/* packet-bittorrent.c * Routines for bittorrent packet dissection * Copyright (C) 2004 Jelmer Vernooij * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * Copied from packet-pop.c * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "config.h" #include #include #include #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: */