irnet_ppp.c

linux-2.4.29操作系统的源码

    default:
      sprintf(event, "Bug\n");
    }
  /* Increment our event index */
  ap->event_index = (ap->event_index + 1) % IRNET_MAX_EVENTS;

  DEBUG(CTRL_INFO, "Event is :%s", event);

  /* Copy it to the user */
  if(copy_to_user(buf, event, strlen(event)))
    {
      DERROR(CTRL_ERROR, "Invalid user space pointer.\n");
      return -EFAULT;
    }

  DEXIT(CTRL_TRACE, "\n");
  return(strlen(event));
}

/*------------------------------------------------------------------*/
/*
 * Poll : called when someone do a select on /dev/irnet.
 * Just check if there are new events...
 */
static inline unsigned int
irnet_ctrl_poll(irnet_socket *	ap,
		struct file *	file,
		poll_table *	wait)
{
  unsigned int mask;

  DENTER(CTRL_TRACE, "(ap=0x%X)\n", (unsigned int) ap);

  poll_wait(file, &irnet_events.rwait, wait);
  mask = POLLOUT | POLLWRNORM;
  /* If there is unread events */
  if(ap->event_index != irnet_events.index)
    mask |= POLLIN | POLLRDNORM;
#ifdef INITIAL_DISCOVERY
  if(ap->disco_number != -1)
    mask |= POLLIN | POLLRDNORM;
#endif /* INITIAL_DISCOVERY */

  DEXIT(CTRL_TRACE, " - mask=0x%X\n", mask);
  return mask;
}


/*********************** FILESYSTEM CALLBACKS ***********************/
/*
 * Implement the usual open, read, write functions that will be called
 * by the file system when some action is performed on /dev/irnet.
 * Most of those actions will in fact be performed by "pppd" or
 * the control channel, we just act as a redirector...
 */

/*------------------------------------------------------------------*/
/*
 * Open : when somebody open /dev/irnet
 * We basically create a new instance of irnet and initialise it.
 */
static int
dev_irnet_open(struct inode *	inode,
	       struct file *	file)
{
  struct irnet_socket *	ap;
  int			err;

  DENTER(FS_TRACE, "(file=0x%X)\n", (unsigned int) file);

#ifdef SECURE_DEVIRNET
  /* This could (should?) be enforced by the permissions on /dev/irnet. */
  if(!capable(CAP_NET_ADMIN))
    return -EPERM;
#endif /* SECURE_DEVIRNET */

  /* Allocate a private structure for this IrNET instance */
  ap = kmalloc(sizeof(*ap), GFP_KERNEL);
  DABORT(ap == NULL, -ENOMEM, FS_ERROR, "Can't allocate struct irnet...\n");

  MOD_INC_USE_COUNT;

  /* initialize the irnet structure */
  memset(ap, 0, sizeof(*ap));
  ap->file = file;

  /* PPP channel setup */
  ap->ppp_open = 0;
  ap->chan.private = ap;
  ap->chan.ops = &irnet_ppp_ops;
  ap->chan.mtu = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
  ap->chan.hdrlen = 2 + TTP_MAX_HEADER;		/* for A/C + Max IrDA hdr */
  /* PPP parameters */
  ap->mru = (2048 - TTP_MAX_HEADER - 2 - PPP_HDRLEN);
  ap->xaccm[0] = ~0U;
  ap->xaccm[3] = 0x60000000U;
  ap->raccm = ~0U;

  /* Setup the IrDA part... */
  err = irda_irnet_create(ap);
  if(err)
    {
      DERROR(FS_ERROR, "Can't setup IrDA link...\n");
      kfree(ap);
      MOD_DEC_USE_COUNT;
      return err;
    }

  /* For the control channel */
  ap->event_index = irnet_events.index;	/* Cancel all past events */

  /* Put our stuff where we will be able to find it later */
  file->private_data = ap;

  DEXIT(FS_TRACE, " - ap=0x%X\n", (unsigned int) ap);
  return 0;
}


/*------------------------------------------------------------------*/
/*
 * Close : when somebody close /dev/irnet
 * Destroy the instance of /dev/irnet
 */
static int
dev_irnet_close(struct inode *	inode,
		struct file *	file)
{
  irnet_socket *	ap = (struct irnet_socket *) file->private_data;

  DENTER(FS_TRACE, "(file=0x%X, ap=0x%X)\n",
	 (unsigned int) file, (unsigned int) ap);
  DABORT(ap == NULL, 0, FS_ERROR, "ap is NULL !!!\n");

  /* Detach ourselves */
  file->private_data = NULL;

  /* Close IrDA stuff */
  irda_irnet_destroy(ap);

  /* Disconnect from the generic PPP layer if not already done */
  if(ap->ppp_open)
    {
      DERROR(FS_ERROR, "Channel still registered - deregistering !\n");
      ppp_unregister_channel(&ap->chan);
      ap->ppp_open = 0;
    }

  kfree(ap);
  MOD_DEC_USE_COUNT;

  DEXIT(FS_TRACE, "\n");
  return 0;
}

/*------------------------------------------------------------------*/
/*
 * Write does nothing.
 * (we receive packet from ppp_generic through ppp_irnet_send())
 */
static ssize_t
dev_irnet_write(struct file *	file,
		const char *	buf,
		size_t		count,
		loff_t *	ppos)
{
  irnet_socket *	ap = (struct irnet_socket *) file->private_data;

  DPASS(FS_TRACE, "(file=0x%X, ap=0x%X, count=%d)\n",
	(unsigned int) file, (unsigned int) ap, count);
  DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");

  /* If we are connected to ppp_generic, let it handle the job */
  if(ap->ppp_open)
    return -EAGAIN;
  else
    return irnet_ctrl_write(ap, buf, count);
}

/*------------------------------------------------------------------*/
/*
 * Read doesn't do much either.
 * (pppd poll us, but ultimately reads through /dev/ppp)
 */
static ssize_t
dev_irnet_read(struct file *	file,
	       char *		buf,
	       size_t		count,
	       loff_t *		ppos)
{
  irnet_socket *	ap = (struct irnet_socket *) file->private_data;

  DPASS(FS_TRACE, "(file=0x%X, ap=0x%X, count=%d)\n",
	(unsigned int) file, (unsigned int) ap, count);
  DABORT(ap == NULL, -ENXIO, FS_ERROR, "ap is NULL !!!\n");

  /* If we are connected to ppp_generic, let it handle the job */
  if(ap->ppp_open)
    return -EAGAIN;
  else
    return irnet_ctrl_read(ap, file, buf, count);
}

/*------------------------------------------------------------------*/
/*
 * Poll : called when someone do a select on /dev/irnet
 */
static unsigned int
dev_irnet_poll(struct file *	file,
	       poll_table *	wait)
{
  irnet_socket *	ap = (struct irnet_socket *) file->private_data;
  unsigned int		mask;

  DENTER(FS_TRACE, "(file=0x%X, ap=0x%X)\n",
	 (unsigned int) file, (unsigned int) ap);

  mask = POLLOUT | POLLWRNORM;
  DABORT(ap == NULL, mask, FS_ERROR, "ap is NULL !!!\n");

  /* If we are connected to ppp_generic, let it handle the job */
  if(!ap->ppp_open)
    mask |= irnet_ctrl_poll(ap, file, wait);

  DEXIT(FS_TRACE, " - mask=0x%X\n", mask);
  return(mask);
}

/*------------------------------------------------------------------*/
/*
 * IOCtl : Called when someone does some ioctls on /dev/irnet
 * This is the way pppd configure us and control us while the PPP
 * instance is active.
 */
static int
dev_irnet_ioctl(struct inode *	inode,
		struct file *	file,
		unsigned int	cmd,
		unsigned long	arg)
{
  irnet_socket *	ap = (struct irnet_socket *) file->private_data;
  int			err;
  int			val;

  DENTER(FS_TRACE, "(file=0x%X, ap=0x%X, cmd=0x%X)\n",
	 (unsigned int) file, (unsigned int) ap, cmd);

  /* Basic checks... */
  DASSERT(ap != NULL, -ENXIO, PPP_ERROR, "ap is NULL...\n");
#ifdef SECURE_DEVIRNET
  if(!capable(CAP_NET_ADMIN))
    return -EPERM;
#endif /* SECURE_DEVIRNET */

  err = -EFAULT;
  switch(cmd)
    {
      /* Set discipline (should be N_SYNC_PPP or N_TTY) */
    case TIOCSETD:
      if(get_user(val, (int *) arg))
	break;
      if((val == N_SYNC_PPP) || (val == N_PPP))
	{
	  DEBUG(FS_INFO, "Entering PPP discipline.\n");
	  /* PPP channel setup (ap->chan in configued in dev_irnet_open())*/
	  err = ppp_register_channel(&ap->chan);
	  if(err == 0)
	    {
	      /* Our ppp side is active */
	      ap->ppp_open = 1;

	      DEBUG(FS_INFO, "Trying to establish a connection.\n");
	      /* Setup the IrDA link now - may fail... */
	      irda_irnet_connect(ap);
	    }
	  else
	    DERROR(FS_ERROR, "Can't setup PPP channel...\n");
	}
      else
	{
	  /* In theory, should be N_TTY */
	  DEBUG(FS_INFO, "Exiting PPP discipline.\n");
	  /* Disconnect from the generic PPP layer */
	  if(ap->ppp_open)
	    ppp_unregister_channel(&ap->chan);
	  else
	    DERROR(FS_ERROR, "Channel not registered !\n");
	  ap->ppp_open = 0;
	  err = 0;
	}
      break;

      /* Query PPP channel and unit number */
    case PPPIOCGCHAN:
      if(!ap->ppp_open)
	break;
      if(put_user(ppp_channel_index(&ap->chan), (int *) arg))
	break;
      DEBUG(FS_INFO, "Query channel.\n");
      err = 0;
      break;
    case PPPIOCGUNIT:
      if(!ap->ppp_open)
	break;
      if(put_user(ppp_unit_number(&ap->chan), (int *) arg))
	break;
      DEBUG(FS_INFO, "Query unit number.\n");
      err = 0;
      break;

      /* All these ioctls can be passed both directly and from ppp_generic,
       * so we just deal with them in one place...
       */
    case PPPIOCGFLAGS:
    case PPPIOCSFLAGS:
    case PPPIOCGASYNCMAP:
    case PPPIOCSASYNCMAP:
    case PPPIOCGRASYNCMAP:
    case PPPIOCSRASYNCMAP:
    case PPPIOCGXASYNCMAP:
    case PPPIOCSXASYNCMAP:
    case PPPIOCGMRU:
    case PPPIOCSMRU:
      DEBUG(FS_INFO, "Standard PPP ioctl.\n");
      if(!capable(CAP_NET_ADMIN))
	err = -EPERM;
      else
	err = ppp_irnet_ioctl(&ap->chan, cmd, arg);
      break;

      /* TTY IOCTLs : Pretend that we are a tty, to keep pppd happy */
      /* Get termios */
    case TCGETS:
      DEBUG(FS_INFO, "Get termios.\n");
      if(kernel_termios_to_user_termios((struct termios *)arg, &ap->termios))
	break;
      err = 0;
      break;
      /* Set termios */
    case TCSETSF:
      DEBUG(FS_INFO, "Set termios.\n");
      if(user_termios_to_kernel_termios(&ap->termios, (struct termios *) arg))
	break;
      err = 0;
      break;

      /* Set DTR/RTS */
    case TIOCMBIS: 
    case TIOCMBIC:
      /* Set exclusive/non-exclusive mode */
    case TIOCEXCL:
    case TIOCNXCL:
      DEBUG(FS_INFO, "TTY compatibility.\n");
      err = 0;
      break;

    case TCGETA:
      DEBUG(FS_INFO, "TCGETA\n");
      break;

    case TCFLSH:
      DEBUG(FS_INFO, "TCFLSH\n");
      /* Note : this will flush buffers in PPP, so it *must* be done
       * We should also worry that we don't accept junk here and that
       * we get rid of our own buffers */
#ifdef FLUSH_TO_PPP
      ppp_output_wakeup(&ap->chan);