getnameinfo.c revision 1.11
1 /* $NetBSD: getnameinfo.c,v 1.11 2000/02/16 04:50:23 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 #ifdef INET6 80 static char *ip6_sa2str __P((struct sockaddr_in6 *, char *, int)); 81 #endif 82 83 #define ENI_NOSOCKET 0 84 #define ENI_NOSERVNAME 1 85 #define ENI_NOHOSTNAME 2 86 #define ENI_MEMORY 3 87 #define ENI_SYSTEM 4 88 #define ENI_FAMILY 5 89 #define ENI_SALEN 6 90 91 int 92 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 93 const struct sockaddr *sa; 94 size_t salen; 95 char *host; 96 size_t hostlen; 97 char *serv; 98 size_t servlen; 99 int flags; 100 { 101 struct afd *afd; 102 struct servent *sp; 103 struct hostent *hp; 104 u_short port; 105 int family, i; 106 char *addr, *p; 107 u_int32_t v4a; 108 int h_error; 109 char numserv[512]; 110 char numaddr[512]; 111 112 if (sa == NULL) 113 return ENI_NOSOCKET; 114 115 if (sa->sa_len != salen) 116 return ENI_SALEN; 117 118 family = sa->sa_family; 119 for (i = 0; afdl[i].a_af; i++) 120 if (afdl[i].a_af == family) { 121 afd = &afdl[i]; 122 goto found; 123 } 124 return ENI_FAMILY; 125 126 found: 127 if (salen != afd->a_socklen) 128 return ENI_SALEN; 129 130 port = ((struct sockinet *)sa)->si_port; /* network byte order */ 131 addr = (char *)sa + afd->a_off; 132 133 if (serv == NULL || servlen == 0) { 134 /* 135 * do nothing in this case. 136 * in case you are wondering if "&&" is more correct than 137 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 138 * means that the caller does not want the result. 139 */ 140 } else { 141 if (flags & NI_NUMERICSERV) 142 sp = NULL; 143 else { 144 sp = getservbyport(port, 145 (flags & NI_DGRAM) ? "udp" : "tcp"); 146 } 147 if (sp) { 148 if (strlen(sp->s_name) > servlen) 149 return ENI_MEMORY; 150 strcpy(serv, sp->s_name); 151 } else { 152 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 153 if (strlen(numserv) > servlen) 154 return ENI_MEMORY; 155 strcpy(serv, numserv); 156 } 157 } 158 159 switch (sa->sa_family) { 160 case AF_INET: 161 v4a = (u_int32_t) 162 ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr); 163 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 164 flags |= NI_NUMERICHOST; 165 v4a >>= IN_CLASSA_NSHIFT; 166 if (v4a == 0) 167 flags |= NI_NUMERICHOST; 168 break; 169 #ifdef INET6 170 case AF_INET6: 171 { 172 struct sockaddr_in6 *sin6; 173 sin6 = (struct sockaddr_in6 *)sa; 174 switch (sin6->sin6_addr.s6_addr[0]) { 175 case 0x00: 176 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 177 ; 178 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 179 ; 180 else 181 flags |= NI_NUMERICHOST; 182 break; 183 default: 184 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 185 flags |= NI_NUMERICHOST; 186 } 187 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 188 flags |= NI_NUMERICHOST; 189 break; 190 } 191 } 192 break; 193 #endif 194 } 195 if (host == NULL || hostlen == 0) { 196 /* 197 * do nothing in this case. 198 * in case you are wondering if "&&" is more correct than 199 * "||" here: RFC2553 says that host == NULL OR hostlen == 0 200 * means that the caller does not want the result. 201 */ 202 } else if (flags & NI_NUMERICHOST) { 203 int numaddrlen; 204 205 /* NUMERICHOST and NAMEREQD conflicts with each other */ 206 if (flags & NI_NAMEREQD) 207 return ENI_NOHOSTNAME; 208 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 209 == NULL) 210 return ENI_SYSTEM; 211 numaddrlen = strlen(numaddr); 212 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 213 return ENI_MEMORY; 214 strcpy(host, numaddr); 215 #if defined(INET6) && defined(NI_WITHSCOPEID) 216 if (afd->a_af == AF_INET6 && 217 (IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr) || 218 IN6_IS_ADDR_MULTICAST((struct in6_addr *)addr)) && 219 ((struct sockaddr_in6 *)sa)->sin6_scope_id) { 220 #ifndef ALWAYS_WITHSCOPE 221 if (flags & NI_WITHSCOPEID) 222 #endif /* !ALWAYS_WITHSCOPE */ 223 { 224 char scopebuf[MAXHOSTNAMELEN], *s; 225 int scopelen; 226 227 if ((s = ip6_sa2str((struct sockaddr_in6 *)sa, 228 scopebuf, 0)) == NULL) 229 /* XXX what should we do? */ 230 strcpy(scopebuf, "0"); 231 232 scopelen = strlen(scopebuf); 233 if (scopelen + 1 + numaddrlen + 1 > hostlen) 234 return ENI_MEMORY; 235 236 #if 1 237 /* 238 * construct <scopeid><delim><numeric-addr> 239 */ 240 /* 241 * Shift the host string to allocate 242 * space for the scope ID part. 243 */ 244 memmove(host + scopelen + 1, host, 245 numaddrlen); 246 /* copy the scope ID and the delimiter */ 247 memcpy(host, scopebuf, scopelen); 248 host[scopelen] = SCOPE_DELIMITER; 249 host[scopelen + 1 + numaddrlen] = '\0'; 250 #else 251 /* 252 * construct <numeric-addr><delim><scopeid> 253 */ 254 memcpy(host + numaddrlen + 1, scopebuf, 255 scopelen); 256 host[numaddrlen] = SCOPE_DELIMITER; 257 host[numaddrlen + 1 + scopelen] = '\0'; 258 #endif 259 } 260 } 261 #endif /* INET6 */ 262 } else { 263 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 264 h_error = h_errno; 265 266 if (hp) { 267 if (flags & NI_NOFQDN) { 268 p = strchr(hp->h_name, '.'); 269 if (p) *p = '\0'; 270 } 271 if (strlen(hp->h_name) > hostlen) { 272 return ENI_MEMORY; 273 } 274 strcpy(host, hp->h_name); 275 } else { 276 if (flags & NI_NAMEREQD) 277 return ENI_NOHOSTNAME; 278 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 279 == NULL) 280 return ENI_NOHOSTNAME; 281 if (strlen(numaddr) > hostlen) 282 return ENI_MEMORY; 283 strcpy(host, numaddr); 284 } 285 } 286 return SUCCESS; 287 } 288 289 #ifdef INET6 290 /* ARGSUSED */ 291 static char * 292 ip6_sa2str(sa6, buf, flags) 293 struct sockaddr_in6 *sa6; 294 char *buf; 295 int flags; 296 { 297 unsigned int ifindex = (unsigned int)sa6->sin6_scope_id; 298 struct in6_addr *a6 = &sa6->sin6_addr; 299 300 #ifdef notyet 301 if (flags & NI_NUMERICSCOPE) { 302 sprintf(buf, "%d", sa6->sin6_scope_id); 303 return(buf); 304 } 305 #endif 306 307 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) 308 return(if_indextoname(ifindex, buf)); 309 310 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 311 return(NULL); /* XXX */ 312 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 313 return(NULL); /* XXX */ 314 315 return(NULL); /* XXX */ 316 } 317 #endif 318
Indexes created Sun Sep 28 16:09:52 GMT 2025