ssh-keyscan.c revision 128460 
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 1.47 2004/03/08 09:38:05 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
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. */
34int IPv4or6 = AF_UNSPEC;
35
36int ssh_port = SSH_DEFAULT_PORT;
37
38#define KT_RSA1	1
39#define KT_DSA	2
40#define KT_RSA	4
41
42int get_keytypes = KT_RSA1;	/* Get only RSA1 keys by default */
43
44#define MAXMAXFD 256
45
46/* The number of seconds after which to give up on a TCP connection */
47int timeout = 5;
48
49int maxfd;
50#define MAXCON (maxfd - 10)
51
52#ifdef HAVE___PROGNAME
53extern char *__progname;
54#else
55char *__progname;
56#endif
57fd_set *read_wait;
58size_t read_wait_size;
59int ncon;
60int nonfatal_fatal = 0;
61jmp_buf kexjmp;
62Key *kexjmp_key;
63
64/*
65 * Keep a connection structure for each file descriptor.  The state
66 * associated with file descriptor n is held in fdcon[n].
67 */
68typedef struct Connection {
69	u_char c_status;	/* State of connection on this file desc. */
70#define CS_UNUSED 0		/* File descriptor unused */
71#define CS_CON 1		/* Waiting to connect/read greeting */
72#define CS_SIZE 2		/* Waiting to read initial packet size */
73#define CS_KEYS 3		/* Waiting to read public key packet */
74	int c_fd;		/* Quick lookup: c->c_fd == c - fdcon */
75	int c_plen;		/* Packet length field for ssh packet */
76	int c_len;		/* Total bytes which must be read. */
77	int c_off;		/* Length of data read so far. */
78	int c_keytype;		/* Only one of KT_RSA1, KT_DSA, or KT_RSA */
79	char *c_namebase;	/* Address to free for c_name and c_namelist */
80	char *c_name;		/* Hostname of connection for errors */
81	char *c_namelist;	/* Pointer to other possible addresses */
82	char *c_output_name;	/* Hostname of connection for output */
83	char *c_data;		/* Data read from this fd */
84	Kex *c_kex;		/* The key-exchange struct for ssh2 */
85	struct timeval c_tv;	/* Time at which connection gets aborted */
86	TAILQ_ENTRY(Connection) c_link;	/* List of connections in timeout order. */
87} con;
88
89TAILQ_HEAD(conlist, Connection) tq;	/* Timeout Queue */
90con *fdcon;
91
92/*
93 *  This is just a wrapper around fgets() to make it usable.
94 */
95
96/* Stress-test.  Increase this later. */
97#define LINEBUF_SIZE 16
98
99typedef struct {
100	char *buf;
101	u_int size;
102	int lineno;
103	const char *filename;
104	FILE *stream;
105	void (*errfun) (const char *,...);
106} Linebuf;
107
108static Linebuf *
109Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
110{
111	Linebuf *lb;
112
113	if (!(lb = malloc(sizeof(*lb)))) {
114		if (errfun)
115			(*errfun) ("linebuf (%s): malloc failed\n",
116			    filename ? filename : "(stdin)");
117		return (NULL);
118	}
119	if (filename) {
120		lb->filename = filename;
121		if (!(lb->stream = fopen(filename, "r"))) {
122			xfree(lb);
123			if (errfun)
124				(*errfun) ("%s: %s\n", filename, strerror(errno));
125			return (NULL);
126		}
127	} else {
128		lb->filename = "(stdin)";
129		lb->stream = stdin;
130	}
131
132	if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
133		if (errfun)
134			(*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
135		xfree(lb);
136		return (NULL);
137	}
138	lb->errfun = errfun;
139	lb->lineno = 0;
140	return (lb);
141}
142
143static void
144Linebuf_free(Linebuf * lb)
145{
146	fclose(lb->stream);
147	xfree(lb->buf);
148	xfree(lb);
149}
150
151#if 0
152static void
153Linebuf_restart(Linebuf * lb)
154{
155	clearerr(lb->stream);
156	rewind(lb->stream);
157	lb->lineno = 0;
158}
159
160static int
161Linebuf_lineno(Linebuf * lb)
162{
163	return (lb->lineno);
164}
165#endif
166
167static char *
168Linebuf_getline(Linebuf * lb)
169{
170	int n = 0;
171	void *p;
172
173	lb->lineno++;
174	for (;;) {
175		/* Read a line */
176		if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
177			if (ferror(lb->stream) && lb->errfun)
178				(*lb->errfun)("%s: %s\n", lb->filename,
179				    strerror(errno));
180			return (NULL);
181		}
182		n = strlen(lb->buf);
183
184		/* Return it or an error if it fits */
185		if (n > 0 && lb->buf[n - 1] == '\n') {
186			lb->buf[n - 1] = '\0';
187			return (lb->buf);
188		}
189		if (n != lb->size - 1) {
190			if (lb->errfun)
191				(*lb->errfun)("%s: skipping incomplete last line\n",
192				    lb->filename);
193			return (NULL);
194		}
195		/* Double the buffer if we need more space */
196		lb->size *= 2;
197		if ((p = realloc(lb->buf, lb->size)) == NULL) {
198			lb->size /= 2;
199			if (lb->errfun)
200				(*lb->errfun)("linebuf (%s): realloc failed\n",
201				    lb->filename);
202			return (NULL);
203		}
204		lb->buf = p;
205	}
206}
207
208static int
209fdlim_get(int hard)
210{
211#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
212	struct rlimit rlfd;
213
214	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
215		return (-1);
216	if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
217		return SSH_SYSFDMAX;
218	else
219		return hard ? rlfd.rlim_max : rlfd.rlim_cur;
220#else
221	return SSH_SYSFDMAX;
222#endif
223}
224
225static int
226fdlim_set(int lim)
227{
228#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
229	struct rlimit rlfd;
230#endif
231
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 */
251static char *
252xstrsep(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 */
273static char *
274strnnsep(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
284static Key *
285keygrab_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
318static int
319hostjump(Key *hostkey)
320{
321	kexjmp_key = hostkey;
322	longjmp(kexjmp, 1);
323}
324
325static int
326ssh2_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
341static Key *
342keygrab_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->kex[KEX_DH_GRP1_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
369static void
370keyprint(con *c, Key *key)
371{
372	if (!key)
373		return;
374
375	fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
376	key_write(key, stdout);
377	fputs("\n", stdout);
378}
379
380static int
381tcpconnect(char *host)
382{
383	struct addrinfo hints, *ai, *aitop;
384	char strport[NI_MAXSERV];
385	int gaierr, s = -1;
386
387	snprintf(strport, sizeof strport, "%d", ssh_port);
388	memset(&hints, 0, sizeof(hints));
389	hints.ai_family = IPv4or6;
390	hints.ai_socktype = SOCK_STREAM;
391	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
392		fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
393	for (ai = aitop; ai; ai = ai->ai_next) {
394		s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
395		if (s < 0) {
396			error("socket: %s", strerror(errno));
397			continue;
398		}
399		if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
400			fatal("F_SETFL: %s", strerror(errno));
401		if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
402		    errno != EINPROGRESS)
403			error("connect (`%s'): %s", host, strerror(errno));
404		else
405			break;
406		close(s);
407		s = -1;
408	}
409	freeaddrinfo(aitop);
410	return s;
411}
412
413static int
414conalloc(char *iname, char *oname, int keytype)
415{
416	char *namebase, *name, *namelist;
417	int s;
418
419	namebase = namelist = xstrdup(iname);
420
421	do {
422		name = xstrsep(&namelist, ",");
423		if (!name) {
424			xfree(namebase);
425			return (-1);
426		}
427	} while ((s = tcpconnect(name)) < 0);
428
429	if (s >= maxfd)
430		fatal("conalloc: fdno %d too high", s);
431	if (fdcon[s].c_status)
432		fatal("conalloc: attempt to reuse fdno %d", s);
433
434	fdcon[s].c_fd = s;
435	fdcon[s].c_status = CS_CON;
436	fdcon[s].c_namebase = namebase;
437	fdcon[s].c_name = name;
438	fdcon[s].c_namelist = namelist;
439	fdcon[s].c_output_name = xstrdup(oname);
440	fdcon[s].c_data = (char *) &fdcon[s].c_plen;
441	fdcon[s].c_len = 4;
442	fdcon[s].c_off = 0;
443	fdcon[s].c_keytype = keytype;
444	gettimeofday(&fdcon[s].c_tv, NULL);
445	fdcon[s].c_tv.tv_sec += timeout;
446	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
447	FD_SET(s, read_wait);
448	ncon++;
449	return (s);
450}
451
452static void
453confree(int s)
454{
455	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
456		fatal("confree: attempt to free bad fdno %d", s);
457	close(s);
458	xfree(fdcon[s].c_namebase);
459	xfree(fdcon[s].c_output_name);
460	if (fdcon[s].c_status == CS_KEYS)
461		xfree(fdcon[s].c_data);
462	fdcon[s].c_status = CS_UNUSED;
463	fdcon[s].c_keytype = 0;
464	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
465	FD_CLR(s, read_wait);
466	ncon--;
467}
468
469static void
470contouch(int s)
471{
472	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
473	gettimeofday(&fdcon[s].c_tv, NULL);
474	fdcon[s].c_tv.tv_sec += timeout;
475	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
476}
477
478static int
479conrecycle(int s)
480{
481	con *c = &fdcon[s];
482	int ret;
483
484	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
485	confree(s);
486	return (ret);
487}
488
489static void
490congreet(int s)
491{
492	int remote_major = 0, remote_minor = 0, n = 0;
493	char buf[256], *cp;
494	char remote_version[sizeof buf];
495	size_t bufsiz;
496	con *c = &fdcon[s];
497
498	bufsiz = sizeof(buf);
499	cp = buf;
500	while (bufsiz-- && (n = read(s, cp, 1)) == 1 && *cp != '\n') {
501		if (*cp == '\r')
502			*cp = '\n';
503		cp++;
504	}
505	if (n < 0) {
506		if (errno != ECONNREFUSED)
507			error("read (%s): %s", c->c_name, strerror(errno));
508		conrecycle(s);
509		return;
510	}
511	if (n == 0) {
512		error("%s: Connection closed by remote host", c->c_name);
513		conrecycle(s);
514		return;
515	}
516	if (*cp != '\n' && *cp != '\r') {
517		error("%s: bad greeting", c->c_name);
518		confree(s);
519		return;
520	}
521	*cp = '\0';
522	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
523	    &remote_major, &remote_minor, remote_version) == 3)
524		compat_datafellows(remote_version);
525	else
526		datafellows = 0;
527	if (c->c_keytype != KT_RSA1) {
528		if (!ssh2_capable(remote_major, remote_minor)) {
529			debug("%s doesn't support ssh2", c->c_name);
530			confree(s);
531			return;
532		}
533	} else if (remote_major != 1) {
534		debug("%s doesn't support ssh1", c->c_name);
535		confree(s);
536		return;
537	}
538	fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
539	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
540	    c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
541	    c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
542	if (atomicio(vwrite, s, buf, n) != n) {
543		error("write (%s): %s", c->c_name, strerror(errno));
544		confree(s);
545		return;
546	}
547	if (c->c_keytype != KT_RSA1) {
548		keyprint(c, keygrab_ssh2(c));
549		confree(s);
550		return;
551	}
552	c->c_status = CS_SIZE;
553	contouch(s);
554}
555
556static void
557conread(int s)
558{
559	con *c = &fdcon[s];
560	int n;
561
562	if (c->c_status == CS_CON) {
563		congreet(s);
564		return;
565	}
566	n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
567	if (n < 0) {
568		error("read (%s): %s", c->c_name, strerror(errno));
569		confree(s);
570		return;
571	}
572	c->c_off += n;
573
574	if (c->c_off == c->c_len)
575		switch (c->c_status) {
576		case CS_SIZE:
577			c->c_plen = htonl(c->c_plen);
578			c->c_len = c->c_plen + 8 - (c->c_plen & 7);
579			c->c_off = 0;
580			c->c_data = xmalloc(c->c_len);
581			c->c_status = CS_KEYS;
582			break;
583		case CS_KEYS:
584			keyprint(c, keygrab_ssh1(c));
585			confree(s);
586			return;
587			break;
588		default:
589			fatal("conread: invalid status %d", c->c_status);
590			break;
591		}
592
593	contouch(s);
594}
595
596static void
597conloop(void)
598{
599	struct timeval seltime, now;
600	fd_set *r, *e;
601	con *c;
602	int i;
603
604	gettimeofday(&now, NULL);
605	c = TAILQ_FIRST(&tq);
606
607	if (c && (c->c_tv.tv_sec > now.tv_sec ||
608	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
609		seltime = c->c_tv;
610		seltime.tv_sec -= now.tv_sec;
611		seltime.tv_usec -= now.tv_usec;
612		if (seltime.tv_usec < 0) {
613			seltime.tv_usec += 1000000;
614			seltime.tv_sec--;
615		}
616	} else
617		seltime.tv_sec = seltime.tv_usec = 0;
618
619	r = xmalloc(read_wait_size);
620	memcpy(r, read_wait, read_wait_size);
621	e = xmalloc(read_wait_size);
622	memcpy(e, read_wait, read_wait_size);
623
624	while (select(maxfd, r, NULL, e, &seltime) == -1 &&
625	    (errno == EAGAIN || errno == EINTR))
626		;
627
628	for (i = 0; i < maxfd; i++) {
629		if (FD_ISSET(i, e)) {
630			error("%s: exception!", fdcon[i].c_name);
631			confree(i);
632		} else if (FD_ISSET(i, r))
633			conread(i);
634	}
635	xfree(r);
636	xfree(e);
637
638	c = TAILQ_FIRST(&tq);
639	while (c && (c->c_tv.tv_sec < now.tv_sec ||
640	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
641		int s = c->c_fd;
642
643		c = TAILQ_NEXT(c, c_link);
644		conrecycle(s);
645	}
646}
647
648static void
649do_host(char *host)
650{
651	char *name = strnnsep(&host, " \t\n");
652	int j;
653
654	if (name == NULL)
655		return;
656	for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
657		if (get_keytypes & j) {
658			while (ncon >= MAXCON)
659				conloop();
660			conalloc(name, *host ? host : name, j);
661		}
662	}
663}
664
665void
666fatal(const char *fmt,...)
667{
668	va_list args;
669
670	va_start(args, fmt);
671	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
672	va_end(args);
673	if (nonfatal_fatal)
674		longjmp(kexjmp, -1);
675	else
676		exit(255);
677}
678
679static void
680usage(void)
681{
682	fprintf(stderr, "usage: %s [-v46] [-p port] [-T timeout] [-t type] [-f file]\n"
683	    "\t\t   [host | addrlist namelist] [...]\n",
684	    __progname);
685	exit(1);
686}
687
688int
689main(int argc, char **argv)
690{
691	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
692	int opt, fopt_count = 0;
693	char *tname;
694
695	extern int optind;
696	extern char *optarg;
697
698	__progname = ssh_get_progname(argv[0]);
699	init_rng();
700	seed_rng();
701	TAILQ_INIT(&tq);
702
703	if (argc <= 1)
704		usage();
705
706	while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
707		switch (opt) {
708		case 'p':
709			ssh_port = a2port(optarg);
710			if (ssh_port == 0) {
711				fprintf(stderr, "Bad port '%s'\n", optarg);
712				exit(1);
713			}
714			break;
715		case 'T':
716			timeout = convtime(optarg);
717			if (timeout == -1 || timeout == 0) {
718				fprintf(stderr, "Bad timeout '%s'\n", optarg);
719				usage();
720			}
721			break;
722		case 'v':
723			if (!debug_flag) {
724				debug_flag = 1;
725				log_level = SYSLOG_LEVEL_DEBUG1;
726			}
727			else if (log_level < SYSLOG_LEVEL_DEBUG3)
728				log_level++;
729			else
730				fatal("Too high debugging level.");
731			break;
732		case 'f':
733			if (strcmp(optarg, "-") == 0)
734				optarg = NULL;
735			argv[fopt_count++] = optarg;
736			break;
737		case 't':
738			get_keytypes = 0;
739			tname = strtok(optarg, ",");
740			while (tname) {
741				int type = key_type_from_name(tname);
742				switch (type) {
743				case KEY_RSA1:
744					get_keytypes |= KT_RSA1;
745					break;
746				case KEY_DSA:
747					get_keytypes |= KT_DSA;
748					break;
749				case KEY_RSA:
750					get_keytypes |= KT_RSA;
751					break;
752				case KEY_UNSPEC:
753					fatal("unknown key type %s", tname);
754				}
755				tname = strtok(NULL, ",");
756			}
757			break;
758		case '4':
759			IPv4or6 = AF_INET;
760			break;
761		case '6':
762			IPv4or6 = AF_INET6;
763			break;
764		case '?':
765		default:
766			usage();
767		}
768	}
769	if (optind == argc && !fopt_count)
770		usage();
771
772	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
773
774	maxfd = fdlim_get(1);
775	if (maxfd < 0)
776		fatal("%s: fdlim_get: bad value", __progname);
777	if (maxfd > MAXMAXFD)
778		maxfd = MAXMAXFD;
779	if (MAXCON <= 0)
780		fatal("%s: not enough file descriptors", __progname);
781	if (maxfd > fdlim_get(0))
782		fdlim_set(maxfd);
783	fdcon = xmalloc(maxfd * sizeof(con));
784	memset(fdcon, 0, maxfd * sizeof(con));
785
786	read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
787	read_wait = xmalloc(read_wait_size);
788	memset(read_wait, 0, read_wait_size);
789
790	if (fopt_count) {
791		Linebuf *lb;
792		char *line;
793		int j;
794
795		for (j = 0; j < fopt_count; j++) {
796			lb = Linebuf_alloc(argv[j], error);
797			if (!lb)
798				continue;
799			while ((line = Linebuf_getline(lb)) != NULL)
800				do_host(line);
801			Linebuf_free(lb);
802		}
803	}
804
805	while (optind < argc)
806		do_host(argv[optind++]);
807
808	while (ncon > 0)
809		conloop();
810
811	return (0);
812}
813