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 <asm/system.h>
34 #include <linux/fcntl.h>
36 #include <linux/interrupt.h>
40 * State machine for state 0, Disconnected State.
41 * The handling of the timer(s) is in file lapb_timer.c.
43 static void lapb_state0_machine(struct lapb_cb *lapb, struct sk_buff *skb,
44 struct lapb_frame *frame)
46 switch (frame->type) {
49 printk(KERN_DEBUG "lapb: (%p) S0 RX SABM(%d)\n",
50 lapb->dev, frame->pf);
52 if (lapb->mode & LAPB_EXTENDED) {
54 printk(KERN_DEBUG "lapb: (%p) S0 TX DM(%d)\n",
55 lapb->dev, frame->pf);
57 lapb_send_control(lapb, LAPB_DM, frame->pf,
61 printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n",
62 lapb->dev, frame->pf);
65 printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n", lapb->dev);
67 lapb_send_control(lapb, LAPB_UA, frame->pf,
69 lapb_stop_t1timer(lapb);
70 lapb_stop_t2timer(lapb);
71 lapb->state = LAPB_STATE_3;
72 lapb->condition = 0x00;
77 lapb_connect_indication(lapb, LAPB_OK);
83 printk(KERN_DEBUG "lapb: (%p) S0 RX SABME(%d)\n",
84 lapb->dev, frame->pf);
86 if (lapb->mode & LAPB_EXTENDED) {
88 printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n",
89 lapb->dev, frame->pf);
92 printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n", lapb->dev);
94 lapb_send_control(lapb, LAPB_UA, frame->pf,
96 lapb_stop_t1timer(lapb);
97 lapb_stop_t2timer(lapb);
98 lapb->state = LAPB_STATE_3;
99 lapb->condition = 0x00;
104 lapb_connect_indication(lapb, LAPB_OK);
107 printk(KERN_DEBUG "lapb: (%p) S0 TX DM(%d)\n",
108 lapb->dev, frame->pf);
110 lapb_send_control(lapb, LAPB_DM, frame->pf,
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);
122 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
133 * State machine for state 1, Awaiting Connection State.
134 * The handling of the timer(s) is in file lapb_timer.c.
136 static void lapb_state1_machine(struct lapb_cb *lapb, struct sk_buff *skb,
137 struct lapb_frame *frame)
139 switch (frame->type) {
142 printk(KERN_DEBUG "lapb: (%p) S1 RX SABM(%d)\n",
143 lapb->dev, frame->pf);
145 if (lapb->mode & LAPB_EXTENDED) {
147 printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n",
148 lapb->dev, frame->pf);
150 lapb_send_control(lapb, LAPB_DM, frame->pf,
154 printk(KERN_DEBUG "lapb: (%p) S1 TX UA(%d)\n",
155 lapb->dev, frame->pf);
157 lapb_send_control(lapb, LAPB_UA, frame->pf,
164 printk(KERN_DEBUG "lapb: (%p) S1 RX SABME(%d)\n",
165 lapb->dev, frame->pf);
167 if (lapb->mode & LAPB_EXTENDED) {
169 printk(KERN_DEBUG "lapb: (%p) S1 TX UA(%d)\n",
170 lapb->dev, frame->pf);
172 lapb_send_control(lapb, LAPB_UA, frame->pf,
176 printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n",
177 lapb->dev, frame->pf);
179 lapb_send_control(lapb, LAPB_DM, frame->pf,
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);
191 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
196 printk(KERN_DEBUG "lapb: (%p) S1 RX UA(%d)\n",
197 lapb->dev, frame->pf);
201 printk(KERN_DEBUG "lapb: (%p) S1 -> S3\n", lapb->dev);
203 lapb_stop_t1timer(lapb);
204 lapb_stop_t2timer(lapb);
205 lapb->state = LAPB_STATE_3;
206 lapb->condition = 0x00;
211 lapb_connect_confirmation(lapb, LAPB_OK);
217 printk(KERN_DEBUG "lapb: (%p) S1 RX DM(%d)\n",
218 lapb->dev, frame->pf);
222 printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->dev);
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);
237 * State machine for state 2, Awaiting Release State.
238 * The handling of the timer(s) is in file lapb_timer.c
240 static void lapb_state2_machine(struct lapb_cb *lapb, struct sk_buff *skb,
241 struct lapb_frame *frame)
243 switch (frame->type) {
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);
252 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
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);
262 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
267 printk(KERN_DEBUG "lapb: (%p) S2 RX UA(%d)\n",
268 lapb->dev, frame->pf);
272 printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->dev);
274 lapb->state = LAPB_STATE_0;
275 lapb_start_t1timer(lapb);
276 lapb_stop_t2timer(lapb);
277 lapb_disconnect_confirmation(lapb, LAPB_OK);
283 printk(KERN_DEBUG "lapb: (%p) S2 RX DM(%d)\n",
284 lapb->dev, frame->pf);
288 printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->dev);
290 lapb->state = LAPB_STATE_0;
291 lapb_start_t1timer(lapb);
292 lapb_stop_t2timer(lapb);
293 lapb_disconnect_confirmation(lapb, LAPB_NOTCONNECTED);
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);
308 lapb_send_control(lapb, LAPB_DM, frame->pf,
317 * State machine for state 3, Connected State.
318 * The handling of the timer(s) is in file lapb_timer.c
320 static void lapb_state3_machine(struct lapb_cb *lapb, struct sk_buff *skb,
321 struct lapb_frame *frame)
324 int modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS :
327 switch (frame->type) {
330 printk(KERN_DEBUG "lapb: (%p) S3 RX SABM(%d)\n",
331 lapb->dev, frame->pf);
333 if (lapb->mode & LAPB_EXTENDED) {
335 printk(KERN_DEBUG "lapb: (%p) S3 TX DM(%d)\n",
336 lapb->dev, frame->pf);
338 lapb_send_control(lapb, LAPB_DM, frame->pf,
342 printk(KERN_DEBUG "lapb: (%p) S3 TX UA(%d)\n",
343 lapb->dev, frame->pf);
345 lapb_send_control(lapb, LAPB_UA, frame->pf,
347 lapb_stop_t1timer(lapb);
348 lapb_stop_t2timer(lapb);
349 lapb->condition = 0x00;
354 lapb_requeue_frames(lapb);
360 printk(KERN_DEBUG "lapb: (%p) S3 RX SABME(%d)\n",
361 lapb->dev, frame->pf);
363 if (lapb->mode & LAPB_EXTENDED) {
365 printk(KERN_DEBUG "lapb: (%p) S3 TX UA(%d)\n",
366 lapb->dev, frame->pf);
368 lapb_send_control(lapb, LAPB_UA, frame->pf,
370 lapb_stop_t1timer(lapb);
371 lapb_stop_t2timer(lapb);
372 lapb->condition = 0x00;
377 lapb_requeue_frames(lapb);
380 printk(KERN_DEBUG "lapb: (%p) S3 TX DM(%d)\n",
381 lapb->dev, frame->pf);
383 lapb_send_control(lapb, LAPB_DM, frame->pf,
390 printk(KERN_DEBUG "lapb: (%p) S3 RX DISC(%d)\n",
391 lapb->dev, frame->pf);
394 printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->dev);
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);
406 printk(KERN_DEBUG "lapb: (%p) S3 RX DM(%d)\n",
407 lapb->dev, frame->pf);
410 printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->dev);
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);
421 printk(KERN_DEBUG "lapb: (%p) S3 RX RNR(%d) R%d\n",
422 lapb->dev, frame->pf, frame->nr);
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);
429 lapb->frmr_data = *frame;
430 lapb->frmr_type = LAPB_FRMR_Z;
431 lapb_transmit_frmr(lapb);
433 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
435 lapb_start_t1timer(lapb);
436 lapb_stop_t2timer(lapb);
437 lapb->state = LAPB_STATE_4;
444 printk(KERN_DEBUG "lapb: (%p) S3 RX RR(%d) R%d\n",
445 lapb->dev, frame->pf, frame->nr);
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);
452 lapb->frmr_data = *frame;
453 lapb->frmr_type = LAPB_FRMR_Z;
454 lapb_transmit_frmr(lapb);
456 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
458 lapb_start_t1timer(lapb);
459 lapb_stop_t2timer(lapb);
460 lapb->state = LAPB_STATE_4;
467 printk(KERN_DEBUG "lapb: (%p) S3 RX REJ(%d) R%d\n",
468 lapb->dev, frame->pf, frame->nr);
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);
476 lapb_requeue_frames(lapb);
478 lapb->frmr_data = *frame;
479 lapb->frmr_type = LAPB_FRMR_Z;
480 lapb_transmit_frmr(lapb);
482 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
484 lapb_start_t1timer(lapb);
485 lapb_stop_t2timer(lapb);
486 lapb->state = LAPB_STATE_4;
493 printk(KERN_DEBUG "lapb: (%p) S3 RX I(%d) S%d R%d\n",
494 lapb->dev, frame->pf, frame->ns, frame->nr);
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);
501 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
503 lapb_start_t1timer(lapb);
504 lapb_stop_t2timer(lapb);
505 lapb->state = LAPB_STATE_4;
509 if (lapb->condition & LAPB_PEER_RX_BUSY_CONDITION)
510 lapb_frames_acked(lapb, frame->nr);
512 lapb_check_iframes_acked(lapb, frame->nr);
514 if (frame->ns == lapb->vr) {
516 cn = lapb_data_indication(lapb, skb);
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.
525 if (cn == NET_RX_DROP) {
526 printk(KERN_DEBUG "LAPB: rx congestion\n");
529 lapb->vr = (lapb->vr + 1) % modulus;
530 lapb->condition &= ~LAPB_REJECT_CONDITION;
532 lapb_enquiry_response(lapb);
534 if (!(lapb->condition &
535 LAPB_ACK_PENDING_CONDITION)) {
536 lapb->condition |= LAPB_ACK_PENDING_CONDITION;
537 lapb_start_t2timer(lapb);
541 if (lapb->condition & LAPB_REJECT_CONDITION) {
543 lapb_enquiry_response(lapb);
547 "lapb: (%p) S3 TX REJ(%d) R%d\n",
548 lapb->dev, frame->pf, lapb->vr);
550 lapb->condition |= LAPB_REJECT_CONDITION;
551 lapb_send_control(lapb, LAPB_REJ, frame->pf,
553 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
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]);
565 lapb_establish_data_link(lapb);
567 printk(KERN_DEBUG "lapb: (%p) S3 -> S1\n", lapb->dev);
569 lapb_requeue_frames(lapb);
570 lapb->state = LAPB_STATE_1;
575 printk(KERN_DEBUG "lapb: (%p) S3 RX ILLEGAL(%d)\n",
576 lapb->dev, frame->pf);
578 lapb->frmr_data = *frame;
579 lapb->frmr_type = LAPB_FRMR_W;
580 lapb_transmit_frmr(lapb);
582 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
584 lapb_start_t1timer(lapb);
585 lapb_stop_t2timer(lapb);
586 lapb->state = LAPB_STATE_4;
596 * State machine for state 4, Frame Reject State.
597 * The handling of the timer(s) is in file lapb_timer.c.
599 static void lapb_state4_machine(struct lapb_cb *lapb, struct sk_buff *skb,
600 struct lapb_frame *frame)
602 switch (frame->type) {
605 printk(KERN_DEBUG "lapb: (%p) S4 RX SABM(%d)\n",
606 lapb->dev, frame->pf);
608 if (lapb->mode & LAPB_EXTENDED) {
610 printk(KERN_DEBUG "lapb: (%p) S4 TX DM(%d)\n",
611 lapb->dev, frame->pf);
613 lapb_send_control(lapb, LAPB_DM, frame->pf,
617 printk(KERN_DEBUG "lapb: (%p) S4 TX UA(%d)\n",
618 lapb->dev, frame->pf);
621 printk(KERN_DEBUG "lapb: (%p) S4 -> S3\n", lapb->dev);
623 lapb_send_control(lapb, LAPB_UA, frame->pf,
625 lapb_stop_t1timer(lapb);
626 lapb_stop_t2timer(lapb);
627 lapb->state = LAPB_STATE_3;
628 lapb->condition = 0x00;
633 lapb_connect_indication(lapb, LAPB_OK);
639 printk(KERN_DEBUG "lapb: (%p) S4 RX SABME(%d)\n",
640 lapb->dev, frame->pf);
642 if (lapb->mode & LAPB_EXTENDED) {
644 printk(KERN_DEBUG "lapb: (%p) S4 TX UA(%d)\n",
645 lapb->dev, frame->pf);
648 printk(KERN_DEBUG "lapb: (%p) S4 -> S3\n", lapb->dev);
650 lapb_send_control(lapb, LAPB_UA, frame->pf,
652 lapb_stop_t1timer(lapb);
653 lapb_stop_t2timer(lapb);
654 lapb->state = LAPB_STATE_3;
655 lapb->condition = 0x00;
660 lapb_connect_indication(lapb, LAPB_OK);
663 printk(KERN_DEBUG "lapb: (%p) S4 TX DM(%d)\n",
664 lapb->dev, frame->pf);
666 lapb_send_control(lapb, LAPB_DM, frame->pf,
676 * Process an incoming LAPB frame
678 void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *skb)
680 struct lapb_frame frame;
682 if (lapb_decode(lapb, skb, &frame) < 0) {
687 switch (lapb->state) {
689 lapb_state0_machine(lapb, skb, &frame); break;
691 lapb_state1_machine(lapb, skb, &frame); break;
693 lapb_state2_machine(lapb, skb, &frame); break;
695 lapb_state3_machine(lapb, skb, &frame); break;
697 lapb_state4_machine(lapb, skb, &frame); break;