drivers/net/wan/hdlc_raw.c

   1 /*
   2  * Generic HDLC support routines for Linux
   3  * HDLC support
   4  *
   5  * Copyright (C) 1999 - 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/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/inetdevice.h>
  22 #include <linux/lapb.h>
  23 #include <linux/rtnetlink.h>
  24 #include <linux/hdlc.h>
  25
  26
  27 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr);
  28
  29 static __be16 raw_type_trans(struct sk_buff *skb, struct net_device *dev)
  30 {
  31         return __constant_htons(ETH_P_IP);
  32 }
  33
  34
  35
  36 static struct hdlc_proto proto = {
  37         .type_trans     = raw_type_trans,
  38         .ioctl          = raw_ioctl,
  39         .module         = THIS_MODULE,
  40 };
  41
  42
  43 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr)
  44 {
  45         raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
  46         const size_t size = sizeof(raw_hdlc_proto);
  47         raw_hdlc_proto new_settings;
  48         hdlc_device *hdlc = dev_to_hdlc(dev);
  49         int result;
  50
  51         switch (ifr->ifr_settings.type) {
  52         case IF_GET_PROTO:
  53                 if (dev_to_hdlc(dev)->proto != &proto)
  54                         return -EINVAL;
  55                 ifr->ifr_settings.type = IF_PROTO_HDLC;
  56                 if (ifr->ifr_settings.size < size) {
  57                         ifr->ifr_settings.size = size; /* data size wanted */
  58                         return -ENOBUFS;
  59                 }
  60                 if (copy_to_user(raw_s, hdlc->state, size))
  61                         return -EFAULT;
  62                 return 0;
  63
  64         case IF_PROTO_HDLC:
  65                 if (!capable(CAP_NET_ADMIN))
  66                         return -EPERM;
  67
  68                 if (dev->flags & IFF_UP)
  69                         return -EBUSY;
  70
  71                 if (copy_from_user(&new_settings, raw_s, size))
  72                         return -EFAULT;
  73
  74                 if (new_settings.encoding == ENCODING_DEFAULT)
  75                         new_settings.encoding = ENCODING_NRZ;
  76
  77                 if (new_settings.parity == PARITY_DEFAULT)
  78                         new_settings.parity = PARITY_CRC16_PR1_CCITT;
  79
  80                 result = hdlc->attach(dev, new_settings.encoding,
  81                                       new_settings.parity);
  82                 if (result)
  83                         return result;
  84
  85                 result = attach_hdlc_protocol(dev, &proto,
  86                                               sizeof(raw_hdlc_proto));
  87                 if (result)
  88                         return result;
  89                 memcpy(hdlc->state, &new_settings, size);
  90                 dev->hard_start_xmit = hdlc->xmit;
  91                 dev->type = ARPHRD_RAWHDLC;
  92                 netif_dormant_off(dev);
  93                 return 0;
  94         }
  95
  96         return -EINVAL;
  97 }
  98
  99
 100 static int __init mod_init(void)
 101 {
 102         register_hdlc_protocol(&proto);
 103         return 0;
 104 }
 105
 106
 107
 108 static void __exit mod_exit(void)
 109 {
 110         unregister_hdlc_protocol(&proto);
 111 }
 112
 113
 114 module_init(mod_init);
 115 module_exit(mod_exit);
 116
 117 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 118 MODULE_DESCRIPTION("Raw HDLC protocol support for generic HDLC");
 119 MODULE_LICENSE("GPL v2");