net: vrf: Add support for sends to local broadcast address

Sukumar reported that sends to the local broadcast address
(255.255.255.255) are broken. Check for the address in vrf driver
and do not redirect to the VRF device - similar to multicast
packets.

With this change sockets can use SO_BINDTODEVICE to specify an
egress interface and receive responses. Note: the egress interface
can not be a VRF device but needs to be the enslaved device.

https://bugzilla.kernel.org/show_bug.cgi?id=198521

Reported-by: Sukumar Gopalakrishnan <sukumarg1973@gmail.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index feb1b2e15c2e10676ff43cec39291e3e9791a51d..139c61c8244ad9099ed8d6377b74eff446354e10 100644 (file)
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -673,8 +673,9 @@ static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
                                  struct sock *sk,
                                  struct sk_buff *skb)
 {
-       /* don't divert multicast */
-       if (ipv4_is_multicast(ip_hdr(skb)->daddr))
+       /* don't divert multicast or local broadcast */
+       if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
+           ipv4_is_lbcast(ip_hdr(skb)->daddr))
                return skb;
 
        if (qdisc_tx_is_default(vrf_dev))