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 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