bridge: add root port blocking

This is Linux bridge implementation of root port guard.
If BPDU is received from a leaf (edge) port, it should not
be elected as root port.

Why would you want to do this?
If using STP on a bridge and the downstream bridges are not fully
trusted; this prevents a hostile guest for rerouting traffic.

Why not just use netfilter?
Netfilter does not track of follow spanning tree decisions.
It would be difficult and error prone to try and mirror STP
resolution in netfilter module.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 5e871e4d923..7aae0179ae4 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -217,6 +217,7 @@ enum {
         IFLA_BRPORT_COST,       /* "             cost      */
         IFLA_BRPORT_MODE,       /* mode (hairpin)          */
         IFLA_BRPORT_GUARD,      /* bpdu guard              */
+        IFLA_BRPORT_PROTECT,    /* root port protection    */
         __IFLA_BRPORT_MAX
 };
 #define IFLA_BRPORT_MAX (__IFLA_BRPORT_MAX - 1)