xref: /freebsd/crypto/openssh/ssh-keyscan.c (revision 87569f75a91f298c52a71823c04d41cf53c88889) 
1 /*
2  * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
3  *
4  * Modification and redistribution in source and binary forms is
5  * permitted provided that due credit is given to the author and the
6  * OpenBSD project by leaving this copyright notice intact.
7  */
8 
9 #include "includes.h"
10 RCSID("$OpenBSD: ssh-keyscan.c,v 1.55 2005/06/17 02:44:33 djm Exp $");
11 
12 #include "openbsd-compat/sys-queue.h"
13 
14 #include <openssl/bn.h>
15 
16 #include <setjmp.h>
17 #include "xmalloc.h"
18 #include "ssh.h"
19 #include "ssh1.h"
20 #include "key.h"
21 #include "kex.h"
22 #include "compat.h"
23 #include "myproposal.h"
24 #include "packet.h"
25 #include "dispatch.h"
26 #include "buffer.h"
27 #include "bufaux.h"
28 #include "log.h"
29 #include "atomicio.h"
30 #include "misc.h"
31 #include "hostfile.h"
32 
33 /* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
34    Default value is AF_UNSPEC means both IPv4 and IPv6. */
35 int IPv4or6 = AF_UNSPEC;
36 
37 int ssh_port = SSH_DEFAULT_PORT;
38 
39 #define KT_RSA1	1
40 #define KT_DSA	2
41 #define KT_RSA	4
42 
43 int get_keytypes = KT_RSA1;	/* Get only RSA1 keys by default */
44 
45 int hash_hosts = 0;		/* Hash hostname on output */
46 
47 #define MAXMAXFD 256
48 
49 /* The number of seconds after which to give up on a TCP connection */
50 int timeout = 5;
51 
52 int maxfd;
53 #define MAXCON (maxfd - 10)
54 
55 extern char *__progname;
56 fd_set *read_wait;
57 size_t read_wait_size;
58 int ncon;
59 int nonfatal_fatal = 0;
60 jmp_buf kexjmp;
61 Key *kexjmp_key;
62 
63 /*
64  * Keep a connection structure for each file descriptor.  The state
65  * associated with file descriptor n is held in fdcon[n].
66  */
67 typedef struct Connection {
68 	u_char c_status;	/* State of connection on this file desc. */
69 #define CS_UNUSED 0		/* File descriptor unused */
70 #define CS_CON 1		/* Waiting to connect/read greeting */
71 #define CS_SIZE 2		/* Waiting to read initial packet size */
72 #define CS_KEYS 3		/* Waiting to read public key packet */
73 	int c_fd;		/* Quick lookup: c->c_fd == c - fdcon */
74 	int c_plen;		/* Packet length field for ssh packet */
75 	int c_len;		/* Total bytes which must be read. */
76 	int c_off;		/* Length of data read so far. */
77 	int c_keytype;		/* Only one of KT_RSA1, KT_DSA, or KT_RSA */
78 	char *c_namebase;	/* Address to free for c_name and c_namelist */
79 	char *c_name;		/* Hostname of connection for errors */
80 	char *c_namelist;	/* Pointer to other possible addresses */
81 	char *c_output_name;	/* Hostname of connection for output */
82 	char *c_data;		/* Data read from this fd */
83 	Kex *c_kex;		/* The key-exchange struct for ssh2 */
84 	struct timeval c_tv;	/* Time at which connection gets aborted */
85 	TAILQ_ENTRY(Connection) c_link;	/* List of connections in timeout order. */
86 } con;
87 
88 TAILQ_HEAD(conlist, Connection) tq;	/* Timeout Queue */
89 con *fdcon;
90 
91 /*
92  *  This is just a wrapper around fgets() to make it usable.
93  */
94 
95 /* Stress-test.  Increase this later. */
96 #define LINEBUF_SIZE 16
97 
98 typedef struct {
99 	char *buf;
100 	u_int size;
101 	int lineno;
102 	const char *filename;
103 	FILE *stream;
104 	void (*errfun) (const char *,...);
105 } Linebuf;
106 
107 static Linebuf *
108 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
109 {
110 	Linebuf *lb;
111 
112 	if (!(lb = malloc(sizeof(*lb)))) {
113 		if (errfun)
114 			(*errfun) ("linebuf (%s): malloc failed\n",
115 			    filename ? filename : "(stdin)");
116 		return (NULL);
117 	}
118 	if (filename) {
119 		lb->filename = filename;
120 		if (!(lb->stream = fopen(filename, "r"))) {
121 			xfree(lb);
122 			if (errfun)
123 				(*errfun) ("%s: %s\n", filename, strerror(errno));
124 			return (NULL);
125 		}
126 	} else {
127 		lb->filename = "(stdin)";
128 		lb->stream = stdin;
129 	}
130 
131 	if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
132 		if (errfun)
133 			(*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
134 		xfree(lb);
135 		return (NULL);
136 	}
137 	lb->errfun = errfun;
138 	lb->lineno = 0;
139 	return (lb);
140 }
141 
142 static void
143 Linebuf_free(Linebuf * lb)
144 {
145 	fclose(lb->stream);
146 	xfree(lb->buf);
147 	xfree(lb);
148 }
149 
150 #if 0
151 static void
152 Linebuf_restart(Linebuf * lb)
153 {
154 	clearerr(lb->stream);
155 	rewind(lb->stream);
156 	lb->lineno = 0;
157 }
158 
159 static int
160 Linebuf_lineno(Linebuf * lb)
161 {
162 	return (lb->lineno);
163 }
164 #endif
165 
166 static char *
167 Linebuf_getline(Linebuf * lb)
168 {
169 	size_t n = 0;
170 	void *p;
171 
172 	lb->lineno++;
173 	for (;;) {
174 		/* Read a line */
175 		if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
176 			if (ferror(lb->stream) && lb->errfun)
177 				(*lb->errfun)("%s: %s\n", lb->filename,
178 				    strerror(errno));
179 			return (NULL);
180 		}
181 		n = strlen(lb->buf);
182 
183 		/* Return it or an error if it fits */
184 		if (n > 0 && lb->buf[n - 1] == '\n') {
185 			lb->buf[n - 1] = '\0';
186 			return (lb->buf);
187 		}
188 		if (n != lb->size - 1) {
189 			if (lb->errfun)
190 				(*lb->errfun)("%s: skipping incomplete last line\n",
191 				    lb->filename);
192 			return (NULL);
193 		}
194 		/* Double the buffer if we need more space */
195 		lb->size *= 2;
196 		if ((p = realloc(lb->buf, lb->size)) == NULL) {
197 			lb->size /= 2;
198 			if (lb->errfun)
199 				(*lb->errfun)("linebuf (%s): realloc failed\n",
200 				    lb->filename);
201 			return (NULL);
202 		}
203 		lb->buf = p;
204 	}
205 }
206 
207 static int
208 fdlim_get(int hard)
209 {
210 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
211 	struct rlimit rlfd;
212 
213 	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
214 		return (-1);
215 	if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
216 		return SSH_SYSFDMAX;
217 	else
218 		return hard ? rlfd.rlim_max : rlfd.rlim_cur;
219 #else
220 	return SSH_SYSFDMAX;
221 #endif
222 }
223 
224 static int
225 fdlim_set(int lim)
226 {
227 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
228 	struct rlimit rlfd;
229 #endif
230 
231 	if (lim <= 0)
232 		return (-1);
233 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
234 	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
235 		return (-1);
236 	rlfd.rlim_cur = lim;
237 	if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
238 		return (-1);
239 #elif defined (HAVE_SETDTABLESIZE)
240 	setdtablesize(lim);
241 #endif
242 	return (0);
243 }
244 
245 /*
246  * This is an strsep function that returns a null field for adjacent
247  * separators.  This is the same as the 4.4BSD strsep, but different from the
248  * one in the GNU libc.
249  */
250 static char *
251 xstrsep(char **str, const char *delim)
252 {
253 	char *s, *e;
254 
255 	if (!**str)
256 		return (NULL);
257 
258 	s = *str;
259 	e = s + strcspn(s, delim);
260 
261 	if (*e != '\0')
262 		*e++ = '\0';
263 	*str = e;
264 
265 	return (s);
266 }
267 
268 /*
269  * Get the next non-null token (like GNU strsep).  Strsep() will return a
270  * null token for two adjacent separators, so we may have to loop.
271  */
272 static char *
273 strnnsep(char **stringp, char *delim)
274 {
275 	char *tok;
276 
277 	do {
278 		tok = xstrsep(stringp, delim);
279 	} while (tok && *tok == '\0');
280 	return (tok);
281 }
282 
283 static Key *
284 keygrab_ssh1(con *c)
285 {
286 	static Key *rsa;
287 	static Buffer msg;
288 
289 	if (rsa == NULL) {
290 		buffer_init(&msg);
291 		rsa = key_new(KEY_RSA1);
292 	}
293 	buffer_append(&msg, c->c_data, c->c_plen);
294 	buffer_consume(&msg, 8 - (c->c_plen & 7));	/* padding */
295 	if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
296 		error("%s: invalid packet type", c->c_name);
297 		buffer_clear(&msg);
298 		return NULL;
299 	}
300 	buffer_consume(&msg, 8);		/* cookie */
301 
302 	/* server key */
303 	(void) buffer_get_int(&msg);
304 	buffer_get_bignum(&msg, rsa->rsa->e);
305 	buffer_get_bignum(&msg, rsa->rsa->n);
306 
307 	/* host key */
308 	(void) buffer_get_int(&msg);
309 	buffer_get_bignum(&msg, rsa->rsa->e);
310 	buffer_get_bignum(&msg, rsa->rsa->n);
311 
312 	buffer_clear(&msg);
313 
314 	return (rsa);
315 }
316 
317 static int
318 hostjump(Key *hostkey)
319 {
320 	kexjmp_key = hostkey;
321 	longjmp(kexjmp, 1);
322 }
323 
324 static int
325 ssh2_capable(int remote_major, int remote_minor)
326 {
327 	switch (remote_major) {
328 	case 1:
329 		if (remote_minor == 99)
330 			return 1;
331 		break;
332 	case 2:
333 		return 1;
334 	default:
335 		break;
336 	}
337 	return 0;
338 }
339 
340 static Key *
341 keygrab_ssh2(con *c)
342 {
343 	int j;
344 
345 	packet_set_connection(c->c_fd, c->c_fd);
346 	enable_compat20();
347 	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
348 	    "ssh-dss": "ssh-rsa";
349 	c->c_kex = kex_setup(myproposal);
350 	c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
351 	c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
352 	c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
353 	c->c_kex->verify_host_key = hostjump;
354 
355 	if (!(j = setjmp(kexjmp))) {
356 		nonfatal_fatal = 1;
357 		dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
358 		fprintf(stderr, "Impossible! dispatch_run() returned!\n");
359 		exit(1);
360 	}
361 	nonfatal_fatal = 0;
362 	xfree(c->c_kex);
363 	c->c_kex = NULL;
364 	packet_close();
365 
366 	return j < 0? NULL : kexjmp_key;
367 }
368 
369 static void
370 keyprint(con *c, Key *key)
371 {
372 	char *host = c->c_output_name ? c->c_output_name : c->c_name;
373 
374 	if (!key)
375 		return;
376 	if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
377 		fatal("host_hash failed");
378 
379 	fprintf(stdout, "%s ", host);
380 	key_write(key, stdout);
381 	fputs("\n", stdout);
382 }
383 
384 static int
385 tcpconnect(char *host)
386 {
387 	struct addrinfo hints, *ai, *aitop;
388 	char strport[NI_MAXSERV];
389 	int gaierr, s = -1;
390 
391 	snprintf(strport, sizeof strport, "%d", ssh_port);
392 	memset(&hints, 0, sizeof(hints));
393 	hints.ai_family = IPv4or6;
394 	hints.ai_socktype = SOCK_STREAM;
395 	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
396 		fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
397 	for (ai = aitop; ai; ai = ai->ai_next) {
398 		s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
399 		if (s < 0) {
400 			error("socket: %s", strerror(errno));
401 			continue;
402 		}
403 		if (set_nonblock(s) == -1)
404 			fatal("%s: set_nonblock(%d)", __func__, s);
405 		if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
406 		    errno != EINPROGRESS)
407 			error("connect (`%s'): %s", host, strerror(errno));
408 		else
409 			break;
410 		close(s);
411 		s = -1;
412 	}
413 	freeaddrinfo(aitop);
414 	return s;
415 }
416 
417 static int
418 conalloc(char *iname, char *oname, int keytype)
419 {
420 	char *namebase, *name, *namelist;
421 	int s;
422 
423 	namebase = namelist = xstrdup(iname);
424 
425 	do {
426 		name = xstrsep(&namelist, ",");
427 		if (!name) {
428 			xfree(namebase);
429 			return (-1);
430 		}
431 	} while ((s = tcpconnect(name)) < 0);
432 
433 	if (s >= maxfd)
434 		fatal("conalloc: fdno %d too high", s);
435 	if (fdcon[s].c_status)
436 		fatal("conalloc: attempt to reuse fdno %d", s);
437 
438 	fdcon[s].c_fd = s;
439 	fdcon[s].c_status = CS_CON;
440 	fdcon[s].c_namebase = namebase;
441 	fdcon[s].c_name = name;
442 	fdcon[s].c_namelist = namelist;
443 	fdcon[s].c_output_name = xstrdup(oname);
444 	fdcon[s].c_data = (char *) &fdcon[s].c_plen;
445 	fdcon[s].c_len = 4;
446 	fdcon[s].c_off = 0;
447 	fdcon[s].c_keytype = keytype;
448 	gettimeofday(&fdcon[s].c_tv, NULL);
449 	fdcon[s].c_tv.tv_sec += timeout;
450 	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
451 	FD_SET(s, read_wait);
452 	ncon++;
453 	return (s);
454 }
455 
456 static void
457 confree(int s)
458 {
459 	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
460 		fatal("confree: attempt to free bad fdno %d", s);
461 	close(s);
462 	xfree(fdcon[s].c_namebase);
463 	xfree(fdcon[s].c_output_name);
464 	if (fdcon[s].c_status == CS_KEYS)
465 		xfree(fdcon[s].c_data);
466 	fdcon[s].c_status = CS_UNUSED;
467 	fdcon[s].c_keytype = 0;
468 	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
469 	FD_CLR(s, read_wait);
470 	ncon--;
471 }
472 
473 static void
474 contouch(int s)
475 {
476 	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
477 	gettimeofday(&fdcon[s].c_tv, NULL);
478 	fdcon[s].c_tv.tv_sec += timeout;
479 	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
480 }
481 
482 static int
483 conrecycle(int s)
484 {
485 	con *c = &fdcon[s];
486 	int ret;
487 
488 	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
489 	confree(s);
490 	return (ret);
491 }
492 
493 static void
494 congreet(int s)
495 {
496 	int n = 0, remote_major = 0, remote_minor = 0;
497 	char buf[256], *cp;
498 	char remote_version[sizeof buf];
499 	size_t bufsiz;
500 	con *c = &fdcon[s];
501 
502 	bufsiz = sizeof(buf);
503 	cp = buf;
504 	while (bufsiz-- && (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
505 		if (*cp == '\r')
506 			*cp = '\n';
507 		cp++;
508 	}
509 	if (n == 0) {
510 		switch (errno) {
511 		case EPIPE:
512 			error("%s: Connection closed by remote host", c->c_name);
513 			break;
514 		case ECONNREFUSED:
515 			break;
516 		default:
517 			error("read (%s): %s", c->c_name, strerror(errno));
518 			break;
519 		}
520 		conrecycle(s);
521 		return;
522 	}
523 	if (*cp != '\n' && *cp != '\r') {
524 		error("%s: bad greeting", c->c_name);
525 		confree(s);
526 		return;
527 	}
528 	*cp = '\0';
529 	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
530 	    &remote_major, &remote_minor, remote_version) == 3)
531 		compat_datafellows(remote_version);
532 	else
533 		datafellows = 0;
534 	if (c->c_keytype != KT_RSA1) {
535 		if (!ssh2_capable(remote_major, remote_minor)) {
536 			debug("%s doesn't support ssh2", c->c_name);
537 			confree(s);
538 			return;
539 		}
540 	} else if (remote_major != 1) {
541 		debug("%s doesn't support ssh1", c->c_name);
542 		confree(s);
543 		return;
544 	}
545 	fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
546 	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
547 	    c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
548 	    c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
549 	if (n < 0 || (size_t)n >= sizeof(buf)) {
550 		error("snprintf: buffer too small");
551 		confree(s);
552 		return;
553 	}
554 	if (atomicio(vwrite, s, buf, n) != (size_t)n) {
555 		error("write (%s): %s", c->c_name, strerror(errno));
556 		confree(s);
557 		return;
558 	}
559 	if (c->c_keytype != KT_RSA1) {
560 		keyprint(c, keygrab_ssh2(c));
561 		confree(s);
562 		return;
563 	}
564 	c->c_status = CS_SIZE;
565 	contouch(s);
566 }
567 
568 static void
569 conread(int s)
570 {
571 	con *c = &fdcon[s];
572 	size_t n;
573 
574 	if (c->c_status == CS_CON) {
575 		congreet(s);
576 		return;
577 	}
578 	n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
579 	if (n == 0) {
580 		error("read (%s): %s", c->c_name, strerror(errno));
581 		confree(s);
582 		return;
583 	}
584 	c->c_off += n;
585 
586 	if (c->c_off == c->c_len)
587 		switch (c->c_status) {
588 		case CS_SIZE:
589 			c->c_plen = htonl(c->c_plen);
590 			c->c_len = c->c_plen + 8 - (c->c_plen & 7);
591 			c->c_off = 0;
592 			c->c_data = xmalloc(c->c_len);
593 			c->c_status = CS_KEYS;
594 			break;
595 		case CS_KEYS:
596 			keyprint(c, keygrab_ssh1(c));
597 			confree(s);
598 			return;
599 			break;
600 		default:
601 			fatal("conread: invalid status %d", c->c_status);
602 			break;
603 		}
604 
605 	contouch(s);
606 }
607 
608 static void
609 conloop(void)
610 {
611 	struct timeval seltime, now;
612 	fd_set *r, *e;
613 	con *c;
614 	int i;
615 
616 	gettimeofday(&now, NULL);
617 	c = TAILQ_FIRST(&tq);
618 
619 	if (c && (c->c_tv.tv_sec > now.tv_sec ||
620 	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
621 		seltime = c->c_tv;
622 		seltime.tv_sec -= now.tv_sec;
623 		seltime.tv_usec -= now.tv_usec;
624 		if (seltime.tv_usec < 0) {
625 			seltime.tv_usec += 1000000;
626 			seltime.tv_sec--;
627 		}
628 	} else
629 		seltime.tv_sec = seltime.tv_usec = 0;
630 
631 	r = xmalloc(read_wait_size);
632 	memcpy(r, read_wait, read_wait_size);
633 	e = xmalloc(read_wait_size);
634 	memcpy(e, read_wait, read_wait_size);
635 
636 	while (select(maxfd, r, NULL, e, &seltime) == -1 &&
637 	    (errno == EAGAIN || errno == EINTR))
638 		;
639 
640 	for (i = 0; i < maxfd; i++) {
641 		if (FD_ISSET(i, e)) {
642 			error("%s: exception!", fdcon[i].c_name);
643 			confree(i);
644 		} else if (FD_ISSET(i, r))
645 			conread(i);
646 	}
647 	xfree(r);
648 	xfree(e);
649 
650 	c = TAILQ_FIRST(&tq);
651 	while (c && (c->c_tv.tv_sec < now.tv_sec ||
652 	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
653 		int s = c->c_fd;
654 
655 		c = TAILQ_NEXT(c, c_link);
656 		conrecycle(s);
657 	}
658 }
659 
660 static void
661 do_host(char *host)
662 {
663 	char *name = strnnsep(&host, " \t\n");
664 	int j;
665 
666 	if (name == NULL)
667 		return;
668 	for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
669 		if (get_keytypes & j) {
670 			while (ncon >= MAXCON)
671 				conloop();
672 			conalloc(name, *host ? host : name, j);
673 		}
674 	}
675 }
676 
677 void
678 fatal(const char *fmt,...)
679 {
680 	va_list args;
681 
682 	va_start(args, fmt);
683 	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
684 	va_end(args);
685 	if (nonfatal_fatal)
686 		longjmp(kexjmp, -1);
687 	else
688 		exit(255);
689 }
690 
691 static void
692 usage(void)
693 {
694 	fprintf(stderr, "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
695 	    "\t\t   [host | addrlist namelist] [...]\n",
696 	    __progname);
697 	exit(1);
698 }
699 
700 int
701 main(int argc, char **argv)
702 {
703 	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
704 	int opt, fopt_count = 0;
705 	char *tname;
706 
707 	extern int optind;
708 	extern char *optarg;
709 
710 	__progname = ssh_get_progname(argv[0]);
711 	init_rng();
712 	seed_rng();
713 	TAILQ_INIT(&tq);
714 
715 	if (argc <= 1)
716 		usage();
717 
718 	while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
719 		switch (opt) {
720 		case 'H':
721 			hash_hosts = 1;
722 			break;
723 		case 'p':
724 			ssh_port = a2port(optarg);
725 			if (ssh_port == 0) {
726 				fprintf(stderr, "Bad port '%s'\n", optarg);
727 				exit(1);
728 			}
729 			break;
730 		case 'T':
731 			timeout = convtime(optarg);
732 			if (timeout == -1 || timeout == 0) {
733 				fprintf(stderr, "Bad timeout '%s'\n", optarg);
734 				usage();
735 			}
736 			break;
737 		case 'v':
738 			if (!debug_flag) {
739 				debug_flag = 1;
740 				log_level = SYSLOG_LEVEL_DEBUG1;
741 			}
742 			else if (log_level < SYSLOG_LEVEL_DEBUG3)
743 				log_level++;
744 			else
745 				fatal("Too high debugging level.");
746 			break;
747 		case 'f':
748 			if (strcmp(optarg, "-") == 0)
749 				optarg = NULL;
750 			argv[fopt_count++] = optarg;
751 			break;
752 		case 't':
753 			get_keytypes = 0;
754 			tname = strtok(optarg, ",");
755 			while (tname) {
756 				int type = key_type_from_name(tname);
757 				switch (type) {
758 				case KEY_RSA1:
759 					get_keytypes |= KT_RSA1;
760 					break;
761 				case KEY_DSA:
762 					get_keytypes |= KT_DSA;
763 					break;
764 				case KEY_RSA:
765 					get_keytypes |= KT_RSA;
766 					break;
767 				case KEY_UNSPEC:
768 					fatal("unknown key type %s", tname);
769 				}
770 				tname = strtok(NULL, ",");
771 			}
772 			break;
773 		case '4':
774 			IPv4or6 = AF_INET;
775 			break;
776 		case '6':
777 			IPv4or6 = AF_INET6;
778 			break;
779 		case '?':
780 		default:
781 			usage();
782 		}
783 	}
784 	if (optind == argc && !fopt_count)
785 		usage();
786 
787 	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
788 
789 	maxfd = fdlim_get(1);
790 	if (maxfd < 0)
791 		fatal("%s: fdlim_get: bad value", __progname);
792 	if (maxfd > MAXMAXFD)
793 		maxfd = MAXMAXFD;
794 	if (MAXCON <= 0)
795 		fatal("%s: not enough file descriptors", __progname);
796 	if (maxfd > fdlim_get(0))
797 		fdlim_set(maxfd);
798 	fdcon = xmalloc(maxfd * sizeof(con));
799 	memset(fdcon, 0, maxfd * sizeof(con));
800 
801 	read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
802 	read_wait = xmalloc(read_wait_size);
803 	memset(read_wait, 0, read_wait_size);
804 
805 	if (fopt_count) {
806 		Linebuf *lb;
807 		char *line;
808 		int j;
809 
810 		for (j = 0; j < fopt_count; j++) {
811 			lb = Linebuf_alloc(argv[j], error);
812 			if (!lb)
813 				continue;
814 			while ((line = Linebuf_getline(lb)) != NULL)
815 				do_host(line);
816 			Linebuf_free(lb);
817 		}
818 	}
819 
820 	while (optind < argc)
821 		do_host(argv[optind++]);
822 
823 	while (ncon > 0)
824 		conloop();
825 
826 	return (0);
827 }
828