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: Lorand Jakab <loja...@cisco.com>
Signed-off-by: Simon Horman <simon.hor...@netronome.com>
Signed-off-by: Jiri Benc <jb...@redhat.com>
---
include/uapi/linux/openvswitch.h | 15 ++++++++++++
net/openvswitch/actions.c | 49 ++++++++++++++++++++++++++++++++++++++++
net/openvswitch/flow_netlink.c | 18 +++++++++++++++
3 files changed, 82 insertions(+)
diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index 59ed3992c760..375d812fea36 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -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. */
diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c
index 064cbcb7b0c5..a63572fb878e 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -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->mac_len -= ETH_HLEN;
+
+ /* 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->mac_len = ETH_HLEN;
+
+ 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)) {
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index c3d0cc4321c3..d19044f2b1f4 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -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;
--
1.8.3.1
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