nf_send_reset6 is not considering the L3 domain and lookups are sent to the wrong table. For example consider the following output rule:
ip6tables -A OUTPUT -p tcp --dport 12345 -j REJECT --reject-with tcp-reset using perf to analyze lookups via the fib6_table_lookup tracepoint shows: swapper 0 [001] 248.787816: fib6:fib6_table_lookup: table 255 oif 0 iif 1 src 2100:1::3 dst 2100:1: ffffffff81439cdc perf_trace_fib6_table_lookup ([kernel.kallsyms]) ffffffff814c1ce3 trace_fib6_table_lookup ([kernel.kallsyms]) ffffffff814c3e89 ip6_pol_route ([kernel.kallsyms]) ffffffff814c40d5 ip6_pol_route_output ([kernel.kallsyms]) ffffffff814e7b6f fib6_rule_action ([kernel.kallsyms]) ffffffff81437f60 fib_rules_lookup ([kernel.kallsyms]) ffffffff814e7c79 fib6_rule_lookup ([kernel.kallsyms]) ffffffff814c2541 ip6_route_output_flags ([kernel.kallsyms]) 528 nf_send_reset6 ([nf_reject_ipv6]) Update nf_send_reset6 to pull the L3 domain from the dst currently attached to the skb. Signed-off-by: David Ahern <d...@cumulusnetworks.com> --- net/ipv6/netfilter/nf_reject_ipv6.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/ipv6/netfilter/nf_reject_ipv6.c b/net/ipv6/netfilter/nf_reject_ipv6.c index a5400223fd74..10090400c72f 100644 --- a/net/ipv6/netfilter/nf_reject_ipv6.c +++ b/net/ipv6/netfilter/nf_reject_ipv6.c @@ -156,6 +156,7 @@ void nf_send_reset6(struct net *net, struct sk_buff *oldskb, int hook) fl6.daddr = oip6h->saddr; fl6.fl6_sport = otcph->dest; fl6.fl6_dport = otcph->source; + fl6.flowi6_oif = l3mdev_master_ifindex(skb_dst(oldskb)->dev); security_skb_classify_flow(oldskb, flowi6_to_flowi(&fl6)); dst = ip6_route_output(net, NULL, &fl6); if (dst->error) { -- 2.1.4