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
22 static int raw_ioctl(struct net_device *dev, struct if_settings *ifs);
23
raw_type_trans(struct sk_buff * skb,struct net_device * dev)24 static __be16 raw_type_trans(struct sk_buff *skb, struct net_device *dev)
25 {
26 return cpu_to_be16(ETH_P_IP);
27 }
28
29 static struct hdlc_proto proto = {
30 .type_trans = raw_type_trans,
31 .ioctl = raw_ioctl,
32 .module = THIS_MODULE,
33 };
34
35
raw_ioctl(struct net_device * dev,struct if_settings * ifs)36 static 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
hdlc_raw_init(void)93 static int __init hdlc_raw_init(void)
94 {
95 register_hdlc_protocol(&proto);
96 return 0;
97 }
98
99
100
hdlc_raw_exit(void)101 static void __exit hdlc_raw_exit(void)
102 {
103 unregister_hdlc_protocol(&proto);
104 }
105
106
107 module_init(hdlc_raw_init);
108 module_exit(hdlc_raw_exit);
109
110 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
111 MODULE_DESCRIPTION("Raw HDLC protocol support for generic HDLC");
112 MODULE_LICENSE("GPL v2");
113