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