slave_enable_netpoll() and __netpoll_setup() may be called
with read_lock() held, so should use GFP_ATOMIC to allocate
memory. Eric suggested to pass gfp flags to __netpoll_setup().
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This ensures that bridges created with brctl(8) or ioctl(2) directly
also carry IFLA_LINKINFO when dumped over netlink. This also allows
to create a bridge with ioctl(2) and delete it with RTM_DELLINK.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds two new flags NTF_MASTER and NTF_SELF that can
now be used to specify where PF_BRIDGE netlink commands should
be sent. NTF_MASTER sends the commands to the 'dev->master'
device for parsing. Typically this will be the linux net/bridge,
or open-vswitch devices. Also without any flags set the command
will be handled by the master device as well so that current user
space tools continue to work as expected.
The NTF_SELF flag will push the PF_BRIDGE commands to the
device. In the basic example below the commands are then parsed
and programmed in the embedded bridge.
Note if both NTF_SELF and NTF_MASTER bits are set then the
command will be sent to both 'dev->master' and 'dev' this allows
user space to easily keep the embedded bridge and software bridge
in sync.
There is a slight complication in the case with both flags set
when an error occurs. To resolve this the rtnl handler clears
the NTF_ flag in the netlink ack to indicate which sets completed
successfully. The add/del handlers will abort as soon as any
error occurs.
To support this new net device ops were added to call into
the device and the existing bridging code was refactored
to use these. There should be no required changes in user space
to support the current bridge behavior.
A basic setup with a SR-IOV enabled NIC looks like this,
veth0 veth2
| |
------------
| bridge0 | <---- software bridging
------------
/
/
ethx.y ethx
VF PF
\ \ <---- propagate FDB entries to HW
\ \
--------------------
| Embedded Bridge | <---- hardware offloaded switching
--------------------
In this case the embedded bridge must be managed to allow 'veth0'
to communicate with 'ethx.y' correctly. At present drivers managing
the embedded bridge either send frames onto the network which
then get dropped by the switch OR the embedded bridge will flood
these frames. With this patch we have a mechanism to manage the
embedded bridge correctly from user space. This example is specific
to SR-IOV but replacing the VF with another PF or dropping this
into the DSA framework generates similar management issues.
Examples session using the 'br'[1] tool to add, dump and then
delete a mac address with a new "embedded" option and enabled
ixgbe driver:
# br fdb add 22:35:19:ac:60:59 dev eth3
# br fdb
port mac addr flags
veth0 22:35:19:ac:60:58 static
veth0 9a:5f:81:f7:f6:ec local
eth3 00:1b:21:55:23:59 local
eth3 22:35:19:ac:60:59 static
veth0 22:35:19:ac:60:57 static
#br fdb add 22:35:19:ac:60:59 embedded dev eth3
#br fdb
port mac addr flags
veth0 22:35:19:ac:60:58 static
veth0 9a:5f:81:f7:f6:ec local
eth3 00:1b:21:55:23:59 local
eth3 22:35:19:ac:60:59 static
veth0 22:35:19:ac:60:57 static
eth3 22:35:19:ac:60:59 local embedded
#br fdb del 22:35:19:ac:60:59 embedded dev eth3
I added a couple lines to 'br' to set the flags correctly is all. It
is my opinion that the merit of this patch is now embedded and SW
bridges can both be modeled correctly in user space using very nearly
the same message passing.
[1] 'br' tool was published as an RFC here and will be renamed 'bridge'
http://patchwork.ozlabs.org/patch/117664/
Thanks to Jamal Hadi Salim, Stephen Hemminger and Ben Hutchings for
valuable feedback, suggestions, and review.
v2: fixed api descriptions and error case with both NTF_SELF and
NTF_MASTER set plus updated patch description.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sending general queries was implemented as an optimisation to speed
up convergence on start-up. In order to prevent interference with
multicast routers a zero source address has to be used.
Unfortunately these packets appear to cause some multicast-aware
switches to misbehave, e.g., by disrupting multicast packets to us.
Since the multicast snooping feature still functions without sending
our own queries, this patch will change the default to not send
queries.
For those that need queries in order to speed up convergence on start-up,
a toggle is provided to restore the previous behaviour.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
As it stands the bridge IGMP snooping system will respond to
group leave messages with queries for remaining membership.
This is both unnecessary and undesirable. First of all any
multicast routers present should be doing this rather than us.
What's more the queries that we send may end up upsetting other
multicast snooping swithces in the system that are buggy.
In fact, we can simply remove the code that send these queries
because the existing membership expiry mechanism doesn't rely
on them anyway.
So this patch simply removes all code associated with group
queries in response to group leave messages.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use IS_ENABLED(CONFIG_FOO)
instead of defined(CONFIG_FOO) || defined (CONFIG_FOO_MODULE)
Signed-off-by: Igor Maravić <igorm@etf.rs>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If user has configured a MAC address that is not one of the existing
ports of the bridge, then we need to add a special entry in the forwarding
table. This forwarding table entry has no outgoing port so it has to be
treated a little differently. The special entry is reported by the netlink
interface with ifindex of bridge, but ignored by the old interface since there
is no usable way to put it in the ABI.
Reported-by: Koki Sanagi <sanagi.koki@jp.fujitsu.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
v2: add couple missing conversions in drivers
split unexporting netdev_fix_features()
implemented %pNF
convert sock::sk_route_(no?)caps
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Need to cleanup bridge device timers and ports when being bridge
device is being removed via netlink.
This fixes the problem of observed when doing:
ip link add br0 type bridge
ip link set dev eth1 master br0
ip link set br0 up
ip link del br0
which would cause br0 to hang in unregister_netdev because
of leftover reference count.
Reported-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Sridhar Samudrala <sri@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is based on an earlier patch by Nick Carter with comments
by David Lamparter but with some refinements. Thanks for their patience
this is a confusing area with overlap of standards, user requirements,
and compatibility with earlier releases.
It adds a new sysfs attribute
/sys/class/net/brX/bridge/group_fwd_mask
that controls forwarding of frames with address of: 01-80-C2-00-00-0X
The default setting has no forwarding to retain compatibility.
One change from earlier releases is that forwarding of group
addresses is not dependent on STP being enabled or disabled. This
choice was made based on interpretation of tie 802.1 standards.
I expect complaints will arise because of this, but better to follow
the standard than continue acting incorrectly by default.
The filtering mask is writeable, but only values that don't forward
known control frames are allowed. It intentionally blocks attempts
to filter control protocols. For example: writing a 8 allows
forwarding 802.1X PAE addresses which is the most common request.
Reported-by: David Lamparter <equinox@diac24.net>
Original-patch-by: Nick Carter <ncarter100@gmail.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Tested-by: Benjamin Poirier <benjamin.poirier@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A bridge topology with three systems:
+------+ +------+
| A(2) |--| B(1) |
+------+ +------+
\ /
+------+
| C(3) |
+------+
What is supposed to happen:
* bridge with the lowest ID is elected root (for example: B)
* C detects that A->C is higher cost path and puts in blocking state
What happens. Bridge with lowest id (B) is elected correctly as
root and things start out fine initially. But then config BPDU
doesn't get transmitted from A -> C. Because of that
the link from A-C is transistioned to the forwarding state.
The root cause of this is that the configuration messages
is generated with bogus message age, and dropped before
sending.
In the standardmessage_age is supposed to be:
the time since the generation of the Configuration BPDU by
the Root that instigated the generation of this Configuration BPDU.
Reimplement this by recording the timestamp (age + jiffies) when
recording config information. The old code incorrectly used the time
elapsed on the ageing timer which was incorrect.
See also:
https://bugzilla.vyatta.com/show_bug.cgi?id=7164
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Note: netdev_update_features() needs only rtnl_lock as br->port_list
is only changed while holding it.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Apply restrictions on STP parameters based 802.1D 1998 standard.
* Fixes missing locking in set path cost ioctl
* Uses common code for both ioctl and sysfs
This is based on an earlier patch Sasikanth V but with overhaul.
Note:
1. It does NOT enforce the restriction on the relationship max_age and
forward delay or hello time because in existing implementation these are
set as independant operations.
2. If STP is disabled, there is no restriction on forward delay
3. No restriction on holding time because users use Linux code to act
as hub or be sticky.
4. Although standard allow 0-255, Linux only allows 0-63 for port priority
because more bits are reserved for port number.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use RTM_NEWNEIGH and RTM_DELNEIGH to allow updating of entries
in bridge forwarding table. This allows manipulating static entries
which is not possible with existing tools.
Example (using bridge extensions to iproute2)
# br fdb add 00:02:03:04:05:06 dev eth0
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows applications to query and monitor bridge forwarding
table in the same method used for neighbor table. The forward table
entries are returned in same structure format as used by the ioctl.
If more information is desired in future, the netlink method is
extensible.
Example (using bridge extensions to iproute2)
# br monitor
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adds tracking the last used time in forwarding table.
Rename ageing_timer to updated to better describe it.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The mac address of the bridge device may be changed when a new interface
is added to the bridge. If this happens, then the bridge needs to call
the network notifiers to tickle any other systems that care. Since bridge
can be a module, this also means exporting the notifier function.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows rx_handlers to better signalize what to do next to
it's caller. That makes skb->deliver_no_wcard no longer needed.
kernel-doc for rx_handler_result is taken from Nicolas' patch.
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Reviewed-by: Nicolas de Pesloüan <nicolas.2p.debian@free.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
As it turns out we never need to walk through the list of multicast
groups subscribed by the bridge interface itself (the only time we'd
want to do that is when we shut down the bridge, in which case we
simply walk through all multicast groups), we don't really need to
keep an hlist for mp->mglist.
This means that we can replace it with just a single bit to indicate
whether the bridge interface is subscribed to a group.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.
Occurences found by `grep -r` on net/, drivers/net, include/
[ Move features and vlan_features next to each other in
struct netdev, as per Eric Dumazet's suggestion -DaveM ]
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
br_port_get() renamed to br_port_get_rtnl() to make clear RTNL is held.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The macro br_port_exists() is not enough protection when only
RCU is being used. There is a tiny race where other CPU has cleared port
handler hook, but is bridge port flag might still be set.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add modern __rcu annotatations to bridge multicast table.
Use newer hlist macros to avoid direct access to hlist internals.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Support more fine grained control of bridge netfilter iptables invocation
by adding seperate brnf_call_*tables parameters for each device using the
sysfs interface. Packets are passed to layer 3 netfilter when either the
global parameter or the per bridge parameter is enabled.
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Use u64_stats_sync infrastructure to provide 64bit rx/tx
counters even on 32bit hosts.
It is safe to use a single u64_stats_sync for rx and tx,
because BH is disabled on both, and we use per_cpu data.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The version of br_netpoll_send_skb used when netpoll is off is
missing a const thus causing a warning.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Register net_bridge_port pointer as rx_handler data pointer. As br_port is
removed from struct net_device, another netdev priv_flag is added to indicate
the device serves as a bridge port. Also rcuized pointers are now correctly
dereferenced in br_fdb.c and in netfilter parts.
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are multiple problems with the newly added netpoll support:
1) Use-after-free on each netpoll packet.
2) Invoking unsafe code on netpoll/IRQ path.
3) Breaks when netpoll is enabled on the underlying device.
This patch fixes all of these problems. In particular, we now
allocate proper netpoll structures for each underlying device.
We only allow netpoll to be enabled on the bridge when all the
devices underneath it support netpoll. Once it is enabled, we
do not allow non-netpoll devices to join the bridge (until netpoll
is disabled again).
This allows us to do away with the npinfo juggling that caused
problem number 1.
Incidentally this patch fixes number 2 by bypassing unsafe code
such as multicast snooping and netfilter.
Reported-by: Qianfeng Zhang <frzhang@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
What this patch does is it removes two receive frame hooks (for bridge and for
macvlan) from __netif_receive_skb. These are replaced them with a single
hook for both. It only supports one hook per device because it makes no
sense to do bridging and macvlan on the same device.
Then a network driver (of virtual netdev like macvlan or bridge) can register
an rx_handler for needed net device.
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Links for each port are created in sysfs using the device
name, but this could be changed after being added to the
bridge.
As well as being unable to remove interfaces after this
occurs (because userspace tools don't recognise the new
name, and the kernel won't recognise the old name), adding
another interface with the old name to the bridge will
cause an error trying to create the sysfs link.
This fixes the problem by listening for NETDEV_CHANGENAME
notifications and renaming the link.
https://bugzilla.kernel.org/show_bug.cgi?id=12743
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use one set of macro's for all bridge messages.
Note: can't use netdev_XXX macro's because bridge is purely
virtual and has no device parent.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move code around so that the ifdef for NETPOLL_CONTROLLER don't have to
show up in main code path. The control functions should be in helpers
that are only compiled if needed.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on the previous patch, make bridge support netpoll by:
1) implement the 2 methods to support netpoll for bridge;
2) modify netpoll during forwarding packets via bridge;
3) disable netpoll support of bridge when a netpoll-unabled device
is added to bridge;
4) enable netpoll support when all underlying devices support netpoll.
Cc: David Miller <davem@davemloft.net>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: WANG Cong <amwang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce struct br_ip{} to store ip address and protocol
and make functions more generic so that we can support
both IPv4 and IPv6 with less pain.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Sparse can help us find endianness bugs, but we need to make some
cleanups to be able to more easily spot real bugs.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The shared packet statistics are a potential source of slow down
on bridged traffic. Convert to per-cpu array, but only keep those
statistics which change per-packet.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Without CONFIG_BRIDGE_IGMP_SNOOPING,
BR_INPUT_SKB_CB(skb)->mrouters_only is not appropriately
initialized, so we can see garbage.
A clear option to fix this is to set it even without that
config, but we cannot optimize out the branch.
Let's introduce a macro that returns value of mrouters_only
and let it return 0 without CONFIG_BRIDGE_IGMP_SNOOPING.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
From: Michael Braun <michael-dev@fami-braun.de>
bridge: Fix br_forward crash in promiscuous mode
It's a linux-next kernel from 2010-03-12 on an x86 system and it
OOPs in the bridge module in br_pass_frame_up (called by
br_handle_frame_finish) because brdev cannot be dereferenced (its set to
a non-null value).
Adding some BUG_ON statements revealed that
BR_INPUT_SKB_CB(skb)->brdev == br-dev
(as set in br_handle_frame_finish first)
only holds until br_forward is called.
The next call to br_pass_frame_up then fails.
Digging deeper it seems that br_forward either frees the skb or passes
it to NF_HOOK which will in turn take care of freeing the skb. The
same is holds for br_pass_frame_ip. So it seems as if two independent
skb allocations are required. As far as I can see, commit
b33084be19 ("bridge: Avoid unnecessary
clone on forward path") removed skb duplication and so likely causes
this crash. This crash does not happen on 2.6.33.
I've therefore modified br_forward the same way br_flood has been
modified so that the skb is not freed if skb0 is going to be used
and I can confirm that the attached patch resolves the issue for me.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Constify struct sysfs_ops.
This is part of the ops structure constification
effort started by Arjan van de Ven et al.
Benefits of this constification:
* prevents modification of data that is shared
(referenced) by many other structure instances
at runtime
* detects/prevents accidental (but not intentional)
modification attempts on archs that enforce
read-only kernel data at runtime
* potentially better optimized code as the compiler
can assume that the const data cannot be changed
* the compiler/linker move const data into .rodata
and therefore exclude them from false sharing
Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix the following build error when IGMP_SNOOPING is not enabled.
In file included from net/bridge/br.c:24:
net/bridge/br_private.h: In function 'br_multicast_is_router':
net/bridge/br_private.h:361: error: 'struct net_bridge' has no member named 'multicast_router'
net/bridge/br_private.h:362: error: 'struct net_bridge' has no member named 'multicast_router'
net/bridge/br_private.h:363: error: 'struct net_bridge' has no member named 'multicast_router_timer'
Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows the user to control the hash elasticity/max
parameters. The elasticity setting does not take effect until
the next new multicast group is added. At which point it is
checked and if after rehashing it still can't be satisfied then
snooping will be disabled.
The max setting on the other hand takes effect immediately. It
must be a power of two and cannot be set to a value less than the
current number of multicast group entries. This is the only way
to shrink the multicast hash.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows the user to disable IGMP snooping completely
through a sysfs toggle. It also allows the user to reenable
snooping when it has been automatically disabled due to hash
collisions. If the collisions have not been resolved however
the system will refuse to reenable snooping.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows the user to forcibly enable/disable ports as
having multicast routers attached. A port with a multicast router
will receive all multicast traffic.
The value 0 disables it completely. The default is 1 which lets
the system automatically detect the presence of routers (currently
this is limited to picking up queries), and 2 means that the port
will always receive all multicast traffic.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds code to perform selective multicast forwarding.
We forward multicast traffic to a set of ports plus all multicast
router ports. In order to avoid duplications among these two
sets of ports, we order all ports by the numeric value of their
pointers. The two lists are then walked in lock-step to eliminate
duplicates.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds the core functionality of IGMP snooping support
without actually hooking it up. So this patch should be a no-op
as far as the bridge's external behaviour is concerned.
All the new code and data is controlled by the Kconfig option
BRIDGE_IGMP_SNOOPING. A run-time toggle is also available.
The multicast switching is done using an hash table that is
lockless on the read-side through RCU. On the write-side the
new multicast_lock is used for all operations. The hash table
supports dynamic growth/rehashing.
The hash table will be rehashed if any chain length exceeds a
preset limit. If rehashing does not reduce the maximum chain
length then snooping will be disabled.
These features may be added in future (in no particular order):
* IGMPv3 source support
* Non-querier router detection
* IPv6
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
