[gssapi-openssh.git] / openssh / ssh-keyscan.c

/*
 * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
 *
 * Modification and redistribution in source and binary forms is
 * permitted provided that due credit is given to the author and the
 * OpenBSD project by leaving this copyright notice intact.
 */

#include "includes.h"
RCSID("$OpenBSD: ssh-keyscan.c,v 1.36 2002/06/16 21:30:58 itojun Exp $");

#include "openbsd-compat/fake-queue.h"

#include <openssl/bn.h>

#include <setjmp.h>
#include "xmalloc.h"
#include "ssh.h"
#include "ssh1.h"
#include "key.h"
#include "kex.h"
#include "compat.h"
#include "myproposal.h"
#include "packet.h"
#include "dispatch.h"
#include "buffer.h"
#include "bufaux.h"
#include "log.h"
#include "atomicio.h"
#include "misc.h"
#include "pathnames.h"

/* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
   Default value is AF_UNSPEC means both IPv4 and IPv6. */
#ifdef IPV4_DEFAULT
int IPv4or6 = AF_INET;
#else
int IPv4or6 = AF_UNSPEC;
#endif

int ssh_port = SSH_DEFAULT_PORT;

#define KT_RSA1	1
#define KT_DSA	2
#define KT_RSA	4

int get_keytypes = KT_RSA1;	/* Get only RSA1 keys by default */

#define MAXMAXFD 256

/* The number of seconds after which to give up on a TCP connection */
int timeout = 5;

int maxfd;
#define MAXCON (maxfd - 10)

#ifdef HAVE___PROGNAME
extern char *__progname;
#else
char *__progname;
#endif
fd_set *read_wait;
size_t read_wait_size;
int ncon;
int nonfatal_fatal = 0;
jmp_buf kexjmp;
Key *kexjmp_key;

/*
 * Keep a connection structure for each file descriptor.  The state
 * associated with file descriptor n is held in fdcon[n].
 */
typedef struct Connection {
	u_char c_status;	/* State of connection on this file desc. */
#define CS_UNUSED 0		/* File descriptor unused */
#define CS_CON 1		/* Waiting to connect/read greeting */
#define CS_SIZE 2		/* Waiting to read initial packet size */
#define CS_KEYS 3		/* Waiting to read public key packet */
	int c_fd;		/* Quick lookup: c->c_fd == c - fdcon */
	int c_plen;		/* Packet length field for ssh packet */
	int c_len;		/* Total bytes which must be read. */
	int c_off;		/* Length of data read so far. */
	int c_keytype;		/* Only one of KT_RSA1, KT_DSA, or KT_RSA */
	char *c_namebase;	/* Address to free for c_name and c_namelist */
	char *c_name;		/* Hostname of connection for errors */
	char *c_namelist;	/* Pointer to other possible addresses */
	char *c_output_name;	/* Hostname of connection for output */
	char *c_data;		/* Data read from this fd */
	Kex *c_kex;		/* The key-exchange struct for ssh2 */
	struct timeval c_tv;	/* Time at which connection gets aborted */
	TAILQ_ENTRY(Connection) c_link;	/* List of connections in timeout order. */
} con;

TAILQ_HEAD(conlist, Connection) tq;	/* Timeout Queue */
con *fdcon;

/*
 *  This is just a wrapper around fgets() to make it usable.
 */

/* Stress-test.  Increase this later. */
#define LINEBUF_SIZE 16

typedef struct {
	char *buf;
	u_int size;
	int lineno;
	const char *filename;
	FILE *stream;
	void (*errfun) (const char *,...);
} Linebuf;

static Linebuf *
Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
{
	Linebuf *lb;

	if (!(lb = malloc(sizeof(*lb)))) {
		if (errfun)
			(*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
		return (NULL);
	}
	if (filename) {
		lb->filename = filename;
		if (!(lb->stream = fopen(filename, "r"))) {
			xfree(lb);
			if (errfun)
				(*errfun) ("%s: %s\n", filename, strerror(errno));
			return (NULL);
		}
	} else {
		lb->filename = "(stdin)";
		lb->stream = stdin;
	}

	if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
		if (errfun)
			(*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
		xfree(lb);
		return (NULL);
	}
	lb->errfun = errfun;
	lb->lineno = 0;
	return (lb);
}

static void
Linebuf_free(Linebuf * lb)
{
	fclose(lb->stream);
	xfree(lb->buf);
	xfree(lb);
}

#if 0
static void
Linebuf_restart(Linebuf * lb)
{
	clearerr(lb->stream);
	rewind(lb->stream);
	lb->lineno = 0;
}

static int
Linebuf_lineno(Linebuf * lb)
{
	return (lb->lineno);
}
#endif

static char *
Linebuf_getline(Linebuf * lb)
{
	int n = 0;

	lb->lineno++;
	for (;;) {
		/* Read a line */
		if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
			if (ferror(lb->stream) && lb->errfun)
				(*lb->errfun) ("%s: %s\n", lb->filename,
				    strerror(errno));
			return (NULL);
		}
		n = strlen(lb->buf);

		/* Return it or an error if it fits */
		if (n > 0 && lb->buf[n - 1] == '\n') {
			lb->buf[n - 1] = '\0';
			return (lb->buf);
		}
		if (n != lb->size - 1) {
			if (lb->errfun)
				(*lb->errfun) ("%s: skipping incomplete last line\n",
				    lb->filename);
			return (NULL);
		}
		/* Double the buffer if we need more space */
		if (!(lb->buf = realloc(lb->buf, (lb->size *= 2)))) {
			if (lb->errfun)
				(*lb->errfun) ("linebuf (%s): realloc failed\n",
				    lb->filename);
			return (NULL);
		}
	}
}

static int
fdlim_get(int hard)
{
#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
	struct rlimit rlfd;

	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
		return (-1);
	if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
		return 10000;
	else
		return hard ? rlfd.rlim_max : rlfd.rlim_cur;
#elif defined (HAVE_SYSCONF)
	return sysconf (_SC_OPEN_MAX);
#else
	return 10000;
#endif
}

static int
fdlim_set(int lim)
{
#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
	struct rlimit rlfd;
#endif
	if (lim <= 0)
		return (-1);
#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
		return (-1);
	rlfd.rlim_cur = lim;
	if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
		return (-1);
#elif defined (HAVE_SETDTABLESIZE)
	setdtablesize(lim);
#endif
	return (0);
}

/*
 * This is an strsep function that returns a null field for adjacent
 * separators.  This is the same as the 4.4BSD strsep, but different from the
 * one in the GNU libc.
 */
static char *
xstrsep(char **str, const char *delim)
{
	char *s, *e;

	if (!**str)
		return (NULL);

	s = *str;
	e = s + strcspn(s, delim);

	if (*e != '\0')
		*e++ = '\0';
	*str = e;

	return (s);
}

/*
 * Get the next non-null token (like GNU strsep).  Strsep() will return a
 * null token for two adjacent separators, so we may have to loop.
 */
static char *
strnnsep(char **stringp, char *delim)
{
	char *tok;

	do {
		tok = xstrsep(stringp, delim);
	} while (tok && *tok == '\0');
	return (tok);
}

static Key *
keygrab_ssh1(con *c)
{
	static Key *rsa;
	static Buffer msg;

	if (rsa == NULL) {
		buffer_init(&msg);
		rsa = key_new(KEY_RSA1);
	}
	buffer_append(&msg, c->c_data, c->c_plen);
	buffer_consume(&msg, 8 - (c->c_plen & 7));	/* padding */
	if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
		error("%s: invalid packet type", c->c_name);
		buffer_clear(&msg);
		return NULL;
	}
	buffer_consume(&msg, 8);		/* cookie */

	/* server key */
	(void) buffer_get_int(&msg);
	buffer_get_bignum(&msg, rsa->rsa->e);
	buffer_get_bignum(&msg, rsa->rsa->n);

	/* host key */
	(void) buffer_get_int(&msg);
	buffer_get_bignum(&msg, rsa->rsa->e);
	buffer_get_bignum(&msg, rsa->rsa->n);

	buffer_clear(&msg);

	return (rsa);
}

static int
hostjump(Key *hostkey)
{
	kexjmp_key = hostkey;
	longjmp(kexjmp, 1);
}

static int
ssh2_capable(int remote_major, int remote_minor)
{
	switch (remote_major) {
	case 1:
		if (remote_minor == 99)
			return 1;
		break;
	case 2:
		return 1;
	default:
		break;
	}
	return 0;
}

static Key *
keygrab_ssh2(con *c)
{
	int j;

	packet_set_connection(c->c_fd, c->c_fd);
	enable_compat20();
	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
	    "ssh-dss": "ssh-rsa";
	c->c_kex = kex_setup(myproposal);
	c->c_kex->verify_host_key = hostjump;

	if (!(j = setjmp(kexjmp))) {
		nonfatal_fatal = 1;
		dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
		fprintf(stderr, "Impossible! dispatch_run() returned!\n");
		exit(1);
	}
	nonfatal_fatal = 0;
	xfree(c->c_kex);
	c->c_kex = NULL;
	packet_close();

	return j < 0? NULL : kexjmp_key;
}

static void
keyprint(con *c, Key *key)
{
	if (!key)
		return;

	fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
	key_write(key, stdout);
	fputs("\n", stdout);
}

static int
tcpconnect(char *host)
{
	struct addrinfo hints, *ai, *aitop;
	char strport[NI_MAXSERV];
	int gaierr, s = -1;

	snprintf(strport, sizeof strport, "%d", ssh_port);
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = IPv4or6;
	hints.ai_socktype = SOCK_STREAM;
	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
		fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
	for (ai = aitop; ai; ai = ai->ai_next) {
		s = socket(ai->ai_family, SOCK_STREAM, 0);
		if (s < 0) {
			error("socket: %s", strerror(errno));
			continue;
		}
		if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
			fatal("F_SETFL: %s", strerror(errno));
		if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
		    errno != EINPROGRESS)
			error("connect (`%s'): %s", host, strerror(errno));
		else
			break;
		close(s);
		s = -1;
	}
	freeaddrinfo(aitop);
	return s;
}

static int
conalloc(char *iname, char *oname, int keytype)
{
	int s;
	char *namebase, *name, *namelist;

	namebase = namelist = xstrdup(iname);

	do {
		name = xstrsep(&namelist, ",");
		if (!name) {
			xfree(namebase);
			return (-1);
		}
	} while ((s = tcpconnect(name)) < 0);

	if (s >= maxfd)
		fatal("conalloc: fdno %d too high", s);
	if (fdcon[s].c_status)
		fatal("conalloc: attempt to reuse fdno %d", s);

	fdcon[s].c_fd = s;
	fdcon[s].c_status = CS_CON;
	fdcon[s].c_namebase = namebase;
	fdcon[s].c_name = name;
	fdcon[s].c_namelist = namelist;
	fdcon[s].c_output_name = xstrdup(oname);
	fdcon[s].c_data = (char *) &fdcon[s].c_plen;
	fdcon[s].c_len = 4;
	fdcon[s].c_off = 0;
	fdcon[s].c_keytype = keytype;
	gettimeofday(&fdcon[s].c_tv, NULL);
	fdcon[s].c_tv.tv_sec += timeout;
	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
	FD_SET(s, read_wait);
	ncon++;
	return (s);
}

static void
confree(int s)
{
	if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
		fatal("confree: attempt to free bad fdno %d", s);
	close(s);
	xfree(fdcon[s].c_namebase);
	xfree(fdcon[s].c_output_name);
	if (fdcon[s].c_status == CS_KEYS)
		xfree(fdcon[s].c_data);
	fdcon[s].c_status = CS_UNUSED;
	fdcon[s].c_keytype = 0;
	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
	FD_CLR(s, read_wait);
	ncon--;
}

static void
contouch(int s)
{
	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
	gettimeofday(&fdcon[s].c_tv, NULL);
	fdcon[s].c_tv.tv_sec += timeout;
	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
}

static int
conrecycle(int s)
{
	int ret;
	con *c = &fdcon[s];

	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
	confree(s);
	return (ret);
}

static void
congreet(int s)
{
	char buf[256], *cp;
	char remote_version[sizeof buf];
	size_t bufsiz;
	int remote_major, remote_minor, n = 0;
	con *c = &fdcon[s];

	bufsiz = sizeof(buf);
	cp = buf;
	while (bufsiz-- && (n = read(s, cp, 1)) == 1 && *cp != '\n') {
		if (*cp == '\r')
			*cp = '\n';
		cp++;
	}
	if (n < 0) {
		if (errno != ECONNREFUSED)
			error("read (%s): %s", c->c_name, strerror(errno));
		conrecycle(s);
		return;
	}
	if (n == 0) {
		error("%s: Connection closed by remote host", c->c_name);
		conrecycle(s);
		return;
	}
	if (*cp != '\n' && *cp != '\r') {
		error("%s: bad greeting", c->c_name);
		confree(s);
		return;
	}
	*cp = '\0';
	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
	    &remote_major, &remote_minor, remote_version) == 3)
		compat_datafellows(remote_version);
	else
		datafellows = 0;
	if (c->c_keytype != KT_RSA1) {
		if (!ssh2_capable(remote_major, remote_minor)) {
			debug("%s doesn't support ssh2", c->c_name);
			confree(s);
			return;
		}
	} else if (remote_major != 1) {
		debug("%s doesn't support ssh1", c->c_name);
		confree(s);
		return;
	}
	fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
	    c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
	    c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
	if (atomicio(write, s, buf, n) != n) {
		error("write (%s): %s", c->c_name, strerror(errno));
		confree(s);
		return;
	}
	if (c->c_keytype != KT_RSA1) {
		keyprint(c, keygrab_ssh2(c));
		confree(s);
		return;
	}
	c->c_status = CS_SIZE;
	contouch(s);
}

static void
conread(int s)
{
	int n;
	con *c = &fdcon[s];

	if (c->c_status == CS_CON) {
		congreet(s);
		return;
	}
	n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
	if (n < 0) {
		error("read (%s): %s", c->c_name, strerror(errno));
		confree(s);
		return;
	}
	c->c_off += n;

	if (c->c_off == c->c_len)
		switch (c->c_status) {
		case CS_SIZE:
			c->c_plen = htonl(c->c_plen);
			c->c_len = c->c_plen + 8 - (c->c_plen & 7);
			c->c_off = 0;
			c->c_data = xmalloc(c->c_len);
			c->c_status = CS_KEYS;
			break;
		case CS_KEYS:
			keyprint(c, keygrab_ssh1(c));
			confree(s);
			return;
			break;
		default:
			fatal("conread: invalid status %d", c->c_status);
			break;
		}

	contouch(s);
}

static void
conloop(void)
{
	fd_set *r, *e;
	struct timeval seltime, now;
	int i;
	con *c;

	gettimeofday(&now, NULL);
	c = TAILQ_FIRST(&tq);

	if (c && (c->c_tv.tv_sec > now.tv_sec ||
	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
		seltime = c->c_tv;
		seltime.tv_sec -= now.tv_sec;
		seltime.tv_usec -= now.tv_usec;
		if (seltime.tv_usec < 0) {
			seltime.tv_usec += 1000000;
			seltime.tv_sec--;
		}
	} else
		seltime.tv_sec = seltime.tv_usec = 0;

	r = xmalloc(read_wait_size);
	memcpy(r, read_wait, read_wait_size);
	e = xmalloc(read_wait_size);
	memcpy(e, read_wait, read_wait_size);

	while (select(maxfd, r, NULL, e, &seltime) == -1 &&
	    (errno == EAGAIN || errno == EINTR))
		;

	for (i = 0; i < maxfd; i++) {
		if (FD_ISSET(i, e)) {
			error("%s: exception!", fdcon[i].c_name);
			confree(i);
		} else if (FD_ISSET(i, r))
			conread(i);
	}
	xfree(r);
	xfree(e);

	c = TAILQ_FIRST(&tq);
	while (c && (c->c_tv.tv_sec < now.tv_sec ||
	    (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
		int s = c->c_fd;

		c = TAILQ_NEXT(c, c_link);
		conrecycle(s);
	}
}

static void
do_host(char *host)
{
	char *name = strnnsep(&host, " \t\n");
	int j;

	if (name == NULL)
		return;
	for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
		if (get_keytypes & j) {
			while (ncon >= MAXCON)
				conloop();
			conalloc(name, *host ? host : name, j);
		}
	}
}

void
fatal(const char *fmt,...)
{
	va_list args;
	va_start(args, fmt);
	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
	va_end(args);
	if (nonfatal_fatal)
		longjmp(kexjmp, -1);
	else
		fatal_cleanup();
}

static void
usage(void)
{
	fprintf(stderr, "Usage: %s [options] host ...\n",
	    __progname);
	fprintf(stderr, "Options:\n");
	fprintf(stderr, "  -f file     Read hosts or addresses from file.\n");
	fprintf(stderr, "  -p port     Connect to the specified port.\n");
	fprintf(stderr, "  -t keytype  Specify the host key type.\n");
	fprintf(stderr, "  -T timeout  Set connection timeout.\n");
	fprintf(stderr, "  -v          Verbose; display verbose debugging messages.\n");
	fprintf(stderr, "  -4          Use IPv4 only.\n");
	fprintf(stderr, "  -6          Use IPv6 only.\n");
	exit(1);
}

int
main(int argc, char **argv)
{
	int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
	int opt, fopt_count = 0;
	char *tname;

	extern int optind;
	extern char *optarg;

	__progname = get_progname(argv[0]);
	init_pathnames();
	init_rng();
	seed_rng();
	TAILQ_INIT(&tq);

	if (argc <= 1)
		usage();

	while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
		switch (opt) {
		case 'p':
			ssh_port = a2port(optarg);
			if (ssh_port == 0) {
				fprintf(stderr, "Bad port '%s'\n", optarg);
				exit(1);
			}
			break;
		case 'T':
			timeout = atoi(optarg);
			if (timeout <= 0)
				usage();
			break;
		case 'v':
			if (!debug_flag) {
				debug_flag = 1;
				log_level = SYSLOG_LEVEL_DEBUG1;
			}
			else if (log_level < SYSLOG_LEVEL_DEBUG3)
				log_level++;
			else
				fatal("Too high debugging level.");
			break;
		case 'f':
			if (strcmp(optarg, "-") == 0)
				optarg = NULL;
			argv[fopt_count++] = optarg;
			break;
		case 't':
			get_keytypes = 0;
			tname = strtok(optarg, ",");
			while (tname) {
				int type = key_type_from_name(tname);
				switch (type) {
				case KEY_RSA1:
					get_keytypes |= KT_RSA1;
					break;
				case KEY_DSA:
					get_keytypes |= KT_DSA;
					break;
				case KEY_RSA:
					get_keytypes |= KT_RSA;
					break;
				case KEY_UNSPEC:
					fatal("unknown key type %s", tname);
				}
				tname = strtok(NULL, ",");
			}
			break;
		case '4':
			IPv4or6 = AF_INET;
			break;
		case '6':
			IPv4or6 = AF_INET6;
			break;
		case '?':
		default:
			usage();
		}
	}
	if (optind == argc && !fopt_count)
		usage();

	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);

	maxfd = fdlim_get(1);
	if (maxfd < 0)
		fatal("%s: fdlim_get: bad value", __progname);
	if (maxfd > MAXMAXFD)
		maxfd = MAXMAXFD;
	if (MAXCON <= 0)
		fatal("%s: not enough file descriptors", __progname);
	if (maxfd > fdlim_get(0))
		fdlim_set(maxfd);
	fdcon = xmalloc(maxfd * sizeof(con));
	memset(fdcon, 0, maxfd * sizeof(con));

	read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
	read_wait = xmalloc(read_wait_size);
	memset(read_wait, 0, read_wait_size);

	if (fopt_count) {
		Linebuf *lb;
		char *line;
		int j;

		for (j = 0; j < fopt_count; j++) {
			lb = Linebuf_alloc(argv[j], error);
			if (!lb)
				continue;
			while ((line = Linebuf_getline(lb)) != NULL)
				do_host(line);
			Linebuf_free(lb);
		}
	}

	while (optind < argc)
		do_host(argv[optind++]);

	while (ncon > 0)
		conloop();

	return (0);
}
Commit	Line	Data
3c0ef626	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"
ff2d7a98	10	RCSID("$OpenBSD: ssh-keyscan.c,v 1.36 2002/06/16 21:30:58 itojun Exp $");
3c0ef626	11
3c0ef626	12	#include "openbsd-compat/fake-queue.h"
3c0ef626	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"
2b8f6339	31	#include "pathnames.h"
3c0ef626	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
	36	int IPv4or6 = AF_INET;
	37	#else
	38	int IPv4or6 = AF_UNSPEC;
	39	#endif
	40
	41	int ssh_port = SSH_DEFAULT_PORT;
	42
	43	#define KT_RSA1 1
	44	#define KT_DSA 2
	45	#define KT_RSA 4
	46
	47	int 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 */
	52	int timeout = 5;
	53
	54	int maxfd;
	55	#define MAXCON (maxfd - 10)
	56
	57	#ifdef HAVE___PROGNAME
	58	extern char *__progname;
	59	#else
	60	char *__progname;
	61	#endif
	62	fd_set *read_wait;
	63	size_t read_wait_size;
	64	int ncon;
	65	int nonfatal_fatal = 0;
	66	jmp_buf kexjmp;
	67	Key *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	*/
	73	typedef 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
	94	TAILQ_HEAD(conlist, Connection) tq; /* Timeout Queue */
	95	con *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
104	typedef 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
113	static Linebuf *
114	Linebuf_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", lb->filename);
121	return (NULL);
122	}
123	if (filename) {
124	lb->filename = filename;
125	if (!(lb->stream = fopen(filename, "r"))) {
126	xfree(lb);
127	if (errfun)
128	(*errfun) ("%s: %s\n", filename, strerror(errno));
129	return (NULL);
130	}
131	} else {
132	lb->filename = "(stdin)";
133	lb->stream = stdin;
134	}
135
136	if (!(lb->buf = malloc(lb->size = LINEBUF_SIZE))) {
137	if (errfun)
138	(*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
139	xfree(lb);
140	return (NULL);
141	}
142	lb->errfun = errfun;
143	lb->lineno = 0;
144	return (lb);
145	}
146
147	static void
148	Linebuf_free(Linebuf * lb)
149	{
150	fclose(lb->stream);
151	xfree(lb->buf);
152	xfree(lb);
153	}
154
155	#if 0
156	static void
157	Linebuf_restart(Linebuf * lb)
158	{
159	clearerr(lb->stream);
160	rewind(lb->stream);
161	lb->lineno = 0;
162	}
163
164	static int
165	Linebuf_lineno(Linebuf * lb)
166	{
167	return (lb->lineno);
168	}
169	#endif
170
171	static char *
172	Linebuf_getline(Linebuf * lb)
173	{
174	int n = 0;
175
176	lb->lineno++;
177	for (;;) {
178	/* Read a line */
179	if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
180	if (ferror(lb->stream) && lb->errfun)
181	(*lb->errfun) ("%s: %s\n", lb->filename,
182	strerror(errno));
183	return (NULL);
184	}
185	n = strlen(lb->buf);
186
187	/* Return it or an error if it fits */
188	if (n > 0 && lb->buf[n - 1] == '\n') {
189	lb->buf[n - 1] = '\0';
190	return (lb->buf);
191	}
192	if (n != lb->size - 1) {
193	if (lb->errfun)
194	(*lb->errfun) ("%s: skipping incomplete last line\n",
195	lb->filename);
196	return (NULL);
197	}
198	/* Double the buffer if we need more space */
199	if (!(lb->buf = realloc(lb->buf, (lb->size *= 2)))) {
200	if (lb->errfun)
201	(*lb->errfun) ("linebuf (%s): realloc failed\n",
202	lb->filename);
203	return (NULL);
204	}
205	}
206	}
207
208	static int
209	fdlim_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 10000;
218	else
219	return hard ? rlfd.rlim_max : rlfd.rlim_cur;
220	#elif defined (HAVE_SYSCONF)
221	return sysconf (_SC_OPEN_MAX);
222	#else
223	return 10000;
224	#endif
225	}
226
227	static int
228	fdlim_set(int lim)
229	{
230	#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
231	struct rlimit rlfd;
232	#endif
233	if (lim <= 0)
234	return (-1);
235	#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
236	if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
237	return (-1);
238	rlfd.rlim_cur = lim;
239	if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
240	return (-1);
241	#elif defined (HAVE_SETDTABLESIZE)
242	setdtablesize(lim);
243	#endif
244	return (0);
245	}
246
247	/*
248	* This is an strsep function that returns a null field for adjacent
249	* separators. This is the same as the 4.4BSD strsep, but different from the
250	* one in the GNU libc.
251	*/
252	static char *
253	xstrsep(char *str, const char delim)
254	{
255	char s, e;
256
257	if (!**str)
258	return (NULL);
259
260	s = *str;
261	e = s + strcspn(s, delim);
262
263	if (*e != '\0')
264	*e++ = '\0';
265	*str = e;
266
267	return (s);
268	}
269
270	/*
271	* Get the next non-null token (like GNU strsep). Strsep() will return a
272	* null token for two adjacent separators, so we may have to loop.
273	*/
274	static char *
275	strnnsep(char *stringp, char delim)
276	{
277	char *tok;
278
279	do {
280	tok = xstrsep(stringp, delim);
281	} while (tok && *tok == '\0');
282	return (tok);
283	}
284
285	static Key *
286	keygrab_ssh1(con *c)
287	{
288	static Key *rsa;
289	static Buffer msg;
290
291	if (rsa == NULL) {
292	buffer_init(&msg);
293	rsa = key_new(KEY_RSA1);
294	}
295	buffer_append(&msg, c->c_data, c->c_plen);
296	buffer_consume(&msg, 8 - (c->c_plen & 7)); /* padding */
297	if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
298	error("%s: invalid packet type", c->c_name);
299	buffer_clear(&msg);
300	return NULL;
301	}
302	buffer_consume(&msg, 8); /* cookie */
303
304	/* server key */
305	(void) buffer_get_int(&msg);
306	buffer_get_bignum(&msg, rsa->rsa->e);
307	buffer_get_bignum(&msg, rsa->rsa->n);
308
309	/* host key */
310	(void) buffer_get_int(&msg);
311	buffer_get_bignum(&msg, rsa->rsa->e);
312	buffer_get_bignum(&msg, rsa->rsa->n);
313
314	buffer_clear(&msg);
315
316	return (rsa);
317	}
318
319	static int
320	hostjump(Key *hostkey)
321	{
322	kexjmp_key = hostkey;
323	longjmp(kexjmp, 1);
324	}
325
326	static int
327	ssh2_capable(int remote_major, int remote_minor)
328	{
329	switch (remote_major) {
330	case 1:
331	if (remote_minor == 99)
332	return 1;
333	break;
334	case 2:
335	return 1;
336	default:
337	break;
338	}
339	return 0;
340	}
341
342	static Key *
343	keygrab_ssh2(con *c)
344	{
345	int j;
346
347	packet_set_connection(c->c_fd, c->c_fd);
348	enable_compat20();
349	myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
350	"ssh-dss": "ssh-rsa";
351	c->c_kex = kex_setup(myproposal);
352	c->c_kex->verify_host_key = hostjump;
353
354	if (!(j = setjmp(kexjmp))) {
355	nonfatal_fatal = 1;
356	dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
357	fprintf(stderr, "Impossible! dispatch_run() returned!\n");
358	exit(1);
359	}
360	nonfatal_fatal = 0;
361	xfree(c->c_kex);
362	c->c_kex = NULL;
363	packet_close();
364
365	return j < 0? NULL : kexjmp_key;
366	}
367
368	static void
369	keyprint(con c, Key key)
370	{
371	if (!key)
372	return;
373
374	fprintf(stdout, "%s ", c->c_output_name ? c->c_output_name : c->c_name);
375	key_write(key, stdout);
376	fputs("\n", stdout);
377	}
378
379	static int
380	tcpconnect(char *host)
381	{
382	struct addrinfo hints, ai, aitop;
383	char strport[NI_MAXSERV];
384	int gaierr, s = -1;
385
386	snprintf(strport, sizeof strport, "%d", ssh_port);
387	memset(&hints, 0, sizeof(hints));
388	hints.ai_family = IPv4or6;
389	hints.ai_socktype = SOCK_STREAM;
390	if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
391	fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
392	for (ai = aitop; ai; ai = ai->ai_next) {
393	s = socket(ai->ai_family, SOCK_STREAM, 0);
394	if (s < 0) {
395	error("socket: %s", strerror(errno));
396	continue;
397	}
398	if (fcntl(s, F_SETFL, O_NONBLOCK) < 0)
399	fatal("F_SETFL: %s", strerror(errno));
400	if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
401	errno != EINPROGRESS)
402	error("connect (`%s'): %s", host, strerror(errno));
403	else
404	break;
405	close(s);
406	s = -1;
407	}
408	freeaddrinfo(aitop);
409	return s;
410	}
411
412	static int
413	conalloc(char iname, char oname, int keytype)
414	{
415	int s;
416	char namebase, name, *namelist;
417
418	namebase = namelist = xstrdup(iname);
419
420	do {
421	name = xstrsep(&namelist, ",");
422	if (!name) {
423	xfree(namebase);
424	return (-1);
425	}
426	} while ((s = tcpconnect(name)) < 0);
427
428	if (s >= maxfd)
429	fatal("conalloc: fdno %d too high", s);
430	if (fdcon[s].c_status)
431	fatal("conalloc: attempt to reuse fdno %d", s);
432
433	fdcon[s].c_fd = s;
434	fdcon[s].c_status = CS_CON;
435	fdcon[s].c_namebase = namebase;
436	fdcon[s].c_name = name;
437	fdcon[s].c_namelist = namelist;
438	fdcon[s].c_output_name = xstrdup(oname);
439	fdcon[s].c_data = (char *) &fdcon[s].c_plen;
440	fdcon[s].c_len = 4;
441	fdcon[s].c_off = 0;
442	fdcon[s].c_keytype = keytype;
443	gettimeofday(&fdcon[s].c_tv, NULL);
444	fdcon[s].c_tv.tv_sec += timeout;
445	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
446	FD_SET(s, read_wait);
447	ncon++;
448	return (s);
449	}
450
451	static void
452	confree(int s)
453	{
454	if (s >= maxfd \|\| fdcon[s].c_status == CS_UNUSED)
455	fatal("confree: attempt to free bad fdno %d", s);
456	close(s);
457	xfree(fdcon[s].c_namebase);
458	xfree(fdcon[s].c_output_name);
459	if (fdcon[s].c_status == CS_KEYS)
460	xfree(fdcon[s].c_data);
461	fdcon[s].c_status = CS_UNUSED;
462	fdcon[s].c_keytype = 0;
463	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
464	FD_CLR(s, read_wait);
465	ncon--;
466	}
467
468	static void
469	contouch(int s)
470	{
471	TAILQ_REMOVE(&tq, &fdcon[s], c_link);
472	gettimeofday(&fdcon[s].c_tv, NULL);
473	fdcon[s].c_tv.tv_sec += timeout;
474	TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
475	}
476
477	static int
478	conrecycle(int s)
479	{
480	int ret;
481	con *c = &fdcon[s];
482
483	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
484	confree(s);
485	return (ret);
486	}
487
488	static void
489	congreet(int s)
490	{
491	char buf[256], *cp;
e9a17296	492	char remote_version[sizeof buf];
3c0ef626	493	size_t bufsiz;
e9a17296	494	int remote_major, remote_minor, n = 0;
3c0ef626	495	con *c = &fdcon[s];
	496
	497	bufsiz = sizeof(buf);
	498	cp = buf;
	499	while (bufsiz-- && (n = read(s, cp, 1)) == 1 && *cp != '\n') {
	500	if (*cp == '\r')
	501	*cp = '\n';
	502	cp++;
	503	}
	504	if (n < 0) {
	505	if (errno != ECONNREFUSED)
	506	error("read (%s): %s", c->c_name, strerror(errno));
	507	conrecycle(s);
	508	return;
	509	}
e9a17296	510	if (n == 0) {
	511	error("%s: Connection closed by remote host", c->c_name);
	512	conrecycle(s);
	513	return;
	514	}
3c0ef626	515	if (cp != '\n' && cp != '\r') {
	516	error("%s: bad greeting", c->c_name);
	517	confree(s);
	518	return;
	519	}
	520	*cp = '\0';
e9a17296	521	if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
	522	&remote_major, &remote_minor, remote_version) == 3)
	523	compat_datafellows(remote_version);
	524	else
	525	datafellows = 0;
3c0ef626	526	if (c->c_keytype != KT_RSA1) {
3c0ef626	527	if (!ssh2_capable(remote_major, remote_minor)) {
	528	debug("%s doesn't support ssh2", c->c_name);
	529	confree(s);
	530	return;
	531	}
e9a17296	532	} else if (remote_major != 1) {
	533	debug("%s doesn't support ssh1", c->c_name);
	534	confree(s);
	535	return;
3c0ef626	536	}
	537	fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
	538	n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
	539	c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
	540	c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
	541	if (atomicio(write, s, buf, n) != n) {
	542	error("write (%s): %s", c->c_name, strerror(errno));
	543	confree(s);
	544	return;
	545	}
	546	if (c->c_keytype != KT_RSA1) {
	547	keyprint(c, keygrab_ssh2(c));
	548	confree(s);
	549	return;
	550	}
	551	c->c_status = CS_SIZE;
	552	contouch(s);
	553	}
	554
	555	static void
	556	conread(int s)
	557	{
	558	int n;
	559	con *c = &fdcon[s];
	560
	561	if (c->c_status == CS_CON) {
	562	congreet(s);
	563	return;
	564	}
	565	n = read(s, c->c_data + c->c_off, c->c_len - c->c_off);
	566	if (n < 0) {
	567	error("read (%s): %s", c->c_name, strerror(errno));
	568	confree(s);
	569	return;
	570	}
	571	c->c_off += n;
	572
	573	if (c->c_off == c->c_len)
	574	switch (c->c_status) {
	575	case CS_SIZE:
	576	c->c_plen = htonl(c->c_plen);
	577	c->c_len = c->c_plen + 8 - (c->c_plen & 7);
	578	c->c_off = 0;
	579	c->c_data = xmalloc(c->c_len);
	580	c->c_status = CS_KEYS;
	581	break;
	582	case CS_KEYS:
	583	keyprint(c, keygrab_ssh1(c));
	584	confree(s);
	585	return;
	586	break;
	587	default:
	588	fatal("conread: invalid status %d", c->c_status);
	589	break;
	590	}
	591
	592	contouch(s);
	593	}
	594
	595	static void
	596	conloop(void)
	597	{
	598	fd_set r, e;
	599	struct timeval seltime, now;
600	int i;
601	con *c;
602
603	gettimeofday(&now, NULL);
ff2d7a98	604	c = TAILQ_FIRST(&tq);
3c0ef626	605
	606	if (c && (c->c_tv.tv_sec > now.tv_sec \|\|
	607	(c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
	608	seltime = c->c_tv;
	609	seltime.tv_sec -= now.tv_sec;
	610	seltime.tv_usec -= now.tv_usec;
	611	if (seltime.tv_usec < 0) {
	612	seltime.tv_usec += 1000000;
	613	seltime.tv_sec--;
	614	}
	615	} else
	616	seltime.tv_sec = seltime.tv_usec = 0;
	617
	618	r = xmalloc(read_wait_size);
	619	memcpy(r, read_wait, read_wait_size);
	620	e = xmalloc(read_wait_size);
	621	memcpy(e, read_wait, read_wait_size);
	622
	623	while (select(maxfd, r, NULL, e, &seltime) == -1 &&
	624	(errno == EAGAIN \|\| errno == EINTR))
	625	;
	626
	627	for (i = 0; i < maxfd; i++) {
	628	if (FD_ISSET(i, e)) {
	629	error("%s: exception!", fdcon[i].c_name);
	630	confree(i);
	631	} else if (FD_ISSET(i, r))
	632	conread(i);
	633	}
	634	xfree(r);
	635	xfree(e);
	636
ff2d7a98	637	c = TAILQ_FIRST(&tq);
3c0ef626	638	while (c && (c->c_tv.tv_sec < now.tv_sec \|\|
	639	(c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
	640	int s = c->c_fd;
	641
ff2d7a98	642	c = TAILQ_NEXT(c, c_link);
3c0ef626	643	conrecycle(s);
	644	}
	645	}
	646
	647	static void
	648	do_host(char *host)
	649	{
	650	char *name = strnnsep(&host, " \t\n");
	651	int j;
	652
e9a17296	653	if (name == NULL)
e9a17296	654	return;
3c0ef626	655	for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
	656	if (get_keytypes & j) {
	657	while (ncon >= MAXCON)
	658	conloop();
	659	conalloc(name, *host ? host : name, j);
	660	}
	661	}
	662	}
	663
e9a17296	664	void
e9a17296	665	fatal(const char *fmt,...)
3c0ef626	666	{
e9a17296	667	va_list args;
	668	va_start(args, fmt);
	669	do_log(SYSLOG_LEVEL_FATAL, fmt, args);
	670	va_end(args);
3c0ef626	671	if (nonfatal_fatal)
3c0ef626	672	longjmp(kexjmp, -1);
e9a17296	673	else
e9a17296	674	fatal_cleanup();
3c0ef626	675	}
	676
	677	static void
	678	usage(void)
	679	{
	680	fprintf(stderr, "Usage: %s [options] host ...\n",
	681	__progname);
	682	fprintf(stderr, "Options:\n");
	683	fprintf(stderr, " -f file Read hosts or addresses from file.\n");
	684	fprintf(stderr, " -p port Connect to the specified port.\n");
	685	fprintf(stderr, " -t keytype Specify the host key type.\n");
	686	fprintf(stderr, " -T timeout Set connection timeout.\n");
e9a17296	687	fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
	688	fprintf(stderr, " -4 Use IPv4 only.\n");
	689	fprintf(stderr, " -6 Use IPv6 only.\n");
3c0ef626	690	exit(1);
	691	}
	692
	693	int
	694	main(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]);
2b8f6339	704	init_pathnames();
3c0ef626	705	init_rng();
	706	seed_rng();
	707	TAILQ_INIT(&tq);
	708
	709	if (argc <= 1)
	710	usage();
	711
	712	while ((opt = getopt(argc, argv, "v46p:T:t:f:")) != -1) {
	713	switch (opt) {
	714	case 'p':
	715	ssh_port = a2port(optarg);
	716	if (ssh_port == 0) {
	717	fprintf(stderr, "Bad port '%s'\n", optarg);
	718	exit(1);
	719	}
	720	break;
	721	case 'T':
	722	timeout = atoi(optarg);
	723	if (timeout <= 0)
	724	usage();
	725	break;
	726	case 'v':
	727	if (!debug_flag) {
	728	debug_flag = 1;
	729	log_level = SYSLOG_LEVEL_DEBUG1;
	730	}
	731	else if (log_level < SYSLOG_LEVEL_DEBUG3)
	732	log_level++;
	733	else
	734	fatal("Too high debugging level.");
	735	break;
	736	case 'f':
	737	if (strcmp(optarg, "-") == 0)
	738	optarg = NULL;
	739	argv[fopt_count++] = optarg;
	740	break;
	741	case 't':
	742	get_keytypes = 0;
	743	tname = strtok(optarg, ",");
	744	while (tname) {
	745	int type = key_type_from_name(tname);
	746	switch (type) {
	747	case KEY_RSA1:
	748	get_keytypes \|= KT_RSA1;
	749	break;
	750	case KEY_DSA:
	751	get_keytypes \|= KT_DSA;
	752	break;
	753	case KEY_RSA:
	754	get_keytypes \|= KT_RSA;
	755	break;
	756	case KEY_UNSPEC:
e9a17296	757	fatal("unknown key type %s", tname);
3c0ef626	758	}
	759	tname = strtok(NULL, ",");
	760	}
	761	break;
	762	case '4':
	763	IPv4or6 = AF_INET;
	764	break;
	765	case '6':
	766	IPv4or6 = AF_INET6;
	767	break;
	768	case '?':
	769	default:
	770	usage();
	771	}
	772	}
	773	if (optind == argc && !fopt_count)
	774	usage();
	775
	776	log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
3c0ef626	777
	778	maxfd = fdlim_get(1);
	779	if (maxfd < 0)
	780	fatal("%s: fdlim_get: bad value", __progname);
	781	if (maxfd > MAXMAXFD)
	782	maxfd = MAXMAXFD;
	783	if (MAXCON <= 0)
	784	fatal("%s: not enough file descriptors", __progname);
	785	if (maxfd > fdlim_get(0))
	786	fdlim_set(maxfd);
	787	fdcon = xmalloc(maxfd * sizeof(con));
	788	memset(fdcon, 0, maxfd * sizeof(con));
	789
	790	read_wait_size = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
	791	read_wait = xmalloc(read_wait_size);
	792	memset(read_wait, 0, read_wait_size);
	793
	794	if (fopt_count) {
	795	Linebuf *lb;
	796	char *line;
	797	int j;
	798
	799	for (j = 0; j < fopt_count; j++) {
	800	lb = Linebuf_alloc(argv[j], error);
	801	if (!lb)
	802	continue;
	803	while ((line = Linebuf_getline(lb)) != NULL)
	804	do_host(line);
	805	Linebuf_free(lb);
	806	}
	807	}
	808
	809	while (optind < argc)
	810	do_host(argv[optind++]);
	811
	812	while (ncon > 0)
	813	conloop();
	814
	815	return (0);
	816	}