zebra: fix compilation with GCC14

Fixes:
zebra/zebra_netns_notify.c: In function 'zebra_ns_ready_read':
zebra/zebra_netns_notify.c:266:40: error: implicit declaration of function 'basename' [-Wimplicit-function-declaration]
  266 |         if (strmatch(VRF_DEFAULT_NAME, basename(netnspath))) {
      |                                        ^~~~~~~~

Fixed by including libgen.h, then since basename may modify its
parameter, allocate a copy on the stack, using strdupa, and pass the
temporary string to basename.

According to the man page for basename:
With glibc, one gets the POSIX version of basename() when
<libgen.h> is included, and the GNU version otherwise.

The POSIX version of basename may modify the contents of path,
so we should to pass a copy when calling this function.

[1] https://man7.org/linux/man-pages/man3/basename.3.html

Signed-off-by: Georgi Valkov <gvalkov@gmail.com>

zebra/zebra_netns_notify.c

@@ -15,6 +15,7 @@
 #include <sched.h>
 #endif
 #include <dirent.h>
+#include <libgen.h>
 #include <sys/inotify.h>
 #include <sys/stat.h>
 
@@ -234,6 +235,7 @@ static void zebra_ns_ready_read(struct event *t)
 {
 	struct zebra_netns_info *zns_info = EVENT_ARG(t);
 	const char *netnspath;
+	const char *netnspath_basename;
 	int err, stop_retry = 0;
 
 	if (!zns_info)
@@ -261,23 +263,24 @@ static void zebra_ns_ready_read(struct event *t)
 		zebra_ns_continue_read(zns_info, stop_retry);
 		return;
 	}
+	netnspath_basename = basename(strdupa(netnspath));
 
 	/* check default name is not already set */
-	if (strmatch(VRF_DEFAULT_NAME, basename(netnspath))) {
-		zlog_warn("NS notify : NS %s is already default VRF.Cancel VRF Creation", basename(netnspath));
+	if (strmatch(VRF_DEFAULT_NAME, netnspath_basename)) {
+		zlog_warn("NS notify : NS %s is already default VRF.Cancel VRF Creation", netnspath_basename);
 		zebra_ns_continue_read(zns_info, 1);
 		return;
 	}
-	if (zebra_ns_notify_is_default_netns(basename(netnspath))) {
+	if (zebra_ns_notify_is_default_netns(netnspath_basename)) {
 		zlog_warn(
 			"NS notify : NS %s is default VRF. Ignore VRF creation",
-			basename(netnspath));
+			netnspath_basename);
 		zebra_ns_continue_read(zns_info, 1);
 		return;
 	}
 
 	/* success : close fd and create zns context */
-	zebra_ns_notify_create_context_from_entry_name(basename(netnspath));
+	zebra_ns_notify_create_context_from_entry_name(netnspath_basename);
 	zebra_ns_continue_read(zns_info, 1);
 }
 
@@ -396,7 +399,7 @@ void zebra_ns_notify_parse(void)
 			continue;
 		}
 		/* check default name is not already set */
-		if (strmatch(VRF_DEFAULT_NAME, basename(dent->d_name))) {
+		if (strmatch(VRF_DEFAULT_NAME, basename(strdupa(dent->d_name)))) {
 			zlog_warn("NS notify : NS %s is already default VRF.Cancel VRF Creation", dent->d_name);
 			continue;
 		}