vxlan: mdb: Add MDB bulk deletion support

Implement MDB bulk deletion support in the VXLAN driver, allowing MDB
entries to be deleted in bulk according to provided parameters.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan: mdb: Add MDB get support

Implement support for MDB get operation by looking up a matching MDB
entry, allocating the skb according to the entry's size and then filling
in the response.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan: Add MDB data path support

Integrate MDB support into the Tx path of the VXLAN driver, allowing it
to selectively forward IP multicast traffic according to the matched MDB
entry.

If MDB entries are configured (i.e., 'VXLAN_F_MDB' is set) and the
packet is an IP multicast packet, perform up to three different lookups
according to the following priority:

1. For an (S, G) entry, using {Source VNI, Source IP, Destination IP}.
2. For a (*, G) entry, using {Source VNI, Destination IP}.
3. For the catchall MDB entry (0.0.0.0 or ::), using the source VNI.

The catchall MDB entry is similar to the catchall FDB entry
(00:00:00:00:00:00) that is currently used to transmit BUM (broadcast,
unknown unicast and multicast) traffic. However, unlike the catchall FDB
entry, this entry is only used to transmit unregistered IP multicast
traffic that is not link-local. Therefore, when configured, the catchall
FDB entry will only transmit BULL (broadcast, unknown unicast,
link-local multicast) traffic.

The catchall MDB entry is useful in deployments where inter-subnet
multicast forwarding is used and not all the VTEPs in a tenant domain
are members in all the broadcast domains. In such deployments it is
advantageous to transmit BULL (broadcast, unknown unicast and link-local
multicast) and unregistered IP multicast traffic on different tunnels.
If the same tunnel was used, a VTEP only interested in IP multicast
traffic would also pull all the BULL traffic and drop it as it is not a
member in the originating broadcast domain [1].

If the packet did not match an MDB entry (or if the packet is not an IP
multicast packet), return it to the Tx path, allowing it to be forwarded
according to the FDB.

If the packet did match an MDB entry, forward it to the associated
remote VTEPs. However, if the entry is a (*, G) entry and the associated
remote is in INCLUDE mode, then skip over it as the source IP is not in
its source list (otherwise the packet would have matched on an (S, G)
entry). Similarly, if the associated remote is marked as BLOCKED (can
only be set on (S, G) entries), then skip over it as well as the remote
is in EXCLUDE mode and the source IP is in its source list.

[1] https://datatracker.ietf.org/doc/html/draft-ietf-bess-evpn-irb-mcast#section-2.6

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan: mdb: Add MDB control path support

Implement MDB control path support, enabling the creation, deletion,
replacement and dumping of MDB entries in a similar fashion to the
bridge driver. Unlike the bridge driver, each entry stores a list of
remote VTEPs to which matched packets need to be replicated to and not a
list of bridge ports.

The motivating use case is the installation of MDB entries by a user
space control plane in response to received EVPN routes. As such, only
allow permanent MDB entries to be installed and do not implement
snooping functionality, avoiding a lot of unnecessary complexity.

Since entries can only be modified by user space under RTNL, use RTNL as
the write lock. Use RCU to ensure that MDB entries and remotes are not
freed while being accessed from the data path during transmission.

In terms of uAPI, reuse the existing MDB netlink interface, but add a
few new attributes to request and response messages:

* IP address of the destination VXLAN tunnel endpoint where the
multicast receivers reside.

* UDP destination port number to use to connect to the remote VXLAN
tunnel endpoint.

* VXLAN VNI Network Identifier to use to connect to the remote VXLAN
tunnel endpoint. Required when Ingress Replication (IR) is used and
the remote VTEP is not a member of originating broadcast domain
(VLAN/VNI) [1].

* Source VNI Network Identifier the MDB entry belongs to. Used only when
the VXLAN device is in external mode.

* Interface index of the outgoing interface to reach the remote VXLAN
tunnel endpoint. This is required when the underlay destination IP is
multicast (P2MP), as the multicast routing tables are not consulted.

All the new attributes are added under the 'MDBA_SET_ENTRY_ATTRS' nest
which is strictly validated by the bridge driver, thereby automatically
rejecting the new attributes.

[1] https://datatracker.ietf.org/doc/html/draft-ietf-bess-evpn-irb-mcast#section-3.2.2

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan: Expose vxlan_xmit_one()

Given a packet and a remote destination, the function will take care of
encapsulating the packet and transmitting it to the destination.

Expose it so that it could be used in subsequent patches by the MDB code
to transmit a packet to the remote destination(s) stored in the MDB
entry.

It will allow us to keep the MDB code self-contained, not exposing its
data structures to the rest of the VXLAN driver.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan: Move address helpers to private headers

Move the helpers out of the core C file to the private header so that
they could be used by the upcoming MDB code.

While at it, constify the second argument of vxlan_nla_get_addr().

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers: vxlan: vnifilter: per vni stats

Add per-vni statistics for vni filter mode. Counting Rx/Tx
bytes/packets/drops/errors at the appropriate places.

This patch changes vxlan_vs_find_vni to also return the
vxlan_vni_node in cases where the vni belongs to a vni
filtering vxlan device

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan: vni filtering support on collect metadata device

This patch adds vnifiltering support to collect metadata device.

Motivation:
You can only use a single vxlan collect metadata device for a given
vxlan udp port in the system today. The vxlan collect metadata device
terminates all received vxlan packets. As shown in the below diagram,
there are use-cases where you need to support multiple such vxlan devices in
independent bridge domains. Each vxlan device must terminate the vni's
it is configured for.
Example usecase: In a service provider network a service provider
typically supports multiple bridge domains with overlapping vlans.
One bridge domain per customer. Vlans in each bridge domain are
mapped to globally unique vxlan ranges assigned to each customer.

vnifiltering support in collect metadata devices terminates only configured
vnis. This is similar to vlan filtering in bridge driver. The vni filtering
capability is provided by a new flag on collect metadata device.

In the below pic:
- customer1 is mapped to br1 bridge domain
- customer2 is mapped to br2 bridge domain
- customer1 vlan 10-11 is mapped to vni 1001-1002
- customer2 vlan 10-11 is mapped to vni 2001-2002
- br1 and br2 are vlan filtering bridges
- vxlan1 and vxlan2 are collect metadata devices with
vnifiltering enabled

┌──────────────────────────────────────────────────────────────────┐
│ switch │
│ │
│ ┌───────────┐ ┌───────────┐ │
│ │ │ │ │ │
│ │ br1 │ │ br2 │ │
│ └┬─────────┬┘ └──┬───────┬┘ │
│ vlans│ │ vlans │ │ │
│ 10,11│ │ 10,11│ │ │
│ │ vlanvnimap: │ vlanvnimap: │
│ │ 10-1001,11-1002 │ 10-2001,11-2002 │
│ │ │ │ │ │
│ ┌──────┴┐ ┌──┴─────────┐ ┌───┴────┐ │ │
│ │ swp1 │ │vxlan1 │ │ swp2 │ ┌┴─────────────┐ │
│ │ │ │ vnifilter:│ │ │ │vxlan2 │ │
│ └───┬───┘ │ 1001,1002│ └───┬────┘ │ vnifilter: │ │
│ │ └────────────┘ │ │ 2001,2002 │ │
│ │ │ └──────────────┘ │
│ │ │ │
└───────┼──────────────────────────────────┼───────────────────────┘
│ │
│ │
┌─────┴───────┐ │
│ customer1 │ ┌─────┴──────┐
│ host/VM │ │customer2 │
└─────────────┘ │ host/VM │
└────────────┘

With this implementation, vxlan dst metadata device can
be associated with range of vnis.
struct vxlan_vni_node is introduced to represent
a configured vni. We start with vni and its
associated remote_ip in this structure. This
structure can be extended to bring in other
per vni attributes if there are usecases for it.
A vni inherits an attribute from the base vxlan device
if there is no per vni attributes defined.

struct vxlan_dev gets a new rhashtable for
vnis called vxlan_vni_group. vxlan_vnifilter.c
implements the necessary netlink api, notifications
and helper functions to process and manage lifecycle
of vxlan_vni_node.

This patch also adds new helper functions in vxlan_multicast.c
to handle per vni remote_ip multicast groups which are part
of vxlan_vni_group.

Fix build problems:
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan_multicast: Move multicast helpers to a separate file

subsequent patches will add more helpers.

Signed-off-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan_core: move some fdb helpers to non-static

This patch moves some fdb helpers to non-static
for use in later patches. Ideally, all fdb code
could move into its own file vxlan_fdb.c.
This can be done as a subsequent patch and is out
of scope of this series.

Signed-off-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

vxlan_core: move common declarations to private header file

This patch moves common structures and global declarations
to a shared private headerfile vxlan_private.h. Subsequent
patches use this header file as a common header file for
additional shared declarations.

Signed-off-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>