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mirror of https://github.com/edk2-porting/linux-next.git synced 2025-01-04 03:33:58 +08:00
linux-next/include
Daniel Borkmann 7482e3841d net, neigh: Add NTF_MANAGED flag for managed neighbor entries
Allow a user space control plane to insert entries with a new NTF_EXT_MANAGED
flag. The flag then indicates to the kernel that the neighbor entry should be
periodically probed for keeping the entry in NUD_REACHABLE state iff possible.

The use case for this is targeting XDP or tc BPF load-balancers which use
the bpf_fib_lookup() BPF helper in order to piggyback on neighbor resolution
for their backends. Given they cannot be resolved in fast-path, a control
plane inserts the L3 (without L2) entries manually into the neighbor table
and lets the kernel do the neighbor resolution either on the gateway or on
the backend directly in case the latter resides in the same L2. This avoids
to deal with L2 in the control plane and to rebuild what the kernel already
does best anyway.

NTF_EXT_MANAGED can be combined with NTF_EXT_LEARNED in order to avoid GC
eviction. The kernel then adds NTF_MANAGED flagged entries to a per-neighbor
table which gets triggered by the system work queue to periodically call
neigh_event_send() for performing the resolution. The implementation allows
migration from/to NTF_MANAGED neighbor entries, so that already existing
entries can be converted by the control plane if needed. Potentially, we could
make the interval for periodically calling neigh_event_send() configurable;
right now it's set to DELAY_PROBE_TIME which is also in line with mlxsw which
has similar driver-internal infrastructure c723c735fa ("mlxsw: spectrum_router:
Periodically update the kernel's neigh table"). In future, the latter could
possibly reuse the NTF_MANAGED neighbors as well.

Example:

  # ./ip/ip n replace 192.168.178.30 dev enp5s0 managed extern_learn
  # ./ip/ip n
  192.168.178.30 dev enp5s0 lladdr f4:8c:50:5e:71:9a managed extern_learn REACHABLE
  [...]

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Link: https://linuxplumbersconf.org/event/11/contributions/953/
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-12 11:27:47 +01:00
..
acpi Revert "ACPI: Add memory semantics to acpi_os_map_memory()" 2021-09-23 20:39:36 +02:00
asm-generic pci_iounmap'2: Electric Boogaloo: try to make sense of it all 2021-09-19 17:13:35 -07:00
clocksource
crypto
drm
dt-bindings linux-watchdog 5.15-rc1 tag 2021-09-07 13:52:46 -07:00
keys
kunit
kvm KVM: arm64: Fix PMU probe ordering 2021-09-20 12:43:34 +01:00
linux mlxsw: spectrum: use netif_is_macsec() instead of open code 2021-10-10 11:18:48 +01:00
math-emu
media
memory
misc
net net, neigh: Add NTF_MANAGED flag for managed neighbor entries 2021-10-12 11:27:47 +01:00
pcmcia
ras
rdma
scsi scsi: core: Remove 'current_tag' 2021-09-22 00:13:38 -04:00
soc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-10-07 15:24:06 -07:00
sound ALSA: rawmidi: introduce SNDRV_RAWMIDI_IOCTL_USER_PVERSION 2021-09-23 09:26:40 +02:00
target
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-10-07 15:24:06 -07:00
uapi net, neigh: Add NTF_MANAGED flag for managed neighbor entries 2021-10-12 11:27:47 +01:00
vdso
video
xen swiotlb-xen: this is PV-only on x86 2021-09-20 17:01:21 +02:00