kernel/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
  24
  25 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr);
  26
  27 static __be16 raw_type_trans(struct sk_buff *skb, struct net_device *dev)
  28 {
  29         return cpu_to_be16(ETH_P_IP);
  30 }
  31
  32 static struct hdlc_proto proto = {
  33         .type_trans     = raw_type_trans,
  34         .ioctl          = raw_ioctl,
  35         .module         = THIS_MODULE,
  36 };
  37
  38
  39 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr)
  40 {
  41         raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
  42         const size_t size = sizeof(raw_hdlc_proto);
  43         raw_hdlc_proto new_settings;
  44         hdlc_device *hdlc = dev_to_hdlc(dev);
  45         int result;
  46
  47         switch (ifr->ifr_settings.type) {
  48         case IF_GET_PROTO:
  49                 if (dev_to_hdlc(dev)->proto != &proto)
  50                         return -EINVAL;
  51                 ifr->ifr_settings.type = IF_PROTO_HDLC;
  52                 if (ifr->ifr_settings.size < size) {
  53                         ifr->ifr_settings.size = size; /* data size wanted */
  54                         return -ENOBUFS;
  55                 }
  56                 if (copy_to_user(raw_s, hdlc->state, size))
  57                         return -EFAULT;
  58                 return 0;
  59
  60         case IF_PROTO_HDLC:
  61                 if (!capable(CAP_NET_ADMIN))
  62                         return -EPERM;
  63
  64                 if (dev->flags & IFF_UP)
  65                         return -EBUSY;
  66
  67                 if (copy_from_user(&new_settings, raw_s, size))
  68                         return -EFAULT;
  69
  70                 if (new_settings.encoding == ENCODING_DEFAULT)
  71                         new_settings.encoding = ENCODING_NRZ;
  72
  73                 if (new_settings.parity == PARITY_DEFAULT)
  74                         new_settings.parity = PARITY_CRC16_PR1_CCITT;
  75
  76                 result = hdlc->attach(dev, new_settings.encoding,
  77                                       new_settings.parity);
  78                 if (result)
  79                         return result;
  80
  81                 result = attach_hdlc_protocol(dev, &proto,
  82                                               sizeof(raw_hdlc_proto));
  83                 if (result)
  84                         return result;
  85                 memcpy(hdlc->state, &new_settings, size);
  86                 dev->type = ARPHRD_RAWHDLC;
  87                 netif_dormant_off(dev);
  88                 return 0;
  89         }
  90
  91         return -EINVAL;
  92 }
  93
  94
  95 static int __init mod_init(void)
  96 {
  97         register_hdlc_protocol(&proto);
  98         return 0;
  99 }
 100
 101
 102
 103 static void __exit mod_exit(void)
 104 {
 105         unregister_hdlc_protocol(&proto);
 106 }
 107
 108
 109 module_init(mod_init);
 110 module_exit(mod_exit);
 111
 112 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 113 MODULE_DESCRIPTION("Raw HDLC protocol support for generic HDLC");
 114 MODULE_LICENSE("GPL v2");