getnameinfo.c revision 1.3
1 /* $NetBSD: getnameinfo.c,v 1.3 1999/08/01 06:45:28 itojun 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 (RFC2133) 36 * but INRIA implementation returns EAI_xxx defined for getaddrinfo(). 37 */ 38 39 #include <sys/types.h> 40 #include <sys/socket.h> 41 #include <netinet/in.h> 42 #include <arpa/inet.h> 43 #include <arpa/nameser.h> 44 #include <netdb.h> 45 #include <resolv.h> 46 #include <string.h> 47 #include <stddef.h> 48 49 #define SUCCESS 0 50 #define ANY 0 51 #define YES 1 52 #define NO 0 53 54 static struct afd { 55 int a_af; 56 int a_addrlen; 57 int a_socklen; 58 int a_off; 59 } afdl [] = { 60 #ifdef INET6 61 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 62 offsetof(struct sockaddr_in6, sin6_addr)}, 63 #endif 64 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 65 offsetof(struct sockaddr_in, sin_addr)}, 66 {0, 0, 0}, 67 }; 68 69 struct sockinet { 70 u_char si_len; 71 u_char si_family; 72 u_short si_port; 73 }; 74 75 #define ENI_NOSOCKET 0 76 #define ENI_NOSERVNAME 1 77 #define ENI_NOHOSTNAME 2 78 #define ENI_MEMORY 3 79 #define ENI_SYSTEM 4 80 #define ENI_FAMILY 5 81 #define ENI_SALEN 6 82 83 int 84 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 85 const struct sockaddr *sa; 86 size_t salen; 87 char *host; 88 size_t hostlen; 89 char *serv; 90 size_t servlen; 91 int flags; 92 { 93 struct afd *afd; 94 struct servent *sp; 95 struct hostent *hp; 96 u_short port; 97 int family, len, i; 98 char *addr, *p; 99 u_long v4a; 100 int h_error; 101 char numserv[512]; 102 char numaddr[512]; 103 104 if (sa == NULL) 105 return ENI_NOSOCKET; 106 107 len = sa->sa_len; 108 if (len != salen) return ENI_SALEN; 109 110 family = sa->sa_family; 111 for (i = 0; afdl[i].a_af; i++) 112 if (afdl[i].a_af == family) { 113 afd = &afdl[i]; 114 goto found; 115 } 116 return ENI_FAMILY; 117 118 found: 119 if (len != afd->a_socklen) return ENI_SALEN; 120 121 port = ((struct sockinet *)sa)->si_port; /* network byte order */ 122 addr = (char *)sa + afd->a_off; 123 124 if (serv == NULL || servlen == 0) { 125 /* what we should do? */ 126 } else if (flags & NI_NUMERICSERV) { 127 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 128 if (strlen(numserv) > servlen) 129 return ENI_MEMORY; 130 strcpy(serv, numserv); 131 } else { 132 sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp"); 133 if (sp) { 134 if (strlen(sp->s_name) > servlen) 135 return ENI_MEMORY; 136 strcpy(serv, sp->s_name); 137 } else 138 return ENI_NOSERVNAME; 139 } 140 141 switch (sa->sa_family) { 142 case AF_INET: 143 v4a = ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr); 144 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 145 flags |= NI_NUMERICHOST; 146 v4a >>= IN_CLASSA_NSHIFT; 147 if (v4a == 0 || v4a == IN_LOOPBACKNET) 148 flags |= NI_NUMERICHOST; 149 break; 150 #ifdef INET6 151 case AF_INET6: 152 { 153 struct sockaddr_in6 *sin6; 154 sin6 = (struct sockaddr_in6 *)sa; 155 switch (sin6->sin6_addr.s6_addr8[0]) { 156 case 0x00: 157 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 158 ; 159 else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 160 ; 161 else 162 flags |= NI_NUMERICHOST; 163 break; 164 default: 165 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) 166 flags |= NI_NUMERICHOST; 167 else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 168 flags |= NI_NUMERICHOST; 169 break; 170 } 171 } 172 break; 173 #endif 174 } 175 if (host == NULL || hostlen == 0) { 176 /* what should we do? */ 177 } else if (flags & NI_NUMERICHOST) { 178 /* NUMERICHOST and NAMEREQD conflicts with each other */ 179 if (flags & NI_NAMEREQD) 180 return ENI_NOHOSTNAME; 181 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 182 == NULL) 183 return ENI_SYSTEM; 184 if (strlen(numaddr) > hostlen) 185 return ENI_MEMORY; 186 strcpy(host, numaddr); 187 } else { 188 #ifdef USE_GETIPNODEBY 189 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 190 #else 191 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 192 h_error = h_errno; 193 #endif 194 195 if (hp) { 196 if (flags & NI_NOFQDN) { 197 p = strchr(hp->h_name, '.'); 198 if (p) *p = '\0'; 199 } 200 if (strlen(hp->h_name) > hostlen) { 201 #ifdef USE_GETIPNODEBY 202 freehostent(hp); 203 #endif 204 return ENI_MEMORY; 205 } 206 strcpy(host, hp->h_name); 207 #ifdef USE_GETIPNODEBY 208 freehostent(hp); 209 #endif 210 } else { 211 if (flags & NI_NAMEREQD) 212 return ENI_NOHOSTNAME; 213 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 214 == NULL) 215 return ENI_NOHOSTNAME; 216 if (strlen(numaddr) > hostlen) 217 return ENI_MEMORY; 218 strcpy(host, numaddr); 219 } 220 } 221 return SUCCESS; 222 } 223
Indexes created Mon Sep 29 21:09:56 GMT 2025