getnameinfo.c revision 1.16
1 /* $NetBSD: getnameinfo.c,v 1.16 2000/04/26 16:08:38 itojun Exp $ */ 2 /* $KAME: getnameinfo.c,v 1.38 2000/04/26 15:58:50 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * Issues to be discussed: 35 * - Thread safe-ness must be checked 36 * - Return values. There seems to be no standard for return value (RFC2553) 37 * but INRIA implementation returns EAI_xxx defined for getaddrinfo(). 38 * - RFC2553 says that we should raise error on short buffer. X/Open says 39 * we need to truncate the result. We obey RFC2553 (and X/Open should be 40 * modified). 41 * - What is "local" in NI_FQDN? 42 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other. 43 * - (KAME extension) NI_WITHSCOPEID when called with global address, 44 * and sin6_scope_id filled 45 */ 46 47 #include <sys/cdefs.h> 48 #if defined(LIBC_SCCS) && !defined(lint) 49 __RCSID("$NetBSD: getnameinfo.c,v 1.16 2000/04/26 16:08:38 itojun Exp $"); 50 #endif /* LIBC_SCCS and not lint */ 51 52 #include "namespace.h" 53 #include <sys/types.h> 54 #include <sys/socket.h> 55 #include <net/if.h> 56 #include <netinet/in.h> 57 #include <arpa/inet.h> 58 #include <arpa/nameser.h> 59 #include <netdb.h> 60 #include <resolv.h> 61 #include <string.h> 62 #include <stddef.h> 63 64 #ifdef __weak_alias 65 __weak_alias(getnameinfo,_getnameinfo) 66 #endif 67 68 #define SUCCESS 0 69 #define ANY 0 70 #define YES 1 71 #define NO 0 72 73 static struct afd { 74 int a_af; 75 int a_addrlen; 76 int a_socklen; 77 int a_off; 78 } afdl [] = { 79 #ifdef INET6 80 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 81 offsetof(struct sockaddr_in6, sin6_addr)}, 82 #endif 83 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 84 offsetof(struct sockaddr_in, sin_addr)}, 85 {0, 0, 0}, 86 }; 87 88 struct sockinet { 89 u_char si_len; 90 u_char si_family; 91 u_short si_port; 92 }; 93 94 #ifdef INET6 95 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *, 96 size_t, int)); 97 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int)); 98 #endif 99 100 #define ENI_NOSOCKET 0 101 #define ENI_NOSERVNAME 1 102 #define ENI_NOHOSTNAME 2 103 #define ENI_MEMORY 3 104 #define ENI_SYSTEM 4 105 #define ENI_FAMILY 5 106 #define ENI_SALEN 6 107 108 int 109 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 110 const struct sockaddr *sa; 111 size_t salen; 112 char *host; 113 size_t hostlen; 114 char *serv; 115 size_t servlen; 116 int flags; 117 { 118 struct afd *afd; 119 struct servent *sp; 120 struct hostent *hp; 121 u_short port; 122 int family, i; 123 const char *addr; 124 u_int32_t v4a; 125 int h_error; 126 char numserv[512]; 127 char numaddr[512]; 128 129 if (sa == NULL) 130 return ENI_NOSOCKET; 131 132 #ifdef BSD4_4 133 if (sa->sa_len != salen) 134 return ENI_SALEN; 135 #endif 136 137 family = sa->sa_family; 138 for (i = 0; afdl[i].a_af; i++) 139 if (afdl[i].a_af == family) { 140 afd = &afdl[i]; 141 goto found; 142 } 143 return ENI_FAMILY; 144 145 found: 146 if (salen != afd->a_socklen) 147 return ENI_SALEN; 148 149 /* network byte order */ 150 port = ((const struct sockinet *)sa)->si_port; 151 addr = (const char *)sa + afd->a_off; 152 153 if (serv == NULL || servlen == 0) { 154 /* 155 * do nothing in this case. 156 * in case you are wondering if "&&" is more correct than 157 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 158 * means that the caller does not want the result. 159 */ 160 } else { 161 if (flags & NI_NUMERICSERV) 162 sp = NULL; 163 else { 164 sp = getservbyport(port, 165 (flags & NI_DGRAM) ? "udp" : "tcp"); 166 } 167 if (sp) { 168 if (strlen(sp->s_name) > servlen) 169 return ENI_MEMORY; 170 strcpy(serv, sp->s_name); 171 } else { 172 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 173 if (strlen(numserv) > servlen) 174 return ENI_MEMORY; 175 strcpy(serv, numserv); 176 } 177 } 178 179 switch (sa->sa_family) { 180 case AF_INET: 181 v4a = (u_int32_t) 182 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); 183 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 184 flags |= NI_NUMERICHOST; 185 v4a >>= IN_CLASSA_NSHIFT; 186 if (v4a == 0) 187 flags |= NI_NUMERICHOST; 188 break; 189 #ifdef INET6 190 case AF_INET6: 191 { 192 const struct sockaddr_in6 *sin6; 193 sin6 = (const struct sockaddr_in6 *)sa; 194 switch (sin6->sin6_addr.s6_addr[0]) { 195 case 0x00: 196 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 197 ; 198 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 199 ; 200 else 201 flags |= NI_NUMERICHOST; 202 break; 203 default: 204 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 205 flags |= NI_NUMERICHOST; 206 } 207 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 208 flags |= NI_NUMERICHOST; 209 break; 210 } 211 } 212 break; 213 #endif 214 } 215 if (host == NULL || hostlen == 0) { 216 /* 217 * do nothing in this case. 218 * in case you are wondering if "&&" is more correct than 219 * "||" here: RFC2553 says that host == NULL OR hostlen == 0 220 * means that the caller does not want the result. 221 */ 222 } else if (flags & NI_NUMERICHOST) { 223 int numaddrlen; 224 225 /* NUMERICHOST and NAMEREQD conflicts with each other */ 226 if (flags & NI_NAMEREQD) 227 return ENI_NOHOSTNAME; 228 229 switch(afd->a_af) { 230 #ifdef INET6 231 case AF_INET6: 232 { 233 int error; 234 235 if ((error = ip6_parsenumeric(sa, addr, host, 236 hostlen, flags)) != 0) 237 return(error); 238 break; 239 } 240 #endif 241 default: 242 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 243 == NULL) 244 return ENI_SYSTEM; 245 numaddrlen = strlen(numaddr); 246 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 247 return ENI_MEMORY; 248 strcpy(host, numaddr); 249 break; 250 } 251 } else { 252 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 253 h_error = h_errno; 254 255 if (hp) { 256 #if 0 257 /* 258 * commented out, since "for local host" is not 259 * implemented here - see RFC2553 p30 260 */ 261 if (flags & NI_NOFQDN) { 262 char *p; 263 p = strchr(hp->h_name, '.'); 264 if (p) 265 *p = '\0'; 266 } 267 #endif 268 if (strlen(hp->h_name) > hostlen) { 269 return ENI_MEMORY; 270 } 271 strcpy(host, hp->h_name); 272 } else { 273 if (flags & NI_NAMEREQD) 274 return ENI_NOHOSTNAME; 275 switch(afd->a_af) { 276 #ifdef INET6 277 case AF_INET6: 278 { 279 int error; 280 281 if ((error = ip6_parsenumeric(sa, addr, host, 282 hostlen, 283 flags)) != 0) 284 return(error); 285 break; 286 } 287 #endif 288 default: 289 if (inet_ntop(afd->a_af, addr, host, 290 hostlen) == NULL) 291 return ENI_SYSTEM; 292 break; 293 } 294 } 295 } 296 return SUCCESS; 297 } 298 299 #ifdef INET6 300 static int 301 ip6_parsenumeric(sa, addr, host, hostlen, flags) 302 const struct sockaddr *sa; 303 const char *addr; 304 char *host; 305 size_t hostlen; 306 int flags; 307 { 308 int numaddrlen; 309 char numaddr[512]; 310 311 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) 312 == NULL) 313 return ENI_SYSTEM; 314 315 numaddrlen = strlen(numaddr); 316 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 317 return ENI_MEMORY; 318 strcpy(host, numaddr); 319 320 #ifdef NI_WITHSCOPEID 321 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 322 if (flags & NI_WITHSCOPEID) 323 { 324 char scopebuf[MAXHOSTNAMELEN]; 325 int scopelen; 326 327 /* ip6_sa2str never fails */ 328 scopelen = ip6_sa2str((const struct sockaddr_in6 *)sa, 329 scopebuf, sizeof(scopebuf), 330 0); 331 if (scopelen + 1 + numaddrlen + 1 > hostlen) 332 return ENI_MEMORY; 333 /* 334 * construct <numeric-addr><delim><scopeid> 335 */ 336 memcpy(host + numaddrlen + 1, scopebuf, 337 scopelen); 338 host[numaddrlen] = SCOPE_DELIMITER; 339 host[numaddrlen + 1 + scopelen] = '\0'; 340 } 341 } 342 #endif /* NI_WITHSCOPEID */ 343 344 return 0; 345 } 346 347 /* ARGSUSED */ 348 static int 349 ip6_sa2str(sa6, buf, bufsiz, flags) 350 const struct sockaddr_in6 *sa6; 351 char *buf; 352 size_t bufsiz; 353 int flags; 354 { 355 unsigned int ifindex = (unsigned int)sa6->sin6_scope_id; 356 const struct in6_addr *a6 = &sa6->sin6_addr; 357 358 #ifdef notyet 359 if (flags & NI_NUMERICSCOPE) { 360 return(snprintf(buf, bufsiz, "%d", sa6->sin6_scope_id)); 361 } 362 #endif 363 364 /* if_indextoname() does not take buffer size. not a good api... */ 365 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 366 bufsiz >= IF_NAMESIZE) { 367 char *p = if_indextoname(ifindex, buf); 368 if (p) { 369 return(strlen(p)); 370 } 371 } 372 373 /* last resort */ 374 return(snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id)); 375 } 376 #endif /* INET6 */ 377
Indexes created Mon Sep 29 03:10:08 GMT 2025