1 /* $OpenBSD: netcat.c,v 1.229 2024/11/02 17:19:27 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 #define PORT_MAX 65535 63 #define UNIX_DG_TMP_SOCKET_SIZE 19 64 65 #define POLL_STDIN 0 66 #define POLL_NETOUT 1 67 #define POLL_NETIN 2 68 #define POLL_STDOUT 3 69 #define BUFSIZE 16384 70 71 #define TLS_NOVERIFY (1 << 1) 72 #define TLS_NONAME (1 << 2) 73 #define TLS_CCERT (1 << 3) 74 #define TLS_MUSTSTAPLE (1 << 4) 75 76 /* Command Line Options */ 77 int dflag; /* detached, no stdin */ 78 int Fflag; /* fdpass sock to stdout */ 79 unsigned int iflag; /* Interval Flag */ 80 int kflag; /* More than one connect */ 81 int lflag; /* Bind to local port */ 82 int Nflag; /* shutdown() network socket */ 83 int nflag; /* Don't do name look up */ 84 char *Pflag; /* Proxy username */ 85 char *pflag; /* Localport flag */ 86 int rflag; /* Random ports flag */ 87 char *sflag; /* Source Address */ 88 int tflag; /* Telnet Emulation */ 89 int uflag; /* UDP - Default to TCP */ 90 int vflag; /* Verbosity */ 91 int xflag; /* Socks proxy */ 92 int zflag; /* Port Scan Flag */ 93 int Dflag; /* sodebug */ 94 int Iflag; /* TCP receive buffer size */ 95 int Oflag; /* TCP send buffer size */ 96 int Sflag; /* TCP MD5 signature option */ 97 int Tflag = -1; /* IP Type of Service */ 98 int rtableid = -1; 99 100 int usetls; /* use TLS */ 101 const char *Cflag; /* Public cert file */ 102 const char *Kflag; /* Private key file */ 103 const char *oflag; /* OCSP stapling file */ 104 const char *Rflag; /* Root CA file */ 105 int tls_cachanged; /* Using non-default CA file */ 106 int TLSopt; /* TLS options */ 107 char *tls_expectname; /* required name in peer cert */ 108 char *tls_expecthash; /* required hash of peer cert */ 109 char *tls_ciphers; /* TLS ciphers */ 110 char *tls_protocols; /* TLS protocols */ 111 FILE *Zflag; /* file to save peer cert */ 112 113 int recvcount, recvlimit; 114 int timeout = -1; 115 int family = AF_UNSPEC; 116 char *portlist[PORT_MAX+1]; 117 char *unix_dg_tmp_socket; 118 int ttl = -1; 119 int minttl = -1; 120 121 void atelnet(int, unsigned char *, unsigned int); 122 int strtoport(char *portstr, int udp); 123 void build_ports(char *); 124 void help(void) __attribute__((noreturn)); 125 int local_listen(const char *, const char *, struct addrinfo); 126 void readwrite(int, struct tls *); 127 void fdpass(int nfd) __attribute__((noreturn)); 128 int remote_connect(const char *, const char *, struct addrinfo, char *); 129 int timeout_tls(int, struct tls *, int (*)(struct tls *)); 130 int timeout_connect(int, const struct sockaddr *, socklen_t); 131 int socks_connect(const char *, const char *, struct addrinfo, 132 const char *, const char *, struct addrinfo, int, const char *); 133 int udptest(int); 134 void connection_info(const char *, const char *, const char *, const char *); 135 int unix_bind(char *, int); 136 int unix_connect(char *); 137 int unix_listen(char *); 138 void set_common_sockopts(int, int); 139 int process_tos_opt(char *, int *); 140 int process_tls_opt(char *, int *); 141 void save_peer_cert(struct tls *_tls_ctx, FILE *_fp); 142 void report_sock(const char *, const struct sockaddr *, socklen_t, char *); 143 void report_tls(struct tls *tls_ctx, char * host); 144 void usage(int); 145 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 146 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 147 void tls_setup_client(struct tls *, int, char *); 148 struct tls *tls_setup_server(struct tls *, int, char *); 149 150 int 151 main(int argc, char *argv[]) 152 { 153 int ch, s = -1, ret, socksv; 154 char *host, *uport; 155 char ipaddr[NI_MAXHOST]; 156 struct addrinfo hints; 157 socklen_t len; 158 struct sockaddr_storage cliaddr; 159 char *proxy = NULL, *proxyport = NULL; 160 const char *errstr; 161 struct addrinfo proxyhints; 162 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 163 struct tls_config *tls_cfg = NULL; 164 struct tls *tls_ctx = NULL; 165 uint32_t protocols; 166 167 ret = 1; 168 socksv = 5; 169 host = NULL; 170 uport = NULL; 171 Rflag = tls_default_ca_cert_file(); 172 173 signal(SIGPIPE, SIG_IGN); 174 175 while ((ch = getopt(argc, argv, 176 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z")) 177 != -1) { 178 switch (ch) { 179 case '4': 180 family = AF_INET; 181 break; 182 case '6': 183 family = AF_INET6; 184 break; 185 case 'U': 186 family = AF_UNIX; 187 break; 188 case 'X': 189 if (strcasecmp(optarg, "connect") == 0) 190 socksv = -1; /* HTTP proxy CONNECT */ 191 else if (strcmp(optarg, "4") == 0) 192 socksv = 4; /* SOCKS v.4 */ 193 else if (strcmp(optarg, "5") == 0) 194 socksv = 5; /* SOCKS v.5 */ 195 else 196 errx(1, "unsupported proxy protocol"); 197 break; 198 case 'C': 199 Cflag = optarg; 200 break; 201 case 'c': 202 usetls = 1; 203 break; 204 case 'd': 205 dflag = 1; 206 break; 207 case 'e': 208 tls_expectname = optarg; 209 break; 210 case 'F': 211 Fflag = 1; 212 break; 213 case 'H': 214 tls_expecthash = optarg; 215 break; 216 case 'h': 217 help(); 218 break; 219 case 'i': 220 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 221 if (errstr) 222 errx(1, "interval %s: %s", errstr, optarg); 223 break; 224 case 'K': 225 Kflag = optarg; 226 break; 227 case 'k': 228 kflag = 1; 229 break; 230 case 'l': 231 lflag = 1; 232 break; 233 case 'M': 234 ttl = strtonum(optarg, 0, 255, &errstr); 235 if (errstr) 236 errx(1, "ttl is %s", errstr); 237 break; 238 case 'm': 239 minttl = strtonum(optarg, 0, 255, &errstr); 240 if (errstr) 241 errx(1, "minttl is %s", errstr); 242 break; 243 case 'N': 244 Nflag = 1; 245 break; 246 case 'n': 247 nflag = 1; 248 break; 249 case 'P': 250 Pflag = optarg; 251 break; 252 case 'p': 253 pflag = optarg; 254 break; 255 case 'R': 256 tls_cachanged = 1; 257 Rflag = optarg; 258 break; 259 case 'r': 260 rflag = 1; 261 break; 262 case 's': 263 sflag = optarg; 264 break; 265 case 't': 266 tflag = 1; 267 break; 268 case 'u': 269 uflag = 1; 270 break; 271 case 'V': 272 rtableid = (int)strtonum(optarg, 0, 273 RT_TABLEID_MAX, &errstr); 274 if (errstr) 275 errx(1, "rtable %s: %s", errstr, optarg); 276 break; 277 case 'v': 278 vflag = 1; 279 break; 280 case 'W': 281 recvlimit = strtonum(optarg, 1, INT_MAX, &errstr); 282 if (errstr) 283 errx(1, "receive limit %s: %s", errstr, optarg); 284 break; 285 case 'w': 286 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 287 if (errstr) 288 errx(1, "timeout %s: %s", errstr, optarg); 289 timeout *= 1000; 290 break; 291 case 'x': 292 xflag = 1; 293 if ((proxy = strdup(optarg)) == NULL) 294 err(1, NULL); 295 break; 296 case 'Z': 297 if (strcmp(optarg, "-") == 0) 298 Zflag = stderr; 299 else if ((Zflag = fopen(optarg, "w")) == NULL) 300 err(1, "can't open %s", optarg); 301 break; 302 case 'z': 303 zflag = 1; 304 break; 305 case 'D': 306 Dflag = 1; 307 break; 308 case 'I': 309 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 310 if (errstr != NULL) 311 errx(1, "TCP receive window %s: %s", 312 errstr, optarg); 313 break; 314 case 'O': 315 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 316 if (errstr != NULL) 317 errx(1, "TCP send window %s: %s", 318 errstr, optarg); 319 break; 320 case 'o': 321 oflag = optarg; 322 break; 323 case 'S': 324 Sflag = 1; 325 break; 326 case 'T': 327 errstr = NULL; 328 errno = 0; 329 if (process_tls_opt(optarg, &TLSopt)) 330 break; 331 if (process_tos_opt(optarg, &Tflag)) 332 break; 333 if (strlen(optarg) > 1 && optarg[0] == '0' && 334 optarg[1] == 'x') 335 Tflag = (int)strtol(optarg, NULL, 16); 336 else 337 Tflag = (int)strtonum(optarg, 0, 255, 338 &errstr); 339 if (Tflag < 0 || Tflag > 255 || errstr || errno) 340 errx(1, "illegal tos/tls value %s", optarg); 341 break; 342 default: 343 usage(1); 344 } 345 } 346 argc -= optind; 347 argv += optind; 348 349 if (rtableid >= 0) 350 if (setrtable(rtableid) == -1) 351 err(1, "setrtable"); 352 353 /* Cruft to make sure options are clean, and used properly. */ 354 if (argc == 1 && family == AF_UNIX) { 355 host = argv[0]; 356 } else if (argc == 1 && lflag) { 357 uport = argv[0]; 358 } else if (argc == 2) { 359 host = argv[0]; 360 uport = argv[1]; 361 } else 362 usage(1); 363 364 if (usetls) { 365 if (Cflag && unveil(Cflag, "r") == -1) 366 err(1, "unveil %s", Cflag); 367 if (unveil(Rflag, "r") == -1) 368 err(1, "unveil %s", Rflag); 369 if (Kflag && unveil(Kflag, "r") == -1) 370 err(1, "unveil %s", Kflag); 371 if (oflag && unveil(oflag, "r") == -1) 372 err(1, "unveil %s", oflag); 373 } else if (family == AF_UNIX && uflag && lflag && !kflag) { 374 /* 375 * After recvfrom(2) from client, the server connects 376 * to the client socket. As the client path is determined 377 * during runtime, we cannot unveil(2). 378 */ 379 } else { 380 if (family == AF_UNIX) { 381 if (unveil(host, "rwc") == -1) 382 err(1, "unveil %s", host); 383 if (uflag && !kflag) { 384 if (sflag) { 385 if (unveil(sflag, "rwc") == -1) 386 err(1, "unveil %s", sflag); 387 } else { 388 if (unveil("/tmp", "rwc") == -1) 389 err(1, "unveil /tmp"); 390 } 391 } 392 } else { 393 /* no filesystem visibility */ 394 if (unveil("/", "") == -1) 395 err(1, "unveil /"); 396 } 397 } 398 399 if (family == AF_UNIX) { 400 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 401 err(1, "pledge"); 402 } else if (Fflag && Pflag) { 403 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 404 err(1, "pledge"); 405 } else if (Fflag) { 406 if (pledge("stdio inet dns sendfd", NULL) == -1) 407 err(1, "pledge"); 408 } else if (Pflag && usetls) { 409 if (pledge("stdio rpath inet dns tty", NULL) == -1) 410 err(1, "pledge"); 411 } else if (Pflag) { 412 if (pledge("stdio inet dns tty", NULL) == -1) 413 err(1, "pledge"); 414 } else if (usetls) { 415 if (pledge("stdio rpath inet dns", NULL) == -1) 416 err(1, "pledge"); 417 } else if (pledge("stdio inet dns", NULL) == -1) 418 err(1, "pledge"); 419 420 if (lflag && sflag) 421 errx(1, "cannot use -s and -l"); 422 if (lflag && pflag) 423 errx(1, "cannot use -p and -l"); 424 if (lflag && zflag) 425 errx(1, "cannot use -z and -l"); 426 if (!lflag && kflag) 427 errx(1, "must use -l with -k"); 428 if (uflag && usetls) 429 errx(1, "cannot use -c and -u"); 430 if ((family == AF_UNIX) && usetls) 431 errx(1, "cannot use -c and -U"); 432 if ((family == AF_UNIX) && Fflag) 433 errx(1, "cannot use -F and -U"); 434 if (Fflag && usetls) 435 errx(1, "cannot use -c and -F"); 436 if (TLSopt && !usetls) 437 errx(1, "you must specify -c to use TLS options"); 438 if (Cflag && !usetls) 439 errx(1, "you must specify -c to use -C"); 440 if (Kflag && !usetls) 441 errx(1, "you must specify -c to use -K"); 442 if (Zflag && !usetls) 443 errx(1, "you must specify -c to use -Z"); 444 if (oflag && !Cflag) 445 errx(1, "you must specify -C to use -o"); 446 if (tls_cachanged && !usetls) 447 errx(1, "you must specify -c to use -R"); 448 if (tls_expecthash && !usetls) 449 errx(1, "you must specify -c to use -H"); 450 if (tls_expectname && !usetls) 451 errx(1, "you must specify -c to use -e"); 452 453 /* Get name of temporary socket for unix datagram client */ 454 if ((family == AF_UNIX) && uflag && !lflag) { 455 if (sflag) { 456 unix_dg_tmp_socket = sflag; 457 } else { 458 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 459 UNIX_DG_TMP_SOCKET_SIZE); 460 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 461 err(1, "mktemp"); 462 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 463 } 464 } 465 466 /* Initialize addrinfo structure. */ 467 if (family != AF_UNIX) { 468 memset(&hints, 0, sizeof(struct addrinfo)); 469 hints.ai_family = family; 470 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 471 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 472 if (nflag) 473 hints.ai_flags |= AI_NUMERICHOST; 474 } 475 476 if (xflag) { 477 if (uflag) 478 errx(1, "no proxy support for UDP mode"); 479 480 if (lflag) 481 errx(1, "no proxy support for listen"); 482 483 if (family == AF_UNIX) 484 errx(1, "no proxy support for unix sockets"); 485 486 if (sflag) 487 errx(1, "no proxy support for local source address"); 488 489 if (*proxy == '[') { 490 ++proxy; 491 proxyport = strchr(proxy, ']'); 492 if (proxyport == NULL) 493 errx(1, "missing closing bracket in proxy"); 494 *proxyport++ = '\0'; 495 if (*proxyport == '\0') 496 /* Use default proxy port. */ 497 proxyport = NULL; 498 else { 499 if (*proxyport == ':') 500 ++proxyport; 501 else 502 errx(1, "garbage proxy port delimiter"); 503 } 504 } else { 505 proxyport = strrchr(proxy, ':'); 506 if (proxyport != NULL) 507 *proxyport++ = '\0'; 508 } 509 510 memset(&proxyhints, 0, sizeof(struct addrinfo)); 511 proxyhints.ai_family = family; 512 proxyhints.ai_socktype = SOCK_STREAM; 513 proxyhints.ai_protocol = IPPROTO_TCP; 514 if (nflag) 515 proxyhints.ai_flags |= AI_NUMERICHOST; 516 } 517 518 if (usetls) { 519 if ((tls_cfg = tls_config_new()) == NULL) 520 errx(1, "unable to allocate TLS config"); 521 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 522 errx(1, "%s", tls_config_error(tls_cfg)); 523 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 524 errx(1, "%s", tls_config_error(tls_cfg)); 525 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 526 errx(1, "%s", tls_config_error(tls_cfg)); 527 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 528 errx(1, "%s", tls_config_error(tls_cfg)); 529 if (tls_config_parse_protocols(&protocols, tls_protocols) == -1) 530 errx(1, "invalid TLS protocols `%s'", tls_protocols); 531 if (tls_config_set_protocols(tls_cfg, protocols) == -1) 532 errx(1, "%s", tls_config_error(tls_cfg)); 533 if (tls_config_set_ciphers(tls_cfg, tls_ciphers) == -1) 534 errx(1, "%s", tls_config_error(tls_cfg)); 535 if (!lflag && (TLSopt & TLS_CCERT)) 536 errx(1, "clientcert is only valid with -l"); 537 if (TLSopt & TLS_NONAME) 538 tls_config_insecure_noverifyname(tls_cfg); 539 if (TLSopt & TLS_NOVERIFY) { 540 if (tls_expecthash != NULL) 541 errx(1, "-H and -T noverify may not be used " 542 "together"); 543 tls_config_insecure_noverifycert(tls_cfg); 544 } 545 if (TLSopt & TLS_MUSTSTAPLE) 546 tls_config_ocsp_require_stapling(tls_cfg); 547 548 if (Pflag) { 549 if (pledge("stdio inet dns tty", NULL) == -1) 550 err(1, "pledge"); 551 } else if (pledge("stdio inet dns", NULL) == -1) 552 err(1, "pledge"); 553 } 554 if (lflag) { 555 ret = 0; 556 557 if (family == AF_UNIX) { 558 if (uflag) 559 s = unix_bind(host, 0); 560 else 561 s = unix_listen(host); 562 } 563 564 if (usetls) { 565 tls_config_verify_client_optional(tls_cfg); 566 if ((tls_ctx = tls_server()) == NULL) 567 errx(1, "tls server creation failed"); 568 if (tls_configure(tls_ctx, tls_cfg) == -1) 569 errx(1, "tls configuration failed (%s)", 570 tls_error(tls_ctx)); 571 } 572 /* Allow only one connection at a time, but stay alive. */ 573 for (;;) { 574 if (family != AF_UNIX) { 575 if (s != -1) 576 close(s); 577 s = local_listen(host, uport, hints); 578 } 579 if (s == -1) 580 err(1, NULL); 581 if (uflag && kflag) { 582 if (family == AF_UNIX) { 583 if (pledge("stdio unix", NULL) == -1) 584 err(1, "pledge"); 585 } 586 /* 587 * For UDP and -k, don't connect the socket, 588 * let it receive datagrams from multiple 589 * socket pairs. 590 */ 591 readwrite(s, NULL); 592 } else if (uflag && !kflag) { 593 /* 594 * For UDP and not -k, we will use recvfrom() 595 * initially to wait for a caller, then use 596 * the regular functions to talk to the caller. 597 */ 598 int rv; 599 char buf[2048]; 600 struct sockaddr_storage z; 601 602 len = sizeof(z); 603 rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK, 604 (struct sockaddr *)&z, &len); 605 if (rv == -1) 606 err(1, "recvfrom"); 607 608 rv = connect(s, (struct sockaddr *)&z, len); 609 if (rv == -1) 610 err(1, "connect"); 611 612 if (family == AF_UNIX) { 613 if (pledge("stdio unix", NULL) == -1) 614 err(1, "pledge"); 615 } 616 if (vflag) 617 report_sock("Connection received", 618 (struct sockaddr *)&z, len, 619 family == AF_UNIX ? host : NULL); 620 621 readwrite(s, NULL); 622 } else { 623 struct tls *tls_cctx = NULL; 624 int connfd; 625 626 len = sizeof(cliaddr); 627 connfd = accept4(s, (struct sockaddr *)&cliaddr, 628 &len, SOCK_NONBLOCK); 629 if (connfd == -1) { 630 /* For now, all errnos are fatal */ 631 err(1, "accept"); 632 } 633 if (vflag) 634 report_sock("Connection received", 635 (struct sockaddr *)&cliaddr, len, 636 family == AF_UNIX ? host : NULL); 637 if ((usetls) && 638 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 639 readwrite(connfd, tls_cctx); 640 if (!usetls) 641 readwrite(connfd, NULL); 642 if (tls_cctx) 643 timeout_tls(s, tls_cctx, tls_close); 644 close(connfd); 645 tls_free(tls_cctx); 646 } 647 648 if (!kflag) 649 break; 650 } 651 } else if (family == AF_UNIX) { 652 ret = 0; 653 654 if ((s = unix_connect(host)) > 0) { 655 if (!zflag) 656 readwrite(s, NULL); 657 close(s); 658 } else { 659 warn("%s", host); 660 ret = 1; 661 } 662 663 if (uflag) 664 unlink(unix_dg_tmp_socket); 665 return ret; 666 } else { 667 int i = 0; 668 669 /* Construct the portlist[] array. */ 670 build_ports(uport); 671 672 /* Cycle through portlist, connecting to each port. */ 673 for (s = -1, i = 0; portlist[i] != NULL; i++) { 674 if (s != -1) 675 close(s); 676 tls_free(tls_ctx); 677 tls_ctx = NULL; 678 679 if (usetls) { 680 if ((tls_ctx = tls_client()) == NULL) 681 errx(1, "tls client creation failed"); 682 if (tls_configure(tls_ctx, tls_cfg) == -1) 683 errx(1, "tls configuration failed (%s)", 684 tls_error(tls_ctx)); 685 } 686 if (xflag) 687 s = socks_connect(host, portlist[i], hints, 688 proxy, proxyport, proxyhints, socksv, 689 Pflag); 690 else 691 s = remote_connect(host, portlist[i], hints, 692 ipaddr); 693 694 if (s == -1) 695 continue; 696 697 ret = 0; 698 if (vflag || zflag) { 699 int print_info = 1; 700 701 /* For UDP, make sure we are connected. */ 702 if (uflag) { 703 /* No info on failed or skipped test. */ 704 if ((print_info = udptest(s)) == -1) { 705 ret = 1; 706 continue; 707 } 708 } 709 if (print_info == 1) 710 connection_info(host, portlist[i], 711 uflag ? "udp" : "tcp", ipaddr); 712 } 713 if (Fflag) 714 fdpass(s); 715 else { 716 if (usetls) 717 tls_setup_client(tls_ctx, s, host); 718 if (!zflag) 719 readwrite(s, tls_ctx); 720 if (tls_ctx) 721 timeout_tls(s, tls_ctx, tls_close); 722 } 723 } 724 } 725 726 if (s != -1) 727 close(s); 728 tls_free(tls_ctx); 729 tls_config_free(tls_cfg); 730 731 return ret; 732 } 733 734 /* 735 * unix_bind() 736 * Returns a unix socket bound to the given path 737 */ 738 int 739 unix_bind(char *path, int flags) 740 { 741 struct sockaddr_un s_un; 742 int s, save_errno; 743 744 /* Create unix domain socket. */ 745 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 746 0)) == -1) 747 return -1; 748 749 memset(&s_un, 0, sizeof(struct sockaddr_un)); 750 s_un.sun_family = AF_UNIX; 751 752 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 753 sizeof(s_un.sun_path)) { 754 close(s); 755 errno = ENAMETOOLONG; 756 return -1; 757 } 758 759 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { 760 save_errno = errno; 761 close(s); 762 errno = save_errno; 763 return -1; 764 } 765 if (vflag) 766 report_sock("Bound", NULL, 0, path); 767 768 return s; 769 } 770 771 int 772 timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) 773 { 774 struct pollfd pfd; 775 int ret; 776 777 while ((ret = func(tls_ctx)) != 0) { 778 if (ret == TLS_WANT_POLLIN) 779 pfd.events = POLLIN; 780 else if (ret == TLS_WANT_POLLOUT) 781 pfd.events = POLLOUT; 782 else 783 break; 784 pfd.fd = s; 785 if ((ret = poll(&pfd, 1, timeout)) == 1) 786 continue; 787 else if (ret == 0) { 788 errno = ETIMEDOUT; 789 ret = -1; 790 break; 791 } else 792 err(1, "poll failed"); 793 } 794 795 return ret; 796 } 797 798 void 799 tls_setup_client(struct tls *tls_ctx, int s, char *host) 800 { 801 const char *errstr; 802 803 if (tls_connect_socket(tls_ctx, s, 804 tls_expectname ? tls_expectname : host) == -1) { 805 errx(1, "tls connection failed (%s)", 806 tls_error(tls_ctx)); 807 } 808 if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { 809 if ((errstr = tls_error(tls_ctx)) == NULL) 810 errstr = strerror(errno); 811 errx(1, "tls handshake failed (%s)", errstr); 812 } 813 if (vflag) 814 report_tls(tls_ctx, host); 815 if (tls_expecthash && (tls_peer_cert_hash(tls_ctx) == NULL || 816 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0)) 817 errx(1, "peer certificate is not %s", tls_expecthash); 818 if (Zflag) { 819 save_peer_cert(tls_ctx, Zflag); 820 if (Zflag != stderr && (fclose(Zflag) != 0)) 821 err(1, "fclose failed saving peer cert"); 822 } 823 } 824 825 struct tls * 826 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 827 { 828 struct tls *tls_cctx; 829 const char *errstr; 830 831 if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { 832 warnx("tls accept failed (%s)", tls_error(tls_ctx)); 833 } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { 834 if ((errstr = tls_error(tls_cctx)) == NULL) 835 errstr = strerror(errno); 836 warnx("tls handshake failed (%s)", errstr); 837 } else { 838 int gotcert = tls_peer_cert_provided(tls_cctx); 839 840 if (vflag && gotcert) 841 report_tls(tls_cctx, host); 842 if ((TLSopt & TLS_CCERT) && !gotcert) 843 warnx("No client certificate provided"); 844 else if (gotcert && tls_expecthash && 845 (tls_peer_cert_hash(tls_cctx) == NULL || 846 strcmp(tls_expecthash, tls_peer_cert_hash(tls_cctx)) != 0)) 847 warnx("peer certificate is not %s", tls_expecthash); 848 else if (gotcert && tls_expectname && 849 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 850 warnx("name (%s) not found in client cert", 851 tls_expectname); 852 else { 853 return tls_cctx; 854 } 855 } 856 return NULL; 857 } 858 859 /* 860 * unix_connect() 861 * Returns a socket connected to a local unix socket. Returns -1 on failure. 862 */ 863 int 864 unix_connect(char *path) 865 { 866 struct sockaddr_un s_un; 867 int s, save_errno; 868 869 if (uflag) { 870 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) == -1) 871 return -1; 872 } else { 873 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) == -1) 874 return -1; 875 } 876 877 memset(&s_un, 0, sizeof(struct sockaddr_un)); 878 s_un.sun_family = AF_UNIX; 879 880 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 881 sizeof(s_un.sun_path)) { 882 close(s); 883 errno = ENAMETOOLONG; 884 return -1; 885 } 886 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { 887 save_errno = errno; 888 close(s); 889 errno = save_errno; 890 return -1; 891 } 892 return s; 893 } 894 895 /* 896 * unix_listen() 897 * Create a unix domain socket, and listen on it. 898 */ 899 int 900 unix_listen(char *path) 901 { 902 int s; 903 904 if ((s = unix_bind(path, 0)) == -1) 905 return -1; 906 if (listen(s, 5) == -1) { 907 close(s); 908 return -1; 909 } 910 if (vflag) 911 report_sock("Listening", NULL, 0, path); 912 913 return s; 914 } 915 916 /* 917 * remote_connect() 918 * Returns a socket connected to a remote host. Properly binds to a local 919 * port or source address if needed. Returns -1 on failure. 920 */ 921 int 922 remote_connect(const char *host, const char *port, struct addrinfo hints, 923 char *ipaddr) 924 { 925 struct addrinfo *res, *res0; 926 int s = -1, error, herr, on = 1, save_errno; 927 928 if ((error = getaddrinfo(host, port, &hints, &res0))) 929 errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, 930 port, gai_strerror(error)); 931 932 for (res = res0; res; res = res->ai_next) { 933 if ((s = socket(res->ai_family, res->ai_socktype | 934 SOCK_NONBLOCK, res->ai_protocol)) == -1) 935 continue; 936 937 /* Bind to a local port or source address if specified. */ 938 if (sflag || pflag) { 939 struct addrinfo ahints, *ares; 940 941 /* try SO_BINDANY, but don't insist */ 942 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 943 memset(&ahints, 0, sizeof(struct addrinfo)); 944 ahints.ai_family = res->ai_family; 945 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 946 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 947 ahints.ai_flags = AI_PASSIVE; 948 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 949 errx(1, "getaddrinfo: %s", gai_strerror(error)); 950 951 if (bind(s, (struct sockaddr *)ares->ai_addr, 952 ares->ai_addrlen) == -1) 953 err(1, "bind failed"); 954 freeaddrinfo(ares); 955 } 956 957 set_common_sockopts(s, res->ai_family); 958 959 if (ipaddr != NULL) { 960 herr = getnameinfo(res->ai_addr, res->ai_addrlen, 961 ipaddr, NI_MAXHOST, NULL, 0, NI_NUMERICHOST); 962 switch (herr) { 963 case 0: 964 break; 965 case EAI_SYSTEM: 966 err(1, "getnameinfo"); 967 default: 968 errx(1, "getnameinfo: %s", gai_strerror(herr)); 969 } 970 } 971 972 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 973 break; 974 975 if (vflag) { 976 /* only print IP if there is something to report */ 977 if (nflag || ipaddr == NULL || 978 (strncmp(host, ipaddr, NI_MAXHOST) == 0)) 979 warn("connect to %s port %s (%s) failed", host, 980 port, uflag ? "udp" : "tcp"); 981 else 982 warn("connect to %s (%s) port %s (%s) failed", 983 host, ipaddr, port, uflag ? "udp" : "tcp"); 984 } 985 986 save_errno = errno; 987 close(s); 988 errno = save_errno; 989 s = -1; 990 } 991 992 freeaddrinfo(res0); 993 994 return s; 995 } 996 997 int 998 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 999 { 1000 struct pollfd pfd; 1001 socklen_t optlen; 1002 int optval; 1003 int ret; 1004 1005 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 1006 pfd.fd = s; 1007 pfd.events = POLLOUT; 1008 if ((ret = poll(&pfd, 1, timeout)) == 1) { 1009 optlen = sizeof(optval); 1010 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 1011 &optval, &optlen)) == 0) { 1012 errno = optval; 1013 ret = optval == 0 ? 0 : -1; 1014 } 1015 } else if (ret == 0) { 1016 errno = ETIMEDOUT; 1017 ret = -1; 1018 } else 1019 err(1, "poll failed"); 1020 } 1021 1022 return ret; 1023 } 1024 1025 /* 1026 * local_listen() 1027 * Returns a socket listening on a local port, binds to specified source 1028 * address. Returns -1 on failure. 1029 */ 1030 int 1031 local_listen(const char *host, const char *port, struct addrinfo hints) 1032 { 1033 struct addrinfo *res, *res0; 1034 int s = -1, ret, x = 1, save_errno; 1035 int error; 1036 1037 /* Allow nodename to be null. */ 1038 hints.ai_flags |= AI_PASSIVE; 1039 1040 /* 1041 * In the case of binding to a wildcard address 1042 * default to binding to an ipv4 address. 1043 */ 1044 if (host == NULL && hints.ai_family == AF_UNSPEC) 1045 hints.ai_family = AF_INET; 1046 1047 if ((error = getaddrinfo(host, port, &hints, &res0))) 1048 errx(1, "getaddrinfo: %s", gai_strerror(error)); 1049 1050 for (res = res0; res; res = res->ai_next) { 1051 if ((s = socket(res->ai_family, res->ai_socktype, 1052 res->ai_protocol)) == -1) 1053 continue; 1054 1055 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 1056 if (ret == -1) 1057 err(1, NULL); 1058 1059 set_common_sockopts(s, res->ai_family); 1060 1061 if (bind(s, (struct sockaddr *)res->ai_addr, 1062 res->ai_addrlen) == 0) 1063 break; 1064 1065 save_errno = errno; 1066 close(s); 1067 errno = save_errno; 1068 s = -1; 1069 } 1070 1071 if (!uflag && s != -1) { 1072 if (listen(s, 1) == -1) 1073 err(1, "listen"); 1074 } 1075 if (vflag && s != -1) { 1076 struct sockaddr_storage ss; 1077 socklen_t len; 1078 1079 len = sizeof(ss); 1080 if (getsockname(s, (struct sockaddr *)&ss, &len) == -1) 1081 err(1, "getsockname"); 1082 report_sock(uflag ? "Bound" : "Listening", 1083 (struct sockaddr *)&ss, len, NULL); 1084 } 1085 1086 freeaddrinfo(res0); 1087 1088 return s; 1089 } 1090 1091 /* 1092 * readwrite() 1093 * Loop that polls on the network file descriptor and stdin. 1094 */ 1095 void 1096 readwrite(int net_fd, struct tls *tls_ctx) 1097 { 1098 struct pollfd pfd[4]; 1099 int stdin_fd = STDIN_FILENO; 1100 int stdout_fd = STDOUT_FILENO; 1101 unsigned char netinbuf[BUFSIZE]; 1102 size_t netinbufpos = 0; 1103 unsigned char stdinbuf[BUFSIZE]; 1104 size_t stdinbufpos = 0; 1105 int n, num_fds; 1106 ssize_t ret; 1107 1108 /* don't read from stdin if requested */ 1109 if (dflag) 1110 stdin_fd = -1; 1111 1112 /* stdin */ 1113 pfd[POLL_STDIN].fd = stdin_fd; 1114 pfd[POLL_STDIN].events = POLLIN; 1115 1116 /* network out */ 1117 pfd[POLL_NETOUT].fd = net_fd; 1118 pfd[POLL_NETOUT].events = 0; 1119 1120 /* network in */ 1121 pfd[POLL_NETIN].fd = net_fd; 1122 pfd[POLL_NETIN].events = POLLIN; 1123 1124 /* stdout */ 1125 pfd[POLL_STDOUT].fd = stdout_fd; 1126 pfd[POLL_STDOUT].events = 0; 1127 1128 while (1) { 1129 /* both inputs are gone, buffers are empty, we are done */ 1130 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1131 stdinbufpos == 0 && netinbufpos == 0) 1132 return; 1133 /* both outputs are gone, we can't continue */ 1134 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) 1135 return; 1136 /* listen and net in gone, queues empty, done */ 1137 if (lflag && pfd[POLL_NETIN].fd == -1 && 1138 stdinbufpos == 0 && netinbufpos == 0) 1139 return; 1140 1141 /* help says -i is for "wait between lines sent". We read and 1142 * write arbitrary amounts of data, and we don't want to start 1143 * scanning for newlines, so this is as good as it gets */ 1144 if (iflag) 1145 sleep(iflag); 1146 1147 /* poll */ 1148 num_fds = poll(pfd, 4, timeout); 1149 1150 /* treat poll errors */ 1151 if (num_fds == -1) 1152 err(1, "polling error"); 1153 1154 /* timeout happened */ 1155 if (num_fds == 0) 1156 return; 1157 1158 /* treat socket error conditions */ 1159 for (n = 0; n < 4; n++) { 1160 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1161 pfd[n].fd = -1; 1162 } 1163 } 1164 /* reading is possible after HUP */ 1165 if (pfd[POLL_STDIN].events & POLLIN && 1166 pfd[POLL_STDIN].revents & POLLHUP && 1167 !(pfd[POLL_STDIN].revents & POLLIN)) 1168 pfd[POLL_STDIN].fd = -1; 1169 1170 if (pfd[POLL_NETIN].events & POLLIN && 1171 pfd[POLL_NETIN].revents & POLLHUP && 1172 !(pfd[POLL_NETIN].revents & POLLIN)) 1173 pfd[POLL_NETIN].fd = -1; 1174 1175 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1176 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1177 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1178 pfd[POLL_NETOUT].fd = -1; 1179 } 1180 /* if HUP, stop watching stdout */ 1181 if (pfd[POLL_STDOUT].revents & POLLHUP) 1182 pfd[POLL_STDOUT].fd = -1; 1183 /* if no net out, stop watching stdin */ 1184 if (pfd[POLL_NETOUT].fd == -1) 1185 pfd[POLL_STDIN].fd = -1; 1186 /* if no stdout, stop watching net in */ 1187 if (pfd[POLL_STDOUT].fd == -1) { 1188 if (pfd[POLL_NETIN].fd != -1) 1189 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1190 pfd[POLL_NETIN].fd = -1; 1191 } 1192 1193 /* try to read from stdin */ 1194 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1195 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1196 &stdinbufpos, NULL); 1197 if (ret == TLS_WANT_POLLIN) 1198 pfd[POLL_STDIN].events = POLLIN; 1199 else if (ret == TLS_WANT_POLLOUT) 1200 pfd[POLL_STDIN].events = POLLOUT; 1201 else if (ret == 0 || ret == -1) 1202 pfd[POLL_STDIN].fd = -1; 1203 /* read something - poll net out */ 1204 if (stdinbufpos > 0) 1205 pfd[POLL_NETOUT].events = POLLOUT; 1206 /* filled buffer - remove self from polling */ 1207 if (stdinbufpos == BUFSIZE) 1208 pfd[POLL_STDIN].events = 0; 1209 } 1210 /* try to write to network */ 1211 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1212 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1213 &stdinbufpos, tls_ctx); 1214 if (ret == TLS_WANT_POLLIN) 1215 pfd[POLL_NETOUT].events = POLLIN; 1216 else if (ret == TLS_WANT_POLLOUT) 1217 pfd[POLL_NETOUT].events = POLLOUT; 1218 else if (ret == -1) 1219 pfd[POLL_NETOUT].fd = -1; 1220 /* buffer empty - remove self from polling */ 1221 if (stdinbufpos == 0) 1222 pfd[POLL_NETOUT].events = 0; 1223 /* buffer no longer full - poll stdin again */ 1224 if (stdinbufpos < BUFSIZE) 1225 pfd[POLL_STDIN].events = POLLIN; 1226 } 1227 /* try to read from network */ 1228 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1229 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1230 &netinbufpos, tls_ctx); 1231 if (ret == TLS_WANT_POLLIN) 1232 pfd[POLL_NETIN].events = POLLIN; 1233 else if (ret == TLS_WANT_POLLOUT) 1234 pfd[POLL_NETIN].events = POLLOUT; 1235 else if (ret == -1) 1236 pfd[POLL_NETIN].fd = -1; 1237 /* eof on net in - remove from pfd */ 1238 if (ret == 0) { 1239 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1240 pfd[POLL_NETIN].fd = -1; 1241 } 1242 if (recvlimit > 0 && ++recvcount >= recvlimit) { 1243 if (pfd[POLL_NETIN].fd != -1) 1244 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1245 pfd[POLL_NETIN].fd = -1; 1246 pfd[POLL_STDIN].fd = -1; 1247 } 1248 /* read something - poll stdout */ 1249 if (netinbufpos > 0) 1250 pfd[POLL_STDOUT].events = POLLOUT; 1251 /* filled buffer - remove self from polling */ 1252 if (netinbufpos == BUFSIZE) 1253 pfd[POLL_NETIN].events = 0; 1254 /* handle telnet */ 1255 if (pfd[POLL_NETIN].fd != -1 && tflag) 1256 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1257 netinbufpos); 1258 } 1259 /* try to write to stdout */ 1260 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1261 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1262 &netinbufpos, NULL); 1263 if (ret == TLS_WANT_POLLIN) 1264 pfd[POLL_STDOUT].events = POLLIN; 1265 else if (ret == TLS_WANT_POLLOUT) 1266 pfd[POLL_STDOUT].events = POLLOUT; 1267 else if (ret == -1) 1268 pfd[POLL_STDOUT].fd = -1; 1269 /* buffer empty - remove self from polling */ 1270 if (netinbufpos == 0) 1271 pfd[POLL_STDOUT].events = 0; 1272 /* buffer no longer full - poll net in again */ 1273 if (netinbufpos < BUFSIZE) 1274 pfd[POLL_NETIN].events = POLLIN; 1275 } 1276 1277 /* stdin gone and queue empty? */ 1278 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1279 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1280 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1281 pfd[POLL_NETOUT].fd = -1; 1282 } 1283 /* net in gone and queue empty? */ 1284 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1285 pfd[POLL_STDOUT].fd = -1; 1286 } 1287 } 1288 } 1289 1290 ssize_t 1291 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1292 { 1293 ssize_t n; 1294 ssize_t adjust; 1295 1296 if (fd == -1) 1297 return -1; 1298 1299 if (tls) { 1300 n = tls_write(tls, buf, *bufpos); 1301 if (n == -1) 1302 errx(1, "tls write failed (%s)", tls_error(tls)); 1303 } else { 1304 n = write(fd, buf, *bufpos); 1305 /* don't treat EAGAIN, EINTR as error */ 1306 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1307 n = TLS_WANT_POLLOUT; 1308 } 1309 if (n <= 0) 1310 return n; 1311 /* adjust buffer */ 1312 adjust = *bufpos - n; 1313 if (adjust > 0) 1314 memmove(buf, buf + n, adjust); 1315 *bufpos -= n; 1316 return n; 1317 } 1318 1319 ssize_t 1320 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1321 { 1322 size_t num = BUFSIZE - *bufpos; 1323 ssize_t n; 1324 1325 if (fd == -1) 1326 return -1; 1327 1328 if (tls) { 1329 n = tls_read(tls, buf + *bufpos, num); 1330 if (n == -1) 1331 errx(1, "tls read failed (%s)", tls_error(tls)); 1332 } else { 1333 n = read(fd, buf + *bufpos, num); 1334 /* don't treat EAGAIN, EINTR as error */ 1335 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1336 n = TLS_WANT_POLLIN; 1337 } 1338 if (n <= 0) 1339 return n; 1340 *bufpos += n; 1341 return n; 1342 } 1343 1344 /* 1345 * fdpass() 1346 * Pass the connected file descriptor to stdout and exit. 1347 */ 1348 void 1349 fdpass(int nfd) 1350 { 1351 struct msghdr mh; 1352 union { 1353 struct cmsghdr hdr; 1354 char buf[CMSG_SPACE(sizeof(int))]; 1355 } cmsgbuf; 1356 struct cmsghdr *cmsg; 1357 struct iovec iov; 1358 char c = '\0'; 1359 ssize_t r; 1360 struct pollfd pfd; 1361 1362 /* Avoid obvious stupidity */ 1363 if (isatty(STDOUT_FILENO)) 1364 errx(1, "Cannot pass file descriptor to tty"); 1365 1366 memset(&mh, 0, sizeof(mh)); 1367 memset(&cmsgbuf, 0, sizeof(cmsgbuf)); 1368 memset(&iov, 0, sizeof(iov)); 1369 1370 mh.msg_control = &cmsgbuf.buf; 1371 mh.msg_controllen = sizeof(cmsgbuf.buf); 1372 cmsg = CMSG_FIRSTHDR(&mh); 1373 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1374 cmsg->cmsg_level = SOL_SOCKET; 1375 cmsg->cmsg_type = SCM_RIGHTS; 1376 *(int *)CMSG_DATA(cmsg) = nfd; 1377 1378 iov.iov_base = &c; 1379 iov.iov_len = 1; 1380 mh.msg_iov = &iov; 1381 mh.msg_iovlen = 1; 1382 1383 memset(&pfd, 0, sizeof(pfd)); 1384 pfd.fd = STDOUT_FILENO; 1385 pfd.events = POLLOUT; 1386 for (;;) { 1387 r = sendmsg(STDOUT_FILENO, &mh, 0); 1388 if (r == -1) { 1389 if (errno == EAGAIN || errno == EINTR) { 1390 if (poll(&pfd, 1, -1) == -1) 1391 err(1, "poll"); 1392 continue; 1393 } 1394 err(1, "sendmsg"); 1395 } else if (r != 1) 1396 errx(1, "sendmsg: unexpected return value %zd", r); 1397 else 1398 break; 1399 } 1400 exit(0); 1401 } 1402 1403 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1404 void 1405 atelnet(int nfd, unsigned char *buf, unsigned int size) 1406 { 1407 unsigned char *p, *end; 1408 unsigned char obuf[4]; 1409 1410 if (size < 3) 1411 return; 1412 end = buf + size - 2; 1413 1414 for (p = buf; p < end; p++) { 1415 if (*p != IAC) 1416 continue; 1417 1418 obuf[0] = IAC; 1419 p++; 1420 if ((*p == WILL) || (*p == WONT)) 1421 obuf[1] = DONT; 1422 else if ((*p == DO) || (*p == DONT)) 1423 obuf[1] = WONT; 1424 else 1425 continue; 1426 1427 p++; 1428 obuf[2] = *p; 1429 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1430 warn("Write Error!"); 1431 } 1432 } 1433 1434 int 1435 strtoport(char *portstr, int udp) 1436 { 1437 struct servent *entry; 1438 const char *errstr; 1439 char *proto; 1440 int port = -1; 1441 1442 proto = udp ? "udp" : "tcp"; 1443 1444 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1445 if (errstr == NULL) 1446 return port; 1447 if (errno != EINVAL) 1448 errx(1, "port number %s: %s", errstr, portstr); 1449 if ((entry = getservbyname(portstr, proto)) == NULL) 1450 errx(1, "service \"%s\" unknown", portstr); 1451 return ntohs(entry->s_port); 1452 } 1453 1454 /* 1455 * build_ports() 1456 * Build an array of ports in portlist[], listing each port 1457 * that we should try to connect to. 1458 */ 1459 void 1460 build_ports(char *p) 1461 { 1462 char *n; 1463 int hi, lo, cp; 1464 int x = 0; 1465 1466 if (isdigit((unsigned char)*p) && (n = strchr(p, '-')) != NULL) { 1467 *n = '\0'; 1468 n++; 1469 1470 /* Make sure the ports are in order: lowest->highest. */ 1471 hi = strtoport(n, uflag); 1472 lo = strtoport(p, uflag); 1473 if (lo > hi) { 1474 cp = hi; 1475 hi = lo; 1476 lo = cp; 1477 } 1478 1479 /* 1480 * Initialize portlist with a random permutation. Based on 1481 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1482 */ 1483 if (rflag) { 1484 for (x = 0; x <= hi - lo; x++) { 1485 cp = arc4random_uniform(x + 1); 1486 portlist[x] = portlist[cp]; 1487 if (asprintf(&portlist[cp], "%d", x + lo) == -1) 1488 err(1, "asprintf"); 1489 } 1490 } else { /* Load ports sequentially. */ 1491 for (cp = lo; cp <= hi; cp++) { 1492 if (asprintf(&portlist[x], "%d", cp) == -1) 1493 err(1, "asprintf"); 1494 x++; 1495 } 1496 } 1497 } else { 1498 char *tmp; 1499 1500 hi = strtoport(p, uflag); 1501 if (asprintf(&tmp, "%d", hi) != -1) 1502 portlist[0] = tmp; 1503 else 1504 err(1, NULL); 1505 } 1506 } 1507 1508 /* 1509 * udptest() 1510 * Do a few writes to see if the UDP port is there. 1511 * Fails once PF state table is full. 1512 */ 1513 int 1514 udptest(int s) 1515 { 1516 int i, ret; 1517 1518 /* Only write to the socket in scan mode or interactive mode. */ 1519 if (!zflag && !isatty(STDIN_FILENO)) 1520 return 0; 1521 1522 for (i = 0; i <= 3; i++) { 1523 if (write(s, "X", 1) == 1) 1524 ret = 1; 1525 else 1526 ret = -1; 1527 } 1528 return ret; 1529 } 1530 1531 void 1532 connection_info(const char *host, const char *port, const char *proto, 1533 const char *ipaddr) 1534 { 1535 struct servent *sv; 1536 char *service = "*"; 1537 1538 /* Look up service name unless -n. */ 1539 if (!nflag) { 1540 sv = getservbyport(ntohs(atoi(port)), proto); 1541 if (sv != NULL) 1542 service = sv->s_name; 1543 } 1544 1545 fprintf(stderr, "Connection to %s", host); 1546 1547 /* 1548 * if we aren't connecting thru a proxy and 1549 * there is something to report, print IP 1550 */ 1551 if (!nflag && !xflag && strcmp(host, ipaddr) != 0) 1552 fprintf(stderr, " (%s)", ipaddr); 1553 1554 fprintf(stderr, " %s port [%s/%s] succeeded!\n", port, proto, service); 1555 } 1556 1557 void 1558 set_common_sockopts(int s, int af) 1559 { 1560 int x = 1; 1561 1562 if (Sflag) { 1563 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1564 &x, sizeof(x)) == -1) 1565 err(1, NULL); 1566 } 1567 if (Dflag) { 1568 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1569 &x, sizeof(x)) == -1) 1570 err(1, NULL); 1571 } 1572 if (Tflag != -1) { 1573 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1574 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1575 err(1, "set IP ToS"); 1576 1577 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1578 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1579 err(1, "set IPv6 traffic class"); 1580 } 1581 if (Iflag) { 1582 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1583 &Iflag, sizeof(Iflag)) == -1) 1584 err(1, "set TCP receive buffer size"); 1585 } 1586 if (Oflag) { 1587 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1588 &Oflag, sizeof(Oflag)) == -1) 1589 err(1, "set TCP send buffer size"); 1590 } 1591 1592 if (ttl != -1) { 1593 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1594 IP_TTL, &ttl, sizeof(ttl))) 1595 err(1, "set IP TTL"); 1596 1597 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1598 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1599 err(1, "set IPv6 unicast hops"); 1600 } 1601 1602 if (minttl != -1) { 1603 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1604 IP_MINTTL, &minttl, sizeof(minttl))) 1605 err(1, "set IP min TTL"); 1606 1607 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1608 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1609 err(1, "set IPv6 min hop count"); 1610 } 1611 } 1612 1613 int 1614 process_tos_opt(char *s, int *val) 1615 { 1616 /* DiffServ Codepoints and other TOS mappings */ 1617 const struct toskeywords { 1618 const char *keyword; 1619 int val; 1620 } *t, toskeywords[] = { 1621 { "af11", IPTOS_DSCP_AF11 }, 1622 { "af12", IPTOS_DSCP_AF12 }, 1623 { "af13", IPTOS_DSCP_AF13 }, 1624 { "af21", IPTOS_DSCP_AF21 }, 1625 { "af22", IPTOS_DSCP_AF22 }, 1626 { "af23", IPTOS_DSCP_AF23 }, 1627 { "af31", IPTOS_DSCP_AF31 }, 1628 { "af32", IPTOS_DSCP_AF32 }, 1629 { "af33", IPTOS_DSCP_AF33 }, 1630 { "af41", IPTOS_DSCP_AF41 }, 1631 { "af42", IPTOS_DSCP_AF42 }, 1632 { "af43", IPTOS_DSCP_AF43 }, 1633 { "critical", IPTOS_PREC_CRITIC_ECP }, 1634 { "cs0", IPTOS_DSCP_CS0 }, 1635 { "cs1", IPTOS_DSCP_CS1 }, 1636 { "cs2", IPTOS_DSCP_CS2 }, 1637 { "cs3", IPTOS_DSCP_CS3 }, 1638 { "cs4", IPTOS_DSCP_CS4 }, 1639 { "cs5", IPTOS_DSCP_CS5 }, 1640 { "cs6", IPTOS_DSCP_CS6 }, 1641 { "cs7", IPTOS_DSCP_CS7 }, 1642 { "ef", IPTOS_DSCP_EF }, 1643 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1644 { "lowdelay", IPTOS_LOWDELAY }, 1645 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1646 { "reliability", IPTOS_RELIABILITY }, 1647 { "throughput", IPTOS_THROUGHPUT }, 1648 { NULL, -1 }, 1649 }; 1650 1651 for (t = toskeywords; t->keyword != NULL; t++) { 1652 if (strcmp(s, t->keyword) == 0) { 1653 *val = t->val; 1654 return 1; 1655 } 1656 } 1657 1658 return 0; 1659 } 1660 1661 int 1662 process_tls_opt(char *s, int *flags) 1663 { 1664 size_t len; 1665 char *v; 1666 1667 const struct tlskeywords { 1668 const char *keyword; 1669 int flag; 1670 char **value; 1671 } *t, tlskeywords[] = { 1672 { "ciphers", -1, &tls_ciphers }, 1673 { "clientcert", TLS_CCERT, NULL }, 1674 { "muststaple", TLS_MUSTSTAPLE, NULL }, 1675 { "noverify", TLS_NOVERIFY, NULL }, 1676 { "noname", TLS_NONAME, NULL }, 1677 { "protocols", -1, &tls_protocols }, 1678 { NULL, -1, NULL }, 1679 }; 1680 1681 len = strlen(s); 1682 if ((v = strchr(s, '=')) != NULL) { 1683 len = v - s; 1684 v++; 1685 } 1686 1687 for (t = tlskeywords; t->keyword != NULL; t++) { 1688 if (strlen(t->keyword) == len && 1689 strncmp(s, t->keyword, len) == 0) { 1690 if (t->value != NULL) { 1691 if (v == NULL) 1692 errx(1, "invalid tls value `%s'", s); 1693 *t->value = v; 1694 } else { 1695 *flags |= t->flag; 1696 } 1697 return 1; 1698 } 1699 } 1700 return 0; 1701 } 1702 1703 void 1704 save_peer_cert(struct tls *tls_ctx, FILE *fp) 1705 { 1706 const char *pem; 1707 size_t plen; 1708 1709 if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL) 1710 errx(1, "Can't get peer certificate"); 1711 if (fprintf(fp, "%.*s", (int)plen, pem) < 0) 1712 err(1, "unable to save peer cert"); 1713 if (fflush(fp) != 0) 1714 err(1, "unable to flush peer cert"); 1715 } 1716 1717 void 1718 report_tls(struct tls *tls_ctx, char *host) 1719 { 1720 time_t t; 1721 const char *ocsp_url; 1722 1723 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1724 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1725 fprintf(stderr, "Peer name: %s\n", 1726 tls_expectname ? tls_expectname : host); 1727 if (tls_peer_cert_subject(tls_ctx)) 1728 fprintf(stderr, "Subject: %s\n", 1729 tls_peer_cert_subject(tls_ctx)); 1730 if (tls_peer_cert_issuer(tls_ctx)) 1731 fprintf(stderr, "Issuer: %s\n", 1732 tls_peer_cert_issuer(tls_ctx)); 1733 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1734 fprintf(stderr, "Valid From: %s", ctime(&t)); 1735 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1736 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1737 if (tls_peer_cert_hash(tls_ctx)) 1738 fprintf(stderr, "Cert Hash: %s\n", 1739 tls_peer_cert_hash(tls_ctx)); 1740 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1741 if (ocsp_url != NULL) 1742 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1743 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1744 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1745 fprintf(stderr, "OCSP Stapling: %s\n", 1746 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1747 tls_peer_ocsp_result(tls_ctx)); 1748 fprintf(stderr, 1749 " response_status=%d cert_status=%d crl_reason=%d\n", 1750 tls_peer_ocsp_response_status(tls_ctx), 1751 tls_peer_ocsp_cert_status(tls_ctx), 1752 tls_peer_ocsp_crl_reason(tls_ctx)); 1753 t = tls_peer_ocsp_this_update(tls_ctx); 1754 fprintf(stderr, " this update: %s", 1755 t != -1 ? ctime(&t) : "\n"); 1756 t = tls_peer_ocsp_next_update(tls_ctx); 1757 fprintf(stderr, " next update: %s", 1758 t != -1 ? ctime(&t) : "\n"); 1759 t = tls_peer_ocsp_revocation_time(tls_ctx); 1760 fprintf(stderr, " revocation: %s", 1761 t != -1 ? ctime(&t) : "\n"); 1762 break; 1763 case -1: 1764 break; 1765 default: 1766 fprintf(stderr, 1767 "OCSP Stapling: failure - response_status %d (%s)\n", 1768 tls_peer_ocsp_response_status(tls_ctx), 1769 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1770 tls_peer_ocsp_result(tls_ctx)); 1771 break; 1772 } 1773 } 1774 1775 void 1776 report_sock(const char *msg, const struct sockaddr *sa, socklen_t salen, 1777 char *path) 1778 { 1779 char host[NI_MAXHOST], port[NI_MAXSERV]; 1780 int herr; 1781 int flags = NI_NUMERICSERV; 1782 1783 if (path != NULL) { 1784 fprintf(stderr, "%s on %s\n", msg, path); 1785 return; 1786 } 1787 1788 if (nflag) 1789 flags |= NI_NUMERICHOST; 1790 1791 herr = getnameinfo(sa, salen, host, sizeof(host), port, sizeof(port), 1792 flags); 1793 switch (herr) { 1794 case 0: 1795 break; 1796 case EAI_SYSTEM: 1797 err(1, "getnameinfo"); 1798 default: 1799 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1800 } 1801 1802 fprintf(stderr, "%s on %s %s\n", msg, host, port); 1803 } 1804 1805 void 1806 help(void) 1807 { 1808 usage(0); 1809 fprintf(stderr, "\tCommand Summary:\n\ 1810 \t-4 Use IPv4\n\ 1811 \t-6 Use IPv6\n\ 1812 \t-C certfile Public key file\n\ 1813 \t-c Use TLS\n\ 1814 \t-D Enable the debug socket option\n\ 1815 \t-d Detach from stdin\n\ 1816 \t-e name\t Required name in peer certificate\n\ 1817 \t-F Pass socket fd\n\ 1818 \t-H hash\t Hash string of peer certificate\n\ 1819 \t-h This help text\n\ 1820 \t-I length TCP receive buffer length\n\ 1821 \t-i interval Delay interval for lines sent, ports scanned\n\ 1822 \t-K keyfile Private key file\n\ 1823 \t-k Keep inbound sockets open for multiple connects\n\ 1824 \t-l Listen mode, for inbound connects\n\ 1825 \t-M ttl Outgoing TTL / Hop Limit\n\ 1826 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1827 \t-N Shutdown the network socket after EOF on stdin\n\ 1828 \t-n Suppress name/port resolutions\n\ 1829 \t-O length TCP send buffer length\n\ 1830 \t-o staplefile Staple file\n\ 1831 \t-P proxyuser\tUsername for proxy authentication\n\ 1832 \t-p port\t Specify local port for remote connects\n\ 1833 \t-R CAfile CA bundle\n\ 1834 \t-r Randomize remote ports\n\ 1835 \t-S Enable the TCP MD5 signature option\n\ 1836 \t-s sourceaddr Local source address\n\ 1837 \t-T keyword TOS value or TLS options\n\ 1838 \t-t Answer TELNET negotiation\n\ 1839 \t-U Use UNIX domain socket\n\ 1840 \t-u UDP mode\n\ 1841 \t-V rtable Specify alternate routing table\n\ 1842 \t-v Verbose\n\ 1843 \t-W recvlimit Terminate after receiving a number of packets\n\ 1844 \t-w timeout Timeout for connects and final net reads\n\ 1845 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1846 \t-x addr[:port]\tSpecify proxy address and port\n\ 1847 \t-Z Peer certificate file\n\ 1848 \t-z Zero-I/O mode [used for scanning]\n\ 1849 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1850 exit(1); 1851 } 1852 1853 void 1854 usage(int ret) 1855 { 1856 fprintf(stderr, 1857 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1858 "[-H hash] [-I length]\n" 1859 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1860 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1861 "[-R CAfile]\n" 1862 "\t [-s sourceaddr] [-T keyword] [-V rtable] [-W recvlimit] " 1863 "[-w timeout]\n" 1864 "\t [-X proxy_protocol] [-x proxy_address[:port]] " 1865 "[-Z peercertfile]\n" 1866 "\t [destination] [port]\n"); 1867 if (ret) 1868 exit(1); 1869 } 1870