/*
 * zmq.c
 *
 * Copyright (C) 2016-18 - ntop.org
 *
 * nDPI is free software: you can zmqtribute 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_ZMQ

#include "ndpi_api.h"

static void ndpi_int_zmq_add_connection(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow) {
    NDPI_LOG_INFO(ndpi_struct, "found ZMQ\n");
    ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_ZMQ);
}

static void ndpi_check_zmq(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow) {

    struct ndpi_packet_struct *packet = &flow->packet;
    u_int32_t payload_len = packet->payload_packet_len;
    u_char p0[] =  { 0x00, 0x00, 0x00, 0x05, 0x01, 0x66, 0x6c, 0x6f, 0x77 };
    u_char p1[] =  { 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x7f };
    u_char p2[] =  { 0x28, 0x66, 0x6c, 0x6f, 0x77, 0x00 };

    if(payload_len == 0) return; /* Shouldn't happen */

    /* Break after 17 packets. */
    if(flow->packet_counter > 17) {
        NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
        return;
    }

    if(flow->l4.tcp.prev_zmq_pkt_len == 0) {
        flow->l4.tcp.prev_zmq_pkt_len = ndpi_min(packet->payload_packet_len, 10);
        memcpy(flow->l4.tcp.prev_zmq_pkt, packet->payload, flow->l4.tcp.prev_zmq_pkt_len);
        return; /* Too early */
    }
    if(payload_len == 2) {
        if(flow->l4.tcp.prev_zmq_pkt_len == 2) {
            if((memcmp(packet->payload, "\01\01", 2) == 0)
                    && (memcmp(flow->l4.tcp.prev_zmq_pkt, "\01\02", 2) == 0)) {
                ndpi_int_zmq_add_connection(ndpi_struct, flow);
                return;
            }
        } else if(flow->l4.tcp.prev_zmq_pkt_len == 9) {
            if((memcmp(packet->payload, "\00\00", 2) == 0)
                    && (memcmp(flow->l4.tcp.prev_zmq_pkt, p0, 9) == 0)) {
                ndpi_int_zmq_add_connection(ndpi_struct, flow);
                return;
            }
        } else if(flow->l4.tcp.prev_zmq_pkt_len == 10) {
            if((memcmp(packet->payload, "\01\02", 2) == 0)
                    && (memcmp(flow->l4.tcp.prev_zmq_pkt, p1, 10) == 0)) {
                ndpi_int_zmq_add_connection(ndpi_struct, flow);
                return;
            }
        }
    } else if(payload_len >= 10) {
        if(flow->l4.tcp.prev_zmq_pkt_len == 10) {
            if(((memcmp(packet->payload, p1, 10) == 0)
                        && (memcmp(flow->l4.tcp.prev_zmq_pkt, p1, 10) == 0))
                    || ((memcmp(&packet->payload[1], p2, sizeof(p2)) == 0)
                        && (memcmp(&flow->l4.tcp.prev_zmq_pkt[1], p2, sizeof(p2)) == 0))) {
                ndpi_int_zmq_add_connection(ndpi_struct, flow);
                return;
            }
        }
    }
}

void ndpi_search_zmq(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 ZMQ\n");

    /* skip marked packets */
    if(packet->detected_protocol != NDPI_PROTOCOL_ZMQ) {
        if(packet->tcp && packet->tcp_retransmission == 0) {
            ndpi_check_zmq(ndpi_struct, flow);
        }
    }
}

void init_zmq_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
    ndpi_set_bitmask_protocol_detection("ZeroMQ", ndpi_struct, detection_bitmask, *id,
            NDPI_PROTOCOL_ZMQ,
            ndpi_search_zmq, /* TODO: add UDP support */
            NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_WITH_PAYLOAD_WITHOUT_RETRANSMISSION,
            SAVE_DETECTION_BITMASK_AS_UNKNOWN,
            ADD_TO_DETECTION_BITMASK);

    *id += 1;
}
