kernel: update 5.10 flow offload patches

Includes PPPoE support and VLAN related fixes

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

1 files changed, 820 insertions, 0 deletions

diff --git a/target/linux/generic/hack-5.10/650-netfilter-add-xt_FLOWOFFLOAD-target.patch b/target/linux/generic/hack-5.10/650-netfilter-add-xt_FLOWOFFLOAD-target.patch
new file mode 100644
index 0000000000..97aa7a673b
--- /dev/null
+++ b/target/linux/generic/hack-5.10/650-netfilter-add-xt_FLOWOFFLOAD-target.patch
@@ -0,0 +1,820 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Tue, 20 Feb 2018 15:56:02 +0100
+Subject: [PATCH] netfilter: add xt_FLOWOFFLOAD target
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+ create mode 100644 net/netfilter/xt_OFFLOAD.c
+
+--- a/net/ipv4/netfilter/Kconfig
++++ b/net/ipv4/netfilter/Kconfig
+@@ -56,8 +56,6 @@ config NF_TABLES_ARP
+ 	help
+ 	  This option enables the ARP support for nf_tables.
+ 
+-endif # NF_TABLES
+-
+ config NF_FLOW_TABLE_IPV4
+ 	tristate "Netfilter flow table IPv4 module"
+ 	depends on NF_FLOW_TABLE
+@@ -66,6 +64,8 @@ config NF_FLOW_TABLE_IPV4
+ 
+ 	  To compile it as a module, choose M here.
+ 
++endif # NF_TABLES
++
+ config NF_DUP_IPV4
+ 	tristate "Netfilter IPv4 packet duplication to alternate destination"
+ 	depends on !NF_CONNTRACK || NF_CONNTRACK
+--- a/net/ipv6/netfilter/Kconfig
++++ b/net/ipv6/netfilter/Kconfig
+@@ -45,7 +45,6 @@ config NFT_FIB_IPV6
+ 	  multicast or blackhole.
+ 
+ endif # NF_TABLES_IPV6
+-endif # NF_TABLES
+ 
+ config NF_FLOW_TABLE_IPV6
+ 	tristate "Netfilter flow table IPv6 module"
+@@ -55,6 +54,8 @@ config NF_FLOW_TABLE_IPV6
+ 
+ 	  To compile it as a module, choose M here.
+ 
++endif # NF_TABLES
++
+ config NF_DUP_IPV6
+ 	tristate "Netfilter IPv6 packet duplication to alternate destination"
+ 	depends on !NF_CONNTRACK || NF_CONNTRACK
+--- a/net/netfilter/Kconfig
++++ b/net/netfilter/Kconfig
+@@ -683,8 +683,6 @@ config NFT_FIB_NETDEV
+ 
+ endif # NF_TABLES_NETDEV
+ 
+-endif # NF_TABLES
+-
+ config NF_FLOW_TABLE_INET
+ 	tristate "Netfilter flow table mixed IPv4/IPv6 module"
+ 	depends on NF_FLOW_TABLE
+@@ -693,11 +691,12 @@ config NF_FLOW_TABLE_INET
+ 
+ 	  To compile it as a module, choose M here.
+ 
++endif # NF_TABLES
++
+ config NF_FLOW_TABLE
+ 	tristate "Netfilter flow table module"
+ 	depends on NETFILTER_INGRESS
+ 	depends on NF_CONNTRACK
+-	depends on NF_TABLES
+ 	help
+ 	  This option adds the flow table core infrastructure.
+ 
+@@ -977,6 +976,15 @@ config NETFILTER_XT_TARGET_NOTRACK
+ 	depends on NETFILTER_ADVANCED
+ 	select NETFILTER_XT_TARGET_CT
+ 
++config NETFILTER_XT_TARGET_FLOWOFFLOAD
++	tristate '"FLOWOFFLOAD" target support'
++	depends on NF_FLOW_TABLE
++	depends on NETFILTER_INGRESS
++	help
++	  This option adds a `FLOWOFFLOAD' target, which uses the nf_flow_offload
++	  module to speed up processing of packets by bypassing the usual
++	  netfilter chains
++
+ config NETFILTER_XT_TARGET_RATEEST
+ 	tristate '"RATEEST" target support'
+ 	depends on NETFILTER_ADVANCED
+--- a/net/netfilter/Makefile
++++ b/net/netfilter/Makefile
+@@ -145,6 +145,7 @@ 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-$(CONFIG_NETFILTER_XT_TARGET_FLOWOFFLOAD) += xt_FLOWOFFLOAD.o
+ obj-$(CONFIG_NETFILTER_XT_TARGET_HL) += xt_HL.o
+ obj-$(CONFIG_NETFILTER_XT_TARGET_HMARK) += xt_HMARK.o
+ obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o
+--- /dev/null
++++ b/net/netfilter/xt_FLOWOFFLOAD.c
+@@ -0,0 +1,658 @@
++/*
++ * Copyright (C) 2018-2021 Felix Fietkau <nbd@nbd.name>
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ */
++#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>
++
++struct xt_flowoffload_hook {
++	struct hlist_node list;
++	struct nf_hook_ops ops;
++	struct net *net;
++	bool registered;
++	bool used;
++};
++
++struct xt_flowoffload_table {
++	struct nf_flowtable ft;
++	struct hlist_head hooks;
++	struct delayed_work work;
++};
++
++static DEFINE_SPINLOCK(hooks_lock);
++
++struct xt_flowoffload_table flowtable[2];
++
++static unsigned int
++xt_flowoffload_net_hook(void *priv, struct sk_buff *skb,
++			const struct nf_hook_state *state)
++{
++	struct nf_flowtable *ft = priv;
++
++	if (!atomic_read(&ft->rhashtable.nelems))
++		return NF_ACCEPT;
++
++	switch (skb->protocol) {
++	case htons(ETH_P_IP):
++		return nf_flow_offload_ip_hook(priv, skb, state);
++	case htons(ETH_P_IPV6):
++		return nf_flow_offload_ipv6_hook(priv, skb, state);
++	}
++
++	return NF_ACCEPT;
++}
++
++static int
++xt_flowoffload_create_hook(struct xt_flowoffload_table *table,
++			   struct net_device *dev)
++{
++	struct xt_flowoffload_hook *hook;
++	struct nf_hook_ops *ops;
++
++	hook = kzalloc(sizeof(*hook), GFP_ATOMIC);
++	if (!hook)
++		return -ENOMEM;
++
++	ops = &hook->ops;
++	ops->pf = NFPROTO_NETDEV;
++	ops->hooknum = NF_NETDEV_INGRESS;
++	ops->priority = 10;
++	ops->priv = &table->ft;
++	ops->hook = xt_flowoffload_net_hook;
++	ops->dev = dev;
++
++	hlist_add_head(&hook->list, &table->hooks);
++	mod_delayed_work(system_power_efficient_wq, &table->work, 0);
++
++	return 0;
++}
++
++static struct xt_flowoffload_hook *
++flow_offload_lookup_hook(struct xt_flowoffload_table *table,
++			 struct net_device *dev)
++{
++	struct xt_flowoffload_hook *hook;
++
++	hlist_for_each_entry(hook, &table->hooks, list) {
++		if (hook->ops.dev == dev)
++			return hook;
++	}
++
++	return NULL;
++}
++
++static void
++xt_flowoffload_check_device(struct xt_flowoffload_table *table,
++			    struct net_device *dev)
++{
++	struct xt_flowoffload_hook *hook;
++
++	if (!dev)
++		return;
++
++	spin_lock_bh(&hooks_lock);
++	hook = flow_offload_lookup_hook(table, dev);
++	if (hook)
++		hook->used = true;
++	else
++		xt_flowoffload_create_hook(table, dev);
++	spin_unlock_bh(&hooks_lock);
++}
++
++static void
++xt_flowoffload_register_hooks(struct xt_flowoffload_table *table)
++{
++	struct xt_flowoffload_hook *hook;
++
++restart:
++	hlist_for_each_entry(hook, &table->hooks, list) {
++		if (hook->registered)
++			continue;
++
++		hook->registered = true;
++		hook->net = dev_net(hook->ops.dev);
++		spin_unlock_bh(&hooks_lock);
++		nf_register_net_hook(hook->net, &hook->ops);
++		if (table->ft.flags & NF_FLOWTABLE_HW_OFFLOAD)
++			table->ft.type->setup(&table->ft, hook->ops.dev,
++					      FLOW_BLOCK_BIND);
++		spin_lock_bh(&hooks_lock);
++		goto restart;
++	}
++
++}
++
++static bool
++xt_flowoffload_cleanup_hooks(struct xt_flowoffload_table *table)
++{
++	struct xt_flowoffload_hook *hook;
++	bool active = false;
++
++restart:
++	spin_lock_bh(&hooks_lock);
++	hlist_for_each_entry(hook, &table->hooks, list) {
++		if (hook->used || !hook->registered) {
++			active = true;
++			continue;
++		}
++
++		hlist_del(&hook->list);
++		spin_unlock_bh(&hooks_lock);
++		if (table->ft.flags & NF_FLOWTABLE_HW_OFFLOAD)
++			table->ft.type->setup(&table->ft, hook->ops.dev,
++					      FLOW_BLOCK_UNBIND);
++		nf_unregister_net_hook(hook->net, &hook->ops);
++		kfree(hook);
++		goto restart;
++	}
++	spin_unlock_bh(&hooks_lock);
++
++	return active;
++}
++
++static void
++xt_flowoffload_check_hook(struct flow_offload *flow, void *data)
++{
++	struct xt_flowoffload_table *table = data;
++	struct flow_offload_tuple *tuple0 = &flow->tuplehash[0].tuple;
++	struct flow_offload_tuple *tuple1 = &flow->tuplehash[1].tuple;
++	struct xt_flowoffload_hook *hook;
++
++	spin_lock_bh(&hooks_lock);
++	hlist_for_each_entry(hook, &table->hooks, list) {
++		if (hook->ops.dev->ifindex != tuple0->iifidx &&
++		    hook->ops.dev->ifindex != tuple1->iifidx)
++			continue;
++
++		hook->used = true;
++	}
++	spin_unlock_bh(&hooks_lock);
++
++	cond_resched();
++}
++
++static void
++xt_flowoffload_hook_work(struct work_struct *work)
++{
++	struct xt_flowoffload_table *table;
++	struct xt_flowoffload_hook *hook;
++	int err;
++
++	table = container_of(work, struct xt_flowoffload_table, work.work);
++
++	spin_lock_bh(&hooks_lock);
++	xt_flowoffload_register_hooks(table);
++	hlist_for_each_entry(hook, &table->hooks, list)
++		hook->used = false;
++	spin_unlock_bh(&hooks_lock);
++
++	err = nf_flow_table_iterate(&table->ft, xt_flowoffload_check_hook,
++				    table);
++	if (err && err != -EAGAIN)
++		goto out;
++
++	if (!xt_flowoffload_cleanup_hooks(table))
++		return;
++
++out:
++	queue_delayed_work(system_power_efficient_wq, &table->work, HZ);
++}
++
++static bool
++xt_flowoffload_skip(struct sk_buff *skb, int family)
++{
++	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 bool flow_is_valid_ether_device(const struct net_device *dev)
++{
++	if (!dev || (dev->flags & IFF_LOOPBACK) || dev->type != ARPHRD_ETHER ||
++	    dev->addr_len != ETH_ALEN || !is_valid_ether_addr(dev->dev_addr))
++		return false;
++
++	return true;
++}
++
++static void
++xt_flowoffload_route_check_path(struct nf_flow_route *route,
++				const struct nf_conn *ct,
++				enum ip_conntrack_dir dir,
++				struct net_device **out_dev)
++{
++	const struct dst_entry *dst = route->tuple[dir].dst;
++	const void *daddr = &ct->tuplehash[!dir].tuple.src.u3;
++	struct net_device_path_stack stack;
++	enum net_device_path_type prev_type;
++	struct net_device *dev = dst->dev;
++	struct neighbour *n;
++	bool last = false;
++	u8 nud_state;
++	int i;
++
++	route->tuple[!dir].in.ifindex = dev->ifindex;
++	route->tuple[dir].out.ifindex = dev->ifindex;
++
++	if (route->tuple[dir].xmit_type == FLOW_OFFLOAD_XMIT_XFRM)
++		return;
++
++	if ((dev->flags & IFF_LOOPBACK) ||
++	    dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
++	    !is_valid_ether_addr(dev->dev_addr))
++		return;
++
++	n = dst_neigh_lookup(dst, daddr);
++	if (!n)
++		return;
++
++	read_lock_bh(&n->lock);
++	nud_state = n->nud_state;
++	memcpy(route->tuple[dir].out.h_dest, n->ha, ETH_ALEN);
++	read_unlock_bh(&n->lock);
++	neigh_release(n);
++
++	if (!(nud_state & NUD_VALID))
++		return;
++
++	if (dev_fill_forward_path(dev, route->tuple[dir].out.h_dest, &stack) ||
++	    !stack.num_paths)
++		return;
++
++	prev_type = DEV_PATH_ETHERNET;
++	for (i = 0; i <= stack.num_paths; i++) {
++		const struct net_device_path *path = &stack.path[i];
++		int n_encaps = route->tuple[!dir].in.num_encaps;
++
++		dev = (struct net_device *)path->dev;
++		if (flow_is_valid_ether_device(dev)) {
++			if (route->tuple[dir].xmit_type != FLOW_OFFLOAD_XMIT_DIRECT) {
++				memcpy(route->tuple[dir].out.h_source,
++				       dev->dev_addr, ETH_ALEN);
++				route->tuple[dir].out.ifindex = dev->ifindex;
++			}
++			route->tuple[dir].xmit_type = FLOW_OFFLOAD_XMIT_DIRECT;
++		}
++
++		switch (path->type) {
++		case DEV_PATH_PPPOE:
++		case DEV_PATH_VLAN:
++			if (n_encaps >= NF_FLOW_TABLE_ENCAP_MAX ||
++			    i == stack.num_paths) {
++				last = true;
++				break;
++			}
++
++			route->tuple[!dir].in.num_encaps++;
++			route->tuple[!dir].in.encap[n_encaps].id = path->encap.id;
++			route->tuple[!dir].in.encap[n_encaps].proto = path->encap.proto;
++			if (path->type == DEV_PATH_PPPOE)
++				memcpy(route->tuple[dir].out.h_dest,
++				       path->encap.h_dest, ETH_ALEN);
++			break;
++		case DEV_PATH_BRIDGE:
++			switch (path->bridge.vlan_mode) {
++			case DEV_PATH_BR_VLAN_TAG:
++				if (n_encaps >= NF_FLOW_TABLE_ENCAP_MAX ||
++				    i == stack.num_paths) {
++					last = true;
++					break;
++				}
++
++				route->tuple[!dir].in.num_encaps++;
++				route->tuple[!dir].in.encap[n_encaps].id =
++					path->bridge.vlan_id;
++				route->tuple[!dir].in.encap[n_encaps].proto =
++					path->bridge.vlan_proto;
++				break;
++			case DEV_PATH_BR_VLAN_UNTAG:
++				route->tuple[!dir].in.num_encaps--;
++				break;
++			case DEV_PATH_BR_VLAN_UNTAG_HW:
++				route->tuple[!dir].in.ingress_vlans |= BIT(n_encaps - 1);
++				break;
++			case DEV_PATH_BR_VLAN_KEEP:
++				break;
++			}
++			break;
++		default:
++			last = true;
++			break;
++		}
++
++		if (last)
++			break;
++	}
++
++	*out_dev = dev;
++	route->tuple[dir].out.hw_ifindex = dev->ifindex;
++	route->tuple[!dir].in.ifindex = dev->ifindex;
++}
++
++static int
++xt_flowoffload_route_dir(struct nf_flow_route *route, const struct nf_conn *ct,
++			 enum ip_conntrack_dir dir,
++			 const struct xt_action_param *par, int ifindex)
++{
++	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;
++	}
++
++	nf_route(xt_net(par), &dst, &fl, false, xt_family(par));
++	if (!dst)
++		return -ENOENT;
++
++	route->tuple[dir].dst = dst;
++	if (dst_xfrm(dst))
++		route->tuple[dir].xmit_type = FLOW_OFFLOAD_XMIT_XFRM;
++	else
++		route->tuple[dir].xmit_type = FLOW_OFFLOAD_XMIT_NEIGH;
++
++	return 0;
++}
++
++static int
++xt_flowoffload_route(struct sk_buff *skb, const struct nf_conn *ct,
++		     const struct xt_action_param *par,
++		     struct nf_flow_route *route, enum ip_conntrack_dir dir,
++		     struct net_device **dev)
++{
++	int ret;
++
++	ret = xt_flowoffload_route_dir(route, ct, dir, par,
++				       dev[dir]->ifindex);
++	if (ret)
++		return ret;
++
++	ret = xt_flowoffload_route_dir(route, ct, !dir, par,
++				       dev[!dir]->ifindex);
++	if (ret)
++		return ret;
++
++	xt_flowoffload_route_check_path(route, ct, dir, &dev[!dir]);
++	xt_flowoffload_route_check_path(route, ct, !dir, &dev[dir]);
++
++	return 0;
++}
++
++static unsigned int
++flowoffload_tg(struct sk_buff *skb, const struct xt_action_param *par)
++{
++	struct xt_flowoffload_table *table;
++	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 = NULL;
++	struct net_device *devs[2] = {};
++	struct nf_conn *ct;
++	struct net *net;
++
++	if (xt_flowoffload_skip(skb, xt_family(par)))
++		return XT_CONTINUE;
++
++	ct = nf_ct_get(skb, &ctinfo);
++	if (ct == NULL)
++		return XT_CONTINUE;
++
++	switch (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum) {
++	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;
++	default:
++		return XT_CONTINUE;
++	}
++
++	if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
++	    ct->status & IPS_SEQ_ADJUST)
++		return XT_CONTINUE;
++
++	if (!nf_ct_is_confirmed(ct))
++		return XT_CONTINUE;
++
++	devs[dir] = xt_out(par);
++	devs[!dir] = xt_in(par);
++
++	if (!devs[dir] || !devs[!dir])
++		return XT_CONTINUE;
++
++	if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
++		return XT_CONTINUE;
++
++	dir = CTINFO2DIR(ctinfo);
++
++	if (xt_flowoffload_route(skb, ct, par, &route, dir, devs) < 0)
++		goto err_flow_route;
++
++	flow = flow_offload_alloc(ct);
++	if (!flow)
++		goto err_flow_alloc;
++
++	if (flow_offload_route_init(flow, &route) < 0)
++		goto err_flow_add;
++
++	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;
++	}
++
++	table = &flowtable[!!(info->flags & XT_FLOWOFFLOAD_HW)];
++	if (flow_offload_add(&table->ft, flow) < 0)
++		goto err_flow_add;
++
++	xt_flowoffload_check_device(table, devs[0]);
++	xt_flowoffload_check_device(table, devs[1]);
++
++	net = read_pnet(&table->ft.net);
++	if (!net)
++		write_pnet(&table->ft.net, xt_net(par));
++
++	dst_release(route.tuple[dir].dst);
++	dst_release(route.tuple[!dir].dst);
++
++	return XT_CONTINUE;
++
++err_flow_add:
++	flow_offload_free(flow);
++err_flow_alloc:
++	dst_release(route.tuple[dir].dst);
++	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;
++}
++
++static struct xt_target offload_tg_reg __read_mostly = {
++	.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 flow_offload_netdev_event(struct notifier_block *this,
++				     unsigned long event, void *ptr)
++{
++	struct xt_flowoffload_hook *hook0, *hook1;
++	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
++
++	if (event != NETDEV_UNREGISTER)
++		return NOTIFY_DONE;
++
++	spin_lock_bh(&hooks_lock);
++	hook0 = flow_offload_lookup_hook(&flowtable[0], dev);
++	if (hook0)
++		hlist_del(&hook0->list);
++
++	hook1 = flow_offload_lookup_hook(&flowtable[1], dev);
++	if (hook1)
++		hlist_del(&hook1->list);
++	spin_unlock_bh(&hooks_lock);
++
++	if (hook0) {
++		nf_unregister_net_hook(hook0->net, &hook0->ops);
++		kfree(hook0);
++	}
++
++	if (hook1) {
++		nf_unregister_net_hook(hook1->net, &hook1->ops);
++		kfree(hook1);
++	}
++
++	nf_flow_table_cleanup(dev);
++
++	return NOTIFY_DONE;
++}
++
++static struct notifier_block flow_offload_netdev_notifier = {
++	.notifier_call	= flow_offload_netdev_event,
++};
++
++static unsigned int
++nf_flow_offload_inet_hook(void *priv, struct sk_buff *skb,
++			  const struct nf_hook_state *state)
++{
++	switch (skb->protocol) {
++	case htons(ETH_P_IP):
++		return nf_flow_offload_ip_hook(priv, skb, state);
++	case htons(ETH_P_IPV6):
++		return nf_flow_offload_ipv6_hook(priv, skb, state);
++	}
++
++	return NF_ACCEPT;
++}
++
++static int nf_flow_rule_route_inet(struct net *net,
++				   const struct flow_offload *flow,
++				   enum flow_offload_tuple_dir dir,
++				   struct nf_flow_rule *flow_rule)
++{
++	const struct flow_offload_tuple *flow_tuple = &flow->tuplehash[dir].tuple;
++	int err;
++
++	switch (flow_tuple->l3proto) {
++	case NFPROTO_IPV4:
++		err = nf_flow_rule_route_ipv4(net, flow, dir, flow_rule);
++		break;
++	case NFPROTO_IPV6:
++		err = nf_flow_rule_route_ipv6(net, flow, dir, flow_rule);
++		break;
++	default:
++		err = -1;
++		break;
++	}
++
++	return err;
++}
++
++static struct nf_flowtable_type flowtable_inet = {
++	.family		= NFPROTO_INET,
++	.init		= nf_flow_table_init,
++	.setup		= nf_flow_table_offload_setup,
++	.action		= nf_flow_rule_route_inet,
++	.free		= nf_flow_table_free,
++	.hook		= nf_flow_offload_inet_hook,
++	.owner		= THIS_MODULE,
++};
++
++static int init_flowtable(struct xt_flowoffload_table *tbl)
++{
++	INIT_DELAYED_WORK(&tbl->work, xt_flowoffload_hook_work);
++	tbl->ft.type = &flowtable_inet;
++
++	return nf_flow_table_init(&tbl->ft);
++}
++
++static int __init xt_flowoffload_tg_init(void)
++{
++	int ret;
++
++	register_netdevice_notifier(&flow_offload_netdev_notifier);
++
++	ret = init_flowtable(&flowtable[0]);
++	if (ret)
++		return ret;
++
++	ret = init_flowtable(&flowtable[1]);
++	if (ret)
++		goto cleanup;
++
++	flowtable[1].ft.flags = NF_FLOWTABLE_HW_OFFLOAD;
++
++	ret = xt_register_target(&offload_tg_reg);
++	if (ret)
++		goto cleanup2;
++
++	return 0;
++
++cleanup2:
++	nf_flow_table_free(&flowtable[1].ft);
++cleanup:
++	nf_flow_table_free(&flowtable[0].ft);
++	return ret;
++}
++
++static void __exit xt_flowoffload_tg_exit(void)
++{
++	xt_unregister_target(&offload_tg_reg);
++	unregister_netdevice_notifier(&flow_offload_netdev_notifier);
++	nf_flow_table_free(&flowtable[0].ft);
++	nf_flow_table_free(&flowtable[1].ft);
++}
++
++MODULE_LICENSE("GPL");
++module_init(xt_flowoffload_tg_init);
++module_exit(xt_flowoffload_tg_exit);
+--- a/net/netfilter/nf_flow_table_core.c
++++ b/net/netfilter/nf_flow_table_core.c
+@@ -7,7 +7,6 @@
+ #include <linux/netdevice.h>
+ #include <net/ip.h>
+ #include <net/ip6_route.h>
+-#include <net/netfilter/nf_tables.h>
+ #include <net/netfilter/nf_flow_table.h>
+ #include <net/netfilter/nf_conntrack.h>
+ #include <net/netfilter/nf_conntrack_core.h>
+@@ -356,8 +355,7 @@ flow_offload_lookup(struct nf_flowtable
+ }
+ EXPORT_SYMBOL_GPL(flow_offload_lookup);
+ 
+-static int
+-nf_flow_table_iterate(struct nf_flowtable *flow_table,
++int nf_flow_table_iterate(struct nf_flowtable *flow_table,
+ 		      void (*iter)(struct flow_offload *flow, void *data),
+ 		      void *data)
+ {
+@@ -389,6 +387,7 @@ nf_flow_table_iterate(struct nf_flowtabl
+ 
+ 	return err;
+ }
++EXPORT_SYMBOL_GPL(nf_flow_table_iterate);
+ 
+ static void nf_flow_offload_gc_step(struct flow_offload *flow, void *data)
+ {
+--- /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 */
+--- a/include/net/netfilter/nf_flow_table.h
++++ b/include/net/netfilter/nf_flow_table.h
+@@ -266,6 +266,10 @@ void nf_flow_table_free(struct nf_flowta
+ 
+ void flow_offload_teardown(struct flow_offload *flow);
+ 
++int nf_flow_table_iterate(struct nf_flowtable *flow_table,
++                      void (*iter)(struct flow_offload *flow, void *data),
++                      void *data);
++
+ int nf_flow_snat_port(const struct flow_offload *flow,
+ 		      struct sk_buff *skb, unsigned int thoff,
+ 		      u8 protocol, enum flow_offload_tuple_dir dir);