4 files changed, 23 insertions, 0 deletions
diff --git a/axconfig.c b/axconfig.c
index 9486f5b..c6a2cb0 100644
--- a/axconfig.c
+++ b/axconfig.c
@@ -15,7 +15,9 @@
 #include <netax25/axconfig.h>
 #include <netax25/axlib.h>
 #include <netrose/rose.h>
+
 #include "pathnames.h"
+#include "util.h"
 
 typedef struct _axport
 {
@@ -312,6 +314,8 @@ int ax25_config_load_ports(void)
 			while (isspace(*s & 0xff)) ++s;
 
 			memset(&ifr, 0, sizeof(ifr));
+			if (strlen(s) >= IFNAMSIZ)
+				unreachable();
 			strncpy(ifr.ifr_name, s, IFNAMSIZ-1);
 			ifr.ifr_name[IFNAMSIZ-1] = 0;
 
diff --git a/nrconfig.c b/nrconfig.c
index 003dfb2..18fb6e1 100644
--- a/nrconfig.c
+++ b/nrconfig.c
@@ -18,6 +18,8 @@
 #include <netax25/axlib.h>
 #include <netax25/nrconfig.h>
 
+#include "util.h"
+
 typedef struct _nrport
 {
 	struct _nrport *Next;
@@ -291,6 +293,8 @@ int nr_config_load_ports(void)
 			while (isspace(*s & 0xff)) ++s;
 
 			memset(&ifr, 0, sizeof(ifr));
+			if (strlen(s) >= IFNAMSIZ)
+				unreachable();
 			strncpy(ifr.ifr_name, s, IFNAMSIZ-1);
 			ifr.ifr_name[IFNAMSIZ-1] = 0;
 
diff --git a/rsconfig.c b/rsconfig.c
index 21b91e0..8c7712b 100644
--- a/rsconfig.c
+++ b/rsconfig.c
@@ -18,6 +18,7 @@
 #include <netax25/rsconfig.h>
 
 #include "pathnames.h"
+#include "util.h"
 
 typedef struct _rsport
 {
@@ -237,6 +238,8 @@ int rs_config_load_ports(void)
 			while (isspace(*s & 0xff)) ++s;
 
 			memset(&ifr, 0, sizeof(ifr));
+			if (strlen(s) >= IFNAMSIZ)
+				unreachable();
 			strncpy(ifr.ifr_name, s, IFNAMSIZ-1);
 			ifr.ifr_name[IFNAMSIZ-1] = 0;
 
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..2d2c252
--- /dev/null
+++ b/util.h
@@ -0,0 +1,12 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#ifndef __LIBAX25_UTIL_H
+#define __LIBAX25_UTIL_H
+
+#define unreachable() \
+	do { __builtin_unreachable(); } while (0)
+
+#endif /* __LIBAX25_UTIL_H  */