1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19
20#include <linux/module.h>
21#include <linux/errno.h>
22#include <linux/types.h>
23#include <linux/socket.h>
24#include <linux/in.h>
25#include <linux/kernel.h>
26#include <linux/jiffies.h>
27#include <linux/timer.h>
28#include <linux/string.h>
29#include <linux/sockios.h>
30#include <linux/net.h>
31#include <linux/inet.h>
32#include <linux/if_arp.h>
33#include <linux/skbuff.h>
34#include <linux/slab.h>
35#include <net/sock.h>
36#include <asm/uaccess.h>
37#include <linux/fcntl.h>
38#include <linux/mm.h>
39#include <linux/interrupt.h>
40#include <linux/stat.h>
41#include <linux/init.h>
42#include <net/lapb.h>
43
44static LIST_HEAD(lapb_list);
45static DEFINE_RWLOCK(lapb_list_lock);
46
47
48
49
50static void lapb_free_cb(struct lapb_cb *lapb)
51{
52 kfree(lapb);
53}
54
55static __inline__ void lapb_hold(struct lapb_cb *lapb)
56{
57 atomic_inc(&lapb->refcnt);
58}
59
60static __inline__ void lapb_put(struct lapb_cb *lapb)
61{
62 if (atomic_dec_and_test(&lapb->refcnt))
63 lapb_free_cb(lapb);
64}
65
66
67
68
69static void __lapb_remove_cb(struct lapb_cb *lapb)
70{
71 if (lapb->node.next) {
72 list_del(&lapb->node);
73 lapb_put(lapb);
74 }
75}
76
77
78
79
80static void __lapb_insert_cb(struct lapb_cb *lapb)
81{
82 list_add(&lapb->node, &lapb_list);
83 lapb_hold(lapb);
84}
85
86static struct lapb_cb *__lapb_devtostruct(struct net_device *dev)
87{
88 struct list_head *entry;
89 struct lapb_cb *lapb, *use = NULL;
90
91 list_for_each(entry, &lapb_list) {
92 lapb = list_entry(entry, struct lapb_cb, node);
93 if (lapb->dev == dev) {
94 use = lapb;
95 break;
96 }
97 }
98
99 if (use)
100 lapb_hold(use);
101
102 return use;
103}
104
105static struct lapb_cb *lapb_devtostruct(struct net_device *dev)
106{
107 struct lapb_cb *rc;
108
109 read_lock_bh(&lapb_list_lock);
110 rc = __lapb_devtostruct(dev);
111 read_unlock_bh(&lapb_list_lock);
112
113 return rc;
114}
115
116
117
118static struct lapb_cb *lapb_create_cb(void)
119{
120 struct lapb_cb *lapb = kzalloc(sizeof(*lapb), GFP_ATOMIC);
121
122
123 if (!lapb)
124 goto out;
125
126 skb_queue_head_init(&lapb->write_queue);
127 skb_queue_head_init(&lapb->ack_queue);
128
129 init_timer(&lapb->t1timer);
130 init_timer(&lapb->t2timer);
131
132 lapb->t1 = LAPB_DEFAULT_T1;
133 lapb->t2 = LAPB_DEFAULT_T2;
134 lapb->n2 = LAPB_DEFAULT_N2;
135 lapb->mode = LAPB_DEFAULT_MODE;
136 lapb->window = LAPB_DEFAULT_WINDOW;
137 lapb->state = LAPB_STATE_0;
138 atomic_set(&lapb->refcnt, 1);
139out:
140 return lapb;
141}
142
143int lapb_register(struct net_device *dev,
144 const struct lapb_register_struct *callbacks)
145{
146 struct lapb_cb *lapb;
147 int rc = LAPB_BADTOKEN;
148
149 write_lock_bh(&lapb_list_lock);
150
151 lapb = __lapb_devtostruct(dev);
152 if (lapb) {
153 lapb_put(lapb);
154 goto out;
155 }
156
157 lapb = lapb_create_cb();
158 rc = LAPB_NOMEM;
159 if (!lapb)
160 goto out;
161
162 lapb->dev = dev;
163 lapb->callbacks = callbacks;
164
165 __lapb_insert_cb(lapb);
166
167 lapb_start_t1timer(lapb);
168
169 rc = LAPB_OK;
170out:
171 write_unlock_bh(&lapb_list_lock);
172 return rc;
173}
174
175int lapb_unregister(struct net_device *dev)
176{
177 struct lapb_cb *lapb;
178 int rc = LAPB_BADTOKEN;
179
180 write_lock_bh(&lapb_list_lock);
181 lapb = __lapb_devtostruct(dev);
182 if (!lapb)
183 goto out;
184
185 lapb_stop_t1timer(lapb);
186 lapb_stop_t2timer(lapb);
187
188 lapb_clear_queues(lapb);
189
190 __lapb_remove_cb(lapb);
191
192 lapb_put(lapb);
193 rc = LAPB_OK;
194out:
195 write_unlock_bh(&lapb_list_lock);
196 return rc;
197}
198
199int lapb_getparms(struct net_device *dev, struct lapb_parms_struct *parms)
200{
201 int rc = LAPB_BADTOKEN;
202 struct lapb_cb *lapb = lapb_devtostruct(dev);
203
204 if (!lapb)
205 goto out;
206
207 parms->t1 = lapb->t1 / HZ;
208 parms->t2 = lapb->t2 / HZ;
209 parms->n2 = lapb->n2;
210 parms->n2count = lapb->n2count;
211 parms->state = lapb->state;
212 parms->window = lapb->window;
213 parms->mode = lapb->mode;
214
215 if (!timer_pending(&lapb->t1timer))
216 parms->t1timer = 0;
217 else
218 parms->t1timer = (lapb->t1timer.expires - jiffies) / HZ;
219
220 if (!timer_pending(&lapb->t2timer))
221 parms->t2timer = 0;
222 else
223 parms->t2timer = (lapb->t2timer.expires - jiffies) / HZ;
224
225 lapb_put(lapb);
226 rc = LAPB_OK;
227out:
228 return rc;
229}
230
231int lapb_setparms(struct net_device *dev, struct lapb_parms_struct *parms)
232{
233 int rc = LAPB_BADTOKEN;
234 struct lapb_cb *lapb = lapb_devtostruct(dev);
235
236 if (!lapb)
237 goto out;
238
239 rc = LAPB_INVALUE;
240 if (parms->t1 < 1 || parms->t2 < 1 || parms->n2 < 1)
241 goto out_put;
242
243 if (lapb->state == LAPB_STATE_0) {
244 if (parms->mode & LAPB_EXTENDED) {
245 if (parms->window < 1 || parms->window > 127)
246 goto out_put;
247 } else {
248 if (parms->window < 1 || parms->window > 7)
249 goto out_put;
250 }
251 lapb->mode = parms->mode;
252 lapb->window = parms->window;
253 }
254
255 lapb->t1 = parms->t1 * HZ;
256 lapb->t2 = parms->t2 * HZ;
257 lapb->n2 = parms->n2;
258
259 rc = LAPB_OK;
260out_put:
261 lapb_put(lapb);
262out:
263 return rc;
264}
265
266int lapb_connect_request(struct net_device *dev)
267{
268 struct lapb_cb *lapb = lapb_devtostruct(dev);
269 int rc = LAPB_BADTOKEN;
270
271 if (!lapb)
272 goto out;
273
274 rc = LAPB_OK;
275 if (lapb->state == LAPB_STATE_1)
276 goto out_put;
277
278 rc = LAPB_CONNECTED;
279 if (lapb->state == LAPB_STATE_3 || lapb->state == LAPB_STATE_4)
280 goto out_put;
281
282 lapb_establish_data_link(lapb);
283
284 lapb_dbg(0, "(%p) S0 -> S1\n", lapb->dev);
285 lapb->state = LAPB_STATE_1;
286
287 rc = LAPB_OK;
288out_put:
289 lapb_put(lapb);
290out:
291 return rc;
292}
293
294int lapb_disconnect_request(struct net_device *dev)
295{
296 struct lapb_cb *lapb = lapb_devtostruct(dev);
297 int rc = LAPB_BADTOKEN;
298
299 if (!lapb)
300 goto out;
301
302 switch (lapb->state) {
303 case LAPB_STATE_0:
304 rc = LAPB_NOTCONNECTED;
305 goto out_put;
306
307 case LAPB_STATE_1:
308 lapb_dbg(1, "(%p) S1 TX DISC(1)\n", lapb->dev);
309 lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
310 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
311 lapb->state = LAPB_STATE_0;
312 lapb_start_t1timer(lapb);
313 rc = LAPB_NOTCONNECTED;
314 goto out_put;
315
316 case LAPB_STATE_2:
317 rc = LAPB_OK;
318 goto out_put;
319 }
320
321 lapb_clear_queues(lapb);
322 lapb->n2count = 0;
323 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
324 lapb_start_t1timer(lapb);
325 lapb_stop_t2timer(lapb);
326 lapb->state = LAPB_STATE_2;
327
328 lapb_dbg(1, "(%p) S3 DISC(1)\n", lapb->dev);
329 lapb_dbg(0, "(%p) S3 -> S2\n", lapb->dev);
330
331 rc = LAPB_OK;
332out_put:
333 lapb_put(lapb);
334out:
335 return rc;
336}
337
338int lapb_data_request(struct net_device *dev, struct sk_buff *skb)
339{
340 struct lapb_cb *lapb = lapb_devtostruct(dev);
341 int rc = LAPB_BADTOKEN;
342
343 if (!lapb)
344 goto out;
345
346 rc = LAPB_NOTCONNECTED;
347 if (lapb->state != LAPB_STATE_3 && lapb->state != LAPB_STATE_4)
348 goto out_put;
349
350 skb_queue_tail(&lapb->write_queue, skb);
351 lapb_kick(lapb);
352 rc = LAPB_OK;
353out_put:
354 lapb_put(lapb);
355out:
356 return rc;
357}
358
359int lapb_data_received(struct net_device *dev, struct sk_buff *skb)
360{
361 struct lapb_cb *lapb = lapb_devtostruct(dev);
362 int rc = LAPB_BADTOKEN;
363
364 if (lapb) {
365 lapb_data_input(lapb, skb);
366 lapb_put(lapb);
367 rc = LAPB_OK;
368 }
369
370 return rc;
371}
372
373void lapb_connect_confirmation(struct lapb_cb *lapb, int reason)
374{
375 if (lapb->callbacks->connect_confirmation)
376 lapb->callbacks->connect_confirmation(lapb->dev, reason);
377}
378
379void lapb_connect_indication(struct lapb_cb *lapb, int reason)
380{
381 if (lapb->callbacks->connect_indication)
382 lapb->callbacks->connect_indication(lapb->dev, reason);
383}
384
385void lapb_disconnect_confirmation(struct lapb_cb *lapb, int reason)
386{
387 if (lapb->callbacks->disconnect_confirmation)
388 lapb->callbacks->disconnect_confirmation(lapb->dev, reason);
389}
390
391void lapb_disconnect_indication(struct lapb_cb *lapb, int reason)
392{
393 if (lapb->callbacks->disconnect_indication)
394 lapb->callbacks->disconnect_indication(lapb->dev, reason);
395}
396
397int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *skb)
398{
399 if (lapb->callbacks->data_indication)
400 return lapb->callbacks->data_indication(lapb->dev, skb);
401
402 kfree_skb(skb);
403 return NET_RX_SUCCESS;
404}
405
406int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb)
407{
408 int used = 0;
409
410 if (lapb->callbacks->data_transmit) {
411 lapb->callbacks->data_transmit(lapb->dev, skb);
412 used = 1;
413 }
414
415 return used;
416}
417
418EXPORT_SYMBOL(lapb_register);
419EXPORT_SYMBOL(lapb_unregister);
420EXPORT_SYMBOL(lapb_getparms);
421EXPORT_SYMBOL(lapb_setparms);
422EXPORT_SYMBOL(lapb_connect_request);
423EXPORT_SYMBOL(lapb_disconnect_request);
424EXPORT_SYMBOL(lapb_data_request);
425EXPORT_SYMBOL(lapb_data_received);
426
427static int __init lapb_init(void)
428{
429 return 0;
430}
431
432static void __exit lapb_exit(void)
433{
434 WARN_ON(!list_empty(&lapb_list));
435}
436
437MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
438MODULE_DESCRIPTION("The X.25 Link Access Procedure B link layer protocol");
439MODULE_LICENSE("GPL");
440
441module_init(lapb_init);
442module_exit(lapb_exit);
443
