netfilter: nft_flow_offload: fix checking method of conntrack helper

This patch uses nfct_help() to detect whether an established connection
needs conntrack helper instead of using test_bit(IPS_HELPER_BIT,
&ct->status).

The reason is that IPS_HELPER_BIT is only set when using explicit CT
target.

However, in the case that a device enables conntrack helper via command
"echo 1 > /proc/sys/net/netfilter/nf_conntrack_helper", the status of
IPS_HELPER_BIT will not present any change, and consequently it loses
the checking ability in the context.

Signed-off-by: Henry Yen <henry.yen@mediatek.com>
Reviewed-by: Ryder Lee <ryder.lee@mediatek.com>
Tested-by: John Crispin <john@phrozen.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/net/netfilter/nft_flow_offload.c b/net/netfilter/nft_flow_offload.c
index 188c6bbf4e16537dc75958f80a6c0199d5d933a7..6e6b9adf7d387717ff6f99a87093e41478c9889f 100644 (file)
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -12,6 +12,7 @@
 #include <net/netfilter/nf_conntrack_core.h>
 #include <linux/netfilter/nf_conntrack_common.h>
 #include <net/netfilter/nf_flow_table.h>
+#include <net/netfilter/nf_conntrack_helper.h>
 
 struct nft_flow_offload {
        struct nft_flowtable    *flowtable;
@@ -66,6 +67,7 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
 {
        struct nft_flow_offload *priv = nft_expr_priv(expr);
        struct nf_flowtable *flowtable = &priv->flowtable->data;
+       const struct nf_conn_help *help;
        enum ip_conntrack_info ctinfo;
        struct nf_flow_route route;
        struct flow_offload *flow;
@@ -88,7 +90,8 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
                goto out;
        }
 
-       if (test_bit(IPS_HELPER_BIT, &ct->status))
+       help = nfct_help(ct);
+       if (help)
                goto out;
 
        if (ctinfo == IP_CT_NEW ||