/*
    en50221 encoder An implementation for libdvb
    an implementation for the en50221 transport layer

    Copyright (C) 2004, 2005 Manu Abraham (manu@kromtek.com)
    Copyright (C) 2005 Julian Scheel (julian at jusst dot de)
    Copyright (C) 2006 Andrew de Quincey (adq_dvb@lidskialf.net)

    This library 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 2.1 of
    the License, or (at your option) any later version.

    This program 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 this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
*/

#include <string.h>
#include <libdvbmisc/dvbmisc.h>
#include <pthread.h>
#include "en50221_app_auth.h"
#include "en50221_app_tags.h"
#include "asn_1.h"

struct en50221_app_auth_private {
        struct en50221_app_send_functions *funcs;

        en50221_app_auth_request_callback callback;
        void *callback_arg;

        pthread_mutex_t lock;
};

static int en50221_app_auth_parse_request(struct en50221_app_auth_private *private,
                                           uint8_t slot_id, uint16_t session_number,
                                           uint8_t *data, uint32_t data_length);


en50221_app_auth en50221_app_auth_create(struct en50221_app_send_functions *funcs)
{
    struct en50221_app_auth_private *private = NULL;

    // create structure and set it up
    private = malloc(sizeof(struct en50221_app_auth_private));
    if (private == NULL) {
        return NULL;
    }
    private->funcs = funcs;
    private->callback = NULL;

    pthread_mutex_init(&private->lock, NULL);

    // done
    return private;
}

void en50221_app_auth_destroy(en50221_app_auth auth)
{
    struct en50221_app_auth_private *private = (struct en50221_app_auth_private *) auth;

    pthread_mutex_destroy(&private->lock);
    free(private);
}

void en50221_app_auth_register_request_callback(en50221_app_auth auth,
                                                en50221_app_auth_request_callback callback, void *arg)
{
    struct en50221_app_auth_private *private = (struct en50221_app_auth_private *) auth;

    pthread_mutex_lock(&private->lock);
    private->callback = callback;
    private->callback_arg = arg;
    pthread_mutex_unlock(&private->lock);
}

int en50221_app_auth_send(en50221_app_auth auth,
                          uint16_t session_number,
                          uint16_t auth_protocol_id, uint8_t *auth_data,
                          uint32_t auth_data_length)
{
    struct en50221_app_auth_private *private = (struct en50221_app_auth_private *) auth;
    uint8_t buf[10];

    // the header
    buf[0] = (TAG_AUTH_RESP >> 16) & 0xFF;
    buf[1] = (TAG_AUTH_RESP >> 8) & 0xFF;
    buf[2] = TAG_AUTH_RESP & 0xFF;

    // encode the length field
    int length_field_len;
    if ((length_field_len = asn_1_encode(auth_data_length+2, buf+3, 3)) < 0) {
        return -1;
    }

    // the phase_id
    buf[3+length_field_len] = auth_protocol_id>>8;
    buf[3+length_field_len+1] = auth_protocol_id;

    // build the iovecs
    struct iovec iov[2];
    iov[0].iov_base = buf;
    iov[0].iov_len = 3+length_field_len+2;
    iov[1].iov_base = auth_data;
    iov[1].iov_len = auth_data_length;

    // sendit
    return private->funcs->send_datav(private->funcs->arg, session_number, iov, 2);
}

int en50221_app_auth_message(en50221_app_auth auth,
                             uint8_t slot_id,
                             uint16_t session_number,
                             uint32_t resource_id,
                             uint8_t *data, uint32_t data_length)
{
    struct en50221_app_auth_private *private = (struct en50221_app_auth_private *) auth;
    (void) resource_id;

    // get the tag
    if (data_length < 3) {
        print(LOG_LEVEL, ERROR, 1, "Received short data\n");
        return -1;
    }
    uint32_t tag = (data[0] << 16) | (data[1] << 8) | data[2];

    switch(tag)
    {
        case TAG_AUTH_REQ:
            return en50221_app_auth_parse_request(private, slot_id, session_number, data+3, data_length-3);
    }

    print(LOG_LEVEL, ERROR, 1, "Received unexpected tag %x\n", tag);
    return -1;
}



static int en50221_app_auth_parse_request(struct en50221_app_auth_private *private,
                                           uint8_t slot_id, uint16_t session_number,
                                           uint8_t *data, uint32_t data_length)
{
    // first of all, decode the length field
    uint16_t asn_data_length;
    int length_field_len;
    if ((length_field_len = asn_1_decode(&asn_data_length, data, data_length)) < 0) {
        print(LOG_LEVEL, ERROR, 1, "ASN.1 decode error\n");
        return -1;
    }

    // check it
    if (asn_data_length < 2) {
        print(LOG_LEVEL, ERROR, 1, "Received short data\n");
        return -1;
    }
    if (asn_data_length > (data_length-length_field_len)) {
        print(LOG_LEVEL, ERROR, 1, "Received short data\n");
        return -1;
    }
    uint8_t *auth_data = data + length_field_len;

    // process it
    uint16_t auth_protocol_id = (auth_data[0]<<8) | auth_data[1];

    // tell the app
    pthread_mutex_lock(&private->lock);
    en50221_app_auth_request_callback cb = private->callback;
    void *cb_arg = private->callback_arg;
    pthread_mutex_unlock(&private->lock);
    if (cb) {
        return cb(cb_arg, slot_id, session_number, auth_protocol_id, auth_data+2, asn_data_length-2);
    }
    return 0;
}
