/*
 * jabber.c
 *
 * Copyright (C) 2009-2011 by ipoque GmbH
 * Copyright (C) 2011-18 - 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"

#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_UNENCRYPTED_JABBER

#include "ndpi_api.h"

struct jabber_string {
    char *string;
    u_int ndpi_protocol;
};

static struct jabber_string jabber_strings[] = {
    { "='im.truphone.com'",     NDPI_PROTOCOL_TRUPHONE },
    { "=\"im.truphone.com\"",   NDPI_PROTOCOL_TRUPHONE },
    { NULL, 0 }
};

static void ndpi_int_jabber_add_connection(struct ndpi_detection_module_struct *ndpi_struct,
        struct ndpi_flow_struct *flow,
        u_int32_t protocol)
{
    ndpi_set_detected_protocol(ndpi_struct, flow, protocol);
}

static void check_content_type_and_change_protocol(struct ndpi_detection_module_struct *ndpi_struct,
        struct ndpi_flow_struct *flow, u_int16_t x)
{
    struct ndpi_packet_struct *packet = &flow->packet;
    int i, left = packet->payload_packet_len-x;

    if(left <= 0) return;

    for(i=0; jabber_strings[i].string != NULL; i++) {
        if(ndpi_strnstr((const char*)&packet->payload[x], jabber_strings[i].string, left) != NULL) {
            ndpi_int_jabber_add_connection(ndpi_struct, flow, jabber_strings[i].ndpi_protocol);
            return;
        }
    }
}

void ndpi_search_jabber_tcp(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
    struct ndpi_packet_struct *packet = &flow->packet;
    struct ndpi_id_struct *src = flow->src;
    struct ndpi_id_struct *dst = flow->dst;

    u_int16_t x;

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

    /* search for jabber file transfer */
    /* this part is working asymmetrically */
    if (packet->tcp != NULL && packet->tcp->syn != 0 && packet->payload_packet_len == 0) {
        NDPI_LOG_DBG2(ndpi_struct, "check jabber syn\n");
        if (src != NULL && src->jabber_file_transfer_port[0] != 0) {
            NDPI_LOG_DBG2(ndpi_struct, "src jabber ft port set, ports are: %u, %u\n",
                    ntohs(src->jabber_file_transfer_port[0]),
                    ntohs(src->jabber_file_transfer_port[1]));
            if (((u_int32_t)
                        (packet->tick_timestamp - src->jabber_stun_or_ft_ts)) >= ndpi_struct->jabber_file_transfer_timeout) {
                NDPI_LOG_DBG2(ndpi_struct, "JABBER src stun timeout %u %u\n",
                        src->jabber_stun_or_ft_ts, packet->tick_timestamp);
                src->jabber_file_transfer_port[0] = 0;
                src->jabber_file_transfer_port[1] = 0;
            } else if (src->jabber_file_transfer_port[0] == packet->tcp->dest
                    || src->jabber_file_transfer_port[0] == packet->tcp->source
                    || src->jabber_file_transfer_port[1] == packet->tcp->dest
                    || src->jabber_file_transfer_port[1] == packet->tcp->source) {
                NDPI_LOG_INFO(ndpi_struct, "found jabber file transfer\n");

                ndpi_int_jabber_add_connection(ndpi_struct, flow,
                        NDPI_PROTOCOL_UNENCRYPTED_JABBER);
            }
        }
        if (dst != NULL && dst->jabber_file_transfer_port[0] != 0) {
            NDPI_LOG_DBG2(ndpi_struct, "dst jabber ft port set, ports are: %u, %u\n",
                    ntohs(dst->jabber_file_transfer_port[0]),
                    ntohs(dst->jabber_file_transfer_port[1]));
            if (((u_int32_t)
                        (packet->tick_timestamp - dst->jabber_stun_or_ft_ts)) >= ndpi_struct->jabber_file_transfer_timeout) {
                NDPI_LOG_DBG2(ndpi_struct, "JABBER dst stun timeout %u %u\n",
                        dst->jabber_stun_or_ft_ts, packet->tick_timestamp);
                dst->jabber_file_transfer_port[0] = 0;
                dst->jabber_file_transfer_port[1] = 0;
            } else if (dst->jabber_file_transfer_port[0] == packet->tcp->dest
                    || dst->jabber_file_transfer_port[0] == packet->tcp->source
                    || dst->jabber_file_transfer_port[1] == packet->tcp->dest
                    || dst->jabber_file_transfer_port[1] == packet->tcp->source) {
                NDPI_LOG_INFO(ndpi_struct, "found jabber file transfer\n");

                ndpi_int_jabber_add_connection(ndpi_struct, flow,
                        NDPI_PROTOCOL_UNENCRYPTED_JABBER);
            }
        }
        return;
    }

    if (packet->tcp != 0 && packet->payload_packet_len == 0) {
        return;
    }


    /* this part parses a packet and searches for port=. it works asymmetrically. */
    if (packet->detected_protocol == NDPI_PROTOCOL_UNENCRYPTED_JABBER) {
        u_int16_t lastlen;
        u_int16_t j_port = 0;
        /* check for google jabber voip connections ... */
        /* need big packet */
        if (packet->payload_packet_len < 100) {
            NDPI_LOG_DBG2(ndpi_struct, "packet too small, return\n");
            return;
        }
        /* need message to or type for file-transfer */
        if (memcmp(packet->payload, "<iq from=\"", 8) == 0 || memcmp(packet->payload, "<iq from=\'", 8) == 0) {
            NDPI_LOG_DBG2(ndpi_struct, "JABBER <iq from=\"\n");
            lastlen = packet->payload_packet_len - 11;
            for (x = 10; x < lastlen; x++) {
                if (packet->payload[x] == 'p') {
                    if (memcmp(&packet->payload[x], "port=", 5) == 0) {
                        NDPI_LOG_DBG2(ndpi_struct, "port=\n");
                        if (src != NULL) {
                            src->jabber_stun_or_ft_ts = packet->tick_timestamp;
                        }

                        if (dst != NULL) {
                            dst->jabber_stun_or_ft_ts = packet->tick_timestamp;
                        }
                        x += 6;
                        j_port = ntohs_ndpi_bytestream_to_number(&packet->payload[x], packet->payload_packet_len, &x);
                        NDPI_LOG_DBG2(ndpi_struct, "JABBER port : %u\n", ntohs(j_port));
                        if (src != NULL) {
                            if (src->jabber_file_transfer_port[0] == 0 || src->jabber_file_transfer_port[0] == j_port) {
                                NDPI_LOG_DBG2(ndpi_struct, "src->jabber_file_transfer_port[0] = j_port = %u;\n",
                                        ntohs(j_port));
                                src->jabber_file_transfer_port[0] = j_port;
                            } else {
                                NDPI_LOG_DBG2(ndpi_struct, "src->jabber_file_transfer_port[1] = j_port = %u;\n",
                                        ntohs(j_port));
                                src->jabber_file_transfer_port[1] = j_port;
                            }
                        }
                        if (dst != NULL) {
                            if (dst->jabber_file_transfer_port[0] == 0 || dst->jabber_file_transfer_port[0] == j_port) {
                                NDPI_LOG_DBG2(ndpi_struct, "dst->jabber_file_transfer_port[0] = j_port = %u;\n",
                                        ntohs(j_port));
                                dst->jabber_file_transfer_port[0] = j_port;
                            } else {
                                NDPI_LOG_DBG2(ndpi_struct, "dst->jabber_file_transfer_port[1] = j_port = %u;\n",
                                        ntohs(j_port));
                                dst->jabber_file_transfer_port[1] = j_port;
                            }
                        }
                    }


                }
            }

        } else if (memcmp(packet->payload, "<iq to=\"", 8) == 0 || memcmp(packet->payload, "<iq to=\'", 8) == 0
                || memcmp(packet->payload, "<iq type=", 9) == 0) {
            NDPI_LOG_DBG2(ndpi_struct, "JABBER <iq to=\"/type=\"\n");
            lastlen = packet->payload_packet_len - 21;
            for (x = 8; x < lastlen; x++) {
                /* invalid character */
                if (packet->payload[x] < 32 || packet->payload[x] > 127) {
                    return;
                }
                if (packet->payload[x] == '@') {
                    NDPI_LOG_DBG2(ndpi_struct, "JABBER @\n");
                    break;
                }
            }
            if (x >= lastlen) {
                return;
            }

            lastlen = packet->payload_packet_len - 10;
            for (; x < lastlen; x++) {
                if (packet->payload[x] == 'p') {
                    if (memcmp(&packet->payload[x], "port=", 5) == 0) {
                        NDPI_LOG_DBG2(ndpi_struct, "port=\n");
                        if (src != NULL) {
                            src->jabber_stun_or_ft_ts = packet->tick_timestamp;
                        }

                        if (dst != NULL) {
                            dst->jabber_stun_or_ft_ts = packet->tick_timestamp;
                        }

                        x += 6;
                        j_port = ntohs_ndpi_bytestream_to_number(&packet->payload[x], packet->payload_packet_len, &x);
                        NDPI_LOG_DBG2(ndpi_struct, "JABBER port : %u\n", ntohs(j_port));

                        if (src != NULL && src->jabber_voice_stun_used_ports < JABBER_MAX_STUN_PORTS - 1) {
                            if (packet->payload[5] == 'o') {
                                src->jabber_voice_stun_port[src->jabber_voice_stun_used_ports++]
                                    = j_port;
                            } else {
                                if (src->jabber_file_transfer_port[0] == 0
                                        || src->jabber_file_transfer_port[0] == j_port) {
                                    NDPI_LOG_DBG2(ndpi_struct, "src->jabber_file_transfer_port[0] = j_port = %u;\n",
                                            ntohs(j_port));
                                    src->jabber_file_transfer_port[0] = j_port;
                                } else {
                                    NDPI_LOG_DBG2(ndpi_struct, "src->jabber_file_transfer_port[1] = j_port = %u;\n",
                                            ntohs(j_port));
                                    src->jabber_file_transfer_port[1] = j_port;
                                }
                            }
                        }

                        if (dst != NULL && dst->jabber_voice_stun_used_ports < JABBER_MAX_STUN_PORTS - 1) {
                            if (packet->payload[5] == 'o') {
                                dst->jabber_voice_stun_port[dst->jabber_voice_stun_used_ports++]
                                    = j_port;
                            } else {
                                if (dst->jabber_file_transfer_port[0] == 0
                                        || dst->jabber_file_transfer_port[0] == j_port) {
                                    NDPI_LOG_DBG2(ndpi_struct, "dst->jabber_file_transfer_port[0] = j_port = %u;\n",
                                            ntohs(j_port));
                                    dst->jabber_file_transfer_port[0] = j_port;
                                } else {
                                    NDPI_LOG_DBG2(ndpi_struct, "dst->jabber_file_transfer_port[1] = j_port = %u;\n",
                                            ntohs(j_port));
                                    dst->jabber_file_transfer_port[1] = j_port;
                                }
                            }
                        }
                        return;
                    }
                }
            }
        }
        return;
    }


    /* search for jabber here */
    /* this part is working asymmetrically */
    if ((packet->payload_packet_len > 13 && memcmp(packet->payload, "<?xml version=", 14) == 0)
            || (packet->payload_packet_len >= NDPI_STATICSTRING_LEN("<stream:stream ")
                && memcmp(packet->payload, "<stream:stream ", NDPI_STATICSTRING_LEN("<stream:stream ")) == 0)) {
        int start = packet->payload_packet_len-13;

        if(ndpi_strnstr((const char *)&packet->payload[13], "xmlns:stream='http://etherx.jabber.org/streams'", start)
                || ndpi_strnstr((const char *)&packet->payload[13], "xmlns:stream=\"http://etherx.jabber.org/streams\"", start)) {

            /* Protocol family */
            ndpi_int_jabber_add_connection(ndpi_struct, flow, NDPI_PROTOCOL_UNENCRYPTED_JABBER);

            /* search for subprotocols */
            check_content_type_and_change_protocol(ndpi_struct, flow, 13);
            return;
        }
    }

    if (flow->packet_counter < 3) {
        NDPI_LOG_DBG2(ndpi_struct, "packet_counter: %u\n", flow->packet_counter);
        return;
    }

    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);

    ndpi_exclude_protocol(ndpi_struct, flow, NDPI_PROTOCOL_TRUPHONE,
            __FILE__,__FUNCTION__,__LINE__);
}


void init_jabber_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
    ndpi_set_bitmask_protocol_detection("Unencrypted_Jabber", ndpi_struct, detection_bitmask, *id,
            NDPI_PROTOCOL_UNENCRYPTED_JABBER,
            ndpi_search_jabber_tcp,
            NDPI_SELECTION_BITMASK_PROTOCOL_V4_V6_TCP_OR_UDP_WITHOUT_RETRANSMISSION,
            SAVE_DETECTION_BITMASK_AS_UNKNOWN,
            ADD_TO_DETECTION_BITMASK);

    *id += 1;
}

