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>
This commit is contained in:
David Ahern 2016-10-31 15:54:00 -07:00 committed by David S. Miller
commit e58e415968
3 changed files with 56 additions and 21 deletions

View file

@ -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.