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gerrit-public.fairphone.software / kernel / msm / a380a8849f90ba81a5ff0c325fd5d8125c70b3bb / . / net / ax25 / ax25_std_timer.c
blob: 066897bc074901965b83487c30e850ee27adc105 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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) Alan Cox GW4PTS (alan@lxorguk.ukuu.org.uk)
8 * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
9 * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de)
10 * Copyright (C) Frederic Rible F1OAT (frible@teaser.fr)
11 */
12#include <linux/errno.h>
13#include <linux/types.h>
14#include <linux/socket.h>
15#include <linux/in.h>
16#include <linux/kernel.h>
17#include <linux/sched.h>
18#include <linux/timer.h>
19#include <linux/string.h>
20#include <linux/sockios.h>
21#include <linux/net.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 <net/tcp.h>
28#include <asm/uaccess.h>
29#include <asm/system.h>
30#include <linux/fcntl.h>
31#include <linux/mm.h>
32#include <linux/interrupt.h>
33
34void ax25_std_heartbeat_expiry(ax25_cb *ax25)
35{
36 struct sock *sk=ax25->sk;
37
38 if (sk)
39 bh_lock_sock(sk);
40
41 switch (ax25->state) {
42 case AX25_STATE_0:
43 /* Magic here: If we listen() and a new link dies before it
44 is accepted() it isn't 'dead' so doesn't get removed. */
45 if (!sk || sock_flag(sk, SOCK_DESTROY) ||
46 (sk->sk_state == TCP_LISTEN &&
47 sock_flag(sk, SOCK_DEAD))) {
48 if (sk) {
49 sock_hold(sk);
50 ax25_destroy_socket(ax25);
51 bh_unlock_sock(sk);
52 sock_put(sk);
53 } else
54 ax25_destroy_socket(ax25);
55 return;
56 }
57 break;
58
59 case AX25_STATE_3:
60 case AX25_STATE_4:
61 /*
62 * Check the state of the receive buffer.
63 */
64 if (sk != NULL) {
65 if (atomic_read(&sk->sk_rmem_alloc) <
66 (sk->sk_rcvbuf / 2) &&
67 (ax25->condition & AX25_COND_OWN_RX_BUSY)) {
68 ax25->condition &= ~AX25_COND_OWN_RX_BUSY;
69 ax25->condition &= ~AX25_COND_ACK_PENDING;
70 ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE);
71 break;
72 }
73 }
74 }
75
76 if (sk)
77 bh_unlock_sock(sk);
78
79 ax25_start_heartbeat(ax25);
80}
81
82void ax25_std_t2timer_expiry(ax25_cb *ax25)
83{
84 if (ax25->condition & AX25_COND_ACK_PENDING) {
85 ax25->condition &= ~AX25_COND_ACK_PENDING;
86 ax25_std_timeout_response(ax25);
87 }
88}
89
90void ax25_std_t3timer_expiry(ax25_cb *ax25)
91{
92 ax25->n2count = 0;
93 ax25_std_transmit_enquiry(ax25);
94 ax25->state = AX25_STATE_4;
95}
96
97void ax25_std_idletimer_expiry(ax25_cb *ax25)
98{
99 ax25_clear_queues(ax25);
100
101 ax25->n2count = 0;
102 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
103 ax25->state = AX25_STATE_2;
104
105 ax25_calculate_t1(ax25);
106 ax25_start_t1timer(ax25);
107 ax25_stop_t2timer(ax25);
108 ax25_stop_t3timer(ax25);
109
110 if (ax25->sk != NULL) {
111 bh_lock_sock(ax25->sk);
112 ax25->sk->sk_state = TCP_CLOSE;
113 ax25->sk->sk_err = 0;
114 ax25->sk->sk_shutdown |= SEND_SHUTDOWN;
115 if (!sock_flag(ax25->sk, SOCK_DEAD)) {
116 ax25->sk->sk_state_change(ax25->sk);
117 sock_set_flag(ax25->sk, SOCK_DEAD);
118 }
119 bh_unlock_sock(ax25->sk);
120 }
121}
122
123void ax25_std_t1timer_expiry(ax25_cb *ax25)
124{
125 switch (ax25->state) {
126 case AX25_STATE_1:
127 if (ax25->n2count == ax25->n2) {
128 if (ax25->modulus == AX25_MODULUS) {
129 ax25_disconnect(ax25, ETIMEDOUT);
130 return;
131 } else {
132 ax25->modulus = AX25_MODULUS;
133 ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW];
134 ax25->n2count = 0;
135 ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
136 }
137 } else {
138 ax25->n2count++;
139 if (ax25->modulus == AX25_MODULUS)
140 ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND);
141 else
142 ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND);
143 }
144 break;
145
146 case AX25_STATE_2:
147 if (ax25->n2count == ax25->n2) {
148 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
149 ax25_disconnect(ax25, ETIMEDOUT);
150 return;
151 } else {
152 ax25->n2count++;
153 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND);
154 }
155 break;
156
157 case AX25_STATE_3:
158 ax25->n2count = 1;
159 ax25_std_transmit_enquiry(ax25);
160 ax25->state = AX25_STATE_4;
161 break;
162
163 case AX25_STATE_4:
164 if (ax25->n2count == ax25->n2) {
165 ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE);
166 ax25_disconnect(ax25, ETIMEDOUT);
167 return;
168 } else {
169 ax25->n2count++;
170 ax25_std_transmit_enquiry(ax25);
171 }
172 break;
173 }
174
175 ax25_calculate_t1(ax25);
176 ax25_start_t1timer(ax25);
177}