[PATCH] isotp: do not validate RX address when the broadcast flag is active

[Thomseeen <thwa1@web.de>]

EADDRNOTAVAIL shouldn't be thrown when an invalid RX address (e.g. NO_CAN_ID)
is set while the socket is used with the CAN_ISOTP_SF_BROADCAST flag.

Signed-off-by: Thomseeen <thwa1@web.de>
---
 net/can/isotp.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/net/can/isotp.c b/net/can/isotp.c
index fb6dba1..ae939bf 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1106,20 +1106,25 @@ static int isotp_bind(struct socket *sock, struct sockaddr *uaddr, int len)
 #endif
 		return -EINVAL;

-	if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id)
-		return -EADDRNOTAVAIL;
+	/* do not register frame reception for functional addressing */
+	if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
+		do_rx_reg = 0;
+
+	/* do not validate rx address for functional addressing */
+	if (do_rx_reg) {
+		if (addr->can_addr.tp.rx_id == addr->can_addr.tp.tx_id)
+			return -EADDRNOTAVAIL;

-	if ((addr->can_addr.tp.rx_id | addr->can_addr.tp.tx_id) &
-	    (CAN_ERR_FLAG | CAN_RTR_FLAG))
+		if (addr->can_addr.tp.rx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))
+			return -EADDRNOTAVAIL;
+	}
+
+	if (addr->can_addr.tp.tx_id & (CAN_ERR_FLAG | CAN_RTR_FLAG))
 		return -EADDRNOTAVAIL;

 	if (!addr->can_ifindex)
 		return -ENODEV;

-	/* do not register frame reception for functional addressing */
-	if (so->opt.flags & CAN_ISOTP_SF_BROADCAST)
-		do_rx_reg = 0;
-
 	lock_sock(sk);

 	if (so->bound && addr->can_ifindex == so->ifindex &&
--
2.25.1