1 /* $NetBSD: getnameinfo.c,v 1.6 2007/07/22 05:19:01 lukem Exp $ */
2 /* from ? */
3
4 /*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
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.
19 *
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
30 * SUCH DAMAGE.
31 */
32
33 /*
34 * Issues to be discussed:
35 * - Thread safe-ness must be checked
36 * - Return values. There seems to be no standard for return value (RFC2553)
37 * but INRIA implementation returns EAI_xxx defined for getaddrinfo().
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).
41 * - What is "local" in NI_FQDN?
42 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other.
43 * - (KAME extension) NI_WITHSCOPEID when called with global address,
44 * and sin6_scope_id filled
45 */
46
47 #include "tnftp.h"
48
49 #define SUCCESS 0
50 #define ANY 0
51 #define YES 1
52 #define NO 0
53
54 static struct afd {
55 int a_af;
56 int a_addrlen;
57 int a_socklen;
58 int a_off;
59 } afdl [] = {
60 #ifdef INET6
61 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
62 offsetof(struct sockaddr_in6, sin6_addr)},
63 #endif
64 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
65 offsetof(struct sockaddr_in, sin_addr)},
66 {0, 0, 0},
67 };
68
69 struct sockinet {
70 unsigned char si_len;
71 unsigned char si_family;
72 unsigned short si_port;
73 };
74
75 #ifdef INET6
76 static int ip6_parsenumeric(const struct sockaddr *, const char *, char *,
77 size_t, int);
78 static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int);
79 #endif
80
81 #define ENI_NOSOCKET EAI_FAIL /*XXX*/
82 #define ENI_NOSERVNAME EAI_NONAME
83 #define ENI_NOHOSTNAME EAI_NONAME
84 #define ENI_MEMORY EAI_MEMORY
85 #define ENI_SYSTEM EAI_SYSTEM
86 #define ENI_FAMILY EAI_FAMILY
87 #define ENI_SALEN EAI_FAMILY
88
89 int
getnameinfo(const struct sockaddr * sa,socklen_t salen,char * host,size_t hostlen,char * serv,size_t servlen,int flags)90 getnameinfo(const struct sockaddr *sa, socklen_t salen,
91 char *host, size_t hostlen, char *serv, size_t servlen, int flags)
92 {
93 struct afd *afd;
94 struct servent *sp;
95 struct hostent *hp;
96 unsigned short port;
97 int family, i;
98 const char *addr;
99 unsigned int v4a;
100 char numserv[512];
101 char numaddr[512];
102
103 if (sa == NULL)
104 return ENI_NOSOCKET;
105
106 #if defined(HAVE_STRUCT_SOCKADDR_SA_LEN)
107 if (sa->sa_len != salen)
108 return ENI_SALEN;
109 #endif
110
111 family = sa->sa_family;
112 for (i = 0; afdl[i].a_af; i++)
113 if (afdl[i].a_af == family) {
114 afd = &afdl[i];
115 goto found;
116 }
117 return ENI_FAMILY;
118
119 found:
120 if (salen != afd->a_socklen)
121 return ENI_SALEN;
122
123 /* network byte order */
124 port = ((const struct sockinet *)sa)->si_port;
125 addr = (const char *)sa + afd->a_off;
126
127 if (serv == NULL || servlen == 0) {
128 /*
129 * do nothing in this case.
130 * in case you are wondering if "&&" is more correct than
131 * "||" here: RFC2553 says that serv == NULL OR servlen == 0
132 * means that the caller does not want the result.
133 */
134 } else {
135 if (flags & NI_NUMERICSERV)
136 sp = NULL;
137 else {
138 sp = getservbyport(port,
139 (flags & NI_DGRAM) ? "udp" : "tcp");
140 }
141 if (sp) {
142 if (strlen(sp->s_name) > servlen)
143 return ENI_MEMORY;
144 strcpy(serv, sp->s_name);
145 } else {
146 snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
147 if (strlen(numserv) > servlen)
148 return ENI_MEMORY;
149 strcpy(serv, numserv);
150 }
151 }
152
153 switch (sa->sa_family) {
154 case AF_INET:
155 v4a = (unsigned int)
156 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr);
157 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
158 flags |= NI_NUMERICHOST;
159 v4a >>= IN_CLASSA_NSHIFT;
160 if (v4a == 0)
161 flags |= NI_NUMERICHOST;
162 break;
163 #ifdef INET6
164 case AF_INET6:
165 {
166 const struct sockaddr_in6 *sin6;
167 sin6 = (const struct sockaddr_in6 *)sa;
168 switch (sin6->sin6_addr.s6_addr[0]) {
169 case 0x00:
170 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
171 ;
172 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
173 ;
174 else
175 flags |= NI_NUMERICHOST;
176 break;
177 default:
178 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
179 flags |= NI_NUMERICHOST;
180 }
181 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
182 flags |= NI_NUMERICHOST;
183 break;
184 }
185 }
186 break;
187 #endif
188 }
189 if (host == NULL || hostlen == 0) {
190 /*
191 * do nothing in this case.
192 * in case you are wondering if "&&" is more correct than
193 * "||" here: RFC2553 says that host == NULL OR hostlen == 0
194 * means that the caller does not want the result.
195 */
196 } else if (flags & NI_NUMERICHOST) {
197 int numaddrlen;
198
199 /* NUMERICHOST and NAMEREQD conflicts with each other */
200 if (flags & NI_NAMEREQD)
201 return ENI_NOHOSTNAME;
202
203 switch(afd->a_af) {
204 #ifdef INET6
205 case AF_INET6:
206 {
207 int error;
208
209 if ((error = ip6_parsenumeric(sa, addr, host,
210 hostlen, flags)) != 0)
211 return(error);
212 break;
213 }
214 #endif
215 default:
216 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
217 == NULL)
218 return ENI_SYSTEM;
219 numaddrlen = strlen(numaddr);
220 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
221 return ENI_MEMORY;
222 strcpy(host, numaddr);
223 break;
224 }
225 } else {
226 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
227
228 if (hp) {
229 #if 0
230 /*
231 * commented out, since "for local host" is not
232 * implemented here - see RFC2553 p30
233 */
234 if (flags & NI_NOFQDN) {
235 char *p;
236 p = strchr(hp->h_name, '.');
237 if (p)
238 *p = '\0';
239 }
240 #endif
241 if (strlen(hp->h_name) > hostlen) {
242 return ENI_MEMORY;
243 }
244 strcpy(host, hp->h_name);
245 } else {
246 if (flags & NI_NAMEREQD)
247 return ENI_NOHOSTNAME;
248 switch(afd->a_af) {
249 #ifdef INET6
250 case AF_INET6:
251 {
252 int error;
253
254 if ((error = ip6_parsenumeric(sa, addr, host,
255 hostlen,
256 flags)) != 0)
257 return(error);
258 break;
259 }
260 #endif
261 default:
262 if (inet_ntop(afd->a_af, addr, host,
263 hostlen) == NULL)
264 return ENI_SYSTEM;
265 break;
266 }
267 }
268 }
269 return SUCCESS;
270 }
271
272 #ifdef INET6
273 static int
ip6_parsenumeric(const struct sockaddr * sa,const char * addr,char * host,size_t hostlen,int flags)274 ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host,
275 size_t hostlen, int flags)
276 {
277 int numaddrlen;
278 char numaddr[512];
279
280 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr))
281 == NULL)
282 return ENI_SYSTEM;
283
284 numaddrlen = strlen(numaddr);
285 if (numaddrlen + 1 > hostlen) /* don't forget terminator */
286 return ENI_MEMORY;
287 strcpy(host, numaddr);
288
289 #ifdef NI_WITHSCOPEID
290 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) {
291 if (flags & NI_WITHSCOPEID)
292 {
293 char scopebuf[MAXHOSTNAMELEN];
294 int scopelen;
295
296 /* ip6_sa2str never fails */
297 scopelen = ip6_sa2str((const struct sockaddr_in6 *)sa,
298 scopebuf, sizeof(scopebuf),
299 0);
300 if (scopelen + 1 + numaddrlen + 1 > hostlen)
301 return ENI_MEMORY;
302 /*
303 * construct <numeric-addr><delim><scopeid>
304 */
305 memcpy(host + numaddrlen + 1, scopebuf,
306 scopelen);
307 host[numaddrlen] = SCOPE_DELIMITER;
308 host[numaddrlen + 1 + scopelen] = '\0';
309 }
310 }
311 #endif /* NI_WITHSCOPEID */
312
313 return 0;
314 }
315
316 /* ARGSUSED */
317 static int
ip6_sa2str(const struct sockaddr_in6 * sa6,char * buf,size_t bufsiz,int flags)318 ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags)
319 {
320 unsigned int ifindex = (unsigned int)sa6->sin6_scope_id;
321 const struct in6_addr *a6 = &sa6->sin6_addr;
322
323 #ifdef notyet
324 if (flags & NI_NUMERICSCOPE) {
325 return(snprintf(buf, bufsiz, "%d", sa6->sin6_scope_id));
326 }
327 #endif
328
329 /*
330 * XXXLUKEM: some systems (MacOS X) don't have IF_NAMESIZE
331 * or if_indextoname()
332 */
333 #if 0
334 /* if_indextoname() does not take buffer size. not a good api... */
335 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
336 bufsiz >= IF_NAMESIZE) {
337 char *p = if_indextoname(ifindex, buf);
338 if (p) {
339 return(strlen(p));
340 }
341 }
342 #endif
343
344 /* last resort */
345 return(snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id));
346 }
347 #endif /* INET6 */
348