getnameinfo.c revision 1.8
1 /* $NetBSD: getnameinfo.c,v 1.8 2000/01/17 08:34:05 itojun 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 * - RFC2553 says that we should raise error on short buffer. X/Open says 38 * we need to truncate the result. We obey RFC2553 (and X/Open should be 39 * modified). 40 */ 41 42 #include <sys/types.h> 43 #include <sys/socket.h> 44 #include <net/if.h> 45 #include <netinet/in.h> 46 #include <arpa/inet.h> 47 #include <arpa/nameser.h> 48 #include <netdb.h> 49 #include <resolv.h> 50 #include <string.h> 51 #include <stddef.h> 52 53 #define SUCCESS 0 54 #define ANY 0 55 #define YES 1 56 #define NO 0 57 58 static struct afd { 59 int a_af; 60 int a_addrlen; 61 int a_socklen; 62 int a_off; 63 } afdl [] = { 64 #ifdef INET6 65 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 66 offsetof(struct sockaddr_in6, sin6_addr)}, 67 #endif 68 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 69 offsetof(struct sockaddr_in, sin_addr)}, 70 {0, 0, 0}, 71 }; 72 73 struct sockinet { 74 u_char si_len; 75 u_char si_family; 76 u_short si_port; 77 }; 78 79 #define ENI_NOSOCKET 0 80 #define ENI_NOSERVNAME 1 81 #define ENI_NOHOSTNAME 2 82 #define ENI_MEMORY 3 83 #define ENI_SYSTEM 4 84 #define ENI_FAMILY 5 85 #define ENI_SALEN 6 86 87 int 88 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 89 const struct sockaddr *sa; 90 size_t salen; 91 char *host; 92 size_t hostlen; 93 char *serv; 94 size_t servlen; 95 int flags; 96 { 97 struct afd *afd; 98 struct servent *sp; 99 struct hostent *hp; 100 u_short port; 101 int family, i; 102 char *addr, *p; 103 u_int32_t v4a; 104 int h_error; 105 char numserv[512]; 106 char numaddr[512]; 107 108 if (sa == NULL) 109 return ENI_NOSOCKET; 110 111 if (sa->sa_len != salen) 112 return ENI_SALEN; 113 114 family = sa->sa_family; 115 for (i = 0; afdl[i].a_af; i++) 116 if (afdl[i].a_af == family) { 117 afd = &afdl[i]; 118 goto found; 119 } 120 return ENI_FAMILY; 121 122 found: 123 if (salen != afd->a_socklen) 124 return ENI_SALEN; 125 126 port = ((struct sockinet *)sa)->si_port; /* network byte order */ 127 addr = (char *)sa + afd->a_off; 128 129 if (serv == NULL || servlen == 0) { 130 /* 131 * do nothing in this case. 132 * in case you are wondering if "&&" is more correct than 133 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 134 * means that the caller does not want the result. 135 */ 136 } else { 137 if (flags & NI_NUMERICSERV) 138 sp = NULL; 139 else { 140 sp = getservbyport(port, 141 (flags & NI_DGRAM) ? "udp" : "tcp"); 142 } 143 if (sp) { 144 if (strlen(sp->s_name) > servlen) 145 return ENI_MEMORY; 146 strcpy(serv, sp->s_name); 147 } else { 148 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 149 if (strlen(numserv) > servlen) 150 return ENI_MEMORY; 151 strcpy(serv, numserv); 152 } 153 } 154 155 switch (sa->sa_family) { 156 case AF_INET: 157 v4a = (u_int32_t) 158 ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr); 159 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 160 flags |= NI_NUMERICHOST; 161 v4a >>= IN_CLASSA_NSHIFT; 162 if (v4a == 0) 163 flags |= NI_NUMERICHOST; 164 break; 165 #ifdef INET6 166 case AF_INET6: 167 { 168 struct sockaddr_in6 *sin6; 169 sin6 = (struct sockaddr_in6 *)sa; 170 switch (sin6->sin6_addr.s6_addr[0]) { 171 case 0x00: 172 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 173 ; 174 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 175 ; 176 else 177 flags |= NI_NUMERICHOST; 178 break; 179 default: 180 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 181 flags |= NI_NUMERICHOST; 182 } 183 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 184 flags |= NI_NUMERICHOST; 185 break; 186 } 187 } 188 break; 189 #endif 190 } 191 if (host == NULL || hostlen == 0) { 192 /* 193 * do nothing in this case. 194 * in case you are wondering if "&&" is more correct than 195 * "||" here: RFC2553 says that host == NULL OR hostlen == 0 196 * means that the caller does not want the result. 197 */ 198 } else if (flags & NI_NUMERICHOST) { 199 /* NUMERICHOST and NAMEREQD conflicts with each other */ 200 if (flags & NI_NAMEREQD) 201 return ENI_NOHOSTNAME; 202 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 203 == NULL) 204 return ENI_SYSTEM; 205 if (strlen(numaddr) > hostlen) 206 return ENI_MEMORY; 207 strcpy(host, numaddr); 208 #if defined(INET6) && defined(NI_WITHSCOPEID) 209 if (afd->a_af == AF_INET6 && 210 (IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr) || 211 IN6_IS_ADDR_MULTICAST((struct in6_addr *)addr)) && 212 ((struct sockaddr_in6 *)sa)->sin6_scope_id) { 213 #ifndef ALWAYS_WITHSCOPE 214 if (flags & NI_WITHSCOPEID) 215 #endif /* !ALWAYS_WITHSCOPE */ 216 { 217 char *ep = strchr(host, '\0'); 218 unsigned int ifindex = 219 ((struct sockaddr_in6 *)sa)->sin6_scope_id; 220 221 *ep = SCOPE_DELIMITER; 222 if ((if_indextoname(ifindex, ep + 1)) == NULL) 223 /* XXX what should we do? */ 224 strncpy(ep + 1, "???", 3); 225 } 226 } 227 #endif /* INET6 */ 228 } else { 229 #ifdef USE_GETIPNODEBY 230 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 231 #else 232 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 233 h_error = h_errno; 234 #endif 235 236 if (hp) { 237 if (flags & NI_NOFQDN) { 238 p = strchr(hp->h_name, '.'); 239 if (p) *p = '\0'; 240 } 241 if (strlen(hp->h_name) > hostlen) { 242 #ifdef USE_GETIPNODEBY 243 freehostent(hp); 244 #endif 245 return ENI_MEMORY; 246 } 247 strcpy(host, hp->h_name); 248 #ifdef USE_GETIPNODEBY 249 freehostent(hp); 250 #endif 251 } else { 252 if (flags & NI_NAMEREQD) 253 return ENI_NOHOSTNAME; 254 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 255 == NULL) 256 return ENI_NOHOSTNAME; 257 if (strlen(numaddr) > hostlen) 258 return ENI_MEMORY; 259 strcpy(host, numaddr); 260 } 261 } 262 return SUCCESS; 263 } 264
Indexes created Tue Sep 30 11:09:46 GMT 2025