1/*	$NetBSD$	*/
2
3/*
4 * Issues to be discussed:
5 * - Thread safe-ness must be checked
6 */
7
8#if ( defined(__linux__) || defined(__linux) || defined(LINUX) )
9#ifndef IF_NAMESIZE
10# ifdef IFNAMSIZ
11#  define IF_NAMESIZE  IFNAMSIZ
12# else
13#  define IF_NAMESIZE 16
14# endif
15#endif
16#endif
17
18/*
19 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
20 * All rights reserved.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 *    notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 *    notice, this list of conditions and the following disclaimer in the
29 *    documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 *    must display the following acknowledgement:
32 *    This product includes software developed by WIDE Project and
33 *    its contributors.
34 * 4. Neither the name of the project nor the names of its contributors
35 *    may be used to endorse or promote products derived from this software
36 *    without specific prior written permission.
37 *
38 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
39 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
41 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
42 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
43 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
44 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
45 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
46 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
47 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
48 * SUCH DAMAGE.
49 */
50
51#include <port_before.h>
52
53#include <sys/types.h>
54#include <sys/socket.h>
55
56#include <netinet/in.h>
57#include <arpa/nameser.h>
58#include <arpa/inet.h>
59#include <net/if.h>
60
61#include <netdb.h>
62#include <resolv.h>
63#include <string.h>
64#include <stddef.h>
65
66#include <port_after.h>
67
68/*%
69 * Note that a_off will be dynamically adjusted so that to be consistent
70 * with the definition of sockaddr_in{,6}.
71 * The value presented below is just a guess.
72 */
73static struct afd {
74	int a_af;
75	int a_addrlen;
76	size_t a_socklen;
77	int a_off;
78} afdl [] = {
79	/* first entry is linked last... */
80	{PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
81	 offsetof(struct sockaddr_in, sin_addr)},
82	{PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
83	 offsetof(struct sockaddr_in6, sin6_addr)},
84	{0, 0, 0, 0},
85};
86
87struct sockinet {
88#ifdef HAVE_SA_LEN
89	u_char	si_len;
90#endif
91	u_char	si_family;
92	u_short	si_port;
93};
94
95static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *,
96				 size_t, int));
97#ifdef HAVE_SIN6_SCOPE_ID
98static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int));
99#endif
100
101int
102getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
103	const struct sockaddr *sa;
104	size_t salen;
105	char *host;
106	size_t hostlen;
107	char *serv;
108	size_t servlen;
109	int flags;
110{
111	struct afd *afd;
112	struct servent *sp;
113	struct hostent *hp;
114	u_short port;
115#ifdef HAVE_SA_LEN
116	size_t len;
117#endif
118	int family, i;
119	const char *addr;
120	char *p;
121	char numserv[512];
122	char numaddr[512];
123	const struct sockaddr_in6 *sin6;
124
125	if (sa == NULL)
126		return EAI_FAIL;
127
128#ifdef HAVE_SA_LEN
129	len = sa->sa_len;
130	if (len != salen) return EAI_FAIL;
131#endif
132
133	family = sa->sa_family;
134	for (i = 0; afdl[i].a_af; i++)
135		if (afdl[i].a_af == family) {
136			afd = &afdl[i];
137			goto found;
138		}
139	return EAI_FAMILY;
140
141 found:
142	if (salen != afd->a_socklen) return EAI_FAIL;
143
144	port = ((const struct sockinet *)sa)->si_port; /*%< network byte order */
145	addr = (const char *)sa + afd->a_off;
146
147	if (serv == NULL || servlen == 0U) {
148		/*
149		 * rfc2553bis says that serv == NULL or servlen == 0 means that
150		 * the caller does not want the result.
151		 */
152	} else if (flags & NI_NUMERICSERV) {
153		sprintf(numserv, "%d", ntohs(port));
154		if (strlen(numserv) > servlen)
155			return EAI_MEMORY;
156		strcpy(serv, numserv);
157	} else {
158		sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp");
159		if (sp) {
160			if (strlen(sp->s_name) + 1 > servlen)
161				return EAI_MEMORY;
162			strcpy(serv, sp->s_name);
163		} else
164			return EAI_NONAME;
165	}
166
167	switch (sa->sa_family) {
168	case AF_INET:
169		if (ntohl(*(const u_int32_t *)addr) >> IN_CLASSA_NSHIFT == 0)
170			flags |= NI_NUMERICHOST;
171		break;
172	case AF_INET6:
173		sin6 = (const struct sockaddr_in6 *)sa;
174		switch (sin6->sin6_addr.s6_addr[0]) {
175		case 0x00:
176			if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
177				;
178			else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
179				;
180			else
181				flags |= NI_NUMERICHOST;
182			break;
183		default:
184			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
185				flags |= NI_NUMERICHOST;
186			else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
187				flags |= NI_NUMERICHOST;
188			break;
189		}
190		break;
191	}
192	if (host == NULL || hostlen == 0U) {
193		/*
194		 * rfc2553bis says that host == NULL or hostlen == 0 means that
195		 * the caller does not want the result.
196		 */
197	} else if (flags & NI_NUMERICHOST) {
198		goto numeric;
199	} else {
200		hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
201
202		if (hp) {
203			if (flags & NI_NOFQDN) {
204				p = strchr(hp->h_name, '.');
205				if (p) *p = '\0';
206			}
207			if (strlen(hp->h_name) + 1 > hostlen)
208				return EAI_MEMORY;
209			strcpy(host, hp->h_name);
210		} else {
211			if (flags & NI_NAMEREQD)
212				return EAI_NONAME;
213		  numeric:
214			switch(afd->a_af) {
215			case AF_INET6:
216			{
217				int error;
218
219				if ((error = ip6_parsenumeric(sa, addr, host,
220							      hostlen,
221							      flags)) != 0)
222					return(error);
223				break;
224			}
225
226			default:
227				if (inet_ntop(afd->a_af, addr, numaddr,
228					      sizeof(numaddr)) == NULL)
229					return EAI_NONAME;
230				if (strlen(numaddr) + 1 > hostlen)
231					return EAI_MEMORY;
232				strcpy(host, numaddr);
233			}
234		}
235	}
236	return(0);
237}
238
239static int
240ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host,
241		 size_t hostlen, int flags)
242{
243	size_t numaddrlen;
244	char numaddr[512];
245
246#ifndef HAVE_SIN6_SCOPE_ID
247	UNUSED(sa);
248	UNUSED(flags);
249#endif
250
251	if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr))
252	    == NULL)
253		return EAI_SYSTEM;
254
255	numaddrlen = strlen(numaddr);
256	if (numaddrlen + 1 > hostlen) /*%< don't forget terminator */
257		return EAI_MEMORY;
258	strcpy(host, numaddr);
259
260#ifdef HAVE_SIN6_SCOPE_ID
261	if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) {
262		char scopebuf[MAXHOSTNAMELEN]; /*%< XXX */
263		int scopelen;
264
265		/* ip6_sa2str never fails */
266		scopelen = ip6_sa2str((const struct sockaddr_in6 *)sa,
267				      scopebuf, sizeof(scopebuf), flags);
268
269		if (scopelen + 1 + numaddrlen + 1 > hostlen)
270			return EAI_MEMORY;
271
272		/* construct <numeric-addr><delim><scopeid> */
273		memcpy(host + numaddrlen + 1, scopebuf,
274		       scopelen);
275		host[numaddrlen] = SCOPE_DELIMITER;
276		host[numaddrlen + 1 + scopelen] = '\0';
277	}
278#endif
279
280	return 0;
281}
282
283#ifdef HAVE_SIN6_SCOPE_ID
284/* ARGSUSED */
285static int
286ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf,
287	   size_t bufsiz, int flags)
288{
289#ifdef USE_IFNAMELINKID
290	unsigned int ifindex = (unsigned int)sa6->sin6_scope_id;
291	const struct in6_addr *a6 = &sa6->sin6_addr;
292#endif
293	char tmp[64];
294
295#ifdef NI_NUMERICSCOPE
296	if (flags & NI_NUMERICSCOPE) {
297		sprintf(tmp, "%u", sa6->sin6_scope_id);
298		if (bufsiz != 0U) {
299			strncpy(buf, tmp, bufsiz - 1);
300			buf[bufsiz - 1] = '\0';
301		}
302		return(strlen(tmp));
303	}
304#endif
305
306#ifdef USE_IFNAMELINKID
307	/*
308	 * For a link-local address, convert the index to an interface
309	 * name, assuming a one-to-one mapping between links and interfaces.
310	 * Note, however, that this assumption is stronger than the
311	 * specification of the scoped address architecture;  the
312	 * specficication says that more than one interfaces can belong to
313	 * a single link.
314	 */
315
316	/* if_indextoname() does not take buffer size.  not a good api... */
317	if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
318	    bufsiz >= IF_NAMESIZE) {
319		char *p = if_indextoname(ifindex, buf);
320		if (p) {
321			return(strlen(p));
322		}
323	}
324#endif
325
326	/* last resort */
327	sprintf(tmp, "%u", sa6->sin6_scope_id);
328	if (bufsiz != 0U) {
329		strncpy(buf, tmp, bufsiz - 1);
330		buf[bufsiz - 1] = '\0';
331	}
332	return(strlen(tmp));
333}
334#endif
335
336/*! \file */
337