getnameinfo.c revision 1.13
1 /* $NetBSD: getnameinfo.c,v 1.13 2000/03/17 06:11:55 christos Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the project nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 /* 33 * Issues to be discussed: 34 * - Thread safe-ness must be checked 35 * - Return values. There seems to be no standard for return value (RFC2553) 36 * but INRIA implementation returns EAI_xxx defined for getaddrinfo(). 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). 40 */ 41 42 #include <sys/types.h> 43 #include <sys/socket.h> 44 #include <net/if.h> 45 #include <netinet/in.h> 46 #include <arpa/inet.h> 47 #include <arpa/nameser.h> 48 #include <netdb.h> 49 #include <resolv.h> 50 #include <string.h> 51 #include <stddef.h> 52 53 #define SUCCESS 0 54 #define ANY 0 55 #define YES 1 56 #define NO 0 57 58 static struct afd { 59 int a_af; 60 int a_addrlen; 61 int a_socklen; 62 int a_off; 63 } afdl [] = { 64 #ifdef INET6 65 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 66 offsetof(struct sockaddr_in6, sin6_addr)}, 67 #endif 68 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 69 offsetof(struct sockaddr_in, sin_addr)}, 70 {0, 0, 0}, 71 }; 72 73 struct sockinet { 74 u_char si_len; 75 u_char si_family; 76 u_short si_port; 77 }; 78 79 #ifdef INET6 80 static char *ip6_sa2str __P((struct sockaddr_in6 *, char *, int)); 81 #endif 82 83 #define ENI_NOSOCKET 0 84 #define ENI_NOSERVNAME 1 85 #define ENI_NOHOSTNAME 2 86 #define ENI_MEMORY 3 87 #define ENI_SYSTEM 4 88 #define ENI_FAMILY 5 89 #define ENI_SALEN 6 90 91 int 92 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 93 const struct sockaddr *sa; 94 size_t salen; 95 char *host; 96 size_t hostlen; 97 char *serv; 98 size_t servlen; 99 int flags; 100 { 101 struct afd *afd; 102 struct servent *sp; 103 struct hostent *hp; 104 u_short port; 105 int family, i; 106 char *addr, *p; 107 u_int32_t v4a; 108 int h_error; 109 char numserv[512]; 110 char numaddr[512]; 111 112 if (sa == NULL) 113 return ENI_NOSOCKET; 114 115 #ifdef BSD4_4 116 if (sa->sa_len != salen) 117 return ENI_SALEN; 118 #endif 119 120 family = sa->sa_family; 121 for (i = 0; afdl[i].a_af; i++) 122 if (afdl[i].a_af == family) { 123 afd = &afdl[i]; 124 goto found; 125 } 126 return ENI_FAMILY; 127 128 found: 129 if (salen != afd->a_socklen) 130 return ENI_SALEN; 131 132 port = ((struct sockinet *)sa)->si_port; /* network byte order */ 133 addr = (char *)sa + afd->a_off; 134 135 if (serv == NULL || servlen == 0) { 136 /* 137 * do nothing in this case. 138 * in case you are wondering if "&&" is more correct than 139 * "||" here: RFC2553 says that serv == NULL OR servlen == 0 140 * means that the caller does not want the result. 141 */ 142 } else { 143 if (flags & NI_NUMERICSERV) 144 sp = NULL; 145 else { 146 sp = getservbyport(port, 147 (flags & NI_DGRAM) ? "udp" : "tcp"); 148 } 149 if (sp) { 150 if (strlen(sp->s_name) > servlen) 151 return ENI_MEMORY; 152 strcpy(serv, sp->s_name); 153 } else { 154 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 155 if (strlen(numserv) > servlen) 156 return ENI_MEMORY; 157 strcpy(serv, numserv); 158 } 159 } 160 161 switch (sa->sa_family) { 162 case AF_INET: 163 v4a = (u_int32_t) 164 ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr); 165 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 166 flags |= NI_NUMERICHOST; 167 v4a >>= IN_CLASSA_NSHIFT; 168 if (v4a == 0) 169 flags |= NI_NUMERICHOST; 170 break; 171 #ifdef INET6 172 case AF_INET6: 173 { 174 struct sockaddr_in6 *sin6; 175 sin6 = (struct sockaddr_in6 *)sa; 176 switch (sin6->sin6_addr.s6_addr[0]) { 177 case 0x00: 178 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 179 ; 180 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 181 ; 182 else 183 flags |= NI_NUMERICHOST; 184 break; 185 default: 186 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 187 flags |= NI_NUMERICHOST; 188 } 189 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 190 flags |= NI_NUMERICHOST; 191 break; 192 } 193 } 194 break; 195 #endif 196 } 197 if (host == NULL || hostlen == 0) { 198 /* 199 * do nothing in this case. 200 * in case you are wondering if "&&" is more correct than 201 * "||" here: RFC2553 says that host == NULL OR hostlen == 0 202 * means that the caller does not want the result. 203 */ 204 } else if (flags & NI_NUMERICHOST) { 205 int numaddrlen; 206 207 /* NUMERICHOST and NAMEREQD conflicts with each other */ 208 if (flags & NI_NAMEREQD) 209 return ENI_NOHOSTNAME; 210 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 211 == NULL) 212 return ENI_SYSTEM; 213 numaddrlen = strlen(numaddr); 214 if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 215 return ENI_MEMORY; 216 strcpy(host, numaddr); 217 #if defined(INET6) && defined(NI_WITHSCOPEID) 218 if (afd->a_af == AF_INET6 && 219 (IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)addr) || 220 IN6_IS_ADDR_MULTICAST((struct in6_addr *)addr)) && 221 ((struct sockaddr_in6 *)sa)->sin6_scope_id) { 222 #ifndef ALWAYS_WITHSCOPE 223 if (flags & NI_WITHSCOPEID) 224 #endif /* !ALWAYS_WITHSCOPE */ 225 { 226 char scopebuf[MAXHOSTNAMELEN], *s; 227 int scopelen; 228 229 if ((s = ip6_sa2str((struct sockaddr_in6 *)sa, 230 scopebuf, 0)) == NULL) 231 /* XXX what should we do? */ 232 strcpy(scopebuf, "0"); 233 234 scopelen = strlen(scopebuf); 235 if (scopelen + 1 + numaddrlen + 1 > hostlen) 236 return ENI_MEMORY; 237 238 #if 0 239 /* 240 * construct <scopeid><delim><numeric-addr> 241 */ 242 /* 243 * Shift the host string to allocate 244 * space for the scope ID part. 245 */ 246 memmove(host + scopelen + 1, host, 247 numaddrlen); 248 /* copy the scope ID and the delimiter */ 249 memcpy(host, scopebuf, scopelen); 250 host[scopelen] = SCOPE_DELIMITER; 251 host[scopelen + 1 + numaddrlen] = '\0'; 252 #else 253 /* 254 * construct <numeric-addr><delim><scopeid> 255 */ 256 memcpy(host + numaddrlen + 1, scopebuf, 257 scopelen); 258 host[numaddrlen] = SCOPE_DELIMITER; 259 host[numaddrlen + 1 + scopelen] = '\0'; 260 #endif 261 } 262 } 263 #endif /* INET6 */ 264 } else { 265 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 266 h_error = h_errno; 267 268 if (hp) { 269 if (flags & NI_NOFQDN) { 270 p = strchr(hp->h_name, '.'); 271 if (p) *p = '\0'; 272 } 273 if (strlen(hp->h_name) > hostlen) { 274 return ENI_MEMORY; 275 } 276 strcpy(host, hp->h_name); 277 } else { 278 if (flags & NI_NAMEREQD) 279 return ENI_NOHOSTNAME; 280 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 281 == NULL) 282 return ENI_NOHOSTNAME; 283 if (strlen(numaddr) > hostlen) 284 return ENI_MEMORY; 285 strcpy(host, numaddr); 286 } 287 } 288 return SUCCESS; 289 } 290 291 #ifdef INET6 292 /* ARGSUSED */ 293 static char * 294 ip6_sa2str(sa6, buf, flags) 295 struct sockaddr_in6 *sa6; 296 char *buf; 297 int flags; 298 { 299 unsigned int ifindex = (unsigned int)sa6->sin6_scope_id; 300 struct in6_addr *a6 = &sa6->sin6_addr; 301 302 #ifdef notyet 303 if (flags & NI_NUMERICSCOPE) { 304 sprintf(buf, "%d", sa6->sin6_scope_id); 305 return(buf); 306 } 307 #endif 308 309 if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) 310 return(if_indextoname(ifindex, buf)); 311 312 if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) 313 return(NULL); /* XXX */ 314 if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) 315 return(NULL); /* XXX */ 316 317 return(NULL); /* XXX */ 318 } 319 #endif 320
Indexes created Sun Sep 28 12:09:53 GMT 2025