1/* 2 * Copyright (C) 1996-2001 Internet Software Consortium. 3 * 4 * Permission to use, copy, modify, and distribute this software for any 5 * purpose with or without fee is hereby granted, provided that the above 6 * copyright notice and this permission notice appear in all copies. 7 * 8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM 9 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL 10 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL 11 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, 12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING 13 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, 14 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 15 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17/* 18 * Original code by Paul Vixie. "curlified" by Gisle Vanem. 19 */ 20 21#include "setup.h" 22 23#ifndef HAVE_INET_NTOP 24 25#ifdef HAVE_SYS_PARAM_H 26#include <sys/param.h> 27#endif 28#ifdef HAVE_SYS_SOCKET_H 29#include <sys/socket.h> 30#endif 31#ifdef HAVE_NETINET_IN_H 32#include <netinet/in.h> 33#endif 34#ifdef HAVE_ARPA_INET_H 35#include <arpa/inet.h> 36#endif 37 38#define _MPRINTF_REPLACE /* use our functions only */ 39#include <curl/mprintf.h> 40 41#include "inet_ntop.h" 42 43#define IN6ADDRSZ 16 44#define INADDRSZ 4 45#define INT16SZ 2 46 47/* 48 * Format an IPv4 address, more or less like inet_ntoa(). 49 * 50 * Returns `dst' (as a const) 51 * Note: 52 * - uses no statics 53 * - takes a unsigned char* not an in_addr as input 54 */ 55static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size) 56{ 57 char tmp[sizeof "255.255.255.255"]; 58 size_t len; 59 60 DEBUGASSERT(size >= 16); 61 62 tmp[0] = '\0'; 63 (void)snprintf(tmp, sizeof(tmp), "%d.%d.%d.%d", 64 ((int)((unsigned char)src[0])) & 0xff, 65 ((int)((unsigned char)src[1])) & 0xff, 66 ((int)((unsigned char)src[2])) & 0xff, 67 ((int)((unsigned char)src[3])) & 0xff); 68 69 len = strlen(tmp); 70 if(len == 0 || len >= size) { 71 SET_ERRNO(ENOSPC); 72 return (NULL); 73 } 74 strcpy(dst, tmp); 75 return dst; 76} 77 78#ifdef ENABLE_IPV6 79/* 80 * Convert IPv6 binary address into presentation (printable) format. 81 */ 82static char *inet_ntop6 (const unsigned char *src, char *dst, size_t size) 83{ 84 /* 85 * Note that int32_t and int16_t need only be "at least" large enough 86 * to contain a value of the specified size. On some systems, like 87 * Crays, there is no such thing as an integer variable with 16 bits. 88 * Keep this in mind if you think this function should have been coded 89 * to use pointer overlays. All the world's not a VAX. 90 */ 91 char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")]; 92 char *tp; 93 struct { 94 long base; 95 long len; 96 } best, cur; 97 unsigned long words[IN6ADDRSZ / INT16SZ]; 98 int i; 99 100 /* Preprocess: 101 * Copy the input (bytewise) array into a wordwise array. 102 * Find the longest run of 0x00's in src[] for :: shorthanding. 103 */ 104 memset(words, '\0', sizeof(words)); 105 for(i = 0; i < IN6ADDRSZ; i++) 106 words[i/2] |= (src[i] << ((1 - (i % 2)) << 3)); 107 108 best.base = -1; 109 cur.base = -1; 110 best.len = 0; 111 cur.len = 0; 112 113 for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 114 if(words[i] == 0) { 115 if(cur.base == -1) 116 cur.base = i, cur.len = 1; 117 else 118 cur.len++; 119 } 120 else if(cur.base != -1) { 121 if(best.base == -1 || cur.len > best.len) 122 best = cur; 123 cur.base = -1; 124 } 125 } 126 if((cur.base != -1) && (best.base == -1 || cur.len > best.len)) 127 best = cur; 128 if(best.base != -1 && best.len < 2) 129 best.base = -1; 130 /* Format the result. */ 131 tp = tmp; 132 for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 133 /* Are we inside the best run of 0x00's? */ 134 if(best.base != -1 && i >= best.base && i < (best.base + best.len)) { 135 if(i == best.base) 136 *tp++ = ':'; 137 continue; 138 } 139 140 /* Are we following an initial run of 0x00s or any real hex? 141 */ 142 if(i != 0) 143 *tp++ = ':'; 144 145 /* Is this address an encapsulated IPv4? 146 */ 147 if(i == 6 && best.base == 0 && 148 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { 149 if(!inet_ntop4(src+12, tp, sizeof(tmp) - (tp - tmp))) { 150 SET_ERRNO(ENOSPC); 151 return (NULL); 152 } 153 tp += strlen(tp); 154 break; 155 } 156 tp += snprintf(tp, 5, "%lx", words[i]); 157 } 158 159 /* Was it a trailing run of 0x00's? 160 */ 161 if(best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) 162 *tp++ = ':'; 163 *tp++ = '\0'; 164 165 /* Check for overflow, copy, and we're done. 166 */ 167 if((size_t)(tp - tmp) > size) { 168 SET_ERRNO(ENOSPC); 169 return (NULL); 170 } 171 strcpy(dst, tmp); 172 return dst; 173} 174#endif /* ENABLE_IPV6 */ 175 176/* 177 * Convert a network format address to presentation format. 178 * 179 * Returns pointer to presentation format address (`buf'). 180 * Returns NULL on error and errno set with the specific 181 * error, EAFNOSUPPORT or ENOSPC. 182 * 183 * On Windows we store the error in the thread errno, not 184 * in the winsock error code. This is to avoid losing the 185 * actual last winsock error. So use macro ERRNO to fetch the 186 * errno this function sets when returning NULL, not SOCKERRNO. 187 */ 188char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size) 189{ 190 switch (af) { 191 case AF_INET: 192 return inet_ntop4((const unsigned char*)src, buf, size); 193#ifdef ENABLE_IPV6 194 case AF_INET6: 195 return inet_ntop6((const unsigned char*)src, buf, size); 196#endif 197 default: 198 SET_ERRNO(EAFNOSUPPORT); 199 return NULL; 200 } 201} 202#endif /* HAVE_INET_NTOP */ 203