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/* packet-vlan.c
* Routines for VLAN 802.1Q ethernet header disassembly
*
* 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.
*/
#define NEW_PROTO_TREE_API
#include "config.h"
#include <epan/packet.h>
#include <epan/capture_dissectors.h>
#include <wsutil/pint.h>
#include <epan/expert.h>
#include "packet-ieee8023.h"
#include "packet-ipx.h"
#include "packet-llc.h"
#include <epan/etypes.h>
#include <epan/prefs.h>
#include <epan/to_str.h>
#include <epan/addr_resolv.h>
void proto_register_vlan(void);
void proto_reg_handoff_vlan(void);
static unsigned int q_in_q_ethertype = ETHERTYPE_QINQ_OLD;
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_id_name VLAN_HFI_INIT = {
"Name", "vlan.id_name", FT_STRING, STR_UNICODE,
NULL, 0x0, "VLAN ID Name", 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;
proto_item *item;
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);
if (gbl_resolv_flags.vlan_name) {
item = proto_tree_add_string(vlan_tree, &hfi_vlan_id_name, tvb, 0, 2,
get_vlan_name(wmem_packet_scope(), vlan_id));
PROTO_ITEM_SET_GENERATED(item);
}
}
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_id_name,
&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_add_dependency("ethertype", hfi_vlan->id);
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:
*/