1 /* $FreeBSD: src/lib/libc/net/getnameinfo.c,v 1.20 2007/02/28 21:18:38 bms Exp $ */
2 /* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 itojun Exp $ */
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * Copyright (c) 2000 Ben Harris.
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 <net/if_dl.h>
52 #include <net/if_types.h>
53 #include <netinet/in.h>
54 #include <arpa/inet.h>
55 #include <arpa/nameser.h>
62 static int getnameinfo_inet(const struct sockaddr *, socklen_t, char *,
63 size_t, char *, size_t, int);
65 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *,
67 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int);
69 static int getnameinfo_link(const struct sockaddr *, socklen_t, char *,
70 size_t, char *, size_t, int);
71 static int hexname(const u_int8_t *, size_t, char *, size_t);
74 getnameinfo(const struct sockaddr * __restrict sa, socklen_t salen,
75 char * __restrict host, size_t hostlen, char * __restrict serv,
76 size_t servlen, int flags)
79 switch (sa->sa_family) {
84 return getnameinfo_inet(sa, salen, host, hostlen, serv,
87 return getnameinfo_link(sa, salen, host, hostlen, serv,
94 static const struct afd {
101 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
102 offsetof(struct sockaddr_in6, sin6_addr)},
104 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
105 offsetof(struct sockaddr_in, sin_addr)},
116 getnameinfo_inet(const struct sockaddr *sa, socklen_t salen, char *host,
117 size_t hostlen, char *serv, size_t servlen, int flags)
119 const struct afd *afd;
133 family = sa->sa_family;
134 for (i = 0; afdl[i].a_af; i++)
135 if (afdl[i].a_af == family) {
142 if (salen != afd->a_socklen)
145 /* network byte order */
146 port = ((const struct sockinet *)sa)->si_port;
147 addr = (const char *)sa + afd->a_off;
149 if (serv == NULL || servlen == 0) {
151 * do nothing in this case.
152 * in case you are wondering if "&&" is more correct than
153 * "||" here: rfc2553bis-03 says that serv == NULL OR
154 * servlen == 0 means that the caller does not want the result.
157 if (flags & NI_NUMERICSERV)
160 sp = getservbyport(port,
161 (flags & NI_DGRAM) ? "udp" : "tcp");
164 if (strlen(sp->s_name) + 1 > servlen)
166 strlcpy(serv, sp->s_name, servlen);
168 snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
169 if (strlen(numserv) + 1 > servlen)
171 strlcpy(serv, numserv, servlen);
175 switch (sa->sa_family) {
178 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr);
179 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
180 flags |= NI_NUMERICHOST;
181 v4a >>= IN_CLASSA_NSHIFT;
183 flags |= NI_NUMERICHOST;
188 const struct sockaddr_in6 *sin6;
189 sin6 = (const struct sockaddr_in6 *)sa;
190 switch (sin6->sin6_addr.s6_addr[0]) {
192 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
194 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
197 flags |= NI_NUMERICHOST;
200 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
201 flags |= NI_NUMERICHOST;
203 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
204 flags |= NI_NUMERICHOST;
211 if (host == NULL || hostlen == 0) {
213 * do nothing in this case.
214 * in case you are wondering if "&&" is more correct than
215 * "||" here: rfc2553bis-03 says that host == NULL or
216 * hostlen == 0 means that the caller does not want the result.
218 } else if (flags & NI_NUMERICHOST) {
221 /* NUMERICHOST and NAMEREQD conflicts with each other */
222 if (flags & NI_NAMEREQD)
231 if ((error = ip6_parsenumeric(sa, addr, host,
232 hostlen, flags)) != 0)
238 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
241 numaddrlen = strlen(numaddr);
242 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
244 strlcpy(host, numaddr, hostlen);
248 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
253 * commented out, since "for local host" is not
254 * implemented here - see RFC2553 p30
256 if (flags & NI_NOFQDN) {
258 p = strchr(hp->h_name, '.');
263 if (strlen(hp->h_name) + 1 > hostlen) {
267 strlcpy(host, hp->h_name, hostlen);
270 if (flags & NI_NAMEREQD)
278 if ((error = ip6_parsenumeric(sa, addr, host,
286 if (inet_ntop(afd->a_af, addr, host,
298 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host,
299 size_t hostlen, int flags)
304 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
307 numaddrlen = strlen(numaddr);
308 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
310 strlcpy(host, numaddr, hostlen);
312 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) {
313 char zonebuf[MAXHOSTNAMELEN];
316 zonelen = ip6_sa2str(
317 (const struct sockaddr_in6 *)(const void *)sa,
318 zonebuf, sizeof(zonebuf), flags);
321 if (zonelen + 1 + numaddrlen + 1 > hostlen)
324 /* construct <numeric-addr><delim><zoneid> */
325 memcpy(host + numaddrlen + 1, zonebuf,
327 host[numaddrlen] = SCOPE_DELIMITER;
328 host[numaddrlen + 1 + zonelen] = '\0';
336 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz,
339 unsigned int ifindex;
340 const struct in6_addr *a6;
343 ifindex = (unsigned int)sa6->sin6_scope_id;
344 a6 = &sa6->sin6_addr;
346 if ((flags & NI_NUMERICSCOPE) != 0) {
347 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
348 if (n < 0 || n >= bufsiz)
354 /* if_indextoname() does not take buffer size. not a good api... */
355 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
356 IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) {
357 char *p = if_indextoname(ifindex, buf);
364 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
365 if (n < 0 || (size_t)n >= bufsiz)
373 * getnameinfo_link():
374 * Format a link-layer address into a printable format, paying attention to
375 * the interface type.
379 getnameinfo_link(const struct sockaddr *sa, socklen_t salen __unused,
380 char *host, size_t hostlen, char *serv, size_t servlen,
383 const struct sockaddr_dl *sdl =
384 (const struct sockaddr_dl *)(const void *)sa;
387 if (serv != NULL && servlen > 0)
390 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) {
391 n = snprintf(host, hostlen, "link#%d", sdl->sdl_index);
399 switch (sdl->sdl_type) {
401 * The following have zero-length addresses.
402 * IFT_GIF (net/gif/if_gif.c)
403 * IFT_LOOP (net/if_loop.c, net/disc/if_disc.c)
404 * IFT_PPP (net/sppp/if_spppsubr.c)
405 * IFT_SLIP (net/sl/if_sl.c)
406 * IFT_STF (net/stf/if_stf.c)
407 * IFT_L2VLAN (net/vlan/if_vlan.c)
408 * IFT_BRIDGE (net/bridge/if_bridge.c)
411 * The following use IPv4 addresses as link-layer addresses:
412 * IFT_OTHER (net/gre/if_gre.c)
413 * IFT_OTHER (netproto/ipsec/xform_ipip.c)
415 /* default below is believed correct for all these. */
422 return hexname((u_int8_t *)LLADDR(sdl), (size_t)sdl->sdl_alen,
428 hexname(const u_int8_t *cp, size_t len, char *host, size_t hostlen)
434 for (i = 0; i < len; i++) {
435 n = snprintf(outp, hostlen, "%s%02x",
436 i ? ":" : "", cp[i]);
437 if (n < 0 || n >= hostlen) {