Bluetooth: Add helper to get HCI channel of a socket

We'll need to have access to which HCI channel a socket is bound to, in
order to manage pending mgmt commands in clean way. This patch adds a
helper for the purpose.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

include/net/bluetooth/bluetooth.h

@@ -338,6 +338,7 @@ int bt_to_errno(__u16 code);
 void hci_sock_set_flag(struct sock *sk, int nr);
 void hci_sock_clear_flag(struct sock *sk, int nr);
 int hci_sock_test_flag(struct sock *sk, int nr);
+unsigned short hci_sock_get_channel(struct sock *sk);
 
 int hci_sock_init(void);
 void hci_sock_cleanup(void);

net/bluetooth/hci_sock.c

@@ -65,6 +65,11 @@ int hci_sock_test_flag(struct sock *sk, int nr)
 	return test_bit(nr, &hci_pi(sk)->flags);
 }
 
+unsigned short hci_sock_get_channel(struct sock *sk)
+{
+	return hci_pi(sk)->channel;
+}
+
 static inline int hci_test_bit(int nr, const void *addr)
 {
 	return *((const __u32 *) addr + (nr >> 5)) & ((__u32) 1 << (nr & 31));