diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-10 20:34:10 +0000 |
commit | e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc (patch) | |
tree | 68cb5ef9081156392f1dd62a00c6ccc1451b93df /epan/dissectors/packet-turnchannel.c | |
parent | Initial commit. (diff) | |
download | wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.tar.xz wireshark-e4ba6dbc3f1e76890b22773807ea37fe8fa2b1bc.zip |
Adding upstream version 4.2.2.upstream/4.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'epan/dissectors/packet-turnchannel.c')
-rw-r--r-- | epan/dissectors/packet-turnchannel.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/epan/dissectors/packet-turnchannel.c b/epan/dissectors/packet-turnchannel.c new file mode 100644 index 0000000..e575343 --- /dev/null +++ b/epan/dissectors/packet-turnchannel.c @@ -0,0 +1,235 @@ +/* packet-turnchannel.c + * Routines for TURN channel dissection (TURN negociation is handled + * in the STUN2 dissector + * Copyright 2008, 8x8 Inc. <petithug@8x8.com> + * + * Wireshark - Network traffic analyzer + * By Gerald Combs <gerald@wireshark.org> + * Copyright 1998 Gerald Combs + * + * SPDX-License-Identifier: GPL-2.0-or-later + * + * Please refer to the following specs for protocol detail: + * - draft-ietf-behave-rfc3489bis-15 + * - draft-ietf-mmusic-ice-19 + * - draft-ietf-behave-nat-behavior-discovery-03 + * - draft-ietf-behave-turn-07 + * - draft-ietf-behave-turn-ipv6-03 + * + * XXX - these are now: + * - RFC 5389 + * - RFC 5245 + * - RFC 5780 + * - RFC 5766 + * - RFC 6156 + * - RFC 8656 + * + * Update as necessary. + */ + +#include "config.h" + +#include <epan/packet.h> +#include "packet-tcp.h" + +void proto_register_turnchannel(void); +void proto_reg_handoff_turnchannel(void); + +/* heuristic subdissectors */ +static heur_dissector_list_t heur_subdissector_list; + +/* Initialize the protocol and registered fields */ +static int proto_turnchannel = -1; + +static int hf_turnchannel_id = -1; +static int hf_turnchannel_len = -1; + +#define TURNCHANNEL_HDR_LEN ((guint)4) + +#define MS_MULTIPLEX_TURN 0xFF10 + +/* Initialize the subtree pointers */ +static gint ett_turnchannel = -1; + +static dissector_handle_t turnchannel_tcp_handle; +static dissector_handle_t turnchannel_udp_handle; + +/* + * RFC 5764 defined a demultiplexing scheme to allow TURN is co-exist + * on the same 5-tuple as STUN, DTLS, RTP/RTCP, and ZTLS by rejecting + * previous reserved channel numbers, restricting the channel numbers + * to 0x4000-0x7FFF. RFC 5766 (TURN) did not incorporate the restriction, + * but RFC 8656 did, further restricting the channel numbers to the + * range 0x4000-0x4FFF. + * + * Reject channel numbers outside 0x4000-0x7FFF (except for the special + * MS-TURN multiplex channel number), since no implementation has used + * any value outside that range, and the 0x5000-0x7FFF range is reserved + * in the multiplexing scheme. + */ +static gboolean +test_turnchannel_id(guint16 channel_id) +{ + if ((channel_id & 0x4000) == 0x4000 || channel_id == MS_MULTIPLEX_TURN) + return TRUE; + + return FALSE; +} + +static int +dissect_turnchannel_message(tvbuff_t *tvb, packet_info *pinfo, + proto_tree *tree, void *data _U_) +{ + guint len; + guint16 channel_id; + guint16 data_len; + proto_item *ti; + proto_tree *turnchannel_tree; + heur_dtbl_entry_t *hdtbl_entry; + + len = tvb_captured_length(tvb); + /* First, make sure we have enough data to do the check. */ + if (len < TURNCHANNEL_HDR_LEN) { + return 0; + } + + channel_id = tvb_get_ntohs(tvb, 0); + data_len = tvb_get_ntohs(tvb, 2); + + if (!test_turnchannel_id(channel_id)) { + return 0; + } + + if (len != TURNCHANNEL_HDR_LEN + data_len) { + return 0; + } + + /* Seems to be a decent TURN channel message */ + col_set_str(pinfo->cinfo, COL_PROTOCOL, "TURN CHANNEL"); + + col_add_fstr(pinfo->cinfo, COL_INFO, "Channel Id 0x%x", channel_id); + + ti = proto_tree_add_item(tree, proto_turnchannel, tvb, 0, -1, ENC_NA); + + turnchannel_tree = proto_item_add_subtree(ti, ett_turnchannel); + + proto_tree_add_uint(turnchannel_tree, hf_turnchannel_id, tvb, 0, 2, channel_id); + proto_tree_add_uint(turnchannel_tree, hf_turnchannel_len, tvb, 2, 2, data_len); + + if (len > TURNCHANNEL_HDR_LEN) { + tvbuff_t *next_tvb; + guint reported_len, new_len; + + new_len = tvb_captured_length_remaining(tvb, TURNCHANNEL_HDR_LEN); + reported_len = tvb_reported_length_remaining(tvb, + TURNCHANNEL_HDR_LEN); + if (data_len < reported_len) { + reported_len = data_len; + } + next_tvb = tvb_new_subset_length_caplen(tvb, TURNCHANNEL_HDR_LEN, new_len, + reported_len); + + + if (!dissector_try_heuristic(heur_subdissector_list, + next_tvb, pinfo, tree, &hdtbl_entry, NULL)) { + call_data_dissector(next_tvb, pinfo, tree); + } + } + + return tvb_captured_length(tvb); +} + +static guint +get_turnchannel_message_len(packet_info *pinfo _U_, tvbuff_t *tvb, + int offset, void *data _U_) +{ + guint16 channel_id; + channel_id = tvb_get_ntohs(tvb, 0); + /* If the channel number is outside the range, either we missed + * a TCP segment or this is STUN, DTLS, RTP, etc. multiplexed on + * the same 5-tuple. Report the length as the rest of the packet + * and dissect_turnchannel_message will reject it, rather than + * using a bogus PDU length and messing up the dissection of + * future TURN packets. + */ + if (!test_turnchannel_id(channel_id)) { + return tvb_reported_length(tvb); + } + return (guint)tvb_get_ntohs(tvb, offset+2) + TURNCHANNEL_HDR_LEN; +} + +static int +dissect_turnchannel_tcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data) +{ + tcp_dissect_pdus(tvb, pinfo, tree, TRUE, TURNCHANNEL_HDR_LEN, + get_turnchannel_message_len, dissect_turnchannel_message, data); + return tvb_captured_length(tvb); +} + +void +proto_register_turnchannel(void) +{ + static hf_register_info hf[] = { + { &hf_turnchannel_id, + { "TURN Channel ID", "turnchannel.id", FT_UINT16, + BASE_HEX, NULL, 0x0, NULL, HFILL } + }, + { &hf_turnchannel_len, + { "Data Length", "turnchannel.length", FT_UINT16, + BASE_DEC, NULL, 0x0, NULL, HFILL } + }, + }; + +/* Setup protocol subtree array */ + static gint *ett[] = { + &ett_turnchannel, + }; + +/* Register the protocol name and description */ + proto_turnchannel = proto_register_protocol("TURN Channel", "TURNCHANNEL", "turnchannel"); + + turnchannel_tcp_handle = register_dissector("turnchannel-tcp", dissect_turnchannel_tcp, proto_turnchannel); + turnchannel_udp_handle = register_dissector("turnchannel", dissect_turnchannel_message, proto_turnchannel); + +/* subdissectors */ + /* XXX: Nothing actually registers to this list. All dissectors register + * to the heuristic subdissector list for STUN, since the STUN dissector + * doesn't actually call this dissector but uses its own implementation + * of TURN Channel messages. + */ + heur_subdissector_list = register_heur_dissector_list("turnchannel", proto_turnchannel); + +/* Required function calls to register the header fields and subtrees used */ + proto_register_field_array(proto_turnchannel, hf, array_length(hf)); + proto_register_subtree_array(ett, array_length(ett)); + +} + + +void +proto_reg_handoff_turnchannel(void) +{ + /* Register for "Decode As" in case STUN negotiation isn't captured */ + dissector_add_for_decode_as_with_preference("tcp.port", turnchannel_tcp_handle); + dissector_add_for_decode_as_with_preference("udp.port", turnchannel_udp_handle); + + /* + * SSL/TLS and DTLS Application-Layer Protocol Negotiation (ALPN) + * protocol ID. + */ + dissector_add_string("tls.alpn", "stun.turn", turnchannel_tcp_handle); + dissector_add_string("dtls.alpn", "stun.turn", turnchannel_udp_handle); +} + +/* + * Editor modelines - https://www.wireshark.org/tools/modelines.html + * + * Local variables: + * c-basic-offset: 8 + * tab-width: 8 + * indent-tabs-mode: t + * End: + * + * vi: set shiftwidth=8 tabstop=8 noexpandtab: + * :indentSize=8:tabSize=8:noTabs=false: + */ |