Initial version of VNTAG dissector (bug #7496)

svn path=/trunk/; revision=43928

1 files changed, 131 insertions, 0 deletions

diff --git a/epan/dissectors/packet-vntag.c b/epan/dissectors/packet-vntag.c
new file mode 100644
index 0000000000..649089523f
--- /dev/null
+++ b/epan/dissectors/packet-vntag.c
@@ -0,0 +1,131 @@
+/* packet-vntag.c
+ *
+ * $Id$
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <glib.h>
+#include <epan/packet.h>
+#include <epan/etypes.h>
+#include <epan/prefs.h>
+
+static int proto_vntag = -1;
+
+static int hf_vntag_etype = -1;
+static int hf_vntag_len = -1;
+static int hf_vntag_trailer = -1;
+
+static gint ett_vntag = -1;
+
+static void
+dissect_vntag(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
+{
+	guint16 encap_proto;
+	proto_tree *vntag_tree = NULL;
+
+	col_set_str(pinfo->cinfo, COL_PROTOCOL, "VNTAG");
+	col_clear(pinfo->cinfo, COL_INFO);
+
+	if (tree) {
+		proto_item *ti = proto_tree_add_item(tree, proto_vntag, tvb, 0, 4, ENC_NA);
+
+		vntag_tree = proto_item_add_subtree(ti, ett_vntag);
+
+		/* XXX, 4 bytes of data */
+
+		/* from scapy (http://hg.secdev.org/scapy-com/rev/37acec891993) GPLv2:
+
+		   BitField("dir",     0, 1),
+		   BitField("ptr",     0, 1),
+		   BitField("dst",     0, 14),
+		   BitField("looped",  0, 1),
+		   BitField("r",       0, 1),
+		   BitField("version", 0, 2),
+		   BitField("src",     0, 12) ]
+		*/
+		/* another: http://www.definethecloud.net/access-layer-network-virtualization-vn-tag-and-vepa */
+	}
+
+	encap_proto = tvb_get_ntohs(tvb, 4);
+
+	/* copied from packet-vlan.c do we need it also for VNTAG? */
+#if 0
+	if (encap_proto <= IEEE_802_3_MAX_LEN) {
+		gboolean is_802_2;
+
+		/* Is there an 802.2 layer? I can tell by looking at the first 2
+		   bytes after the VLAN header. If they are 0xffff, then what
+		   follows the VLAN header is an IPX payload, meaning no 802.2.
+		   (IPX/SPX is they only thing that can be contained inside a
+		   straight 802.3 packet, so presumably the same applies for
+		   Ethernet VLAN packets). A non-0xffff value means that there's an
+		   802.2 layer inside the VLAN layer */
+		is_802_2 = TRUE;
+
+		/* Don't throw an exception for this check (even a BoundsError) */
+		if (tvb_length_remaining(tvb, 4) >= 2) {
+			if (tvb_get_ntohs(tvb, 4) == 0xffff)
+				is_802_2 = FALSE;
+		}
+
+		dissect_802_3(encap_proto, is_802_2, tvb, 4, pinfo, tree, vntag_tree, hf_vntag_len, hf_vntag_trailer, 0);
+	} else
+#endif
+		ethertype(encap_proto, tvb, 6, pinfo, tree, vntag_tree, hf_vntag_etype, hf_vntag_trailer, 0);
+}
+
+void
+proto_register_vntag(void)
+{
+	static hf_register_info hf[] = {
+		{ &hf_vntag_etype,
+			{ "Type", "vntag.etype", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0, NULL, HFILL }
+		},
+		{ &hf_vntag_len,
+			{ "Length", "vntag.len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }
+		},
+		{ &hf_vntag_trailer,
+			{ "Trailer", "vntag.trailer", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }
+		}
+	};
+
+	static gint *ett[] = {
+		&ett_vntag
+	};
+
+	proto_vntag = proto_register_protocol("VN-Tag", "VNTAG", "vntag");
+	proto_register_field_array(proto_vntag, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+}
+
+void
+proto_reg_handoff_vntag(void)
+{
+	dissector_handle_t vntag_handle;
+
+	/* XXX, add 0x8926 define to epan/etypes.h && etype_vals */
+
+	vntag_handle = create_dissector_handle(dissect_vntag, proto_vntag);
+	dissector_add_uint("ethertype", 0x8926, vntag_handle);
+}