This adds a ct_clear action for clearing conntrack state. ct_clear is
currently implemented in OVS userspace, but is not backed by an action
in the kernel datapath. This is useful for flows that may modify a
packet tuple after a ct lookup has already occurred.
Signed-off-by: Eric Garver <e...@erig.me>
---
v2:
- Use IP_CT_UNTRACKED for nf_ct_set()
- Only fill key if previously conntracked
include/uapi/linux/openvswitch.h | 2 ++
net/openvswitch/actions.c | 4 ++++
net/openvswitch/conntrack.c | 11 +++++++++++
net/openvswitch/conntrack.h | 7 +++++++
net/openvswitch/flow_netlink.c | 5 +++++
5 files changed, 29 insertions(+)
diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index efdbfbfd3ee2..0cd6f8833147 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -807,6 +807,7 @@ struct ovs_action_push_eth {
* packet.
* @OVS_ACTION_ATTR_POP_ETH: Pop the outermost Ethernet header off the
* packet.
+ * @OVS_ACTION_ATTR_CT_CLEAR: Clear conntrack state from 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
@@ -836,6 +837,7 @@ enum ovs_action_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_CT_CLEAR, /* 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 a54a556fcdb5..a551232daf61 100644
--- a/net/openvswitch/actions.c
+++ b/net/openvswitch/actions.c
@@ -1203,6 +1203,10 @@ static int do_execute_actions(struct datapath *dp,
struct sk_buff *skb,
return err == -EINPROGRESS ? 0 : err;
break;
+ case OVS_ACTION_ATTR_CT_CLEAR:
+ err = ovs_ct_clear(skb, key);
+ break;
+
case OVS_ACTION_ATTR_PUSH_ETH:
err = push_eth(skb, key, nla_data(a));
break;
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index d558e882ca0c..fe861e2f0deb 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -1129,6 +1129,17 @@ int ovs_ct_execute(struct net *net, struct sk_buff *skb,
return err;
}
+int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
+{
+ if (skb_nfct(skb)) {
+ nf_conntrack_put(skb_nfct(skb));
+ nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
+ ovs_ct_fill_key(skb, key);
+ }
+
+ return 0;
+}
+
static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
const struct sw_flow_key *key, bool log)
{
diff --git a/net/openvswitch/conntrack.h b/net/openvswitch/conntrack.h
index bc7efd1867ab..399dfdd2c4f9 100644
--- a/net/openvswitch/conntrack.h
+++ b/net/openvswitch/conntrack.h
@@ -30,6 +30,7 @@ int ovs_ct_action_to_attr(const struct ovs_conntrack_info *,
struct sk_buff *);
int ovs_ct_execute(struct net *, struct sk_buff *, struct sw_flow_key *,
const struct ovs_conntrack_info *);
+int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key);
void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key);
int ovs_ct_put_key(const struct sw_flow_key *swkey,
@@ -73,6 +74,12 @@ static inline int ovs_ct_execute(struct net *net, struct
sk_buff *skb,
return -ENOTSUPP;
}
+static inline int ovs_ct_clear(struct sk_buff *skb,
+ struct sw_flow_key *key)
+{
+ return -ENOTSUPP;
+}
+
static inline void ovs_ct_fill_key(const struct sk_buff *skb,
struct sw_flow_key *key)
{
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index fc0ca9a89b8e..dc0d79092e74 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -76,6 +76,7 @@ static bool actions_may_change_flow(const struct nlattr
*actions)
break;
case OVS_ACTION_ATTR_CT:
+ case OVS_ACTION_ATTR_CT_CLEAR:
case OVS_ACTION_ATTR_HASH:
case OVS_ACTION_ATTR_POP_ETH:
case OVS_ACTION_ATTR_POP_MPLS:
@@ -2528,6 +2529,7 @@ static int __ovs_nla_copy_actions(struct net *net, const
struct nlattr *attr,
[OVS_ACTION_ATTR_SAMPLE] = (u32)-1,
[OVS_ACTION_ATTR_HASH] = sizeof(struct ovs_action_hash),
[OVS_ACTION_ATTR_CT] = (u32)-1,
+ [OVS_ACTION_ATTR_CT_CLEAR] = 0,
[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,
@@ -2669,6 +2671,9 @@ static int __ovs_nla_copy_actions(struct net *net, const
struct nlattr *attr,
skip_copy = true;
break;
+ case OVS_ACTION_ATTR_CT_CLEAR:
+ break;
+
case OVS_ACTION_ATTR_PUSH_ETH:
/* Disallow pushing an Ethernet header if one
* is already present */
--
2.12.0
