ff61772ceedd88362c35e9a9a550ca3cf1d8752a
[sfrench/cifs-2.6.git] / fs / ioctl.c
1 /*
2  *  linux/fs/ioctl.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  */
6
7 #include <linux/syscalls.h>
8 #include <linux/mm.h>
9 #include <linux/smp_lock.h>
10 #include <linux/capability.h>
11 #include <linux/file.h>
12 #include <linux/fs.h>
13 #include <linux/security.h>
14 #include <linux/module.h>
15
16 #include <asm/uaccess.h>
17 #include <asm/ioctls.h>
18
19 static long do_ioctl(struct file *filp, unsigned int cmd,
20                 unsigned long arg)
21 {
22         int error = -ENOTTY;
23
24         if (!filp->f_op)
25                 goto out;
26
27         if (filp->f_op->unlocked_ioctl) {
28                 error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
29                 if (error == -ENOIOCTLCMD)
30                         error = -EINVAL;
31                 goto out;
32         } else if (filp->f_op->ioctl) {
33                 lock_kernel();
34                 error = filp->f_op->ioctl(filp->f_path.dentry->d_inode,
35                                           filp, cmd, arg);
36                 unlock_kernel();
37         }
38
39  out:
40         return error;
41 }
42
43 static int file_ioctl(struct file *filp, unsigned int cmd,
44                 unsigned long arg)
45 {
46         int error;
47         int block;
48         struct inode * inode = filp->f_path.dentry->d_inode;
49         int __user *p = (int __user *)arg;
50
51         switch (cmd) {
52                 case FIBMAP:
53                 {
54                         struct address_space *mapping = filp->f_mapping;
55                         int res;
56                         /* do we support this mess? */
57                         if (!mapping->a_ops->bmap)
58                                 return -EINVAL;
59                         if (!capable(CAP_SYS_RAWIO))
60                                 return -EPERM;
61                         if ((error = get_user(block, p)) != 0)
62                                 return error;
63
64                         lock_kernel();
65                         res = mapping->a_ops->bmap(mapping, block);
66                         unlock_kernel();
67                         return put_user(res, p);
68                 }
69                 case FIGETBSZ:
70                         if (inode->i_sb == NULL)
71                                 return -EBADF;
72                         return put_user(inode->i_sb->s_blocksize, p);
73                 case FIONREAD:
74                         return put_user(i_size_read(inode) - filp->f_pos, p);
75         }
76
77         return do_ioctl(filp, cmd, arg);
78 }
79
80 /*
81  * When you add any new common ioctls to the switches above and below
82  * please update compat_sys_ioctl() too.
83  *
84  * vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
85  * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
86  */
87 int vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, unsigned long arg)
88 {
89         unsigned int flag;
90         int on, error = 0;
91
92         switch (cmd) {
93                 case FIOCLEX:
94                         set_close_on_exec(fd, 1);
95                         break;
96
97                 case FIONCLEX:
98                         set_close_on_exec(fd, 0);
99                         break;
100
101                 case FIONBIO:
102                         if ((error = get_user(on, (int __user *)arg)) != 0)
103                                 break;
104                         flag = O_NONBLOCK;
105 #ifdef __sparc__
106                         /* SunOS compatibility item. */
107                         if(O_NONBLOCK != O_NDELAY)
108                                 flag |= O_NDELAY;
109 #endif
110                         if (on)
111                                 filp->f_flags |= flag;
112                         else
113                                 filp->f_flags &= ~flag;
114                         break;
115
116                 case FIOASYNC:
117                         if ((error = get_user(on, (int __user *)arg)) != 0)
118                                 break;
119                         flag = on ? FASYNC : 0;
120
121                         /* Did FASYNC state change ? */
122                         if ((flag ^ filp->f_flags) & FASYNC) {
123                                 if (filp->f_op && filp->f_op->fasync) {
124                                         lock_kernel();
125                                         error = filp->f_op->fasync(fd, filp, on);
126                                         unlock_kernel();
127                                 }
128                                 else error = -ENOTTY;
129                         }
130                         if (error != 0)
131                                 break;
132
133                         if (on)
134                                 filp->f_flags |= FASYNC;
135                         else
136                                 filp->f_flags &= ~FASYNC;
137                         break;
138
139                 case FIOQSIZE:
140                         if (S_ISDIR(filp->f_path.dentry->d_inode->i_mode) ||
141                             S_ISREG(filp->f_path.dentry->d_inode->i_mode) ||
142                             S_ISLNK(filp->f_path.dentry->d_inode->i_mode)) {
143                                 loff_t res = inode_get_bytes(filp->f_path.dentry->d_inode);
144                                 error = copy_to_user((loff_t __user *)arg, &res, sizeof(res)) ? -EFAULT : 0;
145                         }
146                         else
147                                 error = -ENOTTY;
148                         break;
149                 default:
150                         if (S_ISREG(filp->f_path.dentry->d_inode->i_mode))
151                                 error = file_ioctl(filp, cmd, arg);
152                         else
153                                 error = do_ioctl(filp, cmd, arg);
154                         break;
155         }
156         return error;
157 }
158
159 asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
160 {
161         struct file * filp;
162         int error = -EBADF;
163         int fput_needed;
164
165         filp = fget_light(fd, &fput_needed);
166         if (!filp)
167                 goto out;
168
169         error = security_file_ioctl(filp, cmd, arg);
170         if (error)
171                 goto out_fput;
172
173         error = vfs_ioctl(filp, fd, cmd, arg);
174  out_fput:
175         fput_light(filp, fput_needed);
176  out:
177         return error;
178 }
179
180 /*
181  * Platforms implementing 32 bit compatibility ioctl handlers in
182  * modules need this exported
183  */
184 #ifdef CONFIG_COMPAT
185 EXPORT_SYMBOL(sys_ioctl);
186 #endif