+/*************************************************
+* Wrappers for logging lookup times *
+*************************************************/
+
+/* When the 'slow_lookup_log' variable is enabled, these wrappers will
+write to the log file all (potential) dns lookups that take more than
+slow_lookup_log milliseconds
+*/
+
+static void
+log_long_lookup(const uschar * type, const uschar * data, unsigned long msec)
+{
+log_write(0, LOG_MAIN, "Long %s lookup for '%s': %lu msec",
+ type, data, msec);
+}
+
+
+/* returns the current system epoch time in milliseconds. */
+static unsigned long
+get_time_in_ms()
+{
+struct timeval tmp_time;
+unsigned long seconds, microseconds;
+
+gettimeofday(&tmp_time, NULL);
+seconds = (unsigned long) tmp_time.tv_sec;
+microseconds = (unsigned long) tmp_time.tv_usec;
+return seconds*1000 + microseconds/1000;
+}
+
+
+static int
+dns_lookup_timerwrap(dns_answer *dnsa, const uschar *name, int type,
+ const uschar **fully_qualified_name)
+{
+int retval;
+unsigned long time_msec;
+
+if (!slow_lookup_log)
+ return dns_lookup(dnsa, name, type, fully_qualified_name);
+
+time_msec = get_time_in_ms();
+retval = dns_lookup(dnsa, name, type, fully_qualified_name);
+if ((time_msec = get_time_in_ms() - time_msec) > slow_lookup_log)
+ log_long_lookup(US"name", name, time_msec);
+return retval;
+}