1 /* $NetBSD: getnameinfo.c,v 1.3 2014/12/10 04:37:56 christos Exp $ */
2
3 /*
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 /*
33 * Issues to be discussed:
34 * - Thread safe-ness must be checked
35 * - Return values. There seems to be no standard for return value (RFC2553)
36 * but INRIA implementation returns EAI_xxx defined for getaddrinfo().
37 */
38
39 #include <sys/types.h>
40 #include <sys/socket.h>
41 #include <netinet/in.h>
42 #include <arpa/inet.h>
43 #include <arpa/nameser.h>
44 #include <netdb.h>
45 #include <resolv.h>
46 #include <string.h>
47 #include <stddef.h>
48
49 #include "addrinfo.h"
50
51 #define SUCCESS 0
52 #define ANY 0
53 #define YES 1
54 #define NO 0
55
56 static struct afd {
57 int a_af;
58 int a_addrlen;
59 int a_socklen;
60 int a_off;
61 } afdl [] = {
62 #ifdef INET6
63 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
64 offsetof(struct sockaddr_in6, sin6_addr)},
65 #endif
66 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
67 offsetof(struct sockaddr_in, sin_addr)},
68 {0, 0, 0},
69 };
70
71 struct sockinet {
72 u_char si_len;
73 u_char si_family;
74 u_short si_port;
75 };
76
77 #define ENI_NOSOCKET 0
78 #define ENI_NOSERVNAME 1
79 #define ENI_NOHOSTNAME 2
80 #define ENI_MEMORY 3
81 #define ENI_SYSTEM 4
82 #define ENI_FAMILY 5
83 #define ENI_SALEN 6
84
85 int
getnameinfo(sa,salen,host,hostlen,serv,servlen,flags)86 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
87 const struct sockaddr *sa;
88 size_t salen;
89 char *host;
90 size_t hostlen;
91 char *serv;
92 size_t servlen;
93 int flags;
94 {
95 struct afd *afd;
96 struct servent *sp;
97 struct hostent *hp;
98 u_short port;
99 int family, len, i;
100 char *addr, *p;
101 u_long v4a;
102 int h_error;
103 char numserv[512];
104 char numaddr[512];
105
106 if (sa == NULL)
107 return ENI_NOSOCKET;
108
109 #ifdef HAVE_SA_LEN
110 len = sa->sa_len;
111 if (len != salen) return ENI_SALEN;
112 #else
113 len = salen;
114 #endif
115
116 family = sa->sa_family;
117 for (i = 0; afdl[i].a_af; i++)
118 if (afdl[i].a_af == family) {
119 afd = &afdl[i];
120 goto found;
121 }
122 return ENI_FAMILY;
123
124 found:
125 if (len != afd->a_socklen) return ENI_SALEN;
126
127 port = ((struct sockinet *)sa)->si_port; /* network byte order */
128 addr = (char *)sa + afd->a_off;
129
130 if (serv == NULL || servlen == 0) {
131 /* what we should do? */
132 } else if (flags & NI_NUMERICSERV) {
133 snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
134 if (strlen(numserv) > servlen)
135 return ENI_MEMORY;
136 strcpy(serv, numserv);
137 } else {
138 sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp");
139 if (sp) {
140 if (strlen(sp->s_name) > servlen)
141 return ENI_MEMORY;
142 strcpy(serv, sp->s_name);
143 } else
144 return ENI_NOSERVNAME;
145 }
146
147 switch (sa->sa_family) {
148 case AF_INET:
149 v4a = ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr);
150 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a))
151 flags |= NI_NUMERICHOST;
152 v4a >>= IN_CLASSA_NSHIFT;
153 if (v4a == 0 || v4a == IN_LOOPBACKNET)
154 flags |= NI_NUMERICHOST;
155 break;
156 #ifdef INET6
157 case AF_INET6:
158 {
159 struct sockaddr_in6 *sin6;
160 sin6 = (struct sockaddr_in6 *)sa;
161 switch (sin6->sin6_addr.s6_addr[0]) {
162 case 0x00:
163 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
164 ;
165 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
166 ;
167 else
168 flags |= NI_NUMERICHOST;
169 break;
170 default:
171 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
172 flags |= NI_NUMERICHOST;
173 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
174 flags |= NI_NUMERICHOST;
175 break;
176 }
177 }
178 break;
179 #endif
180 }
181 if (host == NULL || hostlen == 0) {
182 /* what should we do? */
183 } else if (flags & NI_NUMERICHOST) {
184 /* NUMERICHOST and NAMEREQD conflicts with each other */
185 if (flags & NI_NAMEREQD)
186 return ENI_NOHOSTNAME;
187 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
188 == NULL)
189 return ENI_SYSTEM;
190 if (strlen(numaddr) > hostlen)
191 return ENI_MEMORY;
192 strcpy(host, numaddr);
193 } else {
194 #ifdef USE_GETIPNODEBY
195 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
196 #else
197 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
198 h_error = h_errno;
199 #endif
200
201 if (hp) {
202 if (flags & NI_NOFQDN) {
203 p = strchr(hp->h_name, '.');
204 if (p) *p = '\0';
205 }
206 if (strlen(hp->h_name) > hostlen) {
207 #ifdef USE_GETIPNODEBY
208 freehostent(hp);
209 #endif
210 return ENI_MEMORY;
211 }
212 strcpy(host, hp->h_name);
213 #ifdef USE_GETIPNODEBY
214 freehostent(hp);
215 #endif
216 } else {
217 if (flags & NI_NAMEREQD)
218 return ENI_NOHOSTNAME;
219 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
220 == NULL)
221 return ENI_NOHOSTNAME;
222 if (strlen(numaddr) > hostlen)
223 return ENI_MEMORY;
224 strcpy(host, numaddr);
225 }
226 }
227 return SUCCESS;
228 }
229