set_hdr = (struct ipfix_set_header*)((uint8_t*)msg.data + set_hdr_offset);
set_hdr->length = htons(msg.size - set_hdr_offset);
set_hdr = (struct ipfix_set_header*)((uint8_t*)msg.data + set_hdr_offset);
set_hdr->length = htons(msg.size - set_hdr_offset);