1 files changed, 832 insertions, 0 deletions

diff --git a/usr/src/cmd/ssh/ssh-keyscan/ssh-keyscan.c b/usr/src/cmd/ssh/ssh-keyscan/ssh-keyscan.c
new file mode 100644
index 0000000000..01fd90f825
--- /dev/null
+++ b/usr/src/cmd/ssh/ssh-keyscan/ssh-keyscan.c
@@ -0,0 +1,832 @@
+/*
+ * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+/*
+ * 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 1.40 2002/07/06 17:47:58 stevesk Exp $");
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include "sys-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"
+
+/* 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",
+			    filename ? filename : "(stdin)");
+		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;
+	void *p;
+
+	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 */
+		lb->size *= 2;
+		if ((p = realloc(lb->buf, lb->size)) == NULL) {
+			lb->size /= 2;
+			if (lb->errfun)
+				(*lb->errfun)("linebuf (%s): realloc failed\n",
+				    lb->filename);
+			return (NULL);
+		}
+		lb->buf = p;
+	}
+}
+
+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);
+	/* NOTREACHED */
+	return (0);
+}
+
+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(c->c_name, myproposal, NULL);
+	c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
+	c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
+	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)
+{
+	char *namebase, *name, *namelist;
+	int s;
+
+	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)
+{
+	con *c = &fdcon[s];
+	int ret;
+
+	ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
+	confree(s);
+	return (ret);
+}
+
+static void
+congreet(int s)
+{
+	int remote_major, remote_minor, n = 0;
+	char buf[256], *cp;
+	char remote_version[sizeof buf];
+	size_t bufsiz;
+	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)
+{
+	con *c = &fdcon[s];
+	int n;
+
+	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)
+{
+	struct timeval seltime, now;
+	fd_set *r, *e;
+	con *c;
+	int i;
+
+	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,
+		gettext("Usage: %s [-v46] [-p port] [-T timeout] [-f file]\n"
+			"\t\t   [host | addrlist namelist] [...]\n"),
+	    __progname);
+	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]);
+
+	(void) g11n_setlocale(LC_ALL, "");
+
+	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, gettext("Bad port '%s'\n"),
+					optarg);
+				exit(1);
+			}
+			break;
+		case 'T':
+			timeout = convtime(optarg);
+			if (timeout == -1 || timeout == 0) {
+				fprintf(stderr, gettext("Bad timeout '%s'\n"),
+					optarg);
+				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);
+}