/* packet-erspan.c * Routines for the disassembly of Cisco's ERSPAN protocol * * $Id$ * * Copyright 2005 Joerg Mayer (see AUTHORS file) * Updates for newer versions by Jason Masker * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * 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. */ /* * TODO: * Find out the Unknown values * * Specs: * No real specs exist. Some general description can be found at: * http://www.cisco.com/en/US/products/hw/routers/ps368/products_configuration_guide_chapter09186a008069952a.html * * Some information on ERSPAN type III can be found at: * http://www.cisco.com/en/US/docs/switches/datacenter/nexus1000/sw/4_0_4_s_v_1_3/system_management/configuration/guide/n1000v_system_9span.html * * For ERSPAN packets, the "protocol type" field value in the GRE header * is 0x88BE (version 1) or 0x22EB (version 2). * * ERSPAN type II is version 1 * ERSPAN type III is version 2 * * 0000000: d4c3 b2a1 0200 0400 0000 0000 0000 0000 <-- pcap header * 0000010: ffff 0000 * 0000010: 7100 0000 <-- 0x71 (DLT_TYPE) = linux_cooked_capture (of course not) * 0000010: 7507 f845 11d1 0500 <-- pcap record header * 0000020: 7a00 0000 7a00 0000 * 0000020: 0000 030a 0000 0000 <-- unknown * 0000030: 0000 0000 * 0000030: 0000 88be <-- GRE header (version 1) * 0000030: 1002 0001 0000 0380 <-- ERSPAN header (01: erspan-id) * 0000040: 00d0 b7a7 7480 0015 c721 75c0 0800 4500 <-- Ethernet packet * ... * * */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include #include #include static int proto_erspan = -1; static gint ett_erspan = -1; static int hf_erspan_version = -1; static int hf_erspan_vlan = -1; static int hf_erspan_priority = -1; static int hf_erspan_unknown2 = -1; static int hf_erspan_direction = -1; static int hf_erspan_unknown3 = -1; static int hf_erspan_truncated = -1; static int hf_erspan_spanid = -1; static int hf_erspan_timestamp = -1; static int hf_erspan_unknown4 = -1; static int hf_erspan_direction2 = -1; static int hf_erspan_unknown5 = -1; static int hf_erspan_unknown6 = -1; static int hf_erspan_unknown7 = -1; #define PROTO_SHORT_NAME "ERSPAN" #define PROTO_LONG_NAME "Encapsulated Remote Switch Packet ANalysis" /* Global ERSPAN Preference */ static gboolean pref_fake_erspan = FALSE; #define ERSPAN_DIRECTION_INCOMING 0 #define ERSPAN_DIRECTION_OUTGOING 1 static const value_string erspan_direction_vals[] = { {ERSPAN_DIRECTION_INCOMING, "Incoming"}, {ERSPAN_DIRECTION_OUTGOING, "Outgoing"}, {0, NULL}, }; static const value_string erspan_truncated_vals[] = { {0, "Not truncated"}, {1, "Truncated"}, {0, NULL}, }; static const value_string erspan_version_vals[] = { {1, "Type II"}, {2, "Type III"}, {0, NULL}, }; static dissector_handle_t ethnofcs_handle; static void erspan_fmt_timestamp(gchar *result, guint32 timeval) { g_snprintf(result, ITEM_LABEL_LENGTH, "%.4f", (((gfloat)timeval)/10000)); } static void dissect_erspan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_item *ti; proto_item *ti_ver; proto_tree *erspan_tree = NULL; tvbuff_t *eth_tvb; guint32 offset = 0; guint16 version = 0; col_set_str(pinfo->cinfo, COL_PROTOCOL, PROTO_SHORT_NAME); col_set_str(pinfo->cinfo, COL_INFO, PROTO_SHORT_NAME ":"); if (tree) { ti = proto_tree_add_item(tree, proto_erspan, tvb, offset, -1, ENC_NA); erspan_tree = proto_item_add_subtree(ti, ett_erspan); } if(pref_fake_erspan) { /* Some vendor don't include ERSPAN Header...*/ eth_tvb = tvb_new_subset_remaining(tvb, offset); call_dissector(ethnofcs_handle, eth_tvb, pinfo, tree); return; } if (tree) { version = tvb_get_ntohs(tvb, offset) >> 12; ti_ver = proto_tree_add_item(erspan_tree, hf_erspan_version, tvb, offset, 2, ENC_BIG_ENDIAN); if ((version != 1) && (version != 2 )) { expert_add_info_format(pinfo, ti_ver, PI_UNDECODED, PI_WARN, "Unknown version, please report or test to use fake ERSPAN preference"); return; } proto_tree_add_item(erspan_tree, hf_erspan_vlan, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; proto_tree_add_item(erspan_tree, hf_erspan_priority, tvb, offset, 2, ENC_BIG_ENDIAN); proto_tree_add_item(erspan_tree, hf_erspan_unknown2, tvb, offset, 2, ENC_BIG_ENDIAN); if (version == 1) proto_tree_add_item(erspan_tree, hf_erspan_direction, tvb, offset, 2, ENC_BIG_ENDIAN); else /* version = 2 */ proto_tree_add_item(erspan_tree, hf_erspan_unknown3, tvb, offset, 2, ENC_BIG_ENDIAN); proto_tree_add_item(erspan_tree, hf_erspan_truncated, tvb, offset, 2, ENC_BIG_ENDIAN); proto_tree_add_item(erspan_tree, hf_erspan_spanid, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; if (version == 2) { proto_tree_add_item(erspan_tree, hf_erspan_timestamp, tvb, offset, 4, ENC_BIG_ENDIAN); offset += 4; proto_tree_add_item(erspan_tree, hf_erspan_unknown4, tvb, offset, 2, ENC_NA); offset += 2; proto_tree_add_item(erspan_tree, hf_erspan_direction2, tvb, offset, 2, ENC_BIG_ENDIAN); proto_tree_add_item(erspan_tree, hf_erspan_unknown5, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; proto_tree_add_item(erspan_tree, hf_erspan_unknown6, tvb, offset, 4, ENC_NA); offset += 4; } proto_tree_add_item(erspan_tree, hf_erspan_unknown7, tvb, offset, 4, ENC_NA); offset += 4; } else { offset += 8; if (version == 2) offset += 12; } eth_tvb = tvb_new_subset_remaining(tvb, offset); call_dissector(ethnofcs_handle, eth_tvb, pinfo, tree); } void proto_register_erspan(void) { module_t *erspan_module; static hf_register_info hf[] = { { &hf_erspan_version, { "Version", "erspan.version", FT_UINT16, BASE_DEC, VALS(erspan_version_vals), 0xf000, NULL, HFILL }}, { &hf_erspan_vlan, { "Vlan", "erspan.vlan", FT_UINT16, BASE_DEC, NULL, 0x0fff, NULL, HFILL }}, { &hf_erspan_priority, { "Priority", "erspan.priority", FT_UINT16, BASE_DEC, NULL, 0xe000, NULL, HFILL }}, { &hf_erspan_unknown2, { "Unknown2", "erspan.unknown2", FT_UINT16, BASE_DEC, NULL, 0x1000, NULL, HFILL }}, { &hf_erspan_direction, { "Direction", "erspan.direction", FT_UINT16, BASE_DEC, VALS(erspan_direction_vals), 0x0800, NULL, HFILL }}, { &hf_erspan_unknown3, { "Unknown3", "erspan.unknown3", FT_UINT16, BASE_DEC, NULL, 0x0800, NULL, HFILL }}, { &hf_erspan_truncated, { "Truncated", "erspan.truncated", FT_UINT16, BASE_DEC, VALS(erspan_truncated_vals), 0x0400, "ERSPAN packet exceeded the MTU size", HFILL }}, { &hf_erspan_spanid, { "SpanID", "erspan.spanid", FT_UINT16, BASE_DEC, NULL, 0x03ff, NULL, HFILL }}, { &hf_erspan_timestamp, { "Timestamp", "erspan.timestamp", FT_UINT32, BASE_CUSTOM, erspan_fmt_timestamp, 0, NULL, HFILL }}, { &hf_erspan_unknown4, { "Unknown4", "erspan.unknown4", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, { &hf_erspan_direction2, { "Direction2", "erspan.direction2", FT_UINT16, BASE_DEC, VALS(erspan_direction_vals), 0x0008, NULL, HFILL }}, { &hf_erspan_unknown5, { "Unknown5", "erspan.unknown5", FT_UINT16, BASE_HEX, NULL, 0xfff7, NULL, HFILL }}, { &hf_erspan_unknown6, { "Unknown6", "erspan.unknown6", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, { &hf_erspan_unknown7, { "Unknown7", "erspan.unknown7", FT_BYTES, BASE_NONE, NULL, 0, NULL, HFILL }}, }; static gint *ett[] = { &ett_erspan, }; proto_erspan = proto_register_protocol(PROTO_LONG_NAME, PROTO_SHORT_NAME, "erspan"); proto_register_field_array(proto_erspan, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); /* register dissection preferences */ erspan_module = prefs_register_protocol(proto_erspan, NULL); prefs_register_bool_preference(erspan_module, "fake_erspan", "FORCE to decode fake ERSPAN frame", "When set, dissector will FORCE to decode directly Ethernet Frame" "Some vendor use fake ERSPAN frame (with not ERSPAN Header)", &pref_fake_erspan); } void proto_reg_handoff_erspan(void) { dissector_handle_t erspan_handle; ethnofcs_handle = find_dissector("eth_withoutfcs"); erspan_handle = create_dissector_handle(dissect_erspan, proto_erspan); dissector_add_uint("gre.proto", GRE_ERSPAN_88BE, erspan_handle); dissector_add_uint("gre.proto", GRE_ERSPAN_22EB, erspan_handle); }