/* * Generic HDLC support routines for Linux * HDLC Ethernet emulation support * * Copyright (C) 2002-2003 Krzysztof Halasa <khc@pm.waw.pl> * * This program is free software; you can redistribute it and/or modify it * under the terms of version 2 of the GNU General Public License * as published by the Free Software Foundation. */#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/random.h>#include <linux/inetdevice.h>#include <linux/lapb.h>#include <linux/rtnetlink.h>#include <linux/etherdevice.h>#include <linux/hdlc.h>static int eth_tx(struct sk_buff *skb, struct net_device *dev){	int pad = ETH_ZLEN - skb->len;	if (pad > 0) {		/* Pad the frame with zeros */		int len = skb->len;		if (skb_tailroom(skb) < pad)			if (pskb_expand_head(skb, 0, pad, GFP_ATOMIC)) {				hdlc_stats(dev)->tx_dropped++;				dev_kfree_skb(skb);				return 0;			}		skb_put(skb, pad);		memset(skb->data + len, 0, pad);	}	return dev_to_hdlc(dev)->xmit(skb, dev);}int hdlc_raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr){	raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;	const size_t size = sizeof(raw_hdlc_proto);	raw_hdlc_proto new_settings;	hdlc_device *hdlc = dev_to_hdlc(dev);	int result;	void *old_ch_mtu;	int old_qlen;	switch (ifr->ifr_settings.type) {	case IF_GET_PROTO:		ifr->ifr_settings.type = IF_PROTO_HDLC_ETH;		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_ETH:		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_CRC16_PR1_CCITT;		result = hdlc->attach(dev, new_settings.encoding,				      new_settings.parity);		if (result)			return result;		hdlc_proto_detach(hdlc);		memcpy(&hdlc->state.raw_hdlc.settings, &new_settings, size);		memset(&hdlc->proto, 0, sizeof(hdlc->proto));		hdlc->proto.type_trans = eth_type_trans;		hdlc->proto.id = IF_PROTO_HDLC_ETH;		dev->hard_start_xmit = eth_tx;		old_ch_mtu = dev->change_mtu;		old_qlen = dev->tx_queue_len;		ether_setup(dev);		dev->change_mtu = old_ch_mtu;		dev->tx_queue_len = old_qlen;		memcpy(dev->dev_addr, "\x00\x01", 2);                get_random_bytes(dev->dev_addr + 2, ETH_ALEN - 2);		return 0;	}	return -EINVAL;}