1 /* $OpenBSD: netcat.c,v 1.172 2017/02/05 01:39:14 jca Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj (at) 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 1.7 2023/06/20 08:51:24 rin Exp $"); 31 32 /* 33 * Re-written nc(1) for OpenBSD. Original implementation by 34 * *Hobbit* <hobbit (at) 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 #ifdef CRYPTO 184 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vw:X:x:z" 185 #else 186 "46Dde:FhI:i:klM:m:NnO:P:p:rSs:tUuvw:X:x:z" 187 #endif 188 )) != -1) { 189 switch (ch) { 190 case '4': 191 family = AF_INET; 192 break; 193 case '6': 194 family = AF_INET6; 195 break; 196 case 'U': 197 family = AF_UNIX; 198 break; 199 case 'X': 200 if (strcasecmp(optarg, "connect") == 0) 201 socksv = -1; /* HTTP proxy CONNECT */ 202 else if (strcmp(optarg, "4") == 0) 203 socksv = 4; /* SOCKS v.4 */ 204 else if (strcmp(optarg, "5") == 0) 205 socksv = 5; /* SOCKS v.5 */ 206 else 207 errx(1, "unsupported proxy protocol"); 208 break; 209 #ifdef CRYPTO 210 case 'C': 211 Cflag = optarg; 212 break; 213 case 'c': 214 usetls = 1; 215 break; 216 #endif 217 case 'd': 218 dflag = 1; 219 break; 220 case 'e': 221 tls_expectname = optarg; 222 break; 223 case 'F': 224 Fflag = 1; 225 break; 226 #ifdef CRYPTO 227 case 'H': 228 tls_expecthash = optarg; 229 break; 230 #endif 231 case 'h': 232 help(); 233 break; 234 case 'i': 235 iflag = strtoi(optarg, NULL, 0, 0, UINT_MAX, &errnum); 236 if (errnum) 237 errc(1, errnum, "bad interval `%s'", optarg); 238 break; 239 #ifdef CRYPTO 240 case 'K': 241 Kflag = optarg; 242 break; 243 #endif 244 case 'k': 245 kflag = 1; 246 break; 247 case 'l': 248 lflag = 1; 249 break; 250 case 'M': 251 ttl = strtoi(optarg, NULL, 0, 0, 255, &errnum); 252 if (errnum) 253 errc(1, errnum, "bad ttl `%s'", optarg); 254 break; 255 case 'm': 256 minttl = strtoi(optarg, NULL, 0, 0, 255, &errnum); 257 if (errnum) 258 errc(1, errnum, "bad minttl `%s'", optarg); 259 break; 260 case 'N': 261 Nflag = 1; 262 break; 263 case 'n': 264 nflag = 1; 265 break; 266 case 'P': 267 Pflag = optarg; 268 break; 269 case 'p': 270 pflag = optarg; 271 break; 272 #ifdef CRYPTO 273 case 'R': 274 tls_cachanged = 1; 275 Rflag = optarg; 276 break; 277 #endif 278 case 'r': 279 rflag = 1; 280 break; 281 case 's': 282 sflag = optarg; 283 break; 284 case 't': 285 tflag = 1; 286 break; 287 case 'u': 288 uflag = 1; 289 break; 290 #ifdef __OpenBSD__ 291 case 'V': 292 rtableid = (int)strtoi(optarg, NULL, 0, 0, 255, &errnum); 293 if (errnum) 294 errc(1, errnum, "bad rtable `%s'", optarg); 295 break; 296 #endif 297 case 'v': 298 vflag = 1; 299 break; 300 case 'w': 301 timeout = strtoi(optarg, NULL, 0, 0, INT_MAX / 1000, &errnum); 302 if (errnum) 303 errc(1, errnum, "bad timeout `%s'", optarg); 304 timeout *= 1000; 305 break; 306 case 'x': 307 xflag = 1; 308 if ((proxy = strdup(optarg)) == NULL) 309 err(1, NULL); 310 break; 311 case 'z': 312 zflag = 1; 313 break; 314 case 'D': 315 Dflag = 1; 316 break; 317 case 'I': 318 Iflag = strtoi(optarg, NULL, 0, 1, 65536 << 14, &errnum); 319 if (errnum) 320 errc(1, errnum, "bad TCP receive window `%s'", 321 optarg); 322 break; 323 case 'O': 324 Oflag = strtoi(optarg, NULL, 0, 1, 65536 << 14, &errnum); 325 if (errnum) 326 errc(1, errnum, "bad TCP send window `%s'", 327 optarg); 328 break; 329 #ifdef CRYPTO 330 case 'o': 331 oflag = optarg; 332 break; 333 #endif 334 case 'S': 335 Sflag = 1; 336 break; 337 #ifdef CRYPTO 338 case 'T': 339 if (map_tos(optarg, &Tflag)) 340 break; 341 if (map_tls(optarg, &TLSopt)) 342 break; 343 Tflag = (int)strtoi(optarg, NULL, 0, 0, 255, &errnum); 344 if (errnum) 345 errc(1, errnum, "illegal tos/tls value `%s'", 346 optarg); 347 break; 348 #endif 349 default: 350 usage(1); 351 } 352 } 353 argc -= optind; 354 argv += optind; 355 356 #ifdef __OpenBSD__ 357 if (rtableid >= 0) 358 if (setrtable(rtableid) == -1) 359 err(1, "setrtable"); 360 361 if (family == AF_UNIX) { 362 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 363 err(1, "pledge"); 364 } else if (Fflag) { 365 if (Pflag) { 366 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 367 err(1, "pledge"); 368 } else if (pledge("stdio inet dns sendfd", NULL) == -1) 369 err(1, "pledge"); 370 } else if (Pflag) { 371 if (pledge("stdio inet dns tty", NULL) == -1) 372 err(1, "pledge"); 373 } else if (usetls) { 374 if (pledge("stdio rpath inet dns", NULL) == -1) 375 err(1, "pledge"); 376 } else if (pledge("stdio inet dns", NULL) == -1) 377 err(1, "pledge"); 378 #endif 379 380 /* Cruft to make sure options are clean, and used properly. */ 381 if (argv[0] && !argv[1] && family == AF_UNIX) { 382 host = argv[0]; 383 uport = NULL; 384 } else if (argv[0] && !argv[1]) { 385 if (!lflag) 386 usage(1); 387 uport = argv[0]; 388 host = NULL; 389 } else if (argv[0] && argv[1]) { 390 host = argv[0]; 391 uport = argv[1]; 392 } else 393 usage(1); 394 395 if (lflag && sflag) 396 errx(1, "cannot use -s and -l"); 397 if (lflag && pflag) 398 errx(1, "cannot use -p and -l"); 399 if (lflag && zflag) 400 errx(1, "cannot use -z and -l"); 401 if (!lflag && kflag) 402 errx(1, "must use -l with -k"); 403 if (uflag && usetls) 404 errx(1, "cannot use -c and -u"); 405 if ((family == AF_UNIX) && usetls) 406 errx(1, "cannot use -c and -U"); 407 if ((family == AF_UNIX) && Fflag) 408 errx(1, "cannot use -F and -U"); 409 if (Fflag && usetls) 410 errx(1, "cannot use -c and -F"); 411 #ifdef CRYPTO 412 if (TLSopt && !usetls) 413 errx(1, "you must specify -c to use TLS options"); 414 if (Cflag && !usetls) 415 errx(1, "you must specify -c to use -C"); 416 if (Kflag && !usetls) 417 errx(1, "you must specify -c to use -K"); 418 if (oflag && !Cflag) 419 errx(1, "you must specify -C to use -o"); 420 if (tls_cachanged && !usetls) 421 errx(1, "you must specify -c to use -R"); 422 if (tls_expecthash && !usetls) 423 errx(1, "you must specify -c to use -H"); 424 if (tls_expectname && !usetls) 425 errx(1, "you must specify -c to use -e"); 426 #endif 427 428 /* Get name of temporary socket for unix datagram client */ 429 if ((family == AF_UNIX) && uflag && !lflag) { 430 if (sflag) { 431 unix_dg_tmp_socket = sflag; 432 } else { 433 int fd; 434 snprintf(unix_dg_tmp_socket_buf, 435 sizeof(unix_dg_tmp_socket_buf), 436 "/tmp/%s.XXXXXXXXXX", getprogname()); 437 /* XXX: abstract sockets instead? */ 438 if ((fd = mkstemp(unix_dg_tmp_socket_buf)) == -1) 439 err(1, "mktemp"); 440 close(fd); 441 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 442 } 443 } 444 445 /* Initialize addrinfo structure. */ 446 if (family != AF_UNIX) { 447 memset(&hints, 0, sizeof(struct addrinfo)); 448 hints.ai_family = family; 449 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 450 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 451 if (nflag) 452 hints.ai_flags |= AI_NUMERICHOST; 453 } 454 455 if (xflag) { 456 if (uflag) 457 errx(1, "no proxy support for UDP mode"); 458 459 if (lflag) 460 errx(1, "no proxy support for listen"); 461 462 if (family == AF_UNIX) 463 errx(1, "no proxy support for unix sockets"); 464 465 if (sflag) 466 errx(1, "no proxy support for local source address"); 467 468 if (*proxy == '[') { 469 ++proxy; 470 proxyport = strchr(proxy, ']'); 471 if (proxyport == NULL) 472 errx(1, "missing closing bracket in proxy"); 473 *proxyport++ = '\0'; 474 if (*proxyport == '\0') 475 /* Use default proxy port. */ 476 proxyport = NULL; 477 else { 478 if (*proxyport == ':') 479 ++proxyport; 480 else 481 errx(1, "garbage proxy port delimiter"); 482 } 483 } else { 484 proxyport = strrchr(proxy, ':'); 485 if (proxyport != NULL) 486 *proxyport++ = '\0'; 487 } 488 489 memset(&proxyhints, 0, sizeof(struct addrinfo)); 490 proxyhints.ai_family = family; 491 proxyhints.ai_socktype = SOCK_STREAM; 492 proxyhints.ai_protocol = IPPROTO_TCP; 493 if (nflag) 494 proxyhints.ai_flags |= AI_NUMERICHOST; 495 } 496 497 #ifdef CRYPTO 498 if (usetls) { 499 #if __OpenBSD__ 500 if (Pflag) { 501 if (pledge("stdio inet dns tty rpath", NULL) == -1) 502 err(1, "pledge"); 503 } else if (pledge("stdio inet dns rpath", NULL) == -1) 504 err(1, "pledge"); 505 #endif 506 507 if (tls_init() == -1) 508 errx(1, "unable to initialize TLS"); 509 if ((tls_cfg = tls_config_new()) == NULL) 510 errx(1, "unable to allocate TLS config"); 511 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 512 errx(1, "%s", tls_config_error(tls_cfg)); 513 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 514 errx(1, "%s", tls_config_error(tls_cfg)); 515 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 516 errx(1, "%s", tls_config_error(tls_cfg)); 517 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 518 errx(1, "%s", tls_config_error(tls_cfg)); 519 if (TLSopt & TLS_ALL) { 520 if (tls_config_set_protocols(tls_cfg, 521 TLS_PROTOCOLS_ALL) != 0) 522 errx(1, "%s", tls_config_error(tls_cfg)); 523 if (tls_config_set_ciphers(tls_cfg, "all") != 0) 524 errx(1, "%s", tls_config_error(tls_cfg)); 525 } 526 if (!lflag && (TLSopt & TLS_CCERT)) 527 errx(1, "clientcert is only valid with -l"); 528 if (TLSopt & TLS_NONAME) 529 tls_config_insecure_noverifyname(tls_cfg); 530 if (TLSopt & TLS_NOVERIFY) { 531 if (tls_expecthash != NULL) 532 errx(1, "-H and -T noverify may not be used" 533 "together"); 534 tls_config_insecure_noverifycert(tls_cfg); 535 } 536 if (TLSopt & TLS_MUSTSTAPLE) 537 tls_config_ocsp_require_stapling(tls_cfg); 538 539 #ifdef __OpenBSD__ 540 if (Pflag) { 541 if (pledge("stdio inet dns tty", NULL) == -1) 542 err(1, "pledge"); 543 } else if (pledge("stdio inet dns", NULL) == -1) 544 err(1, "pledge"); 545 #endif 546 } 547 #endif 548 if (lflag) { 549 #ifdef CRYPTO 550 struct tls *tls_cctx = NULL; 551 #endif 552 int connfd; 553 ret = 0; 554 555 if (family == AF_UNIX) { 556 if (uflag) 557 s = unix_bind(host, 0); 558 else 559 s = unix_listen(host); 560 } 561 562 #ifdef CRYPTO 563 if (usetls) { 564 tls_config_verify_client_optional(tls_cfg); 565 if ((tls_ctx = tls_server()) == NULL) 566 errx(1, "tls server creation failed"); 567 if (tls_configure(tls_ctx, tls_cfg) == -1) 568 errx(1, "tls configuration failed (%s)", 569 tls_error(tls_ctx)); 570 } 571 #endif 572 /* Allow only one connection at a time, but stay alive. */ 573 for (;;) { 574 if (family != AF_UNIX) 575 s = local_listen(host, uport, hints); 576 if (s < 0) 577 err(1, NULL); 578 /* 579 * For UDP and -k, don't connect the socket, let it 580 * receive datagrams from multiple socket pairs. 581 */ 582 if (uflag && kflag) 583 readwrite(s, NULL); 584 /* 585 * For UDP and not -k, we will use recvfrom() initially 586 * to wait for a caller, then use the regular functions 587 * to talk to the caller. 588 */ 589 else if (uflag && !kflag) { 590 int rv, plen; 591 char buf[16384]; 592 struct sockaddr_storage z; 593 594 len = sizeof(z); 595 plen = 2048; 596 rv = recvfrom(s, buf, plen, MSG_PEEK, 597 (struct sockaddr *)&z, &len); 598 if (rv < 0) 599 err(1, "recvfrom"); 600 601 rv = connect(s, (struct sockaddr *)&z, len); 602 if (rv < 0) 603 err(1, "connect"); 604 605 if (vflag) 606 report_connect((struct sockaddr *)&z, len, NULL); 607 608 readwrite(s, NULL); 609 } else { 610 len = sizeof(cliaddr); 611 connfd = accept4(s, (struct sockaddr *)&cliaddr, 612 &len, SOCK_NONBLOCK); 613 if (connfd == -1) { 614 /* For now, all errnos are fatal */ 615 err(1, "accept"); 616 } 617 if (vflag) 618 report_connect((struct sockaddr *)&cliaddr, len, 619 family == AF_UNIX ? host : NULL); 620 #ifdef CRYPTO 621 if ((usetls) && 622 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 623 readwrite(connfd, tls_cctx); 624 if (!usetls) 625 #endif 626 readwrite(connfd, NULL); 627 #ifdef CRYPTO 628 if (tls_cctx) { 629 int i; 630 631 do { 632 i = tls_close(tls_cctx); 633 } while (i == TLS_WANT_POLLIN || 634 i == TLS_WANT_POLLOUT); 635 tls_free(tls_cctx); 636 tls_cctx = NULL; 637 } 638 #endif 639 close(connfd); 640 } 641 if (family != AF_UNIX) 642 close(s); 643 else if (uflag) { 644 if (connect(s, NULL, 0) < 0) 645 err(1, "connect"); 646 } 647 648 if (!kflag) 649 break; 650 } 651 } else if (family == AF_UNIX) { 652 ret = 0; 653 654 if ((s = unix_connect(host)) > 0 && !zflag) { 655 readwrite(s, NULL); 656 close(s); 657 } else 658 ret = 1; 659 660 if (uflag) 661 unlink(unix_dg_tmp_socket); 662 exit(ret); 663 664 } else { 665 int i = 0; 666 667 /* Construct the portlist[] array. */ 668 build_ports(uport); 669 670 /* Cycle through portlist, connecting to each port. */ 671 for (s = -1, i = 0; portlist[i] != NULL; i++) { 672 if (s != -1) 673 close(s); 674 675 #ifdef CRYPTO 676 if (usetls) { 677 if ((tls_ctx = tls_client()) == NULL) 678 errx(1, "tls client creation failed"); 679 if (tls_configure(tls_ctx, tls_cfg) == -1) 680 errx(1, "tls configuration failed (%s)", 681 tls_error(tls_ctx)); 682 } 683 #endif 684 if (xflag) 685 s = socks_connect(host, portlist[i], hints, 686 proxy, proxyport, proxyhints, socksv, 687 Pflag); 688 else 689 s = remote_connect(host, portlist[i], hints); 690 691 if (s == -1) 692 continue; 693 694 ret = 0; 695 if (vflag || zflag) { 696 /* For UDP, make sure we are connected. */ 697 if (uflag) { 698 if (udptest(s) == -1) { 699 ret = 1; 700 continue; 701 } 702 } 703 704 /* Don't look up port if -n. */ 705 if (nflag) 706 sv = NULL; 707 else { 708 sv = getservbyport( 709 ntohs(atoi(portlist[i])), 710 uflag ? "udp" : "tcp"); 711 } 712 713 fprintf(stderr, 714 "Connection to %s %s port [%s/%s] " 715 "succeeded!\n", host, portlist[i], 716 uflag ? "udp" : "tcp", 717 sv ? sv->s_name : "*"); 718 } 719 if (Fflag) 720 fdpass(s); 721 else { 722 #ifdef CRYPTO 723 if (usetls) 724 tls_setup_client(tls_ctx, s, host); 725 if (!zflag) 726 readwrite(s, tls_ctx); 727 if (tls_ctx) { 728 int j; 729 730 do { 731 j = tls_close(tls_ctx); 732 } while (j == TLS_WANT_POLLIN || 733 j == TLS_WANT_POLLOUT); 734 tls_free(tls_ctx); 735 tls_ctx = NULL; 736 } 737 #else 738 if (!zflag) 739 readwrite(s, NULL); 740 #endif 741 } 742 } 743 } 744 745 if (s != -1) 746 close(s); 747 748 #ifdef CRYPTO 749 tls_config_free(tls_cfg); 750 #endif 751 752 exit(ret); 753 } 754 755 /* 756 * unix_bind() 757 * Returns a unix socket bound to the given path 758 */ 759 int 760 unix_bind(char *path, int flags) 761 { 762 struct sockaddr_un s_un; 763 int s, save_errno; 764 765 /* Create unix domain socket. */ 766 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 767 0)) < 0) 768 return (-1); 769 770 memset(&s_un, 0, sizeof(struct sockaddr_un)); 771 s_un.sun_family = AF_UNIX; 772 773 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 774 sizeof(s_un.sun_path)) { 775 close(s); 776 errno = ENAMETOOLONG; 777 return (-1); 778 } 779 780 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 781 save_errno = errno; 782 close(s); 783 errno = save_errno; 784 return (-1); 785 } 786 return (s); 787 } 788 789 #ifdef CRYPTO 790 void 791 tls_setup_client(struct tls *tls_ctx, int s, char *host) 792 { 793 int i; 794 795 if (tls_connect_socket(tls_ctx, s, 796 tls_expectname ? tls_expectname : host) == -1) { 797 errx(1, "tls connection failed (%s)", 798 tls_error(tls_ctx)); 799 } 800 do { 801 if ((i = tls_handshake(tls_ctx)) == -1) 802 errx(1, "tls handshake failed (%s)", 803 tls_error(tls_ctx)); 804 } while (i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 805 if (vflag) 806 report_tls(tls_ctx, host, tls_expectname); 807 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 808 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 809 errx(1, "peer certificate is not %s", tls_expecthash); 810 } 811 812 struct tls * 813 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 814 { 815 struct tls *tls_cctx; 816 817 if (tls_accept_socket(tls_ctx, &tls_cctx, 818 connfd) == -1) { 819 warnx("tls accept failed (%s)", 820 tls_error(tls_ctx)); 821 tls_cctx = NULL; 822 } else { 823 int i; 824 825 do { 826 if ((i = tls_handshake(tls_cctx)) == -1) 827 warnx("tls handshake failed (%s)", 828 tls_error(tls_cctx)); 829 } while(i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 830 } 831 if (tls_cctx) { 832 int gotcert = tls_peer_cert_provided(tls_cctx); 833 834 if (vflag && gotcert) 835 report_tls(tls_cctx, host, tls_expectname); 836 if ((TLSopt & TLS_CCERT) && !gotcert) 837 warnx("No client certificate provided"); 838 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 839 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 840 warnx("peer certificate is not %s", tls_expecthash); 841 else if (gotcert && tls_expectname && 842 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 843 warnx("name (%s) not found in client cert", 844 tls_expectname); 845 else { 846 return tls_cctx; 847 } 848 } 849 return NULL; 850 } 851 #endif 852 853 /* 854 * unix_connect() 855 * Returns a socket connected to a local unix socket. Returns -1 on failure. 856 */ 857 int 858 unix_connect(char *path) 859 { 860 struct sockaddr_un s_un; 861 int s, save_errno; 862 863 if (uflag) { 864 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 865 return (-1); 866 } else { 867 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 868 return (-1); 869 } 870 871 memset(&s_un, 0, sizeof(struct sockaddr_un)); 872 s_un.sun_family = AF_UNIX; 873 874 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 875 sizeof(s_un.sun_path)) { 876 close(s); 877 errno = ENAMETOOLONG; 878 return (-1); 879 } 880 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 881 save_errno = errno; 882 close(s); 883 errno = save_errno; 884 return (-1); 885 } 886 return (s); 887 888 } 889 890 /* 891 * unix_listen() 892 * Create a unix domain socket, and listen on it. 893 */ 894 int 895 unix_listen(char *path) 896 { 897 int s; 898 if ((s = unix_bind(path, 0)) < 0) 899 return (-1); 900 901 if (listen(s, 5) < 0) { 902 close(s); 903 return (-1); 904 } 905 return (s); 906 } 907 908 /* 909 * remote_connect() 910 * Returns a socket connected to a remote host. Properly binds to a local 911 * port or source address if needed. Returns -1 on failure. 912 */ 913 int 914 remote_connect(const char *host, const char *port, struct addrinfo hints) 915 { 916 struct addrinfo *res, *res0; 917 int s = -1, error, save_errno; 918 #ifdef SO_BINDANY 919 int on = 1; 920 #endif 921 922 if ((error = getaddrinfo(host, port, &hints, &res0))) 923 errx(1, "getaddrinfo: %s", gai_strerror(error)); 924 925 for (res = res0; res; res = res->ai_next) { 926 if ((s = socket(res->ai_family, res->ai_socktype | 927 SOCK_NONBLOCK, res->ai_protocol)) < 0) 928 continue; 929 930 /* Bind to a local port or source address if specified. */ 931 if (sflag || pflag) { 932 struct addrinfo ahints, *ares; 933 934 #ifdef SO_BINDANY 935 /* try SO_BINDANY, but don't insist */ 936 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 937 #endif 938 memset(&ahints, 0, sizeof(struct addrinfo)); 939 ahints.ai_family = res->ai_family; 940 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 941 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 942 ahints.ai_flags = AI_PASSIVE; 943 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 944 errx(1, "getaddrinfo: %s", gai_strerror(error)); 945 946 if (bind(s, (struct sockaddr *)ares->ai_addr, 947 ares->ai_addrlen) < 0) 948 err(1, "bind failed"); 949 freeaddrinfo(ares); 950 } 951 952 set_common_sockopts(s, res->ai_family); 953 954 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 955 break; 956 if (vflag) 957 warn("connect to %s port %s (%s) failed", host, port, 958 uflag ? "udp" : "tcp"); 959 960 save_errno = errno; 961 close(s); 962 errno = save_errno; 963 s = -1; 964 } 965 966 freeaddrinfo(res0); 967 968 return (s); 969 } 970 971 int 972 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 973 { 974 struct pollfd pfd; 975 socklen_t optlen; 976 int optval; 977 int ret; 978 979 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 980 pfd.fd = s; 981 pfd.events = POLLOUT; 982 if ((ret = poll(&pfd, 1, timeout)) == 1) { 983 optlen = sizeof(optval); 984 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 985 &optval, &optlen)) == 0) { 986 errno = optval; 987 ret = optval == 0 ? 0 : -1; 988 } 989 } else if (ret == 0) { 990 errno = ETIMEDOUT; 991 ret = -1; 992 } else 993 err(1, "poll failed"); 994 } 995 996 return (ret); 997 } 998 999 /* 1000 * local_listen() 1001 * Returns a socket listening on a local port, binds to specified source 1002 * address. Returns -1 on failure. 1003 */ 1004 int 1005 local_listen(char *host, char *port, struct addrinfo hints) 1006 { 1007 struct addrinfo *res, *res0; 1008 int s = -1, ret, x = 1, save_errno; 1009 int error; 1010 1011 /* Allow nodename to be null. */ 1012 hints.ai_flags |= AI_PASSIVE; 1013 1014 /* 1015 * In the case of binding to a wildcard address 1016 * default to binding to an ipv4 address. 1017 */ 1018 if (host == NULL && hints.ai_family == AF_UNSPEC) 1019 hints.ai_family = AF_INET; 1020 1021 if ((error = getaddrinfo(host, port, &hints, &res0))) 1022 errx(1, "getaddrinfo: %s", gai_strerror(error)); 1023 1024 for (res = res0; res; res = res->ai_next) { 1025 if ((s = socket(res->ai_family, res->ai_socktype, 1026 res->ai_protocol)) < 0) 1027 continue; 1028 1029 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 1030 if (ret == -1) 1031 err(1, NULL); 1032 1033 set_common_sockopts(s, res->ai_family); 1034 1035 if (bind(s, (struct sockaddr *)res->ai_addr, 1036 res->ai_addrlen) == 0) 1037 break; 1038 1039 save_errno = errno; 1040 close(s); 1041 errno = save_errno; 1042 s = -1; 1043 } 1044 1045 if (!uflag && s != -1) { 1046 if (listen(s, 1) < 0) 1047 err(1, "listen"); 1048 } 1049 1050 freeaddrinfo(res0); 1051 1052 return (s); 1053 } 1054 1055 /* 1056 * readwrite() 1057 * Loop that polls on the network file descriptor and stdin. 1058 */ 1059 void 1060 readwrite(int net_fd, struct tls *tls_ctx) 1061 { 1062 struct pollfd pfd[4]; 1063 int stdin_fd = STDIN_FILENO; 1064 int stdout_fd = STDOUT_FILENO; 1065 unsigned char netinbuf[BUFSIZE]; 1066 size_t netinbufpos = 0; 1067 unsigned char stdinbuf[BUFSIZE]; 1068 size_t stdinbufpos = 0; 1069 int n, num_fds; 1070 ssize_t ret; 1071 1072 /* don't read from stdin if requested */ 1073 if (dflag) 1074 stdin_fd = -1; 1075 1076 /* stdin */ 1077 pfd[POLL_STDIN].fd = stdin_fd; 1078 pfd[POLL_STDIN].events = POLLIN; 1079 1080 /* network out */ 1081 pfd[POLL_NETOUT].fd = net_fd; 1082 pfd[POLL_NETOUT].events = 0; 1083 1084 /* network in */ 1085 pfd[POLL_NETIN].fd = net_fd; 1086 pfd[POLL_NETIN].events = POLLIN; 1087 1088 /* stdout */ 1089 pfd[POLL_STDOUT].fd = stdout_fd; 1090 pfd[POLL_STDOUT].events = 0; 1091 1092 while (1) { 1093 /* both inputs are gone, buffers are empty, we are done */ 1094 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1095 stdinbufpos == 0 && netinbufpos == 0) { 1096 close(net_fd); 1097 return; 1098 } 1099 /* both outputs are gone, we can't continue */ 1100 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 1101 close(net_fd); 1102 return; 1103 } 1104 /* listen and net in gone, queues empty, done */ 1105 if (lflag && pfd[POLL_NETIN].fd == -1 && 1106 stdinbufpos == 0 && netinbufpos == 0) { 1107 close(net_fd); 1108 return; 1109 } 1110 1111 /* help says -i is for "wait between lines sent". We read and 1112 * write arbitrary amounts of data, and we don't want to start 1113 * scanning for newlines, so this is as good as it gets */ 1114 if (iflag) 1115 sleep(iflag); 1116 1117 /* poll */ 1118 num_fds = poll(pfd, 4, timeout); 1119 1120 /* treat poll errors */ 1121 if (num_fds == -1) { 1122 close(net_fd); 1123 err(1, "polling error"); 1124 } 1125 1126 /* timeout happened */ 1127 if (num_fds == 0) 1128 return; 1129 1130 /* treat socket error conditions */ 1131 for (n = 0; n < 4; n++) { 1132 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1133 pfd[n].fd = -1; 1134 } 1135 } 1136 /* reading is possible after HUP */ 1137 if (pfd[POLL_STDIN].events & POLLIN && 1138 pfd[POLL_STDIN].revents & POLLHUP && 1139 !(pfd[POLL_STDIN].revents & POLLIN)) 1140 pfd[POLL_STDIN].fd = -1; 1141 1142 if (pfd[POLL_NETIN].events & POLLIN && 1143 pfd[POLL_NETIN].revents & POLLHUP && 1144 !(pfd[POLL_NETIN].revents & POLLIN)) 1145 pfd[POLL_NETIN].fd = -1; 1146 1147 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1148 if (Nflag) 1149 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1150 pfd[POLL_NETOUT].fd = -1; 1151 } 1152 /* if HUP, stop watching stdout */ 1153 if (pfd[POLL_STDOUT].revents & POLLHUP) 1154 pfd[POLL_STDOUT].fd = -1; 1155 /* if no net out, stop watching stdin */ 1156 if (pfd[POLL_NETOUT].fd == -1) 1157 pfd[POLL_STDIN].fd = -1; 1158 /* if no stdout, stop watching net in */ 1159 if (pfd[POLL_STDOUT].fd == -1) { 1160 if (pfd[POLL_NETIN].fd != -1) 1161 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1162 pfd[POLL_NETIN].fd = -1; 1163 } 1164 1165 /* try to read from stdin */ 1166 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1167 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1168 &stdinbufpos, NULL); 1169 if (ret == TLS_WANT_POLLIN) 1170 pfd[POLL_STDIN].events = POLLIN; 1171 else if (ret == TLS_WANT_POLLOUT) 1172 pfd[POLL_STDIN].events = POLLOUT; 1173 else if (ret == 0 || ret == -1) 1174 pfd[POLL_STDIN].fd = -1; 1175 /* read something - poll net out */ 1176 if (stdinbufpos > 0) 1177 pfd[POLL_NETOUT].events = POLLOUT; 1178 /* filled buffer - remove self from polling */ 1179 if (stdinbufpos == BUFSIZE) 1180 pfd[POLL_STDIN].events = 0; 1181 } 1182 /* try to write to network */ 1183 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1184 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1185 &stdinbufpos, tls_ctx); 1186 if (ret == TLS_WANT_POLLIN) 1187 pfd[POLL_NETOUT].events = POLLIN; 1188 else if (ret == TLS_WANT_POLLOUT) 1189 pfd[POLL_NETOUT].events = POLLOUT; 1190 else if (ret == -1) 1191 pfd[POLL_NETOUT].fd = -1; 1192 /* buffer empty - remove self from polling */ 1193 if (stdinbufpos == 0) 1194 pfd[POLL_NETOUT].events = 0; 1195 /* buffer no longer full - poll stdin again */ 1196 if (stdinbufpos < BUFSIZE) 1197 pfd[POLL_STDIN].events = POLLIN; 1198 } 1199 /* try to read from network */ 1200 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1201 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1202 &netinbufpos, tls_ctx); 1203 if (ret == TLS_WANT_POLLIN) 1204 pfd[POLL_NETIN].events = POLLIN; 1205 else if (ret == TLS_WANT_POLLOUT) 1206 pfd[POLL_NETIN].events = POLLOUT; 1207 else if (ret == -1) 1208 pfd[POLL_NETIN].fd = -1; 1209 /* eof on net in - remove from pfd */ 1210 if (ret == 0) { 1211 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1212 pfd[POLL_NETIN].fd = -1; 1213 } 1214 /* read something - poll stdout */ 1215 if (netinbufpos > 0) 1216 pfd[POLL_STDOUT].events = POLLOUT; 1217 /* filled buffer - remove self from polling */ 1218 if (netinbufpos == BUFSIZE) 1219 pfd[POLL_NETIN].events = 0; 1220 /* handle telnet */ 1221 if (tflag) 1222 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1223 netinbufpos); 1224 } 1225 /* try to write to stdout */ 1226 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1227 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1228 &netinbufpos, NULL); 1229 if (ret == TLS_WANT_POLLIN) 1230 pfd[POLL_STDOUT].events = POLLIN; 1231 else if (ret == TLS_WANT_POLLOUT) 1232 pfd[POLL_STDOUT].events = POLLOUT; 1233 else if (ret == -1) 1234 pfd[POLL_STDOUT].fd = -1; 1235 /* buffer empty - remove self from polling */ 1236 if (netinbufpos == 0) 1237 pfd[POLL_STDOUT].events = 0; 1238 /* buffer no longer full - poll net in again */ 1239 if (netinbufpos < BUFSIZE) 1240 pfd[POLL_NETIN].events = POLLIN; 1241 } 1242 1243 /* stdin gone and queue empty? */ 1244 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1245 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1246 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1247 pfd[POLL_NETOUT].fd = -1; 1248 } 1249 /* net in gone and queue empty? */ 1250 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1251 pfd[POLL_STDOUT].fd = -1; 1252 } 1253 } 1254 } 1255 1256 ssize_t 1257 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1258 { 1259 ssize_t n; 1260 ssize_t adjust; 1261 1262 #ifdef CRYPTO 1263 if (tls) 1264 n = tls_write(tls, buf, *bufpos); 1265 else 1266 #endif 1267 { 1268 n = write(fd, buf, *bufpos); 1269 /* don't treat EAGAIN, EINTR as error */ 1270 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1271 n = TLS_WANT_POLLOUT; 1272 } 1273 if (n <= 0) 1274 return n; 1275 /* adjust buffer */ 1276 adjust = *bufpos - n; 1277 if (adjust > 0) 1278 memmove(buf, buf + n, adjust); 1279 *bufpos -= n; 1280 return n; 1281 } 1282 1283 ssize_t 1284 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1285 { 1286 size_t num = BUFSIZE - *bufpos; 1287 ssize_t n; 1288 1289 #ifdef CRYPTO 1290 if (tls) 1291 n = tls_read(tls, buf + *bufpos, num); 1292 else 1293 #endif 1294 { 1295 1296 n = read(fd, buf + *bufpos, num); 1297 /* don't treat EAGAIN, EINTR as error */ 1298 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1299 n = TLS_WANT_POLLIN; 1300 } 1301 if (n <= 0) 1302 return n; 1303 *bufpos += n; 1304 return n; 1305 } 1306 1307 /* 1308 * fdpass() 1309 * Pass the connected file descriptor to stdout and exit. 1310 */ 1311 void 1312 fdpass(int nfd) 1313 { 1314 struct msghdr mh; 1315 union { 1316 struct cmsghdr hdr; 1317 char buf[CMSG_SPACE(sizeof(int))]; 1318 } cmsgbuf; 1319 struct cmsghdr *cmsg; 1320 struct iovec iov; 1321 char c = '\0'; 1322 ssize_t r; 1323 struct pollfd pfd; 1324 1325 /* Avoid obvious stupidity */ 1326 if (isatty(STDOUT_FILENO)) 1327 errx(1, "Cannot pass file descriptor to tty"); 1328 1329 bzero(&mh, sizeof(mh)); 1330 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1331 bzero(&iov, sizeof(iov)); 1332 1333 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1334 mh.msg_controllen = sizeof(cmsgbuf.buf); 1335 cmsg = CMSG_FIRSTHDR(&mh); 1336 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1337 cmsg->cmsg_level = SOL_SOCKET; 1338 cmsg->cmsg_type = SCM_RIGHTS; 1339 *(int *)CMSG_DATA(cmsg) = nfd; 1340 1341 iov.iov_base = &c; 1342 iov.iov_len = 1; 1343 mh.msg_iov = &iov; 1344 mh.msg_iovlen = 1; 1345 1346 bzero(&pfd, sizeof(pfd)); 1347 pfd.fd = STDOUT_FILENO; 1348 pfd.events = POLLOUT; 1349 for (;;) { 1350 r = sendmsg(STDOUT_FILENO, &mh, 0); 1351 if (r == -1) { 1352 if (errno == EAGAIN || errno == EINTR) { 1353 if (poll(&pfd, 1, -1) == -1) 1354 err(1, "poll"); 1355 continue; 1356 } 1357 err(1, "sendmsg"); 1358 } else if (r != 1) 1359 errx(1, "sendmsg: unexpected return value %zd", r); 1360 else 1361 break; 1362 } 1363 exit(0); 1364 } 1365 1366 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1367 void 1368 atelnet(int nfd, unsigned char *buf, unsigned int size) 1369 { 1370 unsigned char *p, *end; 1371 unsigned char obuf[4]; 1372 1373 if (size < 3) 1374 return; 1375 end = buf + size - 2; 1376 1377 for (p = buf; p < end; p++) { 1378 if (*p != IAC) 1379 continue; 1380 1381 obuf[0] = IAC; 1382 p++; 1383 if ((*p == WILL) || (*p == WONT)) 1384 obuf[1] = DONT; 1385 else if ((*p == DO) || (*p == DONT)) 1386 obuf[1] = WONT; 1387 else 1388 continue; 1389 1390 p++; 1391 obuf[2] = *p; 1392 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1393 warn("Write Error!"); 1394 } 1395 } 1396 1397 1398 static int 1399 strtoport(const char *portstr, int udp) 1400 { 1401 struct servent *entry; 1402 int errnum; 1403 const char *proto; 1404 int port; 1405 1406 proto = udp ? "udp" : "tcp"; 1407 1408 port = strtoi(portstr, NULL, 0, 1, PORT_MAX, &errnum); 1409 if (errnum == 0) 1410 return port; 1411 if ((entry = getservbyname(portstr, proto)) == NULL) 1412 errx(1, "service \"%s\" unknown", portstr); 1413 return ntohs(entry->s_port); 1414 } 1415 1416 /* 1417 * build_ports() 1418 * Build an array of ports in portlist[], listing each port 1419 * that we should try to connect to. 1420 */ 1421 void 1422 build_ports(char *p) 1423 { 1424 char *n; 1425 int hi, lo, cp; 1426 int x = 0; 1427 1428 if ((n = strchr(p, '-')) != NULL) { 1429 *n = '\0'; 1430 n++; 1431 1432 /* Make sure the ports are in order: lowest->highest. */ 1433 hi = strtoport(n, uflag); 1434 lo = strtoport(p, uflag); 1435 if (lo > hi) { 1436 cp = hi; 1437 hi = lo; 1438 lo = cp; 1439 } 1440 1441 /* 1442 * Initialize portlist with a random permutation. Based on 1443 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1444 */ 1445 if (rflag) { 1446 for (x = 0; x <= hi - lo; x++) { 1447 cp = arc4random_uniform(x + 1); 1448 portlist[x] = portlist[cp]; 1449 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1450 err(1, "asprintf"); 1451 } 1452 } else { /* Load ports sequentially. */ 1453 for (cp = lo; cp <= hi; cp++) { 1454 if (asprintf(&portlist[x], "%d", cp) < 0) 1455 err(1, "asprintf"); 1456 x++; 1457 } 1458 } 1459 } else { 1460 char *tmp; 1461 1462 hi = strtoport(p, uflag); 1463 if (asprintf(&tmp, "%d", hi) != -1) 1464 portlist[0] = tmp; 1465 else 1466 err(1, NULL); 1467 } 1468 } 1469 1470 /* 1471 * udptest() 1472 * Do a few writes to see if the UDP port is there. 1473 * Fails once PF state table is full. 1474 */ 1475 int 1476 udptest(int s) 1477 { 1478 int i, ret; 1479 1480 for (i = 0; i <= 3; i++) { 1481 if (write(s, "X", 1) == 1) 1482 ret = 1; 1483 else 1484 ret = -1; 1485 } 1486 return (ret); 1487 } 1488 1489 void 1490 set_common_sockopts(int s, int af) 1491 { 1492 int x = 1; 1493 1494 if (Sflag) { 1495 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1496 &x, sizeof(x)) == -1) 1497 err(1, NULL); 1498 } 1499 if (Dflag) { 1500 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1501 &x, sizeof(x)) == -1) 1502 err(1, NULL); 1503 } 1504 if (Tflag != -1) { 1505 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1506 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1507 err(1, "set IP ToS"); 1508 1509 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1510 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1511 err(1, "set IPv6 traffic class"); 1512 } 1513 if (Iflag) { 1514 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1515 &Iflag, sizeof(Iflag)) == -1) 1516 err(1, "set TCP receive buffer size"); 1517 } 1518 if (Oflag) { 1519 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1520 &Oflag, sizeof(Oflag)) == -1) 1521 err(1, "set TCP send buffer size"); 1522 } 1523 1524 if (ttl != -1) { 1525 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1526 IP_TTL, &ttl, sizeof(ttl))) 1527 err(1, "set IP TTL"); 1528 1529 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1530 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1531 err(1, "set IPv6 unicast hops"); 1532 } 1533 1534 if (minttl != -1) { 1535 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1536 IP_MINTTL, &minttl, sizeof(minttl))) 1537 err(1, "set IP min TTL"); 1538 #ifdef IPV6_MINHOPCOUNT 1539 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1540 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1541 err(1, "set IPv6 min hop count"); 1542 #endif 1543 } 1544 } 1545 1546 int 1547 map_tos(char *s, int *val) 1548 { 1549 /* DiffServ Codepoints and other TOS mappings */ 1550 const struct toskeywords { 1551 const char *keyword; 1552 int val; 1553 } *t, toskeywords[] = { 1554 { "af11", IPTOS_DSCP_AF11 }, 1555 { "af12", IPTOS_DSCP_AF12 }, 1556 { "af13", IPTOS_DSCP_AF13 }, 1557 { "af21", IPTOS_DSCP_AF21 }, 1558 { "af22", IPTOS_DSCP_AF22 }, 1559 { "af23", IPTOS_DSCP_AF23 }, 1560 { "af31", IPTOS_DSCP_AF31 }, 1561 { "af32", IPTOS_DSCP_AF32 }, 1562 { "af33", IPTOS_DSCP_AF33 }, 1563 { "af41", IPTOS_DSCP_AF41 }, 1564 { "af42", IPTOS_DSCP_AF42 }, 1565 { "af43", IPTOS_DSCP_AF43 }, 1566 { "critical", IPTOS_PREC_CRITIC_ECP }, 1567 { "cs0", IPTOS_DSCP_CS0 }, 1568 { "cs1", IPTOS_DSCP_CS1 }, 1569 { "cs2", IPTOS_DSCP_CS2 }, 1570 { "cs3", IPTOS_DSCP_CS3 }, 1571 { "cs4", IPTOS_DSCP_CS4 }, 1572 { "cs5", IPTOS_DSCP_CS5 }, 1573 { "cs6", IPTOS_DSCP_CS6 }, 1574 { "cs7", IPTOS_DSCP_CS7 }, 1575 { "ef", IPTOS_DSCP_EF }, 1576 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1577 { "lowdelay", IPTOS_LOWDELAY }, 1578 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1579 { "reliability", IPTOS_RELIABILITY }, 1580 { "throughput", IPTOS_THROUGHPUT }, 1581 { NULL, -1 }, 1582 }; 1583 1584 for (t = toskeywords; t->keyword != NULL; t++) { 1585 if (strcmp(s, t->keyword) == 0) { 1586 *val = t->val; 1587 return (1); 1588 } 1589 } 1590 1591 return (0); 1592 } 1593 1594 #ifdef CRYPTO 1595 int 1596 map_tls(char *s, int *val) 1597 { 1598 const struct tlskeywords { 1599 const char *keyword; 1600 int val; 1601 } *t, tlskeywords[] = { 1602 { "tlsall", TLS_ALL }, 1603 { "noverify", TLS_NOVERIFY }, 1604 { "noname", TLS_NONAME }, 1605 { "clientcert", TLS_CCERT}, 1606 { "muststaple", TLS_MUSTSTAPLE}, 1607 { NULL, -1 }, 1608 }; 1609 1610 for (t = tlskeywords; t->keyword != NULL; t++) { 1611 if (strcmp(s, t->keyword) == 0) { 1612 *val |= t->val; 1613 return (1); 1614 } 1615 } 1616 return (0); 1617 } 1618 1619 void 1620 report_tls(struct tls * tls_ctx, char * host, char *tlsexpectname) 1621 { 1622 time_t t; 1623 const char *ocsp_url; 1624 1625 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1626 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1627 fprintf(stderr, "Peer name: %s\n", 1628 tlsexpectname ? tlsexpectname : host); 1629 if (tls_peer_cert_subject(tls_ctx)) 1630 fprintf(stderr, "Subject: %s\n", 1631 tls_peer_cert_subject(tls_ctx)); 1632 if (tls_peer_cert_issuer(tls_ctx)) 1633 fprintf(stderr, "Issuer: %s\n", 1634 tls_peer_cert_issuer(tls_ctx)); 1635 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1636 fprintf(stderr, "Valid From: %s", ctime(&t)); 1637 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1638 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1639 if (tls_peer_cert_hash(tls_ctx)) 1640 fprintf(stderr, "Cert Hash: %s\n", 1641 tls_peer_cert_hash(tls_ctx)); 1642 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1643 if (ocsp_url != NULL) 1644 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1645 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1646 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1647 fprintf(stderr, "OCSP Stapling: %s\n", 1648 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1649 tls_peer_ocsp_result(tls_ctx)); 1650 fprintf(stderr, 1651 " response_status=%d cert_status=%d crl_reason=%d\n", 1652 tls_peer_ocsp_response_status(tls_ctx), 1653 tls_peer_ocsp_cert_status(tls_ctx), 1654 tls_peer_ocsp_crl_reason(tls_ctx)); 1655 t = tls_peer_ocsp_this_update(tls_ctx); 1656 fprintf(stderr, " this update: %s", 1657 t != -1 ? ctime(&t) : "\n"); 1658 t = tls_peer_ocsp_next_update(tls_ctx); 1659 fprintf(stderr, " next update: %s", 1660 t != -1 ? ctime(&t) : "\n"); 1661 t = tls_peer_ocsp_revocation_time(tls_ctx); 1662 fprintf(stderr, " revocation: %s", 1663 t != -1 ? ctime(&t) : "\n"); 1664 break; 1665 case -1: 1666 break; 1667 default: 1668 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1669 tls_peer_ocsp_response_status(tls_ctx), 1670 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1671 tls_peer_ocsp_result(tls_ctx)); 1672 break; 1673 1674 } 1675 } 1676 #endif 1677 1678 void 1679 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1680 { 1681 char remote_host[NI_MAXHOST]; 1682 char remote_port[NI_MAXSERV]; 1683 int herr; 1684 int flags = NI_NUMERICSERV; 1685 1686 if (path != NULL) { 1687 fprintf(stderr, "Connection on %s received!\n", path); 1688 return; 1689 } 1690 1691 if (nflag) 1692 flags |= NI_NUMERICHOST; 1693 1694 if ((herr = getnameinfo(sa, salen, 1695 remote_host, sizeof(remote_host), 1696 remote_port, sizeof(remote_port), 1697 flags)) != 0) { 1698 if (herr == EAI_SYSTEM) 1699 err(1, "getnameinfo"); 1700 else 1701 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1702 } 1703 1704 fprintf(stderr, 1705 "Connection from %s %s " 1706 "received!\n", remote_host, remote_port); 1707 } 1708 1709 void 1710 help(void) 1711 { 1712 usage(0); 1713 fprintf(stderr, "\tCommand Summary:\n" 1714 1715 "\t-4 Use IPv4\n" 1716 "\t-6 Use IPv6\n" 1717 #ifdef CRYPTO 1718 "\t-C certfile Public key file\n" 1719 "\t-c Use TLS\n" 1720 #endif 1721 "\t-D Enable the debug socket option\n" 1722 "\t-d Detach from stdin\n" 1723 #ifdef CRYPTO 1724 "\t-e name\t Required name in peer certificate\n" 1725 #endif 1726 "\t-F Pass socket fd\n" 1727 #ifdef CRYPTO 1728 "\t-H hash\t Hash string of peer certificate\n" 1729 #endif 1730 "\t-h This help text\n" 1731 "\t-I length TCP receive buffer length\n" 1732 "\t-i interval Delay interval for lines sent, ports scanned\n" 1733 #ifdef CRYPTO 1734 "\t-K keyfile Private key file\n" 1735 #endif 1736 "\t-k Keep inbound sockets open for multiple connects\n" 1737 "\t-l Listen mode, for inbound connects\n" 1738 "\t-M ttl Outgoing TTL / Hop Limit\n" 1739 "\t-m minttl Minimum incoming TTL / Hop Limit\n" 1740 "\t-N Shutdown the network socket after EOF on stdin\n" 1741 "\t-n Suppress name/port resolutions\n" 1742 "\t-O length TCP send buffer length\n" 1743 #ifdef CRYPTO 1744 "\t-o staplefile Staple file\n" 1745 #endif 1746 "\t-P proxyuser\tUsername for proxy authentication\n" 1747 "\t-p port\t Specify local port for remote connects\n" 1748 #ifdef CRYPTO 1749 "\t-R CAfile CA bundle\n" 1750 #endif 1751 "\t-r Randomize remote ports\n" 1752 "\t-S Enable the TCP MD5 signature option\n" 1753 "\t-s source Local source address\n" 1754 #ifdef CRYPTO 1755 "\t-T keyword TOS value or TLS options\n" 1756 #endif 1757 "\t-t Answer TELNET negotiation\n" 1758 "\t-U Use UNIX domain socket\n" 1759 "\t-u UDP mode\n" 1760 #ifdef __OpenBSD__ 1761 "\t-V rtable Specify alternate routing table\n" 1762 #endif 1763 "\t-v Verbose\n" 1764 "\t-w timeout Timeout for connects and final net reads\n" 1765 "\t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n" 1766 "\t-x addr[:port]\tSpecify proxy address and port\n" 1767 "\t-z Zero-I/O mode [used for scanning]\n" 1768 "Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1769 exit(1); 1770 } 1771 1772 void 1773 usage(int ret) 1774 { 1775 fprintf(stderr, 1776 "Usage: %s [-46%sDdFhklNnrStUuvz] [-e name] [-I length]\n" 1777 #ifdef CRYPTO 1778 "\t [-C certfile] [-H hash] [-K keyfile] [-R CAfile] " 1779 "[-T keyword] [-o staplefile]\n" 1780 #endif 1781 "\t [-i interval] [-M ttl] [-m minttl] [-O length]\n" 1782 "\t [-P proxy_username] [-p source_port]\n" 1783 "\t [-s source] " 1784 #ifdef __OpenBSD__ 1785 "[-V rtable] " 1786 #endif 1787 "[-w timeout] [-X proxy_protocol]\n" 1788 "\t [-x proxy_address[:port]] [destination] [port]\n", 1789 getprogname(), 1790 #ifdef CRYPTO 1791 "c" 1792 #else 1793 "" 1794 #endif 1795 ); 1796 if (ret) 1797 exit(1); 1798 } 1799
Indexes created Sun Sep 21 19:09:51 GMT 2025