[NET] NETNS: Omit net_device->nd_net without CONFIG_NET_NS.
[linux-3.10.git] / net / irda / irlap_frame.c
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
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
46 static 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  */
56 static 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  */
92 void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb)
93 {
94         /* Some common init stuff */
95         skb->dev = self->netdev;
96         skb_reset_mac_header(skb);
97         skb_reset_network_header(skb);
98         skb_reset_transport_header(skb);
99         skb->protocol = htons(ETH_P_IRDA);
100         skb->priority = TC_PRIO_BESTEFFORT;
101
102         irlap_insert_info(self, skb);
103
104         if (unlikely(self->mode & IRDA_MODE_MONITOR)) {
105                 IRDA_DEBUG(3, "%s(): %s is in monitor mode\n", __func__,
106                            self->netdev->name);
107                 dev_kfree_skb(skb);
108                 return;
109         }
110
111         dev_queue_xmit(skb);
112 }
113
114 /*
115  * Function irlap_send_snrm_cmd (void)
116  *
117  *    Transmits a connect SNRM command frame
118  */
119 void irlap_send_snrm_frame(struct irlap_cb *self, struct qos_info *qos)
120 {
121         struct sk_buff *tx_skb;
122         struct snrm_frame *frame;
123         int ret;
124
125         IRDA_ASSERT(self != NULL, return;);
126         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
127
128         /* Allocate frame */
129         tx_skb = alloc_skb(sizeof(struct snrm_frame) +
130                            IRLAP_NEGOCIATION_PARAMS_LEN,
131                            GFP_ATOMIC);
132         if (!tx_skb)
133                 return;
134
135         frame = (struct snrm_frame *) skb_put(tx_skb, 2);
136
137         /* Insert connection address field */
138         if (qos)
139                 frame->caddr = CMD_FRAME | CBROADCAST;
140         else
141                 frame->caddr = CMD_FRAME | self->caddr;
142
143         /* Insert control field */
144         frame->control = SNRM_CMD | PF_BIT;
145
146         /*
147          *  If we are establishing a connection then insert QoS parameters
148          */
149         if (qos) {
150                 skb_put(tx_skb, 9); /* 25 left */
151                 frame->saddr = cpu_to_le32(self->saddr);
152                 frame->daddr = cpu_to_le32(self->daddr);
153
154                 frame->ncaddr = self->caddr;
155
156                 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
157                 if (ret < 0) {
158                         dev_kfree_skb(tx_skb);
159                         return;
160                 }
161         }
162         irlap_queue_xmit(self, tx_skb);
163 }
164
165 /*
166  * Function irlap_recv_snrm_cmd (skb, info)
167  *
168  *    Received SNRM (Set Normal Response Mode) command frame
169  *
170  */
171 static void irlap_recv_snrm_cmd(struct irlap_cb *self, struct sk_buff *skb,
172                                 struct irlap_info *info)
173 {
174         struct snrm_frame *frame;
175
176         if (pskb_may_pull(skb,sizeof(struct snrm_frame))) {
177                 frame = (struct snrm_frame *) skb->data;
178
179                 /* Copy the new connection address ignoring the C/R bit */
180                 info->caddr = frame->ncaddr & 0xFE;
181
182                 /* Check if the new connection address is valid */
183                 if ((info->caddr == 0x00) || (info->caddr == 0xfe)) {
184                         IRDA_DEBUG(3, "%s(), invalid connection address!\n",
185                                    __func__);
186                         return;
187                 }
188
189                 /* Copy peer device address */
190                 info->daddr = le32_to_cpu(frame->saddr);
191                 info->saddr = le32_to_cpu(frame->daddr);
192
193                 /* Only accept if addressed directly to us */
194                 if (info->saddr != self->saddr) {
195                         IRDA_DEBUG(2, "%s(), not addressed to us!\n",
196                                    __func__);
197                         return;
198                 }
199                 irlap_do_event(self, RECV_SNRM_CMD, skb, info);
200         } else {
201                 /* Signal that this SNRM frame does not contain and I-field */
202                 irlap_do_event(self, RECV_SNRM_CMD, skb, NULL);
203         }
204 }
205
206 /*
207  * Function irlap_send_ua_response_frame (qos)
208  *
209  *    Send UA (Unnumbered Acknowledgement) frame
210  *
211  */
212 void irlap_send_ua_response_frame(struct irlap_cb *self, struct qos_info *qos)
213 {
214         struct sk_buff *tx_skb;
215         struct ua_frame *frame;
216         int ret;
217
218         IRDA_DEBUG(2, "%s() <%ld>\n", __func__, jiffies);
219
220         IRDA_ASSERT(self != NULL, return;);
221         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
222
223         /* Allocate frame */
224         tx_skb = alloc_skb(sizeof(struct ua_frame) +
225                            IRLAP_NEGOCIATION_PARAMS_LEN,
226                            GFP_ATOMIC);
227         if (!tx_skb)
228                 return;
229
230         frame = (struct ua_frame *) skb_put(tx_skb, 10);
231
232         /* Build UA response */
233         frame->caddr = self->caddr;
234         frame->control = UA_RSP | PF_BIT;
235
236         frame->saddr = cpu_to_le32(self->saddr);
237         frame->daddr = cpu_to_le32(self->daddr);
238
239         /* Should we send QoS negotiation parameters? */
240         if (qos) {
241                 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
242                 if (ret < 0) {
243                         dev_kfree_skb(tx_skb);
244                         return;
245                 }
246         }
247
248         irlap_queue_xmit(self, tx_skb);
249 }
250
251
252 /*
253  * Function irlap_send_dm_frame (void)
254  *
255  *    Send disconnected mode (DM) frame
256  *
257  */
258 void irlap_send_dm_frame( struct irlap_cb *self)
259 {
260         struct sk_buff *tx_skb = NULL;
261         struct dm_frame *frame;
262
263         IRDA_ASSERT(self != NULL, return;);
264         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
265
266         tx_skb = alloc_skb(sizeof(struct dm_frame), GFP_ATOMIC);
267         if (!tx_skb)
268                 return;
269
270         frame = (struct dm_frame *)skb_put(tx_skb, 2);
271
272         if (self->state == LAP_NDM)
273                 frame->caddr = CBROADCAST;
274         else
275                 frame->caddr = self->caddr;
276
277         frame->control = DM_RSP | PF_BIT;
278
279         irlap_queue_xmit(self, tx_skb);
280 }
281
282 /*
283  * Function irlap_send_disc_frame (void)
284  *
285  *    Send disconnect (DISC) frame
286  *
287  */
288 void irlap_send_disc_frame(struct irlap_cb *self)
289 {
290         struct sk_buff *tx_skb = NULL;
291         struct disc_frame *frame;
292
293         IRDA_DEBUG(3, "%s()\n", __func__);
294
295         IRDA_ASSERT(self != NULL, return;);
296         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
297
298         tx_skb = alloc_skb(sizeof(struct disc_frame), GFP_ATOMIC);
299         if (!tx_skb)
300                 return;
301
302         frame = (struct disc_frame *)skb_put(tx_skb, 2);
303
304         frame->caddr = self->caddr | CMD_FRAME;
305         frame->control = DISC_CMD | PF_BIT;
306
307         irlap_queue_xmit(self, tx_skb);
308 }
309
310 /*
311  * Function irlap_send_discovery_xid_frame (S, s, command)
312  *
313  *    Build and transmit a XID (eXchange station IDentifier) discovery
314  *    frame.
315  */
316 void irlap_send_discovery_xid_frame(struct irlap_cb *self, int S, __u8 s,
317                                     __u8 command, discovery_t *discovery)
318 {
319         struct sk_buff *tx_skb = NULL;
320         struct xid_frame *frame;
321         __u32 bcast = BROADCAST;
322         __u8 *info;
323
324         IRDA_DEBUG(4, "%s(), s=%d, S=%d, command=%d\n", __func__,
325                    s, S, command);
326
327         IRDA_ASSERT(self != NULL, return;);
328         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
329         IRDA_ASSERT(discovery != NULL, return;);
330
331         tx_skb = alloc_skb(sizeof(struct xid_frame) + IRLAP_DISCOVERY_INFO_LEN,
332                            GFP_ATOMIC);
333         if (!tx_skb)
334                 return;
335
336         skb_put(tx_skb, 14);
337         frame = (struct xid_frame *) tx_skb->data;
338
339         if (command) {
340                 frame->caddr = CBROADCAST | CMD_FRAME;
341                 frame->control =  XID_CMD | PF_BIT;
342         } else {
343                 frame->caddr = CBROADCAST;
344                 frame->control =  XID_RSP | PF_BIT;
345         }
346         frame->ident = XID_FORMAT;
347
348         frame->saddr = cpu_to_le32(self->saddr);
349
350         if (command)
351                 frame->daddr = cpu_to_le32(bcast);
352         else
353                 frame->daddr = cpu_to_le32(discovery->data.daddr);
354
355         switch (S) {
356         case 1:
357                 frame->flags = 0x00;
358                 break;
359         case 6:
360                 frame->flags = 0x01;
361                 break;
362         case 8:
363                 frame->flags = 0x02;
364                 break;
365         case 16:
366                 frame->flags = 0x03;
367                 break;
368         default:
369                 frame->flags = 0x02;
370                 break;
371         }
372
373         frame->slotnr = s;
374         frame->version = 0x00;
375
376         /*
377          *  Provide info for final slot only in commands, and for all
378          *  responses. Send the second byte of the hint only if the
379          *  EXTENSION bit is set in the first byte.
380          */
381         if (!command || (frame->slotnr == 0xff)) {
382                 int len;
383
384                 if (discovery->data.hints[0] & HINT_EXTENSION) {
385                         info = skb_put(tx_skb, 2);
386                         info[0] = discovery->data.hints[0];
387                         info[1] = discovery->data.hints[1];
388                 } else {
389                         info = skb_put(tx_skb, 1);
390                         info[0] = discovery->data.hints[0];
391                 }
392                 info = skb_put(tx_skb, 1);
393                 info[0] = discovery->data.charset;
394
395                 len = IRDA_MIN(discovery->name_len, skb_tailroom(tx_skb));
396                 info = skb_put(tx_skb, len);
397                 memcpy(info, discovery->data.info, len);
398         }
399         irlap_queue_xmit(self, tx_skb);
400 }
401
402 /*
403  * Function irlap_recv_discovery_xid_rsp (skb, info)
404  *
405  *    Received a XID discovery response
406  *
407  */
408 static void irlap_recv_discovery_xid_rsp(struct irlap_cb *self,
409                                          struct sk_buff *skb,
410                                          struct irlap_info *info)
411 {
412         struct xid_frame *xid;
413         discovery_t *discovery = NULL;
414         __u8 *discovery_info;
415         char *text;
416
417         IRDA_DEBUG(4, "%s()\n", __func__);
418
419         IRDA_ASSERT(self != NULL, return;);
420         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
421
422         if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
423                 IRDA_ERROR("%s: frame too short!\n", __func__);
424                 return;
425         }
426
427         xid = (struct xid_frame *) skb->data;
428
429         info->daddr = le32_to_cpu(xid->saddr);
430         info->saddr = le32_to_cpu(xid->daddr);
431
432         /* Make sure frame is addressed to us */
433         if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
434                 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
435                            __func__);
436                 return;
437         }
438
439         if ((discovery = kzalloc(sizeof(discovery_t), GFP_ATOMIC)) == NULL) {
440                 IRDA_WARNING("%s: kmalloc failed!\n", __func__);
441                 return;
442         }
443
444         discovery->data.daddr = info->daddr;
445         discovery->data.saddr = self->saddr;
446         discovery->timestamp = jiffies;
447
448         IRDA_DEBUG(4, "%s(), daddr=%08x\n", __func__,
449                    discovery->data.daddr);
450
451         discovery_info = skb_pull(skb, sizeof(struct xid_frame));
452
453         /* Get info returned from peer */
454         discovery->data.hints[0] = discovery_info[0];
455         if (discovery_info[0] & HINT_EXTENSION) {
456                 IRDA_DEBUG(4, "EXTENSION\n");
457                 discovery->data.hints[1] = discovery_info[1];
458                 discovery->data.charset = discovery_info[2];
459                 text = (char *) &discovery_info[3];
460         } else {
461                 discovery->data.hints[1] = 0;
462                 discovery->data.charset = discovery_info[1];
463                 text = (char *) &discovery_info[2];
464         }
465         /*
466          *  Terminate info string, should be safe since this is where the
467          *  FCS bytes resides.
468          */
469         skb->data[skb->len] = '\0';
470         strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
471         discovery->name_len = strlen(discovery->data.info);
472
473         info->discovery = discovery;
474
475         irlap_do_event(self, RECV_DISCOVERY_XID_RSP, skb, info);
476 }
477
478 /*
479  * Function irlap_recv_discovery_xid_cmd (skb, info)
480  *
481  *    Received a XID discovery command
482  *
483  */
484 static void irlap_recv_discovery_xid_cmd(struct irlap_cb *self,
485                                          struct sk_buff *skb,
486                                          struct irlap_info *info)
487 {
488         struct xid_frame *xid;
489         discovery_t *discovery = NULL;
490         __u8 *discovery_info;
491         char *text;
492
493         if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
494                 IRDA_ERROR("%s: frame too short!\n", __func__);
495                 return;
496         }
497
498         xid = (struct xid_frame *) skb->data;
499
500         info->daddr = le32_to_cpu(xid->saddr);
501         info->saddr = le32_to_cpu(xid->daddr);
502
503         /* Make sure frame is addressed to us */
504         if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
505                 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
506                            __func__);
507                 return;
508         }
509
510         switch (xid->flags & 0x03) {
511         case 0x00:
512                 info->S = 1;
513                 break;
514         case 0x01:
515                 info->S = 6;
516                 break;
517         case 0x02:
518                 info->S = 8;
519                 break;
520         case 0x03:
521                 info->S = 16;
522                 break;
523         default:
524                 /* Error!! */
525                 return;
526         }
527         info->s = xid->slotnr;
528
529         discovery_info = skb_pull(skb, sizeof(struct xid_frame));
530
531         /*
532          *  Check if last frame
533          */
534         if (info->s == 0xff) {
535                 /* Check if things are sane at this point... */
536                 if((discovery_info == NULL) ||
537                    !pskb_may_pull(skb, 3)) {
538                         IRDA_ERROR("%s: discovery frame too short!\n",
539                                    __func__);
540                         return;
541                 }
542
543                 /*
544                  *  We now have some discovery info to deliver!
545                  */
546                 discovery = kmalloc(sizeof(discovery_t), GFP_ATOMIC);
547                 if (!discovery) {
548                         IRDA_WARNING("%s: unable to malloc!\n", __func__);
549                         return;
550                 }
551
552                 discovery->data.daddr = info->daddr;
553                 discovery->data.saddr = self->saddr;
554                 discovery->timestamp = jiffies;
555
556                 discovery->data.hints[0] = discovery_info[0];
557                 if (discovery_info[0] & HINT_EXTENSION) {
558                         discovery->data.hints[1] = discovery_info[1];
559                         discovery->data.charset = discovery_info[2];
560                         text = (char *) &discovery_info[3];
561                 } else {
562                         discovery->data.hints[1] = 0;
563                         discovery->data.charset = discovery_info[1];
564                         text = (char *) &discovery_info[2];
565                 }
566                 /*
567                  *  Terminate string, should be safe since this is where the
568                  *  FCS bytes resides.
569                  */
570                 skb->data[skb->len] = '\0';
571                 strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
572                 discovery->name_len = strlen(discovery->data.info);
573
574                 info->discovery = discovery;
575         } else
576                 info->discovery = NULL;
577
578         irlap_do_event(self, RECV_DISCOVERY_XID_CMD, skb, info);
579 }
580
581 /*
582  * Function irlap_send_rr_frame (self, command)
583  *
584  *    Build and transmit RR (Receive Ready) frame. Notice that it is currently
585  *    only possible to send RR frames with the poll bit set.
586  */
587 void irlap_send_rr_frame(struct irlap_cb *self, int command)
588 {
589         struct sk_buff *tx_skb;
590         struct rr_frame *frame;
591
592         tx_skb = alloc_skb(sizeof(struct rr_frame), GFP_ATOMIC);
593         if (!tx_skb)
594                 return;
595
596         frame = (struct rr_frame *)skb_put(tx_skb, 2);
597
598         frame->caddr = self->caddr;
599         frame->caddr |= (command) ? CMD_FRAME : 0;
600
601         frame->control = RR | PF_BIT | (self->vr << 5);
602
603         irlap_queue_xmit(self, tx_skb);
604 }
605
606 /*
607  * Function irlap_send_rd_frame (self)
608  *
609  *    Request disconnect. Used by a secondary station to request the
610  *    disconnection of the link.
611  */
612 void irlap_send_rd_frame(struct irlap_cb *self)
613 {
614         struct sk_buff *tx_skb;
615         struct rd_frame *frame;
616
617         tx_skb = alloc_skb(sizeof(struct rd_frame), GFP_ATOMIC);
618         if (!tx_skb)
619                 return;
620
621         frame = (struct rd_frame *)skb_put(tx_skb, 2);
622
623         frame->caddr = self->caddr;
624         frame->caddr = RD_RSP | PF_BIT;
625
626         irlap_queue_xmit(self, tx_skb);
627 }
628
629 /*
630  * Function irlap_recv_rr_frame (skb, info)
631  *
632  *    Received RR (Receive Ready) frame from peer station, no harm in
633  *    making it inline since its called only from one single place
634  *    (irlap_driver_rcv).
635  */
636 static inline void irlap_recv_rr_frame(struct irlap_cb *self,
637                                        struct sk_buff *skb,
638                                        struct irlap_info *info, int command)
639 {
640         info->nr = skb->data[1] >> 5;
641
642         /* Check if this is a command or a response frame */
643         if (command)
644                 irlap_do_event(self, RECV_RR_CMD, skb, info);
645         else
646                 irlap_do_event(self, RECV_RR_RSP, skb, info);
647 }
648
649 /*
650  * Function irlap_recv_rnr_frame (self, skb, info)
651  *
652  *    Received RNR (Receive Not Ready) frame from peer station
653  *
654  */
655 static void irlap_recv_rnr_frame(struct irlap_cb *self, struct sk_buff *skb,
656                                  struct irlap_info *info, int command)
657 {
658         info->nr = skb->data[1] >> 5;
659
660         IRDA_DEBUG(4, "%s(), nr=%d, %ld\n", __func__, info->nr, jiffies);
661
662         if (command)
663                 irlap_do_event(self, RECV_RNR_CMD, skb, info);
664         else
665                 irlap_do_event(self, RECV_RNR_RSP, skb, info);
666 }
667
668 static void irlap_recv_rej_frame(struct irlap_cb *self, struct sk_buff *skb,
669                                  struct irlap_info *info, int command)
670 {
671         IRDA_DEBUG(0, "%s()\n", __func__);
672
673         info->nr = skb->data[1] >> 5;
674
675         /* Check if this is a command or a response frame */
676         if (command)
677                 irlap_do_event(self, RECV_REJ_CMD, skb, info);
678         else
679                 irlap_do_event(self, RECV_REJ_RSP, skb, info);
680 }
681
682 static void irlap_recv_srej_frame(struct irlap_cb *self, struct sk_buff *skb,
683                                   struct irlap_info *info, int command)
684 {
685         IRDA_DEBUG(0, "%s()\n", __func__);
686
687         info->nr = skb->data[1] >> 5;
688
689         /* Check if this is a command or a response frame */
690         if (command)
691                 irlap_do_event(self, RECV_SREJ_CMD, skb, info);
692         else
693                 irlap_do_event(self, RECV_SREJ_RSP, skb, info);
694 }
695
696 static void irlap_recv_disc_frame(struct irlap_cb *self, struct sk_buff *skb,
697                                   struct irlap_info *info, int command)
698 {
699         IRDA_DEBUG(2, "%s()\n", __func__);
700
701         /* Check if this is a command or a response frame */
702         if (command)
703                 irlap_do_event(self, RECV_DISC_CMD, skb, info);
704         else
705                 irlap_do_event(self, RECV_RD_RSP, skb, info);
706 }
707
708 /*
709  * Function irlap_recv_ua_frame (skb, frame)
710  *
711  *    Received UA (Unnumbered Acknowledgement) frame
712  *
713  */
714 static inline void irlap_recv_ua_frame(struct irlap_cb *self,
715                                        struct sk_buff *skb,
716                                        struct irlap_info *info)
717 {
718         irlap_do_event(self, RECV_UA_RSP, skb, info);
719 }
720
721 /*
722  * Function irlap_send_data_primary(self, skb)
723  *
724  *    Send I-frames as the primary station but without the poll bit set
725  *
726  */
727 void irlap_send_data_primary(struct irlap_cb *self, struct sk_buff *skb)
728 {
729         struct sk_buff *tx_skb;
730
731         if (skb->data[1] == I_FRAME) {
732
733                 /*
734                  *  Insert frame sequence number (Vs) in control field before
735                  *  inserting into transmit window queue.
736                  */
737                 skb->data[1] = I_FRAME | (self->vs << 1);
738
739                 /*
740                  *  Insert frame in store, in case of retransmissions
741                  *  Increase skb reference count, see irlap_do_event()
742                  */
743                 skb_get(skb);
744                 skb_queue_tail(&self->wx_list, skb);
745
746                 /* Copy buffer */
747                 tx_skb = skb_clone(skb, GFP_ATOMIC);
748                 if (tx_skb == NULL) {
749                         return;
750                 }
751
752                 self->vs = (self->vs + 1) % 8;
753                 self->ack_required = FALSE;
754                 self->window -= 1;
755
756                 irlap_send_i_frame( self, tx_skb, CMD_FRAME);
757         } else {
758                 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __func__);
759                 irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
760                 self->window -= 1;
761         }
762 }
763 /*
764  * Function irlap_send_data_primary_poll (self, skb)
765  *
766  *    Send I(nformation) frame as primary with poll bit set
767  */
768 void irlap_send_data_primary_poll(struct irlap_cb *self, struct sk_buff *skb)
769 {
770         struct sk_buff *tx_skb;
771         int transmission_time;
772
773         /* Stop P timer */
774         del_timer(&self->poll_timer);
775
776         /* Is this reliable or unreliable data? */
777         if (skb->data[1] == I_FRAME) {
778
779                 /*
780                  *  Insert frame sequence number (Vs) in control field before
781                  *  inserting into transmit window queue.
782                  */
783                 skb->data[1] = I_FRAME | (self->vs << 1);
784
785                 /*
786                  *  Insert frame in store, in case of retransmissions
787                  *  Increase skb reference count, see irlap_do_event()
788                  */
789                 skb_get(skb);
790                 skb_queue_tail(&self->wx_list, skb);
791
792                 /* Copy buffer */
793                 tx_skb = skb_clone(skb, GFP_ATOMIC);
794                 if (tx_skb == NULL) {
795                         return;
796                 }
797
798                 /*
799                  *  Set poll bit if necessary. We do this to the copied
800                  *  skb, since retransmitted need to set or clear the poll
801                  *  bit depending on when they are sent.
802                  */
803                 tx_skb->data[1] |= PF_BIT;
804
805                 self->vs = (self->vs + 1) % 8;
806                 self->ack_required = FALSE;
807
808                 irlap_next_state(self, LAP_NRM_P);
809                 irlap_send_i_frame(self, tx_skb, CMD_FRAME);
810         } else {
811                 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __func__);
812
813                 if (self->ack_required) {
814                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
815                         irlap_next_state(self, LAP_NRM_P);
816                         irlap_send_rr_frame(self, CMD_FRAME);
817                         self->ack_required = FALSE;
818                 } else {
819                         skb->data[1] |= PF_BIT;
820                         irlap_next_state(self, LAP_NRM_P);
821                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
822                 }
823         }
824
825         /* How much time we took for transmission of all frames.
826          * We don't know, so let assume we used the full window. Jean II */
827         transmission_time = self->final_timeout;
828
829         /* Reset parameter so that we can fill next window */
830         self->window = self->window_size;
831
832 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
833         /* Remove what we have not used. Just do a prorata of the
834          * bytes left in window to window capacity.
835          * See max_line_capacities[][] in qos.c for details. Jean II */
836         transmission_time -= (self->final_timeout * self->bytes_left
837                               / self->line_capacity);
838         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);
839
840         /* We are allowed to transmit a maximum number of bytes again. */
841         self->bytes_left = self->line_capacity;
842 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
843
844         /*
845          * The network layer has a intermediate buffer between IrLAP
846          * and the IrDA driver which can contain 8 frames. So, even
847          * though IrLAP is currently sending the *last* frame of the
848          * tx-window, the driver most likely has only just started
849          * sending the *first* frame of the same tx-window.
850          * I.e. we are always at the very begining of or Tx window.
851          * Now, we are supposed to set the final timer from the end
852          * of our tx-window to let the other peer reply. So, we need
853          * to add extra time to compensate for the fact that we
854          * are really at the start of tx-window, otherwise the final timer
855          * might expire before he can answer...
856          * Jean II
857          */
858         irlap_start_final_timer(self, self->final_timeout + transmission_time);
859
860         /*
861          * The clever amongst you might ask why we do this adjustement
862          * only here, and not in all the other cases in irlap_event.c.
863          * In all those other case, we only send a very short management
864          * frame (few bytes), so the adjustement would be lost in the
865          * noise...
866          * The exception of course is irlap_resend_rejected_frame().
867          * Jean II */
868 }
869
870 /*
871  * Function irlap_send_data_secondary_final (self, skb)
872  *
873  *    Send I(nformation) frame as secondary with final bit set
874  *
875  */
876 void irlap_send_data_secondary_final(struct irlap_cb *self,
877                                      struct sk_buff *skb)
878 {
879         struct sk_buff *tx_skb = NULL;
880
881         IRDA_ASSERT(self != NULL, return;);
882         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
883         IRDA_ASSERT(skb != NULL, return;);
884
885         /* Is this reliable or unreliable data? */
886         if (skb->data[1] == I_FRAME) {
887
888                 /*
889                  *  Insert frame sequence number (Vs) in control field before
890                  *  inserting into transmit window queue.
891                  */
892                 skb->data[1] = I_FRAME | (self->vs << 1);
893
894                 /*
895                  *  Insert frame in store, in case of retransmissions
896                  *  Increase skb reference count, see irlap_do_event()
897                  */
898                 skb_get(skb);
899                 skb_queue_tail(&self->wx_list, skb);
900
901                 tx_skb = skb_clone(skb, GFP_ATOMIC);
902                 if (tx_skb == NULL) {
903                         return;
904                 }
905
906                 tx_skb->data[1] |= PF_BIT;
907
908                 self->vs = (self->vs + 1) % 8;
909                 self->ack_required = FALSE;
910
911                 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
912         } else {
913                 if (self->ack_required) {
914                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
915                         irlap_send_rr_frame(self, RSP_FRAME);
916                         self->ack_required = FALSE;
917                 } else {
918                         skb->data[1] |= PF_BIT;
919                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
920                 }
921         }
922
923         self->window = self->window_size;
924 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
925         /* We are allowed to transmit a maximum number of bytes again. */
926         self->bytes_left = self->line_capacity;
927 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
928
929         irlap_start_wd_timer(self, self->wd_timeout);
930 }
931
932 /*
933  * Function irlap_send_data_secondary (self, skb)
934  *
935  *    Send I(nformation) frame as secondary without final bit set
936  *
937  */
938 void irlap_send_data_secondary(struct irlap_cb *self, struct sk_buff *skb)
939 {
940         struct sk_buff *tx_skb = NULL;
941
942         /* Is this reliable or unreliable data? */
943         if (skb->data[1] == I_FRAME) {
944
945                 /*
946                  *  Insert frame sequence number (Vs) in control field before
947                  *  inserting into transmit window queue.
948                  */
949                 skb->data[1] = I_FRAME | (self->vs << 1);
950
951                 /*
952                  *  Insert frame in store, in case of retransmissions
953                  *  Increase skb reference count, see irlap_do_event()
954                  */
955                 skb_get(skb);
956                 skb_queue_tail(&self->wx_list, skb);
957
958                 tx_skb = skb_clone(skb, GFP_ATOMIC);
959                 if (tx_skb == NULL) {
960                         return;
961                 }
962
963                 self->vs = (self->vs + 1) % 8;
964                 self->ack_required = FALSE;
965                 self->window -= 1;
966
967                 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
968         } else {
969                 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
970                 self->window -= 1;
971         }
972 }
973
974 /*
975  * Function irlap_resend_rejected_frames (nr)
976  *
977  *    Resend frames which has not been acknowledged. Should be safe to
978  *    traverse the list without locking it since this function will only be
979  *    called from interrupt context (BH)
980  */
981 void irlap_resend_rejected_frames(struct irlap_cb *self, int command)
982 {
983         struct sk_buff *tx_skb;
984         struct sk_buff *skb;
985         int count;
986
987         IRDA_ASSERT(self != NULL, return;);
988         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
989
990         /* Initialize variables */
991         count = skb_queue_len(&self->wx_list);
992
993         /*  Resend unacknowledged frame(s) */
994         skb = skb_peek(&self->wx_list);
995         while (skb != NULL) {
996                 irlap_wait_min_turn_around(self, &self->qos_tx);
997
998                 /* We copy the skb to be retransmitted since we will have to
999                  * modify it. Cloning will confuse packet sniffers
1000                  */
1001                 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
1002                 tx_skb = skb_copy(skb, GFP_ATOMIC);
1003                 if (!tx_skb) {
1004                         IRDA_DEBUG(0, "%s(), unable to copy\n", __func__);
1005                         return;
1006                 }
1007
1008                 /* Clear old Nr field + poll bit */
1009                 tx_skb->data[1] &= 0x0f;
1010
1011                 /*
1012                  *  Set poll bit on the last frame retransmitted
1013                  */
1014                 if (count-- == 1)
1015                         tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1016                 else
1017                         tx_skb->data[1] &= ~PF_BIT; /* Clear p/f bit */
1018
1019                 irlap_send_i_frame(self, tx_skb, command);
1020
1021                 /*
1022                  *  If our skb is the last buffer in the list, then
1023                  *  we are finished, if not, move to the next sk-buffer
1024                  */
1025                 if (skb == skb_peek_tail(&self->wx_list))
1026                         skb = NULL;
1027                 else
1028                         skb = skb->next;
1029         }
1030 #if 0 /* Not yet */
1031         /*
1032          *  We can now fill the window with additional data frames
1033          */
1034         while (!skb_queue_empty(&self->txq)) {
1035
1036                 IRDA_DEBUG(0, "%s(), sending additional frames!\n", __func__);
1037                 if (self->window > 0) {
1038                         skb = skb_dequeue( &self->txq);
1039                         IRDA_ASSERT(skb != NULL, return;);
1040
1041                         /*
1042                          *  If send window > 1 then send frame with pf
1043                          *  bit cleared
1044                          */
1045                         if ((self->window > 1) &&
1046                             !skb_queue_empty(&self->txq)) {
1047                                 irlap_send_data_primary(self, skb);
1048                         } else {
1049                                 irlap_send_data_primary_poll(self, skb);
1050                         }
1051                         kfree_skb(skb);
1052                 }
1053         }
1054 #endif
1055 }
1056
1057 void irlap_resend_rejected_frame(struct irlap_cb *self, int command)
1058 {
1059         struct sk_buff *tx_skb;
1060         struct sk_buff *skb;
1061
1062         IRDA_ASSERT(self != NULL, return;);
1063         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1064
1065         /*  Resend unacknowledged frame(s) */
1066         skb = skb_peek(&self->wx_list);
1067         if (skb != NULL) {
1068                 irlap_wait_min_turn_around(self, &self->qos_tx);
1069
1070                 /* We copy the skb to be retransmitted since we will have to
1071                  * modify it. Cloning will confuse packet sniffers
1072                  */
1073                 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
1074                 tx_skb = skb_copy(skb, GFP_ATOMIC);
1075                 if (!tx_skb) {
1076                         IRDA_DEBUG(0, "%s(), unable to copy\n", __func__);
1077                         return;
1078                 }
1079
1080                 /* Clear old Nr field + poll bit */
1081                 tx_skb->data[1] &= 0x0f;
1082
1083                 /*  Set poll/final bit */
1084                 tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1085
1086                 irlap_send_i_frame(self, tx_skb, command);
1087         }
1088 }
1089
1090 /*
1091  * Function irlap_send_ui_frame (self, skb, command)
1092  *
1093  *    Contruct and transmit an Unnumbered Information (UI) frame
1094  *
1095  */
1096 void irlap_send_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1097                          __u8 caddr, int command)
1098 {
1099         IRDA_DEBUG(4, "%s()\n", __func__);
1100
1101         IRDA_ASSERT(self != NULL, return;);
1102         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1103         IRDA_ASSERT(skb != NULL, return;);
1104
1105         /* Insert connection address */
1106         skb->data[0] = caddr | ((command) ? CMD_FRAME : 0);
1107
1108         irlap_queue_xmit(self, skb);
1109 }
1110
1111 /*
1112  * Function irlap_send_i_frame (skb)
1113  *
1114  *    Contruct and transmit Information (I) frame
1115  */
1116 static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
1117                                int command)
1118 {
1119         /* Insert connection address */
1120         skb->data[0] = self->caddr;
1121         skb->data[0] |= (command) ? CMD_FRAME : 0;
1122
1123         /* Insert next to receive (Vr) */
1124         skb->data[1] |= (self->vr << 5);  /* insert nr */
1125
1126         irlap_queue_xmit(self, skb);
1127 }
1128
1129 /*
1130  * Function irlap_recv_i_frame (skb, frame)
1131  *
1132  *    Receive and parse an I (Information) frame, no harm in making it inline
1133  *    since it's called only from one single place (irlap_driver_rcv).
1134  */
1135 static inline void irlap_recv_i_frame(struct irlap_cb *self,
1136                                       struct sk_buff *skb,
1137                                       struct irlap_info *info, int command)
1138 {
1139         info->nr = skb->data[1] >> 5;          /* Next to receive */
1140         info->pf = skb->data[1] & PF_BIT;      /* Final bit */
1141         info->ns = (skb->data[1] >> 1) & 0x07; /* Next to send */
1142
1143         /* Check if this is a command or a response frame */
1144         if (command)
1145                 irlap_do_event(self, RECV_I_CMD, skb, info);
1146         else
1147                 irlap_do_event(self, RECV_I_RSP, skb, info);
1148 }
1149
1150 /*
1151  * Function irlap_recv_ui_frame (self, skb, info)
1152  *
1153  *    Receive and parse an Unnumbered Information (UI) frame
1154  *
1155  */
1156 static void irlap_recv_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1157                                 struct irlap_info *info)
1158 {
1159         IRDA_DEBUG( 4, "%s()\n", __func__);
1160
1161         info->pf = skb->data[1] & PF_BIT;      /* Final bit */
1162
1163         irlap_do_event(self, RECV_UI_FRAME, skb, info);
1164 }
1165
1166 /*
1167  * Function irlap_recv_frmr_frame (skb, frame)
1168  *
1169  *    Received Frame Reject response.
1170  *
1171  */
1172 static void irlap_recv_frmr_frame(struct irlap_cb *self, struct sk_buff *skb,
1173                                   struct irlap_info *info)
1174 {
1175         __u8 *frame;
1176         int w, x, y, z;
1177
1178         IRDA_DEBUG(0, "%s()\n", __func__);
1179
1180         IRDA_ASSERT(self != NULL, return;);
1181         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1182         IRDA_ASSERT(skb != NULL, return;);
1183         IRDA_ASSERT(info != NULL, return;);
1184
1185         if (!pskb_may_pull(skb, 4)) {
1186                 IRDA_ERROR("%s: frame too short!\n", __func__);
1187                 return;
1188         }
1189
1190         frame = skb->data;
1191
1192         info->nr = frame[2] >> 5;          /* Next to receive */
1193         info->pf = frame[2] & PF_BIT;      /* Final bit */
1194         info->ns = (frame[2] >> 1) & 0x07; /* Next to send */
1195
1196         w = frame[3] & 0x01;
1197         x = frame[3] & 0x02;
1198         y = frame[3] & 0x04;
1199         z = frame[3] & 0x08;
1200
1201         if (w) {
1202                 IRDA_DEBUG(0, "Rejected control field is undefined or not "
1203                       "implemented.\n");
1204         }
1205         if (x) {
1206                 IRDA_DEBUG(0, "Rejected control field was invalid because it "
1207                       "contained a non permitted I field.\n");
1208         }
1209         if (y) {
1210                 IRDA_DEBUG(0, "Received I field exceeded the maximum negotiated "
1211                       "for the existing connection or exceeded the maximum "
1212                       "this station supports if no connection exists.\n");
1213         }
1214         if (z) {
1215                 IRDA_DEBUG(0, "Rejected control field control field contained an "
1216                       "invalid Nr count.\n");
1217         }
1218         irlap_do_event(self, RECV_FRMR_RSP, skb, info);
1219 }
1220
1221 /*
1222  * Function irlap_send_test_frame (self, daddr)
1223  *
1224  *    Send a test frame response
1225  *
1226  */
1227 void irlap_send_test_frame(struct irlap_cb *self, __u8 caddr, __u32 daddr,
1228                            struct sk_buff *cmd)
1229 {
1230         struct sk_buff *tx_skb;
1231         struct test_frame *frame;
1232         __u8 *info;
1233
1234         tx_skb = alloc_skb(cmd->len + sizeof(struct test_frame), GFP_ATOMIC);
1235         if (!tx_skb)
1236                 return;
1237
1238         /* Broadcast frames must include saddr and daddr fields */
1239         if (caddr == CBROADCAST) {
1240                 frame = (struct test_frame *)
1241                         skb_put(tx_skb, sizeof(struct test_frame));
1242
1243                 /* Insert the swapped addresses */
1244                 frame->saddr = cpu_to_le32(self->saddr);
1245                 frame->daddr = cpu_to_le32(daddr);
1246         } else
1247                 frame = (struct test_frame *) skb_put(tx_skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);
1248
1249         frame->caddr = caddr;
1250         frame->control = TEST_RSP | PF_BIT;
1251
1252         /* Copy info */
1253         info = skb_put(tx_skb, cmd->len);
1254         memcpy(info, cmd->data, cmd->len);
1255
1256         /* Return to sender */
1257         irlap_wait_min_turn_around(self, &self->qos_tx);
1258         irlap_queue_xmit(self, tx_skb);
1259 }
1260
1261 /*
1262  * Function irlap_recv_test_frame (self, skb)
1263  *
1264  *    Receive a test frame
1265  *
1266  */
1267 static void irlap_recv_test_frame(struct irlap_cb *self, struct sk_buff *skb,
1268                                   struct irlap_info *info, int command)
1269 {
1270         struct test_frame *frame;
1271
1272         IRDA_DEBUG(2, "%s()\n", __func__);
1273
1274         if (!pskb_may_pull(skb, sizeof(*frame))) {
1275                 IRDA_ERROR("%s: frame too short!\n", __func__);
1276                 return;
1277         }
1278         frame = (struct test_frame *) skb->data;
1279
1280         /* Broadcast frames must carry saddr and daddr fields */
1281         if (info->caddr == CBROADCAST) {
1282                 if (skb->len < sizeof(struct test_frame)) {
1283                         IRDA_DEBUG(0, "%s() test frame too short!\n",
1284                                    __func__);
1285                         return;
1286                 }
1287
1288                 /* Read and swap addresses */
1289                 info->daddr = le32_to_cpu(frame->saddr);
1290                 info->saddr = le32_to_cpu(frame->daddr);
1291
1292                 /* Make sure frame is addressed to us */
1293                 if ((info->saddr != self->saddr) &&
1294                     (info->saddr != BROADCAST)) {
1295                         return;
1296                 }
1297         }
1298
1299         if (command)
1300                 irlap_do_event(self, RECV_TEST_CMD, skb, info);
1301         else
1302                 irlap_do_event(self, RECV_TEST_RSP, skb, info);
1303 }
1304
1305 /*
1306  * Function irlap_driver_rcv (skb, netdev, ptype)
1307  *
1308  *    Called when a frame is received. Dispatches the right receive function
1309  *    for processing of the frame.
1310  *
1311  * Note on skb management :
1312  * After calling the higher layers of the IrDA stack, we always
1313  * kfree() the skb, which drop the reference count (and potentially
1314  * destroy it).
1315  * If a higher layer of the stack want to keep the skb around (to put
1316  * in a queue or pass it to the higher layer), it will need to use
1317  * skb_get() to keep a reference on it. This is usually done at the
1318  * LMP level in irlmp.c.
1319  * Jean II
1320  */
1321 int irlap_driver_rcv(struct sk_buff *skb, struct net_device *dev,
1322                      struct packet_type *ptype, struct net_device *orig_dev)
1323 {
1324         struct irlap_info info;
1325         struct irlap_cb *self;
1326         int command;
1327         __u8 control;
1328
1329         if (dev_net(dev) != &init_net)
1330                 goto out;
1331
1332         /* FIXME: should we get our own field? */
1333         self = (struct irlap_cb *) dev->atalk_ptr;
1334
1335         /* If the net device is down, then IrLAP is gone! */
1336         if (!self || self->magic != LAP_MAGIC) {
1337                 dev_kfree_skb(skb);
1338                 return -1;
1339         }
1340
1341         /* We are no longer an "old" protocol, so we need to handle
1342          * share and non linear skbs. This should never happen, so
1343          * we don't need to be clever about it. Jean II */
1344         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
1345                 IRDA_ERROR("%s: can't clone shared skb!\n", __func__);
1346                 dev_kfree_skb(skb);
1347                 return -1;
1348         }
1349
1350         /* Check if frame is large enough for parsing */
1351         if (!pskb_may_pull(skb, 2)) {
1352                 IRDA_ERROR("%s: frame too short!\n", __func__);
1353                 dev_kfree_skb(skb);
1354                 return -1;
1355         }
1356
1357         command    = skb->data[0] & CMD_FRAME;
1358         info.caddr = skb->data[0] & CBROADCAST;
1359
1360         info.pf      = skb->data[1] &  PF_BIT;
1361         info.control = skb->data[1] & ~PF_BIT; /* Mask away poll/final bit */
1362
1363         control = info.control;
1364
1365         /*  First we check if this frame has a valid connection address */
1366         if ((info.caddr != self->caddr) && (info.caddr != CBROADCAST)) {
1367                 IRDA_DEBUG(0, "%s(), wrong connection address!\n",
1368                            __func__);
1369                 goto out;
1370         }
1371         /*
1372          *  Optimize for the common case and check if the frame is an
1373          *  I(nformation) frame. Only I-frames have bit 0 set to 0
1374          */
1375         if (~control & 0x01) {
1376                 irlap_recv_i_frame(self, skb, &info, command);
1377                 goto out;
1378         }
1379         /*
1380          *  We now check is the frame is an S(upervisory) frame. Only
1381          *  S-frames have bit 0 set to 1 and bit 1 set to 0
1382          */
1383         if (~control & 0x02) {
1384                 /*
1385                  *  Received S(upervisory) frame, check which frame type it is
1386                  *  only the first nibble is of interest
1387                  */
1388                 switch (control & 0x0f) {
1389                 case RR:
1390                         irlap_recv_rr_frame(self, skb, &info, command);
1391                         break;
1392                 case RNR:
1393                         irlap_recv_rnr_frame(self, skb, &info, command);
1394                         break;
1395                 case REJ:
1396                         irlap_recv_rej_frame(self, skb, &info, command);
1397                         break;
1398                 case SREJ:
1399                         irlap_recv_srej_frame(self, skb, &info, command);
1400                         break;
1401                 default:
1402                         IRDA_WARNING("%s: Unknown S-frame %02x received!\n",
1403                                 __func__, info.control);
1404                         break;
1405                 }
1406                 goto out;
1407         }
1408         /*
1409          *  This must be a C(ontrol) frame
1410          */
1411         switch (control) {
1412         case XID_RSP:
1413                 irlap_recv_discovery_xid_rsp(self, skb, &info);
1414                 break;
1415         case XID_CMD:
1416                 irlap_recv_discovery_xid_cmd(self, skb, &info);
1417                 break;
1418         case SNRM_CMD:
1419                 irlap_recv_snrm_cmd(self, skb, &info);
1420                 break;
1421         case DM_RSP:
1422                 irlap_do_event(self, RECV_DM_RSP, skb, &info);
1423                 break;
1424         case DISC_CMD: /* And RD_RSP since they have the same value */
1425                 irlap_recv_disc_frame(self, skb, &info, command);
1426                 break;
1427         case TEST_CMD:
1428                 irlap_recv_test_frame(self, skb, &info, command);
1429                 break;
1430         case UA_RSP:
1431                 irlap_recv_ua_frame(self, skb, &info);
1432                 break;
1433         case FRMR_RSP:
1434                 irlap_recv_frmr_frame(self, skb, &info);
1435                 break;
1436         case UI_FRAME:
1437                 irlap_recv_ui_frame(self, skb, &info);
1438                 break;
1439         default:
1440                 IRDA_WARNING("%s: Unknown frame %02x received!\n",
1441                                 __func__, info.control);
1442                 break;
1443         }
1444 out:
1445         /* Always drop our reference on the skb */
1446         dev_kfree_skb(skb);
1447         return 0;
1448 }