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wireshark/epan/dissectors/packet-bfd.c

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/* packet-bfd.c
* Routines for Bidirectional Forwarding Detection (BFD) message dissection
* RFCs
* 5880: Bidirectional Forwarding Detection (BFD)
* 5881: Bidirectional Forwarding Detection (BFD) for IPv4 and IPv6 (Single Hop)
* 5882: Generic Application of Bidirectional Forwarding Detection (BFD)
* 5883: Bidirectional Forwarding Detection (BFD) for Multihop Paths
* 5884: Bidirectional Forwarding Detection (BFD) for MPLS Label Switched Paths (LSPs)
* 5885: Bidirectional Forwarding Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification (VCCV)
* (and https://tools.ietf.org/html/draft-ietf-bfd-base-01 for version 0)
*
* Copyright 2003, Hannes Gredler <hannes@juniper.net>
* Copyright 2006, Balint Reczey <Balint.Reczey@ericsson.com>
* Copyright 2007, Todd J Martin <todd.martin@acm.org>
*
* Copyright 2011, Jaihari Kalijanakiraman <jaiharik@ipinfusion.com>
* Krishnamurthy Mayya <krishnamurthy.mayya@ipinfusion.com>
* Nikitha Malgi <malgi.nikitha@ipinfusion.com>
* - support for MPLS-TP BFD Proactive CV Message Format as per RFC 6428
* - includes decoding support for Section MEP-ID, LSP MEP-ID, PW MEP-ID
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/expert.h>
#include "packet-bfd.h"
#include "packet-mpls.h"
void proto_register_bfd(void);
void proto_reg_handoff_bfd(void);
/* 3784: BFD control, 3785: BFD echo, 4784: BFD multi hop control */
#define UDP_PORT_RANGE_BFD_CTRL "3784,4784"
#define UDP_PORT_BFD_ECHO 3785
/* As per RFC 6428 : https://tools.ietf.org/html/rfc6428
Section: 3.5 */
#define TLV_TYPE_MPLSTP_SECTION_MEP 0
#define TLV_TYPE_MPLSTP_LSP_MEP 1
#define TLV_TYPE_MPLSTP_PW_MEP 2
static const value_string mplstp_mep_tlv_type_values [] = {
{ TLV_TYPE_MPLSTP_SECTION_MEP, "Section MEP-ID" },
{ TLV_TYPE_MPLSTP_LSP_MEP, "LSP MEP-ID" },
{ TLV_TYPE_MPLSTP_PW_MEP, "PW MEP-ID" },
{ 0, NULL}
};
static const value_string bfd_control_v0_diag_values[] = {
{ 0, "No Diagnostic" },
{ 1, "Control Detection Time Expired" },
{ 2, "Echo Function Failed" },
{ 3, "Neighbor Signaled Session Down" },
{ 4, "Forwarding Plane Reset" },
{ 5, "Path Down" },
{ 6, "Concatenated Path Down" },
{ 7, "Administratively Down" },
{ 0, NULL }
};
static const value_string bfd_control_v1_diag_values[] = {
{ 0, "No Diagnostic" },
{ 1, "Control Detection Time Expired" },
{ 2, "Echo Function Failed" },
{ 3, "Neighbor Signaled Session Down" },
{ 4, "Forwarding Plane Reset" },
{ 5, "Path Down" },
{ 6, "Concatenated Path Down" },
{ 7, "Administratively Down" },
{ 8, "Reverse Concatenated Path Down" },
{ 9, "Mis-Connectivity Defect" },
{ 0, NULL }
};
static const value_string bfd_control_sta_values[] = {
{ 0, "AdminDown" },
{ 1, "Down" },
{ 2, "Init" },
{ 3, "Up" },
{ 0, NULL }
};
#define BFD_AUTH_SIMPLE 1
#define BFD_AUTH_MD5 2
#define BFD_AUTH_MET_MD5 3
#define BFD_AUTH_SHA1 4
#define BFD_AUTH_MET_SHA1 5
static const value_string bfd_control_auth_type_values[] = {
{ BFD_AUTH_SIMPLE , "Simple Password" },
{ BFD_AUTH_MD5 , "Keyed MD5" },
{ BFD_AUTH_MET_MD5 , "Meticulous Keyed MD5" },
{ BFD_AUTH_SHA1 , "Keyed SHA1" },
{ BFD_AUTH_MET_SHA1 , "Meticulous Keyed SHA1" },
{ 0, NULL }
};
/* Per the standard, the simple password must by 1-16 bytes in length */
#define MAX_PASSWORD_LEN 16
/* Per the standard, the length of the MD5 authentication packets must be 24
* bytes and the checksum is 16 bytes */
#define MD5_AUTH_LEN 24
#define MD5_CHECKSUM_LEN 16
/* Per the standard, the length of the SHA1 authentication packets must be 28
* bytes and the checksum is 20 bytes */
#define SHA1_AUTH_LEN 28
#define SHA1_CHECKSUM_LEN 20
static gint proto_bfd = -1;
static gint proto_bfd_echo = -1;
static gint hf_bfd_version = -1;
static gint hf_bfd_diag = -1;
static gint hf_bfd_sta = -1;
static gint hf_bfd_flags = -1;
static gint hf_bfd_flags_h = -1;
static gint hf_bfd_flags_p = -1;
static gint hf_bfd_flags_f = -1;
static gint hf_bfd_flags_c = -1;
static gint hf_bfd_flags_a = -1;
static gint hf_bfd_flags_d = -1;
static gint hf_bfd_flags_m = -1;
static gint hf_bfd_flags_d_v0 = -1;
static gint hf_bfd_flags_p_v0 = -1;
static gint hf_bfd_flags_f_v0 = -1;
static gint hf_bfd_detect_time_multiplier = -1;
static gint hf_bfd_message_length = -1;
static gint hf_bfd_my_discriminator = -1;
static gint hf_bfd_your_discriminator = -1;
static gint hf_bfd_desired_min_tx_interval = -1;
static gint hf_bfd_required_min_rx_interval = -1;
static gint hf_bfd_required_min_echo_interval = -1;
static gint hf_bfd_checksum = -1;
static gint hf_bfd_auth_type = -1;
static gint hf_bfd_auth_len = -1;
static gint hf_bfd_auth_key = -1;
static gint hf_bfd_auth_password = -1;
static gint hf_bfd_auth_seq_num = -1;
static gint hf_bfd_echo = -1;
static gint ett_bfd = -1;
static gint ett_bfd_flags = -1;
static gint ett_bfd_auth = -1;
static gint ett_bfd_echo = -1;
static expert_field ei_bfd_auth_len_invalid = EI_INIT;
static expert_field ei_bfd_auth_no_data = EI_INIT;
static gint hf_mep_type = -1;
static gint hf_mep_len = -1;
static gint hf_mep_global_id = -1;
static gint hf_mep_node_id = -1;
/* static gint hf_mep_interface_no = -1; */
static gint hf_mep_tunnel_no = -1;
static gint hf_mep_lsp_no = -1;
static gint hf_mep_ac_id = -1;
static gint hf_mep_agi_type = -1;
static gint hf_mep_agi_len = -1;
static gint hf_mep_agi_val = -1;
static gint hf_section_interface_no = -1;
/*
* Control packet version 0, draft-katz-ward-bfd-01.txt
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |Vers | Diag |H|D|P|F| Rsvd | Detect Mult | Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | My Discriminator |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Your Discriminator |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Desired Min TX Interval |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Required Min RX Interval |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Required Min Echo RX Interval |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
/*
* Control packet version 1, RFC 5880
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |Vers | Diag |Sta|P|F|C|A|D|M| Detect Mult | Length |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | My Discriminator |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Your Discriminator |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Desired Min TX Interval |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Required Min RX Interval |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Required Min Echo RX Interval |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* An optional Authentication Section may be present:
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Auth Type | Auth Len | Authentication Data... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* There are 5 types of authentication defined:
* 1 - Simple Password
* 2 - Keyed MD5
* 3 - Meticulous Keyed MD5
* 4 - Keyed SHA1
* 5 - Meticulous Keyed SHA1
*
* The format for Simple Password authentication is:
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Auth Type | Auth Len | Auth Key ID | Password... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* The format for Keyed MD5 and Meticulous Keyed MD5 authentication is:
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Auth Type | Auth Len | Auth Key ID | Reserved |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Sequence Number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Auth Key/Checksum... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* The format for Keyed SHA1 and Meticulous Keyed SHA1 authentication is:
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Auth Type | Auth Len | Auth Key ID | Reserved |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Sequence Number |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Auth Key/Checksum... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
*
*/
/* Given the type of authentication being used, return the required length of
* the authentication header
*/
static guint8
get_bfd_required_auth_len(guint8 auth_type)
{
guint8 auth_len = 0;
switch (auth_type) {
case BFD_AUTH_MD5:
case BFD_AUTH_MET_MD5:
auth_len = MD5_AUTH_LEN;
break;
case BFD_AUTH_SHA1:
case BFD_AUTH_MET_SHA1:
auth_len = SHA1_AUTH_LEN;
break;
default:
break;
}
return auth_len;
}
/* Given the type of authentication being used, return the length of
* checksum field
*/
static guint8
get_bfd_checksum_len(guint8 auth_type)
{
guint8 checksum_len = 0;
switch (auth_type) {
case BFD_AUTH_MD5:
case BFD_AUTH_MET_MD5:
checksum_len = MD5_CHECKSUM_LEN;
break;
case BFD_AUTH_SHA1:
case BFD_AUTH_MET_SHA1:
checksum_len = SHA1_CHECKSUM_LEN;
break;
default:
break;
}
return checksum_len;
}
static void
dissect_bfd_authentication(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
int offset = 24;
guint8 auth_type;
guint8 auth_len;
proto_item *auth_item = NULL;
proto_tree *auth_tree = NULL;
const guint8 *password;
auth_type = tvb_get_guint8(tvb, offset);
auth_len = tvb_get_guint8(tvb, offset + 1);
if (tree) {
auth_tree = proto_tree_add_subtree_format(tree, tvb, offset, auth_len,
ett_bfd_auth, NULL, "Authentication: %s",
val_to_str(auth_type,
bfd_control_auth_type_values,
"Unknown Authentication Type (%d)") );
proto_tree_add_item(auth_tree, hf_bfd_auth_type, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(auth_tree, hf_bfd_auth_len, tvb, offset + 1, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(auth_tree, hf_bfd_auth_key, tvb, offset + 2, 1, ENC_BIG_ENDIAN);
}
switch (auth_type) {
case BFD_AUTH_SIMPLE:
proto_tree_add_item_ret_string(auth_tree, hf_bfd_auth_password, tvb, offset+3,
auth_len-3, ENC_ASCII|ENC_NA, wmem_packet_scope(), &password);
proto_item_append_text(auth_item, ": %s", password);
break;
case BFD_AUTH_MD5:
case BFD_AUTH_MET_MD5:
case BFD_AUTH_SHA1:
case BFD_AUTH_MET_SHA1:
if (auth_len != get_bfd_required_auth_len(auth_type)) {
proto_tree_add_expert_format(auth_tree, pinfo, &ei_bfd_auth_len_invalid, tvb, offset, auth_len,
"Length of authentication section (%d) is invalid for Authentication Type: %s",
auth_len, val_to_str(auth_type, bfd_control_auth_type_values, "Unknown Authentication Type (%d)") );
proto_item_append_text(auth_item, ": Invalid Authentication Section");
}
if (tree) {
proto_tree_add_item(auth_tree, hf_bfd_auth_seq_num, tvb, offset+4, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(auth_tree, hf_bfd_checksum, tvb, offset+8, get_bfd_checksum_len(auth_type), ENC_NA);
}
break;
default:
break;
}
}
static int
dissect_bfd_echo(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_tree *bfd_tree = NULL;
guint bfd_length = tvb_reported_length_remaining(tvb, 0);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BFD Echo");
/* XXX Add direction */
col_set_str(pinfo->cinfo, COL_INFO, "Originator specific content");
if (tree) {
proto_item *ti;
ti = proto_tree_add_protocol_format(tree, proto_bfd_echo, tvb, 0, bfd_length,
"BFD Echo message");
bfd_tree = proto_item_add_subtree(ti, ett_bfd_echo);
proto_tree_add_item(bfd_tree, hf_bfd_echo, tvb, 0, bfd_length, ENC_NA);
}
return bfd_length;
}
static int
dissect_bfd_control(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
guint flags;
guint bfd_version;
guint bfd_diag;
guint bfd_sta = 0;
guint bfd_flags;
guint bfd_flags_a = 0;
guint bfd_detect_time_multiplier;
guint bfd_length;
guint bfd_my_discriminator;
guint bfd_your_discriminator;
guint bfd_desired_min_tx_interval;
guint bfd_required_min_rx_interval;
guint bfd_required_min_echo_interval;
proto_tree *bfd_tree = NULL;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BFD Control");
col_clear(pinfo->cinfo, COL_INFO);
bfd_version = (tvb_get_guint8(tvb, 0) & 0xe0) >> 5;
bfd_diag = (tvb_get_guint8(tvb, 0) & 0x1f);
flags = tvb_get_guint8(tvb, 1);
switch (bfd_version) {
case 0:
bfd_flags = flags;
break;
case 1:
default:
bfd_sta = flags & 0xc0;
bfd_flags = flags & 0x3e;
bfd_flags_a = flags & 0x04;
break;
}
bfd_detect_time_multiplier = tvb_get_guint8(tvb, 2);
bfd_length = tvb_get_guint8(tvb, 3);
bfd_my_discriminator = tvb_get_ntohl(tvb, 4);
bfd_your_discriminator = tvb_get_ntohl(tvb, 8);
bfd_desired_min_tx_interval = tvb_get_ntohl(tvb, 12);
bfd_required_min_rx_interval = tvb_get_ntohl(tvb, 16);
bfd_required_min_echo_interval = tvb_get_ntohl(tvb, 20);
switch (bfd_version) {
case 0:
col_add_fstr(pinfo->cinfo, COL_INFO, "Diag: %s, Flags: 0x%02x",
val_to_str_const(bfd_diag, bfd_control_v0_diag_values, "Unknown"),
bfd_flags);
break;
case 1:
default:
col_add_fstr(pinfo->cinfo, COL_INFO, "Diag: %s, State: %s, Flags: 0x%02x",
val_to_str_const(bfd_diag, bfd_control_v1_diag_values, "Unknown"),
val_to_str_const(bfd_sta >> 6 , bfd_control_sta_values, "Unknown"),
bfd_flags);
break;
}
if (tree) {
proto_item *ti;
ti = proto_tree_add_protocol_format(tree, proto_bfd, tvb, 0, bfd_length,
"BFD Control message");
bfd_tree = proto_item_add_subtree(ti, ett_bfd);
proto_tree_add_uint(bfd_tree, hf_bfd_version, tvb, 0,
1, bfd_version << 5);
proto_tree_add_uint(bfd_tree, hf_bfd_diag, tvb, 0,
1, bfd_diag);
switch (bfd_version) {
case 0:
break;
case 1:
default:
proto_tree_add_uint(bfd_tree, hf_bfd_sta, tvb, 1,
1, bfd_sta);
break;
}
switch (bfd_version) {
case 0:
{
static int * const bfd_message_flags[] = {
&hf_bfd_flags_h,
&hf_bfd_flags_d_v0,
&hf_bfd_flags_p_v0,
&hf_bfd_flags_f_v0,
NULL
};
proto_tree_add_bitmask_with_flags(bfd_tree, tvb, 1, hf_bfd_flags, ett_bfd_flags, bfd_message_flags, ENC_NA, BMT_NO_FALSE);
}
break;
case 1:
default:
{
static int * const bfd_message_flags[] = {
&hf_bfd_flags_p,
&hf_bfd_flags_f,
&hf_bfd_flags_c,
&hf_bfd_flags_a,
&hf_bfd_flags_d,
&hf_bfd_flags_m,
NULL
};
proto_tree_add_bitmask_with_flags(bfd_tree, tvb, 1, hf_bfd_flags, ett_bfd_flags, bfd_message_flags, ENC_NA, BMT_NO_FALSE);
}
break;
}
proto_tree_add_uint_format_value(bfd_tree, hf_bfd_detect_time_multiplier, tvb, 2,
1, bfd_detect_time_multiplier,
"%u (= %u ms Detection time)",
bfd_detect_time_multiplier,
bfd_detect_time_multiplier * (bfd_desired_min_tx_interval/1000));
proto_tree_add_uint(bfd_tree, hf_bfd_message_length, tvb, 3, 1, bfd_length);
proto_tree_add_uint(bfd_tree, hf_bfd_my_discriminator, tvb, 4,
4, bfd_my_discriminator);
proto_tree_add_uint(bfd_tree, hf_bfd_your_discriminator, tvb, 8,
4, bfd_your_discriminator);
proto_tree_add_uint_format_value(bfd_tree, hf_bfd_desired_min_tx_interval, tvb, 12,
4, bfd_desired_min_tx_interval,
"%4u ms (%u us)",
bfd_desired_min_tx_interval/1000,
bfd_desired_min_tx_interval);
proto_tree_add_uint_format_value(bfd_tree, hf_bfd_required_min_rx_interval, tvb, 16,
4, bfd_required_min_rx_interval,
"%4u ms (%u us)",
bfd_required_min_rx_interval/1000,
bfd_required_min_rx_interval);
proto_tree_add_uint_format_value(bfd_tree, hf_bfd_required_min_echo_interval, tvb, 20,
4, bfd_required_min_echo_interval,
"%4u ms (%u us)",
bfd_required_min_echo_interval/1000,
bfd_required_min_echo_interval);
} /* if (tree) */
/* Dissect the authentication fields if the Authentication flag has
* been set
*/
if (bfd_version && bfd_flags_a) {
if (bfd_length >= 28) {
dissect_bfd_authentication(tvb, pinfo, bfd_tree);
} else {
proto_tree_add_expert_format(bfd_tree, pinfo, &ei_bfd_auth_no_data, tvb, 24, bfd_length-24,
"Authentication: Length of the BFD frame is invalid (%d)", bfd_length);
}
}
return tvb_captured_length(tvb);
}
/* BFD CV Source MEP-ID TLV Decoder,
As per RFC 6428 : https://tools.ietf.org/html/rfc6428
sections - 3.5.1, 3.5.2, 3.5.3 */
void
dissect_bfd_mep (tvbuff_t *tvb, proto_tree *tree, const int hfindex)
{
proto_item *ti;
proto_tree *bfd_tree;
gint offset = 0;
gint mep_type;
gint mep_len;
gint mep_agi_len;
if (!tree)
return;
/* Fetch the BFD control message length and move the offset
to point to the data portion after the control message */
/* The parameter hfindex is used for determining the tree under which MEP-ID TLV
has to be determined. Since according to RFC 6428, MEP-ID TLV can be used by any
OAM function, if hfindex is 0, as per this function the MEP-TLV is a part of
BFD-CV payload. If a non-zero hfindex comes, then tht TLV info will be displayed
under a particular protocol-tree. */
if (!hfindex)
{
offset = tvb_get_guint8(tvb, 3);
mep_type = tvb_get_ntohs (tvb, offset);
mep_len = tvb_get_ntohs (tvb, (offset + 2));
ti = proto_tree_add_protocol_format (tree, proto_bfd, tvb, offset, (mep_len + 4),
"MPLS-TP SOURCE MEP-ID TLV");
}
else
{
mep_type = tvb_get_ntohs (tvb, offset);
mep_len = tvb_get_ntohs (tvb, (offset + 2));
ti = proto_tree_add_protocol_format (tree, hfindex, tvb, offset, (mep_len + 4),
"MPLS-TP SOURCE MEP-ID TLV");
}
switch (mep_type) {
case TLV_TYPE_MPLSTP_SECTION_MEP:
bfd_tree = proto_item_add_subtree (ti, ett_bfd);
proto_tree_add_uint (bfd_tree, hf_mep_type , tvb, offset,
2, mep_type);
proto_tree_add_uint (bfd_tree, hf_mep_len, tvb, (offset + 2),
2, mep_len);
proto_tree_add_item (bfd_tree, hf_mep_global_id, tvb, (offset + 4),
4, ENC_BIG_ENDIAN);
proto_tree_add_item (bfd_tree, hf_mep_node_id, tvb, (offset + 8),
4, ENC_BIG_ENDIAN);
proto_tree_add_item (bfd_tree, hf_section_interface_no, tvb, (offset + 12),
4, ENC_BIG_ENDIAN);
break;
case TLV_TYPE_MPLSTP_LSP_MEP:
bfd_tree = proto_item_add_subtree (ti, ett_bfd);
proto_tree_add_uint (bfd_tree, hf_mep_type , tvb, offset,
2, mep_type);
proto_tree_add_uint (bfd_tree, hf_mep_len, tvb, (offset + 2),
2, mep_len);
proto_tree_add_item (bfd_tree, hf_mep_global_id, tvb, (offset + 4),
4, ENC_BIG_ENDIAN);
proto_tree_add_item (bfd_tree, hf_mep_node_id, tvb, (offset + 8),
4, ENC_BIG_ENDIAN);
proto_tree_add_item (bfd_tree, hf_mep_tunnel_no, tvb, (offset + 12),
2, ENC_BIG_ENDIAN);
proto_tree_add_item (bfd_tree, hf_mep_lsp_no, tvb, (offset + 14),
2, ENC_BIG_ENDIAN);
break;
case TLV_TYPE_MPLSTP_PW_MEP:
mep_agi_len = tvb_get_guint8 (tvb, (offset + 17));
bfd_tree = proto_item_add_subtree (ti, ett_bfd);
proto_tree_add_uint (bfd_tree, hf_mep_type, tvb, offset,
2, (mep_type));
proto_tree_add_uint (bfd_tree, hf_mep_len, tvb, (offset + 2),
2, mep_len);
proto_tree_add_item (bfd_tree, hf_mep_global_id, tvb, (offset + 4),
4, ENC_BIG_ENDIAN);
proto_tree_add_item (bfd_tree, hf_mep_node_id, tvb, (offset + 8),
4, ENC_BIG_ENDIAN);
proto_tree_add_item (bfd_tree, hf_mep_ac_id, tvb, (offset + 12),
4, ENC_BIG_ENDIAN);
proto_tree_add_item (bfd_tree, hf_mep_agi_type, tvb, (offset + 16),
1, ENC_BIG_ENDIAN);
proto_tree_add_uint (bfd_tree, hf_mep_agi_len, tvb, (offset + 17),
1, mep_agi_len);
proto_tree_add_item (bfd_tree, hf_mep_agi_val, tvb, (offset + 18),
mep_agi_len, ENC_ASCII|ENC_NA);
break;
default:
break;
}
return;
}
/* Register the protocol with Wireshark */
void
proto_register_bfd(void)
{
/* Setup list of header fields */
static hf_register_info hf[] = {
{ &hf_bfd_version,
{ "Protocol Version", "bfd.version",
FT_UINT8, BASE_DEC, NULL , 0xe0,
"The version number of the BFD protocol", HFILL }
},
{ &hf_bfd_diag,
{ "Diagnostic Code", "bfd.diag",
FT_UINT8, BASE_HEX, VALS(bfd_control_v1_diag_values), 0x1f,
"This field give the reason for a BFD session failure", HFILL }
},
{ &hf_bfd_sta,
{ "Session State", "bfd.sta",
FT_UINT8, BASE_HEX, VALS(bfd_control_sta_values), 0xc0,
"The BFD state as seen by the transmitting system", HFILL }
},
{ &hf_bfd_flags,
{ "Message Flags", "bfd.flags",
FT_UINT8, BASE_HEX, NULL, 0x00,
NULL, HFILL }
},
{ &hf_bfd_flags_h,
{ "I hear you", "bfd.flags.h",
FT_BOOLEAN, 8, TFS(&tfs_set_notset), 0x80,
NULL, HFILL }
},
{ &hf_bfd_flags_d_v0,
{ "Demand", "bfd.flags.d",
FT_BOOLEAN, 8, TFS(&tfs_set_notset), 0x40,
NULL, HFILL }
},
{ &hf_bfd_flags_p_v0,
{ "Poll", "bfd.flags.p",
FT_BOOLEAN, 8, TFS(&tfs_set_notset), 0x20,
NULL, HFILL }
},
{ &hf_bfd_flags_f_v0,
{ "Final", "bfd.flags.f",
FT_BOOLEAN, 8, TFS(&tfs_set_notset), 0x10,
NULL, HFILL }
},
{ &hf_bfd_flags_p,
{ "Poll", "bfd.flags.p",
FT_BOOLEAN, 6, TFS(&tfs_set_notset), 0x20, /* 6 flag bits; Sta is shown separately */
"If set, the transmitting system is expecting a packet with the Final (F) bit in reply",
HFILL }
},
{ &hf_bfd_flags_f,
{ "Final", "bfd.flags.f",
FT_BOOLEAN, 6, TFS(&tfs_set_notset), 0x10, /* 6 flag bits; Sta is shown separately */
"If set, the transmitting system is replying to a packet with the Poll (P) bit set",
HFILL }
},
{ &hf_bfd_flags_c,
{ "Control Plane Independent", "bfd.flags.c",
FT_BOOLEAN, 6, TFS(&tfs_set_notset), 0x08, /* 6 flag bits; Sta is shown separately */
"If set, the BFD implementation is implemented in the forwarding plane", HFILL }
},
{ &hf_bfd_flags_a,
{ "Authentication Present", "bfd.flags.a",
FT_BOOLEAN, 6, TFS(&tfs_set_notset), 0x04, /* 6 flag bits; Sta is shown separately */
"The Authentication Section is present", HFILL }
},
{ &hf_bfd_flags_d,
{ "Demand", "bfd.flags.d",
FT_BOOLEAN, 6, TFS(&tfs_set_notset), 0x02, /* 6 flag bits; Sta is shown separately */
"If set, Demand mode is active in the transmitting system", HFILL }
},
{ &hf_bfd_flags_m,
{ "Multipoint", "bfd.flags.m",
FT_BOOLEAN, 6, TFS(&tfs_set_notset), 0x01, /* 6 flag bits; Sta is shown separately */
"Reserved for future point-to-multipoint extensions", HFILL }
},
{ &hf_bfd_detect_time_multiplier,
{ "Detect Time Multiplier", "bfd.detect_time_multiplier",
FT_UINT8, BASE_DEC, NULL, 0x0,
"The transmit interval multiplied by this value is the failure detection time", HFILL }
},
{ &hf_bfd_message_length,
{ "Message Length", "bfd.message_length",
FT_UINT8, BASE_DEC|BASE_UNIT_STRING, &units_byte_bytes, 0x0,
"Length of the BFD Control packet, in bytes", HFILL }
},
{ &hf_bfd_my_discriminator,
{ "My Discriminator", "bfd.my_discriminator",
FT_UINT32, BASE_HEX, NULL, 0x0,
NULL, HFILL }
},
{ &hf_bfd_your_discriminator,
{ "Your Discriminator", "bfd.your_discriminator",
FT_UINT32, BASE_HEX, NULL, 0x0,
NULL, HFILL }
},
{ &hf_bfd_desired_min_tx_interval,
{ "Desired Min TX Interval", "bfd.desired_min_tx_interval",
FT_UINT32, BASE_DEC, NULL, 0x0,
"The minimum interval to use when transmitting BFD Control packets", HFILL }
},
{ &hf_bfd_required_min_rx_interval,
{ "Required Min RX Interval", "bfd.required_min_rx_interval",
FT_UINT32, BASE_DEC, NULL, 0x0,
"The minimum interval between received BFD Control packets that this system can support", HFILL }
},
{ &hf_bfd_required_min_echo_interval,
{ "Required Min Echo Interval", "bfd.required_min_echo_interval",
FT_UINT32, BASE_DEC, NULL, 0x0,
"The minimum interval between received BFD Echo packets that this system can support", HFILL }
},
{ &hf_bfd_checksum,
{ "Checksum", "bfd.checksum",
FT_BYTES, BASE_NONE, NULL, 0x0,
NULL, HFILL }
},
{ &hf_bfd_auth_type,
{ "Authentication Type", "bfd.auth.type",
FT_UINT8, BASE_DEC, VALS(bfd_control_auth_type_values), 0x0,
"The type of authentication in use on this session", HFILL }
},
{ &hf_bfd_auth_len,
{ "Authentication Length", "bfd.auth.len",
FT_UINT8, BASE_DEC|BASE_UNIT_STRING, &units_byte_bytes, 0x0,
"The length, in bytes, of the authentication section", HFILL }
},
{ &hf_bfd_auth_key,
{ "Authentication Key ID", "bfd.auth.key",
FT_UINT8, BASE_DEC, NULL, 0x0,
"The Authentication Key ID, identifies which password is in use for this packet", HFILL }
},
{ &hf_bfd_auth_password,
{ "Password", "bfd.auth.password",
FT_STRING, BASE_NONE, NULL, 0x0,
"The simple password in use on this session", HFILL }
},
{ &hf_bfd_auth_seq_num,
{ "Sequence Number", "bfd.auth.seq_num",
FT_UINT32, BASE_HEX, NULL, 0x0,
"The Sequence Number is periodically incremented to prevent replay attacks", HFILL }
},
{ &hf_mep_type,
{ "Type", "bfd.mep.type",
FT_UINT16, BASE_DEC, VALS(mplstp_mep_tlv_type_values), 0x0,
"The type of the MEP Id", HFILL }
},
{ &hf_mep_len,
{ "Length", "bfd.mep.len",
FT_UINT16, BASE_DEC, NULL , 0x0,
"The length of the MEP Id", HFILL }
},
{ &hf_mep_global_id,
{ "Global Id", "bfd.mep.global.id",
FT_UINT32, BASE_DEC, NULL , 0x0,
"MPLS-TP Global MEP Id", HFILL }
},
{ &hf_mep_node_id,
{ "Node Id", "bfd.mep.node.id",
FT_IPv4, BASE_NONE, NULL , 0x0,
"MPLS-TP Node Identifier", HFILL }
},
#if 0
{ &hf_mep_interface_no,
{ "Interface Number", "bfd.mep.interface.no",
FT_UINT32, BASE_DEC, NULL , 0x0,
"MPLS-TP Interface Number", HFILL }
},
#endif
{ &hf_mep_tunnel_no,
{ "Tunnel Number", "bfd.mep.tunnel.no",
FT_UINT16, BASE_DEC, NULL , 0x0,
NULL, HFILL }
},
{ &hf_mep_lsp_no,
{ "LSP Number", "bfd.mep.lsp.no",
FT_UINT16, BASE_DEC, NULL , 0x0,
NULL, HFILL }
},
{ &hf_mep_ac_id,
{ "AC Id", "bfd.mep.ac.id",
FT_UINT32, BASE_DEC, NULL , 0x0,
NULL, HFILL }
},
{ &hf_mep_agi_type,
{ "AGI TYPE", "bfd.mep.agi.type",
FT_UINT8, BASE_DEC, NULL , 0x0,
NULL, HFILL }
},
{ &hf_mep_agi_len,
{ "AGI Length", "bfd.mep.agi.len",
FT_UINT8, BASE_DEC, NULL , 0x0,
NULL, HFILL }
},
{ &hf_mep_agi_val,
{ "AGI value", "bfd.mep.agi.val",
FT_STRING, BASE_NONE, NULL , 0x0,
NULL, HFILL }
},
{ &hf_section_interface_no,
{ "Interface Number", "bfd.mep.interface.no",
FT_UINT32, BASE_DEC, NULL , 0x0,
"MPLS-TP Interface Number", HFILL }
}
};
/* BFD Echo */
static hf_register_info hf_echo[] = {
{ &hf_bfd_echo,
{ "Echo", "bfd_echo",
FT_BYTES, BASE_NONE, NULL, 0x0,
"Originator specific echo packet", HFILL }
}
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_bfd,
&ett_bfd_flags,
&ett_bfd_auth,
&ett_bfd_echo
};
static ei_register_info ei[] = {
{ &ei_bfd_auth_len_invalid, { "bfd.auth.len.invalid", PI_MALFORMED, PI_WARN, "Length of authentication section is invalid", EXPFILL }},
{ &ei_bfd_auth_no_data, { "bfd.auth.no_data", PI_MALFORMED, PI_WARN, "Authentication flag is set in a BFD packet, but no authentication data is present", EXPFILL }},
};
expert_module_t* expert_bfd;
/* Register the protocol name and description */
proto_bfd = proto_register_protocol("Bidirectional Forwarding Detection Control Message",
"BFD Control",
"bfd");
proto_bfd_echo = proto_register_protocol("Bidirectional Forwarding Detection Echo Packet",
"BFD Echo",
"bfd_echo");
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_bfd, hf, array_length(hf));
proto_register_field_array(proto_bfd_echo, hf_echo, array_length(hf_echo));
proto_register_subtree_array(ett, array_length(ett));
expert_bfd = expert_register_protocol(proto_bfd);
expert_register_field_array(expert_bfd, ei, array_length(ei));
}
void
proto_reg_handoff_bfd(void)
{
dissector_handle_t bfd_control_handle;
dissector_handle_t bfd_echo_handle;
bfd_control_handle = create_dissector_handle(dissect_bfd_control, proto_bfd);
bfd_echo_handle = create_dissector_handle(dissect_bfd_echo, proto_bfd_echo);
dissector_add_uint_range_with_preference("udp.port", UDP_PORT_RANGE_BFD_CTRL, bfd_control_handle);
dissector_add_uint("udp.port", UDP_PORT_BFD_ECHO, bfd_echo_handle);
dissector_add_uint("pwach.channel_type", PW_ACH_TYPE_BFD_CC, bfd_control_handle);
dissector_add_uint("pwach.channel_type", PW_ACH_TYPE_BFD_CV, bfd_control_handle);
dissector_add_uint("pwach.channel_type", PW_ACH_TYPE_BFD, bfd_control_handle);
}
/*
* Editor modelines - https://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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