LXR linux/drivers/net/wan/hdlc_raw

   1/*
   2 * Generic HDLC support routines for Linux
   3 * HDLC Ethernet emulation support
   4 *
   5 * Copyright (C) 2002-2006 Krzysztof Halasa <khc@pm.waw.pl>
   6 *
   7 * This program is free software; you can redistribute it and/or modify it
   8 * under the terms of version 2 of the GNU General Public License
   9 * as published by the Free Software Foundation.
  10 */
  11
  12#include <linux/errno.h>
  13#include <linux/etherdevice.h>
  14#include <linux/hdlc.h>
  15#include <linux/if_arp.h>
  16#include <linux/inetdevice.h>
  17#include <linux/init.h>
  18#include <linux/kernel.h>
  19#include <linux/module.h>
  20#include <linux/pkt_sched.h>
  21#include <linux/poll.h>
  22#include <linux/rtnetlink.h>
  23#include <linux/skbuff.h>
  24#include <linux/slab.h>
  25
  26static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr);
  27
  28static netdev_tx_t eth_tx(struct sk_buff *skb, struct net_device *dev)
  29{
  30        int pad = ETH_ZLEN - skb->len;
  31        if (pad > 0) {          /* Pad the frame with zeros */
  32                int len = skb->len;
  33                if (skb_tailroom(skb) < pad)
  34                        if (pskb_expand_head(skb, 0, pad, GFP_ATOMIC)) {
  35                                dev->stats.tx_dropped++;
  36                                dev_kfree_skb(skb);
  37                                return 0;
  38                        }
  39                skb_put(skb, pad);
  40                memset(skb->data + len, 0, pad);
  41        }
  42        return dev_to_hdlc(dev)->xmit(skb, dev);
  43}
  44
  45
  46static struct hdlc_proto proto = {
  47        .type_trans     = eth_type_trans,
  48        .xmit           = eth_tx,
  49        .ioctl          = raw_eth_ioctl,
  50        .module         = THIS_MODULE,
  51};
  52
  53
  54static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr)
  55{
  56        raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
  57        const size_t size = sizeof(raw_hdlc_proto);
  58        raw_hdlc_proto new_settings;
  59        hdlc_device *hdlc = dev_to_hdlc(dev);
  60        int result, old_qlen;
  61
  62        switch (ifr->ifr_settings.type) {
  63        case IF_GET_PROTO:
  64                if (dev_to_hdlc(dev)->proto != &proto)
  65                        return -EINVAL;
  66                ifr->ifr_settings.type = IF_PROTO_HDLC_ETH;
  67                if (ifr->ifr_settings.size < size) {
  68                        ifr->ifr_settings.size = size; /* data size wanted */
  69                        return -ENOBUFS;
  70                }
  71                if (copy_to_user(raw_s, hdlc->state, size))
  72                        return -EFAULT;
  73                return 0;
  74
  75        case IF_PROTO_HDLC_ETH:
  76                if (!capable(CAP_NET_ADMIN))
  77                        return -EPERM;
  78
  79                if (dev->flags & IFF_UP)
  80                        return -EBUSY;
  81
  82                if (copy_from_user(&new_settings, raw_s, size))
  83                        return -EFAULT;
  84
  85                if (new_settings.encoding == ENCODING_DEFAULT)
  86                        new_settings.encoding = ENCODING_NRZ;
  87
  88                if (new_settings.parity == PARITY_DEFAULT)
  89                        new_settings.parity = PARITY_CRC16_PR1_CCITT;
  90
  91                result = hdlc->attach(dev, new_settings.encoding,
  92                                      new_settings.parity);
  93                if (result)
  94                        return result;
  95
  96                result = attach_hdlc_protocol(dev, &proto,
  97                                              sizeof(raw_hdlc_proto));
  98                if (result)
  99                        return result;
 100                memcpy(hdlc->state, &new_settings, size);
 101                old_qlen = dev->tx_queue_len;
 102                ether_setup(dev);
 103                dev->tx_queue_len = old_qlen;
 104                random_ether_addr(dev->dev_addr);
 105                netif_dormant_off(dev);
 106                return 0;
 107        }
 108
 109        return -EINVAL;
 110}
 111
 112
 113static int __init mod_init(void)
 114{
 115        register_hdlc_protocol(&proto);
 116        return 0;
 117}
 118
 119
 120
 121static void __exit mod_exit(void)
 122{
 123        unregister_hdlc_protocol(&proto);
 124}
 125
 126
 127module_init(mod_init);
 128module_exit(mod_exit);
 129
 130MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 131MODULE_DESCRIPTION("Ethernet encapsulation support for generic HDLC");
 132MODULE_LICENSE("GPL v2");
 133