1 /*- 2 * Copyright (c) 1999 Brian Somers <brian@Awfulhak.org> 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 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29 #include <sys/param.h> 30 31 #include <sys/socket.h> 32 #include <netdb.h> 33 #include <netinet/in.h> 34 #include <arpa/inet.h> 35 36 #include <stdio.h> 37 #include <string.h> 38 39 #include "libutil.h" 40 41 /* wrapper for KAME-special getnameinfo() */ 42 #ifndef NI_WITHSCOPEID 43 #define NI_WITHSCOPEID 0 44 #endif 45 46 struct sockinet { 47 u_char si_len; 48 u_char si_family; 49 u_short si_port; 50 }; 51 52 int 53 realhostname(char *host, size_t hsize, const struct in_addr *ip) 54 { 55 int result; 56 struct hostent *hp; 57 58 result = HOSTNAME_INVALIDADDR; 59 hp = gethostbyaddr((char *)ip, sizeof(*ip), AF_INET); 60 61 if (hp != NULL && strlen(hp->h_name) <= hsize) { 62 char lookup[MAXHOSTNAMELEN]; 63 64 strncpy(lookup, hp->h_name, sizeof(lookup) - 1); 65 lookup[sizeof(lookup) - 1] = '\0'; 66 hp = gethostbyname(lookup); 67 if (hp == NULL) 68 result = HOSTNAME_INVALIDNAME; 69 else for (; ; hp->h_addr_list++) { 70 if (hp->h_addr_list[0] == NULL) { 71 result = HOSTNAME_INCORRECTNAME; 72 break; 73 } 74 if (!memcmp(*hp->h_addr_list, ip, sizeof(*ip))) { 75 strncpy(host, lookup, hsize); 76 return HOSTNAME_FOUND; 77 } 78 } 79 } 80 81 strncpy(host, inet_ntoa(*ip), hsize); 82 83 return result; 84 } 85 86 int 87 realhostname_sa(char *host, size_t hsize, struct sockaddr *addr, int addrlen) 88 { 89 int result, error; 90 char buf[NI_MAXHOST]; 91 92 result = HOSTNAME_INVALIDADDR; 93 94 error = getnameinfo(addr, addrlen, buf, sizeof(buf), NULL, 0, 0); 95 if (error == 0) { 96 struct addrinfo hints, *res, *ores; 97 struct sockaddr *sa; 98 99 memset(&hints, 0, sizeof(struct addrinfo)); 100 hints.ai_family = 101 (addr->sa_family == AF_INET) ? AF_INET : AF_UNSPEC; 102 hints.ai_flags = AI_CANONNAME; 103 104 error = getaddrinfo(buf, NULL, &hints, &res); 105 if (error) { 106 result = HOSTNAME_INVALIDNAME; 107 goto numeric; 108 } else for (ores = res; ; res = res->ai_next) { 109 if (res == NULL) { 110 freeaddrinfo(ores); 111 result = HOSTNAME_INCORRECTNAME; 112 goto numeric; 113 } 114 sa = res->ai_addr; 115 if (sa == NULL) { 116 freeaddrinfo(ores); 117 result = HOSTNAME_INCORRECTNAME; 118 goto numeric; 119 } 120 if (sa->sa_len == addrlen && 121 sa->sa_family == addr->sa_family) { 122 u_int16_t port; 123 124 port = ((struct sockinet *)addr)->si_port; 125 ((struct sockinet *)addr)->si_port = 0; 126 if (!memcmp(sa, addr, sa->sa_len)) { 127 result = HOSTNAME_FOUND; 128 ((struct sockinet *)addr)->si_port = 129 port; 130 if (res->ai_canonname == 0) { 131 freeaddrinfo(ores); 132 goto numeric; 133 } 134 if (strlen(res->ai_canonname) > hsize && 135 addr->sa_family == AF_INET) { 136 freeaddrinfo(ores); 137 goto numeric; 138 } 139 strncpy(host, res->ai_canonname, 140 hsize); 141 break; 142 } 143 ((struct sockinet *)addr)->si_port = port; 144 } 145 #ifdef INET6 146 /* 147 * XXX IPv4 mapped IPv6 addr consideraton, 148 * specified in rfc2373. 149 */ 150 if (sa->sa_family == AF_INET && 151 addr->sa_family == AF_INET6) { 152 struct in_addr *in; 153 struct in6_addr *in6; 154 155 in = &((struct sockaddr_in *)sa)->sin_addr; 156 in6 = &((struct sockaddr_in6 *)addr)->sin6_addr; 157 if (IN6_IS_ADDR_V4MAPPED(in6) && 158 !memcmp(&in6->s6_addr[12], in, 159 sizeof(*in))) { 160 result = HOSTNAME_FOUND; 161 if (res->ai_canonname == 0 || 162 strlen(res->ai_canonname) > hsize) { 163 freeaddrinfo(ores); 164 goto numeric; 165 } 166 strncpy(host, res->ai_canonname, 167 hsize); 168 break; 169 } 170 } 171 #endif 172 } 173 freeaddrinfo(ores); 174 } else { 175 struct sockaddr_in sin; 176 numeric: 177 #ifdef INET6 178 if (addr->sa_family == AF_INET6) { 179 struct sockaddr_in6 *sin6; 180 181 sin6 = (struct sockaddr_in6 *)addr; 182 if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) { 183 memset(&sin, 0, sizeof(sin)); 184 sin.sin_len = sizeof(struct sockaddr_in); 185 sin.sin_family = AF_INET; 186 sin.sin_port = sin6->sin6_port; 187 memcpy(&sin.sin_addr, 188 &sin6->sin6_addr.s6_addr[12], 189 sizeof(struct in_addr)); 190 addr = (struct sockaddr *)&sin; 191 addrlen = sin.sin_len; 192 } 193 } 194 #endif 195 if (getnameinfo(addr, addrlen, buf, sizeof(buf), NULL, 0, 196 NI_NUMERICHOST|NI_WITHSCOPEID) == 0) 197 strncpy(host, buf, hsize); 198 } 199 200 return result; 201 } 202 203 204