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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 | 2 | /* |
1da177e4 LT |
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> | |
c752f073 | 18 | #include <net/tcp_states.h> |
1da177e4 LT |
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> | |
7c0f6ba6 | 24 | #include <linux/uaccess.h> |
1da177e4 LT |
25 | #include <linux/fcntl.h> |
26 | #include <linux/mm.h> | |
27 | #include <linux/interrupt.h> | |
28 | ||
8dbd05ff | 29 | static void ax25_ds_timeout(struct timer_list *); |
1da177e4 LT |
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 | ||
e848b583 | 39 | void ax25_ds_setup_timer(ax25_dev *ax25_dev) |
1da177e4 | 40 | { |
8dbd05ff | 41 | timer_setup(&ax25_dev->dama.slave_timer, ax25_ds_timeout, 0); |
1da177e4 LT |
42 | } |
43 | ||
44 | void ax25_ds_del_timer(ax25_dev *ax25_dev) | |
45 | { | |
46 | if (ax25_dev) | |
47 | del_timer(&ax25_dev->dama.slave_timer); | |
48 | } | |
49 | ||
50 | void ax25_ds_set_timer(ax25_dev *ax25_dev) | |
51 | { | |
52 | if (ax25_dev == NULL) /* paranoia */ | |
53 | return; | |
54 | ||
e1fdb5b3 RB |
55 | ax25_dev->dama.slave_timeout = |
56 | msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10; | |
e848b583 | 57 | mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ); |
1da177e4 LT |
58 | } |
59 | ||
60 | /* | |
61 | * DAMA Slave Timeout | |
62 | * Silently discard all (slave) connections in case our master forgot us... | |
63 | */ | |
64 | ||
8dbd05ff | 65 | static void ax25_ds_timeout(struct timer_list *t) |
1da177e4 | 66 | { |
8dbd05ff | 67 | ax25_dev *ax25_dev = from_timer(ax25_dev, t, dama.slave_timer); |
1da177e4 | 68 | ax25_cb *ax25; |
1da177e4 LT |
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 | ||
c19c4b9c | 78 | spin_lock(&ax25_list_lock); |
b67bfe0d | 79 | ax25_for_each(ax25, &ax25_list) { |
1da177e4 LT |
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 | } | |
c19c4b9c | 86 | spin_unlock(&ax25_list_lock); |
1da177e4 LT |
87 | |
88 | ax25_dev_dama_off(ax25_dev); | |
89 | } | |
90 | ||
91 | void 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: | |
4a7d99ea | 101 | case AX25_STATE_2: |
1da177e4 LT |
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); | |
1da177e4 | 110 | bh_unlock_sock(sk); |
4a7d99ea | 111 | /* Ungrab socket and destroy it */ |
d71b0e9c | 112 | sock_put(sk); |
1da177e4 LT |
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) < | |
f16f3026 | 125 | (sk->sk_rcvbuf >> 1) && |
1da177e4 LT |
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 | */ | |
145 | void 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 | */ | |
156 | void 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 | */ | |
188 | void 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); | |
4a7d99ea BG |
214 | if (!sock_flag(ax25->sk, SOCK_DESTROY)) |
215 | ax25_disconnect(ax25, ETIMEDOUT); | |
1da177e4 LT |
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 | } |