getnameinfo.c revision 1.1
1 /* 2 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the project nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 /* 31 * Issues to be discussed: 32 * - Thread safe-ness must be checked 33 * - Return values. There seems to be no standard for return value (RFC2133) 34 * but INRIA implementation returns EAI_xxx defined for getaddrinfo(). 35 */ 36 37 #include <sys/types.h> 38 #include <sys/socket.h> 39 #include <netinet/in.h> 40 #include <arpa/inet.h> 41 #include <arpa/nameser.h> 42 #include <netdb.h> 43 #include <resolv.h> 44 #include <string.h> 45 #include <stddef.h> 46 47 #define SUCCESS 0 48 #define ANY 0 49 #define YES 1 50 #define NO 0 51 52 static struct afd { 53 int a_af; 54 int a_addrlen; 55 int a_socklen; 56 int a_off; 57 } afdl [] = { 58 #ifdef INET6 59 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 60 offsetof(struct sockaddr_in6, sin6_addr)}, 61 #endif 62 {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 63 offsetof(struct sockaddr_in, sin_addr)}, 64 {0, 0, 0}, 65 }; 66 67 struct sockinet { 68 u_char si_len; 69 u_char si_family; 70 u_short si_port; 71 }; 72 73 #define ENI_NOSOCKET 0 74 #define ENI_NOSERVNAME 1 75 #define ENI_NOHOSTNAME 2 76 #define ENI_MEMORY 3 77 #define ENI_SYSTEM 4 78 #define ENI_FAMILY 5 79 #define ENI_SALEN 6 80 81 int 82 getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) 83 const struct sockaddr *sa; 84 size_t salen; 85 char *host; 86 size_t hostlen; 87 char *serv; 88 size_t servlen; 89 int flags; 90 { 91 struct afd *afd; 92 struct servent *sp; 93 struct hostent *hp; 94 u_short port; 95 int family, len, i; 96 char *addr, *p; 97 u_long v4a; 98 u_char pfx; 99 int h_error; 100 char numserv[512]; 101 char numaddr[512]; 102 103 if (sa == NULL) 104 return ENI_NOSOCKET; 105 106 len = sa->sa_len; 107 if (len != salen) return ENI_SALEN; 108 109 family = sa->sa_family; 110 for (i = 0; afdl[i].a_af; i++) 111 if (afdl[i].a_af == family) { 112 afd = &afdl[i]; 113 goto found; 114 } 115 return ENI_FAMILY; 116 117 found: 118 if (len != afd->a_socklen) return ENI_SALEN; 119 120 port = ((struct sockinet *)sa)->si_port; /* network byte order */ 121 addr = (char *)sa + afd->a_off; 122 123 if (serv == NULL || servlen == 0) { 124 /* what we should do? */ 125 } else if (flags & NI_NUMERICSERV) { 126 snprintf(numserv, sizeof(numserv), "%d", ntohs(port)); 127 if (strlen(numserv) > servlen) 128 return ENI_MEMORY; 129 strcpy(serv, numserv); 130 } else { 131 sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp"); 132 if (sp) { 133 if (strlen(sp->s_name) > servlen) 134 return ENI_MEMORY; 135 strcpy(serv, sp->s_name); 136 } else 137 return ENI_NOSERVNAME; 138 } 139 140 switch (sa->sa_family) { 141 case AF_INET: 142 v4a = ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr); 143 if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 144 flags |= NI_NUMERICHOST; 145 v4a >>= IN_CLASSA_NSHIFT; 146 if (v4a == 0 || v4a == IN_LOOPBACKNET) 147 flags |= NI_NUMERICHOST; 148 break; 149 #ifdef INET6 150 case AF_INET6: 151 pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr8[0]; 152 if (pfx == 0 || pfx == 0xfe || pfx == 0xff) 153 flags |= NI_NUMERICHOST; 154 break; 155 #endif 156 } 157 if (host == NULL || hostlen == 0) { 158 /* what should we do? */ 159 } else if (flags & NI_NUMERICHOST) { 160 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 161 == NULL) 162 return ENI_SYSTEM; 163 if (strlen(numaddr) > hostlen) 164 return ENI_MEMORY; 165 strcpy(host, numaddr); 166 } else { 167 #ifdef USE_GETIPNODEBY 168 hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 169 #else 170 hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); 171 h_error = h_errno; 172 #endif 173 174 if (hp) { 175 if (flags & NI_NOFQDN) { 176 p = strchr(hp->h_name, '.'); 177 if (p) *p = '\0'; 178 } 179 if (strlen(hp->h_name) > hostlen) { 180 #ifdef USE_GETIPNODEBY 181 freehostent(hp); 182 #endif 183 return ENI_MEMORY; 184 } 185 strcpy(host, hp->h_name); 186 #ifdef USE_GETIPNODEBY 187 freehostent(hp); 188 #endif 189 } else { 190 if (flags & NI_NAMEREQD) 191 return ENI_NOHOSTNAME; 192 if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 193 == NULL) 194 return ENI_NOHOSTNAME; 195 if (strlen(numaddr) > hostlen) 196 return ENI_MEMORY; 197 strcpy(host, numaddr); 198 } 199 } 200 return SUCCESS; 201 } 202
Indexes created Mon Sep 29 13:09:55 GMT 2025