xref: /freebsd/crypto/openssh/ssh-keyscan.c (revision c4f6a2a9e1b1879b618c436ab4f56ff75c73a0f5) 
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 1.36 2002/06/16 21:30:58 itojun Exp $");
11 
12 #include "openbsd-compat/fake-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 
32 /* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
33    Default value is AF_UNSPEC means both IPv4 and IPv6. */
34 #ifdef IPV4_DEFAULT
35 int IPv4or6 = AF_INET;
36 #else
37 int IPv4or6 = AF_UNSPEC;
38 #endif
39 
40 int ssh_port = SSH_DEFAULT_PORT;
41 
42 #define KT_RSA1	1
43 #define KT_DSA	2
44 #define KT_RSA	4
45 
46 int get_keytypes = KT_RSA1;	/* Get only RSA1 keys by default */
47 
48 #define MAXMAXFD 256
49 
50 /* The number of seconds after which to give up on a TCP connection */
51 int timeout = 5;
52 
53 int maxfd;
54 #define MAXCON (maxfd - 10)
55 
56 #ifdef HAVE___PROGNAME
57 extern char *__progname;
58 #else
59 char *__progname;
60 #endif
61 fd_set *read_wait;
62 size_t read_wait_size;
63 int ncon;
64 int nonfatal_fatal = 0;
65 jmp_buf kexjmp;
66 Key *kexjmp_key;
67 
68 /*
69  * Keep a connection structure for each file descriptor.  The state
70  * associated with file descriptor n is held in fdcon[n].
71  */
72 typedef struct Connection {
73 	u_char c_status;	/* State of connection on this file desc. */
74 #define CS_UNUSED 0		/* File descriptor unused */
75 #define CS_CON 1		/* Waiting to connect/read greeting */
76 #define CS_SIZE 2		/* Waiting to read initial packet size */
77 #define CS_KEYS 3		/* Waiting to read public key packet */
78 	int c_fd;		/* Quick lookup: c->c_fd == c - fdcon */
79 	int c_plen;		/* Packet length field for ssh packet */
80 	int c_len;		/* Total bytes which must be read. */
81 	int c_off;		/* Length of data read so far. */
82 	int c_keytype;		/* Only one of KT_RSA1, KT_DSA, or KT_RSA */
83 	char *c_namebase;	/* Address to free for c_name and c_namelist */
84 	char *c_name;		/* Hostname of connection for errors */
85 	char *c_namelist;	/* Pointer to other possible addresses */
86 	char *c_output_name;	/* Hostname of connection for output */
87 	char *c_data;		/* Data read from this fd */
88 	Kex *c_kex;		/* The key-exchange struct for ssh2 */
89 	struct timeval c_tv;	/* Time at which connection gets aborted */
90 	TAILQ_ENTRY(Connection) c_link;	/* List of connections in timeout order. */
91 } con;
92 
93 TAILQ_HEAD(conlist, Connection) tq;	/* Timeout Queue */
94 con *fdcon;
95 
96 /*
97  *  This is just a wrapper around fgets() to make it usable.
98  */
99 
100 /* Stress-test.  Increase this later. */
101 #define LINEBUF_SIZE 16
102 
103 typedef struct {
104 	char *buf;
105 	u_int size;
106 	int lineno;
107 	const char *filename;
108 	FILE *stream;
109 	void (*errfun) (const char *,...);
110 } Linebuf;
111 
112 static Linebuf *
113 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
114 {
115 	Linebuf *lb;
116 
117 	if (!(lb = malloc(sizeof(*lb)))) {
118 		if (errfun)
119 			(*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
120 		return (NULL);
121 	}
122 	if (filename) {
123 		lb->filename = filename;
124 		if (!(lb->stream = fopen(filename, "r"))) {
125 			xfree(lb);
126 			if (errfun)
127 				(*errfun) ("%s: %s\n", filename, strerror(errno));
128 			return (NULL);
129 		}
130 	} else {
131 		lb->filename = "(stdin)";
132 		lb->stream = stdin;
133 	}
134 
135 	if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
136 		if (errfun)
137 			(*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
138 		xfree(lb);
139 		return (NULL);
140 	}
141 	lb->errfun = errfun;
142 	lb->lineno = 0;
143 	return (lb);
144 }
145 
146 static void
147 Linebuf_free(Linebuf * lb)
148 {
149 	fclose(lb->stream);
150 	xfree(lb->buf);
151 	xfree(lb);
152 }
153 
154 #if 0
155 static void
156 Linebuf_restart(Linebuf * lb)
157 {
158 	clearerr(lb->stream);
159 	rewind(lb->stream);
160 	lb->lineno = 0;
161 }
162 
163 static int
164 Linebuf_lineno(Linebuf * lb)
165 {
166 	return (lb->lineno);
167 }
168 #endif
169 
170 static char *
171 Linebuf_getline(Linebuf * lb)
172 {
173 	int n = 0;
174 
175 	lb->lineno++;
176 	for (;;) {
177 		/* Read a line */
178 		if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
179 			if (ferror(lb->stream) && lb->errfun)
180 				(*lb->errfun) ("%s: %s\n", lb->filename,
181 				    strerror(errno));
182 			return (NULL);
183 		}
184 		n = strlen(lb->buf);
185 
186 		/* Return it or an error if it fits */
187 		if (n > 0 && lb->buf[n - 1] == '\n') {
188 			lb->buf[n - 1] = '\0';
189 			return (lb->buf);
190 		}
191 		if (n != lb->size - 1) {
192 			if (lb->errfun)
193 				(*lb->errfun) ("%s: skipping incomplete last line\n",
194 				    lb->filename);
195 			return (NULL);
196 		}
197 		/* Double the buffer if we need more space */
198 		if (!(lb->buf = realloc(lb->buf, (lb->size *= 2)))) {
199 			if (lb->errfun)
200 				(*lb->errfun) ("linebuf (%s): realloc failed\n",
201 				    lb->filename);
202 			return (NULL);
203 		}
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 10000;
217 	else
218 		return hard ? rlfd.rlim_max : rlfd.rlim_cur;
219 #elif defined (HAVE_SYSCONF)
220 	return sysconf (_SC_OPEN_MAX);
221 #else
222 	return 10000;
223 #endif
224 }
225 
226 static int
227 fdlim_set(int lim)
228 {
229 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
230 	struct rlimit rlfd;
231 #endif
232 	if (lim <= 0)
233 		return (-1);
234 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
235 	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
236 		return (-1);
237 	rlfd.rlim_cur = lim;
238 	if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
239 		return (-1);
240 #elif defined (HAVE_SETDTABLESIZE)
241 	setdtablesize(lim);
242 #endif
243 	return (0);
244 }
245 
246 /*
247  * This is an strsep function that returns a null field for adjacent
248  * separators.  This is the same as the 4.4BSD strsep, but different from the
249  * one in the GNU libc.
250  */
251 static char *
252 xstrsep(char **str, const char *delim)
253 {
254 	char *s, *e;
255 
256 	if (!**str)
257 		return (NULL);
258 
259 	s = *str;
260 	e = s + strcspn(s, delim);
261 
262 	if (*e != '\0')
263 		*e++ = '\0';
264 	*str = e;
265 
266 	return (s);
267 }
268 
269 /*
270  * Get the next non-null token (like GNU strsep).  Strsep() will return a
271  * null token for two adjacent separators, so we may have to loop.
272  */
273 static char *
274 strnnsep(char **stringp, char *delim)
275 {
276 	char *tok;
277 
278 	do {
279 		tok = xstrsep(stringp, delim);
280 	} while (tok && *tok == '\0');
281 	return (tok);
282 }
283 
284 static Key *
285 keygrab_ssh1(con *c)
286 {
287 	static Key *rsa;
288 	static Buffer msg;
289 
290 	if (rsa == NULL) {
291 		buffer_init(&msg);
292 		rsa = key_new(KEY_RSA1);
293 	}
294 	buffer_append(&msg, c->c_data, c->c_plen);
295 	buffer_consume(&msg, 8 - (c->c_plen & 7));	/* padding */
296 	if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
297 		error("%s: invalid packet type", c->c_name);
298 		buffer_clear(&msg);
299 		return NULL;
300 	}
301 	buffer_consume(&msg, 8);		/* cookie */
302 
303 	/* server key */
304 	(void) buffer_get_int(&msg);
305 	buffer_get_bignum(&msg, rsa->rsa->e);
306 	buffer_get_bignum(&msg, rsa->rsa->n);
307 
308 	/* host key */
309 	(void) buffer_get_int(&msg);
310 	buffer_get_bignum(&msg, rsa->rsa->e);
311 	buffer_get_bignum(&msg, rsa->rsa->n);
312 
313 	buffer_clear(&msg);
314 
315 	return (rsa);
316 }
317 
318 static int
319 hostjump(Key *hostkey)
320 {
321 	kexjmp_key = hostkey;
322 	longjmp(kexjmp, 1);
323 }
324 
325 static int
326 ssh2_capable(int remote_major, int remote_minor)
327 {
328 	switch (remote_major) {
329 	case 1:
330 		if (remote_minor == 99)
331 			return 1;
332 		break;
333 	case 2:
334 		return 1;
335 	default:
336 		break;
337 	}
338 	return 0;
339 }
340 
341 static Key *
342 keygrab_ssh2(con *c)
343 {
344 	int j;
345 
346 	packet_set_connection(c->c_fd, c->c_fd);
347 	enable_compat20();
348 	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
349 	    "ssh-dss": "ssh-rsa";
350 	c->c_kex = kex_setup(myproposal);
351 	c->c_kex->verify_host_key = hostjump;
352 
353 	if (!(j = setjmp(kexjmp))) {
354 		nonfatal_fatal = 1;
355 		dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
356 		fprintf(stderr, "Impossible! dispatch_run() returned!\n");
357 		exit(1);
358 	}
359 	nonfatal_fatal = 0;
360 	xfree(c->c_kex);
361 	c->c_kex = NULL;
362 	packet_close();
363 
364 	return j < 0? NULL : kexjmp_key;
365 }
366 
367 static void
368 keyprint(con *c, Key *key)
369 {
370 	if (!key)
371 		return;
372 
373 	fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
374 	key_write(key, stdout);
375 	fputs("\n", stdout);
376 }
377 
378 static int
379 tcpconnect(char *host)
380 {
381 	struct addrinfo hints, *ai, *aitop;
382 	char strport[NI_MAXSERV];
383 	int gaierr, s = -1;
384 
385 	snprintf(strport, sizeof strport, "%d", ssh_port);
386 	memset(&hints, 0, sizeof(hints));
387 	hints.ai_family = IPv4or6;
388 	hints.ai_socktype = SOCK_STREAM;
389 	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
390 		fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
391 	for (ai = aitop; ai; ai = ai->ai_next) {
392 		s = socket(ai->ai_family, SOCK_STREAM, 0);
393 		if (s < 0) {
394 			error("socket: %s", strerror(errno));
395 			continue;
396 		}
397 		if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
398 			fatal("F_SETFL: %s", strerror(errno));
399 		if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
400 		    errno != EINPROGRESS)
401 			error("connect (`%s'): %s", host, strerror(errno));
402 		else
403 			break;
404 		close(s);
405 		s = -1;
406 	}
407 	freeaddrinfo(aitop);
408 	return s;
409 }
410 
411 static int
412 conalloc(char *iname, char *oname, int keytype)
413 {
414 	int s;
415 	char *namebase, *name, *namelist;
416 
417 	namebase = namelist = xstrdup(iname);
418 
419 	do {
420 		name = xstrsep(&namelist, ",");
421 		if (!name) {
422 			xfree(namebase);
423 			return (-1);
424 		}
425 	} while ((s = tcpconnect(name)) < 0);
426 
427 	if (s >= maxfd)
428 		fatal("conalloc: fdno %d too high", s);
429 	if (fdcon[s].c_status)
430 		fatal("conalloc: attempt to reuse fdno %d", s);
431 
432 	fdcon[s].c_fd = s;
433 	fdcon[s].c_status = CS_CON;
434 	fdcon[s].c_namebase = namebase;
435 	fdcon[s].c_name = name;
436 	fdcon[s].c_namelist = namelist;
437 	fdcon[s].c_output_name = xstrdup(oname);
438 	fdcon[s].c_data = (char *) &fdcon[s].c_plen;
439 	fdcon[s].c_len = 4;
440 	fdcon[s].c_off = 0;
441 	fdcon[s].c_keytype = keytype;
442 	gettimeofday(&fdcon[s].c_tv, NULL);
443 	fdcon[s].c_tv.tv_sec += timeout;
444 	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
445 	FD_SET(s, read_wait);
446 	ncon++;
447 	return (s);
448 }
449 
450 static void
451 confree(int s)
452 {
453 	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
454 		fatal("confree: attempt to free bad fdno %d", s);
455 	close(s);
456 	xfree(fdcon[s].c_namebase);
457 	xfree(fdcon[s].c_output_name);
458 	if (fdcon[s].c_status == CS_KEYS)
459 		xfree(fdcon[s].c_data);
460 	fdcon[s].c_status = CS_UNUSED;
461 	fdcon[s].c_keytype = 0;
462 	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
463 	FD_CLR(s, read_wait);
464 	ncon--;
465 }
466 
467 static void
468 contouch(int s)
469 {
470 	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
471 	gettimeofday(&fdcon[s].c_tv, NULL);
472 	fdcon[s].c_tv.tv_sec += timeout;
473 	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
474 }
475 
476 static int
477 conrecycle(int s)
478 {
479 	int ret;
480 	con *c = &fdcon[s];
481 
482 	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
483 	confree(s);
484 	return (ret);
485 }
486 
487 static void
488 congreet(int s)
489 {
490 	char buf[256], *cp;
491 	char remote_version[sizeof buf];
492 	size_t bufsiz;
493 	int remote_major, remote_minor, n = 0;
494 	con *c = &fdcon[s];
495 
496 	bufsiz = sizeof(buf);
497 	cp = buf;
498 	while (bufsiz-- && (n = read(s, cp, 1)) == 1 && *cp != '\n') {
499 		if (*cp == '\r')
500 			*cp = '\n';
501 		cp++;
502 	}
503 	if (n < 0) {
504 		if (errno != ECONNREFUSED)
505 			error("read (%s): %s", c->c_name, strerror(errno));
506 		conrecycle(s);
507 		return;
508 	}
509 	if (n == 0) {
510 		error("%s: Connection closed by remote host", c->c_name);
511 		conrecycle(s);
512 		return;
513 	}
514 	if (*cp != '\n' && *cp != '\r') {
515 		error("%s: bad greeting", c->c_name);
516 		confree(s);
517 		return;
518 	}
519 	*cp = '\0';
520 	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
521 	    &remote_major, &remote_minor, remote_version) == 3)
522 		compat_datafellows(remote_version);
523 	else
524 		datafellows = 0;
525 	if (c->c_keytype != KT_RSA1) {
526 		if (!ssh2_capable(remote_major, remote_minor)) {
527 			debug("%s doesn't support ssh2", c->c_name);
528 			confree(s);
529 			return;
530 		}
531 	} else if (remote_major != 1) {
532 		debug("%s doesn't support ssh1", c->c_name);
533 		confree(s);
534 		return;
535 	}
536 	fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
537 	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
538 	    c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
539 	    c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
540 	if (atomicio(write, s, buf, n) != n) {
541 		error("write (%s): %s", c->c_name, strerror(errno));
542 		confree(s);
543 		return;
544 	}
545 	if (c->c_keytype != KT_RSA1) {
546 		keyprint(c, keygrab_ssh2(c));
547 		confree(s);
548 		return;
549 	}
550 	c->c_status = CS_SIZE;
551 	contouch(s);
552 }
553 
554 static void
555 conread(int s)
556 {
557 	int n;
558 	con *c = &fdcon[s];
559 
560 	if (c->c_status == CS_CON) {
561 		congreet(s);
562 		return;
563 	}
564 	n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
565 	if (n < 0) {
566 		error("read (%s): %s", c->c_name, strerror(errno));
567 		confree(s);
568 		return;
569 	}
570 	c->c_off += n;
571 
572 	if (c->c_off == c->c_len)
573 		switch (c->c_status) {
574 		case CS_SIZE:
575 			c->c_plen = htonl(c->c_plen);
576 			c->c_len = c->c_plen + 8 - (c->c_plen & 7);
577 			c->c_off = 0;
578 			c->c_data = xmalloc(c->c_len);
579 			c->c_status = CS_KEYS;
580 			break;
581 		case CS_KEYS:
582 			keyprint(c, keygrab_ssh1(c));
583 			confree(s);
584 			return;
585 			break;
586 		default:
587 			fatal("conread: invalid status %d", c->c_status);
588 			break;
589 		}
590 
591 	contouch(s);
592 }
593 
594 static void
595 conloop(void)
596 {
597 	fd_set *r, *e;
598 	struct timeval seltime, now;
599 	int i;
600 	con *c;
601 
602 	gettimeofday(&now, NULL);
603 	c = TAILQ_FIRST(&tq);
604 
605 	if (c && (c->c_tv.tv_sec > now.tv_sec ||
606 	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
607 		seltime = c->c_tv;
608 		seltime.tv_sec -= now.tv_sec;
609 		seltime.tv_usec -= now.tv_usec;
610 		if (seltime.tv_usec < 0) {
611 			seltime.tv_usec += 1000000;
612 			seltime.tv_sec--;
613 		}
614 	} else
615 		seltime.tv_sec = seltime.tv_usec = 0;
616 
617 	r = xmalloc(read_wait_size);
618 	memcpy(r, read_wait, read_wait_size);
619 	e = xmalloc(read_wait_size);
620 	memcpy(e, read_wait, read_wait_size);
621 
622 	while (select(maxfd, r, NULL, e, &seltime) == -1 &&
623 	    (errno == EAGAIN || errno == EINTR))
624 		;
625 
626 	for (i = 0; i < maxfd; i++) {
627 		if (FD_ISSET(i, e)) {
628 			error("%s: exception!", fdcon[i].c_name);
629 			confree(i);
630 		} else if (FD_ISSET(i, r))
631 			conread(i);
632 	}
633 	xfree(r);
634 	xfree(e);
635 
636 	c = TAILQ_FIRST(&tq);
637 	while (c && (c->c_tv.tv_sec < now.tv_sec ||
638 	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
639 		int s = c->c_fd;
640 
641 		c = TAILQ_NEXT(c, c_link);
642 		conrecycle(s);
643 	}
644 }
645 
646 static void
647 do_host(char *host)
648 {
649 	char *name = strnnsep(&host, " \t\n");
650 	int j;
651 
652 	if (name == NULL)
653 		return;
654 	for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
655 		if (get_keytypes & j) {
656 			while (ncon >= MAXCON)
657 				conloop();
658 			conalloc(name, *host ? host : name, j);
659 		}
660 	}
661 }
662 
663 void
664 fatal(const char *fmt,...)
665 {
666 	va_list args;
667 	va_start(args, fmt);
668 	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
669 	va_end(args);
670 	if (nonfatal_fatal)
671 		longjmp(kexjmp, -1);
672 	else
673 		fatal_cleanup();
674 }
675 
676 static void
677 usage(void)
678 {
679 	fprintf(stderr, "Usage: %s [options] host ...\n",
680 	    __progname);
681 	fprintf(stderr, "Options:\n");
682 	fprintf(stderr, "  -f file     Read hosts or addresses from file.\n");
683 	fprintf(stderr, "  -p port     Connect to the specified port.\n");
684 	fprintf(stderr, "  -t keytype  Specify the host key type.\n");
685 	fprintf(stderr, "  -T timeout  Set connection timeout.\n");
686 	fprintf(stderr, "  -v          Verbose; display verbose debugging messages.\n");
687 	fprintf(stderr, "  -4          Use IPv4 only.\n");
688 	fprintf(stderr, "  -6          Use IPv6 only.\n");
689 	exit(1);
690 }
691 
692 int
693 main(int argc, char **argv)
694 {
695 	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
696 	int opt, fopt_count = 0;
697 	char *tname;
698 
699 	extern int optind;
700 	extern char *optarg;
701 
702 	__progname = get_progname(argv[0]);
703 	init_rng();
704 	seed_rng();
705 	TAILQ_INIT(&tq);
706 
707 	if (argc <= 1)
708 		usage();
709 
710 	while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
711 		switch (opt) {
712 		case 'p':
713 			ssh_port = a2port(optarg);
714 			if (ssh_port == 0) {
715 				fprintf(stderr, "Bad port '%s'\n", optarg);
716 				exit(1);
717 			}
718 			break;
719 		case 'T':
720 			timeout = atoi(optarg);
721 			if (timeout <= 0)
722 				usage();
723 			break;
724 		case 'v':
725 			if (!debug_flag) {
726 				debug_flag = 1;
727 				log_level = SYSLOG_LEVEL_DEBUG1;
728 			}
729 			else if (log_level < SYSLOG_LEVEL_DEBUG3)
730 				log_level++;
731 			else
732 				fatal("Too high debugging level.");
733 			break;
734 		case 'f':
735 			if (strcmp(optarg, "-") == 0)
736 				optarg = NULL;
737 			argv[fopt_count++] = optarg;
738 			break;
739 		case 't':
740 			get_keytypes = 0;
741 			tname = strtok(optarg, ",");
742 			while (tname) {
743 				int type = key_type_from_name(tname);
744 				switch (type) {
745 				case KEY_RSA1:
746 					get_keytypes |= KT_RSA1;
747 					break;
748 				case KEY_DSA:
749 					get_keytypes |= KT_DSA;
750 					break;
751 				case KEY_RSA:
752 					get_keytypes |= KT_RSA;
753 					break;
754 				case KEY_UNSPEC:
755 					fatal("unknown key type %s", tname);
756 				}
757 				tname = strtok(NULL, ",");
758 			}
759 			break;
760 		case '4':
761 			IPv4or6 = AF_INET;
762 			break;
763 		case '6':
764 			IPv4or6 = AF_INET6;
765 			break;
766 		case '?':
767 		default:
768 			usage();
769 		}
770 	}
771 	if (optind == argc && !fopt_count)
772 		usage();
773 
774 	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
775 
776 	maxfd = fdlim_get(1);
777 	if (maxfd < 0)
778 		fatal("%s: fdlim_get: bad value", __progname);
779 	if (maxfd > MAXMAXFD)
780 		maxfd = MAXMAXFD;
781 	if (MAXCON <= 0)
782 		fatal("%s: not enough file descriptors", __progname);
783 	if (maxfd > fdlim_get(0))
784 		fdlim_set(maxfd);
785 	fdcon = xmalloc(maxfd * sizeof(con));
786 	memset(fdcon, 0, maxfd * sizeof(con));
787 
788 	read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
789 	read_wait = xmalloc(read_wait_size);
790 	memset(read_wait, 0, read_wait_size);
791 
792 	if (fopt_count) {
793 		Linebuf *lb;
794 		char *line;
795 		int j;
796 
797 		for (j = 0; j < fopt_count; j++) {
798 			lb = Linebuf_alloc(argv[j], error);
799 			if (!lb)
800 				continue;
801 			while ((line = Linebuf_getline(lb)) != NULL)
802 				do_host(line);
803 			Linebuf_free(lb);
804 		}
805 	}
806 
807 	while (optind < argc)
808 		do_host(argv[optind++]);
809 
810 	while (ncon > 0)
811 		conloop();
812 
813 	return (0);
814 }
815