zephyr/subsys/mgmt/smp_bt.c

161 lines
3.6 KiB
C

/*
* Copyright Runtime.io 2018. All rights reserved.
*
* SPDX-License-Identifier: Apache-2.0
*/
/** @file
* @brief Bluetooth transport for the mcumgr SMP protocol.
*/
#include <errno.h>
#include <zephyr.h>
#include <init.h>
#include <bluetooth/bluetooth.h>
#include <bluetooth/uuid.h>
#include <bluetooth/gatt.h>
#include <mgmt/smp_bt.h>
#include <mgmt/buf.h>
#include <mgmt/smp.h>
struct device;
static struct zephyr_smp_transport smp_bt_transport;
/* SMP service.
* {8D53DC1D-1DB7-4CD3-868B-8A527460AA84}
*/
static struct bt_uuid_128 smp_bt_svc_uuid = BT_UUID_INIT_128(
0x84, 0xaa, 0x60, 0x74, 0x52, 0x8a, 0x8b, 0x86,
0xd3, 0x4c, 0xb7, 0x1d, 0x1d, 0xdc, 0x53, 0x8d);
/* SMP characteristic; used for both requests and responses.
* {DA2E7828-FBCE-4E01-AE9E-261174997C48}
*/
static struct bt_uuid_128 smp_bt_chr_uuid = BT_UUID_INIT_128(
0x48, 0x7c, 0x99, 0x74, 0x11, 0x26, 0x9e, 0xae,
0x01, 0x4e, 0xce, 0xfb, 0x28, 0x78, 0x2e, 0xda);
/**
* Write handler for the SMP characteristic; processes an incoming SMP request.
*/
static ssize_t smp_bt_chr_write(struct bt_conn *conn,
const struct bt_gatt_attr *attr,
const void *buf, u16_t len, u16_t offset,
u8_t flags)
{
const bt_addr_le_t *addr;
struct net_buf *nb;
nb = mcumgr_buf_alloc();
net_buf_add_mem(nb, buf, len);
addr = bt_conn_get_dst(conn);
memcpy(net_buf_user_data(nb), addr, sizeof(*addr));
zephyr_smp_rx_req(&smp_bt_transport, nb);
return len;
}
static void smp_bt_ccc_changed(const struct bt_gatt_attr *attr, u16_t value)
{
}
static struct bt_gatt_ccc_cfg smp_bt_ccc[BT_GATT_CCC_MAX] = {};
static struct bt_gatt_attr smp_bt_attrs[] = {
/* SMP Primary Service Declaration */
BT_GATT_PRIMARY_SERVICE(&smp_bt_svc_uuid),
BT_GATT_CHARACTERISTIC(&smp_bt_chr_uuid.uuid,
BT_GATT_CHRC_WRITE_WITHOUT_RESP |
BT_GATT_CHRC_NOTIFY),
BT_GATT_DESCRIPTOR(&smp_bt_chr_uuid.uuid,
BT_GATT_PERM_WRITE, NULL, smp_bt_chr_write, NULL),
BT_GATT_CCC(smp_bt_ccc, smp_bt_ccc_changed),
};
static struct bt_gatt_service smp_bt_svc = BT_GATT_SERVICE(smp_bt_attrs);
/**
* Transmits an SMP response over the specified Bluetooth connection.
*/
static int smp_bt_tx_rsp(struct bt_conn *conn, const void *data, u16_t len)
{
return bt_gatt_notify(conn, smp_bt_attrs + 2, data, len);
}
/**
* Extracts the peer address from a net_buf's user data and looks up the
* corresponding conection.
*/
static struct bt_conn *smp_bt_conn_from_pkt(const struct net_buf *nb)
{
bt_addr_le_t addr;
/* Cast away const. */
memcpy(&addr, net_buf_user_data((void *)nb), sizeof(addr));
return bt_conn_lookup_addr_le(&addr);
}
/**
* Calculates the maximum fragment size to use when sending the specified
* response packet.
*/
static u16_t smp_bt_get_mtu(const struct net_buf *nb)
{
struct bt_conn *conn;
u16_t mtu;
conn = smp_bt_conn_from_pkt(nb);
if (conn == NULL) {
return 0;
}
mtu = bt_gatt_get_mtu(conn);
bt_conn_unref(conn);
/* Account for the three-byte notification header. */
return mtu - 3;
}
/**
* Transmits the specified SMP response.
*/
static int smp_bt_tx_pkt(struct zephyr_smp_transport *zst, struct net_buf *nb)
{
struct bt_conn *conn;
int rc;
conn = smp_bt_conn_from_pkt(nb);
if (conn == NULL) {
rc = -1;
} else {
rc = smp_bt_tx_rsp(conn, nb->data, nb->len);
bt_conn_unref(conn);
}
mcumgr_buf_free(nb);
return rc;
}
int smp_bt_register(void)
{
return bt_gatt_service_register(&smp_bt_svc);
}
static int smp_bt_init(struct device *dev)
{
ARG_UNUSED(dev);
zephyr_smp_transport_init(&smp_bt_transport, smp_bt_tx_pkt,
smp_bt_get_mtu);
return 0;
}
SYS_INIT(smp_bt_init, APPLICATION, CONFIG_APPLICATION_INIT_PRIORITY);