getnameinfo.c revision 1.9
1 /* $NetBSD: getnameinfo.c,v 1.9 2000/01/22 23:59:46 mycroft 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 const char *addr; 103 char *p; 104 u_int32_t v4a; 105 #ifdef USE_GETIPNODEBY 106 int h_error; 107 #endif 108 char numserv[512]; 109 char numaddr[512]; 110 111 if (sa == NULL) 112 return ENI_NOSOCKET; 113 114 if (sa->sa_len != salen) 115 return ENI_SALEN; 116 117 family = sa->sa_family; 118 for (i = 0; afdl[i].a_af; i++) 119 if (afdl[i].a_af == family) { 120 afd = &afdl[i]; 121 goto found; 122 } 123 return ENI_FAMILY; 124 125 found: 126 if (salen != afd->a_socklen) 127 return ENI_SALEN; 128 129 port = ((const struct sockinet *)sa)->si_port; /* network byte order */ 130 addr = (const char *)sa + afd->a_off; 131 132 if (serv == NULL || servlen == 0) { 133 /* 134 * do nothing in this case. 135 * in case you are wondering if "&&" is more correct than 136 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 137 * means that the caller does not want the result. 138 */ 139 } else { 140 if (flags & NI_NUMERICSERV) 141 sp = NULL; 142 else { 143 sp = getservbyport(port, 144 (flags & NI_DGRAM) ? "udp" : "tcp"); 145 } 146 if (sp) { 147 if (strlen(sp->s_name) > servlen) 148 return ENI_MEMORY; 149 strcpy(serv, sp->s_name); 150 } else { 151 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 152 if (strlen(numserv) > servlen) 153 return ENI_MEMORY; 154 strcpy(serv, numserv); 155 } 156 } 157 158 switch (sa->sa_family) { 159 case AF_INET: 160 v4a = (u_int32_t) 161 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); 162 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 163 flags |= NI_NUMERICHOST; 164 v4a >>= IN_CLASSA_NSHIFT; 165 if (v4a == 0) 166 flags |= NI_NUMERICHOST; 167 break; 168 #ifdef INET6 169 case AF_INET6: 170 { 171 const struct sockaddr_in6 *sin6; 172 sin6 = (const struct sockaddr_in6 *)sa; 173 switch (sin6->sin6_addr.s6_addr[0]) { 174 case 0x00: 175 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 176 ; 177 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 178 ; 179 else 180 flags |= NI_NUMERICHOST; 181 break; 182 default: 183 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 184 flags |= NI_NUMERICHOST; 185 } 186 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 187 flags |= NI_NUMERICHOST; 188 break; 189 } 190 } 191 break; 192 #endif 193 } 194 if (host == NULL || hostlen == 0) { 195 /* 196 * do nothing in this case. 197 * in case you are wondering if "&&" is more correct than 198 * "||" here: RFC2553 says that host == NULL OR hostlen == 0 199 * means that the caller does not want the result. 200 */ 201 } else if (flags & NI_NUMERICHOST) { 202 /* NUMERICHOST and NAMEREQD conflicts with each other */ 203 if (flags & NI_NAMEREQD) 204 return ENI_NOHOSTNAME; 205 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 206 == NULL) 207 return ENI_SYSTEM; 208 if (strlen(numaddr) > hostlen) 209 return ENI_MEMORY; 210 strcpy(host, numaddr); 211 #if defined(INET6) && defined(NI_WITHSCOPEID) 212 if (afd->a_af == AF_INET6 && 213 (IN6_IS_ADDR_LINKLOCAL((const struct in6_addr *)addr) || 214 IN6_IS_ADDR_MULTICAST((const struct in6_addr *)addr)) && 215 ((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 216 #ifndef ALWAYS_WITHSCOPE 217 if (flags & NI_WITHSCOPEID) 218 #endif /* !ALWAYS_WITHSCOPE */ 219 { 220 char *ep = strchr(host, '\0'); 221 unsigned int ifindex = 222 ((const struct sockaddr_in6 *)sa)->sin6_scope_id; 223 224 *ep = SCOPE_DELIMITER; 225 if ((if_indextoname(ifindex, ep + 1)) == NULL) 226 /* XXX what should we do? */ 227 strncpy(ep + 1, "???", 3); 228 } 229 } 230 #endif /* INET6 */ 231 } else { 232 #ifdef USE_GETIPNODEBY 233 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 234 #else 235 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 236 #endif 237 238 if (hp) { 239 if (flags & NI_NOFQDN) { 240 p = strchr(hp->h_name, '.'); 241 if (p) *p = '\0'; 242 } 243 if (strlen(hp->h_name) > hostlen) { 244 #ifdef USE_GETIPNODEBY 245 freehostent(hp); 246 #endif 247 return ENI_MEMORY; 248 } 249 strcpy(host, hp->h_name); 250 #ifdef USE_GETIPNODEBY 251 freehostent(hp); 252 #endif 253 } else { 254 if (flags & NI_NAMEREQD) 255 return ENI_NOHOSTNAME; 256 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 257 == NULL) 258 return ENI_NOHOSTNAME; 259 if (strlen(numaddr) > hostlen) 260 return ENI_MEMORY; 261 strcpy(host, numaddr); 262 } 263 } 264 return SUCCESS; 265 } 266
Indexes created Tue Sep 30 11:09:46 GMT 2025