ssh-keyscan.c

   1 /* $OpenBSD: ssh-keyscan.c,v 1.69 2006/07/22 20:48:23 stevesk 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
  15 #include <openssl/bn.h>
  16
  17 #include <netdb.h>
  18 #include <errno.h>
  19 #include <stdarg.h>
  20 #include <setjmp.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23
  24 #include "xmalloc.h"
  25 #include "ssh.h"
  26 #include "ssh1.h"
  27 #include "key.h"
  28 #include "kex.h"
  29 #include "compat.h"
  30 #include "myproposal.h"
  31 #include "packet.h"
  32 #include "dispatch.h"
  33 #include "buffer.h"
  34 #include "bufaux.h"
  35 #include "log.h"
  36 #include "atomicio.h"
  37 #include "misc.h"
  38 #include "hostfile.h"
  39
  40 /* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
  41    Default value is AF_UNSPEC means both IPv4 and IPv6. */
  42 int IPv4or6 = AF_UNSPEC;
  43
  44 int ssh_port = SSH_DEFAULT_PORT;
  45
  46 #define KT_RSA1 1
  47 #define KT_DSA  2
  48 #define KT_RSA  4
  49
  50 int get_keytypes = KT_RSA1;     /* Get only RSA1 keys by default */
  51
  52 int hash_hosts = 0;             /* Hash hostname on output */
  53
  54 #define MAXMAXFD 256
  55
  56 /* The number of seconds after which to give up on a TCP connection */
  57 int timeout = 5;
  58
  59 int maxfd;
  60 #define MAXCON (maxfd - 10)
  61
  62 extern char *__progname;
  63 fd_set *read_wait;
  64 size_t read_wait_nfdset;
  65 int ncon;
  66 int nonfatal_fatal = 0;
  67 jmp_buf kexjmp;
  68 Key *kexjmp_key;
  69
  70 /*
  71  * Keep a connection structure for each file descriptor.  The state
  72  * associated with file descriptor n is held in fdcon[n].
  73  */
  74 typedef struct Connection {
  75         u_char c_status;        /* State of connection on this file desc. */
  76 #define CS_UNUSED 0             /* File descriptor unused */
  77 #define CS_CON 1                /* Waiting to connect/read greeting */
  78 #define CS_SIZE 2               /* Waiting to read initial packet size */
  79 #define CS_KEYS 3               /* Waiting to read public key packet */
  80         int c_fd;               /* Quick lookup: c->c_fd == c - fdcon */
  81         int c_plen;             /* Packet length field for ssh packet */
  82         int c_len;              /* Total bytes which must be read. */
  83         int c_off;              /* Length of data read so far. */
  84         int c_keytype;          /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
  85         char *c_namebase;       /* Address to free for c_name and c_namelist */
  86         char *c_name;           /* Hostname of connection for errors */
  87         char *c_namelist;       /* Pointer to other possible addresses */
  88         char *c_output_name;    /* Hostname of connection for output */
  89         char *c_data;           /* Data read from this fd */
  90         Kex *c_kex;             /* The key-exchange struct for ssh2 */
  91         struct timeval c_tv;    /* Time at which connection gets aborted */
  92         TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
  93 } con;
  94
  95 TAILQ_HEAD(conlist, Connection) tq;     /* Timeout Queue */
  96 con *fdcon;
  97
  98 /*
  99  *  This is just a wrapper around fgets() to make it usable.
 100  */
 101
 102 /* Stress-test.  Increase this later. */
 103 #define LINEBUF_SIZE 16
 104
 105 typedef struct {
 106         char *buf;
 107         u_int size;
 108         int lineno;
 109         const char *filename;
 110         FILE *stream;
 111         void (*errfun) (const char *,...);
 112 } Linebuf;
 113
 114 static Linebuf *
 115 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
 116 {
 117         Linebuf *lb;
 118
 119         if (!(lb = malloc(sizeof(*lb)))) {
 120                 if (errfun)
 121                         (*errfun) ("linebuf (%s): malloc failed\n",
 122                             filename ? filename : "(stdin)");
 123                 return (NULL);
 124         }
 125         if (filename) {
 126                 lb->filename = filename;
 127                 if (!(lb->stream = fopen(filename, "r"))) {
 128                         xfree(lb);
 129                         if (errfun)
 130                                 (*errfun) ("%s: %s\n", filename, strerror(errno));
 131                         return (NULL);
 132                 }
 133         } else {
 134                 lb->filename = "(stdin)";
 135                 lb->stream = stdin;
 136         }
 137
 138         if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
 139                 if (errfun)
 140                         (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
 141                 xfree(lb);
 142                 return (NULL);
 143         }
 144         lb->errfun = errfun;
 145         lb->lineno = 0;
 146         return (lb);
 147 }
 148
 149 static void
 150 Linebuf_free(Linebuf * lb)
 151 {
 152         fclose(lb->stream);
 153         xfree(lb->buf);
 154         xfree(lb);
 155 }
 156
 157 #if 0
 158 static void
 159 Linebuf_restart(Linebuf * lb)
 160 {
 161         clearerr(lb->stream);
 162         rewind(lb->stream);
 163         lb->lineno = 0;
 164 }
 165
 166 static int
 167 Linebuf_lineno(Linebuf * lb)
 168 {
 169         return (lb->lineno);
 170 }
 171 #endif
 172
 173 static char *
 174 Linebuf_getline(Linebuf * lb)
 175 {
 176         size_t n = 0;
 177         void *p;
 178
 179         lb->lineno++;
 180         for (;;) {
 181                 /* Read a line */
 182                 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
 183                         if (ferror(lb->stream) && lb->errfun)
 184                                 (*lb->errfun)("%s: %s\n", lb->filename,
 185                                     strerror(errno));
 186                         return (NULL);
 187                 }
 188                 n = strlen(lb->buf);
 189
 190                 /* Return it or an error if it fits */
 191                 if (n > 0 && lb->buf[n - 1] == '\n') {
 192                         lb->buf[n - 1] = '\0';
 193                         return (lb->buf);
 194                 }
 195                 if (n != lb->size - 1) {
 196                         if (lb->errfun)
 197                                 (*lb->errfun)("%s: skipping incomplete last line\n",
 198                                     lb->filename);
 199                         return (NULL);
 200                 }
 201                 /* Double the buffer if we need more space */
 202                 lb->size *= 2;
 203                 if ((p = realloc(lb->buf, lb->size)) == NULL) {
 204                         lb->size /= 2;
 205                         if (lb->errfun)
 206                                 (*lb->errfun)("linebuf (%s): realloc failed\n",
 207                                     lb->filename);
 208                         return (NULL);
 209                 }
 210                 lb->buf = p;
 211         }
 212 }
 213
 214 static int
 215 fdlim_get(int hard)
 216 {
 217 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
 218         struct rlimit rlfd;
 219
 220         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 221                 return (-1);
 222         if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
 223                 return SSH_SYSFDMAX;
 224         else
 225                 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
 226 #else
 227         return SSH_SYSFDMAX;
 228 #endif
 229 }
 230
 231 static int
 232 fdlim_set(int lim)
 233 {
 234 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 235         struct rlimit rlfd;
 236 #endif
 237
 238         if (lim <= 0)
 239                 return (-1);
 240 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 241         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 242                 return (-1);
 243         rlfd.rlim_cur = lim;
 244         if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 245                 return (-1);
 246 #elif defined (HAVE_SETDTABLESIZE)
 247         setdtablesize(lim);
 248 #endif
 249         return (0);
 250 }
 251
 252 /*
 253  * This is an strsep function that returns a null field for adjacent
 254  * separators.  This is the same as the 4.4BSD strsep, but different from the
 255  * one in the GNU libc.
 256  */
 257 static char *
 258 xstrsep(char **str, const char *delim)
 259 {
 260         char *s, *e;
 261
 262         if (!**str)
 263                 return (NULL);
 264
 265         s = *str;
 266         e = s + strcspn(s, delim);
 267
 268         if (*e != '\0')
 269                 *e++ = '\0';
 270         *str = e;
 271
 272         return (s);
 273 }
 274
 275 /*
 276  * Get the next non-null token (like GNU strsep).  Strsep() will return a
 277  * null token for two adjacent separators, so we may have to loop.
 278  */
 279 static char *
 280 strnnsep(char **stringp, char *delim)
 281 {
 282         char *tok;
 283
 284         do {
 285                 tok = xstrsep(stringp, delim);
 286         } while (tok && *tok == '\0');
 287         return (tok);
 288 }
 289
 290 static Key *
 291 keygrab_ssh1(con *c)
 292 {
 293         static Key *rsa;
 294         static Buffer msg;
 295
 296         if (rsa == NULL) {
 297                 buffer_init(&msg);
 298                 rsa = key_new(KEY_RSA1);
 299         }
 300         buffer_append(&msg, c->c_data, c->c_plen);
 301         buffer_consume(&msg, 8 - (c->c_plen & 7));      /* padding */
 302         if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
 303                 error("%s: invalid packet type", c->c_name);
 304                 buffer_clear(&msg);
 305                 return NULL;
 306         }
 307         buffer_consume(&msg, 8);                /* cookie */
 308
 309         /* server key */
 310         (void) buffer_get_int(&msg);
 311         buffer_get_bignum(&msg, rsa->rsa->e);
 312         buffer_get_bignum(&msg, rsa->rsa->n);
 313
 314         /* host key */
 315         (void) buffer_get_int(&msg);
 316         buffer_get_bignum(&msg, rsa->rsa->e);
 317         buffer_get_bignum(&msg, rsa->rsa->n);
 318
 319         buffer_clear(&msg);
 320
 321         return (rsa);
 322 }
 323
 324 static int
 325 hostjump(Key *hostkey)
 326 {
 327         kexjmp_key = hostkey;
 328         longjmp(kexjmp, 1);
 329 }
 330
 331 static int
 332 ssh2_capable(int remote_major, int remote_minor)
 333 {
 334         switch (remote_major) {
 335         case 1:
 336                 if (remote_minor == 99)
 337                         return 1;
 338                 break;
 339         case 2:
 340                 return 1;
 341         default:
 342                 break;
 343         }
 344         return 0;
 345 }
 346
 347 static Key *
 348 keygrab_ssh2(con *c)
 349 {
 350         int j;
 351
 352         packet_set_connection(c->c_fd, c->c_fd);
 353         enable_compat20();
 354         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
 355             "ssh-dss": "ssh-rsa";
 356         c->c_kex = kex_setup(myproposal);
 357         c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
 358         c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
 359         c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
 360         c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
 361         c->c_kex->verify_host_key = hostjump;
 362
 363         if (!(j = setjmp(kexjmp))) {
 364                 nonfatal_fatal = 1;
 365                 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
 366                 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
 367                 exit(1);
 368         }
 369         nonfatal_fatal = 0;
 370         xfree(c->c_kex);
 371         c->c_kex = NULL;
 372         packet_close();
 373
 374         return j < 0? NULL : kexjmp_key;
 375 }
 376
 377 static void
 378 keyprint(con *c, Key *key)
 379 {
 380         char *host = c->c_output_name ? c->c_output_name : c->c_name;
 381
 382         if (!key)
 383                 return;
 384         if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
 385                 fatal("host_hash failed");
 386
 387         fprintf(stdout, "%s ", host);
 388         key_write(key, stdout);
 389         fputs("\n", stdout);
 390 }
 391
 392 static int
 393 tcpconnect(char *host)
 394 {
 395         struct addrinfo hints, *ai, *aitop;
 396         char strport[NI_MAXSERV];
 397         int gaierr, s = -1;
 398
 399         snprintf(strport, sizeof strport, "%d", ssh_port);
 400         memset(&hints, 0, sizeof(hints));
 401         hints.ai_family = IPv4or6;
 402         hints.ai_socktype = SOCK_STREAM;
 403         if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
 404                 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
 405         for (ai = aitop; ai; ai = ai->ai_next) {
 406                 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 407                 if (s < 0) {
 408                         error("socket: %s", strerror(errno));
 409                         continue;
 410                 }
 411                 if (set_nonblock(s) == -1)
 412                         fatal("%s: set_nonblock(%d)", __func__, s);
 413                 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
 414                     errno != EINPROGRESS)
 415                         error("connect (`%s'): %s", host, strerror(errno));
 416                 else
 417                         break;
 418                 close(s);
 419                 s = -1;
 420         }
 421         freeaddrinfo(aitop);
 422         return s;
 423 }
 424
 425 static int
 426 conalloc(char *iname, char *oname, int keytype)
 427 {
 428         char *namebase, *name, *namelist;
 429         int s;
 430
 431         namebase = namelist = xstrdup(iname);
 432
 433         do {
 434                 name = xstrsep(&namelist, ",");
 435                 if (!name) {
 436                         xfree(namebase);
 437                         return (-1);
 438                 }
 439         } while ((s = tcpconnect(name)) < 0);
 440
 441         if (s >= maxfd)
 442                 fatal("conalloc: fdno %d too high", s);
 443         if (fdcon[s].c_status)
 444                 fatal("conalloc: attempt to reuse fdno %d", s);
 445
 446         fdcon[s].c_fd = s;
 447         fdcon[s].c_status = CS_CON;
 448         fdcon[s].c_namebase = namebase;
 449         fdcon[s].c_name = name;
 450         fdcon[s].c_namelist = namelist;
 451         fdcon[s].c_output_name = xstrdup(oname);
 452         fdcon[s].c_data = (char *) &fdcon[s].c_plen;
 453         fdcon[s].c_len = 4;
 454         fdcon[s].c_off = 0;
 455         fdcon[s].c_keytype = keytype;
 456         gettimeofday(&fdcon[s].c_tv, NULL);
 457         fdcon[s].c_tv.tv_sec += timeout;
 458         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 459         FD_SET(s, read_wait);
 460         ncon++;
 461         return (s);
 462 }
 463
 464 static void
 465 confree(int s)
 466 {
 467         if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
 468                 fatal("confree: attempt to free bad fdno %d", s);
 469         close(s);
 470         xfree(fdcon[s].c_namebase);
 471         xfree(fdcon[s].c_output_name);
 472         if (fdcon[s].c_status == CS_KEYS)
 473                 xfree(fdcon[s].c_data);
 474         fdcon[s].c_status = CS_UNUSED;
 475         fdcon[s].c_keytype = 0;
 476         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 477         FD_CLR(s, read_wait);
 478         ncon--;
 479 }
 480
 481 static void
 482 contouch(int s)
 483 {
 484         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 485         gettimeofday(&fdcon[s].c_tv, NULL);
 486         fdcon[s].c_tv.tv_sec += timeout;
 487         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 488 }
 489
 490 static int
 491 conrecycle(int s)
 492 {
 493         con *c = &fdcon[s];
 494         int ret;
 495
 496         ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
 497         confree(s);
 498         return (ret);
 499 }
 500
 501 static void
 502 congreet(int s)
 503 {
 504         int n = 0, remote_major = 0, remote_minor = 0;
 505         char buf[256], *cp;
 506         char remote_version[sizeof buf];
 507         size_t bufsiz;
 508         con *c = &fdcon[s];
 509
 510         for (;;) {
 511                 memset(buf, '\0', sizeof(buf));
 512                 bufsiz = sizeof(buf);
 513                 cp = buf;
 514                 while (bufsiz-- &&
 515                     (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
 516                         if (*cp == '\r')
 517                                 *cp = '\n';
 518                         cp++;
 519                 }
 520                 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
 521                         break;
 522         }
 523         if (n == 0) {
 524                 switch (errno) {
 525                 case EPIPE:
 526                         error("%s: Connection closed by remote host", c->c_name);
 527                         break;
 528                 case ECONNREFUSED:
 529                         break;
 530                 default:
 531                         error("read (%s): %s", c->c_name, strerror(errno));
 532                         break;
 533                 }
 534                 conrecycle(s);
 535                 return;
 536         }
 537         if (*cp != '\n' && *cp != '\r') {
 538                 error("%s: bad greeting", c->c_name);
 539                 confree(s);
 540                 return;
 541         }
 542         *cp = '\0';
 543         if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
 544             &remote_major, &remote_minor, remote_version) == 3)
 545                 compat_datafellows(remote_version);
 546         else
 547                 datafellows = 0;
 548         if (c->c_keytype != KT_RSA1) {
 549                 if (!ssh2_capable(remote_major, remote_minor)) {
 550                         debug("%s doesn't support ssh2", c->c_name);
 551                         confree(s);
 552                         return;
 553                 }
 554         } else if (remote_major != 1) {
 555                 debug("%s doesn't support ssh1", c->c_name);
 556                 confree(s);
 557                 return;
 558         }
 559         fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
 560         n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
 561             c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
 562             c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
 563         if (n < 0 || (size_t)n >= sizeof(buf)) {
 564                 error("snprintf: buffer too small");
 565                 confree(s);
 566                 return;
 567         }
 568         if (atomicio(vwrite, s, buf, n) != (size_t)n) {
 569                 error("write (%s): %s", c->c_name, strerror(errno));
 570                 confree(s);
 571                 return;
 572         }
 573         if (c->c_keytype != KT_RSA1) {
 574                 keyprint(c, keygrab_ssh2(c));
 575                 confree(s);
 576                 return;
 577         }
 578         c->c_status = CS_SIZE;
 579         contouch(s);
 580 }
 581
 582 static void
 583 conread(int s)
 584 {
 585         con *c = &fdcon[s];
 586         size_t n;
 587
 588         if (c->c_status == CS_CON) {
 589                 congreet(s);
 590                 return;
 591         }
 592         n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
 593         if (n == 0) {
 594                 error("read (%s): %s", c->c_name, strerror(errno));
 595                 confree(s);
 596                 return;
 597         }
 598         c->c_off += n;
 599
 600         if (c->c_off == c->c_len)
 601                 switch (c->c_status) {
 602                 case CS_SIZE:
 603                         c->c_plen = htonl(c->c_plen);
 604                         c->c_len = c->c_plen + 8 - (c->c_plen & 7);
 605                         c->c_off = 0;
 606                         c->c_data = xmalloc(c->c_len);
 607                         c->c_status = CS_KEYS;
 608                         break;
 609                 case CS_KEYS:
 610                         keyprint(c, keygrab_ssh1(c));
 611                         confree(s);
 612                         return;
 613                 default:
 614                         fatal("conread: invalid status %d", c->c_status);
 615                         break;
 616                 }
 617
 618         contouch(s);
 619 }
 620
 621 static void
 622 conloop(void)
 623 {
 624         struct timeval seltime, now;
 625         fd_set *r, *e;
 626         con *c;
 627         int i;
 628
 629         gettimeofday(&now, NULL);
 630         c = TAILQ_FIRST(&tq);
 631
 632         if (c && (c->c_tv.tv_sec > now.tv_sec ||
 633             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
 634                 seltime = c->c_tv;
 635                 seltime.tv_sec -= now.tv_sec;
 636                 seltime.tv_usec -= now.tv_usec;
 637                 if (seltime.tv_usec < 0) {
 638                         seltime.tv_usec += 1000000;
 639                         seltime.tv_sec--;
 640                 }
 641         } else
 642                 seltime.tv_sec = seltime.tv_usec = 0;
 643
 644         r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 645         e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 646         memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
 647         memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
 648
 649         while (select(maxfd, r, NULL, e, &seltime) == -1 &&
 650             (errno == EAGAIN || errno == EINTR))
 651                 ;
 652
 653         for (i = 0; i < maxfd; i++) {
 654                 if (FD_ISSET(i, e)) {
 655                         error("%s: exception!", fdcon[i].c_name);
 656                         confree(i);
 657                 } else if (FD_ISSET(i, r))
 658                         conread(i);
 659         }
 660         xfree(r);
 661         xfree(e);
 662
 663         c = TAILQ_FIRST(&tq);
 664         while (c && (c->c_tv.tv_sec < now.tv_sec ||
 665             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
 666                 int s = c->c_fd;
 667
 668                 c = TAILQ_NEXT(c, c_link);
 669                 conrecycle(s);
 670         }
 671 }
 672
 673 static void
 674 do_host(char *host)
 675 {
 676         char *name = strnnsep(&host, " \t\n");
 677         int j;
 678
 679         if (name == NULL)
 680                 return;
 681         for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
 682                 if (get_keytypes & j) {
 683                         while (ncon >= MAXCON)
 684                                 conloop();
 685                         conalloc(name, *host ? host : name, j);
 686                 }
 687         }
 688 }
 689
 690 void
 691 fatal(const char *fmt,...)
 692 {
 693         va_list args;
 694
 695         va_start(args, fmt);
 696         do_log(SYSLOG_LEVEL_FATAL, fmt, args);
 697         va_end(args);
 698         if (nonfatal_fatal)
 699                 longjmp(kexjmp, -1);
 700         else
 701                 exit(255);
 702 }
 703
 704 static void
 705 usage(void)
 706 {
 707         fprintf(stderr, "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
 708             "\t\t   [host | addrlist namelist] [...]\n",
 709             __progname);
 710         exit(1);
 711 }
 712
 713 int
 714 main(int argc, char **argv)
 715 {
 716         int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
 717         int opt, fopt_count = 0;
 718         char *tname;
 719
 720         extern int optind;
 721         extern char *optarg;
 722
 723         __progname = ssh_get_progname(argv[0]);
 724         init_rng();
 725         seed_rng();
 726         TAILQ_INIT(&tq);
 727
 728         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 729         sanitise_stdfd();
 730
 731         if (argc <= 1)
 732                 usage();
 733
 734         while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
 735                 switch (opt) {
 736                 case 'H':
 737                         hash_hosts = 1;
 738                         break;
 739                 case 'p':
 740                         ssh_port = a2port(optarg);
 741                         if (ssh_port == 0) {
 742                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 743                                 exit(1);
 744                         }
 745                         break;
 746                 case 'T':
 747                         timeout = convtime(optarg);
 748                         if (timeout == -1 || timeout == 0) {
 749                                 fprintf(stderr, "Bad timeout '%s'\n", optarg);
 750                                 usage();
 751                         }
 752                         break;
 753                 case 'v':
 754                         if (!debug_flag) {
 755                                 debug_flag = 1;
 756                                 log_level = SYSLOG_LEVEL_DEBUG1;
 757                         }
 758                         else if (log_level < SYSLOG_LEVEL_DEBUG3)
 759                                 log_level++;
 760                         else
 761                                 fatal("Too high debugging level.");
 762                         break;
 763                 case 'f':
 764                         if (strcmp(optarg, "-") == 0)
 765                                 optarg = NULL;
 766                         argv[fopt_count++] = optarg;
 767                         break;
 768                 case 't':
 769                         get_keytypes = 0;
 770                         tname = strtok(optarg, ",");
 771                         while (tname) {
 772                                 int type = key_type_from_name(tname);
 773                                 switch (type) {
 774                                 case KEY_RSA1:
 775                                         get_keytypes |= KT_RSA1;
 776                                         break;
 777                                 case KEY_DSA:
 778                                         get_keytypes |= KT_DSA;
 779                                         break;
 780                                 case KEY_RSA:
 781                                         get_keytypes |= KT_RSA;
 782                                         break;
 783                                 case KEY_UNSPEC:
 784                                         fatal("unknown key type %s", tname);
 785                                 }
 786                                 tname = strtok(NULL, ",");
 787                         }
 788                         break;
 789                 case '4':
 790                         IPv4or6 = AF_INET;
 791                         break;
 792                 case '6':
 793                         IPv4or6 = AF_INET6;
 794                         break;
 795                 case '?':
 796                 default:
 797                         usage();
 798                 }
 799         }
 800         if (optind == argc && !fopt_count)
 801                 usage();
 802
 803         log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
 804
 805         maxfd = fdlim_get(1);
 806         if (maxfd < 0)
 807                 fatal("%s: fdlim_get: bad value", __progname);
 808         if (maxfd > MAXMAXFD)
 809                 maxfd = MAXMAXFD;
 810         if (MAXCON <= 0)
 811                 fatal("%s: not enough file descriptors", __progname);
 812         if (maxfd > fdlim_get(0))
 813                 fdlim_set(maxfd);
 814         fdcon = xcalloc(maxfd, sizeof(con));
 815
 816         read_wait_nfdset = howmany(maxfd, NFDBITS);
 817         read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 818
 819         if (fopt_count) {
 820                 Linebuf *lb;
 821                 char *line;
 822                 int j;
 823
 824                 for (j = 0; j < fopt_count; j++) {
 825                         lb = Linebuf_alloc(argv[j], error);
 826                         if (!lb)
 827                                 continue;
 828                         while ((line = Linebuf_getline(lb)) != NULL)
 829                                 do_host(line);
 830                         Linebuf_free(lb);
 831                 }
 832         }
 833
 834         while (optind < argc)
 835                 do_host(argv[optind++]);
 836
 837         while (ncon > 0)
 838                 conloop();
 839
 840         return (0);
 841 }