1 /* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 itojun Exp $ */
4 * SPDX-License-Identifier: BSD-3-Clause
6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7 * Copyright (c) 2000 Ben Harris.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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 * 3. Neither the name of the project nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * Issues to be discussed:
37 * - Thread safe-ness must be checked
38 * - RFC2553 says that we should raise error on short buffer. X/Open says
39 * we need to truncate the result. We obey RFC2553 (and X/Open should be
40 * modified). ipngwg rough consensus seems to follow RFC2553.
41 * - What is "local" in NI_FQDN?
42 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
43 * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if
44 * sin6_scope_id is filled - standardization status?
45 * XXX breaks backward compat for code that expects no scopeid.
49 #include <sys/cdefs.h>
50 __FBSDID("$FreeBSD$");
52 #include <sys/types.h>
53 #include <sys/socket.h>
56 #include <net/if_dl.h>
57 #include <net/if_types.h>
58 #include <net/firewire.h>
59 #include <netinet/in.h>
60 #include <arpa/inet.h>
61 #include <arpa/nameser.h>
68 static const struct afd *find_afd(int);
69 static int getnameinfo_inet(const struct afd *,
70 const struct sockaddr *, socklen_t, char *,
71 size_t, char *, size_t, int);
73 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *,
75 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int);
77 static int getnameinfo_link(const struct afd *,
78 const struct sockaddr *, socklen_t, char *,
79 size_t, char *, size_t, int);
80 static int hexname(const u_int8_t *, size_t, char *, size_t);
81 static int getnameinfo_un(const struct afd *,
82 const struct sockaddr *, socklen_t, char *,
83 size_t, char *, size_t, int);
85 static const struct afd {
90 int (*a_func)(const struct afd *,
91 const struct sockaddr *, socklen_t, char *,
92 size_t, char *, size_t, int);
95 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
96 offsetof(struct sockaddr_in6, sin6_addr),
99 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
100 offsetof(struct sockaddr_in, sin_addr),
102 #define sizeofmember(type, member) (sizeof(((type *)0)->member))
103 {PF_LOCAL, sizeofmember(struct sockaddr_un, sun_path),
104 sizeof(struct sockaddr_un),
105 offsetof(struct sockaddr_un, sun_path),
107 {PF_LINK, sizeofmember(struct sockaddr_dl, sdl_data),
108 sizeof(struct sockaddr_dl),
109 offsetof(struct sockaddr_dl, sdl_data),
115 getnameinfo(const struct sockaddr *sa, socklen_t salen,
116 char *host, size_t hostlen, char *serv, size_t servlen,
119 const struct afd *afd;
124 afd = find_afd(sa->sa_family);
128 * getnameinfo() accepts an salen of sizeof(struct sockaddr_storage)
129 * at maximum as shown in RFC 4038 Sec.6.2.3.
131 if (salen > sizeof(struct sockaddr_storage))
134 switch (sa->sa_family) {
137 * PF_LOCAL uses variable salen depending on the
138 * content length of sun_path. Require 1 byte in
141 if (salen <= afd->a_socklen -
142 sizeofmember(struct sockaddr_un, sun_path))
144 else if (salen > afd->a_socklen)
145 salen = afd->a_socklen;
148 if (salen <= afd->a_socklen -
149 sizeofmember(struct sockaddr_dl, sdl_data))
153 if (salen < afd->a_socklen)
156 salen = afd->a_socklen;
160 return ((*afd->a_func)(afd, sa, salen, host, hostlen,
161 serv, servlen, flags));
164 static const struct afd *
167 const struct afd *afd;
171 for (afd = &afdl[0]; afd->a_af > 0; afd++) {
179 getnameinfo_inet(const struct afd *afd,
180 const struct sockaddr *sa, socklen_t salen,
181 char *host, size_t hostlen, char *serv, size_t servlen,
193 /* network byte order */
194 port = ((const struct sockaddr_in *)sa)->sin_port;
195 addr = (const char *)sa + afd->a_off;
197 if (serv == NULL || servlen == 0) {
199 * do nothing in this case.
200 * in case you are wondering if "&&" is more correct than
201 * "||" here: rfc2553bis-03 says that serv == NULL OR
202 * servlen == 0 means that the caller does not want the result.
205 if (flags & NI_NUMERICSERV)
208 sp = getservbyport(port,
209 (flags & NI_DGRAM) ? "udp" : "tcp");
212 if (strlen(sp->s_name) + 1 > servlen)
214 strlcpy(serv, sp->s_name, servlen);
216 snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
217 if (strlen(numserv) + 1 > servlen)
219 strlcpy(serv, numserv, servlen);
223 switch (sa->sa_family) {
226 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr);
227 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a) ||
229 flags |= NI_NUMERICHOST;
234 const struct sockaddr_in6 *sin6;
235 sin6 = (const struct sockaddr_in6 *)sa;
236 switch (sin6->sin6_addr.s6_addr[0]) {
238 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
240 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
243 flags |= NI_NUMERICHOST;
246 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
247 flags |= NI_NUMERICHOST;
249 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
250 flags |= NI_NUMERICHOST;
257 if (host == NULL || hostlen == 0) {
259 * do nothing in this case.
260 * in case you are wondering if "&&" is more correct than
261 * "||" here: rfc2553bis-03 says that host == NULL or
262 * hostlen == 0 means that the caller does not want the result.
264 } else if (flags & NI_NUMERICHOST) {
267 /* NUMERICHOST and NAMEREQD conflicts with each other */
268 if (flags & NI_NAMEREQD)
277 if ((error = ip6_parsenumeric(sa, addr, host,
278 hostlen, flags)) != 0)
284 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
287 numaddrlen = strlen(numaddr);
288 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
290 strlcpy(host, numaddr, hostlen);
294 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
299 * commented out, since "for local host" is not
300 * implemented here - see RFC2553 p30
302 if (flags & NI_NOFQDN) {
304 p = strchr(hp->h_name, '.');
309 if (strlen(hp->h_name) + 1 > hostlen) {
313 strlcpy(host, hp->h_name, hostlen);
316 if (flags & NI_NAMEREQD)
324 if ((error = ip6_parsenumeric(sa, addr, host,
332 if (inet_ntop(afd->a_af, addr, host,
344 ip6_parsenumeric(const struct sockaddr *sa, const char *addr,
345 char *host, size_t hostlen, int flags)
350 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL)
353 numaddrlen = strlen(numaddr);
354 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
356 strlcpy(host, numaddr, hostlen);
358 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) {
359 char zonebuf[MAXHOSTNAMELEN];
362 zonelen = ip6_sa2str(
363 (const struct sockaddr_in6 *)(const void *)sa,
364 zonebuf, sizeof(zonebuf), flags);
367 if (zonelen + 1 + numaddrlen + 1 > hostlen)
370 /* construct <numeric-addr><delim><zoneid> */
371 memcpy(host + numaddrlen + 1, zonebuf,
373 host[numaddrlen] = SCOPE_DELIMITER;
374 host[numaddrlen + 1 + zonelen] = '\0';
382 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags)
384 unsigned int ifindex;
385 const struct in6_addr *a6;
388 ifindex = (unsigned int)sa6->sin6_scope_id;
389 a6 = &sa6->sin6_addr;
391 if ((flags & NI_NUMERICSCOPE) != 0) {
392 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
393 if (n < 0 || n >= bufsiz)
399 /* if_indextoname() does not take buffer size. not a good api... */
400 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) ||
401 IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) {
402 char *p = if_indextoname(ifindex, buf);
409 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id);
410 if (n < 0 || (size_t)n >= bufsiz)
418 * getnameinfo_link():
419 * Format a link-layer address into a printable format, paying attention to
420 * the interface type.
424 getnameinfo_link(const struct afd *afd,
425 const struct sockaddr *sa, socklen_t salen,
426 char *host, size_t hostlen, char *serv, size_t servlen, int flags)
428 const struct sockaddr_dl *sdl =
429 (const struct sockaddr_dl *)(const void *)sa;
430 const struct fw_hwaddr *iha;
433 if (serv != NULL && servlen > 0)
436 if (sdl->sdl_nlen == 0 && sdl->sdl_alen == 0 && sdl->sdl_slen == 0) {
437 n = snprintf(host, hostlen, "link#%d", sdl->sdl_index);
445 if (sdl->sdl_nlen > 0 && sdl->sdl_alen == 0) {
451 memcpy(host, sdl->sdl_data, sdl->sdl_nlen);
456 switch (sdl->sdl_type) {
458 if (sdl->sdl_alen < sizeof(iha->sender_unique_ID_hi) +
459 sizeof(iha->sender_unique_ID_lo))
461 iha = (const struct fw_hwaddr *)(const void *)LLADDR(sdl);
462 return hexname((const u_int8_t *)&iha->sender_unique_ID_hi,
463 sizeof(iha->sender_unique_ID_hi) +
464 sizeof(iha->sender_unique_ID_lo),
467 * The following have zero-length addresses.
468 * IFT_GIF (net/if_gif.c)
469 * IFT_LOOP (net/if_loop.c)
470 * IFT_PPP (net/if_ppp.c, net/if_spppsubr.c)
471 * IFT_SLIP (net/if_sl.c, net/if_strip.c)
472 * IFT_STF (net/if_stf.c)
473 * IFT_L2VLAN (net/if_vlan.c)
474 * IFT_BRIDGE (net/if_bridge.h>
477 * The following use IPv4 addresses as link-layer addresses:
478 * IFT_OTHER (net/if_gre.c)
479 * IFT_OTHER (netinet/ip_ipip.c)
481 /* default below is believed correct for all these. */
487 return hexname((u_int8_t *)LLADDR(sdl), (size_t)sdl->sdl_alen,
493 hexname(const u_int8_t *cp, size_t len, char *host, size_t hostlen)
499 for (i = 0; i < len; i++) {
500 n = snprintf(outp, hostlen, "%s%02x",
501 i ? ":" : "", cp[i]);
502 if (n < 0 || n >= hostlen) {
514 * Format a UNIX IPC domain address (pathname).
518 getnameinfo_un(const struct afd *afd,
519 const struct sockaddr *sa, socklen_t salen,
520 char *host, size_t hostlen, char *serv, size_t servlen, int flags)
524 if (serv != NULL && servlen > 0)
526 if (host != NULL && hostlen > 0) {
527 pathlen = salen - afd->a_off;
529 if (pathlen + 1 > hostlen) {
533 strlcpy(host, (const char *)sa + afd->a_off, pathlen + 1);