// 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 sysfs_emit(buf, "%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");
mutex_lock(&sdev->ud.sysfs_lock);
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,
};
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