extensions: const annotations

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>

1 files changed, 3 insertions, 3 deletions

diff --git a/extensions/libxt_tcp.c b/extensions/libxt_tcp.c
index d9bcbd0e..4d914e39 100644
--- a/extensions/libxt_tcp.c
+++ b/extensions/libxt_tcp.c
@@ -208,10 +208,10 @@ tcp_parse(int c, char **argv, int invert, unsigned int *flags,
 	return 1;
 }
 
-static char *
+static const char *
 port_to_service(int port)
 {
-	struct servent *service;
+	const struct servent *service;
 
 	if ((service = getservbyport(htons(port), "tcp")))
 		return service->s_name;
@@ -222,7 +222,7 @@ port_to_service(int port)
 static void
 print_port(uint16_t port, int numeric)
 {
-	char *service;
+	const char *service;
 
 	if (numeric || (service = port_to_service(port)) == NULL)
 		printf("%u", port);