kernel: add support for enabling hardware flow offload via iptables

Signed-off-by: Felix Fietkau <[email protected]>

package/network/utils/iptables/patches/800-flowoffload_target.patch

@@ -1,14 +1,71 @@
 --- /dev/null
 +++ b/extensions/libxt_FLOWOFFLOAD.c
-@@ -0,0 +1,15 @@
+@@ -0,0 +1,72 @@
++#include <stdio.h>
 +#include <xtables.h>
++#include <linux/netfilter/xt_FLOWOFFLOAD.h>
++
++enum {
++    O_HW,
++};
++
++static void offload_help(void)
++{
++	printf(
++"FLOWOFFLOAD target options:\n"
++" --hw				Enable hardware offload\n"
++	);
++}
++
++static const struct xt_option_entry offload_opts[] = {
++	{.name = "hw", .id = O_HW, .type = XTTYPE_NONE},
++	XTOPT_TABLEEND,
++};
++
++static void offload_parse(struct xt_option_call *cb)
++{
++	struct xt_flowoffload_target_info *info = cb->data;
++
++	xtables_option_parse(cb);
++	switch (cb->entry->id) {
++	case O_HW:
++		info->flags |= XT_FLOWOFFLOAD_HW;
++		break;
++	}
++}
++
++static void offload_print(const void *ip, const struct xt_entry_target *target, int numeric)
++{
++	const struct xt_flowoffload_target_info *info =
++		(const struct xt_flowoffload_target_info *)target->data;
++
++	printf(" FLOWOFFLOAD");
++	if (info->flags & XT_FLOWOFFLOAD_HW)
++		printf(" hw");
++}
++
++static void offload_save(const void *ip, const struct xt_entry_target *target)
++{
++	const struct xt_flowoffload_target_info *info =
++		(const struct xt_flowoffload_target_info *)target->data;
++
++	if (info->flags & XT_FLOWOFFLOAD_HW)
++		printf(" --hw");
++}
 +
 +static struct xtables_target offload_tg_reg[] = {
 +	{
-+		.family        = NFPROTO_UNSPEC,
-+		.name          = "FLOWOFFLOAD",
-+		.revision      = 0,
-+		.version       = XTABLES_VERSION,
++		.family		= NFPROTO_UNSPEC,
++		.name		= "FLOWOFFLOAD",
++		.revision	= 0,
++		.version	= XTABLES_VERSION,
++		.size		= XT_ALIGN(sizeof(struct xt_flowoffload_target_info)),
++		.userspacesize	= sizeof(struct xt_flowoffload_target_info),
++		.help		= offload_help,
++		.print		= offload_print,
++		.save		= offload_save,
++		.x6_parse	= offload_parse,
++		.x6_options	= offload_opts,
 +	},
 +};
 +
@@ -16,3 +73,23 @@
 +{
 +	xtables_register_targets(offload_tg_reg, ARRAY_SIZE(offload_tg_reg));
 +}
+--- /dev/null
++++ b/include/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 */

target/linux/generic/hack-4.14/650-netfilter-add-xt_OFFLOAD-target.patch

@@ -98,7 +98,7 @@ Signed-off-by: Felix Fietkau <[email protected]>
  obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o
 --- /dev/null
 +++ b/net/netfilter/xt_FLOWOFFLOAD.c
-@@ -0,0 +1,351 @@
+@@ -0,0 +1,364 @@
 +/*
 + * Copyright (C) 2018 Felix Fietkau <[email protected]>
 + *
@@ -109,6 +109,7 @@ Signed-off-by: Felix Fietkau <[email protected]>
 +#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_flow_table.h>
@@ -335,6 +336,7 @@ Signed-off-by: Felix Fietkau <[email protected]>
 +static unsigned int
 +flowoffload_tg(struct sk_buff *skb, const struct xt_action_param *par)
 +{
++	const struct xt_flowoffload_target_info *info = par->targinfo;
 +	enum ip_conntrack_info ctinfo;
 +	enum ip_conntrack_dir dir;
 +	struct nf_flow_route route;
@@ -387,6 +389,9 @@ Signed-off-by: Felix Fietkau <[email protected]>
 +	xt_flowoffload_check_device(xt_in(par));
 +	xt_flowoffload_check_device(xt_out(par));
 +
++	if (info->flags & XT_FLOWOFFLOAD_HW)
++		nf_flow_offload_hw_add(xt_net(par), flow, ct);
++
 +	return XT_CONTINUE;
 +
 +err_flow_add:
@@ -401,6 +406,11 @@ Signed-off-by: Felix Fietkau <[email protected]>
 +
 +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;
 +}
 +
@@ -408,6 +418,8 @@ Signed-off-by: Felix Fietkau <[email protected]>
 +	.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,
@@ -415,6 +427,7 @@ Signed-off-by: Felix Fietkau <[email protected]>
 +
 +static int xt_flowoffload_table_init(struct nf_flowtable *table)
 +{
++	table->flags = NF_FLOWTABLE_F_HW;
 +	nf_flow_table_init(table);
 +	return 0;
 +}
@@ -460,3 +473,23 @@ Signed-off-by: Felix Fietkau <[email protected]>
  #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 */