b6cdf10310
We can get rid of the view pool for SDU segments :) We have to make the code slightly more complex :'( The basic idea is always giving the original SDU buffer to `conn.c` for it to pull ACL fragments from. In order to do this, we need to add the PDU headers just-in-time. `bt_l2cap_send_pdu()` does not add them before putting the PDU on the queue anymore. They are added by `l2cap_data_pull()` right before the data leaves `l2cap.c` for `conn.c`. We also have to inform `conn.c` "out of band" of the real L2CAP PDU size so it doesn't fragment across segment boundaries. This oob is the new `length` parameter to the `.pull()` method. This is the added complexity mentioned above. Since SDU segmentation concerns only LE-L2CAP, ISO and Classic L2CAP don't need this extra logic. Signed-off-by: Jonathan Rico <jonathan.rico@nordicsemi.no>
665 lines
23 KiB
C
665 lines
23 KiB
C
/** @file
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* @brief Bluetooth L2CAP handling
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*/
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/*
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* Copyright (c) 2015-2016 Intel Corporation
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* Copyright (c) 2023 Nordic Semiconductor
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#ifndef ZEPHYR_INCLUDE_BLUETOOTH_L2CAP_H_
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#define ZEPHYR_INCLUDE_BLUETOOTH_L2CAP_H_
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/**
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* @brief L2CAP
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* @defgroup bt_l2cap L2CAP
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* @ingroup bluetooth
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* @{
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*/
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#include <sys/types.h>
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#include <zephyr/sys/atomic.h>
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#include <zephyr/bluetooth/buf.h>
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#include <zephyr/bluetooth/conn.h>
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#include <zephyr/bluetooth/hci.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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/** L2CAP PDU header size, used for buffer size calculations */
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#define BT_L2CAP_HDR_SIZE 4
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/** Maximum Transmission Unit (MTU) for an outgoing L2CAP PDU. */
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#define BT_L2CAP_TX_MTU (CONFIG_BT_L2CAP_TX_MTU)
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/** Maximum Transmission Unit (MTU) for an incoming L2CAP PDU. */
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#define BT_L2CAP_RX_MTU (CONFIG_BT_BUF_ACL_RX_SIZE - BT_L2CAP_HDR_SIZE)
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/** @brief Helper to calculate needed buffer size for L2CAP PDUs.
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* Useful for creating buffer pools.
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*
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* @param mtu Needed L2CAP PDU MTU.
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*
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* @return Needed buffer size to match the requested L2CAP PDU MTU.
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*/
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#define BT_L2CAP_BUF_SIZE(mtu) BT_BUF_ACL_SIZE(BT_L2CAP_HDR_SIZE + (mtu))
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/** L2CAP SDU header size, used for buffer size calculations */
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#define BT_L2CAP_SDU_HDR_SIZE 2
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/** @brief Maximum Transmission Unit for an unsegmented outgoing L2CAP SDU.
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*
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* The Maximum Transmission Unit for an outgoing L2CAP SDU when sent without
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* segmentation, i.e. a single L2CAP SDU will fit inside a single L2CAP PDU.
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*
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* The MTU for outgoing L2CAP SDUs with segmentation is defined by the
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* size of the application buffer pool.
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*/
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#define BT_L2CAP_SDU_TX_MTU (BT_L2CAP_TX_MTU - BT_L2CAP_SDU_HDR_SIZE)
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/** @brief Maximum Transmission Unit for an unsegmented incoming L2CAP SDU.
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*
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* The Maximum Transmission Unit for an incoming L2CAP SDU when sent without
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* segmentation, i.e. a single L2CAP SDU will fit inside a single L2CAP PDU.
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*
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* The MTU for incoming L2CAP SDUs with segmentation is defined by the
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* size of the application buffer pool. The application will have to define
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* an alloc_buf callback for the channel in order to support receiving
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* segmented L2CAP SDUs.
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*/
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#define BT_L2CAP_SDU_RX_MTU (BT_L2CAP_RX_MTU - BT_L2CAP_SDU_HDR_SIZE)
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/**
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*
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* @brief Helper to calculate needed buffer size for L2CAP SDUs.
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* Useful for creating buffer pools.
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*
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* @param mtu Required BT_L2CAP_*_SDU.
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*
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* @return Needed buffer size to match the requested L2CAP SDU MTU.
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*/
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#define BT_L2CAP_SDU_BUF_SIZE(mtu) BT_L2CAP_BUF_SIZE(BT_L2CAP_SDU_HDR_SIZE + (mtu))
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struct bt_l2cap_chan;
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/** @typedef bt_l2cap_chan_destroy_t
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* @brief Channel destroy callback
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*
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* @param chan Channel object.
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*/
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typedef void (*bt_l2cap_chan_destroy_t)(struct bt_l2cap_chan *chan);
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/** @brief Life-span states of L2CAP CoC channel.
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*
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* Used only by internal APIs dealing with setting channel to proper state
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* depending on operational context.
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*
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* A channel enters the @ref BT_L2CAP_CONNECTING state upon @ref
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* bt_l2cap_chan_connect, @ref bt_l2cap_ecred_chan_connect or upon returning
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* from @ref bt_l2cap_server.accept.
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*
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* When a channel leaves the @ref BT_L2CAP_CONNECTING state, @ref
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* bt_l2cap_chan_ops.connected is called.
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*/
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typedef enum bt_l2cap_chan_state {
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/** Channel disconnected */
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BT_L2CAP_DISCONNECTED,
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/** Channel in connecting state */
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BT_L2CAP_CONNECTING,
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/** Channel in config state, BR/EDR specific */
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BT_L2CAP_CONFIG,
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/** Channel ready for upper layer traffic on it */
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BT_L2CAP_CONNECTED,
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/** Channel in disconnecting state */
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BT_L2CAP_DISCONNECTING,
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} __packed bt_l2cap_chan_state_t;
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/** @brief Status of L2CAP channel. */
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typedef enum bt_l2cap_chan_status {
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/** Channel can send at least one PDU */
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BT_L2CAP_STATUS_OUT,
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/** @brief Channel shutdown status
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*
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* Once this status is notified it means the channel will no longer be
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* able to transmit or receive data.
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*/
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BT_L2CAP_STATUS_SHUTDOWN,
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/** @brief Channel encryption pending status */
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BT_L2CAP_STATUS_ENCRYPT_PENDING,
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/* Total number of status - must be at the end of the enum */
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BT_L2CAP_NUM_STATUS,
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} __packed bt_l2cap_chan_status_t;
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/** @brief L2CAP Channel structure. */
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struct bt_l2cap_chan {
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/** Channel connection reference */
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struct bt_conn *conn;
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/** Channel operations reference */
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const struct bt_l2cap_chan_ops *ops;
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sys_snode_t node;
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bt_l2cap_chan_destroy_t destroy;
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ATOMIC_DEFINE(status, BT_L2CAP_NUM_STATUS);
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};
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/** @brief LE L2CAP Endpoint structure. */
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struct bt_l2cap_le_endpoint {
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/** Endpoint Channel Identifier (CID) */
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uint16_t cid;
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/** Endpoint Maximum Transmission Unit */
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uint16_t mtu;
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/** Endpoint Maximum PDU payload Size */
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uint16_t mps;
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/** Endpoint credits */
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atomic_t credits;
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};
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/** @brief LE L2CAP Channel structure. */
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struct bt_l2cap_le_chan {
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/** Common L2CAP channel reference object */
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struct bt_l2cap_chan chan;
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/** @brief Channel Receiving Endpoint.
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*
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* If the application has set an alloc_buf channel callback for the
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* channel to support receiving segmented L2CAP SDUs the application
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* should initialize the MTU of the Receiving Endpoint. Otherwise the
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* MTU of the receiving endpoint will be initialized to
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* @ref BT_L2CAP_SDU_RX_MTU by the stack.
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*
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* This is the source of the MTU, MPS and credit values when sending
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* L2CAP_LE_CREDIT_BASED_CONNECTION_REQ/RSP and
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* L2CAP_CONFIGURATION_REQ.
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*/
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struct bt_l2cap_le_endpoint rx;
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/** Pending RX MTU on ECFC reconfigure, used internally by stack */
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uint16_t pending_rx_mtu;
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/** Channel Transmission Endpoint.
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*
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* This is an image of the remote's rx.
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*
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* The MTU and MPS is controlled by the remote by
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* L2CAP_LE_CREDIT_BASED_CONNECTION_REQ/RSP or L2CAP_CONFIGURATION_REQ.
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*/
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struct bt_l2cap_le_endpoint tx;
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/** Channel Transmission queue (for SDUs) */
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struct k_fifo tx_queue;
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#if defined(CONFIG_BT_L2CAP_DYNAMIC_CHANNEL)
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/** Segment SDU packet from upper layer */
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struct net_buf *_sdu;
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uint16_t _sdu_len;
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#if defined(CONFIG_BT_L2CAP_SEG_RECV)
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uint16_t _sdu_len_done;
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#endif /* CONFIG_BT_L2CAP_SEG_RECV */
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struct k_work rx_work;
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struct k_fifo rx_queue;
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bt_l2cap_chan_state_t state;
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/** Remote PSM to be connected */
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uint16_t psm;
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/** Helps match request context during CoC */
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uint8_t ident;
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bt_security_t required_sec_level;
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/* Response Timeout eXpired (RTX) timer */
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struct k_work_delayable rtx_work;
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struct k_work_sync rtx_sync;
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#endif
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/** @internal To be used with @ref bt_conn.upper_data_ready */
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sys_snode_t _pdu_ready;
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/** @internal To be used with @ref bt_conn.upper_data_ready */
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atomic_t _pdu_ready_lock;
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/** @internal Holds the length of the current PDU/segment */
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size_t _pdu_remaining;
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};
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/**
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* @brief Helper macro getting container object of type bt_l2cap_le_chan
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* address having the same container chan member address as object in question.
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*
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* @param _ch Address of object of bt_l2cap_chan type
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*
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* @return Address of in memory bt_l2cap_le_chan object type containing
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* the address of in question object.
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*/
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#define BT_L2CAP_LE_CHAN(_ch) CONTAINER_OF(_ch, struct bt_l2cap_le_chan, chan)
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/** @brief BREDR L2CAP Endpoint structure. */
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struct bt_l2cap_br_endpoint {
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/** Endpoint Channel Identifier (CID) */
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uint16_t cid;
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/** Endpoint Maximum Transmission Unit */
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uint16_t mtu;
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};
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/** @brief BREDR L2CAP Channel structure. */
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struct bt_l2cap_br_chan {
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/** Common L2CAP channel reference object */
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struct bt_l2cap_chan chan;
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/** Channel Receiving Endpoint */
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struct bt_l2cap_br_endpoint rx;
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/** Channel Transmission Endpoint */
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struct bt_l2cap_br_endpoint tx;
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/* For internal use only */
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atomic_t flags[1];
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bt_l2cap_chan_state_t state;
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/** Remote PSM to be connected */
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uint16_t psm;
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/** Helps match request context during CoC */
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uint8_t ident;
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bt_security_t required_sec_level;
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/* Response Timeout eXpired (RTX) timer */
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struct k_work_delayable rtx_work;
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struct k_work_sync rtx_sync;
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/** @internal To be used with @ref bt_conn.upper_data_ready */
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sys_snode_t _pdu_ready;
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/** @internal To be used with @ref bt_conn.upper_data_ready */
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atomic_t _pdu_ready_lock;
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/** @internal Queue of net bufs not yet sent to lower layer */
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struct k_fifo _pdu_tx_queue;
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};
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/** @brief L2CAP Channel operations structure. */
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struct bt_l2cap_chan_ops {
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/** @brief Channel connected callback
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*
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* If this callback is provided it will be called whenever the
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* connection completes.
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*
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* @param chan The channel that has been connected
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*/
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void (*connected)(struct bt_l2cap_chan *chan);
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/** @brief Channel disconnected callback
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*
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* If this callback is provided it will be called whenever the
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* channel is disconnected, including when a connection gets
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* rejected.
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*
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* @param chan The channel that has been Disconnected
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*/
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void (*disconnected)(struct bt_l2cap_chan *chan);
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/** @brief Channel encrypt_change callback
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*
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* If this callback is provided it will be called whenever the
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* security level changed (indirectly link encryption done) or
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* authentication procedure fails. In both cases security initiator
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* and responder got the final status (HCI status) passed by
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* related to encryption and authentication events from local host's
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* controller.
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*
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* @param chan The channel which has made encryption status changed.
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* @param status HCI status of performed security procedure caused
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* by channel security requirements. The value is populated
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* by HCI layer and set to 0 when success and to non-zero (reference to
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* HCI Error Codes) when security/authentication failed.
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*/
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void (*encrypt_change)(struct bt_l2cap_chan *chan, uint8_t hci_status);
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/** @brief Channel alloc_seg callback
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*
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* If this callback is provided the channel will use it to allocate
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* buffers to store segments. This avoids wasting big SDU buffers with
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* potentially much smaller PDUs. If this callback is supplied, it must
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* return a valid buffer.
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*
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* @param chan The channel requesting a buffer.
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*
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* @return Allocated buffer.
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*/
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struct net_buf *(*alloc_seg)(struct bt_l2cap_chan *chan);
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/** @brief Channel alloc_buf callback
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*
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* If this callback is provided the channel will use it to allocate
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* buffers to store incoming data. Channels that requires segmentation
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* must set this callback.
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* If the application has not set a callback the L2CAP SDU MTU will be
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* truncated to @ref BT_L2CAP_SDU_RX_MTU.
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*
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* @param chan The channel requesting a buffer.
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*
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* @return Allocated buffer.
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*/
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struct net_buf *(*alloc_buf)(struct bt_l2cap_chan *chan);
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/** @brief Channel recv callback
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*
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* @param chan The channel receiving data.
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* @param buf Buffer containing incoming data.
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*
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* @return 0 in case of success or negative value in case of error.
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* @return -EINPROGRESS in case where user has to confirm once the data
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* has been processed by calling
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* @ref bt_l2cap_chan_recv_complete passing back
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* the buffer received with its original user_data
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* which contains the number of segments/credits
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* used by the packet.
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*/
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int (*recv)(struct bt_l2cap_chan *chan, struct net_buf *buf);
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/** @brief Channel sent callback
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*
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* This callback will be called once the controller marks the SDU
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* as completed. When the controller does so is implementation
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* dependent. It could be after the SDU is enqueued for transmission,
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* or after it is sent on air.
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*
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* @param chan The channel which has sent data.
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*/
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void (*sent)(struct bt_l2cap_chan *chan);
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/** @brief Channel status callback
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*
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* If this callback is provided it will be called whenever the
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* channel status changes.
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*
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* @param chan The channel which status changed
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* @param status The channel status
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*/
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void (*status)(struct bt_l2cap_chan *chan, atomic_t *status);
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/* @brief Channel released callback
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*
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* If this callback is set it is called when the stack has release all
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* references to the channel object.
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*/
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void (*released)(struct bt_l2cap_chan *chan);
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/** @brief Channel reconfigured callback
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*
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* If this callback is provided it will be called whenever peer or
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* local device requested reconfiguration. Application may check
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* updated MTU and MPS values by inspecting chan->le endpoints.
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*
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* @param chan The channel which was reconfigured
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*/
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void (*reconfigured)(struct bt_l2cap_chan *chan);
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#if defined(CONFIG_BT_L2CAP_SEG_RECV)
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/** @brief Handle L2CAP segments directly
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*
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* This is an alternative to @ref bt_l2cap_chan_ops.recv. They cannot
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* be used together.
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*
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* This is called immediately for each received segment.
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*
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* Unlike with @ref bt_l2cap_chan_ops.recv, flow control is explicit.
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* Each time this handler is invoked, the remote has permanently used
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* up one credit. Use @ref bt_l2cap_chan_give_credits to give credits.
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*
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* The start of an SDU is marked by `seg_offset == 0`. The end of an
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* SDU is marked by `seg_offset + seg->len == sdu_len`.
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*
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* The stack guarantees that:
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* - The sender had the credit.
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* - The SDU length does not exceed MTU.
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* - The segment length does not exceed MPS.
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*
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* Additionally, the L2CAP protocol is such that:
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* - Segments come in order.
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* - SDUs cannot be interleaved or aborted halfway.
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*
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* @note With this alternative API, the application is responsible for
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* setting the RX MTU and MPS. The MPS must not exceed @ref BT_L2CAP_RX_MTU.
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*
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* @param chan The receiving channel.
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* @param sdu_len Byte length of the SDU this segment is part of.
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* @param seg_offset The byte offset of this segment in the SDU.
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* @param seg The segment payload.
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*/
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void (*seg_recv)(struct bt_l2cap_chan *chan, size_t sdu_len,
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off_t seg_offset, struct net_buf_simple *seg);
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#endif /* CONFIG_BT_L2CAP_SEG_RECV */
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};
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/**
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* @brief Headroom needed for outgoing L2CAP PDUs.
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*/
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#define BT_L2CAP_CHAN_SEND_RESERVE (BT_L2CAP_BUF_SIZE(0))
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/**
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* @brief Headroom needed for outgoing L2CAP SDUs.
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*/
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#define BT_L2CAP_SDU_CHAN_SEND_RESERVE (BT_L2CAP_SDU_BUF_SIZE(0))
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/** @brief L2CAP Server structure. */
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struct bt_l2cap_server {
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/** @brief Server PSM.
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*
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* Possible values:
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* 0 A dynamic value will be auto-allocated when
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* bt_l2cap_server_register() is called.
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*
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* 0x0001-0x007f Standard, Bluetooth SIG-assigned fixed values.
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*
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* 0x0080-0x00ff Dynamically allocated. May be pre-set by the
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* application before server registration (not
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* recommended however), or auto-allocated by the
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* stack if the app gave 0 as the value.
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*/
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uint16_t psm;
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/** Required minimum security level */
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bt_security_t sec_level;
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/** @brief Server accept callback
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*
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* This callback is called whenever a new incoming connection requires
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* authorization.
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*
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* @param conn The connection that is requesting authorization
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* @param server Pointer to the server structure this callback relates to
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* @param chan Pointer to received the allocated channel
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*
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* @return 0 in case of success or negative value in case of error.
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* @return -ENOMEM if no available space for new channel.
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* @return -EACCES if application did not authorize the connection.
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* @return -EPERM if encryption key size is too short.
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*/
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int (*accept)(struct bt_conn *conn, struct bt_l2cap_server *server,
|
|
struct bt_l2cap_chan **chan);
|
|
|
|
sys_snode_t node;
|
|
};
|
|
|
|
/** @brief Register L2CAP server.
|
|
*
|
|
* Register L2CAP server for a PSM, each new connection is authorized using
|
|
* the accept() callback which in case of success shall allocate the channel
|
|
* structure to be used by the new connection.
|
|
*
|
|
* For fixed, SIG-assigned PSMs (in the range 0x0001-0x007f) the PSM should
|
|
* be assigned to server->psm before calling this API. For dynamic PSMs
|
|
* (in the range 0x0080-0x00ff) server->psm may be pre-set to a given value
|
|
* (this is however not recommended) or be left as 0, in which case upon
|
|
* return a newly allocated value will have been assigned to it. For
|
|
* dynamically allocated values the expectation is that it's exposed through
|
|
* a GATT service, and that's how L2CAP clients discover how to connect to
|
|
* the server.
|
|
*
|
|
* @param server Server structure.
|
|
*
|
|
* @return 0 in case of success or negative value in case of error.
|
|
*/
|
|
int bt_l2cap_server_register(struct bt_l2cap_server *server);
|
|
|
|
/** @brief Register L2CAP server on BR/EDR oriented connection.
|
|
*
|
|
* Register L2CAP server for a PSM, each new connection is authorized using
|
|
* the accept() callback which in case of success shall allocate the channel
|
|
* structure to be used by the new connection.
|
|
*
|
|
* @param server Server structure.
|
|
*
|
|
* @return 0 in case of success or negative value in case of error.
|
|
*/
|
|
int bt_l2cap_br_server_register(struct bt_l2cap_server *server);
|
|
|
|
/** @brief Connect Enhanced Credit Based L2CAP channels
|
|
*
|
|
* Connect up to 5 L2CAP channels by PSM, once the connection is completed
|
|
* each channel connected() callback will be called. If the connection is
|
|
* rejected disconnected() callback is called instead.
|
|
*
|
|
* @param conn Connection object.
|
|
* @param chans Array of channel objects.
|
|
* @param psm Channel PSM to connect to.
|
|
*
|
|
* @return 0 in case of success or negative value in case of error.
|
|
*/
|
|
int bt_l2cap_ecred_chan_connect(struct bt_conn *conn,
|
|
struct bt_l2cap_chan **chans, uint16_t psm);
|
|
|
|
/** @brief Reconfigure Enhanced Credit Based L2CAP channels
|
|
*
|
|
* Reconfigure up to 5 L2CAP channels. Channels must be from the same bt_conn.
|
|
* Once reconfiguration is completed each channel reconfigured() callback will
|
|
* be called. MTU cannot be decreased on any of provided channels.
|
|
*
|
|
* @param chans Array of channel objects. Null-terminated. Elements after the
|
|
* first 5 are silently ignored.
|
|
* @param mtu Channel MTU to reconfigure to.
|
|
*
|
|
* @return 0 in case of success or negative value in case of error.
|
|
*/
|
|
int bt_l2cap_ecred_chan_reconfigure(struct bt_l2cap_chan **chans, uint16_t mtu);
|
|
|
|
/** @brief Connect L2CAP channel
|
|
*
|
|
* Connect L2CAP channel by PSM, once the connection is completed channel
|
|
* connected() callback will be called. If the connection is rejected
|
|
* disconnected() callback is called instead.
|
|
* Channel object passed (over an address of it) as second parameter shouldn't
|
|
* be instantiated in application as standalone. Instead of, application should
|
|
* create transport dedicated L2CAP objects, i.e. type of bt_l2cap_le_chan for
|
|
* LE and/or type of bt_l2cap_br_chan for BR/EDR. Then pass to this API
|
|
* the location (address) of bt_l2cap_chan type object which is a member
|
|
* of both transport dedicated objects.
|
|
*
|
|
* @param conn Connection object.
|
|
* @param chan Channel object.
|
|
* @param psm Channel PSM to connect to.
|
|
*
|
|
* @return 0 in case of success or negative value in case of error.
|
|
*/
|
|
int bt_l2cap_chan_connect(struct bt_conn *conn, struct bt_l2cap_chan *chan,
|
|
uint16_t psm);
|
|
|
|
/** @brief Disconnect L2CAP channel
|
|
*
|
|
* Disconnect L2CAP channel, if the connection is pending it will be
|
|
* canceled and as a result the channel disconnected() callback is called.
|
|
* Regarding to input parameter, to get details see reference description
|
|
* to bt_l2cap_chan_connect() API above.
|
|
*
|
|
* @param chan Channel object.
|
|
*
|
|
* @return 0 in case of success or negative value in case of error.
|
|
*/
|
|
int bt_l2cap_chan_disconnect(struct bt_l2cap_chan *chan);
|
|
|
|
/** @brief Send data to L2CAP channel
|
|
*
|
|
* Send data from buffer to the channel. If credits are not available, buf will
|
|
* be queued and sent as and when credits are received from peer.
|
|
* Regarding to first input parameter, to get details see reference description
|
|
* to bt_l2cap_chan_connect() API above.
|
|
*
|
|
* Network buffer fragments (ie `buf->frags`) are not supported.
|
|
*
|
|
* When sending L2CAP data over an BR/EDR connection the application is sending
|
|
* L2CAP PDUs. The application is required to have reserved
|
|
* @ref BT_L2CAP_CHAN_SEND_RESERVE bytes in the buffer before sending.
|
|
* The application should use the BT_L2CAP_BUF_SIZE() helper to correctly
|
|
* size the buffers for the for the outgoing buffer pool.
|
|
*
|
|
* When sending L2CAP data over an LE connection the application is sending
|
|
* L2CAP SDUs. The application shall reserve
|
|
* @ref BT_L2CAP_SDU_CHAN_SEND_RESERVE bytes in the buffer before sending.
|
|
*
|
|
* The application can use the BT_L2CAP_SDU_BUF_SIZE() helper to correctly size
|
|
* the buffer to account for the reserved headroom.
|
|
*
|
|
* When segmenting an L2CAP SDU into L2CAP PDUs the stack will first attempt to
|
|
* allocate buffers from the channel's `alloc_seg` callback and will fallback
|
|
* on the stack's global buffer pool (sized
|
|
* @kconfig{CONFIG_BT_L2CAP_TX_BUF_COUNT}).
|
|
*
|
|
* @note Buffer ownership is transferred to the stack in case of success, in
|
|
* case of an error the caller retains the ownership of the buffer.
|
|
*
|
|
* @return 0 in case of success or negative value in case of error.
|
|
* @return -EINVAL if `buf` or `chan` is NULL.
|
|
* @return -EINVAL if `chan` is not either BR/EDR or LE credit-based.
|
|
* @return -EINVAL if buffer doesn't have enough bytes reserved to fit header.
|
|
* @return -EINVAL if buffer's reference counter != 1
|
|
* @return -EMSGSIZE if `buf` is larger than `chan`'s MTU.
|
|
* @return -ENOTCONN if underlying conn is disconnected.
|
|
* @return -ESHUTDOWN if L2CAP channel is disconnected.
|
|
* @return -other (from lower layers) if chan is BR/EDR.
|
|
*/
|
|
int bt_l2cap_chan_send(struct bt_l2cap_chan *chan, struct net_buf *buf);
|
|
|
|
/** @brief Give credits to the remote
|
|
*
|
|
* Only available for channels using @ref bt_l2cap_chan_ops.seg_recv.
|
|
* @kconfig{CONFIG_BT_L2CAP_SEG_RECV} must be enabled to make this function
|
|
* available.
|
|
*
|
|
* Each credit given allows the peer to send one segment.
|
|
*
|
|
* This function depends on a valid @p chan object. Make sure to
|
|
* default-initialize or memset @p chan when allocating or reusing it for new
|
|
* connections.
|
|
*
|
|
* Adding zero credits is not allowed.
|
|
*
|
|
* Credits can be given before entering the @ref BT_L2CAP_CONNECTING state.
|
|
* Doing so will adjust the 'initial credits' sent in the connection PDU.
|
|
*
|
|
* Must not be called while the channel is in @ref BT_L2CAP_CONNECTING state.
|
|
*
|
|
* @return 0 in case of success or negative value in case of error.
|
|
*/
|
|
int bt_l2cap_chan_give_credits(struct bt_l2cap_chan *chan, uint16_t additional_credits);
|
|
|
|
/** @brief Complete receiving L2CAP channel data
|
|
*
|
|
* Complete the reception of incoming data. This shall only be called if the
|
|
* channel recv callback has returned -EINPROGRESS to process some incoming
|
|
* data. The buffer shall contain the original user_data as that is used for
|
|
* storing the credits/segments used by the packet.
|
|
*
|
|
* @param chan Channel object.
|
|
* @param buf Buffer containing the data.
|
|
*
|
|
* @return 0 in case of success or negative value in case of error.
|
|
*/
|
|
int bt_l2cap_chan_recv_complete(struct bt_l2cap_chan *chan,
|
|
struct net_buf *buf);
|
|
|
|
#ifdef __cplusplus
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* @}
|
|
*/
|
|
|
|
#endif /* ZEPHYR_INCLUDE_BLUETOOTH_L2CAP_H_ */
|