1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/*
* 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) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
* Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
* Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
* Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
*/
#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/tcp_states.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
void ax25_std_heartbeat_expiry(ax25_cb *ax25)
{
struct sock *sk=ax25->sk;
if (sk)
bh_lock_sock(sk);
switch (ax25->state) {
case AX25_STATE_0:
/* Magic here: If we listen() and a new link dies before it
is accepted() it isn't 'dead' so doesn't get removed. */
if (!sk || sock_flag(sk, SOCK_DESTROY) ||
(sk->sk_state == TCP_LISTEN &&
sock_flag(sk, SOCK_DEAD))) {
if (sk) {
sock_hold(sk);
ax25_destroy_socket(ax25);
bh_unlock_sock(sk);
sock_put(sk);
} else
ax25_destroy_socket(ax25);
return;
}
break;
case AX25_STATE_3:
case AX25_STATE_4:
/*
* Check the state of the receive buffer.
*/
if (sk != NULL) {
if (atomic_read(&sk->sk_rmem_alloc) <
(sk->sk_rcvbuf / 2) &&
(ax25->condition & AX25_COND_OWN_RX_BUSY)) {
ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
ax25->condition &= ~AX25_COND_ACK_PENDING;
ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
break;
}
}
}
if (sk)
bh_unlock_sock(sk);
ax25_start_heartbeat(ax25);
}
void ax25_std_t2timer_expiry(ax25_cb *ax25)
{
if (ax25->condition & AX25_COND_ACK_PENDING) {
ax25->condition &= ~AX25_COND_ACK_PENDING;
ax25_std_timeout_response(ax25);
}
}
void ax25_std_t3timer_expiry(ax25_cb *ax25)
{
ax25->n2count = 0;
ax25_std_transmit_enquiry(ax25);
ax25->state = AX25_STATE_4;
}
void ax25_std_idletimer_expiry(ax25_cb *ax25)
{
ax25_clear_queues(ax25);
ax25->n2count = 0;
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
ax25->state = AX25_STATE_2;
ax25_calculate_t1(ax25);
ax25_start_t1timer(ax25);
ax25_stop_t2timer(ax25);
ax25_stop_t3timer(ax25);
if (ax25->sk != NULL) {
bh_lock_sock(ax25->sk);
ax25->sk->sk_state = TCP_CLOSE;
ax25->sk->sk_err = 0;
ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
if (!sock_flag(ax25->sk, SOCK_DEAD)) {
ax25->sk->sk_state_change(ax25->sk);
sock_set_flag(ax25->sk, SOCK_DEAD);
}
bh_unlock_sock(ax25->sk);
}
}
void ax25_std_t1timer_expiry(ax25_cb *ax25)
{
switch (ax25->state) {
case AX25_STATE_1:
if (ax25->n2count == ax25->n2) {
if (ax25->modulus == AX25_MODULUS) {
ax25_disconnect(ax25, ETIMEDOUT);
return;
} else {
ax25->modulus = AX25_MODULUS;
ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
ax25->n2count = 0;
ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
}
} else {
ax25->n2count++;
if (ax25->modulus == AX25_MODULUS)
ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
else
ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND);
}
break;
case AX25_STATE_2:
if (ax25->n2count == ax25->n2) {
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
ax25_disconnect(ax25, ETIMEDOUT);
return;
} else {
ax25->n2count++;
ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
}
break;
case AX25_STATE_3:
ax25->n2count = 1;
ax25_std_transmit_enquiry(ax25);
ax25->state = AX25_STATE_4;
break;
case AX25_STATE_4:
if (ax25->n2count == ax25->n2) {
ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
ax25_disconnect(ax25, ETIMEDOUT);
return;
} else {
ax25->n2count++;
ax25_std_transmit_enquiry(ax25);
}
break;
}
ax25_calculate_t1(ax25);
ax25_start_t1timer(ax25);
}
|
