irnet_irda.c

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  /* Unregister with LM-IAS */
  if(self->iriap) 
    iriap_close(self->iriap);

  /* Prevent higher layer from accessing IrTTP */
  self->ttp_open = 0;

  /* Close our IrTTP connection */
  if(self->tsap)
    {
      DEBUG(IRDA_SOCK_INFO, "Closing our TTP connection.\n");
      irttp_disconnect_request(self->tsap, NULL, P_NORMAL);
      irttp_close_tsap(self->tsap);
      self->tsap = NULL;
      /* Note : as the disconnect comes from ppp_generic, the unit number
       * doesn't exist anymore when we post the event, so we need to pass
       * NULL as the first arg... */
      irnet_post_event(NULL, IRNET_DISCONNECT_TO, self->daddr, self->rname);
    }
  self->stsap_sel = 0;

  DEXIT(IRDA_SOCK_TRACE, "\n");
  return;
}


/************************** SERVER SOCKET **************************/
/*
 * The IrNET service is composed of one server socket and a variable
 * number of regular IrNET sockets. The server socket is supposed to
 * handle incomming connections and redirect them to one IrNET sockets.
 * It's a superset of the regular IrNET socket, but has a very distinct
 * behaviour...
 */

/*------------------------------------------------------------------*/
/*
 * Function irnet_daddr_to_dname (self)
 *
 *    Convert an IrDA address to a IrDA nickname
 *
 * It basically look into the discovery log until there is a match.
 */
static inline int
irnet_daddr_to_dname(irnet_socket *	self)
{
  struct irda_device_info *discoveries;	/* Copy of the discovery log */
  int	number;			/* Number of nodes in the log */
  int	i;

  DENTER(IRDA_SERV_TRACE, "(self=0x%X)\n", (unsigned int) self);

  /* Ask lmp for the current discovery log */
  discoveries = irlmp_get_discoveries(&number, 0xffff);
  /* Check if the we got some results */
  if (discoveries == NULL)
    DRETURN(-ENETUNREACH, IRDA_SERV_INFO, "Cachelog empty...\n");

  /* Now, check all discovered devices (if any) */
  for(i = 0; i < number; i++)
    {
      /* Does the name match ? */
      if(discoveries[i].daddr == self->daddr)
	{
	  /* Yes !!! Get it.. */
	  strncpy(self->rname, discoveries[i].info, NICKNAME_MAX_LEN);
	  self->rname[NICKNAME_MAX_LEN + 1] = '\0';
	  DEBUG(IRDA_SERV_INFO, "Device 0x%08x is in fact ``%s''.\n",
		self->daddr, self->rname);
	  kfree(discoveries);
	  DEXIT(IRDA_SERV_TRACE, "\n");
	  return 0;
	}
    }
  /* No luck ! */
  DEXIT(IRDA_SERV_INFO, ": cannot discover device 0x%08x !!!\n", self->daddr);
  kfree(discoveries);
  return(-EADDRNOTAVAIL);
}

/*------------------------------------------------------------------*/
/*
 * Function irda_find_socket (self)
 *
 *    Find the correct IrNET socket
 *
 * Look into the list of IrNET sockets and finds one with the right
 * properties...
 */
static inline irnet_socket *
irnet_find_socket(irnet_socket *	self)
{
  irnet_socket *	new = (irnet_socket *) NULL;
  unsigned long		flags;
  int			err;

  DENTER(IRDA_SERV_TRACE, "(self=0x%X)\n", (unsigned int) self);

  /* Get the address of the requester */
  self->daddr = irttp_get_daddr(self->tsap);

  /* Try to get the IrDA nickname of the requester */
  err = irnet_daddr_to_dname(self);

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

  /* So now, try to get an socket having specifically
   * requested that nickname */
  if(err == 0)
    {
      new = (irnet_socket *) hashbin_find(irnet_server.list,
					  0, self->rname);
      if(new)
	DEBUG(IRDA_SERV_INFO, "Socket 0x%X matches rname ``%s''.\n",
	      (unsigned int) new, new->rname);
    }

  /* If no name matches, try to find an socket by the destination address */
  /* It can be either the requested destination address (set via the
   * control channel), or the current destination address if the
   * socket is in the middle of a connection request */
  if(new == (irnet_socket *) NULL)
    {
      new = (irnet_socket *) hashbin_get_first(irnet_server.list);
      while(new !=(irnet_socket *) NULL)
	{
	  /* Does it have the same address ? */
	  if((new->raddr == self->daddr) || (new->daddr == self->daddr))
	    {
	      /* Yes !!! Get it.. */
	      DEBUG(IRDA_SERV_INFO, "Socket 0x%X matches daddr %#08x.\n",
		    (unsigned int) new, self->daddr);
	      break;
	    }
	  new = (irnet_socket *) hashbin_get_next(irnet_server.list);
	}
    }

  /* If we don't have any socket, get the first unconnected socket */
  if(new == (irnet_socket *) NULL)
    {
      new = (irnet_socket *) hashbin_get_first(irnet_server.list);
      while(new !=(irnet_socket *) NULL)
	{
	  /* Is it available ? */
	  if(!(new->ttp_open) && (new->raddr == DEV_ADDR_ANY) &&
	     (new->rname[0] == '\0') && (new->ppp_open))
	    {
	      /* Yes !!! Get it.. */
	      DEBUG(IRDA_SERV_INFO, "Socket 0x%X is free.\n",
		    (unsigned int) new);
	      break;
	    }
	  new = (irnet_socket *) hashbin_get_next(irnet_server.list);
	}
    }

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

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

/*------------------------------------------------------------------*/
/*
 * Function irda_connect_socket (self)
 *
 *    Connect an incomming connection to the socket
 *
 */
static inline int
irnet_connect_socket(irnet_socket *	self,
		     irnet_socket *	new,
		     struct qos_info *	qos,
		     __u32		max_sdu_size,
		     __u8		max_header_size)
{
  DENTER(IRDA_SERV_TRACE, "(self=0x%X, new=0x%X)\n",
	 (unsigned int) self, (unsigned int) new);

  /* Now attach up the new socket */
  new->tsap = irttp_dup(self->tsap, new);
  DABORT(new->tsap == NULL, -1, IRDA_SERV_ERROR, "dup failed!\n");

  /* Set up all the relevant parameters on the new socket */
  new->stsap_sel = new->tsap->stsap_sel;
  new->dtsap_sel = new->tsap->dtsap_sel;
  new->saddr = irttp_get_saddr(new->tsap);
  new->daddr = irttp_get_daddr(new->tsap);

  new->max_header_size = max_header_size;
  new->max_sdu_size_tx = max_sdu_size;
  new->max_data_size   = max_sdu_size;
#ifdef STREAM_COMPAT
  /* If we want to receive "stream sockets" */
  if(max_sdu_size == 0)
    new->max_data_size = irttp_get_max_seg_size(new->tsap);
#endif STREAM_COMPAT

  /* Clean up the original one to keep it in listen state */
  self->tsap->dtsap_sel = self->tsap->lsap->dlsap_sel = LSAP_ANY;
  self->tsap->lsap->lsap_state = LSAP_DISCONNECTED;

  /* Send a connection response on the new socket */
  irttp_connect_response(new->tsap, new->max_sdu_size_rx, NULL);

  /* Allow PPP to send its junk over the new socket... */
  new->ttp_open = 1;
#ifdef CONNECT_INDIC_KICK
  /* As currently we don't packets in ppp_irnet_send(), this is not needed...
   * Also, not doing it give IrDA a chance to finish the setup properly
   * before beeing swamped with packets... */
  ppp_output_wakeup(&new->chan);
#endif CONNECT_INDIC_KICK

  /* Notify the control channel */
  irnet_post_event(new, IRNET_CONNECT_FROM, new->daddr, self->rname);

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

/*------------------------------------------------------------------*/
/*
 * Function irda_disconnect_server (self)
 *
 *    Cleanup the server socket when the incomming connection abort
 *
 */
static inline void
irnet_disconnect_server(irnet_socket *	self,
			struct sk_buff *skb)
{
  DENTER(IRDA_SERV_TRACE, "(self=0x%X)\n", (unsigned int) self);

  /* Put the received packet in the black hole */
  kfree_skb(skb);

#ifdef FAIL_SEND_DISCONNECT
  /* Tell the other party we don't want to be connected */
  /* Hum... Is it the right thing to do ? And do we need to send
   * a connect response before ? It looks ok without this... */
  irttp_disconnect_request(self->tsap, NULL, P_NORMAL);
#endif FAIL_SEND_DISCONNECT

  /* Clean up the server to keep it in listen state */
  self->tsap->dtsap_sel = self->tsap->lsap->dlsap_sel = LSAP_ANY;
  self->tsap->lsap->lsap_state = LSAP_DISCONNECTED;

  /* Notify the control channel */
  irnet_post_event(NULL, IRNET_REQUEST_FROM, self->daddr, self->rname);

  DEXIT(IRDA_SERV_TRACE, "\n");
  return;
}

/*------------------------------------------------------------------*/
/*
 * Function irda_setup_server (self)
 *
 *    Create a IrTTP server and set it up...
 *
 * Register the IrLAN hint bit, create a IrTTP instance for us,
 * set all the IrTTP callbacks and create an IrIAS entry...
 */
static inline int
irnet_setup_server(void)
{
  __u16		hints;

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

  /* Initialise the regular socket part of the server */
  irda_irnet_create(&irnet_server.s);

  /* Open a local TSAP (an IrTTP instance) for the server */
  irnet_open_tsap(&irnet_server.s);

  /* PPP part setup */
  irnet_server.s.ppp_open = 0;
  irnet_server.s.chan.private = NULL;
  irnet_server.s.file = NULL;

  /* Get the hint bit corresponding to IrLAN */
  /* Note : we overload the IrLAN hint bit. As it is only a "hint", and as
   * we provide roughly the same functionality as IrLAN, this is ok.
   * In fact, the situation is similar as JetSend overloading the Obex hint
   */
  hints = irlmp_service_to_hint(S_LAN);

#ifdef ADVERTISE_HINT
  /* Register with IrLMP as a service (advertise our hint bit) */
  irnet_server.skey = irlmp_register_service(hints);
#endif ADVERTISE_HINT

  /* Register with LM-IAS (so that people can connect to us) */
  irnet_server.ias_obj = irias_new_object(IRNET_SERVICE_NAME, jiffies);
  irias_add_integer_attrib(irnet_server.ias_obj, IRNET_IAS_VALUE, 
			   irnet_server.s.stsap_sel, IAS_KERNEL_ATTR);
  irias_insert_object(irnet_server.ias_obj);

#ifdef DISCOVERY_EVENTS
  /* Tell IrLMP we want to be notified of newly discovered nodes */
  irlmp_update_client(irnet_server.s.ckey, hints,
		      irnet_discovery_indication, irnet_expiry_indication,
		      (void *) &irnet_server.s);
#endif

  DEXIT(IRDA_SERV_TRACE, " - self=0x%X\n", (unsigned int) &irnet_server.s);
  return 0;
}

/*------------------------------------------------------------------*/
/*
 * Function irda_destroy_server (self)
 *
 *    Destroy the IrTTP server...
 *
 * Reverse of the previous function...
 */
static inline void
irnet_destroy_server(void)
{
  DENTER(IRDA_SERV_TRACE, "()\n");

#ifdef ADVERTISE_HINT
  /* Unregister with IrLMP */
  irlmp_unregister_service(irnet_server.skey);
#endif ADVERTISE_HINT

  /* Unregister with LM-IAS */
  if(irnet_server.ias_obj)
    irias_delete_object(irnet_server.ias_obj);

  /* Cleanup the socket part */
  irda_irnet_destroy(&irnet_server.s);

  DEXIT(IRDA_SERV_TRACE, "\n");
  return;
}


/************************ IRDA-TTP CALLBACKS ************************/
/*
 * When we create a IrTTP instance, we pass to it a set of callbacks
 * that IrTTP will call in case of various events.
 * We take care of those events here.
 */

/*------------------------------------------------------------------*/
/*
 * Function irnet_data_indication (instance, sap, skb)
 *
 *    Received some data from TinyTP. Just queue it on the receive queue
 *
 */
static int
irnet_data_indication(void *	instance,
		      void *	sap,
		      struct sk_buff *skb)
{
  irnet_socket *	ap = (irnet_socket *) instance;
  unsigned char *	p;
  int			code = 0;

  DENTER(IRDA_TCB_TRACE, "(self/ap=0x%X, skb=0x%X)\n",
	 (unsigned int) ap,(unsigned int) skb);
  DASSERT(skb != NULL, 0, IRDA_CB_ERROR, "skb is NULL !!!\n");

  /* Check is ppp is ready to receive our packet */
  if(!ap->ppp_open)
    {
      DERROR(IRDA_CB_ERROR, "PPP not ready, dropping packet...\n");
      /* When we return error, TTP will need to requeue the skb and
       * will stop the sender. IrTTP will stall until we send it a
       * flow control request... */
      return -ENOMEM;
    }

  /* strip address/control field if present */
  p = skb->data;
  if((p[0] == PPP_ALLSTATIONS) && (p[1] == PPP_UI))
    {
      /* chop off address/control */
      if(skb->len < 3)
	goto err_exit;
      p = skb_pull(skb, 2);
    }

  /* decompress protocol field if compressed */
  if(p[0] & 1)
    {
      /* protocol is compressed */
      skb_push(skb, 1)[0] = 0;
    }
  else
    if(skb->len < 2)
      goto err_exit;

  /* pass to generic ppp layer */
  /* Note : how do I know if ppp can accept or not the packet ? This is
   * essential if I want to manage flow control smoothly... */
  ppp_input(&ap->chan, skb);

  DEXIT(IRDA_TCB_TRACE, "\n");
  return 0;

 err_exit:
  DERROR(IRDA_CB_ERROR, "Packet too small, dropping...\n");
  kfree_skb(skb);
  ppp_input_error(&ap->chan, code);
  return 0;	/* Don't return an error code, only for flow control... */
}

/*------------------------------------------------------------------*/
/*
 * Function irnet_disconnect_indication (instance, sap, reason, skb)
 *
 *    Connection has been closed. Chech reason to find out why
 *
 * Note : there are many cases where we come here :
 *	o attempted to connect, timeout
 *	o connected, link is broken, LAP has timeout
 *	o connected, other side close the link
 *	o connection request on the server no handled
 */
static void
irnet_disconnect_indication(void *	instance,
			    void *	sap, 
			    LM_REASON	reason,
			    struct sk_buff *skb)
{
  irnet_socket *	self = (irnet_socket *) instance;

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

  /* If we were active, notify the control channel */
  if(self->ttp_open)
    irnet_post_event(self, IRNET_DISCONNECT_FROM, self->daddr, self->rname);
  else
    /* If we were trying to connect, notify the control channel */
    if((self->tsap) && (self != &irnet_server.s))
      irnet_post_event(self, IRNET_NOANSWER_FROM, self->daddr, self->rname);

  /* Prevent higher layer from accessing IrTTP */
  self->ttp_open = 0;

  /* Close our IrTTP connection */
  if((self->tsap) && (self != &irnet_server.s))
    {
      DEBUG(IRDA_CB_INFO, "Closing our TTP connection.\n");
      irttp_disconnect_request(self->tsap, NULL, P_NORMAL);
      irttp_close_tsap(self->tsap);
      self->tsap = NULL;

      /* Flush (drain) ppp_generic Tx queue (most often we have blocked it) */
      if(self->ppp_open)
	ppp_output_wakeup(&self->chan);
    }
  /* Cleanup the socket in case we want to reconnect */
  self->stsap_sel = 0;
  self->daddr = DEV_ADDR_ANY;
  self->tx_flow = FLOW_START;

  /* Note : what should we say to ppp ?
   * It seem the ppp_generic and pppd are happy that way and will eventually
   * timeout gracefully, so don't bother them... */

  DEXIT(IRDA_TCB_TRACE, "\n");
}

/*------------------------------------------------------------------*/
/*
 * Function irnet_connect_confirm (instance, sap, qos, max_sdu_size, skb)
 *
 *    Connections has been confirmed by the remote device
 *
 */
static void
irnet_connect_confirm(void *	instance,
		      void *	sap, 
		      struct qos_info *qos,
		      __u32	max_sdu_size,
		      __u8	max_header_size, 
		      struct sk_buff *skb)
{
  irnet_socket *	self = (irnet_socket *) instance;

  DENTER(IRDA_TCB_TRACE, "(self=0x%X)\n", (unsigned int) self);