This patch introduces new sysctl toggle for enabling lightweight tunnel
netfilter hooks.
Signed-off-by: Ryoga Saito <contact@xxxxxxxxxxxx>
---
.../networking/nf_conntrack-sysctl.rst | 7 ++
include/net/lwtunnel.h | 3 +
include/net/netfilter/nf_hooks_lwtunnel.h | 15 +++++
net/core/lwtunnel.c | 3 +
net/netfilter/Makefile | 3 +
net/netfilter/nf_conntrack_standalone.c | 15 +++++
net/netfilter/nf_hooks_lwtunnel.c | 66 +++++++++++++++++++
7 files changed, 112 insertions(+)
create mode 100644 include/net/netfilter/nf_hooks_lwtunnel.h
create mode 100644 net/netfilter/nf_hooks_lwtunnel.c
diff --git a/Documentation/networking/nf_conntrack-sysctl.rst b/Documentation/networking/nf_conntrack-sysctl.rst
index 024d784157c8..34ca762ea56f 100644
--- a/Documentation/networking/nf_conntrack-sysctl.rst
+++ b/Documentation/networking/nf_conntrack-sysctl.rst
@@ -184,6 +184,13 @@ nf_conntrack_gre_timeout_stream - INTEGER (seconds)
This extended timeout will be used in case there is an GRE stream
detected.
+nf_hooks_lwtunnel - BOOLEAN
+ - 0 - disabled (default)
+ - not 0 - enabled
+
+ If this option is enabled, the lightweight tunnel netfilter hooks are
+ enabled. This option cannot be disabled once it is enabled.
+
nf_flowtable_tcp_timeout - INTEGER (seconds)
default 30
diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h
index 05cfd6ff6528..6f15e6fa154e 100644
--- a/include/net/lwtunnel.h
+++ b/include/net/lwtunnel.h
@@ -51,6 +51,9 @@ struct lwtunnel_encap_ops {
};
#ifdef CONFIG_LWTUNNEL
+
+DECLARE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
+
void lwtstate_free(struct lwtunnel_state *lws);
static inline struct lwtunnel_state *
diff --git a/include/net/netfilter/nf_hooks_lwtunnel.h b/include/net/netfilter/nf_hooks_lwtunnel.h
new file mode 100644
index 000000000000..f10ee2ccbdc8
--- /dev/null
+++ b/include/net/netfilter/nf_hooks_lwtunnel.h
@@ -0,0 +1,15 @@
+#include <linux/sysctl.h>
+#include <linux/types.h>
+
+#ifdef CONFIG_LWTUNNEL
+int nf_hooks_lwtunnel_sysctl_handler(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp,
+ loff_t *ppos);
+#else
+int nf_hooks_lwtunnel_sysctl_handler(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ return 0;
+}
+#endif
diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
index 8ec7d13d2860..3e6960b455e1 100644
--- a/net/core/lwtunnel.c
+++ b/net/core/lwtunnel.c
@@ -23,6 +23,9 @@
#include <net/ip6_fib.h>
#include <net/rtnh.h>
+DEFINE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
+EXPORT_SYMBOL_GPL(nf_hooks_lwtunnel_enabled);
+
#ifdef CONFIG_MODULES
static const char *lwtunnel_encap_str(enum lwtunnel_encap_types encap_type)
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 049890e00a3d..aab20e575ecd 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -212,3 +212,6 @@ obj-$(CONFIG_IP_SET) += ipset/
# IPVS
obj-$(CONFIG_IP_VS) += ipvs/
+
+# lwtunnel
+obj-$(CONFIG_LWTUNNEL) += nf_hooks_lwtunnel.o
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index e84b499b7bfa..7e0d956da51d 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -22,6 +22,9 @@
#include <net/netfilter/nf_conntrack_acct.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_conntrack_timestamp.h>
+#ifdef CONFIG_LWTUNNEL
+#include <net/netfilter/nf_hooks_lwtunnel.h>
+#endif
#include <linux/rculist_nulls.h>
static bool enable_hooks __read_mostly;
@@ -612,6 +615,9 @@ enum nf_ct_sysctl_index {
NF_SYSCTL_CT_PROTO_TIMEOUT_GRE,
NF_SYSCTL_CT_PROTO_TIMEOUT_GRE_STREAM,
#endif
+#ifdef CONFIG_LWTUNNEL
+ NF_SYSCTL_CT_LWTUNNEL,
+#endif
__NF_SYSCTL_CT_LAST_SYSCTL,
};
@@ -958,6 +964,15 @@ static struct ctl_table nf_ct_sysctl_table[] = {
.mode = 0644,
.proc_handler = proc_dointvec_jiffies,
},
+#endif
+#ifdef CONFIG_LWTUNNEL
+ [NF_SYSCTL_CT_LWTUNNEL] = {
+ .procname = "nf_hooks_lwtunnel",
+ .data = NULL,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = nf_hooks_lwtunnel_sysctl_handler,
+ },
#endif
{}
};
diff --git a/net/netfilter/nf_hooks_lwtunnel.c b/net/netfilter/nf_hooks_lwtunnel.c
new file mode 100644
index 000000000000..15b79469048f
--- /dev/null
+++ b/net/netfilter/nf_hooks_lwtunnel.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/sysctl.h>
+#include <net/lwtunnel.h>
+#include <net/netfilter/nf_hooks_lwtunnel.h>
+
+static inline int nf_hooks_lwtunnel_get(void)
+{
+ if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled))
+ return 1;
+ else
+ return 0;
+}
+
+static inline int nf_hooks_lwtunnel_set(int enable)
+{
+ if (static_branch_unlikely(&nf_hooks_lwtunnel_enabled)) {
+ if (!enable)
+ return -EBUSY;
+ } else if (enable) {
+ static_branch_enable(&nf_hooks_lwtunnel_enabled);
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_SYSCTL
+
+int nf_hooks_lwtunnel_sysctl_handler(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int proc_nf_hooks_lwtunnel_enabled = 0;
+ struct ctl_table tmp = {
+ .procname = table->procname,
+ .data = &proc_nf_hooks_lwtunnel_enabled,
+ .maxlen = sizeof(int),
+ .mode = table->mode,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ };
+ int ret;
+
+ if (!write)
+ proc_nf_hooks_lwtunnel_enabled = nf_hooks_lwtunnel_get();
+
+ ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
+
+ if (write && ret == 0)
+ ret = nf_hooks_lwtunnel_set(proc_nf_hooks_lwtunnel_enabled);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(nf_hooks_lwtunnel_sysctl_handler);
+
+#else // CONFIG_SYSCTL
+
+int nf_hooks_lwtunnel_sysctl_handler(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nf_hooks_lwtunnel_sysctl_handler);
+
+#endif
--
2.25.1
