egressgw: Redirect from bpf_overlay to egress gw SNAT netdev #29379
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This commit fixes the problem that an iptables SNAT rule in the host netns interferes with packets to egress gw by redirecting from bpf_overlay. Fixes: cilium#17848 Signed-off-by: Yusuke Suzuki <yusuke.suzuki@isovalent.com>
…hook So that we can remove the duplicate check in nat.h and bpf_overlay.h Signed-off-by: Yusuke Suzuki <yusuke.suzuki@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture, and also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture, and also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (cilium#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. cilium#29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. #29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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[ upstream commit cf6b203 ] To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. #29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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[ upstream commit cf6b203 ] To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. #29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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[ upstream commit cf6b203 ] To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. #29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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[ upstream commit cf6b203 ] To let EGW traffic exit the gateway through the correct interface, we've introduced FIB lookup-driven redirects in the to-netdev path (#26215). This is needed for cases where the traffic first hits one interface via the default route, but then needs to bounce to some other interface that matches the actual egressIP. In this approach we masquerade the packet on its first pass through to-netdev, set the SNAT_DONE mark, and then redirect to the actual egress interface. Due to the SNAT_DONE mark we then skip the SNAT logic in the second pass through to-netdev. #29379 then improved the situation for any EGW traffic that enters the gateway from the overlay network (== anything that's not by a pod on the gateway). We now redirect in from-overlay, straight to the actual egress interface and masquerade the packet there. Now also harmonize the approach for local pods, and defer the masquerade until the packet hits the actual egress interface. This simplifies the overall picture. But it also allows us to raise TO_NETWORK datapath trace events that are enriched with the packet's original source IP - this event is raised on the *second* pass through to-netdev, so we need the SNAT to happen at the same time. Also add a comment to clarify the check to skip HostFW for SNATed traffic. Signed-off-by: Julian Wiedmann <jwi@isovalent.com>
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This PR fixes the problem that an iptables SNAT rule in the host netns interferes with packets to egress gw by redirecting from bpf_overlay.
Fixes: #17848