Merge branch 'tee_recursion_fix' into release-1.0GA

Conflicts:
	server/modules/filter/test/tee_recursion.sh

server/modules/filter/tee.c

@@ -107,7 +107,6 @@ static	void	setDownstream(FILTER *instance, void *fsession, DOWNSTREAM *downstre
 static	int	routeQuery(FILTER *instance, void *fsession, GWBUF *queue);
 static	void	diagnostic(FILTER *instance, void *fsession, DCB *dcb);
 
-
 static FILTER_OBJECT MyObject = {
     createInstance,
     newSession,
@@ -153,6 +152,33 @@ typedef struct {
 } TEE_SESSION;
 
 static int packet_is_required(GWBUF *queue);
+static int detect_loops(TEE_INSTANCE *instance, HASHTABLE* ht, SERVICE* session);
+
+static int hkfn(
+		void* key)
+{
+  if(key == NULL){
+    return 0;
+  }
+  unsigned int hash = 0,c = 0;
+  char* ptr = (char*)key;
+  while((c = *ptr++)){
+    hash = c + (hash << 6) + (hash << 16) - hash;
+  }
+  return *(int *)key;
+}
+
+static int hcfn(
+	void* v1,
+	void* v2)
+{
+  char* i1 = (char*) v1;
+  char* i2 = (char*) v2;
+
+  return strcmp(i1,i2);
+}
+
+
 /**
  * Implementation of the mandatory version entry point
  *
@@ -313,7 +339,20 @@ char		*remote, *userName;
 		my_session = NULL;
 		goto retblock;
 	}
-
+    
+    HASHTABLE* ht = hashtable_alloc(100,hkfn,hcfn);
+    bool is_loop = detect_loops(my_instance,ht,session->service);
+    hashtable_free(ht);
+    
+    if(is_loop)
+    {
+        LOGIF(LE, (skygw_log_write_flush(LOGFILE_ERROR,
+			"Error : %s: Recursive use of tee filter in service.",
+			session->service->name)));
+		my_session = NULL;
+		goto retblock;
+    }
+    
 	if ((my_session = calloc(1, sizeof(TEE_SESSION))) != NULL)
 	{
 		my_session->active = 1;
@@ -373,6 +412,7 @@ char		*remote, *userName;
 				
 				goto retblock;
 			}
+
 			ses->ses_is_child = true;
 			my_session->branch_session = ses;
 			my_session->branch_dcb = dcb;
@@ -641,3 +681,53 @@ int		i;
 				return 1;
 	return 0;
 }
+
+/**
+ * Detects possible loops in the query cloning chain.
+ */
+int detect_loops(TEE_INSTANCE *instance,HASHTABLE* ht, SERVICE* service)
+{
+    SERVICE* svc = service;
+    bool recurse = true;
+    int i;
+
+    if(ht == NULL)
+    {
+        return -1;
+    }
+
+    if(hashtable_add(ht,(void*)service->name,(void*)true) == 0)
+    {
+        return true;
+    }
+    
+    for(i = 0;i<svc->n_filters;i++)
+    {
+        if(strcmp(svc->filters[i]->module,"tee") == 0)
+        {
+            /*
+             * Found a Tee filter, recurse down its path
+             * if the service name isn't already in the hashtable.
+             */
+
+            TEE_INSTANCE* ninst = (TEE_INSTANCE*)svc->filters[i]->filter;
+            if(ninst == NULL)
+            {
+                /**
+                 * This tee instance hasn't been initialized yet and full
+                 * resolution of recursion cannot be done now.
+                 */
+                continue;
+            }
+            SERVICE* tgt = ninst->service;
+
+            if(detect_loops((TEE_INSTANCE*)svc->filters[i]->filter,ht,tgt))
+            {
+                return true;
+            }
+                
+        }
+    }
+    
+    return false;
+}