linux-imx

// SPDX-License-Identifier: GPL-2.0

/* net/atm/svc.c - ATM SVC sockets */

​

/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */

​

#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

​

#include <linux/string.h>

#include <linux/net.h>      /* struct socket, struct proto_ops */

#include <linux/errno.h>    /* error codes */

#include <linux/kernel.h>   /* printk */

#include <linux/skbuff.h>

#include <linux/wait.h>

#include <linux/sched/signal.h>

#include <linux/fcntl.h>    /* O_NONBLOCK */

#include <linux/init.h>

#include <linux/atm.h>      /* ATM stuff */

#include <linux/atmsap.h>

#include <linux/atmsvc.h>

#include <linux/atmdev.h>

#include <linux/bitops.h>

#include <net/sock.h>       /* for sock_no_* */

#include <linux/uaccess.h>

#include <linux/export.h>

​

#include "resources.h"

#include "common.h"     /* common for PVCs and SVCs */

#include "signaling.h"

#include "addr.h"

​

static int svc_create(struct net *net, struct socket *sock, int protocol,

              int kern);

​

/*

 * Note: since all this is still nicely synchronized with the signaling demon,

 *       there's no need to protect sleep loops with clis. If signaling is

 *       moved into the kernel, that would change.

 */

​

​

static int svc_shutdown(struct socket *sock, int how)

{

    return 0;

}

​

static void svc_disconnect(struct atm_vcc *vcc)

{

    DEFINE_WAIT(wait);

    struct sk_buff *skb;

    struct sock *sk = sk_atm(vcc);

​

    pr_debug("%p\n", vcc);

    if (test_bit(ATM_VF_REGIS, &vcc->flags)) {

        sigd_enq(vcc, as_close, NULL, NULL, NULL);

        for (;;) {

            prepare_to_wait(sk_sleep(sk), &wait, TASK_UNINTERRUPTIBLE);

            if (test_bit(ATM_VF_RELEASED, &vcc->flags) || !sigd)

                break;

            schedule();

        }

        finish_wait(sk_sleep(sk), &wait);

    }

    /* beware - socket is still in use by atmsigd until the last

       as_indicate has been answered */

    while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {

        atm_return(vcc, skb->truesize);

        pr_debug("LISTEN REL\n");

        sigd_enq2(NULL, as_reject, vcc, NULL, NULL, &vcc->qos, 0);

        dev_kfree_skb(skb);

    }

    clear_bit(ATM_VF_REGIS, &vcc->flags);

    /* ... may retry later */

}

​

static int svc_release(struct socket *sock)

{

    struct sock *sk = sock->sk;

    struct atm_vcc *vcc;

​

    if (sk) {

        vcc = ATM_SD(sock);

        pr_debug("%p\n", vcc);

        clear_bit(ATM_VF_READY, &vcc->flags);

        /*

         * VCC pointer is used as a reference,

         * so we must not free it (thereby subjecting it to re-use)

         * before all pending connections are closed

         */

        svc_disconnect(vcc);

        vcc_release(sock);

    }

    return 0;