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/sched.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 <asm/system.h>
32 #include <linux/fcntl.h>
33 #include <linux/mm.h>
34 #include <linux/interrupt.h>
35 #include <net/lapb.h>
36
37 static void lapb_t1timer_expiry(unsigned long);
38 static void lapb_t2timer_expiry(unsigned long);
39
lapb_start_t1timer(lapb_cb * lapb)40 void lapb_start_t1timer(lapb_cb *lapb)
41 {
42 del_timer(&lapb->t1timer);
43
44 lapb->t1timer.data = (unsigned long)lapb;
45 lapb->t1timer.function = &lapb_t1timer_expiry;
46 lapb->t1timer.expires = jiffies + lapb->t1;
47
48 add_timer(&lapb->t1timer);
49 }
50
lapb_start_t2timer(lapb_cb * lapb)51 void lapb_start_t2timer(lapb_cb *lapb)
52 {
53 del_timer(&lapb->t2timer);
54
55 lapb->t2timer.data = (unsigned long)lapb;
56 lapb->t2timer.function = &lapb_t2timer_expiry;
57 lapb->t2timer.expires = jiffies + lapb->t2;
58
59 add_timer(&lapb->t2timer);
60 }
61
lapb_stop_t1timer(lapb_cb * lapb)62 void lapb_stop_t1timer(lapb_cb *lapb)
63 {
64 del_timer(&lapb->t1timer);
65 }
66
lapb_stop_t2timer(lapb_cb * lapb)67 void lapb_stop_t2timer(lapb_cb *lapb)
68 {
69 del_timer(&lapb->t2timer);
70 }
71
lapb_t1timer_running(lapb_cb * lapb)72 int lapb_t1timer_running(lapb_cb *lapb)
73 {
74 return timer_pending(&lapb->t1timer);
75 }
76
lapb_t2timer_expiry(unsigned long param)77 static void lapb_t2timer_expiry(unsigned long param)
78 {
79 lapb_cb *lapb = (lapb_cb *)param;
80
81 if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
82 lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
83 lapb_timeout_response(lapb);
84 }
85 }
86
lapb_t1timer_expiry(unsigned long param)87 static void lapb_t1timer_expiry(unsigned long param)
88 {
89 lapb_cb *lapb = (lapb_cb *)param;
90
91 switch (lapb->state) {
92
93 /*
94 * If we are a DCE, keep going DM .. DM .. DM
95 */
96 case LAPB_STATE_0:
97 if (lapb->mode & LAPB_DCE)
98 lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE);
99 break;
100
101 /*
102 * Awaiting connection state, send SABM(E), up to N2 times.
103 */
104 case LAPB_STATE_1:
105 if (lapb->n2count == lapb->n2) {
106 lapb_clear_queues(lapb);
107 lapb->state = LAPB_STATE_0;
108 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
109 #if LAPB_DEBUG > 0
110 printk(KERN_DEBUG "lapb: (%p) S1 -> S0\n", lapb->token);
111 #endif
112 return;
113 } else {
114 lapb->n2count++;
115 if (lapb->mode & LAPB_EXTENDED) {
116 #if LAPB_DEBUG > 1
117 printk(KERN_DEBUG "lapb: (%p) S1 TX SABME(1)\n", lapb->token);
118 #endif
119 lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
120 } else {
121 #if LAPB_DEBUG > 1
122 printk(KERN_DEBUG "lapb: (%p) S1 TX SABM(1)\n", lapb->token);
123 #endif
124 lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
125 }
126 }
127 break;
128
129 /*
130 * Awaiting disconnection state, send DISC, up to N2 times.
131 */
132 case LAPB_STATE_2:
133 if (lapb->n2count == lapb->n2) {
134 lapb_clear_queues(lapb);
135 lapb->state = LAPB_STATE_0;
136 lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT);
137 #if LAPB_DEBUG > 0
138 printk(KERN_DEBUG "lapb: (%p) S2 -> S0\n", lapb->token);
139 #endif
140 return;
141 } else {
142 lapb->n2count++;
143 #if LAPB_DEBUG > 1
144 printk(KERN_DEBUG "lapb: (%p) S2 TX DISC(1)\n", lapb->token);
145 #endif
146 lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
147 }
148 break;
149
150 /*
151 * Data transfer state, restransmit I frames, up to N2 times.
152 */
153 case LAPB_STATE_3:
154 if (lapb->n2count == lapb->n2) {
155 lapb_clear_queues(lapb);
156 lapb->state = LAPB_STATE_0;
157 lapb_stop_t2timer(lapb);
158 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
159 #if LAPB_DEBUG > 0
160 printk(KERN_DEBUG "lapb: (%p) S3 -> S0\n", lapb->token);
161 #endif
162 return;
163 } else {
164 lapb->n2count++;
165 lapb_requeue_frames(lapb);
166 }
167 break;
168
169 /*
170 * Frame reject state, restransmit FRMR frames, up to N2 times.
171 */
172 case LAPB_STATE_4:
173 if (lapb->n2count == lapb->n2) {
174 lapb_clear_queues(lapb);
175 lapb->state = LAPB_STATE_0;
176 lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
177 #if LAPB_DEBUG > 0
178 printk(KERN_DEBUG "lapb: (%p) S4 -> S0\n", lapb->token);
179 #endif
180 return;
181 } else {
182 lapb->n2count++;
183 lapb_transmit_frmr(lapb);
184 }
185 break;
186 }
187
188 lapb_start_t1timer(lapb);
189 }
190