linux-stable.git/include/net/vxlan.h, branch linux-5.4.y

vxlan: calculate correct header length for GPE

2023-08-11T09:53:47+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: add adjacent link to limit depth level

2019-10-24T21:53:49+00:00

Current vxlan code doesn't limit the number of nested devices.
Nested devices would be handled recursively and this routine needs
huge stack memory. So, unlimited nested devices could make
stack overflow.

In order to fix this issue, this patch adds adjacent links.
The adjacent link APIs internally check the depth level.

Test commands:
    ip link add dummy0 type dummy
    ip link add vxlan0 type vxlan id 0 group 239.1.1.1 dev dummy0 \
	    dstport 4789
    for i in {1..100}
    do
	    let A=$i-1
	    ip link add vxlan$i type vxlan id $i group 239.1.1.1 \
		    dev vxlan$A dstport 4789
    done
    ip link del dummy0

The top upper link is vxlan100 and the lowest link is vxlan0.
When vxlan0 is deleting, the upper devices will be deleted recursively.
It needs huge stack memory so it makes stack overflow.

Splat looks like:
[  229.628477] =============================================================================
[  229.629785] BUG page->ptl (Not tainted): Padding overwritten. 0x0000000026abf214-0x0000000091f6abb2
[  229.629785] -----------------------------------------------------------------------------
[  229.629785]
[  229.655439] ==================================================================
[  229.629785] INFO: Slab 0x00000000ff7cfda8 objects=19 used=19 fp=0x00000000fe33776c flags=0x200000000010200
[  229.655688] BUG: KASAN: stack-out-of-bounds in unmap_single_vma+0x25a/0x2e0
[  229.655688] Read of size 8 at addr ffff888113076928 by task vlan-network-in/2334
[  229.655688]
[  229.629785] Padding 0000000026abf214: 00 80 14 0d 81 88 ff ff 68 91 81 14 81 88 ff ff  ........h.......
[  229.629785] Padding 0000000001e24790: 38 91 81 14 81 88 ff ff 68 91 81 14 81 88 ff ff  8.......h.......
[  229.629785] Padding 00000000b39397c8: 33 30 62 a7 ff ff ff ff ff eb 60 22 10 f1 ff 1f  30b.......`"....
[  229.629785] Padding 00000000bc98f53a: 80 60 07 13 81 88 ff ff 00 80 14 0d 81 88 ff ff  .`..............
[  229.629785] Padding 000000002aa8123d: 68 91 81 14 81 88 ff ff f7 21 17 a7 ff ff ff ff  h........!......
[  229.629785] Padding 000000001c8c2369: 08 81 14 0d 81 88 ff ff 03 02 00 00 00 00 00 00  ................
[  229.629785] Padding 000000004e290c5d: 21 90 a2 21 10 ed ff ff 00 00 00 00 00 fc ff df  !..!............
[  229.629785] Padding 000000000e25d731: 18 60 07 13 81 88 ff ff c0 8b 13 05 81 88 ff ff  .`..............
[  229.629785] Padding 000000007adc7ab3: b3 8a b5 41 00 00 00 00                          ...A....
[  229.629785] FIX page->ptl: Restoring 0x0000000026abf214-0x0000000091f6abb2=0x5a
[  ... ]

Fixes: acaf4e70997f ("net: vxlan: when lower dev unregisters remove vxlan dev as well")
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller

Convert usage of IN_MULTICAST to ipv4_is_multicast

2019-09-05T07:38:32+00:00

IN_MULTICAST's primary intent is as a uapi macro.

Elsewhere in the kernel we use ipv4_is_multicast consistently.

This patch unifies linux's multicast checks to use that function
rather than this macro.

Signed-off-by: Dave Taht 
Reviewed-by: Toke Høiland-Jørgensen 
Signed-off-by: David S. Miller

vxlan: Use FDB_HASH_SIZE hash_locks to reduce contention

2019-06-06T18:08:55+00:00

The monolithic hash_lock could cause huge contention when
inserting/deletiing vxlan_fdbs into the fdb_head.

Use FDB_HASH_SIZE hash_locks to protect insertions/deletions
of vxlan_fdbs into the fdb_head hash table.

Suggested-by: David S. Miller 
Signed-off-by: Litao jiao 
Signed-off-by: David S. Miller

net: Add IANA_VXLAN_UDP_PORT definition to vxlan header file

2019-03-22T19:09:31+00:00

Added IANA_VXLAN_UDP_PORT (4789) definition to vxlan header file so it
can be used by drivers instead of local definition.
Updated drivers which locally defined it as 4789 to use it.

Signed-off-by: Moshe Shemesh 
Reviewed-by: Or Gerlitz 
Cc: John Hurley 
Cc: Jakub Kicinski 
Cc: Yunsheng Lin 
Cc: Peng Li 
Reviewed-by: Tariq Toukan 
Acked-by: Jakub Kicinski 
Signed-off-by: Saeed Mahameed

vxlan: add extack support for create and changelink

2019-02-26T16:54:37+00:00

This patch adds extack coverage in vxlan link
create and changelink paths. Introduces a new helper
vxlan_nl2flags to consolidate flag attribute validation.

thanks to Johannes Berg for some tips to construct the
generic vxlan flag extack strings.

Signed-off-by: Roopa Prabhu 
Reviewed-by: Petr Machata 
Signed-off-by: David S. Miller

vxlan: Add extack to switchdev operations

2019-01-17T23:18:47+00:00

There are four sources of VXLAN switchdev notifier calls:

- the changelink() link operation, which already supports extack,
- ndo_fdb_add() which got extack support in a previous patch,
- FDB updates due to packet forwarding,
- and vxlan_fdb_replay().

Extend vxlan_fdb_switchdev_call_notifiers() to include extack in the
switchdev message that it sends, and propagate the argument upwards to
the callers. For the first two cases, pass in the extack gotten through
the operation. For case #3, pass in NULL.

To cover the last case, extend vxlan_fdb_replay() to take extack
argument, which might come from whatever operation necessitated the FDB
replay.

Signed-off-by: Petr Machata 
Signed-off-by: David S. Miller

vxlan: Add vxlan_fdb_clear_offload()

2018-12-07T20:59:08+00:00

When a driver unoffloads all FDB entries en bloc, it's inefficient to
send the switchdev notification one by one. Add a helper that walks the
FDB table, unsetting the offload flag on RDST with a given VNI.

Signed-off-by: Petr Machata 
Signed-off-by: Ido Schimmel 
Signed-off-by: David S. Miller

vxlan: Add vxlan_fdb_replay()

2018-12-07T20:59:08+00:00

When a VXLAN device becomes relevant to a driver (such as when it is
attached to an offloaded bridge), the driver will generally need to walk
the existing FDB entries and offload them.

Add a function vxlan_fdb_replay() to call a given notifier block for
each FDB entry with a given VNI.

Signed-off-by: Petr Machata 
Signed-off-by: Ido Schimmel 
Signed-off-by: David S. Miller

vxlan: Mark user-added FDB entries

2018-11-22T01:10:30+00:00

The VXLAN driver needs to differentiate between FDB entries learned by
the VXLAN driver, and those added by the user. The latter ones shouldn't
be taken over by external learning events. This is in accordance with
bridge behavior.

Therefore, extend the flags bitfield to 16 bits and add a new private
NTF flag to mark the user-added entries.

This seems preferable to adding a dedicated boolean, because passing the
flag, unlike passing e.g. a true, makes it clear what the meaning of the
bit is.

Signed-off-by: Petr Machata 
Signed-off-by: Ido Schimmel 
Signed-off-by: David S. Miller