From 41d03fa15850dbadd4d499cc440a2dd2fee23a72 Mon Sep 17 00:00:00 2001
From: Michael Krieger <phyre@phyre.me>
Date: Thu, 5 Mar 2020 18:02:43 -0500
Subject: [PATCH] Update functions.inc.php

---
 functions.inc.php | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/functions.inc.php b/functions.inc.php
index 70c6c49e..b2157ca1 100644
--- a/functions.inc.php
+++ b/functions.inc.php
@@ -260,6 +260,33 @@ function check_domain($domain) {
     return '';
 }
 
+/**
+ * Checks if a domain is local
+ * @param string $domain
+ * @return string empty if the domain is valid, otherwise string with the errormessage
+ */
+function check_localaliasonly($domain) {
+    // If emailcheck_localonly_domain is set to 'YES', disallow aliases to remote servers (but allow aliases on this server)
+    if (Config::bool('emailcheck_localaliasonly')) {
+        // get the domain part of the e-mail
+        list(/*NULL*/, $domain) = explode('@', $domain);
+        
+        // get all domains managed on this system by postfixadmin
+        $domains = list_domains();
+        
+        // Only allow local domains to be alias destinations
+        if (in_array($domain, $domains)) {
+            return '';
+        } else {
+            // FIXME: Add transaltions
+            return sprintf("You may only make aliases to domains hosted on this server. %s is a remote domain name.", htmlentities($domain));
+        }
+    } else {
+      return '';
+    }
+
+}
+
 /**
  * Get password expiration value for a domain
  * @param string $domain - a string that may be a domain