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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 Naulor 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/errno.h>
19#include <linux/types.h>
20#include <linux/socket.h>
21#include <linux/in.h>
22#include <linux/kernel.h>
23#include <linux/timer.h>
24#include <linux/string.h>
25#include <linux/sockios.h>
26#include <linux/net.h>
27#include <linux/inet.h>
28#include <linux/netdevice.h>
29#include <linux/skbuff.h>
30#include <linux/slab.h>
31#include <net/sock.h>
32#include <asm/uaccess.h>
33#include <asm/system.h>
34#include <linux/fcntl.h>
35#include <linux/mm.h>
36#include <linux/interrupt.h>
37#include <net/lapb.h>
38
39/*
40 * State machine for state 0, Disconnected State.
41 * The handling of the timer(s) is in file lapb_timer.c.
42 */
43static void lapb_state0_machine(struct lapb_cb *lapb, struct sk_buff *skb,
44 struct lapb_frame *frame)
45{
46 switch (frame->type) {
47 case LAPB_SABM:
48#if LAPB_DEBUG > 1
49 printk(KERN_DEBUG "lapb: (%p) S0 RX SABM(%d)\n",
50 lapb->dev, frame->pf);
51#endif
52 if (lapb->mode & LAPB_EXTENDED) {
53#if LAPB_DEBUG > 1
54 printk(KERN_DEBUG "lapb: (%p) S0 TX DM(%d)\n",
55 lapb->dev, frame->pf);
56#endif
57 lapb_send_control(lapb, LAPB_DM, frame->pf,
58 LAPB_RESPONSE);
59 } else {
60#if LAPB_DEBUG > 1
61 printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n",
62 lapb->dev, frame->pf);
63#endif
64#if LAPB_DEBUG > 0
65 printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n", lapb->dev);
66#endif
67 lapb_send_control(lapb, LAPB_UA, frame->pf,
68 LAPB_RESPONSE);
69 lapb_stop_t1timer(lapb);
70 lapb_stop_t2timer(lapb);
71 lapb->state = LAPB_STATE_3;
72 lapb->condition = 0x00;
73 lapb->n2count = 0;
74 lapb->vs = 0;
75 lapb->vr = 0;
76 lapb->va = 0;
77 lapb_connect_indication(lapb, LAPB_OK);
78 }
79 break;
80
81 case LAPB_SABME:
82#if LAPB_DEBUG > 1
83 printk(KERN_DEBUG "lapb: (%p) S0 RX SABME(%d)\n",
84 lapb->dev, frame->pf);
85#endif
86 if (lapb->mode & LAPB_EXTENDED) {
87#if LAPB_DEBUG > 1
88 printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n",
89 lapb->dev, frame->pf);
90#endif
91#if LAPB_DEBUG > 0
92 printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n", lapb->dev);
93#endif
94 lapb_send_control(lapb, LAPB_UA, frame->pf,
95 LAPB_RESPONSE);
96 lapb_stop_t1timer(lapb);
97 lapb_stop_t2timer(lapb);
98 lapb->state = LAPB_STATE_3;
99 lapb->condition = 0x00;
100 lapb->n2count = 0;
101 lapb->vs = 0;
102 lapb->vr = 0;
103 lapb->va = 0;
104 lapb_connect_indication(lapb, LAPB_OK);
105 } else {
106#if LAPB_DEBUG > 1
107 printk(KERN_DEBUG "lapb: (%p) S0 TX DM(%d)\n",
108 lapb->dev, frame->pf);
109#endif
110 lapb_send_control(lapb, LAPB_DM, frame->pf,
111 LAPB_RESPONSE);
112 }
113 break;
114
115 case LAPB_DISC:
116#if LAPB_DEBUG > 1
117 printk(KERN_DEBUG "lapb: (%p) S0 RX DISC(%d)\n",
118 lapb->dev, frame->pf);
119 printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n",
120 lapb->dev, frame->pf);
121#endif
122 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
123 break;
124
125 default:
126 break;
127 }
128
129 kfree_skb(skb);
130}
131
132/*
133 * State machine for state 1, Awaiting Connection State.
134 * The handling of the timer(s) is in file lapb_timer.c.
135 */
136static void lapb_state1_machine(struct lapb_cb *lapb, struct sk_buff *skb,
137 struct lapb_frame *frame)
138{
139 switch (frame->type) {
140 case LAPB_SABM:
141#if LAPB_DEBUG > 1
142 printk(KERN_DEBUG "lapb: (%p) S1 RX SABM(%d)\n",
143 lapb->dev, frame->pf);
144#endif
145 if (lapb->mode & LAPB_EXTENDED) {
146#if LAPB_DEBUG > 1
147 printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n",
148 lapb->dev, frame->pf);
149#endif
150 lapb_send_control(lapb, LAPB_DM, frame->pf,
151 LAPB_RESPONSE);
152 } else {
153#if LAPB_DEBUG > 1
154 printk(KERN_DEBUG "lapb: (%p) S1 TX UA(%d)\n",
155 lapb->dev, frame->pf);
156#endif
157 lapb_send_control(lapb, LAPB_UA, frame->pf,
158 LAPB_RESPONSE);
159 }
160 break;
161
162 case LAPB_SABME:
163#if LAPB_DEBUG > 1
164 printk(KERN_DEBUG "lapb: (%p) S1 RX SABME(%d)\n",
165 lapb->dev, frame->pf);
166#endif
167 if (lapb->mode & LAPB_EXTENDED) {
168#if LAPB_DEBUG > 1
169 printk(KERN_DEBUG "lapb: (%p) S1 TX UA(%d)\n",
170 lapb->dev, frame->pf);
171#endif
172 lapb_send_control(lapb, LAPB_UA, frame->pf,
173 LAPB_RESPONSE);
174 } else {
175#if LAPB_DEBUG > 1
176 printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n",
177 lapb->dev, frame->pf);
178#endif
179 lapb_send_control(lapb, LAPB_DM, frame->pf,
180 LAPB_RESPONSE);
181 }
182 break;
183
184 case LAPB_DISC:
185#if LAPB_DEBUG > 1
186 printk(KERN_DEBUG "lapb: (%p) S1 RX DISC(%d)\n",
187 lapb->dev, frame->pf);
188 printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n",
189 lapb->dev, frame->pf);
190#endif
191 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
192 break;
193
194 case LAPB_UA:
195#if LAPB_DEBUG > 1
196 printk(KERN_DEBUG "lapb: (%p) S1 RX UA(%d)\n",
197 lapb->dev, frame->pf);
198#endif
199 if (frame->pf) {
200#if LAPB_DEBUG > 0
201 printk(KERN_DEBUG "lapb: (%p) S1 -> S3\n", lapb->dev);
202#endif
203 lapb_stop_t1timer(lapb);
204 lapb_stop_t2timer(lapb);
205 lapb->state = LAPB_STATE_3;
206 lapb->condition = 0x00;
207 lapb->n2count = 0;
208 lapb->vs = 0;
209 lapb->vr = 0;
210 lapb->va = 0;
211 lapb_connect_confirmation(lapb, LAPB_OK);
212 }
213 break;
214
215 case LAPB_DM:
216#if LAPB_DEBUG > 1
217 printk(KERN_DEBUG "lapb: (%p) S1 RX DM(%d)\n",
218 lapb->dev, frame->pf);
219#endif
220 if (frame->pf) {
221#if LAPB_DEBUG > 0
222 printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->dev);
223#endif
224 lapb_clear_queues(lapb);
225 lapb->state = LAPB_STATE_0;
226 lapb_start_t1timer(lapb);
227 lapb_stop_t2timer(lapb);
228 lapb_disconnect_indication(lapb, LAPB_REFUSED);
229 }
230 break;
231 }
232
233 kfree_skb(skb);
234}
235
236/*
237 * State machine for state 2, Awaiting Release State.
238 * The handling of the timer(s) is in file lapb_timer.c
239 */
240static void lapb_state2_machine(struct lapb_cb *lapb, struct sk_buff *skb,
241 struct lapb_frame *frame)
242{
243 switch (frame->type) {
244 case LAPB_SABM:
245 case LAPB_SABME:
246#if LAPB_DEBUG > 1
247 printk(KERN_DEBUG "lapb: (%p) S2 RX {SABM,SABME}(%d)\n",
248 lapb->dev, frame->pf);
249 printk(KERN_DEBUG "lapb: (%p) S2 TX DM(%d)\n",
250 lapb->dev, frame->pf);
251#endif
252 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
253 break;
254
255 case LAPB_DISC:
256#if LAPB_DEBUG > 1
257 printk(KERN_DEBUG "lapb: (%p) S2 RX DISC(%d)\n",
258 lapb->dev, frame->pf);
259 printk(KERN_DEBUG "lapb: (%p) S2 TX UA(%d)\n",
260 lapb->dev, frame->pf);
261#endif
262 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
263 break;
264
265 case LAPB_UA:
266#if LAPB_DEBUG > 1
267 printk(KERN_DEBUG "lapb: (%p) S2 RX UA(%d)\n",
268 lapb->dev, frame->pf);
269#endif
270 if (frame->pf) {
271#if LAPB_DEBUG > 0
272 printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->dev);
273#endif
274 lapb->state = LAPB_STATE_0;
275 lapb_start_t1timer(lapb);
276 lapb_stop_t2timer(lapb);
277 lapb_disconnect_confirmation(lapb, LAPB_OK);
278 }
279 break;
280
281 case LAPB_DM:
282#if LAPB_DEBUG > 1
283 printk(KERN_DEBUG "lapb: (%p) S2 RX DM(%d)\n",
284 lapb->dev, frame->pf);
285#endif
286 if (frame->pf) {
287#if LAPB_DEBUG > 0
288 printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->dev);
289#endif
290 lapb->state = LAPB_STATE_0;
291 lapb_start_t1timer(lapb);
292 lapb_stop_t2timer(lapb);
293 lapb_disconnect_confirmation(lapb, LAPB_NOTCONNECTED);
294 }
295 break;
296
297 case LAPB_I:
298 case LAPB_REJ:
299 case LAPB_RNR:
300 case LAPB_RR:
301#if LAPB_DEBUG > 1
302 printk(KERN_DEBUG "lapb: (%p) S2 RX {I,REJ,RNR,RR}(%d)\n",
303 lapb->dev, frame->pf);
304 printk(KERN_DEBUG "lapb: (%p) S2 RX DM(%d)\n",
305 lapb->dev, frame->pf);
306#endif
307 if (frame->pf)
308 lapb_send_control(lapb, LAPB_DM, frame->pf,
309 LAPB_RESPONSE);
310 break;
311 }
312
313 kfree_skb(skb);
314}
315
316/*
317 * State machine for state 3, Connected State.
318 * The handling of the timer(s) is in file lapb_timer.c
319 */
320static void lapb_state3_machine(struct lapb_cb *lapb, struct sk_buff *skb,
321 struct lapb_frame *frame)
322{
323 int queued = 0;
324 int modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS :
325 LAPB_SMODULUS;
326
327 switch (frame->type) {
328 case LAPB_SABM:
329#if LAPB_DEBUG > 1
330 printk(KERN_DEBUG "lapb: (%p) S3 RX SABM(%d)\n",
331 lapb->dev, frame->pf);
332#endif
333 if (lapb->mode & LAPB_EXTENDED) {
334#if LAPB_DEBUG > 1
335 printk(KERN_DEBUG "lapb: (%p) S3 TX DM(%d)\n",
336 lapb->dev, frame->pf);
337#endif
338 lapb_send_control(lapb, LAPB_DM, frame->pf,
339 LAPB_RESPONSE);
340 } else {
341#if LAPB_DEBUG > 1
342 printk(KERN_DEBUG "lapb: (%p) S3 TX UA(%d)\n",
343 lapb->dev, frame->pf);
344#endif
345 lapb_send_control(lapb, LAPB_UA, frame->pf,
346 LAPB_RESPONSE);
347 lapb_stop_t1timer(lapb);
348 lapb_stop_t2timer(lapb);
349 lapb->condition = 0x00;
350 lapb->n2count = 0;
351 lapb->vs = 0;
352 lapb->vr = 0;
353 lapb->va = 0;
354 lapb_requeue_frames(lapb);
355 }
356 break;
357
358 case LAPB_SABME:
359#if LAPB_DEBUG > 1
360 printk(KERN_DEBUG "lapb: (%p) S3 RX SABME(%d)\n",
361 lapb->dev, frame->pf);
362#endif
363 if (lapb->mode & LAPB_EXTENDED) {
364#if LAPB_DEBUG > 1
365 printk(KERN_DEBUG "lapb: (%p) S3 TX UA(%d)\n",
366 lapb->dev, frame->pf);
367#endif
368 lapb_send_control(lapb, LAPB_UA, frame->pf,
369 LAPB_RESPONSE);
370 lapb_stop_t1timer(lapb);
371 lapb_stop_t2timer(lapb);
372 lapb->condition = 0x00;
373 lapb->n2count = 0;
374 lapb->vs = 0;
375 lapb->vr = 0;
376 lapb->va = 0;
377 lapb_requeue_frames(lapb);
378 } else {
379#if LAPB_DEBUG > 1
380 printk(KERN_DEBUG "lapb: (%p) S3 TX DM(%d)\n",
381 lapb->dev, frame->pf);
382#endif
383 lapb_send_control(lapb, LAPB_DM, frame->pf,
384 LAPB_RESPONSE);
385 }
386 break;
387
388 case LAPB_DISC:
389#if LAPB_DEBUG > 1
390 printk(KERN_DEBUG "lapb: (%p) S3 RX DISC(%d)\n",
391 lapb->dev, frame->pf);
392#endif
393#if LAPB_DEBUG > 0
394 printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->dev);
395#endif
396 lapb_clear_queues(lapb);
397 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
398 lapb_start_t1timer(lapb);
399 lapb_stop_t2timer(lapb);
400 lapb->state = LAPB_STATE_0;
401 lapb_disconnect_indication(lapb, LAPB_OK);
402 break;
403
404 case LAPB_DM:
405#if LAPB_DEBUG > 1
406 printk(KERN_DEBUG "lapb: (%p) S3 RX DM(%d)\n",
407 lapb->dev, frame->pf);
408#endif
409#if LAPB_DEBUG > 0
410 printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->dev);
411#endif
412 lapb_clear_queues(lapb);
413 lapb->state = LAPB_STATE_0;
414 lapb_start_t1timer(lapb);
415 lapb_stop_t2timer(lapb);
416 lapb_disconnect_indication(lapb, LAPB_NOTCONNECTED);
417 break;
418
419 case LAPB_RNR:
420#if LAPB_DEBUG > 1
421 printk(KERN_DEBUG "lapb: (%p) S3 RX RNR(%d) R%d\n",
422 lapb->dev, frame->pf, frame->nr);
423#endif
424 lapb->condition |= LAPB_PEER_RX_BUSY_CONDITION;
425 lapb_check_need_response(lapb, frame->cr, frame->pf);
426 if (lapb_validate_nr(lapb, frame->nr)) {
427 lapb_check_iframes_acked(lapb, frame->nr);
428 } else {
429 lapb->frmr_data = *frame;
430 lapb->frmr_type = LAPB_FRMR_Z;
431 lapb_transmit_frmr(lapb);
432#if LAPB_DEBUG > 0
433 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
434#endif
435 lapb_start_t1timer(lapb);
436 lapb_stop_t2timer(lapb);
437 lapb->state = LAPB_STATE_4;
438 lapb->n2count = 0;
439 }
440 break;
441
442 case LAPB_RR:
443#if LAPB_DEBUG > 1
444 printk(KERN_DEBUG "lapb: (%p) S3 RX RR(%d) R%d\n",
445 lapb->dev, frame->pf, frame->nr);
446#endif
447 lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
448 lapb_check_need_response(lapb, frame->cr, frame->pf);
449 if (lapb_validate_nr(lapb, frame->nr)) {
450 lapb_check_iframes_acked(lapb, frame->nr);
451 } else {
452 lapb->frmr_data = *frame;
453 lapb->frmr_type = LAPB_FRMR_Z;
454 lapb_transmit_frmr(lapb);
455#if LAPB_DEBUG > 0
456 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
457#endif
458 lapb_start_t1timer(lapb);
459 lapb_stop_t2timer(lapb);
460 lapb->state = LAPB_STATE_4;
461 lapb->n2count = 0;
462 }
463 break;
464
465 case LAPB_REJ:
466#if LAPB_DEBUG > 1
467 printk(KERN_DEBUG "lapb: (%p) S3 RX REJ(%d) R%d\n",
468 lapb->dev, frame->pf, frame->nr);
469#endif
470 lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
471 lapb_check_need_response(lapb, frame->cr, frame->pf);
472 if (lapb_validate_nr(lapb, frame->nr)) {
473 lapb_frames_acked(lapb, frame->nr);
474 lapb_stop_t1timer(lapb);
475 lapb->n2count = 0;
476 lapb_requeue_frames(lapb);
477 } else {
478 lapb->frmr_data = *frame;
479 lapb->frmr_type = LAPB_FRMR_Z;
480 lapb_transmit_frmr(lapb);
481#if LAPB_DEBUG > 0
482 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
483#endif
484 lapb_start_t1timer(lapb);
485 lapb_stop_t2timer(lapb);
486 lapb->state = LAPB_STATE_4;
487 lapb->n2count = 0;
488 }
489 break;
490
491 case LAPB_I:
492#if LAPB_DEBUG > 1
493 printk(KERN_DEBUG "lapb: (%p) S3 RX I(%d) S%d R%d\n",
494 lapb->dev, frame->pf, frame->ns, frame->nr);
495#endif
496 if (!lapb_validate_nr(lapb, frame->nr)) {
497 lapb->frmr_data = *frame;
498 lapb->frmr_type = LAPB_FRMR_Z;
499 lapb_transmit_frmr(lapb);
500#if LAPB_DEBUG > 0
501 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
502#endif
503 lapb_start_t1timer(lapb);
504 lapb_stop_t2timer(lapb);
505 lapb->state = LAPB_STATE_4;
506 lapb->n2count = 0;
507 break;
508 }
509 if (lapb->condition & LAPB_PEER_RX_BUSY_CONDITION)
510 lapb_frames_acked(lapb, frame->nr);
511 else
512 lapb_check_iframes_acked(lapb, frame->nr);
513
514 if (frame->ns == lapb->vr) {
515 int cn;
516 cn = lapb_data_indication(lapb, skb);
517 queued = 1;
518 /*
519 * If upper layer has dropped the frame, we
520 * basically ignore any further protocol
521 * processing. This will cause the peer
522 * to re-transmit the frame later like
523 * a frame lost on the wire.
524 */
525 if (cn == NET_RX_DROP) {
526 printk(KERN_DEBUG "LAPB: rx congestion\n");
527 break;
528 }
529 lapb->vr = (lapb->vr + 1) % modulus;
530 lapb->condition &= ~LAPB_REJECT_CONDITION;
531 if (frame->pf)
532 lapb_enquiry_response(lapb);
533 else {
534 if (!(lapb->condition &
535 LAPB_ACK_PENDING_CONDITION)) {
536 lapb->condition |= LAPB_ACK_PENDING_CONDITION;
537 lapb_start_t2timer(lapb);
538 }
539 }
540 } else {
541 if (lapb->condition & LAPB_REJECT_CONDITION) {
542 if (frame->pf)
543 lapb_enquiry_response(lapb);
544 } else {
545#if LAPB_DEBUG > 1
546 printk(KERN_DEBUG
547 "lapb: (%p) S3 TX REJ(%d) R%d\n",
548 lapb->dev, frame->pf, lapb->vr);
549#endif
550 lapb->condition |= LAPB_REJECT_CONDITION;
551 lapb_send_control(lapb, LAPB_REJ, frame->pf,
552 LAPB_RESPONSE);
553 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
554 }
555 }
556 break;
557
558 case LAPB_FRMR:
559#if LAPB_DEBUG > 1
560 printk(KERN_DEBUG "lapb: (%p) S3 RX FRMR(%d) %02X "
561 "%02X %02X %02X %02X\n", lapb->dev, frame->pf,
562 skb->data[0], skb->data[1], skb->data[2],
563 skb->data[3], skb->data[4]);
564#endif
565 lapb_establish_data_link(lapb);
566#if LAPB_DEBUG > 0
567 printk(KERN_DEBUG "lapb: (%p) S3 -> S1\n", lapb->dev);
568#endif
569 lapb_requeue_frames(lapb);
570 lapb->state = LAPB_STATE_1;
571 break;
572
573 case LAPB_ILLEGAL:
574#if LAPB_DEBUG > 1
575 printk(KERN_DEBUG "lapb: (%p) S3 RX ILLEGAL(%d)\n",
576 lapb->dev, frame->pf);
577#endif
578 lapb->frmr_data = *frame;
579 lapb->frmr_type = LAPB_FRMR_W;
580 lapb_transmit_frmr(lapb);
581#if LAPB_DEBUG > 0
582 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
583#endif
584 lapb_start_t1timer(lapb);
585 lapb_stop_t2timer(lapb);
586 lapb->state = LAPB_STATE_4;
587 lapb->n2count = 0;
588 break;
589 }
590
591 if (!queued)
592 kfree_skb(skb);
593}
594
595/*
596 * State machine for state 4, Frame Reject State.
597 * The handling of the timer(s) is in file lapb_timer.c.
598 */
599static void lapb_state4_machine(struct lapb_cb *lapb, struct sk_buff *skb,
600 struct lapb_frame *frame)
601{
602 switch (frame->type) {
603 case LAPB_SABM:
604#if LAPB_DEBUG > 1
605 printk(KERN_DEBUG "lapb: (%p) S4 RX SABM(%d)\n",
606 lapb->dev, frame->pf);
607#endif
608 if (lapb->mode & LAPB_EXTENDED) {
609#if LAPB_DEBUG > 1
610 printk(KERN_DEBUG "lapb: (%p) S4 TX DM(%d)\n",
611 lapb->dev, frame->pf);
612#endif
613 lapb_send_control(lapb, LAPB_DM, frame->pf,
614 LAPB_RESPONSE);
615 } else {
616#if LAPB_DEBUG > 1
617 printk(KERN_DEBUG "lapb: (%p) S4 TX UA(%d)\n",
618 lapb->dev, frame->pf);
619#endif
620#if LAPB_DEBUG > 0
621 printk(KERN_DEBUG "lapb: (%p) S4 -> S3\n", lapb->dev);
622#endif
623 lapb_send_control(lapb, LAPB_UA, frame->pf,
624 LAPB_RESPONSE);
625 lapb_stop_t1timer(lapb);
626 lapb_stop_t2timer(lapb);
627 lapb->state = LAPB_STATE_3;
628 lapb->condition = 0x00;
629 lapb->n2count = 0;
630 lapb->vs = 0;
631 lapb->vr = 0;
632 lapb->va = 0;
633 lapb_connect_indication(lapb, LAPB_OK);
634 }
635 break;
636
637 case LAPB_SABME:
638#if LAPB_DEBUG > 1
639 printk(KERN_DEBUG "lapb: (%p) S4 RX SABME(%d)\n",
640 lapb->dev, frame->pf);
641#endif
642 if (lapb->mode & LAPB_EXTENDED) {
643#if LAPB_DEBUG > 1
644 printk(KERN_DEBUG "lapb: (%p) S4 TX UA(%d)\n",
645 lapb->dev, frame->pf);
646#endif
647#if LAPB_DEBUG > 0
648 printk(KERN_DEBUG "lapb: (%p) S4 -> S3\n", lapb->dev);
649#endif
650 lapb_send_control(lapb, LAPB_UA, frame->pf,
651 LAPB_RESPONSE);
652 lapb_stop_t1timer(lapb);
653 lapb_stop_t2timer(lapb);
654 lapb->state = LAPB_STATE_3;
655 lapb->condition = 0x00;
656 lapb->n2count = 0;
657 lapb->vs = 0;
658 lapb->vr = 0;
659 lapb->va = 0;
660 lapb_connect_indication(lapb, LAPB_OK);
661 } else {
662#if LAPB_DEBUG > 1
663 printk(KERN_DEBUG "lapb: (%p) S4 TX DM(%d)\n",
664 lapb->dev, frame->pf);
665#endif
666 lapb_send_control(lapb, LAPB_DM, frame->pf,
667 LAPB_RESPONSE);
668 }
669 break;
670 }
671
672 kfree_skb(skb);
673}
674
675/*
676 * Process an incoming LAPB frame
677 */
678void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *skb)
679{
680 struct lapb_frame frame;
681
682 if (lapb_decode(lapb, skb, &frame) < 0) {
683 kfree_skb(skb);
684 return;
685 }
686
687 switch (lapb->state) {
688 case LAPB_STATE_0:
689 lapb_state0_machine(lapb, skb, &frame); break;
690 case LAPB_STATE_1:
691 lapb_state1_machine(lapb, skb, &frame); break;
692 case LAPB_STATE_2:
693 lapb_state2_machine(lapb, skb, &frame); break;
694 case LAPB_STATE_3:
695 lapb_state3_machine(lapb, skb, &frame); break;
696 case LAPB_STATE_4:
697 lapb_state4_machine(lapb, skb, &frame); break;
698 }
699
700 lapb_kick(lapb);
701}
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 Naulor Started Coding
14 * LAPB 002 Jonathan Naylor New timer architecture.
15 * 2000-10-29 Henner Eisen lapb_data_indication() return status.
16 */
17
18#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
19
20#include <linux/errno.h>
21#include <linux/types.h>
22#include <linux/socket.h>
23#include <linux/in.h>
24#include <linux/kernel.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/netdevice.h>
31#include <linux/skbuff.h>
32#include <linux/slab.h>
33#include <net/sock.h>
34#include <asm/uaccess.h>
35#include <linux/fcntl.h>
36#include <linux/mm.h>
37#include <linux/interrupt.h>
38#include <net/lapb.h>
39
40/*
41 * State machine for state 0, Disconnected State.
42 * The handling of the timer(s) is in file lapb_timer.c.
43 */
44static void lapb_state0_machine(struct lapb_cb *lapb, struct sk_buff *skb,
45 struct lapb_frame *frame)
46{
47 switch (frame->type) {
48 case LAPB_SABM:
49 lapb_dbg(1, "(%p) S0 RX SABM(%d)\n", lapb->dev, frame->pf);
50 if (lapb->mode & LAPB_EXTENDED) {
51 lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
52 lapb->dev, frame->pf);
53 lapb_send_control(lapb, LAPB_DM, frame->pf,
54 LAPB_RESPONSE);
55 } else {
56 lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
57 lapb->dev, frame->pf);
58 lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
59 lapb_send_control(lapb, LAPB_UA, frame->pf,
60 LAPB_RESPONSE);
61 lapb_stop_t1timer(lapb);
62 lapb_stop_t2timer(lapb);
63 lapb->state = LAPB_STATE_3;
64 lapb->condition = 0x00;
65 lapb->n2count = 0;
66 lapb->vs = 0;
67 lapb->vr = 0;
68 lapb->va = 0;
69 lapb_connect_indication(lapb, LAPB_OK);
70 }
71 break;
72
73 case LAPB_SABME:
74 lapb_dbg(1, "(%p) S0 RX SABME(%d)\n", lapb->dev, frame->pf);
75 if (lapb->mode & LAPB_EXTENDED) {
76 lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
77 lapb->dev, frame->pf);
78 lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
79 lapb_send_control(lapb, LAPB_UA, frame->pf,
80 LAPB_RESPONSE);
81 lapb_stop_t1timer(lapb);
82 lapb_stop_t2timer(lapb);
83 lapb->state = LAPB_STATE_3;
84 lapb->condition = 0x00;
85 lapb->n2count = 0;
86 lapb->vs = 0;
87 lapb->vr = 0;
88 lapb->va = 0;
89 lapb_connect_indication(lapb, LAPB_OK);
90 } else {
91 lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
92 lapb->dev, frame->pf);
93 lapb_send_control(lapb, LAPB_DM, frame->pf,
94 LAPB_RESPONSE);
95 }
96 break;
97
98 case LAPB_DISC:
99 lapb_dbg(1, "(%p) S0 RX DISC(%d)\n", lapb->dev, frame->pf);
100 lapb_dbg(1, "(%p) S0 TX UA(%d)\n", lapb->dev, frame->pf);
101 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
102 break;
103
104 default:
105 break;
106 }
107
108 kfree_skb(skb);
109}
110
111/*
112 * State machine for state 1, Awaiting Connection State.
113 * The handling of the timer(s) is in file lapb_timer.c.
114 */
115static void lapb_state1_machine(struct lapb_cb *lapb, struct sk_buff *skb,
116 struct lapb_frame *frame)
117{
118 switch (frame->type) {
119 case LAPB_SABM:
120 lapb_dbg(1, "(%p) S1 RX SABM(%d)\n", lapb->dev, frame->pf);
121 if (lapb->mode & LAPB_EXTENDED) {
122 lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
123 lapb->dev, frame->pf);
124 lapb_send_control(lapb, LAPB_DM, frame->pf,
125 LAPB_RESPONSE);
126 } else {
127 lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
128 lapb->dev, frame->pf);
129 lapb_send_control(lapb, LAPB_UA, frame->pf,
130 LAPB_RESPONSE);
131 }
132 break;
133
134 case LAPB_SABME:
135 lapb_dbg(1, "(%p) S1 RX SABME(%d)\n", lapb->dev, frame->pf);
136 if (lapb->mode & LAPB_EXTENDED) {
137 lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
138 lapb->dev, frame->pf);
139 lapb_send_control(lapb, LAPB_UA, frame->pf,
140 LAPB_RESPONSE);
141 } else {
142 lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
143 lapb->dev, frame->pf);
144 lapb_send_control(lapb, LAPB_DM, frame->pf,
145 LAPB_RESPONSE);
146 }
147 break;
148
149 case LAPB_DISC:
150 lapb_dbg(1, "(%p) S1 RX DISC(%d)\n", lapb->dev, frame->pf);
151 lapb_dbg(1, "(%p) S1 TX DM(%d)\n", lapb->dev, frame->pf);
152 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
153 break;
154
155 case LAPB_UA:
156 lapb_dbg(1, "(%p) S1 RX UA(%d)\n", lapb->dev, frame->pf);
157 if (frame->pf) {
158 lapb_dbg(0, "(%p) S1 -> S3\n", lapb->dev);
159 lapb_stop_t1timer(lapb);
160 lapb_stop_t2timer(lapb);
161 lapb->state = LAPB_STATE_3;
162 lapb->condition = 0x00;
163 lapb->n2count = 0;
164 lapb->vs = 0;
165 lapb->vr = 0;
166 lapb->va = 0;
167 lapb_connect_confirmation(lapb, LAPB_OK);
168 }
169 break;
170
171 case LAPB_DM:
172 lapb_dbg(1, "(%p) S1 RX DM(%d)\n", lapb->dev, frame->pf);
173 if (frame->pf) {
174 lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
175 lapb_clear_queues(lapb);
176 lapb->state = LAPB_STATE_0;
177 lapb_start_t1timer(lapb);
178 lapb_stop_t2timer(lapb);
179 lapb_disconnect_indication(lapb, LAPB_REFUSED);
180 }
181 break;
182 }
183
184 kfree_skb(skb);
185}
186
187/*
188 * State machine for state 2, Awaiting Release State.
189 * The handling of the timer(s) is in file lapb_timer.c
190 */
191static void lapb_state2_machine(struct lapb_cb *lapb, struct sk_buff *skb,
192 struct lapb_frame *frame)
193{
194 switch (frame->type) {
195 case LAPB_SABM:
196 case LAPB_SABME:
197 lapb_dbg(1, "(%p) S2 RX {SABM,SABME}(%d)\n",
198 lapb->dev, frame->pf);
199 lapb_dbg(1, "(%p) S2 TX DM(%d)\n", lapb->dev, frame->pf);
200 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
201 break;
202
203 case LAPB_DISC:
204 lapb_dbg(1, "(%p) S2 RX DISC(%d)\n", lapb->dev, frame->pf);
205 lapb_dbg(1, "(%p) S2 TX UA(%d)\n", lapb->dev, frame->pf);
206 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
207 break;
208
209 case LAPB_UA:
210 lapb_dbg(1, "(%p) S2 RX UA(%d)\n", lapb->dev, frame->pf);
211 if (frame->pf) {
212 lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
213 lapb->state = LAPB_STATE_0;
214 lapb_start_t1timer(lapb);
215 lapb_stop_t2timer(lapb);
216 lapb_disconnect_confirmation(lapb, LAPB_OK);
217 }
218 break;
219
220 case LAPB_DM:
221 lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
222 if (frame->pf) {
223 lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
224 lapb->state = LAPB_STATE_0;
225 lapb_start_t1timer(lapb);
226 lapb_stop_t2timer(lapb);
227 lapb_disconnect_confirmation(lapb, LAPB_NOTCONNECTED);
228 }
229 break;
230
231 case LAPB_I:
232 case LAPB_REJ:
233 case LAPB_RNR:
234 case LAPB_RR:
235 lapb_dbg(1, "(%p) S2 RX {I,REJ,RNR,RR}(%d)\n",
236 lapb->dev, frame->pf);
237 lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
238 if (frame->pf)
239 lapb_send_control(lapb, LAPB_DM, frame->pf,
240 LAPB_RESPONSE);
241 break;
242 }
243
244 kfree_skb(skb);
245}
246
247/*
248 * State machine for state 3, Connected State.
249 * The handling of the timer(s) is in file lapb_timer.c
250 */
251static void lapb_state3_machine(struct lapb_cb *lapb, struct sk_buff *skb,
252 struct lapb_frame *frame)
253{
254 int queued = 0;
255 int modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS :
256 LAPB_SMODULUS;
257
258 switch (frame->type) {
259 case LAPB_SABM:
260 lapb_dbg(1, "(%p) S3 RX SABM(%d)\n", lapb->dev, frame->pf);
261 if (lapb->mode & LAPB_EXTENDED) {
262 lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
263 lapb->dev, frame->pf);
264 lapb_send_control(lapb, LAPB_DM, frame->pf,
265 LAPB_RESPONSE);
266 } else {
267 lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
268 lapb->dev, frame->pf);
269 lapb_send_control(lapb, LAPB_UA, frame->pf,
270 LAPB_RESPONSE);
271 lapb_stop_t1timer(lapb);
272 lapb_stop_t2timer(lapb);
273 lapb->condition = 0x00;
274 lapb->n2count = 0;
275 lapb->vs = 0;
276 lapb->vr = 0;
277 lapb->va = 0;
278 lapb_requeue_frames(lapb);
279 }
280 break;
281
282 case LAPB_SABME:
283 lapb_dbg(1, "(%p) S3 RX SABME(%d)\n", lapb->dev, frame->pf);
284 if (lapb->mode & LAPB_EXTENDED) {
285 lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
286 lapb->dev, frame->pf);
287 lapb_send_control(lapb, LAPB_UA, frame->pf,
288 LAPB_RESPONSE);
289 lapb_stop_t1timer(lapb);
290 lapb_stop_t2timer(lapb);
291 lapb->condition = 0x00;
292 lapb->n2count = 0;
293 lapb->vs = 0;
294 lapb->vr = 0;
295 lapb->va = 0;
296 lapb_requeue_frames(lapb);
297 } else {
298 lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
299 lapb->dev, frame->pf);
300 lapb_send_control(lapb, LAPB_DM, frame->pf,
301 LAPB_RESPONSE);
302 }
303 break;
304
305 case LAPB_DISC:
306 lapb_dbg(1, "(%p) S3 RX DISC(%d)\n", lapb->dev, frame->pf);
307 lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
308 lapb_clear_queues(lapb);
309 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
310 lapb_start_t1timer(lapb);
311 lapb_stop_t2timer(lapb);
312 lapb->state = LAPB_STATE_0;
313 lapb_disconnect_indication(lapb, LAPB_OK);
314 break;
315
316 case LAPB_DM:
317 lapb_dbg(1, "(%p) S3 RX DM(%d)\n", lapb->dev, frame->pf);
318 lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
319 lapb_clear_queues(lapb);
320 lapb->state = LAPB_STATE_0;
321 lapb_start_t1timer(lapb);
322 lapb_stop_t2timer(lapb);
323 lapb_disconnect_indication(lapb, LAPB_NOTCONNECTED);
324 break;
325
326 case LAPB_RNR:
327 lapb_dbg(1, "(%p) S3 RX RNR(%d) R%d\n",
328 lapb->dev, frame->pf, frame->nr);
329 lapb->condition |= LAPB_PEER_RX_BUSY_CONDITION;
330 lapb_check_need_response(lapb, frame->cr, frame->pf);
331 if (lapb_validate_nr(lapb, frame->nr)) {
332 lapb_check_iframes_acked(lapb, frame->nr);
333 } else {
334 lapb->frmr_data = *frame;
335 lapb->frmr_type = LAPB_FRMR_Z;
336 lapb_transmit_frmr(lapb);
337 lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
338 lapb_start_t1timer(lapb);
339 lapb_stop_t2timer(lapb);
340 lapb->state = LAPB_STATE_4;
341 lapb->n2count = 0;
342 }
343 break;
344
345 case LAPB_RR:
346 lapb_dbg(1, "(%p) S3 RX RR(%d) R%d\n",
347 lapb->dev, frame->pf, frame->nr);
348 lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
349 lapb_check_need_response(lapb, frame->cr, frame->pf);
350 if (lapb_validate_nr(lapb, frame->nr)) {
351 lapb_check_iframes_acked(lapb, frame->nr);
352 } else {
353 lapb->frmr_data = *frame;
354 lapb->frmr_type = LAPB_FRMR_Z;
355 lapb_transmit_frmr(lapb);
356 lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
357 lapb_start_t1timer(lapb);
358 lapb_stop_t2timer(lapb);
359 lapb->state = LAPB_STATE_4;
360 lapb->n2count = 0;
361 }
362 break;
363
364 case LAPB_REJ:
365 lapb_dbg(1, "(%p) S3 RX REJ(%d) R%d\n",
366 lapb->dev, frame->pf, frame->nr);
367 lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
368 lapb_check_need_response(lapb, frame->cr, frame->pf);
369 if (lapb_validate_nr(lapb, frame->nr)) {
370 lapb_frames_acked(lapb, frame->nr);
371 lapb_stop_t1timer(lapb);
372 lapb->n2count = 0;
373 lapb_requeue_frames(lapb);
374 } else {
375 lapb->frmr_data = *frame;
376 lapb->frmr_type = LAPB_FRMR_Z;
377 lapb_transmit_frmr(lapb);
378 lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
379 lapb_start_t1timer(lapb);
380 lapb_stop_t2timer(lapb);
381 lapb->state = LAPB_STATE_4;
382 lapb->n2count = 0;
383 }
384 break;
385
386 case LAPB_I:
387 lapb_dbg(1, "(%p) S3 RX I(%d) S%d R%d\n",
388 lapb->dev, frame->pf, frame->ns, frame->nr);
389 if (!lapb_validate_nr(lapb, frame->nr)) {
390 lapb->frmr_data = *frame;
391 lapb->frmr_type = LAPB_FRMR_Z;
392 lapb_transmit_frmr(lapb);
393 lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
394 lapb_start_t1timer(lapb);
395 lapb_stop_t2timer(lapb);
396 lapb->state = LAPB_STATE_4;
397 lapb->n2count = 0;
398 break;
399 }
400 if (lapb->condition & LAPB_PEER_RX_BUSY_CONDITION)
401 lapb_frames_acked(lapb, frame->nr);
402 else
403 lapb_check_iframes_acked(lapb, frame->nr);
404
405 if (frame->ns == lapb->vr) {
406 int cn;
407 cn = lapb_data_indication(lapb, skb);
408 queued = 1;
409 /*
410 * If upper layer has dropped the frame, we
411 * basically ignore any further protocol
412 * processing. This will cause the peer
413 * to re-transmit the frame later like
414 * a frame lost on the wire.
415 */
416 if (cn == NET_RX_DROP) {
417 pr_debug("rx congestion\n");
418 break;
419 }
420 lapb->vr = (lapb->vr + 1) % modulus;
421 lapb->condition &= ~LAPB_REJECT_CONDITION;
422 if (frame->pf)
423 lapb_enquiry_response(lapb);
424 else {
425 if (!(lapb->condition &
426 LAPB_ACK_PENDING_CONDITION)) {
427 lapb->condition |= LAPB_ACK_PENDING_CONDITION;
428 lapb_start_t2timer(lapb);
429 }
430 }
431 } else {
432 if (lapb->condition & LAPB_REJECT_CONDITION) {
433 if (frame->pf)
434 lapb_enquiry_response(lapb);
435 } else {
436 lapb_dbg(1, "(%p) S3 TX REJ(%d) R%d\n",
437 lapb->dev, frame->pf, lapb->vr);
438 lapb->condition |= LAPB_REJECT_CONDITION;
439 lapb_send_control(lapb, LAPB_REJ, frame->pf,
440 LAPB_RESPONSE);
441 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
442 }
443 }
444 break;
445
446 case LAPB_FRMR:
447 lapb_dbg(1, "(%p) S3 RX FRMR(%d) %02X %02X %02X %02X %02X\n",
448 lapb->dev, frame->pf,
449 skb->data[0], skb->data[1], skb->data[2],
450 skb->data[3], skb->data[4]);
451 lapb_establish_data_link(lapb);
452 lapb_dbg(0, "(%p) S3 -> S1\n", lapb->dev);
453 lapb_requeue_frames(lapb);
454 lapb->state = LAPB_STATE_1;
455 break;
456
457 case LAPB_ILLEGAL:
458 lapb_dbg(1, "(%p) S3 RX ILLEGAL(%d)\n", lapb->dev, frame->pf);
459 lapb->frmr_data = *frame;
460 lapb->frmr_type = LAPB_FRMR_W;
461 lapb_transmit_frmr(lapb);
462 lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
463 lapb_start_t1timer(lapb);
464 lapb_stop_t2timer(lapb);
465 lapb->state = LAPB_STATE_4;
466 lapb->n2count = 0;
467 break;
468 }
469
470 if (!queued)
471 kfree_skb(skb);
472}
473
474/*
475 * State machine for state 4, Frame Reject State.
476 * The handling of the timer(s) is in file lapb_timer.c.
477 */
478static void lapb_state4_machine(struct lapb_cb *lapb, struct sk_buff *skb,
479 struct lapb_frame *frame)
480{
481 switch (frame->type) {
482 case LAPB_SABM:
483 lapb_dbg(1, "(%p) S4 RX SABM(%d)\n", lapb->dev, frame->pf);
484 if (lapb->mode & LAPB_EXTENDED) {
485 lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
486 lapb->dev, frame->pf);
487 lapb_send_control(lapb, LAPB_DM, frame->pf,
488 LAPB_RESPONSE);
489 } else {
490 lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
491 lapb->dev, frame->pf);
492 lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
493 lapb_send_control(lapb, LAPB_UA, frame->pf,
494 LAPB_RESPONSE);
495 lapb_stop_t1timer(lapb);
496 lapb_stop_t2timer(lapb);
497 lapb->state = LAPB_STATE_3;
498 lapb->condition = 0x00;
499 lapb->n2count = 0;
500 lapb->vs = 0;
501 lapb->vr = 0;
502 lapb->va = 0;
503 lapb_connect_indication(lapb, LAPB_OK);
504 }
505 break;
506
507 case LAPB_SABME:
508 lapb_dbg(1, "(%p) S4 RX SABME(%d)\n", lapb->dev, frame->pf);
509 if (lapb->mode & LAPB_EXTENDED) {
510 lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
511 lapb->dev, frame->pf);
512 lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
513 lapb_send_control(lapb, LAPB_UA, frame->pf,
514 LAPB_RESPONSE);
515 lapb_stop_t1timer(lapb);
516 lapb_stop_t2timer(lapb);
517 lapb->state = LAPB_STATE_3;
518 lapb->condition = 0x00;
519 lapb->n2count = 0;
520 lapb->vs = 0;
521 lapb->vr = 0;
522 lapb->va = 0;
523 lapb_connect_indication(lapb, LAPB_OK);
524 } else {
525 lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
526 lapb->dev, frame->pf);
527 lapb_send_control(lapb, LAPB_DM, frame->pf,
528 LAPB_RESPONSE);
529 }
530 break;
531 }
532
533 kfree_skb(skb);
534}
535
536/*
537 * Process an incoming LAPB frame
538 */
539void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *skb)
540{
541 struct lapb_frame frame;
542
543 if (lapb_decode(lapb, skb, &frame) < 0) {
544 kfree_skb(skb);
545 return;
546 }
547
548 switch (lapb->state) {
549 case LAPB_STATE_0:
550 lapb_state0_machine(lapb, skb, &frame); break;
551 case LAPB_STATE_1:
552 lapb_state1_machine(lapb, skb, &frame); break;
553 case LAPB_STATE_2:
554 lapb_state2_machine(lapb, skb, &frame); break;
555 case LAPB_STATE_3:
556 lapb_state3_machine(lapb, skb, &frame); break;
557 case LAPB_STATE_4:
558 lapb_state4_machine(lapb, skb, &frame); break;
559 }
560
561 lapb_kick(lapb);
562}