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 int strtoport(char *portstr, int udp); 123 void build_ports(char *); 124 void help(void); 125 int local_listen(char *, char *, struct addrinfo); 126 void readwrite(int); 127 void fdpass(int nfd) __attribute__((noreturn)); 128 int remote_connect(const char *, const char *, struct addrinfo); 129 int timeout_connect(int, const struct sockaddr *, socklen_t); 130 int socks_connect(const char *, const char *, struct addrinfo, 131 const char *, const char *, struct addrinfo, int, const char *); 132 int udptest(int); 133 int unix_bind(char *); 134 int unix_connect(char *); 135 int unix_listen(char *); 136 void FreeBSD_stats_setup(int); 137 void FreeBSD_stats_print(int); 138 void set_common_sockopts(int, int); 139 int map_tos(char *, int *); 140 void report_connect(const struct sockaddr *, socklen_t); 141 void usage(int); 142 ssize_t write_wrapper(int, const void *, size_t); 143 ssize_t drainbuf(int, unsigned char *, size_t *, int); 144 ssize_t fillbuf(int, unsigned char *, size_t *); 145 146 #ifdef IPSEC 147 void add_ipsec_policy(int, int, char *); 148 149 char *ipsec_policy[2]; 150 #endif 151 152 enum { 153 FREEBSD_TUN = CHAR_MAX, /* avoid collision with return values from getopt */ 154 }; 155 156 int 157 main(int argc, char *argv[]) 158 { 159 int ch, s, ret, socksv, ipsec_count; 160 int numfibs; 161 size_t intsize = sizeof(int); 162 char *host, *uport; 163 struct addrinfo hints; 164 struct servent *sv; 165 socklen_t len; 166 struct sockaddr_storage cliaddr; 167 char *proxy; 168 const char *errstr, *proxyhost = "", *proxyport = NULL, *tundev = NULL; 169 struct addrinfo proxyhints; 170 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 171 struct option longopts[] = { 172 { "crlf", no_argument, &FreeBSD_crlf, 1 }, 173 { "lb", no_argument, &FreeBSD_lb, 1 }, 174 { "no-tcpopt", no_argument, &FreeBSD_Oflag, 1 }, 175 { "sctp", no_argument, &FreeBSD_sctp, 1 }, 176 { "tun", required_argument, NULL, FREEBSD_TUN }, 177 { NULL, 0, NULL, 0 } 178 }; 179 180 ret = 1; 181 ipsec_count = 0; 182 s = 0; 183 socksv = 5; 184 host = NULL; 185 uport = NULL; 186 sv = NULL; 187 188 signal(SIGPIPE, SIG_IGN); 189 190 while ((ch = getopt_long(argc, argv, 191 "46DdEe:FhI:i:klMNnoO:P:p:rSs:tT:UuV:vw:X:x:z", 192 longopts, NULL)) != -1) { 193 switch (ch) { 194 case '4': 195 family = AF_INET; 196 break; 197 case '6': 198 family = AF_INET6; 199 break; 200 case 'U': 201 family = AF_UNIX; 202 break; 203 case 'X': 204 if (strcasecmp(optarg, "connect") == 0) 205 socksv = -1; /* HTTP proxy CONNECT */ 206 else if (strcmp(optarg, "4") == 0) 207 socksv = 4; /* SOCKS v.4 */ 208 else if (strcmp(optarg, "5") == 0) 209 socksv = 5; /* SOCKS v.5 */ 210 else 211 errx(1, "unsupported proxy protocol"); 212 break; 213 case 'd': 214 dflag = 1; 215 break; 216 case 'e': 217 #ifdef IPSEC 218 ipsec_policy[ipsec_count++ % 2] = optarg; 219 #else 220 errx(1, "IPsec support unavailable."); 221 #endif 222 break; 223 case 'E': 224 #ifdef IPSEC 225 ipsec_policy[0] = "in ipsec esp/transport//require"; 226 ipsec_policy[1] = "out ipsec esp/transport//require"; 227 #else 228 errx(1, "IPsec support unavailable."); 229 #endif 230 break; 231 case 'F': 232 Fflag = 1; 233 break; 234 case 'h': 235 help(); 236 break; 237 case 'i': 238 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 239 if (errstr) 240 errx(1, "interval %s: %s", errstr, optarg); 241 break; 242 case 'k': 243 kflag = 1; 244 break; 245 case 'l': 246 lflag = 1; 247 break; 248 case 'M': 249 #ifndef WITH_STATS 250 errx(1, "-M requires stats(3) support"); 251 #else 252 FreeBSD_Mflag = 1; 253 #endif 254 break; 255 case 'N': 256 Nflag = 1; 257 break; 258 case 'n': 259 nflag = 1; 260 break; 261 case 'o': 262 fprintf(stderr, "option -o is deprecated.\n"); 263 break; 264 case 'P': 265 Pflag = optarg; 266 break; 267 case 'p': 268 pflag = optarg; 269 break; 270 case 'r': 271 rflag = 1; 272 break; 273 case 's': 274 sflag = optarg; 275 break; 276 case 't': 277 tflag = 1; 278 break; 279 case 'u': 280 uflag = 1; 281 break; 282 case 'V': 283 if (sysctlbyname("net.fibs", &numfibs, &intsize, NULL, 0) == -1) 284 errx(1, "Multiple FIBS not supported"); 285 rtableid = (int)strtonum(optarg, 0, 286 numfibs - 1, &errstr); 287 if (errstr) 288 errx(1, "rtable %s: %s", errstr, optarg); 289 break; 290 case 'v': 291 vflag = 1; 292 break; 293 case 'w': 294 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 295 if (errstr) 296 errx(1, "timeout %s: %s", errstr, optarg); 297 timeout *= 1000; 298 break; 299 case 'x': 300 xflag = 1; 301 if ((proxy = strdup(optarg)) == NULL) 302 err(1, NULL); 303 break; 304 case 'z': 305 zflag = 1; 306 break; 307 case 'D': 308 Dflag = 1; 309 break; 310 case 'I': 311 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 312 if (errstr != NULL) 313 errx(1, "TCP receive window %s: %s", 314 errstr, optarg); 315 break; 316 case 'O': 317 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 318 if (errstr != NULL) { 319 if (strcmp(errstr, "invalid") != 0) 320 errx(1, "TCP send window %s: %s", 321 errstr, optarg); 322 } 323 break; 324 case 'S': 325 Sflag = 1; 326 break; 327 case 'T': 328 errstr = NULL; 329 errno = 0; 330 if (map_tos(optarg, &Tflag)) 331 break; 332 if (strlen(optarg) > 1 && optarg[0] == '0' && 333 optarg[1] == 'x') 334 Tflag = (int)strtol(optarg, NULL, 16); 335 else 336 Tflag = (int)strtonum(optarg, 0, 255, 337 &errstr); 338 if (Tflag < 0 || Tflag > 255 || errstr || errno) 339 errx(1, "illegal tos value %s", optarg); 340 break; 341 case FREEBSD_TUN: 342 tundev = optarg; 343 break; 344 case 0: 345 /* Long option. */ 346 break; 347 default: 348 usage(1); 349 } 350 } 351 argc -= optind; 352 argv += optind; 353 354 /* Cruft to make sure options are clean, and used properly. */ 355 if (argv[0] && !argv[1] && family == AF_UNIX) { 356 host = argv[0]; 357 uport = NULL; 358 } else if (argv[0] && !argv[1]) { 359 if (!lflag) 360 usage(1); 361 uport = argv[0]; 362 host = NULL; 363 } else if (argv[0] && argv[1]) { 364 host = argv[0]; 365 uport = argv[1]; 366 } else 367 usage(1); 368 369 if (lflag && sflag) 370 errx(1, "cannot use -s and -l"); 371 if (lflag && pflag) 372 errx(1, "cannot use -p and -l"); 373 if (lflag && zflag) 374 errx(1, "cannot use -z and -l"); 375 if (!lflag && kflag) 376 errx(1, "must use -l with -k"); 377 if (!lflag && FreeBSD_lb) 378 errx(1, "must use -l with --lb"); 379 if (FreeBSD_sctp) { 380 if (uflag) 381 errx(1, "cannot use -u and --sctp"); 382 if (family == AF_UNIX) 383 errx(1, "cannot use -U and --sctp"); 384 } 385 if (tundev != NULL) { 386 if (!uflag) 387 errx(1, "must use --tun with -u"); 388 tun_fd = open(tundev, O_RDWR); 389 if (tun_fd == -1) 390 errx(1, "unable to open tun device %s", tundev); 391 } 392 393 /* Get name of temporary socket for unix datagram client */ 394 if ((family == AF_UNIX) && uflag && !lflag) { 395 if (sflag) { 396 unix_dg_tmp_socket = sflag; 397 } else { 398 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 399 UNIX_DG_TMP_SOCKET_SIZE); 400 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 401 err(1, "mktemp"); 402 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 403 } 404 } 405 406 /* Initialize addrinfo structure. */ 407 if (family != AF_UNIX) { 408 memset(&hints, 0, sizeof(struct addrinfo)); 409 hints.ai_family = family; 410 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 411 hints.ai_protocol = uflag ? IPPROTO_UDP : 412 FreeBSD_sctp ? IPPROTO_SCTP : IPPROTO_TCP; 413 if (nflag) 414 hints.ai_flags |= AI_NUMERICHOST; 415 } 416 417 if (xflag) { 418 if (uflag) 419 errx(1, "no proxy support for UDP mode"); 420 421 if (FreeBSD_sctp) 422 errx(1, "no proxy support for SCTP mode"); 423 424 if (lflag) 425 errx(1, "no proxy support for listen"); 426 427 if (family == AF_UNIX) 428 errx(1, "no proxy support for unix sockets"); 429 430 /* XXX IPv6 transport to proxy would probably work */ 431 if (family == AF_INET6) 432 errx(1, "no proxy support for IPv6"); 433 434 if (sflag) 435 errx(1, "no proxy support for local source address"); 436 437 proxyhost = strsep(&proxy, ":"); 438 proxyport = proxy; 439 440 memset(&proxyhints, 0, sizeof(struct addrinfo)); 441 proxyhints.ai_family = family; 442 proxyhints.ai_socktype = SOCK_STREAM; 443 proxyhints.ai_protocol = IPPROTO_TCP; 444 if (nflag) 445 proxyhints.ai_flags |= AI_NUMERICHOST; 446 } 447 448 if (lflag) { 449 int connfd; 450 ret = 0; 451 452 if (family == AF_UNIX) { 453 if (uflag) 454 s = unix_bind(host); 455 else 456 s = unix_listen(host); 457 } 458 459 /* Allow only one connection at a time, but stay alive. */ 460 for (;;) { 461 if (family != AF_UNIX) 462 s = local_listen(host, uport, hints); 463 if (s < 0) 464 err(1, NULL); 465 /* 466 * For UDP and -k, don't connect the socket, let it 467 * receive datagrams from multiple socket pairs. 468 */ 469 if (uflag && kflag) 470 readwrite(s); 471 /* 472 * For UDP and not -k, we will use recvfrom() initially 473 * to wait for a caller, then use the regular functions 474 * to talk to the caller. 475 */ 476 else if (uflag && !kflag) { 477 int rv, plen; 478 char buf[16384]; 479 struct sockaddr_storage z; 480 481 len = sizeof(z); 482 plen = 2048; 483 rv = recvfrom(s, buf, plen, MSG_PEEK, 484 (struct sockaddr *)&z, &len); 485 if (rv < 0) 486 err(1, "recvfrom"); 487 488 rv = connect(s, (struct sockaddr *)&z, len); 489 if (rv < 0) 490 err(1, "connect"); 491 492 if (vflag) 493 report_connect((struct sockaddr *)&z, len); 494 495 readwrite(s); 496 } else { 497 len = sizeof(cliaddr); 498 connfd = accept(s, (struct sockaddr *)&cliaddr, 499 &len); 500 if (connfd == -1) { 501 /* For now, all errnos are fatal */ 502 err(1, "accept"); 503 } 504 if (vflag) 505 report_connect((struct sockaddr *)&cliaddr, len); 506 507 if (FreeBSD_Mflag) 508 FreeBSD_stats_setup(connfd); 509 readwrite(connfd); 510 close(connfd); 511 } 512 513 if (family != AF_UNIX) 514 close(s); 515 else if (uflag) { 516 if (connect(s, NULL, 0) < 0) 517 err(1, "connect"); 518 } 519 520 if (!kflag) 521 break; 522 } 523 } else if (family == AF_UNIX) { 524 ret = 0; 525 526 if ((s = unix_connect(host)) > 0 && !zflag) { 527 readwrite(s); 528 close(s); 529 } else 530 ret = 1; 531 532 if (uflag) 533 unlink(unix_dg_tmp_socket); 534 exit(ret); 535 536 } else { 537 int i = 0; 538 539 /* Construct the portlist[] array. */ 540 build_ports(uport); 541 542 /* Cycle through portlist, connecting to each port. */ 543 for (i = 0; portlist[i] != NULL; i++) { 544 if (s) 545 close(s); 546 547 if (xflag) 548 s = socks_connect(host, portlist[i], hints, 549 proxyhost, proxyport, proxyhints, socksv, 550 Pflag); 551 else 552 s = remote_connect(host, portlist[i], hints); 553 554 if (s < 0) 555 continue; 556 557 ret = 0; 558 if (vflag || zflag) { 559 /* For UDP, make sure we are connected. */ 560 if (uflag) { 561 if (udptest(s) == -1) { 562 ret = 1; 563 continue; 564 } 565 } 566 567 /* Don't look up port if -n. */ 568 if (nflag) 569 sv = NULL; 570 else { 571 sv = getservbyport( 572 ntohs(atoi(portlist[i])), 573 uflag ? "udp" : "tcp"); 574 } 575 576 fprintf(stderr, 577 "Connection to %s %s port [%s/%s] " 578 "succeeded!\n", host, portlist[i], 579 uflag ? "udp" : "tcp", 580 sv ? sv->s_name : "*"); 581 } 582 if (Fflag) 583 fdpass(s); 584 else if (!zflag) 585 readwrite(s); 586 } 587 } 588 589 if (s) 590 close(s); 591 if (tun_fd != -1) 592 close(tun_fd); 593 594 exit(ret); 595 } 596 597 /* 598 * unix_bind() 599 * Returns a unix socket bound to the given path 600 */ 601 int 602 unix_bind(char *path) 603 { 604 struct sockaddr_un sun; 605 int s; 606 607 /* Create unix domain socket. */ 608 if ((s = socket(AF_UNIX, uflag ? SOCK_DGRAM : SOCK_STREAM, 609 0)) < 0) 610 return (-1); 611 612 memset(&sun, 0, sizeof(struct sockaddr_un)); 613 sun.sun_family = AF_UNIX; 614 615 if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >= 616 sizeof(sun.sun_path)) { 617 close(s); 618 errno = ENAMETOOLONG; 619 return (-1); 620 } 621 622 if (bind(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) { 623 close(s); 624 return (-1); 625 } 626 return (s); 627 } 628 629 /* 630 * unix_connect() 631 * Returns a socket connected to a local unix socket. Returns -1 on failure. 632 */ 633 int 634 unix_connect(char *path) 635 { 636 struct sockaddr_un sun; 637 int s; 638 639 if (uflag) { 640 if ((s = unix_bind(unix_dg_tmp_socket)) < 0) 641 return (-1); 642 } else { 643 if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0) 644 return (-1); 645 } 646 (void)fcntl(s, F_SETFD, FD_CLOEXEC); 647 648 memset(&sun, 0, sizeof(struct sockaddr_un)); 649 sun.sun_family = AF_UNIX; 650 651 if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >= 652 sizeof(sun.sun_path)) { 653 close(s); 654 errno = ENAMETOOLONG; 655 return (-1); 656 } 657 if (connect(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) { 658 close(s); 659 return (-1); 660 } 661 return (s); 662 663 } 664 665 /* 666 * unix_listen() 667 * Create a unix domain socket, and listen on it. 668 */ 669 int 670 unix_listen(char *path) 671 { 672 int s; 673 if ((s = unix_bind(path)) < 0) 674 return (-1); 675 676 if (listen(s, 5) < 0) { 677 close(s); 678 return (-1); 679 } 680 return (s); 681 } 682 683 /* 684 * remote_connect() 685 * Returns a socket connected to a remote host. Properly binds to a local 686 * port or source address if needed. Returns -1 on failure. 687 */ 688 int 689 remote_connect(const char *host, const char *port, struct addrinfo hints) 690 { 691 struct addrinfo *res, *res0; 692 int s, error, on = 1; 693 694 if ((error = getaddrinfo(host, port, &hints, &res))) 695 errx(1, "getaddrinfo: %s", gai_strerror(error)); 696 697 res0 = res; 698 do { 699 if ((s = socket(res0->ai_family, res0->ai_socktype, 700 res0->ai_protocol)) < 0) 701 continue; 702 703 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_SETFIB, 704 &rtableid, sizeof(rtableid)) == -1)) 705 err(1, "setsockopt SO_SETFIB"); 706 707 /* Bind to a local port or source address if specified. */ 708 if (sflag || pflag) { 709 struct addrinfo ahints, *ares; 710 711 /* try IP_BINDANY, but don't insist */ 712 setsockopt(s, IPPROTO_IP, IP_BINDANY, &on, sizeof(on)); 713 memset(&ahints, 0, sizeof(struct addrinfo)); 714 ahints.ai_family = res0->ai_family; 715 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 716 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 717 ahints.ai_flags = AI_PASSIVE; 718 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 719 errx(1, "getaddrinfo: %s", gai_strerror(error)); 720 721 if (bind(s, (struct sockaddr *)ares->ai_addr, 722 ares->ai_addrlen) < 0) 723 err(1, "bind failed"); 724 freeaddrinfo(ares); 725 } 726 727 set_common_sockopts(s, res0->ai_family); 728 729 if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0) 730 break; 731 else if (vflag) 732 warn("connect to %s port %s (%s) failed", host, port, 733 uflag ? "udp" : "tcp"); 734 735 close(s); 736 s = -1; 737 } while ((res0 = res0->ai_next) != NULL); 738 739 freeaddrinfo(res); 740 741 return (s); 742 } 743 744 int 745 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 746 { 747 struct pollfd pfd; 748 socklen_t optlen; 749 int flags, optval; 750 int ret; 751 752 if (timeout != -1) { 753 flags = fcntl(s, F_GETFL, 0); 754 if (fcntl(s, F_SETFL, flags | O_NONBLOCK) == -1) 755 err(1, "set non-blocking mode"); 756 } 757 758 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 759 pfd.fd = s; 760 pfd.events = POLLOUT; 761 if ((ret = poll(&pfd, 1, timeout)) == 1) { 762 optlen = sizeof(optval); 763 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 764 &optval, &optlen)) == 0) { 765 errno = optval; 766 ret = optval == 0 ? 0 : -1; 767 } 768 } else if (ret == 0) { 769 errno = ETIMEDOUT; 770 ret = -1; 771 } else 772 err(1, "poll failed"); 773 } 774 775 if (timeout != -1 && fcntl(s, F_SETFL, flags) == -1) 776 err(1, "restoring flags"); 777 778 return (ret); 779 } 780 781 /* 782 * local_listen() 783 * Returns a socket listening on a local port, binds to specified source 784 * address. Returns -1 on failure. 785 */ 786 int 787 local_listen(char *host, char *port, struct addrinfo hints) 788 { 789 struct addrinfo *res, *res0; 790 int s, ret, x = 1; 791 int error; 792 793 /* Allow nodename to be null. */ 794 hints.ai_flags |= AI_PASSIVE; 795 796 /* 797 * In the case of binding to a wildcard address 798 * default to binding to an ipv4 address. 799 */ 800 if (host == NULL && hints.ai_family == AF_UNSPEC) 801 hints.ai_family = AF_INET; 802 803 if ((error = getaddrinfo(host, port, &hints, &res))) 804 errx(1, "getaddrinfo: %s", gai_strerror(error)); 805 806 res0 = res; 807 do { 808 int opt; 809 810 if ((s = socket(res0->ai_family, res0->ai_socktype, 811 res0->ai_protocol)) < 0) 812 continue; 813 814 if (rtableid >= 0 && (setsockopt(s, SOL_SOCKET, SO_SETFIB, 815 &rtableid, sizeof(rtableid)) == -1)) 816 err(1, "setsockopt SO_SETFIB"); 817 818 opt = FreeBSD_lb != 0 ? SO_REUSEPORT_LB : SO_REUSEPORT; 819 ret = setsockopt(s, SOL_SOCKET, opt, &x, sizeof(x)); 820 if (ret == -1) 821 err(1, NULL); 822 823 if (FreeBSD_Oflag) { 824 if (setsockopt(s, IPPROTO_TCP, TCP_NOOPT, 825 &FreeBSD_Oflag, sizeof(FreeBSD_Oflag)) == -1) 826 err(1, "disable TCP options"); 827 } 828 829 set_common_sockopts(s, res0->ai_family); 830 831 if (bind(s, (struct sockaddr *)res0->ai_addr, 832 res0->ai_addrlen) == 0) 833 break; 834 835 close(s); 836 s = -1; 837 } while ((res0 = res0->ai_next) != NULL); 838 839 if (!uflag && s != -1) { 840 if (listen(s, 1) < 0) 841 err(1, "listen"); 842 } 843 844 freeaddrinfo(res); 845 846 return (s); 847 } 848 849 /* 850 * readwrite() 851 * Loop that polls on the network file descriptor and stdin. 852 */ 853 void 854 readwrite(int net_fd) 855 { 856 struct pollfd pfd[4]; 857 int stdin_fd = STDIN_FILENO; 858 int stdout_fd = STDOUT_FILENO; 859 unsigned char netinbuf[BUFSIZE]; 860 size_t netinbufpos = 0; 861 unsigned char stdinbuf[BUFSIZE]; 862 size_t stdinbufpos = 0; 863 int n, num_fds; 864 int stats_printed = 0; 865 ssize_t ret; 866 867 /* don't read from stdin if requested */ 868 if (dflag) 869 stdin_fd = -1; 870 871 /* stdin */ 872 pfd[POLL_STDIN].fd = (tun_fd != -1) ? tun_fd : stdin_fd; 873 pfd[POLL_STDIN].events = POLLIN; 874 875 /* network out */ 876 pfd[POLL_NETOUT].fd = net_fd; 877 pfd[POLL_NETOUT].events = 0; 878 879 /* network in */ 880 pfd[POLL_NETIN].fd = net_fd; 881 pfd[POLL_NETIN].events = POLLIN; 882 883 /* stdout */ 884 pfd[POLL_STDOUT].fd = (tun_fd != -1) ? tun_fd : stdout_fd; 885 pfd[POLL_STDOUT].events = 0; 886 887 while (1) { 888 /* both inputs are gone, buffers are empty, we are done */ 889 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 890 && stdinbufpos == 0 && netinbufpos == 0) { 891 if (FreeBSD_Mflag && !stats_printed) 892 FreeBSD_stats_print(net_fd); 893 close(net_fd); 894 return; 895 } 896 /* both outputs are gone, we can't continue */ 897 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 898 if (FreeBSD_Mflag && !stats_printed) 899 FreeBSD_stats_print(net_fd); 900 close(net_fd); 901 return; 902 } 903 /* listen and net in gone, queues empty, done */ 904 if (lflag && pfd[POLL_NETIN].fd == -1 905 && stdinbufpos == 0 && netinbufpos == 0) { 906 if (FreeBSD_Mflag && !stats_printed) 907 FreeBSD_stats_print(net_fd); 908 close(net_fd); 909 return; 910 } 911 912 /* help says -i is for "wait between lines sent". We read and 913 * write arbitrary amounts of data, and we don't want to start 914 * scanning for newlines, so this is as good as it gets */ 915 if (iflag) 916 sleep(iflag); 917 918 /* poll */ 919 num_fds = poll(pfd, 4, timeout); 920 921 /* treat poll errors */ 922 if (num_fds == -1) { 923 close(net_fd); 924 err(1, "polling error"); 925 } 926 927 /* timeout happened */ 928 if (num_fds == 0) { 929 if (FreeBSD_Mflag) 930 FreeBSD_stats_print(net_fd); 931 return; 932 } 933 934 /* treat socket error conditions */ 935 for (n = 0; n < 4; n++) { 936 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 937 pfd[n].fd = -1; 938 } 939 } 940 /* reading is possible after HUP */ 941 if (pfd[POLL_STDIN].events & POLLIN && 942 pfd[POLL_STDIN].revents & POLLHUP && 943 ! (pfd[POLL_STDIN].revents & POLLIN)) 944 pfd[POLL_STDIN].fd = -1; 945 946 if (pfd[POLL_NETIN].events & POLLIN && 947 pfd[POLL_NETIN].revents & POLLHUP && 948 ! (pfd[POLL_NETIN].revents & POLLIN)) 949 pfd[POLL_NETIN].fd = -1; 950 951 if (pfd[POLL_NETOUT].revents & POLLHUP) { 952 if (Nflag) 953 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 954 pfd[POLL_NETOUT].fd = -1; 955 } 956 /* if HUP, stop watching stdout */ 957 if (pfd[POLL_STDOUT].revents & POLLHUP) 958 pfd[POLL_STDOUT].fd = -1; 959 /* if no net out, stop watching stdin */ 960 if (pfd[POLL_NETOUT].fd == -1) 961 pfd[POLL_STDIN].fd = -1; 962 /* if no stdout, stop watching net in */ 963 if (pfd[POLL_STDOUT].fd == -1) { 964 if (pfd[POLL_NETIN].fd != -1) 965 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 966 pfd[POLL_NETIN].fd = -1; 967 } 968 969 /* try to read from stdin */ 970 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 971 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 972 &stdinbufpos); 973 /* error or eof on stdin - remove from pfd */ 974 if (ret == 0 || ret == -1) 975 pfd[POLL_STDIN].fd = -1; 976 /* read something - poll net out */ 977 if (stdinbufpos > 0) 978 pfd[POLL_NETOUT].events = POLLOUT; 979 /* filled buffer - remove self from polling */ 980 if (stdinbufpos == BUFSIZE) 981 pfd[POLL_STDIN].events = 0; 982 } 983 /* try to write to network */ 984 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 985 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 986 &stdinbufpos, FreeBSD_crlf); 987 if (ret == -1) 988 pfd[POLL_NETOUT].fd = -1; 989 /* buffer empty - remove self from polling */ 990 if (stdinbufpos == 0) 991 pfd[POLL_NETOUT].events = 0; 992 /* buffer no longer full - poll stdin again */ 993 if (stdinbufpos < BUFSIZE) 994 pfd[POLL_STDIN].events = POLLIN; 995 } 996 /* try to read from network */ 997 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 998 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 999 &netinbufpos); 1000 if (ret == -1) 1001 pfd[POLL_NETIN].fd = -1; 1002 /* eof on net in - remove from pfd */ 1003 if (ret == 0) { 1004 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1005 pfd[POLL_NETIN].fd = -1; 1006 } 1007 /* read something - poll stdout */ 1008 if (netinbufpos > 0) 1009 pfd[POLL_STDOUT].events = POLLOUT; 1010 /* filled buffer - remove self from polling */ 1011 if (netinbufpos == BUFSIZE) 1012 pfd[POLL_NETIN].events = 0; 1013 /* handle telnet */ 1014 if (tflag) 1015 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1016 netinbufpos); 1017 } 1018 /* try to write to stdout */ 1019 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1020 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1021 &netinbufpos, 0); 1022 if (ret == -1) 1023 pfd[POLL_STDOUT].fd = -1; 1024 /* buffer empty - remove self from polling */ 1025 if (netinbufpos == 0) 1026 pfd[POLL_STDOUT].events = 0; 1027 /* buffer no longer full - poll net in again */ 1028 if (netinbufpos < BUFSIZE) 1029 pfd[POLL_NETIN].events = POLLIN; 1030 } 1031 1032 /* stdin gone and queue empty? */ 1033 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1034 if (pfd[POLL_NETOUT].fd != -1 && Nflag) { 1035 if (FreeBSD_Mflag) { 1036 FreeBSD_stats_print(net_fd); 1037 stats_printed = 1; 1038 } 1039 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1040 } 1041 pfd[POLL_NETOUT].fd = -1; 1042 } 1043 /* net in gone and queue empty? */ 1044 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1045 pfd[POLL_STDOUT].fd = -1; 1046 } 1047 } 1048 } 1049 1050 ssize_t 1051 write_wrapper(int fd, const void *buf, size_t buflen) 1052 { 1053 ssize_t n = write(fd, buf, buflen); 1054 /* don't treat EAGAIN, EINTR as error */ 1055 return (n == -1 && (errno == EAGAIN || errno == EINTR)) ? -2 : n; 1056 } 1057 1058 ssize_t 1059 drainbuf(int fd, unsigned char *buf, size_t *bufpos, int crlf) 1060 { 1061 ssize_t n = *bufpos, n2 = 0; 1062 ssize_t adjust; 1063 unsigned char *lf = NULL; 1064 1065 if (crlf) { 1066 lf = memchr(buf, '\n', *bufpos); 1067 if (lf && (lf == buf || *(lf - 1) != '\r')) 1068 n = lf - buf; 1069 else 1070 lf = NULL; 1071 } 1072 1073 if (n != 0) { 1074 n = write_wrapper(fd, buf, n); 1075 if (n <= 0) 1076 return n; 1077 } 1078 1079 if (lf) { 1080 n2 = write_wrapper(fd, "\r\n", 2); 1081 if (n2 <= 0) 1082 return n2; 1083 n += 1; 1084 } 1085 1086 /* adjust buffer */ 1087 adjust = *bufpos - n; 1088 if (adjust > 0) 1089 memmove(buf, buf + n, adjust); 1090 *bufpos -= n; 1091 return n; 1092 } 1093 1094 1095 ssize_t 1096 fillbuf(int fd, unsigned char *buf, size_t *bufpos) 1097 { 1098 size_t num = BUFSIZE - *bufpos; 1099 ssize_t n; 1100 1101 n = read(fd, buf + *bufpos, num); 1102 /* don't treat EAGAIN, EINTR as error */ 1103 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1104 n = -2; 1105 if (n <= 0) 1106 return n; 1107 *bufpos += n; 1108 return n; 1109 } 1110 1111 /* 1112 * fdpass() 1113 * Pass the connected file descriptor to stdout and exit. 1114 */ 1115 void 1116 fdpass(int nfd) 1117 { 1118 struct msghdr mh; 1119 union { 1120 struct cmsghdr hdr; 1121 char buf[CMSG_SPACE(sizeof(int))]; 1122 } cmsgbuf; 1123 struct cmsghdr *cmsg; 1124 struct iovec iov; 1125 char c = '\0'; 1126 ssize_t r; 1127 struct pollfd pfd; 1128 1129 /* Avoid obvious stupidity */ 1130 if (isatty(STDOUT_FILENO)) 1131 errx(1, "Cannot pass file descriptor to tty"); 1132 1133 bzero(&mh, sizeof(mh)); 1134 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1135 bzero(&iov, sizeof(iov)); 1136 1137 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1138 mh.msg_controllen = sizeof(cmsgbuf.buf); 1139 cmsg = CMSG_FIRSTHDR(&mh); 1140 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1141 cmsg->cmsg_level = SOL_SOCKET; 1142 cmsg->cmsg_type = SCM_RIGHTS; 1143 *(int *)CMSG_DATA(cmsg) = nfd; 1144 1145 iov.iov_base = &c; 1146 iov.iov_len = 1; 1147 mh.msg_iov = &iov; 1148 mh.msg_iovlen = 1; 1149 1150 bzero(&pfd, sizeof(pfd)); 1151 pfd.fd = STDOUT_FILENO; 1152 pfd.events = POLLOUT; 1153 for (;;) { 1154 r = sendmsg(STDOUT_FILENO, &mh, 0); 1155 if (r == -1) { 1156 if (errno == EAGAIN || errno == EINTR) { 1157 if (poll(&pfd, 1, -1) == -1) 1158 err(1, "poll"); 1159 continue; 1160 } 1161 err(1, "sendmsg"); 1162 } else if (r != 1) 1163 errx(1, "sendmsg: unexpected return value %zd", r); 1164 else 1165 break; 1166 } 1167 exit(0); 1168 } 1169 1170 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1171 void 1172 atelnet(int nfd, unsigned char *buf, unsigned int size) 1173 { 1174 unsigned char *p, *end; 1175 unsigned char obuf[4]; 1176 1177 if (size < 3) 1178 return; 1179 end = buf + size - 2; 1180 1181 for (p = buf; p < end; p++) { 1182 if (*p != IAC) 1183 continue; 1184 1185 obuf[0] = IAC; 1186 p++; 1187 if ((*p == WILL) || (*p == WONT)) 1188 obuf[1] = DONT; 1189 else if ((*p == DO) || (*p == DONT)) 1190 obuf[1] = WONT; 1191 else 1192 continue; 1193 1194 p++; 1195 obuf[2] = *p; 1196 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1197 warn("Write Error!"); 1198 } 1199 } 1200 1201 int 1202 strtoport(char *portstr, int udp) 1203 { 1204 struct servent *entry; 1205 const char *errstr; 1206 char *proto; 1207 int port = -1; 1208 1209 proto = udp ? "udp" : "tcp"; 1210 1211 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1212 if (errstr == NULL) 1213 return port; 1214 if (errno != EINVAL) 1215 errx(1, "port number %s: %s", errstr, portstr); 1216 if ((entry = getservbyname(portstr, proto)) == NULL) 1217 errx(1, "service \"%s\" unknown", portstr); 1218 return ntohs(entry->s_port); 1219 } 1220 1221 /* 1222 * build_ports() 1223 * Build an array of ports in portlist[], listing each port 1224 * that we should try to connect to. 1225 */ 1226 void 1227 build_ports(char *p) 1228 { 1229 char *n; 1230 int hi, lo, cp; 1231 int x = 0; 1232 1233 if ((n = strchr(p, '-')) != NULL) { 1234 *n = '\0'; 1235 n++; 1236 1237 /* Make sure the ports are in order: lowest->highest. */ 1238 hi = strtoport(n, uflag); 1239 lo = strtoport(p, uflag); 1240 if (lo > hi) { 1241 cp = hi; 1242 hi = lo; 1243 lo = cp; 1244 } 1245 1246 /* Load ports sequentially. */ 1247 for (cp = lo; cp <= hi; cp++) { 1248 portlist[x] = calloc(1, PORT_MAX_LEN); 1249 if (portlist[x] == NULL) 1250 err(1, NULL); 1251 snprintf(portlist[x], PORT_MAX_LEN, "%d", cp); 1252 x++; 1253 } 1254 1255 /* Randomly swap ports. */ 1256 if (rflag) { 1257 int y; 1258 char *c; 1259 1260 for (x = 0; x <= (hi - lo); x++) { 1261 y = (arc4random() & 0xFFFF) % (hi - lo); 1262 c = portlist[x]; 1263 portlist[x] = portlist[y]; 1264 portlist[y] = c; 1265 } 1266 } 1267 } else { 1268 char *tmp; 1269 1270 hi = strtoport(p, uflag); 1271 if (asprintf(&tmp, "%d", hi) != -1) 1272 portlist[0] = tmp; 1273 else 1274 err(1, NULL); 1275 } 1276 } 1277 1278 /* 1279 * udptest() 1280 * Do a few writes to see if the UDP port is there. 1281 * Fails once PF state table is full. 1282 */ 1283 int 1284 udptest(int s) 1285 { 1286 int i, ret; 1287 1288 for (i = 0; i <= 3; i++) { 1289 if (write(s, "X", 1) == 1) 1290 ret = 1; 1291 else 1292 ret = -1; 1293 } 1294 return (ret); 1295 } 1296 1297 void 1298 FreeBSD_stats_setup(int s) 1299 { 1300 1301 if (setsockopt(s, IPPROTO_TCP, TCP_STATS, 1302 &FreeBSD_Mflag, sizeof(FreeBSD_Mflag)) == -1) { 1303 if (errno == EOPNOTSUPP) { 1304 warnx("getsockopt(TCP_STATS) failed; " 1305 "kernel built without \"options STATS\"?"); 1306 } 1307 err(1, "enable TCP_STATS gathering"); 1308 } 1309 } 1310 1311 void 1312 FreeBSD_stats_print(int s) 1313 { 1314 #ifdef WITH_STATS 1315 struct statsblob *statsb; 1316 struct sbuf *sb; 1317 socklen_t sockoptlen; 1318 int error; 1319 1320 /* 1321 * This usleep is a workaround for TCP_STATS reporting 1322 * incorrect values for TXPB. 1323 */ 1324 usleep(100000); 1325 1326 sockoptlen = 2048; 1327 statsb = malloc(sockoptlen); 1328 if (statsb == NULL) 1329 err(1, "malloc"); 1330 error = getsockopt(s, IPPROTO_TCP, TCP_STATS, statsb, &sockoptlen); 1331 if (error != 0) { 1332 if (errno == EOVERFLOW && statsb->cursz > sockoptlen) { 1333 /* Retry with a larger size. */ 1334 sockoptlen = statsb->cursz; 1335 statsb = realloc(statsb, sockoptlen); 1336 if (statsb == NULL) 1337 err(1, "realloc"); 1338 error = getsockopt(s, IPPROTO_TCP, TCP_STATS, 1339 statsb, &sockoptlen); 1340 } 1341 if (error != 0) 1342 err(1, "getsockopt"); 1343 } 1344 1345 sb = sbuf_new_auto(); 1346 error = stats_blob_tostr(statsb, sb, SB_STRFMT_JSON, SB_TOSTR_META); 1347 if (error != 0) 1348 errc(1, error, "stats_blob_tostr"); 1349 1350 error = sbuf_finish(sb); 1351 if (error != 0) 1352 err(1, "sbuf_finish"); 1353 1354 fprintf(stderr, "%s\n", sbuf_data(sb)); 1355 #endif 1356 } 1357 1358 void 1359 set_common_sockopts(int s, int af) 1360 { 1361 int x = 1; 1362 1363 if (Sflag) { 1364 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1365 &x, sizeof(x)) == -1) 1366 err(1, NULL); 1367 } 1368 if (Dflag) { 1369 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1370 &x, sizeof(x)) == -1) 1371 err(1, NULL); 1372 } 1373 if (Tflag != -1) { 1374 int proto, option; 1375 1376 if (af == AF_INET6) { 1377 proto = IPPROTO_IPV6; 1378 option = IPV6_TCLASS; 1379 } else { 1380 proto = IPPROTO_IP; 1381 option = IP_TOS; 1382 } 1383 1384 if (setsockopt(s, proto, option, &Tflag, sizeof(Tflag)) == -1) 1385 err(1, "set IP ToS"); 1386 } 1387 if (Iflag) { 1388 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1389 &Iflag, sizeof(Iflag)) == -1) 1390 err(1, "set TCP receive buffer size"); 1391 } 1392 if (Oflag) { 1393 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1394 &Oflag, sizeof(Oflag)) == -1) 1395 err(1, "set TCP send buffer size"); 1396 } 1397 if (FreeBSD_Oflag) { 1398 if (setsockopt(s, IPPROTO_TCP, TCP_NOOPT, 1399 &FreeBSD_Oflag, sizeof(FreeBSD_Oflag)) == -1) 1400 err(1, "disable TCP options"); 1401 } 1402 if (FreeBSD_Mflag) 1403 FreeBSD_stats_setup(s); 1404 #ifdef IPSEC 1405 if (ipsec_policy[0] != NULL) 1406 add_ipsec_policy(s, af, ipsec_policy[0]); 1407 if (ipsec_policy[1] != NULL) 1408 add_ipsec_policy(s, af, ipsec_policy[1]); 1409 #endif 1410 } 1411 1412 int 1413 map_tos(char *s, int *val) 1414 { 1415 /* DiffServ Codepoints and other TOS mappings */ 1416 const struct toskeywords { 1417 const char *keyword; 1418 int val; 1419 } *t, toskeywords[] = { 1420 { "af11", IPTOS_DSCP_AF11 }, 1421 { "af12", IPTOS_DSCP_AF12 }, 1422 { "af13", IPTOS_DSCP_AF13 }, 1423 { "af21", IPTOS_DSCP_AF21 }, 1424 { "af22", IPTOS_DSCP_AF22 }, 1425 { "af23", IPTOS_DSCP_AF23 }, 1426 { "af31", IPTOS_DSCP_AF31 }, 1427 { "af32", IPTOS_DSCP_AF32 }, 1428 { "af33", IPTOS_DSCP_AF33 }, 1429 { "af41", IPTOS_DSCP_AF41 }, 1430 { "af42", IPTOS_DSCP_AF42 }, 1431 { "af43", IPTOS_DSCP_AF43 }, 1432 { "critical", IPTOS_PREC_CRITIC_ECP }, 1433 { "cs0", IPTOS_DSCP_CS0 }, 1434 { "cs1", IPTOS_DSCP_CS1 }, 1435 { "cs2", IPTOS_DSCP_CS2 }, 1436 { "cs3", IPTOS_DSCP_CS3 }, 1437 { "cs4", IPTOS_DSCP_CS4 }, 1438 { "cs5", IPTOS_DSCP_CS5 }, 1439 { "cs6", IPTOS_DSCP_CS6 }, 1440 { "cs7", IPTOS_DSCP_CS7 }, 1441 { "ef", IPTOS_DSCP_EF }, 1442 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1443 { "lowdelay", IPTOS_LOWDELAY }, 1444 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1445 { "reliability", IPTOS_RELIABILITY }, 1446 { "throughput", IPTOS_THROUGHPUT }, 1447 { NULL, -1 }, 1448 }; 1449 1450 for (t = toskeywords; t->keyword != NULL; t++) { 1451 if (strcmp(s, t->keyword) == 0) { 1452 *val = t->val; 1453 return (1); 1454 } 1455 } 1456 1457 return (0); 1458 } 1459 1460 void 1461 report_connect(const struct sockaddr *sa, socklen_t salen) 1462 { 1463 char remote_host[NI_MAXHOST]; 1464 char remote_port[NI_MAXSERV]; 1465 int herr; 1466 int flags = NI_NUMERICSERV; 1467 1468 if (nflag) 1469 flags |= NI_NUMERICHOST; 1470 1471 if ((herr = getnameinfo(sa, salen, 1472 remote_host, sizeof(remote_host), 1473 remote_port, sizeof(remote_port), 1474 flags)) != 0) { 1475 if (herr == EAI_SYSTEM) 1476 err(1, "getnameinfo"); 1477 else 1478 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1479 } 1480 1481 fprintf(stderr, 1482 "Connection from %s %s " 1483 "received!\n", remote_host, remote_port); 1484 } 1485 1486 void 1487 help(void) 1488 { 1489 usage(0); 1490 fprintf(stderr, "\tCommand Summary:\n\ 1491 \t-4 Use IPv4\n\ 1492 \t-6 Use IPv6\n\ 1493 \t--crlf Convert LF into CRLF when sending data over the network\n\ 1494 \t-D Enable the debug socket option\n\ 1495 \t-d Detach from stdin\n"); 1496 #ifdef IPSEC 1497 fprintf(stderr, "\ 1498 \t-E Use IPsec ESP\n\ 1499 \t-e policy Use specified IPsec policy\n"); 1500 #endif 1501 fprintf(stderr, "\ 1502 \t-F Pass socket fd\n\ 1503 \t-h This help text\n\ 1504 \t-I length TCP receive buffer length\n\ 1505 \t-i secs\t Delay interval for lines sent, ports scanned\n\ 1506 \t-k Keep inbound sockets open for multiple connects\n\ 1507 \t-l Listen mode, for inbound connects\n\ 1508 \t-N Shutdown the network socket after EOF on stdin\n\ 1509 \t-n Suppress name/port resolutions\n\ 1510 \t--no-tcpopt Disable TCP options\n\ 1511 \t--sctp\t SCTP mode\n\ 1512 \t--tun tundev Use tun device rather than stdio\n\ 1513 \t-O length TCP send buffer length\n\ 1514 \t-P proxyuser\tUsername for proxy authentication\n\ 1515 \t-p port\t Specify local port for remote connects\n\ 1516 \t-r Randomize remote ports\n\ 1517 \t-S Enable the TCP MD5 signature option\n\ 1518 \t-s addr\t Local source address\n\ 1519 \t-T toskeyword\tSet IP Type of Service\n\ 1520 \t-t Answer TELNET negotiation\n\ 1521 \t-U Use UNIX domain socket\n\ 1522 \t-u UDP mode\n\ 1523 \t-V rtable Specify alternate routing table\n\ 1524 \t-v Verbose\n\ 1525 \t-w secs\t Timeout for connects and final net reads\n\ 1526 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1527 \t-x addr[:port]\tSpecify proxy address and port\n\ 1528 \t-z Zero-I/O mode [used for scanning]\n\ 1529 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1530 #ifdef IPSEC 1531 fprintf(stderr, "\tSee ipsec_set_policy(3) for -e argument format\n"); 1532 #endif 1533 exit(1); 1534 } 1535 1536 #ifdef IPSEC 1537 void 1538 add_ipsec_policy(int s, int af, char *policy) 1539 { 1540 char *raw; 1541 int e; 1542 1543 raw = ipsec_set_policy(policy, strlen(policy)); 1544 if (raw == NULL) 1545 errx(1, "ipsec_set_policy `%s': %s", policy, 1546 ipsec_strerror()); 1547 if (af == AF_INET) 1548 e = setsockopt(s, IPPROTO_IP, IP_IPSEC_POLICY, raw, 1549 ipsec_get_policylen(raw)); 1550 if (af == AF_INET6) 1551 e = setsockopt(s, IPPROTO_IPV6, IPV6_IPSEC_POLICY, raw, 1552 ipsec_get_policylen(raw)); 1553 if (e < 0) 1554 err(1, "ipsec policy cannot be configured"); 1555 free(raw); 1556 if (vflag) 1557 fprintf(stderr, "ipsec policy configured: `%s'\n", policy); 1558 return; 1559 } 1560 #endif /* IPSEC */ 1561 1562 void 1563 usage(int ret) 1564 { 1565 fprintf(stderr, 1566 #ifdef IPSEC 1567 "usage: nc [-46DdEFhklNnrStUuvz] [-e policy] [-I length] [-i interval] [-O length]\n" 1568 #else 1569 "usage: nc [-46DdFhklNnrStUuvz] [-I length] [-i interval] [-O length]\n" 1570 #endif 1571 "\t [--no-tcpopt] [--sctp]\n" 1572 "\t [-P proxy_username] [-p source_port] [-s source] [-T ToS]\n" 1573 "\t [--tun tundev] [-V rtable] [-w timeout] [-X proxy_protocol]\n" 1574 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1575 if (ret) 1576 exit(1); 1577 } 1578