AS number and country looked up for every client (closes #95)

GeoJS's geo.json is asked about every new visitor unless
SWWAF_LOOKUP_SOURCE is off. A request waits for its client's first
answer only while a country list or SWWAF_ADD_LOOKUP_HEADERS needs it;
otherwise the answer reaches the client's history and ban notes when it
comes. The AS number and name go beside the country in the request log,
history, ban notes, alerts and lookups.json, with metrics by AS number;
64512 counts as unknown. A client's own X-Client-ASN and
X-Client-Country never reach the app, whatever the setting says, and
make example-app sends no address to GeoJS.

Judgement call: AS numbers are written AS64496, as SPEC's settings write them.
Judgement call: SWWAF_LOOKUP_TIMEOUT is added, default 1s, and cannot be off.

Model: opus-5-5

internal/proxy/proxy_test.go

@@ -66,6 +66,9 @@ const (
 	rateLimitPerMinute      = "SWWAF_RATE_LIMIT_PER_MINUTE"
 	rateLimitPerDay         = "SWWAF_RATE_LIMIT_PER_DAY"
 	rateLimitExemptPaths    = "SWWAF_RATE_LIMIT_EXEMPT_PATHS"
+	lookupSource            = "SWWAF_LOOKUP_SOURCE"
+	lookupTimeout           = "SWWAF_LOOKUP_TIMEOUT"
+	addLookupHeaders        = "SWWAF_ADD_LOOKUP_HEADERS"
 	deniedCountries         = "SWWAF_DENIED_COUNTRIES"
 	allowedCountries        = "SWWAF_EXCLUSIVELY_ALLOWED_COUNTRIES"
 	banResponse             = "SWWAF_BAN_RESPONSE"
@@ -203,8 +206,8 @@ func startProxy(t *testing.T, appURL string, env map[string]string) (string, *ou
 	return startProxyWithGeoJS(t, appURL, "", env)
 }
 
-// startProxyWithGeoJS is startProxy with clients' countries looked up at
-// geojsURL.
+// startProxyWithGeoJS is startProxy with clients' AS numbers and
+// countries looked up at geojsURL.
 func startProxyWithGeoJS(
 	t *testing.T, appURL, geojsURL string, env map[string]string,
 ) (string, *output) {
@@ -232,17 +235,50 @@ func startProxyWithClock(
 }
 
 // startProxyWithAlerts is startProxyWithClock, and returns the queue of
-// the alerts the proxy raises as well, as the settings in env make it. No
-// alert is sent from it: they wait in it, for the test to look at.
+// the alerts the proxy raises as well, as newProxy makes them.
 func startProxyWithAlerts(
 	t *testing.T, appURL, geojsURL string, now func() time.Time,
 	env map[string]string,
 ) (string, *output, *proxy.Server, *alerts.Queue) {
 	t.Helper()
 
+	server, out, alertQueue := newProxy(t, appURL, geojsURL, now, env)
+
+	listener, err := (&net.ListenConfig{}).Listen(t.Context(), "tcp", localhost+":0")
+	if err != nil {
+		t.Fatalf("listen: %v", err)
+	}
+
+	go func() {
+		_ = server.Serve(listener)
+	}()
+
+	t.Cleanup(func() {
+		_ = server.Close()
+	})
+
+	return listener.Addr().String(), out, server, alertQueue
+}
+
+// newProxy makes the server startProxyWithClock starts, without starting
+// it, and returns it, what it writes, and the queue of the alerts the
+// proxy raises, as the settings in env make it. No alert is sent from the
+// queue: they wait in it, for the test to look at. With no geojsURL, there
+// is no stand-in for GeoJS to look clients up at, and SWWAF_LOOKUP_SOURCE
+// is off unless env sets it.
+func newProxy(
+	t *testing.T, appURL, geojsURL string, now func() time.Time,
+	env map[string]string,
+) (*proxy.Server, *output, *alerts.Queue) {
+	t.Helper()
+
 	settings := map[string]string{
 		"SWWAF_UPSTREAM_URL": appURL, rulesDir: t.TempDir(), instanceName: "app",
 	}
+	if geojsURL == "" {
+		settings[lookupSource] = "off"
+	}
+
 	maps.Copy(settings, env)
 
 	cfg, err := config.FromEnvironment(func(name string) (string, bool) {
@@ -284,20 +320,7 @@ func startProxyWithAlerts(
 		Alerts:     alertQueue,
 	})
 
-	listener, err := (&net.ListenConfig{}).Listen(t.Context(), "tcp", localhost+":0")
-	if err != nil {
-		t.Fatalf("listen: %v", err)
-	}
-
-	go func() {
-		_ = server.Serve(listener)
-	}()
-
-	t.Cleanup(func() {
-		_ = server.Close()
-	})
-
-	return listener.Addr().String(), out, server, alertQueue
+	return server, out, alertQueue
 }
 
 // newClient returns an HTTP client that sends requests as they are made,