control_compat.c

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/*
 * compat ioctls for control API
 *
 *   Copyright (c) by Takashi Iwai <[email protected]>
 *
 *   This program 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 program 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
 */

/* this file included from control.c */

#include <linux/compat.h>
#include <linux/slab.h>

struct snd_ctl_elem_list32 {
    u32 offset;
    u32 space;
    u32 used;
    u32 count;
    u32 pids;
    unsigned char reserved[50];
} /* don't set packed attribute here */;

static int snd_ctl_elem_list_compat(struct snd_card *card,
                    struct snd_ctl_elem_list32 __user *data32)
{
    struct snd_ctl_elem_list __user *data;
    compat_caddr_t ptr;
    int err;

    data = compat_alloc_user_space(sizeof(*data));

    /* offset, space, used, count */
    if (copy_in_user(data, data32, 4 * sizeof(u32)))
        return -EFAULT;
    /* pids */
    if (get_user(ptr, &data32->pids) ||
        put_user(compat_ptr(ptr), &data->pids))
        return -EFAULT;
    err = snd_ctl_elem_list(card, data);
    if (err < 0)
        return err;
    /* copy the result */
    if (copy_in_user(data32, data, 4 * sizeof(u32)))
        return -EFAULT;
    return 0;
}

/*
 * control element info
 * it uses union, so the things are not easy..
 */

struct snd_ctl_elem_info32 {
    struct snd_ctl_elem_id id; // the size of struct is same
    s32 type;
    u32 access;
    u32 count;
    s32 owner;
    union {
        struct {
            s32 min;
            s32 max;
            s32 step;
        } integer;
        struct {
            u64 min;
            u64 max;
            u64 step;
        } integer64;
        struct {
            u32 items;
            u32 item;
            char name[64];
            u64 names_ptr;
            u32 names_length;
        } enumerated;
        unsigned char reserved[128];
    } value;
    unsigned char reserved[64];
} __attribute__((packed));

static int snd_ctl_elem_info_compat(struct snd_ctl_file *ctl,
                    struct snd_ctl_elem_info32 __user *data32)
{
    struct snd_ctl_elem_info *data;
    int err;

    data = kzalloc(sizeof(*data), GFP_KERNEL);
    if (! data)
        return -ENOMEM;

    err = -EFAULT;
    /* copy id */
    if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
        goto error;
    /* we need to copy the item index.
     * hope this doesn't break anything..
     */
    if (get_user(data->value.enumerated.item, &data32->value.enumerated.item))
        goto error;

    snd_power_lock(ctl->card);
    err = snd_power_wait(ctl->card, SNDRV_CTL_POWER_D0);
    if (err >= 0)
        err = snd_ctl_elem_info(ctl, data);
    snd_power_unlock(ctl->card);

    if (err < 0)
        goto error;
    /* restore info to 32bit */
    err = -EFAULT;
    /* id, type, access, count */
    if (copy_to_user(&data32->id, &data->id, sizeof(data->id)) ||
        copy_to_user(&data32->type, &data->type, 3 * sizeof(u32)))
        goto error;
    if (put_user(data->owner, &data32->owner))
        goto error;
    switch (data->type) {
    case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
    case SNDRV_CTL_ELEM_TYPE_INTEGER:
        if (put_user(data->value.integer.min, &data32->value.integer.min) ||
            put_user(data->value.integer.max, &data32->value.integer.max) ||
            put_user(data->value.integer.step, &data32->value.integer.step))
            goto error;
        break;
    case SNDRV_CTL_ELEM_TYPE_INTEGER64:
        if (copy_to_user(&data32->value.integer64,
                 &data->value.integer64,
                 sizeof(data->value.integer64)))
            goto error;
        break;
    case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
        if (copy_to_user(&data32->value.enumerated,
                 &data->value.enumerated,
                 sizeof(data->value.enumerated)))
            goto error;
        break;
    default:
        break;
    }
    err = 0;
 error:
    kfree(data);
    return err;
}

/* read / write */
struct snd_ctl_elem_value32 {
    struct snd_ctl_elem_id id;
    unsigned int indirect;  /* bit-field causes misalignment */
        union {
        s32 integer[128];
        unsigned char data[512];
#ifndef CONFIG_X86_64
        s64 integer64[64];
#endif
        } value;
        unsigned char reserved[128];
};


/* get the value type and count of the control */
static int get_ctl_type(struct snd_card *card, struct snd_ctl_elem_id *id,
            int *countp)
{
    struct snd_kcontrol *kctl;
    struct snd_ctl_elem_info *info;
    int err;

    down_read(&card->controls_rwsem);
    kctl = snd_ctl_find_id(card, id);
    if (! kctl) {
        up_read(&card->controls_rwsem);
        return -ENXIO;
    }
    info = kzalloc(sizeof(*info), GFP_KERNEL);
    if (info == NULL) {
        up_read(&card->controls_rwsem);
        return -ENOMEM;
    }
    info->id = *id;
    err = kctl->info(kctl, info);
    up_read(&card->controls_rwsem);
    if (err >= 0) {
        err = info->type;
        *countp = info->count;
    }
    kfree(info);
    return err;
}

static int get_elem_size(int type, int count)
{
    switch (type) {
    case SNDRV_CTL_ELEM_TYPE_INTEGER64:
        return sizeof(s64) * count;
    case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
        return sizeof(int) * count;
    case SNDRV_CTL_ELEM_TYPE_BYTES:
        return 512;
    case SNDRV_CTL_ELEM_TYPE_IEC958:
        return sizeof(struct snd_aes_iec958);
    default:
        return -1;
    }
}

static int copy_ctl_value_from_user(struct snd_card *card,
                    struct snd_ctl_elem_value *data,
                    struct snd_ctl_elem_value32 __user *data32,
                    int *typep, int *countp)
{
    int i, type, size;
    int uninitialized_var(count);
    unsigned int indirect;

    if (copy_from_user(&data->id, &data32->id, sizeof(data->id)))
        return -EFAULT;
    if (get_user(indirect, &data32->indirect))
        return -EFAULT;
    if (indirect)
        return -EINVAL;
    type = get_ctl_type(card, &data->id, &count);
    if (type < 0)
        return type;

    if (type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
        type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
        for (i = 0; i < count; i++) {
            int val;
            if (get_user(val, &data32->value.integer[i]))
                return -EFAULT;
            data->value.integer.value[i] = val;
        }
    } else {
        size = get_elem_size(type, count);
        if (size < 0) {
            printk(KERN_ERR "snd_ioctl32_ctl_elem_value: unknown type %d\n", type);
            return -EINVAL;
        }
        if (copy_from_user(data->value.bytes.data,
                   data32->value.data, size))
            return -EFAULT;
    }

    *typep = type;
    *countp = count;
    return 0;
}

/* restore the value to 32bit */
static int copy_ctl_value_to_user(struct snd_ctl_elem_value32 __user *data32,
                  struct snd_ctl_elem_value *data,
                  int type, int count)
{
    int i, size;

    if (type == SNDRV_CTL_ELEM_TYPE_BOOLEAN ||
        type == SNDRV_CTL_ELEM_TYPE_INTEGER) {
        for (i = 0; i < count; i++) {
            int val;
            val = data->value.integer.value[i];
            if (put_user(val, &data32->value.integer[i]))
                return -EFAULT;
        }
    } else {
        size = get_elem_size(type, count);
        if (copy_to_user(data32->value.data,
                 data->value.bytes.data, size))
            return -EFAULT;
    }
    return 0;
}

static int snd_ctl_elem_read_user_compat(struct snd_card *card, 
                     struct snd_ctl_elem_value32 __user *data32)
{
    struct snd_ctl_elem_value *data;
    int err, type, count;

    data = kzalloc(sizeof(*data), GFP_KERNEL);
    if (data == NULL)
        return -ENOMEM;

    if ((err = copy_ctl_value_from_user(card, data, data32, &type, &count)) < 0)
        goto error;

    snd_power_lock(card);
    err = snd_power_wait(card, SNDRV_CTL_POWER_D0);
    if (err >= 0)
        err = snd_ctl_elem_read(card, data);
    snd_power_unlock(card);
    if (err >= 0)
        err = copy_ctl_value_to_user(data32, data, type, count);
 error:
    kfree(data);
    return err;
}

static int snd_ctl_elem_write_user_compat(struct snd_ctl_file *file,
                      struct snd_ctl_elem_value32 __user *data32)
{
    struct snd_ctl_elem_value *data;
    struct snd_card *card = file->card;
    int err, type, count;

    data = kzalloc(sizeof(*data), GFP_KERNEL);
    if (data == NULL)
        return -ENOMEM;

    if ((err = copy_ctl_value_from_user(card, data, data32, &type, &count)) < 0)
        goto error;

    snd_power_lock(card);
    err = snd_power_wait(card, SNDRV_CTL_POWER_D0);
    if (err >= 0)
        err = snd_ctl_elem_write(card, file, data);
    snd_power_unlock(card);
    if (err >= 0)
        err = copy_ctl_value_to_user(data32, data, type, count);
 error:
    kfree(data);
    return err;
}

/* add or replace a user control */
static int snd_ctl_elem_add_compat(struct snd_ctl_file *file,
                   struct snd_ctl_elem_info32 __user *data32,
                   int replace)
{
    struct snd_ctl_elem_info *data;
    int err;

    data = kzalloc(sizeof(*data), GFP_KERNEL);
    if (! data)
        return -ENOMEM;

    err = -EFAULT;
    /* id, type, access, count */ \
    if (copy_from_user(&data->id, &data32->id, sizeof(data->id)) ||
        copy_from_user(&data->type, &data32->type, 3 * sizeof(u32)))
        goto error;
    if (get_user(data->owner, &data32->owner) ||
        get_user(data->type, &data32->type))
        goto error;
    switch (data->type) {
    case SNDRV_CTL_ELEM_TYPE_BOOLEAN:
    case SNDRV_CTL_ELEM_TYPE_INTEGER:
        if (get_user(data->value.integer.min, &data32->value.integer.min) ||
            get_user(data->value.integer.max, &data32->value.integer.max) ||
            get_user(data->value.integer.step, &data32->value.integer.step))
            goto error;
        break;
    case SNDRV_CTL_ELEM_TYPE_INTEGER64:
        if (copy_from_user(&data->value.integer64,
                   &data32->value.integer64,
                   sizeof(data->value.integer64)))
            goto error;
        break;
    case SNDRV_CTL_ELEM_TYPE_ENUMERATED:
        if (copy_from_user(&data->value.enumerated,
                   &data32->value.enumerated,
                   sizeof(data->value.enumerated)))
            goto error;
        data->value.enumerated.names_ptr =
            (uintptr_t)compat_ptr(data->value.enumerated.names_ptr);
        break;
    default:
        break;
    }
    err = snd_ctl_elem_add(file, data, replace);
 error:
    kfree(data);
    return err;
}  

enum {
    SNDRV_CTL_IOCTL_ELEM_LIST32 = _IOWR('U', 0x10, struct snd_ctl_elem_list32),
    SNDRV_CTL_IOCTL_ELEM_INFO32 = _IOWR('U', 0x11, struct snd_ctl_elem_info32),
    SNDRV_CTL_IOCTL_ELEM_READ32 = _IOWR('U', 0x12, struct snd_ctl_elem_value32),
    SNDRV_CTL_IOCTL_ELEM_WRITE32 = _IOWR('U', 0x13, struct snd_ctl_elem_value32),
    SNDRV_CTL_IOCTL_ELEM_ADD32 = _IOWR('U', 0x17, struct snd_ctl_elem_info32),
    SNDRV_CTL_IOCTL_ELEM_REPLACE32 = _IOWR('U', 0x18, struct snd_ctl_elem_info32),
};

static inline long snd_ctl_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg)
{
    struct snd_ctl_file *ctl;
    struct snd_kctl_ioctl *p;
    void __user *argp = compat_ptr(arg);
    int err;

    ctl = file->private_data;
    if (snd_BUG_ON(!ctl || !ctl->card))
        return -ENXIO;

    switch (cmd) {
    case SNDRV_CTL_IOCTL_PVERSION:
    case SNDRV_CTL_IOCTL_CARD_INFO:
    case SNDRV_CTL_IOCTL_SUBSCRIBE_EVENTS:
    case SNDRV_CTL_IOCTL_POWER:
    case SNDRV_CTL_IOCTL_POWER_STATE:
    case SNDRV_CTL_IOCTL_ELEM_LOCK:
    case SNDRV_CTL_IOCTL_ELEM_UNLOCK:
    case SNDRV_CTL_IOCTL_ELEM_REMOVE:
    case SNDRV_CTL_IOCTL_TLV_READ:
    case SNDRV_CTL_IOCTL_TLV_WRITE:
    case SNDRV_CTL_IOCTL_TLV_COMMAND:
        return snd_ctl_ioctl(file, cmd, (unsigned long)argp);
    case SNDRV_CTL_IOCTL_ELEM_LIST32:
        return snd_ctl_elem_list_compat(ctl->card, argp);
    case SNDRV_CTL_IOCTL_ELEM_INFO32:
        return snd_ctl_elem_info_compat(ctl, argp);
    case SNDRV_CTL_IOCTL_ELEM_READ32:
        return snd_ctl_elem_read_user_compat(ctl->card, argp);
    case SNDRV_CTL_IOCTL_ELEM_WRITE32:
        return snd_ctl_elem_write_user_compat(ctl, argp);
    case SNDRV_CTL_IOCTL_ELEM_ADD32:
        return snd_ctl_elem_add_compat(ctl, argp, 0);
    case SNDRV_CTL_IOCTL_ELEM_REPLACE32:
        return snd_ctl_elem_add_compat(ctl, argp, 1);
    }

    down_read(&snd_ioctl_rwsem);
    list_for_each_entry(p, &snd_control_compat_ioctls, list) {
        if (p->fioctl) {
            err = p->fioctl(ctl->card, ctl, cmd, arg);
            if (err != -ENOIOCTLCMD) {
                up_read(&snd_ioctl_rwsem);
                return err;
            }
        }
    }
    up_read(&snd_ioctl_rwsem);
    return -ENOIOCTLCMD;
}