[v1.14] bpf: avoid SNAT tracking for overlay traffic #31797
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[ upstream commit 3e32efc ] [ backporter's notes: the tests looked a bit different in v1.14 ] This is an internal macro that's selected by common.h (based on TUNNEL_MODE and a few other config options). There should be no need to explicitly set it. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
[ upstream commit 5b37dc9 ] [ backporter's notes: minor conflicts due to changed context ] When a packet gets SNATed in to-overlay, there is no point in setting the SNAT-done mark. Firstly the mark refers to the *inner* packet, but all subsequent users will only see the outer headers. Also our own netfilter rules installed by installHostTrafficMarkRule() currently clear the mark for overlay traffic. Free up the mark for future usage. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
[ upstream commit 2860ded ] [ backporter's notes: minor conflict in bpf_overlay, as handle_nat_fwd() didn't have the trace_ctx / ext_err parameters ] To make smarter decisions at the native-device level (in to-netdev), mark traffic that is created by cilium's overlay interface. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
[ upstream commit 7c789e5 ] Creating SNAT entries for our own overlay traffic makes little sense. In particular as the replies will not be addressed to the egressing packet's source port, but to TUNNEL_PORT. Avoiding such SNAT tracking reduces the pressure on the CT and NAT maps. Fixes: cilium#26908 Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
[ upstream commit b523a92 ] Prior to 2860ded ("datapath: mark to-overlay traffic"), overlay traffic would reach the HostFW egress path in to-netdev with MARK_MAGIC_HOST set. Restore this behaviour by also assigning HOST_ID for traffic that has MARK_MAGIC_OVERLAY set. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
[ upstream commit 8984c20 ] As we now have a mark-derived src_sec_identity available, we might as well share this bit of information with the user. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
[ upstream commit e984f65 ] The blamed commit attempted to remove all usage of MARK_MAGIC_SNAT_DONE inside to-overlay, so that we can use MARK_MAGIC_OVERLAY instead. But it accidentally also touched the LB's NAT-egress path (which is used by from-overlay to forward LB'ed requests to the egress path, on their way to a remote backend). Here we need to maintain the usage of MARK_MAGIC_SNAT_DONE, so that the egress program (either to-overlay or to-netdev) doesn't apply a second SNAT operation. Otherwise the LB node is unable to properly RevNAT the reply traffic. Fix this by restoring the code that sets the MARK_MAGIC_SNAT_DONE flag for traffic in from-overlay. When such a request is forwarded to the overlay interface, then to-overlay will consume the mark, override it with MARK_MAGIC_OVERLAY and skip the additional SNAT step. Fixes: 5b37dc9 ("bpf: nodeport: avoid setting SNAT-done mark for to-overlay") Reported-by: Marco Iorio <marco.iorio@isovalent.com> Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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