Bluetooth: Get a more accurate L2CAP PDU len
Both FCS and Extended header might be or might not be present in a ERTM
channel.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 6eb2ef2..155aa50 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -2130,7 +2130,13 @@
pdu_len = min_t(size_t, pdu_len, L2CAP_BREDR_MAX_PAYLOAD);
/* Adjust for largest possible L2CAP overhead. */
- pdu_len -= L2CAP_EXT_HDR_SIZE + L2CAP_FCS_SIZE;
+ if (chan->fcs)
+ pdu_len -= L2CAP_FCS_SIZE;
+
+ if (test_bit(FLAG_EXT_CTRL, &chan->flags))
+ pdu_len -= L2CAP_EXT_HDR_SIZE;
+ else
+ pdu_len -= L2CAP_ENH_HDR_SIZE;
/* Remote device may have requested smaller PDUs */
pdu_len = min_t(size_t, pdu_len, chan->remote_mps);