netdev-offload-tc: Add checking when assigning flow api

netdev_assign_flow_api will try to init the netdev,
if success, the netdev will use the offload api.
If we init the type of netdev is dpdk, using the tc offload
api (netdev_tc_init_flow_api, which may be called firstly.),
the err log always is showing up. This patch adds a additional
check, and can void the err log.

"failed adding ingress qdisc required for offloading: No such device"

Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
Signed-off-by: 0-day Robot <robot@bytheb.org>

lib/netdev-linux.c

@@ -3317,6 +3317,27 @@ const struct netdev_class netdev_afxdp_class = {
 #endif
 
 
+static bool
+is_linux_class(const struct netdev_class *class)
+{
+    if (class->destruct == netdev_linux_destruct) {
+        return true;
+    }
+#ifdef HAVE_AF_XDP
+    if (class->destruct == netdev_afxdp_destruct) {
+        return true;
+    }
+#endif
+
+    return false;
+}
+
+bool
+netdev_linux_flow_api_supported(const struct netdev *netdev)
+{
+    return is_linux_class(netdev->netdev_class);
+}
+
 #define CODEL_N_QUEUES 0x0000
 
 /* In sufficiently new kernel headers these are defined as enums in

lib/netdev-linux.h

@@ -28,5 +28,6 @@ struct netdev;
 int netdev_linux_ethtool_set_flag(struct netdev *netdev, uint32_t flag,
                                   const char *flag_name, bool enable);
 int linux_get_ifindex(const char *netdev_name);
+bool netdev_linux_flow_api_supported(const struct netdev *netdev);
 
 #endif /* netdev-linux.h */

lib/netdev-offload-tc.c

@@ -1643,6 +1643,10 @@ netdev_tc_init_flow_api(struct netdev *netdev)
     int ifindex;
     int error;
 
+    if (!netdev_linux_flow_api_supported(netdev)) {
+        return EOPNOTSUPP;
+    }
+
     ifindex = netdev_get_ifindex(netdev);
     if (ifindex < 0) {
         VLOG_INFO("init: failed to get ifindex for %s: %s",