1 /* $OpenBSD: netcat.c,v 1.198 2018/11/09 04:05:14 bluhm Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org> 4 * Copyright (c) 2015 Bob Beck. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * Re-written nc(1) for OpenBSD. Original implementation by 32 * *Hobbit* <hobbit@avian.org>. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 40 #include <netinet/in.h> 41 #include <netinet/tcp.h> 42 #include <netinet/ip.h> 43 #include <arpa/telnet.h> 44 45 #include <err.h> 46 #include <errno.h> 47 #include <limits.h> 48 #include <netdb.h> 49 #include <poll.h> 50 #include <signal.h> 51 #include <stdarg.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <time.h> 56 #include <tls.h> 57 #include <unistd.h> 58 59 #include "atomicio.h" 60 61 #define PORT_MAX 65535 62 #define UNIX_DG_TMP_SOCKET_SIZE 19 63 64 #define POLL_STDIN 0 65 #define POLL_NETOUT 1 66 #define POLL_NETIN 2 67 #define POLL_STDOUT 3 68 #define BUFSIZE 16384 69 70 #define TLS_NOVERIFY (1 << 1) 71 #define TLS_NONAME (1 << 2) 72 #define TLS_CCERT (1 << 3) 73 #define TLS_MUSTSTAPLE (1 << 4) 74 75 /* Command Line Options */ 76 int dflag; /* detached, no stdin */ 77 int Fflag; /* fdpass sock to stdout */ 78 unsigned int iflag; /* Interval Flag */ 79 int kflag; /* More than one connect */ 80 int lflag; /* Bind to local port */ 81 int Nflag; /* shutdown() network socket */ 82 int nflag; /* Don't do name look up */ 83 char *Pflag; /* Proxy username */ 84 char *pflag; /* Localport flag */ 85 int rflag; /* Random ports flag */ 86 char *sflag; /* Source Address */ 87 int tflag; /* Telnet Emulation */ 88 int uflag; /* UDP - Default to TCP */ 89 int vflag; /* Verbosity */ 90 int xflag; /* Socks proxy */ 91 int zflag; /* Port Scan Flag */ 92 int Dflag; /* sodebug */ 93 int Iflag; /* TCP receive buffer size */ 94 int Oflag; /* TCP send buffer size */ 95 int Sflag; /* TCP MD5 signature option */ 96 int Tflag = -1; /* IP Type of Service */ 97 int rtableid = -1; 98 99 int usetls; /* use TLS */ 100 char *Cflag; /* Public cert file */ 101 char *Kflag; /* Private key file */ 102 char *oflag; /* OCSP stapling file */ 103 char *Rflag = TLS_CA_CERT_FILE; /* Root CA file */ 104 int tls_cachanged; /* Using non-default CA file */ 105 int TLSopt; /* TLS options */ 106 char *tls_expectname; /* required name in peer cert */ 107 char *tls_expecthash; /* required hash of peer cert */ 108 char *tls_ciphers; /* TLS ciphers */ 109 char *tls_protocols; /* TLS protocols */ 110 FILE *Zflag; /* file to save peer cert */ 111 112 int recvcount, recvlimit; 113 int timeout = -1; 114 int family = AF_UNSPEC; 115 char *portlist[PORT_MAX+1]; 116 char *unix_dg_tmp_socket; 117 int ttl = -1; 118 int minttl = -1; 119 120 void atelnet(int, unsigned char *, unsigned int); 121 int strtoport(char *portstr, int udp); 122 void build_ports(char *); 123 void help(void) __attribute__((noreturn)); 124 int local_listen(const char *, const char *, struct addrinfo); 125 void readwrite(int, struct tls *); 126 void fdpass(int nfd) __attribute__((noreturn)); 127 int remote_connect(const char *, const char *, struct addrinfo); 128 int timeout_tls(int, struct tls *, int (*)(struct tls *)); 129 int timeout_connect(int, const struct sockaddr *, socklen_t); 130 int socks_connect(const char *, const char *, struct addrinfo, 131 const char *, const char *, struct addrinfo, int, const char *); 132 int udptest(int); 133 int unix_bind(char *, int); 134 int unix_connect(char *); 135 int unix_listen(char *); 136 void set_common_sockopts(int, int); 137 int process_tos_opt(char *, int *); 138 int process_tls_opt(char *, int *); 139 void save_peer_cert(struct tls *_tls_ctx, FILE *_fp); 140 void report_sock(const char *, const struct sockaddr *, socklen_t, char *); 141 void report_tls(struct tls *tls_ctx, char * host); 142 void usage(int); 143 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 144 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 145 void tls_setup_client(struct tls *, int, char *); 146 struct tls *tls_setup_server(struct tls *, int, char *); 147 148 int 149 main(int argc, char *argv[]) 150 { 151 int ch, s = -1, ret, socksv; 152 char *host, *uport; 153 struct addrinfo hints; 154 struct servent *sv; 155 socklen_t len; 156 struct sockaddr_storage cliaddr; 157 char *proxy = NULL, *proxyport = NULL; 158 const char *errstr; 159 struct addrinfo proxyhints; 160 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 161 struct tls_config *tls_cfg = NULL; 162 struct tls *tls_ctx = NULL; 163 uint32_t protocols; 164 165 ret = 1; 166 socksv = 5; 167 host = NULL; 168 uport = NULL; 169 sv = NULL; 170 171 signal(SIGPIPE, SIG_IGN); 172 173 while ((ch = getopt(argc, argv, 174 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z")) 175 != -1) { 176 switch (ch) { 177 case '4': 178 family = AF_INET; 179 break; 180 case '6': 181 family = AF_INET6; 182 break; 183 case 'U': 184 family = AF_UNIX; 185 break; 186 case 'X': 187 if (strcasecmp(optarg, "connect") == 0) 188 socksv = -1; /* HTTP proxy CONNECT */ 189 else if (strcmp(optarg, "4") == 0) 190 socksv = 4; /* SOCKS v.4 */ 191 else if (strcmp(optarg, "5") == 0) 192 socksv = 5; /* SOCKS v.5 */ 193 else 194 errx(1, "unsupported proxy protocol"); 195 break; 196 case 'C': 197 Cflag = optarg; 198 break; 199 case 'c': 200 usetls = 1; 201 break; 202 case 'd': 203 dflag = 1; 204 break; 205 case 'e': 206 tls_expectname = optarg; 207 break; 208 case 'F': 209 Fflag = 1; 210 break; 211 case 'H': 212 tls_expecthash = optarg; 213 break; 214 case 'h': 215 help(); 216 break; 217 case 'i': 218 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 219 if (errstr) 220 errx(1, "interval %s: %s", errstr, optarg); 221 break; 222 case 'K': 223 Kflag = optarg; 224 break; 225 case 'k': 226 kflag = 1; 227 break; 228 case 'l': 229 lflag = 1; 230 break; 231 case 'M': 232 ttl = strtonum(optarg, 0, 255, &errstr); 233 if (errstr) 234 errx(1, "ttl is %s", errstr); 235 break; 236 case 'm': 237 minttl = strtonum(optarg, 0, 255, &errstr); 238 if (errstr) 239 errx(1, "minttl is %s", errstr); 240 break; 241 case 'N': 242 Nflag = 1; 243 break; 244 case 'n': 245 nflag = 1; 246 break; 247 case 'P': 248 Pflag = optarg; 249 break; 250 case 'p': 251 pflag = optarg; 252 break; 253 case 'R': 254 tls_cachanged = 1; 255 Rflag = optarg; 256 break; 257 case 'r': 258 rflag = 1; 259 break; 260 case 's': 261 sflag = optarg; 262 break; 263 case 't': 264 tflag = 1; 265 break; 266 case 'u': 267 uflag = 1; 268 break; 269 case 'V': 270 rtableid = (int)strtonum(optarg, 0, 271 RT_TABLEID_MAX, &errstr); 272 if (errstr) 273 errx(1, "rtable %s: %s", errstr, optarg); 274 break; 275 case 'v': 276 vflag = 1; 277 break; 278 case 'W': 279 recvlimit = strtonum(optarg, 1, INT_MAX, &errstr); 280 if (errstr) 281 errx(1, "receive limit %s: %s", errstr, optarg); 282 break; 283 case 'w': 284 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 285 if (errstr) 286 errx(1, "timeout %s: %s", errstr, optarg); 287 timeout *= 1000; 288 break; 289 case 'x': 290 xflag = 1; 291 if ((proxy = strdup(optarg)) == NULL) 292 err(1, NULL); 293 break; 294 case 'Z': 295 if (strcmp(optarg, "-") == 0) 296 Zflag = stderr; 297 else if ((Zflag = fopen(optarg, "w")) == NULL) 298 err(1, "can't open %s", optarg); 299 break; 300 case 'z': 301 zflag = 1; 302 break; 303 case 'D': 304 Dflag = 1; 305 break; 306 case 'I': 307 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 308 if (errstr != NULL) 309 errx(1, "TCP receive window %s: %s", 310 errstr, optarg); 311 break; 312 case 'O': 313 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 314 if (errstr != NULL) 315 errx(1, "TCP send window %s: %s", 316 errstr, optarg); 317 break; 318 case 'o': 319 oflag = optarg; 320 break; 321 case 'S': 322 Sflag = 1; 323 break; 324 case 'T': 325 errstr = NULL; 326 errno = 0; 327 if (process_tls_opt(optarg, &TLSopt)) 328 break; 329 if (process_tos_opt(optarg, &Tflag)) 330 break; 331 if (strlen(optarg) > 1 && optarg[0] == '0' && 332 optarg[1] == 'x') 333 Tflag = (int)strtol(optarg, NULL, 16); 334 else 335 Tflag = (int)strtonum(optarg, 0, 255, 336 &errstr); 337 if (Tflag < 0 || Tflag > 255 || errstr || errno) 338 errx(1, "illegal tos/tls value %s", optarg); 339 break; 340 default: 341 usage(1); 342 } 343 } 344 argc -= optind; 345 argv += optind; 346 347 if (rtableid >= 0) 348 if (setrtable(rtableid) == -1) 349 err(1, "setrtable"); 350 351 /* Cruft to make sure options are clean, and used properly. */ 352 if (argv[0] && !argv[1] && family == AF_UNIX) { 353 host = argv[0]; 354 uport = NULL; 355 } else if (argv[0] && !argv[1]) { 356 if (!lflag) 357 usage(1); 358 uport = argv[0]; 359 host = NULL; 360 } else if (argv[0] && argv[1]) { 361 host = argv[0]; 362 uport = argv[1]; 363 } else 364 usage(1); 365 366 if (usetls) { 367 if (Cflag && unveil(Cflag, "r") == -1) 368 err(1, "unveil"); 369 if (unveil(Rflag, "r") == -1) 370 err(1, "unveil"); 371 if (Kflag && unveil(Kflag, "r") == -1) 372 err(1, "unveil"); 373 if (oflag && unveil(oflag, "r") == -1) 374 err(1, "unveil"); 375 } else { 376 if (family == AF_UNIX) { 377 if (unveil(host, "rwc") == -1) 378 err(1, "unveil"); 379 if (uflag && !lflag) { 380 if (unveil(sflag ? sflag : "/tmp", "rwc") == -1) 381 err(1, "unveil"); 382 } 383 } else { 384 if (unveil("/", "") == -1) 385 err(1, "unveil"); 386 } 387 } 388 389 if (family == AF_UNIX) { 390 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 391 err(1, "pledge"); 392 } else if (Fflag && Pflag) { 393 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 394 err(1, "pledge"); 395 } else if (Fflag) { 396 if (pledge("stdio inet dns sendfd", NULL) == -1) 397 err(1, "pledge"); 398 } else if (Pflag && usetls) { 399 if (pledge("stdio rpath inet dns tty", NULL) == -1) 400 err(1, "pledge"); 401 } else if (Pflag) { 402 if (pledge("stdio inet dns tty", NULL) == -1) 403 err(1, "pledge"); 404 } else if (usetls) { 405 if (pledge("stdio rpath inet dns", NULL) == -1) 406 err(1, "pledge"); 407 } else if (pledge("stdio inet dns", NULL) == -1) 408 err(1, "pledge"); 409 410 if (lflag && sflag) 411 errx(1, "cannot use -s and -l"); 412 if (lflag && pflag) 413 errx(1, "cannot use -p and -l"); 414 if (lflag && zflag) 415 errx(1, "cannot use -z and -l"); 416 if (!lflag && kflag) 417 errx(1, "must use -l with -k"); 418 if (uflag && usetls) 419 errx(1, "cannot use -c and -u"); 420 if ((family == AF_UNIX) && usetls) 421 errx(1, "cannot use -c and -U"); 422 if ((family == AF_UNIX) && Fflag) 423 errx(1, "cannot use -F and -U"); 424 if (Fflag && usetls) 425 errx(1, "cannot use -c and -F"); 426 if (TLSopt && !usetls) 427 errx(1, "you must specify -c to use TLS options"); 428 if (Cflag && !usetls) 429 errx(1, "you must specify -c to use -C"); 430 if (Kflag && !usetls) 431 errx(1, "you must specify -c to use -K"); 432 if (Zflag && !usetls) 433 errx(1, "you must specify -c to use -Z"); 434 if (oflag && !Cflag) 435 errx(1, "you must specify -C to use -o"); 436 if (tls_cachanged && !usetls) 437 errx(1, "you must specify -c to use -R"); 438 if (tls_expecthash && !usetls) 439 errx(1, "you must specify -c to use -H"); 440 if (tls_expectname && !usetls) 441 errx(1, "you must specify -c to use -e"); 442 443 /* Get name of temporary socket for unix datagram client */ 444 if ((family == AF_UNIX) && uflag && !lflag) { 445 if (sflag) { 446 unix_dg_tmp_socket = sflag; 447 } else { 448 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 449 UNIX_DG_TMP_SOCKET_SIZE); 450 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 451 err(1, "mktemp"); 452 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 453 } 454 } 455 456 /* Initialize addrinfo structure. */ 457 if (family != AF_UNIX) { 458 memset(&hints, 0, sizeof(struct addrinfo)); 459 hints.ai_family = family; 460 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 461 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 462 if (nflag) 463 hints.ai_flags |= AI_NUMERICHOST; 464 } 465 466 if (xflag) { 467 if (uflag) 468 errx(1, "no proxy support for UDP mode"); 469 470 if (lflag) 471 errx(1, "no proxy support for listen"); 472 473 if (family == AF_UNIX) 474 errx(1, "no proxy support for unix sockets"); 475 476 if (sflag) 477 errx(1, "no proxy support for local source address"); 478 479 if (*proxy == '[') { 480 ++proxy; 481 proxyport = strchr(proxy, ']'); 482 if (proxyport == NULL) 483 errx(1, "missing closing bracket in proxy"); 484 *proxyport++ = '\0'; 485 if (*proxyport == '\0') 486 /* Use default proxy port. */ 487 proxyport = NULL; 488 else { 489 if (*proxyport == ':') 490 ++proxyport; 491 else 492 errx(1, "garbage proxy port delimiter"); 493 } 494 } else { 495 proxyport = strrchr(proxy, ':'); 496 if (proxyport != NULL) 497 *proxyport++ = '\0'; 498 } 499 500 memset(&proxyhints, 0, sizeof(struct addrinfo)); 501 proxyhints.ai_family = family; 502 proxyhints.ai_socktype = SOCK_STREAM; 503 proxyhints.ai_protocol = IPPROTO_TCP; 504 if (nflag) 505 proxyhints.ai_flags |= AI_NUMERICHOST; 506 } 507 508 if (usetls) { 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 (tls_config_parse_protocols(&protocols, tls_protocols) == -1) 520 errx(1, "invalid TLS protocols `%s'", tls_protocols); 521 if (tls_config_set_protocols(tls_cfg, protocols) == -1) 522 errx(1, "%s", tls_config_error(tls_cfg)); 523 if (tls_config_set_ciphers(tls_cfg, tls_ciphers) == -1) 524 errx(1, "%s", tls_config_error(tls_cfg)); 525 if (!lflag && (TLSopt & TLS_CCERT)) 526 errx(1, "clientcert is only valid with -l"); 527 if (TLSopt & TLS_NONAME) 528 tls_config_insecure_noverifyname(tls_cfg); 529 if (TLSopt & TLS_NOVERIFY) { 530 if (tls_expecthash != NULL) 531 errx(1, "-H and -T noverify may not be used " 532 "together"); 533 tls_config_insecure_noverifycert(tls_cfg); 534 } 535 if (TLSopt & TLS_MUSTSTAPLE) 536 tls_config_ocsp_require_stapling(tls_cfg); 537 538 if (Pflag) { 539 if (pledge("stdio inet dns tty", NULL) == -1) 540 err(1, "pledge"); 541 } else if (pledge("stdio inet dns", NULL) == -1) 542 err(1, "pledge"); 543 } 544 if (lflag) { 545 ret = 0; 546 547 if (family == AF_UNIX) { 548 if (uflag) 549 s = unix_bind(host, 0); 550 else 551 s = unix_listen(host); 552 } 553 554 if (usetls) { 555 tls_config_verify_client_optional(tls_cfg); 556 if ((tls_ctx = tls_server()) == NULL) 557 errx(1, "tls server creation failed"); 558 if (tls_configure(tls_ctx, tls_cfg) == -1) 559 errx(1, "tls configuration failed (%s)", 560 tls_error(tls_ctx)); 561 } 562 /* Allow only one connection at a time, but stay alive. */ 563 for (;;) { 564 if (family != AF_UNIX) { 565 if (s != -1) 566 close(s); 567 s = local_listen(host, uport, hints); 568 } 569 if (s < 0) 570 err(1, NULL); 571 if (uflag && kflag) { 572 /* 573 * For UDP and -k, don't connect the socket, 574 * let it receive datagrams from multiple 575 * socket pairs. 576 */ 577 readwrite(s, NULL); 578 } else if (uflag && !kflag) { 579 /* 580 * For UDP and not -k, we will use recvfrom() 581 * initially to wait for a caller, then use 582 * the regular functions to talk to the caller. 583 */ 584 int rv; 585 char buf[2048]; 586 struct sockaddr_storage z; 587 588 len = sizeof(z); 589 rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK, 590 (struct sockaddr *)&z, &len); 591 if (rv < 0) 592 err(1, "recvfrom"); 593 594 rv = connect(s, (struct sockaddr *)&z, len); 595 if (rv < 0) 596 err(1, "connect"); 597 598 if (vflag) 599 report_sock("Connection received", 600 (struct sockaddr *)&z, len, NULL); 601 602 readwrite(s, NULL); 603 } else { 604 struct tls *tls_cctx = NULL; 605 int connfd; 606 607 len = sizeof(cliaddr); 608 connfd = accept4(s, (struct sockaddr *)&cliaddr, 609 &len, SOCK_NONBLOCK); 610 if (connfd == -1) { 611 /* For now, all errnos are fatal */ 612 err(1, "accept"); 613 } 614 if (vflag) 615 report_sock("Connection received", 616 (struct sockaddr *)&cliaddr, len, 617 family == AF_UNIX ? host : NULL); 618 if ((usetls) && 619 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 620 readwrite(connfd, tls_cctx); 621 if (!usetls) 622 readwrite(connfd, NULL); 623 if (tls_cctx) 624 timeout_tls(s, tls_cctx, tls_close); 625 close(connfd); 626 tls_free(tls_cctx); 627 } 628 if (family == AF_UNIX && uflag) { 629 if (connect(s, NULL, 0) < 0) 630 err(1, "connect"); 631 } 632 633 if (!kflag) 634 break; 635 } 636 } else if (family == AF_UNIX) { 637 ret = 0; 638 639 if ((s = unix_connect(host)) > 0) { 640 if (!zflag) 641 readwrite(s, NULL); 642 close(s); 643 } else { 644 warn("%s", host); 645 ret = 1; 646 } 647 648 if (uflag) 649 unlink(unix_dg_tmp_socket); 650 return ret; 651 652 } else { 653 int i = 0; 654 655 /* Construct the portlist[] array. */ 656 build_ports(uport); 657 658 /* Cycle through portlist, connecting to each port. */ 659 for (s = -1, i = 0; portlist[i] != NULL; i++) { 660 if (s != -1) 661 close(s); 662 tls_free(tls_ctx); 663 tls_ctx = NULL; 664 665 if (usetls) { 666 if ((tls_ctx = tls_client()) == NULL) 667 errx(1, "tls client creation failed"); 668 if (tls_configure(tls_ctx, tls_cfg) == -1) 669 errx(1, "tls configuration failed (%s)", 670 tls_error(tls_ctx)); 671 } 672 if (xflag) 673 s = socks_connect(host, portlist[i], hints, 674 proxy, proxyport, proxyhints, socksv, 675 Pflag); 676 else 677 s = remote_connect(host, portlist[i], hints); 678 679 if (s == -1) 680 continue; 681 682 ret = 0; 683 if (vflag || zflag) { 684 /* For UDP, make sure we are connected. */ 685 if (uflag) { 686 if (udptest(s) == -1) { 687 ret = 1; 688 continue; 689 } 690 } 691 692 /* Don't look up port if -n. */ 693 if (nflag) 694 sv = NULL; 695 else { 696 sv = getservbyport( 697 ntohs(atoi(portlist[i])), 698 uflag ? "udp" : "tcp"); 699 } 700 701 fprintf(stderr, 702 "Connection to %s %s port [%s/%s] " 703 "succeeded!\n", host, portlist[i], 704 uflag ? "udp" : "tcp", 705 sv ? sv->s_name : "*"); 706 } 707 if (Fflag) 708 fdpass(s); 709 else { 710 if (usetls) 711 tls_setup_client(tls_ctx, s, host); 712 if (!zflag) 713 readwrite(s, tls_ctx); 714 if (tls_ctx) 715 timeout_tls(s, tls_ctx, tls_close); 716 } 717 } 718 } 719 720 if (s != -1) 721 close(s); 722 tls_free(tls_ctx); 723 tls_config_free(tls_cfg); 724 725 return ret; 726 } 727 728 /* 729 * unix_bind() 730 * Returns a unix socket bound to the given path 731 */ 732 int 733 unix_bind(char *path, int flags) 734 { 735 struct sockaddr_un s_un; 736 int s, save_errno; 737 738 /* Create unix domain socket. */ 739 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 740 0)) < 0) 741 return -1; 742 743 memset(&s_un, 0, sizeof(struct sockaddr_un)); 744 s_un.sun_family = AF_UNIX; 745 746 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 747 sizeof(s_un.sun_path)) { 748 close(s); 749 errno = ENAMETOOLONG; 750 return -1; 751 } 752 753 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 754 save_errno = errno; 755 close(s); 756 errno = save_errno; 757 return -1; 758 } 759 if (vflag) 760 report_sock("Bound", NULL, 0, path); 761 762 return s; 763 } 764 765 int 766 timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) 767 { 768 struct pollfd pfd; 769 int ret; 770 771 while ((ret = (*func)(tls_ctx)) != 0) { 772 if (ret == TLS_WANT_POLLIN) 773 pfd.events = POLLIN; 774 else if (ret == TLS_WANT_POLLOUT) 775 pfd.events = POLLOUT; 776 else 777 break; 778 pfd.fd = s; 779 if ((ret = poll(&pfd, 1, timeout)) == 1) 780 continue; 781 else if (ret == 0) { 782 errno = ETIMEDOUT; 783 ret = -1; 784 break; 785 } else 786 err(1, "poll failed"); 787 } 788 789 return ret; 790 } 791 792 void 793 tls_setup_client(struct tls *tls_ctx, int s, char *host) 794 { 795 const char *errstr; 796 797 if (tls_connect_socket(tls_ctx, s, 798 tls_expectname ? tls_expectname : host) == -1) { 799 errx(1, "tls connection failed (%s)", 800 tls_error(tls_ctx)); 801 } 802 if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { 803 if ((errstr = tls_error(tls_ctx)) == NULL) 804 errstr = strerror(errno); 805 errx(1, "tls handshake failed (%s)", errstr); 806 } 807 if (vflag) 808 report_tls(tls_ctx, host); 809 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 810 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 811 errx(1, "peer certificate is not %s", tls_expecthash); 812 if (Zflag) { 813 save_peer_cert(tls_ctx, Zflag); 814 if (Zflag != stderr && (fclose(Zflag) != 0)) 815 err(1, "fclose failed saving peer cert"); 816 } 817 } 818 819 struct tls * 820 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 821 { 822 struct tls *tls_cctx; 823 const char *errstr; 824 825 if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { 826 warnx("tls accept failed (%s)", tls_error(tls_ctx)); 827 } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { 828 if ((errstr = tls_error(tls_cctx)) == NULL) 829 errstr = strerror(errno); 830 warnx("tls handshake failed (%s)", errstr); 831 } else { 832 int gotcert = tls_peer_cert_provided(tls_cctx); 833 834 if (vflag && gotcert) 835 report_tls(tls_cctx, host); 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 } 851 852 /* 853 * unix_connect() 854 * Returns a socket connected to a local unix socket. Returns -1 on failure. 855 */ 856 int 857 unix_connect(char *path) 858 { 859 struct sockaddr_un s_un; 860 int s, save_errno; 861 862 if (uflag) { 863 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 864 return -1; 865 } else { 866 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 867 return -1; 868 } 869 870 memset(&s_un, 0, sizeof(struct sockaddr_un)); 871 s_un.sun_family = AF_UNIX; 872 873 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 874 sizeof(s_un.sun_path)) { 875 close(s); 876 errno = ENAMETOOLONG; 877 return -1; 878 } 879 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 880 save_errno = errno; 881 close(s); 882 errno = save_errno; 883 return -1; 884 } 885 return s; 886 887 } 888 889 /* 890 * unix_listen() 891 * Create a unix domain socket, and listen on it. 892 */ 893 int 894 unix_listen(char *path) 895 { 896 int s; 897 898 if ((s = unix_bind(path, 0)) < 0) 899 return -1; 900 if (listen(s, 5) < 0) { 901 close(s); 902 return -1; 903 } 904 if (vflag) 905 report_sock("Listening", NULL, 0, path); 906 907 return s; 908 } 909 910 /* 911 * remote_connect() 912 * Returns a socket connected to a remote host. Properly binds to a local 913 * port or source address if needed. Returns -1 on failure. 914 */ 915 int 916 remote_connect(const char *host, const char *port, struct addrinfo hints) 917 { 918 struct addrinfo *res, *res0; 919 int s = -1, error, on = 1, save_errno; 920 921 if ((error = getaddrinfo(host, port, &hints, &res0))) 922 errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, 923 port, 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 /* try SO_BINDANY, but don't insist */ 935 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 936 memset(&ahints, 0, sizeof(struct addrinfo)); 937 ahints.ai_family = res->ai_family; 938 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 939 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 940 ahints.ai_flags = AI_PASSIVE; 941 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 942 errx(1, "getaddrinfo: %s", gai_strerror(error)); 943 944 if (bind(s, (struct sockaddr *)ares->ai_addr, 945 ares->ai_addrlen) < 0) 946 err(1, "bind failed"); 947 freeaddrinfo(ares); 948 } 949 950 set_common_sockopts(s, res->ai_family); 951 952 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 953 break; 954 if (vflag) 955 warn("connect to %s port %s (%s) failed", host, port, 956 uflag ? "udp" : "tcp"); 957 958 save_errno = errno; 959 close(s); 960 errno = save_errno; 961 s = -1; 962 } 963 964 freeaddrinfo(res0); 965 966 return s; 967 } 968 969 int 970 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 971 { 972 struct pollfd pfd; 973 socklen_t optlen; 974 int optval; 975 int ret; 976 977 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 978 pfd.fd = s; 979 pfd.events = POLLOUT; 980 if ((ret = poll(&pfd, 1, timeout)) == 1) { 981 optlen = sizeof(optval); 982 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 983 &optval, &optlen)) == 0) { 984 errno = optval; 985 ret = optval == 0 ? 0 : -1; 986 } 987 } else if (ret == 0) { 988 errno = ETIMEDOUT; 989 ret = -1; 990 } else 991 err(1, "poll failed"); 992 } 993 994 return ret; 995 } 996 997 /* 998 * local_listen() 999 * Returns a socket listening on a local port, binds to specified source 1000 * address. Returns -1 on failure. 1001 */ 1002 int 1003 local_listen(const char *host, const char *port, struct addrinfo hints) 1004 { 1005 struct addrinfo *res, *res0; 1006 int s = -1, ret, x = 1, save_errno; 1007 int error; 1008 1009 /* Allow nodename to be null. */ 1010 hints.ai_flags |= AI_PASSIVE; 1011 1012 /* 1013 * In the case of binding to a wildcard address 1014 * default to binding to an ipv4 address. 1015 */ 1016 if (host == NULL && hints.ai_family == AF_UNSPEC) 1017 hints.ai_family = AF_INET; 1018 1019 if ((error = getaddrinfo(host, port, &hints, &res0))) 1020 errx(1, "getaddrinfo: %s", gai_strerror(error)); 1021 1022 for (res = res0; res; res = res->ai_next) { 1023 if ((s = socket(res->ai_family, res->ai_socktype, 1024 res->ai_protocol)) < 0) 1025 continue; 1026 1027 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 1028 if (ret == -1) 1029 err(1, NULL); 1030 1031 set_common_sockopts(s, res->ai_family); 1032 1033 if (bind(s, (struct sockaddr *)res->ai_addr, 1034 res->ai_addrlen) == 0) 1035 break; 1036 1037 save_errno = errno; 1038 close(s); 1039 errno = save_errno; 1040 s = -1; 1041 } 1042 1043 if (!uflag && s != -1) { 1044 if (listen(s, 1) < 0) 1045 err(1, "listen"); 1046 } 1047 if (vflag && s != -1) { 1048 struct sockaddr_storage ss; 1049 socklen_t len; 1050 1051 len = sizeof(ss); 1052 if (getsockname(s, (struct sockaddr *)&ss, &len) == -1) 1053 err(1, "getsockname"); 1054 report_sock(uflag ? "Bound" : "Listening", 1055 (struct sockaddr *)&ss, len, NULL); 1056 } 1057 1058 freeaddrinfo(res0); 1059 1060 return s; 1061 } 1062 1063 /* 1064 * readwrite() 1065 * Loop that polls on the network file descriptor and stdin. 1066 */ 1067 void 1068 readwrite(int net_fd, struct tls *tls_ctx) 1069 { 1070 struct pollfd pfd[4]; 1071 int stdin_fd = STDIN_FILENO; 1072 int stdout_fd = STDOUT_FILENO; 1073 unsigned char netinbuf[BUFSIZE]; 1074 size_t netinbufpos = 0; 1075 unsigned char stdinbuf[BUFSIZE]; 1076 size_t stdinbufpos = 0; 1077 int n, num_fds; 1078 ssize_t ret; 1079 1080 /* don't read from stdin if requested */ 1081 if (dflag) 1082 stdin_fd = -1; 1083 1084 /* stdin */ 1085 pfd[POLL_STDIN].fd = stdin_fd; 1086 pfd[POLL_STDIN].events = POLLIN; 1087 1088 /* network out */ 1089 pfd[POLL_NETOUT].fd = net_fd; 1090 pfd[POLL_NETOUT].events = 0; 1091 1092 /* network in */ 1093 pfd[POLL_NETIN].fd = net_fd; 1094 pfd[POLL_NETIN].events = POLLIN; 1095 1096 /* stdout */ 1097 pfd[POLL_STDOUT].fd = stdout_fd; 1098 pfd[POLL_STDOUT].events = 0; 1099 1100 while (1) { 1101 /* both inputs are gone, buffers are empty, we are done */ 1102 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1103 stdinbufpos == 0 && netinbufpos == 0) 1104 return; 1105 /* both outputs are gone, we can't continue */ 1106 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) 1107 return; 1108 /* listen and net in gone, queues empty, done */ 1109 if (lflag && pfd[POLL_NETIN].fd == -1 && 1110 stdinbufpos == 0 && netinbufpos == 0) 1111 return; 1112 1113 /* help says -i is for "wait between lines sent". We read and 1114 * write arbitrary amounts of data, and we don't want to start 1115 * scanning for newlines, so this is as good as it gets */ 1116 if (iflag) 1117 sleep(iflag); 1118 1119 /* poll */ 1120 num_fds = poll(pfd, 4, timeout); 1121 1122 /* treat poll errors */ 1123 if (num_fds == -1) 1124 err(1, "polling error"); 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 if (recvlimit > 0 && ++recvcount >= recvlimit) { 1215 if (pfd[POLL_NETIN].fd != -1) 1216 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1217 pfd[POLL_NETIN].fd = -1; 1218 pfd[POLL_STDIN].fd = -1; 1219 } 1220 /* read something - poll stdout */ 1221 if (netinbufpos > 0) 1222 pfd[POLL_STDOUT].events = POLLOUT; 1223 /* filled buffer - remove self from polling */ 1224 if (netinbufpos == BUFSIZE) 1225 pfd[POLL_NETIN].events = 0; 1226 /* handle telnet */ 1227 if (tflag) 1228 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1229 netinbufpos); 1230 } 1231 /* try to write to stdout */ 1232 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1233 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1234 &netinbufpos, NULL); 1235 if (ret == TLS_WANT_POLLIN) 1236 pfd[POLL_STDOUT].events = POLLIN; 1237 else if (ret == TLS_WANT_POLLOUT) 1238 pfd[POLL_STDOUT].events = POLLOUT; 1239 else if (ret == -1) 1240 pfd[POLL_STDOUT].fd = -1; 1241 /* buffer empty - remove self from polling */ 1242 if (netinbufpos == 0) 1243 pfd[POLL_STDOUT].events = 0; 1244 /* buffer no longer full - poll net in again */ 1245 if (netinbufpos < BUFSIZE) 1246 pfd[POLL_NETIN].events = POLLIN; 1247 } 1248 1249 /* stdin gone and queue empty? */ 1250 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1251 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1252 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1253 pfd[POLL_NETOUT].fd = -1; 1254 } 1255 /* net in gone and queue empty? */ 1256 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1257 pfd[POLL_STDOUT].fd = -1; 1258 } 1259 } 1260 } 1261 1262 ssize_t 1263 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1264 { 1265 ssize_t n; 1266 ssize_t adjust; 1267 1268 if (tls) 1269 n = tls_write(tls, buf, *bufpos); 1270 else { 1271 n = write(fd, buf, *bufpos); 1272 /* don't treat EAGAIN, EINTR as error */ 1273 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1274 n = TLS_WANT_POLLOUT; 1275 } 1276 if (n <= 0) 1277 return n; 1278 /* adjust buffer */ 1279 adjust = *bufpos - n; 1280 if (adjust > 0) 1281 memmove(buf, buf + n, adjust); 1282 *bufpos -= n; 1283 return n; 1284 } 1285 1286 ssize_t 1287 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1288 { 1289 size_t num = BUFSIZE - *bufpos; 1290 ssize_t n; 1291 1292 if (tls) 1293 n = tls_read(tls, buf + *bufpos, num); 1294 else { 1295 n = read(fd, buf + *bufpos, num); 1296 /* don't treat EAGAIN, EINTR as error */ 1297 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1298 n = TLS_WANT_POLLIN; 1299 } 1300 if (n <= 0) 1301 return n; 1302 *bufpos += n; 1303 return n; 1304 } 1305 1306 /* 1307 * fdpass() 1308 * Pass the connected file descriptor to stdout and exit. 1309 */ 1310 void 1311 fdpass(int nfd) 1312 { 1313 struct msghdr mh; 1314 union { 1315 struct cmsghdr hdr; 1316 char buf[CMSG_SPACE(sizeof(int))]; 1317 } cmsgbuf; 1318 struct cmsghdr *cmsg; 1319 struct iovec iov; 1320 char c = '\0'; 1321 ssize_t r; 1322 struct pollfd pfd; 1323 1324 /* Avoid obvious stupidity */ 1325 if (isatty(STDOUT_FILENO)) 1326 errx(1, "Cannot pass file descriptor to tty"); 1327 1328 bzero(&mh, sizeof(mh)); 1329 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1330 bzero(&iov, sizeof(iov)); 1331 1332 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1333 mh.msg_controllen = sizeof(cmsgbuf.buf); 1334 cmsg = CMSG_FIRSTHDR(&mh); 1335 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1336 cmsg->cmsg_level = SOL_SOCKET; 1337 cmsg->cmsg_type = SCM_RIGHTS; 1338 *(int *)CMSG_DATA(cmsg) = nfd; 1339 1340 iov.iov_base = &c; 1341 iov.iov_len = 1; 1342 mh.msg_iov = &iov; 1343 mh.msg_iovlen = 1; 1344 1345 bzero(&pfd, sizeof(pfd)); 1346 pfd.fd = STDOUT_FILENO; 1347 pfd.events = POLLOUT; 1348 for (;;) { 1349 r = sendmsg(STDOUT_FILENO, &mh, 0); 1350 if (r == -1) { 1351 if (errno == EAGAIN || errno == EINTR) { 1352 if (poll(&pfd, 1, -1) == -1) 1353 err(1, "poll"); 1354 continue; 1355 } 1356 err(1, "sendmsg"); 1357 } else if (r != 1) 1358 errx(1, "sendmsg: unexpected return value %zd", r); 1359 else 1360 break; 1361 } 1362 exit(0); 1363 } 1364 1365 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1366 void 1367 atelnet(int nfd, unsigned char *buf, unsigned int size) 1368 { 1369 unsigned char *p, *end; 1370 unsigned char obuf[4]; 1371 1372 if (size < 3) 1373 return; 1374 end = buf + size - 2; 1375 1376 for (p = buf; p < end; p++) { 1377 if (*p != IAC) 1378 continue; 1379 1380 obuf[0] = IAC; 1381 p++; 1382 if ((*p == WILL) || (*p == WONT)) 1383 obuf[1] = DONT; 1384 else if ((*p == DO) || (*p == DONT)) 1385 obuf[1] = WONT; 1386 else 1387 continue; 1388 1389 p++; 1390 obuf[2] = *p; 1391 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1392 warn("Write Error!"); 1393 } 1394 } 1395 1396 1397 int 1398 strtoport(char *portstr, int udp) 1399 { 1400 struct servent *entry; 1401 const char *errstr; 1402 char *proto; 1403 int port = -1; 1404 1405 proto = udp ? "udp" : "tcp"; 1406 1407 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1408 if (errstr == NULL) 1409 return port; 1410 if (errno != EINVAL) 1411 errx(1, "port number %s: %s", errstr, portstr); 1412 if ((entry = getservbyname(portstr, proto)) == NULL) 1413 errx(1, "service \"%s\" unknown", portstr); 1414 return ntohs(entry->s_port); 1415 } 1416 1417 /* 1418 * build_ports() 1419 * Build an array of ports in portlist[], listing each port 1420 * that we should try to connect to. 1421 */ 1422 void 1423 build_ports(char *p) 1424 { 1425 char *n; 1426 int hi, lo, cp; 1427 int x = 0; 1428 1429 if ((n = strchr(p, '-')) != NULL) { 1430 *n = '\0'; 1431 n++; 1432 1433 /* Make sure the ports are in order: lowest->highest. */ 1434 hi = strtoport(n, uflag); 1435 lo = strtoport(p, uflag); 1436 if (lo > hi) { 1437 cp = hi; 1438 hi = lo; 1439 lo = cp; 1440 } 1441 1442 /* 1443 * Initialize portlist with a random permutation. Based on 1444 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1445 */ 1446 if (rflag) { 1447 for (x = 0; x <= hi - lo; x++) { 1448 cp = arc4random_uniform(x + 1); 1449 portlist[x] = portlist[cp]; 1450 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1451 err(1, "asprintf"); 1452 } 1453 } else { /* Load ports sequentially. */ 1454 for (cp = lo; cp <= hi; cp++) { 1455 if (asprintf(&portlist[x], "%d", cp) < 0) 1456 err(1, "asprintf"); 1457 x++; 1458 } 1459 } 1460 } else { 1461 char *tmp; 1462 1463 hi = strtoport(p, uflag); 1464 if (asprintf(&tmp, "%d", hi) != -1) 1465 portlist[0] = tmp; 1466 else 1467 err(1, NULL); 1468 } 1469 } 1470 1471 /* 1472 * udptest() 1473 * Do a few writes to see if the UDP port is there. 1474 * Fails once PF state table is full. 1475 */ 1476 int 1477 udptest(int s) 1478 { 1479 int i, ret; 1480 1481 for (i = 0; i <= 3; i++) { 1482 if (write(s, "X", 1) == 1) 1483 ret = 1; 1484 else 1485 ret = -1; 1486 } 1487 return ret; 1488 } 1489 1490 void 1491 set_common_sockopts(int s, int af) 1492 { 1493 int x = 1; 1494 1495 if (Sflag) { 1496 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1497 &x, sizeof(x)) == -1) 1498 err(1, NULL); 1499 } 1500 if (Dflag) { 1501 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1502 &x, sizeof(x)) == -1) 1503 err(1, NULL); 1504 } 1505 if (Tflag != -1) { 1506 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1507 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1508 err(1, "set IP ToS"); 1509 1510 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1511 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1512 err(1, "set IPv6 traffic class"); 1513 } 1514 if (Iflag) { 1515 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1516 &Iflag, sizeof(Iflag)) == -1) 1517 err(1, "set TCP receive buffer size"); 1518 } 1519 if (Oflag) { 1520 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1521 &Oflag, sizeof(Oflag)) == -1) 1522 err(1, "set TCP send buffer size"); 1523 } 1524 1525 if (ttl != -1) { 1526 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1527 IP_TTL, &ttl, sizeof(ttl))) 1528 err(1, "set IP TTL"); 1529 1530 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1531 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1532 err(1, "set IPv6 unicast hops"); 1533 } 1534 1535 if (minttl != -1) { 1536 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1537 IP_MINTTL, &minttl, sizeof(minttl))) 1538 err(1, "set IP min TTL"); 1539 1540 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1541 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1542 err(1, "set IPv6 min hop count"); 1543 } 1544 } 1545 1546 int 1547 process_tos_opt(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 int 1595 process_tls_opt(char *s, int *flags) 1596 { 1597 size_t len; 1598 char *v; 1599 1600 const struct tlskeywords { 1601 const char *keyword; 1602 int flag; 1603 char **value; 1604 } *t, tlskeywords[] = { 1605 { "ciphers", -1, &tls_ciphers }, 1606 { "clientcert", TLS_CCERT, NULL }, 1607 { "muststaple", TLS_MUSTSTAPLE, NULL }, 1608 { "noverify", TLS_NOVERIFY, NULL }, 1609 { "noname", TLS_NONAME, NULL }, 1610 { "protocols", -1, &tls_protocols }, 1611 { NULL, -1, NULL }, 1612 }; 1613 1614 len = strlen(s); 1615 if ((v = strchr(s, '=')) != NULL) { 1616 len = v - s; 1617 v++; 1618 } 1619 1620 for (t = tlskeywords; t->keyword != NULL; t++) { 1621 if (strlen(t->keyword) == len && 1622 strncmp(s, t->keyword, len) == 0) { 1623 if (t->value != NULL) { 1624 if (v == NULL) 1625 errx(1, "invalid tls value `%s'", s); 1626 *t->value = v; 1627 } else { 1628 *flags |= t->flag; 1629 } 1630 return 1; 1631 } 1632 } 1633 return 0; 1634 } 1635 1636 void 1637 save_peer_cert(struct tls *tls_ctx, FILE *fp) 1638 { 1639 const char *pem; 1640 size_t plen; 1641 1642 if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL) 1643 errx(1, "Can't get peer certificate"); 1644 if (fprintf(fp, "%.*s", (int)plen, pem) < 0) 1645 err(1, "unable to save peer cert"); 1646 if (fflush(fp) != 0) 1647 err(1, "unable to flush peer cert"); 1648 } 1649 1650 void 1651 report_tls(struct tls * tls_ctx, char * host) 1652 { 1653 time_t t; 1654 const char *ocsp_url; 1655 1656 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1657 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1658 fprintf(stderr, "Peer name: %s\n", 1659 tls_expectname ? tls_expectname : host); 1660 if (tls_peer_cert_subject(tls_ctx)) 1661 fprintf(stderr, "Subject: %s\n", 1662 tls_peer_cert_subject(tls_ctx)); 1663 if (tls_peer_cert_issuer(tls_ctx)) 1664 fprintf(stderr, "Issuer: %s\n", 1665 tls_peer_cert_issuer(tls_ctx)); 1666 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1667 fprintf(stderr, "Valid From: %s", ctime(&t)); 1668 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1669 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1670 if (tls_peer_cert_hash(tls_ctx)) 1671 fprintf(stderr, "Cert Hash: %s\n", 1672 tls_peer_cert_hash(tls_ctx)); 1673 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1674 if (ocsp_url != NULL) 1675 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1676 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1677 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1678 fprintf(stderr, "OCSP Stapling: %s\n", 1679 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1680 tls_peer_ocsp_result(tls_ctx)); 1681 fprintf(stderr, 1682 " response_status=%d cert_status=%d crl_reason=%d\n", 1683 tls_peer_ocsp_response_status(tls_ctx), 1684 tls_peer_ocsp_cert_status(tls_ctx), 1685 tls_peer_ocsp_crl_reason(tls_ctx)); 1686 t = tls_peer_ocsp_this_update(tls_ctx); 1687 fprintf(stderr, " this update: %s", 1688 t != -1 ? ctime(&t) : "\n"); 1689 t = tls_peer_ocsp_next_update(tls_ctx); 1690 fprintf(stderr, " next update: %s", 1691 t != -1 ? ctime(&t) : "\n"); 1692 t = tls_peer_ocsp_revocation_time(tls_ctx); 1693 fprintf(stderr, " revocation: %s", 1694 t != -1 ? ctime(&t) : "\n"); 1695 break; 1696 case -1: 1697 break; 1698 default: 1699 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1700 tls_peer_ocsp_response_status(tls_ctx), 1701 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1702 tls_peer_ocsp_result(tls_ctx)); 1703 break; 1704 1705 } 1706 } 1707 1708 void 1709 report_sock(const char *msg, const struct sockaddr *sa, socklen_t salen, 1710 char *path) 1711 { 1712 char host[NI_MAXHOST], port[NI_MAXSERV]; 1713 int herr; 1714 int flags = NI_NUMERICSERV; 1715 1716 if (path != NULL) { 1717 fprintf(stderr, "%s on %s\n", msg, path); 1718 return; 1719 } 1720 1721 if (nflag) 1722 flags |= NI_NUMERICHOST; 1723 1724 if ((herr = getnameinfo(sa, salen, host, sizeof(host), 1725 port, sizeof(port), flags)) != 0) { 1726 if (herr == EAI_SYSTEM) 1727 err(1, "getnameinfo"); 1728 else 1729 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1730 } 1731 1732 fprintf(stderr, "%s on %s %s\n", msg, host, port); 1733 } 1734 1735 void 1736 help(void) 1737 { 1738 usage(0); 1739 fprintf(stderr, "\tCommand Summary:\n\ 1740 \t-4 Use IPv4\n\ 1741 \t-6 Use IPv6\n\ 1742 \t-C certfile Public key file\n\ 1743 \t-c Use TLS\n\ 1744 \t-D Enable the debug socket option\n\ 1745 \t-d Detach from stdin\n\ 1746 \t-e name\t Required name in peer certificate\n\ 1747 \t-F Pass socket fd\n\ 1748 \t-H hash\t Hash string of peer certificate\n\ 1749 \t-h This help text\n\ 1750 \t-I length TCP receive buffer length\n\ 1751 \t-i interval Delay interval for lines sent, ports scanned\n\ 1752 \t-K keyfile Private key file\n\ 1753 \t-k Keep inbound sockets open for multiple connects\n\ 1754 \t-l Listen mode, for inbound connects\n\ 1755 \t-M ttl Outgoing TTL / Hop Limit\n\ 1756 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1757 \t-N Shutdown the network socket after EOF on stdin\n\ 1758 \t-n Suppress name/port resolutions\n\ 1759 \t-O length TCP send buffer length\n\ 1760 \t-o staplefile Staple file\n\ 1761 \t-P proxyuser\tUsername for proxy authentication\n\ 1762 \t-p port\t Specify local port for remote connects\n\ 1763 \t-R CAfile CA bundle\n\ 1764 \t-r Randomize remote ports\n\ 1765 \t-S Enable the TCP MD5 signature option\n\ 1766 \t-s source Local source address\n\ 1767 \t-T keyword TOS value or TLS options\n\ 1768 \t-t Answer TELNET negotiation\n\ 1769 \t-U Use UNIX domain socket\n\ 1770 \t-u UDP mode\n\ 1771 \t-V rtable Specify alternate routing table\n\ 1772 \t-v Verbose\n\ 1773 \t-W recvlimit Terminate after receiving a number of packets\n\ 1774 \t-w timeout Timeout for connects and final net reads\n\ 1775 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1776 \t-x addr[:port]\tSpecify proxy address and port\n\ 1777 \t-Z Peer certificate file\n\ 1778 \t-z Zero-I/O mode [used for scanning]\n\ 1779 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1780 exit(1); 1781 } 1782 1783 void 1784 usage(int ret) 1785 { 1786 fprintf(stderr, 1787 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1788 "[-H hash] [-I length]\n" 1789 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1790 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1791 "[-R CAfile]\n" 1792 "\t [-s source] [-T keyword] [-V rtable] [-W recvlimit] " 1793 "[-w timeout]\n" 1794 "\t [-X proxy_protocol] [-x proxy_address[:port]] " 1795 "[-Z peercertfile]\n" 1796 "\t [destination] [port]\n"); 1797 if (ret) 1798 exit(1); 1799 } 1800