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 | 2 +
include/net/netfilter/nf_conntrack.h | 4 ++
net/core/lwtunnel.c | 3 ++
net/netfilter/Makefile | 2 +-
net/netfilter/nf_conntrack_lwtunnel.c | 52 +++++++++++++++++++
net/netfilter/nf_conntrack_standalone.c | 8 +++
7 files changed, 77 insertions(+), 1 deletion(-)
create mode 100644 net/netfilter/nf_conntrack_lwtunnel.c
diff --git a/Documentation/networking/nf_conntrack-sysctl.rst b/Documentation/networking/nf_conntrack-sysctl.rst
index d31ed6c1cb0d..5afa4603aa4b 100644
--- a/Documentation/networking/nf_conntrack-sysctl.rst
+++ b/Documentation/networking/nf_conntrack-sysctl.rst
@@ -30,6 +30,13 @@ nf_conntrack_checksum - BOOLEAN
in INVALID state. If this is enabled, such packets will not be
considered for connection tracking.
+nf_conntrack_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_conntrack_count - INTEGER (read-only)
Number of currently allocated flow entries.
diff --git a/include/net/lwtunnel.h b/include/net/lwtunnel.h
index 05cfd6ff6528..c6029f7eec14 100644
--- a/include/net/lwtunnel.h
+++ b/include/net/lwtunnel.h
@@ -51,6 +51,8 @@ struct lwtunnel_encap_ops {
};
#ifdef CONFIG_LWTUNNEL
+DECLARE_STATIC_KEY_FALSE(nf_ct_lwtunnel_enabled);
+
void lwtstate_free(struct lwtunnel_state *lws);
static inline struct lwtunnel_state *
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index cc663c68ddc4..d2a74fc75346 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -360,4 +360,8 @@ static inline struct nf_conntrack_net *nf_ct_pernet(const struct net *net)
#define MODULE_ALIAS_NFCT_HELPER(helper) \
MODULE_ALIAS("nfct-helper-" helper)
+int nf_conntrack_lwtunnel_sysctl_handler(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp,
+ loff_t *ppos);
+
#endif /* _NF_CONNTRACK_H */
diff --git a/net/core/lwtunnel.c b/net/core/lwtunnel.c
index 8ec7d13d2860..8be3274e30ec 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_ct_lwtunnel_enabled);
+EXPORT_SYMBOL_GPL(nf_ct_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..dd784b872c61 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -4,7 +4,7 @@ netfilter-objs := core.o nf_log.o nf_queue.o nf_sockopt.o utils.o
nf_conntrack-y := nf_conntrack_core.o nf_conntrack_standalone.o nf_conntrack_expect.o nf_conntrack_helper.o \
nf_conntrack_proto.o nf_conntrack_proto_generic.o nf_conntrack_proto_tcp.o nf_conntrack_proto_udp.o \
nf_conntrack_proto_icmp.o \
- nf_conntrack_extend.o nf_conntrack_acct.o nf_conntrack_seqadj.o
+ nf_conntrack_extend.o nf_conntrack_acct.o nf_conntrack_seqadj.o nf_conntrack_lwtunnel.o
nf_conntrack-$(subst m,y,$(CONFIG_IPV6)) += nf_conntrack_proto_icmpv6.o
nf_conntrack-$(CONFIG_NF_CONNTRACK_TIMEOUT) += nf_conntrack_timeout.o
diff --git a/net/netfilter/nf_conntrack_lwtunnel.c b/net/netfilter/nf_conntrack_lwtunnel.c
new file mode 100644
index 000000000000..cddbf8c5883a
--- /dev/null
+++ b/net/netfilter/nf_conntrack_lwtunnel.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/sysctl.h>
+#include <net/lwtunnel.h>
+#include <net/netfilter/nf_conntrack.h>
+
+static inline int nf_conntrack_lwtunnel_get(void)
+{
+ if (static_branch_unlikely(&nf_ct_lwtunnel_enabled))
+ return 1;
+ else
+ return 0;
+}
+
+static inline int nf_conntrack_lwtunnel_set(int enable)
+{
+ if (static_branch_unlikely(&nf_ct_lwtunnel_enabled)) {
+ if (!enable)
+ return -EPERM;
+ } else if (enable) {
+ static_branch_enable(&nf_ct_lwtunnel_enabled);
+ }
+
+ return 0;
+}
+
+int nf_conntrack_lwtunnel_sysctl_handler(struct ctl_table *table, int write,
+ void *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int proc_nf_ct_lwtunnel_enabled = 0;
+ struct ctl_table tmp = {
+ .procname = table->procname,
+ .data = &proc_nf_ct_lwtunnel_enabled,
+ .maxlen = sizeof(int),
+ .mode = table->mode,
+ .extra1 = SYSCTL_ZERO,
+ .extra2 = SYSCTL_ONE,
+ };
+ int ret;
+
+ if (!write)
+ proc_nf_ct_lwtunnel_enabled = nf_conntrack_lwtunnel_get();
+
+ ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
+
+ if (write && ret == 0)
+ ret = nf_conntrack_lwtunnel_set(proc_nf_ct_lwtunnel_enabled);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_lwtunnel_sysctl_handler);
\ No newline at end of file
diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c
index 214d9f9e499b..f20568496ef0 100644
--- a/net/netfilter/nf_conntrack_standalone.c
+++ b/net/netfilter/nf_conntrack_standalone.c
@@ -552,6 +552,7 @@ enum nf_ct_sysctl_index {
NF_SYSCTL_CT_COUNT,
NF_SYSCTL_CT_BUCKETS,
NF_SYSCTL_CT_CHECKSUM,
+ NF_SYSCTL_CT_LWTUNNEL,
NF_SYSCTL_CT_LOG_INVALID,
NF_SYSCTL_CT_EXPECT_MAX,
NF_SYSCTL_CT_ACCT,
@@ -650,6 +651,13 @@ static struct ctl_table nf_ct_sysctl_table[] = {
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
+ [NF_SYSCTL_CT_LWTUNNEL] = {
+ .procname = "nf_conntrack_lwtunnel",
+ .data = NULL,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = nf_conntrack_lwtunnel_sysctl_handler,
+ },
[NF_SYSCTL_CT_LOG_INVALID] = {
.procname = "nf_conntrack_log_invalid",
.data = &init_net.ct.sysctl_log_invalid,
--
2.25.1
