1 /* 2 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6 /* 7 * Copyright (c) 1996 by Internet Software Consortium. 8 * 9 * Permission to use, copy, modify, and distribute this software for any 10 * purpose with or without fee is hereby granted, provided that the above 11 * copyright notice and this permission notice appear in all copies. 12 * 13 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS 14 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE 16 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL 17 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR 18 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS 19 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 20 * SOFTWARE. 21 */ 22 23 #pragma ident "%Z%%M% %I% %E% SMI" 24 25 #include <stdlib.h> 26 #include <ctype.h> 27 #include <string.h> 28 #include <strings.h> 29 #include <netdb.h> 30 #include <stdio.h> 31 #include <arpa/inet.h> 32 #include <netinet/in.h> 33 #include <sys/socket.h> 34 #include <errno.h> 35 36 static const char *inet_ntop4(const uchar_t *, char *, socklen_t); 37 static const char *inet_ntop6(const uchar_t *, char *, socklen_t); 38 39 /* 40 * char * 41 * inet_ntop(af, src, dst, size) 42 * convert a network format address to presentation format. 43 * return: 44 * pointer to presentation format address (`dst'), or NULL (see errno). 45 */ 46 const char * 47 inet_ntop(int af, const void *src, char *dst, socklen_t size) 48 { 49 switch (af) { 50 case AF_INET: 51 return (inet_ntop4(src, dst, size)); 52 case AF_INET6: 53 return (inet_ntop6(src, dst, size)); 54 default: 55 errno = EAFNOSUPPORT; 56 return (NULL); 57 } 58 /* NOTREACHED */ 59 } 60 61 /* 62 * const char * 63 * inet_ntop4(src, dst, size) 64 * format an IPv4 address, more or less like inet_ntoa() 65 * return: 66 * `dst' (as a const) 67 * notes: 68 * (1) uses no statics 69 * (2) takes a uchar_t* not an in_addr as input 70 */ 71 72 #ifdef SPRINTF_CHAR 73 /* CSTYLED */ 74 #define SPRINTF(x) strlen(sprintf/**/x) 75 #else 76 #define SPRINTF(x) ((size_t)sprintf x) 77 #endif 78 79 static const char * 80 inet_ntop4(const uchar_t *src, char *dst, socklen_t size) 81 { 82 static const char fmt[] = "%u.%u.%u.%u"; 83 char tmp[sizeof ("255.255.255.255")]; 84 85 if (SPRINTF((tmp, fmt, src[0], src[1], src[2], src[3])) > size) { 86 errno = ENOSPC; 87 return (NULL); 88 } 89 (void) strcpy(dst, tmp); 90 return (dst); 91 } 92 93 /* 94 * const char * 95 * inet_ntop6(src, dst, size) 96 * convert IPv6 binary address into presentation (printable) format 97 */ 98 #define INADDRSZ 4 99 #define IN6ADDRSZ 16 100 #define INT16SZ 2 101 static const char * 102 inet_ntop6(const uchar_t *src, char *dst, socklen_t size) 103 { 104 /* 105 * Note that int32_t and int16_t need only be "at least" large enough 106 * to contain a value of the specified size. On some systems, like 107 * Crays, there is no such thing as an integer variable with 16 bits. 108 * Keep this in mind if you think this function should have been coded 109 * to use pointer overlays. All the world's not a VAX. 110 */ 111 char tmp[sizeof ("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")], *tp; 112 struct { int base, len; } best, cur; 113 uint_t words[IN6ADDRSZ / INT16SZ]; 114 int i; 115 116 /* 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 (void) memset(words, '\0', sizeof (words)); 122 for (i = 0; i < IN6ADDRSZ; i++) 123 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); 124 best.base = -1; 125 cur.base = -1; 126 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 127 if (words[i] == 0) { 128 if (cur.base == -1) 129 cur.base = i, cur.len = 1; 130 else 131 cur.len++; 132 } else { 133 if (cur.base != -1) { 134 if (best.base == -1 || cur.len > best.len) 135 best = cur; 136 cur.base = -1; 137 } 138 } 139 } 140 if (cur.base != -1) { 141 if (best.base == -1 || cur.len > best.len) 142 best = cur; 143 } 144 if (best.base != -1 && best.len < 2) 145 best.base = -1; 146 147 /* 148 * Format the result. 149 */ 150 tp = tmp; 151 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 152 /* Are we inside the best run of 0x00's? */ 153 if (best.base != -1 && i >= best.base && 154 i < (best.base + best.len)) { 155 if (i == best.base) 156 *tp++ = ':'; 157 continue; 158 } 159 /* Are we following an initial run of 0x00s or any real hex? */ 160 if (i != 0) 161 *tp++ = ':'; 162 /* Is this address an encapsulated IPv4? */ 163 if (i == 6 && best.base == 0 && 164 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { 165 if (!inet_ntop4(src+12, tp, sizeof (tmp) - (tp - tmp))) 166 return (NULL); 167 tp += strlen(tp); 168 break; 169 } 170 tp += SPRINTF((tp, "%x", words[i])); 171 } 172 /* Was it a trailing run of 0x00's? */ 173 if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) 174 *tp++ = ':'; 175 *tp++ = '\0'; 176 177 /* 178 * Check for overflow, copy, and we're done. 179 */ 180 if ((int)(tp - tmp) > size) { 181 errno = ENOSPC; 182 return (NULL); 183 } 184 (void) strcpy(dst, tmp); 185 return (dst); 186 } 187