getnameinfo.c revision 1.15
1 /* $NetBSD: getnameinfo.c,v 1.15 2000/04/24 10:40:25 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/cdefs.h> 43 #if defined(LIBC_SCCS) && !defined(lint) 44 __RCSID("$NetBSD: getnameinfo.c,v 1.15 2000/04/24 10:40:25 itojun Exp $"); 45 #endif /* LIBC_SCCS and not lint */ 46 47 #include "namespace.h" 48 #include <sys/types.h> 49 #include <sys/socket.h> 50 #include <net/if.h> 51 #include <netinet/in.h> 52 #include <arpa/inet.h> 53 #include <arpa/nameser.h> 54 #include <netdb.h> 55 #include <resolv.h> 56 #include <string.h> 57 #include <stddef.h> 58 59 #ifdef __weak_alias 60 __weak_alias(getnameinfo,_getnameinfo) 61 #endif 62 63 #define SUCCESS 0 64 #define ANY 0 65 #define YES 1 66 #define NO 0 67 68 static struct afd { 69 int a_af; 70 int a_addrlen; 71 int a_socklen; 72 int a_off; 73 } afdl [] = { 74 #ifdef INET6 75 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 76 offsetof(struct sockaddr_in6, sin6_addr)}, 77 #endif 78 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 79 offsetof(struct sockaddr_in, sin_addr)}, 80 {0, 0, 0}, 81 }; 82 83 struct sockinet { 84 u_char si_len; 85 u_char si_family; 86 u_short si_port; 87 }; 88 89 #ifdef INET6 90 static char *ip6_sa2str __P((struct sockaddr_in6 *, char *, int)); 91 #endif 92 93 #define ENI_NOSOCKET 0 94 #define ENI_NOSERVNAME 1 95 #define ENI_NOHOSTNAME 2 96 #define ENI_MEMORY 3 97 #define ENI_SYSTEM 4 98 #define ENI_FAMILY 5 99 #define ENI_SALEN 6 100 101 int 102 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 103 const struct sockaddr *sa; 104 size_t salen; 105 char *host; 106 size_t hostlen; 107 char *serv; 108 size_t servlen; 109 int flags; 110 { 111 struct afd *afd; 112 struct servent *sp; 113 struct hostent *hp; 114 u_short port; 115 int family, i; 116 char *addr, *p; 117 u_int32_t v4a; 118 int h_error; 119 char numserv[512]; 120 char numaddr[512]; 121 122 if (sa == NULL) 123 return ENI_NOSOCKET; 124 125 #ifdef BSD4_4 126 if (sa->sa_len != salen) 127 return ENI_SALEN; 128 #endif 129 130 family = sa->sa_family; 131 for (i = 0; afdl[i].a_af; i++) 132 if (afdl[i].a_af == family) { 133 afd = &afdl[i]; 134 goto found; 135 } 136 return ENI_FAMILY; 137 138 found: 139 if (salen != afd->a_socklen) 140 return ENI_SALEN; 141 142 port = ((struct sockinet *)sa)->si_port; /* network byte order */ 143 addr = (char *)sa + afd->a_off; 144 145 if (serv == NULL || servlen == 0) { 146 /* 147 * do nothing in this case. 148 * in case you are wondering if "&&" is more correct than 149 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 150 * means that the caller does not want the result. 151 */ 152 } else { 153 if (flags & NI_NUMERICSERV) 154 sp = NULL; 155 else { 156 sp = getservbyport(port, 157 (flags & NI_DGRAM) ? "udp" : "tcp"); 158 } 159 if (sp) { 160 if (strlen(sp->s_name) > servlen) 161 return ENI_MEMORY; 162 strcpy(serv, sp->s_name); 163 } else { 164 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 165 if (strlen(numserv) > servlen) 166 return ENI_MEMORY; 167 strcpy(serv, numserv); 168 } 169 } 170 171 switch (sa->sa_family) { 172 case AF_INET: 173 v4a = (u_int32_t) 174 ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr); 175 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 176 flags |= NI_NUMERICHOST; 177 v4a >>= IN_CLASSA_NSHIFT; 178 if (v4a == 0) 179 flags |= NI_NUMERICHOST; 180 break; 181 #ifdef INET6 182 case AF_INET6: 183 { 184 struct sockaddr_in6 *sin6; 185 sin6 = (struct sockaddr_in6 *)sa; 186 switch (sin6->sin6_addr.s6_addr[0]) { 187 case 0x00: 188 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 189 ; 190 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 191 ; 192 else 193 flags |= NI_NUMERICHOST; 194 break; 195 default: 196 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 197 flags |= NI_NUMERICHOST; 198 } 199 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 200 flags |= NI_NUMERICHOST; 201 break; 202 } 203 } 204 break; 205 #endif 206 } 207 if (host == NULL || hostlen == 0) { 208 /* 209 * do nothing in this case. 210 * in case you are wondering if "&&" is more correct than 211 * "||" here: RFC2553 says that host == NULL OR hostlen == 0 212 * means that the caller does not want the result. 213 */ 214 } else if (flags & NI_NUMERICHOST) { 215 int numaddrlen; 216 217 /* NUMERICHOST and NAMEREQD conflicts with each other */ 218 if (flags & NI_NAMEREQD) 219 return ENI_NOHOSTNAME; 220 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 221 == NULL) 222 return ENI_SYSTEM; 223 numaddrlen = strlen(numaddr); 224 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 225 return ENI_MEMORY; 226 strcpy(host, numaddr); 227 #if defined(INET6) && defined(NI_WITHSCOPEID) 228 if (afd->a_af == AF_INET6 && 229 (IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr) || 230 IN6_IS_ADDR_MULTICAST((struct in6_addr *)addr)) && 231 ((struct sockaddr_in6 *)sa)->sin6_scope_id) { 232 #ifndef ALWAYS_WITHSCOPE 233 if (flags & NI_WITHSCOPEID) 234 #endif /* !ALWAYS_WITHSCOPE */ 235 { 236 char scopebuf[MAXHOSTNAMELEN], *s; 237 int scopelen; 238 239 if ((s = ip6_sa2str((struct sockaddr_in6 *)sa, 240 scopebuf, 0)) == NULL) 241 /* XXX what should we do? */ 242 strcpy(scopebuf, "0"); 243 244 scopelen = strlen(scopebuf); 245 if (scopelen + 1 + numaddrlen + 1 > hostlen) 246 return ENI_MEMORY; 247 248 #if 0 249 /* 250 * construct <scopeid><delim><numeric-addr> 251 */ 252 /* 253 * Shift the host string to allocate 254 * space for the scope ID part. 255 */ 256 memmove(host + scopelen + 1, host, 257 numaddrlen); 258 /* copy the scope ID and the delimiter */ 259 memcpy(host, scopebuf, scopelen); 260 host[scopelen] = SCOPE_DELIMITER; 261 host[scopelen + 1 + numaddrlen] = '\0'; 262 #else 263 /* 264 * construct <numeric-addr><delim><scopeid> 265 */ 266 memcpy(host + numaddrlen + 1, scopebuf, 267 scopelen); 268 host[numaddrlen] = SCOPE_DELIMITER; 269 host[numaddrlen + 1 + scopelen] = '\0'; 270 #endif 271 } 272 } 273 #endif /* INET6 */ 274 } else { 275 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 276 h_error = h_errno; 277 278 if (hp) { 279 if (flags & NI_NOFQDN) { 280 p = strchr(hp->h_name, '.'); 281 if (p) *p = '\0'; 282 } 283 if (strlen(hp->h_name) > hostlen) { 284 return ENI_MEMORY; 285 } 286 strcpy(host, hp->h_name); 287 } else { 288 if (flags & NI_NAMEREQD) 289 return ENI_NOHOSTNAME; 290 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 291 == NULL) 292 return ENI_NOHOSTNAME; 293 if (strlen(numaddr) > hostlen) 294 return ENI_MEMORY; 295 strcpy(host, numaddr); 296 } 297 } 298 return SUCCESS; 299 } 300 301 #ifdef INET6 302 /* ARGSUSED */ 303 static char * 304 ip6_sa2str(sa6, buf, flags) 305 struct sockaddr_in6 *sa6; 306 char *buf; 307 int flags; 308 { 309 unsigned int ifindex = (unsigned int)sa6->sin6_scope_id; 310 struct in6_addr *a6 = &sa6->sin6_addr; 311 312 #ifdef notyet 313 if (flags & NI_NUMERICSCOPE) { 314 sprintf(buf, "%d", sa6->sin6_scope_id); 315 return(buf); 316 } 317 #endif 318 319 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) 320 return(if_indextoname(ifindex, buf)); 321 322 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 323 return(NULL); /* XXX */ 324 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 325 return(NULL); /* XXX */ 326 327 return(NULL); /* XXX */ 328 } 329 #endif 330
Indexes created Mon Sep 29 21:09:56 GMT 2025