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
178
179
180
181
182
183
184
185
186
187
188
189
|
/*
* 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 Naylor Started Coding
* LAPB 002 Jonathan Naylor New timer architecture.
*/
#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/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>
static void lapb_t1timer_expiry(unsigned long);
static void lapb_t2timer_expiry(unsigned long);
void lapb_start_t1timer(lapb_cb *lapb)
{
del_timer(&lapb->t1timer);
lapb->t1timer.data = (unsigned long)lapb;
lapb->t1timer.function = &lapb_t1timer_expiry;
lapb->t1timer.expires = jiffies + lapb->t1;
add_timer(&lapb->t1timer);
}
void lapb_start_t2timer(lapb_cb *lapb)
{
del_timer(&lapb->t2timer);
lapb->t2timer.data = (unsigned long)lapb;
lapb->t2timer.function = &lapb_t2timer_expiry;
lapb->t2timer.expires = jiffies + lapb->t2;
add_timer(&lapb->t2timer);
}
void lapb_stop_t1timer(lapb_cb *lapb)
{
del_timer(&lapb->t1timer);
}
void lapb_stop_t2timer(lapb_cb *lapb)
{
del_timer(&lapb->t2timer);
}
int lapb_t1timer_running(lapb_cb *lapb)
{
return timer_pending(&lapb->t1timer);
}
static void lapb_t2timer_expiry(unsigned long param)
{
lapb_cb *lapb = (lapb_cb *)param;
if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
lapb_timeout_response(lapb);
}
}
static void lapb_t1timer_expiry(unsigned long param)
{
lapb_cb *lapb = (lapb_cb *)param;
switch (lapb->state) {
/*
* If we are a DCE, keep going DM .. DM .. DM
*/
case LAPB_STATE_0:
if (lapb->mode & LAPB_DCE)
lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE);
break;
/*
* Awaiting connection state, send SABM(E), up to N2 times.
*/
case LAPB_STATE_1:
if (lapb->n2count == lapb->n2) {
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
#if LAPB_DEBUG > 0
printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->token);
#endif
return;
} else {
lapb->n2count++;
if (lapb->mode & LAPB_EXTENDED) {
#if LAPB_DEBUG > 1
printk(KERN_DEBUG "lapb: (%p) S1 TX SABME(1)\n", lapb->token);
#endif
lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
} else {
#if LAPB_DEBUG > 1
printk(KERN_DEBUG "lapb: (%p) S1 TX SABM(1)\n", lapb->token);
#endif
lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
}
}
break;
/*
* Awaiting disconnection state, send DISC, up to N2 times.
*/
case LAPB_STATE_2:
if (lapb->n2count == lapb->n2) {
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT);
#if LAPB_DEBUG > 0
printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->token);
#endif
return;
} else {
lapb->n2count++;
#if LAPB_DEBUG > 1
printk(KERN_DEBUG "lapb: (%p) S2 TX DISC(1)\n", lapb->token);
#endif
lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
}
break;
/*
* Data transfer state, restransmit I frames, up to N2 times.
*/
case LAPB_STATE_3:
if (lapb->n2count == lapb->n2) {
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb_stop_t2timer(lapb);
lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
#if LAPB_DEBUG > 0
printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->token);
#endif
return;
} else {
lapb->n2count++;
lapb_requeue_frames(lapb);
}
break;
/*
* Frame reject state, restransmit FRMR frames, up to N2 times.
*/
case LAPB_STATE_4:
if (lapb->n2count == lapb->n2) {
lapb_clear_queues(lapb);
lapb->state = LAPB_STATE_0;
lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
#if LAPB_DEBUG > 0
printk(KERN_DEBUG "lapb: (%p) S4 -> S0\n", lapb->token);
#endif
return;
} else {
lapb->n2count++;
lapb_transmit_frmr(lapb);
}
break;
}
lapb_start_t1timer(lapb);
}
|
