File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/ax25/ax25_ds_timer.c b/net/ax25/ax25_ds_timer.c
new file mode 100644
index 0000000..5237dff
--- /dev/null
+++ b/net/ax25/ax25_ds_timer.c
@@ -0,0 +1,239 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 <asm/uaccess.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+
+static void ax25_ds_timeout(unsigned long);
+
+/*
+ * 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)
+{
+ setup_timer(&ax25_dev->dama.slave_timer, ax25_ds_timeout,
+ (unsigned long)ax25_dev);
+}
+
+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(unsigned long arg)
+{
+ ax25_dev *ax25_dev = (struct ax25_dev *) arg;
+ 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);
+}