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|
/* packet-hsrp.c
* Routines for the Cisco Hot Standby Router Protocol (HSRP)
*
* Heikki Vatiainen <hessu@cs.tut.fi>
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* Copied from packet-vrrp.c
*
* 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.
*/
/*
* RFC 2281 describes opcodes 0 - 2
*
* Op Code 3: **** HSRP Interface State Advertisements ****
* http://www.cisco.com/en/US/products/sw/iosswrel/ps1834/products_feature_guide09186a00800e9763.html
*
* An HSRP interface-state advertisement is sent:
*
* * when HSRP on the interface enters or leaves the passive state
* * when a group on the interface learns a new Active router
* * periodically while the interface is in the passive state
*
* 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
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Version | Op Code = 3 | TLV Type |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | TLV Length | State | Reserved |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Active Group Count | Passive Group Count |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Reserved |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Passive Group Count: 2 octet
*
* A count of the number of passive groups on the interface. The range
* of values are 0-256.
*
* Active Group Count: 2 octet
*
* A count of the number of active groups on the interface. The range
* of values are 0-256.
*
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <string.h>
#include <glib.h>
#include <epan/packet.h>
static gint proto_hsrp = -1;
static dissector_handle_t data_handle;
static gint hf_hsrp_version = -1;
static gint hf_hsrp_opcode = -1;
/* Opcode 0-2 */
static gint hf_hsrp_state = -1;
static gint hf_hsrp_hellotime = -1;
static gint hf_hsrp_holdtime = -1;
static gint hf_hsrp_priority = -1;
static gint hf_hsrp_group = -1;
static gint hf_hsrp_reserved = -1;
static gint hf_hsrp_auth_data = -1;
static gint hf_hsrp_virt_ip_addr = -1;
/* Advertise (3) */
static gint hf_hsrp_adv_type = -1;
static gint hf_hsrp_adv_length = -1;
static gint hf_hsrp_adv_state = -1;
static gint hf_hsrp_adv_reserved1 = -1;
static gint hf_hsrp_adv_activegrp = -1;
static gint hf_hsrp_adv_passivegrp = -1;
static gint hf_hsrp_adv_reserved2 = -1;
static gint ett_hsrp = -1;
#define UDP_PORT_HSRP 1985
struct hsrp_packet { /* Multicast to 224.0.0.2, TTL 1, UDP, port 1985 */
guint8 version; /* RFC2281 describes version 0 */
guint8 opcode;
guint8 state;
#define HSRP_DEFAULT_HELLOTIME 3
guint8 hellotime; /* In seconds */
#define HSRP_DEFAULT_HOLDTIME 10
guint8 holdtime; /* In seconds */
guint8 priority; /* Higher is stronger, highest IP address tie-breaker */
guint8 group; /* Identifies the standby group */
guint8 reserved;
guint8 auth_data[8]; /* Clear-text password, recommended default is `cisco' */
guint32 virt_ip_addr; /* The virtual IP address used by this group */
};
#define HSRP_OPCODE_HELLO 0
#define HSRP_OPCODE_COUP 1
#define HSRP_OPCODE_RESIGN 2
#define HSRP_OPCODE_ADVERTISE 3
static const value_string hsrp_opcode_vals[] = {
{HSRP_OPCODE_HELLO, "Hello"},
{HSRP_OPCODE_COUP, "Coup"},
{HSRP_OPCODE_RESIGN, "Resign"},
{HSRP_OPCODE_ADVERTISE, "Advertise"},
{0, NULL},
};
#define HSRP_STATE_INITIAL 0
#define HSRP_STATE_LEARN 1
#define HSRP_STATE_LISTEN 2
#define HSRP_STATE_SPEAK 4
#define HSRP_STATE_STANDBY 8
#define HSRP_STATE_ACTIVE 16
static const value_string hsrp_state_vals[] = {
{HSRP_STATE_INITIAL, "Initial"},
{HSRP_STATE_LEARN, "Learn"},
{HSRP_STATE_LISTEN, "Listen"},
{HSRP_STATE_SPEAK, "Speak"},
{HSRP_STATE_STANDBY, "Standby"},
{HSRP_STATE_ACTIVE, "Active"},
{0, NULL},
};
#define HSRP_ADV_TYPE_INTSTATE 1
#define HSRP_ADV_TYPE_IPREDUN 2
static const value_string hsrp_adv_type_vals[] = {
{HSRP_ADV_TYPE_INTSTATE, "HSRP interface state"},
{HSRP_ADV_TYPE_IPREDUN, "IP redundancy"},
{0, NULL},
};
#define HSRP_ADV_STATE_DORMANT 1
#define HSRP_ADV_STATE_PASSIVE 2
#define HSRP_ADV_STATE_ACTIVE 3
static const value_string hsrp_adv_state_vals[] = {
{HSRP_ADV_STATE_DORMANT, "Dormant"},
{HSRP_ADV_STATE_PASSIVE, "Passive"},
{HSRP_ADV_STATE_ACTIVE, "Active"},
{0, NULL},
};
static int
dissect_hsrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
guint8 opcode, state = 0;
tvbuff_t *next_tvb;
/* Return if this isn't really HSRP traffic
* (source and destination port must be UDP_PORT_HSRP) */
if(pinfo->destport != UDP_PORT_HSRP)
return 0;
if (check_col(pinfo->cinfo, COL_PROTOCOL))
col_set_str(pinfo->cinfo, COL_PROTOCOL, "HSRP");
opcode = tvb_get_guint8(tvb, 1);
if (check_col(pinfo->cinfo, COL_INFO)) {
col_add_fstr(pinfo->cinfo, COL_INFO, "%s",
val_to_str(opcode, hsrp_opcode_vals, "Unknown"));
}
if (opcode < 3) {
state = tvb_get_guint8(tvb, 2);
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, " (state %s)",
val_to_str(state, hsrp_state_vals, "Unknown"));
}
} else if (opcode == 3) {
state = tvb_get_guint8(tvb, 6);
if (check_col(pinfo->cinfo, COL_INFO)) {
col_append_fstr(pinfo->cinfo, COL_INFO, " (state %s)",
val_to_str(state, hsrp_adv_state_vals, "Unknown"));
}
}
if (tree) {
proto_item *ti;
proto_tree *hsrp_tree;
int offset;
guint8 hellotime, holdtime;
guint8 auth_buf[8 + 1];
offset = 0;
ti = proto_tree_add_item(tree, proto_hsrp, tvb, offset, -1, FALSE);
hsrp_tree = proto_item_add_subtree(ti, ett_hsrp);
proto_tree_add_item(hsrp_tree, hf_hsrp_version, tvb, offset, 1, FALSE);
offset++;
proto_tree_add_uint(hsrp_tree, hf_hsrp_opcode, tvb, offset, 1, opcode);
offset++;
if (opcode < 3) {
proto_tree_add_uint(hsrp_tree, hf_hsrp_state, tvb, offset, 1, state);
offset++;
hellotime = tvb_get_guint8(tvb, offset);
proto_tree_add_uint_format(hsrp_tree, hf_hsrp_hellotime, tvb, offset, 1, hellotime,
"Hellotime: %sDefault (%u)",
(hellotime == HSRP_DEFAULT_HELLOTIME) ? "" : "Non-",
hellotime);
offset++;
holdtime = tvb_get_guint8(tvb, offset);
proto_tree_add_uint_format(hsrp_tree, hf_hsrp_holdtime, tvb, offset, 1, holdtime,
"Holdtime: %sDefault (%u)",
(holdtime == HSRP_DEFAULT_HOLDTIME) ? "" : "Non-",
holdtime);
offset++;
proto_tree_add_item(hsrp_tree, hf_hsrp_priority, tvb, offset, 1, FALSE);
offset++;
proto_tree_add_item(hsrp_tree, hf_hsrp_group, tvb, offset, 1, FALSE);
offset++;
proto_tree_add_item(hsrp_tree, hf_hsrp_reserved, tvb, offset, 1, FALSE);
offset++;
tvb_memcpy(tvb, auth_buf, offset, 8);
auth_buf[sizeof auth_buf - 1] = '\0';
proto_tree_add_string_format(hsrp_tree, hf_hsrp_auth_data, tvb, offset, 8, auth_buf,
"Authentication Data: %sDefault (%s)",
(tvb_strneql(tvb, offset, "cisco", strlen("cisco"))) == 0 ? "" : "Non-",
auth_buf);
offset += 8;
proto_tree_add_item(hsrp_tree, hf_hsrp_virt_ip_addr, tvb, offset, 4, FALSE);
offset += 4;
} else if (opcode == 3) {
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_type, tvb, offset, 2, FALSE);
offset += 2;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_length, tvb, offset, 2, FALSE);
offset += 2;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_state, tvb, offset, 1, FALSE);
offset += 1;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_reserved1, tvb, offset, 1, FALSE);
offset += 1;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_activegrp, tvb, offset, 2, FALSE);
offset += 2;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_passivegrp, tvb, offset, 2, FALSE);
offset += 2;
proto_tree_add_item(hsrp_tree, hf_hsrp_adv_reserved2, tvb, offset, 4, FALSE);
offset += 4;
} else {
next_tvb = tvb_new_subset(tvb, offset, -1, -1);
call_dissector(data_handle, next_tvb, pinfo, hsrp_tree);
}
}
return tvb_length(tvb);
}
void proto_register_hsrp(void)
{
static hf_register_info hf[] = {
{ &hf_hsrp_version,
{ "Version", "hsrp.version",
FT_UINT8, BASE_DEC, NULL, 0x0,
"The version of the HSRP messages", HFILL }},
{ &hf_hsrp_opcode,
{ "Op Code", "hsrp.opcode",
FT_UINT8, BASE_DEC, VALS(hsrp_opcode_vals), 0x0,
"The type of message contained in this packet", HFILL }},
{ &hf_hsrp_state,
{ "State", "hsrp.state",
FT_UINT8, BASE_DEC, VALS(hsrp_state_vals), 0x0,
"The current state of the router sending the message", HFILL }},
{ &hf_hsrp_hellotime,
{ "Hellotime", "hsrp.hellotime",
FT_UINT8, BASE_DEC, NULL, 0x0,
"The approximate period between the Hello messages that the router sends", HFILL }},
{ &hf_hsrp_holdtime,
{ "Holdtime", "hsrp.holdtime",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Time that the current Hello message should be considered valid", HFILL }},
{ &hf_hsrp_priority,
{ "Priority", "hsrp.priority",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Used to elect the active and standby routers. Numerically higher priority wins vote", HFILL }},
{ &hf_hsrp_group,
{ "Group", "hsrp.group",
FT_UINT8, BASE_DEC, NULL, 0x0,
"This field identifies the standby group", HFILL }},
{ &hf_hsrp_reserved,
{ "Reserved", "hsrp.reserved",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Reserved", HFILL }},
{ &hf_hsrp_auth_data,
{ "Authentication Data", "hsrp.auth_data",
FT_STRING, 0, NULL, 0x0,
"Contains a clear-text 8 character reused password", HFILL }},
{ &hf_hsrp_virt_ip_addr,
{ "Virtual IP Address", "hsrp.virt_ip",
FT_IPv4, 0, NULL, 0x0,
"The virtual IP address used by this group", HFILL }},
{ &hf_hsrp_adv_type,
{ "Adv type", "hsrp.adv.tlvtype",
FT_UINT16, BASE_DEC, VALS(hsrp_adv_type_vals), 0x0,
"Advertisement tlv type", HFILL }},
{ &hf_hsrp_adv_length,
{ "Adv length", "hsrp.adv.tlvlength",
FT_UINT16, BASE_DEC, NULL, 0x0,
"Advertisement tlv length", HFILL }},
{ &hf_hsrp_adv_state,
{ "Adv state", "hsrp.adv.state",
FT_UINT8, BASE_DEC, VALS(hsrp_adv_state_vals), 0x0,
"Advertisement tlv length", HFILL }},
{ &hf_hsrp_adv_reserved1,
{ "Adv reserved1", "hsrp.adv.reserved1",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Advertisement tlv length", HFILL }},
{ &hf_hsrp_adv_activegrp,
{ "Adv active groups", "hsrp.adv.activegrp",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Advertisement active group count", HFILL }},
{ &hf_hsrp_adv_passivegrp,
{ "Adv passive groups", "hsrp.adv.passivegrp",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Advertisement passive group count", HFILL }},
{ &hf_hsrp_adv_reserved2,
{ "Adv reserved2", "hsrp.adv.reserved2",
FT_UINT32, BASE_DEC, NULL, 0x0,
"Advertisement tlv length", HFILL }},
};
static gint *ett[] = {
&ett_hsrp,
};
proto_hsrp = proto_register_protocol("Cisco Hot Standby Router Protocol",
"HSRP", "hsrp");
proto_register_field_array(proto_hsrp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
return;
}
void
proto_reg_handoff_hsrp(void)
{
dissector_handle_t hsrp_handle;
data_handle = find_dissector("data");
hsrp_handle = new_create_dissector_handle(dissect_hsrp, proto_hsrp);
dissector_add("udp.port", UDP_PORT_HSRP, hsrp_handle);
}
|
