fs/ioctl.c

   1 /*
   2  *  linux/fs/ioctl.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 #include <linux/mm.h>
   8 #include <linux/smp_lock.h>
   9 #include <linux/file.h>
  10 #include <linux/fs.h>
  11 #include <linux/security.h>
  12
  13 #include <asm/uaccess.h>
  14 #include <asm/ioctls.h>
  15
  16 static int file_ioctl(struct file *filp,unsigned int cmd,unsigned long arg)
  17 {
  18         int error;
  19         int block;
  20         struct inode * inode = filp->f_dentry->d_inode;
  21
  22         switch (cmd) {
  23                 case FIBMAP:
  24                 {
  25                         struct address_space *mapping = filp->f_mapping;
  26                         int res;
  27                         /* do we support this mess? */
  28                         if (!mapping->a_ops->bmap)
  29                                 return -EINVAL;
  30                         if (!capable(CAP_SYS_RAWIO))
  31                                 return -EPERM;
  32                         if ((error = get_user(block, (int *) arg)) != 0)
  33                                 return error;
  34
  35                         res = mapping->a_ops->bmap(mapping, block);
  36                         return put_user(res, (int *) arg);
  37                 }
  38                 case FIGETBSZ:
  39                         if (inode->i_sb == NULL)
  40                                 return -EBADF;
  41                         return put_user(inode->i_sb->s_blocksize, (int *) arg);
  42                 case FIONREAD:
  43                         return put_user(i_size_read(inode) - filp->f_pos, (int *) arg);
  44         }
  45         if (filp->f_op && filp->f_op->ioctl)
  46                 return filp->f_op->ioctl(inode, filp, cmd, arg);
  47         return -ENOTTY;
  48 }
  49
  50
  51 asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
  52 {
  53         struct file * filp;
  54         unsigned int flag;
  55         int on, error = -EBADF;
  56
  57         filp = fget(fd);
  58         if (!filp)
  59                 goto out;
  60
  61         error = security_file_ioctl(filp, cmd, arg);
  62         if (error) {
  63                 fput(filp);
  64                 goto out;
  65         }
  66
  67         lock_kernel();
  68         switch (cmd) {
  69                 case FIOCLEX:
  70                         set_close_on_exec(fd, 1);
  71                         break;
  72
  73                 case FIONCLEX:
  74                         set_close_on_exec(fd, 0);
  75                         break;
  76
  77                 case FIONBIO:
  78                         if ((error = get_user(on, (int __user *)arg)) != 0)
  79                                 break;
  80                         flag = O_NONBLOCK;
  81 #ifdef __sparc__
  82                         /* SunOS compatibility item. */
  83                         if(O_NONBLOCK != O_NDELAY)
  84                                 flag |= O_NDELAY;
  85 #endif
  86                         if (on)
  87                                 filp->f_flags |= flag;
  88                         else
  89                                 filp->f_flags &= ~flag;
  90                         break;
  91
  92                 case FIOASYNC:
  93                         if ((error = get_user(on, (int __user *)arg)) != 0)
  94                                 break;
  95                         flag = on ? FASYNC : 0;
  96
  97                         /* Did FASYNC state change ? */
  98                         if ((flag ^ filp->f_flags) & FASYNC) {
  99                                 if (filp->f_op && filp->f_op->fasync)
 100                                         error = filp->f_op->fasync(fd, filp, on);
 101                                 else error = -ENOTTY;
 102                         }
 103                         if (error != 0)
 104                                 break;
 105
 106                         if (on)
 107                                 filp->f_flags |= FASYNC;
 108                         else
 109                                 filp->f_flags &= ~FASYNC;
 110                         break;
 111
 112                 case FIOQSIZE:
 113                         if (S_ISDIR(filp->f_dentry->d_inode->i_mode) ||
 114                             S_ISREG(filp->f_dentry->d_inode->i_mode) ||
 115                             S_ISLNK(filp->f_dentry->d_inode->i_mode)) {
 116                                 loff_t res = inode_get_bytes(filp->f_dentry->d_inode);
 117                                 error = copy_to_user((loff_t __user *)arg, &res, sizeof(res)) ? -EFAULT : 0;
 118                         }
 119                         else
 120                                 error = -ENOTTY;
 121                         break;
 122                 default:
 123                         error = -ENOTTY;
 124                         if (S_ISREG(filp->f_dentry->d_inode->i_mode))
 125                                 error = file_ioctl(filp, cmd, arg);
 126                         else if (filp->f_op && filp->f_op->ioctl)
 127                                 error = filp->f_op->ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
 128         }
 129         unlock_kernel();
 130         fput(filp);
 131
 132 out:
 133         return error;
 134 }