1 /* $FreeBSD: src/lib/libc/net/getnameinfo.c,v 1.4.2.5 2002/07/31 10:11:09 ume Exp $ */
2 /* $DragonFly: src/lib/libc/net/getnameinfo.c,v 1.4 2005/11/13 02:04:47 swildner Exp $ */
3 /* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 itojun Exp $ */
6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the project nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * Issues to be discussed:
36 * - Thread safe-ness must be checked
37 * - RFC2553 says that we should raise error on short buffer. X/Open says
38 * we need to truncate the result. We obey RFC2553 (and X/Open should be
39 * modified). ipngwg rough consensus seems to follow RFC2553.
40 * - What is "local" in NI_FQDN?
41 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
42 * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if
43 * sin6_scope_id is filled - standardization status?
44 * XXX breaks backward compat for code that expects no scopeid.
48 #include <sys/types.h>
49 #include <sys/socket.h>
51 #include <netinet/in.h>
52 #include <arpa/inet.h>
53 #include <arpa/nameser.h>
60 static const struct afd {
67 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
68 offsetof(struct sockaddr_in6, sin6_addr)},
70 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
71 offsetof(struct sockaddr_in, sin_addr)},
82 static int ip6_parsenumeric (const struct sockaddr *, const char *, char *,
84 static int ip6_sa2str (const struct sockaddr_in6 *, char *, size_t, int);
88 getnameinfo(const struct sockaddr *sa, socklen_t salen, char *host,
89 size_t hostlen, char *serv, size_t servlen, int flags)
91 const struct afd *afd;
105 if (sa->sa_len != salen)
108 family = sa->sa_family;
109 for (i = 0; afdl[i].a_af; i++)
110 if (afdl[i].a_af == family) {
117 if (salen != afd->a_socklen)
120 /* network byte order */
121 port = ((const struct sockinet *)sa)->si_port;
122 addr = (const char *)sa + afd->a_off;
124 if (serv == NULL || servlen == 0) {
126 * do nothing in this case.
127 * in case you are wondering if "&&" is more correct than
128 * "||" here: rfc2553bis-03 says that serv == NULL OR
129 * servlen == 0 means that the caller does not want the result.
132 if (flags & NI_NUMERICSERV)
135 sp = getservbyport(port,
136 (flags & NI_DGRAM) ? "udp" : "tcp");
139 if (strlen(sp->s_name) + 1 > servlen)
141 strlcpy(serv, sp->s_name, servlen);
143 snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
144 if (strlen(numserv) + 1 > servlen)
146 strlcpy(serv, numserv, servlen);
150 switch (sa->sa_family) {
153 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr);
154 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
155 flags |= NI_NUMERICHOST;
156 v4a >>= IN_CLASSA_NSHIFT;
158 flags |= NI_NUMERICHOST;
163 const struct sockaddr_in6 *sin6;
164 sin6 = (const struct sockaddr_in6 *)sa;
165 switch (sin6->sin6_addr.s6_addr[0]) {
167 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
169 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
172 flags |= NI_NUMERICHOST;
175 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
176 flags |= NI_NUMERICHOST;
178 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
179 flags |= NI_NUMERICHOST;
186 if (host == NULL || hostlen == 0) {
188 * do nothing in this case.
189 * in case you are wondering if "&&" is more correct than
190 * "||" here: rfc2553bis-03 says that host == NULL or
191 * hostlen == 0 means that the caller does not want the result.
193 } else if (flags & NI_NUMERICHOST) {
196 /* NUMERICHOST and NAMEREQD conflicts with each other */
197 if (flags & NI_NAMEREQD)
206 if ((error = ip6_parsenumeric(sa, addr, host,
207 hostlen, flags)) != 0)
213 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
216 numaddrlen = strlen(numaddr);
217 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
219 strlcpy(host, numaddr, hostlen);
223 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
228 * commented out, since "for local host" is not
229 * implemented here - see RFC2553 p30
231 if (flags & NI_NOFQDN) {
233 p = strchr(hp->h_name, '.');
238 if (strlen(hp->h_name) + 1 > hostlen) {
242 strlcpy(host, hp->h_name, hostlen);
245 if (flags & NI_NAMEREQD)
253 if ((error = ip6_parsenumeric(sa, addr, host,
261 if (inet_ntop(afd->a_af, addr, host,
273 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host,
274 size_t hostlen, int flags)
279 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
282 numaddrlen = strlen(numaddr);
283 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
285 strlcpy(host, numaddr, hostlen);
287 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) {
288 char zonebuf[MAXHOSTNAMELEN];
291 zonelen = ip6_sa2str(
292 (const struct sockaddr_in6 *)(const void *)sa,
293 zonebuf, sizeof(zonebuf), flags);
296 if (zonelen + 1 + numaddrlen + 1 > hostlen)
299 /* construct <numeric-addr><delim><zoneid> */
300 memcpy(host + numaddrlen + 1, zonebuf,
302 host[numaddrlen] = SCOPE_DELIMITER;
303 host[numaddrlen + 1 + zonelen] = '\0';
311 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags)
313 unsigned int ifindex;
314 const struct in6_addr *a6;
317 ifindex = (unsigned int)sa6->sin6_scope_id;
318 a6 = &sa6->sin6_addr;
320 #ifdef NI_NUMERICSCOPE
321 if ((flags & NI_NUMERICSCOPE) != 0) {
322 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
323 if (n < 0 || n >= bufsiz)
330 /* if_indextoname() does not take buffer size. not a good api... */
331 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
332 IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) {
333 char *p = if_indextoname(ifindex, buf);
340 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
341 if (n < 0 || n >= bufsiz)