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_lb; /* Use SO_REUSEPORT_LB */ 93 int FreeBSD_Mflag; /* Measure using stats(3) */ 94 int Nflag; /* shutdown() network socket */ 95 int nflag; /* Don't do name look up */ 96 int FreeBSD_Oflag; /* Do not use TCP options */ 97 int FreeBSD_sctp; /* Use SCTP */ 98 int FreeBSD_crlf; /* Convert LF to CRLF */ 99 char *Pflag; /* Proxy username */ 100 char *pflag; /* Localport flag */ 101 int rflag; /* Random ports flag */ 102 char *sflag; /* Source Address */ 103 int tflag; /* Telnet Emulation */ 104 int uflag; /* UDP - Default to TCP */ 105 int vflag; /* Verbosity */ 106 int xflag; /* Socks proxy */ 107 int zflag; /* Port Scan Flag */ 108 int Dflag; /* sodebug */ 109 int Iflag; /* TCP receive buffer size */ 110 int Oflag; /* TCP send buffer size */ 111 int Sflag; /* TCP MD5 signature option */ 112 int Tflag = -1; /* IP Type of Service */ 113 int rtableid = -1; 114 115 int timeout = -1; 116 int family = AF_UNSPEC; 117 int tun_fd = -1; 118 char *portlist[PORT_MAX+1]; 119 char *unix_dg_tmp_socket; 120 121 void atelnet(int, unsigned char *, unsigned int); 122 void build_ports(char *); 123 void help(void); 124 int local_listen(char *, char *, struct addrinfo); 125 void readwrite(int); 126 void fdpass(int nfd) __attribute__((noreturn)); 127 int remote_connect(const char *, const char *, struct addrinfo); 128 int timeout_connect(int, const struct sockaddr *, socklen_t); 129 int socks_connect(const char *, const char *, struct addrinfo, 130 const char *, const char *, struct addrinfo, int, const char *); 131 int udptest(int); 132 int unix_bind(char *); 133 int unix_connect(char *); 134 int unix_listen(char *); 135 void FreeBSD_stats_setup(int); 136 void FreeBSD_stats_print(int); 137 void set_common_sockopts(int, int); 138 int map_tos(char *, int *); 139 void report_connect(const struct sockaddr *, socklen_t); 140 void usage(int); 141 ssize_t write_wrapper(int, const void *, size_t); 142 ssize_t drainbuf(int, unsigned char *, size_t *, int); 143 ssize_t fillbuf(int, unsigned char *, size_t *); 144 145 #ifdef IPSEC 146 void add_ipsec_policy(int, int, char *); 147 148 char *ipsec_policy[2]; 149 #endif 150 151 enum { 152 FREEBSD_TUN = CHAR_MAX, /* avoid collision with return values from getopt */ 153 }; 154 155 int 156 main(int argc, char *argv[]) 157 { 158 int ch, s, ret, socksv, ipsec_count; 159 int numfibs; 160 size_t intsize = sizeof(int); 161 char *host, *uport; 162 struct addrinfo hints; 163 struct servent *sv; 164 socklen_t len; 165 struct sockaddr_storage cliaddr; 166 char *proxy; 167 const char *errstr, *proxyhost = "", *proxyport = NULL, *tundev = NULL; 168 struct addrinfo proxyhints; 169 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 170 struct option longopts[] = { 171 { "crlf", no_argument, &FreeBSD_crlf, 1 }, 172 { "lb", no_argument, &FreeBSD_lb, 1 }, 173 { "no-tcpopt", no_argument, &FreeBSD_Oflag, 1 }, 174 { "sctp", no_argument, &FreeBSD_sctp, 1 }, 175 { "tun", required_argument, NULL, FREEBSD_TUN }, 176 { NULL, 0, NULL, 0 } 177 }; 178 179 ret = 1; 180 ipsec_count = 0; 181 s = 0; 182 socksv = 5; 183 host = NULL; 184 uport = NULL; 185 sv = NULL; 186 187 signal(SIGPIPE, SIG_IGN); 188 189 while ((ch = getopt_long(argc, argv, 190 "46DdEe:FhI:i:klMNnoO:P:p:rSs:tT:UuV:vw:X:x:z", 191 longopts, NULL)) != -1) { 192 switch (ch) { 193 case '4': 194 family = AF_INET; 195 break; 196 case '6': 197 family = AF_INET6; 198 break; 199 case 'U': 200 family = AF_UNIX; 201 break; 202 case 'X': 203 if (strcasecmp(optarg, "connect") == 0) 204 socksv = -1; /* HTTP proxy CONNECT */ 205 else if (strcmp(optarg, "4") == 0) 206 socksv = 4; /* SOCKS v.4 */ 207 else if (strcmp(optarg, "5") == 0) 208 socksv = 5; /* SOCKS v.5 */ 209 else 210 errx(1, "unsupported proxy protocol"); 211 break; 212 case 'd': 213 dflag = 1; 214 break; 215 case 'e': 216 #ifdef IPSEC 217 ipsec_policy[ipsec_count++ % 2] = optarg; 218 #else 219 errx(1, "IPsec support unavailable."); 220 #endif 221 break; 222 case 'E': 223 #ifdef IPSEC 224 ipsec_policy[0] = "in ipsec esp/transport//require"; 225 ipsec_policy[1] = "out ipsec esp/transport//require"; 226 #else 227 errx(1, "IPsec support unavailable."); 228 #endif 229 break; 230 case 'F': 231 Fflag = 1; 232 break; 233 case 'h': 234 help(); 235 break; 236 case 'i': 237 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 238 if (errstr) 239 errx(1, "interval %s: %s", errstr, optarg); 240 break; 241 case 'k': 242 kflag = 1; 243 break; 244 case 'l': 245 lflag = 1; 246 break; 247 case 'M': 248 #ifndef WITH_STATS 249 errx(1, "-M requires stats(3) support"); 250 #else 251 FreeBSD_Mflag = 1; 252 #endif 253 break; 254 case 'N': 255 Nflag = 1; 256 break; 257 case 'n': 258 nflag = 1; 259 break; 260 case 'o': 261 fprintf(stderr, "option -o is deprecated.\n"); 262 break; 263 case 'P': 264 Pflag = optarg; 265 break; 266 case 'p': 267 pflag = optarg; 268 break; 269 case 'r': 270 rflag = 1; 271 break; 272 case 's': 273 sflag = optarg; 274 break; 275 case 't': 276 tflag = 1; 277 break; 278 case 'u': 279 uflag = 1; 280 break; 281 case 'V': 282 if (sysctlbyname("net.fibs", &numfibs, &intsize, NULL, 0) == -1) 283 errx(1, "Multiple FIBS not supported"); 284 rtableid = (int)strtonum(optarg, 0, 285 numfibs - 1, &errstr); 286 if (errstr) 287 errx(1, "rtable %s: %s", errstr, optarg); 288 break; 289 case 'v': 290 vflag = 1; 291 break; 292 case 'w': 293 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 294 if (errstr) 295 errx(1, "timeout %s: %s", errstr, optarg); 296 timeout *= 1000; 297 break; 298 case 'x': 299 xflag = 1; 300 if ((proxy = strdup(optarg)) == NULL) 301 err(1, NULL); 302 break; 303 case 'z': 304 zflag = 1; 305 break; 306 case 'D': 307 Dflag = 1; 308 break; 309 case 'I': 310 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 311 if (errstr != NULL) 312 errx(1, "TCP receive window %s: %s", 313 errstr, optarg); 314 break; 315 case 'O': 316 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 317 if (errstr != NULL) { 318 if (strcmp(errstr, "invalid") != 0) 319 errx(1, "TCP send window %s: %s", 320 errstr, optarg); 321 } 322 break; 323 case 'S': 324 Sflag = 1; 325 break; 326 case 'T': 327 errstr = NULL; 328 errno = 0; 329 if (map_tos(optarg, &Tflag)) 330 break; 331 if (strlen(optarg) > 1 && optarg[0] == '0' && 332 optarg[1] == 'x') 333 Tflag = (int)strtol(optarg, NULL, 16); 334 else 335 Tflag = (int)strtonum(optarg, 0, 255, 336 &errstr); 337 if (Tflag < 0 || Tflag > 255 || errstr || errno) 338 errx(1, "illegal tos value %s", optarg); 339 break; 340 case FREEBSD_TUN: 341 tundev = optarg; 342 break; 343 case 0: 344 /* Long option. */ 345 break; 346 default: 347 usage(1); 348 } 349 } 350 argc -= optind; 351 argv += optind; 352 353 /* Cruft to make sure options are clean, and used properly. */ 354 if (argv[0] && !argv[1] && family == AF_UNIX) { 355 host = argv[0]; 356 uport = NULL; 357 } else if (argv[0] && !argv[1]) { 358 if (!lflag) 359 usage(1); 360 uport = argv[0]; 361 host = NULL; 362 } else if (argv[0] && argv[1]) { 363 host = argv[0]; 364 uport = argv[1]; 365 } else 366 usage(1); 367 368 if (lflag && sflag) 369 errx(1, "cannot use -s and -l"); 370 if (lflag && pflag) 371 errx(1, "cannot use -p and -l"); 372 if (lflag && zflag) 373 errx(1, "cannot use -z and -l"); 374 if (!lflag && kflag) 375 errx(1, "must use -l with -k"); 376 if (!lflag && FreeBSD_lb) 377 errx(1, "must use -l with --lb"); 378 if (FreeBSD_sctp) { 379 if (uflag) 380 errx(1, "cannot use -u and --sctp"); 381 if (family == AF_UNIX) 382 errx(1, "cannot use -U and --sctp"); 383 } 384 if (tundev != NULL) { 385 if (!uflag) 386 errx(1, "must use --tun with -u"); 387 tun_fd = open(tundev, O_RDWR); 388 if (tun_fd == -1) 389 errx(1, "unable to open tun device %s", tundev); 390 } 391 392 /* Get name of temporary socket for unix datagram client */ 393 if ((family == AF_UNIX) && uflag && !lflag) { 394 if (sflag) { 395 unix_dg_tmp_socket = sflag; 396 } else { 397 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 398 UNIX_DG_TMP_SOCKET_SIZE); 399 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 400 err(1, "mktemp"); 401 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 402 } 403 } 404 405 /* Initialize addrinfo structure. */ 406 if (family != AF_UNIX) { 407 memset(&hints, 0, sizeof(struct addrinfo)); 408 hints.ai_family = family; 409 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 410 hints.ai_protocol = uflag ? IPPROTO_UDP : 411 FreeBSD_sctp ? IPPROTO_SCTP : IPPROTO_TCP; 412 if (nflag) 413 hints.ai_flags |= AI_NUMERICHOST; 414 } 415 416 if (xflag) { 417 if (uflag) 418 errx(1, "no proxy support for UDP mode"); 419 420 if (FreeBSD_sctp) 421 errx(1, "no proxy support for SCTP mode"); 422 423 if (lflag) 424 errx(1, "no proxy support for listen"); 425 426 if (family == AF_UNIX) 427 errx(1, "no proxy support for unix sockets"); 428 429 /* XXX IPv6 transport to proxy would probably work */ 430 if (family == AF_INET6) 431 errx(1, "no proxy support for IPv6"); 432 433 if (sflag) 434 errx(1, "no proxy support for local source address"); 435 436 proxyhost = strsep(&proxy, ":"); 437 proxyport = proxy; 438 439 memset(&proxyhints, 0, sizeof(struct addrinfo)); 440 proxyhints.ai_family = family; 441 proxyhints.ai_socktype = SOCK_STREAM; 442 proxyhints.ai_protocol = IPPROTO_TCP; 443 if (nflag) 444 proxyhints.ai_flags |= AI_NUMERICHOST; 445 } 446 447 if (lflag) { 448 int connfd; 449 ret = 0; 450 451 if (family == AF_UNIX) { 452 if (uflag) 453 s = unix_bind(host); 454 else 455 s = unix_listen(host); 456 } 457 458 /* Allow only one connection at a time, but stay alive. */ 459 for (;;) { 460 if (family != AF_UNIX) 461 s = local_listen(host, uport, hints); 462 if (s < 0) 463 err(1, NULL); 464 /* 465 * For UDP and -k, don't connect the socket, let it 466 * receive datagrams from multiple socket pairs. 467 */ 468 if (uflag && kflag) 469 readwrite(s); 470 /* 471 * For UDP and not -k, we will use recvfrom() initially 472 * to wait for a caller, then use the regular functions 473 * to talk to the caller. 474 */ 475 else if (uflag && !kflag) { 476 int rv, plen; 477 char buf[16384]; 478 struct sockaddr_storage z; 479 480 len = sizeof(z); 481 plen = 2048; 482 rv = recvfrom(s, buf, plen, MSG_PEEK, 483 (struct sockaddr *)&z, &len); 484 if (rv < 0) 485 err(1, "recvfrom"); 486 487 rv = connect(s, (struct sockaddr *)&z, len); 488 if (rv < 0) 489 err(1, "connect"); 490 491 if (vflag) 492 report_connect((struct sockaddr *)&z, len); 493 494 readwrite(s); 495 } else { 496 len = sizeof(cliaddr); 497 connfd = accept(s, (struct sockaddr *)&cliaddr, 498 &len); 499 if (connfd == -1) { 500 /* For now, all errnos are fatal */ 501 err(1, "accept"); 502 } 503 if (vflag) 504 report_connect((struct sockaddr *)&cliaddr, len); 505 506 if (FreeBSD_Mflag) 507 FreeBSD_stats_setup(connfd); 508 readwrite(connfd); 509 close(connfd); 510 } 511 512 if (family != AF_UNIX) 513 close(s); 514 else if (uflag) { 515 if (connect(s, NULL, 0) < 0) 516 err(1, "connect"); 517 } 518 519 if (!kflag) 520 break; 521 } 522 } else if (family == AF_UNIX) { 523 ret = 0; 524 525 if ((s = unix_connect(host)) > 0 && !zflag) { 526 readwrite(s); 527 close(s); 528 } else 529 ret = 1; 530 531 if (uflag) 532 unlink(unix_dg_tmp_socket); 533 exit(ret); 534 535 } else { 536 int i = 0; 537 538 /* Construct the portlist[] array. */ 539 build_ports(uport); 540 541 /* Cycle through portlist, connecting to each port. */ 542 for (i = 0; portlist[i] != NULL; i++) { 543 if (s) 544 close(s); 545 546 if (xflag) 547 s = socks_connect(host, portlist[i], hints, 548 proxyhost, proxyport, proxyhints, socksv, 549 Pflag); 550 else 551 s = remote_connect(host, portlist[i], hints); 552 553 if (s < 0) 554 continue; 555 556 ret = 0; 557 if (vflag || zflag) { 558 /* For UDP, make sure we are connected. */ 559 if (uflag) { 560 if (udptest(s) == -1) { 561 ret = 1; 562 continue; 563 } 564 } 565 566 /* Don't look up port if -n. */ 567 if (nflag) 568 sv = NULL; 569 else { 570 sv = getservbyport( 571 ntohs(atoi(portlist[i])), 572 uflag ? "udp" : "tcp"); 573 } 574 575 fprintf(stderr, 576 "Connection to %s %s port [%s/%s] " 577 "succeeded!\n", host, portlist[i], 578 uflag ? "udp" : "tcp", 579 sv ? sv->s_name : "*"); 580 } 581 if (Fflag) 582 fdpass(s); 583 else if (!zflag) 584 readwrite(s); 585 } 586 } 587 588 if (s) 589 close(s); 590 if (tun_fd != -1) 591 close(tun_fd); 592 593 exit(ret); 594 } 595 596 /* 597 * unix_bind() 598 * Returns a unix socket bound to the given path 599 */ 600 int 601 unix_bind(char *path) 602 { 603 struct sockaddr_un sun; 604 int s; 605 606 /* Create unix domain socket. */ 607 if ((s = socket(AF_UNIX, uflag ? SOCK_DGRAM : SOCK_STREAM, 608 0)) < 0) 609 return (-1); 610 611 memset(&sun, 0, sizeof(struct sockaddr_un)); 612 sun.sun_family = AF_UNIX; 613 614 if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >= 615 sizeof(sun.sun_path)) { 616 close(s); 617 errno = ENAMETOOLONG; 618 return (-1); 619 } 620 621 if (bind(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) { 622 close(s); 623 return (-1); 624 } 625 return (s); 626 } 627 628 /* 629 * unix_connect() 630 * Returns a socket connected to a local unix socket. Returns -1 on failure. 631 */ 632 int 633 unix_connect(char *path) 634 { 635 struct sockaddr_un sun; 636 int s; 637 638 if (uflag) { 639 if ((s = unix_bind(unix_dg_tmp_socket)) < 0) 640 return (-1); 641 } else { 642 if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) 643 return (-1); 644 } 645 (void)fcntl(s, F_SETFD, FD_CLOEXEC); 646 647 memset(&sun, 0, sizeof(struct sockaddr_un)); 648 sun.sun_family = AF_UNIX; 649 650 if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >= 651 sizeof(sun.sun_path)) { 652 close(s); 653 errno = ENAMETOOLONG; 654 return (-1); 655 } 656 if (connect(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) { 657 close(s); 658 return (-1); 659 } 660 return (s); 661 662 } 663 664 /* 665 * unix_listen() 666 * Create a unix domain socket, and listen on it. 667 */ 668 int 669 unix_listen(char *path) 670 { 671 int s; 672 if ((s = unix_bind(path)) < 0) 673 return (-1); 674 675 if (listen(s, 5) < 0) { 676 close(s); 677 return (-1); 678 } 679 return (s); 680 } 681 682 /* 683 * remote_connect() 684 * Returns a socket connected to a remote host. Properly binds to a local 685 * port or source address if needed. Returns -1 on failure. 686 */ 687 int 688 remote_connect(const char *host, const char *port, struct addrinfo hints) 689 { 690 struct addrinfo *res, *res0; 691 int s, error, on = 1; 692 693 if ((error = getaddrinfo(host, port, &hints, &res))) 694 errx(1, "getaddrinfo: %s", gai_strerror(error)); 695 696 res0 = res; 697 do { 698 if ((s = socket(res0->ai_family, res0->ai_socktype, 699 res0->ai_protocol)) < 0) 700 continue; 701 702 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_SETFIB, 703 &rtableid, sizeof(rtableid)) == -1)) 704 err(1, "setsockopt SO_SETFIB"); 705 706 /* Bind to a local port or source address if specified. */ 707 if (sflag || pflag) { 708 struct addrinfo ahints, *ares; 709 710 /* try IP_BINDANY, but don't insist */ 711 setsockopt(s, IPPROTO_IP, IP_BINDANY, &on, sizeof(on)); 712 memset(&ahints, 0, sizeof(struct addrinfo)); 713 ahints.ai_family = res0->ai_family; 714 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 715 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 716 ahints.ai_flags = AI_PASSIVE; 717 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 718 errx(1, "getaddrinfo: %s", gai_strerror(error)); 719 720 if (bind(s, (struct sockaddr *)ares->ai_addr, 721 ares->ai_addrlen) < 0) 722 err(1, "bind failed"); 723 freeaddrinfo(ares); 724 } 725 726 set_common_sockopts(s, res0->ai_family); 727 728 if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0) 729 break; 730 else if (vflag) 731 warn("connect to %s port %s (%s) failed", host, port, 732 uflag ? "udp" : "tcp"); 733 734 close(s); 735 s = -1; 736 } while ((res0 = res0->ai_next) != NULL); 737 738 freeaddrinfo(res); 739 740 return (s); 741 } 742 743 int 744 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 745 { 746 struct pollfd pfd; 747 socklen_t optlen; 748 int flags, optval; 749 int ret; 750 751 if (timeout != -1) { 752 flags = fcntl(s, F_GETFL, 0); 753 if (fcntl(s, F_SETFL, flags | O_NONBLOCK) == -1) 754 err(1, "set non-blocking mode"); 755 } 756 757 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 758 pfd.fd = s; 759 pfd.events = POLLOUT; 760 if ((ret = poll(&pfd, 1, timeout)) == 1) { 761 optlen = sizeof(optval); 762 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 763 &optval, &optlen)) == 0) { 764 errno = optval; 765 ret = optval == 0 ? 0 : -1; 766 } 767 } else if (ret == 0) { 768 errno = ETIMEDOUT; 769 ret = -1; 770 } else 771 err(1, "poll failed"); 772 } 773 774 if (timeout != -1 && fcntl(s, F_SETFL, flags) == -1) 775 err(1, "restoring flags"); 776 777 return (ret); 778 } 779 780 /* 781 * local_listen() 782 * Returns a socket listening on a local port, binds to specified source 783 * address. Returns -1 on failure. 784 */ 785 int 786 local_listen(char *host, char *port, struct addrinfo hints) 787 { 788 struct addrinfo *res, *res0; 789 int s, ret, x = 1; 790 int error; 791 792 /* Allow nodename to be null. */ 793 hints.ai_flags |= AI_PASSIVE; 794 795 /* 796 * In the case of binding to a wildcard address 797 * default to binding to an ipv4 address. 798 */ 799 if (host == NULL && hints.ai_family == AF_UNSPEC) 800 hints.ai_family = AF_INET; 801 802 if ((error = getaddrinfo(host, port, &hints, &res))) 803 errx(1, "getaddrinfo: %s", gai_strerror(error)); 804 805 res0 = res; 806 do { 807 int opt; 808 809 if ((s = socket(res0->ai_family, res0->ai_socktype, 810 res0->ai_protocol)) < 0) 811 continue; 812 813 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_SETFIB, 814 &rtableid, sizeof(rtableid)) == -1)) 815 err(1, "setsockopt SO_SETFIB"); 816 817 opt = FreeBSD_lb != 0 ? SO_REUSEPORT_LB : SO_REUSEPORT; 818 ret = setsockopt(s, SOL_SOCKET, opt, &x, sizeof(x)); 819 if (ret == -1) 820 err(1, NULL); 821 822 if (FreeBSD_Oflag) { 823 if (setsockopt(s, IPPROTO_TCP, TCP_NOOPT, 824 &FreeBSD_Oflag, sizeof(FreeBSD_Oflag)) == -1) 825 err(1, "disable TCP options"); 826 } 827 828 set_common_sockopts(s, res0->ai_family); 829 830 if (bind(s, (struct sockaddr *)res0->ai_addr, 831 res0->ai_addrlen) == 0) 832 break; 833 834 close(s); 835 s = -1; 836 } while ((res0 = res0->ai_next) != NULL); 837 838 if (!uflag && s != -1) { 839 if (listen(s, 1) < 0) 840 err(1, "listen"); 841 } 842 843 freeaddrinfo(res); 844 845 return (s); 846 } 847 848 /* 849 * readwrite() 850 * Loop that polls on the network file descriptor and stdin. 851 */ 852 void 853 readwrite(int net_fd) 854 { 855 struct pollfd pfd[4]; 856 int stdin_fd = STDIN_FILENO; 857 int stdout_fd = STDOUT_FILENO; 858 unsigned char netinbuf[BUFSIZE]; 859 size_t netinbufpos = 0; 860 unsigned char stdinbuf[BUFSIZE]; 861 size_t stdinbufpos = 0; 862 int n, num_fds; 863 int stats_printed = 0; 864 ssize_t ret; 865 866 /* don't read from stdin if requested */ 867 if (dflag) 868 stdin_fd = -1; 869 870 /* stdin */ 871 pfd[POLL_STDIN].fd = (tun_fd != -1) ? tun_fd : stdin_fd; 872 pfd[POLL_STDIN].events = POLLIN; 873 874 /* network out */ 875 pfd[POLL_NETOUT].fd = net_fd; 876 pfd[POLL_NETOUT].events = 0; 877 878 /* network in */ 879 pfd[POLL_NETIN].fd = net_fd; 880 pfd[POLL_NETIN].events = POLLIN; 881 882 /* stdout */ 883 pfd[POLL_STDOUT].fd = (tun_fd != -1) ? tun_fd : stdout_fd; 884 pfd[POLL_STDOUT].events = 0; 885 886 while (1) { 887 /* both inputs are gone, buffers are empty, we are done */ 888 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 889 && stdinbufpos == 0 && netinbufpos == 0) { 890 if (FreeBSD_Mflag && !stats_printed) 891 FreeBSD_stats_print(net_fd); 892 close(net_fd); 893 return; 894 } 895 /* both outputs are gone, we can't continue */ 896 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 897 if (FreeBSD_Mflag && !stats_printed) 898 FreeBSD_stats_print(net_fd); 899 close(net_fd); 900 return; 901 } 902 /* listen and net in gone, queues empty, done */ 903 if (lflag && pfd[POLL_NETIN].fd == -1 904 && stdinbufpos == 0 && netinbufpos == 0) { 905 if (FreeBSD_Mflag && !stats_printed) 906 FreeBSD_stats_print(net_fd); 907 close(net_fd); 908 return; 909 } 910 911 /* help says -i is for "wait between lines sent". We read and 912 * write arbitrary amounts of data, and we don't want to start 913 * scanning for newlines, so this is as good as it gets */ 914 if (iflag) 915 sleep(iflag); 916 917 /* poll */ 918 num_fds = poll(pfd, 4, timeout); 919 920 /* treat poll errors */ 921 if (num_fds == -1) { 922 close(net_fd); 923 err(1, "polling error"); 924 } 925 926 /* timeout happened */ 927 if (num_fds == 0) { 928 if (FreeBSD_Mflag) 929 FreeBSD_stats_print(net_fd); 930 return; 931 } 932 933 /* treat socket error conditions */ 934 for (n = 0; n < 4; n++) { 935 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 936 pfd[n].fd = -1; 937 } 938 } 939 /* reading is possible after HUP */ 940 if (pfd[POLL_STDIN].events & POLLIN && 941 pfd[POLL_STDIN].revents & POLLHUP && 942 ! (pfd[POLL_STDIN].revents & POLLIN)) 943 pfd[POLL_STDIN].fd = -1; 944 945 if (pfd[POLL_NETIN].events & POLLIN && 946 pfd[POLL_NETIN].revents & POLLHUP && 947 ! (pfd[POLL_NETIN].revents & POLLIN)) 948 pfd[POLL_NETIN].fd = -1; 949 950 if (pfd[POLL_NETOUT].revents & POLLHUP) { 951 if (Nflag) 952 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 953 pfd[POLL_NETOUT].fd = -1; 954 } 955 /* if HUP, stop watching stdout */ 956 if (pfd[POLL_STDOUT].revents & POLLHUP) 957 pfd[POLL_STDOUT].fd = -1; 958 /* if no net out, stop watching stdin */ 959 if (pfd[POLL_NETOUT].fd == -1) 960 pfd[POLL_STDIN].fd = -1; 961 /* if no stdout, stop watching net in */ 962 if (pfd[POLL_STDOUT].fd == -1) { 963 if (pfd[POLL_NETIN].fd != -1) 964 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 965 pfd[POLL_NETIN].fd = -1; 966 } 967 968 /* try to read from stdin */ 969 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 970 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 971 &stdinbufpos); 972 /* error or eof on stdin - remove from pfd */ 973 if (ret == 0 || ret == -1) 974 pfd[POLL_STDIN].fd = -1; 975 /* read something - poll net out */ 976 if (stdinbufpos > 0) 977 pfd[POLL_NETOUT].events = POLLOUT; 978 /* filled buffer - remove self from polling */ 979 if (stdinbufpos == BUFSIZE) 980 pfd[POLL_STDIN].events = 0; 981 } 982 /* try to write to network */ 983 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 984 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 985 &stdinbufpos, FreeBSD_crlf); 986 if (ret == -1) 987 pfd[POLL_NETOUT].fd = -1; 988 /* buffer empty - remove self from polling */ 989 if (stdinbufpos == 0) 990 pfd[POLL_NETOUT].events = 0; 991 /* buffer no longer full - poll stdin again */ 992 if (stdinbufpos < BUFSIZE) 993 pfd[POLL_STDIN].events = POLLIN; 994 } 995 /* try to read from network */ 996 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 997 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 998 &netinbufpos); 999 if (ret == -1) 1000 pfd[POLL_NETIN].fd = -1; 1001 /* eof on net in - remove from pfd */ 1002 if (ret == 0) { 1003 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1004 pfd[POLL_NETIN].fd = -1; 1005 } 1006 /* read something - poll stdout */ 1007 if (netinbufpos > 0) 1008 pfd[POLL_STDOUT].events = POLLOUT; 1009 /* filled buffer - remove self from polling */ 1010 if (netinbufpos == BUFSIZE) 1011 pfd[POLL_NETIN].events = 0; 1012 /* handle telnet */ 1013 if (tflag) 1014 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1015 netinbufpos); 1016 } 1017 /* try to write to stdout */ 1018 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1019 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1020 &netinbufpos, 0); 1021 if (ret == -1) 1022 pfd[POLL_STDOUT].fd = -1; 1023 /* buffer empty - remove self from polling */ 1024 if (netinbufpos == 0) 1025 pfd[POLL_STDOUT].events = 0; 1026 /* buffer no longer full - poll net in again */ 1027 if (netinbufpos < BUFSIZE) 1028 pfd[POLL_NETIN].events = POLLIN; 1029 } 1030 1031 /* stdin gone and queue empty? */ 1032 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1033 if (pfd[POLL_NETOUT].fd != -1 && Nflag) { 1034 if (FreeBSD_Mflag) { 1035 FreeBSD_stats_print(net_fd); 1036 stats_printed = 1; 1037 } 1038 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1039 } 1040 pfd[POLL_NETOUT].fd = -1; 1041 } 1042 /* net in gone and queue empty? */ 1043 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1044 pfd[POLL_STDOUT].fd = -1; 1045 } 1046 } 1047 } 1048 1049 ssize_t 1050 write_wrapper(int fd, const void *buf, size_t buflen) 1051 { 1052 ssize_t n = write(fd, buf, buflen); 1053 /* don't treat EAGAIN, EINTR as error */ 1054 return (n == -1 && (errno == EAGAIN || errno == EINTR)) ? -2 : n; 1055 } 1056 1057 ssize_t 1058 drainbuf(int fd, unsigned char *buf, size_t *bufpos, int crlf) 1059 { 1060 ssize_t n = *bufpos, n2 = 0; 1061 ssize_t adjust; 1062 unsigned char *lf = NULL; 1063 1064 if (crlf) { 1065 lf = memchr(buf, '\n', *bufpos); 1066 if (lf && (lf == buf || *(lf - 1) != '\r')) 1067 n = lf - buf; 1068 else 1069 lf = NULL; 1070 } 1071 1072 if (n != 0) { 1073 n = write_wrapper(fd, buf, n); 1074 if (n <= 0) 1075 return n; 1076 } 1077 1078 if (lf) { 1079 n2 = write_wrapper(fd, "\r\n", 2); 1080 if (n2 <= 0) 1081 return n2; 1082 n += 1; 1083 } 1084 1085 /* adjust buffer */ 1086 adjust = *bufpos - n; 1087 if (adjust > 0) 1088 memmove(buf, buf + n, adjust); 1089 *bufpos -= n; 1090 return n; 1091 } 1092 1093 1094 ssize_t 1095 fillbuf(int fd, unsigned char *buf, size_t *bufpos) 1096 { 1097 size_t num = BUFSIZE - *bufpos; 1098 ssize_t n; 1099 1100 n = read(fd, buf + *bufpos, num); 1101 /* don't treat EAGAIN, EINTR as error */ 1102 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1103 n = -2; 1104 if (n <= 0) 1105 return n; 1106 *bufpos += n; 1107 return n; 1108 } 1109 1110 /* 1111 * fdpass() 1112 * Pass the connected file descriptor to stdout and exit. 1113 */ 1114 void 1115 fdpass(int nfd) 1116 { 1117 struct msghdr mh; 1118 union { 1119 struct cmsghdr hdr; 1120 char buf[CMSG_SPACE(sizeof(int))]; 1121 } cmsgbuf; 1122 struct cmsghdr *cmsg; 1123 struct iovec iov; 1124 char c = '\0'; 1125 ssize_t r; 1126 struct pollfd pfd; 1127 1128 /* Avoid obvious stupidity */ 1129 if (isatty(STDOUT_FILENO)) 1130 errx(1, "Cannot pass file descriptor to tty"); 1131 1132 bzero(&mh, sizeof(mh)); 1133 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1134 bzero(&iov, sizeof(iov)); 1135 1136 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1137 mh.msg_controllen = sizeof(cmsgbuf.buf); 1138 cmsg = CMSG_FIRSTHDR(&mh); 1139 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1140 cmsg->cmsg_level = SOL_SOCKET; 1141 cmsg->cmsg_type = SCM_RIGHTS; 1142 *(int *)CMSG_DATA(cmsg) = nfd; 1143 1144 iov.iov_base = &c; 1145 iov.iov_len = 1; 1146 mh.msg_iov = &iov; 1147 mh.msg_iovlen = 1; 1148 1149 bzero(&pfd, sizeof(pfd)); 1150 pfd.fd = STDOUT_FILENO; 1151 pfd.events = POLLOUT; 1152 for (;;) { 1153 r = sendmsg(STDOUT_FILENO, &mh, 0); 1154 if (r == -1) { 1155 if (errno == EAGAIN || errno == EINTR) { 1156 if (poll(&pfd, 1, -1) == -1) 1157 err(1, "poll"); 1158 continue; 1159 } 1160 err(1, "sendmsg"); 1161 } else if (r != 1) 1162 errx(1, "sendmsg: unexpected return value %zd", r); 1163 else 1164 break; 1165 } 1166 exit(0); 1167 } 1168 1169 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1170 void 1171 atelnet(int nfd, unsigned char *buf, unsigned int size) 1172 { 1173 unsigned char *p, *end; 1174 unsigned char obuf[4]; 1175 1176 if (size < 3) 1177 return; 1178 end = buf + size - 2; 1179 1180 for (p = buf; p < end; p++) { 1181 if (*p != IAC) 1182 continue; 1183 1184 obuf[0] = IAC; 1185 p++; 1186 if ((*p == WILL) || (*p == WONT)) 1187 obuf[1] = DONT; 1188 else if ((*p == DO) || (*p == DONT)) 1189 obuf[1] = WONT; 1190 else 1191 continue; 1192 1193 p++; 1194 obuf[2] = *p; 1195 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1196 warn("Write Error!"); 1197 } 1198 } 1199 1200 /* 1201 * build_ports() 1202 * Build an array of ports in portlist[], listing each port 1203 * that we should try to connect to. 1204 */ 1205 void 1206 build_ports(char *p) 1207 { 1208 const char *errstr; 1209 char *n; 1210 int hi, lo, cp; 1211 int x = 0; 1212 1213 if ((n = strchr(p, '-')) != NULL) { 1214 *n = '\0'; 1215 n++; 1216 1217 /* Make sure the ports are in order: lowest->highest. */ 1218 hi = strtonum(n, 1, PORT_MAX, &errstr); 1219 if (errstr) 1220 errx(1, "port number %s: %s", errstr, n); 1221 lo = strtonum(p, 1, PORT_MAX, &errstr); 1222 if (errstr) 1223 errx(1, "port number %s: %s", errstr, p); 1224 1225 if (lo > hi) { 1226 cp = hi; 1227 hi = lo; 1228 lo = cp; 1229 } 1230 1231 /* Load ports sequentially. */ 1232 for (cp = lo; cp <= hi; cp++) { 1233 portlist[x] = calloc(1, PORT_MAX_LEN); 1234 if (portlist[x] == NULL) 1235 err(1, NULL); 1236 snprintf(portlist[x], PORT_MAX_LEN, "%d", cp); 1237 x++; 1238 } 1239 1240 /* Randomly swap ports. */ 1241 if (rflag) { 1242 int y; 1243 char *c; 1244 1245 for (x = 0; x <= (hi - lo); x++) { 1246 y = (arc4random() & 0xFFFF) % (hi - lo); 1247 c = portlist[x]; 1248 portlist[x] = portlist[y]; 1249 portlist[y] = c; 1250 } 1251 } 1252 } else { 1253 hi = strtonum(p, 1, PORT_MAX, &errstr); 1254 if (errstr) 1255 errx(1, "port number %s: %s", errstr, p); 1256 portlist[0] = strdup(p); 1257 if (portlist[0] == NULL) 1258 err(1, NULL); 1259 } 1260 } 1261 1262 /* 1263 * udptest() 1264 * Do a few writes to see if the UDP port is there. 1265 * Fails once PF state table is full. 1266 */ 1267 int 1268 udptest(int s) 1269 { 1270 int i, ret; 1271 1272 for (i = 0; i <= 3; i++) { 1273 if (write(s, "X", 1) == 1) 1274 ret = 1; 1275 else 1276 ret = -1; 1277 } 1278 return (ret); 1279 } 1280 1281 void 1282 FreeBSD_stats_setup(int s) 1283 { 1284 1285 if (setsockopt(s, IPPROTO_TCP, TCP_STATS, 1286 &FreeBSD_Mflag, sizeof(FreeBSD_Mflag)) == -1) { 1287 if (errno == EOPNOTSUPP) { 1288 warnx("getsockopt(TCP_STATS) failed; " 1289 "kernel built without \"options STATS\"?"); 1290 } 1291 err(1, "enable TCP_STATS gathering"); 1292 } 1293 } 1294 1295 void 1296 FreeBSD_stats_print(int s) 1297 { 1298 #ifdef WITH_STATS 1299 struct statsblob *statsb; 1300 struct sbuf *sb; 1301 socklen_t sockoptlen; 1302 int error; 1303 1304 /* 1305 * This usleep is a workaround for TCP_STATS reporting 1306 * incorrect values for TXPB. 1307 */ 1308 usleep(100000); 1309 1310 sockoptlen = 2048; 1311 statsb = malloc(sockoptlen); 1312 if (statsb == NULL) 1313 err(1, "malloc"); 1314 error = getsockopt(s, IPPROTO_TCP, TCP_STATS, statsb, &sockoptlen); 1315 if (error != 0) { 1316 if (errno == EOVERFLOW && statsb->cursz > sockoptlen) { 1317 /* Retry with a larger size. */ 1318 sockoptlen = statsb->cursz; 1319 statsb = realloc(statsb, sockoptlen); 1320 if (statsb == NULL) 1321 err(1, "realloc"); 1322 error = getsockopt(s, IPPROTO_TCP, TCP_STATS, 1323 statsb, &sockoptlen); 1324 } 1325 if (error != 0) 1326 err(1, "getsockopt"); 1327 } 1328 1329 sb = sbuf_new_auto(); 1330 error = stats_blob_tostr(statsb, sb, SB_STRFMT_JSON, SB_TOSTR_META); 1331 if (error != 0) 1332 errc(1, error, "stats_blob_tostr"); 1333 1334 error = sbuf_finish(sb); 1335 if (error != 0) 1336 err(1, "sbuf_finish"); 1337 1338 fprintf(stderr, "%s\n", sbuf_data(sb)); 1339 #endif 1340 } 1341 1342 void 1343 set_common_sockopts(int s, int af) 1344 { 1345 int x = 1; 1346 1347 if (Sflag) { 1348 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1349 &x, sizeof(x)) == -1) 1350 err(1, NULL); 1351 } 1352 if (Dflag) { 1353 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1354 &x, sizeof(x)) == -1) 1355 err(1, NULL); 1356 } 1357 if (Tflag != -1) { 1358 int proto, option; 1359 1360 if (af == AF_INET6) { 1361 proto = IPPROTO_IPV6; 1362 option = IPV6_TCLASS; 1363 } else { 1364 proto = IPPROTO_IP; 1365 option = IP_TOS; 1366 } 1367 1368 if (setsockopt(s, proto, option, &Tflag, sizeof(Tflag)) == -1) 1369 err(1, "set IP ToS"); 1370 } 1371 if (Iflag) { 1372 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1373 &Iflag, sizeof(Iflag)) == -1) 1374 err(1, "set TCP receive buffer size"); 1375 } 1376 if (Oflag) { 1377 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1378 &Oflag, sizeof(Oflag)) == -1) 1379 err(1, "set TCP send buffer size"); 1380 } 1381 if (FreeBSD_Oflag) { 1382 if (setsockopt(s, IPPROTO_TCP, TCP_NOOPT, 1383 &FreeBSD_Oflag, sizeof(FreeBSD_Oflag)) == -1) 1384 err(1, "disable TCP options"); 1385 } 1386 if (FreeBSD_Mflag) 1387 FreeBSD_stats_setup(s); 1388 #ifdef IPSEC 1389 if (ipsec_policy[0] != NULL) 1390 add_ipsec_policy(s, af, ipsec_policy[0]); 1391 if (ipsec_policy[1] != NULL) 1392 add_ipsec_policy(s, af, ipsec_policy[1]); 1393 #endif 1394 } 1395 1396 int 1397 map_tos(char *s, int *val) 1398 { 1399 /* DiffServ Codepoints and other TOS mappings */ 1400 const struct toskeywords { 1401 const char *keyword; 1402 int val; 1403 } *t, toskeywords[] = { 1404 { "af11", IPTOS_DSCP_AF11 }, 1405 { "af12", IPTOS_DSCP_AF12 }, 1406 { "af13", IPTOS_DSCP_AF13 }, 1407 { "af21", IPTOS_DSCP_AF21 }, 1408 { "af22", IPTOS_DSCP_AF22 }, 1409 { "af23", IPTOS_DSCP_AF23 }, 1410 { "af31", IPTOS_DSCP_AF31 }, 1411 { "af32", IPTOS_DSCP_AF32 }, 1412 { "af33", IPTOS_DSCP_AF33 }, 1413 { "af41", IPTOS_DSCP_AF41 }, 1414 { "af42", IPTOS_DSCP_AF42 }, 1415 { "af43", IPTOS_DSCP_AF43 }, 1416 { "critical", IPTOS_PREC_CRITIC_ECP }, 1417 { "cs0", IPTOS_DSCP_CS0 }, 1418 { "cs1", IPTOS_DSCP_CS1 }, 1419 { "cs2", IPTOS_DSCP_CS2 }, 1420 { "cs3", IPTOS_DSCP_CS3 }, 1421 { "cs4", IPTOS_DSCP_CS4 }, 1422 { "cs5", IPTOS_DSCP_CS5 }, 1423 { "cs6", IPTOS_DSCP_CS6 }, 1424 { "cs7", IPTOS_DSCP_CS7 }, 1425 { "ef", IPTOS_DSCP_EF }, 1426 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1427 { "lowdelay", IPTOS_LOWDELAY }, 1428 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1429 { "reliability", IPTOS_RELIABILITY }, 1430 { "throughput", IPTOS_THROUGHPUT }, 1431 { NULL, -1 }, 1432 }; 1433 1434 for (t = toskeywords; t->keyword != NULL; t++) { 1435 if (strcmp(s, t->keyword) == 0) { 1436 *val = t->val; 1437 return (1); 1438 } 1439 } 1440 1441 return (0); 1442 } 1443 1444 void 1445 report_connect(const struct sockaddr *sa, socklen_t salen) 1446 { 1447 char remote_host[NI_MAXHOST]; 1448 char remote_port[NI_MAXSERV]; 1449 int herr; 1450 int flags = NI_NUMERICSERV; 1451 1452 if (nflag) 1453 flags |= NI_NUMERICHOST; 1454 1455 if ((herr = getnameinfo(sa, salen, 1456 remote_host, sizeof(remote_host), 1457 remote_port, sizeof(remote_port), 1458 flags)) != 0) { 1459 if (herr == EAI_SYSTEM) 1460 err(1, "getnameinfo"); 1461 else 1462 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1463 } 1464 1465 fprintf(stderr, 1466 "Connection from %s %s " 1467 "received!\n", remote_host, remote_port); 1468 } 1469 1470 void 1471 help(void) 1472 { 1473 usage(0); 1474 fprintf(stderr, "\tCommand Summary:\n\ 1475 \t-4 Use IPv4\n\ 1476 \t-6 Use IPv6\n\ 1477 \t--crlf Convert LF into CRLF when sending data over the network\n\ 1478 \t-D Enable the debug socket option\n\ 1479 \t-d Detach from stdin\n"); 1480 #ifdef IPSEC 1481 fprintf(stderr, "\ 1482 \t-E Use IPsec ESP\n\ 1483 \t-e policy Use specified IPsec policy\n"); 1484 #endif 1485 fprintf(stderr, "\ 1486 \t-F Pass socket fd\n\ 1487 \t-h This help text\n\ 1488 \t-I length TCP receive buffer length\n\ 1489 \t-i secs\t Delay interval for lines sent, ports scanned\n\ 1490 \t-k Keep inbound sockets open for multiple connects\n\ 1491 \t-l Listen mode, for inbound connects\n\ 1492 \t-N Shutdown the network socket after EOF on stdin\n\ 1493 \t-n Suppress name/port resolutions\n\ 1494 \t--no-tcpopt Disable TCP options\n\ 1495 \t--sctp\t SCTP mode\n\ 1496 \t--tun tundev Use tun device rather than stdio\n\ 1497 \t-O length TCP send buffer length\n\ 1498 \t-P proxyuser\tUsername for proxy authentication\n\ 1499 \t-p port\t Specify local port for remote connects\n\ 1500 \t-r Randomize remote ports\n\ 1501 \t-S Enable the TCP MD5 signature option\n\ 1502 \t-s addr\t Local source address\n\ 1503 \t-T toskeyword\tSet IP Type of Service\n\ 1504 \t-t Answer TELNET negotiation\n\ 1505 \t-U Use UNIX domain socket\n\ 1506 \t-u UDP mode\n\ 1507 \t-V rtable Specify alternate routing table\n\ 1508 \t-v Verbose\n\ 1509 \t-w secs\t Timeout for connects and final net reads\n\ 1510 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1511 \t-x addr[:port]\tSpecify proxy address and port\n\ 1512 \t-z Zero-I/O mode [used for scanning]\n\ 1513 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1514 #ifdef IPSEC 1515 fprintf(stderr, "\tSee ipsec_set_policy(3) for -e argument format\n"); 1516 #endif 1517 exit(1); 1518 } 1519 1520 #ifdef IPSEC 1521 void 1522 add_ipsec_policy(int s, int af, char *policy) 1523 { 1524 char *raw; 1525 int e; 1526 1527 raw = ipsec_set_policy(policy, strlen(policy)); 1528 if (raw == NULL) 1529 errx(1, "ipsec_set_policy `%s': %s", policy, 1530 ipsec_strerror()); 1531 if (af == AF_INET) 1532 e = setsockopt(s, IPPROTO_IP, IP_IPSEC_POLICY, raw, 1533 ipsec_get_policylen(raw)); 1534 if (af == AF_INET6) 1535 e = setsockopt(s, IPPROTO_IPV6, IPV6_IPSEC_POLICY, raw, 1536 ipsec_get_policylen(raw)); 1537 if (e < 0) 1538 err(1, "ipsec policy cannot be configured"); 1539 free(raw); 1540 if (vflag) 1541 fprintf(stderr, "ipsec policy configured: `%s'\n", policy); 1542 return; 1543 } 1544 #endif /* IPSEC */ 1545 1546 void 1547 usage(int ret) 1548 { 1549 fprintf(stderr, 1550 #ifdef IPSEC 1551 "usage: nc [-46DdEFhklNnrStUuvz] [-e policy] [-I length] [-i interval] [-O length]\n" 1552 #else 1553 "usage: nc [-46DdFhklNnrStUuvz] [-I length] [-i interval] [-O length]\n" 1554 #endif 1555 "\t [--no-tcpopt] [--sctp]\n" 1556 "\t [-P proxy_username] [-p source_port] [-s source] [-T ToS]\n" 1557 "\t [--tun tundev] [-V rtable] [-w timeout] [-X proxy_protocol]\n" 1558 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1559 if (ret) 1560 exit(1); 1561 } 1562