--- /dev/null
+/*
+ * 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/in.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/spinlock.h>
+#include <linux/net.h>
+#include <linux/gfp.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>
+
+void ax25_ds_nr_error_recovery(ax25_cb *ax25)
+{
+ ax25_ds_establish_data_link(ax25);
+}
+
+/*
+ * dl1bke 960114: transmit I frames on DAMA poll
+ */
+void ax25_ds_enquiry_response(ax25_cb *ax25)
+{
+ ax25_cb *ax25o;
+
+ /* Please note that neither DK4EG's nor DG2FEF's
+ * DAMA spec mention the following behaviour as seen
+ * with TheFirmware:
+ *
+ * DB0ACH->DL1BKE <RR C P R0> [DAMA]
+ * DL1BKE->DB0ACH <I NR=0 NS=0>
+ * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
+ * DL1BKE->DB0ACH <RR R F R0>
+ *
+ * The Flexnet DAMA Master implementation apparently
+ * insists on the "proper" AX.25 behaviour:
+ *
+ * DB0ACH->DL1BKE <RR C P R0> [DAMA]
+ * DL1BKE->DB0ACH <RR R F R0>
+ * DL1BKE->DB0ACH <I NR=0 NS=0>
+ * DL1BKE-7->DB0PRA-6 DB0ACH <I C S3 R5>
+ *
+ * Flexnet refuses to send us *any* I frame if we send
+ * a REJ in case AX25_COND_REJECT is set. It is superfluous in
+ * this mode anyway (a RR or RNR invokes the retransmission).
+ * Is this a Flexnet bug?
+ */
+
+ ax25_std_enquiry_response(ax25);
+
+ if (!(ax25->condition & AX25_COND_PEER_RX_BUSY)) {
+ ax25_requeue_frames(ax25);
+ ax25_kick(ax25);
+ }
+
+ if (ax25->state == AX25_STATE_1 || ax25->state == AX25_STATE_2 || skb_peek(&ax25->ack_queue) != NULL)
+ ax25_ds_t1_timeout(ax25);
+ else
+ ax25->n2count = 0;
+
+ ax25_start_t3timer(ax25);
+ ax25_ds_set_timer(ax25->ax25_dev);
+
+ spin_lock(&ax25_list_lock);
+ ax25_for_each(ax25o, &ax25_list) {
+ if (ax25o == ax25)
+ continue;
+
+ if (ax25o->ax25_dev != ax25->ax25_dev)
+ continue;
+
+ if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2) {
+ ax25_ds_t1_timeout(ax25o);
+ continue;
+ }
+
+ if (!(ax25o->condition & AX25_COND_PEER_RX_BUSY) && ax25o->state == AX25_STATE_3) {
+ ax25_requeue_frames(ax25o);
+ ax25_kick(ax25o);
+ }
+
+ if (ax25o->state == AX25_STATE_1 || ax25o->state == AX25_STATE_2 || skb_peek(&ax25o->ack_queue) != NULL)
+ ax25_ds_t1_timeout(ax25o);
+
+ /* do not start T3 for listening sockets (tnx DD8NE) */
+
+ if (ax25o->state != AX25_STATE_0)
+ ax25_start_t3timer(ax25o);
+ }
+ spin_unlock(&ax25_list_lock);
+}
+
+void ax25_ds_establish_data_link(ax25_cb *ax25)
+{
+ ax25->condition &= AX25_COND_DAMA_MODE;
+ ax25->n2count = 0;
+ ax25_calculate_t1(ax25);
+ ax25_start_t1timer(ax25);
+ ax25_stop_t2timer(ax25);
+ ax25_start_t3timer(ax25);
+}
+
+/*
+ * :::FIXME:::
+ * This is a kludge. Not all drivers recognize kiss commands.
+ * We need a driver level request to switch duplex mode, that does
+ * either SCC changing, PI config or KISS as required. Currently
+ * this request isn't reliable.
+ */
+static void ax25_kiss_cmd(ax25_dev *ax25_dev, unsigned char cmd, unsigned char param)
+{
+ struct sk_buff *skb;
+ unsigned char *p;
+
+ if (ax25_dev->dev == NULL)
+ return;
+
+ if ((skb = alloc_skb(2, GFP_ATOMIC)) == NULL)
+ return;
+
+ skb_reset_network_header(skb);
+ p = skb_put(skb, 2);
+
+ *p++ = cmd;
+ *p++ = param;
+
+ skb->protocol = ax25_type_trans(skb, ax25_dev->dev);
+
+ dev_queue_xmit(skb);
+}
+
+/*
+ * A nasty problem arises if we count the number of DAMA connections
+ * wrong, especially when connections on the device already existed
+ * and our network node (or the sysop) decides to turn on DAMA Master
+ * mode. We thus flag the 'real' slave connections with
+ * ax25->dama_slave=1 and look on every disconnect if still slave
+ * connections exist.
+ */
+static int ax25_check_dama_slave(ax25_dev *ax25_dev)
+{
+ ax25_cb *ax25;
+ int res = 0;
+
+ spin_lock(&ax25_list_lock);
+ ax25_for_each(ax25, &ax25_list)
+ if (ax25->ax25_dev == ax25_dev && (ax25->condition & AX25_COND_DAMA_MODE) && ax25->state > AX25_STATE_1) {
+ res = 1;
+ break;
+ }
+ spin_unlock(&ax25_list_lock);
+
+ return res;
+}
+
+static void ax25_dev_dama_on(ax25_dev *ax25_dev)
+{
+ if (ax25_dev == NULL)
+ return;
+
+ if (ax25_dev->dama.slave == 0)
+ ax25_kiss_cmd(ax25_dev, 5, 1);
+
+ ax25_dev->dama.slave = 1;
+ ax25_ds_set_timer(ax25_dev);
+}
+
+void ax25_dev_dama_off(ax25_dev *ax25_dev)
+{
+ if (ax25_dev == NULL)
+ return;
+
+ if (ax25_dev->dama.slave && !ax25_check_dama_slave(ax25_dev)) {
+ ax25_kiss_cmd(ax25_dev, 5, 0);
+ ax25_dev->dama.slave = 0;
+ ax25_ds_del_timer(ax25_dev);
+ }
+}
+
+void ax25_dama_on(ax25_cb *ax25)
+{
+ ax25_dev_dama_on(ax25->ax25_dev);
+ ax25->condition |= AX25_COND_DAMA_MODE;
+}
+
+void ax25_dama_off(ax25_cb *ax25)
+{
+ ax25->condition &= ~AX25_COND_DAMA_MODE;
+ ax25_dev_dama_off(ax25->ax25_dev);
+}
+
Code Review / kvmfornfv.git / blobdiff