From Xiao Xiangquan via https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=5846

A new dissector for uTorrent Transport Protocol

From me :
* Add link to spec BEP-0029
* Add note about type/version 
* Rework extensions loop
* Use 2-space indenting


svn path=/trunk/; revision=36716

1 files changed, 710 insertions, 0 deletions

diff --git a/epan/dissectors/packet-bt-utp.c b/epan/dissectors/packet-bt-utp.c
new file mode 100644
index 0000000000..4b6d839d9a
--- /dev/null
+++ b/epan/dissectors/packet-bt-utp.c
@@ -0,0 +1,710 @@
+/* packet-bt-utp.c
+ * Routines for BT-UTP dissection
+ * Copyright 2011, Xiao Xiangquan <xiaoxiangquan@gmail.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1999 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <epan/packet.h>
+#include <epan/prefs.h>
+
+#define DEFAULT_UDP_PORT 55627
+
+static const value_string bt_utp_type_vals[] = {
+  { 0, "Data" },
+  { 1, "Fin" },
+  { 2, "State" },
+  { 3, "Reset" },
+  { 4, "Syn" },
+  { 0, NULL }
+};
+
+#define EXT_NO_EXTENSION    0
+#define EXT_SELECTION_ACKS  1
+#define EXT_EXTENSION_BITS  2
+
+static const value_string bt_utp_extension_type_vals[] = {
+  { EXT_NO_EXTENSION, "No Extension" },
+  { EXT_SELECTION_ACKS, "Selective acks" },
+  { EXT_EXTENSION_BITS, "Extension bits" },
+  { 0, NULL }
+};
+
+static int proto_bt_utp = -1;
+
+/* Specifications: BEP-0029
+http://www.bittorrent.org/beps/bep_0029.html
+
+Fields Types
+0       4       8               16              24              32
++-------+-------+---------------+---------------+---------------+
+| ver   | type  | extension     | connection_id                 |
++-------+-------+---------------+---------------+---------------+
+| timestamp_microseconds                                        |
++---------------+---------------+---------------+---------------+
+| timestamp_difference_microseconds                             |
++---------------+---------------+---------------+---------------+
+| wnd_size                                                      |
++---------------+---------------+---------------+---------------+
+| seq_nr                        | ack_nr                        |
++---------------+---------------+---------------+---------------+
+
+0               8               16
++---------------+---------------+---------------+---------------+
+| extension     | len           | bitmask
++---------------+---------------+---------------+---------------+
+                                |
++---------------+---------------+....
+*/
+static int hf_bt_utp_ver = -1;
+static int hf_bt_utp_type = -1;
+static int hf_bt_utp_extension = -1;
+static int hf_bt_utp_next_extension_type = -1;
+static int hf_bt_utp_extension_len = -1;
+static int hf_bt_utp_extension_bitmask = -1;
+static int hf_bt_utp_extension_unknown = -1;
+static int hf_bt_utp_connection_id = -1;
+static int hf_bt_utp_timestamp_ms = -1;
+static int hf_bt_utp_timestamp_diff_ms = -1;
+static int hf_bt_utp_wnd_size = -1;
+static int hf_bt_utp_seq_nr = -1;
+static int hf_bt_utp_ack_nr = -1;
+
+static gint ett_bt_utp = -1;
+static gint ett_bt_utp_extension = -1;
+
+static guint global_bt_utp_udp_port = DEFAULT_UDP_PORT;
+
+void proto_reg_handoff_bt_utp(void);
+
+static int
+dissect_utp_header(tvbuff_t *tvb, proto_tree *tree)
+{
+  proto_item *ti;
+  proto_tree *ext_tree;
+  guint8 extension_type;
+  guint8 extension_length;
+  int offset = 0;
+
+  /* Strange in LibuTP the first bytes as the following definition 
+     packet_type (4 high bits)
+     protocol version (4 low bits)
+  */
+  proto_tree_add_item(tree, hf_bt_utp_ver, tvb, offset, 1, FALSE);
+  proto_tree_add_item(tree, hf_bt_utp_type, tvb, offset, 1, FALSE);
+  offset += 1;
+  proto_tree_add_item(tree, hf_bt_utp_next_extension_type, tvb, offset, 1, FALSE);
+  extension_type = tvb_get_guint8(tvb, offset);
+  offset += 1;
+  proto_tree_add_item(tree, hf_bt_utp_connection_id, tvb, offset, 2, FALSE);
+  offset += 2;
+  proto_tree_add_item(tree, hf_bt_utp_timestamp_ms, tvb, offset, 4, FALSE);
+  offset += 4;
+  proto_tree_add_item(tree, hf_bt_utp_timestamp_diff_ms, tvb, offset, 4, FALSE);
+  offset += 4;
+  proto_tree_add_item(tree, hf_bt_utp_wnd_size, tvb, offset, 4, FALSE);
+  offset += 4;
+  proto_tree_add_item(tree, hf_bt_utp_seq_nr, tvb, offset, 2, FALSE);
+  offset += 2;
+  proto_tree_add_item(tree, hf_bt_utp_ack_nr, tvb, offset, 2, FALSE);
+  offset += 2;
+
+  /* display the extension tree */
+  while(offset <= (int)tvb_length(tvb))
+  {
+    switch(extension_type){
+      case EXT_NO_EXTENSION: /* 0 */
+      {
+        ti = proto_tree_add_item(tree, hf_bt_utp_extension, tvb, offset, 1, FALSE);
+        proto_item_append_text(ti, " No Extension (End)");
+        offset += 1;
+        break;
+      }
+      case EXT_SELECTION_ACKS: /* 1 */
+      {
+        ti = proto_tree_add_item(tree, hf_bt_utp_extension, tvb, offset, -1, FALSE);
+        ext_tree = proto_item_add_subtree(ti, ett_bt_utp_extension);
+
+        proto_tree_add_item(ext_tree, hf_bt_utp_next_extension_type, tvb, offset, 1, FALSE);   
+        extension_type = tvb_get_guint8(tvb, offset);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_len, tvb, offset, 1, FALSE);   
+        extension_length = tvb_get_guint8(tvb, offset);
+        proto_item_append_text(ti, " Selection Acks, Len=%d", extension_length);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_bitmask, tvb, offset, extension_length, FALSE);
+        offset += extension_length;
+        proto_item_set_len(ti, 1 + 1 + extension_length);
+        break;
+      }
+      case EXT_EXTENSION_BITS: /* 1 */
+      {
+        ti = proto_tree_add_item(tree, hf_bt_utp_extension, tvb, offset, -1, FALSE);
+        ext_tree = proto_item_add_subtree(ti, ett_bt_utp_extension);
+
+        proto_tree_add_item(ext_tree, hf_bt_utp_next_extension_type, tvb, offset, 1, FALSE);   
+        extension_type = tvb_get_guint8(tvb, offset);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_len, tvb, offset, 1, FALSE); 
+        extension_length = tvb_get_guint8(tvb, offset);  
+        proto_item_append_text(ti, " Extension Bits, Len=%d", extension_length);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_bitmask, tvb, offset, extension_length, FALSE);
+        offset += extension_length;
+        proto_item_set_len(ti, 1 + 1 + extension_length);
+        break;
+      }
+      default:
+        ti = proto_tree_add_item(tree, hf_bt_utp_extension, tvb, offset, -1, FALSE);
+        ext_tree = proto_item_add_subtree(ti, ett_bt_utp_extension);
+
+        proto_tree_add_item(ext_tree, hf_bt_utp_next_extension_type, tvb, offset, 1, FALSE);   
+        extension_type = tvb_get_guint8(tvb, offset);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_len, tvb, offset, 1, FALSE); 
+        extension_length = tvb_get_guint8(tvb, offset);
+        proto_item_append_text(ti, " Unknown, Len=%d", extension_length);  
+        offset += 1;
+
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_unknown, tvb, offset, extension_length, FALSE);
+        offset += extension_length;
+        proto_item_set_len(ti, 1 + 1 + extension_length);
+      break;
+    }
+  }
+
+  return offset;
+}
+
+static int
+dissect_bt_utp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+  proto_item *ti;
+  proto_tree *sub_tree;
+  int decoded_length = 0;
+  /* set the protocol column */
+  col_set_str(pinfo->cinfo, COL_PROTOCOL, "BT-uTP");
+  /* set the info column */
+  col_clear(pinfo->cinfo,COL_INFO);
+
+    col_set_str( pinfo->cinfo, COL_INFO, "uTorrent Transport Protocol" );
+
+  if(tree)
+  {
+    ti = proto_tree_add_item(tree, proto_bt_utp, tvb, 0, -1, FALSE);
+    sub_tree = proto_item_add_subtree(ti, ett_bt_utp);
+    decoded_length = dissect_utp_header(tvb, sub_tree);
+  }
+  return decoded_length;
+}
+
+void
+proto_register_bt_utp(void)
+{
+  static hf_register_info hf[] = {
+    { &hf_bt_utp_ver,
+      { "Version", "bt-utp.ver",
+      FT_UINT8, BASE_DEC, NULL, 0x0F,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_type,
+      { "Type", "bt-utp.type",
+      FT_UINT8, BASE_DEC,  VALS(bt_utp_type_vals), 0xF0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_extension,
+      { "Extension", "bt-utp.extension",
+      FT_NONE, BASE_NONE, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_next_extension_type,
+      { "Next Extension Type", "bt-utp.next_extension_type",
+      FT_UINT8, BASE_DEC, VALS(bt_utp_extension_type_vals), 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_extension_len,
+      { "Extension Length", "bt-utp.extension_len",
+      FT_UINT8, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_extension_bitmask,
+      { "Extension Bitmask", "bt-utp.extension_bitmask",
+      FT_BYTES, BASE_NONE, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_extension_unknown,
+      { "Extension Unknown", "bt-utp.extension_unknown",
+      FT_BYTES, BASE_NONE, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_connection_id,
+      { "Connection ID", "bt-utp.connection_id",
+      FT_UINT16, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_timestamp_ms,
+      { "Timestamp Microseconds", "bt-utp.timestamp_ms",
+      FT_UINT32, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_timestamp_diff_ms,
+      { "Timestamp Difference Microseconds", "bt-utp.timestamp_diff_ms",
+      FT_UINT32, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_wnd_size,
+      { "Windows Size", "bt-utp.wnd_size",
+      FT_UINT32, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_seq_nr,
+      { "Sequence NR", "bt-utp.seq_nr",
+      FT_UINT16, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_ack_nr,
+      { "ACK NR", "bt-utp.ack_nr",
+      FT_UINT16, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+  };
+
+  /* Setup protocol subtree array */
+  static gint *ett[] = { &ett_bt_utp, &ett_bt_utp_extension };
+
+  module_t *bt_utp_module;
+
+  /* Register protocol */
+  proto_bt_utp = proto_register_protocol (
+			"uTorrent Transport Protocol",	/* name */
+			"BT-uTP",		/* short name */
+			"bt-utp"		/* abbrev */
+			);
+
+  proto_register_field_array(proto_bt_utp, hf, array_length(hf));
+  proto_register_subtree_array(ett, array_length(ett));
+  new_register_dissector("bt-utp", dissect_bt_utp, proto_bt_utp);
+
+  /* Register our configuration options */
+  bt_utp_module = prefs_register_protocol(proto_bt_utp, proto_reg_handoff_bt_utp);
+
+  prefs_register_uint_preference(bt_utp_module, "udp_port",
+					   "uTorrent Transport Protocol UDP port",
+					   "Set the UDP port for uTorrent Transport Protocol.",
+					   10, &global_bt_utp_udp_port);
+}
+
+void
+proto_reg_handoff_bt_utp(void)
+{
+  static gboolean bt_utp_prefs_initialized = FALSE;
+  static dissector_handle_t bt_utp_handle;
+  static guint bt_utp_udp_port;
+
+  if (!bt_utp_prefs_initialized)
+  {
+    bt_utp_handle = new_create_dissector_handle(dissect_bt_utp, proto_bt_utp);
+    bt_utp_prefs_initialized = TRUE;
+  }
+  else
+  {
+    dissector_delete_uint("udp.port", bt_utp_udp_port, bt_utp_handle);
+  }
+
+  /* Set our port number for future use */
+  bt_utp_udp_port = global_bt_utp_udp_port;
+  dissector_add_uint("udp.port", global_bt_utp_udp_port, bt_utp_handle);
+}
+/*
+ * Editor modelines
+ *
+ * Local Variables:
+ * c-basic-offset: 2
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * ex: set shiftwidth=2 tabstop=8 expandtab
+ * :indentSize=2:tabSize=8:noTabs=true:
+ */
+/* packet-bt-utp.c
+ * Routines for BT-UTP dissection
+ * Copyright 2011, Xiao Xiangquan <xiaoxiangquan@gmail.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1999 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <epan/packet.h>
+#include <epan/prefs.h>
+
+#define DEFAULT_UDP_PORT 55627
+
+static const value_string bt_utp_type_vals[] = {
+  { 0, "Data" },
+  { 1, "Fin" },
+  { 2, "State" },
+  { 3, "Reset" },
+  { 4, "Syn" },
+  { 0, NULL }
+};
+
+#define EXT_NO_EXTENSION    0
+#define EXT_SELECTION_ACKS  1
+#define EXT_EXTENSION_BITS  2
+
+static const value_string bt_utp_extension_type_vals[] = {
+  { EXT_NO_EXTENSION, "No Extension" },
+  { EXT_SELECTION_ACKS, "Selective acks" },
+  { EXT_EXTENSION_BITS, "Extension bits" },
+  { 0, NULL }
+};
+
+static int proto_bt_utp = -1;
+
+/* Specifications: BEP-0029
+http://www.bittorrent.org/beps/bep_0029.html
+
+Fields Types
+0       4       8               16              24              32
++-------+-------+---------------+---------------+---------------+
+| ver   | type  | extension     | connection_id                 |
++-------+-------+---------------+---------------+---------------+
+| timestamp_microseconds                                        |
++---------------+---------------+---------------+---------------+
+| timestamp_difference_microseconds                             |
++---------------+---------------+---------------+---------------+
+| wnd_size                                                      |
++---------------+---------------+---------------+---------------+
+| seq_nr                        | ack_nr                        |
++---------------+---------------+---------------+---------------+
+
+0               8               16
++---------------+---------------+---------------+---------------+
+| extension     | len           | bitmask
++---------------+---------------+---------------+---------------+
+                                |
++---------------+---------------+....
+*/
+static int hf_bt_utp_ver = -1;
+static int hf_bt_utp_type = -1;
+static int hf_bt_utp_extension = -1;
+static int hf_bt_utp_next_extension_type = -1;
+static int hf_bt_utp_extension_len = -1;
+static int hf_bt_utp_extension_bitmask = -1;
+static int hf_bt_utp_extension_unknown = -1;
+static int hf_bt_utp_connection_id = -1;
+static int hf_bt_utp_timestamp_ms = -1;
+static int hf_bt_utp_timestamp_diff_ms = -1;
+static int hf_bt_utp_wnd_size = -1;
+static int hf_bt_utp_seq_nr = -1;
+static int hf_bt_utp_ack_nr = -1;
+
+static gint ett_bt_utp = -1;
+static gint ett_bt_utp_extension = -1;
+
+static guint global_bt_utp_udp_port = DEFAULT_UDP_PORT;
+
+void proto_reg_handoff_bt_utp(void);
+
+static int
+dissect_utp_header(tvbuff_t *tvb, proto_tree *tree)
+{
+  proto_item *ti;
+  proto_tree *ext_tree;
+  guint8 extension_type;
+  guint8 extension_length;
+  int offset = 0;
+
+  /* Strange in LibuTP the first bytes as the following definition 
+     packet_type (4 high bits)
+     protocol version (4 low bits)
+  */
+  proto_tree_add_item(tree, hf_bt_utp_ver, tvb, offset, 1, FALSE);
+  proto_tree_add_item(tree, hf_bt_utp_type, tvb, offset, 1, FALSE);
+  offset += 1;
+  proto_tree_add_item(tree, hf_bt_utp_next_extension_type, tvb, offset, 1, FALSE);
+  extension_type = tvb_get_guint8(tvb, offset);
+  offset += 1;
+  proto_tree_add_item(tree, hf_bt_utp_connection_id, tvb, offset, 2, FALSE);
+  offset += 2;
+  proto_tree_add_item(tree, hf_bt_utp_timestamp_ms, tvb, offset, 4, FALSE);
+  offset += 4;
+  proto_tree_add_item(tree, hf_bt_utp_timestamp_diff_ms, tvb, offset, 4, FALSE);
+  offset += 4;
+  proto_tree_add_item(tree, hf_bt_utp_wnd_size, tvb, offset, 4, FALSE);
+  offset += 4;
+  proto_tree_add_item(tree, hf_bt_utp_seq_nr, tvb, offset, 2, FALSE);
+  offset += 2;
+  proto_tree_add_item(tree, hf_bt_utp_ack_nr, tvb, offset, 2, FALSE);
+  offset += 2;
+
+  /* display the extension tree */
+  while(offset <= (int)tvb_length(tvb))
+  {
+    switch(extension_type){
+      case EXT_NO_EXTENSION: /* 0 */
+      {
+        ti = proto_tree_add_item(tree, hf_bt_utp_extension, tvb, offset, 1, FALSE);
+        proto_item_append_text(ti, " No Extension (End)");
+        offset += 1;
+        break;
+      }
+      case EXT_SELECTION_ACKS: /* 1 */
+      {
+        ti = proto_tree_add_item(tree, hf_bt_utp_extension, tvb, offset, -1, FALSE);
+        ext_tree = proto_item_add_subtree(ti, ett_bt_utp_extension);
+
+        proto_tree_add_item(ext_tree, hf_bt_utp_next_extension_type, tvb, offset, 1, FALSE);   
+        extension_type = tvb_get_guint8(tvb, offset);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_len, tvb, offset, 1, FALSE);   
+        extension_length = tvb_get_guint8(tvb, offset);
+        proto_item_append_text(ti, " Selection Acks, Len=%d", extension_length);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_bitmask, tvb, offset, extension_length, FALSE);
+        offset += extension_length;
+        proto_item_set_len(ti, 1 + 1 + extension_length);
+        break;
+      }
+      case EXT_EXTENSION_BITS: /* 1 */
+      {
+        ti = proto_tree_add_item(tree, hf_bt_utp_extension, tvb, offset, -1, FALSE);
+        ext_tree = proto_item_add_subtree(ti, ett_bt_utp_extension);
+
+        proto_tree_add_item(ext_tree, hf_bt_utp_next_extension_type, tvb, offset, 1, FALSE);   
+        extension_type = tvb_get_guint8(tvb, offset);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_len, tvb, offset, 1, FALSE); 
+        extension_length = tvb_get_guint8(tvb, offset);  
+        proto_item_append_text(ti, " Extension Bits, Len=%d", extension_length);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_bitmask, tvb, offset, extension_length, FALSE);
+        offset += extension_length;
+        proto_item_set_len(ti, 1 + 1 + extension_length);
+        break;
+      }
+      default:
+        ti = proto_tree_add_item(tree, hf_bt_utp_extension, tvb, offset, -1, FALSE);
+        ext_tree = proto_item_add_subtree(ti, ett_bt_utp_extension);
+
+        proto_tree_add_item(ext_tree, hf_bt_utp_next_extension_type, tvb, offset, 1, FALSE);   
+        extension_type = tvb_get_guint8(tvb, offset);
+        offset += 1;
+        
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_len, tvb, offset, 1, FALSE); 
+        extension_length = tvb_get_guint8(tvb, offset);
+        proto_item_append_text(ti, " Unknown, Len=%d", extension_length);  
+        offset += 1;
+
+        proto_tree_add_item(ext_tree, hf_bt_utp_extension_unknown, tvb, offset, extension_length, FALSE);
+        offset += extension_length;
+        proto_item_set_len(ti, 1 + 1 + extension_length);
+      break;
+    }
+  }
+
+  return offset;
+}
+
+static int
+dissect_bt_utp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+  proto_item *ti;
+  proto_tree *sub_tree;
+  int decoded_length = 0;
+  /* set the protocol column */
+  col_set_str(pinfo->cinfo, COL_PROTOCOL, "BT-uTP");
+  /* set the info column */
+  col_clear(pinfo->cinfo,COL_INFO);
+
+    col_set_str( pinfo->cinfo, COL_INFO, "uTorrent Transport Protocol" );
+
+  if(tree)
+  {
+    ti = proto_tree_add_item(tree, proto_bt_utp, tvb, 0, -1, FALSE);
+    sub_tree = proto_item_add_subtree(ti, ett_bt_utp);
+    decoded_length = dissect_utp_header(tvb, sub_tree);
+  }
+  return decoded_length;
+}
+
+void
+proto_register_bt_utp(void)
+{
+  static hf_register_info hf[] = {
+    { &hf_bt_utp_ver,
+      { "Version", "bt-utp.ver",
+      FT_UINT8, BASE_DEC, NULL, 0x0F,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_type,
+      { "Type", "bt-utp.type",
+      FT_UINT8, BASE_DEC,  VALS(bt_utp_type_vals), 0xF0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_extension,
+      { "Extension", "bt-utp.extension",
+      FT_NONE, BASE_NONE, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_next_extension_type,
+      { "Next Extension Type", "bt-utp.next_extension_type",
+      FT_UINT8, BASE_DEC, VALS(bt_utp_extension_type_vals), 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_extension_len,
+      { "Extension Length", "bt-utp.extension_len",
+      FT_UINT8, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_extension_bitmask,
+      { "Extension Bitmask", "bt-utp.extension_bitmask",
+      FT_BYTES, BASE_NONE, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_extension_unknown,
+      { "Extension Unknown", "bt-utp.extension_unknown",
+      FT_BYTES, BASE_NONE, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_connection_id,
+      { "Connection ID", "bt-utp.connection_id",
+      FT_UINT16, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_timestamp_ms,
+      { "Timestamp Microseconds", "bt-utp.timestamp_ms",
+      FT_UINT32, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_timestamp_diff_ms,
+      { "Timestamp Difference Microseconds", "bt-utp.timestamp_diff_ms",
+      FT_UINT32, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_wnd_size,
+      { "Windows Size", "bt-utp.wnd_size",
+      FT_UINT32, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_seq_nr,
+      { "Sequence NR", "bt-utp.seq_nr",
+      FT_UINT16, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+    { &hf_bt_utp_ack_nr,
+      { "ACK NR", "bt-utp.ack_nr",
+      FT_UINT16, BASE_DEC, NULL, 0x0,
+      NULL, HFILL }
+    },
+  };
+
+  /* Setup protocol subtree array */
+  static gint *ett[] = { &ett_bt_utp, &ett_bt_utp_extension };
+
+  module_t *bt_utp_module;
+
+  /* Register protocol */
+  proto_bt_utp = proto_register_protocol (
+			"uTorrent Transport Protocol",	/* name */
+			"BT-uTP",		/* short name */
+			"bt-utp"		/* abbrev */
+			);
+
+  proto_register_field_array(proto_bt_utp, hf, array_length(hf));
+  proto_register_subtree_array(ett, array_length(ett));
+  new_register_dissector("bt-utp", dissect_bt_utp, proto_bt_utp);
+
+  /* Register our configuration options */
+  bt_utp_module = prefs_register_protocol(proto_bt_utp, proto_reg_handoff_bt_utp);
+
+  prefs_register_uint_preference(bt_utp_module, "udp_port",
+					   "uTorrent Transport Protocol UDP port",
+					   "Set the UDP port for uTorrent Transport Protocol.",
+					   10, &global_bt_utp_udp_port);
+}
+
+void
+proto_reg_handoff_bt_utp(void)
+{
+  static gboolean bt_utp_prefs_initialized = FALSE;
+  static dissector_handle_t bt_utp_handle;
+  static guint bt_utp_udp_port;
+
+  if (!bt_utp_prefs_initialized)
+  {
+    bt_utp_handle = new_create_dissector_handle(dissect_bt_utp, proto_bt_utp);
+    bt_utp_prefs_initialized = TRUE;
+  }
+  else
+  {
+    dissector_delete_uint("udp.port", bt_utp_udp_port, bt_utp_handle);
+  }
+
+  /* Set our port number for future use */
+  bt_utp_udp_port = global_bt_utp_udp_port;
+  dissector_add_uint("udp.port", global_bt_utp_udp_port, bt_utp_handle);
+}
+/*
+ * Editor modelines
+ *
+ * Local Variables:
+ * c-basic-offset: 2
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * ex: set shiftwidth=2 tabstop=8 expandtab
+ * :indentSize=2:tabSize=8:noTabs=true:
+ */