ioctl.c

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/*
 *  linux/fs/hfsplus/ioctl.c
 *
 * Copyright (C) 2003
 * Ethan Benson <[email protected]>
 * partially derived from linux/fs/ext2/ioctl.c
 * Copyright (C) 1993, 1994, 1995
 * Remy Card ([email protected])
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 * hfsplus ioctls
 */

#include <linux/capability.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/sched.h>
#include <linux/xattr.h>
#include <asm/uaccess.h>
#include "hfsplus_fs.h"

/*
 * "Blessing" an HFS+ filesystem writes metadata to the superblock informing
 * the platform firmware which file to boot from
 */
static int hfsplus_ioctl_bless(struct file *file, int __user *user_flags)
{
    struct dentry *dentry = file->f_path.dentry;
    struct inode *inode = dentry->d_inode;
    struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb);
    struct hfsplus_vh *vh = sbi->s_vhdr;
    struct hfsplus_vh *bvh = sbi->s_backup_vhdr;
    u32 cnid = (unsigned long)dentry->d_fsdata;

    if (!capable(CAP_SYS_ADMIN))
        return -EPERM;

    mutex_lock(&sbi->vh_mutex);

    /* Directory containing the bootable system */
    vh->finder_info[0] = bvh->finder_info[0] =
        cpu_to_be32(parent_ino(dentry));

    /*
     * Bootloader. Just using the inode here breaks in the case of
     * hard links - the firmware wants the ID of the hard link file,
     * but the inode points at the indirect inode
     */
    vh->finder_info[1] = bvh->finder_info[1] = cpu_to_be32(cnid);

    /* Per spec, the OS X system folder - same as finder_info[0] here */
    vh->finder_info[5] = bvh->finder_info[5] =
        cpu_to_be32(parent_ino(dentry));

    mutex_unlock(&sbi->vh_mutex);
    return 0;
}

static int hfsplus_ioctl_getflags(struct file *file, int __user *user_flags)
{
    struct inode *inode = file->f_path.dentry->d_inode;
    struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
    unsigned int flags = 0;

    if (inode->i_flags & S_IMMUTABLE)
        flags |= FS_IMMUTABLE_FL;
    if (inode->i_flags & S_APPEND)
        flags |= FS_APPEND_FL;
    if (hip->userflags & HFSPLUS_FLG_NODUMP)
        flags |= FS_NODUMP_FL;

    return put_user(flags, user_flags);
}

static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
{
    struct inode *inode = file->f_path.dentry->d_inode;
    struct hfsplus_inode_info *hip = HFSPLUS_I(inode);
    unsigned int flags;
    int err = 0;

    err = mnt_want_write_file(file);
    if (err)
        goto out;

    if (!inode_owner_or_capable(inode)) {
        err = -EACCES;
        goto out_drop_write;
    }

    if (get_user(flags, user_flags)) {
        err = -EFAULT;
        goto out_drop_write;
    }

    mutex_lock(&inode->i_mutex);

    if ((flags & (FS_IMMUTABLE_FL|FS_APPEND_FL)) ||
        inode->i_flags & (S_IMMUTABLE|S_APPEND)) {
        if (!capable(CAP_LINUX_IMMUTABLE)) {
            err = -EPERM;
            goto out_unlock_inode;
        }
    }

    /* don't silently ignore unsupported ext2 flags */
    if (flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) {
        err = -EOPNOTSUPP;
        goto out_unlock_inode;
    }

    if (flags & FS_IMMUTABLE_FL)
        inode->i_flags |= S_IMMUTABLE;
    else
        inode->i_flags &= ~S_IMMUTABLE;

    if (flags & FS_APPEND_FL)
        inode->i_flags |= S_APPEND;
    else
        inode->i_flags &= ~S_APPEND;

    if (flags & FS_NODUMP_FL)
        hip->userflags |= HFSPLUS_FLG_NODUMP;
    else
        hip->userflags &= ~HFSPLUS_FLG_NODUMP;

    inode->i_ctime = CURRENT_TIME_SEC;
    mark_inode_dirty(inode);

out_unlock_inode:
    mutex_unlock(&inode->i_mutex);
out_drop_write:
    mnt_drop_write_file(file);
out:
    return err;
}

long hfsplus_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
    void __user *argp = (void __user *)arg;

    switch (cmd) {
    case HFSPLUS_IOC_EXT2_GETFLAGS:
        return hfsplus_ioctl_getflags(file, argp);
    case HFSPLUS_IOC_EXT2_SETFLAGS:
        return hfsplus_ioctl_setflags(file, argp);
    case HFSPLUS_IOC_BLESS:
        return hfsplus_ioctl_bless(file, argp);
    default:
        return -ENOTTY;
    }
}

int hfsplus_setxattr(struct dentry *dentry, const char *name,
             const void *value, size_t size, int flags)
{
    struct inode *inode = dentry->d_inode;
    struct hfs_find_data fd;
    hfsplus_cat_entry entry;
    struct hfsplus_cat_file *file;
    int res;

    if (!S_ISREG(inode->i_mode) || HFSPLUS_IS_RSRC(inode))
        return -EOPNOTSUPP;

    res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
    if (res)
        return res;
    res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
    if (res)
        goto out;
    hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
            sizeof(struct hfsplus_cat_file));
    file = &entry.file;

    if (!strcmp(name, "hfs.type")) {
        if (size == 4)
            memcpy(&file->user_info.fdType, value, 4);
        else
            res = -ERANGE;
    } else if (!strcmp(name, "hfs.creator")) {
        if (size == 4)
            memcpy(&file->user_info.fdCreator, value, 4);
        else
            res = -ERANGE;
    } else
        res = -EOPNOTSUPP;
    if (!res) {
        hfs_bnode_write(fd.bnode, &entry, fd.entryoffset,
                sizeof(struct hfsplus_cat_file));
        hfsplus_mark_inode_dirty(inode, HFSPLUS_I_CAT_DIRTY);
    }
out:
    hfs_find_exit(&fd);
    return res;
}

ssize_t hfsplus_getxattr(struct dentry *dentry, const char *name,
             void *value, size_t size)
{
    struct inode *inode = dentry->d_inode;
    struct hfs_find_data fd;
    hfsplus_cat_entry entry;
    struct hfsplus_cat_file *file;
    ssize_t res = 0;

    if (!S_ISREG(inode->i_mode) || HFSPLUS_IS_RSRC(inode))
        return -EOPNOTSUPP;

    if (size) {
        res = hfs_find_init(HFSPLUS_SB(inode->i_sb)->cat_tree, &fd);
        if (res)
            return res;
        res = hfsplus_find_cat(inode->i_sb, inode->i_ino, &fd);
        if (res)
            goto out;
        hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
                sizeof(struct hfsplus_cat_file));
    }
    file = &entry.file;

    if (!strcmp(name, "hfs.type")) {
        if (size >= 4) {
            memcpy(value, &file->user_info.fdType, 4);
            res = 4;
        } else
            res = size ? -ERANGE : 4;
    } else if (!strcmp(name, "hfs.creator")) {
        if (size >= 4) {
            memcpy(value, &file->user_info.fdCreator, 4);
            res = 4;
        } else
            res = size ? -ERANGE : 4;
    } else
        res = -EOPNOTSUPP;
out:
    if (size)
        hfs_find_exit(&fd);
    return res;
}

#define HFSPLUS_ATTRLIST_SIZE (sizeof("hfs.creator")+sizeof("hfs.type"))

ssize_t hfsplus_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
    struct inode *inode = dentry->d_inode;

    if (!S_ISREG(inode->i_mode) || HFSPLUS_IS_RSRC(inode))
        return -EOPNOTSUPP;

    if (!buffer || !size)
        return HFSPLUS_ATTRLIST_SIZE;
    if (size < HFSPLUS_ATTRLIST_SIZE)
        return -ERANGE;
    strcpy(buffer, "hfs.type");
    strcpy(buffer + sizeof("hfs.type"), "hfs.creator");

    return HFSPLUS_ATTRLIST_SIZE;
}