/*********************************************************************
 *
 * Filename:      ircomm_lmp.c
 * Version:       1.0
 * Description:   Interface between IrCOMM and IrLMP
 * Status:        Stable
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Sun Jun  6 20:48:27 1999
 * Modified at:   Sun Dec 12 13:44:17 1999
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 * Sources:       Previous IrLPT work by Thomas Davis
 *
 *     Copyright (c) 1999 Dag Brattli, All Rights Reserved.
 *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
 *
 *     This program is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 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 General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program; if not, see <http://www.gnu.org/licenses/>.
 *
 ********************************************************************/

#include <linux/init.h>
#include <linux/gfp.h>

#include <net/irda/irda.h>
#include <net/irda/irlmp.h>
#include <net/irda/iriap.h>
#include <net/irda/irda_device.h>       /* struct irda_skb_cb */

#include <net/irda/ircomm_event.h>
#include <net/irda/ircomm_lmp.h>


/*
 * Function ircomm_lmp_connect_request (self, userdata)
 *
 *
 *
 */
static int ircomm_lmp_connect_request(struct ircomm_cb *self,
                                      struct sk_buff *userdata,
                                      struct ircomm_info *info)
{
        int ret = 0;

        /* Don't forget to refcount it - should be NULL anyway */
        if(userdata)
                skb_get(userdata);

        ret = irlmp_connect_request(self->lsap, info->dlsap_sel,
                                    info->saddr, info->daddr, NULL, userdata);
        return ret;
}

/*
 * Function ircomm_lmp_connect_response (self, skb)
 *
 *
 *
 */
static int ircomm_lmp_connect_response(struct ircomm_cb *self,
                                       struct sk_buff *userdata)
{
        struct sk_buff *tx_skb;

        /* Any userdata supplied? */
        if (userdata == NULL) {
                tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
                if (!tx_skb)
                        return -ENOMEM;

                /* Reserve space for MUX and LAP header */
                skb_reserve(tx_skb, LMP_MAX_HEADER);
        } else {
                /*
                 *  Check that the client has reserved enough space for
                 *  headers
                 */
                IRDA_ASSERT(skb_headroom(userdata) >= LMP_MAX_HEADER,
                            return -1;);

                /* Don't forget to refcount it - should be NULL anyway */
                skb_get(userdata);
                tx_skb = userdata;
        }

        return irlmp_connect_response(self->lsap, tx_skb);
}

static int ircomm_lmp_disconnect_request(struct ircomm_cb *self,
                                         struct sk_buff *userdata,
                                         struct ircomm_info *info)
{
        struct sk_buff *tx_skb;
        int ret;

        if (!userdata) {
                tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
                if (!tx_skb)
                        return -ENOMEM;

                /*  Reserve space for MUX and LAP header */
                skb_reserve(tx_skb, LMP_MAX_HEADER);
                userdata = tx_skb;
        } else {
                /* Don't forget to refcount it - should be NULL anyway */
                skb_get(userdata);
        }

        ret = irlmp_disconnect_request(self->lsap, userdata);

        return ret;
}

/*
 * Function ircomm_lmp_flow_control (skb)
 *
 *    This function is called when a data frame we have sent to IrLAP has
 *    been deallocated. We do this to make sure we don't flood IrLAP with
 *    frames, since we are not using the IrTTP flow control mechanism
 */
static void ircomm_lmp_flow_control(struct sk_buff *skb)
{
        struct irda_skb_cb *cb;
        struct ircomm_cb *self;
        int line;

        IRDA_ASSERT(skb != NULL, return;);

        cb = (struct irda_skb_cb *) skb->cb;

        line = cb->line;

        self = (struct ircomm_cb *) hashbin_lock_find(ircomm, line, NULL);
        if (!self) {
                pr_debug("%s(), didn't find myself\n", __func__);
                return;
        }

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);

        self->pkt_count--;

        if ((self->pkt_count < 2) && (self->flow_status == FLOW_STOP)) {
                pr_debug("%s(), asking TTY to start again!\n", __func__);
                self->flow_status = FLOW_START;
                if (self->notify.flow_indication)
                        self->notify.flow_indication(self->notify.instance,
                                                     self, FLOW_START);
        }
}

/*
 * Function ircomm_lmp_data_request (self, userdata)
 *
 *    Send data frame to peer device
 *
 */
static int ircomm_lmp_data_request(struct ircomm_cb *self,
                                   struct sk_buff *skb,
                                   int not_used)
{
        struct irda_skb_cb *cb;
        int ret;

        IRDA_ASSERT(skb != NULL, return -1;);

        cb = (struct irda_skb_cb *) skb->cb;

        cb->line = self->line;

        pr_debug("%s(), sending frame\n", __func__);

        /* Don't forget to refcount it - see ircomm_tty_do_softint() */
        skb_get(skb);

        skb_orphan(skb);
        skb->destructor = ircomm_lmp_flow_control;

        if ((self->pkt_count++ > 7) && (self->flow_status == FLOW_START)) {
                pr_debug("%s(), asking TTY to slow down!\n", __func__);
                self->flow_status = FLOW_STOP;
                if (self->notify.flow_indication)
                        self->notify.flow_indication(self->notify.instance,
                                                     self, FLOW_STOP);
        }
        ret = irlmp_data_request(self->lsap, skb);
        if (ret) {
                net_err_ratelimited("%s(), failed\n", __func__);
                /* irlmp_data_request already free the packet */
        }

        return ret;
}

/*
 * Function ircomm_lmp_data_indication (instance, sap, skb)
 *
 *    Incoming data which we must deliver to the state machine, to check
 *    we are still connected.
 */
static int ircomm_lmp_data_indication(void *instance, void *sap,
                                      struct sk_buff *skb)
{
        struct ircomm_cb *self = (struct ircomm_cb *) instance;

        IRDA_ASSERT(self != NULL, return -1;);
        IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return -1;);
        IRDA_ASSERT(skb != NULL, return -1;);

        ircomm_do_event(self, IRCOMM_LMP_DATA_INDICATION, skb, NULL);

        /* Drop reference count - see ircomm_tty_data_indication(). */
        dev_kfree_skb(skb);

        return 0;
}

/*
 * Function ircomm_lmp_connect_confirm (instance, sap, qos, max_sdu_size,
 *                                       max_header_size, skb)
 *
 *    Connection has been confirmed by peer device
 *
 */
static void ircomm_lmp_connect_confirm(void *instance, void *sap,
                                       struct qos_info *qos,
                                       __u32 max_seg_size,
                                       __u8 max_header_size,
                                       struct sk_buff *skb)
{
        struct ircomm_cb *self = (struct ircomm_cb *) instance;
        struct ircomm_info info;

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
        IRDA_ASSERT(skb != NULL, return;);
        IRDA_ASSERT(qos != NULL, return;);

        info.max_data_size = max_seg_size;
        info.max_header_size = max_header_size;
        info.qos = qos;

        ircomm_do_event(self, IRCOMM_LMP_CONNECT_CONFIRM, skb, &info);

        /* Drop reference count - see ircomm_tty_connect_confirm(). */
        dev_kfree_skb(skb);
}

/*
 * Function ircomm_lmp_connect_indication (instance, sap, qos, max_sdu_size,
 *                                         max_header_size, skb)
 *
 *    Peer device wants to make a connection with us
 *
 */
static void ircomm_lmp_connect_indication(void *instance, void *sap,
                                          struct qos_info *qos,
                                          __u32 max_seg_size,
                                          __u8 max_header_size,
                                          struct sk_buff *skb)
{
        struct ircomm_cb *self = (struct ircomm_cb *)instance;
        struct ircomm_info info;

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);
        IRDA_ASSERT(skb != NULL, return;);
        IRDA_ASSERT(qos != NULL, return;);

        info.max_data_size = max_seg_size;
        info.max_header_size = max_header_size;
        info.qos = qos;

        ircomm_do_event(self, IRCOMM_LMP_CONNECT_INDICATION, skb, &info);

        /* Drop reference count - see ircomm_tty_connect_indication(). */
        dev_kfree_skb(skb);
}

/*
 * Function ircomm_lmp_disconnect_indication (instance, sap, reason, skb)
 *
 *    Peer device has closed the connection, or the link went down for some
 *    other reason
 */
static void ircomm_lmp_disconnect_indication(void *instance, void *sap,
                                             LM_REASON reason,
                                             struct sk_buff *skb)
{
        struct ircomm_cb *self = (struct ircomm_cb *) instance;
        struct ircomm_info info;

        IRDA_ASSERT(self != NULL, return;);
        IRDA_ASSERT(self->magic == IRCOMM_MAGIC, return;);

        info.reason = reason;

        ircomm_do_event(self, IRCOMM_LMP_DISCONNECT_INDICATION, skb, &info);

        /* Drop reference count - see ircomm_tty_disconnect_indication(). */
        if(skb)
                dev_kfree_skb(skb);
}
/*
 * Function ircomm_open_lsap (self)
 *
 *    Open LSAP. This function will only be used when using "raw" services
 *
 */
int ircomm_open_lsap(struct ircomm_cb *self)
{
        notify_t notify;

        /* Register callbacks */
        irda_notify_init(&notify);
        notify.data_indication       = ircomm_lmp_data_indication;
        notify.connect_confirm       = ircomm_lmp_connect_confirm;
        notify.connect_indication    = ircomm_lmp_connect_indication;
        notify.disconnect_indication = ircomm_lmp_disconnect_indication;
        notify.instance = self;
        strlcpy(notify.name, "IrCOMM", sizeof(notify.name));

        self->lsap = irlmp_open_lsap(LSAP_ANY, &notify, 0);
        if (!self->lsap) {
                pr_debug("%sfailed to allocate tsap\n", __func__);
                return -1;
        }
        self->slsap_sel = self->lsap->slsap_sel;

        /*
         *  Initialize the call-table for issuing commands
         */
        self->issue.data_request       = ircomm_lmp_data_request;
        self->issue.connect_request    = ircomm_lmp_connect_request;
        self->issue.connect_response   = ircomm_lmp_connect_response;
        self->issue.disconnect_request = ircomm_lmp_disconnect_request;

        return 0;
}