path: root/arch/alpha/include
diff options
authorMartynas Pumputis <m@lambda.lt>2021-06-23 15:56:45 +0200
committerDavid S. Miller <davem@davemloft.net>2021-06-24 11:13:05 -0700
commite8b9eab99232c4e62ada9d7976c80fd5e8118289 (patch)
tree56384d1ddfde557dc11958b3281eca998b894f24 /arch/alpha/include
parentMerge branch 'devlink-rate-limit-fixes' (diff)
net: retrieve netns cookie via getsocketopt
It's getting more common to run nested container environments for testing cloud software. One of such examples is Kind [1] which runs a Kubernetes cluster in Docker containers on a single host. Each container acts as a Kubernetes node, and thus can run any Pod (aka container) inside the former. This approach simplifies testing a lot, as it eliminates complicated VM setups. Unfortunately, such a setup breaks some functionality when cgroupv2 BPF programs are used for load-balancing. The load-balancer BPF program needs to detect whether a request originates from the host netns or a container netns in order to allow some access, e.g. to a service via a loopback IP address. Typically, the programs detect this by comparing netns cookies with the one of the init ns via a call to bpf_get_netns_cookie(NULL). However, in nested environments the latter cannot be used given the Kubernetes node's netns is outside the init ns. To fix this, we need to pass the Kubernetes node netns cookie to the program in a different way: by extending getsockopt() with a SO_NETNS_COOKIE option, the orchestrator which runs in the Kubernetes node netns can retrieve the cookie and pass it to the program instead. Thus, this is following up on Eric's commit 3d368ab87cf6 ("net: initialize net->net_cookie at netns setup") to allow retrieval via SO_NETNS_COOKIE. This is also in line in how we retrieve socket cookie via SO_COOKIE. [1] https://kind.sigs.k8s.io/ Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Martynas Pumputis <m@lambda.lt> Cc: Eric Dumazet <edumazet@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/alpha/include')
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h
index 57420356ce4c..6b3daba60987 100644
--- a/arch/alpha/include/uapi/asm/socket.h
+++ b/arch/alpha/include/uapi/asm/socket.h
@@ -127,6 +127,8 @@
+#define SO_NETNS_COOKIE 71
#if !defined(__KERNEL__)
#if __BITS_PER_LONG == 64