xref: /openbmc/linux/drivers/net/wan/hdlc_raw.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 /*
2  * Generic HDLC support routines for Linux
3  * HDLC support
4  *
5  * Copyright (C) 1999 - 2003 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 unsigned short raw_type_trans(struct sk_buff *skb,
28 				     struct net_device *dev)
29 {
30 	return __constant_htons(ETH_P_IP);
31 }
32 
33 
34 
35 int hdlc_raw_ioctl(struct net_device *dev, struct ifreq *ifr)
36 {
37 	raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
38 	const size_t size = sizeof(raw_hdlc_proto);
39 	raw_hdlc_proto new_settings;
40 	hdlc_device *hdlc = dev_to_hdlc(dev);
41 	int result;
42 
43 	switch (ifr->ifr_settings.type) {
44 	case IF_GET_PROTO:
45 		ifr->ifr_settings.type = IF_PROTO_HDLC;
46 		if (ifr->ifr_settings.size < size) {
47 			ifr->ifr_settings.size = size; /* data size wanted */
48 			return -ENOBUFS;
49 		}
50 		if (copy_to_user(raw_s, &hdlc->state.raw_hdlc.settings, size))
51 			return -EFAULT;
52 		return 0;
53 
54 	case IF_PROTO_HDLC:
55 		if (!capable(CAP_NET_ADMIN))
56 			return -EPERM;
57 
58 		if (dev->flags & IFF_UP)
59 			return -EBUSY;
60 
61 		if (copy_from_user(&new_settings, raw_s, size))
62 			return -EFAULT;
63 
64 		if (new_settings.encoding == ENCODING_DEFAULT)
65 			new_settings.encoding = ENCODING_NRZ;
66 
67 		if (new_settings.parity == PARITY_DEFAULT)
68 			new_settings.parity = PARITY_CRC16_PR1_CCITT;
69 
70 		result = hdlc->attach(dev, new_settings.encoding,
71 				      new_settings.parity);
72 		if (result)
73 			return result;
74 
75 		hdlc_proto_detach(hdlc);
76 		memcpy(&hdlc->state.raw_hdlc.settings, &new_settings, size);
77 		memset(&hdlc->proto, 0, sizeof(hdlc->proto));
78 
79 		hdlc->proto.type_trans = raw_type_trans;
80 		hdlc->proto.id = IF_PROTO_HDLC;
81 		dev->hard_start_xmit = hdlc->xmit;
82 		dev->hard_header = NULL;
83 		dev->type = ARPHRD_RAWHDLC;
84 		dev->flags = IFF_POINTOPOINT | IFF_NOARP;
85 		dev->addr_len = 0;
86 		return 0;
87 	}
88 
89 	return -EINVAL;
90 }
91