xref: /openbmc/linux/drivers/net/wan/hdlc_raw.c (revision cfbb9be8)
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 
24 
25 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr);
26 
27 static __be16 raw_type_trans(struct sk_buff *skb, struct net_device *dev)
28 {
29 	return cpu_to_be16(ETH_P_IP);
30 }
31 
32 static struct hdlc_proto proto = {
33 	.type_trans	= raw_type_trans,
34 	.ioctl		= raw_ioctl,
35 	.module		= THIS_MODULE,
36 };
37 
38 
39 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr)
40 {
41 	raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
42 	const size_t size = sizeof(raw_hdlc_proto);
43 	raw_hdlc_proto new_settings;
44 	hdlc_device *hdlc = dev_to_hdlc(dev);
45 	int result;
46 
47 	switch (ifr->ifr_settings.type) {
48 	case IF_GET_PROTO:
49 		if (dev_to_hdlc(dev)->proto != &proto)
50 			return -EINVAL;
51 		ifr->ifr_settings.type = IF_PROTO_HDLC;
52 		if (ifr->ifr_settings.size < size) {
53 			ifr->ifr_settings.size = size; /* data size wanted */
54 			return -ENOBUFS;
55 		}
56 		if (copy_to_user(raw_s, hdlc->state, size))
57 			return -EFAULT;
58 		return 0;
59 
60 	case IF_PROTO_HDLC:
61 		if (!capable(CAP_NET_ADMIN))
62 			return -EPERM;
63 
64 		if (dev->flags & IFF_UP)
65 			return -EBUSY;
66 
67 		if (copy_from_user(&new_settings, raw_s, size))
68 			return -EFAULT;
69 
70 		if (new_settings.encoding == ENCODING_DEFAULT)
71 			new_settings.encoding = ENCODING_NRZ;
72 
73 		if (new_settings.parity == PARITY_DEFAULT)
74 			new_settings.parity = PARITY_CRC16_PR1_CCITT;
75 
76 		result = hdlc->attach(dev, new_settings.encoding,
77 				      new_settings.parity);
78 		if (result)
79 			return result;
80 
81 		result = attach_hdlc_protocol(dev, &proto,
82 					      sizeof(raw_hdlc_proto));
83 		if (result)
84 			return result;
85 		memcpy(hdlc->state, &new_settings, size);
86 		dev->type = ARPHRD_RAWHDLC;
87 		call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
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");
116