diff options
Diffstat (limited to '')
| -rw-r--r-- | net/ax25/ax25_ds_timer.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/net/ax25/ax25_ds_timer.c b/net/ax25/ax25_ds_timer.c new file mode 100644 index 000000000..c4f8adbf8 --- /dev/null +++ b/net/ax25/ax25_ds_timer.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * + * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) + * Copyright (C) Joerg Reuter DL1BKE (jreuter@yaina.de) + */ +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/spinlock.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/jiffies.h> +#include <linux/timer.h> +#include <linux/string.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <net/tcp_states.h> +#include <net/ax25.h> +#include <linux/inet.h> +#include <linux/netdevice.h> +#include <linux/skbuff.h> +#include <net/sock.h> +#include <linux/uaccess.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/interrupt.h> + +static void ax25_ds_timeout(struct timer_list *); + +/* + * Add DAMA slave timeout timer to timer list. + * Unlike the connection based timers the timeout function gets + * triggered every second. Please note that NET_AX25_DAMA_SLAVE_TIMEOUT + * (aka /proc/sys/net/ax25/{dev}/dama_slave_timeout) is still in + * 1/10th of a second. + */ + +void ax25_ds_setup_timer(ax25_dev *ax25_dev) +{ + timer_setup(&ax25_dev->dama.slave_timer, ax25_ds_timeout, 0); +} + +void ax25_ds_del_timer(ax25_dev *ax25_dev) +{ + if (ax25_dev) + del_timer(&ax25_dev->dama.slave_timer); +} + +void ax25_ds_set_timer(ax25_dev *ax25_dev) +{ + if (ax25_dev == NULL) /* paranoia */ + return; + + ax25_dev->dama.slave_timeout = + msecs_to_jiffies(ax25_dev->values[AX25_VALUES_DS_TIMEOUT]) / 10; + mod_timer(&ax25_dev->dama.slave_timer, jiffies + HZ); +} + +/* + * DAMA Slave Timeout + * Silently discard all (slave) connections in case our master forgot us... + */ + +static void ax25_ds_timeout(struct timer_list *t) +{ + ax25_dev *ax25_dev = from_timer(ax25_dev, t, dama.slave_timer); + ax25_cb *ax25; + + if (ax25_dev == NULL || !ax25_dev->dama.slave) + return; /* Yikes! */ + + if (!ax25_dev->dama.slave_timeout || --ax25_dev->dama.slave_timeout) { + ax25_ds_set_timer(ax25_dev); + return; + } + + spin_lock(&ax25_list_lock); + ax25_for_each(ax25, &ax25_list) { + if (ax25->ax25_dev != ax25_dev || !(ax25->condition & AX25_COND_DAMA_MODE)) + continue; + + ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); + ax25_disconnect(ax25, ETIMEDOUT); + } + spin_unlock(&ax25_list_lock); + + ax25_dev_dama_off(ax25_dev); +} + +void ax25_ds_heartbeat_expiry(ax25_cb *ax25) +{ + struct sock *sk=ax25->sk; + + if (sk) + bh_lock_sock(sk); + + switch (ax25->state) { + + case AX25_STATE_0: + case AX25_STATE_2: + /* Magic here: If we listen() and a new link dies before it + is accepted() it isn't 'dead' so doesn't get removed. */ + if (!sk || sock_flag(sk, SOCK_DESTROY) || + (sk->sk_state == TCP_LISTEN && + sock_flag(sk, SOCK_DEAD))) { + if (sk) { + sock_hold(sk); + ax25_destroy_socket(ax25); + bh_unlock_sock(sk); + /* Ungrab socket and destroy it */ + sock_put(sk); + } else + ax25_destroy_socket(ax25); + return; + } + break; + + case AX25_STATE_3: + /* + * Check the state of the receive buffer. + */ + if (sk != NULL) { + if (atomic_read(&sk->sk_rmem_alloc) < + (sk->sk_rcvbuf >> 1) && + (ax25->condition & AX25_COND_OWN_RX_BUSY)) { + ax25->condition &= ~AX25_COND_OWN_RX_BUSY; + ax25->condition &= ~AX25_COND_ACK_PENDING; + break; + } + } + break; + } + + if (sk) + bh_unlock_sock(sk); + + ax25_start_heartbeat(ax25); +} + +/* dl1bke 960114: T3 works much like the IDLE timeout, but + * gets reloaded with every frame for this + * connection. + */ +void ax25_ds_t3timer_expiry(ax25_cb *ax25) +{ + ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); + ax25_dama_off(ax25); + ax25_disconnect(ax25, ETIMEDOUT); +} + +/* dl1bke 960228: close the connection when IDLE expires. + * unlike T3 this timer gets reloaded only on + * I frames. + */ +void ax25_ds_idletimer_expiry(ax25_cb *ax25) +{ + ax25_clear_queues(ax25); + + ax25->n2count = 0; + ax25->state = AX25_STATE_2; + + ax25_calculate_t1(ax25); + ax25_start_t1timer(ax25); + ax25_stop_t3timer(ax25); + + if (ax25->sk != NULL) { + bh_lock_sock(ax25->sk); + ax25->sk->sk_state = TCP_CLOSE; + ax25->sk->sk_err = 0; + ax25->sk->sk_shutdown |= SEND_SHUTDOWN; + if (!sock_flag(ax25->sk, SOCK_DEAD)) { + ax25->sk->sk_state_change(ax25->sk); + sock_set_flag(ax25->sk, SOCK_DEAD); + } + bh_unlock_sock(ax25->sk); + } +} + +/* dl1bke 960114: The DAMA protocol requires to send data and SABM/DISC + * within the poll of any connected channel. Remember + * that we are not allowed to send anything unless we + * get polled by the Master. + * + * Thus we'll have to do parts of our T1 handling in + * ax25_enquiry_response(). + */ +void ax25_ds_t1_timeout(ax25_cb *ax25) +{ + switch (ax25->state) { + case AX25_STATE_1: + if (ax25->n2count == ax25->n2) { + if (ax25->modulus == AX25_MODULUS) { + ax25_disconnect(ax25, ETIMEDOUT); + return; + } else { + ax25->modulus = AX25_MODULUS; + ax25->window = ax25->ax25_dev->values[AX25_VALUES_WINDOW]; + ax25->n2count = 0; + ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND); + } + } else { + ax25->n2count++; + if (ax25->modulus == AX25_MODULUS) + ax25_send_control(ax25, AX25_SABM, AX25_POLLOFF, AX25_COMMAND); + else + ax25_send_control(ax25, AX25_SABME, AX25_POLLOFF, AX25_COMMAND); + } + break; + + case AX25_STATE_2: + if (ax25->n2count == ax25->n2) { + ax25_send_control(ax25, AX25_DISC, AX25_POLLON, AX25_COMMAND); + if (!sock_flag(ax25->sk, SOCK_DESTROY)) + ax25_disconnect(ax25, ETIMEDOUT); + return; + } else { + ax25->n2count++; + } + break; + + case AX25_STATE_3: + if (ax25->n2count == ax25->n2) { + ax25_send_control(ax25, AX25_DM, AX25_POLLON, AX25_RESPONSE); + ax25_disconnect(ax25, ETIMEDOUT); + return; + } else { + ax25->n2count++; + } + break; + } + + ax25_calculate_t1(ax25); + ax25_start_t1timer(ax25); +} |