1 /* $OpenBSD: netcat.c,v 1.188 2017/10/24 17:49:35 bluhm Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org> 4 * Copyright (c) 2015 Bob Beck. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * Re-written nc(1) for OpenBSD. Original implementation by 32 * *Hobbit* <hobbit@avian.org>. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 40 #include <netinet/in.h> 41 #include <netinet/tcp.h> 42 #include <netinet/ip.h> 43 #include <arpa/telnet.h> 44 45 #include <err.h> 46 #include <errno.h> 47 #include <limits.h> 48 #include <netdb.h> 49 #include <poll.h> 50 #include <signal.h> 51 #include <stdarg.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <time.h> 56 #include <tls.h> 57 #include <unistd.h> 58 59 #include "atomicio.h" 60 61 #define PORT_MAX 65535 62 #define UNIX_DG_TMP_SOCKET_SIZE 19 63 64 #define POLL_STDIN 0 65 #define POLL_NETOUT 1 66 #define POLL_NETIN 2 67 #define POLL_STDOUT 3 68 #define BUFSIZE 16384 69 #define DEFAULT_CA_FILE "/etc/ssl/cert.pem" 70 71 #define TLS_ALL (1 << 1) 72 #define TLS_NOVERIFY (1 << 2) 73 #define TLS_NONAME (1 << 3) 74 #define TLS_CCERT (1 << 4) 75 #define TLS_MUSTSTAPLE (1 << 5) 76 #define TLS_COMPAT (1 << 6) 77 78 /* Command Line Options */ 79 int dflag; /* detached, no stdin */ 80 int Fflag; /* fdpass sock to stdout */ 81 unsigned int iflag; /* Interval Flag */ 82 int kflag; /* More than one connect */ 83 int lflag; /* Bind to local port */ 84 int Nflag; /* shutdown() network socket */ 85 int nflag; /* Don't do name look up */ 86 char *Pflag; /* Proxy username */ 87 char *pflag; /* Localport flag */ 88 int rflag; /* Random ports flag */ 89 char *sflag; /* Source Address */ 90 int tflag; /* Telnet Emulation */ 91 int uflag; /* UDP - Default to TCP */ 92 int vflag; /* Verbosity */ 93 int xflag; /* Socks proxy */ 94 int zflag; /* Port Scan Flag */ 95 int Dflag; /* sodebug */ 96 int Iflag; /* TCP receive buffer size */ 97 int Oflag; /* TCP send buffer size */ 98 int Sflag; /* TCP MD5 signature option */ 99 int Tflag = -1; /* IP Type of Service */ 100 int rtableid = -1; 101 102 int usetls; /* use TLS */ 103 char *Cflag; /* Public cert file */ 104 char *Kflag; /* Private key file */ 105 char *oflag; /* OCSP stapling file */ 106 char *Rflag = DEFAULT_CA_FILE; /* Root CA file */ 107 int tls_cachanged; /* Using non-default CA file */ 108 int TLSopt; /* TLS options */ 109 char *tls_expectname; /* required name in peer cert */ 110 char *tls_expecthash; /* required hash of peer cert */ 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(char *, 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); 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 map_tos(char *, int *); 139 int map_tls(char *, int *); 140 void save_peer_cert(struct tls *_tls_ctx, FILE *_fp); 141 void report_connect(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 struct addrinfo hints; 155 struct servent *sv; 156 socklen_t len; 157 struct sockaddr_storage cliaddr; 158 char *proxy = NULL, *proxyport = NULL; 159 const char *errstr; 160 struct addrinfo proxyhints; 161 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 162 struct tls_config *tls_cfg = NULL; 163 struct tls *tls_ctx = NULL; 164 165 ret = 1; 166 socksv = 5; 167 host = NULL; 168 uport = NULL; 169 sv = NULL; 170 171 signal(SIGPIPE, SIG_IGN); 172 173 while ((ch = getopt(argc, argv, 174 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z")) 175 != -1) { 176 switch (ch) { 177 case '4': 178 family = AF_INET; 179 break; 180 case '6': 181 family = AF_INET6; 182 break; 183 case 'U': 184 family = AF_UNIX; 185 break; 186 case 'X': 187 if (strcasecmp(optarg, "connect") == 0) 188 socksv = -1; /* HTTP proxy CONNECT */ 189 else if (strcmp(optarg, "4") == 0) 190 socksv = 4; /* SOCKS v.4 */ 191 else if (strcmp(optarg, "5") == 0) 192 socksv = 5; /* SOCKS v.5 */ 193 else 194 errx(1, "unsupported proxy protocol"); 195 break; 196 case 'C': 197 Cflag = optarg; 198 break; 199 case 'c': 200 usetls = 1; 201 break; 202 case 'd': 203 dflag = 1; 204 break; 205 case 'e': 206 tls_expectname = optarg; 207 break; 208 case 'F': 209 Fflag = 1; 210 break; 211 case 'H': 212 tls_expecthash = optarg; 213 break; 214 case 'h': 215 help(); 216 break; 217 case 'i': 218 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 219 if (errstr) 220 errx(1, "interval %s: %s", errstr, optarg); 221 break; 222 case 'K': 223 Kflag = optarg; 224 break; 225 case 'k': 226 kflag = 1; 227 break; 228 case 'l': 229 lflag = 1; 230 break; 231 case 'M': 232 ttl = strtonum(optarg, 0, 255, &errstr); 233 if (errstr) 234 errx(1, "ttl is %s", errstr); 235 break; 236 case 'm': 237 minttl = strtonum(optarg, 0, 255, &errstr); 238 if (errstr) 239 errx(1, "minttl is %s", errstr); 240 break; 241 case 'N': 242 Nflag = 1; 243 break; 244 case 'n': 245 nflag = 1; 246 break; 247 case 'P': 248 Pflag = optarg; 249 break; 250 case 'p': 251 pflag = optarg; 252 break; 253 case 'R': 254 tls_cachanged = 1; 255 Rflag = optarg; 256 break; 257 case 'r': 258 rflag = 1; 259 break; 260 case 's': 261 sflag = optarg; 262 break; 263 case 't': 264 tflag = 1; 265 break; 266 case 'u': 267 uflag = 1; 268 break; 269 case 'V': 270 rtableid = (int)strtonum(optarg, 0, 271 RT_TABLEID_MAX, &errstr); 272 if (errstr) 273 errx(1, "rtable %s: %s", errstr, optarg); 274 break; 275 case 'v': 276 vflag = 1; 277 break; 278 case 'W': 279 recvlimit = strtonum(optarg, 1, INT_MAX, &errstr); 280 if (errstr) 281 errx(1, "receive limit %s: %s", errstr, optarg); 282 break; 283 case 'w': 284 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 285 if (errstr) 286 errx(1, "timeout %s: %s", errstr, optarg); 287 timeout *= 1000; 288 break; 289 case 'x': 290 xflag = 1; 291 if ((proxy = strdup(optarg)) == NULL) 292 err(1, NULL); 293 break; 294 case 'Z': 295 if (strcmp(optarg, "-") == 0) 296 Zflag = stderr; 297 else if ((Zflag = fopen(optarg, "w")) == NULL) 298 err(1, "can't open %s", optarg); 299 break; 300 case 'z': 301 zflag = 1; 302 break; 303 case 'D': 304 Dflag = 1; 305 break; 306 case 'I': 307 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 308 if (errstr != NULL) 309 errx(1, "TCP receive window %s: %s", 310 errstr, optarg); 311 break; 312 case 'O': 313 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 314 if (errstr != NULL) 315 errx(1, "TCP send window %s: %s", 316 errstr, optarg); 317 break; 318 case 'o': 319 oflag = optarg; 320 break; 321 case 'S': 322 Sflag = 1; 323 break; 324 case 'T': 325 errstr = NULL; 326 errno = 0; 327 if (map_tos(optarg, &Tflag)) 328 break; 329 if (map_tls(optarg, &TLSopt)) 330 break; 331 if (strlen(optarg) > 1 && optarg[0] == '0' && 332 optarg[1] == 'x') 333 Tflag = (int)strtol(optarg, NULL, 16); 334 else 335 Tflag = (int)strtonum(optarg, 0, 255, 336 &errstr); 337 if (Tflag < 0 || Tflag > 255 || errstr || errno) 338 errx(1, "illegal tos/tls value %s", optarg); 339 break; 340 default: 341 usage(1); 342 } 343 } 344 argc -= optind; 345 argv += optind; 346 347 if (rtableid >= 0) 348 if (setrtable(rtableid) == -1) 349 err(1, "setrtable"); 350 351 if (family == AF_UNIX) { 352 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 353 err(1, "pledge"); 354 } else if (Fflag && Pflag) { 355 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 356 err(1, "pledge"); 357 } else if (Fflag) { 358 if (pledge("stdio inet dns sendfd", NULL) == -1) 359 err(1, "pledge"); 360 } else if (Pflag && usetls) { 361 if (pledge("stdio rpath inet dns tty", NULL) == -1) 362 err(1, "pledge"); 363 } else if (Pflag) { 364 if (pledge("stdio inet dns tty", NULL) == -1) 365 err(1, "pledge"); 366 } else if (usetls) { 367 if (pledge("stdio rpath inet dns", NULL) == -1) 368 err(1, "pledge"); 369 } else if (pledge("stdio inet dns", NULL) == -1) 370 err(1, "pledge"); 371 372 /* Cruft to make sure options are clean, and used properly. */ 373 if (argv[0] && !argv[1] && family == AF_UNIX) { 374 host = argv[0]; 375 uport = NULL; 376 } else if (argv[0] && !argv[1]) { 377 if (!lflag) 378 usage(1); 379 uport = argv[0]; 380 host = NULL; 381 } else if (argv[0] && argv[1]) { 382 host = argv[0]; 383 uport = argv[1]; 384 } else 385 usage(1); 386 387 if (lflag && sflag) 388 errx(1, "cannot use -s and -l"); 389 if (lflag && pflag) 390 errx(1, "cannot use -p and -l"); 391 if (lflag && zflag) 392 errx(1, "cannot use -z and -l"); 393 if (!lflag && kflag) 394 errx(1, "must use -l with -k"); 395 if (uflag && usetls) 396 errx(1, "cannot use -c and -u"); 397 if ((family == AF_UNIX) && usetls) 398 errx(1, "cannot use -c and -U"); 399 if ((family == AF_UNIX) && Fflag) 400 errx(1, "cannot use -F and -U"); 401 if (Fflag && usetls) 402 errx(1, "cannot use -c and -F"); 403 if (TLSopt && !usetls) 404 errx(1, "you must specify -c to use TLS options"); 405 if ((TLSopt & (TLS_ALL|TLS_COMPAT)) == (TLS_ALL|TLS_COMPAT)) 406 errx(1, "cannot use -T tlsall and -T tlscompat"); 407 if (Cflag && !usetls) 408 errx(1, "you must specify -c to use -C"); 409 if (Kflag && !usetls) 410 errx(1, "you must specify -c to use -K"); 411 if (Zflag && !usetls) 412 errx(1, "you must specify -c to use -Z"); 413 if (oflag && !Cflag) 414 errx(1, "you must specify -C to use -o"); 415 if (tls_cachanged && !usetls) 416 errx(1, "you must specify -c to use -R"); 417 if (tls_expecthash && !usetls) 418 errx(1, "you must specify -c to use -H"); 419 if (tls_expectname && !usetls) 420 errx(1, "you must specify -c to use -e"); 421 422 /* Get name of temporary socket for unix datagram client */ 423 if ((family == AF_UNIX) && uflag && !lflag) { 424 if (sflag) { 425 unix_dg_tmp_socket = sflag; 426 } else { 427 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 428 UNIX_DG_TMP_SOCKET_SIZE); 429 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 430 err(1, "mktemp"); 431 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 432 } 433 } 434 435 /* Initialize addrinfo structure. */ 436 if (family != AF_UNIX) { 437 memset(&hints, 0, sizeof(struct addrinfo)); 438 hints.ai_family = family; 439 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 440 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 441 if (nflag) 442 hints.ai_flags |= AI_NUMERICHOST; 443 } 444 445 if (xflag) { 446 if (uflag) 447 errx(1, "no proxy support for UDP mode"); 448 449 if (lflag) 450 errx(1, "no proxy support for listen"); 451 452 if (family == AF_UNIX) 453 errx(1, "no proxy support for unix sockets"); 454 455 if (sflag) 456 errx(1, "no proxy support for local source address"); 457 458 if (*proxy == '[') { 459 ++proxy; 460 proxyport = strchr(proxy, ']'); 461 if (proxyport == NULL) 462 errx(1, "missing closing bracket in proxy"); 463 *proxyport++ = '\0'; 464 if (*proxyport == '\0') 465 /* Use default proxy port. */ 466 proxyport = NULL; 467 else { 468 if (*proxyport == ':') 469 ++proxyport; 470 else 471 errx(1, "garbage proxy port delimiter"); 472 } 473 } else { 474 proxyport = strrchr(proxy, ':'); 475 if (proxyport != NULL) 476 *proxyport++ = '\0'; 477 } 478 479 memset(&proxyhints, 0, sizeof(struct addrinfo)); 480 proxyhints.ai_family = family; 481 proxyhints.ai_socktype = SOCK_STREAM; 482 proxyhints.ai_protocol = IPPROTO_TCP; 483 if (nflag) 484 proxyhints.ai_flags |= AI_NUMERICHOST; 485 } 486 487 if (usetls) { 488 if (tls_init() == -1) 489 errx(1, "unable to initialize TLS"); 490 if ((tls_cfg = tls_config_new()) == NULL) 491 errx(1, "unable to allocate TLS config"); 492 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 493 errx(1, "%s", tls_config_error(tls_cfg)); 494 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 495 errx(1, "%s", tls_config_error(tls_cfg)); 496 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 497 errx(1, "%s", tls_config_error(tls_cfg)); 498 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 499 errx(1, "%s", tls_config_error(tls_cfg)); 500 if (TLSopt & (TLS_ALL|TLS_COMPAT)) { 501 if (tls_config_set_protocols(tls_cfg, 502 TLS_PROTOCOLS_ALL) != 0) 503 errx(1, "%s", tls_config_error(tls_cfg)); 504 if (tls_config_set_ciphers(tls_cfg, 505 (TLSopt & TLS_ALL) ? "all" : "compat") != 0) 506 errx(1, "%s", tls_config_error(tls_cfg)); 507 } 508 if (!lflag && (TLSopt & TLS_CCERT)) 509 errx(1, "clientcert is only valid with -l"); 510 if (TLSopt & TLS_NONAME) 511 tls_config_insecure_noverifyname(tls_cfg); 512 if (TLSopt & TLS_NOVERIFY) { 513 if (tls_expecthash != NULL) 514 errx(1, "-H and -T noverify may not be used " 515 "together"); 516 tls_config_insecure_noverifycert(tls_cfg); 517 } 518 if (TLSopt & TLS_MUSTSTAPLE) 519 tls_config_ocsp_require_stapling(tls_cfg); 520 521 if (Pflag) { 522 if (pledge("stdio inet dns tty", NULL) == -1) 523 err(1, "pledge"); 524 } else if (pledge("stdio inet dns", NULL) == -1) 525 err(1, "pledge"); 526 } 527 if (lflag) { 528 struct tls *tls_cctx = NULL; 529 int connfd; 530 ret = 0; 531 532 if (family == AF_UNIX) { 533 if (uflag) 534 s = unix_bind(host, 0); 535 else 536 s = unix_listen(host); 537 } 538 539 if (usetls) { 540 tls_config_verify_client_optional(tls_cfg); 541 if ((tls_ctx = tls_server()) == NULL) 542 errx(1, "tls server creation failed"); 543 if (tls_configure(tls_ctx, tls_cfg) == -1) 544 errx(1, "tls configuration failed (%s)", 545 tls_error(tls_ctx)); 546 } 547 /* Allow only one connection at a time, but stay alive. */ 548 for (;;) { 549 if (family != AF_UNIX) 550 s = local_listen(host, uport, hints); 551 if (s < 0) 552 err(1, NULL); 553 if (uflag && kflag) { 554 /* 555 * For UDP and -k, don't connect the socket, 556 * let it receive datagrams from multiple 557 * socket pairs. 558 */ 559 readwrite(s, NULL); 560 } else if (uflag && !kflag) { 561 /* 562 * For UDP and not -k, we will use recvfrom() 563 * initially to wait for a caller, then use 564 * the regular functions to talk to the caller. 565 */ 566 int rv; 567 char buf[2048]; 568 struct sockaddr_storage z; 569 570 len = sizeof(z); 571 rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK, 572 (struct sockaddr *)&z, &len); 573 if (rv < 0) 574 err(1, "recvfrom"); 575 576 rv = connect(s, (struct sockaddr *)&z, len); 577 if (rv < 0) 578 err(1, "connect"); 579 580 if (vflag) 581 report_connect((struct sockaddr *)&z, len, NULL); 582 583 readwrite(s, NULL); 584 } else { 585 len = sizeof(cliaddr); 586 connfd = accept4(s, (struct sockaddr *)&cliaddr, 587 &len, SOCK_NONBLOCK); 588 if (connfd == -1) { 589 /* For now, all errnos are fatal */ 590 err(1, "accept"); 591 } 592 if (vflag) 593 report_connect((struct sockaddr *)&cliaddr, len, 594 family == AF_UNIX ? host : NULL); 595 if ((usetls) && 596 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 597 readwrite(connfd, tls_cctx); 598 if (!usetls) 599 readwrite(connfd, NULL); 600 if (tls_cctx) { 601 timeout_tls(s, tls_cctx, tls_close); 602 tls_free(tls_cctx); 603 tls_cctx = NULL; 604 } 605 close(connfd); 606 } 607 if (family != AF_UNIX) 608 close(s); 609 else if (uflag) { 610 if (connect(s, NULL, 0) < 0) 611 err(1, "connect"); 612 } 613 614 if (!kflag) 615 break; 616 } 617 } else if (family == AF_UNIX) { 618 ret = 0; 619 620 if ((s = unix_connect(host)) > 0) { 621 if (!zflag) 622 readwrite(s, NULL); 623 close(s); 624 } else 625 ret = 1; 626 627 if (uflag) 628 unlink(unix_dg_tmp_socket); 629 return ret; 630 631 } else { 632 int i = 0; 633 634 /* Construct the portlist[] array. */ 635 build_ports(uport); 636 637 /* Cycle through portlist, connecting to each port. */ 638 for (s = -1, i = 0; portlist[i] != NULL; i++) { 639 if (s != -1) 640 close(s); 641 642 if (usetls) { 643 if ((tls_ctx = tls_client()) == NULL) 644 errx(1, "tls client creation failed"); 645 if (tls_configure(tls_ctx, tls_cfg) == -1) 646 errx(1, "tls configuration failed (%s)", 647 tls_error(tls_ctx)); 648 } 649 if (xflag) 650 s = socks_connect(host, portlist[i], hints, 651 proxy, proxyport, proxyhints, socksv, 652 Pflag); 653 else 654 s = remote_connect(host, portlist[i], hints); 655 656 if (s == -1) 657 continue; 658 659 ret = 0; 660 if (vflag || zflag) { 661 /* For UDP, make sure we are connected. */ 662 if (uflag) { 663 if (udptest(s) == -1) { 664 ret = 1; 665 continue; 666 } 667 } 668 669 /* Don't look up port if -n. */ 670 if (nflag) 671 sv = NULL; 672 else { 673 sv = getservbyport( 674 ntohs(atoi(portlist[i])), 675 uflag ? "udp" : "tcp"); 676 } 677 678 fprintf(stderr, 679 "Connection to %s %s port [%s/%s] " 680 "succeeded!\n", host, portlist[i], 681 uflag ? "udp" : "tcp", 682 sv ? sv->s_name : "*"); 683 } 684 if (Fflag) 685 fdpass(s); 686 else { 687 if (usetls) 688 tls_setup_client(tls_ctx, s, host); 689 if (!zflag) 690 readwrite(s, tls_ctx); 691 if (tls_ctx) { 692 timeout_tls(s, tls_ctx, tls_close); 693 tls_free(tls_ctx); 694 tls_ctx = NULL; 695 } 696 } 697 } 698 } 699 700 if (s != -1) 701 close(s); 702 703 tls_config_free(tls_cfg); 704 705 return ret; 706 } 707 708 /* 709 * unix_bind() 710 * Returns a unix socket bound to the given path 711 */ 712 int 713 unix_bind(char *path, int flags) 714 { 715 struct sockaddr_un s_un; 716 int s, save_errno; 717 718 /* Create unix domain socket. */ 719 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 720 0)) < 0) 721 return -1; 722 723 memset(&s_un, 0, sizeof(struct sockaddr_un)); 724 s_un.sun_family = AF_UNIX; 725 726 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 727 sizeof(s_un.sun_path)) { 728 close(s); 729 errno = ENAMETOOLONG; 730 return -1; 731 } 732 733 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 734 save_errno = errno; 735 close(s); 736 errno = save_errno; 737 return -1; 738 } 739 740 return s; 741 } 742 743 int 744 timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) 745 { 746 struct pollfd pfd; 747 int ret; 748 749 while ((ret = (*func)(tls_ctx)) != 0) { 750 if (ret == TLS_WANT_POLLIN) 751 pfd.events = POLLIN; 752 else if (ret == TLS_WANT_POLLOUT) 753 pfd.events = POLLOUT; 754 else 755 break; 756 pfd.fd = s; 757 if ((ret = poll(&pfd, 1, timeout)) == 1) 758 continue; 759 else if (ret == 0) { 760 errno = ETIMEDOUT; 761 ret = -1; 762 break; 763 } else 764 err(1, "poll failed"); 765 } 766 767 return ret; 768 } 769 770 void 771 tls_setup_client(struct tls *tls_ctx, int s, char *host) 772 { 773 const char *errstr; 774 775 if (tls_connect_socket(tls_ctx, s, 776 tls_expectname ? tls_expectname : host) == -1) { 777 errx(1, "tls connection failed (%s)", 778 tls_error(tls_ctx)); 779 } 780 if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { 781 if ((errstr = tls_error(tls_ctx)) == NULL) 782 errstr = strerror(errno); 783 errx(1, "tls handshake failed (%s)", errstr); 784 } 785 if (vflag) 786 report_tls(tls_ctx, host); 787 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 788 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 789 errx(1, "peer certificate is not %s", tls_expecthash); 790 if (Zflag) { 791 save_peer_cert(tls_ctx, Zflag); 792 if (Zflag != stderr && (fclose(Zflag) != 0)) 793 err(1, "fclose failed saving peer cert"); 794 } 795 } 796 797 struct tls * 798 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 799 { 800 struct tls *tls_cctx; 801 const char *errstr; 802 803 if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { 804 warnx("tls accept failed (%s)", tls_error(tls_ctx)); 805 } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { 806 if ((errstr = tls_error(tls_cctx)) == NULL) 807 errstr = strerror(errno); 808 warnx("tls handshake failed (%s)", errstr); 809 } else { 810 int gotcert = tls_peer_cert_provided(tls_cctx); 811 812 if (vflag && gotcert) 813 report_tls(tls_cctx, host); 814 if ((TLSopt & TLS_CCERT) && !gotcert) 815 warnx("No client certificate provided"); 816 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 817 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 818 warnx("peer certificate is not %s", tls_expecthash); 819 else if (gotcert && tls_expectname && 820 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 821 warnx("name (%s) not found in client cert", 822 tls_expectname); 823 else { 824 return tls_cctx; 825 } 826 } 827 return NULL; 828 } 829 830 /* 831 * unix_connect() 832 * Returns a socket connected to a local unix socket. Returns -1 on failure. 833 */ 834 int 835 unix_connect(char *path) 836 { 837 struct sockaddr_un s_un; 838 int s, save_errno; 839 840 if (uflag) { 841 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 842 return -1; 843 } else { 844 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 845 return -1; 846 } 847 848 memset(&s_un, 0, sizeof(struct sockaddr_un)); 849 s_un.sun_family = AF_UNIX; 850 851 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 852 sizeof(s_un.sun_path)) { 853 close(s); 854 errno = ENAMETOOLONG; 855 return -1; 856 } 857 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 858 save_errno = errno; 859 close(s); 860 errno = save_errno; 861 return -1; 862 } 863 return s; 864 865 } 866 867 /* 868 * unix_listen() 869 * Create a unix domain socket, and listen on it. 870 */ 871 int 872 unix_listen(char *path) 873 { 874 int s; 875 if ((s = unix_bind(path, 0)) < 0) 876 return -1; 877 878 if (listen(s, 5) < 0) { 879 close(s); 880 return -1; 881 } 882 return s; 883 } 884 885 /* 886 * remote_connect() 887 * Returns a socket connected to a remote host. Properly binds to a local 888 * port or source address if needed. Returns -1 on failure. 889 */ 890 int 891 remote_connect(const char *host, const char *port, struct addrinfo hints) 892 { 893 struct addrinfo *res, *res0; 894 int s = -1, error, on = 1, save_errno; 895 896 if ((error = getaddrinfo(host, port, &hints, &res0))) 897 errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, 898 port, gai_strerror(error)); 899 900 for (res = res0; res; res = res->ai_next) { 901 if ((s = socket(res->ai_family, res->ai_socktype | 902 SOCK_NONBLOCK, res->ai_protocol)) < 0) 903 continue; 904 905 /* Bind to a local port or source address if specified. */ 906 if (sflag || pflag) { 907 struct addrinfo ahints, *ares; 908 909 /* try SO_BINDANY, but don't insist */ 910 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 911 memset(&ahints, 0, sizeof(struct addrinfo)); 912 ahints.ai_family = res->ai_family; 913 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 914 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 915 ahints.ai_flags = AI_PASSIVE; 916 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 917 errx(1, "getaddrinfo: %s", gai_strerror(error)); 918 919 if (bind(s, (struct sockaddr *)ares->ai_addr, 920 ares->ai_addrlen) < 0) 921 err(1, "bind failed"); 922 freeaddrinfo(ares); 923 } 924 925 set_common_sockopts(s, res->ai_family); 926 927 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 928 break; 929 if (vflag) 930 warn("connect to %s port %s (%s) failed", host, port, 931 uflag ? "udp" : "tcp"); 932 933 save_errno = errno; 934 close(s); 935 errno = save_errno; 936 s = -1; 937 } 938 939 freeaddrinfo(res0); 940 941 return s; 942 } 943 944 int 945 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 946 { 947 struct pollfd pfd; 948 socklen_t optlen; 949 int optval; 950 int ret; 951 952 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 953 pfd.fd = s; 954 pfd.events = POLLOUT; 955 if ((ret = poll(&pfd, 1, timeout)) == 1) { 956 optlen = sizeof(optval); 957 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 958 &optval, &optlen)) == 0) { 959 errno = optval; 960 ret = optval == 0 ? 0 : -1; 961 } 962 } else if (ret == 0) { 963 errno = ETIMEDOUT; 964 ret = -1; 965 } else 966 err(1, "poll failed"); 967 } 968 969 return ret; 970 } 971 972 /* 973 * local_listen() 974 * Returns a socket listening on a local port, binds to specified source 975 * address. Returns -1 on failure. 976 */ 977 int 978 local_listen(char *host, char *port, struct addrinfo hints) 979 { 980 struct addrinfo *res, *res0; 981 int s = -1, ret, x = 1, save_errno; 982 int error; 983 984 /* Allow nodename to be null. */ 985 hints.ai_flags |= AI_PASSIVE; 986 987 /* 988 * In the case of binding to a wildcard address 989 * default to binding to an ipv4 address. 990 */ 991 if (host == NULL && hints.ai_family == AF_UNSPEC) 992 hints.ai_family = AF_INET; 993 994 if ((error = getaddrinfo(host, port, &hints, &res0))) 995 errx(1, "getaddrinfo: %s", gai_strerror(error)); 996 997 for (res = res0; res; res = res->ai_next) { 998 if ((s = socket(res->ai_family, res->ai_socktype, 999 res->ai_protocol)) < 0) 1000 continue; 1001 1002 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 1003 if (ret == -1) 1004 err(1, NULL); 1005 1006 set_common_sockopts(s, res->ai_family); 1007 1008 if (bind(s, (struct sockaddr *)res->ai_addr, 1009 res->ai_addrlen) == 0) 1010 break; 1011 1012 save_errno = errno; 1013 close(s); 1014 errno = save_errno; 1015 s = -1; 1016 } 1017 1018 if (!uflag && s != -1) { 1019 if (listen(s, 1) < 0) 1020 err(1, "listen"); 1021 } 1022 1023 freeaddrinfo(res0); 1024 1025 return s; 1026 } 1027 1028 /* 1029 * readwrite() 1030 * Loop that polls on the network file descriptor and stdin. 1031 */ 1032 void 1033 readwrite(int net_fd, struct tls *tls_ctx) 1034 { 1035 struct pollfd pfd[4]; 1036 int stdin_fd = STDIN_FILENO; 1037 int stdout_fd = STDOUT_FILENO; 1038 unsigned char netinbuf[BUFSIZE]; 1039 size_t netinbufpos = 0; 1040 unsigned char stdinbuf[BUFSIZE]; 1041 size_t stdinbufpos = 0; 1042 int n, num_fds; 1043 ssize_t ret; 1044 1045 /* don't read from stdin if requested */ 1046 if (dflag) 1047 stdin_fd = -1; 1048 1049 /* stdin */ 1050 pfd[POLL_STDIN].fd = stdin_fd; 1051 pfd[POLL_STDIN].events = POLLIN; 1052 1053 /* network out */ 1054 pfd[POLL_NETOUT].fd = net_fd; 1055 pfd[POLL_NETOUT].events = 0; 1056 1057 /* network in */ 1058 pfd[POLL_NETIN].fd = net_fd; 1059 pfd[POLL_NETIN].events = POLLIN; 1060 1061 /* stdout */ 1062 pfd[POLL_STDOUT].fd = stdout_fd; 1063 pfd[POLL_STDOUT].events = 0; 1064 1065 while (1) { 1066 /* both inputs are gone, buffers are empty, we are done */ 1067 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1068 stdinbufpos == 0 && netinbufpos == 0) 1069 return; 1070 /* both outputs are gone, we can't continue */ 1071 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) 1072 return; 1073 /* listen and net in gone, queues empty, done */ 1074 if (lflag && pfd[POLL_NETIN].fd == -1 && 1075 stdinbufpos == 0 && netinbufpos == 0) 1076 return; 1077 1078 /* help says -i is for "wait between lines sent". We read and 1079 * write arbitrary amounts of data, and we don't want to start 1080 * scanning for newlines, so this is as good as it gets */ 1081 if (iflag) 1082 sleep(iflag); 1083 1084 /* poll */ 1085 num_fds = poll(pfd, 4, timeout); 1086 1087 /* treat poll errors */ 1088 if (num_fds == -1) 1089 err(1, "polling error"); 1090 1091 /* timeout happened */ 1092 if (num_fds == 0) 1093 return; 1094 1095 /* treat socket error conditions */ 1096 for (n = 0; n < 4; n++) { 1097 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1098 pfd[n].fd = -1; 1099 } 1100 } 1101 /* reading is possible after HUP */ 1102 if (pfd[POLL_STDIN].events & POLLIN && 1103 pfd[POLL_STDIN].revents & POLLHUP && 1104 !(pfd[POLL_STDIN].revents & POLLIN)) 1105 pfd[POLL_STDIN].fd = -1; 1106 1107 if (pfd[POLL_NETIN].events & POLLIN && 1108 pfd[POLL_NETIN].revents & POLLHUP && 1109 !(pfd[POLL_NETIN].revents & POLLIN)) 1110 pfd[POLL_NETIN].fd = -1; 1111 1112 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1113 if (Nflag) 1114 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1115 pfd[POLL_NETOUT].fd = -1; 1116 } 1117 /* if HUP, stop watching stdout */ 1118 if (pfd[POLL_STDOUT].revents & POLLHUP) 1119 pfd[POLL_STDOUT].fd = -1; 1120 /* if no net out, stop watching stdin */ 1121 if (pfd[POLL_NETOUT].fd == -1) 1122 pfd[POLL_STDIN].fd = -1; 1123 /* if no stdout, stop watching net in */ 1124 if (pfd[POLL_STDOUT].fd == -1) { 1125 if (pfd[POLL_NETIN].fd != -1) 1126 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1127 pfd[POLL_NETIN].fd = -1; 1128 } 1129 1130 /* try to read from stdin */ 1131 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1132 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1133 &stdinbufpos, NULL); 1134 if (ret == TLS_WANT_POLLIN) 1135 pfd[POLL_STDIN].events = POLLIN; 1136 else if (ret == TLS_WANT_POLLOUT) 1137 pfd[POLL_STDIN].events = POLLOUT; 1138 else if (ret == 0 || ret == -1) 1139 pfd[POLL_STDIN].fd = -1; 1140 /* read something - poll net out */ 1141 if (stdinbufpos > 0) 1142 pfd[POLL_NETOUT].events = POLLOUT; 1143 /* filled buffer - remove self from polling */ 1144 if (stdinbufpos == BUFSIZE) 1145 pfd[POLL_STDIN].events = 0; 1146 } 1147 /* try to write to network */ 1148 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1149 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1150 &stdinbufpos, tls_ctx); 1151 if (ret == TLS_WANT_POLLIN) 1152 pfd[POLL_NETOUT].events = POLLIN; 1153 else if (ret == TLS_WANT_POLLOUT) 1154 pfd[POLL_NETOUT].events = POLLOUT; 1155 else if (ret == -1) 1156 pfd[POLL_NETOUT].fd = -1; 1157 /* buffer empty - remove self from polling */ 1158 if (stdinbufpos == 0) 1159 pfd[POLL_NETOUT].events = 0; 1160 /* buffer no longer full - poll stdin again */ 1161 if (stdinbufpos < BUFSIZE) 1162 pfd[POLL_STDIN].events = POLLIN; 1163 } 1164 /* try to read from network */ 1165 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1166 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1167 &netinbufpos, tls_ctx); 1168 if (ret == TLS_WANT_POLLIN) 1169 pfd[POLL_NETIN].events = POLLIN; 1170 else if (ret == TLS_WANT_POLLOUT) 1171 pfd[POLL_NETIN].events = POLLOUT; 1172 else if (ret == -1) 1173 pfd[POLL_NETIN].fd = -1; 1174 /* eof on net in - remove from pfd */ 1175 if (ret == 0) { 1176 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1177 pfd[POLL_NETIN].fd = -1; 1178 } 1179 if (recvlimit > 0 && ++recvcount >= recvlimit) { 1180 if (pfd[POLL_NETIN].fd != -1) 1181 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1182 pfd[POLL_NETIN].fd = -1; 1183 pfd[POLL_STDIN].fd = -1; 1184 } 1185 /* read something - poll stdout */ 1186 if (netinbufpos > 0) 1187 pfd[POLL_STDOUT].events = POLLOUT; 1188 /* filled buffer - remove self from polling */ 1189 if (netinbufpos == BUFSIZE) 1190 pfd[POLL_NETIN].events = 0; 1191 /* handle telnet */ 1192 if (tflag) 1193 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1194 netinbufpos); 1195 } 1196 /* try to write to stdout */ 1197 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1198 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1199 &netinbufpos, NULL); 1200 if (ret == TLS_WANT_POLLIN) 1201 pfd[POLL_STDOUT].events = POLLIN; 1202 else if (ret == TLS_WANT_POLLOUT) 1203 pfd[POLL_STDOUT].events = POLLOUT; 1204 else if (ret == -1) 1205 pfd[POLL_STDOUT].fd = -1; 1206 /* buffer empty - remove self from polling */ 1207 if (netinbufpos == 0) 1208 pfd[POLL_STDOUT].events = 0; 1209 /* buffer no longer full - poll net in again */ 1210 if (netinbufpos < BUFSIZE) 1211 pfd[POLL_NETIN].events = POLLIN; 1212 } 1213 1214 /* stdin gone and queue empty? */ 1215 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1216 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1217 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1218 pfd[POLL_NETOUT].fd = -1; 1219 } 1220 /* net in gone and queue empty? */ 1221 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1222 pfd[POLL_STDOUT].fd = -1; 1223 } 1224 } 1225 } 1226 1227 ssize_t 1228 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1229 { 1230 ssize_t n; 1231 ssize_t adjust; 1232 1233 if (tls) 1234 n = tls_write(tls, buf, *bufpos); 1235 else { 1236 n = write(fd, buf, *bufpos); 1237 /* don't treat EAGAIN, EINTR as error */ 1238 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1239 n = TLS_WANT_POLLOUT; 1240 } 1241 if (n <= 0) 1242 return n; 1243 /* adjust buffer */ 1244 adjust = *bufpos - n; 1245 if (adjust > 0) 1246 memmove(buf, buf + n, adjust); 1247 *bufpos -= n; 1248 return n; 1249 } 1250 1251 ssize_t 1252 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1253 { 1254 size_t num = BUFSIZE - *bufpos; 1255 ssize_t n; 1256 1257 if (tls) 1258 n = tls_read(tls, buf + *bufpos, num); 1259 else { 1260 n = read(fd, buf + *bufpos, num); 1261 /* don't treat EAGAIN, EINTR as error */ 1262 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1263 n = TLS_WANT_POLLIN; 1264 } 1265 if (n <= 0) 1266 return n; 1267 *bufpos += n; 1268 return n; 1269 } 1270 1271 /* 1272 * fdpass() 1273 * Pass the connected file descriptor to stdout and exit. 1274 */ 1275 void 1276 fdpass(int nfd) 1277 { 1278 struct msghdr mh; 1279 union { 1280 struct cmsghdr hdr; 1281 char buf[CMSG_SPACE(sizeof(int))]; 1282 } cmsgbuf; 1283 struct cmsghdr *cmsg; 1284 struct iovec iov; 1285 char c = '\0'; 1286 ssize_t r; 1287 struct pollfd pfd; 1288 1289 /* Avoid obvious stupidity */ 1290 if (isatty(STDOUT_FILENO)) 1291 errx(1, "Cannot pass file descriptor to tty"); 1292 1293 bzero(&mh, sizeof(mh)); 1294 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1295 bzero(&iov, sizeof(iov)); 1296 1297 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1298 mh.msg_controllen = sizeof(cmsgbuf.buf); 1299 cmsg = CMSG_FIRSTHDR(&mh); 1300 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1301 cmsg->cmsg_level = SOL_SOCKET; 1302 cmsg->cmsg_type = SCM_RIGHTS; 1303 *(int *)CMSG_DATA(cmsg) = nfd; 1304 1305 iov.iov_base = &c; 1306 iov.iov_len = 1; 1307 mh.msg_iov = &iov; 1308 mh.msg_iovlen = 1; 1309 1310 bzero(&pfd, sizeof(pfd)); 1311 pfd.fd = STDOUT_FILENO; 1312 pfd.events = POLLOUT; 1313 for (;;) { 1314 r = sendmsg(STDOUT_FILENO, &mh, 0); 1315 if (r == -1) { 1316 if (errno == EAGAIN || errno == EINTR) { 1317 if (poll(&pfd, 1, -1) == -1) 1318 err(1, "poll"); 1319 continue; 1320 } 1321 err(1, "sendmsg"); 1322 } else if (r != 1) 1323 errx(1, "sendmsg: unexpected return value %zd", r); 1324 else 1325 break; 1326 } 1327 exit(0); 1328 } 1329 1330 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1331 void 1332 atelnet(int nfd, unsigned char *buf, unsigned int size) 1333 { 1334 unsigned char *p, *end; 1335 unsigned char obuf[4]; 1336 1337 if (size < 3) 1338 return; 1339 end = buf + size - 2; 1340 1341 for (p = buf; p < end; p++) { 1342 if (*p != IAC) 1343 continue; 1344 1345 obuf[0] = IAC; 1346 p++; 1347 if ((*p == WILL) || (*p == WONT)) 1348 obuf[1] = DONT; 1349 else if ((*p == DO) || (*p == DONT)) 1350 obuf[1] = WONT; 1351 else 1352 continue; 1353 1354 p++; 1355 obuf[2] = *p; 1356 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1357 warn("Write Error!"); 1358 } 1359 } 1360 1361 1362 int 1363 strtoport(char *portstr, int udp) 1364 { 1365 struct servent *entry; 1366 const char *errstr; 1367 char *proto; 1368 int port = -1; 1369 1370 proto = udp ? "udp" : "tcp"; 1371 1372 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1373 if (errstr == NULL) 1374 return port; 1375 if (errno != EINVAL) 1376 errx(1, "port number %s: %s", errstr, portstr); 1377 if ((entry = getservbyname(portstr, proto)) == NULL) 1378 errx(1, "service \"%s\" unknown", portstr); 1379 return ntohs(entry->s_port); 1380 } 1381 1382 /* 1383 * build_ports() 1384 * Build an array of ports in portlist[], listing each port 1385 * that we should try to connect to. 1386 */ 1387 void 1388 build_ports(char *p) 1389 { 1390 char *n; 1391 int hi, lo, cp; 1392 int x = 0; 1393 1394 if ((n = strchr(p, '-')) != NULL) { 1395 *n = '\0'; 1396 n++; 1397 1398 /* Make sure the ports are in order: lowest->highest. */ 1399 hi = strtoport(n, uflag); 1400 lo = strtoport(p, uflag); 1401 if (lo > hi) { 1402 cp = hi; 1403 hi = lo; 1404 lo = cp; 1405 } 1406 1407 /* 1408 * Initialize portlist with a random permutation. Based on 1409 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1410 */ 1411 if (rflag) { 1412 for (x = 0; x <= hi - lo; x++) { 1413 cp = arc4random_uniform(x + 1); 1414 portlist[x] = portlist[cp]; 1415 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1416 err(1, "asprintf"); 1417 } 1418 } else { /* Load ports sequentially. */ 1419 for (cp = lo; cp <= hi; cp++) { 1420 if (asprintf(&portlist[x], "%d", cp) < 0) 1421 err(1, "asprintf"); 1422 x++; 1423 } 1424 } 1425 } else { 1426 char *tmp; 1427 1428 hi = strtoport(p, uflag); 1429 if (asprintf(&tmp, "%d", hi) != -1) 1430 portlist[0] = tmp; 1431 else 1432 err(1, NULL); 1433 } 1434 } 1435 1436 /* 1437 * udptest() 1438 * Do a few writes to see if the UDP port is there. 1439 * Fails once PF state table is full. 1440 */ 1441 int 1442 udptest(int s) 1443 { 1444 int i, ret; 1445 1446 for (i = 0; i <= 3; i++) { 1447 if (write(s, "X", 1) == 1) 1448 ret = 1; 1449 else 1450 ret = -1; 1451 } 1452 return ret; 1453 } 1454 1455 void 1456 set_common_sockopts(int s, int af) 1457 { 1458 int x = 1; 1459 1460 if (Sflag) { 1461 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1462 &x, sizeof(x)) == -1) 1463 err(1, NULL); 1464 } 1465 if (Dflag) { 1466 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1467 &x, sizeof(x)) == -1) 1468 err(1, NULL); 1469 } 1470 if (Tflag != -1) { 1471 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1472 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1473 err(1, "set IP ToS"); 1474 1475 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1476 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1477 err(1, "set IPv6 traffic class"); 1478 } 1479 if (Iflag) { 1480 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1481 &Iflag, sizeof(Iflag)) == -1) 1482 err(1, "set TCP receive buffer size"); 1483 } 1484 if (Oflag) { 1485 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1486 &Oflag, sizeof(Oflag)) == -1) 1487 err(1, "set TCP send buffer size"); 1488 } 1489 1490 if (ttl != -1) { 1491 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1492 IP_TTL, &ttl, sizeof(ttl))) 1493 err(1, "set IP TTL"); 1494 1495 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1496 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1497 err(1, "set IPv6 unicast hops"); 1498 } 1499 1500 if (minttl != -1) { 1501 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1502 IP_MINTTL, &minttl, sizeof(minttl))) 1503 err(1, "set IP min TTL"); 1504 1505 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1506 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1507 err(1, "set IPv6 min hop count"); 1508 } 1509 } 1510 1511 int 1512 map_tos(char *s, int *val) 1513 { 1514 /* DiffServ Codepoints and other TOS mappings */ 1515 const struct toskeywords { 1516 const char *keyword; 1517 int val; 1518 } *t, toskeywords[] = { 1519 { "af11", IPTOS_DSCP_AF11 }, 1520 { "af12", IPTOS_DSCP_AF12 }, 1521 { "af13", IPTOS_DSCP_AF13 }, 1522 { "af21", IPTOS_DSCP_AF21 }, 1523 { "af22", IPTOS_DSCP_AF22 }, 1524 { "af23", IPTOS_DSCP_AF23 }, 1525 { "af31", IPTOS_DSCP_AF31 }, 1526 { "af32", IPTOS_DSCP_AF32 }, 1527 { "af33", IPTOS_DSCP_AF33 }, 1528 { "af41", IPTOS_DSCP_AF41 }, 1529 { "af42", IPTOS_DSCP_AF42 }, 1530 { "af43", IPTOS_DSCP_AF43 }, 1531 { "critical", IPTOS_PREC_CRITIC_ECP }, 1532 { "cs0", IPTOS_DSCP_CS0 }, 1533 { "cs1", IPTOS_DSCP_CS1 }, 1534 { "cs2", IPTOS_DSCP_CS2 }, 1535 { "cs3", IPTOS_DSCP_CS3 }, 1536 { "cs4", IPTOS_DSCP_CS4 }, 1537 { "cs5", IPTOS_DSCP_CS5 }, 1538 { "cs6", IPTOS_DSCP_CS6 }, 1539 { "cs7", IPTOS_DSCP_CS7 }, 1540 { "ef", IPTOS_DSCP_EF }, 1541 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1542 { "lowdelay", IPTOS_LOWDELAY }, 1543 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1544 { "reliability", IPTOS_RELIABILITY }, 1545 { "throughput", IPTOS_THROUGHPUT }, 1546 { NULL, -1 }, 1547 }; 1548 1549 for (t = toskeywords; t->keyword != NULL; t++) { 1550 if (strcmp(s, t->keyword) == 0) { 1551 *val = t->val; 1552 return 1; 1553 } 1554 } 1555 1556 return 0; 1557 } 1558 1559 int 1560 map_tls(char *s, int *val) 1561 { 1562 const struct tlskeywords { 1563 const char *keyword; 1564 int val; 1565 } *t, tlskeywords[] = { 1566 { "tlsall", TLS_ALL }, 1567 { "noverify", TLS_NOVERIFY }, 1568 { "noname", TLS_NONAME }, 1569 { "clientcert", TLS_CCERT}, 1570 { "muststaple", TLS_MUSTSTAPLE}, 1571 { "tlscompat", TLS_COMPAT }, 1572 { NULL, -1 }, 1573 }; 1574 1575 for (t = tlskeywords; t->keyword != NULL; t++) { 1576 if (strcmp(s, t->keyword) == 0) { 1577 *val |= t->val; 1578 return 1; 1579 } 1580 } 1581 return 0; 1582 } 1583 1584 void 1585 save_peer_cert(struct tls *tls_ctx, FILE *fp) 1586 { 1587 const char *pem; 1588 size_t plen; 1589 1590 if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL) 1591 errx(1, "Can't get peer certificate"); 1592 if (fprintf(fp, "%.*s", (int)plen, pem) < 0) 1593 err(1, "unable to save peer cert"); 1594 if (fflush(fp) != 0) 1595 err(1, "unable to flush peer cert"); 1596 } 1597 1598 void 1599 report_tls(struct tls * tls_ctx, char * host) 1600 { 1601 time_t t; 1602 const char *ocsp_url; 1603 1604 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1605 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1606 fprintf(stderr, "Peer name: %s\n", 1607 tls_expectname ? tls_expectname : host); 1608 if (tls_peer_cert_subject(tls_ctx)) 1609 fprintf(stderr, "Subject: %s\n", 1610 tls_peer_cert_subject(tls_ctx)); 1611 if (tls_peer_cert_issuer(tls_ctx)) 1612 fprintf(stderr, "Issuer: %s\n", 1613 tls_peer_cert_issuer(tls_ctx)); 1614 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1615 fprintf(stderr, "Valid From: %s", ctime(&t)); 1616 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1617 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1618 if (tls_peer_cert_hash(tls_ctx)) 1619 fprintf(stderr, "Cert Hash: %s\n", 1620 tls_peer_cert_hash(tls_ctx)); 1621 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1622 if (ocsp_url != NULL) 1623 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1624 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1625 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1626 fprintf(stderr, "OCSP Stapling: %s\n", 1627 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1628 tls_peer_ocsp_result(tls_ctx)); 1629 fprintf(stderr, 1630 " response_status=%d cert_status=%d crl_reason=%d\n", 1631 tls_peer_ocsp_response_status(tls_ctx), 1632 tls_peer_ocsp_cert_status(tls_ctx), 1633 tls_peer_ocsp_crl_reason(tls_ctx)); 1634 t = tls_peer_ocsp_this_update(tls_ctx); 1635 fprintf(stderr, " this update: %s", 1636 t != -1 ? ctime(&t) : "\n"); 1637 t = tls_peer_ocsp_next_update(tls_ctx); 1638 fprintf(stderr, " next update: %s", 1639 t != -1 ? ctime(&t) : "\n"); 1640 t = tls_peer_ocsp_revocation_time(tls_ctx); 1641 fprintf(stderr, " revocation: %s", 1642 t != -1 ? ctime(&t) : "\n"); 1643 break; 1644 case -1: 1645 break; 1646 default: 1647 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1648 tls_peer_ocsp_response_status(tls_ctx), 1649 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1650 tls_peer_ocsp_result(tls_ctx)); 1651 break; 1652 1653 } 1654 } 1655 1656 void 1657 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1658 { 1659 char remote_host[NI_MAXHOST]; 1660 char remote_port[NI_MAXSERV]; 1661 int herr; 1662 int flags = NI_NUMERICSERV; 1663 1664 if (path != NULL) { 1665 fprintf(stderr, "Connection on %s received!\n", path); 1666 return; 1667 } 1668 1669 if (nflag) 1670 flags |= NI_NUMERICHOST; 1671 1672 if ((herr = getnameinfo(sa, salen, 1673 remote_host, sizeof(remote_host), 1674 remote_port, sizeof(remote_port), 1675 flags)) != 0) { 1676 if (herr == EAI_SYSTEM) 1677 err(1, "getnameinfo"); 1678 else 1679 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1680 } 1681 1682 fprintf(stderr, 1683 "Connection from %s %s " 1684 "received!\n", remote_host, remote_port); 1685 } 1686 1687 void 1688 help(void) 1689 { 1690 usage(0); 1691 fprintf(stderr, "\tCommand Summary:\n\ 1692 \t-4 Use IPv4\n\ 1693 \t-6 Use IPv6\n\ 1694 \t-C certfile Public key file\n\ 1695 \t-c Use TLS\n\ 1696 \t-D Enable the debug socket option\n\ 1697 \t-d Detach from stdin\n\ 1698 \t-e name\t Required name in peer certificate\n\ 1699 \t-F Pass socket fd\n\ 1700 \t-H hash\t Hash string of peer certificate\n\ 1701 \t-h This help text\n\ 1702 \t-I length TCP receive buffer length\n\ 1703 \t-i interval Delay interval for lines sent, ports scanned\n\ 1704 \t-K keyfile Private key file\n\ 1705 \t-k Keep inbound sockets open for multiple connects\n\ 1706 \t-l Listen mode, for inbound connects\n\ 1707 \t-M ttl Outgoing TTL / Hop Limit\n\ 1708 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1709 \t-N Shutdown the network socket after EOF on stdin\n\ 1710 \t-n Suppress name/port resolutions\n\ 1711 \t-O length TCP send buffer length\n\ 1712 \t-o staplefile Staple file\n\ 1713 \t-P proxyuser\tUsername for proxy authentication\n\ 1714 \t-p port\t Specify local port for remote connects\n\ 1715 \t-R CAfile CA bundle\n\ 1716 \t-r Randomize remote ports\n\ 1717 \t-S Enable the TCP MD5 signature option\n\ 1718 \t-s source Local source address\n\ 1719 \t-T keyword TOS value or TLS options\n\ 1720 \t-t Answer TELNET negotiation\n\ 1721 \t-U Use UNIX domain socket\n\ 1722 \t-u UDP mode\n\ 1723 \t-V rtable Specify alternate routing table\n\ 1724 \t-v Verbose\n\ 1725 \t-W recvlimit Terminate after receiving a number of packets\n\ 1726 \t-w timeout Timeout for connects and final net reads\n\ 1727 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1728 \t-x addr[:port]\tSpecify proxy address and port\n\ 1729 \t-Z Peer certificate file\n\ 1730 \t-z Zero-I/O mode [used for scanning]\n\ 1731 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1732 exit(1); 1733 } 1734 1735 void 1736 usage(int ret) 1737 { 1738 fprintf(stderr, 1739 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1740 "[-H hash] [-I length]\n" 1741 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1742 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1743 "[-R CAfile]\n" 1744 "\t [-s source] [-T keyword] [-V rtable] [-W recvlimit] " 1745 "[-w timeout]\n" 1746 "\t [-X proxy_protocol] [-x proxy_address[:port]] " 1747 "[-Z peercertfile]\n" 1748 "\t [destination] [port]\n"); 1749 if (ret) 1750 exit(1); 1751 } 1752