Transaction pull style API to retrieve variable value

headers/modsecurity/transaction.h

@@ -718,6 +718,9 @@ int msc_process_logging(Transaction *transaction);
 /** @ingroup ModSecurity_C_API */
 int msc_update_status_code(Transaction *transaction, int status);
 
+/** @ingroup ModSecurity_C_API */
+const char *msc_get_transaction_variable(Transaction *transaction, const char *var_name);
+
 #ifdef __cplusplus
 }
 }  // namespace modsecurity

src/transaction.cc

@@ -2356,6 +2356,66 @@ extern "C" int msc_update_status_code(Transaction *transaction, int status) {
     return transaction->updateStatusCode(status);
 }
 
+/**
+ * @name   msc_get_transaction_variable
+ * @brief  Retrieve variable value by name.
+ *
+ * This function returns tx_collection variable value by name.
+ *
+ * @param transaction ModSecurity transaction.
+ * @param var_name variable name
+ * @return variable value.
+ *
+ */
+extern "C" const char *msc_get_transaction_variable(Transaction *transaction, const char *var_name){
+    std::vector<const VariableValue *> l;
+    modsecurity::collection::Collection *c = NULL;
+    std::string cn;
+    const char *p = NULL;
+
+    if (var_name == NULL ){
+        return NULL;
+    }
+
+    p = strchr(var_name,':');
+
+    if ( p == NULL ){
+        return NULL;
+    }
+
+    cn = std::string(var_name,p-var_name);
+    transform(cn.begin(),cn.end(),cn.begin(),::tolower);
+
+    if ( cn.compare("global") == 0){
+        c = transaction->m_collections.m_global_collection;
+    }else if ( cn.compare("ip") == 0){
+        c = transaction->m_collections.m_ip_collection;
+    }else if ( cn.compare("session") == 0){
+        c = transaction->m_collections.m_session_collection;
+    }else if ( cn.compare("user") == 0){
+        c = transaction->m_collections.m_user_collection;
+    }else if ( cn.compare("resource") == 0){
+        c = transaction->m_collections.m_resource_collection;
+    }else if( cn.compare("tx") == 0){
+        c = transaction->m_collections.m_tx_collection;
+    }
+
+    if(c == NULL){
+        return NULL;
+    }
+
+    ++p;
+    cn = std::string(p);
+    transform(cn.begin(),cn.end(),cn.begin(),::tolower);
+
+    c->resolveSingleMatch(cn.c_str(),&l);
+
+    if ( l.size() < 1){
+        return NULL;
+    }
+
+    return l[0]->getValue().c_str();
+}
 
 }  // namespace modsecurity