The forwarding table binary interface (my bad choice), only exposes the port number of the first 8 bits. The bridge code was limited to 256 ports at the time, but now the kernel supports up 1024 ports, so the upper bits are lost when doing: brctl showmacs The fix is to squeeze the extra bits into small hole left in data structure, to maintain binary compatiablity. Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxxxx> --- a/include/linux/if_bridge.h 2008-04-28 15:27:05.000000000 -0700 +++ b/include/linux/if_bridge.h 2008-04-28 15:31:38.000000000 -0700 @@ -97,7 +97,9 @@ struct __fdb_entry __u8 port_no; __u8 is_local; __u32 ageing_timer_value; - __u32 unused; + __u8 port_hi; + __u8 pad0; + __u16 unused; }; #ifdef __KERNEL__ --- a/net/bridge/br_fdb.c 2008-04-28 15:27:05.000000000 -0700 +++ b/net/bridge/br_fdb.c 2008-04-28 15:31:38.000000000 -0700 @@ -285,7 +285,11 @@ int br_fdb_fillbuf(struct net_bridge *br /* convert from internal format to API */ memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN); + + /* due to ABI compat need to split into hi/lo */ fe->port_no = f->dst->port_no; + fe->port_hi = f->dst->port_no >> 8; + fe->is_local = f->is_local; if (!f->is_static) fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer); _______________________________________________ Bridge mailing list Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/bridge
