kernel: update and fix xt_FLOWOFFLOAD target on 4.19

Merge upstream changes to nft_flow_offload.
Fixes offloading

Signed-off-by: Felix Fietkau <nbd@nbd.name>

target/linux/generic/hack-4.19/650-netfilter-add-xt_OFFLOAD-target.patch

@@ -98,7 +98,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
  obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o
 --- /dev/null
 +++ b/net/netfilter/xt_FLOWOFFLOAD.c
-@@ -0,0 +1,371 @@
+@@ -0,0 +1,383 @@
 +/*
 + * Copyright (C) 2018 Felix Fietkau <nbd@nbd.name>
 + *
@@ -112,6 +112,8 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +#include <linux/netfilter/xt_FLOWOFFLOAD.h>
 +#include <net/ip.h>
 +#include <net/netfilter/nf_conntrack.h>
++#include <net/netfilter/nf_conntrack_extend.h>
++#include <net/netfilter/nf_conntrack_helper.h>
 +#include <net/netfilter/nf_flow_table.h>
 +
 +static struct nf_flowtable nf_flowtable;
@@ -279,21 +281,24 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +}
 +
 +static bool
-+xt_flowoffload_skip(struct sk_buff *skb)
++xt_flowoffload_skip(struct sk_buff *skb, int family)
 +{
-+	struct ip_options *opt = &(IPCB(skb)->opt);
-+
-+	if (unlikely(opt->optlen))
-+		return true;
 +	if (skb_sec_path(skb))
 +		return true;
 +
++	if (family == NFPROTO_IPV4) {
++		const struct ip_options *opt = &(IPCB(skb)->opt);
++
++		if (unlikely(opt->optlen))
++			return true;
++	}
++
 +	return false;
 +}
 +
 +static struct dst_entry *
 +xt_flowoffload_dst(const struct nf_conn *ct, enum ip_conntrack_dir dir,
-+		   const struct xt_action_param *par)
++		   const struct xt_action_param *par, int ifindex)
 +{
 +	struct dst_entry *dst = NULL;
 +	struct flowi fl;
@@ -321,8 +326,8 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +{
 +	struct dst_entry *this_dst, *other_dst;
 +
-+	this_dst = xt_flowoffload_dst(ct, dir, par);
-+	other_dst = xt_flowoffload_dst(ct, !dir, par);
++	this_dst = xt_flowoffload_dst(ct, !dir, par, xt_out(par)->ifindex);
++	other_dst = xt_flowoffload_dst(ct, dir, par, xt_in(par)->ifindex);
 +	if (!this_dst || !other_dst)
 +		return -ENOENT;
 +
@@ -345,8 +350,9 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +	struct flow_offload *flow;
 +	struct nf_conn *ct;
 +	struct net *net;
++	bool is_tcp = false;
 +
-+	if (xt_flowoffload_skip(skb))
++	if (xt_flowoffload_skip(skb, xt_family(par)))
 +		return XT_CONTINUE;
 +
 +	ct = nf_ct_get(skb, &ctinfo);
@@ -357,6 +363,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +	case IPPROTO_TCP:
 +		if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED)
 +			return XT_CONTINUE;
++		is_tcp = true;
 +		break;
 +	case IPPROTO_UDP:
 +		break;
@@ -364,11 +371,11 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +		return XT_CONTINUE;
 +	}
 +
-+	if (test_bit(IPS_HELPER_BIT, &ct->status))
++	if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
++	    ct->status & IPS_SEQ_ADJUST)
 +		return XT_CONTINUE;
 +
-+	if (ctinfo == IP_CT_NEW ||
-+	    ctinfo == IP_CT_RELATED)
++	if (!nf_ct_is_confirmed(ct))
 +		return XT_CONTINUE;
 +
 +	if (!xt_in(par) || !xt_out(par))
@@ -386,6 +393,11 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +	if (!flow)
 +		goto err_flow_alloc;
 +
++	if (is_tcp) {
++		ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
++		ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
++	}
++
 +	if (flow_offload_add(&nf_flowtable, flow) < 0)
 +		goto err_flow_add;
 +