Adding upstream version 4.2.2.upstream/4.2.2

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

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:
+ */