1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
8 * Copyright (C) 2002 Ralf Baechle DO1GRB (ralf@gnu.org)
9 */
10#include <linux/errno.h>
11#include <linux/types.h>
12#include <linux/socket.h>
13#include <linux/in.h>
14#include <linux/kernel.h>
15#include <linux/jiffies.h>
16#include <linux/timer.h>
17#include <linux/string.h>
18#include <linux/sockios.h>
19#include <linux/net.h>
20#include <net/ax25.h>
21#include <linux/inet.h>
22#include <linux/netdevice.h>
23#include <linux/skbuff.h>
24#include <net/sock.h>
25#include <net/tcp_states.h>
26#include <asm/system.h>
27#include <linux/fcntl.h>
28#include <linux/mm.h>
29#include <linux/interrupt.h>
30#include <net/rose.h>
31
32static void rose_heartbeat_expiry(unsigned long);
33static void rose_timer_expiry(unsigned long);
34static void rose_idletimer_expiry(unsigned long);
35
36void rose_start_heartbeat(struct sock *sk)
37{
38	del_timer(&sk->sk_timer);
39
40	sk->sk_timer.data     = (unsigned long)sk;
41	sk->sk_timer.function = &rose_heartbeat_expiry;
42	sk->sk_timer.expires  = jiffies + 5 * HZ;
43
44	add_timer(&sk->sk_timer);
45}
46
47void rose_start_t1timer(struct sock *sk)
48{
49	struct rose_sock *rose = rose_sk(sk);
50
51	del_timer(&rose->timer);
52
53	rose->timer.data     = (unsigned long)sk;
54	rose->timer.function = &rose_timer_expiry;
55	rose->timer.expires  = jiffies + rose->t1;
56
57	add_timer(&rose->timer);
58}
59
60void rose_start_t2timer(struct sock *sk)
61{
62	struct rose_sock *rose = rose_sk(sk);
63
64	del_timer(&rose->timer);
65
66	rose->timer.data     = (unsigned long)sk;
67	rose->timer.function = &rose_timer_expiry;
68	rose->timer.expires  = jiffies + rose->t2;
69
70	add_timer(&rose->timer);
71}
72
73void rose_start_t3timer(struct sock *sk)
74{
75	struct rose_sock *rose = rose_sk(sk);
76
77	del_timer(&rose->timer);
78
79	rose->timer.data     = (unsigned long)sk;
80	rose->timer.function = &rose_timer_expiry;
81	rose->timer.expires  = jiffies + rose->t3;
82
83	add_timer(&rose->timer);
84}
85
86void rose_start_hbtimer(struct sock *sk)
87{
88	struct rose_sock *rose = rose_sk(sk);
89
90	del_timer(&rose->timer);
91
92	rose->timer.data     = (unsigned long)sk;
93	rose->timer.function = &rose_timer_expiry;
94	rose->timer.expires  = jiffies + rose->hb;
95
96	add_timer(&rose->timer);
97}
98
99void rose_start_idletimer(struct sock *sk)
100{
101	struct rose_sock *rose = rose_sk(sk);
102
103	del_timer(&rose->idletimer);
104
105	if (rose->idle > 0) {
106		rose->idletimer.data     = (unsigned long)sk;
107		rose->idletimer.function = &rose_idletimer_expiry;
108		rose->idletimer.expires  = jiffies + rose->idle;
109
110		add_timer(&rose->idletimer);
111	}
112}
113
114void rose_stop_heartbeat(struct sock *sk)
115{
116	del_timer(&sk->sk_timer);
117}
118
119void rose_stop_timer(struct sock *sk)
120{
121	del_timer(&rose_sk(sk)->timer);
122}
123
124void rose_stop_idletimer(struct sock *sk)
125{
126	del_timer(&rose_sk(sk)->idletimer);
127}
128
129static void rose_heartbeat_expiry(unsigned long param)
130{
131	struct sock *sk = (struct sock *)param;
132	struct rose_sock *rose = rose_sk(sk);
133
134	bh_lock_sock(sk);
135	switch (rose->state) {
136	case ROSE_STATE_0:
137		/* Magic here: If we listen() and a new link dies before it
138		   is accepted() it isn't 'dead' so doesn't get removed. */
139		if (sock_flag(sk, SOCK_DESTROY) ||
140		    (sk->sk_state == TCP_LISTEN && sock_flag(sk, SOCK_DEAD))) {
141			bh_unlock_sock(sk);
142			rose_destroy_socket(sk);
143			return;
144		}
145		break;
146
147	case ROSE_STATE_3:
148		/*
149		 * Check for the state of the receive buffer.
150		 */
151		if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) &&
152		    (rose->condition & ROSE_COND_OWN_RX_BUSY)) {
153			rose->condition &= ~ROSE_COND_OWN_RX_BUSY;
154			rose->condition &= ~ROSE_COND_ACK_PENDING;
155			rose->vl         = rose->vr;
156			rose_write_internal(sk, ROSE_RR);
157			rose_stop_timer(sk);	/* HB */
158			break;
159		}
160		break;
161	}
162
163	rose_start_heartbeat(sk);
164	bh_unlock_sock(sk);
165}
166
167static void rose_timer_expiry(unsigned long param)
168{
169	struct sock *sk = (struct sock *)param;
170	struct rose_sock *rose = rose_sk(sk);
171
172	bh_lock_sock(sk);
173	switch (rose->state) {
174	case ROSE_STATE_1:	/* T1 */
175	case ROSE_STATE_4:	/* T2 */
176		rose_write_internal(sk, ROSE_CLEAR_REQUEST);
177		rose->state = ROSE_STATE_2;
178		rose_start_t3timer(sk);
179		break;
180
181	case ROSE_STATE_2:	/* T3 */
182		rose->neighbour->use--;
183		rose_disconnect(sk, ETIMEDOUT, -1, -1);
184		break;
185
186	case ROSE_STATE_3:	/* HB */
187		if (rose->condition & ROSE_COND_ACK_PENDING) {
188			rose->condition &= ~ROSE_COND_ACK_PENDING;
189			rose_enquiry_response(sk);
190		}
191		break;
192	}
193	bh_unlock_sock(sk);
194}
195
196static void rose_idletimer_expiry(unsigned long param)
197{
198	struct sock *sk = (struct sock *)param;
199
200	bh_lock_sock(sk);
201	rose_clear_queues(sk);
202
203	rose_write_internal(sk, ROSE_CLEAR_REQUEST);
204	rose_sk(sk)->state = ROSE_STATE_2;
205
206	rose_start_t3timer(sk);
207
208	sk->sk_state     = TCP_CLOSE;
209	sk->sk_err       = 0;
210	sk->sk_shutdown |= SEND_SHUTDOWN;
211
212	if (!sock_flag(sk, SOCK_DEAD)) {
213		sk->sk_state_change(sk);
214		sock_set_flag(sk, SOCK_DEAD);
215	}
216	bh_unlock_sock(sk);
217}
218