added --disable-syslog command line option

src/fdns/fdns.h

@@ -277,6 +277,7 @@ extern int arg_log_timeout;
 extern char *arg_fallback_server;
 extern char *arg_unlist;
 extern int arg_clean_filters;
+extern int arg_disable_syslog;
 extern int env_admin_down;
 extern Stats stats;
 

src/fdns/frontend.c

@@ -146,6 +146,8 @@ static int sandbox(void *sandbox_arg) {
 		a[last++] = "--allow-all-queries";
 	if (arg_disable_local_doh)
 		a[last++] = "--disable-local-doh";
+	if (arg_disable_syslog)
+		a[last++] = "--disable-syslog";
 
 	if (arg_cache_ttl != CACHE_TTL_DEFAULT) {
 		char *cmd;

src/fdns/log.c

@@ -62,9 +62,11 @@ void logprintf(const char *format, ...) {
 	va_start(valist, format);
 
 	if (arg_daemonize) {
-		openlog("fdns", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
-		vsyslog(LOG_INFO, format, valist);
-		closelog();
+		if (!arg_disable_syslog) {
+			openlog("fdns", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);
+			vsyslog(LOG_INFO, format, valist);
+			closelog();
+		}
 	}
 	else {
 		// print on stdout

src/fdns/main.c

@@ -54,8 +54,10 @@ int arg_log_timeout = 0;
 char *arg_fallback_server = NULL;
 char *arg_unlist = NULL;
 int arg_clean_filters = 0;
+int arg_disable_syslog = 0;
 int env_admin_down = 0;
 
+
 Stats stats;
 
 // clear /run/fdns/#pid# file
@@ -107,6 +109,7 @@ static void usage(void) {
 	       "\tprinted on the screen during the testing phase.\n");
 	printf("    --disable-local-doh - blocklist DoH services for applications running on\n"
 	       "\tlocal network.\n");
+	printf("    --disable-syslog - disable system logging\n");
 	printf("    --fallback-server=address - fallback server IP address.\n");
 	printf("    --forwarder=domain@address - conditional forwarding to a different DNS\n"
 	       "\tserver.\n");
@@ -199,6 +202,8 @@ int main(int argc, char **argv) {
 				arg_debug_transport = 1;
 			else if (strcmp(argv[i], "--debug-ssl") == 0)
 				arg_debug_ssl = 1;
+			else if (strcmp(argv[i], "--disable-syslog") == 0)
+				arg_disable_syslog = 1;
 			else if (strncmp(argv[i], "--keepalive=", 12) == 0) {
 				arg_keepalive = atoi(argv[i] + 12);
 				if (arg_keepalive < CONFIG_KEEPALIVE_MIN || arg_keepalive > CONFIG_KEEPALIVE_MAX) {

src/man/fdns.txt

@@ -114,6 +114,9 @@ Disable DoH services for applications running on the local network.
 NOTE: Applications can still use an external DoH server if they have a hardcoded IP-Address.
 If you realy want to block other DoH connection you must use your firewall.
 .TP
+\fB\-\-disable-syslog
+Disable system logging.
+.TP
 \fB\-\-forwarder=domain@address
 Conditional domain forwarding to a different DNS server.
 .br