/* packet-vlan.c * Routines for VLAN 802.1Q ethernet header disassembly * * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #define NEW_PROTO_TREE_API #include "config.h" #include #include #include #include #include "packet-ieee8023.h" #include "packet-ipx.h" #include "packet-llc.h" #include #include #include void proto_register_vlan(void); void proto_reg_handoff_vlan(void); static unsigned int q_in_q_ethertype = 0x9100; static gboolean vlan_summary_in_tree = TRUE; static dissector_handle_t vlan_handle; static dissector_handle_t ethertype_handle; static header_field_info *hfi_vlan = NULL; #define VLAN_HFI_INIT HFI_INIT(proto_vlan) /* 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 header_field_info hfi_vlan_priority VLAN_HFI_INIT = { "Priority", "vlan.priority", FT_UINT16, BASE_DEC, VALS(pri_vals), 0xE000, "Descriptions are recommendations from IEEE standard 802.1D-2004", HFILL }; static const value_string cfi_vals[] = { { 0, "Canonical" }, { 1, "Non-canonical" }, { 0, NULL } }; static header_field_info hfi_vlan_cfi VLAN_HFI_INIT = { "CFI", "vlan.cfi", FT_UINT16, BASE_DEC, VALS(cfi_vals), 0x1000, "Canonical Format Identifier", HFILL }; static header_field_info hfi_vlan_id VLAN_HFI_INIT = { "ID", "vlan.id", FT_UINT16, BASE_DEC, NULL, 0x0FFF, "VLAN ID", HFILL }; static header_field_info hfi_vlan_etype VLAN_HFI_INIT = { "Type", "vlan.etype", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0, "Ethertype", HFILL }; static header_field_info hfi_vlan_len VLAN_HFI_INIT = { "Length", "vlan.len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }; static header_field_info hfi_vlan_trailer VLAN_HFI_INIT = { "Trailer", "vlan.trailer", FT_BYTES, BASE_NONE, NULL, 0x0, "VLAN Trailer", HFILL }; static gint ett_vlan = -1; static expert_field ei_vlan_len = EI_INIT; static gboolean capture_vlan(const guchar *pd, int offset, int len, capture_packet_info_t *cpinfo, const union wtap_pseudo_header *pseudo_header _U_ ) { guint16 encap_proto; if ( !BYTES_ARE_IN_FRAME(offset,len,5) ) return FALSE; encap_proto = pntoh16( &pd[offset+2] ); if ( encap_proto <= IEEE_802_3_MAX_LEN) { if ( pd[offset+4] == 0xff && pd[offset+5] == 0xff ) { return capture_ipx(pd,offset+4,len, cpinfo, pseudo_header); } else { return capture_llc(pd,offset+4,len, cpinfo, pseudo_header); } } return try_capture_dissector("ethertype", encap_proto, pd, offset+4, len, cpinfo, pseudo_header); } static void columns_set_vlan(column_info *cinfo, guint16 tci) { static const char fast_str[][2] = { "0", "1", "2", "3", "4", "5", "6", "7" }; char id_str[16]; guint32_to_str_buf(tci & 0xFFF, id_str, sizeof(id_str)); col_add_lstr(cinfo, COL_INFO, "PRI: ", fast_str[(tci >> 13) & 7], " " "CFI: ", fast_str[(tci >> 12) & 1], " " "ID: ", id_str, COL_ADD_LSTR_TERMINATOR); col_add_str(cinfo, COL_8021Q_VLAN_ID, id_str); } static int dissect_vlan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { proto_item *ti; guint16 tci, vlan_id; guint16 encap_proto; gboolean is_802_2; proto_tree *vlan_tree; col_set_str(pinfo->cinfo, COL_PROTOCOL, "VLAN"); col_clear(pinfo->cinfo, COL_INFO); tci = tvb_get_ntohs( tvb, 0 ); vlan_id = tci & 0xFFF; /* Add the VLAN Id if it's the first one*/ if (pinfo->vlan_id == 0) { pinfo->vlan_id = vlan_id; } columns_set_vlan(pinfo->cinfo, tci); vlan_tree = NULL; if (tree) { ti = proto_tree_add_item(tree, hfi_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), vlan_id); } vlan_tree = proto_item_add_subtree(ti, ett_vlan); proto_tree_add_item(vlan_tree, &hfi_vlan_priority, tvb, 0, 2, ENC_BIG_ENDIAN); proto_tree_add_item(vlan_tree, &hfi_vlan_cfi, tvb, 0, 2, ENC_BIG_ENDIAN); proto_tree_add_item(vlan_tree, &hfi_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_captured_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, hfi_vlan_len.id, hfi_vlan_trailer.id, &ei_vlan_len, 0); } else { ethertype_data_t ethertype_data; ethertype_data.etype = encap_proto; ethertype_data.offset_after_ethertype = 4; ethertype_data.fh_tree = vlan_tree; ethertype_data.etype_id = hfi_vlan_etype.id; ethertype_data.trailer_id = hfi_vlan_trailer.id; ethertype_data.fcs_len = 0; call_dissector_with_data(ethertype_handle, tvb, pinfo, tree, ðertype_data); } return tvb_captured_length(tvb); } void proto_register_vlan(void) { #ifndef HAVE_HFI_SECTION_INIT static header_field_info *hfi[] = { &hfi_vlan_priority, &hfi_vlan_cfi, &hfi_vlan_id, &hfi_vlan_etype, &hfi_vlan_len, &hfi_vlan_trailer, }; #endif /* HAVE_HFI_SECTION_INIT */ static gint *ett[] = { &ett_vlan }; static ei_register_info ei[] = { { &ei_vlan_len, { "vlan.len.past_end", PI_MALFORMED, PI_ERROR, "Length field value goes past the end of the payload", EXPFILL }}, }; module_t *vlan_module; expert_module_t* expert_vlan; int proto_vlan; proto_vlan = proto_register_protocol("802.1Q Virtual LAN", "VLAN", "vlan"); hfi_vlan = proto_registrar_get_nth(proto_vlan); proto_register_fields(proto_vlan, hfi, array_length(hfi)); proto_register_subtree_array(ett, array_length(ett)); expert_vlan = expert_register_protocol(proto_vlan); expert_register_field_array(expert_vlan, ei, array_length(ei)); 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); vlan_handle = create_dissector_handle(dissect_vlan, proto_vlan); } void proto_reg_handoff_vlan(void) { static gboolean prefs_initialized = FALSE; static unsigned int old_q_in_q_ethertype; if (!prefs_initialized) { dissector_add_uint("ethertype", ETHERTYPE_VLAN, vlan_handle); register_capture_dissector("ethertype", ETHERTYPE_VLAN, capture_vlan, hfi_vlan->id); prefs_initialized = TRUE; } else { dissector_delete_uint("ethertype", old_q_in_q_ethertype, vlan_handle); } old_q_in_q_ethertype = q_in_q_ethertype; ethertype_handle = find_dissector("ethertype"); dissector_add_uint("ethertype", q_in_q_ethertype, vlan_handle); } /* * Editor modelines - http://www.wireshark.org/tools/modelines.html * * Local Variables: * c-basic-offset: 2 * tab-width: 8 * indent-tabs-mode: nil * End: * * ex: set shiftwidth=2 tabstop=8 expandtab: * :indentSize=2:tabSize=8:noTabs=true: */