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 */
27 static int coda_ioctl_permission(struct user_namespace *mnt_userns,
28 struct inode *inode, int mask);
29 static long coda_pioctl(struct file *filp, unsigned int cmd,
30 unsigned long user_data);
31
32 /* exported from this file */
33 const struct inode_operations coda_ioctl_inode_operations = {
34 .permission = coda_ioctl_permission,
35 .setattr = coda_setattr,
36 };
37
38 const struct file_operations coda_ioctl_operations = {
39 .unlocked_ioctl = coda_pioctl,
40 .llseek = noop_llseek,
41 };
42
43 /* the coda pioctl inode ops */
coda_ioctl_permission(struct user_namespace * mnt_userns,struct inode * inode,int mask)44 static 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
coda_pioctl(struct file * filp,unsigned int cmd,unsigned long user_data)50 static 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);
85 out:
86 path_put(&path);
87 return error;
88 }
89