ssh-keyscan.c revision 113911 
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 1.41 2003/02/16 17:09:57 markus Exp $");
11RCSID("$FreeBSD: head/crypto/openssh/ssh-keyscan.c 113911 2003-04-23 17:13:13Z 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->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
359	c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
360	c->c_kex->verify_host_key = hostjump;
361
362	if (!(j = setjmp(kexjmp))) {
363		nonfatal_fatal = 1;
364		dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
365		fprintf(stderr, "Impossible! dispatch_run() returned!\n");
366		exit(1);
367	}
368	nonfatal_fatal = 0;
369	xfree(c->c_kex);
370	c->c_kex = NULL;
371	packet_close();
372
373	return j < 0? NULL : kexjmp_key;
374}
375
376static void
377keyprint(con *c, Key *key)
378{
379	if (!key)
380		return;
381
382	fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
383	key_write(key, stdout);
384	fputs("\n", stdout);
385}
386
387static int
388tcpconnect(char *host)
389{
390	struct addrinfo hints, *ai, *aitop;
391	char strport[NI_MAXSERV];
392	int gaierr, s = -1;
393
394	snprintf(strport, sizeof strport, "%d", ssh_port);
395	memset(&hints, 0, sizeof(hints));
396	hints.ai_family = IPv4or6;
397	hints.ai_socktype = SOCK_STREAM;
398	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
399		fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
400	for (ai = aitop; ai; ai = ai->ai_next) {
401		s = socket(ai->ai_family, SOCK_STREAM, 0);
402		if (s < 0) {
403			error("socket: %s", strerror(errno));
404			continue;
405		}
406		if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
407			fatal("F_SETFL: %s", strerror(errno));
408		if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
409		    errno != EINPROGRESS)
410			error("connect (`%s'): %s", host, strerror(errno));
411		else
412			break;
413		close(s);
414		s = -1;
415	}
416	freeaddrinfo(aitop);
417	return s;
418}
419
420static int
421conalloc(char *iname, char *oname, int keytype)
422{
423	char *namebase, *name, *namelist;
424	int s;
425
426	namebase = namelist = xstrdup(iname);
427
428	do {
429		name = xstrsep(&namelist, ",");
430		if (!name) {
431			xfree(namebase);
432			return (-1);
433		}
434	} while ((s = tcpconnect(name)) < 0);
435
436	if (s >= maxfd)
437		fatal("conalloc: fdno %d too high", s);
438	if (fdcon[s].c_status)
439		fatal("conalloc: attempt to reuse fdno %d", s);
440
441	fdcon[s].c_fd = s;
442	fdcon[s].c_status = CS_CON;
443	fdcon[s].c_namebase = namebase;
444	fdcon[s].c_name = name;
445	fdcon[s].c_namelist = namelist;
446	fdcon[s].c_output_name = xstrdup(oname);
447	fdcon[s].c_data = (char *) &fdcon[s].c_plen;
448	fdcon[s].c_len = 4;
449	fdcon[s].c_off = 0;
450	fdcon[s].c_keytype = keytype;
451	gettimeofday(&fdcon[s].c_tv, NULL);
452	fdcon[s].c_tv.tv_sec += timeout;
453	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
454	FD_SET(s, read_wait);
455	ncon++;
456	return (s);
457}
458
459static void
460confree(int s)
461{
462	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
463		fatal("confree: attempt to free bad fdno %d", s);
464	close(s);
465	xfree(fdcon[s].c_namebase);
466	xfree(fdcon[s].c_output_name);
467	if (fdcon[s].c_status == CS_KEYS)
468		xfree(fdcon[s].c_data);
469	fdcon[s].c_status = CS_UNUSED;
470	fdcon[s].c_keytype = 0;
471	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
472	FD_CLR(s, read_wait);
473	ncon--;
474}
475
476static void
477contouch(int s)
478{
479	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
480	gettimeofday(&fdcon[s].c_tv, NULL);
481	fdcon[s].c_tv.tv_sec += timeout;
482	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
483}
484
485static int
486conrecycle(int s)
487{
488	con *c = &fdcon[s];
489	int ret;
490
491	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
492	confree(s);
493	return (ret);
494}
495
496static void
497congreet(int s)
498{
499	int remote_major, remote_minor, n = 0;
500	char buf[256], *cp;
501	char remote_version[sizeof buf];
502	size_t bufsiz;
503	con *c = &fdcon[s];
504
505	bufsiz = sizeof(buf);
506	cp = buf;
507	while (bufsiz-- && (n = read(s, cp, 1)) == 1 && *cp != '\n') {
508		if (*cp == '\r')
509			*cp = '\n';
510		cp++;
511	}
512	if (n < 0) {
513		if (errno != ECONNREFUSED)
514			error("read (%s): %s", c->c_name, strerror(errno));
515		conrecycle(s);
516		return;
517	}
518	if (n == 0) {
519		error("%s: Connection closed by remote host", c->c_name);
520		conrecycle(s);
521		return;
522	}
523	if (*cp != '\n' && *cp != '\r') {
524		error("%s: bad greeting", c->c_name);
525		confree(s);
526		return;
527	}
528	*cp = '\0';
529	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
530	    &remote_major, &remote_minor, remote_version) == 3)
531		compat_datafellows(remote_version);
532	else
533		datafellows = 0;
534	if (c->c_keytype != KT_RSA1) {
535		if (!ssh2_capable(remote_major, remote_minor)) {
536			debug("%s doesn't support ssh2", c->c_name);
537			confree(s);
538			return;
539		}
540	} else if (remote_major != 1) {
541		debug("%s doesn't support ssh1", c->c_name);
542		confree(s);
543		return;
544	}
545	fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
546	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
547	    c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
548	    c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
549	if (atomicio(write, s, buf, n) != n) {
550		error("write (%s): %s", c->c_name, strerror(errno));
551		confree(s);
552		return;
553	}
554	if (c->c_keytype != KT_RSA1) {
555		keyprint(c, keygrab_ssh2(c));
556		confree(s);
557		return;
558	}
559	c->c_status = CS_SIZE;
560	contouch(s);
561}
562
563static void
564conread(int s)
565{
566	con *c = &fdcon[s];
567	int n;
568
569	if (c->c_status == CS_CON) {
570		congreet(s);
571		return;
572	}
573	n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
574	if (n < 0) {
575		error("read (%s): %s", c->c_name, strerror(errno));
576		confree(s);
577		return;
578	}
579	c->c_off += n;
580
581	if (c->c_off == c->c_len)
582		switch (c->c_status) {
583		case CS_SIZE:
584			c->c_plen = htonl(c->c_plen);
585			c->c_len = c->c_plen + 8 - (c->c_plen & 7);
586			c->c_off = 0;
587			c->c_data = xmalloc(c->c_len);
588			c->c_status = CS_KEYS;
589			break;
590		case CS_KEYS:
591			keyprint(c, keygrab_ssh1(c));
592			confree(s);
593			return;
594			break;
595		default:
596			fatal("conread: invalid status %d", c->c_status);
597			break;
598		}
599
600	contouch(s);
601}
602
603static void
604conloop(void)
605{
606	struct timeval seltime, now;
607	fd_set *r, *e;
608	con *c;
609	int i;
610
611	gettimeofday(&now, NULL);
612	c = TAILQ_FIRST(&tq);
613
614	if (c && (c->c_tv.tv_sec > now.tv_sec ||
615	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
616		seltime = c->c_tv;
617		seltime.tv_sec -= now.tv_sec;
618		seltime.tv_usec -= now.tv_usec;
619		if (seltime.tv_usec < 0) {
620			seltime.tv_usec += 1000000;
621			seltime.tv_sec--;
622		}
623	} else
624		seltime.tv_sec = seltime.tv_usec = 0;
625
626	r = xmalloc(read_wait_size);
627	memcpy(r, read_wait, read_wait_size);
628	e = xmalloc(read_wait_size);
629	memcpy(e, read_wait, read_wait_size);
630
631	while (select(maxfd, r, NULL, e, &seltime) == -1 &&
632	    (errno == EAGAIN || errno == EINTR))
633		;
634
635	for (i = 0; i < maxfd; i++) {
636		if (FD_ISSET(i, e)) {
637			error("%s: exception!", fdcon[i].c_name);
638			confree(i);
639		} else if (FD_ISSET(i, r))
640			conread(i);
641	}
642	xfree(r);
643	xfree(e);
644
645	c = TAILQ_FIRST(&tq);
646	while (c && (c->c_tv.tv_sec < now.tv_sec ||
647	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
648		int s = c->c_fd;
649
650		c = TAILQ_NEXT(c, c_link);
651		conrecycle(s);
652	}
653}
654
655static void
656do_host(char *host)
657{
658	char *name = strnnsep(&host, " \t\n");
659	int j;
660
661	if (name == NULL)
662		return;
663	for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
664		if (get_keytypes & j) {
665			while (ncon >= MAXCON)
666				conloop();
667			conalloc(name, *host ? host : name, j);
668		}
669	}
670}
671
672void
673fatal(const char *fmt,...)
674{
675	va_list args;
676
677	va_start(args, fmt);
678	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
679	va_end(args);
680	if (nonfatal_fatal)
681		longjmp(kexjmp, -1);
682	else
683		fatal_cleanup();
684}
685
686static void
687usage(void)
688{
689	fprintf(stderr, "usage: %s [-v46] [-p port] [-T timeout] [-f file]\n"
690	    "\t\t   [host | addrlist namelist] [...]\n",
691	    __progname);
692	exit(1);
693}
694
695int
696main(int argc, char **argv)
697{
698	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
699	int opt, fopt_count = 0;
700	char *tname;
701
702	extern int optind;
703	extern char *optarg;
704
705	__progname = get_progname(argv[0]);
706	init_rng();
707	seed_rng();
708	TAILQ_INIT(&tq);
709
710	if (argc <= 1)
711		usage();
712
713	while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
714		switch (opt) {
715		case 'p':
716			ssh_port = a2port(optarg);
717			if (ssh_port == 0) {
718				fprintf(stderr, "Bad port '%s'\n", optarg);
719				exit(1);
720			}
721			break;
722		case 'T':
723			timeout = convtime(optarg);
724			if (timeout == -1 || timeout == 0) {
725				fprintf(stderr, "Bad timeout '%s'\n", optarg);
726				usage();
727			}
728			break;
729		case 'v':
730			if (!debug_flag) {
731				debug_flag = 1;
732				log_level = SYSLOG_LEVEL_DEBUG1;
733			}
734			else if (log_level < SYSLOG_LEVEL_DEBUG3)
735				log_level++;
736			else
737				fatal("Too high debugging level.");
738			break;
739		case 'f':
740			if (strcmp(optarg, "-") == 0)
741				optarg = NULL;
742			argv[fopt_count++] = optarg;
743			break;
744		case 't':
745			get_keytypes = 0;
746			tname = strtok(optarg, ",");
747			while (tname) {
748				int type = key_type_from_name(tname);
749				switch (type) {
750				case KEY_RSA1:
751					get_keytypes |= KT_RSA1;
752					break;
753				case KEY_DSA:
754					get_keytypes |= KT_DSA;
755					break;
756				case KEY_RSA:
757					get_keytypes |= KT_RSA;
758					break;
759				case KEY_UNSPEC:
760					fatal("unknown key type %s", tname);
761				}
762				tname = strtok(NULL, ",");
763			}
764			break;
765		case '4':
766			IPv4or6 = AF_INET;
767			break;
768		case '6':
769			IPv4or6 = AF_INET6;
770			break;
771		case '?':
772		default:
773			usage();
774		}
775	}
776	if (optind == argc && !fopt_count)
777		usage();
778
779	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
780
781	maxfd = fdlim_get(1);
782	if (maxfd < 0)
783		fatal("%s: fdlim_get: bad value", __progname);
784	if (maxfd > MAXMAXFD)
785		maxfd = MAXMAXFD;
786	if (MAXCON <= 0)
787		fatal("%s: not enough file descriptors", __progname);
788	if (maxfd > fdlim_get(0))
789		fdlim_set(maxfd);
790	fdcon = xmalloc(maxfd * sizeof(con));
791	memset(fdcon, 0, maxfd * sizeof(con));
792
793	read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
794	read_wait = xmalloc(read_wait_size);
795	memset(read_wait, 0, read_wait_size);
796
797	if (fopt_count) {
798		Linebuf *lb;
799		char *line;
800		int j;
801
802		for (j = 0; j < fopt_count; j++) {
803			lb = Linebuf_alloc(argv[j], error);
804			if (!lb)
805				continue;
806			while ((line = Linebuf_getline(lb)) != NULL)
807				do_host(line);
808			Linebuf_free(lb);
809		}
810	}
811
812	while (optind < argc)
813		do_host(argv[optind++]);
814
815	while (ncon > 0)
816		conloop();
817
818	return (0);
819}
820