lapb_in.c

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/*
 *	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(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->token, frame->pf);
#endif
			if (lapb->mode & LAPB_EXTENDED) {
#if LAPB_DEBUG > 1
				printk(KERN_DEBUG "lapb: (%p) S0 TX DM(%d)\n", lapb->token, 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->token, frame->pf);
#endif
#if LAPB_DEBUG > 0
				printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n", lapb->token);
#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->token, frame->pf);
#endif
			if (lapb->mode & LAPB_EXTENDED) {
#if LAPB_DEBUG > 1
				printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n", lapb->token, frame->pf);
#endif
#if LAPB_DEBUG > 0
				printk(KERN_DEBUG "lapb: (%p) S0 -> S3\n", lapb->token);
#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->token, 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->token, frame->pf);
			printk(KERN_DEBUG "lapb: (%p) S0 TX UA(%d)\n", lapb->token, 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(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->token, frame->pf);
#endif
			if (lapb->mode & LAPB_EXTENDED) {
#if LAPB_DEBUG > 1
				printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n", lapb->token, 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->token, 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->token, frame->pf);
#endif
			if (lapb->mode & LAPB_EXTENDED) {
#if LAPB_DEBUG > 1
				printk(KERN_DEBUG "lapb: (%p) S1 TX UA(%d)\n", lapb->token, 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->token, 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->token, frame->pf);
			printk(KERN_DEBUG "lapb: (%p) S1 TX DM(%d)\n", lapb->token, 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->token, frame->pf);
#endif
			if (frame->pf) {
#if LAPB_DEBUG > 0
				printk(KERN_DEBUG "lapb: (%p) S1 -> S3\n", lapb->token);
#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->token, frame->pf);
#endif
			if (frame->pf) {
#if LAPB_DEBUG > 0
				printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->token);
#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;

		default:
			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(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->token, frame->pf);
			printk(KERN_DEBUG "lapb: (%p) S2 TX DM(%d)\n", lapb->token, 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->token, frame->pf);
			printk(KERN_DEBUG "lapb: (%p) S2 TX UA(%d)\n", lapb->token, 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->token, frame->pf);
#endif
			if (frame->pf) {
#if LAPB_DEBUG > 0
				printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->token);
#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->token, frame->pf);
#endif
			if (frame->pf) {
#if LAPB_DEBUG > 0
				printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->token);
#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->token, frame->pf);
			printk(KERN_DEBUG "lapb: (%p) S2 RX DM(%d)\n", lapb->token, frame->pf);
#endif
			if (frame->pf) lapb_send_control(lapb, LAPB_DM, frame->pf, LAPB_RESPONSE);
			break;
				
		default:
			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(lapb_cb *lapb, struct sk_buff *skb, struct lapb_frame *frame)
{
	int queued = 0;
	int modulus;
	
	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->token, frame->pf);
#endif
			if (lapb->mode & LAPB_EXTENDED) {
#if LAPB_DEBUG > 1
				printk(KERN_DEBUG "lapb: (%p) S3 TX DM(%d)\n", lapb->token, 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->token, 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