Currently the bridge multicast snooping feature periodically issues
IPv6 general multicast listener queries to sense the absence of a
listener.
For this, it uses :: as its source address - however RFC 2710 requires:
"To be valid, the Query message MUST come from a link-local IPv6 Source
Address". Current Linux kernel versions seem to follow this requirement
and ignore our bogus MLD queries.
With this commit a link local address from the bridge interface is being
used to issue the MLD query, resulting in other Linux devices which are
multicast listeners in the network to respond with a MLD response (which
was not the case before).
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Map the IPv6 header's destination multicast address to an ethernet
source address instead of the MLD queries multicast address.
For instance for a general MLD query (multicast address in the MLD query
set to ::), this would wrongly be mapped to 33:33:00:00:00:00, although
an MLD queries destination MAC should always be 33:33:00:00:00:01 which
matches the IPv6 header's multicast destination ff02::1.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the multicast bridge snooping support is not active for
link local multicast. I assume this has been done to leave
important multicast data untouched, like IPv6 Neighborhood Discovery.
In larger, bridged, local networks it could however be desirable to
optimize for instance local multicast audio/video streaming too.
With the transient flag in IPv6 multicast addresses we have an easy
way to optimize such multimedia traffic without tempering with the
high priority multicast data from well-known addresses.
This patch alters the multicast bridge snooping for IPv6, to take
effect for transient multicast addresses instead of non-link-local
addresses.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The nsrcs number is 2 Byte wide, therefore we need to call ntohs()
before using it.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
We actually want a pointer to the grec_nsrcr and not the following
field. Otherwise we can get very high values for *nsrcs as the first two
bytes of the IPv6 multicast address are being used instead, leading to
a failing pskb_may_pull() which results in MLDv2 reports not being
parsed.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
The protocol type for IPv6 entries in the hash table for multicast
bridge snooping is falsely set to ETH_P_IP, marking it as an IPv4
address, instead of setting it to ETH_P_IPV6, which results in negative
look-ups in the hash table later.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
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>
In a couple of spots where we are supposed to modify the port
group timer (p->timer) we instead modify the bridge interface
group timer (mp->timer).
The effect of this is mostly harmless. However, it can cause
port subscriptions to be longer than they should be, thus making
snooping less effective.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The list mp->mglist is used to indicate whether a multicast group
is active on the bridge interface itself as opposed to one of the
constituent interfaces in the bridge.
Unfortunately the operation that adds the mp->mglist node to the
list neglected to check whether it has already been added. This
leads to list corruption in the form of nodes pointing to itself.
Normally this would be quite obvious as it would cause an infinite
loop when walking the list. However, as this list is never actually
walked (which means that we don't really need it, I'll get rid of
it in a subsequent patch), this instead is hidden until we perform
a delete operation on the affected nodes.
As the same node may now be pointed to by more than one node, the
delete operations can then cause modification of freed memory.
This was observed in practice to cause corruption in 512-byte slabs,
most commonly leading to crashes in jbd2.
Thanks to Josef Bacik for pointing me in the right direction.
Reported-by: Ian Page Hands <ihands@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes a missing ntohs() for bridge IPv6 multicast snooping.
Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
If br_multicast_new_group returns NULL, we would return 0 (no error) to
the caller of br_multicast_add_group, which is not what we want. Instead
br_multicast_new_group should return ERR_PTR(-ENOMEM) in this case.
Also propagate the error number returned by br_mdb_rehash properly.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
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>
Currently you cannot disable multicast snooping while a device is
down. There is no good reason for this restriction and this patch
removes it.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv6_skip_exthdr() can return error code that is below zero.
'offset' is unsigned, so it makes no sense.
ipv6_skip_exthdr() returns 'int' so we can painlessly change type of
offset to int.
Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On Tue, Jul 06, 2010 at 08:48:35AM +0800, Herbert Xu wrote:
>
> bridge: Restore NULL check in br_mdb_ip_get
Resend with proper attribution.
bridge: Restore NULL check in br_mdb_ip_get
Somewhere along the line the NULL check in br_mdb_ip_get went
AWOL, causing crashes when we receive an IGMP packet with no
multicast table allocated.
This patch restores it and ensures all br_mdb_*_get functions
use it.
Reported-by: Frank Arnold <frank.arnold@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Thanks,
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>
The recently introduced bridge mulitcast port group list was only
partially using RCU correctly. It was missing rcu_dereference()
and missing the necessary barrier on deletion.
The code should have used one of the standard list methods (list or hlist)
instead of open coding a RCU based link list.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
By coding slightly differently, there are only two cases
to deal with: add at head and add after previous entry.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit ff65e8275f.
As explained by Stephen Hemminger, the traversal doesn't require
RCU handling as we hold a lock.
The list addition et al. calls, on the other hand, do.
Signed-off-by: David S. Miller <davem@davemloft.net>
I prefer that the hlist be only accessed through the hlist macro
objects. Explicit twiddling of links (especially with RCU) exposes
the code to future bugs.
Compile tested only.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based upon a report from Stephen Rothwell:
--------------------
net/bridge/br_multicast.c: In function 'br_ip6_multicast_alloc_query':
net/bridge/br_multicast.c:469: error: implicit declaration of function 'csum_ipv6_magic'
Introduced by commit 08b202b672 ("bridge
br_multicast: IPv6 MLD support") from the net tree.
csum_ipv6_magic is declared in net/ip6_checksum.h ...
--------------------
Signed-off-by: David S. Miller <davem@davemloft.net>
Even with commit 32dec5dd02 ("bridge
br_multicast: Don't refer to BR_INPUT_SKB_CB(skb)->mrouters_only
without IGMP snooping."), BR_INPUT_SKB_CB(skb)->mrouters_only is
not appropriately initialized if IGMP/MLD snooping support is
compiled and disabled, so we can see garbage.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
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>
grec_nsrcs is in network order, we should convert to host horder in
br_multicast_igmp3_report()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The IGMP3 report parsing is looking at the wrong address for
group records. This patch fixes it.
Reported-by: Banyeer <banyeer@yahoo.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The first argument to NF_HOOK* is an nfproto since quite some time.
Commit v2.6.27-2457-gfdc9314 was the first to practically start using
the new names. Do that now for the remaining NF_HOOK calls.
The semantic patch used was:
// <smpl>
@@
@@
(NF_HOOK
|NF_HOOK_THRESH
)(
-PF_BRIDGE,
+NFPROTO_BRIDGE,
...)
@@
@@
NF_HOOK(
-PF_INET6,
+NFPROTO_IPV6,
...)
@@
@@
NF_HOOK(
-PF_INET,
+NFPROTO_IPV4,
...)
// </smpl>
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
We never actually use iph again so this assignment can be removed.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since all callers of br_mdb_ip_get need to check whether the
hash table is NULL, this patch moves the check into the function.
This fixes the two callers (query/leave handler) that didn't
check it.
Reported-by: Michael Braun <michael-dev@fami-braun.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Thanks to Paul McKenny for pointing out that it is incorrect to use
synchronize_rcu_bh to ensure that pending callbacks have completed.
Instead we should use rcu_barrier_bh.
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
As Paul McKenney correctly pointed out, __br_mdb_ip_get needs
to use the RCU list walking primitive in order to work correctly
on platforms where data-dependency ordering is not guaranteed.
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
We dereference "port" on the lines immediately before and immediately
after the test so port should hopefully never be null here.
Signed-off-by: Dan Carpenter <error27@gmail.com>
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 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 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>
