1 /* $OpenBSD: tftp-proxy.c,v 1.4 2012/08/19 23:21:24 deraadt Exp $ 2 * 3 * Copyright (c) 2005 DLS Internet Services 4 * Copyright (c) 2004, 2005 Camiel Dobbelaar, <cd@sentia.nl> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 #include <sys/ioctl.h> 31 #include <sys/param.h> 32 #include <sys/types.h> 33 #include <sys/socket.h> 34 #include <sys/uio.h> 35 36 #include <netinet/in.h> 37 #include <arpa/inet.h> 38 #include <arpa/tftp.h> 39 #include <net/if.h> 40 #include <net/pfvar.h> 41 #include <netdb.h> 42 43 #include <unistd.h> 44 #include <errno.h> 45 #include <err.h> 46 #include <pwd.h> 47 #include <stdio.h> 48 #include <syslog.h> 49 #include <string.h> 50 #include <stdlib.h> 51 #include <event.h> 52 53 #include "filter.h" 54 55 #define CHROOT_DIR "/var/empty" 56 #define NOPRIV_USER "proxy" 57 58 #define DEFTRANSWAIT 2 59 #define NTOP_BUFS 4 60 #define PKTSIZE SEGSIZE+4 61 62 const char *opcode(int); 63 const char *sock_ntop(struct sockaddr *); 64 static void usage(void); 65 66 struct proxy_listener { 67 struct event ev; 68 TAILQ_ENTRY(proxy_listener) entry; 69 int (*cmsg2dst)(struct cmsghdr *, struct sockaddr_storage *); 70 int s; 71 }; 72 73 void proxy_listen(const char *, const char *, int); 74 void proxy_listener_events(void); 75 int proxy_dst4(struct cmsghdr *, struct sockaddr_storage *); 76 int proxy_dst6(struct cmsghdr *, struct sockaddr_storage *); 77 void proxy_recv(int, short, void *); 78 79 struct fd_reply { 80 TAILQ_ENTRY(fd_reply) entry; 81 int fd; 82 }; 83 84 struct privproc { 85 struct event pop_ev; 86 struct event push_ev; 87 TAILQ_HEAD(, fd_reply) replies; 88 struct evbuffer *buf; 89 }; 90 91 void proxy_privproc(int, struct passwd *); 92 void privproc_push(int, short, void *); 93 void privproc_pop(int, short, void *); 94 95 void unprivproc_push(int, short, void *); 96 void unprivproc_pop(int, short, void *); 97 void unprivproc_timeout(int, short, void *); 98 99 char ntop_buf[NTOP_BUFS][INET6_ADDRSTRLEN]; 100 101 struct loggers { 102 void (*err)(int, const char *, ...); 103 void (*errx)(int, const char *, ...); 104 void (*warn)(const char *, ...); 105 void (*warnx)(const char *, ...); 106 void (*info)(const char *, ...); 107 }; 108 109 const struct loggers conslogger = { 110 err, 111 errx, 112 warn, 113 warnx, 114 warnx 115 }; 116 117 void syslog_err(int, const char *, ...); 118 void syslog_errx(int, const char *, ...); 119 void syslog_warn(const char *, ...); 120 void syslog_warnx(const char *, ...); 121 void syslog_info(const char *, ...); 122 void syslog_vstrerror(int, int, const char *, va_list); 123 124 const struct loggers syslogger = { 125 syslog_err, 126 syslog_errx, 127 syslog_warn, 128 syslog_warnx, 129 syslog_info, 130 }; 131 132 const struct loggers *logger = &conslogger; 133 134 #define lerr(_e, _f...) logger->err((_e), _f) 135 #define lerrx(_e, _f...) logger->errx((_e), _f) 136 #define lwarn(_f...) logger->warn(_f) 137 #define lwarnx(_f...) logger->warnx(_f) 138 #define linfo(_f...) logger->info(_f) 139 140 __dead void 141 usage(void) 142 { 143 extern char *__progname; 144 fprintf(stderr, "usage: %s [-46v] [-l addr] [-p port] [-w wait]", 145 __progname); 146 exit(1); 147 } 148 149 int debug = 0; 150 int verbose = 0; 151 struct timeval transwait = { DEFTRANSWAIT, 0 }; 152 153 int on = 1; 154 155 struct addr_pair { 156 struct sockaddr_storage src; 157 struct sockaddr_storage dst; 158 }; 159 160 struct proxy_request { 161 char buf[SEGSIZE_MAX + 4]; 162 size_t buflen; 163 164 struct addr_pair addrs; 165 166 struct event ev; 167 TAILQ_ENTRY(proxy_request) entry; 168 u_int32_t id; 169 }; 170 171 struct proxy_child { 172 TAILQ_HEAD(, proxy_request) fdrequests; 173 TAILQ_HEAD(, proxy_request) tmrequests; 174 struct event push_ev; 175 struct event pop_ev; 176 struct evbuffer *buf; 177 }; 178 179 struct proxy_child *child = NULL; 180 TAILQ_HEAD(, proxy_listener) proxy_listeners; 181 182 int 183 main(int argc, char *argv[]) 184 { 185 extern char *__progname; 186 187 int c; 188 const char *errstr; 189 190 struct passwd *pw; 191 192 char *addr = "localhost"; 193 char *port = "6969"; 194 int family = AF_UNSPEC; 195 196 int pair[2]; 197 198 while ((c = getopt(argc, argv, "46dvl:p:w:")) != -1) { 199 switch (c) { 200 case '4': 201 family = AF_INET; 202 break; 203 case '6': 204 family = AF_INET6; 205 break; 206 case 'd': 207 verbose = debug = 1; 208 break; 209 case 'l': 210 addr = optarg; 211 break; 212 case 'p': 213 port = optarg; 214 break; 215 case 'v': 216 verbose = 1; 217 break; 218 case 'w': 219 transwait.tv_sec = strtonum(optarg, 1, 30, &errstr); 220 if (errstr) 221 errx(1, "wait is %s", errstr); 222 break; 223 default: 224 usage(); 225 /* NOTREACHED */ 226 } 227 } 228 229 if (geteuid() != 0) 230 errx(1, "need root privileges"); 231 232 if (!debug && daemon(1, 0) == -1) 233 err(1, "daemon"); 234 235 if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) == -1) 236 lerr(1, "socketpair"); 237 238 pw = getpwnam(NOPRIV_USER); 239 if (pw == NULL) 240 lerrx(1, "no %s user", NOPRIV_USER); 241 242 switch (fork()) { 243 case -1: 244 lerr(1, "fork"); 245 246 case 0: 247 setproctitle("privproc"); 248 close(pair[1]); 249 proxy_privproc(pair[0], pw); 250 /* this never returns */ 251 252 default: 253 setproctitle("unprivproc"); 254 close(pair[0]); 255 break; 256 } 257 258 child = calloc(1, sizeof(*child)); 259 if (child == NULL) 260 lerr(1, "alloc(child)"); 261 262 child->buf = evbuffer_new(); 263 if (child->buf == NULL) 264 lerr(1, "child evbuffer"); 265 266 TAILQ_INIT(&child->fdrequests); 267 TAILQ_INIT(&child->tmrequests); 268 269 if (!debug) { 270 openlog(__progname, LOG_PID|LOG_NDELAY, LOG_DAEMON); 271 tzset(); 272 logger = &syslogger; 273 } 274 275 proxy_listen(addr, port, family); 276 277 /* open /dev/pf */ 278 init_filter(NULL, verbose); 279 280 /* revoke privs */ 281 pw = getpwnam(NOPRIV_USER); 282 if (!pw) 283 lerrx(1, "no such user %s", NOPRIV_USER); 284 285 if (chroot(CHROOT_DIR) == -1) 286 lerr(1, "chroot %s", CHROOT_DIR); 287 288 if (chdir("/") == -1) 289 lerr(1, "chdir %s", CHROOT_DIR); 290 291 if (setgroups(1, &pw->pw_gid) || 292 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) || 293 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid)) 294 err(1, "unable to revoke privs"); 295 296 event_init(); 297 298 proxy_listener_events(); 299 300 if (ioctl(pair[1], FIONBIO, &on) == -1) 301 lerr(1, "ioctl(FIONBIO)"); 302 303 event_set(&child->pop_ev, pair[1], EV_READ | EV_PERSIST, 304 unprivproc_pop, NULL); 305 event_set(&child->push_ev, pair[1], EV_WRITE, 306 unprivproc_push, NULL); 307 308 event_add(&child->pop_ev, NULL); 309 310 event_dispatch(); 311 312 return(0); 313 } 314 315 316 void 317 proxy_privproc(int s, struct passwd *pw) 318 { 319 extern char *__progname; 320 struct privproc p; 321 322 if (!debug) { 323 openlog(__progname, LOG_PID|LOG_NDELAY, LOG_DAEMON); 324 tzset(); 325 logger = &syslogger; 326 } 327 328 if (ioctl(s, FIONBIO, &on) == -1) 329 lerr(1, "ioctl(FIONBIO)"); 330 331 if (chroot(CHROOT_DIR) == -1) 332 lerr(1, "chroot to %s", CHROOT_DIR); 333 334 if (chdir("/") == -1) 335 lerr(1, "chdir to %s", CHROOT_DIR); 336 337 if (setgroups(1, &pw->pw_gid) || 338 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid)) 339 lerr(1, "unable to set group ids"); 340 341 TAILQ_INIT(&p.replies); 342 343 p.buf = evbuffer_new(); 344 if (p.buf == NULL) 345 err(1, "pop evbuffer_new"); 346 347 event_init(); 348 349 event_set(&p.pop_ev, s, EV_READ | EV_PERSIST, privproc_pop, &p); 350 event_set(&p.push_ev, s, EV_WRITE, privproc_push, &p); 351 352 event_add(&p.pop_ev, NULL); 353 354 event_dispatch(); 355 } 356 357 void 358 privproc_pop(int fd, short events, void *arg) 359 { 360 struct addr_pair req; 361 struct privproc *p = arg; 362 struct fd_reply *rep; 363 int add = 0; 364 365 switch (evbuffer_read(p->buf, fd, sizeof(req))) { 366 case 0: 367 lerrx(1, "unprivproc has gone"); 368 case -1: 369 switch (errno) { 370 case EAGAIN: 371 case EINTR: 372 return; 373 default: 374 lerr(1, "privproc_pop read"); 375 } 376 default: 377 break; 378 } 379 380 while (EVBUFFER_LENGTH(p->buf) >= sizeof(req)) { 381 evbuffer_remove(p->buf, &req, sizeof(req)); 382 383 /* do i really need to check this? */ 384 if (req.src.ss_family != req.dst.ss_family) 385 lerrx(1, "family mismatch"); 386 387 rep = calloc(1, sizeof(*rep)); 388 if (rep == NULL) 389 lerr(1, "reply calloc"); 390 391 rep->fd = socket(req.src.ss_family, SOCK_DGRAM, IPPROTO_UDP); 392 if (rep->fd == -1) 393 lerr(1, "privproc socket"); 394 395 if (ioctl(rep->fd, FIONBIO, &on) == -1) 396 err(1, "privproc ioctl(FIONBIO)"); 397 398 if (setsockopt(rep->fd, SOL_SOCKET, SO_BINDANY, 399 &on, sizeof(on)) == -1) 400 lerr(1, "privproc setsockopt(BINDANY)"); 401 402 if (setsockopt(rep->fd, SOL_SOCKET, SO_REUSEADDR, 403 &on, sizeof(on)) == -1) 404 lerr(1, "privproc setsockopt(REUSEADDR)"); 405 406 if (setsockopt(rep->fd, SOL_SOCKET, SO_REUSEPORT, 407 &on, sizeof(on)) == -1) 408 lerr(1, "privproc setsockopt(REUSEPORT)"); 409 410 if (bind(rep->fd, (struct sockaddr *)&req.src, 411 req.src.ss_len) == -1) 412 lerr(1, "privproc bind"); 413 414 if (TAILQ_EMPTY(&p->replies)) 415 add = 1; 416 417 TAILQ_INSERT_TAIL(&p->replies, rep, entry); 418 } 419 420 if (add) 421 event_add(&p->push_ev, NULL); 422 } 423 424 void 425 privproc_push(int fd, short events, void *arg) 426 { 427 struct privproc *p = arg; 428 struct fd_reply *rep; 429 430 struct msghdr msg; 431 union { 432 struct cmsghdr hdr; 433 char buf[CMSG_SPACE(sizeof(int))]; 434 } cmsgbuf; 435 struct cmsghdr *cmsg; 436 struct iovec iov; 437 int result = 0; 438 439 while ((rep = TAILQ_FIRST(&p->replies)) != NULL) { 440 memset(&msg, 0, sizeof(msg)); 441 442 msg.msg_control = (caddr_t)&cmsgbuf.buf; 443 msg.msg_controllen = sizeof(cmsgbuf.buf); 444 cmsg = CMSG_FIRSTHDR(&msg); 445 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 446 cmsg->cmsg_level = SOL_SOCKET; 447 cmsg->cmsg_type = SCM_RIGHTS; 448 *(int *)CMSG_DATA(cmsg) = rep->fd; 449 450 iov.iov_base = &result; 451 iov.iov_len = sizeof(int); 452 msg.msg_iov = &iov; 453 msg.msg_iovlen = 1; 454 455 switch (sendmsg(fd, &msg, 0)) { 456 case sizeof(int): 457 break; 458 459 case -1: 460 if (errno == EAGAIN) 461 goto again; 462 463 lerr(1, "privproc sendmsg"); 464 /* NOTREACHED */ 465 466 default: 467 lerrx(1, "privproc sendmsg weird len"); 468 } 469 470 TAILQ_REMOVE(&p->replies, rep, entry); 471 close(rep->fd); 472 free(rep); 473 } 474 475 if (TAILQ_EMPTY(&p->replies)) 476 return; 477 478 again: 479 event_add(&p->push_ev, NULL); 480 } 481 482 void 483 proxy_listen(const char *addr, const char *port, int family) 484 { 485 struct proxy_listener *l; 486 487 struct addrinfo hints, *res, *res0; 488 int error; 489 int s, on = 1; 490 int serrno; 491 const char *cause = NULL; 492 493 memset(&hints, 0, sizeof(hints)); 494 hints.ai_family = family; 495 hints.ai_socktype = SOCK_DGRAM; 496 hints.ai_flags = AI_PASSIVE; 497 498 TAILQ_INIT(&proxy_listeners); 499 500 error = getaddrinfo(addr, port, &hints, &res0); 501 if (error) 502 errx(1, "%s:%s: %s", addr, port, gai_strerror(error)); 503 504 for (res = res0; res != NULL; res = res->ai_next) { 505 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol); 506 if (s == -1) { 507 cause = "socket"; 508 continue; 509 } 510 511 if (bind(s, res->ai_addr, res->ai_addrlen) == -1) { 512 cause = "bind"; 513 serrno = errno; 514 close(s); 515 errno = serrno; 516 continue; 517 } 518 519 l = calloc(1, sizeof(*l)); 520 if (l == NULL) 521 err(1, "listener alloc"); 522 523 if (ioctl(s, FIONBIO, &on) == -1) 524 err(1, "ioctl(FIONBIO)"); 525 526 switch (res->ai_family) { 527 case AF_INET: 528 l->cmsg2dst = proxy_dst4; 529 530 if (setsockopt(s, IPPROTO_IP, IP_RECVDSTADDR, 531 &on, sizeof(on)) == -1) 532 errx(1, "setsockopt(IP_RECVDSTADDR)"); 533 if (setsockopt(s, IPPROTO_IP, IP_RECVDSTPORT, 534 &on, sizeof(on)) == -1) 535 errx(1, "setsockopt(IP_RECVDSTPORT)"); 536 break; 537 case AF_INET6: 538 l->cmsg2dst = proxy_dst6; 539 540 if (setsockopt(s, IPPROTO_IPV6, IPV6_RECVPKTINFO, 541 &on, sizeof(on)) == -1) 542 errx(1, "setsockopt(IPV6_RECVPKTINFO)"); 543 break; 544 } 545 l->s = s; 546 547 TAILQ_INSERT_TAIL(&proxy_listeners, l, entry); 548 } 549 550 if (TAILQ_EMPTY(&proxy_listeners)) 551 err(1, "%s", cause); 552 } 553 554 void 555 proxy_listener_events(void) 556 { 557 struct proxy_listener *l; 558 559 TAILQ_FOREACH(l, &proxy_listeners, entry) { 560 event_set(&l->ev, l->s, EV_READ | EV_PERSIST, proxy_recv, l); 561 event_add(&l->ev, NULL); 562 } 563 } 564 565 char safety[SEGSIZE_MAX + 4]; 566 567 int 568 proxy_dst4(struct cmsghdr *cmsg, struct sockaddr_storage *ss) 569 { 570 struct sockaddr_in *sin = (struct sockaddr_in *)ss; 571 572 if (cmsg->cmsg_level != IPPROTO_IP) 573 return (0); 574 575 switch (cmsg->cmsg_type) { 576 case IP_RECVDSTADDR: 577 memcpy(&sin->sin_addr, CMSG_DATA(cmsg), sizeof(sin->sin_addr)); 578 if (sin->sin_addr.s_addr == INADDR_BROADCAST) 579 return (-1); 580 break; 581 582 case IP_RECVDSTPORT: 583 memcpy(&sin->sin_port, CMSG_DATA(cmsg), sizeof(sin->sin_port)); 584 break; 585 } 586 587 return (0); 588 } 589 590 int 591 proxy_dst6(struct cmsghdr *cmsg, struct sockaddr_storage *ss) 592 { 593 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ss; 594 struct in6_pktinfo *ipi = (struct in6_pktinfo *)CMSG_DATA(cmsg); 595 596 if (cmsg->cmsg_level != IPPROTO_IPV6) 597 return (0); 598 599 switch (cmsg->cmsg_type) { 600 case IPV6_PKTINFO: 601 memcpy(&sin6->sin6_addr, &ipi->ipi6_addr, 602 sizeof(sin6->sin6_addr)); 603 #ifdef __KAME__ 604 if (IN6_IS_ADDR_LINKLOCAL(&ipi->ipi6_addr)) 605 sin6->sin6_scope_id = ipi->ipi6_ifindex; 606 #endif 607 break; 608 609 /* XXX PORT */ 610 } 611 612 return (0); 613 } 614 615 void 616 proxy_recv(int fd, short events, void *arg) 617 { 618 struct proxy_listener *l = arg; 619 620 union { 621 struct cmsghdr hdr; 622 char buf[CMSG_SPACE(sizeof(struct sockaddr_storage)) + 623 CMSG_SPACE(sizeof(in_port_t))]; 624 } cmsgbuf; 625 struct cmsghdr *cmsg; 626 struct msghdr msg; 627 struct iovec iov; 628 ssize_t n; 629 630 struct proxy_request *r; 631 struct tftphdr *tp; 632 633 r = calloc(1, sizeof(*r)); 634 if (r == NULL) { 635 recv(fd, safety, sizeof(safety), 0); 636 return; 637 } 638 r->id = arc4random(); /* XXX unique? */ 639 640 bzero(&msg, sizeof(msg)); 641 iov.iov_base = r->buf; 642 iov.iov_len = sizeof(r->buf); 643 msg.msg_name = &r->addrs.src; 644 msg.msg_namelen = sizeof(r->addrs.src); 645 msg.msg_iov = &iov; 646 msg.msg_iovlen = 1; 647 msg.msg_control = &cmsgbuf.buf; 648 msg.msg_controllen = sizeof(cmsgbuf.buf); 649 650 n = recvmsg(fd, &msg, 0); 651 if (n == -1) { 652 switch (errno) { 653 case EAGAIN: 654 case EINTR: 655 goto err; 656 default: 657 lerr(1, "recvmsg"); 658 /* NOTREACHED */ 659 } 660 } 661 r->buflen = n; 662 663 /* check the packet */ 664 if (n < 5) { 665 /* not enough to be a real packet */ 666 goto err; 667 } 668 tp = (struct tftphdr *)r->buf; 669 switch (ntohs(tp->th_opcode)) { 670 case RRQ: 671 case WRQ: 672 break; 673 default: 674 goto err; 675 } 676 677 r->addrs.dst.ss_family = r->addrs.src.ss_family; 678 r->addrs.dst.ss_len = r->addrs.src.ss_len; 679 680 /* get local address if possible */ 681 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; 682 cmsg = CMSG_NXTHDR(&msg, cmsg)) { 683 if (l->cmsg2dst(cmsg, &r->addrs.dst) == -1) 684 goto err; 685 } 686 687 if (verbose) { 688 linfo("%s:%d -> %s:%d \"%s %s\"", 689 sock_ntop((struct sockaddr *)&r->addrs.src), 690 ntohs(((struct sockaddr_in *)&r->addrs.src)->sin_port), 691 sock_ntop((struct sockaddr *)&r->addrs.dst), 692 ntohs(((struct sockaddr_in *)&r->addrs.dst)->sin_port), 693 opcode(ntohs(tp->th_opcode)), tp->th_stuff); 694 /* XXX tp->th_stuff could be garbage */ 695 } 696 697 TAILQ_INSERT_TAIL(&child->fdrequests, r, entry); 698 evbuffer_add(child->buf, &r->addrs, sizeof(r->addrs)); 699 event_add(&child->push_ev, NULL); 700 701 return; 702 703 err: 704 free(r); 705 } 706 707 void 708 unprivproc_push(int fd, short events, void *arg) 709 { 710 if (evbuffer_write(child->buf, fd) == -1) 711 lerr(1, "child evbuffer_write"); 712 713 if (EVBUFFER_LENGTH(child->buf)) 714 event_add(&child->push_ev, NULL); 715 } 716 717 void 718 unprivproc_pop(int fd, short events, void *arg) 719 { 720 struct proxy_request *r; 721 722 struct msghdr msg; 723 union { 724 struct cmsghdr hdr; 725 char buf[CMSG_SPACE(sizeof(int))]; 726 } cmsgbuf; 727 struct cmsghdr *cmsg; 728 struct iovec iov; 729 int result; 730 int s; 731 732 do { 733 memset(&msg, 0, sizeof(msg)); 734 iov.iov_base = &result; 735 iov.iov_len = sizeof(int); 736 msg.msg_iov = &iov; 737 msg.msg_iovlen = 1; 738 msg.msg_control = &cmsgbuf.buf; 739 msg.msg_controllen = sizeof(cmsgbuf.buf); 740 741 switch (recvmsg(fd, &msg, 0)) { 742 case sizeof(int): 743 break; 744 745 case -1: 746 switch (errno) { 747 case EAGAIN: 748 case EINTR: 749 return; 750 default: 751 lerr(1, "child recvmsg"); 752 } 753 /* NOTREACHED */ 754 755 case 0: 756 lerrx(1, "privproc closed connection"); 757 758 default: 759 lerrx(1, "child recvmsg was weird"); 760 /* NOTREACHED */ 761 } 762 763 if (result != 0) { 764 errno = result; 765 lerr(1, "child fdpass fail"); 766 } 767 768 cmsg = CMSG_FIRSTHDR(&msg); 769 if (cmsg == NULL) 770 lerrx(1, "%s: no message header", __func__); 771 772 if (cmsg->cmsg_type != SCM_RIGHTS) { 773 lerrx(1, "%s: expected type %d got %d", __func__, 774 SCM_RIGHTS, cmsg->cmsg_type); 775 } 776 777 s = (*(int *)CMSG_DATA(cmsg)); 778 779 r = TAILQ_FIRST(&child->fdrequests); 780 if (r == NULL) 781 lerrx(1, "got fd without a pending request"); 782 783 TAILQ_REMOVE(&child->fdrequests, r, entry); 784 785 /* get ready to add rules */ 786 if (prepare_commit(r->id) == -1) 787 lerr(1, "%s: prepare_commit", __func__); 788 789 if (add_filter(r->id, PF_IN, (struct sockaddr *)&r->addrs.dst, 790 (struct sockaddr *)&r->addrs.src, 791 ntohs(((struct sockaddr_in *)&r->addrs.src)->sin_port), 792 IPPROTO_UDP) == -1) 793 lerr(1, "%s: couldn't add pass in", __func__); 794 795 if (add_filter(r->id, PF_OUT, (struct sockaddr *)&r->addrs.dst, 796 (struct sockaddr *)&r->addrs.src, 797 ntohs(((struct sockaddr_in *)&r->addrs.src)->sin_port), 798 IPPROTO_UDP) == -1) 799 lerr(1, "%s: couldn't add pass out", __func__); 800 801 if (do_commit() == -1) 802 lerr(1, "%s: couldn't commit rules", __func__); 803 804 /* forward the initial tftp request and start the insanity */ 805 if (sendto(s, r->buf, r->buflen, 0, 806 (struct sockaddr *)&r->addrs.dst, 807 r->addrs.dst.ss_len) == -1) 808 lerr(1, "%s: unable to send", __func__); 809 810 close(s); 811 812 evtimer_set(&r->ev, unprivproc_timeout, r); 813 evtimer_add(&r->ev, &transwait); 814 815 TAILQ_INSERT_TAIL(&child->tmrequests, r, entry); 816 } while (!TAILQ_EMPTY(&child->fdrequests)); 817 } 818 819 void 820 unprivproc_timeout(int fd, short events, void *arg) 821 { 822 struct proxy_request *r = arg; 823 824 TAILQ_REMOVE(&child->tmrequests, r, entry); 825 826 /* delete our rdr rule and clean up */ 827 prepare_commit(r->id); 828 do_commit(); 829 830 free(r); 831 } 832 833 834 const char * 835 opcode(int code) 836 { 837 static char str[6]; 838 839 switch (code) { 840 case 1: 841 (void)snprintf(str, sizeof(str), "RRQ"); 842 break; 843 case 2: 844 (void)snprintf(str, sizeof(str), "WRQ"); 845 break; 846 default: 847 (void)snprintf(str, sizeof(str), "(%d)", code); 848 break; 849 } 850 851 return (str); 852 } 853 854 const char * 855 sock_ntop(struct sockaddr *sa) 856 { 857 static int n = 0; 858 859 /* Cycle to next buffer. */ 860 n = (n + 1) % NTOP_BUFS; 861 ntop_buf[n][0] = '\0'; 862 863 if (sa->sa_family == AF_INET) { 864 struct sockaddr_in *sin = (struct sockaddr_in *)sa; 865 866 return (inet_ntop(AF_INET, &sin->sin_addr, ntop_buf[n], 867 sizeof ntop_buf[0])); 868 } 869 870 if (sa->sa_family == AF_INET6) { 871 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa; 872 873 return (inet_ntop(AF_INET6, &sin6->sin6_addr, ntop_buf[n], 874 sizeof ntop_buf[0])); 875 } 876 877 return (NULL); 878 } 879 880 void 881 syslog_vstrerror(int e, int priority, const char *fmt, va_list ap) 882 { 883 char *s; 884 885 if (vasprintf(&s, fmt, ap) == -1) { 886 syslog(LOG_EMERG, "unable to alloc in syslog_vstrerror"); 887 exit(1); 888 } 889 890 syslog(priority, "%s: %s", s, strerror(e)); 891 892 free(s); 893 } 894 895 void 896 syslog_err(int ecode, const char *fmt, ...) 897 { 898 va_list ap; 899 900 va_start(ap, fmt); 901 syslog_vstrerror(errno, LOG_EMERG, fmt, ap); 902 va_end(ap); 903 904 exit(ecode); 905 } 906 907 void 908 syslog_errx(int ecode, const char *fmt, ...) 909 { 910 va_list ap; 911 912 va_start(ap, fmt); 913 vsyslog(LOG_WARNING, fmt, ap); 914 va_end(ap); 915 916 exit(ecode); 917 } 918 919 void 920 syslog_warn(const char *fmt, ...) 921 { 922 va_list ap; 923 924 va_start(ap, fmt); 925 syslog_vstrerror(errno, LOG_WARNING, fmt, ap); 926 va_end(ap); 927 } 928 929 void 930 syslog_warnx(const char *fmt, ...) 931 { 932 va_list ap; 933 934 va_start(ap, fmt); 935 vsyslog(LOG_WARNING, fmt, ap); 936 va_end(ap); 937 } 938 939 void 940 syslog_info(const char *fmt, ...) 941 { 942 va_list ap; 943 944 va_start(ap, fmt); 945 vsyslog(LOG_INFO, fmt, ap); 946 va_end(ap); 947 } 948 949