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 #ifdef __OpenBSD__ 346 if (family == AF_UNIX) { 347 if (pledge("stdio rpath wpath cpath tmppath unix", NULL) == -1) 348 err(1, "pledge"); 349 } else if (Fflag) { 350 if (Pflag) { 351 if (pledge("stdio inet dns sendfd tty", NULL) == -1) 352 err(1, "pledge"); 353 } else if (pledge("stdio inet dns sendfd", NULL) == -1) 354 err(1, "pledge"); 355 } else if (Pflag) { 356 if (pledge("stdio inet dns tty", NULL) == -1) 357 err(1, "pledge"); 358 } else if (usetls) { 359 if (pledge("stdio rpath inet dns", NULL) == -1) 360 err(1, "pledge"); 361 } else if (pledge("stdio inet dns", NULL) == -1) 362 err(1, "pledge"); 363 #endif 364 365 /* Cruft to make sure options are clean, and used properly. */ 366 if (argv[0] && !argv[1] && family == AF_UNIX) { 367 host = argv[0]; 368 uport = NULL; 369 } else if (argv[0] && !argv[1]) { 370 if (!lflag) 371 usage(1); 372 uport = argv[0]; 373 host = NULL; 374 } else if (argv[0] && argv[1]) { 375 host = argv[0]; 376 uport = argv[1]; 377 } else 378 usage(1); 379 380 if (lflag && sflag) 381 errx(1, "cannot use -s and -l"); 382 if (lflag && pflag) 383 errx(1, "cannot use -p and -l"); 384 if (lflag && zflag) 385 errx(1, "cannot use -z and -l"); 386 if (!lflag && kflag) 387 errx(1, "must use -l with -k"); 388 if (uflag && usetls) 389 errx(1, "cannot use -c and -u"); 390 if ((family == AF_UNIX) && usetls) 391 errx(1, "cannot use -c and -U"); 392 if ((family == AF_UNIX) && Fflag) 393 errx(1, "cannot use -F and -U"); 394 if (Fflag && usetls) 395 errx(1, "cannot use -c and -F"); 396 if (TLSopt && !usetls) 397 errx(1, "you must specify -c to use TLS options"); 398 if (Cflag && !usetls) 399 errx(1, "you must specify -c to use -C"); 400 if (Kflag && !usetls) 401 errx(1, "you must specify -c to use -K"); 402 if (tls_cachanged && !usetls) 403 errx(1, "you must specify -c to use -R"); 404 if (tls_expecthash && !usetls) 405 errx(1, "you must specify -c to use -H"); 406 if (tls_expectname && !usetls) 407 errx(1, "you must specify -c to use -e"); 408 409 /* Get name of temporary socket for unix datagram client */ 410 if ((family == AF_UNIX) && uflag && !lflag) { 411 if (sflag) { 412 unix_dg_tmp_socket = sflag; 413 } else { 414 strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX", 415 UNIX_DG_TMP_SOCKET_SIZE); 416 if (mktemp(unix_dg_tmp_socket_buf) == NULL) 417 err(1, "mktemp"); 418 unix_dg_tmp_socket = unix_dg_tmp_socket_buf; 419 } 420 } 421 422 /* Initialize addrinfo structure. */ 423 if (family != AF_UNIX) { 424 memset(&hints, 0, sizeof(struct addrinfo)); 425 hints.ai_family = family; 426 hints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 427 hints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 428 if (nflag) 429 hints.ai_flags |= AI_NUMERICHOST; 430 } 431 432 if (xflag) { 433 if (uflag) 434 errx(1, "no proxy support for UDP mode"); 435 436 if (lflag) 437 errx(1, "no proxy support for listen"); 438 439 if (family == AF_UNIX) 440 errx(1, "no proxy support for unix sockets"); 441 442 /* XXX IPv6 transport to proxy would probably work */ 443 if (family == AF_INET6) 444 errx(1, "no proxy support for IPv6"); 445 446 if (sflag) 447 errx(1, "no proxy support for local source address"); 448 449 proxyhost = strsep(&proxy, ":"); 450 proxyport = proxy; 451 452 memset(&proxyhints, 0, sizeof(struct addrinfo)); 453 proxyhints.ai_family = family; 454 proxyhints.ai_socktype = SOCK_STREAM; 455 proxyhints.ai_protocol = IPPROTO_TCP; 456 if (nflag) 457 proxyhints.ai_flags |= AI_NUMERICHOST; 458 } 459 460 if (usetls) { 461 if (Rflag && (cacert = tls_load_file(Rflag, &cacertlen, NULL)) == NULL) 462 errx(1, "unable to load root CA file %s", Rflag); 463 if (Cflag && (pubcert = tls_load_file(Cflag, &pubcertlen, NULL)) == NULL) 464 errx(1, "unable to load TLS certificate file %s", Cflag); 465 if (Kflag && (privkey = tls_load_file(Kflag, &privkeylen, NULL)) == NULL) 466 errx(1, "unable to load TLS key file %s", Kflag); 467 468 #ifdef __OpenBSD__ 469 if (Pflag) { 470 if (pledge("stdio inet dns tty", NULL) == -1) 471 err(1, "pledge"); 472 } else if (pledge("stdio inet dns", NULL) == -1) 473 err(1, "pledge"); 474 #endif 475 476 if (tls_init() == -1) 477 errx(1, "unable to initialize TLS"); 478 if ((tls_cfg = tls_config_new()) == NULL) 479 errx(1, "unable to allocate TLS config"); 480 if (Rflag && tls_config_set_ca_mem(tls_cfg, cacert, cacertlen) == -1) 481 errx(1, "unable to set root CA file %s", Rflag); 482 if (Cflag && tls_config_set_cert_mem(tls_cfg, pubcert, pubcertlen) == -1) 483 errx(1, "unable to set TLS certificate file %s", Cflag); 484 if (Kflag && tls_config_set_key_mem(tls_cfg, privkey, privkeylen) == -1) 485 errx(1, "unable to set TLS key file %s", Kflag); 486 if (TLSopt & TLS_LEGACY) { 487 tls_config_set_protocols(tls_cfg, TLS_PROTOCOLS_ALL); 488 tls_config_set_ciphers(tls_cfg, "all"); 489 } 490 if (!lflag && (TLSopt & TLS_CCERT)) 491 errx(1, "clientcert is only valid with -l"); 492 if (TLSopt & TLS_NONAME) 493 tls_config_insecure_noverifyname(tls_cfg); 494 if (TLSopt & TLS_NOVERIFY) { 495 if (tls_expecthash != NULL) 496 errx(1, "-H and -T noverify may not be used" 497 "together"); 498 tls_config_insecure_noverifycert(tls_cfg); 499 } else { 500 if (Rflag && access(Rflag, R_OK) == -1) 501 errx(1, "unable to find root CA file %s", Rflag); 502 } 503 } 504 if (lflag) { 505 struct tls *tls_cctx = NULL; 506 int connfd; 507 ret = 0; 508 509 if (family == AF_UNIX) { 510 if (uflag) 511 s = unix_bind(host, 0); 512 else 513 s = unix_listen(host); 514 } 515 516 if (usetls) { 517 tls_config_verify_client_optional(tls_cfg); 518 if ((tls_ctx = tls_server()) == NULL) 519 errx(1, "tls server creation failed"); 520 if (tls_configure(tls_ctx, tls_cfg) == -1) 521 errx(1, "tls configuration failed (%s)", 522 tls_error(tls_ctx)); 523 } 524 /* Allow only one connection at a time, but stay alive. */ 525 for (;;) { 526 if (family != AF_UNIX) 527 s = local_listen(host, uport, hints); 528 if (s < 0) 529 err(1, NULL); 530 /* 531 * For UDP and -k, don't connect the socket, let it 532 * receive datagrams from multiple socket pairs. 533 */ 534 if (uflag && kflag) 535 readwrite(s, NULL); 536 /* 537 * For UDP and not -k, we will use recvfrom() initially 538 * to wait for a caller, then use the regular functions 539 * to talk to the caller. 540 */ 541 else if (uflag && !kflag) { 542 int rv, plen; 543 char buf[16384]; 544 struct sockaddr_storage z; 545 546 len = sizeof(z); 547 plen = 2048; 548 rv = recvfrom(s, buf, plen, MSG_PEEK, 549 (struct sockaddr *)&z, &len); 550 if (rv < 0) 551 err(1, "recvfrom"); 552 553 rv = connect(s, (struct sockaddr *)&z, len); 554 if (rv < 0) 555 err(1, "connect"); 556 557 if (vflag) 558 report_connect((struct sockaddr *)&z, len, NULL); 559 560 readwrite(s, NULL); 561 } else { 562 len = sizeof(cliaddr); 563 connfd = accept4(s, (struct sockaddr *)&cliaddr, 564 &len, SOCK_NONBLOCK); 565 if (connfd == -1) { 566 /* For now, all errnos are fatal */ 567 err(1, "accept"); 568 } 569 if (vflag) 570 report_connect((struct sockaddr *)&cliaddr, len, 571 family == AF_UNIX ? host : NULL); 572 if ((usetls) && 573 (tls_cctx = tls_setup_server(tls_ctx, connfd, host))) 574 readwrite(connfd, tls_cctx); 575 if (!usetls) 576 readwrite(connfd, NULL); 577 if (tls_cctx) { 578 int i; 579 580 do { 581 i = tls_close(tls_cctx); 582 } while (i == TLS_WANT_POLLIN || 583 i == TLS_WANT_POLLOUT); 584 tls_free(tls_cctx); 585 tls_cctx = NULL; 586 } 587 close(connfd); 588 } 589 if (family != AF_UNIX) 590 close(s); 591 else if (uflag) { 592 if (connect(s, NULL, 0) < 0) 593 err(1, "connect"); 594 } 595 596 if (!kflag) 597 break; 598 } 599 } else if (family == AF_UNIX) { 600 ret = 0; 601 602 if ((s = unix_connect(host)) > 0 && !zflag) { 603 readwrite(s, NULL); 604 close(s); 605 } else 606 ret = 1; 607 608 if (uflag) 609 unlink(unix_dg_tmp_socket); 610 exit(ret); 611 612 } else { 613 int i = 0; 614 615 /* Construct the portlist[] array. */ 616 build_ports(uport); 617 618 /* Cycle through portlist, connecting to each port. */ 619 for (s = -1, i = 0; portlist[i] != NULL; i++) { 620 if (s != -1) 621 close(s); 622 623 if (usetls) { 624 if ((tls_ctx = tls_client()) == NULL) 625 errx(1, "tls client creation failed"); 626 if (tls_configure(tls_ctx, tls_cfg) == -1) 627 errx(1, "tls configuration failed (%s)", 628 tls_error(tls_ctx)); 629 } 630 if (xflag) 631 s = socks_connect(host, portlist[i], hints, 632 proxyhost, proxyport, proxyhints, socksv, 633 Pflag); 634 else 635 s = remote_connect(host, portlist[i], hints); 636 637 if (s == -1) 638 continue; 639 640 ret = 0; 641 if (vflag || zflag) { 642 /* For UDP, make sure we are connected. */ 643 if (uflag) { 644 if (udptest(s) == -1) { 645 ret = 1; 646 continue; 647 } 648 } 649 650 /* Don't look up port if -n. */ 651 if (nflag) 652 sv = NULL; 653 else { 654 sv = getservbyport( 655 ntohs(atoi(portlist[i])), 656 uflag ? "udp" : "tcp"); 657 } 658 659 fprintf(stderr, 660 "Connection to %s %s port [%s/%s] " 661 "succeeded!\n", host, portlist[i], 662 uflag ? "udp" : "tcp", 663 sv ? sv->s_name : "*"); 664 } 665 if (Fflag) 666 fdpass(s); 667 else { 668 if (usetls) 669 tls_setup_client(tls_ctx, s, host); 670 if (!zflag) 671 readwrite(s, tls_ctx); 672 if (tls_ctx) { 673 int j; 674 675 do { 676 j = tls_close(tls_ctx); 677 } while (j == TLS_WANT_POLLIN || 678 j == TLS_WANT_POLLOUT); 679 tls_free(tls_ctx); 680 tls_ctx = NULL; 681 } 682 } 683 } 684 } 685 686 if (s != -1) 687 close(s); 688 689 tls_config_free(tls_cfg); 690 691 exit(ret); 692 } 693 694 /* 695 * unix_bind() 696 * Returns a unix socket bound to the given path 697 */ 698 int 699 unix_bind(char *path, int flags) 700 { 701 struct sockaddr_un s_un; 702 int s, save_errno; 703 704 /* Create unix domain socket. */ 705 if ((s = socket(AF_UNIX, flags | (uflag ? SOCK_DGRAM : SOCK_STREAM), 706 0)) < 0) 707 return (-1); 708 709 memset(&s_un, 0, sizeof(struct sockaddr_un)); 710 s_un.sun_family = AF_UNIX; 711 712 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 713 sizeof(s_un.sun_path)) { 714 close(s); 715 errno = ENAMETOOLONG; 716 return (-1); 717 } 718 719 if (bind(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 720 save_errno = errno; 721 close(s); 722 errno = save_errno; 723 return (-1); 724 } 725 return (s); 726 } 727 728 void 729 tls_setup_client(struct tls *tls_ctx, int s, char *host) 730 { 731 int i; 732 733 if (tls_connect_socket(tls_ctx, s, 734 tls_expectname ? tls_expectname : host) == -1) { 735 errx(1, "tls connection failed (%s)", 736 tls_error(tls_ctx)); 737 } 738 do { 739 if ((i = tls_handshake(tls_ctx)) == -1) 740 errx(1, "tls handshake failed (%s)", 741 tls_error(tls_ctx)); 742 } while (i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 743 if (vflag) 744 report_tls(tls_ctx, host, tls_expectname); 745 if (tls_expecthash && tls_peer_cert_hash(tls_ctx) && 746 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 747 errx(1, "peer certificate is not %s", tls_expecthash); 748 } 749 750 struct tls * 751 tls_setup_server(struct tls *tls_ctx, int connfd, char *host) 752 { 753 struct tls *tls_cctx; 754 755 if (tls_accept_socket(tls_ctx, &tls_cctx, 756 connfd) == -1) { 757 warnx("tls accept failed (%s)", 758 tls_error(tls_ctx)); 759 tls_cctx = NULL; 760 } else { 761 int i; 762 763 do { 764 if ((i = tls_handshake(tls_cctx)) == -1) 765 warnx("tls handshake failed (%s)", 766 tls_error(tls_cctx)); 767 } while(i == TLS_WANT_POLLIN || i == TLS_WANT_POLLOUT); 768 } 769 if (tls_cctx) { 770 int gotcert = tls_peer_cert_provided(tls_cctx); 771 772 if (vflag && gotcert) 773 report_tls(tls_cctx, host, tls_expectname); 774 if ((TLSopt & TLS_CCERT) && !gotcert) 775 warnx("No client certificate provided"); 776 else if (gotcert && tls_peer_cert_hash(tls_ctx) && tls_expecthash && 777 strcmp(tls_expecthash, tls_peer_cert_hash(tls_ctx)) != 0) 778 warnx("peer certificate is not %s", tls_expecthash); 779 else if (gotcert && tls_expectname && 780 (!tls_peer_cert_contains_name(tls_cctx, tls_expectname))) 781 warnx("name (%s) not found in client cert", 782 tls_expectname); 783 else { 784 return tls_cctx; 785 } 786 } 787 return NULL; 788 } 789 790 /* 791 * unix_connect() 792 * Returns a socket connected to a local unix socket. Returns -1 on failure. 793 */ 794 int 795 unix_connect(char *path) 796 { 797 struct sockaddr_un s_un; 798 int s, save_errno; 799 800 if (uflag) { 801 if ((s = unix_bind(unix_dg_tmp_socket, SOCK_CLOEXEC)) < 0) 802 return (-1); 803 } else { 804 if ((s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0)) < 0) 805 return (-1); 806 } 807 808 memset(&s_un, 0, sizeof(struct sockaddr_un)); 809 s_un.sun_family = AF_UNIX; 810 811 if (strlcpy(s_un.sun_path, path, sizeof(s_un.sun_path)) >= 812 sizeof(s_un.sun_path)) { 813 close(s); 814 errno = ENAMETOOLONG; 815 return (-1); 816 } 817 if (connect(s, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { 818 save_errno = errno; 819 close(s); 820 errno = save_errno; 821 return (-1); 822 } 823 return (s); 824 825 } 826 827 /* 828 * unix_listen() 829 * Create a unix domain socket, and listen on it. 830 */ 831 int 832 unix_listen(char *path) 833 { 834 int s; 835 if ((s = unix_bind(path, 0)) < 0) 836 return (-1); 837 838 if (listen(s, 5) < 0) { 839 close(s); 840 return (-1); 841 } 842 return (s); 843 } 844 845 /* 846 * remote_connect() 847 * Returns a socket connected to a remote host. Properly binds to a local 848 * port or source address if needed. Returns -1 on failure. 849 */ 850 int 851 remote_connect(const char *host, const char *port, struct addrinfo hints) 852 { 853 struct addrinfo *res, *res0; 854 int s, error, save_errno; 855 #ifdef SO_BINDANY 856 int on = 1; 857 #endif 858 859 if ((error = getaddrinfo(host, port, &hints, &res))) 860 errx(1, "getaddrinfo: %s", gai_strerror(error)); 861 862 res0 = res; 863 do { 864 if ((s = socket(res0->ai_family, res0->ai_socktype | 865 SOCK_NONBLOCK, res0->ai_protocol)) < 0) 866 continue; 867 868 /* Bind to a local port or source address if specified. */ 869 if (sflag || pflag) { 870 struct addrinfo ahints, *ares; 871 872 #ifdef SO_BINDANY 873 /* try SO_BINDANY, but don't insist */ 874 setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on)); 875 #endif 876 memset(&ahints, 0, sizeof(struct addrinfo)); 877 ahints.ai_family = res0->ai_family; 878 ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM; 879 ahints.ai_protocol = uflag ? IPPROTO_UDP : IPPROTO_TCP; 880 ahints.ai_flags = AI_PASSIVE; 881 if ((error = getaddrinfo(sflag, pflag, &ahints, &ares))) 882 errx(1, "getaddrinfo: %s", gai_strerror(error)); 883 884 if (bind(s, (struct sockaddr *)ares->ai_addr, 885 ares->ai_addrlen) < 0) 886 err(1, "bind failed"); 887 freeaddrinfo(ares); 888 } 889 890 set_common_sockopts(s, res0->ai_family); 891 892 if (timeout_connect(s, res0->ai_addr, res0->ai_addrlen) == 0) 893 break; 894 if (vflag) 895 warn("connect to %s port %s (%s) failed", host, port, 896 uflag ? "udp" : "tcp"); 897 898 save_errno = errno; 899 close(s); 900 errno = save_errno; 901 s = -1; 902 } while ((res0 = res0->ai_next) != NULL); 903 904 freeaddrinfo(res); 905 906 return (s); 907 } 908 909 int 910 timeout_connect(int s, const struct sockaddr *name, socklen_t namelen) 911 { 912 struct pollfd pfd; 913 socklen_t optlen; 914 int optval; 915 int ret; 916 917 if ((ret = connect(s, name, namelen)) != 0 && errno == EINPROGRESS) { 918 pfd.fd = s; 919 pfd.events = POLLOUT; 920 if ((ret = poll(&pfd, 1, timeout)) == 1) { 921 optlen = sizeof(optval); 922 if ((ret = getsockopt(s, SOL_SOCKET, SO_ERROR, 923 &optval, &optlen)) == 0) { 924 errno = optval; 925 ret = optval == 0 ? 0 : -1; 926 } 927 } else if (ret == 0) { 928 errno = ETIMEDOUT; 929 ret = -1; 930 } else 931 err(1, "poll failed"); 932 } 933 934 return (ret); 935 } 936 937 /* 938 * local_listen() 939 * Returns a socket listening on a local port, binds to specified source 940 * address. Returns -1 on failure. 941 */ 942 int 943 local_listen(char *host, char *port, struct addrinfo hints) 944 { 945 struct addrinfo *res, *res0; 946 int s, save_errno; 947 #ifdef SO_REUSEPORT 948 int ret, x = 1; 949 #endif 950 int error; 951 952 /* Allow nodename to be null. */ 953 hints.ai_flags |= AI_PASSIVE; 954 955 /* 956 * In the case of binding to a wildcard address 957 * default to binding to an ipv4 address. 958 */ 959 if (host == NULL && hints.ai_family == AF_UNSPEC) 960 hints.ai_family = AF_INET; 961 962 if ((error = getaddrinfo(host, port, &hints, &res))) 963 errx(1, "getaddrinfo: %s", gai_strerror(error)); 964 965 res0 = res; 966 do { 967 if ((s = socket(res0->ai_family, res0->ai_socktype, 968 res0->ai_protocol)) < 0) 969 continue; 970 971 #ifdef SO_REUSEPORT 972 ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x)); 973 if (ret == -1) 974 err(1, NULL); 975 #endif 976 977 set_common_sockopts(s, res0->ai_family); 978 979 if (bind(s, (struct sockaddr *)res0->ai_addr, 980 res0->ai_addrlen) == 0) 981 break; 982 983 save_errno = errno; 984 close(s); 985 errno = save_errno; 986 s = -1; 987 } while ((res0 = res0->ai_next) != NULL); 988 989 if (!uflag && s != -1) { 990 if (listen(s, 1) < 0) 991 err(1, "listen"); 992 } 993 994 freeaddrinfo(res); 995 996 return (s); 997 } 998 999 /* 1000 * readwrite() 1001 * Loop that polls on the network file descriptor and stdin. 1002 */ 1003 void 1004 readwrite(int net_fd, struct tls *tls_ctx) 1005 { 1006 struct pollfd pfd[4]; 1007 int stdin_fd = STDIN_FILENO; 1008 int stdout_fd = STDOUT_FILENO; 1009 unsigned char netinbuf[BUFSIZE]; 1010 size_t netinbufpos = 0; 1011 unsigned char stdinbuf[BUFSIZE]; 1012 size_t stdinbufpos = 0; 1013 int n, num_fds; 1014 ssize_t ret; 1015 1016 /* don't read from stdin if requested */ 1017 if (dflag) 1018 stdin_fd = -1; 1019 1020 /* stdin */ 1021 pfd[POLL_STDIN].fd = stdin_fd; 1022 pfd[POLL_STDIN].events = POLLIN; 1023 1024 /* network out */ 1025 pfd[POLL_NETOUT].fd = net_fd; 1026 pfd[POLL_NETOUT].events = 0; 1027 1028 /* network in */ 1029 pfd[POLL_NETIN].fd = net_fd; 1030 pfd[POLL_NETIN].events = POLLIN; 1031 1032 /* stdout */ 1033 pfd[POLL_STDOUT].fd = stdout_fd; 1034 pfd[POLL_STDOUT].events = 0; 1035 1036 while (1) { 1037 /* both inputs are gone, buffers are empty, we are done */ 1038 if (pfd[POLL_STDIN].fd == -1 && pfd[POLL_NETIN].fd == -1 && 1039 stdinbufpos == 0 && netinbufpos == 0) { 1040 close(net_fd); 1041 return; 1042 } 1043 /* both outputs are gone, we can't continue */ 1044 if (pfd[POLL_NETOUT].fd == -1 && pfd[POLL_STDOUT].fd == -1) { 1045 close(net_fd); 1046 return; 1047 } 1048 /* listen and net in gone, queues empty, done */ 1049 if (lflag && pfd[POLL_NETIN].fd == -1 && 1050 stdinbufpos == 0 && netinbufpos == 0) { 1051 close(net_fd); 1052 return; 1053 } 1054 1055 /* help says -i is for "wait between lines sent". We read and 1056 * write arbitrary amounts of data, and we don't want to start 1057 * scanning for newlines, so this is as good as it gets */ 1058 if (iflag) 1059 sleep(iflag); 1060 1061 /* poll */ 1062 num_fds = poll(pfd, 4, timeout); 1063 1064 /* treat poll errors */ 1065 if (num_fds == -1) { 1066 close(net_fd); 1067 err(1, "polling error"); 1068 } 1069 1070 /* timeout happened */ 1071 if (num_fds == 0) 1072 return; 1073 1074 /* treat socket error conditions */ 1075 for (n = 0; n < 4; n++) { 1076 if (pfd[n].revents & (POLLERR|POLLNVAL)) { 1077 pfd[n].fd = -1; 1078 } 1079 } 1080 /* reading is possible after HUP */ 1081 if (pfd[POLL_STDIN].events & POLLIN && 1082 pfd[POLL_STDIN].revents & POLLHUP && 1083 !(pfd[POLL_STDIN].revents & POLLIN)) 1084 pfd[POLL_STDIN].fd = -1; 1085 1086 if (pfd[POLL_NETIN].events & POLLIN && 1087 pfd[POLL_NETIN].revents & POLLHUP && 1088 !(pfd[POLL_NETIN].revents & POLLIN)) 1089 pfd[POLL_NETIN].fd = -1; 1090 1091 if (pfd[POLL_NETOUT].revents & POLLHUP) { 1092 if (Nflag) 1093 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1094 pfd[POLL_NETOUT].fd = -1; 1095 } 1096 /* if HUP, stop watching stdout */ 1097 if (pfd[POLL_STDOUT].revents & POLLHUP) 1098 pfd[POLL_STDOUT].fd = -1; 1099 /* if no net out, stop watching stdin */ 1100 if (pfd[POLL_NETOUT].fd == -1) 1101 pfd[POLL_STDIN].fd = -1; 1102 /* if no stdout, stop watching net in */ 1103 if (pfd[POLL_STDOUT].fd == -1) { 1104 if (pfd[POLL_NETIN].fd != -1) 1105 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1106 pfd[POLL_NETIN].fd = -1; 1107 } 1108 1109 /* try to read from stdin */ 1110 if (pfd[POLL_STDIN].revents & POLLIN && stdinbufpos < BUFSIZE) { 1111 ret = fillbuf(pfd[POLL_STDIN].fd, stdinbuf, 1112 &stdinbufpos, NULL); 1113 if (ret == TLS_WANT_POLLIN) 1114 pfd[POLL_STDIN].events = POLLIN; 1115 else if (ret == TLS_WANT_POLLOUT) 1116 pfd[POLL_STDIN].events = POLLOUT; 1117 else if (ret == 0 || ret == -1) 1118 pfd[POLL_STDIN].fd = -1; 1119 /* read something - poll net out */ 1120 if (stdinbufpos > 0) 1121 pfd[POLL_NETOUT].events = POLLOUT; 1122 /* filled buffer - remove self from polling */ 1123 if (stdinbufpos == BUFSIZE) 1124 pfd[POLL_STDIN].events = 0; 1125 } 1126 /* try to write to network */ 1127 if (pfd[POLL_NETOUT].revents & POLLOUT && stdinbufpos > 0) { 1128 ret = drainbuf(pfd[POLL_NETOUT].fd, stdinbuf, 1129 &stdinbufpos, tls_ctx); 1130 if (ret == TLS_WANT_POLLIN) 1131 pfd[POLL_NETOUT].events = POLLIN; 1132 else if (ret == TLS_WANT_POLLOUT) 1133 pfd[POLL_NETOUT].events = POLLOUT; 1134 else if (ret == -1) 1135 pfd[POLL_NETOUT].fd = -1; 1136 /* buffer empty - remove self from polling */ 1137 if (stdinbufpos == 0) 1138 pfd[POLL_NETOUT].events = 0; 1139 /* buffer no longer full - poll stdin again */ 1140 if (stdinbufpos < BUFSIZE) 1141 pfd[POLL_STDIN].events = POLLIN; 1142 } 1143 /* try to read from network */ 1144 if (pfd[POLL_NETIN].revents & POLLIN && netinbufpos < BUFSIZE) { 1145 ret = fillbuf(pfd[POLL_NETIN].fd, netinbuf, 1146 &netinbufpos, tls_ctx); 1147 if (ret == TLS_WANT_POLLIN) 1148 pfd[POLL_NETIN].events = POLLIN; 1149 else if (ret == TLS_WANT_POLLOUT) 1150 pfd[POLL_NETIN].events = POLLOUT; 1151 else if (ret == -1) 1152 pfd[POLL_NETIN].fd = -1; 1153 /* eof on net in - remove from pfd */ 1154 if (ret == 0) { 1155 shutdown(pfd[POLL_NETIN].fd, SHUT_RD); 1156 pfd[POLL_NETIN].fd = -1; 1157 } 1158 /* read something - poll stdout */ 1159 if (netinbufpos > 0) 1160 pfd[POLL_STDOUT].events = POLLOUT; 1161 /* filled buffer - remove self from polling */ 1162 if (netinbufpos == BUFSIZE) 1163 pfd[POLL_NETIN].events = 0; 1164 /* handle telnet */ 1165 if (tflag) 1166 atelnet(pfd[POLL_NETIN].fd, netinbuf, 1167 netinbufpos); 1168 } 1169 /* try to write to stdout */ 1170 if (pfd[POLL_STDOUT].revents & POLLOUT && netinbufpos > 0) { 1171 ret = drainbuf(pfd[POLL_STDOUT].fd, netinbuf, 1172 &netinbufpos, NULL); 1173 if (ret == TLS_WANT_POLLIN) 1174 pfd[POLL_STDOUT].events = POLLIN; 1175 else if (ret == TLS_WANT_POLLOUT) 1176 pfd[POLL_STDOUT].events = POLLOUT; 1177 else if (ret == -1) 1178 pfd[POLL_STDOUT].fd = -1; 1179 /* buffer empty - remove self from polling */ 1180 if (netinbufpos == 0) 1181 pfd[POLL_STDOUT].events = 0; 1182 /* buffer no longer full - poll net in again */ 1183 if (netinbufpos < BUFSIZE) 1184 pfd[POLL_NETIN].events = POLLIN; 1185 } 1186 1187 /* stdin gone and queue empty? */ 1188 if (pfd[POLL_STDIN].fd == -1 && stdinbufpos == 0) { 1189 if (pfd[POLL_NETOUT].fd != -1 && Nflag) 1190 shutdown(pfd[POLL_NETOUT].fd, SHUT_WR); 1191 pfd[POLL_NETOUT].fd = -1; 1192 } 1193 /* net in gone and queue empty? */ 1194 if (pfd[POLL_NETIN].fd == -1 && netinbufpos == 0) { 1195 pfd[POLL_STDOUT].fd = -1; 1196 } 1197 } 1198 } 1199 1200 ssize_t 1201 drainbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1202 { 1203 ssize_t n; 1204 ssize_t adjust; 1205 1206 if (tls) 1207 n = tls_write(tls, buf, *bufpos); 1208 else { 1209 n = write(fd, buf, *bufpos); 1210 /* don't treat EAGAIN, EINTR as error */ 1211 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1212 n = TLS_WANT_POLLOUT; 1213 } 1214 if (n <= 0) 1215 return n; 1216 /* adjust buffer */ 1217 adjust = *bufpos - n; 1218 if (adjust > 0) 1219 memmove(buf, buf + n, adjust); 1220 *bufpos -= n; 1221 return n; 1222 } 1223 1224 ssize_t 1225 fillbuf(int fd, unsigned char *buf, size_t *bufpos, struct tls *tls) 1226 { 1227 size_t num = BUFSIZE - *bufpos; 1228 ssize_t n; 1229 1230 if (tls) 1231 n = tls_read(tls, buf + *bufpos, num); 1232 else { 1233 n = read(fd, buf + *bufpos, num); 1234 /* don't treat EAGAIN, EINTR as error */ 1235 if (n == -1 && (errno == EAGAIN || errno == EINTR)) 1236 n = TLS_WANT_POLLIN; 1237 } 1238 if (n <= 0) 1239 return n; 1240 *bufpos += n; 1241 return n; 1242 } 1243 1244 /* 1245 * fdpass() 1246 * Pass the connected file descriptor to stdout and exit. 1247 */ 1248 void 1249 fdpass(int nfd) 1250 { 1251 struct msghdr mh; 1252 union { 1253 struct cmsghdr hdr; 1254 char buf[CMSG_SPACE(sizeof(int))]; 1255 } cmsgbuf; 1256 struct cmsghdr *cmsg; 1257 struct iovec iov; 1258 char c = '\0'; 1259 ssize_t r; 1260 struct pollfd pfd; 1261 1262 /* Avoid obvious stupidity */ 1263 if (isatty(STDOUT_FILENO)) 1264 errx(1, "Cannot pass file descriptor to tty"); 1265 1266 bzero(&mh, sizeof(mh)); 1267 bzero(&cmsgbuf, sizeof(cmsgbuf)); 1268 bzero(&iov, sizeof(iov)); 1269 1270 mh.msg_control = (caddr_t)&cmsgbuf.buf; 1271 mh.msg_controllen = sizeof(cmsgbuf.buf); 1272 cmsg = CMSG_FIRSTHDR(&mh); 1273 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 1274 cmsg->cmsg_level = SOL_SOCKET; 1275 cmsg->cmsg_type = SCM_RIGHTS; 1276 *(int *)CMSG_DATA(cmsg) = nfd; 1277 1278 iov.iov_base = &c; 1279 iov.iov_len = 1; 1280 mh.msg_iov = &iov; 1281 mh.msg_iovlen = 1; 1282 1283 bzero(&pfd, sizeof(pfd)); 1284 pfd.fd = STDOUT_FILENO; 1285 pfd.events = POLLOUT; 1286 for (;;) { 1287 r = sendmsg(STDOUT_FILENO, &mh, 0); 1288 if (r == -1) { 1289 if (errno == EAGAIN || errno == EINTR) { 1290 if (poll(&pfd, 1, -1) == -1) 1291 err(1, "poll"); 1292 continue; 1293 } 1294 err(1, "sendmsg"); 1295 } else if (r != 1) 1296 errx(1, "sendmsg: unexpected return value %zd", r); 1297 else 1298 break; 1299 } 1300 exit(0); 1301 } 1302 1303 /* Deal with RFC 854 WILL/WONT DO/DONT negotiation. */ 1304 void 1305 atelnet(int nfd, unsigned char *buf, unsigned int size) 1306 { 1307 unsigned char *p, *end; 1308 unsigned char obuf[4]; 1309 1310 if (size < 3) 1311 return; 1312 end = buf + size - 2; 1313 1314 for (p = buf; p < end; p++) { 1315 if (*p != IAC) 1316 continue; 1317 1318 obuf[0] = IAC; 1319 p++; 1320 if ((*p == WILL) || (*p == WONT)) 1321 obuf[1] = DONT; 1322 else if ((*p == DO) || (*p == DONT)) 1323 obuf[1] = WONT; 1324 else 1325 continue; 1326 1327 p++; 1328 obuf[2] = *p; 1329 if (atomicio(vwrite, nfd, obuf, 3) != 3) 1330 warn("Write Error!"); 1331 } 1332 } 1333 1334 1335 static int 1336 strtoport(char *portstr, int udp) 1337 { 1338 struct servent *entry; 1339 const char *errstr; 1340 char *proto; 1341 int port = -1; 1342 1343 proto = udp ? "udp" : "tcp"; 1344 1345 port = strtonum(portstr, 1, PORT_MAX, &errstr); 1346 if (errstr == NULL) 1347 return port; 1348 if (errno != EINVAL) 1349 errx(1, "port number %s: %s", errstr, portstr); 1350 if ((entry = getservbyname(portstr, proto)) == NULL) 1351 errx(1, "service \"%s\" unknown", portstr); 1352 return ntohs(entry->s_port); 1353 } 1354 1355 /* 1356 * build_ports() 1357 * Build an array of ports in portlist[], listing each port 1358 * that we should try to connect to. 1359 */ 1360 void 1361 build_ports(char *p) 1362 { 1363 char *n; 1364 int hi, lo, cp; 1365 int x = 0; 1366 1367 if ((n = strchr(p, '-')) != NULL) { 1368 *n = '\0'; 1369 n++; 1370 1371 /* Make sure the ports are in order: lowest->highest. */ 1372 hi = strtoport(n, uflag); 1373 lo = strtoport(p, uflag); 1374 if (lo > hi) { 1375 cp = hi; 1376 hi = lo; 1377 lo = cp; 1378 } 1379 1380 /* 1381 * Initialize portlist with a random permutation. Based on 1382 * Knuth, as in ip_randomid() in sys/netinet/ip_id.c. 1383 */ 1384 if (rflag) { 1385 for (x = 0; x <= hi - lo; x++) { 1386 cp = arc4random_uniform(x + 1); 1387 portlist[x] = portlist[cp]; 1388 if (asprintf(&portlist[cp], "%d", x + lo) < 0) 1389 err(1, "asprintf"); 1390 } 1391 } else { /* Load ports sequentially. */ 1392 for (cp = lo; cp <= hi; cp++) { 1393 if (asprintf(&portlist[x], "%d", cp) < 0) 1394 err(1, "asprintf"); 1395 x++; 1396 } 1397 } 1398 } else { 1399 char *tmp; 1400 1401 hi = strtoport(p, uflag); 1402 if (asprintf(&tmp, "%d", hi) != -1) 1403 portlist[0] = tmp; 1404 else 1405 err(1, NULL); 1406 } 1407 } 1408 1409 /* 1410 * udptest() 1411 * Do a few writes to see if the UDP port is there. 1412 * Fails once PF state table is full. 1413 */ 1414 int 1415 udptest(int s) 1416 { 1417 int i, ret; 1418 1419 for (i = 0; i <= 3; i++) { 1420 if (write(s, "X", 1) == 1) 1421 ret = 1; 1422 else 1423 ret = -1; 1424 } 1425 return (ret); 1426 } 1427 1428 void 1429 set_common_sockopts(int s, int af) 1430 { 1431 int x = 1; 1432 1433 #ifdef TCP_MD5SIG 1434 if (Sflag) { 1435 if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG, 1436 &x, sizeof(x)) == -1) 1437 err(1, NULL); 1438 } 1439 #endif 1440 if (Dflag) { 1441 if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 1442 &x, sizeof(x)) == -1) 1443 err(1, NULL); 1444 } 1445 if (Tflag != -1) { 1446 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1447 IP_TOS, &Tflag, sizeof(Tflag)) == -1) 1448 err(1, "set IP ToS"); 1449 1450 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1451 IPV6_TCLASS, &Tflag, sizeof(Tflag)) == -1) 1452 err(1, "set IPv6 traffic class"); 1453 } 1454 if (Iflag) { 1455 if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, 1456 &Iflag, sizeof(Iflag)) == -1) 1457 err(1, "set TCP receive buffer size"); 1458 } 1459 if (Oflag) { 1460 if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, 1461 &Oflag, sizeof(Oflag)) == -1) 1462 err(1, "set TCP send buffer size"); 1463 } 1464 1465 if (ttl != -1) { 1466 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1467 IP_TTL, &ttl, sizeof(ttl))) 1468 err(1, "set IP TTL"); 1469 1470 else if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1471 IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))) 1472 err(1, "set IPv6 unicast hops"); 1473 } 1474 1475 if (minttl != -1) { 1476 #ifdef IP_MINTTL 1477 if (af == AF_INET && setsockopt(s, IPPROTO_IP, 1478 IP_MINTTL, &minttl, sizeof(minttl))) 1479 err(1, "set IP min TTL"); 1480 #endif 1481 1482 #ifdef IPV6_MINHOPCOUNT 1483 if (af == AF_INET6 && setsockopt(s, IPPROTO_IPV6, 1484 IPV6_MINHOPCOUNT, &minttl, sizeof(minttl))) 1485 err(1, "set IPv6 min hop count"); 1486 #endif 1487 } 1488 } 1489 1490 int 1491 map_tos(char *s, int *val) 1492 { 1493 /* DiffServ Codepoints and other TOS mappings */ 1494 const struct toskeywords { 1495 const char *keyword; 1496 int val; 1497 } *t, toskeywords[] = { 1498 { "af11", IPTOS_DSCP_AF11 }, 1499 { "af12", IPTOS_DSCP_AF12 }, 1500 { "af13", IPTOS_DSCP_AF13 }, 1501 { "af21", IPTOS_DSCP_AF21 }, 1502 { "af22", IPTOS_DSCP_AF22 }, 1503 { "af23", IPTOS_DSCP_AF23 }, 1504 { "af31", IPTOS_DSCP_AF31 }, 1505 { "af32", IPTOS_DSCP_AF32 }, 1506 { "af33", IPTOS_DSCP_AF33 }, 1507 { "af41", IPTOS_DSCP_AF41 }, 1508 { "af42", IPTOS_DSCP_AF42 }, 1509 { "af43", IPTOS_DSCP_AF43 }, 1510 { "critical", IPTOS_PREC_CRITIC_ECP }, 1511 { "cs0", IPTOS_DSCP_CS0 }, 1512 { "cs1", IPTOS_DSCP_CS1 }, 1513 { "cs2", IPTOS_DSCP_CS2 }, 1514 { "cs3", IPTOS_DSCP_CS3 }, 1515 { "cs4", IPTOS_DSCP_CS4 }, 1516 { "cs5", IPTOS_DSCP_CS5 }, 1517 { "cs6", IPTOS_DSCP_CS6 }, 1518 { "cs7", IPTOS_DSCP_CS7 }, 1519 { "ef", IPTOS_DSCP_EF }, 1520 { "inetcontrol", IPTOS_PREC_INTERNETCONTROL }, 1521 { "lowdelay", IPTOS_LOWDELAY }, 1522 { "netcontrol", IPTOS_PREC_NETCONTROL }, 1523 { "reliability", IPTOS_RELIABILITY }, 1524 { "throughput", IPTOS_THROUGHPUT }, 1525 { NULL, -1 }, 1526 }; 1527 1528 for (t = toskeywords; t->keyword != NULL; t++) { 1529 if (strcmp(s, t->keyword) == 0) { 1530 *val = t->val; 1531 return (1); 1532 } 1533 } 1534 1535 return (0); 1536 } 1537 1538 int 1539 map_tls(char *s, int *val) 1540 { 1541 const struct tlskeywords { 1542 const char *keyword; 1543 int val; 1544 } *t, tlskeywords[] = { 1545 { "tlslegacy", TLS_LEGACY }, 1546 { "noverify", TLS_NOVERIFY }, 1547 { "noname", TLS_NONAME }, 1548 { "clientcert", TLS_CCERT}, 1549 { NULL, -1 }, 1550 }; 1551 1552 for (t = tlskeywords; t->keyword != NULL; t++) { 1553 if (strcmp(s, t->keyword) == 0) { 1554 *val |= t->val; 1555 return (1); 1556 } 1557 } 1558 return (0); 1559 } 1560 1561 void 1562 report_tls(struct tls * tls_ctx, char * host, char *tls_expectname) 1563 { 1564 time_t t; 1565 fprintf(stderr, "TLS handshake negotiated %s/%s with host %s\n", 1566 tls_conn_version(tls_ctx), tls_conn_cipher(tls_ctx), host); 1567 fprintf(stderr, "Peer name: %s\n", 1568 tls_expectname ? tls_expectname : host); 1569 if (tls_peer_cert_subject(tls_ctx)) 1570 fprintf(stderr, "Subject: %s\n", 1571 tls_peer_cert_subject(tls_ctx)); 1572 if (tls_peer_cert_issuer(tls_ctx)) 1573 fprintf(stderr, "Issuer: %s\n", 1574 tls_peer_cert_issuer(tls_ctx)); 1575 if ((t = tls_peer_cert_notbefore(tls_ctx)) != -1) 1576 fprintf(stderr, "Valid From: %s", ctime(&t)); 1577 if ((t = tls_peer_cert_notafter(tls_ctx)) != -1) 1578 fprintf(stderr, "Valid Until: %s", ctime(&t)); 1579 if (tls_peer_cert_hash(tls_ctx)) 1580 fprintf(stderr, "Cert Hash: %s\n", 1581 tls_peer_cert_hash(tls_ctx)); 1582 } 1583 1584 void 1585 report_connect(const struct sockaddr *sa, socklen_t salen, char *path) 1586 { 1587 char remote_host[NI_MAXHOST]; 1588 char remote_port[NI_MAXSERV]; 1589 int herr; 1590 int flags = NI_NUMERICSERV; 1591 1592 if (path != NULL) { 1593 fprintf(stderr, "Connection on %s received!\n", path); 1594 return; 1595 } 1596 1597 if (nflag) 1598 flags |= NI_NUMERICHOST; 1599 1600 if ((herr = getnameinfo(sa, salen, 1601 remote_host, sizeof(remote_host), 1602 remote_port, sizeof(remote_port), 1603 flags)) != 0) { 1604 if (herr == EAI_SYSTEM) 1605 err(1, "getnameinfo"); 1606 else 1607 errx(1, "getnameinfo: %s", gai_strerror(herr)); 1608 } 1609 1610 fprintf(stderr, 1611 "Connection from %s %s " 1612 "received!\n", remote_host, remote_port); 1613 } 1614 1615 void 1616 help(void) 1617 { 1618 usage(0); 1619 fprintf(stderr, "\tCommand Summary:\n\ 1620 \t-4 Use IPv4\n\ 1621 \t-6 Use IPv6\n\ 1622 \t-C certfile Public key file\n\ 1623 \t-c Use TLS\n\ 1624 \t-D Enable the debug socket option\n\ 1625 \t-d Detach from stdin\n\ 1626 \t-e name\t Required name in peer certificate\n\ 1627 \t-F Pass socket fd\n\ 1628 \t-H hash\t Hash string of peer certificate\n\ 1629 \t-h This help text\n\ 1630 \t-I length TCP receive buffer length\n\ 1631 \t-i interval Delay interval for lines sent, ports scanned\n\ 1632 \t-K keyfile Private key file\n\ 1633 \t-k Keep inbound sockets open for multiple connects\n\ 1634 \t-l Listen mode, for inbound connects\n\ 1635 \t-M ttl Outgoing TTL / Hop Limit\n\ 1636 \t-m minttl Minimum incoming TTL / Hop Limit\n\ 1637 \t-N Shutdown the network socket after EOF on stdin\n\ 1638 \t-n Suppress name/port resolutions\n\ 1639 \t-O length TCP send buffer length\n\ 1640 \t-P proxyuser\tUsername for proxy authentication\n\ 1641 \t-p port\t Specify local port for remote connects\n\ 1642 \t-R CAfile CA bundle\n\ 1643 \t-r Randomize remote ports\n" 1644 #ifdef TCP_MD5SIG 1645 "\ 1646 \t-S Enable the TCP MD5 signature option\n" 1647 #endif 1648 "\ 1649 \t-s source Local source address\n\ 1650 \t-T keyword TOS value or TLS options\n\ 1651 \t-t Answer TELNET negotiation\n\ 1652 \t-U Use UNIX domain socket\n\ 1653 \t-u UDP mode\n" 1654 #ifdef SO_RTABLE 1655 "\ 1656 \t-V rtable Specify alternate routing table\n" 1657 #endif 1658 "\ 1659 \t-v Verbose\n\ 1660 \t-w timeout Timeout for connects and final net reads\n\ 1661 \t-X proto Proxy protocol: \"4\", \"5\" (SOCKS) or \"connect\"\n\ 1662 \t-x addr[:port]\tSpecify proxy address and port\n\ 1663 \t-z Zero-I/O mode [used for scanning]\n\ 1664 Port numbers can be individual or ranges: lo-hi [inclusive]\n"); 1665 exit(1); 1666 } 1667 1668 void 1669 usage(int ret) 1670 { 1671 fprintf(stderr, 1672 "usage: nc [-46cDdFhklNnrStUuvz] [-C certfile] [-e name] " 1673 "[-H hash] [-I length]\n" 1674 "\t [-i interval] [-K keyfile] [-M ttl] [-m minttl] [-O length]\n" 1675 "\t [-P proxy_username] [-p source_port] [-R CAfile] [-s source]\n" 1676 "\t [-T keyword] [-V rtable] [-w timeout] [-X proxy_protocol]\n" 1677 "\t [-x proxy_address[:port]] [destination] [port]\n"); 1678 if (ret) 1679 exit(1); 1680 } 1681