fs/ioctl.c

   1 /*
   2  *  linux/fs/ioctl.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 #include <linux/config.h>
   8 #include <linux/syscalls.h>
   9 #include <linux/mm.h>
  10 #include <linux/smp_lock.h>
  11 #include <linux/capability.h>
  12 #include <linux/file.h>
  13 #include <linux/fs.h>
  14 #include <linux/security.h>
  15 #include <linux/module.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/vserver/inode.h>
  18 #include <linux/vserver/xid.h>
  19
  20 #include <asm/uaccess.h>
  21 #include <asm/ioctls.h>
  22
  23
  24 #ifdef  CONFIG_VSERVER_LEGACY
  25 extern int vx_proc_ioctl(struct inode *, struct file *,
  26         unsigned int, unsigned long);
  27 #endif
  28
  29 static long do_ioctl(struct file *filp, unsigned int cmd,
  30                 unsigned long arg)
  31 {
  32         int error = -ENOTTY;
  33
  34         if (!filp->f_op)
  35                 goto out;
  36
  37         if (filp->f_op->unlocked_ioctl) {
  38                 error = filp->f_op->unlocked_ioctl(filp, cmd, arg);
  39                 if (error == -ENOIOCTLCMD)
  40                         error = -EINVAL;
  41                 goto out;
  42         } else if (filp->f_op->ioctl) {
  43                 lock_kernel();
  44                 error = filp->f_op->ioctl(filp->f_dentry->d_inode,
  45                                           filp, cmd, arg);
  46                 unlock_kernel();
  47         }
  48
  49  out:
  50         return error;
  51 }
  52
  53 static int file_ioctl(struct file *filp, unsigned int cmd,
  54                 unsigned long arg)
  55 {
  56         int error;
  57         int block;
  58         struct inode * inode = filp->f_dentry->d_inode;
  59         int __user *p = (int __user *)arg;
  60
  61         switch (cmd) {
  62                 case FIBMAP:
  63                 {
  64                         struct address_space *mapping = filp->f_mapping;
  65                         int res;
  66                         /* do we support this mess? */
  67                         if (!mapping->a_ops->bmap)
  68                                 return -EINVAL;
  69                         if (!capable(CAP_SYS_RAWIO))
  70                                 return -EPERM;
  71                         if ((error = get_user(block, p)) != 0)
  72                                 return error;
  73
  74                         lock_kernel();
  75                         res = mapping->a_ops->bmap(mapping, block);
  76                         unlock_kernel();
  77                         return put_user(res, p);
  78                 }
  79                 case FIGETBSZ:
  80                         if (inode->i_sb == NULL)
  81                                 return -EBADF;
  82                         return put_user(inode->i_sb->s_blocksize, p);
  83                 case FIONREAD:
  84                         return put_user(i_size_read(inode) - filp->f_pos, p);
  85         }
  86
  87         return do_ioctl(filp, cmd, arg);
  88 }
  89
  90 /*
  91  * When you add any new common ioctls to the switches above and below
  92  * please update compat_sys_ioctl() too.
  93  *
  94  * vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
  95  * It's just a simple helper for sys_ioctl and compat_sys_ioctl.
  96  */
  97 int vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, unsigned long arg)
  98 {
  99         unsigned int flag;
 100         int on, error = 0;
 101
 102         switch (cmd) {
 103                 case FIOCLEX:
 104                         set_close_on_exec(fd, 1);
 105                         break;
 106
 107                 case FIONCLEX:
 108                         set_close_on_exec(fd, 0);
 109                         break;
 110
 111                 case FIONBIO:
 112                         if ((error = get_user(on, (int __user *)arg)) != 0)
 113                                 break;
 114                         flag = O_NONBLOCK;
 115 #ifdef __sparc__
 116                         /* SunOS compatibility item. */
 117                         if(O_NONBLOCK != O_NDELAY)
 118                                 flag |= O_NDELAY;
 119 #endif
 120                         if (on)
 121                                 filp->f_flags |= flag;
 122                         else
 123                                 filp->f_flags &= ~flag;
 124                         break;
 125
 126                 case FIOASYNC:
 127                         if ((error = get_user(on, (int __user *)arg)) != 0)
 128                                 break;
 129                         flag = on ? FASYNC : 0;
 130
 131                         /* Did FASYNC state change ? */
 132                         if ((flag ^ filp->f_flags) & FASYNC) {
 133                                 if (filp->f_op && filp->f_op->fasync) {
 134                                         lock_kernel();
 135                                         error = filp->f_op->fasync(fd, filp, on);
 136                                         unlock_kernel();
 137                                 }
 138                                 else error = -ENOTTY;
 139                         }
 140                         if (error != 0)
 141                                 break;
 142
 143                         if (on)
 144                                 filp->f_flags |= FASYNC;
 145                         else
 146                                 filp->f_flags &= ~FASYNC;
 147                         break;
 148
 149                 case FIOQSIZE:
 150                         if (S_ISDIR(filp->f_dentry->d_inode->i_mode) ||
 151                             S_ISREG(filp->f_dentry->d_inode->i_mode) ||
 152                             S_ISLNK(filp->f_dentry->d_inode->i_mode)) {
 153                                 loff_t res = inode_get_bytes(filp->f_dentry->d_inode);
 154                                 error = copy_to_user((loff_t __user *)arg, &res, sizeof(res)) ? -EFAULT : 0;
 155                         }
 156                         else
 157                                 error = -ENOTTY;
 158                         break;
 159 #ifdef  CONFIG_VSERVER_LEGACY
 160 #ifndef CONFIG_INOXID_NONE
 161                 case FIOC_GETXID: {
 162                         struct inode *inode = filp->f_dentry->d_inode;
 163
 164                         /* fixme: if stealth, return -ENOTTY */
 165                         error = -EPERM;
 166                         if (capable(CAP_CONTEXT))
 167                                 error = put_user(inode->i_xid, (int __user *) arg);
 168                         break;
 169                 }
 170                 case FIOC_SETXID: {
 171                         struct inode *inode = filp->f_dentry->d_inode;
 172                         int xid;
 173
 174                         /* fixme: if stealth, return -ENOTTY */
 175                         error = -EPERM;
 176                         if (!capable(CAP_CONTEXT))
 177                                 break;
 178                         error = -EROFS;
 179                         if (IS_RDONLY(inode))
 180                                 break;
 181                         error = -ENOSYS;
 182                         if (!(inode->i_sb->s_flags & MS_TAGXID))
 183                                 break;
 184                         error = -EFAULT;
 185                         if (get_user(xid, (int __user *) arg))
 186                                 break;
 187                         error = 0;
 188                         inode->i_xid = (xid & 0xFFFF);
 189                         inode->i_ctime = CURRENT_TIME;
 190                         mark_inode_dirty(inode);
 191                         break;
 192                 }
 193 #endif
 194                 case FIOC_GETXFLG:
 195                 case FIOC_SETXFLG:
 196                         error = -ENOTTY;
 197                         if (filp->f_dentry->d_inode->i_sb->s_magic == PROC_SUPER_MAGIC)
 198                                 error = vx_proc_ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
 199                         break;
 200 #endif
 201                 default:
 202                         if (S_ISREG(filp->f_dentry->d_inode->i_mode))
 203                                 error = file_ioctl(filp, cmd, arg);
 204                         else
 205                                 error = do_ioctl(filp, cmd, arg);
 206                         break;
 207         }
 208         return error;
 209 }
 210
 211 asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
 212 {
 213         struct file * filp;
 214         int error = -EBADF;
 215         int fput_needed;
 216
 217         filp = fget_light(fd, &fput_needed);
 218         if (!filp)
 219                 goto out;
 220
 221         error = security_file_ioctl(filp, cmd, arg);
 222         if (error)
 223                 goto out_fput;
 224
 225         error = vfs_ioctl(filp, fd, cmd, arg);
 226  out_fput:
 227         fput_light(filp, fput_needed);
 228  out:
 229         return error;
 230 }
 231
 232 /*
 233  * Platforms implementing 32 bit compatibility ioctl handlers in
 234  * modules need this exported
 235  */
 236 #ifdef CONFIG_COMPAT
 237 EXPORT_SYMBOL(sys_ioctl);
 238 #endif