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