path: root/net/irda/irlmp_frame.c

/*********************************************************************
 *
 * Filename:      irlmp_frame.c
 * Version:       0.9
 * Description:   IrLMP frame implementation
 * Status:        Experimental.
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Tue Aug 19 02:09:59 1997
 * Modified at:   Mon Dec 13 13:41:12 1999
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 *
 *     Copyright (c) 1998-1999 Dag Brattli <dagb@cs.uit.no>
 *     All Rights Reserved.
 *     Copyright (c) 2000-2003 Jean Tourrilhes <jt@hpl.hp.com>
 *
 *     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.
 *
 *     Neither Dag Brattli nor University of Tromsø admit liability nor
 *     provide warranty for any of this software. This material is
 *     provided "AS-IS" and at no charge.
 *
 ********************************************************************/

#include <linux/skbuff.h>
#include <linux/kernel.h>

#include <net/irda/irda.h>
#include <net/irda/irlap.h>
#include <net/irda/timer.h>
#include <net/irda/irlmp.h>
#include <net/irda/irlmp_frame.h>
#include <net/irda/discovery.h>

static struct lsap_cb *irlmp_find_lsap(struct lap_cb *self, __u8 dlsap,
				       __u8 slsap, int status, hashbin_t *);

inline void irlmp_send_data_pdu(struct lap_cb *self, __u8 dlsap, __u8 slsap,
				int expedited, struct sk_buff *skb)
{
	skb->data[0] = dlsap;
	skb->data[1] = slsap;

	if (expedited) {
		IRDA_DEBUG(4, "%s(), sending expedited data\n", __func__);
		irlap_data_request(self->irlap, skb, TRUE);
	} else
		irlap_data_request(self->irlap, skb, FALSE);
}

/*
 * Function irlmp_send_lcf_pdu (dlsap, slsap, opcode,skb)
 *
 *    Send Link Control Frame to IrLAP
 */
void irlmp_send_lcf_pdu(struct lap_cb *self, __u8 dlsap, __u8 slsap,
			__u8 opcode, struct sk_buff *skb)
{
	__u8 *frame;

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

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

	frame = skb->data;

	frame[0] = dlsap | CONTROL_BIT;
	frame[1] = slsap;

	frame[2] = opcode;

	if (opcode == DISCONNECT)
		frame[3] = 0x01; /* Service user request */
	else
		frame[3] = 0x00; /* rsvd */

	irlap_data_request(self->irlap, skb, FALSE);
}

/*
 * Function irlmp_input (skb)
 *
 *    Used by IrLAP to pass received data frames to IrLMP layer
 *
 */
void irlmp_link_data_indication(struct lap_cb *self, struct sk_buff *skb,
				int unreliable)
{
	struct lsap_cb *lsap;
	__u8   slsap_sel;   /* Source (this) LSAP address */
	__u8   dlsap_sel;   /* Destination LSAP address */
	__u8   *fp;

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

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LMP_LAP_MAGIC, return;);
	IRDA_ASSERT(skb->len > 2, return;);

	fp = skb->data;

	/*
	 *  The next statements may be confusing, but we do this so that
	 *  destination LSAP of received frame is source LSAP in our view
	 */
	slsap_sel = fp[0] & LSAP_MASK;
	dlsap_sel = fp[1];

	/*
	 *  Check if this is an incoming connection, since we must deal with
	 *  it in a different way than other established connections.
	 */
	if ((fp[0] & CONTROL_BIT) && (fp[2] == CONNECT_CMD)) {
		IRDA_DEBUG(3, "%s(), incoming connection, "
			   "source LSAP=%d, dest LSAP=%d\n",
			   __func__, slsap_sel, dlsap_sel);

		/* Try to find LSAP among the unconnected LSAPs */
		lsap = irlmp_find_lsap(self, dlsap_sel, slsap_sel, CONNECT_CMD,
				       irlmp->unconnected_lsaps);

		/* Maybe LSAP was already connected, so try one more time */
		if (!lsap) {
			IRDA_DEBUG(1, "%s(), incoming connection for LSAP already connected\n", __func__);
			lsap = irlmp_find_lsap(self, dlsap_sel, slsap_sel, 0,
					       self->lsaps);
		}
	} else
		lsap = irlmp_find_lsap(self, dlsap_sel, slsap_sel, 0,
				       self->lsaps);

	if (lsap == NULL) {
		IRDA_DEBUG(2, "IrLMP, Sorry, no LSAP for received frame!\n");
		IRDA_DEBUG(2, "%s(), slsap_sel = %02x, dlsap_sel = %02x\n",
			   __func__, slsap_sel, dlsap_sel);
		if (fp[0] & CONTROL_BIT) {
			IRDA_DEBUG(2, "%s(), received control frame %02x\n",
				   __func__, fp[2]);
		} else {
			IRDA_DEBUG(2, "%s(), received data frame\n", __func__);
		}
		return;
	}

	/*
	 *  Check if we received a control frame?
	 */
	if (fp[0] & CONTROL_BIT) {
		switch (fp[2]) {
		case CONNECT_CMD:
			lsap->lap = self;
			irlmp_do_lsap_event(lsap, LM_CONNECT_INDICATION, skb);
			break;
		case CONNECT_CNF:
			irlmp_do_lsap_event(lsap, LM_CONNECT_CONFIRM, skb);
			break;
		case DISCONNECT:
			IRDA_DEBUG(4, "%s(), Disconnect indication!\n",
				   __func__);
			irlmp_do_lsap_event(lsap, LM_DISCONNECT_INDICATION,
					    skb);
			break;
		case ACCESSMODE_CMD:
			IRDA_DEBUG(0, "Access mode cmd not implemented!\n");
			break;
		case ACCESSMODE_CNF:
			IRDA_DEBUG(0, "Access mode cnf not implemented!\n");
			break;
		default:
			IRDA_DEBUG(0, "%s(), Unknown control frame %02x\n",
				   __func__, fp[2]);
			break;
		}
	} else if (unreliable) {
		/* Optimize and bypass the state machine if possible */
		if (lsap->lsap_state == LSAP_DATA_TRANSFER_READY)
			irlmp_udata_indication(lsap, skb);
		else
			irlmp_do_lsap_event(lsap, LM_UDATA_INDICATION, skb);
	} else {
		/* Optimize and bypass the state machine if possible */
		if (lsap->lsap_state == LSAP_DATA_TRANSFER_READY)
			irlmp_data_indication(lsap, skb);
		else
			irlmp_do_lsap_event(lsap, LM_DATA_INDICATION, skb);
	}
}

/*
 * Function irlmp_link_unitdata_indication (self, skb)
 *
 *
 *
 */
#ifdef CONFIG_IRDA_ULTRA
void irlmp_link_unitdata_indication(struct lap_cb *self, struct sk_buff *skb)
{
	struct lsap_cb *lsap;
	__u8   slsap_sel;   /* Source (this) LSAP address */
	__u8   dlsap_sel;   /* Destination LSAP address */
	__u8   pid;         /* Protocol identifier */
	__u8   *fp;
	unsigned long flags;

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

	IRDA_ASSERT(self != NULL, return;);
	IRDA_ASSERT(self->magic == LMP_LAP_MAGIC, return;);
	IRDA_ASSERT(skb->len > 2, return;);

	fp = skb->data;

	/*
	 *  The next statements may be confusing, but we do this so that
	 *  destination LSAP of received frame is source LSAP in our view
	 */
	slsap_sel = fp[0] & LSAP_MASK;
	dlsap_sel = fp[1];
	pid       = fp[2];

	if (pid & 0x80) {
		IRDA_DEBUG(0, "%s(), extension in PID not supp!\n",
			   __func__);
		return;
	}

	/* Check if frame is addressed to the connectionless LSAP */
	if ((slsap_sel != LSAP_CONNLESS) || (dlsap_sel != LSAP_CONNLESS)) {
		IRDA_DEBUG(0, "%s(), dropping frame!\n", __func__);
		return;
	}

	/* Search the connectionless LSAP */
	spin_lock_irqsave(&irlmp->unconnected_lsaps->hb_spinlock, flags);
	lsap = (struct lsap_cb *) hashbin_get_first(irlmp->unconnected_lsaps);
	while (lsap != NULL) {
		/*
		 *  Check if source LSAP and dest LSAP selectors and PID match.
		 */
		if ((lsap->slsap_sel == slsap_sel) &&
		    (lsap->dlsap_sel == dlsap_sel) &&
		    (lsap->pid == pid))
		{
			break;
		}
		lsap = (struct lsap_cb *) hashbin_get_next(irlmp->unconnected_lsaps);
	}
	spin_unlock_irqrestore(&irlmp->unconnected_lsaps->hb_spinlock, flags