[PATCH] Bluetooth: rfcomm: Accept any XON/XOFF char

["Frédéric Danis" <frederic.danis@collabora.com>]

The latest version of PTS test RFCOMM/DEVA-DEVB/RFC/BV-17-C
(RFCOMM v11.7.6.3) used unusual chars for XON (0x28 instead of
0x11) and XOFF (0xC8 instead of 0x13) and expect a reply with RPN
parameters set for XON and XOFF.

Current btmon traces:
> ACL Data RX: Handle 11 flags 0x02 dlen 18
      Channel: 64 len 14 [PSM 3 mode Basic (0x00)] {chan 0}
      RFCOMM: Unnumbered Info with Header Check (UIH) (0xef)
         Address: 0x03 cr 1 dlci 0x00
         Control: 0xef poll/final 0
         Length: 10
         FCS: 0x70
         MCC Message type: Remote Port Negotiation Command CMD (0x24)
           Length: 8
           dlci 32
           br 3 db 3 sb 0 p 0 pt 0 xi 0 xo 0
           rtri 0 rtro 0 rtci 0 rtco 0 xon 40 xoff 200
           pm 0xff7f
< ACL Data TX: Handle 11 flags 0x00 dlen 18
      Channel: 64 len 14 [PSM 3 mode Basic (0x00)] {chan 0}
      RFCOMM: Unnumbered Info with Header Check (UIH) (0xef)
         Address: 0x01 cr 0 dlci 0x00
         Control: 0xef poll/final 0
         Length: 10
         FCS: 0xaa
         MCC Message type: Remote Port Negotiation Command RSP (0x24)
           Length: 8
           dlci 32
           br 3 db 3 sb 0 p 0 pt 0 xi 0 xo 0
           rtri 0 rtro 0 rtci 0 rtco 0 xon 17 xoff 19
           pm 0x3f1f

Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>
---
 net/bluetooth/rfcomm/core.c | 20 ++++++--------------
 1 file changed, 6 insertions(+), 14 deletions(-)

diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index ad5177e3a69b..0c0525939aa0 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -1562,23 +1562,15 @@ static int rfcomm_recv_rpn(struct rfcomm_session *s, int cr, int len, struct sk_
 		}
 	}
 
-	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_XON)) {
+	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_XON))
 		xon_char = rpn->xon_char;
-		if (xon_char != RFCOMM_RPN_XON_CHAR) {
-			BT_DBG("RPN XON char mismatch 0x%x", xon_char);
-			xon_char = RFCOMM_RPN_XON_CHAR;
-			rpn_mask ^= RFCOMM_RPN_PM_XON;
-		}
-	}
+	else
+		rpn_mask ^= RFCOMM_RPN_PM_XON;
 
-	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_XOFF)) {
+	if (rpn->param_mask & cpu_to_le16(RFCOMM_RPN_PM_XOFF))
 		xoff_char = rpn->xoff_char;
-		if (xoff_char != RFCOMM_RPN_XOFF_CHAR) {
-			BT_DBG("RPN XOFF char mismatch 0x%x", xoff_char);
-			xoff_char = RFCOMM_RPN_XOFF_CHAR;
-			rpn_mask ^= RFCOMM_RPN_PM_XOFF;
-		}
-	}
+	else
+		rpn_mask ^= RFCOMM_RPN_PM_XOFF;
 
 rpn_out:
 	rfcomm_send_rpn(s, 0, dlci, bit_rate, data_bits, stop_bits,
-- 
2.43.0