api: binary api cleanup

Multiple API message handlers call vnet_get_sup_hw_interface(...)
without checking the inbound sw_if_index. This can cause a
pool_elt_at_index ASSERT in a debug image, and major disorder in a
production image.

Given that a number of places are coded as follows, add an
"api_visible_or_null" variant of vnet_get_sup_hw_interface, which
returns NULL given an invalid sw_if_index, or a hidden sw interface:

-  hw = vnet_get_sup_hw_interface (vnm, sw_if_index);
+  hw = vnet_get_sup_hw_interface_api_visible_or_null (vnm, sw_if_index);
   if (hw == NULL || memif_device_class.index != hw->dev_class_index)
     return clib_error_return (0, "not a memif interface");

Rename two existing xxx_safe functions -> xxx_or_null to make it
obvious what they return.

Type: fix

Change-Id: I29996e8d0768fd9e0c5495bd91ff8bedcf2c5697
Signed-off-by: Dave Barach <dave@barachs.net>
(cherry picked from commit 3940de36728b768574a3e998389bb90d55f690d1)

2 files changed, 6 insertions, 4 deletions

diff --git a/src/plugins/vmxnet3/cli.c b/src/plugins/vmxnet3/cli.c
index 776901e8ac2..1d75b0cf7df 100644
--- a/src/plugins/vmxnet3/cli.c
+++ b/src/plugins/vmxnet3/cli.c
@@ -108,7 +108,7 @@ vmxnet3_delete_command_fn (vlib_main_t * vm, unformat_input_t * input,
     return clib_error_return (0,
 			      "please specify interface name or sw_if_index");
 
-  hw = vnet_get_sup_hw_interface (vnm, sw_if_index);
+  hw = vnet_get_sup_hw_interface_api_visible_or_null (vnm, sw_if_index);
   if (hw == NULL || vmxnet3_device_class.index != hw->dev_class_index)
     return clib_error_return (0, "not a vmxnet3 interface");
 
@@ -165,7 +165,7 @@ vmxnet3_test_command_fn (vlib_main_t * vm, unformat_input_t * input,
     return clib_error_return (0,
 			      "please specify interface name or sw_if_index");
 
-  hw = vnet_get_sup_hw_interface (vnm, sw_if_index);
+  hw = vnet_get_sup_hw_interface_api_visible_or_null (vnm, sw_if_index);
   if (hw == NULL || vmxnet3_device_class.index != hw->dev_class_index)
     return clib_error_return (0, "not a vmxnet3 interface");
 
diff --git a/src/plugins/vmxnet3/vmxnet3_api.c b/src/plugins/vmxnet3/vmxnet3_api.c
index 5e1bb9e2f18..541ca732e6d 100644
--- a/src/plugins/vmxnet3/vmxnet3_api.c
+++ b/src/plugins/vmxnet3/vmxnet3_api.c
@@ -97,10 +97,12 @@ vl_api_vmxnet3_delete_t_handler (vl_api_vmxnet3_delete_t * mp)
   vnet_hw_interface_t *hw;
   int rv = 0;
 
-  hw = vnet_get_sup_hw_interface (vnm, htonl (mp->sw_if_index));
+  hw =
+    vnet_get_sup_hw_interface_api_visible_or_null (vnm,
+						   htonl (mp->sw_if_index));
   if (hw == NULL || vmxnet3_device_class.index != hw->dev_class_index)
     {
-      rv = VNET_API_ERROR_INVALID_INTERFACE;
+      rv = VNET_API_ERROR_INVALID_SW_IF_INDEX;
       goto reply;
     }