irlap.c

linux 内核源代码

/*********************************************************************
 *
 * Filename:      irlap.c
 * Version:       1.0
 * Description:   IrLAP implementation for Linux
 * Status:        Stable
 * Author:        Dag Brattli <[e-mail]>
 * Created at:    Mon Aug  4 20:40:53 1997
 * Modified at:   Tue Dec 14 09:26:44 1999
 * Modified by:   Dag Brattli <[e-mail]>
 *
 *     Copyright (c) 1998-1999 Dag Brattli, All Rights Reserved.
 *     Copyright (c) 2000-2003 Jean Tourrilhes <[e-mail]>
 *
 *     This program is free software; you can redistribute it and/or
 *     modify it under the terms of the GNU General Public License as
 *     published by the Free Software Foundation; either version 2 of
 *     the License, or (at your option) any later version.
 *
 *     This program is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with this program; if not, write to the Free Software
 *     Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 *     MA 02111-1307 USA
 *
 ********************************************************************/

#include <linux/slab.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/random.h>
#include <linux/module.h>
#include <linux/seq_file.h>

#include <net/irda/irda.h>
#include <net/irda/irda_device.h>
#include <net/irda/irqueue.h>
#include <net/irda/irlmp.h>
#include <net/irda/irlmp_frame.h>
#include <net/irda/irlap_frame.h>
#include <net/irda/irlap.h>
#include <net/irda/timer.h>
#include <net/irda/qos.h>

static hashbin_t *irlap = NULL;
int sysctl_slot_timeout = SLOT_TIMEOUT * 1000 / HZ;

/* This is the delay of missed pf period before generating an event
 * to the application. The spec mandate 3 seconds, but in some cases
 * it's way too long. - Jean II */
int sysctl_warn_noreply_time = 3;

extern void irlap_queue_xmit(struct irlap_cb *self, struct sk_buff *skb);
static void __irlap_close(struct irlap_cb *self);
static void irlap_init_qos_capabilities(struct irlap_cb *self,
					struct qos_info *qos_user);

#ifdef CONFIG_IRDA_DEBUG
static char *lap_reasons[] = {
	"ERROR, NOT USED",
	"LAP_DISC_INDICATION",
	"LAP_NO_RESPONSE",
	"LAP_RESET_INDICATION",
	"LAP_FOUND_NONE",
	"LAP_MEDIA_BUSY",
	"LAP_PRIMARY_CONFLICT",
	"ERROR, NOT USED",
};
#endif	/* CONFIG_IRDA_DEBUG */

int __init irlap_init(void)
{
	/* Check if the compiler did its job properly.
	 * May happen on some ARM configuration, check with Russell King. */
	IRDA_ASSERT(sizeof(struct xid_frame) == 14, ;);
	IRDA_ASSERT(sizeof(struct test_frame) == 10, ;);
	IRDA_ASSERT(sizeof(struct ua_frame) == 10, ;);
	IRDA_ASSERT(sizeof(struct snrm_frame) == 11, ;);

	/* Allocate master array */
	irlap = hashbin_new(HB_LOCK);
	if (irlap == NULL) {
		IRDA_ERROR("%s: can't allocate irlap hashbin!\n",
			   __FUNCTION__);
		return -ENOMEM;
	}

	return 0;
}

void irlap_cleanup(void)
{
	IRDA_ASSERT(irlap != NULL, return;);

	hashbin_delete(irlap, (FREE_FUNC) __irlap_close);
}

/*
 * Function irlap_open (driver)
 *
 *    Initialize IrLAP layer
 *
 */
struct irlap_cb *irlap_open(struct net_device *dev, struct qos_info *qos,
			    const char *hw_name)
{
	struct irlap_cb *self;

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

	/* Initialize the irlap structure. */
	self = kzalloc(sizeof(struct irlap_cb), GFP_KERNEL);
	if (self == NULL)
		return NULL;

	self->magic = LAP_MAGIC;

	/* Make a binding between the layers */
	self->netdev = dev;
	self->qos_dev = qos;
	/* Copy hardware name */
	if(hw_name != NULL) {
		strlcpy(self->hw_name, hw_name, sizeof(self->hw_name));
	} else {
		self->hw_name[0] = '\0';
	}

	/* FIXME: should we get our own field? */
	dev->atalk_ptr = self;

	self->state = LAP_OFFLINE;

	/* Initialize transmit queue */
	skb_queue_head_init(&self->txq);
	skb_queue_head_init(&self->txq_ultra);
	skb_queue_head_init(&self->wx_list);

	/* My unique IrLAP device address! */
	/* We don't want the broadcast address, neither the NULL address
	 * (most often used to signify "invalid"), and we don't want an
	 * address already in use (otherwise connect won't be able
	 * to select the proper link). - Jean II */
	do {
		get_random_bytes(&self->saddr, sizeof(self->saddr));
	} while ((self->saddr == 0x0) || (self->saddr == BROADCAST) ||
		 (hashbin_lock_find(irlap, self->saddr, NULL)) );
	/* Copy to the driver */
	memcpy(dev->dev_addr, &self->saddr, 4);

	init_timer(&self->slot_timer);
	init_timer(&self->query_timer);
	init_timer(&self->discovery_timer);
	init_timer(&self->final_timer);
	init_timer(&self->poll_timer);
	init_timer(&self->wd_timer);
	init_timer(&self->backoff_timer);
	init_timer(&self->media_busy_timer);

	irlap_apply_default_connection_parameters(self);

	self->N3 = 3; /* # connections attemts to try before giving up */

	self->state = LAP_NDM;

	hashbin_insert(irlap, (irda_queue_t *) self, self->saddr, NULL);

	irlmp_register_link(self, self->saddr, &self->notify);

	return self;
}
EXPORT_SYMBOL(irlap_open);

/*
 * Function __irlap_close (self)
 *
 *    Remove IrLAP and all allocated memory. Stop any pending timers.
 *
 */
static void __irlap_close(struct irlap_cb *self)
{
	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* Stop timers */
	del_timer(&self->slot_timer);
	del_timer(&self->query_timer);
	del_timer(&self->discovery_timer);
	del_timer(&self->final_timer);
	del_timer(&self->poll_timer);
	del_timer(&self->wd_timer);
	del_timer(&self->backoff_timer);
	del_timer(&self->media_busy_timer);

	irlap_flush_all_queues(self);

	self->magic = 0;

	kfree(self);
}

/*
 * Function irlap_close (self)
 *
 *    Remove IrLAP instance
 *
 */
void irlap_close(struct irlap_cb *self)
{
	struct irlap_cb *lap;

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

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	/* We used to send a LAP_DISC_INDICATION here, but this was
	 * racy. This has been move within irlmp_unregister_link()
	 * itself. Jean II */

	/* Kill the LAP and all LSAPs on top of it */
	irlmp_unregister_link(self->saddr);
	self->notify.instance = NULL;

	/* Be sure that we manage to remove ourself from the hash */
	lap = hashbin_remove(irlap, self->saddr, NULL);
	if (!lap) {
		IRDA_DEBUG(1, "%s(), Didn't find myself!\n", __FUNCTION__);
		return;
	}
	__irlap_close(lap);
}
EXPORT_SYMBOL(irlap_close);

/*
 * Function irlap_connect_indication (self, skb)
 *
 *    Another device is attempting to make a connection
 *
 */
void irlap_connect_indication(struct irlap_cb *self, struct sk_buff *skb)
{
	IRDA_DEBUG(4, "%s()\n", __FUNCTION__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	irlap_init_qos_capabilities(self, NULL); /* No user QoS! */

	irlmp_link_connect_indication(self->notify.instance, self->saddr,
				      self->daddr, &self->qos_tx, skb);
}

/*
 * Function irlap_connect_response (self, skb)
 *
 *    Service user has accepted incoming connection
 *
 */
void irlap_connect_response(struct irlap_cb *self, struct sk_buff *userdata)
{
	IRDA_DEBUG(4, "%s()\n", __FUNCTION__);

	irlap_do_event(self, CONNECT_RESPONSE, userdata, NULL);
}

/*
 * Function irlap_connect_request (self, daddr, qos_user, sniff)
 *
 *    Request connection with another device, sniffing is not implemented
 *    yet.
 *
 */
void irlap_connect_request(struct irlap_cb *self, __u32 daddr,
			   struct qos_info *qos_user, int sniff)
{
	IRDA_DEBUG(3, "%s(), daddr=0x%08x\n", __FUNCTION__, daddr);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	self->daddr = daddr;

	/*
	 *  If the service user specifies QoS values for this connection,
	 *  then use them
	 */
	irlap_init_qos_capabilities(self, qos_user);

	if ((self->state == LAP_NDM) && !self->media_busy)
		irlap_do_event(self, CONNECT_REQUEST, NULL, NULL);
	else
		self->connect_pending = TRUE;
}

/*
 * Function irlap_connect_confirm (self, skb)
 *
 *    Connection request has been accepted
 *
 */
void irlap_connect_confirm(struct irlap_cb *self, struct sk_buff *skb)
{
	IRDA_DEBUG(4, "%s()\n", __FUNCTION__);

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	irlmp_link_connect_confirm(self->notify.instance, &self->qos_tx, skb);
}

/*
 * Function irlap_data_indication (self, skb)
 *
 *    Received data frames from IR-port, so we just pass them up to
 *    IrLMP for further processing
 *
 */
void irlap_data_indication(struct irlap_cb *self, struct sk_buff *skb,
			   int unreliable)
{
	/* Hide LAP header from IrLMP layer */
	skb_pull(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

	irlmp_link_data_indication(self->notify.instance, skb, unreliable);
}


/*
 * Function irlap_data_request (self, skb)
 *
 *    Queue data for transmission, must wait until XMIT state
 *
 */
void irlap_data_request(struct irlap_cb *self, struct sk_buff *skb,
			int unreliable)
{
	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	IRDA_DEBUG(3, "%s()\n", __FUNCTION__);

	IRDA_ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER),
		    return;);
	skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

	/*
	 *  Must set frame format now so that the rest of the code knows
	 *  if its dealing with an I or an UI frame
	 */
	if (unreliable)
		skb->data[1] = UI_FRAME;
	else
		skb->data[1] = I_FRAME;

	/* Don't forget to refcount it - see irlmp_connect_request(). */
	skb_get(skb);

	/* Add at the end of the queue (keep ordering) - Jean II */
	skb_queue_tail(&self->txq, skb);

	/*
	 *  Send event if this frame only if we are in the right state
	 *  FIXME: udata should be sent first! (skb_queue_head?)
	 */
	if ((self->state == LAP_XMIT_P) || (self->state == LAP_XMIT_S)) {
		/* If we are not already processing the Tx queue, trigger
		 * transmission immediately - Jean II */
		if((skb_queue_len(&self->txq) <= 1) && (!self->local_busy))
			irlap_do_event(self, DATA_REQUEST, skb, NULL);
		/* Otherwise, the packets will be sent normally at the
		 * next pf-poll - Jean II */
	}
}

/*
 * Function irlap_unitdata_request (self, skb)
 *
 *    Send Ultra data. This is data that must be sent outside any connection
 *
 */
#ifdef CONFIG_IRDA_ULTRA
void irlap_unitdata_request(struct irlap_cb *self, struct sk_buff *skb)
{
	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LAP_MAGIC, return;);

	IRDA_DEBUG(3, "%s()\n", __FUNCTION__);

	IRDA_ASSERT(skb_headroom(skb) >= (LAP_ADDR_HEADER+LAP_CTRL_HEADER),
	       return;);
	skb_push(skb, LAP_ADDR_HEADER+LAP_CTRL_HEADER);

	skb->data[0] = CBROADCAST;
	skb->data[1] = UI_FRAME;

	/* Don't need to refcount, see irlmp_connless_data_request() */

	skb_queue_tail(&self->txq_ultra, skb);

	irlap_do_event(self, SEND_UI_FRAME, NULL, NULL);
}
#endif /*CONFIG_IRDA_ULTRA */

/*
 * Function irlap_udata_indication (self, skb)
 *