Add support for locally originated traffic to VRF-local addresses.
This patch handles IPv6 support. With this patch, ping, tcp and udp
packets to a local IPv6 address are successfully routed:
$ ping6 -c1 -I red 2100:1::1
ping6: Warning: source address might be selected on device other than red.
PING 2100:1::1(2100:1::1) from 2100:1::1 red: 56 data bytes
64 bytes from 2100:1::1: icmp_seq=1 ttl=64 time=0.098 ms
ip6_input is exported so the VRF driver can use it for the dst input
function. IPv4 defaults to setting the input and output functions; IPv6
does not. VRF does not need to reinvent the Rx path so just export the
function.
Signed-off-by: David Ahern <d...@cumulusnetworks.com>
---
drivers/net/vrf.c | 79 ++++++++++++++++++++++++++++++++++++++++++++--------
net/ipv6/ip6_input.c | 1 +
2 files changed, 69 insertions(+), 11 deletions(-)
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index b6e8b1e9b4fd..7a533607a08c 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -46,6 +46,7 @@ struct net_vrf {
struct rtable *rth;
struct rtable *rth_local;
struct rt6_info *rt6;
+ struct rt6_info *rt6_local;
u32 tb_id;
};
@@ -148,14 +149,39 @@ static netdev_tx_t vrf_process_v6_outbound(struct sk_buff
*skb,
struct dst_entry *dst;
struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
- /* strip the ethernet header added for pass through VRF device */
- __skb_pull(skb, skb_network_offset(skb));
-
dst = ip6_route_output(net, NULL, &fl6);
if (dst == dst_null)
goto err;
skb_dst_drop(skb);
+
+ /* if dst.dev is loopback or the VRF device again this is locally
+ * originated traffic destined to a local address. Short circuit
+ * to Rx path using our local dst
+ */
+ if (dst->dev == net->loopback_dev || dst->dev == dev) {
+ struct net_vrf *vrf = netdev_priv(dev);
+ struct rt6_info *rt6_local = vrf->rt6_local;
+
+ /* release looked up dst and use cached local dst */
+ dst_release(dst);
+
+ /* Ordering issue: cached local dst is created on newlink
+ * before the IPv6 initialization. Using the local dst
+ * requires rt6i_idev to be set so make sure it is.
+ */
+ if (!rt6_local->rt6i_idev) {
+ rt6_local->rt6i_idev = in6_dev_get(dev);
+ if (!rt6_local->rt6i_idev)
+ goto err;
+ }
+
+ return vrf_local_xmit(skb, &rt6_local->dst);
+ }
+
+ /* strip the ethernet header added for pass through VRF device */
+ __skb_pull(skb, skb_network_offset(skb));
+
skb_dst_set(skb, dst);
ret = ip6_local_out(net, skb->sk, skb);
@@ -314,30 +340,61 @@ static int vrf_output6(struct net *net, struct sock *sk,
struct sk_buff *skb)
static void vrf_rt6_release(struct net_vrf *vrf)
{
- dst_release(&vrf->rt6->dst);
+ struct rt6_info *rt6;
+
+ rt6 = vrf->rt6;
+ dst_release(&rt6->dst);
vrf->rt6 = NULL;
+
+ rt6 = vrf->rt6_local;
+ if (rt6->rt6i_idev)
+ in6_dev_put(rt6->rt6i_idev);
+
+ dst_release(&rt6->dst);
+ vrf->rt6_local = NULL;
}
static int vrf_rt6_create(struct net_device *dev)
{
+ int flags = DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE;
struct net_vrf *vrf = netdev_priv(dev);
struct net *net = dev_net(dev);
+ struct fib6_table *rt6i_table;
struct rt6_info *rt6;
int rc = -ENOMEM;
- rt6 = ip6_dst_alloc(net, dev,
- DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE);
+ rt6i_table = fib6_new_table(net, vrf->tb_id);
+ if (!rt6i_table)
+ goto out;
+
+ /* create a dst for routing packets out a VRF device */
+ rt6 = ip6_dst_alloc(net, dev, flags);
if (!rt6)
goto out;
dst_hold(&rt6->dst);
+ rt6->rt6i_table = rt6i_table;
+ rt6->dst.output = vrf_output6;
+ vrf->rt6 = rt6;
- rt6->rt6i_table = fib6_new_table(net, vrf->tb_id);
- if (!rt6->rt6i_table)
+ /* create a dst for local routing - packets sent locally
+ * to local address via the VRF device as a loopback
+ */
+ rt6 = ip6_dst_alloc(net, dev, flags);
+ if (!rt6) {
+ dst_release(&vrf->rt6->dst);
goto out;
+ }
+
+ dst_hold(&rt6->dst);
+
+ rt6->dst.flags |= DST_HOST;
+ rt6->rt6i_idev = in6_dev_get(dev);
+ rt6->rt6i_flags = RTF_UP | RTF_NONEXTHOP | RTF_LOCAL;
+ rt6->rt6i_table = rt6i_table;
+ rt6->dst.input = ip6_input;
+ vrf->rt6_local = rt6;
- rt6->dst.output = vrf_output6;
- vrf->rt6 = rt6;
rc = 0;
out:
return rc;
@@ -733,7 +790,7 @@ static struct dst_entry *vrf_get_rt6_dst(const struct
net_device *dev,
dst_hold(&rt->dst);
}
- return (struct dst_entry *)rt;
+ return &rt->dst;
}
#endif
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index f185cbcda114..d896a08be0fc 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -298,6 +298,7 @@ int ip6_input(struct sk_buff *skb)
dev_net(skb->dev), NULL, skb, skb->dev, NULL,
ip6_input_finish);
}
+EXPORT_SYMBOL_GPL(ip6_input);
int ip6_mc_input(struct sk_buff *skb)
{
--
2.1.4
