linux-stable.git/drivers/net/vxlan, branch v6.4.8

vxlan: fix GRO with VXLAN-GPE

2023-08-03T08:25:50+00:00

[ Upstream commit b0b672c4d0957e5897685667fc848132b8bd2d71 ]

In VXLAN-GPE, there may not be an Ethernet header following the VXLAN
header. But in GRO, the vxlan driver calls eth_gro_receive
unconditionally, which means the following header is incorrectly parsed
as Ethernet.

Introduce GPE specific GRO handling.

For better performance, do not check for GPE during GRO but rather
install a different set of functions at setup time.

Fixes: e1e5314de08ba ("vxlan: implement GPE")
Reported-by: Paolo Abeni 
Signed-off-by: Jiri Benc 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

vxlan: generalize vxlan_parse_gpe_hdr and remove unused args

2023-08-03T08:25:50+00:00

[ Upstream commit 17a0a64448b568442a101de09575f81ffdc45d15 ]

The vxlan_parse_gpe_hdr function extracts the next protocol value from
the GPE header and marks GPE bits as parsed.

In order to be used in the next patch, split the function into protocol
extraction and bit marking. The bit marking is meaningful only in
vxlan_rcv; move it directly there.

Rename the function to vxlan_parse_gpe_proto to reflect what it now
does. Remove unused arguments skb and vxflags. Move the function earlier
in the file to allow it to be called from more places in the next patch.

Signed-off-by: Jiri Benc 
Signed-off-by: David S. Miller 
Stable-dep-of: b0b672c4d095 ("vxlan: fix GRO with VXLAN-GPE")
Signed-off-by: Sasha Levin

vxlan: calculate correct header length for GPE

2023-08-03T08:25:50+00:00

[ Upstream commit 94d166c5318c6edd1e079df8552233443e909c33 ]

VXLAN-GPE does not add an extra inner Ethernet header. Take that into
account when calculating header length.

This causes problems in skb_tunnel_check_pmtu, where incorrect PMTU is
cached.

In the collect_md mode (which is the only mode that VXLAN-GPE
supports), there's no magic auto-setting of the tunnel interface MTU.
It can't be, since the destination and thus the underlying interface
may be different for each packet.

So, the administrator is responsible for setting the correct tunnel
interface MTU. Apparently, the administrators are capable enough to
calculate that the maximum MTU for VXLAN-GPE is (their_lower_MTU - 36).
They set the tunnel interface MTU to 1464. If you run a TCP stream over
such interface, it's then segmented according to the MTU 1464, i.e.
producing 1514 bytes frames. Which is okay, this still fits the lower
MTU.

However, skb_tunnel_check_pmtu (called from vxlan_xmit_one) uses 50 as
the header size and thus incorrectly calculates the frame size to be
1528. This leads to ICMP too big message being generated (locally),
PMTU of 1450 to be cached and the TCP stream to be resegmented.

The fix is to use the correct actual header size, especially for
skb_tunnel_check_pmtu calculation.

Fixes: e1e5314de08ba ("vxlan: implement GPE")
Signed-off-by: Jiri Benc 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

vxlan: Expose helper vxlan_build_gbp_hdr

2023-03-18T05:41:16+00:00

The function vxlan_build_gbp_hdr will be used by other modules to build
gbp option in vxlan header according to gbp flags.

Signed-off-by: Gavin Li 
Reviewed-by: Gavi Teitz 
Reviewed-by: Roi Dayan 
Reviewed-by: Maor Dickman 
Acked-by: Saeed Mahameed 
Reviewed-by: Simon Horman 
Signed-off-by: Jakub Kicinski

vxlan: Remove unused argument from vxlan_build_gbp_hdr( ) and vxlan_build_gpe_hdr( )

2023-03-18T05:41:16+00:00

Remove unused argument (i.e. u32 vxflags) in vxlan_build_gbp_hdr( ) and
vxlan_build_gpe_hdr( ) function arguments.

Signed-off-by: Gavin Li 
Reviewed-by: Simon Horman 
Signed-off-by: Jakub Kicinski

vxlan: Enable MDB support

2023-03-17T08:05:50+00:00

Now that the VXLAN MDB control and data paths are in place we can expose
the VXLAN MDB functionality to user space.

Set the VXLAN MDB net device operations to the appropriate functions,
thereby allowing the rtnetlink code to reach the VXLAN driver.

Signed-off-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

vxlan: Add MDB data path support

2023-03-17T08:05:50+00:00

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 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

vxlan: mdb: Add an internal flag to indicate MDB usage

2023-03-17T08:05:49+00:00

Add an internal flag to indicate whether MDB entries are configured or
not. Set the flag after installing the first MDB entry and clear it
before deleting the last one.

The flag will be consulted by the data path which will only perform an
MDB lookup if the flag is set, thereby keeping the MDB overhead to a
minimum when the MDB is not used.

Another option would have been to use a static key, but it is global and
not per-device, unlike the current approach.

Signed-off-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

vxlan: mdb: Add MDB control path support

2023-03-17T08:05:49+00:00

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 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller

vxlan: Expose vxlan_xmit_one()

2023-03-17T08:05:49+00:00

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 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller