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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
42
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
113
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
189
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
249
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
411
412
413
414
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
476
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
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}
563
