/* packet-nordic_ble.c * Routines for nRF Sniffer for Bluetooth LE dissection * * Copyright (c) 2016-2018 Nordic Semiconductor. * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1998 Gerald Combs * * SPDX-License-Identifier: GPL-2.0-or-later */ /* nRF Sniffer for Bluetooth LE packet format: BoardID + Header + Payload * * +--------+--------+--------+--------+--------+--------+--------+--------+ * | BoardID (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * * Header version 0 (legacy): * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Packet ID (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Packet counter (LSB) | * | (2 bytes) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Unused | * | (2 bytes) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Length of payload (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * * Header version 1: * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Length of header (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Length of payload (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Protocol version (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Packet counter (LSB) | * | (2 bytes) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Packet ID (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * * Header version > 1: * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Length of payload (little endian) | * | (2 bytes) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Protocol version (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Packet counter (little endian) | * | (2 bytes) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Packet ID (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * * Packet ID: * 0x00 = REQ_FOLLOW * Host tells the Sniffer to scan for Advertising from a specific * address and follow all communication it has with other devices. * * 0x01 = EVENT_FOLLOW * Sniffer tells the Host that it has entered the FOLLOW state. * * 0x02 = EVENT_PACKET_ADVERTISING * Sniffer tells the Host that it has received an advertising physical * channel PDU. * * 0x05 = EVENT_CONNECT * Sniffer tells the Host that someone has connected to the unit we * are following. * * 0x06 = EVENT_PACKET_DATA * Protocol version < 3: * Sniffer tells the host that it has received a packet on any physical * channel. * Access address == 0x8e89bed6 Advertising physical channel PDU * Access address != 0x8e89bed6 Data physical channel PDU * Protocol version 3: * Sniffer tells the Host that it has received a data physical * channel PDU. * * 0x07 = REQ_SCAN_CONT * Host tells the Sniffer to scan continuously for any advertising * physical channel PDUs and send all packets received. * * 0x09 = EVENT_DISCONNECT * Sniffer tells the Host that the connected address we were following * has received a disconnect packet. * * 0x0C = SET_TEMPORARY_KEY * Specify a temporary key (TK) to use on encryption. * Only used for Legacy OOB and Legacy passkey pairing. * * 0x0D = PING_REQ * * 0x0E = PING_RESP * * 0x13 = SWITCH_BAUD_RATE_REQ * * 0x14 = SWITCH_BAUD_RATE_RESP * * 0x17 = SET_ADV_CHANNEL_HOP_SEQ * Host tells the Sniffer which order to cycle through the channels * when following an advertiser. * * 0xFE = GO_IDLE * Host tell the Sniffer to stop sending UART traffic and listen for * new commands. * * Payloads: * * Protocol version < 3: * EVENT_PACKET (ID 0x06) * * Protocol version 3: * EVENT_PACKET_ADVERTISING (ID 0x02) * EVENT_PACKET_DATA (ID 0x06) * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Length of payload data (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Flags (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Channel (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | RSSISample (dBm) (1 byte) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Event counter | * | (2 bytes) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * | Protocol version < 3: Delta time (us end to start) | * | (4 bytes) | * | Protocol version 3: Firmware Timestamp (us) | * | (4 bytes) | * +--------+--------+--------+--------+--------+--------+--------+--------+ * * +--------+--------+--------+--------+--------+--------+--------+--------+ * | | * | Bluetooth Low Energy Link Layer Packet (excluding preamble) | * | ... | * | | * +--------+--------+--------+--------+--------+--------+--------+--------+ * * Flags EVENT_PACKET_ADVERTISING (0x02) * 0000000x = CRC (0 = Incorrect, 1 = OK) * 000000x0 = RFU * 00000x00 = RFU * 00000xx0 = AUX_TYPE (channel < 37: 0 = AUX_ADV_IND, 1 = AUX_CHAIN_IND, * 2 = AUX_SYNC_IND, 3 = AUX_SCAN_RSP) * 0000x000 = RFU * 0xxx0000 = PHY (0 = 1M, 1 = 2M, 2 = Coded, rest unused) * x0000000 = RFU * * Flags EVENT_PACKET_DATA (0x06) * 0000000x = CRC (0 = Incorrect, 1 = OK) * 000000x0 = Direction (0 = Slave -> Master, 1 = Master -> Slave) * 00000x00 = Encrypted (0 = No, 1 = Yes) * 0000x000 = MIC (0 = Incorrect, 1 = OK) * 0xxx0000 = PHY (0 = 1M, 1 = 2M, 2 = Coded, rest unused) * x0000000 = RFU * * Channel: * The channel index being used. * * RSSIsample: * RSSI sample raw value. The value of this register is read as a * positive value while the actual received signal strength is a * negative value. Actual received signal strength is therefore * as follows: rssi = -RSSISAMPLE dBm * * Delta time: * This is the time in microseconds from the end of the previous received * packet to the beginning of this packet. * * Firmware timestamp: * Timestamp of the start of the received packet captured by the firmware * timer with microsecond resolution. */ #include "config.h" #include #include #include #include #include #include "packet-btle.h" /* Size of various UART Packet header fields */ #define UART_HEADER_LEN 6 #define EVENT_PACKET_LEN 10 #define US_PER_BYTE_1M_PHY 8 #define US_PER_BYTE_2M_PHY 4 #define US_PER_BYTE_CODED_PHY_S8 64 #define US_PER_BYTE_CODED_PHY_S2 16 #define PREAMBLE_LEN_1M_PHY 1 #define PREAMBLE_LEN_2M_PHY 2 /* Preamble + Access Address + CI + TERM1 */ #define FEC1_BLOCK_S8_US (80 + 256 + 16 + 24) #define TERM2_S8_US 24 #define TERM2_S2_US 6 void proto_reg_handoff_nordic_ble(void); void proto_register_nordic_ble(void); /* Initialize the protocol and registered fields */ static int proto_nordic_ble = -1; /* Initialize the subtree pointers */ static gint ett_nordic_ble = -1; static gint ett_packet_header = -1; static gint ett_flags = -1; static int hf_nordic_ble_board_id = -1; static int hf_nordic_ble_legacy_marker = -1; static int hf_nordic_ble_header = -1; static int hf_nordic_ble_header_length = -1; static int hf_nordic_ble_payload_length = -1; static int hf_nordic_ble_protover = -1; static int hf_nordic_ble_packet_counter = -1; static int hf_nordic_ble_packet_id = -1; static int hf_nordic_ble_packet_length = -1; static int hf_nordic_ble_flags = -1; static int hf_nordic_ble_crcok = -1; static int hf_nordic_ble_encrypted = -1; static int hf_nordic_ble_micok = -1; static int hf_nordic_ble_mic_not_relevant = -1; static int hf_nordic_ble_aux_type = -1; static int hf_nordic_ble_flag_reserved1 = -1; static int hf_nordic_ble_flag_reserved2 = -1; static int hf_nordic_ble_address_resolved = -1; static int hf_nordic_ble_flag_reserved7 = -1; static int hf_nordic_ble_le_phy = -1; static int hf_nordic_ble_direction = -1; static int hf_nordic_ble_channel = -1; static int hf_nordic_ble_rssi = -1; static int hf_nordic_ble_event_counter = -1; static int hf_nordic_ble_time = -1; static int hf_nordic_ble_delta_time = -1; static int hf_nordic_ble_delta_time_ss = -1; static int hf_nordic_ble_packet_time = -1; static expert_field ei_nordic_ble_bad_crc = EI_INIT; static expert_field ei_nordic_ble_bad_mic = EI_INIT; static expert_field ei_nordic_ble_bad_length = EI_INIT; static expert_field ei_nordic_ble_unknown_version = EI_INIT; static const true_false_string direction_tfs = { "Master -> Slave", "Slave -> Master" }; static const value_string le_phys[] = { { 0, "LE 1M" }, { 1, "LE 2M" }, { 2, "LE Coded" }, { 3, "Reserved" }, { 4, "Reserved" }, { 5, "Reserved" }, { 6, "Reserved" }, { 7, "Reserved" }, { 0, NULL } }; #define CI_S8 0 #define CI_S2 1 static const value_string le_aux_ext_adv[] = { { 0, "AUX_ADV_IND" }, { 1, "AUX_CHAIN_IND" }, { 2, "AUX_SYNC_IND" }, { 3, "AUX_SCAN_RSP" }, { 0, NULL } }; typedef struct { guint8 protover; guint8 phy; gboolean bad_length; guint16 payload_length; guint16 event_packet_length; } nordic_ble_context_t; /* next dissector */ static dissector_handle_t btle_dissector_handle = NULL; static dissector_handle_t debug_handle = NULL; static gint dissect_lengths(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree, nordic_ble_context_t *nordic_ble_context) { guint32 hlen, plen; proto_item* item; switch (nordic_ble_context->protover) { case 0: /* Legacy version */ hlen = 2 + UART_HEADER_LEN; /* 2 bytes legacy marker + UART header */ item = proto_tree_add_item_ret_uint(tree, hf_nordic_ble_payload_length, tvb, offset, 1, ENC_NA, &plen); offset += 1; break; case 1: proto_tree_add_item_ret_uint(tree, hf_nordic_ble_header_length, tvb, offset, 1, ENC_NA, &hlen); hlen += 1; /* Add one byte for board id */ offset += 1; item = proto_tree_add_item_ret_uint(tree, hf_nordic_ble_payload_length, tvb, offset, 1, ENC_NA, &plen); offset += 1; break; default: /* Starting from version 2 */ hlen = 1 + UART_HEADER_LEN; /* Board ID + UART header */ item = proto_tree_add_item_ret_uint(tree, hf_nordic_ble_payload_length, tvb, offset, 2, ENC_LITTLE_ENDIAN, &plen); offset += 2; break; } if ((hlen + plen) != tvb_captured_length(tvb)) { expert_add_info(pinfo, item, &ei_nordic_ble_bad_length); nordic_ble_context->bad_length = TRUE; } nordic_ble_context->payload_length = plen; return offset; } static gint dissect_flags(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree, nordic_ble_context_t *nordic_ble_context, btle_context_t *context) { guint8 flags, channel; gboolean dir; proto_item *flags_item, *item; proto_tree *flags_tree; flags = tvb_get_guint8(tvb, offset); channel = tvb_get_guint8(tvb, offset + 1); if (nordic_ble_context->protover < 3) { guint32 access_address; access_address = tvb_get_letohl(tvb, offset + nordic_ble_context->event_packet_length - 1); context->pdu_type = access_address == ACCESS_ADDRESS_ADVERTISING ? BTLE_PDU_TYPE_ADVERTISING : BTLE_PDU_TYPE_DATA; } context->crc_checked_at_capture = 1; context->crc_valid_at_capture = !!(flags & 1); if (context->pdu_type == BTLE_PDU_TYPE_DATA) { dir = !!(flags & 2); context->mic_checked_at_capture = !!(flags & 4); if (context->mic_checked_at_capture) { context->mic_valid_at_capture = !!(flags & 8); } } nordic_ble_context->phy = (flags >> 4) & 7; context->phy = nordic_ble_context->phy; if (context->pdu_type == BTLE_PDU_TYPE_DATA) { if (dir) { set_address(&pinfo->src, AT_STRINGZ, 7, "Master"); set_address(&pinfo->dst, AT_STRINGZ, 6, "Slave"); context->direction = BTLE_DIR_MASTER_SLAVE; pinfo->p2p_dir = P2P_DIR_SENT; } else { set_address(&pinfo->src, AT_STRINGZ, 6, "Slave"); set_address(&pinfo->dst, AT_STRINGZ, 7, "Master"); context->direction = BTLE_DIR_SLAVE_MASTER; pinfo->p2p_dir = P2P_DIR_RECV; } } flags_item = proto_tree_add_item(tree, hf_nordic_ble_flags, tvb, offset, 1, ENC_NA); flags_tree = proto_item_add_subtree(flags_item, ett_flags); item = proto_tree_add_item(flags_tree, hf_nordic_ble_crcok, tvb, offset, 1, ENC_NA); if (!context->crc_valid_at_capture) { /* CRC is bad */ expert_add_info(pinfo, item, &ei_nordic_ble_bad_crc); } if (context->pdu_type == BTLE_PDU_TYPE_DATA) { proto_tree_add_item(flags_tree, hf_nordic_ble_direction, tvb, offset, 1, ENC_NA); proto_tree_add_item(flags_tree, hf_nordic_ble_encrypted, tvb, offset, 1, ENC_NA); if (context->mic_checked_at_capture) { item = proto_tree_add_item(flags_tree, hf_nordic_ble_micok, tvb, offset, 1, ENC_NA); if (!context->mic_valid_at_capture) { /* MIC is bad */ expert_add_info(pinfo, item, &ei_nordic_ble_bad_mic); } } else { proto_tree_add_item(flags_tree, hf_nordic_ble_mic_not_relevant, tvb, offset, 1, ENC_NA); } } else { if (channel < 37) { guint32 aux_pdu_type; proto_tree_add_item_ret_uint(flags_tree, hf_nordic_ble_aux_type, tvb, offset, 1, ENC_NA, &aux_pdu_type); context->aux_pdu_type = aux_pdu_type; context->aux_pdu_type_valid = TRUE; } else { proto_tree_add_item(flags_tree, hf_nordic_ble_flag_reserved1, tvb, offset, 1, ENC_NA); proto_tree_add_item(flags_tree, hf_nordic_ble_flag_reserved2, tvb, offset, 1, ENC_NA); } proto_tree_add_item(flags_tree, hf_nordic_ble_address_resolved, tvb, offset, 1, ENC_NA); } proto_tree_add_item(flags_tree, hf_nordic_ble_le_phy, tvb, offset, 1, ENC_NA); proto_tree_add_item(flags_tree, hf_nordic_ble_flag_reserved7, tvb, offset, 1, ENC_NA); offset++; return offset; } static guint16 packet_time_get(nordic_ble_context_t *nordic_ble_context, guint8 ci) { /* Calculate packet time according to this packets PHY */ guint16 ble_payload_length = nordic_ble_context->payload_length - nordic_ble_context->event_packet_length; switch (nordic_ble_context->phy) { case LE_1M_PHY: return US_PER_BYTE_1M_PHY * (PREAMBLE_LEN_1M_PHY + ble_payload_length); case LE_2M_PHY: return US_PER_BYTE_2M_PHY * (PREAMBLE_LEN_2M_PHY + ble_payload_length); case LE_CODED_PHY: { /* Subtract Access address and CI */ guint16 fec2_block_len = ble_payload_length - 4 - 1; switch (ci) { case CI_S8: return FEC1_BLOCK_S8_US + fec2_block_len * US_PER_BYTE_CODED_PHY_S8 + TERM2_S8_US; case CI_S2: return FEC1_BLOCK_S8_US + fec2_block_len * US_PER_BYTE_CODED_PHY_S2 + TERM2_S2_US; } } /* Fallthrough */ default: return 0; /* Unknown */ } } typedef struct { guint32 packet_start_time; guint32 packet_end_time; } packet_times_t; typedef struct { gboolean first_frame_seen; /* Time information about previous packet times to calculate delta times */ guint32 packet_time; guint32 packet_start_time; guint32 packet_end_time; } packet_time_context_t; static wmem_tree_t *packet_time_context_tree; static packet_time_context_t *packet_times_get(packet_info *pinfo) { guint32 interface_id = (pinfo->rec->presence_flags & WTAP_HAS_INTERFACE_ID) ? pinfo->rec->rec_header.packet_header.interface_id: HCI_INTERFACE_DEFAULT; wmem_tree_t *wmem_tree; wmem_tree_key_t keys[2]; keys[0].length = 1; keys[0].key = &interface_id; keys[1].length = 0; keys[1].key = NULL; wmem_tree = (wmem_tree_t *) wmem_tree_lookup32_array(packet_time_context_tree, keys); if (wmem_tree) { return (packet_time_context_t *) wmem_tree_lookup32_le(wmem_tree, 0); } return NULL; } static packet_time_context_t *packet_times_insert(packet_info *pinfo) { guint32 interface_id = (pinfo->rec->presence_flags & WTAP_HAS_INTERFACE_ID) ? pinfo->rec->rec_header.packet_header.interface_id: HCI_INTERFACE_DEFAULT; guint32 key = 0; wmem_tree_key_t keys[3]; packet_time_context_t *packet_times; keys[0].length = 1; keys[0].key = &interface_id; keys[1].length = 1; keys[1].key = &key; keys[2].length = 0; keys[2].key = NULL; packet_times = wmem_new0(wmem_file_scope(), packet_time_context_t); wmem_tree_insert32_array(packet_time_context_tree, keys, packet_times); return packet_times; } static gint dissect_ble_delta_time(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree, nordic_ble_context_t *nordic_ble_context) { guint32 delta_time, delta_time_ss, prev_packet_time, packet_time; proto_item *pi; packet_time_context_t *packet_times_context; packet_times_context = packet_times_get(pinfo); if (!packet_times_context) { packet_times_context = packet_times_insert(pinfo); } /* end-to-start */ proto_tree_add_item_ret_uint(tree, hf_nordic_ble_delta_time, tvb, offset, 4, ENC_LITTLE_ENDIAN, &delta_time); if (!pinfo->fd->visited) { /* First time visiting this packet, store previous BLE packet time */ p_add_proto_data(wmem_file_scope(), pinfo, proto_nordic_ble, 0, GUINT_TO_POINTER(packet_times_context->packet_time)); prev_packet_time = packet_times_context->packet_time; } else { prev_packet_time = GPOINTER_TO_UINT(p_get_proto_data(wmem_file_scope(), pinfo, proto_nordic_ble, 0)); } if (!packet_times_context->first_frame_seen) { delta_time_ss = prev_packet_time + delta_time; pi = proto_tree_add_uint(tree, hf_nordic_ble_delta_time_ss, tvb, offset, 4, delta_time_ss); proto_item_set_generated(pi); } packet_time = packet_time_get(nordic_ble_context, 0 /* This version never supported Coded PHY */); pi = proto_tree_add_uint(tree, hf_nordic_ble_packet_time, tvb, offset, 4, packet_time); proto_item_set_generated(pi); offset += 4; if (!pinfo->fd->visited) { packet_times_context->packet_time = packet_time; packet_times_context->first_frame_seen = TRUE; } return offset; } static gint dissect_ble_timestamp(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree, nordic_ble_context_t *nordic_ble_context) { guint32 delta_time, delta_time_ss, packet_time; guint32 timestamp, last_packet_end_time, last_packet_start_time; proto_item *item; packet_time_context_t *packet_times_context; packet_times_context = packet_times_get(pinfo); if (!packet_times_context) { packet_times_context = packet_times_insert(pinfo); } proto_tree_add_item_ret_uint(tree, hf_nordic_ble_time, tvb, offset, 4, ENC_LITTLE_ENDIAN, ×tamp); if (!pinfo->fd->visited) { packet_times_t *saved_packet_times = wmem_new0(wmem_file_scope(), packet_times_t); saved_packet_times->packet_end_time = packet_times_context->packet_end_time; saved_packet_times->packet_start_time = packet_times_context->packet_start_time; p_add_proto_data(wmem_file_scope(), pinfo, proto_nordic_ble, 0, saved_packet_times); /* First time visiting this packet, store previous BLE packet time */ last_packet_end_time = packet_times_context->packet_end_time; last_packet_start_time = packet_times_context->packet_start_time; } else { packet_times_t* saved_packet_times = (packet_times_t *)p_get_proto_data(wmem_file_scope(), pinfo, proto_nordic_ble, 0); last_packet_end_time = saved_packet_times->packet_end_time; last_packet_start_time = saved_packet_times->packet_start_time; } guint8 ci = tvb_get_guint8(tvb, offset + 4 + 4); packet_time = packet_time_get(nordic_ble_context, ci); item = proto_tree_add_uint(tree, hf_nordic_ble_packet_time, tvb, offset, 4, packet_time); proto_item_set_generated(item); if (pinfo->num > 1) { /* Calculated delta times are not valid for the first packet because we don't have the last packet times. */ delta_time = timestamp - last_packet_end_time; item = proto_tree_add_uint(tree, hf_nordic_ble_delta_time, tvb, offset, 4, delta_time); proto_item_set_generated(item); delta_time_ss = timestamp - last_packet_start_time; item = proto_tree_add_uint(tree, hf_nordic_ble_delta_time_ss, tvb, offset, 4, delta_time_ss); proto_item_set_generated(item); } if (!pinfo->fd->visited) { packet_times_context->packet_start_time = timestamp; packet_times_context->packet_end_time = timestamp + packet_time; packet_times_context->first_frame_seen = TRUE; } offset += 4; return offset; } static gint dissect_packet_counter(tvbuff_t *tvb, gint offset, proto_item *item, proto_tree *tree) { proto_item_append_text(item, ", Packet counter: %u", tvb_get_guint16(tvb, offset, ENC_LITTLE_ENDIAN)); proto_tree_add_item(tree, hf_nordic_ble_packet_counter, tvb, offset, 2, ENC_LITTLE_ENDIAN); offset += 2; return offset; } static gint dissect_packet_header(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree, nordic_ble_context_t *nordic_ble_context, btle_context_t *context) { proto_item *ti; proto_tree *header_tree; gint start_offset = offset; ti = proto_tree_add_item(tree, hf_nordic_ble_header, tvb, offset, -1, ENC_NA); header_tree = proto_item_add_subtree(ti, ett_packet_header); proto_item_append_text(ti, " Version: %u", nordic_ble_context->protover); if (nordic_ble_context->protover == 0) { proto_item *item = proto_tree_add_uint(header_tree, hf_nordic_ble_protover, tvb, 0, 0, 0); proto_item_set_generated(item); proto_tree_add_item(header_tree, hf_nordic_ble_packet_id, tvb, offset, 1, ENC_NA); offset += 1; offset = dissect_packet_counter(tvb, offset, ti, header_tree); offset += 2; // Two unused bytes } offset = dissect_lengths(tvb, offset, pinfo, header_tree, nordic_ble_context); if (nordic_ble_context->protover != 0) { proto_item *item = proto_tree_add_item(header_tree, hf_nordic_ble_protover, tvb, offset, 1, ENC_NA); offset += 1; if (nordic_ble_context->protover > 3) { expert_add_info(pinfo, item, &ei_nordic_ble_unknown_version); } offset = dissect_packet_counter(tvb, offset, ti, header_tree); proto_tree_add_item(header_tree, hf_nordic_ble_packet_id, tvb, offset, 1, ENC_NA); if (nordic_ble_context->protover > 2) { guint8 id = tvb_get_guint8(tvb, offset); context->pdu_type = id == 0x06 ? BTLE_PDU_TYPE_DATA : id == 0x02 ? BTLE_PDU_TYPE_ADVERTISING : BTLE_PDU_TYPE_UNKNOWN; } offset += 1; } proto_item_set_len(ti, offset - start_offset); return offset; } static gint dissect_packet(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree, nordic_ble_context_t *nordic_ble_context, btle_context_t *context) { gint32 rssi; guint32 channel, event_counter; if (nordic_ble_context->protover == 0) { // Event packet length is fixed for the legacy version nordic_ble_context->event_packet_length = EVENT_PACKET_LEN; } else { guint32 plen; proto_tree_add_item_ret_uint(tree, hf_nordic_ble_packet_length, tvb, offset, 1, ENC_NA, &plen); nordic_ble_context->event_packet_length = plen; offset += 1; } offset = dissect_flags(tvb, offset, pinfo, tree, nordic_ble_context, context); proto_tree_add_item_ret_uint(tree, hf_nordic_ble_channel, tvb, offset, 1, ENC_NA, &channel); offset += 1; context->channel = channel; rssi = (-1)*((gint32)tvb_get_guint8(tvb, offset)); proto_tree_add_int(tree, hf_nordic_ble_rssi, tvb, offset, 1, rssi); offset += 1; proto_tree_add_item_ret_uint(tree, hf_nordic_ble_event_counter, tvb, offset, 2, ENC_LITTLE_ENDIAN, &event_counter); offset += 2; context->event_counter = event_counter; context->event_counter_valid = 1; if (nordic_ble_context->protover < 3) { offset = dissect_ble_delta_time(tvb, offset, pinfo, tree, nordic_ble_context); } else { offset = dissect_ble_timestamp(tvb, offset, pinfo, tree, nordic_ble_context); } return offset; } static gint dissect_header(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, btle_context_t *context, gboolean *bad_length) { proto_item *ti; proto_tree *nordic_ble_tree; gint offset = 0; nordic_ble_context_t nordic_ble_context; memset(&nordic_ble_context, 0, sizeof(nordic_ble_context)); ti = proto_tree_add_item(tree, proto_nordic_ble, tvb, 0, -1, ENC_NA); nordic_ble_tree = proto_item_add_subtree(ti, ett_nordic_ble); if (tvb_get_guint16(tvb, 0, ENC_BIG_ENDIAN) == 0xBEEF) { proto_tree_add_item(nordic_ble_tree, hf_nordic_ble_legacy_marker, tvb, 0, 2, ENC_BIG_ENDIAN); offset += 2; nordic_ble_context.protover = 0; /* Legacy Version */ } else { proto_tree_add_item(nordic_ble_tree, hf_nordic_ble_board_id, tvb, 0, 1, ENC_NA); offset += 1; nordic_ble_context.protover = tvb_get_guint8(tvb, offset + 2); } offset = dissect_packet_header(tvb, offset, pinfo, nordic_ble_tree, &nordic_ble_context, context); offset = dissect_packet(tvb, offset, pinfo, nordic_ble_tree, &nordic_ble_context, context); proto_item_set_len(ti, offset); *bad_length = nordic_ble_context.bad_length; return offset; } /* Main entry point for sniffer */ static int dissect_nordic_ble(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_) { tvbuff_t *payload_tvb; btle_context_t *context; gint offset; gboolean bad_length = FALSE; context = wmem_new0(pinfo->pool, btle_context_t); offset = dissect_header(tvb, pinfo, tree, context, &bad_length); payload_tvb = tvb_new_subset_length_caplen(tvb, offset, -1, tvb_captured_length(tvb) - offset); if (!bad_length) { call_dissector_with_data(btle_dissector_handle, payload_tvb, pinfo, tree, context); } if ((context->mic_checked_at_capture) && (!context->mic_valid_at_capture)) { col_set_str(pinfo->cinfo, COL_INFO, "Encrypted packet decrypted incorrectly"); if (!context->crc_valid_at_capture) { /* CRC is bad */ col_append_str(pinfo->cinfo, COL_INFO, " (bad CRC)"); } else { col_append_str(pinfo->cinfo, COL_INFO, " (bad MIC)"); } } if (debug_handle) { call_dissector(debug_handle, payload_tvb, pinfo, tree); } return offset; } void proto_register_nordic_ble(void) { static hf_register_info hf[] = { { &hf_nordic_ble_board_id, { "Board", "nordic_ble.board_id", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_legacy_marker, { "Legacy marker", "nordic_ble.legacy_marker", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_header, { "Header", "nordic_ble.header", FT_NONE, BASE_NONE, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_header_length, { "Length of header", "nordic_ble.hlen", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_payload_length, { "Length of payload", "nordic_ble.plen", FT_UINT16, BASE_DEC, NULL, 0x0, "Payload length", HFILL } }, { &hf_nordic_ble_protover, { "Protocol version", "nordic_ble.protover", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_packet_counter, { "Packet counter", "nordic_ble.packet_counter", FT_UINT16, BASE_DEC, NULL, 0x0, "Global packet counter for packets sent on UART", HFILL } }, { &hf_nordic_ble_packet_id, { "Packet ID", "nordic_ble.packet_id", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_packet_length, { "Length of packet", "nordic_ble.len", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_flags, { "Flags", "nordic_ble.flags", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_crcok, { "CRC", "nordic_ble.crcok", FT_BOOLEAN, 8, TFS(&tfs_ok_error), 0x01, "Cyclic Redundancy Check state", HFILL } }, { &hf_nordic_ble_direction, { "Direction", "nordic_ble.direction", FT_BOOLEAN, 8, TFS(&direction_tfs), 0x02, NULL, HFILL } }, { &hf_nordic_ble_flag_reserved1, { "Reserved", "nordic_ble.flag_reserved1", FT_UINT8, BASE_DEC, NULL, 0x02, NULL, HFILL } }, { &hf_nordic_ble_encrypted, { "Encrypted", "nordic_ble.encrypted", FT_BOOLEAN, 8, TFS(&tfs_yes_no), 0x04, "Was the packet encrypted", HFILL } }, { &hf_nordic_ble_flag_reserved2, { "Reserved", "nordic_ble.flag_reserved2", FT_UINT8, BASE_DEC, NULL, 0x04, NULL, HFILL } }, { &hf_nordic_ble_aux_type, { "Aux Type", "nordic_ble.aux_type", FT_UINT8, BASE_DEC, VALS(le_aux_ext_adv), 0x06, NULL, HFILL } }, { &hf_nordic_ble_micok, { "MIC", "nordic_ble.micok", FT_BOOLEAN, 8, TFS(&tfs_ok_error), 0x08, "Message Integrity Check state", HFILL } }, { &hf_nordic_ble_mic_not_relevant, { "MIC (not relevant)", "nordic_ble.mic_not_relevant", FT_UINT8, BASE_DEC, NULL, 0x08, "Message Integrity Check state is only relevant when encrypted", HFILL } }, { &hf_nordic_ble_address_resolved, { "Address Resolved", "nordic_ble.address_resolved", FT_BOOLEAN, 8, TFS(&tfs_yes_no), 0x08, NULL, HFILL } }, { &hf_nordic_ble_le_phy, { "PHY", "nordic_ble.phy", FT_UINT8, BASE_DEC, VALS(le_phys), 0x70, "Physical Layer", HFILL } }, { &hf_nordic_ble_flag_reserved7, { "Reserved", "nordic_ble.flag_reserved7", FT_UINT8, BASE_DEC, NULL, 0x80, "Reserved for Future Use", HFILL } }, { &hf_nordic_ble_channel, { "Channel Index", "nordic_ble.channel", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_rssi, { "RSSI", "nordic_ble.rssi", FT_INT8, BASE_DEC | BASE_UNIT_STRING, &units_dbm, 0x0, "Received Signal Strength Indicator", HFILL } }, { &hf_nordic_ble_event_counter, { "Event counter", "nordic_ble.event_counter", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL } }, { &hf_nordic_ble_time, { "Timestamp", "nordic_ble.time", FT_UINT32, BASE_DEC | BASE_UNIT_STRING, &units_microseconds, 0x0, "Firmware timestamp", HFILL } }, { &hf_nordic_ble_delta_time, { "Delta time (end to start)", "nordic_ble.delta_time", FT_UINT32, BASE_DEC | BASE_UNIT_STRING, &units_microseconds, 0x0, "Time since end of last reported packet", HFILL } }, { &hf_nordic_ble_delta_time_ss, { "Delta time (start to start)", "nordic_ble.delta_time_ss", FT_UINT32, BASE_DEC | BASE_UNIT_STRING, &units_microseconds, 0x0, "Time since start of last reported packet", HFILL } }, { &hf_nordic_ble_packet_time, { "Packet time (start to end)", "nordic_ble.packet_time", FT_UINT32, BASE_DEC | BASE_UNIT_STRING, &units_microseconds, 0x0, "Time of packet", HFILL } }, }; static gint *ett[] = { &ett_nordic_ble, &ett_packet_header, &ett_flags }; static ei_register_info ei[] = { { &ei_nordic_ble_bad_crc, { "nordic_ble.crc.bad", PI_CHECKSUM, PI_ERROR, "CRC is bad", EXPFILL }}, { &ei_nordic_ble_bad_mic, { "nordic_ble.mic.bad", PI_CHECKSUM, PI_ERROR, "MIC is bad", EXPFILL }}, { &ei_nordic_ble_bad_length, { "nordic_ble.length.bad", PI_MALFORMED, PI_ERROR, "Length is incorrect", EXPFILL }}, { &ei_nordic_ble_unknown_version, { "nordic_ble.protover.bad", PI_PROTOCOL, PI_ERROR, "Unknown version", EXPFILL }}, }; expert_module_t *expert_nordic_ble; packet_time_context_tree = wmem_tree_new_autoreset(wmem_epan_scope(), wmem_file_scope()); proto_nordic_ble = proto_register_protocol("nRF Sniffer for Bluetooth LE", "NORDIC_BLE", "nordic_ble"); register_dissector("nordic_ble", dissect_nordic_ble, proto_nordic_ble); expert_nordic_ble = expert_register_protocol(proto_nordic_ble); expert_register_field_array(expert_nordic_ble, ei, array_length(ei)); proto_register_field_array(proto_nordic_ble, hf, array_length(hf)); proto_register_subtree_array(ett, array_length(ett)); } void proto_reg_handoff_nordic_ble(void) { dissector_handle_t nordic_ble_handle; nordic_ble_handle = create_dissector_handle(dissect_nordic_ble, proto_nordic_ble); btle_dissector_handle = find_dissector("btle"); debug_handle = find_dissector("nordic_debug"); dissector_add_for_decode_as_with_preference("udp.port", nordic_ble_handle); dissector_add_uint("wtap_encap", WTAP_ENCAP_NORDIC_BLE, nordic_ble_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: */