On 7/27/17 10:56 PM, Cong Wang wrote: > On Wed, Jul 26, 2017 at 11:49 AM, David Ahern <dsah...@gmail.com> wrote: >> On 7/26/17 12:27 PM, Roopa Prabhu wrote: >>> agreed...so looks like the check in v3 should be >>> >>> >>> + if ( rt == net->ipv6.ip6_null_entry || >>> + (rt->dst.error && >>> + #ifdef CONFIG_IPV6_MULTIPLE_TABLES >>> + rt != net->ipv6.ip6_prohibit_entry && >>> + rt != net->ipv6.ip6_blk_hole_entry && >>> +#endif >>> + )) { >>> err = rt->dst.error; >>> ip6_rt_put(rt); >>> goto errout; >>> >> >> I don't think so. If I add a prohibit route and use the fibmatch >> attribute, I want to see the route from the FIB that was matched. > > But net->ipv6.ip6_prohibit_entry is not the prohibit route you can > add in user-space, it is only used by rule actions. So do you really > want to dump it?? My gut feeling is no, but I am definitely not sure. > > When you add a prohibit route, a new rt is allocated dynamically, > net->ipv6.ip6_prohibit_entry is relatively static, internal and is the > only one per netns. (Same for net->ipv6.ip6_blk_hole_entry) > > I think Hangbin's example doesn't have ip rules, so this case > is not shown up. >
Understood. The v4 patch returns getroute to the original behavior. The original behavior returned a route entry not just an error code. The following is at 5dafc87f40d7 which the commit before roopa's patch set: # ip -6 ru add to 6000::/120 prohibit # ip -6 ro get 6000::1 prohibit 6000::1 from :: dev lo proto kernel src 2001:db8::3 metric 4294967295 error -13 pref medium # ip -6 ro add vrf red prohibit 5000::1/120 # ip -6 ro get vrf red 5000::1 prohibit 5000::1 from :: dev lo table red src 2001:db8::3 metric 1024 error -13 pref medium Generically, the only time you get just an error response is when the lookup fails to find a match and returns the null_entry which has dst.error = -ENETUNREACH. Now to your point about the new fibmatch option I have gone back and forth but in the end I think returning the route associated with the FIB rule is better than just failing with an error code. Roopa?