Add basic infrastructure for handling ovpn interfaces.

Tested-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
Link: https://patch.msgid.link/20250415-b4-ovpn-v26-3-577f6097b964@openvpn.net
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Since commit 05c1280a2bcf ("netdev_features: convert NETIF_F_NETNS_LOCAL to
dev->netns_local"), there is no way to see if the netns_immutable property
s set on a device. Let's add a netlink attribute to advertise it.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Recently, in case of Cilium, we run into users on Azure who require to use
tunneling for east/west traffic due to hitting IPAM API limits for Kubernetes
Pods if they would have gone with publicly routable IPs for Pods. In case
of tunneling, Cilium supports the option of vxlan or geneve. In order to
RSS spread flows among remote CPUs both derive a source port hash via
udp_flow_src_port() which takes the inner packet's skb->hash into account.
For clusters with many nodes, this can then hit a new limitation [0]: Today,
the Azure networking stack supports 1M total flows (500k inbound and 500k
outbound) for a VM. [...] Once this limit is hit, other connections are
dropped. [...] Each flow is distinguished by a 5-tuple (protocol, local IP
address, remote IP address, local port, and remote port) information. [...]

For vxlan and geneve, this can create a massive amount of UDP flows which
then run into the limits if stale flows are not evicted fast enough. One
option to mitigate this for vxlan is to narrow the source port range via
IFLA_VXLAN_PORT_RANGE while still being able to benefit from RSS. However,
geneve currently does not have this option and it spreads traffic across
the full source port range of [1, USHRT_MAX]. To overcome this limitation
also for geneve, add an equivalent IFLA_GENEVE_PORT_RANGE setting for users.

Note that struct geneve_config before/after still remains at 2 cachelines
on x86-64. The low/high members of struct ifla_geneve_port_range (which is
uapi exposed) are of type __be16. While they would be perfectly fine to be
of __u16 type, the consensus was that it would be good to be consistent
with the existing struct ifla_vxlan_port_range from a uapi consumer PoV.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://learn.microsoft.com/en-us/azure/virtual-network/virtual-machine-network-throughput [0]
Link: https://patch.msgid.link/20250226182030.89440-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Daniel Borkmann says:

====================
pull-request: bpf-next 2025-01-07

We've added 7 non-merge commits during the last 32 day(s) which contain
a total of 11 files changed, 190 insertions(+), 103 deletions(-).

The main changes are:

1) Migrate the test_xdp_meta.sh BPF selftest into test_progs
   framework, from Bastien Curutchet.

2) Add ability to configure head/tailroom for netkit devices,
   from Daniel Borkmann.

3) Fixes and improvements to the xdp_hw_metadata selftest,
   from Song Yoong Siang.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  selftests/bpf: Extend netkit tests to validate set {head,tail}room
  netkit: Add add netkit {head,tail}room to rt_link.yaml
  netkit: Allow for configuring needed_{head,tail}room
  selftests/bpf: Migrate test_xdp_meta.sh into xdp_context_test_run.c
  selftests/bpf: test_xdp_meta: Rename BPF sections
  selftests/bpf: Enable Tx hwtstamp in xdp_hw_metadata
  selftests/bpf: Actuate tx_metadata_len in xdp_hw_metadata
====================

Link: https://patch.msgid.link/20250107130908.143644-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Allow the user to configure needed_{head,tail}room for both netkit
devices. The idea is similar to 163e529200af ("veth: implement
ndo_set_rx_headroom") with the difference that the two parameters
can be specified upon device creation. By default the current behavior
stays as is which is needed_{head,tail}room is 0.

In case of Cilium, for example, the netkit devices are not enslaved
into a bridge or openvswitch device (rather, BPF-based redirection
is used out of tcx), and as such these parameters are not propagated
into the Pod's netns via peer device.

Given Cilium can run in vxlan/geneve tunneling mode (needed_headroom)
and/or be used in combination with WireGuard (needed_{head,tail}room),
allow the Cilium CNI plugin to specify these two upon netkit device
creation.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/bpf/20241220234658.490686-1-daniel@iogearbox.net

The set of bits that the VXLAN netdevice currently considers reserved is
defined by the features enabled at the netdevice construction. In order to
make this configurable, add an attribute, IFLA_VXLAN_RESERVED_BITS. The
payload is a pair of big-endian u32's covering the VXLAN header. This is
validated against the set of flags used by the various enabled VXLAN
features, and attempts to override bits used by an enabled feature are
bounced.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/c657275e5ceed301e62c69fe8e559e32909442e2.1733412063.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

MCTP control protocol implementations are transport binding dependent.
Endpoint discovery is mandatory based on transport binding.
Message timing requirements are specified in each respective transport
binding specification.

However, we currently have no means to get this information from MCTP
links.

Add a IFLA_MCTP_PHYS_BINDING netlink link attribute, which represents
the transport type using the DMTF DSP0239-defined type numbers, returned
as part of RTM_GETLINK data.

We get an IFLA_MCTP_PHYS_BINDING attribute for each MCTP link, for
example:

- 0x00 (unspec) for loopback interface;
- 0x01 (SMBus/I2C) for mctpi2c%d interfaces; and
- 0x05 (serial) for mctpserial%d interfaces.

Signed-off-by: Khang Nguyen <khangng@os.amperecomputing.com>
Reviewed-by: Matt Johnston <matt@codeconstruct.com.au>
Link: https://patch.msgid.link/20241105071915.821871-1-khangng@os.amperecomputing.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Daniel Borkmann says:

====================
pull-request: bpf-next 2024-10-14

The following pull-request contains BPF updates for your *net-next* tree.

We've added 21 non-merge commits during the last 18 day(s) which contain
a total of 21 files changed, 1185 insertions(+), 127 deletions(-).

The main changes are:

1) Put xsk sockets on a struct diet and add various cleanups. Overall, this helps
   to bump performance by 12% for some workloads, from Maciej Fijalkowski.

2) Extend BPF selftests to increase coverage of XDP features in combination
   with BPF cpumap, from Alexis Lothoré (eBPF Foundation).

3) Extend netkit with an option to delegate skb->{mark,priority} scrubbing to
   its BPF program, from Daniel Borkmann.

4) Make the bpf_get_netns_cookie() helper available also to tc(x) BPF programs,
   from Mahe Tardy.

5) Extend BPF selftests covering a BPF program setting socket options per MPTCP
   subflow, from Geliang Tang and Nicolas Rybowski.

bpf-next-for-netdev

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (21 commits)
  xsk: Use xsk_buff_pool directly for cq functions
  xsk: Wrap duplicated code to function
  xsk: Carry a copy of xdp_zc_max_segs within xsk_buff_pool
  xsk: Get rid of xdp_buff_xsk::orig_addr
  xsk: s/free_list_node/list_node/
  xsk: Get rid of xdp_buff_xsk::xskb_list_node
  selftests/bpf: check program redirect in xdp_cpumap_attach
  selftests/bpf: make xdp_cpumap_attach keep redirect prog attached
  selftests/bpf: fix bpf_map_redirect call for cpu map test
  selftests/bpf: add tcx netns cookie tests
  bpf: add get_netns_cookie helper to tc programs
  selftests/bpf: add missing header include for htons
  selftests/bpf: Extend netkit tests to validate skb meta data
  tools: Sync if_link.h uapi tooling header
  netkit: Add add netkit scrub support to rt_link.yaml
  netkit: Simplify netkit mode over to use NLA_POLICY_MAX
  netkit: Add option for scrubbing skb meta data
  bpf: Remove unused macro
  selftests/bpf: Add mptcp subflow subtest
  selftests/bpf: Add getsockopt to inspect mptcp subflow
  ...
====================

Link: https://patch.msgid.link/20241014211110.16562-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Jordan reported that when running Cilium with netkit in per-endpoint-routes
mode, network policy misclassifies traffic. In this direct routing mode
of Cilium which is used in case of GKE/EKS/AKS, the Pod's BPF program to
enforce policy sits on the netkit primary device's egress side.

The issue here is that in case of netkit's netkit_prep_forward(), it will
clear meta data such as skb->mark and skb->priority before executing the
BPF program. Thus, identity data stored in there from earlier BPF programs
(e.g. from tcx ingress on the physical device) gets cleared instead of
being made available for the primary's program to process. While for traffic
egressing the Pod via the peer device this might be desired, this is
different for the primary one where compared to tcx egress on the host
veth this information would be available.

To address this, add a new parameter for the device orchestration to
allow control of skb->mark and skb->priority scrubbing, to make the two
accessible from BPF (and eventually leave it up to the program to scrub).
By default, the current behavior is retained. For netkit peer this also
enables the use case where applications could cooperate/signal intent to
the BPF program.

Note that struct netkit has a 4 byte hole between policy and bundle which
is used here, in other words, struct netkit's first cacheline content used
in fast-path does not get moved around.

Fixes: 35dfaad7188c ("netkit, bpf: Add bpf programmable net device")
Reported-by: Jordan Rife <jrife@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://github.com/cilium/cilium/issues/34042
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20241004101335.117711-1-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Some network devices have the ability to offload EDT (Earliest
Departure Time) which is the model used for TCP pacing and FQ
packet scheduler.

Some of them implement the timing wheel mechanism described in
https://saeed.github.io/files/carousel-sigcomm17.pdf
with an associated 'timing wheel horizon'.

This patch adds dev->max_pacing_offload_horizon expressing
this timing wheel horizon in nsec units.

This is a read-only attribute.

Unless a driver sets it, dev->max_pacing_offload_horizon
is zero.

v2: addressed Jakub feedback ( https://lore.kernel.org/netdev/20240930152304.472767-2-edumazet@google.com/T/#mf6294d714c41cc459962154cc2580ce3c9693663 )
v3: added yaml doc (also per Jakub feedback)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20241003121219.2396589-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>