/*
 * json-rpc.c
 *
 * Copyright (C) 2023 - ntop.org
 * Copyright (C) 2023 - V.G <v.gavrilov@securitycode.ru>
 *
 * This file is part of nDPI, an open source deep packet inspection
 * library based on the OpenDPI and PACE technology by ipoque GmbH
 *
 * nDPI is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * nDPI is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with nDPI.  If not, see <http://www.gnu.org/licenses/>.
 * 
 */

#include "ndpi_protocol_ids.h"

#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_JSON_RPC

#include "ndpi_api.h"
#include "ndpi_private.h"

static void ndpi_search_json_rpc(struct ndpi_detection_module_struct *ndpi_struct,
                                 struct ndpi_flow_struct *flow)
{
  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;

  NDPI_LOG_DBG(ndpi_struct, "search JSON-RPC\n");

  if (flow->detected_protocol_stack[0] == NDPI_PROTOCOL_HTTP ||
      flow->detected_protocol_stack[1] == NDPI_PROTOCOL_HTTP)
  {
    if ((packet->content_line.ptr != NULL) &&
        (LINE_ENDS(packet->content_line, "application/json-rpc") != 0))
    {
      NDPI_LOG_INFO(ndpi_struct, "found JSON-RPC over HTTP\n");
      ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_JSON_RPC, 
                                 NDPI_PROTOCOL_HTTP, NDPI_CONFIDENCE_DPI);
    }
    return;
  }

  if ((packet->payload_packet_len > 30) && (packet->payload[0] == '{') &&
      (ndpi_strnstr((const char *)packet->payload, "\"jsonrpc\":", packet->payload_packet_len)))
  {
    NDPI_LOG_INFO(ndpi_struct, "found JSON-RPC over TCP\n");
    ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_JSON_RPC,
                               NDPI_PROTOCOL_UNKNOWN, NDPI_CONFIDENCE_DPI);
    return;
  }

  NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
}

void init_json_rpc_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id)
{
  ndpi_set_bitmask_protocol_detection("JSON-RPC", ndpi_struct, *id,
				      NDPI_PROTOCOL_JSON_RPC,
				      ndpi_search_json_rpc,
				      NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
				      SAVE_DETECTION_BITMASK_AS_UNKNOWN,
				      ADD_TO_DETECTION_BITMASK);
  *id += 1;
}