Extract the CRC-32 code from the 802.11 dissector into a separate file,

and use it in the Ethernet dissector as well, to check the FCS in
Ethernet frames, if present.


git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@8265 f5534014-38df-0310-8fa8-9805f1628bb7

6 files changed, 158 insertions, 84 deletions

diff --git a/Makefile.am b/Makefile.am
index 7eb27b5a8a..156c9588a9 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,7 +1,7 @@
 # Makefile.am
 # Automake file for Ethereal
 #
-# $Id: Makefile.am,v 1.612 2003/08/23 07:23:12 guy Exp $
+# $Id: Makefile.am,v 1.613 2003/08/26 05:09:55 guy Exp $
 #
 # Ethereal - Network traffic analyzer
 # By Gerald Combs <gerald@ethereal.com>
@@ -710,6 +710,8 @@ ETHEREAL_COMMON_SRC = \
 	column.h       \
 	conditions.c   \
 	conditions.h   \
+	crc32.c        \
+	crc32.h        \
 	crypt-des.c    \
 	crypt-des.h    \
 	crypt-md4.c    \
diff --git a/Makefile.nmake b/Makefile.nmake
index 79b48a13a5..d5fa0dcd03 100644
--- a/Makefile.nmake
+++ b/Makefile.nmake
@@ -1,7 +1,7 @@
 ## Makefile for building ethereal.exe with Microsoft C and nmake
 ## Use: $(MAKE) /$(MAKEFLAGS) -f makefile.nmake
 #
-# $Id: Makefile.nmake,v 1.325 2003/08/23 04:18:17 sahlberg Exp $
+# $Id: Makefile.nmake,v 1.326 2003/08/26 05:09:55 guy Exp $
 
 include config.nmake
 include <win32.mak>
@@ -402,6 +402,7 @@ ETHEREAL_COMMON_OBJECTS = \
 	cfile.obj       \
 	column.obj       \
 	conditions.obj   \
+	crc32.obj        \
 	crypt-des.obj    \
 	crypt-md4.obj    \
 	crypt-md5.obj    \
diff --git a/crc32.c b/crc32.c
new file mode 100644
index 0000000000..89bee5ba4b
--- /dev/null
+++ b/crc32.c
@@ -0,0 +1,107 @@
+/* crc32.c
+ * CRC-32 routine
+ *
+ * $Id: crc32.c,v 1.1 2003/08/26 05:09:55 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * Copyright 1998 Gerald Combs
+ *
+ * Copied from README.developer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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.
+ *
+ * Credits:
+ *
+ * Table from Solomon Peachy
+ * Routine from Chris Waters
+ */
+
+#include <glib.h>
+#include "crc32.h"
+
+const guint32 crc32_table[256] = {
+        0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
+        0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
+        0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
+        0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
+        0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
+        0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
+        0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
+        0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
+        0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
+        0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
+        0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
+        0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
+        0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
+        0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
+        0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
+        0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
+        0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
+        0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
+        0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
+        0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
+        0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
+        0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
+        0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
+        0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
+        0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
+        0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
+        0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
+        0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
+        0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
+        0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
+        0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
+        0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
+        0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
+        0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
+        0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
+        0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
+        0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
+        0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
+        0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
+        0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
+        0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
+        0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
+        0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
+        0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
+        0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
+        0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
+        0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
+        0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
+        0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
+        0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
+        0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
+        0x2d02ef8dL
+};
+
+
+guint32
+crc32(const unsigned char* buf, unsigned int len)
+{
+  unsigned int i;
+  guint32 crc32 = 0xFFFFFFFF, c_crc;
+
+  for (i = 0; i < len; i++)
+    crc32 = crc32_table[(crc32 ^ buf[i]) & 0xff] ^ (crc32 >> 8);
+
+  /* Byte reverse. */
+  c_crc = ((unsigned char)(crc32>>0)<<24) |
+    ((unsigned char)(crc32>>8)<<16) |
+    ((unsigned char)(crc32>>16)<<8) |
+    ((unsigned char)(crc32>>24)<<0);
+
+  return ( ~c_crc );
+}
diff --git a/crc32.h b/crc32.h
new file mode 100644
index 0000000000..36d952bbd4
--- /dev/null
+++ b/crc32.h
@@ -0,0 +1,29 @@
+/* crc32.h
+ * Declaration of CRC-32 routine and table
+ *
+ * $Id: crc32.h,v 1.1 2003/08/26 05:09:55 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * Copyright 1998 Gerald Combs
+ *
+ * Copied from README.developer
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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.
+ */
+
+extern const guint32 crc32_table[256];
+
+extern guint32 crc32(const unsigned char* buf, unsigned int len);
diff --git a/packet-eth.c b/packet-eth.c
index 47aa625407..9bd39edb14 100644
--- a/packet-eth.c
+++ b/packet-eth.c
@@ -1,7 +1,7 @@
 /* packet-eth.c
  * Routines for ethernet packet disassembly
  *
- * $Id: packet-eth.c,v 1.83 2003/08/26 04:34:26 guy Exp $
+ * $Id: packet-eth.c,v 1.84 2003/08/26 05:09:55 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -36,6 +36,7 @@
 #include "packet-ipx.h"
 #include "packet-isl.h"
 #include "packet-llc.h"
+#include "crc32.h"
 #include "tap.h"
 
 /* Interpret capture file as FW1 monitor file */
@@ -340,9 +341,18 @@ add_ethernet_trailer(proto_tree *fh_tree, int trailer_id, tvbuff_t *tvb,
 			  trailer_length, FALSE);
     }
     if (has_fcs) {
-      proto_tree_add_text(fh_tree, trailer_tvb, trailer_length, 4,
-			  "FCS: 0x%08x",
-			  tvb_get_ntohl(trailer_tvb, trailer_length));
+      guint32 sent_fcs = tvb_get_ntohl(trailer_tvb, trailer_length);
+      guint32 fcs = crc32(tvb_get_ptr(tvb, 0, tvb_length(tvb) - 4),
+          tvb_length(tvb) - 4);
+      if (fcs == sent_fcs) {
+	proto_tree_add_text(fh_tree, trailer_tvb, trailer_length, 4,
+			    "Frane check sequence: 0x%08x (correct)",
+			    sent_fcs);
+      } else {
+	proto_tree_add_text(fh_tree, trailer_tvb, trailer_length, 4,
+			    "Frane check sequence: 0x%08x (incorrect, should be 0x%08x)",
+			    sent_fcs, fcs);
+      }
     }
   }
 }
diff --git a/packet-ieee80211.c b/packet-ieee80211.c
index 493fbd376e..dd7a5dc301 100644
--- a/packet-ieee80211.c
+++ b/packet-ieee80211.c
@@ -3,7 +3,7 @@
  * Copyright 2000, Axis Communications AB
  * Inquiries/bugreports should be sent to Johan.Jorgensen@axis.com
  *
- * $Id: packet-ieee80211.c,v 1.92 2003/06/24 06:23:05 guy Exp $
+ * $Id: packet-ieee80211.c,v 1.93 2003/08/26 05:09:56 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -57,6 +57,7 @@
 #include "packet-llc.h"
 #include "packet-ieee80211.h"
 #include "etypes.h"
+#include "crc32.h"
 
 /* Defragment fragmented 802.11 datagrams */
 static gboolean wlan_defragment = TRUE;
@@ -80,9 +81,6 @@ static int wep_decrypt(guint8 *buf, guint32 len, int key_override);
 static tvbuff_t *try_decrypt_wep(tvbuff_t *tvb, guint32 offset, guint32 len);
 #define SSWAP(a,b) {guint8 tmp = s[a]; s[a] = s[b]; s[b] = tmp;}
 
-/* FCS utility function. */
-static guint32 crc32(const unsigned char* buf, unsigned int len);
-
 /* #define USE_ENV */
 /* When this is set, an unlimited number of WEP keys can be set in the
    environment:
@@ -2588,61 +2586,6 @@ proto_reg_handoff_ieee80211(void)
 		ieee80211_radio_handle);
 }
 
-static const guint32 wep_crc32_table[256] = {
-        0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
-        0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
-        0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
-        0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
-        0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
-        0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
-        0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
-        0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
-        0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
-        0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
-        0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
-        0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
-        0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
-        0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
-        0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
-        0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
-        0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
-        0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
-        0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
-        0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
-        0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
-        0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
-        0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
-        0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
-        0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
-        0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
-        0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
-        0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
-        0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
-        0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
-        0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
-        0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
-        0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
-        0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
-        0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
-        0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
-        0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
-        0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
-        0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
-        0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
-        0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
-        0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
-        0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
-        0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
-        0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
-        0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
-        0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
-        0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
-        0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
-        0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
-        0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
-        0x2d02ef8dL
-};
-
 static tvbuff_t *try_decrypt_wep(tvbuff_t *tvb, guint32 offset, guint32 len) {
   guint8 *tmp = NULL;
   int i;
@@ -2746,7 +2689,7 @@ static int wep_decrypt(guint8 *buf, guint32 len, int key_override) {
 #if 0
     printf("%02x\n", *dpos);
 #endif
-    crc = wep_crc32_table[(crc ^ *dpos++) & 0xff] ^ (crc >> 8);
+    crc = crc32_table[(crc ^ *dpos++) & 0xff] ^ (crc >> 8);
   }
   crc = ~crc;
 
@@ -2845,21 +2788,3 @@ static void init_wepkeys(void) {
 
   return;
 }
-
-static guint32
-crc32(const unsigned char* buf, unsigned int len)
-{
-  unsigned int i;
-  guint32 crc32 = 0xFFFFFFFF, c_crc;
-
-  for (i = 0; i < len; i++)
-    crc32 = wep_crc32_table[(crc32 ^ buf[i]) & 0xff] ^ (crc32 >> 8);
-
-  /* Byte reverse. */
-  c_crc = ((unsigned char)(crc32>>0)<<24) |
-    ((unsigned char)(crc32>>8)<<16) |
-    ((unsigned char)(crc32>>16)<<8) |
-    ((unsigned char)(crc32>>24)<<0);
-
-  return ( ~c_crc );
-}