forked from osmocom/wireshark
240 lines
8.9 KiB
C
240 lines
8.9 KiB
C
/* packet-hsrp.c
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* Routines for the Cisco Hot Standby Router Protocol (HSRP)
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* RFC 2281
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*
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* Heikki Vatiainen <hessu@cs.tut.fi>
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*
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* $Id: packet-hsrp.c,v 1.24 2002/08/28 21:00:16 jmayer Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@ethereal.com>
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* Copyright 1998 Gerald Combs
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*
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* Copied from packet-vrrp.c
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#include <string.h>
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#include <glib.h>
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#include <epan/packet.h>
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static gint proto_hsrp = -1;
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static gint hf_hsrp_version = -1;
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static gint hf_hsrp_opcode = -1;
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static gint hf_hsrp_state = -1;
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static gint hf_hsrp_hellotime = -1;
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static gint hf_hsrp_holdtime = -1;
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static gint hf_hsrp_priority = -1;
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static gint hf_hsrp_group = -1;
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static gint hf_hsrp_reserved = -1;
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static gint hf_hsrp_auth_data = -1;
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static gint hf_hsrp_virt_ip_addr = -1;
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static gint ett_hsrp = -1;
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#define UDP_PORT_HSRP 1985
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struct hsrp_packet { /* Multicast to 224.0.0.2, TTL 1, UDP, port 1985 */
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guint8 version; /* RFC2281 describes version 0 */
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guint8 opcode;
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guint8 state;
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#define HSRP_DEFAULT_HELLOTIME 3
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guint8 hellotime; /* In seconds */
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#define HSRP_DEFAULT_HOLDTIME 10
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guint8 holdtime; /* In seconds */
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guint8 priority; /* Higher is stronger, highest IP address tie-breaker */
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guint8 group; /* Identifies the standby group */
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guint8 reserved;
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guint8 auth_data[8]; /* Clear-text password, recommended default is `cisco' */
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guint32 virt_ip_addr; /* The virtual IP address used by this group */
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};
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#define HSRP_OPCODE_HELLO 0
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#define HSRP_OPCODE_COUP 1
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#define HSRP_OPCODE_RESIGN 2
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static const value_string hsrp_opcode_vals[] = {
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{HSRP_OPCODE_HELLO, "Hello"},
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{HSRP_OPCODE_COUP, "Coup"},
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{HSRP_OPCODE_RESIGN, "Resign"},
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{0, NULL},
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};
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#define HSRP_STATE_INITIAL 0
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#define HSRP_STATE_LEARN 1
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#define HSRP_STATE_LISTEN 2
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#define HSRP_STATE_SPEAK 4
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#define HSRP_STATE_STANDBY 8
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#define HSRP_STATE_ACTIVE 16
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static const value_string hsrp_state_vals[] = {
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{HSRP_STATE_INITIAL, "Initial"},
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{HSRP_STATE_LEARN, "Learn"},
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{HSRP_STATE_LISTEN, "Listen"},
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{HSRP_STATE_SPEAK, "Speak"},
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{HSRP_STATE_STANDBY, "Standby"},
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{HSRP_STATE_ACTIVE, "Active"},
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{0, NULL},
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};
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static void
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dissect_hsrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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guint8 opcode, state;
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if (check_col(pinfo->cinfo, COL_PROTOCOL))
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "HSRP");
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if (check_col(pinfo->cinfo, COL_INFO))
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col_clear(pinfo->cinfo, COL_INFO);
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opcode = tvb_get_guint8(tvb, 1);
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state = tvb_get_guint8(tvb, 2);
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if (check_col(pinfo->cinfo, COL_INFO)) {
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col_add_fstr(pinfo->cinfo, COL_INFO, "%s (state %s)",
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val_to_str(opcode, hsrp_opcode_vals, "Unknown"),
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val_to_str(state, hsrp_state_vals, "Unknown"));
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}
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if (tree) {
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proto_item *ti;
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proto_tree *hsrp_tree;
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int offset;
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guint8 hellotime, holdtime;
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guint8 auth_buf[8 + 1];
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offset = 0;
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ti = proto_tree_add_item(tree, proto_hsrp, tvb, offset, -1, FALSE);
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hsrp_tree = proto_item_add_subtree(ti, ett_hsrp);
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proto_tree_add_item(hsrp_tree, hf_hsrp_version, tvb, offset, 1, FALSE);
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offset++;
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proto_tree_add_uint(hsrp_tree, hf_hsrp_opcode, tvb, offset, 1, opcode);
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offset++;
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proto_tree_add_uint(hsrp_tree, hf_hsrp_state, tvb, offset, 1, state);
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offset++;
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hellotime = tvb_get_guint8(tvb, offset);
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proto_tree_add_uint_format(hsrp_tree, hf_hsrp_hellotime, tvb, offset, 1, hellotime,
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"Hellotime: %sDefault (%u)",
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(hellotime == HSRP_DEFAULT_HELLOTIME) ? "" : "Non-",
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hellotime);
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offset++;
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holdtime = tvb_get_guint8(tvb, offset);
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proto_tree_add_uint_format(hsrp_tree, hf_hsrp_holdtime, tvb, offset, 1, holdtime,
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"Holdtime: %sDefault (%u)",
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(holdtime == HSRP_DEFAULT_HOLDTIME) ? "" : "Non-",
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holdtime);
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offset++;
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proto_tree_add_item(hsrp_tree, hf_hsrp_priority, tvb, offset, 1, FALSE);
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offset++;
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proto_tree_add_item(hsrp_tree, hf_hsrp_group, tvb, offset, 1, FALSE);
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offset++;
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proto_tree_add_item(hsrp_tree, hf_hsrp_reserved, tvb, offset, 1, FALSE);
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offset++;
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tvb_memcpy(tvb, auth_buf, offset, 8);
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auth_buf[sizeof auth_buf - 1] = '\0';
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proto_tree_add_string_format(hsrp_tree, hf_hsrp_auth_data, tvb, offset, 8, auth_buf,
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"Authentication Data: %sDefault (%s)",
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(tvb_strneql(tvb, offset, "cisco", strlen("cisco"))) == 0 ? "" : "Non-",
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auth_buf);
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offset += 8;
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proto_tree_add_item(hsrp_tree, hf_hsrp_virt_ip_addr, tvb, offset, 4, FALSE);
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offset += 4;
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}
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return;
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}
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void proto_register_hsrp(void)
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{
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static hf_register_info hf[] = {
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{ &hf_hsrp_version,
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{ "Version", "hsrp.version",
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FT_UINT8, BASE_DEC, NULL, 0x0,
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"The version of the HSRP messages", HFILL }},
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{ &hf_hsrp_opcode,
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{ "Op Code", "hsrp.opcode",
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FT_UINT8, BASE_DEC, VALS(hsrp_opcode_vals), 0x0,
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"The type of message contained in this packet", HFILL }},
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{ &hf_hsrp_state,
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{ "State", "hsrp.state",
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FT_UINT8, BASE_DEC, VALS(hsrp_state_vals), 0x0,
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"The current state of the router sending the message", HFILL }},
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{ &hf_hsrp_hellotime,
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{ "Hellotime", "hsrp.hellotime",
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FT_UINT8, BASE_DEC, NULL, 0x0,
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"The approximate period between the Hello messages that the router sends", HFILL }},
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{ &hf_hsrp_holdtime,
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{ "Holdtime", "hsrp.holdtime",
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FT_UINT8, BASE_DEC, NULL, 0x0,
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"Time that the current Hello message should be considered valid", HFILL }},
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{ &hf_hsrp_priority,
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{ "Priority", "hsrp.priority",
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FT_UINT8, BASE_DEC, NULL, 0x0,
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"Used to elect the active and standby routers. Numerically higher priority wins vote", HFILL }},
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{ &hf_hsrp_group,
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{ "Group", "hsrp.group",
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FT_UINT8, BASE_DEC, NULL, 0x0,
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"This field identifies the standby group", HFILL }},
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{ &hf_hsrp_reserved,
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{ "Reserved", "hsrp.reserved",
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FT_UINT8, BASE_DEC, NULL, 0x0,
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"Reserved", HFILL }},
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{ &hf_hsrp_auth_data,
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{ "Authentication Data", "hsrp.auth_data",
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FT_STRING, 0, NULL, 0x0,
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"Contains a clear-text 8 character reused password", HFILL }},
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{ &hf_hsrp_virt_ip_addr,
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{ "Virtual IP Address", "hsrp.virt_ip",
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FT_IPv4, 0, NULL, 0x0,
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"The virtual IP address used by this group", HFILL }},
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};
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static gint *ett[] = {
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&ett_hsrp,
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};
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proto_hsrp = proto_register_protocol("Cisco Hot Standby Router Protocol",
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"HSRP", "hsrp");
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proto_register_field_array(proto_hsrp, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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return;
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}
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void
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proto_reg_handoff_hsrp(void)
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{
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dissector_handle_t hsrp_handle;
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hsrp_handle = create_dissector_handle(dissect_hsrp, proto_hsrp);
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dissector_add("udp.port", UDP_PORT_HSRP, hsrp_handle);
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}
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