Sebastian Andrzej Siewior [off-list ref] writes:

quoted

quoted

+static inline struct bpf_redirect_info *bpf_net_ctx_get_ri(void)
+{
+	struct bpf_net_context *bpf_net_ctx = bpf_net_ctx_get();
+
+	if (!bpf_net_ctx)
+		return NULL;

... do we really need all the NULL checks?

(not just here, but in the code below as well).

I'm a little concerned that we are introducing a bunch of new branches
in the XDP hot path. Which is also why I'm asking for benchmarks :)

We could hide the WARN behind CONFIG_DEBUG_NET. The only purpose is to
see the backtrace where the context is missing. Having just an error
somewhere will make it difficult to track.

The NULL check is to avoid a crash if the context is missing. You could
argue that this should be noticed in development and never hit
production. If so, then we get the backtrace from NULL-pointer
dereference and don't need the checks and WARN.

Yup, this (relying on the NULL deref) SGTM :)

-Toke