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#include <string.h> 38#include <errno.h> 39 40#define _MPRINTF_REPLACE /* use our functions only */ 41#include <curl/mprintf.h> 42 43#include "inet_ntop.h" 44 45#define IN6ADDRSZ 16 46#define INADDRSZ 4 47#define INT16SZ 2 48 49/* 50 * Format an IPv4 address, more or less like inet_ntoa(). 51 * 52 * Returns `dst' (as a const) 53 * Note: 54 * - uses no statics 55 * - takes a unsigned char* not an in_addr as input 56 */ 57static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size) 58{ 59 char tmp[sizeof "255.255.255.255"]; 60 size_t len; 61 62 DEBUGASSERT(size >= 16); 63 64 tmp[0] = '\0'; 65 (void)snprintf(tmp, sizeof(tmp), "%d.%d.%d.%d", 66 ((int)((unsigned char)src[0])) & 0xff, 67 ((int)((unsigned char)src[1])) & 0xff, 68 ((int)((unsigned char)src[2])) & 0xff, 69 ((int)((unsigned char)src[3])) & 0xff); 70 71 len = strlen(tmp); 72 if(len == 0 || len >= size) { 73 SET_ERRNO(ENOSPC); 74 return (NULL); 75 } 76 strcpy(dst, tmp); 77 return dst; 78} 79 80#ifdef ENABLE_IPV6 81/* 82 * Convert IPv6 binary address into presentation (printable) format. 83 */ 84static char *inet_ntop6 (const unsigned char *src, char *dst, size_t size) 85{ 86 /* 87 * Note that int32_t and int16_t need only be "at least" large enough 88 * to contain a value of the specified size. On some systems, like 89 * Crays, there is no such thing as an integer variable with 16 bits. 90 * Keep this in mind if you think this function should have been coded 91 * to use pointer overlays. All the world's not a VAX. 92 */ 93 char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")]; 94 char *tp; 95 struct { 96 long base; 97 long len; 98 } best, cur; 99 unsigned long words[IN6ADDRSZ / INT16SZ]; 100 int i; 101 102 /* Preprocess: 103 * Copy the input (bytewise) array into a wordwise array. 104 * Find the longest run of 0x00's in src[] for :: shorthanding. 105 */ 106 memset(words, '\0', sizeof(words)); 107 for(i = 0; i < IN6ADDRSZ; i++) 108 words[i/2] |= (src[i] << ((1 - (i % 2)) << 3)); 109 110 best.base = -1; 111 cur.base = -1; 112 best.len = 0; 113 cur.len = 0; 114 115 for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 116 if(words[i] == 0) { 117 if(cur.base == -1) 118 cur.base = i, cur.len = 1; 119 else 120 cur.len++; 121 } 122 else if(cur.base != -1) { 123 if(best.base == -1 || cur.len > best.len) 124 best = cur; 125 cur.base = -1; 126 } 127 } 128 if((cur.base != -1) && (best.base == -1 || cur.len > best.len)) 129 best = cur; 130 if(best.base != -1 && best.len < 2) 131 best.base = -1; 132 /* Format the result. */ 133 tp = tmp; 134 for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 135 /* Are we inside the best run of 0x00's? */ 136 if(best.base != -1 && i >= best.base && i < (best.base + best.len)) { 137 if(i == best.base) 138 *tp++ = ':'; 139 continue; 140 } 141 142 /* Are we following an initial run of 0x00s or any real hex? 143 */ 144 if(i != 0) 145 *tp++ = ':'; 146 147 /* Is this address an encapsulated IPv4? 148 */ 149 if(i == 6 && best.base == 0 && 150 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { 151 if(!inet_ntop4(src+12, tp, sizeof(tmp) - (tp - tmp))) { 152 SET_ERRNO(ENOSPC); 153 return (NULL); 154 } 155 tp += strlen(tp); 156 break; 157 } 158 tp += snprintf(tp, 5, "%lx", words[i]); 159 } 160 161 /* Was it a trailing run of 0x00's? 162 */ 163 if(best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) 164 *tp++ = ':'; 165 *tp++ = '\0'; 166 167 /* Check for overflow, copy, and we're done. 168 */ 169 if((size_t)(tp - tmp) > size) { 170 SET_ERRNO(ENOSPC); 171 return (NULL); 172 } 173 strcpy(dst, tmp); 174 return dst; 175} 176#endif /* ENABLE_IPV6 */ 177 178/* 179 * Convert a network format address to presentation format. 180 * 181 * Returns pointer to presentation format address (`buf'). 182 * Returns NULL on error and errno set with the specific 183 * error, EAFNOSUPPORT or ENOSPC. 184 * 185 * On Windows we store the error in the thread errno, not 186 * in the winsock error code. This is to avoid losing the 187 * actual last winsock error. So use macro ERRNO to fetch the 188 * errno this function sets when returning NULL, not SOCKERRNO. 189 */ 190char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size) 191{ 192 switch (af) { 193 case AF_INET: 194 return inet_ntop4((const unsigned char*)src, buf, size); 195#ifdef ENABLE_IPV6 196 case AF_INET6: 197 return inet_ntop6((const unsigned char*)src, buf, size); 198#endif 199 default: 200 SET_ERRNO(EAFNOSUPPORT); 201 return NULL; 202 } 203} 204#endif /* HAVE_INET_NTOP */ 205