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Bluetooth: Add basic L2CAP support

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This patch adds basic L2CAP functions, including support for the LE
signaling channel as well as performing a connection parameter update
in slave (peripheral) role.

Change-Id: Ie1f9751475adcf26576e9587bf6d68d15d6a2569
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This commit is contained in:
Johan Hedberg 2015-04-28 10:43:14 +03:00 • committed by Anas Nashif
commit c31237aa82
3 changed files with 212 additions and 1 deletions
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4
net/bluetooth/conn.c
View file

@ -166,7 +166,7 @@ static void conn_rx_fiber(int arg1, int arg2)
break;
}
bt_buf_put(buf);
bt_l2cap_recv(conn, buf);
}
BT_DBG("handle %u disconnected - cleaning up\n", conn->handle);
@ -252,6 +252,8 @@ struct bt_conn *bt_conn_add(struct bt_dev *dev, uint16_t handle)
fiber_start(conn->tx_stack, BT_CONN_TX_STACK_SIZE, conn_tx_fiber,
(int)bt_conn_get(conn), 0, 7, 0);
bt_l2cap_update_conn_param(conn);
return conn;
}

176
net/bluetooth/l2cap.c Normal file
View file

@ -0,0 +1,176 @@
#include <nanokernel.h>
#include <toolchain.h>
#include <string.h>
#include <errno.h>
#include <misc/byteorder.h>
#include <bluetooth/hci.h>
#include <bluetooth/bluetooth.h>
#include "hci_core.h"
#include "conn.h"
#include "l2cap.h"
#define LE_CONN_MIN_INTERVAL 0x0028
#define LE_CONN_MAX_INTERVAL 0x0038
#define LE_CONN_LATENCY 0x0000
#define LE_CONN_TIMEOUT 0x002a
static uint8_t get_ident(struct bt_conn *conn)
{
conn->l2_ident++;
/* handle integer overflow (0 is not valid) */
if (!conn->l2_ident)
conn->l2_ident++;
return conn->l2_ident;
}
struct bt_buf *bt_l2cap_create_pdu(struct bt_conn *conn, uint16_t cid,
size_t len)
{
struct bt_l2cap_hdr *hdr;
struct bt_buf *buf;
buf = bt_conn_create_pdu(conn, sizeof(*hdr) + len);
if (!buf)
return NULL;
hdr = (void *)bt_buf_add(buf, sizeof(*hdr));
hdr->len = sys_cpu_to_le16(len);
hdr->cid = sys_cpu_to_le16(cid);
return buf;
}
static void rej_not_understood(struct bt_conn *conn, uint8_t ident)
{
struct bt_l2cap_cmd_reject *rej;
struct bt_l2cap_sig_hdr *hdr;
struct bt_buf *buf;
buf = bt_l2cap_create_pdu(conn, BT_L2CAP_CID_LE_SIG,
sizeof(*hdr) + sizeof(*rej));
if (!buf)
return;
hdr = (void *)bt_buf_add(buf, sizeof(*hdr));
hdr->code = BT_L2CAP_CMD_REJECT;
hdr->ident = ident;
hdr->len = sys_cpu_to_le16(sizeof(*rej));
rej = (void *)bt_buf_add(buf, sizeof(*rej));
rej->reason = sys_cpu_to_le16(BT_L2CAP_REJ_NOT_UNDERSTOOD);
bt_conn_send(conn, buf);
}
static void le_conn_param_rsp(struct bt_conn *conn, struct bt_buf *buf)
{
struct bt_l2cap_conn_param_rsp *rsp = (void *)buf->data;
if (buf->len < sizeof(*rsp)) {
BT_ERR("Too small LE conn param rsp\n");
return;
}
BT_DBG("LE conn param rsp result %u\n", sys_le16_to_cpu(rsp->result));
}
static void le_sig(struct bt_conn *conn, struct bt_buf *buf)
{
struct bt_l2cap_sig_hdr *hdr = (void *)buf->data;
uint16_t len;
if (buf->len < sizeof(*hdr)) {
BT_ERR("Too small L2CAP LE signaling PDU\n");
goto drop;
}
len = sys_le16_to_cpu(hdr->len);
bt_buf_pull(buf, sizeof(*hdr));
BT_DBG("LE signaling code %u ident %u len %u\n", hdr->code,
hdr->ident, len);
if (buf->len != len) {
BT_ERR("L2CAP length mismatch (%u != %u)\n", buf->len, len);
goto drop;
}
if (!hdr->ident) {
BT_ERR("Invalid ident value in L2CAP PDU\n");
goto drop;
}
switch (hdr->code) {
case BT_L2CAP_CONN_PARAM_RSP:
le_conn_param_rsp(conn, buf);
break;
default:
BT_ERR("Unknown L2CAP PDU code %u\n", hdr->code);
rej_not_understood(conn, hdr->ident);
break;
}
drop:
bt_buf_put(buf);
}
void bt_l2cap_recv(struct bt_conn *conn, struct bt_buf *buf)
{
struct bt_l2cap_hdr *hdr = (void *)buf->data;
uint16_t cid;
if (buf->len < sizeof(*hdr)) {
BT_ERR("Too small L2CAP PDU received\n");
bt_buf_put(buf);
return;
}
cid = sys_le16_to_cpu(hdr->cid);
bt_buf_pull(buf, sizeof(*hdr));
BT_DBG("Packet for CID %u len %u\n", cid, buf->len);
switch (cid) {
case BT_L2CAP_CID_LE_SIG:
le_sig(conn, buf);
break;
default:
BT_ERR("Ignoring data for unknown CID %u\n", cid);
bt_buf_put(buf);
break;
}
}
void bt_l2cap_update_conn_param(struct bt_conn *conn)
{
struct bt_l2cap_sig_hdr *hdr;
struct bt_l2cap_conn_param_req *req;
struct bt_buf *buf;
/* Check if we need to update anything */
if (conn->le_conn_interval >= LE_CONN_MIN_INTERVAL &&
conn->le_conn_interval <= LE_CONN_MAX_INTERVAL)
return;
buf = bt_l2cap_create_pdu(conn, BT_L2CAP_CID_LE_SIG,
sizeof(*hdr) + sizeof(*req));
if (!buf)
return;
hdr = (void *)bt_buf_add(buf, sizeof(*hdr));
hdr->code = BT_L2CAP_CONN_PARAM_REQ;
hdr->ident = get_ident(conn);
hdr->len = sys_cpu_to_le16(sizeof(*req));
req = (void *)bt_buf_add(buf, sizeof(*req));
req->min_interval = sys_cpu_to_le16(LE_CONN_MIN_INTERVAL);
req->max_interval = sys_cpu_to_le16(LE_CONN_MAX_INTERVAL);
req->latency = sys_cpu_to_le16(LE_CONN_LATENCY);
req->timeout = sys_cpu_to_le16(LE_CONN_TIMEOUT);
bt_conn_send(conn, buf);
}

33
net/bluetooth/l2cap.h
View file

@ -43,3 +43,36 @@ struct bt_l2cap_sig_hdr {
uint8_t ident;
uint16_t len;
} PACK_STRUCT;
#define BT_L2CAP_REJ_NOT_UNDERSTOOD 0x0000
#define BT_L2CAP_REJ_MTU_EXCEEDED 0x0001
#define BT_L2CAP_REJ_INVALID_CID 0x0002
#define BT_L2CAP_CMD_REJECT 0x01
struct bt_l2cap_cmd_reject {
uint16_t reason;
uint8_t data[0];
} PACK_STRUCT;
#define BT_L2CAP_CONN_PARAM_REQ 0x12
struct bt_l2cap_conn_param_req {
uint16_t min_interval;
uint16_t max_interval;
uint16_t latency;
uint16_t timeout;
} PACK_STRUCT;
#define BT_L2CAP_CONN_PARAM_RSP 0x13
struct bt_l2cap_conn_param_rsp {
uint16_t result;
} PACK_STRUCT;
/* Prepare an L2CAP PDU to be sent over a connection */
struct bt_buf *bt_l2cap_create_pdu(struct bt_conn *conn, uint16_t cid,
size_t len);
/* Receive a new L2CAP PDU from a connection */
void bt_l2cap_recv(struct bt_conn *conn, struct bt_buf *buf);
/* Perform connection parameter update request */
void bt_l2cap_update_conn_param(struct bt_conn *conn);