There is not an easy way to relate an application's user_data to a
connection. One way is to save a pointer to bt_conn in the
application's user_data array upon connection establishment.
Each connection related callback function will have to loop for all
user_data and compare the saved pointer to the passed bt_conn
pointer. This is inefficient if there are many callback activations
during the connection.
This change makes the internal bt_conn mapping function accessible to
applications in conn.h. The function name is changed to
bt_conn_index() to clearly indicate that the function returns an
index of an array.
Add an ASSERT to catch illegal parameter.
Signed-off-by: Kim Sekkelund <ksek@oticon.com>
bf11698ed9