1 /* 2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (c) 1996,1999 by Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #if defined(LIBC_SCCS) && !defined(lint) 19 static const char rcsid[] = "$Id: inet_net_ntop.c,v 1.5 2006/06/20 02:50:14 marka Exp $"; 20 #endif 21 22 #include "port_before.h" 23 24 #include <sys/types.h> 25 #include <sys/socket.h> 26 #include <netinet/in.h> 27 #include <arpa/inet.h> 28 29 #include <errno.h> 30 #include <stdio.h> 31 #include <string.h> 32 #include <stdlib.h> 33 #include <limits.h> 34 35 #include "port_after.h" 36 37 #ifdef SPRINTF_CHAR 38 # define SPRINTF(x) strlen(sprintf/**/x) 39 #else 40 # define SPRINTF(x) ((size_t)sprintf x) 41 #endif 42 43 static char * inet_net_ntop_ipv4 __P((const u_char *src, int bits, 44 char *dst, size_t size)); 45 static char * inet_net_ntop_ipv6 __P((const u_char *src, int bits, 46 char *dst, size_t size)); 47 48 /*% 49 * char * 50 * inet_net_ntop(af, src, bits, dst, size) 51 * convert network number from network to presentation format. 52 * generates CIDR style result always. 53 * return: 54 * pointer to dst, or NULL if an error occurred (check errno). 55 * author: 56 * Paul Vixie (ISC), July 1996 57 */ 58 char * 59 inet_net_ntop(af, src, bits, dst, size) 60 int af; 61 const void *src; 62 int bits; 63 char *dst; 64 size_t size; 65 { 66 switch (af) { 67 case AF_INET: 68 return (inet_net_ntop_ipv4(src, bits, dst, size)); 69 case AF_INET6: 70 return (inet_net_ntop_ipv6(src, bits, dst, size)); 71 default: 72 errno = EAFNOSUPPORT; 73 return (NULL); 74 } 75 } 76 77 /*% 78 * static char * 79 * inet_net_ntop_ipv4(src, bits, dst, size) 80 * convert IPv4 network number from network to presentation format. 81 * generates CIDR style result always. 82 * return: 83 * pointer to dst, or NULL if an error occurred (check errno). 84 * note: 85 * network byte order assumed. this means 192.5.5.240/28 has 86 * 0b11110000 in its fourth octet. 87 * author: 88 * Paul Vixie (ISC), July 1996 89 */ 90 static char * 91 inet_net_ntop_ipv4(src, bits, dst, size) 92 const u_char *src; 93 int bits; 94 char *dst; 95 size_t size; 96 { 97 char *odst = dst; 98 char *t; 99 u_int m; 100 int b; 101 102 if (bits < 0 || bits > 32) { 103 errno = EINVAL; 104 return (NULL); 105 } 106 107 if (bits == 0) { 108 if (size < sizeof "0") 109 goto emsgsize; 110 *dst++ = '0'; 111 size--; 112 *dst = '\0'; 113 } 114 115 /* Format whole octets. */ 116 for (b = bits / 8; b > 0; b--) { 117 if (size <= sizeof "255.") 118 goto emsgsize; 119 t = dst; 120 dst += SPRINTF((dst, "%u", *src++)); 121 if (b > 1) { 122 *dst++ = '.'; 123 *dst = '\0'; 124 } 125 size -= (size_t)(dst - t); 126 } 127 128 /* Format partial octet. */ 129 b = bits % 8; 130 if (b > 0) { 131 if (size <= sizeof ".255") 132 goto emsgsize; 133 t = dst; 134 if (dst != odst) 135 *dst++ = '.'; 136 m = ((1 << b) - 1) << (8 - b); 137 dst += SPRINTF((dst, "%u", *src & m)); 138 size -= (size_t)(dst - t); 139 } 140 141 /* Format CIDR /width. */ 142 if (size <= sizeof "/32") 143 goto emsgsize; 144 dst += SPRINTF((dst, "/%u", bits)); 145 return (odst); 146 147 emsgsize: 148 errno = EMSGSIZE; 149 return (NULL); 150 } 151 152 /*% 153 * static char * 154 * inet_net_ntop_ipv6(src, bits, fakebits, dst, size) 155 * convert IPv6 network number from network to presentation format. 156 * generates CIDR style result always. Picks the shortest representation 157 * unless the IP is really IPv4. 158 * always prints specified number of bits (bits). 159 * return: 160 * pointer to dst, or NULL if an error occurred (check errno). 161 * note: 162 * network byte order assumed. this means 192.5.5.240/28 has 163 * 0x11110000 in its fourth octet. 164 * author: 165 * Vadim Kogan (UCB), June 2001 166 * Original version (IPv4) by Paul Vixie (ISC), July 1996 167 */ 168 169 static char * 170 inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size) { 171 u_int m; 172 int b; 173 int p; 174 int zero_s, zero_l, tmp_zero_s, tmp_zero_l; 175 int i; 176 int is_ipv4 = 0; 177 unsigned char inbuf[16]; 178 char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")]; 179 char *cp; 180 int words; 181 u_char *s; 182 183 if (bits < 0 || bits > 128) { 184 errno = EINVAL; 185 return (NULL); 186 } 187 188 cp = outbuf; 189 190 if (bits == 0) { 191 *cp++ = ':'; 192 *cp++ = ':'; 193 *cp = '\0'; 194 } else { 195 /* Copy src to private buffer. Zero host part. */ 196 p = (bits + 7) / 8; 197 memcpy(inbuf, src, p); 198 memset(inbuf + p, 0, 16 - p); 199 b = bits % 8; 200 if (b != 0) { 201 m = UINT_MAX << (8 - b); 202 inbuf[p-1] &= m; 203 } 204 205 s = inbuf; 206 207 /* how many words need to be displayed in output */ 208 words = (bits + 15) / 16; 209 if (words == 1) 210 words = 2; 211 212 /* Find the longest substring of zero's */ 213 zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0; 214 for (i = 0; i < (words * 2); i += 2) { 215 if ((s[i] | s[i+1]) == 0) { 216 if (tmp_zero_l == 0) 217 tmp_zero_s = i / 2; 218 tmp_zero_l++; 219 } else { 220 if (tmp_zero_l && zero_l < tmp_zero_l) { 221 zero_s = tmp_zero_s; 222 zero_l = tmp_zero_l; 223 tmp_zero_l = 0; 224 } 225 } 226 } 227 228 if (tmp_zero_l && zero_l < tmp_zero_l) { 229 zero_s = tmp_zero_s; 230 zero_l = tmp_zero_l; 231 } 232 233 if (zero_l != words && zero_s == 0 && ((zero_l == 6) || 234 ((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) || 235 ((zero_l == 7 && s[14] != 0 && s[15] != 1))))) 236 is_ipv4 = 1; 237 238 /* Format whole words. */ 239 for (p = 0; p < words; p++) { 240 if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l) { 241 /* Time to skip some zeros */ 242 if (p == zero_s) 243 *cp++ = ':'; 244 if (p == words - 1) 245 *cp++ = ':'; 246 s++; 247 s++; 248 continue; 249 } 250 251 if (is_ipv4 && p > 5 ) { 252 *cp++ = (p == 6) ? ':' : '.'; 253 cp += SPRINTF((cp, "%u", *s++)); 254 /* we can potentially drop the last octet */ 255 if (p != 7 || bits > 120) { 256 *cp++ = '.'; 257 cp += SPRINTF((cp, "%u", *s++)); 258 } 259 } else { 260 if (cp != outbuf) 261 *cp++ = ':'; 262 cp += SPRINTF((cp, "%x", *s * 256 + s[1])); 263 s += 2; 264 } 265 } 266 } 267 /* Format CIDR /width. */ 268 sprintf(cp, "/%u", bits); 269 if (strlen(outbuf) + 1 > size) 270 goto emsgsize; 271 strcpy(dst, outbuf); 272 273 return (dst); 274 275 emsgsize: 276 errno = EMSGSIZE; 277 return (NULL); 278 } 279 280 /*! \file */ 281