/* packet-ieee8021ah.c * Routines for 802.1ah ethernet header disassembly * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ #include "config.h" #include #include #include #include #include "packet-ipx.h" #include "packet-llc.h" #include #include void proto_register_ieee8021ah(void); void proto_reg_handoff_ieee8021ah(void); static dissector_handle_t ieee8021ah_handle; static dissector_handle_t ieee8021ad_handle; static dissector_handle_t ethertype_handle; static capture_dissector_handle_t ipx_cap_handle; static capture_dissector_handle_t llc_cap_handle; static void dissect_ieee8021ah_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_tree *parent, int tree_index); /* GLOBALS ************************************************************/ /* ethertype for 802.1ah tag - encapsulating an Ethernet packet */ static unsigned int ieee8021ah_ethertype = ETHERTYPE_IEEE_802_1AH; static int proto_ieee8021ah; static int proto_ieee8021ad; /* dot1ad B-tag fields */ static int hf_ieee8021ad_priority; static int hf_ieee8021ad_cfi; static int hf_ieee8021ad_id; static int hf_ieee8021ad_svid; static int hf_ieee8021ad_cvid; /* dot1ah C-tag fields */ static int hf_ieee8021ah_priority; static int hf_ieee8021ah_drop; /* drop eligibility */ static int hf_ieee8021ah_nca; /* no customer addresses (c_daddr & c_saddr are 0) */ static int hf_ieee8021ah_res1; /* 2 bits reserved; ignored on receive */ static int hf_ieee8021ah_res2; /* 2 bits reserved; delete frame if non-zero */ static int hf_ieee8021ah_isid; /* I-SID */ static int hf_ieee8021ah_c_daddr; /* encapsulated customer dest addr */ static int hf_ieee8021ah_c_saddr; /* encapsulated customer src addr */ static int hf_ieee8021ah_etype; /* static int hf_ieee8021ah_len; */ static int hf_ieee8021ah_trailer; static int ett_ieee8021ah; static int ett_ieee8021ad; #define IEEE8021AD_LEN 4 #define IEEE8021AH_LEN 18 #define IEEE8021AH_ISIDMASK 0x00FFFFFF /* FUNCTIONS ************************************************************/ static bool capture_ieee8021ah(const unsigned char *pd, int offset, int len, capture_packet_info_t *cpinfo, const union wtap_pseudo_header *pseudo_header _U_) { uint16_t encap_proto; if (!BYTES_ARE_IN_FRAME(offset, len, IEEE8021AH_LEN + 1)) return false; encap_proto = pntoh16( &pd[offset + IEEE8021AH_LEN - 2] ); if (encap_proto <= IEEE_802_3_MAX_LEN) { if ( pd[offset + IEEE8021AH_LEN] == 0xff && pd[offset + IEEE8021AH_LEN + 1] == 0xff ) { return call_capture_dissector(ipx_cap_handle, pd, offset + IEEE8021AH_LEN, len, cpinfo, pseudo_header); } else { return call_capture_dissector(llc_cap_handle, pd, offset + IEEE8021AH_LEN, len, cpinfo, pseudo_header); } } return try_capture_dissector("ethertype", encap_proto, pd, offset + IEEE8021AH_LEN, len, cpinfo, pseudo_header); } /* Dissector *************************************************************/ static int dissect_ieee8021ad(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { proto_tree *ptree = NULL; proto_tree *tagtree = NULL; uint32_t tci, ctci; uint16_t encap_proto; int proto_tree_index; ethertype_data_t ethertype_data; tvbuff_t *next_tvb = NULL; proto_tree *ieee8021ad_tree; proto_tree *ieee8021ad_tag_tree; /* set tree index */ proto_tree_index = proto_ieee8021ad; /* add info to column display */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "802.1ad"); col_clear(pinfo->cinfo, COL_INFO); tci = tvb_get_ntohs( tvb, 0 ); col_add_fstr(pinfo->cinfo, COL_INFO, "PRI: %d DROP: %d ID: %d", (tci >> 13), ((tci >> 12) & 1), (tci & 0xFFF)); /* create the protocol tree */ ptree = proto_tree_add_item(tree, proto_tree_index, tvb, 0, IEEE8021AD_LEN, ENC_NA); ieee8021ad_tree = proto_item_add_subtree(ptree, ett_ieee8021ad); encap_proto = tvb_get_ntohs(tvb, IEEE8021AD_LEN - 2); ethertype_data.fh_tree = ieee8021ad_tree; ethertype_data.trailer_id = hf_ieee8021ah_trailer; ethertype_data.fcs_len = 0; /* If it's a 1ah frame, create subtree for B-Tag, rename overall tree to 802.1ah, pass to 1ah dissector */ if (encap_proto == ETHERTYPE_IEEE_802_1AH) { if (tree) { tagtree = proto_tree_add_item(ptree, proto_tree_index, tvb, 0, 2, ENC_NA); ieee8021ad_tag_tree = proto_item_add_subtree(tagtree, ett_ieee8021ad); /* add fields */ proto_tree_add_uint(ieee8021ad_tag_tree, hf_ieee8021ad_priority, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ad_tag_tree, hf_ieee8021ad_cfi, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ad_tag_tree, hf_ieee8021ad_id, tvb, 0, 2, tci); /* set label of B-tag subtree */ proto_item_set_text(ieee8021ad_tag_tree, "B-Tag, B-VID: %d", tci & 0x0FFF); } next_tvb = tvb_new_subset_remaining(tvb, IEEE8021AD_LEN); if (ptree) { /* add bvid to label */ proto_item_set_text(ptree, "IEEE 802.1ah, B-VID: %d", tci & 0x0FFF); dissect_ieee8021ah_common(next_tvb, pinfo, ptree, tree, proto_tree_index); } else { dissect_ieee8021ah_common(next_tvb, pinfo, tree, NULL, proto_tree_index); } } else if (encap_proto == ETHERTYPE_IEEE_802_1AD) { /* two VLAN tags (i.e. Q-in-Q) */ ctci = tvb_get_ntohs(tvb, IEEE8021AD_LEN); if (tree) { /* add fields */ proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ad_priority, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ad_cfi, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ad_svid, tvb, 0, 2, tci); proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ad_priority, tvb, IEEE8021AD_LEN, 1, ctci); proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ad_cfi, tvb, IEEE8021AD_LEN, 1, ctci); proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ad_cvid, tvb, IEEE8021AD_LEN, 2, ctci); } proto_item_set_text(ptree, "IEEE 802.1ad, S-VID: %d, C-VID: %d", tci & 0x0FFF, ctci & 0x0FFF); ethertype_data.etype = tvb_get_ntohs(tvb, IEEE8021AD_LEN * 2 - 2); proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ah_etype, tvb, IEEE8021AD_LEN * 2 - 2, 2, ethertype_data.etype); ethertype_data.payload_offset = IEEE8021AD_LEN * 2; /* 802.1ad tags are always followed by an ethertype; call next dissector based on ethertype */ call_dissector_with_data(ethertype_handle, tvb, pinfo, tree, ðertype_data); } else { /* Something else (shouldn't really happen, but we'll support it anyways) */ if (tree) { /* add fields */ proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ad_priority, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ad_cfi, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ad_id, tvb, 0, 2, tci); } /* label should be 802.1ad not .1ah */ proto_item_set_text(ptree, "IEEE 802.1ad, ID: %d", tci & 0x0FFF); /* Add the Ethernet type to the protocol tree */ proto_tree_add_uint(ieee8021ad_tree, hf_ieee8021ah_etype, tvb, IEEE8021AD_LEN - 2, 2, encap_proto); ethertype_data.etype = encap_proto; ethertype_data.payload_offset = IEEE8021AD_LEN; /* 802.1ad tags are always followed by an ethertype; call next dissector based on ethertype */ call_dissector_with_data(ethertype_handle, tvb, pinfo, tree, ðertype_data); } return tvb_captured_length(tvb); } static void dissect_ieee8021ah_common(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, proto_tree *parent, int tree_index) { uint32_t tci; uint16_t encap_proto; proto_tree *ptree; ethertype_data_t ethertype_data; proto_tree *ieee8021ah_tag_tree; tci = tvb_get_ntohl( tvb, 0 ); col_add_fstr(pinfo->cinfo, COL_INFO, "PRI: %d Drop: %d NCA: %d Res1: %d Res2: %d I-SID: %d", (tci >> 29), ((tci >> 28) & 1), ((tci >> 27) & 1), ((tci >> 26) & 1), ((tci >> 24) & 3), tci & IEEE8021AH_ISIDMASK); /* create the protocol tree */ ptree = NULL; ieee8021ah_tag_tree = NULL; if (tree) { /* 802.1ah I-Tag */ ptree = proto_tree_add_item(tree, tree_index, tvb, 0, 4, ENC_NA); ieee8021ah_tag_tree = proto_item_add_subtree(ptree, ett_ieee8021ah); /* add fields */ proto_tree_add_uint(ieee8021ah_tag_tree, hf_ieee8021ah_priority, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ah_tag_tree, hf_ieee8021ah_drop, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ah_tag_tree, hf_ieee8021ah_nca, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ah_tag_tree, hf_ieee8021ah_res1, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ah_tag_tree, hf_ieee8021ah_res2, tvb, 0, 1, tci); proto_tree_add_uint(ieee8021ah_tag_tree, hf_ieee8021ah_isid, tvb, 1, 3, tci); proto_item_set_text(ieee8021ah_tag_tree, "I-Tag, I-SID: %d", tci & IEEE8021AH_ISIDMASK); proto_tree_add_item(tree, hf_ieee8021ah_c_daddr, tvb, 4, 6, ENC_NA); proto_tree_add_item(tree, hf_ieee8021ah_c_saddr, tvb, 10, 6, ENC_NA); /* add text to 802.1ad label */ if (parent) { proto_item_append_text(tree, ", I-SID: %d, C-Src: %s, C-Dst: %s", tci & IEEE8021AH_ISIDMASK, tvb_address_with_resolution_to_str(pinfo->pool, tvb, AT_ETHER, 10), tvb_address_with_resolution_to_str(pinfo->pool, tvb, AT_ETHER, 4)); } } encap_proto = tvb_get_ntohs(tvb, IEEE8021AH_LEN - 2); proto_tree_add_uint(tree, hf_ieee8021ah_etype, tvb, IEEE8021AD_LEN - 2, 2, encap_proto); /* 802.1ah I-tags are always followed by an ethertype; call next dissector based on ethertype */ /* If this was preceded by a 802.1ad tag, must pass original tree to next dissector, not 802.1ad tree */ ethertype_data.etype = encap_proto; ethertype_data.fh_tree = tree; ethertype_data.payload_offset = IEEE8021AH_LEN; ethertype_data.trailer_id = hf_ieee8021ah_trailer; ethertype_data.fcs_len = 0; if (parent) { call_dissector_with_data(ethertype_handle, tvb, pinfo, parent, ðertype_data); } else { call_dissector_with_data(ethertype_handle, tvb, pinfo, tree, ðertype_data); } } static int dissect_ieee8021ah(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { proto_item *pi; uint32_t tci; int proto_tree_index; proto_tree *ieee8021ah_tree; /* set tree index */ proto_tree_index = proto_ieee8021ah; /* add info to column display */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "802.1ah"); col_clear(pinfo->cinfo, COL_INFO); tci = tvb_get_ntohl( tvb, 0 ); col_add_fstr(pinfo->cinfo, COL_INFO, "PRI: %d Drop: %d NCA: %d Res1: %d Res2: %d I-SID: %d", (tci >> 29), ((tci >> 28) & 1), ((tci >> 27) & 1), ((tci >> 26) & 1), ((tci >> 24) & 3), (tci & 0x00FFFFFF)); pi = proto_tree_add_item(tree, proto_tree_index, tvb, 0, IEEE8021AH_LEN, ENC_NA); ieee8021ah_tree = proto_item_add_subtree(pi, ett_ieee8021ah); if (ieee8021ah_tree) { dissect_ieee8021ah_common(tvb, pinfo, ieee8021ah_tree, tree, proto_tree_index); } else { dissect_ieee8021ah_common(tvb, pinfo, tree, NULL, proto_tree_index); } return tvb_captured_length(tvb); } /* Protocol Registration **************************************************/ void proto_register_ieee8021ah(void) { static hf_register_info hf[] = { { &hf_ieee8021ah_priority, { "Priority", "ieee8021ah.priority", FT_UINT32, BASE_DEC, 0, 0xE0000000, NULL, HFILL }}, { &hf_ieee8021ah_drop, { "DROP", "ieee8021ah.drop", FT_UINT32, BASE_DEC, 0, 0x10000000, NULL, HFILL }}, { &hf_ieee8021ah_nca, { "NCA", "ieee8021ah.nca", FT_UINT32, BASE_DEC, 0, 0x08000000, "No Customer Addresses", HFILL }}, { &hf_ieee8021ah_res1, { "RES1", "ieee8021ah.res1", FT_UINT32, BASE_DEC, 0, 0x04000000, "Reserved1", HFILL }}, { &hf_ieee8021ah_res2, { "RES2", "ieee8021ah.res2", FT_UINT32, BASE_DEC, 0, 0x03000000, "Reserved2", HFILL }}, { &hf_ieee8021ah_isid, { "I-SID", "ieee8021ah.isid", FT_UINT32, BASE_DEC, 0, 0x00FFFFFF, NULL, HFILL }}, { &hf_ieee8021ah_c_daddr, { "C-Destination", "ieee8021ah.cdst", FT_ETHER, BASE_NONE, NULL, 0x0, "Customer Destination Address", HFILL }}, { &hf_ieee8021ah_c_saddr, { "C-Source", "ieee8021ah.csrc", FT_ETHER, BASE_NONE, NULL, 0x0, "Customer Source Address", HFILL }}, { &hf_ieee8021ah_etype, { "Type", "ieee8021ah.etype", FT_UINT16, BASE_HEX, VALS(etype_vals), 0x0, NULL, HFILL }}, #if 0 { &hf_ieee8021ah_len, { "Length", "ieee8021ah.len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }}, #endif { &hf_ieee8021ah_trailer, { "Trailer", "ieee8021ah.trailer", FT_BYTES, BASE_NONE, NULL, 0x0, "802.1ah Trailer", HFILL }} }; static hf_register_info hf_1ad[] = { { &hf_ieee8021ad_priority, { "Priority", "ieee8021ad.priority", FT_UINT16, BASE_DEC, 0, 0xE000, NULL, HFILL }}, { &hf_ieee8021ad_cfi, { "DEI", "ieee8021ad.dei", FT_UINT16, BASE_DEC, 0, 0x1000, "Drop Eligibility", HFILL }}, { &hf_ieee8021ad_id, { "ID", "ieee8021ad.id", FT_UINT16, BASE_DEC, 0, 0x0FFF, "Vlan ID", HFILL }}, { &hf_ieee8021ad_svid, { "ID", "ieee8021ad.svid", FT_UINT16, BASE_DEC, 0, 0x0FFF, "S-Vlan ID", HFILL }}, { &hf_ieee8021ad_cvid, { "ID", "ieee8021ad.cvid", FT_UINT16, BASE_DEC, 0, 0x0FFF, "C-Vlan ID", HFILL }}, }; static int *ett[] = { &ett_ieee8021ah, &ett_ieee8021ad }; module_t *ieee8021ah_module; /* registration */ /* dot1ah */ proto_ieee8021ah = proto_register_protocol("IEEE 802.1ah", "IEEE 802.1AH", "ieee8021ah"); ieee8021ah_handle = register_dissector("ieee8021ah", dissect_ieee8021ah, proto_ieee8021ah); proto_register_field_array(proto_ieee8021ah, hf, array_length(hf)); proto_ieee8021ad = proto_register_protocol("IEEE 802.1ad", "IEEE 802.1AD", "ieee8021ad"); ieee8021ad_handle = register_dissector("ieee8021ad", dissect_ieee8021ad, proto_ieee8021ad); proto_register_field_array(proto_ieee8021ad, hf_1ad, array_length(hf_1ad)); /* register subtree array for both */ proto_register_subtree_array(ett, array_length(ett)); /* add a user preference to set the 802.1ah ethertype */ ieee8021ah_module = prefs_register_protocol(proto_ieee8021ah, proto_reg_handoff_ieee8021ah); prefs_register_uint_preference(ieee8021ah_module, "8021ah_ethertype", "802.1ah Ethertype (in hex)", "(Hexadecimal) Ethertype used to indicate IEEE 802.1ah tag.", 16, &ieee8021ah_ethertype); } void proto_reg_handoff_ieee8021ah(void) { static bool prefs_initialized = false; static unsigned int old_ieee8021ah_ethertype; static capture_dissector_handle_t ieee8021ah_cap_handle; if (!prefs_initialized){ dissector_add_uint("ethertype", ETHERTYPE_IEEE_802_1AD, ieee8021ad_handle); ethertype_handle = find_dissector_add_dependency("ethertype", proto_ieee8021ah); find_dissector_add_dependency("ethertype", proto_ieee8021ad); ieee8021ah_cap_handle = create_capture_dissector_handle(capture_ieee8021ah, proto_ieee8021ah); capture_dissector_add_uint("ethertype", ETHERTYPE_IEEE_802_1AD, ieee8021ah_cap_handle); capture_dissector_add_uint("ethertype", ETHERTYPE_IEEE_802_1AH, ieee8021ah_cap_handle); ipx_cap_handle = find_capture_dissector("ipx"); llc_cap_handle = find_capture_dissector("llc"); prefs_initialized = true; } else { dissector_delete_uint("ethertype", old_ieee8021ah_ethertype, ieee8021ah_handle); } old_ieee8021ah_ethertype = ieee8021ah_ethertype; dissector_add_uint("ethertype", ieee8021ah_ethertype, ieee8021ah_handle); } /* * Editor modelines - https://www.wireshark.org/tools/modelines.html * * Local variables: * c-basic-offset: 4 * tab-width: 8 * indent-tabs-mode: nil * End: * * vi: set shiftwidth=4 tabstop=8 expandtab: * :indentSize=4:tabSize=8:noTabs=true: */