1 /* $OpenBSD: netcat.c,v 1.219 2022/06/08 20:07:31 tb Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org> 4 * Copyright (c) 2015 Bob Beck. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * Re-written nc(1) for OpenBSD. Original implementation by 32 * *Hobbit* <hobbit@avian.org>. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 40 #include <netinet/in.h> 41 #include <netinet/tcp.h> 42 #include <netinet/ip.h> 43 #include <arpa/telnet.h> 44 45 #include <ctype.h> 46 #include <err.h> 47 #include <errno.h> 48 #include <limits.h> 49 #include <netdb.h> 50 #include <poll.h> 51 #include <signal.h> 52 #include <stdarg.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <time.h> 57 #include <tls.h> 58 #include <unistd.h> 59 60 #include "atomicio.h" 61 62 #if !defined(OpenBSD) 63 #define pledge(request, paths) 0 64 #define unveil(path, permissions) 0 65 #endif 66 67 #define PORT_MAX 65535 68 #define UNIX_DG_TMP_SOCKET_SIZE 19 69 70 #define POLL_STDIN 0 71 #define POLL_NETOUT 1 72 #define POLL_NETIN 2 73 #define POLL_STDOUT 3 74 #define BUFSIZE 16384 75 76 #define TLS_NOVERIFY (1 << 1) 77 #define TLS_NONAME (1 << 2) 78 #define TLS_CCERT (1 << 3) 79 #define TLS_MUSTSTAPLE (1 << 4) 80 81 /* Command Line Options */ 82 int dflag; /* detached, no stdin */ 83 int Fflag; /* fdpass sock to stdout */ 84 unsigned int iflag; /* Interval Flag */ 85 int kflag; /* More than one connect */ 86 int lflag; /* Bind to local port */ 87 int Nflag; /* shutdown() network socket */ 88 int nflag; /* Don't do name look up */ 89 char *Pflag; /* Proxy username */ 90 char *pflag; /* Localport flag */ 91 int rflag; /* Random ports flag */ 92 char *sflag; /* Source Address */ 93 int tflag; /* Telnet Emulation */ 94 int uflag; /* UDP - Default to TCP */ 95 int vflag; /* Verbosity */ 96 int xflag; /* Socks proxy */ 97 int zflag; /* Port Scan Flag */ 98 int Dflag; /* sodebug */ 99 int Iflag; /* TCP receive buffer size */ 100 int Oflag; /* TCP send buffer size */ 101 #ifdef TCP_MD5SIG 102 int Sflag; /* TCP MD5 signature option */ 103 #endif 104 int Tflag = -1; /* IP Type of Service */ 105 #ifdef SO_RTABLE 106 int rtableid = -1; 107 #endif 108 109 int usetls; /* use TLS */ 110 const char *Cflag; /* Public cert file */ 111 const char *Kflag; /* Private key file */ 112 const char *oflag; /* OCSP stapling file */ 113 const char *Rflag; /* Root CA file */ 114 int tls_cachanged; /* Using non-default CA file */ 115 int TLSopt; /* TLS options */ 116 char *tls_expectname; /* required name in peer cert */ 117 char *tls_expecthash; /* required hash of peer cert */ 118 char *tls_ciphers; /* TLS ciphers */ 119 char *tls_protocols; /* TLS protocols */ 120 FILE *Zflag; /* file to save peer cert */ 121 122 int recvcount, recvlimit; 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 int strtoport(char *portstr, int udp); 132 void build_ports(char *); 133 void help(void) __attribute__((noreturn)); 134 int local_listen(const char *, const char *, struct addrinfo); 135 void readwrite(int, struct tls *); 136 void fdpass(int nfd) __attribute__((noreturn)); 137 int remote_connect(const char *, const char *, struct addrinfo, char *); 138 int timeout_tls(int, struct tls *, int (*)(struct tls *)); 139 int timeout_connect(int, const struct sockaddr *, socklen_t); 140 int socks_connect(const char *, const char *, struct addrinfo, 141 const char *, const char *, struct addrinfo, int, const char *); 142 int udptest(int); 143 int unix_bind(char *, int); 144 int unix_connect(char *); 145 int unix_listen(char *); 146 void set_common_sockopts(int, int); 147 int process_tos_opt(char *, int *); 148 int process_tls_opt(char *, int *); 149 void save_peer_cert(struct tls *_tls_ctx, FILE *_fp); 150 void report_sock(const char *, const struct sockaddr *, socklen_t, char *); 151 void report_tls(struct tls *tls_ctx, char * host); 152 void usage(int); 153 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 154 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 155 void tls_setup_client(struct tls *, int, char *); 156 struct tls *tls_setup_server(struct tls *, int, char *); 157 158 int 159 main(int argc, char *argv[]) 160 { 161 int ch, s = -1, ret, socksv; 162 char *host, *uport; 163 char ipaddr[NI_MAXHOST]; 164 struct addrinfo hints; 165 struct servent *sv; 166 socklen_t len; 167 struct sockaddr_storage cliaddr; 168 char *proxy = NULL, *proxyport = NULL; 169 const char *errstr; 170 struct addrinfo proxyhints; 171 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 172 struct tls_config *tls_cfg = NULL; 173 struct tls *tls_ctx = NULL; 174 uint32_t protocols; 175 176 ret = 1; 177 socksv = 5; 178 host = NULL; 179 uport = NULL; 180 sv = NULL; 181 Rflag = tls_default_ca_cert_file(); 182 183 signal(SIGPIPE, SIG_IGN); 184 185 while ((ch = getopt(argc, argv, 186 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z")) 187 != -1) { 188 switch (ch) { 189 case '4': 190 family = AF_INET; 191 break; 192 case '6': 193 family = AF_INET6; 194 break; 195 case 'U': 196 family = AF_UNIX; 197 break; 198 case 'X': 199 if (strcasecmp(optarg, "connect") == 0) 200 socksv = -1; /* HTTP proxy CONNECT */ 201 else if (strcmp(optarg, "4") == 0) 202 socksv = 4; /* SOCKS v.4 */ 203 else if (strcmp(optarg, "5") == 0) 204 socksv = 5; /* SOCKS v.5 */ 205 else 206 errx(1, "unsupported proxy protocol"); 207 break; 208 case 'C': 209 Cflag = optarg; 210 break; 211 case 'c': 212 usetls = 1; 213 break; 214 case 'd': 215 dflag = 1; 216 break; 217 case 'e': 218 tls_expectname = optarg; 219 break; 220 case 'F': 221 Fflag = 1; 222 break; 223 case 'H': 224 tls_expecthash = optarg; 225 break; 226 case 'h': 227 help(); 228 break; 229 case 'i': 230 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 231 if (errstr) 232 errx(1, "interval %s: %s", errstr, optarg); 233 break; 234 case 'K': 235 Kflag = optarg; 236 break; 237 case 'k': 238 kflag = 1; 239 break; 240 case 'l': 241 lflag = 1; 242 break; 243 case 'M': 244 ttl = strtonum(optarg, 0, 255, &errstr); 245 if (errstr) 246 errx(1, "ttl is %s", errstr); 247 break; 248 case 'm': 249 minttl = strtonum(optarg, 0, 255, &errstr); 250 if (errstr) 251 errx(1, "minttl is %s", errstr); 252 break; 253 case 'N': 254 Nflag = 1; 255 break; 256 case 'n': 257 nflag = 1; 258 break; 259 case 'P': 260 Pflag = optarg; 261 break; 262 case 'p': 263 pflag = optarg; 264 break; 265 case 'R': 266 tls_cachanged = 1; 267 Rflag = optarg; 268 break; 269 case 'r': 270 rflag = 1; 271 break; 272 case 's': 273 sflag = optarg; 274 break; 275 case 't': 276 tflag = 1; 277 break; 278 case 'u': 279 uflag = 1; 280 break; 281 #ifdef SO_RTABLE 282 case 'V': 283 rtableid = (int)strtonum(optarg, 0, 284 RT_TABLEID_MAX, &errstr); 285 if (errstr) 286 errx(1, "rtable %s: %s", errstr, optarg); 287 break; 288 #endif 289 case 'v': 290 vflag = 1; 291 break; 292 case 'W': 293 recvlimit = strtonum(optarg, 1, INT_MAX, &errstr); 294 if (errstr) 295 errx(1, "receive limit %s: %s", errstr, optarg); 296 break; 297 case 'w': 298 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 299 if (errstr) 300 errx(1, "timeout %s: %s", errstr, optarg); 301 timeout *= 1000; 302 break; 303 case 'x': 304 xflag = 1; 305 if ((proxy = strdup(optarg)) == NULL) 306 err(1, NULL); 307 break; 308 case 'Z': 309 if (strcmp(optarg, "-") == 0) 310 Zflag = stderr; 311 else if ((Zflag = fopen(optarg, "w")) == NULL) 312 err(1, "can't open %s", optarg); 313 break; 314 case 'z': 315 zflag = 1; 316 break; 317 case 'D': 318 Dflag = 1; 319 break; 320 case 'I': 321 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 322 if (errstr != NULL) 323 errx(1, "TCP receive window %s: %s", 324 errstr, optarg); 325 break; 326 case 'O': 327 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 328 if (errstr != NULL) 329 errx(1, "TCP send window %s: %s", 330 errstr, optarg); 331 break; 332 case 'o': 333 oflag = optarg; 334 break; 335 #ifdef TCP_MD5SIG 336 case 'S': 337 Sflag = 1; 338 break; 339 #endif 340 case 'T': 341 errstr = NULL; 342 errno = 0; 343 if (process_tls_opt(optarg, &TLSopt)) 344 break; 345 if (process_tos_opt(optarg, &Tflag)) 346 break; 347 if (strlen(optarg) > 1 && optarg[0] == '0' && 348 optarg[1] == 'x') 349 Tflag = (int)strtol(optarg, NULL, 16); 350 else 351 Tflag = (int)strtonum(optarg, 0, 255, 352 &errstr); 353 if (Tflag < 0 || Tflag > 255 || errstr || errno) 354 errx(1, "illegal tos/tls value %s", optarg); 355 break; 356 default: 357 usage(1); 358 } 359 } 360 argc -= optind; 361 argv += optind; 362 363 #ifdef SO_RTABLE 364 if (rtableid >= 0) 365 if (setrtable(rtableid) == -1) 366 err(1, "setrtable"); 367 #endif 368 369 /* Cruft to make sure options are clean, and used properly. */ 370 if (argc == 1 && family == AF_UNIX) { 371 host = argv[0]; 372 } else if (argc == 1 && lflag) { 373 uport = argv[0]; 374 } else if (argc == 2) { 375 host = argv[0]; 376 uport = argv[1]; 377 } else 378 usage(1); 379 380 if (usetls) { 381 if (Cflag && unveil(Cflag, "r") == -1) 382 err(1, "unveil %s", Cflag); 383 if (unveil(Rflag, "r") == -1) 384 err(1, "unveil %s", Rflag); 385 if (Kflag && unveil(Kflag, "r") == -1) 386 err(1, "unveil %s", Kflag); 387 if (oflag && unveil(oflag, "r") == -1) 388 err(1, "unveil %s", oflag); 389 } else if (family == AF_UNIX && uflag && lflag && !kflag) { 390 /* 391 * After recvfrom(2) from client, the server connects 392 * to the client socket. As the client path is determined 393 * during runtime, we cannot unveil(2). 394 */ 395 } else { 396 if (family == AF_UNIX) { 397 if (unveil(host, "rwc") == -1) 398 err(1, "unveil %s", host); 399 if (uflag && !kflag) { 400 if (sflag) { 401 if (unveil(sflag, "rwc") == -1) 402 err(1, "unveil %s", sflag); 403 } else { 404 if (unveil("/tmp", "rwc") == -1) 405 err(1, "unveil /tmp"); 406 } 407 } 408 } else { 409 /* no filesystem visibility */ 410 if (unveil("/", "") == -1) 411 err(1, "unveil /"); 412 } 413 } 414 415 if (family == AF_UNIX) { 416 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 417 err(1, "pledge"); 418 } else if (Fflag && Pflag) { 419 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 420 err(1, "pledge"); 421 } else if (Fflag) { 422 if (pledge("stdio inet dns sendfd", NULL) == -1) 423 err(1, "pledge"); 424 } else if (Pflag && usetls) { 425 if (pledge("stdio rpath inet dns tty", NULL) == -1) 426 err(1, "pledge"); 427 } else if (Pflag) { 428 if (pledge("stdio inet dns tty", NULL) == -1) 429 err(1, "pledge"); 430 } else if (usetls) { 431 if (pledge("stdio rpath inet dns", NULL) == -1) 432 err(1, "pledge"); 433 } else if (pledge("stdio inet dns", NULL) == -1) 434 err(1, "pledge"); 435 436 if (lflag && sflag) 437 errx(1, "cannot use -s and -l"); 438 if (lflag && pflag) 439 errx(1, "cannot use -p and -l"); 440 if (lflag && zflag) 441 errx(1, "cannot use -z and -l"); 442 if (!lflag && kflag) 443 errx(1, "must use -l with -k"); 444 if (uflag && usetls) 445 errx(1, "cannot use -c and -u"); 446 if ((family == AF_UNIX) && usetls) 447 errx(1, "cannot use -c and -U"); 448 if ((family == AF_UNIX) && Fflag) 449 errx(1, "cannot use -F and -U"); 450 if (Fflag && usetls) 451 errx(1, "cannot use -c and -F"); 452 if (TLSopt && !usetls) 453 errx(1, "you must specify -c to use TLS options"); 454 if (Cflag && !usetls) 455 errx(1, "you must specify -c to use -C"); 456 if (Kflag && !usetls) 457 errx(1, "you must specify -c to use -K"); 458 if (Zflag && !usetls) 459 errx(1, "you must specify -c to use -Z"); 460 if (oflag && !Cflag) 461 errx(1, "you must specify -C to use -o"); 462 if (tls_cachanged && !usetls) 463 errx(1, "you must specify -c to use -R"); 464 if (tls_expecthash && !usetls) 465 errx(1, "you must specify -c to use -H"); 466 if (tls_expectname && !usetls) 467 errx(1, "you must specify -c to use -e"); 468 469 /* Get name of temporary socket for unix datagram client */ 470 if ((family == AF_UNIX) && uflag && !lflag) { 471 if (sflag) { 472 unix_dg_tmp_socket = sflag; 473 } else { 474 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 475 UNIX_DG_TMP_SOCKET_SIZE); 476 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 477 err(1, "mktemp"); 478 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 479 } 480 } 481 482 /* Initialize addrinfo structure. */ 483 if (family != AF_UNIX) { 484 memset(&hints, 0, sizeof(struct addrinfo)); 485 hints.ai_family = family; 486 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 487 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 488 if (nflag) 489 hints.ai_flags |= AI_NUMERICHOST; 490 } 491 492 if (xflag) { 493 if (uflag) 494 errx(1, "no proxy support for UDP mode"); 495 496 if (lflag) 497 errx(1, "no proxy support for listen"); 498 499 if (family == AF_UNIX) 500 errx(1, "no proxy support for unix sockets"); 501 502 if (sflag) 503 errx(1, "no proxy support for local source address"); 504 505 if (*proxy == '[') { 506 ++proxy; 507 proxyport = strchr(proxy, ']'); 508 if (proxyport == NULL) 509 errx(1, "missing closing bracket in proxy"); 510 *proxyport++ = '\0'; 511 if (*proxyport == '\0') 512 /* Use default proxy port. */ 513 proxyport = NULL; 514 else { 515 if (*proxyport == ':') 516 ++proxyport; 517 else 518 errx(1, "garbage proxy port delimiter"); 519 } 520 } else { 521 proxyport = strrchr(proxy, ':'); 522 if (proxyport != NULL) 523 *proxyport++ = '\0'; 524 } 525 526 memset(&proxyhints, 0, sizeof(struct addrinfo)); 527 proxyhints.ai_family = family; 528 proxyhints.ai_socktype = SOCK_STREAM; 529 proxyhints.ai_protocol = IPPROTO_TCP; 530 if (nflag) 531 proxyhints.ai_flags |= AI_NUMERICHOST; 532 } 533 534 if (usetls) { 535 if ((tls_cfg = tls_config_new()) == NULL) 536 errx(1, "unable to allocate TLS config"); 537 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 538 errx(1, "%s", tls_config_error(tls_cfg)); 539 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 540 errx(1, "%s", tls_config_error(tls_cfg)); 541 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 542 errx(1, "%s", tls_config_error(tls_cfg)); 543 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 544 errx(1, "%s", tls_config_error(tls_cfg)); 545 if (tls_config_parse_protocols(&protocols, tls_protocols) == -1) 546 errx(1, "invalid TLS protocols `%s'", tls_protocols); 547 if (tls_config_set_protocols(tls_cfg, protocols) == -1) 548 errx(1, "%s", tls_config_error(tls_cfg)); 549 if (tls_config_set_ciphers(tls_cfg, tls_ciphers) == -1) 550 errx(1, "%s", tls_config_error(tls_cfg)); 551 if (!lflag && (TLSopt & TLS_CCERT)) 552 errx(1, "clientcert is only valid with -l"); 553 if (TLSopt & TLS_NONAME) 554 tls_config_insecure_noverifyname(tls_cfg); 555 if (TLSopt & TLS_NOVERIFY) { 556 if (tls_expecthash != NULL) 557 errx(1, "-H and -T noverify may not be used " 558 "together"); 559 tls_config_insecure_noverifycert(tls_cfg); 560 } 561 if (TLSopt & TLS_MUSTSTAPLE) 562 tls_config_ocsp_require_stapling(tls_cfg); 563 564 if (Pflag) { 565 if (pledge("stdio inet dns tty", NULL) == -1) 566 err(1, "pledge"); 567 } else if (pledge("stdio inet dns", NULL) == -1) 568 err(1, "pledge"); 569 } 570 if (lflag) { 571 ret = 0; 572 573 if (family == AF_UNIX) { 574 if (uflag) 575 s = unix_bind(host, 0); 576 else 577 s = unix_listen(host); 578 } 579 580 if (usetls) { 581 tls_config_verify_client_optional(tls_cfg); 582 if ((tls_ctx = tls_server()) == NULL) 583 errx(1, "tls server creation failed"); 584 if (tls_configure(tls_ctx, tls_cfg) == -1) 585 errx(1, "tls configuration failed (%s)", 586 tls_error(tls_ctx)); 587 } 588 /* Allow only one connection at a time, but stay alive. */ 589 for (;;) { 590 if (family != AF_UNIX) { 591 if (s != -1) 592 close(s); 593 s = local_listen(host, uport, hints); 594 } 595 if (s == -1) 596 err(1, NULL); 597 if (uflag && kflag) { 598 if (family == AF_UNIX) { 599 if (pledge("stdio unix", NULL) == -1) 600 err(1, "pledge"); 601 } 602 /* 603 * For UDP and -k, don't connect the socket, 604 * let it receive datagrams from multiple 605 * socket pairs. 606 */ 607 readwrite(s, NULL); 608 } else if (uflag && !kflag) { 609 /* 610 * For UDP and not -k, we will use recvfrom() 611 * initially to wait for a caller, then use 612 * the regular functions to talk to the caller. 613 */ 614 int rv; 615 char buf[2048]; 616 struct sockaddr_storage z; 617 618 len = sizeof(z); 619 rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK, 620 (struct sockaddr *)&z, &len); 621 if (rv == -1) 622 err(1, "recvfrom"); 623 624 rv = connect(s, (struct sockaddr *)&z, len); 625 if (rv == -1) 626 err(1, "connect"); 627 628 if (family == AF_UNIX) { 629 if (pledge("stdio unix", NULL) == -1) 630 err(1, "pledge"); 631 } 632 if (vflag) 633 report_sock("Connection received", 634 (struct sockaddr *)&z, len, 635 family == AF_UNIX ? host : NULL); 636 637 readwrite(s, NULL); 638 } else { 639 struct tls *tls_cctx = NULL; 640 int connfd; 641 642 len = sizeof(cliaddr); 643 connfd = accept4(s, (struct sockaddr *)&cliaddr, 644 &len, SOCK_NONBLOCK); 645 if (connfd == -1) { 646 /* For now, all errnos are fatal */ 647 err(1, "accept"); 648 } 649 if (vflag) 650 report_sock("Connection received", 651 (struct sockaddr *)&cliaddr, len, 652 family == AF_UNIX ? host : NULL); 653 if ((usetls) && 654 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 655 readwrite(connfd, tls_cctx); 656 if (!usetls) 657 readwrite(connfd, NULL); 658 if (tls_cctx) 659 timeout_tls(s, tls_cctx, tls_close); 660 close(connfd); 661 tls_free(tls_cctx); 662 } 663 if (family == AF_UNIX && uflag) { 664 if (connect(s, NULL, 0) == -1) 665 err(1, "connect"); 666 } 667 668 if (!kflag) 669 break; 670 } 671 } else if (family == AF_UNIX) { 672 ret = 0; 673 674 if ((s = unix_connect(host)) > 0) { 675 if (!zflag) 676 readwrite(s, NULL); 677 close(s); 678 } else { 679 warn("%s", host); 680 ret = 1; 681 } 682 683 if (uflag) 684 unlink(unix_dg_tmp_socket); 685 return ret; 686 } else { 687 int i = 0; 688 689 /* Construct the portlist[] array. */ 690 build_ports(uport); 691 692 /* Cycle through portlist, connecting to each port. */ 693 for (s = -1, i = 0; portlist[i] != NULL; i++) { 694 if (s != -1) 695 close(s); 696 tls_free(tls_ctx); 697 tls_ctx = NULL; 698 699 if (usetls) { 700 if ((tls_ctx = tls_client()) == NULL) 701 errx(1, "tls client creation failed"); 702 if (tls_configure(tls_ctx, tls_cfg) == -1) 703 errx(1, "tls configuration failed (%s)", 704 tls_error(tls_ctx)); 705 } 706 if (xflag) 707 s = socks_connect(host, portlist[i], hints, 708 proxy, proxyport, proxyhints, socksv, 709 Pflag); 710 else 711 s = remote_connect(host, portlist[i], hints, 712 ipaddr); 713 714 if (s == -1) 715 continue; 716 717 ret = 0; 718 if (vflag || zflag) { 719 /* For UDP, make sure we are connected. */ 720 if (uflag) { 721 if (udptest(s) == -1) { 722 ret = 1; 723 continue; 724 } 725 } 726 727 /* Don't look up port if -n. */ 728 if (nflag) 729 sv = NULL; 730 else { 731 sv = getservbyport( 732 ntohs(atoi(portlist[i])), 733 uflag ? "udp" : "tcp"); 734 } 735 736 fprintf(stderr, "Connection to %s", host); 737 738 /* 739 * if we aren't connecting thru a proxy and 740 * there is something to report, print IP 741 */ 742 if (!nflag && !xflag && 743 strcmp(host, ipaddr) != 0) 744 fprintf(stderr, " (%s)", ipaddr); 745 746 fprintf(stderr, " %s port [%s/%s] succeeded!\n", 747 portlist[i], uflag ? "udp" : "tcp", 748 sv ? sv->s_name : "*"); 749 } 750 if (Fflag) 751 fdpass(s); 752 else { 753 if (usetls) 754 tls_setup_client(tls_ctx, s, host); 755 if (!zflag) 756 readwrite(s, tls_ctx); 757 if (tls_ctx) 758 timeout_tls(s, tls_ctx, tls_close); 759 } 760 } 761 } 762 763 if (s != -1) 764 close(s); 765 tls_free(tls_ctx); 766 tls_config_free(tls_cfg); 767 768 return ret; 769 } 770 771 /* 772 * unix_bind() 773 * Returns a unix socket bound to the given path 774 */ 775 int 776 unix_bind(char *path, int flags) 777 { 778 struct sockaddr_un s_un; 779 int s, save_errno; 780 781 /* Create unix domain socket. */ 782 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 783 0)) == -1) 784 return -1; 785 786 memset(&s_un, 0, sizeof(struct sockaddr_un)); 787 s_un.sun_family = AF_UNIX; 788 789 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 790 sizeof(s_un.sun_path)) { 791 close(s); 792 errno = ENAMETOOLONG; 793 return -1; 794 } 795 796 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { 797 save_errno = errno; 798 close(s); 799 errno = save_errno; 800 return -1; 801 } 802 if (vflag) 803 report_sock("Bound", NULL, 0, path); 804 805 return s; 806 } 807 808 int 809 timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) 810 { 811 struct pollfd pfd; 812 int ret; 813 814 while ((ret = (*func)(tls_ctx)) != 0) { 815 if (ret == TLS_WANT_POLLIN) 816 pfd.events = POLLIN; 817 else if (ret == TLS_WANT_POLLOUT) 818 pfd.events = POLLOUT; 819 else 820 break; 821 pfd.fd = s; 822 if ((ret = poll(&pfd, 1, timeout)) == 1) 823 continue; 824 else if (ret == 0) { 825 errno = ETIMEDOUT; 826 ret = -1; 827 break; 828 } else 829 err(1, "poll failed"); 830 } 831 832 return ret; 833 } 834 835 void 836 tls_setup_client(struct tls *tls_ctx, int s, char *host) 837 { 838 const char *errstr; 839 840 if (tls_connect_socket(tls_ctx, s, 841 tls_expectname ? tls_expectname : host) == -1) { 842 errx(1, "tls connection failed (%s)", 843 tls_error(tls_ctx)); 844 } 845 if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { 846 if ((errstr = tls_error(tls_ctx)) == NULL) 847 errstr = strerror(errno); 848 errx(1, "tls handshake failed (%s)", errstr); 849 } 850 if (vflag) 851 report_tls(tls_ctx, host); 852 if (tls_expecthash && (tls_peer_cert_hash(tls_ctx) == NULL || 853 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0)) 854 errx(1, "peer certificate is not %s", tls_expecthash); 855 if (Zflag) { 856 save_peer_cert(tls_ctx, Zflag); 857 if (Zflag != stderr && (fclose(Zflag) != 0)) 858 err(1, "fclose failed saving peer cert"); 859 } 860 } 861 862 struct tls * 863 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 864 { 865 struct tls *tls_cctx; 866 const char *errstr; 867 868 if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { 869 warnx("tls accept failed (%s)", tls_error(tls_ctx)); 870 } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { 871 if ((errstr = tls_error(tls_cctx)) == NULL) 872 errstr = strerror(errno); 873 warnx("tls handshake failed (%s)", errstr); 874 } else { 875 int gotcert = tls_peer_cert_provided(tls_cctx); 876 877 if (vflag && gotcert) 878 report_tls(tls_cctx, host); 879 if ((TLSopt & TLS_CCERT) && !gotcert) 880 warnx("No client certificate provided"); 881 else if (gotcert && tls_expecthash && 882 (tls_peer_cert_hash(tls_cctx) == NULL || 883 strcmp(tls_expecthash, tls_peer_cert_hash(tls_cctx)) != 0)) 884 warnx("peer certificate is not %s", tls_expecthash); 885 else if (gotcert && tls_expectname && 886 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 887 warnx("name (%s) not found in client cert", 888 tls_expectname); 889 else { 890 return tls_cctx; 891 } 892 } 893 return NULL; 894 } 895 896 /* 897 * unix_connect() 898 * Returns a socket connected to a local unix socket. Returns -1 on failure. 899 */ 900 int 901 unix_connect(char *path) 902 { 903 struct sockaddr_un s_un; 904 int s, save_errno; 905 906 if (uflag) { 907 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) == -1) 908 return -1; 909 } else { 910 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) == -1) 911 return -1; 912 } 913 914 memset(&s_un, 0, sizeof(struct sockaddr_un)); 915 s_un.sun_family = AF_UNIX; 916 917 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 918 sizeof(s_un.sun_path)) { 919 close(s); 920 errno = ENAMETOOLONG; 921 return -1; 922 } 923 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { 924 save_errno = errno; 925 close(s); 926 errno = save_errno; 927 return -1; 928 } 929 return s; 930 } 931 932 /* 933 * unix_listen() 934 * Create a unix domain socket, and listen on it. 935 */ 936 int 937 unix_listen(char *path) 938 { 939 int s; 940 941 if ((s = unix_bind(path, 0)) == -1) 942 return -1; 943 if (listen(s, 5) == -1) { 944 close(s); 945 return -1; 946 } 947 if (vflag) 948 report_sock("Listening", NULL, 0, path); 949 950 return s; 951 } 952 953 /* 954 * remote_connect() 955 * Returns a socket connected to a remote host. Properly binds to a local 956 * port or source address if needed. Returns -1 on failure. 957 */ 958 int 959 remote_connect(const char *host, const char *port, struct addrinfo hints, 960 char *ipaddr) 961 { 962 struct addrinfo *res, *res0; 963 int s = -1, error, herr, save_errno; 964 #ifdef SO_BINDANY 965 int on = 1; 966 #endif 967 968 if ((error = getaddrinfo(host, port, &hints, &res0))) 969 errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, 970 port, gai_strerror(error)); 971 972 for (res = res0; res; res = res->ai_next) { 973 if ((s = socket(res->ai_family, res->ai_socktype | 974 SOCK_NONBLOCK, res->ai_protocol)) == -1) 975 continue; 976 977 /* Bind to a local port or source address if specified. */ 978 if (sflag || pflag) { 979 struct addrinfo ahints, *ares; 980 981 #ifdef SO_BINDANY 982 /* try SO_BINDANY, but don't insist */ 983 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 984 #endif 985 memset(&ahints, 0, sizeof(struct addrinfo)); 986 ahints.ai_family = res->ai_family; 987 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 988 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 989 ahints.ai_flags = AI_PASSIVE; 990 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 991 errx(1, "getaddrinfo: %s", gai_strerror(error)); 992 993 if (bind(s, (struct sockaddr *)ares->ai_addr, 994 ares->ai_addrlen) == -1) 995 err(1, "bind failed"); 996 freeaddrinfo(ares); 997 } 998 999 set_common_sockopts(s, res->ai_family); 1000 1001 if (ipaddr != NULL) { 1002 herr = getnameinfo(res->ai_addr, res->ai_addrlen, 1003 ipaddr, NI_MAXHOST, NULL, 0, NI_NUMERICHOST); 1004 switch (herr) { 1005 case 0: 1006 break; 1007 case EAI_SYSTEM: 1008 err(1, "getnameinfo"); 1009 default: 1010 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1011 } 1012 } 1013 1014 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 1015 break; 1016 1017 if (vflag) { 1018 /* only print IP if there is something to report */ 1019 if (nflag || ipaddr == NULL || 1020 (strncmp(host, ipaddr, NI_MAXHOST) == 0)) 1021 warn("connect to %s port %s (%s) failed", host, 1022 port, uflag ? "udp" : "tcp"); 1023 else 1024 warn("connect to %s (%s) port %s (%s) failed", 1025 host, ipaddr, port, uflag ? "udp" : "tcp"); 1026 } 1027 1028 save_errno = errno; 1029 close(s); 1030 errno = save_errno; 1031 s = -1; 1032 } 1033 1034 freeaddrinfo(res0); 1035 1036 return s; 1037 } 1038 1039 int 1040 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 1041 { 1042 struct pollfd pfd; 1043 socklen_t optlen; 1044 int optval; 1045 int ret; 1046 1047 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 1048 pfd.fd = s; 1049 pfd.events = POLLOUT; 1050 if ((ret = poll(&pfd, 1, timeout)) == 1) { 1051 optlen = sizeof(optval); 1052 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 1053 &optval, &optlen)) == 0) { 1054 errno = optval; 1055 ret = optval == 0 ? 0 : -1; 1056 } 1057 } else if (ret == 0) { 1058 errno = ETIMEDOUT; 1059 ret = -1; 1060 } else 1061 err(1, "poll failed"); 1062 } 1063 1064 return ret; 1065 } 1066 1067 /* 1068 * local_listen() 1069 * Returns a socket listening on a local port, binds to specified source 1070 * address. Returns -1 on failure. 1071 */ 1072 int 1073 local_listen(const char *host, const char *port, struct addrinfo hints) 1074 { 1075 struct addrinfo *res, *res0; 1076 int s = -1, save_errno; 1077 #ifdef SO_REUSEPORT 1078 int ret, x = 1; 1079 #endif 1080 int error; 1081 1082 /* Allow nodename to be null. */ 1083 hints.ai_flags |= AI_PASSIVE; 1084 1085 /* 1086 * In the case of binding to a wildcard address 1087 * default to binding to an ipv4 address. 1088 */ 1089 if (host == NULL && hints.ai_family == AF_UNSPEC) 1090 hints.ai_family = AF_INET; 1091 1092 if ((error = getaddrinfo(host, port, &hints, &res0))) 1093 errx(1, "getaddrinfo: %s", gai_strerror(error)); 1094 1095 for (res = res0; res; res = res->ai_next) { 1096 if ((s = socket(res->ai_family, res->ai_socktype, 1097 res->ai_protocol)) == -1) 1098 continue; 1099 1100 #ifdef SO_REUSEPORT 1101 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 1102 if (ret == -1) 1103 err(1, NULL); 1104 #endif 1105 1106 set_common_sockopts(s, res->ai_family); 1107 1108 if (bind(s, (struct sockaddr *)res->ai_addr, 1109 res->ai_addrlen) == 0) 1110 break; 1111 1112 save_errno = errno; 1113 close(s); 1114 errno = save_errno; 1115 s = -1; 1116 } 1117 1118 if (!uflag && s != -1) { 1119 if (listen(s, 1) == -1) 1120 err(1, "listen"); 1121 } 1122 if (vflag && s != -1) { 1123 struct sockaddr_storage ss; 1124 socklen_t len; 1125 1126 len = sizeof(ss); 1127 if (getsockname(s, (struct sockaddr *)&ss, &len) == -1) 1128 err(1, "getsockname"); 1129 report_sock(uflag ? "Bound" : "Listening", 1130 (struct sockaddr *)&ss, len, NULL); 1131 } 1132 1133 freeaddrinfo(res0); 1134 1135 return s; 1136 } 1137 1138 /* 1139 * readwrite() 1140 * Loop that polls on the network file descriptor and stdin. 1141 */ 1142 void 1143 readwrite(int net_fd, struct tls *tls_ctx) 1144 { 1145 struct pollfd pfd[4]; 1146 int stdin_fd = STDIN_FILENO; 1147 int stdout_fd = STDOUT_FILENO; 1148 unsigned char netinbuf[BUFSIZE]; 1149 size_t netinbufpos = 0; 1150 unsigned char stdinbuf[BUFSIZE]; 1151 size_t stdinbufpos = 0; 1152 int n, num_fds; 1153 ssize_t ret; 1154 1155 /* don't read from stdin if requested */ 1156 if (dflag) 1157 stdin_fd = -1; 1158 1159 /* stdin */ 1160 pfd[POLL_STDIN].fd = stdin_fd; 1161 pfd[POLL_STDIN].events = POLLIN; 1162 1163 /* network out */ 1164 pfd[POLL_NETOUT].fd = net_fd; 1165 pfd[POLL_NETOUT].events = 0; 1166 1167 /* network in */ 1168 pfd[POLL_NETIN].fd = net_fd; 1169 pfd[POLL_NETIN].events = POLLIN; 1170 1171 /* stdout */ 1172 pfd[POLL_STDOUT].fd = stdout_fd; 1173 pfd[POLL_STDOUT].events = 0; 1174 1175 while (1) { 1176 /* both inputs are gone, buffers are empty, we are done */ 1177 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1178 stdinbufpos == 0 && netinbufpos == 0) 1179 return; 1180 /* both outputs are gone, we can't continue */ 1181 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) 1182 return; 1183 /* listen and net in gone, queues empty, done */ 1184 if (lflag && pfd[POLL_NETIN].fd == -1 && 1185 stdinbufpos == 0 && netinbufpos == 0) 1186 return; 1187 1188 /* help says -i is for "wait between lines sent". We read and 1189 * write arbitrary amounts of data, and we don't want to start 1190 * scanning for newlines, so this is as good as it gets */ 1191 if (iflag) 1192 sleep(iflag); 1193 1194 /* poll */ 1195 num_fds = poll(pfd, 4, timeout); 1196 1197 /* treat poll errors */ 1198 if (num_fds == -1) 1199 err(1, "polling error"); 1200 1201 /* timeout happened */ 1202 if (num_fds == 0) 1203 return; 1204 1205 /* treat socket error conditions */ 1206 for (n = 0; n < 4; n++) { 1207 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1208 pfd[n].fd = -1; 1209 } 1210 } 1211 /* reading is possible after HUP */ 1212 if (pfd[POLL_STDIN].events & POLLIN && 1213 pfd[POLL_STDIN].revents & POLLHUP && 1214 !(pfd[POLL_STDIN].revents & POLLIN)) 1215 pfd[POLL_STDIN].fd = -1; 1216 1217 if (pfd[POLL_NETIN].events & POLLIN && 1218 pfd[POLL_NETIN].revents & POLLHUP && 1219 !(pfd[POLL_NETIN].revents & POLLIN)) 1220 pfd[POLL_NETIN].fd = -1; 1221 1222 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1223 if (Nflag) 1224 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1225 pfd[POLL_NETOUT].fd = -1; 1226 } 1227 /* if HUP, stop watching stdout */ 1228 if (pfd[POLL_STDOUT].revents & POLLHUP) 1229 pfd[POLL_STDOUT].fd = -1; 1230 /* if no net out, stop watching stdin */ 1231 if (pfd[POLL_NETOUT].fd == -1) 1232 pfd[POLL_STDIN].fd = -1; 1233 /* if no stdout, stop watching net in */ 1234 if (pfd[POLL_STDOUT].fd == -1) { 1235 if (pfd[POLL_NETIN].fd != -1) 1236 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1237 pfd[POLL_NETIN].fd = -1; 1238 } 1239 1240 /* try to read from stdin */ 1241 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1242 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1243 &stdinbufpos, NULL); 1244 if (ret == TLS_WANT_POLLIN) 1245 pfd[POLL_STDIN].events = POLLIN; 1246 else if (ret == TLS_WANT_POLLOUT) 1247 pfd[POLL_STDIN].events = POLLOUT; 1248 else if (ret == 0 || ret == -1) 1249 pfd[POLL_STDIN].fd = -1; 1250 /* read something - poll net out */ 1251 if (stdinbufpos > 0) 1252 pfd[POLL_NETOUT].events = POLLOUT; 1253 /* filled buffer - remove self from polling */ 1254 if (stdinbufpos == BUFSIZE) 1255 pfd[POLL_STDIN].events = 0; 1256 } 1257 /* try to write to network */ 1258 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1259 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1260 &stdinbufpos, tls_ctx); 1261 if (ret == TLS_WANT_POLLIN) 1262 pfd[POLL_NETOUT].events = POLLIN; 1263 else if (ret == TLS_WANT_POLLOUT) 1264 pfd[POLL_NETOUT].events = POLLOUT; 1265 else if (ret == -1) 1266 pfd[POLL_NETOUT].fd = -1; 1267 /* buffer empty - remove self from polling */ 1268 if (stdinbufpos == 0) 1269 pfd[POLL_NETOUT].events = 0; 1270 /* buffer no longer full - poll stdin again */ 1271 if (stdinbufpos < BUFSIZE) 1272 pfd[POLL_STDIN].events = POLLIN; 1273 } 1274 /* try to read from network */ 1275 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1276 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1277 &netinbufpos, tls_ctx); 1278 if (ret == TLS_WANT_POLLIN) 1279 pfd[POLL_NETIN].events = POLLIN; 1280 else if (ret == TLS_WANT_POLLOUT) 1281 pfd[POLL_NETIN].events = POLLOUT; 1282 else if (ret == -1) 1283 pfd[POLL_NETIN].fd = -1; 1284 /* eof on net in - remove from pfd */ 1285 if (ret == 0) { 1286 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1287 pfd[POLL_NETIN].fd = -1; 1288 } 1289 if (recvlimit > 0 && ++recvcount >= recvlimit) { 1290 if (pfd[POLL_NETIN].fd != -1) 1291 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1292 pfd[POLL_NETIN].fd = -1; 1293 pfd[POLL_STDIN].fd = -1; 1294 } 1295 /* read something - poll stdout */ 1296 if (netinbufpos > 0) 1297 pfd[POLL_STDOUT].events = POLLOUT; 1298 /* filled buffer - remove self from polling */ 1299 if (netinbufpos == BUFSIZE) 1300 pfd[POLL_NETIN].events = 0; 1301 /* handle telnet */ 1302 if (tflag) 1303 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1304 netinbufpos); 1305 } 1306 /* try to write to stdout */ 1307 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1308 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1309 &netinbufpos, NULL); 1310 if (ret == TLS_WANT_POLLIN) 1311 pfd[POLL_STDOUT].events = POLLIN; 1312 else if (ret == TLS_WANT_POLLOUT) 1313 pfd[POLL_STDOUT].events = POLLOUT; 1314 else if (ret == -1) 1315 pfd[POLL_STDOUT].fd = -1; 1316 /* buffer empty - remove self from polling */ 1317 if (netinbufpos == 0) 1318 pfd[POLL_STDOUT].events = 0; 1319 /* buffer no longer full - poll net in again */ 1320 if (netinbufpos < BUFSIZE) 1321 pfd[POLL_NETIN].events = POLLIN; 1322 } 1323 1324 /* stdin gone and queue empty? */ 1325 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1326 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1327 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1328 pfd[POLL_NETOUT].fd = -1; 1329 } 1330 /* net in gone and queue empty? */ 1331 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1332 pfd[POLL_STDOUT].fd = -1; 1333 } 1334 } 1335 } 1336 1337 ssize_t 1338 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1339 { 1340 ssize_t n; 1341 ssize_t adjust; 1342 1343 if (tls) { 1344 n = tls_write(tls, buf, *bufpos); 1345 if (n == -1) 1346 errx(1, "tls write failed (%s)", tls_error(tls)); 1347 } else { 1348 n = write(fd, buf, *bufpos); 1349 /* don't treat EAGAIN, EINTR as error */ 1350 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1351 n = TLS_WANT_POLLOUT; 1352 } 1353 if (n <= 0) 1354 return n; 1355 /* adjust buffer */ 1356 adjust = *bufpos - n; 1357 if (adjust > 0) 1358 memmove(buf, buf + n, adjust); 1359 *bufpos -= n; 1360 return n; 1361 } 1362 1363 ssize_t 1364 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1365 { 1366 size_t num = BUFSIZE - *bufpos; 1367 ssize_t n; 1368 1369 if (tls) { 1370 n = tls_read(tls, buf + *bufpos, num); 1371 if (n == -1) 1372 errx(1, "tls read failed (%s)", tls_error(tls)); 1373 } else { 1374 n = read(fd, buf + *bufpos, num); 1375 /* don't treat EAGAIN, EINTR as error */ 1376 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1377 n = TLS_WANT_POLLIN; 1378 } 1379 if (n <= 0) 1380 return n; 1381 *bufpos += n; 1382 return n; 1383 } 1384 1385 /* 1386 * fdpass() 1387 * Pass the connected file descriptor to stdout and exit. 1388 */ 1389 void 1390 fdpass(int nfd) 1391 { 1392 struct msghdr mh; 1393 union { 1394 struct cmsghdr hdr; 1395 char buf[CMSG_SPACE(sizeof(int))]; 1396 } cmsgbuf; 1397 struct cmsghdr *cmsg; 1398 struct iovec iov; 1399 char c = '\0'; 1400 ssize_t r; 1401 struct pollfd pfd; 1402 1403 /* Avoid obvious stupidity */ 1404 if (isatty(STDOUT_FILENO)) 1405 errx(1, "Cannot pass file descriptor to tty"); 1406 1407 memset(&mh, 0, sizeof(mh)); 1408 memset(&cmsgbuf, 0, sizeof(cmsgbuf)); 1409 memset(&iov, 0, sizeof(iov)); 1410 1411 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1412 mh.msg_controllen = sizeof(cmsgbuf.buf); 1413 cmsg = CMSG_FIRSTHDR(&mh); 1414 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1415 cmsg->cmsg_level = SOL_SOCKET; 1416 cmsg->cmsg_type = SCM_RIGHTS; 1417 *(int *)CMSG_DATA(cmsg) = nfd; 1418 1419 iov.iov_base = &c; 1420 iov.iov_len = 1; 1421 mh.msg_iov = &iov; 1422 mh.msg_iovlen = 1; 1423 1424 memset(&pfd, 0, sizeof(pfd)); 1425 pfd.fd = STDOUT_FILENO; 1426 pfd.events = POLLOUT; 1427 for (;;) { 1428 r = sendmsg(STDOUT_FILENO, &mh, 0); 1429 if (r == -1) { 1430 if (errno == EAGAIN || errno == EINTR) { 1431 if (poll(&pfd, 1, -1) == -1) 1432 err(1, "poll"); 1433 continue; 1434 } 1435 err(1, "sendmsg"); 1436 } else if (r != 1) 1437 errx(1, "sendmsg: unexpected return value %zd", r); 1438 else 1439 break; 1440 } 1441 exit(0); 1442 } 1443 1444 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1445 void 1446 atelnet(int nfd, unsigned char *buf, unsigned int size) 1447 { 1448 unsigned char *p, *end; 1449 unsigned char obuf[4]; 1450 1451 if (size < 3) 1452 return; 1453 end = buf + size - 2; 1454 1455 for (p = buf; p < end; p++) { 1456 if (*p != IAC) 1457 continue; 1458 1459 obuf[0] = IAC; 1460 p++; 1461 if ((*p == WILL) || (*p == WONT)) 1462 obuf[1] = DONT; 1463 else if ((*p == DO) || (*p == DONT)) 1464 obuf[1] = WONT; 1465 else 1466 continue; 1467 1468 p++; 1469 obuf[2] = *p; 1470 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1471 warn("Write Error!"); 1472 } 1473 } 1474 1475 int 1476 strtoport(char *portstr, int udp) 1477 { 1478 struct servent *entry; 1479 const char *errstr; 1480 char *proto; 1481 int port = -1; 1482 1483 proto = udp ? "udp" : "tcp"; 1484 1485 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1486 if (errstr == NULL) 1487 return port; 1488 if (errno != EINVAL) 1489 errx(1, "port number %s: %s", errstr, portstr); 1490 if ((entry = getservbyname(portstr, proto)) == NULL) 1491 errx(1, "service \"%s\" unknown", portstr); 1492 return ntohs(entry->s_port); 1493 } 1494 1495 /* 1496 * build_ports() 1497 * Build an array of ports in portlist[], listing each port 1498 * that we should try to connect to. 1499 */ 1500 void 1501 build_ports(char *p) 1502 { 1503 char *n; 1504 int hi, lo, cp; 1505 int x = 0; 1506 1507 if (isdigit((unsigned char)*p) && (n = strchr(p, '-')) != NULL) { 1508 *n = '\0'; 1509 n++; 1510 1511 /* Make sure the ports are in order: lowest->highest. */ 1512 hi = strtoport(n, uflag); 1513 lo = strtoport(p, uflag); 1514 if (lo > hi) { 1515 cp = hi; 1516 hi = lo; 1517 lo = cp; 1518 } 1519 1520 /* 1521 * Initialize portlist with a random permutation. Based on 1522 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1523 */ 1524 if (rflag) { 1525 for (x = 0; x <= hi - lo; x++) { 1526 cp = arc4random_uniform(x + 1); 1527 portlist[x] = portlist[cp]; 1528 if (asprintf(&portlist[cp], "%d", x + lo) == -1) 1529 err(1, "asprintf"); 1530 } 1531 } else { /* Load ports sequentially. */ 1532 for (cp = lo; cp <= hi; cp++) { 1533 if (asprintf(&portlist[x], "%d", cp) == -1) 1534 err(1, "asprintf"); 1535 x++; 1536 } 1537 } 1538 } else { 1539 char *tmp; 1540 1541 hi = strtoport(p, uflag); 1542 if (asprintf(&tmp, "%d", hi) != -1) 1543 portlist[0] = tmp; 1544 else 1545 err(1, NULL); 1546 } 1547 } 1548 1549 /* 1550 * udptest() 1551 * Do a few writes to see if the UDP port is there. 1552 * Fails once PF state table is full. 1553 */ 1554 int 1555 udptest(int s) 1556 { 1557 int i, ret; 1558 1559 for (i = 0; i <= 3; i++) { 1560 if (write(s, "X", 1) == 1) 1561 ret = 1; 1562 else 1563 ret = -1; 1564 } 1565 return ret; 1566 } 1567 1568 void 1569 set_common_sockopts(int s, int af) 1570 { 1571 int x = 1; 1572 1573 #ifdef TCP_MD5SIG 1574 if (Sflag) { 1575 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1576 &x, sizeof(x)) == -1) 1577 err(1, NULL); 1578 } 1579 #endif 1580 if (Dflag) { 1581 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1582 &x, sizeof(x)) == -1) 1583 err(1, NULL); 1584 } 1585 if (Tflag != -1) { 1586 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1587 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1588 err(1, "set IP ToS"); 1589 1590 #ifdef IPV6_TCLASS 1591 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1592 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1593 err(1, "set IPv6 traffic class"); 1594 #else 1595 else if (af == AF_INET6) { 1596 errno = ENOPROTOOPT; 1597 err(1, "set IPv6 traffic class not supported"); 1598 } 1599 #endif 1600 } 1601 if (Iflag) { 1602 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1603 &Iflag, sizeof(Iflag)) == -1) 1604 err(1, "set TCP receive buffer size"); 1605 } 1606 if (Oflag) { 1607 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1608 &Oflag, sizeof(Oflag)) == -1) 1609 err(1, "set TCP send buffer size"); 1610 } 1611 1612 if (ttl != -1) { 1613 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1614 IP_TTL, &ttl, sizeof(ttl))) 1615 err(1, "set IP TTL"); 1616 1617 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1618 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1619 err(1, "set IPv6 unicast hops"); 1620 } 1621 1622 if (minttl != -1) { 1623 #ifdef IP_MINTTL 1624 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1625 IP_MINTTL, &minttl, sizeof(minttl))) 1626 err(1, "set IP min TTL"); 1627 #endif 1628 1629 #ifdef IPV6_MINHOPCOUNT 1630 if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1631 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1632 err(1, "set IPv6 min hop count"); 1633 #endif 1634 } 1635 } 1636 1637 int 1638 process_tos_opt(char *s, int *val) 1639 { 1640 /* DiffServ Codepoints and other TOS mappings */ 1641 const struct toskeywords { 1642 const char *keyword; 1643 int val; 1644 } *t, toskeywords[] = { 1645 { "af11", IPTOS_DSCP_AF11 }, 1646 { "af12", IPTOS_DSCP_AF12 }, 1647 { "af13", IPTOS_DSCP_AF13 }, 1648 { "af21", IPTOS_DSCP_AF21 }, 1649 { "af22", IPTOS_DSCP_AF22 }, 1650 { "af23", IPTOS_DSCP_AF23 }, 1651 { "af31", IPTOS_DSCP_AF31 }, 1652 { "af32", IPTOS_DSCP_AF32 }, 1653 { "af33", IPTOS_DSCP_AF33 }, 1654 { "af41", IPTOS_DSCP_AF41 }, 1655 { "af42", IPTOS_DSCP_AF42 }, 1656 { "af43", IPTOS_DSCP_AF43 }, 1657 { "critical", IPTOS_PREC_CRITIC_ECP }, 1658 { "cs0", IPTOS_DSCP_CS0 }, 1659 { "cs1", IPTOS_DSCP_CS1 }, 1660 { "cs2", IPTOS_DSCP_CS2 }, 1661 { "cs3", IPTOS_DSCP_CS3 }, 1662 { "cs4", IPTOS_DSCP_CS4 }, 1663 { "cs5", IPTOS_DSCP_CS5 }, 1664 { "cs6", IPTOS_DSCP_CS6 }, 1665 { "cs7", IPTOS_DSCP_CS7 }, 1666 { "ef", IPTOS_DSCP_EF }, 1667 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1668 { "lowdelay", IPTOS_LOWDELAY }, 1669 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1670 { "reliability", IPTOS_RELIABILITY }, 1671 { "throughput", IPTOS_THROUGHPUT }, 1672 { NULL, -1 }, 1673 }; 1674 1675 for (t = toskeywords; t->keyword != NULL; t++) { 1676 if (strcmp(s, t->keyword) == 0) { 1677 *val = t->val; 1678 return 1; 1679 } 1680 } 1681 1682 return 0; 1683 } 1684 1685 int 1686 process_tls_opt(char *s, int *flags) 1687 { 1688 size_t len; 1689 char *v; 1690 1691 const struct tlskeywords { 1692 const char *keyword; 1693 int flag; 1694 char **value; 1695 } *t, tlskeywords[] = { 1696 { "ciphers", -1, &tls_ciphers }, 1697 { "clientcert", TLS_CCERT, NULL }, 1698 { "muststaple", TLS_MUSTSTAPLE, NULL }, 1699 { "noverify", TLS_NOVERIFY, NULL }, 1700 { "noname", TLS_NONAME, NULL }, 1701 { "protocols", -1, &tls_protocols }, 1702 { NULL, -1, NULL }, 1703 }; 1704 1705 len = strlen(s); 1706 if ((v = strchr(s, '=')) != NULL) { 1707 len = v - s; 1708 v++; 1709 } 1710 1711 for (t = tlskeywords; t->keyword != NULL; t++) { 1712 if (strlen(t->keyword) == len && 1713 strncmp(s, t->keyword, len) == 0) { 1714 if (t->value != NULL) { 1715 if (v == NULL) 1716 errx(1, "invalid tls value `%s'", s); 1717 *t->value = v; 1718 } else { 1719 *flags |= t->flag; 1720 } 1721 return 1; 1722 } 1723 } 1724 return 0; 1725 } 1726 1727 void 1728 save_peer_cert(struct tls *tls_ctx, FILE *fp) 1729 { 1730 const char *pem; 1731 size_t plen; 1732 1733 if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL) 1734 errx(1, "Can't get peer certificate"); 1735 if (fprintf(fp, "%.*s", (int)plen, pem) < 0) 1736 err(1, "unable to save peer cert"); 1737 if (fflush(fp) != 0) 1738 err(1, "unable to flush peer cert"); 1739 } 1740 1741 void 1742 report_tls(struct tls *tls_ctx, char *host) 1743 { 1744 time_t t; 1745 const char *ocsp_url; 1746 1747 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1748 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1749 fprintf(stderr, "Peer name: %s\n", 1750 tls_expectname ? tls_expectname : host); 1751 if (tls_peer_cert_subject(tls_ctx)) 1752 fprintf(stderr, "Subject: %s\n", 1753 tls_peer_cert_subject(tls_ctx)); 1754 if (tls_peer_cert_issuer(tls_ctx)) 1755 fprintf(stderr, "Issuer: %s\n", 1756 tls_peer_cert_issuer(tls_ctx)); 1757 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1758 fprintf(stderr, "Valid From: %s", ctime(&t)); 1759 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1760 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1761 if (tls_peer_cert_hash(tls_ctx)) 1762 fprintf(stderr, "Cert Hash: %s\n", 1763 tls_peer_cert_hash(tls_ctx)); 1764 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1765 if (ocsp_url != NULL) 1766 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1767 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1768 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1769 fprintf(stderr, "OCSP Stapling: %s\n", 1770 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1771 tls_peer_ocsp_result(tls_ctx)); 1772 fprintf(stderr, 1773 " response_status=%d cert_status=%d crl_reason=%d\n", 1774 tls_peer_ocsp_response_status(tls_ctx), 1775 tls_peer_ocsp_cert_status(tls_ctx), 1776 tls_peer_ocsp_crl_reason(tls_ctx)); 1777 t = tls_peer_ocsp_this_update(tls_ctx); 1778 fprintf(stderr, " this update: %s", 1779 t != -1 ? ctime(&t) : "\n"); 1780 t = tls_peer_ocsp_next_update(tls_ctx); 1781 fprintf(stderr, " next update: %s", 1782 t != -1 ? ctime(&t) : "\n"); 1783 t = tls_peer_ocsp_revocation_time(tls_ctx); 1784 fprintf(stderr, " revocation: %s", 1785 t != -1 ? ctime(&t) : "\n"); 1786 break; 1787 case -1: 1788 break; 1789 default: 1790 fprintf(stderr, 1791 "OCSP Stapling: failure - response_status %d (%s)\n", 1792 tls_peer_ocsp_response_status(tls_ctx), 1793 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1794 tls_peer_ocsp_result(tls_ctx)); 1795 break; 1796 } 1797 } 1798 1799 void 1800 report_sock(const char *msg, const struct sockaddr *sa, socklen_t salen, 1801 char *path) 1802 { 1803 char host[NI_MAXHOST], port[NI_MAXSERV]; 1804 int herr; 1805 int flags = NI_NUMERICSERV; 1806 1807 if (path != NULL) { 1808 fprintf(stderr, "%s on %s\n", msg, path); 1809 return; 1810 } 1811 1812 if (nflag) 1813 flags |= NI_NUMERICHOST; 1814 1815 herr = getnameinfo(sa, salen, host, sizeof(host), port, sizeof(port), 1816 flags); 1817 switch (herr) { 1818 case 0: 1819 break; 1820 case EAI_SYSTEM: 1821 err(1, "getnameinfo"); 1822 default: 1823 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1824 } 1825 1826 fprintf(stderr, "%s on %s %s\n", msg, host, port); 1827 } 1828 1829 void 1830 help(void) 1831 { 1832 usage(0); 1833 fprintf(stderr, "\tCommand Summary:\n\ 1834 \t-4 Use IPv4\n\ 1835 \t-6 Use IPv6\n\ 1836 \t-C certfile Public key file\n\ 1837 \t-c Use TLS\n\ 1838 \t-D Enable the debug socket option\n\ 1839 \t-d Detach from stdin\n\ 1840 \t-e name\t Required name in peer certificate\n\ 1841 \t-F Pass socket fd\n\ 1842 \t-H hash\t Hash string of peer certificate\n\ 1843 \t-h This help text\n\ 1844 \t-I length TCP receive buffer length\n\ 1845 \t-i interval Delay interval for lines sent, ports scanned\n\ 1846 \t-K keyfile Private key file\n\ 1847 \t-k Keep inbound sockets open for multiple connects\n\ 1848 \t-l Listen mode, for inbound connects\n\ 1849 \t-M ttl Outgoing TTL / Hop Limit\n\ 1850 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1851 \t-N Shutdown the network socket after EOF on stdin\n\ 1852 \t-n Suppress name/port resolutions\n\ 1853 \t-O length TCP send buffer length\n\ 1854 \t-o staplefile Staple file\n\ 1855 \t-P proxyuser\tUsername for proxy authentication\n\ 1856 \t-p port\t Specify local port for remote connects\n\ 1857 \t-R CAfile CA bundle\n\ 1858 \t-r Randomize remote ports\n" 1859 #ifdef TCP_MD5SIG 1860 "\t-S Enable the TCP MD5 signature option\n" 1861 #endif 1862 "\t-s sourceaddr Local source address\n\ 1863 \t-T keyword TOS value or TLS options\n\ 1864 \t-t Answer TELNET negotiation\n\ 1865 \t-U Use UNIX domain socket\n\ 1866 \t-u UDP mode\n" 1867 #ifdef SO_RTABLE 1868 "\t-V rtable Specify alternate routing table\n" 1869 #endif 1870 "\t-v Verbose\n\ 1871 \t-W recvlimit Terminate after receiving a number of packets\n\ 1872 \t-w timeout Timeout for connects and final net reads\n\ 1873 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1874 \t-x addr[:port]\tSpecify proxy address and port\n\ 1875 \t-Z Peer certificate file\n\ 1876 \t-z Zero-I/O mode [used for scanning]\n\ 1877 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1878 exit(1); 1879 } 1880 1881 void 1882 usage(int ret) 1883 { 1884 fprintf(stderr, 1885 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1886 "[-H hash] [-I length]\n" 1887 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1888 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1889 "[-R CAfile]\n" 1890 "\t [-s sourceaddr] [-T keyword] [-V rtable] [-W recvlimit] " 1891 "[-w timeout]\n" 1892 "\t [-X proxy_protocol] [-x proxy_address[:port]] " 1893 "[-Z peercertfile]\n" 1894 "\t [destination] [port]\n"); 1895 if (ret) 1896 exit(1); 1897 } 1898