Merge tag 'usb-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
[linux-2.6-microblaze.git] / net / lapb / lapb_iface.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *      LAPB release 002
4  *
5  *      This code REQUIRES 2.1.15 or higher/ NET3.038
6  *
7  *      History
8  *      LAPB 001        Jonathan Naylor Started Coding
9  *      LAPB 002        Jonathan Naylor New timer architecture.
10  *      2000-10-29      Henner Eisen    lapb_data_indication() return status.
11  */
12
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
39 static LIST_HEAD(lapb_list);
40 static DEFINE_RWLOCK(lapb_list_lock);
41
42 /*
43  *      Free an allocated lapb control block.
44  */
45 static void lapb_free_cb(struct lapb_cb *lapb)
46 {
47         kfree(lapb);
48 }
49
50 static __inline__ void lapb_hold(struct lapb_cb *lapb)
51 {
52         refcount_inc(&lapb->refcnt);
53 }
54
55 static __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  *      Socket removal during an interrupt is now safe.
63  */
64 static 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  *      Add a socket to the bound sockets list.
74  */
75 static void __lapb_insert_cb(struct lapb_cb *lapb)
76 {
77         list_add(&lapb->node, &lapb_list);
78         lapb_hold(lapb);
79 }
80
81 static 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
100 static 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  *      Create an empty LAPB control block.
112  */
113 static 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);
133 out:
134         return lapb;
135 }
136
137 int 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;
164 out:
165         write_unlock_bh(&lapb_list_lock);
166         return rc;
167 }
168 EXPORT_SYMBOL(lapb_register);
169
170 int 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;
190 out:
191         write_unlock_bh(&lapb_list_lock);
192         return rc;
193 }
194 EXPORT_SYMBOL(lapb_unregister);
195
196 int 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;
224 out:
225         return rc;
226 }
227 EXPORT_SYMBOL(lapb_getparms);
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 EXPORT_SYMBOL(lapb_setparms);
264
265 int 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;
287 out_put:
288         lapb_put(lapb);
289 out:
290         return rc;
291 }
292 EXPORT_SYMBOL(lapb_connect_request);
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                 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;
332 out_put:
333         lapb_put(lapb);
334 out:
335         return rc;
336 }
337 EXPORT_SYMBOL(lapb_disconnect_request);
338
339 int 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;
354 out_put:
355         lapb_put(lapb);
356 out:
357         return rc;
358 }
359 EXPORT_SYMBOL(lapb_data_request);
360
361 int 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 }
374 EXPORT_SYMBOL(lapb_data_received);
375
376 void 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
382 void 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
388 void 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
394 void 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
400 int 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; /* For now; must be != NET_RX_DROP */
407 }
408
409 int 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
421 static int __init lapb_init(void)
422 {
423         return 0;
424 }
425
426 static void __exit lapb_exit(void)
427 {
428         WARN_ON(!list_empty(&lapb_list));
429 }
430
431 MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
432 MODULE_DESCRIPTION("The X.25 Link Access Procedure B link layer protocol");
433 MODULE_LICENSE("GPL");
434
435 module_init(lapb_init);
436 module_exit(lapb_exit);