close stdin before dup-ing, check return value of dup2

1 files changed, 12 insertions, 6 deletions

diff --git a/src/transport/gnunet_wlan_sender.c b/src/transport/gnunet_wlan_sender.c
index 89bfa0820..3aa32fb1c 100644
--- a/src/transport/gnunet_wlan_sender.c
+++ b/src/transport/gnunet_wlan_sender.c
@@ -30,6 +30,7 @@
 #include <netinet/in.h>
 #include <string.h>
 #include <time.h>
+#include <errno.h>
 #include "gnunet_protocols.h"
 #include "plugin_transport_wlan.h"
 
@@ -216,13 +217,18 @@ int main(int argc, char *argv[]){
         }
         else{
                 /* A zero PID indicates that this is the child process */
-                dup2(commpipe[0],0);    /* Replace stdin with the in side of the pipe */
-                close(commpipe[1]);             /* Close unused side of pipe (out side) */
+                (void) close(0);
+                if (-1 == dup2(commpipe[0],0))  /* Replace stdin with the in side of the pipe */
+                  fprintf (stderr,
+                           "dup2 failed: %s\n",
+                           strerror (errno));
+                (void) close(commpipe[1]);              /* Close unused side of pipe (out side) */
                 /* Replace the child fork with a new process */
-                if(execl("gnunet-transport-wlan-helper","gnunet-transport-wlan-helper", argv[1], NULL) == -1){
-                        fprintf(stderr,"Could not start gnunet-transport-wlan-helper!");
-                        exit(1);
-                }
+                if (execl("gnunet-transport-wlan-helper","gnunet-transport-wlan-helper", argv[1], NULL) == -1)
+                  {
+                    fprintf(stderr,"Could not start gnunet-transport-wlan-helper!");
+                    _exit(1);
+                  }
         }
         return 0;
 }