Re: [PATCH v4 net-next 03/15] net: bridge: mst: Support setting and reporting MST port states

[Tobias Waldekranz <tobias@waldekranz.com>]

On Tue, Mar 15, 2022 at 18:54, Vladimir Oltean <olteanv@gmail.com> wrote:
> On Tue, Mar 15, 2022 at 01:25:31AM +0100, 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@waldekranz.com>
>> ---
>> +static int br_mst_process_one(struct net_bridge_port *p,
>> +			      const struct nlattr *attr,
>> +			      struct netlink_ext_ack *extack)
>> +{
>> +	struct nlattr *tb[IFLA_BRIDGE_MST_ENTRY_MAX + 1];
>> +	u16 msti;
>> +	u8 state;
>> +	int err;
>> +
>> +	err = nla_parse_nested(tb, IFLA_BRIDGE_MST_ENTRY_MAX, attr,
>> +			       br_mst_nl_policy, extack);
>> +	if (err)
>> +		return err;
>> +
>> +	if (!tb[IFLA_BRIDGE_MST_ENTRY_MSTI]) {
>> +		NL_SET_ERR_MSG_MOD(extack, "MSTI not specified");
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (!tb[IFLA_BRIDGE_MST_ENTRY_STATE]) {
>> +		NL_SET_ERR_MSG_MOD(extack, "State not specified");
>> +		return -EINVAL;
>> +	}
>> +
>> +	msti = nla_get_u16(tb[IFLA_BRIDGE_MST_ENTRY_MSTI]);
>> +	state = nla_get_u8(tb[IFLA_BRIDGE_MST_ENTRY_STATE]);
>> +
>> +	br_mst_set_state(p, msti, state);
>
> Is there any reason why this isn't propagating the error?

No, we definitely should. Thanks.

>> +	return 0;
>> +}