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![Andrew Lunn](/assets/img/avatar_default.png)
An HDLC device can change type when the protocol driver is changed. Calling the notifier change allows potential users of the interface know about this planned change, and even block it. After the change has occurred, send a second notification to users can evaluate the new device type etc. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
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/gfp.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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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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eth_hw_addr_random(dev);
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call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
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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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