1 /*	$NetBSD: getaddresses.c,v 1.6 2015/07/08 17:28:58 christos Exp $	*/
2 
3 /*
4  * Copyright (C) 2004, 2005, 2007, 2014, 2015  Internet Systems Consortium, Inc. ("ISC")
5  * Copyright (C) 2001, 2002  Internet Software Consortium.
6  *
7  * Permission to use, copy, modify, and/or distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
17  * PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 /* Id: getaddresses.c,v 1.22 2007/06/19 23:47:16 tbox Exp  */
21 
22 /*! \file */
23 
24 #include <config.h>
25 #include <string.h>
26 
27 #include <isc/net.h>
28 #include <isc/netaddr.h>
29 #include <isc/netdb.h>
30 #include <isc/netscope.h>
31 #include <isc/result.h>
32 #include <isc/sockaddr.h>
33 #include <isc/util.h>
34 
35 #include <bind9/getaddresses.h>
36 
37 #ifdef HAVE_ADDRINFO
38 #ifdef HAVE_GETADDRINFO
39 #ifdef HAVE_GAISTRERROR
40 #define USE_GETADDRINFO
41 #endif
42 #endif
43 #endif
44 
45 #ifndef USE_GETADDRINFO
46 #ifndef ISC_PLATFORM_NONSTDHERRNO
47 extern int h_errno;
48 #endif
49 #endif
50 
51 isc_result_t
52 bind9_getaddresses(const char *hostname, in_port_t port,
53 		   isc_sockaddr_t *addrs, int addrsize, int *addrcount)
54 {
55 	struct in_addr in4;
56 	struct in6_addr in6;
57 	isc_boolean_t have_ipv4, have_ipv6;
58 	int i;
59 
60 #ifdef USE_GETADDRINFO
61 	struct addrinfo *ai = NULL, *tmpai, hints;
62 	int result;
63 #else
64 	struct hostent *he;
65 #endif
66 
67 	REQUIRE(hostname != NULL);
68 	REQUIRE(addrs != NULL);
69 	REQUIRE(addrcount != NULL);
70 	REQUIRE(addrsize > 0);
71 
72 	have_ipv4 = ISC_TF((isc_net_probeipv4() == ISC_R_SUCCESS));
73 	have_ipv6 = ISC_TF((isc_net_probeipv6() == ISC_R_SUCCESS));
74 
75 	/*
76 	 * Try IPv4, then IPv6.  In order to handle the extended format
77 	 * for IPv6 scoped addresses (address%scope_ID), we'll use a local
78 	 * working buffer of 128 bytes.  The length is an ad-hoc value, but
79 	 * should be enough for this purpose; the buffer can contain a string
80 	 * of at least 80 bytes for scope_ID in addition to any IPv6 numeric
81 	 * addresses (up to 46 bytes), the delimiter character and the
82 	 * terminating NULL character.
83 	 */
84 	if (inet_pton(AF_INET, hostname, &in4) == 1) {
85 		if (have_ipv4)
86 			isc_sockaddr_fromin(&addrs[0], &in4, port);
87 		else
88 			isc_sockaddr_v6fromin(&addrs[0], &in4, port);
89 		*addrcount = 1;
90 		return (ISC_R_SUCCESS);
91 	} else if (strlen(hostname) <= 127U) {
92 		char tmpbuf[128], *d;
93 		isc_uint32_t zone = 0;
94 
95 		strcpy(tmpbuf, hostname);
96 		d = strchr(tmpbuf, '%');
97 		if (d != NULL)
98 			*d = '\0';
99 
100 		if (inet_pton(AF_INET6, tmpbuf, &in6) == 1) {
101 			isc_netaddr_t na;
102 
103 			if (!have_ipv6)
104 				return (ISC_R_FAMILYNOSUPPORT);
105 
106 			if (d != NULL) {
107 #ifdef ISC_PLATFORM_HAVESCOPEID
108 				isc_result_t iresult;
109 
110 				iresult = isc_netscope_pton(AF_INET6, d + 1,
111 							    &in6, &zone);
112 
113 				if (iresult != ISC_R_SUCCESS)
114 					return (iresult);
115 #else
116 				/*
117 				 * The extended format is specified while the
118 				 * system does not provide the ability to use
119 				 * it.	Throw an explicit error instead of
120 				 * ignoring the specified value.
121 				 */
122 				return (ISC_R_BADADDRESSFORM);
123 #endif
124 			}
125 
126 			isc_netaddr_fromin6(&na, &in6);
127 			isc_netaddr_setzone(&na, zone);
128 			isc_sockaddr_fromnetaddr(&addrs[0],
129 						 (const isc_netaddr_t *)&na,
130 						 port);
131 
132 			*addrcount = 1;
133 			return (ISC_R_SUCCESS);
134 		}
135 	}
136 #ifdef USE_GETADDRINFO
137 	memset(&hints, 0, sizeof(hints));
138 	if (!have_ipv6)
139 		hints.ai_family = PF_INET;
140 	else if (!have_ipv4)
141 		hints.ai_family = PF_INET6;
142 	else {
143 		hints.ai_family = PF_UNSPEC;
144 #ifdef AI_ADDRCONFIG
145 		hints.ai_flags = AI_ADDRCONFIG;
146 #endif
147 	}
148 	hints.ai_socktype = SOCK_STREAM;
149 #ifdef AI_ADDRCONFIG
150  again:
151 #endif
152 	result = getaddrinfo(hostname, NULL, &hints, &ai);
153 	switch (result) {
154 	case 0:
155 		break;
156 	case EAI_NONAME:
157 #if defined(EAI_NODATA) && (EAI_NODATA != EAI_NONAME)
158 	case EAI_NODATA:
159 #endif
160 		return (ISC_R_NOTFOUND);
161 #ifdef AI_ADDRCONFIG
162 	case EAI_BADFLAGS:
163 		if ((hints.ai_flags & AI_ADDRCONFIG) != 0) {
164 			hints.ai_flags &= ~AI_ADDRCONFIG;
165 			goto again;
166 		}
167 #endif
168 	default:
169 		return (ISC_R_FAILURE);
170 	}
171 	for (tmpai = ai, i = 0;
172 	     tmpai != NULL && i < addrsize;
173 	     tmpai = tmpai->ai_next)
174 	{
175 		if (tmpai->ai_family != AF_INET &&
176 		    tmpai->ai_family != AF_INET6)
177 			continue;
178 		if (tmpai->ai_family == AF_INET) {
179 			struct sockaddr_in *sin;
180 			sin = (struct sockaddr_in *)tmpai->ai_addr;
181 			isc_sockaddr_fromin(&addrs[i], &sin->sin_addr, port);
182 		} else {
183 			struct sockaddr_in6 *sin6;
184 			sin6 = (struct sockaddr_in6 *)tmpai->ai_addr;
185 			isc_sockaddr_fromin6(&addrs[i], &sin6->sin6_addr,
186 					     port);
187 		}
188 		i++;
189 
190 	}
191 	freeaddrinfo(ai);
192 	*addrcount = i;
193 #else
194 	he = gethostbyname(hostname);
195 	if (he == NULL) {
196 		switch (h_errno) {
197 		case HOST_NOT_FOUND:
198 #ifdef NO_DATA
199 		case NO_DATA:
200 #endif
201 #if defined(NO_ADDRESS) && (!defined(NO_DATA) || (NO_DATA != NO_ADDRESS))
202 		case NO_ADDRESS:
203 #endif
204 			return (ISC_R_NOTFOUND);
205 		default:
206 			return (ISC_R_FAILURE);
207 		}
208 	}
209 	if (he->h_addrtype != AF_INET && he->h_addrtype != AF_INET6)
210 		return (ISC_R_NOTFOUND);
211 	for (i = 0; i < addrsize; i++) {
212 		if (he->h_addrtype == AF_INET) {
213 			struct in_addr *inp;
214 			inp = (struct in_addr *)(he->h_addr_list[i]);
215 			if (inp == NULL)
216 				break;
217 			isc_sockaddr_fromin(&addrs[i], inp, port);
218 		} else {
219 			struct in6_addr *in6p;
220 			in6p = (struct in6_addr *)(he->h_addr_list[i]);
221 			if (in6p == NULL)
222 				break;
223 			isc_sockaddr_fromin6(&addrs[i], in6p, port);
224 		}
225 	}
226 	*addrcount = i;
227 #endif
228 	if (*addrcount == 0)
229 		return (ISC_R_NOTFOUND);
230 	else
231 		return (ISC_R_SUCCESS);
232 }
233