/*

 * thrift.c

 *

 * Copyright (C) 2023 - ntop.org

 *

 * 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_APACHE_THRIFT

#include "ndpi_api.h"

#include "ndpi_private.h"

#include <stdint.h>

// References: https://thrift.apache.org AND https://github.com/apache/thrift

// Not Implemented (sub)protocols: TJSONProtocol, TSimpleJSONProtocol and TDebugProtocol

// TBinaryProtocol

PACK_ON

struct thrift_strict_hdr {

  uint8_t protocol_id;

  uint8_t version;

  uint8_t unused_byte_pad;

  uint8_t message_type;

  uint32_t method_length;

  char method[0];

} PACK_OFF;

// TCompactProtocol

PACK_ON

struct thrift_compact_hdr {

  uint8_t protocol_id;

#if defined(__BIG_ENDIAN__)

  uint8_t message_type : 3;

  uint8_t version : 5;

#elif defined(__LITTLE_ENDIAN__)

  uint8_t version : 5;

  uint8_t message_type : 3;

#else

#error "Missing endian macro definitions."

#endif

  uint8_t sequence_id[3];

  uint8_t method_length;

  char method[0];

} PACK_OFF;

enum thrift_message_type {

  TMT_INVALID_TMESSAGE_TYPE = 0,

  TMT_CALL                  = 1,

  TMT_REPLY                 = 2,

  TMT_EXCEPTION             = 3,

  TMT_ONEWAY                = 4,

  TMT_TYPE_MAX

};

static void ndpi_int_thrift_add_connection(struct ndpi_detection_module_struct *ndpi_struct,

                                           struct ndpi_flow_struct *flow,

                                           uint16_t master_protocol)

{

  switch (master_protocol)

  {

    case NDPI_PROTOCOL_UNKNOWN:

      NDPI_LOG_DBG(ndpi_struct, "found Apache Thrift TCP/UDP\n");

      break;

    case NDPI_PROTOCOL_HTTP:

      NDPI_LOG_DBG(ndpi_struct, "found Apache Thrift HTTP\n");

      break;

  }

  ndpi_set_detected_protocol(ndpi_struct, flow,

                             NDPI_PROTOCOL_APACHE_THRIFT, master_protocol,

                             NDPI_CONFIDENCE_DPI);

}

static int thrift_validate_method(char const * const method, size_t method_length)

{

  const union {

    uint8_t const * const ptr;

    char const * const str;

  } m = { .str = method };

  return ndpi_is_printable_buffer(m.ptr, method_length);

}

static int thrift_validate_version(uint8_t version)

{

  return version <= 0x01;

}

static int thrift_validate_type(uint8_t message_type)

{

  return message_type < TMT_TYPE_MAX;

}

static void thrift_set_method(struct ndpi_detection_module_struct *ndpi_struct,

                              struct ndpi_flow_struct *flow,

                              char const * const method, size_t method_length)

{

  if (thrift_validate_method(method, method_length) == 0) {

    ndpi_set_risk(ndpi_struct, flow, NDPI_INVALID_CHARACTERS, "Invalid method name");

    flow->protos.thrift.method[0] = '\0';

  } else {

    strncpy(flow->protos.thrift.method, method, ndpi_min(sizeof(flow->protos.thrift.method), method_length));

  }

}

static void thrift_set_type(struct ndpi_detection_module_struct *ndpi_struct,

                            struct ndpi_flow_struct *flow,

                            uint8_t message_type)

{

  if (message_type == TMT_INVALID_TMESSAGE_TYPE) {

    ndpi_set_risk(ndpi_struct, flow, NDPI_MALFORMED_PACKET, "Invalid message type");

  }

  flow->protos.thrift.message_type = message_type;

  if (message_type == TMT_EXCEPTION) {

    ndpi_set_risk(ndpi_struct, flow, NDPI_ERROR_CODE_DETECTED, "Apache Thrift Exception");

  }

}

static void ndpi_dissect_strict_hdr(struct ndpi_detection_module_struct *ndpi_struct,

                                    struct ndpi_flow_struct *flow,

                                    struct thrift_strict_hdr const * const strict_hdr)

{

  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;

  const size_t method_length = ntohl(strict_hdr->method_length);

  if (packet->tcp == NULL) {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  if (packet->payload_packet_len < sizeof(*strict_hdr) + method_length) {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  if (thrift_validate_version(strict_hdr->version) == 0) {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  if (thrift_validate_type(strict_hdr->message_type) == 0) {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  ndpi_int_thrift_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_UNKNOWN);

  thrift_set_method(ndpi_struct, flow, strict_hdr->method, method_length);

  thrift_set_type(ndpi_struct, flow, strict_hdr->message_type);

}

static void ndpi_dissect_compact_hdr(struct ndpi_detection_module_struct *ndpi_struct,

                                     struct ndpi_flow_struct *flow,

                                     struct thrift_compact_hdr const * const compact_hdr)

{

  struct ndpi_packet_struct const * const packet = &ndpi_struct->packet;

  if (packet->udp == NULL) {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  if (packet->payload_packet_len < sizeof(*compact_hdr) + compact_hdr->method_length) {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  if (thrift_validate_version(compact_hdr->version) == 0) {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  if (thrift_validate_type(compact_hdr->message_type) == 0) {

    NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

    return;

  }

  ndpi_int_thrift_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_UNKNOWN);

  thrift_set_method(ndpi_struct, flow, compact_hdr->method, compact_hdr->method_length);

  thrift_set_type(ndpi_struct, flow, compact_hdr->message_type);

}

static void ndpi_search_thrift_tcp_udp(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 Apache Thrift\n");

  if (flow->detected_protocol_stack[0] == NDPI_PROTOCOL_HTTP ||

      flow->detected_protocol_stack[1] == NDPI_PROTOCOL_HTTP)

  {

    /* Check Thrift over HTTP */

    if (packet->content_line.ptr != NULL)

    {

      if ((LINE_ENDS(packet->content_line, "application/vnd.apache.thrift.binary") != 0) ||

          (LINE_ENDS(packet->content_line, "application/vnd.apache.thrift.compact") != 0) ||

          (LINE_ENDS(packet->content_line, "application/vnd.apache.thrift.json") != 0))

      {

        NDPI_LOG_INFO(ndpi_struct, "found Apache Thrift over HTTP\n");

        ndpi_int_thrift_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_HTTP);

        return;

      }

    }

  } else if (packet->payload_packet_len >= sizeof(struct thrift_compact_hdr)) {

    const union {

      uint8_t const * const raw_ptr;

      struct thrift_strict_hdr const * const strict_hdr;

      struct thrift_compact_hdr const * const compact_hdr;

    } thrift_data = { .raw_ptr = &packet->payload[0] };

    if (thrift_data.raw_ptr[0] == 0x80)

    {

      /* Strict Binary Protocol */

      if (packet->payload_packet_len < sizeof(*thrift_data.strict_hdr))

      {

        NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

        return;

      }

      ndpi_dissect_strict_hdr(ndpi_struct, flow, thrift_data.strict_hdr);

      return;

    } else if (thrift_data.raw_ptr[0] == 0x82) {

      /* Compact Protocol */

      ndpi_dissect_compact_hdr(ndpi_struct, flow, thrift_data.compact_hdr);

      return;

    } else {

      /* Probably not Apache Thrift. */

      NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

      return;

    }

  }

  NDPI_EXCLUDE_DISSECTOR(ndpi_struct, flow);

}

void init_apache_thrift_dissector(struct ndpi_detection_module_struct *ndpi_struct)

{

  register_dissector("Thrift", ndpi_struct,

                     ndpi_search_thrift_tcp_udp,

                     NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_OR_UDP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,

                     1, NDPI_PROTOCOL_APACHE_THRIFT);

}