gd/l2cap/l2cap_packets.pdl

little_endian_packets

checksum Fcs : 16 "l2cap/"

packet BasicFrame {
  _size_(_payload_) : 16,
  channel_id : 16,
  _payload_,
}

packet BasicFrameWithFcs {
  _checksum_start_(fcs),
  _size_(_payload_) : 16,
  channel_id : 16,
  _payload_ : [+2*8], // Include Fcs in the _size_
  fcs : Fcs,
}

enum Continuation : 1 {
  END = 0,
  CONTINUE = 1,
}

// ChannelId 2 is connectionless
packet GroupFrame : BasicFrame (channel_id = 0x02) {
  psm : 16,
  _payload_,
}

enum FrameType : 1 {
  I_FRAME = 0,
  S_FRAME = 1,
}

enum SupervisoryFunction : 2 {
  RECEIVER_READY = 0,
  REJECT = 1,
  RECEIVER_NOT_READY = 2,
  SELECT_REJECT = 3,
}

enum RetransmissionDisable : 1 {
  NORMAL = 0,
  DISABLE = 1,
}

enum SegmentationAndReassembly : 2 {
  UNSEGMENTED = 0,
  START = 1,
  END = 2,
  CONTINUATION = 3,
}

packet StandardFrame : BasicFrame {
  frame_type : FrameType,
  _body_,
}

packet StandardFrameWithFcs : BasicFrameWithFcs {
  frame_type : FrameType,
  _body_,
}

group StandardSupervisoryControl {
  _fixed_ = 0 : 1,
  s : SupervisoryFunction,
  _reserved_ : 3,
  r : RetransmissionDisable,
  req_seq : 6,
  _reserved_ : 2,
}

group StandardInformationControl {
  tx_seq : 6,
  r : RetransmissionDisable,
  req_seq : 6,
  sar : SegmentationAndReassembly,
}

packet StandardSupervisoryFrame : StandardFrame (frame_type = S_FRAME) {
  StandardSupervisoryControl,
}

packet StandardSupervisoryFrameWithFcs : StandardFrameWithFcs (frame_type = S_FRAME) {
  StandardSupervisoryControl,
}

packet StandardInformationFrame : StandardFrame (frame_type = I_FRAME) {
  StandardInformationControl,
  _payload_,
}

packet StandardInformationFrameWithFcs : StandardFrameWithFcs (frame_type = I_FRAME) {
  StandardInformationControl,
  _payload_,
}

packet StandardInformationStartFrame : StandardInformationFrame (sar = START) {
  l2cap_sdu_length : 16,
  _payload_,
}

packet StandardInformationStartFrameWithFcs : StandardInformationFrameWithFcs (sar = START) {
  l2cap_sdu_length : 16,
  _payload_,
}

enum Poll : 1 {
  NOT_SET = 0,
  POLL = 1,
}

enum Final : 1 {
  NOT_SET = 0,
  POLL_RESPONSE = 1,
}

group EnhancedSupervisoryControl {
  _fixed_ = 0 : 1,
  s : SupervisoryFunction,
  p : Poll,
  _reserved_ : 2,
  f : Final,
  req_seq : 6,
  _reserved_ : 2,
}

group EnhancedInformationControl {
  tx_seq : 6,
  f : Final,
  req_seq : 6,
  sar : SegmentationAndReassembly,
}

packet EnhancedSupervisoryFrame : StandardFrame (frame_type = S_FRAME) {
  EnhancedSupervisoryControl,
}

packet EnhancedSupervisoryFrameWithFcs : StandardFrameWithFcs (frame_type = S_FRAME) {
  EnhancedSupervisoryControl,
}

packet EnhancedInformationFrame : StandardFrame (frame_type = I_FRAME) {
  EnhancedInformationControl,
  _payload_,
}

packet EnhancedInformationFrameWithFcs : StandardFrameWithFcs (frame_type = I_FRAME) {
  EnhancedInformationControl,
  _payload_,
}

packet EnhancedInformationStartFrame : EnhancedInformationFrame (sar = START) {
  l2cap_sdu_length : 16,
  _payload_,
}

packet EnhancedInformationStartFrameWithFcs : EnhancedInformationFrameWithFcs (sar = START) {
  l2cap_sdu_length : 16,
  _payload_,
}

group ExtendedSupervisoryControl {
  f : Final,
  req_seq : 14,
  s : SupervisoryFunction,
  p : Poll,
  _reserved_ : 5,
  _reserved_ : 8,
}

group ExtendedInformationControl {
  f : Final,
  req_seq : 14,
  sar : SegmentationAndReassembly,
  tx_seq : 14,
}

packet ExtendedSupervisoryFrame : StandardFrame (frame_type = S_FRAME) {
  ExtendedSupervisoryControl,
}

packet ExtendedSupervisoryFrameWithFcs : StandardFrameWithFcs (frame_type = S_FRAME) {
  ExtendedSupervisoryControl,
}

packet ExtendedInformationFrame : StandardFrame (frame_type = I_FRAME) {
  ExtendedInformationControl,
  _payload_,
}

packet ExtendedInformationFrameWithFcs : StandardFrameWithFcs (frame_type = I_FRAME) {
  ExtendedInformationControl,
  _payload_,
}

packet ExtendedInformationStartFrame : ExtendedInformationFrame (sar = START) {
  l2cap_sdu_length : 16,
  _payload_,
}

packet ExtendedInformationStartFrameWithFcs : ExtendedInformationFrameWithFcs (sar = START) {
  l2cap_sdu_length : 16,
  _payload_,
}

packet FirstLeInformationFrame : BasicFrame {
  l2cap_sdu_length : 16,
  _payload_,
}

enum CommandCode : 8 {
  COMMAND_REJECT = 0x01,
  CONNECTION_REQUEST = 0x02,
  CONNECTION_RESPONSE = 0x03,
  CONFIGURATION_REQUEST = 0x04,
  CONFIGURATION_RESPONSE = 0x05,
  DISCONNECTION_REQUEST = 0x06,
  DISCONNECTION_RESPONSE = 0x07,
  ECHO_REQUEST = 0x08,
  ECHO_RESPONSE = 0x09,
  INFORMATION_REQUEST = 0x0A,
  INFORMATION_RESPONSE = 0x0B,
  CREATE_CHANNEL_REQUEST = 0x0C,
  CREATE_CHANNEL_RESPONSE = 0x0D,
  MOVE_CHANNEL_REQUEST = 0x0E,
  MOVE_CHANNEL_RESPONSE = 0x0F,
  MOVE_CHANNEL_CONFIRMATION_REQUEST = 0x10,
  MOVE_CHANNEL_CONFIRMATION_RESPONSE = 0x11,
}

packet ControlFrame : BasicFrame (channel_id = 0x0001) {
  _payload_,
}

packet Control {
  code : CommandCode,
  identifier : 8,
  _size_(_payload_) : 16,
  _payload_,
}

enum CommandRejectReason : 16 {
  COMMAND_NOT_UNDERSTOOD = 0x0000,
  SIGNALING_MTU_EXCEEDED = 0x0001,
  INVALID_CID_IN_REQUEST = 0x0002,
}

packet CommandReject : Control (code = COMMAND_REJECT) {
  reason : CommandRejectReason,
  _body_,
}

packet CommandRejectNotUnderstood : CommandReject (reason = COMMAND_NOT_UNDERSTOOD) {
}

packet CommandRejectMtuExceeded : CommandReject (reason = SIGNALING_MTU_EXCEEDED) {
  actual_mtu : 16,
}

packet CommandRejectInvalidCid : CommandReject (reason = INVALID_CID_IN_REQUEST) {
  local_channel : 16, // Relative to the sender of the CommandReject
  remote_channel : 16,
}

packet ConnectionRequest : Control (code = CONNECTION_REQUEST) {
  psm : 16,
  source_cid : 16,
}

enum ConnectionResponseResult : 16 {
  SUCCESS = 0x0000,
  PENDING = 0x0001,
  PSM_NOT_SUPPORTED = 0x0002,
  SECURITY_BLOCK = 0x0003,
  NO_RESOURCES_AVAILABLE = 0x0004,
  INVALID_CID = 0x0006,
  SOURCE_CID_ALREADY_ALLOCATED = 0x0007,
}

enum ConnectionResponseStatus : 16 {
  NO_FURTHER_INFORMATION_AVAILABLE = 0x0000,
  AUTHENTICATION_PENDING = 0x0001,
  AUTHORIZATION_PENDING = 0x0002,
}

packet ConnectionResponse : Control (code = CONNECTION_RESPONSE) {
  destination_cid : 16,
  source_cid : 16,
  result : ConnectionResponseResult,
  status : ConnectionResponseStatus,
}

enum ConfigurationOptionType : 7 {
  MTU = 0x01,
  FLUSH_TIMEOUT = 0x02,
  QUALITY_OF_SERVICE = 0x03,
  RETRANSMISSION_AND_FLOW_CONTROL = 0x04,
  FRAME_CHECK_SEQUENCE = 0x05,
  EXTENDED_FLOW_SPECIFICATION = 0x06,
  EXTENDED_WINDOW_SIZE = 0x07,
}

enum ConfigurationOptionIsHint : 1 {
  OPTION_MUST_BE_RECOGNIZED = 0,
  OPTION_IS_A_HINT = 1,
}

struct ConfigurationOption {
  type : ConfigurationOptionType,
  is_hint : ConfigurationOptionIsHint,
  length : 8,
  _body_,
}

struct MtuConfigurationOption : ConfigurationOption (type = MTU, length = 2) {
  mtu : 16,
}

struct FlushTimeoutConfigurationOption : ConfigurationOption (type = FLUSH_TIMEOUT, length = 2) {
  flush_timeout : 16,
}

enum QosServiceType : 8 {
  NO_TRAFFIC = 0x00,
  BEST_EFFORT = 0x01, // Default
  GUARANTEED = 0x02,
}

struct QualityOfServiceConfigurationOption : ConfigurationOption (type = QUALITY_OF_SERVICE, length = 22) {
  _reserved_ : 8, // Flags
  service_type : QosServiceType,
  token_rate : 32,         // 0 = ignore, 0xffffffff = max available
  token_bucket_size : 32,  // 0 = ignore, 0xffffffff = max available
  peak_bandwidth : 32,     // Octets/second 0 = ignore
  latency : 32,            // microseconds 0xffffffff = ignore
  delay_variation : 32,    // microseconds 0xffffffff = ignore
}

enum RetransmissionAndFlowControlModeOption : 8 {
  L2CAP_BASIC = 0x00,
  RETRANSMISSION = 0x01,
  FLOW_CONTROL = 0x02,
  ENHANCED_RETRANSMISSION = 0x03,
  STREAMING = 0x04,
}


struct RetransmissionAndFlowControlConfigurationOption : ConfigurationOption (type = RETRANSMISSION_AND_FLOW_CONTROL, length = 9) {
  mode : RetransmissionAndFlowControlModeOption,
  tx_window_size : 8, // 1-32 for Flow Control and Retransmission, 1-63 for Enhanced
  max_transmit : 8,
  retransmission_time_out : 16,
  monitor_time_out : 16,
  maximum_pdu_size : 16,
}

enum FcsType : 8 {
  NO_FCS = 0,
  DEFAULT = 1,  // 16-bit FCS
}

struct FrameCheckSequenceOption : ConfigurationOption (type = FRAME_CHECK_SEQUENCE, length = 1) {
  fcs_type : FcsType,
}


struct ExtendedFlowSpecificationOption : ConfigurationOption (type = EXTENDED_FLOW_SPECIFICATION, length = 16) {
  identifier : 8, // Default 0x01, must be 0x01 for Extended Flow-Best-Effort
  service_type : QosServiceType,
  maximum_sdu_size : 16, // Octets
  sdu_interarrival_time : 32, // in microseconds
  access_latency : 32, // in microseconds, without HCI and stack overheads
  flush_timeout : 32, // in microseconds 0x0 = no retransmissions 0xFFFFFFFF = never flushed
}

struct ExtendedWindowSizeOption : ConfigurationOption (type = EXTENDED_WINDOW_SIZE, length = 2) {
  max_window_size : 16, // 0x0000 = Valid for streaming, 0x0001-0x3FFF Valid for Enhanced Retransmission
}

packet ConfigurationRequest : Control (code = CONFIGURATION_REQUEST) {
  destination_cid : 16,
  continuation : Continuation,
  _reserved_ : 15,
  config : ConfigurationOption[],
}

enum ConfigurationResponseResult : 16 {
  SUCCESS = 0x0000,
  UNACCEPTABLE_PARAMETERS = 0x0001,
  REJECTED = 0x0002,
  UNKNOWN_OPTIONS = 0x0003,
  PENDING = 0x0004,
  FLOW_SPEC_REJECTED = 0x0005,
}

packet ConfigurationResponse : Control (code = CONFIGURATION_RESPONSE) {
  source_cid : 16,
  continuation : Continuation,
  _reserved_ : 15,
  result : ConfigurationResponseResult,
  config : ConfigurationOption[],
}

packet DisconnectionRequest : Control (code = DISCONNECTION_REQUEST) {
  destination_cid : 16,
  source_cid : 16,
}

packet DisconnectionResponse : Control (code = DISCONNECTION_RESPONSE) {
  destination_cid : 16,
  source_cid : 16,
}

packet EchoRequest : Control (code = ECHO_REQUEST) {
  _payload_, // Optional and implementation specific
}

packet EchoResponse : Control (code = ECHO_RESPONSE) {
  _payload_, // Optional and implementation specific
}

enum InformationRequestInfoType : 16 {
  CONNECTIONLESS_MTU = 0x0001,
  EXTENDED_FEATURES_SUPPORTED = 0x0002,
  FIXED_CHANNELS_SUPPORTED = 0x0003,
}

packet InformationRequest : Control (code = INFORMATION_REQUEST) {
  info_type : InformationRequestInfoType,
}

enum InformationRequestResult : 16 {
  SUCCESS = 0x0000,
  NOT_SUPPORTED = 0x0001,
}

packet InformationResponse : Control (code = INFORMATION_RESPONSE) {
  info_type : InformationRequestInfoType,
  result : InformationRequestResult,
  _body_,
}

packet InformationResponseConnectionlessMtu : InformationResponse (info_type = CONNECTIONLESS_MTU) {
  connectionless_mtu : 16,
}

packet InformationResponseExtendedFeatures : InformationResponse (info_type = EXTENDED_FEATURES_SUPPORTED) {
  // ExtendedFeatureMask : 32,
  flow_control_mode : 1,
  retransmission_mode : 1,
  bi_directional_qoS : 1,
  enhanced_retransmission_mode : 1,
  streaming_mode : 1,
  fcs_option : 1,
  extended_flow_specification_for_br_edr : 1,
  fixed_channels : 1,
  extended_window_size : 1,
  unicast_connectionless_data_reception : 1,
  _reserved_ : 22,
}

packet InformationResponseFixedChannels : InformationResponse (info_type = FIXED_CHANNELS_SUPPORTED) {
  fixed_channels : 64, // bit 0 must be 0, bit 1 must be 1, all others 1 = supported
}

packet CreateChannelRequest : Control (code = CREATE_CHANNEL_REQUEST) {
  psm : 16,
  source_cid : 16,
  controller_id : 8,
}

enum CreateChannelResponseResult : 16 {
  SUCCESS = 0x0000,
  PENDING = 0x0001,
  PSM_NOT_SUPPORTED = 0x0002,
  SECURITY_BLOCK = 0x0003,
  NO_RESOURCES_AVAILABLE = 0x0004,
  CONTROLLER_ID_NOT_SUPPORTED = 0x0005,
  INVALID_CID = 0x0006,
  SOURCE_CID_ALREADY_ALLOCATED = 0x0007,
}

enum CreateChannelResponseStatus : 16 {
  NO_FURTHER_INFORMATION_AVAILABLE = 0x0000,
  AUTHENTICATION_PENDING = 0x0001,
  AUTHORIZATION_PENDING = 0x0002,
}

packet CreateChannelResponse : Control (code = CREATE_CHANNEL_RESPONSE) {
  destination_cid : 16,
  source_cid : 16,
  result : CreateChannelResponseResult,
  status : CreateChannelResponseStatus,
}

// AMP Only ?
packet MoveChannelRequest : Control (code = MOVE_CHANNEL_REQUEST) {
  initiator_cid : 16,
  dest_controller_id : 8,
}

enum MoveChannelResponseResult : 16 {
  SUCCESS = 0x0000,
  PENDING = 0x0001,
  CONTROLLER_ID_NOT_SUPPORTED = 0x0002,
  NEW_CONTROLLER_ID_IS_SAME = 0x0003,
  CONFIGURATION_NOT_SUPPORTED = 0x0004,
  CHANNEL_COLLISION = 0x0005,
  CHANNEL_NOT_ALLOWED_TO_BE_MOVED = 0x0006,
}

packet MoveChannelResponse : Control (code = MOVE_CHANNEL_RESPONSE) {
  initiator_cid : 16,
  result : MoveChannelResponseResult,
}

enum MoveChannelConfirmationResult : 16 {
  SUCCESS = 0x0000,
  FAILURE = 0x0001,
}

packet MoveChannelConfirmationRequest : Control (code = MOVE_CHANNEL_CONFIRMATION_REQUEST) {
  initiator_cid : 16,
  result : MoveChannelConfirmationResult,
}

packet MoveChannelConfirmationResponse : Control (code = MOVE_CHANNEL_CONFIRMATION_RESPONSE) {
  initiator_cid : 16,
}

enum LeCommandCode : 8 {
  COMMAND_REJECT = 0x01,
  DISCONNECTION_REQUEST = 0x06,
  DISCONNECTION_RESPONSE = 0x07,
  CONNECTION_PARAMETER_UPDATE_REQUEST = 0x12,
  CONNECTION_PARAMETER_UPDATE_RESPONSE = 0x13,
  LE_CREDIT_BASED_CONNECTION_REQUEST = 0x14,
  LE_CREDIT_BASED_CONNECTION_RESPONSE = 0x15,
  LE_FLOW_CONTROL_CREDIT = 0x16,
}

packet LeControlFrame : BasicFrame (channel_id = 0x0005) {
  _payload_,
}

packet LeControl {
  code : LeCommandCode,
  identifier : 8, // Must be non-zero
  _size_(_payload_) : 16,
  _payload_,
}


packet LeCommandReject : LeControl (code = COMMAND_REJECT) {
  reason : CommandRejectReason,
  _payload_,
}

packet LeCommandRejectNotUnderstood : LeCommandReject (reason = COMMAND_NOT_UNDERSTOOD) {
}

packet LeCommandRejectMtuExceeded : LeCommandReject (reason = SIGNALING_MTU_EXCEEDED) {
  actual_mtu : 16,
}

packet LeCommandRejectInvalidCid : LeCommandReject (reason = INVALID_CID_IN_REQUEST) {
  local_channel : 16, // Relative to the sender of the CommandReject
  remote_channel : 16,
}

packet LeDisconnectionRequest : LeControl (code = DISCONNECTION_REQUEST) {
  destination_cid : 16,
  source_cid : 16,
}

packet LeDisconnectionResponse : LeControl (code = DISCONNECTION_RESPONSE) {
  destination_cid : 16,
  source_cid : 16,
}

packet ConnectionParameterUpdateRequest : LeControl (code = CONNECTION_PARAMETER_UPDATE_REQUEST) {
  interval_min : 16,
  interval_max : 16,
  slave_latency : 16,
  timeout_multiplier : 16,
}

enum ConnectionParameterUpdateResponseResult : 16 {
  ACCEPTED = 0,
  REJECTED = 1,
}

packet ConnectionParameterUpdateResponse : LeControl (code = CONNECTION_PARAMETER_UPDATE_RESPONSE) {
  result : ConnectionParameterUpdateResponseResult,
}

packet LeCreditBasedConnectionRequest : LeControl (code = LE_CREDIT_BASED_CONNECTION_REQUEST) {
  le_psm : 16, // 0x0001-0x007F Fixed, 0x0080-0x00FF Dynamic
  source_cid : 16,
  mtu : 16,
  mps : 16,
  initial_credits : 16,
}

enum LeCreditBasedConnectionResponseResult : 16 {
  SUCCESS = 0x0000,
  LE_PSM_NOT_SUPPORTED = 0x0002,
  NO_RESOURCES_AVAILABLE = 0x0004,
  INSUFFICIENT_AUTHENTICATION = 0x0005,
  INSUFFICIENT_AUTHORIZATION = 0x0006,
  INSUFFICIENT_ENCRYPTION_KEY_SIZE = 0x0007,
  INSUFFICIENT_ENCRYPTION = 0x0008,
  INVALID_SOURCE_CID = 0x0009,
  SOURCE_CID_ALREADY_ALLOCATED = 0x000A,
  UNACCEPTABLE_PARAMETERS = 0x000B,
}

packet LeCreditBasedConnectionResponse : LeControl (code = LE_CREDIT_BASED_CONNECTION_RESPONSE) {
  destination_cid : 16,
  mtu : 16,
  mps : 16,
  initial_credits : 16,
  result : LeCreditBasedConnectionResponseResult,
}

packet LeFlowControlCredit : LeControl (code = LE_FLOW_CONTROL_CREDIT) {
  cid : 16, // Receiver's destination CID
  credits : 16,
}