hdlc_raw.c

一个2.4.21版本的嵌入式linux内核

/*
 * Generic HDLC support routines for Linux
 * HDLC support
 *
 * Copyright (C) 1999 - 2001 Krzysztof Halasa <[e-mail]>
 *
 * 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.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/pkt_sched.h>
#include <linux/inetdevice.h>
#include <linux/lapb.h>
#include <linux/rtnetlink.h>
#include <linux/hdlc.h>


static void raw_rx(struct sk_buff *skb)
{
	skb->protocol = htons(ETH_P_IP);
	netif_rx(skb);
}



int hdlc_raw_ioctl(hdlc_device *hdlc, struct ifreq *ifr)
{
	raw_hdlc_proto *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
	const size_t size = sizeof(raw_hdlc_proto);
	raw_hdlc_proto new_settings;
	struct net_device *dev = hdlc_to_dev(hdlc);
	int result;

	switch (ifr->ifr_settings.type) {
	case IF_GET_PROTO:
		ifr->ifr_settings.type = IF_PROTO_HDLC;
		if (ifr->ifr_settings.size < size) {
			ifr->ifr_settings.size = size; /* data size wanted */
			return -ENOBUFS;
		}
		if (copy_to_user(raw_s, &hdlc->state.raw_hdlc.settings, size))
			return -EFAULT;
		return 0;

	case IF_PROTO_HDLC:
		if (!capable(CAP_NET_ADMIN))
			return -EPERM;

		if (dev->flags & IFF_UP)
			return -EBUSY;

		if (copy_from_user(&new_settings, raw_s, size))
			return -EFAULT;

		if (new_settings.encoding == ENCODING_DEFAULT)
			new_settings.encoding = ENCODING_NRZ;

		if (new_settings.parity == PARITY_DEFAULT)
			new_settings.parity = PARITY_NONE;

		result = hdlc->attach(hdlc, new_settings.encoding,
				      new_settings.parity);
		if (result)
			return result;

		hdlc_proto_detach(hdlc);
		memcpy(&hdlc->state.raw_hdlc.settings, &new_settings, size);

		hdlc->open = NULL;
		hdlc->stop = NULL;
		hdlc->netif_rx = raw_rx;
		hdlc->proto = IF_PROTO_HDLC;
		dev->hard_start_xmit = hdlc->xmit;
		dev->hard_header = NULL;
		dev->type = ARPHRD_RAWHDLC;
		dev->addr_len = 0;
		return 0;
	}

	return -EINVAL;
}