Adding upstream version 4.2.2.upstream/4.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 864 insertions, 0 deletions

diff --git a/epan/dissectors/packet-bittorrent.c b/epan/dissectors/packet-bittorrent.c
new file mode 100644
index 00000000..2ae57017
--- /dev/null
+++ b/epan/dissectors/packet-bittorrent.c
@@ -0,0 +1,864 @@
+/* packet-bittorrent.c
+ * Routines for bittorrent packet dissection
+ * Copyright (C) 2004 Jelmer Vernooij <jelmer@samba.org>
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * Copied from packet-pop.c
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "config.h"
+
+#include <epan/packet.h>
+#include <epan/prefs.h>
+#include <epan/strutil.h>
+
+#include "packet-tcp.h"
+#include "packet-bt-utp.h"
+
+void proto_register_bittorrent(void);
+void proto_reg_handoff_bittorrent(void);
+
+/*
+ * See
+ *
+ * http://bittorrent.com/protocol.html
+ * http://wiki.theory.org/BitTorrentSpecification
+ * http://bitconjurer.org/BitTorrent/protocol.html
+ */
+
+#define DEFAULT_TCP_PORT_RANGE  "6881-6889" /* Not IANA registered */
+
+#define BITTORRENT_MESSAGE_CHOKE            0
+#define BITTORRENT_MESSAGE_UNCHOKE          1
+#define BITTORRENT_MESSAGE_INTERESTED       2
+#define BITTORRENT_MESSAGE_NOT_INTERESTED   3
+#define BITTORRENT_MESSAGE_HAVE             4
+#define BITTORRENT_MESSAGE_BITFIELD         5
+#define BITTORRENT_MESSAGE_REQUEST          6
+#define BITTORRENT_MESSAGE_PIECE            7
+#define BITTORRENT_MESSAGE_CANCEL           8
+#define BITTORRENT_MESSAGE_PORT             9
+/*
+ * BitTorrent BEP 06
+ * Fast Extension message type
+ *
+ */
+#define BITT_FAST_EX_SUGGEST_PIECE         13
+#define BITT_FAST_EX_HAVE_ALL              14
+#define BITT_FAST_EX_HAVE_NONE             15
+#define BITT_FAST_EX_REJECT_REQUEST        16
+#define BITT_FAST_EX_ALLOWED_FAST          17
+#define BITTORRENT_MESSAGE_EXTENDED        20
+
+#define BITTORRENT_HEADER_LENGTH            4
+
+/*
+ * Azureus messages are specified by name so these are made up numbers
+ * for internal identification only.
+ *
+ * Standard BT message types are a single byte, so these won't clash
+ */
+#define AZUREUS_MESSAGE_HANDSHAKE         256
+#define AZUREUS_MESSAGE_KEEP_ALIVE        257
+#define AZUREUS_MESSAGE_BT_HANDSHAKE      258
+#define AZUREUS_MESSAGE_PEER_EXCHANGE     259
+#define AZUREUS_MESSAGE_JPC_HELLO         260
+#define AZUREUS_MESSAGE_JPC_REPLY         261
+
+
+static const value_string bittorrent_messages[] = {
+   { BITTORRENT_MESSAGE_CHOKE,          "Choke" },
+   { BITTORRENT_MESSAGE_UNCHOKE,        "Unchoke" },
+   { BITTORRENT_MESSAGE_INTERESTED,     "Interested" },
+   { BITTORRENT_MESSAGE_NOT_INTERESTED, "Not Interested" },
+   { BITTORRENT_MESSAGE_HAVE,           "Have" },
+   { BITTORRENT_MESSAGE_BITFIELD,       "Bitfield" },
+   { BITTORRENT_MESSAGE_REQUEST,        "Request" },
+   { BITTORRENT_MESSAGE_PIECE,          "Piece" },
+   { BITTORRENT_MESSAGE_CANCEL,         "Cancel" },
+   { BITTORRENT_MESSAGE_PORT,           "Port" },
+   { BITT_FAST_EX_SUGGEST_PIECE,        "Suggest Piece" },
+   { BITT_FAST_EX_HAVE_ALL,             "Have All" },
+   { BITT_FAST_EX_HAVE_NONE,            "Have None" },
+   { BITT_FAST_EX_REJECT_REQUEST,       "Reject Request" },
+   { BITT_FAST_EX_ALLOWED_FAST,         "Allowed Fast" },
+   { BITTORRENT_MESSAGE_EXTENDED,       "Extended" },
+   { AZUREUS_MESSAGE_KEEP_ALIVE,        "Keepalive" },
+   { AZUREUS_MESSAGE_HANDSHAKE,         "Azureus Handshake" },
+   { AZUREUS_MESSAGE_BT_HANDSHAKE,      "Azureus BitTorrent Handshake" },
+   { AZUREUS_MESSAGE_PEER_EXCHANGE,     "Azureus Peer Exchange" },
+   { AZUREUS_MESSAGE_JPC_HELLO,         "Azureus PeerCache Hello" },
+   { AZUREUS_MESSAGE_JPC_REPLY,         "Azureus PeerCache Reply" },
+   { 0, NULL }
+};
+
+static const value_string azureus_priorities[] = {
+   { 0, "Low" },
+   { 1, "Normal" },
+   { 2, "High" },
+   { 0, NULL }
+};
+
+
+struct amp_message {
+   const char *name;
+   guint32     value;
+};
+
+static const struct amp_message amp_messages[] = {
+   { "BT_KEEP_ALIVE",    AZUREUS_MESSAGE_KEEP_ALIVE },
+   { "BT_CHOKE",         BITTORRENT_MESSAGE_CHOKE },
+   { "BT_UNCHOKE",       BITTORRENT_MESSAGE_UNCHOKE },
+   { "BT_INTERESTED",    BITTORRENT_MESSAGE_INTERESTED },
+   { "BT_UNINTERESTED",  BITTORRENT_MESSAGE_NOT_INTERESTED },
+   { "BT_HAVE",          BITTORRENT_MESSAGE_HAVE },
+   { "BT_BITFIELD",      BITTORRENT_MESSAGE_BITFIELD },
+   { "BT_REQUEST",       BITTORRENT_MESSAGE_REQUEST },
+   { "BT_PIECE",         BITTORRENT_MESSAGE_PIECE },
+   { "BT_CANCEL",        BITTORRENT_MESSAGE_CANCEL },
+   { "BT_PORT",          BITTORRENT_MESSAGE_PORT },
+   { "BT_SUGGEST",       BITT_FAST_EX_SUGGEST_PIECE },
+   { "BT_HAVE_ALL",      BITT_FAST_EX_HAVE_ALL },
+   { "BT_HAVE_NONE",     BITT_FAST_EX_HAVE_NONE },
+   { "BT_REJECT_REQUEST",BITT_FAST_EX_REJECT_REQUEST },
+   { "BT_ALLOWED_FAST",  BITT_FAST_EX_ALLOWED_FAST },
+   { "BT_EXTENDED",      BITTORRENT_MESSAGE_EXTENDED },
+   { "AZ_HANDSHAKE",     AZUREUS_MESSAGE_HANDSHAKE },
+   { "BT_HANDSHAKE",     AZUREUS_MESSAGE_BT_HANDSHAKE },
+   { "AZ_PEER_EXCHANGE", AZUREUS_MESSAGE_PEER_EXCHANGE },
+   { "JPC_HELLO",        AZUREUS_MESSAGE_JPC_HELLO },
+   { "JPC_REPLY",        AZUREUS_MESSAGE_JPC_REPLY },
+   { NULL, 0 }
+};
+
+static dissector_handle_t dissector_handle;
+static dissector_handle_t bencode_handle;
+static int proto_bittorrent = -1;
+
+/* static gint hf_bittorrent_field_length  = -1; */
+static gint hf_bittorrent_prot_name_len = -1;
+static gint hf_bittorrent_prot_name     = -1;
+static gint hf_bittorrent_reserved      = -1;
+static gint hf_bittorrent_sha1_hash     = -1;
+static gint hf_bittorrent_peer_id       = -1;
+static gint hf_bittorrent_msg           = -1;
+static gint hf_bittorrent_msg_len       = -1;
+static gint hf_bittorrent_msg_type      = -1;
+static gint hf_azureus_msg              = -1;
+static gint hf_azureus_msg_type_len     = -1;
+static gint hf_azureus_msg_type         = -1;
+static gint hf_azureus_msg_prio         = -1;
+static gint hf_bittorrent_bitfield_data = -1;
+static gint hf_bittorrent_piece_index   = -1;
+static gint hf_bittorrent_piece_begin   = -1;
+static gint hf_bittorrent_piece_length  = -1;
+static gint hf_bittorrent_piece_data    = -1;
+static gint hf_azureus_jpc_addrlen      = -1;
+static gint hf_azureus_jpc_addr         = -1;
+static gint hf_azureus_jpc_port         = -1;
+static gint hf_azureus_jpc_session      = -1;
+static gint hf_bittorrent_port          = -1;
+static gint hf_bittorrent_extended_id   = -1;
+static gint hf_bittorrent_extended      = -1;
+static gint hf_bittorrent_continuous_data = -1;
+static gint hf_bittorrent_version       = -1;
+
+static gint ett_bittorrent              = -1;
+static gint ett_bittorrent_msg          = -1;
+static gint ett_peer_id                 = -1;
+
+static gboolean bittorrent_desegment      = TRUE;
+static gboolean decode_client_information = FALSE;
+
+struct client_information {
+   char        id[5];     /* string length must be <= 4 to allow space for NUL termination byte */
+   char        ver_len;
+   const char *name;      /* NULL means array entry terminates the array */
+};
+
+static struct client_information peer_id[] = {
+   {"-AG",  4, "Ares"},
+   {"-A~",  4, "Ares"},
+   {"-AR",  4, "Arctic"},
+   {"-AT",  4, "Artemis"},
+   {"-AV",  4, "Avicora"},
+   {"-AX",  4, "BitPump"},
+   {"-AZ",  4, "Azureus"},
+   {"-BB",  4, "BitBuddy"},
+   {"-BC",  4, "BitComet"},
+   {"-BF",  4, "Bitflu"},
+   {"-BG",  4, "BTG (uses Rasterbar libtorrent)"},
+   {"-BOW", 3, "Bits on Wheels"},
+   {"-BP",  4, "BitTorrent Pro (Azereus + spyware)"},
+   {"-BR",  4, "BitRocket"},
+   {"-BS",  4, "BTSlave"},
+   {"-BW",  4, "BitWombat"},
+   {"-BX",  4, "Bittorrent X"},
+   {"-CD",  4, "Enhanced CTorrent"},
+   {"-CT",  4, "CTorrent"},
+   {"-DE",  4, "DelugeTorrent"},
+   {"-DP",  4, "Propagate Data Client"},
+   {"-EB",  4, "EBit"},
+   {"-ES",  4, "electric sheep"},
+   {"-FC",  4, "FileCroc"},
+   {"-FG",  4, "FlashGet"},
+   {"-FT",  4, "FoxTorrent"},
+   {"-GS",  4, "GSTorrent"},
+   {"-HK",  4, "Hekate"},
+   {"-HL",  4, "Halite"},
+   {"-HN",  4, "Hydranode"},
+   {"-KG",  4, "KGet"},
+   {"-KT",  4, "KTorrent"},
+   {"-LC",  4, "LeechCraft"},
+   {"-LH",  4, "LH-ABC"},
+   {"-LP",  4, "Lphant"},
+   {"-LT",  4, "libtorrent"},
+   {"-lt",  4, "libTorrent"},
+   {"-LW",  4, "LimeWire"},
+   {"-MO",  4, "MonoTorrent"},
+   {"-MP",  4, "MooPolice"},
+   {"-MR",  4, "Miro"},
+   {"-MT",  4, "MoonlightTorrent"},
+   {"-NE",  4, "BT Next Evolution"},
+   {"-NX",  4, "Net Transport"},
+   {"-OS",  4, "OneSwarm"},
+   {"-OT",  4, "OmegaTorrent"},
+   {"-PD",  4, "Pando"},
+   {"-qB",  4, "qBittorrent"},
+   {"-QD",  4, "QQDownload"},
+   {"-QT",  4, "Qt 4 Torrent example"},
+   {"-RT",  4, "Retriever"},
+   {"-S~",  4, "Shareaza alpha/beta"},
+   {"-SB",  4, "Swiftbit"},
+   {"-SD",  4, "Thunder (aka XunLei)"},
+   {"-SS",  4, "SwarmScope"},
+   {"-ST",  4, "SymTorrent"},
+   {"-st",  4, "sharktorrent"},
+   {"-SZ",  4, "Shareaza"},
+   {"-TN",  4, "TorrentDotNET"},
+   {"-TR",  4, "Transmission"},
+   {"-TS",  4, "Torrentstorm"},
+   {"-TT",  4, "TuoTu"},
+   {"-UL",  4, "uLeecher!"},
+   {"-UM",  4, "(my)Torrent for Mac"},
+   {"-UT",  4, "(my)Torrent"},
+   {"-VG",  4, "Vagaa"},
+   {"-WT",  4, "BitLet"},
+   {"-WY",  4, "FireTorrent"},
+   {"-XL",  4, "Xunlei"},
+   {"-XT",  4, "XanTorrent"},
+   {"-XX",  4, "Xtorrent"},
+   {"-ZT",  4, "ZipTorrent"},
+   {"exbc", 2, "BitComet"},
+   {"OP",   4, "Opera"},
+   {"QVOD", 4, "Qvod"},
+   {"XBT",  3, "XBT Client"},
+   {"A",    3, "ABC"},
+   {"O",    3, "Osprey Permaseed"},
+   {"Q",    3, "BTQueue"},
+   {"R",    3, "Tribler"},
+   {"S",    3, "Shadow's client"},
+   {"T",    3, "BitTornado"},
+   {"U",    3, "UPnP NAT Bit Torrent"},
+   {"",     0, NULL}
+};
+
+/* Tests a given length for a message type to see if it looks valid.
+ * The exact length is known for many message types, which prevents us
+ * from returning a false positive match based on a single byte when
+ * we're in the middle of Continuation Data or an encrypted transfer.
+ */
+static gboolean
+test_type_length(guint16 type, guint32 length)
+{
+   switch (type) {
+
+   case BITTORRENT_MESSAGE_UNCHOKE:
+   case BITTORRENT_MESSAGE_INTERESTED:
+   case BITTORRENT_MESSAGE_NOT_INTERESTED:
+   case BITT_FAST_EX_HAVE_ALL:
+   case BITT_FAST_EX_HAVE_NONE:
+      /* No payload */
+      if (length != 1) {
+         return FALSE;
+      }
+      return TRUE;
+      break;
+
+   case BITTORRENT_MESSAGE_PORT:
+      if (length != 3) {
+         return FALSE;
+      }
+      return TRUE;
+      break;
+
+   case BITTORRENT_MESSAGE_HAVE:
+   case BITT_FAST_EX_SUGGEST_PIECE:
+   case BITT_FAST_EX_ALLOWED_FAST:
+      if (length != 5) {
+         return FALSE;
+      }
+      return TRUE;
+      break;
+
+   case BITTORRENT_MESSAGE_REQUEST:
+   case BITTORRENT_MESSAGE_CANCEL:
+   case BITT_FAST_EX_REJECT_REQUEST:
+      if (length != 13) {
+         return FALSE;
+      }
+      return TRUE;
+      break;
+
+   /* Now to the messages that can have variable and longer lengths. */
+
+   case BITTORRENT_MESSAGE_EXTENDED:
+   case BITTORRENT_MESSAGE_PIECE:
+      /* All known implementations use 0x4000 for the piece length by default
+       * (only smaller for the last piece at EOF), and disconnect from clients
+       * that use a larger value, which is mentioned in BEP-3. Including the
+       * other parts of the message, that yields a length of 0x4009. There
+       * might exist some non-standard traffic somewhere, I suppose.
+       *
+       * This is excessively long for any extension message.
+       */
+      if (length > 0x4009) {
+         return FALSE;
+      }
+      return TRUE;
+      break;
+
+   case BITTORRENT_MESSAGE_CHOKE:
+      /* Choke could be an Azureus message instead, which could be any
+       * of the other messages, so it has to be as long as our longest
+       * message. XXX: To reduce false positives (since 0 is a common
+       * byte to see), a pref to disable Azureus support could be useful.
+       * Alternatively, if we tracked conversations, we could disable
+       * support for AMP if the extension bits in the handshake (if seen)
+       * indicated that it's not supported.
+       */
+   case AZUREUS_MESSAGE_HANDSHAKE:
+   case AZUREUS_MESSAGE_KEEP_ALIVE:
+   case AZUREUS_MESSAGE_BT_HANDSHAKE:
+   case AZUREUS_MESSAGE_PEER_EXCHANGE:
+   case AZUREUS_MESSAGE_JPC_HELLO:
+   case AZUREUS_MESSAGE_JPC_REPLY:
+   case BITTORRENT_MESSAGE_BITFIELD:
+      /* A bitfield length is N bits, where N is the number of pieces
+       * in the torrent. The absolute boundary is 2^32 pieces (because
+       * it has to fit in the piece message). In practice the piece
+       * length varies to balance a number of factors. (Some clients
+       * don't work with too many pieces; at one point 2^16 was a common
+       * maximum.) The minimum common piece length is 2^18 bytes, and higher
+       * powers of two are also frequently used.
+       *
+       * 0x20000 allows 0x100000 pieces, or over a million. That's more
+       * than most clients support, and cuts down on false positives.
+       */
+      if (length > 0x20000) {
+         return FALSE;
+      }
+      return TRUE;
+      break;
+
+   default:
+      if (!try_val_to_str(type, bittorrent_messages)) {
+         return FALSE;
+      }
+   }
+
+   return TRUE;
+}
+
+static guint
+get_bittorrent_pdu_length(packet_info *pinfo _U_, tvbuff_t *tvb,
+                          int offset, void *data _U_)
+{
+   guint8  type;
+   guint32 length;
+
+   if (tvb_get_guint8(tvb, offset) == 19 &&
+       tvb_memeql(tvb, offset + 1, (const guint8*)"BitTorrent protocol", 19) == 0) {
+      /* Return the length of a Handshake message */
+      return  1 + /* pstrlen */
+             19 + /* pstr */
+              8 + /* reserved */
+             20 + /* SHA1 hash of the info key */
+             20;  /* peer id */
+   } else {
+      /* Try to validate the length of the message indicated by the header. */
+      length = tvb_get_ntohl(tvb, offset);
+      if(length == 0) {
+        /* keep-alive - no message ID */
+        return BITTORRENT_HEADER_LENGTH;
+      }
+      /* Do some sanity checking of the message, if we have the ID byte */
+      if(tvb_offset_exists(tvb, offset + BITTORRENT_HEADER_LENGTH)) {
+         type = tvb_get_guint8(tvb, offset + BITTORRENT_HEADER_LENGTH);
+         if (test_type_length(type, length)) {
+            /* This seems to be a valid BitTorrent header with a known
+               type identifier and valid length */
+            return BITTORRENT_HEADER_LENGTH + length;
+         } else {
+            /* The type is not known, so this message cannot be decoded
+               properly by this dissector.  We assume it's continuation
+               data from the middle of a message, and just return the
+               remaining length in the tvbuff so the rest of the tvbuff
+               is displayed as continuation data. */
+            return tvb_reported_length_remaining(tvb, offset);
+         }
+      } else {
+         /* We don't have the type field, so we can't determine
+            whether this is a valid message.  For now, we assume
+            it's continuation data from the middle of a message,
+            and just return the remaining length in the tvbuff so
+            the rest of the tvbuff is displayed as continuation
+            data. */
+         return tvb_reported_length_remaining(tvb, offset);
+      }
+   }
+}
+
+static void
+dissect_bittorrent_message (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+   int         offset  = 0;
+   int         i;
+   int         isamp   = 0;
+   proto_tree *mtree;
+   guint16     type    = 0;
+   guint32     typelen = 0;
+   guint8      prio    = 0;
+   guint32     ext_id  = 0;
+   guint32     length;
+   const char *msgtype = NULL;
+   proto_item *ti;
+   guint32     piece_index, piece_begin, piece_length;
+   guint32     stringlen;
+   tvbuff_t   *subtvb;
+
+   if (tvb_bytes_exist(tvb, offset + BITTORRENT_HEADER_LENGTH, 1)) {
+      /* Check for data from the middle of a message. */
+      length = tvb_get_ntohl(tvb, offset);
+      type = tvb_get_guint8(tvb, offset + BITTORRENT_HEADER_LENGTH);
+
+      if (type==BITTORRENT_MESSAGE_CHOKE && length>4) {
+         /*
+          * Choke messages have no payload, so this is likely an Azureus
+          * Messaging Protocol packet
+          */
+         if (!tvb_bytes_exist(tvb, offset + BITTORRENT_HEADER_LENGTH, 4))
+            return;
+
+         typelen = tvb_get_ntohl(tvb, offset + BITTORRENT_HEADER_LENGTH);
+         if (4+typelen+1<=length) {
+            if (!tvb_bytes_exist(tvb, offset + BITTORRENT_HEADER_LENGTH + 4, typelen+1))
+               return;
+
+            for ( i=0 ; amp_messages[i].name ; i++ ) {
+               if (strlen(amp_messages[i].name)==typelen &&
+                   tvb_memeql(tvb, offset + BITTORRENT_HEADER_LENGTH + 4,
+                              amp_messages[i].name, (int)strlen(amp_messages[i].name))==0) {
+
+                  prio = tvb_get_guint8(tvb, offset + BITTORRENT_HEADER_LENGTH + 4 + typelen);
+                  if (prio==0 || prio==1 || prio==2) {
+                     type = amp_messages[i].value;
+                     isamp = 1;
+                  }
+                  break;
+               }
+            }
+         }
+      }
+
+      msgtype = try_val_to_str(type, bittorrent_messages);
+#if 0
+      if (msgtype == NULL && isamp) {
+         msgtype = try_val_to_str(type, azureus_messages);
+      }
+#endif
+      if (msgtype == NULL || !(test_type_length(type, length))) {
+         /* In modern captures, this is likely Protocol Encryption/
+          * Message Stream Encryption, particularly if we're actually
+          * desegmenting and have the whole connection starting from
+          * the SYN. We don't try to do that yet.
+          */
+         proto_tree_add_item(tree, hf_bittorrent_continuous_data, tvb, offset, -1, ENC_NA);
+         col_set_str(pinfo->cinfo, COL_INFO, "Continuation data");
+         return;
+      }
+   } else {
+      /* not enough bytes of the header, stop here */
+      return;
+   }
+
+   if (isamp) {
+      ti = proto_tree_add_item(tree, hf_azureus_msg, tvb, offset, length + BITTORRENT_HEADER_LENGTH, ENC_NA);
+   } else {
+      ti = proto_tree_add_item(tree, hf_bittorrent_msg, tvb, offset, length + BITTORRENT_HEADER_LENGTH, ENC_NA);
+   }
+   mtree = proto_item_add_subtree(ti, ett_bittorrent_msg);
+
+   /* Keepalive message */
+   if (length == 0) {
+      proto_tree_add_item(mtree, hf_bittorrent_msg_len, tvb, offset, BITTORRENT_HEADER_LENGTH, ENC_BIG_ENDIAN);
+      col_set_str(pinfo->cinfo, COL_INFO, "KeepAlive");
+      return;
+   }
+
+   proto_tree_add_item(mtree, hf_bittorrent_msg_len, tvb, offset, BITTORRENT_HEADER_LENGTH, ENC_BIG_ENDIAN);
+   offset += BITTORRENT_HEADER_LENGTH;
+
+   /* If the tvb_bytes_exist() call above returned FALSE, this will
+      throw an exception, so we won't use msgtype or type. */
+   if (isamp) {
+      proto_tree_add_item(mtree, hf_azureus_msg_type_len, tvb, offset, 4, ENC_BIG_ENDIAN);
+      proto_tree_add_item(mtree, hf_azureus_msg_type, tvb, offset+4, typelen, ENC_ASCII);
+      proto_item_append_text(ti, ": Len %u, %s", length, msgtype);
+      proto_tree_add_item(mtree, hf_azureus_msg_prio, tvb, offset+4+typelen, 1, ENC_BIG_ENDIAN);
+      offset += 4+typelen+1;
+      length -= 4+typelen+1;
+   } else {
+      proto_tree_add_item(mtree, hf_bittorrent_msg_type, tvb, offset, 1, ENC_BIG_ENDIAN);
+      proto_item_append_text(ti, ": Len:%u, %s", length, msgtype);
+      offset += 1;
+      length -= 1;
+   }
+   col_set_str(pinfo->cinfo, COL_INFO, msgtype);
+
+   switch (type) {
+   case BITTORRENT_MESSAGE_CHOKE:
+   case BITTORRENT_MESSAGE_UNCHOKE:
+   case BITTORRENT_MESSAGE_INTERESTED:
+   case BITTORRENT_MESSAGE_NOT_INTERESTED:
+   case BITT_FAST_EX_HAVE_ALL:
+   case BITT_FAST_EX_HAVE_NONE:
+      /* No payload */
+      break;
+
+   case BITTORRENT_MESSAGE_REQUEST:
+   case BITTORRENT_MESSAGE_CANCEL:
+   case BITT_FAST_EX_REJECT_REQUEST:
+      piece_index = tvb_get_ntohl(tvb, offset);
+      proto_tree_add_uint(mtree, hf_bittorrent_piece_index, tvb, offset, 4, piece_index); offset += 4;
+      piece_begin = tvb_get_ntohl(tvb, offset);
+      proto_tree_add_uint(mtree, hf_bittorrent_piece_begin, tvb, offset, 4, piece_begin); offset += 4;
+      piece_length = tvb_get_ntohl(tvb, offset);
+      proto_tree_add_uint(mtree, hf_bittorrent_piece_length, tvb, offset, 4, piece_length);
+      proto_item_append_text(ti, ", Piece (Idx:0x%x,Begin:0x%x,Len:0x%x)", piece_index, piece_begin, piece_length);
+
+      col_append_fstr(pinfo->cinfo, COL_INFO, ", Piece (Idx:0x%x,Begin:0x%x,Len:0x%x)", piece_index, piece_begin, piece_length);
+
+      break;
+
+   case BITTORRENT_MESSAGE_PORT:
+      /* port as payload */
+      proto_tree_add_item(mtree, hf_bittorrent_port, tvb, offset, 2, ENC_BIG_ENDIAN);
+      break;
+
+   case BITTORRENT_MESSAGE_EXTENDED:
+      /* extended message content */
+      proto_tree_add_item_ret_uint(mtree, hf_bittorrent_extended_id, tvb, offset, 1, ENC_NA, &ext_id);
+      offset += 1;
+      length -= 1;
+      if (ext_id == 0) {
+         call_dissector(bencode_handle, tvb_new_subset_length(tvb, offset, length), pinfo, mtree);
+      } else {
+         proto_tree_add_item(mtree, hf_bittorrent_extended, tvb, offset, length, ENC_NA);
+      }
+      break;
+
+   case BITTORRENT_MESSAGE_HAVE:
+   case BITT_FAST_EX_SUGGEST_PIECE:
+   case BITT_FAST_EX_ALLOWED_FAST:
+      piece_index = tvb_get_ntohl(tvb, offset);
+      proto_tree_add_item(mtree, hf_bittorrent_piece_index, tvb, offset, 4, ENC_BIG_ENDIAN);
+      proto_item_append_text(ti, ", Piece (Idx:0x%x)", piece_index);
+
+      col_append_fstr(pinfo->cinfo, COL_INFO, ", Piece (Idx:0x%x)", piece_index);
+
+      break;
+
+   case BITTORRENT_MESSAGE_BITFIELD:
+      proto_tree_add_item(mtree, hf_bittorrent_bitfield_data, tvb, offset, length, ENC_NA);
+      proto_item_append_text(ti, ", Len:0x%x", length);
+      col_append_fstr(pinfo->cinfo, COL_INFO, ", Len:0x%x", length);
+
+      break;
+
+   case BITTORRENT_MESSAGE_PIECE:
+      piece_index = tvb_get_ntohl(tvb, offset);
+      proto_tree_add_uint(mtree, hf_bittorrent_piece_index, tvb, offset, 4, piece_index);
+      offset += 4;
+      length -= 4;
+      piece_begin = tvb_get_ntohl(tvb, offset);
+      proto_tree_add_uint(mtree, hf_bittorrent_piece_begin, tvb, offset, 4, piece_begin);
+      offset += 4;
+      length -= 4;
+      proto_tree_add_item(mtree, hf_bittorrent_piece_data, tvb, offset, length, ENC_NA);
+      proto_item_append_text(ti, ", Idx:0x%x,Begin:0x%x,Len:0x%x", piece_index, piece_begin, length);
+      col_append_fstr(pinfo->cinfo, COL_INFO, ", Idx:0x%x,Begin:0x%x,Len:0x%x", piece_index, piece_begin, length);
+
+      break;
+
+   case AZUREUS_MESSAGE_HANDSHAKE:
+   case AZUREUS_MESSAGE_PEER_EXCHANGE:
+      subtvb = tvb_new_subset_length(tvb, offset, length);
+      call_dissector(bencode_handle, subtvb, pinfo, mtree);
+      break;
+
+   case AZUREUS_MESSAGE_JPC_HELLO:
+      stringlen = tvb_get_ntohl(tvb, offset);
+      proto_tree_add_item(mtree, hf_azureus_jpc_addrlen, tvb, offset, 4, ENC_BIG_ENDIAN);
+      proto_tree_add_item(mtree, hf_azureus_jpc_addr, tvb, offset+4, stringlen, ENC_ASCII);
+      proto_tree_add_item(mtree, hf_azureus_jpc_port, tvb, offset+4+stringlen, 4, ENC_BIG_ENDIAN);
+      proto_tree_add_item(mtree, hf_azureus_jpc_session, tvb, offset+4+stringlen+4, 4, ENC_BIG_ENDIAN);
+      break;
+
+   case AZUREUS_MESSAGE_JPC_REPLY:
+      proto_tree_add_item(mtree, hf_azureus_jpc_session, tvb, offset, 4, ENC_BIG_ENDIAN);
+      break;
+
+   default:
+      break;
+   }
+}
+
+static int
+dissect_bittorrent_welcome (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+   int   offset = 0;
+   int   i;
+   char *version;
+
+   col_set_str(pinfo->cinfo, COL_INFO, "Handshake");
+
+   proto_tree_add_item(tree, hf_bittorrent_prot_name_len, tvb, offset, 1, ENC_BIG_ENDIAN); offset+=1;
+   proto_tree_add_item(tree, hf_bittorrent_prot_name, tvb, offset, 19, ENC_ASCII); offset += 19;
+   proto_tree_add_item(tree, hf_bittorrent_reserved, tvb, offset, 8, ENC_NA); offset += 8;
+
+   proto_tree_add_item(tree, hf_bittorrent_sha1_hash, tvb, offset, 20, ENC_NA);
+   offset += 20;
+
+   proto_tree_add_item(tree, hf_bittorrent_peer_id, tvb, offset, 20, ENC_NA);
+   if(decode_client_information) {
+      for(i = 0; peer_id[i].name != NULL; ++i)
+      {
+         if(tvb_memeql(tvb, offset, (const guint8*)peer_id[i].id, (int)strlen(peer_id[i].id)) == 0) {
+            version = tvb_get_string_enc(pinfo->pool, tvb, offset + (int)strlen(peer_id[i].id),
+                                     peer_id[i].ver_len, ENC_ASCII);
+            proto_tree_add_string_format(tree, hf_bittorrent_version, tvb, offset, 20, version, "Client is %s v%s",
+                                peer_id[i].name, format_text(pinfo->pool, (guchar*)version, peer_id[i].ver_len));
+            break;
+         }
+      }
+   }
+   offset += 20;
+   return offset;
+}
+
+static
+int dissect_bittorrent_tcp_pdu (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
+{
+   proto_item *ti;
+
+   col_set_str(pinfo->cinfo, COL_PROTOCOL, "BitTorrent");
+
+   col_set_str(pinfo->cinfo, COL_INFO, "BitTorrent ");
+
+   ti = proto_tree_add_item (tree, proto_bittorrent, tvb, 0, -1, ENC_NA);
+   tree = proto_item_add_subtree(ti, ett_bittorrent);
+
+   if (tvb_get_guint8(tvb, 0) == 19 &&
+       tvb_memeql(tvb, 1, (const guint8*)"BitTorrent protocol", 19) == 0) {
+      dissect_bittorrent_welcome(tvb, pinfo, tree);
+   } else {
+      dissect_bittorrent_message(tvb, pinfo, tree);
+   }
+
+    col_append_str(pinfo->cinfo, COL_INFO, "  ");
+    col_set_fence(pinfo->cinfo, COL_INFO);
+
+    return tvb_reported_length(tvb);
+}
+
+static
+int dissect_bittorrent (tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
+{
+   tcp_dissect_pdus(tvb, pinfo, tree, bittorrent_desegment, BITTORRENT_HEADER_LENGTH,
+                    get_bittorrent_pdu_length, dissect_bittorrent_tcp_pdu, data);
+   return tvb_reported_length(tvb);
+}
+
+static
+int dissect_bittorrent_utp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
+{
+   utp_dissect_pdus(tvb, pinfo, tree, bittorrent_desegment, BITTORRENT_HEADER_LENGTH,
+                    get_bittorrent_pdu_length, dissect_bittorrent_tcp_pdu, data);
+   return tvb_reported_length(tvb);
+}
+
+static
+gboolean test_bittorrent_packet (tvbuff_t *tvb, packet_info *pinfo,
+                                 proto_tree *tree, void *data)
+{
+   conversation_t *conversation;
+
+   if (tvb_captured_length(tvb) >= 20 &&
+       tvb_get_guint8(tvb, 0) == 19 &&
+       tvb_memeql(tvb, 1, (const guint8*)"BitTorrent protocol", 19) == 0) {
+      conversation = find_or_create_conversation(pinfo);
+      conversation_set_dissector(conversation, dissector_handle);
+
+      dissect_bittorrent(tvb, pinfo, tree, data);
+
+      return TRUE;
+   }
+
+   return FALSE;
+}
+
+void
+proto_register_bittorrent(void)
+{
+   static hf_register_info hf[] = {
+#if 0
+      { &hf_bittorrent_field_length,
+        { "Field Length", "bittorrent.length", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }
+      },
+#endif
+      { &hf_bittorrent_prot_name_len,
+        { "Protocol Name Length", "bittorrent.protocol.name.length", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_prot_name,
+        { "Protocol Name", "bittorrent.protocol.name", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_reserved,
+        { "Reserved Extension Bytes", "bittorrent.reserved", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_sha1_hash,
+        { "SHA1 Hash of info dictionary", "bittorrent.info_hash", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_peer_id,
+        { "Peer ID", "bittorrent.peer_id", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_msg,
+        { "Message", "bittorrent.msg", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_msg_len,
+        { "Message Length", "bittorrent.msg.length", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_msg_type,
+        { "Message Type", "bittorrent.msg.type", FT_UINT8, BASE_DEC, VALS(bittorrent_messages), 0x0, NULL, HFILL }
+      },
+      { &hf_azureus_msg,
+        { "Azureus Message", "bittorrent.azureus_msg", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_azureus_msg_type_len,
+        { "Message Type Length", "bittorrent.msg.typelen", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_azureus_msg_type,
+        { "Message Type", "bittorrent.msg.aztype", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_azureus_msg_prio,
+        { "Message Priority", "bittorrent.msg.prio", FT_UINT8, BASE_DEC, VALS(azureus_priorities), 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_bitfield_data,
+        { "Bitfield data", "bittorrent.msg.bitfield", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_piece_index,
+        { "Piece index", "bittorrent.piece.index", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_piece_begin,
+        { "Begin offset of piece", "bittorrent.piece.begin", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_piece_data,
+        { "Data in a piece", "bittorrent.piece.data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_piece_length,
+        { "Piece Length", "bittorrent.piece.length", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_azureus_jpc_addrlen,
+        { "Cache Address Length", "bittorrent.jpc.addr.length", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_azureus_jpc_addr,
+        { "Cache Address", "bittorrent.jpc.addr", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_azureus_jpc_port,
+        { "Port", "bittorrent.jpc.port", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_azureus_jpc_session,
+        { "Session ID", "bittorrent.jpc.session", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_port,
+        { "Port", "bittorrent.port", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_extended_id,
+        { "Extended Message ID", "bittorrent.extended.id", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_extended,
+        { "Extended Message", "bittorrent.extended", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_continuous_data,
+        { "Extended Message", "bittorrent.continuous_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+      { &hf_bittorrent_version,
+        { "Client version", "bittorrent.version", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }
+      },
+   };
+
+   static gint *ett[] = {
+      &ett_bittorrent,
+      &ett_bittorrent_msg,
+      &ett_peer_id,
+   };
+
+   module_t *bittorrent_module;
+
+   proto_bittorrent = proto_register_protocol("BitTorrent", "BitTorrent", "bittorrent");
+   proto_register_field_array(proto_bittorrent, hf, array_length(hf));
+   proto_register_subtree_array(ett, array_length(ett));
+
+   dissector_handle = register_dissector("bittorrent.tcp", dissect_bittorrent, proto_bittorrent);
+   register_dissector("bittorrent.utp", dissect_bittorrent_utp, proto_bittorrent);
+
+   bittorrent_module = prefs_register_protocol(proto_bittorrent, NULL);
+   prefs_register_bool_preference(bittorrent_module, "desegment",
+                                  "Reassemble BitTorrent messages spanning multiple TCP segments",
+                                  "Whether the BitTorrent dissector should reassemble messages spanning multiple TCP segments."
+                                  " To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
+                                  &bittorrent_desegment);
+   prefs_register_bool_preference(bittorrent_module, "decode_client",
+                                  "Decode the peer_id of the handshake messages",
+                                  "Enabling this will tell which BitTorrent client that produced the handshake message",
+                                  &decode_client_information);
+}
+
+
+void
+proto_reg_handoff_bittorrent(void)
+{
+   bencode_handle = find_dissector_add_dependency("bencode", proto_bittorrent);
+
+   dissector_add_uint_range_with_preference("tcp.port", DEFAULT_TCP_PORT_RANGE, dissector_handle);
+
+   heur_dissector_add("tcp", test_bittorrent_packet, "BitTorrent over TCP", "bittorrent_tcp", proto_bittorrent, HEURISTIC_ENABLE);
+}
+
+/*
+ * Editor modelines
+ *
+ * Local Variables:
+ * c-basic-offset: 3
+ * tab-width: 8
+ * indent-tabs-mode: nil
+ * End:
+ *
+ * ex: set shiftwidth=3 tabstop=8 expandtab:
+ * :indentSize=3:tabSize=8:noTabs=true:
+ */