Re: [PATCH RFC 1/7] net: bridge: extend the process of special frames
From: henrik.bjoernlund@xxxxxxxxxxxxx
Date: Tue Sep 15 2020 - 04:26:31 EST
Thanks for your review. I will update in the next version as suggested.
Regards
Henrik
The 09/08/2020 12:12, Nikolay Aleksandrov wrote:
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>
> On Fri, 2020-09-04 at 09:15 +0000, Henrik Bjoernlund wrote:
> > This patch extends the processing of frames in the bridge. Currently MRP
> > frames needs special processing and the current implementation doesn't
> > allow a nice way to process different frame types. Therefore try to
> > improve this by adding a list that contains frame types that need
> > special processing. This list is iterated for each input frame and if
> > there is a match based on frame type then these functions will be called
> > and decide what to do with the frame. It can process the frame then the
> > bridge doesn't need to do anything or don't process so then the bridge
> > will do normal forwarding.
> >
> > Signed-off-by: Henrik Bjoernlund <henrik.bjoernlund@xxxxxxxxxxxxx>
> > ---
> > net/bridge/br_device.c | 1 +
> > net/bridge/br_input.c | 31 ++++++++++++++++++++++++++++++-
> > net/bridge/br_mrp.c | 19 +++++++++++++++----
> > net/bridge/br_private.h | 18 ++++++++++++------
> > 4 files changed, 58 insertions(+), 11 deletions(-)
> >
>
> Hi,
> First I must say I do like this approach, thanks for generalizing it.
> You can switch to a hlist so that there's just 1 pointer in the head.
> I don't think you need list when you're walking only in one direction.
> A few more minor comments below.
>
> > diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c
> > index 9a2fb4aa1a10..a9232db03108 100644
> > --- a/net/bridge/br_device.c
> > +++ b/net/bridge/br_device.c
> > @@ -473,6 +473,7 @@ 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);
> > + INIT_LIST_HEAD(&br->ftype_list);
> > #if IS_ENABLED(CONFIG_BRIDGE_MRP)
> > INIT_LIST_HEAD(&br->mrp_list);
> > #endif
> > diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
> > index 59a318b9f646..0f475b21094c 100644
> > --- a/net/bridge/br_input.c
> > +++ b/net/bridge/br_input.c
> > @@ -254,6 +254,21 @@ static int nf_hook_bridge_pre(struct sk_buff *skb, struct sk_buff **pskb)
> > return RX_HANDLER_CONSUMED;
> > }
> >
> > +/* Return 0 if the frame was not processed otherwise 1
> > + * note: already called with rcu_read_lock
> > + */
> > +static int br_process_frame_type(struct net_bridge_port *p,
> > + struct sk_buff *skb)
> > +{
> > + struct br_frame_type *tmp;
> > +
> > + list_for_each_entry_rcu(tmp, &p->br->ftype_list, list) {
> > + if (unlikely(tmp->type == skb->protocol))
> > + return tmp->func(p, skb);
> > + }
>
> Nit: you can drop the {}.
>
> > + return 0;
> > +}
> > +
> > /*
> > * Return NULL if skb is handled
> > * note: already called with rcu_read_lock
> > @@ -343,7 +358,7 @@ static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
> > }
> > }
> >
> > - if (unlikely(br_mrp_process(p, skb)))
> > + if (unlikely(br_process_frame_type(p, skb)))
> > return RX_HANDLER_PASS;
> >
> > forward:
> > @@ -380,3 +395,17 @@ rx_handler_func_t *br_get_rx_handler(const struct net_device *dev)
> >
> > return br_handle_frame;
> > }
> > +
> > +void br_add_frame(struct net_bridge *br, struct br_frame_type *ft)
> > +{
> > + list_add_rcu(&ft->list, &br->ftype_list);
> > +}
> > +
> > +void br_del_frame(struct net_bridge *br, struct br_frame_type *ft)
> > +{
> > + struct br_frame_type *tmp;
> > +
> > + list_for_each_entry(tmp, &br->ftype_list, list)
> > + if (ft == tmp)
> > + list_del_rcu(&ft->list);
> > +}
> > diff --git a/net/bridge/br_mrp.c b/net/bridge/br_mrp.c
> > index b36689e6e7cb..0428e1785041 100644
> > --- a/net/bridge/br_mrp.c
> > +++ b/net/bridge/br_mrp.c
> > @@ -6,6 +6,13 @@
> > static const u8 mrp_test_dmac[ETH_ALEN] = { 0x1, 0x15, 0x4e, 0x0, 0x0, 0x1 };
> > static const u8 mrp_in_test_dmac[ETH_ALEN] = { 0x1, 0x15, 0x4e, 0x0, 0x0, 0x3 };
> >
> > +static int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb);
> > +
> > +static struct br_frame_type mrp_frame_type __read_mostly = {
> > + .type = cpu_to_be16(ETH_P_MRP),
> > + .func = br_mrp_process,
> > +};
> > +
> > static bool br_mrp_is_ring_port(struct net_bridge_port *p_port,
> > struct net_bridge_port *s_port,
> > struct net_bridge_port *port)
> > @@ -445,6 +452,9 @@ static void br_mrp_del_impl(struct net_bridge *br, struct br_mrp *mrp)
> >
> > list_del_rcu(&mrp->list);
> > kfree_rcu(mrp, rcu);
> > +
> > + if (list_empty(&br->mrp_list))
> > + br_del_frame(br, &mrp_frame_type);
> > }
> >
> > /* Adds a new MRP instance.
> > @@ -493,6 +503,9 @@ int br_mrp_add(struct net_bridge *br, struct br_mrp_instance *instance)
> > spin_unlock_bh(&br->lock);
> > rcu_assign_pointer(mrp->s_port, p);
> >
> > + if (list_empty(&br->mrp_list))
> > + br_add_frame(br, &mrp_frame_type);
> > +
> > INIT_DELAYED_WORK(&mrp->test_work, br_mrp_test_work_expired);
> > INIT_DELAYED_WORK(&mrp->in_test_work, br_mrp_in_test_work_expired);
> > list_add_tail_rcu(&mrp->list, &br->mrp_list);
> > @@ -1172,15 +1185,13 @@ static int br_mrp_rcv(struct net_bridge_port *p,
> > * normal forwarding.
> > * note: already called with rcu_read_lock
> > */
> > -int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb)
> > +static int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb)
> > {
> > /* If there is no MRP instance do normal forwarding */
> > if (likely(!(p->flags & BR_MRP_AWARE)))
> > goto out;
> >
> > - if (unlikely(skb->protocol == htons(ETH_P_MRP)))
> > - return br_mrp_rcv(p, skb, p->dev);
> > -
> > + return br_mrp_rcv(p, skb, p->dev);
> > out:
> > return 0;
> > }
> > diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
> > index baa1500f384f..e67c6d9e8bea 100644
> > --- a/net/bridge/br_private.h
> > +++ b/net/bridge/br_private.h
> > @@ -89,6 +89,13 @@ struct bridge_mcast_stats {
> > };
> > #endif
> >
> > +struct br_frame_type {
> > + __be16 type;
> > + int (*func)(struct net_bridge_port *port,
> > + struct sk_buff *skb);
>
> Perhaps frame_handler or something similar would be a better name for the
> callback ?
>
> > + struct list_head list;
> > +};
> > +
> > struct br_vlan_stats {
> > u64 rx_bytes;
> > u64 rx_packets;
> > @@ -433,6 +440,8 @@ struct net_bridge {
> > #endif
> > struct hlist_head fdb_list;
> >
> > + struct list_head ftype_list;
>
> Could you please expand this to frame_type_list ?
>
> > +
> > #if IS_ENABLED(CONFIG_BRIDGE_MRP)
> > struct list_head mrp_list;
> > #endif
> > @@ -708,6 +717,9 @@ int nbp_backup_change(struct net_bridge_port *p, struct net_device *backup_dev);
> > int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb);
> > rx_handler_func_t *br_get_rx_handler(const struct net_device *dev);
> >
> > +void br_add_frame(struct net_bridge *br, struct br_frame_type *ft);
> > +void br_del_frame(struct net_bridge *br, struct br_frame_type *ft);
> > +
> > static inline bool br_rx_handler_check_rcu(const struct net_device *dev)
> > {
> > return rcu_dereference(dev->rx_handler) == br_get_rx_handler(dev);
> > @@ -1320,7 +1332,6 @@ extern int (*br_fdb_test_addr_hook)(struct net_device *dev, unsigned char *addr)
> > #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);
> > int br_mrp_fill_info(struct sk_buff *skb, struct net_bridge *br);
> > @@ -1332,11 +1343,6 @@ static inline int br_mrp_parse(struct net_bridge *br, struct net_bridge_port *p,
> > 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 false;
>
--
/Henrik