/*-

 * Copyright (c) 2004-2006 The NetBSD Foundation, Inc.

 * All rights reserved.

 *

 * This code is derived from software contributed to The NetBSD Foundation

 * by Luke Mewburn.

 * Timo Teräs cleaned up the code for use in Alpine Linux with musl libc.

 *

 * 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.

 *

 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.

 */

#include <sys/socket.h>

#include <sys/param.h>

#include <ctype.h>

#include <errno.h>

#include <limits.h>

#include <netdb.h>

#include <pwd.h>

#include <grp.h>

#include <stdio.h>

#include <stdarg.h>

#include <stdbool.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <paths.h>

#include <err.h>

#include <arpa/inet.h>

#include <arpa/nameser.h>

#include <net/if.h>

#include <net/ethernet.h>

#include <netinet/ether.h>

#include <netinet/in.h>

enum {

	RV_OK		= 0,

	RV_USAGE	= 1,

	RV_NOTFOUND	= 2,

	RV_NOENUM	= 3

};

static int usage(const char *);

static int parsenum(const char *word, unsigned long *result)

{

	unsigned long	num;

	char		*ep;

	if (!isdigit((unsigned char)word[0]))

		return 0;

	errno = 0;

	num = strtoul(word, &ep, 10);

	if (num == ULONG_MAX && errno == ERANGE)

		return 0;

	if (*ep != '\0')

		return 0;

	*result = num;

	return 1;

}

/*

 * printfmtstrings --

 *	vprintf(format, ...),

 *	then the aliases (beginning with prefix, separated by sep),

 *	then a newline

 */

__attribute__ ((format (printf, 4, 5)))

static void printfmtstrings(char *strings[], const char *prefix, const char *sep,

	const char *fmt, ...)

{

	va_list		ap;

	const char	*curpref;

	size_t		i;

	va_start(ap, fmt);

	(void)vprintf(fmt, ap);

	va_end(ap);

	curpref = prefix;

	for (i = 0; strings[i] != NULL; i++) {

		(void)printf("%s%s", curpref, strings[i]);

		curpref = sep;

	}

	(void)printf("\n");

}

static int ethers(int argc, char *argv[])

{

	char		hostname[MAXHOSTNAMELEN + 1], *hp;

	struct ether_addr ea, *eap;

	int		i, rv;

	if (argc == 2) {

		warnx("Enumeration not supported on ethers");

		return RV_NOENUM;

	}

	rv = RV_OK;

	for (i = 2; i < argc; i++) {

		if ((eap = ether_aton(argv[i])) == NULL) {

			eap = &ea;

			hp = argv[i];

			if (ether_hostton(hp, eap) != 0) {

				rv = RV_NOTFOUND;

				break;

			}

		} else {

			hp = hostname;

			if (ether_ntohost(hp, eap) != 0) {

				rv = RV_NOTFOUND;

				break;

			}

		}

		(void)printf("%-17s  %s\n", ether_ntoa(eap), hp);

	}

	return rv;

}

static void groupprint(const struct group *gr)

{

	printfmtstrings(gr->gr_mem, ":", ",", "%s:%s:%u",

			gr->gr_name, gr->gr_passwd, gr->gr_gid);

}

static int group(int argc, char *argv[])

{

	struct group	*gr;

	unsigned long	id;

	int		i, rv;

	rv = RV_OK;

	if (argc == 2) {

		while ((gr = getgrent()) != NULL)

			groupprint(gr);

	} else {

		for (i = 2; i < argc; i++) {

			if (parsenum(argv[i], &id))

				gr = getgrgid((gid_t)id);

			else

				gr = getgrnam(argv[i]);

			if (gr == NULL) {

				rv = RV_NOTFOUND;

				break;

			}

			groupprint(gr);

		}

	}

	endgrent();

	return rv;

}

static void hostsprint(const struct hostent *he)

{

	char	buf[INET6_ADDRSTRLEN];

	if (inet_ntop(he->h_addrtype, he->h_addr, buf, sizeof(buf)) == NULL)

		(void)strlcpy(buf, "# unknown", sizeof(buf));

	printfmtstrings(he->h_aliases, "  ", " ", "%-16s  %s", buf, he->h_name);

}

static int hosts(int argc, char *argv[])

{

	struct hostent	*he;

	char		addr[IN6ADDRSZ];

	int		i, rv;

	sethostent(1);

	rv = RV_OK;

	if (argc == 2) {

		while ((he = gethostent()) != NULL)

			hostsprint(he);

	} else {

		for (i = 2; i < argc; i++) {

			if (inet_pton(AF_INET6, argv[i], (void *)addr) > 0)

				he = gethostbyaddr(addr, IN6ADDRSZ, AF_INET6);

			else if (inet_pton(AF_INET, argv[i], (void *)addr) > 0)

				he = gethostbyaddr(addr, INADDRSZ, AF_INET);

			else

				he = gethostbyname(argv[i]);

			if (he == NULL) {

				rv = RV_NOTFOUND;

				break;

			}

			hostsprint(he);

		}

	}

	endhostent();

	return rv;

}

static void networksprint(const struct netent *ne)

{

	char		buf[INET6_ADDRSTRLEN];

	struct	in_addr	ianet;

	ianet = inet_makeaddr(ne->n_net, 0);

	if (inet_ntop(ne->n_addrtype, &ianet, buf, sizeof(buf)) == NULL)

		(void)strlcpy(buf, "# unknown", sizeof(buf));

	printfmtstrings(ne->n_aliases, "  ", " ", "%-16s  %s", ne->n_name, buf);

}

static int networks(int argc, char *argv[])

{

	struct netent	*ne;

	in_addr_t	net;

	int		i, rv;

	setnetent(1);

	rv = RV_OK;

	if (argc == 2) {

		while ((ne = getnetent()) != NULL)

			networksprint(ne);

	} else {

		for (i = 2; i < argc; i++) {

			net = inet_network(argv[i]);

			if (net != INADDR_NONE)

				ne = getnetbyaddr(net, AF_INET);

			else

				ne = getnetbyname(argv[i]);

			if (ne != NULL) {

				rv = RV_NOTFOUND;

				break;

			}

			networksprint(ne);

		}

	}

	endnetent();

	return rv;

}

static void passwdprint(struct passwd *pw)

{

	(void)printf("%s:%s:%u:%u:%s:%s:%s\n",

		pw->pw_name, pw->pw_passwd, pw->pw_uid,

		pw->pw_gid, pw->pw_gecos, pw->pw_dir, pw->pw_shell);

}

static int passwd(int argc, char *argv[])

{

	struct passwd	*pw;

	unsigned long	id;

	int		i, rv;

	rv = RV_OK;

	if (argc == 2) {

		while ((pw = getpwent()) != NULL)

			passwdprint(pw);

	} else {

		for (i = 2; i < argc; i++) {

			if (parsenum(argv[i], &id))

				pw = getpwuid((uid_t)id);

			else

				pw = getpwnam(argv[i]);

			if (pw == NULL) {

				rv = RV_NOTFOUND;

				break;

			}

			passwdprint(pw);

		}

	}

	endpwent();

	return rv;

}

static void protocolsprint(struct protoent *pe)

{

	printfmtstrings(pe->p_aliases, "  ", " ",

			"%-16s  %5d", pe->p_name, pe->p_proto);

}

static int protocols(int argc, char *argv[])

{

	struct protoent	*pe;

	unsigned long	id;

	int		i, rv;

	setprotoent(1);

	rv = RV_OK;

	if (argc == 2) {

		while ((pe = getprotoent()) != NULL)

			protocolsprint(pe);

	} else {

		for (i = 2; i < argc; i++) {

			if (parsenum(argv[i], &id))

				pe = getprotobynumber((int)id);

			else

				pe = getprotobyname(argv[i]);

			if (pe == NULL) {

				rv = RV_NOTFOUND;

				break;

			}

			protocolsprint(pe);

		}

	}

	endprotoent();

	return rv;

}

static void servicesprint(struct servent *se)

{

	printfmtstrings(se->s_aliases, "  ", " ",

			"%-16s  %5d/%s",

			se->s_name, ntohs(se->s_port), se->s_proto);

}

static int services(int argc, char *argv[])

{

	struct servent	*se;

	unsigned long	id;

	char		*proto;

	int		i, rv;

	setservent(1);

	rv = RV_OK;

	if (argc == 2) {

		while ((se = getservent()) != NULL)

			servicesprint(se);

	} else {

		for (i = 2; i < argc; i++) {

			proto = strchr(argv[i], '/');

			if (proto != NULL)

				*proto++ = '\0';

			if (parsenum(argv[i], &id))

				se = getservbyport(htons(id), proto);

			else

				se = getservbyname(argv[i], proto);

			if (se == NULL) {

				rv = RV_NOTFOUND;

				break;

			}

			servicesprint(se);

		}

	}

	endservent();

	return rv;

}

static int shells(int argc, char *argv[])

{

	const char	*sh;

	int		i, rv;

	setusershell();

	rv = RV_OK;

	if (argc == 2) {

		while ((sh = getusershell()) != NULL)

			(void)printf("%s\n", sh);

	} else {

		for (i = 2; i < argc; i++) {

			setusershell();

			while ((sh = getusershell()) != NULL) {

				if (strcmp(sh, argv[i]) == 0) {

					(void)printf("%s\n", sh);

					break;

				}

			}

			if (sh == NULL) {

				rv = RV_NOTFOUND;

				break;

			}

		}

	}

	endusershell();

	return rv;

}

static struct getentdb {

	const char	*name;

	int		(*callback)(int, char *[]);

} databases[] = {

	{	"ethers",	ethers,		},

	{	"group",	group,		},

	{	"hosts",	hosts,		},

	{	"networks",	networks,	},

	{	"passwd",	passwd,		},

	{	"protocols",	protocols,	},

	{	"services",	services,	},

	{	"shells",	shells,		},

	{	NULL,		NULL,		},

};

static int usage(const char *arg0)

{

	struct getentdb	*curdb;

	size_t i;

	(void)fprintf(stderr, "Usage: %s database [key ...]\n", arg0);

	(void)fprintf(stderr, "\tdatabase may be one of:");

	for (i = 0, curdb = databases; curdb->name != NULL; curdb++, i++) {

		if (i % 7 == 0)

			(void)fputs("\n\t\t", stderr);

		(void)fprintf(stderr, "%s%s", i % 7 == 0 ? "" : " ",

		    curdb->name);

	}

	(void)fprintf(stderr, "\n");

	exit(RV_USAGE);

	/* NOTREACHED */

}

int

main(int argc, char *argv[])

{

	struct getentdb	*curdb;

	if (argc < 2)

		usage(argv[0]);

	for (curdb = databases; curdb->name != NULL; curdb++)

		if (strcmp(curdb->name, argv[1]) == 0)

			return (*curdb->callback)(argc, argv);

	warn("Unknown database `%s'", argv[1]);

	usage(argv[0]);

	/* NOTREACHED */

}