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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#undef DEBUG_HARD_HEADER
25
26#define CISCO_MULTICAST 0x8F
27#define CISCO_UNICAST 0x0F
28#define CISCO_KEEPALIVE 0x8035
29#define CISCO_SYS_INFO 0x2000
30#define CISCO_ADDR_REQ 0
31#define CISCO_ADDR_REPLY 1
32#define CISCO_KEEPALIVE_REQ 2
33
34
35struct hdlc_header {
36 u8 address;
37 u8 control;
38 __be16 protocol;
39}__packed;
40
41
42struct cisco_packet {
43 __be32 type;
44 __be32 par1;
45 __be32 par2;
46 __be16 rel;
47 __be32 time;
48}__packed;
49#define CISCO_PACKET_LEN 18
50#define CISCO_BIG_PACKET_LEN 20
51
52
53struct cisco_state {
54 cisco_proto settings;
55
56 struct timer_list timer;
57 spinlock_t lock;
58 unsigned long last_poll;
59 int up;
60 u32 txseq;
61 u32 rxseq;
62};
63
64
65static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr);
66
67
68static inline struct cisco_state* state(hdlc_device *hdlc)
69{
70 return (struct cisco_state *)hdlc->state;
71}
72
73
74static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,
75 u16 type, const void *daddr, const void *saddr,
76 unsigned int len)
77{
78 struct hdlc_header *data;
79#ifdef DEBUG_HARD_HEADER
80 printk(KERN_DEBUG "%s: cisco_hard_header called\n", dev->name);
81#endif
82
83 skb_push(skb, sizeof(struct hdlc_header));
84 data = (struct hdlc_header*)skb->data;
85 if (type == CISCO_KEEPALIVE)
86 data->address = CISCO_MULTICAST;
87 else
88 data->address = CISCO_UNICAST;
89 data->control = 0;
90 data->protocol = htons(type);
91
92 return sizeof(struct hdlc_header);
93}
94
95
96
97static void cisco_keepalive_send(struct net_device *dev, u32 type,
98 __be32 par1, __be32 par2)
99{
100 struct sk_buff *skb;
101 struct cisco_packet *data;
102
103 skb = dev_alloc_skb(sizeof(struct hdlc_header) +
104 sizeof(struct cisco_packet));
105 if (!skb) {
106 netdev_warn(dev, "Memory squeeze on cisco_keepalive_send()\n");
107 return;
108 }
109 skb_reserve(skb, 4);
110 cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
111 data = (struct cisco_packet*)(skb->data + 4);
112
113 data->type = htonl(type);
114 data->par1 = par1;
115 data->par2 = par2;
116 data->rel = cpu_to_be16(0xFFFF);
117
118 data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));
119
120 skb_put(skb, sizeof(struct cisco_packet));
121 skb->priority = TC_PRIO_CONTROL;
122 skb->dev = dev;
123 skb_reset_network_header(skb);
124
125 dev_queue_xmit(skb);
126}
127
128
129
130static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev)
131{
132 struct hdlc_header *data = (struct hdlc_header*)skb->data;
133
134 if (skb->len < sizeof(struct hdlc_header))
135 return cpu_to_be16(ETH_P_HDLC);
136
137 if (data->address != CISCO_MULTICAST &&
138 data->address != CISCO_UNICAST)
139 return cpu_to_be16(ETH_P_HDLC);
140
141 switch (data->protocol) {
142 case cpu_to_be16(ETH_P_IP):
143 case cpu_to_be16(ETH_P_IPX):
144 case cpu_to_be16(ETH_P_IPV6):
145 skb_pull(skb, sizeof(struct hdlc_header));
146 return data->protocol;
147 default:
148 return cpu_to_be16(ETH_P_HDLC);
149 }
150}
151
152
153static int cisco_rx(struct sk_buff *skb)
154{
155 struct net_device *dev = skb->dev;
156 hdlc_device *hdlc = dev_to_hdlc(dev);
157 struct cisco_state *st = state(hdlc);
158 struct hdlc_header *data = (struct hdlc_header*)skb->data;
159 struct cisco_packet *cisco_data;
160 struct in_device *in_dev;
161 __be32 addr, mask;
162 u32 ack;
163
164 if (skb->len < sizeof(struct hdlc_header))
165 goto rx_error;
166
167 if (data->address != CISCO_MULTICAST &&
168 data->address != CISCO_UNICAST)
169 goto rx_error;
170
171 switch (ntohs(data->protocol)) {
172 case CISCO_SYS_INFO:
173
174 dev_kfree_skb_any(skb);
175 return NET_RX_SUCCESS;
176
177 case CISCO_KEEPALIVE:
178 if ((skb->len != sizeof(struct hdlc_header) +
179 CISCO_PACKET_LEN) &&
180 (skb->len != sizeof(struct hdlc_header) +
181 CISCO_BIG_PACKET_LEN)) {
182 netdev_info(dev, "Invalid length of Cisco control packet (%d bytes)\n",
183 skb->len);
184 goto rx_error;
185 }
186
187 cisco_data = (struct cisco_packet*)(skb->data + sizeof
188 (struct hdlc_header));
189
190 switch (ntohl (cisco_data->type)) {
191 case CISCO_ADDR_REQ:
192 rcu_read_lock();
193 in_dev = __in_dev_get_rcu(dev);
194 addr = 0;
195 mask = ~cpu_to_be32(0);
196
197 if (in_dev != NULL) {
198 struct in_ifaddr **ifap = &in_dev->ifa_list;
199
200 while (*ifap != NULL) {
201 if (strcmp(dev->name,
202 (*ifap)->ifa_label) == 0) {
203 addr = (*ifap)->ifa_local;
204 mask = (*ifap)->ifa_mask;
205 break;
206 }
207 ifap = &(*ifap)->ifa_next;
208 }
209
210 cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
211 addr, mask);
212 }
213 rcu_read_unlock();
214 dev_kfree_skb_any(skb);
215 return NET_RX_SUCCESS;
216
217 case CISCO_ADDR_REPLY:
218 netdev_info(dev, "Unexpected Cisco IP address reply\n");
219 goto rx_error;
220
221 case CISCO_KEEPALIVE_REQ:
222 spin_lock(&st->lock);
223 st->rxseq = ntohl(cisco_data->par1);
224 ack = ntohl(cisco_data->par2);
225 if (ack && (ack == st->txseq ||
226
227 ack == st->txseq - 1)) {
228 st->last_poll = jiffies;
229 if (!st->up) {
230 u32 sec, min, hrs, days;
231 sec = ntohl(cisco_data->time) / 1000;
232 min = sec / 60; sec -= min * 60;
233 hrs = min / 60; min -= hrs * 60;
234 days = hrs / 24; hrs -= days * 24;
235 netdev_info(dev, "Link up (peer uptime %ud%uh%um%us)\n",
236 days, hrs, min, sec);
237 netif_dormant_off(dev);
238 st->up = 1;
239 }
240 }
241 spin_unlock(&st->lock);
242
243 dev_kfree_skb_any(skb);
244 return NET_RX_SUCCESS;
245 }
246 }
247
248 netdev_info(dev, "Unsupported protocol %x\n", ntohs(data->protocol));
249 dev_kfree_skb_any(skb);
250 return NET_RX_DROP;
251
252rx_error:
253 dev->stats.rx_errors++;
254 dev_kfree_skb_any(skb);
255 return NET_RX_DROP;
256}
257
258
259
260static void cisco_timer(unsigned long arg)
261{
262 struct net_device *dev = (struct net_device *)arg;
263 hdlc_device *hdlc = dev_to_hdlc(dev);
264 struct cisco_state *st = state(hdlc);
265
266 spin_lock(&st->lock);
267 if (st->up &&
268 time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) {
269 st->up = 0;
270 netdev_info(dev, "Link down\n");
271 netif_dormant_on(dev);
272 }
273
274 cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq),
275 htonl(st->rxseq));
276 spin_unlock(&st->lock);
277
278 st->timer.expires = jiffies + st->settings.interval * HZ;
279 st->timer.function = cisco_timer;
280 st->timer.data = arg;
281 add_timer(&st->timer);
282}
283
284
285
286static void cisco_start(struct net_device *dev)
287{
288 hdlc_device *hdlc = dev_to_hdlc(dev);
289 struct cisco_state *st = state(hdlc);
290 unsigned long flags;
291
292 spin_lock_irqsave(&st->lock, flags);
293 st->up = st->txseq = st->rxseq = 0;
294 spin_unlock_irqrestore(&st->lock, flags);
295
296 init_timer(&st->timer);
297 st->timer.expires = jiffies + HZ;
298 st->timer.function = cisco_timer;
299 st->timer.data = (unsigned long)dev;
300 add_timer(&st->timer);
301}
302
303
304
305static void cisco_stop(struct net_device *dev)
306{
307 hdlc_device *hdlc = dev_to_hdlc(dev);
308 struct cisco_state *st = state(hdlc);
309 unsigned long flags;
310
311 del_timer_sync(&st->timer);
312
313 spin_lock_irqsave(&st->lock, flags);
314 netif_dormant_on(dev);
315 st->up = st->txseq = 0;
316 spin_unlock_irqrestore(&st->lock, flags);
317}
318
319
320static struct hdlc_proto proto = {
321 .start = cisco_start,
322 .stop = cisco_stop,
323 .type_trans = cisco_type_trans,
324 .ioctl = cisco_ioctl,
325 .netif_rx = cisco_rx,
326 .module = THIS_MODULE,
327};
328
329static const struct header_ops cisco_header_ops = {
330 .create = cisco_hard_header,
331};
332
333static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
334{
335 cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
336 const size_t size = sizeof(cisco_proto);
337 cisco_proto new_settings;
338 hdlc_device *hdlc = dev_to_hdlc(dev);
339 int result;
340
341 switch (ifr->ifr_settings.type) {
342 case IF_GET_PROTO:
343 if (dev_to_hdlc(dev)->proto != &proto)
344 return -EINVAL;
345 ifr->ifr_settings.type = IF_PROTO_CISCO;
346 if (ifr->ifr_settings.size < size) {
347 ifr->ifr_settings.size = size;
348 return -ENOBUFS;
349 }
350 if (copy_to_user(cisco_s, &state(hdlc)->settings, size))
351 return -EFAULT;
352 return 0;
353
354 case IF_PROTO_CISCO:
355 if (!capable(CAP_NET_ADMIN))
356 return -EPERM;
357
358 if (dev->flags & IFF_UP)
359 return -EBUSY;
360
361 if (copy_from_user(&new_settings, cisco_s, size))
362 return -EFAULT;
363
364 if (new_settings.interval < 1 ||
365 new_settings.timeout < 2)
366 return -EINVAL;
367
368 result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
369 if (result)
370 return result;
371
372 result = attach_hdlc_protocol(dev, &proto,
373 sizeof(struct cisco_state));
374 if (result)
375 return result;
376
377 memcpy(&state(hdlc)->settings, &new_settings, size);
378 spin_lock_init(&state(hdlc)->lock);
379 dev->header_ops = &cisco_header_ops;
380 dev->type = ARPHRD_CISCO;
381 netif_dormant_on(dev);
382 return 0;
383 }
384
385 return -EINVAL;
386}
387
388
389static int __init mod_init(void)
390{
391 register_hdlc_protocol(&proto);
392 return 0;
393}
394
395
396
397static void __exit mod_exit(void)
398{
399 unregister_hdlc_protocol(&proto);
400}
401
402
403module_init(mod_init);
404module_exit(mod_exit);
405
406MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
407MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC");
408MODULE_LICENSE("GPL v2");
409
