xref: /openbsd-src/usr.bin/ssh/ssh-keyscan.c (revision 7bbe964f6b7d22ad07ca46292495604f942eba4e)
1 /* $OpenBSD: ssh-keyscan.c,v 1.79 2009/10/28 16:38:18 reyk 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 <sys/types.h>
11 #include <sys/socket.h>
12 #include <sys/queue.h>
13 #include <sys/time.h>
14 #include <sys/resource.h>
15 
16 #include <openssl/bn.h>
17 
18 #include <errno.h>
19 #include <netdb.h>
20 #include <setjmp.h>
21 #include <stdarg.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <signal.h>
25 #include <string.h>
26 #include <unistd.h>
27 
28 #include "xmalloc.h"
29 #include "ssh.h"
30 #include "ssh1.h"
31 #include "buffer.h"
32 #include "key.h"
33 #include "cipher.h"
34 #include "kex.h"
35 #include "compat.h"
36 #include "myproposal.h"
37 #include "packet.h"
38 #include "dispatch.h"
39 #include "log.h"
40 #include "atomicio.h"
41 #include "misc.h"
42 #include "hostfile.h"
43 
44 /* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
45    Default value is AF_UNSPEC means both IPv4 and IPv6. */
46 int IPv4or6 = AF_UNSPEC;
47 
48 int ssh_port = SSH_DEFAULT_PORT;
49 
50 #define KT_RSA1	1
51 #define KT_DSA	2
52 #define KT_RSA	4
53 
54 int get_keytypes = KT_RSA;	/* Get only RSA keys by default */
55 
56 int hash_hosts = 0;		/* Hash hostname on output */
57 
58 #define MAXMAXFD 256
59 
60 /* The number of seconds after which to give up on a TCP connection */
61 int timeout = 5;
62 
63 int maxfd;
64 #define MAXCON (maxfd - 10)
65 
66 /* The default routing domain */
67 int scan_rdomain = -1;
68 
69 extern char *__progname;
70 fd_set *read_wait;
71 size_t read_wait_nfdset;
72 int ncon;
73 int nonfatal_fatal = 0;
74 jmp_buf kexjmp;
75 Key *kexjmp_key;
76 
77 /*
78  * Keep a connection structure for each file descriptor.  The state
79  * associated with file descriptor n is held in fdcon[n].
80  */
81 typedef struct Connection {
82 	u_char c_status;	/* State of connection on this file desc. */
83 #define CS_UNUSED 0		/* File descriptor unused */
84 #define CS_CON 1		/* Waiting to connect/read greeting */
85 #define CS_SIZE 2		/* Waiting to read initial packet size */
86 #define CS_KEYS 3		/* Waiting to read public key packet */
87 	int c_fd;		/* Quick lookup: c->c_fd == c - fdcon */
88 	int c_plen;		/* Packet length field for ssh packet */
89 	int c_len;		/* Total bytes which must be read. */
90 	int c_off;		/* Length of data read so far. */
91 	int c_keytype;		/* Only one of KT_RSA1, KT_DSA, or KT_RSA */
92 	char *c_namebase;	/* Address to free for c_name and c_namelist */
93 	char *c_name;		/* Hostname of connection for errors */
94 	char *c_namelist;	/* Pointer to other possible addresses */
95 	char *c_output_name;	/* Hostname of connection for output */
96 	char *c_data;		/* Data read from this fd */
97 	Kex *c_kex;		/* The key-exchange struct for ssh2 */
98 	struct timeval c_tv;	/* Time at which connection gets aborted */
99 	TAILQ_ENTRY(Connection) c_link;	/* List of connections in timeout order. */
100 } con;
101 
102 TAILQ_HEAD(conlist, Connection) tq;	/* Timeout Queue */
103 con *fdcon;
104 
105 /*
106  *  This is just a wrapper around fgets() to make it usable.
107  */
108 
109 /* Stress-test.  Increase this later. */
110 #define LINEBUF_SIZE 16
111 
112 typedef struct {
113 	char *buf;
114 	u_int size;
115 	int lineno;
116 	const char *filename;
117 	FILE *stream;
118 	void (*errfun) (const char *,...);
119 } Linebuf;
120 
121 static Linebuf *
122 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
123 {
124 	Linebuf *lb;
125 
126 	if (!(lb = malloc(sizeof(*lb)))) {
127 		if (errfun)
128 			(*errfun) ("linebuf (%s): malloc failed\n",
129 			    filename ? filename : "(stdin)");
130 		return (NULL);
131 	}
132 	if (filename) {
133 		lb->filename = filename;
134 		if (!(lb->stream = fopen(filename, "r"))) {
135 			xfree(lb);
136 			if (errfun)
137 				(*errfun) ("%s: %s\n", filename, strerror(errno));
138 			return (NULL);
139 		}
140 	} else {
141 		lb->filename = "(stdin)";
142 		lb->stream = stdin;
143 	}
144 
145 	if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
146 		if (errfun)
147 			(*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
148 		xfree(lb);
149 		return (NULL);
150 	}
151 	lb->errfun = errfun;
152 	lb->lineno = 0;
153 	return (lb);
154 }
155 
156 static void
157 Linebuf_free(Linebuf * lb)
158 {
159 	fclose(lb->stream);
160 	xfree(lb->buf);
161 	xfree(lb);
162 }
163 
164 #if 0
165 static void
166 Linebuf_restart(Linebuf * lb)
167 {
168 	clearerr(lb->stream);
169 	rewind(lb->stream);
170 	lb->lineno = 0;
171 }
172 
173 static int
174 Linebuf_lineno(Linebuf * lb)
175 {
176 	return (lb->lineno);
177 }
178 #endif
179 
180 static char *
181 Linebuf_getline(Linebuf * lb)
182 {
183 	size_t n = 0;
184 	void *p;
185 
186 	lb->lineno++;
187 	for (;;) {
188 		/* Read a line */
189 		if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
190 			if (ferror(lb->stream) && lb->errfun)
191 				(*lb->errfun)("%s: %s\n", lb->filename,
192 				    strerror(errno));
193 			return (NULL);
194 		}
195 		n = strlen(lb->buf);
196 
197 		/* Return it or an error if it fits */
198 		if (n > 0 && lb->buf[n - 1] == '\n') {
199 			lb->buf[n - 1] = '\0';
200 			return (lb->buf);
201 		}
202 		if (n != lb->size - 1) {
203 			if (lb->errfun)
204 				(*lb->errfun)("%s: skipping incomplete last line\n",
205 				    lb->filename);
206 			return (NULL);
207 		}
208 		/* Double the buffer if we need more space */
209 		lb->size *= 2;
210 		if ((p = realloc(lb->buf, lb->size)) == NULL) {
211 			lb->size /= 2;
212 			if (lb->errfun)
213 				(*lb->errfun)("linebuf (%s): realloc failed\n",
214 				    lb->filename);
215 			return (NULL);
216 		}
217 		lb->buf = p;
218 	}
219 }
220 
221 static int
222 fdlim_get(int hard)
223 {
224 	struct rlimit rlfd;
225 
226 	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
227 		return (-1);
228 	if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
229 		return sysconf(_SC_OPEN_MAX);
230 	else
231 		return hard ? rlfd.rlim_max : rlfd.rlim_cur;
232 }
233 
234 static int
235 fdlim_set(int lim)
236 {
237 	struct rlimit rlfd;
238 
239 	if (lim <= 0)
240 		return (-1);
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 	return (0);
247 }
248 
249 /*
250  * This is an strsep function that returns a null field for adjacent
251  * separators.  This is the same as the 4.4BSD strsep, but different from the
252  * one in the GNU libc.
253  */
254 static char *
255 xstrsep(char **str, const char *delim)
256 {
257 	char *s, *e;
258 
259 	if (!**str)
260 		return (NULL);
261 
262 	s = *str;
263 	e = s + strcspn(s, delim);
264 
265 	if (*e != '\0')
266 		*e++ = '\0';
267 	*str = e;
268 
269 	return (s);
270 }
271 
272 /*
273  * Get the next non-null token (like GNU strsep).  Strsep() will return a
274  * null token for two adjacent separators, so we may have to loop.
275  */
276 static char *
277 strnnsep(char **stringp, char *delim)
278 {
279 	char *tok;
280 
281 	do {
282 		tok = xstrsep(stringp, delim);
283 	} while (tok && *tok == '\0');
284 	return (tok);
285 }
286 
287 static Key *
288 keygrab_ssh1(con *c)
289 {
290 	static Key *rsa;
291 	static Buffer msg;
292 
293 	if (rsa == NULL) {
294 		buffer_init(&msg);
295 		rsa = key_new(KEY_RSA1);
296 	}
297 	buffer_append(&msg, c->c_data, c->c_plen);
298 	buffer_consume(&msg, 8 - (c->c_plen & 7));	/* padding */
299 	if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
300 		error("%s: invalid packet type", c->c_name);
301 		buffer_clear(&msg);
302 		return NULL;
303 	}
304 	buffer_consume(&msg, 8);		/* cookie */
305 
306 	/* server key */
307 	(void) buffer_get_int(&msg);
308 	buffer_get_bignum(&msg, rsa->rsa->e);
309 	buffer_get_bignum(&msg, rsa->rsa->n);
310 
311 	/* host key */
312 	(void) buffer_get_int(&msg);
313 	buffer_get_bignum(&msg, rsa->rsa->e);
314 	buffer_get_bignum(&msg, rsa->rsa->n);
315 
316 	buffer_clear(&msg);
317 
318 	return (rsa);
319 }
320 
321 static int
322 hostjump(Key *hostkey)
323 {
324 	kexjmp_key = hostkey;
325 	longjmp(kexjmp, 1);
326 }
327 
328 static int
329 ssh2_capable(int remote_major, int remote_minor)
330 {
331 	switch (remote_major) {
332 	case 1:
333 		if (remote_minor == 99)
334 			return 1;
335 		break;
336 	case 2:
337 		return 1;
338 	default:
339 		break;
340 	}
341 	return 0;
342 }
343 
344 static Key *
345 keygrab_ssh2(con *c)
346 {
347 	int j;
348 
349 	packet_set_connection(c->c_fd, c->c_fd);
350 	enable_compat20();
351 	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
352 	    "ssh-dss": "ssh-rsa";
353 	c->c_kex = kex_setup(myproposal);
354 	c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
355 	c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
356 	c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
357 	c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
358 	c->c_kex->verify_host_key = hostjump;
359 
360 	if (!(j = setjmp(kexjmp))) {
361 		nonfatal_fatal = 1;
362 		dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
363 		fprintf(stderr, "Impossible! dispatch_run() returned!\n");
364 		exit(1);
365 	}
366 	nonfatal_fatal = 0;
367 	xfree(c->c_kex);
368 	c->c_kex = NULL;
369 	packet_close();
370 
371 	return j < 0? NULL : kexjmp_key;
372 }
373 
374 static void
375 keyprint(con *c, Key *key)
376 {
377 	char *host = c->c_output_name ? c->c_output_name : c->c_name;
378 
379 	if (!key)
380 		return;
381 	if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
382 		fatal("host_hash failed");
383 
384 	fprintf(stdout, "%s ", host);
385 	key_write(key, stdout);
386 	fputs("\n", stdout);
387 }
388 
389 static int
390 tcpconnect(char *host)
391 {
392 	struct addrinfo hints, *ai, *aitop;
393 	char strport[NI_MAXSERV];
394 	int gaierr, s = -1;
395 
396 	snprintf(strport, sizeof strport, "%d", ssh_port);
397 	memset(&hints, 0, sizeof(hints));
398 	hints.ai_family = IPv4or6;
399 	hints.ai_socktype = SOCK_STREAM;
400 	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
401 		fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
402 	for (ai = aitop; ai; ai = ai->ai_next) {
403 		s = socket_rdomain(ai->ai_family, ai->ai_socktype,
404 		    ai->ai_protocol, scan_rdomain);
405 		if (s < 0) {
406 			error("socket: %s", strerror(errno));
407 			continue;
408 		}
409 		if (set_nonblock(s) == -1)
410 			fatal("%s: set_nonblock(%d)", __func__, s);
411 		if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
412 		    errno != EINPROGRESS)
413 			error("connect (`%s'): %s", host, strerror(errno));
414 		else
415 			break;
416 		close(s);
417 		s = -1;
418 	}
419 	freeaddrinfo(aitop);
420 	return s;
421 }
422 
423 static int
424 conalloc(char *iname, char *oname, int keytype)
425 {
426 	char *namebase, *name, *namelist;
427 	int s;
428 
429 	namebase = namelist = xstrdup(iname);
430 
431 	do {
432 		name = xstrsep(&namelist, ",");
433 		if (!name) {
434 			xfree(namebase);
435 			return (-1);
436 		}
437 	} while ((s = tcpconnect(name)) < 0);
438 
439 	if (s >= maxfd)
440 		fatal("conalloc: fdno %d too high", s);
441 	if (fdcon[s].c_status)
442 		fatal("conalloc: attempt to reuse fdno %d", s);
443 
444 	fdcon[s].c_fd = s;
445 	fdcon[s].c_status = CS_CON;
446 	fdcon[s].c_namebase = namebase;
447 	fdcon[s].c_name = name;
448 	fdcon[s].c_namelist = namelist;
449 	fdcon[s].c_output_name = xstrdup(oname);
450 	fdcon[s].c_data = (char *) &fdcon[s].c_plen;
451 	fdcon[s].c_len = 4;
452 	fdcon[s].c_off = 0;
453 	fdcon[s].c_keytype = keytype;
454 	gettimeofday(&fdcon[s].c_tv, NULL);
455 	fdcon[s].c_tv.tv_sec += timeout;
456 	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
457 	FD_SET(s, read_wait);
458 	ncon++;
459 	return (s);
460 }
461 
462 static void
463 confree(int s)
464 {
465 	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
466 		fatal("confree: attempt to free bad fdno %d", s);
467 	close(s);
468 	xfree(fdcon[s].c_namebase);
469 	xfree(fdcon[s].c_output_name);
470 	if (fdcon[s].c_status == CS_KEYS)
471 		xfree(fdcon[s].c_data);
472 	fdcon[s].c_status = CS_UNUSED;
473 	fdcon[s].c_keytype = 0;
474 	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
475 	FD_CLR(s, read_wait);
476 	ncon--;
477 }
478 
479 static void
480 contouch(int s)
481 {
482 	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
483 	gettimeofday(&fdcon[s].c_tv, NULL);
484 	fdcon[s].c_tv.tv_sec += timeout;
485 	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
486 }
487 
488 static int
489 conrecycle(int s)
490 {
491 	con *c = &fdcon[s];
492 	int ret;
493 
494 	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
495 	confree(s);
496 	return (ret);
497 }
498 
499 static void
500 congreet(int s)
501 {
502 	int n = 0, remote_major = 0, remote_minor = 0;
503 	char buf[256], *cp;
504 	char remote_version[sizeof buf];
505 	size_t bufsiz;
506 	con *c = &fdcon[s];
507 
508 	for (;;) {
509 		memset(buf, '\0', sizeof(buf));
510 		bufsiz = sizeof(buf);
511 		cp = buf;
512 		while (bufsiz-- &&
513 		    (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
514 			if (*cp == '\r')
515 				*cp = '\n';
516 			cp++;
517 		}
518 		if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
519 			break;
520 	}
521 	if (n == 0) {
522 		switch (errno) {
523 		case EPIPE:
524 			error("%s: Connection closed by remote host", c->c_name);
525 			break;
526 		case ECONNREFUSED:
527 			break;
528 		default:
529 			error("read (%s): %s", c->c_name, strerror(errno));
530 			break;
531 		}
532 		conrecycle(s);
533 		return;
534 	}
535 	if (*cp != '\n' && *cp != '\r') {
536 		error("%s: bad greeting", c->c_name);
537 		confree(s);
538 		return;
539 	}
540 	*cp = '\0';
541 	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
542 	    &remote_major, &remote_minor, remote_version) == 3)
543 		compat_datafellows(remote_version);
544 	else
545 		datafellows = 0;
546 	if (c->c_keytype != KT_RSA1) {
547 		if (!ssh2_capable(remote_major, remote_minor)) {
548 			debug("%s doesn't support ssh2", c->c_name);
549 			confree(s);
550 			return;
551 		}
552 	} else if (remote_major != 1) {
553 		debug("%s doesn't support ssh1", c->c_name);
554 		confree(s);
555 		return;
556 	}
557 	fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
558 	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
559 	    c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
560 	    c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
561 	if (n < 0 || (size_t)n >= sizeof(buf)) {
562 		error("snprintf: buffer too small");
563 		confree(s);
564 		return;
565 	}
566 	if (atomicio(vwrite, s, buf, n) != (size_t)n) {
567 		error("write (%s): %s", c->c_name, strerror(errno));
568 		confree(s);
569 		return;
570 	}
571 	if (c->c_keytype != KT_RSA1) {
572 		keyprint(c, keygrab_ssh2(c));
573 		confree(s);
574 		return;
575 	}
576 	c->c_status = CS_SIZE;
577 	contouch(s);
578 }
579 
580 static void
581 conread(int s)
582 {
583 	con *c = &fdcon[s];
584 	size_t n;
585 
586 	if (c->c_status == CS_CON) {
587 		congreet(s);
588 		return;
589 	}
590 	n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
591 	if (n == 0) {
592 		error("read (%s): %s", c->c_name, strerror(errno));
593 		confree(s);
594 		return;
595 	}
596 	c->c_off += n;
597 
598 	if (c->c_off == c->c_len)
599 		switch (c->c_status) {
600 		case CS_SIZE:
601 			c->c_plen = htonl(c->c_plen);
602 			c->c_len = c->c_plen + 8 - (c->c_plen & 7);
603 			c->c_off = 0;
604 			c->c_data = xmalloc(c->c_len);
605 			c->c_status = CS_KEYS;
606 			break;
607 		case CS_KEYS:
608 			keyprint(c, keygrab_ssh1(c));
609 			confree(s);
610 			return;
611 		default:
612 			fatal("conread: invalid status %d", c->c_status);
613 			break;
614 		}
615 
616 	contouch(s);
617 }
618 
619 static void
620 conloop(void)
621 {
622 	struct timeval seltime, now;
623 	fd_set *r, *e;
624 	con *c;
625 	int i;
626 
627 	gettimeofday(&now, NULL);
628 	c = TAILQ_FIRST(&tq);
629 
630 	if (c && (c->c_tv.tv_sec > now.tv_sec ||
631 	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
632 		seltime = c->c_tv;
633 		seltime.tv_sec -= now.tv_sec;
634 		seltime.tv_usec -= now.tv_usec;
635 		if (seltime.tv_usec < 0) {
636 			seltime.tv_usec += 1000000;
637 			seltime.tv_sec--;
638 		}
639 	} else
640 		seltime.tv_sec = seltime.tv_usec = 0;
641 
642 	r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
643 	e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
644 	memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
645 	memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
646 
647 	while (select(maxfd, r, NULL, e, &seltime) == -1 &&
648 	    (errno == EAGAIN || errno == EINTR))
649 		;
650 
651 	for (i = 0; i < maxfd; i++) {
652 		if (FD_ISSET(i, e)) {
653 			error("%s: exception!", fdcon[i].c_name);
654 			confree(i);
655 		} else if (FD_ISSET(i, r))
656 			conread(i);
657 	}
658 	xfree(r);
659 	xfree(e);
660 
661 	c = TAILQ_FIRST(&tq);
662 	while (c && (c->c_tv.tv_sec < now.tv_sec ||
663 	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
664 		int s = c->c_fd;
665 
666 		c = TAILQ_NEXT(c, c_link);
667 		conrecycle(s);
668 	}
669 }
670 
671 static void
672 do_host(char *host)
673 {
674 	char *name = strnnsep(&host, " \t\n");
675 	int j;
676 
677 	if (name == NULL)
678 		return;
679 	for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
680 		if (get_keytypes & j) {
681 			while (ncon >= MAXCON)
682 				conloop();
683 			conalloc(name, *host ? host : name, j);
684 		}
685 	}
686 }
687 
688 void
689 fatal(const char *fmt,...)
690 {
691 	va_list args;
692 
693 	va_start(args, fmt);
694 	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
695 	va_end(args);
696 	if (nonfatal_fatal)
697 		longjmp(kexjmp, -1);
698 	else
699 		exit(255);
700 }
701 
702 static void
703 usage(void)
704 {
705 	fprintf(stderr,
706 	    "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
707 	    "\t\t   [-V rdomain] [host | addrlist namelist] ...\n",
708 	    __progname);
709 	exit(1);
710 }
711 
712 int
713 main(int argc, char **argv)
714 {
715 	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
716 	int opt, fopt_count = 0;
717 	char *tname;
718 
719 	extern int optind;
720 	extern char *optarg;
721 
722 	TAILQ_INIT(&tq);
723 
724 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
725 	sanitise_stdfd();
726 
727 	if (argc <= 1)
728 		usage();
729 
730 	while ((opt = getopt(argc, argv, "Hv46p:T:t:f:V:")) != -1) {
731 		switch (opt) {
732 		case 'H':
733 			hash_hosts = 1;
734 			break;
735 		case 'p':
736 			ssh_port = a2port(optarg);
737 			if (ssh_port <= 0) {
738 				fprintf(stderr, "Bad port '%s'\n", optarg);
739 				exit(1);
740 			}
741 			break;
742 		case 'T':
743 			timeout = convtime(optarg);
744 			if (timeout == -1 || timeout == 0) {
745 				fprintf(stderr, "Bad timeout '%s'\n", optarg);
746 				usage();
747 			}
748 			break;
749 		case 'v':
750 			if (!debug_flag) {
751 				debug_flag = 1;
752 				log_level = SYSLOG_LEVEL_DEBUG1;
753 			}
754 			else if (log_level < SYSLOG_LEVEL_DEBUG3)
755 				log_level++;
756 			else
757 				fatal("Too high debugging level.");
758 			break;
759 		case 'f':
760 			if (strcmp(optarg, "-") == 0)
761 				optarg = NULL;
762 			argv[fopt_count++] = optarg;
763 			break;
764 		case 't':
765 			get_keytypes = 0;
766 			tname = strtok(optarg, ",");
767 			while (tname) {
768 				int type = key_type_from_name(tname);
769 				switch (type) {
770 				case KEY_RSA1:
771 					get_keytypes |= KT_RSA1;
772 					break;
773 				case KEY_DSA:
774 					get_keytypes |= KT_DSA;
775 					break;
776 				case KEY_RSA:
777 					get_keytypes |= KT_RSA;
778 					break;
779 				case KEY_UNSPEC:
780 					fatal("unknown key type %s", tname);
781 				}
782 				tname = strtok(NULL, ",");
783 			}
784 			break;
785 		case '4':
786 			IPv4or6 = AF_INET;
787 			break;
788 		case '6':
789 			IPv4or6 = AF_INET6;
790 			break;
791 		case 'V':
792 			scan_rdomain = a2port(optarg);
793 			if (scan_rdomain < 0)
794 				scan_rdomain = -1;
795 			break;
796 		case '?':
797 		default:
798 			usage();
799 		}
800 	}
801 	if (optind == argc && !fopt_count)
802 		usage();
803 
804 	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
805 
806 	maxfd = fdlim_get(1);
807 	if (maxfd < 0)
808 		fatal("%s: fdlim_get: bad value", __progname);
809 	if (maxfd > MAXMAXFD)
810 		maxfd = MAXMAXFD;
811 	if (MAXCON <= 0)
812 		fatal("%s: not enough file descriptors", __progname);
813 	if (maxfd > fdlim_get(0))
814 		fdlim_set(maxfd);
815 	fdcon = xcalloc(maxfd, sizeof(con));
816 
817 	read_wait_nfdset = howmany(maxfd, NFDBITS);
818 	read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
819 
820 	if (fopt_count) {
821 		Linebuf *lb;
822 		char *line;
823 		int j;
824 
825 		for (j = 0; j < fopt_count; j++) {
826 			lb = Linebuf_alloc(argv[j], error);
827 			if (!lb)
828 				continue;
829 			while ((line = Linebuf_getline(lb)) != NULL)
830 				do_host(line);
831 			Linebuf_free(lb);
832 		}
833 	}
834 
835 	while (optind < argc)
836 		do_host(argv[optind++]);
837 
838 	while (ncon > 0)
839 		conloop();
840 
841 	return (0);
842 }
843