Add a global knob that controls if vlan multicast snooping is enabled.
The proper contexts (vlan or bridge-wide) will be chosen based on the knob
when processing packets and changing bridge device state. Note that
vlans have their individual mcast snooping enabled by default, but this
knob is needed to turn on bridge vlan snooping. It is disabled by
default. To enable the knob vlan filtering must also be enabled, it
doesn't make sense to have vlan mcast snooping without vlan filtering
since that would lead to inconsistencies. Disabling vlan filtering will
also automatically disable vlan mcast snooping.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add helpers to enable/disable vlan multicast based on its flags, we need
two flags because we need to know if the vlan has multicast enabled
globally (user-controlled) and if it has it enabled on the specific device
(bridge or port). The new private vlan flags are:
 - BR_VLFLAG_MCAST_ENABLED: locally enabled multicast on the device, used
   when removing a vlan, toggling vlan mcast snooping and controlling
   single vlan (kernel-controlled, valid under RTNL and multicast_lock)
 - BR_VLFLAG_GLOBAL_MCAST_ENABLED: globally enabled multicast for the
   vlan, used to control the bridge-wide vlan mcast snooping for a
   single vlan (user-controlled, can be checked under any context)

Bridge vlan contexts are created with multicast snooping enabled by
default to be in line with the current bridge snooping defaults. In
order to actually activate per vlan snooping and context usage a
bridge-wide knob will be added later which will default to disabled.
If that knob is enabled then automatically all vlan snooping will be
enabled. All vlan contexts are initialized with the current bridge
multicast context defaults.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add global and per-port vlan multicast context, only initialized but
still not used. No functional changes intended.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass multicast context pointers to multicast functions instead of bridge/port.
This would make it easier later to switch these contexts to their per-vlan
versions. The patch is basically search and replace, no functional changes.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Factor out the bridge's global multicast context into a separate
structure which will later be used for per-vlan global context.
No functional changes intended.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Factor out the port's multicast context into a separate structure which
will later be shared for per-port,vlan context. No functional changes
intended. We need the structure even if bridge multicast is not defined
to pass down as pointer to forwarding functions.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an MRD advertisement is received on a bridge port with multicast
snooping enabled, we mark it as a router port automatically, that
includes adding that port to the router port list. The multicast lock
protects that list, but it is not acquired in the MRD advertisement case
leading to a race condition, we need to take it to fix the race.

Cc: stable@vger.kernel.org
Cc: linus.luessing@c0d3.blue
Fixes: 4b3087c7 ("bridge: Snoop Multicast Router Advertisements")
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a PIM hello packet is received on a bridge port with multicast
snooping enabled, we mark it as a router port automatically, that
includes adding that port the router port list. The multicast lock
protects that list, but it is not acquired in the PIM message case
leading to a race condition, we need to take it to fix the race.

Cc: stable@vger.kernel.org
Fixes: 91b02d3d ("bridge: mcast: add router port on PIM hello message")
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The br_ip6_multicast_add_router() prototype is defined only when
CONFIG_IPV6 is enabled, but the function is always referenced, so there
is this build error with CONFIG_IPV6 not defined:

net/bridge/br_multicast.c: In function ‘__br_multicast_enable_port’:
net/bridge/br_multicast.c:1743:3: error: implicit declaration of function ‘br_ip6_multicast_add_router’; did you mean ‘br_ip4_multicast_add_router’? [-Werror=implicit-function-declaration]
 1743 |   br_ip6_multicast_add_router(br, port);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~
      |   br_ip4_multicast_add_router
net/bridge/br_multicast.c: At top level:
net/bridge/br_multicast.c:2804:13: warning: conflicting types for ‘br_ip6_multicast_add_router’
 2804 | static void br_ip6_multicast_add_router(struct net_bridge *br,
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~
net/bridge/br_multicast.c:2804:13: error: static declaration of ‘br_ip6_multicast_add_router’ follows non-static declaration
net/bridge/br_multicast.c:1743:3: note: previous implicit declaration of ‘br_ip6_multicast_add_router’ was here
 1743 |   br_ip6_multicast_add_router(br, port);
      |   ^~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix this build error by moving the definition out of the #ifdef.

Fixes: a3c02e76 ("net: bridge: mcast: split multicast router state for IPv4 and IPv6")
Signed-off-by: NMatteo Croce <mcroce@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To properly support routable multicast addresses in batman-adv in a
group-aware way, a batman-adv node needs to know if it serves multicast
routers.

This adds a function to the bridge to export this so that batman-adv
can then make full use of the Multicast Router Discovery capability of
the bridge.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A multicast router for IPv4 does not imply that the same host also is a
multicast router for IPv6 and vice versa.

To reduce multicast traffic when a host is only a multicast router for
one of these two protocol families, keep router state for IPv4 and IPv6
separately. Similar to how querier state is kept separately.

For backwards compatibility for netlink and switchdev notifications
these two will still only notify if a port switched from either no
IPv4/IPv6 multicast router to any IPv4/IPv6 multicast router or the
other way round. However a full netlink MDB router dump will now also
include a multicast router timeout for both IPv4 and IPv6.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for the upcoming split of multicast router state into
their IPv4 and IPv6 variants split router port deletion and notification
into two functions. When we disable a port for instance later we want to
only send one notification to switchdev and netlink for compatibility
and want to avoid sending one for IPv4 and one for IPv6. For that the
split is needed.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for the upcoming split of multicast router state into
their IPv4 and IPv6 variants move the protocol specific router list
and timer access to ip4 wrapper functions.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for the upcoming split of multicast router state into
their IPv4 and IPv6 variants move the protocol specific timer access to
an ip4 wrapper function.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for the upcoming split of multicast router state into
their IPv4 and IPv6 variants make br_multicast_is_router() protocol
family aware.

Note that for now br_ip6_multicast_is_router() uses the currently still
common ip4_mc_router_timer for now. It will be renamed to
ip6_mc_router_timer later when the split is performed.

While at it also renames the "1" and "2" constants in
br_multicast_is_router() to the MDB_RTR_TYPE_TEMP_QUERY and
MDB_RTR_TYPE_PERM enums.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for the upcoming split of multicast router state into
their IPv4 and IPv6 variants and as the br_multicast_mark_router() will
be split for that remove the select querier wrapper and instead add
ip4 and ip6 variants for br_multicast_query_received().
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for the upcoming split of multicast router state into
their IPv4 and IPv6 variants, rename the affected variable to the IPv4
version first to avoid some renames in later commits.
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The IPv6 Multicast Router Advertisements parsing has the following two
issues:

For one thing, ICMPv6 MRD Advertisements are smaller than ICMPv6 MLD
messages (ICMPv6 MRD Adv.: 8 bytes vs. ICMPv6 MLDv1/2: >= 24 bytes,
assuming MLDv2 Reports with at least one multicast address entry).
When ipv6_mc_check_mld_msg() tries to parse an Multicast Router
Advertisement its MLD length check will fail - and it will wrongly
return -EINVAL, even if we have a valid MRD Advertisement. With the
returned -EINVAL the bridge code will assume a broken packet and will
wrongly discard it, potentially leading to multicast packet loss towards
multicast routers.

The second issue is the MRD header parsing in
br_ip6_multicast_mrd_rcv(): It wrongly checks for an ICMPv6 header
immediately after the IPv6 header (IPv6 next header type). However
according to RFC4286, section 2 all MRD messages contain a Router Alert
option (just like MLD). So instead there is an IPv6 Hop-by-Hop option
for the Router Alert between the IPv6 and ICMPv6 header, again leading
to the bridge wrongly discarding Multicast Router Advertisements.

To fix these two issues, introduce a new return value -ENODATA to
ipv6_mc_check_mld() to indicate a valid ICMPv6 packet with a hop-by-hop
option which is not an MLD but potentially an MRD packet. This also
simplifies further parsing in the bridge code, as ipv6_mc_check_mld()
already fully checks the ICMPv6 header and hop-by-hop option.

These issues were found and fixed with the help of the mrdisc tool
(https://github.com/troglobit/mrdisc).

Fixes: 4b3087c7 ("bridge: Snoop Multicast Router Advertisements")
Signed-off-by: NLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When CONFIG_NET_SWITCHDEV is disabled, the shim for switchdev_port_attr_set
inside br_mc_disabled_update returns -EOPNOTSUPP. This is not caught,
and propagated to the caller of br_multicast_add_port, preventing ports
from joining the bridge.
Reported-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Fixes: ae1ea84b ("net: bridge: propagate error code and extack from br_mc_disabled_update")
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Tested-by: NChristian Borntraeger <borntraeger@de.ibm.com>
Acked-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some Ethernet switches might only be able to support disabling multicast
snooping globally, which is an issue for example when several bridges
span the same physical device and request contradictory settings.

Propagate the return value of br_mc_disabled_update() such that this
limitation is transmitted correctly to user-space.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The benefit is the ability to propagate errors from switchdev drivers
for the SWITCHDEV_ATTR_ID_BRIDGE_VLAN_FILTERING and
SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL attributes.
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...)).

net/bridge/br_multicast.c:1246:9-16: WARNING: ERR_CAST can be used with mp
Generated by: scripts/coccinelle/api/err_cast.cocci
Signed-off-by: NXu Wang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20210204070549.83636-1-vulab@iscas.ac.cnSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Add a default limit of 512 for number of tracked EHT hosts per-port.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

coccicheck suggested using PTR_ERR_OR_ZERO() and looking at the code.

Fix the following coccicheck warnings:

./net/bridge/br_multicast.c:1295:7-13: WARNING: PTR_ERR_OR_ZERO can be
used.
Reported-by: NAbaci <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Acked-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/1611542381-91178-1-git-send-email-abaci-bugfix@linux.alibaba.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Mark groups which were deleted due to fast leave/EHT.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

A block report can result in empty source and host sets for both include
and exclude groups so if there are no hosts left we can safely remove
the group. Pull the block group handling so it can cover both cases and
add a check if EHT requires the delete.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Add support for IGMPv3/MLDv2 include and exclude EHT handling. Similar to
how the reports are processed we have 2 cases when the group is in include
or exclude mode, these are processed as follows:
 - group include
  - is_include: create missing entries
  - to_include: flush existing entries and create a new set from the
    report, obviously if the src set is empty then we delete the group

 - group exclude
  - is_exclude: create missing entries
  - to_exclude: flush existing entries and create a new set from the
    report, any empty source set entries are removed

If the group is in a different mode then we just flush all entries reported
by the host and we create a new set with the new mode entries created from
the report. If the report is include type, the source list is empty and
the group has empty sources' set then we remove it. Any source set entries
which are empty are removed as well. If the group is in exclude mode it
can exist without any S,G entries (allowing for all traffic to pass).
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Add support for IGMPv3/MLDv2 allow/block EHT handling. Similar to how
the reports are processed we have 2 cases when the group is in include
or exclude mode, these are processed as follows:
 - group include
  - allow: create missing entries
  - block: remove existing matching entries and remove the corresponding
    S,G entries if there are no more set host entries, then possibly
    delete the whole group if there are no more S,G entries

 - group exclude
  - allow
    - host include: create missing entries
    - host exclude: remove existing matching entries and remove the
      corresponding S,G entries if there are no more set host entries
  - block
    - host include: remove existing matching entries and remove the
      corresponding S,G entries if there are no more set host entries,
      then possibly delete the whole group if there are no more S,G entries
    - host exclude: create missing entries
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Add EHT source set and set-entry create, delete and lookup functions.
These allow to manipulate source sets which contain their own host sets
with entries which joined that S,G. We're limiting the maximum number of
tracked S,G entries per host to PG_SRC_ENT_LIMIT (currently 32) which is
the current maximum of S,G entries for a group. There's a per-set timer
which will be used to destroy the whole set later.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Add functions to create, destroy and lookup an EHT host. These are
per-host entries contained in the eht_host_tree in net_bridge_port_group
which are used to store a list of all sources (S,G) entries joined for that
group by each host, the host's current filter mode and total number of
joined entries.
No functional changes yet, these would be used in later patches.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Add EHT structures for tracking hosts and sources per group. We keep one
set for each host which has all of the host's S,G entries, and one set for
each multicast source which has all hosts that have joined that S,G. For
each host, source entry we record the filter_mode and we keep an expiry
timer. There is also one global expiry timer per source set, it is
updated with each set entry update, it will be later used to lower the
set's timer instead of lowering each entry's timer separately.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

We need to preserve the srcs pointer since we'll be passing it for EHT
handling later.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Prepare __grp_src_block_incl() for being able to cause a notification
due to changes. Currently it cannot happen, but EHT would change that
since we'll be deleting sources immediately. Make sure that if the pg is
deleted we don't return true as that would cause the caller to access
freed pg. This patch shouldn't cause any functional change.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

We need to pass the host address so later it can be used for explicit
host tracking. No functional change.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Rename src_size argument to addr_size in preparation for passing host
address as an argument to IGMPv3/MLDv2 functions.
No functional change.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

When enabling multicast snooping, bridge module deadlocks on multicast_lock
if 1) IPv6 is enabled, and 2) there is an existing querier on the same L2
network.

The deadlock was caused by the following sequence: While holding the lock,
br_multicast_open calls br_multicast_join_snoopers, which eventually causes
IP stack to (attempt to) send out a Listener Report (in igmp6_join_group).
Since the destination Ethernet address is a multicast address, br_dev_xmit
feeds the packet back to the bridge via br_multicast_rcv, which in turn
calls br_multicast_add_group, which then deadlocks on multicast_lock.

The fix is to move the call br_multicast_join_snoopers outside of the
critical section. This works since br_multicast_join_snoopers only deals
with IP and does not modify any multicast data structures of the bridge,
so there's no need to hold the lock.

Steps to reproduce:
1. sysctl net.ipv6.conf.all.force_mld_version=1
2. have another querier
3. ip link set dev bridge type bridge mcast_snooping 0 && \
   ip link set dev bridge type bridge mcast_snooping 1 < deadlock >

A typical call trace looks like the following:

[  936.251495]  _raw_spin_lock+0x5c/0x68
[  936.255221]  br_multicast_add_group+0x40/0x170 [bridge]
[  936.260491]  br_multicast_rcv+0x7ac/0xe30 [bridge]
[  936.265322]  br_dev_xmit+0x140/0x368 [bridge]
[  936.269689]  dev_hard_start_xmit+0x94/0x158
[  936.273876]  __dev_queue_xmit+0x5ac/0x7f8
[  936.277890]  dev_queue_xmit+0x10/0x18
[  936.281563]  neigh_resolve_output+0xec/0x198
[  936.285845]  ip6_finish_output2+0x240/0x710
[  936.290039]  __ip6_finish_output+0x130/0x170
[  936.294318]  ip6_output+0x6c/0x1c8
[  936.297731]  NF_HOOK.constprop.0+0xd8/0xe8
[  936.301834]  igmp6_send+0x358/0x558
[  936.305326]  igmp6_join_group.part.0+0x30/0xf0
[  936.309774]  igmp6_group_added+0xfc/0x110
[  936.313787]  __ipv6_dev_mc_inc+0x1a4/0x290
[  936.317885]  ipv6_dev_mc_inc+0x10/0x18
[  936.321677]  br_multicast_open+0xbc/0x110 [bridge]
[  936.326506]  br_multicast_toggle+0xec/0x140 [bridge]

Fixes: 4effd28c ("bridge: join all-snoopers multicast address")
Signed-off-by: NJoseph Huang <Joseph.Huang@garmin.com>
Acked-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Link: https://lore.kernel.org/r/20201204235628.50653-1-Joseph.Huang@garmin.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Extend the bridge multicast control and data path to configure routes
for L2 (non-IP) multicast groups.

The uapi struct br_mdb_entry union u is extended with another variant,
mac_addr, which does not change the structure size, and which is valid
when the proto field is zero.

To be compatible with the forwarding code that is already in place,
which acts as an IGMP/MLD snooping bridge with querier capabilities, we
need to declare that for L2 MDB entries (for which there exists no such
thing as IGMP/MLD snooping/querying), that there is always a querier.
Otherwise, these entries would be flooded to all bridge ports and not
just to those that are members of the L2 multicast group.

Needless to say, only permanent L2 multicast groups can be installed on
a bridge port.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20201028233831.610076-1-vladimir.oltean@nxp.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

We should remove a group from the sg_port hash only if it's an S,G
entry. This makes it correct and more symmetric with group add. Also
since *,G groups are not added to that hash we can hide a bug.

Fixes: 085b53c8 ("net: bridge: mcast: add sg_port rhashtable")
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since host joins are considered as EXCLUDE {} joins we need to reflect
that in all of *,G ports' S,G entries. Since the S,Gs can have
host_joined == true only set automatically we can safely set it to false
when removing all automatically added entries upon S,G delete.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When excluding S,G entries we need a way to block a particular S,G,port.
The new port group flag is managed based on the source's timer as per
RFCs 3376 and 3810. When a source expires and its port group is in
EXCLUDE mode, it will be blocked.
Signed-off-by: NNikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>