1 files changed, 9 insertions, 2 deletions

diff --git a/src/firejail/veth.c b/src/firejail/veth.c
index 803d8d503..0db55709b 100644
--- a/src/firejail/veth.c
+++ b/src/firejail/veth.c
@@ -136,8 +136,14 @@ int net_create_macvlan(const char *dev, const char *parent, unsigned pid) {
         req.n.nlmsg_type = RTM_NEWLINK;
         req.i.ifi_family = 0;
         
-        // we start with the parent
-        int parent_ifindex = 2;
+        // find parent ifindex
+        int parent_ifindex = if_nametoindex(parent);
+        if (parent_ifindex <= 0) {
+                fprintf(stderr, "Error: cannot find network device %s\n", parent);
+                exit(1);
+        }                       
+
+        // add parent
         addattr_l(&req.n, sizeof(req), IFLA_LINK, &parent_ifindex, 4);
 
         // add new interface name
@@ -173,6 +179,7 @@ int net_create_macvlan(const char *dev, const char *parent, unsigned pid) {
         return 0;
 }
 
+
 /*
 int main(int argc, char **argv) {
         printf("Hello\n");