fix setLinkUp/Down commands

interface.cpp

@@ -41,82 +41,108 @@ m_index(-1)
   m_index = Utils::interfaceIndex(interface);
 }
 
-bool Interface::setLinkUp(QString &error) {
+/*!
+    Set the interface's administrative link state to up. Requires that the CAP_NET_ADMIN capability be set on the application binary, or run as root (\a not \a recommended). Returns 0 on success, 1 on error.
+*/
+int Interface::setLinkUp(QString &error) {
   struct rtnl_link *link, *link_orig = NULL;
   struct nl_sock *sock = NULL;
   QByteArray interfaceArray = m_interface.toLatin1();
   const char *interface = interfaceArray.constData();
 
   if((sock = Utils::connect())) {
-    rtnl_link_get_kernel(sock, 0, interface, &link_orig);
-
-    if(rtnl_link_get_kernel(sock, 0, interface, &link) < 0) {
+    if(rtnl_link_get_kernel(sock, 0, interface, &link_orig) < 0) {
       std::cerr << "error looking up interface" << std::endl;
       nl_socket_free(sock);
     }else{
-      unsigned int flags = rtnl_link_get_flags(link);
-      int err = 0;
+      if(!link_orig) {
+        std::cerr << "can't get link" << std::endl;
+        nl_socket_free(sock);
+        return 0;
+      }
 
-      flags |= IFF_UP;
+      link = rtnl_link_alloc();
 
-      rtnl_link_set_flags(link, flags);
+      if(!link) {
+        std::cerr << "can't alloc link" << std::endl;
+        rtnl_link_put(link_orig);
+        nl_socket_free(sock);
+        return 0;
+      }
+
+      int err = 0;
+
+      rtnl_link_set_flags(link, IFF_UP);
 
       if((err = rtnl_link_change(sock, link_orig, link, 0)) < 0) {
         error = nl_geterror(err);
         rtnl_link_put(link);
         rtnl_link_put(link_orig);
         nl_socket_free(sock);
-        return false;
+        return 0;
       }
 
       rtnl_link_put(link);
       rtnl_link_put(link_orig);
       nl_socket_free(sock);
 
-      return true;
+      return 1;
     }
   }
 
-  return false;
+  return 0;
 }
 
-bool Interface::setLinkDown(QString &error) {
+/*!
+    Set the interface's administrative link state to down. Requires that the CAP_NET_ADMIN capability be set on the application binary, or run as root (\a not \a recommended). Returns 0 on success, 1 on error.
+*/
+int Interface::setLinkDown(QString &error) {
   struct rtnl_link *link, *link_orig = NULL;
   struct nl_sock *sock = NULL;
   QByteArray interfaceArray = m_interface.toLatin1();
   const char *interface = interfaceArray.constData();
 
   if((sock = Utils::connect())) {
-    rtnl_link_get_kernel(sock, 0, interface, &link_orig);
-
-    if(rtnl_link_get_kernel(sock, 0, interface, &link) < 0) {
+    if(rtnl_link_get_kernel(sock, 0, interface, &link_orig) < 0) {
       std::cerr << "error looking up interface" << std::endl;
       nl_socket_free(sock);
     }else{
-      unsigned int flags = rtnl_link_get_flags(link);
-      int err = 0;
+      if(!link_orig) {
+        std::cerr << "can't get link" << std::endl;
+        nl_socket_free(sock);
+        return 0;
+      }
 
-      flags &= ~IFF_UP;
+      link = rtnl_link_alloc();
 
-      rtnl_link_set_flags(link, flags);
+      if(!link) {
+        std::cerr << "can't alloc link" << std::endl;
+        rtnl_link_put(link_orig);
+        nl_socket_free(sock);
+        return 0;
+      }
+
+      int err = 0;
+
+      rtnl_link_unset_flags(link, IFF_UP);
 
       if((err = rtnl_link_change(sock, link_orig, link, 0)) < 0) {
         error = nl_geterror(err);
         rtnl_link_put(link);
         rtnl_link_put(link_orig);
         nl_socket_free(sock);
-        return false;
+        return 0;
       }
 
       rtnl_link_put(link);
       rtnl_link_put(link_orig);
       nl_socket_free(sock);
 
-      return true;
+      return 1;
     }
   }
 
-  return false;
+  return 0;
 }
 
 /*!