1 /* $FreeBSD: src/lib/libc/net/getnameinfo.c,v 1.4.2.5 2002/07/31 10:11:09 ume Exp $ */ 2 /* $DragonFly: src/lib/libc/net/getnameinfo.c,v 1.3 2003/11/12 20:21:24 eirikn Exp $ */ 3 /* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 itojun Exp $ */ 4 5 /* 6 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. Neither the name of the project nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 /* 35 * Issues to be discussed: 36 * - Thread safe-ness must be checked 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). ipngwg rough consensus seems to follow RFC2553. 40 * - What is "local" in NI_FQDN? 41 * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other. 42 * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if 43 * sin6_scope_id is filled - standardization status? 44 * XXX breaks backward compat for code that expects no scopeid. 45 * beware on merge. 46 */ 47 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 #include <errno.h> 59 60 static const struct afd { 61 int a_af; 62 int a_addrlen; 63 int a_socklen; 64 int a_off; 65 } afdl [] = { 66 #ifdef INET6 67 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 68 offsetof(struct sockaddr_in6, sin6_addr)}, 69 #endif 70 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 71 offsetof(struct sockaddr_in, sin_addr)}, 72 {0, 0, 0}, 73 }; 74 75 struct sockinet { 76 u_char si_len; 77 u_char si_family; 78 u_short si_port; 79 }; 80 81 #ifdef INET6 82 static int ip6_parsenumeric (const struct sockaddr *, const char *, char *, 83 size_t, int); 84 static int ip6_sa2str (const struct sockaddr_in6 *, char *, size_t, int); 85 #endif 86 87 int 88 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 89 const struct sockaddr *sa; 90 socklen_t salen; 91 char *host; 92 size_t hostlen; 93 char *serv; 94 size_t servlen; 95 int flags; 96 { 97 const struct afd *afd; 98 struct servent *sp; 99 struct hostent *hp; 100 u_short port; 101 int family, i; 102 const char *addr; 103 u_int32_t v4a; 104 int h_error; 105 char numserv[512]; 106 char numaddr[512]; 107 108 if (sa == NULL) 109 return EAI_FAIL; 110 111 if (sa->sa_len != salen) 112 return EAI_FAIL; 113 114 family = sa->sa_family; 115 for (i = 0; afdl[i].a_af; i++) 116 if (afdl[i].a_af == family) { 117 afd = &afdl[i]; 118 goto found; 119 } 120 return EAI_FAMILY; 121 122 found: 123 if (salen != afd->a_socklen) 124 return EAI_FAIL; 125 126 /* network byte order */ 127 port = ((const struct sockinet *)sa)->si_port; 128 addr = (const char *)sa + afd->a_off; 129 130 if (serv == NULL || servlen == 0) { 131 /* 132 * do nothing in this case. 133 * in case you are wondering if "&&" is more correct than 134 * "||" here: rfc2553bis-03 says that serv == NULL OR 135 * servlen == 0 means that the caller does not want the result. 136 */ 137 } else { 138 if (flags & NI_NUMERICSERV) 139 sp = NULL; 140 else { 141 sp = getservbyport(port, 142 (flags & NI_DGRAM) ? "udp" : "tcp"); 143 } 144 if (sp) { 145 if (strlen(sp->s_name) + 1 > servlen) 146 return EAI_MEMORY; 147 strlcpy(serv, sp->s_name, servlen); 148 } else { 149 snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 150 if (strlen(numserv) + 1 > servlen) 151 return EAI_MEMORY; 152 strlcpy(serv, numserv, servlen); 153 } 154 } 155 156 switch (sa->sa_family) { 157 case AF_INET: 158 v4a = (u_int32_t) 159 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); 160 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 161 flags |= NI_NUMERICHOST; 162 v4a >>= IN_CLASSA_NSHIFT; 163 if (v4a == 0) 164 flags |= NI_NUMERICHOST; 165 break; 166 #ifdef INET6 167 case AF_INET6: 168 { 169 const struct sockaddr_in6 *sin6; 170 sin6 = (const struct sockaddr_in6 *)sa; 171 switch (sin6->sin6_addr.s6_addr[0]) { 172 case 0x00: 173 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 174 ; 175 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 176 ; 177 else 178 flags |= NI_NUMERICHOST; 179 break; 180 default: 181 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 182 flags |= NI_NUMERICHOST; 183 } 184 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 185 flags |= NI_NUMERICHOST; 186 break; 187 } 188 } 189 break; 190 #endif 191 } 192 if (host == NULL || hostlen == 0) { 193 /* 194 * do nothing in this case. 195 * in case you are wondering if "&&" is more correct than 196 * "||" here: rfc2553bis-03 says that host == NULL or 197 * hostlen == 0 means that the caller does not want the result. 198 */ 199 } else if (flags & NI_NUMERICHOST) { 200 int numaddrlen; 201 202 /* NUMERICHOST and NAMEREQD conflicts with each other */ 203 if (flags & NI_NAMEREQD) 204 return EAI_NONAME; 205 206 switch(afd->a_af) { 207 #ifdef INET6 208 case AF_INET6: 209 { 210 int error; 211 212 if ((error = ip6_parsenumeric(sa, addr, host, 213 hostlen, flags)) != 0) 214 return(error); 215 break; 216 } 217 #endif 218 default: 219 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 220 == NULL) 221 return EAI_SYSTEM; 222 numaddrlen = strlen(numaddr); 223 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 224 return EAI_MEMORY; 225 strlcpy(host, numaddr, hostlen); 226 break; 227 } 228 } else { 229 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 230 231 if (hp) { 232 #if 0 233 /* 234 * commented out, since "for local host" is not 235 * implemented here - see RFC2553 p30 236 */ 237 if (flags & NI_NOFQDN) { 238 char *p; 239 p = strchr(hp->h_name, '.'); 240 if (p) 241 *p = '\0'; 242 } 243 #endif 244 if (strlen(hp->h_name) + 1 > hostlen) { 245 freehostent(hp); 246 return EAI_MEMORY; 247 } 248 strlcpy(host, hp->h_name, hostlen); 249 freehostent(hp); 250 } else { 251 if (flags & NI_NAMEREQD) 252 return EAI_NONAME; 253 switch(afd->a_af) { 254 #ifdef INET6 255 case AF_INET6: 256 { 257 int error; 258 259 if ((error = ip6_parsenumeric(sa, addr, host, 260 hostlen, 261 flags)) != 0) 262 return(error); 263 break; 264 } 265 #endif 266 default: 267 if (inet_ntop(afd->a_af, addr, host, 268 hostlen) == NULL) 269 return EAI_SYSTEM; 270 break; 271 } 272 } 273 } 274 return(0); 275 } 276 277 #ifdef INET6 278 static int 279 ip6_parsenumeric(sa, addr, host, hostlen, flags) 280 const struct sockaddr *sa; 281 const char *addr; 282 char *host; 283 size_t hostlen; 284 int flags; 285 { 286 int numaddrlen; 287 char numaddr[512]; 288 289 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) 290 return EAI_SYSTEM; 291 292 numaddrlen = strlen(numaddr); 293 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 294 return EAI_MEMORY; 295 strlcpy(host, numaddr, hostlen); 296 297 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 298 char zonebuf[MAXHOSTNAMELEN]; 299 int zonelen; 300 301 zonelen = ip6_sa2str( 302 (const struct sockaddr_in6 *)(const void *)sa, 303 zonebuf, sizeof(zonebuf), flags); 304 if (zonelen < 0) 305 return EAI_MEMORY; 306 if (zonelen + 1 + numaddrlen + 1 > hostlen) 307 return EAI_MEMORY; 308 309 /* construct <numeric-addr><delim><zoneid> */ 310 memcpy(host + numaddrlen + 1, zonebuf, 311 (size_t)zonelen); 312 host[numaddrlen] = SCOPE_DELIMITER; 313 host[numaddrlen + 1 + zonelen] = '\0'; 314 } 315 316 return 0; 317 } 318 319 /* ARGSUSED */ 320 static int 321 ip6_sa2str(sa6, buf, bufsiz, flags) 322 const struct sockaddr_in6 *sa6; 323 char *buf; 324 size_t bufsiz; 325 int flags; 326 { 327 unsigned int ifindex; 328 const struct in6_addr *a6; 329 int n; 330 331 ifindex = (unsigned int)sa6->sin6_scope_id; 332 a6 = &sa6->sin6_addr; 333 334 #ifdef NI_NUMERICSCOPE 335 if ((flags & NI_NUMERICSCOPE) != 0) { 336 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 337 if (n < 0 || n >= bufsiz) 338 return -1; 339 else 340 return n; 341 } 342 #endif 343 344 /* if_indextoname() does not take buffer size. not a good api... */ 345 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 346 IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) { 347 char *p = if_indextoname(ifindex, buf); 348 if (p) { 349 return(strlen(p)); 350 } 351 } 352 353 /* last resort */ 354 n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 355 if (n < 0 || n >= bufsiz) 356 return -1; 357 else 358 return n; 359 } 360 #endif /* INET6 */ 361