drivers/net/wan/hdlc_raw_eth.c

   1 /*
   2  * Generic HDLC support routines for Linux
   3  * HDLC Ethernet emulation support
   4  *
   5  * Copyright (C) 2002-2003 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/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/poll.h>
  16 #include <linux/errno.h>
  17 #include <linux/if_arp.h>
  18 #include <linux/init.h>
  19 #include <linux/skbuff.h>
  20 #include <linux/pkt_sched.h>
  21 #include <linux/random.h>
  22 #include <linux/inetdevice.h>
  23 #include <linux/lapb.h>
  24 #include <linux/rtnetlink.h>
  25 #include <linux/etherdevice.h>
  26 #include <linux/hdlc.h>
  27
  28
  29 static int eth_tx(struct sk_buff *skb, struct net_device *dev)
  30 {
  31         int pad = ETH_ZLEN - skb->len;
  32         if (pad > 0) {          /* Pad the frame with zeros */
  33                 int len = skb->len;
  34                 if (skb_tailroom(skb) < pad)
  35                         if (pskb_expand_head(skb, 0, pad, GFP_ATOMIC)) {
  36                                 hdlc_stats(dev)->tx_dropped++;
  37                                 dev_kfree_skb(skb);
  38                                 return 0;
  39                         }
  40                 skb_put(skb, pad);
  41                 memset(skb->data + len, 0, pad);
  42         }
  43         return dev_to_hdlc(dev)->xmit(skb, dev);
  44 }
  45
  46
  47 int hdlc_raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr)
  48 {
  49         raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
  50         const size_t size = sizeof(raw_hdlc_proto);
  51         raw_hdlc_proto new_settings;
  52         hdlc_device *hdlc = dev_to_hdlc(dev);
  53         int result;
  54         void *old_ch_mtu;
  55         int old_qlen;
  56
  57         switch (ifr->ifr_settings.type) {
  58         case IF_GET_PROTO:
  59                 ifr->ifr_settings.type = IF_PROTO_HDLC_ETH;
  60                 if (ifr->ifr_settings.size < size) {
  61                         ifr->ifr_settings.size = size; /* data size wanted */
  62                         return -ENOBUFS;
  63                 }
  64                 if (copy_to_user(raw_s, &hdlc->state.raw_hdlc.settings, size))
  65                         return -EFAULT;
  66                 return 0;
  67
  68         case IF_PROTO_HDLC_ETH:
  69                 if (!capable(CAP_NET_ADMIN))
  70                         return -EPERM;
  71
  72                 if (dev->flags & IFF_UP)
  73                         return -EBUSY;
  74
  75                 if (copy_from_user(&new_settings, raw_s, size))
  76                         return -EFAULT;
  77
  78                 if (new_settings.encoding == ENCODING_DEFAULT)
  79                         new_settings.encoding = ENCODING_NRZ;
  80
  81                 if (new_settings.parity == PARITY_DEFAULT)
  82                         new_settings.parity = PARITY_CRC16_PR1_CCITT;
  83
  84                 result = hdlc->attach(dev, new_settings.encoding,
  85                                       new_settings.parity);
  86                 if (result)
  87                         return result;
  88
  89                 hdlc_proto_detach(hdlc);
  90                 memcpy(&hdlc->state.raw_hdlc.settings, &new_settings, size);
  91                 memset(&hdlc->proto, 0, sizeof(hdlc->proto));
  92
  93                 hdlc->proto.type_trans = eth_type_trans;
  94                 hdlc->proto.id = IF_PROTO_HDLC_ETH;
  95                 dev->hard_start_xmit = eth_tx;
  96                 old_ch_mtu = dev->change_mtu;
  97                 old_qlen = dev->tx_queue_len;
  98                 ether_setup(dev);
  99                 dev->change_mtu = old_ch_mtu;
 100                 dev->tx_queue_len = old_qlen;
 101                 memcpy(dev->dev_addr, "\x00\x01", 2);
 102                 get_random_bytes(dev->dev_addr + 2, ETH_ALEN - 2);
 103                 return 0;
 104         }
 105
 106         return -EINVAL;
 107 }