From Francesco Fondelli:

You find attached a patch file (against svn 19058) to dissect packets
produced by the Linux kernel packet generator.

svn path=/trunk/; revision=19251

1 files changed, 209 insertions, 0 deletions

diff --git a/epan/dissectors/packet-pktgen.c b/epan/dissectors/packet-pktgen.c
new file mode 100644
index 0000000000..1b67ead2db
--- /dev/null
+++ b/epan/dissectors/packet-pktgen.c
@@ -0,0 +1,209 @@
+/* packet-pktgen.c
+ * Routines for "Linux pktgen" dissection
+ * Copyright 2006 _FF_ 
+ * Francesco Fondelli <francesco dot fondelli, gmail dot com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * 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.
+ */
+
+/* FF:
+ * The linux packet generator is a tool to generate packets at very high speed in the kernel.
+ * See linux/net/core/pktgen.c and linux/Documentation/networking/pktgen.txt 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 pktgen_magic[] = { 0xbe, 0x9b, 0xe9, 0x55 };
+
+/* Initialize the protocol and registered fields */
+static int proto_pktgen = -1;
+
+/* pktgen header */
+static int hf_pktgen_magic = -1;
+static int hf_pktgen_seqnum = -1;
+static int hf_pktgen_tvsec = -1;
+static int hf_pktgen_tvusec = -1;
+static int hf_pktgen_timestamp = -1;
+
+/* Initialize the subtree pointer */
+static gint ett_pktgen = -1;
+
+/* data dissector handle */
+static dissector_handle_t data_handle = NULL;
+
+/* entry point */
+static gboolean dissect_pktgen(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+    proto_item *ti = NULL;
+    proto_item *tmp = NULL;
+    proto_tree *pktgen_tree = NULL;
+    guint32 offset = 0;
+    nstime_t tstamp;
+
+    /* check for min size */
+    if(!tvb_bytes_exist(tvb, 0, 16)) { 	/* Not a PKTGEN packet. */
+	return FALSE;
+    }
+    
+    /* check for magic number */
+    if(tvb_memeql(tvb, 0, pktgen_magic, 4) == -1) { /* Not a PKTGEN 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, "PKTGEN");
+    
+    if(check_col(pinfo->cinfo, COL_INFO)) {
+	col_add_fstr(pinfo->cinfo, COL_INFO, "Seq: %u", tvb_get_ntohl(tvb, 4));
+    }
+    
+    if(tree) {
+	
+	/* create display subtree for the protocol */
+	
+	ti = proto_tree_add_item(tree, proto_pktgen, tvb, 0, -1, FALSE);
+	
+	pktgen_tree = proto_item_add_subtree(ti, ett_pktgen);
+	
+	/* add items to the subtree */
+	
+	proto_tree_add_item(pktgen_tree, hf_pktgen_magic, tvb, offset, 4, FALSE);
+	offset+=4;
+
+	proto_tree_add_item(pktgen_tree, hf_pktgen_seqnum, tvb, offset, 4, FALSE);
+	offset+=4;
+
+	tstamp.secs = tvb_get_ntohl(tvb, offset);
+	tmp = proto_tree_add_item(pktgen_tree, hf_pktgen_tvsec, tvb, offset, 4, FALSE);
+	PROTO_ITEM_SET_GENERATED(tmp);
+	offset+=4;
+
+	tstamp.nsecs = tvb_get_ntohl(tvb, offset) /* microsecond on the wire so... */ * 1000;
+	tmp = proto_tree_add_item(pktgen_tree, hf_pktgen_tvusec, tvb, offset, 4, FALSE);
+	PROTO_ITEM_SET_GENERATED(tmp);
+	offset+=4;
+	
+	proto_tree_add_time(pktgen_tree, hf_pktgen_timestamp, tvb, offset - 8, 8, &tstamp);
+	
+#if 0
+	if(tvb_length_remaining(tvb, offset)) /* random data */
+	    proto_tree_add_text(pktgen_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,
+		pktgen_tree);
+#endif
+    }
+
+    return TRUE;
+}
+
+
+/* Register the protocol with Wireshark */
+void proto_register_pktgen(void)
+{                 
+    /* Setup list of header fields */
+    
+    static hf_register_info hf[] = {
+	
+	{ &hf_pktgen_magic,
+	  { 
+	      "Magic number", "pktgen.magic", 
+	      FT_UINT32, BASE_HEX, NULL, 0x0, 
+	      "The pktgen magic number", HFILL
+	  }
+	},
+	
+	{ &hf_pktgen_seqnum,
+	  { 
+	      "Sequence number", "pktgen.seqnum", 
+	      FT_UINT32, BASE_DEC, NULL, 0x0, 
+	      "Sequence number", HFILL
+	  }
+	},
+
+	{ &hf_pktgen_tvsec,
+	  { 
+	      "Timestamp tvsec", "pktgen.tvsec", 
+	      FT_UINT32, BASE_DEC, NULL, 0x0, 
+	      "Timestamp tvsec part", HFILL
+	  }
+	},
+
+	{ &hf_pktgen_tvusec,
+	  { 
+	      "Timestamp tvusec", "pktgen.tvusec", 
+	      FT_UINT32, BASE_DEC, NULL, 0x0, 
+	      "Timestamp tvusec part", HFILL
+	  }
+	},
+
+	{ &hf_pktgen_timestamp,
+	  { 
+	      "Timestamp", "pktgen.timestamp", 
+	      FT_ABSOLUTE_TIME, BASE_HEX, NULL, 0x0,
+	      "Timestamp", HFILL
+	  }
+	}		
+    };
+	
+    /* Setup protocol subtree array */
+	
+    static gint *ett[] = {
+	&ett_pktgen
+    };
+	
+    /* Register the protocol name and description */
+	
+    proto_pktgen = proto_register_protocol("Linux Kernel Packet Generator", "PKTGEN", "pktgen");
+	
+    /* Required function calls to register the header fields and subtrees used */
+	
+    proto_register_field_array(proto_pktgen, hf, array_length(hf));
+    proto_register_subtree_array(ett, array_length(ett));
+}
+
+
+void proto_reg_handoff_pktgen(void)
+{
+    /* Register as a heuristic UDP dissector */
+    heur_dissector_add("udp", dissect_pktgen, proto_pktgen);
+
+    /* Find data dissector handle */
+    data_handle = find_dissector("data");
+}