/* packet-igrp.c * Routines for IGRP dissection * Copyright 2000, Paul Ionescu * * See * * http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a00800c8ae1.shtml * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * Copied from packet-syslog.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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "config.h" #include #include #include #include void proto_register_igrp(void); void proto_reg_handoff_igrp(void); #define IGRP_HEADER_LENGTH 12 #define IGRP_ENTRY_LENGTH 14 static gint proto_igrp = -1; static gint hf_igrp_update = -1; static gint hf_igrp_as = -1; /* Generated from convert_proto_tree_add_text.pl */ static int hf_igrp_load = -1; static int hf_igrp_bandwidth = -1; static int hf_igrp_command = -1; static int hf_igrp_reliability = -1; static int hf_igrp_network = -1; static int hf_igrp_version = -1; static int hf_igrp_interior_routes = -1; static int hf_igrp_mtu = -1; static int hf_igrp_hop_count = -1; static int hf_igrp_exterior_routes = -1; static int hf_igrp_delay = -1; static int hf_igrp_checksum = -1; static int hf_igrp_system_routes = -1; static gint ett_igrp = -1; static gint ett_igrp_vektor = -1; static gint ett_igrp_net = -1; static expert_field ei_igrp_version = EI_INIT; static void dissect_vektor_igrp (tvbuff_t *tvb, proto_tree *igrp_vektor_tree, guint8 network); static int dissect_igrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { guint8 ver_and_opcode,version,opcode,network; gint offset=IGRP_HEADER_LENGTH; guint16 ninterior,nsystem,nexterior; const guint8 *ipsrc; proto_item *ti; proto_tree *igrp_tree, *igrp_vektor_tree; tvbuff_t *next_tvb; col_set_str(pinfo->cinfo, COL_PROTOCOL, "IGRP"); col_clear(pinfo->cinfo, COL_INFO); ver_and_opcode = tvb_get_guint8(tvb,0); switch (ver_and_opcode) { case 0x11: col_set_str(pinfo->cinfo, COL_INFO, "Response" ); break; case 0x12: col_set_str(pinfo->cinfo, COL_INFO, "Request" ); break; default: col_set_str(pinfo->cinfo, COL_INFO, "Unknown version or opcode"); } if (tree) { ti = proto_tree_add_protocol_format(tree, proto_igrp, tvb, 0, -1, "Cisco IGRP"); igrp_tree = proto_item_add_subtree(ti, ett_igrp); version = (ver_and_opcode&0xf0)>>4 ; /* version is the fist half of the byte */ opcode = ver_and_opcode&0x0f ; /* opcode is the last half of the byte */ ti = proto_tree_add_item(igrp_tree, hf_igrp_version, tvb, 0, 1, ENC_BIG_ENDIAN); if (version != 1) expert_add_info(pinfo, ti, &ei_igrp_version); ti = proto_tree_add_item(igrp_tree, hf_igrp_command, tvb, 0, 1, ENC_BIG_ENDIAN); if (opcode==1) proto_item_append_text(ti, " (Response)"); else proto_item_append_text(ti, " (Request)"); proto_tree_add_item(igrp_tree, hf_igrp_update, tvb, 1,1, ENC_BIG_ENDIAN); proto_tree_add_item(igrp_tree, hf_igrp_as, tvb, 2,2, ENC_BIG_ENDIAN); ninterior = tvb_get_ntohs(tvb,4); nsystem = tvb_get_ntohs(tvb,6); nexterior = tvb_get_ntohs(tvb,8); /* this is a ugly hack to find the first byte of the IP source address */ if (pinfo->net_src.type == AT_IPv4) { ipsrc = (const guint8 *)pinfo->net_src.data; network = ipsrc[0]; } else network = 0; /* XXX - shouldn't happen */ ti = proto_tree_add_item(igrp_tree, hf_igrp_interior_routes, tvb, 4, 2, ENC_BIG_ENDIAN); for( ; ninterior>0 ; ninterior-- ) { igrp_vektor_tree = proto_item_add_subtree(ti,ett_igrp_vektor); next_tvb = tvb_new_subset(tvb, offset, IGRP_ENTRY_LENGTH, -1); dissect_vektor_igrp (next_tvb,igrp_vektor_tree,network); offset+=IGRP_ENTRY_LENGTH; } ti = proto_tree_add_item(igrp_tree, hf_igrp_system_routes, tvb, 6, 2, ENC_BIG_ENDIAN); for( ; nsystem>0 ; nsystem-- ) { igrp_vektor_tree = proto_item_add_subtree(ti,ett_igrp_vektor); next_tvb = tvb_new_subset(tvb, offset, IGRP_ENTRY_LENGTH, -1); dissect_vektor_igrp (next_tvb,igrp_vektor_tree,0); offset+=IGRP_ENTRY_LENGTH; } ti = proto_tree_add_item(igrp_tree, hf_igrp_exterior_routes, tvb, 8, 2, ENC_BIG_ENDIAN); for( ; nexterior>0 ; nexterior-- ) { igrp_vektor_tree = proto_item_add_subtree(ti,ett_igrp_vektor); next_tvb = tvb_new_subset(tvb, offset, IGRP_ENTRY_LENGTH, -1); dissect_vektor_igrp (next_tvb,igrp_vektor_tree,0); offset+=IGRP_ENTRY_LENGTH; } proto_tree_add_item(igrp_tree, hf_igrp_checksum, tvb, 10, 2, ENC_BIG_ENDIAN); } return tvb_captured_length(tvb); } static void dissect_vektor_igrp (tvbuff_t *tvb, proto_tree *igrp_vektor_tree, guint8 network) { union { guint8 addr_bytes[4]; guint32 addr_word; } addr; address ip_addr; if (network != 0) { /* * Interior route; network is the high-order byte, and the three * bytes in the vector are the lower 3 bytes. */ addr.addr_bytes[0]=network; addr.addr_bytes[1]=tvb_get_guint8(tvb,0); addr.addr_bytes[2]=tvb_get_guint8(tvb,1); addr.addr_bytes[3]=tvb_get_guint8(tvb,2); } else { /* * System or exterior route; the three bytes in the vector are * the three high-order bytes, and the low-order byte is 0. */ addr.addr_bytes[0]=tvb_get_guint8(tvb,0); addr.addr_bytes[1]=tvb_get_guint8(tvb,1); addr.addr_bytes[2]=tvb_get_guint8(tvb,2); addr.addr_bytes[3]=0; } set_address(&ip_addr, AT_IPv4, 4, &addr); igrp_vektor_tree = proto_tree_add_subtree_format(igrp_vektor_tree, tvb, 0 ,14, ett_igrp_net, NULL, "Entry for network %s", address_to_str(wmem_packet_scope(), &ip_addr)); proto_tree_add_ipv4(igrp_vektor_tree, hf_igrp_network, tvb, 0, 3, addr.addr_word); proto_tree_add_item(igrp_vektor_tree, hf_igrp_delay, tvb, 3, 3, ENC_BIG_ENDIAN); proto_tree_add_item(igrp_vektor_tree, hf_igrp_bandwidth, tvb, 6, 3, ENC_BIG_ENDIAN); proto_tree_add_uint_format_value(igrp_vektor_tree, hf_igrp_mtu, tvb, 9, 2, tvb_get_ntohs(tvb,9), "%d bytes", tvb_get_ntohs(tvb,9)); proto_tree_add_item(igrp_vektor_tree, hf_igrp_reliability, tvb, 11, 1, ENC_BIG_ENDIAN); proto_tree_add_item(igrp_vektor_tree, hf_igrp_load, tvb, 12, 1, ENC_BIG_ENDIAN); proto_tree_add_item(igrp_vektor_tree, hf_igrp_hop_count, tvb, 13, 1, ENC_BIG_ENDIAN); } /* Register the protocol with Wireshark */ void proto_register_igrp(void) { /* Setup list of header fields */ static hf_register_info hf[] = { { &hf_igrp_update, { "Update Release", "igrp.update", FT_UINT8, BASE_DEC, NULL, 0x0 , "Update Release number", HFILL } }, { &hf_igrp_as, { "Autonomous System", "igrp.as", FT_UINT16, BASE_DEC, NULL, 0x0 , "Autonomous System number", HFILL } }, /* Generated from convert_proto_tree_add_text.pl */ { &hf_igrp_version, { "IGRP Version", "igrp.version", FT_UINT8, BASE_DEC, NULL, 0xF0, NULL, HFILL }}, { &hf_igrp_command, { "Command", "igrp.command", FT_UINT8, BASE_DEC, NULL, 0x0F, NULL, HFILL }}, { &hf_igrp_interior_routes, { "Interior routes", "igrp.interior_routes", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_system_routes, { "System routes", "igrp.system_routes", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_exterior_routes, { "Exterior routes", "igrp.exterior_routes", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_checksum, { "Checksum", "igrp.checksum", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_network, { "Network", "igrp.network", FT_IPv4, BASE_NONE, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_delay, { "Delay", "igrp.delay", FT_UINT24, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_bandwidth, { "Bandwidth", "igrp.bandwidth", FT_UINT24, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_mtu, { "MTU", "igrp.mtu", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_reliability, { "Reliability", "igrp.reliability", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_load, { "Load", "igrp.load", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}, { &hf_igrp_hop_count, { "Hop count", "igrp.hop_count", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_igrp, &ett_igrp_vektor, &ett_igrp_net }; static ei_register_info ei[] = { { &ei_igrp_version, { "igrp.version.invalid", PI_PROTOCOL, PI_WARN, "Unknown Version, The dissection may be inaccurate", EXPFILL }}, }; expert_module_t* expert_igrp; /* Register the protocol name and description */ proto_igrp = proto_register_protocol("Cisco Interior Gateway Routing Protocol", "IGRP", "igrp"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_igrp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); expert_igrp = expert_register_protocol(proto_igrp); expert_register_field_array(expert_igrp, ei, array_length(ei)); } void proto_reg_handoff_igrp(void) { dissector_handle_t igrp_handle; igrp_handle = create_dissector_handle(dissect_igrp, proto_igrp); dissector_add_uint("ip.proto", IP_PROTO_IGRP, igrp_handle); } /* IGRP Packet structure: HEADER structure + k * VECTOR structure where: k = (Number of Interior routes) + (Number of System routes) + (Number of Exterior routes) HEADER structure is 12 bytes as follows : 4 bits Version (only version 1 is defined) 4 bits Opcode (1=Replay, 2=Request) 8 bits Update Release 16 bits Autonomous system number 16 bits Number of Interior routes 16 bits Number of System routes 16 bits Number of Exterior routes 16 bits Checksum ------- 12 bytes in header VECTOR structure is 14 bytes as follows : 24 bits Network 24 bits Delay 24 bits Bandwidth 16 bits MTU 8 bits Reliability 8 bits Load 8 bits Hop count ------- 14 bytes in 1 vector It is interesting how is coded an ip network address in 3 bytes because IGRP is a classful routing protocol: If it is a interior route then this 3 bytes are the final bytes, and the first one is taken from the source ip address of the ip packet If it is a system route or a exterior route then this 3 bytes are the first three and the last byte is not important If the Delay is 0xFFFFFF then the network is unreachable */ /* * 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: */