[Fix] Do not check DMARC if SPF or DKIM were not checked

Issue: #1629

src/plugins/dkim_check.c

@@ -870,7 +870,21 @@ dkim_symbol_callback (struct rspamd_task *task, void *unused)
 	GError *err = NULL;
 	struct rspamd_mime_header *rh;
 	struct dkim_check_result *res = NULL, *cur;
-	guint checked = 0, i;
+	guint checked = 0, i, *dmarc_checks;
+
+	/* Allow dmarc */
+	dmarc_checks = rspamd_mempool_get_variable (task->task_pool, "dmarc_checks");
+
+	if (dmarc_checks) {
+		(*dmarc_checks) ++;
+	}
+	else {
+		dmarc_checks = rspamd_mempool_alloc (task->task_pool,
+				sizeof (*dmarc_checks));
+		*dmarc_checks = 1;
+		rspamd_mempool_set_variable (task->task_pool, "dmarc_checks",
+				dmarc_checks, NULL);
+	}
 
 	/* First check if plugin should be enabled */
 	if ((!dkim_module_ctx->check_authed && task->user != NULL)

src/plugins/lua/dmarc.lua

@@ -255,6 +255,12 @@ local function dmarc_callback(task)
   local dmarc_domain, efromdom, spf_domain
   local ip_addr = task:get_ip()
   local dkim_results = {}
+  local dmarc_checks = task:get_mempool():get_variable('dmarc_checks', 'int') or 0
+
+  if dmarc_checks ~= 2 then
+    rspamd_logger.infox(task, "skip DMARC checks as either SPF or DKIM were not checked");
+    return
+  end
 
   if ((not check_authed and task:get_user()) or
       (not check_local and ip_addr and ip_addr:is_local())) then

src/plugins/spf.c

@@ -549,6 +549,21 @@ spf_symbol_callback (struct rspamd_task *task, void *unused)
 	const gchar *domain;
 	struct spf_resolved *l;
 	struct rspamd_async_watcher *w;
+	gint *dmarc_checks;
+
+	/* Allow dmarc */
+	dmarc_checks = rspamd_mempool_get_variable (task->task_pool, "dmarc_checks");
+
+	if (dmarc_checks) {
+		(*dmarc_checks) ++;
+	}
+	else {
+		dmarc_checks = rspamd_mempool_alloc (task->task_pool,
+				sizeof (*dmarc_checks));
+		*dmarc_checks = 1;
+		rspamd_mempool_set_variable (task->task_pool, "dmarc_checks",
+				dmarc_checks, NULL);
+	}
 
 	if (radix_find_compressed_addr (spf_module_ctx->whitelist_ip,
 			task->from_addr) != RADIX_NO_VALUE) {