ssh-keyscan.c

   1 /* $OpenBSD: ssh-keyscan.c,v 1.74 2006/10/06 02:29:19 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_RSA1;     /* Get only RSA1 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 /*
 108  *  This is just a wrapper around fgets() to make it usable.
 109  */
 110
 111 /* Stress-test.  Increase this later. */
 112 #define LINEBUF_SIZE 16
 113
 114 typedef struct {
 115         char *buf;
 116         u_int size;
 117         int lineno;
 118         const char *filename;
 119         FILE *stream;
 120         void (*errfun) (const char *,...);
 121 } Linebuf;
 122
 123 static Linebuf *
 124 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
 125 {
 126         Linebuf *lb;
 127
 128         if (!(lb = malloc(sizeof(*lb)))) {
 129                 if (errfun)
 130                         (*errfun) ("linebuf (%s): malloc failed\n",
 131                             filename ? filename : "(stdin)");
 132                 return (NULL);
 133         }
 134         if (filename) {
 135                 lb->filename = filename;
 136                 if (!(lb->stream = fopen(filename, "r"))) {
 137                         xfree(lb);
 138                         if (errfun)
 139                                 (*errfun) ("%s: %s\n", filename, strerror(errno));
 140                         return (NULL);
 141                 }
 142         } else {
 143                 lb->filename = "(stdin)";
 144                 lb->stream = stdin;
 145         }
 146
 147         if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
 148                 if (errfun)
 149                         (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
 150                 xfree(lb);
 151                 return (NULL);
 152         }
 153         lb->errfun = errfun;
 154         lb->lineno = 0;
 155         return (lb);
 156 }
 157
 158 static void
 159 Linebuf_free(Linebuf * lb)
 160 {
 161         fclose(lb->stream);
 162         xfree(lb->buf);
 163         xfree(lb);
 164 }
 165
 166 #if 0
 167 static void
 168 Linebuf_restart(Linebuf * lb)
 169 {
 170         clearerr(lb->stream);
 171         rewind(lb->stream);
 172         lb->lineno = 0;
 173 }
 174
 175 static int
 176 Linebuf_lineno(Linebuf * lb)
 177 {
 178         return (lb->lineno);
 179 }
 180 #endif
 181
 182 static char *
 183 Linebuf_getline(Linebuf * lb)
 184 {
 185         size_t n = 0;
 186         void *p;
 187
 188         lb->lineno++;
 189         for (;;) {
 190                 /* Read a line */
 191                 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
 192                         if (ferror(lb->stream) && lb->errfun)
 193                                 (*lb->errfun)("%s: %s\n", lb->filename,
 194                                     strerror(errno));
 195                         return (NULL);
 196                 }
 197                 n = strlen(lb->buf);
 198
 199                 /* Return it or an error if it fits */
 200                 if (n > 0 && lb->buf[n - 1] == '\n') {
 201                         lb->buf[n - 1] = '\0';
 202                         return (lb->buf);
 203                 }
 204                 if (n != lb->size - 1) {
 205                         if (lb->errfun)
 206                                 (*lb->errfun)("%s: skipping incomplete last line\n",
 207                                     lb->filename);
 208                         return (NULL);
 209                 }
 210                 /* Double the buffer if we need more space */
 211                 lb->size *= 2;
 212                 if ((p = realloc(lb->buf, lb->size)) == NULL) {
 213                         lb->size /= 2;
 214                         if (lb->errfun)
 215                                 (*lb->errfun)("linebuf (%s): realloc failed\n",
 216                                     lb->filename);
 217                         return (NULL);
 218                 }
 219                 lb->buf = p;
 220         }
 221 }
 222
 223 static int
 224 fdlim_get(int hard)
 225 {
 226 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
 227         struct rlimit rlfd;
 228
 229         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 230                 return (-1);
 231         if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
 232                 return SSH_SYSFDMAX;
 233         else
 234                 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
 235 #else
 236         return SSH_SYSFDMAX;
 237 #endif
 238 }
 239
 240 static int
 241 fdlim_set(int lim)
 242 {
 243 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 244         struct rlimit rlfd;
 245 #endif
 246
 247         if (lim <= 0)
 248                 return (-1);
 249 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 250         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 251                 return (-1);
 252         rlfd.rlim_cur = lim;
 253         if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 254                 return (-1);
 255 #elif defined (HAVE_SETDTABLESIZE)
 256         setdtablesize(lim);
 257 #endif
 258         return (0);
 259 }
 260
 261 /*
 262  * This is an strsep function that returns a null field for adjacent
 263  * separators.  This is the same as the 4.4BSD strsep, but different from the
 264  * one in the GNU libc.
 265  */
 266 static char *
 267 xstrsep(char **str, const char *delim)
 268 {
 269         char *s, *e;
 270
 271         if (!**str)
 272                 return (NULL);
 273
 274         s = *str;
 275         e = s + strcspn(s, delim);
 276
 277         if (*e != '\0')
 278                 *e++ = '\0';
 279         *str = e;
 280
 281         return (s);
 282 }
 283
 284 /*
 285  * Get the next non-null token (like GNU strsep).  Strsep() will return a
 286  * null token for two adjacent separators, so we may have to loop.
 287  */
 288 static char *
 289 strnnsep(char **stringp, char *delim)
 290 {
 291         char *tok;
 292
 293         do {
 294                 tok = xstrsep(stringp, delim);
 295         } while (tok && *tok == '\0');
 296         return (tok);
 297 }
 298
 299 static Key *
 300 keygrab_ssh1(con *c)
 301 {
 302         static Key *rsa;
 303         static Buffer msg;
 304
 305         if (rsa == NULL) {
 306                 buffer_init(&msg);
 307                 rsa = key_new(KEY_RSA1);
 308         }
 309         buffer_append(&msg, c->c_data, c->c_plen);
 310         buffer_consume(&msg, 8 - (c->c_plen & 7));      /* padding */
 311         if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
 312                 error("%s: invalid packet type", c->c_name);
 313                 buffer_clear(&msg);
 314                 return NULL;
 315         }
 316         buffer_consume(&msg, 8);                /* cookie */
 317
 318         /* server key */
 319         (void) buffer_get_int(&msg);
 320         buffer_get_bignum(&msg, rsa->rsa->e);
 321         buffer_get_bignum(&msg, rsa->rsa->n);
 322
 323         /* host key */
 324         (void) buffer_get_int(&msg);
 325         buffer_get_bignum(&msg, rsa->rsa->e);
 326         buffer_get_bignum(&msg, rsa->rsa->n);
 327
 328         buffer_clear(&msg);
 329
 330         return (rsa);
 331 }
 332
 333 static int
 334 hostjump(Key *hostkey)
 335 {
 336         kexjmp_key = hostkey;
 337         longjmp(kexjmp, 1);
 338 }
 339
 340 static int
 341 ssh2_capable(int remote_major, int remote_minor)
 342 {
 343         switch (remote_major) {
 344         case 1:
 345                 if (remote_minor == 99)
 346                         return 1;
 347                 break;
 348         case 2:
 349                 return 1;
 350         default:
 351                 break;
 352         }
 353         return 0;
 354 }
 355
 356 static Key *
 357 keygrab_ssh2(con *c)
 358 {
 359         int j;
 360
 361         packet_set_connection(c->c_fd, c->c_fd);
 362         enable_compat20();
 363         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
 364             "ssh-dss": "ssh-rsa";
 365         c->c_kex = kex_setup(myproposal);
 366         c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
 367         c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
 368         c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
 369         c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
 370         c->c_kex->verify_host_key = hostjump;
 371
 372         if (!(j = setjmp(kexjmp))) {
 373                 nonfatal_fatal = 1;
 374                 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
 375                 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
 376                 exit(1);
 377         }
 378         nonfatal_fatal = 0;
 379         xfree(c->c_kex);
 380         c->c_kex = NULL;
 381         packet_close();
 382
 383         return j < 0? NULL : kexjmp_key;
 384 }
 385
 386 static void
 387 keyprint(con *c, Key *key)
 388 {
 389         char *host = c->c_output_name ? c->c_output_name : c->c_name;
 390
 391         if (!key)
 392                 return;
 393         if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
 394                 fatal("host_hash failed");
 395
 396         fprintf(stdout, "%s ", host);
 397         key_write(key, stdout);
 398         fputs("\n", stdout);
 399 }
 400
 401 static int
 402 tcpconnect(char *host)
 403 {
 404         struct addrinfo hints, *ai, *aitop;
 405         char strport[NI_MAXSERV];
 406         int gaierr, s = -1;
 407
 408         snprintf(strport, sizeof strport, "%d", ssh_port);
 409         memset(&hints, 0, sizeof(hints));
 410         hints.ai_family = IPv4or6;
 411         hints.ai_socktype = SOCK_STREAM;
 412         if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
 413                 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
 414         for (ai = aitop; ai; ai = ai->ai_next) {
 415                 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 416                 if (s < 0) {
 417                         error("socket: %s", strerror(errno));
 418                         continue;
 419                 }
 420                 if (set_nonblock(s) == -1)
 421                         fatal("%s: set_nonblock(%d)", __func__, s);
 422                 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
 423                     errno != EINPROGRESS)
 424                         error("connect (`%s'): %s", host, strerror(errno));
 425                 else
 426                         break;
 427                 close(s);
 428                 s = -1;
 429         }
 430         freeaddrinfo(aitop);
 431         return s;
 432 }
 433
 434 static int
 435 conalloc(char *iname, char *oname, int keytype)
 436 {
 437         char *namebase, *name, *namelist;
 438         int s;
 439
 440         namebase = namelist = xstrdup(iname);
 441
 442         do {
 443                 name = xstrsep(&namelist, ",");
 444                 if (!name) {
 445                         xfree(namebase);
 446                         return (-1);
 447                 }
 448         } while ((s = tcpconnect(name)) < 0);
 449
 450         if (s >= maxfd)
 451                 fatal("conalloc: fdno %d too high", s);
 452         if (fdcon[s].c_status)
 453                 fatal("conalloc: attempt to reuse fdno %d", s);
 454
 455         fdcon[s].c_fd = s;
 456         fdcon[s].c_status = CS_CON;
 457         fdcon[s].c_namebase = namebase;
 458         fdcon[s].c_name = name;
 459         fdcon[s].c_namelist = namelist;
 460         fdcon[s].c_output_name = xstrdup(oname);
 461         fdcon[s].c_data = (char *) &fdcon[s].c_plen;
 462         fdcon[s].c_len = 4;
 463         fdcon[s].c_off = 0;
 464         fdcon[s].c_keytype = keytype;
 465         gettimeofday(&fdcon[s].c_tv, NULL);
 466         fdcon[s].c_tv.tv_sec += timeout;
 467         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 468         FD_SET(s, read_wait);
 469         ncon++;
 470         return (s);
 471 }
 472
 473 static void
 474 confree(int s)
 475 {
 476         if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
 477                 fatal("confree: attempt to free bad fdno %d", s);
 478         close(s);
 479         xfree(fdcon[s].c_namebase);
 480         xfree(fdcon[s].c_output_name);
 481         if (fdcon[s].c_status == CS_KEYS)
 482                 xfree(fdcon[s].c_data);
 483         fdcon[s].c_status = CS_UNUSED;
 484         fdcon[s].c_keytype = 0;
 485         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 486         FD_CLR(s, read_wait);
 487         ncon--;
 488 }
 489
 490 static void
 491 contouch(int s)
 492 {
 493         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 494         gettimeofday(&fdcon[s].c_tv, NULL);
 495         fdcon[s].c_tv.tv_sec += timeout;
 496         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 497 }
 498
 499 static int
 500 conrecycle(int s)
 501 {
 502         con *c = &fdcon[s];
 503         int ret;
 504
 505         ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
 506         confree(s);
 507         return (ret);
 508 }
 509
 510 static void
 511 congreet(int s)
 512 {
 513         int n = 0, remote_major = 0, remote_minor = 0;
 514         char buf[256], *cp;
 515         char remote_version[sizeof buf];
 516         size_t bufsiz;
 517         con *c = &fdcon[s];
 518
 519         for (;;) {
 520                 memset(buf, '\0', sizeof(buf));
 521                 bufsiz = sizeof(buf);
 522                 cp = buf;
 523                 while (bufsiz-- &&
 524                     (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
 525                         if (*cp == '\r')
 526                                 *cp = '\n';
 527                         cp++;
 528                 }
 529                 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
 530                         break;
 531         }
 532         if (n == 0) {
 533                 switch (errno) {
 534                 case EPIPE:
 535                         error("%s: Connection closed by remote host", c->c_name);
 536                         break;
 537                 case ECONNREFUSED:
 538                         break;
 539                 default:
 540                         error("read (%s): %s", c->c_name, strerror(errno));
 541                         break;
 542                 }
 543                 conrecycle(s);
 544                 return;
 545         }
 546         if (*cp != '\n' && *cp != '\r') {
 547                 error("%s: bad greeting", c->c_name);
 548                 confree(s);
 549                 return;
 550         }
 551         *cp = '\0';
 552         if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
 553             &remote_major, &remote_minor, remote_version) == 3)
 554                 compat_datafellows(remote_version);
 555         else
 556                 datafellows = 0;
 557         if (c->c_keytype != KT_RSA1) {
 558                 if (!ssh2_capable(remote_major, remote_minor)) {
 559                         debug("%s doesn't support ssh2", c->c_name);
 560                         confree(s);
 561                         return;
 562                 }
 563         } else if (remote_major != 1) {
 564                 debug("%s doesn't support ssh1", c->c_name);
 565                 confree(s);
 566                 return;
 567         }
 568         fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
 569         n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
 570             c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
 571             c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
 572         if (n < 0 || (size_t)n >= sizeof(buf)) {
 573                 error("snprintf: buffer too small");
 574                 confree(s);
 575                 return;
 576         }
 577         if (atomicio(vwrite, s, buf, n) != (size_t)n) {
 578                 error("write (%s): %s", c->c_name, strerror(errno));
 579                 confree(s);
 580                 return;
 581         }
 582         if (c->c_keytype != KT_RSA1) {
 583                 keyprint(c, keygrab_ssh2(c));
 584                 confree(s);
 585                 return;
 586         }
 587         c->c_status = CS_SIZE;
 588         contouch(s);
 589 }
 590
 591 static void
 592 conread(int s)
 593 {
 594         con *c = &fdcon[s];
 595         size_t n;
 596
 597         if (c->c_status == CS_CON) {
 598                 congreet(s);
 599                 return;
 600         }
 601         n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
 602         if (n == 0) {
 603                 error("read (%s): %s", c->c_name, strerror(errno));
 604                 confree(s);
 605                 return;
 606         }
 607         c->c_off += n;
 608
 609         if (c->c_off == c->c_len)
 610                 switch (c->c_status) {
 611                 case CS_SIZE:
 612                         c->c_plen = htonl(c->c_plen);
 613                         c->c_len = c->c_plen + 8 - (c->c_plen & 7);
 614                         c->c_off = 0;
 615                         c->c_data = xmalloc(c->c_len);
 616                         c->c_status = CS_KEYS;
 617                         break;
 618                 case CS_KEYS:
 619                         keyprint(c, keygrab_ssh1(c));
 620                         confree(s);
 621                         return;
 622                 default:
 623                         fatal("conread: invalid status %d", c->c_status);
 624                         break;
 625                 }
 626
 627         contouch(s);
 628 }
 629
 630 static void
 631 conloop(void)
 632 {
 633         struct timeval seltime, now;
 634         fd_set *r, *e;
 635         con *c;
 636         int i;
 637
 638         gettimeofday(&now, NULL);
 639         c = TAILQ_FIRST(&tq);
 640
 641         if (c && (c->c_tv.tv_sec > now.tv_sec ||
 642             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
 643                 seltime = c->c_tv;
 644                 seltime.tv_sec -= now.tv_sec;
 645                 seltime.tv_usec -= now.tv_usec;
 646                 if (seltime.tv_usec < 0) {
 647                         seltime.tv_usec += 1000000;
 648                         seltime.tv_sec--;
 649                 }
 650         } else
 651                 seltime.tv_sec = seltime.tv_usec = 0;
 652
 653         r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 654         e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 655         memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
 656         memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
 657
 658         while (select(maxfd, r, NULL, e, &seltime) == -1 &&
 659             (errno == EAGAIN || errno == EINTR))
 660                 ;
 661
 662         for (i = 0; i < maxfd; i++) {
 663                 if (FD_ISSET(i, e)) {
 664                         error("%s: exception!", fdcon[i].c_name);
 665                         confree(i);
 666                 } else if (FD_ISSET(i, r))
 667                         conread(i);
 668         }
 669         xfree(r);
 670         xfree(e);
 671
 672         c = TAILQ_FIRST(&tq);
 673         while (c && (c->c_tv.tv_sec < now.tv_sec ||
 674             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
 675                 int s = c->c_fd;
 676
 677                 c = TAILQ_NEXT(c, c_link);
 678                 conrecycle(s);
 679         }
 680 }
 681
 682 static void
 683 do_host(char *host)
 684 {
 685         char *name = strnnsep(&host, " \t\n");
 686         int j;
 687
 688         if (name == NULL)
 689                 return;
 690         for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
 691                 if (get_keytypes & j) {
 692                         while (ncon >= MAXCON)
 693                                 conloop();
 694                         conalloc(name, *host ? host : name, j);
 695                 }
 696         }
 697 }
 698
 699 void
 700 fatal(const char *fmt,...)
 701 {
 702         va_list args;
 703
 704         va_start(args, fmt);
 705         do_log(SYSLOG_LEVEL_FATAL, fmt, args);
 706         va_end(args);
 707         if (nonfatal_fatal)
 708                 longjmp(kexjmp, -1);
 709         else
 710                 exit(255);
 711 }
 712
 713 static void
 714 usage(void)
 715 {
 716         fprintf(stderr, "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
 717             "\t\t   [host | addrlist namelist] [...]\n",
 718             __progname);
 719         exit(1);
 720 }
 721
 722 int
 723 main(int argc, char **argv)
 724 {
 725         int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
 726         int opt, fopt_count = 0;
 727         char *tname;
 728
 729         extern int optind;
 730         extern char *optarg;
 731
 732         __progname = ssh_get_progname(argv[0]);
 733         init_rng();
 734         seed_rng();
 735         TAILQ_INIT(&tq);
 736
 737         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 738         sanitise_stdfd();
 739
 740         if (argc <= 1)
 741                 usage();
 742
 743         while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
 744                 switch (opt) {
 745                 case 'H':
 746                         hash_hosts = 1;
 747                         break;
 748                 case 'p':
 749                         ssh_port = a2port(optarg);
 750                         if (ssh_port == 0) {
 751                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 752                                 exit(1);
 753                         }
 754                         break;
 755                 case 'T':
 756                         timeout = convtime(optarg);
 757                         if (timeout == -1 || timeout == 0) {
 758                                 fprintf(stderr, "Bad timeout '%s'\n", optarg);
 759                                 usage();
 760                         }
 761                         break;
 762                 case 'v':
 763                         if (!debug_flag) {
 764                                 debug_flag = 1;
 765                                 log_level = SYSLOG_LEVEL_DEBUG1;
 766                         }
 767                         else if (log_level < SYSLOG_LEVEL_DEBUG3)
 768                                 log_level++;
 769                         else
 770                                 fatal("Too high debugging level.");
 771                         break;
 772                 case 'f':
 773                         if (strcmp(optarg, "-") == 0)
 774                                 optarg = NULL;
 775                         argv[fopt_count++] = optarg;
 776                         break;
 777                 case 't':
 778                         get_keytypes = 0;
 779                         tname = strtok(optarg, ",");
 780                         while (tname) {
 781                                 int type = key_type_from_name(tname);
 782                                 switch (type) {
 783                                 case KEY_RSA1:
 784                                         get_keytypes |= KT_RSA1;
 785                                         break;
 786                                 case KEY_DSA:
 787                                         get_keytypes |= KT_DSA;
 788                                         break;
 789                                 case KEY_RSA:
 790                                         get_keytypes |= KT_RSA;
 791                                         break;
 792                                 case KEY_UNSPEC:
 793                                         fatal("unknown key type %s", tname);
 794                                 }
 795                                 tname = strtok(NULL, ",");
 796                         }
 797                         break;
 798                 case '4':
 799                         IPv4or6 = AF_INET;
 800                         break;
 801                 case '6':
 802                         IPv4or6 = AF_INET6;
 803                         break;
 804                 case '?':
 805                 default:
 806                         usage();
 807                 }
 808         }
 809         if (optind == argc && !fopt_count)
 810                 usage();
 811
 812         log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
 813
 814         maxfd = fdlim_get(1);
 815         if (maxfd < 0)
 816                 fatal("%s: fdlim_get: bad value", __progname);
 817         if (maxfd > MAXMAXFD)
 818                 maxfd = MAXMAXFD;
 819         if (MAXCON <= 0)
 820                 fatal("%s: not enough file descriptors", __progname);
 821         if (maxfd > fdlim_get(0))
 822                 fdlim_set(maxfd);
 823         fdcon = xcalloc(maxfd, sizeof(con));
 824
 825         read_wait_nfdset = howmany(maxfd, NFDBITS);
 826         read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 827
 828         if (fopt_count) {
 829                 Linebuf *lb;
 830                 char *line;
 831                 int j;
 832
 833                 for (j = 0; j < fopt_count; j++) {
 834                         lb = Linebuf_alloc(argv[j], error);
 835                         if (!lb)
 836                                 continue;
 837                         while ((line = Linebuf_getline(lb)) != NULL)
 838                                 do_host(line);
 839                         Linebuf_free(lb);
 840                 }
 841         }
 842
 843         while (optind < argc)
 844                 do_host(argv[optind++]);
 845
 846         while (ncon > 0)
 847                 conloop();
 848
 849         return (0);
 850 }