xref: /openbmc/linux/drivers/net/wan/hdlc_raw.c (revision 384740dc)
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 #include <linux/slab.h>
24 
25 
26 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr);
27 
28 static __be16 raw_type_trans(struct sk_buff *skb, struct net_device *dev)
29 {
30 	return __constant_htons(ETH_P_IP);
31 }
32 
33 
34 
35 static struct hdlc_proto proto = {
36 	.type_trans	= raw_type_trans,
37 	.ioctl		= raw_ioctl,
38 	.module		= THIS_MODULE,
39 };
40 
41 
42 static int raw_ioctl(struct net_device *dev, struct ifreq *ifr)
43 {
44 	raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
45 	const size_t size = sizeof(raw_hdlc_proto);
46 	raw_hdlc_proto new_settings;
47 	hdlc_device *hdlc = dev_to_hdlc(dev);
48 	int result;
49 
50 	switch (ifr->ifr_settings.type) {
51 	case IF_GET_PROTO:
52 		if (dev_to_hdlc(dev)->proto != &proto)
53 			return -EINVAL;
54 		ifr->ifr_settings.type = IF_PROTO_HDLC;
55 		if (ifr->ifr_settings.size < size) {
56 			ifr->ifr_settings.size = size; /* data size wanted */
57 			return -ENOBUFS;
58 		}
59 		if (copy_to_user(raw_s, hdlc->state, size))
60 			return -EFAULT;
61 		return 0;
62 
63 	case IF_PROTO_HDLC:
64 		if (!capable(CAP_NET_ADMIN))
65 			return -EPERM;
66 
67 		if (dev->flags & IFF_UP)
68 			return -EBUSY;
69 
70 		if (copy_from_user(&new_settings, raw_s, size))
71 			return -EFAULT;
72 
73 		if (new_settings.encoding == ENCODING_DEFAULT)
74 			new_settings.encoding = ENCODING_NRZ;
75 
76 		if (new_settings.parity == PARITY_DEFAULT)
77 			new_settings.parity = PARITY_CRC16_PR1_CCITT;
78 
79 		result = hdlc->attach(dev, new_settings.encoding,
80 				      new_settings.parity);
81 		if (result)
82 			return result;
83 
84 		result = attach_hdlc_protocol(dev, &proto,
85 					      sizeof(raw_hdlc_proto));
86 		if (result)
87 			return result;
88 		memcpy(hdlc->state, &new_settings, size);
89 		dev->hard_start_xmit = hdlc->xmit;
90 		dev->type = ARPHRD_RAWHDLC;
91 		netif_dormant_off(dev);
92 		return 0;
93 	}
94 
95 	return -EINVAL;
96 }
97 
98 
99 static int __init mod_init(void)
100 {
101 	register_hdlc_protocol(&proto);
102 	return 0;
103 }
104 
105 
106 
107 static void __exit mod_exit(void)
108 {
109 	unregister_hdlc_protocol(&proto);
110 }
111 
112 
113 module_init(mod_init);
114 module_exit(mod_exit);
115 
116 MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
117 MODULE_DESCRIPTION("Raw HDLC protocol support for generic HDLC");
118 MODULE_LICENSE("GPL v2");
119