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 "../git-compat-util.h" 19 20#ifndef NS_INADDRSZ 21#define NS_INADDRSZ 4 22#endif 23#ifndef NS_IN6ADDRSZ 24#define NS_IN6ADDRSZ 16 25#endif 26#ifndef NS_INT16SZ 27#define NS_INT16SZ 2 28#endif 29 30/* 31 * WARNING: Don't even consider trying to compile this on a system where 32 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX. 33 */ 34 35/* const char * 36 * inet_ntop4(src, dst, size) 37 * format an IPv4 address 38 * return: 39 * `dst' (as a const) 40 * notes: 41 * (1) uses no statics 42 * (2) takes a u_char* not an in_addr as input 43 * author: 44 * Paul Vixie, 1996. 45 */ 46static const char * 47inet_ntop4(const u_char *src, char *dst, size_t size) 48{ 49 static const char fmt[] = "%u.%u.%u.%u"; 50 char tmp[sizeof "255.255.255.255"]; 51 int nprinted; 52 53 nprinted = snprintf(tmp, sizeof(tmp), fmt, src[0], src[1], src[2], src[3]); 54 if (nprinted < 0) 55 return (NULL); /* we assume "errno" was set by "snprintf()" */ 56 if ((size_t)nprinted > size) { 57 errno = ENOSPC; 58 return (NULL); 59 } 60 strcpy(dst, tmp); 61 return (dst); 62} 63 64#ifndef NO_IPV6 65/* const char * 66 * inet_ntop6(src, dst, size) 67 * convert IPv6 binary address into presentation (printable) format 68 * author: 69 * Paul Vixie, 1996. 70 */ 71static const char * 72inet_ntop6(const u_char *src, char *dst, size_t size) 73{ 74 /* 75 * Note that int32_t and int16_t need only be "at least" large enough 76 * to contain a value of the specified size. On some systems, like 77 * Crays, there is no such thing as an integer variable with 16 bits. 78 * Keep this in mind if you think this function should have been coded 79 * to use pointer overlays. All the world's not a VAX. 80 */ 81 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp; 82 struct { int base, len; } best, cur; 83 unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ]; 84 int i; 85 86 /* 87 * Preprocess: 88 * Copy the input (bytewise) array into a wordwise array. 89 * Find the longest run of 0x00's in src[] for :: shorthanding. 90 */ 91 memset(words, '\0', sizeof words); 92 for (i = 0; i < NS_IN6ADDRSZ; i++) 93 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); 94 best.base = -1; 95 best.len = 0; 96 cur.base = -1; 97 cur.len = 0; 98 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { 99 if (words[i] == 0) { 100 if (cur.base == -1) 101 cur.base = i, cur.len = 1; 102 else 103 cur.len++; 104 } else { 105 if (cur.base != -1) { 106 if (best.base == -1 || cur.len > best.len) 107 best = cur; 108 cur.base = -1; 109 } 110 } 111 } 112 if (cur.base != -1) { 113 if (best.base == -1 || cur.len > best.len) 114 best = cur; 115 } 116 if (best.base != -1 && best.len < 2) 117 best.base = -1; 118 119 /* 120 * Format the result. 121 */ 122 tp = tmp; 123 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { 124 /* Are we inside the best run of 0x00's? */ 125 if (best.base != -1 && i >= best.base && 126 i < (best.base + best.len)) { 127 if (i == best.base) 128 *tp++ = ':'; 129 continue; 130 } 131 /* Are we following an initial run of 0x00s or any real hex? */ 132 if (i != 0) 133 *tp++ = ':'; 134 /* Is this address an encapsulated IPv4? */ 135 if (i == 6 && best.base == 0 && 136 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { 137 if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp))) 138 return (NULL); 139 tp += strlen(tp); 140 break; 141 } 142 tp += snprintf(tp, sizeof tmp - (tp - tmp), "%x", words[i]); 143 } 144 /* Was it a trailing run of 0x00's? */ 145 if (best.base != -1 && (best.base + best.len) == 146 (NS_IN6ADDRSZ / NS_INT16SZ)) 147 *tp++ = ':'; 148 *tp++ = '\0'; 149 150 /* 151 * Check for overflow, copy, and we're done. 152 */ 153 if ((size_t)(tp - tmp) > size) { 154 errno = ENOSPC; 155 return (NULL); 156 } 157 strcpy(dst, tmp); 158 return (dst); 159} 160#endif 161 162/* char * 163 * inet_ntop(af, src, dst, size) 164 * convert a network format address to presentation format. 165 * return: 166 * pointer to presentation format address (`dst'), or NULL (see errno). 167 * author: 168 * Paul Vixie, 1996. 169 */ 170const char * 171inet_ntop(int af, const void *src, char *dst, size_t size) 172{ 173 switch (af) { 174 case AF_INET: 175 return (inet_ntop4(src, dst, size)); 176#ifndef NO_IPV6 177 case AF_INET6: 178 return (inet_ntop6(src, dst, size)); 179#endif 180 default: 181 errno = EAFNOSUPPORT; 182 return (NULL); 183 } 184 /* NOTREACHED */ 185}