kernel: fold xt_FLOWOFFLOAD fixes into the main patch

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

target/linux/generic/hack-4.14/650-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 +1,368 @@
+@@ -0,0 +1,403 @@
 +/*
 + * Copyright (C) 2018 Felix Fietkau <nbd@nbd.name>
 + *
@@ -113,6 +113,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +#include <net/ip.h>
 +#include <net/netfilter/nf_conntrack.h>
 +#include <net/netfilter/nf_flow_table.h>
++#include <net/netfilter/nf_conntrack_helper.h>
 +
 +static struct nf_flowtable nf_flowtable;
 +static HLIST_HEAD(hooks);
@@ -346,6 +347,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +	struct nf_flow_route route;
 +	struct flow_offload *flow;
 +	struct nf_conn *ct;
++	const struct nf_conn_help *help;
 +
 +	if (xt_flowoffload_skip(skb))
 +		return XT_CONTINUE;
@@ -365,7 +367,8 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +		return XT_CONTINUE;
 +	}
 +
-+	if (test_bit(IPS_HELPER_BIT, &ct->status))
++	help = nfct_help(ct);
++	if (help)
 +		return XT_CONTINUE;
 +
 +	if (ctinfo == IP_CT_NEW ||
@@ -441,10 +444,41 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +	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);
@@ -462,6 +496,7 @@ Signed-off-by: Felix Fietkau <nbd@nbd.name>
 +{
 +	xt_unregister_target(&offload_tg_reg);
 +	xt_flowoffload_table_cleanup(&nf_flowtable);
++	unregister_netdevice_notifier(&flow_offload_netdev_notifier);
 +}
 +
 +MODULE_LICENSE("GPL");