LXR linux/drivers/net/wan/hdlc

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Generic HDLC support routines for Linux
   4 * HDLC support
   5 *
   6 * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
   7 */
   8
   9#include <linux/errno.h>
  10#include <linux/hdlc.h>
  11#include <linux/if_arp.h>
  12#include <linux/inetdevice.h>
  13#include <linux/init.h>
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/pkt_sched.h>
  17#include <linux/poll.h>
  18#include <linux/rtnetlink.h>
  19#include <linux/skbuff.h>
  20
  21
  22static int raw_ioctl(struct net_device *dev, struct if_settings *ifs);
  23
  24static __be16 raw_type_trans(struct sk_buff *skb, struct net_device *dev)
  25{
  26        return cpu_to_be16(ETH_P_IP);
  27}
  28
  29static struct hdlc_proto proto = {
  30        .type_trans     = raw_type_trans,
  31        .ioctl          = raw_ioctl,
  32        .module         = THIS_MODULE,
  33};
  34
  35
  36static int raw_ioctl(struct net_device *dev, struct if_settings *ifs)
  37{
  38        raw_hdlc_proto __user *raw_s = ifs->ifs_ifsu.raw_hdlc;
  39        const size_t size = sizeof(raw_hdlc_proto);
  40        raw_hdlc_proto new_settings;
  41        hdlc_device *hdlc = dev_to_hdlc(dev);
  42        int result;
  43
  44        switch (ifs->type) {
  45        case IF_GET_PROTO:
  46                if (dev_to_hdlc(dev)->proto != &proto)
  47                        return -EINVAL;
  48                ifs->type = IF_PROTO_HDLC;
  49                if (ifs->size < size) {
  50                        ifs->size = size; /* data size wanted */
  51                        return -ENOBUFS;
  52                }
  53                if (copy_to_user(raw_s, hdlc->state, size))
  54                        return -EFAULT;
  55                return 0;
  56
  57        case IF_PROTO_HDLC:
  58                if (!capable(CAP_NET_ADMIN))
  59                        return -EPERM;
  60
  61                if (dev->flags & IFF_UP)
  62                        return -EBUSY;
  63
  64                if (copy_from_user(&new_settings, raw_s, size))
  65                        return -EFAULT;
  66
  67                if (new_settings.encoding == ENCODING_DEFAULT)
  68                        new_settings.encoding = ENCODING_NRZ;
  69
  70                if (new_settings.parity == PARITY_DEFAULT)
  71                        new_settings.parity = PARITY_CRC16_PR1_CCITT;
  72
  73                result = hdlc->attach(dev, new_settings.encoding,
  74                                      new_settings.parity);
  75                if (result)
  76                        return result;
  77
  78                result = attach_hdlc_protocol(dev, &proto,
  79                                              sizeof(raw_hdlc_proto));
  80                if (result)
  81                        return result;
  82                memcpy(hdlc->state, &new_settings, size);
  83                dev->type = ARPHRD_RAWHDLC;
  84                call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
  85                netif_dormant_off(dev);
  86                return 0;
  87        }
  88
  89        return -EINVAL;
  90}
  91
  92
  93static int __init hdlc_raw_init(void)
  94{
  95        register_hdlc_protocol(&proto);
  96        return 0;
  97}
  98
  99
 100
 101static void __exit hdlc_raw_exit(void)
 102{
 103        unregister_hdlc_protocol(&proto);
 104}
 105
 106
 107module_init(hdlc_raw_init);
 108module_exit(hdlc_raw_exit);
 109
 110MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
 111MODULE_DESCRIPTION("Raw HDLC protocol support for generic HDLC");
 112MODULE_LICENSE("GPL v2");
 113