jvpp: stop plugin intialization on first mismatch

Java bindings use get_message_id from jvpp-common
to detect if messages known at compile time
are avaliable at runtime.

In case of missing entry, Java exception is propagated
via JNI using (*env)->ThrowNew.

But this function does not end code execution so,
in order to prevent unexpected behaviour
(e.g. calling vl_msg_api_set_handlers with id == 0),
get_message_id caller should do it manually.

Change-Id: I2edb5013fd3658dcdd77a867b5cdf62e559ee071
Signed-off-by: Marek Gradzki <mgradzki@cisco.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/src/vpp-api/java/jvpp-common/jvpp_common.c b/src/vpp-api/java/jvpp-common/jvpp_common.c
index c00298bfa81..2425607c582 100644
--- a/src/vpp-api/java/jvpp-common/jvpp_common.c
+++ b/src/vpp-api/java/jvpp-common/jvpp_common.c
@@ -83,11 +83,14 @@ u32 get_message_id(JNIEnv *env, const char *key) {
     uword *p = hash_get(jvpp_main.messages_hash, key);
     if (!p) {
         jclass exClass = (*env)->FindClass(env, "java/lang/IllegalStateException");
-        char *msgBuf  = clib_mem_alloc(strlen(key) + 40);
+        char *msgBuf  = clib_mem_alloc(strlen(key) + 70);
         strcpy(msgBuf, "API mismatch detected: ");
         strcat(msgBuf, key);
-        strcat(msgBuf, " is missing");
-        DEBUG_LOG("get_message_id : %s\n", msgBuf);
+        strcat(msgBuf, " is missing in global name_crc hash table.");
+        DEBUG_LOG("%s", msgBuf);
+        DEBUG_LOG("Possible reasons:");
+        DEBUG_LOG("1) incompatible VPP version used");
+        DEBUG_LOG("2) message present in JSON file but not in global name_crc table");
         (*env)->ThrowNew(env, exClass, msgBuf);
         clib_mem_free(msgBuf);
         return 0;