blob: 061083efc1dcddc70cf900fbc43e77b69bfafa41 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Arnaldo Carvalho de Meloc752f072005-08-09 20:08:28 -070021#include <net/tcp_states.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#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 <asm/system.h>
29#include <linux/fcntl.h>
30#include <linux/mm.h>
31#include <linux/interrupt.h>
32
33static void ax25_ds_timeout(unsigned long);
34
35/*
36 * Add DAMA slave timeout timer to timer list.
37 * Unlike the connection based timers the timeout function gets
38 * triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT
39 * (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in
40 * 1/10th of a second.
41 */
42
43static void ax25_ds_add_timer(ax25_dev *ax25_dev)
44{
45 struct timer_list *t = &ax25_dev->dama.slave_timer;
46 t->data = (unsigned long) ax25_dev;
47 t->function = &ax25_ds_timeout;
48 t->expires = jiffies + HZ;
49 add_timer(t);
50}
51
52void ax25_ds_del_timer(ax25_dev *ax25_dev)
53{
54 if (ax25_dev)
55 del_timer(&ax25_dev->dama.slave_timer);
56}
57
58void ax25_ds_set_timer(ax25_dev *ax25_dev)
59{
60 if (ax25_dev == NULL) /* paranoia */
61 return;
62
63 del_timer(&ax25_dev->dama.slave_timer);
64 ax25_dev->dama.slave_timeout = ax25_dev->values[AX25_VALUES_DS_TIMEOUT] / 10;
65 ax25_ds_add_timer(ax25_dev);
66}
67
68/*
69 * DAMA Slave Timeout
70 * Silently discard all (slave) connections in case our master forgot us...
71 */
72
73static void ax25_ds_timeout(unsigned long arg)
74{
75 ax25_dev *ax25_dev = (struct ax25_dev *) arg;
76 ax25_cb *ax25;
77 struct hlist_node *node;
78
79 if (ax25_dev == NULL || !ax25_dev->dama.slave)
80 return; /* Yikes! */
81
82 if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) {
83 ax25_ds_set_timer(ax25_dev);
84 return;
85 }
86
87 spin_lock_bh(&ax25_list_lock);
88 ax25_for_each(ax25, node, &ax25_list) {
89 if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE))
90 continue;
91
92 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
93 ax25_disconnect(ax25, ETIMEDOUT);
94 }
95 spin_unlock_bh(&ax25_list_lock);
96
97 ax25_dev_dama_off(ax25_dev);
98}
99
100void ax25_ds_heartbeat_expiry(ax25_cb *ax25)
101{
102 struct sock *sk=ax25->sk;
103
104 if (sk)
105 bh_lock_sock(sk);
106
107 switch (ax25->state) {
108
109 case AX25_STATE_0:
110 /* Magic here: If we listen() and a new link dies before it
111 is accepted() it isn't 'dead' so doesn't get removed. */
112 if (!sk || sock_flag(sk, SOCK_DESTROY) ||
113 (sk->sk_state == TCP_LISTEN &&
114 sock_flag(sk, SOCK_DEAD))) {
115 if (sk) {
116 sock_hold(sk);
117 ax25_destroy_socket(ax25);
118 sock_put(sk);
119 bh_unlock_sock(sk);
120 } else
121 ax25_destroy_socket(ax25);
122 return;
123 }
124 break;
125
126 case AX25_STATE_3:
127 /*
128 * Check the state of the receive buffer.
129 */
130 if (sk != NULL) {
131 if (atomic_read(&sk->sk_rmem_alloc) <
132 (sk->sk_rcvbuf / 2) &&
133 (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
134 ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
135 ax25->condition &= ~AX25_COND_ACK_PENDING;
136 break;
137 }
138 }
139 break;
140 }
141
142 if (sk)
143 bh_unlock_sock(sk);
144
145 ax25_start_heartbeat(ax25);
146}
147
148/* dl1bke 960114: T3 works much like the IDLE timeout, but
149 * gets reloaded with every frame for this
150 * connection.
151 */
152void ax25_ds_t3timer_expiry(ax25_cb *ax25)
153{
154 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
155 ax25_dama_off(ax25);
156 ax25_disconnect(ax25, ETIMEDOUT);
157}
158
159/* dl1bke 960228: close the connection when IDLE expires.
160 * unlike T3 this timer gets reloaded only on
161 * I frames.
162 */
163void ax25_ds_idletimer_expiry(ax25_cb *ax25)
164{
165 ax25_clear_queues(ax25);
166
167 ax25->n2count = 0;
168 ax25->state = AX25_STATE_2;
169
170 ax25_calculate_t1(ax25);
171 ax25_start_t1timer(ax25);
172 ax25_stop_t3timer(ax25);
173
174 if (ax25->sk != NULL) {
175 bh_lock_sock(ax25->sk);
176 ax25->sk->sk_state = TCP_CLOSE;
177 ax25->sk->sk_err = 0;
178 ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
179 if (!sock_flag(ax25->sk, SOCK_DEAD)) {
180 ax25->sk->sk_state_change(ax25->sk);
181 sock_set_flag(ax25->sk, SOCK_DEAD);
182 }
183 bh_unlock_sock(ax25->sk);
184 }
185}
186
187/* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
188 * within the poll of any connected channel. Remember
189 * that we are not allowed to send anything unless we
190 * get polled by the Master.
191 *
192 * Thus we'll have to do parts of our T1 handling in
193 * ax25_enquiry_response().
194 */
195void ax25_ds_t1_timeout(ax25_cb *ax25)
196{
197 switch (ax25->state) {
198 case AX25_STATE_1:
199 if (ax25->n2count == ax25->n2) {
200 if (ax25->modulus == AX25_MODULUS) {
201 ax25_disconnect(ax25, ETIMEDOUT);
202 return;
203 } else {
204 ax25->modulus = AX25_MODULUS;
205 ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
206 ax25->n2count = 0;
207 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
208 }
209 } else {
210 ax25->n2count++;
211 if (ax25->modulus == AX25_MODULUS)
212 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
213 else
214 ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND);
215 }
216 break;
217
218 case AX25_STATE_2:
219 if (ax25->n2count == ax25->n2) {
220 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
221 ax25_disconnect(ax25, ETIMEDOUT);
222 return;
223 } else {
224 ax25->n2count++;
225 }
226 break;
227
228 case AX25_STATE_3:
229 if (ax25->n2count == ax25->n2) {
230 ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
231 ax25_disconnect(ax25, ETIMEDOUT);
232 return;
233 } else {
234 ax25->n2count++;
235 }
236 break;
237 }
238
239 ax25_calculate_t1(ax25);
240 ax25_start_t1timer(ax25);
241}