Bluetooth: ISO: Add broadcast support

This adds broadcast support for BTPROTO_ISO by extending the
sockaddr_iso with a new struct sockaddr_iso_bc where the socket user
can set the broadcast address when receiving, the SID and the BIS
indexes it wants to synchronize.

When using BTPROTO_ISO for broadcast the roles are:

Broadcaster -> uses connect with address set to BDADDR_ANY:
> tools/isotest -s 00:00:00:00:00:00

Broadcast Receiver -> uses listen with address set to broadcaster:
> tools/isotest -d 00:AA:01:00:00:00
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

include/net/bluetooth/bluetooth.h

@@ -220,6 +220,8 @@ struct bt_codecs {
 #define BT_CODEC_TRANSPARENT	0x03
 #define BT_CODEC_MSBC		0x05
 
+#define BT_ISO_BASE		20
+
 __printf(1, 2)
 void bt_info(const char *fmt, ...);
 __printf(1, 2)

include/net/bluetooth/iso.h

@@ -10,12 +10,23 @@
 
 /* ISO defaults */
 #define ISO_DEFAULT_MTU		251
+#define ISO_MAX_NUM_BIS		0x1f
+
+/* ISO socket broadcast address */
+struct sockaddr_iso_bc {
+	bdaddr_t	bc_bdaddr;
+	__u8		bc_bdaddr_type;
+	__u8		bc_sid;
+	__u8		bc_num_bis;
+	__u8		bc_bis[ISO_MAX_NUM_BIS];
+};
 
 /* ISO socket address */
 struct sockaddr_iso {
 	sa_family_t	iso_family;
 	bdaddr_t	iso_bdaddr;
 	__u8		iso_bdaddr_type;
+	struct sockaddr_iso_bc iso_bc[];
 };
 
 #endif /* __ISO_H */