1 files changed, 434 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..a20bb2d04
--- /dev/null
+++ b/drivers/usb/usbip/stub_main.c
@@ -0,0 +1,434 @@
+// 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 spinlock_t 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));
+
+	spin_lock_init(&busid_table_lock);
+
+	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]) {
+			strlcpy(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;
+
+	/* 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;
+	}
+	return 0;
+}
+
+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");