1 /* $OpenBSD: netcat.c,v 1.217 2020/02/12 14:46:36 schwarze 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 #if !defined(OpenBSD) 63 #define pledge(request, paths) 0 64 #define unveil(path, permissions) 0 65 #endif 66 67 #define PORT_MAX 65535 68 #define UNIX_DG_TMP_SOCKET_SIZE 19 69 70 #define POLL_STDIN 0 71 #define POLL_NETOUT 1 72 #define POLL_NETIN 2 73 #define POLL_STDOUT 3 74 #define BUFSIZE 16384 75 76 #define TLS_NOVERIFY (1 << 1) 77 #define TLS_NONAME (1 << 2) 78 #define TLS_CCERT (1 << 3) 79 #define TLS_MUSTSTAPLE (1 << 4) 80 81 /* Command Line Options */ 82 int dflag; /* detached, no stdin */ 83 int Fflag; /* fdpass sock to stdout */ 84 unsigned int iflag; /* Interval Flag */ 85 int kflag; /* More than one connect */ 86 int lflag; /* Bind to local port */ 87 int Nflag; /* shutdown() network socket */ 88 int nflag; /* Don't do name look up */ 89 char *Pflag; /* Proxy username */ 90 char *pflag; /* Localport flag */ 91 int rflag; /* Random ports flag */ 92 char *sflag; /* Source Address */ 93 int tflag; /* Telnet Emulation */ 94 int uflag; /* UDP - Default to TCP */ 95 int vflag; /* Verbosity */ 96 int xflag; /* Socks proxy */ 97 int zflag; /* Port Scan Flag */ 98 int Dflag; /* sodebug */ 99 int Iflag; /* TCP receive buffer size */ 100 int Oflag; /* TCP send buffer size */ 101 #ifdef TCP_MD5SIG 102 int Sflag; /* TCP MD5 signature option */ 103 #endif 104 int Tflag = -1; /* IP Type of Service */ 105 #ifdef SO_RTABLE 106 int rtableid = -1; 107 #endif 108 109 int usetls; /* use TLS */ 110 const char *Cflag; /* Public cert file */ 111 const char *Kflag; /* Private key file */ 112 const char *oflag; /* OCSP stapling file */ 113 const char *Rflag; /* Root CA file */ 114 int tls_cachanged; /* Using non-default CA file */ 115 int TLSopt; /* TLS options */ 116 char *tls_expectname; /* required name in peer cert */ 117 char *tls_expecthash; /* required hash of peer cert */ 118 char *tls_ciphers; /* TLS ciphers */ 119 char *tls_protocols; /* TLS protocols */ 120 FILE *Zflag; /* file to save peer cert */ 121 122 int recvcount, recvlimit; 123 int timeout = -1; 124 int family = AF_UNSPEC; 125 char *portlist[PORT_MAX+1]; 126 char *unix_dg_tmp_socket; 127 int ttl = -1; 128 int minttl = -1; 129 130 void atelnet(int, unsigned char *, unsigned int); 131 int strtoport(char *portstr, int udp); 132 void build_ports(char *); 133 void help(void) __attribute__((noreturn)); 134 int local_listen(const char *, const char *, struct addrinfo); 135 void readwrite(int, struct tls *); 136 void fdpass(int nfd) __attribute__((noreturn)); 137 int remote_connect(const char *, const char *, struct addrinfo, char *); 138 int timeout_tls(int, struct tls *, int (*)(struct tls *)); 139 int timeout_connect(int, const struct sockaddr *, socklen_t); 140 int socks_connect(const char *, const char *, struct addrinfo, 141 const char *, const char *, struct addrinfo, int, const char *); 142 int udptest(int); 143 int unix_bind(char *, int); 144 int unix_connect(char *); 145 int unix_listen(char *); 146 void set_common_sockopts(int, int); 147 int process_tos_opt(char *, int *); 148 int process_tls_opt(char *, int *); 149 void save_peer_cert(struct tls *_tls_ctx, FILE *_fp); 150 void report_sock(const char *, const struct sockaddr *, socklen_t, char *); 151 void report_tls(struct tls *tls_ctx, char * host); 152 void usage(int); 153 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 154 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 155 void tls_setup_client(struct tls *, int, char *); 156 struct tls *tls_setup_server(struct tls *, int, char *); 157 158 int 159 main(int argc, char *argv[]) 160 { 161 int ch, s = -1, ret, socksv; 162 char *host, *uport; 163 char ipaddr[NI_MAXHOST]; 164 struct addrinfo hints; 165 struct servent *sv; 166 socklen_t len; 167 struct sockaddr_storage cliaddr; 168 char *proxy = NULL, *proxyport = NULL; 169 const char *errstr; 170 struct addrinfo proxyhints; 171 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 172 struct tls_config *tls_cfg = NULL; 173 struct tls *tls_ctx = NULL; 174 uint32_t protocols; 175 176 ret = 1; 177 socksv = 5; 178 host = NULL; 179 uport = NULL; 180 sv = NULL; 181 Rflag = tls_default_ca_cert_file(); 182 183 signal(SIGPIPE, SIG_IGN); 184 185 while ((ch = getopt(argc, argv, 186 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vW:w:X:x:Z:z")) 187 != -1) { 188 switch (ch) { 189 case '4': 190 family = AF_INET; 191 break; 192 case '6': 193 family = AF_INET6; 194 break; 195 case 'U': 196 family = AF_UNIX; 197 break; 198 case 'X': 199 if (strcasecmp(optarg, "connect") == 0) 200 socksv = -1; /* HTTP proxy CONNECT */ 201 else if (strcmp(optarg, "4") == 0) 202 socksv = 4; /* SOCKS v.4 */ 203 else if (strcmp(optarg, "5") == 0) 204 socksv = 5; /* SOCKS v.5 */ 205 else 206 errx(1, "unsupported proxy protocol"); 207 break; 208 case 'C': 209 Cflag = optarg; 210 break; 211 case 'c': 212 usetls = 1; 213 break; 214 case 'd': 215 dflag = 1; 216 break; 217 case 'e': 218 tls_expectname = optarg; 219 break; 220 case 'F': 221 Fflag = 1; 222 break; 223 case 'H': 224 tls_expecthash = optarg; 225 break; 226 case 'h': 227 help(); 228 break; 229 case 'i': 230 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 231 if (errstr) 232 errx(1, "interval %s: %s", errstr, optarg); 233 break; 234 case 'K': 235 Kflag = optarg; 236 break; 237 case 'k': 238 kflag = 1; 239 break; 240 case 'l': 241 lflag = 1; 242 break; 243 case 'M': 244 ttl = strtonum(optarg, 0, 255, &errstr); 245 if (errstr) 246 errx(1, "ttl is %s", errstr); 247 break; 248 case 'm': 249 minttl = strtonum(optarg, 0, 255, &errstr); 250 if (errstr) 251 errx(1, "minttl is %s", errstr); 252 break; 253 case 'N': 254 Nflag = 1; 255 break; 256 case 'n': 257 nflag = 1; 258 break; 259 case 'P': 260 Pflag = optarg; 261 break; 262 case 'p': 263 pflag = optarg; 264 break; 265 case 'R': 266 tls_cachanged = 1; 267 Rflag = optarg; 268 break; 269 case 'r': 270 rflag = 1; 271 break; 272 case 's': 273 sflag = optarg; 274 break; 275 case 't': 276 tflag = 1; 277 break; 278 case 'u': 279 uflag = 1; 280 break; 281 #ifdef SO_RTABLE 282 case 'V': 283 rtableid = (int)strtonum(optarg, 0, 284 RT_TABLEID_MAX, &errstr); 285 if (errstr) 286 errx(1, "rtable %s: %s", errstr, optarg); 287 break; 288 #endif 289 case 'v': 290 vflag = 1; 291 break; 292 case 'W': 293 recvlimit = strtonum(optarg, 1, INT_MAX, &errstr); 294 if (errstr) 295 errx(1, "receive limit %s: %s", errstr, optarg); 296 break; 297 case 'w': 298 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 299 if (errstr) 300 errx(1, "timeout %s: %s", errstr, optarg); 301 timeout *= 1000; 302 break; 303 case 'x': 304 xflag = 1; 305 if ((proxy = strdup(optarg)) == NULL) 306 err(1, NULL); 307 break; 308 case 'Z': 309 if (strcmp(optarg, "-") == 0) 310 Zflag = stderr; 311 else if ((Zflag = fopen(optarg, "w")) == NULL) 312 err(1, "can't open %s", optarg); 313 break; 314 case 'z': 315 zflag = 1; 316 break; 317 case 'D': 318 Dflag = 1; 319 break; 320 case 'I': 321 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 322 if (errstr != NULL) 323 errx(1, "TCP receive window %s: %s", 324 errstr, optarg); 325 break; 326 case 'O': 327 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 328 if (errstr != NULL) 329 errx(1, "TCP send window %s: %s", 330 errstr, optarg); 331 break; 332 case 'o': 333 oflag = optarg; 334 break; 335 #ifdef TCP_MD5SIG 336 case 'S': 337 Sflag = 1; 338 break; 339 #endif 340 case 'T': 341 errstr = NULL; 342 errno = 0; 343 if (process_tls_opt(optarg, &TLSopt)) 344 break; 345 if (process_tos_opt(optarg, &Tflag)) 346 break; 347 if (strlen(optarg) > 1 && optarg[0] == '0' && 348 optarg[1] == 'x') 349 Tflag = (int)strtol(optarg, NULL, 16); 350 else 351 Tflag = (int)strtonum(optarg, 0, 255, 352 &errstr); 353 if (Tflag < 0 || Tflag > 255 || errstr || errno) 354 errx(1, "illegal tos/tls value %s", optarg); 355 break; 356 default: 357 usage(1); 358 } 359 } 360 argc -= optind; 361 argv += optind; 362 363 #ifdef SO_RTABLE 364 if (rtableid >= 0) 365 if (setrtable(rtableid) == -1) 366 err(1, "setrtable"); 367 #endif 368 369 /* Cruft to make sure options are clean, and used properly. */ 370 if (argc == 1 && family == AF_UNIX) { 371 host = argv[0]; 372 } else if (argc == 1 && lflag) { 373 uport = argv[0]; 374 } else if (argc == 2) { 375 host = argv[0]; 376 uport = argv[1]; 377 } else 378 usage(1); 379 380 if (usetls) { 381 if (Cflag && unveil(Cflag, "r") == -1) 382 err(1, "unveil"); 383 if (unveil(Rflag, "r") == -1) 384 err(1, "unveil"); 385 if (Kflag && unveil(Kflag, "r") == -1) 386 err(1, "unveil"); 387 if (oflag && unveil(oflag, "r") == -1) 388 err(1, "unveil"); 389 } else if (family == AF_UNIX && uflag && lflag && !kflag) { 390 /* 391 * After recvfrom(2) from client, the server connects 392 * to the client socket. As the client path is determined 393 * during runtime, we cannot unveil(2). 394 */ 395 } else { 396 if (family == AF_UNIX) { 397 if (unveil(host, "rwc") == -1) 398 err(1, "unveil"); 399 if (uflag && !kflag) { 400 if (sflag) { 401 if (unveil(sflag, "rwc") == -1) 402 err(1, "unveil"); 403 } else { 404 if (unveil("/tmp", "rwc") == -1) 405 err(1, "unveil"); 406 } 407 } 408 } else { 409 /* no filesystem visibility */ 410 if (unveil("/", "") == -1) 411 err(1, "unveil"); 412 } 413 } 414 415 if (family == AF_UNIX) { 416 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 417 err(1, "pledge"); 418 } else if (Fflag && Pflag) { 419 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 420 err(1, "pledge"); 421 } else if (Fflag) { 422 if (pledge("stdio inet dns sendfd", NULL) == -1) 423 err(1, "pledge"); 424 } else if (Pflag && usetls) { 425 if (pledge("stdio rpath inet dns tty", NULL) == -1) 426 err(1, "pledge"); 427 } else if (Pflag) { 428 if (pledge("stdio inet dns tty", NULL) == -1) 429 err(1, "pledge"); 430 } else if (usetls) { 431 if (pledge("stdio rpath inet dns", NULL) == -1) 432 err(1, "pledge"); 433 } else if (pledge("stdio inet dns", NULL) == -1) 434 err(1, "pledge"); 435 436 if (lflag && sflag) 437 errx(1, "cannot use -s and -l"); 438 if (lflag && pflag) 439 errx(1, "cannot use -p and -l"); 440 if (lflag && zflag) 441 errx(1, "cannot use -z and -l"); 442 if (!lflag && kflag) 443 errx(1, "must use -l with -k"); 444 if (uflag && usetls) 445 errx(1, "cannot use -c and -u"); 446 if ((family == AF_UNIX) && usetls) 447 errx(1, "cannot use -c and -U"); 448 if ((family == AF_UNIX) && Fflag) 449 errx(1, "cannot use -F and -U"); 450 if (Fflag && usetls) 451 errx(1, "cannot use -c and -F"); 452 if (TLSopt && !usetls) 453 errx(1, "you must specify -c to use TLS options"); 454 if (Cflag && !usetls) 455 errx(1, "you must specify -c to use -C"); 456 if (Kflag && !usetls) 457 errx(1, "you must specify -c to use -K"); 458 if (Zflag && !usetls) 459 errx(1, "you must specify -c to use -Z"); 460 if (oflag && !Cflag) 461 errx(1, "you must specify -C to use -o"); 462 if (tls_cachanged && !usetls) 463 errx(1, "you must specify -c to use -R"); 464 if (tls_expecthash && !usetls) 465 errx(1, "you must specify -c to use -H"); 466 if (tls_expectname && !usetls) 467 errx(1, "you must specify -c to use -e"); 468 469 /* Get name of temporary socket for unix datagram client */ 470 if ((family == AF_UNIX) && uflag && !lflag) { 471 if (sflag) { 472 unix_dg_tmp_socket = sflag; 473 } else { 474 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 475 UNIX_DG_TMP_SOCKET_SIZE); 476 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 477 err(1, "mktemp"); 478 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 479 } 480 } 481 482 /* Initialize addrinfo structure. */ 483 if (family != AF_UNIX) { 484 memset(&hints, 0, sizeof(struct addrinfo)); 485 hints.ai_family = family; 486 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 487 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 488 if (nflag) 489 hints.ai_flags |= AI_NUMERICHOST; 490 } 491 492 if (xflag) { 493 if (uflag) 494 errx(1, "no proxy support for UDP mode"); 495 496 if (lflag) 497 errx(1, "no proxy support for listen"); 498 499 if (family == AF_UNIX) 500 errx(1, "no proxy support for unix sockets"); 501 502 if (sflag) 503 errx(1, "no proxy support for local source address"); 504 505 if (*proxy == '[') { 506 ++proxy; 507 proxyport = strchr(proxy, ']'); 508 if (proxyport == NULL) 509 errx(1, "missing closing bracket in proxy"); 510 *proxyport++ = '\0'; 511 if (*proxyport == '\0') 512 /* Use default proxy port. */ 513 proxyport = NULL; 514 else { 515 if (*proxyport == ':') 516 ++proxyport; 517 else 518 errx(1, "garbage proxy port delimiter"); 519 } 520 } else { 521 proxyport = strrchr(proxy, ':'); 522 if (proxyport != NULL) 523 *proxyport++ = '\0'; 524 } 525 526 memset(&proxyhints, 0, sizeof(struct addrinfo)); 527 proxyhints.ai_family = family; 528 proxyhints.ai_socktype = SOCK_STREAM; 529 proxyhints.ai_protocol = IPPROTO_TCP; 530 if (nflag) 531 proxyhints.ai_flags |= AI_NUMERICHOST; 532 } 533 534 if (usetls) { 535 if ((tls_cfg = tls_config_new()) == NULL) 536 errx(1, "unable to allocate TLS config"); 537 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 538 errx(1, "%s", tls_config_error(tls_cfg)); 539 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 540 errx(1, "%s", tls_config_error(tls_cfg)); 541 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 542 errx(1, "%s", tls_config_error(tls_cfg)); 543 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 544 errx(1, "%s", tls_config_error(tls_cfg)); 545 if (tls_config_parse_protocols(&protocols, tls_protocols) == -1) 546 errx(1, "invalid TLS protocols `%s'", tls_protocols); 547 if (tls_config_set_protocols(tls_cfg, protocols) == -1) 548 errx(1, "%s", tls_config_error(tls_cfg)); 549 if (tls_config_set_ciphers(tls_cfg, tls_ciphers) == -1) 550 errx(1, "%s", tls_config_error(tls_cfg)); 551 if (!lflag && (TLSopt & TLS_CCERT)) 552 errx(1, "clientcert is only valid with -l"); 553 if (TLSopt & TLS_NONAME) 554 tls_config_insecure_noverifyname(tls_cfg); 555 if (TLSopt & TLS_NOVERIFY) { 556 if (tls_expecthash != NULL) 557 errx(1, "-H and -T noverify may not be used " 558 "together"); 559 tls_config_insecure_noverifycert(tls_cfg); 560 } 561 if (TLSopt & TLS_MUSTSTAPLE) 562 tls_config_ocsp_require_stapling(tls_cfg); 563 564 if (Pflag) { 565 if (pledge("stdio inet dns tty", NULL) == -1) 566 err(1, "pledge"); 567 } else if (pledge("stdio inet dns", NULL) == -1) 568 err(1, "pledge"); 569 } 570 if (lflag) { 571 ret = 0; 572 573 if (family == AF_UNIX) { 574 if (uflag) 575 s = unix_bind(host, 0); 576 else 577 s = unix_listen(host); 578 } 579 580 if (usetls) { 581 tls_config_verify_client_optional(tls_cfg); 582 if ((tls_ctx = tls_server()) == NULL) 583 errx(1, "tls server creation failed"); 584 if (tls_configure(tls_ctx, tls_cfg) == -1) 585 errx(1, "tls configuration failed (%s)", 586 tls_error(tls_ctx)); 587 } 588 /* Allow only one connection at a time, but stay alive. */ 589 for (;;) { 590 if (family != AF_UNIX) { 591 if (s != -1) 592 close(s); 593 s = local_listen(host, uport, hints); 594 } 595 if (s == -1) 596 err(1, NULL); 597 if (uflag && kflag) { 598 if (family == AF_UNIX) { 599 if (pledge("stdio unix", NULL) == -1) 600 err(1, "pledge"); 601 } 602 /* 603 * For UDP and -k, don't connect the socket, 604 * let it receive datagrams from multiple 605 * socket pairs. 606 */ 607 readwrite(s, NULL); 608 } else if (uflag && !kflag) { 609 /* 610 * For UDP and not -k, we will use recvfrom() 611 * initially to wait for a caller, then use 612 * the regular functions to talk to the caller. 613 */ 614 int rv; 615 char buf[2048]; 616 struct sockaddr_storage z; 617 618 len = sizeof(z); 619 rv = recvfrom(s, buf, sizeof(buf), MSG_PEEK, 620 (struct sockaddr *)&z, &len); 621 if (rv == -1) 622 err(1, "recvfrom"); 623 624 rv = connect(s, (struct sockaddr *)&z, len); 625 if (rv == -1) 626 err(1, "connect"); 627 628 if (family == AF_UNIX) { 629 if (pledge("stdio unix", NULL) == -1) 630 err(1, "pledge"); 631 } 632 if (vflag) 633 report_sock("Connection received", 634 (struct sockaddr *)&z, len, 635 family == AF_UNIX ? host : NULL); 636 637 readwrite(s, NULL); 638 } else { 639 struct tls *tls_cctx = NULL; 640 int connfd; 641 642 len = sizeof(cliaddr); 643 connfd = accept4(s, (struct sockaddr *)&cliaddr, 644 &len, SOCK_NONBLOCK); 645 if (connfd == -1) { 646 /* For now, all errnos are fatal */ 647 err(1, "accept"); 648 } 649 if (vflag) 650 report_sock("Connection received", 651 (struct sockaddr *)&cliaddr, len, 652 family == AF_UNIX ? host : NULL); 653 if ((usetls) && 654 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 655 readwrite(connfd, tls_cctx); 656 if (!usetls) 657 readwrite(connfd, NULL); 658 if (tls_cctx) 659 timeout_tls(s, tls_cctx, tls_close); 660 close(connfd); 661 tls_free(tls_cctx); 662 } 663 if (family == AF_UNIX && uflag) { 664 if (connect(s, NULL, 0) == -1) 665 err(1, "connect"); 666 } 667 668 if (!kflag) 669 break; 670 } 671 } else if (family == AF_UNIX) { 672 ret = 0; 673 674 if ((s = unix_connect(host)) > 0) { 675 if (!zflag) 676 readwrite(s, NULL); 677 close(s); 678 } else { 679 warn("%s", host); 680 ret = 1; 681 } 682 683 if (uflag) 684 unlink(unix_dg_tmp_socket); 685 return ret; 686 687 } else { 688 int i = 0; 689 690 /* Construct the portlist[] array. */ 691 build_ports(uport); 692 693 /* Cycle through portlist, connecting to each port. */ 694 for (s = -1, i = 0; portlist[i] != NULL; i++) { 695 if (s != -1) 696 close(s); 697 tls_free(tls_ctx); 698 tls_ctx = NULL; 699 700 if (usetls) { 701 if ((tls_ctx = tls_client()) == NULL) 702 errx(1, "tls client creation failed"); 703 if (tls_configure(tls_ctx, tls_cfg) == -1) 704 errx(1, "tls configuration failed (%s)", 705 tls_error(tls_ctx)); 706 } 707 if (xflag) 708 s = socks_connect(host, portlist[i], hints, 709 proxy, proxyport, proxyhints, socksv, 710 Pflag); 711 else 712 s = remote_connect(host, portlist[i], hints, 713 ipaddr); 714 715 if (s == -1) 716 continue; 717 718 ret = 0; 719 if (vflag || zflag) { 720 /* For UDP, make sure we are connected. */ 721 if (uflag) { 722 if (udptest(s) == -1) { 723 ret = 1; 724 continue; 725 } 726 } 727 728 /* Don't look up port if -n. */ 729 if (nflag) 730 sv = NULL; 731 else { 732 sv = getservbyport( 733 ntohs(atoi(portlist[i])), 734 uflag ? "udp" : "tcp"); 735 } 736 737 fprintf(stderr, "Connection to %s", host); 738 739 /* 740 * if we aren't connecting thru a proxy and 741 * there is something to report, print IP 742 */ 743 if (!nflag && !xflag 744 && (strcmp(host, ipaddr) != 0)) 745 fprintf(stderr, " (%s)", ipaddr); 746 747 fprintf(stderr, " %s port [%s/%s] succeeded!\n", 748 portlist[i], uflag ? "udp" : "tcp", 749 sv ? sv->s_name : "*"); 750 } 751 if (Fflag) 752 fdpass(s); 753 else { 754 if (usetls) 755 tls_setup_client(tls_ctx, s, host); 756 if (!zflag) 757 readwrite(s, tls_ctx); 758 if (tls_ctx) 759 timeout_tls(s, tls_ctx, tls_close); 760 } 761 } 762 } 763 764 if (s != -1) 765 close(s); 766 tls_free(tls_ctx); 767 tls_config_free(tls_cfg); 768 769 return ret; 770 } 771 772 /* 773 * unix_bind() 774 * Returns a unix socket bound to the given path 775 */ 776 int 777 unix_bind(char *path, int flags) 778 { 779 struct sockaddr_un s_un; 780 int s, save_errno; 781 782 /* Create unix domain socket. */ 783 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 784 0)) == -1) 785 return -1; 786 787 memset(&s_un, 0, sizeof(struct sockaddr_un)); 788 s_un.sun_family = AF_UNIX; 789 790 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 791 sizeof(s_un.sun_path)) { 792 close(s); 793 errno = ENAMETOOLONG; 794 return -1; 795 } 796 797 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { 798 save_errno = errno; 799 close(s); 800 errno = save_errno; 801 return -1; 802 } 803 if (vflag) 804 report_sock("Bound", NULL, 0, path); 805 806 return s; 807 } 808 809 int 810 timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) 811 { 812 struct pollfd pfd; 813 int ret; 814 815 while ((ret = (*func)(tls_ctx)) != 0) { 816 if (ret == TLS_WANT_POLLIN) 817 pfd.events = POLLIN; 818 else if (ret == TLS_WANT_POLLOUT) 819 pfd.events = POLLOUT; 820 else 821 break; 822 pfd.fd = s; 823 if ((ret = poll(&pfd, 1, timeout)) == 1) 824 continue; 825 else if (ret == 0) { 826 errno = ETIMEDOUT; 827 ret = -1; 828 break; 829 } else 830 err(1, "poll failed"); 831 } 832 833 return ret; 834 } 835 836 void 837 tls_setup_client(struct tls *tls_ctx, int s, char *host) 838 { 839 const char *errstr; 840 841 if (tls_connect_socket(tls_ctx, s, 842 tls_expectname ? tls_expectname : host) == -1) { 843 errx(1, "tls connection failed (%s)", 844 tls_error(tls_ctx)); 845 } 846 if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { 847 if ((errstr = tls_error(tls_ctx)) == NULL) 848 errstr = strerror(errno); 849 errx(1, "tls handshake failed (%s)", errstr); 850 } 851 if (vflag) 852 report_tls(tls_ctx, host); 853 if (tls_expecthash && (tls_peer_cert_hash(tls_ctx) == NULL || 854 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0)) 855 errx(1, "peer certificate is not %s", tls_expecthash); 856 if (Zflag) { 857 save_peer_cert(tls_ctx, Zflag); 858 if (Zflag != stderr && (fclose(Zflag) != 0)) 859 err(1, "fclose failed saving peer cert"); 860 } 861 } 862 863 struct tls * 864 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 865 { 866 struct tls *tls_cctx; 867 const char *errstr; 868 869 if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { 870 warnx("tls accept failed (%s)", tls_error(tls_ctx)); 871 } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { 872 if ((errstr = tls_error(tls_cctx)) == NULL) 873 errstr = strerror(errno); 874 warnx("tls handshake failed (%s)", errstr); 875 } else { 876 int gotcert = tls_peer_cert_provided(tls_cctx); 877 878 if (vflag && gotcert) 879 report_tls(tls_cctx, host); 880 if ((TLSopt & TLS_CCERT) && !gotcert) 881 warnx("No client certificate provided"); 882 else if (gotcert && tls_expecthash && 883 (tls_peer_cert_hash(tls_cctx) == NULL || 884 strcmp(tls_expecthash, tls_peer_cert_hash(tls_cctx)) != 0)) 885 warnx("peer certificate is not %s", tls_expecthash); 886 else if (gotcert && tls_expectname && 887 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 888 warnx("name (%s) not found in client cert", 889 tls_expectname); 890 else { 891 return tls_cctx; 892 } 893 } 894 return NULL; 895 } 896 897 /* 898 * unix_connect() 899 * Returns a socket connected to a local unix socket. Returns -1 on failure. 900 */ 901 int 902 unix_connect(char *path) 903 { 904 struct sockaddr_un s_un; 905 int s, save_errno; 906 907 if (uflag) { 908 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) == -1) 909 return -1; 910 } else { 911 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) == -1) 912 return -1; 913 } 914 915 memset(&s_un, 0, sizeof(struct sockaddr_un)); 916 s_un.sun_family = AF_UNIX; 917 918 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 919 sizeof(s_un.sun_path)) { 920 close(s); 921 errno = ENAMETOOLONG; 922 return -1; 923 } 924 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) == -1) { 925 save_errno = errno; 926 close(s); 927 errno = save_errno; 928 return -1; 929 } 930 return s; 931 932 } 933 934 /* 935 * unix_listen() 936 * Create a unix domain socket, and listen on it. 937 */ 938 int 939 unix_listen(char *path) 940 { 941 int s; 942 943 if ((s = unix_bind(path, 0)) == -1) 944 return -1; 945 if (listen(s, 5) == -1) { 946 close(s); 947 return -1; 948 } 949 if (vflag) 950 report_sock("Listening", NULL, 0, path); 951 952 return s; 953 } 954 955 /* 956 * remote_connect() 957 * Returns a socket connected to a remote host. Properly binds to a local 958 * port or source address if needed. Returns -1 on failure. 959 */ 960 int 961 remote_connect(const char *host, const char *port, struct addrinfo hints, 962 char *ipaddr) 963 { 964 struct addrinfo *res, *res0; 965 int s = -1, error, herr, save_errno; 966 #ifdef SO_BINDANY 967 int on = 1; 968 #endif 969 970 if ((error = getaddrinfo(host, port, &hints, &res0))) 971 errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, 972 port, gai_strerror(error)); 973 974 for (res = res0; res; res = res->ai_next) { 975 if ((s = socket(res->ai_family, res->ai_socktype | 976 SOCK_NONBLOCK, res->ai_protocol)) == -1) 977 continue; 978 979 /* Bind to a local port or source address if specified. */ 980 if (sflag || pflag) { 981 struct addrinfo ahints, *ares; 982 983 #ifdef SO_BINDANY 984 /* try SO_BINDANY, but don't insist */ 985 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 986 #endif 987 memset(&ahints, 0, sizeof(struct addrinfo)); 988 ahints.ai_family = res->ai_family; 989 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 990 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 991 ahints.ai_flags = AI_PASSIVE; 992 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 993 errx(1, "getaddrinfo: %s", gai_strerror(error)); 994 995 if (bind(s, (struct sockaddr *)ares->ai_addr, 996 ares->ai_addrlen) == -1) 997 err(1, "bind failed"); 998 freeaddrinfo(ares); 999 } 1000 1001 set_common_sockopts(s, res->ai_family); 1002 1003 if (ipaddr != NULL) { 1004 herr = getnameinfo(res->ai_addr, res->ai_addrlen, 1005 ipaddr, NI_MAXHOST, NULL, 0, NI_NUMERICHOST); 1006 switch (herr) { 1007 case 0: 1008 break; 1009 case EAI_SYSTEM: 1010 err(1, "getnameinfo"); 1011 default: 1012 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1013 } 1014 } 1015 1016 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 1017 break; 1018 1019 if (vflag) { 1020 /* only print IP if there is something to report */ 1021 if (nflag || ipaddr == NULL || 1022 (strncmp(host, ipaddr, NI_MAXHOST) == 0)) 1023 warn("connect to %s port %s (%s) failed", host, 1024 port, uflag ? "udp" : "tcp"); 1025 else 1026 warn("connect to %s (%s) port %s (%s) failed", 1027 host, ipaddr, port, uflag ? "udp" : "tcp"); 1028 } 1029 1030 save_errno = errno; 1031 close(s); 1032 errno = save_errno; 1033 s = -1; 1034 } 1035 1036 freeaddrinfo(res0); 1037 1038 return s; 1039 } 1040 1041 int 1042 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 1043 { 1044 struct pollfd pfd; 1045 socklen_t optlen; 1046 int optval; 1047 int ret; 1048 1049 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 1050 pfd.fd = s; 1051 pfd.events = POLLOUT; 1052 if ((ret = poll(&pfd, 1, timeout)) == 1) { 1053 optlen = sizeof(optval); 1054 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 1055 &optval, &optlen)) == 0) { 1056 errno = optval; 1057 ret = optval == 0 ? 0 : -1; 1058 } 1059 } else if (ret == 0) { 1060 errno = ETIMEDOUT; 1061 ret = -1; 1062 } else 1063 err(1, "poll failed"); 1064 } 1065 1066 return ret; 1067 } 1068 1069 /* 1070 * local_listen() 1071 * Returns a socket listening on a local port, binds to specified source 1072 * address. Returns -1 on failure. 1073 */ 1074 int 1075 local_listen(const char *host, const char *port, struct addrinfo hints) 1076 { 1077 struct addrinfo *res, *res0; 1078 int s = -1, save_errno; 1079 #ifdef SO_REUSEPORT 1080 int ret, x = 1; 1081 #endif 1082 int error; 1083 1084 /* Allow nodename to be null. */ 1085 hints.ai_flags |= AI_PASSIVE; 1086 1087 /* 1088 * In the case of binding to a wildcard address 1089 * default to binding to an ipv4 address. 1090 */ 1091 if (host == NULL && hints.ai_family == AF_UNSPEC) 1092 hints.ai_family = AF_INET; 1093 1094 if ((error = getaddrinfo(host, port, &hints, &res0))) 1095 errx(1, "getaddrinfo: %s", gai_strerror(error)); 1096 1097 for (res = res0; res; res = res->ai_next) { 1098 if ((s = socket(res->ai_family, res->ai_socktype, 1099 res->ai_protocol)) == -1) 1100 continue; 1101 1102 #ifdef SO_REUSEPORT 1103 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 1104 if (ret == -1) 1105 err(1, NULL); 1106 #endif 1107 1108 set_common_sockopts(s, res->ai_family); 1109 1110 if (bind(s, (struct sockaddr *)res->ai_addr, 1111 res->ai_addrlen) == 0) 1112 break; 1113 1114 save_errno = errno; 1115 close(s); 1116 errno = save_errno; 1117 s = -1; 1118 } 1119 1120 if (!uflag && s != -1) { 1121 if (listen(s, 1) == -1) 1122 err(1, "listen"); 1123 } 1124 if (vflag && s != -1) { 1125 struct sockaddr_storage ss; 1126 socklen_t len; 1127 1128 len = sizeof(ss); 1129 if (getsockname(s, (struct sockaddr *)&ss, &len) == -1) 1130 err(1, "getsockname"); 1131 report_sock(uflag ? "Bound" : "Listening", 1132 (struct sockaddr *)&ss, len, NULL); 1133 } 1134 1135 freeaddrinfo(res0); 1136 1137 return s; 1138 } 1139 1140 /* 1141 * readwrite() 1142 * Loop that polls on the network file descriptor and stdin. 1143 */ 1144 void 1145 readwrite(int net_fd, struct tls *tls_ctx) 1146 { 1147 struct pollfd pfd[4]; 1148 int stdin_fd = STDIN_FILENO; 1149 int stdout_fd = STDOUT_FILENO; 1150 unsigned char netinbuf[BUFSIZE]; 1151 size_t netinbufpos = 0; 1152 unsigned char stdinbuf[BUFSIZE]; 1153 size_t stdinbufpos = 0; 1154 int n, num_fds; 1155 ssize_t ret; 1156 1157 /* don't read from stdin if requested */ 1158 if (dflag) 1159 stdin_fd = -1; 1160 1161 /* stdin */ 1162 pfd[POLL_STDIN].fd = stdin_fd; 1163 pfd[POLL_STDIN].events = POLLIN; 1164 1165 /* network out */ 1166 pfd[POLL_NETOUT].fd = net_fd; 1167 pfd[POLL_NETOUT].events = 0; 1168 1169 /* network in */ 1170 pfd[POLL_NETIN].fd = net_fd; 1171 pfd[POLL_NETIN].events = POLLIN; 1172 1173 /* stdout */ 1174 pfd[POLL_STDOUT].fd = stdout_fd; 1175 pfd[POLL_STDOUT].events = 0; 1176 1177 while (1) { 1178 /* both inputs are gone, buffers are empty, we are done */ 1179 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1180 stdinbufpos == 0 && netinbufpos == 0) 1181 return; 1182 /* both outputs are gone, we can't continue */ 1183 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) 1184 return; 1185 /* listen and net in gone, queues empty, done */ 1186 if (lflag && pfd[POLL_NETIN].fd == -1 && 1187 stdinbufpos == 0 && netinbufpos == 0) 1188 return; 1189 1190 /* help says -i is for "wait between lines sent". We read and 1191 * write arbitrary amounts of data, and we don't want to start 1192 * scanning for newlines, so this is as good as it gets */ 1193 if (iflag) 1194 sleep(iflag); 1195 1196 /* poll */ 1197 num_fds = poll(pfd, 4, timeout); 1198 1199 /* treat poll errors */ 1200 if (num_fds == -1) 1201 err(1, "polling error"); 1202 1203 /* timeout happened */ 1204 if (num_fds == 0) 1205 return; 1206 1207 /* treat socket error conditions */ 1208 for (n = 0; n < 4; n++) { 1209 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1210 pfd[n].fd = -1; 1211 } 1212 } 1213 /* reading is possible after HUP */ 1214 if (pfd[POLL_STDIN].events & POLLIN && 1215 pfd[POLL_STDIN].revents & POLLHUP && 1216 !(pfd[POLL_STDIN].revents & POLLIN)) 1217 pfd[POLL_STDIN].fd = -1; 1218 1219 if (pfd[POLL_NETIN].events & POLLIN && 1220 pfd[POLL_NETIN].revents & POLLHUP && 1221 !(pfd[POLL_NETIN].revents & POLLIN)) 1222 pfd[POLL_NETIN].fd = -1; 1223 1224 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1225 if (Nflag) 1226 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1227 pfd[POLL_NETOUT].fd = -1; 1228 } 1229 /* if HUP, stop watching stdout */ 1230 if (pfd[POLL_STDOUT].revents & POLLHUP) 1231 pfd[POLL_STDOUT].fd = -1; 1232 /* if no net out, stop watching stdin */ 1233 if (pfd[POLL_NETOUT].fd == -1) 1234 pfd[POLL_STDIN].fd = -1; 1235 /* if no stdout, stop watching net in */ 1236 if (pfd[POLL_STDOUT].fd == -1) { 1237 if (pfd[POLL_NETIN].fd != -1) 1238 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1239 pfd[POLL_NETIN].fd = -1; 1240 } 1241 1242 /* try to read from stdin */ 1243 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1244 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1245 &stdinbufpos, NULL); 1246 if (ret == TLS_WANT_POLLIN) 1247 pfd[POLL_STDIN].events = POLLIN; 1248 else if (ret == TLS_WANT_POLLOUT) 1249 pfd[POLL_STDIN].events = POLLOUT; 1250 else if (ret == 0 || ret == -1) 1251 pfd[POLL_STDIN].fd = -1; 1252 /* read something - poll net out */ 1253 if (stdinbufpos > 0) 1254 pfd[POLL_NETOUT].events = POLLOUT; 1255 /* filled buffer - remove self from polling */ 1256 if (stdinbufpos == BUFSIZE) 1257 pfd[POLL_STDIN].events = 0; 1258 } 1259 /* try to write to network */ 1260 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1261 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1262 &stdinbufpos, tls_ctx); 1263 if (ret == TLS_WANT_POLLIN) 1264 pfd[POLL_NETOUT].events = POLLIN; 1265 else if (ret == TLS_WANT_POLLOUT) 1266 pfd[POLL_NETOUT].events = POLLOUT; 1267 else if (ret == -1) 1268 pfd[POLL_NETOUT].fd = -1; 1269 /* buffer empty - remove self from polling */ 1270 if (stdinbufpos == 0) 1271 pfd[POLL_NETOUT].events = 0; 1272 /* buffer no longer full - poll stdin again */ 1273 if (stdinbufpos < BUFSIZE) 1274 pfd[POLL_STDIN].events = POLLIN; 1275 } 1276 /* try to read from network */ 1277 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1278 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1279 &netinbufpos, tls_ctx); 1280 if (ret == TLS_WANT_POLLIN) 1281 pfd[POLL_NETIN].events = POLLIN; 1282 else if (ret == TLS_WANT_POLLOUT) 1283 pfd[POLL_NETIN].events = POLLOUT; 1284 else if (ret == -1) 1285 pfd[POLL_NETIN].fd = -1; 1286 /* eof on net in - remove from pfd */ 1287 if (ret == 0) { 1288 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1289 pfd[POLL_NETIN].fd = -1; 1290 } 1291 if (recvlimit > 0 && ++recvcount >= recvlimit) { 1292 if (pfd[POLL_NETIN].fd != -1) 1293 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1294 pfd[POLL_NETIN].fd = -1; 1295 pfd[POLL_STDIN].fd = -1; 1296 } 1297 /* read something - poll stdout */ 1298 if (netinbufpos > 0) 1299 pfd[POLL_STDOUT].events = POLLOUT; 1300 /* filled buffer - remove self from polling */ 1301 if (netinbufpos == BUFSIZE) 1302 pfd[POLL_NETIN].events = 0; 1303 /* handle telnet */ 1304 if (tflag) 1305 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1306 netinbufpos); 1307 } 1308 /* try to write to stdout */ 1309 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1310 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1311 &netinbufpos, NULL); 1312 if (ret == TLS_WANT_POLLIN) 1313 pfd[POLL_STDOUT].events = POLLIN; 1314 else if (ret == TLS_WANT_POLLOUT) 1315 pfd[POLL_STDOUT].events = POLLOUT; 1316 else if (ret == -1) 1317 pfd[POLL_STDOUT].fd = -1; 1318 /* buffer empty - remove self from polling */ 1319 if (netinbufpos == 0) 1320 pfd[POLL_STDOUT].events = 0; 1321 /* buffer no longer full - poll net in again */ 1322 if (netinbufpos < BUFSIZE) 1323 pfd[POLL_NETIN].events = POLLIN; 1324 } 1325 1326 /* stdin gone and queue empty? */ 1327 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1328 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1329 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1330 pfd[POLL_NETOUT].fd = -1; 1331 } 1332 /* net in gone and queue empty? */ 1333 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1334 pfd[POLL_STDOUT].fd = -1; 1335 } 1336 } 1337 } 1338 1339 ssize_t 1340 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1341 { 1342 ssize_t n; 1343 ssize_t adjust; 1344 1345 if (tls) { 1346 n = tls_write(tls, buf, *bufpos); 1347 if (n == -1) 1348 errx(1, "tls write failed (%s)", tls_error(tls)); 1349 } else { 1350 n = write(fd, buf, *bufpos); 1351 /* don't treat EAGAIN, EINTR as error */ 1352 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1353 n = TLS_WANT_POLLOUT; 1354 } 1355 if (n <= 0) 1356 return n; 1357 /* adjust buffer */ 1358 adjust = *bufpos - n; 1359 if (adjust > 0) 1360 memmove(buf, buf + n, adjust); 1361 *bufpos -= n; 1362 return n; 1363 } 1364 1365 ssize_t 1366 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1367 { 1368 size_t num = BUFSIZE - *bufpos; 1369 ssize_t n; 1370 1371 if (tls) { 1372 n = tls_read(tls, buf + *bufpos, num); 1373 if (n == -1) 1374 errx(1, "tls read failed (%s)", tls_error(tls)); 1375 } else { 1376 n = read(fd, buf + *bufpos, num); 1377 /* don't treat EAGAIN, EINTR as error */ 1378 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1379 n = TLS_WANT_POLLIN; 1380 } 1381 if (n <= 0) 1382 return n; 1383 *bufpos += n; 1384 return n; 1385 } 1386 1387 /* 1388 * fdpass() 1389 * Pass the connected file descriptor to stdout and exit. 1390 */ 1391 void 1392 fdpass(int nfd) 1393 { 1394 struct msghdr mh; 1395 union { 1396 struct cmsghdr hdr; 1397 char buf[CMSG_SPACE(sizeof(int))]; 1398 } cmsgbuf; 1399 struct cmsghdr *cmsg; 1400 struct iovec iov; 1401 char c = '\0'; 1402 ssize_t r; 1403 struct pollfd pfd; 1404 1405 /* Avoid obvious stupidity */ 1406 if (isatty(STDOUT_FILENO)) 1407 errx(1, "Cannot pass file descriptor to tty"); 1408 1409 memset(&mh, 0, sizeof(mh)); 1410 memset(&cmsgbuf, 0, sizeof(cmsgbuf)); 1411 memset(&iov, 0, sizeof(iov)); 1412 1413 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1414 mh.msg_controllen = sizeof(cmsgbuf.buf); 1415 cmsg = CMSG_FIRSTHDR(&mh); 1416 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1417 cmsg->cmsg_level = SOL_SOCKET; 1418 cmsg->cmsg_type = SCM_RIGHTS; 1419 *(int *)CMSG_DATA(cmsg) = nfd; 1420 1421 iov.iov_base = &c; 1422 iov.iov_len = 1; 1423 mh.msg_iov = &iov; 1424 mh.msg_iovlen = 1; 1425 1426 memset(&pfd, 0, sizeof(pfd)); 1427 pfd.fd = STDOUT_FILENO; 1428 pfd.events = POLLOUT; 1429 for (;;) { 1430 r = sendmsg(STDOUT_FILENO, &mh, 0); 1431 if (r == -1) { 1432 if (errno == EAGAIN || errno == EINTR) { 1433 if (poll(&pfd, 1, -1) == -1) 1434 err(1, "poll"); 1435 continue; 1436 } 1437 err(1, "sendmsg"); 1438 } else if (r != 1) 1439 errx(1, "sendmsg: unexpected return value %zd", r); 1440 else 1441 break; 1442 } 1443 exit(0); 1444 } 1445 1446 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1447 void 1448 atelnet(int nfd, unsigned char *buf, unsigned int size) 1449 { 1450 unsigned char *p, *end; 1451 unsigned char obuf[4]; 1452 1453 if (size < 3) 1454 return; 1455 end = buf + size - 2; 1456 1457 for (p = buf; p < end; p++) { 1458 if (*p != IAC) 1459 continue; 1460 1461 obuf[0] = IAC; 1462 p++; 1463 if ((*p == WILL) || (*p == WONT)) 1464 obuf[1] = DONT; 1465 else if ((*p == DO) || (*p == DONT)) 1466 obuf[1] = WONT; 1467 else 1468 continue; 1469 1470 p++; 1471 obuf[2] = *p; 1472 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1473 warn("Write Error!"); 1474 } 1475 } 1476 1477 1478 int 1479 strtoport(char *portstr, int udp) 1480 { 1481 struct servent *entry; 1482 const char *errstr; 1483 char *proto; 1484 int port = -1; 1485 1486 proto = udp ? "udp" : "tcp"; 1487 1488 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1489 if (errstr == NULL) 1490 return port; 1491 if (errno != EINVAL) 1492 errx(1, "port number %s: %s", errstr, portstr); 1493 if ((entry = getservbyname(portstr, proto)) == NULL) 1494 errx(1, "service \"%s\" unknown", portstr); 1495 return ntohs(entry->s_port); 1496 } 1497 1498 /* 1499 * build_ports() 1500 * Build an array of ports in portlist[], listing each port 1501 * that we should try to connect to. 1502 */ 1503 void 1504 build_ports(char *p) 1505 { 1506 char *n; 1507 int hi, lo, cp; 1508 int x = 0; 1509 1510 if (isdigit((unsigned char)*p) && (n = strchr(p, '-')) != NULL) { 1511 *n = '\0'; 1512 n++; 1513 1514 /* Make sure the ports are in order: lowest->highest. */ 1515 hi = strtoport(n, uflag); 1516 lo = strtoport(p, uflag); 1517 if (lo > hi) { 1518 cp = hi; 1519 hi = lo; 1520 lo = cp; 1521 } 1522 1523 /* 1524 * Initialize portlist with a random permutation. Based on 1525 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1526 */ 1527 if (rflag) { 1528 for (x = 0; x <= hi - lo; x++) { 1529 cp = arc4random_uniform(x + 1); 1530 portlist[x] = portlist[cp]; 1531 if (asprintf(&portlist[cp], "%d", x + lo) == -1) 1532 err(1, "asprintf"); 1533 } 1534 } else { /* Load ports sequentially. */ 1535 for (cp = lo; cp <= hi; cp++) { 1536 if (asprintf(&portlist[x], "%d", cp) == -1) 1537 err(1, "asprintf"); 1538 x++; 1539 } 1540 } 1541 } else { 1542 char *tmp; 1543 1544 hi = strtoport(p, uflag); 1545 if (asprintf(&tmp, "%d", hi) != -1) 1546 portlist[0] = tmp; 1547 else 1548 err(1, NULL); 1549 } 1550 } 1551 1552 /* 1553 * udptest() 1554 * Do a few writes to see if the UDP port is there. 1555 * Fails once PF state table is full. 1556 */ 1557 int 1558 udptest(int s) 1559 { 1560 int i, ret; 1561 1562 for (i = 0; i <= 3; i++) { 1563 if (write(s, "X", 1) == 1) 1564 ret = 1; 1565 else 1566 ret = -1; 1567 } 1568 return ret; 1569 } 1570 1571 void 1572 set_common_sockopts(int s, int af) 1573 { 1574 int x = 1; 1575 1576 #ifdef TCP_MD5SIG 1577 if (Sflag) { 1578 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1579 &x, sizeof(x)) == -1) 1580 err(1, NULL); 1581 } 1582 #endif 1583 if (Dflag) { 1584 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1585 &x, sizeof(x)) == -1) 1586 err(1, NULL); 1587 } 1588 if (Tflag != -1) { 1589 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1590 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1591 err(1, "set IP ToS"); 1592 1593 #ifdef IPV6_TCLASS 1594 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1595 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1596 err(1, "set IPv6 traffic class"); 1597 #else 1598 else if (af == AF_INET6) { 1599 errno = ENOPROTOOPT; 1600 err(1, "set IPv6 traffic class not supported"); 1601 } 1602 #endif 1603 } 1604 if (Iflag) { 1605 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1606 &Iflag, sizeof(Iflag)) == -1) 1607 err(1, "set TCP receive buffer size"); 1608 } 1609 if (Oflag) { 1610 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1611 &Oflag, sizeof(Oflag)) == -1) 1612 err(1, "set TCP send buffer size"); 1613 } 1614 1615 if (ttl != -1) { 1616 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1617 IP_TTL, &ttl, sizeof(ttl))) 1618 err(1, "set IP TTL"); 1619 1620 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1621 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1622 err(1, "set IPv6 unicast hops"); 1623 } 1624 1625 if (minttl != -1) { 1626 #ifdef IP_MINTTL 1627 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1628 IP_MINTTL, &minttl, sizeof(minttl))) 1629 err(1, "set IP min TTL"); 1630 #endif 1631 1632 #ifdef IPV6_MINHOPCOUNT 1633 if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1634 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1635 err(1, "set IPv6 min hop count"); 1636 #endif 1637 } 1638 } 1639 1640 int 1641 process_tos_opt(char *s, int *val) 1642 { 1643 /* DiffServ Codepoints and other TOS mappings */ 1644 const struct toskeywords { 1645 const char *keyword; 1646 int val; 1647 } *t, toskeywords[] = { 1648 { "af11", IPTOS_DSCP_AF11 }, 1649 { "af12", IPTOS_DSCP_AF12 }, 1650 { "af13", IPTOS_DSCP_AF13 }, 1651 { "af21", IPTOS_DSCP_AF21 }, 1652 { "af22", IPTOS_DSCP_AF22 }, 1653 { "af23", IPTOS_DSCP_AF23 }, 1654 { "af31", IPTOS_DSCP_AF31 }, 1655 { "af32", IPTOS_DSCP_AF32 }, 1656 { "af33", IPTOS_DSCP_AF33 }, 1657 { "af41", IPTOS_DSCP_AF41 }, 1658 { "af42", IPTOS_DSCP_AF42 }, 1659 { "af43", IPTOS_DSCP_AF43 }, 1660 { "critical", IPTOS_PREC_CRITIC_ECP }, 1661 { "cs0", IPTOS_DSCP_CS0 }, 1662 { "cs1", IPTOS_DSCP_CS1 }, 1663 { "cs2", IPTOS_DSCP_CS2 }, 1664 { "cs3", IPTOS_DSCP_CS3 }, 1665 { "cs4", IPTOS_DSCP_CS4 }, 1666 { "cs5", IPTOS_DSCP_CS5 }, 1667 { "cs6", IPTOS_DSCP_CS6 }, 1668 { "cs7", IPTOS_DSCP_CS7 }, 1669 { "ef", IPTOS_DSCP_EF }, 1670 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1671 { "lowdelay", IPTOS_LOWDELAY }, 1672 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1673 { "reliability", IPTOS_RELIABILITY }, 1674 { "throughput", IPTOS_THROUGHPUT }, 1675 { NULL, -1 }, 1676 }; 1677 1678 for (t = toskeywords; t->keyword != NULL; t++) { 1679 if (strcmp(s, t->keyword) == 0) { 1680 *val = t->val; 1681 return 1; 1682 } 1683 } 1684 1685 return 0; 1686 } 1687 1688 int 1689 process_tls_opt(char *s, int *flags) 1690 { 1691 size_t len; 1692 char *v; 1693 1694 const struct tlskeywords { 1695 const char *keyword; 1696 int flag; 1697 char **value; 1698 } *t, tlskeywords[] = { 1699 { "ciphers", -1, &tls_ciphers }, 1700 { "clientcert", TLS_CCERT, NULL }, 1701 { "muststaple", TLS_MUSTSTAPLE, NULL }, 1702 { "noverify", TLS_NOVERIFY, NULL }, 1703 { "noname", TLS_NONAME, NULL }, 1704 { "protocols", -1, &tls_protocols }, 1705 { NULL, -1, NULL }, 1706 }; 1707 1708 len = strlen(s); 1709 if ((v = strchr(s, '=')) != NULL) { 1710 len = v - s; 1711 v++; 1712 } 1713 1714 for (t = tlskeywords; t->keyword != NULL; t++) { 1715 if (strlen(t->keyword) == len && 1716 strncmp(s, t->keyword, len) == 0) { 1717 if (t->value != NULL) { 1718 if (v == NULL) 1719 errx(1, "invalid tls value `%s'", s); 1720 *t->value = v; 1721 } else { 1722 *flags |= t->flag; 1723 } 1724 return 1; 1725 } 1726 } 1727 return 0; 1728 } 1729 1730 void 1731 save_peer_cert(struct tls *tls_ctx, FILE *fp) 1732 { 1733 const char *pem; 1734 size_t plen; 1735 1736 if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL) 1737 errx(1, "Can't get peer certificate"); 1738 if (fprintf(fp, "%.*s", (int)plen, pem) < 0) 1739 err(1, "unable to save peer cert"); 1740 if (fflush(fp) != 0) 1741 err(1, "unable to flush peer cert"); 1742 } 1743 1744 void 1745 report_tls(struct tls * tls_ctx, char * host) 1746 { 1747 time_t t; 1748 const char *ocsp_url; 1749 1750 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1751 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1752 fprintf(stderr, "Peer name: %s\n", 1753 tls_expectname ? tls_expectname : host); 1754 if (tls_peer_cert_subject(tls_ctx)) 1755 fprintf(stderr, "Subject: %s\n", 1756 tls_peer_cert_subject(tls_ctx)); 1757 if (tls_peer_cert_issuer(tls_ctx)) 1758 fprintf(stderr, "Issuer: %s\n", 1759 tls_peer_cert_issuer(tls_ctx)); 1760 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1761 fprintf(stderr, "Valid From: %s", ctime(&t)); 1762 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1763 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1764 if (tls_peer_cert_hash(tls_ctx)) 1765 fprintf(stderr, "Cert Hash: %s\n", 1766 tls_peer_cert_hash(tls_ctx)); 1767 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1768 if (ocsp_url != NULL) 1769 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1770 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1771 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1772 fprintf(stderr, "OCSP Stapling: %s\n", 1773 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1774 tls_peer_ocsp_result(tls_ctx)); 1775 fprintf(stderr, 1776 " response_status=%d cert_status=%d crl_reason=%d\n", 1777 tls_peer_ocsp_response_status(tls_ctx), 1778 tls_peer_ocsp_cert_status(tls_ctx), 1779 tls_peer_ocsp_crl_reason(tls_ctx)); 1780 t = tls_peer_ocsp_this_update(tls_ctx); 1781 fprintf(stderr, " this update: %s", 1782 t != -1 ? ctime(&t) : "\n"); 1783 t = tls_peer_ocsp_next_update(tls_ctx); 1784 fprintf(stderr, " next update: %s", 1785 t != -1 ? ctime(&t) : "\n"); 1786 t = tls_peer_ocsp_revocation_time(tls_ctx); 1787 fprintf(stderr, " revocation: %s", 1788 t != -1 ? ctime(&t) : "\n"); 1789 break; 1790 case -1: 1791 break; 1792 default: 1793 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1794 tls_peer_ocsp_response_status(tls_ctx), 1795 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1796 tls_peer_ocsp_result(tls_ctx)); 1797 break; 1798 1799 } 1800 } 1801 1802 void 1803 report_sock(const char *msg, const struct sockaddr *sa, socklen_t salen, 1804 char *path) 1805 { 1806 char host[NI_MAXHOST], port[NI_MAXSERV]; 1807 int herr; 1808 int flags = NI_NUMERICSERV; 1809 1810 if (path != NULL) { 1811 fprintf(stderr, "%s on %s\n", msg, path); 1812 return; 1813 } 1814 1815 if (nflag) 1816 flags |= NI_NUMERICHOST; 1817 1818 herr = getnameinfo(sa, salen, host, sizeof(host), port, sizeof(port), 1819 flags); 1820 switch (herr) { 1821 case 0: 1822 break; 1823 case EAI_SYSTEM: 1824 err(1, "getnameinfo"); 1825 default: 1826 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1827 } 1828 1829 fprintf(stderr, "%s on %s %s\n", msg, host, port); 1830 } 1831 1832 void 1833 help(void) 1834 { 1835 usage(0); 1836 fprintf(stderr, "\tCommand Summary:\n\ 1837 \t-4 Use IPv4\n\ 1838 \t-6 Use IPv6\n\ 1839 \t-C certfile Public key file\n\ 1840 \t-c Use TLS\n\ 1841 \t-D Enable the debug socket option\n\ 1842 \t-d Detach from stdin\n\ 1843 \t-e name\t Required name in peer certificate\n\ 1844 \t-F Pass socket fd\n\ 1845 \t-H hash\t Hash string of peer certificate\n\ 1846 \t-h This help text\n\ 1847 \t-I length TCP receive buffer length\n\ 1848 \t-i interval Delay interval for lines sent, ports scanned\n\ 1849 \t-K keyfile Private key file\n\ 1850 \t-k Keep inbound sockets open for multiple connects\n\ 1851 \t-l Listen mode, for inbound connects\n\ 1852 \t-M ttl Outgoing TTL / Hop Limit\n\ 1853 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1854 \t-N Shutdown the network socket after EOF on stdin\n\ 1855 \t-n Suppress name/port resolutions\n\ 1856 \t-O length TCP send buffer length\n\ 1857 \t-o staplefile Staple file\n\ 1858 \t-P proxyuser\tUsername for proxy authentication\n\ 1859 \t-p port\t Specify local port for remote connects\n\ 1860 \t-R CAfile CA bundle\n\ 1861 \t-r Randomize remote ports\n" 1862 #ifdef TCP_MD5SIG 1863 "\t-S Enable the TCP MD5 signature option\n" 1864 #endif 1865 "\t-s sourceaddr Local source address\n\ 1866 \t-T keyword TOS value or TLS options\n\ 1867 \t-t Answer TELNET negotiation\n\ 1868 \t-U Use UNIX domain socket\n\ 1869 \t-u UDP mode\n" 1870 #ifdef SO_RTABLE 1871 "\t-V rtable Specify alternate routing table\n" 1872 #endif 1873 "\t-v Verbose\n\ 1874 \t-W recvlimit Terminate after receiving a number of packets\n\ 1875 \t-w timeout Timeout for connects and final net reads\n\ 1876 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1877 \t-x addr[:port]\tSpecify proxy address and port\n\ 1878 \t-Z Peer certificate file\n\ 1879 \t-z Zero-I/O mode [used for scanning]\n\ 1880 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1881 exit(1); 1882 } 1883 1884 void 1885 usage(int ret) 1886 { 1887 fprintf(stderr, 1888 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1889 "[-H hash] [-I length]\n" 1890 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1891 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1892 "[-R CAfile]\n" 1893 "\t [-s sourceaddr] [-T keyword] [-V rtable] [-W recvlimit] " 1894 "[-w timeout]\n" 1895 "\t [-X proxy_protocol] [-x proxy_address[:port]] " 1896 "[-Z peercertfile]\n" 1897 "\t [destination] [port]\n"); 1898 if (ret) 1899 exit(1); 1900 } 1901