af_irda.c

linux 内核源代码

/*
 * Function irda_open_lsap (self)
 *
 *    Open local Link Service Access Point (LSAP). Used for opening Ultra
 *    sockets
 */
#ifdef CONFIG_IRDA_ULTRA
static int irda_open_lsap(struct irda_sock *self, int pid)
{
	notify_t notify;

	if (self->lsap) {
		IRDA_WARNING("%s(), busy!\n", __FUNCTION__);
		return -EBUSY;
	}

	/* Initialize callbacks to be used by the IrDA stack */
	irda_notify_init(&notify);
	notify.udata_indication	= irda_data_indication;
	notify.instance = self;
	strncpy(notify.name, "Ultra", NOTIFY_MAX_NAME);

	self->lsap = irlmp_open_lsap(LSAP_CONNLESS, &notify, pid);
	if (self->lsap == NULL) {
		IRDA_DEBUG( 0, "%s(), Unable to allocate LSAP!\n", __FUNCTION__);
		return -ENOMEM;
	}

	return 0;
}
#endif /* CONFIG_IRDA_ULTRA */

/*
 * Function irda_find_lsap_sel (self, name)
 *
 *    Try to lookup LSAP selector in remote LM-IAS
 *
 * Basically, we start a IAP query, and then go to sleep. When the query
 * return, irda_getvalue_confirm will wake us up, and we can examine the
 * result of the query...
 * Note that in some case, the query fail even before we go to sleep,
 * creating some races...
 */
static int irda_find_lsap_sel(struct irda_sock *self, char *name)
{
	IRDA_DEBUG(2, "%s(%p, %s)\n", __FUNCTION__, self, name);

	if (self->iriap) {
		IRDA_WARNING("%s(): busy with a previous query\n",
			     __FUNCTION__);
		return -EBUSY;
	}

	self->iriap = iriap_open(LSAP_ANY, IAS_CLIENT, self,
				 irda_getvalue_confirm);
	if(self->iriap == NULL)
		return -ENOMEM;

	/* Treat unexpected wakeup as disconnect */
	self->errno = -EHOSTUNREACH;

	/* Query remote LM-IAS */
	iriap_getvaluebyclass_request(self->iriap, self->saddr, self->daddr,
				      name, "IrDA:TinyTP:LsapSel");

	/* Wait for answer, if not yet finished (or failed) */
	if (wait_event_interruptible(self->query_wait, (self->iriap==NULL)))
		/* Treat signals as disconnect */
		return -EHOSTUNREACH;

	/* Check what happened */
	if (self->errno)
	{
		/* Requested object/attribute doesn't exist */
		if((self->errno == IAS_CLASS_UNKNOWN) ||
		   (self->errno == IAS_ATTRIB_UNKNOWN))
			return (-EADDRNOTAVAIL);
		else
			return (-EHOSTUNREACH);
	}

	/* Get the remote TSAP selector */
	switch (self->ias_result->type) {
	case IAS_INTEGER:
		IRDA_DEBUG(4, "%s() int=%d\n",
			   __FUNCTION__, self->ias_result->t.integer);

		if (self->ias_result->t.integer != -1)
			self->dtsap_sel = self->ias_result->t.integer;
		else
			self->dtsap_sel = 0;
		break;
	default:
		self->dtsap_sel = 0;
		IRDA_DEBUG(0, "%s(), bad type!\n", __FUNCTION__);
		break;
	}
	if (self->ias_result)
		irias_delete_value(self->ias_result);

	if (self->dtsap_sel)
		return 0;

	return -EADDRNOTAVAIL;
}

/*
 * Function irda_discover_daddr_and_lsap_sel (self, name)
 *
 *    This try to find a device with the requested service.
 *
 * It basically look into the discovery log. For each address in the list,
 * it queries the LM-IAS of the device to find if this device offer
 * the requested service.
 * If there is more than one node supporting the service, we complain
 * to the user (it should move devices around).
 * The, we set both the destination address and the lsap selector to point
 * on the service on the unique device we have found.
 *
 * Note : this function fails if there is more than one device in range,
 * because IrLMP doesn't disconnect the LAP when the last LSAP is closed.
 * Moreover, we would need to wait the LAP disconnection...
 */
static int irda_discover_daddr_and_lsap_sel(struct irda_sock *self, char *name)
{
	discinfo_t *discoveries;	/* Copy of the discovery log */
	int	number;			/* Number of nodes in the log */
	int	i;
	int	err = -ENETUNREACH;
	__u32	daddr = DEV_ADDR_ANY;	/* Address we found the service on */
	__u8	dtsap_sel = 0x0;	/* TSAP associated with it */

	IRDA_DEBUG(2, "%s(), name=%s\n", __FUNCTION__, name);

	/* Ask lmp for the current discovery log
	 * Note : we have to use irlmp_get_discoveries(), as opposed
	 * to play with the cachelog directly, because while we are
	 * making our ias query, le log might change... */
	discoveries = irlmp_get_discoveries(&number, self->mask.word,
					    self->nslots);
	/* Check if the we got some results */
	if (discoveries == NULL)
		return -ENETUNREACH;	/* No nodes discovered */

	/*
	 * Now, check all discovered devices (if any), and connect
	 * client only about the services that the client is
	 * interested in...
	 */
	for(i = 0; i < number; i++) {
		/* Try the address in the log */
		self->daddr = discoveries[i].daddr;
		self->saddr = 0x0;
		IRDA_DEBUG(1, "%s(), trying daddr = %08x\n",
			   __FUNCTION__, self->daddr);

		/* Query remote LM-IAS for this service */
		err = irda_find_lsap_sel(self, name);
		switch (err) {
		case 0:
			/* We found the requested service */
			if(daddr != DEV_ADDR_ANY) {
				IRDA_DEBUG(1, "%s(), discovered service ''%s'' in two different devices !!!\n",
					   __FUNCTION__, name);
				self->daddr = DEV_ADDR_ANY;
				kfree(discoveries);
				return(-ENOTUNIQ);
			}
			/* First time we found that one, save it ! */
			daddr = self->daddr;
			dtsap_sel = self->dtsap_sel;
			break;
		case -EADDRNOTAVAIL:
			/* Requested service simply doesn't exist on this node */
			break;
		default:
			/* Something bad did happen :-( */
			IRDA_DEBUG(0, "%s(), unexpected IAS query failure\n", __FUNCTION__);
			self->daddr = DEV_ADDR_ANY;
			kfree(discoveries);
			return(-EHOSTUNREACH);
			break;
		}
	}
	/* Cleanup our copy of the discovery log */
	kfree(discoveries);

	/* Check out what we found */
	if(daddr == DEV_ADDR_ANY) {
		IRDA_DEBUG(1, "%s(), cannot discover service ''%s'' in any device !!!\n",
			   __FUNCTION__, name);
		self->daddr = DEV_ADDR_ANY;
		return(-EADDRNOTAVAIL);
	}

	/* Revert back to discovered device & service */
	self->daddr = daddr;
	self->saddr = 0x0;
	self->dtsap_sel = dtsap_sel;

	IRDA_DEBUG(1, "%s(), discovered requested service ''%s'' at address %08x\n",
		   __FUNCTION__, name, self->daddr);

	return 0;
}

/*
 * Function irda_getname (sock, uaddr, uaddr_len, peer)
 *
 *    Return the our own, or peers socket address (sockaddr_irda)
 *
 */
static int irda_getname(struct socket *sock, struct sockaddr *uaddr,
			int *uaddr_len, int peer)
{
	struct sockaddr_irda saddr;
	struct sock *sk = sock->sk;
	struct irda_sock *self = irda_sk(sk);

	if (peer) {
		if (sk->sk_state != TCP_ESTABLISHED)
			return -ENOTCONN;

		saddr.sir_family = AF_IRDA;
		saddr.sir_lsap_sel = self->dtsap_sel;
		saddr.sir_addr = self->daddr;
	} else {
		saddr.sir_family = AF_IRDA;
		saddr.sir_lsap_sel = self->stsap_sel;
		saddr.sir_addr = self->saddr;
	}

	IRDA_DEBUG(1, "%s(), tsap_sel = %#x\n", __FUNCTION__, saddr.sir_lsap_sel);
	IRDA_DEBUG(1, "%s(), addr = %08x\n", __FUNCTION__, saddr.sir_addr);

	/* uaddr_len come to us uninitialised */
	*uaddr_len = sizeof (struct sockaddr_irda);
	memcpy(uaddr, &saddr, *uaddr_len);

	return 0;
}

/*
 * Function irda_listen (sock, backlog)
 *
 *    Just move to the listen state
 *
 */
static int irda_listen(struct socket *sock, int backlog)
{
	struct sock *sk = sock->sk;

	IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

	if ((sk->sk_type != SOCK_STREAM) && (sk->sk_type != SOCK_SEQPACKET) &&
	    (sk->sk_type != SOCK_DGRAM))
		return -EOPNOTSUPP;

	if (sk->sk_state != TCP_LISTEN) {
		sk->sk_max_ack_backlog = backlog;
		sk->sk_state           = TCP_LISTEN;

		return 0;
	}

	return -EOPNOTSUPP;
}

/*
 * Function irda_bind (sock, uaddr, addr_len)
 *
 *    Used by servers to register their well known TSAP
 *
 */
static int irda_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
	struct sock *sk = sock->sk;
	struct sockaddr_irda *addr = (struct sockaddr_irda *) uaddr;
	struct irda_sock *self = irda_sk(sk);
	int err;

	IRDA_DEBUG(2, "%s(%p)\n", __FUNCTION__, self);

	if (addr_len != sizeof(struct sockaddr_irda))
		return -EINVAL;

#ifdef CONFIG_IRDA_ULTRA
	/* Special care for Ultra sockets */
	if ((sk->sk_type == SOCK_DGRAM) &&
	    (sk->sk_protocol == IRDAPROTO_ULTRA)) {
		self->pid = addr->sir_lsap_sel;
		if (self->pid & 0x80) {
			IRDA_DEBUG(0, "%s(), extension in PID not supp!\n", __FUNCTION__);
			return -EOPNOTSUPP;
		}
		err = irda_open_lsap(self, self->pid);
		if (err < 0)
			return err;

		/* Pretend we are connected */
		sock->state = SS_CONNECTED;
		sk->sk_state   = TCP_ESTABLISHED;

		return 0;
	}
#endif /* CONFIG_IRDA_ULTRA */

	self->ias_obj = irias_new_object(addr->sir_name, jiffies);
	if (self->ias_obj == NULL)
		return -ENOMEM;

	err = irda_open_tsap(self, addr->sir_lsap_sel, addr->sir_name);
	if (err < 0) {
		kfree(self->ias_obj->name);
		kfree(self->ias_obj);
		return err;
	}

	/*  Register with LM-IAS */
	irias_add_integer_attrib(self->ias_obj, "IrDA:TinyTP:LsapSel",
				 self->stsap_sel, IAS_KERNEL_ATTR);
	irias_insert_object(self->ias_obj);

	return 0;
}

/*
 * Function irda_accept (sock, newsock, flags)
 *
 *    Wait for incoming connection
 *
 */
static int irda_accept(struct socket *sock, struct socket *newsock, int flags)
{
	struct sock *sk = sock->sk;
	struct irda_sock *new, *self = irda_sk(sk);
	struct sock *newsk;
	struct sk_buff *skb;
	int err;

	IRDA_DEBUG(2, "%s()\n", __FUNCTION__);

	err = irda_create(sk->sk_net, newsock, sk->sk_protocol);
	if (err)
		return err;

	if (sock->state != SS_UNCONNECTED)
		return -EINVAL;

	if ((sk = sock->sk) == NULL)
		return -EINVAL;

	if ((sk->sk_type != SOCK_STREAM) && (sk->sk_type != SOCK_SEQPACKET) &&
	    (sk->sk_type != SOCK_DGRAM))
		return -EOPNOTSUPP;

	if (sk->sk_state != TCP_LISTEN)
		return -EINVAL;

	/*
	 *	The read queue this time is holding sockets ready to use
	 *	hooked into the SABM we saved
	 */

	/*
	 * We can perform the accept only if there is incoming data
	 * on the listening socket.
	 * So, we will block the caller until we receive any data.
	 * If the caller was waiting on select() or poll() before
	 * calling us, the data is waiting for us ;-)
	 * Jean II
	 */
	while (1) {
		skb = skb_dequeue(&sk->sk_receive_queue);
		if (skb)
			break;

		/* Non blocking operation */
		if (flags & O_NONBLOCK)
			return -EWOULDBLOCK;

		err = wait_event_interruptible(*(sk->sk_sleep),
					skb_peek(&sk->sk_receive_queue));
		if (err)
			return err;
	}

	newsk = newsock->sk;
	if (newsk == NULL)
		return -EIO;

	newsk->sk_state = TCP_ESTABLISHED;

	new = irda_sk(newsk);

	/* Now attach up the new socket */
	new->tsap = irttp_dup(self->tsap, new);
	if (!new->tsap) {
		IRDA_DEBUG(0, "%s(), dup failed!\n", __FUNCTION__);
		kfree_skb(skb);
		return -1;
	}

	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_sdu_size_tx = self->max_sdu_size_tx;
	new->max_sdu_size_rx = self->max_sdu_size_rx;
	new->max_data_size   = self->max_data_size;
	new->max_header_size = self->max_header_size;

	memcpy(&new->qos_tx, &self->qos_tx, sizeof(struct qos_info));

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

	/* Wow ! What is that ? Jean II */
	skb->sk = NULL;
	skb->destructor = NULL;
	kfree_skb(skb);
	sk->sk_ack_backlog--;

	newsock->state = SS_CONNECTED;

	irda_connect_response(new);

	return 0;
}

/*
 * Function irda_connect (sock, uaddr, addr_len, flags)
 *
 *    Connect to a IrDA device
 *
 * The main difference with a "standard" connect is that with IrDA we need
 * to resolve the service name into a TSAP selector (in TCP, port number
 * doesn't have to be resolved).
 * Because of this service name resoltion, we can offer "auto-connect",
 * where we connect to a service without specifying a destination address.
 *
 * Note : by consulting "errno", the user space caller may learn the cause
 * of the failure. Most of them are visible in the function, others may come
 * from subroutines called and are listed here :
 *	o EBUSY : already processing a connect
 *	o EHOSTUNREACH : bad addr->sir_addr argument
 *	o EADDRNOTAVAIL : bad addr->sir_name argument
 *	o ENOTUNIQ : more than one node has addr->sir_name (auto-connect)
 *	o ENETUNREACH : no node found on the network (auto-connect)
 */
static int irda_connect(struct socket *sock, struct sockaddr *uaddr,
			int addr_len, int flags)
{
	struct sock *sk = sock->sk;
	struct sockaddr_irda *addr = (struct sockaddr_irda *) uaddr;
	struct irda_sock *self = irda_sk(sk);
	int err;

	IRDA_DEBUG(2, "%s(%p)\n", __FUNCTION__, self);

	/* Don't allow connect for Ultra sockets */
	if ((sk->sk_type == SOCK_DGRAM) && (sk->sk_protocol == IRDAPROTO_ULTRA))
		return -ESOCKTNOSUPPORT;

	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
		sock->state = SS_CONNECTED;
		return 0;   /* Connect completed during a ERESTARTSYS event */
	}

	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
		sock->state = SS_UNCONNECTED;
		return -ECONNREFUSED;
	}

	if (sk->sk_state == TCP_ESTABLISHED)
		return -EISCONN;      /* No reconnect on a seqpacket socket */

	sk->sk_state   = TCP_CLOSE;
	sock->state = SS_UNCONNECTED;

	if (addr_len != sizeof(struct sockaddr_irda))
		return -EINVAL;

	/* Check if user supplied any destination device address */
	if ((!addr->sir_addr) || (addr->sir_addr == DEV_ADDR_ANY)) {
		/* Try to find one suitable */
		err = irda_discover_daddr_and_lsap_sel(self, addr->sir_name);
		if (err) {
			IRDA_DEBUG(0, "%s(), auto-connect failed!\n", __FUNCTION__);
			return err;
		}
	} else {
		/* Use the one provided by the user */
		self->daddr = addr->sir_addr;
		IRDA_DEBUG(1, "%s(), daddr = %08x\n", __FUNCTION__, self->daddr);