drivers/net/wan/hdlc_raw.c

   1 /*
   2  * Generic HDLC support routines for Linux
   3  * HDLC support
   4  *
   5  * Copyright (C) 1999 - 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/inetdevice.h>
  22 #include <linux/lapb.h>
  23 #include <linux/rtnetlink.h>
  24 #include <linux/hdlc.h>
  25
  26
  27 static unsigned short raw_type_trans(struct sk_buff *skb,
  28                                      struct net_device *dev)
  29 {
  30         return __constant_htons(ETH_P_IP);
  31 }
  32
  33
  34
  35 int hdlc_raw_ioctl(struct net_device *dev, struct ifreq *ifr)
  36 {
  37         raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
  38         const size_t size = sizeof(raw_hdlc_proto);
  39         raw_hdlc_proto new_settings;
  40         hdlc_device *hdlc = dev_to_hdlc(dev);
  41         int result;
  42
  43         switch (ifr->ifr_settings.type) {
  44         case IF_GET_PROTO:
  45                 ifr->ifr_settings.type = IF_PROTO_HDLC;
  46                 if (ifr->ifr_settings.size < size) {
  47                         ifr->ifr_settings.size = size; /* data size wanted */
  48                         return -ENOBUFS;
  49                 }
  50                 if (copy_to_user(raw_s, &hdlc->state.raw_hdlc.settings, size))
  51                         return -EFAULT;
  52                 return 0;
  53
  54         case IF_PROTO_HDLC:
  55                 if (!capable(CAP_NET_ADMIN))
  56                         return -EPERM;
  57
  58                 if (dev->flags & IFF_UP)
  59                         return -EBUSY;
  60
  61                 if (copy_from_user(&new_settings, raw_s, size))
  62                         return -EFAULT;
  63
  64                 if (new_settings.encoding == ENCODING_DEFAULT)
  65                         new_settings.encoding = ENCODING_NRZ;
  66
  67                 if (new_settings.parity == PARITY_DEFAULT)
  68                         new_settings.parity = PARITY_CRC16_PR1_CCITT;
  69
  70                 result = hdlc->attach(dev, new_settings.encoding,
  71                                       new_settings.parity);
  72                 if (result)
  73                         return result;
  74
  75                 hdlc_proto_detach(hdlc);
  76                 memcpy(&hdlc->state.raw_hdlc.settings, &new_settings, size);
  77                 memset(&hdlc->proto, 0, sizeof(hdlc->proto));
  78
  79                 hdlc->proto.type_trans = raw_type_trans;
  80                 hdlc->proto.id = IF_PROTO_HDLC;
  81                 dev->hard_start_xmit = hdlc->xmit;
  82                 dev->hard_header = NULL;
  83                 dev->type = ARPHRD_RAWHDLC;
  84                 dev->flags = IFF_POINTOPOINT | IFF_NOARP;
  85                 dev->addr_len = 0;
  86                 return 0;
  87         }
  88
  89         return -EINVAL;
  90 }