mirror of https://gitee.com/openkylin/linux.git
340 lines
7.1 KiB
C
340 lines
7.1 KiB
C
/*
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* Generic HDLC support routines for Linux
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*
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* Copyright (C) 1999 - 2005 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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* Currently supported:
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* * raw IP-in-HDLC
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* * Cisco HDLC
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* * Frame Relay with ANSI or CCITT LMI (both user and network side)
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* * PPP
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* * X.25
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*
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* Use sethdlc utility to set line parameters, protocol and PVCs
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*
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* How does it work:
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* - proto.open(), close(), start(), stop() calls are serialized.
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* The order is: open, [ start, stop ... ] close ...
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* - proto.start() and stop() are called with spin_lock_irq held.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/poll.h>
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#include <linux/errno.h>
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#include <linux/if_arp.h>
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#include <linux/init.h>
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#include <linux/skbuff.h>
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#include <linux/pkt_sched.h>
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#include <linux/inetdevice.h>
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#include <linux/lapb.h>
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#include <linux/rtnetlink.h>
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#include <linux/notifier.h>
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#include <linux/hdlc.h>
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static const char* version = "HDLC support module revision 1.19";
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#undef DEBUG_LINK
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static int hdlc_change_mtu(struct net_device *dev, int new_mtu)
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{
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if ((new_mtu < 68) || (new_mtu > HDLC_MAX_MTU))
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return -EINVAL;
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dev->mtu = new_mtu;
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return 0;
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}
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static struct net_device_stats *hdlc_get_stats(struct net_device *dev)
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{
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return hdlc_stats(dev);
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}
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static int hdlc_rcv(struct sk_buff *skb, struct net_device *dev,
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struct packet_type *p, struct net_device *orig_dev)
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{
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hdlc_device *hdlc = dev_to_hdlc(dev);
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if (hdlc->proto.netif_rx)
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return hdlc->proto.netif_rx(skb);
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hdlc->stats.rx_dropped++; /* Shouldn't happen */
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dev_kfree_skb(skb);
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return NET_RX_DROP;
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}
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static inline void hdlc_proto_start(struct net_device *dev)
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{
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hdlc_device *hdlc = dev_to_hdlc(dev);
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if (hdlc->proto.start)
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return hdlc->proto.start(dev);
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}
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static inline void hdlc_proto_stop(struct net_device *dev)
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{
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hdlc_device *hdlc = dev_to_hdlc(dev);
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if (hdlc->proto.stop)
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return hdlc->proto.stop(dev);
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}
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static int hdlc_device_event(struct notifier_block *this, unsigned long event,
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void *ptr)
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{
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struct net_device *dev = ptr;
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hdlc_device *hdlc;
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unsigned long flags;
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int on;
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if (dev->get_stats != hdlc_get_stats)
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return NOTIFY_DONE; /* not an HDLC device */
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if (event != NETDEV_CHANGE)
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return NOTIFY_DONE; /* Only interrested in carrier changes */
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on = netif_carrier_ok(dev);
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#ifdef DEBUG_LINK
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printk(KERN_DEBUG "%s: hdlc_device_event NETDEV_CHANGE, carrier %i\n",
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dev->name, on);
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#endif
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hdlc = dev_to_hdlc(dev);
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spin_lock_irqsave(&hdlc->state_lock, flags);
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if (hdlc->carrier == on)
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goto carrier_exit; /* no change in DCD line level */
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hdlc->carrier = on;
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if (!hdlc->open)
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goto carrier_exit;
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if (hdlc->carrier) {
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printk(KERN_INFO "%s: Carrier detected\n", dev->name);
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hdlc_proto_start(dev);
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} else {
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printk(KERN_INFO "%s: Carrier lost\n", dev->name);
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hdlc_proto_stop(dev);
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}
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carrier_exit:
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spin_unlock_irqrestore(&hdlc->state_lock, flags);
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return NOTIFY_DONE;
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}
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/* Must be called by hardware driver when HDLC device is being opened */
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int hdlc_open(struct net_device *dev)
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{
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hdlc_device *hdlc = dev_to_hdlc(dev);
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#ifdef DEBUG_LINK
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printk(KERN_DEBUG "hdlc_open() carrier %i open %i\n",
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hdlc->carrier, hdlc->open);
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#endif
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if (hdlc->proto.id == -1)
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return -ENOSYS; /* no protocol attached */
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if (hdlc->proto.open) {
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int result = hdlc->proto.open(dev);
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if (result)
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return result;
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}
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spin_lock_irq(&hdlc->state_lock);
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if (hdlc->carrier) {
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printk(KERN_INFO "%s: Carrier detected\n", dev->name);
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hdlc_proto_start(dev);
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} else
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printk(KERN_INFO "%s: No carrier\n", dev->name);
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hdlc->open = 1;
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spin_unlock_irq(&hdlc->state_lock);
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return 0;
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}
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/* Must be called by hardware driver when HDLC device is being closed */
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void hdlc_close(struct net_device *dev)
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{
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hdlc_device *hdlc = dev_to_hdlc(dev);
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#ifdef DEBUG_LINK
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printk(KERN_DEBUG "hdlc_close() carrier %i open %i\n",
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hdlc->carrier, hdlc->open);
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#endif
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spin_lock_irq(&hdlc->state_lock);
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hdlc->open = 0;
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if (hdlc->carrier)
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hdlc_proto_stop(dev);
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spin_unlock_irq(&hdlc->state_lock);
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if (hdlc->proto.close)
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hdlc->proto.close(dev);
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}
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#ifndef CONFIG_HDLC_RAW
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#define hdlc_raw_ioctl(dev, ifr) -ENOSYS
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#endif
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#ifndef CONFIG_HDLC_RAW_ETH
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#define hdlc_raw_eth_ioctl(dev, ifr) -ENOSYS
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#endif
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#ifndef CONFIG_HDLC_PPP
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#define hdlc_ppp_ioctl(dev, ifr) -ENOSYS
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#endif
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#ifndef CONFIG_HDLC_CISCO
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#define hdlc_cisco_ioctl(dev, ifr) -ENOSYS
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#endif
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#ifndef CONFIG_HDLC_FR
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#define hdlc_fr_ioctl(dev, ifr) -ENOSYS
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#endif
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#ifndef CONFIG_HDLC_X25
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#define hdlc_x25_ioctl(dev, ifr) -ENOSYS
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#endif
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int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
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{
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hdlc_device *hdlc = dev_to_hdlc(dev);
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unsigned int proto;
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if (cmd != SIOCWANDEV)
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return -EINVAL;
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switch(ifr->ifr_settings.type) {
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case IF_PROTO_HDLC:
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case IF_PROTO_HDLC_ETH:
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case IF_PROTO_PPP:
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case IF_PROTO_CISCO:
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case IF_PROTO_FR:
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case IF_PROTO_X25:
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proto = ifr->ifr_settings.type;
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break;
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default:
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proto = hdlc->proto.id;
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}
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switch(proto) {
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case IF_PROTO_HDLC: return hdlc_raw_ioctl(dev, ifr);
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case IF_PROTO_HDLC_ETH: return hdlc_raw_eth_ioctl(dev, ifr);
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case IF_PROTO_PPP: return hdlc_ppp_ioctl(dev, ifr);
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case IF_PROTO_CISCO: return hdlc_cisco_ioctl(dev, ifr);
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case IF_PROTO_FR: return hdlc_fr_ioctl(dev, ifr);
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case IF_PROTO_X25: return hdlc_x25_ioctl(dev, ifr);
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default: return -EINVAL;
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}
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}
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void hdlc_setup(struct net_device *dev)
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{
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hdlc_device *hdlc = dev_to_hdlc(dev);
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dev->get_stats = hdlc_get_stats;
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dev->change_mtu = hdlc_change_mtu;
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dev->mtu = HDLC_MAX_MTU;
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dev->type = ARPHRD_RAWHDLC;
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dev->hard_header_len = 16;
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dev->flags = IFF_POINTOPOINT | IFF_NOARP;
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hdlc->proto.id = -1;
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hdlc->proto.detach = NULL;
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hdlc->carrier = 1;
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hdlc->open = 0;
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spin_lock_init(&hdlc->state_lock);
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}
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struct net_device *alloc_hdlcdev(void *priv)
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{
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struct net_device *dev;
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dev = alloc_netdev(sizeof(hdlc_device), "hdlc%d", hdlc_setup);
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if (dev)
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dev_to_hdlc(dev)->priv = priv;
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return dev;
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}
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void unregister_hdlc_device(struct net_device *dev)
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{
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rtnl_lock();
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hdlc_proto_detach(dev_to_hdlc(dev));
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unregister_netdevice(dev);
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rtnl_unlock();
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}
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MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
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MODULE_DESCRIPTION("HDLC support module");
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MODULE_LICENSE("GPL v2");
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EXPORT_SYMBOL(hdlc_open);
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EXPORT_SYMBOL(hdlc_close);
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EXPORT_SYMBOL(hdlc_ioctl);
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EXPORT_SYMBOL(hdlc_setup);
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EXPORT_SYMBOL(alloc_hdlcdev);
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EXPORT_SYMBOL(unregister_hdlc_device);
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static struct packet_type hdlc_packet_type = {
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.type = __constant_htons(ETH_P_HDLC),
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.func = hdlc_rcv,
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};
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static struct notifier_block hdlc_notifier = {
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.notifier_call = hdlc_device_event,
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};
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static int __init hdlc_module_init(void)
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{
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int result;
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printk(KERN_INFO "%s\n", version);
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if ((result = register_netdevice_notifier(&hdlc_notifier)) != 0)
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return result;
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dev_add_pack(&hdlc_packet_type);
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return 0;
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}
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static void __exit hdlc_module_exit(void)
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{
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dev_remove_pack(&hdlc_packet_type);
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unregister_netdevice_notifier(&hdlc_notifier);
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}
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module_init(hdlc_module_init);
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module_exit(hdlc_module_exit);
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