aboutsummaryrefslogtreecommitdiff
path: root/contrib/isc-dhcp/common/inet.c
blob: f4468673c5c54488b803facca36a126caed94e4c (plain) (blame)
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
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
/* inet.c

   Subroutines to manipulate internet addresses in a safely portable
   way... */

/*
 * Copyright (c) 1995-2002 Internet Software Consortium.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of The Internet Software Consortium nor the names
 *    of its contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * This software has been written for the Internet Software Consortium
 * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
 * To learn more about the Internet Software Consortium, see
 * ``http://www.isc.org/''.  To learn more about Vixie Enterprises,
 * see ``http://www.vix.com''.   To learn more about Nominum, Inc., see
 * ``http://www.nominum.com''.
 */

#ifndef lint
static char copyright[] =
"$Id: inet.c,v 1.8.2.4 2002/11/17 02:26:58 dhankins Exp $ Copyright (c) 1995-2002 The Internet Software Consortium.  All rights reserved.\n";
#endif /* not lint */

#include "dhcpd.h"

/* Return just the network number of an internet address... */

struct iaddr subnet_number (addr, mask)
	struct iaddr addr;
	struct iaddr mask;
{
	int i;
	struct iaddr rv;

	rv.len = 0;

	/* Both addresses must have the same length... */
	if (addr.len != mask.len)
		return rv;

	rv.len = addr.len;
	for (i = 0; i < rv.len; i++)
		rv.iabuf [i] = addr.iabuf [i] & mask.iabuf [i];
	return rv;
}

/* Combine a network number and a integer to produce an internet address.
   This won't work for subnets with more than 32 bits of host address, but
   maybe this isn't a problem. */

struct iaddr ip_addr (subnet, mask, host_address)
	struct iaddr subnet;
	struct iaddr mask;
	u_int32_t host_address;
{
	int i, j, k;
	u_int32_t swaddr;
	struct iaddr rv;
	unsigned char habuf [sizeof swaddr];

	swaddr = htonl (host_address);
	memcpy (habuf, &swaddr, sizeof swaddr);

	/* Combine the subnet address and the host address.   If
	   the host address is bigger than can fit in the subnet,
	   return a zero-length iaddr structure. */
	rv = subnet;
	j = rv.len - sizeof habuf;
	for (i = sizeof habuf - 1; i >= 0; i--) {
		if (mask.iabuf [i + j]) {
			if (habuf [i] > (mask.iabuf [i + j] ^ 0xFF)) {
				rv.len = 0;
				return rv;
			}
			for (k = i - 1; k >= 0; k--) {
				if (habuf [k]) {
					rv.len = 0;
					return rv;
				}
			}
			rv.iabuf [i + j] |= habuf [i];
			break;
		} else
			rv.iabuf [i + j] = habuf [i];
	}
		
	return rv;
}

/* Given a subnet number and netmask, return the address on that subnet
   for which the host portion of the address is all ones (the standard
   broadcast address). */

struct iaddr broadcast_addr (subnet, mask)
	struct iaddr subnet;
	struct iaddr mask;
{
	int i, j, k;
	struct iaddr rv;

	if (subnet.len != mask.len) {
		rv.len = 0;
		return rv;
	}

	for (i = 0; i < subnet.len; i++) {
		rv.iabuf [i] = subnet.iabuf [i] | (~mask.iabuf [i] & 255);
	}
	rv.len = subnet.len;

	return rv;
}

u_int32_t host_addr (addr, mask)
	struct iaddr addr;
	struct iaddr mask;
{
	int i;
	u_int32_t swaddr;
	struct iaddr rv;

	rv.len = 0;

	/* Mask out the network bits... */
	rv.len = addr.len;
	for (i = 0; i < rv.len; i++)
		rv.iabuf [i] = addr.iabuf [i] & ~mask.iabuf [i];

	/* Copy out up to 32 bits... */
	memcpy (&swaddr, &rv.iabuf [rv.len - sizeof swaddr], sizeof swaddr);

	/* Swap it and return it. */
	return ntohl (swaddr);
}

int addr_eq (addr1, addr2)
	struct iaddr addr1, addr2;
{
	if (addr1.len != addr2.len)
		return 0;
	return memcmp (addr1.iabuf, addr2.iabuf, addr1.len) == 0;
}

char *piaddr (addr)
	struct iaddr addr;
{
	static char pbuf [4 * 16];
	char *s = pbuf;
	int i;

	if (addr.len == 0) {
		strcpy (s, "<null address>");
	}
	for (i = 0; i < addr.len; i++) {
		sprintf (s, "%s%d", i ? "." : "", addr.iabuf [i]);
		s += strlen (s);
	}
	return pbuf;
}

char *piaddr1 (addr)
	struct iaddr addr;
{
	static char pbuf [4 * 16];
	char *s = pbuf;
	int i;

	if (addr.len == 0) {
		strcpy (s, "<null address>");
	}
	for (i = 0; i < addr.len; i++) {
		sprintf (s, "%s%d", i ? "." : "", addr.iabuf [i]);
		s += strlen (s);
	}
	return pbuf;
}

char *piaddrmask (struct iaddr addr, struct iaddr mask,
		  const char *file, int line)
{
	char *s, *t;
	int i, mw;
	unsigned len;

	for (i = 0; i < 32; i++) {
		if (!mask.iabuf [3 - i / 8])
			i += 7;
		else if (mask.iabuf [3 - i / 8] & (1 << (i % 8)))
			break;
	}
	mw = 32 - i;
	len = mw > 9 ? 2 : 1;
	len += 4;	/* three dots and a slash. */
	for (i = 0; i < (mw / 8) + 1; i++) {
		if (addr.iabuf [i] > 99)
			len += 3;
		else if (addr.iabuf [i] > 9)
			len += 2;
		else
			len++;
	}
	s = dmalloc (len + 1, file, line);
	if (!s)
		return s;
	t = s;
	sprintf (t, "%d", addr.iabuf [0]);
	t += strlen (t);
	for (i = 1; i < (mw / 8) + 1; i++) {
		sprintf (t, ".%d", addr.iabuf [i]);
		t += strlen (t);
	}
	*t++ = '/';
	sprintf (t, "%d", mw);
	return s;
}