/*
 * Copyright (c) 1983 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1983 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
/*static char sccsid[] = "from: @(#)gettable.c	5.6 (Berkeley) 3/2/91";*/
static char rcsid[] = "$Id: gettable.c,v 1.1 1995/10/18 08:47:34 deraadt Exp $";
#endif /* not lint */

#include <sys/types.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <stdio.h>
#include <string.h>
#include <netdb.h>

#define	OUTFILE		"hosts.txt"	/* default output file */
#define	VERFILE		"hosts.ver"	/* default version file */
#define	QUERY		"ALL\r\n"	/* query to hostname server */
#define	VERSION		"VERSION\r\n"	/* get version number */

#define	equaln(s1, s2, n)	(!strncmp(s1, s2, n))

struct	sockaddr_in s_in;
char	buf[BUFSIZ];
char	*outfile = OUTFILE;

main(argc, argv)
	int argc;
	char *argv[];
{
	int s;
	register len;
	register FILE *sfi, *sfo, *hf;
	char *host;
	register struct hostent *hp;
	struct servent *sp;
	int version = 0;
	int beginseen = 0;
	int endseen = 0;

	argv++, argc--;
	if (*argv && **argv == '-') {
		if (argv[0][1] != 'v')
			fprintf(stderr, "unknown option %s ignored\n", *argv);
		else
			version++, outfile = VERFILE;
		argv++, argc--;
	}
	if (argc < 1 || argc > 2) {
		fprintf(stderr, "usage: gettable [-v] host [ file ]\n");
		exit(1);
	}
	sp = getservbyname("hostnames", "tcp");
	if (sp == NULL) {
		fprintf(stderr, "gettable: hostnames/tcp: unknown service\n");
		exit(3);
	}
	host = *argv;
	argv++, argc--;
	hp = gethostbyname(host);
	if (hp == NULL) {
		fprintf(stderr, "gettable: %s: ", host);
		herror((char *)NULL);
		exit(2);
	}
	host = hp->h_name;
	if (argc > 0)
		outfile = *argv;
	s_in.sin_family = hp->h_addrtype;
	s = socket(hp->h_addrtype, SOCK_STREAM, 0);
	if (s < 0) {
		perror("gettable: socket");
		exit(4);
	}
	if (bind(s, (struct sockaddr *)&s_in, sizeof (s_in)) < 0) {
		perror("gettable: bind");
		exit(5);
	}
	bcopy(hp->h_addr, &s_in.sin_addr, hp->h_length);
	s_in.sin_port = sp->s_port;
	if (connect(s, (struct sockaddr *)&s_in, sizeof (s_in)) < 0) {
		perror("gettable: connect");
		exit(6);
	}
	fprintf(stderr, "Connection to %s opened.\n", host);
	sfi = fdopen(s, "r");
	sfo = fdopen(s, "w");
	if (sfi == NULL || sfo == NULL) {
		perror("gettable: fdopen");
		close(s);
		exit(1);
	}
	hf = fopen(outfile, "w");
	if (hf == NULL) {
		fprintf(stderr, "gettable: "); perror(outfile);
		close(s);
		exit(1);
	}
	fprintf(sfo, version ? VERSION : QUERY);
	fflush(sfo);
	while (fgets(buf, sizeof(buf), sfi) != NULL) {
		len = strlen(buf);
		buf[len-2] = '\0';
		if (!version && equaln(buf, "BEGIN", 5)) {
			if (beginseen || endseen) {
				fprintf(stderr,
				    "gettable: BEGIN sequence error\n");
				exit(90);
			}
			beginseen++;
			continue;
		}
		if (!version && equaln(buf, "END", 3)) {
			if (!beginseen || endseen) {
				fprintf(stderr,
				    "gettable: END sequence error\n");
				exit(91);
			}
			endseen++;
			continue;
		}
		if (equaln(buf, "ERR", 3)) {
			fprintf(stderr,
			    "gettable: hostname service error: %s", buf);
			exit(92);
		}
		fprintf(hf, "%s\n", buf);
	}
	fclose(hf);
	if (!version) {
		if (!beginseen) {
			fprintf(stderr, "gettable: no BEGIN seen\n");
			exit(93);
		}
		if (!endseen) {
			fprintf(stderr, "gettable: no END seen\n");
			exit(94);
		}
		fprintf(stderr, "Host table received.\n");
	} else
		fprintf(stderr, "Version number received.\n");
	close(s);
	fprintf(stderr, "Connection to %s closed\n", host);
	exit(0);
}