1 /*
2 * Copyright (C) 1996-2001 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 "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_SYS_SOCKET_H
29 #include <sys/socket.h>
30 #endif
31 #ifdef HAVE_NETINET_IN_H
32 #include <netinet/in.h>
33 #endif
34 #ifdef HAVE_ARPA_INET_H
35 #include <arpa/inet.h>
36 #endif
37 #include <string.h>
38 #include <errno.h>
39
40 #define _MPRINTF_REPLACE /* use our functions only */
41 #include <curl/mprintf.h>
42
43 #include "inet_ntop.h"
44
45 #define IN6ADDRSZ 16
46 #define INADDRSZ 4
47 #define INT16SZ 2
48
49 /*
50 * Format an IPv4 address, more or less like inet_ntoa().
51 *
52 * Returns `dst' (as a const)
53 * Note:
54 * - uses no statics
55 * - takes a unsigned char* not an in_addr as input
56 */
inet_ntop4(const unsigned char * src,char * dst,size_t size)57 static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size)
58 {
59 char tmp[sizeof "255.255.255.255"];
60 size_t len;
61
62 DEBUGASSERT(size >= 16);
63
64 tmp[0] = '\0';
65 (void)snprintf(tmp, sizeof(tmp), "%d.%d.%d.%d",
66 ((int)((unsigned char)src[0])) & 0xff,
67 ((int)((unsigned char)src[1])) & 0xff,
68 ((int)((unsigned char)src[2])) & 0xff,
69 ((int)((unsigned char)src[3])) & 0xff);
70
71 len = strlen(tmp);
72 if(len == 0 || len >= size)
73 {
74 SET_ERRNO(ENOSPC);
75 return (NULL);
76 }
77 strcpy(dst, tmp);
78 return dst;
79 }
80
81 #ifdef ENABLE_IPV6
82 /*
83 * Convert IPv6 binary address into presentation (printable) format.
84 */
inet_ntop6(const unsigned char * src,char * dst,size_t size)85 static char *inet_ntop6 (const unsigned char *src, char *dst, size_t size)
86 {
87 /*
88 * Note that int32_t and int16_t need only be "at least" large enough
89 * to contain a value of the specified size. On some systems, like
90 * Crays, there is no such thing as an integer variable with 16 bits.
91 * Keep this in mind if you think this function should have been coded
92 * to use pointer overlays. All the world's not a VAX.
93 */
94 char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")];
95 char *tp;
96 struct {
97 long base;
98 long len;
99 } best, cur;
100 unsigned long words[IN6ADDRSZ / INT16SZ];
101 int i;
102
103 /* Preprocess:
104 * Copy the input (bytewise) array into a wordwise array.
105 * Find the longest run of 0x00's in src[] for :: shorthanding.
106 */
107 memset(words, '\0', sizeof(words));
108 for (i = 0; i < IN6ADDRSZ; i++)
109 words[i/2] |= (src[i] << ((1 - (i % 2)) << 3));
110
111 best.base = -1;
112 cur.base = -1;
113 best.len = 0;
114 cur.len = 0;
115
116 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++)
117 {
118 if(words[i] == 0)
119 {
120 if(cur.base == -1)
121 cur.base = i, cur.len = 1;
122 else
123 cur.len++;
124 }
125 else if(cur.base != -1)
126 {
127 if(best.base == -1 || cur.len > best.len)
128 best = cur;
129 cur.base = -1;
130 }
131 }
132 if((cur.base != -1) && (best.base == -1 || cur.len > best.len))
133 best = cur;
134 if(best.base != -1 && best.len < 2)
135 best.base = -1;
136
137 /* Format the result.
138 */
139 tp = tmp;
140 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++)
141 {
142 /* Are we inside the best run of 0x00's?
143 */
144 if(best.base != -1 && i >= best.base && i < (best.base + best.len))
145 {
146 if(i == best.base)
147 *tp++ = ':';
148 continue;
149 }
150
151 /* Are we following an initial run of 0x00s or any real hex?
152 */
153 if(i != 0)
154 *tp++ = ':';
155
156 /* Is this address an encapsulated IPv4?
157 */
158 if(i == 6 && best.base == 0 &&
159 (best.len == 6 || (best.len == 5 && words[5] == 0xffff)))
160 {
161 if(!inet_ntop4(src+12, tp, sizeof(tmp) - (tp - tmp)))
162 {
163 SET_ERRNO(ENOSPC);
164 return (NULL);
165 }
166 tp += strlen(tp);
167 break;
168 }
169 tp += snprintf(tp, 5, "%lx", words[i]);
170 }
171
172 /* Was it a trailing run of 0x00's?
173 */
174 if(best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
175 *tp++ = ':';
176 *tp++ = '\0';
177
178 /* Check for overflow, copy, and we're done.
179 */
180 if((size_t)(tp - tmp) > size)
181 {
182 SET_ERRNO(ENOSPC);
183 return (NULL);
184 }
185 strcpy(dst, tmp);
186 return dst;
187 }
188 #endif /* ENABLE_IPV6 */
189
190 /*
191 * Convert a network format address to presentation format.
192 *
193 * Returns pointer to presentation format address (`buf').
194 * Returns NULL on error and errno set with the specific
195 * error, EAFNOSUPPORT or ENOSPC.
196 *
197 * On Windows we store the error in the thread errno, not
198 * in the winsock error code. This is to avoid loosing the
199 * actual last winsock error. So use macro ERRNO to fetch the
200 * errno this funtion sets when returning NULL, not SOCKERRNO.
201 */
Curl_inet_ntop(int af,const void * src,char * buf,size_t size)202 char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size)
203 {
204 switch (af) {
205 case AF_INET:
206 return inet_ntop4((const unsigned char*)src, buf, size);
207 #ifdef ENABLE_IPV6
208 case AF_INET6:
209 return inet_ntop6((const unsigned char*)src, buf, size);
210 #endif
211 default:
212 SET_ERRNO(EAFNOSUPPORT);
213 return NULL;
214 }
215 }
216 #endif /* HAVE_INET_NTOP */
217