Change IPFIX Json headers #105

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1. xoredbyte commented on Oct 24, 2025

   

   xoredbyte

   on Oct 24, 2025

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   You need to modify the code in the libfds repository (https://github.com/CESNET/libfds/) in the json.c file located at libfds/src/converters as below:

   Comment out the code portion

   /*
   // Add a string identifier
   const size_t scope_size = strlen(def->scope->name);
   const size_t elem_size = strlen(def->name);

   size_t size = scope_size + elem_size + 5; // 2x '"' + 2x ':' + '\0'
   int ret_code = buffer_reserve(buffer, buffer_used(buffer) + size);
   if (ret_code != FDS_OK) {
       return ret_code;
   }
   *(buffer->write_begin++) = '"';
   memcpy(buffer->write_begin, def->scope->name, scope_size);
   buffer->write_begin += scope_size;
   
   *(buffer->write_begin++) = ':';
   memcpy(buffer->write_begin, def->name, elem_size);
   buffer->write_begin += elem_size;
   *(buffer->write_begin++) = '"';
   *(buffer->write_begin++) = ':';
   

   */

   //Replace with this

   // Add a string identifier (MODIFIED - without scope prefix)
   const size_t elem_size = strlen(def->name);

   // Only need space for: 2x '"' + ':' + element name + '\0'
   size_t size = elem_size + 4; // 2x '"' + ':' + '\0'
   int ret_code = buffer_reserve(buffer, buffer_used(buffer) + size);
   if (ret_code != FDS_OK) {
   return ret_code;
   }

   *(buffer->write_begin++) = '"';
   // Removed: memcpy(buffer->write_begin, def->scope->name, scope_size);
   // Removed: buffer->write_begin += scope_size;
   // Removed: *(buffer->write_begin++) = ':';

   // Only copy the element name (no scope prefix)
   memcpy(buffer->write_begin, def->name, elem_size);
   buffer->write_begin += elem_size;

   *(buffer->write_begin++) = '"';
   *(buffer->write_begin++) = ':';

   ---

   Then recompile libfds with

   $ mkdir build
   $ cd build
   $ cmake .. -DCMAKE_INSTALL_PREFIX=/usr
   $ make
   $ make install