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 = inode->i_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(inode->i_size - 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         error = 0;
  61
  62         error = security_ops->file_ioctl(filp, cmd, arg);
  63         if (error) {
  64                 fput(filp);
  65                 goto out;
  66         }
  67
  68         lock_kernel();
  69         switch (cmd) {
  70                 case FIOCLEX:
  71                         set_close_on_exec(fd, 1);
  72                         break;
  73
  74                 case FIONCLEX:
  75                         set_close_on_exec(fd, 0);
  76                         break;
  77
  78                 case FIONBIO:
  79                         if ((error = get_user(on, (int *)arg)) != 0)
  80                                 break;
  81                         flag = O_NONBLOCK;
  82 #ifdef __sparc__
  83                         /* SunOS compatibility item. */
  84                         if(O_NONBLOCK != O_NDELAY)
  85                                 flag |= O_NDELAY;
  86 #endif
  87                         if (on)
  88                                 filp->f_flags |= flag;
  89                         else
  90                                 filp->f_flags &= ~flag;
  91                         break;
  92
  93                 case FIOASYNC:
  94                         if ((error = get_user(on, (int *)arg)) != 0)
  95                                 break;
  96                         flag = on ? FASYNC : 0;
  97
  98                         /* Did FASYNC state change ? */
  99                         if ((flag ^ filp->f_flags) & FASYNC) {
 100                                 if (filp->f_op && filp->f_op->fasync)
 101                                         error = filp->f_op->fasync(fd, filp, on);
 102                                 else error = -ENOTTY;
 103                         }
 104                         if (error != 0)
 105                                 break;
 106
 107                         if (on)
 108                                 filp->f_flags |= FASYNC;
 109                         else
 110                                 filp->f_flags &= ~FASYNC;
 111                         break;
 112
 113                 case FIOQSIZE:
 114                         if (S_ISDIR(filp->f_dentry->d_inode->i_mode) ||
 115                             S_ISREG(filp->f_dentry->d_inode->i_mode) ||
 116                             S_ISLNK(filp->f_dentry->d_inode->i_mode)) {
 117                                 loff_t res = inode_get_bytes(filp->f_dentry->d_inode);
 118                                 error = copy_to_user((loff_t *)arg, &res, sizeof(res)) ? -EFAULT : 0;
 119                         }
 120                         else
 121                                 error = -ENOTTY;
 122                         break;
 123                 default:
 124                         error = -ENOTTY;
 125                         if (S_ISREG(filp->f_dentry->d_inode->i_mode))
 126                                 error = file_ioctl(filp, cmd, arg);
 127                         else if (filp->f_op && filp->f_op->ioctl)
 128                                 error = filp->f_op->ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
 129         }
 130         unlock_kernel();
 131         fput(filp);
 132
 133 out:
 134         return error;
 135 }