Thx for the reference, exactly what i want, Will change the solution~
Thanks, Alex Wang, On Fri, Jun 5, 2015 at 8:24 AM, Ben Pfaff <b...@nicira.com> wrote: > On Wed, Jun 03, 2015 at 11:21:50PM -0700, Alex Wang wrote: > > OVS datapath has check which prevents the installation of flow > > that matches VLAN TCI but does not have exact match for VLAN_CFI > > bit. However, the ovs userspace does not enforce it, so OpenFlow > > flow like "vlan_tci=0x000a/0x0fff,action=output:local" can be added > > to ovs. Subsequently, the generated megaflow will have match > > field for vlan like "vlan(vid=5/0xfff,pcp=0/0x0,cfi=1/0)". > > > > With the OVS datapath check, the installation of such megaflow > > will be rejected with: > > "|WARN|system@ovs-system: failed to put[create][modify] (Invalid > argument)" > > > > This commit adds a check in userspace that mark the vlan mask > > invalid if it does not exact match for VLAN_CFI. So users will > > be asked to provide correct mask. > > This is not the right fix, because it is legitimate and useful not to > match on the "CFI" (actually "vlan present") bit in OpenFlow. See the > comment in meta-flow.h: > > /* "vlan_tci". > * > * 802.1Q TCI. > * > * For a packet with an 802.1Q header, this is the Tag Control > Information > * (TCI) field, with the CFI bit forced to 1. For a packet with no > 802.1Q > * header, this has value 0. > * > * This field can be used in various ways: > * > * - If it is not constrained at all, the nx_match matches packets > * without an 802.1Q header or with an 802.1Q header that has any > TCI > * value. > * > * - Testing for an exact match with 0 matches only packets without > an > * 802.1Q header. > * > * - Testing for an exact match with a TCI value with CFI=1 matches > * packets that have an 802.1Q header with a specified VID and PCP. > * > * - Testing for an exact match with a nonzero TCI value with CFI=0 > does > * not make sense. The switch may reject this combination. > * > * - Testing with a specific VID and CFI=1, with nxm_mask=0x1fff, > matches > * packets that have an 802.1Q header with that VID (and any PCP). > * > * - Testing with a specific PCP and CFI=1, with nxm_mask=0xf000, > matches > * packets that have an 802.1Q header with that PCP (and any VID). > * > * - Testing with nxm_value=0, nxm_mask=0x0fff matches packets with > no > * 802.1Q header or with an 802.1Q header with a VID of 0. > * > * - Testing with nxm_value=0, nxm_mask=0xe000 matches packets with > no > * 802.1Q header or with an 802.1Q header with a PCP of 0. > * > * - Testing with nxm_value=0, nxm_mask=0xefff matches packets with > no > * 802.1Q header or with an 802.1Q header with both VID and PCP of > 0. > * > * Type: be16. > * Maskable: bitwise. > * Formatting: hexadecimal. > * Prerequisites: none. > * Access: read/write. > * NXM: NXM_OF_VLAN_TCI(4) since v1.1. > * OXM: none. > * OF1.0: exact match. > * OF1.1: exact match. > */ > MFF_VLAN_TCI, > > I think that we should fix this in flow translation, by "unwildcarding" > the CFI bit if any other bits in vlan_tci are unwildcarded. > _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
