ircomm_lmp.c

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/*********************************************************************
 *
 * Filename:      ircomm_lmp.c
 * Version:       1.0
 * Description:   Interface between IrCOMM and IrLMP
 * Status:        Stable
 * Author:        Dag Brattli <[email protected]>
 * Created at:    Sun Jun  6 20:48:27 1999
 * Modified at:   Sun Dec 12 13:44:17 1999
 * Modified by:   Dag Brattli <[email protected]>
 * Sources:       Previous IrLPT work by Thomas Davis
 *
 *     Copyright (c) 1999 Dag Brattli, All Rights Reserved.
 *     Copyright (c) 2000-2003 Jean Tourrilhes <[email protected]>
 *
 *     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, write to the Free Software
 *     Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *     MA 02111-1307 USA
 *
 ********************************************************************/

#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;

    IRDA_DEBUG(0, "%s()\n", __func__ );

    /* 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;

    IRDA_DEBUG(0, "%s()\n", __func__ );

    /* 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;

    IRDA_DEBUG(0, "%s()\n", __func__ );

    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;

    IRDA_DEBUG(2, "%s()\n", __func__ );

    line = cb->line;

    self = (struct ircomm_cb *) hashbin_lock_find(ircomm, line, NULL);
    if (!self) {
        IRDA_DEBUG(2, "%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)) {
        IRDA_DEBUG(2, "%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;

    IRDA_DEBUG(4, "%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)) {
        IRDA_DEBUG(2, "%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) {
        IRDA_ERROR("%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_DEBUG(4, "%s()\n", __func__ );

    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_DEBUG(0, "%s()\n", __func__ );

    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_DEBUG(0, "%s()\n", __func__ );

    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_DEBUG(0, "%s()\n", __func__ );

    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;

    IRDA_DEBUG(0, "%s()\n", __func__ );

    /* 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) {
        IRDA_DEBUG(0,"%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;
}