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1/*********************************************************************
2 *
3 * Filename: irlap_frame.c
4 * Version: 1.0
5 * Description: Build and transmit IrLAP frames
6 * Status: Stable
7 * Author: Dag Brattli <dagb@cs.uit.no>
8 * Created at: Tue Aug 19 10:27:26 1997
9 * Modified at: Wed Jan 5 08:59:04 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/if.h>
29#include <linux/if_ether.h>
30#include <linux/netdevice.h>
31#include <linux/irda.h>
32#include <linux/slab.h>
33
34#include <net/pkt_sched.h>
35#include <net/sock.h>
36
37#include <asm/byteorder.h>
38
39#include <net/irda/irda.h>
40#include <net/irda/irda_device.h>
41#include <net/irda/irlap.h>
42#include <net/irda/wrapper.h>
43#include <net/irda/timer.h>
44#include <net/irda/irlap_frame.h>
45#include <net/irda/qos.h>
46
47static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
48 int command);
49
50/*
51 * Function irlap_insert_info (self, skb)
52 *
53 * Insert minimum turnaround time and speed information into the skb. We
54 * need to do this since it's per packet relevant information. Safe to
55 * have this function inlined since it's only called from one place
56 */
57static inline void irlap_insert_info(struct irlap_cb *self,
58 struct sk_buff *skb)
59{
60 struct irda_skb_cb *cb = (struct irda_skb_cb *) skb->cb;
61
62 /*
63 * Insert MTT (min. turn time) and speed into skb, so that the
64 * device driver knows which settings to use
65 */
66 cb->magic = LAP_MAGIC;
67 cb->mtt = self->mtt_required;
68 cb->next_speed = self->speed;
69
70 /* Reset */
71 self->mtt_required = 0;
72
73 /*
74 * Delay equals negotiated BOFs count, plus the number of BOFs to
75 * force the negotiated minimum turnaround time
76 */
77 cb->xbofs = self->bofs_count;
78 cb->next_xbofs = self->next_bofs;
79 cb->xbofs_delay = self->xbofs_delay;
80
81 /* Reset XBOF's delay (used only for getting min turn time) */
82 self->xbofs_delay = 0;
83 /* Put the correct xbofs value for the next packet */
84 self->bofs_count = self->next_bofs;
85}
86
87/*
88 * Function irlap_queue_xmit (self, skb)
89 *
90 * A little wrapper for dev_queue_xmit, so we can insert some common
91 * code into it.
92 */
93void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb)
94{
95 /* Some common init stuff */
96 skb->dev = self->netdev;
97 skb_reset_mac_header(skb);
98 skb_reset_network_header(skb);
99 skb_reset_transport_header(skb);
100 skb->protocol = htons(ETH_P_IRDA);
101 skb->priority = TC_PRIO_BESTEFFORT;
102
103 irlap_insert_info(self, skb);
104
105 if (unlikely(self->mode & IRDA_MODE_MONITOR)) {
106 IRDA_DEBUG(3, "%s(): %s is in monitor mode\n", __func__,
107 self->netdev->name);
108 dev_kfree_skb(skb);
109 return;
110 }
111
112 dev_queue_xmit(skb);
113}
114
115/*
116 * Function irlap_send_snrm_cmd (void)
117 *
118 * Transmits a connect SNRM command frame
119 */
120void irlap_send_snrm_frame(struct irlap_cb *self, struct qos_info *qos)
121{
122 struct sk_buff *tx_skb;
123 struct snrm_frame *frame;
124 int ret;
125
126 IRDA_ASSERT(self != NULL, return;);
127 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
128
129 /* Allocate frame */
130 tx_skb = alloc_skb(sizeof(struct snrm_frame) +
131 IRLAP_NEGOCIATION_PARAMS_LEN,
132 GFP_ATOMIC);
133 if (!tx_skb)
134 return;
135
136 frame = (struct snrm_frame *) skb_put(tx_skb, 2);
137
138 /* Insert connection address field */
139 if (qos)
140 frame->caddr = CMD_FRAME | CBROADCAST;
141 else
142 frame->caddr = CMD_FRAME | self->caddr;
143
144 /* Insert control field */
145 frame->control = SNRM_CMD | PF_BIT;
146
147 /*
148 * If we are establishing a connection then insert QoS parameters
149 */
150 if (qos) {
151 skb_put(tx_skb, 9); /* 25 left */
152 frame->saddr = cpu_to_le32(self->saddr);
153 frame->daddr = cpu_to_le32(self->daddr);
154
155 frame->ncaddr = self->caddr;
156
157 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
158 if (ret < 0) {
159 dev_kfree_skb(tx_skb);
160 return;
161 }
162 }
163 irlap_queue_xmit(self, tx_skb);
164}
165
166/*
167 * Function irlap_recv_snrm_cmd (skb, info)
168 *
169 * Received SNRM (Set Normal Response Mode) command frame
170 *
171 */
172static void irlap_recv_snrm_cmd(struct irlap_cb *self, struct sk_buff *skb,
173 struct irlap_info *info)
174{
175 struct snrm_frame *frame;
176
177 if (pskb_may_pull(skb,sizeof(struct snrm_frame))) {
178 frame = (struct snrm_frame *) skb->data;
179
180 /* Copy the new connection address ignoring the C/R bit */
181 info->caddr = frame->ncaddr & 0xFE;
182
183 /* Check if the new connection address is valid */
184 if ((info->caddr == 0x00) || (info->caddr == 0xfe)) {
185 IRDA_DEBUG(3, "%s(), invalid connection address!\n",
186 __func__);
187 return;
188 }
189
190 /* Copy peer device address */
191 info->daddr = le32_to_cpu(frame->saddr);
192 info->saddr = le32_to_cpu(frame->daddr);
193
194 /* Only accept if addressed directly to us */
195 if (info->saddr != self->saddr) {
196 IRDA_DEBUG(2, "%s(), not addressed to us!\n",
197 __func__);
198 return;
199 }
200 irlap_do_event(self, RECV_SNRM_CMD, skb, info);
201 } else {
202 /* Signal that this SNRM frame does not contain and I-field */
203 irlap_do_event(self, RECV_SNRM_CMD, skb, NULL);
204 }
205}
206
207/*
208 * Function irlap_send_ua_response_frame (qos)
209 *
210 * Send UA (Unnumbered Acknowledgement) frame
211 *
212 */
213void irlap_send_ua_response_frame(struct irlap_cb *self, struct qos_info *qos)
214{
215 struct sk_buff *tx_skb;
216 struct ua_frame *frame;
217 int ret;
218
219 IRDA_DEBUG(2, "%s() <%ld>\n", __func__, jiffies);
220
221 IRDA_ASSERT(self != NULL, return;);
222 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
223
224 /* Allocate frame */
225 tx_skb = alloc_skb(sizeof(struct ua_frame) +
226 IRLAP_NEGOCIATION_PARAMS_LEN,
227 GFP_ATOMIC);
228 if (!tx_skb)
229 return;
230
231 frame = (struct ua_frame *) skb_put(tx_skb, 10);
232
233 /* Build UA response */
234 frame->caddr = self->caddr;
235 frame->control = UA_RSP | PF_BIT;
236
237 frame->saddr = cpu_to_le32(self->saddr);
238 frame->daddr = cpu_to_le32(self->daddr);
239
240 /* Should we send QoS negotiation parameters? */
241 if (qos) {
242 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
243 if (ret < 0) {
244 dev_kfree_skb(tx_skb);
245 return;
246 }
247 }
248
249 irlap_queue_xmit(self, tx_skb);
250}
251
252
253/*
254 * Function irlap_send_dm_frame (void)
255 *
256 * Send disconnected mode (DM) frame
257 *
258 */
259void irlap_send_dm_frame( struct irlap_cb *self)
260{
261 struct sk_buff *tx_skb = NULL;
262 struct dm_frame *frame;
263
264 IRDA_ASSERT(self != NULL, return;);
265 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
266
267 tx_skb = alloc_skb(sizeof(struct dm_frame), GFP_ATOMIC);
268 if (!tx_skb)
269 return;
270
271 frame = (struct dm_frame *)skb_put(tx_skb, 2);
272
273 if (self->state == LAP_NDM)
274 frame->caddr = CBROADCAST;
275 else
276 frame->caddr = self->caddr;
277
278 frame->control = DM_RSP | PF_BIT;
279
280 irlap_queue_xmit(self, tx_skb);
281}
282
283/*
284 * Function irlap_send_disc_frame (void)
285 *
286 * Send disconnect (DISC) frame
287 *
288 */
289void irlap_send_disc_frame(struct irlap_cb *self)
290{
291 struct sk_buff *tx_skb = NULL;
292 struct disc_frame *frame;
293
294 IRDA_DEBUG(3, "%s()\n", __func__);
295
296 IRDA_ASSERT(self != NULL, return;);
297 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
298
299 tx_skb = alloc_skb(sizeof(struct disc_frame), GFP_ATOMIC);
300 if (!tx_skb)
301 return;
302
303 frame = (struct disc_frame *)skb_put(tx_skb, 2);
304
305 frame->caddr = self->caddr | CMD_FRAME;
306 frame->control = DISC_CMD | PF_BIT;
307
308 irlap_queue_xmit(self, tx_skb);
309}
310
311/*
312 * Function irlap_send_discovery_xid_frame (S, s, command)
313 *
314 * Build and transmit a XID (eXchange station IDentifier) discovery
315 * frame.
316 */
317void irlap_send_discovery_xid_frame(struct irlap_cb *self, int S, __u8 s,
318 __u8 command, discovery_t *discovery)
319{
320 struct sk_buff *tx_skb = NULL;
321 struct xid_frame *frame;
322 __u32 bcast = BROADCAST;
323 __u8 *info;
324
325 IRDA_DEBUG(4, "%s(), s=%d, S=%d, command=%d\n", __func__,
326 s, S, command);
327
328 IRDA_ASSERT(self != NULL, return;);
329 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
330 IRDA_ASSERT(discovery != NULL, return;);
331
332 tx_skb = alloc_skb(sizeof(struct xid_frame) + IRLAP_DISCOVERY_INFO_LEN,
333 GFP_ATOMIC);
334 if (!tx_skb)
335 return;
336
337 skb_put(tx_skb, 14);
338 frame = (struct xid_frame *) tx_skb->data;
339
340 if (command) {
341 frame->caddr = CBROADCAST | CMD_FRAME;
342 frame->control = XID_CMD | PF_BIT;
343 } else {
344 frame->caddr = CBROADCAST;
345 frame->control = XID_RSP | PF_BIT;
346 }
347 frame->ident = XID_FORMAT;
348
349 frame->saddr = cpu_to_le32(self->saddr);
350
351 if (command)
352 frame->daddr = cpu_to_le32(bcast);
353 else
354 frame->daddr = cpu_to_le32(discovery->data.daddr);
355
356 switch (S) {
357 case 1:
358 frame->flags = 0x00;
359 break;
360 case 6:
361 frame->flags = 0x01;
362 break;
363 case 8:
364 frame->flags = 0x02;
365 break;
366 case 16:
367 frame->flags = 0x03;
368 break;
369 default:
370 frame->flags = 0x02;
371 break;
372 }
373
374 frame->slotnr = s;
375 frame->version = 0x00;
376
377 /*
378 * Provide info for final slot only in commands, and for all
379 * responses. Send the second byte of the hint only if the
380 * EXTENSION bit is set in the first byte.
381 */
382 if (!command || (frame->slotnr == 0xff)) {
383 int len;
384
385 if (discovery->data.hints[0] & HINT_EXTENSION) {
386 info = skb_put(tx_skb, 2);
387 info[0] = discovery->data.hints[0];
388 info[1] = discovery->data.hints[1];
389 } else {
390 info = skb_put(tx_skb, 1);
391 info[0] = discovery->data.hints[0];
392 }
393 info = skb_put(tx_skb, 1);
394 info[0] = discovery->data.charset;
395
396 len = IRDA_MIN(discovery->name_len, skb_tailroom(tx_skb));
397 info = skb_put(tx_skb, len);
398 memcpy(info, discovery->data.info, len);
399 }
400 irlap_queue_xmit(self, tx_skb);
401}
402
403/*
404 * Function irlap_recv_discovery_xid_rsp (skb, info)
405 *
406 * Received a XID discovery response
407 *
408 */
409static void irlap_recv_discovery_xid_rsp(struct irlap_cb *self,
410 struct sk_buff *skb,
411 struct irlap_info *info)
412{
413 struct xid_frame *xid;
414 discovery_t *discovery = NULL;
415 __u8 *discovery_info;
416 char *text;
417
418 IRDA_DEBUG(4, "%s()\n", __func__);
419
420 IRDA_ASSERT(self != NULL, return;);
421 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
422
423 if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
424 IRDA_ERROR("%s: frame too short!\n", __func__);
425 return;
426 }
427
428 xid = (struct xid_frame *) skb->data;
429
430 info->daddr = le32_to_cpu(xid->saddr);
431 info->saddr = le32_to_cpu(xid->daddr);
432
433 /* Make sure frame is addressed to us */
434 if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
435 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
436 __func__);
437 return;
438 }
439
440 if ((discovery = kzalloc(sizeof(discovery_t), GFP_ATOMIC)) == NULL) {
441 IRDA_WARNING("%s: kmalloc failed!\n", __func__);
442 return;
443 }
444
445 discovery->data.daddr = info->daddr;
446 discovery->data.saddr = self->saddr;
447 discovery->timestamp = jiffies;
448
449 IRDA_DEBUG(4, "%s(), daddr=%08x\n", __func__,
450 discovery->data.daddr);
451
452 discovery_info = skb_pull(skb, sizeof(struct xid_frame));
453
454 /* Get info returned from peer */
455 discovery->data.hints[0] = discovery_info[0];
456 if (discovery_info[0] & HINT_EXTENSION) {
457 IRDA_DEBUG(4, "EXTENSION\n");
458 discovery->data.hints[1] = discovery_info[1];
459 discovery->data.charset = discovery_info[2];
460 text = (char *) &discovery_info[3];
461 } else {
462 discovery->data.hints[1] = 0;
463 discovery->data.charset = discovery_info[1];
464 text = (char *) &discovery_info[2];
465 }
466 /*
467 * Terminate info string, should be safe since this is where the
468 * FCS bytes resides.
469 */
470 skb->data[skb->len] = '\0';
471 strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
472 discovery->name_len = strlen(discovery->data.info);
473
474 info->discovery = discovery;
475
476 irlap_do_event(self, RECV_DISCOVERY_XID_RSP, skb, info);
477}
478
479/*
480 * Function irlap_recv_discovery_xid_cmd (skb, info)
481 *
482 * Received a XID discovery command
483 *
484 */
485static void irlap_recv_discovery_xid_cmd(struct irlap_cb *self,
486 struct sk_buff *skb,
487 struct irlap_info *info)
488{
489 struct xid_frame *xid;
490 discovery_t *discovery = NULL;
491 __u8 *discovery_info;
492 char *text;
493
494 if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
495 IRDA_ERROR("%s: frame too short!\n", __func__);
496 return;
497 }
498
499 xid = (struct xid_frame *) skb->data;
500
501 info->daddr = le32_to_cpu(xid->saddr);
502 info->saddr = le32_to_cpu(xid->daddr);
503
504 /* Make sure frame is addressed to us */
505 if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
506 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
507 __func__);
508 return;
509 }
510
511 switch (xid->flags & 0x03) {
512 case 0x00:
513 info->S = 1;
514 break;
515 case 0x01:
516 info->S = 6;
517 break;
518 case 0x02:
519 info->S = 8;
520 break;
521 case 0x03:
522 info->S = 16;
523 break;
524 default:
525 /* Error!! */
526 return;
527 }
528 info->s = xid->slotnr;
529
530 discovery_info = skb_pull(skb, sizeof(struct xid_frame));
531
532 /*
533 * Check if last frame
534 */
535 if (info->s == 0xff) {
536 /* Check if things are sane at this point... */
537 if((discovery_info == NULL) ||
538 !pskb_may_pull(skb, 3)) {
539 IRDA_ERROR("%s: discovery frame too short!\n",
540 __func__);
541 return;
542 }
543
544 /*
545 * We now have some discovery info to deliver!
546 */
547 discovery = kzalloc(sizeof(discovery_t), GFP_ATOMIC);
548 if (!discovery) {
549 IRDA_WARNING("%s: unable to malloc!\n", __func__);
550 return;
551 }
552
553 discovery->data.daddr = info->daddr;
554 discovery->data.saddr = self->saddr;
555 discovery->timestamp = jiffies;
556
557 discovery->data.hints[0] = discovery_info[0];
558 if (discovery_info[0] & HINT_EXTENSION) {
559 discovery->data.hints[1] = discovery_info[1];
560 discovery->data.charset = discovery_info[2];
561 text = (char *) &discovery_info[3];
562 } else {
563 discovery->data.hints[1] = 0;
564 discovery->data.charset = discovery_info[1];
565 text = (char *) &discovery_info[2];
566 }
567 /*
568 * Terminate string, should be safe since this is where the
569 * FCS bytes resides.
570 */
571 skb->data[skb->len] = '\0';
572 strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
573 discovery->name_len = strlen(discovery->data.info);
574
575 info->discovery = discovery;
576 } else
577 info->discovery = NULL;
578
579 irlap_do_event(self, RECV_DISCOVERY_XID_CMD, skb, info);
580}
581
582/*
583 * Function irlap_send_rr_frame (self, command)
584 *
585 * Build and transmit RR (Receive Ready) frame. Notice that it is currently
586 * only possible to send RR frames with the poll bit set.
587 */
588void irlap_send_rr_frame(struct irlap_cb *self, int command)
589{
590 struct sk_buff *tx_skb;
591 struct rr_frame *frame;
592
593 tx_skb = alloc_skb(sizeof(struct rr_frame), GFP_ATOMIC);
594 if (!tx_skb)
595 return;
596
597 frame = (struct rr_frame *)skb_put(tx_skb, 2);
598
599 frame->caddr = self->caddr;
600 frame->caddr |= (command) ? CMD_FRAME : 0;
601
602 frame->control = RR | PF_BIT | (self->vr << 5);
603
604 irlap_queue_xmit(self, tx_skb);
605}
606
607/*
608 * Function irlap_send_rd_frame (self)
609 *
610 * Request disconnect. Used by a secondary station to request the
611 * disconnection of the link.
612 */
613void irlap_send_rd_frame(struct irlap_cb *self)
614{
615 struct sk_buff *tx_skb;
616 struct rd_frame *frame;
617
618 tx_skb = alloc_skb(sizeof(struct rd_frame), GFP_ATOMIC);
619 if (!tx_skb)
620 return;
621
622 frame = (struct rd_frame *)skb_put(tx_skb, 2);
623
624 frame->caddr = self->caddr;
625 frame->caddr = RD_RSP | PF_BIT;
626
627 irlap_queue_xmit(self, tx_skb);
628}
629
630/*
631 * Function irlap_recv_rr_frame (skb, info)
632 *
633 * Received RR (Receive Ready) frame from peer station, no harm in
634 * making it inline since its called only from one single place
635 * (irlap_driver_rcv).
636 */
637static inline void irlap_recv_rr_frame(struct irlap_cb *self,
638 struct sk_buff *skb,
639 struct irlap_info *info, int command)
640{
641 info->nr = skb->data[1] >> 5;
642
643 /* Check if this is a command or a response frame */
644 if (command)
645 irlap_do_event(self, RECV_RR_CMD, skb, info);
646 else
647 irlap_do_event(self, RECV_RR_RSP, skb, info);
648}
649
650/*
651 * Function irlap_recv_rnr_frame (self, skb, info)
652 *
653 * Received RNR (Receive Not Ready) frame from peer station
654 *
655 */
656static void irlap_recv_rnr_frame(struct irlap_cb *self, struct sk_buff *skb,
657 struct irlap_info *info, int command)
658{
659 info->nr = skb->data[1] >> 5;
660
661 IRDA_DEBUG(4, "%s(), nr=%d, %ld\n", __func__, info->nr, jiffies);
662
663 if (command)
664 irlap_do_event(self, RECV_RNR_CMD, skb, info);
665 else
666 irlap_do_event(self, RECV_RNR_RSP, skb, info);
667}
668
669static void irlap_recv_rej_frame(struct irlap_cb *self, struct sk_buff *skb,
670 struct irlap_info *info, int command)
671{
672 IRDA_DEBUG(0, "%s()\n", __func__);
673
674 info->nr = skb->data[1] >> 5;
675
676 /* Check if this is a command or a response frame */
677 if (command)
678 irlap_do_event(self, RECV_REJ_CMD, skb, info);
679 else
680 irlap_do_event(self, RECV_REJ_RSP, skb, info);
681}
682
683static void irlap_recv_srej_frame(struct irlap_cb *self, struct sk_buff *skb,
684 struct irlap_info *info, int command)
685{
686 IRDA_DEBUG(0, "%s()\n", __func__);
687
688 info->nr = skb->data[1] >> 5;
689
690 /* Check if this is a command or a response frame */
691 if (command)
692 irlap_do_event(self, RECV_SREJ_CMD, skb, info);
693 else
694 irlap_do_event(self, RECV_SREJ_RSP, skb, info);
695}
696
697static void irlap_recv_disc_frame(struct irlap_cb *self, struct sk_buff *skb,
698 struct irlap_info *info, int command)
699{
700 IRDA_DEBUG(2, "%s()\n", __func__);
701
702 /* Check if this is a command or a response frame */
703 if (command)
704 irlap_do_event(self, RECV_DISC_CMD, skb, info);
705 else
706 irlap_do_event(self, RECV_RD_RSP, skb, info);
707}
708
709/*
710 * Function irlap_recv_ua_frame (skb, frame)
711 *
712 * Received UA (Unnumbered Acknowledgement) frame
713 *
714 */
715static inline void irlap_recv_ua_frame(struct irlap_cb *self,
716 struct sk_buff *skb,
717 struct irlap_info *info)
718{
719 irlap_do_event(self, RECV_UA_RSP, skb, info);
720}
721
722/*
723 * Function irlap_send_data_primary(self, skb)
724 *
725 * Send I-frames as the primary station but without the poll bit set
726 *
727 */
728void irlap_send_data_primary(struct irlap_cb *self, struct sk_buff *skb)
729{
730 struct sk_buff *tx_skb;
731
732 if (skb->data[1] == I_FRAME) {
733
734 /*
735 * Insert frame sequence number (Vs) in control field before
736 * inserting into transmit window queue.
737 */
738 skb->data[1] = I_FRAME | (self->vs << 1);
739
740 /*
741 * Insert frame in store, in case of retransmissions
742 * Increase skb reference count, see irlap_do_event()
743 */
744 skb_get(skb);
745 skb_queue_tail(&self->wx_list, skb);
746
747 /* Copy buffer */
748 tx_skb = skb_clone(skb, GFP_ATOMIC);
749 if (tx_skb == NULL) {
750 return;
751 }
752
753 self->vs = (self->vs + 1) % 8;
754 self->ack_required = FALSE;
755 self->window -= 1;
756
757 irlap_send_i_frame( self, tx_skb, CMD_FRAME);
758 } else {
759 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __func__);
760 irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
761 self->window -= 1;
762 }
763}
764/*
765 * Function irlap_send_data_primary_poll (self, skb)
766 *
767 * Send I(nformation) frame as primary with poll bit set
768 */
769void irlap_send_data_primary_poll(struct irlap_cb *self, struct sk_buff *skb)
770{
771 struct sk_buff *tx_skb;
772 int transmission_time;
773
774 /* Stop P timer */
775 del_timer(&self->poll_timer);
776
777 /* Is this reliable or unreliable data? */
778 if (skb->data[1] == I_FRAME) {
779
780 /*
781 * Insert frame sequence number (Vs) in control field before
782 * inserting into transmit window queue.
783 */
784 skb->data[1] = I_FRAME | (self->vs << 1);
785
786 /*
787 * Insert frame in store, in case of retransmissions
788 * Increase skb reference count, see irlap_do_event()
789 */
790 skb_get(skb);
791 skb_queue_tail(&self->wx_list, skb);
792
793 /* Copy buffer */
794 tx_skb = skb_clone(skb, GFP_ATOMIC);
795 if (tx_skb == NULL) {
796 return;
797 }
798
799 /*
800 * Set poll bit if necessary. We do this to the copied
801 * skb, since retransmitted need to set or clear the poll
802 * bit depending on when they are sent.
803 */
804 tx_skb->data[1] |= PF_BIT;
805
806 self->vs = (self->vs + 1) % 8;
807 self->ack_required = FALSE;
808
809 irlap_next_state(self, LAP_NRM_P);
810 irlap_send_i_frame(self, tx_skb, CMD_FRAME);
811 } else {
812 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __func__);
813
814 if (self->ack_required) {
815 irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
816 irlap_next_state(self, LAP_NRM_P);
817 irlap_send_rr_frame(self, CMD_FRAME);
818 self->ack_required = FALSE;
819 } else {
820 skb->data[1] |= PF_BIT;
821 irlap_next_state(self, LAP_NRM_P);
822 irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
823 }
824 }
825
826 /* How much time we took for transmission of all frames.
827 * We don't know, so let assume we used the full window. Jean II */
828 transmission_time = self->final_timeout;
829
830 /* Reset parameter so that we can fill next window */
831 self->window = self->window_size;
832
833#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
834 /* Remove what we have not used. Just do a prorata of the
835 * bytes left in window to window capacity.
836 * See max_line_capacities[][] in qos.c for details. Jean II */
837 transmission_time -= (self->final_timeout * self->bytes_left
838 / self->line_capacity);
839 IRDA_DEBUG(4, "%s() adjusting transmission_time : ft=%d, bl=%d, lc=%d -> tt=%d\n", __func__, self->final_timeout, self->bytes_left, self->line_capacity, transmission_time);
840
841 /* We are allowed to transmit a maximum number of bytes again. */
842 self->bytes_left = self->line_capacity;
843#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
844
845 /*
846 * The network layer has a intermediate buffer between IrLAP
847 * and the IrDA driver which can contain 8 frames. So, even
848 * though IrLAP is currently sending the *last* frame of the
849 * tx-window, the driver most likely has only just started
850 * sending the *first* frame of the same tx-window.
851 * I.e. we are always at the very beginning of or Tx window.
852 * Now, we are supposed to set the final timer from the end
853 * of our tx-window to let the other peer reply. So, we need
854 * to add extra time to compensate for the fact that we
855 * are really at the start of tx-window, otherwise the final timer
856 * might expire before he can answer...
857 * Jean II
858 */
859 irlap_start_final_timer(self, self->final_timeout + transmission_time);
860
861 /*
862 * The clever amongst you might ask why we do this adjustement
863 * only here, and not in all the other cases in irlap_event.c.
864 * In all those other case, we only send a very short management
865 * frame (few bytes), so the adjustement would be lost in the
866 * noise...
867 * The exception of course is irlap_resend_rejected_frame().
868 * Jean II */
869}
870
871/*
872 * Function irlap_send_data_secondary_final (self, skb)
873 *
874 * Send I(nformation) frame as secondary with final bit set
875 *
876 */
877void irlap_send_data_secondary_final(struct irlap_cb *self,
878 struct sk_buff *skb)
879{
880 struct sk_buff *tx_skb = NULL;
881
882 IRDA_ASSERT(self != NULL, return;);
883 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
884 IRDA_ASSERT(skb != NULL, return;);
885
886 /* Is this reliable or unreliable data? */
887 if (skb->data[1] == I_FRAME) {
888
889 /*
890 * Insert frame sequence number (Vs) in control field before
891 * inserting into transmit window queue.
892 */
893 skb->data[1] = I_FRAME | (self->vs << 1);
894
895 /*
896 * Insert frame in store, in case of retransmissions
897 * Increase skb reference count, see irlap_do_event()
898 */
899 skb_get(skb);
900 skb_queue_tail(&self->wx_list, skb);
901
902 tx_skb = skb_clone(skb, GFP_ATOMIC);
903 if (tx_skb == NULL) {
904 return;
905 }
906
907 tx_skb->data[1] |= PF_BIT;
908
909 self->vs = (self->vs + 1) % 8;
910 self->ack_required = FALSE;
911
912 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
913 } else {
914 if (self->ack_required) {
915 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
916 irlap_send_rr_frame(self, RSP_FRAME);
917 self->ack_required = FALSE;
918 } else {
919 skb->data[1] |= PF_BIT;
920 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
921 }
922 }
923
924 self->window = self->window_size;
925#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
926 /* We are allowed to transmit a maximum number of bytes again. */
927 self->bytes_left = self->line_capacity;
928#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
929
930 irlap_start_wd_timer(self, self->wd_timeout);
931}
932
933/*
934 * Function irlap_send_data_secondary (self, skb)
935 *
936 * Send I(nformation) frame as secondary without final bit set
937 *
938 */
939void irlap_send_data_secondary(struct irlap_cb *self, struct sk_buff *skb)
940{
941 struct sk_buff *tx_skb = NULL;
942
943 /* Is this reliable or unreliable data? */
944 if (skb->data[1] == I_FRAME) {
945
946 /*
947 * Insert frame sequence number (Vs) in control field before
948 * inserting into transmit window queue.
949 */
950 skb->data[1] = I_FRAME | (self->vs << 1);
951
952 /*
953 * Insert frame in store, in case of retransmissions
954 * Increase skb reference count, see irlap_do_event()
955 */
956 skb_get(skb);
957 skb_queue_tail(&self->wx_list, skb);
958
959 tx_skb = skb_clone(skb, GFP_ATOMIC);
960 if (tx_skb == NULL) {
961 return;
962 }
963
964 self->vs = (self->vs + 1) % 8;
965 self->ack_required = FALSE;
966 self->window -= 1;
967
968 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
969 } else {
970 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
971 self->window -= 1;
972 }
973}
974
975/*
976 * Function irlap_resend_rejected_frames (nr)
977 *
978 * Resend frames which has not been acknowledged. Should be safe to
979 * traverse the list without locking it since this function will only be
980 * called from interrupt context (BH)
981 */
982void irlap_resend_rejected_frames(struct irlap_cb *self, int command)
983{
984 struct sk_buff *tx_skb;
985 struct sk_buff *skb;
986
987 IRDA_ASSERT(self != NULL, return;);
988 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
989
990 /* Resend unacknowledged frame(s) */
991 skb_queue_walk(&self->wx_list, skb) {
992 irlap_wait_min_turn_around(self, &self->qos_tx);
993
994 /* We copy the skb to be retransmitted since we will have to
995 * modify it. Cloning will confuse packet sniffers
996 */
997 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
998 tx_skb = skb_copy(skb, GFP_ATOMIC);
999 if (!tx_skb) {
1000 IRDA_DEBUG(0, "%s(), unable to copy\n", __func__);
1001 return;
1002 }
1003
1004 /* Clear old Nr field + poll bit */
1005 tx_skb->data[1] &= 0x0f;
1006
1007 /*
1008 * Set poll bit on the last frame retransmitted
1009 */
1010 if (skb_queue_is_last(&self->wx_list, skb))
1011 tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1012 else
1013 tx_skb->data[1] &= ~PF_BIT; /* Clear p/f bit */
1014
1015 irlap_send_i_frame(self, tx_skb, command);
1016 }
1017#if 0 /* Not yet */
1018 /*
1019 * We can now fill the window with additional data frames
1020 */
1021 while (!skb_queue_empty(&self->txq)) {
1022
1023 IRDA_DEBUG(0, "%s(), sending additional frames!\n", __func__);
1024 if (self->window > 0) {
1025 skb = skb_dequeue( &self->txq);
1026 IRDA_ASSERT(skb != NULL, return;);
1027
1028 /*
1029 * If send window > 1 then send frame with pf
1030 * bit cleared
1031 */
1032 if ((self->window > 1) &&
1033 !skb_queue_empty(&self->txq)) {
1034 irlap_send_data_primary(self, skb);
1035 } else {
1036 irlap_send_data_primary_poll(self, skb);
1037 }
1038 kfree_skb(skb);
1039 }
1040 }
1041#endif
1042}
1043
1044void irlap_resend_rejected_frame(struct irlap_cb *self, int command)
1045{
1046 struct sk_buff *tx_skb;
1047 struct sk_buff *skb;
1048
1049 IRDA_ASSERT(self != NULL, return;);
1050 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1051
1052 /* Resend unacknowledged frame(s) */
1053 skb = skb_peek(&self->wx_list);
1054 if (skb != NULL) {
1055 irlap_wait_min_turn_around(self, &self->qos_tx);
1056
1057 /* We copy the skb to be retransmitted since we will have to
1058 * modify it. Cloning will confuse packet sniffers
1059 */
1060 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
1061 tx_skb = skb_copy(skb, GFP_ATOMIC);
1062 if (!tx_skb) {
1063 IRDA_DEBUG(0, "%s(), unable to copy\n", __func__);
1064 return;
1065 }
1066
1067 /* Clear old Nr field + poll bit */
1068 tx_skb->data[1] &= 0x0f;
1069
1070 /* Set poll/final bit */
1071 tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1072
1073 irlap_send_i_frame(self, tx_skb, command);
1074 }
1075}
1076
1077/*
1078 * Function irlap_send_ui_frame (self, skb, command)
1079 *
1080 * Contruct and transmit an Unnumbered Information (UI) frame
1081 *
1082 */
1083void irlap_send_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1084 __u8 caddr, int command)
1085{
1086 IRDA_DEBUG(4, "%s()\n", __func__);
1087
1088 IRDA_ASSERT(self != NULL, return;);
1089 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1090 IRDA_ASSERT(skb != NULL, return;);
1091
1092 /* Insert connection address */
1093 skb->data[0] = caddr | ((command) ? CMD_FRAME : 0);
1094
1095 irlap_queue_xmit(self, skb);
1096}
1097
1098/*
1099 * Function irlap_send_i_frame (skb)
1100 *
1101 * Contruct and transmit Information (I) frame
1102 */
1103static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
1104 int command)
1105{
1106 /* Insert connection address */
1107 skb->data[0] = self->caddr;
1108 skb->data[0] |= (command) ? CMD_FRAME : 0;
1109
1110 /* Insert next to receive (Vr) */
1111 skb->data[1] |= (self->vr << 5); /* insert nr */
1112
1113 irlap_queue_xmit(self, skb);
1114}
1115
1116/*
1117 * Function irlap_recv_i_frame (skb, frame)
1118 *
1119 * Receive and parse an I (Information) frame, no harm in making it inline
1120 * since it's called only from one single place (irlap_driver_rcv).
1121 */
1122static inline void irlap_recv_i_frame(struct irlap_cb *self,
1123 struct sk_buff *skb,
1124 struct irlap_info *info, int command)
1125{
1126 info->nr = skb->data[1] >> 5; /* Next to receive */
1127 info->pf = skb->data[1] & PF_BIT; /* Final bit */
1128 info->ns = (skb->data[1] >> 1) & 0x07; /* Next to send */
1129
1130 /* Check if this is a command or a response frame */
1131 if (command)
1132 irlap_do_event(self, RECV_I_CMD, skb, info);
1133 else
1134 irlap_do_event(self, RECV_I_RSP, skb, info);
1135}
1136
1137/*
1138 * Function irlap_recv_ui_frame (self, skb, info)
1139 *
1140 * Receive and parse an Unnumbered Information (UI) frame
1141 *
1142 */
1143static void irlap_recv_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1144 struct irlap_info *info)
1145{
1146 IRDA_DEBUG( 4, "%s()\n", __func__);
1147
1148 info->pf = skb->data[1] & PF_BIT; /* Final bit */
1149
1150 irlap_do_event(self, RECV_UI_FRAME, skb, info);
1151}
1152
1153/*
1154 * Function irlap_recv_frmr_frame (skb, frame)
1155 *
1156 * Received Frame Reject response.
1157 *
1158 */
1159static void irlap_recv_frmr_frame(struct irlap_cb *self, struct sk_buff *skb,
1160 struct irlap_info *info)
1161{
1162 __u8 *frame;
1163 int w, x, y, z;
1164
1165 IRDA_DEBUG(0, "%s()\n", __func__);
1166
1167 IRDA_ASSERT(self != NULL, return;);
1168 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1169 IRDA_ASSERT(skb != NULL, return;);
1170 IRDA_ASSERT(info != NULL, return;);
1171
1172 if (!pskb_may_pull(skb, 4)) {
1173 IRDA_ERROR("%s: frame too short!\n", __func__);
1174 return;
1175 }
1176
1177 frame = skb->data;
1178
1179 info->nr = frame[2] >> 5; /* Next to receive */
1180 info->pf = frame[2] & PF_BIT; /* Final bit */
1181 info->ns = (frame[2] >> 1) & 0x07; /* Next to send */
1182
1183 w = frame[3] & 0x01;
1184 x = frame[3] & 0x02;
1185 y = frame[3] & 0x04;
1186 z = frame[3] & 0x08;
1187
1188 if (w) {
1189 IRDA_DEBUG(0, "Rejected control field is undefined or not "
1190 "implemented.\n");
1191 }
1192 if (x) {
1193 IRDA_DEBUG(0, "Rejected control field was invalid because it "
1194 "contained a non permitted I field.\n");
1195 }
1196 if (y) {
1197 IRDA_DEBUG(0, "Received I field exceeded the maximum negotiated "
1198 "for the existing connection or exceeded the maximum "
1199 "this station supports if no connection exists.\n");
1200 }
1201 if (z) {
1202 IRDA_DEBUG(0, "Rejected control field control field contained an "
1203 "invalid Nr count.\n");
1204 }
1205 irlap_do_event(self, RECV_FRMR_RSP, skb, info);
1206}
1207
1208/*
1209 * Function irlap_send_test_frame (self, daddr)
1210 *
1211 * Send a test frame response
1212 *
1213 */
1214void irlap_send_test_frame(struct irlap_cb *self, __u8 caddr, __u32 daddr,
1215 struct sk_buff *cmd)
1216{
1217 struct sk_buff *tx_skb;
1218 struct test_frame *frame;
1219 __u8 *info;
1220
1221 tx_skb = alloc_skb(cmd->len + sizeof(struct test_frame), GFP_ATOMIC);
1222 if (!tx_skb)
1223 return;
1224
1225 /* Broadcast frames must include saddr and daddr fields */
1226 if (caddr == CBROADCAST) {
1227 frame = (struct test_frame *)
1228 skb_put(tx_skb, sizeof(struct test_frame));
1229
1230 /* Insert the swapped addresses */
1231 frame->saddr = cpu_to_le32(self->saddr);
1232 frame->daddr = cpu_to_le32(daddr);
1233 } else
1234 frame = (struct test_frame *) skb_put(tx_skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);
1235
1236 frame->caddr = caddr;
1237 frame->control = TEST_RSP | PF_BIT;
1238
1239 /* Copy info */
1240 info = skb_put(tx_skb, cmd->len);
1241 memcpy(info, cmd->data, cmd->len);
1242
1243 /* Return to sender */
1244 irlap_wait_min_turn_around(self, &self->qos_tx);
1245 irlap_queue_xmit(self, tx_skb);
1246}
1247
1248/*
1249 * Function irlap_recv_test_frame (self, skb)
1250 *
1251 * Receive a test frame
1252 *
1253 */
1254static void irlap_recv_test_frame(struct irlap_cb *self, struct sk_buff *skb,
1255 struct irlap_info *info, int command)
1256{
1257 struct test_frame *frame;
1258
1259 IRDA_DEBUG(2, "%s()\n", __func__);
1260
1261 if (!pskb_may_pull(skb, sizeof(*frame))) {
1262 IRDA_ERROR("%s: frame too short!\n", __func__);
1263 return;
1264 }
1265 frame = (struct test_frame *) skb->data;
1266
1267 /* Broadcast frames must carry saddr and daddr fields */
1268 if (info->caddr == CBROADCAST) {
1269 if (skb->len < sizeof(struct test_frame)) {
1270 IRDA_DEBUG(0, "%s() test frame too short!\n",
1271 __func__);
1272 return;
1273 }
1274
1275 /* Read and swap addresses */
1276 info->daddr = le32_to_cpu(frame->saddr);
1277 info->saddr = le32_to_cpu(frame->daddr);
1278
1279 /* Make sure frame is addressed to us */
1280 if ((info->saddr != self->saddr) &&
1281 (info->saddr != BROADCAST)) {
1282 return;
1283 }
1284 }
1285
1286 if (command)
1287 irlap_do_event(self, RECV_TEST_CMD, skb, info);
1288 else
1289 irlap_do_event(self, RECV_TEST_RSP, skb, info);
1290}
1291
1292/*
1293 * Function irlap_driver_rcv (skb, netdev, ptype)
1294 *
1295 * Called when a frame is received. Dispatches the right receive function
1296 * for processing of the frame.
1297 *
1298 * Note on skb management :
1299 * After calling the higher layers of the IrDA stack, we always
1300 * kfree() the skb, which drop the reference count (and potentially
1301 * destroy it).
1302 * If a higher layer of the stack want to keep the skb around (to put
1303 * in a queue or pass it to the higher layer), it will need to use
1304 * skb_get() to keep a reference on it. This is usually done at the
1305 * LMP level in irlmp.c.
1306 * Jean II
1307 */
1308int irlap_driver_rcv(struct sk_buff *skb, struct net_device *dev,
1309 struct packet_type *ptype, struct net_device *orig_dev)
1310{
1311 struct irlap_info info;
1312 struct irlap_cb *self;
1313 int command;
1314 __u8 control;
1315 int ret = -1;
1316
1317 if (!net_eq(dev_net(dev), &init_net))
1318 goto out;
1319
1320 /* FIXME: should we get our own field? */
1321 self = (struct irlap_cb *) dev->atalk_ptr;
1322
1323 /* If the net device is down, then IrLAP is gone! */
1324 if (!self || self->magic != LAP_MAGIC)
1325 goto err;
1326
1327 /* We are no longer an "old" protocol, so we need to handle
1328 * share and non linear skbs. This should never happen, so
1329 * we don't need to be clever about it. Jean II */
1330 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
1331 IRDA_ERROR("%s: can't clone shared skb!\n", __func__);
1332 goto err;
1333 }
1334
1335 /* Check if frame is large enough for parsing */
1336 if (!pskb_may_pull(skb, 2)) {
1337 IRDA_ERROR("%s: frame too short!\n", __func__);
1338 goto err;
1339 }
1340
1341 command = skb->data[0] & CMD_FRAME;
1342 info.caddr = skb->data[0] & CBROADCAST;
1343
1344 info.pf = skb->data[1] & PF_BIT;
1345 info.control = skb->data[1] & ~PF_BIT; /* Mask away poll/final bit */
1346
1347 control = info.control;
1348
1349 /* First we check if this frame has a valid connection address */
1350 if ((info.caddr != self->caddr) && (info.caddr != CBROADCAST)) {
1351 IRDA_DEBUG(0, "%s(), wrong connection address!\n",
1352 __func__);
1353 goto out;
1354 }
1355 /*
1356 * Optimize for the common case and check if the frame is an
1357 * I(nformation) frame. Only I-frames have bit 0 set to 0
1358 */
1359 if (~control & 0x01) {
1360 irlap_recv_i_frame(self, skb, &info, command);
1361 goto out;
1362 }
1363 /*
1364 * We now check is the frame is an S(upervisory) frame. Only
1365 * S-frames have bit 0 set to 1 and bit 1 set to 0
1366 */
1367 if (~control & 0x02) {
1368 /*
1369 * Received S(upervisory) frame, check which frame type it is
1370 * only the first nibble is of interest
1371 */
1372 switch (control & 0x0f) {
1373 case RR:
1374 irlap_recv_rr_frame(self, skb, &info, command);
1375 break;
1376 case RNR:
1377 irlap_recv_rnr_frame(self, skb, &info, command);
1378 break;
1379 case REJ:
1380 irlap_recv_rej_frame(self, skb, &info, command);
1381 break;
1382 case SREJ:
1383 irlap_recv_srej_frame(self, skb, &info, command);
1384 break;
1385 default:
1386 IRDA_WARNING("%s: Unknown S-frame %02x received!\n",
1387 __func__, info.control);
1388 break;
1389 }
1390 goto out;
1391 }
1392 /*
1393 * This must be a C(ontrol) frame
1394 */
1395 switch (control) {
1396 case XID_RSP:
1397 irlap_recv_discovery_xid_rsp(self, skb, &info);
1398 break;
1399 case XID_CMD:
1400 irlap_recv_discovery_xid_cmd(self, skb, &info);
1401 break;
1402 case SNRM_CMD:
1403 irlap_recv_snrm_cmd(self, skb, &info);
1404 break;
1405 case DM_RSP:
1406 irlap_do_event(self, RECV_DM_RSP, skb, &info);
1407 break;
1408 case DISC_CMD: /* And RD_RSP since they have the same value */
1409 irlap_recv_disc_frame(self, skb, &info, command);
1410 break;
1411 case TEST_CMD:
1412 irlap_recv_test_frame(self, skb, &info, command);
1413 break;
1414 case UA_RSP:
1415 irlap_recv_ua_frame(self, skb, &info);
1416 break;
1417 case FRMR_RSP:
1418 irlap_recv_frmr_frame(self, skb, &info);
1419 break;
1420 case UI_FRAME:
1421 irlap_recv_ui_frame(self, skb, &info);
1422 break;
1423 default:
1424 IRDA_WARNING("%s: Unknown frame %02x received!\n",
1425 __func__, info.control);
1426 break;
1427 }
1428out:
1429 ret = 0;
1430err:
1431 /* Always drop our reference on the skb */
1432 dev_kfree_skb(skb);
1433 return ret;
1434}