--- /dev/null
+/*
+ * LAPB release 002
+ *
+ * This code REQUIRES 2.1.15 or higher/ NET3.038
+ *
+ * This module:
+ * This module 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.
+ *
+ * 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 <asm/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)
+{
+ atomic_inc(&lapb->refcnt);
+}
+
+static __inline__ void lapb_put(struct lapb_cb *lapb)
+{
+ if (atomic_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);
+ }
+}
+EXPORT_SYMBOL(lapb_register);
+
+/*
+ * 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);
+
+ init_timer(&lapb->t1timer);
+ init_timer(&lapb->t2timer);
+
+ 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;
+ atomic_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;
+}
+
+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_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);
Code Review / kvmfornfv.git / blobdiff