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path: root/drivers/usb/usbip/stub_dev.c
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Diffstat (limited to 'drivers/usb/usbip/stub_dev.c')
-rw-r--r--drivers/usb/usbip/stub_dev.c535
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,
+};