Wireshark · Wireshark-dev: [Wireshark-dev] Patch to support decoding LANforge packets.

[Ben Greear <greearb@xxxxxxxxxxxxxxx>]

LANforge is a network traffic generator that my company sells.  Part of 
our feature set
is UDP and TCP traffic generation.  We have a small header followed by a 
payload.  The
payload is normally just filler and of no special interest to users.

Attached is a patch to decode the LANforge header.  Please consider
adding this to Wireshark, and let me know if there are any suggestions
for improvement.

Thanks,
Ben

--
Ben Greear <greearb@xxxxxxxxxxxxxxx> 
Candela Technologies Inc  http://www.candelatech.com


Index: epan/dissectors/Makefile.common
===================================================================
--- epan/dissectors/Makefile.common	(revision 25831)
+++ epan/dissectors/Makefile.common	(working copy)
@@ -518,6 +518,7 @@
 	packet-kismet.c		\
 	packet-kpasswd.c	\
 	packet-l2tp.c		\
+	packet-lanforge.c	\
 	packet-lapb.c		\
 	packet-lapbether.c	\
 	packet-lapd.c		\
Index: epan/dissectors/packet-lanforge.c
===================================================================
--- epan/dissectors/packet-lanforge.c	(revision 0)
+++ epan/dissectors/packet-lanforge.c	(revision 0)
@@ -0,0 +1,275 @@
+/* packet-lanforge.c
+ * Routines for "LANforge traffic generator IP protocol" dissection
+ * Copyright 2008
+ * Ben Greear <greearb@xxxxxxxxxxxxxxx>
+ *
+ * Based on pktgen dissectory by:
+ * Francesco Fondelli <francesco dot fondelli, gmail dot com>
+ *
+ * $Id: packet-lanforge.c 23412 2007-11-09 06:01:18Z etxrab $
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@xxxxxxxxxxxxx>
+ * Copyright 1998 Gerald Combs
+ * 
+ * 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.
+ */
+
+/* LANforge generates network traffic for load & performance testing.
+ * See http://www.candelatech.com for more info.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#if 0
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#endif
+
+#include <glib.h>
+
+#include <epan/packet.h>
+#include <epan/emem.h>
+
+/* magic num used for heuristic */
+static const guint8 lanforge_magic[] = { 0x1a, 0x2b, 0x3c, 0x4d };
+
+/* Initialize the protocol and registered fields */
+static int proto_lanforge = -1;
+
+/* lanforge header */
+static int hf_lanforge_crc = -1;
+static int hf_lanforge_magic = -1;
+static int hf_lanforge_src_session = -1;
+static int hf_lanforge_dst_session = -1;
+static int hf_lanforge_pld_len = -1;
+static int hf_lanforge_pld_pattern = -1;
+static int hf_lanforge_seq = -1;
+static int hf_lanforge_tx_time_s = -1;
+static int hf_lanforge_tx_time_ns = -1;
+static int hf_lanforge_timestamp = -1;
+
+/* Initialize the subtree pointer */
+static gint ett_lanforge = -1;
+
+/* data dissector handle */
+static dissector_handle_t data_handle = NULL;
+
+/* entry point */
+static gboolean dissect_lanforge(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+    proto_item *ti = NULL;
+    proto_item *tmp = NULL;
+    proto_tree *lanforge_tree = NULL;
+    guint32 offset = 0;
+    nstime_t tstamp;
+    guint32 tss;
+
+    /* check for min size */
+    if(tvb_length(tvb) < 28) { 	/* Not a LANforge packet. */
+	return FALSE;
+    }
+    
+    /* check for magic number */
+    if(tvb_memeql(tvb, 4, lanforge_magic, 4) == -1) { /* Not a LANforge packet. */
+       return FALSE;
+    }
+        
+    /* Make entries in Protocol column and Info column on summary display */
+    
+    if(check_col(pinfo->cinfo, COL_PROTOCOL)) 
+	col_set_str(pinfo->cinfo, COL_PROTOCOL, "LANforge");
+    
+    if(check_col(pinfo->cinfo, COL_INFO)) {
+	col_add_fstr(pinfo->cinfo, COL_INFO, "Seq: %u", tvb_get_ntohl(tvb, 16));
+    }
+    
+    if(tree) {
+	
+	/* create display subtree for the protocol */
+	
+	ti = proto_tree_add_item(tree, proto_lanforge, tvb, 0, -1, FALSE);
+	
+	lanforge_tree = proto_item_add_subtree(ti, ett_lanforge);
+	
+	/* add items to the subtree */
+	
+	proto_tree_add_item(lanforge_tree, hf_lanforge_crc, tvb, offset, 4, FALSE);
+	offset+=4;
+
+        proto_tree_add_item(lanforge_tree, hf_lanforge_magic, tvb, offset, 4, FALSE);
+	offset+=4;
+
+	proto_tree_add_item(lanforge_tree, hf_lanforge_src_session, tvb, offset, 2, FALSE);
+	offset+=2;
+        
+	proto_tree_add_item(lanforge_tree, hf_lanforge_dst_session, tvb, offset, 2, FALSE);
+	offset+=2;
+
+        proto_tree_add_item(lanforge_tree, hf_lanforge_pld_len, tvb, offset, 2, FALSE);
+        offset+=2;
+
+        proto_tree_add_item(lanforge_tree, hf_lanforge_pld_pattern, tvb, offset, 2, FALSE);
+        offset+=2;
+
+        proto_tree_add_item(lanforge_tree, hf_lanforge_seq, tvb, offset, 4, FALSE);
+	offset+=4;
+
+        tss = tvb_get_ntohl(tvb, offset);
+	tstamp.secs = tss;
+	tmp = proto_tree_add_item(lanforge_tree, hf_lanforge_tx_time_s, tvb, offset, 4, FALSE);
+	PROTO_ITEM_SET_GENERATED(tmp);
+	offset+=4;
+
+        tss = tvb_get_ntohl(tvb, offset);
+	tstamp.nsecs = tss;
+	tmp = proto_tree_add_item(lanforge_tree, hf_lanforge_tx_time_ns, tvb, offset, 4, FALSE);
+	PROTO_ITEM_SET_GENERATED(tmp);
+	offset+=4;
+
+	proto_tree_add_time(lanforge_tree, hf_lanforge_timestamp, tvb, offset - 8, 8, &tstamp);
+	
+#if 0
+	if(tvb_length_remaining(tvb, offset)) /* random data */
+	    proto_tree_add_text(lanforge_tree, tvb, offset, -1, "Data (%u bytes)",
+				tvb_length_remaining(tvb, offset));
+#else
+	if(tvb_length_remaining(tvb, offset)) /* random data */
+	    call_dissector(data_handle, tvb_new_subset(tvb, offset, -1, -1), pinfo,
+		lanforge_tree);
+#endif
+    }
+
+    return TRUE;
+}
+
+
+/* Register the protocol with Wireshark */
+void proto_register_lanforge(void)
+{                 
+    /* Setup list of header fields */
+    
+    static hf_register_info hf[] = {
+	
+	{ &hf_lanforge_crc,
+	  { 
+	      "CRC", "LANforge.CRC", 
+	      FT_UINT32, BASE_HEX, NULL, 0x0, 
+	      "The LANforge CRC number", HFILL
+	  }
+	},
+
+        { &hf_lanforge_magic,
+	  { 
+	      "Magic number", "LANforge.magic", 
+	      FT_UINT32, BASE_HEX, NULL, 0x0, 
+	      "The LANforge magic number", HFILL
+	  }
+	},
+
+	{ &hf_lanforge_src_session,
+	  { 
+	      "Source session ID", "LANforge.source-session-id", 
+	      FT_UINT16, BASE_DEC, NULL, 0x0, 
+	      "The LANforge source session ID", HFILL
+	  }
+	},
+        
+	{ &hf_lanforge_dst_session,
+	  { 
+	      "Dest session ID", "LANforge.dest-session-id", 
+	      FT_UINT16, BASE_DEC, NULL, 0x0, 
+	      "The LANforge dest session ID", HFILL
+	  }
+	},
+        
+	{ &hf_lanforge_pld_len,
+	  { 
+	      "Payload Length", "LANforge.pld-length", 
+	      FT_UINT16, BASE_DEC, NULL, 0x0, 
+	      "The LANforge payload length", HFILL
+	  }
+	},
+
+        { &hf_lanforge_pld_pattern,
+	  { 
+	      "Payload Pattern", "LANforge.pld-pattern", 
+	      FT_UINT16, BASE_DEC, NULL, 0x0, 
+	      "The LANforge payload pattern", HFILL
+	  }
+	},
+
+	{ &hf_lanforge_seq,
+	  { 
+	      "Sequence Number", "LANforge.seqno", 
+	      FT_UINT32, BASE_DEC, NULL, 0x0, 
+	      "The LANforge Sequence Number", HFILL
+	  }
+	},
+
+	{ &hf_lanforge_tx_time_s,
+	  { 
+	      "Timestamp Secs", "LANforge.ts-secs", 
+	      FT_UINT32, BASE_DEC, NULL, 0x0, 
+	      "Timestamp secs", HFILL
+	  }
+	},
+        
+	{ &hf_lanforge_tx_time_ns,
+	  { 
+	      "Timestamp nsecs", "LANforge.ts-nsecs", 
+	      FT_UINT32, BASE_DEC, NULL, 0x0, 
+	      "Timestamp nsecs", HFILL
+	  }
+	},
+
+	{ &hf_lanforge_timestamp,
+	  { 
+	      "Timestamp", "LANforge.timestamp", 
+	      FT_ABSOLUTE_TIME, BASE_HEX, NULL, 0x0,
+	      "Timestamp", HFILL
+	  }
+	}
+    };
+	
+    /* Setup protocol subtree array */
+	
+    static gint *ett[] = {
+	&ett_lanforge
+    };
+	
+    /* Register the protocol name and description */
+	
+    proto_lanforge = proto_register_protocol("LANforge Traffic Generator", "LANforge", "lanforge");
+	
+    /* Required function calls to register the header fields and subtrees used */
+	
+    proto_register_field_array(proto_lanforge, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
+}
+
+
+void proto_reg_handoff_lanforge(void)
+{
+    /* Register as a heuristic UDP dissector */
+    heur_dissector_add("udp", dissect_lanforge, proto_lanforge);
+    heur_dissector_add("tcp", dissect_lanforge, proto_lanforge); 
+
+    /* Find data dissector handle */
+    data_handle = find_dissector("data");
+}