/* packet-stt.c * * Routines for Stateless Transport Tunneling (STT) packet dissection * Remi Vichery * * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * * Protocol ref: * http://tools.ietf.org/html/draft-davie-stt-06 */ #include "config.h" #include #include /* IANA ref: * http://www.iana.org/assignments/service-names-port-numbers/service- * names-port-numbers.xml */ #define TCP_PORT_STT 7471 #define STT_PCP_MASK 0xE000 #define STT_V_MASK 0x1000 #define STT_VLANID_MASK 0x0FFF #define NO_MASK 0x0000 #define FLAG_B0_MASK 0x0001 #define FLAG_B1_MASK 0x0002 #define FLAG_B2_MASK 0x0004 #define FLAG_B3_MASK 0x0008 #define FLAG_B4_MASK 0x0010 #define FLAG_B5_MASK 0x0020 #define FLAG_B6_MASK 0x0040 #define FLAG_B7_MASK 0x0080 void proto_register_stt(void); void proto_reg_handoff_stt(void); static int proto_stt = -1; static int hf_stt_version = -1; static int hf_stt_flags = -1; static int hf_stt_flag_b7 = -1; static int hf_stt_flag_b6 = -1; static int hf_stt_flag_b5 = -1; static int hf_stt_flag_b4 = -1; static int hf_stt_flag_b3 = -1; static int hf_stt_flag_b2 = -1; static int hf_stt_flag_b1 = -1; static int hf_stt_flag_b0 = -1; static int hf_stt_l4_offset = -1; static int hf_stt_reserved_8 = -1; static int hf_stt_mss = -1; static int hf_stt_pcp = -1; static int hf_stt_v = -1; static int hf_stt_vlan_id= -1; static int hf_stt_context_id = -1; static int hf_stt_padding = -1; static int ett_stt = -1; static int ett_stt_flgs = -1; static expert_field ei_stt_l4_offset = EI_INIT; static dissector_handle_t eth_handle; /* From Table G-2 of IEEE standard 802.1Q-2005 */ static const value_string pri_vals[] = { { 1, "Background" }, { 0, "Best Effort (default)" }, { 2, "Excellent Effort" }, { 3, "Critical Applications" }, { 4, "Video, < 100ms latency and jitter" }, { 5, "Voice, < 10ms latency and jitter" }, { 6, "Internetwork Control" }, { 7, "Network Control" }, { 0, NULL } }; static void dissect_stt(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_tree *stt_tree, *flg_tree; proto_item *ti, *flg_item, *l4_offset_item; tvbuff_t *next_tvb; guint8 flags, l4_offset; guint16 attributes; guint64 context_id; int offset = 0; /* Make entry in Protocol column on summary display. */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "STT"); /* Clean previous TCP information because STT frames are encapsulated in a TCP-like header (to avoid DUP Ack, TCP Out-of-order, ...). */ col_clear_fence(pinfo->cinfo, COL_INFO); ti = proto_tree_add_item(tree, proto_stt, tvb, offset, -1, ENC_NA); stt_tree = proto_item_add_subtree(ti, ett_stt); /* 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Version | Flags | L4 Offset | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Max. Segment Size | PCP |V| VLAN ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + Context ID (64 bits) + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Padding | Data | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | */ /* Protocol version */ proto_tree_add_item(stt_tree, hf_stt_version, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; /* Flags tree */ flg_item = proto_tree_add_item(stt_tree, hf_stt_flags, tvb, offset, 1, ENC_BIG_ENDIAN); flg_tree = proto_item_add_subtree(flg_item, ett_stt_flgs); /* Flags */ flags = tvb_get_guint8(tvb, offset); proto_tree_add_item(flg_tree, hf_stt_flag_b7, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(flg_tree, hf_stt_flag_b6, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(flg_tree, hf_stt_flag_b5, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(flg_tree, hf_stt_flag_b4, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(flg_tree, hf_stt_flag_b3, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(flg_tree, hf_stt_flag_b2, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(flg_tree, hf_stt_flag_b1, tvb, offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(flg_tree, hf_stt_flag_b0, tvb, offset, 1, ENC_BIG_ENDIAN); offset++; /* Layer 4 offset */ l4_offset = tvb_get_guint8(tvb, offset); l4_offset_item = proto_tree_add_item(stt_tree, hf_stt_l4_offset, tvb, offset, 1, ENC_BIG_ENDIAN); /* Display an error if offset is != 0 when encapsulated packet is NOT TCP */ if ( !(flags & FLAG_B3_MASK) && (l4_offset != 0) ) { expert_add_info_format(pinfo, l4_offset_item, &ei_stt_l4_offset, "Incorrect offset, should be equals to zero"); } /* Display an error if offset equals 0 when encapsulated packet is TCP */ if ( (flags & FLAG_B3_MASK) && (l4_offset == 0) ) { expert_add_info_format(pinfo, l4_offset_item, &ei_stt_l4_offset, "Incorrect offset, should be greater than zero"); } offset ++; /* Reserved field (1 byte). MUST be 0 on transmission, ignored on receipt. */ proto_tree_add_item(stt_tree, hf_stt_reserved_8, tvb, offset, 1, ENC_BIG_ENDIAN); offset ++; /* Maximum Segment Size. MUST be 0 if segmentation offload is not in use. */ proto_tree_add_item(stt_tree, hf_stt_mss, tvb, offset, 2, ENC_BIG_ENDIAN); offset += 2; /* Tag Control Information like header */ attributes = tvb_get_ntohs(tvb, offset); /* if V flag is set, it indicates the presence of a valid VLAN ID in the following field and valid PCP in the preceding field. */ if (attributes & STT_V_MASK) { /* Display priority code point and VLAN ID when V flag is set */ proto_item_append_text(ti, ", Priority: %u, VLAN ID: %u", (attributes >> 13), (attributes & STT_VLANID_MASK)); proto_tree_add_item(stt_tree, hf_stt_pcp, tvb, offset, 2, ENC_BIG_ENDIAN); proto_tree_add_item(stt_tree, hf_stt_v, tvb, offset, 2, ENC_BIG_ENDIAN); proto_tree_add_item(stt_tree, hf_stt_vlan_id, tvb, offset, 2, ENC_BIG_ENDIAN); } offset += 2; /* Context ID */ context_id = tvb_get_ntoh64(tvb, offset); proto_tree_add_item(stt_tree, hf_stt_context_id, tvb, offset, 8, ENC_BIG_ENDIAN); proto_item_append_text(ti, ", Context ID: 0x%" G_GINT64_MODIFIER "x",context_id); offset += 8; /* Padding */ proto_tree_add_item(stt_tree, hf_stt_padding, tvb, offset, 2, ENC_NA); offset += 2; next_tvb = tvb_new_subset_remaining(tvb, offset); call_dissector(eth_handle, next_tvb, pinfo, tree); } /* Register STT with Wireshark */ void proto_register_stt(void) { expert_module_t* expert_stt; static hf_register_info hf[] = { { &hf_stt_version, { "Version", "stt.version", FT_UINT8, BASE_DEC, NULL, NO_MASK, NULL, HFILL }, }, { &hf_stt_flags, { "Flags", "stt.flags", FT_UINT8, BASE_HEX, NULL, NO_MASK, NULL, HFILL, }, }, { &hf_stt_flag_b7, { "Unused flag", "stt.flags.b7", FT_BOOLEAN, 8, NULL, FLAG_B7_MASK, NULL, HFILL, }, }, { &hf_stt_flag_b6, { "Unused flag", "stt.flags.b6", FT_BOOLEAN, 8, NULL, FLAG_B6_MASK, NULL, HFILL, }, }, { &hf_stt_flag_b5, { "Unused flag", "stt.flags.b5", FT_BOOLEAN, 8, NULL, FLAG_B5_MASK, NULL, HFILL, }, }, { &hf_stt_flag_b4, { "Unused flag", "stt.flags.b4", FT_BOOLEAN, 8, NULL, FLAG_B4_MASK, NULL, HFILL, }, }, { &hf_stt_flag_b3, { "TCP payload", "stt.flags.b3", FT_BOOLEAN, 8, NULL, FLAG_B3_MASK, NULL, HFILL, }, }, { &hf_stt_flag_b2, { "IPv4 packet", "stt.flags.b2", FT_BOOLEAN, 8, NULL, FLAG_B2_MASK, NULL, HFILL, }, }, { &hf_stt_flag_b1, { "Checksum partial", "stt.flags.b1", FT_BOOLEAN, 8, NULL, FLAG_B1_MASK, NULL, HFILL, }, }, { &hf_stt_flag_b0, { "Checksum verified", "stt.flags.b0", FT_BOOLEAN, 8, NULL, FLAG_B0_MASK, NULL, HFILL, }, }, { &hf_stt_l4_offset, { "L4 Offset", "stt.l4offset", FT_UINT8, BASE_DEC, NULL, NO_MASK, NULL, HFILL, }, }, { &hf_stt_reserved_8, { "Reserved", "stt.reserved", FT_UINT8, BASE_DEC, NULL, NO_MASK, NULL, HFILL, }, }, { &hf_stt_mss, { "Max Segment Size", "stt.mss", FT_UINT16, BASE_DEC, NULL, NO_MASK, NULL, HFILL, }, }, { &hf_stt_pcp, { "PCP", "stt.pcp", FT_UINT16, BASE_DEC, VALS(pri_vals), STT_PCP_MASK, NULL, HFILL, }, }, { &hf_stt_v, { "V flag", "stt.v", FT_UINT16, BASE_DEC, NULL, STT_V_MASK, NULL, HFILL, }, }, { &hf_stt_vlan_id, { "VLAN ID", "stt.vlan_id", FT_UINT16, BASE_DEC, NULL, STT_VLANID_MASK, NULL, HFILL, }, }, { &hf_stt_context_id, { "Context ID", "stt.context_id", FT_UINT64, BASE_HEX, NULL, NO_MASK, NULL, HFILL, }, }, { &hf_stt_padding, { "Padding", "stt.padding", FT_BYTES, BASE_NONE, NULL, NO_MASK, NULL, HFILL, }, }, }; /* Setup protocol subtree array */ static gint *ett[] = { &ett_stt, &ett_stt_flgs, }; static ei_register_info ei[] = { { &ei_stt_l4_offset, { "stt.l4_offset_bad.expert", PI_PROTOCOL, PI_WARN, "Bad L4 Offset", EXPFILL } }, }; /* Register the protocol name and description */ proto_stt = proto_register_protocol("Stateless Transport Tunneling", "STT", "stt"); expert_stt = expert_register_protocol(proto_stt); expert_register_field_array(expert_stt, ei, array_length(ei)); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_stt, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); } void proto_reg_handoff_stt(void) { dissector_handle_t stt_handle; eth_handle = find_dissector("eth"); /* Need to be modified with a special hack in the TCP dissector. */ stt_handle = create_dissector_handle(dissect_stt, proto_stt); dissector_add_uint("tcp.port", TCP_PORT_STT, stt_handle); } /* * Editor modelines - http://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: */