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-rw-r--r--net/lapb/lapb_timer.c206
1 files changed, 206 insertions, 0 deletions
diff --git a/net/lapb/lapb_timer.c b/net/lapb/lapb_timer.c
new file mode 100644
index 000000000..5be688690
--- /dev/null
+++ b/net/lapb/lapb_timer.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * LAPB release 002
+ *
+ * This code REQUIRES 2.1.15 or higher/ NET3.038
+ *
+ * History
+ * LAPB 001 Jonathan Naylor Started Coding
+ * LAPB 002 Jonathan Naylor New timer architecture.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.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 <linux/inet.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>
+#include <net/lapb.h>
+
+static void lapb_t1timer_expiry(struct timer_list *);
+static void lapb_t2timer_expiry(struct timer_list *);
+
+void lapb_start_t1timer(struct lapb_cb *lapb)
+{
+ del_timer(&lapb->t1timer);
+
+ lapb->t1timer.function = lapb_t1timer_expiry;
+ lapb->t1timer.expires = jiffies + lapb->t1;
+
+ lapb->t1timer_running = true;
+ add_timer(&lapb->t1timer);
+}
+
+void lapb_start_t2timer(struct lapb_cb *lapb)
+{
+ del_timer(&lapb->t2timer);
+
+ lapb->t2timer.function = lapb_t2timer_expiry;
+ lapb->t2timer.expires = jiffies + lapb->t2;
+
+ lapb->t2timer_running = true;
+ add_timer(&lapb->t2timer);
+}
+
+void lapb_stop_t1timer(struct lapb_cb *lapb)
+{
+ lapb->t1timer_running = false;
+ del_timer(&lapb->t1timer);
+}
+
+void lapb_stop_t2timer(struct lapb_cb *lapb)
+{
+ lapb->t2timer_running = false;
+ del_timer(&lapb->t2timer);
+}
+
+int lapb_t1timer_running(struct lapb_cb *lapb)
+{
+ return lapb->t1timer_running;
+}
+
+static void lapb_t2timer_expiry(struct timer_list *t)
+{
+ struct lapb_cb *lapb = from_timer(lapb, t, t2timer);
+
+ spin_lock_bh(&lapb->lock);
+ if (timer_pending(&lapb->t2timer)) /* A new timer has been set up */
+ goto out;
+ if (!lapb->t2timer_running) /* The timer has been stopped */
+ goto out;
+
+ if (lapb->condition & LAPB_ACK_PENDING_CONDITION) {
+ lapb->condition &= ~LAPB_ACK_PENDING_CONDITION;
+ lapb_timeout_response(lapb);
+ }
+ lapb->t2timer_running = false;
+
+out:
+ spin_unlock_bh(&lapb->lock);
+}
+
+static void lapb_t1timer_expiry(struct timer_list *t)
+{
+ struct lapb_cb *lapb = from_timer(lapb, t, t1timer);
+
+ spin_lock_bh(&lapb->lock);
+ if (timer_pending(&lapb->t1timer)) /* A new timer has been set up */
+ goto out;
+ if (!lapb->t1timer_running) /* The timer has been stopped */
+ goto out;
+
+ switch (lapb->state) {
+
+ /*
+ * If we are a DCE, send DM up to N2 times, then switch to
+ * STATE_1 and send SABM(E).
+ */
+ case LAPB_STATE_0:
+ if (lapb->mode & LAPB_DCE &&
+ lapb->n2count != lapb->n2) {
+ lapb->n2count++;
+ lapb_send_control(lapb, LAPB_DM, LAPB_POLLOFF, LAPB_RESPONSE);
+ } else {
+ lapb->state = LAPB_STATE_1;
+ lapb_establish_data_link(lapb);
+ }
+ break;
+
+ /*
+ * Awaiting connection state, send SABM(E), up to N2 times.
+ */
+ case LAPB_STATE_1:
+ if (lapb->n2count == lapb->n2) {
+ lapb_clear_queues(lapb);
+ lapb->state = LAPB_STATE_0;
+ lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
+ lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
+ lapb->t1timer_running = false;
+ goto out;
+ } else {
+ lapb->n2count++;
+ if (lapb->mode & LAPB_EXTENDED) {
+ lapb_dbg(1, "(%p) S1 TX SABME(1)\n",
+ lapb->dev);
+ lapb_send_control(lapb, LAPB_SABME, LAPB_POLLON, LAPB_COMMAND);
+ } else {
+ lapb_dbg(1, "(%p) S1 TX SABM(1)\n",
+ lapb->dev);
+ lapb_send_control(lapb, LAPB_SABM, LAPB_POLLON, LAPB_COMMAND);
+ }
+ }
+ break;
+
+ /*
+ * Awaiting disconnection state, send DISC, up to N2 times.
+ */
+ case LAPB_STATE_2:
+ if (lapb->n2count == lapb->n2) {
+ lapb_clear_queues(lapb);
+ lapb->state = LAPB_STATE_0;
+ lapb_disconnect_confirmation(lapb, LAPB_TIMEDOUT);
+ lapb_dbg(0, "(%p) S2 -> S0\n", lapb->dev);
+ lapb->t1timer_running = false;
+ goto out;
+ } else {
+ lapb->n2count++;
+ lapb_dbg(1, "(%p) S2 TX DISC(1)\n", lapb->dev);
+ lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
+ }
+ break;
+
+ /*
+ * Data transfer state, restransmit I frames, up to N2 times.
+ */
+ case LAPB_STATE_3:
+ if (lapb->n2count == lapb->n2) {
+ lapb_clear_queues(lapb);
+ lapb->state = LAPB_STATE_0;
+ lapb_stop_t2timer(lapb);
+ lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
+ lapb_dbg(0, "(%p) S3 -> S0\n", lapb->dev);
+ lapb->t1timer_running = false;
+ goto out;
+ } else {
+ lapb->n2count++;
+ lapb_requeue_frames(lapb);
+ lapb_kick(lapb);
+ }
+ break;
+
+ /*
+ * Frame reject state, restransmit FRMR frames, up to N2 times.
+ */
+ case LAPB_STATE_4:
+ if (lapb->n2count == lapb->n2) {
+ lapb_clear_queues(lapb);
+ lapb->state = LAPB_STATE_0;
+ lapb_disconnect_indication(lapb, LAPB_TIMEDOUT);
+ lapb_dbg(0, "(%p) S4 -> S0\n", lapb->dev);
+ lapb->t1timer_running = false;
+ goto out;
+ } else {
+ lapb->n2count++;
+ lapb_transmit_frmr(lapb);
+ }
+ break;
+ }
+
+ lapb_start_t1timer(lapb);
+
+out:
+ spin_unlock_bh(&lapb->lock);
+}