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 <sys/cdefs.h> 19 #if defined(LIBC_SCCS) && !defined(lint) 20 #ifdef notdef 21 static const char rcsid[] = "Id: inet_net_ntop.c,v 1.1.2.1 2002/08/02 02:17:21 marka Exp "; 22 #else 23 __RCSID("$NetBSD: inet_net_ntop.c,v 1.4 2017/05/09 02:56:44 maya Exp $"); 24 #endif 25 #endif 26 27 #include "port_before.h" 28 29 #include <sys/types.h> 30 #include <sys/socket.h> 31 #include <netinet/in.h> 32 #include <arpa/inet.h> 33 34 #include <errno.h> 35 #include <stdio.h> 36 #include <string.h> 37 #include <stdlib.h> 38 39 #include "port_after.h" 40 41 #ifdef __weak_alias 42 __weak_alias(inet_net_ntop,_inet_net_ntop) 43 #endif 44 45 #ifdef SPRINTF_CHAR 46 # define SPRINTF(x) strlen(sprintf/**/x) 47 #else 48 # define SPRINTF(x) sprintf x 49 #endif 50 51 static char * inet_net_ntop_ipv4(const u_char *src, int bits, 52 char *dst, size_t size); 53 static char * inet_net_ntop_ipv6(const u_char *src, int bits, 54 char *dst, size_t size); 55 56 /* 57 * char * 58 * inet_net_ntop(af, src, bits, dst, size) 59 * convert network number from network to presentation format. 60 * generates CIDR style result always. 61 * return: 62 * pointer to dst, or NULL if an error occurred (check errno). 63 * author: 64 * Paul Vixie (ISC), July 1996 65 */ 66 char * 67 inet_net_ntop(int af, const void *src, int bits, char *dst, size_t size) 68 { 69 switch (af) { 70 case AF_INET: 71 return (inet_net_ntop_ipv4(src, bits, dst, size)); 72 case AF_INET6: 73 return (inet_net_ntop_ipv6(src, bits, dst, size)); 74 default: 75 errno = EAFNOSUPPORT; 76 return (NULL); 77 } 78 } 79 80 /* 81 * static char * 82 * inet_net_ntop_ipv4(src, bits, dst, size) 83 * convert IPv4 network number from network to presentation format. 84 * generates CIDR style result always. 85 * return: 86 * pointer to dst, or NULL if an error occurred (check errno). 87 * note: 88 * network byte order assumed. this means 192.5.5.240/28 has 89 * 0b11110000 in its fourth octet. 90 * author: 91 * Paul Vixie (ISC), July 1996 92 */ 93 static char * 94 inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size) 95 { 96 char *odst = dst; 97 char *t; 98 u_int m; 99 int b; 100 101 if (bits < 0 || bits > 32) { 102 errno = EINVAL; 103 return (NULL); 104 } 105 106 if (bits == 0) { 107 if (size < sizeof "0") 108 goto emsgsize; 109 *dst++ = '0'; 110 size--; 111 *dst = '\0'; 112 } 113 114 /* Format whole octets. */ 115 for (b = bits / 8; b > 0; b--) { 116 if (size <= sizeof "255.") 117 goto emsgsize; 118 t = dst; 119 dst += SPRINTF((dst, "%u", *src++)); 120 if (b > 1) { 121 *dst++ = '.'; 122 *dst = '\0'; 123 } 124 size -= (size_t)(dst - t); 125 } 126 127 /* Format partial octet. */ 128 b = bits % 8; 129 if (b > 0) { 130 if (size <= sizeof ".255") 131 goto emsgsize; 132 t = dst; 133 if (dst != odst) 134 *dst++ = '.'; 135 m = ((1 << b) - 1) << (8 - b); 136 dst += SPRINTF((dst, "%u", *src & m)); 137 size -= (size_t)(dst - t); 138 } 139 140 /* Format CIDR /width. */ 141 if (size <= sizeof "/32") 142 goto emsgsize; 143 dst += SPRINTF((dst, "/%u", bits)); 144 return (odst); 145 146 emsgsize: 147 errno = EMSGSIZE; 148 return (NULL); 149 } 150 151 /* 152 * static char * 153 * inet_net_ntop_ipv6(src, bits, fakebits, dst, size) 154 * convert IPv6 network number from network to presentation format. 155 * generates CIDR style result always. Picks the shortest representation 156 * unless the IP is really IPv4. 157 * always prints specified number of bits (bits). 158 * return: 159 * pointer to dst, or NULL if an error occurred (check errno). 160 * note: 161 * network byte order assumed. this means 192.5.5.240/28 has 162 * 0x11110000 in its fourth octet. 163 * author: 164 * Vadim Kogan (UCB), June 2001 165 * Original version (IPv4) by Paul Vixie (ISC), July 1996 166 */ 167 168 static char * 169 inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size) 170 { 171 u_int m; 172 int b; 173 size_t p; 174 size_t zero_s, zero_l, tmp_zero_s, tmp_zero_l; 175 size_t 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 size_t 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 = ~0u << (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 (void)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 #undef inet_net_ntop 281 #pragma weak inet_net_ntop = __inet_net_ntop 282