Re: [PATCH net] ipv6: no need to return rt->dst.error if it is not null entry.
From: Roopa Prabhu <hidden>
Date: 2017-07-26 19:38:26
On Wed, Jul 26, 2017 at 12:00 PM, David Ahern [off-list ref] wrote:
quoted hunk ↗ jump to hunk
On 7/26/17 12:55 PM, Roopa Prabhu wrote:quoted
On Wed, Jul 26, 2017 at 11:49 AM, David Ahern [off-list ref] wrote:quoted
On 7/26/17 12:27 PM, Roopa Prabhu wrote:quoted
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.yes, exactly. wouldn't 'rt != net->ipv6.ip6_prohibit_entry' above let it fall through to the route fill code ? ah...but i guess you are saying that they will have rt6_info's of their own and will not match. got it. ack.This:diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 4d30c96a819d..24de81c804c2 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c@@ -3637,11 +3637,6 @@ static int inet6_rtm_getroute(struct sk_buff*in_skb, struct nlmsghdr *nlh, dst = ip6_route_lookup(net, &fl6, 0); rt = container_of(dst, struct rt6_info, dst); - if (rt->dst.error) { - err = rt->dst.error; - ip6_rt_put(rt); - goto errout; - } if (rt == net->ipv6.ip6_null_entry) { err = rt->dst.error; Puts back the original behavior. In that case, only rt == null_entry drops to the error path which is correct. All other rt values will drop to rt6_fill_node and return rt data.
yes, i thought so too and hence acked v1. But, following congs comment, realized that it may mask some real errors for fibmatch ? I just tested a case of unreachable route with just the above patch you posted, and I do get the error correctly. so, I guess you are saying all real errors for fibmatch will have "rt == net->ipv6.ip6_null_entry" and we should be ok. sounds good to me.