1 /* $FreeBSD: src/lib/libc/net/getnameinfo.c,v 1.4.2.5 2002/07/31 10:11:09 ume Exp $ */ 2 /* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 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) always attach textual scopeid (fe80::1%lo0), if 42 * sin6_scope_id is filled - standardization status? 43 * XXX breaks backward compat for code that expects no scopeid. 44 * beware on merge. 45 */ 46 47 #include <sys/types.h> 48 #include <sys/socket.h> 49 #include <net/if.h> 50 #include <netinet/in.h> 51 #include <arpa/inet.h> 52 #include <arpa/nameser.h> 53 #include <netdb.h> 54 #include <resolv.h> 55 #include <string.h> 56 #include <stddef.h> 57 #include <errno.h> 58 59 static const struct afd { 60 int a_af; 61 int a_addrlen; 62 int a_socklen; 63 int a_off; 64 } afdl [] = { 65 #ifdef INET6 66 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 67 offsetof(struct sockaddr_in6, sin6_addr)}, 68 #endif 69 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 70 offsetof(struct sockaddr_in, sin_addr)}, 71 {0, 0, 0}, 72 }; 73 74 struct sockinet { 75 u_char si_len; 76 u_char si_family; 77 u_short si_port; 78 }; 79 80 #ifdef INET6 81 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *, 82 size_t, int)); 83 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int)); 84 #endif 85 86 int 87 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 88 const struct sockaddr *sa; 89 socklen_t salen; 90 char *host; 91 size_t hostlen; 92 char *serv; 93 size_t servlen; 94 int flags; 95 { 96 const struct afd *afd; 97 struct servent *sp; 98 struct hostent *hp; 99 u_short port; 100 int family, i; 101 const char *addr; 102 u_int32_t v4a; 103 int h_error; 104 char numserv[512]; 105 char numaddr[512]; 106 107 if (sa == NULL) 108 return EAI_FAIL; 109 110 if (sa->sa_len != salen) 111 return EAI_FAIL; 112 113 family = sa->sa_family; 114 for (i = 0; afdl[i].a_af; i++) 115 if (afdl[i].a_af == family) { 116 afd = &afdl[i]; 117 goto found; 118 } 119 return EAI_FAMILY; 120 121 found: 122 if (salen != afd->a_socklen) 123 return EAI_FAIL; 124 125 /* network byte order */ 126 port = ((const struct sockinet *)sa)->si_port; 127 addr = (const char *)sa + afd->a_off; 128 129 if (serv == NULL || servlen == 0) { 130 /* 131 * do nothing in this case. 132 * in case you are wondering if "&&" is more correct than 133 * "||" here: rfc2553bis-03 says that serv == NULL OR 134 * servlen == 0 means that the caller does not want the result. 135 */ 136 } else { 137 if (flags & NI_NUMERICSERV) 138 sp = NULL; 139 else { 140 sp = getservbyport(port, 141 (flags & NI_DGRAM) ? "udp" : "tcp"); 142 } 143 if (sp) { 144 if (strlen(sp->s_name) + 1 > servlen) 145 return EAI_MEMORY; 146 strlcpy(serv, sp->s_name, servlen); 147 } else { 148 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 149 if (strlen(numserv) + 1 > servlen) 150 return EAI_MEMORY; 151 strlcpy(serv, numserv, servlen); 152 } 153 } 154 155 switch (sa->sa_family) { 156 case AF_INET: 157 v4a = (u_int32_t) 158 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); 159 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 160 flags |= NI_NUMERICHOST; 161 v4a >>= IN_CLASSA_NSHIFT; 162 if (v4a == 0) 163 flags |= NI_NUMERICHOST; 164 break; 165 #ifdef INET6 166 case AF_INET6: 167 { 168 const struct sockaddr_in6 *sin6; 169 sin6 = (const struct sockaddr_in6 *)sa; 170 switch (sin6->sin6_addr.s6_addr[0]) { 171 case 0x00: 172 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 173 ; 174 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 175 ; 176 else 177 flags |= NI_NUMERICHOST; 178 break; 179 default: 180 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 181 flags |= NI_NUMERICHOST; 182 } 183 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 184 flags |= NI_NUMERICHOST; 185 break; 186 } 187 } 188 break; 189 #endif 190 } 191 if (host == NULL || hostlen == 0) { 192 /* 193 * do nothing in this case. 194 * in case you are wondering if "&&" is more correct than 195 * "||" here: rfc2553bis-03 says that host == NULL or 196 * hostlen == 0 means that the caller does not want the result. 197 */ 198 } else if (flags & NI_NUMERICHOST) { 199 int numaddrlen; 200 201 /* NUMERICHOST and NAMEREQD conflicts with each other */ 202 if (flags & NI_NAMEREQD) 203 return EAI_NONAME; 204 205 switch(afd->a_af) { 206 #ifdef INET6 207 case AF_INET6: 208 { 209 int error; 210 211 if ((error = ip6_parsenumeric(sa, addr, host, 212 hostlen, flags)) != 0) 213 return(error); 214 break; 215 } 216 #endif 217 default: 218 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 219 == NULL) 220 return EAI_SYSTEM; 221 numaddrlen = strlen(numaddr); 222 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 223 return EAI_MEMORY; 224 strlcpy(host, numaddr, hostlen); 225 break; 226 } 227 } else { 228 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 229 230 if (hp) { 231 #if 0 232 /* 233 * commented out, since "for local host" is not 234 * implemented here - see RFC2553 p30 235 */ 236 if (flags & NI_NOFQDN) { 237 char *p; 238 p = strchr(hp->h_name, '.'); 239 if (p) 240 *p = '\0'; 241 } 242 #endif 243 if (strlen(hp->h_name) + 1 > hostlen) { 244 freehostent(hp); 245 return EAI_MEMORY; 246 } 247 strlcpy(host, hp->h_name, hostlen); 248 freehostent(hp); 249 } else { 250 if (flags & NI_NAMEREQD) 251 return EAI_NONAME; 252 switch(afd->a_af) { 253 #ifdef INET6 254 case AF_INET6: 255 { 256 int error; 257 258 if ((error = ip6_parsenumeric(sa, addr, host, 259 hostlen, 260 flags)) != 0) 261 return(error); 262 break; 263 } 264 #endif 265 default: 266 if (inet_ntop(afd->a_af, addr, host, 267 hostlen) == NULL) 268 return EAI_SYSTEM; 269 break; 270 } 271 } 272 } 273 return(0); 274 } 275 276 #ifdef INET6 277 static int 278 ip6_parsenumeric(sa, addr, host, hostlen, flags) 279 const struct sockaddr *sa; 280 const char *addr; 281 char *host; 282 size_t hostlen; 283 int flags; 284 { 285 int numaddrlen; 286 char numaddr[512]; 287 288 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) 289 return EAI_SYSTEM; 290 291 numaddrlen = strlen(numaddr); 292 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 293 return EAI_MEMORY; 294 strlcpy(host, numaddr, hostlen); 295 296 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 297 char zonebuf[MAXHOSTNAMELEN]; 298 int zonelen; 299 300 zonelen = ip6_sa2str( 301 (const struct sockaddr_in6 *)(const void *)sa, 302 zonebuf, sizeof(zonebuf), flags); 303 if (zonelen < 0) 304 return EAI_MEMORY; 305 if (zonelen + 1 + numaddrlen + 1 > hostlen) 306 return EAI_MEMORY; 307 308 /* construct <numeric-addr><delim><zoneid> */ 309 memcpy(host + numaddrlen + 1, zonebuf, 310 (size_t)zonelen); 311 host[numaddrlen] = SCOPE_DELIMITER; 312 host[numaddrlen + 1 + zonelen] = '\0'; 313 } 314 315 return 0; 316 } 317 318 /* ARGSUSED */ 319 static int 320 ip6_sa2str(sa6, buf, bufsiz, flags) 321 const struct sockaddr_in6 *sa6; 322 char *buf; 323 size_t bufsiz; 324 int flags; 325 { 326 unsigned int ifindex; 327 const struct in6_addr *a6; 328 int n; 329 330 ifindex = (unsigned int)sa6->sin6_scope_id; 331 a6 = &sa6->sin6_addr; 332 333 #ifdef NI_NUMERICSCOPE 334 if ((flags & NI_NUMERICSCOPE) != 0) { 335 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 336 if (n < 0 || n >= bufsiz) 337 return -1; 338 else 339 return n; 340 } 341 #endif 342 343 /* if_indextoname() does not take buffer size. not a good api... */ 344 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 345 IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) { 346 char *p = if_indextoname(ifindex, buf); 347 if (p) { 348 return(strlen(p)); 349 } 350 } 351 352 /* last resort */ 353 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 354 if (n < 0 || n >= bufsiz) 355 return -1; 356 else 357 return n; 358 } 359 #endif /* INET6 */ 360