diff options
Diffstat (limited to 'drivers/usb/usbip/stub_main.c')
| -rw-r--r-- | drivers/usb/usbip/stub_main.c | 430 |
1 files changed, 430 insertions, 0 deletions
diff --git a/drivers/usb/usbip/stub_main.c b/drivers/usb/usbip/stub_main.c new file mode 100644 index 000000000..e8c3131a8 --- /dev/null +++ b/drivers/usb/usbip/stub_main.c @@ -0,0 +1,430 @@ +// 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) +{ + int len; + char busid[BUSID_SIZE]; + + if (count < 5) + return -EINVAL; + + /* busid needs to include \0 termination */ + len = strlcpy(busid, buf + 4, BUSID_SIZE); + if (sizeof(busid) <= len) + 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.drvwrap.driver, + &driver_attr_match_busid); + if (ret) { + pr_err("driver_create_file failed\n"); + goto err_create_file; + } + + ret = driver_create_file(&stub_driver.drvwrap.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.drvwrap.driver, + &driver_attr_match_busid); + + driver_remove_file(&stub_driver.drvwrap.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"); |