/*
 * Copyright (C) 2003-2008 Takahiro Hirofuchi
 *
 * This is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
 * USA.
 */


#include "usbip_common.h"
#include "stub.h"

/* Version Information */
#define DRIVER_VERSION "1.0"
#define DRIVER_AUTHOR "Takahiro Hirofuchi"
#define DRIVER_DESC "Stub Driver for USB/IP"

/* stub_priv is allocated from stub_priv_cache */
struct kmem_cache *stub_priv_cache;

/*-------------------------------------------------------------------------*/

/* Define sysfs entries for the usbip driver */


/*
 * 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
#define BUSID_SIZE 20
static char busid_table[MAX_BUSID][BUSID_SIZE];
static spinlock_t busid_table_lock;


int match_busid(const char *busid)
{
        int i;

        spin_lock(&busid_table_lock);

        for (i = 0; i < MAX_BUSID; i++)
                if (busid_table[i][0])
                        if (!strncmp(busid_table[i], busid, BUSID_SIZE)) {
                                /* already registerd */
                                spin_unlock(&busid_table_lock);
                                return 0;
                        }

        spin_unlock(&busid_table_lock);

        return 1;
}

static ssize_t show_match_busid(struct device_driver *drv, char *buf)
{
        int i;
        char *out = buf;

        spin_lock(&busid_table_lock);

        for (i = 0; i < MAX_BUSID; i++)
                if (busid_table[i][0])
                        out += sprintf(out, "%s ", busid_table[i]);

        spin_unlock(&busid_table_lock);

        out += sprintf(out, "\n");

        return out - buf;
}

static int add_match_busid(char *busid)
{
        int i;

        if (!match_busid(busid))
                return 0;

        spin_lock(&busid_table_lock);

        for (i = 0; i < MAX_BUSID; i++)
                if (!busid_table[i][0]) {
                        strncpy(busid_table[i], busid, BUSID_SIZE);
                        spin_unlock(&busid_table_lock);
                        return 0;
                }

        spin_unlock(&busid_table_lock);

        return -1;
}

static int del_match_busid(char *busid)
{
        int i;

        spin_lock(&busid_table_lock);

        for (i = 0; i < MAX_BUSID; i++)
                if (!strncmp(busid_table[i], busid, BUSID_SIZE)) {
                        /* found */
                        memset(busid_table[i], 0, BUSID_SIZE);
                        spin_unlock(&busid_table_lock);
                        return 0;
                }

        spin_unlock(&busid_table_lock);

        return -1;
}

static ssize_t store_match_busid(struct device_driver *dev, const char *buf,
                size_t count)
{
        int len;
        char busid[BUSID_SIZE];

        if (count < 5)
                return -EINVAL;

        /* strnlen() does not include \0 */
        len = strnlen(buf + 4, BUSID_SIZE);

        /* busid needs to include \0 termination */
        if (!(len < BUSID_SIZE))
                return -EINVAL;

        strncpy(busid, buf + 4, BUSID_SIZE);


        if (!strncmp(buf, "add ", 4)) {
                if (add_match_busid(busid) < 0)
                        return -ENOMEM;
                else {
                        usbip_udbg("add busid %s\n", busid);
                        return count;
                }
        } else if (!strncmp(buf, "del ", 4)) {
                if (del_match_busid(busid) < 0)
                        return -ENODEV;
                else {
                        usbip_udbg("del busid %s\n", busid);
                        return count;
                }
        } else
                return -EINVAL;
}

static DRIVER_ATTR(match_busid, S_IRUSR|S_IWUSR, show_match_busid,
                                                        store_match_busid);



/*-------------------------------------------------------------------------*/

/* Cleanup functions used to free private data */

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(&priv->list);
                return priv;
        }

        return NULL;
}

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) {
                spin_unlock_irqrestore(&sdev->priv_lock, flags);
                return priv;
        }

        priv = stub_priv_pop_from_listhead(&sdev->priv_tx);
        if (priv) {
                spin_unlock_irqrestore(&sdev->priv_lock, flags);
                return priv;
        }

        priv = stub_priv_pop_from_listhead(&sdev->priv_free);
        if (priv) {
                spin_unlock_irqrestore(&sdev->priv_lock, flags);
                return priv;
        }

        spin_unlock_irqrestore(&sdev->priv_lock, flags);
        return NULL;
}

void stub_device_cleanup_urbs(struct stub_device *sdev)
{
        struct stub_priv *priv;

        usbip_udbg("free sdev %p\n", sdev);

        while ((priv = stub_priv_pop(sdev))) {
                struct urb *urb = priv->urb;

                usbip_udbg("   free urb %p\n", urb);
                usb_kill_urb(urb);

                kmem_cache_free(stub_priv_cache, priv);

                if (urb->transfer_buffer != NULL)
                        kfree(urb->transfer_buffer);

                if (urb->setup_packet != NULL)
                        kfree(urb->setup_packet);

                usb_free_urb(urb);
        }
}


/*-------------------------------------------------------------------------*/

static int __init usb_stub_init(void)
{
        int ret;

        stub_priv_cache = kmem_cache_create("stub_priv",
                                            sizeof(struct stub_priv), 0,
                                            SLAB_HWCACHE_ALIGN, NULL);

        if (!stub_priv_cache) {
                printk(KERN_ERR KBUILD_MODNAME
                       ": create stub_priv_cache error\n");
                return -ENOMEM;
        }

        ret = usb_register(&stub_driver);
        if (ret) {
                printk(KERN_ERR KBUILD_MODNAME ": usb_register failed %d\n",
                       ret);
                goto error_usb_register;
        }

        printk(KERN_INFO KBUILD_MODNAME ":"
               DRIVER_DESC ":" DRIVER_VERSION "\n");

        memset(busid_table, 0, sizeof(busid_table));
        spin_lock_init(&busid_table_lock);

        ret = driver_create_file(&stub_driver.drvwrap.driver,
                                 &driver_attr_match_busid);

        if (ret) {
                printk(KERN_ERR KBUILD_MODNAME ": create driver sysfs\n");
                goto error_create_file;
        }

        return ret;
error_create_file:
        usb_deregister(&stub_driver);
error_usb_register:
        kmem_cache_destroy(stub_priv_cache);
        return ret;
}

static void __exit usb_stub_exit(void)
{
        driver_remove_file(&stub_driver.drvwrap.driver,
                           &driver_attr_match_busid);

        /*
         * deregister() calls stub_disconnect() for all devices. Device
         * specific data is cleared in stub_disconnect().
         */
        usb_deregister(&stub_driver);

        kmem_cache_destroy(stub_priv_cache);
}

module_init(usb_stub_init);
module_exit(usb_stub_exit);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");