Re: [RFC net-next v5 9/9] bridge: mrp: Integrate MRP into the bridge

From: Horatiu Vultur
Date: Sat Apr 18 2020 - 10:45:46 EST


The 04/18/2020 11:25, Nikolay Aleksandrov wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> On 14/04/2020 14:26, Horatiu Vultur wrote:
> > To integrate MRP into the bridge, the bridge needs to do the following:
> > - add new flag(BR_MPP_AWARE) to the net bridge ports, this bit will be set when
> > the port is added to an MRP instance. In this way it knows if the frame was
> > received on MRP ring port
> > - detect if the MRP frame was received on MRP ring port in that case it would be
> > processed otherwise just forward it as usual.
> > - enable parsing of MRP
> > - before whenever the bridge was set up, it would set all the ports in
> > forwarding state. Add an extra check to not set ports in forwarding state if
> > the port is an MRP ring port. The reason of this change is that if the MRP
> > instance initially sets the port in blocked state by setting the bridge up it
> > would overwrite this setting.
> >
> > Signed-off-by: Horatiu Vultur <horatiu.vultur@xxxxxxxxxxxxx>
> > ---
> > include/linux/if_bridge.h | 1 +
> > net/bridge/br_device.c | 3 +++
> > net/bridge/br_if.c | 2 ++
> > net/bridge/br_input.c | 3 +++
> > net/bridge/br_netlink.c | 5 +++++
> > net/bridge/br_private.h | 35 +++++++++++++++++++++++++++++++++++
> > net/bridge/br_stp.c | 6 ++++++
> > net/bridge/br_stp_if.c | 5 +++++
> > 8 files changed, 60 insertions(+)
> >
> > diff --git a/include/linux/if_bridge.h b/include/linux/if_bridge.h
> > index 9e57c4411734..10baa9efdae8 100644
> > --- a/include/linux/if_bridge.h
> > +++ b/include/linux/if_bridge.h
> > @@ -47,6 +47,7 @@ struct br_ip_list {
> > #define BR_BCAST_FLOOD BIT(14)
> > #define BR_NEIGH_SUPPRESS BIT(15)
> > #define BR_ISOLATED BIT(16)
> > +#define BR_MRP_AWARE BIT(17)
> >
> > #define BR_DEFAULT_AGEING_TIME (300 * HZ)
> >
> > diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
> > index 0e3dbc5f3c34..8ec1362588af 100644
> > --- a/net/bridge/br_device.c
> > +++ b/net/bridge/br_device.c
> > @@ -463,6 +463,9 @@ void br_dev_setup(struct net_device *dev)
> > spin_lock_init(&br->lock);
> > INIT_LIST_HEAD(&br->port_list);
> > INIT_HLIST_HEAD(&br->fdb_list);
> > +#if IS_ENABLED(CONFIG_BRIDGE_MRP)
> > + INIT_LIST_HEAD(&br->mrp_list);
> > +#endif
> > spin_lock_init(&br->hash_lock);
> >
> > br->bridge_id.prio[0] = 0x80;
> > diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c
> > index 4fe30b182ee7..ca685c0cdf95 100644
> > --- a/net/bridge/br_if.c
> > +++ b/net/bridge/br_if.c
> > @@ -333,6 +333,8 @@ static void del_nbp(struct net_bridge_port *p)
> > br_stp_disable_port(p);
> > spin_unlock_bh(&br->lock);
> >
> > + br_mrp_port_del(br, p);
> > +
> > br_ifinfo_notify(RTM_DELLINK, NULL, p);
> >
> > list_del_rcu(&p->list);
> > diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
> > index fcc260840028..d5c34f36f0f4 100644
> > --- a/net/bridge/br_input.c
> > +++ b/net/bridge/br_input.c
> > @@ -342,6 +342,9 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
> > }
> > }
> >
> > + if (unlikely(br_mrp_process(p, skb)))
> > + return RX_HANDLER_PASS;
> > +
> > forward:
> > switch (p->state) {
> > case BR_STATE_FORWARDING:
> > diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c
> > index 43dab4066f91..8826fcd1eb76 100644
> > --- a/net/bridge/br_netlink.c
> > +++ b/net/bridge/br_netlink.c
> > @@ -669,6 +669,11 @@ static int br_afspec(struct net_bridge *br,
> > if (err)
> > return err;
> > break;
> > + case IFLA_BRIDGE_MRP:
> > + err = br_mrp_parse(br, p, attr, cmd, extack);
> > + if (err)
> > + return err;
> > + break;
> > }
> > }
> >
> > diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
> > index 1f97703a52ff..5835828320b6 100644
> > --- a/net/bridge/br_private.h
> > +++ b/net/bridge/br_private.h
> > @@ -428,6 +428,10 @@ struct net_bridge {
> > int offload_fwd_mark;
> > #endif
> > struct hlist_head fdb_list;
> > +
> > +#if IS_ENABLED(CONFIG_BRIDGE_MRP)
> > + struct list_head __rcu mrp_list;
> > +#endif
> > };
> >
> > struct br_input_skb_cb {
> > @@ -1304,6 +1308,37 @@ unsigned long br_timer_value(const struct timer_list *timer);
> > extern int (*br_fdb_test_addr_hook)(struct net_device *dev, unsigned char *addr);
> > #endif
> >
> > +/* br_mrp.c */
> > +#if IS_ENABLED(CONFIG_BRIDGE_MRP)
> > +int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p,
> > + struct nlattr *attr, int cmd, struct netlink_ext_ack *extack);
> > +int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb);
> > +bool br_mrp_enabled(struct net_bridge *br);
> > +void br_mrp_port_del(struct net_bridge *br, struct net_bridge_port *p);
> > +#else
> > +static inline int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p,
> > + struct nlattr *attr, int cmd,
> > + struct netlink_ext_ack *extack)
> > +{
> > + return -EOPNOTSUPP;
> > +}
> > +
> > +static inline int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb)
> > +{
> > + return 0;
> > +}
> > +
> > +static inline bool br_mrp_enabled(struct net_bridge *br)
> > +{
> > + return 0;
> > +}
> > +
> > +static inline void br_mrp_port_del(struct net_bridge *br,
> > + struct net_bridge_port *p)
> > +{
> > +}
> > +#endif
> > +
> > /* br_netlink.c */
> > extern struct rtnl_link_ops br_link_ops;
> > int br_netlink_init(void);
> > diff --git a/net/bridge/br_stp.c b/net/bridge/br_stp.c
> > index 1f14b8455345..3e88be7aa269 100644
> > --- a/net/bridge/br_stp.c
> > +++ b/net/bridge/br_stp.c
> > @@ -36,6 +36,12 @@ void br_set_state(struct net_bridge_port *p, unsigned int state)
> > };
> > int err;
> >
> > + /* Don't change the state of the ports if they are driven by a different
> > + * protocol.
> > + */
> > + if (p->flags & BR_MRP_AWARE)
> > + return;
> > +
> > p->state = state;
> > err = switchdev_port_attr_set(p->dev, &attr);
> > if (err && err != -EOPNOTSUPP)
> > diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
> > index d174d3a566aa..542b212d5033 100644
> > --- a/net/bridge/br_stp_if.c
> > +++ b/net/bridge/br_stp_if.c
> > @@ -200,6 +200,11 @@ void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
> > {
> > ASSERT_RTNL();
> >
> > + if (br_mrp_enabled(br)) {
> > + br_warn(br, "STP can't be enabled if MRP is already enabled\n");
>
> It'd be nice if this can be returned in an extack if this function is called from netlink.
> In addition this must return an error - otherwise writing to the sysfs file would be successful
> while nothing will have changed, so the user will think it worked. Check out set_stp_state().
> You can drop the br_warn, just make sure to return proper extack error from netlink (it is
> the preferred interface over sysfs, so simply returning an error for sysfs would be enough).

I will change the declaration of this function to return an error code
and also add the extack as argument.

>
> > + return;
> > + }
> > +
> > if (val) {
> > if (br->stp_enabled == BR_NO_STP)
> > br_stp_start(br);
> >
>

--
/Horatiu