[WINHTTP] Sync with Wine Staging 3.9. CORE-14656
[reactos.git] / dll / win32 / winhttp / inet_ntop.c
1 /* from NetBSD: inet_ntop.c,v 1.9 2000/01/22 22:19:16 mycroft Exp */
2
3 /* Copyright (c) 1996 by Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
10 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
11 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
12 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
13 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
14 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
15 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
16 * SOFTWARE.
17 */
18
19 #include <stdio.h>
20
21 #ifndef IN6ADDRSZ
22 #define IN6ADDRSZ 16
23 #endif
24
25 #ifndef INT16SZ
26 #define INT16SZ 2
27 #endif
28
29 #ifdef SPRINTF_CHAR
30 # define SPRINTF(x) strlen(sprintf/**/x)
31 #else
32 # define SPRINTF(x) ((size_t)sprintf x)
33 #endif
34
35 /*
36 * WARNING: Don't even consider trying to compile this on a system where
37 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
38 */
39
40 static const char *inet_ntop4(const u_char *src, char *dst, size_t size);
41
42 #ifdef INET6
43 static const char *inet_ntop6(const u_char *src, char *dst, size_t size);
44 #endif
45
46 /* char *
47 * inet_ntop(af, src, dst, size)
48 * convert a network format address to presentation format.
49 * return:
50 * pointer to presentation format address (`dst'), or NULL (see errno).
51 * author:
52 * Paul Vixie, 1996.
53 */
54
55 PCSTR
56 WSAAPI
57 inet_ntop(INT Family, PVOID pAddr, PSTR pStringBuf, size_t StringBufSize)
58 {
59
60 switch (Family) {
61 case AF_INET:
62 return (inet_ntop4(pAddr, pStringBuf, StringBufSize));
63 #ifdef INET6
64 case AF_INET6:
65 return (inet_ntop6(pAddr, pStringBuf, StringBufSize));
66 #endif
67 default:
68 WSASetLastError(WSAEAFNOSUPPORT);
69 return (NULL);
70 }
71 /* NOTREACHED */
72 }
73
74 /* const char *
75 * inet_ntop4(src, dst, size)
76 * format an IPv4 address, more or less like inet_ntoa()
77 * return:
78 * `dst' (as a const)
79 * notes:
80 * (1) uses no statics
81 * (2) takes a u_char* not an in_addr as input
82 * author:
83 * Paul Vixie, 1996.
84 */
85 static const char *
86 inet_ntop4(const u_char *src, char *dst, size_t size)
87 {
88 static const char fmt[] = "%u.%u.%u.%u";
89 char tmp[sizeof "255.255.255.255"];
90
91 if (SPRINTF((tmp, fmt, src[0], src[1], src[2], src[3])) > size) {
92 WSASetLastError(WSAEINVAL);
93 return (NULL);
94 }
95 strcpy(dst, tmp);
96 return (dst);
97 }
98
99 #ifdef INET6
100 /* const char *
101 * inet_ntop6(src, dst, size)
102 * convert IPv6 binary address into presentation (printable) format
103 * author:
104 * Paul Vixie, 1996.
105 */
106 static const char *
107 inet_ntop6(const u_char *src, char *dst, size_t size)
108 {
109 /*
110 * Note that int32_t and int16_t need only be "at least" large enough
111 * to contain a value of the specified size. On some systems, like
112 * Crays, there is no such thing as an integer variable with 16 bits.
113 * Keep this in mind if you think this function should have been coded
114 * to use pointer overlays. All the world's not a VAX.
115 */
116 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
117 struct { int base, len; } best, cur;
118 u_int words[IN6ADDRSZ / INT16SZ];
119 int i;
120
121 /*
122 * Preprocess:
123 * Copy the input (bytewise) array into a wordwise array.
124 * Find the longest run of 0x00's in src[] for :: shorthanding.
125 */
126 memset(words, '\0', sizeof words);
127 for (i = 0; i < IN6ADDRSZ; i++)
128 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
129 best.base = -1;
130 cur.base = -1;
131 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
132 if (words[i] == 0) {
133 if (cur.base == -1)
134 cur.base = i, cur.len = 1;
135 else
136 cur.len++;
137 } else {
138 if (cur.base != -1) {
139 if (best.base == -1 || cur.len > best.len)
140 best = cur;
141 cur.base = -1;
142 }
143 }
144 }
145 if (cur.base != -1) {
146 if (best.base == -1 || cur.len > best.len)
147 best = cur;
148 }
149 if (best.base != -1 && best.len < 2)
150 best.base = -1;
151
152 /*
153 * Format the result.
154 */
155 tp = tmp;
156 for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
157 /* Are we inside the best run of 0x00's? */
158 if (best.base != -1 && i >= best.base &&
159 i < (best.base + best.len)) {
160 if (i == best.base)
161 *tp++ = ':';
162 continue;
163 }
164 /* Are we following an initial run of 0x00s or any real hex? */
165 if (i != 0)
166 *tp++ = ':';
167 /* Is this address an encapsulated IPv4? */
168 if (i == 6 && best.base == 0 &&
169 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
170 if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
171 return (NULL);
172 tp += strlen(tp);
173 break;
174 }
175 tp += SPRINTF((tp, "%x", words[i]));
176 }
177 /* Was it a trailing run of 0x00's? */
178 if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
179 *tp++ = ':';
180 *tp++ = '\0';
181
182 /*
183 * Check for overflow, copy, and we're done.
184 */
185 if ((size_t)(tp - tmp) > size) {
186 WSASetLastError(WSAEINVAL);
187 return (NULL);
188 }
189 strcpy(dst, tmp);
190 return (dst);
191 }
192 #endif
193