rose_timer.c

Go to the documentation of this file.

/*
 * 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.
 *
 * Copyright (C) Jonathan Naylor G4KLX ([email protected])
 * Copyright (C) 2002 Ralf Baechle DO1GRB ([email protected])
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/tcp_states.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/rose.h>

static void rose_heartbeat_expiry(unsigned long);
static void rose_timer_expiry(unsigned long);
static void rose_idletimer_expiry(unsigned long);

void rose_start_heartbeat(struct sock *sk)
{
    del_timer(&sk->sk_timer);

    sk->sk_timer.data     = (unsigned long)sk;
    sk->sk_timer.function = &rose_heartbeat_expiry;
    sk->sk_timer.expires  = jiffies + 5 * HZ;

    add_timer(&sk->sk_timer);
}

void rose_start_t1timer(struct sock *sk)
{
    struct rose_sock *rose = rose_sk(sk);

    del_timer(&rose->timer);

    rose->timer.data     = (unsigned long)sk;
    rose->timer.function = &rose_timer_expiry;
    rose->timer.expires  = jiffies + rose->t1;

    add_timer(&rose->timer);
}

void rose_start_t2timer(struct sock *sk)
{
    struct rose_sock *rose = rose_sk(sk);

    del_timer(&rose->timer);

    rose->timer.data     = (unsigned long)sk;
    rose->timer.function = &rose_timer_expiry;
    rose->timer.expires  = jiffies + rose->t2;

    add_timer(&rose->timer);
}

void rose_start_t3timer(struct sock *sk)
{
    struct rose_sock *rose = rose_sk(sk);

    del_timer(&rose->timer);

    rose->timer.data     = (unsigned long)sk;
    rose->timer.function = &rose_timer_expiry;
    rose->timer.expires  = jiffies + rose->t3;

    add_timer(&rose->timer);
}

void rose_start_hbtimer(struct sock *sk)
{
    struct rose_sock *rose = rose_sk(sk);

    del_timer(&rose->timer);

    rose->timer.data     = (unsigned long)sk;
    rose->timer.function = &rose_timer_expiry;
    rose->timer.expires  = jiffies + rose->hb;

    add_timer(&rose->timer);
}

void rose_start_idletimer(struct sock *sk)
{
    struct rose_sock *rose = rose_sk(sk);

    del_timer(&rose->idletimer);

    if (rose->idle > 0) {
        rose->idletimer.data     = (unsigned long)sk;
        rose->idletimer.function = &rose_idletimer_expiry;
        rose->idletimer.expires  = jiffies + rose->idle;

        add_timer(&rose->idletimer);
    }
}

void rose_stop_heartbeat(struct sock *sk)
{
    del_timer(&sk->sk_timer);
}

void rose_stop_timer(struct sock *sk)
{
    del_timer(&rose_sk(sk)->timer);
}

void rose_stop_idletimer(struct sock *sk)
{
    del_timer(&rose_sk(sk)->idletimer);
}

static void rose_heartbeat_expiry(unsigned long param)
{
    struct sock *sk = (struct sock *)param;
    struct rose_sock *rose = rose_sk(sk);

    bh_lock_sock(sk);
    switch (rose->state) {
    case ROSE_STATE_0:
        /* Magic here: If we listen() and a new link dies before it
           is accepted() it isn't 'dead' so doesn't get removed. */
        if (sock_flag(sk, SOCK_DESTROY) ||
            (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {
            bh_unlock_sock(sk);
            rose_destroy_socket(sk);
            return;
        }
        break;

    case ROSE_STATE_3:
        /*
         * Check for the state of the receive buffer.
         */
        if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
            (rose->condition & ROSE_COND_OWN_RX_BUSY)) {
            rose->condition &= ~ROSE_COND_OWN_RX_BUSY;
            rose->condition &= ~ROSE_COND_ACK_PENDING;
            rose->vl         = rose->vr;
            rose_write_internal(sk, ROSE_RR);
            rose_stop_timer(sk);    /* HB */
            break;
        }
        break;
    }

    rose_start_heartbeat(sk);
    bh_unlock_sock(sk);
}

static void rose_timer_expiry(unsigned long param)
{
    struct sock *sk = (struct sock *)param;
    struct rose_sock *rose = rose_sk(sk);

    bh_lock_sock(sk);
    switch (rose->state) {
    case ROSE_STATE_1:  /* T1 */
    case ROSE_STATE_4:  /* T2 */
        rose_write_internal(sk, ROSE_CLEAR_REQUEST);
        rose->state = ROSE_STATE_2;
        rose_start_t3timer(sk);
        break;

    case ROSE_STATE_2:  /* T3 */
        rose->neighbour->use--;
        rose_disconnect(sk, ETIMEDOUT, -1, -1);
        break;

    case ROSE_STATE_3:  /* HB */
        if (rose->condition & ROSE_COND_ACK_PENDING) {
            rose->condition &= ~ROSE_COND_ACK_PENDING;
            rose_enquiry_response(sk);
        }
        break;
    }
    bh_unlock_sock(sk);
}

static void rose_idletimer_expiry(unsigned long param)
{
    struct sock *sk = (struct sock *)param;

    bh_lock_sock(sk);
    rose_clear_queues(sk);

    rose_write_internal(sk, ROSE_CLEAR_REQUEST);
    rose_sk(sk)->state = ROSE_STATE_2;

    rose_start_t3timer(sk);

    sk->sk_state     = TCP_CLOSE;
    sk->sk_err       = 0;
    sk->sk_shutdown |= SEND_SHUTDOWN;

    if (!sock_flag(sk, SOCK_DEAD)) {
        sk->sk_state_change(sk);
        sock_set_flag(sk, SOCK_DEAD);
    }
    bh_unlock_sock(sk);
}