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/drivers/net/vrf.c b/drivers/net/vrf.c
index 820de6a..3bca246 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -272,11 +272,6 @@ static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
if (IS_ERR(rt))
goto err;
- if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) {
- ip_rt_put(rt);
- goto err;
- }
-
skb_dst_drop(skb);
/* if dst.dev is loopback or the VRF device again this is locally
@@ -611,6 +606,10 @@ static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
struct dst_entry *dst = NULL;
struct rtable *rth;
+ /* don't divert multicast */
+ if (ipv4_is_multicast(ip_hdr(skb)->daddr))
+ return skb;
+
rcu_read_lock();
rth = rcu_dereference(vrf->rth);
@@ -999,6 +998,9 @@ static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
skb->skb_iif = vrf_dev->ifindex;
IPCB(skb)->flags |= IPSKB_L3SLAVE;
+ if (ipv4_is_multicast(ip_hdr(skb)->daddr))
+ goto out;
+
/* loopback traffic; do not push through packet taps again.
* Reset pkt_type for upper layers to process skb
*/
@@ -1162,8 +1164,19 @@ static int vrf_add_fib_rules(const struct net_device *dev)
if (err < 0)
goto ipv6_err;
+#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
+ err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
+ if (err < 0)
+ goto ipmr_err;
+#endif
+
return 0;
+#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
+ipmr_err:
+ vrf_fib_rule(dev, AF_INET6, false);
+#endif
+
ipv6_err:
vrf_fib_rule(dev, AF_INET, false);
