1 /* $OpenBSD: netcat.c,v 1.177 2017/02/09 22:55:45 bluhm Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org> 4 * Copyright (c) 2015 Bob Beck. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * Re-written nc(1) for OpenBSD. Original implementation by 32 * *Hobbit* <hobbit@avian.org>. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 40 #include <netinet/in.h> 41 #include <netinet/tcp.h> 42 #include <netinet/ip.h> 43 #include <arpa/telnet.h> 44 45 #include <err.h> 46 #include <errno.h> 47 #include <limits.h> 48 #include <netdb.h> 49 #include <poll.h> 50 #include <signal.h> 51 #include <stdarg.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <time.h> 56 #include <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_tls(int, struct tls *, int (*)(struct tls *)); 125 int timeout_connect(int, const struct sockaddr *, socklen_t); 126 int socks_connect(const char *, const char *, struct addrinfo, 127 const char *, const char *, struct addrinfo, int, const char *); 128 int udptest(int); 129 int unix_bind(char *, int); 130 int unix_connect(char *); 131 int unix_listen(char *); 132 void set_common_sockopts(int, int); 133 int map_tos(char *, int *); 134 int map_tls(char *, int *); 135 void report_connect(const struct sockaddr *, socklen_t, char *); 136 void report_tls(struct tls *tls_ctx, char * host, char *tls_expectname); 137 void usage(int); 138 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 139 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 140 void tls_setup_client(struct tls *, int, char *); 141 struct tls *tls_setup_server(struct tls *, int, char *); 142 143 int 144 main(int argc, char *argv[]) 145 { 146 int ch, s = -1, ret, socksv; 147 char *host, *uport; 148 struct addrinfo hints; 149 struct servent *sv; 150 socklen_t len; 151 struct sockaddr_storage cliaddr; 152 char *proxy, *proxyport = NULL; 153 const char *errstr; 154 struct addrinfo proxyhints; 155 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 156 struct tls_config *tls_cfg = NULL; 157 struct tls *tls_ctx = NULL; 158 159 ret = 1; 160 socksv = 5; 161 host = NULL; 162 uport = NULL; 163 sv = NULL; 164 165 signal(SIGPIPE, SIG_IGN); 166 167 while ((ch = getopt(argc, argv, 168 "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:R:rSs:T:tUuV:vw:X:x:z")) != -1) { 169 switch (ch) { 170 case '4': 171 family = AF_INET; 172 break; 173 case '6': 174 family = AF_INET6; 175 break; 176 case 'U': 177 family = AF_UNIX; 178 break; 179 case 'X': 180 if (strcasecmp(optarg, "connect") == 0) 181 socksv = -1; /* HTTP proxy CONNECT */ 182 else if (strcmp(optarg, "4") == 0) 183 socksv = 4; /* SOCKS v.4 */ 184 else if (strcmp(optarg, "5") == 0) 185 socksv = 5; /* SOCKS v.5 */ 186 else 187 errx(1, "unsupported proxy protocol"); 188 break; 189 case 'C': 190 Cflag = optarg; 191 break; 192 case 'c': 193 usetls = 1; 194 break; 195 case 'd': 196 dflag = 1; 197 break; 198 case 'e': 199 tls_expectname = optarg; 200 break; 201 case 'F': 202 Fflag = 1; 203 break; 204 case 'H': 205 tls_expecthash = optarg; 206 break; 207 case 'h': 208 help(); 209 break; 210 case 'i': 211 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 212 if (errstr) 213 errx(1, "interval %s: %s", errstr, optarg); 214 break; 215 case 'K': 216 Kflag = optarg; 217 break; 218 case 'k': 219 kflag = 1; 220 break; 221 case 'l': 222 lflag = 1; 223 break; 224 case 'M': 225 ttl = strtonum(optarg, 0, 255, &errstr); 226 if (errstr) 227 errx(1, "ttl is %s", errstr); 228 break; 229 case 'm': 230 minttl = strtonum(optarg, 0, 255, &errstr); 231 if (errstr) 232 errx(1, "minttl is %s", errstr); 233 break; 234 case 'N': 235 Nflag = 1; 236 break; 237 case 'n': 238 nflag = 1; 239 break; 240 case 'P': 241 Pflag = optarg; 242 break; 243 case 'p': 244 pflag = optarg; 245 break; 246 case 'R': 247 tls_cachanged = 1; 248 Rflag = optarg; 249 break; 250 case 'r': 251 rflag = 1; 252 break; 253 case 's': 254 sflag = optarg; 255 break; 256 case 't': 257 tflag = 1; 258 break; 259 case 'u': 260 uflag = 1; 261 break; 262 case 'V': 263 rtableid = (int)strtonum(optarg, 0, 264 RT_TABLEID_MAX, &errstr); 265 if (errstr) 266 errx(1, "rtable %s: %s", errstr, optarg); 267 break; 268 case 'v': 269 vflag = 1; 270 break; 271 case 'w': 272 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 273 if (errstr) 274 errx(1, "timeout %s: %s", errstr, optarg); 275 timeout *= 1000; 276 break; 277 case 'x': 278 xflag = 1; 279 if ((proxy = strdup(optarg)) == NULL) 280 err(1, NULL); 281 break; 282 case 'z': 283 zflag = 1; 284 break; 285 case 'D': 286 Dflag = 1; 287 break; 288 case 'I': 289 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 290 if (errstr != NULL) 291 errx(1, "TCP receive window %s: %s", 292 errstr, optarg); 293 break; 294 case 'O': 295 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 296 if (errstr != NULL) 297 errx(1, "TCP send window %s: %s", 298 errstr, optarg); 299 break; 300 case 'o': 301 oflag = optarg; 302 break; 303 case 'S': 304 Sflag = 1; 305 break; 306 case 'T': 307 errstr = NULL; 308 errno = 0; 309 if (map_tos(optarg, &Tflag)) 310 break; 311 if (map_tls(optarg, &TLSopt)) 312 break; 313 if (strlen(optarg) > 1 && optarg[0] == '0' && 314 optarg[1] == 'x') 315 Tflag = (int)strtol(optarg, NULL, 16); 316 else 317 Tflag = (int)strtonum(optarg, 0, 255, 318 &errstr); 319 if (Tflag < 0 || Tflag > 255 || errstr || errno) 320 errx(1, "illegal tos/tls value %s", optarg); 321 break; 322 default: 323 usage(1); 324 } 325 } 326 argc -= optind; 327 argv += optind; 328 329 if (rtableid >= 0) 330 if (setrtable(rtableid) == -1) 331 err(1, "setrtable"); 332 333 if (family == AF_UNIX) { 334 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 335 err(1, "pledge"); 336 } else if (Fflag) { 337 if (Pflag) { 338 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 339 err(1, "pledge"); 340 } else if (pledge("stdio inet dns sendfd", NULL) == -1) 341 err(1, "pledge"); 342 } else if (Pflag) { 343 if (pledge("stdio inet dns tty", NULL) == -1) 344 err(1, "pledge"); 345 } else if (usetls) { 346 if (pledge("stdio rpath inet dns", NULL) == -1) 347 err(1, "pledge"); 348 } else if (pledge("stdio inet dns", NULL) == -1) 349 err(1, "pledge"); 350 351 /* Cruft to make sure options are clean, and used properly. */ 352 if (argv[0] && !argv[1] && family == AF_UNIX) { 353 host = argv[0]; 354 uport = NULL; 355 } else if (argv[0] && !argv[1]) { 356 if (!lflag) 357 usage(1); 358 uport = argv[0]; 359 host = NULL; 360 } else if (argv[0] && argv[1]) { 361 host = argv[0]; 362 uport = argv[1]; 363 } else 364 usage(1); 365 366 if (lflag && sflag) 367 errx(1, "cannot use -s and -l"); 368 if (lflag && pflag) 369 errx(1, "cannot use -p and -l"); 370 if (lflag && zflag) 371 errx(1, "cannot use -z and -l"); 372 if (!lflag && kflag) 373 errx(1, "must use -l with -k"); 374 if (uflag && usetls) 375 errx(1, "cannot use -c and -u"); 376 if ((family == AF_UNIX) && usetls) 377 errx(1, "cannot use -c and -U"); 378 if ((family == AF_UNIX) && Fflag) 379 errx(1, "cannot use -F and -U"); 380 if (Fflag && usetls) 381 errx(1, "cannot use -c and -F"); 382 if (TLSopt && !usetls) 383 errx(1, "you must specify -c to use TLS options"); 384 if (Cflag && !usetls) 385 errx(1, "you must specify -c to use -C"); 386 if (Kflag && !usetls) 387 errx(1, "you must specify -c to use -K"); 388 if (oflag && !Cflag) 389 errx(1, "you must specify -C to use -o"); 390 if (tls_cachanged && !usetls) 391 errx(1, "you must specify -c to use -R"); 392 if (tls_expecthash && !usetls) 393 errx(1, "you must specify -c to use -H"); 394 if (tls_expectname && !usetls) 395 errx(1, "you must specify -c to use -e"); 396 397 /* Get name of temporary socket for unix datagram client */ 398 if ((family == AF_UNIX) && uflag && !lflag) { 399 if (sflag) { 400 unix_dg_tmp_socket = sflag; 401 } else { 402 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 403 UNIX_DG_TMP_SOCKET_SIZE); 404 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 405 err(1, "mktemp"); 406 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 407 } 408 } 409 410 /* Initialize addrinfo structure. */ 411 if (family != AF_UNIX) { 412 memset(&hints, 0, sizeof(struct addrinfo)); 413 hints.ai_family = family; 414 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 415 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 416 if (nflag) 417 hints.ai_flags |= AI_NUMERICHOST; 418 } 419 420 if (xflag) { 421 if (uflag) 422 errx(1, "no proxy support for UDP mode"); 423 424 if (lflag) 425 errx(1, "no proxy support for listen"); 426 427 if (family == AF_UNIX) 428 errx(1, "no proxy support for unix sockets"); 429 430 if (sflag) 431 errx(1, "no proxy support for local source address"); 432 433 if (*proxy == '[') { 434 ++proxy; 435 proxyport = strchr(proxy, ']'); 436 if (proxyport == NULL) 437 errx(1, "missing closing bracket in proxy"); 438 *proxyport++ = '\0'; 439 if (*proxyport == '\0') 440 /* Use default proxy port. */ 441 proxyport = NULL; 442 else { 443 if (*proxyport == ':') 444 ++proxyport; 445 else 446 errx(1, "garbage proxy port delimiter"); 447 } 448 } else { 449 proxyport = strrchr(proxy, ':'); 450 if (proxyport != NULL) 451 *proxyport++ = '\0'; 452 } 453 454 memset(&proxyhints, 0, sizeof(struct addrinfo)); 455 proxyhints.ai_family = family; 456 proxyhints.ai_socktype = SOCK_STREAM; 457 proxyhints.ai_protocol = IPPROTO_TCP; 458 if (nflag) 459 proxyhints.ai_flags |= AI_NUMERICHOST; 460 } 461 462 if (usetls) { 463 if (Pflag) { 464 if (pledge("stdio inet dns tty rpath", NULL) == -1) 465 err(1, "pledge"); 466 } else if (pledge("stdio inet dns rpath", NULL) == -1) 467 err(1, "pledge"); 468 469 if (tls_init() == -1) 470 errx(1, "unable to initialize TLS"); 471 if ((tls_cfg = tls_config_new()) == NULL) 472 errx(1, "unable to allocate TLS config"); 473 if (Rflag && tls_config_set_ca_file(tls_cfg, Rflag) == -1) 474 errx(1, "%s", tls_config_error(tls_cfg)); 475 if (Cflag && tls_config_set_cert_file(tls_cfg, Cflag) == -1) 476 errx(1, "%s", tls_config_error(tls_cfg)); 477 if (Kflag && tls_config_set_key_file(tls_cfg, Kflag) == -1) 478 errx(1, "%s", tls_config_error(tls_cfg)); 479 if (oflag && tls_config_set_ocsp_staple_file(tls_cfg, oflag) == -1) 480 errx(1, "%s", tls_config_error(tls_cfg)); 481 if (TLSopt & TLS_ALL) { 482 if (tls_config_set_protocols(tls_cfg, 483 TLS_PROTOCOLS_ALL) != 0) 484 errx(1, "%s", tls_config_error(tls_cfg)); 485 if (tls_config_set_ciphers(tls_cfg, "all") != 0) 486 errx(1, "%s", tls_config_error(tls_cfg)); 487 } 488 if (!lflag && (TLSopt & TLS_CCERT)) 489 errx(1, "clientcert is only valid with -l"); 490 if (TLSopt & TLS_NONAME) 491 tls_config_insecure_noverifyname(tls_cfg); 492 if (TLSopt & TLS_NOVERIFY) { 493 if (tls_expecthash != NULL) 494 errx(1, "-H and -T noverify may not be used" 495 "together"); 496 tls_config_insecure_noverifycert(tls_cfg); 497 } 498 if (TLSopt & TLS_MUSTSTAPLE) 499 tls_config_ocsp_require_stapling(tls_cfg); 500 501 if (Pflag) { 502 if (pledge("stdio inet dns tty", NULL) == -1) 503 err(1, "pledge"); 504 } else if (pledge("stdio inet dns", NULL) == -1) 505 err(1, "pledge"); 506 } 507 if (lflag) { 508 struct tls *tls_cctx = NULL; 509 int connfd; 510 ret = 0; 511 512 if (family == AF_UNIX) { 513 if (uflag) 514 s = unix_bind(host, 0); 515 else 516 s = unix_listen(host); 517 } 518 519 if (usetls) { 520 tls_config_verify_client_optional(tls_cfg); 521 if ((tls_ctx = tls_server()) == NULL) 522 errx(1, "tls server creation failed"); 523 if (tls_configure(tls_ctx, tls_cfg) == -1) 524 errx(1, "tls configuration failed (%s)", 525 tls_error(tls_ctx)); 526 } 527 /* Allow only one connection at a time, but stay alive. */ 528 for (;;) { 529 if (family != AF_UNIX) 530 s = local_listen(host, uport, hints); 531 if (s < 0) 532 err(1, NULL); 533 /* 534 * For UDP and -k, don't connect the socket, let it 535 * receive datagrams from multiple socket pairs. 536 */ 537 if (uflag && kflag) 538 readwrite(s, NULL); 539 /* 540 * For UDP and not -k, we will use recvfrom() initially 541 * to wait for a caller, then use the regular functions 542 * to talk to the caller. 543 */ 544 else if (uflag && !kflag) { 545 int rv, plen; 546 char buf[16384]; 547 struct sockaddr_storage z; 548 549 len = sizeof(z); 550 plen = 2048; 551 rv = recvfrom(s, buf, plen, MSG_PEEK, 552 (struct sockaddr *)&z, &len); 553 if (rv < 0) 554 err(1, "recvfrom"); 555 556 rv = connect(s, (struct sockaddr *)&z, len); 557 if (rv < 0) 558 err(1, "connect"); 559 560 if (vflag) 561 report_connect((struct sockaddr *)&z, len, NULL); 562 563 readwrite(s, NULL); 564 } else { 565 len = sizeof(cliaddr); 566 connfd = accept4(s, (struct sockaddr *)&cliaddr, 567 &len, SOCK_NONBLOCK); 568 if (connfd == -1) { 569 /* For now, all errnos are fatal */ 570 err(1, "accept"); 571 } 572 if (vflag) 573 report_connect((struct sockaddr *)&cliaddr, len, 574 family == AF_UNIX ? host : NULL); 575 if ((usetls) && 576 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 577 readwrite(connfd, tls_cctx); 578 if (!usetls) 579 readwrite(connfd, NULL); 580 if (tls_cctx) { 581 timeout_tls(s, tls_cctx, tls_close); 582 tls_free(tls_cctx); 583 tls_cctx = NULL; 584 } 585 close(connfd); 586 } 587 if (family != AF_UNIX) 588 close(s); 589 else if (uflag) { 590 if (connect(s, NULL, 0) < 0) 591 err(1, "connect"); 592 } 593 594 if (!kflag) 595 break; 596 } 597 } else if (family == AF_UNIX) { 598 ret = 0; 599 600 if ((s = unix_connect(host)) > 0) { 601 if (!zflag) 602 readwrite(s, NULL); 603 close(s); 604 } else 605 ret = 1; 606 607 if (uflag) 608 unlink(unix_dg_tmp_socket); 609 exit(ret); 610 611 } else { 612 int i = 0; 613 614 /* Construct the portlist[] array. */ 615 build_ports(uport); 616 617 /* Cycle through portlist, connecting to each port. */ 618 for (s = -1, i = 0; portlist[i] != NULL; i++) { 619 if (s != -1) 620 close(s); 621 622 if (usetls) { 623 if ((tls_ctx = tls_client()) == NULL) 624 errx(1, "tls client creation failed"); 625 if (tls_configure(tls_ctx, tls_cfg) == -1) 626 errx(1, "tls configuration failed (%s)", 627 tls_error(tls_ctx)); 628 } 629 if (xflag) 630 s = socks_connect(host, portlist[i], hints, 631 proxy, proxyport, proxyhints, socksv, 632 Pflag); 633 else 634 s = remote_connect(host, portlist[i], hints); 635 636 if (s == -1) 637 continue; 638 639 ret = 0; 640 if (vflag || zflag) { 641 /* For UDP, make sure we are connected. */ 642 if (uflag) { 643 if (udptest(s) == -1) { 644 ret = 1; 645 continue; 646 } 647 } 648 649 /* Don't look up port if -n. */ 650 if (nflag) 651 sv = NULL; 652 else { 653 sv = getservbyport( 654 ntohs(atoi(portlist[i])), 655 uflag ? "udp" : "tcp"); 656 } 657 658 fprintf(stderr, 659 "Connection to %s %s port [%s/%s] " 660 "succeeded!\n", host, portlist[i], 661 uflag ? "udp" : "tcp", 662 sv ? sv->s_name : "*"); 663 } 664 if (Fflag) 665 fdpass(s); 666 else { 667 if (usetls) 668 tls_setup_client(tls_ctx, s, host); 669 if (!zflag) 670 readwrite(s, tls_ctx); 671 if (tls_ctx) { 672 timeout_tls(s, tls_ctx, tls_close); 673 tls_free(tls_ctx); 674 tls_ctx = NULL; 675 } 676 } 677 } 678 } 679 680 if (s != -1) 681 close(s); 682 683 tls_config_free(tls_cfg); 684 685 exit(ret); 686 } 687 688 /* 689 * unix_bind() 690 * Returns a unix socket bound to the given path 691 */ 692 int 693 unix_bind(char *path, int flags) 694 { 695 struct sockaddr_un s_un; 696 int s, save_errno; 697 698 /* Create unix domain socket. */ 699 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 700 0)) < 0) 701 return (-1); 702 703 memset(&s_un, 0, sizeof(struct sockaddr_un)); 704 s_un.sun_family = AF_UNIX; 705 706 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 707 sizeof(s_un.sun_path)) { 708 close(s); 709 errno = ENAMETOOLONG; 710 return (-1); 711 } 712 713 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 714 save_errno = errno; 715 close(s); 716 errno = save_errno; 717 return (-1); 718 } 719 return (s); 720 } 721 722 int 723 timeout_tls(int s, struct tls *tls_ctx, int (*func)(struct tls *)) 724 { 725 struct pollfd pfd; 726 int ret; 727 728 while ((ret = (*func)(tls_ctx)) != 0) { 729 if (ret == TLS_WANT_POLLIN) 730 pfd.events = POLLIN; 731 else if (ret == TLS_WANT_POLLOUT) 732 pfd.events = POLLOUT; 733 else 734 break; 735 pfd.fd = s; 736 if ((ret = poll(&pfd, 1, timeout)) == 1) 737 continue; 738 else if (ret == 0) { 739 errno = ETIMEDOUT; 740 ret = -1; 741 break; 742 } else 743 err(1, "poll failed"); 744 } 745 746 return (ret); 747 } 748 749 void 750 tls_setup_client(struct tls *tls_ctx, int s, char *host) 751 { 752 const char *errstr; 753 754 if (tls_connect_socket(tls_ctx, s, 755 tls_expectname ? tls_expectname : host) == -1) { 756 errx(1, "tls connection failed (%s)", 757 tls_error(tls_ctx)); 758 } 759 if (timeout_tls(s, tls_ctx, tls_handshake) == -1) { 760 if ((errstr = tls_error(tls_ctx)) == NULL) 761 errstr = strerror(errno); 762 errx(1, "tls handshake failed (%s)", errstr); 763 } 764 if (vflag) 765 report_tls(tls_ctx, host, tls_expectname); 766 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 767 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 768 errx(1, "peer certificate is not %s", tls_expecthash); 769 } 770 771 struct tls * 772 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 773 { 774 struct tls *tls_cctx; 775 const char *errstr; 776 777 if (tls_accept_socket(tls_ctx, &tls_cctx, connfd) == -1) { 778 warnx("tls accept failed (%s)", tls_error(tls_ctx)); 779 } else if (timeout_tls(connfd, tls_cctx, tls_handshake) == -1) { 780 if ((errstr = tls_error(tls_ctx)) == NULL) 781 errstr = strerror(errno); 782 warnx("tls handshake failed (%s)", errstr); 783 } else { 784 int gotcert = tls_peer_cert_provided(tls_cctx); 785 786 if (vflag && gotcert) 787 report_tls(tls_cctx, host, tls_expectname); 788 if ((TLSopt & TLS_CCERT) && !gotcert) 789 warnx("No client certificate provided"); 790 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 791 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 792 warnx("peer certificate is not %s", tls_expecthash); 793 else if (gotcert && tls_expectname && 794 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 795 warnx("name (%s) not found in client cert", 796 tls_expectname); 797 else { 798 return tls_cctx; 799 } 800 } 801 return NULL; 802 } 803 804 /* 805 * unix_connect() 806 * Returns a socket connected to a local unix socket. Returns -1 on failure. 807 */ 808 int 809 unix_connect(char *path) 810 { 811 struct sockaddr_un s_un; 812 int s, save_errno; 813 814 if (uflag) { 815 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 816 return (-1); 817 } else { 818 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 819 return (-1); 820 } 821 822 memset(&s_un, 0, sizeof(struct sockaddr_un)); 823 s_un.sun_family = AF_UNIX; 824 825 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 826 sizeof(s_un.sun_path)) { 827 close(s); 828 errno = ENAMETOOLONG; 829 return (-1); 830 } 831 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 832 save_errno = errno; 833 close(s); 834 errno = save_errno; 835 return (-1); 836 } 837 return (s); 838 839 } 840 841 /* 842 * unix_listen() 843 * Create a unix domain socket, and listen on it. 844 */ 845 int 846 unix_listen(char *path) 847 { 848 int s; 849 if ((s = unix_bind(path, 0)) < 0) 850 return (-1); 851 852 if (listen(s, 5) < 0) { 853 close(s); 854 return (-1); 855 } 856 return (s); 857 } 858 859 /* 860 * remote_connect() 861 * Returns a socket connected to a remote host. Properly binds to a local 862 * port or source address if needed. Returns -1 on failure. 863 */ 864 int 865 remote_connect(const char *host, const char *port, struct addrinfo hints) 866 { 867 struct addrinfo *res, *res0; 868 int s = -1, error, on = 1, save_errno; 869 870 if ((error = getaddrinfo(host, port, &hints, &res0))) 871 errx(1, "getaddrinfo for host \"%s\" port %s: %s", host, 872 port, gai_strerror(error)); 873 874 for (res = res0; res; res = res->ai_next) { 875 if ((s = socket(res->ai_family, res->ai_socktype | 876 SOCK_NONBLOCK, res->ai_protocol)) < 0) 877 continue; 878 879 /* Bind to a local port or source address if specified. */ 880 if (sflag || pflag) { 881 struct addrinfo ahints, *ares; 882 883 /* try SO_BINDANY, but don't insist */ 884 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 885 memset(&ahints, 0, sizeof(struct addrinfo)); 886 ahints.ai_family = res->ai_family; 887 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 888 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 889 ahints.ai_flags = AI_PASSIVE; 890 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 891 errx(1, "getaddrinfo: %s", gai_strerror(error)); 892 893 if (bind(s, (struct sockaddr *)ares->ai_addr, 894 ares->ai_addrlen) < 0) 895 err(1, "bind failed"); 896 freeaddrinfo(ares); 897 } 898 899 set_common_sockopts(s, res->ai_family); 900 901 if (timeout_connect(s, res->ai_addr, res->ai_addrlen) == 0) 902 break; 903 if (vflag) 904 warn("connect to %s port %s (%s) failed", host, port, 905 uflag ? "udp" : "tcp"); 906 907 save_errno = errno; 908 close(s); 909 errno = save_errno; 910 s = -1; 911 } 912 913 freeaddrinfo(res0); 914 915 return (s); 916 } 917 918 int 919 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 920 { 921 struct pollfd pfd; 922 socklen_t optlen; 923 int optval; 924 int ret; 925 926 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 927 pfd.fd = s; 928 pfd.events = POLLOUT; 929 if ((ret = poll(&pfd, 1, timeout)) == 1) { 930 optlen = sizeof(optval); 931 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 932 &optval, &optlen)) == 0) { 933 errno = optval; 934 ret = optval == 0 ? 0 : -1; 935 } 936 } else if (ret == 0) { 937 errno = ETIMEDOUT; 938 ret = -1; 939 } else 940 err(1, "poll failed"); 941 } 942 943 return (ret); 944 } 945 946 /* 947 * local_listen() 948 * Returns a socket listening on a local port, binds to specified source 949 * address. Returns -1 on failure. 950 */ 951 int 952 local_listen(char *host, char *port, struct addrinfo hints) 953 { 954 struct addrinfo *res, *res0; 955 int s = -1, ret, x = 1, save_errno; 956 int error; 957 958 /* Allow nodename to be null. */ 959 hints.ai_flags |= AI_PASSIVE; 960 961 /* 962 * In the case of binding to a wildcard address 963 * default to binding to an ipv4 address. 964 */ 965 if (host == NULL && hints.ai_family == AF_UNSPEC) 966 hints.ai_family = AF_INET; 967 968 if ((error = getaddrinfo(host, port, &hints, &res0))) 969 errx(1, "getaddrinfo: %s", gai_strerror(error)); 970 971 for (res = res0; res; res = res->ai_next) { 972 if ((s = socket(res->ai_family, res->ai_socktype, 973 res->ai_protocol)) < 0) 974 continue; 975 976 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 977 if (ret == -1) 978 err(1, NULL); 979 980 set_common_sockopts(s, res->ai_family); 981 982 if (bind(s, (struct sockaddr *)res->ai_addr, 983 res->ai_addrlen) == 0) 984 break; 985 986 save_errno = errno; 987 close(s); 988 errno = save_errno; 989 s = -1; 990 } 991 992 if (!uflag && s != -1) { 993 if (listen(s, 1) < 0) 994 err(1, "listen"); 995 } 996 997 freeaddrinfo(res0); 998 999 return (s); 1000 } 1001 1002 /* 1003 * readwrite() 1004 * Loop that polls on the network file descriptor and stdin. 1005 */ 1006 void 1007 readwrite(int net_fd, struct tls *tls_ctx) 1008 { 1009 struct pollfd pfd[4]; 1010 int stdin_fd = STDIN_FILENO; 1011 int stdout_fd = STDOUT_FILENO; 1012 unsigned char netinbuf[BUFSIZE]; 1013 size_t netinbufpos = 0; 1014 unsigned char stdinbuf[BUFSIZE]; 1015 size_t stdinbufpos = 0; 1016 int n, num_fds; 1017 ssize_t ret; 1018 1019 /* don't read from stdin if requested */ 1020 if (dflag) 1021 stdin_fd = -1; 1022 1023 /* stdin */ 1024 pfd[POLL_STDIN].fd = stdin_fd; 1025 pfd[POLL_STDIN].events = POLLIN; 1026 1027 /* network out */ 1028 pfd[POLL_NETOUT].fd = net_fd; 1029 pfd[POLL_NETOUT].events = 0; 1030 1031 /* network in */ 1032 pfd[POLL_NETIN].fd = net_fd; 1033 pfd[POLL_NETIN].events = POLLIN; 1034 1035 /* stdout */ 1036 pfd[POLL_STDOUT].fd = stdout_fd; 1037 pfd[POLL_STDOUT].events = 0; 1038 1039 while (1) { 1040 /* both inputs are gone, buffers are empty, we are done */ 1041 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1042 stdinbufpos == 0 && netinbufpos == 0) 1043 return; 1044 /* both outputs are gone, we can't continue */ 1045 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) 1046 return; 1047 /* listen and net in gone, queues empty, done */ 1048 if (lflag && pfd[POLL_NETIN].fd == -1 && 1049 stdinbufpos == 0 && netinbufpos == 0) 1050 return; 1051 1052 /* help says -i is for "wait between lines sent". We read and 1053 * write arbitrary amounts of data, and we don't want to start 1054 * scanning for newlines, so this is as good as it gets */ 1055 if (iflag) 1056 sleep(iflag); 1057 1058 /* poll */ 1059 num_fds = poll(pfd, 4, timeout); 1060 1061 /* treat poll errors */ 1062 if (num_fds == -1) 1063 err(1, "polling error"); 1064 1065 /* timeout happened */ 1066 if (num_fds == 0) 1067 return; 1068 1069 /* treat socket error conditions */ 1070 for (n = 0; n < 4; n++) { 1071 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1072 pfd[n].fd = -1; 1073 } 1074 } 1075 /* reading is possible after HUP */ 1076 if (pfd[POLL_STDIN].events & POLLIN && 1077 pfd[POLL_STDIN].revents & POLLHUP && 1078 !(pfd[POLL_STDIN].revents & POLLIN)) 1079 pfd[POLL_STDIN].fd = -1; 1080 1081 if (pfd[POLL_NETIN].events & POLLIN && 1082 pfd[POLL_NETIN].revents & POLLHUP && 1083 !(pfd[POLL_NETIN].revents & POLLIN)) 1084 pfd[POLL_NETIN].fd = -1; 1085 1086 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1087 if (Nflag) 1088 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1089 pfd[POLL_NETOUT].fd = -1; 1090 } 1091 /* if HUP, stop watching stdout */ 1092 if (pfd[POLL_STDOUT].revents & POLLHUP) 1093 pfd[POLL_STDOUT].fd = -1; 1094 /* if no net out, stop watching stdin */ 1095 if (pfd[POLL_NETOUT].fd == -1) 1096 pfd[POLL_STDIN].fd = -1; 1097 /* if no stdout, stop watching net in */ 1098 if (pfd[POLL_STDOUT].fd == -1) { 1099 if (pfd[POLL_NETIN].fd != -1) 1100 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1101 pfd[POLL_NETIN].fd = -1; 1102 } 1103 1104 /* try to read from stdin */ 1105 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1106 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1107 &stdinbufpos, NULL); 1108 if (ret == TLS_WANT_POLLIN) 1109 pfd[POLL_STDIN].events = POLLIN; 1110 else if (ret == TLS_WANT_POLLOUT) 1111 pfd[POLL_STDIN].events = POLLOUT; 1112 else if (ret == 0 || ret == -1) 1113 pfd[POLL_STDIN].fd = -1; 1114 /* read something - poll net out */ 1115 if (stdinbufpos > 0) 1116 pfd[POLL_NETOUT].events = POLLOUT; 1117 /* filled buffer - remove self from polling */ 1118 if (stdinbufpos == BUFSIZE) 1119 pfd[POLL_STDIN].events = 0; 1120 } 1121 /* try to write to network */ 1122 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1123 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1124 &stdinbufpos, tls_ctx); 1125 if (ret == TLS_WANT_POLLIN) 1126 pfd[POLL_NETOUT].events = POLLIN; 1127 else if (ret == TLS_WANT_POLLOUT) 1128 pfd[POLL_NETOUT].events = POLLOUT; 1129 else if (ret == -1) 1130 pfd[POLL_NETOUT].fd = -1; 1131 /* buffer empty - remove self from polling */ 1132 if (stdinbufpos == 0) 1133 pfd[POLL_NETOUT].events = 0; 1134 /* buffer no longer full - poll stdin again */ 1135 if (stdinbufpos < BUFSIZE) 1136 pfd[POLL_STDIN].events = POLLIN; 1137 } 1138 /* try to read from network */ 1139 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1140 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1141 &netinbufpos, tls_ctx); 1142 if (ret == TLS_WANT_POLLIN) 1143 pfd[POLL_NETIN].events = POLLIN; 1144 else if (ret == TLS_WANT_POLLOUT) 1145 pfd[POLL_NETIN].events = POLLOUT; 1146 else if (ret == -1) 1147 pfd[POLL_NETIN].fd = -1; 1148 /* eof on net in - remove from pfd */ 1149 if (ret == 0) { 1150 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1151 pfd[POLL_NETIN].fd = -1; 1152 } 1153 /* read something - poll stdout */ 1154 if (netinbufpos > 0) 1155 pfd[POLL_STDOUT].events = POLLOUT; 1156 /* filled buffer - remove self from polling */ 1157 if (netinbufpos == BUFSIZE) 1158 pfd[POLL_NETIN].events = 0; 1159 /* handle telnet */ 1160 if (tflag) 1161 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1162 netinbufpos); 1163 } 1164 /* try to write to stdout */ 1165 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1166 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1167 &netinbufpos, NULL); 1168 if (ret == TLS_WANT_POLLIN) 1169 pfd[POLL_STDOUT].events = POLLIN; 1170 else if (ret == TLS_WANT_POLLOUT) 1171 pfd[POLL_STDOUT].events = POLLOUT; 1172 else if (ret == -1) 1173 pfd[POLL_STDOUT].fd = -1; 1174 /* buffer empty - remove self from polling */ 1175 if (netinbufpos == 0) 1176 pfd[POLL_STDOUT].events = 0; 1177 /* buffer no longer full - poll net in again */ 1178 if (netinbufpos < BUFSIZE) 1179 pfd[POLL_NETIN].events = POLLIN; 1180 } 1181 1182 /* stdin gone and queue empty? */ 1183 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1184 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1185 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1186 pfd[POLL_NETOUT].fd = -1; 1187 } 1188 /* net in gone and queue empty? */ 1189 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1190 pfd[POLL_STDOUT].fd = -1; 1191 } 1192 } 1193 } 1194 1195 ssize_t 1196 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1197 { 1198 ssize_t n; 1199 ssize_t adjust; 1200 1201 if (tls) 1202 n = tls_write(tls, buf, *bufpos); 1203 else { 1204 n = write(fd, buf, *bufpos); 1205 /* don't treat EAGAIN, EINTR as error */ 1206 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1207 n = TLS_WANT_POLLOUT; 1208 } 1209 if (n <= 0) 1210 return n; 1211 /* adjust buffer */ 1212 adjust = *bufpos - n; 1213 if (adjust > 0) 1214 memmove(buf, buf + n, adjust); 1215 *bufpos -= n; 1216 return n; 1217 } 1218 1219 ssize_t 1220 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1221 { 1222 size_t num = BUFSIZE - *bufpos; 1223 ssize_t n; 1224 1225 if (tls) 1226 n = tls_read(tls, buf + *bufpos, num); 1227 else { 1228 n = read(fd, buf + *bufpos, num); 1229 /* don't treat EAGAIN, EINTR as error */ 1230 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1231 n = TLS_WANT_POLLIN; 1232 } 1233 if (n <= 0) 1234 return n; 1235 *bufpos += n; 1236 return n; 1237 } 1238 1239 /* 1240 * fdpass() 1241 * Pass the connected file descriptor to stdout and exit. 1242 */ 1243 void 1244 fdpass(int nfd) 1245 { 1246 struct msghdr mh; 1247 union { 1248 struct cmsghdr hdr; 1249 char buf[CMSG_SPACE(sizeof(int))]; 1250 } cmsgbuf; 1251 struct cmsghdr *cmsg; 1252 struct iovec iov; 1253 char c = '\0'; 1254 ssize_t r; 1255 struct pollfd pfd; 1256 1257 /* Avoid obvious stupidity */ 1258 if (isatty(STDOUT_FILENO)) 1259 errx(1, "Cannot pass file descriptor to tty"); 1260 1261 bzero(&mh, sizeof(mh)); 1262 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1263 bzero(&iov, sizeof(iov)); 1264 1265 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1266 mh.msg_controllen = sizeof(cmsgbuf.buf); 1267 cmsg = CMSG_FIRSTHDR(&mh); 1268 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1269 cmsg->cmsg_level = SOL_SOCKET; 1270 cmsg->cmsg_type = SCM_RIGHTS; 1271 *(int *)CMSG_DATA(cmsg) = nfd; 1272 1273 iov.iov_base = &c; 1274 iov.iov_len = 1; 1275 mh.msg_iov = &iov; 1276 mh.msg_iovlen = 1; 1277 1278 bzero(&pfd, sizeof(pfd)); 1279 pfd.fd = STDOUT_FILENO; 1280 pfd.events = POLLOUT; 1281 for (;;) { 1282 r = sendmsg(STDOUT_FILENO, &mh, 0); 1283 if (r == -1) { 1284 if (errno == EAGAIN || errno == EINTR) { 1285 if (poll(&pfd, 1, -1) == -1) 1286 err(1, "poll"); 1287 continue; 1288 } 1289 err(1, "sendmsg"); 1290 } else if (r != 1) 1291 errx(1, "sendmsg: unexpected return value %zd", r); 1292 else 1293 break; 1294 } 1295 exit(0); 1296 } 1297 1298 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1299 void 1300 atelnet(int nfd, unsigned char *buf, unsigned int size) 1301 { 1302 unsigned char *p, *end; 1303 unsigned char obuf[4]; 1304 1305 if (size < 3) 1306 return; 1307 end = buf + size - 2; 1308 1309 for (p = buf; p < end; p++) { 1310 if (*p != IAC) 1311 continue; 1312 1313 obuf[0] = IAC; 1314 p++; 1315 if ((*p == WILL) || (*p == WONT)) 1316 obuf[1] = DONT; 1317 else if ((*p == DO) || (*p == DONT)) 1318 obuf[1] = WONT; 1319 else 1320 continue; 1321 1322 p++; 1323 obuf[2] = *p; 1324 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1325 warn("Write Error!"); 1326 } 1327 } 1328 1329 1330 int 1331 strtoport(char *portstr, int udp) 1332 { 1333 struct servent *entry; 1334 const char *errstr; 1335 char *proto; 1336 int port = -1; 1337 1338 proto = udp ? "udp" : "tcp"; 1339 1340 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1341 if (errstr == NULL) 1342 return port; 1343 if (errno != EINVAL) 1344 errx(1, "port number %s: %s", errstr, portstr); 1345 if ((entry = getservbyname(portstr, proto)) == NULL) 1346 errx(1, "service \"%s\" unknown", portstr); 1347 return ntohs(entry->s_port); 1348 } 1349 1350 /* 1351 * build_ports() 1352 * Build an array of ports in portlist[], listing each port 1353 * that we should try to connect to. 1354 */ 1355 void 1356 build_ports(char *p) 1357 { 1358 char *n; 1359 int hi, lo, cp; 1360 int x = 0; 1361 1362 if ((n = strchr(p, '-')) != NULL) { 1363 *n = '\0'; 1364 n++; 1365 1366 /* Make sure the ports are in order: lowest->highest. */ 1367 hi = strtoport(n, uflag); 1368 lo = strtoport(p, uflag); 1369 if (lo > hi) { 1370 cp = hi; 1371 hi = lo; 1372 lo = cp; 1373 } 1374 1375 /* 1376 * Initialize portlist with a random permutation. Based on 1377 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1378 */ 1379 if (rflag) { 1380 for (x = 0; x <= hi - lo; x++) { 1381 cp = arc4random_uniform(x + 1); 1382 portlist[x] = portlist[cp]; 1383 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1384 err(1, "asprintf"); 1385 } 1386 } else { /* Load ports sequentially. */ 1387 for (cp = lo; cp <= hi; cp++) { 1388 if (asprintf(&portlist[x], "%d", cp) < 0) 1389 err(1, "asprintf"); 1390 x++; 1391 } 1392 } 1393 } else { 1394 char *tmp; 1395 1396 hi = strtoport(p, uflag); 1397 if (asprintf(&tmp, "%d", hi) != -1) 1398 portlist[0] = tmp; 1399 else 1400 err(1, NULL); 1401 } 1402 } 1403 1404 /* 1405 * udptest() 1406 * Do a few writes to see if the UDP port is there. 1407 * Fails once PF state table is full. 1408 */ 1409 int 1410 udptest(int s) 1411 { 1412 int i, ret; 1413 1414 for (i = 0; i <= 3; i++) { 1415 if (write(s, "X", 1) == 1) 1416 ret = 1; 1417 else 1418 ret = -1; 1419 } 1420 return (ret); 1421 } 1422 1423 void 1424 set_common_sockopts(int s, int af) 1425 { 1426 int x = 1; 1427 1428 if (Sflag) { 1429 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1430 &x, sizeof(x)) == -1) 1431 err(1, NULL); 1432 } 1433 if (Dflag) { 1434 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1435 &x, sizeof(x)) == -1) 1436 err(1, NULL); 1437 } 1438 if (Tflag != -1) { 1439 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1440 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1441 err(1, "set IP ToS"); 1442 1443 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1444 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1445 err(1, "set IPv6 traffic class"); 1446 } 1447 if (Iflag) { 1448 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1449 &Iflag, sizeof(Iflag)) == -1) 1450 err(1, "set TCP receive buffer size"); 1451 } 1452 if (Oflag) { 1453 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1454 &Oflag, sizeof(Oflag)) == -1) 1455 err(1, "set TCP send buffer size"); 1456 } 1457 1458 if (ttl != -1) { 1459 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1460 IP_TTL, &ttl, sizeof(ttl))) 1461 err(1, "set IP TTL"); 1462 1463 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1464 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1465 err(1, "set IPv6 unicast hops"); 1466 } 1467 1468 if (minttl != -1) { 1469 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1470 IP_MINTTL, &minttl, sizeof(minttl))) 1471 err(1, "set IP min TTL"); 1472 1473 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1474 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1475 err(1, "set IPv6 min hop count"); 1476 } 1477 } 1478 1479 int 1480 map_tos(char *s, int *val) 1481 { 1482 /* DiffServ Codepoints and other TOS mappings */ 1483 const struct toskeywords { 1484 const char *keyword; 1485 int val; 1486 } *t, toskeywords[] = { 1487 { "af11", IPTOS_DSCP_AF11 }, 1488 { "af12", IPTOS_DSCP_AF12 }, 1489 { "af13", IPTOS_DSCP_AF13 }, 1490 { "af21", IPTOS_DSCP_AF21 }, 1491 { "af22", IPTOS_DSCP_AF22 }, 1492 { "af23", IPTOS_DSCP_AF23 }, 1493 { "af31", IPTOS_DSCP_AF31 }, 1494 { "af32", IPTOS_DSCP_AF32 }, 1495 { "af33", IPTOS_DSCP_AF33 }, 1496 { "af41", IPTOS_DSCP_AF41 }, 1497 { "af42", IPTOS_DSCP_AF42 }, 1498 { "af43", IPTOS_DSCP_AF43 }, 1499 { "critical", IPTOS_PREC_CRITIC_ECP }, 1500 { "cs0", IPTOS_DSCP_CS0 }, 1501 { "cs1", IPTOS_DSCP_CS1 }, 1502 { "cs2", IPTOS_DSCP_CS2 }, 1503 { "cs3", IPTOS_DSCP_CS3 }, 1504 { "cs4", IPTOS_DSCP_CS4 }, 1505 { "cs5", IPTOS_DSCP_CS5 }, 1506 { "cs6", IPTOS_DSCP_CS6 }, 1507 { "cs7", IPTOS_DSCP_CS7 }, 1508 { "ef", IPTOS_DSCP_EF }, 1509 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1510 { "lowdelay", IPTOS_LOWDELAY }, 1511 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1512 { "reliability", IPTOS_RELIABILITY }, 1513 { "throughput", IPTOS_THROUGHPUT }, 1514 { NULL, -1 }, 1515 }; 1516 1517 for (t = toskeywords; t->keyword != NULL; t++) { 1518 if (strcmp(s, t->keyword) == 0) { 1519 *val = t->val; 1520 return (1); 1521 } 1522 } 1523 1524 return (0); 1525 } 1526 1527 int 1528 map_tls(char *s, int *val) 1529 { 1530 const struct tlskeywords { 1531 const char *keyword; 1532 int val; 1533 } *t, tlskeywords[] = { 1534 { "tlsall", TLS_ALL }, 1535 { "noverify", TLS_NOVERIFY }, 1536 { "noname", TLS_NONAME }, 1537 { "clientcert", TLS_CCERT}, 1538 { "muststaple", TLS_MUSTSTAPLE}, 1539 { NULL, -1 }, 1540 }; 1541 1542 for (t = tlskeywords; t->keyword != NULL; t++) { 1543 if (strcmp(s, t->keyword) == 0) { 1544 *val |= t->val; 1545 return (1); 1546 } 1547 } 1548 return (0); 1549 } 1550 1551 void 1552 report_tls(struct tls * tls_ctx, char * host, char *tls_expectname) 1553 { 1554 time_t t; 1555 const char *ocsp_url; 1556 1557 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1558 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1559 fprintf(stderr, "Peer name: %s\n", 1560 tls_expectname ? tls_expectname : host); 1561 if (tls_peer_cert_subject(tls_ctx)) 1562 fprintf(stderr, "Subject: %s\n", 1563 tls_peer_cert_subject(tls_ctx)); 1564 if (tls_peer_cert_issuer(tls_ctx)) 1565 fprintf(stderr, "Issuer: %s\n", 1566 tls_peer_cert_issuer(tls_ctx)); 1567 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1568 fprintf(stderr, "Valid From: %s", ctime(&t)); 1569 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1570 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1571 if (tls_peer_cert_hash(tls_ctx)) 1572 fprintf(stderr, "Cert Hash: %s\n", 1573 tls_peer_cert_hash(tls_ctx)); 1574 ocsp_url = tls_peer_ocsp_url(tls_ctx); 1575 if (ocsp_url != NULL) 1576 fprintf(stderr, "OCSP URL: %s\n", ocsp_url); 1577 switch (tls_peer_ocsp_response_status(tls_ctx)) { 1578 case TLS_OCSP_RESPONSE_SUCCESSFUL: 1579 fprintf(stderr, "OCSP Stapling: %s\n", 1580 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1581 tls_peer_ocsp_result(tls_ctx)); 1582 fprintf(stderr, 1583 " response_status=%d cert_status=%d crl_reason=%d\n", 1584 tls_peer_ocsp_response_status(tls_ctx), 1585 tls_peer_ocsp_cert_status(tls_ctx), 1586 tls_peer_ocsp_crl_reason(tls_ctx)); 1587 t = tls_peer_ocsp_this_update(tls_ctx); 1588 fprintf(stderr, " this update: %s", 1589 t != -1 ? ctime(&t) : "\n"); 1590 t = tls_peer_ocsp_next_update(tls_ctx); 1591 fprintf(stderr, " next update: %s", 1592 t != -1 ? ctime(&t) : "\n"); 1593 t = tls_peer_ocsp_revocation_time(tls_ctx); 1594 fprintf(stderr, " revocation: %s", 1595 t != -1 ? ctime(&t) : "\n"); 1596 break; 1597 case -1: 1598 break; 1599 default: 1600 fprintf(stderr, "OCSP Stapling: failure - response_status %d (%s)\n", 1601 tls_peer_ocsp_response_status(tls_ctx), 1602 tls_peer_ocsp_result(tls_ctx) == NULL ? "" : 1603 tls_peer_ocsp_result(tls_ctx)); 1604 break; 1605 1606 } 1607 } 1608 1609 void 1610 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1611 { 1612 char remote_host[NI_MAXHOST]; 1613 char remote_port[NI_MAXSERV]; 1614 int herr; 1615 int flags = NI_NUMERICSERV; 1616 1617 if (path != NULL) { 1618 fprintf(stderr, "Connection on %s received!\n", path); 1619 return; 1620 } 1621 1622 if (nflag) 1623 flags |= NI_NUMERICHOST; 1624 1625 if ((herr = getnameinfo(sa, salen, 1626 remote_host, sizeof(remote_host), 1627 remote_port, sizeof(remote_port), 1628 flags)) != 0) { 1629 if (herr == EAI_SYSTEM) 1630 err(1, "getnameinfo"); 1631 else 1632 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1633 } 1634 1635 fprintf(stderr, 1636 "Connection from %s %s " 1637 "received!\n", remote_host, remote_port); 1638 } 1639 1640 void 1641 help(void) 1642 { 1643 usage(0); 1644 fprintf(stderr, "\tCommand Summary:\n\ 1645 \t-4 Use IPv4\n\ 1646 \t-6 Use IPv6\n\ 1647 \t-C certfile Public key file\n\ 1648 \t-c Use TLS\n\ 1649 \t-D Enable the debug socket option\n\ 1650 \t-d Detach from stdin\n\ 1651 \t-e name\t Required name in peer certificate\n\ 1652 \t-F Pass socket fd\n\ 1653 \t-H hash\t Hash string of peer certificate\n\ 1654 \t-h This help text\n\ 1655 \t-I length TCP receive buffer length\n\ 1656 \t-i interval Delay interval for lines sent, ports scanned\n\ 1657 \t-K keyfile Private key file\n\ 1658 \t-k Keep inbound sockets open for multiple connects\n\ 1659 \t-l Listen mode, for inbound connects\n\ 1660 \t-M ttl Outgoing TTL / Hop Limit\n\ 1661 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1662 \t-N Shutdown the network socket after EOF on stdin\n\ 1663 \t-n Suppress name/port resolutions\n\ 1664 \t-O length TCP send buffer length\n\ 1665 \t-o staplefile Staple file\n\ 1666 \t-P proxyuser\tUsername for proxy authentication\n\ 1667 \t-p port\t Specify local port for remote connects\n\ 1668 \t-R CAfile CA bundle\n\ 1669 \t-r Randomize remote ports\n\ 1670 \t-S Enable the TCP MD5 signature option\n\ 1671 \t-s source Local source address\n\ 1672 \t-T keyword TOS value or TLS options\n\ 1673 \t-t Answer TELNET negotiation\n\ 1674 \t-U Use UNIX domain socket\n\ 1675 \t-u UDP mode\n\ 1676 \t-V rtable Specify alternate routing table\n\ 1677 \t-v Verbose\n\ 1678 \t-w timeout Timeout for connects and final net reads\n\ 1679 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1680 \t-x addr[:port]\tSpecify proxy address and port\n\ 1681 \t-z Zero-I/O mode [used for scanning]\n\ 1682 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1683 exit(1); 1684 } 1685 1686 void 1687 usage(int ret) 1688 { 1689 fprintf(stderr, 1690 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1691 "[-H hash] [-I length]\n" 1692 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1693 "\t [-o staplefile] [-P proxy_username] [-p source_port] " 1694 "[-R CAfile]\n" 1695 "\t [-s source] [-T keyword] [-V rtable] [-w timeout] " 1696 "[-X proxy_protocol]\n" 1697 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1698 if (ret) 1699 exit(1); 1700 } 1701