306 lines
7.1 KiB
C
306 lines
7.1 KiB
C
|
/*
|
|||
|
|
* 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.
|
|||
|
|
*
|
|||
|
|
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
|
|||
|
|
* Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
|
|||
|
|
*/
|
|||
|
|
#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 <net/ax25.h>
|
|||
|
|
#include <linux/inet.h>
|
|||
|
|
#include <linux/netdevice.h>
|
|||
|
|
#include <linux/skbuff.h>
|
|||
|
|
#include <net/sock.h>
|
|||
|
|
#include <net/ip.h> /* For ip_rcv */
|
|||
|
|
#include <net/tcp.h>
|
|||
|
|
#include <asm/uaccess.h>
|
|||
|
|
#include <asm/system.h>
|
|||
|
|
#include <linux/fcntl.h>
|
|||
|
|
#include <linux/mm.h>
|
|||
|
|
#include <linux/interrupt.h>
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* State machine for state 1, Awaiting Connection State.
|
|||
|
|
* The handling of the timer(s) is in file ax25_ds_timer.c.
|
|||
|
|
* Handling of state 0 and connection release is in ax25.c.
|
|||
|
|
*/
|
|||
|
|
static int ax25_ds_state1_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type)
|
|||
|
|
{
|
|||
|
|
switch (frametype) {
|
|||
|
|
case AX25_SABM:
|
|||
|
|
ax25->modulus = AX25_MODULUS;
|
|||
|
|
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
|
|||
|
|
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_SABME:
|
|||
|
|
ax25->modulus = AX25_EMODULUS;
|
|||
|
|
ax25->window = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
|
|||
|
|
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_DISC:
|
|||
|
|
ax25_send_control(ax25, AX25_DM, pf, AX25_RESPONSE);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_UA:
|
|||
|
|
ax25_calculate_rtt(ax25);
|
|||
|
|
ax25_stop_t1timer(ax25);
|
|||
|
|
ax25_start_t3timer(ax25);
|
|||
|
|
ax25_start_idletimer(ax25);
|
|||
|
|
ax25->vs = 0;
|
|||
|
|
ax25->va = 0;
|
|||
|
|
ax25->vr = 0;
|
|||
|
|
ax25->state = AX25_STATE_3;
|
|||
|
|
ax25->n2count = 0;
|
|||
|
|
if (ax25->sk != NULL) {
|
|||
|
|
bh_lock_sock(ax25->sk);
|
|||
|
|
ax25->sk->sk_state = TCP_ESTABLISHED;
|
|||
|
|
/*
|
|||
|
|
* For WAIT_SABM connections we will produce an accept
|
|||
|
|
* ready socket here
|
|||
|
|
*/
|
|||
|
|
if (!sock_flag(ax25->sk, SOCK_DEAD))
|
|||
|
|
ax25->sk->sk_state_change(ax25->sk);
|
|||
|
|
bh_unlock_sock(ax25->sk);
|
|||
|
|
}
|
|||
|
|
ax25_dama_on(ax25);
|
|||
|
|
|
|||
|
|
/* according to DK4EG<45>s spec we are required to
|
|||
|
|
* send a RR RESPONSE FINAL NR=0.
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
ax25_std_enquiry_response(ax25);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_DM:
|
|||
|
|
if (pf)
|
|||
|
|
ax25_disconnect(ax25, ECONNREFUSED);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
default:
|
|||
|
|
if (pf)
|
|||
|
|
ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
|
|||
|
|
break;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return 0;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* State machine for state 2, Awaiting Release State.
|
|||
|
|
* The handling of the timer(s) is in file ax25_ds_timer.c
|
|||
|
|
* Handling of state 0 and connection release is in ax25.c.
|
|||
|
|
*/
|
|||
|
|
static int ax25_ds_state2_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int pf, int type)
|
|||
|
|
{
|
|||
|
|
switch (frametype) {
|
|||
|
|
case AX25_SABM:
|
|||
|
|
case AX25_SABME:
|
|||
|
|
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
|
|||
|
|
ax25_dama_off(ax25);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_DISC:
|
|||
|
|
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
|||
|
|
ax25_dama_off(ax25);
|
|||
|
|
ax25_disconnect(ax25, 0);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_DM:
|
|||
|
|
case AX25_UA:
|
|||
|
|
if (pf) {
|
|||
|
|
ax25_dama_off(ax25);
|
|||
|
|
ax25_disconnect(ax25, 0);
|
|||
|
|
}
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_I:
|
|||
|
|
case AX25_REJ:
|
|||
|
|
case AX25_RNR:
|
|||
|
|
case AX25_RR:
|
|||
|
|
if (pf) {
|
|||
|
|
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
|
|||
|
|
ax25_dama_off(ax25);
|
|||
|
|
}
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
default:
|
|||
|
|
break;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return 0;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* State machine for state 3, Connected State.
|
|||
|
|
* The handling of the timer(s) is in file ax25_timer.c
|
|||
|
|
* Handling of state 0 and connection release is in ax25.c.
|
|||
|
|
*/
|
|||
|
|
static int ax25_ds_state3_machine(ax25_cb *ax25, struct sk_buff *skb, int frametype, int ns, int nr, int pf, int type)
|
|||
|
|
{
|
|||
|
|
int queued = 0;
|
|||
|
|
|
|||
|
|
switch (frametype) {
|
|||
|
|
case AX25_SABM:
|
|||
|
|
case AX25_SABME:
|
|||
|
|
if (frametype == AX25_SABM) {
|
|||
|
|
ax25->modulus = AX25_MODULUS;
|
|||
|
|
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
|
|||
|
|
} else {
|
|||
|
|
ax25->modulus = AX25_EMODULUS;
|
|||
|
|
ax25->window = ax25->ax25_dev->values[AX25_VALUES_EWINDOW];
|
|||
|
|
}
|
|||
|
|
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
|||
|
|
ax25_stop_t1timer(ax25);
|
|||
|
|
ax25_start_t3timer(ax25);
|
|||
|
|
ax25_start_idletimer(ax25);
|
|||
|
|
ax25->condition = 0x00;
|
|||
|
|
ax25->vs = 0;
|
|||
|
|
ax25->va = 0;
|
|||
|
|
ax25->vr = 0;
|
|||
|
|
ax25_requeue_frames(ax25);
|
|||
|
|
ax25_dama_on(ax25);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_DISC:
|
|||
|
|
ax25_send_control(ax25, AX25_UA, pf, AX25_RESPONSE);
|
|||
|
|
ax25_dama_off(ax25);
|
|||
|
|
ax25_disconnect(ax25, 0);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_DM:
|
|||
|
|
ax25_dama_off(ax25);
|
|||
|
|
ax25_disconnect(ax25, ECONNRESET);
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_RR:
|
|||
|
|
case AX25_RNR:
|
|||
|
|
if (frametype == AX25_RR)
|
|||
|
|
ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
|
|||
|
|
else
|
|||
|
|
ax25->condition |= AX25_COND_PEER_RX_BUSY;
|
|||
|
|
|
|||
|
|
if (ax25_validate_nr(ax25, nr)) {
|
|||
|
|
if (ax25_check_iframes_acked(ax25, nr))
|
|||
|
|
ax25->n2count=0;
|
|||
|
|
if (type == AX25_COMMAND && pf)
|
|||
|
|
ax25_ds_enquiry_response(ax25);
|
|||
|
|
} else {
|
|||
|
|
ax25_ds_nr_error_recovery(ax25);
|
|||
|
|
ax25->state = AX25_STATE_1;
|
|||
|
|
}
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_REJ:
|
|||
|
|
ax25->condition &= ~AX25_COND_PEER_RX_BUSY;
|
|||
|
|
|
|||
|
|
if (ax25_validate_nr(ax25, nr)) {
|
|||
|
|
if (ax25->va != nr)
|
|||
|
|
ax25->n2count=0;
|
|||
|
|
|
|||
|
|
ax25_frames_acked(ax25, nr);
|
|||
|
|
ax25_calculate_rtt(ax25);
|
|||
|
|
ax25_stop_t1timer(ax25);
|
|||
|
|
ax25_start_t3timer(ax25);
|
|||
|
|
ax25_requeue_frames(ax25);
|
|||
|
|
|
|||
|
|
if (type == AX25_COMMAND && pf)
|
|||
|
|
ax25_ds_enquiry_response(ax25);
|
|||
|
|
} else {
|
|||
|
|
ax25_ds_nr_error_recovery(ax25);
|
|||
|
|
ax25->state = AX25_STATE_1;
|
|||
|
|
}
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_I:
|
|||
|
|
if (!ax25_validate_nr(ax25, nr)) {
|
|||
|
|
ax25_ds_nr_error_recovery(ax25);
|
|||
|
|
ax25->state = AX25_STATE_1;
|
|||
|
|
break;
|
|||
|
|
}
|
|||
|
|
if (ax25->condition & AX25_COND_PEER_RX_BUSY) {
|
|||
|
|
ax25_frames_acked(ax25, nr);
|
|||
|
|
ax25->n2count = 0;
|
|||
|
|
} else {
|
|||
|
|
if (ax25_check_iframes_acked(ax25, nr))
|
|||
|
|
ax25->n2count = 0;
|
|||
|
|
}
|
|||
|
|
if (ax25->condition & AX25_COND_OWN_RX_BUSY) {
|
|||
|
|
if (pf) ax25_ds_enquiry_response(ax25);
|
|||
|
|
break;
|
|||
|
|
}
|
|||
|
|
if (ns == ax25->vr) {
|
|||
|
|
ax25->vr = (ax25->vr + 1) % ax25->modulus;
|
|||
|
|
queued = ax25_rx_iframe(ax25, skb);
|
|||
|
|
if (ax25->condition & AX25_COND_OWN_RX_BUSY)
|
|||
|
|
ax25->vr = ns; /* ax25->vr - 1 */
|
|||
|
|
ax25->condition &= ~AX25_COND_REJECT;
|
|||
|
|
if (pf) {
|
|||
|
|
ax25_ds_enquiry_response(ax25);
|
|||
|
|
} else {
|
|||
|
|
if (!(ax25->condition & AX25_COND_ACK_PENDING)) {
|
|||
|
|
ax25->condition |= AX25_COND_ACK_PENDING;
|
|||
|
|
ax25_start_t2timer(ax25);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
} else {
|
|||
|
|
if (ax25->condition & AX25_COND_REJECT) {
|
|||
|
|
if (pf) ax25_ds_enquiry_response(ax25);
|
|||
|
|
} else {
|
|||
|
|
ax25->condition |= AX25_COND_REJECT;
|
|||
|
|
ax25_ds_enquiry_response(ax25);
|
|||
|
|
ax25->condition &= ~AX25_COND_ACK_PENDING;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
case AX25_FRMR:
|
|||
|
|
case AX25_ILLEGAL:
|
|||
|
|
ax25_ds_establish_data_link(ax25);
|
|||
|
|
ax25->state = AX25_STATE_1;
|
|||
|
|
break;
|
|||
|
|
|
|||
|
|
default:
|
|||
|
|
break;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return queued;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/*
|
|||
|
|
* Higher level upcall for a LAPB frame
|
|||
|
|
*/
|
|||
|
|
int ax25_ds_frame_in(ax25_cb *ax25, struct sk_buff *skb, int type)
|
|||
|
|
{
|
|||
|
|
int queued = 0, frametype, ns, nr, pf;
|
|||
|
|
|
|||
|
|
frametype = ax25_decode(ax25, skb, &ns, &nr, &pf);
|
|||
|
|
|
|||
|
|
switch (ax25->state) {
|
|||
|
|
case AX25_STATE_1:
|
|||
|
|
queued = ax25_ds_state1_machine(ax25, skb, frametype, pf, type);
|
|||
|
|
break;
|
|||
|
|
case AX25_STATE_2:
|
|||
|
|
queued = ax25_ds_state2_machine(ax25, skb, frametype, pf, type);
|
|||
|
|
break;
|
|||
|
|
case AX25_STATE_3:
|
|||
|
|
queued = ax25_ds_state3_machine(ax25, skb, frametype, ns, nr, pf, type);
|
|||
|
|
break;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return queued;
|
|||
|
|
}
|
|||
|
|
|