Linux kernel mirror (for testing)
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linux
1/*
2 * LAPB release 002
3 *
4 * This code REQUIRES 2.1.15 or higher/ NET3.038
5 *
6 * This module:
7 * This module is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 *
12 * History
13 * LAPB 001 Jonathan Naylor Started Coding
14 * LAPB 002 Jonathan Naylor New timer architecture.
15 */
16
17#include <linux/errno.h>
18#include <linux/types.h>
19#include <linux/socket.h>
20#include <linux/in.h>
21#include <linux/kernel.h>
22#include <linux/jiffies.h>
23#include <linux/timer.h>
24#include <linux/string.h>
25#include <linux/sockios.h>
26#include <linux/net.h>
27#include <linux/inet.h>
28#include <linux/skbuff.h>
29#include <net/sock.h>
30#include <asm/uaccess.h>
31#include <linux/fcntl.h>
32#include <linux/mm.h>
33#include <linux/interrupt.h>
34#include <net/lapb.h>
35
36static void lapb_t1timer_expiry(unsigned long);
37static void lapb_t2timer_expiry(unsigned long);
38
39void lapb_start_t1timer(struct lapb_cb *lapb)
40{
41 del_timer(&lapb->t1timer);
42
43 lapb->t1timer.data = (unsigned long)lapb;
44 lapb->t1timer.function = &lapb_t1timer_expiry;
45 lapb->t1timer.expires = jiffies + lapb->t1;
46
47 add_timer(&lapb->t1timer);
48}
49
50void lapb_start_t2timer(struct lapb_cb *lapb)
51{
52 del_timer(&lapb->t2timer);
53
54 lapb->t2timer.data = (unsigned long)lapb;
55 lapb->t2timer.function = &lapb_t2timer_expiry;
56 lapb->t2timer.expires = jiffies + lapb->t2;
57
58 add_timer(&lapb->t2timer);
59}
60
61void lapb_stop_t1timer(struct lapb_cb *lapb)
62{
63 del_timer(&lapb->t1timer);
64}
65
66void lapb_stop_t2timer(struct lapb_cb *lapb)
67{
68 del_timer(&lapb->t2timer);
69}
70
71int lapb_t1timer_running(struct lapb_cb *lapb)
72{
73 return timer_pending(&lapb->t1timer);
74}
75
76static void lapb_t2timer_expiry(unsigned long param)
77{
78 struct lapb_cb *lapb = (struct lapb_cb *)param;
79
80 if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
81 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
82 lapb_timeout_response(lapb);
83 }
84}
85
86static void lapb_t1timer_expiry(unsigned long param)
87{
88 struct lapb_cb *lapb = (struct lapb_cb *)param;
89
90 switch (lapb->state) {
91
92 /*
93 * If we are a DCE, keep going DM .. DM .. DM
94 */
95 case LAPB_STATE_0:
96 if (lapb->mode & LAPB_DCE)
97 lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE);
98 break;
99
100 /*
101 * Awaiting connection state, send SABM(E), up to N2 times.
102 */
103 case LAPB_STATE_1:
104 if (lapb->n2count == lapb->n2) {
105 lapb_clear_queues(lapb);
106 lapb->state = LAPB_STATE_0;
107 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
108#if LAPB_DEBUG > 0
109 printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->dev);
110#endif
111 return;
112 } else {
113 lapb->n2count++;
114 if (lapb->mode & LAPB_EXTENDED) {
115#if LAPB_DEBUG > 1
116 printk(KERN_DEBUG "lapb: (%p) S1 TX SABME(1)\n", lapb->dev);
117#endif
118 lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
119 } else {
120#if LAPB_DEBUG > 1
121 printk(KERN_DEBUG "lapb: (%p) S1 TX SABM(1)\n", lapb->dev);
122#endif
123 lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
124 }
125 }
126 break;
127
128 /*
129 * Awaiting disconnection state, send DISC, up to N2 times.
130 */
131 case LAPB_STATE_2:
132 if (lapb->n2count == lapb->n2) {
133 lapb_clear_queues(lapb);
134 lapb->state = LAPB_STATE_0;
135 lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT);
136#if LAPB_DEBUG > 0
137 printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->dev);
138#endif
139 return;
140 } else {
141 lapb->n2count++;
142#if LAPB_DEBUG > 1
143 printk(KERN_DEBUG "lapb: (%p) S2 TX DISC(1)\n", lapb->dev);
144#endif
145 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
146 }
147 break;
148
149 /*
150 * Data transfer state, restransmit I frames, up to N2 times.
151 */
152 case LAPB_STATE_3:
153 if (lapb->n2count == lapb->n2) {
154 lapb_clear_queues(lapb);
155 lapb->state = LAPB_STATE_0;
156 lapb_stop_t2timer(lapb);
157 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
158#if LAPB_DEBUG > 0
159 printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->dev);
160#endif
161 return;
162 } else {
163 lapb->n2count++;
164 lapb_requeue_frames(lapb);
165 }
166 break;
167
168 /*
169 * Frame reject state, restransmit FRMR frames, up to N2 times.
170 */
171 case LAPB_STATE_4:
172 if (lapb->n2count == lapb->n2) {
173 lapb_clear_queues(lapb);
174 lapb->state = LAPB_STATE_0;
175 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
176#if LAPB_DEBUG > 0
177 printk(KERN_DEBUG "lapb: (%p) S4 -> S0\n", lapb->dev);
178#endif
179 return;
180 } else {
181 lapb->n2count++;
182 lapb_transmit_frmr(lapb);
183 }
184 break;
185 }
186
187 lapb_start_t1timer(lapb);
188}