[NET] rules: Share common attribute validation policy
[linux-2.6.git] / net / ax25 / ax25_std_timer.c
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_states.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
34 void 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
82 void 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
90 void 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
97 void 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
123 void 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 }