dccp: Kill dead code and add static markers.
[linux-2.6.git] / net / lapb / lapb_iface.c
1 /*
2  *      LAPB release 002
3  *
4  *      This code REQUIRES 2.1.15 or higher/ NET3.038
5  *
6  *      This module:
7  *              This module is free software; you can redistribute it and/or
8  *              modify it under the terms of the GNU General Public License
9  *              as published by the Free Software Foundation; either version
10  *              2 of the License, or (at your option) any later version.
11  *
12  *      History
13  *      LAPB 001        Jonathan Naylor Started Coding
14  *      LAPB 002        Jonathan Naylor New timer architecture.
15  *      2000-10-29      Henner Eisen    lapb_data_indication() return status.
16  */
17
18 #include <linux/module.h>
19 #include <linux/errno.h>
20 #include <linux/types.h>
21 #include <linux/socket.h>
22 #include <linux/in.h>
23 #include <linux/kernel.h>
24 #include <linux/jiffies.h>
25 #include <linux/timer.h>
26 #include <linux/string.h>
27 #include <linux/sockios.h>
28 #include <linux/net.h>
29 #include <linux/inet.h>
30 #include <linux/if_arp.h>
31 #include <linux/skbuff.h>
32 #include <linux/slab.h>
33 #include <net/sock.h>
34 #include <asm/uaccess.h>
35 #include <asm/system.h>
36 #include <linux/fcntl.h>
37 #include <linux/mm.h>
38 #include <linux/interrupt.h>
39 #include <linux/stat.h>
40 #include <linux/init.h>
41 #include <net/lapb.h>
42
43 static LIST_HEAD(lapb_list);
44 static DEFINE_RWLOCK(lapb_list_lock);
45
46 /*
47  *      Free an allocated lapb control block.
48  */
49 static void lapb_free_cb(struct lapb_cb *lapb)
50 {
51         kfree(lapb);
52 }
53
54 static __inline__ void lapb_hold(struct lapb_cb *lapb)
55 {
56         atomic_inc(&lapb->refcnt);
57 }
58
59 static __inline__ void lapb_put(struct lapb_cb *lapb)
60 {
61         if (atomic_dec_and_test(&lapb->refcnt))
62                 lapb_free_cb(lapb);
63 }
64
65 /*
66  *      Socket removal during an interrupt is now safe.
67  */
68 static void __lapb_remove_cb(struct lapb_cb *lapb)
69 {
70         if (lapb->node.next) {
71                 list_del(&lapb->node);
72                 lapb_put(lapb);
73         }
74 }
75
76 /*
77  *      Add a socket to the bound sockets list.
78  */
79 static void __lapb_insert_cb(struct lapb_cb *lapb)
80 {
81         list_add(&lapb->node, &lapb_list);
82         lapb_hold(lapb);
83 }
84
85 static struct lapb_cb *__lapb_devtostruct(struct net_device *dev)
86 {
87         struct list_head *entry;
88         struct lapb_cb *lapb, *use = NULL;
89
90         list_for_each(entry, &lapb_list) {
91                 lapb = list_entry(entry, struct lapb_cb, node);
92                 if (lapb->dev == dev) {
93                         use = lapb;
94                         break;
95                 }
96         }
97
98         if (use)
99                 lapb_hold(use);
100
101         return use;
102 }
103
104 static struct lapb_cb *lapb_devtostruct(struct net_device *dev)
105 {
106         struct lapb_cb *rc;
107
108         read_lock_bh(&lapb_list_lock);
109         rc = __lapb_devtostruct(dev);
110         read_unlock_bh(&lapb_list_lock);
111
112         return rc;
113 }
114 /*
115  *      Create an empty LAPB control block.
116  */
117 static struct lapb_cb *lapb_create_cb(void)
118 {
119         struct lapb_cb *lapb = kzalloc(sizeof(*lapb), GFP_ATOMIC);
120
121
122         if (!lapb)
123                 goto out;
124
125         skb_queue_head_init(&lapb->write_queue);
126         skb_queue_head_init(&lapb->ack_queue);
127
128         init_timer(&lapb->t1timer);
129         init_timer(&lapb->t2timer);
130
131         lapb->t1      = LAPB_DEFAULT_T1;
132         lapb->t2      = LAPB_DEFAULT_T2;
133         lapb->n2      = LAPB_DEFAULT_N2;
134         lapb->mode    = LAPB_DEFAULT_MODE;
135         lapb->window  = LAPB_DEFAULT_WINDOW;
136         lapb->state   = LAPB_STATE_0;
137         atomic_set(&lapb->refcnt, 1);
138 out:
139         return lapb;
140 }
141
142 int lapb_register(struct net_device *dev, struct lapb_register_struct *callbacks)
143 {
144         struct lapb_cb *lapb;
145         int rc = LAPB_BADTOKEN;
146
147         write_lock_bh(&lapb_list_lock);
148
149         lapb = __lapb_devtostruct(dev);
150         if (lapb) {
151                 lapb_put(lapb);
152                 goto out;
153         }
154
155         lapb = lapb_create_cb();
156         rc = LAPB_NOMEM;
157         if (!lapb)
158                 goto out;
159
160         lapb->dev       = dev;
161         lapb->callbacks = *callbacks;
162
163         __lapb_insert_cb(lapb);
164
165         lapb_start_t1timer(lapb);
166
167         rc = LAPB_OK;
168 out:
169         write_unlock_bh(&lapb_list_lock);
170         return rc;
171 }
172
173 int lapb_unregister(struct net_device *dev)
174 {
175         struct lapb_cb *lapb;
176         int rc = LAPB_BADTOKEN;
177
178         write_lock_bh(&lapb_list_lock);
179         lapb = __lapb_devtostruct(dev);
180         if (!lapb)
181                 goto out;
182
183         lapb_stop_t1timer(lapb);
184         lapb_stop_t2timer(lapb);
185
186         lapb_clear_queues(lapb);
187
188         __lapb_remove_cb(lapb);
189
190         lapb_put(lapb);
191         rc = LAPB_OK;
192 out:
193         write_unlock_bh(&lapb_list_lock);
194         return rc;
195 }
196
197 int lapb_getparms(struct net_device *dev, struct lapb_parms_struct *parms)
198 {
199         int rc = LAPB_BADTOKEN;
200         struct lapb_cb *lapb = lapb_devtostruct(dev);
201
202         if (!lapb)
203                 goto out;
204
205         parms->t1      = lapb->t1 / HZ;
206         parms->t2      = lapb->t2 / HZ;
207         parms->n2      = lapb->n2;
208         parms->n2count = lapb->n2count;
209         parms->state   = lapb->state;
210         parms->window  = lapb->window;
211         parms->mode    = lapb->mode;
212
213         if (!timer_pending(&lapb->t1timer))
214                 parms->t1timer = 0;
215         else
216                 parms->t1timer = (lapb->t1timer.expires - jiffies) / HZ;
217
218         if (!timer_pending(&lapb->t2timer))
219                 parms->t2timer = 0;
220         else
221                 parms->t2timer = (lapb->t2timer.expires - jiffies) / HZ;
222
223         lapb_put(lapb);
224         rc = LAPB_OK;
225 out:
226         return rc;
227 }
228
229 int 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;
258 out_put:
259         lapb_put(lapb);
260 out:
261         return rc;
262 }
263
264 int lapb_connect_request(struct net_device *dev)
265 {
266         struct lapb_cb *lapb = lapb_devtostruct(dev);
267         int rc = LAPB_BADTOKEN;
268
269         if (!lapb)
270                 goto out;
271
272         rc = LAPB_OK;
273         if (lapb->state == LAPB_STATE_1)
274                 goto out_put;
275
276         rc = LAPB_CONNECTED;
277         if (lapb->state == LAPB_STATE_3 || lapb->state == LAPB_STATE_4)
278                 goto out_put;
279
280         lapb_establish_data_link(lapb);
281
282 #if LAPB_DEBUG > 0
283         printk(KERN_DEBUG "lapb: (%p) S0 -> S1\n", lapb->dev);
284 #endif
285         lapb->state = LAPB_STATE_1;
286
287         rc = LAPB_OK;
288 out_put:
289         lapb_put(lapb);
290 out:
291         return rc;
292 }
293
294 int 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 #if LAPB_DEBUG > 1
309                         printk(KERN_DEBUG "lapb: (%p) S1 TX DISC(1)\n", lapb->dev);
310 #endif
311 #if LAPB_DEBUG > 0
312                         printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->dev);
313 #endif
314                         lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
315                         lapb->state = LAPB_STATE_0;
316                         lapb_start_t1timer(lapb);
317                         rc = LAPB_NOTCONNECTED;
318                         goto out_put;
319
320                 case LAPB_STATE_2:
321                         rc = LAPB_OK;
322                         goto out_put;
323         }
324
325         lapb_clear_queues(lapb);
326         lapb->n2count = 0;
327         lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
328         lapb_start_t1timer(lapb);
329         lapb_stop_t2timer(lapb);
330         lapb->state = LAPB_STATE_2;
331
332 #if LAPB_DEBUG > 1
333         printk(KERN_DEBUG "lapb: (%p) S3 DISC(1)\n", lapb->dev);
334 #endif
335 #if LAPB_DEBUG > 0
336         printk(KERN_DEBUG "lapb: (%p) S3 -> S2\n", lapb->dev);
337 #endif
338
339         rc = LAPB_OK;
340 out_put:
341         lapb_put(lapb);
342 out:
343         return rc;
344 }
345
346 int lapb_data_request(struct net_device *dev, struct sk_buff *skb)
347 {
348         struct lapb_cb *lapb = lapb_devtostruct(dev);
349         int rc = LAPB_BADTOKEN;
350
351         if (!lapb)
352                 goto out;
353
354         rc = LAPB_NOTCONNECTED;
355         if (lapb->state != LAPB_STATE_3 && lapb->state != LAPB_STATE_4)
356                 goto out_put;
357
358         skb_queue_tail(&lapb->write_queue, skb);
359         lapb_kick(lapb);
360         rc = LAPB_OK;
361 out_put:
362         lapb_put(lapb);
363 out:
364         return rc;
365 }
366
367 int lapb_data_received(struct net_device *dev, struct sk_buff *skb)
368 {
369         struct lapb_cb *lapb = lapb_devtostruct(dev);
370         int rc = LAPB_BADTOKEN;
371
372         if (lapb) {
373                 lapb_data_input(lapb, skb);
374                 lapb_put(lapb);
375                 rc = LAPB_OK;
376         }
377
378         return rc;
379 }
380
381 void lapb_connect_confirmation(struct lapb_cb *lapb, int reason)
382 {
383         if (lapb->callbacks.connect_confirmation)
384                 lapb->callbacks.connect_confirmation(lapb->dev, reason);
385 }
386
387 void lapb_connect_indication(struct lapb_cb *lapb, int reason)
388 {
389         if (lapb->callbacks.connect_indication)
390                 lapb->callbacks.connect_indication(lapb->dev, reason);
391 }
392
393 void lapb_disconnect_confirmation(struct lapb_cb *lapb, int reason)
394 {
395         if (lapb->callbacks.disconnect_confirmation)
396                 lapb->callbacks.disconnect_confirmation(lapb->dev, reason);
397 }
398
399 void lapb_disconnect_indication(struct lapb_cb *lapb, int reason)
400 {
401         if (lapb->callbacks.disconnect_indication)
402                 lapb->callbacks.disconnect_indication(lapb->dev, reason);
403 }
404
405 int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *skb)
406 {
407         if (lapb->callbacks.data_indication)
408                 return lapb->callbacks.data_indication(lapb->dev, skb);
409
410         kfree_skb(skb);
411         return NET_RX_SUCCESS; /* For now; must be != NET_RX_DROP */
412 }
413
414 int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb)
415 {
416         int used = 0;
417
418         if (lapb->callbacks.data_transmit) {
419                 lapb->callbacks.data_transmit(lapb->dev, skb);
420                 used = 1;
421         }
422
423         return used;
424 }
425
426 EXPORT_SYMBOL(lapb_register);
427 EXPORT_SYMBOL(lapb_unregister);
428 EXPORT_SYMBOL(lapb_getparms);
429 EXPORT_SYMBOL(lapb_setparms);
430 EXPORT_SYMBOL(lapb_connect_request);
431 EXPORT_SYMBOL(lapb_disconnect_request);
432 EXPORT_SYMBOL(lapb_data_request);
433 EXPORT_SYMBOL(lapb_data_received);
434
435 static int __init lapb_init(void)
436 {
437         return 0;
438 }
439
440 static void __exit lapb_exit(void)
441 {
442         WARN_ON(!list_empty(&lapb_list));
443 }
444
445 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
446 MODULE_DESCRIPTION("The X.25 Link Access Procedure B link layer protocol");
447 MODULE_LICENSE("GPL");
448
449 module_init(lapb_init);
450 module_exit(lapb_exit);