linux-imx

/* drivers/atm/atmtcp.c - ATM over TCP "device" driver */

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/* Written 1997-2000 by Werner Almesberger, EPFL LRC/ICA */

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#include <linux/module.h>

#include <linux/wait.h>

#include <linux/atmdev.h>

#include <linux/atm_tcp.h>

#include <linux/bitops.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/uaccess.h>

#include <linux/atomic.h>

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extern int atm_init_aal5(struct atm_vcc *vcc); /* "raw" AAL5 transport */

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#define PRIV(dev) ((struct atmtcp_dev_data *) ((dev)->dev_data))

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struct atmtcp_dev_data {

    struct atm_vcc *vcc;    /* control VCC; NULL if detached */

    int persist;        /* non-zero if persistent */

};

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#define DEV_LABEL    "atmtcp"

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#define MAX_VPI_BITS  8 /* simplifies life */

#define MAX_VCI_BITS 16

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/*

 * Hairy code ahead: the control VCC may be closed while we're still

 * waiting for an answer, so we need to re-validate out_vcc every once

 * in a while.

 */

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static int atmtcp_send_control(struct atm_vcc *vcc,int type,

    const struct atmtcp_control *msg,int flag)

{

    DECLARE_WAITQUEUE(wait,current);

    struct atm_vcc *out_vcc;

    struct sk_buff *skb;

    struct atmtcp_control *new_msg;

    int old_test;

    int error = 0;

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    out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;

    if (!out_vcc) return -EUNATCH;

    skb = alloc_skb(sizeof(*msg),GFP_KERNEL);

    if (!skb) return -ENOMEM;

    mb();

    out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;

    if (!out_vcc) {

        dev_kfree_skb(skb);

        return -EUNATCH;

    }

    atm_force_charge(out_vcc,skb->truesize);

    new_msg = skb_put(skb, sizeof(*new_msg));

    *new_msg = *msg;

    new_msg->hdr.length = ATMTCP_HDR_MAGIC;

    new_msg->type = type;

    memset(&new_msg->vcc,0,sizeof(atm_kptr_t));

    *(struct atm_vcc **) &new_msg->vcc = vcc;

    old_test = test_bit(flag,&vcc->flags);

    out_vcc->push(out_vcc,skb);

    add_wait_queue(sk_sleep(sk_atm(vcc)), &wait);

    while (test_bit(flag,&vcc->flags) == old_test) {

        mb();

        out_vcc = PRIV(vcc->dev) ? PRIV(vcc->dev)->vcc : NULL;

        if (!out_vcc) {

            error = -EUNATCH;

            break;

        }

        set_current_state(TASK_UNINTERRUPTIBLE);

        schedule();

    }

    set_current_state(TASK_RUNNING);

    remove_wait_queue(sk_sleep(sk_atm(vcc)), &wait);

    return error;

}

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static int atmtcp_recv_control(const struct atmtcp_control *msg)

{

    struct atm_vcc *vcc = *(struct atm_vcc **) &msg->vcc;

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    vcc->vpi = msg->addr.sap_addr.vpi;