1 /* Copyright (c) 1996 by Internet Software Consortium.
2 *
3 * Permission to use, copy, modify, and distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
8 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
9 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
10 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
11 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
12 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
13 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
14 * SOFTWARE.
15 */
16
17 #include "config.h"
18
19 #include <ctype.h>
20 #include <errno.h>
21 #include <stdio.h>
22 #include <string.h>
23 #include <stdlib.h>
24
25 #include <sys/types.h>
26
27 #include "sofia-sip/su.h"
28
29 /*
30 * WARNING: Don't even consider trying to compile this on a system where
31 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
32 */
33
34 static const char *inet_ntop4(const unsigned char *src, char *dst, size_t size);
35 #if HAVE_SIN6
36 static const char *inet_ntop6(const unsigned char *src, char *dst, size_t size);
37 #endif
38
39 /* char *
40 * inet_ntop(af, src, dst, size)
41 * convert a network format address to presentation format.
42 * return:
43 * pointer to presentation format address (`dst'), or NULL (see errno).
44 * author:
45 * Paul Vixie, 1996.
46 */
47
48 /** inet_ntop() replacement.
49 *
50 * Convert a network format address to presentation format.
51 *
52 * @param af[in] address family
53 * @param src[in] network address to convert
54 * @param dst[out] return-value string
55 * @param size[in] maximum lenght of @a dst string
56 *
57 * @return Pointer to presentation format address (`dst'), or NULL (see errno).
58 *
59 * @author Paul Vixie, 1996.
60 *
61 * @NEW_1_12_9
62 */
63 const char *
su_inet_ntop(int af,void const * src,char * dst,size_t size)64 su_inet_ntop(int af, void const *src, char *dst, size_t size)
65 {
66
67 switch (af) {
68 case AF_INET:
69 return inet_ntop4(src, dst, size);
70 #if HAVE_SIN6
71 case AF_INET6:
72 return inet_ntop6(src, dst, size);
73 #endif
74 default:
75 su_seterrno(EAFNOSUPPORT);
76 return NULL;
77 }
78 /* NOTREACHED */
79 }
80
81 /* const char *
82 * inet_ntop4(src, dst, size)
83 * format an IPv4 address, more or less like inet_ntoa()
84 * return:
85 * `dst' (as a const)
86 * notes:
87 * (1) uses no statics
88 * (2) takes a unsigned char* not an in_addr as input
89 * author:
90 * Paul Vixie, 1996.
91 */
92 static const char *
inet_ntop4(const unsigned char * src,char * dst,size_t size)93 inet_ntop4(const unsigned char *src, char *dst, size_t size)
94 {
95 static const char fmt[] = "%u.%u.%u.%u";
96 char tmp[sizeof "255.255.255.255"];
97
98 if (snprintf(tmp, sizeof tmp, fmt,
99 src[0], src[1], src[2], src[3]) >= size) {
100 su_seterrno(ENOSPC);
101 return NULL;
102 }
103
104 return strcpy(dst, tmp);
105 }
106
107 #if HAVE_SIN6
108 /* const char *
109 * inet_ntop6(src, dst, size)
110 * convert IPv6 binary address into presentation (printable) format
111 * author:
112 * Paul Vixie, 1996.
113 */
114 static const char *
inet_ntop6(unsigned char const * src,char * dst,size_t size)115 inet_ntop6(unsigned char const *src, char *dst, size_t size)
116 {
117 /*
118 * Note that int32_t and int16_t need only be "at least" large enough
119 * to contain a value of the specified size. On some systems, like
120 * Crays, there is no such thing as an integer variable with 16 bits.
121 * Keep this in mind if you think this function should have been coded
122 * to use pointer overlays. All the world's not a VAX.
123 */
124 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
125 struct { int base, len; } best = { -1 , 0 }, cur = { -1, 0 };
126 unsigned int words[8];
127 int i;
128
129 /*
130 * Preprocess:
131 * Copy the input (bytewise) array into a wordwise array.
132 * Find the longest run of 0x00's in src[] for :: shorthanding.
133 */
134 for (i = 0; i < 16; i += 2)
135 words[i / 2] = (src[i] << 8) | (src[i + 1]);
136 best.base = -1;
137 cur.base = -1;
138 for (i = 0; i < 8; i++) {
139 if (words[i] == 0) {
140 if (cur.base == -1)
141 cur.base = i, cur.len = 1;
142 else
143 cur.len++;
144 } else {
145 if (cur.base != -1) {
146 if (best.base == -1 || cur.len > best.len)
147 best = cur;
148 cur.base = -1;
149 }
150 }
151 }
152 if (cur.base != -1) {
153 if (best.base == -1 || cur.len > best.len)
154 best = cur;
155 }
156 if (best.base != -1 && best.len < 2)
157 best.base = -1;
158
159 /*
160 * Format the result.
161 */
162 tp = tmp;
163 for (i = 0; i < 8; i++) {
164 /* Are we inside the best run of 0x00's? */
165 if (best.base != -1 && i >= best.base &&
166 i < (best.base + best.len)) {
167 if (i == best.base)
168 *tp++ = ':';
169 continue;
170 }
171 /* Are we following an initial run of 0x00s or any real hex? */
172 if (i != 0)
173 *tp++ = ':';
174 /* Is this address an encapsulated IPv4? */
175 if (i == 6 && best.base == 0 &&
176 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
177 if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
178 return (NULL);
179 tp += strlen(tp);
180 break;
181 }
182 tp += sprintf(tp, "%x", words[i]);
183 }
184 /* Was it a trailing run of 0x00's? */
185 if (best.base != -1 && (best.base + best.len) == 8)
186 *tp++ = ':';
187 *tp++ = '\0';
188
189 /*
190 * Check for overflow, copy, and we're done.
191 */
192 if ((size_t)(tp - tmp) >= size) {
193 su_seterrno(ENOSPC);
194 return NULL;
195 }
196
197 return strcpy(dst, tmp);
198 }
199 #endif
200