the hosts.add() method may only be called in vcl_init

src/tests/add.vtc

@@ -18,6 +18,31 @@ varnish v1 -vcl {
 	}
 } -start
 
+varnish v1 -vcl {
+	import hoailona from "${vmod_topbuild}/src/.libs/libvmod_hoailona.so";
+	backend b { .host = "${bad_ip}"; }
+
+	sub vcl_init {
+		new p = hoailona.policy(OPEN, 1h);
+		new h = hoailona.hosts();
+	}
+
+	sub vcl_recv {
+		h.add("example.com", "p");
+        }
+}
+
+client c1 {
+	txreq
+	rxresp
+} -run
+
+logexpect l1 -v v1 -d 1 -g vxid -q "VCL_Error" {
+        expect 0 * Begin req
+        expect * = VCL_Error "^vmod hoailona error: h.add.. may only be called in vcl_init$"
+        expect * = End
+} -run
+
 varnish v1 -errvcl {vmod hoailona error: host is empty in h.add()} {
 	import hoailona from "${vmod_topbuild}/src/.libs/libvmod_hoailona.so";
 	backend b { .host = "${bad_ip}"; }

src/vmod_hoailona.c

@@ -51,6 +51,8 @@
 #define ERRNOMEM(ctx, msg) \
         ERR((ctx), msg ", out of space")
 
+#define INIT(ctx) (((ctx)->method & VCL_MET_INIT) != 0)
+
 #define INIT_FINI(ctx) (((ctx)->method & (VCL_MET_INIT | VCL_MET_FINI)) != 0)
 
 #define ILLEGAL(ctx, m) \
@@ -322,7 +324,6 @@ valid_hostname(VRT_CTX, const char * restrict const hostname)
 	return 1;
 }
 
-/* XXX only legal in init */
 VCL_VOID
 vmod_hosts_add(VRT_CTX, struct vmod_hoailona_hosts *hosts,
 	       struct vmod_priv *init_task, VCL_STRING hostname,
@@ -341,6 +342,11 @@ vmod_hosts_add(VRT_CTX, struct vmod_hoailona_hosts *hosts,
 	CHECK_OBJ_NOTNULL(ctx->ws, WS_MAGIC);
 	CHECK_OBJ_NOTNULL(hosts, VMOD_HOAILONA_HOSTS_MAGIC);
 	AN(init_task);
+	if (!INIT(ctx)) {
+		VERR(ctx, "%s.add() may only be called in vcl_init",
+		     hosts->vcl_name);
+		return;
+	}
 	if (hostname == NULL || hostname[0] == '\0') {
 		VERR(ctx, "host is empty in %s.add()", hosts->vcl_name);
 		return;