Annotation of embedaddon/curl/lib/inet_ntop.c, revision 1.1.1.1
1.1 misho 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 */
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