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1da177e4 LT |
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> | |
c752f073 | 21 | #include <net/tcp_states.h> |
1da177e4 LT |
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 | ||
33 | static 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 | ||
43 | static 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 | ||
52 | void ax25_ds_del_timer(ax25_dev *ax25_dev) | |
53 | { | |
54 | if (ax25_dev) | |
55 | del_timer(&ax25_dev->dama.slave_timer); | |
56 | } | |
57 | ||
58 | void 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 | ||
73 | static 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 | ||
100 | void 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 | */ | |
152 | void 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 | */ | |
163 | void 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 | */ | |
195 | void 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 | } |