/*
 * smb.c
 *
 * Copyright (C) 2016-18 - 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"

#include "ndpi_api.h"

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

    NDPI_LOG_DBG(ndpi_struct, "search SMB\n");

    /* Check connection over TCP */
    if(packet->tcp) {

        if(packet->tcp->dest == htons(445)
                && packet->payload_packet_len > (32 + 4 + 4)
                && (packet->payload_packet_len - 4) == ntohl(get_u_int32_t(packet->payload, 0))
                && get_u_int32_t(packet->payload, 4) == htonl(0xff534d42)) {

            NDPI_LOG_INFO(ndpi_struct, "found SMB\n");

            if(packet->payload[8] == 0x72)
                ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_SMBV1);
            else
                ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_SMBV23);
            return;
        }
    }

    ndpi_exclude_protocol(ndpi_struct,
            flow, NDPI_PROTOCOL_SMBV1, __FILE__, __FUNCTION__, __LINE__);
    ndpi_exclude_protocol(ndpi_struct,
            flow, NDPI_PROTOCOL_SMBV23, __FILE__, __FUNCTION__, __LINE__);
}

void init_smb_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
    ndpi_set_bitmask_protocol_detection("SMB", ndpi_struct, detection_bitmask, *id,
            NDPI_PROTOCOL_SMBV23,
            ndpi_search_smb_tcp,
            NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
            SAVE_DETECTION_BITMASK_AS_UNKNOWN,
            ADD_TO_DETECTION_BITMASK);

    *id += 1;
}
