ssh-keyscan.c revision 262566 
1/* $OpenBSD: ssh-keyscan.c,v 1.89 2013/12/06 13:39:49 markus 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 "includes.h"
11
12#include "openbsd-compat/sys-queue.h"
13#include <sys/resource.h>
14#ifdef HAVE_SYS_TIME_H
15# include <sys/time.h>
16#endif
17
18#include <netinet/in.h>
19#include <arpa/inet.h>
20
21#include <openssl/bn.h>
22
23#include <netdb.h>
24#include <errno.h>
25#include <setjmp.h>
26#include <stdarg.h>
27#include <stdio.h>
28#include <stdlib.h>
29#include <signal.h>
30#include <string.h>
31#include <unistd.h>
32
33#include "xmalloc.h"
34#include "ssh.h"
35#include "ssh1.h"
36#include "buffer.h"
37#include "key.h"
38#include "cipher.h"
39#include "kex.h"
40#include "compat.h"
41#include "myproposal.h"
42#include "packet.h"
43#include "dispatch.h"
44#include "log.h"
45#include "atomicio.h"
46#include "misc.h"
47#include "hostfile.h"
48
49/* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
50   Default value is AF_UNSPEC means both IPv4 and IPv6. */
51int IPv4or6 = AF_UNSPEC;
52
53int ssh_port = SSH_DEFAULT_PORT;
54
55#define KT_RSA1		1
56#define KT_DSA		2
57#define KT_RSA		4
58#define KT_ECDSA	8
59#define KT_ED25519	16
60
61int get_keytypes = KT_RSA|KT_ECDSA;/* Get RSA and ECDSA keys by default */
62
63int hash_hosts = 0;		/* Hash hostname on output */
64
65#define MAXMAXFD 256
66
67/* The number of seconds after which to give up on a TCP connection */
68int timeout = 5;
69
70int maxfd;
71#define MAXCON (maxfd - 10)
72
73extern char *__progname;
74fd_set *read_wait;
75size_t read_wait_nfdset;
76int ncon;
77int nonfatal_fatal = 0;
78jmp_buf kexjmp;
79Key *kexjmp_key;
80
81/*
82 * Keep a connection structure for each file descriptor.  The state
83 * associated with file descriptor n is held in fdcon[n].
84 */
85typedef struct Connection {
86	u_char c_status;	/* State of connection on this file desc. */
87#define CS_UNUSED 0		/* File descriptor unused */
88#define CS_CON 1		/* Waiting to connect/read greeting */
89#define CS_SIZE 2		/* Waiting to read initial packet size */
90#define CS_KEYS 3		/* Waiting to read public key packet */
91	int c_fd;		/* Quick lookup: c->c_fd == c - fdcon */
92	int c_plen;		/* Packet length field for ssh packet */
93	int c_len;		/* Total bytes which must be read. */
94	int c_off;		/* Length of data read so far. */
95	int c_keytype;		/* Only one of KT_RSA1, KT_DSA, or KT_RSA */
96	char *c_namebase;	/* Address to free for c_name and c_namelist */
97	char *c_name;		/* Hostname of connection for errors */
98	char *c_namelist;	/* Pointer to other possible addresses */
99	char *c_output_name;	/* Hostname of connection for output */
100	char *c_data;		/* Data read from this fd */
101	Kex *c_kex;		/* The key-exchange struct for ssh2 */
102	struct timeval c_tv;	/* Time at which connection gets aborted */
103	TAILQ_ENTRY(Connection) c_link;	/* List of connections in timeout order. */
104} con;
105
106TAILQ_HEAD(conlist, Connection) tq;	/* Timeout Queue */
107con *fdcon;
108
109static int
110fdlim_get(int hard)
111{
112#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
113	struct rlimit rlfd;
114
115	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
116		return (-1);
117	if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
118		return SSH_SYSFDMAX;
119	else
120		return hard ? rlfd.rlim_max : rlfd.rlim_cur;
121#else
122	return SSH_SYSFDMAX;
123#endif
124}
125
126static int
127fdlim_set(int lim)
128{
129#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
130	struct rlimit rlfd;
131#endif
132
133	if (lim <= 0)
134		return (-1);
135#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
136	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
137		return (-1);
138	rlfd.rlim_cur = lim;
139	if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
140		return (-1);
141#elif defined (HAVE_SETDTABLESIZE)
142	setdtablesize(lim);
143#endif
144	return (0);
145}
146
147/*
148 * This is an strsep function that returns a null field for adjacent
149 * separators.  This is the same as the 4.4BSD strsep, but different from the
150 * one in the GNU libc.
151 */
152static char *
153xstrsep(char **str, const char *delim)
154{
155	char *s, *e;
156
157	if (!**str)
158		return (NULL);
159
160	s = *str;
161	e = s + strcspn(s, delim);
162
163	if (*e != '\0')
164		*e++ = '\0';
165	*str = e;
166
167	return (s);
168}
169
170/*
171 * Get the next non-null token (like GNU strsep).  Strsep() will return a
172 * null token for two adjacent separators, so we may have to loop.
173 */
174static char *
175strnnsep(char **stringp, char *delim)
176{
177	char *tok;
178
179	do {
180		tok = xstrsep(stringp, delim);
181	} while (tok && *tok == '\0');
182	return (tok);
183}
184
185static Key *
186keygrab_ssh1(con *c)
187{
188	static Key *rsa;
189	static Buffer msg;
190
191	if (rsa == NULL) {
192		buffer_init(&msg);
193		rsa = key_new(KEY_RSA1);
194	}
195	buffer_append(&msg, c->c_data, c->c_plen);
196	buffer_consume(&msg, 8 - (c->c_plen & 7));	/* padding */
197	if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
198		error("%s: invalid packet type", c->c_name);
199		buffer_clear(&msg);
200		return NULL;
201	}
202	buffer_consume(&msg, 8);		/* cookie */
203
204	/* server key */
205	(void) buffer_get_int(&msg);
206	buffer_get_bignum(&msg, rsa->rsa->e);
207	buffer_get_bignum(&msg, rsa->rsa->n);
208
209	/* host key */
210	(void) buffer_get_int(&msg);
211	buffer_get_bignum(&msg, rsa->rsa->e);
212	buffer_get_bignum(&msg, rsa->rsa->n);
213
214	buffer_clear(&msg);
215
216	return (rsa);
217}
218
219static int
220hostjump(Key *hostkey)
221{
222	kexjmp_key = hostkey;
223	longjmp(kexjmp, 1);
224}
225
226static int
227ssh2_capable(int remote_major, int remote_minor)
228{
229	switch (remote_major) {
230	case 1:
231		if (remote_minor == 99)
232			return 1;
233		break;
234	case 2:
235		return 1;
236	default:
237		break;
238	}
239	return 0;
240}
241
242static Key *
243keygrab_ssh2(con *c)
244{
245	int j;
246
247	packet_set_connection(c->c_fd, c->c_fd);
248	enable_compat20();
249	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
250	    c->c_keytype == KT_DSA ?  "ssh-dss" :
251	    (c->c_keytype == KT_RSA ? "ssh-rsa" :
252	    (c->c_keytype == KT_ED25519 ? "ssh-ed25519" :
253	    "ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521"));
254	c->c_kex = kex_setup(myproposal);
255	c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
256	c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
257	c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
258	c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
259	c->c_kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
260	c->c_kex->kex[KEX_C25519_SHA256] = kexc25519_client;
261	c->c_kex->verify_host_key = hostjump;
262
263	if (!(j = setjmp(kexjmp))) {
264		nonfatal_fatal = 1;
265		dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
266		fprintf(stderr, "Impossible! dispatch_run() returned!\n");
267		exit(1);
268	}
269	nonfatal_fatal = 0;
270	free(c->c_kex);
271	c->c_kex = NULL;
272	packet_close();
273
274	return j < 0? NULL : kexjmp_key;
275}
276
277static void
278keyprint(con *c, Key *key)
279{
280	char *host = c->c_output_name ? c->c_output_name : c->c_name;
281
282	if (!key)
283		return;
284	if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
285		fatal("host_hash failed");
286
287	fprintf(stdout, "%s ", host);
288	key_write(key, stdout);
289	fputs("\n", stdout);
290}
291
292static int
293tcpconnect(char *host)
294{
295	struct addrinfo hints, *ai, *aitop;
296	char strport[NI_MAXSERV];
297	int gaierr, s = -1;
298
299	snprintf(strport, sizeof strport, "%d", ssh_port);
300	memset(&hints, 0, sizeof(hints));
301	hints.ai_family = IPv4or6;
302	hints.ai_socktype = SOCK_STREAM;
303	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
304		fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
305	for (ai = aitop; ai; ai = ai->ai_next) {
306		s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
307		if (s < 0) {
308			error("socket: %s", strerror(errno));
309			continue;
310		}
311		if (set_nonblock(s) == -1)
312			fatal("%s: set_nonblock(%d)", __func__, s);
313		if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
314		    errno != EINPROGRESS)
315			error("connect (`%s'): %s", host, strerror(errno));
316		else
317			break;
318		close(s);
319		s = -1;
320	}
321	freeaddrinfo(aitop);
322	return s;
323}
324
325static int
326conalloc(char *iname, char *oname, int keytype)
327{
328	char *namebase, *name, *namelist;
329	int s;
330
331	namebase = namelist = xstrdup(iname);
332
333	do {
334		name = xstrsep(&namelist, ",");
335		if (!name) {
336			free(namebase);
337			return (-1);
338		}
339	} while ((s = tcpconnect(name)) < 0);
340
341	if (s >= maxfd)
342		fatal("conalloc: fdno %d too high", s);
343	if (fdcon[s].c_status)
344		fatal("conalloc: attempt to reuse fdno %d", s);
345
346	fdcon[s].c_fd = s;
347	fdcon[s].c_status = CS_CON;
348	fdcon[s].c_namebase = namebase;
349	fdcon[s].c_name = name;
350	fdcon[s].c_namelist = namelist;
351	fdcon[s].c_output_name = xstrdup(oname);
352	fdcon[s].c_data = (char *) &fdcon[s].c_plen;
353	fdcon[s].c_len = 4;
354	fdcon[s].c_off = 0;
355	fdcon[s].c_keytype = keytype;
356	gettimeofday(&fdcon[s].c_tv, NULL);
357	fdcon[s].c_tv.tv_sec += timeout;
358	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
359	FD_SET(s, read_wait);
360	ncon++;
361	return (s);
362}
363
364static void
365confree(int s)
366{
367	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
368		fatal("confree: attempt to free bad fdno %d", s);
369	close(s);
370	free(fdcon[s].c_namebase);
371	free(fdcon[s].c_output_name);
372	if (fdcon[s].c_status == CS_KEYS)
373		free(fdcon[s].c_data);
374	fdcon[s].c_status = CS_UNUSED;
375	fdcon[s].c_keytype = 0;
376	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
377	FD_CLR(s, read_wait);
378	ncon--;
379}
380
381static void
382contouch(int s)
383{
384	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
385	gettimeofday(&fdcon[s].c_tv, NULL);
386	fdcon[s].c_tv.tv_sec += timeout;
387	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
388}
389
390static int
391conrecycle(int s)
392{
393	con *c = &fdcon[s];
394	int ret;
395
396	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
397	confree(s);
398	return (ret);
399}
400
401static void
402congreet(int s)
403{
404	int n = 0, remote_major = 0, remote_minor = 0;
405	char buf[256], *cp;
406	char remote_version[sizeof buf];
407	size_t bufsiz;
408	con *c = &fdcon[s];
409
410	for (;;) {
411		memset(buf, '\0', sizeof(buf));
412		bufsiz = sizeof(buf);
413		cp = buf;
414		while (bufsiz-- &&
415		    (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
416			if (*cp == '\r')
417				*cp = '\n';
418			cp++;
419		}
420		if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
421			break;
422	}
423	if (n == 0) {
424		switch (errno) {
425		case EPIPE:
426			error("%s: Connection closed by remote host", c->c_name);
427			break;
428		case ECONNREFUSED:
429			break;
430		default:
431			error("read (%s): %s", c->c_name, strerror(errno));
432			break;
433		}
434		conrecycle(s);
435		return;
436	}
437	if (*cp != '\n' && *cp != '\r') {
438		error("%s: bad greeting", c->c_name);
439		confree(s);
440		return;
441	}
442	*cp = '\0';
443	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
444	    &remote_major, &remote_minor, remote_version) == 3)
445		compat_datafellows(remote_version);
446	else
447		datafellows = 0;
448	if (c->c_keytype != KT_RSA1) {
449		if (!ssh2_capable(remote_major, remote_minor)) {
450			debug("%s doesn't support ssh2", c->c_name);
451			confree(s);
452			return;
453		}
454	} else if (remote_major != 1) {
455		debug("%s doesn't support ssh1", c->c_name);
456		confree(s);
457		return;
458	}
459	fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
460	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
461	    c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
462	    c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
463	if (n < 0 || (size_t)n >= sizeof(buf)) {
464		error("snprintf: buffer too small");
465		confree(s);
466		return;
467	}
468	if (atomicio(vwrite, s, buf, n) != (size_t)n) {
469		error("write (%s): %s", c->c_name, strerror(errno));
470		confree(s);
471		return;
472	}
473	if (c->c_keytype != KT_RSA1) {
474		keyprint(c, keygrab_ssh2(c));
475		confree(s);
476		return;
477	}
478	c->c_status = CS_SIZE;
479	contouch(s);
480}
481
482static void
483conread(int s)
484{
485	con *c = &fdcon[s];
486	size_t n;
487
488	if (c->c_status == CS_CON) {
489		congreet(s);
490		return;
491	}
492	n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
493	if (n == 0) {
494		error("read (%s): %s", c->c_name, strerror(errno));
495		confree(s);
496		return;
497	}
498	c->c_off += n;
499
500	if (c->c_off == c->c_len)
501		switch (c->c_status) {
502		case CS_SIZE:
503			c->c_plen = htonl(c->c_plen);
504			c->c_len = c->c_plen + 8 - (c->c_plen & 7);
505			c->c_off = 0;
506			c->c_data = xmalloc(c->c_len);
507			c->c_status = CS_KEYS;
508			break;
509		case CS_KEYS:
510			keyprint(c, keygrab_ssh1(c));
511			confree(s);
512			return;
513		default:
514			fatal("conread: invalid status %d", c->c_status);
515			break;
516		}
517
518	contouch(s);
519}
520
521static void
522conloop(void)
523{
524	struct timeval seltime, now;
525	fd_set *r, *e;
526	con *c;
527	int i;
528
529	gettimeofday(&now, NULL);
530	c = TAILQ_FIRST(&tq);
531
532	if (c && (c->c_tv.tv_sec > now.tv_sec ||
533	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
534		seltime = c->c_tv;
535		seltime.tv_sec -= now.tv_sec;
536		seltime.tv_usec -= now.tv_usec;
537		if (seltime.tv_usec < 0) {
538			seltime.tv_usec += 1000000;
539			seltime.tv_sec--;
540		}
541	} else
542		timerclear(&seltime);
543
544	r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
545	e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
546	memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
547	memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
548
549	while (select(maxfd, r, NULL, e, &seltime) == -1 &&
550	    (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
551		;
552
553	for (i = 0; i < maxfd; i++) {
554		if (FD_ISSET(i, e)) {
555			error("%s: exception!", fdcon[i].c_name);
556			confree(i);
557		} else if (FD_ISSET(i, r))
558			conread(i);
559	}
560	free(r);
561	free(e);
562
563	c = TAILQ_FIRST(&tq);
564	while (c && (c->c_tv.tv_sec < now.tv_sec ||
565	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
566		int s = c->c_fd;
567
568		c = TAILQ_NEXT(c, c_link);
569		conrecycle(s);
570	}
571}
572
573static void
574do_host(char *host)
575{
576	char *name = strnnsep(&host, " \t\n");
577	int j;
578
579	if (name == NULL)
580		return;
581	for (j = KT_RSA1; j <= KT_ED25519; j *= 2) {
582		if (get_keytypes & j) {
583			while (ncon >= MAXCON)
584				conloop();
585			conalloc(name, *host ? host : name, j);
586		}
587	}
588}
589
590void
591fatal(const char *fmt,...)
592{
593	va_list args;
594
595	va_start(args, fmt);
596	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
597	va_end(args);
598	if (nonfatal_fatal)
599		longjmp(kexjmp, -1);
600	else
601		exit(255);
602}
603
604static void
605usage(void)
606{
607	fprintf(stderr,
608	    "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
609	    "\t\t   [host | addrlist namelist] ...\n",
610	    __progname);
611	exit(1);
612}
613
614int
615main(int argc, char **argv)
616{
617	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
618	int opt, fopt_count = 0, j;
619	char *tname, *cp, line[NI_MAXHOST];
620	FILE *fp;
621	u_long linenum;
622
623	extern int optind;
624	extern char *optarg;
625
626	__progname = ssh_get_progname(argv[0]);
627	seed_rng();
628	TAILQ_INIT(&tq);
629
630	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
631	sanitise_stdfd();
632
633	if (argc <= 1)
634		usage();
635
636	while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
637		switch (opt) {
638		case 'H':
639			hash_hosts = 1;
640			break;
641		case 'p':
642			ssh_port = a2port(optarg);
643			if (ssh_port <= 0) {
644				fprintf(stderr, "Bad port '%s'\n", optarg);
645				exit(1);
646			}
647			break;
648		case 'T':
649			timeout = convtime(optarg);
650			if (timeout == -1 || timeout == 0) {
651				fprintf(stderr, "Bad timeout '%s'\n", optarg);
652				usage();
653			}
654			break;
655		case 'v':
656			if (!debug_flag) {
657				debug_flag = 1;
658				log_level = SYSLOG_LEVEL_DEBUG1;
659			}
660			else if (log_level < SYSLOG_LEVEL_DEBUG3)
661				log_level++;
662			else
663				fatal("Too high debugging level.");
664			break;
665		case 'f':
666			if (strcmp(optarg, "-") == 0)
667				optarg = NULL;
668			argv[fopt_count++] = optarg;
669			break;
670		case 't':
671			get_keytypes = 0;
672			tname = strtok(optarg, ",");
673			while (tname) {
674				int type = key_type_from_name(tname);
675				switch (type) {
676				case KEY_RSA1:
677					get_keytypes |= KT_RSA1;
678					break;
679				case KEY_DSA:
680					get_keytypes |= KT_DSA;
681					break;
682				case KEY_ECDSA:
683					get_keytypes |= KT_ECDSA;
684					break;
685				case KEY_RSA:
686					get_keytypes |= KT_RSA;
687					break;
688				case KEY_ED25519:
689					get_keytypes |= KT_ED25519;
690					break;
691				case KEY_UNSPEC:
692					fatal("unknown key type %s", tname);
693				}
694				tname = strtok(NULL, ",");
695			}
696			break;
697		case '4':
698			IPv4or6 = AF_INET;
699			break;
700		case '6':
701			IPv4or6 = AF_INET6;
702			break;
703		case '?':
704		default:
705			usage();
706		}
707	}
708	if (optind == argc && !fopt_count)
709		usage();
710
711	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
712
713	maxfd = fdlim_get(1);
714	if (maxfd < 0)
715		fatal("%s: fdlim_get: bad value", __progname);
716	if (maxfd > MAXMAXFD)
717		maxfd = MAXMAXFD;
718	if (MAXCON <= 0)
719		fatal("%s: not enough file descriptors", __progname);
720	if (maxfd > fdlim_get(0))
721		fdlim_set(maxfd);
722	fdcon = xcalloc(maxfd, sizeof(con));
723
724	read_wait_nfdset = howmany(maxfd, NFDBITS);
725	read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
726
727	for (j = 0; j < fopt_count; j++) {
728		if (argv[j] == NULL)
729			fp = stdin;
730		else if ((fp = fopen(argv[j], "r")) == NULL)
731			fatal("%s: %s: %s", __progname, argv[j],
732			    strerror(errno));
733		linenum = 0;
734
735		while (read_keyfile_line(fp,
736		    argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
737		    &linenum) != -1) {
738			/* Chomp off trailing whitespace and comments */
739			if ((cp = strchr(line, '#')) == NULL)
740				cp = line + strlen(line) - 1;
741			while (cp >= line) {
742				if (*cp == ' ' || *cp == '\t' ||
743				    *cp == '\n' || *cp == '#')
744					*cp-- = '\0';
745				else
746					break;
747			}
748
749			/* Skip empty lines */
750			if (*line == '\0')
751				continue;
752
753			do_host(line);
754		}
755
756		if (ferror(fp))
757			fatal("%s: %s: %s", __progname, argv[j],
758			    strerror(errno));
759
760		fclose(fp);
761	}
762
763	while (optind < argc)
764		do_host(argv[optind++]);
765
766	while (ncon > 0)
767		conloop();
768
769	return (0);
770}
771