Modifier: work with value returned from callback

Author: AdamZvara

include/ipfixcol2/modifier.h

@@ -54,7 +54,7 @@ struct ipx_modifier_output {
  * \note output size is equal to number of new fields
  * \note Any non-negative value in output[i].length means that
  * data in output at given position is valid and will be appended to IPFIX message
- * \return #IPX_OK if function was successfull, otherwise any non-zero value
+ * \return #IPX_OK if function was successfull, #IPX_ERR_DENIED if modification can not continue
  */
 typedef int (*modifier_adder_cb_t)(const struct fds_drec *rec,
     struct ipx_modifier_output output[], void *cb_data);

src/core/modifier.c

@@ -1090,7 +1090,11 @@ ipx_modifier_modify(ipx_modifier_t *mod, const struct fds_drec *rec, ipx_msg_gar
     output_buffers_init(buffers, mod->fields_cnt);
     if (mod->cb_adder) {
         // Call adder callback to fill output buffers
-        mod->cb_adder(rec, buffers, mod->cb_data);
+        int cb_rc = mod->cb_adder(rec, buffers, mod->cb_data);
+        if (cb_rc != IPX_OK) {
+            MODIFIER_ERROR(mod, "Callback function returned error code %d", cb_rc);
+            return NULL;
+        }
     }
 
     // Update template based on modified configuration

src/plugins/intermediate/asn/asn.c

@@ -418,7 +418,7 @@ process_ipfix(ipx_ctx_t *ctx, ipx_modifier_t *modifier, ipx_msg_builder_t *build
         }
         if (!modified_rec) {
             // Proper message has been already printed
-            return rc;
+            return IPX_ERR_DENIED;
         }
 
         // Store modified record in builder

src/plugins/intermediate/geoip/geoip.c

@@ -519,7 +519,7 @@ process_ipfix(ipx_ctx_t *ctx, ipx_modifier_t *modifier, ipx_msg_builder_t *build
         }
         if (!modified_rec) {
             // Proper message has been already printed
-            return rc;
+            return IPX_ERR_DENIED;
         }
 
         // Store modified record in builder