1 /* $OpenBSD: netcat.c,v 1.126 2014/10/30 16:08:31 tedu Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj (at) monkey.org> 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 * 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /* 30 * Re-written nc(1) for OpenBSD. Original implementation by 31 * *Hobbit* <hobbit (at) avian.org>. 32 */ 33 34 #include "includes.h" 35 36 #include <sys/types.h> 37 #include <sys/socket.h> 38 #include <sys/time.h> 39 #include <sys/uio.h> 40 #include <sys/un.h> 41 42 #include <netinet/in.h> 43 #include <netinet/tcp.h> 44 #include <netinet/ip.h> 45 46 #include <errno.h> 47 #include <netdb.h> 48 #include <stdarg.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 #include <fcntl.h> 54 #include <limits.h> 55 #include "atomicio.h" 56 57 #ifdef HAVE_POLL_H 58 #include <poll.h> 59 #else 60 # ifdef HAVE_SYS_POLL_H 61 # include <sys/poll.h> 62 # endif 63 #endif 64 #ifdef HAVE_ERR_H 65 # include <err.h> 66 #endif 67 68 /* Telnet options from arpa/telnet.h */ 69 #define IAC 255 70 #define DONT 254 71 #define DO 253 72 #define WONT 252 73 #define WILL 251 74 75 #ifndef SUN_LEN 76 #define SUN_LEN(su) \ 77 (sizeof(*(su)) - sizeof((su)->sun_path) + strlen((su)->sun_path)) 78 #endif 79 80 #define PORT_MAX 65535 81 #define PORT_MAX_LEN 6 82 #define UNIX_DG_TMP_SOCKET_SIZE 19 83 84 #define POLL_STDIN 0 85 #define POLL_NETOUT 1 86 #define POLL_NETIN 2 87 #define POLL_STDOUT 3 88 #define BUFSIZE 16384 89 90 /* Command Line Options */ 91 int dflag; /* detached, no stdin */ 92 int Fflag; /* fdpass sock to stdout */ 93 unsigned int iflag; /* Interval Flag */ 94 int kflag; /* More than one connect */ 95 int lflag; /* Bind to local port */ 96 int Nflag; /* shutdown() network socket */ 97 int nflag; /* Don't do name look up */ 98 char *Pflag; /* Proxy username */ 99 char *pflag; /* Localport flag */ 100 int rflag; /* Random ports flag */ 101 char *sflag; /* Source Address */ 102 int tflag; /* Telnet Emulation */ 103 int uflag; /* UDP - Default to TCP */ 104 int vflag; /* Verbosity */ 105 int xflag; /* Socks proxy */ 106 int zflag; /* Port Scan Flag */ 107 int Dflag; /* sodebug */ 108 int Iflag; /* TCP receive buffer size */ 109 int Oflag; /* TCP send buffer size */ 110 int Sflag; /* TCP MD5 signature option */ 111 int Tflag = -1; /* IP Type of Service */ 112 int rtableid = -1; 113 114 int timeout = -1; 115 int family = AF_UNSPEC; 116 char *portlist[PORT_MAX+1]; 117 char *unix_dg_tmp_socket; 118 119 void atelnet(int, unsigned char *, unsigned int); 120 void build_ports(char *); 121 void help(void); 122 int local_listen(char *, char *, struct addrinfo); 123 void readwrite(int); 124 void fdpass(int nfd) __attribute__((noreturn)); 125 int remote_connect(const char *, const char *, struct addrinfo); 126 int timeout_connect(int, const struct sockaddr *, socklen_t); 127 int socks_connect(const char *, const char *, struct addrinfo, 128 const char *, const char *, struct addrinfo, int, const char *); 129 int udptest(int); 130 int unix_bind(char *); 131 int unix_connect(char *); 132 int unix_listen(char *); 133 void set_common_sockopts(int); 134 int map_tos(char *, int *); 135 void report_connect(const struct sockaddr *, socklen_t); 136 void usage(int); 137 ssize_t drainbuf(int, unsigned char *, size_t *); 138 ssize_t fillbuf(int, unsigned char *, size_t *); 139 140 141 int 142 main(int argc, char *argv[]) 143 { 144 int ch, s, ret, socksv; 145 char *host, *uport; 146 struct addrinfo hints; 147 struct servent *sv; 148 socklen_t len; 149 struct sockaddr_storage cliaddr; 150 char *proxy = NULL; 151 const char *errstr, *proxyhost = "", *proxyport = NULL; 152 struct addrinfo proxyhints; 153 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 154 155 ret = 1; 156 s = 0; 157 socksv = 5; 158 host = NULL; 159 uport = NULL; 160 sv = NULL; 161 162 while ((ch = getopt(argc, argv, 163 "46DdFhI:i:klNnO:P:p:rSs:tT:UuV:vw:X:x:z")) != -1) { 164 switch (ch) { 165 case '4': 166 family = AF_INET; 167 break; 168 case '6': 169 family = AF_INET6; 170 break; 171 case 'U': 172 family = AF_UNIX; 173 break; 174 case 'X': 175 if (strcasecmp(optarg, "connect") == 0) 176 socksv = -1; /* HTTP proxy CONNECT */ 177 else if (strcmp(optarg, "4") == 0) 178 socksv = 4; /* SOCKS v.4 */ 179 else if (strcmp(optarg, "5") == 0) 180 socksv = 5; /* SOCKS v.5 */ 181 else 182 errx(1, "unsupported proxy protocol"); 183 break; 184 case 'd': 185 dflag = 1; 186 break; 187 case 'F': 188 Fflag = 1; 189 break; 190 case 'h': 191 help(); 192 break; 193 case 'i': 194 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 195 if (errstr) 196 errx(1, "interval %s: %s", errstr, optarg); 197 break; 198 case 'k': 199 kflag = 1; 200 break; 201 case 'l': 202 lflag = 1; 203 break; 204 case 'N': 205 Nflag = 1; 206 break; 207 case 'n': 208 nflag = 1; 209 break; 210 case 'P': 211 Pflag = optarg; 212 break; 213 case 'p': 214 pflag = optarg; 215 break; 216 case 'r': 217 rflag = 1; 218 break; 219 case 's': 220 sflag = optarg; 221 break; 222 case 't': 223 tflag = 1; 224 break; 225 case 'u': 226 uflag = 1; 227 break; 228 #ifdef SO_RTABLE 229 case 'V': 230 rtableid = (int)strtonum(optarg, 0, 231 RT_TABLEID_MAX, &errstr); 232 if (errstr) 233 errx(1, "rtable %s: %s", errstr, optarg); 234 break; 235 #endif 236 case 'v': 237 vflag = 1; 238 break; 239 case 'w': 240 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 241 if (errstr) 242 errx(1, "timeout %s: %s", errstr, optarg); 243 timeout *= 1000; 244 break; 245 case 'x': 246 xflag = 1; 247 if ((proxy = strdup(optarg)) == NULL) 248 errx(1, "strdup"); 249 break; 250 case 'z': 251 zflag = 1; 252 break; 253 case 'D': 254 Dflag = 1; 255 break; 256 case 'I': 257 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 258 if (errstr != NULL) 259 errx(1, "TCP receive window %s: %s", 260 errstr, optarg); 261 break; 262 case 'O': 263 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 264 if (errstr != NULL) 265 errx(1, "TCP send window %s: %s", 266 errstr, optarg); 267 break; 268 case 'S': 269 Sflag = 1; 270 break; 271 case 'T': 272 errstr = NULL; 273 errno = 0; 274 if (map_tos(optarg, &Tflag)) 275 break; 276 if (strlen(optarg) > 1 && optarg[0] == '0' && 277 optarg[1] == 'x') 278 Tflag = (int)strtol(optarg, NULL, 16); 279 else 280 Tflag = (int)strtonum(optarg, 0, 255, 281 &errstr); 282 if (Tflag < 0 || Tflag > 255 || errstr || errno) 283 errx(1, "illegal tos value %s", optarg); 284 break; 285 default: 286 usage(1); 287 } 288 } 289 argc -= optind; 290 argv += optind; 291 292 /* Cruft to make sure options are clean, and used properly. */ 293 if (argv[0] && !argv[1] && family == AF_UNIX) { 294 host = argv[0]; 295 uport = NULL; 296 } else if (argv[0] && !argv[1]) { 297 if (!lflag) 298 usage(1); 299 uport = argv[0]; 300 host = NULL; 301 } else if (argv[0] && argv[1]) { 302 host = argv[0]; 303 uport = argv[1]; 304 } else 305 usage(1); 306 307 if (lflag && sflag) 308 errx(1, "cannot use -s and -l"); 309 if (lflag && pflag) 310 errx(1, "cannot use -p and -l"); 311 if (lflag && zflag) 312 errx(1, "cannot use -z and -l"); 313 if (!lflag && kflag) 314 errx(1, "must use -l with -k"); 315 316 /* Get name of temporary socket for unix datagram client */ 317 if ((family == AF_UNIX) && uflag && !lflag) { 318 if (sflag) { 319 unix_dg_tmp_socket = sflag; 320 } else { 321 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 322 UNIX_DG_TMP_SOCKET_SIZE); 323 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 324 err(1, "mktemp"); 325 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 326 } 327 } 328 329 /* Initialize addrinfo structure. */ 330 if (family != AF_UNIX) { 331 memset(&hints, 0, sizeof(struct addrinfo)); 332 hints.ai_family = family; 333 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 334 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 335 if (nflag) 336 hints.ai_flags |= AI_NUMERICHOST; 337 } 338 339 if (xflag) { 340 if (uflag) 341 errx(1, "no proxy support for UDP mode"); 342 343 if (lflag) 344 errx(1, "no proxy support for listen"); 345 346 if (family == AF_UNIX) 347 errx(1, "no proxy support for unix sockets"); 348 349 /* XXX IPv6 transport to proxy would probably work */ 350 if (family == AF_INET6) 351 errx(1, "no proxy support for IPv6"); 352 353 if (sflag) 354 errx(1, "no proxy support for local source address"); 355 356 proxyhost = strsep(&proxy, ":"); 357 proxyport = proxy; 358 359 memset(&proxyhints, 0, sizeof(struct addrinfo)); 360 proxyhints.ai_family = family; 361 proxyhints.ai_socktype = SOCK_STREAM; 362 proxyhints.ai_protocol = IPPROTO_TCP; 363 if (nflag) 364 proxyhints.ai_flags |= AI_NUMERICHOST; 365 } 366 367 if (lflag) { 368 int connfd; 369 ret = 0; 370 371 if (family == AF_UNIX) { 372 if (uflag) 373 s = unix_bind(host); 374 else 375 s = unix_listen(host); 376 } 377 378 /* Allow only one connection at a time, but stay alive. */ 379 for (;;) { 380 if (family != AF_UNIX) 381 s = local_listen(host, uport, hints); 382 if (s < 0) 383 err(1, "local_listen"); 384 /* 385 * For UDP and -k, don't connect the socket, let it 386 * receive datagrams from multiple socket pairs. 387 */ 388 if (uflag && kflag) 389 readwrite(s); 390 /* 391 * For UDP and not -k, we will use recvfrom() initially 392 * to wait for a caller, then use the regular functions 393 * to talk to the caller. 394 */ 395 else if (uflag && !kflag) { 396 int rv, plen; 397 char buf[16384]; 398 struct sockaddr_storage z; 399 400 len = sizeof(z); 401 plen = 2048; 402 rv = recvfrom(s, buf, plen, MSG_PEEK, 403 (struct sockaddr *)&z, &len); 404 if (rv < 0) 405 err(1, "recvfrom"); 406 407 rv = connect(s, (struct sockaddr *)&z, len); 408 if (rv < 0) 409 err(1, "connect"); 410 411 if (vflag) 412 report_connect((struct sockaddr *)&z, len); 413 414 readwrite(s); 415 } else { 416 len = sizeof(cliaddr); 417 connfd = accept(s, (struct sockaddr *)&cliaddr, 418 &len); 419 if (connfd == -1) { 420 /* For now, all errnos are fatal */ 421 err(1, "accept"); 422 } 423 if (vflag) 424 report_connect((struct sockaddr *)&cliaddr, len); 425 426 readwrite(connfd); 427 close(connfd); 428 } 429 430 if (family != AF_UNIX) 431 close(s); 432 else if (uflag) { 433 if (connect(s, NULL, 0) < 0) 434 err(1, "connect"); 435 } 436 437 if (!kflag) 438 break; 439 } 440 } else if (family == AF_UNIX) { 441 ret = 0; 442 443 if ((s = unix_connect(host)) > 0 && !zflag) { 444 readwrite(s); 445 close(s); 446 } else 447 ret = 1; 448 449 if (uflag) 450 unlink(unix_dg_tmp_socket); 451 exit(ret); 452 453 } else { 454 int i = 0; 455 456 /* Construct the portlist[] array. */ 457 build_ports(uport); 458 459 /* Cycle through portlist, connecting to each port. */ 460 for (i = 0; portlist[i] != NULL; i++) { 461 if (s) 462 close(s); 463 464 if (xflag) 465 s = socks_connect(host, portlist[i], hints, 466 proxyhost, proxyport, proxyhints, socksv, 467 Pflag); 468 else 469 s = remote_connect(host, portlist[i], hints); 470 471 if (s < 0) 472 continue; 473 474 ret = 0; 475 if (vflag || zflag) { 476 /* For UDP, make sure we are connected. */ 477 if (uflag) { 478 if (udptest(s) == -1) { 479 ret = 1; 480 continue; 481 } 482 } 483 484 /* Don't look up port if -n. */ 485 if (nflag) 486 sv = NULL; 487 else { 488 sv = getservbyport( 489 ntohs(atoi(portlist[i])), 490 uflag ? "udp" : "tcp"); 491 } 492 493 fprintf(stderr, 494 "Connection to %s %s port [%s/%s] " 495 "succeeded!\n", host, portlist[i], 496 uflag ? "udp" : "tcp", 497 sv ? sv->s_name : "*"); 498 } 499 if (Fflag) 500 fdpass(s); 501 else if (!zflag) 502 readwrite(s); 503 } 504 } 505 506 if (s) 507 close(s); 508 509 exit(ret); 510 } 511 512 /* 513 * unix_bind() 514 * Returns a unix socket bound to the given path 515 */ 516 int 517 unix_bind(char *path) 518 { 519 struct sockaddr_un sun_sa; 520 int s; 521 522 /* Create unix domain socket. */ 523 if ((s = socket(AF_UNIX, uflag ? SOCK_DGRAM : SOCK_STREAM, 524 0)) < 0) 525 return (-1); 526 527 memset(&sun_sa, 0, sizeof(struct sockaddr_un)); 528 sun_sa.sun_family = AF_UNIX; 529 530 if (strlcpy(sun_sa.sun_path, path, sizeof(sun_sa.sun_path)) >= 531 sizeof(sun_sa.sun_path)) { 532 close(s); 533 errno = ENAMETOOLONG; 534 return (-1); 535 } 536 537 if (bind(s, (struct sockaddr *)&sun_sa, SUN_LEN(&sun_sa)) < 0) { 538 close(s); 539 return (-1); 540 } 541 return (s); 542 } 543 544 /* 545 * unix_connect() 546 * Returns a socket connected to a local unix socket. Returns -1 on failure. 547 */ 548 int 549 unix_connect(char *path) 550 { 551 struct sockaddr_un sun_sa; 552 int s; 553 554 if (uflag) { 555 if ((s = unix_bind(unix_dg_tmp_socket)) < 0) 556 return (-1); 557 } else { 558 if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) 559 return (-1); 560 } 561 (void)fcntl(s, F_SETFD, FD_CLOEXEC); 562 563 memset(&sun_sa, 0, sizeof(struct sockaddr_un)); 564 sun_sa.sun_family = AF_UNIX; 565 566 if (strlcpy(sun_sa.sun_path, path, sizeof(sun_sa.sun_path)) >= 567 sizeof(sun_sa.sun_path)) { 568 close(s); 569 errno = ENAMETOOLONG; 570 return (-1); 571 } 572 if (connect(s, (struct sockaddr *)&sun_sa, SUN_LEN(&sun_sa)) < 0) { 573 close(s); 574 return (-1); 575 } 576 return (s); 577 578 } 579 580 /* 581 * unix_listen() 582 * Create a unix domain socket, and listen on it. 583 */ 584 int 585 unix_listen(char *path) 586 { 587 int s; 588 if ((s = unix_bind(path)) < 0) 589 return (-1); 590 591 if (listen(s, 5) < 0) { 592 close(s); 593 return (-1); 594 } 595 return (s); 596 } 597 598 /* 599 * remote_connect() 600 * Returns a socket connected to a remote host. Properly binds to a local 601 * port or source address if needed. Returns -1 on failure. 602 */ 603 int 604 remote_connect(const char *host, const char *port, struct addrinfo hints) 605 { 606 struct addrinfo *res, *res0; 607 int s, error; 608 #if defined(SO_RTABLE) || defined(SO_BINDANY) 609 int on = 1; 610 #endif 611 612 if ((error = getaddrinfo(host, port, &hints, &res))) 613 errx(1, "getaddrinfo: %s", gai_strerror(error)); 614 615 res0 = res; 616 do { 617 if ((s = socket(res0->ai_family, res0->ai_socktype, 618 res0->ai_protocol)) < 0) 619 continue; 620 621 #ifdef SO_RTABLE 622 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_RTABLE, 623 &rtableid, sizeof(rtableid)) == -1)) 624 err(1, "setsockopt SO_RTABLE"); 625 #endif 626 /* Bind to a local port or source address if specified. */ 627 if (sflag || pflag) { 628 struct addrinfo ahints, *ares; 629 630 #ifdef SO_BINDANY 631 /* try SO_BINDANY, but don't insist */ 632 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 633 #endif 634 memset(&ahints, 0, sizeof(struct addrinfo)); 635 ahints.ai_family = res0->ai_family; 636 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 637 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 638 ahints.ai_flags = AI_PASSIVE; 639 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 640 errx(1, "getaddrinfo: %s", gai_strerror(error)); 641 642 if (bind(s, (struct sockaddr *)ares->ai_addr, 643 ares->ai_addrlen) < 0) 644 err(1, "bind failed"); 645 freeaddrinfo(ares); 646 } 647 648 set_common_sockopts(s); 649 650 if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0) 651 break; 652 else if (vflag) 653 warn("connect to %s port %s (%s) failed", host, port, 654 uflag ? "udp" : "tcp"); 655 656 close(s); 657 s = -1; 658 } while ((res0 = res0->ai_next) != NULL); 659 660 freeaddrinfo(res); 661 662 return (s); 663 } 664 665 int 666 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 667 { 668 struct pollfd pfd; 669 socklen_t optlen; 670 int flags = 0, optval; 671 int ret; 672 673 if (timeout != -1) { 674 flags = fcntl(s, F_GETFL, 0); 675 if (fcntl(s, F_SETFL, flags | O_NONBLOCK) == -1) 676 err(1, "set non-blocking mode"); 677 } 678 679 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 680 pfd.fd = s; 681 pfd.events = POLLOUT; 682 if ((ret = poll(&pfd, 1, timeout)) == 1) { 683 optlen = sizeof(optval); 684 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 685 &optval, &optlen)) == 0) { 686 errno = optval; 687 ret = optval == 0 ? 0 : -1; 688 } 689 } else if (ret == 0) { 690 errno = ETIMEDOUT; 691 ret = -1; 692 } else 693 err(1, "poll failed"); 694 } 695 696 if (timeout != -1 && fcntl(s, F_SETFL, flags) == -1) 697 err(1, "restoring flags"); 698 699 return (ret); 700 } 701 702 /* 703 * local_listen() 704 * Returns a socket listening on a local port, binds to specified source 705 * address. Returns -1 on failure. 706 */ 707 int 708 local_listen(char *host, char *port, struct addrinfo hints) 709 { 710 struct addrinfo *res, *res0; 711 int s, ret, x = 1; 712 int error; 713 714 /* Allow nodename to be null. */ 715 hints.ai_flags |= AI_PASSIVE; 716 717 /* 718 * In the case of binding to a wildcard address 719 * default to binding to an ipv4 address. 720 */ 721 if (host == NULL && hints.ai_family == AF_UNSPEC) 722 hints.ai_family = AF_INET; 723 724 if ((error = getaddrinfo(host, port, &hints, &res))) 725 errx(1, "getaddrinfo: %s", gai_strerror(error)); 726 727 res0 = res; 728 do { 729 if ((s = socket(res0->ai_family, res0->ai_socktype, 730 res0->ai_protocol)) < 0) 731 continue; 732 733 #ifdef SO_RTABLE 734 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_RTABLE, 735 &rtableid, sizeof(rtableid)) == -1)) 736 err(1, "setsockopt SO_RTABLE"); 737 #endif 738 #ifdef SO_REUSEPORT 739 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 740 if (ret == -1) 741 err(1, "setsockopt"); 742 #endif 743 set_common_sockopts(s); 744 745 if (bind(s, (struct sockaddr *)res0->ai_addr, 746 res0->ai_addrlen) == 0) 747 break; 748 749 close(s); 750 s = -1; 751 } while ((res0 = res0->ai_next) != NULL); 752 753 if (!uflag && s != -1) { 754 if (listen(s, 1) < 0) 755 err(1, "listen"); 756 } 757 758 freeaddrinfo(res); 759 760 return (s); 761 } 762 763 /* 764 * readwrite() 765 * Loop that polls on the network file descriptor and stdin. 766 */ 767 void 768 readwrite(int net_fd) 769 { 770 struct pollfd pfd[4]; 771 int stdin_fd = STDIN_FILENO; 772 int stdout_fd = STDOUT_FILENO; 773 unsigned char netinbuf[BUFSIZE]; 774 size_t netinbufpos = 0; 775 unsigned char stdinbuf[BUFSIZE]; 776 size_t stdinbufpos = 0; 777 int n, num_fds; 778 ssize_t ret; 779 780 /* don't read from stdin if requested */ 781 if (dflag) 782 stdin_fd = -1; 783 784 /* stdin */ 785 pfd[POLL_STDIN].fd = stdin_fd; 786 pfd[POLL_STDIN].events = POLLIN; 787 788 /* network out */ 789 pfd[POLL_NETOUT].fd = net_fd; 790 pfd[POLL_NETOUT].events = 0; 791 792 /* network in */ 793 pfd[POLL_NETIN].fd = net_fd; 794 pfd[POLL_NETIN].events = POLLIN; 795 796 /* stdout */ 797 pfd[POLL_STDOUT].fd = stdout_fd; 798 pfd[POLL_STDOUT].events = 0; 799 800 while (1) { 801 /* both inputs are gone, buffers are empty, we are done */ 802 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 803 && stdinbufpos == 0 && netinbufpos == 0) { 804 close(net_fd); 805 return; 806 } 807 /* both outputs are gone, we can't continue */ 808 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 809 close(net_fd); 810 return; 811 } 812 /* listen and net in gone, queues empty, done */ 813 if (lflag && pfd[POLL_NETIN].fd == -1 814 && stdinbufpos == 0 && netinbufpos == 0) { 815 close(net_fd); 816 return; 817 } 818 819 /* help says -i is for "wait between lines sent". We read and 820 * write arbitrary amounts of data, and we don't want to start 821 * scanning for newlines, so this is as good as it gets */ 822 if (iflag) 823 sleep(iflag); 824 825 /* poll */ 826 num_fds = poll(pfd, 4, timeout); 827 828 /* treat poll errors */ 829 if (num_fds == -1) { 830 close(net_fd); 831 err(1, "polling error"); 832 } 833 834 /* timeout happened */ 835 if (num_fds == 0) 836 return; 837 838 /* treat socket error conditions */ 839 for (n = 0; n < 4; n++) { 840 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 841 pfd[n].fd = -1; 842 } 843 } 844 /* reading is possible after HUP */ 845 if (pfd[POLL_STDIN].events & POLLIN && 846 pfd[POLL_STDIN].revents & POLLHUP && 847 ! (pfd[POLL_STDIN].revents & POLLIN)) 848 pfd[POLL_STDIN].fd = -1; 849 850 if (pfd[POLL_NETIN].events & POLLIN && 851 pfd[POLL_NETIN].revents & POLLHUP && 852 ! (pfd[POLL_NETIN].revents & POLLIN)) 853 pfd[POLL_NETIN].fd = -1; 854 855 if (pfd[POLL_NETOUT].revents & POLLHUP) { 856 if (Nflag) 857 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 858 pfd[POLL_NETOUT].fd = -1; 859 } 860 /* if HUP, stop watching stdout */ 861 if (pfd[POLL_STDOUT].revents & POLLHUP) 862 pfd[POLL_STDOUT].fd = -1; 863 /* if no net out, stop watching stdin */ 864 if (pfd[POLL_NETOUT].fd == -1) 865 pfd[POLL_STDIN].fd = -1; 866 /* if no stdout, stop watching net in */ 867 if (pfd[POLL_STDOUT].fd == -1) { 868 if (pfd[POLL_NETIN].fd != -1) 869 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 870 pfd[POLL_NETIN].fd = -1; 871 } 872 873 /* try to read from stdin */ 874 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 875 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 876 &stdinbufpos); 877 /* error or eof on stdin - remove from pfd */ 878 if (ret == 0 || ret == -1) 879 pfd[POLL_STDIN].fd = -1; 880 /* read something - poll net out */ 881 if (stdinbufpos > 0) 882 pfd[POLL_NETOUT].events = POLLOUT; 883 /* filled buffer - remove self from polling */ 884 if (stdinbufpos == BUFSIZE) 885 pfd[POLL_STDIN].events = 0; 886 } 887 /* try to write to network */ 888 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 889 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 890 &stdinbufpos); 891 if (ret == -1) 892 pfd[POLL_NETOUT].fd = -1; 893 /* buffer empty - remove self from polling */ 894 if (stdinbufpos == 0) 895 pfd[POLL_NETOUT].events = 0; 896 /* buffer no longer full - poll stdin again */ 897 if (stdinbufpos < BUFSIZE) 898 pfd[POLL_STDIN].events = POLLIN; 899 } 900 /* try to read from network */ 901 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 902 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 903 &netinbufpos); 904 if (ret == -1) 905 pfd[POLL_NETIN].fd = -1; 906 /* eof on net in - remove from pfd */ 907 if (ret == 0) { 908 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 909 pfd[POLL_NETIN].fd = -1; 910 } 911 /* read something - poll stdout */ 912 if (netinbufpos > 0) 913 pfd[POLL_STDOUT].events = POLLOUT; 914 /* filled buffer - remove self from polling */ 915 if (netinbufpos == BUFSIZE) 916 pfd[POLL_NETIN].events = 0; 917 /* handle telnet */ 918 if (tflag) 919 atelnet(pfd[POLL_NETIN].fd, netinbuf, 920 netinbufpos); 921 } 922 /* try to write to stdout */ 923 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 924 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 925 &netinbufpos); 926 if (ret == -1) 927 pfd[POLL_STDOUT].fd = -1; 928 /* buffer empty - remove self from polling */ 929 if (netinbufpos == 0) 930 pfd[POLL_STDOUT].events = 0; 931 /* buffer no longer full - poll net in again */ 932 if (netinbufpos < BUFSIZE) 933 pfd[POLL_NETIN].events = POLLIN; 934 } 935 936 /* stdin gone and queue empty? */ 937 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 938 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 939 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 940 pfd[POLL_NETOUT].fd = -1; 941 } 942 /* net in gone and queue empty? */ 943 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 944 pfd[POLL_STDOUT].fd = -1; 945 } 946 } 947 } 948 949 ssize_t 950 drainbuf(int fd, unsigned char *buf, size_t *bufpos) 951 { 952 ssize_t n; 953 ssize_t adjust; 954 955 n = write(fd, buf, *bufpos); 956 /* don't treat EAGAIN, EINTR as error */ 957 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 958 n = -2; 959 if (n <= 0) 960 return n; 961 /* adjust buffer */ 962 adjust = *bufpos - n; 963 if (adjust > 0) 964 memmove(buf, buf + n, adjust); 965 *bufpos -= n; 966 return n; 967 } 968 969 970 ssize_t 971 fillbuf(int fd, unsigned char *buf, size_t *bufpos) 972 { 973 size_t num = BUFSIZE - *bufpos; 974 ssize_t n; 975 976 n = read(fd, buf + *bufpos, num); 977 /* don't treat EAGAIN, EINTR as error */ 978 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 979 n = -2; 980 if (n <= 0) 981 return n; 982 *bufpos += n; 983 return n; 984 } 985 986 /* 987 * fdpass() 988 * Pass the connected file descriptor to stdout and exit. 989 */ 990 void 991 fdpass(int nfd) 992 { 993 #if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) 994 struct msghdr msg; 995 #ifndef HAVE_ACCRIGHTS_IN_MSGHDR 996 union { 997 struct cmsghdr hdr; 998 char buf[CMSG_SPACE(sizeof(int))]; 999 } cmsgbuf; 1000 struct cmsghdr *cmsg; 1001 #endif 1002 struct iovec vec; 1003 char ch = '\0'; 1004 struct pollfd pfd; 1005 ssize_t r; 1006 1007 memset(&msg, 0, sizeof(msg)); 1008 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR 1009 msg.msg_accrights = (caddr_t)&nfd; 1010 msg.msg_accrightslen = sizeof(nfd); 1011 #else 1012 memset(&cmsgbuf, 0, sizeof(cmsgbuf)); 1013 msg.msg_control = (caddr_t)&cmsgbuf.buf; 1014 msg.msg_controllen = sizeof(cmsgbuf.buf); 1015 cmsg = CMSG_FIRSTHDR(&msg); 1016 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1017 cmsg->cmsg_level = SOL_SOCKET; 1018 cmsg->cmsg_type = SCM_RIGHTS; 1019 *(int *)CMSG_DATA(cmsg) = nfd; 1020 #endif 1021 1022 vec.iov_base = &ch; 1023 vec.iov_len = 1; 1024 msg.msg_iov = &vec; 1025 msg.msg_iovlen = 1; 1026 1027 bzero(&pfd, sizeof(pfd)); 1028 pfd.fd = STDOUT_FILENO; 1029 for (;;) { 1030 r = sendmsg(STDOUT_FILENO, &msg, 0); 1031 if (r == -1) { 1032 if (errno == EAGAIN || errno == EINTR) { 1033 pfd.events = POLLOUT; 1034 if (poll(&pfd, 1, -1) == -1) 1035 err(1, "poll"); 1036 continue; 1037 } 1038 err(1, "sendmsg"); 1039 } else if (r == -1) 1040 errx(1, "sendmsg: unexpected return value %zd", r); 1041 else 1042 break; 1043 } 1044 exit(0); 1045 #else 1046 errx(1, "%s: file descriptor passing not supported", __func__); 1047 #endif 1048 } 1049 1050 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1051 void 1052 atelnet(int nfd, unsigned char *buf, unsigned int size) 1053 { 1054 unsigned char *p, *end; 1055 unsigned char obuf[4]; 1056 1057 if (size < 3) 1058 return; 1059 end = buf + size - 2; 1060 1061 for (p = buf; p < end; p++) { 1062 if (*p != IAC) 1063 continue; 1064 1065 obuf[0] = IAC; 1066 p++; 1067 if ((*p == WILL) || (*p == WONT)) 1068 obuf[1] = DONT; 1069 else if ((*p == DO) || (*p == DONT)) 1070 obuf[1] = WONT; 1071 else 1072 continue; 1073 1074 p++; 1075 obuf[2] = *p; 1076 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1077 warn("Write Error!"); 1078 } 1079 } 1080 1081 /* 1082 * build_ports() 1083 * Build an array of ports in portlist[], listing each port 1084 * that we should try to connect to. 1085 */ 1086 void 1087 build_ports(char *p) 1088 { 1089 const char *errstr; 1090 char *n; 1091 int hi, lo, cp; 1092 int x = 0; 1093 1094 if ((n = strchr(p, '-')) != NULL) { 1095 *n = '\0'; 1096 n++; 1097 1098 /* Make sure the ports are in order: lowest->highest. */ 1099 hi = strtonum(n, 1, PORT_MAX, &errstr); 1100 if (errstr) 1101 errx(1, "port number %s: %s", errstr, n); 1102 lo = strtonum(p, 1, PORT_MAX, &errstr); 1103 if (errstr) 1104 errx(1, "port number %s: %s", errstr, p); 1105 1106 if (lo > hi) { 1107 cp = hi; 1108 hi = lo; 1109 lo = cp; 1110 } 1111 1112 /* Load ports sequentially. */ 1113 for (cp = lo; cp <= hi; cp++) { 1114 portlist[x] = calloc(1, PORT_MAX_LEN); 1115 if (portlist[x] == NULL) 1116 errx(1, "calloc"); 1117 snprintf(portlist[x], PORT_MAX_LEN, "%d", cp); 1118 x++; 1119 } 1120 1121 /* Randomly swap ports. */ 1122 if (rflag) { 1123 int y; 1124 char *c; 1125 1126 for (x = 0; x <= (hi - lo); x++) { 1127 y = (arc4random() & 0xFFFF) % (hi - lo); 1128 c = portlist[x]; 1129 portlist[x] = portlist[y]; 1130 portlist[y] = c; 1131 } 1132 } 1133 } else { 1134 hi = strtonum(p, 1, PORT_MAX, &errstr); 1135 if (errstr) 1136 errx(1, "port number %s: %s", errstr, p); 1137 portlist[0] = strdup(p); 1138 if (portlist[0] == NULL) 1139 errx(1, "strdup"); 1140 } 1141 } 1142 1143 /* 1144 * udptest() 1145 * Do a few writes to see if the UDP port is there. 1146 * Fails once PF state table is full. 1147 */ 1148 int 1149 udptest(int s) 1150 { 1151 int i, ret; 1152 1153 for (i = 0; i <= 3; i++) { 1154 if (write(s, "X", 1) == 1) 1155 ret = 1; 1156 else 1157 ret = -1; 1158 } 1159 return (ret); 1160 } 1161 1162 void 1163 set_common_sockopts(int s) 1164 { 1165 int x = 1; 1166 1167 #ifdef TCP_MD5SIG 1168 if (Sflag) { 1169 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1170 &x, sizeof(x)) == -1) 1171 err(1, "setsockopt"); 1172 } 1173 #endif 1174 if (Dflag) { 1175 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1176 &x, sizeof(x)) == -1) 1177 err(1, "setsockopt"); 1178 } 1179 if (Tflag != -1) { 1180 if (setsockopt(s, IPPROTO_IP, IP_TOS, 1181 &Tflag, sizeof(Tflag)) == -1) 1182 err(1, "set IP ToS"); 1183 } 1184 if (Iflag) { 1185 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1186 &Iflag, sizeof(Iflag)) == -1) 1187 err(1, "set TCP receive buffer size"); 1188 } 1189 if (Oflag) { 1190 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1191 &Oflag, sizeof(Oflag)) == -1) 1192 err(1, "set TCP send buffer size"); 1193 } 1194 } 1195 1196 int 1197 map_tos(char *s, int *val) 1198 { 1199 /* DiffServ Codepoints and other TOS mappings */ 1200 const struct toskeywords { 1201 const char *keyword; 1202 int val; 1203 } *t, toskeywords[] = { 1204 { "af11", IPTOS_DSCP_AF11 }, 1205 { "af12", IPTOS_DSCP_AF12 }, 1206 { "af13", IPTOS_DSCP_AF13 }, 1207 { "af21", IPTOS_DSCP_AF21 }, 1208 { "af22", IPTOS_DSCP_AF22 }, 1209 { "af23", IPTOS_DSCP_AF23 }, 1210 { "af31", IPTOS_DSCP_AF31 }, 1211 { "af32", IPTOS_DSCP_AF32 }, 1212 { "af33", IPTOS_DSCP_AF33 }, 1213 { "af41", IPTOS_DSCP_AF41 }, 1214 { "af42", IPTOS_DSCP_AF42 }, 1215 { "af43", IPTOS_DSCP_AF43 }, 1216 { "critical", IPTOS_PREC_CRITIC_ECP }, 1217 { "cs0", IPTOS_DSCP_CS0 }, 1218 { "cs1", IPTOS_DSCP_CS1 }, 1219 { "cs2", IPTOS_DSCP_CS2 }, 1220 { "cs3", IPTOS_DSCP_CS3 }, 1221 { "cs4", IPTOS_DSCP_CS4 }, 1222 { "cs5", IPTOS_DSCP_CS5 }, 1223 { "cs6", IPTOS_DSCP_CS6 }, 1224 { "cs7", IPTOS_DSCP_CS7 }, 1225 { "ef", IPTOS_DSCP_EF }, 1226 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1227 { "lowdelay", IPTOS_LOWDELAY }, 1228 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1229 { "reliability", IPTOS_RELIABILITY }, 1230 { "throughput", IPTOS_THROUGHPUT }, 1231 { NULL, -1 }, 1232 }; 1233 1234 for (t = toskeywords; t->keyword != NULL; t++) { 1235 if (strcmp(s, t->keyword) == 0) { 1236 *val = t->val; 1237 return (1); 1238 } 1239 } 1240 1241 return (0); 1242 } 1243 1244 void 1245 report_connect(const struct sockaddr *sa, socklen_t salen) 1246 { 1247 char remote_host[NI_MAXHOST]; 1248 char remote_port[NI_MAXSERV]; 1249 int herr; 1250 int flags = NI_NUMERICSERV; 1251 1252 if (nflag) 1253 flags |= NI_NUMERICHOST; 1254 1255 if ((herr = getnameinfo(sa, salen, 1256 remote_host, sizeof(remote_host), 1257 remote_port, sizeof(remote_port), 1258 flags)) != 0) { 1259 if (herr == EAI_SYSTEM) 1260 err(1, "getnameinfo"); 1261 else 1262 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1263 } 1264 1265 fprintf(stderr, 1266 "Connection from %s %s " 1267 "received!\n", remote_host, remote_port); 1268 } 1269 1270 void 1271 help(void) 1272 { 1273 usage(0); 1274 fprintf(stderr, "\tCommand Summary:\n\ 1275 \t-4 Use IPv4\n\ 1276 \t-6 Use IPv6\n\ 1277 \t-D Enable the debug socket option\n\ 1278 \t-d Detach from stdin\n\ 1279 \t-F Pass socket fd\n\ 1280 \t-h This help text\n\ 1281 \t-I length TCP receive buffer length\n\ 1282 \t-i secs\t Delay interval for lines sent, ports scanned\n\ 1283 \t-k Keep inbound sockets open for multiple connects\n\ 1284 \t-l Listen mode, for inbound connects\n\ 1285 \t-N Shutdown the network socket after EOF on stdin\n\ 1286 \t-n Suppress name/port resolutions\n\ 1287 \t-O length TCP send buffer length\n\ 1288 \t-P proxyuser\tUsername for proxy authentication\n\ 1289 \t-p port\t Specify local port for remote connects\n\ 1290 \t-r Randomize remote ports\n\ 1291 \t-S Enable the TCP MD5 signature option\n\ 1292 \t-s addr\t Local source address\n\ 1293 \t-T toskeyword\tSet IP Type of Service\n\ 1294 \t-t Answer TELNET negotiation\n\ 1295 \t-U Use UNIX domain socket\n\ 1296 \t-u UDP mode\n\ 1297 \t-V rtable Specify alternate routing table\n\ 1298 \t-v Verbose\n\ 1299 \t-w secs\t Timeout for connects and final net reads\n\ 1300 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1301 \t-x addr[:port]\tSpecify proxy address and port\n\ 1302 \t-z Zero-I/O mode [used for scanning]\n\ 1303 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1304 exit(1); 1305 } 1306 1307 void 1308 usage(int ret) 1309 { 1310 fprintf(stderr, 1311 "usage: nc [-46DdFhklNnrStUuvz] [-I length] [-i interval] [-O length]\n" 1312 "\t [-P proxy_username] [-p source_port] [-s source] [-T ToS]\n" 1313 "\t [-V rtable] [-w timeout] [-X proxy_protocol]\n" 1314 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1315 if (ret) 1316 exit(1); 1317 } 1318 1319 /* *** src/usr.bin/nc/socks.c *** */ 1320 1321 1322 /* $OpenBSD: socks.c,v 1.20 2012/03/08 09:56:28 espie Exp $ */ 1323 1324 /* 1325 * Copyright (c) 1999 Niklas Hallqvist. All rights reserved. 1326 * Copyright (c) 2004, 2005 Damien Miller. All rights reserved. 1327 * 1328 * Redistribution and use in source and binary forms, with or without 1329 * modification, are permitted provided that the following conditions 1330 * are met: 1331 * 1. Redistributions of source code must retain the above copyright 1332 * notice, this list of conditions and the following disclaimer. 1333 * 2. Redistributions in binary form must reproduce the above copyright 1334 * notice, this list of conditions and the following disclaimer in the 1335 * documentation and/or other materials provided with the distribution. 1336 * 1337 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1338 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1339 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1340 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1341 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 1342 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 1343 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 1344 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 1345 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 1346 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 1347 */ 1348 1349 #include <sys/types.h> 1350 #include <sys/socket.h> 1351 #include <netinet/in.h> 1352 #include <arpa/inet.h> 1353 1354 #include <errno.h> 1355 #include <netdb.h> 1356 #include <stdio.h> 1357 #include <stdlib.h> 1358 #include <string.h> 1359 #include <unistd.h> 1360 #include <resolv.h> 1361 1362 #define SOCKS_PORT "1080" 1363 #define HTTP_PROXY_PORT "3128" 1364 #define HTTP_MAXHDRS 64 1365 #define SOCKS_V5 5 1366 #define SOCKS_V4 4 1367 #define SOCKS_NOAUTH 0 1368 #define SOCKS_NOMETHOD 0xff 1369 #define SOCKS_CONNECT 1 1370 #define SOCKS_IPV4 1 1371 #define SOCKS_DOMAIN 3 1372 #define SOCKS_IPV6 4 1373 1374 int remote_connect(const char *, const char *, struct addrinfo); 1375 int socks_connect(const char *, const char *, struct addrinfo, 1376 const char *, const char *, struct addrinfo, int, 1377 const char *); 1378 1379 static int 1380 decode_addrport(const char *h, const char *p, struct sockaddr *addr, 1381 socklen_t addrlen, int v4only, int numeric) 1382 { 1383 int r; 1384 struct addrinfo hints, *res; 1385 1386 bzero(&hints, sizeof(hints)); 1387 hints.ai_family = v4only ? PF_INET : PF_UNSPEC; 1388 hints.ai_flags = numeric ? AI_NUMERICHOST : 0; 1389 hints.ai_socktype = SOCK_STREAM; 1390 r = getaddrinfo(h, p, &hints, &res); 1391 /* Don't fatal when attempting to convert a numeric address */ 1392 if (r != 0) { 1393 if (!numeric) { 1394 errx(1, "getaddrinfo(\"%.64s\", \"%.64s\"): %s", h, p, 1395 gai_strerror(r)); 1396 } 1397 return (-1); 1398 } 1399 if (addrlen < res->ai_addrlen) { 1400 freeaddrinfo(res); 1401 errx(1, "internal error: addrlen < res->ai_addrlen"); 1402 } 1403 memcpy(addr, res->ai_addr, res->ai_addrlen); 1404 freeaddrinfo(res); 1405 return (0); 1406 } 1407 1408 static int 1409 proxy_read_line(int fd, char *buf, size_t bufsz) 1410 { 1411 size_t off; 1412 1413 for(off = 0;;) { 1414 if (off >= bufsz) 1415 errx(1, "proxy read too long"); 1416 if (atomicio(read, fd, buf + off, 1) != 1) 1417 err(1, "proxy read"); 1418 /* Skip CR */ 1419 if (buf[off] == '\r') 1420 continue; 1421 if (buf[off] == '\n') { 1422 buf[off] = '\0'; 1423 break; 1424 } 1425 off++; 1426 } 1427 return (off); 1428 } 1429 1430 static const char * 1431 getproxypass(const char *proxyuser, const char *proxyhost) 1432 { 1433 char prompt[512]; 1434 static char pw[256]; 1435 1436 snprintf(prompt, sizeof(prompt), "Proxy password for %s@%s: ", 1437 proxyuser, proxyhost); 1438 if (readpassphrase(prompt, pw, sizeof(pw), RPP_REQUIRE_TTY) == NULL) 1439 errx(1, "Unable to read proxy passphrase"); 1440 return (pw); 1441 } 1442 1443 int 1444 socks_connect(const char *host, const char *port, 1445 struct addrinfo hints __attribute__ ((__unused__)), 1446 const char *proxyhost, const char *proxyport, struct addrinfo proxyhints, 1447 int socksv, const char *proxyuser) 1448 { 1449 int proxyfd, r, authretry = 0; 1450 size_t hlen, wlen = 0; 1451 unsigned char buf[1024]; 1452 size_t cnt; 1453 struct sockaddr_storage addr; 1454 struct sockaddr_in *in4 = (struct sockaddr_in *)&addr; 1455 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)&addr; 1456 in_port_t serverport; 1457 const char *proxypass = NULL; 1458 1459 if (proxyport == NULL) 1460 proxyport = (socksv == -1) ? HTTP_PROXY_PORT : SOCKS_PORT; 1461 1462 /* Abuse API to lookup port */ 1463 if (decode_addrport("0.0.0.0", port, (struct sockaddr *)&addr, 1464 sizeof(addr), 1, 1) == -1) 1465 errx(1, "unknown port \"%.64s\"", port); 1466 serverport = in4->sin_port; 1467 1468 again: 1469 if (authretry++ > 3) 1470 errx(1, "Too many authentication failures"); 1471 1472 proxyfd = remote_connect(proxyhost, proxyport, proxyhints); 1473 1474 if (proxyfd < 0) 1475 return (-1); 1476 1477 if (socksv == 5) { 1478 if (decode_addrport(host, port, (struct sockaddr *)&addr, 1479 sizeof(addr), 0, 1) == -1) 1480 addr.ss_family = 0; /* used in switch below */ 1481 1482 /* Version 5, one method: no authentication */ 1483 buf[0] = SOCKS_V5; 1484 buf[1] = 1; 1485 buf[2] = SOCKS_NOAUTH; 1486 cnt = atomicio(vwrite, proxyfd, buf, 3); 1487 if (cnt != 3) 1488 err(1, "write failed (%zu/3)", cnt); 1489 1490 cnt = atomicio(read, proxyfd, buf, 2); 1491 if (cnt != 2) 1492 err(1, "read failed (%zu/3)", cnt); 1493 1494 if (buf[1] == SOCKS_NOMETHOD) 1495 errx(1, "authentication method negotiation failed"); 1496 1497 switch (addr.ss_family) { 1498 case 0: 1499 /* Version 5, connect: domain name */ 1500 1501 /* Max domain name length is 255 bytes */ 1502 hlen = strlen(host); 1503 if (hlen > 255) 1504 errx(1, "host name too long for SOCKS5"); 1505 buf[0] = SOCKS_V5; 1506 buf[1] = SOCKS_CONNECT; 1507 buf[2] = 0; 1508 buf[3] = SOCKS_DOMAIN; 1509 buf[4] = hlen; 1510 memcpy(buf + 5, host, hlen); 1511 memcpy(buf + 5 + hlen, &serverport, sizeof serverport); 1512 wlen = 7 + hlen; 1513 break; 1514 case AF_INET: 1515 /* Version 5, connect: IPv4 address */ 1516 buf[0] = SOCKS_V5; 1517 buf[1] = SOCKS_CONNECT; 1518 buf[2] = 0; 1519 buf[3] = SOCKS_IPV4; 1520 memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr); 1521 memcpy(buf + 8, &in4->sin_port, sizeof in4->sin_port); 1522 wlen = 10; 1523 break; 1524 case AF_INET6: 1525 /* Version 5, connect: IPv6 address */ 1526 buf[0] = SOCKS_V5; 1527 buf[1] = SOCKS_CONNECT; 1528 buf[2] = 0; 1529 buf[3] = SOCKS_IPV6; 1530 memcpy(buf + 4, &in6->sin6_addr, sizeof in6->sin6_addr); 1531 memcpy(buf + 20, &in6->sin6_port, 1532 sizeof in6->sin6_port); 1533 wlen = 22; 1534 break; 1535 default: 1536 errx(1, "internal error: silly AF"); 1537 } 1538 1539 cnt = atomicio(vwrite, proxyfd, buf, wlen); 1540 if (cnt != wlen) 1541 err(1, "write failed (%zu/%zu)", cnt, wlen); 1542 1543 cnt = atomicio(read, proxyfd, buf, 4); 1544 if (cnt != 4) 1545 err(1, "read failed (%zu/4)", cnt); 1546 if (buf[1] != 0) 1547 errx(1, "connection failed, SOCKS error %d", buf[1]); 1548 switch (buf[3]) { 1549 case SOCKS_IPV4: 1550 cnt = atomicio(read, proxyfd, buf + 4, 6); 1551 if (cnt != 6) 1552 err(1, "read failed (%zu/6)", cnt); 1553 break; 1554 case SOCKS_IPV6: 1555 cnt = atomicio(read, proxyfd, buf + 4, 18); 1556 if (cnt != 18) 1557 err(1, "read failed (%zu/18)", cnt); 1558 break; 1559 default: 1560 errx(1, "connection failed, unsupported address type"); 1561 } 1562 } else if (socksv == 4) { 1563 /* This will exit on lookup failure */ 1564 decode_addrport(host, port, (struct sockaddr *)&addr, 1565 sizeof(addr), 1, 0); 1566 1567 /* Version 4 */ 1568 buf[0] = SOCKS_V4; 1569 buf[1] = SOCKS_CONNECT; /* connect */ 1570 memcpy(buf + 2, &in4->sin_port, sizeof in4->sin_port); 1571 memcpy(buf + 4, &in4->sin_addr, sizeof in4->sin_addr); 1572 buf[8] = 0; /* empty username */ 1573 wlen = 9; 1574 1575 cnt = atomicio(vwrite, proxyfd, buf, wlen); 1576 if (cnt != wlen) 1577 err(1, "write failed (%zu/%zu)", cnt, wlen); 1578 1579 cnt = atomicio(read, proxyfd, buf, 8); 1580 if (cnt != 8) 1581 err(1, "read failed (%zu/8)", cnt); 1582 if (buf[1] != 90) 1583 errx(1, "connection failed, SOCKS error %d", buf[1]); 1584 } else if (socksv == -1) { 1585 /* HTTP proxy CONNECT */ 1586 1587 /* Disallow bad chars in hostname */ 1588 if (strcspn(host, "\r\n\t []:") != strlen(host)) 1589 errx(1, "Invalid hostname"); 1590 1591 /* Try to be sane about numeric IPv6 addresses */ 1592 if (strchr(host, ':') != NULL) { 1593 r = snprintf(buf, sizeof(buf), 1594 "CONNECT [%s]:%d HTTP/1.0\r\n", 1595 host, ntohs(serverport)); 1596 } else { 1597 r = snprintf(buf, sizeof(buf), 1598 "CONNECT %s:%d HTTP/1.0\r\n", 1599 host, ntohs(serverport)); 1600 } 1601 if (r == -1 || (size_t)r >= sizeof(buf)) 1602 errx(1, "hostname too long"); 1603 r = strlen(buf); 1604 1605 cnt = atomicio(vwrite, proxyfd, buf, r); 1606 if (cnt != (size_t)r) 1607 err(1, "write failed (%zu/%d)", cnt, r); 1608 1609 if (authretry > 1) { 1610 char resp[1024]; 1611 1612 proxypass = getproxypass(proxyuser, proxyhost); 1613 r = snprintf(buf, sizeof(buf), "%s:%s", 1614 proxyuser, proxypass); 1615 if (r == -1 || (size_t)r >= sizeof(buf) || 1616 b64_ntop(buf, strlen(buf), resp, 1617 sizeof(resp)) == -1) 1618 errx(1, "Proxy username/password too long"); 1619 r = snprintf(buf, sizeof(buf), "Proxy-Authorization: " 1620 "Basic %s\r\n", resp); 1621 if (r == -1 || (size_t)r >= sizeof(buf)) 1622 errx(1, "Proxy auth response too long"); 1623 r = strlen(buf); 1624 if ((cnt = atomicio(vwrite, proxyfd, buf, r)) != (size_t)r) 1625 err(1, "write failed (%zu/%d)", cnt, r); 1626 } 1627 1628 /* Terminate headers */ 1629 if ((r = atomicio(vwrite, proxyfd, "\r\n", 2)) != 2) 1630 err(1, "write failed (2/%d)", r); 1631 1632 /* Read status reply */ 1633 proxy_read_line(proxyfd, buf, sizeof(buf)); 1634 if (proxyuser != NULL && 1635 strncmp(buf, "HTTP/1.0 407 ", 12) == 0) { 1636 if (authretry > 1) { 1637 fprintf(stderr, "Proxy authentication " 1638 "failed\n"); 1639 } 1640 close(proxyfd); 1641 goto again; 1642 } else if (strncmp(buf, "HTTP/1.0 200 ", 12) != 0 && 1643 strncmp(buf, "HTTP/1.1 200 ", 12) != 0) 1644 errx(1, "Proxy error: \"%s\"", buf); 1645 1646 /* Headers continue until we hit an empty line */ 1647 for (r = 0; r < HTTP_MAXHDRS; r++) { 1648 proxy_read_line(proxyfd, buf, sizeof(buf)); 1649 if (*buf == '\0') 1650 break; 1651 } 1652 if (*buf != '\0') 1653 errx(1, "Too many proxy headers received"); 1654 } else 1655 errx(1, "Unknown proxy protocol %d", socksv); 1656 1657 return (proxyfd); 1658 } 1659 1660
