Bug 201071

Summary:	Creating a vxlan in state 'up' does not give proper RTM_NEWLINK message
Product:	Networking	Reporter:	liam.mcbirnie
Component:	Other	Assignee:	Stephen Hemminger (stephen)
Status:	NEW ---
Severity:	normal	CC:	roopa
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	4.19-rc1	Subsystem:
Regression:	Yes	Bisected commit-id:
Attachments:	patch to fix notification on newlink with IFF_UP

Description liam.mcbirnie 2018-09-10 04:04:37 UTC

If a vxlan is created with state 'up', the RTM_NEWLINK message shows the state as down, and there no other netlink messages are sent.
As a result, processes listening to netlink are never notified that the vxlan link is up.

eg.
# ip link add test up type vxlan id 8 group 224.224.224.224 dev eth0

Output of ip monitor link
# 4: test: <BROADCAST,MULTICAST> mtu 1450 qdisc noop state DOWN group default
      link/ether ee:cd:97:1a:cf:91 brd ff:ff:ff:ff:ff:ff

Output of ip link show (expected from netlink message)
# 4: test: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN group default qlen 1000
      link/ether ee:cd:97:1a:cf:91 brd ff:ff:ff:ff:ff:ff

This is a regression introduced by the following patch series.
https://patchwork.ozlabs.org/patch/947181/

Comment 1 Roopa Prabhu 2018-09-12 04:44:38 UTC

Created attachment 278465 [details]
patch to fix notification on newlink with IFF_UP

Can you please try the attached patch ?. thank you.

Comment 2 liam.mcbirnie 2018-09-12 07:57:39 UTC

Your patch works.
Thanks.