1 /* $OpenBSD: netcat.c,v 1.203 2019/02/26 17:32:47 jsing 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 #ifdef TCP_MD5SIG 97 int Sflag; /* TCP MD5 signature option */ 98 #endif 99 int Tflag = -1; /* IP Type of Service */ 100 #ifdef SO_RTABLE 101 int rtableid = -1; 102 #endif 103 104 int usetls; /* use TLS */ 105 const char *Cflag; /* Public cert file */ 106 const char *Kflag; /* Private key file */ 107 const char *oflag; /* OCSP stapling file */ 108 const char *Rflag; /* Root CA file */ 109 int tls_cachanged; /* Using non-default CA file */ 110 int TLSopt; /* TLS options */ 111 char *tls_expectname; /* required name in peer cert */ 112 char *tls_expecthash; /* required hash of peer cert */ 113 char *tls_ciphers; /* TLS ciphers */ 114 char *tls_protocols; /* TLS protocols */ 115 FILE *Zflag; /* file to save peer cert */ 116 117 int recvcount, recvlimit; 118 int timeout = -1; 119 int family = AF_UNSPEC; 120 char *portlist[PORT_MAX+1]; 121 char *unix_dg_tmp_socket; 122 int ttl = -1; 123 int minttl = -1; 124 125 void atelnet(int, unsigned char *, unsigned int); 126 int strtoport(char *portstr, int udp); 127 void build_ports(char *); 128 void help(void) __attribute__((noreturn)); 129 int local_listen(const char *, const char *, struct addrinfo); 130 void readwrite(int, struct tls *); 131 void fdpass(int nfd) __attribute__((noreturn)); 132 int remote_connect(const char *, const char *, struct addrinfo); 133 int timeout_tls(int, struct tls *, int (*)(struct tls *)); 134 int timeout_connect(int, const struct sockaddr *, socklen_t); 135 int socks_connect(const char *, const char *, struct addrinfo, 136 const char *, const char *, struct addrinfo, int, const char *); 137 int udptest(int); 138 int unix_bind(char *, int); 139 int unix_connect(char *); 140 int unix_listen(char *); 141 void set_common_sockopts(int, int); 142 int process_tos_opt(char *, int *); 143 int process_tls_opt(char *, int *); 144 void save_peer_cert(struct tls *_tls_ctx, FILE *_fp); 145 void report_sock(const char *, const struct sockaddr *, socklen_t, char *); 146 void report_tls(struct tls *tls_ctx, char * host); 147 void usage(int); 148 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 149 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 150 void tls_setup_client(struct tls *, int, char *); 151 struct tls *tls_setup_server(struct tls *, int, char *); 152 153 int 154 main(int argc, char *argv[]) 155 { 156 int ch, s = -1, ret, socksv; 157 char *host, *uport; 158 struct addrinfo hints; 159 struct servent *sv; 160 socklen_t len; 161 struct sockaddr_storage cliaddr; 162 char *proxy = NULL, *proxyport = NULL; 163 const char *errstr; 164 struct addrinfo proxyhints; 165 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 166 struct tls_config *tls_cfg = NULL; 167 struct tls *tls_ctx = NULL; 168 uint32_t protocols; 169 170 ret = 1; 171 socksv = 5; 172 host = NULL; 173 uport = NULL; 174 sv = NULL; 175 Rflag = tls_default_ca_cert_file(); 176 177 signal(SIGPIPE, SIG_IGN); 178 179 while ((ch = getopt(argc, argv, 180 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z")) 181 != -1) { 182 switch (ch) { 183 case '4': 184 family = AF_INET; 185 break; 186 case '6': 187 family = AF_INET6; 188 break; 189 case 'U': 190 family = AF_UNIX; 191 break; 192 case 'X': 193 if (strcasecmp(optarg, "connect") == 0) 194 socksv = -1; /* HTTP proxy CONNECT */ 195 else if (strcmp(optarg, "4") == 0) 196 socksv = 4; /* SOCKS v.4 */ 197 else if (strcmp(optarg, "5") == 0) 198 socksv = 5; /* SOCKS v.5 */ 199 else 200 errx(1, "unsupported proxy protocol"); 201 break; 202 case 'C': 203 Cflag = optarg; 204 break; 205 case 'c': 206 usetls = 1; 207 break; 208 case 'd': 209 dflag = 1; 210 break; 211 case 'e': 212 tls_expectname = optarg; 213 break; 214 case 'F': 215 Fflag = 1; 216 break; 217 case 'H': 218 tls_expecthash = optarg; 219 break; 220 case 'h': 221 help(); 222 break; 223 case 'i': 224 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 225 if (errstr) 226 errx(1, "interval %s: %s", errstr, optarg); 227 break; 228 case 'K': 229 Kflag = optarg; 230 break; 231 case 'k': 232 kflag = 1; 233 break; 234 case 'l': 235 lflag = 1; 236 break; 237 case 'M': 238 ttl = strtonum(optarg, 0, 255, &errstr); 239 if (errstr) 240 errx(1, "ttl is %s", errstr); 241 break; 242 case 'm': 243 minttl = strtonum(optarg, 0, 255, &errstr); 244 if (errstr) 245 errx(1, "minttl is %s", errstr); 246 break; 247 case 'N': 248 Nflag = 1; 249 break; 250 case 'n': 251 nflag = 1; 252 break; 253 case 'P': 254 Pflag = optarg; 255 break; 256 case 'p': 257 pflag = optarg; 258 break; 259 case 'R': 260 tls_cachanged = 1; 261 Rflag = optarg; 262 break; 263 case 'r': 264 rflag = 1; 265 break; 266 case 's': 267 sflag = optarg; 268 break; 269 case 't': 270 tflag = 1; 271 break; 272 case 'u': 273 uflag = 1; 274 break; 275 #ifdef SO_RTABLE 276 case 'V': 277 rtableid = (int)strtonum(optarg, 0, 278 RT_TABLEID_MAX, &errstr); 279 if (errstr) 280 errx(1, "rtable %s: %s", errstr, optarg); 281 break; 282 #endif 283 case 'v': 284 vflag = 1; 285 break; 286 case 'W': 287 recvlimit = strtonum(optarg, 1, INT_MAX, &errstr); 288 if (errstr) 289 errx(1, "receive limit %s: %s", errstr, optarg); 290 break; 291 case 'w': 292 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 293 if (errstr) 294 errx(1, "timeout %s: %s", errstr, optarg); 295 timeout *= 1000; 296 break; 297 case 'x': 298 xflag = 1; 299 if ((proxy = strdup(optarg)) == NULL) 300 err(1, NULL); 301 break; 302 case 'Z': 303 if (strcmp(optarg, "-") == 0) 304 Zflag = stderr; 305 else if ((Zflag = fopen(optarg, "w")) == NULL) 306 err(1, "can't open %s", optarg); 307 break; 308 case 'z': 309 zflag = 1; 310 break; 311 case 'D': 312 Dflag = 1; 313 break; 314 case 'I': 315 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 316 if (errstr != NULL) 317 errx(1, "TCP receive window %s: %s", 318 errstr, optarg); 319 break; 320 case 'O': 321 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 322 if (errstr != NULL) 323 errx(1, "TCP send window %s: %s", 324 errstr, optarg); 325 break; 326 case 'o': 327 oflag = optarg; 328 break; 329 #ifdef TCP_MD5SIG 330 case 'S': 331 Sflag = 1; 332 break; 333 #endif 334 case 'T': 335 errstr = NULL; 336 errno = 0; 337 if (process_tls_opt(optarg, &TLSopt)) 338 break; 339 if (process_tos_opt(optarg, &Tflag)) 340 break; 341 if (strlen(optarg) > 1 && optarg[0] == '0' && 342 optarg[1] == 'x') 343 Tflag = (int)strtol(optarg, NULL, 16); 344 else 345 Tflag = (int)strtonum(optarg, 0, 255, 346 &errstr); 347 if (Tflag < 0 || Tflag > 255 || errstr || errno) 348 errx(1, "illegal tos/tls value %s", optarg); 349 break; 350 default: 351 usage(1); 352 } 353 } 354 argc -= optind; 355 argv += optind; 356 357 #ifdef SO_RTABLE 358 if (rtableid >= 0) 359 if (setrtable(rtableid) == -1) 360 err(1, "setrtable"); 361 #endif 362 363 /* Cruft to make sure options are clean, and used properly. */ 364 if (argv[0] && !argv[1] && family == AF_UNIX) { 365 host = argv[0]; 366 uport = NULL; 367 } else if (argv[0] && !argv[1]) { 368 if (!lflag) 369 usage(1); 370 uport = argv[0]; 371 host = NULL; 372 } else if (argv[0] && argv[1]) { 373 host = argv[0]; 374 uport = argv[1]; 375 } else 376 usage(1); 377 378 if (usetls) { 379 if (Cflag && unveil(Cflag, "r") == -1) 380 err(1, "unveil"); 381 if (unveil(Rflag, "r") == -1) 382 err(1, "unveil"); 383 if (Kflag && unveil(Kflag, "r") == -1) 384 err(1, "unveil"); 385 if (oflag && unveil(oflag, "r") == -1) 386 err(1, "unveil"); 387 } else { 388 if (family == AF_UNIX) { 389 if (unveil(host, "rwc") == -1) 390 err(1, "unveil"); 391 if (uflag && !lflag) { 392 if (unveil(sflag ? sflag : "/tmp", "rwc") == -1) 393 err(1, "unveil"); 394 } 395 } else { 396 if (unveil("/", "") == -1) 397 err(1, "unveil"); 398 } 399 } 400 401 if (family == AF_UNIX) { 402 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 403 err(1, "pledge"); 404 } else if (Fflag && Pflag) { 405 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 406 err(1, "pledge"); 407 } else if (Fflag) { 408 if (pledge("stdio inet dns sendfd", NULL) == -1) 409 err(1, "pledge"); 410 } else if (Pflag && usetls) { 411 if (pledge("stdio rpath inet dns tty", NULL) == -1) 412 err(1, "pledge"); 413 } else if (Pflag) { 414 if (pledge("stdio inet dns tty", NULL) == -1) 415 err(1, "pledge"); 416 } else if (usetls) { 417 if (pledge("stdio rpath inet dns", NULL) == -1) 418 err(1, "pledge"); 419 } else if (pledge("stdio inet dns", NULL) == -1) 420 err(1, "pledge"); 421 422 if (lflag && sflag) 423 errx(1, "cannot use -s and -l"); 424 if (lflag && pflag) 425 errx(1, "cannot use -p and -l"); 426 if (lflag && zflag) 427 errx(1, "cannot use -z and -l"); 428 if (!lflag && kflag) 429 errx(1, "must use -l with -k"); 430 if (uflag && usetls) 431 errx(1, "cannot use -c and -u"); 432 if ((family == AF_UNIX) && usetls) 433 errx(1, "cannot use -c and -U"); 434 if ((family == AF_UNIX) && Fflag) 435 errx(1, "cannot use -F and -U"); 436 if (Fflag && usetls) 437 errx(1, "cannot use -c and -F"); 438 if (TLSopt && !usetls) 439 errx(1, "you must specify -c to use TLS options"); 440 if (Cflag && !usetls) 441 errx(1, "you must specify -c to use -C"); 442 if (Kflag && !usetls) 443 errx(1, "you must specify -c to use -K"); 444 if (Zflag && !usetls) 445 errx(1, "you must specify -c to use -Z"); 446 if (oflag && !Cflag) 447 errx(1, "you must specify -C to use -o"); 448 if (tls_cachanged && !usetls) 449 errx(1, "you must specify -c to use -R"); 450 if (tls_expecthash && !usetls) 451 errx(1, "you must specify -c to use -H"); 452 if (tls_expectname && !usetls) 453 errx(1, "you must specify -c to use -e"); 454 455 /* Get name of temporary socket for unix datagram client */ 456 if ((family == AF_UNIX) && uflag && !lflag) { 457 if (sflag) { 458 unix_dg_tmp_socket = sflag; 459 } else { 460 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 461 UNIX_DG_TMP_SOCKET_SIZE); 462 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 463 err(1, "mktemp"); 464 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 465 } 466 } 467 468 /* Initialize addrinfo structure. */ 469 if (family != AF_UNIX) { 470 memset(&hints, 0, sizeof(struct addrinfo)); 471 hints.ai_family = family; 472 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 473 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 474 if (nflag) 475 hints.ai_flags |= AI_NUMERICHOST; 476 } 477 478 if (xflag) { 479 if (uflag) 480 errx(1, "no proxy support for UDP mode"); 481 482 if (lflag) 483 errx(1, "no proxy support for listen"); 484 485 if (family == AF_UNIX) 486 errx(1, "no proxy support for unix sockets"); 487 488 if (sflag) 489 errx(1, "no proxy support for local source address"); 490 491 if (*proxy == '[') { 492 ++proxy; 493 proxyport = strchr(proxy, ']'); 494 if (proxyport == NULL) 495 errx(1, "missing closing bracket in proxy"); 496 *proxyport++ = '\0'; 497 if (*proxyport == '\0') 498 /* Use default proxy port. */ 499 proxyport = NULL; 500 else { 501 if (*proxyport == ':') 502 ++proxyport; 503 else 504 errx(1, "garbage proxy port delimiter"); 505 } 506 } else { 507 proxyport = strrchr(proxy, ':'); 508 if (proxyport != NULL) 509 *proxyport++ = '\0'; 510 } 511 512 memset(&proxyhints, 0, sizeof(struct addrinfo)); 513 proxyhints.ai_family = family; 514 proxyhints.ai_socktype = SOCK_STREAM; 515 proxyhints.ai_protocol = IPPROTO_TCP; 516 if (nflag) 517 proxyhints.ai_flags |= AI_NUMERICHOST; 518 } 519 520 if (usetls) { 521 if ((tls_cfg = tls_config_new()) == NULL) 522 errx(1, "unable to allocate TLS config"); 523 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 524 errx(1, "%s", tls_config_error(tls_cfg)); 525 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 526 errx(1, "%s", tls_config_error(tls_cfg)); 527 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 528 errx(1, "%s", tls_config_error(tls_cfg)); 529 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 530 errx(1, "%s", tls_config_error(tls_cfg)); 531 if (tls_config_parse_protocols(&protocols, tls_protocols) == -1) 532 errx(1, "invalid TLS protocols `%s'", tls_protocols); 533 if (tls_config_set_protocols(tls_cfg, protocols) == -1) 534 errx(1, "%s", tls_config_error(tls_cfg)); 535 if (tls_config_set_ciphers(tls_cfg, tls_ciphers) == -1) 536 errx(1, "%s", tls_config_error(tls_cfg)); 537 if (!lflag && (TLSopt & TLS_CCERT)) 538 errx(1, "clientcert is only valid with -l"); 539 if (TLSopt & TLS_NONAME) 540 tls_config_insecure_noverifyname(tls_cfg); 541 if (TLSopt & TLS_NOVERIFY) { 542 if (tls_expecthash != NULL) 543 errx(1, "-H and -T noverify may not be used " 544 "together"); 545 tls_config_insecure_noverifycert(tls_cfg); 546 } 547 if (TLSopt & TLS_MUSTSTAPLE) 548 tls_config_ocsp_require_stapling(tls_cfg); 549 550 if (Pflag) { 551 if (pledge("stdio inet dns tty", NULL) == -1) 552 err(1, "pledge"); 553 } else if (pledge("stdio inet dns", NULL) == -1) 554 err(1, "pledge"); 555 } 556 if (lflag) { 557 ret = 0; 558 559 if (family == AF_UNIX) { 560 if (uflag) 561 s = unix_bind(host, 0); 562 else 563 s = unix_listen(host); 564 } 565 566 if (usetls) { 567 tls_config_verify_client_optional(tls_cfg); 568 if ((tls_ctx = tls_server()) == NULL) 569 errx(1, "tls server creation failed"); 570 if (tls_configure(tls_ctx, tls_cfg) == -1) 571 errx(1, "tls configuration failed (%s)", 572 tls_error(tls_ctx)); 573 } 574 /* Allow only one connection at a time, but stay alive. */ 575 for (;;) { 576 if (family != AF_UNIX) { 577 if (s != -1) 578 close(s); 579 s = local_listen(host, uport, hints); 580 } 581 if (s < 0) 582 err(1, NULL); 583 if (uflag && kflag) { 584 /* 585 * For UDP and -k, don't connect the socket, 586 * let it receive datagrams from multiple 587 * socket pairs. 588 */ 589 readwrite(s, NULL); 590 } else if (uflag && !kflag) { 591 /* 592 * For UDP and not -k, we will use recvfrom() 593 * initially to wait for a caller, then use 594 * the regular functions to talk to the caller. 595 */ 596 int rv; 597 char buf[2048]; 598 struct sockaddr_storage z; 599 600 len = sizeof(z); 601 rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK, 602 (struct sockaddr *)&z, &len); 603 if (rv < 0) 604 err(1, "recvfrom"); 605 606 rv = connect(s, (struct sockaddr *)&z, len); 607 if (rv < 0) 608 err(1, "connect"); 609 610 if (vflag) 611 report_sock("Connection received", 612 (struct sockaddr *)&z, len, NULL); 613 614 readwrite(s, NULL); 615 } else { 616 struct tls *tls_cctx = NULL; 617 int connfd; 618 619 len = sizeof(cliaddr); 620 connfd = accept4(s, (struct sockaddr *)&cliaddr, 621 &len, SOCK_NONBLOCK); 622 if (connfd == -1) { 623 /* For now, all errnos are fatal */ 624 err(1, "accept"); 625 } 626 if (vflag) 627 report_sock("Connection received", 628 (struct sockaddr *)&cliaddr, len, 629 family == AF_UNIX ? host : NULL); 630 if ((usetls) && 631 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 632 readwrite(connfd, tls_cctx); 633 if (!usetls) 634 readwrite(connfd, NULL); 635 if (tls_cctx) 636 timeout_tls(s, tls_cctx, tls_close); 637 close(connfd); 638 tls_free(tls_cctx); 639 } 640 if (family == AF_UNIX && uflag) { 641 if (connect(s, NULL, 0) < 0) 642 err(1, "connect"); 643 } 644 645 if (!kflag) 646 break; 647 } 648 } else if (family == AF_UNIX) { 649 ret = 0; 650 651 if ((s = unix_connect(host)) > 0) { 652 if (!zflag) 653 readwrite(s, NULL); 654 close(s); 655 } else { 656 warn("%s", host); 657 ret = 1; 658 } 659 660 if (uflag) 661 unlink(unix_dg_tmp_socket); 662 return ret; 663 664 } else { 665 int i = 0; 666 667 /* Construct the portlist[] array. */ 668 build_ports(uport); 669 670 /* Cycle through portlist, connecting to each port. */ 671 for (s = -1, i = 0; portlist[i] != NULL; i++) { 672 if (s != -1) 673 close(s); 674 tls_free(tls_ctx); 675 tls_ctx = NULL; 676 677 if (usetls) { 678 if ((tls_ctx = tls_client()) == NULL) 679 errx(1, "tls client creation failed"); 680 if (tls_configure(tls_ctx, tls_cfg) == -1) 681 errx(1, "tls configuration failed (%s)", 682 tls_error(tls_ctx)); 683 } 684 if (xflag) 685 s = socks_connect(host, portlist[i], hints, 686 proxy, proxyport, proxyhints, socksv, 687 Pflag); 688 else 689 s = remote_connect(host, portlist[i], hints); 690 691 if (s == -1) 692 continue; 693 694 ret = 0; 695 if (vflag || zflag) { 696 /* For UDP, make sure we are connected. */ 697 if (uflag) { 698 if (udptest(s) == -1) { 699 ret = 1; 700 continue; 701 } 702 } 703 704 /* Don't look up port if -n. */ 705 if (nflag) 706 sv = NULL; 707 else { 708 sv = getservbyport( 709 ntohs(atoi(portlist[i])), 710 uflag ? "udp" : "tcp"); 711 } 712 713 fprintf(stderr, 714 "Connection to %s %s port [%s/%s] " 715 "succeeded!\n", host, portlist[i], 716 uflag ? "udp" : "tcp", 717 sv ? sv->s_name : "*"); 718 } 719 if (Fflag) 720 fdpass(s); 721 else { 722 if (usetls) 723 tls_setup_client(tls_ctx, s, host); 724 if (!zflag) 725 readwrite(s, tls_ctx); 726 if (tls_ctx) 727 timeout_tls(s, tls_ctx, tls_close); 728 } 729 } 730 } 731 732 if (s != -1) 733 close(s); 734 tls_free(tls_ctx); 735 tls_config_free(tls_cfg); 736 737 return ret; 738 } 739 740 /* 741 * unix_bind() 742 * Returns a unix socket bound to the given path 743 */ 744 int 745 unix_bind(char *path, int flags) 746 { 747 struct sockaddr_un s_un; 748 int s, save_errno; 749 750 /* Create unix domain socket. */ 751 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 752 0)) < 0) 753 return -1; 754 755 memset(&s_un, 0, sizeof(struct sockaddr_un)); 756 s_un.sun_family = AF_UNIX; 757 758 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 759 sizeof(s_un.sun_path)) { 760 close(s); 761 errno = ENAMETOOLONG; 762 return -1; 763 } 764 765 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 766 save_errno = errno; 767 close(s); 768 errno = save_errno; 769 return -1; 770 } 771 if (vflag) 772 report_sock("Bound", NULL, 0, path); 773 774 return s; 775 } 776 777 int 778 timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) 779 { 780 struct pollfd pfd; 781 int ret; 782 783 while ((ret = (*func)(tls_ctx)) != 0) { 784 if (ret == TLS_WANT_POLLIN) 785 pfd.events = POLLIN; 786 else if (ret == TLS_WANT_POLLOUT) 787 pfd.events = POLLOUT; 788 else 789 break; 790 pfd.fd = s; 791 if ((ret = poll(&pfd, 1, timeout)) == 1) 792 continue; 793 else if (ret == 0) { 794 errno = ETIMEDOUT; 795 ret = -1; 796 break; 797 } else 798 err(1, "poll failed"); 799 } 800 801 return ret; 802 } 803 804 void 805 tls_setup_client(struct tls *tls_ctx, int s, char *host) 806 { 807 const char *errstr; 808 809 if (tls_connect_socket(tls_ctx, s, 810 tls_expectname ? tls_expectname : host) == -1) { 811 errx(1, "tls connection failed (%s)", 812 tls_error(tls_ctx)); 813 } 814 if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { 815 if ((errstr = tls_error(tls_ctx)) == NULL) 816 errstr = strerror(errno); 817 errx(1, "tls handshake failed (%s)", errstr); 818 } 819 if (vflag) 820 report_tls(tls_ctx, host); 821 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 822 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 823 errx(1, "peer certificate is not %s", tls_expecthash); 824 if (Zflag) { 825 save_peer_cert(tls_ctx, Zflag); 826 if (Zflag != stderr && (fclose(Zflag) != 0)) 827 err(1, "fclose failed saving peer cert"); 828 } 829 } 830 831 struct tls * 832 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 833 { 834 struct tls *tls_cctx; 835 const char *errstr; 836 837 if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { 838 warnx("tls accept failed (%s)", tls_error(tls_ctx)); 839 } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { 840 if ((errstr = tls_error(tls_cctx)) == NULL) 841 errstr = strerror(errno); 842 warnx("tls handshake failed (%s)", errstr); 843 } else { 844 int gotcert = tls_peer_cert_provided(tls_cctx); 845 846 if (vflag && gotcert) 847 report_tls(tls_cctx, host); 848 if ((TLSopt & TLS_CCERT) && !gotcert) 849 warnx("No client certificate provided"); 850 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 851 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 852 warnx("peer certificate is not %s", tls_expecthash); 853 else if (gotcert && tls_expectname && 854 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 855 warnx("name (%s) not found in client cert", 856 tls_expectname); 857 else { 858 return tls_cctx; 859 } 860 } 861 return NULL; 862 } 863 864 /* 865 * unix_connect() 866 * Returns a socket connected to a local unix socket. Returns -1 on failure. 867 */ 868 int 869 unix_connect(char *path) 870 { 871 struct sockaddr_un s_un; 872 int s, save_errno; 873 874 if (uflag) { 875 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 876 return -1; 877 } else { 878 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 879 return -1; 880 } 881 882 memset(&s_un, 0, sizeof(struct sockaddr_un)); 883 s_un.sun_family = AF_UNIX; 884 885 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 886 sizeof(s_un.sun_path)) { 887 close(s); 888 errno = ENAMETOOLONG; 889 return -1; 890 } 891 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 892 save_errno = errno; 893 close(s); 894 errno = save_errno; 895 return -1; 896 } 897 return s; 898 899 } 900 901 /* 902 * unix_listen() 903 * Create a unix domain socket, and listen on it. 904 */ 905 int 906 unix_listen(char *path) 907 { 908 int s; 909 910 if ((s = unix_bind(path, 0)) < 0) 911 return -1; 912 if (listen(s, 5) < 0) { 913 close(s); 914 return -1; 915 } 916 if (vflag) 917 report_sock("Listening", NULL, 0, path); 918 919 return s; 920 } 921 922 /* 923 * remote_connect() 924 * Returns a socket connected to a remote host. Properly binds to a local 925 * port or source address if needed. Returns -1 on failure. 926 */ 927 int 928 remote_connect(const char *host, const char *port, struct addrinfo hints) 929 { 930 struct addrinfo *res, *res0; 931 int s = -1, error, save_errno; 932 #ifdef SO_BINDANY 933 int on = 1; 934 #endif 935 936 if ((error = getaddrinfo(host, port, &hints, &res0))) 937 errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, 938 port, gai_strerror(error)); 939 940 for (res = res0; res; res = res->ai_next) { 941 if ((s = socket(res->ai_family, res->ai_socktype | 942 SOCK_NONBLOCK, res->ai_protocol)) < 0) 943 continue; 944 945 /* Bind to a local port or source address if specified. */ 946 if (sflag || pflag) { 947 struct addrinfo ahints, *ares; 948 949 #ifdef SO_BINDANY 950 /* try SO_BINDANY, but don't insist */ 951 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 952 #endif 953 memset(&ahints, 0, sizeof(struct addrinfo)); 954 ahints.ai_family = res->ai_family; 955 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 956 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 957 ahints.ai_flags = AI_PASSIVE; 958 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 959 errx(1, "getaddrinfo: %s", gai_strerror(error)); 960 961 if (bind(s, (struct sockaddr *)ares->ai_addr, 962 ares->ai_addrlen) < 0) 963 err(1, "bind failed"); 964 freeaddrinfo(ares); 965 } 966 967 set_common_sockopts(s, res->ai_family); 968 969 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 970 break; 971 if (vflag) 972 warn("connect to %s port %s (%s) failed", host, port, 973 uflag ? "udp" : "tcp"); 974 975 save_errno = errno; 976 close(s); 977 errno = save_errno; 978 s = -1; 979 } 980 981 freeaddrinfo(res0); 982 983 return s; 984 } 985 986 int 987 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 988 { 989 struct pollfd pfd; 990 socklen_t optlen; 991 int optval; 992 int ret; 993 994 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 995 pfd.fd = s; 996 pfd.events = POLLOUT; 997 if ((ret = poll(&pfd, 1, timeout)) == 1) { 998 optlen = sizeof(optval); 999 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 1000 &optval, &optlen)) == 0) { 1001 errno = optval; 1002 ret = optval == 0 ? 0 : -1; 1003 } 1004 } else if (ret == 0) { 1005 errno = ETIMEDOUT; 1006 ret = -1; 1007 } else 1008 err(1, "poll failed"); 1009 } 1010 1011 return ret; 1012 } 1013 1014 /* 1015 * local_listen() 1016 * Returns a socket listening on a local port, binds to specified source 1017 * address. Returns -1 on failure. 1018 */ 1019 int 1020 local_listen(const char *host, const char *port, struct addrinfo hints) 1021 { 1022 struct addrinfo *res, *res0; 1023 int s = -1, save_errno; 1024 #ifdef SO_REUSEPORT 1025 int ret, x = 1; 1026 #endif 1027 int error; 1028 1029 /* Allow nodename to be null. */ 1030 hints.ai_flags |= AI_PASSIVE; 1031 1032 /* 1033 * In the case of binding to a wildcard address 1034 * default to binding to an ipv4 address. 1035 */ 1036 if (host == NULL && hints.ai_family == AF_UNSPEC) 1037 hints.ai_family = AF_INET; 1038 1039 if ((error = getaddrinfo(host, port, &hints, &res0))) 1040 errx(1, "getaddrinfo: %s", gai_strerror(error)); 1041 1042 for (res = res0; res; res = res->ai_next) { 1043 if ((s = socket(res->ai_family, res->ai_socktype, 1044 res->ai_protocol)) < 0) 1045 continue; 1046 1047 #ifdef SO_REUSEPORT 1048 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 1049 if (ret == -1) 1050 err(1, NULL); 1051 #endif 1052 1053 set_common_sockopts(s, res->ai_family); 1054 1055 if (bind(s, (struct sockaddr *)res->ai_addr, 1056 res->ai_addrlen) == 0) 1057 break; 1058 1059 save_errno = errno; 1060 close(s); 1061 errno = save_errno; 1062 s = -1; 1063 } 1064 1065 if (!uflag && s != -1) { 1066 if (listen(s, 1) < 0) 1067 err(1, "listen"); 1068 } 1069 if (vflag && s != -1) { 1070 struct sockaddr_storage ss; 1071 socklen_t len; 1072 1073 len = sizeof(ss); 1074 if (getsockname(s, (struct sockaddr *)&ss, &len) == -1) 1075 err(1, "getsockname"); 1076 report_sock(uflag ? "Bound" : "Listening", 1077 (struct sockaddr *)&ss, len, NULL); 1078 } 1079 1080 freeaddrinfo(res0); 1081 1082 return s; 1083 } 1084 1085 /* 1086 * readwrite() 1087 * Loop that polls on the network file descriptor and stdin. 1088 */ 1089 void 1090 readwrite(int net_fd, struct tls *tls_ctx) 1091 { 1092 struct pollfd pfd[4]; 1093 int stdin_fd = STDIN_FILENO; 1094 int stdout_fd = STDOUT_FILENO; 1095 unsigned char netinbuf[BUFSIZE]; 1096 size_t netinbufpos = 0; 1097 unsigned char stdinbuf[BUFSIZE]; 1098 size_t stdinbufpos = 0; 1099 int n, num_fds; 1100 ssize_t ret; 1101 1102 /* don't read from stdin if requested */ 1103 if (dflag) 1104 stdin_fd = -1; 1105 1106 /* stdin */ 1107 pfd[POLL_STDIN].fd = stdin_fd; 1108 pfd[POLL_STDIN].events = POLLIN; 1109 1110 /* network out */ 1111 pfd[POLL_NETOUT].fd = net_fd; 1112 pfd[POLL_NETOUT].events = 0; 1113 1114 /* network in */ 1115 pfd[POLL_NETIN].fd = net_fd; 1116 pfd[POLL_NETIN].events = POLLIN; 1117 1118 /* stdout */ 1119 pfd[POLL_STDOUT].fd = stdout_fd; 1120 pfd[POLL_STDOUT].events = 0; 1121 1122 while (1) { 1123 /* both inputs are gone, buffers are empty, we are done */ 1124 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1125 stdinbufpos == 0 && netinbufpos == 0) 1126 return; 1127 /* both outputs are gone, we can't continue */ 1128 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) 1129 return; 1130 /* listen and net in gone, queues empty, done */ 1131 if (lflag && pfd[POLL_NETIN].fd == -1 && 1132 stdinbufpos == 0 && netinbufpos == 0) 1133 return; 1134 1135 /* help says -i is for "wait between lines sent". We read and 1136 * write arbitrary amounts of data, and we don't want to start 1137 * scanning for newlines, so this is as good as it gets */ 1138 if (iflag) 1139 sleep(iflag); 1140 1141 /* poll */ 1142 num_fds = poll(pfd, 4, timeout); 1143 1144 /* treat poll errors */ 1145 if (num_fds == -1) 1146 err(1, "polling error"); 1147 1148 /* timeout happened */ 1149 if (num_fds == 0) 1150 return; 1151 1152 /* treat socket error conditions */ 1153 for (n = 0; n < 4; n++) { 1154 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1155 pfd[n].fd = -1; 1156 } 1157 } 1158 /* reading is possible after HUP */ 1159 if (pfd[POLL_STDIN].events & POLLIN && 1160 pfd[POLL_STDIN].revents & POLLHUP && 1161 !(pfd[POLL_STDIN].revents & POLLIN)) 1162 pfd[POLL_STDIN].fd = -1; 1163 1164 if (pfd[POLL_NETIN].events & POLLIN && 1165 pfd[POLL_NETIN].revents & POLLHUP && 1166 !(pfd[POLL_NETIN].revents & POLLIN)) 1167 pfd[POLL_NETIN].fd = -1; 1168 1169 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1170 if (Nflag) 1171 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1172 pfd[POLL_NETOUT].fd = -1; 1173 } 1174 /* if HUP, stop watching stdout */ 1175 if (pfd[POLL_STDOUT].revents & POLLHUP) 1176 pfd[POLL_STDOUT].fd = -1; 1177 /* if no net out, stop watching stdin */ 1178 if (pfd[POLL_NETOUT].fd == -1) 1179 pfd[POLL_STDIN].fd = -1; 1180 /* if no stdout, stop watching net in */ 1181 if (pfd[POLL_STDOUT].fd == -1) { 1182 if (pfd[POLL_NETIN].fd != -1) 1183 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1184 pfd[POLL_NETIN].fd = -1; 1185 } 1186 1187 /* try to read from stdin */ 1188 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1189 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1190 &stdinbufpos, NULL); 1191 if (ret == TLS_WANT_POLLIN) 1192 pfd[POLL_STDIN].events = POLLIN; 1193 else if (ret == TLS_WANT_POLLOUT) 1194 pfd[POLL_STDIN].events = POLLOUT; 1195 else if (ret == 0 || ret == -1) 1196 pfd[POLL_STDIN].fd = -1; 1197 /* read something - poll net out */ 1198 if (stdinbufpos > 0) 1199 pfd[POLL_NETOUT].events = POLLOUT; 1200 /* filled buffer - remove self from polling */ 1201 if (stdinbufpos == BUFSIZE) 1202 pfd[POLL_STDIN].events = 0; 1203 } 1204 /* try to write to network */ 1205 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1206 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1207 &stdinbufpos, tls_ctx); 1208 if (ret == TLS_WANT_POLLIN) 1209 pfd[POLL_NETOUT].events = POLLIN; 1210 else if (ret == TLS_WANT_POLLOUT) 1211 pfd[POLL_NETOUT].events = POLLOUT; 1212 else if (ret == -1) 1213 pfd[POLL_NETOUT].fd = -1; 1214 /* buffer empty - remove self from polling */ 1215 if (stdinbufpos == 0) 1216 pfd[POLL_NETOUT].events = 0; 1217 /* buffer no longer full - poll stdin again */ 1218 if (stdinbufpos < BUFSIZE) 1219 pfd[POLL_STDIN].events = POLLIN; 1220 } 1221 /* try to read from network */ 1222 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1223 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1224 &netinbufpos, tls_ctx); 1225 if (ret == TLS_WANT_POLLIN) 1226 pfd[POLL_NETIN].events = POLLIN; 1227 else if (ret == TLS_WANT_POLLOUT) 1228 pfd[POLL_NETIN].events = POLLOUT; 1229 else if (ret == -1) 1230 pfd[POLL_NETIN].fd = -1; 1231 /* eof on net in - remove from pfd */ 1232 if (ret == 0) { 1233 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1234 pfd[POLL_NETIN].fd = -1; 1235 } 1236 if (recvlimit > 0 && ++recvcount >= recvlimit) { 1237 if (pfd[POLL_NETIN].fd != -1) 1238 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1239 pfd[POLL_NETIN].fd = -1; 1240 pfd[POLL_STDIN].fd = -1; 1241 } 1242 /* read something - poll stdout */ 1243 if (netinbufpos > 0) 1244 pfd[POLL_STDOUT].events = POLLOUT; 1245 /* filled buffer - remove self from polling */ 1246 if (netinbufpos == BUFSIZE) 1247 pfd[POLL_NETIN].events = 0; 1248 /* handle telnet */ 1249 if (tflag) 1250 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1251 netinbufpos); 1252 } 1253 /* try to write to stdout */ 1254 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1255 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1256 &netinbufpos, NULL); 1257 if (ret == TLS_WANT_POLLIN) 1258 pfd[POLL_STDOUT].events = POLLIN; 1259 else if (ret == TLS_WANT_POLLOUT) 1260 pfd[POLL_STDOUT].events = POLLOUT; 1261 else if (ret == -1) 1262 pfd[POLL_STDOUT].fd = -1; 1263 /* buffer empty - remove self from polling */ 1264 if (netinbufpos == 0) 1265 pfd[POLL_STDOUT].events = 0; 1266 /* buffer no longer full - poll net in again */ 1267 if (netinbufpos < BUFSIZE) 1268 pfd[POLL_NETIN].events = POLLIN; 1269 } 1270 1271 /* stdin gone and queue empty? */ 1272 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1273 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1274 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1275 pfd[POLL_NETOUT].fd = -1; 1276 } 1277 /* net in gone and queue empty? */ 1278 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1279 pfd[POLL_STDOUT].fd = -1; 1280 } 1281 } 1282 } 1283 1284 ssize_t 1285 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1286 { 1287 ssize_t n; 1288 ssize_t adjust; 1289 1290 if (tls) { 1291 n = tls_write(tls, buf, *bufpos); 1292 if (n == -1) 1293 errx(1, "tls write failed (%s)", tls_error(tls)); 1294 } else { 1295 n = write(fd, buf, *bufpos); 1296 /* don't treat EAGAIN, EINTR as error */ 1297 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1298 n = TLS_WANT_POLLOUT; 1299 } 1300 if (n <= 0) 1301 return n; 1302 /* adjust buffer */ 1303 adjust = *bufpos - n; 1304 if (adjust > 0) 1305 memmove(buf, buf + n, adjust); 1306 *bufpos -= n; 1307 return n; 1308 } 1309 1310 ssize_t 1311 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1312 { 1313 size_t num = BUFSIZE - *bufpos; 1314 ssize_t n; 1315 1316 if (tls) { 1317 n = tls_read(tls, buf + *bufpos, num); 1318 if (n == -1) 1319 errx(1, "tls read failed (%s)", tls_error(tls)); 1320 } else { 1321 n = read(fd, buf + *bufpos, num); 1322 /* don't treat EAGAIN, EINTR as error */ 1323 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1324 n = TLS_WANT_POLLIN; 1325 } 1326 if (n <= 0) 1327 return n; 1328 *bufpos += n; 1329 return n; 1330 } 1331 1332 /* 1333 * fdpass() 1334 * Pass the connected file descriptor to stdout and exit. 1335 */ 1336 void 1337 fdpass(int nfd) 1338 { 1339 struct msghdr mh; 1340 union { 1341 struct cmsghdr hdr; 1342 char buf[CMSG_SPACE(sizeof(int))]; 1343 } cmsgbuf; 1344 struct cmsghdr *cmsg; 1345 struct iovec iov; 1346 char c = '\0'; 1347 ssize_t r; 1348 struct pollfd pfd; 1349 1350 /* Avoid obvious stupidity */ 1351 if (isatty(STDOUT_FILENO)) 1352 errx(1, "Cannot pass file descriptor to tty"); 1353 1354 memset(&mh, 0, sizeof(mh)); 1355 memset(&cmsgbuf, 0, sizeof(cmsgbuf)); 1356 memset(&iov, 0, sizeof(iov)); 1357 1358 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1359 mh.msg_controllen = sizeof(cmsgbuf.buf); 1360 cmsg = CMSG_FIRSTHDR(&mh); 1361 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1362 cmsg->cmsg_level = SOL_SOCKET; 1363 cmsg->cmsg_type = SCM_RIGHTS; 1364 *(int *)CMSG_DATA(cmsg) = nfd; 1365 1366 iov.iov_base = &c; 1367 iov.iov_len = 1; 1368 mh.msg_iov = &iov; 1369 mh.msg_iovlen = 1; 1370 1371 memset(&pfd, 0, sizeof(pfd)); 1372 pfd.fd = STDOUT_FILENO; 1373 pfd.events = POLLOUT; 1374 for (;;) { 1375 r = sendmsg(STDOUT_FILENO, &mh, 0); 1376 if (r == -1) { 1377 if (errno == EAGAIN || errno == EINTR) { 1378 if (poll(&pfd, 1, -1) == -1) 1379 err(1, "poll"); 1380 continue; 1381 } 1382 err(1, "sendmsg"); 1383 } else if (r != 1) 1384 errx(1, "sendmsg: unexpected return value %zd", r); 1385 else 1386 break; 1387 } 1388 exit(0); 1389 } 1390 1391 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1392 void 1393 atelnet(int nfd, unsigned char *buf, unsigned int size) 1394 { 1395 unsigned char *p, *end; 1396 unsigned char obuf[4]; 1397 1398 if (size < 3) 1399 return; 1400 end = buf + size - 2; 1401 1402 for (p = buf; p < end; p++) { 1403 if (*p != IAC) 1404 continue; 1405 1406 obuf[0] = IAC; 1407 p++; 1408 if ((*p == WILL) || (*p == WONT)) 1409 obuf[1] = DONT; 1410 else if ((*p == DO) || (*p == DONT)) 1411 obuf[1] = WONT; 1412 else 1413 continue; 1414 1415 p++; 1416 obuf[2] = *p; 1417 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1418 warn("Write Error!"); 1419 } 1420 } 1421 1422 1423 int 1424 strtoport(char *portstr, int udp) 1425 { 1426 struct servent *entry; 1427 const char *errstr; 1428 char *proto; 1429 int port = -1; 1430 1431 proto = udp ? "udp" : "tcp"; 1432 1433 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1434 if (errstr == NULL) 1435 return port; 1436 if (errno != EINVAL) 1437 errx(1, "port number %s: %s", errstr, portstr); 1438 if ((entry = getservbyname(portstr, proto)) == NULL) 1439 errx(1, "service \"%s\" unknown", portstr); 1440 return ntohs(entry->s_port); 1441 } 1442 1443 /* 1444 * build_ports() 1445 * Build an array of ports in portlist[], listing each port 1446 * that we should try to connect to. 1447 */ 1448 void 1449 build_ports(char *p) 1450 { 1451 char *n; 1452 int hi, lo, cp; 1453 int x = 0; 1454 1455 if (isdigit((unsigned char)*p) && (n = strchr(p, '-')) != NULL) { 1456 *n = '\0'; 1457 n++; 1458 1459 /* Make sure the ports are in order: lowest->highest. */ 1460 hi = strtoport(n, uflag); 1461 lo = strtoport(p, uflag); 1462 if (lo > hi) { 1463 cp = hi; 1464 hi = lo; 1465 lo = cp; 1466 } 1467 1468 /* 1469 * Initialize portlist with a random permutation. Based on 1470 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1471 */ 1472 if (rflag) { 1473 for (x = 0; x <= hi - lo; x++) { 1474 cp = arc4random_uniform(x + 1); 1475 portlist[x] = portlist[cp]; 1476 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1477 err(1, "asprintf"); 1478 } 1479 } else { /* Load ports sequentially. */ 1480 for (cp = lo; cp <= hi; cp++) { 1481 if (asprintf(&portlist[x], "%d", cp) < 0) 1482 err(1, "asprintf"); 1483 x++; 1484 } 1485 } 1486 } else { 1487 char *tmp; 1488 1489 hi = strtoport(p, uflag); 1490 if (asprintf(&tmp, "%d", hi) != -1) 1491 portlist[0] = tmp; 1492 else 1493 err(1, NULL); 1494 } 1495 } 1496 1497 /* 1498 * udptest() 1499 * Do a few writes to see if the UDP port is there. 1500 * Fails once PF state table is full. 1501 */ 1502 int 1503 udptest(int s) 1504 { 1505 int i, ret; 1506 1507 for (i = 0; i <= 3; i++) { 1508 if (write(s, "X", 1) == 1) 1509 ret = 1; 1510 else 1511 ret = -1; 1512 } 1513 return ret; 1514 } 1515 1516 void 1517 set_common_sockopts(int s, int af) 1518 { 1519 int x = 1; 1520 1521 #ifdef TCP_MD5SIG 1522 if (Sflag) { 1523 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1524 &x, sizeof(x)) == -1) 1525 err(1, NULL); 1526 } 1527 #endif 1528 if (Dflag) { 1529 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1530 &x, sizeof(x)) == -1) 1531 err(1, NULL); 1532 } 1533 if (Tflag != -1) { 1534 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1535 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1536 err(1, "set IP ToS"); 1537 1538 #ifdef IPV6_TCLASS 1539 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1540 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1541 err(1, "set IPv6 traffic class"); 1542 #else 1543 else if (af == AF_INET6) { 1544 errno = ENOPROTOOPT; 1545 err(1, "set IPv6 traffic class not supported"); 1546 } 1547 #endif 1548 } 1549 if (Iflag) { 1550 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1551 &Iflag, sizeof(Iflag)) == -1) 1552 err(1, "set TCP receive buffer size"); 1553 } 1554 if (Oflag) { 1555 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1556 &Oflag, sizeof(Oflag)) == -1) 1557 err(1, "set TCP send buffer size"); 1558 } 1559 1560 if (ttl != -1) { 1561 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1562 IP_TTL, &ttl, sizeof(ttl))) 1563 err(1, "set IP TTL"); 1564 1565 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1566 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1567 err(1, "set IPv6 unicast hops"); 1568 } 1569 1570 if (minttl != -1) { 1571 #ifdef IP_MINTTL 1572 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1573 IP_MINTTL, &minttl, sizeof(minttl))) 1574 err(1, "set IP min TTL"); 1575 #endif 1576 1577 #ifdef IPV6_MINHOPCOUNT 1578 if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1579 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1580 err(1, "set IPv6 min hop count"); 1581 #endif 1582 } 1583 } 1584 1585 int 1586 process_tos_opt(char *s, int *val) 1587 { 1588 /* DiffServ Codepoints and other TOS mappings */ 1589 const struct toskeywords { 1590 const char *keyword; 1591 int val; 1592 } *t, toskeywords[] = { 1593 { "af11", IPTOS_DSCP_AF11 }, 1594 { "af12", IPTOS_DSCP_AF12 }, 1595 { "af13", IPTOS_DSCP_AF13 }, 1596 { "af21", IPTOS_DSCP_AF21 }, 1597 { "af22", IPTOS_DSCP_AF22 }, 1598 { "af23", IPTOS_DSCP_AF23 }, 1599 { "af31", IPTOS_DSCP_AF31 }, 1600 { "af32", IPTOS_DSCP_AF32 }, 1601 { "af33", IPTOS_DSCP_AF33 }, 1602 { "af41", IPTOS_DSCP_AF41 }, 1603 { "af42", IPTOS_DSCP_AF42 }, 1604 { "af43", IPTOS_DSCP_AF43 }, 1605 { "critical", IPTOS_PREC_CRITIC_ECP }, 1606 { "cs0", IPTOS_DSCP_CS0 }, 1607 { "cs1", IPTOS_DSCP_CS1 }, 1608 { "cs2", IPTOS_DSCP_CS2 }, 1609 { "cs3", IPTOS_DSCP_CS3 }, 1610 { "cs4", IPTOS_DSCP_CS4 }, 1611 { "cs5", IPTOS_DSCP_CS5 }, 1612 { "cs6", IPTOS_DSCP_CS6 }, 1613 { "cs7", IPTOS_DSCP_CS7 }, 1614 { "ef", IPTOS_DSCP_EF }, 1615 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1616 { "lowdelay", IPTOS_LOWDELAY }, 1617 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1618 { "reliability", IPTOS_RELIABILITY }, 1619 { "throughput", IPTOS_THROUGHPUT }, 1620 { NULL, -1 }, 1621 }; 1622 1623 for (t = toskeywords; t->keyword != NULL; t++) { 1624 if (strcmp(s, t->keyword) == 0) { 1625 *val = t->val; 1626 return 1; 1627 } 1628 } 1629 1630 return 0; 1631 } 1632 1633 int 1634 process_tls_opt(char *s, int *flags) 1635 { 1636 size_t len; 1637 char *v; 1638 1639 const struct tlskeywords { 1640 const char *keyword; 1641 int flag; 1642 char **value; 1643 } *t, tlskeywords[] = { 1644 { "ciphers", -1, &tls_ciphers }, 1645 { "clientcert", TLS_CCERT, NULL }, 1646 { "muststaple", TLS_MUSTSTAPLE, NULL }, 1647 { "noverify", TLS_NOVERIFY, NULL }, 1648 { "noname", TLS_NONAME, NULL }, 1649 { "protocols", -1, &tls_protocols }, 1650 { NULL, -1, NULL }, 1651 }; 1652 1653 len = strlen(s); 1654 if ((v = strchr(s, '=')) != NULL) { 1655 len = v - s; 1656 v++; 1657 } 1658 1659 for (t = tlskeywords; t->keyword != NULL; t++) { 1660 if (strlen(t->keyword) == len && 1661 strncmp(s, t->keyword, len) == 0) { 1662 if (t->value != NULL) { 1663 if (v == NULL) 1664 errx(1, "invalid tls value `%s'", s); 1665 *t->value = v; 1666 } else { 1667 *flags |= t->flag; 1668 } 1669 return 1; 1670 } 1671 } 1672 return 0; 1673 } 1674 1675 void 1676 save_peer_cert(struct tls *tls_ctx, FILE *fp) 1677 { 1678 const char *pem; 1679 size_t plen; 1680 1681 if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL) 1682 errx(1, "Can't get peer certificate"); 1683 if (fprintf(fp, "%.*s", (int)plen, pem) < 0) 1684 err(1, "unable to save peer cert"); 1685 if (fflush(fp) != 0) 1686 err(1, "unable to flush peer cert"); 1687 } 1688 1689 void 1690 report_tls(struct tls * tls_ctx, char * host) 1691 { 1692 time_t t; 1693 const char *ocsp_url; 1694 1695 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1696 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1697 fprintf(stderr, "Peer name: %s\n", 1698 tls_expectname ? tls_expectname : host); 1699 if (tls_peer_cert_subject(tls_ctx)) 1700 fprintf(stderr, "Subject: %s\n", 1701 tls_peer_cert_subject(tls_ctx)); 1702 if (tls_peer_cert_issuer(tls_ctx)) 1703 fprintf(stderr, "Issuer: %s\n", 1704 tls_peer_cert_issuer(tls_ctx)); 1705 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1706 fprintf(stderr, "Valid From: %s", ctime(&t)); 1707 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1708 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1709 if (tls_peer_cert_hash(tls_ctx)) 1710 fprintf(stderr, "Cert Hash: %s\n", 1711 tls_peer_cert_hash(tls_ctx)); 1712 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1713 if (ocsp_url != NULL) 1714 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1715 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1716 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1717 fprintf(stderr, "OCSP Stapling: %s\n", 1718 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1719 tls_peer_ocsp_result(tls_ctx)); 1720 fprintf(stderr, 1721 " response_status=%d cert_status=%d crl_reason=%d\n", 1722 tls_peer_ocsp_response_status(tls_ctx), 1723 tls_peer_ocsp_cert_status(tls_ctx), 1724 tls_peer_ocsp_crl_reason(tls_ctx)); 1725 t = tls_peer_ocsp_this_update(tls_ctx); 1726 fprintf(stderr, " this update: %s", 1727 t != -1 ? ctime(&t) : "\n"); 1728 t = tls_peer_ocsp_next_update(tls_ctx); 1729 fprintf(stderr, " next update: %s", 1730 t != -1 ? ctime(&t) : "\n"); 1731 t = tls_peer_ocsp_revocation_time(tls_ctx); 1732 fprintf(stderr, " revocation: %s", 1733 t != -1 ? ctime(&t) : "\n"); 1734 break; 1735 case -1: 1736 break; 1737 default: 1738 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1739 tls_peer_ocsp_response_status(tls_ctx), 1740 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1741 tls_peer_ocsp_result(tls_ctx)); 1742 break; 1743 1744 } 1745 } 1746 1747 void 1748 report_sock(const char *msg, const struct sockaddr *sa, socklen_t salen, 1749 char *path) 1750 { 1751 char host[NI_MAXHOST], port[NI_MAXSERV]; 1752 int herr; 1753 int flags = NI_NUMERICSERV; 1754 1755 if (path != NULL) { 1756 fprintf(stderr, "%s on %s\n", msg, path); 1757 return; 1758 } 1759 1760 if (nflag) 1761 flags |= NI_NUMERICHOST; 1762 1763 if ((herr = getnameinfo(sa, salen, host, sizeof(host), 1764 port, sizeof(port), flags)) != 0) { 1765 if (herr == EAI_SYSTEM) 1766 err(1, "getnameinfo"); 1767 else 1768 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1769 } 1770 1771 fprintf(stderr, "%s on %s %s\n", msg, host, port); 1772 } 1773 1774 void 1775 help(void) 1776 { 1777 usage(0); 1778 fprintf(stderr, "\tCommand Summary:\n\ 1779 \t-4 Use IPv4\n\ 1780 \t-6 Use IPv6\n\ 1781 \t-C certfile Public key file\n\ 1782 \t-c Use TLS\n\ 1783 \t-D Enable the debug socket option\n\ 1784 \t-d Detach from stdin\n\ 1785 \t-e name\t Required name in peer certificate\n\ 1786 \t-F Pass socket fd\n\ 1787 \t-H hash\t Hash string of peer certificate\n\ 1788 \t-h This help text\n\ 1789 \t-I length TCP receive buffer length\n\ 1790 \t-i interval Delay interval for lines sent, ports scanned\n\ 1791 \t-K keyfile Private key file\n\ 1792 \t-k Keep inbound sockets open for multiple connects\n\ 1793 \t-l Listen mode, for inbound connects\n\ 1794 \t-M ttl Outgoing TTL / Hop Limit\n\ 1795 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1796 \t-N Shutdown the network socket after EOF on stdin\n\ 1797 \t-n Suppress name/port resolutions\n\ 1798 \t-O length TCP send buffer length\n\ 1799 \t-o staplefile Staple file\n\ 1800 \t-P proxyuser\tUsername for proxy authentication\n\ 1801 \t-p port\t Specify local port for remote connects\n\ 1802 \t-R CAfile CA bundle\n\ 1803 \t-r Randomize remote ports\n" 1804 #ifdef TCP_MD5SIG 1805 "\ 1806 \t-S Enable the TCP MD5 signature option\n" 1807 #endif 1808 "\ 1809 \t-s source Local source address\n\ 1810 \t-T keyword TOS value or TLS options\n\ 1811 \t-t Answer TELNET negotiation\n\ 1812 \t-U Use UNIX domain socket\n\ 1813 \t-u UDP mode\n" 1814 #ifdef SO_RTABLE 1815 "\ 1816 \t-V rtable Specify alternate routing table\n" 1817 #endif 1818 "\ 1819 \t-v Verbose\n\ 1820 \t-W recvlimit Terminate after receiving a number of packets\n\ 1821 \t-w timeout Timeout for connects and final net reads\n\ 1822 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1823 \t-x addr[:port]\tSpecify proxy address and port\n\ 1824 \t-Z Peer certificate file\n\ 1825 \t-z Zero-I/O mode [used for scanning]\n\ 1826 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1827 exit(1); 1828 } 1829 1830 void 1831 usage(int ret) 1832 { 1833 fprintf(stderr, 1834 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1835 "[-H hash] [-I length]\n" 1836 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1837 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1838 "[-R CAfile]\n" 1839 "\t [-s source] [-T keyword] [-V rtable] [-W recvlimit] " 1840 "[-w timeout]\n" 1841 "\t [-X proxy_protocol] [-x proxy_address[:port]] " 1842 "[-Z peercertfile]\n" 1843 "\t [destination] [port]\n"); 1844 if (ret) 1845 exit(1); 1846 } 1847