1 files changed, 436 insertions, 0 deletions

diff --git a/net/lapb/lapb_iface.c b/net/lapb/lapb_iface.c
new file mode 100644
index 000000000..3c03f6512
--- /dev/null
+++ b/net/lapb/lapb_iface.c
@@ -0,0 +1,436 @@
+// 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.
+ *	2000-10-29	Henner Eisen	lapb_data_indication() return status.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#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/if_arp.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <linux/uaccess.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/stat.h>
+#include <linux/init.h>
+#include <net/lapb.h>
+
+static LIST_HEAD(lapb_list);
+static DEFINE_RWLOCK(lapb_list_lock);
+
+/*
+ *	Free an allocated lapb control block.
+ */
+static void lapb_free_cb(struct lapb_cb *lapb)
+{
+	kfree(lapb);
+}
+
+static __inline__ void lapb_hold(struct lapb_cb *lapb)
+{
+	refcount_inc(&lapb->refcnt);
+}
+
+static __inline__ void lapb_put(struct lapb_cb *lapb)
+{
+	if (refcount_dec_and_test(&lapb->refcnt))
+		lapb_free_cb(lapb);
+}
+
+/*
+ *	Socket removal during an interrupt is now safe.
+ */
+static void __lapb_remove_cb(struct lapb_cb *lapb)
+{
+	if (lapb->node.next) {
+		list_del(&lapb->node);
+		lapb_put(lapb);
+	}
+}
+
+/*
+ *	Add a socket to the bound sockets list.
+ */
+static void __lapb_insert_cb(struct lapb_cb *lapb)
+{
+	list_add(&lapb->node, &lapb_list);
+	lapb_hold(lapb);
+}
+
+static struct lapb_cb *__lapb_devtostruct(struct net_device *dev)
+{
+	struct list_head *entry;
+	struct lapb_cb *lapb, *use = NULL;
+
+	list_for_each(entry, &lapb_list) {
+		lapb = list_entry(entry, struct lapb_cb, node);
+		if (lapb->dev == dev) {
+			use = lapb;
+			break;
+		}
+	}
+
+	if (use)
+		lapb_hold(use);
+
+	return use;
+}
+
+static struct lapb_cb *lapb_devtostruct(struct net_device *dev)
+{
+	struct lapb_cb *rc;
+
+	read_lock_bh(&lapb_list_lock);
+	rc = __lapb_devtostruct(dev);
+	read_unlock_bh(&lapb_list_lock);
+
+	return rc;
+}
+/*
+ *	Create an empty LAPB control block.
+ */
+static struct lapb_cb *lapb_create_cb(void)
+{
+	struct lapb_cb *lapb = kzalloc(sizeof(*lapb), GFP_ATOMIC);
+
+	if (!lapb)
+		goto out;
+
+	skb_queue_head_init(&lapb->write_queue);
+	skb_queue_head_init(&lapb->ack_queue);
+
+	timer_setup(&lapb->t1timer, NULL, 0);
+	timer_setup(&lapb->t2timer, NULL, 0);
+
+	lapb->t1      = LAPB_DEFAULT_T1;
+	lapb->t2      = LAPB_DEFAULT_T2;
+	lapb->n2      = LAPB_DEFAULT_N2;
+	lapb->mode    = LAPB_DEFAULT_MODE;
+	lapb->window  = LAPB_DEFAULT_WINDOW;
+	lapb->state   = LAPB_STATE_0;
+	refcount_set(&lapb->refcnt, 1);
+out:
+	return lapb;
+}
+
+int lapb_register(struct net_device *dev,
+		  const struct lapb_register_struct *callbacks)
+{
+	struct lapb_cb *lapb;
+	int rc = LAPB_BADTOKEN;
+
+	write_lock_bh(&lapb_list_lock);
+
+	lapb = __lapb_devtostruct(dev);
+	if (lapb) {
+		lapb_put(lapb);
+		goto out;
+	}
+
+	lapb = lapb_create_cb();
+	rc = LAPB_NOMEM;
+	if (!lapb)
+		goto out;
+
+	lapb->dev       = dev;
+	lapb->callbacks = callbacks;
+
+	__lapb_insert_cb(lapb);
+
+	lapb_start_t1timer(lapb);
+
+	rc = LAPB_OK;
+out:
+	write_unlock_bh(&lapb_list_lock);
+	return rc;
+}
+EXPORT_SYMBOL(lapb_register);
+
+int lapb_unregister(struct net_device *dev)
+{
+	struct lapb_cb *lapb;
+	int rc = LAPB_BADTOKEN;
+
+	write_lock_bh(&lapb_list_lock);
+	lapb = __lapb_devtostruct(dev);
+	if (!lapb)
+		goto out;
+	lapb_put(lapb);
+
+	lapb_stop_t1timer(lapb);
+	lapb_stop_t2timer(lapb);
+
+	lapb_clear_queues(lapb);
+
+	__lapb_remove_cb(lapb);
+
+	lapb_put(lapb);
+	rc = LAPB_OK;
+out:
+	write_unlock_bh(&lapb_list_lock);
+	return rc;
+}
+EXPORT_SYMBOL(lapb_unregister);
+
+int lapb_getparms(struct net_device *dev, struct lapb_parms_struct *parms)
+{
+	int rc = LAPB_BADTOKEN;
+	struct lapb_cb *lapb = lapb_devtostruct(dev);
+
+	if (!lapb)
+		goto out;
+
+	parms->t1      = lapb->t1 / HZ;
+	parms->t2      = lapb->t2 / HZ;
+	parms->n2      = lapb->n2;
+	parms->n2count = lapb->n2count;
+	parms->state   = lapb->state;
+	parms->window  = lapb->window;
+	parms->mode    = lapb->mode;
+
+	if (!timer_pending(&lapb->t1timer))
+		parms->t1timer = 0;
+	else
+		parms->t1timer = (lapb->t1timer.expires - jiffies) / HZ;
+
+	if (!timer_pending(&lapb->t2timer))
+		parms->t2timer = 0;
+	else
+		parms->t2timer = (lapb->t2timer.expires - jiffies) / HZ;
+
+	lapb_put(lapb);
+	rc = LAPB_OK;
+out:
+	return rc;
+}
+EXPORT_SYMBOL(lapb_getparms);
+
+int lapb_setparms(struct net_device *dev, struct lapb_parms_struct *parms)
+{
+	int rc = LAPB_BADTOKEN;
+	struct lapb_cb *lapb = lapb_devtostruct(dev);
+
+	if (!lapb)
+		goto out;
+
+	rc = LAPB_INVALUE;
+	if (parms->t1 < 1 || parms->t2 < 1 || parms->n2 < 1)
+		goto out_put;
+
+	if (lapb->state == LAPB_STATE_0) {
+		if (parms->mode & LAPB_EXTENDED) {
+			if (parms->window < 1 || parms->window > 127)
+				goto out_put;
+		} else {
+			if (parms->window < 1 || parms->window > 7)
+				goto out_put;
+		}
+		lapb->mode    = parms->mode;
+		lapb->window  = parms->window;
+	}
+
+	lapb->t1    = parms->t1 * HZ;
+	lapb->t2    = parms->t2 * HZ;
+	lapb->n2    = parms->n2;
+
+	rc = LAPB_OK;
+out_put:
+	lapb_put(lapb);
+out:
+	return rc;
+}
+EXPORT_SYMBOL(lapb_setparms);
+
+int lapb_connect_request(struct net_device *dev)
+{
+	struct lapb_cb *lapb = lapb_devtostruct(dev);
+	int rc = LAPB_BADTOKEN;
+
+	if (!lapb)
+		goto out;
+
+	rc = LAPB_OK;
+	if (lapb->state == LAPB_STATE_1)
+		goto out_put;
+
+	rc = LAPB_CONNECTED;
+	if (lapb->state == LAPB_STATE_3 || lapb->state == LAPB_STATE_4)
+		goto out_put;
+
+	lapb_establish_data_link(lapb);
+
+	lapb_dbg(0, "(%p) S0 -> S1\n", lapb->dev);
+	lapb->state = LAPB_STATE_1;
+
+	rc = LAPB_OK;
+out_put:
+	lapb_put(lapb);
+out:
+	return rc;
+}
+EXPORT_SYMBOL(lapb_connect_request);
+
+int lapb_disconnect_request(struct net_device *dev)
+{
+	struct lapb_cb *lapb = lapb_devtostruct(dev);
+	int rc = LAPB_BADTOKEN;
+
+	if (!lapb)
+		goto out;
+
+	switch (lapb->state) {
+	case LAPB_STATE_0:
+		rc = LAPB_NOTCONNECTED;
+		goto out_put;
+
+	case LAPB_STATE_1:
+		lapb_dbg(1, "(%p) S1 TX DISC(1)\n", lapb->dev);
+		lapb_dbg(0, "(%p) S1 -> S0\n", lapb->dev);
+		lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
+		lapb->state = LAPB_STATE_0;
+		lapb_start_t1timer(lapb);
+		rc = LAPB_NOTCONNECTED;
+		goto out_put;
+
+	case LAPB_STATE_2:
+		rc = LAPB_OK;
+		goto out_put;
+	}
+
+	lapb_clear_queues(lapb);
+	lapb->n2count = 0;
+	lapb_send_control(lapb, LAPB_DISC, LAPB_POLLON, LAPB_COMMAND);
+	lapb_start_t1timer(lapb);
+	lapb_stop_t2timer(lapb);
+	lapb->state = LAPB_STATE_2;
+
+	lapb_dbg(1, "(%p) S3 DISC(1)\n", lapb->dev);
+	lapb_dbg(0, "(%p) S3 -> S2\n", lapb->dev);
+
+	rc = LAPB_OK;
+out_put:
+	lapb_put(lapb);
+out:
+	return rc;
+}
+EXPORT_SYMBOL(lapb_disconnect_request);
+
+int lapb_data_request(struct net_device *dev, struct sk_buff *skb)
+{
+	struct lapb_cb *lapb = lapb_devtostruct(dev);
+	int rc = LAPB_BADTOKEN;
+
+	if (!lapb)
+		goto out;
+
+	rc = LAPB_NOTCONNECTED;
+	if (lapb->state != LAPB_STATE_3 && lapb->state != LAPB_STATE_4)
+		goto out_put;
+
+	skb_queue_tail(&lapb->write_queue, skb);
+	lapb_kick(lapb);
+	rc = LAPB_OK;
+out_put:
+	lapb_put(lapb);
+out:
+	return rc;
+}
+EXPORT_SYMBOL(lapb_data_request);
+
+int lapb_data_received(struct net_device *dev, struct sk_buff *skb)
+{
+	struct lapb_cb *lapb = lapb_devtostruct(dev);
+	int rc = LAPB_BADTOKEN;
+
+	if (lapb) {
+		lapb_data_input(lapb, skb);
+		lapb_put(lapb);
+		rc = LAPB_OK;
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL(lapb_data_received);
+
+void lapb_connect_confirmation(struct lapb_cb *lapb, int reason)
+{
+	if (lapb->callbacks->connect_confirmation)
+		lapb->callbacks->connect_confirmation(lapb->dev, reason);
+}
+
+void lapb_connect_indication(struct lapb_cb *lapb, int reason)
+{
+	if (lapb->callbacks->connect_indication)
+		lapb->callbacks->connect_indication(lapb->dev, reason);
+}
+
+void lapb_disconnect_confirmation(struct lapb_cb *lapb, int reason)
+{
+	if (lapb->callbacks->disconnect_confirmation)
+		lapb->callbacks->disconnect_confirmation(lapb->dev, reason);
+}
+
+void lapb_disconnect_indication(struct lapb_cb *lapb, int reason)
+{
+	if (lapb->callbacks->disconnect_indication)
+		lapb->callbacks->disconnect_indication(lapb->dev, reason);
+}
+
+int lapb_data_indication(struct lapb_cb *lapb, struct sk_buff *skb)
+{
+	if (lapb->callbacks->data_indication)
+		return lapb->callbacks->data_indication(lapb->dev, skb);
+
+	kfree_skb(skb);
+	return NET_RX_SUCCESS; /* For now; must be != NET_RX_DROP */
+}
+
+int lapb_data_transmit(struct lapb_cb *lapb, struct sk_buff *skb)
+{
+	int used = 0;
+
+	if (lapb->callbacks->data_transmit) {
+		lapb->callbacks->data_transmit(lapb->dev, skb);
+		used = 1;
+	}
+
+	return used;
+}
+
+static int __init lapb_init(void)
+{
+	return 0;
+}
+
+static void __exit lapb_exit(void)
+{
+	WARN_ON(!list_empty(&lapb_list));
+}
+
+MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
+MODULE_DESCRIPTION("The X.25 Link Access Procedure B link layer protocol");
+MODULE_LICENSE("GPL");
+
+module_init(lapb_init);
+module_exit(lapb_exit);