[PATCH net-next 01/10] net: vxlan: add vxlan to the drop reason subsystem

[Menglong Dong <menglong8.dong@gmail.com>]

In this commit, we introduce the SKB_DROP_REASON_SUBSYS_VXLAN to make the
vxlan support skb drop reasons.

As the vxlan is a network protocol, maybe we can directly add it to the
enum skb_drop_reason instead of a subsystem?

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
 drivers/net/vxlan/drop.h          | 30 ++++++++++++++++++++++++++++++
 drivers/net/vxlan/vxlan_core.c    | 15 +++++++++++++++
 drivers/net/vxlan/vxlan_private.h |  1 +
 include/net/dropreason.h          |  6 ++++++
 4 files changed, 52 insertions(+)
 create mode 100644 drivers/net/vxlan/drop.h

diff --git a/drivers/net/vxlan/drop.h b/drivers/net/vxlan/drop.h
new file mode 100644
index 000000000000..83e10550dd6a
--- /dev/null
+++ b/drivers/net/vxlan/drop.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * VXLAN drop reason list.
+ */
+
+#ifndef VXLAN_DROP_H
+#define VXLAN_DROP_H
+#include <linux/skbuff.h>
+#include <net/dropreason.h>
+
+#define VXLAN_DROP_REASONS(R)			\
+	/* deliberate comment for trailing \ */
+
+enum vxlan_drop_reason {
+	__VXLAN_DROP_REASON = SKB_DROP_REASON_SUBSYS_VXLAN <<
+				SKB_DROP_REASON_SUBSYS_SHIFT,
+#define ENUM(x) x,
+	VXLAN_DROP_REASONS(ENUM)
+#undef ENUM
+
+	VXLAN_DROP_MAX,
+};
+
+static inline void
+vxlan_kfree_skb(struct sk_buff *skb, enum vxlan_drop_reason reason)
+{
+	kfree_skb_reason(skb, (u32)reason);
+}
+
+#endif /* VXLAN_DROP_H */
diff --git a/drivers/net/vxlan/vxlan_core.c b/drivers/net/vxlan/vxlan_core.c
index 8983e75e9881..5785902e20ce 100644
--- a/drivers/net/vxlan/vxlan_core.c
+++ b/drivers/net/vxlan/vxlan_core.c
@@ -4834,6 +4834,17 @@ static int vxlan_nexthop_event(struct notifier_block *nb,
 	return NOTIFY_DONE;
 }
 
+static const char * const vxlan_drop_reasons[] = {
+#define S(x)	[(x) & ~SKB_DROP_REASON_SUBSYS_MASK] = (#x),
+	VXLAN_DROP_REASONS(S)
+#undef S
+};
+
+static struct drop_reason_list drop_reason_list_vxlan = {
+	.reasons = vxlan_drop_reasons,
+	.n_reasons = ARRAY_SIZE(vxlan_drop_reasons),
+};
+
 static __net_init int vxlan_init_net(struct net *net)
 {
 	struct vxlan_net *vn = net_generic(net, vxlan_net_id);
@@ -4915,6 +4926,9 @@ static int __init vxlan_init_module(void)
 
 	vxlan_vnifilter_init();
 
+	drop_reasons_register_subsys(SKB_DROP_REASON_SUBSYS_VXLAN,
+				     &drop_reason_list_vxlan);
+
 	return 0;
 out4:
 	unregister_switchdev_notifier(&vxlan_switchdev_notifier_block);
@@ -4929,6 +4943,7 @@ late_initcall(vxlan_init_module);
 
 static void __exit vxlan_cleanup_module(void)
 {
+	drop_reasons_unregister_subsys(SKB_DROP_REASON_SUBSYS_VXLAN);
 	vxlan_vnifilter_uninit();
 	rtnl_link_unregister(&vxlan_link_ops);
 	unregister_switchdev_notifier(&vxlan_switchdev_notifier_block);
diff --git a/drivers/net/vxlan/vxlan_private.h b/drivers/net/vxlan/vxlan_private.h
index b35d96b78843..8720d7a1206f 100644
--- a/drivers/net/vxlan/vxlan_private.h
+++ b/drivers/net/vxlan/vxlan_private.h
@@ -8,6 +8,7 @@
 #define _VXLAN_PRIVATE_H
 
 #include <linux/rhashtable.h>
+#include "drop.h"
 
 extern unsigned int vxlan_net_id;
 extern const u8 all_zeros_mac[ETH_ALEN + 2];
diff --git a/include/net/dropreason.h b/include/net/dropreason.h
index 56cb7be92244..2e5d158d670e 100644
--- a/include/net/dropreason.h
+++ b/include/net/dropreason.h
@@ -29,6 +29,12 @@ enum skb_drop_reason_subsys {
 	 */
 	SKB_DROP_REASON_SUBSYS_OPENVSWITCH,
 
+	/**
+	 * @SKB_DROP_REASON_SUBSYS_VXLAN: vxlan drop reason, see
+	 * drivers/net/vxlan/drop.h
+	 */
+	SKB_DROP_REASON_SUBSYS_VXLAN,
+
 	/** @SKB_DROP_REASON_SUBSYS_NUM: number of subsystems defined */
 	SKB_DROP_REASON_SUBSYS_NUM
 };
-- 
2.39.2