netfilter: nft_flow_offload: don't offload when sequence numbers need adjustment

We can't deal with tcp sequence number rewrite in flow_offload.
While at it, simplify helper check, we only need to know if the extension
is present, we don't need the helper data.

Signed-off-by: Florian Westphal <fw@strlen.de>
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 bde63d9c3c4e4e39e9d82eee9fc8918d49ca1ec6..c97c03c3939a99dda06f9eb633fd309411023fd8 100644 (file)
--- a/net/netfilter/nft_flow_offload.c
+++ b/net/netfilter/nft_flow_offload.c
@@ -12,7 +12,6 @@
 #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;
@@ -67,7 +66,6 @@ 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;
@@ -93,8 +91,8 @@ static void nft_flow_offload_eval(const struct nft_expr *expr,
                goto out;
        }
 
-       help = nfct_help(ct);
-       if (help)
+       if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
+           ct->status & IPS_SEQ_ADJUST)
                goto out;
 
        if (!nf_ct_is_confirmed(ct))