/**
 * xrdp: A Remote Desktop Protocol server.
 *
 * Copyright (C) Jay Sorg 2004-2013
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * iso layer
 */

#include "libxrdp.h"

/*****************************************************************************/
struct xrdp_iso *APP_CC
xrdp_iso_create(struct xrdp_mcs *owner, struct trans *trans)
{
    struct xrdp_iso *self;

    DEBUG(("   in xrdp_iso_create"));
    self = (struct xrdp_iso *)g_malloc(sizeof(struct xrdp_iso), 1);
    self->mcs_layer = owner;
    self->tcp_layer = xrdp_tcp_create(self, trans);
    DEBUG(("   out xrdp_iso_create"));
    return self;
}

/*****************************************************************************/
void APP_CC
xrdp_iso_delete(struct xrdp_iso *self)
{
    if (self == 0)
    {
        return;
    }

    xrdp_tcp_delete(self->tcp_layer);
    g_free(self);
}

/*****************************************************************************/
/* returns error */
static int APP_CC
xrdp_iso_recv_msg(struct xrdp_iso *self, struct stream *s, int *code)
{
    int ver;
    int len;

    *code = 0;

    if (xrdp_tcp_recv(self->tcp_layer, s, 4) != 0)
    {
        return 1;
    }

    in_uint8(s, ver);

    if (ver != 3)
    {
        return 1;
    }

    in_uint8s(s, 1);
    in_uint16_be(s, len);

    if (len < 4)
    {
        return 1;
    }

    if (xrdp_tcp_recv(self->tcp_layer, s, len - 4) != 0)
    {
        return 1;
    }

    if (!s_check_rem(s, 2))
    {
        return 1;
    }

    in_uint8s(s, 1);
    in_uint8(s, *code);

    if (*code == ISO_PDU_DT)
    {
        if (!s_check_rem(s, 1))
        {
            return 1;
        }
        in_uint8s(s, 1);
    }
    else
    {
        if (!s_check_rem(s, 5))
        {
            return 1;
        }
        in_uint8s(s, 5);
    }

    return 0;
}

/*****************************************************************************/
/* returns error */
int APP_CC
xrdp_iso_recv(struct xrdp_iso *self, struct stream *s)
{
    int code;

    DEBUG(("   in xrdp_iso_recv"));

    if (xrdp_iso_recv_msg(self, s, &code) != 0)
    {
        DEBUG(("   out xrdp_iso_recv xrdp_iso_recv_msg return non zero"));
        return 1;
    }

    if (code != ISO_PDU_DT)
    {
        DEBUG(("   out xrdp_iso_recv code != ISO_PDU_DT"));
        return 1;
    }

    DEBUG(("   out xrdp_iso_recv"));
    return 0;
}

/*****************************************************************************/
static int APP_CC
xrdp_iso_send_msg(struct xrdp_iso *self, struct stream *s, int code)
{
    if (xrdp_tcp_init(self->tcp_layer, s) != 0)
    {
        return 1;
    }

    out_uint8(s, 3);
    out_uint8(s, 0);
    out_uint16_be(s, 11); /* length */
    out_uint8(s, 6);
    out_uint8(s, code);
    out_uint16_le(s, 0);
    out_uint16_le(s, 0);
    out_uint8(s, 0);
    s_mark_end(s);

    if (xrdp_tcp_send(self->tcp_layer, s) != 0)
    {
        return 1;
    }

    return 0;
}

/*****************************************************************************/
/* returns error */
int APP_CC
xrdp_iso_incoming(struct xrdp_iso *self)
{
    int code;
    struct stream *s;

    make_stream(s);
    init_stream(s, 8192);
    DEBUG(("   in xrdp_iso_incoming"));

    if (xrdp_iso_recv_msg(self, s, &code) != 0)
    {
        free_stream(s);
        return 1;
    }

    if (code != ISO_PDU_CR)
    {
        free_stream(s);
        return 1;
    }

    if (xrdp_iso_send_msg(self, s, ISO_PDU_CC) != 0)
    {
        free_stream(s);
        return 1;
    }

    DEBUG(("   out xrdp_iso_incoming"));
    free_stream(s);
    return 0;
}

/*****************************************************************************/
/* returns error */
int APP_CC
xrdp_iso_init(struct xrdp_iso *self, struct stream *s)
{
    xrdp_tcp_init(self->tcp_layer, s);
    s_push_layer(s, iso_hdr, 7);
    return 0;
}

/*****************************************************************************/
/* returns error */
int APP_CC
xrdp_iso_send(struct xrdp_iso *self, struct stream *s)
{
    int len;

    DEBUG(("   in xrdp_iso_send"));
    s_pop_layer(s, iso_hdr);
    len = s->end - s->p;
    out_uint8(s, 3);
    out_uint8(s, 0);
    out_uint16_be(s, len);
    out_uint8(s, 2);
    out_uint8(s, ISO_PDU_DT);
    out_uint8(s, 0x80);

    if (xrdp_tcp_send(self->tcp_layer, s) != 0)
    {
        return 1;
    }

    DEBUG(("   out xrdp_iso_send"));
    return 0;
}