// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2003-2008 Takahiro Hirofuchi
*/
#include <linux/string.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/scatterlist.h>
#include "usbip_common.h"
#include "stub.h"
#define DRIVER_AUTHOR "Takahiro Hirofuchi"
#define DRIVER_DESC "USB/IP Host Driver"
struct kmem_cache *stub_priv_cache;
/*
* busid_tables defines matching busids that usbip can grab. A user can change
* dynamically what device is locally used and what device is exported to a
* remote host.
*/
#define MAX_BUSID 16
static struct bus_id_priv busid_table[MAX_BUSID];
static DEFINE_SPINLOCK(busid_table_lock);
static void init_busid_table(void)
{
int i;
/*
* This also sets the bus_table[i].status to
* STUB_BUSID_OTHER, which is 0.
*/
memset(busid_table, 0, sizeof(busid_table));
for (i = 0; i < MAX_BUSID; i++)
spin_lock_init(&busid_table[i].busid_lock);
}
/*
* Find the index of the busid by name.
* Must be called with busid_table_lock held.
*/
static int get_busid_idx(const char *busid)
{
int i;
int idx = -1;
for (i = 0; i < MAX_BUSID; i++) {
spin_lock(&busid_table[i].busid_lock);
if (busid_table[i].name[0])
if (!strncmp(busid_table[i].name, busid, BUSID_SIZE)) {
idx = i;
spin_unlock(&busid_table[i].busid_lock);
break;
}
spin_unlock(&busid_table[i].busid_lock);
}
return idx;
}
/* Returns holding busid_lock. Should call put_busid_priv() to unlock */
struct bus_id_priv *get_busid_priv(const char *busid)
{
int idx;
struct bus_id_priv *bid = NULL;
spin_lock(&busid_table_lock);
idx = get_busid_idx(busid);
if (idx >= 0) {
bid = &(busid_table[idx]);
/* get busid_lock before returning */
spin_lock(&bid->busid_lock);
}
spin_unlock(&busid_table_lock);
return bid;
}
void put_busid_priv(struct bus_id_priv *bid)
{
if (bid)
spin_unlock(&bid->busid_lock);
}
static int add_match_busid(char *busid)
{
int i;
int ret = -1;
spin_lock(&busid_table_lock);
/* already registered? */
if (get_busid_idx(busid) >= 0) {
ret = 0;
goto out;
}
for (i = 0; i < MAX_BUSID; i++) {
spin_lock(&busid_table[i].busid_lock);
if (!busid_table[i].name[0]) {
strscpy(busid_table[i].name, busid, BUSID_SIZE);
if ((busid_table[i].status != STUB_BUSID_ALLOC) &&
(busid_table[i].status != STUB_BUSID_REMOV))
busid_table[i].status = STUB_BUSID_ADDED;
ret = 0;
spin_unlock(&busid_table[i].busid_lock);
break;
}
spin_unlock(&busid_table[i].busid_lock);
}
out:
spin_unlock(&busid_table_lock);
return ret;
}
int del_match_busid(char *busid)
{
int idx;
int ret = -1;
spin_lock(&busid_table_lock);
idx = get_busid_idx(busid);
if (idx < 0)
goto out;
/* found */
ret = 0;
spin_lock(&busid_table[idx].busid_lock);
if (busid_table[idx].status == STUB_BUSID_OTHER)
memset(busid_table[idx].name, 0, BUSID_SIZE);
if ((busid_table[idx].status != STUB_BUSID_OTHER) &&
(busid_table[idx].status != STUB_BUSID_ADDED))
busid_table[idx].status = STUB_BUSID_REMOV;
spin_unlock(&busid_table[idx].busid_lock);
out:
spin_unlock(&busid_table_lock);
return ret;
}
static ssize_t match_busid_show(struct device_driver *drv, char *buf)
{
int i;
char *out = buf;
spin_lock(&busid_table_lock);
for (i = 0; i < MAX_BUSID; i++) {
spin_lock(&busid_table[i].busid_lock);
if (busid_table[i].name[0])
out += sprintf(out, "%s ", busid_table[i].name);
spin_unlock(&busid_table[i].busid_lock);
}
spin_unlock(&busid_table_lock);
out += sprintf(out, "\n");
return out - buf;
}
static ssize_t match_busid_store(struct device_driver *dev, const char *buf,
size_t count)
{
char busid[BUSID_SIZE];
if (count < 5)
return -EINVAL;
/* busid needs to include \0 termination */
if (strscpy(busid, buf + 4, BUSID_SIZE) < 0)
return -EINVAL;
if (!strncmp(buf, "add ", 4)) {
if (add_match_busid(busid) < 0)
return -ENOMEM;
pr_debug("add busid %s\n", busid);
return count;
}
if (!strncmp(buf, "del ", 4)) {
if (del_match_busid(busid) < 0)
return -ENODEV;
pr_debug("del busid %s\n", busid);
return count;
}
return -EINVAL;
}
static DRIVER_ATTR_RW(match_busid);
static int do_rebind(char *busid, struct bus_id_priv *busid_priv)
{
int ret = 0;
/* device_attach() callers should hold parent lock for USB */
if (busid_priv->udev->dev.parent)
device_lock(busid_priv->udev->dev.parent);
ret = device_attach(&busid_priv->udev->dev);
if (busid_priv->udev->dev.parent)
device_unlock(busid_priv->udev->dev.parent);
if (ret < 0)
dev_err(&busid_priv->udev->dev, "rebind failed\n");
return ret;
}
static void stub_device_rebind(void)
{
#if IS_MODULE(CONFIG_USBIP_HOST)
struct bus_id_priv *busid_priv;
int i;
/* update status to STUB_BUSID_OTHER so probe ignores the device */
spin_lock(&busid_table_lock);
for (i = 0; i < MAX_BUSID; i++) {
if (busid_table[i].name[0] &&
busid_table[i].shutdown_busid) {
busid_priv = &(busid_table[i]);
busid_priv->status = STUB_BUSID_OTHER;
}
}
spin_unlock(&busid_table_lock);
/* now run rebind - no need to hold locks. driver files are removed */
for (i = 0; i < MAX_BUSID; i++) {
if (busid_table[i].name[0] &&
busid_table[i].shutdown_busid) {
busid_priv = &(busid_table[i]);
do_rebind(busid_table[i].name, busid_priv);
}
}
#endif
}
static ssize_t rebind_store(struct device_driver *dev, const char *buf,
size_t count)
{
int ret;
int len;
struct bus_id_priv *bid;
/* buf length should be less that BUSID_SIZE */
len = strnlen(buf, BUSID_SIZE);
if (!(len < BUSID_SIZE))
return -EINVAL;
bid = get_busid_priv(buf);
if (!bid)
return -ENODEV;
/* mark the device for deletion so probe ignores it during rescan */
bid->status = STUB_BUSID_OTHER;
/* release the busid lock */
put_busid_priv(bid);
ret = do_rebind((char *) buf, bid);
if (ret < 0)
return ret;
/* delete device from busid_table */
del_match_busid((char *) buf);
return count;
}
static DRIVER_ATTR_WO(rebind);
static struct stub_priv *stub_priv_pop_from_listhead(struct list_head *listhead)
{
struct stub_priv *priv, *tmp;
list_for_each_entry_safe(priv, tmp, listhead, list) {
list_del_init(&priv->list);
return priv;
}
return NULL;
}
void stub_free_priv_and_urb(struct stub_priv *priv)
{
struct urb *urb;
int i;
for (i = 0; i < priv->num_urbs; i++) {
urb = priv->urbs[i];
if (!urb)
return;
kfree(urb->setup_packet);
urb->setup_packet = NULL;
if (urb->transfer_buffer && !priv->sgl) {
kfree(urb->transfer_buffer);
urb->transfer_buffer = NULL;
}
if (urb->num_sgs) {
sgl_free(urb->sg);
urb->sg = NULL;
urb->num_sgs = 0;
}
usb_free_urb(urb);
}
if (!list_empty(&priv->list))
list_del(&priv->list);
if (priv->sgl)
sgl_free(priv->sgl);
kfree(priv->urbs);
kmem_cache_free(stub_priv_cache, priv);
}
static struct stub_priv *stub_priv_pop(struct stub_device *sdev)
{
unsigned long flags;
struct stub_priv *priv;
spin_lock_irqsave(&sdev->priv_lock, flags);
priv = stub_priv_pop_from_listhead(&sdev->priv_init);
if (priv)
goto done;
priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
if (priv)
goto done;
priv = stub_priv_pop_from_listhead(&sdev->priv_free);
done:
spin_unlock_irqrestore(&sdev->priv_lock, flags);
return priv;
}
void stub_device_cleanup_urbs(struct stub_device *sdev)
{
struct stub_priv *priv;
int i;
dev_dbg(&sdev->udev->dev, "Stub device cleaning up urbs\n");
while ((priv = stub_priv_pop(sdev))) {
for (i = 0; i < priv->num_urbs; i++)
usb_kill_urb(priv->urbs[i]);
stub_free_priv_and_urb(priv);
}
}
static int __init usbip_host_init(void)
{
int ret;
init_busid_table();
stub_priv_cache = KMEM_CACHE(stub_priv, SLAB_HWCACHE_ALIGN);
if (!stub_priv_cache) {
pr_err("kmem_cache_create failed\n");
return -ENOMEM;
}
ret = usb_register_device_driver(&stub_driver, THIS_MODULE);
if (ret) {
pr_err("usb_register failed %d\n", ret);
goto err_usb_register;
}
ret = driver_create_file(&stub_driver.driver,
&driver_attr_match_busid);
if (ret) {
pr_err("driver_create_file failed\n");
goto err_create_file;
}
ret = driver_create_file(&stub_driver.driver,
&driver_attr_rebind);
if (ret) {
pr_err("driver_create_file failed\n");
goto err_create_file;
}
return ret;
err_create_file:
usb_deregister_device_driver(&stub_driver);
err_usb_register:
kmem_cache_destroy(stub_priv_cache);
return ret;
}
static void __exit usbip_host_exit(void)
{
driver_remove_file(&stub_driver.driver,
&driver_attr_match_busid);
driver_remove_file(&stub_driver.driver,
&driver_attr_rebind);
/*
* deregister() calls stub_disconnect() for all devices. Device
* specific data is cleared in stub_disconnect().
*/
usb_deregister_device_driver(&stub_driver);
/* initiate scan to attach devices */
stub_device_rebind();
kmem_cache_destroy(stub_priv_cache);
}
module_init(usbip_host_init);
module_exit(usbip_host_exit);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
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