4 * This code REQUIRES 2.1.15 or higher/ NET3.038
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.
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.
18 #include <linux/errno.h>
19 #include <linux/types.h>
20 #include <linux/socket.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>
32 #include <asm/uaccess.h>
33 #include <linux/fcntl.h>
35 #include <linux/interrupt.h>
39 * State machine for state 0, Disconnected State.
40 * The handling of the timer(s) is in file lapb_timer.c.
42 static void lapb_state0_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
43 struct lapb_frame
*frame
)
45 switch (frame
->type
) {
48 printk(KERN_DEBUG
"lapb: (%p) S0 RX SABM(%d)\n",
49 lapb
->dev
, frame
->pf
);
51 if (lapb
->mode
& LAPB_EXTENDED
) {
53 printk(KERN_DEBUG
"lapb: (%p) S0 TX DM(%d)\n",
54 lapb
->dev
, frame
->pf
);
56 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
60 printk(KERN_DEBUG
"lapb: (%p) S0 TX UA(%d)\n",
61 lapb
->dev
, frame
->pf
);
64 printk(KERN_DEBUG
"lapb: (%p) S0 -> S3\n", lapb
->dev
);
66 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
68 lapb_stop_t1timer(lapb
);
69 lapb_stop_t2timer(lapb
);
70 lapb
->state
= LAPB_STATE_3
;
71 lapb
->condition
= 0x00;
76 lapb_connect_indication(lapb
, LAPB_OK
);
82 printk(KERN_DEBUG
"lapb: (%p) S0 RX SABME(%d)\n",
83 lapb
->dev
, frame
->pf
);
85 if (lapb
->mode
& LAPB_EXTENDED
) {
87 printk(KERN_DEBUG
"lapb: (%p) S0 TX UA(%d)\n",
88 lapb
->dev
, frame
->pf
);
91 printk(KERN_DEBUG
"lapb: (%p) S0 -> S3\n", lapb
->dev
);
93 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
95 lapb_stop_t1timer(lapb
);
96 lapb_stop_t2timer(lapb
);
97 lapb
->state
= LAPB_STATE_3
;
98 lapb
->condition
= 0x00;
103 lapb_connect_indication(lapb
, LAPB_OK
);
106 printk(KERN_DEBUG
"lapb: (%p) S0 TX DM(%d)\n",
107 lapb
->dev
, frame
->pf
);
109 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
116 printk(KERN_DEBUG
"lapb: (%p) S0 RX DISC(%d)\n",
117 lapb
->dev
, frame
->pf
);
118 printk(KERN_DEBUG
"lapb: (%p) S0 TX UA(%d)\n",
119 lapb
->dev
, frame
->pf
);
121 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
, LAPB_RESPONSE
);
132 * State machine for state 1, Awaiting Connection State.
133 * The handling of the timer(s) is in file lapb_timer.c.
135 static void lapb_state1_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
136 struct lapb_frame
*frame
)
138 switch (frame
->type
) {
141 printk(KERN_DEBUG
"lapb: (%p) S1 RX SABM(%d)\n",
142 lapb
->dev
, frame
->pf
);
144 if (lapb
->mode
& LAPB_EXTENDED
) {
146 printk(KERN_DEBUG
"lapb: (%p) S1 TX DM(%d)\n",
147 lapb
->dev
, frame
->pf
);
149 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
153 printk(KERN_DEBUG
"lapb: (%p) S1 TX UA(%d)\n",
154 lapb
->dev
, frame
->pf
);
156 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
163 printk(KERN_DEBUG
"lapb: (%p) S1 RX SABME(%d)\n",
164 lapb
->dev
, frame
->pf
);
166 if (lapb
->mode
& LAPB_EXTENDED
) {
168 printk(KERN_DEBUG
"lapb: (%p) S1 TX UA(%d)\n",
169 lapb
->dev
, frame
->pf
);
171 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
175 printk(KERN_DEBUG
"lapb: (%p) S1 TX DM(%d)\n",
176 lapb
->dev
, frame
->pf
);
178 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
185 printk(KERN_DEBUG
"lapb: (%p) S1 RX DISC(%d)\n",
186 lapb
->dev
, frame
->pf
);
187 printk(KERN_DEBUG
"lapb: (%p) S1 TX DM(%d)\n",
188 lapb
->dev
, frame
->pf
);
190 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
, LAPB_RESPONSE
);
195 printk(KERN_DEBUG
"lapb: (%p) S1 RX UA(%d)\n",
196 lapb
->dev
, frame
->pf
);
200 printk(KERN_DEBUG
"lapb: (%p) S1 -> S3\n", lapb
->dev
);
202 lapb_stop_t1timer(lapb
);
203 lapb_stop_t2timer(lapb
);
204 lapb
->state
= LAPB_STATE_3
;
205 lapb
->condition
= 0x00;
210 lapb_connect_confirmation(lapb
, LAPB_OK
);
216 printk(KERN_DEBUG
"lapb: (%p) S1 RX DM(%d)\n",
217 lapb
->dev
, frame
->pf
);
221 printk(KERN_DEBUG
"lapb: (%p) S1 -> S0\n", lapb
->dev
);
223 lapb_clear_queues(lapb
);
224 lapb
->state
= LAPB_STATE_0
;
225 lapb_start_t1timer(lapb
);
226 lapb_stop_t2timer(lapb
);
227 lapb_disconnect_indication(lapb
, LAPB_REFUSED
);
236 * State machine for state 2, Awaiting Release State.
237 * The handling of the timer(s) is in file lapb_timer.c
239 static void lapb_state2_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
240 struct lapb_frame
*frame
)
242 switch (frame
->type
) {
246 printk(KERN_DEBUG
"lapb: (%p) S2 RX {SABM,SABME}(%d)\n",
247 lapb
->dev
, frame
->pf
);
248 printk(KERN_DEBUG
"lapb: (%p) S2 TX DM(%d)\n",
249 lapb
->dev
, frame
->pf
);
251 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
, LAPB_RESPONSE
);
256 printk(KERN_DEBUG
"lapb: (%p) S2 RX DISC(%d)\n",
257 lapb
->dev
, frame
->pf
);
258 printk(KERN_DEBUG
"lapb: (%p) S2 TX UA(%d)\n",
259 lapb
->dev
, frame
->pf
);
261 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
, LAPB_RESPONSE
);
266 printk(KERN_DEBUG
"lapb: (%p) S2 RX UA(%d)\n",
267 lapb
->dev
, frame
->pf
);
271 printk(KERN_DEBUG
"lapb: (%p) S2 -> S0\n", lapb
->dev
);
273 lapb
->state
= LAPB_STATE_0
;
274 lapb_start_t1timer(lapb
);
275 lapb_stop_t2timer(lapb
);
276 lapb_disconnect_confirmation(lapb
, LAPB_OK
);
282 printk(KERN_DEBUG
"lapb: (%p) S2 RX DM(%d)\n",
283 lapb
->dev
, frame
->pf
);
287 printk(KERN_DEBUG
"lapb: (%p) S2 -> S0\n", lapb
->dev
);
289 lapb
->state
= LAPB_STATE_0
;
290 lapb_start_t1timer(lapb
);
291 lapb_stop_t2timer(lapb
);
292 lapb_disconnect_confirmation(lapb
, LAPB_NOTCONNECTED
);
301 printk(KERN_DEBUG
"lapb: (%p) S2 RX {I,REJ,RNR,RR}(%d)\n",
302 lapb
->dev
, frame
->pf
);
303 printk(KERN_DEBUG
"lapb: (%p) S2 RX DM(%d)\n",
304 lapb
->dev
, frame
->pf
);
307 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
316 * State machine for state 3, Connected State.
317 * The handling of the timer(s) is in file lapb_timer.c
319 static void lapb_state3_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
320 struct lapb_frame
*frame
)
323 int modulus
= (lapb
->mode
& LAPB_EXTENDED
) ? LAPB_EMODULUS
:
326 switch (frame
->type
) {
329 printk(KERN_DEBUG
"lapb: (%p) S3 RX SABM(%d)\n",
330 lapb
->dev
, frame
->pf
);
332 if (lapb
->mode
& LAPB_EXTENDED
) {
334 printk(KERN_DEBUG
"lapb: (%p) S3 TX DM(%d)\n",
335 lapb
->dev
, frame
->pf
);
337 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
341 printk(KERN_DEBUG
"lapb: (%p) S3 TX UA(%d)\n",
342 lapb
->dev
, frame
->pf
);
344 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
346 lapb_stop_t1timer(lapb
);
347 lapb_stop_t2timer(lapb
);
348 lapb
->condition
= 0x00;
353 lapb_requeue_frames(lapb
);
359 printk(KERN_DEBUG
"lapb: (%p) S3 RX SABME(%d)\n",
360 lapb
->dev
, frame
->pf
);
362 if (lapb
->mode
& LAPB_EXTENDED
) {
364 printk(KERN_DEBUG
"lapb: (%p) S3 TX UA(%d)\n",
365 lapb
->dev
, frame
->pf
);
367 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
369 lapb_stop_t1timer(lapb
);
370 lapb_stop_t2timer(lapb
);
371 lapb
->condition
= 0x00;
376 lapb_requeue_frames(lapb
);
379 printk(KERN_DEBUG
"lapb: (%p) S3 TX DM(%d)\n",
380 lapb
->dev
, frame
->pf
);
382 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
389 printk(KERN_DEBUG
"lapb: (%p) S3 RX DISC(%d)\n",
390 lapb
->dev
, frame
->pf
);
393 printk(KERN_DEBUG
"lapb: (%p) S3 -> S0\n", lapb
->dev
);
395 lapb_clear_queues(lapb
);
396 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
, LAPB_RESPONSE
);
397 lapb_start_t1timer(lapb
);
398 lapb_stop_t2timer(lapb
);
399 lapb
->state
= LAPB_STATE_0
;
400 lapb_disconnect_indication(lapb
, LAPB_OK
);
405 printk(KERN_DEBUG
"lapb: (%p) S3 RX DM(%d)\n",
406 lapb
->dev
, frame
->pf
);
409 printk(KERN_DEBUG
"lapb: (%p) S3 -> S0\n", lapb
->dev
);
411 lapb_clear_queues(lapb
);
412 lapb
->state
= LAPB_STATE_0
;
413 lapb_start_t1timer(lapb
);
414 lapb_stop_t2timer(lapb
);
415 lapb_disconnect_indication(lapb
, LAPB_NOTCONNECTED
);
420 printk(KERN_DEBUG
"lapb: (%p) S3 RX RNR(%d) R%d\n",
421 lapb
->dev
, frame
->pf
, frame
->nr
);
423 lapb
->condition
|= LAPB_PEER_RX_BUSY_CONDITION
;
424 lapb_check_need_response(lapb
, frame
->cr
, frame
->pf
);
425 if (lapb_validate_nr(lapb
, frame
->nr
)) {
426 lapb_check_iframes_acked(lapb
, frame
->nr
);
428 lapb
->frmr_data
= *frame
;
429 lapb
->frmr_type
= LAPB_FRMR_Z
;
430 lapb_transmit_frmr(lapb
);
432 printk(KERN_DEBUG
"lapb: (%p) S3 -> S4\n", lapb
->dev
);
434 lapb_start_t1timer(lapb
);
435 lapb_stop_t2timer(lapb
);
436 lapb
->state
= LAPB_STATE_4
;
443 printk(KERN_DEBUG
"lapb: (%p) S3 RX RR(%d) R%d\n",
444 lapb
->dev
, frame
->pf
, frame
->nr
);
446 lapb
->condition
&= ~LAPB_PEER_RX_BUSY_CONDITION
;
447 lapb_check_need_response(lapb
, frame
->cr
, frame
->pf
);
448 if (lapb_validate_nr(lapb
, frame
->nr
)) {
449 lapb_check_iframes_acked(lapb
, frame
->nr
);
451 lapb
->frmr_data
= *frame
;
452 lapb
->frmr_type
= LAPB_FRMR_Z
;
453 lapb_transmit_frmr(lapb
);
455 printk(KERN_DEBUG
"lapb: (%p) S3 -> S4\n", lapb
->dev
);
457 lapb_start_t1timer(lapb
);
458 lapb_stop_t2timer(lapb
);
459 lapb
->state
= LAPB_STATE_4
;
466 printk(KERN_DEBUG
"lapb: (%p) S3 RX REJ(%d) R%d\n",
467 lapb
->dev
, frame
->pf
, frame
->nr
);
469 lapb
->condition
&= ~LAPB_PEER_RX_BUSY_CONDITION
;
470 lapb_check_need_response(lapb
, frame
->cr
, frame
->pf
);
471 if (lapb_validate_nr(lapb
, frame
->nr
)) {
472 lapb_frames_acked(lapb
, frame
->nr
);
473 lapb_stop_t1timer(lapb
);
475 lapb_requeue_frames(lapb
);
477 lapb
->frmr_data
= *frame
;
478 lapb
->frmr_type
= LAPB_FRMR_Z
;
479 lapb_transmit_frmr(lapb
);
481 printk(KERN_DEBUG
"lapb: (%p) S3 -> S4\n", lapb
->dev
);
483 lapb_start_t1timer(lapb
);
484 lapb_stop_t2timer(lapb
);
485 lapb
->state
= LAPB_STATE_4
;
492 printk(KERN_DEBUG
"lapb: (%p) S3 RX I(%d) S%d R%d\n",
493 lapb
->dev
, frame
->pf
, frame
->ns
, frame
->nr
);
495 if (!lapb_validate_nr(lapb
, frame
->nr
)) {
496 lapb
->frmr_data
= *frame
;
497 lapb
->frmr_type
= LAPB_FRMR_Z
;
498 lapb_transmit_frmr(lapb
);
500 printk(KERN_DEBUG
"lapb: (%p) S3 -> S4\n", lapb
->dev
);
502 lapb_start_t1timer(lapb
);
503 lapb_stop_t2timer(lapb
);
504 lapb
->state
= LAPB_STATE_4
;
508 if (lapb
->condition
& LAPB_PEER_RX_BUSY_CONDITION
)
509 lapb_frames_acked(lapb
, frame
->nr
);
511 lapb_check_iframes_acked(lapb
, frame
->nr
);
513 if (frame
->ns
== lapb
->vr
) {
515 cn
= lapb_data_indication(lapb
, skb
);
518 * If upper layer has dropped the frame, we
519 * basically ignore any further protocol
520 * processing. This will cause the peer
521 * to re-transmit the frame later like
522 * a frame lost on the wire.
524 if (cn
== NET_RX_DROP
) {
525 printk(KERN_DEBUG
"LAPB: rx congestion\n");
528 lapb
->vr
= (lapb
->vr
+ 1) % modulus
;
529 lapb
->condition
&= ~LAPB_REJECT_CONDITION
;
531 lapb_enquiry_response(lapb
);
533 if (!(lapb
->condition
&
534 LAPB_ACK_PENDING_CONDITION
)) {
535 lapb
->condition
|= LAPB_ACK_PENDING_CONDITION
;
536 lapb_start_t2timer(lapb
);
540 if (lapb
->condition
& LAPB_REJECT_CONDITION
) {
542 lapb_enquiry_response(lapb
);
546 "lapb: (%p) S3 TX REJ(%d) R%d\n",
547 lapb
->dev
, frame
->pf
, lapb
->vr
);
549 lapb
->condition
|= LAPB_REJECT_CONDITION
;
550 lapb_send_control(lapb
, LAPB_REJ
, frame
->pf
,
552 lapb
->condition
&= ~LAPB_ACK_PENDING_CONDITION
;
559 printk(KERN_DEBUG
"lapb: (%p) S3 RX FRMR(%d) %02X "
560 "%02X %02X %02X %02X\n", lapb
->dev
, frame
->pf
,
561 skb
->data
[0], skb
->data
[1], skb
->data
[2],
562 skb
->data
[3], skb
->data
[4]);
564 lapb_establish_data_link(lapb
);
566 printk(KERN_DEBUG
"lapb: (%p) S3 -> S1\n", lapb
->dev
);
568 lapb_requeue_frames(lapb
);
569 lapb
->state
= LAPB_STATE_1
;
574 printk(KERN_DEBUG
"lapb: (%p) S3 RX ILLEGAL(%d)\n",
575 lapb
->dev
, frame
->pf
);
577 lapb
->frmr_data
= *frame
;
578 lapb
->frmr_type
= LAPB_FRMR_W
;
579 lapb_transmit_frmr(lapb
);
581 printk(KERN_DEBUG
"lapb: (%p) S3 -> S4\n", lapb
->dev
);
583 lapb_start_t1timer(lapb
);
584 lapb_stop_t2timer(lapb
);
585 lapb
->state
= LAPB_STATE_4
;
595 * State machine for state 4, Frame Reject State.
596 * The handling of the timer(s) is in file lapb_timer.c.
598 static void lapb_state4_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
599 struct lapb_frame
*frame
)
601 switch (frame
->type
) {
604 printk(KERN_DEBUG
"lapb: (%p) S4 RX SABM(%d)\n",
605 lapb
->dev
, frame
->pf
);
607 if (lapb
->mode
& LAPB_EXTENDED
) {
609 printk(KERN_DEBUG
"lapb: (%p) S4 TX DM(%d)\n",
610 lapb
->dev
, frame
->pf
);
612 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
616 printk(KERN_DEBUG
"lapb: (%p) S4 TX UA(%d)\n",
617 lapb
->dev
, frame
->pf
);
620 printk(KERN_DEBUG
"lapb: (%p) S4 -> S3\n", lapb
->dev
);
622 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
624 lapb_stop_t1timer(lapb
);
625 lapb_stop_t2timer(lapb
);
626 lapb
->state
= LAPB_STATE_3
;
627 lapb
->condition
= 0x00;
632 lapb_connect_indication(lapb
, LAPB_OK
);
638 printk(KERN_DEBUG
"lapb: (%p) S4 RX SABME(%d)\n",
639 lapb
->dev
, frame
->pf
);
641 if (lapb
->mode
& LAPB_EXTENDED
) {
643 printk(KERN_DEBUG
"lapb: (%p) S4 TX UA(%d)\n",
644 lapb
->dev
, frame
->pf
);
647 printk(KERN_DEBUG
"lapb: (%p) S4 -> S3\n", lapb
->dev
);
649 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
651 lapb_stop_t1timer(lapb
);
652 lapb_stop_t2timer(lapb
);
653 lapb
->state
= LAPB_STATE_3
;
654 lapb
->condition
= 0x00;
659 lapb_connect_indication(lapb
, LAPB_OK
);
662 printk(KERN_DEBUG
"lapb: (%p) S4 TX DM(%d)\n",
663 lapb
->dev
, frame
->pf
);
665 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
675 * Process an incoming LAPB frame
677 void lapb_data_input(struct lapb_cb
*lapb
, struct sk_buff
*skb
)
679 struct lapb_frame frame
;
681 if (lapb_decode(lapb
, skb
, &frame
) < 0) {
686 switch (lapb
->state
) {
688 lapb_state0_machine(lapb
, skb
, &frame
); break;
690 lapb_state1_machine(lapb
, skb
, &frame
); break;
692 lapb_state2_machine(lapb
, skb
, &frame
); break;
694 lapb_state3_machine(lapb
, skb
, &frame
); break;
696 lapb_state4_machine(lapb
, skb
, &frame
); break;