[PATCH net-next 4/4] net: bridge: add a flag to avoid refreshing fdb when changing/adding

[Nikolay Aleksandrov]

When we modify or create a new fdb entry sometimes we want to avoid
refreshing its activity in order to track it properly. One example is
when a mac is received from EVPN multi-homing peer by FRR, which doesn't
want to change local activity accounting. It makes it static and sets a
flag to track its activity.

Signed-off-by: Nikolay Aleksandrov <niko...@cumulusnetworks.com>
---
 include/uapi/linux/neighbour.h | 1 +
 net/bridge/br_fdb.c            | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
index 21e569297355..dc8b72201f6c 100644
--- a/include/uapi/linux/neighbour.h
+++ b/include/uapi/linux/neighbour.h
@@ -191,6 +191,7 @@ enum {
 enum {
        NFEA_UNSPEC,
        NFEA_ACTIVITY_NOTIFY,
+       NFEA_DONT_REFRESH,
        __NFEA_MAX
 };
 #define NFEA_MAX (__NFEA_MAX - 1)
diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
index 642deb57c064..9db504baa094 100644
--- a/net/bridge/br_fdb.c
+++ b/net/bridge/br_fdb.c
@@ -860,6 +860,7 @@ static int fdb_add_entry(struct net_bridge *br, struct 
net_bridge_port *source,
                         struct nlattr *nfea_tb[])
 {
        bool is_sticky = !!(ndm->ndm_flags & NTF_STICKY);
+       bool refresh = !nfea_tb[NFEA_DONT_REFRESH];
        struct net_bridge_fdb_entry *fdb;
        u16 state = ndm->ndm_state;
        bool modified = false;
@@ -937,7 +938,8 @@ static int fdb_add_entry(struct net_bridge *br, struct 
net_bridge_port *source,
 
        fdb->used = jiffies;
        if (modified) {
-               fdb->updated = jiffies;
+               if (refresh)
+                       fdb->updated = jiffies;
                fdb_notify(br, fdb, RTM_NEWNEIGH, true);
        }
 
@@ -977,6 +979,7 @@ static int __br_fdb_add(struct ndmsg *ndm, struct 
net_bridge *br,
 
 static const struct nla_policy br_nda_fdb_pol[NFEA_MAX + 1] = {
        [NFEA_ACTIVITY_NOTIFY]  = { .type = NLA_U8 },
+       [NFEA_DONT_REFRESH]     = { .type = NLA_FLAG },
 };
 
 /* Add new permanent fdb entry with RTM_NEWNEIGH */
-- 
2.25.4