linux-cp: handle ipv4 routes when link goes down on subif

Type: improvement

Currently, the plugin can monitor link state changes on hardware
interfaces for which a linux-cp pair exists. When the link goes down on
one of the hardware interfaces, the plugin processes IPv4 routes that
resolve through that interface according to the configurations:
del-static-on-link-down and del-dynamic-on-link-down.

The problem is that link state changes are not signaled for
subinterfaces and the code that handles IPv4 routes is not triggered.
When the link on a hardware interface goes down, it implies
that subinterfaces added to that interface also will have the link in
the down state.

With this change, when the link goes down on a hardware interface,
iterate over subinterfaces added to the interface and apply the same
logic of routes processing as for hardware interfaces.

Signed-off-by: Alexander Chernavin <achernavin@netgate.com>
Change-Id: I97337d2e328437c73f2d99a00737768778f197a1

1 files changed, 43 insertions, 17 deletions

diff --git a/src/plugins/linux-cp/lcp_router.c b/src/plugins/linux-cp/lcp_router.c
index 4aab148a456..05943e4ca67 100644
--- a/src/plugins/linux-cp/lcp_router.c
+++ b/src/plugins/linux-cp/lcp_router.c
@@ -512,33 +512,59 @@ lcp_router_link_up_down (vnet_main_t *vnm, u32 hw_if_index, u32 flags)
        lcp_get_del_dynamic_on_link_down ()))
     {
       u32 fib_index;
+      u32 **fib_index_to_sw_if_index_to_bool = NULL;
+      u32 id, sw_if_index;
       lcp_router_table_t *nlt;
 
       fib_index = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
 						       hi->sw_if_index);
 
-      pool_foreach (nlt, lcp_router_table_pool)
+      vec_validate_init_empty (fib_index_to_sw_if_index_to_bool, fib_index,
+			       NULL);
+      vec_validate_init_empty (fib_index_to_sw_if_index_to_bool[fib_index],
+			       hi->sw_if_index, false);
+      fib_index_to_sw_if_index_to_bool[fib_index][hi->sw_if_index] = true;
+
+      /* clang-format off */
+      hash_foreach (id, sw_if_index, hi->sub_interface_sw_if_index_by_id,
+      ({
+	fib_index = fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
+							 sw_if_index);
+	vec_validate_init_empty (fib_index_to_sw_if_index_to_bool, fib_index,
+				 NULL);
+	vec_validate_init_empty (fib_index_to_sw_if_index_to_bool[fib_index],
+				 sw_if_index, false);
+	fib_index_to_sw_if_index_to_bool[fib_index][sw_if_index] = true;
+      }));
+      /* clang-format on */
+
+      vec_foreach_index (fib_index, fib_index_to_sw_if_index_to_bool)
 	{
-	  if (fib_index == nlt->nlt_fib_index &&
-	      FIB_PROTOCOL_IP4 == nlt->nlt_proto)
-	    {
-	      u32 *sw_if_index_to_bool = NULL;
-
-	      vec_validate_init_empty (sw_if_index_to_bool, hi->sw_if_index,
-				       false);
-	      sw_if_index_to_bool[hi->sw_if_index] = true;
+	  u32 *sw_if_index_to_bool;
 
-	      if (lcp_get_del_static_on_link_down ())
-		lcp_router_table_flush (nlt, sw_if_index_to_bool,
-					lcp_rt_fib_src);
-	      if (lcp_get_del_dynamic_on_link_down ())
-		lcp_router_table_flush (nlt, sw_if_index_to_bool,
-					lcp_rt_fib_src_dynamic);
+	  sw_if_index_to_bool = fib_index_to_sw_if_index_to_bool[fib_index];
+	  if (NULL == sw_if_index_to_bool)
+	    continue;
 
-	      vec_free (sw_if_index_to_bool);
-	      break;
+	  pool_foreach (nlt, lcp_router_table_pool)
+	    {
+	      if (fib_index == nlt->nlt_fib_index &&
+		  FIB_PROTOCOL_IP4 == nlt->nlt_proto)
+		{
+		  if (lcp_get_del_static_on_link_down ())
+		    lcp_router_table_flush (nlt, sw_if_index_to_bool,
+					    lcp_rt_fib_src);
+		  if (lcp_get_del_dynamic_on_link_down ())
+		    lcp_router_table_flush (nlt, sw_if_index_to_bool,
+					    lcp_rt_fib_src_dynamic);
+		  break;
+		}
 	    }
+
+	  vec_free (sw_if_index_to_bool);
 	}
+
+      vec_free (fib_index_to_sw_if_index_to_bool);
     }
 
   return 0;