Messages in this thread | | | Date | Sun, 01 Apr 2012 17:30:32 -0400 (EDT) | Subject | Re: [PATCHv1] ipv6: Fix RTM_GETROUTE's interpretation of RTA_IIF to be consistent with ipv4 | From | David Miller <> |
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From: Shmulik Ladkani <shmulik.ladkani@gmail.com> Date: Sun, 1 Apr 2012 17:03:45 +0300
> In IPv4, if an RTA_IIF attribute is specified within an RTM_GETROUTE > message, then a route is searched as if a packet was received on the > specified 'iif' interface. > > 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. > > Fix 'inet6_rtm_getroute()' so that RTA_IIF is interpreted as "lookup a > route as if a packet was received on the specified interface", similar > to IPv4's 'inet_rtm_getroute()' interpretation. > > Reported-by: Ami Koren <amikoren@yahoo.com> > Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Applied, thanks.
> 1) An alternative: construction of an skb within 'inet6_rtm_getroute()' > and then calling 'ip6_route_input()' with the skb as an argument. > Thus, no need to split common code of 'ip6_route_input()'. > Less elegant IMO.
Agreed.
> 2) Better name for the new common function 'ip6_route_input_lookup()' > Will happily accept any better suggestions.
No, it's fine.
> 3) In IPv4 the 'ip_route_input()' call within 'inet_rtm_getroute()'is > protected by a 'local_bh_disable()' since dawn of history. > Not sure if similar protection needed within 'inet6_rtm_getroute()'.
Since all the code paths are shared more than on the ipv4 side, both output and input route lookups can be done with and without BH disabling.
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