1 /* $FreeBSD$ */ 2 /* $KAME: getnameinfo.c,v 1.43 2000/06/12 04:27:03 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/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 #define SUCCESS 0 60 #define ANY 0 61 #define YES 1 62 #define NO 0 63 64 static struct afd { 65 int a_af; 66 int a_addrlen; 67 int a_socklen; 68 int a_off; 69 } afdl [] = { 70 #ifdef INET6 71 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 72 offsetof(struct sockaddr_in6, sin6_addr)}, 73 #endif 74 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 75 offsetof(struct sockaddr_in, sin_addr)}, 76 {0, 0, 0}, 77 }; 78 79 struct sockinet { 80 u_char si_len; 81 u_char si_family; 82 u_short si_port; 83 }; 84 85 #ifdef INET6 86 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *, 87 size_t, int)); 88 static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int)); 89 #endif 90 91 #define ENI_NOSOCKET EAI_FAIL /*XXX*/ 92 #define ENI_NOSERVNAME EAI_NONAME 93 #define ENI_NOHOSTNAME EAI_NONAME 94 #define ENI_MEMORY EAI_MEMORY 95 #define ENI_SYSTEM EAI_SYSTEM 96 #define ENI_FAMILY EAI_FAMILY 97 #define ENI_SALEN EAI_FAMILY 98 99 int 100 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 101 const struct sockaddr *sa; 102 size_t salen; 103 char *host; 104 size_t hostlen; 105 char *serv; 106 size_t servlen; 107 int flags; 108 { 109 struct afd *afd; 110 struct servent *sp; 111 struct hostent *hp; 112 u_short port; 113 int family, i; 114 const char *addr; 115 u_int32_t v4a; 116 int h_error; 117 char numserv[512]; 118 char numaddr[512]; 119 120 if (sa == NULL) 121 return ENI_NOSOCKET; 122 123 if (sa->sa_len != salen) 124 return ENI_SALEN; 125 126 family = sa->sa_family; 127 for (i = 0; afdl[i].a_af; i++) 128 if (afdl[i].a_af == family) { 129 afd = &afdl[i]; 130 goto found; 131 } 132 return ENI_FAMILY; 133 134 found: 135 if (salen != afd->a_socklen) 136 return ENI_SALEN; 137 138 /* network byte order */ 139 port = ((const struct sockinet *)sa)->si_port; 140 addr = (const char *)sa + afd->a_off; 141 142 if (serv == NULL || servlen == 0) { 143 /* 144 * do nothing in this case. 145 * in case you are wondering if "&&" is more correct than 146 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 147 * means that the caller does not want the result. 148 */ 149 } else { 150 if (flags & NI_NUMERICSERV) 151 sp = NULL; 152 else { 153 sp = getservbyport(port, 154 (flags & NI_DGRAM) ? "udp" : "tcp"); 155 } 156 if (sp) { 157 if (strlen(sp->s_name) > servlen) 158 return ENI_MEMORY; 159 strcpy(serv, sp->s_name); 160 } else { 161 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 162 if (strlen(numserv) > servlen) 163 return ENI_MEMORY; 164 strcpy(serv, numserv); 165 } 166 } 167 168 switch (sa->sa_family) { 169 case AF_INET: 170 v4a = (u_int32_t) 171 ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); 172 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 173 flags |= NI_NUMERICHOST; 174 v4a >>= IN_CLASSA_NSHIFT; 175 if (v4a == 0) 176 flags |= NI_NUMERICHOST; 177 break; 178 #ifdef INET6 179 case AF_INET6: 180 { 181 const struct sockaddr_in6 *sin6; 182 sin6 = (const struct sockaddr_in6 *)sa; 183 switch (sin6->sin6_addr.s6_addr[0]) { 184 case 0x00: 185 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 186 ; 187 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 188 ; 189 else 190 flags |= NI_NUMERICHOST; 191 break; 192 default: 193 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 194 flags |= NI_NUMERICHOST; 195 } 196 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 197 flags |= NI_NUMERICHOST; 198 break; 199 } 200 } 201 break; 202 #endif 203 } 204 if (host == NULL || hostlen == 0) { 205 /* 206 * do nothing in this case. 207 * in case you are wondering if "&&" is more correct than 208 * "||" here: RFC2553 says that host == NULL OR hostlen == 0 209 * means that the caller does not want the result. 210 */ 211 } else if (flags & NI_NUMERICHOST) { 212 int numaddrlen; 213 214 /* NUMERICHOST and NAMEREQD conflicts with each other */ 215 if (flags & NI_NAMEREQD) 216 return ENI_NOHOSTNAME; 217 218 switch(afd->a_af) { 219 #ifdef INET6 220 case AF_INET6: 221 { 222 int error; 223 224 if ((error = ip6_parsenumeric(sa, addr, host, 225 hostlen, flags)) != 0) 226 return(error); 227 break; 228 } 229 #endif 230 default: 231 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 232 == NULL) 233 return ENI_SYSTEM; 234 numaddrlen = strlen(numaddr); 235 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 236 return ENI_MEMORY; 237 strcpy(host, numaddr); 238 break; 239 } 240 } else { 241 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 242 243 if (hp) { 244 #if 0 245 /* 246 * commented out, since "for local host" is not 247 * implemented here - see RFC2553 p30 248 */ 249 if (flags & NI_NOFQDN) { 250 char *p; 251 p = strchr(hp->h_name, '.'); 252 if (p) 253 *p = '\0'; 254 } 255 #endif 256 if (strlen(hp->h_name) > hostlen) { 257 freehostent(hp); 258 return ENI_MEMORY; 259 } 260 strcpy(host, hp->h_name); 261 freehostent(hp); 262 } else { 263 if (flags & NI_NAMEREQD) 264 return ENI_NOHOSTNAME; 265 switch(afd->a_af) { 266 #ifdef INET6 267 case AF_INET6: 268 { 269 int error; 270 271 if ((error = ip6_parsenumeric(sa, addr, host, 272 hostlen, 273 flags)) != 0) 274 return(error); 275 break; 276 } 277 #endif 278 default: 279 if (inet_ntop(afd->a_af, addr, host, 280 hostlen) == NULL) 281 return ENI_SYSTEM; 282 break; 283 } 284 } 285 } 286 return SUCCESS; 287 } 288 289 #ifdef INET6 290 static int 291 ip6_parsenumeric(sa, addr, host, hostlen, flags) 292 const struct sockaddr *sa; 293 const char *addr; 294 char *host; 295 size_t hostlen; 296 int flags; 297 { 298 int numaddrlen; 299 char numaddr[512]; 300 301 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) 302 == NULL) 303 return ENI_SYSTEM; 304 305 numaddrlen = strlen(numaddr); 306 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 307 return ENI_MEMORY; 308 strcpy(host, numaddr); 309 310 #ifdef NI_WITHSCOPEID 311 if ( 312 #ifdef DONT_OPAQUE_SCOPEID 313 (IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr) || 314 IN6_IS_ADDR_MULTICAST((struct in6_addr *)addr)) && 315 #endif 316 ((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 317 #ifndef ALWAYS_WITHSCOPE 318 if (flags & NI_WITHSCOPEID) 319 #endif /* !ALWAYS_WITHSCOPE */ 320 { 321 char scopebuf[MAXHOSTNAMELEN]; 322 int scopelen; 323 324 /* ip6_sa2str never fails */ 325 scopelen = ip6_sa2str((const struct sockaddr_in6 *)sa, 326 scopebuf, sizeof(scopebuf), 327 flags); 328 if (scopelen + 1 + numaddrlen + 1 > hostlen) 329 return ENI_MEMORY; 330 /* 331 * construct <numeric-addr><delim><scopeid> 332 */ 333 memcpy(host + numaddrlen + 1, scopebuf, 334 scopelen); 335 host[numaddrlen] = SCOPE_DELIMITER; 336 host[numaddrlen + 1 + scopelen] = '\0'; 337 } 338 } 339 #endif /* NI_WITHSCOPEID */ 340 341 return 0; 342 } 343 344 /* ARGSUSED */ 345 static int 346 ip6_sa2str(sa6, buf, bufsiz, flags) 347 const struct sockaddr_in6 *sa6; 348 char *buf; 349 size_t bufsiz; 350 int flags; 351 { 352 unsigned int ifindex = (unsigned int)sa6->sin6_scope_id; 353 const struct in6_addr *a6 = &sa6->sin6_addr; 354 355 #ifdef NI_NUMERICSCOPE 356 if (flags & NI_NUMERICSCOPE) { 357 return(snprintf(buf, bufsiz, "%d", sa6->sin6_scope_id)); 358 } 359 #endif 360 361 /* if_indextoname() does not take buffer size. not a good api... */ 362 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 363 bufsiz >= IF_NAMESIZE) { 364 char *p = if_indextoname(ifindex, buf); 365 if (p) { 366 return(strlen(p)); 367 } 368 } 369 370 /* last resort */ 371 return(snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id)); 372 } 373 #endif /* INET6 */ 374