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
|
/*
* 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.
*/
#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/jiffies.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 <linux/uaccess.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <net/lapb.h>
static void lapb_t1timer_expiry(struct timer_list *);
static void lapb_t2timer_expiry(struct timer_list *);
void lapb_start_t1timer(struct lapb_cb *lapb)
{
del_timer(&lapb->t1timer);
lapb->t1timer.function = (TIMER_FUNC_TYPE)lapb_t1timer_expiry;
lapb->t1timer.expires = jiffies + lapb->t1;
add_timer(&lapb->t1timer);
}
void lapb_start_t2timer(struct lapb_cb *lapb)
{
del_timer(&lapb->t2timer);
lapb->t2timer.function = (TIMER_FUNC_TYPE)lapb_t2timer_expiry;
lapb->t2timer.expires = jiffies + lapb->t2;
add_timer(&lapb->t2timer);
}
void lapb_stop_t1timer(struct lapb_cb *lapb)
{
del_timer(&lapb->t1timer);
}
void lapb_stop_t2timer(struct lapb_cb *lapb)
{
del_timer(&lapb->t2timer);
}
int lapb_t1timer_running(struct lapb_cb *lapb)
{
return timer_pending(&lapb->t1timer);
}
static void lapb_t2timer_expiry(struct timer_list *t)
{
struct lapb_cb *lapb = from_timer(lapb, t, t2timer);
if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
lapb_timeout_response(lapb);
}
}
static void lapb_t1timer_expiry(struct timer_list *t)
{
struct lapb_cb *lapb = from_timer(lapb, t, t1timer);
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);
lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
return;
} else {
lapb->n2count++;
if (lapb->mode & LAPB_EXTENDED) {
lapb_dbg(1, "(%p) S1 TX SABME(1)\n",
lapb->dev);
lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
} else {
lapb_dbg(1, "(%p) S1 TX SABM(1)\n",
lapb->dev);
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);
lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
return;
} else {
lapb->n2count++;
lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb->dev);
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);
lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
return;
} else {
lapb->n2count++;
lapb_requeue_frames(lapb);
lapb_kick(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);
lapb_dbg(0, "(%p) S4 -> S0\n", lapb->dev);
return;
} else {
lapb->n2count++;
lapb_transmit_frmr(lapb);
}
break;
}
lapb_start_t1timer(lapb);
}
|
