Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b4869aa2 authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net: vrf: ipv6 support for local traffic to local addresses 



Add support for locally originated traffic to VRF-local IPv6 addresses.
Similar to IPv4 a local dst is set on the skb and the packet is
reinserted with a call to netif_rx. With this patch, ping, tcp and udp
packets to a local IPv6 address are successfully routed:

    $ ip addr show dev eth1
    4: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000
        link/ether 02:e0:f9:1c:b9:74 brd ff:ff:ff:ff:ff:ff
        inet 10.100.1.1/24 brd 10.100.1.255 scope global eth1
           valid_lft forever preferred_lft forever
        inet6 2100:1::1/120 scope global
           valid_lft forever preferred_lft forever
        inet6 fe80::e0:f9ff:fe1c:b974/64 scope link
           valid_lft forever preferred_lft forever

    $ 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. The dst_alloc function for IPv4 defaults to setting the input and
output functions; IPv6's does not. VRF does not need to duplicate the Rx path
so just export the ipv6 input function.

Signed-off-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent afe80a49

drivers/net/vrf.c

+85 −4
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ struct net_vrf { 
	struct rtable __rcu	*rth;

	struct rtable __rcu	*rth_local;

	struct rt6_info	__rcu	*rt6;

	struct rt6_info	__rcu	*rt6_local;

	u32                     tb_id;

};
@@ -157,6 +158,46 @@ static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb, 
		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;



		/* release looked up dst and use cached local dst */

		dst_release(dst);



		rcu_read_lock();



		rt6_local = rcu_dereference(vrf->rt6_local);

		if (unlikely(!rt6_local)) {

			rcu_read_unlock();

			goto err;

		}



		/* 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 (unlikely(!rt6_local->rt6i_idev)) {

			rt6_local->rt6i_idev = in6_dev_get(dev);

			if (!rt6_local->rt6i_idev) {

				rcu_read_unlock();

				goto err;

			}

		}



		dst = &rt6_local->dst;

		dst_hold(dst);



		rcu_read_unlock();



		return vrf_local_xmit(skb, dev, &rt6_local->dst);

	}



	skb_dst_set(skb, dst);



	/* strip the ethernet header added for pass through VRF device */
@@ -336,27 +377,38 @@ static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb) 
static void vrf_rt6_release(struct net_vrf *vrf)

{

	struct rt6_info *rt6 = rtnl_dereference(vrf->rt6);

	struct rt6_info *rt6_local = rtnl_dereference(vrf->rt6_local);



	rcu_assign_pointer(vrf->rt6, NULL);

	RCU_INIT_POINTER(vrf->rt6, NULL);

	RCU_INIT_POINTER(vrf->rt6_local, NULL);

	synchronize_rcu();



	if (rt6)

		dst_release(&rt6->dst);



	if (rt6_local) {

		if (rt6_local->rt6i_idev)

			in6_dev_put(rt6_local->rt6i_idev);



		dst_release(&rt6_local->dst);

	}

}



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;

	struct rt6_info *rt6, *rt6_local;

	int rc = -ENOMEM;



	rt6i_table = fib6_new_table(net, vrf->tb_id);

	if (!rt6i_table)

		goto out;



	rt6 = ip6_dst_alloc(net, dev,

			    DST_HOST | DST_NOPOLICY | DST_NOXFRM | DST_NOCACHE);

	/* create a dst for routing packets out a VRF device */

	rt6 = ip6_dst_alloc(net, dev, flags);

	if (!rt6)

		goto out;
@@ -364,7 +416,25 @@ static int vrf_rt6_create(struct net_device *dev) 


	rt6->rt6i_table = rt6i_table;

	rt6->dst.output	= vrf_output6;



	/* create a dst for local routing - packets sent locally

	 * to local address via the VRF device as a loopback

	 */

	rt6_local = ip6_dst_alloc(net, dev, flags);

	if (!rt6_local) {

		dst_release(&rt6->dst);

		goto out;

	}



	dst_hold(&rt6_local->dst);



	rt6_local->rt6i_idev  = in6_dev_get(dev);

	rt6_local->rt6i_flags = RTF_UP | RTF_NONEXTHOP | RTF_LOCAL;

	rt6_local->rt6i_table = rt6i_table;

	rt6_local->dst.input  = ip6_input;



	rcu_assign_pointer(vrf->rt6, rt6);

	rcu_assign_pointer(vrf->rt6_local, rt6_local);



	rc = 0;

out:
@@ -710,6 +780,16 @@ static bool ipv6_ndisc_frame(const struct sk_buff *skb) 
static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,

				   struct sk_buff *skb)

{

	/* loopback traffic; do not push through packet taps again.

	 * Reset pkt_type for upper layers to process skb

	 */

	if (skb->pkt_type == PACKET_LOOPBACK) {

		skb->dev = vrf_dev;

		skb->skb_iif = vrf_dev->ifindex;

		skb->pkt_type = PACKET_HOST;

		goto out;

	}



	/* if packet is NDISC keep the ingress interface */

	if (!ipv6_ndisc_frame(skb)) {

		skb->dev = vrf_dev;
@@ -722,6 +802,7 @@ static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev, 
		IP6CB(skb)->flags |= IP6SKB_L3SLAVE;

	}



out:

	return skb;

}

net/ipv6/ip6_input.c

+1 −0
Original line number Diff line number Diff line
@@ -323,6 +323,7 @@ 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)

{