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1/*********************************************************************
2 *
3 * Filename: irttp.c
4 * Version: 1.2
5 * Description: Tiny Transport Protocol (TTP) implementation
6 * Status: Stable
7 * Author: Dag Brattli <dagb@cs.uit.no>
8 * Created at: Sun Aug 31 20:14:31 1997
9 * Modified at: Wed Jan 5 11:31:27 2000
10 * Modified by: Dag Brattli <dagb@cs.uit.no>
11 *
12 * Copyright (c) 1998-2000 Dag Brattli <dagb@cs.uit.no>,
13 * All Rights Reserved.
14 * Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
15 *
16 * This program is free software; you can redistribute it and/or
17 * modify it under the terms of the GNU General Public License as
18 * published by the Free Software Foundation; either version 2 of
19 * the License, or (at your option) any later version.
20 *
21 * Neither Dag Brattli nor University of Tromsø admit liability nor
22 * provide warranty for any of this software. This material is
23 * provided "AS-IS" and at no charge.
24 *
25 ********************************************************************/
26
27#include <linux/skbuff.h>
28#include <linux/init.h>
29#include <linux/fs.h>
30#include <linux/seq_file.h>
31#include <linux/slab.h>
32#include <linux/export.h>
33
34#include <asm/byteorder.h>
35#include <asm/unaligned.h>
36
37#include <net/irda/irda.h>
38#include <net/irda/irlap.h>
39#include <net/irda/irlmp.h>
40#include <net/irda/parameters.h>
41#include <net/irda/irttp.h>
42
43static struct irttp_cb *irttp;
44
45static void __irttp_close_tsap(struct tsap_cb *self);
46
47static int irttp_data_indication(void *instance, void *sap,
48 struct sk_buff *skb);
49static int irttp_udata_indication(void *instance, void *sap,
50 struct sk_buff *skb);
51static void irttp_disconnect_indication(void *instance, void *sap,
52 LM_REASON reason, struct sk_buff *);
53static void irttp_connect_indication(void *instance, void *sap,
54 struct qos_info *qos, __u32 max_sdu_size,
55 __u8 header_size, struct sk_buff *skb);
56static void irttp_connect_confirm(void *instance, void *sap,
57 struct qos_info *qos, __u32 max_sdu_size,
58 __u8 header_size, struct sk_buff *skb);
59static void irttp_run_tx_queue(struct tsap_cb *self);
60static void irttp_run_rx_queue(struct tsap_cb *self);
61
62static void irttp_flush_queues(struct tsap_cb *self);
63static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
64static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
65static void irttp_todo_expired(unsigned long data);
66static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
67 int get);
68
69static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
70static void irttp_status_indication(void *instance,
71 LINK_STATUS link, LOCK_STATUS lock);
72
73/* Information for parsing parameters in IrTTP */
74static pi_minor_info_t pi_minor_call_table[] = {
75 { NULL, 0 }, /* 0x00 */
76 { irttp_param_max_sdu_size, PV_INTEGER | PV_BIG_ENDIAN } /* 0x01 */
77};
78static pi_major_info_t pi_major_call_table[] = { { pi_minor_call_table, 2 } };
79static pi_param_info_t param_info = { pi_major_call_table, 1, 0x0f, 4 };
80
81/************************ GLOBAL PROCEDURES ************************/
82
83/*
84 * Function irttp_init (void)
85 *
86 * Initialize the IrTTP layer. Called by module initialization code
87 *
88 */
89int __init irttp_init(void)
90{
91 irttp = kzalloc(sizeof(struct irttp_cb), GFP_KERNEL);
92 if (irttp == NULL)
93 return -ENOMEM;
94
95 irttp->magic = TTP_MAGIC;
96
97 irttp->tsaps = hashbin_new(HB_LOCK);
98 if (!irttp->tsaps) {
99 IRDA_ERROR("%s: can't allocate IrTTP hashbin!\n",
100 __func__);
101 kfree(irttp);
102 return -ENOMEM;
103 }
104
105 return 0;
106}
107
108/*
109 * Function irttp_cleanup (void)
110 *
111 * Called by module destruction/cleanup code
112 *
113 */
114void irttp_cleanup(void)
115{
116 /* Check for main structure */
117 IRDA_ASSERT(irttp->magic == TTP_MAGIC, return;);
118
119 /*
120 * Delete hashbin and close all TSAP instances in it
121 */
122 hashbin_delete(irttp->tsaps, (FREE_FUNC) __irttp_close_tsap);
123
124 irttp->magic = 0;
125
126 /* De-allocate main structure */
127 kfree(irttp);
128
129 irttp = NULL;
130}
131
132/*************************** SUBROUTINES ***************************/
133
134/*
135 * Function irttp_start_todo_timer (self, timeout)
136 *
137 * Start todo timer.
138 *
139 * Made it more effient and unsensitive to race conditions - Jean II
140 */
141static inline void irttp_start_todo_timer(struct tsap_cb *self, int timeout)
142{
143 /* Set new value for timer */
144 mod_timer(&self->todo_timer, jiffies + timeout);
145}
146
147/*
148 * Function irttp_todo_expired (data)
149 *
150 * Todo timer has expired!
151 *
152 * One of the restriction of the timer is that it is run only on the timer
153 * interrupt which run every 10ms. This mean that even if you set the timer
154 * with a delay of 0, it may take up to 10ms before it's run.
155 * So, to minimise latency and keep cache fresh, we try to avoid using
156 * it as much as possible.
157 * Note : we can't use tasklets, because they can't be asynchronously
158 * killed (need user context), and we can't guarantee that here...
159 * Jean II
160 */
161static void irttp_todo_expired(unsigned long data)
162{
163 struct tsap_cb *self = (struct tsap_cb *) data;
164
165 /* Check that we still exist */
166 if (!self || self->magic != TTP_TSAP_MAGIC)
167 return;
168
169 IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
170
171 /* Try to make some progress, especially on Tx side - Jean II */
172 irttp_run_rx_queue(self);
173 irttp_run_tx_queue(self);
174
175 /* Check if time for disconnect */
176 if (test_bit(0, &self->disconnect_pend)) {
177 /* Check if it's possible to disconnect yet */
178 if (skb_queue_empty(&self->tx_queue)) {
179 /* Make sure disconnect is not pending anymore */
180 clear_bit(0, &self->disconnect_pend); /* FALSE */
181
182 /* Note : self->disconnect_skb may be NULL */
183 irttp_disconnect_request(self, self->disconnect_skb,
184 P_NORMAL);
185 self->disconnect_skb = NULL;
186 } else {
187 /* Try again later */
188 irttp_start_todo_timer(self, HZ/10);
189
190 /* No reason to try and close now */
191 return;
192 }
193 }
194
195 /* Check if it's closing time */
196 if (self->close_pend)
197 /* Finish cleanup */
198 irttp_close_tsap(self);
199}
200
201/*
202 * Function irttp_flush_queues (self)
203 *
204 * Flushes (removes all frames) in transitt-buffer (tx_list)
205 */
206static void irttp_flush_queues(struct tsap_cb *self)
207{
208 struct sk_buff *skb;
209
210 IRDA_DEBUG(4, "%s()\n", __func__);
211
212 IRDA_ASSERT(self != NULL, return;);
213 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
214
215 /* Deallocate frames waiting to be sent */
216 while ((skb = skb_dequeue(&self->tx_queue)) != NULL)
217 dev_kfree_skb(skb);
218
219 /* Deallocate received frames */
220 while ((skb = skb_dequeue(&self->rx_queue)) != NULL)
221 dev_kfree_skb(skb);
222
223 /* Deallocate received fragments */
224 while ((skb = skb_dequeue(&self->rx_fragments)) != NULL)
225 dev_kfree_skb(skb);
226}
227
228/*
229 * Function irttp_reassemble (self)
230 *
231 * Makes a new (continuous) skb of all the fragments in the fragment
232 * queue
233 *
234 */
235static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self)
236{
237 struct sk_buff *skb, *frag;
238 int n = 0; /* Fragment index */
239
240 IRDA_ASSERT(self != NULL, return NULL;);
241 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return NULL;);
242
243 IRDA_DEBUG(2, "%s(), self->rx_sdu_size=%d\n", __func__,
244 self->rx_sdu_size);
245
246 skb = dev_alloc_skb(TTP_HEADER + self->rx_sdu_size);
247 if (!skb)
248 return NULL;
249
250 /*
251 * Need to reserve space for TTP header in case this skb needs to
252 * be requeued in case delivery failes
253 */
254 skb_reserve(skb, TTP_HEADER);
255 skb_put(skb, self->rx_sdu_size);
256
257 /*
258 * Copy all fragments to a new buffer
259 */
260 while ((frag = skb_dequeue(&self->rx_fragments)) != NULL) {
261 skb_copy_to_linear_data_offset(skb, n, frag->data, frag->len);
262 n += frag->len;
263
264 dev_kfree_skb(frag);
265 }
266
267 IRDA_DEBUG(2,
268 "%s(), frame len=%d, rx_sdu_size=%d, rx_max_sdu_size=%d\n",
269 __func__, n, self->rx_sdu_size, self->rx_max_sdu_size);
270 /* Note : irttp_run_rx_queue() calculate self->rx_sdu_size
271 * by summing the size of all fragments, so we should always
272 * have n == self->rx_sdu_size, except in cases where we
273 * droped the last fragment (when self->rx_sdu_size exceed
274 * self->rx_max_sdu_size), where n < self->rx_sdu_size.
275 * Jean II */
276 IRDA_ASSERT(n <= self->rx_sdu_size, n = self->rx_sdu_size;);
277
278 /* Set the new length */
279 skb_trim(skb, n);
280
281 self->rx_sdu_size = 0;
282
283 return skb;
284}
285
286/*
287 * Function irttp_fragment_skb (skb)
288 *
289 * Fragments a frame and queues all the fragments for transmission
290 *
291 */
292static inline void irttp_fragment_skb(struct tsap_cb *self,
293 struct sk_buff *skb)
294{
295 struct sk_buff *frag;
296 __u8 *frame;
297
298 IRDA_DEBUG(2, "%s()\n", __func__);
299
300 IRDA_ASSERT(self != NULL, return;);
301 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
302 IRDA_ASSERT(skb != NULL, return;);
303
304 /*
305 * Split frame into a number of segments
306 */
307 while (skb->len > self->max_seg_size) {
308 IRDA_DEBUG(2, "%s(), fragmenting ...\n", __func__);
309
310 /* Make new segment */
311 frag = alloc_skb(self->max_seg_size+self->max_header_size,
312 GFP_ATOMIC);
313 if (!frag)
314 return;
315
316 skb_reserve(frag, self->max_header_size);
317
318 /* Copy data from the original skb into this fragment. */
319 skb_copy_from_linear_data(skb, skb_put(frag, self->max_seg_size),
320 self->max_seg_size);
321
322 /* Insert TTP header, with the more bit set */
323 frame = skb_push(frag, TTP_HEADER);
324 frame[0] = TTP_MORE;
325
326 /* Hide the copied data from the original skb */
327 skb_pull(skb, self->max_seg_size);
328
329 /* Queue fragment */
330 skb_queue_tail(&self->tx_queue, frag);
331 }
332 /* Queue what is left of the original skb */
333 IRDA_DEBUG(2, "%s(), queuing last segment\n", __func__);
334
335 frame = skb_push(skb, TTP_HEADER);
336 frame[0] = 0x00; /* Clear more bit */
337
338 /* Queue fragment */
339 skb_queue_tail(&self->tx_queue, skb);
340}
341
342/*
343 * Function irttp_param_max_sdu_size (self, param)
344 *
345 * Handle the MaxSduSize parameter in the connect frames, this function
346 * will be called both when this parameter needs to be inserted into, and
347 * extracted from the connect frames
348 */
349static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
350 int get)
351{
352 struct tsap_cb *self;
353
354 self = instance;
355
356 IRDA_ASSERT(self != NULL, return -1;);
357 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
358
359 if (get)
360 param->pv.i = self->tx_max_sdu_size;
361 else
362 self->tx_max_sdu_size = param->pv.i;
363
364 IRDA_DEBUG(1, "%s(), MaxSduSize=%d\n", __func__, param->pv.i);
365
366 return 0;
367}
368
369/*************************** CLIENT CALLS ***************************/
370/************************** LMP CALLBACKS **************************/
371/* Everything is happily mixed up. Waiting for next clean up - Jean II */
372
373/*
374 * Initialization, that has to be done on new tsap
375 * instance allocation and on duplication
376 */
377static void irttp_init_tsap(struct tsap_cb *tsap)
378{
379 spin_lock_init(&tsap->lock);
380 init_timer(&tsap->todo_timer);
381
382 skb_queue_head_init(&tsap->rx_queue);
383 skb_queue_head_init(&tsap->tx_queue);
384 skb_queue_head_init(&tsap->rx_fragments);
385}
386
387/*
388 * Function irttp_open_tsap (stsap, notify)
389 *
390 * Create TSAP connection endpoint,
391 */
392struct tsap_cb *irttp_open_tsap(__u8 stsap_sel, int credit, notify_t *notify)
393{
394 struct tsap_cb *self;
395 struct lsap_cb *lsap;
396 notify_t ttp_notify;
397
398 IRDA_ASSERT(irttp->magic == TTP_MAGIC, return NULL;);
399
400 /* The IrLMP spec (IrLMP 1.1 p10) says that we have the right to
401 * use only 0x01-0x6F. Of course, we can use LSAP_ANY as well.
402 * JeanII */
403 if ((stsap_sel != LSAP_ANY) &&
404 ((stsap_sel < 0x01) || (stsap_sel >= 0x70))) {
405 IRDA_DEBUG(0, "%s(), invalid tsap!\n", __func__);
406 return NULL;
407 }
408
409 self = kzalloc(sizeof(struct tsap_cb), GFP_ATOMIC);
410 if (self == NULL) {
411 IRDA_DEBUG(0, "%s(), unable to kmalloc!\n", __func__);
412 return NULL;
413 }
414
415 /* Initialize internal objects */
416 irttp_init_tsap(self);
417
418 /* Initialise todo timer */
419 self->todo_timer.data = (unsigned long) self;
420 self->todo_timer.function = &irttp_todo_expired;
421
422 /* Initialize callbacks for IrLMP to use */
423 irda_notify_init(&ttp_notify);
424 ttp_notify.connect_confirm = irttp_connect_confirm;
425 ttp_notify.connect_indication = irttp_connect_indication;
426 ttp_notify.disconnect_indication = irttp_disconnect_indication;
427 ttp_notify.data_indication = irttp_data_indication;
428 ttp_notify.udata_indication = irttp_udata_indication;
429 ttp_notify.flow_indication = irttp_flow_indication;
430 if (notify->status_indication != NULL)
431 ttp_notify.status_indication = irttp_status_indication;
432 ttp_notify.instance = self;
433 strncpy(ttp_notify.name, notify->name, NOTIFY_MAX_NAME);
434
435 self->magic = TTP_TSAP_MAGIC;
436 self->connected = FALSE;
437
438 /*
439 * Create LSAP at IrLMP layer
440 */
441 lsap = irlmp_open_lsap(stsap_sel, &ttp_notify, 0);
442 if (lsap == NULL) {
443 IRDA_DEBUG(0, "%s: unable to allocate LSAP!!\n", __func__);
444 __irttp_close_tsap(self);
445 return NULL;
446 }
447
448 /*
449 * If user specified LSAP_ANY as source TSAP selector, then IrLMP
450 * will replace it with whatever source selector which is free, so
451 * the stsap_sel we have might not be valid anymore
452 */
453 self->stsap_sel = lsap->slsap_sel;
454 IRDA_DEBUG(4, "%s(), stsap_sel=%02x\n", __func__, self->stsap_sel);
455
456 self->notify = *notify;
457 self->lsap = lsap;
458
459 hashbin_insert(irttp->tsaps, (irda_queue_t *) self, (long) self, NULL);
460
461 if (credit > TTP_RX_MAX_CREDIT)
462 self->initial_credit = TTP_RX_MAX_CREDIT;
463 else
464 self->initial_credit = credit;
465
466 return self;
467}
468EXPORT_SYMBOL(irttp_open_tsap);
469
470/*
471 * Function irttp_close (handle)
472 *
473 * Remove an instance of a TSAP. This function should only deal with the
474 * deallocation of the TSAP, and resetting of the TSAPs values;
475 *
476 */
477static void __irttp_close_tsap(struct tsap_cb *self)
478{
479 /* First make sure we're connected. */
480 IRDA_ASSERT(self != NULL, return;);
481 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
482
483 irttp_flush_queues(self);
484
485 del_timer(&self->todo_timer);
486
487 /* This one won't be cleaned up if we are disconnect_pend + close_pend
488 * and we receive a disconnect_indication */
489 if (self->disconnect_skb)
490 dev_kfree_skb(self->disconnect_skb);
491
492 self->connected = FALSE;
493 self->magic = ~TTP_TSAP_MAGIC;
494
495 kfree(self);
496}
497
498/*
499 * Function irttp_close (self)
500 *
501 * Remove TSAP from list of all TSAPs and then deallocate all resources
502 * associated with this TSAP
503 *
504 * Note : because we *free* the tsap structure, it is the responsibility
505 * of the caller to make sure we are called only once and to deal with
506 * possible race conditions. - Jean II
507 */
508int irttp_close_tsap(struct tsap_cb *self)
509{
510 struct tsap_cb *tsap;
511
512 IRDA_DEBUG(4, "%s()\n", __func__);
513
514 IRDA_ASSERT(self != NULL, return -1;);
515 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
516
517 /* Make sure tsap has been disconnected */
518 if (self->connected) {
519 /* Check if disconnect is not pending */
520 if (!test_bit(0, &self->disconnect_pend)) {
521 IRDA_WARNING("%s: TSAP still connected!\n",
522 __func__);
523 irttp_disconnect_request(self, NULL, P_NORMAL);
524 }
525 self->close_pend = TRUE;
526 irttp_start_todo_timer(self, HZ/10);
527
528 return 0; /* Will be back! */
529 }
530
531 tsap = hashbin_remove(irttp->tsaps, (long) self, NULL);
532
533 IRDA_ASSERT(tsap == self, return -1;);
534
535 /* Close corresponding LSAP */
536 if (self->lsap) {
537 irlmp_close_lsap(self->lsap);
538 self->lsap = NULL;
539 }
540
541 __irttp_close_tsap(self);
542
543 return 0;
544}
545EXPORT_SYMBOL(irttp_close_tsap);
546
547/*
548 * Function irttp_udata_request (self, skb)
549 *
550 * Send unreliable data on this TSAP
551 *
552 */
553int irttp_udata_request(struct tsap_cb *self, struct sk_buff *skb)
554{
555 int ret;
556
557 IRDA_ASSERT(self != NULL, return -1;);
558 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
559 IRDA_ASSERT(skb != NULL, return -1;);
560
561 IRDA_DEBUG(4, "%s()\n", __func__);
562
563 /* Take shortcut on zero byte packets */
564 if (skb->len == 0) {
565 ret = 0;
566 goto err;
567 }
568
569 /* Check that nothing bad happens */
570 if (!self->connected) {
571 IRDA_WARNING("%s(), Not connected\n", __func__);
572 ret = -ENOTCONN;
573 goto err;
574 }
575
576 if (skb->len > self->max_seg_size) {
577 IRDA_ERROR("%s(), UData is too large for IrLAP!\n", __func__);
578 ret = -EMSGSIZE;
579 goto err;
580 }
581
582 irlmp_udata_request(self->lsap, skb);
583 self->stats.tx_packets++;
584
585 return 0;
586
587err:
588 dev_kfree_skb(skb);
589 return ret;
590}
591EXPORT_SYMBOL(irttp_udata_request);
592
593
594/*
595 * Function irttp_data_request (handle, skb)
596 *
597 * Queue frame for transmission. If SAR is enabled, fragement the frame
598 * and queue the fragments for transmission
599 */
600int irttp_data_request(struct tsap_cb *self, struct sk_buff *skb)
601{
602 __u8 *frame;
603 int ret;
604
605 IRDA_ASSERT(self != NULL, return -1;);
606 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
607 IRDA_ASSERT(skb != NULL, return -1;);
608
609 IRDA_DEBUG(2, "%s() : queue len = %d\n", __func__,
610 skb_queue_len(&self->tx_queue));
611
612 /* Take shortcut on zero byte packets */
613 if (skb->len == 0) {
614 ret = 0;
615 goto err;
616 }
617
618 /* Check that nothing bad happens */
619 if (!self->connected) {
620 IRDA_WARNING("%s: Not connected\n", __func__);
621 ret = -ENOTCONN;
622 goto err;
623 }
624
625 /*
626 * Check if SAR is disabled, and the frame is larger than what fits
627 * inside an IrLAP frame
628 */
629 if ((self->tx_max_sdu_size == 0) && (skb->len > self->max_seg_size)) {
630 IRDA_ERROR("%s: SAR disabled, and data is too large for IrLAP!\n",
631 __func__);
632 ret = -EMSGSIZE;
633 goto err;
634 }
635
636 /*
637 * Check if SAR is enabled, and the frame is larger than the
638 * TxMaxSduSize
639 */
640 if ((self->tx_max_sdu_size != 0) &&
641 (self->tx_max_sdu_size != TTP_SAR_UNBOUND) &&
642 (skb->len > self->tx_max_sdu_size)) {
643 IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
644 __func__);
645 ret = -EMSGSIZE;
646 goto err;
647 }
648 /*
649 * Check if transmit queue is full
650 */
651 if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
652 /*
653 * Give it a chance to empty itself
654 */
655 irttp_run_tx_queue(self);
656
657 /* Drop packet. This error code should trigger the caller
658 * to resend the data in the client code - Jean II */
659 ret = -ENOBUFS;
660 goto err;
661 }
662
663 /* Queue frame, or queue frame segments */
664 if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
665 /* Queue frame */
666 IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
667 frame = skb_push(skb, TTP_HEADER);
668 frame[0] = 0x00; /* Clear more bit */
669
670 skb_queue_tail(&self->tx_queue, skb);
671 } else {
672 /*
673 * Fragment the frame, this function will also queue the
674 * fragments, we don't care about the fact the transmit
675 * queue may be overfilled by all the segments for a little
676 * while
677 */
678 irttp_fragment_skb(self, skb);
679 }
680
681 /* Check if we can accept more data from client */
682 if ((!self->tx_sdu_busy) &&
683 (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
684 /* Tx queue filling up, so stop client. */
685 if (self->notify.flow_indication) {
686 self->notify.flow_indication(self->notify.instance,
687 self, FLOW_STOP);
688 }
689 /* self->tx_sdu_busy is the state of the client.
690 * Update state after notifying client to avoid
691 * race condition with irttp_flow_indication().
692 * If the queue empty itself after our test but before
693 * we set the flag, we will fix ourselves below in
694 * irttp_run_tx_queue().
695 * Jean II */
696 self->tx_sdu_busy = TRUE;
697 }
698
699 /* Try to make some progress */
700 irttp_run_tx_queue(self);
701
702 return 0;
703
704err:
705 dev_kfree_skb(skb);
706 return ret;
707}
708EXPORT_SYMBOL(irttp_data_request);
709
710/*
711 * Function irttp_run_tx_queue (self)
712 *
713 * Transmit packets queued for transmission (if possible)
714 *
715 */
716static void irttp_run_tx_queue(struct tsap_cb *self)
717{
718 struct sk_buff *skb;
719 unsigned long flags;
720 int n;
721
722 IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
723 __func__,
724 self->send_credit, skb_queue_len(&self->tx_queue));
725
726 /* Get exclusive access to the tx queue, otherwise don't touch it */
727 if (irda_lock(&self->tx_queue_lock) == FALSE)
728 return;
729
730 /* Try to send out frames as long as we have credits
731 * and as long as LAP is not full. If LAP is full, it will
732 * poll us through irttp_flow_indication() - Jean II */
733 while ((self->send_credit > 0) &&
734 (!irlmp_lap_tx_queue_full(self->lsap)) &&
735 (skb = skb_dequeue(&self->tx_queue))) {
736 /*
737 * Since we can transmit and receive frames concurrently,
738 * the code below is a critical region and we must assure that
739 * nobody messes with the credits while we update them.
740 */
741 spin_lock_irqsave(&self->lock, flags);
742
743 n = self->avail_credit;
744 self->avail_credit = 0;
745
746 /* Only room for 127 credits in frame */
747 if (n > 127) {
748 self->avail_credit = n-127;
749 n = 127;
750 }
751 self->remote_credit += n;
752 self->send_credit--;
753
754 spin_unlock_irqrestore(&self->lock, flags);
755
756 /*
757 * More bit must be set by the data_request() or fragment()
758 * functions
759 */
760 skb->data[0] |= (n & 0x7f);
761
762 /* Detach from socket.
763 * The current skb has a reference to the socket that sent
764 * it (skb->sk). When we pass it to IrLMP, the skb will be
765 * stored in in IrLAP (self->wx_list). When we are within
766 * IrLAP, we lose the notion of socket, so we should not
767 * have a reference to a socket. So, we drop it here.
768 *
769 * Why does it matter ?
770 * When the skb is freed (kfree_skb), if it is associated
771 * with a socket, it release buffer space on the socket
772 * (through sock_wfree() and sock_def_write_space()).
773 * If the socket no longer exist, we may crash. Hard.
774 * When we close a socket, we make sure that associated packets
775 * in IrTTP are freed. However, we have no way to cancel
776 * the packet that we have passed to IrLAP. So, if a packet
777 * remains in IrLAP (retry on the link or else) after we
778 * close the socket, we are dead !
779 * Jean II */
780 if (skb->sk != NULL) {
781 /* IrSOCK application, IrOBEX, ... */
782 skb_orphan(skb);
783 }
784 /* IrCOMM over IrTTP, IrLAN, ... */
785
786 /* Pass the skb to IrLMP - done */
787 irlmp_data_request(self->lsap, skb);
788 self->stats.tx_packets++;
789 }
790
791 /* Check if we can accept more frames from client.
792 * We don't want to wait until the todo timer to do that, and we
793 * can't use tasklets (grr...), so we are obliged to give control
794 * to client. That's ok, this test will be true not too often
795 * (max once per LAP window) and we are called from places
796 * where we can spend a bit of time doing stuff. - Jean II */
797 if ((self->tx_sdu_busy) &&
798 (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
799 (!self->close_pend)) {
800 if (self->notify.flow_indication)
801 self->notify.flow_indication(self->notify.instance,
802 self, FLOW_START);
803
804 /* self->tx_sdu_busy is the state of the client.
805 * We don't really have a race here, but it's always safer
806 * to update our state after the client - Jean II */
807 self->tx_sdu_busy = FALSE;
808 }
809
810 /* Reset lock */
811 self->tx_queue_lock = 0;
812}
813
814/*
815 * Function irttp_give_credit (self)
816 *
817 * Send a dataless flowdata TTP-PDU and give available credit to peer
818 * TSAP
819 */
820static inline void irttp_give_credit(struct tsap_cb *self)
821{
822 struct sk_buff *tx_skb = NULL;
823 unsigned long flags;
824 int n;
825
826 IRDA_ASSERT(self != NULL, return;);
827 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
828
829 IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
830 __func__,
831 self->send_credit, self->avail_credit, self->remote_credit);
832
833 /* Give credit to peer */
834 tx_skb = alloc_skb(TTP_MAX_HEADER, GFP_ATOMIC);
835 if (!tx_skb)
836 return;
837
838 /* Reserve space for LMP, and LAP header */
839 skb_reserve(tx_skb, LMP_MAX_HEADER);
840
841 /*
842 * Since we can transmit and receive frames concurrently,
843 * the code below is a critical region and we must assure that
844 * nobody messes with the credits while we update them.
845 */
846 spin_lock_irqsave(&self->lock, flags);
847
848 n = self->avail_credit;
849 self->avail_credit = 0;
850
851 /* Only space for 127 credits in frame */
852 if (n > 127) {
853 self->avail_credit = n - 127;
854 n = 127;
855 }
856 self->remote_credit += n;
857
858 spin_unlock_irqrestore(&self->lock, flags);
859
860 skb_put(tx_skb, 1);
861 tx_skb->data[0] = (__u8) (n & 0x7f);
862
863 irlmp_data_request(self->lsap, tx_skb);
864 self->stats.tx_packets++;
865}
866
867/*
868 * Function irttp_udata_indication (instance, sap, skb)
869 *
870 * Received some unit-data (unreliable)
871 *
872 */
873static int irttp_udata_indication(void *instance, void *sap,
874 struct sk_buff *skb)
875{
876 struct tsap_cb *self;
877 int err;
878
879 IRDA_DEBUG(4, "%s()\n", __func__);
880
881 self = instance;
882
883 IRDA_ASSERT(self != NULL, return -1;);
884 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
885 IRDA_ASSERT(skb != NULL, return -1;);
886
887 self->stats.rx_packets++;
888
889 /* Just pass data to layer above */
890 if (self->notify.udata_indication) {
891 err = self->notify.udata_indication(self->notify.instance,
892 self, skb);
893 /* Same comment as in irttp_do_data_indication() */
894 if (!err)
895 return 0;
896 }
897 /* Either no handler, or handler returns an error */
898 dev_kfree_skb(skb);
899
900 return 0;
901}
902
903/*
904 * Function irttp_data_indication (instance, sap, skb)
905 *
906 * Receive segment from IrLMP.
907 *
908 */
909static int irttp_data_indication(void *instance, void *sap,
910 struct sk_buff *skb)
911{
912 struct tsap_cb *self;
913 unsigned long flags;
914 int n;
915
916 self = instance;
917
918 n = skb->data[0] & 0x7f; /* Extract the credits */
919
920 self->stats.rx_packets++;
921
922 /* Deal with inbound credit
923 * Since we can transmit and receive frames concurrently,
924 * the code below is a critical region and we must assure that
925 * nobody messes with the credits while we update them.
926 */
927 spin_lock_irqsave(&self->lock, flags);
928 self->send_credit += n;
929 if (skb->len > 1)
930 self->remote_credit--;
931 spin_unlock_irqrestore(&self->lock, flags);
932
933 /*
934 * Data or dataless packet? Dataless frames contains only the
935 * TTP_HEADER.
936 */
937 if (skb->len > 1) {
938 /*
939 * We don't remove the TTP header, since we must preserve the
940 * more bit, so the defragment routing knows what to do
941 */
942 skb_queue_tail(&self->rx_queue, skb);
943 } else {
944 /* Dataless flowdata TTP-PDU */
945 dev_kfree_skb(skb);
946 }
947
948
949 /* Push data to the higher layer.
950 * We do it synchronously because running the todo timer for each
951 * receive packet would be too much overhead and latency.
952 * By passing control to the higher layer, we run the risk that
953 * it may take time or grab a lock. Most often, the higher layer
954 * will only put packet in a queue.
955 * Anyway, packets are only dripping through the IrDA, so we can
956 * have time before the next packet.
957 * Further, we are run from NET_BH, so the worse that can happen is
958 * us missing the optimal time to send back the PF bit in LAP.
959 * Jean II */
960 irttp_run_rx_queue(self);
961
962 /* We now give credits to peer in irttp_run_rx_queue().
963 * We need to send credit *NOW*, otherwise we are going
964 * to miss the next Tx window. The todo timer may take
965 * a while before it's run... - Jean II */
966
967 /*
968 * If the peer device has given us some credits and we didn't have
969 * anyone from before, then we need to shedule the tx queue.
970 * We need to do that because our Tx have stopped (so we may not
971 * get any LAP flow indication) and the user may be stopped as
972 * well. - Jean II
973 */
974 if (self->send_credit == n) {
975 /* Restart pushing stuff to LAP */
976 irttp_run_tx_queue(self);
977 /* Note : we don't want to schedule the todo timer
978 * because it has horrible latency. No tasklets
979 * because the tasklet API is broken. - Jean II */
980 }
981
982 return 0;
983}
984
985/*
986 * Function irttp_status_indication (self, reason)
987 *
988 * Status_indication, just pass to the higher layer...
989 *
990 */
991static void irttp_status_indication(void *instance,
992 LINK_STATUS link, LOCK_STATUS lock)
993{
994 struct tsap_cb *self;
995
996 IRDA_DEBUG(4, "%s()\n", __func__);
997
998 self = instance;
999
1000 IRDA_ASSERT(self != NULL, return;);
1001 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1002
1003 /* Check if client has already closed the TSAP and gone away */
1004 if (self->close_pend)
1005 return;
1006
1007 /*
1008 * Inform service user if he has requested it
1009 */
1010 if (self->notify.status_indication != NULL)
1011 self->notify.status_indication(self->notify.instance,
1012 link, lock);
1013 else
1014 IRDA_DEBUG(2, "%s(), no handler\n", __func__);
1015}
1016
1017/*
1018 * Function irttp_flow_indication (self, reason)
1019 *
1020 * Flow_indication : IrLAP tells us to send more data.
1021 *
1022 */
1023static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
1024{
1025 struct tsap_cb *self;
1026
1027 self = instance;
1028
1029 IRDA_ASSERT(self != NULL, return;);
1030 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1031
1032 IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
1033
1034 /* We are "polled" directly from LAP, and the LAP want to fill
1035 * its Tx window. We want to do our best to send it data, so that
1036 * we maximise the window. On the other hand, we want to limit the
1037 * amount of work here so that LAP doesn't hang forever waiting
1038 * for packets. - Jean II */
1039
1040 /* Try to send some packets. Currently, LAP calls us every time
1041 * there is one free slot, so we will send only one packet.
1042 * This allow the scheduler to do its round robin - Jean II */
1043 irttp_run_tx_queue(self);
1044
1045 /* Note regarding the interraction with higher layer.
1046 * irttp_run_tx_queue() may call the client when its queue
1047 * start to empty, via notify.flow_indication(). Initially.
1048 * I wanted this to happen in a tasklet, to avoid client
1049 * grabbing the CPU, but we can't use tasklets safely. And timer
1050 * is definitely too slow.
1051 * This will happen only once per LAP window, and usually at
1052 * the third packet (unless window is smaller). LAP is still
1053 * doing mtt and sending first packet so it's sort of OK
1054 * to do that. Jean II */
1055
1056 /* If we need to send disconnect. try to do it now */
1057 if (self->disconnect_pend)
1058 irttp_start_todo_timer(self, 0);
1059}
1060
1061/*
1062 * Function irttp_flow_request (self, command)
1063 *
1064 * This function could be used by the upper layers to tell IrTTP to stop
1065 * delivering frames if the receive queues are starting to get full, or
1066 * to tell IrTTP to start delivering frames again.
1067 */
1068void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1069{
1070 IRDA_DEBUG(1, "%s()\n", __func__);
1071
1072 IRDA_ASSERT(self != NULL, return;);
1073 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1074
1075 switch (flow) {
1076 case FLOW_STOP:
1077 IRDA_DEBUG(1, "%s(), flow stop\n", __func__);
1078 self->rx_sdu_busy = TRUE;
1079 break;
1080 case FLOW_START:
1081 IRDA_DEBUG(1, "%s(), flow start\n", __func__);
1082 self->rx_sdu_busy = FALSE;
1083
1084 /* Client say he can accept more data, try to free our
1085 * queues ASAP - Jean II */
1086 irttp_run_rx_queue(self);
1087
1088 break;
1089 default:
1090 IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __func__);
1091 }
1092}
1093EXPORT_SYMBOL(irttp_flow_request);
1094
1095/*
1096 * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1097 *
1098 * Try to connect to remote destination TSAP selector
1099 *
1100 */
1101int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1102 __u32 saddr, __u32 daddr,
1103 struct qos_info *qos, __u32 max_sdu_size,
1104 struct sk_buff *userdata)
1105{
1106 struct sk_buff *tx_skb;
1107 __u8 *frame;
1108 __u8 n;
1109
1110 IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __func__, max_sdu_size);
1111
1112 IRDA_ASSERT(self != NULL, return -EBADR;);
1113 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1114
1115 if (self->connected) {
1116 if (userdata)
1117 dev_kfree_skb(userdata);
1118 return -EISCONN;
1119 }
1120
1121 /* Any userdata supplied? */
1122 if (userdata == NULL) {
1123 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1124 GFP_ATOMIC);
1125 if (!tx_skb)
1126 return -ENOMEM;
1127
1128 /* Reserve space for MUX_CONTROL and LAP header */
1129 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1130 } else {
1131 tx_skb = userdata;
1132 /*
1133 * Check that the client has reserved enough space for
1134 * headers
1135 */
1136 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1137 { dev_kfree_skb(userdata); return -1; });
1138 }
1139
1140 /* Initialize connection parameters */
1141 self->connected = FALSE;
1142 self->avail_credit = 0;
1143 self->rx_max_sdu_size = max_sdu_size;
1144 self->rx_sdu_size = 0;
1145 self->rx_sdu_busy = FALSE;
1146 self->dtsap_sel = dtsap_sel;
1147
1148 n = self->initial_credit;
1149
1150 self->remote_credit = 0;
1151 self->send_credit = 0;
1152
1153 /*
1154 * Give away max 127 credits for now
1155 */
1156 if (n > 127) {
1157 self->avail_credit = n - 127;
1158 n = 127;
1159 }
1160
1161 self->remote_credit = n;
1162
1163 /* SAR enabled? */
1164 if (max_sdu_size > 0) {
1165 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1166 { dev_kfree_skb(tx_skb); return -1; });
1167
1168 /* Insert SAR parameters */
1169 frame = skb_push(tx_skb, TTP_HEADER + TTP_SAR_HEADER);
1170
1171 frame[0] = TTP_PARAMETERS | n;
1172 frame[1] = 0x04; /* Length */
1173 frame[2] = 0x01; /* MaxSduSize */
1174 frame[3] = 0x02; /* Value length */
1175
1176 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1177 (__be16 *)(frame+4));
1178 } else {
1179 /* Insert plain TTP header */
1180 frame = skb_push(tx_skb, TTP_HEADER);
1181
1182 /* Insert initial credit in frame */
1183 frame[0] = n & 0x7f;
1184 }
1185
1186 /* Connect with IrLMP. No QoS parameters for now */
1187 return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1188 tx_skb);
1189}
1190EXPORT_SYMBOL(irttp_connect_request);
1191
1192/*
1193 * Function irttp_connect_confirm (handle, qos, skb)
1194 *
1195 * Service user confirms TSAP connection with peer.
1196 *
1197 */
1198static void irttp_connect_confirm(void *instance, void *sap,
1199 struct qos_info *qos, __u32 max_seg_size,
1200 __u8 max_header_size, struct sk_buff *skb)
1201{
1202 struct tsap_cb *self;
1203 int parameters;
1204 int ret;
1205 __u8 plen;
1206 __u8 n;
1207
1208 IRDA_DEBUG(4, "%s()\n", __func__);
1209
1210 self = instance;
1211
1212 IRDA_ASSERT(self != NULL, return;);
1213 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1214 IRDA_ASSERT(skb != NULL, return;);
1215
1216 self->max_seg_size = max_seg_size - TTP_HEADER;
1217 self->max_header_size = max_header_size + TTP_HEADER;
1218
1219 /*
1220 * Check if we have got some QoS parameters back! This should be the
1221 * negotiated QoS for the link.
1222 */
1223 if (qos) {
1224 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1225 qos->baud_rate.bits);
1226 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1227 qos->baud_rate.value);
1228 }
1229
1230 n = skb->data[0] & 0x7f;
1231
1232 IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __func__, n);
1233
1234 self->send_credit = n;
1235 self->tx_max_sdu_size = 0;
1236 self->connected = TRUE;
1237
1238 parameters = skb->data[0] & 0x80;
1239
1240 IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1241 skb_pull(skb, TTP_HEADER);
1242
1243 if (parameters) {
1244 plen = skb->data[0];
1245
1246 ret = irda_param_extract_all(self, skb->data+1,
1247 IRDA_MIN(skb->len-1, plen),
1248 ¶m_info);
1249
1250 /* Any errors in the parameter list? */
1251 if (ret < 0) {
1252 IRDA_WARNING("%s: error extracting parameters\n",
1253 __func__);
1254 dev_kfree_skb(skb);
1255
1256 /* Do not accept this connection attempt */
1257 return;
1258 }
1259 /* Remove parameters */
1260 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1261 }
1262
1263 IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1264 self->send_credit, self->avail_credit, self->remote_credit);
1265
1266 IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __func__,
1267 self->tx_max_sdu_size);
1268
1269 if (self->notify.connect_confirm) {
1270 self->notify.connect_confirm(self->notify.instance, self, qos,
1271 self->tx_max_sdu_size,
1272 self->max_header_size, skb);
1273 } else
1274 dev_kfree_skb(skb);
1275}
1276
1277/*
1278 * Function irttp_connect_indication (handle, skb)
1279 *
1280 * Some other device is connecting to this TSAP
1281 *
1282 */
1283static void irttp_connect_indication(void *instance, void *sap,
1284 struct qos_info *qos, __u32 max_seg_size, __u8 max_header_size,
1285 struct sk_buff *skb)
1286{
1287 struct tsap_cb *self;
1288 struct lsap_cb *lsap;
1289 int parameters;
1290 int ret;
1291 __u8 plen;
1292 __u8 n;
1293
1294 self = instance;
1295
1296 IRDA_ASSERT(self != NULL, return;);
1297 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1298 IRDA_ASSERT(skb != NULL, return;);
1299
1300 lsap = sap;
1301
1302 self->max_seg_size = max_seg_size - TTP_HEADER;
1303 self->max_header_size = max_header_size+TTP_HEADER;
1304
1305 IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __func__, self->stsap_sel);
1306
1307 /* Need to update dtsap_sel if its equal to LSAP_ANY */
1308 self->dtsap_sel = lsap->dlsap_sel;
1309
1310 n = skb->data[0] & 0x7f;
1311
1312 self->send_credit = n;
1313 self->tx_max_sdu_size = 0;
1314
1315 parameters = skb->data[0] & 0x80;
1316
1317 IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1318 skb_pull(skb, TTP_HEADER);
1319
1320 if (parameters) {
1321 plen = skb->data[0];
1322
1323 ret = irda_param_extract_all(self, skb->data+1,
1324 IRDA_MIN(skb->len-1, plen),
1325 ¶m_info);
1326
1327 /* Any errors in the parameter list? */
1328 if (ret < 0) {
1329 IRDA_WARNING("%s: error extracting parameters\n",
1330 __func__);
1331 dev_kfree_skb(skb);
1332
1333 /* Do not accept this connection attempt */
1334 return;
1335 }
1336
1337 /* Remove parameters */
1338 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1339 }
1340
1341 if (self->notify.connect_indication) {
1342 self->notify.connect_indication(self->notify.instance, self,
1343 qos, self->tx_max_sdu_size,
1344 self->max_header_size, skb);
1345 } else
1346 dev_kfree_skb(skb);
1347}
1348
1349/*
1350 * Function irttp_connect_response (handle, userdata)
1351 *
1352 * Service user is accepting the connection, just pass it down to
1353 * IrLMP!
1354 *
1355 */
1356int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1357 struct sk_buff *userdata)
1358{
1359 struct sk_buff *tx_skb;
1360 __u8 *frame;
1361 int ret;
1362 __u8 n;
1363
1364 IRDA_ASSERT(self != NULL, return -1;);
1365 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1366
1367 IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __func__,
1368 self->stsap_sel);
1369
1370 /* Any userdata supplied? */
1371 if (userdata == NULL) {
1372 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1373 GFP_ATOMIC);
1374 if (!tx_skb)
1375 return -ENOMEM;
1376
1377 /* Reserve space for MUX_CONTROL and LAP header */
1378 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1379 } else {
1380 tx_skb = userdata;
1381 /*
1382 * Check that the client has reserved enough space for
1383 * headers
1384 */
1385 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1386 { dev_kfree_skb(userdata); return -1; });
1387 }
1388
1389 self->avail_credit = 0;
1390 self->remote_credit = 0;
1391 self->rx_max_sdu_size = max_sdu_size;
1392 self->rx_sdu_size = 0;
1393 self->rx_sdu_busy = FALSE;
1394
1395 n = self->initial_credit;
1396
1397 /* Frame has only space for max 127 credits (7 bits) */
1398 if (n > 127) {
1399 self->avail_credit = n - 127;
1400 n = 127;
1401 }
1402
1403 self->remote_credit = n;
1404 self->connected = TRUE;
1405
1406 /* SAR enabled? */
1407 if (max_sdu_size > 0) {
1408 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1409 { dev_kfree_skb(tx_skb); return -1; });
1410
1411 /* Insert TTP header with SAR parameters */
1412 frame = skb_push(tx_skb, TTP_HEADER + TTP_SAR_HEADER);
1413
1414 frame[0] = TTP_PARAMETERS | n;
1415 frame[1] = 0x04; /* Length */
1416
1417 /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1, */
1418/* TTP_SAR_HEADER, ¶m_info) */
1419
1420 frame[2] = 0x01; /* MaxSduSize */
1421 frame[3] = 0x02; /* Value length */
1422
1423 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1424 (__be16 *)(frame+4));
1425 } else {
1426 /* Insert TTP header */
1427 frame = skb_push(tx_skb, TTP_HEADER);
1428
1429 frame[0] = n & 0x7f;
1430 }
1431
1432 ret = irlmp_connect_response(self->lsap, tx_skb);
1433
1434 return ret;
1435}
1436EXPORT_SYMBOL(irttp_connect_response);
1437
1438/*
1439 * Function irttp_dup (self, instance)
1440 *
1441 * Duplicate TSAP, can be used by servers to confirm a connection on a
1442 * new TSAP so it can keep listening on the old one.
1443 */
1444struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1445{
1446 struct tsap_cb *new;
1447 unsigned long flags;
1448
1449 IRDA_DEBUG(1, "%s()\n", __func__);
1450
1451 /* Protect our access to the old tsap instance */
1452 spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1453
1454 /* Find the old instance */
1455 if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1456 IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __func__);
1457 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1458 return NULL;
1459 }
1460
1461 /* Allocate a new instance */
1462 new = kmemdup(orig, sizeof(struct tsap_cb), GFP_ATOMIC);
1463 if (!new) {
1464 IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __func__);
1465 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1466 return NULL;
1467 }
1468 spin_lock_init(&new->lock);
1469
1470 /* We don't need the old instance any more */
1471 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1472
1473 /* Try to dup the LSAP (may fail if we were too slow) */
1474 new->lsap = irlmp_dup(orig->lsap, new);
1475 if (!new->lsap) {
1476 IRDA_DEBUG(0, "%s(), dup failed!\n", __func__);
1477 kfree(new);
1478 return NULL;
1479 }
1480
1481 /* Not everything should be copied */
1482 new->notify.instance = instance;
1483
1484 /* Initialize internal objects */
1485 irttp_init_tsap(new);
1486
1487 /* This is locked */
1488 hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
1489
1490 return new;
1491}
1492EXPORT_SYMBOL(irttp_dup);
1493
1494/*
1495 * Function irttp_disconnect_request (self)
1496 *
1497 * Close this connection please! If priority is high, the queued data
1498 * segments, if any, will be deallocated first
1499 *
1500 */
1501int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1502 int priority)
1503{
1504 int ret;
1505
1506 IRDA_ASSERT(self != NULL, return -1;);
1507 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1508
1509 /* Already disconnected? */
1510 if (!self->connected) {
1511 IRDA_DEBUG(4, "%s(), already disconnected!\n", __func__);
1512 if (userdata)
1513 dev_kfree_skb(userdata);
1514 return -1;
1515 }
1516
1517 /* Disconnect already pending ?
1518 * We need to use an atomic operation to prevent reentry. This
1519 * function may be called from various context, like user, timer
1520 * for following a disconnect_indication() (i.e. net_bh).
1521 * Jean II */
1522 if (test_and_set_bit(0, &self->disconnect_pend)) {
1523 IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1524 __func__);
1525 if (userdata)
1526 dev_kfree_skb(userdata);
1527
1528 /* Try to make some progress */
1529 irttp_run_tx_queue(self);
1530 return -1;
1531 }
1532
1533 /*
1534 * Check if there is still data segments in the transmit queue
1535 */
1536 if (!skb_queue_empty(&self->tx_queue)) {
1537 if (priority == P_HIGH) {
1538 /*
1539 * No need to send the queued data, if we are
1540 * disconnecting right now since the data will
1541 * not have any usable connection to be sent on
1542 */
1543 IRDA_DEBUG(1, "%s(): High priority!!()\n", __func__);
1544 irttp_flush_queues(self);
1545 } else if (priority == P_NORMAL) {
1546 /*
1547 * Must delay disconnect until after all data segments
1548 * have been sent and the tx_queue is empty
1549 */
1550 /* We'll reuse this one later for the disconnect */
1551 self->disconnect_skb = userdata; /* May be NULL */
1552
1553 irttp_run_tx_queue(self);
1554
1555 irttp_start_todo_timer(self, HZ/10);
1556 return -1;
1557 }
1558 }
1559 /* Note : we don't need to check if self->rx_queue is full and the
1560 * state of self->rx_sdu_busy because the disconnect response will
1561 * be sent at the LMP level (so even if the peer has its Tx queue
1562 * full of data). - Jean II */
1563
1564 IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __func__);
1565 self->connected = FALSE;
1566
1567 if (!userdata) {
1568 struct sk_buff *tx_skb;
1569 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
1570 if (!tx_skb)
1571 return -ENOMEM;
1572
1573 /*
1574 * Reserve space for MUX and LAP header
1575 */
1576 skb_reserve(tx_skb, LMP_MAX_HEADER);
1577
1578 userdata = tx_skb;
1579 }
1580 ret = irlmp_disconnect_request(self->lsap, userdata);
1581
1582 /* The disconnect is no longer pending */
1583 clear_bit(0, &self->disconnect_pend); /* FALSE */
1584
1585 return ret;
1586}
1587EXPORT_SYMBOL(irttp_disconnect_request);
1588
1589/*
1590 * Function irttp_disconnect_indication (self, reason)
1591 *
1592 * Disconnect indication, TSAP disconnected by peer?
1593 *
1594 */
1595static void irttp_disconnect_indication(void *instance, void *sap,
1596 LM_REASON reason, struct sk_buff *skb)
1597{
1598 struct tsap_cb *self;
1599
1600 IRDA_DEBUG(4, "%s()\n", __func__);
1601
1602 self = instance;
1603
1604 IRDA_ASSERT(self != NULL, return;);
1605 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1606
1607 /* Prevent higher layer to send more data */
1608 self->connected = FALSE;
1609
1610 /* Check if client has already tried to close the TSAP */
1611 if (self->close_pend) {
1612 /* In this case, the higher layer is probably gone. Don't
1613 * bother it and clean up the remains - Jean II */
1614 if (skb)
1615 dev_kfree_skb(skb);
1616 irttp_close_tsap(self);
1617 return;
1618 }
1619
1620 /* If we are here, we assume that is the higher layer is still
1621 * waiting for the disconnect notification and able to process it,
1622 * even if he tried to disconnect. Otherwise, it would have already
1623 * attempted to close the tsap and self->close_pend would be TRUE.
1624 * Jean II */
1625
1626 /* No need to notify the client if has already tried to disconnect */
1627 if (self->notify.disconnect_indication)
1628 self->notify.disconnect_indication(self->notify.instance, self,
1629 reason, skb);
1630 else
1631 if (skb)
1632 dev_kfree_skb(skb);
1633}
1634
1635/*
1636 * Function irttp_do_data_indication (self, skb)
1637 *
1638 * Try to deliver reassembled skb to layer above, and requeue it if that
1639 * for some reason should fail. We mark rx sdu as busy to apply back
1640 * pressure is necessary.
1641 */
1642static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1643{
1644 int err;
1645
1646 /* Check if client has already closed the TSAP and gone away */
1647 if (self->close_pend) {
1648 dev_kfree_skb(skb);
1649 return;
1650 }
1651
1652 err = self->notify.data_indication(self->notify.instance, self, skb);
1653
1654 /* Usually the layer above will notify that it's input queue is
1655 * starting to get filled by using the flow request, but this may
1656 * be difficult, so it can instead just refuse to eat it and just
1657 * give an error back
1658 */
1659 if (err) {
1660 IRDA_DEBUG(0, "%s() requeueing skb!\n", __func__);
1661
1662 /* Make sure we take a break */
1663 self->rx_sdu_busy = TRUE;
1664
1665 /* Need to push the header in again */
1666 skb_push(skb, TTP_HEADER);
1667 skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1668
1669 /* Put skb back on queue */
1670 skb_queue_head(&self->rx_queue, skb);
1671 }
1672}
1673
1674/*
1675 * Function irttp_run_rx_queue (self)
1676 *
1677 * Check if we have any frames to be transmitted, or if we have any
1678 * available credit to give away.
1679 */
1680static void irttp_run_rx_queue(struct tsap_cb *self)
1681{
1682 struct sk_buff *skb;
1683 int more = 0;
1684
1685 IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1686 self->send_credit, self->avail_credit, self->remote_credit);
1687
1688 /* Get exclusive access to the rx queue, otherwise don't touch it */
1689 if (irda_lock(&self->rx_queue_lock) == FALSE)
1690 return;
1691
1692 /*
1693 * Reassemble all frames in receive queue and deliver them
1694 */
1695 while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1696 /* This bit will tell us if it's the last fragment or not */
1697 more = skb->data[0] & 0x80;
1698
1699 /* Remove TTP header */
1700 skb_pull(skb, TTP_HEADER);
1701
1702 /* Add the length of the remaining data */
1703 self->rx_sdu_size += skb->len;
1704
1705 /*
1706 * If SAR is disabled, or user has requested no reassembly
1707 * of received fragments then we just deliver them
1708 * immediately. This can be requested by clients that
1709 * implements byte streams without any message boundaries
1710 */
1711 if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1712 irttp_do_data_indication(self, skb);
1713 self->rx_sdu_size = 0;
1714
1715 continue;
1716 }
1717
1718 /* Check if this is a fragment, and not the last fragment */
1719 if (more) {
1720 /*
1721 * Queue the fragment if we still are within the
1722 * limits of the maximum size of the rx_sdu
1723 */
1724 if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1725 IRDA_DEBUG(4, "%s(), queueing frag\n",
1726 __func__);
1727 skb_queue_tail(&self->rx_fragments, skb);
1728 } else {
1729 /* Free the part of the SDU that is too big */
1730 dev_kfree_skb(skb);
1731 }
1732 continue;
1733 }
1734 /*
1735 * This is the last fragment, so time to reassemble!
1736 */
1737 if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1738 (self->rx_max_sdu_size == TTP_SAR_UNBOUND)) {
1739 /*
1740 * A little optimizing. Only queue the fragment if
1741 * there are other fragments. Since if this is the
1742 * last and only fragment, there is no need to
1743 * reassemble :-)
1744 */
1745 if (!skb_queue_empty(&self->rx_fragments)) {
1746 skb_queue_tail(&self->rx_fragments,
1747 skb);
1748
1749 skb = irttp_reassemble_skb(self);
1750 }
1751
1752 /* Now we can deliver the reassembled skb */
1753 irttp_do_data_indication(self, skb);
1754 } else {
1755 IRDA_DEBUG(1, "%s(), Truncated frame\n", __func__);
1756
1757 /* Free the part of the SDU that is too big */
1758 dev_kfree_skb(skb);
1759
1760 /* Deliver only the valid but truncated part of SDU */
1761 skb = irttp_reassemble_skb(self);
1762
1763 irttp_do_data_indication(self, skb);
1764 }
1765 self->rx_sdu_size = 0;
1766 }
1767
1768 /*
1769 * It's not trivial to keep track of how many credits are available
1770 * by incrementing at each packet, because delivery may fail
1771 * (irttp_do_data_indication() may requeue the frame) and because
1772 * we need to take care of fragmentation.
1773 * We want the other side to send up to initial_credit packets.
1774 * We have some frames in our queues, and we have already allowed it
1775 * to send remote_credit.
1776 * No need to spinlock, write is atomic and self correcting...
1777 * Jean II
1778 */
1779 self->avail_credit = (self->initial_credit -
1780 (self->remote_credit +
1781 skb_queue_len(&self->rx_queue) +
1782 skb_queue_len(&self->rx_fragments)));
1783
1784 /* Do we have too much credits to send to peer ? */
1785 if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1786 (self->avail_credit > 0)) {
1787 /* Send explicit credit frame */
1788 irttp_give_credit(self);
1789 /* Note : do *NOT* check if tx_queue is non-empty, that
1790 * will produce deadlocks. I repeat : send a credit frame
1791 * even if we have something to send in our Tx queue.
1792 * If we have credits, it means that our Tx queue is blocked.
1793 *
1794 * Let's suppose the peer can't keep up with our Tx. He will
1795 * flow control us by not sending us any credits, and we
1796 * will stop Tx and start accumulating credits here.
1797 * Up to the point where the peer will stop its Tx queue,
1798 * for lack of credits.
1799 * Let's assume the peer application is single threaded.
1800 * It will block on Tx and never consume any Rx buffer.
1801 * Deadlock. Guaranteed. - Jean II
1802 */
1803 }
1804
1805 /* Reset lock */
1806 self->rx_queue_lock = 0;
1807}
1808
1809#ifdef CONFIG_PROC_FS
1810struct irttp_iter_state {
1811 int id;
1812};
1813
1814static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1815{
1816 struct irttp_iter_state *iter = seq->private;
1817 struct tsap_cb *self;
1818
1819 /* Protect our access to the tsap list */
1820 spin_lock_irq(&irttp->tsaps->hb_spinlock);
1821 iter->id = 0;
1822
1823 for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1824 self != NULL;
1825 self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1826 if (iter->id == *pos)
1827 break;
1828 ++iter->id;
1829 }
1830
1831 return self;
1832}
1833
1834static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1835{
1836 struct irttp_iter_state *iter = seq->private;
1837
1838 ++*pos;
1839 ++iter->id;
1840 return (void *) hashbin_get_next(irttp->tsaps);
1841}
1842
1843static void irttp_seq_stop(struct seq_file *seq, void *v)
1844{
1845 spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1846}
1847
1848static int irttp_seq_show(struct seq_file *seq, void *v)
1849{
1850 const struct irttp_iter_state *iter = seq->private;
1851 const struct tsap_cb *self = v;
1852
1853 seq_printf(seq, "TSAP %d, ", iter->id);
1854 seq_printf(seq, "stsap_sel: %02x, ",
1855 self->stsap_sel);
1856 seq_printf(seq, "dtsap_sel: %02x\n",
1857 self->dtsap_sel);
1858 seq_printf(seq, " connected: %s, ",
1859 self->connected ? "TRUE" : "FALSE");
1860 seq_printf(seq, "avail credit: %d, ",
1861 self->avail_credit);
1862 seq_printf(seq, "remote credit: %d, ",
1863 self->remote_credit);
1864 seq_printf(seq, "send credit: %d\n",
1865 self->send_credit);
1866 seq_printf(seq, " tx packets: %lu, ",
1867 self->stats.tx_packets);
1868 seq_printf(seq, "rx packets: %lu, ",
1869 self->stats.rx_packets);
1870 seq_printf(seq, "tx_queue len: %u ",
1871 skb_queue_len(&self->tx_queue));
1872 seq_printf(seq, "rx_queue len: %u\n",
1873 skb_queue_len(&self->rx_queue));
1874 seq_printf(seq, " tx_sdu_busy: %s, ",
1875 self->tx_sdu_busy ? "TRUE" : "FALSE");
1876 seq_printf(seq, "rx_sdu_busy: %s\n",
1877 self->rx_sdu_busy ? "TRUE" : "FALSE");
1878 seq_printf(seq, " max_seg_size: %u, ",
1879 self->max_seg_size);
1880 seq_printf(seq, "tx_max_sdu_size: %u, ",
1881 self->tx_max_sdu_size);
1882 seq_printf(seq, "rx_max_sdu_size: %u\n",
1883 self->rx_max_sdu_size);
1884
1885 seq_printf(seq, " Used by (%s)\n\n",
1886 self->notify.name);
1887 return 0;
1888}
1889
1890static const struct seq_operations irttp_seq_ops = {
1891 .start = irttp_seq_start,
1892 .next = irttp_seq_next,
1893 .stop = irttp_seq_stop,
1894 .show = irttp_seq_show,
1895};
1896
1897static int irttp_seq_open(struct inode *inode, struct file *file)
1898{
1899 return seq_open_private(file, &irttp_seq_ops,
1900 sizeof(struct irttp_iter_state));
1901}
1902
1903const struct file_operations irttp_seq_fops = {
1904 .owner = THIS_MODULE,
1905 .open = irttp_seq_open,
1906 .read = seq_read,
1907 .llseek = seq_lseek,
1908 .release = seq_release_private,
1909};
1910
1911#endif /* PROC_FS */