00001 // $Id: IpChecksum.cci 1742 2010-11-04 14:51:56Z g0dil $ 00002 // 00003 // Copyright (C) 2007 00004 // Fraunhofer (FOKUS) 00005 // Competence Center NETwork research (NET), St. Augustin, GERMANY 00006 // Stefan Bund <g0dil@berlios.de> 00007 // 00008 // This program is free software; you can redistribute it and/or modify 00009 // it under the terms of the GNU General Public License as published by 00010 // the Free Software Foundation; either version 2 of the License, or 00011 // (at your option) any later version. 00012 // 00013 // This program is distributed in the hope that it will be useful, 00014 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00016 // GNU General Public License for more details. 00017 // 00018 // You should have received a copy of the GNU General Public License 00019 // along with this program; if not, write to the 00020 // Free Software Foundation, Inc., 00021 // 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 00022 00026 // Custom includes 00027 00028 #define prefix_ inline 00029 //-///////////////////////////////////////////////////////////////////////////////////////////////// 00030 00031 prefix_ senf::IpChecksum::IpChecksum() 00032 : sum_(0), odd_(false) 00033 {} 00034 00035 prefix_ void senf::IpChecksum::feed(boost::uint8_t byte) 00036 { 00037 sum_ += odd_ ? byte : (byte<<8); 00038 odd_ = ! odd_; 00039 } 00040 00041 prefix_ boost::uint16_t senf::IpChecksum::sum() 00042 const 00043 { 00044 boost::uint32_t v (sum_); 00045 while (v >> 16) 00046 v = (v & 0xffff) + (v >> 16); 00047 return ~ v; 00048 } 00049 00050 //-///////////////////////////////////////////////////////////////////////////////////////////////// 00051 #undef prefix_ 00052 00053 00054 // Local Variables: 00055 // mode: c++ 00056 // fill-column: 100 00057 // comment-column: 40 00058 // c-file-style: "senf" 00059 // indent-tabs-mode: nil 00060 // ispell-local-dictionary: "american" 00061 // compile-command: "scons -u test" 00062 // End: