irlmp.c

linux 内核源代码

	if (!service) {
		IRDA_DEBUG(1, "%s(), Unknown service!\n", __FUNCTION__);
		return -1;
	}

	hashbin_remove_this(irlmp->services, (irda_queue_t *) service);
	kfree(service);

	/* Remove old hint bits */
	irlmp->hints.word = 0;

	/* Refresh current hint bits */
	spin_lock_irqsave(&irlmp->services->hb_spinlock, flags);
	service = (irlmp_service_t *) hashbin_get_first(irlmp->services);
	while (service) {
		irlmp->hints.word |= service->hints.word;

		service = (irlmp_service_t *)hashbin_get_next(irlmp->services);
	}
	spin_unlock_irqrestore(&irlmp->services->hb_spinlock, flags);
	return 0;
}
EXPORT_SYMBOL(irlmp_unregister_service);

/*
 * Function irlmp_register_client (hint_mask, callback1, callback2)
 *
 *    Register a local client with IrLMP
 *	First callback is selective discovery (based on hints)
 *	Second callback is for selective discovery expiries
 *
 *    Returns: handle > 0 on success, 0 on error
 */
void *irlmp_register_client(__u16 hint_mask, DISCOVERY_CALLBACK1 disco_clb,
			    DISCOVERY_CALLBACK2 expir_clb, void *priv)
{
	irlmp_client_t *client;

	IRDA_DEBUG(1, "%s()\n", __FUNCTION__);
	IRDA_ASSERT(irlmp != NULL, return NULL;);

	/* Make a new registration */
	client = kmalloc(sizeof(irlmp_client_t), GFP_ATOMIC);
	if (!client) {
		IRDA_DEBUG( 1, "%s(), Unable to kmalloc!\n", __FUNCTION__);
		return NULL;
	}

	/* Register the details */
	client->hint_mask.word = hint_mask;
	client->disco_callback = disco_clb;
	client->expir_callback = expir_clb;
	client->priv = priv;

	hashbin_insert(irlmp->clients, (irda_queue_t *) client,
		       (long) client, NULL);

	return (void *) client;
}
EXPORT_SYMBOL(irlmp_register_client);

/*
 * Function irlmp_update_client (handle, hint_mask, callback1, callback2)
 *
 *    Updates specified client (handle) with possibly new hint_mask and
 *    callback
 *
 *    Returns: 0 on success, -1 on error
 */
int irlmp_update_client(void *handle, __u16 hint_mask,
			DISCOVERY_CALLBACK1 disco_clb,
			DISCOVERY_CALLBACK2 expir_clb, void *priv)
{
	irlmp_client_t *client;

	if (!handle)
		return -1;

	client = hashbin_lock_find(irlmp->clients, (long) handle, NULL);
	if (!client) {
		IRDA_DEBUG(1, "%s(), Unknown client!\n", __FUNCTION__);
		return -1;
	}

	client->hint_mask.word = hint_mask;
	client->disco_callback = disco_clb;
	client->expir_callback = expir_clb;
	client->priv = priv;

	return 0;
}
EXPORT_SYMBOL(irlmp_update_client);

/*
 * Function irlmp_unregister_client (handle)
 *
 *    Returns: 0 on success, -1 on error
 *
 */
int irlmp_unregister_client(void *handle)
{
	struct irlmp_client *client;

	IRDA_DEBUG(4, "%s()\n", __FUNCTION__);

	if (!handle)
		return -1;

	/* Caller may call with invalid handle (it's legal) - Jean II */
	client = hashbin_lock_find(irlmp->clients, (long) handle, NULL);
	if (!client) {
		IRDA_DEBUG(1, "%s(), Unknown client!\n", __FUNCTION__);
		return -1;
	}

	IRDA_DEBUG(4, "%s(), removing client!\n", __FUNCTION__);
	hashbin_remove_this(irlmp->clients, (irda_queue_t *) client);
	kfree(client);

	return 0;
}
EXPORT_SYMBOL(irlmp_unregister_client);

/*
 * Function irlmp_slsap_inuse (slsap)
 *
 *    Check if the given source LSAP selector is in use
 *
 * This function is clearly not very efficient. On the mitigating side, the
 * stack make sure that in 99% of the cases, we are called only once
 * for each socket allocation. We could probably keep a bitmap
 * of the allocated LSAP, but I'm not sure the complexity is worth it.
 * Jean II
 */
static int irlmp_slsap_inuse(__u8 slsap_sel)
{
	struct lsap_cb *self;
	struct lap_cb *lap;
	unsigned long flags;

	IRDA_ASSERT(irlmp != NULL, return TRUE;);
	IRDA_ASSERT(irlmp->magic == LMP_MAGIC, return TRUE;);
	IRDA_ASSERT(slsap_sel != LSAP_ANY, return TRUE;);

	IRDA_DEBUG(4, "%s()\n", __FUNCTION__);

#ifdef CONFIG_IRDA_ULTRA
	/* Accept all bindings to the connectionless LSAP */
	if (slsap_sel == LSAP_CONNLESS)
		return FALSE;
#endif /* CONFIG_IRDA_ULTRA */

	/* Valid values are between 0 and 127 (0x0-0x6F) */
	if (slsap_sel > LSAP_MAX)
		return TRUE;

	/*
	 *  Check if slsap is already in use. To do this we have to loop over
	 *  every IrLAP connection and check every LSAP associated with each
	 *  the connection.
	 */
	spin_lock_irqsave_nested(&irlmp->links->hb_spinlock, flags,
			SINGLE_DEPTH_NESTING);
	lap = (struct lap_cb *) hashbin_get_first(irlmp->links);
	while (lap != NULL) {
		IRDA_ASSERT(lap->magic == LMP_LAP_MAGIC, goto errlap;);

		/* Careful for priority inversions here !
		 * irlmp->links is never taken while another IrDA
		 * spinlock is held, so we are safe. Jean II */
		spin_lock(&lap->lsaps->hb_spinlock);

		/* For this IrLAP, check all the LSAPs */
		self = (struct lsap_cb *) hashbin_get_first(lap->lsaps);
		while (self != NULL) {
			IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC,
				    goto errlsap;);

			if ((self->slsap_sel == slsap_sel)) {
				IRDA_DEBUG(4, "Source LSAP selector=%02x in use\n",
					   self->slsap_sel);
				goto errlsap;
			}
			self = (struct lsap_cb*) hashbin_get_next(lap->lsaps);
		}
		spin_unlock(&lap->lsaps->hb_spinlock);

		/* Next LAP */
		lap = (struct lap_cb *) hashbin_get_next(irlmp->links);
	}
	spin_unlock_irqrestore(&irlmp->links->hb_spinlock, flags);

	/*
	 * Server sockets are typically waiting for connections and
	 * therefore reside in the unconnected list. We don't want
	 * to give out their LSAPs for obvious reasons...
	 * Jean II
	 */
	spin_lock_irqsave(&irlmp->unconnected_lsaps->hb_spinlock, flags);

	self = (struct lsap_cb *) hashbin_get_first(irlmp->unconnected_lsaps);
	while (self != NULL) {
		IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, goto erruncon;);
		if ((self->slsap_sel == slsap_sel)) {
			IRDA_DEBUG(4, "Source LSAP selector=%02x in use (unconnected)\n",
				   self->slsap_sel);
			goto erruncon;
		}
		self = (struct lsap_cb*) hashbin_get_next(irlmp->unconnected_lsaps);
	}
	spin_unlock_irqrestore(&irlmp->unconnected_lsaps->hb_spinlock, flags);

	return FALSE;

	/* Error exit from within one of the two nested loops.
	 * Make sure we release the right spinlock in the righ order.
	 * Jean II */
errlsap:
	spin_unlock(&lap->lsaps->hb_spinlock);
IRDA_ASSERT_LABEL(errlap:)
	spin_unlock_irqrestore(&irlmp->links->hb_spinlock, flags);
	return TRUE;

	/* Error exit from within the unconnected loop.
	 * Just one spinlock to release... Jean II */
erruncon:
	spin_unlock_irqrestore(&irlmp->unconnected_lsaps->hb_spinlock, flags);
	return TRUE;
}

/*
 * Function irlmp_find_free_slsap ()
 *
 *    Find a free source LSAP to use. This function is called if the service
 *    user has requested a source LSAP equal to LM_ANY
 */
static __u8 irlmp_find_free_slsap(void)
{
	__u8 lsap_sel;
	int wrapped = 0;

	IRDA_ASSERT(irlmp != NULL, return -1;);
	IRDA_ASSERT(irlmp->magic == LMP_MAGIC, return -1;);

	/* Most users don't really care which LSAPs they are given,
	 * and therefore we automatically give them a free LSAP.
	 * This function try to find a suitable LSAP, i.e. which is
	 * not in use and is within the acceptable range. Jean II */

	do {
		/* Always increment to LSAP number before using it.
		 * In theory, we could reuse the last LSAP number, as long
		 * as it is no longer in use. Some IrDA stack do that.
		 * However, the previous socket may be half closed, i.e.
		 * we closed it, we think it's no longer in use, but the
		 * other side did not receive our close and think it's
		 * active and still send data on it.
		 * This is similar to what is done with PIDs and TCP ports.
		 * Also, this reduce the number of calls to irlmp_slsap_inuse()
		 * which is an expensive function to call.
		 * Jean II */
		irlmp->last_lsap_sel++;

		/* Check if we need to wraparound (0x70-0x7f are reserved) */
		if (irlmp->last_lsap_sel > LSAP_MAX) {
			/* 0x00-0x10 are also reserved for well know ports */
			irlmp->last_lsap_sel = 0x10;

			/* Make sure we terminate the loop */
			if (wrapped++) {
				IRDA_ERROR("%s: no more free LSAPs !\n",
					   __FUNCTION__);
				return 0;
			}
		}

		/* If the LSAP is in use, try the next one.
		 * Despite the autoincrement, we need to check if the lsap
		 * is really in use or not, first because LSAP may be
		 * directly allocated in irlmp_open_lsap(), and also because
		 * we may wraparound on old sockets. Jean II */
	} while (irlmp_slsap_inuse(irlmp->last_lsap_sel));

	/* Got it ! */
	lsap_sel = irlmp->last_lsap_sel;
	IRDA_DEBUG(4, "%s(), found free lsap_sel=%02x\n",
		   __FUNCTION__, lsap_sel);

	return lsap_sel;
}

/*
 * Function irlmp_convert_lap_reason (lap_reason)
 *
 *    Converts IrLAP disconnect reason codes to IrLMP disconnect reason
 *    codes
 *
 */
LM_REASON irlmp_convert_lap_reason( LAP_REASON lap_reason)
{
	int reason = LM_LAP_DISCONNECT;

	switch (lap_reason) {
	case LAP_DISC_INDICATION: /* Received a disconnect request from peer */
		IRDA_DEBUG( 1, "%s(), LAP_DISC_INDICATION\n", __FUNCTION__);
		reason = LM_USER_REQUEST;
		break;
	case LAP_NO_RESPONSE:    /* To many retransmits without response */
		IRDA_DEBUG( 1, "%s(), LAP_NO_RESPONSE\n", __FUNCTION__);
		reason = LM_LAP_DISCONNECT;
		break;
	case LAP_RESET_INDICATION:
		IRDA_DEBUG( 1, "%s(), LAP_RESET_INDICATION\n", __FUNCTION__);
		reason = LM_LAP_RESET;
		break;
	case LAP_FOUND_NONE:
	case LAP_MEDIA_BUSY:
	case LAP_PRIMARY_CONFLICT:
		IRDA_DEBUG(1, "%s(), LAP_FOUND_NONE, LAP_MEDIA_BUSY or LAP_PRIMARY_CONFLICT\n", __FUNCTION__);
		reason = LM_CONNECT_FAILURE;
		break;
	default:
		IRDA_DEBUG(1, "%s(), Unknow IrLAP disconnect reason %d!\n",
			   __FUNCTION__, lap_reason);
		reason = LM_LAP_DISCONNECT;
		break;
	}

	return reason;
}

#ifdef CONFIG_PROC_FS

struct irlmp_iter_state {
	hashbin_t *hashbin;
};

#define LSAP_START_TOKEN	((void *)1)
#define LINK_START_TOKEN	((void *)2)

static void *irlmp_seq_hb_idx(struct irlmp_iter_state *iter, loff_t *off)
{
	void *element;

	spin_lock_irq(&iter->hashbin->hb_spinlock);
	for (element = hashbin_get_first(iter->hashbin);
	     element != NULL;
	     element = hashbin_get_next(iter->hashbin)) {
		if (!off || *off-- == 0) {
			/* NB: hashbin left locked */
			return element;
		}
	}
	spin_unlock_irq(&iter->hashbin->hb_spinlock);
	iter->hashbin = NULL;
	return NULL;
}


static void *irlmp_seq_start(struct seq_file *seq, loff_t *pos)
{
	struct irlmp_iter_state *iter = seq->private;
	void *v;
	loff_t off = *pos;

	iter->hashbin = NULL;
	if (off-- == 0)
		return LSAP_START_TOKEN;

	iter->hashbin = irlmp->unconnected_lsaps;
	v = irlmp_seq_hb_idx(iter, &off);
	if (v)
		return v;

	if (off-- == 0)
		return LINK_START_TOKEN;

	iter->hashbin = irlmp->links;
	return irlmp_seq_hb_idx(iter, &off);
}

static void *irlmp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	struct irlmp_iter_state *iter = seq->private;

	++*pos;

	if (v == LSAP_START_TOKEN) {		/* start of list of lsaps */
		iter->hashbin = irlmp->unconnected_lsaps;
		v = irlmp_seq_hb_idx(iter, NULL);
		return v ? v : LINK_START_TOKEN;
	}

	if (v == LINK_START_TOKEN) {		/* start of list of links */
		iter->hashbin = irlmp->links;
		return irlmp_seq_hb_idx(iter, NULL);
	}

	v = hashbin_get_next(iter->hashbin);

	if (v == NULL) {			/* no more in this hash bin */
		spin_unlock_irq(&iter->hashbin->hb_spinlock);

		if (iter->hashbin == irlmp->unconnected_lsaps)
			v =  LINK_START_TOKEN;

		iter->hashbin = NULL;
	}
	return v;
}

static void irlmp_seq_stop(struct seq_file *seq, void *v)
{
	struct irlmp_iter_state *iter = seq->private;

	if (iter->hashbin)
		spin_unlock_irq(&iter->hashbin->hb_spinlock);
}

static int irlmp_seq_show(struct seq_file *seq, void *v)
{
	const struct irlmp_iter_state *iter = seq->private;
	struct lsap_cb *self = v;

	if (v == LSAP_START_TOKEN)
		seq_puts(seq, "Unconnected LSAPs:\n");
	else if (v == LINK_START_TOKEN)
		seq_puts(seq, "\nRegistered Link Layers:\n");
	else if (iter->hashbin == irlmp->unconnected_lsaps) {
		self = v;
		IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC, return -EINVAL; );
		seq_printf(seq, "lsap state: %s, ",
			   irlsap_state[ self->lsap_state]);
		seq_printf(seq,
			   "slsap_sel: %#02x, dlsap_sel: %#02x, ",
			   self->slsap_sel, self->dlsap_sel);
		seq_printf(seq, "(%s)", self->notify.name);
		seq_printf(seq, "\n");
	} else if (iter->hashbin == irlmp->links) {
		struct lap_cb *lap = v;

		seq_printf(seq, "lap state: %s, ",
			   irlmp_state[lap->lap_state]);

		seq_printf(seq, "saddr: %#08x, daddr: %#08x, ",
			   lap->saddr, lap->daddr);
		seq_printf(seq, "num lsaps: %d",
			   HASHBIN_GET_SIZE(lap->lsaps));
		seq_printf(seq, "\n");

		/* Careful for priority inversions here !
		 * All other uses of attrib spinlock are independent of
		 * the object spinlock, so we are safe. Jean II */
		spin_lock(&lap->lsaps->hb_spinlock);

		seq_printf(seq, "\n  Connected LSAPs:\n");
		for (self = (struct lsap_cb *) hashbin_get_first(lap->lsaps);
		     self != NULL;
		     self = (struct lsap_cb *)hashbin_get_next(lap->lsaps)) {
			IRDA_ASSERT(self->magic == LMP_LSAP_MAGIC,
				    goto outloop;);
			seq_printf(seq, "  lsap state: %s, ",
				   irlsap_state[ self->lsap_state]);
			seq_printf(seq,
				   "slsap_sel: %#02x, dlsap_sel: %#02x, ",
				   self->slsap_sel, self->dlsap_sel);
			seq_printf(seq, "(%s)", self->notify.name);
			seq_putc(seq, '\n');

		}
	IRDA_ASSERT_LABEL(outloop:)
		spin_unlock(&lap->lsaps->hb_spinlock);
		seq_putc(seq, '\n');
	} else
		return -EINVAL;

	return 0;
}

static const struct seq_operations irlmp_seq_ops = {
	.start  = irlmp_seq_start,
	.next   = irlmp_seq_next,
	.stop   = irlmp_seq_stop,
	.show   = irlmp_seq_show,
};

static int irlmp_seq_open(struct inode *inode, struct file *file)
{
	IRDA_ASSERT(irlmp != NULL, return -EINVAL;);

	return seq_open_private(file, &irlmp_seq_ops,
			sizeof(struct irlmp_iter_state));
}

const struct file_operations irlmp_seq_fops = {
	.owner		= THIS_MODULE,
	.open           = irlmp_seq_open,
	.read           = seq_read,
	.llseek         = seq_lseek,
	.release	= seq_release_private,
};

#endif /* PROC_FS */