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pigweed / third_party / github / zephyrproject-rtos / zephyr / be48697fa2781f629217f637fd95e78df259e3af / . / subsys / bluetooth / host / att.c
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/* att.c - Attribute protocol handling */
/*
* Copyright (c) 2015-2016 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/kernel.h>
#include <string.h>
#include <errno.h>
#include <stdbool.h>
#include <zephyr/sys/atomic.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/sys/util.h>
#include <zephyr/bluetooth/hci.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/uuid.h>
#include <zephyr/bluetooth/att.h>
#include <zephyr/bluetooth/gatt.h>
#include <zephyr/drivers/bluetooth/hci_driver.h>
#include "common/bt_str.h"
#include "hci_core.h"
#include "conn_internal.h"
#include "l2cap_internal.h"
#include "smp.h"
#include "att_internal.h"
#include "gatt_internal.h"
#define LOG_LEVEL CONFIG_BT_ATT_LOG_LEVEL
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(bt_att);
#define ATT_CHAN(_ch) CONTAINER_OF(_ch, struct bt_att_chan, chan.chan)
#define ATT_REQ(_node) CONTAINER_OF(_node, struct bt_att_req, node)
#define ATT_CMD_MASK 0x40
#if defined(CONFIG_BT_EATT)
#define ATT_CHAN_MAX (CONFIG_BT_EATT_MAX + 1)
#else
#define ATT_CHAN_MAX 1
#endif /* CONFIG_BT_EATT */
typedef enum __packed {
ATT_COMMAND,
ATT_REQUEST,
ATT_RESPONSE,
ATT_NOTIFICATION,
ATT_CONFIRMATION,
ATT_INDICATION,
ATT_UNKNOWN,
} att_type_t;
static att_type_t att_op_get_type(uint8_t op);
#if CONFIG_BT_ATT_PREPARE_COUNT > 0
struct bt_attr_data {
uint16_t handle;
uint16_t offset;
};
/* Pool for incoming ATT packets */
NET_BUF_POOL_DEFINE(prep_pool, CONFIG_BT_ATT_PREPARE_COUNT, BT_ATT_BUF_SIZE,
sizeof(struct bt_attr_data), NULL);
#endif /* CONFIG_BT_ATT_PREPARE_COUNT */
K_MEM_SLAB_DEFINE(req_slab, sizeof(struct bt_att_req),
CONFIG_BT_ATT_TX_COUNT, __alignof__(struct bt_att_req));
enum {
ATT_CONNECTED,
ATT_ENHANCED,
ATT_PENDING_SENT,
ATT_OUT_OF_SYNC_SENT,
/* Total number of flags - must be at the end of the enum */
ATT_NUM_FLAGS,
};
struct bt_att_tx_meta_data;
typedef void (*bt_att_tx_cb_t)(struct bt_conn *conn,
struct bt_att_tx_meta_data *user_data);
struct bt_att_tx_meta_data {
int err;
uint8_t opcode;
uint16_t attr_count;
struct bt_att_chan *att_chan;
bt_gatt_complete_func_t func;
void *user_data;
enum bt_att_chan_opt chan_opt;
};
struct bt_att_tx_meta {
struct bt_att_tx_meta_data *data;
};
/* ATT channel specific data */
struct bt_att_chan {
/* Connection this channel is associated with */
struct bt_att *att;
struct bt_l2cap_le_chan chan;
ATOMIC_DEFINE(flags, ATT_NUM_FLAGS);
struct bt_att_req *req;
struct k_fifo tx_queue;
struct k_work_delayable timeout_work;
sys_snode_t node;
};
static bool bt_att_is_enhanced(struct bt_att_chan *chan)
{
/* Optimization. */
if (!IS_ENABLED(CONFIG_BT_EATT)) {
return false;
}
return atomic_test_bit(chan->flags, ATT_ENHANCED);
}
static uint16_t bt_att_mtu(struct bt_att_chan *chan)
{
/* Core v5.3 Vol 3 Part F 3.4.2:
*
* The server and client shall set ATT_MTU to the minimum of the
* Client Rx MTU and the Server Rx MTU.
*/
return MIN(chan->chan.rx.mtu, chan->chan.tx.mtu);
}
/* Descriptor of application-specific authorization callbacks that are used
* with the CONFIG_BT_GATT_AUTHORIZATION_CUSTOM Kconfig enabled.
*/
const static struct bt_gatt_authorization_cb *authorization_cb;
/* ATT connection specific data */
struct bt_att {
struct bt_conn *conn;
/* Shared request queue */
sys_slist_t reqs;
struct k_fifo tx_queue;
#if CONFIG_BT_ATT_PREPARE_COUNT > 0
sys_slist_t prep_queue;
#endif
/* Contains bt_att_chan instance(s) */
sys_slist_t chans;
#if defined(CONFIG_BT_EATT)
struct {
struct k_work_delayable connection_work;
uint8_t chans_to_connect;
uint16_t prev_conn_rsp_result;
uint16_t prev_conn_req_result;
uint8_t prev_conn_req_missing_chans;
} eatt;
#endif /* CONFIG_BT_EATT */
};
K_MEM_SLAB_DEFINE(att_slab, sizeof(struct bt_att),
CONFIG_BT_MAX_CONN, __alignof__(struct bt_att));
K_MEM_SLAB_DEFINE(chan_slab, sizeof(struct bt_att_chan),
CONFIG_BT_MAX_CONN * ATT_CHAN_MAX,
__alignof__(struct bt_att_chan));
static struct bt_att_req cancel;
/** The thread ATT response handlers likely run on.
*
* Blocking this thread while waiting for an ATT request to resolve can cause a
* deadlock.
*
* This can happen if the application queues ATT requests in the context of a
* callback from the Bluetooth stack. This is because queuing an ATT request
* will block until a request-resource is available, and the callbacks run on
* the same thread as the ATT response handler that frees request-resources.
*
* The intended use of this value is to detect the above situation.
*/
static k_tid_t att_handle_rsp_thread;
static struct bt_att_tx_meta_data tx_meta_data_storage[CONFIG_BT_ATT_TX_COUNT];
struct bt_att_tx_meta_data *bt_att_get_tx_meta_data(const struct net_buf *buf);
static void att_on_sent_cb(struct bt_att_tx_meta_data *meta);
static void att_tx_destroy(struct net_buf *buf)
{
struct bt_att_tx_meta_data *p_meta = bt_att_get_tx_meta_data(buf);
struct bt_att_tx_meta_data meta;
LOG_DBG("%p", buf);
/* Destroy the buffer first, as the callback may attempt to allocate a
* new one for another operation.
*/
meta = *p_meta;
/* Clear the meta storage. This might help catch illegal
* "use-after-free"s. An initial memset is not necessary, as the
* metadata storage array is `static`.
*/
memset(p_meta, 0x00, sizeof(*p_meta));
/* After this point, p_meta doesn't belong to us.
* The user data will be memset to 0 on allocation.
*/
net_buf_destroy(buf);
/* ATT opcode 0 is invalid. If we get here, that means the buffer got
* destroyed before it was ready to be sent. Hopefully nobody sets the
* opcode and then destroys the buffer without sending it. :'(
*/
if (meta.opcode != 0) {
att_on_sent_cb(&meta);
}
}
NET_BUF_POOL_DEFINE(att_pool, CONFIG_BT_ATT_TX_COUNT,
BT_L2CAP_SDU_BUF_SIZE(BT_ATT_BUF_SIZE),
CONFIG_BT_CONN_TX_USER_DATA_SIZE, att_tx_destroy);
struct bt_att_tx_meta_data *bt_att_get_tx_meta_data(const struct net_buf *buf)
{
__ASSERT_NO_MSG(net_buf_pool_get(buf->pool_id) == &att_pool);
/* Metadata lifetime is implicitly tied to the buffer lifetime.
* Treat it as part of the buffer itself.
*/
return &tx_meta_data_storage[net_buf_id((struct net_buf *)buf)];
}
static int bt_att_chan_send(struct bt_att_chan *chan, struct net_buf *buf);
static void att_chan_mtu_updated(struct bt_att_chan *updated_chan);
static void bt_att_disconnected(struct bt_l2cap_chan *chan);
struct net_buf *bt_att_create_rsp_pdu(struct bt_att_chan *chan, uint8_t op);
static void bt_att_sent(struct bt_l2cap_chan *ch);
static void att_sent(void *user_data)
{
struct bt_att_tx_meta_data *data = user_data;
struct bt_att_chan *att_chan = data->att_chan;
struct bt_conn *conn = att_chan->att->conn;
struct bt_l2cap_chan *chan = &att_chan->chan.chan;
__ASSERT_NO_MSG(!bt_att_is_enhanced(att_chan));
LOG_DBG("conn %p chan %p", conn, chan);
/* For EATT, `bt_att_sent` is assigned to the `.sent` L2 callback.
* L2CAP will then call it once the SDU has finished sending.
*
* For UATT, this won't happen, as static LE l2cap channels don't have
* SDUs. Call it manually instead.
*/
bt_att_sent(chan);
}
/* In case of success the ownership of the buffer is transferred to the stack
* which takes care of releasing it when it completes transmitting to the
* controller.
*
* In case bt_l2cap_send_cb fails the buffer state and ownership are retained
* so the buffer can be safely pushed back to the queue to be processed later.
*/
static int chan_send(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_hdr *hdr;
struct net_buf_simple_state state;
int err;
struct bt_att_tx_meta_data *data = bt_att_get_tx_meta_data(buf);
struct bt_att_chan *prev_chan = data->att_chan;
hdr = (void *)buf->data;
LOG_DBG("code 0x%02x", hdr->code);
if (!atomic_test_bit(chan->flags, ATT_CONNECTED)) {
LOG_ERR("ATT channel not connected");
return -EINVAL;
}
if (IS_ENABLED(CONFIG_BT_EATT) && hdr->code == BT_ATT_OP_MTU_REQ &&
chan->chan.tx.cid != BT_L2CAP_CID_ATT) {
/* The Exchange MTU sub-procedure shall only be supported on
* the LE Fixed Channel Unenhanced ATT bearer
*/
return -ENOTSUP;
}
__ASSERT_NO_MSG(buf->len >= sizeof(struct bt_att_hdr));
data->opcode = buf->data[0];
data->err = 0;
if (IS_ENABLED(CONFIG_BT_EATT) && bt_att_is_enhanced(chan)) {
/* Check if sent is pending already, if it does it cannot be
* modified so the operation will need to be queued.
*/
if (atomic_test_bit(chan->flags, ATT_PENDING_SENT)) {
return -EAGAIN;
}
if (hdr->code == BT_ATT_OP_SIGNED_WRITE_CMD) {
return -ENOTSUP;
}
/* Check if the channel is ready to send in case of a request */
if (att_op_get_type(hdr->code) == ATT_REQUEST &&
!atomic_test_bit(chan->chan.chan.status,
BT_L2CAP_STATUS_OUT)) {
return -EAGAIN;
}
atomic_set_bit(chan->flags, ATT_PENDING_SENT);
data->att_chan = chan;
/* bt_l2cap_chan_send does actually return the number of bytes
* that could be sent immediately.
*/
err = bt_l2cap_chan_send(&chan->chan.chan, buf);
if (err < 0) {
data->att_chan = prev_chan;
atomic_clear_bit(chan->flags, ATT_PENDING_SENT);
data->err = err;
return err;
} else {
/* On success, the almighty scheduler might already have
* run the destroy cb on the buffer. In that case, buf
* and its metadata are dangling pointers.
*/
buf = NULL;
data = NULL;
}
return 0;
}
if (hdr->code == BT_ATT_OP_SIGNED_WRITE_CMD) {
err = bt_smp_sign(chan->att->conn, buf);
if (err) {
LOG_ERR("Error signing data");
net_buf_unref(buf);
return err;
}
}
net_buf_simple_save(&buf->b, &state);
data->att_chan = chan;
err = bt_l2cap_send(chan->att->conn, BT_L2CAP_CID_ATT, buf);
if (err) {
if (err == -ENOBUFS) {
LOG_ERR("Ran out of TX buffers or contexts.");
}
/* In case of an error has occurred restore the buffer state */
net_buf_simple_restore(&buf->b, &state);
data->att_chan = prev_chan;
data->err = err;
}
return err;
}
static bool att_chan_matches_chan_opt(struct bt_att_chan *chan, enum bt_att_chan_opt chan_opt)
{
__ASSERT_NO_MSG(chan_opt <= BT_ATT_CHAN_OPT_ENHANCED_ONLY);
if (chan_opt == BT_ATT_CHAN_OPT_NONE) {
return true;
}
if (bt_att_is_enhanced(chan)) {
return (chan_opt & BT_ATT_CHAN_OPT_ENHANCED_ONLY);
} else {
return (chan_opt & BT_ATT_CHAN_OPT_UNENHANCED_ONLY);
}
}
static struct net_buf *get_first_buf_matching_chan(struct k_fifo *fifo, struct bt_att_chan *chan)
{
if (IS_ENABLED(CONFIG_BT_EATT)) {
struct k_fifo skipped;
struct net_buf *buf;
struct net_buf *ret = NULL;
struct bt_att_tx_meta_data *meta;
k_fifo_init(&skipped);
while ((buf = net_buf_get(fifo, K_NO_WAIT))) {
meta = bt_att_get_tx_meta_data(buf);
if (!ret &&
att_chan_matches_chan_opt(chan, meta->chan_opt)) {
ret = buf;
} else {
net_buf_put(&skipped, buf);
}
}
__ASSERT_NO_MSG(k_fifo_is_empty(fifo));
while ((buf = net_buf_get(&skipped, K_NO_WAIT))) {
net_buf_put(fifo, buf);
}
__ASSERT_NO_MSG(k_fifo_is_empty(&skipped));
return ret;
} else {
return net_buf_get(fifo, K_NO_WAIT);
}
}
static struct bt_att_req *get_first_req_matching_chan(sys_slist_t *reqs, struct bt_att_chan *chan)
{
if (IS_ENABLED(CONFIG_BT_EATT)) {
sys_snode_t *curr, *prev = NULL;
struct bt_att_tx_meta_data *meta = NULL;
SYS_SLIST_FOR_EACH_NODE(reqs, curr) {
meta = bt_att_get_tx_meta_data(ATT_REQ(curr)->buf);
if (att_chan_matches_chan_opt(chan, meta->chan_opt)) {
break;
}
prev = curr;
}
if (curr) {
sys_slist_remove(reqs, prev, curr);
return ATT_REQ(curr);
}
return NULL;
}
sys_snode_t *node = sys_slist_get(reqs);
if (node) {
return ATT_REQ(node);
} else {
return NULL;
}
}
static int process_queue(struct bt_att_chan *chan, struct k_fifo *queue)
{
struct net_buf *buf;
int err;
buf = get_first_buf_matching_chan(queue, chan);
if (buf) {
err = bt_att_chan_send(chan, buf);
if (err) {
/* Push it back if it could not be send */
k_queue_prepend(&queue->_queue, buf);
return err;
}
return 0;
}
return -ENOENT;
}
/* Send requests without taking tx_sem */
static int chan_req_send(struct bt_att_chan *chan, struct bt_att_req *req)
{
struct net_buf *buf;
int err;
if (bt_att_mtu(chan) < net_buf_frags_len(req->buf)) {
return -EMSGSIZE;
}
LOG_DBG("chan %p req %p len %zu", chan, req, net_buf_frags_len(req->buf));
chan->req = req;
/* Release since bt_l2cap_send_cb takes ownership of the buffer */
buf = req->buf;
req->buf = NULL;
/* This lock makes sure the value of `bt_att_mtu(chan)` does not
* change.
*/
k_sched_lock();
err = bt_att_chan_send(chan, buf);
if (err) {
/* We still have the ownership of the buffer */
req->buf = buf;
chan->req = NULL;
} else {
bt_gatt_req_set_mtu(req, bt_att_mtu(chan));
}
k_sched_unlock();
return err;
}
static void bt_att_sent(struct bt_l2cap_chan *ch)
{
struct bt_att_chan *chan = ATT_CHAN(ch);
struct bt_att *att = chan->att;
int err;
LOG_DBG("chan %p", chan);
atomic_clear_bit(chan->flags, ATT_PENDING_SENT);
if (!att) {
LOG_DBG("Ignore sent on detached ATT chan");
return;
}
/* Process pending requests first since they require a response they
* can only be processed one at time while if other queues were
* processed before they may always contain a buffer starving the
* request queue.
*/
if (!chan->req && !sys_slist_is_empty(&att->reqs)) {
sys_snode_t *node = sys_slist_get(&att->reqs);
if (chan_req_send(chan, ATT_REQ(node)) >= 0) {
return;
}
/* Prepend back to the list as it could not be sent */
sys_slist_prepend(&att->reqs, node);
}
/* Process channel queue */
err = process_queue(chan, &chan->tx_queue);
if (!err) {
return;
}
/* Process global queue */
(void)process_queue(chan, &att->tx_queue);
}
static void chan_rebegin_att_timeout(struct bt_att_tx_meta_data *user_data)
{
struct bt_att_tx_meta_data *data = user_data;
struct bt_att_chan *chan = data->att_chan;
LOG_DBG("chan %p chan->req %p", chan, chan->req);
if (!atomic_test_bit(chan->flags, ATT_CONNECTED)) {
LOG_ERR("ATT channel not connected");
return;
}
/* Start timeout work. Only if we are sure that the request is really
* in-flight.
*/
if (chan->req) {
k_work_reschedule(&chan->timeout_work, BT_ATT_TIMEOUT);
}
}
static void chan_req_notif_sent(struct bt_att_tx_meta_data *user_data)
{
struct bt_att_tx_meta_data *data = user_data;
struct bt_att_chan *chan = data->att_chan;
struct bt_conn *conn = chan->att->conn;
bt_gatt_complete_func_t func = data->func;
uint16_t attr_count = data->attr_count;
void *ud = data->user_data;
LOG_DBG("chan %p CID 0x%04X", chan, chan->chan.tx.cid);
if (!atomic_test_bit(chan->flags, ATT_CONNECTED)) {
LOG_ERR("ATT channel not connected");
return;
}
if (func) {
for (uint16_t i = 0; i < attr_count; i++) {
func(conn, ud);
}
}
}
static void att_on_sent_cb(struct bt_att_tx_meta_data *meta)
{
const att_type_t op_type = att_op_get_type(meta->opcode);
LOG_DBG("opcode 0x%x", meta->opcode);
if (!meta->att_chan ||
!meta->att_chan->att ||
!meta->att_chan->att->conn) {
LOG_DBG("Bearer not connected, dropping ATT cb");
return;
}
if (meta->err) {
LOG_ERR("Got err %d, not calling ATT cb", meta->err);
return;
}
if (!bt_att_is_enhanced(meta->att_chan)) {
/* For EATT, L2CAP will call it after the SDU is fully sent. */
LOG_DBG("UATT bearer, calling att_sent");
att_sent(meta);
}
switch (op_type) {
case ATT_RESPONSE:
return;
case ATT_CONFIRMATION:
return;
case ATT_REQUEST:
case ATT_INDICATION:
chan_rebegin_att_timeout(meta);
return;
case ATT_COMMAND:
case ATT_NOTIFICATION:
chan_req_notif_sent(meta);
return;
default:
__ASSERT(false, "Unknown op type 0x%02X", op_type);
return;
}
}
static struct net_buf *bt_att_chan_create_pdu(struct bt_att_chan *chan, uint8_t op, size_t len)
{
struct bt_att_hdr *hdr;
struct net_buf *buf;
struct bt_att_tx_meta_data *data;
k_timeout_t timeout;
if (len + sizeof(op) > bt_att_mtu(chan)) {
LOG_WRN("ATT MTU exceeded, max %u, wanted %zu", bt_att_mtu(chan),
len + sizeof(op));
return NULL;
}
switch (att_op_get_type(op)) {
case ATT_RESPONSE:
case ATT_CONFIRMATION:
/* Use a timeout only when responding/confirming */
timeout = BT_ATT_TIMEOUT;
break;
default:
timeout = K_FOREVER;
}
/* This will reserve headspace for lower layers */
buf = bt_l2cap_create_pdu_timeout(&att_pool, 0, timeout);
if (!buf) {
LOG_ERR("Unable to allocate buffer for op 0x%02x", op);
return NULL;
}
/* If we got a buf from `att_pool`, then the metadata slot at its index
* is officially ours to use.
*/
data = bt_att_get_tx_meta_data(buf);
if (IS_ENABLED(CONFIG_BT_EATT)) {
net_buf_reserve(buf, BT_L2CAP_SDU_BUF_SIZE(0));
}
data->att_chan = chan;
hdr = net_buf_add(buf, sizeof(*hdr));
hdr->code = op;
return buf;
}
static int bt_att_chan_send(struct bt_att_chan *chan, struct net_buf *buf)
{
LOG_DBG("chan %p flags %lu code 0x%02x", chan, atomic_get(chan->flags),
((struct bt_att_hdr *)buf->data)->code);
if (IS_ENABLED(CONFIG_BT_EATT) &&
!att_chan_matches_chan_opt(chan, bt_att_get_tx_meta_data(buf)->chan_opt)) {
return -EINVAL;
}
return chan_send(chan, buf);
}
static void att_send_process(struct bt_att *att)
{
struct bt_att_chan *chan, *tmp, *prev = NULL;
int err = 0;
SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&att->chans, chan, tmp, node) {
if (err == -ENOENT && prev &&
(bt_att_is_enhanced(chan) == bt_att_is_enhanced(prev))) {
/* If there was nothing to send for the previous channel and the current
* channel has the same "enhancedness", there will be nothing to send for
* this channel either.
*/
continue;
}
err = process_queue(chan, &att->tx_queue);
if (!err) {
/* Success */
return;
}
prev = chan;
}
}
static void bt_att_chan_send_rsp(struct bt_att_chan *chan, struct net_buf *buf)
{
int err;
err = chan_send(chan, buf);
if (err) {
/* Responses need to be sent back using the same channel */
net_buf_put(&chan->tx_queue, buf);
}
}
static void send_err_rsp(struct bt_att_chan *chan, uint8_t req, uint16_t handle,
uint8_t err)
{
struct bt_att_error_rsp *rsp;
struct net_buf *buf;
/* Ignore opcode 0x00 */
if (!req) {
return;
}
buf = bt_att_chan_create_pdu(chan, BT_ATT_OP_ERROR_RSP, sizeof(*rsp));
if (!buf) {
return;
}
rsp = net_buf_add(buf, sizeof(*rsp));
rsp->request = req;
rsp->handle = sys_cpu_to_le16(handle);
rsp->error = err;
bt_att_chan_send_rsp(chan, buf);
}
static uint8_t att_mtu_req(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_exchange_mtu_req *req;
struct bt_att_exchange_mtu_rsp *rsp;
struct net_buf *pdu;
uint16_t mtu_client, mtu_server;
/* Exchange MTU sub-procedure shall only be supported on the
* LE Fixed Channel Unenhanced ATT bearer.
*/
if (bt_att_is_enhanced(chan)) {
return BT_ATT_ERR_NOT_SUPPORTED;
}
req = (void *)buf->data;
mtu_client = sys_le16_to_cpu(req->mtu);
LOG_DBG("Client MTU %u", mtu_client);
/* Check if MTU is valid */
if (mtu_client < BT_ATT_DEFAULT_LE_MTU) {
return BT_ATT_ERR_INVALID_PDU;
}
pdu = bt_att_create_rsp_pdu(chan, BT_ATT_OP_MTU_RSP);
if (!pdu) {
return BT_ATT_ERR_UNLIKELY;
}
mtu_server = BT_LOCAL_ATT_MTU_UATT;
LOG_DBG("Server MTU %u", mtu_server);
rsp = net_buf_add(pdu, sizeof(*rsp));
rsp->mtu = sys_cpu_to_le16(mtu_server);
bt_att_chan_send_rsp(chan, pdu);
/* The ATT_EXCHANGE_MTU_REQ/RSP is just an alternative way of
* communicating the L2CAP MTU.
*/
chan->chan.rx.mtu = mtu_server;
chan->chan.tx.mtu = mtu_client;
LOG_DBG("Negotiated MTU %u", bt_att_mtu(chan));
#if defined(CONFIG_BT_GATT_CLIENT)
/* Mark the MTU Exchange as complete.
* This will skip sending ATT Exchange MTU from our side.
*
* Core 5.3 | Vol 3, Part F 3.4.2.2:
* If MTU is exchanged in one direction, that is sufficient for both directions.
*/
atomic_set_bit(chan->att->conn->flags, BT_CONN_ATT_MTU_EXCHANGED);
#endif /* CONFIG_BT_GATT_CLIENT */
att_chan_mtu_updated(chan);
return 0;
}
static int bt_att_chan_req_send(struct bt_att_chan *chan,
struct bt_att_req *req)
{
__ASSERT_NO_MSG(chan);
__ASSERT_NO_MSG(req);
__ASSERT_NO_MSG(req->func);
__ASSERT_NO_MSG(!chan->req);
LOG_DBG("req %p", req);
return chan_req_send(chan, req);
}
static void att_req_send_process(struct bt_att *att)
{
struct bt_att_req *req = NULL;
struct bt_att_chan *chan, *tmp, *prev = NULL;
SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&att->chans, chan, tmp, node) {
/* If there is an ongoing transaction, do not use the channel */
if (chan->req) {
continue;
}
if (!req && prev && (bt_att_is_enhanced(chan) == bt_att_is_enhanced(prev))) {
/* If there was nothing to send for the previous channel and the current
* channel has the same "enhancedness", there will be nothing to send for
* this channel either.
*/
continue;
}
prev = chan;
/* Pull next request from the list */
req = get_first_req_matching_chan(&att->reqs, chan);
if (!req) {
continue;
}
if (bt_att_chan_req_send(chan, req) >= 0) {
return;
}
/* Prepend back to the list as it could not be sent */
sys_slist_prepend(&att->reqs, &req->node);
}
}
static uint8_t att_handle_rsp(struct bt_att_chan *chan, void *pdu, uint16_t len,
int err)
{
bt_att_func_t func = NULL;
void *params;
LOG_DBG("chan %p err %d len %u: %s", chan, err, len, bt_hex(pdu, len));
/* Cancel timeout if ongoing */
k_work_cancel_delayable(&chan->timeout_work);
if (!chan->req) {
LOG_WRN("No pending ATT request");
goto process;
}
/* Check if request has been cancelled */
if (chan->req == &cancel) {
chan->req = NULL;
goto process;
}
/* Reset func so it can be reused by the callback */
func = chan->req->func;
chan->req->func = NULL;
params = chan->req->user_data;
/* free allocated request so its memory can be reused */
bt_att_req_free(chan->req);
chan->req = NULL;
process:
/* Process pending requests */
att_req_send_process(chan->att);
if (func) {
func(chan->att->conn, err, pdu, len, params);
}
return 0;
}
#if defined(CONFIG_BT_GATT_CLIENT)
static uint8_t att_mtu_rsp(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_exchange_mtu_rsp *rsp;
uint16_t mtu;
rsp = (void *)buf->data;
mtu = sys_le16_to_cpu(rsp->mtu);
LOG_DBG("Server MTU %u", mtu);
/* Check if MTU is valid */
if (mtu < BT_ATT_DEFAULT_LE_MTU) {
return att_handle_rsp(chan, NULL, 0, BT_ATT_ERR_INVALID_PDU);
}
/* The following must equal the value we sent in the req. We assume this
* is a rsp to `gatt_exchange_mtu_encode`.
*/
chan->chan.rx.mtu = BT_LOCAL_ATT_MTU_UATT;
/* The ATT_EXCHANGE_MTU_REQ/RSP is just an alternative way of
* communicating the L2CAP MTU.
*/
chan->chan.tx.mtu = mtu;
LOG_DBG("Negotiated MTU %u", bt_att_mtu(chan));
att_chan_mtu_updated(chan);
return att_handle_rsp(chan, rsp, buf->len, 0);
}
#endif /* CONFIG_BT_GATT_CLIENT */
static bool range_is_valid(uint16_t start, uint16_t end, uint16_t *err)
{
/* Handle 0 is invalid */
if (!start || !end) {
if (err) {
*err = 0U;
}
return false;
}
/* Check if range is valid */
if (start > end) {
if (err) {
*err = start;
}
return false;
}
return true;
}
struct find_info_data {
struct bt_att_chan *chan;
struct net_buf *buf;
struct bt_att_find_info_rsp *rsp;
union {
struct bt_att_info_16 *info16;
struct bt_att_info_128 *info128;
};
};
static uint8_t find_info_cb(const struct bt_gatt_attr *attr, uint16_t handle,
void *user_data)
{
struct find_info_data *data = user_data;
struct bt_att_chan *chan = data->chan;
LOG_DBG("handle 0x%04x", handle);
/* Initialize rsp at first entry */
if (!data->rsp) {
data->rsp = net_buf_add(data->buf, sizeof(*data->rsp));
data->rsp->format = (attr->uuid->type == BT_UUID_TYPE_16) ?
BT_ATT_INFO_16 : BT_ATT_INFO_128;
}
switch (data->rsp->format) {
case BT_ATT_INFO_16:
if (attr->uuid->type != BT_UUID_TYPE_16) {
return BT_GATT_ITER_STOP;
}
/* Fast forward to next item position */
data->info16 = net_buf_add(data->buf, sizeof(*data->info16));
data->info16->handle = sys_cpu_to_le16(handle);
data->info16->uuid = sys_cpu_to_le16(BT_UUID_16(attr->uuid)->val);
if (bt_att_mtu(chan) - data->buf->len >
sizeof(*data->info16)) {
return BT_GATT_ITER_CONTINUE;
}
break;
case BT_ATT_INFO_128:
if (attr->uuid->type != BT_UUID_TYPE_128) {
return BT_GATT_ITER_STOP;
}
/* Fast forward to next item position */
data->info128 = net_buf_add(data->buf, sizeof(*data->info128));
data->info128->handle = sys_cpu_to_le16(handle);
memcpy(data->info128->uuid, BT_UUID_128(attr->uuid)->val,
sizeof(data->info128->uuid));
if (bt_att_mtu(chan) - data->buf->len >
sizeof(*data->info128)) {
return BT_GATT_ITER_CONTINUE;
}
}
return BT_GATT_ITER_STOP;
}
static uint8_t att_find_info_rsp(struct bt_att_chan *chan, uint16_t start_handle,
uint16_t end_handle)
{
struct find_info_data data;
(void)memset(&data, 0, sizeof(data));
data.buf = bt_att_create_rsp_pdu(chan, BT_ATT_OP_FIND_INFO_RSP);
if (!data.buf) {
return BT_ATT_ERR_INSUFFICIENT_RESOURCES;
}
data.chan = chan;
bt_gatt_foreach_attr(start_handle, end_handle, find_info_cb, &data);
if (!data.rsp) {
net_buf_unref(data.buf);
/* Respond since handle is set */
send_err_rsp(chan, BT_ATT_OP_FIND_INFO_REQ, start_handle,
BT_ATT_ERR_ATTRIBUTE_NOT_FOUND);
return 0;
}
bt_att_chan_send_rsp(chan, data.buf);
return 0;
}
static uint8_t att_find_info_req(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_find_info_req *req;
uint16_t start_handle, end_handle, err_handle;
req = (void *)buf->data;
start_handle = sys_le16_to_cpu(req->start_handle);
end_handle = sys_le16_to_cpu(req->end_handle);
LOG_DBG("start_handle 0x%04x end_handle 0x%04x", start_handle, end_handle);
if (!range_is_valid(start_handle, end_handle, &err_handle)) {
send_err_rsp(chan, BT_ATT_OP_FIND_INFO_REQ, err_handle,
BT_ATT_ERR_INVALID_HANDLE);
return 0;
}
return att_find_info_rsp(chan, start_handle, end_handle);
}
struct find_type_data {
struct bt_att_chan *chan;
struct net_buf *buf;
struct bt_att_handle_group *group;
const void *value;
uint8_t value_len;
uint8_t err;
};
static uint8_t find_type_cb(const struct bt_gatt_attr *attr, uint16_t handle,
void *user_data)
{
struct find_type_data *data = user_data;
struct bt_att_chan *chan = data->chan;
struct bt_conn *conn = chan->chan.chan.conn;
int read;
uint8_t uuid[16];
struct net_buf *frag;
size_t len;
/* Skip secondary services */
if (!bt_uuid_cmp(attr->uuid, BT_UUID_GATT_SECONDARY)) {
goto skip;
}
/* Update group end_handle if not a primary service */
if (bt_uuid_cmp(attr->uuid, BT_UUID_GATT_PRIMARY)) {
if (data->group &&
handle > sys_le16_to_cpu(data->group->end_handle)) {
data->group->end_handle = sys_cpu_to_le16(handle);
}
return BT_GATT_ITER_CONTINUE;
}
LOG_DBG("handle 0x%04x", handle);
/* stop if there is no space left */
if (bt_att_mtu(chan) - net_buf_frags_len(data->buf) <
sizeof(*data->group)) {
return BT_GATT_ITER_STOP;
}
frag = net_buf_frag_last(data->buf);
len = MIN(bt_att_mtu(chan) - net_buf_frags_len(data->buf),
net_buf_tailroom(frag));
if (!len) {
frag = net_buf_alloc(net_buf_pool_get(data->buf->pool_id),
K_NO_WAIT);
/* If not buffer can be allocated immediately stop */
if (!frag) {
return BT_GATT_ITER_STOP;
}
net_buf_frag_add(data->buf, frag);
}
/* Read attribute value and store in the buffer */
read = attr->read(conn, attr, uuid, sizeof(uuid), 0);
if (read < 0) {
/*
* Since we don't know if it is the service with requested UUID,
* we cannot respond with an error to this request.
*/
goto skip;
}
/* Check if data matches */
if (read != data->value_len) {
/* Use bt_uuid_cmp() to compare UUIDs of different form. */
struct bt_uuid_128 ref_uuid;
struct bt_uuid_128 recvd_uuid;
if (!bt_uuid_create(&recvd_uuid.uuid, data->value, data->value_len)) {
LOG_WRN("Unable to create UUID: size %u", data->value_len);
goto skip;
}
if (!bt_uuid_create(&ref_uuid.uuid, uuid, read)) {
LOG_WRN("Unable to create UUID: size %d", read);
goto skip;
}
if (bt_uuid_cmp(&recvd_uuid.uuid, &ref_uuid.uuid)) {
goto skip;
}
} else if (memcmp(data->value, uuid, read)) {
goto skip;
}
/* If service has been found, error should be cleared */
data->err = 0x00;
/* Fast forward to next item position */
data->group = net_buf_add(frag, sizeof(*data->group));
data->group->start_handle = sys_cpu_to_le16(handle);
data->group->end_handle = sys_cpu_to_le16(handle);
/* continue to find the end_handle */
return BT_GATT_ITER_CONTINUE;
skip:
data->group = NULL;
return BT_GATT_ITER_CONTINUE;
}
static uint8_t att_find_type_rsp(struct bt_att_chan *chan, uint16_t start_handle,
uint16_t end_handle, const void *value,
uint8_t value_len)
{
struct find_type_data data;
(void)memset(&data, 0, sizeof(data));
data.buf = bt_att_create_rsp_pdu(chan, BT_ATT_OP_FIND_TYPE_RSP);
if (!data.buf) {
return BT_ATT_ERR_INSUFFICIENT_RESOURCES;
}
data.chan = chan;
data.group = NULL;
data.value = value;
data.value_len = value_len;
/* Pre-set error in case no service will be found */
data.err = BT_ATT_ERR_ATTRIBUTE_NOT_FOUND;
bt_gatt_foreach_attr(start_handle, end_handle, find_type_cb, &data);
/* If error has not been cleared, no service has been found */
if (data.err) {
net_buf_unref(data.buf);
/* Respond since handle is set */
send_err_rsp(chan, BT_ATT_OP_FIND_TYPE_REQ, start_handle,
data.err);
return 0;
}
bt_att_chan_send_rsp(chan, data.buf);
return 0;
}
static uint8_t att_find_type_req(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_find_type_req *req;
uint16_t start_handle, end_handle, err_handle, type;
uint8_t *value;
req = net_buf_pull_mem(buf, sizeof(*req));
start_handle = sys_le16_to_cpu(req->start_handle);
end_handle = sys_le16_to_cpu(req->end_handle);
type = sys_le16_to_cpu(req->type);
value = buf->data;
LOG_DBG("start_handle 0x%04x end_handle 0x%04x type %u", start_handle, end_handle, type);
if (!range_is_valid(start_handle, end_handle, &err_handle)) {
send_err_rsp(chan, BT_ATT_OP_FIND_TYPE_REQ, err_handle,
BT_ATT_ERR_INVALID_HANDLE);
return 0;
}
/* The Attribute Protocol Find By Type Value Request shall be used with
* the Attribute Type parameter set to the UUID for "Primary Service"
* and the Attribute Value set to the 16-bit Bluetooth UUID or 128-bit
* UUID for the specific primary service.
*/
if (bt_uuid_cmp(BT_UUID_DECLARE_16(type), BT_UUID_GATT_PRIMARY)) {
send_err_rsp(chan, BT_ATT_OP_FIND_TYPE_REQ, start_handle,
BT_ATT_ERR_ATTRIBUTE_NOT_FOUND);
return 0;
}
return att_find_type_rsp(chan, start_handle, end_handle, value,
buf->len);
}
static uint8_t err_to_att(int err)
{
LOG_DBG("%d", err);
if (err < 0 && err >= -0xff) {
return -err;
}
return BT_ATT_ERR_UNLIKELY;
}
struct read_type_data {
struct bt_att_chan *chan;
struct bt_uuid *uuid;
struct net_buf *buf;
struct bt_att_read_type_rsp *rsp;
struct bt_att_data *item;
uint8_t err;
};
typedef bool (*attr_read_cb)(struct net_buf *buf, ssize_t read,
void *user_data);
static bool attr_read_authorize(struct bt_conn *conn,
const struct bt_gatt_attr *attr)
{
if (!IS_ENABLED(CONFIG_BT_GATT_AUTHORIZATION_CUSTOM)) {
return true;
}
if (!authorization_cb || !authorization_cb->read_authorize) {
return true;
}
return authorization_cb->read_authorize(conn, attr);
}
static bool attr_read_type_cb(struct net_buf *frag, ssize_t read,
void *user_data)
{
struct read_type_data *data = user_data;
if (!data->rsp->len) {
/* Set len to be the first item found */
data->rsp->len = read + sizeof(*data->item);
} else if (data->rsp->len != read + sizeof(*data->item)) {
/* All items should have the same size */
frag->len -= sizeof(*data->item);
data->item = NULL;
return false;
}
return true;
}
static ssize_t att_chan_read(struct bt_att_chan *chan,
const struct bt_gatt_attr *attr,
struct net_buf *buf, uint16_t offset,
attr_read_cb cb, void *user_data)
{
struct bt_conn *conn = chan->chan.chan.conn;
ssize_t read;
struct net_buf *frag;
size_t len, total = 0;
if (bt_att_mtu(chan) <= net_buf_frags_len(buf)) {
return 0;
}
frag = net_buf_frag_last(buf);
/* Create necessary fragments if MTU is bigger than what a buffer can
* hold.
*/
do {
len = MIN(bt_att_mtu(chan) - net_buf_frags_len(buf),
net_buf_tailroom(frag));
if (!len) {
frag = net_buf_alloc(net_buf_pool_get(buf->pool_id),
K_NO_WAIT);
/* If not buffer can be allocated immediately return */
if (!frag) {
return total;
}
net_buf_frag_add(buf, frag);
len = MIN(bt_att_mtu(chan) - net_buf_frags_len(buf),
net_buf_tailroom(frag));
}
read = attr->read(conn, attr, frag->data + frag->len, len,
offset);
if (read < 0) {
if (total) {
return total;
}
return read;
}
if (cb && !cb(frag, read, user_data)) {
break;
}
net_buf_add(frag, read);
total += read;
offset += read;
} while (bt_att_mtu(chan) > net_buf_frags_len(buf) && read == len);
return total;
}
static uint8_t read_type_cb(const struct bt_gatt_attr *attr, uint16_t handle,
void *user_data)
{
struct read_type_data *data = user_data;
struct bt_att_chan *chan = data->chan;
struct bt_conn *conn = chan->chan.chan.conn;
ssize_t read;
/* Skip if doesn't match */
if (bt_uuid_cmp(attr->uuid, data->uuid)) {
return BT_GATT_ITER_CONTINUE;
}
LOG_DBG("handle 0x%04x", handle);
/*
* If an attribute in the set of requested attributes would cause an
* Error Response then this attribute cannot be included in a
* Read By Type Response and the attributes before this attribute
* shall be returned
*
* If the first attribute in the set of requested attributes would
* cause an Error Response then no other attributes in the requested
* attributes can be considered.
*/
data->err = bt_gatt_check_perm(conn, attr, BT_GATT_PERM_READ_MASK);
if (data->err) {
if (data->rsp->len) {
data->err = 0x00;
}
return BT_GATT_ITER_STOP;
}
/* Check the attribute authorization logic */
if (!attr_read_authorize(conn, attr)) {
data->err = BT_ATT_ERR_AUTHORIZATION;
return BT_GATT_ITER_STOP;
}
/*
* If any attribute is founded in handle range it means that error
* should be changed from pre-set: attr not found error to no error.
*/
data->err = 0x00;
/* Fast forward to next item position */
data->item = net_buf_add(net_buf_frag_last(data->buf),
sizeof(*data->item));
data->item->handle = sys_cpu_to_le16(handle);
read = att_chan_read(chan, attr, data->buf, 0, attr_read_type_cb, data);
if (read < 0) {
data->err = err_to_att(read);
return BT_GATT_ITER_STOP;
}
if (!data->item) {
return BT_GATT_ITER_STOP;
}
/* continue only if there are still space for more items */
return bt_att_mtu(chan) - net_buf_frags_len(data->buf) >
data->rsp->len ? BT_GATT_ITER_CONTINUE : BT_GATT_ITER_STOP;
}
static uint8_t att_read_type_rsp(struct bt_att_chan *chan, struct bt_uuid *uuid,
uint16_t start_handle, uint16_t end_handle)
{
struct read_type_data data;
(void)memset(&data, 0, sizeof(data));
data.buf = bt_att_create_rsp_pdu(chan, BT_ATT_OP_READ_TYPE_RSP);
if (!data.buf) {
return BT_ATT_ERR_INSUFFICIENT_RESOURCES;
}
data.chan = chan;
data.uuid = uuid;
data.rsp = net_buf_add(data.buf, sizeof(*data.rsp));
data.rsp->len = 0U;
/* Pre-set error if no attr will be found in handle */
data.err = BT_ATT_ERR_ATTRIBUTE_NOT_FOUND;
bt_gatt_foreach_attr(start_handle, end_handle, read_type_cb, &data);
if (data.err) {
net_buf_unref(data.buf);
/* Response here since handle is set */
send_err_rsp(chan, BT_ATT_OP_READ_TYPE_REQ, start_handle,
data.err);
return 0;
}
bt_att_chan_send_rsp(chan, data.buf);
return 0;
}
static uint8_t att_read_type_req(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_read_type_req *req;
uint16_t start_handle, end_handle, err_handle;
union {
struct bt_uuid uuid;
struct bt_uuid_16 u16;
struct bt_uuid_128 u128;
} u;
uint8_t uuid_len = buf->len - sizeof(*req);
/* Type can only be UUID16 or UUID128 */
if (uuid_len != 2 && uuid_len != 16) {
return BT_ATT_ERR_INVALID_PDU;
}
req = net_buf_pull_mem(buf, sizeof(*req));
start_handle = sys_le16_to_cpu(req->start_handle);
end_handle = sys_le16_to_cpu(req->end_handle);
if (!bt_uuid_create(&u.uuid, req->uuid, uuid_len)) {
return BT_ATT_ERR_UNLIKELY;
}
LOG_DBG("start_handle 0x%04x end_handle 0x%04x type %s", start_handle, end_handle,
bt_uuid_str(&u.uuid));
if (!range_is_valid(start_handle, end_handle, &err_handle)) {
send_err_rsp(chan, BT_ATT_OP_READ_TYPE_REQ, err_handle,
BT_ATT_ERR_INVALID_HANDLE);
return 0;
}
return att_read_type_rsp(chan, &u.uuid, start_handle, end_handle);
}
struct read_data {
struct bt_att_chan *chan;
uint16_t offset;
struct net_buf *buf;
uint8_t err;
};
static uint8_t read_cb(const struct bt_gatt_attr *attr, uint16_t handle,
void *user_data)
{
struct read_data *data = user_data;
struct bt_att_chan *chan = data->chan;
struct bt_conn *conn = chan->chan.chan.conn;
int ret;
LOG_DBG("handle 0x%04x", handle);
/*
* If any attribute is founded in handle range it means that error
* should be changed from pre-set: invalid handle error to no error.
*/
data->err = 0x00;
/* Check attribute permissions */
data->err = bt_gatt_check_perm(conn, attr, BT_GATT_PERM_READ_MASK);
if (data->err) {
return BT_GATT_ITER_STOP;
}
/* Check the attribute authorization logic */
if (!attr_read_authorize(conn, attr)) {
data->err = BT_ATT_ERR_AUTHORIZATION;
return BT_GATT_ITER_STOP;
}
/* Read attribute value and store in the buffer */
ret = att_chan_read(chan, attr, data->buf, data->offset, NULL, NULL);
if (ret < 0) {
data->err = err_to_att(ret);
return BT_GATT_ITER_STOP;
}
return BT_GATT_ITER_CONTINUE;
}
static uint8_t att_read_rsp(struct bt_att_chan *chan, uint8_t op, uint8_t rsp,
uint16_t handle, uint16_t offset)
{
struct read_data data;
if (!bt_gatt_change_aware(chan->att->conn, true)) {
if (!atomic_test_and_set_bit(chan->flags, ATT_OUT_OF_SYNC_SENT)) {
return BT_ATT_ERR_DB_OUT_OF_SYNC;
} else {
return 0;
}
}
if (!handle) {
return BT_ATT_ERR_INVALID_HANDLE;
}
(void)memset(&data, 0, sizeof(data));
data.buf = bt_att_create_rsp_pdu(chan, rsp);
if (!data.buf) {
return BT_ATT_ERR_INSUFFICIENT_RESOURCES;
}
data.chan = chan;
data.offset = offset;
/* Pre-set error if no attr will be found in handle */
data.err = BT_ATT_ERR_INVALID_HANDLE;
bt_gatt_foreach_attr(handle, handle, read_cb, &data);
/* In case of error discard data and respond with an error */
if (data.err) {
net_buf_unref(data.buf);
/* Respond here since handle is set */
send_err_rsp(chan, op, handle, data.err);
return 0;
}
bt_att_chan_send_rsp(chan, data.buf);
return 0;
}
static uint8_t att_read_req(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_read_req *req;
uint16_t handle;
req = (void *)buf->data;
handle = sys_le16_to_cpu(req->handle);
LOG_DBG("handle 0x%04x", handle);
return att_read_rsp(chan, BT_ATT_OP_READ_REQ, BT_ATT_OP_READ_RSP,
handle, 0);
}
static uint8_t att_read_blob_req(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_read_blob_req *req;
uint16_t handle, offset;
req = (void *)buf->data;
handle = sys_le16_to_cpu(req->handle);
offset = sys_le16_to_cpu(req->offset);
LOG_DBG("handle 0x%04x offset %u", handle, offset);
return att_read_rsp(chan, BT_ATT_OP_READ_BLOB_REQ,
BT_ATT_OP_READ_BLOB_RSP, handle, offset);
}
#if defined(CONFIG_BT_GATT_READ_MULTIPLE)
static uint8_t att_read_mult_req(struct bt_att_chan *chan, struct net_buf *buf)
{
struct read_data data;
uint16_t handle;
if (!bt_gatt_change_aware(chan->att->conn, true)) {
if (!atomic_test_and_set_bit(chan->flags, ATT_OUT_OF_SYNC_SENT)) {
return BT_ATT_ERR_DB_OUT_OF_SYNC;
} else {
return 0;
}
}
(void)memset(&data, 0, sizeof(data));
data.buf = bt_att_create_rsp_pdu(chan, BT_ATT_OP_READ_MULT_RSP);
if (!data.buf) {
return BT_ATT_ERR_INSUFFICIENT_RESOURCES;
}
data.chan = chan;
while (buf->len >= sizeof(uint16_t)) {
handle = net_buf_pull_le16(buf);
LOG_DBG("handle 0x%04x ", handle);
/* An Error Response shall be sent by the server in response to
* the Read Multiple Request [....] if a read operation is not
* permitted on any of the Characteristic Values.
*
* If handle is not valid then return invalid handle error.
* If handle is found error will be cleared by read_cb.
*/
data.err = BT_ATT_ERR_INVALID_HANDLE;
bt_gatt_foreach_attr(handle, handle, read_cb, &data);
/* Stop reading in case of error */
if (data.err) {
net_buf_unref(data.buf);
/* Respond here since handle is set */
send_err_rsp(chan, BT_ATT_OP_READ_MULT_REQ, handle,
data.err);
return 0;
}
}
bt_att_chan_send_rsp(chan, data.buf);
return 0;
}
#endif /* CONFIG_BT_GATT_READ_MULTIPLE */
#if defined(CONFIG_BT_GATT_READ_MULT_VAR_LEN)
static uint8_t read_vl_cb(const struct bt_gatt_attr *attr, uint16_t handle,
void *user_data)
{
struct read_data *data = user_data;
struct bt_att_chan *chan = data->chan;
struct bt_conn *conn = chan->chan.chan.conn;
struct bt_att_read_mult_vl_rsp *rsp;
int read;
LOG_DBG("handle 0x%04x", handle);
/*
* If any attribute is founded in handle range it means that error
* should be changed from pre-set: invalid handle error to no error.
*/
data->err = 0x00;
/* Check attribute permissions */
data->err = bt_gatt_check_perm(conn, attr, BT_GATT_PERM_READ_MASK);
if (data->err) {
return BT_GATT_ITER_STOP;
}
/* Check the attribute authorization logic */
if (!attr_read_authorize(conn, attr)) {
data->err = BT_ATT_ERR_AUTHORIZATION;
return BT_GATT_ITER_STOP;
}
/* The Length Value Tuple List may be truncated within the first two
* octets of a tuple due to the size limits of the current ATT_MTU.
*/
if (bt_att_mtu(chan) - data->buf->len < 2) {
return BT_GATT_ITER_STOP;
}
rsp = net_buf_add(data->buf, sizeof(*rsp));
read = att_chan_read(chan, attr, data->buf, data->offset, NULL, NULL);
if (read < 0) {
data->err = err_to_att(read);
return BT_GATT_ITER_STOP;
}
rsp->len = read;
return BT_GATT_ITER_CONTINUE;
}
static uint8_t att_read_mult_vl_req(struct bt_att_chan *chan, struct net_buf *buf)
{
struct read_data data;
uint16_t handle;
if (!bt_gatt_change_aware(chan->att->conn, true)) {
if (!atomic_test_and_set_bit(chan->flags, ATT_OUT_OF_SYNC_SENT)) {
return BT_ATT_ERR_DB_OUT_OF_SYNC;
} else {
return 0;
}
}
(void)memset(&data, 0, sizeof(data));
data.buf = bt_att_create_rsp_pdu(chan, BT_ATT_OP_READ_MULT_VL_RSP);
if (!data.buf) {
return BT_ATT_ERR_INSUFFICIENT_RESOURCES;
}
data.chan = chan;
while (buf->len >= sizeof(uint16_t)) {
handle = net_buf_pull_le16(buf);
LOG_DBG("handle 0x%04x ", handle);
/* If handle is not valid then return invalid handle error.
* If handle is found error will be cleared by read_cb.
*/
data.err = BT_ATT_ERR_INVALID_HANDLE;
bt_gatt_foreach_attr(handle, handle, read_vl_cb, &data);
/* Stop reading in case of error */
if (data.err) {
net_buf_unref(data.buf);
/* Respond here since handle is set */
send_err_rsp(chan, BT_ATT_OP_READ_MULT_VL_REQ, handle,
data.err);
return 0;
}
}
bt_att_chan_send_rsp(chan, data.buf);
return 0;
}
#endif /* CONFIG_BT_GATT_READ_MULT_VAR_LEN */
struct read_group_data {
struct bt_att_chan *chan;
struct bt_uuid *uuid;
struct net_buf *buf;
struct bt_att_read_group_rsp *rsp;
struct bt_att_group_data *group;
};
static bool attr_read_group_cb(struct net_buf *frag, ssize_t read,
void *user_data)
{
struct read_group_data *data = user_data;
if (!data->rsp->len) {
/* Set len to be the first group found */
data->rsp->len = read + sizeof(*data->group);
} else if (data->rsp->len != read + sizeof(*data->group)) {
/* All groups entries should have the same size */
data->buf->len -= sizeof(*data->group);
data->group = NULL;
return false;
}
return true;
}
static uint8_t read_group_cb(const struct bt_gatt_attr *attr, uint16_t handle,
void *user_data)
{
struct read_group_data *data = user_data;
struct bt_att_chan *chan = data->chan;
int read;
/* Update group end_handle if attribute is not a service */
if (bt_uuid_cmp(attr->uuid, BT_UUID_GATT_PRIMARY) &&
bt_uuid_cmp(attr->uuid, BT_UUID_GATT_SECONDARY)) {
if (data->group &&
handle > sys_le16_to_cpu(data->group->end_handle)) {
data->group->end_handle = sys_cpu_to_le16(handle);
}
return BT_GATT_ITER_CONTINUE;
}
/* If Group Type don't match skip */
if (bt_uuid_cmp(attr->uuid, data->uuid)) {
data->group = NULL;
return BT_GATT_ITER_CONTINUE;
}
LOG_DBG("handle 0x%04x", handle);
/* Stop if there is no space left */
if (data->rsp->len &&
bt_att_mtu(chan) - data->buf->len < data->rsp->len) {
return BT_GATT_ITER_STOP;
}
/* Fast forward to next group position */
data->group = net_buf_add(data->buf, sizeof(*data->group));
/* Initialize group handle range */
data->group->start_handle = sys_cpu_to_le16(handle);
data->group->end_handle = sys_cpu_to_le16(handle);
/* Read attribute value and store in the buffer */
read = att_chan_read(chan, attr, data->buf, 0, attr_read_group_cb,
data);
if (read < 0) {
/* TODO: Handle read errors */
return BT_GATT_ITER_STOP;
}
if (!data->group) {
return BT_GATT_ITER_STOP;
}
/* continue only if there are still space for more items */
return BT_GATT_ITER_CONTINUE;
}
static uint8_t att_read_group_rsp(struct bt_att_chan *chan, struct bt_uuid *uuid,
uint16_t start_handle, uint16_t end_handle)
{
struct read_group_data data;
(void)memset(&data, 0, sizeof(data));
data.buf = bt_att_create_rsp_pdu(chan, BT_ATT_OP_READ_GROUP_RSP);
if (!data.buf) {
return BT_ATT_ERR_INSUFFICIENT_RESOURCES;
}
data.chan = chan;
data.uuid = uuid;
data.rsp = net_buf_add(data.buf, sizeof(*data.rsp));
data.rsp->len = 0U;
data.group = NULL;
bt_gatt_foreach_attr(start_handle, end_handle, read_group_cb, &data);
if (!data.rsp->len) {
net_buf_unref(data.buf);
/* Respond here since handle is set */
send_err_rsp(chan, BT_ATT_OP_READ_GROUP_REQ, start_handle,
BT_ATT_ERR_ATTRIBUTE_NOT_FOUND);
return 0;
}
bt_att_chan_send_rsp(chan, data.buf);
return 0;
}
static uint8_t att_read_group_req(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_read_group_req *req;
uint16_t start_handle, end_handle, err_handle;
union {
struct bt_uuid uuid;
struct bt_uuid_16 u16;
struct bt_uuid_128 u128;
} u;
uint8_t uuid_len = buf->len - sizeof(*req);
/* Type can only be UUID16 or UUID128 */
if (uuid_len != 2 && uuid_len != 16) {
return BT_ATT_ERR_INVALID_PDU;
}
req = net_buf_pull_mem(buf, sizeof(*req));
start_handle = sys_le16_to_cpu(req->start_handle);
end_handle = sys_le16_to_cpu(req->end_handle);
if (!bt_uuid_create(&u.uuid, req->uuid, uuid_len)) {
return BT_ATT_ERR_UNLIKELY;
}
LOG_DBG("start_handle 0x%04x end_handle 0x%04x type %s", start_handle, end_handle,
bt_uuid_str(&u.uuid));
if (!range_is_valid(start_handle, end_handle, &err_handle)) {
send_err_rsp(chan, BT_ATT_OP_READ_GROUP_REQ, err_handle,
BT_ATT_ERR_INVALID_HANDLE);
return 0;
}
/* Core v4.2, Vol 3, sec 2.5.3 Attribute Grouping:
* Not all of the grouping attributes can be used in the ATT
* Read By Group Type Request. The "Primary Service" and "Secondary
* Service" grouping types may be used in the Read By Group Type
* Request. The "Characteristic" grouping type shall not be used in
* the ATT Read By Group Type Request.
*/
if (bt_uuid_cmp(&u.uuid, BT_UUID_GATT_PRIMARY) &&
bt_uuid_cmp(&u.uuid, BT_UUID_GATT_SECONDARY)) {
send_err_rsp(chan, BT_ATT_OP_READ_GROUP_REQ, start_handle,
BT_ATT_ERR_UNSUPPORTED_GROUP_TYPE);
return 0;
}
return att_read_group_rsp(chan, &u.uuid, start_handle, end_handle);
}
struct write_data {
struct bt_conn *conn;
struct net_buf *buf;
uint8_t req;
const void *value;
uint16_t len;
uint16_t offset;
uint8_t err;
};
static bool attr_write_authorize(struct bt_conn *conn,
const struct bt_gatt_attr *attr)
{
if (!IS_ENABLED(CONFIG_BT_GATT_AUTHORIZATION_CUSTOM)) {
return true;
}
if (!authorization_cb || !authorization_cb->write_authorize) {
return true;
}
return authorization_cb->write_authorize(conn, attr);
}
static uint8_t write_cb(const struct bt_gatt_attr *attr, uint16_t handle,
void *user_data)
{
struct write_data *data = user_data;
int write;
uint8_t flags = 0U;
LOG_DBG("handle 0x%04x offset %u", handle, data->offset);
/* Check attribute permissions */
data->err = bt_gatt_check_perm(data->conn, attr,
BT_GATT_PERM_WRITE_MASK);
if (data->err) {
return BT_GATT_ITER_STOP;
}
/* Check the attribute authorization logic */
if (!attr_write_authorize(data->conn, attr)) {
data->err = BT_ATT_ERR_AUTHORIZATION;
return BT_GATT_ITER_STOP;
}
/* Set command flag if not a request */
if (!data->req) {
flags |= BT_GATT_WRITE_FLAG_CMD;
} else if (data->req == BT_ATT_OP_EXEC_WRITE_REQ) {
flags |= BT_GATT_WRITE_FLAG_EXECUTE;
}
/* Write attribute value */
write = attr->write(data->conn, attr, data->value, data->len,
data->offset, flags);
if (write < 0 || write != data->len) {
data->err = err_to_att(write);
return BT_GATT_ITER_STOP;
}
data->err = 0U;
return BT_GATT_ITER_CONTINUE;
}
static uint8_t att_write_rsp(struct bt_att_chan *chan, uint8_t req, uint8_t rsp,
uint16_t handle, uint16_t offset, const void *value,
uint16_t len)
{
struct write_data data;
if (!bt_gatt_change_aware(chan->att->conn, req ? true : false)) {
if (!atomic_test_and_set_bit(chan->flags, ATT_OUT_OF_SYNC_SENT)) {
return BT_ATT_ERR_DB_OUT_OF_SYNC;
} else {
return 0;
}
}
if (!handle) {
return BT_ATT_ERR_INVALID_HANDLE;
}
(void)memset(&data, 0, sizeof(data));
/* Only allocate buf if required to respond */
if (rsp) {
data.buf = bt_att_chan_create_pdu(chan, rsp, 0);
if (!data.buf) {
return BT_ATT_ERR_INSUFFICIENT_RESOURCES;
}
}
data.conn = chan->att->conn;
data.req = req;
data.offset = offset;
data.value = value;
data.len = len;
data.err = BT_ATT_ERR_INVALID_HANDLE;
bt_gatt_foreach_attr(handle, handle, write_cb, &data);
if (data.err) {
/* In case of error discard data and respond with an error */
if (rsp) {
net_buf_unref(data.buf);
/* Respond here since handle is set */
send_err_rsp(chan, req, handle, data.err);
}
return req == BT_ATT_OP_EXEC_WRITE_REQ ? data.err : 0;
}
if (data.buf) {
bt_att_chan_send_rsp(chan, data.buf);
}
return 0;
}
static uint8_t att_write_req(struct bt_att_chan *chan, struct net_buf *buf)
{
uint16_t handle;
handle = net_buf_pull_le16(buf);
LOG_DBG("handle 0x%04x", handle);
return att_write_rsp(chan, BT_ATT_OP_WRITE_REQ, BT_ATT_OP_WRITE_RSP,
handle, 0, buf->data, buf->len);
}
#if CONFIG_BT_ATT_PREPARE_COUNT > 0
struct prep_data {
struct bt_conn *conn;
struct net_buf *buf;
const void *value;
uint16_t len;
uint16_t offset;
uint8_t err;
};
static uint8_t prep_write_cb(const struct bt_gatt_attr *attr, uint16_t handle,
void *user_data)
{
struct prep_data *data = user_data;
struct bt_attr_data *attr_data;
int write;
LOG_DBG("handle 0x%04x offset %u", handle, data->offset);
/* Check attribute permissions */
data->err = bt_gatt_check_perm(data->conn, attr,
BT_GATT_PERM_WRITE_MASK);
if (data->err) {
return BT_GATT_ITER_STOP;
}
/* Check the attribute authorization logic */
if (!attr_write_authorize(data->conn, attr)) {
data->err = BT_ATT_ERR_AUTHORIZATION;
return BT_GATT_ITER_STOP;
}
/* Check if attribute requires handler to accept the data */
if (!(attr->perm & BT_GATT_PERM_PREPARE_WRITE)) {
goto append;
}
/* Write attribute value to check if device is authorized */
write = attr->write(data->conn, attr, data->value, data->len,
data->offset, BT_GATT_WRITE_FLAG_PREPARE);
if (write != 0) {
data->err = err_to_att(write);
return BT_GATT_ITER_STOP;
}
append:
/* Copy data into the outstanding queue */
data->buf = net_buf_alloc(&prep_pool, K_NO_WAIT);
if (!data->buf) {
data->err = BT_ATT_ERR_PREPARE_QUEUE_FULL;
return BT_GATT_ITER_STOP;
}
attr_data = net_buf_user_data(data->buf);
attr_data->handle = handle;
attr_data->offset = data->offset;
net_buf_add_mem(data->buf, data->value, data->len);
data->err = 0U;
return BT_GATT_ITER_CONTINUE;
}
static uint8_t att_prep_write_rsp(struct bt_att_chan *chan, uint16_t handle,
uint16_t offset, const void *value, uint8_t len)
{
struct prep_data data;
struct bt_att_prepare_write_rsp *rsp;
if (!bt_gatt_change_aware(chan->att->conn, true)) {
if (!atomic_test_and_set_bit(chan->flags, ATT_OUT_OF_SYNC_SENT)) {
return BT_ATT_ERR_DB_OUT_OF_SYNC;
} else {
return 0;
}
}
if (!handle) {
return BT_ATT_ERR_INVALID_HANDLE;
}
(void)memset(&data, 0, sizeof(data));
data.conn = chan->att->conn;
data.offset = offset;
data.value = value;
data.len = len;
data.err = BT_ATT_ERR_INVALID_HANDLE;
bt_gatt_foreach_attr(handle, handle, prep_write_cb, &data);
if (data.err) {
/* Respond here since handle is set */
send_err_rsp(chan, BT_ATT_OP_PREPARE_WRITE_REQ, handle,
data.err);
return 0;
}
LOG_DBG("buf %p handle 0x%04x offset %u", data.buf, handle, offset);
/* Store buffer in the outstanding queue */
net_buf_slist_put(&chan->att->prep_queue, data.buf);
/* Generate response */
data.buf = bt_att_create_rsp_pdu(chan, BT_ATT_OP_PREPARE_WRITE_RSP);
if (!data.buf) {
return BT_ATT_ERR_INSUFFICIENT_RESOURCES;
}
rsp = net_buf_add(data.buf, sizeof(*rsp));
rsp->handle = sys_cpu_to_le16(handle);
rsp->offset = sys_cpu_to_le16(offset);
net_buf_add(data.buf, len);
memcpy(rsp->value, value, len);
bt_att_chan_send_rsp(chan, data.buf);
return 0;
}
#endif /* CONFIG_BT_ATT_PREPARE_COUNT */
static uint8_t att_prepare_write_req(struct bt_att_chan *chan, struct net_buf *buf)
{
#if CONFIG_BT_ATT_PREPARE_COUNT == 0
return BT_ATT_ERR_NOT_SUPPORTED;
#else
struct bt_att_prepare_write_req *req;
uint16_t handle, offset;
req = net_buf_pull_mem(buf, sizeof(*req));
handle = sys_le16_to_cpu(req->handle);
offset = sys_le16_to_cpu(req->offset);
LOG_DBG("handle 0x%04x offset %u", handle, offset);
return att_prep_write_rsp(chan, handle, offset, buf->data, buf->len);
#endif /* CONFIG_BT_ATT_PREPARE_COUNT */
}
#if CONFIG_BT_ATT_PREPARE_COUNT > 0
static uint8_t exec_write_reassemble(uint16_t handle, uint16_t offset,
sys_slist_t *list,
struct net_buf_simple *buf)
{
struct net_buf *entry, *next;
sys_snode_t *prev;
prev = NULL;
SYS_SLIST_FOR_EACH_CONTAINER_SAFE(list, entry, next, node) {
struct bt_attr_data *tmp_data = net_buf_user_data(entry);
LOG_DBG("entry %p handle 0x%04x, offset %u", entry, tmp_data->handle,
tmp_data->offset);
if (tmp_data->handle == handle) {
if (tmp_data->offset == 0) {
/* Multiple writes to the same handle can occur
* in a prepare write queue. If the offset is 0,
* that should mean that it's a new write to the
* same handle, and we break to process the
* first write.
*/
LOG_DBG("tmp_data->offset == 0");
break;
}
if (tmp_data->offset != buf->len + offset) {
/* We require that the offset is increasing
* properly to avoid badly reassembled buffers
*/
LOG_DBG("Bad offset %u (%u, %u)", tmp_data->offset, buf->len,
offset);
return BT_ATT_ERR_INVALID_OFFSET;
}
if (buf->len + entry->len > buf->size) {
return BT_ATT_ERR_INVALID_ATTRIBUTE_LEN;
}
net_buf_simple_add_mem(buf, entry->data, entry->len);
sys_slist_remove(list, prev, &entry->node);
net_buf_unref(entry);
} else {
prev = &entry->node;
}
}
return BT_ATT_ERR_SUCCESS;
}
static uint8_t att_exec_write_rsp(struct bt_att_chan *chan, uint8_t flags)
{
struct net_buf *buf;
uint8_t err = 0U;
/* The following code will iterate on all prepare writes in the
* prep_queue, and reassemble those that share the same handle.
* Once a handle has been ressembled, it is sent to the upper layers,
* and the next handle is processed
*/
while (!sys_slist_is_empty(&chan->att->prep_queue)) {
struct bt_attr_data *data;
uint16_t handle;
NET_BUF_SIMPLE_DEFINE_STATIC(reassembled_data,
MIN(BT_ATT_MAX_ATTRIBUTE_LEN,
CONFIG_BT_ATT_PREPARE_COUNT * BT_ATT_BUF_SIZE));
buf = net_buf_slist_get(&chan->att->prep_queue);
data = net_buf_user_data(buf);
handle = data->handle;
LOG_DBG("buf %p handle 0x%04x offset %u", buf, handle, data->offset);
net_buf_simple_reset(&reassembled_data);
net_buf_simple_add_mem(&reassembled_data, buf->data, buf->len);
err = exec_write_reassemble(handle, data->offset,
&chan->att->prep_queue,
&reassembled_data);
if (err != BT_ATT_ERR_SUCCESS) {
send_err_rsp(chan, BT_ATT_OP_EXEC_WRITE_REQ,
handle, err);
return 0;
}
/* Just discard the data if an error was set */
if (!err && flags == BT_ATT_FLAG_EXEC) {
err = att_write_rsp(chan, BT_ATT_OP_EXEC_WRITE_REQ, 0,
handle, data->offset,
reassembled_data.data,
reassembled_data.len);
if (err) {
/* Respond here since handle is set */
send_err_rsp(chan, BT_ATT_OP_EXEC_WRITE_REQ,
data->handle, err);
}
}
net_buf_unref(buf);
}
if (err) {
return 0;
}
/* Generate response */
buf = bt_att_create_rsp_pdu(chan, BT_ATT_OP_EXEC_WRITE_RSP);
if (!buf) {
return BT_ATT_ERR_UNLIKELY;
}
bt_att_chan_send_rsp(chan, buf);
return 0;
}
#endif /* CONFIG_BT_ATT_PREPARE_COUNT */
static uint8_t att_exec_write_req(struct bt_att_chan *chan, struct net_buf *buf)
{
#if CONFIG_BT_ATT_PREPARE_COUNT == 0
return BT_ATT_ERR_NOT_SUPPORTED;
#else
struct bt_att_exec_write_req *req;
req = (void *)buf->data;
LOG_DBG("flags 0x%02x", req->flags);
return att_exec_write_rsp(chan, req->flags);
#endif /* CONFIG_BT_ATT_PREPARE_COUNT */
}
static uint8_t att_write_cmd(struct bt_att_chan *chan, struct net_buf *buf)
{
uint16_t handle;
handle = net_buf_pull_le16(buf);
LOG_DBG("handle 0x%04x", handle);
return att_write_rsp(chan, 0, 0, handle, 0, buf->data, buf->len);
}
#if defined(CONFIG_BT_SIGNING)
static uint8_t att_signed_write_cmd(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_conn *conn = chan->chan.chan.conn;
struct bt_att_signed_write_cmd *req;
uint16_t handle;
int err;
/* The Signed Write Without Response sub-procedure shall only be supported
* on the LE Fixed Channel Unenhanced ATT bearer.
*/
if (bt_att_is_enhanced(chan)) {
/* No response for this command */
return 0;
}
req = (void *)buf->data;
handle = sys_le16_to_cpu(req->handle);
LOG_DBG("handle 0x%04x", handle);
/* Verifying data requires full buffer including attribute header */
net_buf_push(buf, sizeof(struct bt_att_hdr));
err = bt_smp_sign_verify(conn, buf);
if (err) {
LOG_ERR("Error verifying data");
/* No response for this command */
return 0;
}
net_buf_pull(buf, sizeof(struct bt_att_hdr));
net_buf_pull(buf, sizeof(*req));
return att_write_rsp(chan, 0, 0, handle, 0, buf->data,
buf->len - sizeof(struct bt_att_signature));
}
#endif /* CONFIG_BT_SIGNING */
#if defined(CONFIG_BT_GATT_CLIENT)
#if defined(CONFIG_BT_ATT_RETRY_ON_SEC_ERR)
static int att_change_security(struct bt_conn *conn, uint8_t err)
{
bt_security_t sec;
switch (err) {
case BT_ATT_ERR_INSUFFICIENT_ENCRYPTION:
if (conn->sec_level >= BT_SECURITY_L2)
return -EALREADY;
sec = BT_SECURITY_L2;
break;
case BT_ATT_ERR_AUTHENTICATION:
if (conn->sec_level < BT_SECURITY_L2) {
/* BLUETOOTH SPECIFICATION Version 4.2 [Vol 3, Part C]
* page 375:
*
* If an LTK is not available, the service request
* shall be rejected with the error code 'Insufficient
* Authentication'.
* Note: When the link is not encrypted, the error code
* "Insufficient Authentication" does not indicate that
* MITM protection is required.
*/
sec = BT_SECURITY_L2;
} else if (conn->sec_level < BT_SECURITY_L3) {
/* BLUETOOTH SPECIFICATION Version 4.2 [Vol 3, Part C]
* page 375:
*
* If an authenticated pairing is required but only an
* unauthenticated pairing has occurred and the link is
* currently encrypted, the service request shall be
* rejected with the error code 'Insufficient
* Authentication'.
* Note: When unauthenticated pairing has occurred and
* the link is currently encrypted, the error code
* 'Insufficient Authentication' indicates that MITM
* protection is required.
*/
sec = BT_SECURITY_L3;
} else if (conn->sec_level < BT_SECURITY_L4) {
/* BLUETOOTH SPECIFICATION Version 4.2 [Vol 3, Part C]
* page 375:
*
* If LE Secure Connections authenticated pairing is
* required but LE legacy pairing has occurred and the
* link is currently encrypted, the service request
* shall be rejected with the error code ''Insufficient
* Authentication'.
*/
sec = BT_SECURITY_L4;
} else {
return -EALREADY;
}
break;
default:
return -EINVAL;
}
return bt_conn_set_security(conn, sec);
}
#endif /* CONFIG_BT_ATT_RETRY_ON_SEC_ERR */
static uint8_t att_error_rsp(struct bt_att_chan *chan, struct net_buf *buf)
{
struct bt_att_error_rsp *rsp;
uint8_t err;
rsp = (void *)buf->data;
LOG_DBG("request 0x%02x handle 0x%04x error 0x%02x", rsp->request,
sys_le16_to_cpu(rsp->handle), rsp->error);
/* Don't retry if there is no req pending or it has been cancelled.
*
* BLUETOOTH SPECIFICATION Version 5.2 [Vol 3, Part F]
* page 1423:
*
* If an error code is received in the ATT_ERROR_RSP PDU that is not
* understood by the client, for example an error code that was reserved
* for future use that is now being used in a future version of the
* specification, then the ATT_ERROR_RSP PDU shall still be considered to
* state that the given request cannot be performed for an unknown reason.
*/
if (!chan->req || chan->req == &cancel || !rsp->error) {
err = BT_ATT_ERR_UNLIKELY;
goto done;
}
err = rsp->error;
#if defined(CONFIG_BT_ATT_RETRY_ON_SEC_ERR)
int ret;
/* Check if error can be handled by elevating security. */
ret = att_change_security(chan->chan.chan.conn, err);
if (ret == 0 || ret == -EBUSY) {
/* ATT timeout work is normally cancelled in att_handle_rsp.
* However retrying is special case, so the timeout shall
* be cancelled here.
*/
k_work_cancel_delayable(&chan->timeout_work);
chan->req->retrying = true;
return 0;
}
#endif /* CONFIG_BT_ATT_RETRY_ON_SEC_ERR */
done:
return att_handle_rsp(chan, NULL, 0, err);
}
static uint8_t att_handle_find_info_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
static uint8_t att_handle_find_type_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
static uint8_t att_handle_read_type_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
static uint8_t att_handle_read_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
static uint8_t att_handle_read_blob_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
#if defined(CONFIG_BT_GATT_READ_MULTIPLE)
static uint8_t att_handle_read_mult_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
#endif /* CONFIG_BT_GATT_READ_MULTIPLE */
#if defined(CONFIG_BT_GATT_READ_MULT_VAR_LEN)
static uint8_t att_handle_read_mult_vl_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
#endif /* CONFIG_BT_GATT_READ_MULT_VAR_LEN */
static uint8_t att_handle_read_group_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
static uint8_t att_handle_write_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
static uint8_t att_handle_prepare_write_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
static uint8_t att_handle_exec_write_rsp(struct bt_att_chan *chan,
struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
static uint8_t att_notify(struct bt_att_chan *chan, struct net_buf *buf)
{
uint16_t handle;
handle = net_buf_pull_le16(buf);
LOG_DBG("chan %p handle 0x%04x", chan, handle);
bt_gatt_notification(chan->att->conn, handle, buf->data, buf->len);
return 0;
}
static uint8_t att_indicate(struct bt_att_chan *chan, struct net_buf *buf)
{
uint16_t handle;
handle = net_buf_pull_le16(buf);
LOG_DBG("chan %p handle 0x%04x", chan, handle);
bt_gatt_notification(chan->att->conn, handle, buf->data, buf->len);
buf = bt_att_chan_create_pdu(chan, BT_ATT_OP_CONFIRM, 0);
if (!buf) {
return 0;
}
bt_att_chan_send_rsp(chan, buf);
return 0;
}
static uint8_t att_notify_mult(struct bt_att_chan *chan, struct net_buf *buf)
{
LOG_DBG("chan %p", chan);
bt_gatt_mult_notification(chan->att->conn, buf->data, buf->len);
return 0;
}
#endif /* CONFIG_BT_GATT_CLIENT */
static uint8_t att_confirm(struct bt_att_chan *chan, struct net_buf *buf)
{
LOG_DBG("");
return att_handle_rsp(chan, buf->data, buf->len, 0);
}
static const struct att_handler {
uint8_t op;
uint8_t expect_len;
att_type_t type;
uint8_t (*func)(struct bt_att_chan *chan, struct net_buf *buf);
} handlers[] = {
{ BT_ATT_OP_MTU_REQ,
sizeof(struct bt_att_exchange_mtu_req),
ATT_REQUEST,
att_mtu_req },
{ BT_ATT_OP_FIND_INFO_REQ,
sizeof(struct bt_att_find_info_req),
ATT_REQUEST,
att_find_info_req },
{ BT_ATT_OP_FIND_TYPE_REQ,
sizeof(struct bt_att_find_type_req),
ATT_REQUEST,
att_find_type_req },
{ BT_ATT_OP_READ_TYPE_REQ,
sizeof(struct bt_att_read_type_req),
ATT_REQUEST,
att_read_type_req },
{ BT_ATT_OP_READ_REQ,
sizeof(struct bt_att_read_req),
ATT_REQUEST,
att_read_req },
{ BT_ATT_OP_READ_BLOB_REQ,
sizeof(struct bt_att_read_blob_req),
ATT_REQUEST,
att_read_blob_req },
#if defined(CONFIG_BT_GATT_READ_MULTIPLE)
{ BT_ATT_OP_READ_MULT_REQ,
BT_ATT_READ_MULT_MIN_LEN_REQ,
ATT_REQUEST,
att_read_mult_req },
#endif /* CONFIG_BT_GATT_READ_MULTIPLE */
#if defined(CONFIG_BT_GATT_READ_MULT_VAR_LEN)
{ BT_ATT_OP_READ_MULT_VL_REQ,
BT_ATT_READ_MULT_MIN_LEN_REQ,
ATT_REQUEST,
att_read_mult_vl_req },
#endif /* CONFIG_BT_GATT_READ_MULT_VAR_LEN */
{ BT_ATT_OP_READ_GROUP_REQ,
sizeof(struct bt_att_read_group_req),
ATT_REQUEST,
att_read_group_req },
{ BT_ATT_OP_WRITE_REQ,
sizeof(struct bt_att_write_req),
ATT_REQUEST,
att_write_req },
{ BT_ATT_OP_PREPARE_WRITE_REQ,
sizeof(struct bt_att_prepare_write_req),
ATT_REQUEST,
att_prepare_write_req },
{ BT_ATT_OP_EXEC_WRITE_REQ,
sizeof(struct bt_att_exec_write_req),
ATT_REQUEST,
att_exec_write_req },
{ BT_ATT_OP_CONFIRM,
0,
ATT_CONFIRMATION,
att_confirm },
{ BT_ATT_OP_WRITE_CMD,
sizeof(struct bt_att_write_cmd),
ATT_COMMAND,
att_write_cmd },
#if defined(CONFIG_BT_SIGNING)
{ BT_ATT_OP_SIGNED_WRITE_CMD,
(sizeof(struct bt_att_write_cmd) +
sizeof(struct bt_att_signature)),
ATT_COMMAND,
att_signed_write_cmd },
#endif /* CONFIG_BT_SIGNING */
#if defined(CONFIG_BT_GATT_CLIENT)
{ BT_ATT_OP_ERROR_RSP,
sizeof(struct bt_att_error_rsp),
ATT_RESPONSE,
att_error_rsp },
{ BT_ATT_OP_MTU_RSP,
sizeof(struct bt_att_exchange_mtu_rsp),
ATT_RESPONSE,
att_mtu_rsp },
{ BT_ATT_OP_FIND_INFO_RSP,
sizeof(struct bt_att_find_info_rsp),
ATT_RESPONSE,
att_handle_find_info_rsp },
{ BT_ATT_OP_FIND_TYPE_RSP,
sizeof(struct bt_att_handle_group),
ATT_RESPONSE,
att_handle_find_type_rsp },
{ BT_ATT_OP_READ_TYPE_RSP,
sizeof(struct bt_att_read_type_rsp),
ATT_RESPONSE,
att_handle_read_type_rsp },
{ BT_ATT_OP_READ_RSP,
0,
ATT_RESPONSE,
att_handle_read_rsp },
{ BT_ATT_OP_READ_BLOB_RSP,
0,
ATT_RESPONSE,
att_handle_read_blob_rsp },
#if defined(CONFIG_BT_GATT_READ_MULTIPLE)
{ BT_ATT_OP_READ_MULT_RSP,
0,
ATT_RESPONSE,
att_handle_read_mult_rsp },
#endif /* CONFIG_BT_GATT_READ_MULTIPLE */
#if defined(CONFIG_BT_GATT_READ_MULT_VAR_LEN)
{ BT_ATT_OP_READ_MULT_VL_RSP,
sizeof(struct bt_att_read_mult_vl_rsp),
ATT_RESPONSE,
att_handle_read_mult_vl_rsp },
#endif /* CONFIG_BT_GATT_READ_MULT_VAR_LEN */
{ BT_ATT_OP_READ_GROUP_RSP,
sizeof(struct bt_att_read_group_rsp),
ATT_RESPONSE,
att_handle_read_group_rsp },
{ BT_ATT_OP_WRITE_RSP,
0,
ATT_RESPONSE,
att_handle_write_rsp },
{ BT_ATT_OP_PREPARE_WRITE_RSP,
sizeof(struct bt_att_prepare_write_rsp),
ATT_RESPONSE,
att_handle_prepare_write_rsp },
{ BT_ATT_OP_EXEC_WRITE_RSP,
0,
ATT_RESPONSE,
att_handle_exec_write_rsp },
{ BT_ATT_OP_NOTIFY,
sizeof(struct bt_att_notify),
ATT_NOTIFICATION,
att_notify },
{ BT_ATT_OP_INDICATE,
sizeof(struct bt_att_indicate),
ATT_INDICATION,
att_indicate },
{ BT_ATT_OP_NOTIFY_MULT,
sizeof(struct bt_att_notify_mult),
ATT_NOTIFICATION,
att_notify_mult },
#endif /* CONFIG_BT_GATT_CLIENT */
};
static att_type_t att_op_get_type(uint8_t op)
{
switch (op) {
case BT_ATT_OP_MTU_REQ:
case BT_ATT_OP_FIND_INFO_REQ:
case BT_ATT_OP_FIND_TYPE_REQ:
case BT_ATT_OP_READ_TYPE_REQ:
case BT_ATT_OP_READ_REQ:
case BT_ATT_OP_READ_BLOB_REQ:
case BT_ATT_OP_READ_MULT_REQ:
case BT_ATT_OP_READ_MULT_VL_REQ:
case BT_ATT_OP_READ_GROUP_REQ:
case BT_ATT_OP_WRITE_REQ:
case BT_ATT_OP_PREPARE_WRITE_REQ:
case BT_ATT_OP_EXEC_WRITE_REQ:
return ATT_REQUEST;
case BT_ATT_OP_CONFIRM:
return ATT_CONFIRMATION;
case BT_ATT_OP_WRITE_CMD:
case BT_ATT_OP_SIGNED_WRITE_CMD:
return ATT_COMMAND;
case BT_ATT_OP_ERROR_RSP:
case BT_ATT_OP_MTU_RSP:
case BT_ATT_OP_FIND_INFO_RSP:
case BT_ATT_OP_FIND_TYPE_RSP:
case BT_ATT_OP_READ_TYPE_RSP:
case BT_ATT_OP_READ_RSP:
case BT_ATT_OP_READ_BLOB_RSP:
case BT_ATT_OP_READ_MULT_RSP:
case BT_ATT_OP_READ_MULT_VL_RSP:
case BT_ATT_OP_READ_GROUP_RSP:
case BT_ATT_OP_WRITE_RSP:
case BT_ATT_OP_PREPARE_WRITE_RSP:
case BT_ATT_OP_EXEC_WRITE_RSP:
return ATT_RESPONSE;
case BT_ATT_OP_NOTIFY:
case BT_ATT_OP_NOTIFY_MULT:
return ATT_NOTIFICATION;
case BT_ATT_OP_INDICATE:
return ATT_INDICATION;
}
if (op & ATT_CMD_MASK) {
return ATT_COMMAND;
}
return ATT_UNKNOWN;
}
static struct bt_conn *get_conn(struct bt_att_chan *att_chan)
{
return att_chan->chan.chan.conn;
}
static int bt_att_recv(struct bt_l2cap_chan *chan, struct net_buf *buf)
{
struct bt_att_chan *att_chan = ATT_CHAN(chan);
struct bt_conn *conn = get_conn(att_chan);
struct bt_att_hdr *hdr;
const struct att_handler *handler;
uint8_t err;
size_t i;
if (buf->len < sizeof(*hdr)) {
LOG_ERR("Too small ATT PDU received");
return 0;
}
hdr = net_buf_pull_mem(buf, sizeof(*hdr));
LOG_DBG("Received ATT chan %p code 0x%02x len %zu", att_chan, hdr->code,
net_buf_frags_len(buf));
if (conn->state != BT_CONN_CONNECTED) {
LOG_DBG("not connected: conn %p state %u", conn, conn->state);
return 0;
}
if (!att_chan->att) {
LOG_DBG("Ignore recv on detached ATT chan");
return 0;
}
for (i = 0, handler = NULL; i < ARRAY_SIZE(handlers); i++) {
if (hdr->code == handlers[i].op) {
handler = &handlers[i];
break;
}
}
if (!handler) {
LOG_WRN("Unhandled ATT code 0x%02x", hdr->code);
if (att_op_get_type(hdr->code) != ATT_COMMAND &&
att_op_get_type(hdr->code) != ATT_INDICATION) {
send_err_rsp(att_chan, hdr->code, 0,
BT_ATT_ERR_NOT_SUPPORTED);
}
return 0;
}
if (buf->len < handler->expect_len) {
LOG_ERR("Invalid len %u for code 0x%02x", buf->len, hdr->code);
err = BT_ATT_ERR_INVALID_PDU;
} else {
err = handler->func(att_chan, buf);
}
if (handler->type == ATT_REQUEST && err) {
LOG_DBG("ATT error 0x%02x", err);
send_err_rsp(att_chan, hdr->code, 0, err);
}
return 0;
}
static struct bt_att *att_get(struct bt_conn *conn)
{
struct bt_l2cap_chan *chan;
struct bt_att_chan *att_chan;
if (conn->state != BT_CONN_CONNECTED) {
LOG_WRN("Not connected");
return NULL;
}
chan = bt_l2cap_le_lookup_rx_cid(conn, BT_L2CAP_CID_ATT);
if (!chan) {
LOG_ERR("Unable to find ATT channel");
return NULL;
}
att_chan = ATT_CHAN(chan);
if (!atomic_test_bit(att_chan->flags, ATT_CONNECTED)) {
LOG_ERR("ATT channel not connected");
return NULL;
}
return att_chan->att;
}
struct net_buf *bt_att_create_pdu(struct bt_conn *conn, uint8_t op, size_t len)
{
struct bt_att *att;
struct bt_att_chan *chan, *tmp;
att = att_get(conn);
if (!att) {
return NULL;
}
/* This allocator should _not_ be used for RSPs. */
SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&att->chans, chan, tmp, node) {
if (len + sizeof(op) > bt_att_mtu(chan)) {
continue;
}
return bt_att_chan_create_pdu(chan, op, len);
}
LOG_WRN("No ATT channel for MTU %zu", len + sizeof(op));
return NULL;
}
struct net_buf *bt_att_create_rsp_pdu(struct bt_att_chan *chan, uint8_t op)
{
size_t headroom;
struct bt_att_hdr *hdr;
struct bt_att_tx_meta_data *data;
struct net_buf *buf;
buf = net_buf_alloc(&att_pool, BT_ATT_TIMEOUT);
if (!buf) {
LOG_ERR("Unable to allocate buffer for op 0x%02x", op);
return NULL;
}
headroom = BT_L2CAP_BUF_SIZE(0);
if (bt_att_is_enhanced(chan)) {
headroom += BT_L2CAP_SDU_HDR_SIZE;
}
net_buf_reserve(buf, headroom);
data = bt_att_get_tx_meta_data(buf);
data->att_chan = chan;
hdr = net_buf_add(buf, sizeof(*hdr));
hdr->code = op;
return buf;
}
static void att_reset(struct bt_att *att)
{
struct net_buf *buf;
#if CONFIG_BT_ATT_PREPARE_COUNT > 0
/* Discard queued buffers */
while ((buf = net_buf_slist_get(&att->prep_queue))) {
net_buf_unref(buf);
}
#endif /* CONFIG_BT_ATT_PREPARE_COUNT > 0 */
#if defined(CONFIG_BT_EATT)
struct k_work_sync sync;
(void)k_work_cancel_delayable_sync(&att->eatt.connection_work, &sync);
#endif /* CONFIG_BT_EATT */
while ((buf = net_buf_get(&att->tx_queue, K_NO_WAIT))) {
net_buf_unref(buf);
}
/* Notify pending requests */
while (!sys_slist_is_empty(&att->reqs)) {
struct bt_att_req *req;
sys_snode_t *node;
node = sys_slist_get_not_empty(&att->reqs);
req = CONTAINER_OF(node, struct bt_att_req, node);
if (req->func) {
req->func(att->conn, -ECONNRESET, NULL, 0,
req->user_data);
}
bt_att_req_free(req);
}
/* FIXME: `att->conn` is not reference counted. Consider using `bt_conn_ref`
* and `bt_conn_unref` to follow convention.
*/
att->conn = NULL;
k_mem_slab_free(&att_slab, (void *)att);
}
static void att_chan_detach(struct bt_att_chan *chan)
{
struct net_buf *buf;
LOG_DBG("chan %p", chan);
sys_slist_find_and_remove(&chan->att->chans, &chan->node);
/* Release pending buffers */
while ((buf = net_buf_get(&chan->tx_queue, K_NO_WAIT))) {
net_buf_unref(buf);
}
if (chan->req) {
/* Notify outstanding request */
att_handle_rsp(chan, NULL, 0, -ECONNRESET);
}
chan->att = NULL;
atomic_clear_bit(chan->flags, ATT_CONNECTED);
}
static void att_timeout(struct k_work *work)
{
char addr[BT_ADDR_LE_STR_LEN];
struct k_work_delayable *dwork = k_work_delayable_from_work(work);
struct bt_att_chan *chan = CONTAINER_OF(dwork, struct bt_att_chan,
timeout_work);
bt_addr_le_to_str(bt_conn_get_dst(chan->att->conn), addr, sizeof(addr));
LOG_ERR("ATT Timeout for device %s", addr);
/* BLUETOOTH SPECIFICATION Version 4.2 [Vol 3, Part F] page 480:
*
* A transaction not completed within 30 seconds shall time out. Such a
* transaction shall be considered to have failed and the local higher
* layers shall be informed of this failure. No more attribute protocol
* requests, commands, indications or notifications shall be sent to the
* target device on this ATT Bearer.
*/
bt_att_disconnected(&chan->chan.chan);
}
static struct bt_att_chan *att_get_fixed_chan(struct bt_conn *conn)
{
struct bt_l2cap_chan *chan;
chan = bt_l2cap_le_lookup_tx_cid(conn, BT_L2CAP_CID_ATT);
__ASSERT(chan, "No ATT channel found");
return ATT_CHAN(chan);
}
static void att_chan_attach(struct bt_att *att, struct bt_att_chan *chan)
{
LOG_DBG("att %p chan %p flags %lu", att, chan, atomic_get(chan->flags));
if (sys_slist_is_empty(&att->chans)) {
/* Init general queues when attaching the first channel */
k_fifo_init(&att->tx_queue);
#if CONFIG_BT_ATT_PREPARE_COUNT > 0
sys_slist_init(&att->prep_queue);
#endif
}
sys_slist_prepend(&att->chans, &chan->node);
}
static void bt_att_connected(struct bt_l2cap_chan *chan)
{
struct bt_att_chan *att_chan = ATT_CHAN(chan);
struct bt_l2cap_le_chan *le_chan = BT_L2CAP_LE_CHAN(chan);
LOG_DBG("chan %p cid 0x%04x", le_chan, le_chan->tx.cid);
atomic_set_bit(att_chan->flags, ATT_CONNECTED);
att_chan_mtu_updated(att_chan);
k_work_init_delayable(&att_chan->timeout_work, att_timeout);
bt_gatt_connected(le_chan->chan.conn);
}
static void bt_att_disconnected(struct bt_l2cap_chan *chan)
{
struct bt_att_chan *att_chan = ATT_CHAN(chan);
struct bt_att *att = att_chan->att;
struct bt_l2cap_le_chan *le_chan = BT_L2CAP_LE_CHAN(chan);
LOG_DBG("chan %p cid 0x%04x", le_chan, le_chan->tx.cid);
if (!att_chan->att) {
LOG_DBG("Ignore disconnect on detached ATT chan");
return;
}
att_chan_detach(att_chan);
/* Don't reset if there are still channels to be used */
if (!sys_slist_is_empty(&att->chans)) {
return;
}
att_reset(att);
bt_gatt_disconnected(le_chan->chan.conn);
}
#if defined(CONFIG_BT_SMP)
static uint8_t att_req_retry(struct bt_att_chan *att_chan)
{
struct bt_att_req *req = att_chan->req;
struct net_buf *buf;
/* Resend buffer */
if (!req->encode) {
/* This request does not support resending */
return BT_ATT_ERR_AUTHENTICATION;
}
buf = bt_att_chan_create_pdu(att_chan, req->att_op, req->len);
if (!buf) {
return BT_ATT_ERR_UNLIKELY;
}
if (req->encode(buf, req->len, req->user_data)) {
net_buf_unref(buf);
return BT_ATT_ERR_UNLIKELY;
}
if (chan_send(att_chan, buf)) {
net_buf_unref(buf);
return BT_ATT_ERR_UNLIKELY;
}
return BT_ATT_ERR_SUCCESS;
}
static void bt_att_encrypt_change(struct bt_l2cap_chan *chan,
uint8_t hci_status)
{
struct bt_att_chan *att_chan = ATT_CHAN(chan);
struct bt_l2cap_le_chan *le_chan = BT_L2CAP_LE_CHAN(chan);
struct bt_conn *conn = le_chan->chan.conn;
uint8_t err;
LOG_DBG("chan %p conn %p handle %u sec_level 0x%02x status 0x%02x", le_chan, conn,
conn->handle, conn->sec_level, hci_status);
if (!att_chan->att) {
LOG_DBG("Ignore encrypt change on detached ATT chan");
return;
}
/*
* If status (HCI status of security procedure) is non-zero, notify
* outstanding request about security failure.
*/
if (hci_status) {
if (att_chan->req && att_chan->req->retrying) {
att_handle_rsp(att_chan, NULL, 0,
BT_ATT_ERR_AUTHENTICATION);
}
return;
}
bt_gatt_encrypt_change(conn);
if (conn->sec_level == BT_SECURITY_L1) {
return;
}
if (!(att_chan->req && att_chan->req->retrying)) {
return;
}
LOG_DBG("Retrying");
err = att_req_retry(att_chan);
if (err) {
LOG_DBG("Retry failed (%d)", err);
att_handle_rsp(att_chan, NULL, 0, err);
}
}
#endif /* CONFIG_BT_SMP */
static void bt_att_status(struct bt_l2cap_chan *ch, atomic_t *status)
{
struct bt_att_chan *chan = ATT_CHAN(ch);
sys_snode_t *node;
LOG_DBG("chan %p status %p", ch, status);
if (!atomic_test_bit(status, BT_L2CAP_STATUS_OUT)) {
return;
}
if (!chan->att) {
LOG_DBG("Ignore status on detached ATT chan");
return;
}
/* If there is a request pending don't attempt to send */
if (chan->req) {
return;
}
/* Pull next request from the list */
node = sys_slist_get(&chan->att->reqs);
if (!node) {
return;
}
if (bt_att_chan_req_send(chan, ATT_REQ(node)) >= 0) {
return;
}
/* Prepend back to the list as it could not be sent */
sys_slist_prepend(&chan->att->reqs, node);
}
static void bt_att_released(struct bt_l2cap_chan *ch)
{
struct bt_att_chan *chan = ATT_CHAN(ch);
LOG_DBG("chan %p", chan);
k_mem_slab_free(&chan_slab, (void *)chan);
}
#if defined(CONFIG_BT_EATT)
static void bt_att_reconfigured(struct bt_l2cap_chan *l2cap_chan)
{
struct bt_att_chan *att_chan = ATT_CHAN(l2cap_chan);
LOG_DBG("chan %p", att_chan);
att_chan_mtu_updated(att_chan);
}
#endif /* CONFIG_BT_EATT */
static struct bt_att_chan *att_chan_new(struct bt_att *att, atomic_val_t flags)
{
int quota = 0;
static struct bt_l2cap_chan_ops ops = {
.connected = bt_att_connected,
.disconnected = bt_att_disconnected,
.recv = bt_att_recv,
.sent = bt_att_sent,
.status = bt_att_status,
#if defined(CONFIG_BT_SMP)
.encrypt_change = bt_att_encrypt_change,
#endif /* CONFIG_BT_SMP */
.released = bt_att_released,
#if defined(CONFIG_BT_EATT)
.reconfigured = bt_att_reconfigured,
#endif /* CONFIG_BT_EATT */
};
struct bt_att_chan *chan;
SYS_SLIST_FOR_EACH_CONTAINER(&att->chans, chan, node) {
if (chan->att == att) {
quota++;
}
if (quota == ATT_CHAN_MAX) {
LOG_DBG("Maximum number of channels reached: %d", quota);
return NULL;
}
}
if (k_mem_slab_alloc(&chan_slab, (void **)&chan, K_NO_WAIT)) {
LOG_WRN("No available ATT channel for conn %p", att->conn);
return NULL;
}
(void)memset(chan, 0, sizeof(*chan));
chan->chan.chan.ops = &ops;
k_fifo_init(&chan->tx_queue);
atomic_set(chan->flags, flags);
chan->att = att;
att_chan_attach(att, chan);
if (bt_att_is_enhanced(chan)) {
/* EATT: The MTU will be sent in the ECRED conn req/rsp PDU. The
* TX MTU is received on L2CAP-level.
*/
chan->chan.rx.mtu = BT_LOCAL_ATT_MTU_EATT;
} else {
/* UATT: L2CAP Basic is not able to communicate the L2CAP MTU
* without help. ATT has to manage the MTU. The initial MTU is
* defined by spec.
*/
chan->chan.tx.mtu = BT_ATT_DEFAULT_LE_MTU;
chan->chan.rx.mtu = BT_ATT_DEFAULT_LE_MTU;
}
return chan;
}
#if defined(CONFIG_BT_EATT)
size_t bt_eatt_count(struct bt_conn *conn)
{
struct bt_att *att;
struct bt_att_chan *chan;
size_t eatt_count = 0;
if (!conn) {
return 0;
}
att = att_get(conn);
if (!att) {
return 0;
}
SYS_SLIST_FOR_EACH_CONTAINER(&att->chans, chan, node) {
if (bt_att_is_enhanced(chan) &&
atomic_test_bit(chan->flags, ATT_CONNECTED)) {
eatt_count++;
}
}
return eatt_count;
}
static void att_enhanced_connection_work_handler(struct k_work *work)
{
const struct k_work_delayable *dwork = k_work_delayable_from_work(work);
const struct bt_att *att = CONTAINER_OF(dwork, struct bt_att, eatt.connection_work);
const int err = bt_eatt_connect(att->conn, att->eatt.chans_to_connect);
if (err == -ENOMEM) {
LOG_DBG("Failed to connect %d EATT channels, central has probably "
"already established some.",
att->eatt.chans_to_connect);
} else if (err < 0) {
LOG_WRN("Failed to connect %d EATT channels (err: %d)", att->eatt.chans_to_connect,
err);
}
}
#endif /* CONFIG_BT_EATT */
static int bt_att_accept(struct bt_conn *conn, struct bt_l2cap_chan **ch)
{
struct bt_att *att;
struct bt_att_chan *chan;
LOG_DBG("conn %p handle %u", conn, conn->handle);
if (k_mem_slab_alloc(&att_slab, (void **)&att, K_NO_WAIT)) {
LOG_ERR("No available ATT context for conn %p", conn);
return -ENOMEM;
}
att_handle_rsp_thread = k_current_get();
(void)memset(att, 0, sizeof(*att));
att->conn = conn;
sys_slist_init(&att->reqs);
sys_slist_init(&att->chans);
#if defined(CONFIG_BT_EATT)
k_work_init_delayable(&att->eatt.connection_work,
att_enhanced_connection_work_handler);
#endif /* CONFIG_BT_EATT */
chan = att_chan_new(att, 0);
if (!chan) {
return -ENOMEM;
}
*ch = &chan->chan.chan;
return 0;
}
/* The L2CAP channel section is sorted lexicographically. Make sure that ATT fixed channel will be
* placed as the last one to ensure that SMP channel is properly initialized before bt_att_connected
* tries to send security request.
*/
BT_L2CAP_CHANNEL_DEFINE(z_att_fixed_chan, BT_L2CAP_CID_ATT, bt_att_accept, NULL);
#if defined(CONFIG_BT_EATT)
static k_timeout_t credit_based_connection_delay(struct bt_conn *conn)
{
/*
* 5.3 Vol 3, Part G, Section 5.4 L2CAP COLLISION MITIGATION
* ... In this situation, the Central may retry
* immediately but the Peripheral shall wait a minimum of 100 ms before retrying;
* on LE connections, the Peripheral shall wait at least 2 *
* (connPeripheralLatency + 1) * connInterval if that is longer.
*/
if (IS_ENABLED(CONFIG_BT_CENTRAL) && conn->role == BT_CONN_ROLE_CENTRAL) {
return K_NO_WAIT;
} else if (IS_ENABLED(CONFIG_BT_PERIPHERAL)) {
uint8_t random;
int err;
err = bt_rand(&random, sizeof(random));
if (err) {
random = 0;
}
const uint8_t rand_delay = random & 0x7; /* Small random delay for IOP */
/* The maximum value of (latency + 1) * 2 multipled with the
* maximum connection interval has a maximum value of
* 4000000000 which can be stored in 32-bits, so this won't
* result in an overflow
*/
const uint32_t calculated_delay_us =
2 * (conn->le.latency + 1) * BT_CONN_INTERVAL_TO_US(conn->le.interval);
const uint32_t calculated_delay_ms = calculated_delay_us / USEC_PER_MSEC;
return K_MSEC(MAX(100, calculated_delay_ms + rand_delay));
}
/* Must be either central or peripheral */
__ASSERT_NO_MSG(false);
CODE_UNREACHABLE;
}
static int att_schedule_eatt_connect(struct bt_conn *conn, uint8_t chans_to_connect)
{
struct bt_att *att = att_get(conn);
if (!att) {
return -ENOTCONN;
}
att->eatt.chans_to_connect = chans_to_connect;
return k_work_reschedule(&att->eatt.connection_work,
credit_based_connection_delay(conn));
}
static void handle_potential_collision(struct bt_att *att)
{
__ASSERT_NO_MSG(att);
int err;
size_t to_connect = att->eatt.prev_conn_req_missing_chans;
if (att->eatt.prev_conn_rsp_result == BT_L2CAP_LE_ERR_NO_RESOURCES &&
att->eatt.prev_conn_req_result == BT_L2CAP_LE_ERR_NO_RESOURCES) {
LOG_DBG("Credit based connection request collision detected");
/* Reset to not keep retrying on repeated failures */
att->eatt.prev_conn_rsp_result = 0;
att->eatt.prev_conn_req_result = 0;
att->eatt.prev_conn_req_missing_chans = 0;
if (to_connect == 0) {
return;
}
err = att_schedule_eatt_connect(att->conn, to_connect);
if (err < 0) {
LOG_ERR("Failed to schedule EATT connection retry (err: %d)", err);
}
}
}
static void ecred_connect_req_cb(struct bt_conn *conn, uint16_t result, uint16_t psm)
{
struct bt_att *att = att_get(conn);
if (!att) {
return;
}
if (psm != BT_EATT_PSM) {
/* Collision mitigation is only a requirement on the EATT PSM */
return;
}
att->eatt.prev_conn_rsp_result = result;
handle_potential_collision(att);
}
static void ecred_connect_rsp_cb(struct bt_conn *conn, uint16_t result,
uint8_t attempted_to_connect, uint8_t succeeded_to_connect,
uint16_t psm)
{
struct bt_att *att = att_get(conn);
if (!att) {
return;
}
if (psm != BT_EATT_PSM) {
/* Collision mitigation is only a requirement on the EATT PSM */
return;
}
att->eatt.prev_conn_req_result = result;
att->eatt.prev_conn_req_missing_chans =
attempted_to_connect - succeeded_to_connect;
handle_potential_collision(att);
}
int bt_eatt_connect(struct bt_conn *conn, size_t num_channels)
{
struct bt_att_chan *att_chan;
struct bt_att *att;
struct bt_l2cap_chan *chan[CONFIG_BT_EATT_MAX + 1] = {};
size_t offset = 0;
size_t i = 0;
int err;
/* Check the encryption level for EATT */
if (bt_conn_get_security(conn) < BT_SECURITY_L2) {
/* Vol 3, Part G, Section 5.3.2 Channel Requirements states:
* The channel shall be encrypted.
*/
return -EPERM;
}
if (num_channels > CONFIG_BT_EATT_MAX || num_channels == 0) {
return -EINVAL;
}
if (!conn) {
return -EINVAL;
}
att_chan = att_get_fixed_chan(conn);
att = att_chan->att;
while (num_channels--) {
att_chan = att_chan_new(att, BIT(ATT_ENHANCED));
if (!att_chan) {
break;
}
chan[i] = &att_chan->chan.chan;
i++;
}
if (!i) {
return -ENOMEM;
}
while (offset < i) {
/* bt_l2cap_ecred_chan_connect() uses the first L2CAP_ECRED_CHAN_MAX_PER_REQ
* elements of the array or until a null-terminator is reached.
*/
err = bt_l2cap_ecred_chan_connect(conn, &chan[offset], BT_EATT_PSM);
if (err < 0) {
return err;
}
offset += L2CAP_ECRED_CHAN_MAX_PER_REQ;
}
return 0;
}
#if defined(CONFIG_BT_EATT_AUTO_CONNECT)
static void eatt_auto_connect(struct bt_conn *conn, bt_security_t level,
enum bt_security_err err)
{
int eatt_err;
if (err || level < BT_SECURITY_L2 || !bt_att_fixed_chan_only(conn)) {
return;
}
eatt_err = att_schedule_eatt_connect(conn, CONFIG_BT_EATT_MAX);
if (eatt_err < 0) {
LOG_WRN("Automatic creation of EATT bearers failed on "
"connection %s with error %d",
bt_addr_le_str(bt_conn_get_dst(conn)), eatt_err);
}
}
BT_CONN_CB_DEFINE(conn_callbacks) = {
.security_changed = eatt_auto_connect,
};
#endif /* CONFIG_BT_EATT_AUTO_CONNECT */
int bt_eatt_disconnect(struct bt_conn *conn)
{
struct bt_att_chan *chan;
struct bt_att *att;
int err = -ENOTCONN;
if (!conn) {
return -EINVAL;
}
chan = att_get_fixed_chan(conn);
att = chan->att;
SYS_SLIST_FOR_EACH_CONTAINER(&att->chans, chan, node) {
if (bt_att_is_enhanced(chan)) {
err = bt_l2cap_chan_disconnect(&chan->chan.chan);
}
}
return err;
}
#if defined(CONFIG_BT_TESTING)
int bt_eatt_disconnect_one(struct bt_conn *conn)
{
struct bt_att_chan *chan = att_get_fixed_chan(conn);
struct bt_att *att = chan->att;
int err = -ENOTCONN;
if (!conn) {
return -EINVAL;
}
SYS_SLIST_FOR_EACH_CONTAINER(&att->chans, chan, node) {
if (bt_att_is_enhanced(chan)) {
err = bt_l2cap_chan_disconnect(&chan->chan.chan);
return err;
}
}
return err;
}
int bt_eatt_reconfigure(struct bt_conn *conn, uint16_t mtu)
{
struct bt_att_chan *att_chan = att_get_fixed_chan(conn);
struct bt_att *att = att_chan->att;
struct bt_l2cap_chan *chans[CONFIG_BT_EATT_MAX + 1] = {};
size_t offset = 0;
size_t i = 0;
int err;
SYS_SLIST_FOR_EACH_CONTAINER(&att->chans, att_chan, node) {
if (bt_att_is_enhanced(att_chan)) {
chans[i] = &att_chan->chan.chan;
i++;
}
}
while (offset < i) {
/* bt_l2cap_ecred_chan_reconfigure() uses the first L2CAP_ECRED_CHAN_MAX_PER_REQ
* elements of the array or until a null-terminator is reached.
*/
err = bt_l2cap_ecred_chan_reconfigure(&chans[offset], mtu);
if (err < 0) {
return err;
}
offset += L2CAP_ECRED_CHAN_MAX_PER_REQ;
}
return 0;
}
#endif /* CONFIG_BT_TESTING */
#endif /* CONFIG_BT_EATT */
static int bt_eatt_accept(struct bt_conn *conn, struct bt_l2cap_server *server,
struct bt_l2cap_chan **chan)
{
struct bt_att_chan *att_chan = att_get_fixed_chan(conn);
struct bt_att *att = att_chan->att;
LOG_DBG("conn %p handle %u", conn, conn->handle);
att_chan = att_chan_new(att, BIT(ATT_ENHANCED));
if (att_chan) {
*chan = &att_chan->chan.chan;
return 0;
}
return -ENOMEM;
}
static void bt_eatt_init(void)
{
int err;
static struct bt_l2cap_server eatt_l2cap = {
.psm = BT_EATT_PSM,
.sec_level = BT_SECURITY_L2,
.accept = bt_eatt_accept,
};
struct bt_l2cap_server *registered_server;
LOG_DBG("");
/* Check if eatt_l2cap server has already been registered. */
registered_server = bt_l2cap_server_lookup_psm(eatt_l2cap.psm);
if (registered_server != &eatt_l2cap) {
err = bt_l2cap_server_register(&eatt_l2cap);
if (err < 0) {
LOG_ERR("EATT Server registration failed %d", err);
}
}
#if defined(CONFIG_BT_EATT)
static const struct bt_l2cap_ecred_cb cb = {
.ecred_conn_rsp = ecred_connect_rsp_cb,
.ecred_conn_req = ecred_connect_req_cb,
};
bt_l2cap_register_ecred_cb(&cb);
#endif /* CONFIG_BT_EATT */
}
void bt_att_init(void)
{
bt_gatt_init();
if (IS_ENABLED(CONFIG_BT_EATT)) {
bt_eatt_init();
}
}
uint16_t bt_att_get_mtu(struct bt_conn *conn)
{
struct bt_att_chan *chan, *tmp;
struct bt_att *att;
uint16_t mtu = 0;
att = att_get(conn);
if (!att) {
return 0;
}
SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&att->chans, chan, tmp, node) {
if (bt_att_mtu(chan) > mtu) {
mtu = bt_att_mtu(chan);
}
}
return mtu;
}
static void att_chan_mtu_updated(struct bt_att_chan *updated_chan)
{
struct bt_att *att = updated_chan->att;
struct bt_att_chan *chan, *tmp;
uint16_t max_tx = 0, max_rx = 0;
/* Get maximum MTU's of other channels */
SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&att->chans, chan, tmp, node) {
if (chan == updated_chan) {
continue;
}
max_tx = MAX(max_tx, chan->chan.tx.mtu);
max_rx = MAX(max_rx, chan->chan.rx.mtu);
}
/* If either maximum MTU has changed */
if ((updated_chan->chan.tx.mtu > max_tx) ||
(updated_chan->chan.rx.mtu > max_rx)) {
max_tx = MAX(max_tx, updated_chan->chan.tx.mtu);
max_rx = MAX(max_rx, updated_chan->chan.rx.mtu);
bt_gatt_att_max_mtu_changed(att->conn, max_tx, max_rx);
}
}
struct bt_att_req *bt_att_req_alloc(k_timeout_t timeout)
{
struct bt_att_req *req = NULL;
if (k_current_get() == att_handle_rsp_thread) {
/* No req will be fulfilled while blocking on the bt_recv thread.
* Blocking would cause deadlock.
*/
timeout = K_NO_WAIT;
}
/* Reserve space for request */
if (k_mem_slab_alloc(&req_slab, (void **)&req, timeout)) {
LOG_DBG("No space for req");
return NULL;
}
LOG_DBG("req %p", req);
memset(req, 0, sizeof(*req));
return req;
}
void bt_att_req_free(struct bt_att_req *req)
{
LOG_DBG("req %p", req);
if (req->buf) {
net_buf_unref(req->buf);
req->buf = NULL;
}
k_mem_slab_free(&req_slab, (void *)req);
}
int bt_att_send(struct bt_conn *conn, struct net_buf *buf)
{
struct bt_att *att;
__ASSERT_NO_MSG(conn);
__ASSERT_NO_MSG(buf);
att = att_get(conn);
if (!att) {
net_buf_unref(buf);
return -ENOTCONN;
}
net_buf_put(&att->tx_queue, buf);
att_send_process(att);
return 0;
}
int bt_att_req_send(struct bt_conn *conn, struct bt_att_req *req)
{
struct bt_att *att;
LOG_DBG("conn %p req %p", conn, req);
__ASSERT_NO_MSG(conn);
__ASSERT_NO_MSG(req);
att = att_get(conn);
if (!att) {
return -ENOTCONN;
}
sys_slist_append(&att->reqs, &req->node);
att_req_send_process(att);
return 0;
}
static bool bt_att_chan_req_cancel(struct bt_att_chan *chan,
struct bt_att_req *req)
{
if (chan->req != req) {
return false;
}
chan->req = &cancel;
bt_att_req_free(req);
return true;
}
void bt_att_req_cancel(struct bt_conn *conn, struct bt_att_req *req)
{
struct bt_att *att;
struct bt_att_chan *chan, *tmp;
LOG_DBG("req %p", req);
if (!conn || !req) {
return;
}
att = att_get(conn);
if (!att) {
return;
}
SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&att->chans, chan, tmp, node) {
/* Check if request is outstanding */
if (bt_att_chan_req_cancel(chan, req)) {
return;
}
}
/* Remove request from the list */
sys_slist_find_and_remove(&att->reqs, &req->node);
bt_att_req_free(req);
}
struct bt_att_req *bt_att_find_req_by_user_data(struct bt_conn *conn, const void *user_data)
{
struct bt_att *att;
struct bt_att_chan *chan;
struct bt_att_req *req;
att = att_get(conn);
if (!att) {
return NULL;
}
SYS_SLIST_FOR_EACH_CONTAINER(&att->chans, chan, node) {
if (chan->req->user_data == user_data) {
return chan->req;
}
}
SYS_SLIST_FOR_EACH_CONTAINER(&att->reqs, req, node) {
if (req->user_data == user_data) {
return req;
}
}
return NULL;
}
bool bt_att_fixed_chan_only(struct bt_conn *conn)
{
#if defined(CONFIG_BT_EATT)
return bt_eatt_count(conn) == 0;
#else
return true;
#endif /* CONFIG_BT_EATT */
}
void bt_att_clear_out_of_sync_sent(struct bt_conn *conn)
{
struct bt_att *att = att_get(conn);
struct bt_att_chan *chan;
if (!att) {
return;
}
SYS_SLIST_FOR_EACH_CONTAINER(&att->chans, chan, node) {
atomic_clear_bit(chan->flags, ATT_OUT_OF_SYNC_SENT);
}
}
bool bt_att_out_of_sync_sent_on_fixed(struct bt_conn *conn)
{
struct bt_l2cap_chan *l2cap_chan;
struct bt_att_chan *att_chan;
l2cap_chan = bt_l2cap_le_lookup_rx_cid(conn, BT_L2CAP_CID_ATT);
if (!l2cap_chan) {
return false;
}
att_chan = ATT_CHAN(l2cap_chan);
return atomic_test_bit(att_chan->flags, ATT_OUT_OF_SYNC_SENT);
}
void bt_att_set_tx_meta_data(struct net_buf *buf, bt_gatt_complete_func_t func, void *user_data,
enum bt_att_chan_opt chan_opt)
{
struct bt_att_tx_meta_data *data = bt_att_get_tx_meta_data(buf);
data->func = func;
data->user_data = user_data;
data->attr_count = 1;
data->chan_opt = chan_opt;
}
void bt_att_increment_tx_meta_data_attr_count(struct net_buf *buf, uint16_t attr_count)
{
struct bt_att_tx_meta_data *data = bt_att_get_tx_meta_data(buf);
data->attr_count += attr_count;
}
bool bt_att_tx_meta_data_match(const struct net_buf *buf, bt_gatt_complete_func_t func,
const void *user_data, enum bt_att_chan_opt chan_opt)
{
const struct bt_att_tx_meta_data *meta = bt_att_get_tx_meta_data(buf);
return ((meta->func == func) &&
(meta->user_data == user_data) &&
(meta->chan_opt == chan_opt));
}
bool bt_att_chan_opt_valid(struct bt_conn *conn, enum bt_att_chan_opt chan_opt)
{
if ((chan_opt & (BT_ATT_CHAN_OPT_ENHANCED_ONLY | BT_ATT_CHAN_OPT_UNENHANCED_ONLY)) ==
(BT_ATT_CHAN_OPT_ENHANCED_ONLY | BT_ATT_CHAN_OPT_UNENHANCED_ONLY)) {
/* Enhanced and Unenhanced are mutually exclusive */
return false;
}
/* Choosing EATT requires EATT channels connected and encryption enabled */
if (chan_opt & BT_ATT_CHAN_OPT_ENHANCED_ONLY) {
return (bt_conn_get_security(conn) > BT_SECURITY_L1) &&
!bt_att_fixed_chan_only(conn);
}
return true;
}
int bt_gatt_authorization_cb_register(const struct bt_gatt_authorization_cb *cb)
{
if (!IS_ENABLED(CONFIG_BT_GATT_AUTHORIZATION_CUSTOM)) {
return -ENOSYS;
}
if (!cb) {
authorization_cb = NULL;
return 0;
}
if (authorization_cb) {
return -EALREADY;
}
authorization_cb = cb;
return 0;
}