On 24/10/2023 22:38, Pablo Neira Ayuso wrote:
Since 41f2c7c342d3 ("net/sched: act_ct: Fix promotion of offloaded
unreplied tuple"), flowtable GC pushes back flows with IPS_SEEN_REPLY
back to classic path in every run, ie. every second. This is because of
a new check for NF_FLOW_HW_ESTABLISHED which is specific of sched/act_ct.
In Netfilter's flowtable case, NF_FLOW_HW_ESTABLISHED never gets set on
and IPS_SEEN_REPLY is unreliable since users decide when to offload the
flow before, such bit might be set on at a later stage.
Fix it by adding a custom .gc handler that sched/act_ct can use to
deal with its NF_FLOW_HW_ESTABLISHED bit.
Fixes: 41f2c7c342d3 ("net/sched: act_ct: Fix promotion of offloaded unreplied tuple")
Reported-by: Vladimir Smelhaus <vl.sm@xxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
include/net/netfilter/nf_flow_table.h | 1 +
net/netfilter/nf_flow_table_core.c | 14 +++++++-------
net/sched/act_ct.c | 7 +++++++
3 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h
index d466e1a3b0b1..fe1507c1db82 100644
--- a/include/net/netfilter/nf_flow_table.h
+++ b/include/net/netfilter/nf_flow_table.h
@@ -53,6 +53,7 @@ struct nf_flowtable_type {
struct list_head list;
int family;
int (*init)(struct nf_flowtable *ft);
+ bool (*gc)(const struct flow_offload *flow);
int (*setup)(struct nf_flowtable *ft,
struct net_device *dev,
enum flow_block_command cmd);
diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index 1d34d700bd09..920a5a29ae1d 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -316,12 +316,6 @@ void flow_offload_refresh(struct nf_flowtable *flow_table,
}
EXPORT_SYMBOL_GPL(flow_offload_refresh);
-static bool nf_flow_is_outdated(const struct flow_offload *flow)
-{
- return test_bit(IPS_SEEN_REPLY_BIT, &flow->ct->status) &&
- !test_bit(NF_FLOW_HW_ESTABLISHED, &flow->flags);
-}
-
static inline bool nf_flow_has_expired(const struct flow_offload *flow)
{
return nf_flow_timeout_delta(flow->timeout) <= 0;
@@ -407,12 +401,18 @@ nf_flow_table_iterate(struct nf_flowtable *flow_table,
return err;
}
+static bool nf_flow_custom_gc(struct nf_flowtable *flow_table,
+ const struct flow_offload *flow)
+{
+ return flow_table->type->gc && flow_table->type->gc(flow);
+}
+
static void nf_flow_offload_gc_step(struct nf_flowtable *flow_table,
struct flow_offload *flow, void *data)
{
if (nf_flow_has_expired(flow) ||
nf_ct_is_dying(flow->ct) ||
- nf_flow_is_outdated(flow))
+ nf_flow_custom_gc(flow_table, flow))
flow_offload_teardown(flow);
if (test_bit(NF_FLOW_TEARDOWN, &flow->flags)) {
diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index 7c652d14528b..0d44da4e8c8e 100644
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -278,7 +278,14 @@ static int tcf_ct_flow_table_fill_actions(struct net *net,
return err;
}
+static bool tcf_ct_flow_is_outdated(const struct flow_offload *flow)
+{
+ return test_bit(IPS_SEEN_REPLY_BIT, &flow->ct->status) &&
+ !test_bit(NF_FLOW_HW_ESTABLISHED, &flow->flags);
+}
+
static struct nf_flowtable_type flowtable_ct = {
+ .gc = tcf_ct_flow_is_outdated,
.action = tcf_ct_flow_table_fill_actions,
.owner = THIS_MODULE,
};
Reviewed-by: Paul Blakey <paulb@xxxxxxxxxx>
