/* * linux/fs/ioctl.c * * Copyright (C) 1991, 1992 Linus Torvalds */ #include <linux/syscalls.h> #include <linux/mm.h> #include <linux/smp_lock.h> #include <linux/capability.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/security.h> #include <linux/module.h> #include <linux/uaccess.h> #include <asm/ioctls.h> /** * vfs_ioctl - call filesystem specific ioctl methods * @filp: [in] open file to invoke ioctl method on * @cmd: [in] ioctl command to execute * @arg: [in/out] command-specific argument for ioctl * * Invokes filesystem specific ->unlocked_ioctl, if one exists; otherwise * invokes * filesystem specific ->ioctl method. If neither method exists, * returns -ENOTTY. * * Returns 0 on success, -errno on error. */ long vfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { int error = -ENOTTY; if (!filp->f_op) goto out; if (filp->f_op->unlocked_ioctl) { error = filp->f_op->unlocked_ioctl(filp, cmd, arg); if (error == -ENOIOCTLCMD) error = -EINVAL; goto out; } else if (filp->f_op->ioctl) { lock_kernel(); error = filp->f_op->ioctl(filp->f_path.dentry->d_inode, filp, cmd, arg); unlock_kernel(); } out: return error; } static int ioctl_fibmap(struct file *filp, int __user *p) { struct address_space *mapping = filp->f_mapping; int res, block; /* do we support this mess? */ if (!mapping->a_ops->bmap) return -EINVAL; if (!capable(CAP_SYS_RAWIO)) return -EPERM; res = get_user(block, p); if (res) return res; lock_kernel(); res = mapping->a_ops->bmap(mapping, block); unlock_kernel(); return put_user(res, p); } static int file_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct inode *inode = filp->f_path.dentry->d_inode; int __user *p = (int __user *)arg; switch (cmd) { case FIBMAP: return ioctl_fibmap(filp, p); case FIGETBSZ: return put_user(inode->i_sb->s_blocksize, p); case FIONREAD: return put_user(i_size_read(inode) - filp->f_pos, p); } return vfs_ioctl(filp, cmd, arg); } static int ioctl_fionbio(struct file *filp, int __user *argp) { unsigned int flag; int on, error; error = get_user(on, argp); if (error) return error; flag = O_NONBLOCK; #ifdef __sparc__ /* SunOS compatibility item. */ if (O_NONBLOCK != O_NDELAY) flag |= O_NDELAY; #endif if (on) filp->f_flags |= flag; else filp->f_flags &= ~flag; return error; } static int ioctl_fioasync(unsigned int fd, struct file *filp, int __user *argp) { unsigned int flag; int on, error; error = get_user(on, argp); if (error) return error; flag = on ? FASYNC : 0; /* Did FASYNC state change ? */ if ((flag ^ filp->f_flags) & FASYNC) { if (filp->f_op && filp->f_op->fasync) { lock_kernel(); error = filp->f_op->fasync(fd, filp, on); unlock_kernel(); } else error = -ENOTTY; } if (error) return error; if (on) filp->f_flags |= FASYNC; else filp->f_flags &= ~FASYNC; return error; } /* * When you add any new common ioctls to the switches above and below * please update compat_sys_ioctl() too. * * do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d. * It's just a simple helper for sys_ioctl and compat_sys_ioctl. */ int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd, unsigned long arg) { int error = 0; int __user *argp = (int __user *)arg; switch (cmd) { case FIOCLEX: set_close_on_exec(fd, 1); break; case FIONCLEX: set_close_on_exec(fd, 0); break; case FIONBIO: error = ioctl_fionbio(filp, argp); break; case FIOASYNC: error = ioctl_fioasync(fd, filp, argp); break; case FIOQSIZE: if (S_ISDIR(filp->f_path.dentry->d_inode->i_mode) || S_ISREG(filp->f_path.dentry->d_inode->i_mode) || S_ISLNK(filp->f_path.dentry->d_inode->i_mode)) { loff_t res = inode_get_bytes(filp->f_path.dentry->d_inode); error = copy_to_user((loff_t __user *)arg, &res, sizeof(res)) ? -EFAULT : 0; } else error = -ENOTTY; break; default: if (S_ISREG(filp->f_path.dentry->d_inode->i_mode)) error = file_ioctl(filp, cmd, arg); else error = vfs_ioctl(filp, cmd, arg); break; } return error; } asmlinkage long sys_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg) { struct file *filp; int error = -EBADF; int fput_needed; filp = fget_light(fd, &fput_needed); if (!filp) goto out; error = security_file_ioctl(filp, cmd, arg); if (error) goto out_fput; error = do_vfs_ioctl(filp, fd, cmd, arg); out_fput: fput_light(filp, fput_needed); out: return error; }