openbsd-nc.c (43959B)
1 /* $OpenBSD: netcat.c,v 1.181 2017/04/16 15:11:01 deraadt 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 <linux/in6.h> 46 47 #include <err.h> 48 #include <errno.h> 49 #include <limits.h> 50 #include <netdb.h> 51 #include <poll.h> 52 #include <signal.h> 53 #include <stdarg.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <time.h> 58 #include <unistd.h> 59 #include <tls.h> 60 61 #include <bsd/stdio.h> 62 #include <bsd/stdlib.h> 63 #include <bsd/string.h> 64 65 #include "atomicio.h" 66 #include "utils.h" 67 68 #define PORT_MAX 65535 69 #define UNIX_DG_TMP_SOCKET_SIZE 19 70 71 #define POLL_STDIN 0 72 #define POLL_NETOUT 1 73 #define POLL_NETIN 2 74 #define POLL_STDOUT 3 75 #define BUFSIZE 16384 76 #define DEFAULT_CA_FILE "/etc/ssl/cert.pem" 77 78 #define TLS_ALL (1 << 1) 79 #define TLS_NOVERIFY (1 << 2) 80 #define TLS_NONAME (1 << 3) 81 #define TLS_CCERT (1 << 4) 82 #define TLS_MUSTSTAPLE (1 << 5) 83 84 /* Command Line Options */ 85 int dflag; /* detached, no stdin */ 86 int Fflag; /* fdpass sock to stdout */ 87 unsigned int iflag; /* Interval Flag */ 88 int kflag; /* More than one connect */ 89 int lflag; /* Bind to local port */ 90 int Nflag; /* shutdown() network socket */ 91 int nflag; /* Don't do name look up */ 92 char *Pflag; /* Proxy username */ 93 char *pflag; /* Localport flag */ 94 int rflag; /* Random ports flag */ 95 char *sflag; /* Source Address */ 96 int tflag; /* Telnet Emulation */ 97 int uflag; /* UDP - Default to TCP */ 98 int vflag; /* Verbosity */ 99 int xflag; /* Socks proxy */ 100 int zflag; /* Port Scan Flag */ 101 int Dflag; /* sodebug */ 102 int Iflag; /* TCP receive buffer size */ 103 int Oflag; /* TCP send buffer size */ 104 int Sflag; /* TCP MD5 signature option */ 105 int Tflag = -1; /* IP Type of Service */ 106 107 int usetls; /* use TLS */ 108 char *Cflag; /* Public cert file */ 109 char *Kflag; /* Private key file */ 110 char *oflag; /* OCSP stapling file */ 111 char *Rflag = DEFAULT_CA_FILE; /* Root CA file */ 112 int tls_cachanged; /* Using non-default CA file */ 113 int TLSopt; /* TLS options */ 114 char *tls_expectname; /* required name in peer cert */ 115 char *tls_expecthash; /* required hash of peer cert */ 116 FILE *Zflag; /* file to save peer cert */ 117 118 int timeout = -1; 119 int family = AF_UNSPEC; 120 char *portlist[PORT_MAX+1]; 121 char *unix_dg_tmp_socket; 122 int ttl = -1; 123 int minttl = -1; 124 125 void atelnet(int, unsigned char *, unsigned int); 126 void build_ports(char *); 127 void help(void); 128 int local_listen(char *, char *, struct addrinfo); 129 void readwrite(int, struct tls *); 130 void fdpass(int nfd) __attribute__((noreturn)); 131 int remote_connect(const char *, const char *, struct addrinfo); 132 int timeout_tls(int, struct tls *, int (*)(struct tls *)); 133 int timeout_connect(int, const struct sockaddr *, socklen_t); 134 int socks_connect(const char *, const char *, struct addrinfo, 135 const char *, const char *, struct addrinfo, int, const char *); 136 int udptest(int); 137 int unix_bind(char *, int); 138 int unix_connect(char *); 139 int unix_listen(char *); 140 void set_common_sockopts(int, int); 141 int map_tos(char *, int *); 142 int map_tls(char *, int *); 143 void save_peer_cert(struct tls *_tls_ctx, FILE *_fp); 144 void report_connect(const struct sockaddr *, socklen_t, char *); 145 void report_tls(struct tls *tls_ctx, char * host, char *tls_expectname); 146 void usage(int); 147 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 148 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 149 void tls_setup_client(struct tls *, int, char *); 150 struct tls *tls_setup_server(struct tls *, int, char *); 151 152 int 153 main(int argc, char *argv[]) 154 { 155 int ch, s = -1, ret, socksv; 156 char *host, *uport; 157 struct addrinfo hints; 158 struct servent *sv; 159 socklen_t len; 160 struct sockaddr_storage cliaddr; 161 char *proxy, *proxyport = NULL; 162 const char *errstr; 163 struct addrinfo proxyhints; 164 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 165 struct tls_config *tls_cfg = NULL; 166 struct tls *tls_ctx = NULL; 167 168 ret = 1; 169 socksv = 5; 170 host = NULL; 171 uport = NULL; 172 sv = NULL; 173 174 signal(SIGPIPE, SIG_IGN); 175 176 while ((ch = getopt(argc, argv, 177 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vw:X:x:Z:z")) != -1) { 178 switch (ch) { 179 case '4': 180 family = AF_INET; 181 break; 182 case '6': 183 family = AF_INET6; 184 break; 185 case 'U': 186 family = AF_UNIX; 187 break; 188 case 'X': 189 if (strcasecmp(optarg, "connect") == 0) 190 socksv = -1; /* HTTP proxy CONNECT */ 191 else if (strcmp(optarg, "4") == 0) 192 socksv = 4; /* SOCKS v.4 */ 193 else if (strcmp(optarg, "5") == 0) 194 socksv = 5; /* SOCKS v.5 */ 195 else 196 errx(1, "unsupported proxy protocol"); 197 break; 198 case 'C': 199 Cflag = optarg; 200 break; 201 case 'c': 202 usetls = 1; 203 break; 204 case 'd': 205 dflag = 1; 206 break; 207 case 'e': 208 tls_expectname = optarg; 209 break; 210 case 'F': 211 Fflag = 1; 212 break; 213 case 'H': 214 tls_expecthash = optarg; 215 break; 216 case 'h': 217 help(); 218 break; 219 case 'i': 220 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 221 if (errstr) 222 errx(1, "interval %s: %s", errstr, optarg); 223 break; 224 case 'K': 225 Kflag = optarg; 226 break; 227 case 'k': 228 kflag = 1; 229 break; 230 case 'l': 231 lflag = 1; 232 break; 233 case 'M': 234 ttl = strtonum(optarg, 0, 255, &errstr); 235 if (errstr) 236 errx(1, "ttl is %s", errstr); 237 break; 238 case 'm': 239 minttl = strtonum(optarg, 0, 255, &errstr); 240 if (errstr) 241 errx(1, "minttl is %s", errstr); 242 break; 243 case 'N': 244 Nflag = 1; 245 break; 246 case 'n': 247 nflag = 1; 248 break; 249 case 'P': 250 Pflag = optarg; 251 break; 252 case 'p': 253 pflag = optarg; 254 break; 255 case 'R': 256 tls_cachanged = 1; 257 Rflag = optarg; 258 break; 259 case 'r': 260 rflag = 1; 261 break; 262 case 's': 263 sflag = optarg; 264 break; 265 case 't': 266 tflag = 1; 267 break; 268 case 'u': 269 uflag = 1; 270 break; 271 case 'V': 272 errx(1, "unsupported option"); 273 break; 274 case 'v': 275 vflag = 1; 276 break; 277 case 'w': 278 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 279 if (errstr) 280 errx(1, "timeout %s: %s", errstr, optarg); 281 timeout *= 1000; 282 break; 283 case 'x': 284 xflag = 1; 285 if ((proxy = strdup(optarg)) == NULL) 286 err(1, NULL); 287 break; 288 case 'Z': 289 #if 0 290 if (strcmp(optarg, "-") == 0) 291 Zflag = stderr; 292 else if ((Zflag = fopen(optarg, "w")) == NULL) 293 err(1, "can't open %s", optarg); 294 #else 295 errx(1, "unsupported option"); 296 #endif 297 break; 298 case 'z': 299 zflag = 1; 300 break; 301 case 'D': 302 Dflag = 1; 303 break; 304 case 'I': 305 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 306 if (errstr != NULL) 307 errx(1, "TCP receive window %s: %s", 308 errstr, optarg); 309 break; 310 case 'O': 311 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 312 if (errstr != NULL) 313 errx(1, "TCP send window %s: %s", 314 errstr, optarg); 315 break; 316 case 'o': 317 oflag = optarg; 318 break; 319 case 'S': 320 Sflag = 1; 321 break; 322 case 'T': 323 errstr = NULL; 324 errno = 0; 325 if (map_tos(optarg, &Tflag)) 326 break; 327 if (map_tls(optarg, &TLSopt)) 328 break; 329 if (strlen(optarg) > 1 && optarg[0] == '0' && 330 optarg[1] == 'x') 331 Tflag = (int)strtol(optarg, NULL, 16); 332 else 333 Tflag = (int)strtonum(optarg, 0, 255, 334 &errstr); 335 if (Tflag < 0 || Tflag > 255 || errstr || errno) 336 errx(1, "illegal tos/tls value %s", optarg); 337 break; 338 default: 339 usage(1); 340 } 341 } 342 argc -= optind; 343 argv += optind; 344 345 if (family == AF_UNIX) { 346 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 347 err(1, "pledge"); 348 } else if (Fflag) { 349 if (Pflag) { 350 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 351 err(1, "pledge"); 352 } else if (pledge("stdio inet dns sendfd", NULL) == -1) 353 err(1, "pledge"); 354 } else if (Pflag) { 355 if (pledge("stdio inet dns tty", NULL) == -1) 356 err(1, "pledge"); 357 } else if (usetls) { 358 if (pledge("stdio rpath inet dns", NULL) == -1) 359 err(1, "pledge"); 360 } else if (pledge("stdio inet dns", NULL) == -1) 361 err(1, "pledge"); 362 363 /* Cruft to make sure options are clean, and used properly. */ 364 if (argv[0] && !argv[1] && family == AF_UNIX) { 365 host = argv[0]; 366 uport = NULL; 367 } else if (argv[0] && !argv[1]) { 368 if (!lflag) 369 usage(1); 370 uport = argv[0]; 371 host = NULL; 372 } else if (argv[0] && argv[1]) { 373 host = argv[0]; 374 uport = argv[1]; 375 } else 376 usage(1); 377 378 if (lflag && sflag) 379 errx(1, "cannot use -s and -l"); 380 if (lflag && pflag) 381 errx(1, "cannot use -p and -l"); 382 if (lflag && zflag) 383 errx(1, "cannot use -z and -l"); 384 if (!lflag && kflag) 385 errx(1, "must use -l with -k"); 386 if (uflag && usetls) 387 errx(1, "cannot use -c and -u"); 388 if ((family == AF_UNIX) && usetls) 389 errx(1, "cannot use -c and -U"); 390 if ((family == AF_UNIX) && Fflag) 391 errx(1, "cannot use -F and -U"); 392 if (Fflag && usetls) 393 errx(1, "cannot use -c and -F"); 394 if (TLSopt && !usetls) 395 errx(1, "you must specify -c to use TLS options"); 396 if (Cflag && !usetls) 397 errx(1, "you must specify -c to use -C"); 398 if (Kflag && !usetls) 399 errx(1, "you must specify -c to use -K"); 400 if (Zflag && !usetls) 401 errx(1, "you must specify -c to use -Z"); 402 if (oflag && !Cflag) 403 errx(1, "you must specify -C to use -o"); 404 if (tls_cachanged && !usetls) 405 errx(1, "you must specify -c to use -R"); 406 if (tls_expecthash && !usetls) 407 errx(1, "you must specify -c to use -H"); 408 if (tls_expectname && !usetls) 409 errx(1, "you must specify -c to use -e"); 410 411 /* Get name of temporary socket for unix datagram client */ 412 if ((family == AF_UNIX) && uflag && !lflag) { 413 if (sflag) { 414 unix_dg_tmp_socket = sflag; 415 } else { 416 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 417 UNIX_DG_TMP_SOCKET_SIZE); 418 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 419 err(1, "mktemp"); 420 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 421 } 422 } 423 424 /* Initialize addrinfo structure. */ 425 if (family != AF_UNIX) { 426 memset(&hints, 0, sizeof(struct addrinfo)); 427 hints.ai_family = family; 428 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 429 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 430 if (nflag) 431 hints.ai_flags |= AI_NUMERICHOST; 432 } 433 434 if (xflag) { 435 if (uflag) 436 errx(1, "no proxy support for UDP mode"); 437 438 if (lflag) 439 errx(1, "no proxy support for listen"); 440 441 if (family == AF_UNIX) 442 errx(1, "no proxy support for unix sockets"); 443 444 if (sflag) 445 errx(1, "no proxy support for local source address"); 446 447 if (*proxy == '[') { 448 ++proxy; 449 proxyport = strchr(proxy, ']'); 450 if (proxyport == NULL) 451 errx(1, "missing closing bracket in proxy"); 452 *proxyport++ = '\0'; 453 if (*proxyport == '\0') 454 /* Use default proxy port. */ 455 proxyport = NULL; 456 else { 457 if (*proxyport == ':') 458 ++proxyport; 459 else 460 errx(1, "garbage proxy port delimiter"); 461 } 462 } else { 463 proxyport = strrchr(proxy, ':'); 464 if (proxyport != NULL) 465 *proxyport++ = '\0'; 466 } 467 468 memset(&proxyhints, 0, sizeof(struct addrinfo)); 469 proxyhints.ai_family = family; 470 proxyhints.ai_socktype = SOCK_STREAM; 471 proxyhints.ai_protocol = IPPROTO_TCP; 472 if (nflag) 473 proxyhints.ai_flags |= AI_NUMERICHOST; 474 } 475 476 if (usetls) { 477 if (Pflag) { 478 if (pledge("stdio inet dns tty rpath", NULL) == -1) 479 err(1, "pledge"); 480 } else if (pledge("stdio inet dns rpath", NULL) == -1) 481 err(1, "pledge"); 482 483 if (tls_init() == -1) 484 errx(1, "unable to initialize TLS"); 485 if ((tls_cfg = tls_config_new()) == NULL) 486 errx(1, "unable to allocate TLS config"); 487 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 488 errx(1, "%s", tls_config_error(tls_cfg)); 489 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 490 errx(1, "%s", tls_config_error(tls_cfg)); 491 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 492 errx(1, "%s", tls_config_error(tls_cfg)); 493 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 494 errx(1, "%s", tls_config_error(tls_cfg)); 495 if (TLSopt & TLS_ALL) { 496 if (tls_config_set_protocols(tls_cfg, 497 TLS_PROTOCOLS_ALL) != 0) 498 errx(1, "%s", tls_config_error(tls_cfg)); 499 if (tls_config_set_ciphers(tls_cfg, "all") != 0) 500 errx(1, "%s", tls_config_error(tls_cfg)); 501 } 502 if (!lflag && (TLSopt & TLS_CCERT)) 503 errx(1, "clientcert is only valid with -l"); 504 if (TLSopt & TLS_NONAME) 505 tls_config_insecure_noverifyname(tls_cfg); 506 if (TLSopt & TLS_NOVERIFY) { 507 if (tls_expecthash != NULL) 508 errx(1, "-H and -T noverify may not be used" 509 "together"); 510 tls_config_insecure_noverifycert(tls_cfg); 511 } 512 if (TLSopt & TLS_MUSTSTAPLE) 513 tls_config_ocsp_require_stapling(tls_cfg); 514 515 if (Pflag) { 516 if (pledge("stdio inet dns tty", NULL) == -1) 517 err(1, "pledge"); 518 } else if (pledge("stdio inet dns", NULL) == -1) 519 err(1, "pledge"); 520 } 521 if (lflag) { 522 struct tls *tls_cctx = NULL; 523 int connfd; 524 ret = 0; 525 526 if (family == AF_UNIX) { 527 if (uflag) 528 s = unix_bind(host, 0); 529 else 530 s = unix_listen(host); 531 } 532 533 if (usetls) { 534 tls_config_verify_client_optional(tls_cfg); 535 if ((tls_ctx = tls_server()) == NULL) 536 errx(1, "tls server creation failed"); 537 if (tls_configure(tls_ctx, tls_cfg) == -1) 538 errx(1, "tls configuration failed (%s)", 539 tls_error(tls_ctx)); 540 } 541 /* Allow only one connection at a time, but stay alive. */ 542 for (;;) { 543 if (family != AF_UNIX) 544 s = local_listen(host, uport, hints); 545 if (s < 0) 546 err(1, NULL); 547 if (uflag && kflag) { 548 /* 549 * For UDP and -k, don't connect the socket, 550 * let it receive datagrams from multiple 551 * socket pairs. 552 */ 553 readwrite(s, NULL); 554 } else if (uflag && !kflag) { 555 /* 556 * For UDP and not -k, we will use recvfrom() 557 * initially to wait for a caller, then use 558 * the regular functions to talk to the caller. 559 */ 560 int rv, plen; 561 char buf[16384]; 562 struct sockaddr_storage z; 563 564 len = sizeof(z); 565 plen = 2048; 566 rv = recvfrom(s, buf, plen, MSG_PEEK, 567 (struct sockaddr *)&z, &len); 568 if (rv < 0) 569 err(1, "recvfrom"); 570 571 rv = connect(s, (struct sockaddr *)&z, len); 572 if (rv < 0) 573 err(1, "connect"); 574 575 if (vflag) 576 report_connect((struct sockaddr *)&z, len, NULL); 577 578 readwrite(s, NULL); 579 } else { 580 len = sizeof(cliaddr); 581 connfd = accept4(s, (struct sockaddr *)&cliaddr, 582 &len, SOCK_NONBLOCK); 583 if (connfd == -1) { 584 /* For now, all errnos are fatal */ 585 err(1, "accept"); 586 } 587 if (vflag) 588 report_connect((struct sockaddr *)&cliaddr, len, 589 family == AF_UNIX ? host : NULL); 590 if ((usetls) && 591 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 592 readwrite(connfd, tls_cctx); 593 if (!usetls) 594 readwrite(connfd, NULL); 595 if (tls_cctx) { 596 timeout_tls(s, tls_cctx, tls_close); 597 tls_free(tls_cctx); 598 tls_cctx = NULL; 599 } 600 close(connfd); 601 } 602 if (family != AF_UNIX) 603 close(s); 604 else if (uflag) { 605 if (connect(s, NULL, 0) < 0) 606 err(1, "connect"); 607 } 608 609 if (!kflag) 610 break; 611 } 612 } else if (family == AF_UNIX) { 613 ret = 0; 614 615 if ((s = unix_connect(host)) > 0) { 616 if (!zflag) 617 readwrite(s, NULL); 618 close(s); 619 } else 620 ret = 1; 621 622 if (uflag) 623 unlink(unix_dg_tmp_socket); 624 exit(ret); 625 626 } else { 627 int i = 0; 628 629 /* Construct the portlist[] array. */ 630 build_ports(uport); 631 632 /* Cycle through portlist, connecting to each port. */ 633 for (s = -1, i = 0; portlist[i] != NULL; i++) { 634 if (s != -1) 635 close(s); 636 637 if (usetls) { 638 if ((tls_ctx = tls_client()) == NULL) 639 errx(1, "tls client creation failed"); 640 if (tls_configure(tls_ctx, tls_cfg) == -1) 641 errx(1, "tls configuration failed (%s)", 642 tls_error(tls_ctx)); 643 } 644 if (xflag) 645 s = socks_connect(host, portlist[i], hints, 646 proxy, proxyport, proxyhints, socksv, 647 Pflag); 648 else 649 s = remote_connect(host, portlist[i], hints); 650 651 if (s == -1) 652 continue; 653 654 ret = 0; 655 if (vflag || zflag) { 656 /* For UDP, make sure we are connected. */ 657 if (uflag) { 658 if (udptest(s) == -1) { 659 ret = 1; 660 continue; 661 } 662 } 663 664 /* Don't look up port if -n. */ 665 if (nflag) 666 sv = NULL; 667 else { 668 sv = getservbyport( 669 ntohs(atoi(portlist[i])), 670 uflag ? "udp" : "tcp"); 671 } 672 673 fprintf(stderr, 674 "Connection to %s %s port [%s/%s] " 675 "succeeded!\n", host, portlist[i], 676 uflag ? "udp" : "tcp", 677 sv ? sv->s_name : "*"); 678 } 679 if (Fflag) 680 fdpass(s); 681 else { 682 if (usetls) 683 tls_setup_client(tls_ctx, s, host); 684 if (!zflag) 685 readwrite(s, tls_ctx); 686 if (tls_ctx) { 687 timeout_tls(s, tls_ctx, tls_close); 688 tls_free(tls_ctx); 689 tls_ctx = NULL; 690 } 691 } 692 } 693 } 694 695 if (s != -1) 696 close(s); 697 698 tls_config_free(tls_cfg); 699 700 exit(ret); 701 } 702 703 /* 704 * unix_bind() 705 * Returns a unix socket bound to the given path 706 */ 707 int 708 unix_bind(char *path, int flags) 709 { 710 struct sockaddr_un s_un; 711 int s, save_errno; 712 713 /* Create unix domain socket. */ 714 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 715 0)) < 0) 716 return (-1); 717 718 memset(&s_un, 0, sizeof(struct sockaddr_un)); 719 s_un.sun_family = AF_UNIX; 720 721 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 722 sizeof(s_un.sun_path)) { 723 close(s); 724 errno = ENAMETOOLONG; 725 return (-1); 726 } 727 728 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 729 save_errno = errno; 730 close(s); 731 errno = save_errno; 732 return (-1); 733 } 734 return (s); 735 } 736 737 int 738 timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) 739 { 740 struct pollfd pfd; 741 int ret; 742 743 while ((ret = (*func)(tls_ctx)) != 0) { 744 if (ret == TLS_WANT_POLLIN) 745 pfd.events = POLLIN; 746 else if (ret == TLS_WANT_POLLOUT) 747 pfd.events = POLLOUT; 748 else 749 break; 750 pfd.fd = s; 751 if ((ret = poll(&pfd, 1, timeout)) == 1) 752 continue; 753 else if (ret == 0) { 754 errno = ETIMEDOUT; 755 ret = -1; 756 break; 757 } else 758 err(1, "poll failed"); 759 } 760 761 return (ret); 762 } 763 764 void 765 tls_setup_client(struct tls *tls_ctx, int s, char *host) 766 { 767 const char *errstr; 768 769 if (tls_connect_socket(tls_ctx, s, 770 tls_expectname ? tls_expectname : host) == -1) { 771 errx(1, "tls connection failed (%s)", 772 tls_error(tls_ctx)); 773 } 774 if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { 775 if ((errstr = tls_error(tls_ctx)) == NULL) 776 errstr = strerror(errno); 777 errx(1, "tls handshake failed (%s)", errstr); 778 } 779 if (vflag) 780 report_tls(tls_ctx, host, tls_expectname); 781 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 782 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 783 errx(1, "peer certificate is not %s", tls_expecthash); 784 if (Zflag) { 785 save_peer_cert(tls_ctx, Zflag); 786 if (Zflag != stderr && (fclose(Zflag) != 0)) 787 err(1, "fclose failed saving peer cert"); 788 } 789 } 790 791 struct tls * 792 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 793 { 794 struct tls *tls_cctx; 795 const char *errstr; 796 797 if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { 798 warnx("tls accept failed (%s)", tls_error(tls_ctx)); 799 } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { 800 if ((errstr = tls_error(tls_cctx)) == NULL) 801 errstr = strerror(errno); 802 warnx("tls handshake failed (%s)", errstr); 803 } else { 804 int gotcert = tls_peer_cert_provided(tls_cctx); 805 806 if (vflag && gotcert) 807 report_tls(tls_cctx, host, tls_expectname); 808 if ((TLSopt & TLS_CCERT) && !gotcert) 809 warnx("No client certificate provided"); 810 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 811 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 812 warnx("peer certificate is not %s", tls_expecthash); 813 else if (gotcert && tls_expectname && 814 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 815 warnx("name (%s) not found in client cert", 816 tls_expectname); 817 else { 818 return tls_cctx; 819 } 820 } 821 return NULL; 822 } 823 824 /* 825 * unix_connect() 826 * Returns a socket connected to a local unix socket. Returns -1 on failure. 827 */ 828 int 829 unix_connect(char *path) 830 { 831 struct sockaddr_un s_un; 832 int s, save_errno; 833 834 if (uflag) { 835 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 836 return (-1); 837 } else { 838 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 839 return (-1); 840 } 841 842 memset(&s_un, 0, sizeof(struct sockaddr_un)); 843 s_un.sun_family = AF_UNIX; 844 845 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 846 sizeof(s_un.sun_path)) { 847 close(s); 848 errno = ENAMETOOLONG; 849 return (-1); 850 } 851 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 852 save_errno = errno; 853 close(s); 854 errno = save_errno; 855 return (-1); 856 } 857 return (s); 858 859 } 860 861 /* 862 * unix_listen() 863 * Create a unix domain socket, and listen on it. 864 */ 865 int 866 unix_listen(char *path) 867 { 868 int s; 869 if ((s = unix_bind(path, 0)) < 0) 870 return (-1); 871 872 if (listen(s, 5) < 0) { 873 close(s); 874 return (-1); 875 } 876 return (s); 877 } 878 879 /* 880 * remote_connect() 881 * Returns a socket connected to a remote host. Properly binds to a local 882 * port or source address if needed. Returns -1 on failure. 883 */ 884 int 885 remote_connect(const char *host, const char *port, struct addrinfo hints) 886 { 887 struct addrinfo *res, *res0; 888 int s = -1, error, on = 1, save_errno; 889 890 if ((error = getaddrinfo(host, port, &hints, &res0))) 891 errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, 892 port, gai_strerror(error)); 893 894 for (res = res0; res; res = res->ai_next) { 895 if ((s = socket(res->ai_family, res->ai_socktype | 896 SOCK_NONBLOCK, res->ai_protocol)) < 0) 897 continue; 898 899 /* Bind to a local port or source address if specified. */ 900 if (sflag || pflag) { 901 struct addrinfo ahints, *ares; 902 903 /* try IP_TRANSPARENT, but don't insist */ 904 setsockopt(s, SOL_IP, IP_TRANSPARENT, &on, sizeof(on)); 905 memset(&ahints, 0, sizeof(struct addrinfo)); 906 ahints.ai_family = res->ai_family; 907 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 908 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 909 ahints.ai_flags = AI_PASSIVE; 910 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 911 errx(1, "getaddrinfo: %s", gai_strerror(error)); 912 913 if (bind(s, (struct sockaddr *)ares->ai_addr, 914 ares->ai_addrlen) < 0) 915 err(1, "bind failed"); 916 freeaddrinfo(ares); 917 } 918 919 set_common_sockopts(s, res->ai_family); 920 921 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 922 break; 923 if (vflag) 924 warn("connect to %s port %s (%s) failed", host, port, 925 uflag ? "udp" : "tcp"); 926 927 save_errno = errno; 928 close(s); 929 errno = save_errno; 930 s = -1; 931 } 932 933 freeaddrinfo(res0); 934 935 return (s); 936 } 937 938 int 939 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 940 { 941 struct pollfd pfd; 942 socklen_t optlen; 943 int optval; 944 int ret; 945 946 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 947 pfd.fd = s; 948 pfd.events = POLLOUT; 949 if ((ret = poll(&pfd, 1, timeout)) == 1) { 950 optlen = sizeof(optval); 951 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 952 &optval, &optlen)) == 0) { 953 errno = optval; 954 ret = optval == 0 ? 0 : -1; 955 } 956 } else if (ret == 0) { 957 errno = ETIMEDOUT; 958 ret = -1; 959 } else 960 err(1, "poll failed"); 961 } 962 963 return (ret); 964 } 965 966 /* 967 * local_listen() 968 * Returns a socket listening on a local port, binds to specified source 969 * address. Returns -1 on failure. 970 */ 971 int 972 local_listen(char *host, char *port, struct addrinfo hints) 973 { 974 struct addrinfo *res, *res0; 975 int s = -1, ret, x = 1, save_errno; 976 int error; 977 978 /* Allow nodename to be null. */ 979 hints.ai_flags |= AI_PASSIVE; 980 981 /* 982 * In the case of binding to a wildcard address 983 * default to binding to an ipv4 address. 984 */ 985 if (host == NULL && hints.ai_family == AF_UNSPEC) 986 hints.ai_family = AF_INET; 987 988 if ((error = getaddrinfo(host, port, &hints, &res0))) 989 errx(1, "getaddrinfo: %s", gai_strerror(error)); 990 991 for (res = res0; res; res = res->ai_next) { 992 if ((s = socket(res->ai_family, res->ai_socktype, 993 res->ai_protocol)) < 0) 994 continue; 995 996 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 997 if (ret == -1) 998 err(1, NULL); 999 1000 set_common_sockopts(s, res->ai_family); 1001 1002 if (bind(s, (struct sockaddr *)res->ai_addr, 1003 res->ai_addrlen) == 0) 1004 break; 1005 1006 save_errno = errno; 1007 close(s); 1008 errno = save_errno; 1009 s = -1; 1010 } 1011 1012 if (!uflag && s != -1) { 1013 if (listen(s, 1) < 0) 1014 err(1, "listen"); 1015 } 1016 1017 freeaddrinfo(res0); 1018 1019 return (s); 1020 } 1021 1022 /* 1023 * readwrite() 1024 * Loop that polls on the network file descriptor and stdin. 1025 */ 1026 void 1027 readwrite(int net_fd, struct tls *tls_ctx) 1028 { 1029 struct pollfd pfd[4]; 1030 int stdin_fd = STDIN_FILENO; 1031 int stdout_fd = STDOUT_FILENO; 1032 unsigned char netinbuf[BUFSIZE]; 1033 size_t netinbufpos = 0; 1034 unsigned char stdinbuf[BUFSIZE]; 1035 size_t stdinbufpos = 0; 1036 int n, num_fds; 1037 ssize_t ret; 1038 1039 /* don't read from stdin if requested */ 1040 if (dflag) 1041 stdin_fd = -1; 1042 1043 /* stdin */ 1044 pfd[POLL_STDIN].fd = stdin_fd; 1045 pfd[POLL_STDIN].events = POLLIN; 1046 1047 /* network out */ 1048 pfd[POLL_NETOUT].fd = net_fd; 1049 pfd[POLL_NETOUT].events = 0; 1050 1051 /* network in */ 1052 pfd[POLL_NETIN].fd = net_fd; 1053 pfd[POLL_NETIN].events = POLLIN; 1054 1055 /* stdout */ 1056 pfd[POLL_STDOUT].fd = stdout_fd; 1057 pfd[POLL_STDOUT].events = 0; 1058 1059 while (1) { 1060 /* both inputs are gone, buffers are empty, we are done */ 1061 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1062 stdinbufpos == 0 && netinbufpos == 0) 1063 return; 1064 /* both outputs are gone, we can't continue */ 1065 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) 1066 return; 1067 /* listen and net in gone, queues empty, done */ 1068 if (lflag && pfd[POLL_NETIN].fd == -1 && 1069 stdinbufpos == 0 && netinbufpos == 0) 1070 return; 1071 1072 /* help says -i is for "wait between lines sent". We read and 1073 * write arbitrary amounts of data, and we don't want to start 1074 * scanning for newlines, so this is as good as it gets */ 1075 if (iflag) 1076 sleep(iflag); 1077 1078 /* poll */ 1079 num_fds = poll(pfd, 4, timeout); 1080 1081 /* treat poll errors */ 1082 if (num_fds == -1) 1083 err(1, "polling error"); 1084 1085 /* timeout happened */ 1086 if (num_fds == 0) 1087 return; 1088 1089 /* treat socket error conditions */ 1090 for (n = 0; n < 4; n++) { 1091 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1092 pfd[n].fd = -1; 1093 } 1094 } 1095 /* reading is possible after HUP */ 1096 if (pfd[POLL_STDIN].events & POLLIN && 1097 pfd[POLL_STDIN].revents & POLLHUP && 1098 !(pfd[POLL_STDIN].revents & POLLIN)) 1099 pfd[POLL_STDIN].fd = -1; 1100 1101 if (pfd[POLL_NETIN].events & POLLIN && 1102 pfd[POLL_NETIN].revents & POLLHUP && 1103 !(pfd[POLL_NETIN].revents & POLLIN)) 1104 pfd[POLL_NETIN].fd = -1; 1105 1106 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1107 if (Nflag) 1108 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1109 pfd[POLL_NETOUT].fd = -1; 1110 } 1111 /* if HUP, stop watching stdout */ 1112 if (pfd[POLL_STDOUT].revents & POLLHUP) 1113 pfd[POLL_STDOUT].fd = -1; 1114 /* if no net out, stop watching stdin */ 1115 if (pfd[POLL_NETOUT].fd == -1) 1116 pfd[POLL_STDIN].fd = -1; 1117 /* if no stdout, stop watching net in */ 1118 if (pfd[POLL_STDOUT].fd == -1) { 1119 if (pfd[POLL_NETIN].fd != -1) 1120 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1121 pfd[POLL_NETIN].fd = -1; 1122 } 1123 1124 /* try to read from stdin */ 1125 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1126 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1127 &stdinbufpos, NULL); 1128 if (ret == TLS_WANT_POLLIN) 1129 pfd[POLL_STDIN].events = POLLIN; 1130 else if (ret == TLS_WANT_POLLOUT) 1131 pfd[POLL_STDIN].events = POLLOUT; 1132 else if (ret == 0 || ret == -1) 1133 pfd[POLL_STDIN].fd = -1; 1134 /* read something - poll net out */ 1135 if (stdinbufpos > 0) 1136 pfd[POLL_NETOUT].events = POLLOUT; 1137 /* filled buffer - remove self from polling */ 1138 if (stdinbufpos == BUFSIZE) 1139 pfd[POLL_STDIN].events = 0; 1140 } 1141 /* try to write to network */ 1142 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1143 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1144 &stdinbufpos, tls_ctx); 1145 if (ret == TLS_WANT_POLLIN) 1146 pfd[POLL_NETOUT].events = POLLIN; 1147 else if (ret == TLS_WANT_POLLOUT) 1148 pfd[POLL_NETOUT].events = POLLOUT; 1149 else if (ret == -1) 1150 pfd[POLL_NETOUT].fd = -1; 1151 /* buffer empty - remove self from polling */ 1152 if (stdinbufpos == 0) 1153 pfd[POLL_NETOUT].events = 0; 1154 /* buffer no longer full - poll stdin again */ 1155 if (stdinbufpos < BUFSIZE) 1156 pfd[POLL_STDIN].events = POLLIN; 1157 } 1158 /* try to read from network */ 1159 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1160 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1161 &netinbufpos, tls_ctx); 1162 if (ret == TLS_WANT_POLLIN) 1163 pfd[POLL_NETIN].events = POLLIN; 1164 else if (ret == TLS_WANT_POLLOUT) 1165 pfd[POLL_NETIN].events = POLLOUT; 1166 else if (ret == -1) 1167 pfd[POLL_NETIN].fd = -1; 1168 /* eof on net in - remove from pfd */ 1169 if (ret == 0) { 1170 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1171 pfd[POLL_NETIN].fd = -1; 1172 } 1173 /* read something - poll stdout */ 1174 if (netinbufpos > 0) 1175 pfd[POLL_STDOUT].events = POLLOUT; 1176 /* filled buffer - remove self from polling */ 1177 if (netinbufpos == BUFSIZE) 1178 pfd[POLL_NETIN].events = 0; 1179 /* handle telnet */ 1180 if (tflag) 1181 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1182 netinbufpos); 1183 } 1184 /* try to write to stdout */ 1185 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1186 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1187 &netinbufpos, NULL); 1188 if (ret == TLS_WANT_POLLIN) 1189 pfd[POLL_STDOUT].events = POLLIN; 1190 else if (ret == TLS_WANT_POLLOUT) 1191 pfd[POLL_STDOUT].events = POLLOUT; 1192 else if (ret == -1) 1193 pfd[POLL_STDOUT].fd = -1; 1194 /* buffer empty - remove self from polling */ 1195 if (netinbufpos == 0) 1196 pfd[POLL_STDOUT].events = 0; 1197 /* buffer no longer full - poll net in again */ 1198 if (netinbufpos < BUFSIZE) 1199 pfd[POLL_NETIN].events = POLLIN; 1200 } 1201 1202 /* stdin gone and queue empty? */ 1203 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1204 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1205 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1206 pfd[POLL_NETOUT].fd = -1; 1207 } 1208 /* net in gone and queue empty? */ 1209 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1210 pfd[POLL_STDOUT].fd = -1; 1211 } 1212 } 1213 } 1214 1215 ssize_t 1216 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1217 { 1218 ssize_t n; 1219 ssize_t adjust; 1220 1221 if (tls) 1222 n = tls_write(tls, buf, *bufpos); 1223 else { 1224 n = write(fd, buf, *bufpos); 1225 /* don't treat EAGAIN, EINTR as error */ 1226 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1227 n = TLS_WANT_POLLOUT; 1228 } 1229 if (n <= 0) 1230 return n; 1231 /* adjust buffer */ 1232 adjust = *bufpos - n; 1233 if (adjust > 0) 1234 memmove(buf, buf + n, adjust); 1235 *bufpos -= n; 1236 return n; 1237 } 1238 1239 ssize_t 1240 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1241 { 1242 size_t num = BUFSIZE - *bufpos; 1243 ssize_t n; 1244 1245 if (tls) 1246 n = tls_read(tls, buf + *bufpos, num); 1247 else { 1248 n = read(fd, buf + *bufpos, num); 1249 /* don't treat EAGAIN, EINTR as error */ 1250 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1251 n = TLS_WANT_POLLIN; 1252 } 1253 if (n <= 0) 1254 return n; 1255 *bufpos += n; 1256 return n; 1257 } 1258 1259 /* 1260 * fdpass() 1261 * Pass the connected file descriptor to stdout and exit. 1262 */ 1263 void 1264 fdpass(int nfd) 1265 { 1266 struct msghdr mh; 1267 union { 1268 struct cmsghdr hdr; 1269 char buf[CMSG_SPACE(sizeof(int))]; 1270 } cmsgbuf; 1271 struct cmsghdr *cmsg; 1272 struct iovec iov; 1273 char c = '\0'; 1274 ssize_t r; 1275 struct pollfd pfd; 1276 1277 /* Avoid obvious stupidity */ 1278 if (isatty(STDOUT_FILENO)) 1279 errx(1, "Cannot pass file descriptor to tty"); 1280 1281 bzero(&mh, sizeof(mh)); 1282 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1283 bzero(&iov, sizeof(iov)); 1284 1285 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1286 mh.msg_controllen = sizeof(cmsgbuf.buf); 1287 cmsg = CMSG_FIRSTHDR(&mh); 1288 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1289 cmsg->cmsg_level = SOL_SOCKET; 1290 cmsg->cmsg_type = SCM_RIGHTS; 1291 *(int *)CMSG_DATA(cmsg) = nfd; 1292 1293 iov.iov_base = &c; 1294 iov.iov_len = 1; 1295 mh.msg_iov = &iov; 1296 mh.msg_iovlen = 1; 1297 1298 bzero(&pfd, sizeof(pfd)); 1299 pfd.fd = STDOUT_FILENO; 1300 pfd.events = POLLOUT; 1301 for (;;) { 1302 r = sendmsg(STDOUT_FILENO, &mh, 0); 1303 if (r == -1) { 1304 if (errno == EAGAIN || errno == EINTR) { 1305 if (poll(&pfd, 1, -1) == -1) 1306 err(1, "poll"); 1307 continue; 1308 } 1309 err(1, "sendmsg"); 1310 } else if (r != 1) 1311 errx(1, "sendmsg: unexpected return value %zd", r); 1312 else 1313 break; 1314 } 1315 exit(0); 1316 } 1317 1318 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1319 void 1320 atelnet(int nfd, unsigned char *buf, unsigned int size) 1321 { 1322 unsigned char *p, *end; 1323 unsigned char obuf[4]; 1324 1325 if (size < 3) 1326 return; 1327 end = buf + size - 2; 1328 1329 for (p = buf; p < end; p++) { 1330 if (*p != IAC) 1331 continue; 1332 1333 obuf[0] = IAC; 1334 p++; 1335 if ((*p == WILL) || (*p == WONT)) 1336 obuf[1] = DONT; 1337 else if ((*p == DO) || (*p == DONT)) 1338 obuf[1] = WONT; 1339 else 1340 continue; 1341 1342 p++; 1343 obuf[2] = *p; 1344 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1345 warn("Write Error!"); 1346 } 1347 } 1348 1349 1350 int 1351 strtoport(char *portstr, int udp) 1352 { 1353 struct servent *entry; 1354 const char *errstr; 1355 char *proto; 1356 int port = -1; 1357 1358 proto = udp ? "udp" : "tcp"; 1359 1360 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1361 if (errstr == NULL) 1362 return port; 1363 if (errno != EINVAL) 1364 errx(1, "port number %s: %s", errstr, portstr); 1365 if ((entry = getservbyname(portstr, proto)) == NULL) 1366 errx(1, "service \"%s\" unknown", portstr); 1367 return ntohs(entry->s_port); 1368 } 1369 1370 /* 1371 * build_ports() 1372 * Build an array of ports in portlist[], listing each port 1373 * that we should try to connect to. 1374 */ 1375 void 1376 build_ports(char *p) 1377 { 1378 char *n; 1379 int hi, lo, cp; 1380 int x = 0; 1381 1382 if ((n = strchr(p, '-')) != NULL) { 1383 *n = '\0'; 1384 n++; 1385 1386 /* Make sure the ports are in order: lowest->highest. */ 1387 hi = strtoport(n, uflag); 1388 lo = strtoport(p, uflag); 1389 if (lo > hi) { 1390 cp = hi; 1391 hi = lo; 1392 lo = cp; 1393 } 1394 1395 /* 1396 * Initialize portlist with a random permutation. Based on 1397 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1398 */ 1399 if (rflag) { 1400 for (x = 0; x <= hi - lo; x++) { 1401 cp = arc4random_uniform(x + 1); 1402 portlist[x] = portlist[cp]; 1403 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1404 err(1, "asprintf"); 1405 } 1406 } else { /* Load ports sequentially. */ 1407 for (cp = lo; cp <= hi; cp++) { 1408 if (asprintf(&portlist[x], "%d", cp) < 0) 1409 err(1, "asprintf"); 1410 x++; 1411 } 1412 } 1413 } else { 1414 char *tmp; 1415 1416 hi = strtoport(p, uflag); 1417 if (asprintf(&tmp, "%d", hi) != -1) 1418 portlist[0] = tmp; 1419 else 1420 err(1, NULL); 1421 } 1422 } 1423 1424 /* 1425 * udptest() 1426 * Do a few writes to see if the UDP port is there. 1427 * Fails once PF state table is full. 1428 */ 1429 int 1430 udptest(int s) 1431 { 1432 int i, ret; 1433 1434 for (i = 0; i <= 3; i++) { 1435 if (write(s, "X", 1) == 1) 1436 ret = 1; 1437 else 1438 ret = -1; 1439 } 1440 return (ret); 1441 } 1442 1443 void 1444 set_common_sockopts(int s, int af) 1445 { 1446 int x = 1; 1447 1448 if (Sflag) { 1449 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1450 &x, sizeof(x)) == -1) 1451 err(1, NULL); 1452 } 1453 if (Dflag) { 1454 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1455 &x, sizeof(x)) == -1) 1456 err(1, NULL); 1457 } 1458 if (Tflag != -1) { 1459 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1460 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1461 err(1, "set IP ToS"); 1462 1463 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1464 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1465 err(1, "set IPv6 traffic class"); 1466 } 1467 if (Iflag) { 1468 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1469 &Iflag, sizeof(Iflag)) == -1) 1470 err(1, "set TCP receive buffer size"); 1471 } 1472 if (Oflag) { 1473 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1474 &Oflag, sizeof(Oflag)) == -1) 1475 err(1, "set TCP send buffer size"); 1476 } 1477 1478 if (ttl != -1) { 1479 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1480 IP_TTL, &ttl, sizeof(ttl))) 1481 err(1, "set IP TTL"); 1482 1483 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1484 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1485 err(1, "set IPv6 unicast hops"); 1486 } 1487 1488 if (minttl != -1) { 1489 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1490 IP_MINTTL, &minttl, sizeof(minttl))) 1491 err(1, "set IP min TTL"); 1492 1493 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1494 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1495 err(1, "set IPv6 min hop count"); 1496 } 1497 } 1498 1499 int 1500 map_tos(char *s, int *val) 1501 { 1502 #define IPTOS_DSCP_CS0 0x00 1503 #define IPTOS_DSCP_CS1 0x20 1504 #define IPTOS_DSCP_CS2 0x40 1505 #define IPTOS_DSCP_CS3 0x60 1506 #define IPTOS_DSCP_CS4 0x80 1507 #define IPTOS_DSCP_CS5 0xa0 1508 #define IPTOS_DSCP_CS6 0xc0 1509 #define IPTOS_DSCP_CS7 0xe0 1510 /* DiffServ Codepoints and other TOS mappings */ 1511 const struct toskeywords { 1512 const char *keyword; 1513 int val; 1514 } *t, toskeywords[] = { 1515 { "af11", IPTOS_DSCP_AF11 }, 1516 { "af12", IPTOS_DSCP_AF12 }, 1517 { "af13", IPTOS_DSCP_AF13 }, 1518 { "af21", IPTOS_DSCP_AF21 }, 1519 { "af22", IPTOS_DSCP_AF22 }, 1520 { "af23", IPTOS_DSCP_AF23 }, 1521 { "af31", IPTOS_DSCP_AF31 }, 1522 { "af32", IPTOS_DSCP_AF32 }, 1523 { "af33", IPTOS_DSCP_AF33 }, 1524 { "af41", IPTOS_DSCP_AF41 }, 1525 { "af42", IPTOS_DSCP_AF42 }, 1526 { "af43", IPTOS_DSCP_AF43 }, 1527 { "critical", IPTOS_PREC_CRITIC_ECP }, 1528 { "cs0", IPTOS_DSCP_CS0 }, 1529 { "cs1", IPTOS_DSCP_CS1 }, 1530 { "cs2", IPTOS_DSCP_CS2 }, 1531 { "cs3", IPTOS_DSCP_CS3 }, 1532 { "cs4", IPTOS_DSCP_CS4 }, 1533 { "cs5", IPTOS_DSCP_CS5 }, 1534 { "cs6", IPTOS_DSCP_CS6 }, 1535 { "cs7", IPTOS_DSCP_CS7 }, 1536 { "ef", IPTOS_DSCP_EF }, 1537 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1538 { "lowdelay", IPTOS_LOWDELAY }, 1539 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1540 { "reliability", IPTOS_RELIABILITY }, 1541 { "throughput", IPTOS_THROUGHPUT }, 1542 { NULL, -1 }, 1543 }; 1544 1545 for (t = toskeywords; t->keyword != NULL; t++) { 1546 if (strcmp(s, t->keyword) == 0) { 1547 *val = t->val; 1548 return (1); 1549 } 1550 } 1551 1552 return (0); 1553 } 1554 1555 int 1556 map_tls(char *s, int *val) 1557 { 1558 const struct tlskeywords { 1559 const char *keyword; 1560 int val; 1561 } *t, tlskeywords[] = { 1562 { "tlsall", TLS_ALL }, 1563 { "noverify", TLS_NOVERIFY }, 1564 { "noname", TLS_NONAME }, 1565 { "clientcert", TLS_CCERT}, 1566 { "muststaple", TLS_MUSTSTAPLE}, 1567 { NULL, -1 }, 1568 }; 1569 1570 for (t = tlskeywords; t->keyword != NULL; t++) { 1571 if (strcmp(s, t->keyword) == 0) { 1572 *val |= t->val; 1573 return (1); 1574 } 1575 } 1576 return (0); 1577 } 1578 1579 void 1580 save_peer_cert(struct tls *tls_ctx, FILE *fp) 1581 { 1582 /* currently unsupported on Linux */ 1583 #if 0 1584 const char *pem; 1585 size_t plen; 1586 1587 if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL) 1588 errx(1, "Can't get peer certificate"); 1589 if (fprintf(fp, "%.*s", (int)plen, pem) < 0) 1590 err(1, "unable to save peer cert"); 1591 if (fflush(fp) != 0) 1592 err(1, "unable to flush peer cert"); 1593 #endif 1594 } 1595 1596 void 1597 report_tls(struct tls * tls_ctx, char * host, char *tls_expectname) 1598 { 1599 time_t t; 1600 const char *ocsp_url; 1601 1602 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1603 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1604 fprintf(stderr, "Peer name: %s\n", 1605 tls_expectname ? tls_expectname : host); 1606 if (tls_peer_cert_subject(tls_ctx)) 1607 fprintf(stderr, "Subject: %s\n", 1608 tls_peer_cert_subject(tls_ctx)); 1609 if (tls_peer_cert_issuer(tls_ctx)) 1610 fprintf(stderr, "Issuer: %s\n", 1611 tls_peer_cert_issuer(tls_ctx)); 1612 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1613 fprintf(stderr, "Valid From: %s", ctime(&t)); 1614 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1615 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1616 if (tls_peer_cert_hash(tls_ctx)) 1617 fprintf(stderr, "Cert Hash: %s\n", 1618 tls_peer_cert_hash(tls_ctx)); 1619 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1620 if (ocsp_url != NULL) 1621 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1622 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1623 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1624 fprintf(stderr, "OCSP Stapling: %s\n", 1625 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1626 tls_peer_ocsp_result(tls_ctx)); 1627 fprintf(stderr, 1628 " response_status=%d cert_status=%d crl_reason=%d\n", 1629 tls_peer_ocsp_response_status(tls_ctx), 1630 tls_peer_ocsp_cert_status(tls_ctx), 1631 tls_peer_ocsp_crl_reason(tls_ctx)); 1632 t = tls_peer_ocsp_this_update(tls_ctx); 1633 fprintf(stderr, " this update: %s", 1634 t != -1 ? ctime(&t) : "\n"); 1635 t = tls_peer_ocsp_next_update(tls_ctx); 1636 fprintf(stderr, " next update: %s", 1637 t != -1 ? ctime(&t) : "\n"); 1638 t = tls_peer_ocsp_revocation_time(tls_ctx); 1639 fprintf(stderr, " revocation: %s", 1640 t != -1 ? ctime(&t) : "\n"); 1641 break; 1642 case -1: 1643 break; 1644 default: 1645 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1646 tls_peer_ocsp_response_status(tls_ctx), 1647 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1648 tls_peer_ocsp_result(tls_ctx)); 1649 break; 1650 1651 } 1652 } 1653 1654 void 1655 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1656 { 1657 char remote_host[NI_MAXHOST]; 1658 char remote_port[NI_MAXSERV]; 1659 int herr; 1660 int flags = NI_NUMERICSERV; 1661 1662 if (path != NULL) { 1663 fprintf(stderr, "Connection on %s received!\n", path); 1664 return; 1665 } 1666 1667 if (nflag) 1668 flags |= NI_NUMERICHOST; 1669 1670 if ((herr = getnameinfo(sa, salen, 1671 remote_host, sizeof(remote_host), 1672 remote_port, sizeof(remote_port), 1673 flags)) != 0) { 1674 if (herr == EAI_SYSTEM) 1675 err(1, "getnameinfo"); 1676 else 1677 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1678 } 1679 1680 fprintf(stderr, 1681 "Connection from %s %s " 1682 "received!\n", remote_host, remote_port); 1683 } 1684 1685 void 1686 help(void) 1687 { 1688 usage(0); 1689 fprintf(stderr, "\tCommand Summary:\n\ 1690 \t-4 Use IPv4\n\ 1691 \t-6 Use IPv6\n\ 1692 \t-C certfile Public key file\n\ 1693 \t-c Use TLS\n\ 1694 \t-D Enable the debug socket option\n\ 1695 \t-d Detach from stdin\n\ 1696 \t-e name\t Required name in peer certificate\n\ 1697 \t-F Pass socket fd\n\ 1698 \t-H hash\t Hash string of peer certificate\n\ 1699 \t-h This help text\n\ 1700 \t-I length TCP receive buffer length\n\ 1701 \t-i interval Delay interval for lines sent, ports scanned\n\ 1702 \t-K keyfile Private key file\n\ 1703 \t-k Keep inbound sockets open for multiple connects\n\ 1704 \t-l Listen mode, for inbound connects\n\ 1705 \t-M ttl Outgoing TTL / Hop Limit\n\ 1706 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1707 \t-N Shutdown the network socket after EOF on stdin\n\ 1708 \t-n Suppress name/port resolutions\n\ 1709 \t-O length TCP send buffer length\n\ 1710 \t-o staplefile Staple file\n\ 1711 \t-P proxyuser\tUsername for proxy authentication\n\ 1712 \t-p port\t Specify local port for remote connects\n\ 1713 \t-R CAfile CA bundle\n\ 1714 \t-r Randomize remote ports\n\ 1715 \t-S Enable the TCP MD5 signature option\n\ 1716 \t-s source Local source address\n\ 1717 \t-T keyword TOS value or TLS options\n\ 1718 \t-t Answer TELNET negotiation\n\ 1719 \t-U Use UNIX domain socket\n\ 1720 \t-u UDP mode\n\ 1721 \t-V rtable Specify alternate routing table\n\ 1722 \t-v Verbose\n\ 1723 \t-w timeout Timeout for connects and final net reads\n\ 1724 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1725 \t-x addr[:port]\tSpecify proxy address and port\n\ 1726 \t-Z Peer certificate file\n\ 1727 \t-z Zero-I/O mode [used for scanning]\n\ 1728 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1729 exit(1); 1730 } 1731 1732 void 1733 usage(int ret) 1734 { 1735 fprintf(stderr, 1736 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1737 "[-H hash] [-I length]\n" 1738 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1739 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1740 "[-R CAfile]\n" 1741 "\t [-s source] [-T keyword] [-V rtable] [-w timeout] " 1742 "[-X proxy_protocol]\n" 1743 "\t [-x proxy_address[:port]] [-Z peercertfile] " 1744 "[destination] [port]\n"); 1745 if (ret) 1746 exit(1); 1747 }