Add extern to *_main global variable declarations in header files.

- Global variables declared in header files without
  the use of the 'extern' keword will result in multiple
  instances of the variable to be created by the compiler
  -- one for each different source file in which the
  the header file is included.  This results in wasted
  memory allocated in the BSS segments as well as
  potentially introducing bugs in the application.

Change-Id: I6ef1790b60a0bd9dd3994f8510723decf258b0cc
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>

2 files changed, 3 insertions, 1 deletions

diff --git a/src/plugins/ioam/ip6/ioam_cache.c b/src/plugins/ioam/ip6/ioam_cache.c
index 4e147da34dc..627f8b65d13 100644
--- a/src/plugins/ioam/ip6/ioam_cache.c
+++ b/src/plugins/ioam/ip6/ioam_cache.c
@@ -55,6 +55,8 @@
 #define REPLY_MSG_ID_BASE cm->msg_id_base
 #include <vlibapi/api_helper_macros.h>
 
+ioam_cache_main_t ioam_cache_main;
+
 /* List of message types that this plugin understands */
 #define foreach_ioam_cache_plugin_api_msg                        \
 _(IOAM_CACHE_IP6_ENABLE_DISABLE, ioam_cache_ip6_enable_disable)
diff --git a/src/plugins/ioam/ip6/ioam_cache.h b/src/plugins/ioam/ip6/ioam_cache.h
index 25a8fb65729..338ed9828ee 100644
--- a/src/plugins/ioam/ip6/ioam_cache.h
+++ b/src/plugins/ioam/ip6/ioam_cache.h
@@ -203,7 +203,7 @@ typedef struct
   u32 cleanup_process_node_index;
 } ioam_cache_main_t;
 
-ioam_cache_main_t ioam_cache_main;
+extern ioam_cache_main_t ioam_cache_main;
 
 extern vlib_node_registration_t ioam_cache_node;
 extern vlib_node_registration_t ioam_cache_ts_node;