Added initial support for Dropbox LAN sync Protocol.

This is mostly to recognize the packets and a start to reverse engineer 
the currently undocumented protocol.  It's very far from complete/correct!

svn path=/trunk/; revision=32542

1 files changed, 231 insertions, 0 deletions

diff --git a/epan/dissectors/packet-db-lsp.c b/epan/dissectors/packet-db-lsp.c
new file mode 100644
index 0000000000..6f6f90214d
--- /dev/null
+++ b/epan/dissectors/packet-db-lsp.c
@@ -0,0 +1,231 @@
+/* packet-db-lsp.c
+ * Routines for Dropbox LAN sync Protocol
+ *
+ * Copyright 2010, Stig Bjorlykke <stig@bjorlykke.org>
+ *
+ * $Id$
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <glib.h>
+
+#include <epan/packet.h>
+#include <epan/asn1.h>
+#include <epan/prefs.h>
+#include <epan/expert.h>
+
+#include "packet-tcp.h"
+#include "packet-x509af.h"
+
+#define PNAME  "Dropbox LAN sync Protocol"
+#define PSNAME "DB-LSP"
+#define PFNAME "db-lsp"
+
+#define PNAME_DISC  "Dropbox LAN sync Discovery Protocol"
+#define PSNAME_DISC "DB-LSP-DISC"
+#define PFNAME_DISC "db-lsp-disc"
+
+#define DB_LSP_PORT  17500
+
+static int proto_db_lsp = -1;
+static int proto_db_lsp_disc = -1;
+
+static int hf_type = -1;
+static int hf_magic = -1;
+static int hf_length = -1;
+static int hf_value = -1;
+static int hf_text = -1;
+
+static gint ett_db_lsp = -1;
+
+/* desegmentation of tcp payload */
+static gboolean db_lsp_desegment = TRUE;
+
+static void 
+dissect_db_lsp_pdu (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+  proto_tree *db_lsp_tree;
+  proto_item *db_lsp_item;
+  gint        offset = 0;
+  guint8      type, opvalue;
+  guint16     magic, length;
+
+  col_set_str (pinfo->cinfo, COL_PROTOCOL, PSNAME);
+  col_set_str (pinfo->cinfo, COL_INFO, PNAME);
+
+  db_lsp_item = proto_tree_add_item (tree, proto_db_lsp, tvb, offset, -1, FALSE);
+  db_lsp_tree = proto_item_add_subtree (db_lsp_item, ett_db_lsp);
+  
+  type = tvb_get_guint8 (tvb, offset);
+  proto_tree_add_item (db_lsp_tree, hf_type, tvb, offset, 1, FALSE);
+  offset += 1;
+
+  if (type == 0x80) {
+    /* Two unknown bytes */
+    offset += 2;
+  }
+
+  magic = tvb_get_ntohs (tvb, offset);
+  proto_tree_add_item (db_lsp_tree, hf_magic, tvb, offset, 2, FALSE);
+  offset += 2;
+
+  length = tvb_get_ntohs (tvb, offset);
+  proto_tree_add_item (db_lsp_tree, hf_length, tvb, offset, 2, FALSE);
+  offset += 2;
+
+  if (magic != 0x0301 || length > tvb_length_remaining (tvb, offset)) {
+    /* Probably an unknown packet */
+    /* expert_add_info_format (pinfo, db_lsp_item, PI_UNDECODED, PI_WARN, "Unknown packet"); */
+    return;
+  }
+
+  opvalue = tvb_get_guint8 (tvb, offset);
+  proto_tree_add_item (db_lsp_tree, hf_value, tvb, offset, length, FALSE);
+
+  if (type == 0x16 && opvalue == 0x0B) {
+    /* X509 Certificate */
+    tvbuff_t *cert_tvb = tvb_new_subset (tvb, offset+10, length-10, length-10);
+    dissect_x509af_Certificate_PDU (cert_tvb, pinfo, db_lsp_tree);
+  }
+  offset += length;
+
+  proto_item_append_text (db_lsp_item, ", Type: %d, Length: %d", type, length);
+  proto_item_set_len (db_lsp_item, length + 5);
+}
+
+static guint 
+get_db_lsp_pdu_len (packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
+{
+  if (tvb_get_ntohs (tvb, offset + 1) != 0x0301) {
+    /* Unknown data, eat remaining data for this frame */
+    return tvb_length_remaining (tvb, offset);
+  }
+
+  return tvb_get_ntohs (tvb, offset + 3) + 5;
+}
+
+static void 
+dissect_db_lsp_tcp (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+  tcp_dissect_pdus (tvb, pinfo, tree, db_lsp_desegment, 5,
+                    get_db_lsp_pdu_len, dissect_db_lsp_pdu);
+}
+
+static void 
+dissect_db_lsp_disc (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+  proto_tree *db_lsp_tree;
+  proto_item *db_lsp_item;
+  gint        offset = 0;
+
+  col_set_str (pinfo->cinfo, COL_PROTOCOL, PSNAME_DISC);
+  col_set_str (pinfo->cinfo, COL_INFO, PNAME_DISC);
+
+  db_lsp_item = proto_tree_add_item (tree, proto_db_lsp_disc, tvb, offset, -1, FALSE);
+  db_lsp_tree = proto_item_add_subtree (db_lsp_item, ett_db_lsp);
+
+  proto_tree_add_item (db_lsp_tree, hf_text, tvb, offset, -1, FALSE);
+}
+
+void 
+proto_register_db_lsp (void)
+{ 
+  static hf_register_info hf[] = { 
+    { &hf_type,
+      { "Type", "db-lsp.type",
+        FT_UINT8, BASE_DEC_HEX, NULL, 0x0, 
+        "Type", HFILL } },
+
+    { &hf_magic,
+      { "Magic", "db-lsp.magic",
+        FT_UINT16, BASE_DEC_HEX, NULL, 0x0, 
+        "Magic number", HFILL } },
+
+    { &hf_length,
+      { "Length", "db-lsp.length",
+        FT_UINT16, BASE_DEC_HEX, NULL, 0x0, 
+        "Length in bytes", HFILL } },
+
+    { &hf_value,
+      { "Value", "db-lsp.value",
+        FT_BYTES, BASE_NONE, NULL, 0x0, 
+        NULL, HFILL } },
+
+    { &hf_text,
+      { "Text", "db-lsp.text",
+        FT_STRING, BASE_NONE, NULL, 0x0, 
+        NULL, HFILL } },
+  };
+
+  static gint *ett[] = {
+    &ett_db_lsp,
+  };
+
+  module_t *db_lsp_module;
+
+  proto_db_lsp = proto_register_protocol (PNAME, PSNAME, PFNAME);
+  proto_db_lsp_disc = proto_register_protocol (PNAME_DISC, PSNAME_DISC, PFNAME_DISC);
+  register_dissector ("db-lsp.tcp", dissect_db_lsp_tcp, proto_db_lsp);
+  register_dissector ("db-lsp.udp", dissect_db_lsp_disc, proto_db_lsp_disc);
+  
+  proto_register_field_array (proto_db_lsp, hf, array_length (hf));
+  proto_register_subtree_array (ett, array_length (ett));
+
+  /* Register our configuration options */
+  db_lsp_module = prefs_register_protocol (proto_db_lsp, NULL);
+
+  prefs_register_bool_preference (db_lsp_module, "desegment_pdus", 
+                                  "Reassemble PDUs spanning multiple TCP segments",
+                                  "Whether the LAN sync dissector should reassemble PDUs"
+                                  " spanning multiple TCP segments."
+                                  " To use this option, you must also enable \"Allow subdissectors"
+                                  " to reassemble TCP streams\" in the TCP protocol settings.",
+                                  &db_lsp_desegment);
+}
+
+void 
+proto_reg_handoff_db_lsp (void)
+{
+  dissector_handle_t db_lsp_tcp_handle;
+  dissector_handle_t db_lsp_udp_handle;
+
+  db_lsp_tcp_handle = find_dissector ("db-lsp.tcp");
+  db_lsp_udp_handle = find_dissector ("db-lsp.udp");
+
+  dissector_add ("tcp.port", DB_LSP_PORT, db_lsp_tcp_handle);
+  dissector_add ("udp.port", DB_LSP_PORT, db_lsp_udp_handle);
+}
+
+/*
+ * Editor modelines
+ *
+ * Local Variables:
+ * c-basic-offset: 2
+ * tab-width: 2
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * ex: set shiftwidth=2 tabstop=2 expandtab
+ * :indentSize=2:tabSize=2:noTabs=true:
+ */