Messages in this thread | | | Date | Mon, 14 Mar 2022 20:33:09 +0200 | Subject | Re: [PATCH net-next v2] net: openvswitch: fix uAPI incompatibility with existing user space | From | Roi Dayan <> |
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On 2022-03-10 8:44 PM, Aaron Conole wrote: > Ilya Maximets <i.maximets@ovn.org> writes: > >> Few years ago OVS user space made a strange choice in the commit [1] >> to define types only valid for the user space inside the copy of a >> kernel uAPI header. '#ifndef __KERNEL__' and another attribute was >> added later. >> >> This leads to the inevitable clash between user space and kernel types >> when the kernel uAPI is extended. The issue was unveiled with the >> addition of a new type for IPv6 extension header in kernel uAPI. >> >> When kernel provides the OVS_KEY_ATTR_IPV6_EXTHDRS attribute to the >> older user space application, application tries to parse it as >> OVS_KEY_ATTR_PACKET_TYPE and discards the whole netlink message as >> malformed. Since OVS_KEY_ATTR_IPV6_EXTHDRS is supplied along with >> every IPv6 packet that goes to the user space, IPv6 support is fully >> broken. >> >> Fixing that by bringing these user space attributes to the kernel >> uAPI to avoid the clash. Strictly speaking this is not the problem >> of the kernel uAPI, but changing it is the only way to avoid breakage >> of the older user space applications at this point. >> >> These 2 types are explicitly rejected now since they should not be >> passed to the kernel. Additionally, OVS_KEY_ATTR_TUNNEL_INFO moved >> out from the '#ifdef __KERNEL__' as there is no good reason to hide >> it from the userspace. And it's also explicitly rejected now, because >> it's for in-kernel use only. >> >> Comments with warnings were added to avoid the problem coming back. >> >> (1 << type) converted to (1ULL << type) to avoid integer overflow on >> OVS_KEY_ATTR_IPV6_EXTHDRS, since it equals 32 now. >> >> [1] beb75a40fdc2 ("userspace: Switching of L3 packets in L2 pipeline") >> >> Fixes: 28a3f0601727 ("net: openvswitch: IPv6: Add IPv6 extension header support") >> Link: https://lore.kernel.org/netdev/3adf00c7-fe65-3ef4-b6d7-6d8a0cad8a5f@nvidia.com >> Link: https://github.com/openvswitch/ovs/commit/beb75a40fdc295bfd6521b0068b4cd12f6de507c >> Reported-by: Roi Dayan <roid@nvidia.com> >> Signed-off-by: Ilya Maximets <i.maximets@ovn.org> >> --- > > Acked-by: Aaron Conole <aconole@redhat.com> >
I got to check traffic with the fix and I do get some traffic but something is broken. I didn't investigate much but the quick test shows me rules are not offloaded and dumping ovs rules gives error like this
recirc_id(0),in_port(enp8s0f0_1),ct_state(-trk),eth(),eth_type(0x86dd),ipv6(frag=no)(bad key length 2, expected -1)(00 00/(bad mask length 2, expected -1)(00 00), packets:2453, bytes:211594, used:0.004s, flags:S., actions:ct,recirc(0x2)
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