linux-toradex.git/net/bridge/br_forward.c, branch v4.10

net: bridge: add per-port multicast flood flag

2016-09-02T05:48:33+00:00

Add a per-port flag to control the unknown multicast flood, similar to the
unknown unicast flood flag and break a few long lines in the netlink flag
exports.

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: change unicast boolean to exact pkt_type

2016-09-02T05:48:33+00:00

Remove the unicast flag and introduce an exact pkt_type. That would help us
for the upcoming per-port multicast flood flag and also slightly reduce the
tests in the input fast path.

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

bridge: switchdev: Add forward mark support for stacked devices

2016-08-26T20:13:36+00:00

switchdev_port_fwd_mark_set() is used to set the 'offload_fwd_mark' of
port netdevs so that packets being flooded by the device won't be
flooded twice.

It works by assigning a unique identifier (the ifindex of the first
bridge port) to bridge ports sharing the same parent ID. This prevents
packets from being flooded twice by the same switch, but will flood
packets through bridge ports belonging to a different switch.

This method is problematic when stacked devices are taken into account,
such as VLANs. In such cases, a physical port netdev can have upper
devices being members in two different bridges, thus requiring two
different 'offload_fwd_mark's to be configured on the port netdev, which
is impossible.

The main problem is that packet and netdev marking is performed at the
physical netdev level, whereas flooding occurs between bridge ports,
which are not necessarily port netdevs.

Instead, packet and netdev marking should really be done in the bridge
driver with the switch driver only telling it which packets it already
forwarded. The bridge driver will mark such packets using the mark
assigned to the ingress bridge port and will prevent the packet from
being forwarded through any bridge port sharing the same mark (i.e.
having the same parent ID).

Remove the current switchdev 'offload_fwd_mark' implementation and
instead implement the proposed method. In addition, make rocker - the
sole user of the mark - use the proposed method.

Signed-off-by: Ido Schimmel 
Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

net: bridge: remove _deliver functions and consolidate forward code

2016-07-17T02:57:38+00:00

Before this patch we had two flavors of most forwarding functions -
_forward and _deliver, the difference being that the latter are used
when the packets are locally originated. Instead of all this function
pointer passing and code duplication, we can just pass a boolean noting
that the packet was locally originated and use that to perform the
necessary checks in __br_forward. This gives a minor performance
improvement but more importantly consolidates the forwarding paths.
Also add a kernel doc comment to explain the exported br_forward()'s
arguments.

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: drop skb2/skb0 variables and use a local_rcv boolean

2016-07-17T02:57:38+00:00

Currently if the packet is going to be received locally we set skb0 or
sometimes called skb2 variables to the original skb. This can get
confusing and also we can avoid one conditional on the fast path by
simply using a boolean and passing it around. Thanks to Roopa for the
name suggestion.

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: bridge: extend MLD/IGMP query stats

2016-07-09T21:40:09+00:00

As was suggested this patch adds support for the different versions of MLD
and IGMP query types. Since the user visible structure is still in net-next
we can augment it instead of adding netlink attributes.
The distinction between the different IGMP/MLD query types is done as
suggested in Section 7.1, RFC 3376 [1] and Section 8.1, RFC 3810 [2] based
on query payload size and code for IGMP. Since all IGMP packets go through
multicast_rcv() and it uses ip_mc_check_igmp/ipv6_mc_check_mld we can be
sure that at least the ip/ipv6 header can be directly used.

[1] https://tools.ietf.org/html/rfc3376#section-7
[2] https://tools.ietf.org/html/rfc3810#section-8.1

Suggested-by: Linus Lüssing 
Signed-off-by: Nikolay Aleksandrov 
Acked-by: Stephen Hemminger 
Signed-off-by: David S. Miller

net: bridge: add support for IGMP/MLD stats and export them via netlink

2016-06-30T10:18:24+00:00

This patch adds stats support for the currently used IGMP/MLD types by the
bridge. The stats are per-port (plus one stat per-bridge) and per-direction
(RX/TX). The stats are exported via netlink via the new linkxstats API
(RTM_GETSTATS). In order to minimize the performance impact, a new option
is used to enable/disable the stats - multicast_stats_enabled, similar to
the recent vlan stats. Also in order to avoid multiple IGMP/MLD type
lookups and checks, we make use of the current "igmp" member of the bridge
private skb->cb region to record the type on Rx (both host-generated and
external packets pass by multicast_rcv()). We can do that since the igmp
member was used as a boolean and all the valid IGMP/MLD types are positive
values. The normal bridge fast-path is not affected at all, the only
affected paths are the flooding ones and since we make use of the IGMP/MLD
type, we can quickly determine if the packet should be counted using
cache-hot data (cb's igmp member). We add counters for:
* IGMP Queries
* IGMP Leaves
* IGMP v1/v2/v3 reports

* MLD Queries
* MLD Leaves
* MLD v1/v2 reports

These are invaluable when monitoring or debugging complex multicast setups
with bridges.

Signed-off-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

net: remove skb_sender_cpu_clear()

2016-03-01T22:36:47+00:00

After commit 52bd2d62ce67 ("net: better skb->sender_cpu and skb->napi_id cohabitation")
skb_sender_cpu_clear() becomes empty and can be removed.

Cc: Eric Dumazet 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

bridge: set is_local and is_static before fdb entry is added to the fdb hashtable

2015-10-30T03:13:05+00:00

Problem Description:
We can add fdbs pointing to the bridge with NULL ->dst but that has a
few race conditions because br_fdb_insert() is used which first creates
the fdb and then, after the fdb has been published/linked, sets
"is_local" to 1 and in that time frame if a packet arrives for that fdb
it may see it as non-local and either do a NULL ptr dereference in
br_forward() or attach the fdb to the port where it arrived, and later
br_fdb_insert() will make it local thus getting a wrong fdb entry.
Call chain br_handle_frame_finish() -> br_forward():
But in br_handle_frame_finish() in order to call br_forward() the dst
should not be local i.e. skb != NULL, whenever the dst is
found to be local skb is set to NULL so we can't forward it,
and here comes the problem since it's running only
with RCU when forwarding packets it can see the entry before "is_local"
is set to 1 and actually try to dereference NULL.
The main issue is that if someone sends a packet to the switch while
it's adding the entry which points to the bridge device, it may
dereference NULL ptr. This is needed now after we can add fdbs
pointing to the bridge.  This poses a problem for
br_fdb_update() as well, while someone's adding a bridge fdb, but
before it has is_local == 1, it might get moved to a port if it comes
as a source mac and then it may get its "is_local" set to 1

This patch changes fdb_create to take is_local and is_static as
arguments to set these values in the fdb entry before it is added to the
hash. Also adds null check for port in br_forward.

Fixes: 3741873b4f73 ("bridge: allow adding of fdb entries pointing to the bridge device")
Reported-by: Nikolay Aleksandrov 
Signed-off-by: Roopa Prabhu 
Reviewed-by: Nikolay Aleksandrov 
Acked-by: Stephen Hemminger 
Signed-off-by: David S. Miller

bridge: vlan: use proper rcu for the vlgrp member

2015-10-13T11:57:52+00:00

The bridge and port's vlgrp member is already used in RCU way, currently
we rely on the fact that it cannot disappear while the port exists but
that is error-prone and we might miss places with improper locking
(either RCU or RTNL must be held to walk the vlan_list). So make it
official and use RCU for vlgrp to catch offenders. Introduce proper vlgrp
accessors and use them consistently throughout the code.

Signed-off-by: Nikolay Aleksandrov 
Reviewed-by: Ido Schimmel 
Signed-off-by: David S. Miller