[net-next,v4,2/7] rtnl: add helper to check if a notification is needed

Commit Message

Pedro Tammela Dec. 8, 2023, 7:28 p.m. UTC

From: Victor Nogueira <[e-mail]>

Building on the rtnl_has_listeners helper, add the rtnl_notify_needed
helper to check if we can bail out early in the notification routines.

Reviewed-by: Jiri Pirko <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Signed-off-by: Victor Nogueira <[e-mail]>
Signed-off-by: Pedro Tammela <[e-mail]>
---
 include/linux/rtnetlink.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Patch

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index a7d757e96c55..0cbbbded0331 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -137,4 +137,19 @@  static inline int rtnl_has_listeners(const struct net *net, u32 group)
 	return netlink_has_listeners(rtnl, group);
 }
 
+/**
+ * rtnl_notify_needed - check if notification is needed
+ * @net: Pointer to the net namespace
+ * @nlflags: netlink ingress message flags
+ * @group: rtnl group
+ *
+ * Based on the ingress message flags and rtnl group, returns true
+ * if a notification is needed, false otherwise.
+ */
+static inline bool
+rtnl_notify_needed(const struct net *net, u16 nlflags, u32 group)
+{
+	return (nlflags & NLM_F_ECHO) || rtnl_has_listeners(net, group);
+}
+
 #endif	/* __LINUX_RTNETLINK_H */