blob: 4f44185955c790403435227d598d7c575d4880ea [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);
Ralf Baechlee1fdb5b2006-05-03 23:27:16 -070064 ax25_dev->dama.slave_timeout =
65 msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 ax25_ds_add_timer(ax25_dev);
67}
68
69/*
70 * DAMA Slave Timeout
71 * Silently discard all (slave) connections in case our master forgot us...
72 */
73
74static void ax25_ds_timeout(unsigned long arg)
75{
76 ax25_dev *ax25_dev = (struct ax25_dev *) arg;
77 ax25_cb *ax25;
78 struct hlist_node *node;
79
80 if (ax25_dev == NULL || !ax25_dev->dama.slave)
81 return; /* Yikes! */
82
83 if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) {
84 ax25_ds_set_timer(ax25_dev);
85 return;
86 }
87
Ralf Baechlec19c4b92006-07-12 13:25:23 -070088 spin_lock(&ax25_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 ax25_for_each(ax25, node, &ax25_list) {
90 if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE))
91 continue;
92
93 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
94 ax25_disconnect(ax25, ETIMEDOUT);
95 }
Ralf Baechlec19c4b92006-07-12 13:25:23 -070096 spin_unlock(&ax25_list_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98 ax25_dev_dama_off(ax25_dev);
99}
100
101void ax25_ds_heartbeat_expiry(ax25_cb *ax25)
102{
103 struct sock *sk=ax25->sk;
104
105 if (sk)
106 bh_lock_sock(sk);
107
108 switch (ax25->state) {
109
110 case AX25_STATE_0:
111 /* Magic here: If we listen() and a new link dies before it
112 is accepted() it isn't 'dead' so doesn't get removed. */
113 if (!sk || sock_flag(sk, SOCK_DESTROY) ||
114 (sk->sk_state == TCP_LISTEN &&
115 sock_flag(sk, SOCK_DEAD))) {
116 if (sk) {
117 sock_hold(sk);
118 ax25_destroy_socket(ax25);
119 sock_put(sk);
120 bh_unlock_sock(sk);
121 } else
122 ax25_destroy_socket(ax25);
123 return;
124 }
125 break;
126
127 case AX25_STATE_3:
128 /*
129 * Check the state of the receive buffer.
130 */
131 if (sk != NULL) {
132 if (atomic_read(&sk->sk_rmem_alloc) <
133 (sk->sk_rcvbuf / 2) &&
134 (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
135 ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
136 ax25->condition &= ~AX25_COND_ACK_PENDING;
137 break;
138 }
139 }
140 break;
141 }
142
143 if (sk)
144 bh_unlock_sock(sk);
145
146 ax25_start_heartbeat(ax25);
147}
148
149/* dl1bke 960114: T3 works much like the IDLE timeout, but
150 * gets reloaded with every frame for this
151 * connection.
152 */
153void ax25_ds_t3timer_expiry(ax25_cb *ax25)
154{
155 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
156 ax25_dama_off(ax25);
157 ax25_disconnect(ax25, ETIMEDOUT);
158}
159
160/* dl1bke 960228: close the connection when IDLE expires.
161 * unlike T3 this timer gets reloaded only on
162 * I frames.
163 */
164void ax25_ds_idletimer_expiry(ax25_cb *ax25)
165{
166 ax25_clear_queues(ax25);
167
168 ax25->n2count = 0;
169 ax25->state = AX25_STATE_2;
170
171 ax25_calculate_t1(ax25);
172 ax25_start_t1timer(ax25);
173 ax25_stop_t3timer(ax25);
174
175 if (ax25->sk != NULL) {
176 bh_lock_sock(ax25->sk);
177 ax25->sk->sk_state = TCP_CLOSE;
178 ax25->sk->sk_err = 0;
179 ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
180 if (!sock_flag(ax25->sk, SOCK_DEAD)) {
181 ax25->sk->sk_state_change(ax25->sk);
182 sock_set_flag(ax25->sk, SOCK_DEAD);
183 }
184 bh_unlock_sock(ax25->sk);
185 }
186}
187
188/* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
189 * within the poll of any connected channel. Remember
190 * that we are not allowed to send anything unless we
191 * get polled by the Master.
192 *
193 * Thus we'll have to do parts of our T1 handling in
194 * ax25_enquiry_response().
195 */
196void ax25_ds_t1_timeout(ax25_cb *ax25)
197{
198 switch (ax25->state) {
199 case AX25_STATE_1:
200 if (ax25->n2count == ax25->n2) {
201 if (ax25->modulus == AX25_MODULUS) {
202 ax25_disconnect(ax25, ETIMEDOUT);
203 return;
204 } else {
205 ax25->modulus = AX25_MODULUS;
206 ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
207 ax25->n2count = 0;
208 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
209 }
210 } else {
211 ax25->n2count++;
212 if (ax25->modulus == AX25_MODULUS)
213 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
214 else
215 ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND);
216 }
217 break;
218
219 case AX25_STATE_2:
220 if (ax25->n2count == ax25->n2) {
221 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
222 ax25_disconnect(ax25, ETIMEDOUT);
223 return;
224 } else {
225 ax25->n2count++;
226 }
227 break;
228
229 case AX25_STATE_3:
230 if (ax25->n2count == ax25->n2) {
231 ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
232 ax25_disconnect(ax25, ETIMEDOUT);
233 return;
234 } else {
235 ax25->n2count++;
236 }
237 break;
238 }
239
240 ax25_calculate_t1(ax25);
241 ax25_start_t1timer(ax25);
242}