[linux-2.6-block.git] / net / lapb / lapb_in.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *	LAPB release 002
 *
 *	This code REQUIRES 2.1.15 or higher/ NET3.038
 *
 *	History
 *	LAPB 001	Jonathan Naulor	Started Coding
 *	LAPB 002	Jonathan Naylor	New timer architecture.
 *	2000-10-29	Henner Eisen	lapb_data_indication() return status.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.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 <linux/slab.h>
#include <net/sock.h>
#include <linux/uaccess.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:
		lapb_dbg(1, "(%p) S0 RX SABM(%d)\n", lapb->dev, frame->pf);
		if (lapb->mode & LAPB_EXTENDED) {
			lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
				 lapb->dev, frame->pf);
			lapb_send_control(lapb, LAPB_DM, frame->pf,
					  LAPB_RESPONSE);
		} else {
			lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
				 lapb->dev, frame->pf);
			lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
			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:
		lapb_dbg(1, "(%p) S0 RX SABME(%d)\n", lapb->dev, frame->pf);
		if (lapb->mode & LAPB_EXTENDED) {
			lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
				 lapb->dev, frame->pf);
			lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
			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 {
			lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
				 lapb->dev, frame->pf);
			lapb_send_control(lapb, LAPB_DM, frame->pf,
					  LAPB_RESPONSE);
		}
		break;

	case LAPB_DISC:
		lapb_dbg(1, "(%p) S0 RX DISC(%d)\n", lapb->dev, frame->pf);
		lapb_dbg(1, "(%p) S0 TX UA(%d)\n", lapb->dev, frame->pf);
		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:
		lapb_dbg(1, "(%p) S1 RX SABM(%d)\n", lapb->dev, frame->pf);
		if (lapb->mode & LAPB_EXTENDED) {
			lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
				 lapb->dev, frame->pf);
			lapb_send_control(lapb, LAPB_DM, frame->pf,
					  LAPB_RESPONSE);
		} else {
			lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
				 lapb->dev, frame->pf);
			lapb_send_control(lapb, LAPB_UA, frame->pf,
					  LAPB_RESPONSE);
		}
		break;

	case LAPB_SABME:
		lapb_dbg(1, "(%p) S1 RX SABME(%d)\n", lapb->dev, frame->pf);
		if (lapb->mode & LAPB_EXTENDED) {
			lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
				 lapb->dev, frame->pf);
			lapb_send_control(lapb, LAPB_UA, frame->pf,
					  LAPB_RESPONSE);
		} else {
			lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
				 lapb->dev, frame->pf);
			lapb_send_control(lapb, LAPB_DM, frame->pf,
					  LAPB_RESPONSE);
		}
		break;

	case LAPB_DISC:
		lapb_dbg(1, "(%p) S1 RX DISC(%d)\n", lapb->dev, frame->pf);
		lapb_dbg(1, "(%p) S1 TX DM(%d)\n", lapb->dev, frame->pf);
		lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
		break;

	case LAPB_UA:
		lapb_dbg(1, "(%p) S1 RX UA(%d)\n", lapb->dev, frame->pf);
		if (frame->pf) {
			lapb_dbg(0, "(%p) S1 -> S3\n", lapb->dev);
			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:
		lapb_dbg(1, "(%p) S1 RX DM(%d)\n", lapb->dev, frame->pf);
		if (frame->pf) {
			lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
			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:
		lapb_dbg(1, "(%p) S2 RX {SABM,SABME}(%d)\n",
			 lapb->dev, frame->pf);
		lapb_dbg(1, "(%p) S2 TX DM(%d)\n", lapb->dev, frame->pf);
		lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
		break;

	case LAPB_DISC:
		lapb_dbg(1, "(%p) S2 RX DISC(%d)\n", lapb->dev, frame->pf);
		lapb_dbg(1, "(%p) S2 TX UA(%d)\n", lapb->dev, frame->pf);
		lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
		break;

	case LAPB_UA:
		lapb_dbg(1, "(%p) S2 RX UA(%d)\n", lapb->dev, frame->pf);
		if (frame->pf) {
			lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
			lapb->state = LAPB_STATE_0;
			lapb_start_t1timer(lapb);
			lapb_stop_t2timer(lapb);
			lapb_disconnect_confirmation(lapb, LAPB_OK);
		}
		break;

	case LAPB_DM:
		lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
		if (frame->pf) {
			lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
			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:
		lapb_dbg(1, "(%p) S2 RX {I,REJ,RNR,RR}(%d)\n",
		       lapb->dev, frame->pf);
		lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
		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:
		lapb_dbg(1, "(%p) S3 RX SABM(%d)\n", lapb->dev, frame->pf);
		if (lapb->mode & LAPB_EXTENDED) {
			lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
				 lapb->dev, frame->pf);
			lapb_send_control(lapb, LAPB_DM, frame->pf,
					  LAPB_RESPONSE);
		} else {
			lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
				 lapb->dev, frame->pf);
			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:
		lapb_dbg(1, "(%p) S3 RX SABME(%d)\n", lapb->dev, frame->pf);
		if (lapb->mode & LAPB_EXTENDED) {
			lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
				 lapb->dev, frame->pf);
			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 {
			lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
				 lapb->dev, frame->pf);
			lapb_send_control(lapb, LAPB_DM, frame->pf,
					  LAPB_RESPONSE);
		}
		break;

	case LAPB_DISC:
		lapb_dbg(1, "(%p) S3 RX DISC(%d)\n", lapb->dev, frame->pf);
		lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
		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:
		lapb_dbg(1, "(%p) S3 RX DM(%d)\n", lapb->dev, frame->pf);
		lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
		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:
		lapb_dbg(1, "(%p) S3 RX RNR(%d) R%d\n",
			 lapb->dev, frame->pf, frame->nr);
		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);
			lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
			lapb_start_t1timer(lapb);
			lapb_stop_t2timer(lapb);
			lapb->state   = LAPB_STATE_4;
			lapb->n2count = 0;
		}
		break;

	case LAPB_RR:
		lapb_dbg(1, "(%p) S3 RX RR(%d) R%d\n",
			 lapb->dev, frame->pf, frame->nr);
		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);
			lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
			lapb_start_t1timer(lapb);
			lapb_stop_t2timer(lapb);
			lapb->state   = LAPB_STATE_4;
			lapb->n2count = 0;
		}
		break;

	case LAPB_REJ:
		lapb_dbg(1, "(%p) S3 RX REJ(%d) R%d\n",
			 lapb->dev, frame->pf, frame->nr);
		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);
			lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
			lapb_start_t1timer(lapb);
			lapb_stop_t2timer(lapb);
			lapb->state   = LAPB_STATE_4;
			lapb->n2count = 0;
		}
		break;

	case LAPB_I:
		lapb_dbg(1, "(%p) S3 RX I(%d) S%d R%d\n",
			 lapb->dev, frame->pf, frame->ns, frame->nr);
		if (!lapb_validate_nr(lapb, frame->nr)) {
			lapb->frmr_data = *frame;
			lapb->frmr_type = LAPB_FRMR_Z;
			lapb_transmit_frmr(lapb);
			lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
			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) {
				pr_debug("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 {
				lapb_dbg(1, "(%p) S3 TX REJ(%d) R%d\n",
					 lapb->dev, frame->pf, lapb->vr);
				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:
		lapb_dbg(1, "(%p) S3 RX FRMR(%d) %5ph\n",
			 lapb->dev, frame->pf,
			 skb->data);
		lapb_establish_data_link(lapb);
		lapb_dbg(0, "(%p) S3 -> S1\n", lapb->dev);
		lapb_requeue_frames(lapb);
		lapb->state = LAPB_STATE_1;
		break;

	case LAPB_ILLEGAL:
		lapb_dbg(1, "(%p) S3 RX ILLEGAL(%d)\n", lapb->dev, frame->pf);
		lapb->frmr_data = *frame;
		lapb->frmr_type = LAPB_FRMR_W;
		lapb_transmit_frmr(lapb);
		lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
		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:
		lapb_dbg(1, "(%p) S4 RX SABM(%d)\n", lapb->dev, frame->pf);
		if (lapb->mode & LAPB_EXTENDED) {
			lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
				 lapb->dev, frame->pf);
			lapb_send_control(lapb, LAPB_DM, frame->pf,
					  LAPB_RESPONSE);
		} else {
			lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
				 lapb->dev, frame->pf);
			lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
			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:
		lapb_dbg(1, "(%p) S4 RX SABME(%d)\n", lapb->dev, frame->pf);
		if (lapb->mode & LAPB_EXTENDED) {
			lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
				 lapb->dev, frame->pf);
			lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
			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 {
			lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
				 lapb->dev, frame->pf);
			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);
}
Commit	Line	Data
ee5d8f4d	1	// SPDX-License-Identifier: GPL-2.0-or-later
1da177e4 LT	2	/*
	3	* LAPB release 002
	4	*
	5	* This code REQUIRES 2.1.15 or higher/ NET3.038
	6	*
1da177e4 LT	7	* History
	8	* LAPB 001 Jonathan Naulor Started Coding
	9	* LAPB 002 Jonathan Naylor New timer architecture.
	10	* 2000-10-29 Henner Eisen lapb_data_indication() return status.
	11	*/
	12
a508da6c JP	13	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
a508da6c JP	14
1da177e4 LT	15	#include <linux/errno.h>
	16	#include <linux/types.h>
	17	#include <linux/socket.h>
	18	#include <linux/in.h>
	19	#include <linux/kernel.h>
1da177e4 LT	20	#include <linux/timer.h>
	21	#include <linux/string.h>
	22	#include <linux/sockios.h>
	23	#include <linux/net.h>
	24	#include <linux/inet.h>
	25	#include <linux/netdevice.h>
	26	#include <linux/skbuff.h>
5a0e3ad6	27	#include <linux/slab.h>
1da177e4	28	#include <net/sock.h>
7c0f6ba6	29	#include <linux/uaccess.h>
1da177e4 LT	30	#include <linux/fcntl.h>
	31	#include <linux/mm.h>
	32	#include <linux/interrupt.h>
	33	#include <net/lapb.h>
	34
	35	/*
	36	* State machine for state 0, Disconnected State.
	37	* The handling of the timer(s) is in file lapb_timer.c.
	38	*/
	39	static void lapb_state0_machine(struct lapb_cb lapb, struct sk_buff skb,
	40	struct lapb_frame *frame)
	41	{
	42	switch (frame->type) {
fcb261f3	43	case LAPB_SABM:
a508da6c	44	lapb_dbg(1, "(%p) S0 RX SABM(%d)\n", lapb->dev, frame->pf);
fcb261f3	45	if (lapb->mode & LAPB_EXTENDED) {
a508da6c JP	46	lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
a508da6c JP	47	lapb->dev, frame->pf);
fcb261f3 JP	48	lapb_send_control(lapb, LAPB_DM, frame->pf,
	49	LAPB_RESPONSE);
	50	} else {
a508da6c JP	51	lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
	52	lapb->dev, frame->pf);
	53	lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
fcb261f3 JP	54	lapb_send_control(lapb, LAPB_UA, frame->pf,
	55	LAPB_RESPONSE);
	56	lapb_stop_t1timer(lapb);
	57	lapb_stop_t2timer(lapb);
	58	lapb->state = LAPB_STATE_3;
	59	lapb->condition = 0x00;
	60	lapb->n2count = 0;
	61	lapb->vs = 0;
	62	lapb->vr = 0;
	63	lapb->va = 0;
	64	lapb_connect_indication(lapb, LAPB_OK);
	65	}
	66	break;
1da177e4	67
fcb261f3	68	case LAPB_SABME:
a508da6c	69	lapb_dbg(1, "(%p) S0 RX SABME(%d)\n", lapb->dev, frame->pf);
fcb261f3	70	if (lapb->mode & LAPB_EXTENDED) {
a508da6c JP	71	lapb_dbg(1, "(%p) S0 TX UA(%d)\n",
	72	lapb->dev, frame->pf);
	73	lapb_dbg(0, "(%p) S0 -> S3\n", lapb->dev);
fcb261f3 JP	74	lapb_send_control(lapb, LAPB_UA, frame->pf,
	75	LAPB_RESPONSE);
	76	lapb_stop_t1timer(lapb);
	77	lapb_stop_t2timer(lapb);
	78	lapb->state = LAPB_STATE_3;
	79	lapb->condition = 0x00;
	80	lapb->n2count = 0;
	81	lapb->vs = 0;
	82	lapb->vr = 0;
	83	lapb->va = 0;
	84	lapb_connect_indication(lapb, LAPB_OK);
	85	} else {
a508da6c JP	86	lapb_dbg(1, "(%p) S0 TX DM(%d)\n",
a508da6c JP	87	lapb->dev, frame->pf);
fcb261f3 JP	88	lapb_send_control(lapb, LAPB_DM, frame->pf,
	89	LAPB_RESPONSE);
	90	}
	91	break;
1da177e4	92
fcb261f3	93	case LAPB_DISC:
a508da6c JP	94	lapb_dbg(1, "(%p) S0 RX DISC(%d)\n", lapb->dev, frame->pf);
a508da6c JP	95	lapb_dbg(1, "(%p) S0 TX UA(%d)\n", lapb->dev, frame->pf);
fcb261f3 JP	96	lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
fcb261f3 JP	97	break;
1da177e4	98
fcb261f3 JP	99	default:
fcb261f3 JP	100	break;
1da177e4 LT	101	}
	102
	103	kfree_skb(skb);
	104	}
	105
	106	/*
	107	* State machine for state 1, Awaiting Connection State.
	108	* The handling of the timer(s) is in file lapb_timer.c.
	109	*/
	110	static void lapb_state1_machine(struct lapb_cb lapb, struct sk_buff skb,
	111	struct lapb_frame *frame)
	112	{
	113	switch (frame->type) {
fcb261f3	114	case LAPB_SABM:
a508da6c	115	lapb_dbg(1, "(%p) S1 RX SABM(%d)\n", lapb->dev, frame->pf);
fcb261f3	116	if (lapb->mode & LAPB_EXTENDED) {
a508da6c JP	117	lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
a508da6c JP	118	lapb->dev, frame->pf);
fcb261f3 JP	119	lapb_send_control(lapb, LAPB_DM, frame->pf,
	120	LAPB_RESPONSE);
	121	} else {
a508da6c JP	122	lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
a508da6c JP	123	lapb->dev, frame->pf);
fcb261f3 JP	124	lapb_send_control(lapb, LAPB_UA, frame->pf,
	125	LAPB_RESPONSE);
	126	}
	127	break;
	128
	129	case LAPB_SABME:
a508da6c	130	lapb_dbg(1, "(%p) S1 RX SABME(%d)\n", lapb->dev, frame->pf);
fcb261f3	131	if (lapb->mode & LAPB_EXTENDED) {
a508da6c JP	132	lapb_dbg(1, "(%p) S1 TX UA(%d)\n",
a508da6c JP	133	lapb->dev, frame->pf);
fcb261f3 JP	134	lapb_send_control(lapb, LAPB_UA, frame->pf,
	135	LAPB_RESPONSE);
	136	} else {
a508da6c JP	137	lapb_dbg(1, "(%p) S1 TX DM(%d)\n",
a508da6c JP	138	lapb->dev, frame->pf);
1da177e4 LT	139	lapb_send_control(lapb, LAPB_DM, frame->pf,
1da177e4 LT	140	LAPB_RESPONSE);
fcb261f3 JP	141	}
fcb261f3 JP	142	break;
1da177e4	143
fcb261f3	144	case LAPB_DISC:
a508da6c JP	145	lapb_dbg(1, "(%p) S1 RX DISC(%d)\n", lapb->dev, frame->pf);
a508da6c JP	146	lapb_dbg(1, "(%p) S1 TX DM(%d)\n", lapb->dev, frame->pf);
fcb261f3 JP	147	lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
fcb261f3 JP	148	break;
1da177e4	149
fcb261f3	150	case LAPB_UA:
a508da6c	151	lapb_dbg(1, "(%p) S1 RX UA(%d)\n", lapb->dev, frame->pf);
fcb261f3	152	if (frame->pf) {
a508da6c	153	lapb_dbg(0, "(%p) S1 -> S3\n", lapb->dev);
fcb261f3 JP	154	lapb_stop_t1timer(lapb);
	155	lapb_stop_t2timer(lapb);
	156	lapb->state = LAPB_STATE_3;
	157	lapb->condition = 0x00;
	158	lapb->n2count = 0;
	159	lapb->vs = 0;
	160	lapb->vr = 0;
	161	lapb->va = 0;
	162	lapb_connect_confirmation(lapb, LAPB_OK);
	163	}
	164	break;
	165
	166	case LAPB_DM:
a508da6c	167	lapb_dbg(1, "(%p) S1 RX DM(%d)\n", lapb->dev, frame->pf);
fcb261f3	168	if (frame->pf) {
a508da6c	169	lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
fcb261f3 JP	170	lapb_clear_queues(lapb);
	171	lapb->state = LAPB_STATE_0;
	172	lapb_start_t1timer(lapb);
	173	lapb_stop_t2timer(lapb);
	174	lapb_disconnect_indication(lapb, LAPB_REFUSED);
	175	}
	176	break;
1da177e4 LT	177	}
	178
	179	kfree_skb(skb);
	180	}
	181
	182	/*
	183	* State machine for state 2, Awaiting Release State.
	184	* The handling of the timer(s) is in file lapb_timer.c
	185	*/
	186	static void lapb_state2_machine(struct lapb_cb lapb, struct sk_buff skb,
	187	struct lapb_frame *frame)
	188	{
	189	switch (frame->type) {
fcb261f3 JP	190	case LAPB_SABM:
fcb261f3 JP	191	case LAPB_SABME:
a508da6c JP	192	lapb_dbg(1, "(%p) S2 RX {SABM,SABME}(%d)\n",
	193	lapb->dev, frame->pf);
	194	lapb_dbg(1, "(%p) S2 TX DM(%d)\n", lapb->dev, frame->pf);
fcb261f3 JP	195	lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
fcb261f3 JP	196	break;
1da177e4	197
fcb261f3	198	case LAPB_DISC:
a508da6c JP	199	lapb_dbg(1, "(%p) S2 RX DISC(%d)\n", lapb->dev, frame->pf);
a508da6c JP	200	lapb_dbg(1, "(%p) S2 TX UA(%d)\n", lapb->dev, frame->pf);
fcb261f3 JP	201	lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
fcb261f3 JP	202	break;
1da177e4	203
fcb261f3	204	case LAPB_UA:
a508da6c	205	lapb_dbg(1, "(%p) S2 RX UA(%d)\n", lapb->dev, frame->pf);
fcb261f3	206	if (frame->pf) {
a508da6c	207	lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
fcb261f3 JP	208	lapb->state = LAPB_STATE_0;
	209	lapb_start_t1timer(lapb);
	210	lapb_stop_t2timer(lapb);
	211	lapb_disconnect_confirmation(lapb, LAPB_OK);
	212	}
	213	break;
1da177e4	214
fcb261f3	215	case LAPB_DM:
a508da6c	216	lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
fcb261f3	217	if (frame->pf) {
a508da6c	218	lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
fcb261f3 JP	219	lapb->state = LAPB_STATE_0;
	220	lapb_start_t1timer(lapb);
	221	lapb_stop_t2timer(lapb);
	222	lapb_disconnect_confirmation(lapb, LAPB_NOTCONNECTED);
	223	}
	224	break;
1da177e4	225
fcb261f3 JP	226	case LAPB_I:
	227	case LAPB_REJ:
	228	case LAPB_RNR:
	229	case LAPB_RR:
a508da6c	230	lapb_dbg(1, "(%p) S2 RX {I,REJ,RNR,RR}(%d)\n",
fcb261f3	231	lapb->dev, frame->pf);
a508da6c	232	lapb_dbg(1, "(%p) S2 RX DM(%d)\n", lapb->dev, frame->pf);
fcb261f3 JP	233	if (frame->pf)
	234	lapb_send_control(lapb, LAPB_DM, frame->pf,
	235	LAPB_RESPONSE);
	236	break;
1da177e4 LT	237	}
	238
	239	kfree_skb(skb);
	240	}
	241
	242	/*
	243	* State machine for state 3, Connected State.
	244	* The handling of the timer(s) is in file lapb_timer.c
	245	*/
	246	static void lapb_state3_machine(struct lapb_cb lapb, struct sk_buff skb,
	247	struct lapb_frame *frame)
	248	{
	249	int queued = 0;
	250	int modulus = (lapb->mode & LAPB_EXTENDED) ? LAPB_EMODULUS :
	251	LAPB_SMODULUS;
	252
	253	switch (frame->type) {
fcb261f3	254	case LAPB_SABM:
a508da6c	255	lapb_dbg(1, "(%p) S3 RX SABM(%d)\n", lapb->dev, frame->pf);
fcb261f3	256	if (lapb->mode & LAPB_EXTENDED) {
a508da6c JP	257	lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
a508da6c JP	258	lapb->dev, frame->pf);
fcb261f3 JP	259	lapb_send_control(lapb, LAPB_DM, frame->pf,
	260	LAPB_RESPONSE);
	261	} else {
a508da6c JP	262	lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
a508da6c JP	263	lapb->dev, frame->pf);
fcb261f3 JP	264	lapb_send_control(lapb, LAPB_UA, frame->pf,
	265	LAPB_RESPONSE);
	266	lapb_stop_t1timer(lapb);
	267	lapb_stop_t2timer(lapb);
	268	lapb->condition = 0x00;
	269	lapb->n2count = 0;
	270	lapb->vs = 0;
	271	lapb->vr = 0;
	272	lapb->va = 0;
	273	lapb_requeue_frames(lapb);
	274	}
	275	break;
1da177e4	276
fcb261f3	277	case LAPB_SABME:
a508da6c	278	lapb_dbg(1, "(%p) S3 RX SABME(%d)\n", lapb->dev, frame->pf);
fcb261f3	279	if (lapb->mode & LAPB_EXTENDED) {
a508da6c JP	280	lapb_dbg(1, "(%p) S3 TX UA(%d)\n",
a508da6c JP	281	lapb->dev, frame->pf);
fcb261f3 JP	282	lapb_send_control(lapb, LAPB_UA, frame->pf,
	283	LAPB_RESPONSE);
	284	lapb_stop_t1timer(lapb);
	285	lapb_stop_t2timer(lapb);
	286	lapb->condition = 0x00;
	287	lapb->n2count = 0;
	288	lapb->vs = 0;
	289	lapb->vr = 0;
	290	lapb->va = 0;
	291	lapb_requeue_frames(lapb);
	292	} else {
a508da6c JP	293	lapb_dbg(1, "(%p) S3 TX DM(%d)\n",
a508da6c JP	294	lapb->dev, frame->pf);
fcb261f3 JP	295	lapb_send_control(lapb, LAPB_DM, frame->pf,
	296	LAPB_RESPONSE);
	297	}
	298	break;
1da177e4	299
fcb261f3	300	case LAPB_DISC:
a508da6c JP	301	lapb_dbg(1, "(%p) S3 RX DISC(%d)\n", lapb->dev, frame->pf);
a508da6c JP	302	lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
fcb261f3 JP	303	lapb_clear_queues(lapb);
	304	lapb_send_control(lapb, LAPB_UA, frame->pf, LAPB_RESPONSE);
	305	lapb_start_t1timer(lapb);
	306	lapb_stop_t2timer(lapb);
	307	lapb->state = LAPB_STATE_0;
	308	lapb_disconnect_indication(lapb, LAPB_OK);
	309	break;
1da177e4	310
fcb261f3	311	case LAPB_DM:
a508da6c JP	312	lapb_dbg(1, "(%p) S3 RX DM(%d)\n", lapb->dev, frame->pf);
a508da6c JP	313	lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
fcb261f3 JP	314	lapb_clear_queues(lapb);
	315	lapb->state = LAPB_STATE_0;
	316	lapb_start_t1timer(lapb);
	317	lapb_stop_t2timer(lapb);
	318	lapb_disconnect_indication(lapb, LAPB_NOTCONNECTED);
	319	break;
1da177e4	320
fcb261f3	321	case LAPB_RNR:
a508da6c JP	322	lapb_dbg(1, "(%p) S3 RX RNR(%d) R%d\n",
a508da6c JP	323	lapb->dev, frame->pf, frame->nr);
fcb261f3 JP	324	lapb->condition \|= LAPB_PEER_RX_BUSY_CONDITION;
	325	lapb_check_need_response(lapb, frame->cr, frame->pf);
	326	if (lapb_validate_nr(lapb, frame->nr)) {
	327	lapb_check_iframes_acked(lapb, frame->nr);
	328	} else {
	329	lapb->frmr_data = *frame;
	330	lapb->frmr_type = LAPB_FRMR_Z;
	331	lapb_transmit_frmr(lapb);
a508da6c	332	lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
fcb261f3 JP	333	lapb_start_t1timer(lapb);
	334	lapb_stop_t2timer(lapb);
	335	lapb->state = LAPB_STATE_4;
	336	lapb->n2count = 0;
	337	}
	338	break;
1da177e4	339
fcb261f3	340	case LAPB_RR:
a508da6c JP	341	lapb_dbg(1, "(%p) S3 RX RR(%d) R%d\n",
a508da6c JP	342	lapb->dev, frame->pf, frame->nr);
fcb261f3 JP	343	lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
	344	lapb_check_need_response(lapb, frame->cr, frame->pf);
	345	if (lapb_validate_nr(lapb, frame->nr)) {
	346	lapb_check_iframes_acked(lapb, frame->nr);
	347	} else {
	348	lapb->frmr_data = *frame;
	349	lapb->frmr_type = LAPB_FRMR_Z;
	350	lapb_transmit_frmr(lapb);
a508da6c	351	lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
fcb261f3 JP	352	lapb_start_t1timer(lapb);
	353	lapb_stop_t2timer(lapb);
	354	lapb->state = LAPB_STATE_4;
	355	lapb->n2count = 0;
	356	}
	357	break;
1da177e4	358
fcb261f3	359	case LAPB_REJ:
a508da6c JP	360	lapb_dbg(1, "(%p) S3 RX REJ(%d) R%d\n",
a508da6c JP	361	lapb->dev, frame->pf, frame->nr);
fcb261f3 JP	362	lapb->condition &= ~LAPB_PEER_RX_BUSY_CONDITION;
	363	lapb_check_need_response(lapb, frame->cr, frame->pf);
	364	if (lapb_validate_nr(lapb, frame->nr)) {
	365	lapb_frames_acked(lapb, frame->nr);
	366	lapb_stop_t1timer(lapb);
	367	lapb->n2count = 0;
	368	lapb_requeue_frames(lapb);
	369	} else {
	370	lapb->frmr_data = *frame;
	371	lapb->frmr_type = LAPB_FRMR_Z;
	372	lapb_transmit_frmr(lapb);
a508da6c	373	lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
fcb261f3 JP	374	lapb_start_t1timer(lapb);
	375	lapb_stop_t2timer(lapb);
	376	lapb->state = LAPB_STATE_4;
	377	lapb->n2count = 0;
	378	}
	379	break;
1da177e4	380
fcb261f3	381	case LAPB_I:
a508da6c JP	382	lapb_dbg(1, "(%p) S3 RX I(%d) S%d R%d\n",
a508da6c JP	383	lapb->dev, frame->pf, frame->ns, frame->nr);
fcb261f3 JP	384	if (!lapb_validate_nr(lapb, frame->nr)) {
	385	lapb->frmr_data = *frame;
	386	lapb->frmr_type = LAPB_FRMR_Z;
	387	lapb_transmit_frmr(lapb);
a508da6c	388	lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
fcb261f3 JP	389	lapb_start_t1timer(lapb);
	390	lapb_stop_t2timer(lapb);
	391	lapb->state = LAPB_STATE_4;
	392	lapb->n2count = 0;
	393	break;
	394	}
	395	if (lapb->condition & LAPB_PEER_RX_BUSY_CONDITION)
	396	lapb_frames_acked(lapb, frame->nr);
	397	else
	398	lapb_check_iframes_acked(lapb, frame->nr);
	399
	400	if (frame->ns == lapb->vr) {
	401	int cn;
	402	cn = lapb_data_indication(lapb, skb);
	403	queued = 1;
	404	/*
	405	* If upper layer has dropped the frame, we
	406	* basically ignore any further protocol
	407	* processing. This will cause the peer
	408	* to re-transmit the frame later like
	409	* a frame lost on the wire.
	410	*/
	411	if (cn == NET_RX_DROP) {
a508da6c	412	pr_debug("rx congestion\n");
1da177e4 LT	413	break;
1da177e4 LT	414	}
fcb261f3 JP	415	lapb->vr = (lapb->vr + 1) % modulus;
	416	lapb->condition &= ~LAPB_REJECT_CONDITION;
	417	if (frame->pf)
	418	lapb_enquiry_response(lapb);
	419	else {
	420	if (!(lapb->condition &
	421	LAPB_ACK_PENDING_CONDITION)) {
	422	lapb->condition \|= LAPB_ACK_PENDING_CONDITION;
	423	lapb_start_t2timer(lapb);
1da177e4	424	}
fcb261f3 JP	425	}
	426	} else {
	427	if (lapb->condition & LAPB_REJECT_CONDITION) {
1da177e4 LT	428	if (frame->pf)
1da177e4 LT	429	lapb_enquiry_response(lapb);
1da177e4	430	} else {
a508da6c JP	431	lapb_dbg(1, "(%p) S3 TX REJ(%d) R%d\n",
a508da6c JP	432	lapb->dev, frame->pf, lapb->vr);
fcb261f3 JP	433	lapb->condition \|= LAPB_REJECT_CONDITION;
	434	lapb_send_control(lapb, LAPB_REJ, frame->pf,
	435	LAPB_RESPONSE);
	436	lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
1da177e4	437	}
fcb261f3 JP	438	}
fcb261f3 JP	439	break;
1da177e4	440
fcb261f3	441	case LAPB_FRMR:
0d08df6c	442	lapb_dbg(1, "(%p) S3 RX FRMR(%d) %5ph\n",
a508da6c	443	lapb->dev, frame->pf,
0d08df6c	444	skb->data);
fcb261f3	445	lapb_establish_data_link(lapb);
a508da6c	446	lapb_dbg(0, "(%p) S3 -> S1\n", lapb->dev);
fcb261f3 JP	447	lapb_requeue_frames(lapb);
	448	lapb->state = LAPB_STATE_1;
	449	break;
1da177e4	450
fcb261f3	451	case LAPB_ILLEGAL:
a508da6c	452	lapb_dbg(1, "(%p) S3 RX ILLEGAL(%d)\n", lapb->dev, frame->pf);
fcb261f3 JP	453	lapb->frmr_data = *frame;
	454	lapb->frmr_type = LAPB_FRMR_W;
	455	lapb_transmit_frmr(lapb);
a508da6c	456	lapb_dbg(0, "(%p) S3 -> S4\n", lapb->dev);
fcb261f3 JP	457	lapb_start_t1timer(lapb);
	458	lapb_stop_t2timer(lapb);
	459	lapb->state = LAPB_STATE_4;
	460	lapb->n2count = 0;
	461	break;
1da177e4 LT	462	}
	463
	464	if (!queued)
	465	kfree_skb(skb);
	466	}
	467
	468	/*
	469	* State machine for state 4, Frame Reject State.
	470	* The handling of the timer(s) is in file lapb_timer.c.
	471	*/
	472	static void lapb_state4_machine(struct lapb_cb lapb, struct sk_buff skb,
	473	struct lapb_frame *frame)
	474	{
	475	switch (frame->type) {
fcb261f3	476	case LAPB_SABM:
a508da6c	477	lapb_dbg(1, "(%p) S4 RX SABM(%d)\n", lapb->dev, frame->pf);
fcb261f3	478	if (lapb->mode & LAPB_EXTENDED) {
a508da6c JP	479	lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
a508da6c JP	480	lapb->dev, frame->pf);
fcb261f3 JP	481	lapb_send_control(lapb, LAPB_DM, frame->pf,
	482	LAPB_RESPONSE);
	483	} else {
a508da6c JP	484	lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
	485	lapb->dev, frame->pf);
	486	lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
fcb261f3 JP	487	lapb_send_control(lapb, LAPB_UA, frame->pf,
	488	LAPB_RESPONSE);
	489	lapb_stop_t1timer(lapb);
	490	lapb_stop_t2timer(lapb);
	491	lapb->state = LAPB_STATE_3;
	492	lapb->condition = 0x00;
	493	lapb->n2count = 0;
	494	lapb->vs = 0;
	495	lapb->vr = 0;
	496	lapb->va = 0;
	497	lapb_connect_indication(lapb, LAPB_OK);
	498	}
	499	break;
1da177e4	500
fcb261f3	501	case LAPB_SABME:
a508da6c	502	lapb_dbg(1, "(%p) S4 RX SABME(%d)\n", lapb->dev, frame->pf);
fcb261f3	503	if (lapb->mode & LAPB_EXTENDED) {
a508da6c JP	504	lapb_dbg(1, "(%p) S4 TX UA(%d)\n",
	505	lapb->dev, frame->pf);
	506	lapb_dbg(0, "(%p) S4 -> S3\n", lapb->dev);
fcb261f3 JP	507	lapb_send_control(lapb, LAPB_UA, frame->pf,
	508	LAPB_RESPONSE);
	509	lapb_stop_t1timer(lapb);
	510	lapb_stop_t2timer(lapb);
	511	lapb->state = LAPB_STATE_3;
	512	lapb->condition = 0x00;
	513	lapb->n2count = 0;
	514	lapb->vs = 0;
	515	lapb->vr = 0;
	516	lapb->va = 0;
	517	lapb_connect_indication(lapb, LAPB_OK);
	518	} else {
a508da6c JP	519	lapb_dbg(1, "(%p) S4 TX DM(%d)\n",
a508da6c JP	520	lapb->dev, frame->pf);
fcb261f3 JP	521	lapb_send_control(lapb, LAPB_DM, frame->pf,
	522	LAPB_RESPONSE);
	523	}
	524	break;
1da177e4 LT	525	}
	526
	527	kfree_skb(skb);
	528	}
	529
	530	/*
	531	* Process an incoming LAPB frame
	532	*/
	533	void lapb_data_input(struct lapb_cb lapb, struct sk_buff skb)
	534	{
	535	struct lapb_frame frame;
	536
	537	if (lapb_decode(lapb, skb, &frame) < 0) {
	538	kfree_skb(skb);
	539	return;
	540	}
	541
	542	switch (lapb->state) {
	543	case LAPB_STATE_0:
	544	lapb_state0_machine(lapb, skb, &frame); break;
	545	case LAPB_STATE_1:
	546	lapb_state1_machine(lapb, skb, &frame); break;
	547	case LAPB_STATE_2:
	548	lapb_state2_machine(lapb, skb, &frame); break;
	549	case LAPB_STATE_3:
	550	lapb_state3_machine(lapb, skb, &frame); break;
	551	case LAPB_STATE_4:
	552	lapb_state4_machine(lapb, skb, &frame); break;
	553	}
	554
	555	lapb_kick(lapb);
	556	}