1 /* $OpenBSD: netcat.c,v 1.212 2019/11/17 17:38:33 deraadt 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 int unix_bind(char *, int); 135 int unix_connect(char *); 136 int unix_listen(char *); 137 void set_common_sockopts(int, int); 138 int process_tos_opt(char *, int *); 139 int process_tls_opt(char *, int *); 140 void save_peer_cert(struct tls *_tls_ctx, FILE *_fp); 141 void report_sock(const char *, const struct sockaddr *, socklen_t, char *); 142 void report_tls(struct tls *tls_ctx, char * host); 143 void usage(int); 144 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 145 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 146 void tls_setup_client(struct tls *, int, char *); 147 struct tls *tls_setup_server(struct tls *, int, char *); 148 149 int 150 main(int argc, char *argv[]) 151 { 152 int ch, s = -1, ret, socksv; 153 char *host, *uport; 154 char ipaddr[NI_MAXHOST]; 155 struct addrinfo hints; 156 struct servent *sv; 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 sv = NULL; 172 Rflag = tls_default_ca_cert_file(); 173 174 signal(SIGPIPE, SIG_IGN); 175 176 while ((ch = getopt(argc, argv, 177 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z")) 178 != -1) { 179 switch (ch) { 180 case '4': 181 family = AF_INET; 182 break; 183 case '6': 184 family = AF_INET6; 185 break; 186 case 'U': 187 family = AF_UNIX; 188 break; 189 case 'X': 190 if (strcasecmp(optarg, "connect") == 0) 191 socksv = -1; /* HTTP proxy CONNECT */ 192 else if (strcmp(optarg, "4") == 0) 193 socksv = 4; /* SOCKS v.4 */ 194 else if (strcmp(optarg, "5") == 0) 195 socksv = 5; /* SOCKS v.5 */ 196 else 197 errx(1, "unsupported proxy protocol"); 198 break; 199 case 'C': 200 Cflag = optarg; 201 break; 202 case 'c': 203 usetls = 1; 204 break; 205 case 'd': 206 dflag = 1; 207 break; 208 case 'e': 209 tls_expectname = optarg; 210 break; 211 case 'F': 212 Fflag = 1; 213 break; 214 case 'H': 215 tls_expecthash = optarg; 216 break; 217 case 'h': 218 help(); 219 break; 220 case 'i': 221 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 222 if (errstr) 223 errx(1, "interval %s: %s", errstr, optarg); 224 break; 225 case 'K': 226 Kflag = optarg; 227 break; 228 case 'k': 229 kflag = 1; 230 break; 231 case 'l': 232 lflag = 1; 233 break; 234 case 'M': 235 ttl = strtonum(optarg, 0, 255, &errstr); 236 if (errstr) 237 errx(1, "ttl is %s", errstr); 238 break; 239 case 'm': 240 minttl = strtonum(optarg, 0, 255, &errstr); 241 if (errstr) 242 errx(1, "minttl is %s", errstr); 243 break; 244 case 'N': 245 Nflag = 1; 246 break; 247 case 'n': 248 nflag = 1; 249 break; 250 case 'P': 251 Pflag = optarg; 252 break; 253 case 'p': 254 pflag = optarg; 255 break; 256 case 'R': 257 tls_cachanged = 1; 258 Rflag = optarg; 259 break; 260 case 'r': 261 rflag = 1; 262 break; 263 case 's': 264 sflag = optarg; 265 break; 266 case 't': 267 tflag = 1; 268 break; 269 case 'u': 270 uflag = 1; 271 break; 272 case 'V': 273 rtableid = (int)strtonum(optarg, 0, 274 RT_TABLEID_MAX, &errstr); 275 if (errstr) 276 errx(1, "rtable %s: %s", errstr, optarg); 277 break; 278 case 'v': 279 vflag = 1; 280 break; 281 case 'W': 282 recvlimit = strtonum(optarg, 1, INT_MAX, &errstr); 283 if (errstr) 284 errx(1, "receive limit %s: %s", errstr, optarg); 285 break; 286 case 'w': 287 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 288 if (errstr) 289 errx(1, "timeout %s: %s", errstr, optarg); 290 timeout *= 1000; 291 break; 292 case 'x': 293 xflag = 1; 294 if ((proxy = strdup(optarg)) == NULL) 295 err(1, NULL); 296 break; 297 case 'Z': 298 if (strcmp(optarg, "-") == 0) 299 Zflag = stderr; 300 else if ((Zflag = fopen(optarg, "w")) == NULL) 301 err(1, "can't open %s", optarg); 302 break; 303 case 'z': 304 zflag = 1; 305 break; 306 case 'D': 307 Dflag = 1; 308 break; 309 case 'I': 310 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 311 if (errstr != NULL) 312 errx(1, "TCP receive window %s: %s", 313 errstr, optarg); 314 break; 315 case 'O': 316 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 317 if (errstr != NULL) 318 errx(1, "TCP send window %s: %s", 319 errstr, optarg); 320 break; 321 case 'o': 322 oflag = optarg; 323 break; 324 case 'S': 325 Sflag = 1; 326 break; 327 case 'T': 328 errstr = NULL; 329 errno = 0; 330 if (process_tls_opt(optarg, &TLSopt)) 331 break; 332 if (process_tos_opt(optarg, &Tflag)) 333 break; 334 if (strlen(optarg) > 1 && optarg[0] == '0' && 335 optarg[1] == 'x') 336 Tflag = (int)strtol(optarg, NULL, 16); 337 else 338 Tflag = (int)strtonum(optarg, 0, 255, 339 &errstr); 340 if (Tflag < 0 || Tflag > 255 || errstr || errno) 341 errx(1, "illegal tos/tls value %s", optarg); 342 break; 343 default: 344 usage(1); 345 } 346 } 347 argc -= optind; 348 argv += optind; 349 350 if (rtableid >= 0) 351 if (setrtable(rtableid) == -1) 352 err(1, "setrtable"); 353 354 /* Cruft to make sure options are clean, and used properly. */ 355 if (argc == 1 && family == AF_UNIX) { 356 host = argv[0]; 357 } else if (argc == 1 && lflag) { 358 uport = argv[0]; 359 } else if (argc == 2) { 360 host = argv[0]; 361 uport = argv[1]; 362 } else 363 usage(1); 364 365 if (usetls) { 366 if (Cflag && unveil(Cflag, "r") == -1) 367 err(1, "unveil"); 368 if (unveil(Rflag, "r") == -1) 369 err(1, "unveil"); 370 if (Kflag && unveil(Kflag, "r") == -1) 371 err(1, "unveil"); 372 if (oflag && unveil(oflag, "r") == -1) 373 err(1, "unveil"); 374 } else { 375 if (family == AF_UNIX) { 376 if (unveil(host, "rwc") == -1) 377 err(1, "unveil"); 378 if (uflag && !lflag) { 379 if (unveil(sflag ? sflag : "/tmp", "rwc") == -1) 380 err(1, "unveil"); 381 } 382 } else { 383 /* no filesystem visibility */ 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 == -1) 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 == -1) 592 err(1, "recvfrom"); 593 594 rv = connect(s, (struct sockaddr *)&z, len); 595 if (rv == -1) 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) == -1) 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 ipaddr); 679 680 if (s == -1) 681 continue; 682 683 ret = 0; 684 if (vflag || zflag) { 685 /* For UDP, make sure we are connected. */ 686 if (uflag) { 687 if (udptest(s) == -1) { 688 ret = 1; 689 continue; 690 } 691 } 692 693 /* Don't look up port if -n. */ 694 if (nflag) 695 sv = NULL; 696 else { 697 sv = getservbyport( 698 ntohs(atoi(portlist[i])), 699 uflag ? "udp" : "tcp"); 700 } 701 702 fprintf(stderr, "Connection to %s", host); 703 704 /* 705 * if we aren't connecting thru a proxy and 706 * there is something to report, print IP 707 */ 708 if (!nflag && !xflag 709 && (strcmp(host, ipaddr) != 0)) 710 fprintf(stderr, " (%s)", ipaddr); 711 712 fprintf(stderr, " %s port [%s/%s] succeeded!\n", 713 portlist[i], uflag ? "udp" : "tcp", 714 sv ? sv->s_name : "*"); 715 } 716 if (Fflag) 717 fdpass(s); 718 else { 719 if (usetls) 720 tls_setup_client(tls_ctx, s, host); 721 if (!zflag) 722 readwrite(s, tls_ctx); 723 if (tls_ctx) 724 timeout_tls(s, tls_ctx, tls_close); 725 } 726 } 727 } 728 729 if (s != -1) 730 close(s); 731 tls_free(tls_ctx); 732 tls_config_free(tls_cfg); 733 734 return ret; 735 } 736 737 /* 738 * unix_bind() 739 * Returns a unix socket bound to the given path 740 */ 741 int 742 unix_bind(char *path, int flags) 743 { 744 struct sockaddr_un s_un; 745 int s, save_errno; 746 747 /* Create unix domain socket. */ 748 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 749 0)) == -1) 750 return -1; 751 752 memset(&s_un, 0, sizeof(struct sockaddr_un)); 753 s_un.sun_family = AF_UNIX; 754 755 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 756 sizeof(s_un.sun_path)) { 757 close(s); 758 errno = ENAMETOOLONG; 759 return -1; 760 } 761 762 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { 763 save_errno = errno; 764 close(s); 765 errno = save_errno; 766 return -1; 767 } 768 if (vflag) 769 report_sock("Bound", NULL, 0, path); 770 771 return s; 772 } 773 774 int 775 timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) 776 { 777 struct pollfd pfd; 778 int ret; 779 780 while ((ret = (*func)(tls_ctx)) != 0) { 781 if (ret == TLS_WANT_POLLIN) 782 pfd.events = POLLIN; 783 else if (ret == TLS_WANT_POLLOUT) 784 pfd.events = POLLOUT; 785 else 786 break; 787 pfd.fd = s; 788 if ((ret = poll(&pfd, 1, timeout)) == 1) 789 continue; 790 else if (ret == 0) { 791 errno = ETIMEDOUT; 792 ret = -1; 793 break; 794 } else 795 err(1, "poll failed"); 796 } 797 798 return ret; 799 } 800 801 void 802 tls_setup_client(struct tls *tls_ctx, int s, char *host) 803 { 804 const char *errstr; 805 806 if (tls_connect_socket(tls_ctx, s, 807 tls_expectname ? tls_expectname : host) == -1) { 808 errx(1, "tls connection failed (%s)", 809 tls_error(tls_ctx)); 810 } 811 if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { 812 if ((errstr = tls_error(tls_ctx)) == NULL) 813 errstr = strerror(errno); 814 errx(1, "tls handshake failed (%s)", errstr); 815 } 816 if (vflag) 817 report_tls(tls_ctx, host); 818 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 819 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 820 errx(1, "peer certificate is not %s", tls_expecthash); 821 if (Zflag) { 822 save_peer_cert(tls_ctx, Zflag); 823 if (Zflag != stderr && (fclose(Zflag) != 0)) 824 err(1, "fclose failed saving peer cert"); 825 } 826 } 827 828 struct tls * 829 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 830 { 831 struct tls *tls_cctx; 832 const char *errstr; 833 834 if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { 835 warnx("tls accept failed (%s)", tls_error(tls_ctx)); 836 } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { 837 if ((errstr = tls_error(tls_cctx)) == NULL) 838 errstr = strerror(errno); 839 warnx("tls handshake failed (%s)", errstr); 840 } else { 841 int gotcert = tls_peer_cert_provided(tls_cctx); 842 843 if (vflag && gotcert) 844 report_tls(tls_cctx, host); 845 if ((TLSopt & TLS_CCERT) && !gotcert) 846 warnx("No client certificate provided"); 847 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 848 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 849 warnx("peer certificate is not %s", tls_expecthash); 850 else if (gotcert && tls_expectname && 851 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 852 warnx("name (%s) not found in client cert", 853 tls_expectname); 854 else { 855 return tls_cctx; 856 } 857 } 858 return NULL; 859 } 860 861 /* 862 * unix_connect() 863 * Returns a socket connected to a local unix socket. Returns -1 on failure. 864 */ 865 int 866 unix_connect(char *path) 867 { 868 struct sockaddr_un s_un; 869 int s, save_errno; 870 871 if (uflag) { 872 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) == -1) 873 return -1; 874 } else { 875 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) == -1) 876 return -1; 877 } 878 879 memset(&s_un, 0, sizeof(struct sockaddr_un)); 880 s_un.sun_family = AF_UNIX; 881 882 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 883 sizeof(s_un.sun_path)) { 884 close(s); 885 errno = ENAMETOOLONG; 886 return -1; 887 } 888 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { 889 save_errno = errno; 890 close(s); 891 errno = save_errno; 892 return -1; 893 } 894 return s; 895 896 } 897 898 /* 899 * unix_listen() 900 * Create a unix domain socket, and listen on it. 901 */ 902 int 903 unix_listen(char *path) 904 { 905 int s; 906 907 if ((s = unix_bind(path, 0)) == -1) 908 return -1; 909 if (listen(s, 5) == -1) { 910 close(s); 911 return -1; 912 } 913 if (vflag) 914 report_sock("Listening", NULL, 0, path); 915 916 return s; 917 } 918 919 /* 920 * remote_connect() 921 * Returns a socket connected to a remote host. Properly binds to a local 922 * port or source address if needed. Returns -1 on failure. 923 */ 924 int 925 remote_connect(const char *host, const char *port, struct addrinfo hints, 926 char *ipaddr) 927 { 928 struct addrinfo *res, *res0; 929 int s = -1, error, herr, on = 1, save_errno; 930 931 if ((error = getaddrinfo(host, port, &hints, &res0))) 932 errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, 933 port, gai_strerror(error)); 934 935 for (res = res0; res; res = res->ai_next) { 936 if ((s = socket(res->ai_family, res->ai_socktype | 937 SOCK_NONBLOCK, res->ai_protocol)) == -1) 938 continue; 939 940 /* Bind to a local port or source address if specified. */ 941 if (sflag || pflag) { 942 struct addrinfo ahints, *ares; 943 944 /* try SO_BINDANY, but don't insist */ 945 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 946 memset(&ahints, 0, sizeof(struct addrinfo)); 947 ahints.ai_family = res->ai_family; 948 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 949 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 950 ahints.ai_flags = AI_PASSIVE; 951 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 952 errx(1, "getaddrinfo: %s", gai_strerror(error)); 953 954 if (bind(s, (struct sockaddr *)ares->ai_addr, 955 ares->ai_addrlen) == -1) 956 err(1, "bind failed"); 957 freeaddrinfo(ares); 958 } 959 960 set_common_sockopts(s, res->ai_family); 961 962 if (ipaddr != NULL) { 963 herr = getnameinfo(res->ai_addr, res->ai_addrlen, 964 ipaddr, NI_MAXHOST, NULL, 0, NI_NUMERICHOST); 965 switch (herr) { 966 case 0: 967 break; 968 case EAI_SYSTEM: 969 err(1, "getnameinfo"); 970 default: 971 errx(1, "getnameinfo: %s", gai_strerror(herr)); 972 } 973 } 974 975 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 976 break; 977 978 if (vflag) { 979 /* only print IP if there is something to report */ 980 if (nflag || ipaddr == NULL || 981 (strncmp(host, ipaddr, NI_MAXHOST) == 0)) 982 warn("connect to %s port %s (%s) failed", host, 983 port, uflag ? "udp" : "tcp"); 984 else 985 warn("connect to %s (%s) port %s (%s) failed", 986 host, ipaddr, port, uflag ? "udp" : "tcp"); 987 } 988 989 save_errno = errno; 990 close(s); 991 errno = save_errno; 992 s = -1; 993 } 994 995 freeaddrinfo(res0); 996 997 return s; 998 } 999 1000 int 1001 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 1002 { 1003 struct pollfd pfd; 1004 socklen_t optlen; 1005 int optval; 1006 int ret; 1007 1008 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 1009 pfd.fd = s; 1010 pfd.events = POLLOUT; 1011 if ((ret = poll(&pfd, 1, timeout)) == 1) { 1012 optlen = sizeof(optval); 1013 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 1014 &optval, &optlen)) == 0) { 1015 errno = optval; 1016 ret = optval == 0 ? 0 : -1; 1017 } 1018 } else if (ret == 0) { 1019 errno = ETIMEDOUT; 1020 ret = -1; 1021 } else 1022 err(1, "poll failed"); 1023 } 1024 1025 return ret; 1026 } 1027 1028 /* 1029 * local_listen() 1030 * Returns a socket listening on a local port, binds to specified source 1031 * address. Returns -1 on failure. 1032 */ 1033 int 1034 local_listen(const char *host, const char *port, struct addrinfo hints) 1035 { 1036 struct addrinfo *res, *res0; 1037 int s = -1, ret, x = 1, save_errno; 1038 int error; 1039 1040 /* Allow nodename to be null. */ 1041 hints.ai_flags |= AI_PASSIVE; 1042 1043 /* 1044 * In the case of binding to a wildcard address 1045 * default to binding to an ipv4 address. 1046 */ 1047 if (host == NULL && hints.ai_family == AF_UNSPEC) 1048 hints.ai_family = AF_INET; 1049 1050 if ((error = getaddrinfo(host, port, &hints, &res0))) 1051 errx(1, "getaddrinfo: %s", gai_strerror(error)); 1052 1053 for (res = res0; res; res = res->ai_next) { 1054 if ((s = socket(res->ai_family, res->ai_socktype, 1055 res->ai_protocol)) == -1) 1056 continue; 1057 1058 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 1059 if (ret == -1) 1060 err(1, NULL); 1061 1062 set_common_sockopts(s, res->ai_family); 1063 1064 if (bind(s, (struct sockaddr *)res->ai_addr, 1065 res->ai_addrlen) == 0) 1066 break; 1067 1068 save_errno = errno; 1069 close(s); 1070 errno = save_errno; 1071 s = -1; 1072 } 1073 1074 if (!uflag && s != -1) { 1075 if (listen(s, 1) == -1) 1076 err(1, "listen"); 1077 } 1078 if (vflag && s != -1) { 1079 struct sockaddr_storage ss; 1080 socklen_t len; 1081 1082 len = sizeof(ss); 1083 if (getsockname(s, (struct sockaddr *)&ss, &len) == -1) 1084 err(1, "getsockname"); 1085 report_sock(uflag ? "Bound" : "Listening", 1086 (struct sockaddr *)&ss, len, NULL); 1087 } 1088 1089 freeaddrinfo(res0); 1090 1091 return s; 1092 } 1093 1094 /* 1095 * readwrite() 1096 * Loop that polls on the network file descriptor and stdin. 1097 */ 1098 void 1099 readwrite(int net_fd, struct tls *tls_ctx) 1100 { 1101 struct pollfd pfd[4]; 1102 int gone[4] = { 0 }; 1103 int stdin_fd = STDIN_FILENO; 1104 int stdout_fd = STDOUT_FILENO; 1105 unsigned char netinbuf[BUFSIZE]; 1106 size_t netinbufpos = 0; 1107 unsigned char stdinbuf[BUFSIZE]; 1108 size_t stdinbufpos = 0; 1109 int n, num_fds, shutdown_netin, shutdown_netout; 1110 ssize_t ret; 1111 1112 /* don't read from stdin if requested */ 1113 if (dflag) 1114 stdin_fd = -1; 1115 1116 /* stdin */ 1117 pfd[POLL_STDIN].fd = stdin_fd; 1118 pfd[POLL_STDIN].events = POLLIN; 1119 1120 /* network out */ 1121 pfd[POLL_NETOUT].fd = net_fd; 1122 pfd[POLL_NETOUT].events = 0; 1123 1124 /* network in */ 1125 pfd[POLL_NETIN].fd = net_fd; 1126 pfd[POLL_NETIN].events = POLLIN; 1127 1128 /* stdout */ 1129 pfd[POLL_STDOUT].fd = stdout_fd; 1130 pfd[POLL_STDOUT].events = 0; 1131 1132 /* used to indicate we wish to shut down the network socket */ 1133 shutdown_netin = shutdown_netout = 0; 1134 1135 while (1) { 1136 /* both inputs are gone, buffers are empty, we are done */ 1137 if (gone[POLL_STDIN] && gone[POLL_NETIN] && 1138 stdinbufpos == 0 && netinbufpos == 0) 1139 return; 1140 /* both outputs are gone, we can't continue */ 1141 if (gone[POLL_NETOUT] && gone[POLL_STDOUT]) 1142 return; 1143 /* listen and net in gone, queues empty, done */ 1144 if (lflag && gone[POLL_NETIN] && stdinbufpos == 0 1145 && netinbufpos == 0) 1146 return; 1147 1148 /* help says -i is for "wait between lines sent". We read and 1149 * write arbitrary amounts of data, and we don't want to start 1150 * scanning for newlines, so this is as good as it gets */ 1151 if (iflag) 1152 sleep(iflag); 1153 1154 /* If it's gone, take it away from poll */ 1155 for (n = 0; n < 4; n++) { 1156 if (gone[n]) 1157 pfd[n].events = pfd[n].revents = 0; 1158 } 1159 1160 /* poll */ 1161 num_fds = poll(pfd, 4, timeout); 1162 1163 /* treat poll errors */ 1164 if (num_fds == -1) 1165 err(1, "polling error"); 1166 1167 /* timeout happened */ 1168 if (num_fds == 0) 1169 return; 1170 1171 /* treat socket error conditions */ 1172 for (n = 0; n < 4; n++) { 1173 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1174 gone[n] = 1; 1175 } 1176 } 1177 /* reading is possible after HUP */ 1178 if (pfd[POLL_STDIN].events & POLLIN && 1179 pfd[POLL_STDIN].revents & POLLHUP && 1180 !(pfd[POLL_STDIN].revents & POLLIN)) 1181 gone[POLL_STDIN] = 1; 1182 1183 if (pfd[POLL_NETIN].events & POLLIN && 1184 pfd[POLL_NETIN].revents & POLLHUP && 1185 !(pfd[POLL_NETIN].revents & POLLIN)) 1186 gone[POLL_NETIN] = 1; 1187 1188 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1189 if (Nflag) 1190 shutdown_netout = 1; 1191 gone[POLL_NETOUT] = 1; 1192 } 1193 /* if no net out, stop watching stdin */ 1194 if (gone[POLL_NETOUT]) 1195 gone[POLL_STDIN] = 1; 1196 1197 /* if stdout HUP's, stop watching stdout */ 1198 if (pfd[POLL_STDOUT].revents & POLLHUP) 1199 gone[POLL_STDOUT] = 1; 1200 /* if no stdout, stop watching net in */ 1201 if (gone[POLL_STDOUT]) { 1202 shutdown_netin = 1; 1203 gone[POLL_NETIN] = 1; 1204 } 1205 1206 /* try to read from stdin */ 1207 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1208 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1209 &stdinbufpos, NULL); 1210 if (ret == TLS_WANT_POLLIN) 1211 pfd[POLL_STDIN].events = POLLIN; 1212 else if (ret == TLS_WANT_POLLOUT) 1213 pfd[POLL_STDIN].events = POLLOUT; 1214 else if (ret == 0 || ret == -1) 1215 gone[POLL_STDIN] = 1; 1216 /* read something - poll net out */ 1217 if (stdinbufpos > 0) 1218 pfd[POLL_NETOUT].events = POLLOUT; 1219 /* filled buffer - remove self from polling */ 1220 if (stdinbufpos == BUFSIZE) 1221 pfd[POLL_STDIN].events = 0; 1222 } 1223 /* try to write to network */ 1224 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1225 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1226 &stdinbufpos, tls_ctx); 1227 if (ret == TLS_WANT_POLLIN) 1228 pfd[POLL_NETOUT].events = POLLIN; 1229 else if (ret == TLS_WANT_POLLOUT) 1230 pfd[POLL_NETOUT].events = POLLOUT; 1231 else if (ret == -1) 1232 gone[POLL_NETOUT] = 1; 1233 /* buffer empty - remove self from polling */ 1234 if (stdinbufpos == 0) 1235 pfd[POLL_NETOUT].events = 0; 1236 /* buffer no longer full - poll stdin again */ 1237 if (stdinbufpos < BUFSIZE) 1238 pfd[POLL_STDIN].events = POLLIN; 1239 } 1240 /* try to read from network */ 1241 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1242 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1243 &netinbufpos, tls_ctx); 1244 if (ret == TLS_WANT_POLLIN) 1245 pfd[POLL_NETIN].events = POLLIN; 1246 else if (ret == TLS_WANT_POLLOUT) 1247 pfd[POLL_NETIN].events = POLLOUT; 1248 else if (ret == -1) 1249 gone[POLL_NETIN] = 1; 1250 /* eof on net in - remove from pfd */ 1251 if (ret == 0) { 1252 gone[POLL_NETIN] = 1; 1253 } 1254 if (recvlimit > 0 && ++recvcount >= recvlimit) { 1255 shutdown_netin = 1; 1256 gone[POLL_NETIN] = 1; 1257 gone[POLL_STDIN] = 1; 1258 } 1259 /* read something - poll stdout */ 1260 if (netinbufpos > 0) 1261 pfd[POLL_STDOUT].events = POLLOUT; 1262 /* filled buffer - remove self from polling */ 1263 if (netinbufpos == BUFSIZE) 1264 pfd[POLL_NETIN].events = 0; 1265 /* handle telnet */ 1266 if (tflag) 1267 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1268 netinbufpos); 1269 } 1270 /* try to write to stdout */ 1271 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1272 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1273 &netinbufpos, NULL); 1274 if (ret == TLS_WANT_POLLIN) 1275 pfd[POLL_STDOUT].events = POLLIN; 1276 else if (ret == TLS_WANT_POLLOUT) 1277 pfd[POLL_STDOUT].events = POLLOUT; 1278 else if (ret == -1) 1279 gone[POLL_STDOUT] = 1; 1280 /* buffer empty - remove self from polling */ 1281 if (netinbufpos == 0) 1282 pfd[POLL_STDOUT].events = 0; 1283 /* buffer no longer full - poll net in again */ 1284 if (netinbufpos < BUFSIZE) 1285 pfd[POLL_NETIN].events = POLLIN; 1286 } 1287 1288 /* stdin gone and queue empty? */ 1289 if (gone[POLL_STDIN] && stdinbufpos == 0) { 1290 if (Nflag) { 1291 shutdown_netin = 1; 1292 shutdown_netout = 1; 1293 } 1294 gone[POLL_NETOUT] = 1; 1295 } 1296 /* net in gone and queue empty? */ 1297 if (gone[POLL_NETIN] && netinbufpos == 0) { 1298 if (Nflag) { 1299 shutdown_netin = 1; 1300 shutdown_netout = 1; 1301 } 1302 gone[POLL_STDOUT] = 1; 1303 } 1304 1305 /* call tls_close if any part of the network socket is closing */ 1306 if ((shutdown_netin || shutdown_netout) && usetls) { 1307 timeout_tls(pfd[POLL_NETIN].fd, tls_ctx, tls_close); 1308 shutdown_netout = shutdown_netin = 1; 1309 } 1310 if (shutdown_netin) { 1311 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1312 gone[POLL_NETIN] = 1; 1313 } 1314 if (shutdown_netout) { 1315 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1316 gone[POLL_NETOUT] = 1; 1317 } 1318 } 1319 } 1320 1321 ssize_t 1322 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1323 { 1324 ssize_t n; 1325 ssize_t adjust; 1326 1327 if (tls) { 1328 n = tls_write(tls, buf, *bufpos); 1329 if (n == -1) 1330 errx(1, "tls write failed (%s)", tls_error(tls)); 1331 } else { 1332 n = write(fd, buf, *bufpos); 1333 /* don't treat EAGAIN, EINTR as error */ 1334 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1335 n = TLS_WANT_POLLOUT; 1336 } 1337 if (n <= 0) 1338 return n; 1339 /* adjust buffer */ 1340 adjust = *bufpos - n; 1341 if (adjust > 0) 1342 memmove(buf, buf + n, adjust); 1343 *bufpos -= n; 1344 return n; 1345 } 1346 1347 ssize_t 1348 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1349 { 1350 size_t num = BUFSIZE - *bufpos; 1351 ssize_t n; 1352 1353 if (tls) { 1354 n = tls_read(tls, buf + *bufpos, num); 1355 if (n == -1) 1356 errx(1, "tls read failed (%s)", tls_error(tls)); 1357 } else { 1358 n = read(fd, buf + *bufpos, num); 1359 /* don't treat EAGAIN, EINTR as error */ 1360 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1361 n = TLS_WANT_POLLIN; 1362 } 1363 if (n <= 0) 1364 return n; 1365 *bufpos += n; 1366 return n; 1367 } 1368 1369 /* 1370 * fdpass() 1371 * Pass the connected file descriptor to stdout and exit. 1372 */ 1373 void 1374 fdpass(int nfd) 1375 { 1376 struct msghdr mh; 1377 union { 1378 struct cmsghdr hdr; 1379 char buf[CMSG_SPACE(sizeof(int))]; 1380 } cmsgbuf; 1381 struct cmsghdr *cmsg; 1382 struct iovec iov; 1383 char c = '\0'; 1384 ssize_t r; 1385 struct pollfd pfd; 1386 1387 /* Avoid obvious stupidity */ 1388 if (isatty(STDOUT_FILENO)) 1389 errx(1, "Cannot pass file descriptor to tty"); 1390 1391 memset(&mh, 0, sizeof(mh)); 1392 memset(&cmsgbuf, 0, sizeof(cmsgbuf)); 1393 memset(&iov, 0, sizeof(iov)); 1394 1395 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1396 mh.msg_controllen = sizeof(cmsgbuf.buf); 1397 cmsg = CMSG_FIRSTHDR(&mh); 1398 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1399 cmsg->cmsg_level = SOL_SOCKET; 1400 cmsg->cmsg_type = SCM_RIGHTS; 1401 *(int *)CMSG_DATA(cmsg) = nfd; 1402 1403 iov.iov_base = &c; 1404 iov.iov_len = 1; 1405 mh.msg_iov = &iov; 1406 mh.msg_iovlen = 1; 1407 1408 memset(&pfd, 0, sizeof(pfd)); 1409 pfd.fd = STDOUT_FILENO; 1410 pfd.events = POLLOUT; 1411 for (;;) { 1412 r = sendmsg(STDOUT_FILENO, &mh, 0); 1413 if (r == -1) { 1414 if (errno == EAGAIN || errno == EINTR) { 1415 if (poll(&pfd, 1, -1) == -1) 1416 err(1, "poll"); 1417 continue; 1418 } 1419 err(1, "sendmsg"); 1420 } else if (r != 1) 1421 errx(1, "sendmsg: unexpected return value %zd", r); 1422 else 1423 break; 1424 } 1425 exit(0); 1426 } 1427 1428 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1429 void 1430 atelnet(int nfd, unsigned char *buf, unsigned int size) 1431 { 1432 unsigned char *p, *end; 1433 unsigned char obuf[4]; 1434 1435 if (size < 3) 1436 return; 1437 end = buf + size - 2; 1438 1439 for (p = buf; p < end; p++) { 1440 if (*p != IAC) 1441 continue; 1442 1443 obuf[0] = IAC; 1444 p++; 1445 if ((*p == WILL) || (*p == WONT)) 1446 obuf[1] = DONT; 1447 else if ((*p == DO) || (*p == DONT)) 1448 obuf[1] = WONT; 1449 else 1450 continue; 1451 1452 p++; 1453 obuf[2] = *p; 1454 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1455 warn("Write Error!"); 1456 } 1457 } 1458 1459 1460 int 1461 strtoport(char *portstr, int udp) 1462 { 1463 struct servent *entry; 1464 const char *errstr; 1465 char *proto; 1466 int port = -1; 1467 1468 proto = udp ? "udp" : "tcp"; 1469 1470 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1471 if (errstr == NULL) 1472 return port; 1473 if (errno != EINVAL) 1474 errx(1, "port number %s: %s", errstr, portstr); 1475 if ((entry = getservbyname(portstr, proto)) == NULL) 1476 errx(1, "service \"%s\" unknown", portstr); 1477 return ntohs(entry->s_port); 1478 } 1479 1480 /* 1481 * build_ports() 1482 * Build an array of ports in portlist[], listing each port 1483 * that we should try to connect to. 1484 */ 1485 void 1486 build_ports(char *p) 1487 { 1488 char *n; 1489 int hi, lo, cp; 1490 int x = 0; 1491 1492 if (isdigit((unsigned char)*p) && (n = strchr(p, '-')) != NULL) { 1493 *n = '\0'; 1494 n++; 1495 1496 /* Make sure the ports are in order: lowest->highest. */ 1497 hi = strtoport(n, uflag); 1498 lo = strtoport(p, uflag); 1499 if (lo > hi) { 1500 cp = hi; 1501 hi = lo; 1502 lo = cp; 1503 } 1504 1505 /* 1506 * Initialize portlist with a random permutation. Based on 1507 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1508 */ 1509 if (rflag) { 1510 for (x = 0; x <= hi - lo; x++) { 1511 cp = arc4random_uniform(x + 1); 1512 portlist[x] = portlist[cp]; 1513 if (asprintf(&portlist[cp], "%d", x + lo) == -1) 1514 err(1, "asprintf"); 1515 } 1516 } else { /* Load ports sequentially. */ 1517 for (cp = lo; cp <= hi; cp++) { 1518 if (asprintf(&portlist[x], "%d", cp) == -1) 1519 err(1, "asprintf"); 1520 x++; 1521 } 1522 } 1523 } else { 1524 char *tmp; 1525 1526 hi = strtoport(p, uflag); 1527 if (asprintf(&tmp, "%d", hi) != -1) 1528 portlist[0] = tmp; 1529 else 1530 err(1, NULL); 1531 } 1532 } 1533 1534 /* 1535 * udptest() 1536 * Do a few writes to see if the UDP port is there. 1537 * Fails once PF state table is full. 1538 */ 1539 int 1540 udptest(int s) 1541 { 1542 int i, ret; 1543 1544 for (i = 0; i <= 3; i++) { 1545 if (write(s, "X", 1) == 1) 1546 ret = 1; 1547 else 1548 ret = -1; 1549 } 1550 return ret; 1551 } 1552 1553 void 1554 set_common_sockopts(int s, int af) 1555 { 1556 int x = 1; 1557 1558 if (Sflag) { 1559 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1560 &x, sizeof(x)) == -1) 1561 err(1, NULL); 1562 } 1563 if (Dflag) { 1564 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1565 &x, sizeof(x)) == -1) 1566 err(1, NULL); 1567 } 1568 if (Tflag != -1) { 1569 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1570 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1571 err(1, "set IP ToS"); 1572 1573 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1574 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1575 err(1, "set IPv6 traffic class"); 1576 } 1577 if (Iflag) { 1578 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1579 &Iflag, sizeof(Iflag)) == -1) 1580 err(1, "set TCP receive buffer size"); 1581 } 1582 if (Oflag) { 1583 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1584 &Oflag, sizeof(Oflag)) == -1) 1585 err(1, "set TCP send buffer size"); 1586 } 1587 1588 if (ttl != -1) { 1589 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1590 IP_TTL, &ttl, sizeof(ttl))) 1591 err(1, "set IP TTL"); 1592 1593 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1594 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1595 err(1, "set IPv6 unicast hops"); 1596 } 1597 1598 if (minttl != -1) { 1599 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1600 IP_MINTTL, &minttl, sizeof(minttl))) 1601 err(1, "set IP min TTL"); 1602 1603 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1604 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1605 err(1, "set IPv6 min hop count"); 1606 } 1607 } 1608 1609 int 1610 process_tos_opt(char *s, int *val) 1611 { 1612 /* DiffServ Codepoints and other TOS mappings */ 1613 const struct toskeywords { 1614 const char *keyword; 1615 int val; 1616 } *t, toskeywords[] = { 1617 { "af11", IPTOS_DSCP_AF11 }, 1618 { "af12", IPTOS_DSCP_AF12 }, 1619 { "af13", IPTOS_DSCP_AF13 }, 1620 { "af21", IPTOS_DSCP_AF21 }, 1621 { "af22", IPTOS_DSCP_AF22 }, 1622 { "af23", IPTOS_DSCP_AF23 }, 1623 { "af31", IPTOS_DSCP_AF31 }, 1624 { "af32", IPTOS_DSCP_AF32 }, 1625 { "af33", IPTOS_DSCP_AF33 }, 1626 { "af41", IPTOS_DSCP_AF41 }, 1627 { "af42", IPTOS_DSCP_AF42 }, 1628 { "af43", IPTOS_DSCP_AF43 }, 1629 { "critical", IPTOS_PREC_CRITIC_ECP }, 1630 { "cs0", IPTOS_DSCP_CS0 }, 1631 { "cs1", IPTOS_DSCP_CS1 }, 1632 { "cs2", IPTOS_DSCP_CS2 }, 1633 { "cs3", IPTOS_DSCP_CS3 }, 1634 { "cs4", IPTOS_DSCP_CS4 }, 1635 { "cs5", IPTOS_DSCP_CS5 }, 1636 { "cs6", IPTOS_DSCP_CS6 }, 1637 { "cs7", IPTOS_DSCP_CS7 }, 1638 { "ef", IPTOS_DSCP_EF }, 1639 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1640 { "lowdelay", IPTOS_LOWDELAY }, 1641 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1642 { "reliability", IPTOS_RELIABILITY }, 1643 { "throughput", IPTOS_THROUGHPUT }, 1644 { NULL, -1 }, 1645 }; 1646 1647 for (t = toskeywords; t->keyword != NULL; t++) { 1648 if (strcmp(s, t->keyword) == 0) { 1649 *val = t->val; 1650 return 1; 1651 } 1652 } 1653 1654 return 0; 1655 } 1656 1657 int 1658 process_tls_opt(char *s, int *flags) 1659 { 1660 size_t len; 1661 char *v; 1662 1663 const struct tlskeywords { 1664 const char *keyword; 1665 int flag; 1666 char **value; 1667 } *t, tlskeywords[] = { 1668 { "ciphers", -1, &tls_ciphers }, 1669 { "clientcert", TLS_CCERT, NULL }, 1670 { "muststaple", TLS_MUSTSTAPLE, NULL }, 1671 { "noverify", TLS_NOVERIFY, NULL }, 1672 { "noname", TLS_NONAME, NULL }, 1673 { "protocols", -1, &tls_protocols }, 1674 { NULL, -1, NULL }, 1675 }; 1676 1677 len = strlen(s); 1678 if ((v = strchr(s, '=')) != NULL) { 1679 len = v - s; 1680 v++; 1681 } 1682 1683 for (t = tlskeywords; t->keyword != NULL; t++) { 1684 if (strlen(t->keyword) == len && 1685 strncmp(s, t->keyword, len) == 0) { 1686 if (t->value != NULL) { 1687 if (v == NULL) 1688 errx(1, "invalid tls value `%s'", s); 1689 *t->value = v; 1690 } else { 1691 *flags |= t->flag; 1692 } 1693 return 1; 1694 } 1695 } 1696 return 0; 1697 } 1698 1699 void 1700 save_peer_cert(struct tls *tls_ctx, FILE *fp) 1701 { 1702 const char *pem; 1703 size_t plen; 1704 1705 if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL) 1706 errx(1, "Can't get peer certificate"); 1707 if (fprintf(fp, "%.*s", (int)plen, pem) < 0) 1708 err(1, "unable to save peer cert"); 1709 if (fflush(fp) != 0) 1710 err(1, "unable to flush peer cert"); 1711 } 1712 1713 void 1714 report_tls(struct tls * tls_ctx, char * host) 1715 { 1716 time_t t; 1717 const char *ocsp_url; 1718 1719 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1720 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1721 fprintf(stderr, "Peer name: %s\n", 1722 tls_expectname ? tls_expectname : host); 1723 if (tls_peer_cert_subject(tls_ctx)) 1724 fprintf(stderr, "Subject: %s\n", 1725 tls_peer_cert_subject(tls_ctx)); 1726 if (tls_peer_cert_issuer(tls_ctx)) 1727 fprintf(stderr, "Issuer: %s\n", 1728 tls_peer_cert_issuer(tls_ctx)); 1729 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1730 fprintf(stderr, "Valid From: %s", ctime(&t)); 1731 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1732 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1733 if (tls_peer_cert_hash(tls_ctx)) 1734 fprintf(stderr, "Cert Hash: %s\n", 1735 tls_peer_cert_hash(tls_ctx)); 1736 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1737 if (ocsp_url != NULL) 1738 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1739 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1740 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1741 fprintf(stderr, "OCSP Stapling: %s\n", 1742 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1743 tls_peer_ocsp_result(tls_ctx)); 1744 fprintf(stderr, 1745 " response_status=%d cert_status=%d crl_reason=%d\n", 1746 tls_peer_ocsp_response_status(tls_ctx), 1747 tls_peer_ocsp_cert_status(tls_ctx), 1748 tls_peer_ocsp_crl_reason(tls_ctx)); 1749 t = tls_peer_ocsp_this_update(tls_ctx); 1750 fprintf(stderr, " this update: %s", 1751 t != -1 ? ctime(&t) : "\n"); 1752 t = tls_peer_ocsp_next_update(tls_ctx); 1753 fprintf(stderr, " next update: %s", 1754 t != -1 ? ctime(&t) : "\n"); 1755 t = tls_peer_ocsp_revocation_time(tls_ctx); 1756 fprintf(stderr, " revocation: %s", 1757 t != -1 ? ctime(&t) : "\n"); 1758 break; 1759 case -1: 1760 break; 1761 default: 1762 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1763 tls_peer_ocsp_response_status(tls_ctx), 1764 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1765 tls_peer_ocsp_result(tls_ctx)); 1766 break; 1767 1768 } 1769 } 1770 1771 void 1772 report_sock(const char *msg, const struct sockaddr *sa, socklen_t salen, 1773 char *path) 1774 { 1775 char host[NI_MAXHOST], port[NI_MAXSERV]; 1776 int herr; 1777 int flags = NI_NUMERICSERV; 1778 1779 if (path != NULL) { 1780 fprintf(stderr, "%s on %s\n", msg, path); 1781 return; 1782 } 1783 1784 if (nflag) 1785 flags |= NI_NUMERICHOST; 1786 1787 if ((herr = getnameinfo(sa, salen, host, sizeof(host), 1788 port, sizeof(port), flags)) != 0) { 1789 if (herr == EAI_SYSTEM) 1790 err(1, "getnameinfo"); 1791 else 1792 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1793 } 1794 1795 fprintf(stderr, "%s on %s %s\n", msg, host, port); 1796 } 1797 1798 void 1799 help(void) 1800 { 1801 usage(0); 1802 fprintf(stderr, "\tCommand Summary:\n\ 1803 \t-4 Use IPv4\n\ 1804 \t-6 Use IPv6\n\ 1805 \t-C certfile Public key file\n\ 1806 \t-c Use TLS\n\ 1807 \t-D Enable the debug socket option\n\ 1808 \t-d Detach from stdin\n\ 1809 \t-e name\t Required name in peer certificate\n\ 1810 \t-F Pass socket fd\n\ 1811 \t-H hash\t Hash string of peer certificate\n\ 1812 \t-h This help text\n\ 1813 \t-I length TCP receive buffer length\n\ 1814 \t-i interval Delay interval for lines sent, ports scanned\n\ 1815 \t-K keyfile Private key file\n\ 1816 \t-k Keep inbound sockets open for multiple connects\n\ 1817 \t-l Listen mode, for inbound connects\n\ 1818 \t-M ttl Outgoing TTL / Hop Limit\n\ 1819 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1820 \t-N Shutdown the network socket after EOF on stdin\n\ 1821 \t-n Suppress name/port resolutions\n\ 1822 \t-O length TCP send buffer length\n\ 1823 \t-o staplefile Staple file\n\ 1824 \t-P proxyuser\tUsername for proxy authentication\n\ 1825 \t-p port\t Specify local port for remote connects\n\ 1826 \t-R CAfile CA bundle\n\ 1827 \t-r Randomize remote ports\n\ 1828 \t-S Enable the TCP MD5 signature option\n\ 1829 \t-s source Local source address\n\ 1830 \t-T keyword TOS value or TLS options\n\ 1831 \t-t Answer TELNET negotiation\n\ 1832 \t-U Use UNIX domain socket\n\ 1833 \t-u UDP mode\n\ 1834 \t-V rtable Specify alternate routing table\n\ 1835 \t-v Verbose\n\ 1836 \t-W recvlimit Terminate after receiving a number of packets\n\ 1837 \t-w timeout Timeout for connects and final net reads\n\ 1838 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1839 \t-x addr[:port]\tSpecify proxy address and port\n\ 1840 \t-Z Peer certificate file\n\ 1841 \t-z Zero-I/O mode [used for scanning]\n\ 1842 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1843 exit(1); 1844 } 1845 1846 void 1847 usage(int ret) 1848 { 1849 fprintf(stderr, 1850 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1851 "[-H hash] [-I length]\n" 1852 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1853 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1854 "[-R CAfile]\n" 1855 "\t [-s source] [-T keyword] [-V rtable] [-W recvlimit] " 1856 "[-w timeout]\n" 1857 "\t [-X proxy_protocol] [-x proxy_address[:port]] " 1858 "[-Z peercertfile]\n" 1859 "\t [destination] [port]\n"); 1860 if (ret) 1861 exit(1); 1862 } 1863