can: isotp: TX-path: ensure that CAN frame flags are initialized

The previous patch ensures that the TX flags (struct
can_isotp_ll_options::tx_flags) are 0 for classic CAN frames or a user
configured value for CAN-FD frames.

This patch sets the CAN frames flags unconditionally to the ISO-TP TX
flags, so that they are initialized to a proper value. Otherwise when
running "candump -x" on a classical CAN ISO-TP stream shows wrongly
set "B" and "E" flags.

| $ candump any,0:0,#FFFFFFFF -extA
| [...]
| can0  TX B E  713   [8]  2B 0A 0B 0C 0D 0E 0F 00
| can0  TX B E  713   [8]  2C 01 02 03 04 05 06 07
| can0  TX B E  713   [8]  2D 08 09 0A 0B 0C 0D 0E
| can0  TX B E  713   [8]  2E 0F 00 01 02 03 04 05

Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/r/20210218215434.1708249-2-mkl@pengutronix.de
Cc: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/net/can/isotp.c b/net/can/isotp.c
index e32d446..4309764 100644 (file)
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -215,8 +215,7 @@ static int isotp_send_fc(struct sock *sk, int ae, u8 flowstatus)
        if (ae)
                ncf->data[0] = so->opt.ext_address;
 
-       if (so->ll.mtu == CANFD_MTU)
-               ncf->flags = so->ll.tx_flags;
+       ncf->flags = so->ll.tx_flags;
 
        can_send_ret = can_send(nskb, 1);
        if (can_send_ret)
@@ -790,8 +789,7 @@ isotp_tx_burst:
                so->tx.sn %= 16;
                so->tx.bs++;
 
-               if (so->ll.mtu == CANFD_MTU)
-                       cf->flags = so->ll.tx_flags;
+               cf->flags = so->ll.tx_flags;
 
                skb->dev = dev;
                can_skb_set_owner(skb, sk);
@@ -939,8 +937,7 @@ static int isotp_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
        }
 
        /* send the first or only CAN frame */
-       if (so->ll.mtu == CANFD_MTU)
-               cf->flags = so->ll.tx_flags;
+       cf->flags = so->ll.tx_flags;
 
        skb->dev = dev;
        skb->sk = sk;