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Commit 91820da6 authored by Jiri Benc's avatar Jiri Benc Committed by David S. Miller
Browse files

openvswitch: add Ethernet push and pop actions 



It's not allowed to push Ethernet header in front of another Ethernet
header.

It's not allowed to pop Ethernet header if there's a vlan tag. This
preserves the invariant that L3 packet never has a vlan tag.

Based on previous versions by Lorand Jakab and Simon Horman.

Signed-off-by: default avatarLorand Jakab <lojakab@cisco.com>
Signed-off-by: default avatarSimon Horman <simon.horman@netronome.com>
Signed-off-by: default avatarJiri Benc <jbenc@redhat.com>
Acked-by: default avatarPravin B Shelar <pshelar@ovn.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0a6410fb

include/uapi/linux/openvswitch.h

+15 −0
Original line number Diff line number Diff line
@@ -705,6 +705,15 @@ enum ovs_nat_attr { 


#define OVS_NAT_ATTR_MAX (__OVS_NAT_ATTR_MAX - 1)



/*

 * struct ovs_action_push_eth - %OVS_ACTION_ATTR_PUSH_ETH action argument.

 * @addresses: Source and destination MAC addresses.

 * @eth_type: Ethernet type

 */

struct ovs_action_push_eth {

	struct ovs_key_ethernet addresses;

};



/**

 * enum ovs_action_attr - Action types.

 *
@@ -738,6 +747,10 @@ enum ovs_nat_attr { 
 * is no MPLS label stack, as determined by ethertype, no action is taken.

 * @OVS_ACTION_ATTR_CT: Track the connection. Populate the conntrack-related

 * entries in the flow key.

 * @OVS_ACTION_ATTR_PUSH_ETH: Push a new outermost Ethernet header onto the

 * packet.

 * @OVS_ACTION_ATTR_POP_ETH: Pop the outermost Ethernet header off the

 * packet.

 *

 * Only a single header can be set with a single %OVS_ACTION_ATTR_SET.  Not all

 * fields within a header are modifiable, e.g. the IPv4 protocol and fragment
@@ -765,6 +778,8 @@ enum ovs_action_attr { 
				       * bits. */

	OVS_ACTION_ATTR_CT,           /* Nested OVS_CT_ATTR_* . */

	OVS_ACTION_ATTR_TRUNC,        /* u32 struct ovs_action_trunc. */

	OVS_ACTION_ATTR_PUSH_ETH,     /* struct ovs_action_push_eth. */

	OVS_ACTION_ATTR_POP_ETH,      /* No argument. */



	__OVS_ACTION_ATTR_MAX,	      /* Nothing past this will be accepted

				       * from userspace. */

net/openvswitch/actions.c

+49 −0
Original line number Diff line number Diff line
@@ -317,6 +317,47 @@ static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *flow_key, 
	return 0;

}



/* pop_eth does not support VLAN packets as this action is never called

 * for them.

 */

static int pop_eth(struct sk_buff *skb, struct sw_flow_key *key)

{

	skb_pull_rcsum(skb, ETH_HLEN);

	skb_reset_mac_header(skb);

	skb_reset_mac_len(skb);



	/* safe right before invalidate_flow_key */

	key->mac_proto = MAC_PROTO_NONE;

	invalidate_flow_key(key);

	return 0;

}



static int push_eth(struct sk_buff *skb, struct sw_flow_key *key,

		    const struct ovs_action_push_eth *ethh)

{

	struct ethhdr *hdr;



	/* Add the new Ethernet header */

	if (skb_cow_head(skb, ETH_HLEN) < 0)

		return -ENOMEM;



	skb_push(skb, ETH_HLEN);

	skb_reset_mac_header(skb);

	skb_reset_mac_len(skb);



	hdr = eth_hdr(skb);

	ether_addr_copy(hdr->h_source, ethh->addresses.eth_src);

	ether_addr_copy(hdr->h_dest, ethh->addresses.eth_dst);

	hdr->h_proto = skb->protocol;



	skb_postpush_rcsum(skb, hdr, ETH_HLEN);



	/* safe right before invalidate_flow_key */

	key->mac_proto = MAC_PROTO_ETHERNET;

	invalidate_flow_key(key);

	return 0;

}



static void update_ip_l4_checksum(struct sk_buff *skb, struct iphdr *nh,

				  __be32 addr, __be32 new_addr)

{
@@ -1200,6 +1241,14 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, 
			if (err)

				return err == -EINPROGRESS ? 0 : err;

			break;



		case OVS_ACTION_ATTR_PUSH_ETH:

			err = push_eth(skb, key, nla_data(a));

			break;



		case OVS_ACTION_ATTR_POP_ETH:

			err = pop_eth(skb, key);

			break;

		}



		if (unlikely(err)) {

net/openvswitch/flow_netlink.c

+18 −0
Original line number Diff line number Diff line
@@ -2383,6 +2383,8 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr, 
			[OVS_ACTION_ATTR_HASH] = sizeof(struct ovs_action_hash),

			[OVS_ACTION_ATTR_CT] = (u32)-1,

			[OVS_ACTION_ATTR_TRUNC] = sizeof(struct ovs_action_trunc),

			[OVS_ACTION_ATTR_PUSH_ETH] = sizeof(struct ovs_action_push_eth),

			[OVS_ACTION_ATTR_POP_ETH] = 0,

		};

		const struct ovs_action_push_vlan *vlan;

		int type = nla_type(a);
@@ -2517,6 +2519,22 @@ static int __ovs_nla_copy_actions(struct net *net, const struct nlattr *attr, 
			skip_copy = true;

			break;



		case OVS_ACTION_ATTR_PUSH_ETH:

			/* Disallow pushing an Ethernet header if one

			 * is already present */

			if (mac_proto != MAC_PROTO_NONE)

				return -EINVAL;

			mac_proto = MAC_PROTO_NONE;

			break;



		case OVS_ACTION_ATTR_POP_ETH:

			if (mac_proto != MAC_PROTO_ETHERNET)

				return -EINVAL;

			if (vlan_tci & htons(VLAN_TAG_PRESENT))

				return -EINVAL;

			mac_proto = MAC_PROTO_ETHERNET;

			break;



		default:

			OVS_NLERR(log, "Unknown Action type %d", type);

			return -EINVAL;