LXR linux/fs/coda/pioctl.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Pioctl operations for Coda.
   4 * Original version: (C) 1996 Peter Braam
   5 * Rewritten for Linux 2.1: (C) 1997 Carnegie Mellon University
   6 *
   7 * Carnegie Mellon encourages users of this code to contribute improvements
   8 * to the Coda project. Contact Peter Braam <coda@cs.cmu.edu>.
   9 */
  10
  11#include <linux/types.h>
  12#include <linux/kernel.h>
  13#include <linux/time.h>
  14#include <linux/fs.h>
  15#include <linux/stat.h>
  16#include <linux/errno.h>
  17#include <linux/string.h>
  18#include <linux/namei.h>
  19#include <linux/module.h>
  20#include <linux/uaccess.h>
  21
  22#include <linux/coda.h>
  23#include "coda_psdev.h"
  24#include "coda_linux.h"
  25
  26/* pioctl ops */
  27static int coda_ioctl_permission(struct user_namespace *mnt_userns,
  28                                 struct inode *inode, int mask);
  29static long coda_pioctl(struct file *filp, unsigned int cmd,
  30                        unsigned long user_data);
  31
  32/* exported from this file */
  33const struct inode_operations coda_ioctl_inode_operations = {
  34        .permission     = coda_ioctl_permission,
  35        .setattr        = coda_setattr,
  36};
  37
  38const struct file_operations coda_ioctl_operations = {
  39        .unlocked_ioctl = coda_pioctl,
  40        .llseek         = noop_llseek,
  41};
  42
  43/* the coda pioctl inode ops */
  44static int coda_ioctl_permission(struct user_namespace *mnt_userns,
  45                                 struct inode *inode, int mask)
  46{
  47        return (mask & MAY_EXEC) ? -EACCES : 0;
  48}
  49
  50static long coda_pioctl(struct file *filp, unsigned int cmd,
  51                        unsigned long user_data)
  52{
  53        struct path path;
  54        int error;
  55        struct PioctlData data;
  56        struct inode *inode = file_inode(filp);
  57        struct inode *target_inode = NULL;
  58        struct coda_inode_info *cnp;
  59
  60        /* get the Pioctl data arguments from user space */
  61        if (copy_from_user(&data, (void __user *)user_data, sizeof(data)))
  62                return -EINVAL;
  63
  64        /*
  65         * Look up the pathname. Note that the pathname is in
  66         * user memory, and namei takes care of this
  67         */
  68        error = user_path_at(AT_FDCWD, data.path,
  69                             data.follow ? LOOKUP_FOLLOW : 0, &path);
  70        if (error)
  71                return error;
  72
  73        target_inode = d_inode(path.dentry);
  74
  75        /* return if it is not a Coda inode */
  76        if (target_inode->i_sb != inode->i_sb) {
  77                error = -EINVAL;
  78                goto out;
  79        }
  80
  81        /* now proceed to make the upcall */
  82        cnp = ITOC(target_inode);
  83
  84        error = venus_pioctl(inode->i_sb, &(cnp->c_fid), cmd, &data);
  85out:
  86        path_put(&path);
  87        return error;
  88}
  89