ns-3-patch-csma-crc32.diff

--- ./src/csma/model/csma-net-device.cc	2013-05-12 18:50:15.000000000 +0200
+++ ./src/csma/model/csma-net-device.cc	2013-07-15 00:20:01.168749548 +0200
@@ -699,7 +699,6 @@ CsmaNetDevice::Receive (Ptr<Packet> pack
       trailer.EnableFcs (true);
     }
 
-  trailer.CheckFcs (packet);
   bool crcGood = trailer.CheckFcs (packet);
   if (!crcGood)
     {
--- ./src/network/utils/crc32.cc	1970-01-01 01:00:00.000000000 +0100
+++ ./src/network/utils/crc32.cc	2013-07-15 01:27:53.756850477 +0200
@@ -0,0 +1,72 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013 PIOTR JURKIEWICZ
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Piotr Jurkiewicz <piotr.jerzy.jurkiewicz@gmail.com>
+ */
+#include <stdint.h>
+
+namespace ns3 {
+
+static uint32_t crc32table[256] = {
+0x00000000,0x77073096,0xEE0E612C,0x990951BA,0x076DC419,0x706AF48F,0xE963A535,0x9E6495A3,
+0x0EDB8832,0x79DCB8A4,0xE0D5E91E,0x97D2D988,0x09B64C2B,0x7EB17CBD,0xE7B82D07,0x90BF1D91,
+0x1DB71064,0x6AB020F2,0xF3B97148,0x84BE41DE,0x1ADAD47D,0x6DDDE4EB,0xF4D4B551,0x83D385C7,
+0x136C9856,0x646BA8C0,0xFD62F97A,0x8A65C9EC,0x14015C4F,0x63066CD9,0xFA0F3D63,0x8D080DF5,
+0x3B6E20C8,0x4C69105E,0xD56041E4,0xA2677172,0x3C03E4D1,0x4B04D447,0xD20D85FD,0xA50AB56B,
+0x35B5A8FA,0x42B2986C,0xDBBBC9D6,0xACBCF940,0x32D86CE3,0x45DF5C75,0xDCD60DCF,0xABD13D59,
+0x26D930AC,0x51DE003A,0xC8D75180,0xBFD06116,0x21B4F4B5,0x56B3C423,0xCFBA9599,0xB8BDA50F,
+0x2802B89E,0x5F058808,0xC60CD9B2,0xB10BE924,0x2F6F7C87,0x58684C11,0xC1611DAB,0xB6662D3D,
+0x76DC4190,0x01DB7106,0x98D220BC,0xEFD5102A,0x71B18589,0x06B6B51F,0x9FBFE4A5,0xE8B8D433,
+0x7807C9A2,0x0F00F934,0x9609A88E,0xE10E9818,0x7F6A0DBB,0x086D3D2D,0x91646C97,0xE6635C01,
+0x6B6B51F4,0x1C6C6162,0x856530D8,0xF262004E,0x6C0695ED,0x1B01A57B,0x8208F4C1,0xF50FC457,
+0x65B0D9C6,0x12B7E950,0x8BBEB8EA,0xFCB9887C,0x62DD1DDF,0x15DA2D49,0x8CD37CF3,0xFBD44C65,
+0x4DB26158,0x3AB551CE,0xA3BC0074,0xD4BB30E2,0x4ADFA541,0x3DD895D7,0xA4D1C46D,0xD3D6F4FB,
+0x4369E96A,0x346ED9FC,0xAD678846,0xDA60B8D0,0x44042D73,0x33031DE5,0xAA0A4C5F,0xDD0D7CC9,
+0x5005713C,0x270241AA,0xBE0B1010,0xC90C2086,0x5768B525,0x206F85B3,0xB966D409,0xCE61E49F,
+0x5EDEF90E,0x29D9C998,0xB0D09822,0xC7D7A8B4,0x59B33D17,0x2EB40D81,0xB7BD5C3B,0xC0BA6CAD,
+0xEDB88320,0x9ABFB3B6,0x03B6E20C,0x74B1D29A,0xEAD54739,0x9DD277AF,0x04DB2615,0x73DC1683,
+0xE3630B12,0x94643B84,0x0D6D6A3E,0x7A6A5AA8,0xE40ECF0B,0x9309FF9D,0x0A00AE27,0x7D079EB1,
+0xF00F9344,0x8708A3D2,0x1E01F268,0x6906C2FE,0xF762575D,0x806567CB,0x196C3671,0x6E6B06E7,
+0xFED41B76,0x89D32BE0,0x10DA7A5A,0x67DD4ACC,0xF9B9DF6F,0x8EBEEFF9,0x17B7BE43,0x60B08ED5,
+0xD6D6A3E8,0xA1D1937E,0x38D8C2C4,0x4FDFF252,0xD1BB67F1,0xA6BC5767,0x3FB506DD,0x48B2364B,
+0xD80D2BDA,0xAF0A1B4C,0x36034AF6,0x41047A60,0xDF60EFC3,0xA867DF55,0x316E8EEF,0x4669BE79,
+0xCB61B38C,0xBC66831A,0x256FD2A0,0x5268E236,0xCC0C7795,0xBB0B4703,0x220216B9,0x5505262F,
+0xC5BA3BBE,0xB2BD0B28,0x2BB45A92,0x5CB36A04,0xC2D7FFA7,0xB5D0CF31,0x2CD99E8B,0x5BDEAE1D,
+0x9B64C2B0,0xEC63F226,0x756AA39C,0x026D930A,0x9C0906A9,0xEB0E363F,0x72076785,0x05005713,
+0x95BF4A82,0xE2B87A14,0x7BB12BAE,0x0CB61B38,0x92D28E9B,0xE5D5BE0D,0x7CDCEFB7,0x0BDBDF21,
+0x86D3D2D4,0xF1D4E242,0x68DDB3F8,0x1FDA836E,0x81BE16CD,0xF6B9265B,0x6FB077E1,0x18B74777,
+0x88085AE6,0xFF0F6A70,0x66063BCA,0x11010B5C,0x8F659EFF,0xF862AE69,0x616BFFD3,0x166CCF45,
+0xA00AE278,0xD70DD2EE,0x4E048354,0x3903B3C2,0xA7672661,0xD06016F7,0x4969474D,0x3E6E77DB,
+0xAED16A4A,0xD9D65ADC,0x40DF0B66,0x37D83BF0,0xA9BCAE53,0xDEBB9EC5,0x47B2CF7F,0x30B5FFE9,
+0xBDBDF21C,0xCABAC28A,0x53B39330,0x24B4A3A6,0xBAD03605,0xCDD70693,0x54DE5729,0x23D967BF,
+0xB3667A2E,0xC4614AB8,0x5D681B02,0x2A6F2B94,0xB40BBE37,0xC30C8EA1,0x5A05DF1B,0x2D02EF8D 
+};
+
+uint32_t
+CRC32Calculate (const uint8_t *data, int length)
+{
+  uint32_t crc = 0xffffffff;
+
+  while (length--)
+    {
+      crc = (crc >> 8) ^ crc32table[(crc & 0xFF) ^ *data++];
+    }
+  return ~crc;
+}
+
+} // namespace ns3
+
--- ./src/network/utils/crc32.h	1970-01-01 01:00:00.000000000 +0100
+++ ./src/network/utils/crc32.h	2013-07-15 01:32:05.228856709 +0200
@@ -0,0 +1,36 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013 PIOTR JURKIEWICZ
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Piotr Jurkiewicz <piotr.jerzy.jurkiewicz@gmail.com>
+ */
+#ifndef CRC32_H
+#define CRC32_H
+#include <stdint.h>
+
+namespace ns3 {
+
+/**
+ * \param data buffer to calculate the checksum for
+ * \param length the length of the buffer (bytes)
+ * \returns the computed crc.
+ *
+ */
+uint32_t CRC32Calculate (const uint8_t *data, int length);
+
+} // namespace ns3
+
+#endif
--- ./src/network/utils/ethernet-trailer.cc	2013-05-12 18:50:16.000000000 +0200
+++ ./src/network/utils/ethernet-trailer.cc	2013-07-15 01:37:55.400865387 +0200
@@ -22,6 +22,7 @@
 #include "ns3/log.h"
 #include "ns3/trailer.h"
 #include "ethernet-trailer.h"
+#include "crc32.h"
 
 NS_LOG_COMPONENT_DEFINE ("EthernetTrailer");
 
@@ -58,7 +59,7 @@ EthernetTrailer::CheckFcs (Ptr<const Pac
 
   buffer = new uint8_t[len];
   p->CopyData (buffer, len);
-  crc = DoCalcFcs (buffer, len);
+  crc = CRC32Calculate (buffer, len);
   delete[] buffer;
   return (m_fcs == crc);
 }
@@ -77,7 +78,7 @@ EthernetTrailer::CalcFcs (Ptr<const Pack
 
   buffer = new uint8_t[len];
   p->CopyData (buffer, len);
-  m_fcs = DoCalcFcs (buffer, len);
+  m_fcs = CRC32Calculate (buffer, len);
   delete[] buffer;
 }
 
@@ -151,24 +152,4 @@ EthernetTrailer::Deserialize (Buffer::It
   return size;
 }
 
-// This code is copied from /lib/crc32.c in the linux kernel.
-// It assumes little endian ordering.
-uint32_t
-EthernetTrailer::DoCalcFcs (uint8_t const *buffer, size_t len) const
-{
-  NS_LOG_FUNCTION (this << &buffer << len);
-  uint32_t crc = 0xffffffff;
-  int i;
-
-  while (len--)
-    {
-      crc ^= *buffer++;
-      for (i = 0; i < 8; i++)
-        {
-          crc = (crc >> 1) ^ ((crc & 1) ? 0xedb88320 : 0);
-        }
-    }
-  return ~crc;
-}
-
 } // namespace ns3
--- ./src/network/utils/ethernet-trailer.h	2013-05-12 18:50:16.000000000 +0200
+++ ./src/network/utils/ethernet-trailer.h	2013-07-15 01:37:38.732864974 +0200
@@ -104,8 +104,6 @@ private:
   bool m_calcFcs;
   uint32_t m_fcs; /// Value of the fcs contained in the trailer
 
-  uint32_t DoCalcFcs (uint8_t const *buffer, size_t len) const;
-
 };
 
 } // namespace ns3
--- ./src/network/wscript	2013-05-12 18:50:16.000000000 +0200
+++ ./src/network/wscript	2013-07-15 01:27:08.564849357 +0200
@@ -25,6 +25,7 @@ def build(bld):
         'model/trailer.cc',
         'utils/address-utils.cc',
         'utils/ascii-file.cc',
+        'utils/crc32.cc',
         'utils/data-rate.cc',
         'utils/drop-tail-queue.cc',
         'utils/error-model.cc',
@@ -98,6 +99,7 @@ def build(bld):
         'utils/address-utils.h',
         'utils/ascii-file.h',
         'utils/ascii-test.h',
+        'utils/crc32.h',
         'utils/data-rate.h',
         'utils/drop-tail-queue.h',
         'utils/error-model.h',