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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/ioctl.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 */
6
Linus Torvalds1da177e2005-04-16 15:20:36 -07007#include <linux/syscalls.h>
8#include <linux/mm.h>
9#include <linux/smp_lock.h>
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080010#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#include <linux/file.h>
12#include <linux/fs.h>
13#include <linux/security.h>
14#include <linux/module.h>
Erez Zadokc9845ff2008-02-07 00:13:23 -080015#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <asm/ioctls.h>
18
Erez Zadokdeb21db2008-02-07 00:13:25 -080019/**
20 * vfs_ioctl - call filesystem specific ioctl methods
21 * @filp: [in] open file to invoke ioctl method on
22 * @cmd: [in] ioctl command to execute
23 * @arg: [in/out] command-specific argument for ioctl
24 *
25 * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise
26 * invokes * filesystem specific ->ioctl method. If neither method exists,
27 * returns -ENOTTY.
28 *
29 * Returns 0 on success, -errno on error.
30 */
31long vfs_ioctl(struct file *filp, unsigned int cmd,
32 unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070033{
34 int error = -ENOTTY;
35
36 if (!filp->f_op)
37 goto out;
38
39 if (filp->f_op->unlocked_ioctl) {
40 error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
41 if (error == -ENOIOCTLCMD)
42 error = -EINVAL;
43 goto out;
Andrew Morton64d67d22007-07-15 23:41:02 -070044 } else if (filp->f_op->ioctl) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 lock_kernel();
Andrew Morton64d67d22007-07-15 23:41:02 -070046 error = filp->f_op->ioctl(filp->f_path.dentry->d_inode,
47 filp, cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 unlock_kernel();
49 }
50
51 out:
52 return error;
53}
54
Erez Zadokaa81a7c2008-02-07 00:13:25 -080055static int ioctl_fibmap(struct file *filp, int __user *p)
56{
57 struct address_space *mapping = filp->f_mapping;
58 int res, block;
59
60 /* do we support this mess? */
61 if (!mapping->a_ops->bmap)
62 return -EINVAL;
63 if (!capable(CAP_SYS_RAWIO))
64 return -EPERM;
65 res = get_user(block, p);
66 if (res)
67 return res;
68 lock_kernel();
69 res = mapping->a_ops->bmap(mapping, block);
70 unlock_kernel();
71 return put_user(res, p);
72}
73
Linus Torvalds1da177e2005-04-16 15:20:36 -070074static int file_ioctl(struct file *filp, unsigned int cmd,
75 unsigned long arg)
76{
Erez Zadokc9845ff2008-02-07 00:13:23 -080077 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 int __user *p = (int __user *)arg;
79
80 switch (cmd) {
Erez Zadokc9845ff2008-02-07 00:13:23 -080081 case FIBMAP:
Erez Zadokaa81a7c2008-02-07 00:13:25 -080082 return ioctl_fibmap(filp, p);
Erez Zadokc9845ff2008-02-07 00:13:23 -080083 case FIGETBSZ:
84 return put_user(inode->i_sb->s_blocksize, p);
85 case FIONREAD:
86 return put_user(i_size_read(inode) - filp->f_pos, p);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 }
88
Erez Zadokdeb21db2008-02-07 00:13:25 -080089 return vfs_ioctl(filp, cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090}
91
Erez Zadokaa81a7c2008-02-07 00:13:25 -080092static int ioctl_fionbio(struct file *filp, int __user *argp)
93{
94 unsigned int flag;
95 int on, error;
96
97 error = get_user(on, argp);
98 if (error)
99 return error;
100 flag = O_NONBLOCK;
101#ifdef __sparc__
102 /* SunOS compatibility item. */
103 if (O_NONBLOCK != O_NDELAY)
104 flag |= O_NDELAY;
105#endif
106 if (on)
107 filp->f_flags |= flag;
108 else
109 filp->f_flags &= ~flag;
110 return error;
111}
112
113static int ioctl_fioasync(unsigned int fd, struct file *filp,
114 int __user *argp)
115{
116 unsigned int flag;
117 int on, error;
118
119 error = get_user(on, argp);
120 if (error)
121 return error;
122 flag = on ? FASYNC : 0;
123
124 /* Did FASYNC state change ? */
125 if ((flag ^ filp->f_flags) & FASYNC) {
126 if (filp->f_op && filp->f_op->fasync) {
127 lock_kernel();
128 error = filp->f_op->fasync(fd, filp, on);
129 unlock_kernel();
130 } else
131 error = -ENOTTY;
132 }
133 if (error)
134 return error;
135
136 if (on)
137 filp->f_flags |= FASYNC;
138 else
139 filp->f_flags &= ~FASYNC;
140 return error;
141}
142
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143/*
144 * When you add any new common ioctls to the switches above and below
145 * please update compat_sys_ioctl() too.
146 *
Erez Zadokdeb21db2008-02-07 00:13:25 -0800147 * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
149 */
Erez Zadokdeb21db2008-02-07 00:13:25 -0800150int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
151 unsigned long arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152{
Erez Zadokaa81a7c2008-02-07 00:13:25 -0800153 int error = 0;
154 int __user *argp = (int __user *)arg;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156 switch (cmd) {
Erez Zadokc9845ff2008-02-07 00:13:23 -0800157 case FIOCLEX:
158 set_close_on_exec(fd, 1);
159 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160
Erez Zadokc9845ff2008-02-07 00:13:23 -0800161 case FIONCLEX:
162 set_close_on_exec(fd, 0);
163 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
Erez Zadokc9845ff2008-02-07 00:13:23 -0800165 case FIONBIO:
Erez Zadokaa81a7c2008-02-07 00:13:25 -0800166 error = ioctl_fionbio(filp, argp);
Erez Zadokc9845ff2008-02-07 00:13:23 -0800167 break;
168
169 case FIOASYNC:
Erez Zadokaa81a7c2008-02-07 00:13:25 -0800170 error = ioctl_fioasync(fd, filp, argp);
Erez Zadokc9845ff2008-02-07 00:13:23 -0800171 break;
172
173 case FIOQSIZE:
174 if (S_ISDIR(filp->f_path.dentry->d_inode->i_mode) ||
175 S_ISREG(filp->f_path.dentry->d_inode->i_mode) ||
176 S_ISLNK(filp->f_path.dentry->d_inode->i_mode)) {
177 loff_t res =
178 inode_get_bytes(filp->f_path.dentry->d_inode);
179 error = copy_to_user((loff_t __user *)arg, &res,
180 sizeof(res)) ? -EFAULT : 0;
181 } else
182 error = -ENOTTY;
183 break;
184 default:
185 if (S_ISREG(filp->f_path.dentry->d_inode->i_mode))
186 error = file_ioctl(filp, cmd, arg);
187 else
Erez Zadokdeb21db2008-02-07 00:13:25 -0800188 error = vfs_ioctl(filp, cmd, arg);
Erez Zadokc9845ff2008-02-07 00:13:23 -0800189 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 }
191 return error;
192}
193
194asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
195{
Erez Zadokc9845ff2008-02-07 00:13:23 -0800196 struct file *filp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197 int error = -EBADF;
198 int fput_needed;
199
200 filp = fget_light(fd, &fput_needed);
201 if (!filp)
202 goto out;
203
204 error = security_file_ioctl(filp, cmd, arg);
205 if (error)
206 goto out_fput;
207
Erez Zadokdeb21db2008-02-07 00:13:25 -0800208 error = do_vfs_ioctl(filp, fd, cmd, arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 out_fput:
210 fput_light(filp, fput_needed);
211 out:
212 return error;
213}