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