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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*********************************************************************
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
33#include <net/pkt_sched.h>
34#include <net/sock.h>
35
36#include <asm/byteorder.h>
37
38#include <net/irda/irda.h>
39#include <net/irda/irda_device.h>
40#include <net/irda/irlap.h>
41#include <net/irda/wrapper.h>
42#include <net/irda/timer.h>
43#include <net/irda/irlap_frame.h>
44#include <net/irda/qos.h>
45
46static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
47 int command);
48
49/*
50 * Function irlap_insert_info (self, skb)
51 *
52 * Insert minimum turnaround time and speed information into the skb. We
53 * need to do this since it's per packet relevant information. Safe to
54 * have this function inlined since it's only called from one place
55 */
56static inline void irlap_insert_info(struct irlap_cb *self,
57 struct sk_buff *skb)
58{
59 struct irda_skb_cb *cb = (struct irda_skb_cb *) skb->cb;
60
61 /*
62 * Insert MTT (min. turn time) and speed into skb, so that the
63 * device driver knows which settings to use
64 */
65 cb->magic = LAP_MAGIC;
66 cb->mtt = self->mtt_required;
67 cb->next_speed = self->speed;
68
69 /* Reset */
70 self->mtt_required = 0;
71
72 /*
73 * Delay equals negotiated BOFs count, plus the number of BOFs to
74 * force the negotiated minimum turnaround time
75 */
76 cb->xbofs = self->bofs_count;
77 cb->next_xbofs = self->next_bofs;
78 cb->xbofs_delay = self->xbofs_delay;
79
80 /* Reset XBOF's delay (used only for getting min turn time) */
81 self->xbofs_delay = 0;
82 /* Put the correct xbofs value for the next packet */
83 self->bofs_count = self->next_bofs;
84}
85
86/*
87 * Function irlap_queue_xmit (self, skb)
88 *
89 * A little wrapper for dev_queue_xmit, so we can insert some common
90 * code into it.
91 */
92void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb)
93{
94 /* Some common init stuff */
95 skb->dev = self->netdev;
Arnaldo Carvalho de Melo459a98e2007-03-19 15:30:44 -070096 skb_reset_mac_header(skb);
Arnaldo Carvalho de Meloc1d2bbe2007-04-10 20:45:18 -070097 skb_reset_network_header(skb);
Arnaldo Carvalho de Melobadff6d2007-03-13 13:06:52 -030098 skb_reset_transport_header(skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 skb->protocol = htons(ETH_P_IRDA);
100 skb->priority = TC_PRIO_BESTEFFORT;
101
102 irlap_insert_info(self, skb);
103
104 dev_queue_xmit(skb);
105}
106
107/*
108 * Function irlap_send_snrm_cmd (void)
109 *
110 * Transmits a connect SNRM command frame
111 */
112void irlap_send_snrm_frame(struct irlap_cb *self, struct qos_info *qos)
113{
114 struct sk_buff *tx_skb;
115 struct snrm_frame *frame;
116 int ret;
117
118 IRDA_ASSERT(self != NULL, return;);
119 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
120
121 /* Allocate frame */
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700122 tx_skb = alloc_skb(sizeof(struct snrm_frame) +
123 IRLAP_NEGOCIATION_PARAMS_LEN,
124 GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 if (!tx_skb)
126 return;
127
128 frame = (struct snrm_frame *) skb_put(tx_skb, 2);
129
130 /* Insert connection address field */
131 if (qos)
132 frame->caddr = CMD_FRAME | CBROADCAST;
133 else
134 frame->caddr = CMD_FRAME | self->caddr;
135
136 /* Insert control field */
137 frame->control = SNRM_CMD | PF_BIT;
138
139 /*
140 * If we are establishing a connection then insert QoS paramerters
141 */
142 if (qos) {
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700143 skb_put(tx_skb, 9); /* 25 left */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 frame->saddr = cpu_to_le32(self->saddr);
145 frame->daddr = cpu_to_le32(self->daddr);
146
147 frame->ncaddr = self->caddr;
148
149 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
150 if (ret < 0) {
151 dev_kfree_skb(tx_skb);
152 return;
153 }
154 }
155 irlap_queue_xmit(self, tx_skb);
156}
157
158/*
159 * Function irlap_recv_snrm_cmd (skb, info)
160 *
161 * Received SNRM (Set Normal Response Mode) command frame
162 *
163 */
164static void irlap_recv_snrm_cmd(struct irlap_cb *self, struct sk_buff *skb,
165 struct irlap_info *info)
166{
167 struct snrm_frame *frame;
168
169 if (pskb_may_pull(skb,sizeof(struct snrm_frame))) {
170 frame = (struct snrm_frame *) skb->data;
171
172 /* Copy the new connection address ignoring the C/R bit */
173 info->caddr = frame->ncaddr & 0xFE;
174
175 /* Check if the new connection address is valid */
176 if ((info->caddr == 0x00) || (info->caddr == 0xfe)) {
177 IRDA_DEBUG(3, "%s(), invalid connection address!\n",
178 __FUNCTION__);
179 return;
180 }
181
182 /* Copy peer device address */
183 info->daddr = le32_to_cpu(frame->saddr);
184 info->saddr = le32_to_cpu(frame->daddr);
185
186 /* Only accept if addressed directly to us */
187 if (info->saddr != self->saddr) {
188 IRDA_DEBUG(2, "%s(), not addressed to us!\n",
189 __FUNCTION__);
190 return;
191 }
192 irlap_do_event(self, RECV_SNRM_CMD, skb, info);
193 } else {
194 /* Signal that this SNRM frame does not contain and I-field */
195 irlap_do_event(self, RECV_SNRM_CMD, skb, NULL);
196 }
197}
198
199/*
200 * Function irlap_send_ua_response_frame (qos)
201 *
202 * Send UA (Unnumbered Acknowledgement) frame
203 *
204 */
205void irlap_send_ua_response_frame(struct irlap_cb *self, struct qos_info *qos)
206{
207 struct sk_buff *tx_skb;
208 struct ua_frame *frame;
209 int ret;
210
211 IRDA_DEBUG(2, "%s() <%ld>\n", __FUNCTION__, jiffies);
212
213 IRDA_ASSERT(self != NULL, return;);
214 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
215
216 /* Allocate frame */
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700217 tx_skb = alloc_skb(sizeof(struct ua_frame) +
218 IRLAP_NEGOCIATION_PARAMS_LEN,
219 GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 if (!tx_skb)
221 return;
222
223 frame = (struct ua_frame *) skb_put(tx_skb, 10);
224
225 /* Build UA response */
226 frame->caddr = self->caddr;
227 frame->control = UA_RSP | PF_BIT;
228
229 frame->saddr = cpu_to_le32(self->saddr);
230 frame->daddr = cpu_to_le32(self->daddr);
231
232 /* Should we send QoS negotiation parameters? */
233 if (qos) {
234 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
235 if (ret < 0) {
236 dev_kfree_skb(tx_skb);
237 return;
238 }
239 }
240
241 irlap_queue_xmit(self, tx_skb);
242}
243
244
245/*
246 * Function irlap_send_dm_frame (void)
247 *
248 * Send disconnected mode (DM) frame
249 *
250 */
251void irlap_send_dm_frame( struct irlap_cb *self)
252{
253 struct sk_buff *tx_skb = NULL;
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700254 struct dm_frame *frame;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256 IRDA_ASSERT(self != NULL, return;);
257 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
258
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700259 tx_skb = alloc_skb(sizeof(struct dm_frame), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 if (!tx_skb)
261 return;
262
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700263 frame = (struct dm_frame *)skb_put(tx_skb, 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264
265 if (self->state == LAP_NDM)
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700266 frame->caddr = CBROADCAST;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 else
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700268 frame->caddr = self->caddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700270 frame->control = DM_RSP | PF_BIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271
272 irlap_queue_xmit(self, tx_skb);
273}
274
275/*
276 * Function irlap_send_disc_frame (void)
277 *
278 * Send disconnect (DISC) frame
279 *
280 */
281void irlap_send_disc_frame(struct irlap_cb *self)
282{
283 struct sk_buff *tx_skb = NULL;
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700284 struct disc_frame *frame;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
286 IRDA_DEBUG(3, "%s()\n", __FUNCTION__);
287
288 IRDA_ASSERT(self != NULL, return;);
289 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
290
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700291 tx_skb = alloc_skb(sizeof(struct disc_frame), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 if (!tx_skb)
293 return;
294
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700295 frame = (struct disc_frame *)skb_put(tx_skb, 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700297 frame->caddr = self->caddr | CMD_FRAME;
298 frame->control = DISC_CMD | PF_BIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299
300 irlap_queue_xmit(self, tx_skb);
301}
302
303/*
304 * Function irlap_send_discovery_xid_frame (S, s, command)
305 *
306 * Build and transmit a XID (eXchange station IDentifier) discovery
307 * frame.
308 */
309void irlap_send_discovery_xid_frame(struct irlap_cb *self, int S, __u8 s,
310 __u8 command, discovery_t *discovery)
311{
312 struct sk_buff *tx_skb = NULL;
313 struct xid_frame *frame;
314 __u32 bcast = BROADCAST;
315 __u8 *info;
316
317 IRDA_DEBUG(4, "%s(), s=%d, S=%d, command=%d\n", __FUNCTION__,
318 s, S, command);
319
320 IRDA_ASSERT(self != NULL, return;);
321 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
322 IRDA_ASSERT(discovery != NULL, return;);
323
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700324 tx_skb = alloc_skb(sizeof(struct xid_frame) + IRLAP_DISCOVERY_INFO_LEN,
325 GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 if (!tx_skb)
327 return;
328
329 skb_put(tx_skb, 14);
330 frame = (struct xid_frame *) tx_skb->data;
331
332 if (command) {
333 frame->caddr = CBROADCAST | CMD_FRAME;
334 frame->control = XID_CMD | PF_BIT;
335 } else {
336 frame->caddr = CBROADCAST;
337 frame->control = XID_RSP | PF_BIT;
338 }
339 frame->ident = XID_FORMAT;
340
341 frame->saddr = cpu_to_le32(self->saddr);
342
343 if (command)
344 frame->daddr = cpu_to_le32(bcast);
345 else
346 frame->daddr = cpu_to_le32(discovery->data.daddr);
347
348 switch (S) {
349 case 1:
350 frame->flags = 0x00;
351 break;
352 case 6:
353 frame->flags = 0x01;
354 break;
355 case 8:
356 frame->flags = 0x02;
357 break;
358 case 16:
359 frame->flags = 0x03;
360 break;
361 default:
362 frame->flags = 0x02;
363 break;
364 }
365
366 frame->slotnr = s;
367 frame->version = 0x00;
368
369 /*
370 * Provide info for final slot only in commands, and for all
371 * responses. Send the second byte of the hint only if the
372 * EXTENSION bit is set in the first byte.
373 */
374 if (!command || (frame->slotnr == 0xff)) {
375 int len;
376
377 if (discovery->data.hints[0] & HINT_EXTENSION) {
378 info = skb_put(tx_skb, 2);
379 info[0] = discovery->data.hints[0];
380 info[1] = discovery->data.hints[1];
381 } else {
382 info = skb_put(tx_skb, 1);
383 info[0] = discovery->data.hints[0];
384 }
385 info = skb_put(tx_skb, 1);
386 info[0] = discovery->data.charset;
387
388 len = IRDA_MIN(discovery->name_len, skb_tailroom(tx_skb));
389 info = skb_put(tx_skb, len);
390 memcpy(info, discovery->data.info, len);
391 }
392 irlap_queue_xmit(self, tx_skb);
393}
394
395/*
396 * Function irlap_recv_discovery_xid_rsp (skb, info)
397 *
398 * Received a XID discovery response
399 *
400 */
401static void irlap_recv_discovery_xid_rsp(struct irlap_cb *self,
402 struct sk_buff *skb,
403 struct irlap_info *info)
404{
405 struct xid_frame *xid;
406 discovery_t *discovery = NULL;
407 __u8 *discovery_info;
408 char *text;
409
410 IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
411
412 IRDA_ASSERT(self != NULL, return;);
413 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
414
415 if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
416 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
417 return;
418 }
YOSHIFUJI Hideaki6819bc22007-02-09 23:24:53 +0900419
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 xid = (struct xid_frame *) skb->data;
421
422 info->daddr = le32_to_cpu(xid->saddr);
423 info->saddr = le32_to_cpu(xid->daddr);
424
425 /* Make sure frame is addressed to us */
426 if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
427 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
428 __FUNCTION__);
429 return;
430 }
431
Panagiotis Issaris0da974f2006-07-21 14:51:30 -0700432 if ((discovery = kzalloc(sizeof(discovery_t), GFP_ATOMIC)) == NULL) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 IRDA_WARNING("%s: kmalloc failed!\n", __FUNCTION__);
434 return;
435 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436
437 discovery->data.daddr = info->daddr;
438 discovery->data.saddr = self->saddr;
439 discovery->timestamp = jiffies;
440
441 IRDA_DEBUG(4, "%s(), daddr=%08x\n", __FUNCTION__,
442 discovery->data.daddr);
443
444 discovery_info = skb_pull(skb, sizeof(struct xid_frame));
445
446 /* Get info returned from peer */
447 discovery->data.hints[0] = discovery_info[0];
448 if (discovery_info[0] & HINT_EXTENSION) {
449 IRDA_DEBUG(4, "EXTENSION\n");
450 discovery->data.hints[1] = discovery_info[1];
451 discovery->data.charset = discovery_info[2];
452 text = (char *) &discovery_info[3];
453 } else {
454 discovery->data.hints[1] = 0;
455 discovery->data.charset = discovery_info[1];
456 text = (char *) &discovery_info[2];
457 }
458 /*
459 * Terminate info string, should be safe since this is where the
460 * FCS bytes resides.
461 */
462 skb->data[skb->len] = '\0';
463 strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
464 discovery->name_len = strlen(discovery->data.info);
465
466 info->discovery = discovery;
467
468 irlap_do_event(self, RECV_DISCOVERY_XID_RSP, skb, info);
469}
470
471/*
472 * Function irlap_recv_discovery_xid_cmd (skb, info)
473 *
474 * Received a XID discovery command
475 *
476 */
477static void irlap_recv_discovery_xid_cmd(struct irlap_cb *self,
478 struct sk_buff *skb,
479 struct irlap_info *info)
480{
481 struct xid_frame *xid;
482 discovery_t *discovery = NULL;
483 __u8 *discovery_info;
484 char *text;
485
486 if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
487 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
488 return;
489 }
YOSHIFUJI Hideaki6819bc22007-02-09 23:24:53 +0900490
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 xid = (struct xid_frame *) skb->data;
492
493 info->daddr = le32_to_cpu(xid->saddr);
494 info->saddr = le32_to_cpu(xid->daddr);
495
496 /* Make sure frame is addressed to us */
497 if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
498 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
499 __FUNCTION__);
500 return;
501 }
502
503 switch (xid->flags & 0x03) {
504 case 0x00:
505 info->S = 1;
506 break;
507 case 0x01:
508 info->S = 6;
509 break;
510 case 0x02:
511 info->S = 8;
512 break;
513 case 0x03:
514 info->S = 16;
515 break;
516 default:
517 /* Error!! */
518 return;
519 }
520 info->s = xid->slotnr;
521
522 discovery_info = skb_pull(skb, sizeof(struct xid_frame));
523
524 /*
525 * Check if last frame
526 */
527 if (info->s == 0xff) {
528 /* Check if things are sane at this point... */
YOSHIFUJI Hideaki6819bc22007-02-09 23:24:53 +0900529 if((discovery_info == NULL) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 !pskb_may_pull(skb, 3)) {
531 IRDA_ERROR("%s: discovery frame to short!\n",
532 __FUNCTION__);
533 return;
534 }
535
536 /*
537 * We now have some discovery info to deliver!
538 */
539 discovery = kmalloc(sizeof(discovery_t), GFP_ATOMIC);
540 if (!discovery) {
541 IRDA_WARNING("%s: unable to malloc!\n", __FUNCTION__);
542 return;
543 }
544
545 discovery->data.daddr = info->daddr;
546 discovery->data.saddr = self->saddr;
547 discovery->timestamp = jiffies;
548
549 discovery->data.hints[0] = discovery_info[0];
550 if (discovery_info[0] & HINT_EXTENSION) {
551 discovery->data.hints[1] = discovery_info[1];
552 discovery->data.charset = discovery_info[2];
553 text = (char *) &discovery_info[3];
554 } else {
555 discovery->data.hints[1] = 0;
556 discovery->data.charset = discovery_info[1];
557 text = (char *) &discovery_info[2];
558 }
559 /*
560 * Terminate string, should be safe since this is where the
561 * FCS bytes resides.
562 */
563 skb->data[skb->len] = '\0';
564 strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
565 discovery->name_len = strlen(discovery->data.info);
566
567 info->discovery = discovery;
568 } else
569 info->discovery = NULL;
570
571 irlap_do_event(self, RECV_DISCOVERY_XID_CMD, skb, info);
572}
573
574/*
575 * Function irlap_send_rr_frame (self, command)
576 *
577 * Build and transmit RR (Receive Ready) frame. Notice that it is currently
578 * only possible to send RR frames with the poll bit set.
579 */
580void irlap_send_rr_frame(struct irlap_cb *self, int command)
581{
582 struct sk_buff *tx_skb;
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700583 struct rr_frame *frame;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700585 tx_skb = alloc_skb(sizeof(struct rr_frame), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 if (!tx_skb)
587 return;
588
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700589 frame = (struct rr_frame *)skb_put(tx_skb, 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700591 frame->caddr = self->caddr;
592 frame->caddr |= (command) ? CMD_FRAME : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700594 frame->control = RR | PF_BIT | (self->vr << 5);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595
596 irlap_queue_xmit(self, tx_skb);
597}
598
599/*
600 * Function irlap_send_rd_frame (self)
601 *
602 * Request disconnect. Used by a secondary station to request the
603 * disconnection of the link.
604 */
605void irlap_send_rd_frame(struct irlap_cb *self)
606{
607 struct sk_buff *tx_skb;
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700608 struct rd_frame *frame;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700610 tx_skb = alloc_skb(sizeof(struct rd_frame), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 if (!tx_skb)
612 return;
613
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700614 frame = (struct rd_frame *)skb_put(tx_skb, 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615
Samuel Ortiz1b0fee72006-09-27 20:06:44 -0700616 frame->caddr = self->caddr;
617 frame->caddr = RD_RSP | PF_BIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618
619 irlap_queue_xmit(self, tx_skb);
620}
621
622/*
623 * Function irlap_recv_rr_frame (skb, info)
624 *
625 * Received RR (Receive Ready) frame from peer station, no harm in
626 * making it inline since its called only from one single place
627 * (irlap_driver_rcv).
628 */
629static inline void irlap_recv_rr_frame(struct irlap_cb *self,
630 struct sk_buff *skb,
631 struct irlap_info *info, int command)
632{
633 info->nr = skb->data[1] >> 5;
634
635 /* Check if this is a command or a response frame */
636 if (command)
637 irlap_do_event(self, RECV_RR_CMD, skb, info);
638 else
639 irlap_do_event(self, RECV_RR_RSP, skb, info);
640}
641
642/*
643 * Function irlap_recv_rnr_frame (self, skb, info)
644 *
645 * Received RNR (Receive Not Ready) frame from peer station
646 *
647 */
648static void irlap_recv_rnr_frame(struct irlap_cb *self, struct sk_buff *skb,
649 struct irlap_info *info, int command)
650{
651 info->nr = skb->data[1] >> 5;
652
653 IRDA_DEBUG(4, "%s(), nr=%d, %ld\n", __FUNCTION__, info->nr, jiffies);
654
655 if (command)
656 irlap_do_event(self, RECV_RNR_CMD, skb, info);
657 else
658 irlap_do_event(self, RECV_RNR_RSP, skb, info);
659}
660
661static void irlap_recv_rej_frame(struct irlap_cb *self, struct sk_buff *skb,
662 struct irlap_info *info, int command)
663{
664 IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
665
666 info->nr = skb->data[1] >> 5;
667
668 /* Check if this is a command or a response frame */
669 if (command)
670 irlap_do_event(self, RECV_REJ_CMD, skb, info);
671 else
672 irlap_do_event(self, RECV_REJ_RSP, skb, info);
673}
674
675static void irlap_recv_srej_frame(struct irlap_cb *self, struct sk_buff *skb,
676 struct irlap_info *info, int command)
677{
678 IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
679
680 info->nr = skb->data[1] >> 5;
681
682 /* Check if this is a command or a response frame */
683 if (command)
684 irlap_do_event(self, RECV_SREJ_CMD, skb, info);
685 else
686 irlap_do_event(self, RECV_SREJ_RSP, skb, info);
687}
688
689static void irlap_recv_disc_frame(struct irlap_cb *self, struct sk_buff *skb,
690 struct irlap_info *info, int command)
691{
692 IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
693
694 /* Check if this is a command or a response frame */
695 if (command)
696 irlap_do_event(self, RECV_DISC_CMD, skb, info);
697 else
698 irlap_do_event(self, RECV_RD_RSP, skb, info);
699}
700
701/*
702 * Function irlap_recv_ua_frame (skb, frame)
703 *
704 * Received UA (Unnumbered Acknowledgement) frame
705 *
706 */
707static inline void irlap_recv_ua_frame(struct irlap_cb *self,
708 struct sk_buff *skb,
709 struct irlap_info *info)
710{
711 irlap_do_event(self, RECV_UA_RSP, skb, info);
712}
713
714/*
715 * Function irlap_send_data_primary(self, skb)
716 *
717 * Send I-frames as the primary station but without the poll bit set
718 *
719 */
720void irlap_send_data_primary(struct irlap_cb *self, struct sk_buff *skb)
721{
722 struct sk_buff *tx_skb;
723
724 if (skb->data[1] == I_FRAME) {
725
726 /*
727 * Insert frame sequence number (Vs) in control field before
728 * inserting into transmit window queue.
729 */
730 skb->data[1] = I_FRAME | (self->vs << 1);
731
732 /*
733 * Insert frame in store, in case of retransmissions
734 * Increase skb reference count, see irlap_do_event()
735 */
736 skb_get(skb);
737 skb_queue_tail(&self->wx_list, skb);
738
739 /* Copy buffer */
740 tx_skb = skb_clone(skb, GFP_ATOMIC);
741 if (tx_skb == NULL) {
742 return;
743 }
744
745 self->vs = (self->vs + 1) % 8;
746 self->ack_required = FALSE;
747 self->window -= 1;
748
749 irlap_send_i_frame( self, tx_skb, CMD_FRAME);
750 } else {
751 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__);
752 irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
753 self->window -= 1;
754 }
755}
756/*
757 * Function irlap_send_data_primary_poll (self, skb)
758 *
759 * Send I(nformation) frame as primary with poll bit set
760 */
761void irlap_send_data_primary_poll(struct irlap_cb *self, struct sk_buff *skb)
762{
763 struct sk_buff *tx_skb;
764 int transmission_time;
765
766 /* Stop P timer */
767 del_timer(&self->poll_timer);
768
769 /* Is this reliable or unreliable data? */
770 if (skb->data[1] == I_FRAME) {
771
772 /*
773 * Insert frame sequence number (Vs) in control field before
774 * inserting into transmit window queue.
775 */
776 skb->data[1] = I_FRAME | (self->vs << 1);
777
778 /*
779 * Insert frame in store, in case of retransmissions
780 * Increase skb reference count, see irlap_do_event()
781 */
782 skb_get(skb);
783 skb_queue_tail(&self->wx_list, skb);
784
785 /* Copy buffer */
786 tx_skb = skb_clone(skb, GFP_ATOMIC);
787 if (tx_skb == NULL) {
788 return;
789 }
790
791 /*
792 * Set poll bit if necessary. We do this to the copied
793 * skb, since retransmitted need to set or clear the poll
794 * bit depending on when they are sent.
795 */
796 tx_skb->data[1] |= PF_BIT;
797
798 self->vs = (self->vs + 1) % 8;
799 self->ack_required = FALSE;
800
801 irlap_send_i_frame(self, tx_skb, CMD_FRAME);
802 } else {
803 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__);
804
805 if (self->ack_required) {
806 irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
807 irlap_send_rr_frame(self, CMD_FRAME);
808 self->ack_required = FALSE;
809 } else {
810 skb->data[1] |= PF_BIT;
811 irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
812 }
813 }
814
815 /* How much time we took for transmission of all frames.
816 * We don't know, so let assume we used the full window. Jean II */
817 transmission_time = self->final_timeout;
818
819 /* Reset parameter so that we can fill next window */
820 self->window = self->window_size;
821
822#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
823 /* Remove what we have not used. Just do a prorata of the
824 * bytes left in window to window capacity.
825 * See max_line_capacities[][] in qos.c for details. Jean II */
826 transmission_time -= (self->final_timeout * self->bytes_left
827 / self->line_capacity);
828 IRDA_DEBUG(4, "%s() adjusting transmission_time : ft=%d, bl=%d, lc=%d -> tt=%d\n", __FUNCTION__, self->final_timeout, self->bytes_left, self->line_capacity, transmission_time);
829
830 /* We are allowed to transmit a maximum number of bytes again. */
831 self->bytes_left = self->line_capacity;
832#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
833
834 /*
835 * The network layer has a intermediate buffer between IrLAP
836 * and the IrDA driver which can contain 8 frames. So, even
837 * though IrLAP is currently sending the *last* frame of the
838 * tx-window, the driver most likely has only just started
839 * sending the *first* frame of the same tx-window.
840 * I.e. we are always at the very begining of or Tx window.
841 * Now, we are supposed to set the final timer from the end
842 * of our tx-window to let the other peer reply. So, we need
843 * to add extra time to compensate for the fact that we
844 * are really at the start of tx-window, otherwise the final timer
845 * might expire before he can answer...
846 * Jean II
847 */
848 irlap_start_final_timer(self, self->final_timeout + transmission_time);
849
850 /*
851 * The clever amongst you might ask why we do this adjustement
852 * only here, and not in all the other cases in irlap_event.c.
853 * In all those other case, we only send a very short management
854 * frame (few bytes), so the adjustement would be lost in the
855 * noise...
856 * The exception of course is irlap_resend_rejected_frame().
857 * Jean II */
858}
859
860/*
861 * Function irlap_send_data_secondary_final (self, skb)
862 *
863 * Send I(nformation) frame as secondary with final bit set
864 *
865 */
866void irlap_send_data_secondary_final(struct irlap_cb *self,
867 struct sk_buff *skb)
868{
869 struct sk_buff *tx_skb = NULL;
870
871 IRDA_ASSERT(self != NULL, return;);
872 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
873 IRDA_ASSERT(skb != NULL, return;);
874
875 /* Is this reliable or unreliable data? */
876 if (skb->data[1] == I_FRAME) {
877
878 /*
879 * Insert frame sequence number (Vs) in control field before
880 * inserting into transmit window queue.
881 */
882 skb->data[1] = I_FRAME | (self->vs << 1);
883
884 /*
885 * Insert frame in store, in case of retransmissions
886 * Increase skb reference count, see irlap_do_event()
887 */
888 skb_get(skb);
889 skb_queue_tail(&self->wx_list, skb);
890
891 tx_skb = skb_clone(skb, GFP_ATOMIC);
892 if (tx_skb == NULL) {
893 return;
894 }
895
896 tx_skb->data[1] |= PF_BIT;
897
898 self->vs = (self->vs + 1) % 8;
899 self->ack_required = FALSE;
900
901 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
902 } else {
903 if (self->ack_required) {
904 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
905 irlap_send_rr_frame(self, RSP_FRAME);
906 self->ack_required = FALSE;
907 } else {
908 skb->data[1] |= PF_BIT;
909 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
910 }
911 }
912
913 self->window = self->window_size;
914#ifdef CONFIG_IRDA_DYNAMIC_WINDOW
915 /* We are allowed to transmit a maximum number of bytes again. */
916 self->bytes_left = self->line_capacity;
917#endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
918
919 irlap_start_wd_timer(self, self->wd_timeout);
920}
921
922/*
923 * Function irlap_send_data_secondary (self, skb)
924 *
925 * Send I(nformation) frame as secondary without final bit set
926 *
927 */
928void irlap_send_data_secondary(struct irlap_cb *self, struct sk_buff *skb)
929{
930 struct sk_buff *tx_skb = NULL;
931
932 /* Is this reliable or unreliable data? */
933 if (skb->data[1] == I_FRAME) {
934
935 /*
936 * Insert frame sequence number (Vs) in control field before
937 * inserting into transmit window queue.
938 */
939 skb->data[1] = I_FRAME | (self->vs << 1);
940
941 /*
942 * Insert frame in store, in case of retransmissions
943 * Increase skb reference count, see irlap_do_event()
944 */
945 skb_get(skb);
946 skb_queue_tail(&self->wx_list, skb);
947
948 tx_skb = skb_clone(skb, GFP_ATOMIC);
949 if (tx_skb == NULL) {
950 return;
951 }
952
953 self->vs = (self->vs + 1) % 8;
954 self->ack_required = FALSE;
955 self->window -= 1;
956
957 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
958 } else {
959 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
960 self->window -= 1;
961 }
962}
963
964/*
965 * Function irlap_resend_rejected_frames (nr)
966 *
967 * Resend frames which has not been acknowledged. Should be safe to
968 * traverse the list without locking it since this function will only be
969 * called from interrupt context (BH)
970 */
971void irlap_resend_rejected_frames(struct irlap_cb *self, int command)
972{
973 struct sk_buff *tx_skb;
974 struct sk_buff *skb;
975 int count;
976
977 IRDA_ASSERT(self != NULL, return;);
978 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
979
980 /* Initialize variables */
981 count = skb_queue_len(&self->wx_list);
982
983 /* Resend unacknowledged frame(s) */
984 skb = skb_peek(&self->wx_list);
985 while (skb != NULL) {
986 irlap_wait_min_turn_around(self, &self->qos_tx);
987
988 /* We copy the skb to be retransmitted since we will have to
989 * modify it. Cloning will confuse packet sniffers
990 */
991 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
992 tx_skb = skb_copy(skb, GFP_ATOMIC);
993 if (!tx_skb) {
994 IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__);
995 return;
996 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997
998 /* Clear old Nr field + poll bit */
999 tx_skb->data[1] &= 0x0f;
1000
1001 /*
1002 * Set poll bit on the last frame retransmitted
1003 */
1004 if (count-- == 1)
1005 tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1006 else
1007 tx_skb->data[1] &= ~PF_BIT; /* Clear p/f bit */
1008
1009 irlap_send_i_frame(self, tx_skb, command);
1010
1011 /*
1012 * If our skb is the last buffer in the list, then
1013 * we are finished, if not, move to the next sk-buffer
1014 */
1015 if (skb == skb_peek_tail(&self->wx_list))
1016 skb = NULL;
1017 else
1018 skb = skb->next;
1019 }
1020#if 0 /* Not yet */
1021 /*
1022 * We can now fill the window with additional data frames
1023 */
David S. Millerb03efcf2005-07-08 14:57:23 -07001024 while (!skb_queue_empty(&self->txq)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025
1026 IRDA_DEBUG(0, "%s(), sending additional frames!\n", __FUNCTION__);
David S. Millerb03efcf2005-07-08 14:57:23 -07001027 if (self->window > 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 skb = skb_dequeue( &self->txq);
1029 IRDA_ASSERT(skb != NULL, return;);
1030
1031 /*
1032 * If send window > 1 then send frame with pf
1033 * bit cleared
1034 */
1035 if ((self->window > 1) &&
David S. Millerb03efcf2005-07-08 14:57:23 -07001036 !skb_queue_empty(&self->txq)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001037 irlap_send_data_primary(self, skb);
1038 } else {
1039 irlap_send_data_primary_poll(self, skb);
1040 }
1041 kfree_skb(skb);
1042 }
1043 }
1044#endif
1045}
1046
1047void irlap_resend_rejected_frame(struct irlap_cb *self, int command)
1048{
1049 struct sk_buff *tx_skb;
1050 struct sk_buff *skb;
1051
1052 IRDA_ASSERT(self != NULL, return;);
1053 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1054
1055 /* Resend unacknowledged frame(s) */
1056 skb = skb_peek(&self->wx_list);
1057 if (skb != NULL) {
1058 irlap_wait_min_turn_around(self, &self->qos_tx);
1059
1060 /* We copy the skb to be retransmitted since we will have to
1061 * modify it. Cloning will confuse packet sniffers
1062 */
1063 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
1064 tx_skb = skb_copy(skb, GFP_ATOMIC);
1065 if (!tx_skb) {
1066 IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__);
1067 return;
1068 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069
1070 /* Clear old Nr field + poll bit */
1071 tx_skb->data[1] &= 0x0f;
1072
1073 /* Set poll/final bit */
1074 tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1075
1076 irlap_send_i_frame(self, tx_skb, command);
1077 }
1078}
1079
1080/*
1081 * Function irlap_send_ui_frame (self, skb, command)
1082 *
1083 * Contruct and transmit an Unnumbered Information (UI) frame
1084 *
1085 */
1086void irlap_send_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1087 __u8 caddr, int command)
1088{
1089 IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1090
1091 IRDA_ASSERT(self != NULL, return;);
1092 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1093 IRDA_ASSERT(skb != NULL, return;);
1094
1095 /* Insert connection address */
1096 skb->data[0] = caddr | ((command) ? CMD_FRAME : 0);
1097
1098 irlap_queue_xmit(self, skb);
1099}
1100
1101/*
1102 * Function irlap_send_i_frame (skb)
1103 *
1104 * Contruct and transmit Information (I) frame
1105 */
1106static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
1107 int command)
1108{
1109 /* Insert connection address */
1110 skb->data[0] = self->caddr;
1111 skb->data[0] |= (command) ? CMD_FRAME : 0;
1112
1113 /* Insert next to receive (Vr) */
1114 skb->data[1] |= (self->vr << 5); /* insert nr */
1115
1116 irlap_queue_xmit(self, skb);
1117}
1118
1119/*
1120 * Function irlap_recv_i_frame (skb, frame)
1121 *
1122 * Receive and parse an I (Information) frame, no harm in making it inline
1123 * since it's called only from one single place (irlap_driver_rcv).
1124 */
1125static inline void irlap_recv_i_frame(struct irlap_cb *self,
1126 struct sk_buff *skb,
1127 struct irlap_info *info, int command)
1128{
1129 info->nr = skb->data[1] >> 5; /* Next to receive */
1130 info->pf = skb->data[1] & PF_BIT; /* Final bit */
1131 info->ns = (skb->data[1] >> 1) & 0x07; /* Next to send */
1132
1133 /* Check if this is a command or a response frame */
1134 if (command)
1135 irlap_do_event(self, RECV_I_CMD, skb, info);
1136 else
1137 irlap_do_event(self, RECV_I_RSP, skb, info);
1138}
1139
1140/*
1141 * Function irlap_recv_ui_frame (self, skb, info)
1142 *
1143 * Receive and parse an Unnumbered Information (UI) frame
1144 *
1145 */
1146static void irlap_recv_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1147 struct irlap_info *info)
1148{
1149 IRDA_DEBUG( 4, "%s()\n", __FUNCTION__);
1150
1151 info->pf = skb->data[1] & PF_BIT; /* Final bit */
1152
1153 irlap_do_event(self, RECV_UI_FRAME, skb, info);
1154}
1155
1156/*
1157 * Function irlap_recv_frmr_frame (skb, frame)
1158 *
1159 * Received Frame Reject response.
1160 *
1161 */
1162static void irlap_recv_frmr_frame(struct irlap_cb *self, struct sk_buff *skb,
1163 struct irlap_info *info)
1164{
1165 __u8 *frame;
1166 int w, x, y, z;
1167
1168 IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
1169
1170 IRDA_ASSERT(self != NULL, return;);
1171 IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1172 IRDA_ASSERT(skb != NULL, return;);
1173 IRDA_ASSERT(info != NULL, return;);
1174
1175 if (!pskb_may_pull(skb, 4)) {
1176 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
1177 return;
1178 }
1179
1180 frame = skb->data;
1181
1182 info->nr = frame[2] >> 5; /* Next to receive */
1183 info->pf = frame[2] & PF_BIT; /* Final bit */
1184 info->ns = (frame[2] >> 1) & 0x07; /* Next to send */
1185
1186 w = frame[3] & 0x01;
1187 x = frame[3] & 0x02;
1188 y = frame[3] & 0x04;
1189 z = frame[3] & 0x08;
1190
1191 if (w) {
1192 IRDA_DEBUG(0, "Rejected control field is undefined or not "
1193 "implemented.\n");
1194 }
1195 if (x) {
1196 IRDA_DEBUG(0, "Rejected control field was invalid because it "
1197 "contained a non permitted I field.\n");
1198 }
1199 if (y) {
1200 IRDA_DEBUG(0, "Received I field exceeded the maximum negotiated "
1201 "for the existing connection or exceeded the maximum "
1202 "this station supports if no connection exists.\n");
1203 }
1204 if (z) {
1205 IRDA_DEBUG(0, "Rejected control field control field contained an "
1206 "invalid Nr count.\n");
1207 }
1208 irlap_do_event(self, RECV_FRMR_RSP, skb, info);
1209}
1210
1211/*
1212 * Function irlap_send_test_frame (self, daddr)
1213 *
1214 * Send a test frame response
1215 *
1216 */
1217void irlap_send_test_frame(struct irlap_cb *self, __u8 caddr, __u32 daddr,
1218 struct sk_buff *cmd)
1219{
1220 struct sk_buff *tx_skb;
1221 struct test_frame *frame;
1222 __u8 *info;
1223
Samuel Ortiz1b0fee72006-09-27 20:06:44 -07001224 tx_skb = alloc_skb(cmd->len + sizeof(struct test_frame), GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 if (!tx_skb)
1226 return;
1227
1228 /* Broadcast frames must include saddr and daddr fields */
1229 if (caddr == CBROADCAST) {
1230 frame = (struct test_frame *)
1231 skb_put(tx_skb, sizeof(struct test_frame));
1232
1233 /* Insert the swapped addresses */
1234 frame->saddr = cpu_to_le32(self->saddr);
1235 frame->daddr = cpu_to_le32(daddr);
1236 } else
1237 frame = (struct test_frame *) skb_put(tx_skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);
1238
1239 frame->caddr = caddr;
1240 frame->control = TEST_RSP | PF_BIT;
1241
1242 /* Copy info */
1243 info = skb_put(tx_skb, cmd->len);
1244 memcpy(info, cmd->data, cmd->len);
1245
1246 /* Return to sender */
1247 irlap_wait_min_turn_around(self, &self->qos_tx);
1248 irlap_queue_xmit(self, tx_skb);
1249}
1250
1251/*
1252 * Function irlap_recv_test_frame (self, skb)
1253 *
1254 * Receive a test frame
1255 *
1256 */
1257static void irlap_recv_test_frame(struct irlap_cb *self, struct sk_buff *skb,
1258 struct irlap_info *info, int command)
1259{
1260 struct test_frame *frame;
1261
1262 IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
1263
1264 if (!pskb_may_pull(skb, sizeof(*frame))) {
1265 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
1266 return;
1267 }
1268 frame = (struct test_frame *) skb->data;
1269
1270 /* Broadcast frames must carry saddr and daddr fields */
1271 if (info->caddr == CBROADCAST) {
1272 if (skb->len < sizeof(struct test_frame)) {
1273 IRDA_DEBUG(0, "%s() test frame to short!\n",
1274 __FUNCTION__);
1275 return;
1276 }
1277
1278 /* Read and swap addresses */
1279 info->daddr = le32_to_cpu(frame->saddr);
1280 info->saddr = le32_to_cpu(frame->daddr);
1281
1282 /* Make sure frame is addressed to us */
1283 if ((info->saddr != self->saddr) &&
1284 (info->saddr != BROADCAST)) {
1285 return;
1286 }
1287 }
1288
1289 if (command)
1290 irlap_do_event(self, RECV_TEST_CMD, skb, info);
1291 else
1292 irlap_do_event(self, RECV_TEST_RSP, skb, info);
1293}
1294
1295/*
1296 * Function irlap_driver_rcv (skb, netdev, ptype)
1297 *
1298 * Called when a frame is received. Dispatches the right receive function
1299 * for processing of the frame.
1300 *
1301 * Note on skb management :
1302 * After calling the higher layers of the IrDA stack, we always
1303 * kfree() the skb, which drop the reference count (and potentially
1304 * destroy it).
1305 * If a higher layer of the stack want to keep the skb around (to put
1306 * in a queue or pass it to the higher layer), it will need to use
1307 * skb_get() to keep a reference on it. This is usually done at the
1308 * LMP level in irlmp.c.
1309 * Jean II
1310 */
1311int irlap_driver_rcv(struct sk_buff *skb, struct net_device *dev,
David S. Millerf2ccd8f2005-08-09 19:34:12 -07001312 struct packet_type *ptype, struct net_device *orig_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313{
1314 struct irlap_info info;
1315 struct irlap_cb *self;
1316 int command;
1317 __u8 control;
1318
1319 /* FIXME: should we get our own field? */
1320 self = (struct irlap_cb *) dev->atalk_ptr;
1321
1322 /* If the net device is down, then IrLAP is gone! */
1323 if (!self || self->magic != LAP_MAGIC) {
1324 dev_kfree_skb(skb);
1325 return -1;
1326 }
1327
1328 /* We are no longer an "old" protocol, so we need to handle
1329 * share and non linear skbs. This should never happen, so
1330 * we don't need to be clever about it. Jean II */
1331 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
1332 IRDA_ERROR("%s: can't clone shared skb!\n", __FUNCTION__);
1333 dev_kfree_skb(skb);
1334 return -1;
1335 }
1336
1337 /* Check if frame is large enough for parsing */
1338 if (!pskb_may_pull(skb, 2)) {
1339 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
1340 dev_kfree_skb(skb);
1341 return -1;
1342 }
1343
1344 command = skb->data[0] & CMD_FRAME;
1345 info.caddr = skb->data[0] & CBROADCAST;
1346
1347 info.pf = skb->data[1] & PF_BIT;
1348 info.control = skb->data[1] & ~PF_BIT; /* Mask away poll/final bit */
1349
1350 control = info.control;
1351
1352 /* First we check if this frame has a valid connection address */
1353 if ((info.caddr != self->caddr) && (info.caddr != CBROADCAST)) {
1354 IRDA_DEBUG(0, "%s(), wrong connection address!\n",
1355 __FUNCTION__);
1356 goto out;
1357 }
1358 /*
1359 * Optimize for the common case and check if the frame is an
1360 * I(nformation) frame. Only I-frames have bit 0 set to 0
1361 */
1362 if (~control & 0x01) {
1363 irlap_recv_i_frame(self, skb, &info, command);
1364 goto out;
1365 }
1366 /*
1367 * We now check is the frame is an S(upervisory) frame. Only
1368 * S-frames have bit 0 set to 1 and bit 1 set to 0
1369 */
1370 if (~control & 0x02) {
1371 /*
1372 * Received S(upervisory) frame, check which frame type it is
1373 * only the first nibble is of interest
1374 */
1375 switch (control & 0x0f) {
1376 case RR:
1377 irlap_recv_rr_frame(self, skb, &info, command);
1378 break;
1379 case RNR:
1380 irlap_recv_rnr_frame(self, skb, &info, command);
1381 break;
1382 case REJ:
1383 irlap_recv_rej_frame(self, skb, &info, command);
1384 break;
1385 case SREJ:
1386 irlap_recv_srej_frame(self, skb, &info, command);
1387 break;
1388 default:
1389 IRDA_WARNING("%s: Unknown S-frame %02x received!\n",
1390 __FUNCTION__, info.control);
1391 break;
1392 }
1393 goto out;
1394 }
1395 /*
1396 * This must be a C(ontrol) frame
1397 */
1398 switch (control) {
1399 case XID_RSP:
1400 irlap_recv_discovery_xid_rsp(self, skb, &info);
1401 break;
1402 case XID_CMD:
1403 irlap_recv_discovery_xid_cmd(self, skb, &info);
1404 break;
1405 case SNRM_CMD:
1406 irlap_recv_snrm_cmd(self, skb, &info);
1407 break;
1408 case DM_RSP:
1409 irlap_do_event(self, RECV_DM_RSP, skb, &info);
1410 break;
1411 case DISC_CMD: /* And RD_RSP since they have the same value */
1412 irlap_recv_disc_frame(self, skb, &info, command);
1413 break;
1414 case TEST_CMD:
1415 irlap_recv_test_frame(self, skb, &info, command);
1416 break;
1417 case UA_RSP:
1418 irlap_recv_ua_frame(self, skb, &info);
1419 break;
1420 case FRMR_RSP:
1421 irlap_recv_frmr_frame(self, skb, &info);
1422 break;
1423 case UI_FRAME:
1424 irlap_recv_ui_frame(self, skb, &info);
1425 break;
1426 default:
1427 IRDA_WARNING("%s: Unknown frame %02x received!\n",
1428 __FUNCTION__, info.control);
1429 break;
1430 }
1431out:
1432 /* Always drop our reference on the skb */
1433 dev_kfree_skb(skb);
1434 return 0;
1435}