vxlan: vnifilter: signal interrupted RTM_GETTUNNEL dumps

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vxlan_vnifilter_dump() walks all vxlan devices of a netns, and for each
one walks vg->vni_list. Both cursors are plain ordinals stored in
cb->args[0] and cb->args[1], and RTNL is released between dump skbs.

A concurrent __vxlan_vni_add_list(), which inserts sorted by VNI,
__vxlan_vni_del_list(), or an in-place group update in
vxlan_vni_update() (which splits or merges coalesced VNI ranges) shifts
the second cursor, duplicating or skipping entries. Unregistering a
vxlan device shifts the first one, and the partially dumped device is
then skipped altogether by the "if (idx < s_idx)" test, silently losing
the rest of its VNIs.

Add a per-netns generation counter, bumped whenever the set of vxlan
devices in the netns or any vni_list changes, and feed it to
nl_dump_check_consistent() so that user space gets NLM_F_DUMP_INTR and
can retry, as vxlan_mdb_dump() already does.

The counter is keyed on dev_net(vxlan->dev) rather than vxlan->net,
because the dump enumerates devices with for_each_netdev_rcu() in the
netns the netdevice lives in, which differs from the packet i/o netns
when the device was created with a separate link netns.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260922181102.3989489-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

...

This commit is contained in:

Eric Dumazet 2026-09-22 18:10:57 +00:00 • committed by Jakub Kicinski

parent d10b7b93c5

commit 0e75889596

3 changed files with 42 additions and 6 deletions

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4

drivers/net/vxlan/vxlan_core.c

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9

drivers/net/vxlan/vxlan_private.h

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35

drivers/net/vxlan/vxlan_vnifilter.c

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