5.3 KiB
L2CAP Events
L2CAP events and data packets are delivered to the packet handler specified by l2cap_register_service resp. l2cap_create_channel. Data packets have the L2CAP_DATA_PACKET packet type. L2CAP provides the following events:
-
L2CAP_EVENT_CHANNEL_OPENED - sent if channel establishment is done. Status not equal zero indicates an error. Possible errors: out of memory; connection terminated by local host, when the connection to remote device fails.
-
L2CAP_EVENT_CHANNEL_CLOSED - emitted when channel is closed. No status information is provided.
-
L2CAP_EVENT_INCOMING_CONNECTION - received when the connection is requested by remote. Connection accept and decline are performed with l2cap_accept_connection and l2cap_decline_connecti-on respectively.
-
L2CAP_EVENT_CREDITS - emitted when there is a chance to send a new L2CAP packet. BTstack does not buffer packets. Instead, it requires the application to retry sending if BTstack cannot deliver a packet to the Bluetooth module. In this case, the l2cap_send will return an error.
-
L2CAP_EVENT_SERVICE_REGISTERED - Status not equal zero indicates an error. Possible errors: service is already registered; MAX_NO_L2CAP_SERVICES (defined in config.h) already registered.
| Event | Event Code |
|---|---|
| L2CAP_EVENT_CHANNEL_OPENED | 0x70 |
| L2CAP_EVENT_CHANNEL_CLOSED | 0x71 |
| L2CAP_EVENT_INCOMING_CONNECTION | 0x72 |
| L2CAP_EVENT_CREDITS | 0x74 |
| L2CAP_EVENT_SERVICE_REGISTERED | 0x75 |
Table: L2CAP Events. {#tbl:l2capEvents}
L2CAP event paramaters, with size in bits:
- L2CAP_EVENT_CHANNEL_OPENED:
- event(8), len(8), status(8), address(48), handle(16), psm(16), local_cid(16), remote_cid(16), local_mtu(16), remote_mtu(16)
- L2CAP_EVENT_CHANNEL_CLOSED:
- event (8), len(8), channel(16)
- L2CAP_EVENT_INCOMING_CONNECTION:
- event(8), len(8), address(48), handle(16), psm (16), local_cid(16), remote_cid (16)
- L2CAP_EVENT_CREDITS:
- event(8), len(8), local_cid(16), credits(8)
- L2CAP_EVENT_SERVICE_REGISTERED:
- event(8), len(8), status(8), psm(16)
RFCOMM Events
All RFCOMM events and data packets are currently delivered to the packet handler specified by rfcomm_register_packet_handler. Data packets have the _DATA_PACKET packet type. Here is the list of events provided by RFCOMM:
-
RFCOMM_EVENT_INCOMING_CONNECTION - received when the connection is requested by remote. Connection accept and decline are performed with rfcomm_accept_connection and rfcomm_decline_connection respectively.
-
RFCOMM_EVENT_CHANNEL_CLOSED - emitted when channel is closed. No status information is provided.
-
RFCOMM_EVENT_OPEN_CHANNEL_COMPLETE - sent if channel establishment is done. Status not equal zero indicates an error. Possible errors: an L2CAP error, out of memory.
-
RFCOMM_EVENT_CREDITS - The application can resume sending when this even is received. See Section on RFCOMM credit-based flow-control for more.
-
RFCOMM_EVENT_SERVICE_REGISTERED - Status not equal zero indicates an error. Possible errors:
- service is already registered;
- MAX_NO_RFCOMM_SERVICES (defined in config.h) already registered.
| Event | Event Code |
|---|---|
| RFCOMM_EVENT_OPEN_CHANNEL_COMPLETE | 0x80 |
| RFCOMM_EVENT_CHANNEL_CLOSED | 0x81 |
| RFCOMM_EVENT_INCOMING_CONNECTION | 0x82 |
| RFCOMM_EVENT_CREDITS | 0x84 |
| RFCOMM_EVENT_SERVICE_REGISTERED | 0x85 |
Table: RFCOMM Events. {#tbl:rfcommEvents}
RFCOMM event paramaters, with size in bits:
- RFCOMM_EVENT_OPEN_CHANNEL_COMPLETE:
- event(8), len(8), status(8), address(48), handle(16), server_channel(8), rfcomm_cid(16), max_frame_size(16)
- RFCOMM_EVENT_CHANNEL_CLOSED:
- event(8), len(8), rfcomm_cid(16)
- RFCOMM_EVENT_INCOMING_CONNECTION:
- event(8), len(8), address(48), channel (8), rfcomm_cid(16)
- RFCOMM_EVENT_CREDITS:
- event(8), len(8), rfcomm_cid(16), credits(8)
- RFCOMM_EVENT_SERVICE_REGISTERED:
- event(8), len(8), status(8), rfcomm server channel_id(8)
Errors
| Error | Error Code |
|---|---|
| BTSTACK_MEMORY_ALLOC_FAILED | 0x56 |
| BTSTACK_ACL_BUFFERS_FULL | 0x57 |
| L2CAP_COMMAND_REJECT_REASON_COMMAND_NOT_UNDERSTOOD | 0x60 |
| L2CAP_COMMAND_REJECT_REASON_SIGNALING_MTU_EXCEEDED | 0x61 |
| L2CAP_COMMAND_REJECT_REASON_INVALID_CID_IN_REQUEST | 0x62 |
| L2CAP_CONNECTION_RESPONSE_RESULT_SUCCESSFUL | 0x63 |
| L2CAP_CONNECTION_RESPONSE_RESULT_PENDING | 0x64 |
| L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_PSM | 0x65 |
| L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_SECURITY | 0x66 |
| L2CAP_CONNECTION_RESPONSE_RESULT_REFUSED_RESOURCES | 0x65 |
| L2CAP_CONFIG_RESPONSE_RESULT_SUCCESSFUL | 0x66 |
| L2CAP_CONFIG_RESPONSE_RESULT_UNACCEPTABLE_PARAMS | 0x67 |
| L2CAP_CONFIG_RESPONSE_RESULT_REJECTED | 0x68 |
| L2CAP_CONFIG_RESPONSE_RESULT_UNKNOWN_OPTIONS | 0x69 |
| L2CAP_SERVICE_ALREADY_REGISTERED | 0x6a |
| RFCOMM_MULTIPLEXER_STOPPED | 0x70 |
| RFCOMM_CHANNEL_ALREADY_REGISTERED | 0x71 |
| RFCOMM_NO_OUTGOING_CREDITS | 0x72 |
| SDP_HANDLE_ALREADY_REGISTERED | 0x80 |
Table: Errors. {#tbl:errors}