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

Commit afe80a49 authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net: vrf: ipv4 support for local traffic to local addresses 



Add support for locally originated traffic to VRF-local addresses. If
destination device for an skb is the loopback or VRF device then set
its dst to a local version of the VRF cached dst_entry and call netif_rx
to insert the packet onto the rx queue - similar to what is done for
loopback. This patch handles IPv4 support; follow on patch handles IPv6.

With this patch, ping, tcp and udp packets to a local IPv4 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

    $ ping -c1 -I red 10.100.1.1
    ping: Warning: source address might be selected on device other than red.
    PING 10.100.1.1 (10.100.1.1) from 10.100.1.1 red: 56(84) bytes of data.
    64 bytes from 10.100.1.1: icmp_seq=1 ttl=64 time=0.057 ms

This patch also enables use of IPv4 loopback address on the VRF device:
    $ ip addr add dev red 127.0.0.1/8

    $ ping -c1 -I red 127.0.0.1
    PING 127.0.0.1 (127.0.0.1) from 127.0.0.1 red: 56(84) bytes of data.
    64 bytes from 127.0.0.1: icmp_seq=1 ttl=64 time=0.058 ms

Signed-off-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 911a66fb

drivers/net/vrf.c

+98 −2
Original line number Diff line number Diff line
@@ -44,6 +44,7 @@ 


struct net_vrf {

	struct rtable __rcu	*rth;

	struct rtable __rcu	*rth_local;

	struct rt6_info	__rcu	*rt6;

	u32                     tb_id;

};
@@ -54,9 +55,20 @@ struct pcpu_dstats { 
	u64			tx_drps;

	u64			rx_pkts;

	u64			rx_bytes;

	u64			rx_drps;

	struct u64_stats_sync	syncp;

};



static void vrf_rx_stats(struct net_device *dev, int len)

{

	struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);



	u64_stats_update_begin(&dstats->syncp);

	dstats->rx_pkts++;

	dstats->rx_bytes += len;

	u64_stats_update_end(&dstats->syncp);

}



static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)

{

	vrf_dev->stats.tx_errors++;
@@ -91,6 +103,34 @@ static struct rtnl_link_stats64 *vrf_get_stats64(struct net_device *dev, 
	return stats;

}



/* Local traffic destined to local address. Reinsert the packet to rx

 * path, similar to loopback handling.

 */

static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,

			  struct dst_entry *dst)

{

	int len = skb->len;



	skb_orphan(skb);



	skb_dst_set(skb, dst);

	skb_dst_force(skb);



	/* set pkt_type to avoid skb hitting packet taps twice -

	 * once on Tx and again in Rx processing

	 */

	skb->pkt_type = PACKET_LOOPBACK;



	skb->protocol = eth_type_trans(skb, dev);



	if (likely(netif_rx(skb) == NET_RX_SUCCESS))

		vrf_rx_stats(dev, len);

	else

		this_cpu_inc(dev->dstats->rx_drps);



	return NETDEV_TX_OK;

}



#if IS_ENABLED(CONFIG_IPV6)

static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,

					   struct net_device *dev)
@@ -169,6 +209,34 @@ static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb, 
	}



	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 (rt->dst.dev == net->loopback_dev || rt->dst.dev == vrf_dev) {

		struct net_vrf *vrf = netdev_priv(vrf_dev);

		struct rtable *rth_local;

		struct dst_entry *dst = NULL;



		ip_rt_put(rt);



		rcu_read_lock();



		rth_local = rcu_dereference(vrf->rth_local);

		if (likely(rth_local)) {

			dst = &rth_local->dst;

			dst_hold(dst);

		}



		rcu_read_unlock();



		if (unlikely(!dst))

			goto err;



		return vrf_local_xmit(skb, vrf_dev, dst);

	}



	skb_dst_set(skb, &rt->dst);



	/* strip the ethernet header added for pass through VRF device */
@@ -375,29 +443,48 @@ static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb) 
static void vrf_rtable_release(struct net_vrf *vrf)

{

	struct rtable *rth = rtnl_dereference(vrf->rth);

	struct rtable *rth_local = rtnl_dereference(vrf->rth_local);



	rcu_assign_pointer(vrf->rth, NULL);

	RCU_INIT_POINTER(vrf->rth, NULL);

	RCU_INIT_POINTER(vrf->rth_local, NULL);

	synchronize_rcu();



	if (rth)

		dst_release(&rth->dst);



	if (rth_local)

		dst_release(&rth_local->dst);

}



static int vrf_rtable_create(struct net_device *dev)

{

	struct net_vrf *vrf = netdev_priv(dev);

	struct rtable *rth;

	struct rtable *rth, *rth_local;



	if (!fib_new_table(dev_net(dev), vrf->tb_id))

		return -ENOMEM;



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

	rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1, 1, 0);

	if (!rth)

		return -ENOMEM;



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

	 * to local address via the VRF device as a loopback

	 */

	rth_local = rt_dst_alloc(dev, RTCF_LOCAL, RTN_LOCAL, 1, 1, 0);

	if (!rth_local) {

		dst_release(&rth->dst);

		return -ENOMEM;

	}



	rth->dst.output	= vrf_output;

	rth->rt_table_id = vrf->tb_id;



	rth_local->rt_table_id = vrf->tb_id;



	rcu_assign_pointer(vrf->rth, rth);

	rcu_assign_pointer(vrf->rth_local, rth_local);



	return 0;

}
@@ -652,10 +739,19 @@ static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev, 
	skb->dev = vrf_dev;

	skb->skb_iif = vrf_dev->ifindex;



	/* 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->pkt_type = PACKET_HOST;

		goto out;

	}



	skb_push(skb, skb->mac_len);

	dev_queue_xmit_nit(skb, vrf_dev);

	skb_pull(skb, skb->mac_len);



out:

	return skb;

}