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