getnameinfo.c revision 1.25
1 /* $NetBSD: getnameinfo.c,v 1.25 2001/01/25 22:50:56 jdolecek Exp $ */ 2 /* $KAME: getnameinfo.c,v 1.45 2000/09/25 22:43:56 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 * - RFC2553 says that we should raise error on short buffer. X/Open says 37 * we need to truncate the result. We obey RFC2553 (and X/Open should be 38 * modified). ipngwg rough consensus seems to follow RFC2553. 39 * - What is "local" in NI_FQDN? 40 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other. 41 * - (KAME extension) NI_WITHSCOPEID when called with global address, 42 * and sin6_scope_id filled 43 */ 44 45 #include <sys/cdefs.h> 46 #if defined(LIBC_SCCS) && !defined(lint) 47 __RCSID("$NetBSD: getnameinfo.c,v 1.25 2001/01/25 22:50:56 jdolecek Exp $"); 48 #endif /* LIBC_SCCS and not lint */ 49 50 #include "namespace.h" 51 #include <sys/types.h> 52 #include <sys/socket.h> 53 #include <net/if.h> 54 #include <netinet/in.h> 55 #include <arpa/inet.h> 56 #include <arpa/nameser.h> 57 #include <assert.h> 58 #include <netdb.h> 59 #include <resolv.h> 60 #include <stddef.h> 61 #include <string.h> 62 63 #ifdef __weak_alias 64 __weak_alias(getnameinfo,_getnameinfo) 65 #endif 66 67 #define SUCCESS 0 68 #define ANY 0 69 #define YES 1 70 #define NO 0 71 72 static const struct afd { 73 int a_af; 74 int a_addrlen; 75 int a_socklen; 76 int a_off; 77 } afdl [] = { 78 #ifdef INET6 79 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 80 offsetof(struct sockaddr_in6, sin6_addr)}, 81 #endif 82 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 83 offsetof(struct sockaddr_in, sin_addr)}, 84 {0, 0, 0}, 85 }; 86 87 struct sockinet { 88 u_char si_len; 89 u_char si_family; 90 u_short si_port; 91 }; 92 93 #ifdef INET6 94 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *, 95 size_t, int)); 96 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int)); 97 #endif 98 99 /* 2553bis: use EAI_xx for getnameinfo */ 100 #define ENI_NOSOCKET EAI_FAIL /*XXX*/ 101 #define ENI_NOSERVNAME EAI_NONAME 102 #define ENI_NOHOSTNAME EAI_NONAME 103 #define ENI_MEMORY EAI_MEMORY 104 #define ENI_SYSTEM EAI_SYSTEM 105 #define ENI_FAMILY EAI_FAMILY 106 #define ENI_SALEN EAI_FAMILY 107 108 int 109 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 110 const struct sockaddr *sa; 111 socklen_t salen; 112 char *host; 113 size_t hostlen; 114 char *serv; 115 size_t servlen; 116 int flags; 117 { 118 const 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 char numserv[512]; 126 char numaddr[512]; 127 128 /* sa is checked below */ 129 /* host may be NULL */ 130 /* serv may be NULL */ 131 132 if (sa == NULL) 133 return ENI_NOSOCKET; 134 135 #ifdef BSD4_4 136 if (sa->sa_len != salen) 137 return ENI_SALEN; 138 #endif 139 140 family = sa->sa_family; 141 for (i = 0; afdl[i].a_af; i++) 142 if (afdl[i].a_af == family) { 143 afd = &afdl[i]; 144 goto found; 145 } 146 return ENI_FAMILY; 147 148 found: 149 if (salen != afd->a_socklen) 150 return ENI_SALEN; 151 152 /* network byte order */ 153 port = ((const struct sockinet *)(const void *)sa)->si_port; 154 addr = (const char *)(const void *)sa + afd->a_off; 155 156 if (serv == NULL || servlen == 0) { 157 /* 158 * do nothing in this case. 159 * in case you are wondering if "&&" is more correct than 160 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 161 * means that the caller does not want the result. 162 */ 163 } else { 164 if (flags & NI_NUMERICSERV) 165 sp = NULL; 166 else { 167 sp = getservbyport(port, 168 (flags & NI_DGRAM) ? "udp" : "tcp"); 169 } 170 if (sp) { 171 if (strlen(sp->s_name) + 1 > servlen) 172 return ENI_MEMORY; 173 strcpy(serv, sp->s_name); 174 } else { 175 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 176 if (strlen(numserv) + 1 > servlen) 177 return ENI_MEMORY; 178 strcpy(serv, numserv); 179 } 180 } 181 182 switch (sa->sa_family) { 183 case AF_INET: 184 v4a = (u_int32_t) 185 ntohl(((const struct sockaddr_in *) 186 (const void *)sa)->sin_addr.s_addr); 187 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 188 flags |= NI_NUMERICHOST; 189 v4a >>= IN_CLASSA_NSHIFT; 190 if (v4a == 0) 191 flags |= NI_NUMERICHOST; 192 break; 193 #ifdef INET6 194 case AF_INET6: 195 { 196 const struct sockaddr_in6 *sin6; 197 sin6 = (const struct sockaddr_in6 *)(const void *)sa; 198 switch (sin6->sin6_addr.s6_addr[0]) { 199 case 0x00: 200 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 201 ; 202 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 203 ; 204 else 205 flags |= NI_NUMERICHOST; 206 break; 207 default: 208 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 209 flags |= NI_NUMERICHOST; 210 } 211 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 212 flags |= NI_NUMERICHOST; 213 break; 214 } 215 } 216 break; 217 #endif 218 } 219 if (host == NULL || hostlen == 0) { 220 /* 221 * do nothing in this case. 222 * in case you are wondering if "&&" is more correct than 223 * "||" here: RFC2553 says that host == NULL OR hostlen == 0 224 * means that the caller does not want the result. 225 */ 226 } else if (flags & NI_NUMERICHOST) { 227 int numaddrlen; 228 229 /* NUMERICHOST and NAMEREQD conflicts with each other */ 230 if (flags & NI_NAMEREQD) 231 return ENI_NOHOSTNAME; 232 233 switch(afd->a_af) { 234 #ifdef INET6 235 case AF_INET6: 236 { 237 int error; 238 239 if ((error = ip6_parsenumeric(sa, addr, host, 240 hostlen, flags)) != 0) 241 return(error); 242 break; 243 } 244 #endif 245 default: 246 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 247 == NULL) 248 return ENI_SYSTEM; 249 numaddrlen = strlen(numaddr); 250 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 251 return ENI_MEMORY; 252 strcpy(host, numaddr); 253 break; 254 } 255 } else { 256 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 257 258 if (hp) { 259 #if 0 260 /* 261 * commented out, since "for local host" is not 262 * implemented here - see RFC2553 p30 263 */ 264 if (flags & NI_NOFQDN) { 265 char *p; 266 p = strchr(hp->h_name, '.'); 267 if (p) 268 *p = '\0'; 269 } 270 #endif 271 if (strlen(hp->h_name) + 1 > hostlen) { 272 return ENI_MEMORY; 273 } 274 strcpy(host, hp->h_name); 275 } else { 276 if (flags & NI_NAMEREQD) 277 return ENI_NOHOSTNAME; 278 switch(afd->a_af) { 279 #ifdef INET6 280 case AF_INET6: 281 { 282 int error; 283 284 if ((error = ip6_parsenumeric(sa, addr, host, 285 hostlen, 286 flags)) != 0) 287 return(error); 288 break; 289 } 290 #endif 291 default: 292 if (inet_ntop(afd->a_af, addr, host, 293 hostlen) == NULL) 294 return ENI_SYSTEM; 295 break; 296 } 297 } 298 } 299 return SUCCESS; 300 } 301 302 #ifdef INET6 303 static int 304 ip6_parsenumeric(sa, addr, host, hostlen, flags) 305 const struct sockaddr *sa; 306 const char *addr; 307 char *host; 308 size_t hostlen; 309 int flags; 310 { 311 int numaddrlen; 312 char numaddr[512]; 313 314 _DIAGASSERT(sa != NULL); 315 _DIAGASSERT(addr != NULL); 316 _DIAGASSERT(host != NULL); 317 318 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) 319 == NULL) 320 return ENI_SYSTEM; 321 322 numaddrlen = strlen(numaddr); 323 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 324 return ENI_MEMORY; 325 strcpy(host, numaddr); 326 327 #ifdef NI_WITHSCOPEID 328 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) { 329 if (flags & NI_WITHSCOPEID) 330 { 331 char scopebuf[MAXHOSTNAMELEN]; 332 int scopelen; 333 334 /* ip6_sa2str never fails */ 335 scopelen = ip6_sa2str( 336 (const struct sockaddr_in6 *)(const void *)sa, 337 scopebuf, sizeof(scopebuf), 0); 338 if (scopelen + 1 + numaddrlen + 1 > hostlen) 339 return ENI_MEMORY; 340 /* 341 * construct <numeric-addr><delim><scopeid> 342 */ 343 memcpy(host + numaddrlen + 1, scopebuf, 344 (size_t)scopelen); 345 host[numaddrlen] = SCOPE_DELIMITER; 346 host[numaddrlen + 1 + scopelen] = '\0'; 347 } 348 } 349 #endif /* NI_WITHSCOPEID */ 350 351 return 0; 352 } 353 354 /* ARGSUSED */ 355 static int 356 ip6_sa2str(sa6, buf, bufsiz, flags) 357 const struct sockaddr_in6 *sa6; 358 char *buf; 359 size_t bufsiz; 360 int flags; 361 { 362 unsigned int ifindex; 363 const struct in6_addr *a6; 364 365 _DIAGASSERT(sa6 != NULL); 366 _DIAGASSERT(buf != NULL); 367 368 ifindex = (unsigned int)sa6->sin6_scope_id; 369 a6 = &sa6->sin6_addr; 370 371 #ifdef notyet 372 if (flags & NI_NUMERICSCOPE) { 373 return(snprintf(buf, bufsiz, "%d", sa6->sin6_scope_id)); 374 } 375 #endif 376 377 /* if_indextoname() does not take buffer size. not a good api... */ 378 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 379 bufsiz >= IF_NAMESIZE) { 380 char *p = if_indextoname(ifindex, buf); 381 if (p) { 382 return(strlen(p)); 383 } 384 } 385 386 /* last resort */ 387 return(snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id)); 388 } 389 #endif /* INET6 */ 390
Indexes created Sat Sep 27 22:09:54 GMT 2025