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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}
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
32static 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
42void 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
48void ax25_ds_del_timer(ax25_dev *ax25_dev)
49{
50 if (ax25_dev)
51 del_timer(&ax25_dev->dama.slave_timer);
52}
53
54void 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
69static 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
95void 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 */
147void 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 */
158void 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 */
190void 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}