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