c4ec54b40d
introduce a new fsnotify hook, fsnotify_perm(), which is called from the security code. This hook is used to allow fsnotify groups to make access control decisions about events on the system. We also must change the generic fsnotify function to return an error code if we intend these hooks to be in any way useful. Signed-off-by: Eric Paris <eparis@redhat.com>
339 lines
8.3 KiB
C
339 lines
8.3 KiB
C
#ifndef _LINUX_FS_NOTIFY_H
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#define _LINUX_FS_NOTIFY_H
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/*
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* include/linux/fsnotify.h - generic hooks for filesystem notification, to
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* reduce in-source duplication from both dnotify and inotify.
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*
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* We don't compile any of this away in some complicated menagerie of ifdefs.
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* Instead, we rely on the code inside to optimize away as needed.
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*
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* (C) Copyright 2005 Robert Love
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*/
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#include <linux/fsnotify_backend.h>
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#include <linux/audit.h>
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#include <linux/slab.h>
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/*
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* fsnotify_d_instantiate - instantiate a dentry for inode
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* Called with dcache_lock held.
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*/
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static inline void fsnotify_d_instantiate(struct dentry *dentry,
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struct inode *inode)
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{
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__fsnotify_d_instantiate(dentry, inode);
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}
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/* Notify this dentry's parent about a child's events. */
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static inline void fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
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{
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if (!dentry)
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dentry = path->dentry;
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__fsnotify_parent(path, dentry, mask);
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}
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/* simple call site for access decisions */
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static inline int fsnotify_perm(struct file *file, int mask)
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{
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struct path *path = &file->f_path;
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struct inode *inode = path->dentry->d_inode;
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__u32 fsnotify_mask;
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if (file->f_mode & FMODE_NONOTIFY)
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return 0;
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if (!(mask & (MAY_READ | MAY_OPEN)))
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return 0;
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if (mask & MAY_READ)
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fsnotify_mask = FS_ACCESS_PERM;
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if (mask & MAY_OPEN)
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fsnotify_mask = FS_OPEN_PERM;
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return fsnotify(inode, fsnotify_mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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}
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/*
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* fsnotify_d_move - dentry has been moved
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* Called with dcache_lock and dentry->d_lock held.
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*/
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static inline void fsnotify_d_move(struct dentry *dentry)
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{
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/*
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* On move we need to update dentry->d_flags to indicate if the new parent
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* cares about events from this dentry.
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*/
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__fsnotify_update_dcache_flags(dentry);
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}
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/*
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* fsnotify_link_count - inode's link count changed
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*/
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static inline void fsnotify_link_count(struct inode *inode)
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{
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fsnotify(inode, FS_ATTRIB, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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}
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/*
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* fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
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*/
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static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
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const unsigned char *old_name,
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int isdir, struct inode *target, struct dentry *moved)
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{
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struct inode *source = moved->d_inode;
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u32 fs_cookie = fsnotify_get_cookie();
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__u32 old_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_FROM);
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__u32 new_dir_mask = (FS_EVENT_ON_CHILD | FS_MOVED_TO);
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const unsigned char *new_name = moved->d_name.name;
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if (old_dir == new_dir)
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old_dir_mask |= FS_DN_RENAME;
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if (isdir) {
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old_dir_mask |= FS_IN_ISDIR;
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new_dir_mask |= FS_IN_ISDIR;
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}
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fsnotify(old_dir, old_dir_mask, old_dir, FSNOTIFY_EVENT_INODE, old_name, fs_cookie);
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fsnotify(new_dir, new_dir_mask, new_dir, FSNOTIFY_EVENT_INODE, new_name, fs_cookie);
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if (target)
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fsnotify_link_count(target);
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if (source)
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fsnotify(source, FS_MOVE_SELF, moved->d_inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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audit_inode_child(moved, new_dir);
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}
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/*
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* fsnotify_inode_delete - and inode is being evicted from cache, clean up is needed
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*/
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static inline void fsnotify_inode_delete(struct inode *inode)
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{
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__fsnotify_inode_delete(inode);
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}
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/*
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* fsnotify_vfsmount_delete - a vfsmount is being destroyed, clean up is needed
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*/
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static inline void fsnotify_vfsmount_delete(struct vfsmount *mnt)
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{
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__fsnotify_vfsmount_delete(mnt);
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}
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/*
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* fsnotify_nameremove - a filename was removed from a directory
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*/
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static inline void fsnotify_nameremove(struct dentry *dentry, int isdir)
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{
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__u32 mask = FS_DELETE;
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if (isdir)
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mask |= FS_IN_ISDIR;
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fsnotify_parent(NULL, dentry, mask);
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}
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/*
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* fsnotify_inoderemove - an inode is going away
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*/
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static inline void fsnotify_inoderemove(struct inode *inode)
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{
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fsnotify(inode, FS_DELETE_SELF, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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__fsnotify_inode_delete(inode);
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}
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/*
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* fsnotify_create - 'name' was linked in
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*/
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static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
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{
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audit_inode_child(dentry, inode);
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fsnotify(inode, FS_CREATE, dentry->d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
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}
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/*
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* fsnotify_link - new hardlink in 'inode' directory
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* Note: We have to pass also the linked inode ptr as some filesystems leave
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* new_dentry->d_inode NULL and instantiate inode pointer later
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*/
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static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct dentry *new_dentry)
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{
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fsnotify_link_count(inode);
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audit_inode_child(new_dentry, dir);
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fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0);
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}
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/*
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* fsnotify_mkdir - directory 'name' was created
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*/
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static inline void fsnotify_mkdir(struct inode *inode, struct dentry *dentry)
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{
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__u32 mask = (FS_CREATE | FS_IN_ISDIR);
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struct inode *d_inode = dentry->d_inode;
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audit_inode_child(dentry, inode);
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fsnotify(inode, mask, d_inode, FSNOTIFY_EVENT_INODE, dentry->d_name.name, 0);
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}
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/*
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* fsnotify_access - file was read
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*/
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static inline void fsnotify_access(struct file *file)
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{
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struct path *path = &file->f_path;
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struct inode *inode = path->dentry->d_inode;
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__u32 mask = FS_ACCESS;
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if (S_ISDIR(inode->i_mode))
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mask |= FS_IN_ISDIR;
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if (!(file->f_mode & FMODE_NONOTIFY)) {
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fsnotify_parent(path, NULL, mask);
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fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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}
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}
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/*
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* fsnotify_modify - file was modified
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*/
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static inline void fsnotify_modify(struct file *file)
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{
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struct path *path = &file->f_path;
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struct inode *inode = path->dentry->d_inode;
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__u32 mask = FS_MODIFY;
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if (S_ISDIR(inode->i_mode))
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mask |= FS_IN_ISDIR;
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if (!(file->f_mode & FMODE_NONOTIFY)) {
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fsnotify_parent(path, NULL, mask);
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fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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}
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}
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/*
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* fsnotify_open - file was opened
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*/
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static inline void fsnotify_open(struct file *file)
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{
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struct path *path = &file->f_path;
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struct inode *inode = path->dentry->d_inode;
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__u32 mask = FS_OPEN;
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if (S_ISDIR(inode->i_mode))
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mask |= FS_IN_ISDIR;
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if (!(file->f_mode & FMODE_NONOTIFY)) {
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fsnotify_parent(path, NULL, mask);
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fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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}
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}
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/*
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* fsnotify_close - file was closed
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*/
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static inline void fsnotify_close(struct file *file)
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{
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struct path *path = &file->f_path;
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struct inode *inode = file->f_path.dentry->d_inode;
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fmode_t mode = file->f_mode;
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__u32 mask = (mode & FMODE_WRITE) ? FS_CLOSE_WRITE : FS_CLOSE_NOWRITE;
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if (S_ISDIR(inode->i_mode))
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mask |= FS_IN_ISDIR;
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if (!(file->f_mode & FMODE_NONOTIFY)) {
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fsnotify_parent(path, NULL, mask);
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fsnotify(inode, mask, path, FSNOTIFY_EVENT_PATH, NULL, 0);
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}
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}
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/*
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* fsnotify_xattr - extended attributes were changed
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*/
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static inline void fsnotify_xattr(struct dentry *dentry)
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{
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struct inode *inode = dentry->d_inode;
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__u32 mask = FS_ATTRIB;
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if (S_ISDIR(inode->i_mode))
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mask |= FS_IN_ISDIR;
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fsnotify_parent(NULL, dentry, mask);
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fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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}
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/*
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* fsnotify_change - notify_change event. file was modified and/or metadata
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* was changed.
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*/
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static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
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{
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struct inode *inode = dentry->d_inode;
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__u32 mask = 0;
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if (ia_valid & ATTR_UID)
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mask |= FS_ATTRIB;
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if (ia_valid & ATTR_GID)
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mask |= FS_ATTRIB;
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if (ia_valid & ATTR_SIZE)
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mask |= FS_MODIFY;
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/* both times implies a utime(s) call */
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if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
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mask |= FS_ATTRIB;
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else if (ia_valid & ATTR_ATIME)
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mask |= FS_ACCESS;
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else if (ia_valid & ATTR_MTIME)
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mask |= FS_MODIFY;
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if (ia_valid & ATTR_MODE)
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mask |= FS_ATTRIB;
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if (mask) {
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if (S_ISDIR(inode->i_mode))
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mask |= FS_IN_ISDIR;
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fsnotify_parent(NULL, dentry, mask);
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fsnotify(inode, mask, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
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}
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}
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#if defined(CONFIG_FSNOTIFY) /* notify helpers */
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/*
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* fsnotify_oldname_init - save off the old filename before we change it
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*/
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static inline const unsigned char *fsnotify_oldname_init(const unsigned char *name)
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{
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return kstrdup(name, GFP_KERNEL);
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}
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/*
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* fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
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*/
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static inline void fsnotify_oldname_free(const unsigned char *old_name)
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{
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kfree(old_name);
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}
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#else /* CONFIG_FSNOTIFY */
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static inline const char *fsnotify_oldname_init(const unsigned char *name)
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{
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return NULL;
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}
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static inline void fsnotify_oldname_free(const unsigned char *old_name)
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{
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}
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#endif /* CONFIG_FSNOTIFY */
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#endif /* _LINUX_FS_NOTIFY_H */
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