This adds a Kconfig option to configure a default FDB learning limit
system wide, so a distributor building a special purpose kernel can
limit all created bridges by default.

The limit is only a soft default setting and overridable per bridge
using netlink.

Signed-off-by: Johannes Nixdorf <[email protected]>

---

Changes since v1:
 - Added a default limit in Kconfig. (deemed acceptable in review
   comments)

 net/bridge/Kconfig     | 13 +++++++++++++
 net/bridge/br_device.c |  2 ++
 2 files changed, 15 insertions(+)

diff --git a/net/bridge/Kconfig b/net/bridge/Kconfig
index 3c8ded7d3e84..c0d9c08088c4 100644
--- a/net/bridge/Kconfig
+++ b/net/bridge/Kconfig
@@ -84,3 +84,16 @@ config BRIDGE_CFM
          Say N to exclude this support and reduce the binary size.
 
          If unsure, say N.
+
+config BRIDGE_DEFAULT_FDB_MAX_LEARNED
+       int "Default FDB learning limit"
+       default 0
+       depends on BRIDGE
+       help
+         Sets a default limit on the number of learned FDB entries on
+         new bridges. This limit can be overwritten via netlink on a
+         per bridge basis.
+
+         The default of 0 disables the limit.
+
+         If unsure, say 0.
diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
index 8eca8a5c80c6..93f081ce8195 100644
--- a/net/bridge/br_device.c
+++ b/net/bridge/br_device.c
@@ -530,6 +530,8 @@ void br_dev_setup(struct net_device *dev)
        br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
        dev->max_mtu = ETH_MAX_MTU;
 
+       br->fdb_max_learned_entries = CONFIG_BRIDGE_DEFAULT_FDB_MAX_LEARNED;
+
        br_netfilter_rtable_init(br);
        br_stp_timer_init(br);
        br_multicast_init(br);
-- 
2.40.1

Reply via email to