/* packet-vlan.c * Routines for VLAN 802.1Q ethernet header disassembly * * $Id$ * * Wireshark - Network traffic analyzer * By Gerald Combs * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include "packet-ieee8023.h" #include "packet-ipx.h" #include "packet-llc.h" #include "packet-vlan.h" #include #include void proto_reg_handoff_vlan(void); static unsigned int q_in_q_ethertype = 0x9100; static gboolean vlan_summary_in_tree = TRUE; static int proto_vlan = -1; static int hf_vlan_priority = -1; static int hf_vlan_cfi = -1; static int hf_vlan_id = -1; static int hf_vlan_etype = -1; static int hf_vlan_len = -1; static int hf_vlan_trailer = -1; static gint ett_vlan = -1; /* From Table G-2 of IEEE standard 802.1D-2004 */ static const value_string pri_vals[] = { { 1, "Background" }, { 2, "Spare" }, { 0, "Best Effort (default)" }, { 3, "Excellent Effort" }, { 4, "Controlled Load" }, { 5, "Video, < 100ms latency and jitter" }, { 6, "Voice, < 10ms latency and jitter" }, { 7, "Network Control" }, { 0, NULL } }; static const value_string cfi_vals[] = { { 0, "Canonical" }, { 1, "Non-canonical" }, { 0, NULL } }; void capture_vlan(const guchar *pd, int offset, int len, packet_counts *ld ) { guint16 encap_proto; if ( !BYTES_ARE_IN_FRAME(offset,len,5) ) { ld->other++; return; } encap_proto = pntohs( &pd[offset+2] ); if ( encap_proto <= IEEE_802_3_MAX_LEN) { if ( pd[offset+4] == 0xff && pd[offset+5] == 0xff ) { capture_ipx(ld); } else { capture_llc(pd,offset+4,len,ld); } } else { capture_ethertype(encap_proto, pd, offset+4, len, ld); } } static void dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_item *ti; guint16 tci; volatile guint16 encap_proto; volatile gboolean is_802_2; proto_tree *volatile vlan_tree; col_set_str(pinfo->cinfo, COL_PROTOCOL, "VLAN"); col_clear(pinfo->cinfo, COL_INFO); tci = tvb_get_ntohs( tvb, 0 ); col_add_fstr(pinfo->cinfo, COL_INFO, "PRI: %u CFI: %u ID: %u", (tci >> 13), ((tci >> 12) & 1), (tci & 0xFFF)); col_add_fstr(pinfo->cinfo, COL_8021Q_VLAN_ID, "%u", (tci & 0xFFF)); vlan_tree = NULL; if (tree) { ti = proto_tree_add_item(tree, proto_vlan, tvb, 0, 4, ENC_NA); if (vlan_summary_in_tree) { proto_item_append_text(ti, ", PRI: %u, CFI: %u, ID: %u", (tci >> 13), ((tci >> 12) & 1), (tci & 0xFFF)); } vlan_tree = proto_item_add_subtree(ti, ett_vlan); proto_tree_add_item(vlan_tree, hf_vlan_priority, tvb, 0, 2, ENC_BIG_ENDIAN); proto_tree_add_item(vlan_tree, hf_vlan_cfi, tvb, 0, 2, ENC_BIG_ENDIAN); proto_tree_add_item(vlan_tree, hf_vlan_id, tvb, 0, 2, ENC_BIG_ENDIAN); } encap_proto = tvb_get_ntohs(tvb, 2); if (encap_proto <= IEEE_802_3_MAX_LEN) { /* 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, vlan_tree, hf_vlan_len, hf_vlan_trailer, 0); } else { ethertype(encap_proto, tvb, 4, pinfo, tree, vlan_tree, hf_vlan_etype, hf_vlan_trailer, 0); } } void proto_register_vlan(void) { static hf_register_info hf[] = { { &hf_vlan_priority, { "Priority", "vlan.priority", FT_UINT16, BASE_DEC, VALS(pri_vals), 0xE000, "Descriptions are recommendations from IEEE standard 802.1D-2004", HFILL }}, { &hf_vlan_cfi, { "CFI", "vlan.cfi", FT_UINT16, BASE_DEC, VALS(cfi_vals), 0x1000, "Canonical Format Identifier", HFILL }}, { &hf_vlan_id, { "ID", "vlan.id", FT_UINT16, BASE_DEC, NULL, 0x0FFF, "VLAN ID", HFILL }}, { &hf_vlan_etype, { "Type", "vlan.etype", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0, "Ethertype", HFILL }}, { &hf_vlan_len, { "Length", "vlan.len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_vlan_trailer, { "Trailer", "vlan.trailer", FT_BYTES, BASE_NONE, NULL, 0x0, "VLAN Trailer", HFILL }} }; static gint *ett[] = { &ett_vlan }; module_t *vlan_module; proto_vlan = proto_register_protocol("802.1Q Virtual LAN", "VLAN", "vlan"); proto_register_field_array(proto_vlan, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); vlan_module = prefs_register_protocol(proto_vlan, proto_reg_handoff_vlan); prefs_register_bool_preference(vlan_module, "summary_in_tree", "Show vlan summary in protocol tree", "Whether the vlan summary line should be shown in the protocol tree", &vlan_summary_in_tree); prefs_register_uint_preference(vlan_module, "qinq_ethertype", "802.1QinQ Ethertype (in hex)", "The (hexadecimal) Ethertype used to indicate 802.1QinQ VLAN in VLAN tunneling.", 16, &q_in_q_ethertype); } void proto_reg_handoff_vlan(void) { static gboolean prefs_initialized = FALSE; static dissector_handle_t vlan_handle; static unsigned int old_q_in_q_ethertype; if (!prefs_initialized) { vlan_handle = create_dissector_handle(dissect_vlan, proto_vlan); dissector_add_uint("ethertype", ETHERTYPE_VLAN, vlan_handle); prefs_initialized = TRUE; } else { dissector_delete_uint("ethertype", old_q_in_q_ethertype, vlan_handle); } old_q_in_q_ethertype = q_in_q_ethertype; dissector_add_uint("ethertype", q_in_q_ethertype, vlan_handle); }