On 15/03/2022 02:25, Tobias Waldekranz wrote:
> Make it possible to change the port state in a given MSTI by extending
> the bridge port netlink interface (RTM_SETLINK on PF_BRIDGE).The
> proposed iproute2 interface would be:
>
> bridge mst set dev <PORT> msti <MSTI> state <STATE>
>
> Current states in all applicable MSTIs can also be dumped via a
> corresponding RTM_GETLINK. The proposed iproute interface looks like
> this:
>
> $ bridge mst
> port msti
> vb1 0
> state forwarding
> 100
> state disabled
> vb2 0
> state forwarding
> 100
> state forwarding
>
> The preexisting per-VLAN states are still valid in the MST
> mode (although they are read-only), and can be queried as usual if one
> is interested in knowing a particular VLAN's state without having to
> care about the VID to MSTI mapping (in this example VLAN 20 and 30 are
> bound to MSTI 100):
>
> $ bridge -d vlan
> port vlan-id
> vb1 10
> state forwarding mcast_router 1
> 20
> state disabled mcast_router 1
> 30
> state disabled mcast_router 1
> 40
> state forwarding mcast_router 1
> vb2 10
> state forwarding mcast_router 1
> 20
> state forwarding mcast_router 1
> 30
> state forwarding mcast_router 1
> 40
> state forwarding mcast_router 1
>
> Signed-off-by: Tobias Waldekranz <tobias@xxxxxxxxxxxxxx>
> ---
> include/uapi/linux/if_bridge.h | 16 +++++
> include/uapi/linux/rtnetlink.h | 1 +
> net/bridge/br_mst.c | 127 +++++++++++++++++++++++++++++++++
> net/bridge/br_netlink.c | 44 +++++++++++-
> net/bridge/br_private.h | 23 ++++++
> 5 files changed, 210 insertions(+), 1 deletion(-)
>
[snip]
> diff --git a/net/bridge/br_mst.c b/net/bridge/br_mst.c
> index 78ef5fea4d2b..355ad102d6b1 100644
> --- a/net/bridge/br_mst.c
> +++ b/net/bridge/br_mst.c
> @@ -124,3 +124,130 @@ int br_mst_set_enabled(struct net_bridge *br, bool on,
> br_opt_toggle(br, BROPT_MST_ENABLED, on);
> return 0;
> }
> +
> +size_t br_mst_info_size(const struct net_bridge_vlan_group *vg)
> +{
> + DECLARE_BITMAP(seen, VLAN_N_VID) = { 0 };
> + const struct net_bridge_vlan *v;
> + size_t sz;
> +
> + /* IFLA_BRIDGE_MST */
> + sz = nla_total_size(0);
> +
> + list_for_each_entry(v, &vg->vlan_list, vlist) {
Note that rtnl_calcit() (which ends up indirectly using this function) is called
only with rcu so you need to use list_for_each_entry_rcu() here.
> + if (test_bit(v->brvlan->msti, seen))
> + continue;
> +
> + /* IFLA_BRIDGE_MST_ENTRY */
> + sz += nla_total_size(0) +
> + /* IFLA_BRIDGE_MST_ENTRY_MSTI */
> + nla_total_size(sizeof(u16)) +
> + /* IFLA_BRIDGE_MST_ENTRY_STATE */
> + nla_total_size(sizeof(u8));
> +
> + __set_bit(v->brvlan->msti, seen);
> + }
> +
> + return sz;
> +}
> +
