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 19 #include "replace.h" 20 #include "system/network.h" 21 22 #define NS_INT16SZ 2 23 #define NS_IN6ADDRSZ 16 24 25 /* 26 * WARNING: Don't even consider trying to compile this on a system where 27 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX. 28 */ 29 30 static const char *inet_ntop4(const unsigned char *src, char *dst, 31 socklen_t size); rep_inet_ntoa(struct in_addr ip)32 33 #ifdef AF_INET6 34 static const char *inet_ntop6(const unsigned char *src, char *dst, 35 socklen_t size); 36 #endif 37 38 /* char * 39 * isc_net_ntop(af, src, dst, size) 40 * convert a network format address to presentation format. 41 * return: 42 * pointer to presentation format address (`dst'), or NULL (see errno). 43 * author: 44 * Paul Vixie, 1996. 45 */ 46 const char * 47 rep_inet_ntop(int af, const void *src, char *dst, socklen_t size) 48 { 49 switch (af) { 50 case AF_INET: 51 return (inet_ntop4(src, dst, size)); 52 #ifdef AF_INET6 53 case AF_INET6: 54 return (inet_ntop6(src, dst, size)); 55 #endif 56 default: 57 errno = EAFNOSUPPORT; 58 return (NULL); 59 } 60 /* NOTREACHED */ 61 } 62 63 /* const char * 64 * inet_ntop4(src, dst, size) 65 * format an IPv4 address 66 * return: 67 * `dst' (as a const) 68 * notes: 69 * (1) uses no statics 70 * (2) takes a unsigned char* not an in_addr as input 71 * author: 72 * Paul Vixie, 1996. 73 */ 74 static const char * 75 inet_ntop4(const unsigned char *src, char *dst, socklen_t size) 76 { 77 static const char *fmt = "%u.%u.%u.%u"; 78 char tmp[sizeof "255.255.255.255"]; 79 size_t len; 80 81 len = snprintf(tmp, sizeof tmp, fmt, src[0], src[1], src[2], src[3]); 82 if (len >= size) { 83 errno = ENOSPC; 84 return (NULL); 85 } 86 memcpy(dst, tmp, len + 1); 87 88 return (dst); 89 } 90 91 /* const char * 92 * isc_inet_ntop6(src, dst, size) 93 * convert IPv6 binary address into presentation (printable) format 94 * author: 95 * Paul Vixie, 1996. 96 */ 97 #ifdef AF_INET6 98 static const char * 99 inet_ntop6(const unsigned char *src, char *dst, socklen_t size) 100 { 101 /* 102 * Note that int32_t and int16_t need only be "at least" large enough 103 * to contain a value of the specified size. On some systems, like 104 * Crays, there is no such thing as an integer variable with 16 bits. 105 * Keep this in mind if you think this function should have been coded 106 * to use pointer overlays. All the world's not a VAX. 107 */ 108 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp; 109 struct { int base, len; } best, cur; 110 unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ]; 111 int i, inc; 112 113 /* 114 * Preprocess: 115 * Copy the input (bytewise) array into a wordwise array. 116 * Find the longest run of 0x00's in src[] for :: shorthanding. 117 */ 118 memset(words, '\0', sizeof words); 119 for (i = 0; i < NS_IN6ADDRSZ; i++) 120 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); 121 best.base = -1; 122 best.len = 0; 123 cur.base = -1; 124 cur.len = 0; 125 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { 126 if (words[i] == 0) { 127 if (cur.base == -1) 128 cur.base = i, cur.len = 1; 129 else 130 cur.len++; 131 } else { 132 if (cur.base != -1) { 133 if (best.base == -1 || cur.len > best.len) 134 best = cur; 135 cur.base = -1; 136 } 137 } 138 } 139 if (cur.base != -1) { 140 if (best.base == -1 || cur.len > best.len) 141 best = cur; 142 } 143 if (best.base != -1 && best.len < 2) 144 best.base = -1; 145 146 /* 147 * Format the result. 148 */ 149 tp = tmp; 150 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { 151 /* Are we inside the best run of 0x00's? */ 152 if (best.base != -1 && i >= best.base && 153 i < (best.base + best.len)) { 154 if (i == best.base) 155 *tp++ = ':'; 156 continue; 157 } 158 /* Are we following an initial run of 0x00s or any real hex? */ 159 if (i != 0) 160 *tp++ = ':'; 161 /* Is this address an encapsulated IPv4? */ 162 if (i == 6 && best.base == 0 && 163 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { 164 if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp))) 165 return (NULL); 166 tp += strlen(tp); 167 break; 168 } 169 inc = snprintf(tp, 5, "%x", words[i]); 170 if (inc >= 5) { 171 abort(); 172 } 173 tp += inc; 174 } 175 /* Was it a trailing run of 0x00's? */ 176 if (best.base != -1 && (best.base + best.len) == 177 (NS_IN6ADDRSZ / NS_INT16SZ)) 178 *tp++ = ':'; 179 *tp++ = '\0'; 180 181 /* 182 * Check for overflow, copy, and we're done. 183 */ 184 if ((size_t)(tp - tmp) > size) { 185 errno = ENOSPC; 186 return (NULL); 187 } 188 memcpy(dst, tmp, tp - tmp); 189 return (dst); 190 } 191 #endif /* AF_INET6 */ 192