--- a/net/ipv4/netfilter/Kconfig
+++ b/net/ipv4/netfilter/Kconfig
-@@ -75,8 +75,6 @@ config NF_TABLES_ARP
+@@ -76,8 +76,6 @@ config NF_TABLES_ARP
help
This option enables the ARP support for nf_tables.
config NF_FLOW_TABLE_IPV4
tristate "Netfilter flow table IPv4 module"
depends on NF_FLOW_TABLE
-@@ -85,6 +83,8 @@ config NF_FLOW_TABLE_IPV4
+@@ -86,6 +84,8 @@ config NF_FLOW_TABLE_IPV4
To compile it as a module, choose M here.
depends on !NF_CONNTRACK || NF_CONNTRACK
--- a/net/ipv6/netfilter/Kconfig
+++ b/net/ipv6/netfilter/Kconfig
-@@ -69,7 +69,6 @@ config NFT_FIB_IPV6
+@@ -97,7 +97,6 @@ config NFT_FIB_IPV6
multicast or blackhole.
endif # NF_TABLES_IPV6
config NF_FLOW_TABLE_IPV6
tristate "Netfilter flow table IPv6 module"
-@@ -79,6 +78,8 @@ config NF_FLOW_TABLE_IPV6
+@@ -107,6 +106,8 @@ config NF_FLOW_TABLE_IPV6
To compile it as a module, choose M here.
depends on !NF_CONNTRACK || NF_CONNTRACK
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
-@@ -665,8 +665,6 @@ config NFT_FIB_NETDEV
+@@ -671,8 +671,6 @@ config NFT_FIB_NETDEV
endif # NF_TABLES_NETDEV
config NF_FLOW_TABLE_INET
tristate "Netfilter flow table mixed IPv4/IPv6 module"
depends on NF_FLOW_TABLE
-@@ -675,11 +673,12 @@ config NF_FLOW_TABLE_INET
+@@ -681,11 +679,12 @@ config NF_FLOW_TABLE_INET
To compile it as a module, choose M here.
help
This option adds the flow table core infrastructure.
-@@ -959,6 +958,15 @@ config NETFILTER_XT_TARGET_NOTRACK
+@@ -974,6 +973,15 @@ config NETFILTER_XT_TARGET_NOTRACK
depends on NETFILTER_ADVANCED
select NETFILTER_XT_TARGET_CT
depends on NETFILTER_ADVANCED
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
-@@ -133,6 +133,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_CLASSIF
+@@ -134,6 +134,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_CLASSIF
obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o
obj-$(CONFIG_NETFILTER_XT_TARGET_CT) += xt_CT.o
obj-$(CONFIG_NETFILTER_XT_TARGET_DSCP) += xt_DSCP.o
obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o
--- /dev/null
+++ b/net/netfilter/xt_FLOWOFFLOAD.c
-@@ -0,0 +1,351 @@
+@@ -0,0 +1,422 @@
+/*
+ * Copyright (C) 2018 Felix Fietkau <nbd@nbd.name>
+ *
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/netfilter.h>
++#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;
+}
+
+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;
++ struct dst_entry *dst = NULL;
+ struct flowi fl;
+
+ memset(&fl, 0, sizeof(fl));
+ switch (xt_family(par)) {
+ case NFPROTO_IPV4:
+ fl.u.ip4.daddr = ct->tuplehash[dir].tuple.src.u3.ip;
++ fl.u.ip4.flowi4_oif = ifindex;
+ break;
+ case NFPROTO_IPV6:
++ fl.u.ip6.saddr = ct->tuplehash[dir].tuple.dst.u3.in6;
+ fl.u.ip6.daddr = ct->tuplehash[dir].tuple.src.u3.in6;
++ fl.u.ip6.flowi6_oif = ifindex;
+ break;
+ }
+
+{
+ struct dst_entry *this_dst, *other_dst;
+
-+ this_dst = xt_flowoffload_dst(ct, dir, par);
-+ other_dst = xt_flowoffload_dst(ct, !dir, par);
-+ if (!this_dst || !other_dst)
-+ return -ENOENT;
++ this_dst = xt_flowoffload_dst(ct, !dir, par, xt_out(par)->ifindex);
++ other_dst = xt_flowoffload_dst(ct, dir, par, xt_in(par)->ifindex);
+
+ route->tuple[dir].dst = this_dst;
-+ route->tuple[dir].ifindex = xt_in(par)->ifindex;
+ route->tuple[!dir].dst = other_dst;
-+ route->tuple[!dir].ifindex = xt_out(par)->ifindex;
++
++ if (!this_dst || !other_dst)
++ return -ENOENT;
++
++ if (dst_xfrm(this_dst) || dst_xfrm(other_dst))
++ return -EINVAL;
+
+ return 0;
+}
+static unsigned int
+flowoffload_tg(struct sk_buff *skb, const struct xt_action_param *par)
+{
++ const struct xt_flowoffload_target_info *info = par->targinfo;
++ struct tcphdr _tcph, *tcph = NULL;
+ enum ip_conntrack_info ctinfo;
+ enum ip_conntrack_dir dir;
+ struct nf_flow_route route;
-+ struct flow_offload *flow;
++ struct flow_offload *flow = NULL;
+ struct nf_conn *ct;
++ struct net *net;
+
-+ if (xt_flowoffload_skip(skb))
++ if (xt_flowoffload_skip(skb, xt_family(par)))
+ return XT_CONTINUE;
+
+ ct = nf_ct_get(skb, &ctinfo);
+ case IPPROTO_TCP:
+ if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED)
+ return XT_CONTINUE;
++
++ tcph = skb_header_pointer(skb, par->thoff,
++ sizeof(_tcph), &_tcph);
++ if (unlikely(!tcph || tcph->fin || tcph->rst))
++ return XT_CONTINUE;
+ break;
+ case IPPROTO_UDP:
+ break;
+ 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))
+
+ dir = CTINFO2DIR(ctinfo);
+
-+ if (xt_flowoffload_route(skb, ct, par, &route, dir) < 0)
-+ goto err_flow_route;
++ if (xt_flowoffload_route(skb, ct, par, &route, dir) == 0)
++ flow = flow_offload_alloc(ct, &route);
++
++ dst_release(route.tuple[dir].dst);
++ dst_release(route.tuple[!dir].dst);
+
-+ flow = flow_offload_alloc(ct, &route);
+ if (!flow)
-+ goto err_flow_alloc;
++ goto err_flow_route;
++
++ if (tcph) {
++ 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;
+ xt_flowoffload_check_device(xt_in(par));
+ xt_flowoffload_check_device(xt_out(par));
+
++ net = read_pnet(&nf_flowtable.ft_net);
++ if (!net)
++ write_pnet(&nf_flowtable.ft_net, xt_net(par));
++
++ if (info->flags & XT_FLOWOFFLOAD_HW)
++ nf_flow_offload_hw_add(xt_net(par), flow, ct);
++
+ return XT_CONTINUE;
+
+err_flow_add:
+ flow_offload_free(flow);
-+err_flow_alloc:
-+ dst_release(route.tuple[!dir].dst);
+err_flow_route:
+ clear_bit(IPS_OFFLOAD_BIT, &ct->status);
+ return XT_CONTINUE;
+
+static int flowoffload_chk(const struct xt_tgchk_param *par)
+{
++ struct xt_flowoffload_target_info *info = par->targinfo;
++
++ if (info->flags & ~XT_FLOWOFFLOAD_MASK)
++ return -EINVAL;
++
+ return 0;
+}
+
+ .family = NFPROTO_UNSPEC,
+ .name = "FLOWOFFLOAD",
+ .revision = 0,
++ .targetsize = sizeof(struct xt_flowoffload_target_info),
++ .usersize = sizeof(struct xt_flowoffload_target_info),
+ .checkentry = flowoffload_chk,
+ .target = flowoffload_tg,
+ .me = THIS_MODULE,
+
+static int xt_flowoffload_table_init(struct nf_flowtable *table)
+{
++ table->flags = NF_FLOWTABLE_F_HW;
+ nf_flow_table_init(table);
+ return 0;
+}
+ nf_flow_table_free(table);
+}
+
++static int flow_offload_netdev_event(struct notifier_block *this,
++ unsigned long event, void *ptr)
++{
++ struct xt_flowoffload_hook *hook = NULL;
++ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
++
++ if (event != NETDEV_UNREGISTER)
++ return NOTIFY_DONE;
++
++ spin_lock_bh(&hooks_lock);
++ hook = flow_offload_lookup_hook(dev);
++ if (hook) {
++ hlist_del(&hook->list);
++ }
++ spin_unlock_bh(&hooks_lock);
++ if (hook) {
++ nf_unregister_net_hook(hook->net, &hook->ops);
++ kfree(hook);
++ }
++
++ nf_flow_table_cleanup(dev_net(dev), dev);
++
++ return NOTIFY_DONE;
++}
++
++static struct notifier_block flow_offload_netdev_notifier = {
++ .notifier_call = flow_offload_netdev_event,
++};
++
+static int __init xt_flowoffload_tg_init(void)
+{
+ int ret;
+
++ register_netdevice_notifier(&flow_offload_netdev_notifier);
++
+ INIT_DELAYED_WORK(&hook_work, xt_flowoffload_hook_work);
+
+ ret = xt_flowoffload_table_init(&nf_flowtable);
+{
+ xt_unregister_target(&offload_tg_reg);
+ xt_flowoffload_table_cleanup(&nf_flowtable);
++ unregister_netdevice_notifier(&flow_offload_netdev_notifier);
+}
+
+MODULE_LICENSE("GPL");
#include <net/netfilter/nf_flow_table.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
+--- /dev/null
++++ b/include/uapi/linux/netfilter/xt_FLOWOFFLOAD.h
+@@ -0,0 +1,17 @@
++/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
++#ifndef _XT_FLOWOFFLOAD_H
++#define _XT_FLOWOFFLOAD_H
++
++#include <linux/types.h>
++
++enum {
++ XT_FLOWOFFLOAD_HW = 1 << 0,
++
++ XT_FLOWOFFLOAD_MASK = XT_FLOWOFFLOAD_HW
++};
++
++struct xt_flowoffload_target_info {
++ __u32 flags;
++};
++
++#endif /* _XT_FLOWOFFLOAD_H */