/* packet-hsrp.c * Routines for the Cisco Hot Standby Router Protocol (HSRP) * RFC 2281 * * Heikki Vatiainen * * $Id: packet-hsrp.c,v 1.24 2002/08/28 21:00:16 jmayer Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs * 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. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include static gint proto_hsrp = -1; static gint hf_hsrp_version = -1; static gint hf_hsrp_opcode = -1; 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; 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 static const value_string hsrp_opcode_vals[] = { {HSRP_OPCODE_HELLO, "Hello"}, {HSRP_OPCODE_COUP, "Coup"}, {HSRP_OPCODE_RESIGN, "Resign"}, {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}, }; static void dissect_hsrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { guint8 opcode, state; if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "HSRP"); if (check_col(pinfo->cinfo, COL_INFO)) col_clear(pinfo->cinfo, COL_INFO); opcode = tvb_get_guint8(tvb, 1); state = tvb_get_guint8(tvb, 2); if (check_col(pinfo->cinfo, COL_INFO)) { col_add_fstr(pinfo->cinfo, COL_INFO, "%s (state %s)", val_to_str(opcode, hsrp_opcode_vals, "Unknown"), val_to_str(state, hsrp_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++; 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; } return; } 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 }}, }; 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; hsrp_handle = create_dissector_handle(dissect_hsrp, proto_hsrp); dissector_add("udp.port", UDP_PORT_HSRP, hsrp_handle); }