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->h.raw = skb->nh.raw = skb->mac.raw = skb->data;
  97         skb->protocol = htons(ETH_P_IRDA);
  98         skb->priority = TC_PRIO_BESTEFFORT;
  99
 100         irlap_insert_info(self, skb);
 101
 102         dev_queue_xmit(skb);
 103 }
 104
 105 /*
 106  * Function irlap_send_snrm_cmd (void)
 107  *
 108  *    Transmits a connect SNRM command frame
 109  */
 110 void irlap_send_snrm_frame(struct irlap_cb *self, struct qos_info *qos)
 111 {
 112         struct sk_buff *tx_skb;
 113         struct snrm_frame *frame;
 114         int ret;
 115
 116         IRDA_ASSERT(self != NULL, return;);
 117         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 118
 119         /* Allocate frame */
 120         tx_skb = alloc_skb(64, GFP_ATOMIC);
 121         if (!tx_skb)
 122                 return;
 123
 124         frame = (struct snrm_frame *) skb_put(tx_skb, 2);
 125
 126         /* Insert connection address field */
 127         if (qos)
 128                 frame->caddr = CMD_FRAME | CBROADCAST;
 129         else
 130                 frame->caddr = CMD_FRAME | self->caddr;
 131
 132         /* Insert control field */
 133         frame->control = SNRM_CMD | PF_BIT;
 134
 135         /*
 136          *  If we are establishing a connection then insert QoS paramerters
 137          */
 138         if (qos) {
 139                 skb_put(tx_skb, 9); /* 21 left */
 140                 frame->saddr = cpu_to_le32(self->saddr);
 141                 frame->daddr = cpu_to_le32(self->daddr);
 142
 143                 frame->ncaddr = self->caddr;
 144
 145                 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
 146                 if (ret < 0) {
 147                         dev_kfree_skb(tx_skb);
 148                         return;
 149                 }
 150         }
 151         irlap_queue_xmit(self, tx_skb);
 152 }
 153
 154 /*
 155  * Function irlap_recv_snrm_cmd (skb, info)
 156  *
 157  *    Received SNRM (Set Normal Response Mode) command frame
 158  *
 159  */
 160 static void irlap_recv_snrm_cmd(struct irlap_cb *self, struct sk_buff *skb,
 161                                 struct irlap_info *info)
 162 {
 163         struct snrm_frame *frame;
 164
 165         if (pskb_may_pull(skb,sizeof(struct snrm_frame))) {
 166                 frame = (struct snrm_frame *) skb->data;
 167
 168                 /* Copy the new connection address ignoring the C/R bit */
 169                 info->caddr = frame->ncaddr & 0xFE;
 170
 171                 /* Check if the new connection address is valid */
 172                 if ((info->caddr == 0x00) || (info->caddr == 0xfe)) {
 173                         IRDA_DEBUG(3, "%s(), invalid connection address!\n",
 174                                    __FUNCTION__);
 175                         return;
 176                 }
 177
 178                 /* Copy peer device address */
 179                 info->daddr = le32_to_cpu(frame->saddr);
 180                 info->saddr = le32_to_cpu(frame->daddr);
 181
 182                 /* Only accept if addressed directly to us */
 183                 if (info->saddr != self->saddr) {
 184                         IRDA_DEBUG(2, "%s(), not addressed to us!\n",
 185                                    __FUNCTION__);
 186                         return;
 187                 }
 188                 irlap_do_event(self, RECV_SNRM_CMD, skb, info);
 189         } else {
 190                 /* Signal that this SNRM frame does not contain and I-field */
 191                 irlap_do_event(self, RECV_SNRM_CMD, skb, NULL);
 192         }
 193 }
 194
 195 /*
 196  * Function irlap_send_ua_response_frame (qos)
 197  *
 198  *    Send UA (Unnumbered Acknowledgement) frame
 199  *
 200  */
 201 void irlap_send_ua_response_frame(struct irlap_cb *self, struct qos_info *qos)
 202 {
 203         struct sk_buff *tx_skb;
 204         struct ua_frame *frame;
 205         int ret;
 206
 207         IRDA_DEBUG(2, "%s() <%ld>\n", __FUNCTION__, jiffies);
 208
 209         IRDA_ASSERT(self != NULL, return;);
 210         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 211
 212         /* Allocate frame */
 213         tx_skb = alloc_skb(64, GFP_ATOMIC);
 214         if (!tx_skb)
 215                 return;
 216
 217         frame = (struct ua_frame *) skb_put(tx_skb, 10);
 218
 219         /* Build UA response */
 220         frame->caddr = self->caddr;
 221         frame->control = UA_RSP | PF_BIT;
 222
 223         frame->saddr = cpu_to_le32(self->saddr);
 224         frame->daddr = cpu_to_le32(self->daddr);
 225
 226         /* Should we send QoS negotiation parameters? */
 227         if (qos) {
 228                 ret = irlap_insert_qos_negotiation_params(self, tx_skb);
 229                 if (ret < 0) {
 230                         dev_kfree_skb(tx_skb);
 231                         return;
 232                 }
 233         }
 234
 235         irlap_queue_xmit(self, tx_skb);
 236 }
 237
 238
 239 /*
 240  * Function irlap_send_dm_frame (void)
 241  *
 242  *    Send disconnected mode (DM) frame
 243  *
 244  */
 245 void irlap_send_dm_frame( struct irlap_cb *self)
 246 {
 247         struct sk_buff *tx_skb = NULL;
 248         __u8 *frame;
 249
 250         IRDA_ASSERT(self != NULL, return;);
 251         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 252
 253         tx_skb = alloc_skb(32, GFP_ATOMIC);
 254         if (!tx_skb)
 255                 return;
 256
 257         frame = skb_put(tx_skb, 2);
 258
 259         if (self->state == LAP_NDM)
 260                 frame[0] = CBROADCAST;
 261         else
 262                 frame[0] = self->caddr;
 263
 264         frame[1] = DM_RSP | PF_BIT;
 265
 266         irlap_queue_xmit(self, tx_skb);
 267 }
 268
 269 /*
 270  * Function irlap_send_disc_frame (void)
 271  *
 272  *    Send disconnect (DISC) frame
 273  *
 274  */
 275 void irlap_send_disc_frame(struct irlap_cb *self)
 276 {
 277         struct sk_buff *tx_skb = NULL;
 278         __u8 *frame;
 279
 280         IRDA_DEBUG(3, "%s()\n", __FUNCTION__);
 281
 282         IRDA_ASSERT(self != NULL, return;);
 283         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 284
 285         tx_skb = alloc_skb(16, GFP_ATOMIC);
 286         if (!tx_skb)
 287                 return;
 288
 289         frame = skb_put(tx_skb, 2);
 290
 291         frame[0] = self->caddr | CMD_FRAME;
 292         frame[1] = DISC_CMD | PF_BIT;
 293
 294         irlap_queue_xmit(self, tx_skb);
 295 }
 296
 297 /*
 298  * Function irlap_send_discovery_xid_frame (S, s, command)
 299  *
 300  *    Build and transmit a XID (eXchange station IDentifier) discovery
 301  *    frame.
 302  */
 303 void irlap_send_discovery_xid_frame(struct irlap_cb *self, int S, __u8 s,
 304                                     __u8 command, discovery_t *discovery)
 305 {
 306         struct sk_buff *tx_skb = NULL;
 307         struct xid_frame *frame;
 308         __u32 bcast = BROADCAST;
 309         __u8 *info;
 310
 311         IRDA_DEBUG(4, "%s(), s=%d, S=%d, command=%d\n", __FUNCTION__,
 312                    s, S, command);
 313
 314         IRDA_ASSERT(self != NULL, return;);
 315         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 316         IRDA_ASSERT(discovery != NULL, return;);
 317
 318         tx_skb = alloc_skb(64, GFP_ATOMIC);
 319         if (!tx_skb)
 320                 return;
 321
 322         skb_put(tx_skb, 14);
 323         frame = (struct xid_frame *) tx_skb->data;
 324
 325         if (command) {
 326                 frame->caddr = CBROADCAST | CMD_FRAME;
 327                 frame->control =  XID_CMD | PF_BIT;
 328         } else {
 329                 frame->caddr = CBROADCAST;
 330                 frame->control =  XID_RSP | PF_BIT;
 331         }
 332         frame->ident = XID_FORMAT;
 333
 334         frame->saddr = cpu_to_le32(self->saddr);
 335
 336         if (command)
 337                 frame->daddr = cpu_to_le32(bcast);
 338         else
 339                 frame->daddr = cpu_to_le32(discovery->data.daddr);
 340
 341         switch (S) {
 342         case 1:
 343                 frame->flags = 0x00;
 344                 break;
 345         case 6:
 346                 frame->flags = 0x01;
 347                 break;
 348         case 8:
 349                 frame->flags = 0x02;
 350                 break;
 351         case 16:
 352                 frame->flags = 0x03;
 353                 break;
 354         default:
 355                 frame->flags = 0x02;
 356                 break;
 357         }
 358
 359         frame->slotnr = s;
 360         frame->version = 0x00;
 361
 362         /*
 363          *  Provide info for final slot only in commands, and for all
 364          *  responses. Send the second byte of the hint only if the
 365          *  EXTENSION bit is set in the first byte.
 366          */
 367         if (!command || (frame->slotnr == 0xff)) {
 368                 int len;
 369
 370                 if (discovery->data.hints[0] & HINT_EXTENSION) {
 371                         info = skb_put(tx_skb, 2);
 372                         info[0] = discovery->data.hints[0];
 373                         info[1] = discovery->data.hints[1];
 374                 } else {
 375                         info = skb_put(tx_skb, 1);
 376                         info[0] = discovery->data.hints[0];
 377                 }
 378                 info = skb_put(tx_skb, 1);
 379                 info[0] = discovery->data.charset;
 380
 381                 len = IRDA_MIN(discovery->name_len, skb_tailroom(tx_skb));
 382                 info = skb_put(tx_skb, len);
 383                 memcpy(info, discovery->data.info, len);
 384         }
 385         irlap_queue_xmit(self, tx_skb);
 386 }
 387
 388 /*
 389  * Function irlap_recv_discovery_xid_rsp (skb, info)
 390  *
 391  *    Received a XID discovery response
 392  *
 393  */
 394 static void irlap_recv_discovery_xid_rsp(struct irlap_cb *self,
 395                                          struct sk_buff *skb,
 396                                          struct irlap_info *info)
 397 {
 398         struct xid_frame *xid;
 399         discovery_t *discovery = NULL;
 400         __u8 *discovery_info;
 401         char *text;
 402
 403         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
 404
 405         IRDA_ASSERT(self != NULL, return;);
 406         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 407
 408         if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
 409                 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
 410                 return;
 411         }
 412
 413         xid = (struct xid_frame *) skb->data;
 414
 415         info->daddr = le32_to_cpu(xid->saddr);
 416         info->saddr = le32_to_cpu(xid->daddr);
 417
 418         /* Make sure frame is addressed to us */
 419         if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
 420                 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
 421                            __FUNCTION__);
 422                 return;
 423         }
 424
 425         if ((discovery = kzalloc(sizeof(discovery_t), GFP_ATOMIC)) == NULL) {
 426                 IRDA_WARNING("%s: kmalloc failed!\n", __FUNCTION__);
 427                 return;
 428         }
 429
 430         discovery->data.daddr = info->daddr;
 431         discovery->data.saddr = self->saddr;
 432         discovery->timestamp = jiffies;
 433
 434         IRDA_DEBUG(4, "%s(), daddr=%08x\n", __FUNCTION__,
 435                    discovery->data.daddr);
 436
 437         discovery_info = skb_pull(skb, sizeof(struct xid_frame));
 438
 439         /* Get info returned from peer */
 440         discovery->data.hints[0] = discovery_info[0];
 441         if (discovery_info[0] & HINT_EXTENSION) {
 442                 IRDA_DEBUG(4, "EXTENSION\n");
 443                 discovery->data.hints[1] = discovery_info[1];
 444                 discovery->data.charset = discovery_info[2];
 445                 text = (char *) &discovery_info[3];
 446         } else {
 447                 discovery->data.hints[1] = 0;
 448                 discovery->data.charset = discovery_info[1];
 449                 text = (char *) &discovery_info[2];
 450         }
 451         /*
 452          *  Terminate info string, should be safe since this is where the
 453          *  FCS bytes resides.
 454          */
 455         skb->data[skb->len] = '\0';
 456         strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
 457         discovery->name_len = strlen(discovery->data.info);
 458
 459         info->discovery = discovery;
 460
 461         irlap_do_event(self, RECV_DISCOVERY_XID_RSP, skb, info);
 462 }
 463
 464 /*
 465  * Function irlap_recv_discovery_xid_cmd (skb, info)
 466  *
 467  *    Received a XID discovery command
 468  *
 469  */
 470 static void irlap_recv_discovery_xid_cmd(struct irlap_cb *self,
 471                                          struct sk_buff *skb,
 472                                          struct irlap_info *info)
 473 {
 474         struct xid_frame *xid;
 475         discovery_t *discovery = NULL;
 476         __u8 *discovery_info;
 477         char *text;
 478
 479         if (!pskb_may_pull(skb, sizeof(struct xid_frame))) {
 480                 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
 481                 return;
 482         }
 483
 484         xid = (struct xid_frame *) skb->data;
 485
 486         info->daddr = le32_to_cpu(xid->saddr);
 487         info->saddr = le32_to_cpu(xid->daddr);
 488
 489         /* Make sure frame is addressed to us */
 490         if ((info->saddr != self->saddr) && (info->saddr != BROADCAST)) {
 491                 IRDA_DEBUG(0, "%s(), frame is not addressed to us!\n",
 492                            __FUNCTION__);
 493                 return;
 494         }
 495
 496         switch (xid->flags & 0x03) {
 497         case 0x00:
 498                 info->S = 1;
 499                 break;
 500         case 0x01:
 501                 info->S = 6;
 502                 break;
 503         case 0x02:
 504                 info->S = 8;
 505                 break;
 506         case 0x03:
 507                 info->S = 16;
 508                 break;
 509         default:
 510                 /* Error!! */
 511                 return;
 512         }
 513         info->s = xid->slotnr;
 514
 515         discovery_info = skb_pull(skb, sizeof(struct xid_frame));
 516
 517         /*
 518          *  Check if last frame
 519          */
 520         if (info->s == 0xff) {
 521                 /* Check if things are sane at this point... */
 522                 if((discovery_info == NULL) ||
 523                    !pskb_may_pull(skb, 3)) {
 524                         IRDA_ERROR("%s: discovery frame to short!\n",
 525                                    __FUNCTION__);
 526                         return;
 527                 }
 528
 529                 /*
 530                  *  We now have some discovery info to deliver!
 531                  */
 532                 discovery = kmalloc(sizeof(discovery_t), GFP_ATOMIC);
 533                 if (!discovery) {
 534                         IRDA_WARNING("%s: unable to malloc!\n", __FUNCTION__);
 535                         return;
 536                 }
 537
 538                 discovery->data.daddr = info->daddr;
 539                 discovery->data.saddr = self->saddr;
 540                 discovery->timestamp = jiffies;
 541
 542                 discovery->data.hints[0] = discovery_info[0];
 543                 if (discovery_info[0] & HINT_EXTENSION) {
 544                         discovery->data.hints[1] = discovery_info[1];
 545                         discovery->data.charset = discovery_info[2];
 546                         text = (char *) &discovery_info[3];
 547                 } else {
 548                         discovery->data.hints[1] = 0;
 549                         discovery->data.charset = discovery_info[1];
 550                         text = (char *) &discovery_info[2];
 551                 }
 552                 /*
 553                  *  Terminate string, should be safe since this is where the
 554                  *  FCS bytes resides.
 555                  */
 556                 skb->data[skb->len] = '\0';
 557                 strncpy(discovery->data.info, text, NICKNAME_MAX_LEN);
 558                 discovery->name_len = strlen(discovery->data.info);
 559
 560                 info->discovery = discovery;
 561         } else
 562                 info->discovery = NULL;
 563
 564         irlap_do_event(self, RECV_DISCOVERY_XID_CMD, skb, info);
 565 }
 566
 567 /*
 568  * Function irlap_send_rr_frame (self, command)
 569  *
 570  *    Build and transmit RR (Receive Ready) frame. Notice that it is currently
 571  *    only possible to send RR frames with the poll bit set.
 572  */
 573 void irlap_send_rr_frame(struct irlap_cb *self, int command)
 574 {
 575         struct sk_buff *tx_skb;
 576         __u8 *frame;
 577
 578         tx_skb = alloc_skb(16, GFP_ATOMIC);
 579         if (!tx_skb)
 580                 return;
 581
 582         frame = skb_put(tx_skb, 2);
 583
 584         frame[0] = self->caddr;
 585         frame[0] |= (command) ? CMD_FRAME : 0;
 586
 587         frame[1] = RR | PF_BIT | (self->vr << 5);
 588
 589         irlap_queue_xmit(self, tx_skb);
 590 }
 591
 592 /*
 593  * Function irlap_send_rd_frame (self)
 594  *
 595  *    Request disconnect. Used by a secondary station to request the
 596  *    disconnection of the link.
 597  */
 598 void irlap_send_rd_frame(struct irlap_cb *self)
 599 {
 600         struct sk_buff *tx_skb;
 601         __u8 *frame;
 602
 603         tx_skb = alloc_skb(16, GFP_ATOMIC);
 604         if (!tx_skb)
 605                 return;
 606
 607         frame = skb_put(tx_skb, 2);
 608
 609         frame[0] = self->caddr;
 610         frame[1] = RD_RSP | PF_BIT;
 611
 612         irlap_queue_xmit(self, tx_skb);
 613 }
 614
 615 /*
 616  * Function irlap_recv_rr_frame (skb, info)
 617  *
 618  *    Received RR (Receive Ready) frame from peer station, no harm in
 619  *    making it inline since its called only from one single place
 620  *    (irlap_driver_rcv).
 621  */
 622 static inline void irlap_recv_rr_frame(struct irlap_cb *self,
 623                                        struct sk_buff *skb,
 624                                        struct irlap_info *info, int command)
 625 {
 626         info->nr = skb->data[1] >> 5;
 627
 628         /* Check if this is a command or a response frame */
 629         if (command)
 630                 irlap_do_event(self, RECV_RR_CMD, skb, info);
 631         else
 632                 irlap_do_event(self, RECV_RR_RSP, skb, info);
 633 }
 634
 635 /*
 636  * Function irlap_recv_rnr_frame (self, skb, info)
 637  *
 638  *    Received RNR (Receive Not Ready) frame from peer station
 639  *
 640  */
 641 static void irlap_recv_rnr_frame(struct irlap_cb *self, struct sk_buff *skb,
 642                                  struct irlap_info *info, int command)
 643 {
 644         info->nr = skb->data[1] >> 5;
 645
 646         IRDA_DEBUG(4, "%s(), nr=%d, %ld\n", __FUNCTION__, info->nr, jiffies);
 647
 648         if (command)
 649                 irlap_do_event(self, RECV_RNR_CMD, skb, info);
 650         else
 651                 irlap_do_event(self, RECV_RNR_RSP, skb, info);
 652 }
 653
 654 static void irlap_recv_rej_frame(struct irlap_cb *self, struct sk_buff *skb,
 655                                  struct irlap_info *info, int command)
 656 {
 657         IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
 658
 659         info->nr = skb->data[1] >> 5;
 660
 661         /* Check if this is a command or a response frame */
 662         if (command)
 663                 irlap_do_event(self, RECV_REJ_CMD, skb, info);
 664         else
 665                 irlap_do_event(self, RECV_REJ_RSP, skb, info);
 666 }
 667
 668 static void irlap_recv_srej_frame(struct irlap_cb *self, struct sk_buff *skb,
 669                                   struct irlap_info *info, int command)
 670 {
 671         IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
 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_SREJ_CMD, skb, info);
 678         else
 679                 irlap_do_event(self, RECV_SREJ_RSP, skb, info);
 680 }
 681
 682 static void irlap_recv_disc_frame(struct irlap_cb *self, struct sk_buff *skb,
 683                                   struct irlap_info *info, int command)
 684 {
 685         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
 686
 687         /* Check if this is a command or a response frame */
 688         if (command)
 689                 irlap_do_event(self, RECV_DISC_CMD, skb, info);
 690         else
 691                 irlap_do_event(self, RECV_RD_RSP, skb, info);
 692 }
 693
 694 /*
 695  * Function irlap_recv_ua_frame (skb, frame)
 696  *
 697  *    Received UA (Unnumbered Acknowledgement) frame
 698  *
 699  */
 700 static inline void irlap_recv_ua_frame(struct irlap_cb *self,
 701                                        struct sk_buff *skb,
 702                                        struct irlap_info *info)
 703 {
 704         irlap_do_event(self, RECV_UA_RSP, skb, info);
 705 }
 706
 707 /*
 708  * Function irlap_send_data_primary(self, skb)
 709  *
 710  *    Send I-frames as the primary station but without the poll bit set
 711  *
 712  */
 713 void irlap_send_data_primary(struct irlap_cb *self, struct sk_buff *skb)
 714 {
 715         struct sk_buff *tx_skb;
 716
 717         if (skb->data[1] == I_FRAME) {
 718
 719                 /*
 720                  *  Insert frame sequence number (Vs) in control field before
 721                  *  inserting into transmit window queue.
 722                  */
 723                 skb->data[1] = I_FRAME | (self->vs << 1);
 724
 725                 /*
 726                  *  Insert frame in store, in case of retransmissions
 727                  *  Increase skb reference count, see irlap_do_event()
 728                  */
 729                 skb_get(skb);
 730                 skb_queue_tail(&self->wx_list, skb);
 731
 732                 /* Copy buffer */
 733                 tx_skb = skb_clone(skb, GFP_ATOMIC);
 734                 if (tx_skb == NULL) {
 735                         return;
 736                 }
 737
 738                 self->vs = (self->vs + 1) % 8;
 739                 self->ack_required = FALSE;
 740                 self->window -= 1;
 741
 742                 irlap_send_i_frame( self, tx_skb, CMD_FRAME);
 743         } else {
 744                 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__);
 745                 irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
 746                 self->window -= 1;
 747         }
 748 }
 749 /*
 750  * Function irlap_send_data_primary_poll (self, skb)
 751  *
 752  *    Send I(nformation) frame as primary with poll bit set
 753  */
 754 void irlap_send_data_primary_poll(struct irlap_cb *self, struct sk_buff *skb)
 755 {
 756         struct sk_buff *tx_skb;
 757         int transmission_time;
 758
 759         /* Stop P timer */
 760         del_timer(&self->poll_timer);
 761
 762         /* Is this reliable or unreliable data? */
 763         if (skb->data[1] == I_FRAME) {
 764
 765                 /*
 766                  *  Insert frame sequence number (Vs) in control field before
 767                  *  inserting into transmit window queue.
 768                  */
 769                 skb->data[1] = I_FRAME | (self->vs << 1);
 770
 771                 /*
 772                  *  Insert frame in store, in case of retransmissions
 773                  *  Increase skb reference count, see irlap_do_event()
 774                  */
 775                 skb_get(skb);
 776                 skb_queue_tail(&self->wx_list, skb);
 777
 778                 /* Copy buffer */
 779                 tx_skb = skb_clone(skb, GFP_ATOMIC);
 780                 if (tx_skb == NULL) {
 781                         return;
 782                 }
 783
 784                 /*
 785                  *  Set poll bit if necessary. We do this to the copied
 786                  *  skb, since retransmitted need to set or clear the poll
 787                  *  bit depending on when they are sent.
 788                  */
 789                 tx_skb->data[1] |= PF_BIT;
 790
 791                 self->vs = (self->vs + 1) % 8;
 792                 self->ack_required = FALSE;
 793
 794                 irlap_send_i_frame(self, tx_skb, CMD_FRAME);
 795         } else {
 796                 IRDA_DEBUG(4, "%s(), sending unreliable frame\n", __FUNCTION__);
 797
 798                 if (self->ack_required) {
 799                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
 800                         irlap_send_rr_frame(self, CMD_FRAME);
 801                         self->ack_required = FALSE;
 802                 } else {
 803                         skb->data[1] |= PF_BIT;
 804                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, CMD_FRAME);
 805                 }
 806         }
 807
 808         /* How much time we took for transmission of all frames.
 809          * We don't know, so let assume we used the full window. Jean II */
 810         transmission_time = self->final_timeout;
 811
 812         /* Reset parameter so that we can fill next window */
 813         self->window = self->window_size;
 814
 815 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
 816         /* Remove what we have not used. Just do a prorata of the
 817          * bytes left in window to window capacity.
 818          * See max_line_capacities[][] in qos.c for details. Jean II */
 819         transmission_time -= (self->final_timeout * self->bytes_left
 820                               / self->line_capacity);
 821         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);
 822
 823         /* We are allowed to transmit a maximum number of bytes again. */
 824         self->bytes_left = self->line_capacity;
 825 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
 826
 827         /*
 828          * The network layer has a intermediate buffer between IrLAP
 829          * and the IrDA driver which can contain 8 frames. So, even
 830          * though IrLAP is currently sending the *last* frame of the
 831          * tx-window, the driver most likely has only just started
 832          * sending the *first* frame of the same tx-window.
 833          * I.e. we are always at the very begining of or Tx window.
 834          * Now, we are supposed to set the final timer from the end
 835          * of our tx-window to let the other peer reply. So, we need
 836          * to add extra time to compensate for the fact that we
 837          * are really at the start of tx-window, otherwise the final timer
 838          * might expire before he can answer...
 839          * Jean II
 840          */
 841         irlap_start_final_timer(self, self->final_timeout + transmission_time);
 842
 843         /*
 844          * The clever amongst you might ask why we do this adjustement
 845          * only here, and not in all the other cases in irlap_event.c.
 846          * In all those other case, we only send a very short management
 847          * frame (few bytes), so the adjustement would be lost in the
 848          * noise...
 849          * The exception of course is irlap_resend_rejected_frame().
 850          * Jean II */
 851 }
 852
 853 /*
 854  * Function irlap_send_data_secondary_final (self, skb)
 855  *
 856  *    Send I(nformation) frame as secondary with final bit set
 857  *
 858  */
 859 void irlap_send_data_secondary_final(struct irlap_cb *self,
 860                                      struct sk_buff *skb)
 861 {
 862         struct sk_buff *tx_skb = NULL;
 863
 864         IRDA_ASSERT(self != NULL, return;);
 865         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 866         IRDA_ASSERT(skb != NULL, return;);
 867
 868         /* Is this reliable or unreliable data? */
 869         if (skb->data[1] == I_FRAME) {
 870
 871                 /*
 872                  *  Insert frame sequence number (Vs) in control field before
 873                  *  inserting into transmit window queue.
 874                  */
 875                 skb->data[1] = I_FRAME | (self->vs << 1);
 876
 877                 /*
 878                  *  Insert frame in store, in case of retransmissions
 879                  *  Increase skb reference count, see irlap_do_event()
 880                  */
 881                 skb_get(skb);
 882                 skb_queue_tail(&self->wx_list, skb);
 883
 884                 tx_skb = skb_clone(skb, GFP_ATOMIC);
 885                 if (tx_skb == NULL) {
 886                         return;
 887                 }
 888
 889                 tx_skb->data[1] |= PF_BIT;
 890
 891                 self->vs = (self->vs + 1) % 8;
 892                 self->ack_required = FALSE;
 893
 894                 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
 895         } else {
 896                 if (self->ack_required) {
 897                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
 898                         irlap_send_rr_frame(self, RSP_FRAME);
 899                         self->ack_required = FALSE;
 900                 } else {
 901                         skb->data[1] |= PF_BIT;
 902                         irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
 903                 }
 904         }
 905
 906         self->window = self->window_size;
 907 #ifdef CONFIG_IRDA_DYNAMIC_WINDOW
 908         /* We are allowed to transmit a maximum number of bytes again. */
 909         self->bytes_left = self->line_capacity;
 910 #endif /* CONFIG_IRDA_DYNAMIC_WINDOW */
 911
 912         irlap_start_wd_timer(self, self->wd_timeout);
 913 }
 914
 915 /*
 916  * Function irlap_send_data_secondary (self, skb)
 917  *
 918  *    Send I(nformation) frame as secondary without final bit set
 919  *
 920  */
 921 void irlap_send_data_secondary(struct irlap_cb *self, struct sk_buff *skb)
 922 {
 923         struct sk_buff *tx_skb = NULL;
 924
 925         /* Is this reliable or unreliable data? */
 926         if (skb->data[1] == I_FRAME) {
 927
 928                 /*
 929                  *  Insert frame sequence number (Vs) in control field before
 930                  *  inserting into transmit window queue.
 931                  */
 932                 skb->data[1] = I_FRAME | (self->vs << 1);
 933
 934                 /*
 935                  *  Insert frame in store, in case of retransmissions
 936                  *  Increase skb reference count, see irlap_do_event()
 937                  */
 938                 skb_get(skb);
 939                 skb_queue_tail(&self->wx_list, skb);
 940
 941                 tx_skb = skb_clone(skb, GFP_ATOMIC);
 942                 if (tx_skb == NULL) {
 943                         return;
 944                 }
 945
 946                 self->vs = (self->vs + 1) % 8;
 947                 self->ack_required = FALSE;
 948                 self->window -= 1;
 949
 950                 irlap_send_i_frame(self, tx_skb, RSP_FRAME);
 951         } else {
 952                 irlap_send_ui_frame(self, skb_get(skb), self->caddr, RSP_FRAME);
 953                 self->window -= 1;
 954         }
 955 }
 956
 957 /*
 958  * Function irlap_resend_rejected_frames (nr)
 959  *
 960  *    Resend frames which has not been acknowledged. Should be safe to
 961  *    traverse the list without locking it since this function will only be
 962  *    called from interrupt context (BH)
 963  */
 964 void irlap_resend_rejected_frames(struct irlap_cb *self, int command)
 965 {
 966         struct sk_buff *tx_skb;
 967         struct sk_buff *skb;
 968         int count;
 969
 970         IRDA_ASSERT(self != NULL, return;);
 971         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
 972
 973         /* Initialize variables */
 974         count = skb_queue_len(&self->wx_list);
 975
 976         /*  Resend unacknowledged frame(s) */
 977         skb = skb_peek(&self->wx_list);
 978         while (skb != NULL) {
 979                 irlap_wait_min_turn_around(self, &self->qos_tx);
 980
 981                 /* We copy the skb to be retransmitted since we will have to
 982                  * modify it. Cloning will confuse packet sniffers
 983                  */
 984                 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
 985                 tx_skb = skb_copy(skb, GFP_ATOMIC);
 986                 if (!tx_skb) {
 987                         IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__);
 988                         return;
 989                 }
 990
 991                 /* Clear old Nr field + poll bit */
 992                 tx_skb->data[1] &= 0x0f;
 993
 994                 /*
 995                  *  Set poll bit on the last frame retransmitted
 996                  */
 997                 if (count-- == 1)
 998                         tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
 999                 else
1000                         tx_skb->data[1] &= ~PF_BIT; /* Clear p/f bit */
1001
1002                 irlap_send_i_frame(self, tx_skb, command);
1003
1004                 /*
1005                  *  If our skb is the last buffer in the list, then
1006                  *  we are finished, if not, move to the next sk-buffer
1007                  */
1008                 if (skb == skb_peek_tail(&self->wx_list))
1009                         skb = NULL;
1010                 else
1011                         skb = skb->next;
1012         }
1013 #if 0 /* Not yet */
1014         /*
1015          *  We can now fill the window with additional data frames
1016          */
1017         while (!skb_queue_empty(&self->txq)) {
1018
1019                 IRDA_DEBUG(0, "%s(), sending additional frames!\n", __FUNCTION__);
1020                 if (self->window > 0) {
1021                         skb = skb_dequeue( &self->txq);
1022                         IRDA_ASSERT(skb != NULL, return;);
1023
1024                         /*
1025                          *  If send window > 1 then send frame with pf
1026                          *  bit cleared
1027                          */
1028                         if ((self->window > 1) &&
1029                             !skb_queue_empty(&self->txq)) {
1030                                 irlap_send_data_primary(self, skb);
1031                         } else {
1032                                 irlap_send_data_primary_poll(self, skb);
1033                         }
1034                         kfree_skb(skb);
1035                 }
1036         }
1037 #endif
1038 }
1039
1040 void irlap_resend_rejected_frame(struct irlap_cb *self, int command)
1041 {
1042         struct sk_buff *tx_skb;
1043         struct sk_buff *skb;
1044
1045         IRDA_ASSERT(self != NULL, return;);
1046         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1047
1048         /*  Resend unacknowledged frame(s) */
1049         skb = skb_peek(&self->wx_list);
1050         if (skb != NULL) {
1051                 irlap_wait_min_turn_around(self, &self->qos_tx);
1052
1053                 /* We copy the skb to be retransmitted since we will have to
1054                  * modify it. Cloning will confuse packet sniffers
1055                  */
1056                 /* tx_skb = skb_clone( skb, GFP_ATOMIC); */
1057                 tx_skb = skb_copy(skb, GFP_ATOMIC);
1058                 if (!tx_skb) {
1059                         IRDA_DEBUG(0, "%s(), unable to copy\n", __FUNCTION__);
1060                         return;
1061                 }
1062
1063                 /* Clear old Nr field + poll bit */
1064                 tx_skb->data[1] &= 0x0f;
1065
1066                 /*  Set poll/final bit */
1067                 tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
1068
1069                 irlap_send_i_frame(self, tx_skb, command);
1070         }
1071 }
1072
1073 /*
1074  * Function irlap_send_ui_frame (self, skb, command)
1075  *
1076  *    Contruct and transmit an Unnumbered Information (UI) frame
1077  *
1078  */
1079 void irlap_send_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1080                          __u8 caddr, int command)
1081 {
1082         IRDA_DEBUG(4, "%s()\n", __FUNCTION__);
1083
1084         IRDA_ASSERT(self != NULL, return;);
1085         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1086         IRDA_ASSERT(skb != NULL, return;);
1087
1088         /* Insert connection address */
1089         skb->data[0] = caddr | ((command) ? CMD_FRAME : 0);
1090
1091         irlap_queue_xmit(self, skb);
1092 }
1093
1094 /*
1095  * Function irlap_send_i_frame (skb)
1096  *
1097  *    Contruct and transmit Information (I) frame
1098  */
1099 static void irlap_send_i_frame(struct irlap_cb *self, struct sk_buff *skb,
1100                                int command)
1101 {
1102         /* Insert connection address */
1103         skb->data[0] = self->caddr;
1104         skb->data[0] |= (command) ? CMD_FRAME : 0;
1105
1106         /* Insert next to receive (Vr) */
1107         skb->data[1] |= (self->vr << 5);  /* insert nr */
1108
1109         irlap_queue_xmit(self, skb);
1110 }
1111
1112 /*
1113  * Function irlap_recv_i_frame (skb, frame)
1114  *
1115  *    Receive and parse an I (Information) frame, no harm in making it inline
1116  *    since it's called only from one single place (irlap_driver_rcv).
1117  */
1118 static inline void irlap_recv_i_frame(struct irlap_cb *self,
1119                                       struct sk_buff *skb,
1120                                       struct irlap_info *info, int command)
1121 {
1122         info->nr = skb->data[1] >> 5;          /* Next to receive */
1123         info->pf = skb->data[1] & PF_BIT;      /* Final bit */
1124         info->ns = (skb->data[1] >> 1) & 0x07; /* Next to send */
1125
1126         /* Check if this is a command or a response frame */
1127         if (command)
1128                 irlap_do_event(self, RECV_I_CMD, skb, info);
1129         else
1130                 irlap_do_event(self, RECV_I_RSP, skb, info);
1131 }
1132
1133 /*
1134  * Function irlap_recv_ui_frame (self, skb, info)
1135  *
1136  *    Receive and parse an Unnumbered Information (UI) frame
1137  *
1138  */
1139 static void irlap_recv_ui_frame(struct irlap_cb *self, struct sk_buff *skb,
1140                                 struct irlap_info *info)
1141 {
1142         IRDA_DEBUG( 4, "%s()\n", __FUNCTION__);
1143
1144         info->pf = skb->data[1] & PF_BIT;      /* Final bit */
1145
1146         irlap_do_event(self, RECV_UI_FRAME, skb, info);
1147 }
1148
1149 /*
1150  * Function irlap_recv_frmr_frame (skb, frame)
1151  *
1152  *    Received Frame Reject response.
1153  *
1154  */
1155 static void irlap_recv_frmr_frame(struct irlap_cb *self, struct sk_buff *skb,
1156                                   struct irlap_info *info)
1157 {
1158         __u8 *frame;
1159         int w, x, y, z;
1160
1161         IRDA_DEBUG(0, "%s()\n", __FUNCTION__);
1162
1163         IRDA_ASSERT(self != NULL, return;);
1164         IRDA_ASSERT(self->magic == LAP_MAGIC, return;);
1165         IRDA_ASSERT(skb != NULL, return;);
1166         IRDA_ASSERT(info != NULL, return;);
1167
1168         if (!pskb_may_pull(skb, 4)) {
1169                 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
1170                 return;
1171         }
1172
1173         frame = skb->data;
1174
1175         info->nr = frame[2] >> 5;          /* Next to receive */
1176         info->pf = frame[2] & PF_BIT;      /* Final bit */
1177         info->ns = (frame[2] >> 1) & 0x07; /* Next to send */
1178
1179         w = frame[3] & 0x01;
1180         x = frame[3] & 0x02;
1181         y = frame[3] & 0x04;
1182         z = frame[3] & 0x08;
1183
1184         if (w) {
1185                 IRDA_DEBUG(0, "Rejected control field is undefined or not "
1186                       "implemented.\n");
1187         }
1188         if (x) {
1189                 IRDA_DEBUG(0, "Rejected control field was invalid because it "
1190                       "contained a non permitted I field.\n");
1191         }
1192         if (y) {
1193                 IRDA_DEBUG(0, "Received I field exceeded the maximum negotiated "
1194                       "for the existing connection or exceeded the maximum "
1195                       "this station supports if no connection exists.\n");
1196         }
1197         if (z) {
1198                 IRDA_DEBUG(0, "Rejected control field control field contained an "
1199                       "invalid Nr count.\n");
1200         }
1201         irlap_do_event(self, RECV_FRMR_RSP, skb, info);
1202 }
1203
1204 /*
1205  * Function irlap_send_test_frame (self, daddr)
1206  *
1207  *    Send a test frame response
1208  *
1209  */
1210 void irlap_send_test_frame(struct irlap_cb *self, __u8 caddr, __u32 daddr,
1211                            struct sk_buff *cmd)
1212 {
1213         struct sk_buff *tx_skb;
1214         struct test_frame *frame;
1215         __u8 *info;
1216
1217         tx_skb = alloc_skb(cmd->len+sizeof(struct test_frame), GFP_ATOMIC);
1218         if (!tx_skb)
1219                 return;
1220
1221         /* Broadcast frames must include saddr and daddr fields */
1222         if (caddr == CBROADCAST) {
1223                 frame = (struct test_frame *)
1224                         skb_put(tx_skb, sizeof(struct test_frame));
1225
1226                 /* Insert the swapped addresses */
1227                 frame->saddr = cpu_to_le32(self->saddr);
1228                 frame->daddr = cpu_to_le32(daddr);
1229         } else
1230                 frame = (struct test_frame *) skb_put(tx_skb, LAP_ADDR_HEADER + LAP_CTRL_HEADER);
1231
1232         frame->caddr = caddr;
1233         frame->control = TEST_RSP | PF_BIT;
1234
1235         /* Copy info */
1236         info = skb_put(tx_skb, cmd->len);
1237         memcpy(info, cmd->data, cmd->len);
1238
1239         /* Return to sender */
1240         irlap_wait_min_turn_around(self, &self->qos_tx);
1241         irlap_queue_xmit(self, tx_skb);
1242 }
1243
1244 /*
1245  * Function irlap_recv_test_frame (self, skb)
1246  *
1247  *    Receive a test frame
1248  *
1249  */
1250 static void irlap_recv_test_frame(struct irlap_cb *self, struct sk_buff *skb,
1251                                   struct irlap_info *info, int command)
1252 {
1253         struct test_frame *frame;
1254
1255         IRDA_DEBUG(2, "%s()\n", __FUNCTION__);
1256
1257         if (!pskb_may_pull(skb, sizeof(*frame))) {
1258                 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
1259                 return;
1260         }
1261         frame = (struct test_frame *) skb->data;
1262
1263         /* Broadcast frames must carry saddr and daddr fields */
1264         if (info->caddr == CBROADCAST) {
1265                 if (skb->len < sizeof(struct test_frame)) {
1266                         IRDA_DEBUG(0, "%s() test frame to short!\n",
1267                                    __FUNCTION__);
1268                         return;
1269                 }
1270
1271                 /* Read and swap addresses */
1272                 info->daddr = le32_to_cpu(frame->saddr);
1273                 info->saddr = le32_to_cpu(frame->daddr);
1274
1275                 /* Make sure frame is addressed to us */
1276                 if ((info->saddr != self->saddr) &&
1277                     (info->saddr != BROADCAST)) {
1278                         return;
1279                 }
1280         }
1281
1282         if (command)
1283                 irlap_do_event(self, RECV_TEST_CMD, skb, info);
1284         else
1285                 irlap_do_event(self, RECV_TEST_RSP, skb, info);
1286 }
1287
1288 /*
1289  * Function irlap_driver_rcv (skb, netdev, ptype)
1290  *
1291  *    Called when a frame is received. Dispatches the right receive function
1292  *    for processing of the frame.
1293  *
1294  * Note on skb management :
1295  * After calling the higher layers of the IrDA stack, we always
1296  * kfree() the skb, which drop the reference count (and potentially
1297  * destroy it).
1298  * If a higher layer of the stack want to keep the skb around (to put
1299  * in a queue or pass it to the higher layer), it will need to use
1300  * skb_get() to keep a reference on it. This is usually done at the
1301  * LMP level in irlmp.c.
1302  * Jean II
1303  */
1304 int irlap_driver_rcv(struct sk_buff *skb, struct net_device *dev,
1305                      struct packet_type *ptype, struct net_device *orig_dev)
1306 {
1307         struct irlap_info info;
1308         struct irlap_cb *self;
1309         int command;
1310         __u8 control;
1311
1312         /* FIXME: should we get our own field? */
1313         self = (struct irlap_cb *) dev->atalk_ptr;
1314
1315         /* If the net device is down, then IrLAP is gone! */
1316         if (!self || self->magic != LAP_MAGIC) {
1317                 dev_kfree_skb(skb);
1318                 return -1;
1319         }
1320
1321         /* We are no longer an "old" protocol, so we need to handle
1322          * share and non linear skbs. This should never happen, so
1323          * we don't need to be clever about it. Jean II */
1324         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
1325                 IRDA_ERROR("%s: can't clone shared skb!\n", __FUNCTION__);
1326                 dev_kfree_skb(skb);
1327                 return -1;
1328         }
1329
1330         /* Check if frame is large enough for parsing */
1331         if (!pskb_may_pull(skb, 2)) {
1332                 IRDA_ERROR("%s: frame to short!\n", __FUNCTION__);
1333                 dev_kfree_skb(skb);
1334                 return -1;
1335         }
1336
1337         command    = skb->data[0] & CMD_FRAME;
1338         info.caddr = skb->data[0] & CBROADCAST;
1339
1340         info.pf      = skb->data[1] &  PF_BIT;
1341         info.control = skb->data[1] & ~PF_BIT; /* Mask away poll/final bit */
1342
1343         control = info.control;
1344
1345         /*  First we check if this frame has a valid connection address */
1346         if ((info.caddr != self->caddr) && (info.caddr != CBROADCAST)) {
1347                 IRDA_DEBUG(0, "%s(), wrong connection address!\n",
1348                            __FUNCTION__);
1349                 goto out;
1350         }
1351         /*
1352          *  Optimize for the common case and check if the frame is an
1353          *  I(nformation) frame. Only I-frames have bit 0 set to 0
1354          */
1355         if (~control & 0x01) {
1356                 irlap_recv_i_frame(self, skb, &info, command);
1357                 goto out;
1358         }
1359         /*
1360          *  We now check is the frame is an S(upervisory) frame. Only
1361          *  S-frames have bit 0 set to 1 and bit 1 set to 0
1362          */
1363         if (~control & 0x02) {
1364                 /*
1365                  *  Received S(upervisory) frame, check which frame type it is
1366                  *  only the first nibble is of interest
1367                  */
1368                 switch (control & 0x0f) {
1369                 case RR:
1370                         irlap_recv_rr_frame(self, skb, &info, command);
1371                         break;
1372                 case RNR:
1373                         irlap_recv_rnr_frame(self, skb, &info, command);
1374                         break;
1375                 case REJ:
1376                         irlap_recv_rej_frame(self, skb, &info, command);
1377                         break;
1378                 case SREJ:
1379                         irlap_recv_srej_frame(self, skb, &info, command);
1380                         break;
1381                 default:
1382                         IRDA_WARNING("%s: Unknown S-frame %02x received!\n",
1383                                 __FUNCTION__, info.control);
1384                         break;
1385                 }
1386                 goto out;
1387         }
1388         /*
1389          *  This must be a C(ontrol) frame
1390          */
1391         switch (control) {
1392         case XID_RSP:
1393                 irlap_recv_discovery_xid_rsp(self, skb, &info);
1394                 break;
1395         case XID_CMD:
1396                 irlap_recv_discovery_xid_cmd(self, skb, &info);
1397                 break;
1398         case SNRM_CMD:
1399                 irlap_recv_snrm_cmd(self, skb, &info);
1400                 break;
1401         case DM_RSP:
1402                 irlap_do_event(self, RECV_DM_RSP, skb, &info);
1403                 break;
1404         case DISC_CMD: /* And RD_RSP since they have the same value */
1405                 irlap_recv_disc_frame(self, skb, &info, command);
1406                 break;
1407         case TEST_CMD:
1408                 irlap_recv_test_frame(self, skb, &info, command);
1409                 break;
1410         case UA_RSP:
1411                 irlap_recv_ua_frame(self, skb, &info);
1412                 break;
1413         case FRMR_RSP:
1414                 irlap_recv_frmr_frame(self, skb, &info);
1415                 break;
1416         case UI_FRAME:
1417                 irlap_recv_ui_frame(self, skb, &info);
1418                 break;
1419         default:
1420                 IRDA_WARNING("%s: Unknown frame %02x received!\n",
1421                                 __FUNCTION__, info.control);
1422                 break;
1423         }
1424 out:
1425         /* Always drop our reference on the skb */
1426         dev_kfree_skb(skb);
1427         return 0;
1428 }