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