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> 21 #include <net/tcp_states.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 <asm/uaccess.h> 28 #include <linux/fcntl.h> 29 #include <linux/mm.h> 30 #include <linux/interrupt.h> 31 32 static void ax25_ds_timeout(unsigned long); 33 34 /* 35 * Add DAMA slave timeout timer to timer list. 36 * Unlike the connection based timers the timeout function gets 37 * triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT 38 * (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in 39 * 1/10th of a second. 40 */ 41 42 void ax25_ds_setup_timer(ax25_dev *ax25_dev) 43 { 44 setup_timer(&ax25_dev->dama.slave_timer, ax25_ds_timeout, 45 (unsigned long)ax25_dev); 46 } 47 48 void ax25_ds_del_timer(ax25_dev *ax25_dev) 49 { 50 if (ax25_dev) 51 del_timer(&ax25_dev->dama.slave_timer); 52 } 53 54 void ax25_ds_set_timer(ax25_dev *ax25_dev) 55 { 56 if (ax25_dev == NULL) /* paranoia */ 57 return; 58 59 ax25_dev->dama.slave_timeout = 60 msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10; 61 mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ); 62 } 63 64 /* 65 * DAMA Slave Timeout 66 * Silently discard all (slave) connections in case our master forgot us... 67 */ 68 69 static void ax25_ds_timeout(unsigned long arg) 70 { 71 ax25_dev *ax25_dev = (struct ax25_dev *) arg; 72 ax25_cb *ax25; 73 74 if (ax25_dev == NULL || !ax25_dev->dama.slave) 75 return; /* Yikes! */ 76 77 if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) { 78 ax25_ds_set_timer(ax25_dev); 79 return; 80 } 81 82 spin_lock(&ax25_list_lock); 83 ax25_for_each(ax25, &ax25_list) { 84 if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE)) 85 continue; 86 87 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); 88 ax25_disconnect(ax25, ETIMEDOUT); 89 } 90 spin_unlock(&ax25_list_lock); 91 92 ax25_dev_dama_off(ax25_dev); 93 } 94 95 void ax25_ds_heartbeat_expiry(ax25_cb *ax25) 96 { 97 struct sock *sk=ax25->sk; 98 99 if (sk) 100 bh_lock_sock(sk); 101 102 switch (ax25->state) { 103 104 case AX25_STATE_0: 105 /* Magic here: If we listen() and a new link dies before it 106 is accepted() it isn't 'dead' so doesn't get removed. */ 107 if (!sk || sock_flag(sk, SOCK_DESTROY) || 108 (sk->sk_state == TCP_LISTEN && 109 sock_flag(sk, SOCK_DEAD))) { 110 if (sk) { 111 sock_hold(sk); 112 ax25_destroy_socket(ax25); 113 bh_unlock_sock(sk); 114 sock_put(sk); 115 } else 116 ax25_destroy_socket(ax25); 117 return; 118 } 119 break; 120 121 case AX25_STATE_3: 122 /* 123 * Check the state of the receive buffer. 124 */ 125 if (sk != NULL) { 126 if (atomic_read(&sk->sk_rmem_alloc) < 127 (sk->sk_rcvbuf >> 1) && 128 (ax25->condition & AX25_COND_OWN_RX_BUSY)) { 129 ax25->condition &= ~AX25_COND_OWN_RX_BUSY; 130 ax25->condition &= ~AX25_COND_ACK_PENDING; 131 break; 132 } 133 } 134 break; 135 } 136 137 if (sk) 138 bh_unlock_sock(sk); 139 140 ax25_start_heartbeat(ax25); 141 } 142 143 /* dl1bke 960114: T3 works much like the IDLE timeout, but 144 * gets reloaded with every frame for this 145 * connection. 146 */ 147 void ax25_ds_t3timer_expiry(ax25_cb *ax25) 148 { 149 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); 150 ax25_dama_off(ax25); 151 ax25_disconnect(ax25, ETIMEDOUT); 152 } 153 154 /* dl1bke 960228: close the connection when IDLE expires. 155 * unlike T3 this timer gets reloaded only on 156 * I frames. 157 */ 158 void ax25_ds_idletimer_expiry(ax25_cb *ax25) 159 { 160 ax25_clear_queues(ax25); 161 162 ax25->n2count = 0; 163 ax25->state = AX25_STATE_2; 164 165 ax25_calculate_t1(ax25); 166 ax25_start_t1timer(ax25); 167 ax25_stop_t3timer(ax25); 168 169 if (ax25->sk != NULL) { 170 bh_lock_sock(ax25->sk); 171 ax25->sk->sk_state = TCP_CLOSE; 172 ax25->sk->sk_err = 0; 173 ax25->sk->sk_shutdown |= SEND_SHUTDOWN; 174 if (!sock_flag(ax25->sk, SOCK_DEAD)) { 175 ax25->sk->sk_state_change(ax25->sk); 176 sock_set_flag(ax25->sk, SOCK_DEAD); 177 } 178 bh_unlock_sock(ax25->sk); 179 } 180 } 181 182 /* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC 183 * within the poll of any connected channel. Remember 184 * that we are not allowed to send anything unless we 185 * get polled by the Master. 186 * 187 * Thus we'll have to do parts of our T1 handling in 188 * ax25_enquiry_response(). 189 */ 190 void ax25_ds_t1_timeout(ax25_cb *ax25) 191 { 192 switch (ax25->state) { 193 case AX25_STATE_1: 194 if (ax25->n2count == ax25->n2) { 195 if (ax25->modulus == AX25_MODULUS) { 196 ax25_disconnect(ax25, ETIMEDOUT); 197 return; 198 } else { 199 ax25->modulus = AX25_MODULUS; 200 ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW]; 201 ax25->n2count = 0; 202 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND); 203 } 204 } else { 205 ax25->n2count++; 206 if (ax25->modulus == AX25_MODULUS) 207 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND); 208 else 209 ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND); 210 } 211 break; 212 213 case AX25_STATE_2: 214 if (ax25->n2count == ax25->n2) { 215 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); 216 ax25_disconnect(ax25, ETIMEDOUT); 217 return; 218 } else { 219 ax25->n2count++; 220 } 221 break; 222 223 case AX25_STATE_3: 224 if (ax25->n2count == ax25->n2) { 225 ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE); 226 ax25_disconnect(ax25, ETIMEDOUT); 227 return; 228 } else { 229 ax25->n2count++; 230 } 231 break; 232 } 233 234 ax25_calculate_t1(ax25); 235 ax25_start_t1timer(ax25); 236 } 237