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 <linux/sched.h>
  17 #include <linux/slab.h>
  18 #include <linux/smp_lock.h>
  19 #include "irnet_ppp.h"          /* Private header */
  20 /* Please put other headers in irnet.h - Thanks */
  21
  22 /* Generic PPP callbacks (to call us) */
  23 static const struct ppp_channel_ops irnet_ppp_ops = {
  24         .start_xmit = ppp_irnet_send,
  25         .ioctl = ppp_irnet_ioctl
  26 };
  27
  28 /************************* CONTROL CHANNEL *************************/
  29 /*
  30  * When a pppd instance is not active on /dev/irnet, it acts as a control
  31  * channel.
  32  * Writing allow to set up the IrDA destination of the IrNET channel,
  33  * and any application may be read events happening in IrNET...
  34  */
  35
  36 /*------------------------------------------------------------------*/
  37 /*
  38  * Write is used to send a command to configure a IrNET channel
  39  * before it is open by pppd. The syntax is : "command argument"
  40  * Currently there is only two defined commands :
  41  *      o name : set the requested IrDA nickname of the IrNET peer.
  42  *      o addr : set the requested IrDA address of the IrNET peer.
  43  * Note : the code is crude, but effective...
  44  */
  45 static inline ssize_t
  46 irnet_ctrl_write(irnet_socket * ap,
  47                  const char __user *buf,
  48                  size_t         count)
  49 {
  50   char          command[IRNET_MAX_COMMAND];
  51   char *        start;          /* Current command being processed */
  52   char *        next;           /* Next command to process */
  53   int           length;         /* Length of current command */
  54
  55   DENTER(CTRL_TRACE, "(ap=0x%p, count=%Zd)\n", ap, count);
  56
  57   /* Check for overflow... */
  58   DABORT(count >= IRNET_MAX_COMMAND, -ENOMEM,
  59          CTRL_ERROR, "Too much data !!!\n");
  60
  61   /* Get the data in the driver */
  62   if(copy_from_user(command, buf, count))
  63     {
  64       DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
  65       return -EFAULT;
  66     }
  67
  68   /* Safe terminate the string */
  69   command[count] = '\0';
  70   DEBUG(CTRL_INFO, "Command line received is ``%s'' (%Zd).\n",
  71         command, count);
  72
  73   /* Check every commands in the command line */
  74   next = command;
  75   while(next != NULL)
  76     {
  77       /* Look at the next command */
  78       start = next;
  79
  80         /* Scrap whitespaces before the command */
  81         start = skip_spaces(start);
  82
  83       /* ',' is our command separator */
  84       next = strchr(start, ',');
  85       if(next)
  86         {
  87           *next = '\0';                 /* Terminate command */
  88           length = next - start;        /* Length */
  89           next++;                       /* Skip the '\0' */
  90         }
  91       else
  92         length = strlen(start);
  93
  94       DEBUG(CTRL_INFO, "Found command ``%s'' (%d).\n", start, length);
  95
  96       /* Check if we recognised one of the known command
  97        * We can't use "switch" with strings, so hack with "continue" */
  98
  99       /* First command : name -> Requested IrDA nickname */
 100       if(!strncmp(start, "name", 4))
 101         {
 102           /* Copy the name only if is included and not "any" */
 103           if((length > 5) && (strcmp(start + 5, "any")))
 104             {
 105               /* Strip out trailing whitespaces */
 106               while(isspace(start[length - 1]))
 107                 length--;
 108
 109               /* Copy the name for later reuse */
 110               memcpy(ap->rname, start + 5, length - 5);
 111               ap->rname[length - 5] = '\0';
 112             }
 113           else
 114             ap->rname[0] = '\0';
 115           DEBUG(CTRL_INFO, "Got rname = ``%s''\n", ap->rname);
 116
 117           /* Restart the loop */
 118           continue;
 119         }
 120
 121       /* Second command : addr, daddr -> Requested IrDA destination address
 122        * Also process : saddr -> Requested IrDA source address */
 123       if((!strncmp(start, "addr", 4)) ||
 124          (!strncmp(start, "daddr", 5)) ||
 125          (!strncmp(start, "saddr", 5)))
 126         {
 127           __u32         addr = DEV_ADDR_ANY;
 128
 129           /* Copy the address only if is included and not "any" */
 130           if((length > 5) && (strcmp(start + 5, "any")))
 131             {
 132               char *    begp = start + 5;
 133               char *    endp;
 134
 135               /* Scrap whitespaces before the command */
 136               begp = skip_spaces(begp);
 137
 138               /* Convert argument to a number (last arg is the base) */
 139               addr = simple_strtoul(begp, &endp, 16);
 140               /* Has it worked  ? (endp should be start + length) */
 141               DABORT(endp <= (start + 5), -EINVAL,
 142                      CTRL_ERROR, "Invalid address.\n");
 143             }
 144           /* Which type of address ? */
 145           if(start[0] == 's')
 146             {
 147               /* Save it */
 148               ap->rsaddr = addr;
 149               DEBUG(CTRL_INFO, "Got rsaddr = %08x\n", ap->rsaddr);
 150             }
 151           else
 152             {
 153               /* Save it */
 154               ap->rdaddr = addr;
 155               DEBUG(CTRL_INFO, "Got rdaddr = %08x\n", ap->rdaddr);
 156             }
 157
 158           /* Restart the loop */
 159           continue;
 160         }
 161
 162       /* Other possible command : connect N (number of retries) */
 163
 164       /* No command matched -> Failed... */
 165       DABORT(1, -EINVAL, CTRL_ERROR, "Not a recognised IrNET command.\n");
 166     }
 167
 168   /* Success : we have parsed all commands successfully */
 169   return count;
 170 }
 171
 172 #ifdef INITIAL_DISCOVERY
 173 /*------------------------------------------------------------------*/
 174 /*
 175  * Function irnet_get_discovery_log (self)
 176  *
 177  *    Query the content on the discovery log if not done
 178  *
 179  * This function query the current content of the discovery log
 180  * at the startup of the event channel and save it in the internal struct.
 181  */
 182 static void
 183 irnet_get_discovery_log(irnet_socket *  ap)
 184 {
 185   __u16         mask = irlmp_service_to_hint(S_LAN);
 186
 187   /* Ask IrLMP for the current discovery log */
 188   ap->discoveries = irlmp_get_discoveries(&ap->disco_number, mask,
 189                                           DISCOVERY_DEFAULT_SLOTS);
 190
 191   /* Check if the we got some results */
 192   if(ap->discoveries == NULL)
 193     ap->disco_number = -1;
 194
 195   DEBUG(CTRL_INFO, "Got the log (0x%p), size is %d\n",
 196         ap->discoveries, ap->disco_number);
 197 }
 198
 199 /*------------------------------------------------------------------*/
 200 /*
 201  * Function irnet_read_discovery_log (self, event)
 202  *
 203  *    Read the content on the discovery log
 204  *
 205  * This function dump the current content of the discovery log
 206  * at the startup of the event channel.
 207  * Return 1 if wrote an event on the control channel...
 208  *
 209  * State of the ap->disco_XXX variables :
 210  * Socket creation :  discoveries = NULL ; disco_index = 0 ; disco_number = 0
 211  * While reading :    discoveries = ptr  ; disco_index = X ; disco_number = Y
 212  * After reading :    discoveries = NULL ; disco_index = Y ; disco_number = -1
 213  */
 214 static inline int
 215 irnet_read_discovery_log(irnet_socket * ap,
 216                          char *         event)
 217 {
 218   int           done_event = 0;
 219
 220   DENTER(CTRL_TRACE, "(ap=0x%p, event=0x%p)\n",
 221          ap, event);
 222
 223   /* Test if we have some work to do or we have already finished */
 224   if(ap->disco_number == -1)
 225     {
 226       DEBUG(CTRL_INFO, "Already done\n");
 227       return 0;
 228     }
 229
 230   /* Test if it's the first time and therefore we need to get the log */
 231   if(ap->discoveries == NULL)
 232     irnet_get_discovery_log(ap);
 233
 234   /* Check if we have more item to dump */
 235   if(ap->disco_index < ap->disco_number)
 236     {
 237       /* Write an event */
 238       sprintf(event, "Found %08x (%s) behind %08x {hints %02X-%02X}\n",
 239               ap->discoveries[ap->disco_index].daddr,
 240               ap->discoveries[ap->disco_index].info,
 241               ap->discoveries[ap->disco_index].saddr,
 242               ap->discoveries[ap->disco_index].hints[0],
 243               ap->discoveries[ap->disco_index].hints[1]);
 244       DEBUG(CTRL_INFO, "Writing discovery %d : %s\n",
 245             ap->disco_index, ap->discoveries[ap->disco_index].info);
 246
 247       /* We have an event */
 248       done_event = 1;
 249       /* Next discovery */
 250       ap->disco_index++;
 251     }
 252
 253   /* Check if we have done the last item */
 254   if(ap->disco_index >= ap->disco_number)
 255     {
 256       /* No more items : remove the log and signal termination */
 257       DEBUG(CTRL_INFO, "Cleaning up log (0x%p)\n",
 258             ap->discoveries);
 259       if(ap->discoveries != NULL)
 260         {
 261           /* Cleanup our copy of the discovery log */
 262           kfree(ap->discoveries);
 263           ap->discoveries = NULL;
 264         }
 265       ap->disco_number = -1;
 266     }
 267
 268   return done_event;
 269 }
 270 #endif /* INITIAL_DISCOVERY */
 271
 272 /*------------------------------------------------------------------*/
 273 /*
 274  * Read is used to get IrNET events
 275  */
 276 static inline ssize_t
 277 irnet_ctrl_read(irnet_socket *  ap,
 278                 struct file *   file,
 279                 char __user *   buf,
 280                 size_t          count)
 281 {
 282   DECLARE_WAITQUEUE(wait, current);
 283   char          event[64];      /* Max event is 61 char */
 284   ssize_t       ret = 0;
 285
 286   DENTER(CTRL_TRACE, "(ap=0x%p, count=%Zd)\n", ap, count);
 287
 288   /* Check if we can write an event out in one go */
 289   DABORT(count < sizeof(event), -EOVERFLOW, CTRL_ERROR, "Buffer to small.\n");
 290
 291 #ifdef INITIAL_DISCOVERY
 292   /* Check if we have read the log */
 293   if(irnet_read_discovery_log(ap, event))
 294     {
 295       /* We have an event !!! Copy it to the user */
 296       if(copy_to_user(buf, event, strlen(event)))
 297         {
 298           DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
 299           return -EFAULT;
 300         }
 301
 302       DEXIT(CTRL_TRACE, "\n");
 303       return strlen(event);
 304     }
 305 #endif /* INITIAL_DISCOVERY */
 306
 307   /* Put ourselves on the wait queue to be woken up */
 308   add_wait_queue(&irnet_events.rwait, &wait);
 309   current->state = TASK_INTERRUPTIBLE;
 310   for(;;)
 311     {
 312       /* If there is unread events */
 313       ret = 0;
 314       if(ap->event_index != irnet_events.index)
 315         break;
 316       ret = -EAGAIN;
 317       if(file->f_flags & O_NONBLOCK)
 318         break;
 319       ret = -ERESTARTSYS;
 320       if(signal_pending(current))
 321         break;
 322       /* Yield and wait to be woken up */
 323       schedule();
 324     }
 325   current->state = TASK_RUNNING;
 326   remove_wait_queue(&irnet_events.rwait, &wait);
 327
 328   /* Did we got it ? */
 329   if(ret != 0)
 330     {
 331       /* No, return the error code */
 332       DEXIT(CTRL_TRACE, " - ret %Zd\n", ret);
 333       return ret;
 334     }
 335
 336   /* Which event is it ? */
 337   switch(irnet_events.log[ap->event_index].event)
 338     {
 339     case IRNET_DISCOVER:
 340       sprintf(event, "Discovered %08x (%s) behind %08x {hints %02X-%02X}\n",
 341               irnet_events.log[ap->event_index].daddr,
 342               irnet_events.log[ap->event_index].name,
 343               irnet_events.log[ap->event_index].saddr,
 344               irnet_events.log[ap->event_index].hints.byte[0],
 345               irnet_events.log[ap->event_index].hints.byte[1]);
 346       break;
 347     case IRNET_EXPIRE:
 348       sprintf(event, "Expired %08x (%s) behind %08x {hints %02X-%02X}\n",
 349               irnet_events.log[ap->event_index].daddr,
 350               irnet_events.log[ap->event_index].name,
 351               irnet_events.log[ap->event_index].saddr,
 352               irnet_events.log[ap->event_index].hints.byte[0],
 353               irnet_events.log[ap->event_index].hints.byte[1]);
 354       break;
 355     case IRNET_CONNECT_TO:
 356       sprintf(event, "Connected to %08x (%s) on ppp%d\n",
 357               irnet_events.log[ap->event_index].daddr,
 358               irnet_events.log[ap->event_index].name,
 359               irnet_events.log[ap->event_index].unit);
 360       break;
 361     case IRNET_CONNECT_FROM:
 362       sprintf(event, "Connection from %08x (%s) on ppp%d\n",
 363               irnet_events.log[ap->event_index].daddr,
 364               irnet_events.log[ap->event_index].name,
 365               irnet_events.log[ap->event_index].unit);
 366       break;
 367     case IRNET_REQUEST_FROM:
 368       sprintf(event, "Request from %08x (%s) behind %08x\n",
 369               irnet_events.log[ap->event_index].daddr,
 370               irnet_events.log[ap->event_index].name,
 371               irnet_events.log[ap->event_index].saddr);
 372       break;
 373     case IRNET_NOANSWER_FROM:
 374       sprintf(event, "No-answer from %08x (%s) on ppp%d\n",
 375               irnet_events.log[ap->event_index].daddr,
 376               irnet_events.log[ap->event_index].name,
 377               irnet_events.log[ap->event_index].unit);
 378       break;
 379     case IRNET_BLOCKED_LINK:
 380       sprintf(event, "Blocked link with %08x (%s) on ppp%d\n",
 381               irnet_events.log[ap->event_index].daddr,
 382               irnet_events.log[ap->event_index].name,
 383               irnet_events.log[ap->event_index].unit);
 384       break;
 385     case IRNET_DISCONNECT_FROM:
 386       sprintf(event, "Disconnection from %08x (%s) on ppp%d\n",
 387               irnet_events.log[ap->event_index].daddr,
 388               irnet_events.log[ap->event_index].name,
 389               irnet_events.log[ap->event_index].unit);
 390       break;
 391     case IRNET_DISCONNECT_TO:
 392       sprintf(event, "Disconnected to %08x (%s)\n",
 393               irnet_events.log[ap->event_index].daddr,
 394               irnet_events.log[ap->event_index].name);
 395       break;
 396     default:
 397       sprintf(event, "Bug\n");
 398     }
 399   /* Increment our event index */
 400   ap->event_index = (ap->event_index + 1) % IRNET_MAX_EVENTS;
 401
 402   DEBUG(CTRL_INFO, "Event is :%s", event);
 403
 404   /* Copy it to the user */
 405   if(copy_to_user(buf, event, strlen(event)))
 406     {
 407       DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
 408       return -EFAULT;
 409     }
 410
 411   DEXIT(CTRL_TRACE, "\n");
 412   return strlen(event);
 413 }
 414
 415 /*------------------------------------------------------------------*/
 416 /*
 417  * Poll : called when someone do a select on /dev/irnet.
 418  * Just check if there are new events...
 419  */
 420 static inline unsigned int
 421 irnet_ctrl_poll(irnet_socket *  ap,
 422                 struct file *   file,
 423                 poll_table *    wait)
 424 {
 425   unsigned int mask;
 426
 427   DENTER(CTRL_TRACE, "(ap=0x%p)\n", ap);
 428
 429   poll_wait(file, &irnet_events.rwait, wait);
 430   mask = POLLOUT | POLLWRNORM;
 431   /* If there is unread events */
 432   if(ap->event_index != irnet_events.index)
 433     mask |= POLLIN | POLLRDNORM;
 434 #ifdef INITIAL_DISCOVERY
 435   if(ap->disco_number != -1)
 436     {
 437       /* Test if it's the first time and therefore we need to get the log */
 438       if(ap->discoveries == NULL)
 439         irnet_get_discovery_log(ap);
 440       /* Recheck */
 441       if(ap->disco_number != -1)
 442         mask |= POLLIN | POLLRDNORM;
 443     }
 444 #endif /* INITIAL_DISCOVERY */
 445
 446   DEXIT(CTRL_TRACE, " - mask=0x%X\n", mask);
 447   return mask;
 448 }
 449
 450
 451 /*********************** FILESYSTEM CALLBACKS ***********************/
 452 /*
 453  * Implement the usual open, read, write functions that will be called
 454  * by the file system when some action is performed on /dev/irnet.
 455  * Most of those actions will in fact be performed by "pppd" or
 456  * the control channel, we just act as a redirector...
 457  */
 458
 459 /*------------------------------------------------------------------*/
 460 /*
 461  * Open : when somebody open /dev/irnet
 462  * We basically create a new instance of irnet and initialise it.
 463  */
 464 static int
 465 dev_irnet_open(struct inode *   inode,
 466                struct file *    file)
 467 {
 468   struct irnet_socket * ap;
 469   int                   err;
 470
 471   DENTER(FS_TRACE, "(file=0x%p)\n", file);
 472
 473 #ifdef SECURE_DEVIRNET
 474   /* This could (should?) be enforced by the permissions on /dev/irnet. */
 475   if(!capable(CAP_NET_ADMIN))
 476     return -EPERM;
 477 #endif /* SECURE_DEVIRNET */
 478
 479   /* Allocate a private structure for this IrNET instance */
 480   ap = kzalloc(sizeof(*ap), GFP_KERNEL);
 481   DABORT(ap == NULL, -ENOMEM, FS_ERROR, "Can't allocate struct irnet...\n");
 482
 483   /* initialize the irnet structure */
 484   ap->file = file;
 485
 486   /* PPP channel setup */
 487   ap->ppp_open = 0;
 488   ap->chan.private = ap;
 489   ap->chan.ops = &irnet_ppp_ops;
 490   ap->chan.mtu = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
 491   ap->chan.hdrlen = 2 + TTP_MAX_HEADER;         /* for A/C + Max IrDA hdr */
 492   /* PPP parameters */
 493   ap->mru = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
 494   ap->xaccm[0] = ~0U;
 495   ap->xaccm[3] = 0x60000000U;
 496   ap->raccm = ~0U;
 497
 498   /* Setup the IrDA part... */
 499   err = irda_irnet_create(ap);
 500   if(err)
 501     {
 502       DERROR(FS_ERROR, "Can't setup IrDA link...\n");
 503       kfree(ap);
 504
 505       return err;
 506     }
 507
 508   /* For the control channel */
 509   ap->event_index = irnet_events.index; /* Cancel all past events */
 510
 511   mutex_init(&ap->lock);
 512
 513   /* Put our stuff where we will be able to find it later */
 514   file->private_data = ap;
 515
 516   DEXIT(FS_TRACE, " - ap=0x%p\n", ap);
 517
 518   return 0;
 519 }
 520
 521
 522 /*------------------------------------------------------------------*/
 523 /*
 524  * Close : when somebody close /dev/irnet
 525  * Destroy the instance of /dev/irnet
 526  */
 527 static int
 528 dev_irnet_close(struct inode *  inode,
 529                 struct file *   file)
 530 {
 531   irnet_socket *        ap = file->private_data;
 532
 533   DENTER(FS_TRACE, "(file=0x%p, ap=0x%p)\n",
 534          file, ap);
 535   DABORT(ap == NULL, 0, FS_ERROR, "ap is NULL !!!\n");
 536
 537   /* Detach ourselves */
 538   file->private_data = NULL;
 539
 540   /* Close IrDA stuff */
 541   irda_irnet_destroy(ap);
 542
 543   /* Disconnect from the generic PPP layer if not already done */
 544   if(ap->ppp_open)
 545     {
 546       DERROR(FS_ERROR, "Channel still registered - deregistering !\n");
 547       ap->ppp_open = 0;
 548       ppp_unregister_channel(&ap->chan);
 549     }
 550
 551   kfree(ap);
 552
 553   DEXIT(FS_TRACE, "\n");
 554   return 0;
 555 }
 556
 557 /*------------------------------------------------------------------*/
 558 /*
 559  * Write does nothing.
 560  * (we receive packet from ppp_generic through ppp_irnet_send())
 561  */
 562 static ssize_t
 563 dev_irnet_write(struct file *   file,
 564                 const char __user *buf,
 565                 size_t          count,
 566                 loff_t *        ppos)
 567 {
 568   irnet_socket *        ap = file->private_data;
 569
 570   DPASS(FS_TRACE, "(file=0x%p, ap=0x%p, count=%Zd)\n",
 571         file, ap, count);
 572   DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");
 573
 574   /* If we are connected to ppp_generic, let it handle the job */
 575   if(ap->ppp_open)
 576     return -EAGAIN;
 577   else
 578     return irnet_ctrl_write(ap, buf, count);
 579 }
 580
 581 /*------------------------------------------------------------------*/
 582 /*
 583  * Read doesn't do much either.
 584  * (pppd poll us, but ultimately reads through /dev/ppp)
 585  */
 586 static ssize_t
 587 dev_irnet_read(struct file *    file,
 588                char __user *    buf,
 589                size_t           count,
 590                loff_t *         ppos)
 591 {
 592   irnet_socket *        ap = file->private_data;
 593
 594   DPASS(FS_TRACE, "(file=0x%p, ap=0x%p, count=%Zd)\n",
 595         file, ap, count);
 596   DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");
 597
 598   /* If we are connected to ppp_generic, let it handle the job */
 599   if(ap->ppp_open)
 600     return -EAGAIN;
 601   else
 602     return irnet_ctrl_read(ap, file, buf, count);
 603 }
 604
 605 /*------------------------------------------------------------------*/
 606 /*
 607  * Poll : called when someone do a select on /dev/irnet
 608  */
 609 static unsigned int
 610 dev_irnet_poll(struct file *    file,
 611                poll_table *     wait)
 612 {
 613   irnet_socket *        ap = file->private_data;
 614   unsigned int          mask;
 615
 616   DENTER(FS_TRACE, "(file=0x%p, ap=0x%p)\n",
 617          file, ap);
 618
 619   mask = POLLOUT | POLLWRNORM;
 620   DABORT(ap == NULL, mask, FS_ERROR, "ap is NULL !!!\n");
 621
 622   /* If we are connected to ppp_generic, let it handle the job */
 623   if(!ap->ppp_open)
 624     mask |= irnet_ctrl_poll(ap, file, wait);
 625
 626   DEXIT(FS_TRACE, " - mask=0x%X\n", mask);
 627   return mask;
 628 }
 629
 630 /*------------------------------------------------------------------*/
 631 /*
 632  * IOCtl : Called when someone does some ioctls on /dev/irnet
 633  * This is the way pppd configure us and control us while the PPP
 634  * instance is active.
 635  */
 636 static long
 637 dev_irnet_ioctl(
 638                 struct file *   file,
 639                 unsigned int    cmd,
 640                 unsigned long   arg)
 641 {
 642   irnet_socket *        ap = file->private_data;
 643   int                   err;
 644   int                   val;
 645   void __user *argp = (void __user *)arg;
 646
 647   DENTER(FS_TRACE, "(file=0x%p, ap=0x%p, cmd=0x%X)\n",
 648          file, ap, cmd);
 649
 650   /* Basic checks... */
 651   DASSERT(ap != NULL, -ENXIO, PPP_ERROR, "ap is NULL...\n");
 652 #ifdef SECURE_DEVIRNET
 653   if(!capable(CAP_NET_ADMIN))
 654     return -EPERM;
 655 #endif /* SECURE_DEVIRNET */
 656
 657   err = -EFAULT;
 658   switch(cmd)
 659     {
 660       /* Set discipline (should be N_SYNC_PPP or N_TTY) */
 661     case TIOCSETD:
 662       if(get_user(val, (int __user *)argp))
 663         break;
 664       if((val == N_SYNC_PPP) || (val == N_PPP))
 665         {
 666           DEBUG(FS_INFO, "Entering PPP discipline.\n");
 667           /* PPP channel setup (ap->chan in configured in dev_irnet_open())*/
 668           if (mutex_lock_interruptible(&ap->lock))
 669                   return -EINTR;
 670
 671           err = ppp_register_channel(&ap->chan);
 672           if(err == 0)
 673             {
 674               /* Our ppp side is active */
 675               ap->ppp_open = 1;
 676
 677               DEBUG(FS_INFO, "Trying to establish a connection.\n");
 678               /* Setup the IrDA link now - may fail... */
 679               irda_irnet_connect(ap);
 680             }
 681           else
 682             DERROR(FS_ERROR, "Can't setup PPP channel...\n");
 683
 684           mutex_unlock(&ap->lock);
 685         }
 686       else
 687         {
 688           /* In theory, should be N_TTY */
 689           DEBUG(FS_INFO, "Exiting PPP discipline.\n");
 690           /* Disconnect from the generic PPP layer */
 691           if (mutex_lock_interruptible(&ap->lock))
 692                   return -EINTR;
 693
 694           if(ap->ppp_open)
 695             {
 696               ap->ppp_open = 0;
 697               ppp_unregister_channel(&ap->chan);
 698             }
 699           else
 700             DERROR(FS_ERROR, "Channel not registered !\n");
 701           err = 0;
 702
 703           mutex_unlock(&ap->lock);
 704         }
 705       break;
 706
 707       /* Query PPP channel and unit number */
 708     case PPPIOCGCHAN:
 709       if (mutex_lock_interruptible(&ap->lock))
 710               return -EINTR;
 711
 712       if(ap->ppp_open && !put_user(ppp_channel_index(&ap->chan),
 713                                                 (int __user *)argp))
 714         err = 0;
 715
 716       mutex_unlock(&ap->lock);
 717       break;
 718     case PPPIOCGUNIT:
 719       if (mutex_lock_interruptible(&ap->lock))
 720               return -EINTR;
 721
 722       if(ap->ppp_open && !put_user(ppp_unit_number(&ap->chan),
 723                                                 (int __user *)argp))
 724         err = 0;
 725
 726       mutex_unlock(&ap->lock);
 727       break;
 728
 729       /* All these ioctls can be passed both directly and from ppp_generic,
 730        * so we just deal with them in one place...
 731        */
 732     case PPPIOCGFLAGS:
 733     case PPPIOCSFLAGS:
 734     case PPPIOCGASYNCMAP:
 735     case PPPIOCSASYNCMAP:
 736     case PPPIOCGRASYNCMAP:
 737     case PPPIOCSRASYNCMAP:
 738     case PPPIOCGXASYNCMAP:
 739     case PPPIOCSXASYNCMAP:
 740     case PPPIOCGMRU:
 741     case PPPIOCSMRU:
 742       DEBUG(FS_INFO, "Standard PPP ioctl.\n");
 743       if(!capable(CAP_NET_ADMIN))
 744         err = -EPERM;
 745       else {
 746         if (mutex_lock_interruptible(&ap->lock))
 747               return -EINTR;
 748
 749         err = ppp_irnet_ioctl(&ap->chan, cmd, arg);
 750
 751         mutex_unlock(&ap->lock);
 752       }
 753       break;
 754
 755       /* TTY IOCTLs : Pretend that we are a tty, to keep pppd happy */
 756       /* Get termios */
 757     case TCGETS:
 758       DEBUG(FS_INFO, "Get termios.\n");
 759       if (mutex_lock_interruptible(&ap->lock))
 760               return -EINTR;
 761
 762 #ifndef TCGETS2
 763       if(!kernel_termios_to_user_termios((struct termios __user *)argp, &ap->termios))
 764         err = 0;
 765 #else
 766       if(kernel_termios_to_user_termios_1((struct termios __user *)argp, &ap->termios))
 767         err = 0;
 768 #endif
 769
 770       mutex_unlock(&ap->lock);
 771       break;
 772       /* Set termios */
 773     case TCSETSF:
 774       DEBUG(FS_INFO, "Set termios.\n");
 775       if (mutex_lock_interruptible(&ap->lock))
 776               return -EINTR;
 777
 778 #ifndef TCGETS2
 779       if(!user_termios_to_kernel_termios(&ap->termios, (struct termios __user *)argp))
 780         err = 0;
 781 #else
 782       if(!user_termios_to_kernel_termios_1(&ap->termios, (struct termios __user *)argp))
 783         err = 0;
 784 #endif
 785
 786       mutex_unlock(&ap->lock);
 787       break;
 788
 789       /* Set DTR/RTS */
 790     case TIOCMBIS:
 791     case TIOCMBIC:
 792       /* Set exclusive/non-exclusive mode */
 793     case TIOCEXCL:
 794     case TIOCNXCL:
 795       DEBUG(FS_INFO, "TTY compatibility.\n");
 796       err = 0;
 797       break;
 798
 799     case TCGETA:
 800       DEBUG(FS_INFO, "TCGETA\n");
 801       break;
 802
 803     case TCFLSH:
 804       DEBUG(FS_INFO, "TCFLSH\n");
 805       /* Note : this will flush buffers in PPP, so it *must* be done
 806        * We should also worry that we don't accept junk here and that
 807        * we get rid of our own buffers */
 808 #ifdef FLUSH_TO_PPP
 809       if (mutex_lock_interruptible(&ap->lock))
 810               return -EINTR;
 811       ppp_output_wakeup(&ap->chan);
 812       mutex_unlock(&ap->lock);
 813 #endif /* FLUSH_TO_PPP */
 814       err = 0;
 815       break;
 816
 817     case FIONREAD:
 818       DEBUG(FS_INFO, "FIONREAD\n");
 819       val = 0;
 820       if(put_user(val, (int __user *)argp))
 821         break;
 822       err = 0;
 823       break;
 824
 825     default:
 826       DERROR(FS_ERROR, "Unsupported ioctl (0x%X)\n", cmd);
 827       err = -ENOTTY;
 828     }
 829
 830   DEXIT(FS_TRACE, " - err = 0x%X\n", err);
 831   return err;
 832 }
 833
 834 /************************** PPP CALLBACKS **************************/
 835 /*
 836  * This are the functions that the generic PPP driver in the kernel
 837  * will call to communicate to us.
 838  */
 839
 840 /*------------------------------------------------------------------*/
 841 /*
 842  * Prepare the ppp frame for transmission over the IrDA socket.
 843  * We make sure that the header space is enough, and we change ppp header
 844  * according to flags passed by pppd.
 845  * This is not a callback, but just a helper function used in ppp_irnet_send()
 846  */
 847 static inline struct sk_buff *
 848 irnet_prepare_skb(irnet_socket *        ap,
 849                   struct sk_buff *      skb)
 850 {
 851   unsigned char *       data;
 852   int                   proto;          /* PPP protocol */
 853   int                   islcp;          /* Protocol == LCP */
 854   int                   needaddr;       /* Need PPP address */
 855
 856   DENTER(PPP_TRACE, "(ap=0x%p, skb=0x%p)\n",
 857          ap, skb);
 858
 859   /* Extract PPP protocol from the frame */
 860   data  = skb->data;
 861   proto = (data[0] << 8) + data[1];
 862
 863   /* LCP packets with codes between 1 (configure-request)
 864    * and 7 (code-reject) must be sent as though no options
 865    * have been negotiated. */
 866   islcp = (proto == PPP_LCP) && (1 <= data[2]) && (data[2] <= 7);
 867
 868   /* compress protocol field if option enabled */
 869   if((data[0] == 0) && (ap->flags & SC_COMP_PROT) && (!islcp))
 870     skb_pull(skb,1);
 871
 872   /* Check if we need address/control fields */
 873   needaddr = 2*((ap->flags & SC_COMP_AC) == 0 || islcp);
 874
 875   /* Is the skb headroom large enough to contain all IrDA-headers? */
 876   if((skb_headroom(skb) < (ap->max_header_size + needaddr)) ||
 877       (skb_shared(skb)))
 878     {
 879       struct sk_buff *  new_skb;
 880
 881       DEBUG(PPP_INFO, "Reallocating skb\n");
 882
 883       /* Create a new skb */
 884       new_skb = skb_realloc_headroom(skb, ap->max_header_size + needaddr);
 885
 886       /* We have to free the original skb anyway */
 887       dev_kfree_skb(skb);
 888
 889       /* Did the realloc succeed ? */
 890       DABORT(new_skb == NULL, NULL, PPP_ERROR, "Could not realloc skb\n");
 891
 892       /* Use the new skb instead */
 893       skb = new_skb;
 894     }
 895
 896   /* prepend address/control fields if necessary */
 897   if(needaddr)
 898     {
 899       skb_push(skb, 2);
 900       skb->data[0] = PPP_ALLSTATIONS;
 901       skb->data[1] = PPP_UI;
 902     }
 903
 904   DEXIT(PPP_TRACE, "\n");
 905
 906   return skb;
 907 }
 908
 909 /*------------------------------------------------------------------*/
 910 /*
 911  * Send a packet to the peer over the IrTTP connection.
 912  * Returns 1 iff the packet was accepted.
 913  * Returns 0 iff packet was not consumed.
 914  * If the packet was not accepted, we will call ppp_output_wakeup
 915  * at some later time to reactivate flow control in ppp_generic.
 916  */
 917 static int
 918 ppp_irnet_send(struct ppp_channel *     chan,
 919                struct sk_buff *         skb)
 920 {
 921   irnet_socket *        self = (struct irnet_socket *) chan->private;
 922   int                   ret;
 923
 924   DENTER(PPP_TRACE, "(channel=0x%p, ap/self=0x%p)\n",
 925          chan, self);
 926
 927   /* Check if things are somewhat valid... */
 928   DASSERT(self != NULL, 0, PPP_ERROR, "Self is NULL !!!\n");
 929
 930   /* Check if we are connected */
 931   if(!(test_bit(0, &self->ttp_open)))
 932     {
 933 #ifdef CONNECT_IN_SEND
 934       /* Let's try to connect one more time... */
 935       /* Note : we won't be connected after this call, but we should be
 936        * ready for next packet... */
 937       /* If we are already connecting, this will fail */
 938       irda_irnet_connect(self);
 939 #endif /* CONNECT_IN_SEND */
 940
 941       DEBUG(PPP_INFO, "IrTTP not ready ! (%ld-%ld)\n",
 942             self->ttp_open, self->ttp_connect);
 943
 944       /* Note : we can either drop the packet or block the packet.
 945        *
 946        * Blocking the packet allow us a better connection time,
 947        * because by calling ppp_output_wakeup() we can have
 948        * ppp_generic resending the LCP request immediately to us,
 949        * rather than waiting for one of pppd periodic transmission of
 950        * LCP request.
 951        *
 952        * On the other hand, if we block all packet, all those periodic
 953        * transmissions of pppd accumulate in ppp_generic, creating a
 954        * backlog of LCP request. When we eventually connect later on,
 955        * we have to transmit all this backlog before we can connect
 956        * proper (if we don't timeout before).
 957        *
 958        * The current strategy is as follow :
 959        * While we are attempting to connect, we block packets to get
 960        * a better connection time.
 961        * If we fail to connect, we drain the queue and start dropping packets
 962        */
 963 #ifdef BLOCK_WHEN_CONNECT
 964       /* If we are attempting to connect */
 965       if(test_bit(0, &self->ttp_connect))
 966         {
 967           /* Blocking packet, ppp_generic will retry later */
 968           return 0;
 969         }
 970 #endif /* BLOCK_WHEN_CONNECT */
 971
 972       /* Dropping packet, pppd will retry later */
 973       dev_kfree_skb(skb);
 974       return 1;
 975     }
 976
 977   /* Check if the queue can accept any packet, otherwise block */
 978   if(self->tx_flow != FLOW_START)
 979     DRETURN(0, PPP_INFO, "IrTTP queue full (%d skbs)...\n",
 980             skb_queue_len(&self->tsap->tx_queue));
 981
 982   /* Prepare ppp frame for transmission */
 983   skb = irnet_prepare_skb(self, skb);
 984   DABORT(skb == NULL, 1, PPP_ERROR, "Prepare skb for Tx failed.\n");
 985
 986   /* Send the packet to IrTTP */
 987   ret = irttp_data_request(self->tsap, skb);
 988   if(ret < 0)
 989     {
 990       /*
 991        * > IrTTPs tx queue is full, so we just have to
 992        * > drop the frame! You might think that we should
 993        * > just return -1 and don't deallocate the frame,
 994        * > but that is dangerous since it's possible that
 995        * > we have replaced the original skb with a new
 996        * > one with larger headroom, and that would really
 997        * > confuse do_dev_queue_xmit() in dev.c! I have
 998        * > tried :-) DB
 999        * Correction : we verify the flow control above (self->tx_flow),
1000        * so we come here only if IrTTP doesn't like the packet (empty,
1001        * too large, IrTTP not connected). In those rare cases, it's ok
1002        * to drop it, we don't want to see it here again...
1003        * Jean II
1004        */
1005       DERROR(PPP_ERROR, "IrTTP doesn't like this packet !!! (0x%X)\n", ret);
1006       /* irttp_data_request already free the packet */
1007     }
1008
1009   DEXIT(PPP_TRACE, "\n");
1010   return 1;     /* Packet has been consumed */
1011 }
1012
1013 /*------------------------------------------------------------------*/
1014 /*
1015  * Take care of the ioctls that ppp_generic doesn't want to deal with...
1016  * Note : we are also called from dev_irnet_ioctl().
1017  */
1018 static int
1019 ppp_irnet_ioctl(struct ppp_channel *    chan,
1020                 unsigned int            cmd,
1021                 unsigned long           arg)
1022 {
1023   irnet_socket *        ap = (struct irnet_socket *) chan->private;
1024   int                   err;
1025   int                   val;
1026   u32                   accm[8];
1027   void __user *argp = (void __user *)arg;
1028
1029   DENTER(PPP_TRACE, "(channel=0x%p, ap=0x%p, cmd=0x%X)\n",
1030          chan, ap, cmd);
1031
1032   /* Basic checks... */
1033   DASSERT(ap != NULL, -ENXIO, PPP_ERROR, "ap is NULL...\n");
1034
1035   err = -EFAULT;
1036   switch(cmd)
1037     {
1038       /* PPP flags */
1039     case PPPIOCGFLAGS:
1040       val = ap->flags | ap->rbits;
1041       if(put_user(val, (int __user *) argp))
1042         break;
1043       err = 0;
1044       break;
1045     case PPPIOCSFLAGS:
1046       if(get_user(val, (int __user *) argp))
1047         break;
1048       ap->flags = val & ~SC_RCV_BITS;
1049       ap->rbits = val & SC_RCV_BITS;
1050       err = 0;
1051       break;
1052
1053       /* Async map stuff - all dummy to please pppd */
1054     case PPPIOCGASYNCMAP:
1055       if(put_user(ap->xaccm[0], (u32 __user *) argp))
1056         break;
1057       err = 0;
1058       break;
1059     case PPPIOCSASYNCMAP:
1060       if(get_user(ap->xaccm[0], (u32 __user *) argp))
1061         break;
1062       err = 0;
1063       break;
1064     case PPPIOCGRASYNCMAP:
1065       if(put_user(ap->raccm, (u32 __user *) argp))
1066         break;
1067       err = 0;
1068       break;
1069     case PPPIOCSRASYNCMAP:
1070       if(get_user(ap->raccm, (u32 __user *) argp))
1071         break;
1072       err = 0;
1073       break;
1074     case PPPIOCGXASYNCMAP:
1075       if(copy_to_user(argp, ap->xaccm, sizeof(ap->xaccm)))
1076         break;
1077       err = 0;
1078       break;
1079     case PPPIOCSXASYNCMAP:
1080       if(copy_from_user(accm, argp, sizeof(accm)))
1081         break;
1082       accm[2] &= ~0x40000000U;          /* can't escape 0x5e */
1083       accm[3] |= 0x60000000U;           /* must escape 0x7d, 0x7e */
1084       memcpy(ap->xaccm, accm, sizeof(ap->xaccm));
1085       err = 0;
1086       break;
1087
1088       /* Max PPP frame size */
1089     case PPPIOCGMRU:
1090       if(put_user(ap->mru, (int __user *) argp))
1091         break;
1092       err = 0;
1093       break;
1094     case PPPIOCSMRU:
1095       if(get_user(val, (int __user *) argp))
1096         break;
1097       if(val < PPP_MRU)
1098         val = PPP_MRU;
1099       ap->mru = val;
1100       err = 0;
1101       break;
1102
1103     default:
1104       DEBUG(PPP_INFO, "Unsupported ioctl (0x%X)\n", cmd);
1105       err = -ENOIOCTLCMD;
1106     }
1107
1108   DEXIT(PPP_TRACE, " - err = 0x%X\n", err);
1109   return err;
1110 }
1111
1112 /************************** INITIALISATION **************************/
1113 /*
1114  * Module initialisation and all that jazz...
1115  */
1116
1117 /*------------------------------------------------------------------*/
1118 /*
1119  * Hook our device callbacks in the filesystem, to connect our code
1120  * to /dev/irnet
1121  */
1122 static inline int __init
1123 ppp_irnet_init(void)
1124 {
1125   int err = 0;
1126
1127   DENTER(MODULE_TRACE, "()\n");
1128
1129   /* Allocate ourselves as a minor in the misc range */
1130   err = misc_register(&irnet_misc_device);
1131
1132   DEXIT(MODULE_TRACE, "\n");
1133   return err;
1134 }
1135
1136 /*------------------------------------------------------------------*/
1137 /*
1138  * Cleanup at exit...
1139  */
1140 static inline void __exit
1141 ppp_irnet_cleanup(void)
1142 {
1143   DENTER(MODULE_TRACE, "()\n");
1144
1145   /* De-allocate /dev/irnet minor in misc range */
1146   misc_deregister(&irnet_misc_device);
1147
1148   DEXIT(MODULE_TRACE, "\n");
1149 }
1150
1151 /*------------------------------------------------------------------*/
1152 /*
1153  * Module main entry point
1154  */
1155 static int __init
1156 irnet_init(void)
1157 {
1158   int err;
1159
1160   /* Initialise both parts... */
1161   err = irda_irnet_init();
1162   if(!err)
1163     err = ppp_irnet_init();
1164   return err;
1165 }
1166
1167 /*------------------------------------------------------------------*/
1168 /*
1169  * Module exit
1170  */
1171 static void __exit
1172 irnet_cleanup(void)
1173 {
1174   irda_irnet_cleanup();
1175   ppp_irnet_cleanup();
1176 }
1177
1178 /*------------------------------------------------------------------*/
1179 /*
1180  * Module magic
1181  */
1182 module_init(irnet_init);
1183 module_exit(irnet_cleanup);
1184 MODULE_AUTHOR("Jean Tourrilhes <jt@hpl.hp.com>");
1185 MODULE_DESCRIPTION("IrNET : Synchronous PPP over IrDA");
1186 MODULE_LICENSE("GPL");
1187 MODULE_ALIAS_CHARDEV(10, 187);