1 /*
2 * edns-subnet/edns-subnet.c - Subnet option related constants
3 *
4 * Copyright (c) 2013, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35 /**
36 * \file
37 * Subnet option related constants.
38 */
39
40 #include "config.h"
41
42 #ifdef CLIENT_SUBNET /* keeps splint happy */
43 #include "edns-subnet/edns-subnet.h"
44 #include <string.h>
45
46 int
copy_clear(uint8_t * dst,size_t dstlen,uint8_t * src,size_t srclen,size_t n)47 copy_clear(uint8_t* dst, size_t dstlen, uint8_t* src, size_t srclen, size_t n)
48 {
49 size_t intpart = n / 8; /* bytes */
50 size_t fracpart = n % 8; /* bits */
51 size_t written = intpart;
52 if (intpart > dstlen || intpart > srclen)
53 return 1;
54 if (fracpart && (intpart+1 > dstlen || intpart+1 > srclen))
55 return 1;
56 memcpy(dst, src, intpart);
57 if (fracpart) {
58 dst[intpart] = src[intpart] & ~(0xFF >> fracpart);
59 written++;
60 }
61 memset(dst + written, 0, dstlen - written);
62 return 0;
63 }
64
65 #endif /* CLIENT_SUBNET */
66