On 9/26/16 11:02 AM, Jiri Benc wrote: > On Mon, 26 Sep 2016 17:56:22 +0200, Jiri Benc wrote: >> After push_mpls, network_header points to the start of MPLS headers. >> Which I understand was the point of this patch. However, push_mpls also >> calls invalidate_flow_key. Meaning that, depending on actions, we may >> end up calling key_extract soon after. And key_extract sets the network >> header *after* the MPLS headers.
you know this code better than me, but key_extract pulls the eth header and then sets network header. If MPLS labels are present then it is the labels that the network_header now points to. How did come to the conclusion it is after the labels? >> >> That means that on output, for otherwise identical packet, >> network_header can point before or after MPLS headers based on what >> actions happened to be executed (recirculation, mainly). >> >> If I'm not misreading the code or missing something, this can't be >> right. >> >> mpls_gso_segment does not care, it resets the network_header anyway. >> What about drivers? What is the correct behavior? > > Answering to myself: it breaks skb_mac_gso_segment. Seems we need to > fix key_extract to set network_header to the beginning of MPLS headers. > I'll prepare a patch. > > Jiri >
