GSO/GRO offloads, with TCP+ECN and UDP support

cpupin_other.go

@@ -0,0 +1,11 @@
+//go:build !linux || android || e2e_testing
+
+package nebula
+
+// pinThreadToCPU is a no-op outside Linux: only Linux exposes a stable
+// per-thread CPU affinity API and only Linux has XPS-driven TX ring
+// selection in the first place. On every other platform there's nothing
+// to fix here.
+func pinThreadToCPU(_ int) error {
+	return nil
+}