1 /* $NetBSD: getnameinfo.c,v 1.20 2000/07/06 02:54:12 christos Exp $ */ 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/cdefs.h> 48 #if defined(LIBC_SCCS) && !defined(lint) 49 __RCSID("$NetBSD: getnameinfo.c,v 1.20 2000/07/06 02:54:12 christos 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 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 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 if (sa == NULL) 129 return ENI_NOSOCKET; 130 131 #ifdef BSD4_4 132 if (sa->sa_len != salen) 133 return ENI_SALEN; 134 #endif 135 136 family = sa->sa_family; 137 for (i = 0; afdl[i].a_af; i++) 138 if (afdl[i].a_af == family) { 139 afd = &afdl[i]; 140 goto found; 141 } 142 return ENI_FAMILY; 143 144 found: 145 if (salen != afd->a_socklen) 146 return ENI_SALEN; 147 148 /* network byte order */ 149 port = ((const struct sockinet *)(const void *)sa)->si_port; 150 addr = (const char *)(const void *)sa + afd->a_off; 151 152 if (serv == NULL || servlen == 0) { 153 /* 154 * do nothing in this case. 155 * in case you are wondering if "&&" is more correct than 156 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 157 * means that the caller does not want the result. 158 */ 159 } else { 160 if (flags & NI_NUMERICSERV) 161 sp = NULL; 162 else { 163 sp = getservbyport(port, 164 (flags & NI_DGRAM) ? "udp" : "tcp"); 165 } 166 if (sp) { 167 if (strlen(sp->s_name) > servlen) 168 return ENI_MEMORY; 169 strcpy(serv, sp->s_name); 170 } else { 171 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 172 if (strlen(numserv) > servlen) 173 return ENI_MEMORY; 174 strcpy(serv, numserv); 175 } 176 } 177 178 switch (sa->sa_family) { 179 case AF_INET: 180 v4a = (u_int32_t) 181 ntohl(((const struct sockaddr_in *) 182 (const void *)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 *)(const void *)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); 253 254 if (hp) { 255 #if 0 256 /* 257 * commented out, since "for local host" is not 258 * implemented here - see RFC2553 p30 259 */ 260 if (flags & NI_NOFQDN) { 261 char *p; 262 p = strchr(hp->h_name, '.'); 263 if (p) 264 *p = '\0'; 265 } 266 #endif 267 if (strlen(hp->h_name) > hostlen) { 268 return ENI_MEMORY; 269 } 270 strcpy(host, hp->h_name); 271 } else { 272 if (flags & NI_NAMEREQD) 273 return ENI_NOHOSTNAME; 274 switch(afd->a_af) { 275 #ifdef INET6 276 case AF_INET6: 277 { 278 int error; 279 280 if ((error = ip6_parsenumeric(sa, addr, host, 281 hostlen, 282 flags)) != 0) 283 return(error); 284 break; 285 } 286 #endif 287 default: 288 if (inet_ntop(afd->a_af, addr, host, 289 hostlen) == NULL) 290 return ENI_SYSTEM; 291 break; 292 } 293 } 294 } 295 return SUCCESS; 296 } 297 298 #ifdef INET6 299 static int 300 ip6_parsenumeric(sa, addr, host, hostlen, flags) 301 const struct sockaddr *sa; 302 const char *addr; 303 char *host; 304 size_t hostlen; 305 int flags; 306 { 307 int numaddrlen; 308 char numaddr[512]; 309 310 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) 311 == NULL) 312 return ENI_SYSTEM; 313 314 numaddrlen = strlen(numaddr); 315 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 316 return ENI_MEMORY; 317 strcpy(host, numaddr); 318 319 #ifdef NI_WITHSCOPEID 320 if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) { 321 if (flags & NI_WITHSCOPEID) 322 { 323 char scopebuf[MAXHOSTNAMELEN]; 324 int scopelen; 325 326 /* ip6_sa2str never fails */ 327 scopelen = ip6_sa2str( 328 (const struct sockaddr_in6 *)(const void *)sa, 329 scopebuf, sizeof(scopebuf), 0); 330 if (scopelen + 1 + numaddrlen + 1 > hostlen) 331 return ENI_MEMORY; 332 /* 333 * construct <numeric-addr><delim><scopeid> 334 */ 335 memcpy(host + numaddrlen + 1, scopebuf, 336 (size_t)scopelen); 337 host[numaddrlen] = SCOPE_DELIMITER; 338 host[numaddrlen + 1 + scopelen] = '\0'; 339 } 340 } 341 #endif /* NI_WITHSCOPEID */ 342 343 return 0; 344 } 345 346 /* ARGSUSED */ 347 static int 348 ip6_sa2str(sa6, buf, bufsiz, flags) 349 const struct sockaddr_in6 *sa6; 350 char *buf; 351 size_t bufsiz; 352 int flags; 353 { 354 unsigned int ifindex = (unsigned int)sa6->sin6_scope_id; 355 const struct in6_addr *a6 = &sa6->sin6_addr; 356 357 #ifdef notyet 358 if (flags & NI_NUMERICSCOPE) { 359 return(snprintf(buf, bufsiz, "%d", sa6->sin6_scope_id)); 360 } 361 #endif 362 363 /* if_indextoname() does not take buffer size. not a good api... */ 364 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 365 bufsiz >= IF_NAMESIZE) { 366 char *p = if_indextoname(ifindex, buf); 367 if (p) { 368 return(strlen(p)); 369 } 370 } 371 372 /* last resort */ 373 return(snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id)); 374 } 375 #endif /* INET6 */ 376