1 /* $OpenBSD: netcat.c,v 1.130 2015/07/26 19:12:28 chl Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj@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 * $FreeBSD$ 29 */ 30 31 /* 32 * Re-written nc(1) for OpenBSD. Original implementation by 33 * *Hobbit* <hobbit@avian.org>. 34 */ 35 36 #include <errno.h> 37 #include <stdio.h> 38 #include <sys/arb.h> 39 #include <sys/limits.h> 40 #include <sys/types.h> 41 #include <sys/sbuf.h> 42 #include <sys/socket.h> 43 #include <sys/sysctl.h> 44 #include <sys/qmath.h> 45 #include <sys/stats.h> 46 #include <sys/time.h> 47 #include <sys/uio.h> 48 #include <sys/un.h> 49 50 #include <netinet/in.h> 51 #ifdef IPSEC 52 #include <netipsec/ipsec.h> 53 #endif 54 #include <netinet/tcp.h> 55 #include <netinet/ip.h> 56 #include <arpa/telnet.h> 57 58 #include <err.h> 59 #include <getopt.h> 60 #include <fcntl.h> 61 #include <limits.h> 62 #include <netdb.h> 63 #include <poll.h> 64 #include <signal.h> 65 #include <stdarg.h> 66 #include <stdlib.h> 67 #include <string.h> 68 #include <unistd.h> 69 #include "atomicio.h" 70 71 #ifndef SUN_LEN 72 #define SUN_LEN(su) \ 73 (sizeof(*(su)) - sizeof((su)->sun_path) + strlen((su)->sun_path)) 74 #endif 75 76 #define PORT_MAX 65535 77 #define PORT_MAX_LEN 6 78 #define UNIX_DG_TMP_SOCKET_SIZE 19 79 80 #define POLL_STDIN 0 81 #define POLL_NETOUT 1 82 #define POLL_NETIN 2 83 #define POLL_STDOUT 3 84 #define BUFSIZE 16384 85 86 /* Command Line Options */ 87 int dflag; /* detached, no stdin */ 88 int Fflag; /* fdpass sock to stdout */ 89 unsigned int iflag; /* Interval Flag */ 90 int kflag; /* More than one connect */ 91 int lflag; /* Bind to local port */ 92 int FreeBSD_Mflag; /* Measure using stats(3) */ 93 int Nflag; /* shutdown() network socket */ 94 int nflag; /* Don't do name look up */ 95 int FreeBSD_Oflag; /* Do not use TCP options */ 96 int FreeBSD_sctp; /* Use SCTP */ 97 int FreeBSD_crlf; /* Convert LF to CRLF */ 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 int tun_fd = -1; 117 char *portlist[PORT_MAX+1]; 118 char *unix_dg_tmp_socket; 119 120 void atelnet(int, unsigned char *, unsigned int); 121 void build_ports(char *); 122 void help(void); 123 int local_listen(char *, char *, struct addrinfo); 124 void readwrite(int); 125 void fdpass(int nfd) __attribute__((noreturn)); 126 int remote_connect(const char *, const char *, struct addrinfo); 127 int timeout_connect(int, const struct sockaddr *, socklen_t); 128 int socks_connect(const char *, const char *, struct addrinfo, 129 const char *, const char *, struct addrinfo, int, const char *); 130 int udptest(int); 131 int unix_bind(char *); 132 int unix_connect(char *); 133 int unix_listen(char *); 134 void FreeBSD_stats_setup(int); 135 void FreeBSD_stats_print(int); 136 void set_common_sockopts(int, int); 137 int map_tos(char *, int *); 138 void report_connect(const struct sockaddr *, socklen_t); 139 void usage(int); 140 ssize_t write_wrapper(int, const void *, size_t); 141 ssize_t drainbuf(int, unsigned char *, size_t *, int); 142 ssize_t fillbuf(int, unsigned char *, size_t *); 143 144 #ifdef IPSEC 145 void add_ipsec_policy(int, int, char *); 146 147 char *ipsec_policy[2]; 148 #endif 149 150 enum { 151 FREEBSD_TUN = CHAR_MAX, /* avoid collision with return values from getopt */ 152 }; 153 154 int 155 main(int argc, char *argv[]) 156 { 157 int ch, s, ret, socksv, ipsec_count; 158 int numfibs; 159 size_t intsize = sizeof(int); 160 char *host, *uport; 161 struct addrinfo hints; 162 struct servent *sv; 163 socklen_t len; 164 struct sockaddr_storage cliaddr; 165 char *proxy; 166 const char *errstr, *proxyhost = "", *proxyport = NULL, *tundev = NULL; 167 struct addrinfo proxyhints; 168 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 169 struct option longopts[] = { 170 { "crlf", no_argument, &FreeBSD_crlf, 1 }, 171 { "no-tcpopt", no_argument, &FreeBSD_Oflag, 1 }, 172 { "sctp", no_argument, &FreeBSD_sctp, 1 }, 173 { "tun", required_argument, NULL, FREEBSD_TUN }, 174 { NULL, 0, NULL, 0 } 175 }; 176 177 ret = 1; 178 ipsec_count = 0; 179 s = 0; 180 socksv = 5; 181 host = NULL; 182 uport = NULL; 183 sv = NULL; 184 185 signal(SIGPIPE, SIG_IGN); 186 187 while ((ch = getopt_long(argc, argv, 188 "46DdEe:FhI:i:klMNnoO:P:p:rSs:tT:UuV:vw:X:x:z", 189 longopts, NULL)) != -1) { 190 switch (ch) { 191 case '4': 192 family = AF_INET; 193 break; 194 case '6': 195 family = AF_INET6; 196 break; 197 case 'U': 198 family = AF_UNIX; 199 break; 200 case 'X': 201 if (strcasecmp(optarg, "connect") == 0) 202 socksv = -1; /* HTTP proxy CONNECT */ 203 else if (strcmp(optarg, "4") == 0) 204 socksv = 4; /* SOCKS v.4 */ 205 else if (strcmp(optarg, "5") == 0) 206 socksv = 5; /* SOCKS v.5 */ 207 else 208 errx(1, "unsupported proxy protocol"); 209 break; 210 case 'd': 211 dflag = 1; 212 break; 213 case 'e': 214 #ifdef IPSEC 215 ipsec_policy[ipsec_count++ % 2] = optarg; 216 #else 217 errx(1, "IPsec support unavailable."); 218 #endif 219 break; 220 case 'E': 221 #ifdef IPSEC 222 ipsec_policy[0] = "in ipsec esp/transport//require"; 223 ipsec_policy[1] = "out ipsec esp/transport//require"; 224 #else 225 errx(1, "IPsec support unavailable."); 226 #endif 227 break; 228 case 'F': 229 Fflag = 1; 230 break; 231 case 'h': 232 help(); 233 break; 234 case 'i': 235 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 236 if (errstr) 237 errx(1, "interval %s: %s", errstr, optarg); 238 break; 239 case 'k': 240 kflag = 1; 241 break; 242 case 'l': 243 lflag = 1; 244 break; 245 case 'M': 246 #ifndef WITH_STATS 247 errx(1, "-M requires stats(3) support"); 248 #else 249 FreeBSD_Mflag = 1; 250 #endif 251 break; 252 case 'N': 253 Nflag = 1; 254 break; 255 case 'n': 256 nflag = 1; 257 break; 258 case 'o': 259 fprintf(stderr, "option -o is deprecated.\n"); 260 break; 261 case 'P': 262 Pflag = optarg; 263 break; 264 case 'p': 265 pflag = optarg; 266 break; 267 case 'r': 268 rflag = 1; 269 break; 270 case 's': 271 sflag = optarg; 272 break; 273 case 't': 274 tflag = 1; 275 break; 276 case 'u': 277 uflag = 1; 278 break; 279 case 'V': 280 if (sysctlbyname("net.fibs", &numfibs, &intsize, NULL, 0) == -1) 281 errx(1, "Multiple FIBS not supported"); 282 rtableid = (int)strtonum(optarg, 0, 283 numfibs - 1, &errstr); 284 if (errstr) 285 errx(1, "rtable %s: %s", errstr, optarg); 286 break; 287 case 'v': 288 vflag = 1; 289 break; 290 case 'w': 291 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 292 if (errstr) 293 errx(1, "timeout %s: %s", errstr, optarg); 294 timeout *= 1000; 295 break; 296 case 'x': 297 xflag = 1; 298 if ((proxy = strdup(optarg)) == NULL) 299 err(1, NULL); 300 break; 301 case 'z': 302 zflag = 1; 303 break; 304 case 'D': 305 Dflag = 1; 306 break; 307 case 'I': 308 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 309 if (errstr != NULL) 310 errx(1, "TCP receive window %s: %s", 311 errstr, optarg); 312 break; 313 case 'O': 314 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 315 if (errstr != NULL) { 316 if (strcmp(errstr, "invalid") != 0) 317 errx(1, "TCP send window %s: %s", 318 errstr, optarg); 319 } 320 break; 321 case 'S': 322 Sflag = 1; 323 break; 324 case 'T': 325 errstr = NULL; 326 errno = 0; 327 if (map_tos(optarg, &Tflag)) 328 break; 329 if (strlen(optarg) > 1 && optarg[0] == '0' && 330 optarg[1] == 'x') 331 Tflag = (int)strtol(optarg, NULL, 16); 332 else 333 Tflag = (int)strtonum(optarg, 0, 255, 334 &errstr); 335 if (Tflag < 0 || Tflag > 255 || errstr || errno) 336 errx(1, "illegal tos value %s", optarg); 337 break; 338 case FREEBSD_TUN: 339 tundev = optarg; 340 break; 341 case 0: 342 /* Long option. */ 343 break; 344 default: 345 usage(1); 346 } 347 } 348 argc -= optind; 349 argv += optind; 350 351 /* Cruft to make sure options are clean, and used properly. */ 352 if (argv[0] && !argv[1] && family == AF_UNIX) { 353 host = argv[0]; 354 uport = NULL; 355 } else if (argv[0] && !argv[1]) { 356 if (!lflag) 357 usage(1); 358 uport = argv[0]; 359 host = NULL; 360 } else if (argv[0] && argv[1]) { 361 host = argv[0]; 362 uport = argv[1]; 363 } else 364 usage(1); 365 366 if (lflag && sflag) 367 errx(1, "cannot use -s and -l"); 368 if (lflag && pflag) 369 errx(1, "cannot use -p and -l"); 370 if (lflag && zflag) 371 errx(1, "cannot use -z and -l"); 372 if (!lflag && kflag) 373 errx(1, "must use -l with -k"); 374 if (FreeBSD_sctp) { 375 if (uflag) 376 errx(1, "cannot use -u and --sctp"); 377 if (family == AF_UNIX) 378 errx(1, "cannot use -U and --sctp"); 379 } 380 if (tundev != NULL) { 381 if (!uflag) 382 errx(1, "must use --tun with -u"); 383 tun_fd = open(tundev, O_RDWR); 384 if (tun_fd == -1) 385 errx(1, "unable to open tun device %s", tundev); 386 } 387 388 /* Get name of temporary socket for unix datagram client */ 389 if ((family == AF_UNIX) && uflag && !lflag) { 390 if (sflag) { 391 unix_dg_tmp_socket = sflag; 392 } else { 393 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 394 UNIX_DG_TMP_SOCKET_SIZE); 395 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 396 err(1, "mktemp"); 397 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 398 } 399 } 400 401 /* Initialize addrinfo structure. */ 402 if (family != AF_UNIX) { 403 memset(&hints, 0, sizeof(struct addrinfo)); 404 hints.ai_family = family; 405 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 406 hints.ai_protocol = uflag ? IPPROTO_UDP : 407 FreeBSD_sctp ? IPPROTO_SCTP : IPPROTO_TCP; 408 if (nflag) 409 hints.ai_flags |= AI_NUMERICHOST; 410 } 411 412 if (xflag) { 413 if (uflag) 414 errx(1, "no proxy support for UDP mode"); 415 416 if (FreeBSD_sctp) 417 errx(1, "no proxy support for SCTP mode"); 418 419 if (lflag) 420 errx(1, "no proxy support for listen"); 421 422 if (family == AF_UNIX) 423 errx(1, "no proxy support for unix sockets"); 424 425 /* XXX IPv6 transport to proxy would probably work */ 426 if (family == AF_INET6) 427 errx(1, "no proxy support for IPv6"); 428 429 if (sflag) 430 errx(1, "no proxy support for local source address"); 431 432 proxyhost = strsep(&proxy, ":"); 433 proxyport = proxy; 434 435 memset(&proxyhints, 0, sizeof(struct addrinfo)); 436 proxyhints.ai_family = family; 437 proxyhints.ai_socktype = SOCK_STREAM; 438 proxyhints.ai_protocol = IPPROTO_TCP; 439 if (nflag) 440 proxyhints.ai_flags |= AI_NUMERICHOST; 441 } 442 443 if (lflag) { 444 int connfd; 445 ret = 0; 446 447 if (family == AF_UNIX) { 448 if (uflag) 449 s = unix_bind(host); 450 else 451 s = unix_listen(host); 452 } 453 454 /* Allow only one connection at a time, but stay alive. */ 455 for (;;) { 456 if (family != AF_UNIX) 457 s = local_listen(host, uport, hints); 458 if (s < 0) 459 err(1, NULL); 460 /* 461 * For UDP and -k, don't connect the socket, let it 462 * receive datagrams from multiple socket pairs. 463 */ 464 if (uflag && kflag) 465 readwrite(s); 466 /* 467 * For UDP and not -k, we will use recvfrom() initially 468 * to wait for a caller, then use the regular functions 469 * to talk to the caller. 470 */ 471 else if (uflag && !kflag) { 472 int rv, plen; 473 char buf[16384]; 474 struct sockaddr_storage z; 475 476 len = sizeof(z); 477 plen = 2048; 478 rv = recvfrom(s, buf, plen, MSG_PEEK, 479 (struct sockaddr *)&z, &len); 480 if (rv < 0) 481 err(1, "recvfrom"); 482 483 rv = connect(s, (struct sockaddr *)&z, len); 484 if (rv < 0) 485 err(1, "connect"); 486 487 if (vflag) 488 report_connect((struct sockaddr *)&z, len); 489 490 readwrite(s); 491 } else { 492 len = sizeof(cliaddr); 493 connfd = accept(s, (struct sockaddr *)&cliaddr, 494 &len); 495 if (connfd == -1) { 496 /* For now, all errnos are fatal */ 497 err(1, "accept"); 498 } 499 if (vflag) 500 report_connect((struct sockaddr *)&cliaddr, len); 501 502 if (FreeBSD_Mflag) 503 FreeBSD_stats_setup(connfd); 504 readwrite(connfd); 505 close(connfd); 506 } 507 508 if (family != AF_UNIX) 509 close(s); 510 else if (uflag) { 511 if (connect(s, NULL, 0) < 0) 512 err(1, "connect"); 513 } 514 515 if (!kflag) 516 break; 517 } 518 } else if (family == AF_UNIX) { 519 ret = 0; 520 521 if ((s = unix_connect(host)) > 0 && !zflag) { 522 readwrite(s); 523 close(s); 524 } else 525 ret = 1; 526 527 if (uflag) 528 unlink(unix_dg_tmp_socket); 529 exit(ret); 530 531 } else { 532 int i = 0; 533 534 /* Construct the portlist[] array. */ 535 build_ports(uport); 536 537 /* Cycle through portlist, connecting to each port. */ 538 for (i = 0; portlist[i] != NULL; i++) { 539 if (s) 540 close(s); 541 542 if (xflag) 543 s = socks_connect(host, portlist[i], hints, 544 proxyhost, proxyport, proxyhints, socksv, 545 Pflag); 546 else 547 s = remote_connect(host, portlist[i], hints); 548 549 if (s < 0) 550 continue; 551 552 ret = 0; 553 if (vflag || zflag) { 554 /* For UDP, make sure we are connected. */ 555 if (uflag) { 556 if (udptest(s) == -1) { 557 ret = 1; 558 continue; 559 } 560 } 561 562 /* Don't look up port if -n. */ 563 if (nflag) 564 sv = NULL; 565 else { 566 sv = getservbyport( 567 ntohs(atoi(portlist[i])), 568 uflag ? "udp" : "tcp"); 569 } 570 571 fprintf(stderr, 572 "Connection to %s %s port [%s/%s] " 573 "succeeded!\n", host, portlist[i], 574 uflag ? "udp" : "tcp", 575 sv ? sv->s_name : "*"); 576 } 577 if (Fflag) 578 fdpass(s); 579 else if (!zflag) 580 readwrite(s); 581 } 582 } 583 584 if (s) 585 close(s); 586 if (tun_fd != -1) 587 close(tun_fd); 588 589 exit(ret); 590 } 591 592 /* 593 * unix_bind() 594 * Returns a unix socket bound to the given path 595 */ 596 int 597 unix_bind(char *path) 598 { 599 struct sockaddr_un sun; 600 int s; 601 602 /* Create unix domain socket. */ 603 if ((s = socket(AF_UNIX, uflag ? SOCK_DGRAM : SOCK_STREAM, 604 0)) < 0) 605 return (-1); 606 607 memset(&sun, 0, sizeof(struct sockaddr_un)); 608 sun.sun_family = AF_UNIX; 609 610 if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >= 611 sizeof(sun.sun_path)) { 612 close(s); 613 errno = ENAMETOOLONG; 614 return (-1); 615 } 616 617 if (bind(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) { 618 close(s); 619 return (-1); 620 } 621 return (s); 622 } 623 624 /* 625 * unix_connect() 626 * Returns a socket connected to a local unix socket. Returns -1 on failure. 627 */ 628 int 629 unix_connect(char *path) 630 { 631 struct sockaddr_un sun; 632 int s; 633 634 if (uflag) { 635 if ((s = unix_bind(unix_dg_tmp_socket)) < 0) 636 return (-1); 637 } else { 638 if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) 639 return (-1); 640 } 641 (void)fcntl(s, F_SETFD, FD_CLOEXEC); 642 643 memset(&sun, 0, sizeof(struct sockaddr_un)); 644 sun.sun_family = AF_UNIX; 645 646 if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >= 647 sizeof(sun.sun_path)) { 648 close(s); 649 errno = ENAMETOOLONG; 650 return (-1); 651 } 652 if (connect(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) { 653 close(s); 654 return (-1); 655 } 656 return (s); 657 658 } 659 660 /* 661 * unix_listen() 662 * Create a unix domain socket, and listen on it. 663 */ 664 int 665 unix_listen(char *path) 666 { 667 int s; 668 if ((s = unix_bind(path)) < 0) 669 return (-1); 670 671 if (listen(s, 5) < 0) { 672 close(s); 673 return (-1); 674 } 675 return (s); 676 } 677 678 /* 679 * remote_connect() 680 * Returns a socket connected to a remote host. Properly binds to a local 681 * port or source address if needed. Returns -1 on failure. 682 */ 683 int 684 remote_connect(const char *host, const char *port, struct addrinfo hints) 685 { 686 struct addrinfo *res, *res0; 687 int s, error, on = 1; 688 689 if ((error = getaddrinfo(host, port, &hints, &res))) 690 errx(1, "getaddrinfo: %s", gai_strerror(error)); 691 692 res0 = res; 693 do { 694 if ((s = socket(res0->ai_family, res0->ai_socktype, 695 res0->ai_protocol)) < 0) 696 continue; 697 698 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_SETFIB, 699 &rtableid, sizeof(rtableid)) == -1)) 700 err(1, "setsockopt SO_SETFIB"); 701 702 /* Bind to a local port or source address if specified. */ 703 if (sflag || pflag) { 704 struct addrinfo ahints, *ares; 705 706 /* try IP_BINDANY, but don't insist */ 707 setsockopt(s, IPPROTO_IP, IP_BINDANY, &on, sizeof(on)); 708 memset(&ahints, 0, sizeof(struct addrinfo)); 709 ahints.ai_family = res0->ai_family; 710 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 711 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 712 ahints.ai_flags = AI_PASSIVE; 713 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 714 errx(1, "getaddrinfo: %s", gai_strerror(error)); 715 716 if (bind(s, (struct sockaddr *)ares->ai_addr, 717 ares->ai_addrlen) < 0) 718 err(1, "bind failed"); 719 freeaddrinfo(ares); 720 } 721 722 set_common_sockopts(s, res0->ai_family); 723 724 if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0) 725 break; 726 else if (vflag) 727 warn("connect to %s port %s (%s) failed", host, port, 728 uflag ? "udp" : "tcp"); 729 730 close(s); 731 s = -1; 732 } while ((res0 = res0->ai_next) != NULL); 733 734 freeaddrinfo(res); 735 736 return (s); 737 } 738 739 int 740 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 741 { 742 struct pollfd pfd; 743 socklen_t optlen; 744 int flags, optval; 745 int ret; 746 747 if (timeout != -1) { 748 flags = fcntl(s, F_GETFL, 0); 749 if (fcntl(s, F_SETFL, flags | O_NONBLOCK) == -1) 750 err(1, "set non-blocking mode"); 751 } 752 753 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 754 pfd.fd = s; 755 pfd.events = POLLOUT; 756 if ((ret = poll(&pfd, 1, timeout)) == 1) { 757 optlen = sizeof(optval); 758 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 759 &optval, &optlen)) == 0) { 760 errno = optval; 761 ret = optval == 0 ? 0 : -1; 762 } 763 } else if (ret == 0) { 764 errno = ETIMEDOUT; 765 ret = -1; 766 } else 767 err(1, "poll failed"); 768 } 769 770 if (timeout != -1 && fcntl(s, F_SETFL, flags) == -1) 771 err(1, "restoring flags"); 772 773 return (ret); 774 } 775 776 /* 777 * local_listen() 778 * Returns a socket listening on a local port, binds to specified source 779 * address. Returns -1 on failure. 780 */ 781 int 782 local_listen(char *host, char *port, struct addrinfo hints) 783 { 784 struct addrinfo *res, *res0; 785 int s, ret, x = 1; 786 int error; 787 788 /* Allow nodename to be null. */ 789 hints.ai_flags |= AI_PASSIVE; 790 791 /* 792 * In the case of binding to a wildcard address 793 * default to binding to an ipv4 address. 794 */ 795 if (host == NULL && hints.ai_family == AF_UNSPEC) 796 hints.ai_family = AF_INET; 797 798 if ((error = getaddrinfo(host, port, &hints, &res))) 799 errx(1, "getaddrinfo: %s", gai_strerror(error)); 800 801 res0 = res; 802 do { 803 if ((s = socket(res0->ai_family, res0->ai_socktype, 804 res0->ai_protocol)) < 0) 805 continue; 806 807 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_SETFIB, 808 &rtableid, sizeof(rtableid)) == -1)) 809 err(1, "setsockopt SO_SETFIB"); 810 811 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 812 if (ret == -1) 813 err(1, NULL); 814 815 if (FreeBSD_Oflag) { 816 if (setsockopt(s, IPPROTO_TCP, TCP_NOOPT, 817 &FreeBSD_Oflag, sizeof(FreeBSD_Oflag)) == -1) 818 err(1, "disable TCP options"); 819 } 820 821 set_common_sockopts(s, res0->ai_family); 822 823 if (bind(s, (struct sockaddr *)res0->ai_addr, 824 res0->ai_addrlen) == 0) 825 break; 826 827 close(s); 828 s = -1; 829 } while ((res0 = res0->ai_next) != NULL); 830 831 if (!uflag && s != -1) { 832 if (listen(s, 1) < 0) 833 err(1, "listen"); 834 } 835 836 freeaddrinfo(res); 837 838 return (s); 839 } 840 841 /* 842 * readwrite() 843 * Loop that polls on the network file descriptor and stdin. 844 */ 845 void 846 readwrite(int net_fd) 847 { 848 struct pollfd pfd[4]; 849 int stdin_fd = STDIN_FILENO; 850 int stdout_fd = STDOUT_FILENO; 851 unsigned char netinbuf[BUFSIZE]; 852 size_t netinbufpos = 0; 853 unsigned char stdinbuf[BUFSIZE]; 854 size_t stdinbufpos = 0; 855 int n, num_fds; 856 int stats_printed = 0; 857 ssize_t ret; 858 859 /* don't read from stdin if requested */ 860 if (dflag) 861 stdin_fd = -1; 862 863 /* stdin */ 864 pfd[POLL_STDIN].fd = (tun_fd != -1) ? tun_fd : stdin_fd; 865 pfd[POLL_STDIN].events = POLLIN; 866 867 /* network out */ 868 pfd[POLL_NETOUT].fd = net_fd; 869 pfd[POLL_NETOUT].events = 0; 870 871 /* network in */ 872 pfd[POLL_NETIN].fd = net_fd; 873 pfd[POLL_NETIN].events = POLLIN; 874 875 /* stdout */ 876 pfd[POLL_STDOUT].fd = (tun_fd != -1) ? tun_fd : stdout_fd; 877 pfd[POLL_STDOUT].events = 0; 878 879 while (1) { 880 /* both inputs are gone, buffers are empty, we are done */ 881 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 882 && stdinbufpos == 0 && netinbufpos == 0) { 883 if (FreeBSD_Mflag && !stats_printed) 884 FreeBSD_stats_print(net_fd); 885 close(net_fd); 886 return; 887 } 888 /* both outputs are gone, we can't continue */ 889 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 890 if (FreeBSD_Mflag && !stats_printed) 891 FreeBSD_stats_print(net_fd); 892 close(net_fd); 893 return; 894 } 895 /* listen and net in gone, queues empty, done */ 896 if (lflag && pfd[POLL_NETIN].fd == -1 897 && stdinbufpos == 0 && netinbufpos == 0) { 898 if (FreeBSD_Mflag && !stats_printed) 899 FreeBSD_stats_print(net_fd); 900 close(net_fd); 901 return; 902 } 903 904 /* help says -i is for "wait between lines sent". We read and 905 * write arbitrary amounts of data, and we don't want to start 906 * scanning for newlines, so this is as good as it gets */ 907 if (iflag) 908 sleep(iflag); 909 910 /* poll */ 911 num_fds = poll(pfd, 4, timeout); 912 913 /* treat poll errors */ 914 if (num_fds == -1) { 915 close(net_fd); 916 err(1, "polling error"); 917 } 918 919 /* timeout happened */ 920 if (num_fds == 0) { 921 if (FreeBSD_Mflag) 922 FreeBSD_stats_print(net_fd); 923 return; 924 } 925 926 /* treat socket error conditions */ 927 for (n = 0; n < 4; n++) { 928 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 929 pfd[n].fd = -1; 930 } 931 } 932 /* reading is possible after HUP */ 933 if (pfd[POLL_STDIN].events & POLLIN && 934 pfd[POLL_STDIN].revents & POLLHUP && 935 ! (pfd[POLL_STDIN].revents & POLLIN)) 936 pfd[POLL_STDIN].fd = -1; 937 938 if (pfd[POLL_NETIN].events & POLLIN && 939 pfd[POLL_NETIN].revents & POLLHUP && 940 ! (pfd[POLL_NETIN].revents & POLLIN)) 941 pfd[POLL_NETIN].fd = -1; 942 943 if (pfd[POLL_NETOUT].revents & POLLHUP) { 944 if (Nflag) 945 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 946 pfd[POLL_NETOUT].fd = -1; 947 } 948 /* if HUP, stop watching stdout */ 949 if (pfd[POLL_STDOUT].revents & POLLHUP) 950 pfd[POLL_STDOUT].fd = -1; 951 /* if no net out, stop watching stdin */ 952 if (pfd[POLL_NETOUT].fd == -1) 953 pfd[POLL_STDIN].fd = -1; 954 /* if no stdout, stop watching net in */ 955 if (pfd[POLL_STDOUT].fd == -1) { 956 if (pfd[POLL_NETIN].fd != -1) 957 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 958 pfd[POLL_NETIN].fd = -1; 959 } 960 961 /* try to read from stdin */ 962 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 963 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 964 &stdinbufpos); 965 /* error or eof on stdin - remove from pfd */ 966 if (ret == 0 || ret == -1) 967 pfd[POLL_STDIN].fd = -1; 968 /* read something - poll net out */ 969 if (stdinbufpos > 0) 970 pfd[POLL_NETOUT].events = POLLOUT; 971 /* filled buffer - remove self from polling */ 972 if (stdinbufpos == BUFSIZE) 973 pfd[POLL_STDIN].events = 0; 974 } 975 /* try to write to network */ 976 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 977 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 978 &stdinbufpos, FreeBSD_crlf); 979 if (ret == -1) 980 pfd[POLL_NETOUT].fd = -1; 981 /* buffer empty - remove self from polling */ 982 if (stdinbufpos == 0) 983 pfd[POLL_NETOUT].events = 0; 984 /* buffer no longer full - poll stdin again */ 985 if (stdinbufpos < BUFSIZE) 986 pfd[POLL_STDIN].events = POLLIN; 987 } 988 /* try to read from network */ 989 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 990 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 991 &netinbufpos); 992 if (ret == -1) 993 pfd[POLL_NETIN].fd = -1; 994 /* eof on net in - remove from pfd */ 995 if (ret == 0) { 996 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 997 pfd[POLL_NETIN].fd = -1; 998 } 999 /* read something - poll stdout */ 1000 if (netinbufpos > 0) 1001 pfd[POLL_STDOUT].events = POLLOUT; 1002 /* filled buffer - remove self from polling */ 1003 if (netinbufpos == BUFSIZE) 1004 pfd[POLL_NETIN].events = 0; 1005 /* handle telnet */ 1006 if (tflag) 1007 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1008 netinbufpos); 1009 } 1010 /* try to write to stdout */ 1011 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1012 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1013 &netinbufpos, 0); 1014 if (ret == -1) 1015 pfd[POLL_STDOUT].fd = -1; 1016 /* buffer empty - remove self from polling */ 1017 if (netinbufpos == 0) 1018 pfd[POLL_STDOUT].events = 0; 1019 /* buffer no longer full - poll net in again */ 1020 if (netinbufpos < BUFSIZE) 1021 pfd[POLL_NETIN].events = POLLIN; 1022 } 1023 1024 /* stdin gone and queue empty? */ 1025 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1026 if (pfd[POLL_NETOUT].fd != -1 && Nflag) { 1027 if (FreeBSD_Mflag) { 1028 FreeBSD_stats_print(net_fd); 1029 stats_printed = 1; 1030 } 1031 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1032 } 1033 pfd[POLL_NETOUT].fd = -1; 1034 } 1035 /* net in gone and queue empty? */ 1036 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1037 pfd[POLL_STDOUT].fd = -1; 1038 } 1039 } 1040 } 1041 1042 ssize_t 1043 write_wrapper(int fd, const void *buf, size_t buflen) 1044 { 1045 ssize_t n = write(fd, buf, buflen); 1046 /* don't treat EAGAIN, EINTR as error */ 1047 return (n == -1 && (errno == EAGAIN || errno == EINTR)) ? -2 : n; 1048 } 1049 1050 ssize_t 1051 drainbuf(int fd, unsigned char *buf, size_t *bufpos, int crlf) 1052 { 1053 ssize_t n = *bufpos, n2 = 0; 1054 ssize_t adjust; 1055 unsigned char *lf = NULL; 1056 1057 if (crlf) { 1058 lf = memchr(buf, '\n', *bufpos); 1059 if (lf && (lf == buf || *(lf - 1) != '\r')) 1060 n = lf - buf; 1061 else 1062 lf = NULL; 1063 } 1064 1065 if (n != 0) { 1066 n = write_wrapper(fd, buf, n); 1067 if (n <= 0) 1068 return n; 1069 } 1070 1071 if (lf) { 1072 n2 = write_wrapper(fd, "\r\n", 2); 1073 if (n2 <= 0) 1074 return n2; 1075 n += 1; 1076 } 1077 1078 /* adjust buffer */ 1079 adjust = *bufpos - n; 1080 if (adjust > 0) 1081 memmove(buf, buf + n, adjust); 1082 *bufpos -= n; 1083 return n; 1084 } 1085 1086 1087 ssize_t 1088 fillbuf(int fd, unsigned char *buf, size_t *bufpos) 1089 { 1090 size_t num = BUFSIZE - *bufpos; 1091 ssize_t n; 1092 1093 n = read(fd, buf + *bufpos, num); 1094 /* don't treat EAGAIN, EINTR as error */ 1095 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1096 n = -2; 1097 if (n <= 0) 1098 return n; 1099 *bufpos += n; 1100 return n; 1101 } 1102 1103 /* 1104 * fdpass() 1105 * Pass the connected file descriptor to stdout and exit. 1106 */ 1107 void 1108 fdpass(int nfd) 1109 { 1110 struct msghdr mh; 1111 union { 1112 struct cmsghdr hdr; 1113 char buf[CMSG_SPACE(sizeof(int))]; 1114 } cmsgbuf; 1115 struct cmsghdr *cmsg; 1116 struct iovec iov; 1117 char c = '\0'; 1118 ssize_t r; 1119 struct pollfd pfd; 1120 1121 /* Avoid obvious stupidity */ 1122 if (isatty(STDOUT_FILENO)) 1123 errx(1, "Cannot pass file descriptor to tty"); 1124 1125 bzero(&mh, sizeof(mh)); 1126 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1127 bzero(&iov, sizeof(iov)); 1128 1129 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1130 mh.msg_controllen = sizeof(cmsgbuf.buf); 1131 cmsg = CMSG_FIRSTHDR(&mh); 1132 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1133 cmsg->cmsg_level = SOL_SOCKET; 1134 cmsg->cmsg_type = SCM_RIGHTS; 1135 *(int *)CMSG_DATA(cmsg) = nfd; 1136 1137 iov.iov_base = &c; 1138 iov.iov_len = 1; 1139 mh.msg_iov = &iov; 1140 mh.msg_iovlen = 1; 1141 1142 bzero(&pfd, sizeof(pfd)); 1143 pfd.fd = STDOUT_FILENO; 1144 pfd.events = POLLOUT; 1145 for (;;) { 1146 r = sendmsg(STDOUT_FILENO, &mh, 0); 1147 if (r == -1) { 1148 if (errno == EAGAIN || errno == EINTR) { 1149 if (poll(&pfd, 1, -1) == -1) 1150 err(1, "poll"); 1151 continue; 1152 } 1153 err(1, "sendmsg"); 1154 } else if (r != 1) 1155 errx(1, "sendmsg: unexpected return value %zd", r); 1156 else 1157 break; 1158 } 1159 exit(0); 1160 } 1161 1162 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1163 void 1164 atelnet(int nfd, unsigned char *buf, unsigned int size) 1165 { 1166 unsigned char *p, *end; 1167 unsigned char obuf[4]; 1168 1169 if (size < 3) 1170 return; 1171 end = buf + size - 2; 1172 1173 for (p = buf; p < end; p++) { 1174 if (*p != IAC) 1175 continue; 1176 1177 obuf[0] = IAC; 1178 p++; 1179 if ((*p == WILL) || (*p == WONT)) 1180 obuf[1] = DONT; 1181 else if ((*p == DO) || (*p == DONT)) 1182 obuf[1] = WONT; 1183 else 1184 continue; 1185 1186 p++; 1187 obuf[2] = *p; 1188 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1189 warn("Write Error!"); 1190 } 1191 } 1192 1193 /* 1194 * build_ports() 1195 * Build an array of ports in portlist[], listing each port 1196 * that we should try to connect to. 1197 */ 1198 void 1199 build_ports(char *p) 1200 { 1201 const char *errstr; 1202 char *n; 1203 int hi, lo, cp; 1204 int x = 0; 1205 1206 if ((n = strchr(p, '-')) != NULL) { 1207 *n = '\0'; 1208 n++; 1209 1210 /* Make sure the ports are in order: lowest->highest. */ 1211 hi = strtonum(n, 1, PORT_MAX, &errstr); 1212 if (errstr) 1213 errx(1, "port number %s: %s", errstr, n); 1214 lo = strtonum(p, 1, PORT_MAX, &errstr); 1215 if (errstr) 1216 errx(1, "port number %s: %s", errstr, p); 1217 1218 if (lo > hi) { 1219 cp = hi; 1220 hi = lo; 1221 lo = cp; 1222 } 1223 1224 /* Load ports sequentially. */ 1225 for (cp = lo; cp <= hi; cp++) { 1226 portlist[x] = calloc(1, PORT_MAX_LEN); 1227 if (portlist[x] == NULL) 1228 err(1, NULL); 1229 snprintf(portlist[x], PORT_MAX_LEN, "%d", cp); 1230 x++; 1231 } 1232 1233 /* Randomly swap ports. */ 1234 if (rflag) { 1235 int y; 1236 char *c; 1237 1238 for (x = 0; x <= (hi - lo); x++) { 1239 y = (arc4random() & 0xFFFF) % (hi - lo); 1240 c = portlist[x]; 1241 portlist[x] = portlist[y]; 1242 portlist[y] = c; 1243 } 1244 } 1245 } else { 1246 hi = strtonum(p, 1, PORT_MAX, &errstr); 1247 if (errstr) 1248 errx(1, "port number %s: %s", errstr, p); 1249 portlist[0] = strdup(p); 1250 if (portlist[0] == NULL) 1251 err(1, NULL); 1252 } 1253 } 1254 1255 /* 1256 * udptest() 1257 * Do a few writes to see if the UDP port is there. 1258 * Fails once PF state table is full. 1259 */ 1260 int 1261 udptest(int s) 1262 { 1263 int i, ret; 1264 1265 for (i = 0; i <= 3; i++) { 1266 if (write(s, "X", 1) == 1) 1267 ret = 1; 1268 else 1269 ret = -1; 1270 } 1271 return (ret); 1272 } 1273 1274 void 1275 FreeBSD_stats_setup(int s) 1276 { 1277 1278 if (setsockopt(s, IPPROTO_TCP, TCP_STATS, 1279 &FreeBSD_Mflag, sizeof(FreeBSD_Mflag)) == -1) { 1280 if (errno == EOPNOTSUPP) { 1281 warnx("getsockopt(TCP_STATS) failed; " 1282 "kernel built without \"options STATS\"?"); 1283 } 1284 err(1, "enable TCP_STATS gathering"); 1285 } 1286 } 1287 1288 void 1289 FreeBSD_stats_print(int s) 1290 { 1291 #ifdef WITH_STATS 1292 struct statsblob *statsb; 1293 struct sbuf *sb; 1294 socklen_t sockoptlen; 1295 int error; 1296 1297 /* 1298 * This usleep is a workaround for TCP_STATS reporting 1299 * incorrect values for TXPB. 1300 */ 1301 usleep(100000); 1302 1303 sockoptlen = 2048; 1304 statsb = malloc(sockoptlen); 1305 if (statsb == NULL) 1306 err(1, "malloc"); 1307 error = getsockopt(s, IPPROTO_TCP, TCP_STATS, statsb, &sockoptlen); 1308 if (error != 0) { 1309 if (errno == EOVERFLOW && statsb->cursz > sockoptlen) { 1310 /* Retry with a larger size. */ 1311 sockoptlen = statsb->cursz; 1312 statsb = realloc(statsb, sockoptlen); 1313 if (statsb == NULL) 1314 err(1, "realloc"); 1315 error = getsockopt(s, IPPROTO_TCP, TCP_STATS, 1316 statsb, &sockoptlen); 1317 } 1318 if (error != 0) 1319 err(1, "getsockopt"); 1320 } 1321 1322 sb = sbuf_new_auto(); 1323 error = stats_blob_tostr(statsb, sb, SB_STRFMT_JSON, SB_TOSTR_META); 1324 if (error != 0) 1325 errc(1, error, "stats_blob_tostr"); 1326 1327 error = sbuf_finish(sb); 1328 if (error != 0) 1329 err(1, "sbuf_finish"); 1330 1331 fprintf(stderr, "%s\n", sbuf_data(sb)); 1332 #endif 1333 } 1334 1335 void 1336 set_common_sockopts(int s, int af) 1337 { 1338 int x = 1; 1339 1340 if (Sflag) { 1341 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1342 &x, sizeof(x)) == -1) 1343 err(1, NULL); 1344 } 1345 if (Dflag) { 1346 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1347 &x, sizeof(x)) == -1) 1348 err(1, NULL); 1349 } 1350 if (Tflag != -1) { 1351 int proto, option; 1352 1353 if (af == AF_INET6) { 1354 proto = IPPROTO_IPV6; 1355 option = IPV6_TCLASS; 1356 } else { 1357 proto = IPPROTO_IP; 1358 option = IP_TOS; 1359 } 1360 1361 if (setsockopt(s, proto, option, &Tflag, sizeof(Tflag)) == -1) 1362 err(1, "set IP ToS"); 1363 } 1364 if (Iflag) { 1365 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1366 &Iflag, sizeof(Iflag)) == -1) 1367 err(1, "set TCP receive buffer size"); 1368 } 1369 if (Oflag) { 1370 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1371 &Oflag, sizeof(Oflag)) == -1) 1372 err(1, "set TCP send buffer size"); 1373 } 1374 if (FreeBSD_Oflag) { 1375 if (setsockopt(s, IPPROTO_TCP, TCP_NOOPT, 1376 &FreeBSD_Oflag, sizeof(FreeBSD_Oflag)) == -1) 1377 err(1, "disable TCP options"); 1378 } 1379 if (FreeBSD_Mflag) 1380 FreeBSD_stats_setup(s); 1381 #ifdef IPSEC 1382 if (ipsec_policy[0] != NULL) 1383 add_ipsec_policy(s, af, ipsec_policy[0]); 1384 if (ipsec_policy[1] != NULL) 1385 add_ipsec_policy(s, af, ipsec_policy[1]); 1386 #endif 1387 } 1388 1389 int 1390 map_tos(char *s, int *val) 1391 { 1392 /* DiffServ Codepoints and other TOS mappings */ 1393 const struct toskeywords { 1394 const char *keyword; 1395 int val; 1396 } *t, toskeywords[] = { 1397 { "af11", IPTOS_DSCP_AF11 }, 1398 { "af12", IPTOS_DSCP_AF12 }, 1399 { "af13", IPTOS_DSCP_AF13 }, 1400 { "af21", IPTOS_DSCP_AF21 }, 1401 { "af22", IPTOS_DSCP_AF22 }, 1402 { "af23", IPTOS_DSCP_AF23 }, 1403 { "af31", IPTOS_DSCP_AF31 }, 1404 { "af32", IPTOS_DSCP_AF32 }, 1405 { "af33", IPTOS_DSCP_AF33 }, 1406 { "af41", IPTOS_DSCP_AF41 }, 1407 { "af42", IPTOS_DSCP_AF42 }, 1408 { "af43", IPTOS_DSCP_AF43 }, 1409 { "critical", IPTOS_PREC_CRITIC_ECP }, 1410 { "cs0", IPTOS_DSCP_CS0 }, 1411 { "cs1", IPTOS_DSCP_CS1 }, 1412 { "cs2", IPTOS_DSCP_CS2 }, 1413 { "cs3", IPTOS_DSCP_CS3 }, 1414 { "cs4", IPTOS_DSCP_CS4 }, 1415 { "cs5", IPTOS_DSCP_CS5 }, 1416 { "cs6", IPTOS_DSCP_CS6 }, 1417 { "cs7", IPTOS_DSCP_CS7 }, 1418 { "ef", IPTOS_DSCP_EF }, 1419 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1420 { "lowdelay", IPTOS_LOWDELAY }, 1421 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1422 { "reliability", IPTOS_RELIABILITY }, 1423 { "throughput", IPTOS_THROUGHPUT }, 1424 { NULL, -1 }, 1425 }; 1426 1427 for (t = toskeywords; t->keyword != NULL; t++) { 1428 if (strcmp(s, t->keyword) == 0) { 1429 *val = t->val; 1430 return (1); 1431 } 1432 } 1433 1434 return (0); 1435 } 1436 1437 void 1438 report_connect(const struct sockaddr *sa, socklen_t salen) 1439 { 1440 char remote_host[NI_MAXHOST]; 1441 char remote_port[NI_MAXSERV]; 1442 int herr; 1443 int flags = NI_NUMERICSERV; 1444 1445 if (nflag) 1446 flags |= NI_NUMERICHOST; 1447 1448 if ((herr = getnameinfo(sa, salen, 1449 remote_host, sizeof(remote_host), 1450 remote_port, sizeof(remote_port), 1451 flags)) != 0) { 1452 if (herr == EAI_SYSTEM) 1453 err(1, "getnameinfo"); 1454 else 1455 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1456 } 1457 1458 fprintf(stderr, 1459 "Connection from %s %s " 1460 "received!\n", remote_host, remote_port); 1461 } 1462 1463 void 1464 help(void) 1465 { 1466 usage(0); 1467 fprintf(stderr, "\tCommand Summary:\n\ 1468 \t-4 Use IPv4\n\ 1469 \t-6 Use IPv6\n\ 1470 \t--crlf Convert LF into CRLF when sending data over the network\n\ 1471 \t-D Enable the debug socket option\n\ 1472 \t-d Detach from stdin\n"); 1473 #ifdef IPSEC 1474 fprintf(stderr, "\ 1475 \t-E Use IPsec ESP\n\ 1476 \t-e policy Use specified IPsec policy\n"); 1477 #endif 1478 fprintf(stderr, "\ 1479 \t-F Pass socket fd\n\ 1480 \t-h This help text\n\ 1481 \t-I length TCP receive buffer length\n\ 1482 \t-i secs\t Delay interval for lines sent, ports scanned\n\ 1483 \t-k Keep inbound sockets open for multiple connects\n\ 1484 \t-l Listen mode, for inbound connects\n\ 1485 \t-N Shutdown the network socket after EOF on stdin\n\ 1486 \t-n Suppress name/port resolutions\n\ 1487 \t--no-tcpopt Disable TCP options\n\ 1488 \t--sctp\t SCTP mode\n\ 1489 \t--tun tundev Use tun device rather than stdio\n\ 1490 \t-O length TCP send buffer length\n\ 1491 \t-P proxyuser\tUsername for proxy authentication\n\ 1492 \t-p port\t Specify local port for remote connects\n\ 1493 \t-r Randomize remote ports\n\ 1494 \t-S Enable the TCP MD5 signature option\n\ 1495 \t-s addr\t Local source address\n\ 1496 \t-T toskeyword\tSet IP Type of Service\n\ 1497 \t-t Answer TELNET negotiation\n\ 1498 \t-U Use UNIX domain socket\n\ 1499 \t-u UDP mode\n\ 1500 \t-V rtable Specify alternate routing table\n\ 1501 \t-v Verbose\n\ 1502 \t-w secs\t Timeout for connects and final net reads\n\ 1503 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1504 \t-x addr[:port]\tSpecify proxy address and port\n\ 1505 \t-z Zero-I/O mode [used for scanning]\n\ 1506 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1507 #ifdef IPSEC 1508 fprintf(stderr, "\tSee ipsec_set_policy(3) for -e argument format\n"); 1509 #endif 1510 exit(1); 1511 } 1512 1513 #ifdef IPSEC 1514 void 1515 add_ipsec_policy(int s, int af, char *policy) 1516 { 1517 char *raw; 1518 int e; 1519 1520 raw = ipsec_set_policy(policy, strlen(policy)); 1521 if (raw == NULL) 1522 errx(1, "ipsec_set_policy `%s': %s", policy, 1523 ipsec_strerror()); 1524 if (af == AF_INET) 1525 e = setsockopt(s, IPPROTO_IP, IP_IPSEC_POLICY, raw, 1526 ipsec_get_policylen(raw)); 1527 if (af == AF_INET6) 1528 e = setsockopt(s, IPPROTO_IPV6, IPV6_IPSEC_POLICY, raw, 1529 ipsec_get_policylen(raw)); 1530 if (e < 0) 1531 err(1, "ipsec policy cannot be configured"); 1532 free(raw); 1533 if (vflag) 1534 fprintf(stderr, "ipsec policy configured: `%s'\n", policy); 1535 return; 1536 } 1537 #endif /* IPSEC */ 1538 1539 void 1540 usage(int ret) 1541 { 1542 fprintf(stderr, 1543 #ifdef IPSEC 1544 "usage: nc [-46DdEFhklNnrStUuvz] [-e policy] [-I length] [-i interval] [-O length]\n" 1545 #else 1546 "usage: nc [-46DdFhklNnrStUuvz] [-I length] [-i interval] [-O length]\n" 1547 #endif 1548 "\t [--no-tcpopt] [--sctp]\n" 1549 "\t [-P proxy_username] [-p source_port] [-s source] [-T ToS]\n" 1550 "\t [--tun tundev] [-V rtable] [-w timeout] [-X proxy_protocol]\n" 1551 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1552 if (ret) 1553 exit(1); 1554 } 1555