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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20 #include <linux/errno.h>
21 #include <linux/types.h>
22 #include <linux/socket.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>
34 #include <asm/uaccess.h>
35 #include <linux/fcntl.h>
37 #include <linux/interrupt.h>
41 * State machine for state 0, Disconnected State.
42 * The handling of the timer(s) is in file lapb_timer.c.
44 static void lapb_state0_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
45 struct lapb_frame
*frame
)
47 switch (frame
->type
) {
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
,
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
,
61 lapb_stop_t1timer(lapb
);
62 lapb_stop_t2timer(lapb
);
63 lapb
->state
= LAPB_STATE_3
;
64 lapb
->condition
= 0x00;
69 lapb_connect_indication(lapb
, LAPB_OK
);
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
,
81 lapb_stop_t1timer(lapb
);
82 lapb_stop_t2timer(lapb
);
83 lapb
->state
= LAPB_STATE_3
;
84 lapb
->condition
= 0x00;
89 lapb_connect_indication(lapb
, LAPB_OK
);
91 lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
92 lapb
->dev
, frame
->pf
);
93 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
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
);
112 * State machine for state 1, Awaiting Connection State.
113 * The handling of the timer(s) is in file lapb_timer.c.
115 static void lapb_state1_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
116 struct lapb_frame
*frame
)
118 switch (frame
->type
) {
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
,
127 lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
128 lapb
->dev
, frame
->pf
);
129 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
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
,
142 lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
143 lapb
->dev
, frame
->pf
);
144 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
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
);
156 lapb_dbg(1, "(%p) S1 RX UA(%d)\n", lapb
->dev
, 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;
167 lapb_connect_confirmation(lapb
, LAPB_OK
);
172 lapb_dbg(1, "(%p) S1 RX DM(%d)\n", lapb
->dev
, 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
);
188 * State machine for state 2, Awaiting Release State.
189 * The handling of the timer(s) is in file lapb_timer.c
191 static void lapb_state2_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
192 struct lapb_frame
*frame
)
194 switch (frame
->type
) {
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
);
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
);
210 lapb_dbg(1, "(%p) S2 RX UA(%d)\n", lapb
->dev
, 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
);
221 lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb
->dev
, 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
);
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
);
239 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
248 * State machine for state 3, Connected State.
249 * The handling of the timer(s) is in file lapb_timer.c
251 static void lapb_state3_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
252 struct lapb_frame
*frame
)
255 int modulus
= (lapb
->mode
& LAPB_EXTENDED
) ? LAPB_EMODULUS
:
258 switch (frame
->type
) {
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
,
267 lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
268 lapb
->dev
, frame
->pf
);
269 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
271 lapb_stop_t1timer(lapb
);
272 lapb_stop_t2timer(lapb
);
273 lapb
->condition
= 0x00;
278 lapb_requeue_frames(lapb
);
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
,
289 lapb_stop_t1timer(lapb
);
290 lapb_stop_t2timer(lapb
);
291 lapb
->condition
= 0x00;
296 lapb_requeue_frames(lapb
);
298 lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
299 lapb
->dev
, frame
->pf
);
300 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
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
);
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
);
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
);
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
;
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
);
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
;
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
);
373 lapb_requeue_frames(lapb
);
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
;
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
;
400 if (lapb
->condition
& LAPB_PEER_RX_BUSY_CONDITION
)
401 lapb_frames_acked(lapb
, frame
->nr
);
403 lapb_check_iframes_acked(lapb
, frame
->nr
);
405 if (frame
->ns
== lapb
->vr
) {
407 cn
= lapb_data_indication(lapb
, skb
);
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.
416 if (cn
== NET_RX_DROP
) {
417 pr_debug("rx congestion\n");
420 lapb
->vr
= (lapb
->vr
+ 1) % modulus
;
421 lapb
->condition
&= ~LAPB_REJECT_CONDITION
;
423 lapb_enquiry_response(lapb
);
425 if (!(lapb
->condition
&
426 LAPB_ACK_PENDING_CONDITION
)) {
427 lapb
->condition
|= LAPB_ACK_PENDING_CONDITION
;
428 lapb_start_t2timer(lapb
);
432 if (lapb
->condition
& LAPB_REJECT_CONDITION
) {
434 lapb_enquiry_response(lapb
);
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
,
441 lapb
->condition
&= ~LAPB_ACK_PENDING_CONDITION
;
447 lapb_dbg(1, "(%p) S3 RX FRMR(%d) %5ph\n",
448 lapb
->dev
, frame
->pf
,
450 lapb_establish_data_link(lapb
);
451 lapb_dbg(0, "(%p) S3 -> S1\n", lapb
->dev
);
452 lapb_requeue_frames(lapb
);
453 lapb
->state
= LAPB_STATE_1
;
457 lapb_dbg(1, "(%p) S3 RX ILLEGAL(%d)\n", lapb
->dev
, frame
->pf
);
458 lapb
->frmr_data
= *frame
;
459 lapb
->frmr_type
= LAPB_FRMR_W
;
460 lapb_transmit_frmr(lapb
);
461 lapb_dbg(0, "(%p) S3 -> S4\n", lapb
->dev
);
462 lapb_start_t1timer(lapb
);
463 lapb_stop_t2timer(lapb
);
464 lapb
->state
= LAPB_STATE_4
;
474 * State machine for state 4, Frame Reject State.
475 * The handling of the timer(s) is in file lapb_timer.c.
477 static void lapb_state4_machine(struct lapb_cb
*lapb
, struct sk_buff
*skb
,
478 struct lapb_frame
*frame
)
480 switch (frame
->type
) {
482 lapb_dbg(1, "(%p) S4 RX SABM(%d)\n", lapb
->dev
, frame
->pf
);
483 if (lapb
->mode
& LAPB_EXTENDED
) {
484 lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
485 lapb
->dev
, frame
->pf
);
486 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
489 lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
490 lapb
->dev
, frame
->pf
);
491 lapb_dbg(0, "(%p) S4 -> S3\n", lapb
->dev
);
492 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
494 lapb_stop_t1timer(lapb
);
495 lapb_stop_t2timer(lapb
);
496 lapb
->state
= LAPB_STATE_3
;
497 lapb
->condition
= 0x00;
502 lapb_connect_indication(lapb
, LAPB_OK
);
507 lapb_dbg(1, "(%p) S4 RX SABME(%d)\n", lapb
->dev
, frame
->pf
);
508 if (lapb
->mode
& LAPB_EXTENDED
) {
509 lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
510 lapb
->dev
, frame
->pf
);
511 lapb_dbg(0, "(%p) S4 -> S3\n", lapb
->dev
);
512 lapb_send_control(lapb
, LAPB_UA
, frame
->pf
,
514 lapb_stop_t1timer(lapb
);
515 lapb_stop_t2timer(lapb
);
516 lapb
->state
= LAPB_STATE_3
;
517 lapb
->condition
= 0x00;
522 lapb_connect_indication(lapb
, LAPB_OK
);
524 lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
525 lapb
->dev
, frame
->pf
);
526 lapb_send_control(lapb
, LAPB_DM
, frame
->pf
,
536 * Process an incoming LAPB frame
538 void lapb_data_input(struct lapb_cb
*lapb
, struct sk_buff
*skb
)
540 struct lapb_frame frame
;
542 if (lapb_decode(lapb
, skb
, &frame
) < 0) {
547 switch (lapb
->state
) {
549 lapb_state0_machine(lapb
, skb
, &frame
); break;
551 lapb_state1_machine(lapb
, skb
, &frame
); break;
553 lapb_state2_machine(lapb
, skb
, &frame
); break;
555 lapb_state3_machine(lapb
, skb
, &frame
); break;
557 lapb_state4_machine(lapb
, skb
, &frame
); break;