1560652 – Failure setting IPv6 token for interface in kernel

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Bug 1560652 - Failure setting IPv6 token for interface in kernel

Summary: Failure setting IPv6 token for interface in kernel

Keywords:
Status:	CLOSED ERRATA
Alias:	None
Product:	Red Hat Enterprise Linux 7
Classification:	Red Hat
Component:	NetworkManager
Sub Component:
Version:	7.5
Hardware:	Unspecified
OS:	Unspecified
Priority:	high
Severity:	high
Target Milestone:	rc
Target Release:	---
Assignee:	Beniamino Galvani
QA Contact:	Desktop QE
Docs Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+	depends on / blocked

Reported:	2018-03-26 16:16 UTC by Thomas Haller
Modified:	2019-08-06 13:16 UTC (History)
CC List:	10 users (show)
Fixed In Version:	NetworkManager-1.16.2-0.1.20190328git8ec0954570.el7
Doc Type:	If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed:	2019-08-06 13:16:20 UTC
Target Upstream Version:
Embargoed:

Attachments	(Terms of Use)

Links
System	ID	Private	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHBA-2019:2302	0	None	None	None	2019-08-06 13:16:36 UTC

Description Thomas Haller 2018-03-26 16:16:09 UTC

When configuring ipv6.token in NetworkManager, the token seems to be correctly used to generate addresses (in user-space).

However, NM also tries to set the token of the link via netlink:


platform-linux: link: change 3: token: set IPv6 address generation token to ::2


that always fails with:

<warn>  [1522080519.8317] platform-linux: do-change-link[3]: failure changing link: failure 22 (Invalid argument)



Probably, related to kernel doing:



static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token)
...
»·······if (!token)
»·······»·······return -EINVAL;
»·······if (dev->flags & (IFF_LOOPBACK | IFF_NOARP))
»·······»·······return -EINVAL;
»·······if (!ipv6_accept_ra(idev))
»·······»·······return -EINVAL;
»·······if (idev->cnf.rtr_solicits == 0)
»·······»·······return -EINVAL;

note !ipv6_accept_ra(), which NM disables.


Maybe, NM shouldn't try to set the token in kernel. Or maybe kernel is wrong to reject this command. Either way, something is wrong.


I however does not seem harmful, beside the confusing logging message.

Comment 2 Beniamino Galvani 2018-06-08 13:50:22 UTC

(In reply to Thomas Haller from comment #0)
> When configuring ipv6.token in NetworkManager, the token seems to be
> correctly used to generate addresses (in user-space).
> 
> However, NM also tries to set the token of the link via netlink:
> 
> 
> platform-linux: link: change 3: token: set IPv6 address generation token to
> ::2
> 
> that always fails with:
> 
> <warn>  [1522080519.8317] platform-linux: do-change-link[3]: failure
> changing link: failure 22 (Invalid argument)

Do you have a reproducer for this? It seem to be working without errors for me.


> Probably, related to kernel doing:
> 
> static int inet6_set_iftoken(struct inet6_dev *idev, struct in6_addr *token)
> ...
> »·······if (!token)
> »·······»·······return -EINVAL;
> »·······if (dev->flags & (IFF_LOOPBACK | IFF_NOARP))
> »·······»·······return -EINVAL;
> »·······if (!ipv6_accept_ra(idev))
> »·······»·······return -EINVAL;
> »·······if (idev->cnf.rtr_solicits == 0)
> »·······»·······return -EINVAL;
> 
> note !ipv6_accept_ra(), which NM disables.

Actually, we enable accept_ra so it must be something else:

 case NM_NDISC_NODE_TYPE_HOST:
	/* Accepting prefixes from discovered routers. */
	nm_device_ipv6_sysctl_set (self, "accept_ra", "1");
	nm_device_ipv6_sysctl_set (self, "accept_ra_defrtr", "0");
	nm_device_ipv6_sysctl_set (self, "accept_ra_pinfo", "0");
	nm_device_ipv6_sysctl_set (self, "accept_ra_rtr_pref", "0");

Comment 3 Thomas Haller 2018-09-25 14:56:06 UTC

Unfortunately, I did not see it since.

Thanks for looking into this. Maybe let's close it as INCOMPLETE?

Comment 4 Beniamino Galvani 2018-09-27 15:26:13 UTC

(In reply to Thomas Haller from comment #0)
> When configuring ipv6.token in NetworkManager, the token seems to be
> correctly used to generate addresses (in user-space).
> 
> However, NM also tries to set the token of the link via netlink:
> 
> 
> platform-linux: link: change 3: token: set IPv6 address generation token to
> ::2
> 
> 
> that always fails with:
> 
> <warn>  [1522080519.8317] platform-linux: do-change-link[3]: failure
> changing link: failure 22 (Invalid argument)

> Maybe, NM shouldn't try to set the token in kernel. Or maybe kernel is wrong
> to reject this command. Either way, something is wrong.

I think it's useful to set the token in the kernel so that it's visible with 'ip token'.

The problem was that we tried to set the token when 'accept_ra' was still 0. This is fixed now:

https://cgit.freedesktop.org/NetworkManager/NetworkManager/commit/?id=6b5790a05e28d7d896968e43645e86ade2e967f6

Comment 8 errata-xmlrpc 2019-08-06 13:16:20 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2019:2302

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