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 
32 static void rose_heartbeat_expiry(unsigned long);
33 static void rose_timer_expiry(unsigned long);
34 static void rose_idletimer_expiry(unsigned long);
35 
rose_start_heartbeat(struct sock * sk)36 void 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 
rose_start_t1timer(struct sock * sk)47 void 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 
rose_start_t2timer(struct sock * sk)60 void 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 
rose_start_t3timer(struct sock * sk)73 void 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 
rose_start_hbtimer(struct sock * sk)86 void 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 
rose_start_idletimer(struct sock * sk)99 void 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 
rose_stop_heartbeat(struct sock * sk)114 void rose_stop_heartbeat(struct sock *sk)
115 {
116 	del_timer(&sk->sk_timer);
117 }
118 
rose_stop_timer(struct sock * sk)119 void rose_stop_timer(struct sock *sk)
120 {
121 	del_timer(&rose_sk(sk)->timer);
122 }
123 
rose_stop_idletimer(struct sock * sk)124 void rose_stop_idletimer(struct sock *sk)
125 {
126 	del_timer(&rose_sk(sk)->idletimer);
127 }
128 
rose_heartbeat_expiry(unsigned long param)129 static 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 
rose_timer_expiry(unsigned long param)167 static 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 
rose_idletimer_expiry(unsigned long param)196 static 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