xref: /openbmc/linux/drivers/net/wan/hdlc_raw.c (revision 22246614)
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/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 int raw_ioctl(struct net_device *dev, struct ifreq *ifr);
28 
29 static __be16 raw_type_trans(struct sk_buff *skb, struct net_device *dev)
30 {
31 	return __constant_htons(ETH_P_IP);
32 }
33 
34 
35 
36 static struct hdlc_proto proto = {
37 	.type_trans	= raw_type_trans,
38 	.ioctl		= raw_ioctl,
39 	.module		= THIS_MODULE,
40 };
41 
42 
43 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr)
44 {
45 	raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
46 	const size_t size = sizeof(raw_hdlc_proto);
47 	raw_hdlc_proto new_settings;
48 	hdlc_device *hdlc = dev_to_hdlc(dev);
49 	int result;
50 
51 	switch (ifr->ifr_settings.type) {
52 	case IF_GET_PROTO:
53 		if (dev_to_hdlc(dev)->proto != &proto)
54 			return -EINVAL;
55 		ifr->ifr_settings.type = IF_PROTO_HDLC;
56 		if (ifr->ifr_settings.size < size) {
57 			ifr->ifr_settings.size = size; /* data size wanted */
58 			return -ENOBUFS;
59 		}
60 		if (copy_to_user(raw_s, hdlc->state, size))
61 			return -EFAULT;
62 		return 0;
63 
64 	case IF_PROTO_HDLC:
65 		if (!capable(CAP_NET_ADMIN))
66 			return -EPERM;
67 
68 		if (dev->flags & IFF_UP)
69 			return -EBUSY;
70 
71 		if (copy_from_user(&new_settings, raw_s, size))
72 			return -EFAULT;
73 
74 		if (new_settings.encoding == ENCODING_DEFAULT)
75 			new_settings.encoding = ENCODING_NRZ;
76 
77 		if (new_settings.parity == PARITY_DEFAULT)
78 			new_settings.parity = PARITY_CRC16_PR1_CCITT;
79 
80 		result = hdlc->attach(dev, new_settings.encoding,
81 				      new_settings.parity);
82 		if (result)
83 			return result;
84 
85 		result = attach_hdlc_protocol(dev, &proto,
86 					      sizeof(raw_hdlc_proto));
87 		if (result)
88 			return result;
89 		memcpy(hdlc->state, &new_settings, size);
90 		dev->hard_start_xmit = hdlc->xmit;
91 		dev->type = ARPHRD_RAWHDLC;
92 		netif_dormant_off(dev);
93 		return 0;
94 	}
95 
96 	return -EINVAL;
97 }
98 
99 
100 static int __init mod_init(void)
101 {
102 	register_hdlc_protocol(&proto);
103 	return 0;
104 }
105 
106 
107 
108 static void __exit mod_exit(void)
109 {
110 	unregister_hdlc_protocol(&proto);
111 }
112 
113 
114 module_init(mod_init);
115 module_exit(mod_exit);
116 
117 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
118 MODULE_DESCRIPTION("Raw HDLC protocol support for generic HDLC");
119 MODULE_LICENSE("GPL v2");
120