On Wed, Sep 13, 2017 at 2:59 PM, Simon Horman <simon.hor...@netronome.com> wrote: > On Wed, Sep 13, 2017 at 01:03:43PM +0300, Or Gerlitz wrote: >> On Wed, Sep 13, 2017 at 12:25 PM, Simon Horman >> <simon.hor...@netronome.com> wrote: >> > On Tue, Sep 12, 2017 at 11:23:55PM +0300, Or Gerlitz wrote: >> >> On Tue, Sep 12, 2017 at 5:20 PM, Simon Horman >> >> <simon.hor...@netronome.com> wrote: >> >> > Allow matching on options in tunnel headers. >> >> > This makes use of existing tunnel metadata support. >> >> >> >> Simon, >> >> >> >> This patch is about matching on tunnel options, right? but >> >> >> >> > Options are a bytestring of up to 256 bytes. >> >> > Tunnel implementations may support less or more options, >> >> > or no options at all. >> >> > >> >> > # ip link add name geneve0 type geneve dstport 0 external >> >> > # tc qdisc add dev eth0 ingress >> >> > # tc qdisc del dev eth0 ingress; tc qdisc add dev eth0 ingress >> >> > # tc filter add dev eth0 protocol ip parent ffff: \ >> >> > flower indev eth0 \ >> >> > ip_proto udp \ >> >> > action tunnel_key \ >> >> > set src_ip 10.0.99.192 \ >> >> > dst_ip 10.0.99.193 \ >> >> > dst_port 4789 \ >> >> > id 11 \ >> >> > opts 0102800100800022 \ >> >> > action mirred egress redirect dev geneve0 >> >> >> >> the example here is on how to use tunnel options in the tunnel set key >> >> actions.. >> >> >> >> And the other way around in the other patch... the patch is about the >> >> tunnel key set action and the example shows how to match that in >> >> flower... I guess you want to swap the relevant of the change log. >> > >> > Yes, it seems so. Sorry about that. >> >> no worries, you can do the swap, but before that >> >> >> Anyway, is there any human readable/understandable representation of >> >> these options? e.g what does 0102800100800022 means for geneve? >> >> > Thanks, I had not thought of that. My feeling is that could >> > be added to the tc tool as follow-up work. >> >> could you spend few words on the nature of these options now when we review >> the kernel patches? I guess this is somehow related to protocols such >> as geneve and vxlan-gpe -- it would be good if you elaborate on that >> a bit, does >> the kernel does any usage with these options beyond matching on them or >> stiching >> them to packet headers? > > This feature is to be used in conjunction with tunnels in collect metadata > (external) mode. As I understand it there are three tunnel netdevs that use > options metadata in the kernel at this time. > > * Geneve > > In the case of Geneve options are TLVs[1]. My reading is that in collect > metadata mode the kernel does not appear to do anything other than pass > them around as a bytestring. > > [1] https://tools.ietf.org/html/draft-ietf-nvo3-geneve-05#section-3.5 > > * VXLAN-GBP > > In the case of VXLAN-GBP on RX in collect metadata mode options are used > to carry information parsed in vxlan_parse_gbp_hdr() from the VXLAN Group > Based Policy Extension[2]. On RX the options data is used to create an > extension (header) by vxlan_build_gbp_hdr(). > > [2] > https://tools.ietf.org/html/draft-smith-vxlan-group-policy-03#section-2.1 > > * ERSPAN (GRE) > > In the case of ERSPAN, which is a variant of GRE, on RX in collect > metadata mode options are used to carry the index parsed from the ERSPAN > Type II feature header[3] in erspan_rcv(). The converse is true on TX > and is handled by erspan_fb_xmit(). > > [3] https://tools.ietf.org/html/draft-foschiano-erspan-03#section-4.2 > > Users of options: > > * There are eBPF hooks to allow getting on and setting tunnel metadata: > bpf_skb_set_tunnel_opt, bpf_skb_get_tunnel_opt. > > * Open vSwitch is able to match and set Geneve and VXLAN-GBP options. > > Neither of the above appear to assume any structure for the data. > > I hope the above is the kind of information you are after.
yeah, this helps, do we expect HW offloads to be able to work with these options? e.g place/match on packets or even do something beyond that?
