linux.git/include/uapi/linux/neighbour.h, branch v5.8

vxlan: ecmp support for mac fdb entries

2020-05-22T21:00:38+00:00

Todays vxlan mac fdb entries can point to multiple remote
ips (rdsts) with the sole purpose of replicating
broadcast-multicast and unknown unicast packets to those remote ips.

E-VPN multihoming [1,2,3] requires bridged vxlan traffic to be
load balanced to remote switches (vteps) belonging to the
same multi-homed ethernet segment (E-VPN multihoming is analogous
to multi-homed LAG implementations, but with the inter-switch
peerlink replaced with a vxlan tunnel). In other words it needs
support for mac ecmp. Furthermore, for faster convergence, E-VPN
multihoming needs the ability to update fdb ecmp nexthops independent
of the fdb entries.

New route nexthop API is perfect for this usecase.
This patch extends the vxlan fdb code to take a nexthop id
pointing to an ecmp nexthop group.

Changes include:
- New NDA_NH_ID attribute for fdbs
- Use the newly added fdb nexthop groups
- makes vxlan rdsts and nexthop handling code mutually
  exclusive
- since this is a new use-case and the requirement is for ecmp
nexthop groups, the fdb add and update path checks that the
nexthop is really an ecmp nexthop group. This check can be relaxed
in the future, if we want to introduce replication fdb nexthop groups
and allow its use in lieu of current rdst lists.
- fdb update requests with nexthop id's only allowed for existing
fdb's that have nexthop id's
- learning will not override an existing fdb entry with nexthop
group
- I have wrapped the switchdev offload code around the presence of
rdst

[1] E-VPN RFC https://tools.ietf.org/html/rfc7432
[2] E-VPN with vxlan https://tools.ietf.org/html/rfc8365
[3] http://vger.kernel.org/lpc_net2018_talks/scaling_bridge_fdb_database_slidesV3.pdf

Includes a null check fix in vxlan_xmit from Nikolay

v2 - Fixed build issue:
Reported-by: kbuild test robot 
Signed-off-by: Roopa Prabhu 
Signed-off-by: David S. Miller

neighbor: Add protocol attribute

2018-12-16T20:15:25+00:00

Similar to routes and rules, add protocol attribute to neighbor entries
for easier tracking of how each was created.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

net: bridge: add support for sticky fdb entries

2018-09-13T03:30:03+00:00

Add support for entries which are "sticky", i.e. will not change their port
if they show up from a different one. A new ndm flag is introduced for that
purpose - NTF_STICKY. We allow to set it only to non-local entries.

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

License cleanup: add SPDX license identifier to uapi header files with no license

2017-11-02T10:19:54+00:00

Many user space API headers are missing licensing information, which
makes it hard for compliance tools to determine the correct license.

By default are files without license information under the default
license of the kernel, which is GPLV2.  Marking them GPLV2 would exclude
them from being included in non GPLV2 code, which is obviously not
intended. The user space API headers fall under the syscall exception
which is in the kernels COPYING file:

   NOTE! This copyright does *not* cover user programs that use kernel
   services by normal system calls - this is merely considered normal use
   of the kernel, and does *not* fall under the heading of "derived work".

otherwise syscall usage would not be possible.

Update the files which contain no license information with an SPDX
license identifier.  The chosen identifier is 'GPL-2.0 WITH
Linux-syscall-note' which is the officially assigned identifier for the
Linux syscall exception.  SPDX license identifiers are a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.  See the previous patch in this series for the
methodology of how this patch was researched.

Reviewed-by: Kate Stewart 
Reviewed-by: Philippe Ombredanne 
Reviewed-by: Thomas Gleixner 
Signed-off-by: Greg Kroah-Hartman

net: bridge: Receive notification about successful FDB offload

2017-06-08T18:16:25+00:00

When a new static FDB is added to the bridge a notification is sent to
the driver for offload. In case of successful offload the driver should
notify the bridge back, which in turn should mark the FDB as offloaded.

Currently, externally learned is equivalent for being offloaded which is
not correct due to the fact that FDBs which are added from user-space are
also marked as externally learned. In order to specify if an FDB was
successfully offloaded a new flag is introduced.

Signed-off-by: Arkadi Sharshevsky 
Reviewed-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Signed-off-by: Jiri Pirko 
Signed-off-by: David S. Miller

vxlan: support fdb and learning in COLLECT_METADATA mode

2017-02-03T20:21:21+00:00

Vxlan COLLECT_METADATA mode today solves the per-vni netdev
scalability problem in l3 networks. It expects all forwarding
information to be present in dst_metadata. This patch series
enhances collect metadata mode to include the case where only
vni is present in dst_metadata, and the vxlan driver can then use
the rest of the forwarding information datbase to make forwarding
decisions. There is no change to default COLLECT_METADATA
behaviour. These changes only apply to COLLECT_METADATA when
used with the bridging use-case with a special dst_metadata
tunnel info flag (eg: where vxlan device is part of a bridge).
For all this to work, the vxlan driver will need to now support a
single fdb table hashed by mac + vni. This series essentially makes
this happen.

use-case and workflow:
vxlan collect metadata device participates in bridging vlan
to vn-segments. Bridge driver above the vxlan device,
sends the vni corresponding to the vlan in the dst_metadata.
vxlan driver will lookup forwarding database with (mac + vni)
for the required remote destination information to forward the
packet.

Changes introduced by this patch:
    - allow learning and forwarding database state in vxlan netdev in
      COLLECT_METADATA mode. Current behaviour is not changed
      by default. tunnel info flag IP_TUNNEL_INFO_BRIDGE is used
      to support the new bridge friendly mode.
    - A single fdb table hashed by (mac, vni) to allow fdb entries with
      multiple vnis in the same fdb table
    - rx path already has the vni
    - tx path expects a vni in the packet with dst_metadata
    - prior to this series, fdb remote_dsts carried remote vni and
      the vxlan device carrying the fdb table represented the
      source vni. With the vxlan device now representing multiple vnis,
      this patch adds a src vni attribute to the fdb entry. The remote
      vni already uses NDA_VNI attribute. This patch introduces
      NDA_SRC_VNI netlink attribute to represent the src vni in a multi
      vni fdb table.

iproute2 example (patched and pruned iproute2 output to just show
relevant fdb entries):
example shows same host mac learnt on two vni's.

before (netdev per vni):
$bridge fdb show | grep "00:02:00:00:00:03"
00:02:00:00:00:03 dev vxlan1001 dst 12.0.0.8 self
00:02:00:00:00:03 dev vxlan1000 dst 12.0.0.8 self

after this patch with collect metadata in bridged mode (single netdev):
$bridge fdb show | grep "00:02:00:00:00:03"
00:02:00:00:00:03 dev vxlan0 src_vni 1001 dst 12.0.0.8 self
00:02:00:00:00:03 dev vxlan0 src_vni 1000 dst 12.0.0.8 self

Signed-off-by: Roopa Prabhu 
Signed-off-by: David S. Miller

libnl: nla_put_msecs(): align on a 64-bit area

2016-04-24T00:13:24+00:00

nla_data() is now aligned on a 64-bit area.

Signed-off-by: Nicolas Dichtel 
Signed-off-by: David S. Miller

net: add explicit logging and stat for neighbour table overflow

2015-08-10T20:46:21+00:00

Add an explicit neighbour table overflow message (ratelimited) and
statistic to make diagnosing neighbour table overflows tractable in
the wild.

Diagnosing a neighbour table overflow can be quite difficult in the wild
because there is no explicit dmesg logged.  Callers to neighbour code
seem to use net_dbg_ratelimit when the neighbour call fails which means
the "base message" is not emitted and the callback suppressed messages
from the ratelimiting can end-up juxtaposed with unrelated messages.
Further, a forced garbage collection will increment a stat on each call
whether it was successful in freeing-up a table entry or not, so that
statistic is only a hint.  So, add a net_info_ratelimited message and
explicit statistic to the neighbour code.

Signed-off-by: Rick Jones 
Signed-off-by: David S. Miller

net: neighbour: Add mcast_resolicit to configure the number of multicast resolicitations in PROBE state.

2015-03-21T01:47:40+00:00

We send unicast neighbor (ARP or NDP) solicitations ucast_probes
times in PROBE state.  Zhu Yanjun reported that some implementation
does not reply against them and the entry will become FAILED, which
is undesirable.

We had been dealt with such nodes by sending multicast probes mcast_
solicit times after unicast probes in PROBE state.  In 2003, I made
a change not to send them to improve compatibility with IPv6 NDP.

Let's introduce per-protocol per-interface sysctl knob "mcast_
reprobe" to configure the number of multicast (re)solicitation for
reconfirmation in PROBE state.  The default is 0, since we have
been doing so for 10+ years.

Reported-by: Zhu Yanjun 
CC: Ulf Samuelsson 
Signed-off-by: YOSHIFUJI Hideaki 
Signed-off-by: YOSHIFUJI Hideaki 
Signed-off-by: David S. Miller

vxlan: advertise link netns in fdb messages

2015-01-28T01:11:07+00:00

Previous commit is based on a wrong assumption, fdb messages are always sent
into the netns where the interface stands (see vxlan_fdb_notify()).

These fdb messages doesn't embed the rtnl attribute IFLA_LINK_NETNSID, thus we
need to add it (useful to interpret NDA_IFINDEX or NDA_DST for example).

Note also that vxlan_nlmsg_size() was not updated.

Fixes: 193523bf9373 ("vxlan: advertise netns of vxlan dev in fdb msg")
Signed-off-by: Nicolas Dichtel 
Signed-off-by: David S. Miller