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 <linux/uaccess.h> 28 #include <linux/fcntl.h> 29 #include <linux/mm.h> 30 #include <linux/interrupt.h> 31 32 static void ax25_ds_timeout(struct timer_list *); 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 timer_setup(&ax25_dev->dama.slave_timer, ax25_ds_timeout, 0); 45 } 46 47 void ax25_ds_del_timer(ax25_dev *ax25_dev) 48 { 49 if (ax25_dev) 50 del_timer(&ax25_dev->dama.slave_timer); 51 } 52 53 void ax25_ds_set_timer(ax25_dev *ax25_dev) 54 { 55 if (ax25_dev == NULL) /* paranoia */ 56 return; 57 58 ax25_dev->dama.slave_timeout = 59 msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10; 60 mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ); 61 } 62 63 /* 64 * DAMA Slave Timeout 65 * Silently discard all (slave) connections in case our master forgot us... 66 */ 67 68 static void ax25_ds_timeout(struct timer_list *t) 69 { 70 ax25_dev *ax25_dev = from_timer(ax25_dev, t, dama.slave_timer); 71 ax25_cb *ax25; 72 73 if (ax25_dev == NULL || !ax25_dev->dama.slave) 74 return; /* Yikes! */ 75 76 if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) { 77 ax25_ds_set_timer(ax25_dev); 78 return; 79 } 80 81 spin_lock(&ax25_list_lock); 82 ax25_for_each(ax25, &ax25_list) { 83 if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE)) 84 continue; 85 86 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); 87 ax25_disconnect(ax25, ETIMEDOUT); 88 } 89 spin_unlock(&ax25_list_lock); 90 91 ax25_dev_dama_off(ax25_dev); 92 } 93 94 void ax25_ds_heartbeat_expiry(ax25_cb *ax25) 95 { 96 struct sock *sk=ax25->sk; 97 98 if (sk) 99 bh_lock_sock(sk); 100 101 switch (ax25->state) { 102 103 case AX25_STATE_0: 104 case AX25_STATE_2: 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 /* Ungrab socket and destroy it */ 115 sock_put(sk); 116 } else 117 ax25_destroy_socket(ax25); 118 return; 119 } 120 break; 121 122 case AX25_STATE_3: 123 /* 124 * Check the state of the receive buffer. 125 */ 126 if (sk != NULL) { 127 if (atomic_read(&sk->sk_rmem_alloc) < 128 (sk->sk_rcvbuf >> 1) && 129 (ax25->condition & AX25_COND_OWN_RX_BUSY)) { 130 ax25->condition &= ~AX25_COND_OWN_RX_BUSY; 131 ax25->condition &= ~AX25_COND_ACK_PENDING; 132 break; 133 } 134 } 135 break; 136 } 137 138 if (sk) 139 bh_unlock_sock(sk); 140 141 ax25_start_heartbeat(ax25); 142 } 143 144 /* dl1bke 960114: T3 works much like the IDLE timeout, but 145 * gets reloaded with every frame for this 146 * connection. 147 */ 148 void ax25_ds_t3timer_expiry(ax25_cb *ax25) 149 { 150 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); 151 ax25_dama_off(ax25); 152 ax25_disconnect(ax25, ETIMEDOUT); 153 } 154 155 /* dl1bke 960228: close the connection when IDLE expires. 156 * unlike T3 this timer gets reloaded only on 157 * I frames. 158 */ 159 void ax25_ds_idletimer_expiry(ax25_cb *ax25) 160 { 161 ax25_clear_queues(ax25); 162 163 ax25->n2count = 0; 164 ax25->state = AX25_STATE_2; 165 166 ax25_calculate_t1(ax25); 167 ax25_start_t1timer(ax25); 168 ax25_stop_t3timer(ax25); 169 170 if (ax25->sk != NULL) { 171 bh_lock_sock(ax25->sk); 172 ax25->sk->sk_state = TCP_CLOSE; 173 ax25->sk->sk_err = 0; 174 ax25->sk->sk_shutdown |= SEND_SHUTDOWN; 175 if (!sock_flag(ax25->sk, SOCK_DEAD)) { 176 ax25->sk->sk_state_change(ax25->sk); 177 sock_set_flag(ax25->sk, SOCK_DEAD); 178 } 179 bh_unlock_sock(ax25->sk); 180 } 181 } 182 183 /* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC 184 * within the poll of any connected channel. Remember 185 * that we are not allowed to send anything unless we 186 * get polled by the Master. 187 * 188 * Thus we'll have to do parts of our T1 handling in 189 * ax25_enquiry_response(). 190 */ 191 void ax25_ds_t1_timeout(ax25_cb *ax25) 192 { 193 switch (ax25->state) { 194 case AX25_STATE_1: 195 if (ax25->n2count == ax25->n2) { 196 if (ax25->modulus == AX25_MODULUS) { 197 ax25_disconnect(ax25, ETIMEDOUT); 198 return; 199 } else { 200 ax25->modulus = AX25_MODULUS; 201 ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW]; 202 ax25->n2count = 0; 203 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND); 204 } 205 } else { 206 ax25->n2count++; 207 if (ax25->modulus == AX25_MODULUS) 208 ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND); 209 else 210 ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND); 211 } 212 break; 213 214 case AX25_STATE_2: 215 if (ax25->n2count == ax25->n2) { 216 ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); 217 if (!sock_flag(ax25->sk, SOCK_DESTROY)) 218 ax25_disconnect(ax25, ETIMEDOUT); 219 return; 220 } else { 221 ax25->n2count++; 222 } 223 break; 224 225 case AX25_STATE_3: 226 if (ax25->n2count == ax25->n2) { 227 ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE); 228 ax25_disconnect(ax25, ETIMEDOUT); 229 return; 230 } else { 231 ax25->n2count++; 232 } 233 break; 234 } 235 236 ax25_calculate_t1(ax25); 237 ax25_start_t1timer(ax25); 238 } 239