/* * linux/fs/readdir.c * * Copyright (C) 1995 Linus Torvalds */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/time.h> #include <linux/mm.h> #include <linux/errno.h> #include <linux/stat.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/dirent.h> #include <linux/security.h> #include <linux/syscalls.h> #include <linux/unistd.h> #include <asm/uaccess.h> int vfs_readdir(struct file *file, filldir_t filler, void *buf) { struct inode *inode = file->f_path.dentry->d_inode; int res = -ENOTDIR; if (!file->f_op || !file->f_op->readdir) goto out; res = security_file_permission(file, MAY_READ); if (res) goto out; res = mutex_lock_killable(&inode->i_mutex); if (res) goto out; res = -ENOENT; if (!IS_DEADDIR(inode)) { res = file->f_op->readdir(file, buf, filler); file_accessed(file); } mutex_unlock(&inode->i_mutex); out: return res; } EXPORT_SYMBOL(vfs_readdir); /* * Traditional linux readdir() handling.. * * "count=1" is a special case, meaning that the buffer is one * dirent-structure in size and that the code can't handle more * anyway. Thus the special "fillonedir()" function for that * case (the low-level handlers don't need to care about this). */ #define NAME_OFFSET(de) ((int) ((de)->d_name - (char __user *) (de))) #ifdef __ARCH_WANT_OLD_READDIR struct old_linux_dirent { unsigned long d_ino; unsigned long d_offset; unsigned short d_namlen; char d_name[1]; }; struct readdir_callback { struct old_linux_dirent __user * dirent; int result; }; static int fillonedir(void * __buf, const char * name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct readdir_callback * buf = (struct readdir_callback *) __buf; struct old_linux_dirent __user * dirent; unsigned long d_ino; if (buf->result) return -EINVAL; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) return -EOVERFLOW; buf->result++; dirent = buf->dirent; if (!access_ok(VERIFY_WRITE, dirent, (unsigned long)(dirent->d_name + namlen + 1) - (unsigned long)dirent)) goto efault; if ( __put_user(d_ino, &dirent->d_ino) || __put_user(offset, &dirent->d_offset) || __put_user(namlen, &dirent->d_namlen) || __copy_to_user(dirent->d_name, name, namlen) || __put_user(0, dirent->d_name + namlen)) goto efault; return 0; efault: buf->result = -EFAULT; return -EFAULT; } asmlinkage long old_readdir(unsigned int fd, struct old_linux_dirent __user * dirent, unsigned int count) { int error; struct file * file; struct readdir_callback buf; error = -EBADF; file = fget(fd); if (!file) goto out; buf.result = 0; buf.dirent = dirent; error = vfs_readdir(file, fillonedir, &buf); if (error >= 0) error = buf.result; fput(file); out: return error; } #endif /* __ARCH_WANT_OLD_READDIR */ /* * New, all-improved, singing, dancing, iBCS2-compliant getdents() * interface. */ struct linux_dirent { unsigned long d_ino; unsigned long d_off; unsigned short d_reclen; char d_name[1]; }; struct getdents_callback { struct linux_dirent __user * current_dir; struct linux_dirent __user * previous; int count; int error; }; static int filldir(void * __buf, const char * name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct linux_dirent __user * dirent; struct getdents_callback * buf = (struct getdents_callback *) __buf; unsigned long d_ino; int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 2, sizeof(long)); buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) return -EINVAL; d_ino = ino; if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) return -EOVERFLOW; dirent = buf->previous; if (dirent) { if (__put_user(offset, &dirent->d_off)) goto efault; } dirent = buf->current_dir; if (__put_user(d_ino, &dirent->d_ino)) goto efault; if (__put_user(reclen, &dirent->d_reclen)) goto efault; if (copy_to_user(dirent->d_name, name, namlen)) goto efault; if (__put_user(0, dirent->d_name + namlen)) goto efault; if (__put_user(d_type, (char __user *) dirent + reclen - 1)) goto efault; buf->previous = dirent; dirent = (void __user *)dirent + reclen; buf->current_dir = dirent; buf->count -= reclen; return 0; efault: buf->error = -EFAULT; return -EFAULT; } asmlinkage long sys_getdents(unsigned int fd, struct linux_dirent __user * dirent, unsigned int count) { struct file * file; struct linux_dirent __user * lastdirent; struct getdents_callback buf; int error; error = -EFAULT; if (!access_ok(VERIFY_WRITE, dirent, count)) goto out; error = -EBADF; file = fget(fd); if (!file) goto out; buf.current_dir = dirent; buf.previous = NULL; buf.count = count; buf.error = 0; error = vfs_readdir(file, filldir, &buf); if (error < 0) goto out_putf; error = buf.error; lastdirent = buf.previous; if (lastdirent) { if (put_user(file->f_pos, &lastdirent->d_off)) error = -EFAULT; else error = count - buf.count; } out_putf: fput(file); out: return error; } struct getdents_callback64 { struct linux_dirent64 __user * current_dir; struct linux_dirent64 __user * previous; int count; int error; }; static int filldir64(void * __buf, const char * name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct linux_dirent64 __user *dirent; struct getdents_callback64 * buf = (struct getdents_callback64 *) __buf; int reclen = ALIGN(NAME_OFFSET(dirent) + namlen + 1, sizeof(u64)); buf->error = -EINVAL; /* only used if we fail.. */ if (reclen > buf->count) return -EINVAL; dirent = buf->previous; if (dirent) { if (__put_user(offset, &dirent->d_off)) goto efault; } dirent = buf->current_dir; if (__put_user(ino, &dirent->d_ino)) goto efault; if (__put_user(0, &dirent->d_off)) goto efault; if (__put_user(reclen, &dirent->d_reclen)) goto efault; if (__put_user(d_type, &dirent->d_type)) goto efault; if (copy_to_user(dirent->d_name, name, namlen)) goto efault; if (__put_user(0, dirent->d_name + namlen)) goto efault; buf->previous = dirent; dirent = (void __user *)dirent + reclen; buf->current_dir = dirent; buf->count -= reclen; return 0; efault: buf->error = -EFAULT; return -EFAULT; } asmlinkage long sys_getdents64(unsigned int fd, struct linux_dirent64 __user * dirent, unsigned int count) { struct file * file; struct linux_dirent64 __user * lastdirent; struct getdents_callback64 buf; int error; error = -EFAULT; if (!access_ok(VERIFY_WRITE, dirent, count)) goto out; error = -EBADF; file = fget(fd); if (!file) goto out; buf.current_dir = dirent; buf.previous = NULL; buf.count = count; buf.error = 0; error = vfs_readdir(file, filldir64, &buf); if (error < 0) goto out_putf; error = buf.error; lastdirent = buf.previous; if (lastdirent) { typeof(lastdirent->d_off) d_off = file->f_pos; error = -EFAULT; if (__put_user(d_off, &lastdirent->d_off)) goto out_putf; error = count - buf.count; } out_putf: fput(file); out: return error; }