1 /* $OpenBSD: ssh-keyscan.c,v 1.89 2013/12/06 13:39:49 markus Exp $ */ 2 /* 3 * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>. 4 * 5 * Modification and redistribution in source and binary forms is 6 * permitted provided that due credit is given to the author and the 7 * OpenBSD project by leaving this copyright notice intact. 8 */ 9 10 #include "includes.h" 11 12 #include "openbsd-compat/sys-queue.h" 13 #include <sys/resource.h> 14 #ifdef HAVE_SYS_TIME_H 15 # include <sys/time.h> 16 #endif 17 18 #include <netinet/in.h> 19 #include <arpa/inet.h> 20 21 #include <openssl/bn.h> 22 23 #include <netdb.h> 24 #include <errno.h> 25 #include <setjmp.h> 26 #include <stdarg.h> 27 #include <stdio.h> 28 #include <stdlib.h> 29 #include <signal.h> 30 #include <string.h> 31 #include <unistd.h> 32 33 #include "xmalloc.h" 34 #include "ssh.h" 35 #include "ssh1.h" 36 #include "buffer.h" 37 #include "key.h" 38 #include "cipher.h" 39 #include "kex.h" 40 #include "compat.h" 41 #include "myproposal.h" 42 #include "packet.h" 43 #include "dispatch.h" 44 #include "log.h" 45 #include "atomicio.h" 46 #include "misc.h" 47 #include "hostfile.h" 48 49 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line. 50 Default value is AF_UNSPEC means both IPv4 and IPv6. */ 51 int IPv4or6 = AF_UNSPEC; 52 53 int ssh_port = SSH_DEFAULT_PORT; 54 55 #define KT_RSA1 1 56 #define KT_DSA 2 57 #define KT_RSA 4 58 #define KT_ECDSA 8 59 #define KT_ED25519 16 60 61 int get_keytypes = KT_RSA|KT_ECDSA;/* Get RSA and ECDSA keys by default */ 62 63 int hash_hosts = 0; /* Hash hostname on output */ 64 65 #define MAXMAXFD 256 66 67 /* The number of seconds after which to give up on a TCP connection */ 68 int timeout = 5; 69 70 int maxfd; 71 #define MAXCON (maxfd - 10) 72 73 extern char *__progname; 74 fd_set *read_wait; 75 size_t read_wait_nfdset; 76 int ncon; 77 int nonfatal_fatal = 0; 78 jmp_buf kexjmp; 79 Key *kexjmp_key; 80 81 /* 82 * Keep a connection structure for each file descriptor. The state 83 * associated with file descriptor n is held in fdcon[n]. 84 */ 85 typedef struct Connection { 86 u_char c_status; /* State of connection on this file desc. */ 87 #define CS_UNUSED 0 /* File descriptor unused */ 88 #define CS_CON 1 /* Waiting to connect/read greeting */ 89 #define CS_SIZE 2 /* Waiting to read initial packet size */ 90 #define CS_KEYS 3 /* Waiting to read public key packet */ 91 int c_fd; /* Quick lookup: c->c_fd == c - fdcon */ 92 int c_plen; /* Packet length field for ssh packet */ 93 int c_len; /* Total bytes which must be read. */ 94 int c_off; /* Length of data read so far. */ 95 int c_keytype; /* Only one of KT_RSA1, KT_DSA, or KT_RSA */ 96 char *c_namebase; /* Address to free for c_name and c_namelist */ 97 char *c_name; /* Hostname of connection for errors */ 98 char *c_namelist; /* Pointer to other possible addresses */ 99 char *c_output_name; /* Hostname of connection for output */ 100 char *c_data; /* Data read from this fd */ 101 Kex *c_kex; /* The key-exchange struct for ssh2 */ 102 struct timeval c_tv; /* Time at which connection gets aborted */ 103 TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */ 104 } con; 105 106 TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */ 107 con *fdcon; 108 109 static int 110 fdlim_get(int hard) 111 { 112 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE) 113 struct rlimit rlfd; 114 115 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0) 116 return (-1); 117 if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY) 118 return SSH_SYSFDMAX; 119 else 120 return hard ? rlfd.rlim_max : rlfd.rlim_cur; 121 #else 122 return SSH_SYSFDMAX; 123 #endif 124 } 125 126 static int 127 fdlim_set(int lim) 128 { 129 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE) 130 struct rlimit rlfd; 131 #endif 132 133 if (lim <= 0) 134 return (-1); 135 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE) 136 if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0) 137 return (-1); 138 rlfd.rlim_cur = lim; 139 if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0) 140 return (-1); 141 #elif defined (HAVE_SETDTABLESIZE) 142 setdtablesize(lim); 143 #endif 144 return (0); 145 } 146 147 /* 148 * This is an strsep function that returns a null field for adjacent 149 * separators. This is the same as the 4.4BSD strsep, but different from the 150 * one in the GNU libc. 151 */ 152 static char * 153 xstrsep(char **str, const char *delim) 154 { 155 char *s, *e; 156 157 if (!**str) 158 return (NULL); 159 160 s = *str; 161 e = s + strcspn(s, delim); 162 163 if (*e != '\0') 164 *e++ = '\0'; 165 *str = e; 166 167 return (s); 168 } 169 170 /* 171 * Get the next non-null token (like GNU strsep). Strsep() will return a 172 * null token for two adjacent separators, so we may have to loop. 173 */ 174 static char * 175 strnnsep(char **stringp, char *delim) 176 { 177 char *tok; 178 179 do { 180 tok = xstrsep(stringp, delim); 181 } while (tok && *tok == '\0'); 182 return (tok); 183 } 184 185 static Key * 186 keygrab_ssh1(con *c) 187 { 188 static Key *rsa; 189 static Buffer msg; 190 191 if (rsa == NULL) { 192 buffer_init(&msg); 193 rsa = key_new(KEY_RSA1); 194 } 195 buffer_append(&msg, c->c_data, c->c_plen); 196 buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */ 197 if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) { 198 error("%s: invalid packet type", c->c_name); 199 buffer_clear(&msg); 200 return NULL; 201 } 202 buffer_consume(&msg, 8); /* cookie */ 203 204 /* server key */ 205 (void) buffer_get_int(&msg); 206 buffer_get_bignum(&msg, rsa->rsa->e); 207 buffer_get_bignum(&msg, rsa->rsa->n); 208 209 /* host key */ 210 (void) buffer_get_int(&msg); 211 buffer_get_bignum(&msg, rsa->rsa->e); 212 buffer_get_bignum(&msg, rsa->rsa->n); 213 214 buffer_clear(&msg); 215 216 return (rsa); 217 } 218 219 static int 220 hostjump(Key *hostkey) 221 { 222 kexjmp_key = hostkey; 223 longjmp(kexjmp, 1); 224 } 225 226 static int 227 ssh2_capable(int remote_major, int remote_minor) 228 { 229 switch (remote_major) { 230 case 1: 231 if (remote_minor == 99) 232 return 1; 233 break; 234 case 2: 235 return 1; 236 default: 237 break; 238 } 239 return 0; 240 } 241 242 static Key * 243 keygrab_ssh2(con *c) 244 { 245 int j; 246 247 packet_set_connection(c->c_fd, c->c_fd); 248 enable_compat20(); 249 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = 250 c->c_keytype == KT_DSA ? "ssh-dss" : 251 (c->c_keytype == KT_RSA ? "ssh-rsa" : 252 (c->c_keytype == KT_ED25519 ? "ssh-ed25519" : 253 "ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521")); 254 c->c_kex = kex_setup(myproposal); 255 c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; 256 c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; 257 c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; 258 c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; 259 c->c_kex->kex[KEX_ECDH_SHA2] = kexecdh_client; 260 c->c_kex->kex[KEX_C25519_SHA256] = kexc25519_client; 261 c->c_kex->verify_host_key = hostjump; 262 263 if (!(j = setjmp(kexjmp))) { 264 nonfatal_fatal = 1; 265 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex); 266 fprintf(stderr, "Impossible! dispatch_run() returned!\n"); 267 exit(1); 268 } 269 nonfatal_fatal = 0; 270 free(c->c_kex); 271 c->c_kex = NULL; 272 packet_close(); 273 274 return j < 0? NULL : kexjmp_key; 275 } 276 277 static void 278 keyprint(con *c, Key *key) 279 { 280 char *host = c->c_output_name ? c->c_output_name : c->c_name; 281 282 if (!key) 283 return; 284 if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL) 285 fatal("host_hash failed"); 286 287 fprintf(stdout, "%s ", host); 288 key_write(key, stdout); 289 fputs("\n", stdout); 290 } 291 292 static int 293 tcpconnect(char *host) 294 { 295 struct addrinfo hints, *ai, *aitop; 296 char strport[NI_MAXSERV]; 297 int gaierr, s = -1; 298 299 snprintf(strport, sizeof strport, "%d", ssh_port); 300 memset(&hints, 0, sizeof(hints)); 301 hints.ai_family = IPv4or6; 302 hints.ai_socktype = SOCK_STREAM; 303 if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) 304 fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr)); 305 for (ai = aitop; ai; ai = ai->ai_next) { 306 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol); 307 if (s < 0) { 308 error("socket: %s", strerror(errno)); 309 continue; 310 } 311 if (set_nonblock(s) == -1) 312 fatal("%s: set_nonblock(%d)", __func__, s); 313 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 && 314 errno != EINPROGRESS) 315 error("connect (`%s'): %s", host, strerror(errno)); 316 else 317 break; 318 close(s); 319 s = -1; 320 } 321 freeaddrinfo(aitop); 322 return s; 323 } 324 325 static int 326 conalloc(char *iname, char *oname, int keytype) 327 { 328 char *namebase, *name, *namelist; 329 int s; 330 331 namebase = namelist = xstrdup(iname); 332 333 do { 334 name = xstrsep(&namelist, ","); 335 if (!name) { 336 free(namebase); 337 return (-1); 338 } 339 } while ((s = tcpconnect(name)) < 0); 340 341 if (s >= maxfd) 342 fatal("conalloc: fdno %d too high", s); 343 if (fdcon[s].c_status) 344 fatal("conalloc: attempt to reuse fdno %d", s); 345 346 fdcon[s].c_fd = s; 347 fdcon[s].c_status = CS_CON; 348 fdcon[s].c_namebase = namebase; 349 fdcon[s].c_name = name; 350 fdcon[s].c_namelist = namelist; 351 fdcon[s].c_output_name = xstrdup(oname); 352 fdcon[s].c_data = (char *) &fdcon[s].c_plen; 353 fdcon[s].c_len = 4; 354 fdcon[s].c_off = 0; 355 fdcon[s].c_keytype = keytype; 356 gettimeofday(&fdcon[s].c_tv, NULL); 357 fdcon[s].c_tv.tv_sec += timeout; 358 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link); 359 FD_SET(s, read_wait); 360 ncon++; 361 return (s); 362 } 363 364 static void 365 confree(int s) 366 { 367 if (s >= maxfd || fdcon[s].c_status == CS_UNUSED) 368 fatal("confree: attempt to free bad fdno %d", s); 369 close(s); 370 free(fdcon[s].c_namebase); 371 free(fdcon[s].c_output_name); 372 if (fdcon[s].c_status == CS_KEYS) 373 free(fdcon[s].c_data); 374 fdcon[s].c_status = CS_UNUSED; 375 fdcon[s].c_keytype = 0; 376 TAILQ_REMOVE(&tq, &fdcon[s], c_link); 377 FD_CLR(s, read_wait); 378 ncon--; 379 } 380 381 static void 382 contouch(int s) 383 { 384 TAILQ_REMOVE(&tq, &fdcon[s], c_link); 385 gettimeofday(&fdcon[s].c_tv, NULL); 386 fdcon[s].c_tv.tv_sec += timeout; 387 TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link); 388 } 389 390 static int 391 conrecycle(int s) 392 { 393 con *c = &fdcon[s]; 394 int ret; 395 396 ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype); 397 confree(s); 398 return (ret); 399 } 400 401 static void 402 congreet(int s) 403 { 404 int n = 0, remote_major = 0, remote_minor = 0; 405 char buf[256], *cp; 406 char remote_version[sizeof buf]; 407 size_t bufsiz; 408 con *c = &fdcon[s]; 409 410 for (;;) { 411 memset(buf, '\0', sizeof(buf)); 412 bufsiz = sizeof(buf); 413 cp = buf; 414 while (bufsiz-- && 415 (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') { 416 if (*cp == '\r') 417 *cp = '\n'; 418 cp++; 419 } 420 if (n != 1 || strncmp(buf, "SSH-", 4) == 0) 421 break; 422 } 423 if (n == 0) { 424 switch (errno) { 425 case EPIPE: 426 error("%s: Connection closed by remote host", c->c_name); 427 break; 428 case ECONNREFUSED: 429 break; 430 default: 431 error("read (%s): %s", c->c_name, strerror(errno)); 432 break; 433 } 434 conrecycle(s); 435 return; 436 } 437 if (*cp != '\n' && *cp != '\r') { 438 error("%s: bad greeting", c->c_name); 439 confree(s); 440 return; 441 } 442 *cp = '\0'; 443 if (sscanf(buf, "SSH-%d.%d-%[^\n]\n", 444 &remote_major, &remote_minor, remote_version) == 3) 445 compat_datafellows(remote_version); 446 else 447 datafellows = 0; 448 if (c->c_keytype != KT_RSA1) { 449 if (!ssh2_capable(remote_major, remote_minor)) { 450 debug("%s doesn't support ssh2", c->c_name); 451 confree(s); 452 return; 453 } 454 } else if (remote_major != 1) { 455 debug("%s doesn't support ssh1", c->c_name); 456 confree(s); 457 return; 458 } 459 fprintf(stderr, "# %s %s\n", c->c_name, chop(buf)); 460 n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n", 461 c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2, 462 c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2); 463 if (n < 0 || (size_t)n >= sizeof(buf)) { 464 error("snprintf: buffer too small"); 465 confree(s); 466 return; 467 } 468 if (atomicio(vwrite, s, buf, n) != (size_t)n) { 469 error("write (%s): %s", c->c_name, strerror(errno)); 470 confree(s); 471 return; 472 } 473 if (c->c_keytype != KT_RSA1) { 474 keyprint(c, keygrab_ssh2(c)); 475 confree(s); 476 return; 477 } 478 c->c_status = CS_SIZE; 479 contouch(s); 480 } 481 482 static void 483 conread(int s) 484 { 485 con *c = &fdcon[s]; 486 size_t n; 487 488 if (c->c_status == CS_CON) { 489 congreet(s); 490 return; 491 } 492 n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off); 493 if (n == 0) { 494 error("read (%s): %s", c->c_name, strerror(errno)); 495 confree(s); 496 return; 497 } 498 c->c_off += n; 499 500 if (c->c_off == c->c_len) 501 switch (c->c_status) { 502 case CS_SIZE: 503 c->c_plen = htonl(c->c_plen); 504 c->c_len = c->c_plen + 8 - (c->c_plen & 7); 505 c->c_off = 0; 506 c->c_data = xmalloc(c->c_len); 507 c->c_status = CS_KEYS; 508 break; 509 case CS_KEYS: 510 keyprint(c, keygrab_ssh1(c)); 511 confree(s); 512 return; 513 default: 514 fatal("conread: invalid status %d", c->c_status); 515 break; 516 } 517 518 contouch(s); 519 } 520 521 static void 522 conloop(void) 523 { 524 struct timeval seltime, now; 525 fd_set *r, *e; 526 con *c; 527 int i; 528 529 gettimeofday(&now, NULL); 530 c = TAILQ_FIRST(&tq); 531 532 if (c && (c->c_tv.tv_sec > now.tv_sec || 533 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) { 534 seltime = c->c_tv; 535 seltime.tv_sec -= now.tv_sec; 536 seltime.tv_usec -= now.tv_usec; 537 if (seltime.tv_usec < 0) { 538 seltime.tv_usec += 1000000; 539 seltime.tv_sec--; 540 } 541 } else 542 timerclear(&seltime); 543 544 r = xcalloc(read_wait_nfdset, sizeof(fd_mask)); 545 e = xcalloc(read_wait_nfdset, sizeof(fd_mask)); 546 memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask)); 547 memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask)); 548 549 while (select(maxfd, r, NULL, e, &seltime) == -1 && 550 (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK)) 551 ; 552 553 for (i = 0; i < maxfd; i++) { 554 if (FD_ISSET(i, e)) { 555 error("%s: exception!", fdcon[i].c_name); 556 confree(i); 557 } else if (FD_ISSET(i, r)) 558 conread(i); 559 } 560 free(r); 561 free(e); 562 563 c = TAILQ_FIRST(&tq); 564 while (c && (c->c_tv.tv_sec < now.tv_sec || 565 (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) { 566 int s = c->c_fd; 567 568 c = TAILQ_NEXT(c, c_link); 569 conrecycle(s); 570 } 571 } 572 573 static void 574 do_host(char *host) 575 { 576 char *name = strnnsep(&host, " \t\n"); 577 int j; 578 579 if (name == NULL) 580 return; 581 for (j = KT_RSA1; j <= KT_ED25519; j *= 2) { 582 if (get_keytypes & j) { 583 while (ncon >= MAXCON) 584 conloop(); 585 conalloc(name, *host ? host : name, j); 586 } 587 } 588 } 589 590 void 591 fatal(const char *fmt,...) 592 { 593 va_list args; 594 595 va_start(args, fmt); 596 do_log(SYSLOG_LEVEL_FATAL, fmt, args); 597 va_end(args); 598 if (nonfatal_fatal) 599 longjmp(kexjmp, -1); 600 else 601 exit(255); 602 } 603 604 static void 605 usage(void) 606 { 607 fprintf(stderr, 608 "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n" 609 "\t\t [host | addrlist namelist] ...\n", 610 __progname); 611 exit(1); 612 } 613 614 int 615 main(int argc, char **argv) 616 { 617 int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO; 618 int opt, fopt_count = 0, j; 619 char *tname, *cp, line[NI_MAXHOST]; 620 FILE *fp; 621 u_long linenum; 622 623 extern int optind; 624 extern char *optarg; 625 626 __progname = ssh_get_progname(argv[0]); 627 seed_rng(); 628 TAILQ_INIT(&tq); 629 630 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 631 sanitise_stdfd(); 632 633 if (argc <= 1) 634 usage(); 635 636 while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) { 637 switch (opt) { 638 case 'H': 639 hash_hosts = 1; 640 break; 641 case 'p': 642 ssh_port = a2port(optarg); 643 if (ssh_port <= 0) { 644 fprintf(stderr, "Bad port '%s'\n", optarg); 645 exit(1); 646 } 647 break; 648 case 'T': 649 timeout = convtime(optarg); 650 if (timeout == -1 || timeout == 0) { 651 fprintf(stderr, "Bad timeout '%s'\n", optarg); 652 usage(); 653 } 654 break; 655 case 'v': 656 if (!debug_flag) { 657 debug_flag = 1; 658 log_level = SYSLOG_LEVEL_DEBUG1; 659 } 660 else if (log_level < SYSLOG_LEVEL_DEBUG3) 661 log_level++; 662 else 663 fatal("Too high debugging level."); 664 break; 665 case 'f': 666 if (strcmp(optarg, "-") == 0) 667 optarg = NULL; 668 argv[fopt_count++] = optarg; 669 break; 670 case 't': 671 get_keytypes = 0; 672 tname = strtok(optarg, ","); 673 while (tname) { 674 int type = key_type_from_name(tname); 675 switch (type) { 676 case KEY_RSA1: 677 get_keytypes |= KT_RSA1; 678 break; 679 case KEY_DSA: 680 get_keytypes |= KT_DSA; 681 break; 682 case KEY_ECDSA: 683 get_keytypes |= KT_ECDSA; 684 break; 685 case KEY_RSA: 686 get_keytypes |= KT_RSA; 687 break; 688 case KEY_ED25519: 689 get_keytypes |= KT_ED25519; 690 break; 691 case KEY_UNSPEC: 692 fatal("unknown key type %s", tname); 693 } 694 tname = strtok(NULL, ","); 695 } 696 break; 697 case '4': 698 IPv4or6 = AF_INET; 699 break; 700 case '6': 701 IPv4or6 = AF_INET6; 702 break; 703 case '?': 704 default: 705 usage(); 706 } 707 } 708 if (optind == argc && !fopt_count) 709 usage(); 710 711 log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1); 712 713 maxfd = fdlim_get(1); 714 if (maxfd < 0) 715 fatal("%s: fdlim_get: bad value", __progname); 716 if (maxfd > MAXMAXFD) 717 maxfd = MAXMAXFD; 718 if (MAXCON <= 0) 719 fatal("%s: not enough file descriptors", __progname); 720 if (maxfd > fdlim_get(0)) 721 fdlim_set(maxfd); 722 fdcon = xcalloc(maxfd, sizeof(con)); 723 724 read_wait_nfdset = howmany(maxfd, NFDBITS); 725 read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask)); 726 727 for (j = 0; j < fopt_count; j++) { 728 if (argv[j] == NULL) 729 fp = stdin; 730 else if ((fp = fopen(argv[j], "r")) == NULL) 731 fatal("%s: %s: %s", __progname, argv[j], 732 strerror(errno)); 733 linenum = 0; 734 735 while (read_keyfile_line(fp, 736 argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line), 737 &linenum) != -1) { 738 /* Chomp off trailing whitespace and comments */ 739 if ((cp = strchr(line, '#')) == NULL) 740 cp = line + strlen(line) - 1; 741 while (cp >= line) { 742 if (*cp == ' ' || *cp == '\t' || 743 *cp == '\n' || *cp == '#') 744 *cp-- = '\0'; 745 else 746 break; 747 } 748 749 /* Skip empty lines */ 750 if (*line == '\0') 751 continue; 752 753 do_host(line); 754 } 755 756 if (ferror(fp)) 757 fatal("%s: %s: %s", __progname, argv[j], 758 strerror(errno)); 759 760 fclose(fp); 761 } 762 763 while (optind < argc) 764 do_host(argv[optind++]); 765 766 while (ncon > 0) 767 conloop(); 768 769 return (0); 770 } 771