1 /* 2 * Copyright 2006 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 "mt.h" 26 #include <stdlib.h> 27 #include <ctype.h> 28 #include <string.h> 29 #include <strings.h> 30 #include <netdb.h> 31 #include <stdio.h> 32 #include <arpa/inet.h> 33 #include <netinet/in.h> 34 #include <sys/socket.h> 35 #include <errno.h> 36 37 static const char *inet_ntop4(const uchar_t *, char *, socklen_t); 38 static const char *inet_ntop6(const uchar_t *, char *, socklen_t); 39 40 /* 41 * char * 42 * inet_ntop(af, src, dst, size) 43 * convert a network format address to presentation format. 44 * return: 45 * pointer to presentation format address (`dst'), or NULL (see errno). 46 */ 47 const char * 48 inet_ntop(int af, const void *src, char *dst, socklen_t size) 49 { 50 switch (af) { 51 case AF_INET: 52 return (inet_ntop4(src, dst, size)); 53 case AF_INET6: 54 return (inet_ntop6(src, dst, size)); 55 default: 56 errno = EAFNOSUPPORT; 57 return (NULL); 58 } 59 /* NOTREACHED */ 60 } 61 62 /* 63 * const char * 64 * inet_ntop4(src, dst, size) 65 * format an IPv4 address, more or less like inet_ntoa() 66 * return: 67 * `dst' (as a const) 68 * notes: 69 * (1) uses no statics 70 * (2) takes a uchar_t* not an in_addr as input 71 */ 72 73 #ifdef SPRINTF_CHAR 74 /* CSTYLED */ 75 #define SPRINTF(x) strlen(sprintf/**/x) 76 #else 77 #define SPRINTF(x) ((size_t)sprintf x) 78 #endif 79 80 static const char * 81 inet_ntop4(const uchar_t *src, char *dst, socklen_t size) 82 { 83 static const char fmt[] = "%u.%u.%u.%u"; 84 char tmp[sizeof ("255.255.255.255")]; 85 86 if (SPRINTF((tmp, fmt, src[0], src[1], src[2], src[3])) > size) { 87 errno = ENOSPC; 88 return (NULL); 89 } 90 (void) strcpy(dst, tmp); 91 return (dst); 92 } 93 94 /* 95 * const char * 96 * inet_ntop6(src, dst, size) 97 * convert IPv6 binary address into presentation (printable) format 98 */ 99 #define INADDRSZ 4 100 #define IN6ADDRSZ 16 101 #define INT16SZ 2 102 static const char * 103 inet_ntop6(const uchar_t *src, char *dst, socklen_t size) 104 { 105 /* 106 * Note that int32_t and int16_t need only be "at least" large enough 107 * to contain a value of the specified size. On some systems, like 108 * Crays, there is no such thing as an integer variable with 16 bits. 109 * Keep this in mind if you think this function should have been coded 110 * to use pointer overlays. All the world's not a VAX. 111 */ 112 char tmp[sizeof ("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")], *tp; 113 struct { int base, len; } best, cur; 114 uint_t words[IN6ADDRSZ / INT16SZ]; 115 int i; 116 117 /* 118 * Preprocess: 119 * Copy the input (bytewise) array into a wordwise array. 120 * Find the longest run of 0x00's in src[] for :: shorthanding. 121 */ 122 (void) memset(words, '\0', sizeof (words)); 123 for (i = 0; i < IN6ADDRSZ; i++) 124 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); 125 best.base = -1; 126 cur.base = -1; 127 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 128 if (words[i] == 0) { 129 if (cur.base == -1) 130 cur.base = i, cur.len = 1; 131 else 132 cur.len++; 133 } else { 134 if (cur.base != -1) { 135 if (best.base == -1 || cur.len > best.len) 136 best = cur; 137 cur.base = -1; 138 } 139 } 140 } 141 if (cur.base != -1) { 142 if (best.base == -1 || cur.len > best.len) 143 best = cur; 144 } 145 if (best.base != -1 && best.len < 2) 146 best.base = -1; 147 148 /* 149 * Format the result. 150 */ 151 tp = tmp; 152 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 153 /* Are we inside the best run of 0x00's? */ 154 if (best.base != -1 && i >= best.base && 155 i < (best.base + best.len)) { 156 if (i == best.base) 157 *tp++ = ':'; 158 continue; 159 } 160 /* Are we following an initial run of 0x00s or any real hex? */ 161 if (i != 0) 162 *tp++ = ':'; 163 /* Is this address an encapsulated IPv4? */ 164 if (i == 6 && best.base == 0 && 165 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { 166 if (!inet_ntop4(src+12, tp, sizeof (tmp) - (tp - tmp))) 167 return (NULL); 168 tp += strlen(tp); 169 break; 170 } 171 tp += SPRINTF((tp, "%x", words[i])); 172 } 173 /* Was it a trailing run of 0x00's? */ 174 if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) 175 *tp++ = ':'; 176 *tp++ = '\0'; 177 178 /* 179 * Check for overflow, copy, and we're done. 180 */ 181 if ((int)(tp - tmp) > size) { 182 errno = ENOSPC; 183 return (NULL); 184 } 185 (void) strcpy(dst, tmp); 186 return (dst); 187 } 188