1 files changed, 535 insertions, 0 deletions
diff --git a/drivers/usb/usbip/stub_dev.c b/drivers/usb/usbip/stub_dev.c
new file mode 100644
index 000000000..4104eea03
--- /dev/null
+++ b/drivers/usb/usbip/stub_dev.c
@@ -0,0 +1,535 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ */
+
+#include <linux/device.h>
+#include <linux/file.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+
+#include "usbip_common.h"
+#include "stub.h"
+
+/*
+ * usbip_status shows the status of usbip-host as long as this driver is bound
+ * to the target device.
+ */
+static ssize_t usbip_status_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct stub_device *sdev = dev_get_drvdata(dev);
+	int status;
+
+	if (!sdev) {
+		dev_err(dev, "sdev is null\n");
+		return -ENODEV;
+	}
+
+	spin_lock_irq(&sdev->ud.lock);
+	status = sdev->ud.status;
+	spin_unlock_irq(&sdev->ud.lock);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", status);
+}
+static DEVICE_ATTR_RO(usbip_status);
+
+/*
+ * usbip_sockfd gets a socket descriptor of an established TCP connection that
+ * is used to transfer usbip requests by kernel threads. -1 is a magic number
+ * by which usbip connection is finished.
+ */
+static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct stub_device *sdev = dev_get_drvdata(dev);
+	int sockfd = 0;
+	struct socket *socket;
+	int rv;
+	struct task_struct *tcp_rx = NULL;
+	struct task_struct *tcp_tx = NULL;
+
+	if (!sdev) {
+		dev_err(dev, "sdev is null\n");
+		return -ENODEV;
+	}
+
+	rv = sscanf(buf, "%d", &sockfd);
+	if (rv != 1)
+		return -EINVAL;
+
+	if (sockfd != -1) {
+		int err;
+
+		dev_info(dev, "stub up\n");
+
+		mutex_lock(&sdev->ud.sysfs_lock);
+		spin_lock_irq(&sdev->ud.lock);
+
+		if (sdev->ud.status != SDEV_ST_AVAILABLE) {
+			dev_err(dev, "not ready\n");
+			goto err;
+		}
+
+		socket = sockfd_lookup(sockfd, &err);
+		if (!socket) {
+			dev_err(dev, "failed to lookup sock");
+			goto err;
+		}
+
+		if (socket->type != SOCK_STREAM) {
+			dev_err(dev, "Expecting SOCK_STREAM - found %d",
+				socket->type);
+			goto sock_err;
+		}
+
+		/* unlock and create threads and get tasks */
+		spin_unlock_irq(&sdev->ud.lock);
+		tcp_rx = kthread_create(stub_rx_loop, &sdev->ud, "stub_rx");
+		if (IS_ERR(tcp_rx)) {
+			sockfd_put(socket);
+			goto unlock_mutex;
+		}
+		tcp_tx = kthread_create(stub_tx_loop, &sdev->ud, "stub_tx");
+		if (IS_ERR(tcp_tx)) {
+			kthread_stop(tcp_rx);
+			sockfd_put(socket);
+			goto unlock_mutex;
+		}
+
+		/* get task structs now */
+		get_task_struct(tcp_rx);
+		get_task_struct(tcp_tx);
+
+		/* lock and update sdev->ud state */
+		spin_lock_irq(&sdev->ud.lock);
+		sdev->ud.tcp_socket = socket;
+		sdev->ud.sockfd = sockfd;
+		sdev->ud.tcp_rx = tcp_rx;
+		sdev->ud.tcp_tx = tcp_tx;
+		sdev->ud.status = SDEV_ST_USED;
+		spin_unlock_irq(&sdev->ud.lock);
+
+		wake_up_process(sdev->ud.tcp_rx);
+		wake_up_process(sdev->ud.tcp_tx);
+
+		mutex_unlock(&sdev->ud.sysfs_lock);
+
+	} else {
+		dev_info(dev, "stub down\n");
+
+		spin_lock_irq(&sdev->ud.lock);
+		if (sdev->ud.status != SDEV_ST_USED)
+			goto err;
+
+		spin_unlock_irq(&sdev->ud.lock);
+
+		usbip_event_add(&sdev->ud, SDEV_EVENT_DOWN);
+		mutex_unlock(&sdev->ud.sysfs_lock);
+	}
+
+	return count;
+
+sock_err:
+	sockfd_put(socket);
+err:
+	spin_unlock_irq(&sdev->ud.lock);
+unlock_mutex:
+	mutex_unlock(&sdev->ud.sysfs_lock);
+	return -EINVAL;
+}
+static DEVICE_ATTR_WO(usbip_sockfd);
+
+static struct attribute *usbip_attrs[] = {
+	&dev_attr_usbip_status.attr,
+	&dev_attr_usbip_sockfd.attr,
+	&dev_attr_usbip_debug.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(usbip);
+
+static void stub_shutdown_connection(struct usbip_device *ud)
+{
+	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
+
+	/*
+	 * When removing an exported device, kernel panic sometimes occurred
+	 * and then EIP was sk_wait_data of stub_rx thread. Is this because
+	 * sk_wait_data returned though stub_rx thread was already finished by
+	 * step 1?
+	 */
+	if (ud->tcp_socket) {
+		dev_dbg(&sdev->udev->dev, "shutdown sockfd %d\n", ud->sockfd);
+		kernel_sock_shutdown(ud->tcp_socket, SHUT_RDWR);
+	}
+
+	/* 1. stop threads */
+	if (ud->tcp_rx) {
+		kthread_stop_put(ud->tcp_rx);
+		ud->tcp_rx = NULL;
+	}
+	if (ud->tcp_tx) {
+		kthread_stop_put(ud->tcp_tx);
+		ud->tcp_tx = NULL;
+	}
+
+	/*
+	 * 2. close the socket
+	 *
+	 * tcp_socket is freed after threads are killed so that usbip_xmit does
+	 * not touch NULL socket.
+	 */
+	if (ud->tcp_socket) {
+		sockfd_put(ud->tcp_socket);
+		ud->tcp_socket = NULL;
+		ud->sockfd = -1;
+	}
+
+	/* 3. free used data */
+	stub_device_cleanup_urbs(sdev);
+
+	/* 4. free stub_unlink */
+	{
+		unsigned long flags;
+		struct stub_unlink *unlink, *tmp;
+
+		spin_lock_irqsave(&sdev->priv_lock, flags);
+		list_for_each_entry_safe(unlink, tmp, &sdev->unlink_tx, list) {
+			list_del(&unlink->list);
+			kfree(unlink);
+		}
+		list_for_each_entry_safe(unlink, tmp, &sdev->unlink_free,
+					 list) {
+			list_del(&unlink->list);
+			kfree(unlink);
+		}
+		spin_unlock_irqrestore(&sdev->priv_lock, flags);
+	}
+}
+
+static void stub_device_reset(struct usbip_device *ud)
+{
+	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
+	struct usb_device *udev = sdev->udev;
+	int ret;
+
+	dev_dbg(&udev->dev, "device reset");
+
+	ret = usb_lock_device_for_reset(udev, NULL);
+	if (ret < 0) {
+		dev_err(&udev->dev, "lock for reset\n");
+		spin_lock_irq(&ud->lock);
+		ud->status = SDEV_ST_ERROR;
+		spin_unlock_irq(&ud->lock);
+		return;
+	}
+
+	/* try to reset the device */
+	ret = usb_reset_device(udev);
+	usb_unlock_device(udev);
+
+	spin_lock_irq(&ud->lock);
+	if (ret) {
+		dev_err(&udev->dev, "device reset\n");
+		ud->status = SDEV_ST_ERROR;
+	} else {
+		dev_info(&udev->dev, "device reset\n");
+		ud->status = SDEV_ST_AVAILABLE;
+	}
+	spin_unlock_irq(&ud->lock);
+}
+
+static void stub_device_unusable(struct usbip_device *ud)
+{
+	spin_lock_irq(&ud->lock);
+	ud->status = SDEV_ST_ERROR;
+	spin_unlock_irq(&ud->lock);
+}
+
+/**
+ * stub_device_alloc - allocate a new stub_device struct
+ * @udev: usb_device of a new device
+ *
+ * Allocates and initializes a new stub_device struct.
+ */
+static struct stub_device *stub_device_alloc(struct usb_device *udev)
+{
+	struct stub_device *sdev;
+	int busnum = udev->bus->busnum;
+	int devnum = udev->devnum;
+
+	dev_dbg(&udev->dev, "allocating stub device");
+
+	/* yes, it's a new device */
+	sdev = kzalloc(sizeof(struct stub_device), GFP_KERNEL);
+	if (!sdev)
+		return NULL;
+
+	sdev->udev = usb_get_dev(udev);
+
+	/*
+	 * devid is defined with devnum when this driver is first allocated.
+	 * devnum may change later if a device is reset. However, devid never
+	 * changes during a usbip connection.
+	 */
+	sdev->devid		= (busnum << 16) | devnum;
+	sdev->ud.side		= USBIP_STUB;
+	sdev->ud.status		= SDEV_ST_AVAILABLE;
+	spin_lock_init(&sdev->ud.lock);
+	mutex_init(&sdev->ud.sysfs_lock);
+	sdev->ud.tcp_socket	= NULL;
+	sdev->ud.sockfd		= -1;
+
+	INIT_LIST_HEAD(&sdev->priv_init);
+	INIT_LIST_HEAD(&sdev->priv_tx);
+	INIT_LIST_HEAD(&sdev->priv_free);
+	INIT_LIST_HEAD(&sdev->unlink_free);
+	INIT_LIST_HEAD(&sdev->unlink_tx);
+	spin_lock_init(&sdev->priv_lock);
+
+	init_waitqueue_head(&sdev->tx_waitq);
+
+	sdev->ud.eh_ops.shutdown = stub_shutdown_connection;
+	sdev->ud.eh_ops.reset    = stub_device_reset;
+	sdev->ud.eh_ops.unusable = stub_device_unusable;
+
+	usbip_start_eh(&sdev->ud);
+
+	dev_dbg(&udev->dev, "register new device\n");
+
+	return sdev;
+}
+
+static void stub_device_free(struct stub_device *sdev)
+{
+	kfree(sdev);
+}
+
+static int stub_probe(struct usb_device *udev)
+{
+	struct stub_device *sdev = NULL;
+	const char *udev_busid = dev_name(&udev->dev);
+	struct bus_id_priv *busid_priv;
+	int rc = 0;
+	char save_status;
+
+	dev_dbg(&udev->dev, "Enter probe\n");
+
+	/* Not sure if this is our device. Allocate here to avoid
+	 * calling alloc while holding busid_table lock.
+	 */
+	sdev = stub_device_alloc(udev);
+	if (!sdev)
+		return -ENOMEM;
+
+	/* check we should claim or not by busid_table */
+	busid_priv = get_busid_priv(udev_busid);
+	if (!busid_priv || (busid_priv->status == STUB_BUSID_REMOV) ||
+	    (busid_priv->status == STUB_BUSID_OTHER)) {
+		dev_info(&udev->dev,
+			"%s is not in match_busid table... skip!\n",
+			udev_busid);
+
+		/*
+		 * Return value should be ENODEV or ENOXIO to continue trying
+		 * other matched drivers by the driver core.
+		 * See driver_probe_device() in driver/base/dd.c
+		 */
+		rc = -ENODEV;
+		if (!busid_priv)
+			goto sdev_free;
+
+		goto call_put_busid_priv;
+	}
+
+	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB) {
+		dev_dbg(&udev->dev, "%s is a usb hub device... skip!\n",
+			 udev_busid);
+		rc = -ENODEV;
+		goto call_put_busid_priv;
+	}
+
+	if (!strcmp(udev->bus->bus_name, "vhci_hcd")) {
+		dev_dbg(&udev->dev,
+			"%s is attached on vhci_hcd... skip!\n",
+			udev_busid);
+
+		rc = -ENODEV;
+		goto call_put_busid_priv;
+	}
+
+
+	dev_info(&udev->dev,
+		"usbip-host: register new device (bus %u dev %u)\n",
+		udev->bus->busnum, udev->devnum);
+
+	busid_priv->shutdown_busid = 0;
+
+	/* set private data to usb_device */
+	dev_set_drvdata(&udev->dev, sdev);
+
+	busid_priv->sdev = sdev;
+	busid_priv->udev = udev;
+
+	save_status = busid_priv->status;
+	busid_priv->status = STUB_BUSID_ALLOC;
+
+	/* release the busid_lock */
+	put_busid_priv(busid_priv);
+
+	/*
+	 * Claim this hub port.
+	 * It doesn't matter what value we pass as owner
+	 * (struct dev_state) as long as it is unique.
+	 */
+	rc = usb_hub_claim_port(udev->parent, udev->portnum,
+			(struct usb_dev_state *) udev);
+	if (rc) {
+		dev_dbg(&udev->dev, "unable to claim port\n");
+		goto err_port;
+	}
+
+	return 0;
+
+err_port:
+	dev_set_drvdata(&udev->dev, NULL);
+
+	/* we already have busid_priv, just lock busid_lock */
+	spin_lock(&busid_priv->busid_lock);
+	busid_priv->sdev = NULL;
+	busid_priv->status = save_status;
+	spin_unlock(&busid_priv->busid_lock);
+	/* lock is released - go to free */
+	goto sdev_free;
+
+call_put_busid_priv:
+	/* release the busid_lock */
+	put_busid_priv(busid_priv);
+
+sdev_free:
+	usb_put_dev(udev);
+	stub_device_free(sdev);
+
+	return rc;
+}
+
+static void shutdown_busid(struct bus_id_priv *busid_priv)
+{
+	usbip_event_add(&busid_priv->sdev->ud, SDEV_EVENT_REMOVED);
+
+	/* wait for the stop of the event handler */
+	usbip_stop_eh(&busid_priv->sdev->ud);
+}
+
+/*
+ * called in usb_disconnect() or usb_deregister()
+ * but only if actconfig(active configuration) exists
+ */
+static void stub_disconnect(struct usb_device *udev)
+{
+	struct stub_device *sdev;
+	const char *udev_busid = dev_name(&udev->dev);
+	struct bus_id_priv *busid_priv;
+	int rc;
+
+	dev_dbg(&udev->dev, "Enter disconnect\n");
+
+	busid_priv = get_busid_priv(udev_busid);
+	if (!busid_priv) {
+		BUG();
+		return;
+	}
+
+	sdev = dev_get_drvdata(&udev->dev);
+
+	/* get stub_device */
+	if (!sdev) {
+		dev_err(&udev->dev, "could not get device");
+		/* release busid_lock */
+		put_busid_priv(busid_priv);
+		return;
+	}
+
+	dev_set_drvdata(&udev->dev, NULL);
+
+	/* release busid_lock before call to remove device files */
+	put_busid_priv(busid_priv);
+
+	/*
+	 * NOTE: rx/tx threads are invoked for each usb_device.
+	 */
+
+	/* release port */
+	rc = usb_hub_release_port(udev->parent, udev->portnum,
+				  (struct usb_dev_state *) udev);
+	/*
+	 * NOTE: If a HUB disconnect triggered disconnect of the down stream
+	 * device usb_hub_release_port will return -ENODEV so we can safely ignore
+	 * that error here.
+	 */
+	if (rc && (rc != -ENODEV)) {
+		dev_dbg(&udev->dev, "unable to release port (%i)\n", rc);
+		return;
+	}
+
+	/* If usb reset is called from event handler */
+	if (usbip_in_eh(current))
+		return;
+
+	/* we already have busid_priv, just lock busid_lock */
+	spin_lock(&busid_priv->busid_lock);
+	if (!busid_priv->shutdown_busid)
+		busid_priv->shutdown_busid = 1;
+	/* release busid_lock */
+	spin_unlock(&busid_priv->busid_lock);
+
+	/* shutdown the current connection */
+	shutdown_busid(busid_priv);
+
+	usb_put_dev(sdev->udev);
+
+	/* we already have busid_priv, just lock busid_lock */
+	spin_lock(&busid_priv->busid_lock);
+	/* free sdev */
+	busid_priv->sdev = NULL;
+	stub_device_free(sdev);
+
+	if (busid_priv->status == STUB_BUSID_ALLOC)
+		busid_priv->status = STUB_BUSID_ADDED;
+	/* release busid_lock */
+	spin_unlock(&busid_priv->busid_lock);
+	return;
+}
+
+#ifdef CONFIG_PM
+
+/* These functions need usb_port_suspend and usb_port_resume,
+ * which reside in drivers/usb/core/usb.h. Skip for now. */
+
+static int stub_suspend(struct usb_device *udev, pm_message_t message)
+{
+	dev_dbg(&udev->dev, "stub_suspend\n");
+
+	return 0;
+}
+
+static int stub_resume(struct usb_device *udev, pm_message_t message)
+{
+	dev_dbg(&udev->dev, "stub_resume\n");
+
+	return 0;
+}
+
+#endif	/* CONFIG_PM */
+
+struct usb_device_driver stub_driver = {
+	.name		= "usbip-host",
+	.probe		= stub_probe,
+	.disconnect	= stub_disconnect,
+#ifdef CONFIG_PM
+	.suspend	= stub_suspend,
+	.resume		= stub_resume,
+#endif
+	.supports_autosuspend	=	0,
+	.dev_groups	= usbip_groups,
+};