1/* 2 * Copyright (c) 1996-1999 by 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 DISCLAIMS 9 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES 10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE 11 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 13 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 15 * SOFTWARE. 16 */ 17 18#include <errno.h> 19#include <sys/types.h> 20#include <sys/socket.h> 21#include <sys/socket.h> 22#include <netinet/in.h> 23#include <arpa/inet.h> 24#include <stdio.h> 25#include <string.h> 26 27#ifndef NS_INADDRSZ 28#define NS_INADDRSZ 4 29#endif 30#ifndef NS_IN6ADDRSZ 31#define NS_IN6ADDRSZ 16 32#endif 33#ifndef NS_INT16SZ 34#define NS_INT16SZ 2 35#endif 36 37/* 38 * WARNING: Don't even consider trying to compile this on a system where 39 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX. 40 */ 41 42/* const char * 43 * inet_ntop4(src, dst, size) 44 * format an IPv4 address 45 * return: 46 * `dst' (as a const) 47 * notes: 48 * (1) uses no statics 49 * (2) takes a u_char* not an in_addr as input 50 * author: 51 * Paul Vixie, 1996. 52 */ 53static const char * 54inet_ntop4(src, dst, size) 55 const u_char *src; 56 char *dst; 57 size_t size; 58{ 59 static const char fmt[] = "%u.%u.%u.%u"; 60 char tmp[sizeof "255.255.255.255"]; 61 int nprinted; 62 63 nprinted = snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]); 64 if (nprinted < 0) 65 return (NULL); /* we assume "errno" was set by "snprintf()" */ 66 if ((size_t)nprinted > size) { 67 errno = ENOSPC; 68 return (NULL); 69 } 70 strcpy(dst, tmp); 71 return (dst); 72} 73 74#ifndef NO_IPV6 75/* const char * 76 * inet_ntop6(src, dst, size) 77 * convert IPv6 binary address into presentation (printable) format 78 * author: 79 * Paul Vixie, 1996. 80 */ 81static const char * 82inet_ntop6(src, dst, size) 83 const u_char *src; 84 char *dst; 85 size_t size; 86{ 87 /* 88 * Note that int32_t and int16_t need only be "at least" large enough 89 * to contain a value of the specified size. On some systems, like 90 * Crays, there is no such thing as an integer variable with 16 bits. 91 * Keep this in mind if you think this function should have been coded 92 * to use pointer overlays. All the world's not a VAX. 93 */ 94 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp; 95 struct { int base, len; } best, cur; 96 unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ]; 97 int i; 98 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 < NS_IN6ADDRSZ; i++) 106 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); 107 best.base = -1; 108 cur.base = -1; 109 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { 110 if (words[i] == 0) { 111 if (cur.base == -1) 112 cur.base = i, cur.len = 1; 113 else 114 cur.len++; 115 } else { 116 if (cur.base != -1) { 117 if (best.base == -1 || cur.len > best.len) 118 best = cur; 119 cur.base = -1; 120 } 121 } 122 } 123 if (cur.base != -1) { 124 if (best.base == -1 || cur.len > best.len) 125 best = cur; 126 } 127 if (best.base != -1 && best.len < 2) 128 best.base = -1; 129 130 /* 131 * Format the result. 132 */ 133 tp = tmp; 134 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { 135 /* Are we inside the best run of 0x00's? */ 136 if (best.base != -1 && i >= best.base && 137 i < (best.base + best.len)) { 138 if (i == best.base) 139 *tp++ = ':'; 140 continue; 141 } 142 /* Are we following an initial run of 0x00s or any real hex? */ 143 if (i != 0) 144 *tp++ = ':'; 145 /* Is this address an encapsulated IPv4? */ 146 if (i == 6 && best.base == 0 && 147 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { 148 if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp))) 149 return (NULL); 150 tp += strlen(tp); 151 break; 152 } 153 tp += snprintf(tp, sizeof tmp - (tp - tmp), "%x", words[i]); 154 } 155 /* Was it a trailing run of 0x00's? */ 156 if (best.base != -1 && (best.base + best.len) == 157 (NS_IN6ADDRSZ / NS_INT16SZ)) 158 *tp++ = ':'; 159 *tp++ = '\0'; 160 161 /* 162 * Check for overflow, copy, and we're done. 163 */ 164 if ((size_t)(tp - tmp) > size) { 165 errno = ENOSPC; 166 return (NULL); 167 } 168 strcpy(dst, tmp); 169 return (dst); 170} 171#endif 172 173/* char * 174 * inet_ntop(af, src, dst, size) 175 * convert a network format address to presentation format. 176 * return: 177 * pointer to presentation format address (`dst'), or NULL (see errno). 178 * author: 179 * Paul Vixie, 1996. 180 */ 181const char * 182inet_ntop(af, src, dst, size) 183 int af; 184 const void *src; 185 char *dst; 186 size_t size; 187{ 188 switch (af) { 189 case AF_INET: 190 return (inet_ntop4(src, dst, size)); 191#ifndef NO_IPV6 192 case AF_INET6: 193 return (inet_ntop6(src, dst, size)); 194#endif 195 default: 196 errno = EAFNOSUPPORT; 197 return (NULL); 198 } 199 /* NOTREACHED */ 200}