1032 unp->unp_flags |= UNP_GCDEFER; 1033 unp->unp_flags &= ~UNP_GCDEAD; 1034 } 1035 } 1036 1037 void 1038 unp_discard(struct fdpass *rp, int nfds) 1039 { 1040 struct unp_deferral *defer; 1041 1042 /* copy the file pointers to a deferral structure */ 1043 defer = malloc(sizeof(*defer) + sizeof(*rp) * nfds, M_TEMP, M_WAITOK); 1044 defer->ud_n = nfds; 1045 memcpy(&defer->ud_fp[0], rp, sizeof(*rp) * nfds); 1046 memset(rp, 0, sizeof(*rp) * nfds); 1047 SLIST_INSERT_HEAD(&unp_deferred, defer, ud_link); 1048 1049 task_add(systq, &unp_gc_task); 1050 } 1051 1052 int 1053 unp_nam2sun(struct mbuf *nam, struct sockaddr_un **sun, size_t *pathlen) 1054 { 1055 struct sockaddr *sa = mtod(nam, struct sockaddr *); 1056 size_t size, len; 1057 1058 if (nam->m_len < offsetof(struct sockaddr, sa_data)) 1059 return EINVAL; 1060 if (sa->sa_family != AF_UNIX) 1061 return EAFNOSUPPORT; 1062 if (sa->sa_len != nam->m_len) 1063 return EINVAL; 1064 if (sa->sa_len > sizeof(struct sockaddr_un)) 1065 return EINVAL; 1066 *sun = (struct sockaddr_un *)sa; 1067 1068 /* ensure that sun_path is NUL terminated and fits */ 1069 size = (*sun)->sun_len - offsetof(struct sockaddr_un, sun_path); 1070 len = strnlen((*sun)->sun_path, size); 1071 if (len == sizeof((*sun)->sun_path)) 1072 return EINVAL; 1073 if (len == size) { 1074 if (M_TRAILINGSPACE(nam) == 0) 1075 return EINVAL; 1076 nam->m_len++; 1077 (*sun)->sun_len++; 1078 (*sun)->sun_path[len] = '\0'; 1079 } 1080 if (pathlen != NULL) 1081 *pathlen = len; 1082 1083 return 0; 1084 } 1085