/* packet-mrp_mmrp.c * Routines for MMRP (MRP Multiple Mac Registration Protocol) dissection * Copyright 2011, Johannes Jochen * * * Based on the code from packet-mrp-msrp.c (MSRP) from * Torrey Atcitty and Craig Gunther * Copyright 2010 * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later * * The MMRP Protocol specification can be found at the following: * http://standards.ieee.org/about/get/802/802.1.html * */ #include "config.h" #include #include void proto_register_mrp_mmrp(void); void proto_reg_handoff_mrp_mmrp(void); static dissector_handle_t mmrp_handle; /* MMRP End Mark Sequence */ #define MMRP_END_MARK 0x0000 /**********************************************************/ /* Offsets of fields within an MMRP packet */ /**********************************************************/ #define MMRP_PROTOCOL_VERSION_OFFSET 0 /* Next comes the MMRP Message group */ #define MMRP_MESSAGE_GROUP_OFFSET (MMRP_PROTOCOL_VERSION_OFFSET + 1) /* Message is a group of fields */ #define MMRP_ATTRIBUTE_TYPE_OFFSET (MMRP_MESSAGE_GROUP_OFFSET) #define MMRP_ATTRIBUTE_LENGTH_OFFSET (MMRP_ATTRIBUTE_TYPE_OFFSET + 1) /* Next comes the MMRP AttributeList group */ #define MMRP_ATTRIBUTE_LIST_GROUP_OFFSET (MMRP_ATTRIBUTE_LENGTH_OFFSET + 1) /* AttributeList is a group of fields */ /* Next comes the MMRP VectorAttribute group */ #define MMRP_VECTOR_ATTRIBUTE_GROUP_OFFSET (MMRP_ATTRIBUTE_LIST_GROUP_OFFSET) /* VectorAttribute is a group of fields */ #define MMRP_VECTOR_HEADER_OFFSET (MMRP_VECTOR_ATTRIBUTE_GROUP_OFFSET) /* contains the following two fields */ #define MMRP_LEAVE_ALL_EVENT_OFFSET (MMRP_VECTOR_HEADER_OFFSET) #define MMRP_LEAVE_ALL_EVENT_MASK 0xE000 #define MMRP_NUMBER_OF_VALUES_OFFSET (MMRP_VECTOR_HEADER_OFFSET) #define MMRP_NUMBER_OF_VALUES_MASK 0x1fff /* Next comes the MMRP FirstValue group */ #define MMRP_FIRST_VALUE_GROUP_OFFSET (MMRP_VECTOR_HEADER_OFFSET + 2) /* FirstValue is a group of fields */ #define MMRP_SERVICE_THREE_PACKED_OFFSET (MMRP_FIRST_VALUE_GROUP_OFFSET + 1) #define MMRP_MAC_THREE_PACKED_OFFSET (MMRP_FIRST_VALUE_GROUP_OFFSET + 6) /**********************************************************/ /* Valid field contents */ /**********************************************************/ /* Attribute Type definitions */ #define MMRP_ATTRIBUTE_TYPE_SERVICE 0x01 #define MMRP_ATTRIBUTE_TYPE_MAC 0x02 static const value_string attribute_type_vals[] = { { MMRP_ATTRIBUTE_TYPE_SERVICE, "Service Requirement" }, { MMRP_ATTRIBUTE_TYPE_MAC, "MAC" }, { 0, NULL } }; /* Leave All Event definitions */ #define MMRP_NULLLEAVEALL 0 #define MMRP_LEAVEALL 1 static const value_string leave_all_vals[] = { { MMRP_NULLLEAVEALL, "Null" }, { MMRP_LEAVEALL, "Leave All" }, { 0, NULL } }; /* Three Packed Event definitions */ static const value_string three_packed_vals[] = { { 0, "New" }, { 1, "JoinIn" }, { 2, "In" }, { 3, "JoinMt" }, { 4, "Mt" }, { 5, "Lv" }, { 0, NULL } }; /**********************************************************/ /* Initialize the protocol and registered fields */ /**********************************************************/ static int proto_mmrp; static int hf_mmrp_proto_id; static int hf_mmrp_message; /* Message is a group of fields */ static int hf_mmrp_attribute_type; static int hf_mmrp_attribute_length; static int hf_mmrp_attribute_list; /* AttributeList is a group of fields */ static int hf_mmrp_vector_attribute; /* VectorAttribute is a group of fields */ /* The following VectorHeader contains the LeaveAllEvent and NumberOfValues */ static int hf_mmrp_vector_header; static int hf_mmrp_leave_all_event; static int hf_mmrp_number_of_values; static int ett_vector_header; static int * const vector_header_fields[] = { &hf_mmrp_leave_all_event, &hf_mmrp_number_of_values, NULL }; static int hf_mmrp_first_value; /* FirstValue is a group of fields */ static int hf_mmrp_mac; static int hf_mmrp_ser_req; static int hf_mmrp_three_packed_event; static int hf_mmrp_end_mark; /* Initialize the subtree pointers */ static int ett_mmrp; static int ett_msg; static int ett_attr_list; static int ett_vect_attr; static int ett_first_value; /**********************************************************/ /* Dissector starts here */ /**********************************************************/ /* dissect_mmrp_common1 (called from dissect_mmrp) * * dissect the following fields which are common to all MMRP attributes: * Attribute Type * Attribute Length * Attribute List Length */ static void dissect_mmrp_common1(proto_tree *msg_tree, tvbuff_t *tvb, int msg_offset) { proto_tree_add_item(msg_tree, hf_mmrp_attribute_type, tvb, MMRP_ATTRIBUTE_TYPE_OFFSET + msg_offset, 1, ENC_BIG_ENDIAN); proto_tree_add_item(msg_tree, hf_mmrp_attribute_length, tvb, MMRP_ATTRIBUTE_LENGTH_OFFSET + msg_offset, 1, ENC_BIG_ENDIAN); } /* dissect_mmrp_common2 (called from dissect_mmrp) * * dissect the following fields which are common to all MMRP attributes: * Leave All Event * Number of Values fields */ static void dissect_mmrp_common2(proto_tree *vect_attr_tree, tvbuff_t *tvb, int msg_offset) { proto_tree_add_bitmask(vect_attr_tree, tvb, MMRP_VECTOR_HEADER_OFFSET + msg_offset, hf_mmrp_vector_header, ett_vector_header, vector_header_fields, ENC_BIG_ENDIAN); } /* dissect_mmrp_three_packed_event (called from dissect_mmrp) * * dissect one or more ThreePackedEvents */ static unsigned dissect_mmrp_three_packed_event(proto_tree *vect_attr_tree, tvbuff_t *tvb, unsigned offset, uint16_t number_of_values) { unsigned counter; for ( counter = 0; counter < number_of_values; ) { uint8_t value; uint8_t three_packed_event[3]; value = tvb_get_uint8(tvb, offset); three_packed_event[0] = value / 36; value -= 36 * three_packed_event[0]; three_packed_event[1] = value / 6; value -= 6 * three_packed_event[1]; three_packed_event[2] = value; proto_tree_add_uint(vect_attr_tree, hf_mmrp_three_packed_event, tvb, offset, sizeof(uint8_t), three_packed_event[0]); counter++; if ( counter < number_of_values ) { proto_tree_add_uint(vect_attr_tree, hf_mmrp_three_packed_event, tvb, offset, sizeof(uint8_t), three_packed_event[1]); counter++; } if ( counter < number_of_values ) { proto_tree_add_uint(vect_attr_tree, hf_mmrp_three_packed_event, tvb, offset, sizeof(uint8_t), three_packed_event[2]); counter++; } offset++; } return offset; } /* dissect_main * * main dissect function that calls the other functions listed above as necessary */ static int dissect_mmrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_) { /* Set up structures needed to add the protocol subtrees and manage them */ proto_item *ti, *msg_ti, *attr_list_ti, *vect_attr_ti, *first_value_ti; proto_tree *mmrp_tree, *msg_tree, *attr_list_tree, *vect_attr_tree, *first_value_tree; /* Make entries in Protocol column and Info column on summary display */ col_set_str(pinfo->cinfo, COL_PROTOCOL, "MRP-MMRP"); col_set_str(pinfo->cinfo, COL_INFO, "Multiple Mac Registration Protocol"); if (tree) { uint8_t attribute_type; uint8_t attribute_length; uint16_t number_of_values; unsigned offset = 0; int vect_attr_len; int msg_offset; /* Use when handling multiple messages. This points to current msg being decoded. */ int vect_offset; /* Use when handling multiple vector attributes. This points to the current vector attribute being decoded. */ ti = proto_tree_add_item(tree, proto_mmrp, tvb, 0, -1, ENC_NA); mmrp_tree = proto_item_add_subtree(ti, ett_mmrp); proto_tree_add_item(mmrp_tree, hf_mmrp_proto_id, tvb, MMRP_PROTOCOL_VERSION_OFFSET, 1, ENC_BIG_ENDIAN); /* MMRP supports multiple MRP Messages per frame. Handle those Messages in * the following while() loop. You will know you are at the end of the list * of messages when the EndMark (0x0000) is encountered instead of an * Attribute Type and Attribute Length (guaranteed to not be 0x0000). */ msg_offset = 0; while (tvb_get_ntohs(tvb, MMRP_ATTRIBUTE_TYPE_OFFSET + msg_offset) != MMRP_END_MARK) { attribute_type = tvb_get_uint8(tvb, MMRP_ATTRIBUTE_TYPE_OFFSET + msg_offset); attribute_length = tvb_get_uint8(tvb, MMRP_ATTRIBUTE_LENGTH_OFFSET + msg_offset); /* MMRP Message is a group of fields * * Contains AttributeType (1 byte) * + AttributeLength (1 byte) * + AttributeList (AttributeListLength bytes) * bytes of data */ msg_ti = proto_tree_add_item(mmrp_tree, hf_mmrp_message, tvb, MMRP_MESSAGE_GROUP_OFFSET + msg_offset, -1, ENC_NA); msg_tree = proto_item_add_subtree(msg_ti, ett_msg); /* Append AttributeType description to the end of the "Message" heading */ proto_item_append_text(msg_tree, ": %s (%d)", val_to_str_const(attribute_type, attribute_type_vals, ""), attribute_type); dissect_mmrp_common1(msg_tree, tvb, msg_offset); /* MMRP AttributeList is a group of fields * * Contains AttributeListLength bytes of data NOT */ attr_list_ti = proto_tree_add_item(msg_tree, hf_mmrp_attribute_list, tvb, MMRP_ATTRIBUTE_LIST_GROUP_OFFSET + msg_offset, -1, ENC_NA); attr_list_tree = proto_item_add_subtree(attr_list_ti, ett_attr_list); /* MMRP supports multiple MRP Vector Attributes per Attribute List. Handle those * Vector Attributes in the following while() loop. You will know you are at the * end of the list of Vector Attributes when the EndMark (0x0000) is encountered * instead of a Vector Header (guaranteed to not be 0x0000). */ vect_offset = 0; while (tvb_get_ntohs(tvb, MMRP_VECTOR_HEADER_OFFSET + msg_offset + vect_offset) != MMRP_END_MARK) { /* MMRP VectorAttribute is a group of fields * * Contains VectorHeader (2 bytes) * + FirstValue (AttributeLength bytes) * + VectorThreePacked (NumberOfValues @ 3/vector bytes) * + VectorFourPacked (NumberOfValues @ 4/vector bytes only for Listener attributes) * bytes of data */ number_of_values = tvb_get_ntohs(tvb, MMRP_NUMBER_OF_VALUES_OFFSET + msg_offset + vect_offset) & MMRP_NUMBER_OF_VALUES_MASK; vect_attr_len = 2 + attribute_length + (number_of_values + 2)/3; /* stores 3 values per byte */ vect_attr_ti = proto_tree_add_item(attr_list_tree, hf_mmrp_vector_attribute, tvb, MMRP_VECTOR_ATTRIBUTE_GROUP_OFFSET + msg_offset + vect_offset, vect_attr_len, ENC_NA); vect_attr_tree = proto_item_add_subtree(vect_attr_ti, ett_vect_attr); dissect_mmrp_common2(vect_attr_tree, tvb, msg_offset + vect_offset); if (attribute_type == MMRP_ATTRIBUTE_TYPE_MAC) { /* MMRP FirstValue is a Mac Address*/ first_value_ti = proto_tree_add_item(vect_attr_tree, hf_mmrp_first_value, tvb, MMRP_FIRST_VALUE_GROUP_OFFSET + msg_offset + vect_offset, attribute_length, ENC_NA); first_value_tree = proto_item_add_subtree(first_value_ti, ett_first_value); /* Add MAC components to First Value tree */ proto_tree_add_item(first_value_tree, hf_mmrp_mac, tvb, MMRP_FIRST_VALUE_GROUP_OFFSET + msg_offset + vect_offset, 6, ENC_NA); /* Decode three packed events. */ offset = dissect_mmrp_three_packed_event(vect_attr_tree, tvb, MMRP_MAC_THREE_PACKED_OFFSET + msg_offset + vect_offset, number_of_values); } else if (attribute_type == MMRP_ATTRIBUTE_TYPE_SERVICE) { /* MMRP Service Requirement*/ first_value_ti = proto_tree_add_item(vect_attr_tree, hf_mmrp_first_value, tvb, MMRP_FIRST_VALUE_GROUP_OFFSET + msg_offset + vect_offset, attribute_length, ENC_NA); first_value_tree = proto_item_add_subtree(first_value_ti, ett_first_value); /* Add ServiceRequirement components to First Value tree */ proto_tree_add_item(first_value_tree, hf_mmrp_ser_req, tvb, MMRP_FIRST_VALUE_GROUP_OFFSET + msg_offset + vect_offset, 1, ENC_BIG_ENDIAN); offset = dissect_mmrp_three_packed_event(vect_attr_tree, tvb, MMRP_SERVICE_THREE_PACKED_OFFSET + msg_offset + vect_offset, number_of_values); } vect_offset += vect_attr_len; /* Move to next Vector Attribute, if there is one */ } /* Multiple VectorAttribute while() */ proto_tree_add_item(attr_list_tree, hf_mmrp_end_mark, tvb, offset, 2, ENC_BIG_ENDIAN); /* VectorAttribute EndMark */ msg_offset += vect_offset + 2/* + VectorHeader */ + 2/* + endmark */; } /* Multiple Message while() */ proto_tree_add_item(mmrp_tree, hf_mmrp_end_mark, tvb, offset+2, 2, ENC_BIG_ENDIAN); /* Message EndMark */ } return tvb_captured_length(tvb); } /* Register the protocol with Wireshark */ void proto_register_mrp_mmrp(void) { static hf_register_info hf[] = { { &hf_mmrp_proto_id, { "Protocol Version", "mrp-mmrp.protocol_version", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_mmrp_message, /* Message is a group of fields */ { "Message", "mrp-mmrp.message", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_mmrp_attribute_type, { "Attribute Type", "mrp-mmrp.attribute_type", FT_UINT8, BASE_DEC, VALS(attribute_type_vals), 0x0, NULL, HFILL } }, { &hf_mmrp_attribute_length, { "Attribute Length", "mrp-mmrp.attribute_length", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_mmrp_attribute_list, /* AttributeList is a group of fields */ { "Attribute List", "mrp-mmrp.attribute_list", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_mmrp_vector_attribute, /* VectorAttribute is a group of fields */ { "Vector Attribute", "mrp-mmrp.vector_attribute", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_mmrp_vector_header, { "Vector Header", "mrp-mmrp.vector_header", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_mmrp_leave_all_event, { "Leave All Event", "mrp-mmrp.leave_all_event", FT_UINT16, BASE_DEC, VALS(leave_all_vals), MMRP_LEAVE_ALL_EVENT_MASK, NULL, HFILL } }, { &hf_mmrp_number_of_values, { "Number of Values", "mrp-mmrp.number_of_values", FT_UINT16, BASE_DEC, NULL, MMRP_NUMBER_OF_VALUES_MASK, NULL, HFILL } }, { &hf_mmrp_first_value, /* FirstValue is a group of fields */ { "First Value", "mrp-mmrp.first_value", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_mmrp_mac, { "MAC", "mrp-mmrp.mac", FT_ETHER, BASE_NONE, NULL, 0x00, NULL, HFILL } }, { &hf_mmrp_ser_req, { "Service Requirement", "mrp-mmrp.service_requirement", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_mmrp_three_packed_event, { "Attribute Event", "mrp-mmrp.three_packed_event", FT_UINT8, BASE_DEC, VALS(three_packed_vals), 0x0, NULL, HFILL } }, { &hf_mmrp_end_mark, { "End Mark", "mrp-mmrp.end_mark", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL } }, }; /* Setup protocol subtree array */ static int *ett[] = { &ett_mmrp, &ett_msg, &ett_attr_list, &ett_vect_attr, &ett_vector_header, &ett_first_value }; /* Register the protocol name and description */ proto_mmrp = proto_register_protocol("Multiple Mac Registration Protocol", "MRP-MMRP", "mrp-mmrp"); /* Required function calls to register the header fields and subtrees used */ proto_register_field_array(proto_mmrp, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); /* Register the dissector */ mmrp_handle = register_dissector("mrp-mmrp", dissect_mmrp, proto_mmrp); } void proto_reg_handoff_mrp_mmrp(void) { dissector_add_uint("ethertype", ETHERTYPE_MMRP, mmrp_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: */