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 <asm/system.h>
32#include <linux/fcntl.h>
33#include <linux/mm.h>
34#include <linux/interrupt.h>
35#include <net/lapb.h>
36
37static void lapb_t1timer_expiry(unsigned long);
38static void lapb_t2timer_expiry(unsigned long);
39
40void lapb_start_t1timer(struct 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
51void lapb_start_t2timer(struct 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
62void lapb_stop_t1timer(struct lapb_cb *lapb)
63{
64	del_timer(&lapb->t1timer);
65}
66
67void lapb_stop_t2timer(struct lapb_cb *lapb)
68{
69	del_timer(&lapb->t2timer);
70}
71
72int lapb_t1timer_running(struct lapb_cb *lapb)
73{
74	return timer_pending(&lapb->t1timer);
75}
76
77static void lapb_t2timer_expiry(unsigned long param)
78{
79	struct lapb_cb *lapb = (struct 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
87static void lapb_t1timer_expiry(unsigned long param)
88{
89	struct lapb_cb *lapb = (struct 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->dev);
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->dev);
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->dev);
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->dev);
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->dev);
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->dev);
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->dev);
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