1
2
3
4
5
6
7
8
9#include <linux/errno.h>
10#include <linux/hdlc.h>
11#include <linux/if_arp.h>
12#include <linux/inetdevice.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/pkt_sched.h>
17#include <linux/poll.h>
18#include <linux/rtnetlink.h>
19#include <linux/skbuff.h>
20
21#undef DEBUG_HARD_HEADER
22
23#define CISCO_MULTICAST 0x8F
24#define CISCO_UNICAST 0x0F
25#define CISCO_KEEPALIVE 0x8035
26#define CISCO_SYS_INFO 0x2000
27#define CISCO_ADDR_REQ 0
28#define CISCO_ADDR_REPLY 1
29#define CISCO_KEEPALIVE_REQ 2
30
31
32struct hdlc_header {
33 u8 address;
34 u8 control;
35 __be16 protocol;
36}__packed;
37
38
39struct cisco_packet {
40 __be32 type;
41 __be32 par1;
42 __be32 par2;
43 __be16 rel;
44 __be32 time;
45}__packed;
46#define CISCO_PACKET_LEN 18
47#define CISCO_BIG_PACKET_LEN 20
48
49
50struct cisco_state {
51 cisco_proto settings;
52
53 struct timer_list timer;
54 struct net_device *dev;
55 spinlock_t lock;
56 unsigned long last_poll;
57 int up;
58 u32 txseq;
59 u32 rxseq;
60};
61
62
63static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr);
64
65
66static inline struct cisco_state* state(hdlc_device *hdlc)
67{
68 return (struct cisco_state *)hdlc->state;
69}
70
71
72static int cisco_hard_header(struct sk_buff *skb, struct net_device *dev,
73 u16 type, const void *daddr, const void *saddr,
74 unsigned int len)
75{
76 struct hdlc_header *data;
77#ifdef DEBUG_HARD_HEADER
78 netdev_dbg(dev, "%s called\n", __func__);
79#endif
80
81 skb_push(skb, sizeof(struct hdlc_header));
82 data = (struct hdlc_header*)skb->data;
83 if (type == CISCO_KEEPALIVE)
84 data->address = CISCO_MULTICAST;
85 else
86 data->address = CISCO_UNICAST;
87 data->control = 0;
88 data->protocol = htons(type);
89
90 return sizeof(struct hdlc_header);
91}
92
93
94
95static void cisco_keepalive_send(struct net_device *dev, u32 type,
96 __be32 par1, __be32 par2)
97{
98 struct sk_buff *skb;
99 struct cisco_packet *data;
100
101 skb = dev_alloc_skb(sizeof(struct hdlc_header) +
102 sizeof(struct cisco_packet));
103 if (!skb) {
104 netdev_warn(dev, "Memory squeeze on %s()\n", __func__);
105 return;
106 }
107 skb_reserve(skb, 4);
108 cisco_hard_header(skb, dev, CISCO_KEEPALIVE, NULL, NULL, 0);
109 data = (struct cisco_packet*)(skb->data + 4);
110
111 data->type = htonl(type);
112 data->par1 = par1;
113 data->par2 = par2;
114 data->rel = cpu_to_be16(0xFFFF);
115
116 data->time = htonl((jiffies - INITIAL_JIFFIES) * (1000 / HZ));
117
118 skb_put(skb, sizeof(struct cisco_packet));
119 skb->priority = TC_PRIO_CONTROL;
120 skb->dev = dev;
121 skb->protocol = htons(ETH_P_HDLC);
122 skb_reset_network_header(skb);
123
124 dev_queue_xmit(skb);
125}
126
127
128
129static __be16 cisco_type_trans(struct sk_buff *skb, struct net_device *dev)
130{
131 struct hdlc_header *data = (struct hdlc_header*)skb->data;
132
133 if (skb->len < sizeof(struct hdlc_header))
134 return cpu_to_be16(ETH_P_HDLC);
135
136 if (data->address != CISCO_MULTICAST &&
137 data->address != CISCO_UNICAST)
138 return cpu_to_be16(ETH_P_HDLC);
139
140 switch (data->protocol) {
141 case cpu_to_be16(ETH_P_IP):
142 case cpu_to_be16(ETH_P_IPX):
143 case cpu_to_be16(ETH_P_IPV6):
144 skb_pull(skb, sizeof(struct hdlc_header));
145 return data->protocol;
146 default:
147 return cpu_to_be16(ETH_P_HDLC);
148 }
149}
150
151
152static int cisco_rx(struct sk_buff *skb)
153{
154 struct net_device *dev = skb->dev;
155 hdlc_device *hdlc = dev_to_hdlc(dev);
156 struct cisco_state *st = state(hdlc);
157 struct hdlc_header *data = (struct hdlc_header*)skb->data;
158 struct cisco_packet *cisco_data;
159 struct in_device *in_dev;
160 __be32 addr, mask;
161 u32 ack;
162
163 if (skb->len < sizeof(struct hdlc_header))
164 goto rx_error;
165
166 if (data->address != CISCO_MULTICAST &&
167 data->address != CISCO_UNICAST)
168 goto rx_error;
169
170 switch (ntohs(data->protocol)) {
171 case CISCO_SYS_INFO:
172
173 dev_kfree_skb_any(skb);
174 return NET_RX_SUCCESS;
175
176 case CISCO_KEEPALIVE:
177 if ((skb->len != sizeof(struct hdlc_header) +
178 CISCO_PACKET_LEN) &&
179 (skb->len != sizeof(struct hdlc_header) +
180 CISCO_BIG_PACKET_LEN)) {
181 netdev_info(dev, "Invalid length of Cisco control packet (%d bytes)\n",
182 skb->len);
183 goto rx_error;
184 }
185
186 cisco_data = (struct cisco_packet*)(skb->data + sizeof
187 (struct hdlc_header));
188
189 switch (ntohl (cisco_data->type)) {
190 case CISCO_ADDR_REQ:
191 rcu_read_lock();
192 in_dev = __in_dev_get_rcu(dev);
193 addr = 0;
194 mask = ~cpu_to_be32(0);
195
196 if (in_dev != NULL) {
197 const struct in_ifaddr *ifa;
198
199 in_dev_for_each_ifa_rcu(ifa, in_dev) {
200 if (strcmp(dev->name,
201 ifa->ifa_label) == 0) {
202 addr = ifa->ifa_local;
203 mask = ifa->ifa_mask;
204 break;
205 }
206 }
207
208 cisco_keepalive_send(dev, CISCO_ADDR_REPLY,
209 addr, mask);
210 }
211 rcu_read_unlock();
212 dev_kfree_skb_any(skb);
213 return NET_RX_SUCCESS;
214
215 case CISCO_ADDR_REPLY:
216 netdev_info(dev, "Unexpected Cisco IP address reply\n");
217 goto rx_error;
218
219 case CISCO_KEEPALIVE_REQ:
220 spin_lock(&st->lock);
221 st->rxseq = ntohl(cisco_data->par1);
222 ack = ntohl(cisco_data->par2);
223 if (ack && (ack == st->txseq ||
224
225 ack == st->txseq - 1)) {
226 st->last_poll = jiffies;
227 if (!st->up) {
228 u32 sec, min, hrs, days;
229 sec = ntohl(cisco_data->time) / 1000;
230 min = sec / 60; sec -= min * 60;
231 hrs = min / 60; min -= hrs * 60;
232 days = hrs / 24; hrs -= days * 24;
233 netdev_info(dev, "Link up (peer uptime %ud%uh%um%us)\n",
234 days, hrs, min, sec);
235 netif_dormant_off(dev);
236 st->up = 1;
237 }
238 }
239 spin_unlock(&st->lock);
240
241 dev_kfree_skb_any(skb);
242 return NET_RX_SUCCESS;
243 }
244 }
245
246 netdev_info(dev, "Unsupported protocol %x\n", ntohs(data->protocol));
247 dev_kfree_skb_any(skb);
248 return NET_RX_DROP;
249
250rx_error:
251 dev->stats.rx_errors++;
252 dev_kfree_skb_any(skb);
253 return NET_RX_DROP;
254}
255
256
257
258static void cisco_timer(struct timer_list *t)
259{
260 struct cisco_state *st = from_timer(st, t, timer);
261 struct net_device *dev = st->dev;
262
263 spin_lock(&st->lock);
264 if (st->up &&
265 time_after(jiffies, st->last_poll + st->settings.timeout * HZ)) {
266 st->up = 0;
267 netdev_info(dev, "Link down\n");
268 netif_dormant_on(dev);
269 }
270
271 cisco_keepalive_send(dev, CISCO_KEEPALIVE_REQ, htonl(++st->txseq),
272 htonl(st->rxseq));
273 spin_unlock(&st->lock);
274
275 st->timer.expires = jiffies + st->settings.interval * HZ;
276 add_timer(&st->timer);
277}
278
279
280
281static void cisco_start(struct net_device *dev)
282{
283 hdlc_device *hdlc = dev_to_hdlc(dev);
284 struct cisco_state *st = state(hdlc);
285 unsigned long flags;
286
287 spin_lock_irqsave(&st->lock, flags);
288 st->up = st->txseq = st->rxseq = 0;
289 spin_unlock_irqrestore(&st->lock, flags);
290
291 st->dev = dev;
292 timer_setup(&st->timer, cisco_timer, 0);
293 st->timer.expires = jiffies + HZ;
294 add_timer(&st->timer);
295}
296
297
298
299static void cisco_stop(struct net_device *dev)
300{
301 hdlc_device *hdlc = dev_to_hdlc(dev);
302 struct cisco_state *st = state(hdlc);
303 unsigned long flags;
304
305 del_timer_sync(&st->timer);
306
307 spin_lock_irqsave(&st->lock, flags);
308 netif_dormant_on(dev);
309 st->up = st->txseq = 0;
310 spin_unlock_irqrestore(&st->lock, flags);
311}
312
313
314static struct hdlc_proto proto = {
315 .start = cisco_start,
316 .stop = cisco_stop,
317 .type_trans = cisco_type_trans,
318 .ioctl = cisco_ioctl,
319 .netif_rx = cisco_rx,
320 .module = THIS_MODULE,
321};
322
323static const struct header_ops cisco_header_ops = {
324 .create = cisco_hard_header,
325};
326
327static int cisco_ioctl(struct net_device *dev, struct ifreq *ifr)
328{
329 cisco_proto __user *cisco_s = ifr->ifr_settings.ifs_ifsu.cisco;
330 const size_t size = sizeof(cisco_proto);
331 cisco_proto new_settings;
332 hdlc_device *hdlc = dev_to_hdlc(dev);
333 int result;
334
335 switch (ifr->ifr_settings.type) {
336 case IF_GET_PROTO:
337 if (dev_to_hdlc(dev)->proto != &proto)
338 return -EINVAL;
339 ifr->ifr_settings.type = IF_PROTO_CISCO;
340 if (ifr->ifr_settings.size < size) {
341 ifr->ifr_settings.size = size;
342 return -ENOBUFS;
343 }
344 if (copy_to_user(cisco_s, &state(hdlc)->settings, size))
345 return -EFAULT;
346 return 0;
347
348 case IF_PROTO_CISCO:
349 if (!capable(CAP_NET_ADMIN))
350 return -EPERM;
351
352 if (dev->flags & IFF_UP)
353 return -EBUSY;
354
355 if (copy_from_user(&new_settings, cisco_s, size))
356 return -EFAULT;
357
358 if (new_settings.interval < 1 ||
359 new_settings.timeout < 2)
360 return -EINVAL;
361
362 result = hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
363 if (result)
364 return result;
365
366 result = attach_hdlc_protocol(dev, &proto,
367 sizeof(struct cisco_state));
368 if (result)
369 return result;
370
371 memcpy(&state(hdlc)->settings, &new_settings, size);
372 spin_lock_init(&state(hdlc)->lock);
373 dev->header_ops = &cisco_header_ops;
374 dev->hard_header_len = sizeof(struct hdlc_header);
375 dev->type = ARPHRD_CISCO;
376 call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
377 netif_dormant_on(dev);
378 return 0;
379 }
380
381 return -EINVAL;
382}
383
384
385static int __init mod_init(void)
386{
387 register_hdlc_protocol(&proto);
388 return 0;
389}
390
391
392
393static void __exit mod_exit(void)
394{
395 unregister_hdlc_protocol(&proto);
396}
397
398
399module_init(mod_init);
400module_exit(mod_exit);
401
402MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
403MODULE_DESCRIPTION("Cisco HDLC protocol support for generic HDLC");
404MODULE_LICENSE("GPL v2");
405
