af_xdp: fix default xdp program unload fail

Change to get ad->linux_ifindex in af_xdp_create_if() instead of in
af_xdp_load_program(), previous if did not load custom XDP program,
ad->linux_ifindex will be none, but bpf_xdp_detach() need it, so default
xdp program will be not unloaded when delete af_xdp interface.

Type: fix

Signed-off-by: Yulong Pei <yulong.pei@intel.com>
Change-Id: Id8a640204e8d29152f03349a0b58104b275635aa

1 files changed, 45 insertions, 20 deletions

diff --git a/src/plugins/af_xdp/device.c b/src/plugins/af_xdp/device.c
index a269e3c9723..06b86893646 100644
--- a/src/plugins/af_xdp/device.c
+++ b/src/plugins/af_xdp/device.c
@@ -145,6 +145,39 @@ af_xdp_exit_netns (char *netns, int *fds)
   return ret;
 }
 
+static int
+af_xdp_remove_program (af_xdp_device_t *ad)
+{
+  u32 curr_prog_id = 0;
+  int ret;
+  int ns_fds[2];
+
+  af_xdp_enter_netns (ad->netns, ns_fds);
+  ret = bpf_xdp_query_id (ad->linux_ifindex, XDP_FLAGS_UPDATE_IF_NOEXIST,
+			  &curr_prog_id);
+  if (ret != 0)
+    {
+      af_xdp_log (VLIB_LOG_LEVEL_ERR, ad, "bpf_xdp_query_id failed\n");
+      goto err0;
+    }
+
+  ret = bpf_xdp_detach (ad->linux_ifindex, XDP_FLAGS_UPDATE_IF_NOEXIST, NULL);
+  if (ret != 0)
+    {
+      af_xdp_log (VLIB_LOG_LEVEL_ERR, ad, "bpf_xdp_detach failed\n");
+      goto err0;
+    }
+  af_xdp_exit_netns (ad->netns, ns_fds);
+  if (ad->bpf_obj)
+    bpf_object__close (ad->bpf_obj);
+
+  return 0;
+
+err0:
+  af_xdp_exit_netns (ad->netns, ns_fds);
+  return ret;
+}
+
 void
 af_xdp_delete_if (vlib_main_t * vm, af_xdp_device_t * ad)
 {
@@ -172,15 +205,8 @@ af_xdp_delete_if (vlib_main_t * vm, af_xdp_device_t * ad)
   for (i = 0; i < ad->rxq_num; i++)
     clib_file_del_by_index (&file_main, vec_elt (ad->rxqs, i).file_index);
 
-  if (ad->bpf_obj)
-    {
-      int ns_fds[2];
-      af_xdp_enter_netns (ad->netns, ns_fds);
-      bpf_xdp_detach (ad->linux_ifindex, XDP_FLAGS_UPDATE_IF_NOEXIST, NULL);
-      af_xdp_exit_netns (ad->netns, ns_fds);
-
-      bpf_object__close (ad->bpf_obj);
-    }
+  if (af_xdp_remove_program (ad) != 0)
+    af_xdp_log (VLIB_LOG_LEVEL_ERR, ad, "Error while removing XDP program.\n");
 
   vec_free (ad->xsk);
   vec_free (ad->umem);
@@ -206,16 +232,6 @@ af_xdp_load_program (af_xdp_create_if_args_t * args, af_xdp_device_t * ad)
 		"setrlimit(%s) failed: %s (errno %d)", ad->linux_ifname,
 		strerror (errno), errno);
 
-  ad->linux_ifindex = if_nametoindex (ad->linux_ifname);
-  if (!ad->linux_ifindex)
-    {
-      args->rv = VNET_API_ERROR_INVALID_VALUE;
-      args->error =
-	clib_error_return_unix (0, "if_nametoindex(%s) failed",
-				ad->linux_ifname);
-      goto err0;
-    }
-
   ad->bpf_obj = bpf_object__open_file (args->prog, NULL);
   if (libbpf_get_error (ad->bpf_obj))
     {
@@ -251,7 +267,6 @@ err1:
   bpf_object__close (ad->bpf_obj);
   ad->bpf_obj = 0;
 err0:
-  ad->linux_ifindex = ~0;
   return -1;
 }
 
@@ -624,6 +639,16 @@ af_xdp_create_if (vlib_main_t * vm, af_xdp_create_if_args_t * args)
 
   ad->netns = (char *) format (0, "%s", args->netns);
 
+  ad->linux_ifindex = if_nametoindex (ad->linux_ifname);
+  if (!ad->linux_ifindex)
+    {
+      args->rv = VNET_API_ERROR_INVALID_VALUE;
+      args->error = clib_error_return_unix (0, "if_nametoindex(%s) failed",
+					    ad->linux_ifname);
+      ad->linux_ifindex = ~0;
+      goto err1;
+    }
+
   if (args->prog && af_xdp_load_program (args, ad))
     goto err2;