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
43 static struct irttp_cb *irttp;
44
45 static void __irttp_close_tsap(struct tsap_cb *self);
46
47 static int irttp_data_indication(void *instance, void *sap,
48 struct sk_buff *skb);
49 static int irttp_udata_indication(void *instance, void *sap,
50 struct sk_buff *skb);
51 static void irttp_disconnect_indication(void *instance, void *sap,
52 LM_REASON reason, struct sk_buff *);
53 static 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);
56 static 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);
59 static void irttp_run_tx_queue(struct tsap_cb *self);
60 static void irttp_run_rx_queue(struct tsap_cb *self);
61
62 static void irttp_flush_queues(struct tsap_cb *self);
63 static void irttp_fragment_skb(struct tsap_cb *self, struct sk_buff *skb);
64 static struct sk_buff *irttp_reassemble_skb(struct tsap_cb *self);
65 static void irttp_todo_expired(unsigned long data);
66 static int irttp_param_max_sdu_size(void *instance, irda_param_t *param,
67 int get);
68
69 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow);
70 static void irttp_status_indication(void *instance,
71 LINK_STATUS link, LOCK_STATUS lock);
72
73 /* Information for parsing parameters in IrTTP */
74 static 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 };
78 static pi_major_info_t pi_major_call_table[] = {{ pi_minor_call_table, 2 }};
79 static 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 */
89 int __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 */
114 void 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 */
141 static 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 */
161 static 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 */
206 static 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 */
235 static 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 */
292 static 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 */
349 static 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 */
377 static 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 */
392 struct 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 }
468 EXPORT_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 */
477 static 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 */
508 int 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 }
545 EXPORT_SYMBOL(irttp_close_tsap);
546
547 /*
548 * Function irttp_udata_request (self, skb)
549 *
550 * Send unreliable data on this TSAP
551 *
552 */
553 int 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
587 err:
588 dev_kfree_skb(skb);
589 return ret;
590 }
591 EXPORT_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 */
600 int 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 {
644 IRDA_ERROR("%s: SAR enabled, but data is larger than TxMaxSduSize!\n",
645 __func__);
646 ret = -EMSGSIZE;
647 goto err;
648 }
649 /*
650 * Check if transmit queue is full
651 */
652 if (skb_queue_len(&self->tx_queue) >= TTP_TX_MAX_QUEUE) {
653 /*
654 * Give it a chance to empty itself
655 */
656 irttp_run_tx_queue(self);
657
658 /* Drop packet. This error code should trigger the caller
659 * to resend the data in the client code - Jean II */
660 ret = -ENOBUFS;
661 goto err;
662 }
663
664 /* Queue frame, or queue frame segments */
665 if ((self->tx_max_sdu_size == 0) || (skb->len < self->max_seg_size)) {
666 /* Queue frame */
667 IRDA_ASSERT(skb_headroom(skb) >= TTP_HEADER, return -1;);
668 frame = skb_push(skb, TTP_HEADER);
669 frame[0] = 0x00; /* Clear more bit */
670
671 skb_queue_tail(&self->tx_queue, skb);
672 } else {
673 /*
674 * Fragment the frame, this function will also queue the
675 * fragments, we don't care about the fact the transmit
676 * queue may be overfilled by all the segments for a little
677 * while
678 */
679 irttp_fragment_skb(self, skb);
680 }
681
682 /* Check if we can accept more data from client */
683 if ((!self->tx_sdu_busy) &&
684 (skb_queue_len(&self->tx_queue) > TTP_TX_HIGH_THRESHOLD)) {
685 /* Tx queue filling up, so stop client. */
686 if (self->notify.flow_indication) {
687 self->notify.flow_indication(self->notify.instance,
688 self, FLOW_STOP);
689 }
690 /* self->tx_sdu_busy is the state of the client.
691 * Update state after notifying client to avoid
692 * race condition with irttp_flow_indication().
693 * If the queue empty itself after our test but before
694 * we set the flag, we will fix ourselves below in
695 * irttp_run_tx_queue().
696 * Jean II */
697 self->tx_sdu_busy = TRUE;
698 }
699
700 /* Try to make some progress */
701 irttp_run_tx_queue(self);
702
703 return 0;
704
705 err:
706 dev_kfree_skb(skb);
707 return ret;
708 }
709 EXPORT_SYMBOL(irttp_data_request);
710
711 /*
712 * Function irttp_run_tx_queue (self)
713 *
714 * Transmit packets queued for transmission (if possible)
715 *
716 */
717 static void irttp_run_tx_queue(struct tsap_cb *self)
718 {
719 struct sk_buff *skb;
720 unsigned long flags;
721 int n;
722
723 IRDA_DEBUG(2, "%s() : send_credit = %d, queue_len = %d\n",
724 __func__,
725 self->send_credit, skb_queue_len(&self->tx_queue));
726
727 /* Get exclusive access to the tx queue, otherwise don't touch it */
728 if (irda_lock(&self->tx_queue_lock) == FALSE)
729 return;
730
731 /* Try to send out frames as long as we have credits
732 * and as long as LAP is not full. If LAP is full, it will
733 * poll us through irttp_flow_indication() - Jean II */
734 while ((self->send_credit > 0) &&
735 (!irlmp_lap_tx_queue_full(self->lsap)) &&
736 (skb = skb_dequeue(&self->tx_queue)))
737 {
738 /*
739 * Since we can transmit and receive frames concurrently,
740 * the code below is a critical region and we must assure that
741 * nobody messes with the credits while we update them.
742 */
743 spin_lock_irqsave(&self->lock, flags);
744
745 n = self->avail_credit;
746 self->avail_credit = 0;
747
748 /* Only room for 127 credits in frame */
749 if (n > 127) {
750 self->avail_credit = n-127;
751 n = 127;
752 }
753 self->remote_credit += n;
754 self->send_credit--;
755
756 spin_unlock_irqrestore(&self->lock, flags);
757
758 /*
759 * More bit must be set by the data_request() or fragment()
760 * functions
761 */
762 skb->data[0] |= (n & 0x7f);
763
764 /* Detach from socket.
765 * The current skb has a reference to the socket that sent
766 * it (skb->sk). When we pass it to IrLMP, the skb will be
767 * stored in in IrLAP (self->wx_list). When we are within
768 * IrLAP, we lose the notion of socket, so we should not
769 * have a reference to a socket. So, we drop it here.
770 *
771 * Why does it matter ?
772 * When the skb is freed (kfree_skb), if it is associated
773 * with a socket, it release buffer space on the socket
774 * (through sock_wfree() and sock_def_write_space()).
775 * If the socket no longer exist, we may crash. Hard.
776 * When we close a socket, we make sure that associated packets
777 * in IrTTP are freed. However, we have no way to cancel
778 * the packet that we have passed to IrLAP. So, if a packet
779 * remains in IrLAP (retry on the link or else) after we
780 * close the socket, we are dead !
781 * Jean II */
782 if (skb->sk != NULL) {
783 /* IrSOCK application, IrOBEX, ... */
784 skb_orphan(skb);
785 }
786 /* IrCOMM over IrTTP, IrLAN, ... */
787
788 /* Pass the skb to IrLMP - done */
789 irlmp_data_request(self->lsap, skb);
790 self->stats.tx_packets++;
791 }
792
793 /* Check if we can accept more frames from client.
794 * We don't want to wait until the todo timer to do that, and we
795 * can't use tasklets (grr...), so we are obliged to give control
796 * to client. That's ok, this test will be true not too often
797 * (max once per LAP window) and we are called from places
798 * where we can spend a bit of time doing stuff. - Jean II */
799 if ((self->tx_sdu_busy) &&
800 (skb_queue_len(&self->tx_queue) < TTP_TX_LOW_THRESHOLD) &&
801 (!self->close_pend))
802 {
803 if (self->notify.flow_indication)
804 self->notify.flow_indication(self->notify.instance,
805 self, FLOW_START);
806
807 /* self->tx_sdu_busy is the state of the client.
808 * We don't really have a race here, but it's always safer
809 * to update our state after the client - Jean II */
810 self->tx_sdu_busy = FALSE;
811 }
812
813 /* Reset lock */
814 self->tx_queue_lock = 0;
815 }
816
817 /*
818 * Function irttp_give_credit (self)
819 *
820 * Send a dataless flowdata TTP-PDU and give available credit to peer
821 * TSAP
822 */
823 static inline void irttp_give_credit(struct tsap_cb *self)
824 {
825 struct sk_buff *tx_skb = NULL;
826 unsigned long flags;
827 int n;
828
829 IRDA_ASSERT(self != NULL, return;);
830 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
831
832 IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n",
833 __func__,
834 self->send_credit, self->avail_credit, self->remote_credit);
835
836 /* Give credit to peer */
837 tx_skb = alloc_skb(TTP_MAX_HEADER, GFP_ATOMIC);
838 if (!tx_skb)
839 return;
840
841 /* Reserve space for LMP, and LAP header */
842 skb_reserve(tx_skb, LMP_MAX_HEADER);
843
844 /*
845 * Since we can transmit and receive frames concurrently,
846 * the code below is a critical region and we must assure that
847 * nobody messes with the credits while we update them.
848 */
849 spin_lock_irqsave(&self->lock, flags);
850
851 n = self->avail_credit;
852 self->avail_credit = 0;
853
854 /* Only space for 127 credits in frame */
855 if (n > 127) {
856 self->avail_credit = n - 127;
857 n = 127;
858 }
859 self->remote_credit += n;
860
861 spin_unlock_irqrestore(&self->lock, flags);
862
863 skb_put(tx_skb, 1);
864 tx_skb->data[0] = (__u8) (n & 0x7f);
865
866 irlmp_data_request(self->lsap, tx_skb);
867 self->stats.tx_packets++;
868 }
869
870 /*
871 * Function irttp_udata_indication (instance, sap, skb)
872 *
873 * Received some unit-data (unreliable)
874 *
875 */
876 static int irttp_udata_indication(void *instance, void *sap,
877 struct sk_buff *skb)
878 {
879 struct tsap_cb *self;
880 int err;
881
882 IRDA_DEBUG(4, "%s()\n", __func__);
883
884 self = instance;
885
886 IRDA_ASSERT(self != NULL, return -1;);
887 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
888 IRDA_ASSERT(skb != NULL, return -1;);
889
890 self->stats.rx_packets++;
891
892 /* Just pass data to layer above */
893 if (self->notify.udata_indication) {
894 err = self->notify.udata_indication(self->notify.instance,
895 self,skb);
896 /* Same comment as in irttp_do_data_indication() */
897 if (!err)
898 return 0;
899 }
900 /* Either no handler, or handler returns an error */
901 dev_kfree_skb(skb);
902
903 return 0;
904 }
905
906 /*
907 * Function irttp_data_indication (instance, sap, skb)
908 *
909 * Receive segment from IrLMP.
910 *
911 */
912 static int irttp_data_indication(void *instance, void *sap,
913 struct sk_buff *skb)
914 {
915 struct tsap_cb *self;
916 unsigned long flags;
917 int n;
918
919 self = instance;
920
921 n = skb->data[0] & 0x7f; /* Extract the credits */
922
923 self->stats.rx_packets++;
924
925 /* Deal with inbound credit
926 * Since we can transmit and receive frames concurrently,
927 * the code below is a critical region and we must assure that
928 * nobody messes with the credits while we update them.
929 */
930 spin_lock_irqsave(&self->lock, flags);
931 self->send_credit += n;
932 if (skb->len > 1)
933 self->remote_credit--;
934 spin_unlock_irqrestore(&self->lock, flags);
935
936 /*
937 * Data or dataless packet? Dataless frames contains only the
938 * TTP_HEADER.
939 */
940 if (skb->len > 1) {
941 /*
942 * We don't remove the TTP header, since we must preserve the
943 * more bit, so the defragment routing knows what to do
944 */
945 skb_queue_tail(&self->rx_queue, skb);
946 } else {
947 /* Dataless flowdata TTP-PDU */
948 dev_kfree_skb(skb);
949 }
950
951
952 /* Push data to the higher layer.
953 * We do it synchronously because running the todo timer for each
954 * receive packet would be too much overhead and latency.
955 * By passing control to the higher layer, we run the risk that
956 * it may take time or grab a lock. Most often, the higher layer
957 * will only put packet in a queue.
958 * Anyway, packets are only dripping through the IrDA, so we can
959 * have time before the next packet.
960 * Further, we are run from NET_BH, so the worse that can happen is
961 * us missing the optimal time to send back the PF bit in LAP.
962 * Jean II */
963 irttp_run_rx_queue(self);
964
965 /* We now give credits to peer in irttp_run_rx_queue().
966 * We need to send credit *NOW*, otherwise we are going
967 * to miss the next Tx window. The todo timer may take
968 * a while before it's run... - Jean II */
969
970 /*
971 * If the peer device has given us some credits and we didn't have
972 * anyone from before, then we need to shedule the tx queue.
973 * We need to do that because our Tx have stopped (so we may not
974 * get any LAP flow indication) and the user may be stopped as
975 * well. - Jean II
976 */
977 if (self->send_credit == n) {
978 /* Restart pushing stuff to LAP */
979 irttp_run_tx_queue(self);
980 /* Note : we don't want to schedule the todo timer
981 * because it has horrible latency. No tasklets
982 * because the tasklet API is broken. - Jean II */
983 }
984
985 return 0;
986 }
987
988 /*
989 * Function irttp_status_indication (self, reason)
990 *
991 * Status_indication, just pass to the higher layer...
992 *
993 */
994 static void irttp_status_indication(void *instance,
995 LINK_STATUS link, LOCK_STATUS lock)
996 {
997 struct tsap_cb *self;
998
999 IRDA_DEBUG(4, "%s()\n", __func__);
1000
1001 self = instance;
1002
1003 IRDA_ASSERT(self != NULL, return;);
1004 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1005
1006 /* Check if client has already closed the TSAP and gone away */
1007 if (self->close_pend)
1008 return;
1009
1010 /*
1011 * Inform service user if he has requested it
1012 */
1013 if (self->notify.status_indication != NULL)
1014 self->notify.status_indication(self->notify.instance,
1015 link, lock);
1016 else
1017 IRDA_DEBUG(2, "%s(), no handler\n", __func__);
1018 }
1019
1020 /*
1021 * Function irttp_flow_indication (self, reason)
1022 *
1023 * Flow_indication : IrLAP tells us to send more data.
1024 *
1025 */
1026 static void irttp_flow_indication(void *instance, void *sap, LOCAL_FLOW flow)
1027 {
1028 struct tsap_cb *self;
1029
1030 self = instance;
1031
1032 IRDA_ASSERT(self != NULL, return;);
1033 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1034
1035 IRDA_DEBUG(4, "%s(instance=%p)\n", __func__, self);
1036
1037 /* We are "polled" directly from LAP, and the LAP want to fill
1038 * its Tx window. We want to do our best to send it data, so that
1039 * we maximise the window. On the other hand, we want to limit the
1040 * amount of work here so that LAP doesn't hang forever waiting
1041 * for packets. - Jean II */
1042
1043 /* Try to send some packets. Currently, LAP calls us every time
1044 * there is one free slot, so we will send only one packet.
1045 * This allow the scheduler to do its round robin - Jean II */
1046 irttp_run_tx_queue(self);
1047
1048 /* Note regarding the interraction with higher layer.
1049 * irttp_run_tx_queue() may call the client when its queue
1050 * start to empty, via notify.flow_indication(). Initially.
1051 * I wanted this to happen in a tasklet, to avoid client
1052 * grabbing the CPU, but we can't use tasklets safely. And timer
1053 * is definitely too slow.
1054 * This will happen only once per LAP window, and usually at
1055 * the third packet (unless window is smaller). LAP is still
1056 * doing mtt and sending first packet so it's sort of OK
1057 * to do that. Jean II */
1058
1059 /* If we need to send disconnect. try to do it now */
1060 if(self->disconnect_pend)
1061 irttp_start_todo_timer(self, 0);
1062 }
1063
1064 /*
1065 * Function irttp_flow_request (self, command)
1066 *
1067 * This function could be used by the upper layers to tell IrTTP to stop
1068 * delivering frames if the receive queues are starting to get full, or
1069 * to tell IrTTP to start delivering frames again.
1070 */
1071 void irttp_flow_request(struct tsap_cb *self, LOCAL_FLOW flow)
1072 {
1073 IRDA_DEBUG(1, "%s()\n", __func__);
1074
1075 IRDA_ASSERT(self != NULL, return;);
1076 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1077
1078 switch (flow) {
1079 case FLOW_STOP:
1080 IRDA_DEBUG(1, "%s(), flow stop\n", __func__);
1081 self->rx_sdu_busy = TRUE;
1082 break;
1083 case FLOW_START:
1084 IRDA_DEBUG(1, "%s(), flow start\n", __func__);
1085 self->rx_sdu_busy = FALSE;
1086
1087 /* Client say he can accept more data, try to free our
1088 * queues ASAP - Jean II */
1089 irttp_run_rx_queue(self);
1090
1091 break;
1092 default:
1093 IRDA_DEBUG(1, "%s(), Unknown flow command!\n", __func__);
1094 }
1095 }
1096 EXPORT_SYMBOL(irttp_flow_request);
1097
1098 /*
1099 * Function irttp_connect_request (self, dtsap_sel, daddr, qos)
1100 *
1101 * Try to connect to remote destination TSAP selector
1102 *
1103 */
1104 int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
1105 __u32 saddr, __u32 daddr,
1106 struct qos_info *qos, __u32 max_sdu_size,
1107 struct sk_buff *userdata)
1108 {
1109 struct sk_buff *tx_skb;
1110 __u8 *frame;
1111 __u8 n;
1112
1113 IRDA_DEBUG(4, "%s(), max_sdu_size=%d\n", __func__, max_sdu_size);
1114
1115 IRDA_ASSERT(self != NULL, return -EBADR;);
1116 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -EBADR;);
1117
1118 if (self->connected) {
1119 if(userdata)
1120 dev_kfree_skb(userdata);
1121 return -EISCONN;
1122 }
1123
1124 /* Any userdata supplied? */
1125 if (userdata == NULL) {
1126 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1127 GFP_ATOMIC);
1128 if (!tx_skb)
1129 return -ENOMEM;
1130
1131 /* Reserve space for MUX_CONTROL and LAP header */
1132 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1133 } else {
1134 tx_skb = userdata;
1135 /*
1136 * Check that the client has reserved enough space for
1137 * headers
1138 */
1139 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1140 { dev_kfree_skb(userdata); return -1; } );
1141 }
1142
1143 /* Initialize connection parameters */
1144 self->connected = FALSE;
1145 self->avail_credit = 0;
1146 self->rx_max_sdu_size = max_sdu_size;
1147 self->rx_sdu_size = 0;
1148 self->rx_sdu_busy = FALSE;
1149 self->dtsap_sel = dtsap_sel;
1150
1151 n = self->initial_credit;
1152
1153 self->remote_credit = 0;
1154 self->send_credit = 0;
1155
1156 /*
1157 * Give away max 127 credits for now
1158 */
1159 if (n > 127) {
1160 self->avail_credit=n-127;
1161 n = 127;
1162 }
1163
1164 self->remote_credit = n;
1165
1166 /* SAR enabled? */
1167 if (max_sdu_size > 0) {
1168 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1169 { dev_kfree_skb(tx_skb); return -1; } );
1170
1171 /* Insert SAR parameters */
1172 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1173
1174 frame[0] = TTP_PARAMETERS | n;
1175 frame[1] = 0x04; /* Length */
1176 frame[2] = 0x01; /* MaxSduSize */
1177 frame[3] = 0x02; /* Value length */
1178
1179 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1180 (__be16 *)(frame+4));
1181 } else {
1182 /* Insert plain TTP header */
1183 frame = skb_push(tx_skb, TTP_HEADER);
1184
1185 /* Insert initial credit in frame */
1186 frame[0] = n & 0x7f;
1187 }
1188
1189 /* Connect with IrLMP. No QoS parameters for now */
1190 return irlmp_connect_request(self->lsap, dtsap_sel, saddr, daddr, qos,
1191 tx_skb);
1192 }
1193 EXPORT_SYMBOL(irttp_connect_request);
1194
1195 /*
1196 * Function irttp_connect_confirm (handle, qos, skb)
1197 *
1198 * Service user confirms TSAP connection with peer.
1199 *
1200 */
1201 static void irttp_connect_confirm(void *instance, void *sap,
1202 struct qos_info *qos, __u32 max_seg_size,
1203 __u8 max_header_size, struct sk_buff *skb)
1204 {
1205 struct tsap_cb *self;
1206 int parameters;
1207 int ret;
1208 __u8 plen;
1209 __u8 n;
1210
1211 IRDA_DEBUG(4, "%s()\n", __func__);
1212
1213 self = instance;
1214
1215 IRDA_ASSERT(self != NULL, return;);
1216 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1217 IRDA_ASSERT(skb != NULL, return;);
1218
1219 self->max_seg_size = max_seg_size - TTP_HEADER;
1220 self->max_header_size = max_header_size + TTP_HEADER;
1221
1222 /*
1223 * Check if we have got some QoS parameters back! This should be the
1224 * negotiated QoS for the link.
1225 */
1226 if (qos) {
1227 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %02x\n",
1228 qos->baud_rate.bits);
1229 IRDA_DEBUG(4, "IrTTP, Negotiated BAUD_RATE: %d bps.\n",
1230 qos->baud_rate.value);
1231 }
1232
1233 n = skb->data[0] & 0x7f;
1234
1235 IRDA_DEBUG(4, "%s(), Initial send_credit=%d\n", __func__, n);
1236
1237 self->send_credit = n;
1238 self->tx_max_sdu_size = 0;
1239 self->connected = TRUE;
1240
1241 parameters = skb->data[0] & 0x80;
1242
1243 IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1244 skb_pull(skb, TTP_HEADER);
1245
1246 if (parameters) {
1247 plen = skb->data[0];
1248
1249 ret = irda_param_extract_all(self, skb->data+1,
1250 IRDA_MIN(skb->len-1, plen),
1251 ¶m_info);
1252
1253 /* Any errors in the parameter list? */
1254 if (ret < 0) {
1255 IRDA_WARNING("%s: error extracting parameters\n",
1256 __func__);
1257 dev_kfree_skb(skb);
1258
1259 /* Do not accept this connection attempt */
1260 return;
1261 }
1262 /* Remove parameters */
1263 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1264 }
1265
1266 IRDA_DEBUG(4, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1267 self->send_credit, self->avail_credit, self->remote_credit);
1268
1269 IRDA_DEBUG(2, "%s(), MaxSduSize=%d\n", __func__,
1270 self->tx_max_sdu_size);
1271
1272 if (self->notify.connect_confirm) {
1273 self->notify.connect_confirm(self->notify.instance, self, qos,
1274 self->tx_max_sdu_size,
1275 self->max_header_size, skb);
1276 } else
1277 dev_kfree_skb(skb);
1278 }
1279
1280 /*
1281 * Function irttp_connect_indication (handle, skb)
1282 *
1283 * Some other device is connecting to this TSAP
1284 *
1285 */
1286 static void irttp_connect_indication(void *instance, void *sap,
1287 struct qos_info *qos, __u32 max_seg_size, __u8 max_header_size,
1288 struct sk_buff *skb)
1289 {
1290 struct tsap_cb *self;
1291 struct lsap_cb *lsap;
1292 int parameters;
1293 int ret;
1294 __u8 plen;
1295 __u8 n;
1296
1297 self = instance;
1298
1299 IRDA_ASSERT(self != NULL, return;);
1300 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1301 IRDA_ASSERT(skb != NULL, return;);
1302
1303 lsap = sap;
1304
1305 self->max_seg_size = max_seg_size - TTP_HEADER;
1306 self->max_header_size = max_header_size+TTP_HEADER;
1307
1308 IRDA_DEBUG(4, "%s(), TSAP sel=%02x\n", __func__, self->stsap_sel);
1309
1310 /* Need to update dtsap_sel if its equal to LSAP_ANY */
1311 self->dtsap_sel = lsap->dlsap_sel;
1312
1313 n = skb->data[0] & 0x7f;
1314
1315 self->send_credit = n;
1316 self->tx_max_sdu_size = 0;
1317
1318 parameters = skb->data[0] & 0x80;
1319
1320 IRDA_ASSERT(skb->len >= TTP_HEADER, return;);
1321 skb_pull(skb, TTP_HEADER);
1322
1323 if (parameters) {
1324 plen = skb->data[0];
1325
1326 ret = irda_param_extract_all(self, skb->data+1,
1327 IRDA_MIN(skb->len-1, plen),
1328 ¶m_info);
1329
1330 /* Any errors in the parameter list? */
1331 if (ret < 0) {
1332 IRDA_WARNING("%s: error extracting parameters\n",
1333 __func__);
1334 dev_kfree_skb(skb);
1335
1336 /* Do not accept this connection attempt */
1337 return;
1338 }
1339
1340 /* Remove parameters */
1341 skb_pull(skb, IRDA_MIN(skb->len, plen+1));
1342 }
1343
1344 if (self->notify.connect_indication) {
1345 self->notify.connect_indication(self->notify.instance, self,
1346 qos, self->tx_max_sdu_size,
1347 self->max_header_size, skb);
1348 } else
1349 dev_kfree_skb(skb);
1350 }
1351
1352 /*
1353 * Function irttp_connect_response (handle, userdata)
1354 *
1355 * Service user is accepting the connection, just pass it down to
1356 * IrLMP!
1357 *
1358 */
1359 int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
1360 struct sk_buff *userdata)
1361 {
1362 struct sk_buff *tx_skb;
1363 __u8 *frame;
1364 int ret;
1365 __u8 n;
1366
1367 IRDA_ASSERT(self != NULL, return -1;);
1368 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1369
1370 IRDA_DEBUG(4, "%s(), Source TSAP selector=%02x\n", __func__,
1371 self->stsap_sel);
1372
1373 /* Any userdata supplied? */
1374 if (userdata == NULL) {
1375 tx_skb = alloc_skb(TTP_MAX_HEADER + TTP_SAR_HEADER,
1376 GFP_ATOMIC);
1377 if (!tx_skb)
1378 return -ENOMEM;
1379
1380 /* Reserve space for MUX_CONTROL and LAP header */
1381 skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
1382 } else {
1383 tx_skb = userdata;
1384 /*
1385 * Check that the client has reserved enough space for
1386 * headers
1387 */
1388 IRDA_ASSERT(skb_headroom(userdata) >= TTP_MAX_HEADER,
1389 { dev_kfree_skb(userdata); return -1; } );
1390 }
1391
1392 self->avail_credit = 0;
1393 self->remote_credit = 0;
1394 self->rx_max_sdu_size = max_sdu_size;
1395 self->rx_sdu_size = 0;
1396 self->rx_sdu_busy = FALSE;
1397
1398 n = self->initial_credit;
1399
1400 /* Frame has only space for max 127 credits (7 bits) */
1401 if (n > 127) {
1402 self->avail_credit = n - 127;
1403 n = 127;
1404 }
1405
1406 self->remote_credit = n;
1407 self->connected = TRUE;
1408
1409 /* SAR enabled? */
1410 if (max_sdu_size > 0) {
1411 IRDA_ASSERT(skb_headroom(tx_skb) >= (TTP_MAX_HEADER + TTP_SAR_HEADER),
1412 { dev_kfree_skb(tx_skb); return -1; } );
1413
1414 /* Insert TTP header with SAR parameters */
1415 frame = skb_push(tx_skb, TTP_HEADER+TTP_SAR_HEADER);
1416
1417 frame[0] = TTP_PARAMETERS | n;
1418 frame[1] = 0x04; /* Length */
1419
1420 /* irda_param_insert(self, IRTTP_MAX_SDU_SIZE, frame+1, */
1421 /* TTP_SAR_HEADER, ¶m_info) */
1422
1423 frame[2] = 0x01; /* MaxSduSize */
1424 frame[3] = 0x02; /* Value length */
1425
1426 put_unaligned(cpu_to_be16((__u16) max_sdu_size),
1427 (__be16 *)(frame+4));
1428 } else {
1429 /* Insert TTP header */
1430 frame = skb_push(tx_skb, TTP_HEADER);
1431
1432 frame[0] = n & 0x7f;
1433 }
1434
1435 ret = irlmp_connect_response(self->lsap, tx_skb);
1436
1437 return ret;
1438 }
1439 EXPORT_SYMBOL(irttp_connect_response);
1440
1441 /*
1442 * Function irttp_dup (self, instance)
1443 *
1444 * Duplicate TSAP, can be used by servers to confirm a connection on a
1445 * new TSAP so it can keep listening on the old one.
1446 */
1447 struct tsap_cb *irttp_dup(struct tsap_cb *orig, void *instance)
1448 {
1449 struct tsap_cb *new;
1450 unsigned long flags;
1451
1452 IRDA_DEBUG(1, "%s()\n", __func__);
1453
1454 /* Protect our access to the old tsap instance */
1455 spin_lock_irqsave(&irttp->tsaps->hb_spinlock, flags);
1456
1457 /* Find the old instance */
1458 if (!hashbin_find(irttp->tsaps, (long) orig, NULL)) {
1459 IRDA_DEBUG(0, "%s(), unable to find TSAP\n", __func__);
1460 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1461 return NULL;
1462 }
1463
1464 /* Allocate a new instance */
1465 new = kmemdup(orig, sizeof(struct tsap_cb), GFP_ATOMIC);
1466 if (!new) {
1467 IRDA_DEBUG(0, "%s(), unable to kmalloc\n", __func__);
1468 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1469 return NULL;
1470 }
1471 spin_lock_init(&new->lock);
1472
1473 /* We don't need the old instance any more */
1474 spin_unlock_irqrestore(&irttp->tsaps->hb_spinlock, flags);
1475
1476 /* Try to dup the LSAP (may fail if we were too slow) */
1477 new->lsap = irlmp_dup(orig->lsap, new);
1478 if (!new->lsap) {
1479 IRDA_DEBUG(0, "%s(), dup failed!\n", __func__);
1480 kfree(new);
1481 return NULL;
1482 }
1483
1484 /* Not everything should be copied */
1485 new->notify.instance = instance;
1486
1487 /* Initialize internal objects */
1488 irttp_init_tsap(new);
1489
1490 /* This is locked */
1491 hashbin_insert(irttp->tsaps, (irda_queue_t *) new, (long) new, NULL);
1492
1493 return new;
1494 }
1495 EXPORT_SYMBOL(irttp_dup);
1496
1497 /*
1498 * Function irttp_disconnect_request (self)
1499 *
1500 * Close this connection please! If priority is high, the queued data
1501 * segments, if any, will be deallocated first
1502 *
1503 */
1504 int irttp_disconnect_request(struct tsap_cb *self, struct sk_buff *userdata,
1505 int priority)
1506 {
1507 int ret;
1508
1509 IRDA_ASSERT(self != NULL, return -1;);
1510 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return -1;);
1511
1512 /* Already disconnected? */
1513 if (!self->connected) {
1514 IRDA_DEBUG(4, "%s(), already disconnected!\n", __func__);
1515 if (userdata)
1516 dev_kfree_skb(userdata);
1517 return -1;
1518 }
1519
1520 /* Disconnect already pending ?
1521 * We need to use an atomic operation to prevent reentry. This
1522 * function may be called from various context, like user, timer
1523 * for following a disconnect_indication() (i.e. net_bh).
1524 * Jean II */
1525 if(test_and_set_bit(0, &self->disconnect_pend)) {
1526 IRDA_DEBUG(0, "%s(), disconnect already pending\n",
1527 __func__);
1528 if (userdata)
1529 dev_kfree_skb(userdata);
1530
1531 /* Try to make some progress */
1532 irttp_run_tx_queue(self);
1533 return -1;
1534 }
1535
1536 /*
1537 * Check if there is still data segments in the transmit queue
1538 */
1539 if (!skb_queue_empty(&self->tx_queue)) {
1540 if (priority == P_HIGH) {
1541 /*
1542 * No need to send the queued data, if we are
1543 * disconnecting right now since the data will
1544 * not have any usable connection to be sent on
1545 */
1546 IRDA_DEBUG(1, "%s(): High priority!!()\n", __func__);
1547 irttp_flush_queues(self);
1548 } else if (priority == P_NORMAL) {
1549 /*
1550 * Must delay disconnect until after all data segments
1551 * have been sent and the tx_queue is empty
1552 */
1553 /* We'll reuse this one later for the disconnect */
1554 self->disconnect_skb = userdata; /* May be NULL */
1555
1556 irttp_run_tx_queue(self);
1557
1558 irttp_start_todo_timer(self, HZ/10);
1559 return -1;
1560 }
1561 }
1562 /* Note : we don't need to check if self->rx_queue is full and the
1563 * state of self->rx_sdu_busy because the disconnect response will
1564 * be sent at the LMP level (so even if the peer has its Tx queue
1565 * full of data). - Jean II */
1566
1567 IRDA_DEBUG(1, "%s(), Disconnecting ...\n", __func__);
1568 self->connected = FALSE;
1569
1570 if (!userdata) {
1571 struct sk_buff *tx_skb;
1572 tx_skb = alloc_skb(LMP_MAX_HEADER, GFP_ATOMIC);
1573 if (!tx_skb)
1574 return -ENOMEM;
1575
1576 /*
1577 * Reserve space for MUX and LAP header
1578 */
1579 skb_reserve(tx_skb, LMP_MAX_HEADER);
1580
1581 userdata = tx_skb;
1582 }
1583 ret = irlmp_disconnect_request(self->lsap, userdata);
1584
1585 /* The disconnect is no longer pending */
1586 clear_bit(0, &self->disconnect_pend); /* FALSE */
1587
1588 return ret;
1589 }
1590 EXPORT_SYMBOL(irttp_disconnect_request);
1591
1592 /*
1593 * Function irttp_disconnect_indication (self, reason)
1594 *
1595 * Disconnect indication, TSAP disconnected by peer?
1596 *
1597 */
1598 static void irttp_disconnect_indication(void *instance, void *sap,
1599 LM_REASON reason, struct sk_buff *skb)
1600 {
1601 struct tsap_cb *self;
1602
1603 IRDA_DEBUG(4, "%s()\n", __func__);
1604
1605 self = instance;
1606
1607 IRDA_ASSERT(self != NULL, return;);
1608 IRDA_ASSERT(self->magic == TTP_TSAP_MAGIC, return;);
1609
1610 /* Prevent higher layer to send more data */
1611 self->connected = FALSE;
1612
1613 /* Check if client has already tried to close the TSAP */
1614 if (self->close_pend) {
1615 /* In this case, the higher layer is probably gone. Don't
1616 * bother it and clean up the remains - Jean II */
1617 if (skb)
1618 dev_kfree_skb(skb);
1619 irttp_close_tsap(self);
1620 return;
1621 }
1622
1623 /* If we are here, we assume that is the higher layer is still
1624 * waiting for the disconnect notification and able to process it,
1625 * even if he tried to disconnect. Otherwise, it would have already
1626 * attempted to close the tsap and self->close_pend would be TRUE.
1627 * Jean II */
1628
1629 /* No need to notify the client if has already tried to disconnect */
1630 if(self->notify.disconnect_indication)
1631 self->notify.disconnect_indication(self->notify.instance, self,
1632 reason, skb);
1633 else
1634 if (skb)
1635 dev_kfree_skb(skb);
1636 }
1637
1638 /*
1639 * Function irttp_do_data_indication (self, skb)
1640 *
1641 * Try to deliver reassembled skb to layer above, and requeue it if that
1642 * for some reason should fail. We mark rx sdu as busy to apply back
1643 * pressure is necessary.
1644 */
1645 static void irttp_do_data_indication(struct tsap_cb *self, struct sk_buff *skb)
1646 {
1647 int err;
1648
1649 /* Check if client has already closed the TSAP and gone away */
1650 if (self->close_pend) {
1651 dev_kfree_skb(skb);
1652 return;
1653 }
1654
1655 err = self->notify.data_indication(self->notify.instance, self, skb);
1656
1657 /* Usually the layer above will notify that it's input queue is
1658 * starting to get filled by using the flow request, but this may
1659 * be difficult, so it can instead just refuse to eat it and just
1660 * give an error back
1661 */
1662 if (err) {
1663 IRDA_DEBUG(0, "%s() requeueing skb!\n", __func__);
1664
1665 /* Make sure we take a break */
1666 self->rx_sdu_busy = TRUE;
1667
1668 /* Need to push the header in again */
1669 skb_push(skb, TTP_HEADER);
1670 skb->data[0] = 0x00; /* Make sure MORE bit is cleared */
1671
1672 /* Put skb back on queue */
1673 skb_queue_head(&self->rx_queue, skb);
1674 }
1675 }
1676
1677 /*
1678 * Function irttp_run_rx_queue (self)
1679 *
1680 * Check if we have any frames to be transmitted, or if we have any
1681 * available credit to give away.
1682 */
1683 static void irttp_run_rx_queue(struct tsap_cb *self)
1684 {
1685 struct sk_buff *skb;
1686 int more = 0;
1687
1688 IRDA_DEBUG(2, "%s() send=%d,avail=%d,remote=%d\n", __func__,
1689 self->send_credit, self->avail_credit, self->remote_credit);
1690
1691 /* Get exclusive access to the rx queue, otherwise don't touch it */
1692 if (irda_lock(&self->rx_queue_lock) == FALSE)
1693 return;
1694
1695 /*
1696 * Reassemble all frames in receive queue and deliver them
1697 */
1698 while (!self->rx_sdu_busy && (skb = skb_dequeue(&self->rx_queue))) {
1699 /* This bit will tell us if it's the last fragment or not */
1700 more = skb->data[0] & 0x80;
1701
1702 /* Remove TTP header */
1703 skb_pull(skb, TTP_HEADER);
1704
1705 /* Add the length of the remaining data */
1706 self->rx_sdu_size += skb->len;
1707
1708 /*
1709 * If SAR is disabled, or user has requested no reassembly
1710 * of received fragments then we just deliver them
1711 * immediately. This can be requested by clients that
1712 * implements byte streams without any message boundaries
1713 */
1714 if (self->rx_max_sdu_size == TTP_SAR_DISABLE) {
1715 irttp_do_data_indication(self, skb);
1716 self->rx_sdu_size = 0;
1717
1718 continue;
1719 }
1720
1721 /* Check if this is a fragment, and not the last fragment */
1722 if (more) {
1723 /*
1724 * Queue the fragment if we still are within the
1725 * limits of the maximum size of the rx_sdu
1726 */
1727 if (self->rx_sdu_size <= self->rx_max_sdu_size) {
1728 IRDA_DEBUG(4, "%s(), queueing frag\n",
1729 __func__);
1730 skb_queue_tail(&self->rx_fragments, skb);
1731 } else {
1732 /* Free the part of the SDU that is too big */
1733 dev_kfree_skb(skb);
1734 }
1735 continue;
1736 }
1737 /*
1738 * This is the last fragment, so time to reassemble!
1739 */
1740 if ((self->rx_sdu_size <= self->rx_max_sdu_size) ||
1741 (self->rx_max_sdu_size == TTP_SAR_UNBOUND))
1742 {
1743 /*
1744 * A little optimizing. Only queue the fragment if
1745 * there are other fragments. Since if this is the
1746 * last and only fragment, there is no need to
1747 * reassemble :-)
1748 */
1749 if (!skb_queue_empty(&self->rx_fragments)) {
1750 skb_queue_tail(&self->rx_fragments,
1751 skb);
1752
1753 skb = irttp_reassemble_skb(self);
1754 }
1755
1756 /* Now we can deliver the reassembled skb */
1757 irttp_do_data_indication(self, skb);
1758 } else {
1759 IRDA_DEBUG(1, "%s(), Truncated frame\n", __func__);
1760
1761 /* Free the part of the SDU that is too big */
1762 dev_kfree_skb(skb);
1763
1764 /* Deliver only the valid but truncated part of SDU */
1765 skb = irttp_reassemble_skb(self);
1766
1767 irttp_do_data_indication(self, skb);
1768 }
1769 self->rx_sdu_size = 0;
1770 }
1771
1772 /*
1773 * It's not trivial to keep track of how many credits are available
1774 * by incrementing at each packet, because delivery may fail
1775 * (irttp_do_data_indication() may requeue the frame) and because
1776 * we need to take care of fragmentation.
1777 * We want the other side to send up to initial_credit packets.
1778 * We have some frames in our queues, and we have already allowed it
1779 * to send remote_credit.
1780 * No need to spinlock, write is atomic and self correcting...
1781 * Jean II
1782 */
1783 self->avail_credit = (self->initial_credit -
1784 (self->remote_credit +
1785 skb_queue_len(&self->rx_queue) +
1786 skb_queue_len(&self->rx_fragments)));
1787
1788 /* Do we have too much credits to send to peer ? */
1789 if ((self->remote_credit <= TTP_RX_MIN_CREDIT) &&
1790 (self->avail_credit > 0)) {
1791 /* Send explicit credit frame */
1792 irttp_give_credit(self);
1793 /* Note : do *NOT* check if tx_queue is non-empty, that
1794 * will produce deadlocks. I repeat : send a credit frame
1795 * even if we have something to send in our Tx queue.
1796 * If we have credits, it means that our Tx queue is blocked.
1797 *
1798 * Let's suppose the peer can't keep up with our Tx. He will
1799 * flow control us by not sending us any credits, and we
1800 * will stop Tx and start accumulating credits here.
1801 * Up to the point where the peer will stop its Tx queue,
1802 * for lack of credits.
1803 * Let's assume the peer application is single threaded.
1804 * It will block on Tx and never consume any Rx buffer.
1805 * Deadlock. Guaranteed. - Jean II
1806 */
1807 }
1808
1809 /* Reset lock */
1810 self->rx_queue_lock = 0;
1811 }
1812
1813 #ifdef CONFIG_PROC_FS
1814 struct irttp_iter_state {
1815 int id;
1816 };
1817
1818 static void *irttp_seq_start(struct seq_file *seq, loff_t *pos)
1819 {
1820 struct irttp_iter_state *iter = seq->private;
1821 struct tsap_cb *self;
1822
1823 /* Protect our access to the tsap list */
1824 spin_lock_irq(&irttp->tsaps->hb_spinlock);
1825 iter->id = 0;
1826
1827 for (self = (struct tsap_cb *) hashbin_get_first(irttp->tsaps);
1828 self != NULL;
1829 self = (struct tsap_cb *) hashbin_get_next(irttp->tsaps)) {
1830 if (iter->id == *pos)
1831 break;
1832 ++iter->id;
1833 }
1834
1835 return self;
1836 }
1837
1838 static void *irttp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1839 {
1840 struct irttp_iter_state *iter = seq->private;
1841
1842 ++*pos;
1843 ++iter->id;
1844 return (void *) hashbin_get_next(irttp->tsaps);
1845 }
1846
1847 static void irttp_seq_stop(struct seq_file *seq, void *v)
1848 {
1849 spin_unlock_irq(&irttp->tsaps->hb_spinlock);
1850 }
1851
1852 static int irttp_seq_show(struct seq_file *seq, void *v)
1853 {
1854 const struct irttp_iter_state *iter = seq->private;
1855 const struct tsap_cb *self = v;
1856
1857 seq_printf(seq, "TSAP %d, ", iter->id);
1858 seq_printf(seq, "stsap_sel: %02x, ",
1859 self->stsap_sel);
1860 seq_printf(seq, "dtsap_sel: %02x\n",
1861 self->dtsap_sel);
1862 seq_printf(seq, " connected: %s, ",
1863 self->connected? "TRUE":"FALSE");
1864 seq_printf(seq, "avail credit: %d, ",
1865 self->avail_credit);
1866 seq_printf(seq, "remote credit: %d, ",
1867 self->remote_credit);
1868 seq_printf(seq, "send credit: %d\n",
1869 self->send_credit);
1870 seq_printf(seq, " tx packets: %lu, ",
1871 self->stats.tx_packets);
1872 seq_printf(seq, "rx packets: %lu, ",
1873 self->stats.rx_packets);
1874 seq_printf(seq, "tx_queue len: %u ",
1875 skb_queue_len(&self->tx_queue));
1876 seq_printf(seq, "rx_queue len: %u\n",
1877 skb_queue_len(&self->rx_queue));
1878 seq_printf(seq, " tx_sdu_busy: %s, ",
1879 self->tx_sdu_busy? "TRUE":"FALSE");
1880 seq_printf(seq, "rx_sdu_busy: %s\n",
1881 self->rx_sdu_busy? "TRUE":"FALSE");
1882 seq_printf(seq, " max_seg_size: %u, ",
1883 self->max_seg_size);
1884 seq_printf(seq, "tx_max_sdu_size: %u, ",
1885 self->tx_max_sdu_size);
1886 seq_printf(seq, "rx_max_sdu_size: %u\n",
1887 self->rx_max_sdu_size);
1888
1889 seq_printf(seq, " Used by (%s)\n\n",
1890 self->notify.name);
1891 return 0;
1892 }
1893
1894 static const struct seq_operations irttp_seq_ops = {
1895 .start = irttp_seq_start,
1896 .next = irttp_seq_next,
1897 .stop = irttp_seq_stop,
1898 .show = irttp_seq_show,
1899 };
1900
1901 static int irttp_seq_open(struct inode *inode, struct file *file)
1902 {
1903 return seq_open_private(file, &irttp_seq_ops,
1904 sizeof(struct irttp_iter_state));
1905 }
1906
1907 const struct file_operations irttp_seq_fops = {
1908 .owner = THIS_MODULE,
1909 .open = irttp_seq_open,
1910 .read = seq_read,
1911 .llseek = seq_lseek,
1912 .release = seq_release_private,
1913 };
1914
1915 #endif /* PROC_FS */
1916
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