ax25_dev.c

嵌入式系统设计与实例开发实验教材二源码 多线程应用程序设计 串行端口程序设计 AD接口实验 CAN总线通信实验 GPS通信实验 Linux内核移植与编译实验 IC卡读写实验 SD驱动使

/*
 *	AX.25 release 037
 *
 *	This code REQUIRES 2.1.15 or higher/ NET3.038
 *
 *	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.
 *
 *	Other kernels modules in this kit are generally BSD derived. See the copyright headers.
 *
 *
 *	History
 *	AX.25 036	Jonathan(G4KLX)	Split from ax25_route.c.
 */

#include <linux/config.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.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/if_arp.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/init.h>

ax25_dev *ax25_dev_list;

ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
{
	ax25_dev *ax25_dev;

	for (ax25_dev = ax25_dev_list; ax25_dev != NULL; ax25_dev = ax25_dev->next)
		if (ax25_dev->dev == dev)
			return ax25_dev;

	return NULL;
}

ax25_dev *ax25_addr_ax25dev(ax25_address *addr)
{
	ax25_dev *ax25_dev;

	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)
			return ax25_dev;

	return NULL;
}

/*
 *	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;
	unsigned long flags;

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

	ax25_unregister_sysctl();

	memset(ax25_dev, 0x00, sizeof(*ax25_dev));

	ax25_dev->dev     = 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;

	save_flags(flags); cli();
	ax25_dev->next = ax25_dev_list;
	ax25_dev_list  = ax25_dev;
	restore_flags(flags);

	ax25_register_sysctl();
}

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

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

	ax25_unregister_sysctl();

	save_flags(flags); cli();

#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;
		restore_flags(flags);
		kfree(ax25_dev);
		ax25_register_sysctl();
		return;
	}

	while (s != NULL && s->next != NULL) {
		if (s->next == ax25_dev) {
			s->next = ax25_dev->next;
			restore_flags(flags);
			kfree(ax25_dev);
			ax25_register_sysctl();
			return;
		}

		s = s->next;
	}

	restore_flags(flags);
	ax25_register_sysctl();
}

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 = ax25_dev_list;

	while (ax25_dev != NULL) {
		s        = ax25_dev;
		ax25_dev = ax25_dev->next;

		kfree(s);
	}
}