1 /* $OpenBSD: netcat.c,v 1.172 2017/02/05 01:39:14 jca 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 #include <sys/cdefs.h> 30 __RCSID("$NetBSD: netcat.c,v 1.5 2017/02/09 21:23:48 christos Exp $"); 31 32 /* 33 * Re-written nc(1) for OpenBSD. Original implementation by 34 * *Hobbit* <hobbit@avian.org>. 35 */ 36 37 #include <sys/types.h> 38 #include <sys/socket.h> 39 #include <sys/uio.h> 40 #include <sys/un.h> 41 42 #include <netinet/in.h> 43 #include <netinet/tcp.h> 44 #include <netinet/ip.h> 45 #include <arpa/telnet.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 #ifdef CRYPTO 60 #include <tls.h> 61 #else 62 #define TLS_WANT_POLLIN -2 63 #define TLS_WANT_POLLOUT -2 64 #endif 65 #include "atomicio.h" 66 67 #ifdef __NetBSD__ 68 #define accept4(a, b, c, d) paccept((a), (b), (c), NULL, (d)) 69 #endif 70 71 #define PORT_MAX 65535 72 #define UNIX_DG_TMP_SOCKET_SIZE 19 73 74 #define POLL_STDIN 0 75 #define POLL_NETOUT 1 76 #define POLL_NETIN 2 77 #define POLL_STDOUT 3 78 #define BUFSIZE 16384 79 #define DEFAULT_CA_FILE "/etc/ssl/cert.pem" 80 81 #define TLS_ALL (1 << 1) 82 #define TLS_NOVERIFY (1 << 2) 83 #define TLS_NONAME (1 << 3) 84 #define TLS_CCERT (1 << 4) 85 #define TLS_MUSTSTAPLE (1 << 5) 86 87 /* Command Line Options */ 88 int dflag; /* detached, no stdin */ 89 int Fflag; /* fdpass sock to stdout */ 90 unsigned int iflag; /* Interval Flag */ 91 int kflag; /* More than one connect */ 92 int lflag; /* Bind to local port */ 93 int Nflag; /* shutdown() network socket */ 94 int nflag; /* Don't do name look up */ 95 char *Pflag; /* Proxy username */ 96 char *pflag; /* Localport flag */ 97 int rflag; /* Random ports flag */ 98 char *sflag; /* Source Address */ 99 int tflag; /* Telnet Emulation */ 100 int uflag; /* UDP - Default to TCP */ 101 int vflag; /* Verbosity */ 102 int xflag; /* Socks proxy */ 103 int zflag; /* Port Scan Flag */ 104 int Dflag; /* sodebug */ 105 int Iflag; /* TCP receive buffer size */ 106 int Oflag; /* TCP send buffer size */ 107 int Sflag; /* TCP MD5 signature option */ 108 int Tflag = -1; /* IP Type of Service */ 109 #ifdef __OpenBSD__ 110 int rtableid = -1; 111 #endif 112 113 int usetls; /* use TLS */ 114 char *Cflag; /* Public cert file */ 115 char *Kflag; /* Private key file */ 116 char *oflag; /* OCSP stapling file */ 117 const char *Rflag = DEFAULT_CA_FILE; /* Root CA file */ 118 int tls_cachanged; /* Using non-default CA file */ 119 int TLSopt; /* TLS options */ 120 char *tls_expectname; /* required name in peer cert */ 121 char *tls_expecthash; /* required hash of peer cert */ 122 123 int timeout = -1; 124 int family = AF_UNSPEC; 125 char *portlist[PORT_MAX+1]; 126 char *unix_dg_tmp_socket; 127 int ttl = -1; 128 int minttl = -1; 129 130 void atelnet(int, unsigned char *, unsigned int); 131 void build_ports(char *); 132 static void help(void) __dead; 133 int local_listen(char *, char *, struct addrinfo); 134 struct tls; 135 void readwrite(int, struct tls *); 136 void fdpass(int nfd) __dead; 137 int remote_connect(const char *, const char *, struct addrinfo); 138 int timeout_connect(int, const struct sockaddr *, socklen_t); 139 int socks_connect(const char *, const char *, struct addrinfo, 140 const char *, const char *, struct addrinfo, int, const char *); 141 int udptest(int); 142 int unix_bind(char *, int); 143 int unix_connect(char *); 144 int unix_listen(char *); 145 void set_common_sockopts(int, int); 146 int map_tos(char *, int *); 147 int map_tls(char *, int *); 148 void report_connect(const struct sockaddr *, socklen_t, char *); 149 void report_tls(struct tls *tls_ctx, char * host, char *tlsexpectname); 150 void usage(int); 151 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 152 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 153 void tls_setup_client(struct tls *, int, char *); 154 struct tls *tls_setup_server(struct tls *, int, char *); 155 156 int 157 main(int argc, char *argv[]) 158 { 159 int ch, s = -1, ret, socksv; 160 char *host, *uport; 161 struct addrinfo hints; 162 struct servent *sv; 163 socklen_t len; 164 struct sockaddr_storage cliaddr; 165 char *proxy = NULL, *proxyport = NULL; 166 int errnum; 167 struct addrinfo proxyhints; 168 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 169 #ifdef CRYPTO 170 struct tls_config *tls_cfg = NULL; 171 struct tls *tls_ctx = NULL; 172 #endif 173 174 ret = 1; 175 socksv = 5; 176 host = NULL; 177 uport = NULL; 178 sv = NULL; 179 180 signal(SIGPIPE, SIG_IGN); 181 182 while ((ch = getopt(argc, argv, 183 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vw:X:x:z")) != -1) { 184 switch (ch) { 185 case '4': 186 family = AF_INET; 187 break; 188 case '6': 189 family = AF_INET6; 190 break; 191 case 'U': 192 family = AF_UNIX; 193 break; 194 case 'X': 195 if (strcasecmp(optarg, "connect") == 0) 196 socksv = -1; /* HTTP proxy CONNECT */ 197 else if (strcmp(optarg, "4") == 0) 198 socksv = 4; /* SOCKS v.4 */ 199 else if (strcmp(optarg, "5") == 0) 200 socksv = 5; /* SOCKS v.5 */ 201 else 202 errx(1, "unsupported proxy protocol"); 203 break; 204 #ifdef CRYPTO 205 case 'C': 206 Cflag = optarg; 207 break; 208 case 'c': 209 usetls = 1; 210 break; 211 #endif 212 case 'd': 213 dflag = 1; 214 break; 215 case 'e': 216 tls_expectname = optarg; 217 break; 218 case 'F': 219 Fflag = 1; 220 break; 221 #ifdef CRYPTO 222 case 'H': 223 tls_expecthash = optarg; 224 break; 225 #endif 226 case 'h': 227 help(); 228 break; 229 case 'i': 230 iflag = strtoi(optarg, NULL, 0, 0, UINT_MAX, &errnum); 231 if (errnum) 232 errc(1, errnum, "bad interval `%s'", optarg); 233 break; 234 #ifdef CRYPTO 235 case 'K': 236 Kflag = optarg; 237 break; 238 #endif 239 case 'k': 240 kflag = 1; 241 break; 242 case 'l': 243 lflag = 1; 244 break; 245 case 'M': 246 ttl = strtoi(optarg, NULL, 0, 0, 255, &errnum); 247 if (errnum) 248 errc(1, errnum, "bad ttl `%s'", optarg); 249 break; 250 case 'm': 251 minttl = strtoi(optarg, NULL, 0, 0, 255, &errnum); 252 if (errnum) 253 errc(1, errnum, "bad minttl `%s'", optarg); 254 break; 255 case 'N': 256 Nflag = 1; 257 break; 258 case 'n': 259 nflag = 1; 260 break; 261 case 'P': 262 Pflag = optarg; 263 break; 264 case 'p': 265 pflag = optarg; 266 break; 267 #ifdef CRYPTO 268 case 'R': 269 tls_cachanged = 1; 270 Rflag = optarg; 271 break; 272 #endif 273 case 'r': 274 rflag = 1; 275 break; 276 case 's': 277 sflag = optarg; 278 break; 279 case 't': 280 tflag = 1; 281 break; 282 case 'u': 283 uflag = 1; 284 break; 285 #ifdef __OpenBSD__ 286 case 'V': 287 rtableid = (int)strtoi(optarg, NULL, 0, 0, 255, &errnum); 288 if (errnum) 289 errc(1, errnum, "bad rtable `%s'", optarg); 290 break; 291 #endif 292 case 'v': 293 vflag = 1; 294 break; 295 case 'w': 296 timeout = strtoi(optarg, NULL, 0, 0, INT_MAX / 1000, &errnum); 297 if (errnum) 298 errc(1, errnum, "bad timeout `%s'", optarg); 299 timeout *= 1000; 300 break; 301 case 'x': 302 xflag = 1; 303 if ((proxy = strdup(optarg)) == NULL) 304 err(1, NULL); 305 break; 306 case 'z': 307 zflag = 1; 308 break; 309 case 'D': 310 Dflag = 1; 311 break; 312 case 'I': 313 Iflag = strtoi(optarg, NULL, 0, 1, 65536 << 14, &errnum); 314 if (errnum) 315 errc(1, errnum, "bad TCP receive window `%s'", 316 optarg); 317 break; 318 case 'O': 319 Oflag = strtoi(optarg, NULL, 0, 1, 65536 << 14, &errnum); 320 if (errnum) 321 errc(1, errnum, "bad TCP send window `%s'", 322 optarg); 323 break; 324 #ifdef CRYPTO 325 case 'o': 326 oflag = optarg; 327 break; 328 #endif 329 case 'S': 330 Sflag = 1; 331 break; 332 #ifdef CRYPTO 333 case 'T': 334 if (map_tos(optarg, &Tflag)) 335 break; 336 if (map_tls(optarg, &TLSopt)) 337 break; 338 Tflag = (int)strtoi(optarg, NULL, 0, 0, 255, &errnum); 339 if (errnum) 340 errc(1, errnum, "illegal tos/tls value `%s'", 341 optarg); 342 break; 343 #endif 344 default: 345 usage(1); 346 } 347 } 348 argc -= optind; 349 argv += optind; 350 351 #ifdef __OpenBSD__ 352 if (rtableid >= 0) 353 if (setrtable(rtableid) == -1) 354 err(1, "setrtable"); 355 356 if (family == AF_UNIX) { 357 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 358 err(1, "pledge"); 359 } else if (Fflag) { 360 if (Pflag) { 361 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 362 err(1, "pledge"); 363 } else if (pledge("stdio inet dns sendfd", NULL) == -1) 364 err(1, "pledge"); 365 } else if (Pflag) { 366 if (pledge("stdio inet dns tty", NULL) == -1) 367 err(1, "pledge"); 368 } else if (usetls) { 369 if (pledge("stdio rpath inet dns", NULL) == -1) 370 err(1, "pledge"); 371 } else if (pledge("stdio inet dns", NULL) == -1) 372 err(1, "pledge"); 373 #endif 374 375 /* Cruft to make sure options are clean, and used properly. */ 376 if (argv[0] && !argv[1] && family == AF_UNIX) { 377 host = argv[0]; 378 uport = NULL; 379 } else if (argv[0] && !argv[1]) { 380 if (!lflag) 381 usage(1); 382 uport = argv[0]; 383 host = NULL; 384 } else if (argv[0] && argv[1]) { 385 host = argv[0]; 386 uport = argv[1]; 387 } else 388 usage(1); 389 390 if (lflag && sflag) 391 errx(1, "cannot use -s and -l"); 392 if (lflag && pflag) 393 errx(1, "cannot use -p and -l"); 394 if (lflag && zflag) 395 errx(1, "cannot use -z and -l"); 396 if (!lflag && kflag) 397 errx(1, "must use -l with -k"); 398 if (uflag && usetls) 399 errx(1, "cannot use -c and -u"); 400 if ((family == AF_UNIX) && usetls) 401 errx(1, "cannot use -c and -U"); 402 if ((family == AF_UNIX) && Fflag) 403 errx(1, "cannot use -F and -U"); 404 if (Fflag && usetls) 405 errx(1, "cannot use -c and -F"); 406 #ifdef CRYPTO 407 if (TLSopt && !usetls) 408 errx(1, "you must specify -c to use TLS options"); 409 if (Cflag && !usetls) 410 errx(1, "you must specify -c to use -C"); 411 if (Kflag && !usetls) 412 errx(1, "you must specify -c to use -K"); 413 if (oflag && !Cflag) 414 errx(1, "you must specify -C to use -o"); 415 if (tls_cachanged && !usetls) 416 errx(1, "you must specify -c to use -R"); 417 if (tls_expecthash && !usetls) 418 errx(1, "you must specify -c to use -H"); 419 if (tls_expectname && !usetls) 420 errx(1, "you must specify -c to use -e"); 421 #endif 422 423 /* Get name of temporary socket for unix datagram client */ 424 if ((family == AF_UNIX) && uflag && !lflag) { 425 if (sflag) { 426 unix_dg_tmp_socket = sflag; 427 } else { 428 int fd; 429 snprintf(unix_dg_tmp_socket_buf, 430 sizeof(unix_dg_tmp_socket_buf), 431 "/tmp/%s.XXXXXXXXXX", getprogname()); 432 /* XXX: abstract sockets instead? */ 433 if ((fd = mkstemp(unix_dg_tmp_socket_buf)) == -1) 434 err(1, "mktemp"); 435 close(fd); 436 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 437 } 438 } 439 440 /* Initialize addrinfo structure. */ 441 if (family != AF_UNIX) { 442 memset(&hints, 0, sizeof(struct addrinfo)); 443 hints.ai_family = family; 444 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 445 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 446 if (nflag) 447 hints.ai_flags |= AI_NUMERICHOST; 448 } 449 450 if (xflag) { 451 if (uflag) 452 errx(1, "no proxy support for UDP mode"); 453 454 if (lflag) 455 errx(1, "no proxy support for listen"); 456 457 if (family == AF_UNIX) 458 errx(1, "no proxy support for unix sockets"); 459 460 if (sflag) 461 errx(1, "no proxy support for local source address"); 462 463 if (*proxy == '[') { 464 ++proxy; 465 proxyport = strchr(proxy, ']'); 466 if (proxyport == NULL) 467 errx(1, "missing closing bracket in proxy"); 468 *proxyport++ = '\0'; 469 if (*proxyport == '\0') 470 /* Use default proxy port. */ 471 proxyport = NULL; 472 else { 473 if (*proxyport == ':') 474 ++proxyport; 475 else 476 errx(1, "garbage proxy port delimiter"); 477 } 478 } else { 479 proxyport = strrchr(proxy, ':'); 480 if (proxyport != NULL) 481 *proxyport++ = '\0'; 482 } 483 484 memset(&proxyhints, 0, sizeof(struct addrinfo)); 485 proxyhints.ai_family = family; 486 proxyhints.ai_socktype = SOCK_STREAM; 487 proxyhints.ai_protocol = IPPROTO_TCP; 488 if (nflag) 489 proxyhints.ai_flags |= AI_NUMERICHOST; 490 } 491 492 #ifdef CRYPTO 493 if (usetls) { 494 #if __OpenBSD__ 495 if (Pflag) { 496 if (pledge("stdio inet dns tty rpath", NULL) == -1) 497 err(1, "pledge"); 498 } else if (pledge("stdio inet dns rpath", NULL) == -1) 499 err(1, "pledge"); 500 #endif 501 502 if (tls_init() == -1) 503 errx(1, "unable to initialize TLS"); 504 if ((tls_cfg = tls_config_new()) == NULL) 505 errx(1, "unable to allocate TLS config"); 506 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 507 errx(1, "%s", tls_config_error(tls_cfg)); 508 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 509 errx(1, "%s", tls_config_error(tls_cfg)); 510 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 511 errx(1, "%s", tls_config_error(tls_cfg)); 512 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 513 errx(1, "%s", tls_config_error(tls_cfg)); 514 if (TLSopt & TLS_ALL) { 515 if (tls_config_set_protocols(tls_cfg, 516 TLS_PROTOCOLS_ALL) != 0) 517 errx(1, "%s", tls_config_error(tls_cfg)); 518 if (tls_config_set_ciphers(tls_cfg, "all") != 0) 519 errx(1, "%s", tls_config_error(tls_cfg)); 520 } 521 if (!lflag && (TLSopt & TLS_CCERT)) 522 errx(1, "clientcert is only valid with -l"); 523 if (TLSopt & TLS_NONAME) 524 tls_config_insecure_noverifyname(tls_cfg); 525 if (TLSopt & TLS_NOVERIFY) { 526 if (tls_expecthash != NULL) 527 errx(1, "-H and -T noverify may not be used" 528 "together"); 529 tls_config_insecure_noverifycert(tls_cfg); 530 } 531 if (TLSopt & TLS_MUSTSTAPLE) 532 tls_config_ocsp_require_stapling(tls_cfg); 533 534 #ifdef __OpenBSD__ 535 if (Pflag) { 536 if (pledge("stdio inet dns tty", NULL) == -1) 537 err(1, "pledge"); 538 } else if (pledge("stdio inet dns", NULL) == -1) 539 err(1, "pledge"); 540 #endif 541 } 542 #endif 543 if (lflag) { 544 #ifdef CRYPTO 545 struct tls *tls_cctx = NULL; 546 #endif 547 int connfd; 548 ret = 0; 549 550 if (family == AF_UNIX) { 551 if (uflag) 552 s = unix_bind(host, 0); 553 else 554 s = unix_listen(host); 555 } 556 557 #ifdef CRYPTO 558 if (usetls) { 559 tls_config_verify_client_optional(tls_cfg); 560 if ((tls_ctx = tls_server()) == NULL) 561 errx(1, "tls server creation failed"); 562 if (tls_configure(tls_ctx, tls_cfg) == -1) 563 errx(1, "tls configuration failed (%s)", 564 tls_error(tls_ctx)); 565 } 566 #endif 567 /* Allow only one connection at a time, but stay alive. */ 568 for (;;) { 569 if (family != AF_UNIX) 570 s = local_listen(host, uport, hints); 571 if (s < 0) 572 err(1, NULL); 573 /* 574 * For UDP and -k, don't connect the socket, let it 575 * receive datagrams from multiple socket pairs. 576 */ 577 if (uflag && kflag) 578 readwrite(s, NULL); 579 /* 580 * For UDP and not -k, we will use recvfrom() initially 581 * to wait for a caller, then use the regular functions 582 * to talk to the caller. 583 */ 584 else if (uflag && !kflag) { 585 int rv, plen; 586 char buf[16384]; 587 struct sockaddr_storage z; 588 589 len = sizeof(z); 590 plen = 2048; 591 rv = recvfrom(s, buf, plen, MSG_PEEK, 592 (struct sockaddr *)&z, &len); 593 if (rv < 0) 594 err(1, "recvfrom"); 595 596 rv = connect(s, (struct sockaddr *)&z, len); 597 if (rv < 0) 598 err(1, "connect"); 599 600 if (vflag) 601 report_connect((struct sockaddr *)&z, len, NULL); 602 603 readwrite(s, NULL); 604 } else { 605 len = sizeof(cliaddr); 606 connfd = accept4(s, (struct sockaddr *)&cliaddr, 607 &len, SOCK_NONBLOCK); 608 if (connfd == -1) { 609 /* For now, all errnos are fatal */ 610 err(1, "accept"); 611 } 612 if (vflag) 613 report_connect((struct sockaddr *)&cliaddr, len, 614 family == AF_UNIX ? host : NULL); 615 #ifdef CRYPTO 616 if ((usetls) && 617 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 618 readwrite(connfd, tls_cctx); 619 if (!usetls) 620 #endif 621 readwrite(connfd, NULL); 622 #ifdef CRYPTO 623 if (tls_cctx) { 624 int i; 625 626 do { 627 i = tls_close(tls_cctx); 628 } while (i == TLS_WANT_POLLIN || 629 i == TLS_WANT_POLLOUT); 630 tls_free(tls_cctx); 631 tls_cctx = NULL; 632 } 633 #endif 634 close(connfd); 635 } 636 if (family != AF_UNIX) 637 close(s); 638 else if (uflag) { 639 if (connect(s, NULL, 0) < 0) 640 err(1, "connect"); 641 } 642 643 if (!kflag) 644 break; 645 } 646 } else if (family == AF_UNIX) { 647 ret = 0; 648 649 if ((s = unix_connect(host)) > 0 && !zflag) { 650 readwrite(s, NULL); 651 close(s); 652 } else 653 ret = 1; 654 655 if (uflag) 656 unlink(unix_dg_tmp_socket); 657 exit(ret); 658 659 } else { 660 int i = 0; 661 662 /* Construct the portlist[] array. */ 663 build_ports(uport); 664 665 /* Cycle through portlist, connecting to each port. */ 666 for (s = -1, i = 0; portlist[i] != NULL; i++) { 667 if (s != -1) 668 close(s); 669 670 #ifdef CRYPTO 671 if (usetls) { 672 if ((tls_ctx = tls_client()) == NULL) 673 errx(1, "tls client creation failed"); 674 if (tls_configure(tls_ctx, tls_cfg) == -1) 675 errx(1, "tls configuration failed (%s)", 676 tls_error(tls_ctx)); 677 } 678 #endif 679 if (xflag) 680 s = socks_connect(host, portlist[i], hints, 681 proxy, proxyport, proxyhints, socksv, 682 Pflag); 683 else 684 s = remote_connect(host, portlist[i], hints); 685 686 if (s == -1) 687 continue; 688 689 ret = 0; 690 if (vflag || zflag) { 691 /* For UDP, make sure we are connected. */ 692 if (uflag) { 693 if (udptest(s) == -1) { 694 ret = 1; 695 continue; 696 } 697 } 698 699 /* Don't look up port if -n. */ 700 if (nflag) 701 sv = NULL; 702 else { 703 sv = getservbyport( 704 ntohs(atoi(portlist[i])), 705 uflag ? "udp" : "tcp"); 706 } 707 708 fprintf(stderr, 709 "Connection to %s %s port [%s/%s] " 710 "succeeded!\n", host, portlist[i], 711 uflag ? "udp" : "tcp", 712 sv ? sv->s_name : "*"); 713 } 714 if (Fflag) 715 fdpass(s); 716 else { 717 #ifdef CRYPTO 718 if (usetls) 719 tls_setup_client(tls_ctx, s, host); 720 if (!zflag) 721 readwrite(s, tls_ctx); 722 if (tls_ctx) { 723 int j; 724 725 do { 726 j = tls_close(tls_ctx); 727 } while (j == TLS_WANT_POLLIN || 728 j == TLS_WANT_POLLOUT); 729 tls_free(tls_ctx); 730 tls_ctx = NULL; 731 } 732 #else 733 if (!zflag) 734 readwrite(s, NULL); 735 #endif 736 } 737 } 738 } 739 740 if (s != -1) 741 close(s); 742 743 #ifdef CRYPTO 744 tls_config_free(tls_cfg); 745 #endif 746 747 exit(ret); 748 } 749 750 /* 751 * unix_bind() 752 * Returns a unix socket bound to the given path 753 */ 754 int 755 unix_bind(char *path, int flags) 756 { 757 struct sockaddr_un s_un; 758 int s, save_errno; 759 760 /* Create unix domain socket. */ 761 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 762 0)) < 0) 763 return (-1); 764 765 memset(&s_un, 0, sizeof(struct sockaddr_un)); 766 s_un.sun_family = AF_UNIX; 767 768 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 769 sizeof(s_un.sun_path)) { 770 close(s); 771 errno = ENAMETOOLONG; 772 return (-1); 773 } 774 775 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 776 save_errno = errno; 777 close(s); 778 errno = save_errno; 779 return (-1); 780 } 781 return (s); 782 } 783 784 #ifdef CRYPTO 785 void 786 tls_setup_client(struct tls *tls_ctx, int s, char *host) 787 { 788 int i; 789 790 if (tls_connect_socket(tls_ctx, s, 791 tls_expectname ? tls_expectname : host) == -1) { 792 errx(1, "tls connection failed (%s)", 793 tls_error(tls_ctx)); 794 } 795 do { 796 if ((i = tls_handshake(tls_ctx)) == -1) 797 errx(1, "tls handshake failed (%s)", 798 tls_error(tls_ctx)); 799 } while (i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 800 if (vflag) 801 report_tls(tls_ctx, host, tls_expectname); 802 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 803 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 804 errx(1, "peer certificate is not %s", tls_expecthash); 805 } 806 807 struct tls * 808 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 809 { 810 struct tls *tls_cctx; 811 812 if (tls_accept_socket(tls_ctx, &tls_cctx, 813 connfd) == -1) { 814 warnx("tls accept failed (%s)", 815 tls_error(tls_ctx)); 816 tls_cctx = NULL; 817 } else { 818 int i; 819 820 do { 821 if ((i = tls_handshake(tls_cctx)) == -1) 822 warnx("tls handshake failed (%s)", 823 tls_error(tls_cctx)); 824 } while(i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 825 } 826 if (tls_cctx) { 827 int gotcert = tls_peer_cert_provided(tls_cctx); 828 829 if (vflag && gotcert) 830 report_tls(tls_cctx, host, tls_expectname); 831 if ((TLSopt & TLS_CCERT) && !gotcert) 832 warnx("No client certificate provided"); 833 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 834 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 835 warnx("peer certificate is not %s", tls_expecthash); 836 else if (gotcert && tls_expectname && 837 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 838 warnx("name (%s) not found in client cert", 839 tls_expectname); 840 else { 841 return tls_cctx; 842 } 843 } 844 return NULL; 845 } 846 #endif 847 848 /* 849 * unix_connect() 850 * Returns a socket connected to a local unix socket. Returns -1 on failure. 851 */ 852 int 853 unix_connect(char *path) 854 { 855 struct sockaddr_un s_un; 856 int s, save_errno; 857 858 if (uflag) { 859 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 860 return (-1); 861 } else { 862 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 863 return (-1); 864 } 865 866 memset(&s_un, 0, sizeof(struct sockaddr_un)); 867 s_un.sun_family = AF_UNIX; 868 869 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 870 sizeof(s_un.sun_path)) { 871 close(s); 872 errno = ENAMETOOLONG; 873 return (-1); 874 } 875 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 876 save_errno = errno; 877 close(s); 878 errno = save_errno; 879 return (-1); 880 } 881 return (s); 882 883 } 884 885 /* 886 * unix_listen() 887 * Create a unix domain socket, and listen on it. 888 */ 889 int 890 unix_listen(char *path) 891 { 892 int s; 893 if ((s = unix_bind(path, 0)) < 0) 894 return (-1); 895 896 if (listen(s, 5) < 0) { 897 close(s); 898 return (-1); 899 } 900 return (s); 901 } 902 903 /* 904 * remote_connect() 905 * Returns a socket connected to a remote host. Properly binds to a local 906 * port or source address if needed. Returns -1 on failure. 907 */ 908 int 909 remote_connect(const char *host, const char *port, struct addrinfo hints) 910 { 911 struct addrinfo *res, *res0; 912 int s = -1, error, save_errno; 913 914 if ((error = getaddrinfo(host, port, &hints, &res0))) 915 errx(1, "getaddrinfo: %s", gai_strerror(error)); 916 917 for (res = res0; res; res = res->ai_next) { 918 if ((s = socket(res->ai_family, res->ai_socktype | 919 SOCK_NONBLOCK, res->ai_protocol)) < 0) 920 continue; 921 922 /* Bind to a local port or source address if specified. */ 923 if (sflag || pflag) { 924 struct addrinfo ahints, *ares; 925 926 #ifdef SO_BINDANY 927 /* try SO_BINDANY, but don't insist */ 928 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 929 #endif 930 memset(&ahints, 0, sizeof(struct addrinfo)); 931 ahints.ai_family = res->ai_family; 932 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 933 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 934 ahints.ai_flags = AI_PASSIVE; 935 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 936 errx(1, "getaddrinfo: %s", gai_strerror(error)); 937 938 if (bind(s, (struct sockaddr *)ares->ai_addr, 939 ares->ai_addrlen) < 0) 940 err(1, "bind failed"); 941 freeaddrinfo(ares); 942 } 943 944 set_common_sockopts(s, res->ai_family); 945 946 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 947 break; 948 if (vflag) 949 warn("connect to %s port %s (%s) failed", host, port, 950 uflag ? "udp" : "tcp"); 951 952 save_errno = errno; 953 close(s); 954 errno = save_errno; 955 s = -1; 956 } 957 958 freeaddrinfo(res0); 959 960 return (s); 961 } 962 963 int 964 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 965 { 966 struct pollfd pfd; 967 socklen_t optlen; 968 int optval; 969 int ret; 970 971 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 972 pfd.fd = s; 973 pfd.events = POLLOUT; 974 if ((ret = poll(&pfd, 1, timeout)) == 1) { 975 optlen = sizeof(optval); 976 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 977 &optval, &optlen)) == 0) { 978 errno = optval; 979 ret = optval == 0 ? 0 : -1; 980 } 981 } else if (ret == 0) { 982 errno = ETIMEDOUT; 983 ret = -1; 984 } else 985 err(1, "poll failed"); 986 } 987 988 return (ret); 989 } 990 991 /* 992 * local_listen() 993 * Returns a socket listening on a local port, binds to specified source 994 * address. Returns -1 on failure. 995 */ 996 int 997 local_listen(char *host, char *port, struct addrinfo hints) 998 { 999 struct addrinfo *res, *res0; 1000 int s = -1, ret, x = 1, save_errno; 1001 int error; 1002 1003 /* Allow nodename to be null. */ 1004 hints.ai_flags |= AI_PASSIVE; 1005 1006 /* 1007 * In the case of binding to a wildcard address 1008 * default to binding to an ipv4 address. 1009 */ 1010 if (host == NULL && hints.ai_family == AF_UNSPEC) 1011 hints.ai_family = AF_INET; 1012 1013 if ((error = getaddrinfo(host, port, &hints, &res0))) 1014 errx(1, "getaddrinfo: %s", gai_strerror(error)); 1015 1016 for (res = res0; res; res = res->ai_next) { 1017 if ((s = socket(res->ai_family, res->ai_socktype, 1018 res->ai_protocol)) < 0) 1019 continue; 1020 1021 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 1022 if (ret == -1) 1023 err(1, NULL); 1024 1025 set_common_sockopts(s, res->ai_family); 1026 1027 if (bind(s, (struct sockaddr *)res->ai_addr, 1028 res->ai_addrlen) == 0) 1029 break; 1030 1031 save_errno = errno; 1032 close(s); 1033 errno = save_errno; 1034 s = -1; 1035 } 1036 1037 if (!uflag && s != -1) { 1038 if (listen(s, 1) < 0) 1039 err(1, "listen"); 1040 } 1041 1042 freeaddrinfo(res0); 1043 1044 return (s); 1045 } 1046 1047 /* 1048 * readwrite() 1049 * Loop that polls on the network file descriptor and stdin. 1050 */ 1051 void 1052 readwrite(int net_fd, struct tls *tls_ctx) 1053 { 1054 struct pollfd pfd[4]; 1055 int stdin_fd = STDIN_FILENO; 1056 int stdout_fd = STDOUT_FILENO; 1057 unsigned char netinbuf[BUFSIZE]; 1058 size_t netinbufpos = 0; 1059 unsigned char stdinbuf[BUFSIZE]; 1060 size_t stdinbufpos = 0; 1061 int n, num_fds; 1062 ssize_t ret; 1063 1064 /* don't read from stdin if requested */ 1065 if (dflag) 1066 stdin_fd = -1; 1067 1068 /* stdin */ 1069 pfd[POLL_STDIN].fd = stdin_fd; 1070 pfd[POLL_STDIN].events = POLLIN; 1071 1072 /* network out */ 1073 pfd[POLL_NETOUT].fd = net_fd; 1074 pfd[POLL_NETOUT].events = 0; 1075 1076 /* network in */ 1077 pfd[POLL_NETIN].fd = net_fd; 1078 pfd[POLL_NETIN].events = POLLIN; 1079 1080 /* stdout */ 1081 pfd[POLL_STDOUT].fd = stdout_fd; 1082 pfd[POLL_STDOUT].events = 0; 1083 1084 while (1) { 1085 /* both inputs are gone, buffers are empty, we are done */ 1086 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1087 stdinbufpos == 0 && netinbufpos == 0) { 1088 close(net_fd); 1089 return; 1090 } 1091 /* both outputs are gone, we can't continue */ 1092 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 1093 close(net_fd); 1094 return; 1095 } 1096 /* listen and net in gone, queues empty, done */ 1097 if (lflag && pfd[POLL_NETIN].fd == -1 && 1098 stdinbufpos == 0 && netinbufpos == 0) { 1099 close(net_fd); 1100 return; 1101 } 1102 1103 /* help says -i is for "wait between lines sent". We read and 1104 * write arbitrary amounts of data, and we don't want to start 1105 * scanning for newlines, so this is as good as it gets */ 1106 if (iflag) 1107 sleep(iflag); 1108 1109 /* poll */ 1110 num_fds = poll(pfd, 4, timeout); 1111 1112 /* treat poll errors */ 1113 if (num_fds == -1) { 1114 close(net_fd); 1115 err(1, "polling error"); 1116 } 1117 1118 /* timeout happened */ 1119 if (num_fds == 0) 1120 return; 1121 1122 /* treat socket error conditions */ 1123 for (n = 0; n < 4; n++) { 1124 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1125 pfd[n].fd = -1; 1126 } 1127 } 1128 /* reading is possible after HUP */ 1129 if (pfd[POLL_STDIN].events & POLLIN && 1130 pfd[POLL_STDIN].revents & POLLHUP && 1131 !(pfd[POLL_STDIN].revents & POLLIN)) 1132 pfd[POLL_STDIN].fd = -1; 1133 1134 if (pfd[POLL_NETIN].events & POLLIN && 1135 pfd[POLL_NETIN].revents & POLLHUP && 1136 !(pfd[POLL_NETIN].revents & POLLIN)) 1137 pfd[POLL_NETIN].fd = -1; 1138 1139 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1140 if (Nflag) 1141 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1142 pfd[POLL_NETOUT].fd = -1; 1143 } 1144 /* if HUP, stop watching stdout */ 1145 if (pfd[POLL_STDOUT].revents & POLLHUP) 1146 pfd[POLL_STDOUT].fd = -1; 1147 /* if no net out, stop watching stdin */ 1148 if (pfd[POLL_NETOUT].fd == -1) 1149 pfd[POLL_STDIN].fd = -1; 1150 /* if no stdout, stop watching net in */ 1151 if (pfd[POLL_STDOUT].fd == -1) { 1152 if (pfd[POLL_NETIN].fd != -1) 1153 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1154 pfd[POLL_NETIN].fd = -1; 1155 } 1156 1157 /* try to read from stdin */ 1158 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1159 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1160 &stdinbufpos, NULL); 1161 if (ret == TLS_WANT_POLLIN) 1162 pfd[POLL_STDIN].events = POLLIN; 1163 else if (ret == TLS_WANT_POLLOUT) 1164 pfd[POLL_STDIN].events = POLLOUT; 1165 else if (ret == 0 || ret == -1) 1166 pfd[POLL_STDIN].fd = -1; 1167 /* read something - poll net out */ 1168 if (stdinbufpos > 0) 1169 pfd[POLL_NETOUT].events = POLLOUT; 1170 /* filled buffer - remove self from polling */ 1171 if (stdinbufpos == BUFSIZE) 1172 pfd[POLL_STDIN].events = 0; 1173 } 1174 /* try to write to network */ 1175 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1176 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1177 &stdinbufpos, tls_ctx); 1178 if (ret == TLS_WANT_POLLIN) 1179 pfd[POLL_NETOUT].events = POLLIN; 1180 else if (ret == TLS_WANT_POLLOUT) 1181 pfd[POLL_NETOUT].events = POLLOUT; 1182 else if (ret == -1) 1183 pfd[POLL_NETOUT].fd = -1; 1184 /* buffer empty - remove self from polling */ 1185 if (stdinbufpos == 0) 1186 pfd[POLL_NETOUT].events = 0; 1187 /* buffer no longer full - poll stdin again */ 1188 if (stdinbufpos < BUFSIZE) 1189 pfd[POLL_STDIN].events = POLLIN; 1190 } 1191 /* try to read from network */ 1192 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1193 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1194 &netinbufpos, tls_ctx); 1195 if (ret == TLS_WANT_POLLIN) 1196 pfd[POLL_NETIN].events = POLLIN; 1197 else if (ret == TLS_WANT_POLLOUT) 1198 pfd[POLL_NETIN].events = POLLOUT; 1199 else if (ret == -1) 1200 pfd[POLL_NETIN].fd = -1; 1201 /* eof on net in - remove from pfd */ 1202 if (ret == 0) { 1203 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1204 pfd[POLL_NETIN].fd = -1; 1205 } 1206 /* read something - poll stdout */ 1207 if (netinbufpos > 0) 1208 pfd[POLL_STDOUT].events = POLLOUT; 1209 /* filled buffer - remove self from polling */ 1210 if (netinbufpos == BUFSIZE) 1211 pfd[POLL_NETIN].events = 0; 1212 /* handle telnet */ 1213 if (tflag) 1214 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1215 netinbufpos); 1216 } 1217 /* try to write to stdout */ 1218 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1219 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1220 &netinbufpos, NULL); 1221 if (ret == TLS_WANT_POLLIN) 1222 pfd[POLL_STDOUT].events = POLLIN; 1223 else if (ret == TLS_WANT_POLLOUT) 1224 pfd[POLL_STDOUT].events = POLLOUT; 1225 else if (ret == -1) 1226 pfd[POLL_STDOUT].fd = -1; 1227 /* buffer empty - remove self from polling */ 1228 if (netinbufpos == 0) 1229 pfd[POLL_STDOUT].events = 0; 1230 /* buffer no longer full - poll net in again */ 1231 if (netinbufpos < BUFSIZE) 1232 pfd[POLL_NETIN].events = POLLIN; 1233 } 1234 1235 /* stdin gone and queue empty? */ 1236 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1237 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1238 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1239 pfd[POLL_NETOUT].fd = -1; 1240 } 1241 /* net in gone and queue empty? */ 1242 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1243 pfd[POLL_STDOUT].fd = -1; 1244 } 1245 } 1246 } 1247 1248 ssize_t 1249 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1250 { 1251 ssize_t n; 1252 ssize_t adjust; 1253 1254 #ifdef CRYPTO 1255 if (tls) 1256 n = tls_write(tls, buf, *bufpos); 1257 else 1258 #endif 1259 { 1260 n = write(fd, buf, *bufpos); 1261 /* don't treat EAGAIN, EINTR as error */ 1262 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1263 n = TLS_WANT_POLLOUT; 1264 } 1265 if (n <= 0) 1266 return n; 1267 /* adjust buffer */ 1268 adjust = *bufpos - n; 1269 if (adjust > 0) 1270 memmove(buf, buf + n, adjust); 1271 *bufpos -= n; 1272 return n; 1273 } 1274 1275 ssize_t 1276 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1277 { 1278 size_t num = BUFSIZE - *bufpos; 1279 ssize_t n; 1280 1281 #ifdef CRYPTO 1282 if (tls) 1283 n = tls_read(tls, buf + *bufpos, num); 1284 else 1285 #endif 1286 { 1287 1288 n = read(fd, buf + *bufpos, num); 1289 /* don't treat EAGAIN, EINTR as error */ 1290 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1291 n = TLS_WANT_POLLIN; 1292 } 1293 if (n <= 0) 1294 return n; 1295 *bufpos += n; 1296 return n; 1297 } 1298 1299 /* 1300 * fdpass() 1301 * Pass the connected file descriptor to stdout and exit. 1302 */ 1303 void 1304 fdpass(int nfd) 1305 { 1306 struct msghdr mh; 1307 union { 1308 struct cmsghdr hdr; 1309 char buf[CMSG_SPACE(sizeof(int))]; 1310 } cmsgbuf; 1311 struct cmsghdr *cmsg; 1312 struct iovec iov; 1313 char c = '\0'; 1314 ssize_t r; 1315 struct pollfd pfd; 1316 1317 /* Avoid obvious stupidity */ 1318 if (isatty(STDOUT_FILENO)) 1319 errx(1, "Cannot pass file descriptor to tty"); 1320 1321 bzero(&mh, sizeof(mh)); 1322 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1323 bzero(&iov, sizeof(iov)); 1324 1325 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1326 mh.msg_controllen = sizeof(cmsgbuf.buf); 1327 cmsg = CMSG_FIRSTHDR(&mh); 1328 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1329 cmsg->cmsg_level = SOL_SOCKET; 1330 cmsg->cmsg_type = SCM_RIGHTS; 1331 *(int *)CMSG_DATA(cmsg) = nfd; 1332 1333 iov.iov_base = &c; 1334 iov.iov_len = 1; 1335 mh.msg_iov = &iov; 1336 mh.msg_iovlen = 1; 1337 1338 bzero(&pfd, sizeof(pfd)); 1339 pfd.fd = STDOUT_FILENO; 1340 pfd.events = POLLOUT; 1341 for (;;) { 1342 r = sendmsg(STDOUT_FILENO, &mh, 0); 1343 if (r == -1) { 1344 if (errno == EAGAIN || errno == EINTR) { 1345 if (poll(&pfd, 1, -1) == -1) 1346 err(1, "poll"); 1347 continue; 1348 } 1349 err(1, "sendmsg"); 1350 } else if (r != 1) 1351 errx(1, "sendmsg: unexpected return value %zd", r); 1352 else 1353 break; 1354 } 1355 exit(0); 1356 } 1357 1358 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1359 void 1360 atelnet(int nfd, unsigned char *buf, unsigned int size) 1361 { 1362 unsigned char *p, *end; 1363 unsigned char obuf[4]; 1364 1365 if (size < 3) 1366 return; 1367 end = buf + size - 2; 1368 1369 for (p = buf; p < end; p++) { 1370 if (*p != IAC) 1371 continue; 1372 1373 obuf[0] = IAC; 1374 p++; 1375 if ((*p == WILL) || (*p == WONT)) 1376 obuf[1] = DONT; 1377 else if ((*p == DO) || (*p == DONT)) 1378 obuf[1] = WONT; 1379 else 1380 continue; 1381 1382 p++; 1383 obuf[2] = *p; 1384 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1385 warn("Write Error!"); 1386 } 1387 } 1388 1389 1390 static int 1391 strtoport(const char *portstr, int udp) 1392 { 1393 struct servent *entry; 1394 int errnum; 1395 const char *proto; 1396 int port; 1397 1398 proto = udp ? "udp" : "tcp"; 1399 1400 port = strtoi(portstr, NULL, 0, 1, PORT_MAX, &errnum); 1401 if (errnum == 0) 1402 return port; 1403 if ((entry = getservbyname(portstr, proto)) == NULL) 1404 errx(1, "service \"%s\" unknown", portstr); 1405 return ntohs(entry->s_port); 1406 } 1407 1408 /* 1409 * build_ports() 1410 * Build an array of ports in portlist[], listing each port 1411 * that we should try to connect to. 1412 */ 1413 void 1414 build_ports(char *p) 1415 { 1416 char *n; 1417 int hi, lo, cp; 1418 int x = 0; 1419 1420 if ((n = strchr(p, '-')) != NULL) { 1421 *n = '\0'; 1422 n++; 1423 1424 /* Make sure the ports are in order: lowest->highest. */ 1425 hi = strtoport(n, uflag); 1426 lo = strtoport(p, uflag); 1427 if (lo > hi) { 1428 cp = hi; 1429 hi = lo; 1430 lo = cp; 1431 } 1432 1433 /* 1434 * Initialize portlist with a random permutation. Based on 1435 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1436 */ 1437 if (rflag) { 1438 for (x = 0; x <= hi - lo; x++) { 1439 cp = arc4random_uniform(x + 1); 1440 portlist[x] = portlist[cp]; 1441 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1442 err(1, "asprintf"); 1443 } 1444 } else { /* Load ports sequentially. */ 1445 for (cp = lo; cp <= hi; cp++) { 1446 if (asprintf(&portlist[x], "%d", cp) < 0) 1447 err(1, "asprintf"); 1448 x++; 1449 } 1450 } 1451 } else { 1452 char *tmp; 1453 1454 hi = strtoport(p, uflag); 1455 if (asprintf(&tmp, "%d", hi) != -1) 1456 portlist[0] = tmp; 1457 else 1458 err(1, NULL); 1459 } 1460 } 1461 1462 /* 1463 * udptest() 1464 * Do a few writes to see if the UDP port is there. 1465 * Fails once PF state table is full. 1466 */ 1467 int 1468 udptest(int s) 1469 { 1470 int i, ret; 1471 1472 for (i = 0; i <= 3; i++) { 1473 if (write(s, "X", 1) == 1) 1474 ret = 1; 1475 else 1476 ret = -1; 1477 } 1478 return (ret); 1479 } 1480 1481 void 1482 set_common_sockopts(int s, int af) 1483 { 1484 int x = 1; 1485 1486 if (Sflag) { 1487 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1488 &x, sizeof(x)) == -1) 1489 err(1, NULL); 1490 } 1491 if (Dflag) { 1492 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1493 &x, sizeof(x)) == -1) 1494 err(1, NULL); 1495 } 1496 if (Tflag != -1) { 1497 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1498 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1499 err(1, "set IP ToS"); 1500 1501 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1502 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1503 err(1, "set IPv6 traffic class"); 1504 } 1505 if (Iflag) { 1506 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1507 &Iflag, sizeof(Iflag)) == -1) 1508 err(1, "set TCP receive buffer size"); 1509 } 1510 if (Oflag) { 1511 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1512 &Oflag, sizeof(Oflag)) == -1) 1513 err(1, "set TCP send buffer size"); 1514 } 1515 1516 if (ttl != -1) { 1517 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1518 IP_TTL, &ttl, sizeof(ttl))) 1519 err(1, "set IP TTL"); 1520 1521 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1522 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1523 err(1, "set IPv6 unicast hops"); 1524 } 1525 1526 if (minttl != -1) { 1527 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1528 IP_MINTTL, &minttl, sizeof(minttl))) 1529 err(1, "set IP min TTL"); 1530 #ifdef IPV6_MINHOPCOUNT 1531 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1532 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1533 err(1, "set IPv6 min hop count"); 1534 #endif 1535 } 1536 } 1537 1538 int 1539 map_tos(char *s, int *val) 1540 { 1541 /* DiffServ Codepoints and other TOS mappings */ 1542 const struct toskeywords { 1543 const char *keyword; 1544 int val; 1545 } *t, toskeywords[] = { 1546 { "af11", IPTOS_DSCP_AF11 }, 1547 { "af12", IPTOS_DSCP_AF12 }, 1548 { "af13", IPTOS_DSCP_AF13 }, 1549 { "af21", IPTOS_DSCP_AF21 }, 1550 { "af22", IPTOS_DSCP_AF22 }, 1551 { "af23", IPTOS_DSCP_AF23 }, 1552 { "af31", IPTOS_DSCP_AF31 }, 1553 { "af32", IPTOS_DSCP_AF32 }, 1554 { "af33", IPTOS_DSCP_AF33 }, 1555 { "af41", IPTOS_DSCP_AF41 }, 1556 { "af42", IPTOS_DSCP_AF42 }, 1557 { "af43", IPTOS_DSCP_AF43 }, 1558 { "critical", IPTOS_PREC_CRITIC_ECP }, 1559 { "cs0", IPTOS_DSCP_CS0 }, 1560 { "cs1", IPTOS_DSCP_CS1 }, 1561 { "cs2", IPTOS_DSCP_CS2 }, 1562 { "cs3", IPTOS_DSCP_CS3 }, 1563 { "cs4", IPTOS_DSCP_CS4 }, 1564 { "cs5", IPTOS_DSCP_CS5 }, 1565 { "cs6", IPTOS_DSCP_CS6 }, 1566 { "cs7", IPTOS_DSCP_CS7 }, 1567 { "ef", IPTOS_DSCP_EF }, 1568 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1569 { "lowdelay", IPTOS_LOWDELAY }, 1570 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1571 { "reliability", IPTOS_RELIABILITY }, 1572 { "throughput", IPTOS_THROUGHPUT }, 1573 { NULL, -1 }, 1574 }; 1575 1576 for (t = toskeywords; t->keyword != NULL; t++) { 1577 if (strcmp(s, t->keyword) == 0) { 1578 *val = t->val; 1579 return (1); 1580 } 1581 } 1582 1583 return (0); 1584 } 1585 1586 #ifdef CRYPTO 1587 int 1588 map_tls(char *s, int *val) 1589 { 1590 const struct tlskeywords { 1591 const char *keyword; 1592 int val; 1593 } *t, tlskeywords[] = { 1594 { "tlsall", TLS_ALL }, 1595 { "noverify", TLS_NOVERIFY }, 1596 { "noname", TLS_NONAME }, 1597 { "clientcert", TLS_CCERT}, 1598 { "muststaple", TLS_MUSTSTAPLE}, 1599 { NULL, -1 }, 1600 }; 1601 1602 for (t = tlskeywords; t->keyword != NULL; t++) { 1603 if (strcmp(s, t->keyword) == 0) { 1604 *val |= t->val; 1605 return (1); 1606 } 1607 } 1608 return (0); 1609 } 1610 1611 void 1612 report_tls(struct tls * tls_ctx, char * host, char *tlsexpectname) 1613 { 1614 time_t t; 1615 const char *ocsp_url; 1616 1617 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1618 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1619 fprintf(stderr, "Peer name: %s\n", 1620 tlsexpectname ? tlsexpectname : host); 1621 if (tls_peer_cert_subject(tls_ctx)) 1622 fprintf(stderr, "Subject: %s\n", 1623 tls_peer_cert_subject(tls_ctx)); 1624 if (tls_peer_cert_issuer(tls_ctx)) 1625 fprintf(stderr, "Issuer: %s\n", 1626 tls_peer_cert_issuer(tls_ctx)); 1627 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1628 fprintf(stderr, "Valid From: %s", ctime(&t)); 1629 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1630 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1631 if (tls_peer_cert_hash(tls_ctx)) 1632 fprintf(stderr, "Cert Hash: %s\n", 1633 tls_peer_cert_hash(tls_ctx)); 1634 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1635 if (ocsp_url != NULL) 1636 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1637 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1638 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1639 fprintf(stderr, "OCSP Stapling: %s\n", 1640 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1641 tls_peer_ocsp_result(tls_ctx)); 1642 fprintf(stderr, 1643 " response_status=%d cert_status=%d crl_reason=%d\n", 1644 tls_peer_ocsp_response_status(tls_ctx), 1645 tls_peer_ocsp_cert_status(tls_ctx), 1646 tls_peer_ocsp_crl_reason(tls_ctx)); 1647 t = tls_peer_ocsp_this_update(tls_ctx); 1648 fprintf(stderr, " this update: %s", 1649 t != -1 ? ctime(&t) : "\n"); 1650 t = tls_peer_ocsp_next_update(tls_ctx); 1651 fprintf(stderr, " next update: %s", 1652 t != -1 ? ctime(&t) : "\n"); 1653 t = tls_peer_ocsp_revocation_time(tls_ctx); 1654 fprintf(stderr, " revocation: %s", 1655 t != -1 ? ctime(&t) : "\n"); 1656 break; 1657 case -1: 1658 break; 1659 default: 1660 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1661 tls_peer_ocsp_response_status(tls_ctx), 1662 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1663 tls_peer_ocsp_result(tls_ctx)); 1664 break; 1665 1666 } 1667 } 1668 #endif 1669 1670 void 1671 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1672 { 1673 char remote_host[NI_MAXHOST]; 1674 char remote_port[NI_MAXSERV]; 1675 int herr; 1676 int flags = NI_NUMERICSERV; 1677 1678 if (path != NULL) { 1679 fprintf(stderr, "Connection on %s received!\n", path); 1680 return; 1681 } 1682 1683 if (nflag) 1684 flags |= NI_NUMERICHOST; 1685 1686 if ((herr = getnameinfo(sa, salen, 1687 remote_host, sizeof(remote_host), 1688 remote_port, sizeof(remote_port), 1689 flags)) != 0) { 1690 if (herr == EAI_SYSTEM) 1691 err(1, "getnameinfo"); 1692 else 1693 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1694 } 1695 1696 fprintf(stderr, 1697 "Connection from %s %s " 1698 "received!\n", remote_host, remote_port); 1699 } 1700 1701 void 1702 help(void) 1703 { 1704 usage(0); 1705 fprintf(stderr, "\tCommand Summary:\n" 1706 1707 "\t-4 Use IPv4\n" 1708 "\t-6 Use IPv6\n" 1709 #ifdef CRYPTO 1710 "\t-C certfile Public key file\n" 1711 "\t-c Use TLS\n" 1712 #endif 1713 "\t-D Enable the debug socket option\n" 1714 "\t-d Detach from stdin\n" 1715 #ifdef CRYPTO 1716 "\t-e name\t Required name in peer certificate\n" 1717 #endif 1718 "\t-F Pass socket fd\n" 1719 #ifdef CRYPTO 1720 "\t-H hash\t Hash string of peer certificate\n" 1721 #endif 1722 "\t-h This help text\n" 1723 "\t-I length TCP receive buffer length\n" 1724 "\t-i interval Delay interval for lines sent, ports scanned\n" 1725 #ifdef CRYPTO 1726 "\t-K keyfile Private key file\n" 1727 #endif 1728 "\t-k Keep inbound sockets open for multiple connects\n" 1729 "\t-l Listen mode, for inbound connects\n" 1730 "\t-M ttl Outgoing TTL / Hop Limit\n" 1731 "\t-m minttl Minimum incoming TTL / Hop Limit\n" 1732 "\t-N Shutdown the network socket after EOF on stdin\n" 1733 "\t-n Suppress name/port resolutions\n" 1734 "\t-O length TCP send buffer length\n" 1735 #ifdef CRYPTO 1736 "\t-o staplefile Staple file\n" 1737 #endif 1738 "\t-P proxyuser\tUsername for proxy authentication\n" 1739 "\t-p port\t Specify local port for remote connects\n" 1740 #ifdef CRYPTO 1741 "\t-R CAfile CA bundle\n" 1742 #endif 1743 "\t-r Randomize remote ports\n" 1744 "\t-S Enable the TCP MD5 signature option\n" 1745 "\t-s source Local source address\n" 1746 #ifdef CRYPTO 1747 "\t-T keyword TOS value or TLS options\n" 1748 #endif 1749 "\t-t Answer TELNET negotiation\n" 1750 "\t-U Use UNIX domain socket\n" 1751 "\t-u UDP mode\n" 1752 #ifdef __OpenBSD__ 1753 "\t-V rtable Specify alternate routing table\n" 1754 #endif 1755 "\t-v Verbose\n" 1756 "\t-w timeout Timeout for connects and final net reads\n" 1757 "\t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n" 1758 "\t-x addr[:port]\tSpecify proxy address and port\n" 1759 "\t-z Zero-I/O mode [used for scanning]\n" 1760 "Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1761 exit(1); 1762 } 1763 1764 void 1765 usage(int ret) 1766 { 1767 fprintf(stderr, 1768 "Usage: %s [-46%sDdFhklNnrStUuvz] [-e name] [-I length]\n" 1769 #ifdef CRYPTO 1770 "\t [-C certfile] [-H hash] [-K keyfile] [-R CAfile] " 1771 "[-T keyword] [-o staplefile]\n" 1772 #endif 1773 "\t [-i interval] [-M ttl] [-m minttl] [-O length]\n" 1774 "\t [-P proxy_username] [-p source_port]\n" 1775 "\t [-s source] " 1776 #ifdef __OpenBSD__ 1777 "[-V rtable] " 1778 #endif 1779 "[-w timeout] [-X proxy_protocol]\n" 1780 "\t [-x proxy_address[:port]] [destination] [port]\n", 1781 getprogname(), 1782 #ifdef CRYPTO 1783 "c" 1784 #else 1785 "" 1786 #endif 1787 ); 1788 if (ret) 1789 exit(1); 1790 } 1791