Commit 007feb87 authored by Tariq Toukan's avatar Tariq Toukan Committed by Jakub Kicinski
Browse files

net/bonding: Implement ndo_sk_get_lower_dev 



Add ndo_sk_get_lower_dev() implementation for bond interfaces.

Support only for the cases where the socket's and SKBs' hash
yields identical value for the whole connection lifetime.

Here we restrict it to L3+4 sockets only, with
xmit_hash_policy==LAYER34 and bond modes xor/802.3ad.

Signed-off-by: default avatarTariq Toukan <tariqt@nvidia.com>
Reviewed-by: default avatarBoris Pismenny <borisp@nvidia.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5b998545

drivers/net/bonding/bond_main.c

+93 −0
Original line number Diff line number Diff line
@@ -301,6 +301,19 @@ netdev_tx_t bond_dev_queue_xmit(struct bonding *bond, struct sk_buff *skb, 
	return dev_queue_xmit(skb);

}



bool bond_sk_check(struct bonding *bond)

{

	switch (BOND_MODE(bond)) {

	case BOND_MODE_8023AD:

	case BOND_MODE_XOR:

		if (bond->params.xmit_policy == BOND_XMIT_POLICY_LAYER34)

			return true;

		fallthrough;

	default:

		return false;

	}

}



/*---------------------------------- VLAN -----------------------------------*/



/* In the following 2 functions, bond_vlan_rx_add_vid and bond_vlan_rx_kill_vid,
@@ -4555,6 +4568,85 @@ static struct net_device *bond_xmit_get_slave(struct net_device *master_dev, 
	return NULL;

}



static void bond_sk_to_flow(struct sock *sk, struct flow_keys *flow)

{

	switch (sk->sk_family) {

#if IS_ENABLED(CONFIG_IPV6)

	case AF_INET6:

		if (sk->sk_ipv6only ||

		    ipv6_addr_type(&sk->sk_v6_daddr) != IPV6_ADDR_MAPPED) {

			flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;

			flow->addrs.v6addrs.src = inet6_sk(sk)->saddr;

			flow->addrs.v6addrs.dst = sk->sk_v6_daddr;

			break;

		}

		fallthrough;

#endif

	default: /* AF_INET */

		flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;

		flow->addrs.v4addrs.src = inet_sk(sk)->inet_rcv_saddr;

		flow->addrs.v4addrs.dst = inet_sk(sk)->inet_daddr;

		break;

	}



	flow->ports.src = inet_sk(sk)->inet_sport;

	flow->ports.dst = inet_sk(sk)->inet_dport;

}



/**

 * bond_sk_hash_l34 - generate a hash value based on the socket's L3 and L4 fields

 * @sk: socket to use for headers

 *

 * This function will extract the necessary field from the socket and use

 * them to generate a hash based on the LAYER34 xmit_policy.

 * Assumes that sk is a TCP or UDP socket.

 */

static u32 bond_sk_hash_l34(struct sock *sk)

{

	struct flow_keys flow;

	u32 hash;



	bond_sk_to_flow(sk, &flow);



	/* L4 */

	memcpy(&hash, &flow.ports.ports, sizeof(hash));

	/* L3 */

	return bond_ip_hash(hash, &flow);

}



static struct net_device *__bond_sk_get_lower_dev(struct bonding *bond,

						  struct sock *sk)

{

	struct bond_up_slave *slaves;

	struct slave *slave;

	unsigned int count;

	u32 hash;



	slaves = rcu_dereference(bond->usable_slaves);

	count = slaves ? READ_ONCE(slaves->count) : 0;

	if (unlikely(!count))

		return NULL;



	hash = bond_sk_hash_l34(sk);

	slave = slaves->arr[hash % count];



	return slave->dev;

}



static struct net_device *bond_sk_get_lower_dev(struct net_device *dev,

						struct sock *sk)

{

	struct bonding *bond = netdev_priv(dev);

	struct net_device *lower = NULL;



	rcu_read_lock();

	if (bond_sk_check(bond))

		lower = __bond_sk_get_lower_dev(bond, sk);

	rcu_read_unlock();



	return lower;

}



static netdev_tx_t __bond_start_xmit(struct sk_buff *skb, struct net_device *dev)

{

	struct bonding *bond = netdev_priv(dev);
@@ -4691,6 +4783,7 @@ static const struct net_device_ops bond_netdev_ops = { 
	.ndo_fix_features	= bond_fix_features,

	.ndo_features_check	= passthru_features_check,

	.ndo_get_xmit_slave	= bond_xmit_get_slave,

	.ndo_sk_get_lower_dev	= bond_sk_get_lower_dev,

};



static const struct device_type bond_type = {

include/net/bonding.h

+2 −0
Original line number Diff line number Diff line
@@ -265,6 +265,8 @@ struct bond_vlan_tag { 
	unsigned short	vlan_id;

};



bool bond_sk_check(struct bonding *bond);



/**

 * Returns NULL if the net_device does not belong to any of the bond's slaves

 *