Bluetooth: Allow 3D profile to use security mode 4 level 0

The PSM 0x0021 is dedicated to the 3D profile and has permission to
use security mode 4 level 0 for L2CAP connectionless unicast data
transfers.

When establishing a L2CAP connectionless channel on PSM 0x0021, it
will no longer force Secure Simple Pairing.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index bee98eb..bd6fe7f 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -101,6 +101,10 @@
 		goto done;
 
 	switch (chan->chan_type) {
+	case L2CAP_CHAN_CONN_LESS:
+		if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_3DSP)
+			chan->sec_level = BT_SECURITY_SDP;
+		break;
 	case L2CAP_CHAN_CONN_ORIENTED:
 		if (__le16_to_cpu(la.l2_psm) == L2CAP_PSM_SDP ||
 		    __le16_to_cpu(la.l2_psm) == L2CAP_PSM_RFCOMM)