aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/wan/hdlc_cisco.c
blob: 48c03c11cd9a36bc28b115fe3a52c1c0ccbe9362 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
/*
 * Generic HDLC support routines for Linux
 * Cisco HDLC support
 *
 * Copyright (C) 2000 - 2003 Krzysztof Halasa <khc@pm.waw.pl>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/pkt_sched.h>
#include <linux/inetdevice.h>
#include <linux/lapb.h>
#include <linux/rtnetlink.h>
#include <linux/hdlc.h>

#undef DEBUG_HARD_HEADER

#define CISCO_MULTICAST		0x8F	/* Cisco multicast address */
#define CISCO_UNICAST		0x0F	/* Cisco unicast address */
#define CISCO_KEEPALIVE		0x8035	/* Cisco keepalive protocol */
#define CISCO_SYS_INFO		0x2000	/* Cisco interface/system info */
#define CISCO_ADDR_REQ		0	/* Cisco address request */
#define CISCO_ADDR_REPLY	1	/* Cisco address reply */
#define CISCO_KEEPALIVE_REQ	2	/* Cisco keepalive request */


static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,
			     u16 type, void *daddr, void *saddr,
			     unsigned int len)
{
	hdlc_header *data;
#ifdef DEBUG_HARD_HEADER
	printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);
#endif

	skb_push(skb, sizeof(hdlc_header));
	data = (hdlc_header*)skb->data;
	if (type == CISCO_KEEPALIVE)
		data->address = CISCO_MULTICAST;
	else
		data->address = CISCO_UNICAST;
	data->control = 0;
	data->protocol = htons(type);

	return sizeof(hdlc_header);
}



static void cisco_keepalive_send(struct net_device *dev, u32 type,
				 u32 par1, u32 par2)
{
	struct sk_buff *skb;
	cisco_packet *data;

	skb = dev_alloc_skb(sizeof(hdlc_header) + sizeof(cisco_packet));
	if (!skb) {
		printk(KERN_WARNING
		       "%s: Memory squeeze on cisco_keepalive_send()\n",
		       dev->name);
		return;
	}
	skb_reserve(skb, 4);
	cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
	data = (cisco_packet*)skb->data;

	data->type = htonl(type);
	data->par1 = htonl(par1);
	data->par2 = htonl(par2);
	data->rel = 0xFFFF;
	/* we will need do_div here if 1000 % HZ != 0 */
	data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));

	skb_put(skb, sizeof(cisco_packet));
	skb->priority = TC_PRIO_CONTROL;
	skb->dev = dev;
	skb->nh.raw = skb->data;

	dev_queue_xmit(skb);
}



static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev)
{
	hdlc_header *data = (hdlc_header*)skb->data;

	if (skb->len < sizeof(hdlc_header))
		return __constant_htons(ETH_P_HDLC);

	if (data->address != CISCO_MULTICAST &&
	    data->address != CISCO_UNICAST)
		return __constant_htons(ETH_P_HDLC);

	switch(data->protocol) {
	case __constant_htons(ETH_P_IP):
	case __constant_htons(ETH_P_IPX):
	case __constant_htons(ETH_P_IPV6):
		skb_pull(skb, sizeof(hdlc_header));
		return data->protocol;
	default:
		return __constant_htons(ETH_P_HDLC);
	}
}


static int cisco_rx(struct sk_buff *skb)
{
	struct net_device *dev = skb->dev;
	hdlc_device *hdlc = dev_to_hdlc(dev);
	hdlc_header *data = (hdlc_header*)skb->data;
	cisco_packet *cisco_data;
	struct in_device *in_dev;
	u32 addr, mask;

	if (skb->len < sizeof(hdlc_header))
		goto rx_error;

	if (data->address != CISCO_MULTICAST &&
	    data->address != CISCO_UNICAST)
		goto rx_error;

	switch(ntohs(data->protocol)) {
	case CISCO_SYS_INFO:
		/* Packet is not needed, drop it. */
		dev_kfree_skb_any(skb);
		return NET_RX_SUCCESS;

	case CISCO_KEEPALIVE:
		if (skb->len != sizeof(hdlc_header) + CISCO_PACKET_LEN &&
		    skb->len != sizeof(hdlc_header) + CISCO_BIG_PACKET_LEN) {
			printk(KERN_INFO "%s: Invalid length of Cisco "
			       "control packet (%d bytes)\n",
			       dev->name, skb->len);
			goto rx_error;
		}

		cisco_data = (cisco_packet*)(skb->data + sizeof(hdlc_header));

		switch(ntohl (cisco_data->type)) {
		case CISCO_ADDR_REQ: /* Stolen from syncppp.c :-) */
			in_dev = dev->ip_ptr;
			addr = 0;
			mask = ~0; /* is the mask correct? */

			if (in_dev != NULL) {
				struct in_ifaddr **ifap = &in_dev->ifa_list;

				while (*ifap != NULL) {
					if (strcmp(dev->name,
						   (*ifap)->ifa_label) == 0) {
						addr = (*ifap)->ifa_local;
						mask = (*ifap)->ifa_mask;
						break;
					}
					ifap = &(*ifap)->ifa_next;
				}

				cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
						     addr, mask);
			}
			dev_kfree_skb_any(skb);
			return NET_RX_SUCCESS;

		case CISCO_ADDR_REPLY:
			printk(KERN_INFO "%s: Unexpected Cisco IP address "
			       "reply\n", dev->name);
			goto rx_error;

		case CISCO_KEEPALIVE_REQ:
			hdlc->state.cisco.rxseq = ntohl(cisco_data->par1);
			if (hdlc->state.cisco.request_sent &&
			    ntohl(cisco_data->par2)==hdlc->state.cisco.txseq) {
				hdlc->state.cisco.last_poll = jiffies;
				if (!hdlc->state.cisco.up) {
					u32 sec, min, hrs, days;
					sec = ntohl(cisco_data->time) / 1000;
					min = sec / 60; sec -= min * 60;
					hrs = min / 60; min -= hrs * 60;
					days = hrs / 24; hrs -= days * 24;
					printk(KERN_INFO "%s: Link up (peer "
					       "uptime %ud%uh%um%us)\n",
					       dev->name, days, hrs,
					       min, sec);
					netif_carrier_on(dev);
					hdlc->state.cisco.up = 1;
				}
			}

			dev_kfree_skb_any(skb);
			return NET_RX_SUCCESS;
		} /* switch(keepalive type) */
	} /* switch(protocol) */

	printk(KERN_INFO "%s: Unsupported protocol %x\n", dev->name,
	       data->protocol);
	dev_kfree_skb_any(skb);
	return NET_RX_DROP;

 rx_error:
	hdlc->stats.rx_errors++; /* Mark error */
	dev_kfree_skb_any(skb);
	return NET_RX_DROP;
}



static void cisco_timer(unsigned long arg)
{
	struct net_device *dev = (struct net_device *)arg;
	hdlc_device *hdlc = dev_to_hdlc(dev);

	if (hdlc->state.cisco.up &&
	    time_after(jiffies, hdlc->state.cisco.last_poll +
		       hdlc->state.cisco.settings.timeout * HZ)) {
		hdlc->state.cisco.up = 0;
		printk(KERN_INFO "%s: Link down\n", dev->name);
		netif_carrier_off(dev);
	}

	cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ,
			     ++hdlc->state.cisco.txseq,
			     hdlc->state.cisco.rxseq);
	hdlc->state.cisco.request_sent = 1;
	hdlc->state.cisco.timer.expires = jiffies +
		hdlc->state.cisco.settings.interval * HZ;
	hdlc->state.cisco.timer.function = cisco_timer;
	hdlc->state.cisco.timer.data = arg;
	add_timer(&hdlc->state.cisco.timer);
}



static void cisco_start(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	hdlc->state.cisco.up = 0;
	hdlc->state.cisco.request_sent = 0;
	hdlc->state.cisco.txseq = hdlc->state.cisco.rxseq = 0;

	init_timer(&hdlc->state.cisco.timer);
	hdlc->state.cisco.timer.expires = jiffies + HZ; /*First poll after 1s*/
	hdlc->state.cisco.timer.function = cisco_timer;
	hdlc->state.cisco.timer.data = (unsigned long)dev;
	add_timer(&hdlc->state.cisco.timer);
}



static void cisco_stop(struct net_device *dev)
{
	hdlc_device *hdlc = dev_to_hdlc(dev);
	del_timer_sync(&hdlc->state.cisco.timer);
	if (netif_carrier_ok(dev))
		netif_carrier_off(dev);
	hdlc->state.cisco.up = 0;
	hdlc->state.cisco.request_sent = 0;
}



int hdlc_cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
{
	cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
	const size_t size = sizeof(cisco_proto);
	cisco_proto new_settings;
	hdlc_device *hdlc = dev_to_hdlc(dev);
	int result;

	switch (ifr->ifr_settings.type) {
	case IF_GET_PROTO:
		ifr->ifr_settings.type = IF_PROTO_CISCO;
		if (ifr->ifr_settings.size < size) {
			ifr->ifr_settings.size = size; /* data size wanted */
			return -ENOBUFS;
		}
		if (copy_to_user(cisco_s, &hdlc->state.cisco.settings, size))
			return -EFAULT;
		return 0;

	case IF_PROTO_CISCO:
		if(!capable(CAP_NET_ADMIN))
			return -EPERM;

		if(dev->flags & IFF_UP)
			return -EBUSY;

		if (copy_from_user(&new_settings, cisco_s, size))
			return -EFAULT;

		if (new_settings.interval < 1 ||
		    new_settings.timeout < 2)
			return -EINVAL;

		result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);

		if (result)
			return result;

		hdlc_proto_detach(hdlc);
		memcpy(&hdlc->state.cisco.settings, &new_settings, size);
		memset(&hdlc->proto, 0, sizeof(hdlc->proto));

		hdlc->proto.start = cisco_start;
		hdlc->proto.stop = cisco_stop;
		hdlc->proto.netif_rx = cisco_rx;
		hdlc->proto.type_trans = cisco_type_trans;
		hdlc->proto.id = IF_PROTO_CISCO;
		dev->hard_start_xmit = hdlc->xmit;
		dev->hard_header = cisco_hard_header;
		dev->hard_header_cache = NULL;
		dev->type = ARPHRD_CISCO;
		dev->flags = IFF_POINTOPOINT | IFF_NOARP;
		dev->addr_len = 0;
		return 0;
	}

	return -EINVAL;
}