net: Enable support for VRF with ipv4 multicast
Enable support for IPv4 multicast:
- similar to unicast the flow struct is updated to L3 master device
if relevant prior to calling fib_rules_lookup. The table id is saved
to the lookup arg so the rule action for ipmr can return the table
associated with the device.
- ip_mr_forward needs to check for master device mismatch as well
since the skb->dev is set to it
- allow multicast address on VRF device for Rx by checking for the
daddr in the VRF device as well as the original ingress device
- on Tx need to drop to __mkroute_output when FIB lookup fails for
multicast destination address.
- if CONFIG_IP_MROUTE_MULTIPLE_TABLES is enabled VRF driver creates
IPMR FIB rules on first device create similar to FIB rules. In
addition the VRF driver does not divert IPv4 multicast packets:
it breaks on Tx since the fib lookup fails on the mcast address.
With this patch, ipmr forwarding and local rx/tx work.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 62d4d90..4392db8 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1980,25 +1980,35 @@ int ip_route_input_noref(struct sk_buff *skb, __be32 daddr, __be32 saddr,
*/
if (ipv4_is_multicast(daddr)) {
struct in_device *in_dev = __in_dev_get_rcu(dev);
+ int our = 0;
- if (in_dev) {
- int our = ip_check_mc_rcu(in_dev, daddr, saddr,
- ip_hdr(skb)->protocol);
- if (our
+ if (in_dev)
+ our = ip_check_mc_rcu(in_dev, daddr, saddr,
+ ip_hdr(skb)->protocol);
+
+ /* check l3 master if no match yet */
+ if ((!in_dev || !our) && netif_is_l3_slave(dev)) {
+ struct in_device *l3_in_dev;
+
+ l3_in_dev = __in_dev_get_rcu(skb->dev);
+ if (l3_in_dev)
+ our = ip_check_mc_rcu(l3_in_dev, daddr, saddr,
+ ip_hdr(skb)->protocol);
+ }
+
+ res = -EINVAL;
+ if (our
#ifdef CONFIG_IP_MROUTE
- ||
- (!ipv4_is_local_multicast(daddr) &&
- IN_DEV_MFORWARD(in_dev))
+ ||
+ (!ipv4_is_local_multicast(daddr) &&
+ IN_DEV_MFORWARD(in_dev))
#endif
- ) {
- int res = ip_route_input_mc(skb, daddr, saddr,
- tos, dev, our);
- rcu_read_unlock();
- return res;
- }
+ ) {
+ res = ip_route_input_mc(skb, daddr, saddr,
+ tos, dev, our);
}
rcu_read_unlock();
- return -EINVAL;
+ return res;
}
res = ip_route_input_slow(skb, daddr, saddr, tos, dev);
rcu_read_unlock();
@@ -2266,7 +2276,8 @@ struct rtable *__ip_route_output_key_hash(struct net *net, struct flowi4 *fl4,
res.fi = NULL;
res.table = NULL;
if (fl4->flowi4_oif &&
- !netif_index_is_l3_master(net, fl4->flowi4_oif)) {
+ (ipv4_is_multicast(fl4->daddr) ||
+ !netif_index_is_l3_master(net, fl4->flowi4_oif))) {
/* Apparently, routing tables are wrong. Assume,
that the destination is on link.