Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[platform/adaptation/renesas_rcar/renesas_kernel.git] / net / ax25 / ax25_ds_timer.c
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) Joerg Reuter DL1BKE (jreuter@yaina.de)
9  */
10 #include <linux/errno.h>
11 #include <linux/types.h>
12 #include <linux/socket.h>
13 #include <linux/spinlock.h>
14 #include <linux/in.h>
15 #include <linux/kernel.h>
16 #include <linux/jiffies.h>
17 #include <linux/timer.h>
18 #include <linux/string.h>
19 #include <linux/sockios.h>
20 #include <linux/net.h>
21 #include <net/tcp_states.h>
22 #include <net/ax25.h>
23 #include <linux/inet.h>
24 #include <linux/netdevice.h>
25 #include <linux/skbuff.h>
26 #include <net/sock.h>
27 #include <asm/uaccess.h>
28 #include <linux/fcntl.h>
29 #include <linux/mm.h>
30 #include <linux/interrupt.h>
31
32 static void ax25_ds_timeout(unsigned long);
33
34 /*
35  *      Add DAMA slave timeout timer to timer list.
36  *      Unlike the connection based timers the timeout function gets
37  *      triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT
38  *      (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in
39  *      1/10th of a second.
40  */
41
42 void ax25_ds_setup_timer(ax25_dev *ax25_dev)
43 {
44         setup_timer(&ax25_dev->dama.slave_timer, ax25_ds_timeout,
45                     (unsigned long)ax25_dev);
46 }
47
48 void ax25_ds_del_timer(ax25_dev *ax25_dev)
49 {
50         if (ax25_dev)
51                 del_timer(&ax25_dev->dama.slave_timer);
52 }
53
54 void ax25_ds_set_timer(ax25_dev *ax25_dev)
55 {
56         if (ax25_dev == NULL)           /* paranoia */
57                 return;
58
59         ax25_dev->dama.slave_timeout =
60                 msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10;
61         mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ);
62 }
63
64 /*
65  *      DAMA Slave Timeout
66  *      Silently discard all (slave) connections in case our master forgot us...
67  */
68
69 static void ax25_ds_timeout(unsigned long arg)
70 {
71         ax25_dev *ax25_dev = (struct ax25_dev *) arg;
72         ax25_cb *ax25;
73
74         if (ax25_dev == NULL || !ax25_dev->dama.slave)
75                 return;                 /* Yikes! */
76
77         if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) {
78                 ax25_ds_set_timer(ax25_dev);
79                 return;
80         }
81
82         spin_lock(&ax25_list_lock);
83         ax25_for_each(ax25, &ax25_list) {
84                 if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE))
85                         continue;
86
87                 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
88                 ax25_disconnect(ax25, ETIMEDOUT);
89         }
90         spin_unlock(&ax25_list_lock);
91
92         ax25_dev_dama_off(ax25_dev);
93 }
94
95 void ax25_ds_heartbeat_expiry(ax25_cb *ax25)
96 {
97         struct sock *sk=ax25->sk;
98
99         if (sk)
100                 bh_lock_sock(sk);
101
102         switch (ax25->state) {
103
104         case AX25_STATE_0:
105                 /* Magic here: If we listen() and a new link dies before it
106                    is accepted() it isn't 'dead' so doesn't get removed. */
107                 if (!sk || sock_flag(sk, SOCK_DESTROY) ||
108                     (sk->sk_state == TCP_LISTEN &&
109                      sock_flag(sk, SOCK_DEAD))) {
110                         if (sk) {
111                                 sock_hold(sk);
112                                 ax25_destroy_socket(ax25);
113                                 bh_unlock_sock(sk);
114                                 sock_put(sk);
115                         } else
116                                 ax25_destroy_socket(ax25);
117                         return;
118                 }
119                 break;
120
121         case AX25_STATE_3:
122                 /*
123                  * Check the state of the receive buffer.
124                  */
125                 if (sk != NULL) {
126                         if (atomic_read(&sk->sk_rmem_alloc) <
127                             (sk->sk_rcvbuf >> 1) &&
128                             (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
129                                 ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
130                                 ax25->condition &= ~AX25_COND_ACK_PENDING;
131                                 break;
132                         }
133                 }
134                 break;
135         }
136
137         if (sk)
138                 bh_unlock_sock(sk);
139
140         ax25_start_heartbeat(ax25);
141 }
142
143 /* dl1bke 960114: T3 works much like the IDLE timeout, but
144  *                gets reloaded with every frame for this
145  *                connection.
146  */
147 void ax25_ds_t3timer_expiry(ax25_cb *ax25)
148 {
149         ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
150         ax25_dama_off(ax25);
151         ax25_disconnect(ax25, ETIMEDOUT);
152 }
153
154 /* dl1bke 960228: close the connection when IDLE expires.
155  *                unlike T3 this timer gets reloaded only on
156  *                I frames.
157  */
158 void ax25_ds_idletimer_expiry(ax25_cb *ax25)
159 {
160         ax25_clear_queues(ax25);
161
162         ax25->n2count = 0;
163         ax25->state = AX25_STATE_2;
164
165         ax25_calculate_t1(ax25);
166         ax25_start_t1timer(ax25);
167         ax25_stop_t3timer(ax25);
168
169         if (ax25->sk != NULL) {
170                 bh_lock_sock(ax25->sk);
171                 ax25->sk->sk_state     = TCP_CLOSE;
172                 ax25->sk->sk_err       = 0;
173                 ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
174                 if (!sock_flag(ax25->sk, SOCK_DEAD)) {
175                         ax25->sk->sk_state_change(ax25->sk);
176                         sock_set_flag(ax25->sk, SOCK_DEAD);
177                 }
178                 bh_unlock_sock(ax25->sk);
179         }
180 }
181
182 /* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
183  *                within the poll of any connected channel. Remember
184  *                that we are not allowed to send anything unless we
185  *                get polled by the Master.
186  *
187  *                Thus we'll have to do parts of our T1 handling in
188  *                ax25_enquiry_response().
189  */
190 void ax25_ds_t1_timeout(ax25_cb *ax25)
191 {
192         switch (ax25->state) {
193         case AX25_STATE_1:
194                 if (ax25->n2count == ax25->n2) {
195                         if (ax25->modulus == AX25_MODULUS) {
196                                 ax25_disconnect(ax25, ETIMEDOUT);
197                                 return;
198                         } else {
199                                 ax25->modulus = AX25_MODULUS;
200                                 ax25->window  = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
201                                 ax25->n2count = 0;
202                                 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
203                         }
204                 } else {
205                         ax25->n2count++;
206                         if (ax25->modulus == AX25_MODULUS)
207                                 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
208                         else
209                                 ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND);
210                 }
211                 break;
212
213         case AX25_STATE_2:
214                 if (ax25->n2count == ax25->n2) {
215                         ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
216                         ax25_disconnect(ax25, ETIMEDOUT);
217                         return;
218                 } else {
219                         ax25->n2count++;
220                 }
221                 break;
222
223         case AX25_STATE_3:
224                 if (ax25->n2count == ax25->n2) {
225                         ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
226                         ax25_disconnect(ax25, ETIMEDOUT);
227                         return;
228                 } else {
229                         ax25->n2count++;
230                 }
231                 break;
232         }
233
234         ax25_calculate_t1(ax25);
235         ax25_start_t1timer(ax25);
236 }