1 /* $OpenBSD: netcat.c,v 1.163 2016/09/03 17:35:34 bcook Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org> 4 * Copyright (c) 2015 Bob Beck. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * Re-written nc(1) for OpenBSD. Original implementation by 32 * *Hobbit* <hobbit@avian.org>. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 40 #include <netinet/in.h> 41 #include <netinet/tcp.h> 42 #include <netinet/ip.h> 43 #include <arpa/telnet.h> 44 45 #include <err.h> 46 #include <errno.h> 47 #include <limits.h> 48 #include <netdb.h> 49 #include <poll.h> 50 #include <signal.h> 51 #include <stdarg.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <time.h> 56 #include <unistd.h> 57 #include <tls.h> 58 #include "atomicio.h" 59 60 #define PORT_MAX 65535 61 #define UNIX_DG_TMP_SOCKET_SIZE 19 62 63 #define POLL_STDIN 0 64 #define POLL_NETOUT 1 65 #define POLL_NETIN 2 66 #define POLL_STDOUT 3 67 #define BUFSIZE 16384 68 #define DEFAULT_CA_FILE "/etc/ssl/cert.pem" 69 70 #define TLS_LEGACY (1 << 1) 71 #define TLS_NOVERIFY (1 << 2) 72 #define TLS_NONAME (1 << 3) 73 #define TLS_CCERT (1 << 4) 74 75 /* Command Line Options */ 76 int dflag; /* detached, no stdin */ 77 int Fflag; /* fdpass sock to stdout */ 78 unsigned int iflag; /* Interval Flag */ 79 int kflag; /* More than one connect */ 80 int lflag; /* Bind to local port */ 81 int Nflag; /* shutdown() network socket */ 82 int nflag; /* Don't do name look up */ 83 char *Pflag; /* Proxy username */ 84 char *pflag; /* Localport flag */ 85 int rflag; /* Random ports flag */ 86 char *sflag; /* Source Address */ 87 int tflag; /* Telnet Emulation */ 88 int uflag; /* UDP - Default to TCP */ 89 int vflag; /* Verbosity */ 90 int xflag; /* Socks proxy */ 91 int zflag; /* Port Scan Flag */ 92 int Dflag; /* sodebug */ 93 int Iflag; /* TCP receive buffer size */ 94 int Oflag; /* TCP send buffer size */ 95 int Sflag; /* TCP MD5 signature option */ 96 int Tflag = -1; /* IP Type of Service */ 97 int rtableid = -1; 98 99 int usetls; /* use TLS */ 100 char *Cflag; /* Public cert file */ 101 char *Kflag; /* Private key file */ 102 char *Rflag = DEFAULT_CA_FILE; /* Root CA file */ 103 int tls_cachanged; /* Using non-default CA file */ 104 int TLSopt; /* TLS options */ 105 char *tls_expectname; /* required name in peer cert */ 106 char *tls_expecthash; /* required hash of peer cert */ 107 108 int timeout = -1; 109 int family = AF_UNSPEC; 110 char *portlist[PORT_MAX+1]; 111 char *unix_dg_tmp_socket; 112 int ttl = -1; 113 int minttl = -1; 114 115 void atelnet(int, unsigned char *, unsigned int); 116 void build_ports(char *); 117 void help(void); 118 int local_listen(char *, char *, struct addrinfo); 119 void readwrite(int, struct tls *); 120 void fdpass(int nfd) __attribute__((noreturn)); 121 int remote_connect(const char *, const char *, struct addrinfo); 122 int timeout_connect(int, const struct sockaddr *, socklen_t); 123 int socks_connect(const char *, const char *, struct addrinfo, 124 const char *, const char *, struct addrinfo, int, const char *); 125 int udptest(int); 126 int unix_bind(char *, int); 127 int unix_connect(char *); 128 int unix_listen(char *); 129 void set_common_sockopts(int, int); 130 int map_tos(char *, int *); 131 int map_tls(char *, int *); 132 void report_connect(const struct sockaddr *, socklen_t, char *); 133 void report_tls(struct tls *tls_ctx, char * host, char *tls_expectname); 134 void usage(int); 135 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 136 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 137 void tls_setup_client(struct tls *, int, char *); 138 struct tls *tls_setup_server(struct tls *, int, char *); 139 140 int 141 main(int argc, char *argv[]) 142 { 143 int ch, s = -1, ret, socksv; 144 char *host, *uport; 145 struct addrinfo hints; 146 struct servent *sv; 147 socklen_t len; 148 struct sockaddr_storage cliaddr; 149 char *proxy; 150 const char *errstr, *proxyhost = "", *proxyport = NULL; 151 struct addrinfo proxyhints; 152 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 153 struct tls_config *tls_cfg = NULL; 154 struct tls *tls_ctx = NULL; 155 156 ret = 1; 157 socksv = 5; 158 host = NULL; 159 uport = NULL; 160 sv = NULL; 161 162 signal(SIGPIPE, SIG_IGN); 163 164 while ((ch = getopt(argc, argv, 165 "46C:cDde:FH:hI:i:K:klM:m:NnO:P:p:R:rSs:T:tUuV:vw:X:x:z")) != -1) { 166 switch (ch) { 167 case '4': 168 family = AF_INET; 169 break; 170 case '6': 171 family = AF_INET6; 172 break; 173 case 'U': 174 family = AF_UNIX; 175 break; 176 case 'X': 177 if (strcasecmp(optarg, "connect") == 0) 178 socksv = -1; /* HTTP proxy CONNECT */ 179 else if (strcmp(optarg, "4") == 0) 180 socksv = 4; /* SOCKS v.4 */ 181 else if (strcmp(optarg, "5") == 0) 182 socksv = 5; /* SOCKS v.5 */ 183 else 184 errx(1, "unsupported proxy protocol"); 185 break; 186 case 'C': 187 Cflag = optarg; 188 break; 189 case 'c': 190 usetls = 1; 191 break; 192 case 'd': 193 dflag = 1; 194 break; 195 case 'e': 196 tls_expectname = optarg; 197 break; 198 case 'F': 199 Fflag = 1; 200 break; 201 case 'H': 202 tls_expecthash = optarg; 203 break; 204 case 'h': 205 help(); 206 break; 207 case 'i': 208 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 209 if (errstr) 210 errx(1, "interval %s: %s", errstr, optarg); 211 break; 212 case 'K': 213 Kflag = optarg; 214 break; 215 case 'k': 216 kflag = 1; 217 break; 218 case 'l': 219 lflag = 1; 220 break; 221 case 'M': 222 ttl = strtonum(optarg, 0, 255, &errstr); 223 if (errstr) 224 errx(1, "ttl is %s", errstr); 225 break; 226 case 'm': 227 minttl = strtonum(optarg, 0, 255, &errstr); 228 if (errstr) 229 errx(1, "minttl is %s", errstr); 230 break; 231 case 'N': 232 Nflag = 1; 233 break; 234 case 'n': 235 nflag = 1; 236 break; 237 case 'P': 238 Pflag = optarg; 239 break; 240 case 'p': 241 pflag = optarg; 242 break; 243 case 'R': 244 tls_cachanged = 1; 245 Rflag = optarg; 246 break; 247 case 'r': 248 rflag = 1; 249 break; 250 case 's': 251 sflag = optarg; 252 break; 253 case 't': 254 tflag = 1; 255 break; 256 case 'u': 257 uflag = 1; 258 break; 259 case 'V': 260 rtableid = (int)strtonum(optarg, 0, 261 RT_TABLEID_MAX, &errstr); 262 if (errstr) 263 errx(1, "rtable %s: %s", errstr, optarg); 264 break; 265 case 'v': 266 vflag = 1; 267 break; 268 case 'w': 269 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 270 if (errstr) 271 errx(1, "timeout %s: %s", errstr, optarg); 272 timeout *= 1000; 273 break; 274 case 'x': 275 xflag = 1; 276 if ((proxy = strdup(optarg)) == NULL) 277 err(1, NULL); 278 break; 279 case 'z': 280 zflag = 1; 281 break; 282 case 'D': 283 Dflag = 1; 284 break; 285 case 'I': 286 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 287 if (errstr != NULL) 288 errx(1, "TCP receive window %s: %s", 289 errstr, optarg); 290 break; 291 case 'O': 292 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 293 if (errstr != NULL) 294 errx(1, "TCP send window %s: %s", 295 errstr, optarg); 296 break; 297 case 'S': 298 Sflag = 1; 299 break; 300 case 'T': 301 errstr = NULL; 302 errno = 0; 303 if (map_tos(optarg, &Tflag)) 304 break; 305 if (map_tls(optarg, &TLSopt)) 306 break; 307 if (strlen(optarg) > 1 && optarg[0] == '0' && 308 optarg[1] == 'x') 309 Tflag = (int)strtol(optarg, NULL, 16); 310 else 311 Tflag = (int)strtonum(optarg, 0, 255, 312 &errstr); 313 if (Tflag < 0 || Tflag > 255 || errstr || errno) 314 errx(1, "illegal tos/tls value %s", optarg); 315 break; 316 default: 317 usage(1); 318 } 319 } 320 argc -= optind; 321 argv += optind; 322 323 if (rtableid >= 0) 324 if (setrtable(rtableid) == -1) 325 err(1, "setrtable"); 326 327 if (family == AF_UNIX) { 328 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 329 err(1, "pledge"); 330 } else if (Fflag) { 331 if (Pflag) { 332 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 333 err(1, "pledge"); 334 } else if (pledge("stdio inet dns sendfd", NULL) == -1) 335 err(1, "pledge"); 336 } else if (Pflag) { 337 if (pledge("stdio inet dns tty", NULL) == -1) 338 err(1, "pledge"); 339 } else if (usetls) { 340 if (pledge("stdio rpath inet dns", NULL) == -1) 341 err(1, "pledge"); 342 } else if (pledge("stdio inet dns", NULL) == -1) 343 err(1, "pledge"); 344 345 /* Cruft to make sure options are clean, and used properly. */ 346 if (argv[0] && !argv[1] && family == AF_UNIX) { 347 host = argv[0]; 348 uport = NULL; 349 } else if (argv[0] && !argv[1]) { 350 if (!lflag) 351 usage(1); 352 uport = argv[0]; 353 host = NULL; 354 } else if (argv[0] && argv[1]) { 355 host = argv[0]; 356 uport = argv[1]; 357 } else 358 usage(1); 359 360 if (lflag && sflag) 361 errx(1, "cannot use -s and -l"); 362 if (lflag && pflag) 363 errx(1, "cannot use -p and -l"); 364 if (lflag && zflag) 365 errx(1, "cannot use -z and -l"); 366 if (!lflag && kflag) 367 errx(1, "must use -l with -k"); 368 if (uflag && usetls) 369 errx(1, "cannot use -c and -u"); 370 if ((family == AF_UNIX) && usetls) 371 errx(1, "cannot use -c and -U"); 372 if ((family == AF_UNIX) && Fflag) 373 errx(1, "cannot use -F and -U"); 374 if (Fflag && usetls) 375 errx(1, "cannot use -c and -F"); 376 if (TLSopt && !usetls) 377 errx(1, "you must specify -c to use TLS options"); 378 if (Cflag && !usetls) 379 errx(1, "you must specify -c to use -C"); 380 if (Kflag && !usetls) 381 errx(1, "you must specify -c to use -K"); 382 if (tls_cachanged && !usetls) 383 errx(1, "you must specify -c to use -R"); 384 if (tls_expecthash && !usetls) 385 errx(1, "you must specify -c to use -H"); 386 if (tls_expectname && !usetls) 387 errx(1, "you must specify -c to use -e"); 388 389 /* Get name of temporary socket for unix datagram client */ 390 if ((family == AF_UNIX) && uflag && !lflag) { 391 if (sflag) { 392 unix_dg_tmp_socket = sflag; 393 } else { 394 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 395 UNIX_DG_TMP_SOCKET_SIZE); 396 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 397 err(1, "mktemp"); 398 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 399 } 400 } 401 402 /* Initialize addrinfo structure. */ 403 if (family != AF_UNIX) { 404 memset(&hints, 0, sizeof(struct addrinfo)); 405 hints.ai_family = family; 406 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 407 hints.ai_protocol = uflag ? IPPROTO_UDP : 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 (lflag) 417 errx(1, "no proxy support for listen"); 418 419 if (family == AF_UNIX) 420 errx(1, "no proxy support for unix sockets"); 421 422 /* XXX IPv6 transport to proxy would probably work */ 423 if (family == AF_INET6) 424 errx(1, "no proxy support for IPv6"); 425 426 if (sflag) 427 errx(1, "no proxy support for local source address"); 428 429 proxyhost = strsep(&proxy, ":"); 430 proxyport = proxy; 431 432 memset(&proxyhints, 0, sizeof(struct addrinfo)); 433 proxyhints.ai_family = family; 434 proxyhints.ai_socktype = SOCK_STREAM; 435 proxyhints.ai_protocol = IPPROTO_TCP; 436 if (nflag) 437 proxyhints.ai_flags |= AI_NUMERICHOST; 438 } 439 440 if (usetls) { 441 if (Pflag) { 442 if (pledge("stdio inet dns tty rpath", NULL) == -1) 443 err(1, "pledge"); 444 } else if (pledge("stdio inet dns rpath", NULL) == -1) 445 err(1, "pledge"); 446 447 if (tls_init() == -1) 448 errx(1, "unable to initialize TLS"); 449 if ((tls_cfg = tls_config_new()) == NULL) 450 errx(1, "unable to allocate TLS config"); 451 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 452 errx(1, "%s", tls_config_error(tls_cfg)); 453 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 454 errx(1, "%s", tls_config_error(tls_cfg)); 455 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 456 errx(1, "%s", tls_config_error(tls_cfg)); 457 if (TLSopt & TLS_LEGACY) { 458 tls_config_set_protocols(tls_cfg, TLS_PROTOCOLS_ALL); 459 tls_config_set_ciphers(tls_cfg, "all"); 460 } 461 if (!lflag && (TLSopt & TLS_CCERT)) 462 errx(1, "clientcert is only valid with -l"); 463 if (TLSopt & TLS_NONAME) 464 tls_config_insecure_noverifyname(tls_cfg); 465 if (TLSopt & TLS_NOVERIFY) { 466 if (tls_expecthash != NULL) 467 errx(1, "-H and -T noverify may not be used" 468 "together"); 469 tls_config_insecure_noverifycert(tls_cfg); 470 } 471 472 if (Pflag) { 473 if (pledge("stdio inet dns tty", NULL) == -1) 474 err(1, "pledge"); 475 } else if (pledge("stdio inet dns", NULL) == -1) 476 err(1, "pledge"); 477 } 478 if (lflag) { 479 struct tls *tls_cctx = NULL; 480 int connfd; 481 ret = 0; 482 483 if (family == AF_UNIX) { 484 if (uflag) 485 s = unix_bind(host, 0); 486 else 487 s = unix_listen(host); 488 } 489 490 if (usetls) { 491 tls_config_verify_client_optional(tls_cfg); 492 if ((tls_ctx = tls_server()) == NULL) 493 errx(1, "tls server creation failed"); 494 if (tls_configure(tls_ctx, tls_cfg) == -1) 495 errx(1, "tls configuration failed (%s)", 496 tls_error(tls_ctx)); 497 } 498 /* Allow only one connection at a time, but stay alive. */ 499 for (;;) { 500 if (family != AF_UNIX) 501 s = local_listen(host, uport, hints); 502 if (s < 0) 503 err(1, NULL); 504 /* 505 * For UDP and -k, don't connect the socket, let it 506 * receive datagrams from multiple socket pairs. 507 */ 508 if (uflag && kflag) 509 readwrite(s, NULL); 510 /* 511 * For UDP and not -k, we will use recvfrom() initially 512 * to wait for a caller, then use the regular functions 513 * to talk to the caller. 514 */ 515 else if (uflag && !kflag) { 516 int rv, plen; 517 char buf[16384]; 518 struct sockaddr_storage z; 519 520 len = sizeof(z); 521 plen = 2048; 522 rv = recvfrom(s, buf, plen, MSG_PEEK, 523 (struct sockaddr *)&z, &len); 524 if (rv < 0) 525 err(1, "recvfrom"); 526 527 rv = connect(s, (struct sockaddr *)&z, len); 528 if (rv < 0) 529 err(1, "connect"); 530 531 if (vflag) 532 report_connect((struct sockaddr *)&z, len, NULL); 533 534 readwrite(s, NULL); 535 } else { 536 len = sizeof(cliaddr); 537 connfd = accept4(s, (struct sockaddr *)&cliaddr, 538 &len, SOCK_NONBLOCK); 539 if (connfd == -1) { 540 /* For now, all errnos are fatal */ 541 err(1, "accept"); 542 } 543 if (vflag) 544 report_connect((struct sockaddr *)&cliaddr, len, 545 family == AF_UNIX ? host : NULL); 546 if ((usetls) && 547 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 548 readwrite(connfd, tls_cctx); 549 if (!usetls) 550 readwrite(connfd, NULL); 551 if (tls_cctx) { 552 int i; 553 554 do { 555 i = tls_close(tls_cctx); 556 } while (i == TLS_WANT_POLLIN || 557 i == TLS_WANT_POLLOUT); 558 tls_free(tls_cctx); 559 tls_cctx = NULL; 560 } 561 close(connfd); 562 } 563 if (family != AF_UNIX) 564 close(s); 565 else if (uflag) { 566 if (connect(s, NULL, 0) < 0) 567 err(1, "connect"); 568 } 569 570 if (!kflag) 571 break; 572 } 573 } else if (family == AF_UNIX) { 574 ret = 0; 575 576 if ((s = unix_connect(host)) > 0 && !zflag) { 577 readwrite(s, NULL); 578 close(s); 579 } else 580 ret = 1; 581 582 if (uflag) 583 unlink(unix_dg_tmp_socket); 584 exit(ret); 585 586 } else { 587 int i = 0; 588 589 /* Construct the portlist[] array. */ 590 build_ports(uport); 591 592 /* Cycle through portlist, connecting to each port. */ 593 for (s = -1, i = 0; portlist[i] != NULL; i++) { 594 if (s != -1) 595 close(s); 596 597 if (usetls) { 598 if ((tls_ctx = tls_client()) == NULL) 599 errx(1, "tls client creation failed"); 600 if (tls_configure(tls_ctx, tls_cfg) == -1) 601 errx(1, "tls configuration failed (%s)", 602 tls_error(tls_ctx)); 603 } 604 if (xflag) 605 s = socks_connect(host, portlist[i], hints, 606 proxyhost, proxyport, proxyhints, socksv, 607 Pflag); 608 else 609 s = remote_connect(host, portlist[i], hints); 610 611 if (s == -1) 612 continue; 613 614 ret = 0; 615 if (vflag || zflag) { 616 /* For UDP, make sure we are connected. */ 617 if (uflag) { 618 if (udptest(s) == -1) { 619 ret = 1; 620 continue; 621 } 622 } 623 624 /* Don't look up port if -n. */ 625 if (nflag) 626 sv = NULL; 627 else { 628 sv = getservbyport( 629 ntohs(atoi(portlist[i])), 630 uflag ? "udp" : "tcp"); 631 } 632 633 fprintf(stderr, 634 "Connection to %s %s port [%s/%s] " 635 "succeeded!\n", host, portlist[i], 636 uflag ? "udp" : "tcp", 637 sv ? sv->s_name : "*"); 638 } 639 if (Fflag) 640 fdpass(s); 641 else { 642 if (usetls) 643 tls_setup_client(tls_ctx, s, host); 644 if (!zflag) 645 readwrite(s, tls_ctx); 646 if (tls_ctx) { 647 int j; 648 649 do { 650 j = tls_close(tls_ctx); 651 } while (j == TLS_WANT_POLLIN || 652 j == TLS_WANT_POLLOUT); 653 tls_free(tls_ctx); 654 tls_ctx = NULL; 655 } 656 } 657 } 658 } 659 660 if (s != -1) 661 close(s); 662 663 tls_config_free(tls_cfg); 664 665 exit(ret); 666 } 667 668 /* 669 * unix_bind() 670 * Returns a unix socket bound to the given path 671 */ 672 int 673 unix_bind(char *path, int flags) 674 { 675 struct sockaddr_un s_un; 676 int s, save_errno; 677 678 /* Create unix domain socket. */ 679 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 680 0)) < 0) 681 return (-1); 682 683 memset(&s_un, 0, sizeof(struct sockaddr_un)); 684 s_un.sun_family = AF_UNIX; 685 686 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 687 sizeof(s_un.sun_path)) { 688 close(s); 689 errno = ENAMETOOLONG; 690 return (-1); 691 } 692 693 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 694 save_errno = errno; 695 close(s); 696 errno = save_errno; 697 return (-1); 698 } 699 return (s); 700 } 701 702 void 703 tls_setup_client(struct tls *tls_ctx, int s, char *host) 704 { 705 int i; 706 707 if (tls_connect_socket(tls_ctx, s, 708 tls_expectname ? tls_expectname : host) == -1) { 709 errx(1, "tls connection failed (%s)", 710 tls_error(tls_ctx)); 711 } 712 do { 713 if ((i = tls_handshake(tls_ctx)) == -1) 714 errx(1, "tls handshake failed (%s)", 715 tls_error(tls_ctx)); 716 } while (i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 717 if (vflag) 718 report_tls(tls_ctx, host, tls_expectname); 719 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 720 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 721 errx(1, "peer certificate is not %s", tls_expecthash); 722 } 723 724 struct tls * 725 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 726 { 727 struct tls *tls_cctx; 728 729 if (tls_accept_socket(tls_ctx, &tls_cctx, 730 connfd) == -1) { 731 warnx("tls accept failed (%s)", 732 tls_error(tls_ctx)); 733 tls_cctx = NULL; 734 } else { 735 int i; 736 737 do { 738 if ((i = tls_handshake(tls_cctx)) == -1) 739 warnx("tls handshake failed (%s)", 740 tls_error(tls_cctx)); 741 } while(i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 742 } 743 if (tls_cctx) { 744 int gotcert = tls_peer_cert_provided(tls_cctx); 745 746 if (vflag && gotcert) 747 report_tls(tls_cctx, host, tls_expectname); 748 if ((TLSopt & TLS_CCERT) && !gotcert) 749 warnx("No client certificate provided"); 750 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 751 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 752 warnx("peer certificate is not %s", tls_expecthash); 753 else if (gotcert && tls_expectname && 754 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 755 warnx("name (%s) not found in client cert", 756 tls_expectname); 757 else { 758 return tls_cctx; 759 } 760 } 761 return NULL; 762 } 763 764 /* 765 * unix_connect() 766 * Returns a socket connected to a local unix socket. Returns -1 on failure. 767 */ 768 int 769 unix_connect(char *path) 770 { 771 struct sockaddr_un s_un; 772 int s, save_errno; 773 774 if (uflag) { 775 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 776 return (-1); 777 } else { 778 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 779 return (-1); 780 } 781 782 memset(&s_un, 0, sizeof(struct sockaddr_un)); 783 s_un.sun_family = AF_UNIX; 784 785 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 786 sizeof(s_un.sun_path)) { 787 close(s); 788 errno = ENAMETOOLONG; 789 return (-1); 790 } 791 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 792 save_errno = errno; 793 close(s); 794 errno = save_errno; 795 return (-1); 796 } 797 return (s); 798 799 } 800 801 /* 802 * unix_listen() 803 * Create a unix domain socket, and listen on it. 804 */ 805 int 806 unix_listen(char *path) 807 { 808 int s; 809 if ((s = unix_bind(path, 0)) < 0) 810 return (-1); 811 812 if (listen(s, 5) < 0) { 813 close(s); 814 return (-1); 815 } 816 return (s); 817 } 818 819 /* 820 * remote_connect() 821 * Returns a socket connected to a remote host. Properly binds to a local 822 * port or source address if needed. Returns -1 on failure. 823 */ 824 int 825 remote_connect(const char *host, const char *port, struct addrinfo hints) 826 { 827 struct addrinfo *res, *res0; 828 int s = -1, error, on = 1, save_errno; 829 830 if ((error = getaddrinfo(host, port, &hints, &res0))) 831 errx(1, "getaddrinfo: %s", gai_strerror(error)); 832 833 for (res = res0; res; res = res->ai_next) { 834 if ((s = socket(res->ai_family, res->ai_socktype | 835 SOCK_NONBLOCK, res->ai_protocol)) < 0) 836 continue; 837 838 /* Bind to a local port or source address if specified. */ 839 if (sflag || pflag) { 840 struct addrinfo ahints, *ares; 841 842 /* try SO_BINDANY, but don't insist */ 843 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 844 memset(&ahints, 0, sizeof(struct addrinfo)); 845 ahints.ai_family = res->ai_family; 846 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 847 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 848 ahints.ai_flags = AI_PASSIVE; 849 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 850 errx(1, "getaddrinfo: %s", gai_strerror(error)); 851 852 if (bind(s, (struct sockaddr *)ares->ai_addr, 853 ares->ai_addrlen) < 0) 854 err(1, "bind failed"); 855 freeaddrinfo(ares); 856 } 857 858 set_common_sockopts(s, res->ai_family); 859 860 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 861 break; 862 if (vflag) 863 warn("connect to %s port %s (%s) failed", host, port, 864 uflag ? "udp" : "tcp"); 865 866 save_errno = errno; 867 close(s); 868 errno = save_errno; 869 s = -1; 870 } 871 872 freeaddrinfo(res0); 873 874 return (s); 875 } 876 877 int 878 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 879 { 880 struct pollfd pfd; 881 socklen_t optlen; 882 int optval; 883 int ret; 884 885 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 886 pfd.fd = s; 887 pfd.events = POLLOUT; 888 if ((ret = poll(&pfd, 1, timeout)) == 1) { 889 optlen = sizeof(optval); 890 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 891 &optval, &optlen)) == 0) { 892 errno = optval; 893 ret = optval == 0 ? 0 : -1; 894 } 895 } else if (ret == 0) { 896 errno = ETIMEDOUT; 897 ret = -1; 898 } else 899 err(1, "poll failed"); 900 } 901 902 return (ret); 903 } 904 905 /* 906 * local_listen() 907 * Returns a socket listening on a local port, binds to specified source 908 * address. Returns -1 on failure. 909 */ 910 int 911 local_listen(char *host, char *port, struct addrinfo hints) 912 { 913 struct addrinfo *res, *res0; 914 int s = -1, ret, x = 1, save_errno; 915 int error; 916 917 /* Allow nodename to be null. */ 918 hints.ai_flags |= AI_PASSIVE; 919 920 /* 921 * In the case of binding to a wildcard address 922 * default to binding to an ipv4 address. 923 */ 924 if (host == NULL && hints.ai_family == AF_UNSPEC) 925 hints.ai_family = AF_INET; 926 927 if ((error = getaddrinfo(host, port, &hints, &res0))) 928 errx(1, "getaddrinfo: %s", gai_strerror(error)); 929 930 for (res = res0; res; res = res->ai_next) { 931 if ((s = socket(res->ai_family, res->ai_socktype, 932 res->ai_protocol)) < 0) 933 continue; 934 935 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 936 if (ret == -1) 937 err(1, NULL); 938 939 set_common_sockopts(s, res->ai_family); 940 941 if (bind(s, (struct sockaddr *)res->ai_addr, 942 res->ai_addrlen) == 0) 943 break; 944 945 save_errno = errno; 946 close(s); 947 errno = save_errno; 948 s = -1; 949 } 950 951 if (!uflag && s != -1) { 952 if (listen(s, 1) < 0) 953 err(1, "listen"); 954 } 955 956 freeaddrinfo(res0); 957 958 return (s); 959 } 960 961 /* 962 * readwrite() 963 * Loop that polls on the network file descriptor and stdin. 964 */ 965 void 966 readwrite(int net_fd, struct tls *tls_ctx) 967 { 968 struct pollfd pfd[4]; 969 int stdin_fd = STDIN_FILENO; 970 int stdout_fd = STDOUT_FILENO; 971 unsigned char netinbuf[BUFSIZE]; 972 size_t netinbufpos = 0; 973 unsigned char stdinbuf[BUFSIZE]; 974 size_t stdinbufpos = 0; 975 int n, num_fds; 976 ssize_t ret; 977 978 /* don't read from stdin if requested */ 979 if (dflag) 980 stdin_fd = -1; 981 982 /* stdin */ 983 pfd[POLL_STDIN].fd = stdin_fd; 984 pfd[POLL_STDIN].events = POLLIN; 985 986 /* network out */ 987 pfd[POLL_NETOUT].fd = net_fd; 988 pfd[POLL_NETOUT].events = 0; 989 990 /* network in */ 991 pfd[POLL_NETIN].fd = net_fd; 992 pfd[POLL_NETIN].events = POLLIN; 993 994 /* stdout */ 995 pfd[POLL_STDOUT].fd = stdout_fd; 996 pfd[POLL_STDOUT].events = 0; 997 998 while (1) { 999 /* both inputs are gone, buffers are empty, we are done */ 1000 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1001 stdinbufpos == 0 && netinbufpos == 0) { 1002 close(net_fd); 1003 return; 1004 } 1005 /* both outputs are gone, we can't continue */ 1006 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 1007 close(net_fd); 1008 return; 1009 } 1010 /* listen and net in gone, queues empty, done */ 1011 if (lflag && pfd[POLL_NETIN].fd == -1 && 1012 stdinbufpos == 0 && netinbufpos == 0) { 1013 close(net_fd); 1014 return; 1015 } 1016 1017 /* help says -i is for "wait between lines sent". We read and 1018 * write arbitrary amounts of data, and we don't want to start 1019 * scanning for newlines, so this is as good as it gets */ 1020 if (iflag) 1021 sleep(iflag); 1022 1023 /* poll */ 1024 num_fds = poll(pfd, 4, timeout); 1025 1026 /* treat poll errors */ 1027 if (num_fds == -1) { 1028 close(net_fd); 1029 err(1, "polling error"); 1030 } 1031 1032 /* timeout happened */ 1033 if (num_fds == 0) 1034 return; 1035 1036 /* treat socket error conditions */ 1037 for (n = 0; n < 4; n++) { 1038 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1039 pfd[n].fd = -1; 1040 } 1041 } 1042 /* reading is possible after HUP */ 1043 if (pfd[POLL_STDIN].events & POLLIN && 1044 pfd[POLL_STDIN].revents & POLLHUP && 1045 !(pfd[POLL_STDIN].revents & POLLIN)) 1046 pfd[POLL_STDIN].fd = -1; 1047 1048 if (pfd[POLL_NETIN].events & POLLIN && 1049 pfd[POLL_NETIN].revents & POLLHUP && 1050 !(pfd[POLL_NETIN].revents & POLLIN)) 1051 pfd[POLL_NETIN].fd = -1; 1052 1053 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1054 if (Nflag) 1055 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1056 pfd[POLL_NETOUT].fd = -1; 1057 } 1058 /* if HUP, stop watching stdout */ 1059 if (pfd[POLL_STDOUT].revents & POLLHUP) 1060 pfd[POLL_STDOUT].fd = -1; 1061 /* if no net out, stop watching stdin */ 1062 if (pfd[POLL_NETOUT].fd == -1) 1063 pfd[POLL_STDIN].fd = -1; 1064 /* if no stdout, stop watching net in */ 1065 if (pfd[POLL_STDOUT].fd == -1) { 1066 if (pfd[POLL_NETIN].fd != -1) 1067 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1068 pfd[POLL_NETIN].fd = -1; 1069 } 1070 1071 /* try to read from stdin */ 1072 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1073 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1074 &stdinbufpos, NULL); 1075 if (ret == TLS_WANT_POLLIN) 1076 pfd[POLL_STDIN].events = POLLIN; 1077 else if (ret == TLS_WANT_POLLOUT) 1078 pfd[POLL_STDIN].events = POLLOUT; 1079 else if (ret == 0 || ret == -1) 1080 pfd[POLL_STDIN].fd = -1; 1081 /* read something - poll net out */ 1082 if (stdinbufpos > 0) 1083 pfd[POLL_NETOUT].events = POLLOUT; 1084 /* filled buffer - remove self from polling */ 1085 if (stdinbufpos == BUFSIZE) 1086 pfd[POLL_STDIN].events = 0; 1087 } 1088 /* try to write to network */ 1089 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1090 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1091 &stdinbufpos, tls_ctx); 1092 if (ret == TLS_WANT_POLLIN) 1093 pfd[POLL_NETOUT].events = POLLIN; 1094 else if (ret == TLS_WANT_POLLOUT) 1095 pfd[POLL_NETOUT].events = POLLOUT; 1096 else if (ret == -1) 1097 pfd[POLL_NETOUT].fd = -1; 1098 /* buffer empty - remove self from polling */ 1099 if (stdinbufpos == 0) 1100 pfd[POLL_NETOUT].events = 0; 1101 /* buffer no longer full - poll stdin again */ 1102 if (stdinbufpos < BUFSIZE) 1103 pfd[POLL_STDIN].events = POLLIN; 1104 } 1105 /* try to read from network */ 1106 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1107 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1108 &netinbufpos, tls_ctx); 1109 if (ret == TLS_WANT_POLLIN) 1110 pfd[POLL_NETIN].events = POLLIN; 1111 else if (ret == TLS_WANT_POLLOUT) 1112 pfd[POLL_NETIN].events = POLLOUT; 1113 else if (ret == -1) 1114 pfd[POLL_NETIN].fd = -1; 1115 /* eof on net in - remove from pfd */ 1116 if (ret == 0) { 1117 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1118 pfd[POLL_NETIN].fd = -1; 1119 } 1120 /* read something - poll stdout */ 1121 if (netinbufpos > 0) 1122 pfd[POLL_STDOUT].events = POLLOUT; 1123 /* filled buffer - remove self from polling */ 1124 if (netinbufpos == BUFSIZE) 1125 pfd[POLL_NETIN].events = 0; 1126 /* handle telnet */ 1127 if (tflag) 1128 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1129 netinbufpos); 1130 } 1131 /* try to write to stdout */ 1132 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1133 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1134 &netinbufpos, NULL); 1135 if (ret == TLS_WANT_POLLIN) 1136 pfd[POLL_STDOUT].events = POLLIN; 1137 else if (ret == TLS_WANT_POLLOUT) 1138 pfd[POLL_STDOUT].events = POLLOUT; 1139 else if (ret == -1) 1140 pfd[POLL_STDOUT].fd = -1; 1141 /* buffer empty - remove self from polling */ 1142 if (netinbufpos == 0) 1143 pfd[POLL_STDOUT].events = 0; 1144 /* buffer no longer full - poll net in again */ 1145 if (netinbufpos < BUFSIZE) 1146 pfd[POLL_NETIN].events = POLLIN; 1147 } 1148 1149 /* stdin gone and queue empty? */ 1150 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1151 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1152 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1153 pfd[POLL_NETOUT].fd = -1; 1154 } 1155 /* net in gone and queue empty? */ 1156 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1157 pfd[POLL_STDOUT].fd = -1; 1158 } 1159 } 1160 } 1161 1162 ssize_t 1163 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1164 { 1165 ssize_t n; 1166 ssize_t adjust; 1167 1168 if (tls) 1169 n = tls_write(tls, buf, *bufpos); 1170 else { 1171 n = write(fd, buf, *bufpos); 1172 /* don't treat EAGAIN, EINTR as error */ 1173 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1174 n = TLS_WANT_POLLOUT; 1175 } 1176 if (n <= 0) 1177 return n; 1178 /* adjust buffer */ 1179 adjust = *bufpos - n; 1180 if (adjust > 0) 1181 memmove(buf, buf + n, adjust); 1182 *bufpos -= n; 1183 return n; 1184 } 1185 1186 ssize_t 1187 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1188 { 1189 size_t num = BUFSIZE - *bufpos; 1190 ssize_t n; 1191 1192 if (tls) 1193 n = tls_read(tls, buf + *bufpos, num); 1194 else { 1195 n = read(fd, buf + *bufpos, num); 1196 /* don't treat EAGAIN, EINTR as error */ 1197 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1198 n = TLS_WANT_POLLIN; 1199 } 1200 if (n <= 0) 1201 return n; 1202 *bufpos += n; 1203 return n; 1204 } 1205 1206 /* 1207 * fdpass() 1208 * Pass the connected file descriptor to stdout and exit. 1209 */ 1210 void 1211 fdpass(int nfd) 1212 { 1213 struct msghdr mh; 1214 union { 1215 struct cmsghdr hdr; 1216 char buf[CMSG_SPACE(sizeof(int))]; 1217 } cmsgbuf; 1218 struct cmsghdr *cmsg; 1219 struct iovec iov; 1220 char c = '\0'; 1221 ssize_t r; 1222 struct pollfd pfd; 1223 1224 /* Avoid obvious stupidity */ 1225 if (isatty(STDOUT_FILENO)) 1226 errx(1, "Cannot pass file descriptor to tty"); 1227 1228 bzero(&mh, sizeof(mh)); 1229 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1230 bzero(&iov, sizeof(iov)); 1231 1232 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1233 mh.msg_controllen = sizeof(cmsgbuf.buf); 1234 cmsg = CMSG_FIRSTHDR(&mh); 1235 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1236 cmsg->cmsg_level = SOL_SOCKET; 1237 cmsg->cmsg_type = SCM_RIGHTS; 1238 *(int *)CMSG_DATA(cmsg) = nfd; 1239 1240 iov.iov_base = &c; 1241 iov.iov_len = 1; 1242 mh.msg_iov = &iov; 1243 mh.msg_iovlen = 1; 1244 1245 bzero(&pfd, sizeof(pfd)); 1246 pfd.fd = STDOUT_FILENO; 1247 pfd.events = POLLOUT; 1248 for (;;) { 1249 r = sendmsg(STDOUT_FILENO, &mh, 0); 1250 if (r == -1) { 1251 if (errno == EAGAIN || errno == EINTR) { 1252 if (poll(&pfd, 1, -1) == -1) 1253 err(1, "poll"); 1254 continue; 1255 } 1256 err(1, "sendmsg"); 1257 } else if (r != 1) 1258 errx(1, "sendmsg: unexpected return value %zd", r); 1259 else 1260 break; 1261 } 1262 exit(0); 1263 } 1264 1265 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1266 void 1267 atelnet(int nfd, unsigned char *buf, unsigned int size) 1268 { 1269 unsigned char *p, *end; 1270 unsigned char obuf[4]; 1271 1272 if (size < 3) 1273 return; 1274 end = buf + size - 2; 1275 1276 for (p = buf; p < end; p++) { 1277 if (*p != IAC) 1278 continue; 1279 1280 obuf[0] = IAC; 1281 p++; 1282 if ((*p == WILL) || (*p == WONT)) 1283 obuf[1] = DONT; 1284 else if ((*p == DO) || (*p == DONT)) 1285 obuf[1] = WONT; 1286 else 1287 continue; 1288 1289 p++; 1290 obuf[2] = *p; 1291 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1292 warn("Write Error!"); 1293 } 1294 } 1295 1296 1297 int 1298 strtoport(char *portstr, int udp) 1299 { 1300 struct servent *entry; 1301 const char *errstr; 1302 char *proto; 1303 int port = -1; 1304 1305 proto = udp ? "udp" : "tcp"; 1306 1307 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1308 if (errstr == NULL) 1309 return port; 1310 if (errno != EINVAL) 1311 errx(1, "port number %s: %s", errstr, portstr); 1312 if ((entry = getservbyname(portstr, proto)) == NULL) 1313 errx(1, "service \"%s\" unknown", portstr); 1314 return ntohs(entry->s_port); 1315 } 1316 1317 /* 1318 * build_ports() 1319 * Build an array of ports in portlist[], listing each port 1320 * that we should try to connect to. 1321 */ 1322 void 1323 build_ports(char *p) 1324 { 1325 char *n; 1326 int hi, lo, cp; 1327 int x = 0; 1328 1329 if ((n = strchr(p, '-')) != NULL) { 1330 *n = '\0'; 1331 n++; 1332 1333 /* Make sure the ports are in order: lowest->highest. */ 1334 hi = strtoport(n, uflag); 1335 lo = strtoport(p, uflag); 1336 if (lo > hi) { 1337 cp = hi; 1338 hi = lo; 1339 lo = cp; 1340 } 1341 1342 /* 1343 * Initialize portlist with a random permutation. Based on 1344 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1345 */ 1346 if (rflag) { 1347 for (x = 0; x <= hi - lo; x++) { 1348 cp = arc4random_uniform(x + 1); 1349 portlist[x] = portlist[cp]; 1350 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1351 err(1, "asprintf"); 1352 } 1353 } else { /* Load ports sequentially. */ 1354 for (cp = lo; cp <= hi; cp++) { 1355 if (asprintf(&portlist[x], "%d", cp) < 0) 1356 err(1, "asprintf"); 1357 x++; 1358 } 1359 } 1360 } else { 1361 char *tmp; 1362 1363 hi = strtoport(p, uflag); 1364 if (asprintf(&tmp, "%d", hi) != -1) 1365 portlist[0] = tmp; 1366 else 1367 err(1, NULL); 1368 } 1369 } 1370 1371 /* 1372 * udptest() 1373 * Do a few writes to see if the UDP port is there. 1374 * Fails once PF state table is full. 1375 */ 1376 int 1377 udptest(int s) 1378 { 1379 int i, ret; 1380 1381 for (i = 0; i <= 3; i++) { 1382 if (write(s, "X", 1) == 1) 1383 ret = 1; 1384 else 1385 ret = -1; 1386 } 1387 return (ret); 1388 } 1389 1390 void 1391 set_common_sockopts(int s, int af) 1392 { 1393 int x = 1; 1394 1395 if (Sflag) { 1396 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1397 &x, sizeof(x)) == -1) 1398 err(1, NULL); 1399 } 1400 if (Dflag) { 1401 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1402 &x, sizeof(x)) == -1) 1403 err(1, NULL); 1404 } 1405 if (Tflag != -1) { 1406 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1407 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1408 err(1, "set IP ToS"); 1409 1410 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1411 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1412 err(1, "set IPv6 traffic class"); 1413 } 1414 if (Iflag) { 1415 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1416 &Iflag, sizeof(Iflag)) == -1) 1417 err(1, "set TCP receive buffer size"); 1418 } 1419 if (Oflag) { 1420 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1421 &Oflag, sizeof(Oflag)) == -1) 1422 err(1, "set TCP send buffer size"); 1423 } 1424 1425 if (ttl != -1) { 1426 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1427 IP_TTL, &ttl, sizeof(ttl))) 1428 err(1, "set IP TTL"); 1429 1430 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1431 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1432 err(1, "set IPv6 unicast hops"); 1433 } 1434 1435 if (minttl != -1) { 1436 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1437 IP_MINTTL, &minttl, sizeof(minttl))) 1438 err(1, "set IP min TTL"); 1439 1440 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1441 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1442 err(1, "set IPv6 min hop count"); 1443 } 1444 } 1445 1446 int 1447 map_tos(char *s, int *val) 1448 { 1449 /* DiffServ Codepoints and other TOS mappings */ 1450 const struct toskeywords { 1451 const char *keyword; 1452 int val; 1453 } *t, toskeywords[] = { 1454 { "af11", IPTOS_DSCP_AF11 }, 1455 { "af12", IPTOS_DSCP_AF12 }, 1456 { "af13", IPTOS_DSCP_AF13 }, 1457 { "af21", IPTOS_DSCP_AF21 }, 1458 { "af22", IPTOS_DSCP_AF22 }, 1459 { "af23", IPTOS_DSCP_AF23 }, 1460 { "af31", IPTOS_DSCP_AF31 }, 1461 { "af32", IPTOS_DSCP_AF32 }, 1462 { "af33", IPTOS_DSCP_AF33 }, 1463 { "af41", IPTOS_DSCP_AF41 }, 1464 { "af42", IPTOS_DSCP_AF42 }, 1465 { "af43", IPTOS_DSCP_AF43 }, 1466 { "critical", IPTOS_PREC_CRITIC_ECP }, 1467 { "cs0", IPTOS_DSCP_CS0 }, 1468 { "cs1", IPTOS_DSCP_CS1 }, 1469 { "cs2", IPTOS_DSCP_CS2 }, 1470 { "cs3", IPTOS_DSCP_CS3 }, 1471 { "cs4", IPTOS_DSCP_CS4 }, 1472 { "cs5", IPTOS_DSCP_CS5 }, 1473 { "cs6", IPTOS_DSCP_CS6 }, 1474 { "cs7", IPTOS_DSCP_CS7 }, 1475 { "ef", IPTOS_DSCP_EF }, 1476 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1477 { "lowdelay", IPTOS_LOWDELAY }, 1478 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1479 { "reliability", IPTOS_RELIABILITY }, 1480 { "throughput", IPTOS_THROUGHPUT }, 1481 { NULL, -1 }, 1482 }; 1483 1484 for (t = toskeywords; t->keyword != NULL; t++) { 1485 if (strcmp(s, t->keyword) == 0) { 1486 *val = t->val; 1487 return (1); 1488 } 1489 } 1490 1491 return (0); 1492 } 1493 1494 int 1495 map_tls(char *s, int *val) 1496 { 1497 const struct tlskeywords { 1498 const char *keyword; 1499 int val; 1500 } *t, tlskeywords[] = { 1501 { "tlslegacy", TLS_LEGACY }, 1502 { "noverify", TLS_NOVERIFY }, 1503 { "noname", TLS_NONAME }, 1504 { "clientcert", TLS_CCERT}, 1505 { NULL, -1 }, 1506 }; 1507 1508 for (t = tlskeywords; t->keyword != NULL; t++) { 1509 if (strcmp(s, t->keyword) == 0) { 1510 *val |= t->val; 1511 return (1); 1512 } 1513 } 1514 return (0); 1515 } 1516 1517 void 1518 report_tls(struct tls * tls_ctx, char * host, char *tls_expectname) 1519 { 1520 time_t t; 1521 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1522 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1523 fprintf(stderr, "Peer name: %s\n", 1524 tls_expectname ? tls_expectname : host); 1525 if (tls_peer_cert_subject(tls_ctx)) 1526 fprintf(stderr, "Subject: %s\n", 1527 tls_peer_cert_subject(tls_ctx)); 1528 if (tls_peer_cert_issuer(tls_ctx)) 1529 fprintf(stderr, "Issuer: %s\n", 1530 tls_peer_cert_issuer(tls_ctx)); 1531 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1532 fprintf(stderr, "Valid From: %s", ctime(&t)); 1533 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1534 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1535 if (tls_peer_cert_hash(tls_ctx)) 1536 fprintf(stderr, "Cert Hash: %s\n", 1537 tls_peer_cert_hash(tls_ctx)); 1538 } 1539 1540 void 1541 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1542 { 1543 char remote_host[NI_MAXHOST]; 1544 char remote_port[NI_MAXSERV]; 1545 int herr; 1546 int flags = NI_NUMERICSERV; 1547 1548 if (path != NULL) { 1549 fprintf(stderr, "Connection on %s received!\n", path); 1550 return; 1551 } 1552 1553 if (nflag) 1554 flags |= NI_NUMERICHOST; 1555 1556 if ((herr = getnameinfo(sa, salen, 1557 remote_host, sizeof(remote_host), 1558 remote_port, sizeof(remote_port), 1559 flags)) != 0) { 1560 if (herr == EAI_SYSTEM) 1561 err(1, "getnameinfo"); 1562 else 1563 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1564 } 1565 1566 fprintf(stderr, 1567 "Connection from %s %s " 1568 "received!\n", remote_host, remote_port); 1569 } 1570 1571 void 1572 help(void) 1573 { 1574 usage(0); 1575 fprintf(stderr, "\tCommand Summary:\n\ 1576 \t-4 Use IPv4\n\ 1577 \t-6 Use IPv6\n\ 1578 \t-C certfile Public key file\n\ 1579 \t-c Use TLS\n\ 1580 \t-D Enable the debug socket option\n\ 1581 \t-d Detach from stdin\n\ 1582 \t-e name\t Required name in peer certificate\n\ 1583 \t-F Pass socket fd\n\ 1584 \t-H hash\t Hash string of peer certificate\n\ 1585 \t-h This help text\n\ 1586 \t-I length TCP receive buffer length\n\ 1587 \t-i interval Delay interval for lines sent, ports scanned\n\ 1588 \t-K keyfile Private key file\n\ 1589 \t-k Keep inbound sockets open for multiple connects\n\ 1590 \t-l Listen mode, for inbound connects\n\ 1591 \t-M ttl Outgoing TTL / Hop Limit\n\ 1592 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1593 \t-N Shutdown the network socket after EOF on stdin\n\ 1594 \t-n Suppress name/port resolutions\n\ 1595 \t-O length TCP send buffer length\n\ 1596 \t-P proxyuser\tUsername for proxy authentication\n\ 1597 \t-p port\t Specify local port for remote connects\n\ 1598 \t-R CAfile CA bundle\n\ 1599 \t-r Randomize remote ports\n\ 1600 \t-S Enable the TCP MD5 signature option\n\ 1601 \t-s source Local source address\n\ 1602 \t-T keyword TOS value or TLS options\n\ 1603 \t-t Answer TELNET negotiation\n\ 1604 \t-U Use UNIX domain socket\n\ 1605 \t-u UDP mode\n\ 1606 \t-V rtable Specify alternate routing table\n\ 1607 \t-v Verbose\n\ 1608 \t-w timeout Timeout for connects and final net reads\n\ 1609 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1610 \t-x addr[:port]\tSpecify proxy address and port\n\ 1611 \t-z Zero-I/O mode [used for scanning]\n\ 1612 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1613 exit(1); 1614 } 1615 1616 void 1617 usage(int ret) 1618 { 1619 fprintf(stderr, 1620 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1621 "[-H hash] [-I length]\n" 1622 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1623 "\t [-P proxy_username] [-p source_port] [-R CAfile] [-s source]\n" 1624 "\t [-T keyword] [-V rtable] [-w timeout] [-X proxy_protocol]\n" 1625 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1626 if (ret) 1627 exit(1); 1628 } 1629