TUN-6604: Trace icmp echo request on Linux and Darwin

tracing/tracing.go

@@ -189,6 +189,10 @@ func (cft *cfdTracer) AddSpans(headers http.Header) {
 	headers[CanonicalCloudflaredTracingHeader] = []string{enc}
 }
 
+func (cft *cfdTracer) ClearSpans() {
+	cft.exporter.ClearSpans()
+}
+
 // End will set the OK status for the span and then end it.
 func End(span trace.Span) {
 	endSpan(span, -1, codes.Ok, nil)
@@ -246,7 +250,6 @@ func extractTraceFromString(ctx context.Context, trace string) (context.Context,
 		parts[0] = strings.Repeat("0", left) + parts[0]
 		trace = strings.Join(parts, separator)
 	}
-
 	// Override the 'cf-trace-id' as 'uber-trace-id' so the jaeger propagator can extract it.
 	traceHeader := map[string]string{TracerContextNameOverride: trace}
 	remoteCtx := otel.GetTextMapPropagator().Extract(ctx, propagation.MapCarrier(traceHeader))
@@ -277,6 +280,11 @@ func extractTrace(req *http.Request) (context.Context, bool) {
 	if traceHeader[TracerContextNameOverride] == "" {
 		return nil, false
 	}
+
 	remoteCtx := otel.GetTextMapPropagator().Extract(req.Context(), propagation.MapCarrier(traceHeader))
 	return remoteCtx, true
 }
+
+func NewNoopSpan() trace.Span {
+	return trace.SpanFromContext(nil)
+}