linux.git/net/bridge, branch v2.6.38

net: bridge builtin vs. ipv6 modular

2011-03-10T21:45:57+00:00

When configs BRIDGE=y and IPV6=m, this build error occurs:

br_multicast.c:(.text+0xa3341): undefined reference to `ipv6_dev_get_saddr'

BRIDGE_IGMP_SNOOPING is boolean; if it were tristate, then adding
	depends on IPV6 || IPV6=n
to BRIDGE_IGMP_SNOOPING would be a good fix.  As it is currently,
making BRIDGE depend on the IPV6 config works.

Reported-by: Patrick Schaaf 
Signed-off-by: Randy Dunlap 
Signed-off-by: David S. Miller

bridge: Use IPv6 link-local address for multicast listener queries

2011-02-22T18:07:29+00:00

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 
Signed-off-by: David S. Miller

bridge: Fix MLD queries' ethernet source address

2011-02-22T18:07:28+00:00

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 
Signed-off-by: David S. Miller

bridge: Allow mcast snooping for transient link local addresses too

2011-02-22T18:07:28+00:00

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 
Signed-off-by: David S. Miller

bridge: Add missing ntohs()s for MLDv2 report parsing

2011-02-22T18:07:27+00:00

The nsrcs number is 2 Byte wide, therefore we need to call ntohs()
before using it.

Signed-off-by: Linus Lüssing 
Signed-off-by: David S. Miller

bridge: Fix IPv6 multicast snooping by correcting offset in MLDv2 report

2011-02-22T18:07:26+00:00

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 
Signed-off-by: David S. Miller

bridge: Fix IPv6 multicast snooping by storing correct protocol type

2011-02-22T18:07:26+00:00

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 
Signed-off-by: David S. Miller

bridge: Replace mp->mglist hlist with a bool

2011-02-12T09:05:42+00:00

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 
Signed-off-by: David S. Miller

bridge: Fix timer typo that may render snooping less effective

2011-02-12T05:59:37+00:00

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 
Signed-off-by: David S. Miller

bridge: Fix mglist corruption that leads to memory corruption

2011-02-12T05:59:37+00:00

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 
Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller