133 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			133 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Generic HDLC support routines for Linux
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 * HDLC Ethernet emulation support
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 *
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 * Copyright (C) 2002-2006 Krzysztof Halasa <khc@pm.waw.pl>
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 *
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 * This program is free software; you can redistribute it and/or modify it
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 * under the terms of version 2 of the GNU General Public License
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 * as published by the Free Software Foundation.
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 */
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#include <linux/errno.h>
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#include <linux/etherdevice.h>
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#include <linux/hdlc.h>
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#include <linux/if_arp.h>
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#include <linux/inetdevice.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/pkt_sched.h>
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#include <linux/poll.h>
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#include <linux/rtnetlink.h>
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#include <linux/skbuff.h>
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#include <linux/slab.h>
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static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr);
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static netdev_tx_t eth_tx(struct sk_buff *skb, struct net_device *dev)
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{
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	int pad = ETH_ZLEN - skb->len;
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	if (pad > 0) {		/* Pad the frame with zeros */
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		int len = skb->len;
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		if (skb_tailroom(skb) < pad)
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			if (pskb_expand_head(skb, 0, pad, GFP_ATOMIC)) {
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				dev->stats.tx_dropped++;
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				dev_kfree_skb(skb);
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				return 0;
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			}
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		skb_put(skb, pad);
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		memset(skb->data + len, 0, pad);
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	}
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	return dev_to_hdlc(dev)->xmit(skb, dev);
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}
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static struct hdlc_proto proto = {
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	.type_trans	= eth_type_trans,
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	.xmit		= eth_tx,
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	.ioctl		= raw_eth_ioctl,
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	.module		= THIS_MODULE,
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};
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static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr)
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{
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	raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
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	const size_t size = sizeof(raw_hdlc_proto);
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	raw_hdlc_proto new_settings;
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	hdlc_device *hdlc = dev_to_hdlc(dev);
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	int result, old_qlen;
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	switch (ifr->ifr_settings.type) {
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	case IF_GET_PROTO:
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		if (dev_to_hdlc(dev)->proto != &proto)
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			return -EINVAL;
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		ifr->ifr_settings.type = IF_PROTO_HDLC_ETH;
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		if (ifr->ifr_settings.size < size) {
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			ifr->ifr_settings.size = size; /* data size wanted */
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			return -ENOBUFS;
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		}
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		if (copy_to_user(raw_s, hdlc->state, size))
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			return -EFAULT;
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		return 0;
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	case IF_PROTO_HDLC_ETH:
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		if (!capable(CAP_NET_ADMIN))
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			return -EPERM;
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		if (dev->flags & IFF_UP)
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			return -EBUSY;
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		if (copy_from_user(&new_settings, raw_s, size))
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			return -EFAULT;
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		if (new_settings.encoding == ENCODING_DEFAULT)
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			new_settings.encoding = ENCODING_NRZ;
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		if (new_settings.parity == PARITY_DEFAULT)
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			new_settings.parity = PARITY_CRC16_PR1_CCITT;
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		result = hdlc->attach(dev, new_settings.encoding,
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				      new_settings.parity);
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		if (result)
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			return result;
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		result = attach_hdlc_protocol(dev, &proto,
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					      sizeof(raw_hdlc_proto));
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		if (result)
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			return result;
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		memcpy(hdlc->state, &new_settings, size);
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		old_qlen = dev->tx_queue_len;
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		ether_setup(dev);
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		dev->tx_queue_len = old_qlen;
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		random_ether_addr(dev->dev_addr);
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		netif_dormant_off(dev);
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		return 0;
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	}
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	return -EINVAL;
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}
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static int __init mod_init(void)
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{
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	register_hdlc_protocol(&proto);
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	return 0;
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}
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static void __exit mod_exit(void)
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{
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	unregister_hdlc_protocol(&proto);
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}
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module_init(mod_init);
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module_exit(mod_exit);
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MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
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MODULE_DESCRIPTION("Ethernet encapsulation support for generic HDLC");
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MODULE_LICENSE("GPL v2");
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