test harness for gethostbyname()/gethostbyaddr() and their internal bits.
XXX[1]: How can we avoid using hard-coded hosts for DNS
XXX[2]: How do we test NIS?


(christos)

/*	$NetBSD: h_hostent.c,v 1.1 2013/08/16 15:29:45 christos Exp $	*/

/*-
 * Copyright (c) 2013 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Christos Zoulas.
 *
 * 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/cdefs.h>
__RCSID("$NetBSD: h_hostent.c,v 1.1 2013/08/16 15:29:45 christos Exp $");

#include <stdio.h>
#include <string.h>
#include <nsswitch.h>
#include <netdb.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <err.h>

#include <netinet/in.h>
#include <sys/types.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>

#include "hostent.h"

static void
phostent(const struct hostent *h)
{
	size_t i;
	char buf[1024];
	const int af = h->h_length == NS_INADDRSZ ? AF_INET : AF_INET6;

	printf("name=%s, length=%d, addrtype=%d, aliases=[",
	    h->h_name, h->h_length, h->h_addrtype);

	for (i = 0; h->h_aliases[i]; i++)
		printf("%s%s", i == 0 ? "" : " ", h->h_aliases[i]);

	printf("] addr_list=[");

	for (i = 0; h->h_addr_list[i]; i++)
		printf("%s%s", i == 0 ? "" : " ", inet_ntop(af,
		    h->h_addr_list[i], buf, (socklen_t)sizeof(buf)));

	printf("]\n");
}

static void
usage(void)
{
	(void)fprintf(stderr, "Usage: %s [-f <hostsfile>] "
	    "[-t <any|dns|nis|files>] "
	    "[-46a] <name|address>\n", getprogname());
	exit(EXIT_FAILURE);
}

static void
getby(int (*f)(void *, void *, va_list), struct getnamaddr *info, ...)
{
	va_list ap;
	int e;

	va_start(ap, info);
	e = (*f)(info, NULL, ap);
	va_end(ap);
	switch (e) {
	case NS_SUCCESS:
		phostent(info->hp);
		break;
	default:
		printf("error %d\n", e);
		break;
	}
}

static void
geta(struct hostent *hp) {
	if (hp == NULL)
		printf("error %d\n", h_errno);
	else
		phostent(hp);
}

int
main(int argc, char *argv[])
{
	int (*f)(void *, void *, va_list) = NULL;
	const char *type = "any";
	int c, af, e, byaddr, len;
	struct hostent hent;
	struct getnamaddr info;
	char buf[4096];
	
	af = AF_INET;
	byaddr = 0;
	len = 0;
	info.hp = &hent;
	info.buf = buf;
	info.buflen = sizeof(buf);
	info.he = &e;

	while ((c = getopt(argc, argv, "46af:t:")) != -1) {
		switch (c) {
		case '4':
			af = AF_INET;
			break;
		case '6':
			af = AF_INET6;
			break;
		case 'a':
			byaddr++;
			break;
		case 't':
			type = optarg;
			break;
		case 'f':
			_hf_sethostsfile(optarg);
			break;
		default:
			usage();
		}
	}

	argc -= optind;
	argv += optind;

	if (argc != 1)
		usage();

	switch (*type) {
	case 'a':
		break;
	case 'd':
		f = byaddr ? _dns_gethtbyaddr : _dns_gethtbyname;
		break;
#ifdef YP
	case 'n':
		f = byaddr ? _yp_gethtbyaddr : _yp_gethtbyname;
		break;
#endif
	case 'f':
		f = byaddr ? _hf_gethtbyaddr : _hf_gethtbyname;
		break;
	default:
		errx(EXIT_FAILURE, "Unknown db type `%s'", type);
	}

	if (byaddr) {
		struct in6_addr addr;
		af = strchr(*argv, ':') ? AF_INET6 : AF_INET;
		len = af == AF_INET ? NS_INADDRSZ : NS_IN6ADDRSZ;
		if (inet_pton(af, *argv, &addr) == -1)
			err(EXIT_FAILURE, "Can't parse `%s'", *argv);
		if (*type == 'a')
			geta(gethostbyaddr((const char *)&addr, len, af));
		else
			getby(f, &info, &addr, len, af);
	} else {
		if (*type == 'a')
			geta(gethostbyname2(*argv, af));
		else
			getby(f, &info, *argv, len, af);
	}
		
	return 0;
}

#	$NetBSD: hosts,v 1.1 2013/08/16 15:29:45 christos Exp $
#
# Host Database
# This file should contain the addresses and aliases
# for local hosts that share this file.
# It is used only for "ifconfig" and other operations
# before the nameserver is started.
#
#
::1			localhost localhost. localhost.localdomain.
127.0.0.1		localhost localhost. localhost.localdomain.

# $NetBSD: t_hostent.sh,v 1.1 2013/08/16 15:29:45 christos Exp $
#
# Copyright (c) 2008 The NetBSD Foundation, Inc.
# 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.
#
# 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.
#

n6="sixthavenue.astron.com"
a6="2620:106:3000:100:2e0:81ff:fe2f:e5d6"
ans6="name=$n6, length=16, addrtype=24, aliases=[] addr_list=[$a6]\n"

n4="sixthavenue.astron.com"
a4="208.77.212.99"
ans4="name=$n4, length=4, addrtype=2, aliases=[] addr_list=[$a4]\n"

l6="localhost"
al6="::1"
loc6="name=$l6, length=16, addrtype=24, aliases=[localhost. localhost.localdomain.] addr_list=[$al6]\n"

l4="localhost"
al4="127.0.0.1"
loc4="name=$l4, length=4, addrtype=2, aliases=[localhost. localhost.localdomain.] addr_list=[$al4]\n"

atf_test_case gethostbyname4
gethostbyname4_head()
{
	atf_set "descr" "Checks gethostbyname2(3) for AF_INET (auto, as determined by nsswitch.conf(5)"
}
gethostbyname4_body()
{
	atf_check -o inline:"$ans4" -x "$(atf_get_srcdir)/h_hostent -t auto -4 $n4"
}

atf_test_case gethostbyname6
gethostbyname6_head()
{
	atf_set "descr" "Checks gethostbyname2(3) for AF_INET6 (auto, as determined by nsswitch.conf(5)"
}
gethostbyname6_body()
{
	atf_check -o inline:"$ans6" -x "$(atf_get_srcdir)/h_hostent -t auto -6 $n6"
}

atf_test_case gethostbyaddr4
gethostbyaddr4_head()
{
	atf_set "descr" "Checks gethostbyaddr(3) for AF_INET (auto, as determined by nsswitch.conf(5)"
}
gethostbyaddr4_body()
{
	atf_check -o inline:"$ans4" -x "$(atf_get_srcdir)/h_hostent -t auto -a $a4"
}

atf_test_case gethostbyaddr6
gethostbyaddr6_head()
{
	atf_set "descr" "Checks gethostbyaddr(3) for AF_INET6 (auto, as determined by nsswitch.conf(5)"
}
gethostbyaddr6_body()
{
	atf_check -o inline:"$ans6" -x "$(atf_get_srcdir)/h_hostent -t auto -a $a6"
}

atf_test_case hostsbynamelookup4
hostsbynamelookup4_head()
{
	atf_set "descr" "Checks /etc/hosts name lookup for AF_INET"
}
hostsbynamelookup4_body()
{
	local dir=$(atf_get_srcdir)
	atf_check -o inline:"$loc4" -x "$dir/h_hostent -f $dir/hosts -t file -4 $l4"
}

atf_test_case hostsbynamelookup6
hostsbynamelookup6_head()
{
	atf_set "descr" "Checks /etc/hosts name lookup for AF_INET6"
}
hostsbynamelookup6_body()
{
	local dir=$(atf_get_srcdir)
	atf_check -o inline:"$loc6" -x "$dir/h_hostent -f $dir/hosts -t file -6 $l6"
}

atf_test_case hostsbyaddrlookup4
hostsbyaddrlookup4_head()
{
	atf_set "descr" "Checks /etc/hosts address lookup for AF_INET"
}
hostsbyaddrlookup4_body()
{
	local dir=$(atf_get_srcdir)
	atf_check -o inline:"$loc4" -x "$dir/h_hostent -f $dir/hosts -t file -4 -a $al4"
}

atf_test_case hostsbyaddrlookup6
hostsbyaddrlookup6_head()
{
	atf_set "descr" "Checks /etc/hosts address lookup for AF_INET6"
}
hostsbyaddrlookup6_body()
{
	local dir=$(atf_get_srcdir)
	atf_check -o inline:"$loc6" -x "$dir/h_hostent -f $dir/hosts -t file -6 -a $al6"
}

atf_test_case dnsbynamelookup4
dnsbynamelookup4_head()
{
	atf_set "descr" "Checks DNS name lookup for AF_INET"
}
dnsbynamelookup4_body()
{
	local dir=$(atf_get_srcdir)
	atf_check -o inline:"$ans4" -x "$dir/h_hostent -t dns -4 $n4"
}

atf_test_case dnsbynamelookup6
dnsbynamelookup6_head()
{
	atf_set "descr" "Checks DNS name lookup for AF_INET6"
}
dnsbynamelookup6_body()
{
	local dir=$(atf_get_srcdir)
	atf_check -o inline:"$ans6" -x "$dir/h_hostent -t dns -6 $n6"
}

atf_test_case dnsbyaddrlookup4
dnsbyaddrlookup4_head()
{
	atf_set "descr" "Checks DNS address lookup for AF_INET"
}
dnsbyaddrlookup4_body()
{
	local dir=$(atf_get_srcdir)
	atf_check -o inline:"$ans4" -x "$dir/h_hostent -t dns -4 -a $a4"
}

atf_test_case dnsbyaddrlookup6
dnsbyaddrlookup6_head()
{
	atf_set "descr" "Checks dns address lookup for AF_INET6"
}
dnsbyaddrlookup6_body()
{
	local dir=$(atf_get_srcdir)
	atf_check -o inline:"$ans6" -x "$dir/h_hostent -t dns -6 -a $a6"
}

atf_init_test_cases()
{
	atf_add_test_case gethostbyname4
	atf_add_test_case gethostbyname6
	atf_add_test_case gethostbyaddr4
	atf_add_test_case gethostbyaddr6

	atf_add_test_case hostsbynamelookup4
	atf_add_test_case hostsbynamelookup6
	atf_add_test_case hostsbyaddrlookup4
	atf_add_test_case hostsbyaddrlookup6

	atf_add_test_case dnsbynamelookup4
	atf_add_test_case dnsbynamelookup6
	atf_add_test_case dnsbyaddrlookup4
	atf_add_test_case dnsbyaddrlookup6
}