Interface patch byor Clemens Resen

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@326 f882894a-f735-0410-b71e-b25c423dba1c

contrib/check_dhcp.c

@@ -515,6 +515,7 @@ int receive_dhcp_packet(void *buffer, int buffer_size, int sock, int timeout, st
 /* creates a socket for DHCP communication */
 int create_dhcp_socket(void){
         struct sockaddr_in myname;
+	struct ifreq interface;
         int sock;
         int flag=1;
 
@@ -549,6 +550,13 @@ int create_dhcp_socket(void){
 		exit(STATE_UNKNOWN);
 	        }
 
+	/* bind socket to interface */
+	strncpy(interface.ifr_ifrn.ifrn_name,network_interface_name,IFNAMSIZ);
+	if(setsockopt(sock,SOL_SOCKET,SO_BINDTODEVICE,(char *)&interface,sizeof(interface))<0){
+		printf("Error: Could not bind socket to interface %s.  Check your privileges...\n",network_interface_name);
+		exit(STATE_UNKNOWN);
+	        }
+
         /* bind the socket */
         if(bind(sock,(struct sockaddr *)&myname,sizeof(myname))<0){
 		printf("Error: Could not bind to DHCP socket (port %d)!  Check your privileges...\n",DHCP_CLIENT_PORT);