1/* $NetBSD: getnameinfo.c,v 1.1.1.1 2009/04/12 15:33:39 christos Exp $ */ 2 3/* 4 * Issues to be discussed: 5 * - Thread safe-ness must be checked 6 */ 7 8#if ( defined(__linux__) || defined(__linux) || defined(LINUX) ) 9#ifndef IF_NAMESIZE 10# ifdef IFNAMSIZ 11# define IF_NAMESIZE IFNAMSIZ 12# else 13# define IF_NAMESIZE 16 14# endif 15#endif 16#endif 17 18/* 19 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 20 * All rights reserved. 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 3. All advertising materials mentioning features or use of this software 31 * must display the following acknowledgement: 32 * This product includes software developed by WIDE Project and 33 * its contributors. 34 * 4. Neither the name of the project nor the names of its contributors 35 * may be used to endorse or promote products derived from this software 36 * without specific prior written permission. 37 * 38 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 39 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 41 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 42 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 43 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 44 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 45 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 46 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 47 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 48 * SUCH DAMAGE. 49 */ 50 51#include <port_before.h> 52 53#include <sys/types.h> 54#include <sys/socket.h> 55 56#include <netinet/in.h> 57#include <arpa/nameser.h> 58#include <arpa/inet.h> 59#include <net/if.h> 60 61#include <netdb.h> 62#include <resolv.h> 63#include <string.h> 64#include <stddef.h> 65 66#include <port_after.h> 67 68/*% 69 * Note that a_off will be dynamically adjusted so that to be consistent 70 * with the definition of sockaddr_in{,6}. 71 * The value presented below is just a guess. 72 */ 73static struct afd { 74 int a_af; 75 int a_addrlen; 76 size_t a_socklen; 77 int a_off; 78} afdl [] = { 79 /* first entry is linked last... */ 80 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 81 offsetof(struct sockaddr_in, sin_addr)}, 82 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 83 offsetof(struct sockaddr_in6, sin6_addr)}, 84 {0, 0, 0, 0}, 85}; 86 87struct sockinet { 88#ifdef HAVE_SA_LEN 89 u_char si_len; 90#endif 91 u_char si_family; 92 u_short si_port; 93}; 94 95static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *, 96 size_t, int)); 97#ifdef HAVE_SIN6_SCOPE_ID 98static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int)); 99#endif 100 101int 102getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 103 const struct sockaddr *sa; 104 size_t salen; 105 char *host; 106 size_t hostlen; 107 char *serv; 108 size_t servlen; 109 int flags; 110{ 111 struct afd *afd; 112 struct servent *sp; 113 struct hostent *hp; 114 u_short port; 115#ifdef HAVE_SA_LEN 116 size_t len; 117#endif 118 int family, i; 119 const char *addr; 120 char *p; 121 char numserv[512]; 122 char numaddr[512]; 123 const struct sockaddr_in6 *sin6; 124 125 if (sa == NULL) 126 return EAI_FAIL; 127 128#ifdef HAVE_SA_LEN 129 len = sa->sa_len; 130 if (len != salen) return EAI_FAIL; 131#endif 132 133 family = sa->sa_family; 134 for (i = 0; afdl[i].a_af; i++) 135 if (afdl[i].a_af == family) { 136 afd = &afdl[i]; 137 goto found; 138 } 139 return EAI_FAMILY; 140 141 found: 142 if (salen != afd->a_socklen) return EAI_FAIL; 143 144 port = ((const struct sockinet *)sa)->si_port; /*%< network byte order */ 145 addr = (const char *)sa + afd->a_off; 146 147 if (serv == NULL || servlen == 0U) { 148 /* 149 * rfc2553bis says that serv == NULL or servlen == 0 means that 150 * the caller does not want the result. 151 */ 152 } else if (flags & NI_NUMERICSERV) { 153 sprintf(numserv, "%d", ntohs(port)); 154 if (strlen(numserv) > servlen) 155 return EAI_MEMORY; 156 strcpy(serv, numserv); 157 } else { 158 sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp"); 159 if (sp) { 160 if (strlen(sp->s_name) + 1 > servlen) 161 return EAI_MEMORY; 162 strcpy(serv, sp->s_name); 163 } else 164 return EAI_NONAME; 165 } 166 167 switch (sa->sa_family) { 168 case AF_INET: 169 if (ntohl(*(const u_int32_t *)addr) >> IN_CLASSA_NSHIFT == 0) 170 flags |= NI_NUMERICHOST; 171 break; 172 case AF_INET6: 173 sin6 = (const struct sockaddr_in6 *)sa; 174 switch (sin6->sin6_addr.s6_addr[0]) { 175 case 0x00: 176 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 177 ; 178 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 179 ; 180 else 181 flags |= NI_NUMERICHOST; 182 break; 183 default: 184 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 185 flags |= NI_NUMERICHOST; 186 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 187 flags |= NI_NUMERICHOST; 188 break; 189 } 190 break; 191 } 192 if (host == NULL || hostlen == 0U) { 193 /* 194 * rfc2553bis says that host == NULL or hostlen == 0 means that 195 * the caller does not want the result. 196 */ 197 } else if (flags & NI_NUMERICHOST) { 198 goto numeric; 199 } else { 200 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 201 202 if (hp) { 203 if (flags & NI_NOFQDN) { 204 p = strchr(hp->h_name, '.'); 205 if (p) *p = '\0'; 206 } 207 if (strlen(hp->h_name) + 1 > hostlen) 208 return EAI_MEMORY; 209 strcpy(host, hp->h_name); 210 } else { 211 if (flags & NI_NAMEREQD) 212 return EAI_NONAME; 213 numeric: 214 switch(afd->a_af) { 215 case AF_INET6: 216 { 217 int error; 218 219 if ((error = ip6_parsenumeric(sa, addr, host, 220 hostlen, 221 flags)) != 0) 222 return(error); 223 break; 224 } 225 226 default: 227 if (inet_ntop(afd->a_af, addr, numaddr, 228 sizeof(numaddr)) == NULL) 229 return EAI_NONAME; 230 if (strlen(numaddr) + 1 > hostlen) 231 return EAI_MEMORY; 232 strcpy(host, numaddr); 233 } 234 } 235 } 236 return(0); 237} 238 239static int 240ip6_parsenumeric(const struct sockaddr *sa, const char *addr, char *host, 241 size_t hostlen, int flags) 242{ 243 size_t numaddrlen; 244 char numaddr[512]; 245 246#ifndef HAVE_SIN6_SCOPE_ID 247 UNUSED(sa); 248 UNUSED(flags); 249#endif 250 251 if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) 252 == NULL) 253 return EAI_SYSTEM; 254 255 numaddrlen = strlen(numaddr); 256 if (numaddrlen + 1 > hostlen) /*%< don't forget terminator */ 257 return EAI_MEMORY; 258 strcpy(host, numaddr); 259 260#ifdef HAVE_SIN6_SCOPE_ID 261 if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 262 char scopebuf[MAXHOSTNAMELEN]; /*%< XXX */ 263 int scopelen; 264 265 /* ip6_sa2str never fails */ 266 scopelen = ip6_sa2str((const struct sockaddr_in6 *)sa, 267 scopebuf, sizeof(scopebuf), flags); 268 269 if (scopelen + 1 + numaddrlen + 1 > hostlen) 270 return EAI_MEMORY; 271 272 /* construct <numeric-addr><delim><scopeid> */ 273 memcpy(host + numaddrlen + 1, scopebuf, 274 scopelen); 275 host[numaddrlen] = SCOPE_DELIMITER; 276 host[numaddrlen + 1 + scopelen] = '\0'; 277 } 278#endif 279 280 return 0; 281} 282 283#ifdef HAVE_SIN6_SCOPE_ID 284/* ARGSUSED */ 285static int 286ip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, 287 size_t bufsiz, int flags) 288{ 289#ifdef USE_IFNAMELINKID 290 unsigned int ifindex = (unsigned int)sa6->sin6_scope_id; 291 const struct in6_addr *a6 = &sa6->sin6_addr; 292#endif 293 char tmp[64]; 294 295#ifdef NI_NUMERICSCOPE 296 if (flags & NI_NUMERICSCOPE) { 297 sprintf(tmp, "%u", sa6->sin6_scope_id); 298 if (bufsiz != 0U) { 299 strncpy(buf, tmp, bufsiz - 1); 300 buf[bufsiz - 1] = '\0'; 301 } 302 return(strlen(tmp)); 303 } 304#endif 305 306#ifdef USE_IFNAMELINKID 307 /* 308 * For a link-local address, convert the index to an interface 309 * name, assuming a one-to-one mapping between links and interfaces. 310 * Note, however, that this assumption is stronger than the 311 * specification of the scoped address architecture; the 312 * specficication says that more than one interfaces can belong to 313 * a single link. 314 */ 315 316 /* if_indextoname() does not take buffer size. not a good api... */ 317 if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) && 318 bufsiz >= IF_NAMESIZE) { 319 char *p = if_indextoname(ifindex, buf); 320 if (p) { 321 return(strlen(p)); 322 } 323 } 324#endif 325 326 /* last resort */ 327 sprintf(tmp, "%u", sa6->sin6_scope_id); 328 if (bufsiz != 0U) { 329 strncpy(buf, tmp, bufsiz - 1); 330 buf[bufsiz - 1] = '\0'; 331 } 332 return(strlen(tmp)); 333} 334#endif 335 336/*! \file */ 337