ssh-keyscan.c revision 106130 
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"
10RCSID("$OpenBSD: ssh-keyscan.c,v 1.40 2002/07/06 17:47:58 stevesk Exp $");
11RCSID("$FreeBSD: head/crypto/openssh/ssh-keyscan.c 106130 2002-10-29 10:16:02Z des $");
12
13#include "openbsd-compat/sys-queue.h"
14
15#include <openssl/bn.h>
16
17#include <setjmp.h>
18#include "xmalloc.h"
19#include "ssh.h"
20#include "ssh1.h"
21#include "key.h"
22#include "kex.h"
23#include "compat.h"
24#include "myproposal.h"
25#include "packet.h"
26#include "dispatch.h"
27#include "buffer.h"
28#include "bufaux.h"
29#include "log.h"
30#include "atomicio.h"
31#include "misc.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#ifdef IPV4_DEFAULT
36int IPv4or6 = AF_INET;
37#else
38int IPv4or6 = AF_UNSPEC;
39#endif
40
41int ssh_port = SSH_DEFAULT_PORT;
42
43#define KT_RSA1	1
44#define KT_DSA	2
45#define KT_RSA	4
46
47int get_keytypes = KT_RSA1;	/* Get only RSA1 keys by default */
48
49#define MAXMAXFD 256
50
51/* The number of seconds after which to give up on a TCP connection */
52int timeout = 5;
53
54int maxfd;
55#define MAXCON (maxfd - 10)
56
57#ifdef HAVE___PROGNAME
58extern char *__progname;
59#else
60char *__progname;
61#endif
62fd_set *read_wait;
63size_t read_wait_size;
64int ncon;
65int nonfatal_fatal = 0;
66jmp_buf kexjmp;
67Key *kexjmp_key;
68
69/*
70 * Keep a connection structure for each file descriptor.  The state
71 * associated with file descriptor n is held in fdcon[n].
72 */
73typedef struct Connection {
74	u_char c_status;	/* State of connection on this file desc. */
75#define CS_UNUSED 0		/* File descriptor unused */
76#define CS_CON 1		/* Waiting to connect/read greeting */
77#define CS_SIZE 2		/* Waiting to read initial packet size */
78#define CS_KEYS 3		/* Waiting to read public key packet */
79	int c_fd;		/* Quick lookup: c->c_fd == c - fdcon */
80	int c_plen;		/* Packet length field for ssh packet */
81	int c_len;		/* Total bytes which must be read. */
82	int c_off;		/* Length of data read so far. */
83	int c_keytype;		/* Only one of KT_RSA1, KT_DSA, or KT_RSA */
84	char *c_namebase;	/* Address to free for c_name and c_namelist */
85	char *c_name;		/* Hostname of connection for errors */
86	char *c_namelist;	/* Pointer to other possible addresses */
87	char *c_output_name;	/* Hostname of connection for output */
88	char *c_data;		/* Data read from this fd */
89	Kex *c_kex;		/* The key-exchange struct for ssh2 */
90	struct timeval c_tv;	/* Time at which connection gets aborted */
91	TAILQ_ENTRY(Connection) c_link;	/* List of connections in timeout order. */
92} con;
93
94TAILQ_HEAD(conlist, Connection) tq;	/* Timeout Queue */
95con *fdcon;
96
97/*
98 *  This is just a wrapper around fgets() to make it usable.
99 */
100
101/* Stress-test.  Increase this later. */
102#define LINEBUF_SIZE 16
103
104typedef struct {
105	char *buf;
106	u_int size;
107	int lineno;
108	const char *filename;
109	FILE *stream;
110	void (*errfun) (const char *,...);
111} Linebuf;
112
113static Linebuf *
114Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
115{
116	Linebuf *lb;
117
118	if (!(lb = malloc(sizeof(*lb)))) {
119		if (errfun)
120			(*errfun) ("linebuf (%s): malloc failed\n",
121			    filename ? filename : "(stdin)");
122		return (NULL);
123	}
124	if (filename) {
125		lb->filename = filename;
126		if (!(lb->stream = fopen(filename, "r"))) {
127			xfree(lb);
128			if (errfun)
129				(*errfun) ("%s: %s\n", filename, strerror(errno));
130			return (NULL);
131		}
132	} else {
133		lb->filename = "(stdin)";
134		lb->stream = stdin;
135	}
136
137	if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
138		if (errfun)
139			(*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
140		xfree(lb);
141		return (NULL);
142	}
143	lb->errfun = errfun;
144	lb->lineno = 0;
145	return (lb);
146}
147
148static void
149Linebuf_free(Linebuf * lb)
150{
151	fclose(lb->stream);
152	xfree(lb->buf);
153	xfree(lb);
154}
155
156#if 0
157static void
158Linebuf_restart(Linebuf * lb)
159{
160	clearerr(lb->stream);
161	rewind(lb->stream);
162	lb->lineno = 0;
163}
164
165static int
166Linebuf_lineno(Linebuf * lb)
167{
168	return (lb->lineno);
169}
170#endif
171
172static char *
173Linebuf_getline(Linebuf * lb)
174{
175	int n = 0;
176	void *p;
177
178	lb->lineno++;
179	for (;;) {
180		/* Read a line */
181		if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
182			if (ferror(lb->stream) && lb->errfun)
183				(*lb->errfun)("%s: %s\n", lb->filename,
184				    strerror(errno));
185			return (NULL);
186		}
187		n = strlen(lb->buf);
188
189		/* Return it or an error if it fits */
190		if (n > 0 && lb->buf[n - 1] == '\n') {
191			lb->buf[n - 1] = '\0';
192			return (lb->buf);
193		}
194		if (n != lb->size - 1) {
195			if (lb->errfun)
196				(*lb->errfun)("%s: skipping incomplete last line\n",
197				    lb->filename);
198			return (NULL);
199		}
200		/* Double the buffer if we need more space */
201		lb->size *= 2;
202		if ((p = realloc(lb->buf, lb->size)) == NULL) {
203			lb->size /= 2;
204			if (lb->errfun)
205				(*lb->errfun)("linebuf (%s): realloc failed\n",
206				    lb->filename);
207			return (NULL);
208		}
209		lb->buf = p;
210	}
211}
212
213static int
214fdlim_get(int hard)
215{
216#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
217	struct rlimit rlfd;
218
219	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
220		return (-1);
221	if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
222		return 10000;
223	else
224		return hard ? rlfd.rlim_max : rlfd.rlim_cur;
225#elif defined (HAVE_SYSCONF)
226	return sysconf (_SC_OPEN_MAX);
227#else
228	return 10000;
229#endif
230}
231
232static int
233fdlim_set(int lim)
234{
235#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
236	struct rlimit rlfd;
237#endif
238
239	if (lim <= 0)
240		return (-1);
241#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
242	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
243		return (-1);
244	rlfd.rlim_cur = lim;
245	if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
246		return (-1);
247#elif defined (HAVE_SETDTABLESIZE)
248	setdtablesize(lim);
249#endif
250	return (0);
251}
252
253/*
254 * This is an strsep function that returns a null field for adjacent
255 * separators.  This is the same as the 4.4BSD strsep, but different from the
256 * one in the GNU libc.
257 */
258static char *
259xstrsep(char **str, const char *delim)
260{
261	char *s, *e;
262
263	if (!**str)
264		return (NULL);
265
266	s = *str;
267	e = s + strcspn(s, delim);
268
269	if (*e != '\0')
270		*e++ = '\0';
271	*str = e;
272
273	return (s);
274}
275
276/*
277 * Get the next non-null token (like GNU strsep).  Strsep() will return a
278 * null token for two adjacent separators, so we may have to loop.
279 */
280static char *
281strnnsep(char **stringp, char *delim)
282{
283	char *tok;
284
285	do {
286		tok = xstrsep(stringp, delim);
287	} while (tok && *tok == '\0');
288	return (tok);
289}
290
291static Key *
292keygrab_ssh1(con *c)
293{
294	static Key *rsa;
295	static Buffer msg;
296
297	if (rsa == NULL) {
298		buffer_init(&msg);
299		rsa = key_new(KEY_RSA1);
300	}
301	buffer_append(&msg, c->c_data, c->c_plen);
302	buffer_consume(&msg, 8 - (c->c_plen & 7));	/* padding */
303	if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
304		error("%s: invalid packet type", c->c_name);
305		buffer_clear(&msg);
306		return NULL;
307	}
308	buffer_consume(&msg, 8);		/* cookie */
309
310	/* server key */
311	(void) buffer_get_int(&msg);
312	buffer_get_bignum(&msg, rsa->rsa->e);
313	buffer_get_bignum(&msg, rsa->rsa->n);
314
315	/* host key */
316	(void) buffer_get_int(&msg);
317	buffer_get_bignum(&msg, rsa->rsa->e);
318	buffer_get_bignum(&msg, rsa->rsa->n);
319
320	buffer_clear(&msg);
321
322	return (rsa);
323}
324
325static int
326hostjump(Key *hostkey)
327{
328	kexjmp_key = hostkey;
329	longjmp(kexjmp, 1);
330}
331
332static int
333ssh2_capable(int remote_major, int remote_minor)
334{
335	switch (remote_major) {
336	case 1:
337		if (remote_minor == 99)
338			return 1;
339		break;
340	case 2:
341		return 1;
342	default:
343		break;
344	}
345	return 0;
346}
347
348static Key *
349keygrab_ssh2(con *c)
350{
351	int j;
352
353	packet_set_connection(c->c_fd, c->c_fd);
354	enable_compat20();
355	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
356	    "ssh-dss": "ssh-rsa";
357	c->c_kex = kex_setup(myproposal);
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
374static void
375keyprint(con *c, Key *key)
376{
377	if (!key)
378		return;
379
380	fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
381	key_write(key, stdout);
382	fputs("\n", stdout);
383}
384
385static int
386tcpconnect(char *host)
387{
388	struct addrinfo hints, *ai, *aitop;
389	char strport[NI_MAXSERV];
390	int gaierr, s = -1;
391
392	snprintf(strport, sizeof strport, "%d", ssh_port);
393	memset(&hints, 0, sizeof(hints));
394	hints.ai_family = IPv4or6;
395	hints.ai_socktype = SOCK_STREAM;
396	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
397		fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
398	for (ai = aitop; ai; ai = ai->ai_next) {
399		s = socket(ai->ai_family, SOCK_STREAM, 0);
400		if (s < 0) {
401			error("socket: %s", strerror(errno));
402			continue;
403		}
404		if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
405			fatal("F_SETFL: %s", strerror(errno));
406		if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
407		    errno != EINPROGRESS)
408			error("connect (`%s'): %s", host, strerror(errno));
409		else
410			break;
411		close(s);
412		s = -1;
413	}
414	freeaddrinfo(aitop);
415	return s;
416}
417
418static int
419conalloc(char *iname, char *oname, int keytype)
420{
421	char *namebase, *name, *namelist;
422	int s;
423
424	namebase = namelist = xstrdup(iname);
425
426	do {
427		name = xstrsep(&namelist, ",");
428		if (!name) {
429			xfree(namebase);
430			return (-1);
431		}
432	} while ((s = tcpconnect(name)) < 0);
433
434	if (s >= maxfd)
435		fatal("conalloc: fdno %d too high", s);
436	if (fdcon[s].c_status)
437		fatal("conalloc: attempt to reuse fdno %d", s);
438
439	fdcon[s].c_fd = s;
440	fdcon[s].c_status = CS_CON;
441	fdcon[s].c_namebase = namebase;
442	fdcon[s].c_name = name;
443	fdcon[s].c_namelist = namelist;
444	fdcon[s].c_output_name = xstrdup(oname);
445	fdcon[s].c_data = (char *) &fdcon[s].c_plen;
446	fdcon[s].c_len = 4;
447	fdcon[s].c_off = 0;
448	fdcon[s].c_keytype = keytype;
449	gettimeofday(&fdcon[s].c_tv, NULL);
450	fdcon[s].c_tv.tv_sec += timeout;
451	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
452	FD_SET(s, read_wait);
453	ncon++;
454	return (s);
455}
456
457static void
458confree(int s)
459{
460	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
461		fatal("confree: attempt to free bad fdno %d", s);
462	close(s);
463	xfree(fdcon[s].c_namebase);
464	xfree(fdcon[s].c_output_name);
465	if (fdcon[s].c_status == CS_KEYS)
466		xfree(fdcon[s].c_data);
467	fdcon[s].c_status = CS_UNUSED;
468	fdcon[s].c_keytype = 0;
469	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
470	FD_CLR(s, read_wait);
471	ncon--;
472}
473
474static void
475contouch(int s)
476{
477	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
478	gettimeofday(&fdcon[s].c_tv, NULL);
479	fdcon[s].c_tv.tv_sec += timeout;
480	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
481}
482
483static int
484conrecycle(int s)
485{
486	con *c = &fdcon[s];
487	int ret;
488
489	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
490	confree(s);
491	return (ret);
492}
493
494static void
495congreet(int s)
496{
497	int remote_major, remote_minor, n = 0;
498	char buf[256], *cp;
499	char remote_version[sizeof buf];
500	size_t bufsiz;
501	con *c = &fdcon[s];
502
503	bufsiz = sizeof(buf);
504	cp = buf;
505	while (bufsiz-- && (n = read(s, cp, 1)) == 1 && *cp != '\n') {
506		if (*cp == '\r')
507			*cp = '\n';
508		cp++;
509	}
510	if (n < 0) {
511		if (errno != ECONNREFUSED)
512			error("read (%s): %s", c->c_name, strerror(errno));
513		conrecycle(s);
514		return;
515	}
516	if (n == 0) {
517		error("%s: Connection closed by remote host", c->c_name);
518		conrecycle(s);
519		return;
520	}
521	if (*cp != '\n' && *cp != '\r') {
522		error("%s: bad greeting", c->c_name);
523		confree(s);
524		return;
525	}
526	*cp = '\0';
527	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
528	    &remote_major, &remote_minor, remote_version) == 3)
529		compat_datafellows(remote_version);
530	else
531		datafellows = 0;
532	if (c->c_keytype != KT_RSA1) {
533		if (!ssh2_capable(remote_major, remote_minor)) {
534			debug("%s doesn't support ssh2", c->c_name);
535			confree(s);
536			return;
537		}
538	} else if (remote_major != 1) {
539		debug("%s doesn't support ssh1", c->c_name);
540		confree(s);
541		return;
542	}
543	fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
544	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
545	    c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
546	    c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
547	if (atomicio(write, s, buf, n) != n) {
548		error("write (%s): %s", c->c_name, strerror(errno));
549		confree(s);
550		return;
551	}
552	if (c->c_keytype != KT_RSA1) {
553		keyprint(c, keygrab_ssh2(c));
554		confree(s);
555		return;
556	}
557	c->c_status = CS_SIZE;
558	contouch(s);
559}
560
561static void
562conread(int s)
563{
564	con *c = &fdcon[s];
565	int n;
566
567	if (c->c_status == CS_CON) {
568		congreet(s);
569		return;
570	}
571	n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
572	if (n < 0) {
573		error("read (%s): %s", c->c_name, strerror(errno));
574		confree(s);
575		return;
576	}
577	c->c_off += n;
578
579	if (c->c_off == c->c_len)
580		switch (c->c_status) {
581		case CS_SIZE:
582			c->c_plen = htonl(c->c_plen);
583			c->c_len = c->c_plen + 8 - (c->c_plen & 7);
584			c->c_off = 0;
585			c->c_data = xmalloc(c->c_len);
586			c->c_status = CS_KEYS;
587			break;
588		case CS_KEYS:
589			keyprint(c, keygrab_ssh1(c));
590			confree(s);
591			return;
592			break;
593		default:
594			fatal("conread: invalid status %d", c->c_status);
595			break;
596		}
597
598	contouch(s);
599}
600
601static void
602conloop(void)
603{
604	struct timeval seltime, now;
605	fd_set *r, *e;
606	con *c;
607	int i;
608
609	gettimeofday(&now, NULL);
610	c = TAILQ_FIRST(&tq);
611
612	if (c && (c->c_tv.tv_sec > now.tv_sec ||
613	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
614		seltime = c->c_tv;
615		seltime.tv_sec -= now.tv_sec;
616		seltime.tv_usec -= now.tv_usec;
617		if (seltime.tv_usec < 0) {
618			seltime.tv_usec += 1000000;
619			seltime.tv_sec--;
620		}
621	} else
622		seltime.tv_sec = seltime.tv_usec = 0;
623
624	r = xmalloc(read_wait_size);
625	memcpy(r, read_wait, read_wait_size);
626	e = xmalloc(read_wait_size);
627	memcpy(e, read_wait, read_wait_size);
628
629	while (select(maxfd, r, NULL, e, &seltime) == -1 &&
630	    (errno == EAGAIN || errno == EINTR))
631		;
632
633	for (i = 0; i < maxfd; i++) {
634		if (FD_ISSET(i, e)) {
635			error("%s: exception!", fdcon[i].c_name);
636			confree(i);
637		} else if (FD_ISSET(i, r))
638			conread(i);
639	}
640	xfree(r);
641	xfree(e);
642
643	c = TAILQ_FIRST(&tq);
644	while (c && (c->c_tv.tv_sec < now.tv_sec ||
645	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
646		int s = c->c_fd;
647
648		c = TAILQ_NEXT(c, c_link);
649		conrecycle(s);
650	}
651}
652
653static void
654do_host(char *host)
655{
656	char *name = strnnsep(&host, " \t\n");
657	int j;
658
659	if (name == NULL)
660		return;
661	for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
662		if (get_keytypes & j) {
663			while (ncon >= MAXCON)
664				conloop();
665			conalloc(name, *host ? host : name, j);
666		}
667	}
668}
669
670void
671fatal(const char *fmt,...)
672{
673	va_list args;
674
675	va_start(args, fmt);
676	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
677	va_end(args);
678	if (nonfatal_fatal)
679		longjmp(kexjmp, -1);
680	else
681		fatal_cleanup();
682}
683
684static void
685usage(void)
686{
687	fprintf(stderr, "usage: %s [-v46] [-p port] [-T timeout] [-f file]\n"
688	    "\t\t   [host | addrlist namelist] [...]\n",
689	    __progname);
690	exit(1);
691}
692
693int
694main(int argc, char **argv)
695{
696	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
697	int opt, fopt_count = 0;
698	char *tname;
699
700	extern int optind;
701	extern char *optarg;
702
703	__progname = get_progname(argv[0]);
704	init_rng();
705	seed_rng();
706	TAILQ_INIT(&tq);
707
708	if (argc <= 1)
709		usage();
710
711	while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
712		switch (opt) {
713		case 'p':
714			ssh_port = a2port(optarg);
715			if (ssh_port == 0) {
716				fprintf(stderr, "Bad port '%s'\n", optarg);
717				exit(1);
718			}
719			break;
720		case 'T':
721			timeout = convtime(optarg);
722			if (timeout == -1 || timeout == 0) {
723				fprintf(stderr, "Bad timeout '%s'\n", optarg);
724				usage();
725			}
726			break;
727		case 'v':
728			if (!debug_flag) {
729				debug_flag = 1;
730				log_level = SYSLOG_LEVEL_DEBUG1;
731			}
732			else if (log_level < SYSLOG_LEVEL_DEBUG3)
733				log_level++;
734			else
735				fatal("Too high debugging level.");
736			break;
737		case 'f':
738			if (strcmp(optarg, "-") == 0)
739				optarg = NULL;
740			argv[fopt_count++] = optarg;
741			break;
742		case 't':
743			get_keytypes = 0;
744			tname = strtok(optarg, ",");
745			while (tname) {
746				int type = key_type_from_name(tname);
747				switch (type) {
748				case KEY_RSA1:
749					get_keytypes |= KT_RSA1;
750					break;
751				case KEY_DSA:
752					get_keytypes |= KT_DSA;
753					break;
754				case KEY_RSA:
755					get_keytypes |= KT_RSA;
756					break;
757				case KEY_UNSPEC:
758					fatal("unknown key type %s", tname);
759				}
760				tname = strtok(NULL, ",");
761			}
762			break;
763		case '4':
764			IPv4or6 = AF_INET;
765			break;
766		case '6':
767			IPv4or6 = AF_INET6;
768			break;
769		case '?':
770		default:
771			usage();
772		}
773	}
774	if (optind == argc && !fopt_count)
775		usage();
776
777	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
778
779	maxfd = fdlim_get(1);
780	if (maxfd < 0)
781		fatal("%s: fdlim_get: bad value", __progname);
782	if (maxfd > MAXMAXFD)
783		maxfd = MAXMAXFD;
784	if (MAXCON <= 0)
785		fatal("%s: not enough file descriptors", __progname);
786	if (maxfd > fdlim_get(0))
787		fdlim_set(maxfd);
788	fdcon = xmalloc(maxfd * sizeof(con));
789	memset(fdcon, 0, maxfd * sizeof(con));
790
791	read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
792	read_wait = xmalloc(read_wait_size);
793	memset(read_wait, 0, read_wait_size);
794
795	if (fopt_count) {
796		Linebuf *lb;
797		char *line;
798		int j;
799
800		for (j = 0; j < fopt_count; j++) {
801			lb = Linebuf_alloc(argv[j], error);
802			if (!lb)
803				continue;
804			while ((line = Linebuf_getline(lb)) != NULL)
805				do_host(line);
806			Linebuf_free(lb);
807		}
808	}
809
810	while (optind < argc)
811		do_host(argv[optind++]);
812
813	while (ncon > 0)
814		conloop();
815
816	return (0);
817}
818