Commit 63233159:
    bridge: Do not unregister all PF_BRIDGE rtnl operations
introduced a bug where a removal of a single bridge from a
multi-bridge system would remove MDB netlink handlers.
The handlers should only be removed once all bridges are gone, but
since we don't keep track of the number of bridge interfaces, it's
simpler to do it when the bridge module is unloaded.  To make it
consistent, move the registration code into module initialization
code path.
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bridge fdb and link rtnl operations are registered in
core/rtnetlink.  Bridge mdb operations are registred
in bridge/mdb.  When removing bridge module, do not
unregister ALL PF_BRIDGE ops since that would remove
the ops from rtnetlink as well.  Do remove mdb ops when
bridge is destroyed.
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds a flag to each mdb entry, so that we can distinguish
permanent entries with temporary entries.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As suggested by Stephen Hemminger, this remove the temporary variable
introduced in commit eca2a43b
("bridge: fix icmpv6 endian bug and other sparse warnings")
Signed-off-by: NAng Way Chuang <wcang@sfc.wide.ad.jp>
Acked-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix the warnings reported by sparse on recent bridge multicast
changes. Mostly just rcu annotation issues but in this case
sparse found a real bug! The ICMPv6 mld2 query mrc
values is in network byte order.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implents adding/deleting mdb entries via netlink.
Currently all entries are temp, we probably need a flag to distinguish
permanent entries too.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As Stephen mentioned, we need to monitor the mdb
changes in user-space, so add notifications via netlink too.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In case of rehashing, introduce a global variable 'br_mdb_rehash_seq'
which gets increased every time when rehashing, and assign
net->dev_base_seq + br_mdb_rehash_seq to cb->seq.

In theory cb->seq could be wrapped to zero, but this is not
easy to fix, as net->dev_base_seq is not visible inside
br_mdb_rehash(). In practice, this is rare.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

V5: fix two bugs pointed out by Thomas
    remove seq check for now, mark it as TODO

V4: remove some useless #include
    some coding style fix

V3: drop debugging printk's
    update selinux perm table as well

V2: drop patch 1/2, export ifindex directly
    Redesign netlink attributes
    Improve netlink seq check
    Handle IPv6 addr as well

This patch exports bridge multicast database via netlink
message type RTM_GETMDB. Similar to fdb, but currently bridge-specific.
We may need to support modify multicast database too (RTM_{ADD,DEL}MDB).

(Thanks to Thomas for patient reviews)

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Thomas Graf <tgraf@suug.ch>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NCong Wang <amwang@redhat.com>
Acked-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

V3: make it a flag
V2: make the toggle per-port

Fast leave allows bridge to immediately stops the multicast
traffic on the port receives IGMP Leave when IGMP snooping is enabled,
no timeouts are observed.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NCong Wang <amwang@redhat.com>

V2: make the toggle per-port

Fast leave allows bridge to immediately stops the multicast
traffic on the port receives IGMP Leave when IGMP snooping is enabled,
no timeouts are observed.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NCong Wang <amwang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The hash size is doubled when it needs to grow and compared against
hash_max. The >= comparison will limit the hash table size to half
of what is expected i.e. the default 512 hash_max will not allow
the hash table to grow larger than 256.

Also print the hash table limit instead of the desirable size when
the limit is reached.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

mld->mld_maxdelay is net endian, so we should use ntohs, not htons

CC: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The padding destination or hop-by-hop option is called Pad1 and not Pad0.

See RFC2460 (4.2) or the IANA ipv6-parameters registry:
http://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xmlSigned-off-by: NEldad Zack <eldad@fogrefinery.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Unfortunately it seems that I didn't properly test the case of
an expired external querier in the recent multicast bridge series.

The setup of the timer in that case is completely broken and leads
to a NULL-pointer dereference.  This patch fixes it.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid 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: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As it stands when we discover that a real querier (one that queries
with a non-zero source address) we stop querying.  However, even
after said querier has fallen off the edge of the earth, we will
never restart querying (unless the bridge itself is restarted).

This patch fixes this by kicking our own querier into gear when
the timer for other queriers expire.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the helper br_multicast_start_querier so that
the code which starts the queriers in br_multicast_toggle can
be reused elsewhere.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use of "unsigned int" is preferred to bare "unsigned" in net tree.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid 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: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

otherwise source IPv6 address of ICMPV6_MGM_QUERY packet
might be random junk if IPv6 is disabled on interface or
link-local address is not yet ready (DAD).
Signed-off-by: NUlrich Weber <ulrich.weber@sophos.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While parsing through IPv6 extension headers, fragment headers are
skipped making them invisible to the caller.  This reports the
fragment offset of the last header in order to make it possible to
determine whether the packet is fragmented and, if so whether it is
a first or last fragment.
Signed-off-by: NJesse Gross <jesse@nicira.com>

C assignment can handle struct in6_addr copying.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Bridge multicast snooping of ICMPv6 would incorrectly report a checksum problem
when used with Ethernet devices like sky2 that use CHECKSUM_COMPLETE.
When bytes are removed from skb, the computed checksum needs to be adjusted.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Tested-by: NMartin Volf <martin.volf.42@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

multicast_lock is taken in softirq context, so we should use
spin_lock_bh() in userspace.

call-chain in softirq context:
run_timer_softirq()
	br_multicast_query_expired()

call-chain in userspace:
sysfs_write_file()
	store_multicast_snooping()
		br_multicast_toggle()
Signed-off-by: NAndrew Vagin <avagin@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

br_multicast_ipv6_rcv() can call pskb_trim_rcsum() and therefore skb
head can be reallocated.

Cache icmp6_type field instead of dereferencing twice the struct
icmp6hdr pointer.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Checksum of ICMPv6 is not properly computed because the pseudo header is not used.
Thus, the MLD packet gets dropped by the bridge.
Signed-off-by: NZheng Yan <zheng.z.yan@intel.com>
Reported-by: NAng Way Chuang <wcang@sfc.wide.ad.jp>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The bridge currently floods packets to groups that we have never
seen before to all ports.  This is not required by RFC4541 and
in fact it is not desirable in environment where traffic to
unregistered group is always present.

This patch changes the behaviour so that we only send traffic
to unregistered groups to ports marked as routers.

The user can always force flooding behaviour to any given port
by marking it as a router.

Note that this change does not apply to traffic to 224.0.0.X
as traffic to those groups must always be flooded to all ports.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Upon reception of a MGM report packet the kernel sets the mrouters_only flag
in a skb that is a clone of the original skb, which means that the bridge
loses track of MGM packets (cb buffers are tied to a specific skb and not
shared) and it ends up forwading join requests to the bridge interface.

This can cause unexpected membership timeouts and intermitent/permanent loss
of connectivity as described in RFC 4541 [2.1.1. IGMP Forwarding Rules]:

    A snooping switch should forward IGMP Membership Reports only to
    those ports where multicast routers are attached.
    [...]
    Sending membership reports to other hosts can result, for IGMPv1
    and IGMPv2, in unintentionally preventing a host from joining a
    specific multicast group.
Signed-off-by: NFernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: NDavid S. Miller <davem@conan.davemloft.net>

Upon reception of a IGMP/IGMPv2 membership report the kernel sets the
mrouters_only flag in a skb that may be a clone of the original skb, which
means that sometimes the bridge loses track of membership report packets (cb
buffers are tied to a specific skb and not shared) and it ends up forwading
join requests to the bridge interface.

This can cause unexpected membership timeouts and intermitent/permanent loss
of connectivity as described in RFC 4541 [2.1.1. IGMP Forwarding Rules]:

    A snooping switch should forward IGMP Membership Reports only to
    those ports where multicast routers are attached.
    [...]
    Sending membership reports to other hosts can result, for IGMPv1
    and IGMPv2, in unintentionally preventing a host from joining a
    specific multicast group.
Signed-off-by: NFernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Tested-by: NHayato Kakuta <kakuta.hayato@oss.ntt.co.jp>
Signed-off-by: NDavid S. Miller <davem@conan.davemloft.net>

Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

"len = ntohs(ip6h->payload_len)" does not include the length of the ipv6
header itself, which the rest of this function assumes, though.

This leads to a length check less restrictive as it should be in the
following line for one thing. For another, it very likely leads to an
integer underrun when substracting the offset and therefore to a very
high new value of 'len' due to its unsignedness. This will ultimately
lead to the pskb_trim_rcsum() practically never being called, even in
the cases where it should.
Signed-off-by: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ipv6_dev_get_saddr() is currently called with an uninitialized
destination address. Although in tests it usually seemed to nevertheless
always fetch the right source address, there seems to be a possible race
condition.

Therefore this commit changes this, first setting the destination
address and only after that fetching the source address.
Reported-by: NJan Beulich <JBeulich@novell.com>
Signed-off-by: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid 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: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid 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: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The nsrcs number is 2 Byte wide, therefore we need to call ntohs()
before using it.
Signed-off-by: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid 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: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid 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: NLinus Lüssing <linus.luessing@web.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>