#include <sys/types.h>
#include <bt/bt_defs.h>
Data Structures | |
| struct | bt_l2cap_acl_buffer_entry |
| Buffer entry for internal acl packet buffering. More... | |
| struct | bt_l2cap_acl_pkt |
| Represents one l2cap packet including the acl header. More... | |
| struct | bt_l2cap_bb_connection |
| struct | bt_l2cap_channel |
| This struct represents one l2cap channel. More... | |
| struct | bt_l2cap_pkt_buffer_entry |
| Buffer entry for internal l2cap packet buffering. More... | |
| struct | bt_l2cap_service |
| This struct represents one service. More... | |
| struct | bt_l2cap_signal |
| This struct contains the header fields of a l2cap signaling packet. More... | |
| struct | bt_l2cap_signal_buffer |
| Buffer entry for internal l2cap signal buffering. More... | |
| struct | bt_l2cap_stack |
| Represents one entity of the l2cap layer itself. More... | |
| struct | l2cap_echo_cmd |
Callback detail | |
| #define | BT_L2CAP_CON_ACTIVE 0x02 |
| #define | BT_L2CAP_CON_CB void (*con_cb) (u_char type, u_char detail, u_char service_nr, u_short channel_id, void *arg) |
| #define | BT_L2CAP_CON_PASSIVE 0x03 |
| #define | BT_L2CAP_DISCON_LINK_LOST 0x04 |
| #define | BT_L2CAP_RCV_CB void (*rcv_cb) (struct bt_l2cap_acl_pkt *pkt, u_char service_nr, u_short channel_id, void *arg) |
| #define | BT_L2CAP_UNKNOWN 0x01 |
| l2cap_echo_cmd | echo_cmd |
| bt_l2cap_stack * | l2cap_stack |
| bt_l2cap_signal | packed |
| bt_l2cap_acl_pkt | packed |
| bt_l2cap_channel * | _bt_l2cap_get_channel_from_channel_id (u_short channel_id) |
| u_char | _bt_l2cap_get_new_sigid (struct bt_l2cap_bb_connection *bb_con) |
| bt_l2cap_service * | _bt_l2cap_get_service_from_channel_id (u_short channel_id) |
| bt_l2cap_bb_connection * | _bt_l2cap_handle2baseband (bt_hci_con_handle_t con_handle) |
| u_char | bt_l2cap_clear_service (u_char service_nr) |
| This command clears a previosly registered service. | |
| void | bt_l2cap_complete_pkt (struct bt_l2cap_acl_pkt *pkt) |
| Informs the baseband that an packet can be freed (flow control). | |
| u_char | bt_l2cap_connect (u_char service_nr, bt_addr_t bt_addr, u_char page_scan_rep_mode, u_short clock_offset, u_short psm, u_short *channel_id) |
| This command will open a channel to a remote device. | |
| u_char | bt_l2cap_disconnect (u_short channel_id) |
| This command will close a previously opened connection. | |
| u_char | bt_l2cap_get_hci_connection_handle (u_short channel_id, bt_hci_con_handle_t *con_handle) |
| Queries the baseband connection handle an established channel. | |
| u_char | bt_l2cap_get_incomming_mtu (u_short channel_id, u_short *mtu) |
| Queries the incomming mtu of an established channel. | |
| u_char | bt_l2cap_get_local_cid (u_short channel_id, u_short *cid) |
| Queries the local cid of an established channel. | |
| u_char | bt_l2cap_get_outgoing_mtu (u_short channel_id, u_short *mtu) |
| Queries the outgoing mtu of an established channel. | |
| u_char | bt_l2cap_get_remote_cid (u_short channel_id, u_short *cid) |
| Queries the remote cid of an established channel. | |
| bt_l2cap_stack * | bt_l2cap_init (struct btstack *bt_stack, u_char nr_buffer, u_char max_channel, u_short pkt_types) |
| u_char | bt_l2cap_is_ch_open (u_short channel_id) |
| Checks if a channel_id is valid (the channel is opened). | |
| u_char | bt_l2cap_l2ping (bt_addr_t bt_addr, u_char *payload, u_short len, u_long *time) |
| Send a l2cap echo request to a specific device and queries the return time of the packet. | |
| u_char | bt_l2cap_register_service (u_short psm, u_char nr_buffer, u_short min_mtu, u_short max_mtu, BT_L2CAP_CON_CB, BT_L2CAP_RCV_CB, void *cb_arg) |
| This command registers a service (the next higher layer). | |
| u_long | bt_l2cap_send (u_short channel_id, struct bt_l2cap_acl_pkt *pkt, u_short len) |
| Sends data over a connected channel. | |
Defines | |
Header length defintions | |
| #define | BT_L2CAP_ACL_PKT_HDR_LEN (5 + HCI_ACL_DATA_PKT_HDR) |
| #define | BT_L2CAP_HEADER_LEN 4 |
| #define | BT_L2CAP_SIG_HEADER_LEN 4 |
ACL packet sizes for differen acl pkt types | |
| #define | BT_L2CAP_ACL_SIZE_DH1 28 |
| #define | BT_L2CAP_ACL_SIZE_DH3 185 |
| #define | BT_L2CAP_ACL_SIZE_DH5 341 |
| #define | BT_L2CAP_ACL_SIZE_DM1 18 |
| #define | BT_L2CAP_ACL_SIZE_DM3 123 |
| #define | BT_L2CAP_ACL_SIZE_DM5 226 |
Connection status infos | |
| #define | BT_L2CAP_AUTHENTICATION_PENDING 0x0001 |
| #define | BT_L2CAP_AUTHORIZATION_PENDING 0x0002 |
| #define | BT_L2CAP_NO_FURTHER_INFO 0x0000 |
Channel state codes (internal state machine) | |
| #define | BT_L2CAP_CH_CLOSED 0x01 |
| #define | BT_L2CAP_CH_CONFIG 0x04 |
| #define | BT_L2CAP_CH_NOT_ASSIGNED 0x00 |
| #define | BT_L2CAP_CH_OPEN 0x06 |
| #define | BT_L2CAP_CH_W4_L2CAP_CONNECT 0x03 |
| #define | BT_L2CAP_CH_W4_L2CAP_CONNECT_RSP 0x02 |
| #define | BT_L2CAP_CH_W4_L2CAP_DISCONNECT_RSP 0x07 |
Some defines for error or not initialized conditions | |
| #define | BT_L2CAP_CHANNEL_INFO_SIZE (sizeof(struct bt_l2cap_acl_buffer_entry *)) |
| #define | BT_L2CAP_CHNR_INVALID 0xFF |
| #define | BT_L2CAP_HANDLE_INVALID 0x00 |
| #define | BT_L2CAP_MAX_CHANNELS 0xFE |
| #define | BT_L2CAP_MAX_SERVICES 16 |
| #define | BT_L2CAP_SERVICENR_INVALID 0xFF |
Predefined channel identifiers (CIDs) | |
| #define | BT_L2CAP_CID_CONNECTIONLESS 0x0002 |
| #define | BT_L2CAP_CID_MAX 0xFFFF |
| #define | BT_L2CAP_CID_SERVICES 0xFF00 |
| #define | BT_L2CAP_CID_SIG 0x0001 |
| #define | BT_L2CAP_CID_USER 0x0040 |
Connection request results (SIG_CON) | |
| #define | BT_L2CAP_CON_PENDING 0x0001 |
| #define | BT_L2CAP_CON_PSM_NOT_SUPPORTED 0x0002 |
| #define | BT_L2CAP_CON_REJ_NO_RESSOURCE 0x0004 |
| #define | BT_L2CAP_CON_SECURITY_BLOCK 0x0003 |
| #define | BT_L2CAP_CON_SUCCESS 0x0000 |
Configuration request options (SIG_CONF) | |
| #define | BT_L2CAP_CONF_OPT_FLUSH 0x02 |
| #define | BT_L2CAP_CONF_OPT_MTU 0x01 |
| #define | BT_L2CAP_CONF_OPT_NONE 0x00 |
| #define | BT_L2CAP_CONF_OPT_QOS 0x03 |
| #define | BT_L2CAP_CONF_OPT_RTR_FLOW 0x04 |
Configuration request results (SIG_CONF) | |
| #define | BT_L2CAP_CONF_REJECT 0x0002 |
| #define | BT_L2CAP_CONF_SUCCESS 0x0000 |
| #define | BT_L2CAP_CONF_UNACCAPTABLE 0x0001 |
| #define | BT_L2CAP_CONF_UNKNOWN_OPTIONS 0x0003 |
Callback types | |
| #define | BT_L2CAP_CONNECT 0x01 |
| #define | BT_L2CAP_DISCONNECT 0x02 |
Error codes | |
| #define | BT_L2CAP_ERR_BB_CON_FAILED 0x02 |
| #define | BT_L2CAP_ERR_CH_CONFIG 0x15 |
| #define | BT_L2CAP_ERR_CH_NOT_OPEN 0x06 |
| #define | BT_L2CAP_ERR_CMD_PENDING 0x07 |
| #define | BT_L2CAP_ERR_CON_PENDING 0x12 |
| #define | BT_L2CAP_ERR_DATASIZE 0x0A |
| #define | BT_L2CAP_ERR_IN_USE 0x08 |
| #define | BT_L2CAP_ERR_INVALID_CID 0x05 |
| #define | BT_L2CAP_ERR_INVALID_HANDLE 0x09 |
| #define | BT_L2CAP_ERR_INVALID_PSM 0x01 |
| #define | BT_L2CAP_ERR_NO_RESSOURCE 0x03 |
| #define | BT_L2CAP_ERR_OUT_OF_MEMORY 0x0B |
| #define | BT_L2CAP_ERR_PAYLOAD_LEN 0x11 |
| #define | BT_L2CAP_ERR_PING_PENDING 0x10 |
| #define | BT_L2CAP_ERR_PSM_NOT_SUPPORTED 0x13 |
| #define | BT_L2CAP_ERR_SECURITY_BLOCK 0x14 |
| #define | BT_L2CAP_ERR_SUCCESS 0x00 |
| #define | BT_L2CAP_ERR_TIMEOUT 0x04 |
Flags for channel status | |
| #define | BT_L2CAP_FLAG_CMD_MASK 0x0F |
| #define | BT_L2CAP_FLAG_CON_RSP 0x08 |
| #define | BT_L2CAP_FLAG_CONF_REQ 0x02 |
| #define | BT_L2CAP_FLAG_CONF_RSP 0x04 |
| #define | BT_L2CAP_FLAG_DISC_RSP 0x01 |
| #define | BT_L2CAP_FLAG_INITIATOR 0x80 |
| #define | BT_L2CAP_FLAG_WAS_CON 0x20 |
Types of information packets (SIG_INFO) | |
| #define | BT_L2CAP_INFO_CONLESS_MTU 0x0001 |
| #define | BT_L2CAP_INFO_EXT_FEATURES 0x0002 |
| #define | BT_L2CAP_INFO_NOT_SUPPORTED 0x0001 |
| #define | BT_L2CAP_INFO_SUCCESS 0x0000 |
MTU definitions | |
| #define | BT_L2CAP_MIN_MTU 48 |
| #define | BT_L2CAP_MTU_DEFAULT 672 |
Flow control and retransmission modes (SIG_CONF) | |
| #define | BT_L2CAP_MODE_BASIC 0x00 |
| #define | BT_L2CAP_MODE_FLOW 0x02 |
| #define | BT_L2CAP_MODE_RTR 0x01 |
Some known predifined PSMs | |
| #define | BT_L2CAP_PSM_BNEP 0x000F |
| #define | BT_L2CAP_PSM_INVALID 0x0000 |
| #define | BT_L2CAP_PSM_RFCOMM 0x0003 |
Quality of service options (SIG_CONF) | |
| #define | BT_L2CAP_QOS_BEST_EFFORT 0x01 |
| #define | BT_L2CAP_QOS_GUARANTEED 0x02 |
| #define | BT_L2CAP_QOS_NO_TRAFFIC 0x00 |
Reject reasons of a signalling command | |
| #define | BT_L2CAP_REJ_CMD_NOT_UNDERSTOOD 0x0000 |
| #define | BT_L2CAP_REJ_INVALID_CID 0x0002 |
| #define | BT_L2CAP_REJ_MTU_EXCEEDED 0x0001 |
Signalling codes for l2cap signaling packets | |
| #define | BT_L2CAP_SIG_CMD_REJ 0x01 |
| #define | BT_L2CAP_SIG_CON_REQ 0x02 |
| #define | BT_L2CAP_SIG_CON_RSP 0x03 |
| #define | BT_L2CAP_SIG_CONF_REQ 0x04 |
| #define | BT_L2CAP_SIG_CONF_RSP 0x05 |
| #define | BT_L2CAP_SIG_DISC_REQ 0x06 |
| #define | BT_L2CAP_SIG_DISC_RSP 0x07 |
| #define | BT_L2CAP_SIG_ECHO_REQ 0x08 |
| #define | BT_L2CAP_SIG_ECHO_RSP 0x09 |
| #define | BT_L2CAP_SIG_INFO_REQ 0x0a |
| #define | BT_L2CAP_SIG_INFO_RSP 0x0b |
Signalling timeouts in ms | |
| #define | BT_L2CAP_SIGNAL_TIMEOUT 5000 |
| #define | BT_L2CAP_SIGNAL_TIMEOUT_PENDING 60000 |
| #define BT_L2CAP_ACL_PKT_HDR_LEN (5 + HCI_ACL_DATA_PKT_HDR) |
Header length of an acl packet
| #define BT_L2CAP_CON_CB void (*con_cb) (u_char type, u_char detail, u_char service_nr, u_short channel_id, void *arg) |
Connection callback definition
This callback will be called whenever a l2cap connection is established or closed on a specific PSM. This is specified by the service registration routine.
| type | Type of callback: BT_L2CAP_CONNECT or BT_L2CAP_DISCONNECT | |
| detail | Information about the callbacks reason. Possible values: BT_L2CAP_UNKNOWN BT_L2CAP_CON_ACTIVE BT_L2CAP_CON_PASSIVE BT_L2CAP_DISCON_LINK_LOST | |
| service_nr | Number of the service this callback is assigned to | |
| channel_id | Channel ID of the l2cap channel this callback is assigned to | |
| arg | Pointer to the callback argument. (see register service) |
| #define BT_L2CAP_HEADER_LEN 4 |
Header length of a l2cap packet
| #define BT_L2CAP_MAX_CHANNELS 0xFE |
Defines maximum nr of services the l2cap layer can handle. A service is the logical endpoint that will receive and handle the data fom the l2cap connection. In other words the next higher layer (i.e. rfcomm)
Not more than 5 bits as they are used to encode the service nr in the unique l2cap id
| #define BT_L2CAP_MTU_DEFAULT 672 |
Maximum transmission unit default values
| #define BT_L2CAP_RCV_CB void (*rcv_cb) (struct bt_l2cap_acl_pkt *pkt, u_char service_nr, u_short channel_id, void *arg) |
Receive callback definition
This callback will be called whenever any user data is received by the l2cap layer on a specific PSM. This is specified by the service registration routine.
| pkt | Pointer to the reveiced acl packet | |
| service_nr | Number of the service this callback is assigned to | |
| channel_id | Channel ID of the l2cap channel this callback is assigned to | |
| arg | Pointer to the callback argument. (see register service) |
| #define BT_L2CAP_SIG_HEADER_LEN 4 |
Header length of a l2cap signaling packet
This command clears a previosly registered service.
After calling this command, the service is no longer registered. The service may not be in use.
| service_nr | Number of the service to be cleared |
| void bt_l2cap_complete_pkt | ( | struct bt_l2cap_acl_pkt * | pkt | ) |
Informs the baseband that an packet can be freed (flow control).
This function is used for flow control reasons. Every packet received by a service needs to be completed with this function. This function will inform the baseband that the reserved buffer can be cleared and will also clear l2cap internal buffers. If the packets won't be completed the baseband will stop receiving any more packets after The internal buffer runs full.
| pkt | l2cap packet to be completed |
| u_char bt_l2cap_connect | ( | u_char | service_nr, | |
| bt_addr_t | bt_addr, | |||
| u_char | page_scan_rep_mode, | |||
| u_short | clock_offset, | |||
| u_short | psm, | |||
| u_short * | channel_id | |||
| ) |
This command will open a channel to a remote device.
Opening a channel will connect a waiting service with the specified PSM of the remote device. If no baseband connection is yet established, a baseband connection will be established first. After successfull connection the data can be transferred.
Uppler layers will be informed by a connection callback
| service_nr | Number of the service to be connected to the remote device | |
| bt_addr | Bluetooth address of the remote device | |
| page_scan_rep_mode | Page scan mode (found during inquiry) (pass 0 if unknown) | |
| clock_offset | Offset to this device (found during inquiry). pass 0 if unknown | |
| psm | PSM of the connection endpoint | |
| channel_id | of new connection is stored here, if not null |
This command will close a previously opened connection.
After closing the channel no more data can be transfered. Uppler layers will be informed by a connection callback
| channel_id | ID of the channel to be closed. Will be passed by the connection callback. |
| u_char bt_l2cap_get_hci_connection_handle | ( | u_short | channel_id, | |
| bt_hci_con_handle_t * | con_handle | |||
| ) |
Queries the baseband connection handle an established channel.
| channel_id | ID of the channel | |
| con_handle | Baseband connection handle of the channel (call by reference) |
Queries the incomming mtu of an established channel.
| channel_id | ID of the channel | |
| mtu | Incomming MTU of the channel (call by reference) |
Queries the local cid of an established channel.
| channel_id | ID of the channel | |
| cid | Local CID of the channel (call by reference) |
Queries the outgoing mtu of an established channel.
| channel_id | ID of the channel | |
| mtu | Outgoing MTU of the channel (call by reference) |
Queries the remote cid of an established channel.
| channel_id | ID of the channel | |
| cid | Remote CID of the channel (call by reference) |
| struct bt_l2cap_stack* bt_l2cap_init | ( | struct btstack * | bt_stack, | |
| u_char | nr_buffer, | |||
| u_char | max_channel, | |||
| u_short | pkt_types | |||
| ) |
Initializes the l2cap stack.
| bt_stack | Pointer to btstack | |
| nr_buffer | Number of receive-buffer for l2cap packets | |
| max_channel | Maximum number of channels that can be used over one bb connection | |
| pkt_types | Bitmask of the acl packet types allowed. Example: BT_HCI_PACKET_TYPE_DM1 | BT_HCI_PACKET_TYPE_DH1 | BT_HCI_PACKET_TYPE_DM3 | BT_HCI_PACKET_TYPE_DH3 |
Checks if a channel_id is valid (the channel is opened).
Send a l2cap echo request to a specific device and queries the return time of the packet.
| bt_addr | Bluetooth address of the remote device | |
| payload | Payload to be send with the echo request | |
| len | Length of the payload (my not be larger than one acl packet) | |
| time | returns the return time of the packet (call by reference) |
| u_char bt_l2cap_register_service | ( | u_short | psm, | |
| u_char | nr_buffer, | |||
| u_short | min_mtu, | |||
| u_short | max_mtu, | |||
| BT_L2CAP_CON_CB | , | |||
| BT_L2CAP_RCV_CB | , | |||
| void * | cb_arg | |||
| ) |
This command registers a service (the next higher layer).
A service is the logical endpoint that will receive and handle the data fom the l2cap connection. In other words the next higher layer (i.e. rfcomm)
Changed MTU handling: Now we only have to define a minimum MTU the opposite device has to accept for this service. Our maximum MTU is given as the stacks max_mtu
| psm | The PSM the service will use | |
| nr_buffer | Number of l2cap packet buffers that should be reserved for this service Note: The service must be able to handle nr_buffer + number of acl buffers given on l2cap initialisation l2cap packets before one packet is freed. So always keep in mind to reserve enough buffers in your service. See bt_rfcomm for example | |
| min_mtu | Minimum MTU value that the opposite device has to accept | |
| max_mtu | Maximum MTU value our service will use | |
| BT_L2CAP_CON_CB | Connection callback. Will be called if the datalink connection to this service is established or closed. | |
| BT_L2CAP_RCV_CB | Receive callback. Will be called whenever data is received on an established datalink | |
| cb_arg | Pointer to a optional callback argument |
| u_long bt_l2cap_send | ( | u_short | channel_id, | |
| struct bt_l2cap_acl_pkt * | pkt, | |||
| u_short | len | |||
| ) |
Sends data over a connected channel.
| channel_id | ID of the channel | |
| pkt | l2cap packet to be send. Fillin only the payload, header will be added by the function. | |
| len | Length of the payload (may not be larger than the outgoing mtu of the channel |
1.5.1