Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 238 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..e9d11313d
--- /dev/null
+++ b/net/ax25/ax25_ds_timer.c
@@ -0,0 +1,238 @@
+/*
+ * 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 <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);
+}