Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 526 insertions, 0 deletions

diff --git a/drivers/net/wan/lapbether.c b/drivers/net/wan/lapbether.c
new file mode 100644
index 000000000..56326f38f
--- /dev/null
+++ b/drivers/net/wan/lapbether.c
@@ -0,0 +1,526 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	"LAPB via ethernet" driver release 001
+ *
+ *	This code REQUIRES 2.1.15 or higher/ NET3.038
+ *
+ *	This is a "pseudo" network driver to allow LAPB over Ethernet.
+ *
+ *	This driver can use any ethernet destination address, and can be
+ *	limited to accept frames from one dedicated ethernet card only.
+ *
+ *	History
+ *	LAPBETH 001	Jonathan Naylor		Cloned from bpqether.c
+ *	2000-10-29	Henner Eisen	lapb_data_indication() return status.
+ *	2000-11-14	Henner Eisen	dev_hold/put, NETDEV_GOING_DOWN support
+ */
+
+#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/slab.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/net.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <linux/uaccess.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+#include <linux/notifier.h>
+#include <linux/stat.h>
+#include <linux/module.h>
+#include <linux/lapb.h>
+#include <linux/init.h>
+
+#include <net/x25device.h>
+
+static const u8 bcast_addr[6] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
+
+/* If this number is made larger, check that the temporary string buffer
+ * in lapbeth_new_device is large enough to store the probe device name.
+ */
+#define MAXLAPBDEV 100
+
+struct lapbethdev {
+	struct list_head	node;
+	struct net_device	*ethdev;	/* link to ethernet device */
+	struct net_device	*axdev;		/* lapbeth device (lapb#) */
+	bool			up;
+	spinlock_t		up_lock;	/* Protects "up" */
+	struct sk_buff_head	rx_queue;
+	struct napi_struct	napi;
+};
+
+static LIST_HEAD(lapbeth_devices);
+
+static void lapbeth_connected(struct net_device *dev, int reason);
+static void lapbeth_disconnected(struct net_device *dev, int reason);
+
+/* ------------------------------------------------------------------------ */
+
+/*	Get the LAPB device for the ethernet device
+ */
+static struct lapbethdev *lapbeth_get_x25_dev(struct net_device *dev)
+{
+	struct lapbethdev *lapbeth;
+
+	list_for_each_entry_rcu(lapbeth, &lapbeth_devices, node, lockdep_rtnl_is_held()) {
+		if (lapbeth->ethdev == dev)
+			return lapbeth;
+	}
+	return NULL;
+}
+
+static __inline__ int dev_is_ethdev(struct net_device *dev)
+{
+	return dev->type == ARPHRD_ETHER && strncmp(dev->name, "dummy", 5);
+}
+
+/* ------------------------------------------------------------------------ */
+
+static int lapbeth_napi_poll(struct napi_struct *napi, int budget)
+{
+	struct lapbethdev *lapbeth = container_of(napi, struct lapbethdev,
+						  napi);
+	struct sk_buff *skb;
+	int processed = 0;
+
+	for (; processed < budget; ++processed) {
+		skb = skb_dequeue(&lapbeth->rx_queue);
+		if (!skb)
+			break;
+		netif_receive_skb_core(skb);
+	}
+
+	if (processed < budget)
+		napi_complete(napi);
+
+	return processed;
+}
+
+/*	Receive a LAPB frame via an ethernet interface.
+ */
+static int lapbeth_rcv(struct sk_buff *skb, struct net_device *dev,
+		       struct packet_type *ptype, struct net_device *orig_dev)
+{
+	int len, err;
+	struct lapbethdev *lapbeth;
+
+	if (dev_net(dev) != &init_net)
+		goto drop;
+
+	skb = skb_share_check(skb, GFP_ATOMIC);
+	if (!skb)
+		return NET_RX_DROP;
+
+	if (!pskb_may_pull(skb, 2))
+		goto drop;
+
+	rcu_read_lock();
+	lapbeth = lapbeth_get_x25_dev(dev);
+	if (!lapbeth)
+		goto drop_unlock_rcu;
+	spin_lock_bh(&lapbeth->up_lock);
+	if (!lapbeth->up)
+		goto drop_unlock;
+
+	len = skb->data[0] + skb->data[1] * 256;
+	dev->stats.rx_packets++;
+	dev->stats.rx_bytes += len;
+
+	skb_pull(skb, 2);	/* Remove the length bytes */
+	skb_trim(skb, len);	/* Set the length of the data */
+
+	err = lapb_data_received(lapbeth->axdev, skb);
+	if (err != LAPB_OK) {
+		printk(KERN_DEBUG "lapbether: lapb_data_received err - %d\n", err);
+		goto drop_unlock;
+	}
+out:
+	spin_unlock_bh(&lapbeth->up_lock);
+	rcu_read_unlock();
+	return 0;
+drop_unlock:
+	kfree_skb(skb);
+	goto out;
+drop_unlock_rcu:
+	rcu_read_unlock();
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+static int lapbeth_data_indication(struct net_device *dev, struct sk_buff *skb)
+{
+	struct lapbethdev *lapbeth = netdev_priv(dev);
+	unsigned char *ptr;
+
+	if (skb_cow(skb, 1)) {
+		kfree_skb(skb);
+		return NET_RX_DROP;
+	}
+
+	skb_push(skb, 1);
+
+	ptr  = skb->data;
+	*ptr = X25_IFACE_DATA;
+
+	skb->protocol = x25_type_trans(skb, dev);
+
+	skb_queue_tail(&lapbeth->rx_queue, skb);
+	napi_schedule(&lapbeth->napi);
+	return NET_RX_SUCCESS;
+}
+
+/*	Send a LAPB frame via an ethernet interface
+ */
+static netdev_tx_t lapbeth_xmit(struct sk_buff *skb,
+				struct net_device *dev)
+{
+	struct lapbethdev *lapbeth = netdev_priv(dev);
+	int err;
+
+	spin_lock_bh(&lapbeth->up_lock);
+	if (!lapbeth->up)
+		goto drop;
+
+	/* There should be a pseudo header of 1 byte added by upper layers.
+	 * Check to make sure it is there before reading it.
+	 */
+	if (skb->len < 1)
+		goto drop;
+
+	switch (skb->data[0]) {
+	case X25_IFACE_DATA:
+		break;
+	case X25_IFACE_CONNECT:
+		err = lapb_connect_request(dev);
+		if (err == LAPB_CONNECTED)
+			lapbeth_connected(dev, LAPB_OK);
+		else if (err != LAPB_OK)
+			pr_err("lapb_connect_request error: %d\n", err);
+		goto drop;
+	case X25_IFACE_DISCONNECT:
+		err = lapb_disconnect_request(dev);
+		if (err == LAPB_NOTCONNECTED)
+			lapbeth_disconnected(dev, LAPB_OK);
+		else if (err != LAPB_OK)
+			pr_err("lapb_disconnect_request err: %d\n", err);
+		fallthrough;
+	default:
+		goto drop;
+	}
+
+	skb_pull(skb, 1);
+
+	err = lapb_data_request(dev, skb);
+	if (err != LAPB_OK) {
+		pr_err("lapb_data_request error - %d\n", err);
+		goto drop;
+	}
+out:
+	spin_unlock_bh(&lapbeth->up_lock);
+	return NETDEV_TX_OK;
+drop:
+	kfree_skb(skb);
+	goto out;
+}
+
+static void lapbeth_data_transmit(struct net_device *ndev, struct sk_buff *skb)
+{
+	struct lapbethdev *lapbeth = netdev_priv(ndev);
+	unsigned char *ptr;
+	struct net_device *dev;
+	int size = skb->len;
+
+	ptr = skb_push(skb, 2);
+
+	*ptr++ = size % 256;
+	*ptr++ = size / 256;
+
+	ndev->stats.tx_packets++;
+	ndev->stats.tx_bytes += size;
+
+	skb->dev = dev = lapbeth->ethdev;
+
+	skb->protocol = htons(ETH_P_DEC);
+
+	skb_reset_network_header(skb);
+
+	dev_hard_header(skb, dev, ETH_P_DEC, bcast_addr, NULL, 0);
+
+	dev_queue_xmit(skb);
+}
+
+static void lapbeth_connected(struct net_device *dev, int reason)
+{
+	struct lapbethdev *lapbeth = netdev_priv(dev);
+	unsigned char *ptr;
+	struct sk_buff *skb = __dev_alloc_skb(1, GFP_ATOMIC | __GFP_NOMEMALLOC);
+
+	if (!skb)
+		return;
+
+	ptr  = skb_put(skb, 1);
+	*ptr = X25_IFACE_CONNECT;
+
+	skb->protocol = x25_type_trans(skb, dev);
+
+	skb_queue_tail(&lapbeth->rx_queue, skb);
+	napi_schedule(&lapbeth->napi);
+}
+
+static void lapbeth_disconnected(struct net_device *dev, int reason)
+{
+	struct lapbethdev *lapbeth = netdev_priv(dev);
+	unsigned char *ptr;
+	struct sk_buff *skb = __dev_alloc_skb(1, GFP_ATOMIC | __GFP_NOMEMALLOC);
+
+	if (!skb)
+		return;
+
+	ptr  = skb_put(skb, 1);
+	*ptr = X25_IFACE_DISCONNECT;
+
+	skb->protocol = x25_type_trans(skb, dev);
+
+	skb_queue_tail(&lapbeth->rx_queue, skb);
+	napi_schedule(&lapbeth->napi);
+}
+
+/*	Set AX.25 callsign
+ */
+static int lapbeth_set_mac_address(struct net_device *dev, void *addr)
+{
+	struct sockaddr *sa = addr;
+
+	dev_addr_set(dev, sa->sa_data);
+	return 0;
+}
+
+static const struct lapb_register_struct lapbeth_callbacks = {
+	.connect_confirmation    = lapbeth_connected,
+	.connect_indication      = lapbeth_connected,
+	.disconnect_confirmation = lapbeth_disconnected,
+	.disconnect_indication   = lapbeth_disconnected,
+	.data_indication         = lapbeth_data_indication,
+	.data_transmit           = lapbeth_data_transmit,
+};
+
+/* open/close a device
+ */
+static int lapbeth_open(struct net_device *dev)
+{
+	struct lapbethdev *lapbeth = netdev_priv(dev);
+	int err;
+
+	napi_enable(&lapbeth->napi);
+
+	err = lapb_register(dev, &lapbeth_callbacks);
+	if (err != LAPB_OK) {
+		napi_disable(&lapbeth->napi);
+		pr_err("lapb_register error: %d\n", err);
+		return -ENODEV;
+	}
+
+	spin_lock_bh(&lapbeth->up_lock);
+	lapbeth->up = true;
+	spin_unlock_bh(&lapbeth->up_lock);
+
+	return 0;
+}
+
+static int lapbeth_close(struct net_device *dev)
+{
+	struct lapbethdev *lapbeth = netdev_priv(dev);
+	int err;
+
+	spin_lock_bh(&lapbeth->up_lock);
+	lapbeth->up = false;
+	spin_unlock_bh(&lapbeth->up_lock);
+
+	err = lapb_unregister(dev);
+	if (err != LAPB_OK)
+		pr_err("lapb_unregister error: %d\n", err);
+
+	napi_disable(&lapbeth->napi);
+
+	return 0;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static const struct net_device_ops lapbeth_netdev_ops = {
+	.ndo_open	     = lapbeth_open,
+	.ndo_stop	     = lapbeth_close,
+	.ndo_start_xmit	     = lapbeth_xmit,
+	.ndo_set_mac_address = lapbeth_set_mac_address,
+};
+
+static void lapbeth_setup(struct net_device *dev)
+{
+	dev->netdev_ops	     = &lapbeth_netdev_ops;
+	dev->needs_free_netdev = true;
+	dev->type            = ARPHRD_X25;
+	dev->hard_header_len = 0;
+	dev->mtu             = 1000;
+	dev->addr_len        = 0;
+}
+
+/*	Setup a new device.
+ */
+static int lapbeth_new_device(struct net_device *dev)
+{
+	struct net_device *ndev;
+	struct lapbethdev *lapbeth;
+	int rc = -ENOMEM;
+
+	ASSERT_RTNL();
+
+	if (dev->type != ARPHRD_ETHER)
+		return -EINVAL;
+
+	ndev = alloc_netdev(sizeof(*lapbeth), "lapb%d", NET_NAME_UNKNOWN,
+			    lapbeth_setup);
+	if (!ndev)
+		goto out;
+
+	/* When transmitting data:
+	 * first this driver removes a pseudo header of 1 byte,
+	 * then the lapb module prepends an LAPB header of at most 3 bytes,
+	 * then this driver prepends a length field of 2 bytes,
+	 * then the underlying Ethernet device prepends its own header.
+	 */
+	ndev->needed_headroom = -1 + 3 + 2 + dev->hard_header_len
+					   + dev->needed_headroom;
+	ndev->needed_tailroom = dev->needed_tailroom;
+
+	lapbeth = netdev_priv(ndev);
+	lapbeth->axdev = ndev;
+
+	dev_hold(dev);
+	lapbeth->ethdev = dev;
+
+	lapbeth->up = false;
+	spin_lock_init(&lapbeth->up_lock);
+
+	skb_queue_head_init(&lapbeth->rx_queue);
+	netif_napi_add_weight(ndev, &lapbeth->napi, lapbeth_napi_poll, 16);
+
+	rc = -EIO;
+	if (register_netdevice(ndev))
+		goto fail;
+
+	list_add_rcu(&lapbeth->node, &lapbeth_devices);
+	rc = 0;
+out:
+	return rc;
+fail:
+	dev_put(dev);
+	free_netdev(ndev);
+	goto out;
+}
+
+/*	Free a lapb network device.
+ */
+static void lapbeth_free_device(struct lapbethdev *lapbeth)
+{
+	dev_put(lapbeth->ethdev);
+	list_del_rcu(&lapbeth->node);
+	unregister_netdevice(lapbeth->axdev);
+}
+
+/*	Handle device status changes.
+ *
+ * Called from notifier with RTNL held.
+ */
+static int lapbeth_device_event(struct notifier_block *this,
+				unsigned long event, void *ptr)
+{
+	struct lapbethdev *lapbeth;
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	if (dev_net(dev) != &init_net)
+		return NOTIFY_DONE;
+
+	if (!dev_is_ethdev(dev) && !lapbeth_get_x25_dev(dev))
+		return NOTIFY_DONE;
+
+	switch (event) {
+	case NETDEV_UP:
+		/* New ethernet device -> new LAPB interface	 */
+		if (!lapbeth_get_x25_dev(dev))
+			lapbeth_new_device(dev);
+		break;
+	case NETDEV_GOING_DOWN:
+		/* ethernet device closes -> close LAPB interface */
+		lapbeth = lapbeth_get_x25_dev(dev);
+		if (lapbeth)
+			dev_close(lapbeth->axdev);
+		break;
+	case NETDEV_UNREGISTER:
+		/* ethernet device disappears -> remove LAPB interface */
+		lapbeth = lapbeth_get_x25_dev(dev);
+		if (lapbeth)
+			lapbeth_free_device(lapbeth);
+		break;
+	}
+
+	return NOTIFY_DONE;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static struct packet_type lapbeth_packet_type __read_mostly = {
+	.type = cpu_to_be16(ETH_P_DEC),
+	.func = lapbeth_rcv,
+};
+
+static struct notifier_block lapbeth_dev_notifier = {
+	.notifier_call = lapbeth_device_event,
+};
+
+static const char banner[] __initconst =
+	KERN_INFO "LAPB Ethernet driver version 0.02\n";
+
+static int __init lapbeth_init_driver(void)
+{
+	dev_add_pack(&lapbeth_packet_type);
+
+	register_netdevice_notifier(&lapbeth_dev_notifier);
+
+	printk(banner);
+
+	return 0;
+}
+module_init(lapbeth_init_driver);
+
+static void __exit lapbeth_cleanup_driver(void)
+{
+	struct lapbethdev *lapbeth;
+	struct list_head *entry, *tmp;
+
+	dev_remove_pack(&lapbeth_packet_type);
+	unregister_netdevice_notifier(&lapbeth_dev_notifier);
+
+	rtnl_lock();
+	list_for_each_safe(entry, tmp, &lapbeth_devices) {
+		lapbeth = list_entry(entry, struct lapbethdev, node);
+
+		dev_put(lapbeth->ethdev);
+		unregister_netdevice(lapbeth->axdev);
+	}
+	rtnl_unlock();
+}
+module_exit(lapbeth_cleanup_driver);
+
+MODULE_AUTHOR("Jonathan Naylor <g4klx@g4klx.demon.co.uk>");
+MODULE_DESCRIPTION("The unofficial LAPB over Ethernet driver");
+MODULE_LICENSE("GPL");