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/timer.h> 18 #include <linux/string.h> 19 #include <linux/sockios.h> 20 #include <linux/net.h> 21 #include <net/ax25.h> 22 #include <linux/inet.h> 23 #include <linux/netdevice.h> 24 #include <linux/skbuff.h> 25 #include <net/sock.h> 26 #include <net/tcp_states.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 void ax25_std_heartbeat_expiry(ax25_cb *ax25) 34 { 35 struct sock *sk = ax25->sk; 36 37 if (sk) 38 bh_lock_sock(sk); 39 40 switch (ax25->state) { 41 case AX25_STATE_0: 42 if (!sk || 43 sock_flag(sk, SOCK_DESTROY) || 44 sock_flag(sk, SOCK_DEAD)) { 45 if (sk) { 46 sock_hold(sk); 47 ax25_destroy_socket(ax25); 48 bh_unlock_sock(sk); 49 sock_put(sk); 50 } else 51 ax25_destroy_socket(ax25); 52 return; 53 } 54 break; 55 56 case AX25_STATE_3: 57 case AX25_STATE_4: 58 /* 59 * Check the state of the receive buffer. 60 */ 61 if (sk != NULL) { 62 if (atomic_read(&sk->sk_rmem_alloc) < 63 (sk->sk_rcvbuf >> 1) && 64 (ax25->condition & AX25_COND_OWN_RX_BUSY)) { 65 ax25->condition &= ~AX25_COND_OWN_RX_BUSY; 66 ax25->condition &= ~AX25_COND_ACK_PENDING; 67 ax25_send_control(ax25, AX25_RR, AX25_POLLOFF, AX25_RESPONSE); 68 break; 69 } 70 } 71 } 72 73 if (sk) 74 bh_unlock_sock(sk); 75 76 ax25_start_heartbeat(ax25); 77 } 78 79 void ax25_std_t2timer_expiry(ax25_cb *ax25) 80 { 81 if (ax25->condition & AX25_COND_ACK_PENDING) { 82 ax25->condition &= ~AX25_COND_ACK_PENDING; 83 ax25_std_timeout_response(ax25); 84 } 85 } 86 87 void ax25_std_t3timer_expiry(ax25_cb *ax25) 88 { 89 ax25->n2count = 0; 90 ax25_std_transmit_enquiry(ax25); 91 ax25->state = AX25_STATE_4; 92 } 93 94 void ax25_std_idletimer_expiry(ax25_cb *ax25) 95 { 96 ax25_clear_queues(ax25); 97 98 ax25->n2count = 0; 99 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); 100 ax25->state = AX25_STATE_2; 101 102 ax25_calculate_t1(ax25); 103 ax25_start_t1timer(ax25); 104 ax25_stop_t2timer(ax25); 105 ax25_stop_t3timer(ax25); 106 107 if (ax25->sk != NULL) { 108 bh_lock_sock(ax25->sk); 109 ax25->sk->sk_state = TCP_CLOSE; 110 ax25->sk->sk_err = 0; 111 ax25->sk->sk_shutdown |= SEND_SHUTDOWN; 112 if (!sock_flag(ax25->sk, SOCK_DEAD)) { 113 ax25->sk->sk_state_change(ax25->sk); 114 sock_set_flag(ax25->sk, SOCK_DEAD); 115 } 116 bh_unlock_sock(ax25->sk); 117 } 118 } 119 120 void ax25_std_t1timer_expiry(ax25_cb *ax25) 121 { 122 switch (ax25->state) { 123 case AX25_STATE_1: 124 if (ax25->n2count == ax25->n2) { 125 if (ax25->modulus == AX25_MODULUS) { 126 ax25_disconnect(ax25, ETIMEDOUT); 127 return; 128 } else { 129 ax25->modulus = AX25_MODULUS; 130 ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW]; 131 ax25->n2count = 0; 132 ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND); 133 } 134 } else { 135 ax25->n2count++; 136 if (ax25->modulus == AX25_MODULUS) 137 ax25_send_control(ax25, AX25_SABM, AX25_POLLON, AX25_COMMAND); 138 else 139 ax25_send_control(ax25, AX25_SABME, AX25_POLLON, AX25_COMMAND); 140 } 141 break; 142 143 case AX25_STATE_2: 144 if (ax25->n2count == ax25->n2) { 145 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); 146 ax25_disconnect(ax25, ETIMEDOUT); 147 return; 148 } else { 149 ax25->n2count++; 150 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); 151 } 152 break; 153 154 case AX25_STATE_3: 155 ax25->n2count = 1; 156 ax25_std_transmit_enquiry(ax25); 157 ax25->state = AX25_STATE_4; 158 break; 159 160 case AX25_STATE_4: 161 if (ax25->n2count == ax25->n2) { 162 ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE); 163 ax25_disconnect(ax25, ETIMEDOUT); 164 return; 165 } else { 166 ax25->n2count++; 167 ax25_std_transmit_enquiry(ax25); 168 } 169 break; 170 } 171 172 ax25_calculate_t1(ax25); 173 ax25_start_t1timer(ax25); 174 } 175