patch-2.1.132 linux/net/irda/irlap_frame.c

• Lines: 1421
• Date: Thu Dec 17 09:01:03 1998
• Orig file: v2.1.131/linux/net/irda/irlap_frame.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.131/linux/net/irda/irlap_frame.c linux/net/irda/irlap_frame.c
@@ -0,0 +1,1420 @@
+/*********************************************************************
+ *                
+ * Filename:      irlap_frame.c
+ * Version:       0.3
+ * Description:   Build and transmit IrLAP frames
+ * Status:        Experimental.
+ * Author:        Dag Brattli <dagb@cs.uit.no>
+ * Created at:    Tue Aug 19 10:27:26 1997
+ * Modified at:   Mon Dec 14 14:24:05 1998
+ * Modified by:   Dag Brattli <dagb@cs.uit.no>
+ * 
+ *     Copyright (c) 1998 Dag Brattli <dagb@cs.uit.no>, All Rights Resrved.
+ *     
+ *     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 Tromsų admit liability nor
+ *     provide warranty for any of this software. This material is 
+ *     provided "AS-IS" and at no charge.
+ *
+ ********************************************************************/
+
+#include <linux/config.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+
+#include <linux/skbuff.h>
+#include <linux/if.h>
+#include <linux/if_ether.h>
+#include <linux/netdevice.h>
+#include <net/pkt_sched.h>
+
+#include <net/irda/irda.h>
+#include <net/irda/irda_device.h>
+#include <net/irda/irlap.h>
+#include <net/irda/wrapper.h>
+#include <net/irda/timer.h>
+#include <net/irda/irlap_frame.h>
+#include <net/irda/qos.h>
+
+extern __u8 *irlmp_hint_to_service( __u8 *hint);
+
+/*
+ * Function irlap_insert_mtt (self, skb)
+ *
+ *    Insert minimum turnaround time relevant information into the skb. We 
+ *    need to do this since it's per packet relevant information.
+ *
+ */
+__inline__ void irlap_insert_mtt( struct irlap_cb *self, struct sk_buff *skb)
+{
+	struct irlap_skb_cb *cb;
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+
+	cb = (struct irlap_skb_cb *) skb->cb;
+	
+	cb->mtt = self->mtt_required;
+	
+	/* Reset */
+	self->mtt_required = 0;
+	
+	/* 
+	 * Delay equals negotiated BOFs count plus the number of BOFs to 
+	 * force the negotiated minimum turnaround time 
+	 */
+	cb->xbofs = self->bofs_count+self->xbofs_delay;
+	
+	/* Reset XBOF's delay (used only for getting min turn time) */
+	self->xbofs_delay = 0;
+
+	DEBUG( 4, __FUNCTION__ "(), using %d xbofs\n", cb->xbofs);
+}
+
+/*
+ * Function irlap_send_connect_snrm_cmd (void)
+ *
+ *    Transmits a connect SNRM command frame
+ */
+void irlap_send_snrm_frame( struct irlap_cb *self, struct qos_info *qos) 
+{
+	struct sk_buff *skb;
+	__u8 *frame;
+	int len;
+	int n;
+
+	DEBUG( 4, "irlap_send_snrm_cmd()\n");
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+
+	n = 0;
+
+	/* Allocate frame */
+	skb = dev_alloc_skb( 64);
+	if (skb == NULL) {
+		DEBUG( 0,"irlap_send_snrm_cmd: "
+		       "Could not allocate an sk_buff of length %d\n", 64);
+		return;
+	}
+
+	skb_put( skb, 2); 
+	frame = skb->data;
+
+	/* Insert address field */
+	frame[n] = CMD_FRAME;
+	frame[n++] |= (qos) ? CBROADCAST : self->caddr;
+
+	/* Insert control field */
+ 	frame[n++] = SNRM_CMD | PF_BIT;
+	
+	/*
+	 *  If we are establishing a connection then insert QoS paramerters 
+	 */
+	if (qos) {
+		skb_put( skb, 9); /* 21 left */
+		memcpy( frame+n, &self->saddr, 4); n += 4;
+		memcpy( frame+n, &self->daddr, 4); n += 4;
+
+		frame[n++] = self->caddr;
+				
+		/* skb_put( skb, 21); */
+		len = irda_insert_qos_negotiation_params( qos, frame+n);
+		/* Should not be dangerous to do this afterwards */
+		skb_put( skb, len);
+	}
+	skb->dev = self->netdev;
+	skb->h.raw = skb->data;
+	irlap_insert_mtt( self, skb);
+
+	dev_queue_xmit( skb);
+	self->stats.tx_packets++;
+}
+
+/*
+ * Function irlap_recv_snrm_cmd (skb, info)
+ *
+ *    Received SNRM (Set Normal Response Mode) command frame
+ *
+ */
+static void irlap_recv_snrm_cmd( struct irlap_cb *self, struct sk_buff *skb, 
+				 struct irlap_info *info) 
+{
+	struct snrm_frame *frame;
+
+	DEBUG( 4, __FUNCTION__ "() <%ld>\n", jiffies);
+
+	ASSERT( skb != NULL, return;);
+	ASSERT( info != NULL, return;);
+
+	frame = ( struct snrm_frame *) skb->data;
+
+	/* Copy peer device address */
+	memcpy( &info->daddr, &frame->saddr, 4);
+
+	/* Copy connection address */
+	info->caddr = frame->ncaddr;
+
+	irlap_do_event( self, RECV_SNRM_CMD, skb, info);
+}
+
+/*
+ * Function irlap_send_ua_response_frame (qos)
+ *
+ *    Send UA (Unnumbered Acknowledgement) frame
+ *
+ */
+void irlap_send_ua_response_frame( struct irlap_cb *self, 
+				   struct qos_info *qos)
+{
+	struct sk_buff *skb;
+	__u8 *frame;
+	int n;
+	int len;
+	
+	DEBUG( 4, __FUNCTION__ "() <%ld>\n", jiffies);
+	
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+
+	skb = NULL;
+	n = 0;
+
+	/* Allocate frame */
+	skb =  dev_alloc_skb( 64);
+	if (skb == NULL) {
+		DEBUG( 0, __FUNCTION__
+		       "Could not allocate an sk_buff of length %d\n", 64);
+		return;
+	}
+
+	skb_put( skb, 10);
+	frame = skb->data;
+	
+	/* Build UA response */
+	frame[n++] = self->caddr;
+ 	frame[n++] = UA_RSP | PF_BIT;
+	memcpy( frame+n, &self->saddr, 4); n += 4;
+	memcpy( frame+n, &self->daddr, 4); n += 4;
+	
+	/* Should we send QoS negotiation parameters? */
+	if ( qos) {
+		len = irda_insert_qos_negotiation_params( qos, frame+n);
+		skb_put( skb, len);
+	}
+
+	skb->dev = self->netdev;
+	skb->h.raw = skb->data;
+	irlap_insert_mtt( self, skb);
+
+	dev_queue_xmit( skb);
+	self->stats.tx_packets++;
+}
+
+
+/*
+ * Function irlap_send_dm_frame (void)
+ *
+ *    Send disconnected mode (DM) frame
+ *
+ */
+void irlap_send_dm_frame( struct irlap_cb *self)
+{
+	struct sk_buff *skb = NULL;
+	__u8 *frame;
+	
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+
+	skb =  dev_alloc_skb( 32);
+	if (skb == NULL) {
+		DEBUG( 0,"irlap_send_disc_frame: "
+		       "Could not allocate an sk_buff of length %d\n", 64);
+		return;
+	}
+
+	skb_put( skb, 2);
+	frame = skb->data;
+	
+	if ( self->state == LAP_NDM)
+		frame[0] = CBROADCAST;
+	else
+		frame[0] = self->caddr;
+
+	frame[1] = DM_RSP | PF_BIT;
+	
+	skb->dev = self->netdev;
+	skb->h.raw = skb->data;
+	irlap_insert_mtt( self, skb);
+
+	dev_queue_xmit( skb);
+	self->stats.tx_packets++;
+}
+
+/*
+ * Function irlap_send_disc_frame (void)
+ *
+ *    Send disconnect (DISC) frame
+ *
+ */
+void irlap_send_disc_frame( struct irlap_cb *self) 
+{
+	struct sk_buff *skb = NULL;
+	__u8 *frame;
+	
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+
+	skb =  dev_alloc_skb( 32);
+	if (skb == NULL) {
+		DEBUG( 0,"irlap_send_disc_frame: "
+		       "Could not allocate an sk_buff of length %d\n", 64);
+		return;
+	}
+
+	skb_put( skb, 2);
+	frame = skb->data;
+	
+	frame[0] = self->caddr | CMD_FRAME;
+	frame[1] = DISC_CMD | PF_BIT;
+	
+	skb->dev = self->netdev;
+	skb->h.raw = skb->data;
+	irlap_insert_mtt( self, skb);
+
+	dev_queue_xmit( skb);
+	self->stats.tx_packets++;
+}
+
+/*
+ * Function irlap_send_discovery_xid_frame (S, s, command)
+ *
+ *    Build and transmit a XID (eXchange station IDentifier) discovery
+ *    frame. 
+ */
+void irlap_send_discovery_xid_frame( struct irlap_cb *self, int S, __u8 s, 
+				     __u8 command, DISCOVERY *discovery) 
+{
+	struct sk_buff *skb = NULL;
+	struct xid_frame *frame;
+	__u32 bcast = BROADCAST;
+
+ 	DEBUG( 4, __FUNCTION__ "(), s=%d, S=%d, command=%d\n", s, S, command);
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( discovery != NULL, return;);
+
+	skb =  dev_alloc_skb( 64);
+	if (skb == NULL) {
+		DEBUG( 0,"irlap_send_discovery_xid_frame: "
+		       "Could not allocate an sk_buff of length %d\n", 64);
+		return;
+	}
+
+	skb_put( skb, 14);
+	frame = ( struct xid_frame *) skb->data;
+
+	if ( command) {
+		frame->caddr = CBROADCAST | CMD_FRAME;
+		frame->control =  XID_CMD | PF_BIT;
+	} else {
+		frame->caddr = CBROADCAST;
+		frame->control =  XID_RSP | PF_BIT;
+	}
+	frame->ident = XID_FORMAT;
+
+	memcpy( &frame->saddr, &self->saddr, 4);
+
+	if ( command)
+		memcpy( &frame->daddr, &bcast, 4);
+	else
+		memcpy( &frame->daddr, &self->daddr, 4);	
+	
+	switch( S) {
+	case 1:
+		frame->flags = 0x00;
+		break;
+	case 6:
+		frame->flags = 0x01;
+		break;
+	case 8:
+		frame->flags = 0x02;
+		break;
+	case 16:
+		frame->flags = 0x03;
+		break;
+	default:
+		frame->flags = 0x02;
+		break;
+	}
+
+	frame->slotnr = s; 
+	frame->version = 0x00;
+
+	/*  
+	 *  Provide info for final slot only in commands, and for all
+	 *  responses. Send the second byte of the hint only if the
+	 *  EXTENSION bit is set in the first byte.
+	 */
+	if ( !command || ( frame->slotnr == 0xff)) {
+		int i;
+
+		if( discovery->hint[0] & HINT_EXTENSION)
+			skb_put( skb, 3+discovery->info_len);
+		else
+			skb_put( skb, 2+discovery->info_len);
+		
+		i = 0;
+		frame->discovery_info[i++] = discovery->hint[0];
+		if( discovery->hint[0] & HINT_EXTENSION)
+			frame->discovery_info[i++] = discovery->hint[1];
+		
+		frame->discovery_info[i++] = discovery->charset;
+
+		ASSERT( discovery->info_len < 30, return;);
+
+		memcpy( &frame->discovery_info[i++], discovery->info, 
+			discovery->info_len);
+
+	} 
+
+	ASSERT( self->netdev != NULL, return;);
+
+	skb->dev = self->netdev;
+	skb->h.raw = skb->data;
+	irlap_insert_mtt( self, skb);
+
+	dev_queue_xmit( skb);
+	self->stats.tx_packets++;
+}
+
+/*
+ * Function irlap_recv_discovery_xid_rsp (skb, info)
+ *
+ *    Received a XID discovery response
+ *
+ */
+static void irlap_recv_discovery_xid_rsp( struct irlap_cb *self, 
+					  struct sk_buff *skb, 
+					  struct irlap_info *info) 
+{
+	struct xid_frame *xid;
+	DISCOVERY *discovery = NULL;
+	char *text;
+
+	DEBUG( 4, __FUNCTION__ "()\n");
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+	ASSERT( info != NULL, return;);
+
+	if (( discovery = kmalloc( sizeof( DISCOVERY), GFP_ATOMIC)) == NULL) {
+		DEBUG( 0, __FUNCTION__ "(), kmalloc failed!\n");
+		return;
+	}
+	memset( discovery, 0, sizeof( DISCOVERY));
+
+	xid = (struct xid_frame *) skb->data;
+
+	/* 
+	 *  Copy peer device address and set the source address
+	 */
+	memcpy( &info->daddr, &xid->saddr, 4);
+	discovery->daddr = info->daddr;
+	discovery->saddr = self->saddr;
+
+	DEBUG( 4, __FUNCTION__ "(), daddr=%08x\n", discovery->daddr);
+
+	/* Get info returned from peer */
+	discovery->hint[0] = xid->discovery_info[0];
+	if ( xid->discovery_info[0] & HINT_EXTENSION) {
+		DEBUG( 4, "EXTENSION\n");
+		discovery->hint[1] = xid->discovery_info[1];
+		discovery->charset = xid->discovery_info[2];
+		text = (char *) &xid->discovery_info[3];
+	} else {
+		discovery->hint[1] = 0;
+		discovery->charset = xid->discovery_info[1];
+		text = (char *) &xid->discovery_info[2];
+	}
+	/* 
+	 *  Terminate string, should be safe since this is where the 
+	 *  FCS bytes resides.
+	 */
+	skb->data[skb->len] = '\0'; 
+	strcpy( discovery->info, text);
+
+	info->discovery = discovery;
+
+	irlap_do_event( self, RECV_DISCOVERY_XID_RSP, skb, info);
+}
+
+/*
+ * Function irlap_recv_discovery_xid_cmd (skb, info)
+ *
+ *    Received a XID discovery command
+ *
+ */
+static void irlap_recv_discovery_xid_cmd( struct irlap_cb *self, 
+					  struct sk_buff *skb, 
+					  struct irlap_info *info) 
+{
+	struct xid_frame *xid;
+	DISCOVERY *discovery = NULL;
+	char *text;
+
+	DEBUG( 4, __FUNCTION__ "()\n");
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+	ASSERT( info != NULL, return;);
+
+	xid = (struct xid_frame *) skb->data;
+	
+	/* Copy peer device address */
+	memcpy( &info->daddr, &xid->saddr, 4);
+
+	switch ( xid->flags & 0x03) {
+	case 0x00:
+		info->S = 1;
+		break;
+	case 0x01:
+		info->S = 6;
+		break;
+	case 0x02:
+		info->S = 8;
+		break;
+	case 0x03:
+		info->S = 16;
+		break;
+	default:
+		/* Error!! */
+		return;
+	}
+	info->s = xid->slotnr;
+	
+	/* 
+	 *  Check if last frame 
+	 */
+	if ( info->s == 0xff) {
+		/*
+		 *  We now have some discovery info to deliver!
+		 */
+		discovery = kmalloc( sizeof( DISCOVERY), GFP_ATOMIC);
+		if ( !discovery) {
+			DEBUG( 0, __FUNCTION__ "(), kmalloc failed!\n");
+			return;
+		}
+		discovery->daddr = info->daddr;
+		discovery->saddr = self->saddr;
+
+		DEBUG( 4, __FUNCTION__ "(), daddr=%08x\n", 
+		       discovery->daddr);
+
+		discovery->hint[0] = xid->discovery_info[0];
+		if ( xid->discovery_info[0] & HINT_EXTENSION) {
+			DEBUG( 4, "EXTENSION\n");
+			discovery->hint[1] = xid->discovery_info[1];
+			discovery->charset = xid->discovery_info[2];
+			text = (char *) &xid->discovery_info[3];
+		} else {
+			discovery->hint[1] = 0;
+			discovery->charset = xid->discovery_info[1];
+			text = (char *) &xid->discovery_info[2];
+		}
+		/* 
+		 *  Terminate string, should be safe since this is where the 
+		 *  FCS bytes resides.
+		 */
+		skb->data[skb->len] = '\0'; 
+		strcpy( discovery->info, text);
+
+		info->discovery = discovery;
+	} else
+		info->discovery = NULL;
+	
+	DEBUG( 4, __FUNCTION__"(), s=%d, S=%d <%ld>\n", 
+	       info->s, info->S, jiffies); 
+
+	irlap_do_event( self, RECV_DISCOVERY_XID_CMD, skb, info);
+}
+
+/*
+ * Function irlap_send_rr_frame (self, command)
+ *
+ *    Build and transmit RR (Receive Ready) frame. Notice that it is currently
+ *    only possible to send RR frames with the poll bit set.
+ */
+void irlap_send_rr_frame( struct irlap_cb *self, int command) 
+{
+	struct sk_buff *skb = NULL;
+	__u8 *frame;
+	
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+
+#ifdef CONFIG_IRDA_RECYCLE_RR
+	if ( self->recycle_rr_skb) {
+		DEBUG( 4, __FUNCTION__ "(), recycling skb!\n");
+		skb = self->recycle_rr_skb;
+		skb->stamp.tv_sec = 0;
+		self->recycle_rr_skb = NULL;
+	}
+#endif      
+	if ( !skb) {
+		skb = dev_alloc_skb( 32);
+		if (skb == NULL) {
+			printk( KERN_WARNING "irlap_send_rr_frame: "
+				"Could not allocate an skb of length %d\n", 32);
+			return;
+		}
+		skb_put( skb, 2);
+	}
+	ASSERT( skb->len == 2, return;);
+
+	frame = skb->data;
+	
+	frame[0] = self->caddr;
+	frame[0] |= (command) ? CMD_FRAME : 0;
+
+	frame[1] = RR | PF_BIT | (self->vr << 5);
+
+   	DEBUG( 4, __FUNCTION__ "(), vr=%d, %ld\n", self->vr, jiffies); 
+
+	skb->dev = self->netdev;
+	skb->h.raw = skb->data;
+	irlap_insert_mtt( self, skb);
+
+	dev_queue_xmit( skb);
+	self->stats.tx_packets++;
+}
+
+/*
+ * Function irlap_recv_rr_frame (skb, info)
+ *
+ *    Received RR (Receive Ready) frame from peer station
+ *
+ */
+static void irlap_recv_rr_frame( struct irlap_cb *self, struct sk_buff *skb, 
+				 struct irlap_info *info, int command)
+{
+	__u8 *frame;
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+
+	frame = skb->data;
+	info->nr = frame[1] >> 5;
+
+	DEBUG( 4, __FUNCTION__ "(), nr=%d, %ld\n", info->nr, jiffies);
+
+	/*
+	 *  Make sure the state-machine is in the right state for receiving, 
+	 *  if not, then we just discard the received frame for now!
+	 *  TODO: check if we should queue this frame, or make tty tell that
+	 *  it is receiving frames until the frame is delivered instead of
+	 *  until it is outside a frame.
+	 */
+#if 0
+	if (( self->state != LAP_NRM_P) && ( self->state != LAP_NRM_S)) {
+		DEBUG( 0, __FUNCTION__ "(), Wrong state, dropping frame!\n");
+		dev_kfree_skb( skb);
+		return;
+	}
+#endif
+
+#ifdef CONFIG_IRDA_RECYCLE_RR
+	/* Only recycle one RR frame */
+	if ( self->recycle_rr_skb == NULL) {
+
+		/* Keep this skb, so it can be reused */
+		self->recycle_rr_skb = skb;
+
+		/*  
+		 *  Set skb to NULL, so that the state machine will not 
+		 *  deallocate it.
+		 */
+		skb = NULL;  
+	}
+#endif
+	/* Check if this is a command or a response frame */
+	if ( command)
+		irlap_do_event( self, RECV_RR_CMD, skb, info);
+	else
+		irlap_do_event( self, RECV_RR_RSP, skb, info);
+}
+
+/*
+ * Function irlap_send_rr_frame ()
+ *
+ *    Build and transmit RR (Receive Ready) frame
+ */
+void irlap_send_frmr_frame( struct irlap_cb *self, int command)
+{
+	struct sk_buff *skb = NULL;
+	__u8 *frame;
+	
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+
+	skb = dev_alloc_skb( 32);
+	if (skb == NULL) {
+		printk( KERN_WARNING "irlap_send_frmr_frame: "
+			"Could not allocate an sk_buff of length %d\n", 32);
+		return;
+	}
+
+	skb_put( skb, 2);
+	frame = skb->data;
+	
+	frame[0] = self->caddr;
+	frame[0] |= (command) ? CMD_FRAME : 0;
+
+	frame[1]  = (self->vs << 1);
+	frame[1] |= PF_BIT;
+	frame[1] |= (self->vr << 5);
+
+	frame[2] = 0;
+
+   	DEBUG( 4, __FUNCTION__ "(), vr=%d, %ld\n",self->vr, jiffies); 
+
+	skb->dev = self->netdev;
+	skb->h.raw = skb->data;
+	irlap_insert_mtt( self, skb);
+
+	dev_queue_xmit( skb);
+	self->stats.tx_packets++;
+}
+
+/*
+ * Function irlap_recv_rnr_frame (self, skb, info)
+ *
+ *    Received RNR (Receive Not Ready) frame from peer station
+ *
+ */
+static void irlap_recv_rnr_frame( struct irlap_cb *self, struct sk_buff *skb, 
+				  struct irlap_info *info) 
+{
+	__u8 *frame;
+
+	ASSERT( skb != NULL, return;);
+	ASSERT( info != NULL, return;);
+
+	frame = skb->data;
+	info->nr = frame[1] >> 5;
+
+	DEBUG( 4, __FUNCTION__ "(), nr=%d, %ld\n", info->nr, jiffies);
+
+	irlap_do_event( self, RECV_RNR_FRAME, skb, info);
+}
+
+/*
+ * Function irlap_recv_ua_frame (skb, frame)
+ *
+ *    Received UA (Unnumbered Acknowledgement) frame
+ *
+ */
+static void irlap_recv_ua_frame( struct irlap_cb *self, struct sk_buff *skb, 
+				 struct irlap_info *info) 
+{
+ 	DEBUG( 4, __FUNCTION__ "()\n"); 
+
+	ASSERT( skb != NULL, return;);
+	ASSERT( info != NULL, return;);
+
+	irlap_do_event( self, RECV_UA_RSP, skb, info);
+}
+
+/*
+ * Function irlap_send_data_primary(self, skb)
+ *
+ *    
+ *
+ */
+void irlap_send_data_primary( struct irlap_cb *self, struct sk_buff *skb)
+{
+	struct sk_buff *tx_skb;
+
+	DEBUG( 4, __FUNCTION__ "()\n");
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+
+	/* Initialize variables */
+	tx_skb = NULL;
+
+	if ( skb->data[1] == I_FRAME) {
+
+		/*  
+		 *  Insert frame sequence number (Vs) in control field before
+		 *  inserting into transmit window queue.
+		 */
+		skb->data[1] = I_FRAME | (self->vs << 1);
+		
+		/* * Copy buffer */
+		tx_skb = skb_clone( skb, GFP_ATOMIC);
+		/* tx_skb = skb_copy( skb, GFP_ATOMIC);  */
+		if ( tx_skb == NULL) {
+			dev_kfree_skb( skb);
+			return;
+		}
+		
+		/*
+		 *  make sure the skb->sk accounting of memory usage is sane
+		 */
+		if (skb->sk != NULL)
+			skb_set_owner_w( tx_skb, skb->sk);
+		
+		/* 
+		 *  Insert frame in store, in case of retransmissions 
+		 */
+		skb_queue_tail( &self->wx_list, skb);
+		
+		self->vs = (self->vs + 1) % 8;
+		self->ack_required = FALSE;		
+		self->window -= 1;
+
+		irlap_send_i_frame( self, tx_skb, CMD_FRAME);
+	} else {
+		DEBUG( 4, __FUNCTION__ "(), sending unreliable frame\n");
+		irlap_send_ui_frame( self, skb, CMD_FRAME);
+		self->window -= 1;
+	}
+}
+/*
+ * Function irlap_send_data_primary_poll ( self, skb)
+ *
+ *    Send I(nformation) frame as primary with poll bit set
+ */
+void irlap_send_data_primary_poll( struct irlap_cb *self, struct sk_buff *skb) 
+{
+	struct sk_buff *tx_skb;
+
+	DEBUG( 4, __FUNCTION__ "()\n");
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+
+	IS_SKB( skb, return;);
+
+	/* Initialize variables */
+	tx_skb = NULL;
+
+	/* Is this reliable or unreliable data? */
+	if ( skb->data[1] == I_FRAME) {
+		
+		/*  
+		 *  Insert frame sequence number (Vs) in control field before
+		 *  inserting into transmit window queue.
+		 */
+		skb->data[1] = I_FRAME | (self->vs << 1);
+		
+		/* Copy buffer */
+		tx_skb = skb_clone( skb, GFP_ATOMIC);
+		/* tx_skb = skb_copy( skb, GFP_ATOMIC);  */
+		if ( tx_skb == NULL) {
+			dev_kfree_skb( skb);
+			return;
+		}
+		
+		/*
+		 *  make sure the skb->sk accounting of memory usage is sane
+		 */
+		if (skb->sk != NULL)
+			skb_set_owner_w( tx_skb, skb->sk);
+		
+		/* 
+		 *  Insert frame in store, in case of retransmissions 
+		 */
+		skb_queue_tail( &self->wx_list, skb);
+		
+		/*  
+		 *  Set poll bit if necessary. We do this to the copied
+		 *  skb, since retransmitted need to set or clear the poll
+		 *  bit depending on when * they are sent.  
+		 */
+		/* Stop P timer */
+		del_timer( &self->poll_timer);
+		
+		tx_skb->data[1] |= PF_BIT;
+		
+		self->vs = (self->vs + 1) % 8;
+		self->ack_required = FALSE;
+		self->window = self->window_size;
+
+		irlap_start_final_timer( self, self->final_timeout);
+
+		irlap_send_i_frame( self, tx_skb, CMD_FRAME);
+	} else {
+		DEBUG( 4, __FUNCTION__ "(), sending unreliable frame\n");
+
+		del_timer( &self->poll_timer);
+
+		if ( self->ack_required) {
+			irlap_send_ui_frame( self, skb, CMD_FRAME);
+			irlap_send_rr_frame( self, CMD_FRAME);
+			self->ack_required = FALSE;
+		} else {
+			skb->data[1] |= PF_BIT;
+			irlap_send_ui_frame( self, skb, CMD_FRAME);
+		}
+		self->window = self->window_size;
+		irlap_start_final_timer( self, self->final_timeout);
+	}
+}
+
+/*
+ * Function irlap_send_data_secondary_final (self, skb)
+ *
+ *    Send I(nformation) frame as secondary with final bit set
+ *
+ */
+void irlap_send_data_secondary_final( struct irlap_cb *self, 
+				      struct sk_buff *skb) 
+{
+	struct sk_buff *tx_skb = NULL;
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+
+	IS_SKB( skb,return;);
+
+	/* Is this reliable or unreliable data? */
+	if ( skb->data[1] == I_FRAME) {
+
+		/*  
+		 *  Insert frame sequence number (Vs) in control field before
+		 *  inserting into transmit window queue.
+		 */
+		skb->data[1] = I_FRAME | (self->vs << 1);
+		
+		tx_skb = skb_clone( skb, GFP_ATOMIC);
+		/* tx_skb = skb_copy( skb, GFP_ATOMIC); */
+		if ( tx_skb == NULL) {
+			dev_kfree_skb( skb);
+			return;
+		}		
+
+		if (skb->sk != NULL)
+			skb_set_owner_w( tx_skb, skb->sk);
+		
+		/* Insert frame in store */
+		skb_queue_tail( &self->wx_list, skb);
+		
+		tx_skb->data[1] |= PF_BIT;
+		
+		self->vs = (self->vs + 1) % 8; 
+		self->window = self->window_size;
+		self->ack_required = FALSE;
+		
+		irlap_start_wd_timer( self, self->wd_timeout);
+
+		irlap_send_i_frame( self, tx_skb, RSP_FRAME); 
+	} else {
+		if ( self->ack_required) {
+			irlap_send_ui_frame( self, skb, RSP_FRAME);
+			irlap_send_rr_frame( self, RSP_FRAME);
+			self->ack_required = FALSE;
+		} else {
+			skb->data[1] |= PF_BIT;
+			irlap_send_ui_frame( self, skb, RSP_FRAME);
+		}
+		self->window = self->window_size;
+
+		irlap_start_wd_timer( self, self->wd_timeout);
+	}
+}
+
+/*
+ * Function irlap_send_data_secondary (self, skb)
+ *
+ *    Send I(nformation) frame as secondary without final bit set
+ *
+ */
+void irlap_send_data_secondary( struct irlap_cb *self, struct sk_buff *skb) 
+{
+	struct sk_buff *tx_skb = NULL;
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+
+	IS_SKB( skb, return;);
+
+	/* Is this reliable or unreliable data? */
+	if ( skb->data[1] == I_FRAME) {
+		
+		/*  
+		 *  Insert frame sequence number (Vs) in control field before
+		 *  inserting into transmit window queue.
+		 */
+		skb->data[1] = I_FRAME | (self->vs << 1);
+		
+		tx_skb = skb_clone( skb, GFP_ATOMIC);
+		/* tx_skb = skb_copy( skb, GFP_ATOMIC); */
+		if ( tx_skb == NULL) {
+			dev_kfree_skb( skb);
+			return;
+		}		
+		
+		if (skb->sk != NULL)
+			skb_set_owner_w( tx_skb, skb->sk);
+		
+		/* Insert frame in store */
+		skb_queue_tail( &self->wx_list, skb);
+		
+		self->vs = (self->vs + 1) % 8;
+		self->ack_required = FALSE;		
+		self->window -= 1;
+
+		irlap_send_i_frame( self, tx_skb, RSP_FRAME); 
+	} else {
+		irlap_send_ui_frame( self, skb, RSP_FRAME);
+		self->window -= 1;
+	}
+}
+
+/*
+ * Function irlap_resend_rejected_frames (nr)
+ *
+ *    Resend frames which has not been acknowledged. TODO: check that the 
+ *    traversal of the list is atomic, i.e that no-one tries to insert or
+ *    remove frames from the list while we travers it!
+ * 
+ *    FIXME: It is not safe to traverse a this list without locking it!
+ */
+void irlap_resend_rejected_frames( struct irlap_cb *self, int command) 
+{
+	struct sk_buff *tx_skb;
+	struct sk_buff *skb;
+	int count;
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+
+	DEBUG( 4, __FUNCTION__ "(), retry_count=%d\n",
+	       self->retry_count);
+
+	/* Initialize variables */
+	skb = tx_skb = NULL;
+
+	/* 
+	 *  Resend all unacknowledged frames 
+	 */
+	count = skb_queue_len( &self->wx_list);
+	skb = skb_peek( &self->wx_list);
+	while ( skb != NULL) {
+		irlap_wait_min_turn_around( self, &self->qos_tx);
+
+		tx_skb = skb_clone( skb, GFP_ATOMIC);
+		/* tx_skb = skb_copy( skb, GFP_ATOMIC); */
+		if ( tx_skb == NULL) {
+			/* Unlink tx_skb from list */
+			tx_skb->next = tx_skb->prev = NULL;
+			tx_skb->list = NULL;
+		
+			dev_kfree_skb( skb);
+			return;	
+		}
+		/* Unlink tx_skb from list */
+		tx_skb->next = tx_skb->prev = NULL;
+		tx_skb->list = NULL;
+
+		/*
+		 *  make sure the skb->sk accounting of memory usage is sane
+		 */
+		if ( skb->sk != NULL)
+			skb_set_owner_w( tx_skb, skb->sk);
+
+		/* Clear old Nr field + poll bit */
+		tx_skb->data[1] &= 0x0f;
+
+		/* 
+		 *  Set poll bit on the last frame retransmitted
+		 */
+	 	if ( count-- == 1) 
+	 		tx_skb->data[1] |= PF_BIT; /* Set p/f bit */
+		else
+			tx_skb->data[1] &= ~PF_BIT; /* Clear p/f bit */
+	      	
+		irlap_send_i_frame( self, tx_skb, command);
+
+		/* 
+		 *  If our skb is the last buffer in the list, then
+		 *  we are finished, if not, move to the next sk-buffer
+		 */
+		if ( skb == skb_peek_tail( &self->wx_list))
+			skb = NULL;
+		else
+			skb = skb->next;
+	}
+	/* 
+	 *  We can now fill the window with additinal data frames
+	 */
+	return; /* Skip this for now, DB */
+
+	while ( skb_queue_len( &self->tx_list) > 0) {
+		
+		DEBUG( 0, "irlap_resend_rejected_frames: "
+		       "sending additional frames!\n");
+		if (( skb_queue_len( &self->tx_list) > 0) && 
+		    ( self->window > 0)) {
+			skb = skb_dequeue( &self->tx_list); 
+			ASSERT( skb != NULL, return;);
+
+			/*
+			 *  If send window > 1 then send frame with pf 
+			 *  bit cleared
+			 */ 
+			if (( self->window > 1) && 
+			    skb_queue_len( &self->tx_list) > 0) 
+			{
+				irlap_send_data_primary( self, skb);
+			} else {
+				irlap_send_data_primary_poll( self, skb);
+			}
+		}
+	}
+}
+
+/*
+ * Function irlap_send_ui_frame (self, skb, command)
+ *
+ *    Contruct and transmit an Unnumbered Information (UI) frame
+ *
+ */
+void irlap_send_ui_frame( struct irlap_cb *self, struct sk_buff *skb, 
+			  int command) 
+{
+	__u8  *frame;
+
+	DEBUG( 4, __FUNCTION__ "()\n");
+	
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+	
+	frame = skb->data;
+	
+	/* Insert connection address */
+	frame[0] = self->caddr;
+	frame[0] |= (command) ? CMD_FRAME : 0;
+
+	skb->dev = self->netdev;
+	skb->h.raw = skb->data;
+	irlap_insert_mtt( self, skb);
+
+	dev_queue_xmit( skb);
+	self->stats.tx_packets++;
+}
+
+/*
+ * Function irlap_send_i_frame (skb)
+ *
+ *    Contruct and transmit Information (I) frame
+ */
+void irlap_send_i_frame( struct irlap_cb *self, struct sk_buff *skb, 
+			 int command) 
+{
+	__u8  *frame;
+	
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+
+	frame = skb->data;
+	
+	/* Insert connection address */
+	frame[0] = self->caddr;
+	frame[0] |= (command) ? CMD_FRAME : 0;
+	
+	/* Insert next to receive (Vr) */
+	frame[1] |= (self->vr << 5);  /* insert nr */
+
+#if 0	
+	{
+		int vr, vs, pf;
+		
+		/* Chech contents of various fields */
+		vr = frame[1] >> 5;
+		vs = (frame[1] >> 1) & 0x07;
+		pf = (frame[1] >> 4) & 0x01;
+		
+		DEBUG( 4, __FUNCTION__ "(), vs=%d, vr=%d, p=%d, %ld\n", 
+		       vs, vr, pf, jiffies);
+	}
+#endif	
+	skb->dev = self->netdev;
+	skb->h.raw = skb->data;
+	irlap_insert_mtt( self, skb);
+
+	dev_queue_xmit( skb);
+	self->stats.tx_packets++;
+}
+
+/*
+ * Function irlap_recv_i_frame (skb, frame)
+ *
+ *    Receive and parse an I (Information) frame
+ * 
+ */
+static void irlap_recv_i_frame( struct irlap_cb *self, struct sk_buff *skb, 
+				struct irlap_info *info, int command) 
+{
+	__u8 *frame;
+
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+
+	frame = skb->data;
+
+	info->nr = frame[1] >> 5;          /* Next to receive */
+	info->pf = frame[1] & PF_BIT;      /* Final bit */
+	info->ns = (frame[1] >> 1) & 0x07; /* Next to send */
+
+ 	DEBUG( 4, __FUNCTION__"(), ns=%d, nr=%d, pf=%d, %ld\n", 
+	       info->ns, info->nr, info->pf>>4, jiffies); 
+
+	/*
+	 *  Make sure the state-machine is in the right state for receiving, 
+	 *  if not, then we just discard the received frame for now!
+	 *  TODO: check if we should queue this frame, or make tty tell that
+	 *  it is receiving frames until the frame is delivered instead of
+	 *  until it is outside a frame.
+	 */
+	if (( self->state != LAP_NRM_P) && ( self->state != LAP_NRM_S)) {
+		DEBUG( 0, __FUNCTION__ "(), Wrong state, dropping frame!\n");
+		dev_kfree_skb( skb);
+		return;
+	}
+
+	/* Check if this is a command or a response frame */
+	if ( command)
+		irlap_do_event( self, RECV_I_CMD, skb, info);
+	else
+		irlap_do_event( self, RECV_I_RSP, skb, info);
+}
+
+/*
+ * Function irlap_recv_ui_frame (self, skb, info)
+ *
+ *    Receive and parse an Unnumbered Information (UI) frame
+ *
+ */
+static void irlap_recv_ui_frame( struct irlap_cb *self, struct sk_buff *skb, 
+				 struct irlap_info *info)
+{
+	__u8 *frame;
+
+	DEBUG( 4, __FUNCTION__ "()\n");
+
+	frame = skb->data;
+
+	info->pf = frame[1] & PF_BIT;      /* Final bit */
+
+	irlap_do_event( self, RECV_UI_FRAME, skb, info);
+}
+
+/*
+ * Function irlap_recv_frmr_frame (skb, frame)
+ *
+ *    Received Frame Reject response.
+ *
+ */
+static void irlap_recv_frmr_frame( struct irlap_cb *self, struct sk_buff *skb, 
+				   struct irlap_info *info) 
+{
+	__u8 *frame;
+	int w, x, y, z;
+
+	DEBUG( 0, __FUNCTION__ "()\n");
+	
+	ASSERT( self != NULL, return;);
+	ASSERT( self->magic == LAP_MAGIC, return;);
+	ASSERT( skb != NULL, return;);
+	ASSERT( info != NULL, return;);
+	
+	frame = skb->data;
+
+	info->nr = frame[2] >> 5;          /* Next to receive */
+	info->pf = frame[2] & PF_BIT;        /* Final bit */
+	info->ns = (frame[2] >> 1) & 0x07; /* Next to send */
+
+	w = frame[3] & 0x01;
+	x = frame[3] & 0x02;
+	y = frame[3] & 0x04;
+	z = frame[3] & 0x08;
+	
+	if ( w) {
+		DEBUG( 0, "Rejected control field is undefined or not "
+		       "implemented.\n");
+	} 
+	if ( x) {
+		DEBUG( 0, "Rejected control field was invalid because it "
+		       "contained a non permitted I field.\n");
+	}
+	if ( y) {
+		DEBUG( 0, "Received I field exceeded the maximum negotiated "
+		       "for the existing connection or exceeded the maximum "
+		       "this station supports if no connection exists.\n");
+	}
+	if ( z) {
+		DEBUG( 0, "Rejected control field control field contained an "
+		       "invalid Nr count.\n");
+	}
+	irlap_do_event( self, RECV_FRMR_RSP, skb, info);
+}
+
+/*
+ * Function irlap_input (skb)
+ *
+ *  Called when a frame is received. Dispatches the right receive function 
+ *  for processing of the frame.
+ */
+int irlap_input( struct sk_buff *skb, struct device *netdev, 
+		 struct packet_type *ptype)
+{
+	struct irlap_info info;
+	struct irlap_cb *self;
+	struct irda_device *idev;
+	__u8 *frame;
+	int i, command;
+	__u8 control;
+	
+	idev = ( struct irda_device *) netdev->priv;
+
+	ASSERT( idev != NULL, return -1;);
+	self = idev->irlap;
+
+	ASSERT( self != NULL, return -1;);
+	ASSERT( self->magic == LAP_MAGIC, return -1;);
+	ASSERT(( skb != NULL) && (skb->len > 1), return -1;);
+	
+	frame = skb->data;
+
+	command    = frame[0] & CMD_FRAME;
+	info.caddr = frame[0] & CBROADCAST;
+	
+	info.pf      = frame[1] &  PF_BIT;
+	info.control = frame[1] & ~PF_BIT; /* Mask away poll/final bit */
+
+	control = info.control;
+
+	/* 
+	 *  First check if this frame addressed to us 
+	 */
+	if (( info.caddr != self->caddr) && ( info.caddr != CBROADCAST)) {
+
+		DEBUG( 0, __FUNCTION__ "(), Received frame is not for us!\n");
+		for(i=0; i<(skb->len < 15?skb->len:15);i++) {
+ 			printk( "%02x ", frame[i]);
+		}
+ 		printk("\n"); 
+		
+		dev_kfree_skb( skb);
+
+		return 0;
+	}
+	/*  
+	 *  Optimize for the common case and check if the frame is an
+	 *  I(nformation) frame. Only I-frames have bit 0 set to 0
+	 */
+	if( ~control & 0x01) {
+		irlap_recv_i_frame( self, skb, &info, command);
+		self->stats.rx_packets++;
+		return 0;
+	}
+	/*
+	 *  We now check is the frame is an S(upervisory) frame. Only 
+	 *  S-frames have bit 0 set to 1 and bit 1 set to 0
+	 */
+	if ( ~control & 0x02) {
+		/* 
+		 *  Received S(upervisory) frame, check which frame type it is
+		 *  only the first nibble is of interest
+		 */
+		switch( control & 0x0f) {
+		case RR:
+			irlap_recv_rr_frame( self, skb, &info, command);
+			self->stats.rx_packets++;
+			break;
+		case RNR:
+			DEBUG( 3, "*** RNR frame received! pf = %d ***\n", 
+			       info.pf >> 4);
+			irlap_recv_rnr_frame( self, skb, &info);
+			self->stats.rx_packets++;
+			break;
+		case REJ:
+			DEBUG( 0, "*** REJ frame received! ***\n");
+			break;
+		case SREJ:
+			DEBUG( 0, "*** SREJ frame received! ***\n");
+			break;
+		default:
+			DEBUG( 0, "Unknown S frame %02x received!\n", 
+			       info.control);
+			break;
+		}
+		return 0;
+	}
+	/* 
+	 *  This must be a C(ontrol) frame 
+	 */
+	switch( control) {
+	case XID_RSP:
+		DEBUG( 4, "XID rsp frame received!\n");
+		irlap_recv_discovery_xid_rsp( self, skb, &info);
+		break;
+	case XID_CMD:
+		DEBUG( 4, "XID cmd frame received!\n");
+		irlap_recv_discovery_xid_cmd( self, skb, &info);
+		break;
+	case SNRM_CMD:
+		DEBUG( 4, "SNRM frame received!\n"); 
+		irlap_recv_snrm_cmd( self, skb, &info);
+		break;
+	case DM_RSP:
+		DEBUG( 0, "DM rsp frame received!\n");
+		irlap_next_state( self, LAP_NDM);
+		break;
+	case DISC_CMD:
+		DEBUG( 0, "DISC cmd frame received!\n");
+		irlap_do_event( self, RECV_DISC_FRAME, skb, &info);
+		break;
+	case TEST_CMD:
+		DEBUG( 0, "Test frame received!\n");
+		dev_kfree_skb( skb);
+		break;
+	case UA_RSP:
+		DEBUG( 4, "UA rsp frame received!\n");
+		irlap_recv_ua_frame( self, skb, &info);
+		break;
+	case FRMR_RSP:
+		DEBUG( 4, "FRMR_RSP recevied!\n");
+		irlap_recv_frmr_frame( self, skb, &info);
+		break;
+	case UI_FRAME:
+		DEBUG( 4, "UI-frame received!\n");
+		irlap_recv_ui_frame( self, skb, &info);
+		break;
+	default:
+		DEBUG( 0, "Unknown frame %02x received!\n", info.control);
+		dev_kfree_skb( skb); 
+		break;
+	}
+	self->stats.rx_packets++;
+
+	return 0;
+}