1 /* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 itojun Exp $ */
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * Copyright (c) 2000 Ben Harris.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * Issues to be discussed:
35 * - Thread safe-ness must be checked
36 * - RFC2553 says that we should raise error on short buffer. X/Open says
37 * we need to truncate the result. We obey RFC2553 (and X/Open should be
38 * modified). ipngwg rough consensus seems to follow RFC2553.
39 * - What is "local" in NI_FQDN?
40 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
41 * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if
42 * sin6_scope_id is filled - standardization status?
43 * XXX breaks backward compat for code that expects no scopeid.
47 #include <sys/cdefs.h>
48 __FBSDID("$FreeBSD$");
50 #include <sys/types.h>
51 #include <sys/socket.h>
53 #include <net/if_dl.h>
54 #include <net/if_types.h>
55 #include <netinet/in.h>
56 #include <arpa/inet.h>
57 #include <arpa/nameser.h>
64 static int getnameinfo_inet(const struct sockaddr *, socklen_t, char *,
65 size_t, char *, size_t, int);
67 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *,
69 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int);
71 static int getnameinfo_link(const struct sockaddr *, socklen_t, char *,
72 size_t, char *, size_t, int);
73 static int hexname(const u_int8_t *, size_t, char *, size_t);
76 getnameinfo(const struct sockaddr *sa, socklen_t salen,
77 char *host, size_t hostlen, char *serv, size_t servlen,
81 switch (sa->sa_family) {
86 return getnameinfo_inet(sa, salen, host, hostlen, serv,
89 return getnameinfo_link(sa, salen, host, hostlen, serv,
96 static const struct afd {
103 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
104 offsetof(struct sockaddr_in6, sin6_addr)},
106 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
107 offsetof(struct sockaddr_in, sin_addr)},
118 getnameinfo_inet(const struct sockaddr *sa, socklen_t salen,
119 char *host, size_t hostlen, char *serv, size_t servlen,
122 const struct afd *afd;
136 family = sa->sa_family;
137 for (i = 0; afdl[i].a_af; i++)
138 if (afdl[i].a_af == family) {
145 if (salen != afd->a_socklen)
148 /* network byte order */
149 port = ((const struct sockinet *)sa)->si_port;
150 addr = (const char *)sa + afd->a_off;
152 if (serv == NULL || servlen == 0) {
154 * do nothing in this case.
155 * in case you are wondering if "&&" is more correct than
156 * "||" here: rfc2553bis-03 says that serv == NULL OR
157 * servlen == 0 means that the caller does not want the result.
160 if (flags & NI_NUMERICSERV)
163 sp = getservbyport(port,
164 (flags & NI_DGRAM) ? "udp" : "tcp");
167 if (strlen(sp->s_name) + 1 > servlen)
169 strlcpy(serv, sp->s_name, servlen);
171 snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
172 if (strlen(numserv) + 1 > servlen)
174 strlcpy(serv, numserv, servlen);
178 switch (sa->sa_family) {
181 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr);
182 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
183 flags |= NI_NUMERICHOST;
184 v4a >>= IN_CLASSA_NSHIFT;
186 flags |= NI_NUMERICHOST;
191 const struct sockaddr_in6 *sin6;
192 sin6 = (const struct sockaddr_in6 *)sa;
193 switch (sin6->sin6_addr.s6_addr[0]) {
195 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
197 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
200 flags |= NI_NUMERICHOST;
203 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
204 flags |= NI_NUMERICHOST;
206 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
207 flags |= NI_NUMERICHOST;
214 if (host == NULL || hostlen == 0) {
216 * do nothing in this case.
217 * in case you are wondering if "&&" is more correct than
218 * "||" here: rfc2553bis-03 says that host == NULL or
219 * hostlen == 0 means that the caller does not want the result.
221 } else if (flags & NI_NUMERICHOST) {
224 /* NUMERICHOST and NAMEREQD conflicts with each other */
225 if (flags & NI_NAMEREQD)
234 if ((error = ip6_parsenumeric(sa, addr, host,
235 hostlen, flags)) != 0)
241 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
244 numaddrlen = strlen(numaddr);
245 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
247 strlcpy(host, numaddr, hostlen);
251 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
256 * commented out, since "for local host" is not
257 * implemented here - see RFC2553 p30
259 if (flags & NI_NOFQDN) {
261 p = strchr(hp->h_name, '.');
266 if (strlen(hp->h_name) + 1 > hostlen) {
270 strlcpy(host, hp->h_name, hostlen);
273 if (flags & NI_NAMEREQD)
281 if ((error = ip6_parsenumeric(sa, addr, host,
289 if (inet_ntop(afd->a_af, addr, host,
301 ip6_parsenumeric(const struct sockaddr *sa, const char *addr,
302 char *host, size_t hostlen, int flags)
307 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
310 numaddrlen = strlen(numaddr);
311 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
313 strlcpy(host, numaddr, hostlen);
315 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) {
316 char zonebuf[MAXHOSTNAMELEN];
319 zonelen = ip6_sa2str(
320 (const struct sockaddr_in6 *)(const void *)sa,
321 zonebuf, sizeof(zonebuf), flags);
324 if (zonelen + 1 + numaddrlen + 1 > hostlen)
327 /* construct <numeric-addr><delim><zoneid> */
328 memcpy(host + numaddrlen + 1, zonebuf,
330 host[numaddrlen] = SCOPE_DELIMITER;
331 host[numaddrlen + 1 + zonelen] = '\0';
339 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags)
341 unsigned int ifindex;
342 const struct in6_addr *a6;
345 ifindex = (unsigned int)sa6->sin6_scope_id;
346 a6 = &sa6->sin6_addr;
348 #ifdef NI_NUMERICSCOPE
349 if ((flags & NI_NUMERICSCOPE) != 0) {
350 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
351 if (n < 0 || n >= bufsiz)
358 /* if_indextoname() does not take buffer size. not a good api... */
359 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
360 IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) {
361 char *p = if_indextoname(ifindex, buf);
368 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
369 if (n < 0 || (size_t)n >= bufsiz)
377 * getnameinfo_link():
378 * Format a link-layer address into a printable format, paying attention to
379 * the interface type.
383 getnameinfo_link(const struct sockaddr *sa, socklen_t salen,
384 char *host, size_t hostlen, char *serv, size_t servlen, int flags)
386 const struct sockaddr_dl *sdl =
387 (const struct sockaddr_dl *)(const void *)sa;
390 if (serv != NULL && servlen > 0)
393 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) {
394 n = snprintf(host, hostlen, "link#%d", sdl->sdl_index);
402 switch (sdl->sdl_type) {
404 * The following have zero-length addresses.
405 * IFT_ATM (net/if_atmsubr.c)
406 * IFT_FAITH (net/if_faith.c)
407 * IFT_GIF (net/if_gif.c)
408 * IFT_LOOP (net/if_loop.c)
409 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c)
410 * IFT_SLIP (net/if_sl.c, net/if_strip.c)
411 * IFT_STF (net/if_stf.c)
412 * IFT_L2VLAN (net/if_vlan.c)
413 * IFT_BRIDGE (net/if_bridge.h>
416 * The following use IPv4 addresses as link-layer addresses:
417 * IFT_OTHER (net/if_gre.c)
418 * IFT_OTHER (netinet/ip_ipip.c)
420 /* default below is believed correct for all these. */
427 return hexname((u_int8_t *)LLADDR(sdl), (size_t)sdl->sdl_alen,
433 hexname(cp, len, host, hostlen)
442 for (i = 0; i < len; i++) {
443 n = snprintf(outp, hostlen, "%s%02x",
444 i ? ":" : "", cp[i]);
445 if (n < 0 || n >= hostlen) {