From: Martin Schwenke <mschwenke@ddn.com>
Date: Mon, 12 Jan 2026 07:05:23 +0000 (+1100)
Subject: ctdb-common: Use if_nametoindex(3) to check if interface exists
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d19ad0bec55dccfc1891c320a2fed41cc139927f;p=thirdparty%2Fsamba.git

ctdb-common: Use if_nametoindex(3) to check if interface exists

This is much simpler than looping through the array.  It will also
find an interface by altname, which could be very useful.

Signed-off-by: Martin Schwenke <mschwenke@ddn.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
---

diff --git a/ctdb/common/system.c b/ctdb/common/system.c
index 05a95647233..170268c41fc 100644
--- a/ctdb/common/system.c
+++ b/ctdb/common/system.c
@@ -148,36 +148,18 @@ void ctdb_wait_for_process_to_exit(pid_t pid)
 	}
 }
 
-#ifdef HAVE_IF_NAMEINDEX
+#ifdef HAVE_IF_NAMETOINDEX
 
 bool ctdb_sys_check_iface_exists(const char *iface)
 {
-	struct if_nameindex *ifnis, *ifni;
-	bool found = false;
+	unsigned int index = 0;
 
-	ifnis = if_nameindex();
-	if (ifnis == NULL) {
-		DBG_ERR("Failed to retrieve interface list\n");
-		return false;
-	}
-
-	for (ifni = ifnis;
-	     ifni->if_index != 0 || ifni->if_name != NULL;
-	     ifni++) {
-		int cmp = strcmp(iface, ifni->if_name);
-		if (cmp == 0) {
-			found = true;
-			goto done;
-		}
-	}
-
-done:
-	if_freenameindex(ifnis);
+	index = if_nametoindex(iface);
 
-	return found;
+	return index != 0;
 }
 
-#else /* HAVE_IF_NAMEINDEX */
+#else /* HAVE_IF_NAMETOINDEX */
 
 bool ctdb_sys_check_iface_exists(const char *iface)
 {
@@ -185,7 +167,7 @@ bool ctdb_sys_check_iface_exists(const char *iface)
 	return true;
 }
 
-#endif /* HAVE_IF_NAMEINDEX */
+#endif /* HAVE_IF_NAMETOINDEX */
 
 #ifdef HAVE_PEERCRED