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h_hostent.c revision 1.1
      1 /*	$NetBSD: h_hostent.c,v 1.1 2013/08/16 15:29:45 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2013 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Christos Zoulas.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 #include <sys/cdefs.h>
     32 __RCSID("$NetBSD: h_hostent.c,v 1.1 2013/08/16 15:29:45 christos Exp $");
     33 
     34 #include <stdio.h>
     35 #include <string.h>
     36 #include <nsswitch.h>
     37 #include <netdb.h>
     38 #include <stdint.h>
     39 #include <stdlib.h>
     40 #include <unistd.h>
     41 #include <err.h>
     42 
     43 #include <netinet/in.h>
     44 #include <sys/types.h>
     45 #include <arpa/nameser.h>
     46 #include <arpa/inet.h>
     47 
     48 #include "hostent.h"
     49 
     50 static void
     51 phostent(const struct hostent *h)
     52 {
     53 	size_t i;
     54 	char buf[1024];
     55 	const int af = h->h_length == NS_INADDRSZ ? AF_INET : AF_INET6;
     56 
     57 	printf("name=%s, length=%d, addrtype=%d, aliases=[",
     58 	    h->h_name, h->h_length, h->h_addrtype);
     59 
     60 	for (i = 0; h->h_aliases[i]; i++)
     61 		printf("%s%s", i == 0 ? "" : " ", h->h_aliases[i]);
     62 
     63 	printf("] addr_list=[");
     64 
     65 	for (i = 0; h->h_addr_list[i]; i++)
     66 		printf("%s%s", i == 0 ? "" : " ", inet_ntop(af,
     67 		    h->h_addr_list[i], buf, (socklen_t)sizeof(buf)));
     68 
     69 	printf("]\n");
     70 }
     71 
     72 static void
     73 usage(void)
     74 {
     75 	(void)fprintf(stderr, "Usage: %s [-f <hostsfile>] "
     76 	    "[-t <any|dns|nis|files>] "
     77 	    "[-46a] <name|address>\n", getprogname());
     78 	exit(EXIT_FAILURE);
     79 }
     80 
     81 static void
     82 getby(int (*f)(void *, void *, va_list), struct getnamaddr *info, ...)
     83 {
     84 	va_list ap;
     85 	int e;
     86 
     87 	va_start(ap, info);
     88 	e = (*f)(info, NULL, ap);
     89 	va_end(ap);
     90 	switch (e) {
     91 	case NS_SUCCESS:
     92 		phostent(info->hp);
     93 		break;
     94 	default:
     95 		printf("error %d\n", e);
     96 		break;
     97 	}
     98 }
     99 
    100 static void
    101 geta(struct hostent *hp) {
    102 	if (hp == NULL)
    103 		printf("error %d\n", h_errno);
    104 	else
    105 		phostent(hp);
    106 }
    107 
    108 int
    109 main(int argc, char *argv[])
    110 {
    111 	int (*f)(void *, void *, va_list) = NULL;
    112 	const char *type = "any";
    113 	int c, af, e, byaddr, len;
    114 	struct hostent hent;
    115 	struct getnamaddr info;
    116 	char buf[4096];
    117 
    118 	af = AF_INET;
    119 	byaddr = 0;
    120 	len = 0;
    121 	info.hp = &hent;
    122 	info.buf = buf;
    123 	info.buflen = sizeof(buf);
    124 	info.he = &e;
    125 
    126 	while ((c = getopt(argc, argv, "46af:t:")) != -1) {
    127 		switch (c) {
    128 		case '4':
    129 			af = AF_INET;
    130 			break;
    131 		case '6':
    132 			af = AF_INET6;
    133 			break;
    134 		case 'a':
    135 			byaddr++;
    136 			break;
    137 		case 't':
    138 			type = optarg;
    139 			break;
    140 		case 'f':
    141 			_hf_sethostsfile(optarg);
    142 			break;
    143 		default:
    144 			usage();
    145 		}
    146 	}
    147 
    148 	argc -= optind;
    149 	argv += optind;
    150 
    151 	if (argc != 1)
    152 		usage();
    153 
    154 	switch (*type) {
    155 	case 'a':
    156 		break;
    157 	case 'd':
    158 		f = byaddr ? _dns_gethtbyaddr : _dns_gethtbyname;
    159 		break;
    160 #ifdef YP
    161 	case 'n':
    162 		f = byaddr ? _yp_gethtbyaddr : _yp_gethtbyname;
    163 		break;
    164 #endif
    165 	case 'f':
    166 		f = byaddr ? _hf_gethtbyaddr : _hf_gethtbyname;
    167 		break;
    168 	default:
    169 		errx(EXIT_FAILURE, "Unknown db type `%s'", type);
    170 	}
    171 
    172 	if (byaddr) {
    173 		struct in6_addr addr;
    174 		af = strchr(*argv, ':') ? AF_INET6 : AF_INET;
    175 		len = af == AF_INET ? NS_INADDRSZ : NS_IN6ADDRSZ;
    176 		if (inet_pton(af, *argv, &addr) == -1)
    177 			err(EXIT_FAILURE, "Can't parse `%s'", *argv);
    178 		if (*type == 'a')
    179 			geta(gethostbyaddr((const char *)&addr, len, af));
    180 		else
    181 			getby(f, &info, &addr, len, af);
    182 	} else {
    183 		if (*type == 'a')
    184 			geta(gethostbyname2(*argv, af));
    185 		else
    186 			getby(f, &info, *argv, len, af);
    187 	}
    188 
    189 	return 0;
    190 }
    191