On Sat, Apr 09, 2022 at 01:58:55PM +0300, Nikolay Aleksandrov wrote:
> Add support for fdb flush filtering based on ndm flags and state. The
> new attributes allow users to specify a mask and value which are mapped
> to bridge-specific flags. NTF_USE is used to represent added_by_user
> flag since it sets it on fdb add and we don't have a 1:1 mapping for it.
>
> Signed-off-by: Nikolay Aleksandrov <[email protected]>
> ---
> include/uapi/linux/if_bridge.h | 4 +++
> net/bridge/br_fdb.c | 55 ++++++++++++++++++++++++++++++++++
> 2 files changed, 59 insertions(+)
>
> diff --git a/include/uapi/linux/if_bridge.h b/include/uapi/linux/if_bridge.h
> index 2f3799cf14b2..4638d7e39f2a 100644
> --- a/include/uapi/linux/if_bridge.h
> +++ b/include/uapi/linux/if_bridge.h
> @@ -815,6 +815,10 @@ enum {
> /* embedded in BRIDGE_FLUSH_FDB */
> enum {
> FDB_FLUSH_UNSPEC,
> + FDB_FLUSH_NDM_STATE,
> + FDB_FLUSH_NDM_STATE_MASK,
> + FDB_FLUSH_NDM_FLAGS,
> + FDB_FLUSH_NDM_FLAGS_MASK,
> __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 62f694a739e1..340a2ace1d5e 100644
> --- a/net/bridge/br_fdb.c
> +++ b/net/bridge/br_fdb.c
> @@ -594,8 +594,40 @@ void br_fdb_flush(struct net_bridge *br,
> rcu_read_unlock();
> }
>
> +static unsigned long __ndm_state_to_fdb_flags(u16 ndm_state)
> +{
> + unsigned long flags = 0;
> +
> + if (ndm_state & NUD_PERMANENT)
> + __set_bit(BR_FDB_LOCAL, &flags);
> + if (ndm_state & NUD_NOARP)
> + __set_bit(BR_FDB_STATIC, &flags);
> +
> + return flags;
> +}
> +
> +static unsigned long __ndm_flags_to_fdb_flags(u16 ndm_flags)
> +{
> + unsigned long flags = 0;
> +
> + if (ndm_flags & NTF_USE)
> + __set_bit(BR_FDB_ADDED_BY_USER, &flags);
> + if (ndm_flags & NTF_EXT_LEARNED)
> + __set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &flags);
> + if (ndm_flags & NTF_OFFLOADED)
> + __set_bit(BR_FDB_OFFLOADED, &flags);
> + if (ndm_flags & NTF_STICKY)
> + __set_bit(BR_FDB_STICKY, &flags);
> +
> + return flags;
> +}
> +
> static const struct nla_policy br_fdb_flush_policy[FDB_FLUSH_MAX + 1] = {
> [FDB_FLUSH_UNSPEC] = { .type = NLA_REJECT },
> + [FDB_FLUSH_NDM_STATE] = { .type = NLA_U16 },
> + [FDB_FLUSH_NDM_FLAGS] = { .type = NLA_U16 },
> + [FDB_FLUSH_NDM_STATE_MASK] = { .type = NLA_U16 },
> + [FDB_FLUSH_NDM_FLAGS_MASK] = { .type = NLA_U16 },
Might be better to use NLA_POLICY_MASK(NLA_U16, mask) and reject
unsupported states / flags instead of just ignoring them?
> };
>
> int br_fdb_flush_nlattr(struct net_bridge *br, struct nlattr *fdb_flush_attr,
> @@ -610,6 +642,29 @@ int br_fdb_flush_nlattr(struct net_bridge *br, struct
> nlattr *fdb_flush_attr,
> if (err)
> return err;
>
> + if (fdb_flush_tb[FDB_FLUSH_NDM_STATE]) {
> + u16 ndm_state = nla_get_u16(fdb_flush_tb[FDB_FLUSH_NDM_STATE]);
> +
> + desc.flags |= __ndm_state_to_fdb_flags(ndm_state);
> + }
> + if (fdb_flush_tb[FDB_FLUSH_NDM_STATE_MASK]) {
> + u16 ndm_state_mask;
> +
> + ndm_state_mask =
> nla_get_u16(fdb_flush_tb[FDB_FLUSH_NDM_STATE_MASK]);
> + desc.flags_mask |= __ndm_state_to_fdb_flags(ndm_state_mask);
> + }
> + if (fdb_flush_tb[FDB_FLUSH_NDM_FLAGS]) {
> + u16 ndm_flags = nla_get_u16(fdb_flush_tb[FDB_FLUSH_NDM_FLAGS]);
> +
> + desc.flags |= __ndm_flags_to_fdb_flags(ndm_flags);
> + }
> + if (fdb_flush_tb[FDB_FLUSH_NDM_FLAGS_MASK]) {
> + u16 ndm_flags_mask;
> +
> + 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);
> + }
> +
> 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
>
