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