Re: [PATCH net-next 5/6] net: bridge: fdb: add support for flush filtering based on ifindex

[Ido Schimmel <idosch@idosch.org>]

On Sat, Apr 09, 2022 at 01:58:56PM +0300, Nikolay Aleksandrov wrote:
> Add support for fdb flush filtering based on destination ifindex. The
> ifindex must either match a port's device ifindex or the bridge's.
> 
> Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
> ---
>  include/uapi/linux/if_bridge.h | 1 +
>  net/bridge/br_fdb.c            | 7 +++++++
>  2 files changed, 8 insertions(+)
> 
> diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
> index 4638d7e39f2a..67ee12586844 100644
> --- a/include/uapi/linux/if_bridge.h
> +++ b/include/uapi/linux/if_bridge.h
> @@ -819,6 +819,7 @@ enum {
>  	FDB_FLUSH_NDM_STATE_MASK,
>  	FDB_FLUSH_NDM_FLAGS,
>  	FDB_FLUSH_NDM_FLAGS_MASK,
> +	FDB_FLUSH_PORT_IFINDEX,
>  	__FDB_FLUSH_MAX
>  };
>  #define FDB_FLUSH_MAX (__FDB_FLUSH_MAX - 1)
> diff --git a/net/bridge/br_fdb.c b/net/bridge/br_fdb.c
> index 340a2ace1d5e..53208adf7474 100644
> --- a/net/bridge/br_fdb.c
> +++ b/net/bridge/br_fdb.c
> @@ -628,6 +628,7 @@ static const struct nla_policy br_fdb_flush_policy[FDB_FLUSH_MAX + 1] = {
>  	[FDB_FLUSH_NDM_FLAGS]	= { .type = NLA_U16 },
>  	[FDB_FLUSH_NDM_STATE_MASK]	= { .type = NLA_U16 },
>  	[FDB_FLUSH_NDM_FLAGS_MASK]	= { .type = NLA_U16 },
> +	[FDB_FLUSH_PORT_IFINDEX]	= { .type = NLA_S32 },
>  };
>  
>  int br_fdb_flush_nlattr(struct net_bridge *br, struct nlattr *fdb_flush_attr,
> @@ -664,6 +665,12 @@ int br_fdb_flush_nlattr(struct net_bridge *br, struct nlattr *fdb_flush_attr,
>  		ndm_flags_mask = nla_get_u16(fdb_flush_tb[FDB_FLUSH_NDM_FLAGS_MASK]);
>  		desc.flags_mask |= __ndm_flags_to_fdb_flags(ndm_flags_mask);
>  	}
> +	if (fdb_flush_tb[FDB_FLUSH_PORT_IFINDEX]) {
> +		int port_ifidx;
> +
> +		port_ifidx = nla_get_u32(fdb_flush_tb[FDB_FLUSH_PORT_IFINDEX]);
> +		desc.port_ifindex = port_ifidx;

Commit message says "ifindex must either match a port's device ifindex
or the bridge's", but there is no validation. I realize such an
operation won't flush anything, but it's cleaner to just reject it here.

> +	}
>  
>  	br_debug(br, "flushing port ifindex: %d vlan id: %u flags: 0x%lx flags mask: 0x%lx\n",
>  		 desc.port_ifindex, desc.vlan_id, desc.flags, desc.flags_mask);
> -- 
> 2.35.1
>