From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 20 Feb 2018 15:56:02 +0100
Subject: [PATCH] netfilter: add xt_OFFLOAD 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
@@ -702,8 +702,6 @@ 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
@@ -712,11 +710,12 @@ 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.
@@ -1005,6 +1004,15 @@ 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
@@ -144,6 +144,7 @@ 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 +1,427 @@
+/*
+ * Copyright (C) 2018 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>
+
+static struct nf_flowtable nf_flowtable;
+static HLIST_HEAD(hooks);
+static DEFINE_SPINLOCK(hooks_lock);
+static struct delayed_work hook_work;
+
+struct xt_flowoffload_hook {
+ struct hlist_node list;
+ struct nf_hook_ops ops;
+ struct net *net;
+ bool registered;
+ bool used;
+};
+
+static unsigned int
+xt_flowoffload_net_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;
+}
+
+int nf_flow_table_iterate(struct nf_flowtable *flow_table,
+ void (*iter)(struct flow_offload *flow, void *data),
+ void *data);
+
+static int
+xt_flowoffload_create_hook(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 = &nf_flowtable;
+ ops->hook = xt_flowoffload_net_hook;
+ ops->dev = dev;
+
+ hlist_add_head(&hook->list, &hooks);
+ mod_delayed_work(system_power_efficient_wq, &hook_work, 0);
+
+ return 0;
+}
+
+static struct xt_flowoffload_hook *
+flow_offload_lookup_hook(struct net_device *dev)
+{
+ struct xt_flowoffload_hook *hook;
+
+ hlist_for_each_entry(hook, &hooks, list) {
+ if (hook->ops.dev == dev)
+ return hook;
+ }
+
+ return NULL;
+}
+
+static void
+xt_flowoffload_check_device(struct net_device *dev)
+{
+ struct xt_flowoffload_hook *hook;
+
+ spin_lock_bh(&hooks_lock);
+ hook = flow_offload_lookup_hook(dev);
+ if (hook)
+ hook->used = true;
+ else
+ xt_flowoffload_create_hook(dev);
+ spin_unlock_bh(&hooks_lock);
+}
+
+static void
+xt_flowoffload_register_hooks(void)
+{
+ struct xt_flowoffload_hook *hook;
+
+restart:
+ hlist_for_each_entry(hook, &hooks, list) {
+ if (hook->registered)
+ continue;
+
