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