Bluetooth: controller: Only allow supported feature bits to be set by host

Redefine mask of host-controlled feature bits to include only features
that are supported by the controller. This fixes a conformance test
failure where setting an unsupported host-controlled feature bit was
not rejected as it should.

Set the Connected Isochronous Streams (Host Support) bit from the host
only if unicast support is configured to avoid failures in
broadcast-only configurations.

Signed-off-by: Wolfgang Puffitsch <[email protected]>

Author: wopu-ot

subsys/bluetooth/controller/include/ll_feat.h

@@ -243,9 +243,6 @@
 /* Mask to filter away octet 0 for feature exchange */
 #define LL_FEAT_FILTER_OCTET0    (LL_FEAT_BIT_MASK & ~0xFFULL)
 
-/* Mask for host controlled features */
-#define LL_FEAT_HOST_BIT_MASK    0x4100000000ULL
-
 /* Feature bits of this controller */
 #define LL_FEAT                  (LL_FEAT_BIT_ENC | \
 				  LL_FEAT_BIT_CONN_PARAM_REQ | \
@@ -276,3 +273,17 @@
 				  LL_FEAT_BIT_ISO_BROADCASTER | \
 				  LL_FEAT_BIT_SYNC_RECEIVER | \
 				  LL_FEAT_BIT_PERIODIC_ADI_SUPPORT)
+
+/* Connected Isochronous Stream (Host Support) bit is controlled by host */
+#if defined(CONFIG_BT_CTLR_CONN_ISO)
+#define LL_FEAT_HOST_BITS_ISO_CHANNELS BIT64(BT_LE_FEAT_BIT_ISO_CHANNELS)
+#else /* !CONFIG_BT_CTLR_CONN_ISO */
+#define LL_FEAT_HOST_BITS_ISO_CHANNELS 0U
+#endif /* !CONFIG_BT_CTLR_CONN_ISO */
+
+/* Connection subrating not supported and bit thus cannot be set by host */
+#define LL_FEAT_HOST_BITS_CONN_SUBRATING 0U
+
+/* Mask for host controlled features */
+#define LL_FEAT_HOST_BIT_MASK  (LL_FEAT_HOST_BITS_ISO_CHANNELS |\
+				LL_FEAT_HOST_BITS_CONN_SUBRATING)

subsys/bluetooth/host/hci_core.c

@@ -2894,10 +2894,12 @@ static int le_init_iso(void)
 	int err;
 	struct net_buf *rsp;
 
-	/* Set Isochronous Channels - Host support */
-	err = le_set_host_feature(BT_LE_FEAT_BIT_ISO_CHANNELS, 1);
-	if (err) {
-		return err;
+	if (IS_ENABLED(CONFIG_BT_ISO_UNICAST)) {
+		/* Set Connected Isochronous Streams - Host support */
+		err = le_set_host_feature(BT_LE_FEAT_BIT_ISO_CHANNELS, 1);
+		if (err) {
+			return err;
+		}
 	}
 
 	/* Octet 41, bit 5 is read buffer size V2 */