1 /* 2 * Copyright (c) 1999 Kungliga Tekniska H�gskolan 3 * (Royal Institute of Technology, Stockholm, Sweden). 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the Kungliga Tekniska 20 * H�gskolan and its contributors. 21 * 22 * 4. Neither the name of the Institute nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #ifdef HAVE_CONFIG_H 40 #include "config.h" 41 #endif 42 43 #include <tcpdump-stdinc.h> 44 45 #include <stdio.h> 46 47 /* 48 * 49 */ 50 51 #ifndef IN6ADDRSZ 52 #define IN6ADDRSZ 16 /* IPv6 T_AAAA */ 53 #endif 54 55 #ifndef INT16SZ 56 #define INT16SZ 2 /* word size */ 57 #endif 58 59 static const char * 60 inet_ntop_v4 (const void *src, char *dst, size_t size) 61 { 62 const char digits[] = "0123456789"; 63 int i; 64 struct in_addr *addr = (struct in_addr *)src; 65 u_long a = ntohl(addr->s_addr); 66 const char *orig_dst = dst; 67 68 if (size < INET_ADDRSTRLEN) { 69 errno = ENOSPC; 70 return NULL; 71 } 72 for (i = 0; i < 4; ++i) { 73 int n = (a >> (24 - i * 8)) & 0xFF; 74 int non_zerop = 0; 75 76 if (non_zerop || n / 100 > 0) { 77 *dst++ = digits[n / 100]; 78 n %= 100; 79 non_zerop = 1; 80 } 81 if (non_zerop || n / 10 > 0) { 82 *dst++ = digits[n / 10]; 83 n %= 10; 84 non_zerop = 1; 85 } 86 *dst++ = digits[n]; 87 if (i != 3) 88 *dst++ = '.'; 89 } 90 *dst++ = '\0'; 91 return orig_dst; 92 } 93 94 #ifdef INET6 95 /* 96 * Convert IPv6 binary address into presentation (printable) format. 97 */ 98 static const char * 99 inet_ntop_v6 (const u_char *src, char *dst, size_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 [INET6_ADDRSTRLEN+1]; 109 char *tp; 110 struct { 111 long base; 112 long len; 113 } best, cur; 114 u_long words [IN6ADDRSZ / INT16SZ]; 115 int i; 116 117 /* Preprocess: 118 * Copy the input (bytewise) array into a wordwise array. 119 * Find the longest run of 0x00's in src[] for :: shorthanding. 120 */ 121 memset (words, 0, sizeof(words)); 122 for (i = 0; i < IN6ADDRSZ; i++) 123 words[i/2] |= (src[i] << ((1 - (i % 2)) << 3)); 124 125 best.len = 0; 126 best.base = -1; 127 cur.len = 0; 128 cur.base = -1; 129 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) 130 { 131 if (words[i] == 0) 132 { 133 if (cur.base == -1) 134 cur.base = i, cur.len = 1; 135 else cur.len++; 136 } 137 else if (cur.base != -1) 138 { 139 if (best.base == -1 || cur.len > best.len) 140 best = cur; 141 cur.base = -1; 142 } 143 } 144 if ((cur.base != -1) && (best.base == -1 || cur.len > best.len)) 145 best = cur; 146 if (best.base != -1 && best.len < 2) 147 best.base = -1; 148 149 /* Format the result. 150 */ 151 tp = tmp; 152 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) 153 { 154 /* Are we inside the best run of 0x00's? 155 */ 156 if (best.base != -1 && i >= best.base && i < (best.base + best.len)) 157 { 158 if (i == best.base) 159 *tp++ = ':'; 160 continue; 161 } 162 163 /* Are we following an initial run of 0x00s or any real hex? 164 */ 165 if (i != 0) 166 *tp++ = ':'; 167 168 /* Is this address an encapsulated IPv4? 169 */ 170 if (i == 6 && best.base == 0 && 171 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) 172 { 173 if (!inet_ntop_v4(src+12, tp, sizeof(tmp) - (tp - tmp))) 174 { 175 errno = ENOSPC; 176 return (NULL); 177 } 178 tp += strlen(tp); 179 break; 180 } 181 tp += sprintf (tp, "%lx", words[i]); 182 } 183 184 /* Was it a trailing run of 0x00's? 185 */ 186 if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) 187 *tp++ = ':'; 188 *tp++ = '\0'; 189 190 /* Check for overflow, copy, and we're done. 191 */ 192 if ((size_t)(tp - tmp) > size) 193 { 194 errno = ENOSPC; 195 return (NULL); 196 } 197 return strcpy (dst, tmp); 198 } 199 #endif /* INET6 */ 200 201 202 const char * 203 inet_ntop(int af, const void *src, char *dst, size_t size) 204 { 205 switch (af) { 206 case AF_INET : 207 return inet_ntop_v4 (src, dst, size); 208 #ifdef INET6 209 case AF_INET6: 210 return inet_ntop_v6 ((const u_char*)src, dst, size); 211 #endif 212 default : 213 errno = EAFNOSUPPORT; 214 return NULL; 215 } 216 } 217