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, 5 insertions, 5 deletions

diff --git a/src/vnet/bfd/bfd_cli.c b/src/vnet/bfd/bfd_cli.c
index cab20a65b0b..4b5f75eb01b 100644
--- a/src/vnet/bfd/bfd_cli.c
+++ b/src/vnet/bfd/bfd_cli.c
@@ -170,7 +170,7 @@ show_bfd (vlib_main_t * vm, unformat_input_t * input,
       if (is_set)
 	{
 	  vnet_sw_interface_t *sw_if =
-	    vnet_get_sw_interface_safe (&vnet_main, sw_if_index);
+	    vnet_get_sw_interface_or_null (&vnet_main, sw_if_index);
 	  vnet_hw_interface_t *hw_if =
 	    vnet_get_hw_interface (&vnet_main, sw_if->hw_if_index);
 	  u8 *s = format (NULL, "UDP echo source is: %v\n", hw_if->name);
diff --git a/src/vnet/bfd/bfd_udp.c b/src/vnet/bfd/bfd_udp.c
index 147cd6eda99..ca5bae51561 100644
--- a/src/vnet/bfd/bfd_udp.c
+++ b/src/vnet/bfd/bfd_udp.c
@@ -78,7 +78,7 @@ vnet_api_error_t
 bfd_udp_set_echo_source (u32 sw_if_index)
 {
   vnet_sw_interface_t *sw_if =
-    vnet_get_sw_interface_safe (bfd_udp_main.vnet_main, sw_if_index);
+    vnet_get_sw_interface_or_null (bfd_udp_main.vnet_main, sw_if_index);
   if (sw_if)
     {
       bfd_udp_main.echo_source_sw_if_index = sw_if_index;
@@ -110,8 +110,8 @@ bfd_udp_is_echo_available (bfd_transport_e transport)
    * pick an unused address from that subnet
    */
   vnet_sw_interface_t *sw_if =
-    vnet_get_sw_interface_safe (bfd_udp_main.vnet_main,
-				bfd_udp_main.echo_source_sw_if_index);
+    vnet_get_sw_interface_or_null (bfd_udp_main.vnet_main,
+				   bfd_udp_main.echo_source_sw_if_index);
   if (sw_if && sw_if->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
     {
       if (BFD_TRANSPORT_UDP4 == transport)
@@ -545,7 +545,7 @@ bfd_udp_validate_api_input (u32 sw_if_index,
 {
   bfd_udp_main_t *bum = &bfd_udp_main;
   vnet_sw_interface_t *sw_if =
-    vnet_get_sw_interface_safe (bfd_udp_main.vnet_main, sw_if_index);
+    vnet_get_sw_interface_or_null (bfd_udp_main.vnet_main, sw_if_index);
   u8 local_ip_valid = 0;
   ip_interface_address_t *ia = NULL;
   if (!sw_if)