TCPIPchecksum.h

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00001 //
00002 // Copyright (C) 2005 Christian Dankbar, Irene Ruengeler, Michael Tuexen
00003 //               2009 Zoltan Bojthe
00004 //
00005 // This program is free software; you can redistribute it and/or
00006 // modify it under the terms of the GNU General Public License
00007 // as published by the Free Software Foundation; either version 2
00008 // of the License, or (at your option) any later version.
00009 //
00010 // This program is distributed in the hope that it will be useful,
00011 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00012 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013 // GNU General Public License for more details.
00014 //
00015 // You should have received a copy of the GNU General Public License
00016 // along with this program; if not, see <http://www.gnu.org/licenses/>.
00017 //
00018 
00019 #ifndef __TCPIPCHECKSUM_H
00020 #define __TCPIPCHECKSUM_H
00021 
00022 
00023 #include "TCPSegment.h"
00024 #include "TCPSegment_m.h"
00025 #include "IPvXAddress.h"
00026 
00027 #include "headers/defs.h"
00028 
00029 #include "headers/tcp.h"
00030 
00034 class TCPIPchecksum
00035 {
00036     public:
00037         TCPIPchecksum() {}
00038 
00039         /*
00040          * calculate the 16 bit one's complement of the one's
00041          * complement sum of all 16 bit words in the header and text.  If a
00042          * segment contains an odd number of header and text octets to be
00043          * checksummed, the last octet is padded on the right with zeros to
00044          * form a 16 bit word for checksum purposes
00045         */
00046         static uint16_t checksum(const void *addr, unsigned int count)
00047         {
00048             return ~ _checksum(addr, count);
00049         }
00050 
00051         static uint16_t _checksum(const void *addr, unsigned int count);
00052 };
00053 
00054 #endif