diff --git a/net/lapb/lapb_in.c b/net/lapb/lapb_in.c
new file mode 100644
index 0000000..b0f8713
--- /dev/null
+++ b/net/lapb/lapb_in.c
@@ -0,0 +1,724 @@
+/*
+ *	LAPB release 002
+ *
+ *	This code REQUIRES 2.1.15 or higher/ NET3.038
+ *
+ *	This module:
+ *		This module 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.
+ *
+ *	History
+ *	LAPB 001	Jonathan Naulor	Started Coding
+ *	LAPB 002	Jonathan Naylor	New timer architecture.
+ *	2000-10-29	Henner Eisen	lapb_data_indication() return status.
+ */
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <net/lapb.h>
+
+/*
+ *	State machine for state 0, Disconnected State.
+ *	The handling of the timer(s) is in file lapb_timer.c.
+ */
+static void lapb_state0_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	switch (frame->type) {
+		case LAPB_SABM:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S0 RX SABM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (lapb->mode & LAPB_EXTENDED) {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S0 TX DM(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_DM, frame->pf,
+						  LAPB_RESPONSE);
+			} else {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n",
+				       lapb->dev);
+#endif
+				lapb_send_control(lapb, LAPB_UA, frame->pf,
+						  LAPB_RESPONSE);
+				lapb_stop_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->state     = LAPB_STATE_3;
+				lapb->condition = 0x00;
+				lapb->n2count   = 0;
+				lapb->vs        = 0;
+				lapb->vr        = 0;
+				lapb->va        = 0;
+				lapb_connect_indication(lapb, LAPB_OK);
+			}
+			break;
+
+		case LAPB_SABME:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S0 RX SABME(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (lapb->mode & LAPB_EXTENDED) {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n",
+				       lapb->dev);
+#endif
+				lapb_send_control(lapb, LAPB_UA, frame->pf,
+						  LAPB_RESPONSE);
+				lapb_stop_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->state     = LAPB_STATE_3;
+				lapb->condition = 0x00;
+				lapb->n2count   = 0;
+				lapb->vs        = 0;
+				lapb->vr        = 0;
+				lapb->va        = 0;
+				lapb_connect_indication(lapb, LAPB_OK);
+			} else {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S0 TX DM(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_DM, frame->pf,
+						  LAPB_RESPONSE);
+			}
+			break;
+
+		case LAPB_DISC:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S0 RX DISC(%d)\n",
+			       lapb->dev, frame->pf);
+			printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+			break;
+
+		default:
+			break;
+	}
+
+	kfree_skb(skb);
+}
+
+/*
+ *	State machine for state 1, Awaiting Connection State.
+ *	The handling of the timer(s) is in file lapb_timer.c.
+ */
+static void lapb_state1_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	switch (frame->type) {
+		case LAPB_SABM:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S1 RX SABM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (lapb->mode & LAPB_EXTENDED) {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_DM, frame->pf,
+						  LAPB_RESPONSE);
+			} else {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S1 TX UA(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_UA, frame->pf,
+						  LAPB_RESPONSE);
+			}
+			break;
+
+		case LAPB_SABME:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S1 RX SABME(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (lapb->mode & LAPB_EXTENDED) {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S1 TX UA(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_UA, frame->pf,
+						  LAPB_RESPONSE);
+			} else {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_DM, frame->pf,
+						  LAPB_RESPONSE);
+			}
+			break;
+
+		case LAPB_DISC:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S1 RX DISC(%d)\n",
+			       lapb->dev, frame->pf);
+			printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+			break;
+
+		case LAPB_UA:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S1 RX UA(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (frame->pf) {
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S1 -> S3\n",
+				       lapb->dev);
+#endif
+				lapb_stop_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->state     = LAPB_STATE_3;
+				lapb->condition = 0x00;
+				lapb->n2count   = 0;
+				lapb->vs        = 0;
+				lapb->vr        = 0;
+				lapb->va        = 0;
+				lapb_connect_confirmation(lapb, LAPB_OK);
+			}
+			break;
+
+		case LAPB_DM:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S1 RX DM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (frame->pf) {
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n",
+				       lapb->dev);
+#endif
+				lapb_clear_queues(lapb);
+				lapb->state = LAPB_STATE_0;
+				lapb_start_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb_disconnect_indication(lapb, LAPB_REFUSED);
+			}
+			break;
+	}
+
+	kfree_skb(skb);
+}
+
+/*
+ *	State machine for state 2, Awaiting Release State.
+ *	The handling of the timer(s) is in file lapb_timer.c
+ */
+static void lapb_state2_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	switch (frame->type) {
+		case LAPB_SABM:
+		case LAPB_SABME:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S2 RX {SABM,SABME}(%d)\n",
+			       lapb->dev, frame->pf);
+			printk(KERN_DEBUG "lapb: (%p) S2 TX DM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			lapb_send_control(lapb, LAPB_DM, frame->pf,
+					  LAPB_RESPONSE);
+			break;
+
+		case LAPB_DISC:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S2 RX DISC(%d)\n",
+			       lapb->dev, frame->pf);
+			printk(KERN_DEBUG "lapb: (%p) S2 TX UA(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+			break;
+
+		case LAPB_UA:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S2 RX UA(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (frame->pf) {
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n",
+				       lapb->dev);
+#endif
+				lapb->state = LAPB_STATE_0;
+				lapb_start_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb_disconnect_confirmation(lapb, LAPB_OK);
+			}
+			break;
+
+		case LAPB_DM:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S2 RX DM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (frame->pf) {
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n",
+				       lapb->dev);
+#endif
+				lapb->state = LAPB_STATE_0;
+				lapb_start_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb_disconnect_confirmation(lapb,
+							     LAPB_NOTCONNECTED);
+			}
+			break;
+
+		case LAPB_I:
+		case LAPB_REJ:
+		case LAPB_RNR:
+		case LAPB_RR:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S2 RX {I,REJ,RNR,RR}"
+			       "(%d)\n", lapb->dev, frame->pf);
+			printk(KERN_DEBUG "lapb: (%p) S2 RX DM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (frame->pf)
+				lapb_send_control(lapb, LAPB_DM, frame->pf,
+						  LAPB_RESPONSE);
+			break;
+	}
+
+	kfree_skb(skb);
+}
+
+/*
+ *	State machine for state 3, Connected State.
+ *	The handling of the timer(s) is in file lapb_timer.c
+ */
+static void lapb_state3_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	int queued = 0;
+	int modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS :
+						     LAPB_SMODULUS;
+
+	switch (frame->type) {
+		case LAPB_SABM:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX SABM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (lapb->mode & LAPB_EXTENDED) {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S3 TX DM(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_DM, frame->pf,
+						  LAPB_RESPONSE);
+			} else {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S3 TX UA(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_UA, frame->pf,
+						  LAPB_RESPONSE);
+				lapb_stop_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->condition = 0x00;
+				lapb->n2count   = 0;
+				lapb->vs        = 0;
+				lapb->vr        = 0;
+				lapb->va        = 0;
+				lapb_requeue_frames(lapb);
+			}
+			break;
+
+		case LAPB_SABME:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX SABME(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (lapb->mode & LAPB_EXTENDED) {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S3 TX UA(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_UA, frame->pf,
+						  LAPB_RESPONSE);
+				lapb_stop_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->condition = 0x00;
+				lapb->n2count   = 0;
+				lapb->vs        = 0;
+				lapb->vr        = 0;
+				lapb->va        = 0;
+				lapb_requeue_frames(lapb);
+			} else {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S3 TX DM(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_DM, frame->pf,
+						  LAPB_RESPONSE);
+			}
+			break;
+
+		case LAPB_DISC:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX DISC(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+#if LAPB_DEBUG > 0
+			printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n",
+			       lapb->dev);
+#endif
+			lapb_clear_queues(lapb);
+			lapb_send_control(lapb, LAPB_UA, frame->pf,
+					  LAPB_RESPONSE);
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state = LAPB_STATE_0;
+			lapb_disconnect_indication(lapb, LAPB_OK);
+			break;
+
+		case LAPB_DM:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX DM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+#if LAPB_DEBUG > 0
+			printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n",
+			       lapb->dev);
+#endif
+			lapb_clear_queues(lapb);
+			lapb->state = LAPB_STATE_0;
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb_disconnect_indication(lapb, LAPB_NOTCONNECTED);
+			break;
+
+		case LAPB_RNR:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX RNR(%d) R%d\n",
+			       lapb->dev, frame->pf, frame->nr);
+#endif
+			lapb->condition |= LAPB_PEER_RX_BUSY_CONDITION;
+			lapb_check_need_response(lapb, frame->cr, frame->pf);
+			if (lapb_validate_nr(lapb, frame->nr)) {
+				lapb_check_iframes_acked(lapb, frame->nr);
+			} else {
+				lapb->frmr_data = *frame;
+				lapb->frmr_type = LAPB_FRMR_Z;
+				lapb_transmit_frmr(lapb);
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n",
+				       lapb->dev);
+#endif
+				lapb_start_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->state   = LAPB_STATE_4;
+				lapb->n2count = 0;
+			}
+			break;
+
+		case LAPB_RR:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX RR(%d) R%d\n",
+			       lapb->dev, frame->pf, frame->nr);
+#endif
+			lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
+			lapb_check_need_response(lapb, frame->cr, frame->pf);
+			if (lapb_validate_nr(lapb, frame->nr)) {
+				lapb_check_iframes_acked(lapb, frame->nr);
+			} else {
+				lapb->frmr_data = *frame;
+				lapb->frmr_type = LAPB_FRMR_Z;
+				lapb_transmit_frmr(lapb);
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n",
+				       lapb->dev);
+#endif
+				lapb_start_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->state   = LAPB_STATE_4;
+				lapb->n2count = 0;
+			}
+			break;
+
+		case LAPB_REJ:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX REJ(%d) R%d\n",
+			       lapb->dev, frame->pf, frame->nr);
+#endif
+			lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
+			lapb_check_need_response(lapb, frame->cr, frame->pf);
+			if (lapb_validate_nr(lapb, frame->nr)) {
+				lapb_frames_acked(lapb, frame->nr);
+				lapb_stop_t1timer(lapb);
+				lapb->n2count = 0;
+				lapb_requeue_frames(lapb);
+			} else {
+				lapb->frmr_data = *frame;
+				lapb->frmr_type = LAPB_FRMR_Z;
+				lapb_transmit_frmr(lapb);
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n",
+				       lapb->dev);
+#endif
+				lapb_start_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->state   = LAPB_STATE_4;
+				lapb->n2count = 0;
+			}
+			break;
+
+		case LAPB_I:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX I(%d) S%d R%d\n",
+			       lapb->dev, frame->pf, frame->ns, frame->nr);
+#endif
+			if (!lapb_validate_nr(lapb, frame->nr)) {
+				lapb->frmr_data = *frame;
+				lapb->frmr_type = LAPB_FRMR_Z;
+				lapb_transmit_frmr(lapb);
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n",
+				       lapb->dev);
+#endif
+				lapb_start_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->state   = LAPB_STATE_4;
+				lapb->n2count = 0;
+				break;
+			}
+			if (lapb->condition & LAPB_PEER_RX_BUSY_CONDITION)
+				lapb_frames_acked(lapb, frame->nr);
+			else
+				lapb_check_iframes_acked(lapb, frame->nr);
+
+			if (frame->ns == lapb->vr) {
+				int cn;
+				cn = lapb_data_indication(lapb, skb);
+				queued = 1;
+				/*
+				 * If upper layer has dropped the frame, we
+				 * basically ignore any further protocol
+				 * processing. This will cause the peer
+				 * to re-transmit the frame later like
+				 * a frame lost on the wire.
+				 */
+				if (cn == NET_RX_DROP) {
+					printk(KERN_DEBUG
+					       "LAPB: rx congestion\n");
+					break;
+				}
+				lapb->vr = (lapb->vr + 1) % modulus;
+				lapb->condition &= ~LAPB_REJECT_CONDITION;
+				if (frame->pf)
+					lapb_enquiry_response(lapb);
+				else {
+					if (!(lapb->condition &
+					      LAPB_ACK_PENDING_CONDITION)) {
+						lapb->condition |= LAPB_ACK_PENDING_CONDITION;
+						lapb_start_t2timer(lapb);
+					}
+				}
+			} else {
+				if (lapb->condition & LAPB_REJECT_CONDITION) {
+					if (frame->pf)
+						lapb_enquiry_response(lapb);
+				} else {
+#if LAPB_DEBUG > 1
+					printk(KERN_DEBUG
+					       "lapb: (%p) S3 TX REJ(%d) R%d\n",
+					       lapb->dev, frame->pf, lapb->vr);
+#endif
+					lapb->condition |= LAPB_REJECT_CONDITION;
+					lapb_send_control(lapb, LAPB_REJ,
+							  frame->pf,
+							  LAPB_RESPONSE);
+					lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
+				}
+			}
+			break;
+
+		case LAPB_FRMR:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX FRMR(%d) %02X "
+			       "%02X %02X %02X %02X\n", lapb->dev, frame->pf,
+			       skb->data[0], skb->data[1], skb->data[2],
+			       skb->data[3], skb->data[4]);
+#endif
+			lapb_establish_data_link(lapb);
+#if LAPB_DEBUG > 0
+			printk(KERN_DEBUG "lapb: (%p) S3 -> S1\n",
+			       lapb->dev);
+#endif
+			lapb_requeue_frames(lapb);
+			lapb->state = LAPB_STATE_1;
+			break;
+
+		case LAPB_ILLEGAL:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S3 RX ILLEGAL(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			lapb->frmr_data = *frame;
+			lapb->frmr_type = LAPB_FRMR_W;
+			lapb_transmit_frmr(lapb);
+#if LAPB_DEBUG > 0
+			printk(KERN_DEBUG "lapb: (%p) S3 -> S4\n", lapb->dev);
+#endif
+			lapb_start_t1timer(lapb);
+			lapb_stop_t2timer(lapb);
+			lapb->state   = LAPB_STATE_4;
+			lapb->n2count = 0;
+			break;
+	}
+
+	if (!queued)
+		kfree_skb(skb);
+}
+
+/*
+ *	State machine for state 4, Frame Reject State.
+ *	The handling of the timer(s) is in file lapb_timer.c.
+ */
+static void lapb_state4_machine(struct lapb_cb *lapb, struct sk_buff *skb,
+				struct lapb_frame *frame)
+{
+	switch (frame->type) {
+		case LAPB_SABM:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S4 RX SABM(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (lapb->mode & LAPB_EXTENDED) {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S4 TX DM(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_DM, frame->pf,
+						  LAPB_RESPONSE);
+			} else {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S4 TX UA(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S4 -> S3\n",
+				       lapb->dev);
+#endif
+				lapb_send_control(lapb, LAPB_UA, frame->pf,
+						  LAPB_RESPONSE);
+				lapb_stop_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->state     = LAPB_STATE_3;
+				lapb->condition = 0x00;
+				lapb->n2count   = 0;
+				lapb->vs        = 0;
+				lapb->vr        = 0;
+				lapb->va        = 0;
+				lapb_connect_indication(lapb, LAPB_OK);
+			}
+			break;
+
+		case LAPB_SABME:
+#if LAPB_DEBUG > 1
+			printk(KERN_DEBUG "lapb: (%p) S4 RX SABME(%d)\n",
+			       lapb->dev, frame->pf);
+#endif
+			if (lapb->mode & LAPB_EXTENDED) {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S4 TX UA(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+#if LAPB_DEBUG > 0
+				printk(KERN_DEBUG "lapb: (%p) S4 -> S3\n",
+				       lapb->dev);
+#endif
+				lapb_send_control(lapb, LAPB_UA, frame->pf,
+						  LAPB_RESPONSE);
+				lapb_stop_t1timer(lapb);
+				lapb_stop_t2timer(lapb);
+				lapb->state     = LAPB_STATE_3;
+				lapb->condition = 0x00;
+				lapb->n2count   = 0;
+				lapb->vs        = 0;
+				lapb->vr        = 0;
+				lapb->va        = 0;
+				lapb_connect_indication(lapb, LAPB_OK);
+			} else {
+#if LAPB_DEBUG > 1
+				printk(KERN_DEBUG "lapb: (%p) S4 TX DM(%d)\n",
+				       lapb->dev, frame->pf);
+#endif
+				lapb_send_control(lapb, LAPB_DM, frame->pf,
+						  LAPB_RESPONSE);
+			}
+			break;
+	}
+
+	kfree_skb(skb);
+}
+
+/*
+ *	Process an incoming LAPB frame
+ */
+void lapb_data_input(struct lapb_cb *lapb, struct sk_buff *skb)
+{
+	struct lapb_frame frame;
+
+	if (lapb_decode(lapb, skb, &frame) < 0) {
+		kfree_skb(skb);
+		return;
+	}
+
+	switch (lapb->state) {
+	case LAPB_STATE_0:
+		lapb_state0_machine(lapb, skb, &frame); break;
+	case LAPB_STATE_1:
+		lapb_state1_machine(lapb, skb, &frame); break;
+	case LAPB_STATE_2:
+		lapb_state2_machine(lapb, skb, &frame); break;
+	case LAPB_STATE_3:
+		lapb_state3_machine(lapb, skb, &frame); break;
+	case LAPB_STATE_4:
+		lapb_state4_machine(lapb, skb, &frame); break;
+	}
+
+	lapb_kick(lapb);
+}