Adapt programs to the new NET API
diff --git a/programs/ssl/dtls_server.c b/programs/ssl/dtls_server.c
index ef7ce94..e1da0f7 100644
--- a/programs/ssl/dtls_server.c
+++ b/programs/ssl/dtls_server.c
@@ -92,8 +92,7 @@
 int main( void )
 {
     int ret, len;
-    int listen_fd;
-    int client_fd = -1;
+    mbedtls_net_context listen_fd, client_fd;
     unsigned char buf[1024];
     const char *pers = "dtls_server";
     unsigned char client_ip[16] = { 0 };
@@ -111,6 +110,8 @@
     mbedtls_ssl_cache_context cache;
 #endif
 
+    mbedtls_net_init( &listen_fd );
+    mbedtls_net_init( &client_fd );
     mbedtls_ssl_init( &ssl );
     mbedtls_ssl_config_init( &conf );
     mbedtls_ssl_cookie_init( &cookie_ctx );
@@ -255,20 +256,17 @@
     }
 #endif
 
-    if( client_fd != -1 )
-        mbedtls_net_close( client_fd );
+    mbedtls_net_close( &client_fd );
 
     mbedtls_ssl_session_reset( &ssl );
 
     /*
      * 3. Wait until a client connects
      */
-    client_fd = -1;
-
     printf( "  . Waiting for a remote connection ..." );
     fflush( stdout );
 
-    if( ( ret = mbedtls_net_accept( listen_fd, &client_fd,
+    if( ( ret = mbedtls_net_accept( &listen_fd, &client_fd,
                     client_ip, sizeof( client_ip ), &cliip_len ) ) != 0 )
     {
         printf( " failed\n  ! mbedtls_net_accept returned %d\n\n", ret );
@@ -403,8 +401,8 @@
     }
 #endif
 
-    if( client_fd != -1 )
-        mbedtls_net_close( client_fd );
+    mbedtls_net_close( &client_fd );
+    mbedtls_net_close( &listen_fd );
 
     mbedtls_x509_crt_free( &srvcert );
     mbedtls_pk_free( &pkey );