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irnet_ppp.c
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1 /*
2  * IrNET protocol module : Synchronous PPP over an IrDA socket.
3  *
4  * Jean II - HPL `00 - <[email protected]>
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 {
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  {
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 {
188 
189  /* Ask IrLMP for the current discovery log */
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 {
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;
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;
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;
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;
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 {
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 <[email protected]>");
1187 MODULE_DESCRIPTION("IrNET : Synchronous PPP over IrDA");
1188 MODULE_LICENSE("GPL");
1189 MODULE_ALIAS_CHARDEV(10, 187);