1 /* $OpenBSD: netcat.c,v 1.159 2016/07/07 14:09:44 jsing Exp $ */ 2 /* 3 * Copyright (c) 2001 Eric Jackson <ericj@monkey.org> 4 * Copyright (c) 2015 Bob Beck. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 /* 31 * Re-written nc(1) for OpenBSD. Original implementation by 32 * *Hobbit* <hobbit@avian.org>. 33 */ 34 35 #include <sys/types.h> 36 #include <sys/socket.h> 37 #include <sys/uio.h> 38 #include <sys/un.h> 39 40 #include <netinet/in.h> 41 #include <netinet/tcp.h> 42 #include <netinet/ip.h> 43 #include <arpa/telnet.h> 44 45 #include <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 #ifndef DEFAULT_CA_FILE 69 #define DEFAULT_CA_FILE "/etc/ssl/cert.pem" 70 #endif 71 72 #define TLS_LEGACY (1 << 1) 73 #define TLS_NOVERIFY (1 << 2) 74 #define TLS_NONAME (1 << 3) 75 #define TLS_CCERT (1 << 4) 76 77 /* Command Line Options */ 78 int dflag; /* detached, no stdin */ 79 int Fflag; /* fdpass sock to stdout */ 80 unsigned int iflag; /* Interval Flag */ 81 int kflag; /* More than one connect */ 82 int lflag; /* Bind to local port */ 83 int Nflag; /* shutdown() network socket */ 84 int nflag; /* Don't do name look up */ 85 char *Pflag; /* Proxy username */ 86 char *pflag; /* Localport flag */ 87 int rflag; /* Random ports flag */ 88 char *sflag; /* Source Address */ 89 int tflag; /* Telnet Emulation */ 90 int uflag; /* UDP - Default to TCP */ 91 int vflag; /* Verbosity */ 92 int xflag; /* Socks proxy */ 93 int zflag; /* Port Scan Flag */ 94 int Dflag; /* sodebug */ 95 int Iflag; /* TCP receive buffer size */ 96 int Oflag; /* TCP send buffer size */ 97 #ifdef TCP_MD5SIG 98 int Sflag; /* TCP MD5 signature option */ 99 #endif 100 int Tflag = -1; /* IP Type of Service */ 101 #ifdef SO_RTABLE 102 int rtableid = -1; 103 #endif 104 105 int usetls; /* use TLS */ 106 char *Cflag; /* Public cert file */ 107 char *Kflag; /* Private key file */ 108 char *Rflag = DEFAULT_CA_FILE; /* Root CA file */ 109 int tls_cachanged; /* Using non-default CA file */ 110 int TLSopt; /* TLS options */ 111 char *tls_expectname; /* required name in peer cert */ 112 char *tls_expecthash; /* required hash of peer cert */ 113 uint8_t *cacert; 114 size_t cacertlen; 115 uint8_t *privkey; 116 size_t privkeylen; 117 uint8_t *pubcert; 118 size_t pubcertlen; 119 120 int timeout = -1; 121 int family = AF_UNSPEC; 122 char *portlist[PORT_MAX+1]; 123 char *unix_dg_tmp_socket; 124 int ttl = -1; 125 int minttl = -1; 126 127 void atelnet(int, unsigned char *, unsigned int); 128 void build_ports(char *); 129 void help(void); 130 int local_listen(char *, char *, struct addrinfo); 131 void readwrite(int, struct tls *); 132 void fdpass(int nfd) __attribute__((noreturn)); 133 int remote_connect(const char *, const char *, struct addrinfo); 134 int timeout_connect(int, const struct sockaddr *, socklen_t); 135 int socks_connect(const char *, const char *, struct addrinfo, 136 const char *, const char *, struct addrinfo, int, const char *); 137 int udptest(int); 138 int unix_bind(char *, int); 139 int unix_connect(char *); 140 int unix_listen(char *); 141 void set_common_sockopts(int, int); 142 int map_tos(char *, int *); 143 int map_tls(char *, int *); 144 void report_connect(const struct sockaddr *, socklen_t, char *); 145 void report_tls(struct tls *tls_ctx, char * host, char *tls_expectname); 146 void usage(int); 147 ssize_t drainbuf(int, unsigned char *, size_t *, struct tls *); 148 ssize_t fillbuf(int, unsigned char *, size_t *, struct tls *); 149 void tls_setup_client(struct tls *, int, char *); 150 struct tls *tls_setup_server(struct tls *, int, char *); 151 152 int 153 main(int argc, char *argv[]) 154 { 155 int ch, s = -1, ret, socksv; 156 char *host, *uport; 157 struct addrinfo hints; 158 struct servent *sv; 159 socklen_t len; 160 struct sockaddr_storage cliaddr; 161 char *proxy = NULL; 162 const char *errstr, *proxyhost = "", *proxyport = NULL; 163 struct addrinfo proxyhints; 164 char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE]; 165 struct tls_config *tls_cfg = NULL; 166 struct tls *tls_ctx = NULL; 167 168 ret = 1; 169 socksv = 5; 170 host = NULL; 171 uport = NULL; 172 sv = NULL; 173 174 signal(SIGPIPE, SIG_IGN); 175 176 while ((ch = getopt(argc, argv, 177 "46C:cDde:FH:hI:i:K:klM:m:NnO:P:p:R:rSs:T:tUuV:vw:X:x:z")) != -1) { 178 switch (ch) { 179 case '4': 180 family = AF_INET; 181 break; 182 case '6': 183 family = AF_INET6; 184 break; 185 case 'U': 186 family = AF_UNIX; 187 break; 188 case 'X': 189 if (strcasecmp(optarg, "connect") == 0) 190 socksv = -1; /* HTTP proxy CONNECT */ 191 else if (strcmp(optarg, "4") == 0) 192 socksv = 4; /* SOCKS v.4 */ 193 else if (strcmp(optarg, "5") == 0) 194 socksv = 5; /* SOCKS v.5 */ 195 else 196 errx(1, "unsupported proxy protocol"); 197 break; 198 case 'C': 199 Cflag = optarg; 200 break; 201 case 'c': 202 usetls = 1; 203 break; 204 case 'd': 205 dflag = 1; 206 break; 207 case 'e': 208 tls_expectname = optarg; 209 break; 210 case 'F': 211 Fflag = 1; 212 break; 213 case 'H': 214 tls_expecthash = optarg; 215 break; 216 case 'h': 217 help(); 218 break; 219 case 'i': 220 iflag = strtonum(optarg, 0, UINT_MAX, &errstr); 221 if (errstr) 222 errx(1, "interval %s: %s", errstr, optarg); 223 break; 224 case 'K': 225 Kflag = optarg; 226 break; 227 case 'k': 228 kflag = 1; 229 break; 230 case 'l': 231 lflag = 1; 232 break; 233 case 'M': 234 ttl = strtonum(optarg, 0, 255, &errstr); 235 if (errstr) 236 errx(1, "ttl is %s", errstr); 237 break; 238 case 'm': 239 minttl = strtonum(optarg, 0, 255, &errstr); 240 if (errstr) 241 errx(1, "minttl is %s", errstr); 242 break; 243 case 'N': 244 Nflag = 1; 245 break; 246 case 'n': 247 nflag = 1; 248 break; 249 case 'P': 250 Pflag = optarg; 251 break; 252 case 'p': 253 pflag = optarg; 254 break; 255 case 'R': 256 tls_cachanged = 1; 257 Rflag = optarg; 258 break; 259 case 'r': 260 rflag = 1; 261 break; 262 case 's': 263 sflag = optarg; 264 break; 265 case 't': 266 tflag = 1; 267 break; 268 case 'u': 269 uflag = 1; 270 break; 271 #ifdef SO_RTABLE 272 case 'V': 273 rtableid = (int)strtonum(optarg, 0, 274 RT_TABLEID_MAX, &errstr); 275 if (errstr) 276 errx(1, "rtable %s: %s", errstr, optarg); 277 break; 278 #endif 279 case 'v': 280 vflag = 1; 281 break; 282 case 'w': 283 timeout = strtonum(optarg, 0, INT_MAX / 1000, &errstr); 284 if (errstr) 285 errx(1, "timeout %s: %s", errstr, optarg); 286 timeout *= 1000; 287 break; 288 case 'x': 289 xflag = 1; 290 if ((proxy = strdup(optarg)) == NULL) 291 err(1, NULL); 292 break; 293 case 'z': 294 zflag = 1; 295 break; 296 case 'D': 297 Dflag = 1; 298 break; 299 case 'I': 300 Iflag = strtonum(optarg, 1, 65536 << 14, &errstr); 301 if (errstr != NULL) 302 errx(1, "TCP receive window %s: %s", 303 errstr, optarg); 304 break; 305 case 'O': 306 Oflag = strtonum(optarg, 1, 65536 << 14, &errstr); 307 if (errstr != NULL) 308 errx(1, "TCP send window %s: %s", 309 errstr, optarg); 310 break; 311 #ifdef TCP_MD5SIG 312 case 'S': 313 Sflag = 1; 314 break; 315 #endif 316 case 'T': 317 errstr = NULL; 318 errno = 0; 319 if (map_tos(optarg, &Tflag)) 320 break; 321 if (map_tls(optarg, &TLSopt)) 322 break; 323 if (strlen(optarg) > 1 && optarg[0] == '0' && 324 optarg[1] == 'x') 325 Tflag = (int)strtol(optarg, NULL, 16); 326 else 327 Tflag = (int)strtonum(optarg, 0, 255, 328 &errstr); 329 if (Tflag < 0 || Tflag > 255 || errstr || errno) 330 errx(1, "illegal tos/tls value %s", optarg); 331 break; 332 default: 333 usage(1); 334 } 335 } 336 argc -= optind; 337 argv += optind; 338 339 #ifdef SO_RTABLE 340 if (rtableid >= 0) 341 if (setrtable(rtableid) == -1) 342 err(1, "setrtable"); 343 #endif 344 345 if (family == AF_UNIX) { 346 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 347 err(1, "pledge"); 348 } else if (Fflag) { 349 if (Pflag) { 350 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 351 err(1, "pledge"); 352 } else if (pledge("stdio inet dns sendfd", NULL) == -1) 353 err(1, "pledge"); 354 } else if (Pflag) { 355 if (pledge("stdio inet dns tty", NULL) == -1) 356 err(1, "pledge"); 357 } else if (usetls) { 358 if (pledge("stdio rpath inet dns", NULL) == -1) 359 err(1, "pledge"); 360 } else if (pledge("stdio inet dns", NULL) == -1) 361 err(1, "pledge"); 362 363 /* Cruft to make sure options are clean, and used properly. */ 364 if (argv[0] && !argv[1] && family == AF_UNIX) { 365 host = argv[0]; 366 uport = NULL; 367 } else if (argv[0] && !argv[1]) { 368 if (!lflag) 369 usage(1); 370 uport = argv[0]; 371 host = NULL; 372 } else if (argv[0] && argv[1]) { 373 host = argv[0]; 374 uport = argv[1]; 375 } else 376 usage(1); 377 378 if (lflag && sflag) 379 errx(1, "cannot use -s and -l"); 380 if (lflag && pflag) 381 errx(1, "cannot use -p and -l"); 382 if (lflag && zflag) 383 errx(1, "cannot use -z and -l"); 384 if (!lflag && kflag) 385 errx(1, "must use -l with -k"); 386 if (uflag && usetls) 387 errx(1, "cannot use -c and -u"); 388 if ((family == AF_UNIX) && usetls) 389 errx(1, "cannot use -c and -U"); 390 if ((family == AF_UNIX) && Fflag) 391 errx(1, "cannot use -F and -U"); 392 if (Fflag && usetls) 393 errx(1, "cannot use -c and -F"); 394 if (TLSopt && !usetls) 395 errx(1, "you must specify -c to use TLS options"); 396 if (Cflag && !usetls) 397 errx(1, "you must specify -c to use -C"); 398 if (Kflag && !usetls) 399 errx(1, "you must specify -c to use -K"); 400 if (tls_cachanged && !usetls) 401 errx(1, "you must specify -c to use -R"); 402 if (tls_expecthash && !usetls) 403 errx(1, "you must specify -c to use -H"); 404 if (tls_expectname && !usetls) 405 errx(1, "you must specify -c to use -e"); 406 407 /* Get name of temporary socket for unix datagram client */ 408 if ((family == AF_UNIX) && uflag && !lflag) { 409 if (sflag) { 410 unix_dg_tmp_socket = sflag; 411 } else { 412 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 413 UNIX_DG_TMP_SOCKET_SIZE); 414 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 415 err(1, "mktemp"); 416 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 417 } 418 } 419 420 /* Initialize addrinfo structure. */ 421 if (family != AF_UNIX) { 422 memset(&hints, 0, sizeof(struct addrinfo)); 423 hints.ai_family = family; 424 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 425 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 426 if (nflag) 427 hints.ai_flags |= AI_NUMERICHOST; 428 } 429 430 if (xflag) { 431 if (uflag) 432 errx(1, "no proxy support for UDP mode"); 433 434 if (lflag) 435 errx(1, "no proxy support for listen"); 436 437 if (family == AF_UNIX) 438 errx(1, "no proxy support for unix sockets"); 439 440 /* XXX IPv6 transport to proxy would probably work */ 441 if (family == AF_INET6) 442 errx(1, "no proxy support for IPv6"); 443 444 if (sflag) 445 errx(1, "no proxy support for local source address"); 446 447 proxyhost = strsep(&proxy, ":"); 448 proxyport = proxy; 449 450 memset(&proxyhints, 0, sizeof(struct addrinfo)); 451 proxyhints.ai_family = family; 452 proxyhints.ai_socktype = SOCK_STREAM; 453 proxyhints.ai_protocol = IPPROTO_TCP; 454 if (nflag) 455 proxyhints.ai_flags |= AI_NUMERICHOST; 456 } 457 458 if (usetls) { 459 if (Rflag && (cacert = tls_load_file(Rflag, &cacertlen, NULL)) == NULL) 460 errx(1, "unable to load root CA file %s", Rflag); 461 if (Cflag && (pubcert = tls_load_file(Cflag, &pubcertlen, NULL)) == NULL) 462 errx(1, "unable to load TLS certificate file %s", Cflag); 463 if (Kflag && (privkey = tls_load_file(Kflag, &privkeylen, NULL)) == NULL) 464 errx(1, "unable to load TLS key file %s", Kflag); 465 466 if (Pflag) { 467 if (pledge("stdio inet dns tty", NULL) == -1) 468 err(1, "pledge"); 469 } else if (pledge("stdio inet dns", NULL) == -1) 470 err(1, "pledge"); 471 472 if (tls_init() == -1) 473 errx(1, "unable to initialize TLS"); 474 if ((tls_cfg = tls_config_new()) == NULL) 475 errx(1, "unable to allocate TLS config"); 476 if (Rflag && tls_config_set_ca_mem(tls_cfg, cacert, cacertlen) == -1) 477 errx(1, "unable to set root CA file %s", Rflag); 478 if (Cflag && tls_config_set_cert_mem(tls_cfg, pubcert, pubcertlen) == -1) 479 errx(1, "unable to set TLS certificate file %s", Cflag); 480 if (Kflag && tls_config_set_key_mem(tls_cfg, privkey, privkeylen) == -1) 481 errx(1, "unable to set TLS key file %s", Kflag); 482 if (TLSopt & TLS_LEGACY) { 483 tls_config_set_protocols(tls_cfg, TLS_PROTOCOLS_ALL); 484 tls_config_set_ciphers(tls_cfg, "all"); 485 } 486 if (!lflag && (TLSopt & TLS_CCERT)) 487 errx(1, "clientcert is only valid with -l"); 488 if (TLSopt & TLS_NONAME) 489 tls_config_insecure_noverifyname(tls_cfg); 490 if (TLSopt & TLS_NOVERIFY) { 491 if (tls_expecthash != NULL) 492 errx(1, "-H and -T noverify may not be used" 493 "together"); 494 tls_config_insecure_noverifycert(tls_cfg); 495 } else { 496 if (Rflag && access(Rflag, R_OK) == -1) 497 errx(1, "unable to find root CA file %s", Rflag); 498 } 499 } 500 if (lflag) { 501 struct tls *tls_cctx = NULL; 502 int connfd; 503 ret = 0; 504 505 if (family == AF_UNIX) { 506 if (uflag) 507 s = unix_bind(host, 0); 508 else 509 s = unix_listen(host); 510 } 511 512 if (usetls) { 513 tls_config_verify_client_optional(tls_cfg); 514 if ((tls_ctx = tls_server()) == NULL) 515 errx(1, "tls server creation failed"); 516 if (tls_configure(tls_ctx, tls_cfg) == -1) 517 errx(1, "tls configuration failed (%s)", 518 tls_error(tls_ctx)); 519 } 520 /* Allow only one connection at a time, but stay alive. */ 521 for (;;) { 522 if (family != AF_UNIX) 523 s = local_listen(host, uport, hints); 524 if (s < 0) 525 err(1, NULL); 526 /* 527 * For UDP and -k, don't connect the socket, let it 528 * receive datagrams from multiple socket pairs. 529 */ 530 if (uflag && kflag) 531 readwrite(s, NULL); 532 /* 533 * For UDP and not -k, we will use recvfrom() initially 534 * to wait for a caller, then use the regular functions 535 * to talk to the caller. 536 */ 537 else if (uflag && !kflag) { 538 int rv, plen; 539 char buf[16384]; 540 struct sockaddr_storage z; 541 542 len = sizeof(z); 543 plen = 2048; 544 rv = recvfrom(s, buf, plen, MSG_PEEK, 545 (struct sockaddr *)&z, &len); 546 if (rv < 0) 547 err(1, "recvfrom"); 548 549 rv = connect(s, (struct sockaddr *)&z, len); 550 if (rv < 0) 551 err(1, "connect"); 552 553 if (vflag) 554 report_connect((struct sockaddr *)&z, len, NULL); 555 556 readwrite(s, NULL); 557 } else { 558 len = sizeof(cliaddr); 559 connfd = accept4(s, (struct sockaddr *)&cliaddr, 560 &len, SOCK_NONBLOCK); 561 if (connfd == -1) { 562 /* For now, all errnos are fatal */ 563 err(1, "accept"); 564 } 565 if (vflag) 566 report_connect((struct sockaddr *)&cliaddr, len, 567 family == AF_UNIX ? host : NULL); 568 if ((usetls) && 569 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 570 readwrite(connfd, tls_cctx); 571 if (!usetls) 572 readwrite(connfd, NULL); 573 if (tls_cctx) { 574 int i; 575 576 do { 577 i = tls_close(tls_cctx); 578 } while (i == TLS_WANT_POLLIN || 579 i == TLS_WANT_POLLOUT); 580 tls_free(tls_cctx); 581 tls_cctx = NULL; 582 } 583 close(connfd); 584 } 585 if (family != AF_UNIX) 586 close(s); 587 else if (uflag) { 588 if (connect(s, NULL, 0) < 0) 589 err(1, "connect"); 590 } 591 592 if (!kflag) 593 break; 594 } 595 } else if (family == AF_UNIX) { 596 ret = 0; 597 598 if ((s = unix_connect(host)) > 0 && !zflag) { 599 readwrite(s, NULL); 600 close(s); 601 } else 602 ret = 1; 603 604 if (uflag) 605 unlink(unix_dg_tmp_socket); 606 exit(ret); 607 608 } else { 609 int i = 0; 610 611 /* Construct the portlist[] array. */ 612 build_ports(uport); 613 614 /* Cycle through portlist, connecting to each port. */ 615 for (s = -1, i = 0; portlist[i] != NULL; i++) { 616 if (s != -1) 617 close(s); 618 619 if (usetls) { 620 if ((tls_ctx = tls_client()) == NULL) 621 errx(1, "tls client creation failed"); 622 if (tls_configure(tls_ctx, tls_cfg) == -1) 623 errx(1, "tls configuration failed (%s)", 624 tls_error(tls_ctx)); 625 } 626 if (xflag) 627 s = socks_connect(host, portlist[i], hints, 628 proxyhost, proxyport, proxyhints, socksv, 629 Pflag); 630 else 631 s = remote_connect(host, portlist[i], hints); 632 633 if (s == -1) 634 continue; 635 636 ret = 0; 637 if (vflag || zflag) { 638 /* For UDP, make sure we are connected. */ 639 if (uflag) { 640 if (udptest(s) == -1) { 641 ret = 1; 642 continue; 643 } 644 } 645 646 /* Don't look up port if -n. */ 647 if (nflag) 648 sv = NULL; 649 else { 650 sv = getservbyport( 651 ntohs(atoi(portlist[i])), 652 uflag ? "udp" : "tcp"); 653 } 654 655 fprintf(stderr, 656 "Connection to %s %s port [%s/%s] " 657 "succeeded!\n", host, portlist[i], 658 uflag ? "udp" : "tcp", 659 sv ? sv->s_name : "*"); 660 } 661 if (Fflag) 662 fdpass(s); 663 else { 664 if (usetls) 665 tls_setup_client(tls_ctx, s, host); 666 if (!zflag) 667 readwrite(s, tls_ctx); 668 if (tls_ctx) { 669 int j; 670 671 do { 672 j = tls_close(tls_ctx); 673 } while (j == TLS_WANT_POLLIN || 674 j == TLS_WANT_POLLOUT); 675 tls_free(tls_ctx); 676 tls_ctx = NULL; 677 } 678 } 679 } 680 } 681 682 if (s != -1) 683 close(s); 684 685 tls_config_free(tls_cfg); 686 687 exit(ret); 688 } 689 690 /* 691 * unix_bind() 692 * Returns a unix socket bound to the given path 693 */ 694 int 695 unix_bind(char *path, int flags) 696 { 697 struct sockaddr_un s_un; 698 int s, save_errno; 699 700 /* Create unix domain socket. */ 701 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 702 0)) < 0) 703 return (-1); 704 705 memset(&s_un, 0, sizeof(struct sockaddr_un)); 706 s_un.sun_family = AF_UNIX; 707 708 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 709 sizeof(s_un.sun_path)) { 710 close(s); 711 errno = ENAMETOOLONG; 712 return (-1); 713 } 714 715 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 716 save_errno = errno; 717 close(s); 718 errno = save_errno; 719 return (-1); 720 } 721 return (s); 722 } 723 724 void 725 tls_setup_client(struct tls *tls_ctx, int s, char *host) 726 { 727 int i; 728 729 if (tls_connect_socket(tls_ctx, s, 730 tls_expectname ? tls_expectname : host) == -1) { 731 errx(1, "tls connection failed (%s)", 732 tls_error(tls_ctx)); 733 } 734 do { 735 if ((i = tls_handshake(tls_ctx)) == -1) 736 errx(1, "tls handshake failed (%s)", 737 tls_error(tls_ctx)); 738 } while (i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 739 if (vflag) 740 report_tls(tls_ctx, host, tls_expectname); 741 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 742 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 743 errx(1, "peer certificate is not %s", tls_expecthash); 744 } 745 746 struct tls * 747 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 748 { 749 struct tls *tls_cctx; 750 751 if (tls_accept_socket(tls_ctx, &tls_cctx, 752 connfd) == -1) { 753 warnx("tls accept failed (%s)", 754 tls_error(tls_ctx)); 755 tls_cctx = NULL; 756 } else { 757 int i; 758 759 do { 760 if ((i = tls_handshake(tls_cctx)) == -1) 761 warnx("tls handshake failed (%s)", 762 tls_error(tls_cctx)); 763 } while(i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 764 } 765 if (tls_cctx) { 766 int gotcert = tls_peer_cert_provided(tls_cctx); 767 768 if (vflag && gotcert) 769 report_tls(tls_cctx, host, tls_expectname); 770 if ((TLSopt & TLS_CCERT) && !gotcert) 771 warnx("No client certificate provided"); 772 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 773 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 774 warnx("peer certificate is not %s", tls_expecthash); 775 else if (gotcert && tls_expectname && 776 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 777 warnx("name (%s) not found in client cert", 778 tls_expectname); 779 else { 780 return tls_cctx; 781 } 782 } 783 return NULL; 784 } 785 786 /* 787 * unix_connect() 788 * Returns a socket connected to a local unix socket. Returns -1 on failure. 789 */ 790 int 791 unix_connect(char *path) 792 { 793 struct sockaddr_un s_un; 794 int s, save_errno; 795 796 if (uflag) { 797 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 798 return (-1); 799 } else { 800 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 801 return (-1); 802 } 803 804 memset(&s_un, 0, sizeof(struct sockaddr_un)); 805 s_un.sun_family = AF_UNIX; 806 807 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 808 sizeof(s_un.sun_path)) { 809 close(s); 810 errno = ENAMETOOLONG; 811 return (-1); 812 } 813 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 814 save_errno = errno; 815 close(s); 816 errno = save_errno; 817 return (-1); 818 } 819 return (s); 820 821 } 822 823 /* 824 * unix_listen() 825 * Create a unix domain socket, and listen on it. 826 */ 827 int 828 unix_listen(char *path) 829 { 830 int s; 831 if ((s = unix_bind(path, 0)) < 0) 832 return (-1); 833 834 if (listen(s, 5) < 0) { 835 close(s); 836 return (-1); 837 } 838 return (s); 839 } 840 841 /* 842 * remote_connect() 843 * Returns a socket connected to a remote host. Properly binds to a local 844 * port or source address if needed. Returns -1 on failure. 845 */ 846 int 847 remote_connect(const char *host, const char *port, struct addrinfo hints) 848 { 849 struct addrinfo *res, *res0; 850 int s, error, save_errno; 851 #ifdef SO_BINDANY 852 int on = 1; 853 #endif 854 855 if ((error = getaddrinfo(host, port, &hints, &res))) 856 errx(1, "getaddrinfo: %s", gai_strerror(error)); 857 858 res0 = res; 859 do { 860 if ((s = socket(res0->ai_family, res0->ai_socktype | 861 SOCK_NONBLOCK, res0->ai_protocol)) < 0) 862 continue; 863 864 /* Bind to a local port or source address if specified. */ 865 if (sflag || pflag) { 866 struct addrinfo ahints, *ares; 867 868 #ifdef SO_BINDANY 869 /* try SO_BINDANY, but don't insist */ 870 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 871 #endif 872 memset(&ahints, 0, sizeof(struct addrinfo)); 873 ahints.ai_family = res0->ai_family; 874 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 875 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 876 ahints.ai_flags = AI_PASSIVE; 877 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 878 errx(1, "getaddrinfo: %s", gai_strerror(error)); 879 880 if (bind(s, (struct sockaddr *)ares->ai_addr, 881 ares->ai_addrlen) < 0) 882 err(1, "bind failed"); 883 freeaddrinfo(ares); 884 } 885 886 set_common_sockopts(s, res0->ai_family); 887 888 if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0) 889 break; 890 if (vflag) 891 warn("connect to %s port %s (%s) failed", host, port, 892 uflag ? "udp" : "tcp"); 893 894 save_errno = errno; 895 close(s); 896 errno = save_errno; 897 s = -1; 898 } while ((res0 = res0->ai_next) != NULL); 899 900 freeaddrinfo(res); 901 902 return (s); 903 } 904 905 int 906 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 907 { 908 struct pollfd pfd; 909 socklen_t optlen; 910 int optval; 911 int ret; 912 913 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 914 pfd.fd = s; 915 pfd.events = POLLOUT; 916 if ((ret = poll(&pfd, 1, timeout)) == 1) { 917 optlen = sizeof(optval); 918 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 919 &optval, &optlen)) == 0) { 920 errno = optval; 921 ret = optval == 0 ? 0 : -1; 922 } 923 } else if (ret == 0) { 924 errno = ETIMEDOUT; 925 ret = -1; 926 } else 927 err(1, "poll failed"); 928 } 929 930 return (ret); 931 } 932 933 /* 934 * local_listen() 935 * Returns a socket listening on a local port, binds to specified source 936 * address. Returns -1 on failure. 937 */ 938 int 939 local_listen(char *host, char *port, struct addrinfo hints) 940 { 941 struct addrinfo *res, *res0; 942 int s, save_errno; 943 #ifdef SO_REUSEPORT 944 int ret, x = 1; 945 #endif 946 int error; 947 948 /* Allow nodename to be null. */ 949 hints.ai_flags |= AI_PASSIVE; 950 951 /* 952 * In the case of binding to a wildcard address 953 * default to binding to an ipv4 address. 954 */ 955 if (host == NULL && hints.ai_family == AF_UNSPEC) 956 hints.ai_family = AF_INET; 957 958 if ((error = getaddrinfo(host, port, &hints, &res))) 959 errx(1, "getaddrinfo: %s", gai_strerror(error)); 960 961 res0 = res; 962 do { 963 if ((s = socket(res0->ai_family, res0->ai_socktype, 964 res0->ai_protocol)) < 0) 965 continue; 966 967 #ifdef SO_REUSEPORT 968 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 969 if (ret == -1) 970 err(1, NULL); 971 #endif 972 973 set_common_sockopts(s, res0->ai_family); 974 975 if (bind(s, (struct sockaddr *)res0->ai_addr, 976 res0->ai_addrlen) == 0) 977 break; 978 979 save_errno = errno; 980 close(s); 981 errno = save_errno; 982 s = -1; 983 } while ((res0 = res0->ai_next) != NULL); 984 985 if (!uflag && s != -1) { 986 if (listen(s, 1) < 0) 987 err(1, "listen"); 988 } 989 990 freeaddrinfo(res); 991 992 return (s); 993 } 994 995 /* 996 * readwrite() 997 * Loop that polls on the network file descriptor and stdin. 998 */ 999 void 1000 readwrite(int net_fd, struct tls *tls_ctx) 1001 { 1002 struct pollfd pfd[4]; 1003 int stdin_fd = STDIN_FILENO; 1004 int stdout_fd = STDOUT_FILENO; 1005 unsigned char netinbuf[BUFSIZE]; 1006 size_t netinbufpos = 0; 1007 unsigned char stdinbuf[BUFSIZE]; 1008 size_t stdinbufpos = 0; 1009 int n, num_fds; 1010 ssize_t ret; 1011 1012 /* don't read from stdin if requested */ 1013 if (dflag) 1014 stdin_fd = -1; 1015 1016 /* stdin */ 1017 pfd[POLL_STDIN].fd = stdin_fd; 1018 pfd[POLL_STDIN].events = POLLIN; 1019 1020 /* network out */ 1021 pfd[POLL_NETOUT].fd = net_fd; 1022 pfd[POLL_NETOUT].events = 0; 1023 1024 /* network in */ 1025 pfd[POLL_NETIN].fd = net_fd; 1026 pfd[POLL_NETIN].events = POLLIN; 1027 1028 /* stdout */ 1029 pfd[POLL_STDOUT].fd = stdout_fd; 1030 pfd[POLL_STDOUT].events = 0; 1031 1032 while (1) { 1033 /* both inputs are gone, buffers are empty, we are done */ 1034 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1035 stdinbufpos == 0 && netinbufpos == 0) { 1036 close(net_fd); 1037 return; 1038 } 1039 /* both outputs are gone, we can't continue */ 1040 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 1041 close(net_fd); 1042 return; 1043 } 1044 /* listen and net in gone, queues empty, done */ 1045 if (lflag && pfd[POLL_NETIN].fd == -1 && 1046 stdinbufpos == 0 && netinbufpos == 0) { 1047 close(net_fd); 1048 return; 1049 } 1050 1051 /* help says -i is for "wait between lines sent". We read and 1052 * write arbitrary amounts of data, and we don't want to start 1053 * scanning for newlines, so this is as good as it gets */ 1054 if (iflag) 1055 sleep(iflag); 1056 1057 /* poll */ 1058 num_fds = poll(pfd, 4, timeout); 1059 1060 /* treat poll errors */ 1061 if (num_fds == -1) { 1062 close(net_fd); 1063 err(1, "polling error"); 1064 } 1065 1066 /* timeout happened */ 1067 if (num_fds == 0) 1068 return; 1069 1070 /* treat socket error conditions */ 1071 for (n = 0; n < 4; n++) { 1072 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1073 pfd[n].fd = -1; 1074 } 1075 } 1076 /* reading is possible after HUP */ 1077 if (pfd[POLL_STDIN].events & POLLIN && 1078 pfd[POLL_STDIN].revents & POLLHUP && 1079 !(pfd[POLL_STDIN].revents & POLLIN)) 1080 pfd[POLL_STDIN].fd = -1; 1081 1082 if (pfd[POLL_NETIN].events & POLLIN && 1083 pfd[POLL_NETIN].revents & POLLHUP && 1084 !(pfd[POLL_NETIN].revents & POLLIN)) 1085 pfd[POLL_NETIN].fd = -1; 1086 1087 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1088 if (Nflag) 1089 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1090 pfd[POLL_NETOUT].fd = -1; 1091 } 1092 /* if HUP, stop watching stdout */ 1093 if (pfd[POLL_STDOUT].revents & POLLHUP) 1094 pfd[POLL_STDOUT].fd = -1; 1095 /* if no net out, stop watching stdin */ 1096 if (pfd[POLL_NETOUT].fd == -1) 1097 pfd[POLL_STDIN].fd = -1; 1098 /* if no stdout, stop watching net in */ 1099 if (pfd[POLL_STDOUT].fd == -1) { 1100 if (pfd[POLL_NETIN].fd != -1) 1101 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1102 pfd[POLL_NETIN].fd = -1; 1103 } 1104 1105 /* try to read from stdin */ 1106 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1107 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1108 &stdinbufpos, NULL); 1109 if (ret == TLS_WANT_POLLIN) 1110 pfd[POLL_STDIN].events = POLLIN; 1111 else if (ret == TLS_WANT_POLLOUT) 1112 pfd[POLL_STDIN].events = POLLOUT; 1113 else if (ret == 0 || ret == -1) 1114 pfd[POLL_STDIN].fd = -1; 1115 /* read something - poll net out */ 1116 if (stdinbufpos > 0) 1117 pfd[POLL_NETOUT].events = POLLOUT; 1118 /* filled buffer - remove self from polling */ 1119 if (stdinbufpos == BUFSIZE) 1120 pfd[POLL_STDIN].events = 0; 1121 } 1122 /* try to write to network */ 1123 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1124 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1125 &stdinbufpos, tls_ctx); 1126 if (ret == TLS_WANT_POLLIN) 1127 pfd[POLL_NETOUT].events = POLLIN; 1128 else if (ret == TLS_WANT_POLLOUT) 1129 pfd[POLL_NETOUT].events = POLLOUT; 1130 else if (ret == -1) 1131 pfd[POLL_NETOUT].fd = -1; 1132 /* buffer empty - remove self from polling */ 1133 if (stdinbufpos == 0) 1134 pfd[POLL_NETOUT].events = 0; 1135 /* buffer no longer full - poll stdin again */ 1136 if (stdinbufpos < BUFSIZE) 1137 pfd[POLL_STDIN].events = POLLIN; 1138 } 1139 /* try to read from network */ 1140 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1141 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1142 &netinbufpos, tls_ctx); 1143 if (ret == TLS_WANT_POLLIN) 1144 pfd[POLL_NETIN].events = POLLIN; 1145 else if (ret == TLS_WANT_POLLOUT) 1146 pfd[POLL_NETIN].events = POLLOUT; 1147 else if (ret == -1) 1148 pfd[POLL_NETIN].fd = -1; 1149 /* eof on net in - remove from pfd */ 1150 if (ret == 0) { 1151 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1152 pfd[POLL_NETIN].fd = -1; 1153 } 1154 /* read something - poll stdout */ 1155 if (netinbufpos > 0) 1156 pfd[POLL_STDOUT].events = POLLOUT; 1157 /* filled buffer - remove self from polling */ 1158 if (netinbufpos == BUFSIZE) 1159 pfd[POLL_NETIN].events = 0; 1160 /* handle telnet */ 1161 if (tflag) 1162 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1163 netinbufpos); 1164 } 1165 /* try to write to stdout */ 1166 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1167 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1168 &netinbufpos, NULL); 1169 if (ret == TLS_WANT_POLLIN) 1170 pfd[POLL_STDOUT].events = POLLIN; 1171 else if (ret == TLS_WANT_POLLOUT) 1172 pfd[POLL_STDOUT].events = POLLOUT; 1173 else if (ret == -1) 1174 pfd[POLL_STDOUT].fd = -1; 1175 /* buffer empty - remove self from polling */ 1176 if (netinbufpos == 0) 1177 pfd[POLL_STDOUT].events = 0; 1178 /* buffer no longer full - poll net in again */ 1179 if (netinbufpos < BUFSIZE) 1180 pfd[POLL_NETIN].events = POLLIN; 1181 } 1182 1183 /* stdin gone and queue empty? */ 1184 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1185 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1186 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1187 pfd[POLL_NETOUT].fd = -1; 1188 } 1189 /* net in gone and queue empty? */ 1190 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1191 pfd[POLL_STDOUT].fd = -1; 1192 } 1193 } 1194 } 1195 1196 ssize_t 1197 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1198 { 1199 ssize_t n; 1200 ssize_t adjust; 1201 1202 if (tls) 1203 n = tls_write(tls, buf, *bufpos); 1204 else { 1205 n = write(fd, buf, *bufpos); 1206 /* don't treat EAGAIN, EINTR as error */ 1207 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1208 n = TLS_WANT_POLLOUT; 1209 } 1210 if (n <= 0) 1211 return n; 1212 /* adjust buffer */ 1213 adjust = *bufpos - n; 1214 if (adjust > 0) 1215 memmove(buf, buf + n, adjust); 1216 *bufpos -= n; 1217 return n; 1218 } 1219 1220 ssize_t 1221 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1222 { 1223 size_t num = BUFSIZE - *bufpos; 1224 ssize_t n; 1225 1226 if (tls) 1227 n = tls_read(tls, buf + *bufpos, num); 1228 else { 1229 n = read(fd, buf + *bufpos, num); 1230 /* don't treat EAGAIN, EINTR as error */ 1231 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1232 n = TLS_WANT_POLLIN; 1233 } 1234 if (n <= 0) 1235 return n; 1236 *bufpos += n; 1237 return n; 1238 } 1239 1240 /* 1241 * fdpass() 1242 * Pass the connected file descriptor to stdout and exit. 1243 */ 1244 void 1245 fdpass(int nfd) 1246 { 1247 struct msghdr mh; 1248 union { 1249 struct cmsghdr hdr; 1250 char buf[CMSG_SPACE(sizeof(int))]; 1251 } cmsgbuf; 1252 struct cmsghdr *cmsg; 1253 struct iovec iov; 1254 char c = '\0'; 1255 ssize_t r; 1256 struct pollfd pfd; 1257 1258 /* Avoid obvious stupidity */ 1259 if (isatty(STDOUT_FILENO)) 1260 errx(1, "Cannot pass file descriptor to tty"); 1261 1262 bzero(&mh, sizeof(mh)); 1263 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1264 bzero(&iov, sizeof(iov)); 1265 1266 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1267 mh.msg_controllen = sizeof(cmsgbuf.buf); 1268 cmsg = CMSG_FIRSTHDR(&mh); 1269 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1270 cmsg->cmsg_level = SOL_SOCKET; 1271 cmsg->cmsg_type = SCM_RIGHTS; 1272 *(int *)CMSG_DATA(cmsg) = nfd; 1273 1274 iov.iov_base = &c; 1275 iov.iov_len = 1; 1276 mh.msg_iov = &iov; 1277 mh.msg_iovlen = 1; 1278 1279 bzero(&pfd, sizeof(pfd)); 1280 pfd.fd = STDOUT_FILENO; 1281 pfd.events = POLLOUT; 1282 for (;;) { 1283 r = sendmsg(STDOUT_FILENO, &mh, 0); 1284 if (r == -1) { 1285 if (errno == EAGAIN || errno == EINTR) { 1286 if (poll(&pfd, 1, -1) == -1) 1287 err(1, "poll"); 1288 continue; 1289 } 1290 err(1, "sendmsg"); 1291 } else if (r != 1) 1292 errx(1, "sendmsg: unexpected return value %zd", r); 1293 else 1294 break; 1295 } 1296 exit(0); 1297 } 1298 1299 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1300 void 1301 atelnet(int nfd, unsigned char *buf, unsigned int size) 1302 { 1303 unsigned char *p, *end; 1304 unsigned char obuf[4]; 1305 1306 if (size < 3) 1307 return; 1308 end = buf + size - 2; 1309 1310 for (p = buf; p < end; p++) { 1311 if (*p != IAC) 1312 continue; 1313 1314 obuf[0] = IAC; 1315 p++; 1316 if ((*p == WILL) || (*p == WONT)) 1317 obuf[1] = DONT; 1318 else if ((*p == DO) || (*p == DONT)) 1319 obuf[1] = WONT; 1320 else 1321 continue; 1322 1323 p++; 1324 obuf[2] = *p; 1325 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1326 warn("Write Error!"); 1327 } 1328 } 1329 1330 1331 int 1332 strtoport(char *portstr, int udp) 1333 { 1334 struct servent *entry; 1335 const char *errstr; 1336 char *proto; 1337 int port = -1; 1338 1339 proto = udp ? "udp" : "tcp"; 1340 1341 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1342 if (errstr == NULL) 1343 return port; 1344 if (errno != EINVAL) 1345 errx(1, "port number %s: %s", errstr, portstr); 1346 if ((entry = getservbyname(portstr, proto)) == NULL) 1347 errx(1, "service \"%s\" unknown", portstr); 1348 return ntohs(entry->s_port); 1349 } 1350 1351 /* 1352 * build_ports() 1353 * Build an array of ports in portlist[], listing each port 1354 * that we should try to connect to. 1355 */ 1356 void 1357 build_ports(char *p) 1358 { 1359 char *n; 1360 int hi, lo, cp; 1361 int x = 0; 1362 1363 if ((n = strchr(p, '-')) != NULL) { 1364 *n = '\0'; 1365 n++; 1366 1367 /* Make sure the ports are in order: lowest->highest. */ 1368 hi = strtoport(n, uflag); 1369 lo = strtoport(p, uflag); 1370 if (lo > hi) { 1371 cp = hi; 1372 hi = lo; 1373 lo = cp; 1374 } 1375 1376 /* 1377 * Initialize portlist with a random permutation. Based on 1378 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1379 */ 1380 if (rflag) { 1381 for (x = 0; x <= hi - lo; x++) { 1382 cp = arc4random_uniform(x + 1); 1383 portlist[x] = portlist[cp]; 1384 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1385 err(1, "asprintf"); 1386 } 1387 } else { /* Load ports sequentially. */ 1388 for (cp = lo; cp <= hi; cp++) { 1389 if (asprintf(&portlist[x], "%d", cp) < 0) 1390 err(1, "asprintf"); 1391 x++; 1392 } 1393 } 1394 } else { 1395 char *tmp; 1396 1397 hi = strtoport(p, uflag); 1398 if (asprintf(&tmp, "%d", hi) != -1) 1399 portlist[0] = tmp; 1400 else 1401 err(1, NULL); 1402 } 1403 } 1404 1405 /* 1406 * udptest() 1407 * Do a few writes to see if the UDP port is there. 1408 * Fails once PF state table is full. 1409 */ 1410 int 1411 udptest(int s) 1412 { 1413 int i, ret; 1414 1415 for (i = 0; i <= 3; i++) { 1416 if (write(s, "X", 1) == 1) 1417 ret = 1; 1418 else 1419 ret = -1; 1420 } 1421 return (ret); 1422 } 1423 1424 void 1425 set_common_sockopts(int s, int af) 1426 { 1427 int x = 1; 1428 1429 #ifdef TCP_MD5SIG 1430 if (Sflag) { 1431 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1432 &x, sizeof(x)) == -1) 1433 err(1, NULL); 1434 } 1435 #endif 1436 if (Dflag) { 1437 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1438 &x, sizeof(x)) == -1) 1439 err(1, NULL); 1440 } 1441 if (Tflag != -1) { 1442 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1443 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1444 err(1, "set IP ToS"); 1445 1446 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1447 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1448 err(1, "set IPv6 traffic class"); 1449 } 1450 if (Iflag) { 1451 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1452 &Iflag, sizeof(Iflag)) == -1) 1453 err(1, "set TCP receive buffer size"); 1454 } 1455 if (Oflag) { 1456 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1457 &Oflag, sizeof(Oflag)) == -1) 1458 err(1, "set TCP send buffer size"); 1459 } 1460 1461 if (ttl != -1) { 1462 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1463 IP_TTL, &ttl, sizeof(ttl))) 1464 err(1, "set IP TTL"); 1465 1466 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1467 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1468 err(1, "set IPv6 unicast hops"); 1469 } 1470 1471 if (minttl != -1) { 1472 #ifdef IP_MINTTL 1473 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1474 IP_MINTTL, &minttl, sizeof(minttl))) 1475 err(1, "set IP min TTL"); 1476 #endif 1477 1478 #ifdef IPV6_MINHOPCOUNT 1479 if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1480 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1481 err(1, "set IPv6 min hop count"); 1482 #endif 1483 } 1484 } 1485 1486 int 1487 map_tos(char *s, int *val) 1488 { 1489 /* DiffServ Codepoints and other TOS mappings */ 1490 const struct toskeywords { 1491 const char *keyword; 1492 int val; 1493 } *t, toskeywords[] = { 1494 { "af11", IPTOS_DSCP_AF11 }, 1495 { "af12", IPTOS_DSCP_AF12 }, 1496 { "af13", IPTOS_DSCP_AF13 }, 1497 { "af21", IPTOS_DSCP_AF21 }, 1498 { "af22", IPTOS_DSCP_AF22 }, 1499 { "af23", IPTOS_DSCP_AF23 }, 1500 { "af31", IPTOS_DSCP_AF31 }, 1501 { "af32", IPTOS_DSCP_AF32 }, 1502 { "af33", IPTOS_DSCP_AF33 }, 1503 { "af41", IPTOS_DSCP_AF41 }, 1504 { "af42", IPTOS_DSCP_AF42 }, 1505 { "af43", IPTOS_DSCP_AF43 }, 1506 { "critical", IPTOS_PREC_CRITIC_ECP }, 1507 { "cs0", IPTOS_DSCP_CS0 }, 1508 { "cs1", IPTOS_DSCP_CS1 }, 1509 { "cs2", IPTOS_DSCP_CS2 }, 1510 { "cs3", IPTOS_DSCP_CS3 }, 1511 { "cs4", IPTOS_DSCP_CS4 }, 1512 { "cs5", IPTOS_DSCP_CS5 }, 1513 { "cs6", IPTOS_DSCP_CS6 }, 1514 { "cs7", IPTOS_DSCP_CS7 }, 1515 { "ef", IPTOS_DSCP_EF }, 1516 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1517 { "lowdelay", IPTOS_LOWDELAY }, 1518 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1519 { "reliability", IPTOS_RELIABILITY }, 1520 { "throughput", IPTOS_THROUGHPUT }, 1521 { NULL, -1 }, 1522 }; 1523 1524 for (t = toskeywords; t->keyword != NULL; t++) { 1525 if (strcmp(s, t->keyword) == 0) { 1526 *val = t->val; 1527 return (1); 1528 } 1529 } 1530 1531 return (0); 1532 } 1533 1534 int 1535 map_tls(char *s, int *val) 1536 { 1537 const struct tlskeywords { 1538 const char *keyword; 1539 int val; 1540 } *t, tlskeywords[] = { 1541 { "tlslegacy", TLS_LEGACY }, 1542 { "noverify", TLS_NOVERIFY }, 1543 { "noname", TLS_NONAME }, 1544 { "clientcert", TLS_CCERT}, 1545 { NULL, -1 }, 1546 }; 1547 1548 for (t = tlskeywords; t->keyword != NULL; t++) { 1549 if (strcmp(s, t->keyword) == 0) { 1550 *val |= t->val; 1551 return (1); 1552 } 1553 } 1554 return (0); 1555 } 1556 1557 void 1558 report_tls(struct tls * tls_ctx, char * host, char *tls_expectname) 1559 { 1560 time_t t; 1561 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1562 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1563 fprintf(stderr, "Peer name: %s\n", 1564 tls_expectname ? tls_expectname : host); 1565 if (tls_peer_cert_subject(tls_ctx)) 1566 fprintf(stderr, "Subject: %s\n", 1567 tls_peer_cert_subject(tls_ctx)); 1568 if (tls_peer_cert_issuer(tls_ctx)) 1569 fprintf(stderr, "Issuer: %s\n", 1570 tls_peer_cert_issuer(tls_ctx)); 1571 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1572 fprintf(stderr, "Valid From: %s", ctime(&t)); 1573 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1574 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1575 if (tls_peer_cert_hash(tls_ctx)) 1576 fprintf(stderr, "Cert Hash: %s\n", 1577 tls_peer_cert_hash(tls_ctx)); 1578 } 1579 1580 void 1581 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1582 { 1583 char remote_host[NI_MAXHOST]; 1584 char remote_port[NI_MAXSERV]; 1585 int herr; 1586 int flags = NI_NUMERICSERV; 1587 1588 if (path != NULL) { 1589 fprintf(stderr, "Connection on %s received!\n", path); 1590 return; 1591 } 1592 1593 if (nflag) 1594 flags |= NI_NUMERICHOST; 1595 1596 if ((herr = getnameinfo(sa, salen, 1597 remote_host, sizeof(remote_host), 1598 remote_port, sizeof(remote_port), 1599 flags)) != 0) { 1600 if (herr == EAI_SYSTEM) 1601 err(1, "getnameinfo"); 1602 else 1603 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1604 } 1605 1606 fprintf(stderr, 1607 "Connection from %s %s " 1608 "received!\n", remote_host, remote_port); 1609 } 1610 1611 void 1612 help(void) 1613 { 1614 usage(0); 1615 fprintf(stderr, "\tCommand Summary:\n\ 1616 \t-4 Use IPv4\n\ 1617 \t-6 Use IPv6\n\ 1618 \t-C certfile Public key file\n\ 1619 \t-c Use TLS\n\ 1620 \t-D Enable the debug socket option\n\ 1621 \t-d Detach from stdin\n\ 1622 \t-e name\t Required name in peer certificate\n\ 1623 \t-F Pass socket fd\n\ 1624 \t-H hash\t Hash string of peer certificate\n\ 1625 \t-h This help text\n\ 1626 \t-I length TCP receive buffer length\n\ 1627 \t-i interval Delay interval for lines sent, ports scanned\n\ 1628 \t-K keyfile Private key file\n\ 1629 \t-k Keep inbound sockets open for multiple connects\n\ 1630 \t-l Listen mode, for inbound connects\n\ 1631 \t-M ttl Outgoing TTL / Hop Limit\n\ 1632 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1633 \t-N Shutdown the network socket after EOF on stdin\n\ 1634 \t-n Suppress name/port resolutions\n\ 1635 \t-O length TCP send buffer length\n\ 1636 \t-P proxyuser\tUsername for proxy authentication\n\ 1637 \t-p port\t Specify local port for remote connects\n\ 1638 \t-R CAfile CA bundle\n\ 1639 \t-r Randomize remote ports\n" 1640 #ifdef TCP_MD5SIG 1641 "\ 1642 \t-S Enable the TCP MD5 signature option\n" 1643 #endif 1644 "\ 1645 \t-s source Local source address\n\ 1646 \t-T keyword TOS value or TLS options\n\ 1647 \t-t Answer TELNET negotiation\n\ 1648 \t-U Use UNIX domain socket\n\ 1649 \t-u UDP mode\n" 1650 #ifdef SO_RTABLE 1651 "\ 1652 \t-V rtable Specify alternate routing table\n" 1653 #endif 1654 "\ 1655 \t-v Verbose\n\ 1656 \t-w timeout Timeout for connects and final net reads\n\ 1657 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1658 \t-x addr[:port]\tSpecify proxy address and port\n\ 1659 \t-z Zero-I/O mode [used for scanning]\n\ 1660 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1661 exit(1); 1662 } 1663 1664 void 1665 usage(int ret) 1666 { 1667 fprintf(stderr, 1668 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1669 "[-H hash] [-I length]\n" 1670 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1671 "\t [-P proxy_username] [-p source_port] [-R CAfile] [-s source]\n" 1672 "\t [-T keyword] [-V rtable] [-w timeout] [-X proxy_protocol]\n" 1673 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1674 if (ret) 1675 exit(1); 1676 } 1677