[Q] ipv6: RTM_GETROUTE interpretation of RTA_IIF

Hi,

In IPv4, if the RTA_IIF attribute is specified in an RTM_GETROUTE
message, then a route is searched as if a packet was received on the
specified iif interface - i.e. 'inet_rtm_getroute()' calls
'ip_route_input()'.

However in IPv6, RTA_IIF is not interpreted in the same way:
'inet6_rtm_getroute()' always calls 'ip6_route_output()', regardless the
RTA_IIF attribute.

As a result, in IPv6 there's no way to use RTM_GETROUTE in order to look
for a route as if a packet was received on a specific interface.

I'd like to modify 'inet6_rtm_getroute()' so that RTA_IIF is interpreted
in the same way as in IPv4's 'inet_rtm_getroute()'.

Before I come up with a patch, I'd like to know whether current
interpretation of RTA_IIF in 'inet6_rtm_getroute()' is deliberate.

Regards,
Shmulik

(Bump)

Any reason not to submit a patch that fixes the below issue?

Regards,
Shmulik

On Thu, 29 Mar 2012 15:03:11 +0200 Shmulik Ladkani [off-list ref] wrote:

Hi,

In IPv4, if the RTA_IIF attribute is specified in an RTM_GETROUTE
message, then a route is searched as if a packet was received on the
specified iif interface - i.e. 'inet_rtm_getroute()' calls
'ip_route_input()'.

However in IPv6, RTA_IIF is not interpreted in the same way:
'inet6_rtm_getroute()' always calls 'ip6_route_output()', regardless the
RTA_IIF attribute.

As a result, in IPv6 there's no way to use RTM_GETROUTE in order to look
for a route as if a packet was received on a specific interface.

I'd like to modify 'inet6_rtm_getroute()' so that RTA_IIF is interpreted
in the same way as in IPv4's 'inet_rtm_getroute()'.

Before I come up with a patch, I'd like to know whether current
interpretation of RTA_IIF in 'inet6_rtm_getroute()' is deliberate.

On Sun, 2012-04-01 at 09:18 +0300, Shmulik Ladkani wrote:

(Bump)

Any reason not to submit a patch that fixes the below issue?

Hi Shmulik

No reason I can think about. Are you planning to provide this yourself ?

On Sun, 01 Apr 2012 09:03:59 +0200 Eric Dumazet [off-list ref] wrote:

On Sun, 2012-04-01 at 09:18 +0300, Shmulik Ladkani wrote:

quoted

(Bump)

Any reason not to submit a patch that fixes the below issue?

Hi Shmulik

No reason I can think about. Are you planning to provide this yourself ?

Yes.

Just wanted to make sure ipv6's RTA_IIF interpretation is not deliberate.

Regards,
Shmulik