linux-imx

/*

 *  X.25 Packet Layer release 002

 *

 *  This is ALPHA test software. This code may break your machine,

 *  randomly fail to work with new releases, misbehave and/or generally

 *  screw up. It might even work.

 *

 *  This code REQUIRES 2.1.15 or higher

 *

 *  This module:

 *      This module 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.

 *

 *  History

 *  X.25 001    Jonathan Naylor   Started coding.

 *  X.25 002    Jonathan Naylor   New timer architecture.

 *  mar/20/00   Daniela Squassoni Disabling/enabling of facilities

 *                    negotiation.

 *  2000-09-04  Henner Eisen      dev_hold() / dev_put() for x25_neigh.

 */

​

#define pr_fmt(fmt) "X25: " fmt

​

#include <linux/kernel.h>

#include <linux/jiffies.h>

#include <linux/timer.h>

#include <linux/slab.h>

#include <linux/netdevice.h>

#include <linux/skbuff.h>

#include <linux/uaccess.h>

#include <linux/init.h>

#include <net/x25.h>

​

LIST_HEAD(x25_neigh_list);

DEFINE_RWLOCK(x25_neigh_list_lock);

​

static void x25_t20timer_expiry(struct timer_list *);

​

static void x25_transmit_restart_confirmation(struct x25_neigh *nb);

static void x25_transmit_restart_request(struct x25_neigh *nb);

​

/*

 *  Linux set/reset timer routines

 */

static inline void x25_start_t20timer(struct x25_neigh *nb)

{

    mod_timer(&nb->t20timer, jiffies + nb->t20);

}

​

static void x25_t20timer_expiry(struct timer_list *t)

{

    struct x25_neigh *nb = from_timer(nb, t, t20timer);

​

    x25_transmit_restart_request(nb);

​

    x25_start_t20timer(nb);

}

​

static inline void x25_stop_t20timer(struct x25_neigh *nb)

{

    del_timer(&nb->t20timer);

}

​

static inline int x25_t20timer_pending(struct x25_neigh *nb)

{

    return timer_pending(&nb->t20timer);

}

​

/*

 *  This handles all restart and diagnostic frames.

 */

void x25_link_control(struct sk_buff *skb, struct x25_neigh *nb,

              unsigned short frametype)

{

    struct sk_buff *skbn;

    int confirm;

​

    switch (frametype) {

    case X25_RESTART_REQUEST:

        confirm = !x25_t20timer_pending(nb);

        x25_stop_t20timer(nb);

        nb->state = X25_LINK_STATE_3;

        if (confirm)

            x25_transmit_restart_confirmation(nb);

        break;

​

    case X25_RESTART_CONFIRMATION:

        x25_stop_t20timer(nb);

        nb->state = X25_LINK_STATE_3;

        break;