net/irda/irnet/irnet_ppp.c

   1 /*
   2  *      IrNET protocol module : Synchronous PPP over an IrDA socket.
   3  *
   4  *              Jean II - HPL `00 - <jt@hpl.hp.com>
   5  *
   6  * This file implement the PPP interface and /dev/irnet character device.
   7  * The PPP interface hook to the ppp_generic module, handle all our
   8  *      relationship to the PPP code in the kernel (and by extension to pppd),
   9  *      and exchange PPP frames with this module (send/receive).
  10  * The /dev/irnet device is used primarily for 2 functions :
  11  *      1) as a stub for pppd (the ppp daemon), so that we can appropriately
  12  *      generate PPP sessions (we pretend we are a tty).
  13  *      2) as a control channel (write commands, read events)
  14  */
  15
  16 #include "irnet_ppp.h"          /* Private header */
  17 /* Please put other headers in irnet.h - Thanks */
  18
  19 /* Generic PPP callbacks (to call us) */
  20 static struct ppp_channel_ops irnet_ppp_ops = {
  21         .start_xmit = ppp_irnet_send,
  22         .ioctl = ppp_irnet_ioctl
  23 };
  24
  25 /************************* CONTROL CHANNEL *************************/
  26 /*
  27  * When a pppd instance is not active on /dev/irnet, it acts as a control
  28  * channel.
  29  * Writing allow to set up the IrDA destination of the IrNET channel,
  30  * and any application may be read events happening in IrNET...
  31  */
  32
  33 /*------------------------------------------------------------------*/
  34 /*
  35  * Write is used to send a command to configure a IrNET channel
  36  * before it is open by pppd. The syntax is : "command argument"
  37  * Currently there is only two defined commands :
  38  *      o name : set the requested IrDA nickname of the IrNET peer.
  39  *      o addr : set the requested IrDA address of the IrNET peer.
  40  * Note : the code is crude, but effective...
  41  */
  42 static inline ssize_t
  43 irnet_ctrl_write(irnet_socket * ap,
  44                  const char __user *buf,
  45                  size_t         count)
  46 {
  47   char          command[IRNET_MAX_COMMAND];
  48   char *        start;          /* Current command being processed */
  49   char *        next;           /* Next command to process */
  50   int           length;         /* Length of current command */
  51
  52   DENTER(CTRL_TRACE, "(ap=0x%p, count=%Zd)\n", ap, count);
  53
  54   /* Check for overflow... */
  55   DABORT(count >= IRNET_MAX_COMMAND, -ENOMEM,
  56          CTRL_ERROR, "Too much data !!!\n");
  57
  58   /* Get the data in the driver */
  59   if(copy_from_user(command, buf, count))
  60     {
  61       DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
  62       return -EFAULT;
  63     }
  64
  65   /* Safe terminate the string */
  66   command[count] = '\0';
  67   DEBUG(CTRL_INFO, "Command line received is ``%s'' (%Zd).\n",
  68         command, count);
  69
  70   /* Check every commands in the command line */
  71   next = command;
  72   while(next != NULL)
  73     {
  74       /* Look at the next command */
  75       start = next;
  76
  77       /* Scrap whitespaces before the command */
  78       while(isspace(*start))
  79         start++;
  80
  81       /* ',' is our command separator */
  82       next = strchr(start, ',');
  83       if(next)
  84         {
  85           *next = '\0';                 /* Terminate command */
  86           length = next - start;        /* Length */
  87           next++;                       /* Skip the '\0' */
  88         }
  89       else
  90         length = strlen(start);
  91
  92       DEBUG(CTRL_INFO, "Found command ``%s'' (%d).\n", start, length);
  93
  94       /* Check if we recognised one of the known command
  95        * We can't use "switch" with strings, so hack with "continue" */
  96
  97       /* First command : name -> Requested IrDA nickname */
  98       if(!strncmp(start, "name", 4))
  99         {
 100           /* Copy the name only if is included and not "any" */
 101           if((length > 5) && (strcmp(start + 5, "any")))
 102             {
 103               /* Strip out trailing whitespaces */
 104               while(isspace(start[length - 1]))
 105                 length--;
 106
 107               /* Copy the name for later reuse */
 108               memcpy(ap->rname, start + 5, length - 5);
 109               ap->rname[length - 5] = '\0';
 110             }
 111           else
 112             ap->rname[0] = '\0';
 113           DEBUG(CTRL_INFO, "Got rname = ``%s''\n", ap->rname);
 114
 115           /* Restart the loop */
 116           continue;
 117         }
 118
 119       /* Second command : addr, daddr -> Requested IrDA destination address
 120        * Also process : saddr -> Requested IrDA source address */
 121       if((!strncmp(start, "addr", 4)) ||
 122          (!strncmp(start, "daddr", 5)) ||
 123          (!strncmp(start, "saddr", 5)))
 124         {
 125           __u32         addr = DEV_ADDR_ANY;
 126
 127           /* Copy the address only if is included and not "any" */
 128           if((length > 5) && (strcmp(start + 5, "any")))
 129             {
 130               char *    begp = start + 5;
 131               char *    endp;
 132
 133               /* Scrap whitespaces before the command */
 134               while(isspace(*begp))
 135                 begp++;
 136
 137               /* Convert argument to a number (last arg is the base) */
 138               addr = simple_strtoul(begp, &endp, 16);
 139               /* Has it worked  ? (endp should be start + length) */
 140               DABORT(endp <= (start + 5), -EINVAL,
 141                      CTRL_ERROR, "Invalid address.\n");
 142             }
 143           /* Which type of address ? */
 144           if(start[0] == 's')
 145             {
 146               /* Save it */
 147               ap->rsaddr = addr;
 148               DEBUG(CTRL_INFO, "Got rsaddr = %08x\n", ap->rsaddr);
 149             }
 150           else
 151             {
 152               /* Save it */
 153               ap->rdaddr = addr;
 154               DEBUG(CTRL_INFO, "Got rdaddr = %08x\n", ap->rdaddr);
 155             }
 156
 157           /* Restart the loop */
 158           continue;
 159         }
 160
 161       /* Other possible command : connect N (number of retries) */
 162
 163       /* No command matched -> Failed... */
 164       DABORT(1, -EINVAL, CTRL_ERROR, "Not a recognised IrNET command.\n");
 165     }
 166
 167   /* Success : we have parsed all commands successfully */
 168   return(count);
 169 }
 170
 171 #ifdef INITIAL_DISCOVERY
 172 /*------------------------------------------------------------------*/
 173 /*
 174  * Function irnet_get_discovery_log (self)
 175  *
 176  *    Query the content on the discovery log if not done
 177  *
 178  * This function query the current content of the discovery log
 179  * at the startup of the event channel and save it in the internal struct.
 180  */
 181 static void
 182 irnet_get_discovery_log(irnet_socket *  ap)
 183 {
 184   __u16         mask = irlmp_service_to_hint(S_LAN);
 185
 186   /* Ask IrLMP for the current discovery log */
 187   ap->discoveries = irlmp_get_discoveries(&ap->disco_number, mask,
 188                                           DISCOVERY_DEFAULT_SLOTS);
 189
 190   /* Check if the we got some results */
 191   if(ap->discoveries == NULL)
 192     ap->disco_number = -1;
 193
 194   DEBUG(CTRL_INFO, "Got the log (0x%p), size is %d\n",
 195         ap->discoveries, ap->disco_number);
 196 }
 197
 198 /*------------------------------------------------------------------*/
 199 /*
 200  * Function irnet_read_discovery_log (self, event)
 201  *
 202  *    Read the content on the discovery log
 203  *
 204  * This function dump the current content of the discovery log
 205  * at the startup of the event channel.
 206  * Return 1 if wrote an event on the control channel...
 207  *
 208  * State of the ap->disco_XXX variables :
 209  * Socket creation :  discoveries = NULL ; disco_index = 0 ; disco_number = 0
 210  * While reading :    discoveries = ptr  ; disco_index = X ; disco_number = Y
 211  * After reading :    discoveries = NULL ; disco_index = Y ; disco_number = -1
 212  */
 213 static inline int
 214 irnet_read_discovery_log(irnet_socket * ap,
 215                          char *         event)
 216 {
 217   int           done_event = 0;
 218
 219   DENTER(CTRL_TRACE, "(ap=0x%p, event=0x%p)\n",
 220          ap, event);
 221
 222   /* Test if we have some work to do or we have already finished */
 223   if(ap->disco_number == -1)
 224     {
 225       DEBUG(CTRL_INFO, "Already done\n");
 226       return 0;
 227     }
 228
 229   /* Test if it's the first time and therefore we need to get the log */
 230   if(ap->discoveries == NULL)
 231     irnet_get_discovery_log(ap);
 232
 233   /* Check if we have more item to dump */
 234   if(ap->disco_index < ap->disco_number)
 235     {
 236       /* Write an event */
 237       sprintf(event, "Found %08x (%s) behind %08x {hints %02X-%02X}\n",
 238               ap->discoveries[ap->disco_index].daddr,
 239               ap->discoveries[ap->disco_index].info,
 240               ap->discoveries[ap->disco_index].saddr,
 241               ap->discoveries[ap->disco_index].hints[0],
 242               ap->discoveries[ap->disco_index].hints[1]);
 243       DEBUG(CTRL_INFO, "Writing discovery %d : %s\n",
 244             ap->disco_index, ap->discoveries[ap->disco_index].info);
 245
 246       /* We have an event */
 247       done_event = 1;
 248       /* Next discovery */
 249       ap->disco_index++;
 250     }
 251
 252   /* Check if we have done the last item */
 253   if(ap->disco_index >= ap->disco_number)
 254     {
 255       /* No more items : remove the log and signal termination */
 256       DEBUG(CTRL_INFO, "Cleaning up log (0x%p)\n",
 257             ap->discoveries);
 258       if(ap->discoveries != NULL)
 259         {
 260           /* Cleanup our copy of the discovery log */
 261           kfree(ap->discoveries);
 262           ap->discoveries = NULL;
 263         }
 264       ap->disco_number = -1;
 265     }
 266
 267   return done_event;
 268 }
 269 #endif /* INITIAL_DISCOVERY */
 270
 271 /*------------------------------------------------------------------*/
 272 /*
 273  * Read is used to get IrNET events
 274  */
 275 static inline ssize_t
 276 irnet_ctrl_read(irnet_socket *  ap,
 277                 struct file *   file,
 278                 char __user *   buf,
 279                 size_t          count)
 280 {
 281   DECLARE_WAITQUEUE(wait, current);
 282   char          event[64];      /* Max event is 61 char */
 283   ssize_t       ret = 0;
 284
 285   DENTER(CTRL_TRACE, "(ap=0x%p, count=%Zd)\n", ap, count);
 286
 287   /* Check if we can write an event out in one go */
 288   DABORT(count < sizeof(event), -EOVERFLOW, CTRL_ERROR, "Buffer to small.\n");
 289
 290 #ifdef INITIAL_DISCOVERY
 291   /* Check if we have read the log */
 292   if(irnet_read_discovery_log(ap, event))
 293     {
 294       /* We have an event !!! Copy it to the user */
 295       if(copy_to_user(buf, event, strlen(event)))
 296         {
 297           DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
 298           return -EFAULT;
 299         }
 300
 301       DEXIT(CTRL_TRACE, "\n");
 302       return(strlen(event));
 303     }
 304 #endif /* INITIAL_DISCOVERY */
 305
 306   /* Put ourselves on the wait queue to be woken up */
 307   add_wait_queue(&irnet_events.rwait, &wait);
 308   current->state = TASK_INTERRUPTIBLE;
 309   for(;;)
 310     {
 311       /* If there is unread events */
 312       ret = 0;
 313       if(ap->event_index != irnet_events.index)
 314         break;
 315       ret = -EAGAIN;
 316       if(file->f_flags & O_NONBLOCK)
 317         break;
 318       ret = -ERESTARTSYS;
 319       if(signal_pending(current))
 320         break;
 321       /* Yield and wait to be woken up */
 322       schedule();
 323     }
 324   current->state = TASK_RUNNING;
 325   remove_wait_queue(&irnet_events.rwait, &wait);
 326
 327   /* Did we got it ? */
 328   if(ret != 0)
 329     {
 330       /* No, return the error code */
 331       DEXIT(CTRL_TRACE, " - ret %Zd\n", ret);
 332       return ret;
 333     }
 334
 335   /* Which event is it ? */
 336   switch(irnet_events.log[ap->event_index].event)
 337     {
 338     case IRNET_DISCOVER:
 339       sprintf(event, "Discovered %08x (%s) behind %08x {hints %02X-%02X}\n",
 340               irnet_events.log[ap->event_index].daddr,
 341               irnet_events.log[ap->event_index].name,
 342               irnet_events.log[ap->event_index].saddr,
 343               irnet_events.log[ap->event_index].hints.byte[0],
 344               irnet_events.log[ap->event_index].hints.byte[1]);
 345       break;
 346     case IRNET_EXPIRE:
 347       sprintf(event, "Expired %08x (%s) behind %08x {hints %02X-%02X}\n",
 348               irnet_events.log[ap->event_index].daddr,
 349               irnet_events.log[ap->event_index].name,
 350               irnet_events.log[ap->event_index].saddr,
 351               irnet_events.log[ap->event_index].hints.byte[0],
 352               irnet_events.log[ap->event_index].hints.byte[1]);
 353       break;
 354     case IRNET_CONNECT_TO:
 355       sprintf(event, "Connected to %08x (%s) on ppp%d\n",
 356               irnet_events.log[ap->event_index].daddr,
 357               irnet_events.log[ap->event_index].name,
 358               irnet_events.log[ap->event_index].unit);
 359       break;
 360     case IRNET_CONNECT_FROM:
 361       sprintf(event, "Connection from %08x (%s) on ppp%d\n",
 362               irnet_events.log[ap->event_index].daddr,
 363               irnet_events.log[ap->event_index].name,
 364               irnet_events.log[ap->event_index].unit);
 365       break;
 366     case IRNET_REQUEST_FROM:
 367       sprintf(event, "Request from %08x (%s) behind %08x\n",
 368               irnet_events.log[ap->event_index].daddr,
 369               irnet_events.log[ap->event_index].name,
 370               irnet_events.log[ap->event_index].saddr);
 371       break;
 372     case IRNET_NOANSWER_FROM:
 373       sprintf(event, "No-answer from %08x (%s) on ppp%d\n",
 374               irnet_events.log[ap->event_index].daddr,
 375               irnet_events.log[ap->event_index].name,
 376               irnet_events.log[ap->event_index].unit);
 377       break;
 378     case IRNET_BLOCKED_LINK:
 379       sprintf(event, "Blocked link with %08x (%s) on ppp%d\n",
 380               irnet_events.log[ap->event_index].daddr,
 381               irnet_events.log[ap->event_index].name,
 382               irnet_events.log[ap->event_index].unit);
 383       break;
 384     case IRNET_DISCONNECT_FROM:
 385       sprintf(event, "Disconnection from %08x (%s) on ppp%d\n",
 386               irnet_events.log[ap->event_index].daddr,
 387               irnet_events.log[ap->event_index].name,
 388               irnet_events.log[ap->event_index].unit);
 389       break;
 390     case IRNET_DISCONNECT_TO:
 391       sprintf(event, "Disconnected to %08x (%s)\n",
 392               irnet_events.log[ap->event_index].daddr,
 393               irnet_events.log[ap->event_index].name);
 394       break;
 395     default:
 396       sprintf(event, "Bug\n");
 397     }
 398   /* Increment our event index */
 399   ap->event_index = (ap->event_index + 1) % IRNET_MAX_EVENTS;
 400
 401   DEBUG(CTRL_INFO, "Event is :%s", event);
 402
 403   /* Copy it to the user */
 404   if(copy_to_user(buf, event, strlen(event)))
 405     {
 406       DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
 407       return -EFAULT;
 408     }
 409
 410   DEXIT(CTRL_TRACE, "\n");
 411   return(strlen(event));
 412 }
 413
 414 /*------------------------------------------------------------------*/
 415 /*
 416  * Poll : called when someone do a select on /dev/irnet.
 417  * Just check if there are new events...
 418  */
 419 static inline unsigned int
 420 irnet_ctrl_poll(irnet_socket *  ap,
 421                 struct file *   file,
 422                 poll_table *    wait)
 423 {
 424   unsigned int mask;
 425
 426   DENTER(CTRL_TRACE, "(ap=0x%p)\n", ap);
 427
 428   poll_wait(file, &irnet_events.rwait, wait);
 429   mask = POLLOUT | POLLWRNORM;
 430   /* If there is unread events */
 431   if(ap->event_index != irnet_events.index)
 432     mask |= POLLIN | POLLRDNORM;
 433 #ifdef INITIAL_DISCOVERY
 434   if(ap->disco_number != -1)
 435     {
 436       /* Test if it's the first time and therefore we need to get the log */
 437       if(ap->discoveries == NULL)
 438         irnet_get_discovery_log(ap);
 439       /* Recheck */
 440       if(ap->disco_number != -1)
 441         mask |= POLLIN | POLLRDNORM;
 442     }
 443 #endif /* INITIAL_DISCOVERY */
 444
 445   DEXIT(CTRL_TRACE, " - mask=0x%X\n", mask);
 446   return mask;
 447 }
 448
 449
 450 /*********************** FILESYSTEM CALLBACKS ***********************/
 451 /*
 452  * Implement the usual open, read, write functions that will be called
 453  * by the file system when some action is performed on /dev/irnet.
 454  * Most of those actions will in fact be performed by "pppd" or
 455  * the control channel, we just act as a redirector...
 456  */
 457
 458 /*------------------------------------------------------------------*/
 459 /*
 460  * Open : when somebody open /dev/irnet
 461  * We basically create a new instance of irnet and initialise it.
 462  */
 463 static int
 464 dev_irnet_open(struct inode *   inode,
 465                struct file *    file)
 466 {
 467   struct irnet_socket * ap;
 468   int                   err;
 469
 470   DENTER(FS_TRACE, "(file=0x%p)\n", file);
 471
 472 #ifdef SECURE_DEVIRNET
 473   /* This could (should?) be enforced by the permissions on /dev/irnet. */
 474   if(!capable(CAP_NET_ADMIN))
 475     return -EPERM;
 476 #endif /* SECURE_DEVIRNET */
 477
 478   /* Allocate a private structure for this IrNET instance */
 479   ap = kzalloc(sizeof(*ap), GFP_KERNEL);
 480   DABORT(ap == NULL, -ENOMEM, FS_ERROR, "Can't allocate struct irnet...\n");
 481
 482   /* initialize the irnet structure */
 483   ap->file = file;
 484
 485   /* PPP channel setup */
 486   ap->ppp_open = 0;
 487   ap->chan.private = ap;
 488   ap->chan.ops = &irnet_ppp_ops;
 489   ap->chan.mtu = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
 490   ap->chan.hdrlen = 2 + TTP_MAX_HEADER;         /* for A/C + Max IrDA hdr */
 491   /* PPP parameters */
 492   ap->mru = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
 493   ap->xaccm[0] = ~0U;
 494   ap->xaccm[3] = 0x60000000U;
 495   ap->raccm = ~0U;
 496
 497   /* Setup the IrDA part... */
 498   err = irda_irnet_create(ap);
 499   if(err)
 500     {
 501       DERROR(FS_ERROR, "Can't setup IrDA link...\n");
 502       kfree(ap);
 503       return err;
 504     }
 505
 506   /* For the control channel */
 507   ap->event_index = irnet_events.index; /* Cancel all past events */
 508
 509   /* Put our stuff where we will be able to find it later */
 510   file->private_data = ap;
 511
 512   DEXIT(FS_TRACE, " - ap=0x%p\n", ap);
 513   return 0;
 514 }
 515
 516
 517 /*------------------------------------------------------------------*/
 518 /*
 519  * Close : when somebody close /dev/irnet
 520  * Destroy the instance of /dev/irnet
 521  */
 522 static int
 523 dev_irnet_close(struct inode *  inode,
 524                 struct file *   file)
 525 {
 526   irnet_socket *        ap = (struct irnet_socket *) file->private_data;
 527
 528   DENTER(FS_TRACE, "(file=0x%p, ap=0x%p)\n",
 529          file, ap);
 530   DABORT(ap == NULL, 0, FS_ERROR, "ap is NULL !!!\n");
 531
 532   /* Detach ourselves */
 533   file->private_data = NULL;
 534
 535   /* Close IrDA stuff */
 536   irda_irnet_destroy(ap);
 537
 538   /* Disconnect from the generic PPP layer if not already done */
 539   if(ap->ppp_open)
 540     {
 541       DERROR(FS_ERROR, "Channel still registered - deregistering !\n");
 542       ap->ppp_open = 0;
 543       ppp_unregister_channel(&ap->chan);
 544     }
 545
 546   kfree(ap);
 547
 548   DEXIT(FS_TRACE, "\n");
 549   return 0;
 550 }
 551
 552 /*------------------------------------------------------------------*/
 553 /*
 554  * Write does nothing.
 555  * (we receive packet from ppp_generic through ppp_irnet_send())
 556  */
 557 static ssize_t
 558 dev_irnet_write(struct file *   file,
 559                 const char __user *buf,
 560                 size_t          count,
 561                 loff_t *        ppos)
 562 {
 563   irnet_socket *        ap = (struct irnet_socket *) file->private_data;
 564
 565   DPASS(FS_TRACE, "(file=0x%p, ap=0x%p, count=%Zd)\n",
 566         file, ap, count);
 567   DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");
 568
 569   /* If we are connected to ppp_generic, let it handle the job */
 570   if(ap->ppp_open)
 571     return -EAGAIN;
 572   else
 573     return irnet_ctrl_write(ap, buf, count);
 574 }
 575
 576 /*------------------------------------------------------------------*/
 577 /*
 578  * Read doesn't do much either.
 579  * (pppd poll us, but ultimately reads through /dev/ppp)
 580  */
 581 static ssize_t
 582 dev_irnet_read(struct file *    file,
 583                char __user *    buf,
 584                size_t           count,
 585                loff_t *         ppos)
 586 {
 587   irnet_socket *        ap = (struct irnet_socket *) file->private_data;
 588
 589   DPASS(FS_TRACE, "(file=0x%p, ap=0x%p, count=%Zd)\n",
 590         file, ap, count);
 591   DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");
 592
 593   /* If we are connected to ppp_generic, let it handle the job */
 594   if(ap->ppp_open)
 595     return -EAGAIN;
 596   else
 597     return irnet_ctrl_read(ap, file, buf, count);
 598 }
 599
 600 /*------------------------------------------------------------------*/
 601 /*
 602  * Poll : called when someone do a select on /dev/irnet
 603  */
 604 static unsigned int
 605 dev_irnet_poll(struct file *    file,
 606                poll_table *     wait)
 607 {
 608   irnet_socket *        ap = (struct irnet_socket *) file->private_data;
 609   unsigned int          mask;
 610
 611   DENTER(FS_TRACE, "(file=0x%p, ap=0x%p)\n",
 612          file, ap);
 613
 614   mask = POLLOUT | POLLWRNORM;
 615   DABORT(ap == NULL, mask, FS_ERROR, "ap is NULL !!!\n");
 616
 617   /* If we are connected to ppp_generic, let it handle the job */
 618   if(!ap->ppp_open)
 619     mask |= irnet_ctrl_poll(ap, file, wait);
 620
 621   DEXIT(FS_TRACE, " - mask=0x%X\n", mask);
 622   return(mask);
 623 }
 624
 625 /*------------------------------------------------------------------*/
 626 /*
 627  * IOCtl : Called when someone does some ioctls on /dev/irnet
 628  * This is the way pppd configure us and control us while the PPP
 629  * instance is active.
 630  */
 631 static int
 632 dev_irnet_ioctl(struct inode *  inode,
 633                 struct file *   file,
 634                 unsigned int    cmd,
 635                 unsigned long   arg)
 636 {
 637   irnet_socket *        ap = (struct irnet_socket *) file->private_data;
 638   int                   err;
 639   int                   val;
 640   void __user *argp = (void __user *)arg;
 641
 642   DENTER(FS_TRACE, "(file=0x%p, ap=0x%p, cmd=0x%X)\n",
 643          file, ap, cmd);
 644
 645   /* Basic checks... */
 646   DASSERT(ap != NULL, -ENXIO, PPP_ERROR, "ap is NULL...\n");
 647 #ifdef SECURE_DEVIRNET
 648   if(!capable(CAP_NET_ADMIN))
 649     return -EPERM;
 650 #endif /* SECURE_DEVIRNET */
 651
 652   err = -EFAULT;
 653   switch(cmd)
 654     {
 655       /* Set discipline (should be N_SYNC_PPP or N_TTY) */
 656     case TIOCSETD:
 657       if(get_user(val, (int __user *)argp))
 658         break;
 659       if((val == N_SYNC_PPP) || (val == N_PPP))
 660         {
 661           DEBUG(FS_INFO, "Entering PPP discipline.\n");
 662           /* PPP channel setup (ap->chan in configued in dev_irnet_open())*/
 663           err = ppp_register_channel(&ap->chan);
 664           if(err == 0)
 665             {
 666               /* Our ppp side is active */
 667               ap->ppp_open = 1;
 668
 669               DEBUG(FS_INFO, "Trying to establish a connection.\n");
 670               /* Setup the IrDA link now - may fail... */
 671               irda_irnet_connect(ap);
 672             }
 673           else
 674             DERROR(FS_ERROR, "Can't setup PPP channel...\n");
 675         }
 676       else
 677         {
 678           /* In theory, should be N_TTY */
 679           DEBUG(FS_INFO, "Exiting PPP discipline.\n");
 680           /* Disconnect from the generic PPP layer */
 681           if(ap->ppp_open)
 682             {
 683               ap->ppp_open = 0;
 684               ppp_unregister_channel(&ap->chan);
 685             }
 686           else
 687             DERROR(FS_ERROR, "Channel not registered !\n");
 688           err = 0;
 689         }
 690       break;
 691
 692       /* Query PPP channel and unit number */
 693     case PPPIOCGCHAN:
 694       if(!ap->ppp_open)
 695         break;
 696       if(put_user(ppp_channel_index(&ap->chan), (int __user *)argp))
 697         break;
 698       DEBUG(FS_INFO, "Query channel.\n");
 699       err = 0;
 700       break;
 701     case PPPIOCGUNIT:
 702       if(!ap->ppp_open)
 703         break;
 704       if(put_user(ppp_unit_number(&ap->chan), (int __user *)argp))
 705         break;
 706       DEBUG(FS_INFO, "Query unit number.\n");
 707       err = 0;
 708       break;
 709
 710       /* All these ioctls can be passed both directly and from ppp_generic,
 711        * so we just deal with them in one place...
 712        */
 713     case PPPIOCGFLAGS:
 714     case PPPIOCSFLAGS:
 715     case PPPIOCGASYNCMAP:
 716     case PPPIOCSASYNCMAP:
 717     case PPPIOCGRASYNCMAP:
 718     case PPPIOCSRASYNCMAP:
 719     case PPPIOCGXASYNCMAP:
 720     case PPPIOCSXASYNCMAP:
 721     case PPPIOCGMRU:
 722     case PPPIOCSMRU:
 723       DEBUG(FS_INFO, "Standard PPP ioctl.\n");
 724       if(!capable(CAP_NET_ADMIN))
 725         err = -EPERM;
 726       else
 727         err = ppp_irnet_ioctl(&ap->chan, cmd, arg);
 728       break;
 729
 730       /* TTY IOCTLs : Pretend that we are a tty, to keep pppd happy */
 731       /* Get termios */
 732     case TCGETS:
 733       DEBUG(FS_INFO, "Get termios.\n");
 734 #ifndef TCGETS2
 735       if(kernel_termios_to_user_termios((struct termios __user *)argp, &ap->termios))
 736         break;
 737 #else
 738       if(kernel_termios_to_user_termios_1((struct termios __user *)argp, &ap->termios))
 739         break;
 740 #endif
 741       err = 0;
 742       break;
 743       /* Set termios */
 744     case TCSETSF:
 745       DEBUG(FS_INFO, "Set termios.\n");
 746 #ifndef TCGETS2
 747       if(user_termios_to_kernel_termios(&ap->termios, (struct termios __user *)argp))
 748         break;
 749 #else
 750       if(user_termios_to_kernel_termios_1(&ap->termios, (struct termios __user *)argp))
 751         break;
 752 #endif
 753       err = 0;
 754       break;
 755
 756       /* Set DTR/RTS */
 757     case TIOCMBIS:
 758     case TIOCMBIC:
 759       /* Set exclusive/non-exclusive mode */
 760     case TIOCEXCL:
 761     case TIOCNXCL:
 762       DEBUG(FS_INFO, "TTY compatibility.\n");
 763       err = 0;
 764       break;
 765
 766     case TCGETA:
 767       DEBUG(FS_INFO, "TCGETA\n");
 768       break;
 769
 770     case TCFLSH:
 771       DEBUG(FS_INFO, "TCFLSH\n");
 772       /* Note : this will flush buffers in PPP, so it *must* be done
 773        * We should also worry that we don't accept junk here and that
 774        * we get rid of our own buffers */
 775 #ifdef FLUSH_TO_PPP
 776       ppp_output_wakeup(&ap->chan);
 777 #endif /* FLUSH_TO_PPP */
 778       err = 0;
 779       break;
 780
 781     case FIONREAD:
 782       DEBUG(FS_INFO, "FIONREAD\n");
 783       val = 0;
 784       if(put_user(val, (int __user *)argp))
 785         break;
 786       err = 0;
 787       break;
 788
 789     default:
 790       DERROR(FS_ERROR, "Unsupported ioctl (0x%X)\n", cmd);
 791       err = -ENOIOCTLCMD;
 792     }
 793
 794   DEXIT(FS_TRACE, " - err = 0x%X\n", err);
 795   return err;
 796 }
 797
 798 /************************** PPP CALLBACKS **************************/
 799 /*
 800  * This are the functions that the generic PPP driver in the kernel
 801  * will call to communicate to us.
 802  */
 803
 804 /*------------------------------------------------------------------*/
 805 /*
 806  * Prepare the ppp frame for transmission over the IrDA socket.
 807  * We make sure that the header space is enough, and we change ppp header
 808  * according to flags passed by pppd.
 809  * This is not a callback, but just a helper function used in ppp_irnet_send()
 810  */
 811 static inline struct sk_buff *
 812 irnet_prepare_skb(irnet_socket *        ap,
 813                   struct sk_buff *      skb)
 814 {
 815   unsigned char *       data;
 816   int                   proto;          /* PPP protocol */
 817   int                   islcp;          /* Protocol == LCP */
 818   int                   needaddr;       /* Need PPP address */
 819
 820   DENTER(PPP_TRACE, "(ap=0x%p, skb=0x%p)\n",
 821          ap, skb);
 822
 823   /* Extract PPP protocol from the frame */
 824   data  = skb->data;
 825   proto = (data[0] << 8) + data[1];
 826
 827   /* LCP packets with codes between 1 (configure-request)
 828    * and 7 (code-reject) must be sent as though no options
 829    * have been negotiated. */
 830   islcp = (proto == PPP_LCP) && (1 <= data[2]) && (data[2] <= 7);
 831
 832   /* compress protocol field if option enabled */
 833   if((data[0] == 0) && (ap->flags & SC_COMP_PROT) && (!islcp))
 834     skb_pull(skb,1);
 835
 836   /* Check if we need address/control fields */
 837   needaddr = 2*((ap->flags & SC_COMP_AC) == 0 || islcp);
 838
 839   /* Is the skb headroom large enough to contain all IrDA-headers? */
 840   if((skb_headroom(skb) < (ap->max_header_size + needaddr)) ||
 841       (skb_shared(skb)))
 842     {
 843       struct sk_buff *  new_skb;
 844
 845       DEBUG(PPP_INFO, "Reallocating skb\n");
 846
 847       /* Create a new skb */
 848       new_skb = skb_realloc_headroom(skb, ap->max_header_size + needaddr);
 849
 850       /* We have to free the original skb anyway */
 851       dev_kfree_skb(skb);
 852
 853       /* Did the realloc succeed ? */
 854       DABORT(new_skb == NULL, NULL, PPP_ERROR, "Could not realloc skb\n");
 855
 856       /* Use the new skb instead */
 857       skb = new_skb;
 858     }
 859
 860   /* prepend address/control fields if necessary */
 861   if(needaddr)
 862     {
 863       skb_push(skb, 2);
 864       skb->data[0] = PPP_ALLSTATIONS;
 865       skb->data[1] = PPP_UI;
 866     }
 867
 868   DEXIT(PPP_TRACE, "\n");
 869
 870   return skb;
 871 }
 872
 873 /*------------------------------------------------------------------*/
 874 /*
 875  * Send a packet to the peer over the IrTTP connection.
 876  * Returns 1 iff the packet was accepted.
 877  * Returns 0 iff packet was not consumed.
 878  * If the packet was not accepted, we will call ppp_output_wakeup
 879  * at some later time to reactivate flow control in ppp_generic.
 880  */
 881 static int
 882 ppp_irnet_send(struct ppp_channel *     chan,
 883                struct sk_buff *         skb)
 884 {
 885   irnet_socket *        self = (struct irnet_socket *) chan->private;
 886   int                   ret;
 887
 888   DENTER(PPP_TRACE, "(channel=0x%p, ap/self=0x%p)\n",
 889          chan, self);
 890
 891   /* Check if things are somewhat valid... */
 892   DASSERT(self != NULL, 0, PPP_ERROR, "Self is NULL !!!\n");
 893
 894   /* Check if we are connected */
 895   if(!(test_bit(0, &self->ttp_open)))
 896     {
 897 #ifdef CONNECT_IN_SEND
 898       /* Let's try to connect one more time... */
 899       /* Note : we won't be connected after this call, but we should be
 900        * ready for next packet... */
 901       /* If we are already connecting, this will fail */
 902       irda_irnet_connect(self);
 903 #endif /* CONNECT_IN_SEND */
 904
 905       DEBUG(PPP_INFO, "IrTTP not ready ! (%ld-%ld)\n",
 906             self->ttp_open, self->ttp_connect);
 907
 908       /* Note : we can either drop the packet or block the packet.
 909        *
 910        * Blocking the packet allow us a better connection time,
 911        * because by calling ppp_output_wakeup() we can have
 912        * ppp_generic resending the LCP request immediately to us,
 913        * rather than waiting for one of pppd periodic transmission of
 914        * LCP request.
 915        *
 916        * On the other hand, if we block all packet, all those periodic
 917        * transmissions of pppd accumulate in ppp_generic, creating a
 918        * backlog of LCP request. When we eventually connect later on,
 919        * we have to transmit all this backlog before we can connect
 920        * proper (if we don't timeout before).
 921        *
 922        * The current strategy is as follow :
 923        * While we are attempting to connect, we block packets to get
 924        * a better connection time.
 925        * If we fail to connect, we drain the queue and start dropping packets
 926        */
 927 #ifdef BLOCK_WHEN_CONNECT
 928       /* If we are attempting to connect */
 929       if(test_bit(0, &self->ttp_connect))
 930         {
 931           /* Blocking packet, ppp_generic will retry later */
 932           return 0;
 933         }
 934 #endif /* BLOCK_WHEN_CONNECT */
 935
 936       /* Dropping packet, pppd will retry later */
 937       dev_kfree_skb(skb);
 938       return 1;
 939     }
 940
 941   /* Check if the queue can accept any packet, otherwise block */
 942   if(self->tx_flow != FLOW_START)
 943     DRETURN(0, PPP_INFO, "IrTTP queue full (%d skbs)...\n",
 944             skb_queue_len(&self->tsap->tx_queue));
 945
 946   /* Prepare ppp frame for transmission */
 947   skb = irnet_prepare_skb(self, skb);
 948   DABORT(skb == NULL, 1, PPP_ERROR, "Prepare skb for Tx failed.\n");
 949
 950   /* Send the packet to IrTTP */
 951   ret = irttp_data_request(self->tsap, skb);
 952   if(ret < 0)
 953     {
 954       /*
 955        * > IrTTPs tx queue is full, so we just have to
 956        * > drop the frame! You might think that we should
 957        * > just return -1 and don't deallocate the frame,
 958        * > but that is dangerous since it's possible that
 959        * > we have replaced the original skb with a new
 960        * > one with larger headroom, and that would really
 961        * > confuse do_dev_queue_xmit() in dev.c! I have
 962        * > tried :-) DB
 963        * Correction : we verify the flow control above (self->tx_flow),
 964        * so we come here only if IrTTP doesn't like the packet (empty,
 965        * too large, IrTTP not connected). In those rare cases, it's ok
 966        * to drop it, we don't want to see it here again...
 967        * Jean II
 968        */
 969       DERROR(PPP_ERROR, "IrTTP doesn't like this packet !!! (0x%X)\n", ret);
 970       /* irttp_data_request already free the packet */
 971     }
 972
 973   DEXIT(PPP_TRACE, "\n");
 974   return 1;     /* Packet has been consumed */
 975 }
 976
 977 /*------------------------------------------------------------------*/
 978 /*
 979  * Take care of the ioctls that ppp_generic doesn't want to deal with...
 980  * Note : we are also called from dev_irnet_ioctl().
 981  */
 982 static int
 983 ppp_irnet_ioctl(struct ppp_channel *    chan,
 984                 unsigned int            cmd,
 985                 unsigned long           arg)
 986 {
 987   irnet_socket *        ap = (struct irnet_socket *) chan->private;
 988   int                   err;
 989   int                   val;
 990   u32                   accm[8];
 991   void __user *argp = (void __user *)arg;
 992
 993   DENTER(PPP_TRACE, "(channel=0x%p, ap=0x%p, cmd=0x%X)\n",
 994          chan, ap, cmd);
 995
 996   /* Basic checks... */
 997   DASSERT(ap != NULL, -ENXIO, PPP_ERROR, "ap is NULL...\n");
 998
 999   err = -EFAULT;
1000   switch(cmd)
1001     {
1002       /* PPP flags */
1003     case PPPIOCGFLAGS:
1004       val = ap->flags | ap->rbits;
1005       if(put_user(val, (int __user *) argp))
1006         break;
1007       err = 0;
1008       break;
1009     case PPPIOCSFLAGS:
1010       if(get_user(val, (int __user *) argp))
1011         break;
1012       ap->flags = val & ~SC_RCV_BITS;
1013       ap->rbits = val & SC_RCV_BITS;
1014       err = 0;
1015       break;
1016
1017       /* Async map stuff - all dummy to please pppd */
1018     case PPPIOCGASYNCMAP:
1019       if(put_user(ap->xaccm[0], (u32 __user *) argp))
1020         break;
1021       err = 0;
1022       break;
1023     case PPPIOCSASYNCMAP:
1024       if(get_user(ap->xaccm[0], (u32 __user *) argp))
1025         break;
1026       err = 0;
1027       break;
1028     case PPPIOCGRASYNCMAP:
1029       if(put_user(ap->raccm, (u32 __user *) argp))
1030         break;
1031       err = 0;
1032       break;
1033     case PPPIOCSRASYNCMAP:
1034       if(get_user(ap->raccm, (u32 __user *) argp))
1035         break;
1036       err = 0;
1037       break;
1038     case PPPIOCGXASYNCMAP:
1039       if(copy_to_user(argp, ap->xaccm, sizeof(ap->xaccm)))
1040         break;
1041       err = 0;
1042       break;
1043     case PPPIOCSXASYNCMAP:
1044       if(copy_from_user(accm, argp, sizeof(accm)))
1045         break;
1046       accm[2] &= ~0x40000000U;          /* can't escape 0x5e */
1047       accm[3] |= 0x60000000U;           /* must escape 0x7d, 0x7e */
1048       memcpy(ap->xaccm, accm, sizeof(ap->xaccm));
1049       err = 0;
1050       break;
1051
1052       /* Max PPP frame size */
1053     case PPPIOCGMRU:
1054       if(put_user(ap->mru, (int __user *) argp))
1055         break;
1056       err = 0;
1057       break;
1058     case PPPIOCSMRU:
1059       if(get_user(val, (int __user *) argp))
1060         break;
1061       if(val < PPP_MRU)
1062         val = PPP_MRU;
1063       ap->mru = val;
1064       err = 0;
1065       break;
1066
1067     default:
1068       DEBUG(PPP_INFO, "Unsupported ioctl (0x%X)\n", cmd);
1069       err = -ENOIOCTLCMD;
1070     }
1071
1072   DEXIT(PPP_TRACE, " - err = 0x%X\n", err);
1073   return err;
1074 }
1075
1076 /************************** INITIALISATION **************************/
1077 /*
1078  * Module initialisation and all that jazz...
1079  */
1080
1081 /*------------------------------------------------------------------*/
1082 /*
1083  * Hook our device callbacks in the filesystem, to connect our code
1084  * to /dev/irnet
1085  */
1086 static inline int __init
1087 ppp_irnet_init(void)
1088 {
1089   int err = 0;
1090
1091   DENTER(MODULE_TRACE, "()\n");
1092
1093   /* Allocate ourselves as a minor in the misc range */
1094   err = misc_register(&irnet_misc_device);
1095
1096   DEXIT(MODULE_TRACE, "\n");
1097   return err;
1098 }
1099
1100 /*------------------------------------------------------------------*/
1101 /*
1102  * Cleanup at exit...
1103  */
1104 static inline void __exit
1105 ppp_irnet_cleanup(void)
1106 {
1107   DENTER(MODULE_TRACE, "()\n");
1108
1109   /* De-allocate /dev/irnet minor in misc range */
1110   misc_deregister(&irnet_misc_device);
1111
1112   DEXIT(MODULE_TRACE, "\n");
1113 }
1114
1115 /*------------------------------------------------------------------*/
1116 /*
1117  * Module main entry point
1118  */
1119 static int __init
1120 irnet_init(void)
1121 {
1122   int err;
1123
1124   /* Initialise both parts... */
1125   err = irda_irnet_init();
1126   if(!err)
1127     err = ppp_irnet_init();
1128   return err;
1129 }
1130
1131 /*------------------------------------------------------------------*/
1132 /*
1133  * Module exit
1134  */
1135 static void __exit
1136 irnet_cleanup(void)
1137 {
1138   irda_irnet_cleanup();
1139   ppp_irnet_cleanup();
1140 }
1141
1142 /*------------------------------------------------------------------*/
1143 /*
1144  * Module magic
1145  */
1146 module_init(irnet_init);
1147 module_exit(irnet_cleanup);
1148 MODULE_AUTHOR("Jean Tourrilhes <jt@hpl.hp.com>");
1149 MODULE_DESCRIPTION("IrNET : Synchronous PPP over IrDA");
1150 MODULE_LICENSE("GPL");
1151 MODULE_ALIAS_CHARDEV(10, 187);