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/sched.h>
24 #include <linux/timer.h>
25 #include <linux/string.h>
26 #include <linux/sockios.h>
27 #include <linux/net.h>
28 #include <linux/inet.h>
29 #include <linux/netdevice.h>
30 #include <linux/skbuff.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(lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame)
45 switch (frame->type) {
48 printk(KERN_DEBUG "lapb: (%p) S0 RX SABM(%d)\n", lapb->token, frame->pf);
50 if (lapb->mode & LAPB_EXTENDED) {
52 printk(KERN_DEBUG "lapb: (%p) S0 TX DM(%d)\n", lapb->token, frame->pf);
54 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
57 printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n", lapb->token, frame->pf);
60 printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n", lapb->token);
62 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
63 lapb_stop_t1timer(lapb);
64 lapb_stop_t2timer(lapb);
65 lapb->state = LAPB_STATE_3;
66 lapb->condition = 0x00;
71 lapb_connect_indication(lapb, LAPB_OK);
77 printk(KERN_DEBUG "lapb: (%p) S0 RX SABME(%d)\n", lapb->token, frame->pf);
79 if (lapb->mode & LAPB_EXTENDED) {
81 printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n", lapb->token, frame->pf);
84 printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n", lapb->token);
86 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
87 lapb_stop_t1timer(lapb);
88 lapb_stop_t2timer(lapb);
89 lapb->state = LAPB_STATE_3;
90 lapb->condition = 0x00;
95 lapb_connect_indication(lapb, LAPB_OK);
98 printk(KERN_DEBUG "lapb: (%p) S0 TX DM(%d)\n", lapb->token, frame->pf);
100 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
106 printk(KERN_DEBUG "lapb: (%p) S0 RX DISC(%d)\n", lapb->token, frame->pf);
107 printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n", lapb->token, frame->pf);
109 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
120 * State machine for state 1, Awaiting Connection State.
121 * The handling of the timer(s) is in file lapb_timer.c.
123 static void lapb_state1_machine(lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame)
125 switch (frame->type) {
128 printk(KERN_DEBUG "lapb: (%p) S1 RX SABM(%d)\n", lapb->token, frame->pf);
130 if (lapb->mode & LAPB_EXTENDED) {
132 printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n", lapb->token, frame->pf);
134 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
137 printk(KERN_DEBUG "lapb: (%p) S1 TX UA(%d)\n", lapb->token, frame->pf);
139 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
145 printk(KERN_DEBUG "lapb: (%p) S1 RX SABME(%d)\n", lapb->token, frame->pf);
147 if (lapb->mode & LAPB_EXTENDED) {
149 printk(KERN_DEBUG "lapb: (%p) S1 TX UA(%d)\n", lapb->token, frame->pf);
151 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
154 printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n", lapb->token, frame->pf);
156 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
162 printk(KERN_DEBUG "lapb: (%p) S1 RX DISC(%d)\n", lapb->token, frame->pf);
163 printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n", lapb->token, frame->pf);
165 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
170 printk(KERN_DEBUG "lapb: (%p) S1 RX UA(%d)\n", lapb->token, frame->pf);
174 printk(KERN_DEBUG "lapb: (%p) S1 -> S3\n", lapb->token);
176 lapb_stop_t1timer(lapb);
177 lapb_stop_t2timer(lapb);
178 lapb->state = LAPB_STATE_3;
179 lapb->condition = 0x00;
184 lapb_connect_confirmation(lapb, LAPB_OK);
190 printk(KERN_DEBUG "lapb: (%p) S1 RX DM(%d)\n", lapb->token, frame->pf);
194 printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->token);
196 lapb_clear_queues(lapb);
197 lapb->state = LAPB_STATE_0;
198 lapb_start_t1timer(lapb);
199 lapb_stop_t2timer(lapb);
200 lapb_disconnect_indication(lapb, LAPB_REFUSED);
212 * State machine for state 2, Awaiting Release State.
213 * The handling of the timer(s) is in file lapb_timer.c
215 static void lapb_state2_machine(lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame)
217 switch (frame->type) {
221 printk(KERN_DEBUG "lapb: (%p) S2 RX {SABM,SABME}(%d)\n", lapb->token, frame->pf);
222 printk(KERN_DEBUG "lapb: (%p) S2 TX DM(%d)\n", lapb->token, frame->pf);
224 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
229 printk(KERN_DEBUG "lapb: (%p) S2 RX DISC(%d)\n", lapb->token, frame->pf);
230 printk(KERN_DEBUG "lapb: (%p) S2 TX UA(%d)\n", lapb->token, frame->pf);
232 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
237 printk(KERN_DEBUG "lapb: (%p) S2 RX UA(%d)\n", lapb->token, frame->pf);
241 printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->token);
243 lapb->state = LAPB_STATE_0;
244 lapb_start_t1timer(lapb);
245 lapb_stop_t2timer(lapb);
246 lapb_disconnect_confirmation(lapb, LAPB_OK);
252 printk(KERN_DEBUG "lapb: (%p) S2 RX DM(%d)\n", lapb->token, frame->pf);
256 printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->token);
258 lapb->state = LAPB_STATE_0;
259 lapb_start_t1timer(lapb);
260 lapb_stop_t2timer(lapb);
261 lapb_disconnect_confirmation(lapb, LAPB_NOTCONNECTED);
270 printk(KERN_DEBUG "lapb: (%p) S2 RX {I,REJ,RNR,RR}(%d)\n", lapb->token, frame->pf);
271 printk(KERN_DEBUG "lapb: (%p) S2 RX DM(%d)\n", lapb->token, frame->pf);
273 if (frame->pf) lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
284 * State machine for state 3, Connected State.
285 * The handling of the timer(s) is in file lapb_timer.c
287 static void lapb_state3_machine(lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame)
292 modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS : LAPB_SMODULUS;
294 switch (frame->type) {
297 printk(KERN_DEBUG "lapb: (%p) S3 RX SABM(%d)\n", lapb->token, frame->pf);
299 if (lapb->mode & LAPB_EXTENDED) {
301 printk(KERN_DEBUG "lapb: (%p) S3 TX DM(%d)\n", lapb->token, frame->pf);
303 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
306 printk(KERN_DEBUG "lapb: (%p) S3 TX UA(%d)\n", lapb->token, frame->pf);
308 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
309 lapb_stop_t1timer(lapb);
310 lapb_stop_t2timer(lapb);
311 lapb->condition = 0x00;
316 lapb_requeue_frames(lapb);
322 printk(KERN_DEBUG "lapb: (%p) S3 RX SABME(%d)\n", lapb->token, frame->pf);
324 if (lapb->mode & LAPB_EXTENDED) {
326 printk(KERN_DEBUG "lapb: (%p) S3 TX UA(%d)\n", lapb->token, frame->pf);
328 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
329 lapb_stop_t1timer(lapb);
330 lapb_stop_t2timer(lapb);
331 lapb->condition = 0x00;
336 lapb_requeue_frames(lapb);
339 printk(KERN_DEBUG "lapb: (%p) S3 TX DM(%d)\n", lapb->token, frame->pf);
341 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
347 printk(KERN_DEBUG "lapb: (%p) S3 RX DISC(%d)\n", lapb->token, frame->pf);
350 printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->token);
352 lapb_clear_queues(lapb);
353 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
354 lapb_start_t1timer(lapb);
355 lapb_stop_t2timer(lapb);
356 lapb->state = LAPB_STATE_0;
357 lapb_disconnect_indication(lapb, LAPB_OK);
362 printk(KERN_DEBUG "lapb: (%p) S3 RX DM(%d)\n", lapb->token, frame->pf);
365 printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->token);
367 lapb_clear_queues(lapb);
368 lapb->state = LAPB_STATE_0;
369 lapb_start_t1timer(lapb);
370 lapb_stop_t2timer(lapb);
371 lapb_disconnect_indication(lapb, LAPB_NOTCONNECTED);
376 printk(KERN_DEBUG "lapb: (%p) S3 RX RNR(%d) R%d\n", lapb->token, frame->pf, frame->nr);
378 lapb->condition |= LAPB_PEER_RX_BUSY_CONDITION;
379 lapb_check_need_response(lapb, frame->cr, frame->pf);
380 if (lapb_validate_nr(lapb, frame->nr)) {
381 lapb_check_iframes_acked(lapb, frame->nr);
383 lapb->frmr_data = *frame;
384 lapb->frmr_type = LAPB_FRMR_Z;
385 lapb_transmit_frmr(lapb);
387 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->token);
389 lapb_start_t1timer(lapb);
390 lapb_stop_t2timer(lapb);
391 lapb->state = LAPB_STATE_4;
398 printk(KERN_DEBUG "lapb: (%p) S3 RX RR(%d) R%d\n", lapb->token, frame->pf, frame->nr);
400 lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
401 lapb_check_need_response(lapb, frame->cr, frame->pf);
402 if (lapb_validate_nr(lapb, frame->nr)) {
403 lapb_check_iframes_acked(lapb, frame->nr);
405 lapb->frmr_data = *frame;
406 lapb->frmr_type = LAPB_FRMR_Z;
407 lapb_transmit_frmr(lapb);
409 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->token);
411 lapb_start_t1timer(lapb);
412 lapb_stop_t2timer(lapb);
413 lapb->state = LAPB_STATE_4;
420 printk(KERN_DEBUG "lapb: (%p) S3 RX REJ(%d) R%d\n", lapb->token, frame->pf, frame->nr);
422 lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
423 lapb_check_need_response(lapb, frame->cr, frame->pf);
424 if (lapb_validate_nr(lapb, frame->nr)) {
425 lapb_frames_acked(lapb, frame->nr);
426 lapb_stop_t1timer(lapb);
428 lapb_requeue_frames(lapb);
430 lapb->frmr_data = *frame;
431 lapb->frmr_type = LAPB_FRMR_Z;
432 lapb_transmit_frmr(lapb);
434 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->token);
436 lapb_start_t1timer(lapb);
437 lapb_stop_t2timer(lapb);
438 lapb->state = LAPB_STATE_4;
445 printk(KERN_DEBUG "lapb: (%p) S3 RX I(%d) S%d R%d\n", lapb->token, frame->pf, frame->ns, frame->nr);
447 if (!lapb_validate_nr(lapb, frame->nr)) {
448 lapb->frmr_data = *frame;
449 lapb->frmr_type = LAPB_FRMR_Z;
450 lapb_transmit_frmr(lapb);
452 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->token);
454 lapb_start_t1timer(lapb);
455 lapb_stop_t2timer(lapb);
456 lapb->state = LAPB_STATE_4;
460 if (lapb->condition & LAPB_PEER_RX_BUSY_CONDITION) {
461 lapb_frames_acked(lapb, frame->nr);
463 lapb_check_iframes_acked(lapb, frame->nr);
465 if (frame->ns == lapb->vr) {
467 cn = lapb_data_indication(lapb, skb);
470 * If upper layer has dropped the frame, we
471 * basically ignore any further protocol
472 * processing. This will cause the peer
473 * to re-transmit the frame later like
474 * a frame lost on the wire.
476 if(cn == NET_RX_DROP){
477 printk(KERN_DEBUG "LAPB: rx congestion\n");
480 lapb->vr = (lapb->vr + 1) % modulus;
481 lapb->condition &= ~LAPB_REJECT_CONDITION;
483 lapb_enquiry_response(lapb);
485 if (!(lapb->condition & LAPB_ACK_PENDING_CONDITION)) {
486 lapb->condition |= LAPB_ACK_PENDING_CONDITION;
487 lapb_start_t2timer(lapb);
491 if (lapb->condition & LAPB_REJECT_CONDITION) {
493 lapb_enquiry_response(lapb);
496 printk(KERN_DEBUG "lapb: (%p) S3 TX REJ(%d) R%d\n", lapb->token, frame->pf, lapb->vr);
498 lapb->condition |= LAPB_REJECT_CONDITION;
499 lapb_send_control(lapb, LAPB_REJ, frame->pf, LAPB_RESPONSE);
500 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
507 printk(KERN_DEBUG "lapb: (%p) S3 RX FRMR(%d) %02X %02X %02X %02X %02X\n", lapb->token, frame->pf, skb->data[0], skb->data[1], skb->data[2], skb->data[3], skb->data[4]);
509 lapb_establish_data_link(lapb);
511 printk(KERN_DEBUG "lapb: (%p) S3 -> S1\n", lapb->token);
513 lapb_requeue_frames(lapb);
514 lapb->state = LAPB_STATE_1;
519 printk(KERN_DEBUG "lapb: (%p) S3 RX ILLEGAL(%d)\n", lapb->token, frame->pf);
521 lapb->frmr_data = *frame;
522 lapb->frmr_type = LAPB_FRMR_W;
523 lapb_transmit_frmr(lapb);
525 printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->token);
527 lapb_start_t1timer(lapb);
528 lapb_stop_t2timer(lapb);
529 lapb->state = LAPB_STATE_4;
542 * State machine for state 4, Frame Reject State.
543 * The handling of the timer(s) is in file lapb_timer.c.
545 static void lapb_state4_machine(lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame)
547 switch (frame->type) {
550 printk(KERN_DEBUG "lapb: (%p) S4 RX SABM(%d)\n", lapb->token, frame->pf);
552 if (lapb->mode & LAPB_EXTENDED) {
554 printk(KERN_DEBUG "lapb: (%p) S4 TX DM(%d)\n", lapb->token, frame->pf);
556 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
559 printk(KERN_DEBUG "lapb: (%p) S4 TX UA(%d)\n", lapb->token, frame->pf);
562 printk(KERN_DEBUG "lapb: (%p) S4 -> S3\n", lapb->token);
564 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
565 lapb_stop_t1timer(lapb);
566 lapb_stop_t2timer(lapb);
567 lapb->state = LAPB_STATE_3;
568 lapb->condition = 0x00;
573 lapb_connect_indication(lapb, LAPB_OK);
579 printk(KERN_DEBUG "lapb: (%p) S4 RX SABME(%d)\n", lapb->token, frame->pf);
581 if (lapb->mode & LAPB_EXTENDED) {
583 printk(KERN_DEBUG "lapb: (%p) S4 TX UA(%d)\n", lapb->token, frame->pf);
586 printk(KERN_DEBUG "lapb: (%p) S4 -> S3\n", lapb->token);
588 lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
589 lapb_stop_t1timer(lapb);
590 lapb_stop_t2timer(lapb);
591 lapb->state = LAPB_STATE_3;
592 lapb->condition = 0x00;
597 lapb_connect_indication(lapb, LAPB_OK);
600 printk(KERN_DEBUG "lapb: (%p) S4 TX DM(%d)\n", lapb->token, frame->pf);
602 lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
614 * Process an incoming LAPB frame
616 void lapb_data_input(lapb_cb *lapb, struct sk_buff *skb)
618 struct lapb_frame frame;
620 lapb_decode(lapb, skb, &frame);
622 switch (lapb->state) {
624 lapb_state0_machine(lapb, skb, &frame);
627 lapb_state1_machine(lapb, skb, &frame);
630 lapb_state2_machine(lapb, skb, &frame);
633 lapb_state3_machine(lapb, skb, &frame);
636 lapb_state4_machine(lapb, skb, &frame);