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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 <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
43void ax25_ds_setup_timer(ax25_dev *ax25_dev)
44{
45 setup_timer(&ax25_dev->dama.slave_timer, ax25_ds_timeout,
46 (unsigned long)ax25_dev);
47}
48
49void ax25_ds_del_timer(ax25_dev *ax25_dev)
50{
51 if (ax25_dev)
52 del_timer(&ax25_dev->dama.slave_timer);
53}
54
55void ax25_ds_set_timer(ax25_dev *ax25_dev)
56{
57 if (ax25_dev == NULL) /* paranoia */
58 return;
59
60 ax25_dev->dama.slave_timeout =
61 msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10;
62 mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ);
63}
64
65/*
66 * DAMA Slave Timeout
67 * Silently discard all (slave) connections in case our master forgot us...
68 */
69
70static void ax25_ds_timeout(unsigned long arg)
71{
72 ax25_dev *ax25_dev = (struct ax25_dev *) arg;
73 ax25_cb *ax25;
74 struct hlist_node *node;
75
76 if (ax25_dev == NULL || !ax25_dev->dama.slave)
77 return; /* Yikes! */
78
79 if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) {
80 ax25_ds_set_timer(ax25_dev);
81 return;
82 }
83
84 spin_lock(&ax25_list_lock);
85 ax25_for_each(ax25, node, &ax25_list) {
86 if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE))
87 continue;
88
89 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
90 ax25_disconnect(ax25, ETIMEDOUT);
91 }
92 spin_unlock(&ax25_list_lock);
93
94 ax25_dev_dama_off(ax25_dev);
95}
96
97void ax25_ds_heartbeat_expiry(ax25_cb *ax25)
98{
99 struct sock *sk=ax25->sk;
100
101 if (sk)
102 bh_lock_sock(sk);
103
104 switch (ax25->state) {
105
106 case AX25_STATE_0:
107 /* Magic here: If we listen() and a new link dies before it
108 is accepted() it isn't 'dead' so doesn't get removed. */
109 if (!sk || sock_flag(sk, SOCK_DESTROY) ||
110 (sk->sk_state == TCP_LISTEN &&
111 sock_flag(sk, SOCK_DEAD))) {
112 if (sk) {
113 sock_hold(sk);
114 ax25_destroy_socket(ax25);
115 bh_unlock_sock(sk);
116 sock_put(sk);
117 } else
118 ax25_destroy_socket(ax25);
119 return;
120 }
121 break;
122
123 case AX25_STATE_3:
124 /*
125 * Check the state of the receive buffer.
126 */
127 if (sk != NULL) {
128 if (atomic_read(&sk->sk_rmem_alloc) <
129 (sk->sk_rcvbuf >> 1) &&
130 (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
131 ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
132 ax25->condition &= ~AX25_COND_ACK_PENDING;
133 break;
134 }
135 }
136 break;
137 }
138
139 if (sk)
140 bh_unlock_sock(sk);
141
142 ax25_start_heartbeat(ax25);
143}
144
145/* dl1bke 960114: T3 works much like the IDLE timeout, but
146 * gets reloaded with every frame for this
147 * connection.
148 */
149void ax25_ds_t3timer_expiry(ax25_cb *ax25)
150{
151 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
152 ax25_dama_off(ax25);
153 ax25_disconnect(ax25, ETIMEDOUT);
154}
155
156/* dl1bke 960228: close the connection when IDLE expires.
157 * unlike T3 this timer gets reloaded only on
158 * I frames.
159 */
160void ax25_ds_idletimer_expiry(ax25_cb *ax25)
161{
162 ax25_clear_queues(ax25);
163
164 ax25->n2count = 0;
165 ax25->state = AX25_STATE_2;
166
167 ax25_calculate_t1(ax25);
168 ax25_start_t1timer(ax25);
169 ax25_stop_t3timer(ax25);
170
171 if (ax25->sk != NULL) {
172 bh_lock_sock(ax25->sk);
173 ax25->sk->sk_state = TCP_CLOSE;
174 ax25->sk->sk_err = 0;
175 ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
176 if (!sock_flag(ax25->sk, SOCK_DEAD)) {
177 ax25->sk->sk_state_change(ax25->sk);
178 sock_set_flag(ax25->sk, SOCK_DEAD);
179 }
180 bh_unlock_sock(ax25->sk);
181 }
182}
183
184/* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
185 * within the poll of any connected channel. Remember
186 * that we are not allowed to send anything unless we
187 * get polled by the Master.
188 *
189 * Thus we'll have to do parts of our T1 handling in
190 * ax25_enquiry_response().
191 */
192void ax25_ds_t1_timeout(ax25_cb *ax25)
193{
194 switch (ax25->state) {
195 case AX25_STATE_1:
196 if (ax25->n2count == ax25->n2) {
197 if (ax25->modulus == AX25_MODULUS) {
198 ax25_disconnect(ax25, ETIMEDOUT);
199 return;
200 } else {
201 ax25->modulus = AX25_MODULUS;
202 ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
203 ax25->n2count = 0;
204 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
205 }
206 } else {
207 ax25->n2count++;
208 if (ax25->modulus == AX25_MODULUS)
209 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
210 else
211 ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND);
212 }
213 break;
214
215 case AX25_STATE_2:
216 if (ax25->n2count == ax25->n2) {
217 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
218 ax25_disconnect(ax25, ETIMEDOUT);
219 return;
220 } else {
221 ax25->n2count++;
222 }
223 break;
224
225 case AX25_STATE_3:
226 if (ax25->n2count == ax25->n2) {
227 ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
228 ax25_disconnect(ax25, ETIMEDOUT);
229 return;
230 } else {
231 ax25->n2count++;
232 }
233 break;
234 }
235
236 ax25_calculate_t1(ax25);
237 ax25_start_t1timer(ax25);
238}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *
4 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
5 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
6 */
7#include <linux/errno.h>
8#include <linux/types.h>
9#include <linux/socket.h>
10#include <linux/spinlock.h>
11#include <linux/in.h>
12#include <linux/kernel.h>
13#include <linux/jiffies.h>
14#include <linux/timer.h>
15#include <linux/string.h>
16#include <linux/sockios.h>
17#include <linux/net.h>
18#include <net/tcp_states.h>
19#include <net/ax25.h>
20#include <linux/inet.h>
21#include <linux/netdevice.h>
22#include <linux/skbuff.h>
23#include <net/sock.h>
24#include <linux/uaccess.h>
25#include <linux/fcntl.h>
26#include <linux/mm.h>
27#include <linux/interrupt.h>
28
29static void ax25_ds_timeout(struct timer_list *);
30
31/*
32 * Add DAMA slave timeout timer to timer list.
33 * Unlike the connection based timers the timeout function gets
34 * triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT
35 * (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in
36 * 1/10th of a second.
37 */
38
39void ax25_ds_setup_timer(ax25_dev *ax25_dev)
40{
41 timer_setup(&ax25_dev->dama.slave_timer, ax25_ds_timeout, 0);
42}
43
44void ax25_ds_del_timer(ax25_dev *ax25_dev)
45{
46 if (ax25_dev)
47 del_timer(&ax25_dev->dama.slave_timer);
48}
49
50void ax25_ds_set_timer(ax25_dev *ax25_dev)
51{
52 if (ax25_dev == NULL) /* paranoia */
53 return;
54
55 ax25_dev->dama.slave_timeout =
56 msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10;
57 mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ);
58}
59
60/*
61 * DAMA Slave Timeout
62 * Silently discard all (slave) connections in case our master forgot us...
63 */
64
65static void ax25_ds_timeout(struct timer_list *t)
66{
67 ax25_dev *ax25_dev = from_timer(ax25_dev, t, dama.slave_timer);
68 ax25_cb *ax25;
69
70 if (ax25_dev == NULL || !ax25_dev->dama.slave)
71 return; /* Yikes! */
72
73 if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) {
74 ax25_ds_set_timer(ax25_dev);
75 return;
76 }
77
78 spin_lock(&ax25_list_lock);
79 ax25_for_each(ax25, &ax25_list) {
80 if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE))
81 continue;
82
83 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
84 ax25_disconnect(ax25, ETIMEDOUT);
85 }
86 spin_unlock(&ax25_list_lock);
87
88 ax25_dev_dama_off(ax25_dev);
89}
90
91void ax25_ds_heartbeat_expiry(ax25_cb *ax25)
92{
93 struct sock *sk=ax25->sk;
94
95 if (sk)
96 bh_lock_sock(sk);
97
98 switch (ax25->state) {
99
100 case AX25_STATE_0:
101 case AX25_STATE_2:
102 /* Magic here: If we listen() and a new link dies before it
103 is accepted() it isn't 'dead' so doesn't get removed. */
104 if (!sk || sock_flag(sk, SOCK_DESTROY) ||
105 (sk->sk_state == TCP_LISTEN &&
106 sock_flag(sk, SOCK_DEAD))) {
107 if (sk) {
108 sock_hold(sk);
109 ax25_destroy_socket(ax25);
110 bh_unlock_sock(sk);
111 /* Ungrab socket and destroy it */
112 sock_put(sk);
113 } else
114 ax25_destroy_socket(ax25);
115 return;
116 }
117 break;
118
119 case AX25_STATE_3:
120 /*
121 * Check the state of the receive buffer.
122 */
123 if (sk != NULL) {
124 if (atomic_read(&sk->sk_rmem_alloc) <
125 (sk->sk_rcvbuf >> 1) &&
126 (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
127 ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
128 ax25->condition &= ~AX25_COND_ACK_PENDING;
129 break;
130 }
131 }
132 break;
133 }
134
135 if (sk)
136 bh_unlock_sock(sk);
137
138 ax25_start_heartbeat(ax25);
139}
140
141/* dl1bke 960114: T3 works much like the IDLE timeout, but
142 * gets reloaded with every frame for this
143 * connection.
144 */
145void ax25_ds_t3timer_expiry(ax25_cb *ax25)
146{
147 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
148 ax25_dama_off(ax25);
149 ax25_disconnect(ax25, ETIMEDOUT);
150}
151
152/* dl1bke 960228: close the connection when IDLE expires.
153 * unlike T3 this timer gets reloaded only on
154 * I frames.
155 */
156void ax25_ds_idletimer_expiry(ax25_cb *ax25)
157{
158 ax25_clear_queues(ax25);
159
160 ax25->n2count = 0;
161 ax25->state = AX25_STATE_2;
162
163 ax25_calculate_t1(ax25);
164 ax25_start_t1timer(ax25);
165 ax25_stop_t3timer(ax25);
166
167 if (ax25->sk != NULL) {
168 bh_lock_sock(ax25->sk);
169 ax25->sk->sk_state = TCP_CLOSE;
170 ax25->sk->sk_err = 0;
171 ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
172 if (!sock_flag(ax25->sk, SOCK_DEAD)) {
173 ax25->sk->sk_state_change(ax25->sk);
174 sock_set_flag(ax25->sk, SOCK_DEAD);
175 }
176 bh_unlock_sock(ax25->sk);
177 }
178}
179
180/* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC
181 * within the poll of any connected channel. Remember
182 * that we are not allowed to send anything unless we
183 * get polled by the Master.
184 *
185 * Thus we'll have to do parts of our T1 handling in
186 * ax25_enquiry_response().
187 */
188void ax25_ds_t1_timeout(ax25_cb *ax25)
189{
190 switch (ax25->state) {
191 case AX25_STATE_1:
192 if (ax25->n2count == ax25->n2) {
193 if (ax25->modulus == AX25_MODULUS) {
194 ax25_disconnect(ax25, ETIMEDOUT);
195 return;
196 } else {
197 ax25->modulus = AX25_MODULUS;
198 ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
199 ax25->n2count = 0;
200 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
201 }
202 } else {
203 ax25->n2count++;
204 if (ax25->modulus == AX25_MODULUS)
205 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND);
206 else
207 ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND);
208 }
209 break;
210
211 case AX25_STATE_2:
212 if (ax25->n2count == ax25->n2) {
213 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
214 if (!sock_flag(ax25->sk, SOCK_DESTROY))
215 ax25_disconnect(ax25, ETIMEDOUT);
216 return;
217 } else {
218 ax25->n2count++;
219 }
220 break;
221
222 case AX25_STATE_3:
223 if (ax25->n2count == ax25->n2) {
224 ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
225 ax25_disconnect(ax25, ETIMEDOUT);
226 return;
227 } else {
228 ax25->n2count++;
229 }
230 break;
231 }
232
233 ax25_calculate_t1(ax25);
234 ax25_start_t1timer(ax25);
235}