irnet_irda.c

linux-2.4.29操作系统的源码

       * ALLOW_SIMULT_CONNECT is undefined. ttp_connect should be 1.
       * 3) we are half way in irnet_disconnect_indication(), and it's a
       * nice race condition... Fortunately, we can detect that by checking
       * if tsap is still alive. On the other hand, we can't be in
       * irda_irnet_destroy() otherwise we would not have found this
       * socket in the hashbin.
       * Jean II */
      if((test_bit(0, &new->ttp_connect)) || (new->tsap != NULL))
	{
	  /* Don't mess this socket, somebody else in in charge... */
	  DERROR(IRDA_CB_ERROR, "Race condition detected, socket in use, abort connect...\n");
	  irnet_disconnect_server(server, skb);
	  return;
	}
    }

  /* So : at this point, we have a socket, and it is idle. Good ! */
  irnet_connect_socket(server, new, qos, max_sdu_size, max_header_size);

  /* Check size of received packet */
  if(skb->len > 0)
    {
#ifdef PASS_CONNECT_PACKETS
      DEBUG(IRDA_CB_INFO, "Passing connect packet to PPP.\n");
      /* Try to pass it to PPP */
      irnet_data_indication(new, new->tsap, skb);
#else /* PASS_CONNECT_PACKETS */
      DERROR(IRDA_CB_ERROR, "Dropping non empty packet.\n");
      kfree_skb(skb);	/* Note : will be optimised with other kfree... */
#endif /* PASS_CONNECT_PACKETS */
    }
  else
    kfree_skb(skb);

  DEXIT(IRDA_TCB_TRACE, "\n");
}


/********************** IRDA-IAS/LMP CALLBACKS **********************/
/*
 * These are the callbacks called by other layers of the IrDA stack,
 * mainly LMP for discovery and IAS for name queries.
 */

/*------------------------------------------------------------------*/
/*
 * Function irnet_getvalue_confirm (result, obj_id, value, priv)
 *
 *    Got answer from remote LM-IAS, just connect
 *
 * This is the reply to a IAS query we were doing to find the TSAP of
 * the device we want to connect to.
 * If we have found a valid TSAP, just initiate the TTP connection
 * on this TSAP.
 */
static void
irnet_getvalue_confirm(int	result,
		       __u16	obj_id, 
		       struct ias_value *value,
		       void *	priv)
{
  irnet_socket *	self = (irnet_socket *) priv;

  DENTER(IRDA_OCB_TRACE, "(self=0x%X)\n", (unsigned int) self);
  DASSERT(self != NULL, , IRDA_OCB_ERROR, "Self is NULL !!!\n");

  /* Check if already connected (via irnet_connect_socket())
   * or socket is closing down (via irda_irnet_destroy()) */
  if(! test_bit(0, &self->ttp_connect))
    {
      DERROR(IRDA_OCB_ERROR, "Socket no longer connecting. Ouch !\n");
      return;
    }

  /* We probably don't need to make any more queries */
  iriap_close(self->iriap);
  self->iriap = NULL;

  /* Post process the IAS reply */
  self->dtsap_sel = irnet_ias_to_tsap(self, result, value);

  /* If error, just go out */
  if(self->errno)
    {
      clear_bit(0, &self->ttp_connect);
      DERROR(IRDA_OCB_ERROR, "IAS connect failed ! (0x%X)\n", self->errno);
      return;
    }

  DEBUG(IRDA_OCB_INFO, "daddr = %08x, lsap = %d, starting IrTTP connection\n",
	self->daddr, self->dtsap_sel);

  /* Start up TTP - non blocking */
  irnet_connect_tsap(self);

  DEXIT(IRDA_OCB_TRACE, "\n");
}

/*------------------------------------------------------------------*/
/*
 * Function irnet_discovervalue_confirm (result, obj_id, value, priv)
 *
 *    Handle the TSAP discovery procedure state machine.
 *    Got answer from remote LM-IAS, try next device
 *
 * We are doing a  TSAP discovery procedure, and we got an answer to
 * a IAS query we were doing to find the TSAP on one of the address
 * in the discovery log.
 *
 * If we have found a valid TSAP for the first time, save it. If it's
 * not the first time we found one, complain.
 *
 * If we have more addresses in the log, just initiate a new query.
 * Note that those query may fail (see irnet_discover_daddr_and_lsap_sel())
 *
 * Otherwise, wrap up the procedure (cleanup), check if we have found
 * any device and connect to it.
 */
static void
irnet_discovervalue_confirm(int		result,
			    __u16	obj_id, 
			    struct ias_value *value,
			    void *	priv)
{
  irnet_socket *	self = (irnet_socket *) priv;
  __u8			dtsap_sel;		/* TSAP we are looking for */

  DENTER(IRDA_OCB_TRACE, "(self=0x%X)\n", (unsigned int) self);
  DASSERT(self != NULL, , IRDA_OCB_ERROR, "Self is NULL !!!\n");

  /* Check if already connected (via irnet_connect_socket())
   * or socket is closing down (via irda_irnet_destroy()) */
  if(! test_bit(0, &self->ttp_connect))
    {
      DERROR(IRDA_OCB_ERROR, "Socket no longer connecting. Ouch !\n");
      return;
    }

  /* Post process the IAS reply */
  dtsap_sel = irnet_ias_to_tsap(self, result, value);

  /* Have we got something ? */
  if(self->errno == 0)
    {
      /* We found the requested service */
      if(self->daddr != DEV_ADDR_ANY)
	{
	  DERROR(IRDA_OCB_ERROR, "More than one device in range supports IrNET...\n");
	}
      else
	{
	  /* First time we found that one, save it ! */
	  self->daddr = self->discoveries[self->disco_index].daddr;
	  self->dtsap_sel = dtsap_sel;
	}
    }

  /* If no failure */
  if((self->errno == -EADDRNOTAVAIL) || (self->errno == 0))
    {
      int	ret;

      /* Search the next node */
      ret = irnet_discover_next_daddr(self);
      if(!ret)
	{
	  /* In this case, the above request was non-blocking.
	   * We will return here after a while... */
	  return;
	}
      /* In this case, we have processed the last discovery item */
    }

  /* No more queries to be done (failure or last one) */

  /* We probably don't need to make any more queries */
  iriap_close(self->iriap);
  self->iriap = NULL;

  /* No more items : remove the log and signal termination */
  DEBUG(IRDA_OCB_INFO, "Cleaning up log (0x%X)\n",
	(unsigned int) self->discoveries);
  if(self->discoveries != NULL)
    {
      /* Cleanup our copy of the discovery log */
      kfree(self->discoveries);
      self->discoveries = NULL;
    }
  self->disco_number = -1;

  /* Check out what we found */
  if(self->daddr == DEV_ADDR_ANY)
    {
      self->daddr = DEV_ADDR_ANY;
      clear_bit(0, &self->ttp_connect);
      DEXIT(IRDA_OCB_TRACE, ": cannot discover IrNET in any device !!!\n");
      return;
    }

  /* We have a valid address - just connect */

  DEBUG(IRDA_OCB_INFO, "daddr = %08x, lsap = %d, starting IrTTP connection\n",
	self->daddr, self->dtsap_sel);

  /* Start up TTP - non blocking */
  irnet_connect_tsap(self);

  DEXIT(IRDA_OCB_TRACE, "\n");
}

#ifdef DISCOVERY_EVENTS
/*------------------------------------------------------------------*/
/*
 * Function irnet_discovery_indication (discovery)
 *
 *    Got a discovery indication from IrLMP, post an event
 *
 * Note : IrLMP take care of matching the hint mask for us, we only
 * check if it is a "new" node...
 *
 * As IrLMP filter on the IrLAN hint bit, we get both IrLAN and IrNET
 * nodes, so it's only at connection time that we will know if the
 * node support IrNET, IrLAN or both. The other solution is to check
 * in IAS the PNP ids and service name.
 * Note : even if a node support IrNET (or IrLAN), it's no guarantee
 * that we will be able to connect to it, the node might already be
 * busy...
 *
 * One last thing : in some case, this function will trigger duplicate
 * discovery events. On the other hand, we should catch all
 * discoveries properly (i.e. not miss one). Filtering duplicate here
 * is to messy, so we leave that to user space...
 */
static void
irnet_discovery_indication(discovery_t *	discovery,
			   DISCOVERY_MODE	mode,
			   void *		priv)
{
  irnet_socket *	self = &irnet_server.s;
	
  DENTER(IRDA_OCB_TRACE, "(self=0x%X)\n", (unsigned int) self);
  DASSERT(priv == &irnet_server, , IRDA_OCB_ERROR,
	  "Invalid instance (0x%X) !!!\n", (unsigned int) priv);

  /* Check if node is discovered is a new one or an old one.
   * We check when how long ago this node was discovered, with a
   * coarse timeout (we may miss some discovery events or be delayed).
   */
  if((jiffies - discovery->first_timestamp) >= (sysctl_discovery_timeout * HZ))
    {
      return;		/* Too old, not interesting -> goodbye */
    }

  DEBUG(IRDA_OCB_INFO, "Discovered new IrNET/IrLAN node %s...\n",
	discovery->nickname);

  /* Notify the control channel */
  irnet_post_event(NULL, IRNET_DISCOVER,
		   discovery->saddr, discovery->daddr, discovery->nickname);

  DEXIT(IRDA_OCB_TRACE, "\n");
}

/*------------------------------------------------------------------*/
/*
 * Function irnet_expiry_indication (expiry)
 *
 *    Got a expiry indication from IrLMP, post an event
 *
 * Note : IrLMP take care of matching the hint mask for us, we only
 * check if it is a "new" node...
 */
static void
irnet_expiry_indication(discovery_t *	expiry,
			DISCOVERY_MODE	mode,
			void *		priv)
{
  irnet_socket *	self = &irnet_server.s;
	
  DENTER(IRDA_OCB_TRACE, "(self=0x%X)\n", (unsigned int) self);
  DASSERT(priv == &irnet_server, , IRDA_OCB_ERROR,
	  "Invalid instance (0x%X) !!!\n", (unsigned int) priv);

  DEBUG(IRDA_OCB_INFO, "IrNET/IrLAN node %s expired...\n",
	expiry->nickname);

  /* Notify the control channel */
  irnet_post_event(NULL, IRNET_EXPIRE,
		   expiry->saddr, expiry->daddr, expiry->nickname);

  DEXIT(IRDA_OCB_TRACE, "\n");
}
#endif /* DISCOVERY_EVENTS */


/*********************** PROC ENTRY CALLBACKS ***********************/
/*
 * We create a instance in the /proc filesystem, and here we take care
 * of that...
 */

#ifdef CONFIG_PROC_FS
/*------------------------------------------------------------------*/
/*
 * Function irnet_proc_read (buf, start, offset, len, unused)
 *
 *    Give some info to the /proc file system
 */
static int
irnet_proc_read(char *	buf,
		char **	start,
		off_t	offset,
		int	len)
{
  irnet_socket *	self;
  char *		state;
  unsigned long		flags;
  int			i = 0;

  len = 0;
	
  /* Get the IrNET server information... */
  len += sprintf(buf+len, "IrNET server - ");
  len += sprintf(buf+len, "IrDA state: %s, ",
		 (irnet_server.running ? "running" : "dead"));
  len += sprintf(buf+len, "stsap_sel: %02x, ", irnet_server.s.stsap_sel);
  len += sprintf(buf+len, "dtsap_sel: %02x\n", irnet_server.s.dtsap_sel);

  /* Do we need to continue ? */
  if(!irnet_server.running)
    return len;

  /* Protect access to the instance list */
  spin_lock_irqsave(&irnet_server.spinlock, flags);

  /* Get the sockets one by one... */
  self = (irnet_socket *) hashbin_get_first(irnet_server.list);
  while(self != NULL)
    {
      /* Start printing info about the socket. */
      len += sprintf(buf+len, "\nIrNET socket %d - ", i++);

      /* First, get the requested configuration */
      len += sprintf(buf+len, "Requested IrDA name: \"%s\", ", self->rname);
      len += sprintf(buf+len, "daddr: %08x, ", self->rdaddr);
      len += sprintf(buf+len, "saddr: %08x\n", self->rsaddr);

      /* Second, get all the PPP info */
      len += sprintf(buf+len, "	PPP state: %s",
		 (self->ppp_open ? "registered" : "unregistered"));
      if(self->ppp_open)
	{
	  len += sprintf(buf+len, ", unit: ppp%d",
			 ppp_unit_number(&self->chan));
	  len += sprintf(buf+len, ", channel: %d",
			 ppp_channel_index(&self->chan));
	  len += sprintf(buf+len, ", mru: %d",
			 self->mru);
	  /* Maybe add self->flags ? Later... */
	}

      /* Then, get all the IrDA specific info... */
      if(self->ttp_open)
	state = "connected";
      else
	if(self->tsap != NULL)
	  state = "connecting";
	else
	  if(self->iriap != NULL)
	    state = "searching";
	  else
	    if(self->ttp_connect)
	      state = "weird";
	    else
	      state = "idle";
      len += sprintf(buf+len, "\n	IrDA state: %s, ", state);
      len += sprintf(buf+len, "daddr: %08x, ", self->daddr);
      len += sprintf(buf+len, "stsap_sel: %02x, ", self->stsap_sel);
      len += sprintf(buf+len, "dtsap_sel: %02x\n", self->dtsap_sel);

      /* Next socket, please... */
      self = (irnet_socket *) hashbin_get_next(irnet_server.list);
    }

  /* Spin lock end */
  spin_unlock_irqrestore(&irnet_server.spinlock, flags);

  return len;
}
#endif /* PROC_FS */


/********************** CONFIGURATION/CLEANUP **********************/
/*
 * Initialisation and teardown of the IrDA part, called at module
 * insertion and removal...
 */

/*------------------------------------------------------------------*/
/*
 * Prepare the IrNET layer for operation...
 */
int
irda_irnet_init(void)
{
  int		err = 0;

  DENTER(MODULE_TRACE, "()\n");

  /* Pure paranoia - should be redundant */
  memset(&irnet_server, 0, sizeof(struct irnet_root));

  /* Setup start of irnet instance list */
  irnet_server.list = hashbin_new(HB_NOLOCK); 
  DABORT(irnet_server.list == NULL, -ENOMEM,
	 MODULE_ERROR, "Can't allocate hashbin!\n");
  /* Init spinlock for instance list */
  spin_lock_init(&irnet_server.spinlock);

  /* Initialise control channel */
  init_waitqueue_head(&irnet_events.rwait);
  irnet_events.index = 0;
  /* Init spinlock for event logging */
  spin_lock_init(&irnet_events.spinlock);

#ifdef CONFIG_PROC_FS
  /* Add a /proc file for irnet infos */
  create_proc_info_entry("irnet", 0, proc_irda, irnet_proc_read);
#endif /* CONFIG_PROC_FS */

  /* Setup the IrNET server */
  err = irnet_setup_server();

  if(!err)
    /* We are no longer functional... */
    irnet_server.running = 1;

  DEXIT(MODULE_TRACE, "\n");
  return err;
}

/*------------------------------------------------------------------*/
/*
 * Cleanup at exit...
 */
void
irda_irnet_cleanup(void)
{
  DENTER(MODULE_TRACE, "()\n");

  /* We are no longer there... */
  irnet_server.running = 0;

#ifdef CONFIG_PROC_FS
  /* Remove our /proc file */
  remove_proc_entry("irnet", proc_irda);
#endif /* CONFIG_PROC_FS */

  /* Remove our IrNET server from existence */
  irnet_destroy_server();

  /* Remove all instances of IrNET socket still present */
  hashbin_delete(irnet_server.list, (FREE_FUNC) irda_irnet_destroy);

  DEXIT(MODULE_TRACE, "\n");
}