irnet_irda.c

linux-2.4.29操作系统的源码

/*------------------------------------------------------------------*/
/*
 * Create a IrNET instance : just initialise some parameters...
 */
int
irda_irnet_create(irnet_socket *	self)
{
  DENTER(IRDA_SOCK_TRACE, "(self=0x%X)\n", (unsigned int) self);

  self->magic = IRNET_MAGIC;	/* Paranoia */

  self->ttp_open = 0;		/* Prevent higher layer from accessing IrTTP */
  self->ttp_connect = 0;	/* Not connecting yet */
  self->rname[0] = '\0';	/* May be set via control channel */
  self->rdaddr = DEV_ADDR_ANY;	/* May be set via control channel */
  self->rsaddr = DEV_ADDR_ANY;	/* May be set via control channel */
  self->daddr = DEV_ADDR_ANY;	/* Until we get connected */
  self->saddr = DEV_ADDR_ANY;	/* Until we get connected */
  self->max_sdu_size_rx = TTP_SAR_UNBOUND;

  /* Register as a client with IrLMP */
  self->ckey = irlmp_register_client(0, NULL, NULL, NULL);
#ifdef DISCOVERY_NOMASK
  self->mask = 0xffff;		/* For W2k compatibility */
#else /* DISCOVERY_NOMASK */
  self->mask = irlmp_service_to_hint(S_LAN);
#endif /* DISCOVERY_NOMASK */
  self->tx_flow = FLOW_START;	/* Flow control from IrTTP */

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

/*------------------------------------------------------------------*/
/*
 * Connect to the other side :
 *	o convert device name to an address
 *	o find the socket number (dlsap)
 *	o Establish the connection
 *
 * Note : We no longer mimic af_irda. The IAS query for finding the TSAP
 * is done asynchronously, like the TTP connection. This allow us to
 * call this function from any context (not only process).
 * The downside is that following what's happening in there is tricky
 * because it involve various functions all over the place...
 */
int
irda_irnet_connect(irnet_socket *	self)
{
  int		err;

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

  /* Check if we are already trying to connect.
   * Because irda_irnet_connect() can be called directly by pppd plus
   * packet retries in ppp_generic and connect may take time, plus we may
   * race with irnet_connect_indication(), we need to be careful there... */
  if(test_and_set_bit(0, &self->ttp_connect))
    DRETURN(-EBUSY, IRDA_SOCK_INFO, "Already connecting...\n");
  if((self->iriap != NULL) || (self->tsap != NULL))
    DERROR(IRDA_SOCK_ERROR, "Socket not cleaned up...\n");

  /* Insert ourselves in the hashbin so that the IrNET server can find us.
   * Notes : 4th arg is string of 32 char max and must be null terminated
   *	     When 4th arg is used (string), 3rd arg isn't (int)
   *	     Can't re-insert (MUST remove first) so check for that... */
  if((irnet_server.running) && (self->q.q_next == NULL))
    {
      unsigned long		flags;
      spin_lock_irqsave(&irnet_server.spinlock, flags);
      hashbin_insert(irnet_server.list, (irda_queue_t *) self, 0, self->rname);
      spin_unlock_irqrestore(&irnet_server.spinlock, flags);
      DEBUG(IRDA_SOCK_INFO, "Inserted ``%s'' in hashbin...\n", self->rname);
    }

  /* If we don't have anything (no address, no name) */
  if((self->rdaddr == DEV_ADDR_ANY) && (self->rname[0] == '\0'))
    {
      /* Try to find a suitable address */
      if((err = irnet_discover_daddr_and_lsap_sel(self)) != 0)
	DRETURN(err, IRDA_SOCK_INFO, "auto-connect failed!\n");
      /* In most cases, the call above is non-blocking */
    }
  else
    {
      /* If we have only the name (no address), try to get an address */
      if(self->rdaddr == DEV_ADDR_ANY)
	{
	  if((err = irnet_dname_to_daddr(self)) != 0)
	    DRETURN(err, IRDA_SOCK_INFO, "name connect failed!\n");
	}
      else
	/* Use the requested destination address */
	self->daddr = self->rdaddr;

      /* Query remote LM-IAS to find LSAP selector */
      irnet_find_lsap_sel(self);
      /* The above call is non blocking */
    }

  /* At this point, we are waiting for the IrDA stack to call us back,
   * or we have already failed.
   * We will finish the connection procedure in irnet_connect_tsap().
   */
  DEXIT(IRDA_SOCK_TRACE, "\n");
  return(0);
}

/*------------------------------------------------------------------*/
/*
 * Function irda_irnet_destroy(self)
 *
 *    Destroy irnet instance
 *
 * Note : this need to be called from a process context.
 */
void
irda_irnet_destroy(irnet_socket *	self)
{
  DENTER(IRDA_SOCK_TRACE, "(self=0x%X)\n", (unsigned int) self);
  if(self == NULL)
    return;

  /* Remove ourselves from hashbin (if we are queued in hashbin)
   * Note : `irnet_server.running' protect us from calls in hashbin_delete() */
  if((irnet_server.running) && (self->q.q_next != NULL))
    {
      struct irnet_socket *	entry;
      unsigned long		flags;
      DEBUG(IRDA_SOCK_INFO, "Removing from hash..\n");
      spin_lock_irqsave(&irnet_server.spinlock, flags);
      entry = hashbin_remove_this(irnet_server.list, (irda_queue_t *) self);
      self->q.q_next = NULL;
      spin_unlock_irqrestore(&irnet_server.spinlock, flags);
      DASSERT(entry == self, , IRDA_SOCK_ERROR, "Can't remove from hash.\n");
    }

  /* If we were connected, post a message */
  if(test_bit(0, &self->ttp_open))
    {
      /* 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->saddr, self->daddr, self->rname);
    }

  /* Prevent various IrDA callbacks from messing up things
   * Need to be first */
  clear_bit(0, &self->ttp_connect);

  /* Prevent higher layer from accessing IrTTP */
  clear_bit(0, &self->ttp_open);

  /* Unregister with IrLMP */
  irlmp_unregister_client(self->ckey);

  /* Unregister with LM-IAS */
  if(self->iriap)
    { 
      iriap_close(self->iriap);
      self->iriap = NULL;
    }

  /* Cleanup eventual discoveries from connection attempt */
  if(self->discoveries != NULL)
    {
      /* Cleanup our copy of the discovery log */
      kfree(self->discoveries);
      self->discoveries = NULL;
    }

  /* 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;
    }
  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 incoming 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,
				      DISCOVERY_DEFAULT_SLOTS);
  /* 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 addresses of the requester */
  self->daddr = irttp_get_daddr(self->tsap);
  self->saddr = irttp_get_saddr(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->rdaddr == 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(!(test_bit(0, &new->ttp_open)) && (new->rdaddr == 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 incoming connection to the socket
 *
 */
static inline int
irnet_connect_socket(irnet_socket *	server,
		     irnet_socket *	new,
		     struct qos_info *	qos,
		     __u32		max_sdu_size,
		     __u8		max_header_size)
{
  DENTER(IRDA_SERV_TRACE, "(server=0x%X, new=0x%X)\n",
	 (unsigned int) server, (unsigned int) new);

  /* Now attach up the new socket */
  new->tsap = irttp_dup(server->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 */
  irttp_listen(server->tsap);

  /* 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... */
  set_bit(0, &new->ttp_open);

  /* Not connecting anymore, and clean up last possible remains
   * of connection attempts on the socket */
  clear_bit(0, &new->ttp_connect);
  if(new->iriap)
    {
      iriap_close(new->iriap);
      new->iriap = NULL;
    }
  if(new->discoveries != NULL)
    {
      kfree(new->discoveries);
      new->discoveries = NULL;
    }

#ifdef CONNECT_INDIC_KICK
  /* As currently we don't block packets in ppp_irnet_send() while passive,
   * this is not really 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->saddr, new->daddr, server->rname);

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

/*------------------------------------------------------------------*/
/*
 * Function irda_disconnect_server (self)
 *
 *    Cleanup the server socket when the incoming 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 */

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

  /* Clean up the server to keep it in listen state */
  irttp_listen(self->tsap);

  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.