ax25_dev.c

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/*
 * 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 (g4klx@g4klx.demon.co.uk)
 */
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/slab.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/spinlock.h>
#include <net/ax25.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/init.h>

ax25_dev *ax25_dev_list;
DEFINE_SPINLOCK(ax25_dev_lock);

ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
{
    ax25_dev *ax25_dev, *res = NULL;

    spin_lock_bh(&ax25_dev_lock);
    for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
        if (ax25cmp(addr, (ax25_address *)ax25_dev->dev->dev_addr) == 0) {
            res = ax25_dev;
        }
    spin_unlock_bh(&ax25_dev_lock);

    return res;
}

/*
 *  This is called when an interface is brought up. These are
 *  reasonable defaults.
 */
void ax25_dev_device_up(struct net_device *dev)
{
    ax25_dev *ax25_dev;

    if ((ax25_dev = kzalloc(sizeof(*ax25_dev), GFP_ATOMIC)) == NULL) {
        printk(KERN_ERR "AX.25: ax25_dev_device_up - out of memory\n");
        return;
    }

    dev->ax25_ptr     = ax25_dev;
    ax25_dev->dev     = dev;
    dev_hold(dev);
    ax25_dev->forward = NULL;

    ax25_dev->values[AX25_VALUES_IPDEFMODE] = AX25_DEF_IPDEFMODE;
    ax25_dev->values[AX25_VALUES_AXDEFMODE] = AX25_DEF_AXDEFMODE;
    ax25_dev->values[AX25_VALUES_BACKOFF]   = AX25_DEF_BACKOFF;
    ax25_dev->values[AX25_VALUES_CONMODE]   = AX25_DEF_CONMODE;
    ax25_dev->values[AX25_VALUES_WINDOW]    = AX25_DEF_WINDOW;
    ax25_dev->values[AX25_VALUES_EWINDOW]   = AX25_DEF_EWINDOW;
    ax25_dev->values[AX25_VALUES_T1]        = AX25_DEF_T1;
    ax25_dev->values[AX25_VALUES_T2]        = AX25_DEF_T2;
    ax25_dev->values[AX25_VALUES_T3]        = AX25_DEF_T3;
    ax25_dev->values[AX25_VALUES_IDLE]  = AX25_DEF_IDLE;
    ax25_dev->values[AX25_VALUES_N2]        = AX25_DEF_N2;
    ax25_dev->values[AX25_VALUES_PACLEN]    = AX25_DEF_PACLEN;
    ax25_dev->values[AX25_VALUES_PROTOCOL]  = AX25_DEF_PROTOCOL;
    ax25_dev->values[AX25_VALUES_DS_TIMEOUT]= AX25_DEF_DS_TIMEOUT;

#if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
    ax25_ds_setup_timer(ax25_dev);
#endif

    spin_lock_bh(&ax25_dev_lock);
    ax25_dev->next = ax25_dev_list;
    ax25_dev_list  = ax25_dev;
    spin_unlock_bh(&ax25_dev_lock);

    ax25_register_dev_sysctl(ax25_dev);
}

void ax25_dev_device_down(struct net_device *dev)
{
    ax25_dev *s, *ax25_dev;

    if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
        return;

    ax25_unregister_dev_sysctl(ax25_dev);

    spin_lock_bh(&ax25_dev_lock);

#ifdef CONFIG_AX25_DAMA_SLAVE
    ax25_ds_del_timer(ax25_dev);
#endif

    /*
     *  Remove any packet forwarding that points to this device.
     */
    for (s = ax25_dev_list; s != NULL; s = s->next)
        if (s->forward == dev)
            s->forward = NULL;

    if ((s = ax25_dev_list) == ax25_dev) {
        ax25_dev_list = s->next;
        spin_unlock_bh(&ax25_dev_lock);
        dev_put(dev);
        kfree(ax25_dev);
        return;
    }

    while (s != NULL && s->next != NULL) {
        if (s->next == ax25_dev) {
            s->next = ax25_dev->next;
            spin_unlock_bh(&ax25_dev_lock);
            dev_put(dev);
            kfree(ax25_dev);
            return;
        }

        s = s->next;
    }
    spin_unlock_bh(&ax25_dev_lock);
    dev->ax25_ptr = NULL;
}

int ax25_fwd_ioctl(unsigned int cmd, struct ax25_fwd_struct *fwd)
{
    ax25_dev *ax25_dev, *fwd_dev;

    if ((ax25_dev = ax25_addr_ax25dev(&fwd->port_from)) == NULL)
        return -EINVAL;

    switch (cmd) {
    case SIOCAX25ADDFWD:
        if ((fwd_dev = ax25_addr_ax25dev(&fwd->port_to)) == NULL)
            return -EINVAL;
        if (ax25_dev->forward != NULL)
            return -EINVAL;
        ax25_dev->forward = fwd_dev->dev;
        break;

    case SIOCAX25DELFWD:
        if (ax25_dev->forward == NULL)
            return -EINVAL;
        ax25_dev->forward = NULL;
        break;

    default:
        return -EINVAL;
    }

    return 0;
}

struct net_device *ax25_fwd_dev(struct net_device *dev)
{
    ax25_dev *ax25_dev;

    if ((ax25_dev = ax25_dev_ax25dev(dev)) == NULL)
        return dev;

    if (ax25_dev->forward == NULL)
        return dev;

    return ax25_dev->forward;
}

/*
 *  Free all memory associated with device structures.
 */
void __exit ax25_dev_free(void)
{
    ax25_dev *s, *ax25_dev;

    spin_lock_bh(&ax25_dev_lock);
    ax25_dev = ax25_dev_list;
    while (ax25_dev != NULL) {
        s        = ax25_dev;
        dev_put(ax25_dev->dev);
        ax25_dev = ax25_dev->next;
        kfree(s);
    }
    ax25_dev_list = NULL;
    spin_unlock_bh(&ax25_dev_lock);
}