This makes the code easier to understand and the following patches
more focused.
Signed-off-by: Jarno Rajahalme <jarno@xxxxxxx>
---
net/openvswitch/conntrack.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 3045290..2c2bf07 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -152,8 +152,12 @@ static void ovs_ct_update_key(const struct sk_buff *skb,
ct = nf_ct_get(skb, &ctinfo);
if (ct) {
state = ovs_ct_get_state(ctinfo);
+ /* All unconfirmed entries are NEW connections. */
if (!nf_ct_is_confirmed(ct))
state |= OVS_CS_F_NEW;
+ /* OVS persists the related flag for the duration of the
+ * connection.
+ */
if (ct->master)
state |= OVS_CS_F_RELATED;
zone = nf_ct_zone(ct);
@@ -165,6 +169,9 @@ static void ovs_ct_update_key(const struct sk_buff *skb,
__ovs_ct_update_key(key, state, zone, ct);
}
+/* This is called to initialize CT key fields possibly coming in from the local
+ * stack.
+ */
void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
{
ovs_ct_update_key(skb, NULL, key, false);
@@ -199,7 +206,6 @@ static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
struct nf_conn *ct;
u32 new_mark;
-
/* The connection could be invalid, in which case set_mark is no-op. */
ct = nf_ct_get(skb, &ctinfo);
if (!ct)
@@ -375,6 +381,11 @@ static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
return true;
}
+/* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
+ * not done already. Update key with new CT state.
+ * Note that if the packet is deemed invalid by conntrack, skb->nfct will be
+ * set to NULL and 0 will be returned.
+ */
static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
const struct ovs_conntrack_info *info,
struct sk_buff *skb)
@@ -418,6 +429,13 @@ static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
{
struct nf_conntrack_expect *exp;
+ /* If we pass an expected packet through nf_conntrack_in() the
+ * expectation is typically removed, but the packet could still be
+ * lost in upcall processing. To prevent this from happening we
+ * perform an explicit expectation lookup. Expected connections are
+ * always new, and will be passed through conntrack only when they are
+ * committed, as it is OK to remove the expectation at that time.
+ */
exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
if (exp) {
u8 state;
@@ -455,6 +473,7 @@ static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
err = __ovs_ct_lookup(net, key, info, skb);
if (err)
return err;
+ /* This is a no-op if the connection has already been confirmed. */
if (nf_conntrack_confirm(skb) != NF_ACCEPT)
return -EINVAL;
--
2.1.4
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