summaryrefslogtreecommitdiffstats
path: root/lib/isc/inet_pton.c
blob: bde88e3bec604379e91a6c4609fba4a880698e07 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#include <config.h>

#include <errno.h>
#include <string.h>

#include <isc/net.h>

/*% INT16 Size */
#define NS_INT16SZ	 2
/*% IPv4 Address Size */
#define NS_INADDRSZ	 4
/*% IPv6 Address Size */
#define NS_IN6ADDRSZ	16

/*
 * WARNING: Don't even consider trying to compile this on a system where
 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
 */

static int inet_pton4(const char *src, unsigned char *dst);
static int inet_pton6(const char *src, unsigned char *dst);

/*%
 *	convert from presentation format (which usually means ASCII printable)
 *	to network format (which is usually some kind of binary format).
 * \return
 *	1 if the address was valid for the specified address family
 *	0 if the address wasn't valid (`dst' is untouched in this case)
 *	-1 if some other error occurred (`dst' is untouched in this case, too)
 * \author
 *	Paul Vixie, 1996.
 */
int
isc_net_pton(int af, const char *src, void *dst) {
	switch (af) {
	case AF_INET:
		return (inet_pton4(src, dst));
	case AF_INET6:
		return (inet_pton6(src, dst));
	default:
		errno = EAFNOSUPPORT;
		return (-1);
	}
	/* NOTREACHED */
}

/*!\fn static int inet_pton4(const char *src, unsigned char *dst)
 * \brief
 *	like inet_aton() but without all the hexadecimal and shorthand.
 * \return
 *	1 if `src' is a valid dotted quad, else 0.
 * \note
 *	does not touch `dst' unless it's returning 1.
 * \author
 *	Paul Vixie, 1996.
 */
static int
inet_pton4(const char *src, unsigned char *dst) {
	static const char digits[] = "0123456789";
	int saw_digit, octets, ch;
	unsigned char tmp[NS_INADDRSZ], *tp;

	saw_digit = 0;
	octets = 0;
	*(tp = tmp) = 0;
	while ((ch = *src++) != '\0') {
		const char *pch;

		if ((pch = strchr(digits, ch)) != NULL) {
			unsigned int byte = *tp * 10;

			byte += (int)(pch - digits);
			if (saw_digit && *tp == 0)
				return (0);
			if (byte > 255)
				return (0);
			*tp = byte;
			if (!saw_digit) {
				if (++octets > 4)
					return (0);
				saw_digit = 1;
			}
		} else if (ch == '.' && saw_digit) {
			if (octets == 4)
				return (0);
			*++tp = 0;
			saw_digit = 0;
		} else
			return (0);
	}
	if (octets < 4)
		return (0);
	memmove(dst, tmp, NS_INADDRSZ);
	return (1);
}

/*%
 *	convert presentation level address to network order binary form.
 * \return
 *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
 * \note
 *	(1) does not touch `dst' unless it's returning 1.
 * \note
 *	(2) :: in a full address is silently ignored.
 * \author
 *	inspired by Mark Andrews.
 * \author
 *	Paul Vixie, 1996.
 */
static int
inet_pton6(const char *src, unsigned char *dst) {
	static const char xdigits_l[] = "0123456789abcdef",
			  xdigits_u[] = "0123456789ABCDEF";
	unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
	const char *xdigits, *curtok;
	int ch, seen_xdigits;
	unsigned int val;

	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
	endp = tp + NS_IN6ADDRSZ;
	colonp = NULL;
	/* Leading :: requires some special handling. */
	if (*src == ':')
		if (*++src != ':')
			return (0);
	curtok = src;
	seen_xdigits = 0;
	val = 0;
	while ((ch = *src++) != '\0') {
		const char *pch;

		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
			pch = strchr((xdigits = xdigits_u), ch);
		if (pch != NULL) {
			val <<= 4;
			val |= (pch - xdigits);
			if (++seen_xdigits > 4)
				return (0);
			continue;
		}
		if (ch == ':') {
			curtok = src;
			if (!seen_xdigits) {
				if (colonp)
					return (0);
				colonp = tp;
				continue;
			}
			if (tp + NS_INT16SZ > endp)
				return (0);
			*tp++ = (unsigned char) (val >> 8) & 0xff;
			*tp++ = (unsigned char) val & 0xff;
			seen_xdigits = 0;
			val = 0;
			continue;
		}
		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
		    inet_pton4(curtok, tp) > 0) {
			tp += NS_INADDRSZ;
			seen_xdigits = 0;
			break;	/* '\0' was seen by inet_pton4(). */
		}
		return (0);
	}
	if (seen_xdigits) {
		if (tp + NS_INT16SZ > endp)
			return (0);
		*tp++ = (unsigned char) (val >> 8) & 0xff;
		*tp++ = (unsigned char) val & 0xff;
	}
	if (colonp != NULL) {
		/*
		 * Since some memmove()'s erroneously fail to handle
		 * overlapping regions, we'll do the shift by hand.
		 */
		const int n = (int)(tp - colonp);
		int i;

		if (tp == endp)
			return (0);
		for (i = 1; i <= n; i++) {
			endp[- i] = colonp[n - i];
			colonp[n - i] = 0;
		}
		tp = endp;
	}
	if (tp != endp)
		return (0);
	memmove(dst, tmp, NS_IN6ADDRSZ);
	return (1);
}