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