1 | /* |
2 | * Copyright (C) 1996-2019 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 |
9 | * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL |
10 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL |
11 | * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, |
12 | * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING |
13 | * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, |
14 | * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION |
15 | * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
16 | */ |
17 | /* |
18 | * Original code by Paul Vixie. "curlified" by Gisle Vanem. |
19 | */ |
20 | |
21 | #include "curl_setup.h" |
22 | |
23 | #ifndef HAVE_INET_NTOP |
24 | |
25 | #ifdef HAVE_SYS_PARAM_H |
26 | #include <sys/param.h> |
27 | #endif |
28 | #ifdef HAVE_NETINET_IN_H |
29 | #include <netinet/in.h> |
30 | #endif |
31 | #ifdef HAVE_ARPA_INET_H |
32 | #include <arpa/inet.h> |
33 | #endif |
34 | |
35 | #include "inet_ntop.h" |
36 | #include "curl_printf.h" |
37 | |
38 | #define IN6ADDRSZ 16 |
39 | #define INADDRSZ 4 |
40 | #define INT16SZ 2 |
41 | |
42 | /* |
43 | * Format an IPv4 address, more or less like inet_ntoa(). |
44 | * |
45 | * Returns `dst' (as a const) |
46 | * Note: |
47 | * - uses no statics |
48 | * - takes a unsigned char* not an in_addr as input |
49 | */ |
50 | static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size) |
51 | { |
52 | char tmp[sizeof("255.255.255.255" )]; |
53 | size_t len; |
54 | |
55 | DEBUGASSERT(size >= 16); |
56 | |
57 | tmp[0] = '\0'; |
58 | (void)msnprintf(tmp, sizeof(tmp), "%d.%d.%d.%d" , |
59 | ((int)((unsigned char)src[0])) & 0xff, |
60 | ((int)((unsigned char)src[1])) & 0xff, |
61 | ((int)((unsigned char)src[2])) & 0xff, |
62 | ((int)((unsigned char)src[3])) & 0xff); |
63 | |
64 | len = strlen(tmp); |
65 | if(len == 0 || len >= size) { |
66 | errno = ENOSPC; |
67 | return (NULL); |
68 | } |
69 | strcpy(dst, tmp); |
70 | return dst; |
71 | } |
72 | |
73 | #ifdef ENABLE_IPV6 |
74 | /* |
75 | * Convert IPv6 binary address into presentation (printable) format. |
76 | */ |
77 | static char *inet_ntop6 (const unsigned char *src, char *dst, size_t size) |
78 | { |
79 | /* |
80 | * Note that int32_t and int16_t need only be "at least" large enough |
81 | * to contain a value of the specified size. On some systems, like |
82 | * Crays, there is no such thing as an integer variable with 16 bits. |
83 | * Keep this in mind if you think this function should have been coded |
84 | * to use pointer overlays. All the world's not a VAX. |
85 | */ |
86 | char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255" )]; |
87 | char *tp; |
88 | struct { |
89 | long base; |
90 | long len; |
91 | } best, cur; |
92 | unsigned long words[IN6ADDRSZ / INT16SZ]; |
93 | int i; |
94 | |
95 | /* Preprocess: |
96 | * Copy the input (bytewise) array into a wordwise array. |
97 | * Find the longest run of 0x00's in src[] for :: shorthanding. |
98 | */ |
99 | memset(words, '\0', sizeof(words)); |
100 | for(i = 0; i < IN6ADDRSZ; i++) |
101 | words[i/2] |= (src[i] << ((1 - (i % 2)) << 3)); |
102 | |
103 | best.base = -1; |
104 | cur.base = -1; |
105 | best.len = 0; |
106 | cur.len = 0; |
107 | |
108 | for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { |
109 | if(words[i] == 0) { |
110 | if(cur.base == -1) |
111 | cur.base = i, cur.len = 1; |
112 | else |
113 | cur.len++; |
114 | } |
115 | else if(cur.base != -1) { |
116 | if(best.base == -1 || cur.len > best.len) |
117 | best = cur; |
118 | cur.base = -1; |
119 | } |
120 | } |
121 | if((cur.base != -1) && (best.base == -1 || cur.len > best.len)) |
122 | best = cur; |
123 | if(best.base != -1 && best.len < 2) |
124 | best.base = -1; |
125 | /* Format the result. */ |
126 | tp = tmp; |
127 | for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { |
128 | /* Are we inside the best run of 0x00's? */ |
129 | if(best.base != -1 && i >= best.base && i < (best.base + best.len)) { |
130 | if(i == best.base) |
131 | *tp++ = ':'; |
132 | continue; |
133 | } |
134 | |
135 | /* Are we following an initial run of 0x00s or any real hex? |
136 | */ |
137 | if(i != 0) |
138 | *tp++ = ':'; |
139 | |
140 | /* Is this address an encapsulated IPv4? |
141 | */ |
142 | if(i == 6 && best.base == 0 && |
143 | (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { |
144 | if(!inet_ntop4(src + 12, tp, sizeof(tmp) - (tp - tmp))) { |
145 | errno = ENOSPC; |
146 | return (NULL); |
147 | } |
148 | tp += strlen(tp); |
149 | break; |
150 | } |
151 | tp += msnprintf(tp, 5, "%lx" , words[i]); |
152 | } |
153 | |
154 | /* Was it a trailing run of 0x00's? |
155 | */ |
156 | if(best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) |
157 | *tp++ = ':'; |
158 | *tp++ = '\0'; |
159 | |
160 | /* Check for overflow, copy, and we're done. |
161 | */ |
162 | if((size_t)(tp - tmp) > size) { |
163 | errno = ENOSPC; |
164 | return (NULL); |
165 | } |
166 | strcpy(dst, tmp); |
167 | return dst; |
168 | } |
169 | #endif /* ENABLE_IPV6 */ |
170 | |
171 | /* |
172 | * Convert a network format address to presentation format. |
173 | * |
174 | * Returns pointer to presentation format address (`buf'). |
175 | * Returns NULL on error and errno set with the specific |
176 | * error, EAFNOSUPPORT or ENOSPC. |
177 | * |
178 | * On Windows we store the error in the thread errno, not |
179 | * in the winsock error code. This is to avoid losing the |
180 | * actual last winsock error. So when this function returns |
181 | * NULL, check errno not SOCKERRNO. |
182 | */ |
183 | char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size) |
184 | { |
185 | switch(af) { |
186 | case AF_INET: |
187 | return inet_ntop4((const unsigned char *)src, buf, size); |
188 | #ifdef ENABLE_IPV6 |
189 | case AF_INET6: |
190 | return inet_ntop6((const unsigned char *)src, buf, size); |
191 | #endif |
192 | default: |
193 | errno = EAFNOSUPPORT; |
194 | return NULL; |
195 | } |
196 | } |
197 | #endif /* HAVE_INET_NTOP */ |
198 | |