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 "irnet_ppp.h"          /* Private header */
  19 /* Please put other headers in irnet.h - Thanks */
  20
  21 /* Generic PPP callbacks (to call us) */
  22 static const struct ppp_channel_ops irnet_ppp_ops = {
  23         .start_xmit = ppp_irnet_send,
  24         .ioctl = ppp_irnet_ioctl
  25 };
  26
  27 /************************* CONTROL CHANNEL *************************/
  28 /*
  29  * When a pppd instance is not active on /dev/irnet, it acts as a control
  30  * channel.
  31  * Writing allow to set up the IrDA destination of the IrNET channel,
  32  * and any application may be read events happening in IrNET...
  33  */
  34
  35 /*------------------------------------------------------------------*/
  36 /*
  37  * Write is used to send a command to configure a IrNET channel
  38  * before it is open by pppd. The syntax is : "command argument"
  39  * Currently there is only two defined commands :
  40  *      o name : set the requested IrDA nickname of the IrNET peer.
  41  *      o addr : set the requested IrDA address of the IrNET peer.
  42  * Note : the code is crude, but effective...
  43  */
  44 static inline ssize_t
  45 irnet_ctrl_write(irnet_socket * ap,
  46                  const char __user *buf,
  47                  size_t         count)
  48 {
  49   char          command[IRNET_MAX_COMMAND];
  50   char *        start;          /* Current command being processed */
  51   char *        next;           /* Next command to process */
  52   int           length;         /* Length of current command */
  53
  54   DENTER(CTRL_TRACE, "(ap=0x%p, count=%Zd)\n", ap, count);
  55
  56   /* Check for overflow... */
  57   DABORT(count >= IRNET_MAX_COMMAND, -ENOMEM,
  58          CTRL_ERROR, "Too much data !!!\n");
  59
  60   /* Get the data in the driver */
  61   if(copy_from_user(command, buf, count))
  62     {
  63       DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
  64       return -EFAULT;
  65     }
  66
  67   /* Safe terminate the string */
  68   command[count] = '\0';
  69   DEBUG(CTRL_INFO, "Command line received is ``%s'' (%Zd).\n",
  70         command, count);
  71
  72   /* Check every commands in the command line */
  73   next = command;
  74   while(next != NULL)
  75     {
  76       /* Look at the next command */
  77       start = next;
  78
  79         /* Scrap whitespaces before the command */
  80         start = skip_spaces(start);
  81
  82       /* ',' is our command separator */
  83       next = strchr(start, ',');
  84       if(next)
  85         {
  86           *next = '\0';                 /* Terminate command */
  87           length = next - start;        /* Length */
  88           next++;                       /* Skip the '\0' */
  89         }
  90       else
  91         length = strlen(start);
  92
  93       DEBUG(CTRL_INFO, "Found command ``%s'' (%d).\n", start, length);
  94
  95       /* Check if we recognised one of the known command
  96        * We can't use "switch" with strings, so hack with "continue" */
  97
  98       /* First command : name -> Requested IrDA nickname */
  99       if(!strncmp(start, "name", 4))
 100         {
 101           /* Copy the name only if is included and not "any" */
 102           if((length > 5) && (strcmp(start + 5, "any")))
 103             {
 104               /* Strip out trailing whitespaces */
 105               while(isspace(start[length - 1]))
 106                 length--;
 107
 108               DABORT(length < 5 || length > NICKNAME_MAX_LEN + 5,
 109                      -EINVAL, CTRL_ERROR, "Invalid nickname.\n");
 110
 111               /* Copy the name for later reuse */
 112               memcpy(ap->rname, start + 5, length - 5);
 113               ap->rname[length - 5] = '\0';
 114             }
 115           else
 116             ap->rname[0] = '\0';
 117           DEBUG(CTRL_INFO, "Got rname = ``%s''\n", ap->rname);
 118
 119           /* Restart the loop */
 120           continue;
 121         }
 122
 123       /* Second command : addr, daddr -> Requested IrDA destination address
 124        * Also process : saddr -> Requested IrDA source address */
 125       if((!strncmp(start, "addr", 4)) ||
 126          (!strncmp(start, "daddr", 5)) ||
 127          (!strncmp(start, "saddr", 5)))
 128         {
 129           __u32         addr = DEV_ADDR_ANY;
 130
 131           /* Copy the address only if is included and not "any" */
 132           if((length > 5) && (strcmp(start + 5, "any")))
 133             {
 134               char *    begp = start + 5;
 135               char *    endp;
 136
 137               /* Scrap whitespaces before the command */
 138               begp = skip_spaces(begp);
 139
 140               /* Convert argument to a number (last arg is the base) */
 141               addr = simple_strtoul(begp, &endp, 16);
 142               /* Has it worked  ? (endp should be start + length) */
 143               DABORT(endp <= (start + 5), -EINVAL,
 144                      CTRL_ERROR, "Invalid address.\n");
 145             }
 146           /* Which type of address ? */
 147           if(start[0] == 's')
 148             {
 149               /* Save it */
 150               ap->rsaddr = addr;
 151               DEBUG(CTRL_INFO, "Got rsaddr = %08x\n", ap->rsaddr);
 152             }
 153           else
 154             {
 155               /* Save it */
 156               ap->rdaddr = addr;
 157               DEBUG(CTRL_INFO, "Got rdaddr = %08x\n", ap->rdaddr);
 158             }
 159
 160           /* Restart the loop */
 161           continue;
 162         }
 163
 164       /* Other possible command : connect N (number of retries) */
 165
 166       /* No command matched -> Failed... */
 167       DABORT(1, -EINVAL, CTRL_ERROR, "Not a recognised IrNET command.\n");
 168     }
 169
 170   /* Success : we have parsed all commands successfully */
 171   return count;
 172 }
 173
 174 #ifdef INITIAL_DISCOVERY
 175 /*------------------------------------------------------------------*/
 176 /*
 177  * Function irnet_get_discovery_log (self)
 178  *
 179  *    Query the content on the discovery log if not done
 180  *
 181  * This function query the current content of the discovery log
 182  * at the startup of the event channel and save it in the internal struct.
 183  */
 184 static void
 185 irnet_get_discovery_log(irnet_socket *  ap)
 186 {
 187   __u16         mask = irlmp_service_to_hint(S_LAN);
 188
 189   /* Ask IrLMP for the current discovery log */
 190   ap->discoveries = irlmp_get_discoveries(&ap->disco_number, mask,
 191                                           DISCOVERY_DEFAULT_SLOTS);
 192
 193   /* Check if the we got some results */
 194   if(ap->discoveries == NULL)
 195     ap->disco_number = -1;
 196
 197   DEBUG(CTRL_INFO, "Got the log (0x%p), size is %d\n",
 198         ap->discoveries, ap->disco_number);
 199 }
 200
 201 /*------------------------------------------------------------------*/
 202 /*
 203  * Function irnet_read_discovery_log (self, event)
 204  *
 205  *    Read the content on the discovery log
 206  *
 207  * This function dump the current content of the discovery log
 208  * at the startup of the event channel.
 209  * Return 1 if wrote an event on the control channel...
 210  *
 211  * State of the ap->disco_XXX variables :
 212  * Socket creation :  discoveries = NULL ; disco_index = 0 ; disco_number = 0
 213  * While reading :    discoveries = ptr  ; disco_index = X ; disco_number = Y
 214  * After reading :    discoveries = NULL ; disco_index = Y ; disco_number = -1
 215  */
 216 static inline int
 217 irnet_read_discovery_log(irnet_socket * ap,
 218                          char *         event)
 219 {
 220   int           done_event = 0;
 221
 222   DENTER(CTRL_TRACE, "(ap=0x%p, event=0x%p)\n",
 223          ap, event);
 224
 225   /* Test if we have some work to do or we have already finished */
 226   if(ap->disco_number == -1)
 227     {
 228       DEBUG(CTRL_INFO, "Already done\n");
 229       return 0;
 230     }
 231
 232   /* Test if it's the first time and therefore we need to get the log */
 233   if(ap->discoveries == NULL)
 234     irnet_get_discovery_log(ap);
 235
 236   /* Check if we have more item to dump */
 237   if(ap->disco_index < ap->disco_number)
 238     {
 239       /* Write an event */
 240       sprintf(event, "Found %08x (%s) behind %08x {hints %02X-%02X}\n",
 241               ap->discoveries[ap->disco_index].daddr,
 242               ap->discoveries[ap->disco_index].info,
 243               ap->discoveries[ap->disco_index].saddr,
 244               ap->discoveries[ap->disco_index].hints[0],
 245               ap->discoveries[ap->disco_index].hints[1]);
 246       DEBUG(CTRL_INFO, "Writing discovery %d : %s\n",
 247             ap->disco_index, ap->discoveries[ap->disco_index].info);
 248
 249       /* We have an event */
 250       done_event = 1;
 251       /* Next discovery */
 252       ap->disco_index++;
 253     }
 254
 255   /* Check if we have done the last item */
 256   if(ap->disco_index >= ap->disco_number)
 257     {
 258       /* No more items : remove the log and signal termination */
 259       DEBUG(CTRL_INFO, "Cleaning up log (0x%p)\n",
 260             ap->discoveries);
 261       if(ap->discoveries != NULL)
 262         {
 263           /* Cleanup our copy of the discovery log */
 264           kfree(ap->discoveries);
 265           ap->discoveries = NULL;
 266         }
 267       ap->disco_number = -1;
 268     }
 269
 270   return done_event;
 271 }
 272 #endif /* INITIAL_DISCOVERY */
 273
 274 /*------------------------------------------------------------------*/
 275 /*
 276  * Read is used to get IrNET events
 277  */
 278 static inline ssize_t
 279 irnet_ctrl_read(irnet_socket *  ap,
 280                 struct file *   file,
 281                 char __user *   buf,
 282                 size_t          count)
 283 {
 284   DECLARE_WAITQUEUE(wait, current);
 285   char          event[64];      /* Max event is 61 char */
 286   ssize_t       ret = 0;
 287
 288   DENTER(CTRL_TRACE, "(ap=0x%p, count=%Zd)\n", ap, count);
 289
 290   /* Check if we can write an event out in one go */
 291   DABORT(count < sizeof(event), -EOVERFLOW, CTRL_ERROR, "Buffer to small.\n");
 292
 293 #ifdef INITIAL_DISCOVERY
 294   /* Check if we have read the log */
 295   if(irnet_read_discovery_log(ap, event))
 296     {
 297       /* We have an event !!! Copy it to the user */
 298       if(copy_to_user(buf, event, strlen(event)))
 299         {
 300           DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
 301           return -EFAULT;
 302         }
 303
 304       DEXIT(CTRL_TRACE, "\n");
 305       return strlen(event);
 306     }
 307 #endif /* INITIAL_DISCOVERY */
 308
 309   /* Put ourselves on the wait queue to be woken up */
 310   add_wait_queue(&irnet_events.rwait, &wait);
 311   current->state = TASK_INTERRUPTIBLE;
 312   for(;;)
 313     {
 314       /* If there is unread events */
 315       ret = 0;
 316       if(ap->event_index != irnet_events.index)
 317         break;
 318       ret = -EAGAIN;
 319       if(file->f_flags & O_NONBLOCK)
 320         break;
 321       ret = -ERESTARTSYS;
 322       if(signal_pending(current))
 323         break;
 324       /* Yield and wait to be woken up */
 325       schedule();
 326     }
 327   current->state = TASK_RUNNING;
 328   remove_wait_queue(&irnet_events.rwait, &wait);
 329
 330   /* Did we got it ? */
 331   if(ret != 0)
 332     {
 333       /* No, return the error code */
 334       DEXIT(CTRL_TRACE, " - ret %Zd\n", ret);
 335       return ret;
 336     }
 337
 338   /* Which event is it ? */
 339   switch(irnet_events.log[ap->event_index].event)
 340     {
 341     case IRNET_DISCOVER:
 342       sprintf(event, "Discovered %08x (%s) behind %08x {hints %02X-%02X}\n",
 343               irnet_events.log[ap->event_index].daddr,
 344               irnet_events.log[ap->event_index].name,
 345               irnet_events.log[ap->event_index].saddr,
 346               irnet_events.log[ap->event_index].hints.byte[0],
 347               irnet_events.log[ap->event_index].hints.byte[1]);
 348       break;
 349     case IRNET_EXPIRE:
 350       sprintf(event, "Expired %08x (%s) behind %08x {hints %02X-%02X}\n",
 351               irnet_events.log[ap->event_index].daddr,
 352               irnet_events.log[ap->event_index].name,
 353               irnet_events.log[ap->event_index].saddr,
 354               irnet_events.log[ap->event_index].hints.byte[0],
 355               irnet_events.log[ap->event_index].hints.byte[1]);
 356       break;
 357     case IRNET_CONNECT_TO:
 358       sprintf(event, "Connected to %08x (%s) on ppp%d\n",
 359               irnet_events.log[ap->event_index].daddr,
 360               irnet_events.log[ap->event_index].name,
 361               irnet_events.log[ap->event_index].unit);
 362       break;
 363     case IRNET_CONNECT_FROM:
 364       sprintf(event, "Connection from %08x (%s) on ppp%d\n",
 365               irnet_events.log[ap->event_index].daddr,
 366               irnet_events.log[ap->event_index].name,
 367               irnet_events.log[ap->event_index].unit);
 368       break;
 369     case IRNET_REQUEST_FROM:
 370       sprintf(event, "Request from %08x (%s) behind %08x\n",
 371               irnet_events.log[ap->event_index].daddr,
 372               irnet_events.log[ap->event_index].name,
 373               irnet_events.log[ap->event_index].saddr);
 374       break;
 375     case IRNET_NOANSWER_FROM:
 376       sprintf(event, "No-answer from %08x (%s) on ppp%d\n",
 377               irnet_events.log[ap->event_index].daddr,
 378               irnet_events.log[ap->event_index].name,
 379               irnet_events.log[ap->event_index].unit);
 380       break;
 381     case IRNET_BLOCKED_LINK:
 382       sprintf(event, "Blocked link with %08x (%s) on ppp%d\n",
 383               irnet_events.log[ap->event_index].daddr,
 384               irnet_events.log[ap->event_index].name,
 385               irnet_events.log[ap->event_index].unit);
 386       break;
 387     case IRNET_DISCONNECT_FROM:
 388       sprintf(event, "Disconnection from %08x (%s) on ppp%d\n",
 389               irnet_events.log[ap->event_index].daddr,
 390               irnet_events.log[ap->event_index].name,
 391               irnet_events.log[ap->event_index].unit);
 392       break;
 393     case IRNET_DISCONNECT_TO:
 394       sprintf(event, "Disconnected to %08x (%s)\n",
 395               irnet_events.log[ap->event_index].daddr,
 396               irnet_events.log[ap->event_index].name);
 397       break;
 398     default:
 399       sprintf(event, "Bug\n");
 400     }
 401   /* Increment our event index */
 402   ap->event_index = (ap->event_index + 1) % IRNET_MAX_EVENTS;
 403
 404   DEBUG(CTRL_INFO, "Event is :%s", event);
 405
 406   /* Copy it to the user */
 407   if(copy_to_user(buf, event, strlen(event)))
 408     {
 409       DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
 410       return -EFAULT;
 411     }
 412
 413   DEXIT(CTRL_TRACE, "\n");
 414   return strlen(event);
 415 }
 416
 417 /*------------------------------------------------------------------*/
 418 /*
 419  * Poll : called when someone do a select on /dev/irnet.
 420  * Just check if there are new events...
 421  */
 422 static inline unsigned int
 423 irnet_ctrl_poll(irnet_socket *  ap,
 424                 struct file *   file,
 425                 poll_table *    wait)
 426 {
 427   unsigned int mask;
 428
 429   DENTER(CTRL_TRACE, "(ap=0x%p)\n", ap);
 430
 431   poll_wait(file, &irnet_events.rwait, wait);
 432   mask = POLLOUT | POLLWRNORM;
 433   /* If there is unread events */
 434   if(ap->event_index != irnet_events.index)
 435     mask |= POLLIN | POLLRDNORM;
 436 #ifdef INITIAL_DISCOVERY
 437   if(ap->disco_number != -1)
 438     {
 439       /* Test if it's the first time and therefore we need to get the log */
 440       if(ap->discoveries == NULL)
 441         irnet_get_discovery_log(ap);
 442       /* Recheck */
 443       if(ap->disco_number != -1)
 444         mask |= POLLIN | POLLRDNORM;
 445     }
 446 #endif /* INITIAL_DISCOVERY */
 447
 448   DEXIT(CTRL_TRACE, " - mask=0x%X\n", mask);
 449   return mask;
 450 }
 451
 452
 453 /*********************** FILESYSTEM CALLBACKS ***********************/
 454 /*
 455  * Implement the usual open, read, write functions that will be called
 456  * by the file system when some action is performed on /dev/irnet.
 457  * Most of those actions will in fact be performed by "pppd" or
 458  * the control channel, we just act as a redirector...
 459  */
 460
 461 /*------------------------------------------------------------------*/
 462 /*
 463  * Open : when somebody open /dev/irnet
 464  * We basically create a new instance of irnet and initialise it.
 465  */
 466 static int
 467 dev_irnet_open(struct inode *   inode,
 468                struct file *    file)
 469 {
 470   struct irnet_socket * ap;
 471   int                   err;
 472
 473   DENTER(FS_TRACE, "(file=0x%p)\n", file);
 474
 475 #ifdef SECURE_DEVIRNET
 476   /* This could (should?) be enforced by the permissions on /dev/irnet. */
 477   if(!capable(CAP_NET_ADMIN))
 478     return -EPERM;
 479 #endif /* SECURE_DEVIRNET */
 480
 481   /* Allocate a private structure for this IrNET instance */
 482   ap = kzalloc(sizeof(*ap), GFP_KERNEL);
 483   DABORT(ap == NULL, -ENOMEM, FS_ERROR, "Can't allocate struct irnet...\n");
 484
 485   /* initialize the irnet structure */
 486   ap->file = file;
 487
 488   /* PPP channel setup */
 489   ap->ppp_open = 0;
 490   ap->chan.private = ap;
 491   ap->chan.ops = &irnet_ppp_ops;
 492   ap->chan.mtu = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
 493   ap->chan.hdrlen = 2 + TTP_MAX_HEADER;         /* for A/C + Max IrDA hdr */
 494   /* PPP parameters */
 495   ap->mru = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
 496   ap->xaccm[0] = ~0U;
 497   ap->xaccm[3] = 0x60000000U;
 498   ap->raccm = ~0U;
 499
 500   /* Setup the IrDA part... */
 501   err = irda_irnet_create(ap);
 502   if(err)
 503     {
 504       DERROR(FS_ERROR, "Can't setup IrDA link...\n");
 505       kfree(ap);
 506
 507       return err;
 508     }
 509
 510   /* For the control channel */
 511   ap->event_index = irnet_events.index; /* Cancel all past events */
 512
 513   mutex_init(&ap->lock);
 514
 515   /* Put our stuff where we will be able to find it later */
 516   file->private_data = ap;
 517
 518   DEXIT(FS_TRACE, " - ap=0x%p\n", ap);
 519
 520   return 0;
 521 }
 522
 523
 524 /*------------------------------------------------------------------*/
 525 /*
 526  * Close : when somebody close /dev/irnet
 527  * Destroy the instance of /dev/irnet
 528  */
 529 static int
 530 dev_irnet_close(struct inode *  inode,
 531                 struct file *   file)
 532 {
 533   irnet_socket *        ap = file->private_data;
 534
 535   DENTER(FS_TRACE, "(file=0x%p, ap=0x%p)\n",
 536          file, ap);
 537   DABORT(ap == NULL, 0, FS_ERROR, "ap is NULL !!!\n");
 538
 539   /* Detach ourselves */
 540   file->private_data = NULL;
 541
 542   /* Close IrDA stuff */
 543   irda_irnet_destroy(ap);
 544
 545   /* Disconnect from the generic PPP layer if not already done */
 546   if(ap->ppp_open)
 547     {
 548       DERROR(FS_ERROR, "Channel still registered - deregistering !\n");
 549       ap->ppp_open = 0;
 550       ppp_unregister_channel(&ap->chan);
 551     }
 552
 553   kfree(ap);
 554
 555   DEXIT(FS_TRACE, "\n");
 556   return 0;
 557 }
 558
 559 /*------------------------------------------------------------------*/
 560 /*
 561  * Write does nothing.
 562  * (we receive packet from ppp_generic through ppp_irnet_send())
 563  */
 564 static ssize_t
 565 dev_irnet_write(struct file *   file,
 566                 const char __user *buf,
 567                 size_t          count,
 568                 loff_t *        ppos)
 569 {
 570   irnet_socket *        ap = file->private_data;
 571
 572   DPASS(FS_TRACE, "(file=0x%p, ap=0x%p, count=%Zd)\n",
 573         file, ap, count);
 574   DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");
 575
 576   /* If we are connected to ppp_generic, let it handle the job */
 577   if(ap->ppp_open)
 578     return -EAGAIN;
 579   else
 580     return irnet_ctrl_write(ap, buf, count);
 581 }
 582
 583 /*------------------------------------------------------------------*/
 584 /*
 585  * Read doesn't do much either.
 586  * (pppd poll us, but ultimately reads through /dev/ppp)
 587  */
 588 static ssize_t
 589 dev_irnet_read(struct file *    file,
 590                char __user *    buf,
 591                size_t           count,
 592                loff_t *         ppos)
 593 {
 594   irnet_socket *        ap = file->private_data;
 595
 596   DPASS(FS_TRACE, "(file=0x%p, ap=0x%p, count=%Zd)\n",
 597         file, ap, count);
 598   DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");
 599
 600   /* If we are connected to ppp_generic, let it handle the job */
 601   if(ap->ppp_open)
 602     return -EAGAIN;
 603   else
 604     return irnet_ctrl_read(ap, file, buf, count);
 605 }
 606
 607 /*------------------------------------------------------------------*/
 608 /*
 609  * Poll : called when someone do a select on /dev/irnet
 610  */
 611 static unsigned int
 612 dev_irnet_poll(struct file *    file,
 613                poll_table *     wait)
 614 {
 615   irnet_socket *        ap = file->private_data;
 616   unsigned int          mask;
 617
 618   DENTER(FS_TRACE, "(file=0x%p, ap=0x%p)\n",
 619          file, ap);
 620
 621   mask = POLLOUT | POLLWRNORM;
 622   DABORT(ap == NULL, mask, FS_ERROR, "ap is NULL !!!\n");
 623
 624   /* If we are connected to ppp_generic, let it handle the job */
 625   if(!ap->ppp_open)
 626     mask |= irnet_ctrl_poll(ap, file, wait);
 627
 628   DEXIT(FS_TRACE, " - mask=0x%X\n", mask);
 629   return mask;
 630 }
 631
 632 /*------------------------------------------------------------------*/
 633 /*
 634  * IOCtl : Called when someone does some ioctls on /dev/irnet
 635  * This is the way pppd configure us and control us while the PPP
 636  * instance is active.
 637  */
 638 static long
 639 dev_irnet_ioctl(
 640                 struct file *   file,
 641                 unsigned int    cmd,
 642                 unsigned long   arg)
 643 {
 644   irnet_socket *        ap = file->private_data;
 645   int                   err;
 646   int                   val;
 647   void __user *argp = (void __user *)arg;
 648
 649   DENTER(FS_TRACE, "(file=0x%p, ap=0x%p, cmd=0x%X)\n",
 650          file, ap, cmd);
 651
 652   /* Basic checks... */
 653   DASSERT(ap != NULL, -ENXIO, PPP_ERROR, "ap is NULL...\n");
 654 #ifdef SECURE_DEVIRNET
 655   if(!capable(CAP_NET_ADMIN))
 656     return -EPERM;
 657 #endif /* SECURE_DEVIRNET */
 658
 659   err = -EFAULT;
 660   switch(cmd)
 661     {
 662       /* Set discipline (should be N_SYNC_PPP or N_TTY) */
 663     case TIOCSETD:
 664       if(get_user(val, (int __user *)argp))
 665         break;
 666       if((val == N_SYNC_PPP) || (val == N_PPP))
 667         {
 668           DEBUG(FS_INFO, "Entering PPP discipline.\n");
 669           /* PPP channel setup (ap->chan in configured in dev_irnet_open())*/
 670           if (mutex_lock_interruptible(&ap->lock))
 671                   return -EINTR;
 672
 673           err = ppp_register_channel(&ap->chan);
 674           if(err == 0)
 675             {
 676               /* Our ppp side is active */
 677               ap->ppp_open = 1;
 678
 679               DEBUG(FS_INFO, "Trying to establish a connection.\n");
 680               /* Setup the IrDA link now - may fail... */
 681               irda_irnet_connect(ap);
 682             }
 683           else
 684             DERROR(FS_ERROR, "Can't setup PPP channel...\n");
 685
 686           mutex_unlock(&ap->lock);
 687         }
 688       else
 689         {
 690           /* In theory, should be N_TTY */
 691           DEBUG(FS_INFO, "Exiting PPP discipline.\n");
 692           /* Disconnect from the generic PPP layer */
 693           if (mutex_lock_interruptible(&ap->lock))
 694                   return -EINTR;
 695
 696           if(ap->ppp_open)
 697             {
 698               ap->ppp_open = 0;
 699               ppp_unregister_channel(&ap->chan);
 700             }
 701           else
 702             DERROR(FS_ERROR, "Channel not registered !\n");
 703           err = 0;
 704
 705           mutex_unlock(&ap->lock);
 706         }
 707       break;
 708
 709       /* Query PPP channel and unit number */
 710     case PPPIOCGCHAN:
 711       if (mutex_lock_interruptible(&ap->lock))
 712               return -EINTR;
 713
 714       if(ap->ppp_open && !put_user(ppp_channel_index(&ap->chan),
 715                                                 (int __user *)argp))
 716         err = 0;
 717
 718       mutex_unlock(&ap->lock);
 719       break;
 720     case PPPIOCGUNIT:
 721       if (mutex_lock_interruptible(&ap->lock))
 722               return -EINTR;
 723
 724       if(ap->ppp_open && !put_user(ppp_unit_number(&ap->chan),
 725                                                 (int __user *)argp))
 726         err = 0;
 727
 728       mutex_unlock(&ap->lock);
 729       break;
 730
 731       /* All these ioctls can be passed both directly and from ppp_generic,
 732        * so we just deal with them in one place...
 733        */
 734     case PPPIOCGFLAGS:
 735     case PPPIOCSFLAGS:
 736     case PPPIOCGASYNCMAP:
 737     case PPPIOCSASYNCMAP:
 738     case PPPIOCGRASYNCMAP:
 739     case PPPIOCSRASYNCMAP:
 740     case PPPIOCGXASYNCMAP:
 741     case PPPIOCSXASYNCMAP:
 742     case PPPIOCGMRU:
 743     case PPPIOCSMRU:
 744       DEBUG(FS_INFO, "Standard PPP ioctl.\n");
 745       if(!capable(CAP_NET_ADMIN))
 746         err = -EPERM;
 747       else {
 748         if (mutex_lock_interruptible(&ap->lock))
 749               return -EINTR;
 750
 751         err = ppp_irnet_ioctl(&ap->chan, cmd, arg);
 752
 753         mutex_unlock(&ap->lock);
 754       }
 755       break;
 756
 757       /* TTY IOCTLs : Pretend that we are a tty, to keep pppd happy */
 758       /* Get termios */
 759     case TCGETS:
 760       DEBUG(FS_INFO, "Get termios.\n");
 761       if (mutex_lock_interruptible(&ap->lock))
 762               return -EINTR;
 763
 764 #ifndef TCGETS2
 765       if(!kernel_termios_to_user_termios((struct termios __user *)argp, &ap->termios))
 766         err = 0;
 767 #else
 768       if(kernel_termios_to_user_termios_1((struct termios __user *)argp, &ap->termios))
 769         err = 0;
 770 #endif
 771
 772       mutex_unlock(&ap->lock);
 773       break;
 774       /* Set termios */
 775     case TCSETSF:
 776       DEBUG(FS_INFO, "Set termios.\n");
 777       if (mutex_lock_interruptible(&ap->lock))
 778               return -EINTR;
 779
 780 #ifndef TCGETS2
 781       if(!user_termios_to_kernel_termios(&ap->termios, (struct termios __user *)argp))
 782         err = 0;
 783 #else
 784       if(!user_termios_to_kernel_termios_1(&ap->termios, (struct termios __user *)argp))
 785         err = 0;
 786 #endif
 787
 788       mutex_unlock(&ap->lock);
 789       break;
 790
 791       /* Set DTR/RTS */
 792     case TIOCMBIS:
 793     case TIOCMBIC:
 794       /* Set exclusive/non-exclusive mode */
 795     case TIOCEXCL:
 796     case TIOCNXCL:
 797       DEBUG(FS_INFO, "TTY compatibility.\n");
 798       err = 0;
 799       break;
 800
 801     case TCGETA:
 802       DEBUG(FS_INFO, "TCGETA\n");
 803       break;
 804
 805     case TCFLSH:
 806       DEBUG(FS_INFO, "TCFLSH\n");
 807       /* Note : this will flush buffers in PPP, so it *must* be done
 808        * We should also worry that we don't accept junk here and that
 809        * we get rid of our own buffers */
 810 #ifdef FLUSH_TO_PPP
 811       if (mutex_lock_interruptible(&ap->lock))
 812               return -EINTR;
 813       ppp_output_wakeup(&ap->chan);
 814       mutex_unlock(&ap->lock);
 815 #endif /* FLUSH_TO_PPP */
 816       err = 0;
 817       break;
 818
 819     case FIONREAD:
 820       DEBUG(FS_INFO, "FIONREAD\n");
 821       val = 0;
 822       if(put_user(val, (int __user *)argp))
 823         break;
 824       err = 0;
 825       break;
 826
 827     default:
 828       DERROR(FS_ERROR, "Unsupported ioctl (0x%X)\n", cmd);
 829       err = -ENOTTY;
 830     }
 831
 832   DEXIT(FS_TRACE, " - err = 0x%X\n", err);
 833   return err;
 834 }
 835
 836 /************************** PPP CALLBACKS **************************/
 837 /*
 838  * This are the functions that the generic PPP driver in the kernel
 839  * will call to communicate to us.
 840  */
 841
 842 /*------------------------------------------------------------------*/
 843 /*
 844  * Prepare the ppp frame for transmission over the IrDA socket.
 845  * We make sure that the header space is enough, and we change ppp header
 846  * according to flags passed by pppd.
 847  * This is not a callback, but just a helper function used in ppp_irnet_send()
 848  */
 849 static inline struct sk_buff *
 850 irnet_prepare_skb(irnet_socket *        ap,
 851                   struct sk_buff *      skb)
 852 {
 853   unsigned char *       data;
 854   int                   proto;          /* PPP protocol */
 855   int                   islcp;          /* Protocol == LCP */
 856   int                   needaddr;       /* Need PPP address */
 857
 858   DENTER(PPP_TRACE, "(ap=0x%p, skb=0x%p)\n",
 859          ap, skb);
 860
 861   /* Extract PPP protocol from the frame */
 862   data  = skb->data;
 863   proto = (data[0] << 8) + data[1];
 864
 865   /* LCP packets with codes between 1 (configure-request)
 866    * and 7 (code-reject) must be sent as though no options
 867    * have been negotiated. */
 868   islcp = (proto == PPP_LCP) && (1 <= data[2]) && (data[2] <= 7);
 869
 870   /* compress protocol field if option enabled */
 871   if((data[0] == 0) && (ap->flags & SC_COMP_PROT) && (!islcp))
 872     skb_pull(skb,1);
 873
 874   /* Check if we need address/control fields */
 875   needaddr = 2*((ap->flags & SC_COMP_AC) == 0 || islcp);
 876
 877   /* Is the skb headroom large enough to contain all IrDA-headers? */
 878   if((skb_headroom(skb) < (ap->max_header_size + needaddr)) ||
 879       (skb_shared(skb)))
 880     {
 881       struct sk_buff *  new_skb;
 882
 883       DEBUG(PPP_INFO, "Reallocating skb\n");
 884
 885       /* Create a new skb */
 886       new_skb = skb_realloc_headroom(skb, ap->max_header_size + needaddr);
 887
 888       /* We have to free the original skb anyway */
 889       dev_kfree_skb(skb);
 890
 891       /* Did the realloc succeed ? */
 892       DABORT(new_skb == NULL, NULL, PPP_ERROR, "Could not realloc skb\n");
 893
 894       /* Use the new skb instead */
 895       skb = new_skb;
 896     }
 897
 898   /* prepend address/control fields if necessary */
 899   if(needaddr)
 900     {
 901       skb_push(skb, 2);
 902       skb->data[0] = PPP_ALLSTATIONS;
 903       skb->data[1] = PPP_UI;
 904     }
 905
 906   DEXIT(PPP_TRACE, "\n");
 907
 908   return skb;
 909 }
 910
 911 /*------------------------------------------------------------------*/
 912 /*
 913  * Send a packet to the peer over the IrTTP connection.
 914  * Returns 1 iff the packet was accepted.
 915  * Returns 0 iff packet was not consumed.
 916  * If the packet was not accepted, we will call ppp_output_wakeup
 917  * at some later time to reactivate flow control in ppp_generic.
 918  */
 919 static int
 920 ppp_irnet_send(struct ppp_channel *     chan,
 921                struct sk_buff *         skb)
 922 {
 923   irnet_socket *        self = (struct irnet_socket *) chan->private;
 924   int                   ret;
 925
 926   DENTER(PPP_TRACE, "(channel=0x%p, ap/self=0x%p)\n",
 927          chan, self);
 928
 929   /* Check if things are somewhat valid... */
 930   DASSERT(self != NULL, 0, PPP_ERROR, "Self is NULL !!!\n");
 931
 932   /* Check if we are connected */
 933   if(!(test_bit(0, &self->ttp_open)))
 934     {
 935 #ifdef CONNECT_IN_SEND
 936       /* Let's try to connect one more time... */
 937       /* Note : we won't be connected after this call, but we should be
 938        * ready for next packet... */
 939       /* If we are already connecting, this will fail */
 940       irda_irnet_connect(self);
 941 #endif /* CONNECT_IN_SEND */
 942
 943       DEBUG(PPP_INFO, "IrTTP not ready ! (%ld-%ld)\n",
 944             self->ttp_open, self->ttp_connect);
 945
 946       /* Note : we can either drop the packet or block the packet.
 947        *
 948        * Blocking the packet allow us a better connection time,
 949        * because by calling ppp_output_wakeup() we can have
 950        * ppp_generic resending the LCP request immediately to us,
 951        * rather than waiting for one of pppd periodic transmission of
 952        * LCP request.
 953        *
 954        * On the other hand, if we block all packet, all those periodic
 955        * transmissions of pppd accumulate in ppp_generic, creating a
 956        * backlog of LCP request. When we eventually connect later on,
 957        * we have to transmit all this backlog before we can connect
 958        * proper (if we don't timeout before).
 959        *
 960        * The current strategy is as follow :
 961        * While we are attempting to connect, we block packets to get
 962        * a better connection time.
 963        * If we fail to connect, we drain the queue and start dropping packets
 964        */
 965 #ifdef BLOCK_WHEN_CONNECT
 966       /* If we are attempting to connect */
 967       if(test_bit(0, &self->ttp_connect))
 968         {
 969           /* Blocking packet, ppp_generic will retry later */
 970           return 0;
 971         }
 972 #endif /* BLOCK_WHEN_CONNECT */
 973
 974       /* Dropping packet, pppd will retry later */
 975       dev_kfree_skb(skb);
 976       return 1;
 977     }
 978
 979   /* Check if the queue can accept any packet, otherwise block */
 980   if(self->tx_flow != FLOW_START)
 981     DRETURN(0, PPP_INFO, "IrTTP queue full (%d skbs)...\n",
 982             skb_queue_len(&self->tsap->tx_queue));
 983
 984   /* Prepare ppp frame for transmission */
 985   skb = irnet_prepare_skb(self, skb);
 986   DABORT(skb == NULL, 1, PPP_ERROR, "Prepare skb for Tx failed.\n");
 987
 988   /* Send the packet to IrTTP */
 989   ret = irttp_data_request(self->tsap, skb);
 990   if(ret < 0)
 991     {
 992       /*
 993        * > IrTTPs tx queue is full, so we just have to
 994        * > drop the frame! You might think that we should
 995        * > just return -1 and don't deallocate the frame,
 996        * > but that is dangerous since it's possible that
 997        * > we have replaced the original skb with a new
 998        * > one with larger headroom, and that would really
 999        * > confuse do_dev_queue_xmit() in dev.c! I have
1000        * > tried :-) DB
1001        * Correction : we verify the flow control above (self->tx_flow),
1002        * so we come here only if IrTTP doesn't like the packet (empty,
1003        * too large, IrTTP not connected). In those rare cases, it's ok
1004        * to drop it, we don't want to see it here again...
1005        * Jean II
1006        */
1007       DERROR(PPP_ERROR, "IrTTP doesn't like this packet !!! (0x%X)\n", ret);
1008       /* irttp_data_request already free the packet */
1009     }
1010
1011   DEXIT(PPP_TRACE, "\n");
1012   return 1;     /* Packet has been consumed */
1013 }
1014
1015 /*------------------------------------------------------------------*/
1016 /*
1017  * Take care of the ioctls that ppp_generic doesn't want to deal with...
1018  * Note : we are also called from dev_irnet_ioctl().
1019  */
1020 static int
1021 ppp_irnet_ioctl(struct ppp_channel *    chan,
1022                 unsigned int            cmd,
1023                 unsigned long           arg)
1024 {
1025   irnet_socket *        ap = (struct irnet_socket *) chan->private;
1026   int                   err;
1027   int                   val;
1028   u32                   accm[8];
1029   void __user *argp = (void __user *)arg;
1030
1031   DENTER(PPP_TRACE, "(channel=0x%p, ap=0x%p, cmd=0x%X)\n",
1032          chan, ap, cmd);
1033
1034   /* Basic checks... */
1035   DASSERT(ap != NULL, -ENXIO, PPP_ERROR, "ap is NULL...\n");
1036
1037   err = -EFAULT;
1038   switch(cmd)
1039     {
1040       /* PPP flags */
1041     case PPPIOCGFLAGS:
1042       val = ap->flags | ap->rbits;
1043       if(put_user(val, (int __user *) argp))
1044         break;
1045       err = 0;
1046       break;
1047     case PPPIOCSFLAGS:
1048       if(get_user(val, (int __user *) argp))
1049         break;
1050       ap->flags = val & ~SC_RCV_BITS;
1051       ap->rbits = val & SC_RCV_BITS;
1052       err = 0;
1053       break;
1054
1055       /* Async map stuff - all dummy to please pppd */
1056     case PPPIOCGASYNCMAP:
1057       if(put_user(ap->xaccm[0], (u32 __user *) argp))
1058         break;
1059       err = 0;
1060       break;
1061     case PPPIOCSASYNCMAP:
1062       if(get_user(ap->xaccm[0], (u32 __user *) argp))
1063         break;
1064       err = 0;
1065       break;
1066     case PPPIOCGRASYNCMAP:
1067       if(put_user(ap->raccm, (u32 __user *) argp))
1068         break;
1069       err = 0;
1070       break;
1071     case PPPIOCSRASYNCMAP:
1072       if(get_user(ap->raccm, (u32 __user *) argp))
1073         break;
1074       err = 0;
1075       break;
1076     case PPPIOCGXASYNCMAP:
1077       if(copy_to_user(argp, ap->xaccm, sizeof(ap->xaccm)))
1078         break;
1079       err = 0;
1080       break;
1081     case PPPIOCSXASYNCMAP:
1082       if(copy_from_user(accm, argp, sizeof(accm)))
1083         break;
1084       accm[2] &= ~0x40000000U;          /* can't escape 0x5e */
1085       accm[3] |= 0x60000000U;           /* must escape 0x7d, 0x7e */
1086       memcpy(ap->xaccm, accm, sizeof(ap->xaccm));
1087       err = 0;
1088       break;
1089
1090       /* Max PPP frame size */
1091     case PPPIOCGMRU:
1092       if(put_user(ap->mru, (int __user *) argp))
1093         break;
1094       err = 0;
1095       break;
1096     case PPPIOCSMRU:
1097       if(get_user(val, (int __user *) argp))
1098         break;
1099       if(val < PPP_MRU)
1100         val = PPP_MRU;
1101       ap->mru = val;
1102       err = 0;
1103       break;
1104
1105     default:
1106       DEBUG(PPP_INFO, "Unsupported ioctl (0x%X)\n", cmd);
1107       err = -ENOIOCTLCMD;
1108     }
1109
1110   DEXIT(PPP_TRACE, " - err = 0x%X\n", err);
1111   return err;
1112 }
1113
1114 /************************** INITIALISATION **************************/
1115 /*
1116  * Module initialisation and all that jazz...
1117  */
1118
1119 /*------------------------------------------------------------------*/
1120 /*
1121  * Hook our device callbacks in the filesystem, to connect our code
1122  * to /dev/irnet
1123  */
1124 static inline int __init
1125 ppp_irnet_init(void)
1126 {
1127   int err = 0;
1128
1129   DENTER(MODULE_TRACE, "()\n");
1130
1131   /* Allocate ourselves as a minor in the misc range */
1132   err = misc_register(&irnet_misc_device);
1133
1134   DEXIT(MODULE_TRACE, "\n");
1135   return err;
1136 }
1137
1138 /*------------------------------------------------------------------*/
1139 /*
1140  * Cleanup at exit...
1141  */
1142 static inline void __exit
1143 ppp_irnet_cleanup(void)
1144 {
1145   DENTER(MODULE_TRACE, "()\n");
1146
1147   /* De-allocate /dev/irnet minor in misc range */
1148   misc_deregister(&irnet_misc_device);
1149
1150   DEXIT(MODULE_TRACE, "\n");
1151 }
1152
1153 /*------------------------------------------------------------------*/
1154 /*
1155  * Module main entry point
1156  */
1157 static int __init
1158 irnet_init(void)
1159 {
1160   int err;
1161
1162   /* Initialise both parts... */
1163   err = irda_irnet_init();
1164   if(!err)
1165     err = ppp_irnet_init();
1166   return err;
1167 }
1168
1169 /*------------------------------------------------------------------*/
1170 /*
1171  * Module exit
1172  */
1173 static void __exit
1174 irnet_cleanup(void)
1175 {
1176   irda_irnet_cleanup();
1177   ppp_irnet_cleanup();
1178 }
1179
1180 /*------------------------------------------------------------------*/
1181 /*
1182  * Module magic
1183  */
1184 module_init(irnet_init);
1185 module_exit(irnet_cleanup);
1186 MODULE_AUTHOR("Jean Tourrilhes <jt@hpl.hp.com>");
1187 MODULE_DESCRIPTION("IrNET : Synchronous PPP over IrDA");
1188 MODULE_LICENSE("GPL");
1189 MODULE_ALIAS_CHARDEV(10, 187);