1 /* $OpenBSD: netcat.c,v 1.171 2016/11/30 07:56:23 mestre Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org> 4 * Copyright (c) 2015 Bob Beck. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * Re-written nc(1) for OpenBSD. Original implementation by 32 * *Hobbit* <hobbit@avian.org>. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 40 #include <netinet/in.h> 41 #include <netinet/tcp.h> 42 #include <netinet/ip.h> 43 #include <arpa/telnet.h> 44 45 #include <err.h> 46 #include <errno.h> 47 #include <limits.h> 48 #include <netdb.h> 49 #include <poll.h> 50 #include <signal.h> 51 #include <stdarg.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <time.h> 56 #include <unistd.h> 57 #include <tls.h> 58 #include "atomicio.h" 59 60 #define PORT_MAX 65535 61 #define UNIX_DG_TMP_SOCKET_SIZE 19 62 63 #define POLL_STDIN 0 64 #define POLL_NETOUT 1 65 #define POLL_NETIN 2 66 #define POLL_STDOUT 3 67 #define BUFSIZE 16384 68 #define DEFAULT_CA_FILE "/etc/ssl/cert.pem" 69 70 #define TLS_ALL (1 << 1) 71 #define TLS_NOVERIFY (1 << 2) 72 #define TLS_NONAME (1 << 3) 73 #define TLS_CCERT (1 << 4) 74 #define TLS_MUSTSTAPLE (1 << 5) 75 76 /* Command Line Options */ 77 int dflag; /* detached, no stdin */ 78 int Fflag; /* fdpass sock to stdout */ 79 unsigned int iflag; /* Interval Flag */ 80 int kflag; /* More than one connect */ 81 int lflag; /* Bind to local port */ 82 int Nflag; /* shutdown() network socket */ 83 int nflag; /* Don't do name look up */ 84 char *Pflag; /* Proxy username */ 85 char *pflag; /* Localport flag */ 86 int rflag; /* Random ports flag */ 87 char *sflag; /* Source Address */ 88 int tflag; /* Telnet Emulation */ 89 int uflag; /* UDP - Default to TCP */ 90 int vflag; /* Verbosity */ 91 int xflag; /* Socks proxy */ 92 int zflag; /* Port Scan Flag */ 93 int Dflag; /* sodebug */ 94 int Iflag; /* TCP receive buffer size */ 95 int Oflag; /* TCP send buffer size */ 96 int Sflag; /* TCP MD5 signature option */ 97 int Tflag = -1; /* IP Type of Service */ 98 int rtableid = -1; 99 100 int usetls; /* use TLS */ 101 char *Cflag; /* Public cert file */ 102 char *Kflag; /* Private key file */ 103 char *oflag; /* OCSP stapling file */ 104 char *Rflag = DEFAULT_CA_FILE; /* Root CA file */ 105 int tls_cachanged; /* Using non-default CA file */ 106 int TLSopt; /* TLS options */ 107 char *tls_expectname; /* required name in peer cert */ 108 char *tls_expecthash; /* required hash of peer cert */ 109 110 int timeout = -1; 111 int family = AF_UNSPEC; 112 char *portlist[PORT_MAX+1]; 113 char *unix_dg_tmp_socket; 114 int ttl = -1; 115 int minttl = -1; 116 117 void atelnet(int, unsigned char *, unsigned int); 118 void build_ports(char *); 119 void help(void); 120 int local_listen(char *, char *, struct addrinfo); 121 void readwrite(int, struct tls *); 122 void fdpass(int nfd) __attribute__((noreturn)); 123 int remote_connect(const char *, const char *, struct addrinfo); 124 int timeout_connect(int, const struct sockaddr *, socklen_t); 125 int socks_connect(const char *, const char *, struct addrinfo, 126 const char *, const char *, struct addrinfo, int, const char *); 127 int udptest(int); 128 int unix_bind(char *, int); 129 int unix_connect(char *); 130 int unix_listen(char *); 131 void set_common_sockopts(int, int); 132 int map_tos(char *, int *); 133 int map_tls(char *, int *); 134 void report_connect(const struct sockaddr *, socklen_t, char *); 135 void report_tls(struct tls *tls_ctx, char * host, char *tls_expectname); 136 void usage(int); 137 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 138 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 139 void tls_setup_client(struct tls *, int, char *); 140 struct tls *tls_setup_server(struct tls *, int, char *); 141 142 int 143 main(int argc, char *argv[]) 144 { 145 int ch, s = -1, ret, socksv; 146 char *host, *uport; 147 struct addrinfo hints; 148 struct servent *sv; 149 socklen_t len; 150 struct sockaddr_storage cliaddr; 151 char *proxy; 152 const char *errstr, *proxyhost = "", *proxyport = NULL; 153 struct addrinfo proxyhints; 154 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 155 struct tls_config *tls_cfg = NULL; 156 struct tls *tls_ctx = NULL; 157 158 ret = 1; 159 socksv = 5; 160 host = NULL; 161 uport = NULL; 162 sv = NULL; 163 164 signal(SIGPIPE, SIG_IGN); 165 166 while ((ch = getopt(argc, argv, 167 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vw:X:x:z")) != -1) { 168 switch (ch) { 169 case '4': 170 family = AF_INET; 171 break; 172 case '6': 173 family = AF_INET6; 174 break; 175 case 'U': 176 family = AF_UNIX; 177 break; 178 case 'X': 179 if (strcasecmp(optarg, "connect") == 0) 180 socksv = -1; /* HTTP proxy CONNECT */ 181 else if (strcmp(optarg, "4") == 0) 182 socksv = 4; /* SOCKS v.4 */ 183 else if (strcmp(optarg, "5") == 0) 184 socksv = 5; /* SOCKS v.5 */ 185 else 186 errx(1, "unsupported proxy protocol"); 187 break; 188 case 'C': 189 Cflag = optarg; 190 break; 191 case 'c': 192 usetls = 1; 193 break; 194 case 'd': 195 dflag = 1; 196 break; 197 case 'e': 198 tls_expectname = optarg; 199 break; 200 case 'F': 201 Fflag = 1; 202 break; 203 case 'H': 204 tls_expecthash = optarg; 205 break; 206 case 'h': 207 help(); 208 break; 209 case 'i': 210 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 211 if (errstr) 212 errx(1, "interval %s: %s", errstr, optarg); 213 break; 214 case 'K': 215 Kflag = optarg; 216 break; 217 case 'k': 218 kflag = 1; 219 break; 220 case 'l': 221 lflag = 1; 222 break; 223 case 'M': 224 ttl = strtonum(optarg, 0, 255, &errstr); 225 if (errstr) 226 errx(1, "ttl is %s", errstr); 227 break; 228 case 'm': 229 minttl = strtonum(optarg, 0, 255, &errstr); 230 if (errstr) 231 errx(1, "minttl is %s", errstr); 232 break; 233 case 'N': 234 Nflag = 1; 235 break; 236 case 'n': 237 nflag = 1; 238 break; 239 case 'P': 240 Pflag = optarg; 241 break; 242 case 'p': 243 pflag = optarg; 244 break; 245 case 'R': 246 tls_cachanged = 1; 247 Rflag = optarg; 248 break; 249 case 'r': 250 rflag = 1; 251 break; 252 case 's': 253 sflag = optarg; 254 break; 255 case 't': 256 tflag = 1; 257 break; 258 case 'u': 259 uflag = 1; 260 break; 261 case 'V': 262 rtableid = (int)strtonum(optarg, 0, 263 RT_TABLEID_MAX, &errstr); 264 if (errstr) 265 errx(1, "rtable %s: %s", errstr, optarg); 266 break; 267 case 'v': 268 vflag = 1; 269 break; 270 case 'w': 271 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 272 if (errstr) 273 errx(1, "timeout %s: %s", errstr, optarg); 274 timeout *= 1000; 275 break; 276 case 'x': 277 xflag = 1; 278 if ((proxy = strdup(optarg)) == NULL) 279 err(1, NULL); 280 break; 281 case 'z': 282 zflag = 1; 283 break; 284 case 'D': 285 Dflag = 1; 286 break; 287 case 'I': 288 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 289 if (errstr != NULL) 290 errx(1, "TCP receive window %s: %s", 291 errstr, optarg); 292 break; 293 case 'O': 294 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 295 if (errstr != NULL) 296 errx(1, "TCP send window %s: %s", 297 errstr, optarg); 298 break; 299 case 'o': 300 oflag = optarg; 301 break; 302 case 'S': 303 Sflag = 1; 304 break; 305 case 'T': 306 errstr = NULL; 307 errno = 0; 308 if (map_tos(optarg, &Tflag)) 309 break; 310 if (map_tls(optarg, &TLSopt)) 311 break; 312 if (strlen(optarg) > 1 && optarg[0] == '0' && 313 optarg[1] == 'x') 314 Tflag = (int)strtol(optarg, NULL, 16); 315 else 316 Tflag = (int)strtonum(optarg, 0, 255, 317 &errstr); 318 if (Tflag < 0 || Tflag > 255 || errstr || errno) 319 errx(1, "illegal tos/tls value %s", optarg); 320 break; 321 default: 322 usage(1); 323 } 324 } 325 argc -= optind; 326 argv += optind; 327 328 if (rtableid >= 0) 329 if (setrtable(rtableid) == -1) 330 err(1, "setrtable"); 331 332 if (family == AF_UNIX) { 333 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 334 err(1, "pledge"); 335 } else if (Fflag) { 336 if (Pflag) { 337 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 338 err(1, "pledge"); 339 } else if (pledge("stdio inet dns sendfd", NULL) == -1) 340 err(1, "pledge"); 341 } else if (Pflag) { 342 if (pledge("stdio inet dns tty", NULL) == -1) 343 err(1, "pledge"); 344 } else if (usetls) { 345 if (pledge("stdio rpath inet dns", NULL) == -1) 346 err(1, "pledge"); 347 } else if (pledge("stdio inet dns", NULL) == -1) 348 err(1, "pledge"); 349 350 /* Cruft to make sure options are clean, and used properly. */ 351 if (argv[0] && !argv[1] && family == AF_UNIX) { 352 host = argv[0]; 353 uport = NULL; 354 } else if (argv[0] && !argv[1]) { 355 if (!lflag) 356 usage(1); 357 uport = argv[0]; 358 host = NULL; 359 } else if (argv[0] && argv[1]) { 360 host = argv[0]; 361 uport = argv[1]; 362 } else 363 usage(1); 364 365 if (lflag && sflag) 366 errx(1, "cannot use -s and -l"); 367 if (lflag && pflag) 368 errx(1, "cannot use -p and -l"); 369 if (lflag && zflag) 370 errx(1, "cannot use -z and -l"); 371 if (!lflag && kflag) 372 errx(1, "must use -l with -k"); 373 if (uflag && usetls) 374 errx(1, "cannot use -c and -u"); 375 if ((family == AF_UNIX) && usetls) 376 errx(1, "cannot use -c and -U"); 377 if ((family == AF_UNIX) && Fflag) 378 errx(1, "cannot use -F and -U"); 379 if (Fflag && usetls) 380 errx(1, "cannot use -c and -F"); 381 if (TLSopt && !usetls) 382 errx(1, "you must specify -c to use TLS options"); 383 if (Cflag && !usetls) 384 errx(1, "you must specify -c to use -C"); 385 if (Kflag && !usetls) 386 errx(1, "you must specify -c to use -K"); 387 if (oflag && !Cflag) 388 errx(1, "you must specify -C to use -o"); 389 if (tls_cachanged && !usetls) 390 errx(1, "you must specify -c to use -R"); 391 if (tls_expecthash && !usetls) 392 errx(1, "you must specify -c to use -H"); 393 if (tls_expectname && !usetls) 394 errx(1, "you must specify -c to use -e"); 395 396 /* Get name of temporary socket for unix datagram client */ 397 if ((family == AF_UNIX) && uflag && !lflag) { 398 if (sflag) { 399 unix_dg_tmp_socket = sflag; 400 } else { 401 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 402 UNIX_DG_TMP_SOCKET_SIZE); 403 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 404 err(1, "mktemp"); 405 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 406 } 407 } 408 409 /* Initialize addrinfo structure. */ 410 if (family != AF_UNIX) { 411 memset(&hints, 0, sizeof(struct addrinfo)); 412 hints.ai_family = family; 413 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 414 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 415 if (nflag) 416 hints.ai_flags |= AI_NUMERICHOST; 417 } 418 419 if (xflag) { 420 if (uflag) 421 errx(1, "no proxy support for UDP mode"); 422 423 if (lflag) 424 errx(1, "no proxy support for listen"); 425 426 if (family == AF_UNIX) 427 errx(1, "no proxy support for unix sockets"); 428 429 /* XXX IPv6 transport to proxy would probably work */ 430 if (family == AF_INET6) 431 errx(1, "no proxy support for IPv6"); 432 433 if (sflag) 434 errx(1, "no proxy support for local source address"); 435 436 proxyhost = strsep(&proxy, ":"); 437 proxyport = proxy; 438 439 memset(&proxyhints, 0, sizeof(struct addrinfo)); 440 proxyhints.ai_family = family; 441 proxyhints.ai_socktype = SOCK_STREAM; 442 proxyhints.ai_protocol = IPPROTO_TCP; 443 if (nflag) 444 proxyhints.ai_flags |= AI_NUMERICHOST; 445 } 446 447 if (usetls) { 448 if (Pflag) { 449 if (pledge("stdio inet dns tty rpath", NULL) == -1) 450 err(1, "pledge"); 451 } else if (pledge("stdio inet dns rpath", NULL) == -1) 452 err(1, "pledge"); 453 454 if (tls_init() == -1) 455 errx(1, "unable to initialize TLS"); 456 if ((tls_cfg = tls_config_new()) == NULL) 457 errx(1, "unable to allocate TLS config"); 458 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 459 errx(1, "%s", tls_config_error(tls_cfg)); 460 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 461 errx(1, "%s", tls_config_error(tls_cfg)); 462 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 463 errx(1, "%s", tls_config_error(tls_cfg)); 464 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 465 errx(1, "%s", tls_config_error(tls_cfg)); 466 if (TLSopt & TLS_ALL) { 467 if (tls_config_set_protocols(tls_cfg, 468 TLS_PROTOCOLS_ALL) != 0) 469 errx(1, "%s", tls_config_error(tls_cfg)); 470 if (tls_config_set_ciphers(tls_cfg, "all") != 0) 471 errx(1, "%s", tls_config_error(tls_cfg)); 472 } 473 if (!lflag && (TLSopt & TLS_CCERT)) 474 errx(1, "clientcert is only valid with -l"); 475 if (TLSopt & TLS_NONAME) 476 tls_config_insecure_noverifyname(tls_cfg); 477 if (TLSopt & TLS_NOVERIFY) { 478 if (tls_expecthash != NULL) 479 errx(1, "-H and -T noverify may not be used" 480 "together"); 481 tls_config_insecure_noverifycert(tls_cfg); 482 } 483 if (TLSopt & TLS_MUSTSTAPLE) 484 tls_config_ocsp_require_stapling(tls_cfg); 485 486 if (Pflag) { 487 if (pledge("stdio inet dns tty", NULL) == -1) 488 err(1, "pledge"); 489 } else if (pledge("stdio inet dns", NULL) == -1) 490 err(1, "pledge"); 491 } 492 if (lflag) { 493 struct tls *tls_cctx = NULL; 494 int connfd; 495 ret = 0; 496 497 if (family == AF_UNIX) { 498 if (uflag) 499 s = unix_bind(host, 0); 500 else 501 s = unix_listen(host); 502 } 503 504 if (usetls) { 505 tls_config_verify_client_optional(tls_cfg); 506 if ((tls_ctx = tls_server()) == NULL) 507 errx(1, "tls server creation failed"); 508 if (tls_configure(tls_ctx, tls_cfg) == -1) 509 errx(1, "tls configuration failed (%s)", 510 tls_error(tls_ctx)); 511 } 512 /* Allow only one connection at a time, but stay alive. */ 513 for (;;) { 514 if (family != AF_UNIX) 515 s = local_listen(host, uport, hints); 516 if (s < 0) 517 err(1, NULL); 518 /* 519 * For UDP and -k, don't connect the socket, let it 520 * receive datagrams from multiple socket pairs. 521 */ 522 if (uflag && kflag) 523 readwrite(s, NULL); 524 /* 525 * For UDP and not -k, we will use recvfrom() initially 526 * to wait for a caller, then use the regular functions 527 * to talk to the caller. 528 */ 529 else if (uflag && !kflag) { 530 int rv, plen; 531 char buf[16384]; 532 struct sockaddr_storage z; 533 534 len = sizeof(z); 535 plen = 2048; 536 rv = recvfrom(s, buf, plen, MSG_PEEK, 537 (struct sockaddr *)&z, &len); 538 if (rv < 0) 539 err(1, "recvfrom"); 540 541 rv = connect(s, (struct sockaddr *)&z, len); 542 if (rv < 0) 543 err(1, "connect"); 544 545 if (vflag) 546 report_connect((struct sockaddr *)&z, len, NULL); 547 548 readwrite(s, NULL); 549 } else { 550 len = sizeof(cliaddr); 551 connfd = accept4(s, (struct sockaddr *)&cliaddr, 552 &len, SOCK_NONBLOCK); 553 if (connfd == -1) { 554 /* For now, all errnos are fatal */ 555 err(1, "accept"); 556 } 557 if (vflag) 558 report_connect((struct sockaddr *)&cliaddr, len, 559 family == AF_UNIX ? host : NULL); 560 if ((usetls) && 561 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 562 readwrite(connfd, tls_cctx); 563 if (!usetls) 564 readwrite(connfd, NULL); 565 if (tls_cctx) { 566 int i; 567 568 do { 569 i = tls_close(tls_cctx); 570 } while (i == TLS_WANT_POLLIN || 571 i == TLS_WANT_POLLOUT); 572 tls_free(tls_cctx); 573 tls_cctx = NULL; 574 } 575 close(connfd); 576 } 577 if (family != AF_UNIX) 578 close(s); 579 else if (uflag) { 580 if (connect(s, NULL, 0) < 0) 581 err(1, "connect"); 582 } 583 584 if (!kflag) 585 break; 586 } 587 } else if (family == AF_UNIX) { 588 ret = 0; 589 590 if ((s = unix_connect(host)) > 0 && !zflag) { 591 readwrite(s, NULL); 592 close(s); 593 } else 594 ret = 1; 595 596 if (uflag) 597 unlink(unix_dg_tmp_socket); 598 exit(ret); 599 600 } else { 601 int i = 0; 602 603 /* Construct the portlist[] array. */ 604 build_ports(uport); 605 606 /* Cycle through portlist, connecting to each port. */ 607 for (s = -1, i = 0; portlist[i] != NULL; i++) { 608 if (s != -1) 609 close(s); 610 611 if (usetls) { 612 if ((tls_ctx = tls_client()) == NULL) 613 errx(1, "tls client creation failed"); 614 if (tls_configure(tls_ctx, tls_cfg) == -1) 615 errx(1, "tls configuration failed (%s)", 616 tls_error(tls_ctx)); 617 } 618 if (xflag) 619 s = socks_connect(host, portlist[i], hints, 620 proxyhost, proxyport, proxyhints, socksv, 621 Pflag); 622 else 623 s = remote_connect(host, portlist[i], hints); 624 625 if (s == -1) 626 continue; 627 628 ret = 0; 629 if (vflag || zflag) { 630 /* For UDP, make sure we are connected. */ 631 if (uflag) { 632 if (udptest(s) == -1) { 633 ret = 1; 634 continue; 635 } 636 } 637 638 /* Don't look up port if -n. */ 639 if (nflag) 640 sv = NULL; 641 else { 642 sv = getservbyport( 643 ntohs(atoi(portlist[i])), 644 uflag ? "udp" : "tcp"); 645 } 646 647 fprintf(stderr, 648 "Connection to %s %s port [%s/%s] " 649 "succeeded!\n", host, portlist[i], 650 uflag ? "udp" : "tcp", 651 sv ? sv->s_name : "*"); 652 } 653 if (Fflag) 654 fdpass(s); 655 else { 656 if (usetls) 657 tls_setup_client(tls_ctx, s, host); 658 if (!zflag) 659 readwrite(s, tls_ctx); 660 if (tls_ctx) { 661 int j; 662 663 do { 664 j = tls_close(tls_ctx); 665 } while (j == TLS_WANT_POLLIN || 666 j == TLS_WANT_POLLOUT); 667 tls_free(tls_ctx); 668 tls_ctx = NULL; 669 } 670 } 671 } 672 } 673 674 if (s != -1) 675 close(s); 676 677 tls_config_free(tls_cfg); 678 679 exit(ret); 680 } 681 682 /* 683 * unix_bind() 684 * Returns a unix socket bound to the given path 685 */ 686 int 687 unix_bind(char *path, int flags) 688 { 689 struct sockaddr_un s_un; 690 int s, save_errno; 691 692 /* Create unix domain socket. */ 693 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 694 0)) < 0) 695 return (-1); 696 697 memset(&s_un, 0, sizeof(struct sockaddr_un)); 698 s_un.sun_family = AF_UNIX; 699 700 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 701 sizeof(s_un.sun_path)) { 702 close(s); 703 errno = ENAMETOOLONG; 704 return (-1); 705 } 706 707 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 708 save_errno = errno; 709 close(s); 710 errno = save_errno; 711 return (-1); 712 } 713 return (s); 714 } 715 716 void 717 tls_setup_client(struct tls *tls_ctx, int s, char *host) 718 { 719 int i; 720 721 if (tls_connect_socket(tls_ctx, s, 722 tls_expectname ? tls_expectname : host) == -1) { 723 errx(1, "tls connection failed (%s)", 724 tls_error(tls_ctx)); 725 } 726 do { 727 if ((i = tls_handshake(tls_ctx)) == -1) 728 errx(1, "tls handshake failed (%s)", 729 tls_error(tls_ctx)); 730 } while (i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 731 if (vflag) 732 report_tls(tls_ctx, host, tls_expectname); 733 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 734 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 735 errx(1, "peer certificate is not %s", tls_expecthash); 736 } 737 738 struct tls * 739 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 740 { 741 struct tls *tls_cctx; 742 743 if (tls_accept_socket(tls_ctx, &tls_cctx, 744 connfd) == -1) { 745 warnx("tls accept failed (%s)", 746 tls_error(tls_ctx)); 747 tls_cctx = NULL; 748 } else { 749 int i; 750 751 do { 752 if ((i = tls_handshake(tls_cctx)) == -1) 753 warnx("tls handshake failed (%s)", 754 tls_error(tls_cctx)); 755 } while(i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 756 } 757 if (tls_cctx) { 758 int gotcert = tls_peer_cert_provided(tls_cctx); 759 760 if (vflag && gotcert) 761 report_tls(tls_cctx, host, tls_expectname); 762 if ((TLSopt & TLS_CCERT) && !gotcert) 763 warnx("No client certificate provided"); 764 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 765 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 766 warnx("peer certificate is not %s", tls_expecthash); 767 else if (gotcert && tls_expectname && 768 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 769 warnx("name (%s) not found in client cert", 770 tls_expectname); 771 else { 772 return tls_cctx; 773 } 774 } 775 return NULL; 776 } 777 778 /* 779 * unix_connect() 780 * Returns a socket connected to a local unix socket. Returns -1 on failure. 781 */ 782 int 783 unix_connect(char *path) 784 { 785 struct sockaddr_un s_un; 786 int s, save_errno; 787 788 if (uflag) { 789 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 790 return (-1); 791 } else { 792 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 793 return (-1); 794 } 795 796 memset(&s_un, 0, sizeof(struct sockaddr_un)); 797 s_un.sun_family = AF_UNIX; 798 799 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 800 sizeof(s_un.sun_path)) { 801 close(s); 802 errno = ENAMETOOLONG; 803 return (-1); 804 } 805 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 806 save_errno = errno; 807 close(s); 808 errno = save_errno; 809 return (-1); 810 } 811 return (s); 812 813 } 814 815 /* 816 * unix_listen() 817 * Create a unix domain socket, and listen on it. 818 */ 819 int 820 unix_listen(char *path) 821 { 822 int s; 823 if ((s = unix_bind(path, 0)) < 0) 824 return (-1); 825 826 if (listen(s, 5) < 0) { 827 close(s); 828 return (-1); 829 } 830 return (s); 831 } 832 833 /* 834 * remote_connect() 835 * Returns a socket connected to a remote host. Properly binds to a local 836 * port or source address if needed. Returns -1 on failure. 837 */ 838 int 839 remote_connect(const char *host, const char *port, struct addrinfo hints) 840 { 841 struct addrinfo *res, *res0; 842 int s = -1, error, on = 1, save_errno; 843 844 if ((error = getaddrinfo(host, port, &hints, &res0))) 845 errx(1, "getaddrinfo: %s", gai_strerror(error)); 846 847 for (res = res0; res; res = res->ai_next) { 848 if ((s = socket(res->ai_family, res->ai_socktype | 849 SOCK_NONBLOCK, res->ai_protocol)) < 0) 850 continue; 851 852 /* Bind to a local port or source address if specified. */ 853 if (sflag || pflag) { 854 struct addrinfo ahints, *ares; 855 856 /* try SO_BINDANY, but don't insist */ 857 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 858 memset(&ahints, 0, sizeof(struct addrinfo)); 859 ahints.ai_family = res->ai_family; 860 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 861 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 862 ahints.ai_flags = AI_PASSIVE; 863 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 864 errx(1, "getaddrinfo: %s", gai_strerror(error)); 865 866 if (bind(s, (struct sockaddr *)ares->ai_addr, 867 ares->ai_addrlen) < 0) 868 err(1, "bind failed"); 869 freeaddrinfo(ares); 870 } 871 872 set_common_sockopts(s, res->ai_family); 873 874 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 875 break; 876 if (vflag) 877 warn("connect to %s port %s (%s) failed", host, port, 878 uflag ? "udp" : "tcp"); 879 880 save_errno = errno; 881 close(s); 882 errno = save_errno; 883 s = -1; 884 } 885 886 freeaddrinfo(res0); 887 888 return (s); 889 } 890 891 int 892 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 893 { 894 struct pollfd pfd; 895 socklen_t optlen; 896 int optval; 897 int ret; 898 899 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 900 pfd.fd = s; 901 pfd.events = POLLOUT; 902 if ((ret = poll(&pfd, 1, timeout)) == 1) { 903 optlen = sizeof(optval); 904 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 905 &optval, &optlen)) == 0) { 906 errno = optval; 907 ret = optval == 0 ? 0 : -1; 908 } 909 } else if (ret == 0) { 910 errno = ETIMEDOUT; 911 ret = -1; 912 } else 913 err(1, "poll failed"); 914 } 915 916 return (ret); 917 } 918 919 /* 920 * local_listen() 921 * Returns a socket listening on a local port, binds to specified source 922 * address. Returns -1 on failure. 923 */ 924 int 925 local_listen(char *host, char *port, struct addrinfo hints) 926 { 927 struct addrinfo *res, *res0; 928 int s = -1, ret, x = 1, save_errno; 929 int error; 930 931 /* Allow nodename to be null. */ 932 hints.ai_flags |= AI_PASSIVE; 933 934 /* 935 * In the case of binding to a wildcard address 936 * default to binding to an ipv4 address. 937 */ 938 if (host == NULL && hints.ai_family == AF_UNSPEC) 939 hints.ai_family = AF_INET; 940 941 if ((error = getaddrinfo(host, port, &hints, &res0))) 942 errx(1, "getaddrinfo: %s", gai_strerror(error)); 943 944 for (res = res0; res; res = res->ai_next) { 945 if ((s = socket(res->ai_family, res->ai_socktype, 946 res->ai_protocol)) < 0) 947 continue; 948 949 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 950 if (ret == -1) 951 err(1, NULL); 952 953 set_common_sockopts(s, res->ai_family); 954 955 if (bind(s, (struct sockaddr *)res->ai_addr, 956 res->ai_addrlen) == 0) 957 break; 958 959 save_errno = errno; 960 close(s); 961 errno = save_errno; 962 s = -1; 963 } 964 965 if (!uflag && s != -1) { 966 if (listen(s, 1) < 0) 967 err(1, "listen"); 968 } 969 970 freeaddrinfo(res0); 971 972 return (s); 973 } 974 975 /* 976 * readwrite() 977 * Loop that polls on the network file descriptor and stdin. 978 */ 979 void 980 readwrite(int net_fd, struct tls *tls_ctx) 981 { 982 struct pollfd pfd[4]; 983 int stdin_fd = STDIN_FILENO; 984 int stdout_fd = STDOUT_FILENO; 985 unsigned char netinbuf[BUFSIZE]; 986 size_t netinbufpos = 0; 987 unsigned char stdinbuf[BUFSIZE]; 988 size_t stdinbufpos = 0; 989 int n, num_fds; 990 ssize_t ret; 991 992 /* don't read from stdin if requested */ 993 if (dflag) 994 stdin_fd = -1; 995 996 /* stdin */ 997 pfd[POLL_STDIN].fd = stdin_fd; 998 pfd[POLL_STDIN].events = POLLIN; 999 1000 /* network out */ 1001 pfd[POLL_NETOUT].fd = net_fd; 1002 pfd[POLL_NETOUT].events = 0; 1003 1004 /* network in */ 1005 pfd[POLL_NETIN].fd = net_fd; 1006 pfd[POLL_NETIN].events = POLLIN; 1007 1008 /* stdout */ 1009 pfd[POLL_STDOUT].fd = stdout_fd; 1010 pfd[POLL_STDOUT].events = 0; 1011 1012 while (1) { 1013 /* both inputs are gone, buffers are empty, we are done */ 1014 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1015 stdinbufpos == 0 && netinbufpos == 0) { 1016 close(net_fd); 1017 return; 1018 } 1019 /* both outputs are gone, we can't continue */ 1020 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 1021 close(net_fd); 1022 return; 1023 } 1024 /* listen and net in gone, queues empty, done */ 1025 if (lflag && pfd[POLL_NETIN].fd == -1 && 1026 stdinbufpos == 0 && netinbufpos == 0) { 1027 close(net_fd); 1028 return; 1029 } 1030 1031 /* help says -i is for "wait between lines sent". We read and 1032 * write arbitrary amounts of data, and we don't want to start 1033 * scanning for newlines, so this is as good as it gets */ 1034 if (iflag) 1035 sleep(iflag); 1036 1037 /* poll */ 1038 num_fds = poll(pfd, 4, timeout); 1039 1040 /* treat poll errors */ 1041 if (num_fds == -1) { 1042 close(net_fd); 1043 err(1, "polling error"); 1044 } 1045 1046 /* timeout happened */ 1047 if (num_fds == 0) 1048 return; 1049 1050 /* treat socket error conditions */ 1051 for (n = 0; n < 4; n++) { 1052 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1053 pfd[n].fd = -1; 1054 } 1055 } 1056 /* reading is possible after HUP */ 1057 if (pfd[POLL_STDIN].events & POLLIN && 1058 pfd[POLL_STDIN].revents & POLLHUP && 1059 !(pfd[POLL_STDIN].revents & POLLIN)) 1060 pfd[POLL_STDIN].fd = -1; 1061 1062 if (pfd[POLL_NETIN].events & POLLIN && 1063 pfd[POLL_NETIN].revents & POLLHUP && 1064 !(pfd[POLL_NETIN].revents & POLLIN)) 1065 pfd[POLL_NETIN].fd = -1; 1066 1067 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1068 if (Nflag) 1069 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1070 pfd[POLL_NETOUT].fd = -1; 1071 } 1072 /* if HUP, stop watching stdout */ 1073 if (pfd[POLL_STDOUT].revents & POLLHUP) 1074 pfd[POLL_STDOUT].fd = -1; 1075 /* if no net out, stop watching stdin */ 1076 if (pfd[POLL_NETOUT].fd == -1) 1077 pfd[POLL_STDIN].fd = -1; 1078 /* if no stdout, stop watching net in */ 1079 if (pfd[POLL_STDOUT].fd == -1) { 1080 if (pfd[POLL_NETIN].fd != -1) 1081 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1082 pfd[POLL_NETIN].fd = -1; 1083 } 1084 1085 /* try to read from stdin */ 1086 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1087 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1088 &stdinbufpos, NULL); 1089 if (ret == TLS_WANT_POLLIN) 1090 pfd[POLL_STDIN].events = POLLIN; 1091 else if (ret == TLS_WANT_POLLOUT) 1092 pfd[POLL_STDIN].events = POLLOUT; 1093 else if (ret == 0 || ret == -1) 1094 pfd[POLL_STDIN].fd = -1; 1095 /* read something - poll net out */ 1096 if (stdinbufpos > 0) 1097 pfd[POLL_NETOUT].events = POLLOUT; 1098 /* filled buffer - remove self from polling */ 1099 if (stdinbufpos == BUFSIZE) 1100 pfd[POLL_STDIN].events = 0; 1101 } 1102 /* try to write to network */ 1103 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1104 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1105 &stdinbufpos, tls_ctx); 1106 if (ret == TLS_WANT_POLLIN) 1107 pfd[POLL_NETOUT].events = POLLIN; 1108 else if (ret == TLS_WANT_POLLOUT) 1109 pfd[POLL_NETOUT].events = POLLOUT; 1110 else if (ret == -1) 1111 pfd[POLL_NETOUT].fd = -1; 1112 /* buffer empty - remove self from polling */ 1113 if (stdinbufpos == 0) 1114 pfd[POLL_NETOUT].events = 0; 1115 /* buffer no longer full - poll stdin again */ 1116 if (stdinbufpos < BUFSIZE) 1117 pfd[POLL_STDIN].events = POLLIN; 1118 } 1119 /* try to read from network */ 1120 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1121 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1122 &netinbufpos, tls_ctx); 1123 if (ret == TLS_WANT_POLLIN) 1124 pfd[POLL_NETIN].events = POLLIN; 1125 else if (ret == TLS_WANT_POLLOUT) 1126 pfd[POLL_NETIN].events = POLLOUT; 1127 else if (ret == -1) 1128 pfd[POLL_NETIN].fd = -1; 1129 /* eof on net in - remove from pfd */ 1130 if (ret == 0) { 1131 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1132 pfd[POLL_NETIN].fd = -1; 1133 } 1134 /* read something - poll stdout */ 1135 if (netinbufpos > 0) 1136 pfd[POLL_STDOUT].events = POLLOUT; 1137 /* filled buffer - remove self from polling */ 1138 if (netinbufpos == BUFSIZE) 1139 pfd[POLL_NETIN].events = 0; 1140 /* handle telnet */ 1141 if (tflag) 1142 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1143 netinbufpos); 1144 } 1145 /* try to write to stdout */ 1146 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1147 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1148 &netinbufpos, NULL); 1149 if (ret == TLS_WANT_POLLIN) 1150 pfd[POLL_STDOUT].events = POLLIN; 1151 else if (ret == TLS_WANT_POLLOUT) 1152 pfd[POLL_STDOUT].events = POLLOUT; 1153 else if (ret == -1) 1154 pfd[POLL_STDOUT].fd = -1; 1155 /* buffer empty - remove self from polling */ 1156 if (netinbufpos == 0) 1157 pfd[POLL_STDOUT].events = 0; 1158 /* buffer no longer full - poll net in again */ 1159 if (netinbufpos < BUFSIZE) 1160 pfd[POLL_NETIN].events = POLLIN; 1161 } 1162 1163 /* stdin gone and queue empty? */ 1164 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1165 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1166 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1167 pfd[POLL_NETOUT].fd = -1; 1168 } 1169 /* net in gone and queue empty? */ 1170 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1171 pfd[POLL_STDOUT].fd = -1; 1172 } 1173 } 1174 } 1175 1176 ssize_t 1177 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1178 { 1179 ssize_t n; 1180 ssize_t adjust; 1181 1182 if (tls) 1183 n = tls_write(tls, buf, *bufpos); 1184 else { 1185 n = write(fd, buf, *bufpos); 1186 /* don't treat EAGAIN, EINTR as error */ 1187 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1188 n = TLS_WANT_POLLOUT; 1189 } 1190 if (n <= 0) 1191 return n; 1192 /* adjust buffer */ 1193 adjust = *bufpos - n; 1194 if (adjust > 0) 1195 memmove(buf, buf + n, adjust); 1196 *bufpos -= n; 1197 return n; 1198 } 1199 1200 ssize_t 1201 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1202 { 1203 size_t num = BUFSIZE - *bufpos; 1204 ssize_t n; 1205 1206 if (tls) 1207 n = tls_read(tls, buf + *bufpos, num); 1208 else { 1209 n = read(fd, buf + *bufpos, num); 1210 /* don't treat EAGAIN, EINTR as error */ 1211 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1212 n = TLS_WANT_POLLIN; 1213 } 1214 if (n <= 0) 1215 return n; 1216 *bufpos += n; 1217 return n; 1218 } 1219 1220 /* 1221 * fdpass() 1222 * Pass the connected file descriptor to stdout and exit. 1223 */ 1224 void 1225 fdpass(int nfd) 1226 { 1227 struct msghdr mh; 1228 union { 1229 struct cmsghdr hdr; 1230 char buf[CMSG_SPACE(sizeof(int))]; 1231 } cmsgbuf; 1232 struct cmsghdr *cmsg; 1233 struct iovec iov; 1234 char c = '\0'; 1235 ssize_t r; 1236 struct pollfd pfd; 1237 1238 /* Avoid obvious stupidity */ 1239 if (isatty(STDOUT_FILENO)) 1240 errx(1, "Cannot pass file descriptor to tty"); 1241 1242 bzero(&mh, sizeof(mh)); 1243 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1244 bzero(&iov, sizeof(iov)); 1245 1246 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1247 mh.msg_controllen = sizeof(cmsgbuf.buf); 1248 cmsg = CMSG_FIRSTHDR(&mh); 1249 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1250 cmsg->cmsg_level = SOL_SOCKET; 1251 cmsg->cmsg_type = SCM_RIGHTS; 1252 *(int *)CMSG_DATA(cmsg) = nfd; 1253 1254 iov.iov_base = &c; 1255 iov.iov_len = 1; 1256 mh.msg_iov = &iov; 1257 mh.msg_iovlen = 1; 1258 1259 bzero(&pfd, sizeof(pfd)); 1260 pfd.fd = STDOUT_FILENO; 1261 pfd.events = POLLOUT; 1262 for (;;) { 1263 r = sendmsg(STDOUT_FILENO, &mh, 0); 1264 if (r == -1) { 1265 if (errno == EAGAIN || errno == EINTR) { 1266 if (poll(&pfd, 1, -1) == -1) 1267 err(1, "poll"); 1268 continue; 1269 } 1270 err(1, "sendmsg"); 1271 } else if (r != 1) 1272 errx(1, "sendmsg: unexpected return value %zd", r); 1273 else 1274 break; 1275 } 1276 exit(0); 1277 } 1278 1279 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1280 void 1281 atelnet(int nfd, unsigned char *buf, unsigned int size) 1282 { 1283 unsigned char *p, *end; 1284 unsigned char obuf[4]; 1285 1286 if (size < 3) 1287 return; 1288 end = buf + size - 2; 1289 1290 for (p = buf; p < end; p++) { 1291 if (*p != IAC) 1292 continue; 1293 1294 obuf[0] = IAC; 1295 p++; 1296 if ((*p == WILL) || (*p == WONT)) 1297 obuf[1] = DONT; 1298 else if ((*p == DO) || (*p == DONT)) 1299 obuf[1] = WONT; 1300 else 1301 continue; 1302 1303 p++; 1304 obuf[2] = *p; 1305 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1306 warn("Write Error!"); 1307 } 1308 } 1309 1310 1311 int 1312 strtoport(char *portstr, int udp) 1313 { 1314 struct servent *entry; 1315 const char *errstr; 1316 char *proto; 1317 int port = -1; 1318 1319 proto = udp ? "udp" : "tcp"; 1320 1321 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1322 if (errstr == NULL) 1323 return port; 1324 if (errno != EINVAL) 1325 errx(1, "port number %s: %s", errstr, portstr); 1326 if ((entry = getservbyname(portstr, proto)) == NULL) 1327 errx(1, "service \"%s\" unknown", portstr); 1328 return ntohs(entry->s_port); 1329 } 1330 1331 /* 1332 * build_ports() 1333 * Build an array of ports in portlist[], listing each port 1334 * that we should try to connect to. 1335 */ 1336 void 1337 build_ports(char *p) 1338 { 1339 char *n; 1340 int hi, lo, cp; 1341 int x = 0; 1342 1343 if ((n = strchr(p, '-')) != NULL) { 1344 *n = '\0'; 1345 n++; 1346 1347 /* Make sure the ports are in order: lowest->highest. */ 1348 hi = strtoport(n, uflag); 1349 lo = strtoport(p, uflag); 1350 if (lo > hi) { 1351 cp = hi; 1352 hi = lo; 1353 lo = cp; 1354 } 1355 1356 /* 1357 * Initialize portlist with a random permutation. Based on 1358 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1359 */ 1360 if (rflag) { 1361 for (x = 0; x <= hi - lo; x++) { 1362 cp = arc4random_uniform(x + 1); 1363 portlist[x] = portlist[cp]; 1364 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1365 err(1, "asprintf"); 1366 } 1367 } else { /* Load ports sequentially. */ 1368 for (cp = lo; cp <= hi; cp++) { 1369 if (asprintf(&portlist[x], "%d", cp) < 0) 1370 err(1, "asprintf"); 1371 x++; 1372 } 1373 } 1374 } else { 1375 char *tmp; 1376 1377 hi = strtoport(p, uflag); 1378 if (asprintf(&tmp, "%d", hi) != -1) 1379 portlist[0] = tmp; 1380 else 1381 err(1, NULL); 1382 } 1383 } 1384 1385 /* 1386 * udptest() 1387 * Do a few writes to see if the UDP port is there. 1388 * Fails once PF state table is full. 1389 */ 1390 int 1391 udptest(int s) 1392 { 1393 int i, ret; 1394 1395 for (i = 0; i <= 3; i++) { 1396 if (write(s, "X", 1) == 1) 1397 ret = 1; 1398 else 1399 ret = -1; 1400 } 1401 return (ret); 1402 } 1403 1404 void 1405 set_common_sockopts(int s, int af) 1406 { 1407 int x = 1; 1408 1409 if (Sflag) { 1410 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1411 &x, sizeof(x)) == -1) 1412 err(1, NULL); 1413 } 1414 if (Dflag) { 1415 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1416 &x, sizeof(x)) == -1) 1417 err(1, NULL); 1418 } 1419 if (Tflag != -1) { 1420 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1421 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1422 err(1, "set IP ToS"); 1423 1424 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1425 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1426 err(1, "set IPv6 traffic class"); 1427 } 1428 if (Iflag) { 1429 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1430 &Iflag, sizeof(Iflag)) == -1) 1431 err(1, "set TCP receive buffer size"); 1432 } 1433 if (Oflag) { 1434 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1435 &Oflag, sizeof(Oflag)) == -1) 1436 err(1, "set TCP send buffer size"); 1437 } 1438 1439 if (ttl != -1) { 1440 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1441 IP_TTL, &ttl, sizeof(ttl))) 1442 err(1, "set IP TTL"); 1443 1444 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1445 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1446 err(1, "set IPv6 unicast hops"); 1447 } 1448 1449 if (minttl != -1) { 1450 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1451 IP_MINTTL, &minttl, sizeof(minttl))) 1452 err(1, "set IP min TTL"); 1453 1454 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1455 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1456 err(1, "set IPv6 min hop count"); 1457 } 1458 } 1459 1460 int 1461 map_tos(char *s, int *val) 1462 { 1463 /* DiffServ Codepoints and other TOS mappings */ 1464 const struct toskeywords { 1465 const char *keyword; 1466 int val; 1467 } *t, toskeywords[] = { 1468 { "af11", IPTOS_DSCP_AF11 }, 1469 { "af12", IPTOS_DSCP_AF12 }, 1470 { "af13", IPTOS_DSCP_AF13 }, 1471 { "af21", IPTOS_DSCP_AF21 }, 1472 { "af22", IPTOS_DSCP_AF22 }, 1473 { "af23", IPTOS_DSCP_AF23 }, 1474 { "af31", IPTOS_DSCP_AF31 }, 1475 { "af32", IPTOS_DSCP_AF32 }, 1476 { "af33", IPTOS_DSCP_AF33 }, 1477 { "af41", IPTOS_DSCP_AF41 }, 1478 { "af42", IPTOS_DSCP_AF42 }, 1479 { "af43", IPTOS_DSCP_AF43 }, 1480 { "critical", IPTOS_PREC_CRITIC_ECP }, 1481 { "cs0", IPTOS_DSCP_CS0 }, 1482 { "cs1", IPTOS_DSCP_CS1 }, 1483 { "cs2", IPTOS_DSCP_CS2 }, 1484 { "cs3", IPTOS_DSCP_CS3 }, 1485 { "cs4", IPTOS_DSCP_CS4 }, 1486 { "cs5", IPTOS_DSCP_CS5 }, 1487 { "cs6", IPTOS_DSCP_CS6 }, 1488 { "cs7", IPTOS_DSCP_CS7 }, 1489 { "ef", IPTOS_DSCP_EF }, 1490 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1491 { "lowdelay", IPTOS_LOWDELAY }, 1492 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1493 { "reliability", IPTOS_RELIABILITY }, 1494 { "throughput", IPTOS_THROUGHPUT }, 1495 { NULL, -1 }, 1496 }; 1497 1498 for (t = toskeywords; t->keyword != NULL; t++) { 1499 if (strcmp(s, t->keyword) == 0) { 1500 *val = t->val; 1501 return (1); 1502 } 1503 } 1504 1505 return (0); 1506 } 1507 1508 int 1509 map_tls(char *s, int *val) 1510 { 1511 const struct tlskeywords { 1512 const char *keyword; 1513 int val; 1514 } *t, tlskeywords[] = { 1515 { "tlsall", TLS_ALL }, 1516 { "noverify", TLS_NOVERIFY }, 1517 { "noname", TLS_NONAME }, 1518 { "clientcert", TLS_CCERT}, 1519 { "muststaple", TLS_MUSTSTAPLE}, 1520 { NULL, -1 }, 1521 }; 1522 1523 for (t = tlskeywords; t->keyword != NULL; t++) { 1524 if (strcmp(s, t->keyword) == 0) { 1525 *val |= t->val; 1526 return (1); 1527 } 1528 } 1529 return (0); 1530 } 1531 1532 void 1533 report_tls(struct tls * tls_ctx, char * host, char *tls_expectname) 1534 { 1535 time_t t; 1536 const char *ocsp_url; 1537 1538 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1539 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1540 fprintf(stderr, "Peer name: %s\n", 1541 tls_expectname ? tls_expectname : host); 1542 if (tls_peer_cert_subject(tls_ctx)) 1543 fprintf(stderr, "Subject: %s\n", 1544 tls_peer_cert_subject(tls_ctx)); 1545 if (tls_peer_cert_issuer(tls_ctx)) 1546 fprintf(stderr, "Issuer: %s\n", 1547 tls_peer_cert_issuer(tls_ctx)); 1548 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1549 fprintf(stderr, "Valid From: %s", ctime(&t)); 1550 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1551 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1552 if (tls_peer_cert_hash(tls_ctx)) 1553 fprintf(stderr, "Cert Hash: %s\n", 1554 tls_peer_cert_hash(tls_ctx)); 1555 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1556 if (ocsp_url != NULL) 1557 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1558 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1559 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1560 fprintf(stderr, "OCSP Stapling: %s\n", 1561 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1562 tls_peer_ocsp_result(tls_ctx)); 1563 fprintf(stderr, 1564 " response_status=%d cert_status=%d crl_reason=%d\n", 1565 tls_peer_ocsp_response_status(tls_ctx), 1566 tls_peer_ocsp_cert_status(tls_ctx), 1567 tls_peer_ocsp_crl_reason(tls_ctx)); 1568 t = tls_peer_ocsp_this_update(tls_ctx); 1569 fprintf(stderr, " this update: %s", 1570 t != -1 ? ctime(&t) : "\n"); 1571 t = tls_peer_ocsp_next_update(tls_ctx); 1572 fprintf(stderr, " next update: %s", 1573 t != -1 ? ctime(&t) : "\n"); 1574 t = tls_peer_ocsp_revocation_time(tls_ctx); 1575 fprintf(stderr, " revocation: %s", 1576 t != -1 ? ctime(&t) : "\n"); 1577 break; 1578 case -1: 1579 break; 1580 default: 1581 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1582 tls_peer_ocsp_response_status(tls_ctx), 1583 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1584 tls_peer_ocsp_result(tls_ctx)); 1585 break; 1586 1587 } 1588 } 1589 1590 void 1591 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1592 { 1593 char remote_host[NI_MAXHOST]; 1594 char remote_port[NI_MAXSERV]; 1595 int herr; 1596 int flags = NI_NUMERICSERV; 1597 1598 if (path != NULL) { 1599 fprintf(stderr, "Connection on %s received!\n", path); 1600 return; 1601 } 1602 1603 if (nflag) 1604 flags |= NI_NUMERICHOST; 1605 1606 if ((herr = getnameinfo(sa, salen, 1607 remote_host, sizeof(remote_host), 1608 remote_port, sizeof(remote_port), 1609 flags)) != 0) { 1610 if (herr == EAI_SYSTEM) 1611 err(1, "getnameinfo"); 1612 else 1613 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1614 } 1615 1616 fprintf(stderr, 1617 "Connection from %s %s " 1618 "received!\n", remote_host, remote_port); 1619 } 1620 1621 void 1622 help(void) 1623 { 1624 usage(0); 1625 fprintf(stderr, "\tCommand Summary:\n\ 1626 \t-4 Use IPv4\n\ 1627 \t-6 Use IPv6\n\ 1628 \t-C certfile Public key file\n\ 1629 \t-c Use TLS\n\ 1630 \t-D Enable the debug socket option\n\ 1631 \t-d Detach from stdin\n\ 1632 \t-e name\t Required name in peer certificate\n\ 1633 \t-F Pass socket fd\n\ 1634 \t-H hash\t Hash string of peer certificate\n\ 1635 \t-h This help text\n\ 1636 \t-I length TCP receive buffer length\n\ 1637 \t-i interval Delay interval for lines sent, ports scanned\n\ 1638 \t-K keyfile Private key file\n\ 1639 \t-k Keep inbound sockets open for multiple connects\n\ 1640 \t-l Listen mode, for inbound connects\n\ 1641 \t-M ttl Outgoing TTL / Hop Limit\n\ 1642 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1643 \t-N Shutdown the network socket after EOF on stdin\n\ 1644 \t-n Suppress name/port resolutions\n\ 1645 \t-O length TCP send buffer length\n\ 1646 \t-o staplefile Staple file\n\ 1647 \t-P proxyuser\tUsername for proxy authentication\n\ 1648 \t-p port\t Specify local port for remote connects\n\ 1649 \t-R CAfile CA bundle\n\ 1650 \t-r Randomize remote ports\n\ 1651 \t-S Enable the TCP MD5 signature option\n\ 1652 \t-s source Local source address\n\ 1653 \t-T keyword TOS value or TLS options\n\ 1654 \t-t Answer TELNET negotiation\n\ 1655 \t-U Use UNIX domain socket\n\ 1656 \t-u UDP mode\n\ 1657 \t-V rtable Specify alternate routing table\n\ 1658 \t-v Verbose\n\ 1659 \t-w timeout Timeout for connects and final net reads\n\ 1660 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1661 \t-x addr[:port]\tSpecify proxy address and port\n\ 1662 \t-z Zero-I/O mode [used for scanning]\n\ 1663 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1664 exit(1); 1665 } 1666 1667 void 1668 usage(int ret) 1669 { 1670 fprintf(stderr, 1671 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1672 "[-H hash] [-I length]\n" 1673 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1674 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1675 "[-R CAfile]\n" 1676 "\t [-s source] [-T keyword] [-V rtable] [-w timeout] " 1677 "[-X proxy_protocol]\n" 1678 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1679 if (ret) 1680 exit(1); 1681 } 1682