1 /* 2 * Copyright (c) 1996 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 /* 19 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 20 * Use is subject to license terms. 21 */ 22 23 #include "lint.h" 24 25 #include <sys/socket.h> 26 27 #include <arpa/inet.h> 28 #include <netinet/in.h> 29 30 #include <ctype.h> 31 #include <errno.h> 32 #include <netdb.h> 33 #include <stdio.h> 34 #include <stdlib.h> 35 #include <string.h> 36 #include <strings.h> 37 38 static const char *inet_ntop4(const uchar_t *, char *, socklen_t); 39 static const char *inet_ntop6(const uchar_t *, char *, socklen_t); 40 41 /* 42 * char * 43 * inet_ntop(af, src, dst, size) 44 * convert a network format address to presentation format. 45 * return: 46 * pointer to presentation format address (`dst'), or NULL (see errno). 47 */ 48 const char * 49 inet_ntop(int af, const void *src, char *dst, socklen_t size) 50 { 51 switch (af) { 52 case AF_INET: 53 return (inet_ntop4(src, dst, size)); 54 case AF_INET6: 55 return (inet_ntop6(src, dst, size)); 56 default: 57 errno = EAFNOSUPPORT; 58 return (NULL); 59 } 60 /* NOTREACHED */ 61 } 62 63 /* 64 * const char * 65 * inet_ntop4(src, dst, size) 66 * format an IPv4 address, more or less like inet_ntoa() 67 * return: 68 * `dst' (as a const) 69 * notes: 70 * (1) uses no statics 71 * (2) takes a uchar_t* not an in_addr as input 72 */ 73 74 static const char * 75 inet_ntop4(const uchar_t *src, char *dst, socklen_t size) 76 { 77 static const char fmt[] = "%u.%u.%u.%u"; 78 char tmp[sizeof ("255.255.255.255")]; 79 80 if (sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) > size) { 81 errno = ENOSPC; 82 return (NULL); 83 } 84 (void) strcpy(dst, tmp); 85 return (dst); 86 } 87 88 /* 89 * const char * 90 * inet_ntop6(src, dst, size) 91 * convert IPv6 binary address into presentation (printable) format 92 */ 93 #define INADDRSZ 4 94 #define IN6ADDRSZ 16 95 #define INT16SZ 2 96 static const char * 97 inet_ntop6(const uchar_t *src, char *dst, socklen_t size) 98 { 99 /* 100 * Note that int32_t and int16_t need only be "at least" large enough 101 * to contain a value of the specified size. On some systems, like 102 * Crays, there is no such thing as an integer variable with 16 bits. 103 * Keep this in mind if you think this function should have been coded 104 * to use pointer overlays. All the world's not a VAX. 105 */ 106 char tmp[sizeof ("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")], *tp; 107 struct { int base, len; } best, cur; 108 uint_t words[IN6ADDRSZ / INT16SZ]; 109 int i; 110 111 /* 112 * Preprocess: 113 * Copy the input (bytewise) array into a wordwise array. 114 * Find the longest run of 0x00's in src[] for :: shorthanding. 115 */ 116 (void) memset(words, '\0', sizeof (words)); 117 for (i = 0; i < IN6ADDRSZ; i++) 118 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); 119 best.base = -1; 120 cur.base = -1; 121 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 122 if (words[i] == 0) { 123 if (cur.base == -1) 124 cur.base = i, cur.len = 1; 125 else 126 cur.len++; 127 } else { 128 if (cur.base != -1) { 129 if (best.base == -1 || cur.len > best.len) 130 best = cur; 131 cur.base = -1; 132 } 133 } 134 } 135 if (cur.base != -1) { 136 if (best.base == -1 || cur.len > best.len) 137 best = cur; 138 } 139 if (best.base != -1 && best.len < 2) 140 best.base = -1; 141 142 /* 143 * Format the result. 144 */ 145 tp = tmp; 146 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { 147 /* Are we inside the best run of 0x00's? */ 148 if (best.base != -1 && i >= best.base && 149 i < (best.base + best.len)) { 150 if (i == best.base) 151 *tp++ = ':'; 152 continue; 153 } 154 /* Are we following an initial run of 0x00s or any real hex? */ 155 if (i != 0) 156 *tp++ = ':'; 157 /* Is this address an encapsulated IPv4? */ 158 if (i == 6 && best.base == 0 && 159 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { 160 if (!inet_ntop4(src+12, tp, sizeof (tmp) - (tp - tmp))) 161 return (NULL); 162 tp += strlen(tp); 163 break; 164 } 165 tp += sprintf(tp, "%x", words[i]); 166 } 167 /* Was it a trailing run of 0x00's? */ 168 if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) 169 *tp++ = ':'; 170 *tp++ = '\0'; 171 172 /* 173 * Check for overflow, copy, and we're done. 174 */ 175 if ((int)(tp - tmp) > size) { 176 errno = ENOSPC; 177 return (NULL); 178 } 179 (void) strcpy(dst, tmp); 180 return (dst); 181 } 182