ssh-keyscan.c

   1 /* $OpenBSD: ssh-keyscan.c,v 1.82 2010/06/22 04:54:30 djm 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
  59 int get_keytypes = KT_RSA;      /* Get only RSA keys by default */
  60
  61 int hash_hosts = 0;             /* Hash hostname on output */
  62
  63 #define MAXMAXFD 256
  64
  65 /* The number of seconds after which to give up on a TCP connection */
  66 int timeout = 5;
  67
  68 int maxfd;
  69 #define MAXCON (maxfd - 10)
  70
  71 extern char *__progname;
  72 fd_set *read_wait;
  73 size_t read_wait_nfdset;
  74 int ncon;
  75 int nonfatal_fatal = 0;
  76 jmp_buf kexjmp;
  77 Key *kexjmp_key;
  78
  79 /*
  80  * Keep a connection structure for each file descriptor.  The state
  81  * associated with file descriptor n is held in fdcon[n].
  82  */
  83 typedef struct Connection {
  84         u_char c_status;        /* State of connection on this file desc. */
  85 #define CS_UNUSED 0             /* File descriptor unused */
  86 #define CS_CON 1                /* Waiting to connect/read greeting */
  87 #define CS_SIZE 2               /* Waiting to read initial packet size */
  88 #define CS_KEYS 3               /* Waiting to read public key packet */
  89         int c_fd;               /* Quick lookup: c->c_fd == c - fdcon */
  90         int c_plen;             /* Packet length field for ssh packet */
  91         int c_len;              /* Total bytes which must be read. */
  92         int c_off;              /* Length of data read so far. */
  93         int c_keytype;          /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
  94         char *c_namebase;       /* Address to free for c_name and c_namelist */
  95         char *c_name;           /* Hostname of connection for errors */
  96         char *c_namelist;       /* Pointer to other possible addresses */
  97         char *c_output_name;    /* Hostname of connection for output */
  98         char *c_data;           /* Data read from this fd */
  99         Kex *c_kex;             /* The key-exchange struct for ssh2 */
 100         struct timeval c_tv;    /* Time at which connection gets aborted */
 101         TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
 102 } con;
 103
 104 TAILQ_HEAD(conlist, Connection) tq;     /* Timeout Queue */
 105 con *fdcon;
 106
 107 static int
 108 fdlim_get(int hard)
 109 {
 110 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
 111         struct rlimit rlfd;
 112
 113         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 114                 return (-1);
 115         if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
 116                 return SSH_SYSFDMAX;
 117         else
 118                 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
 119 #else
 120         return SSH_SYSFDMAX;
 121 #endif
 122 }
 123
 124 static int
 125 fdlim_set(int lim)
 126 {
 127 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 128         struct rlimit rlfd;
 129 #endif
 130
 131         if (lim <= 0)
 132                 return (-1);
 133 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 134         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 135                 return (-1);
 136         rlfd.rlim_cur = lim;
 137         if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 138                 return (-1);
 139 #elif defined (HAVE_SETDTABLESIZE)
 140         setdtablesize(lim);
 141 #endif
 142         return (0);
 143 }
 144
 145 /*
 146  * This is an strsep function that returns a null field for adjacent
 147  * separators.  This is the same as the 4.4BSD strsep, but different from the
 148  * one in the GNU libc.
 149  */
 150 static char *
 151 xstrsep(char **str, const char *delim)
 152 {
 153         char *s, *e;
 154
 155         if (!**str)
 156                 return (NULL);
 157
 158         s = *str;
 159         e = s + strcspn(s, delim);
 160
 161         if (*e != '\0')
 162                 *e++ = '\0';
 163         *str = e;
 164
 165         return (s);
 166 }
 167
 168 /*
 169  * Get the next non-null token (like GNU strsep).  Strsep() will return a
 170  * null token for two adjacent separators, so we may have to loop.
 171  */
 172 static char *
 173 strnnsep(char **stringp, char *delim)
 174 {
 175         char *tok;
 176
 177         do {
 178                 tok = xstrsep(stringp, delim);
 179         } while (tok && *tok == '\0');
 180         return (tok);
 181 }
 182
 183 static Key *
 184 keygrab_ssh1(con *c)
 185 {
 186         static Key *rsa;
 187         static Buffer msg;
 188
 189         if (rsa == NULL) {
 190                 buffer_init(&msg);
 191                 rsa = key_new(KEY_RSA1);
 192         }
 193         buffer_append(&msg, c->c_data, c->c_plen);
 194         buffer_consume(&msg, 8 - (c->c_plen & 7));      /* padding */
 195         if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
 196                 error("%s: invalid packet type", c->c_name);
 197                 buffer_clear(&msg);
 198                 return NULL;
 199         }
 200         buffer_consume(&msg, 8);                /* cookie */
 201
 202         /* server key */
 203         (void) buffer_get_int(&msg);
 204         buffer_get_bignum(&msg, rsa->rsa->e);
 205         buffer_get_bignum(&msg, rsa->rsa->n);
 206
 207         /* host key */
 208         (void) buffer_get_int(&msg);
 209         buffer_get_bignum(&msg, rsa->rsa->e);
 210         buffer_get_bignum(&msg, rsa->rsa->n);
 211
 212         buffer_clear(&msg);
 213
 214         return (rsa);
 215 }
 216
 217 static int
 218 hostjump(Key *hostkey)
 219 {
 220         kexjmp_key = hostkey;
 221         longjmp(kexjmp, 1);
 222 }
 223
 224 static int
 225 ssh2_capable(int remote_major, int remote_minor)
 226 {
 227         switch (remote_major) {
 228         case 1:
 229                 if (remote_minor == 99)
 230                         return 1;
 231                 break;
 232         case 2:
 233                 return 1;
 234         default:
 235                 break;
 236         }
 237         return 0;
 238 }
 239
 240 static Key *
 241 keygrab_ssh2(con *c)
 242 {
 243         int j;
 244
 245         packet_set_connection(c->c_fd, c->c_fd);
 246         enable_compat20();
 247         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
 248             "ssh-dss": "ssh-rsa";
 249         c->c_kex = kex_setup(myproposal);
 250         c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
 251         c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
 252         c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
 253         c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
 254         c->c_kex->verify_host_key = hostjump;
 255
 256         if (!(j = setjmp(kexjmp))) {
 257                 nonfatal_fatal = 1;
 258                 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
 259                 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
 260                 exit(1);
 261         }
 262         nonfatal_fatal = 0;
 263         xfree(c->c_kex);
 264         c->c_kex = NULL;
 265         packet_close();
 266
 267         return j < 0? NULL : kexjmp_key;
 268 }
 269
 270 static void
 271 keyprint(con *c, Key *key)
 272 {
 273         char *host = c->c_output_name ? c->c_output_name : c->c_name;
 274
 275         if (!key)
 276                 return;
 277         if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
 278                 fatal("host_hash failed");
 279
 280         fprintf(stdout, "%s ", host);
 281         key_write(key, stdout);
 282         fputs("\n", stdout);
 283 }
 284
 285 static int
 286 tcpconnect(char *host)
 287 {
 288         struct addrinfo hints, *ai, *aitop;
 289         char strport[NI_MAXSERV];
 290         int gaierr, s = -1;
 291
 292         snprintf(strport, sizeof strport, "%d", ssh_port);
 293         memset(&hints, 0, sizeof(hints));
 294         hints.ai_family = IPv4or6;
 295         hints.ai_socktype = SOCK_STREAM;
 296         if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
 297                 fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
 298         for (ai = aitop; ai; ai = ai->ai_next) {
 299                 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 300                 if (s < 0) {
 301                         error("socket: %s", strerror(errno));
 302                         continue;
 303                 }
 304                 if (set_nonblock(s) == -1)
 305                         fatal("%s: set_nonblock(%d)", __func__, s);
 306                 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
 307                     errno != EINPROGRESS)
 308                         error("connect (`%s'): %s", host, strerror(errno));
 309                 else
 310                         break;
 311                 close(s);
 312                 s = -1;
 313         }
 314         freeaddrinfo(aitop);
 315         return s;
 316 }
 317
 318 static int
 319 conalloc(char *iname, char *oname, int keytype)
 320 {
 321         char *namebase, *name, *namelist;
 322         int s;
 323
 324         namebase = namelist = xstrdup(iname);
 325
 326         do {
 327                 name = xstrsep(&namelist, ",");
 328                 if (!name) {
 329                         xfree(namebase);
 330                         return (-1);
 331                 }
 332         } while ((s = tcpconnect(name)) < 0);
 333
 334         if (s >= maxfd)
 335                 fatal("conalloc: fdno %d too high", s);
 336         if (fdcon[s].c_status)
 337                 fatal("conalloc: attempt to reuse fdno %d", s);
 338
 339         fdcon[s].c_fd = s;
 340         fdcon[s].c_status = CS_CON;
 341         fdcon[s].c_namebase = namebase;
 342         fdcon[s].c_name = name;
 343         fdcon[s].c_namelist = namelist;
 344         fdcon[s].c_output_name = xstrdup(oname);
 345         fdcon[s].c_data = (char *) &fdcon[s].c_plen;
 346         fdcon[s].c_len = 4;
 347         fdcon[s].c_off = 0;
 348         fdcon[s].c_keytype = keytype;
 349         gettimeofday(&fdcon[s].c_tv, NULL);
 350         fdcon[s].c_tv.tv_sec += timeout;
 351         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 352         FD_SET(s, read_wait);
 353         ncon++;
 354         return (s);
 355 }
 356
 357 static void
 358 confree(int s)
 359 {
 360         if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
 361                 fatal("confree: attempt to free bad fdno %d", s);
 362         close(s);
 363         xfree(fdcon[s].c_namebase);
 364         xfree(fdcon[s].c_output_name);
 365         if (fdcon[s].c_status == CS_KEYS)
 366                 xfree(fdcon[s].c_data);
 367         fdcon[s].c_status = CS_UNUSED;
 368         fdcon[s].c_keytype = 0;
 369         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 370         FD_CLR(s, read_wait);
 371         ncon--;
 372 }
 373
 374 static void
 375 contouch(int s)
 376 {
 377         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 378         gettimeofday(&fdcon[s].c_tv, NULL);
 379         fdcon[s].c_tv.tv_sec += timeout;
 380         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 381 }
 382
 383 static int
 384 conrecycle(int s)
 385 {
 386         con *c = &fdcon[s];
 387         int ret;
 388
 389         ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
 390         confree(s);
 391         return (ret);
 392 }
 393
 394 static void
 395 congreet(int s)
 396 {
 397         int n = 0, remote_major = 0, remote_minor = 0;
 398         char buf[256], *cp;
 399         char remote_version[sizeof buf];
 400         size_t bufsiz;
 401         con *c = &fdcon[s];
 402
 403         for (;;) {
 404                 memset(buf, '\0', sizeof(buf));
 405                 bufsiz = sizeof(buf);
 406                 cp = buf;
 407                 while (bufsiz-- &&
 408                     (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
 409                         if (*cp == '\r')
 410                                 *cp = '\n';
 411                         cp++;
 412                 }
 413                 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
 414                         break;
 415         }
 416         if (n == 0) {
 417                 switch (errno) {
 418                 case EPIPE:
 419                         error("%s: Connection closed by remote host", c->c_name);
 420                         break;
 421                 case ECONNREFUSED:
 422                         break;
 423                 default:
 424                         error("read (%s): %s", c->c_name, strerror(errno));
 425                         break;
 426                 }
 427                 conrecycle(s);
 428                 return;
 429         }
 430         if (*cp != '\n' && *cp != '\r') {
 431                 error("%s: bad greeting", c->c_name);
 432                 confree(s);
 433                 return;
 434         }
 435         *cp = '\0';
 436         if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
 437             &remote_major, &remote_minor, remote_version) == 3)
 438                 compat_datafellows(remote_version);
 439         else
 440                 datafellows = 0;
 441         if (c->c_keytype != KT_RSA1) {
 442                 if (!ssh2_capable(remote_major, remote_minor)) {
 443                         debug("%s doesn't support ssh2", c->c_name);
 444                         confree(s);
 445                         return;
 446                 }
 447         } else if (remote_major != 1) {
 448                 debug("%s doesn't support ssh1", c->c_name);
 449                 confree(s);
 450                 return;
 451         }
 452         fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
 453         n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
 454             c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
 455             c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
 456         if (n < 0 || (size_t)n >= sizeof(buf)) {
 457                 error("snprintf: buffer too small");
 458                 confree(s);
 459                 return;
 460         }
 461         if (atomicio(vwrite, s, buf, n) != (size_t)n) {
 462                 error("write (%s): %s", c->c_name, strerror(errno));
 463                 confree(s);
 464                 return;
 465         }
 466         if (c->c_keytype != KT_RSA1) {
 467                 keyprint(c, keygrab_ssh2(c));
 468                 confree(s);
 469                 return;
 470         }
 471         c->c_status = CS_SIZE;
 472         contouch(s);
 473 }
 474
 475 static void
 476 conread(int s)
 477 {
 478         con *c = &fdcon[s];
 479         size_t n;
 480
 481         if (c->c_status == CS_CON) {
 482                 congreet(s);
 483                 return;
 484         }
 485         n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
 486         if (n == 0) {
 487                 error("read (%s): %s", c->c_name, strerror(errno));
 488                 confree(s);
 489                 return;
 490         }
 491         c->c_off += n;
 492
 493         if (c->c_off == c->c_len)
 494                 switch (c->c_status) {
 495                 case CS_SIZE:
 496                         c->c_plen = htonl(c->c_plen);
 497                         c->c_len = c->c_plen + 8 - (c->c_plen & 7);
 498                         c->c_off = 0;
 499                         c->c_data = xmalloc(c->c_len);
 500                         c->c_status = CS_KEYS;
 501                         break;
 502                 case CS_KEYS:
 503                         keyprint(c, keygrab_ssh1(c));
 504                         confree(s);
 505                         return;
 506                 default:
 507                         fatal("conread: invalid status %d", c->c_status);
 508                         break;
 509                 }
 510
 511         contouch(s);
 512 }
 513
 514 static void
 515 conloop(void)
 516 {
 517         struct timeval seltime, now;
 518         fd_set *r, *e;
 519         con *c;
 520         int i;
 521
 522         gettimeofday(&now, NULL);
 523         c = TAILQ_FIRST(&tq);
 524
 525         if (c && (c->c_tv.tv_sec > now.tv_sec ||
 526             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
 527                 seltime = c->c_tv;
 528                 seltime.tv_sec -= now.tv_sec;
 529                 seltime.tv_usec -= now.tv_usec;
 530                 if (seltime.tv_usec < 0) {
 531                         seltime.tv_usec += 1000000;
 532                         seltime.tv_sec--;
 533                 }
 534         } else
 535                 seltime.tv_sec = seltime.tv_usec = 0;
 536
 537         r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 538         e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 539         memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
 540         memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
 541
 542         while (select(maxfd, r, NULL, e, &seltime) == -1 &&
 543             (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 544                 ;
 545
 546         for (i = 0; i < maxfd; i++) {
 547                 if (FD_ISSET(i, e)) {
 548                         error("%s: exception!", fdcon[i].c_name);
 549                         confree(i);
 550                 } else if (FD_ISSET(i, r))
 551                         conread(i);
 552         }
 553         xfree(r);
 554         xfree(e);
 555
 556         c = TAILQ_FIRST(&tq);
 557         while (c && (c->c_tv.tv_sec < now.tv_sec ||
 558             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
 559                 int s = c->c_fd;
 560
 561                 c = TAILQ_NEXT(c, c_link);
 562                 conrecycle(s);
 563         }
 564 }
 565
 566 static void
 567 do_host(char *host)
 568 {
 569         char *name = strnnsep(&host, " \t\n");
 570         int j;
 571
 572         if (name == NULL)
 573                 return;
 574         for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
 575                 if (get_keytypes & j) {
 576                         while (ncon >= MAXCON)
 577                                 conloop();
 578                         conalloc(name, *host ? host : name, j);
 579                 }
 580         }
 581 }
 582
 583 void
 584 fatal(const char *fmt,...)
 585 {
 586         va_list args;
 587
 588         va_start(args, fmt);
 589         do_log(SYSLOG_LEVEL_FATAL, fmt, args);
 590         va_end(args);
 591         if (nonfatal_fatal)
 592                 longjmp(kexjmp, -1);
 593         else
 594                 exit(255);
 595 }
 596
 597 static void
 598 usage(void)
 599 {
 600         fprintf(stderr,
 601             "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
 602             "\t\t   [host | addrlist namelist] ...\n",
 603             __progname);
 604         exit(1);
 605 }
 606
 607 int
 608 main(int argc, char **argv)
 609 {
 610         int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
 611         int opt, fopt_count = 0, j;
 612         char *tname, *cp, line[NI_MAXHOST];
 613         FILE *fp;
 614         u_long linenum;
 615
 616         extern int optind;
 617         extern char *optarg;
 618
 619         __progname = ssh_get_progname(argv[0]);
 620         init_rng();
 621         seed_rng();
 622         TAILQ_INIT(&tq);
 623
 624         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 625         sanitise_stdfd();
 626
 627         if (argc <= 1)
 628                 usage();
 629
 630         while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
 631                 switch (opt) {
 632                 case 'H':
 633                         hash_hosts = 1;
 634                         break;
 635                 case 'p':
 636                         ssh_port = a2port(optarg);
 637                         if (ssh_port <= 0) {
 638                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 639                                 exit(1);
 640                         }
 641                         break;
 642                 case 'T':
 643                         timeout = convtime(optarg);
 644                         if (timeout == -1 || timeout == 0) {
 645                                 fprintf(stderr, "Bad timeout '%s'\n", optarg);
 646                                 usage();
 647                         }
 648                         break;
 649                 case 'v':
 650                         if (!debug_flag) {
 651                                 debug_flag = 1;
 652                                 log_level = SYSLOG_LEVEL_DEBUG1;
 653                         }
 654                         else if (log_level < SYSLOG_LEVEL_DEBUG3)
 655                                 log_level++;
 656                         else
 657                                 fatal("Too high debugging level.");
 658                         break;
 659                 case 'f':
 660                         if (strcmp(optarg, "-") == 0)
 661                                 optarg = NULL;
 662                         argv[fopt_count++] = optarg;
 663                         break;
 664                 case 't':
 665                         get_keytypes = 0;
 666                         tname = strtok(optarg, ",");
 667                         while (tname) {
 668                                 int type = key_type_from_name(tname);
 669                                 switch (type) {
 670                                 case KEY_RSA1:
 671                                         get_keytypes |= KT_RSA1;
 672                                         break;
 673                                 case KEY_DSA:
 674                                         get_keytypes |= KT_DSA;
 675                                         break;
 676                                 case KEY_RSA:
 677                                         get_keytypes |= KT_RSA;
 678                                         break;
 679                                 case KEY_UNSPEC:
 680                                         fatal("unknown key type %s", tname);
 681                                 }
 682                                 tname = strtok(NULL, ",");
 683                         }
 684                         break;
 685                 case '4':
 686                         IPv4or6 = AF_INET;
 687                         break;
 688                 case '6':
 689                         IPv4or6 = AF_INET6;
 690                         break;
 691                 case '?':
 692                 default:
 693                         usage();
 694                 }
 695         }
 696         if (optind == argc && !fopt_count)
 697                 usage();
 698
 699         log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
 700
 701         maxfd = fdlim_get(1);
 702         if (maxfd < 0)
 703                 fatal("%s: fdlim_get: bad value", __progname);
 704         if (maxfd > MAXMAXFD)
 705                 maxfd = MAXMAXFD;
 706         if (MAXCON <= 0)
 707                 fatal("%s: not enough file descriptors", __progname);
 708         if (maxfd > fdlim_get(0))
 709                 fdlim_set(maxfd);
 710         fdcon = xcalloc(maxfd, sizeof(con));
 711
 712         read_wait_nfdset = howmany(maxfd, NFDBITS);
 713         read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 714
 715         for (j = 0; j < fopt_count; j++) {
 716                 if (argv[j] == NULL)
 717                         fp = stdin;
 718                 else if ((fp = fopen(argv[j], "r")) == NULL)
 719                         fatal("%s: %s: %s", __progname, argv[j],
 720                             strerror(errno));
 721                 linenum = 0;
 722
 723                 while (read_keyfile_line(fp,
 724                     argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
 725                     &linenum) != -1) {
 726                         /* Chomp off trailing whitespace and comments */
 727                         if ((cp = strchr(line, '#')) == NULL)
 728                                 cp = line + strlen(line) - 1;
 729                         while (cp >= line) {
 730                                 if (*cp == ' ' || *cp == '\t' ||
 731                                     *cp == '\n' || *cp == '#')
 732                                         *cp-- = '\0';
 733                                 else
 734                                         break;
 735                         }
 736
 737                         /* Skip empty lines */
 738                         if (*line == '\0')
 739                                 continue;
 740
 741                         do_host(line);
 742                 }
 743
 744                 if (ferror(fp))
 745                         fatal("%s: %s: %s", __progname, argv[j],
 746                             strerror(errno));
 747
 748                 fclose(fp);
 749         }
 750
 751         while (optind < argc)
 752                 do_host(argv[optind++]);
 753
 754         while (ncon > 0)
 755                 conloop();
 756
 757         return (0);
 758 }