linux/fs/notify/fanotify/fanotify_user.c

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#include <linux/fcntl.h>
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/anon_inodes.h>
#include <linux/fsnotify_backend.h>
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
#include <linux/init.h>
#include <linux/mount.h>
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
#include <linux/namei.h>
#include <linux/poll.h>
#include <linux/security.h>
#include <linux/syscalls.h>
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
#include <linux/types.h>
#include <linux/uaccess.h>
#include <asm/ioctls.h>
#include "fanotify.h"
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
static struct kmem_cache *fanotify_mark_cache __read_mostly;
/*
* Get an fsnotify notification event if one exists and is small
* enough to fit in "count". Return an error pointer if the count
* is not large enough.
*
* Called with the group->notification_mutex held.
*/
static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
size_t count)
{
BUG_ON(!mutex_is_locked(&group->notification_mutex));
pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
if (fsnotify_notify_queue_is_empty(group))
return NULL;
if (FAN_EVENT_METADATA_LEN > count)
return ERR_PTR(-EINVAL);
/* held the notification_mutex the whole time, so this is the
* same event we peeked above */
return fsnotify_remove_notify_event(group);
}
static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event)
{
int client_fd;
struct dentry *dentry;
struct vfsmount *mnt;
struct file *new_file;
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
client_fd = get_unused_fd();
if (client_fd < 0)
return client_fd;
if (event->data_type != FSNOTIFY_EVENT_PATH) {
WARN_ON(1);
put_unused_fd(client_fd);
return -EINVAL;
}
/*
* we need a new file handle for the userspace program so it can read even if it was
* originally opened O_WRONLY.
*/
dentry = dget(event->path.dentry);
mnt = mntget(event->path.mnt);
/* it's possible this event was an overflow event. in that case dentry and mnt
* are NULL; That's fine, just don't call dentry open */
if (dentry && mnt)
new_file = dentry_open(dentry, mnt,
O_RDONLY | O_LARGEFILE | FMODE_NONOTIFY,
current_cred());
else
new_file = ERR_PTR(-EOVERFLOW);
if (IS_ERR(new_file)) {
/*
* we still send an event even if we can't open the file. this
* can happen when say tasks are gone and we try to open their
* /proc files or we try to open a WRONLY file like in sysfs
* we just send the errno to userspace since there isn't much
* else we can do.
*/
put_unused_fd(client_fd);
client_fd = PTR_ERR(new_file);
} else {
fd_install(client_fd, new_file);
}
return client_fd;
}
static ssize_t fill_event_metadata(struct fsnotify_group *group,
struct fanotify_event_metadata *metadata,
struct fsnotify_event *event)
{
pr_debug("%s: group=%p metadata=%p event=%p\n", __func__,
group, metadata, event);
metadata->event_len = FAN_EVENT_METADATA_LEN;
metadata->vers = FANOTIFY_METADATA_VERSION;
metadata->mask = fanotify_outgoing_mask(event->mask);
metadata->pid = pid_vnr(event->tgid);
metadata->fd = create_fd(group, event);
return metadata->fd;
}
static ssize_t copy_event_to_user(struct fsnotify_group *group,
struct fsnotify_event *event,
char __user *buf)
{
struct fanotify_event_metadata fanotify_event_metadata;
int ret;
pr_debug("%s: group=%p event=%p\n", __func__, group, event);
ret = fill_event_metadata(group, &fanotify_event_metadata, event);
if (ret < 0)
return ret;
if (copy_to_user(buf, &fanotify_event_metadata, FAN_EVENT_METADATA_LEN))
return -EFAULT;
return FAN_EVENT_METADATA_LEN;
}
/* intofiy userspace file descriptor functions */
static unsigned int fanotify_poll(struct file *file, poll_table *wait)
{
struct fsnotify_group *group = file->private_data;
int ret = 0;
poll_wait(file, &group->notification_waitq, wait);
mutex_lock(&group->notification_mutex);
if (!fsnotify_notify_queue_is_empty(group))
ret = POLLIN | POLLRDNORM;
mutex_unlock(&group->notification_mutex);
return ret;
}
static ssize_t fanotify_read(struct file *file, char __user *buf,
size_t count, loff_t *pos)
{
struct fsnotify_group *group;
struct fsnotify_event *kevent;
char __user *start;
int ret;
DEFINE_WAIT(wait);
start = buf;
group = file->private_data;
pr_debug("%s: group=%p\n", __func__, group);
while (1) {
prepare_to_wait(&group->notification_waitq, &wait, TASK_INTERRUPTIBLE);
mutex_lock(&group->notification_mutex);
kevent = get_one_event(group, count);
mutex_unlock(&group->notification_mutex);
if (kevent) {
ret = PTR_ERR(kevent);
if (IS_ERR(kevent))
break;
ret = copy_event_to_user(group, kevent, buf);
fsnotify_put_event(kevent);
if (ret < 0)
break;
buf += ret;
count -= ret;
continue;
}
ret = -EAGAIN;
if (file->f_flags & O_NONBLOCK)
break;
ret = -EINTR;
if (signal_pending(current))
break;
if (start != buf)
break;
schedule();
}
finish_wait(&group->notification_waitq, &wait);
if (start != buf && ret != -EFAULT)
ret = buf - start;
return ret;
}
static int fanotify_release(struct inode *ignored, struct file *file)
{
struct fsnotify_group *group = file->private_data;
pr_debug("%s: file=%p group=%p\n", __func__, file, group);
/* matches the fanotify_init->fsnotify_alloc_group */
fsnotify_put_group(group);
return 0;
}
static long fanotify_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct fsnotify_group *group;
struct fsnotify_event_holder *holder;
void __user *p;
int ret = -ENOTTY;
size_t send_len = 0;
group = file->private_data;
p = (void __user *) arg;
switch (cmd) {
case FIONREAD:
mutex_lock(&group->notification_mutex);
list_for_each_entry(holder, &group->notification_list, event_list)
send_len += FAN_EVENT_METADATA_LEN;
mutex_unlock(&group->notification_mutex);
ret = put_user(send_len, (int __user *) p);
break;
}
return ret;
}
static const struct file_operations fanotify_fops = {
.poll = fanotify_poll,
.read = fanotify_read,
.fasync = NULL,
.release = fanotify_release,
.unlocked_ioctl = fanotify_ioctl,
.compat_ioctl = fanotify_ioctl,
};
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
static void fanotify_free_mark(struct fsnotify_mark *fsn_mark)
{
kmem_cache_free(fanotify_mark_cache, fsn_mark);
}
static int fanotify_find_path(int dfd, const char __user *filename,
struct path *path, unsigned int flags)
{
int ret;
pr_debug("%s: dfd=%d filename=%p flags=%x\n", __func__,
dfd, filename, flags);
if (filename == NULL) {
struct file *file;
int fput_needed;
ret = -EBADF;
file = fget_light(dfd, &fput_needed);
if (!file)
goto out;
ret = -ENOTDIR;
if ((flags & FAN_MARK_ONLYDIR) &&
!(S_ISDIR(file->f_path.dentry->d_inode->i_mode))) {
fput_light(file, fput_needed);
goto out;
}
*path = file->f_path;
path_get(path);
fput_light(file, fput_needed);
} else {
unsigned int lookup_flags = 0;
if (!(flags & FAN_MARK_DONT_FOLLOW))
lookup_flags |= LOOKUP_FOLLOW;
if (flags & FAN_MARK_ONLYDIR)
lookup_flags |= LOOKUP_DIRECTORY;
ret = user_path_at(dfd, filename, lookup_flags, path);
if (ret)
goto out;
}
/* you can only watch an inode if you have read permissions on it */
ret = inode_permission(path->dentry->d_inode, MAY_READ);
if (ret)
path_put(path);
out:
return ret;
}
static int fanotify_remove_mark(struct fsnotify_group *group,
struct inode *inode,
__u32 mask)
{
struct fsnotify_mark *fsn_mark;
__u32 new_mask;
pr_debug("%s: group=%p inode=%p mask=%x\n", __func__,
group, inode, mask);
fsn_mark = fsnotify_find_inode_mark(group, inode);
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
if (!fsn_mark)
return -ENOENT;
spin_lock(&fsn_mark->lock);
fsn_mark->mask &= ~mask;
new_mask = fsn_mark->mask;
spin_unlock(&fsn_mark->lock);
if (!new_mask)
fsnotify_destroy_mark(fsn_mark);
else
fsnotify_recalc_inode_mask(inode);
fsnotify_recalc_group_mask(group);
/* matches the fsnotify_find_inode_mark() */
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
fsnotify_put_mark(fsn_mark);
return 0;
}
static int fanotify_add_mark(struct fsnotify_group *group,
struct inode *inode,
__u32 mask)
{
struct fsnotify_mark *fsn_mark;
__u32 old_mask, new_mask;
int ret;
pr_debug("%s: group=%p inode=%p mask=%x\n", __func__,
group, inode, mask);
fsn_mark = fsnotify_find_inode_mark(group, inode);
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
if (!fsn_mark) {
struct fsnotify_mark *new_fsn_mark;
ret = -ENOMEM;
new_fsn_mark = kmem_cache_alloc(fanotify_mark_cache, GFP_KERNEL);
if (!new_fsn_mark)
goto out;
fsnotify_init_mark(new_fsn_mark, fanotify_free_mark);
ret = fsnotify_add_mark(new_fsn_mark, group, inode, NULL, 0);
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
if (ret) {
fanotify_free_mark(new_fsn_mark);
goto out;
}
fsn_mark = new_fsn_mark;
}
ret = 0;
spin_lock(&fsn_mark->lock);
old_mask = fsn_mark->mask;
fsn_mark->mask |= mask;
new_mask = fsn_mark->mask;
spin_unlock(&fsn_mark->lock);
/* we made changes to a mask, update the group mask and the inode mask
* so things happen quickly. */
if (old_mask != new_mask) {
/* more bits in old than in new? */
int dropped = (old_mask & ~new_mask);
/* more bits in this mark than the inode's mask? */
int do_inode = (new_mask & ~inode->i_fsnotify_mask);
/* more bits in this mark than the group? */
int do_group = (new_mask & ~group->mask);
/* update the inode with this new mark */
if (dropped || do_inode)
fsnotify_recalc_inode_mask(inode);
/* update the group mask with the new mask */
if (dropped || do_group)
fsnotify_recalc_group_mask(group);
}
/* match the init or the find.... */
fsnotify_put_mark(fsn_mark);
out:
return ret;
}
static int fanotify_update_mark(struct fsnotify_group *group,
struct inode *inode, int flags,
__u32 mask)
{
pr_debug("%s: group=%p inode=%p flags=%x mask=%x\n", __func__,
group, inode, flags, mask);
if (flags & FAN_MARK_ADD)
fanotify_add_mark(group, inode, mask);
else if (flags & FAN_MARK_REMOVE)
fanotify_remove_mark(group, inode, mask);
else
BUG();
return 0;
}
static bool fanotify_mark_validate_input(int flags,
__u32 mask)
{
pr_debug("%s: flags=%x mask=%x\n", __func__, flags, mask);
/* are flags valid of this operation? */
if (!fanotify_mark_flags_valid(flags))
return false;
/* is the mask valid? */
if (!fanotify_mask_valid(mask))
return false;
return true;
}
/* fanotify syscalls */
SYSCALL_DEFINE3(fanotify_init, unsigned int, flags, unsigned int, event_f_flags,
unsigned int, priority)
{
struct fsnotify_group *group;
int f_flags, fd;
pr_debug("%s: flags=%d event_f_flags=%d priority=%d\n",
__func__, flags, event_f_flags, priority);
if (event_f_flags)
return -EINVAL;
if (priority)
return -EINVAL;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
if (flags & ~FAN_ALL_INIT_FLAGS)
return -EINVAL;
f_flags = (O_RDONLY | FMODE_NONOTIFY);
if (flags & FAN_CLOEXEC)
f_flags |= O_CLOEXEC;
if (flags & FAN_NONBLOCK)
f_flags |= O_NONBLOCK;
/* fsnotify_alloc_group takes a ref. Dropped in fanotify_release */
group = fsnotify_alloc_group(&fanotify_fsnotify_ops);
if (IS_ERR(group))
return PTR_ERR(group);
fd = anon_inode_getfd("[fanotify]", &fanotify_fops, group, f_flags);
if (fd < 0)
goto out_put_group;
return fd;
out_put_group:
fsnotify_put_group(group);
return fd;
}
SYSCALL_DEFINE(fanotify_mark)(int fanotify_fd, unsigned int flags,
__u64 mask, int dfd,
const char __user * pathname)
{
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
struct inode *inode;
struct fsnotify_group *group;
struct file *filp;
struct path path;
int ret, fput_needed;
pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n",
__func__, fanotify_fd, flags, dfd, pathname, mask);
/* we only use the lower 32 bits as of right now. */
if (mask & ((__u64)0xffffffff << 32))
return -EINVAL;
if (!fanotify_mark_validate_input(flags, mask))
return -EINVAL;
filp = fget_light(fanotify_fd, &fput_needed);
if (unlikely(!filp))
return -EBADF;
/* verify that this is indeed an fanotify instance */
ret = -EINVAL;
if (unlikely(filp->f_op != &fanotify_fops))
goto fput_and_out;
ret = fanotify_find_path(dfd, pathname, &path, flags);
if (ret)
goto fput_and_out;
/* inode held in place by reference to path; group by fget on fd */
inode = path.dentry->d_inode;
group = filp->private_data;
/* create/update an inode mark */
ret = fanotify_update_mark(group, inode, flags, mask);
path_put(&path);
fput_and_out:
fput_light(filp, fput_needed);
return ret;
}
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
asmlinkage long SyS_fanotify_mark(long fanotify_fd, long flags, __u64 mask,
long dfd, long pathname)
{
return SYSC_fanotify_mark((int) fanotify_fd, (unsigned int) flags,
mask, (int) dfd,
(const char __user *) pathname);
}
SYSCALL_ALIAS(sys_fanotify_mark, SyS_fanotify_mark);
#endif
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
/*
* fanotify_user_setup - Our initialization function. Note that we cannnot return
* error because we have compiled-in VFS hooks. So an (unlikely) failure here
* must result in panic().
*/
static int __init fanotify_user_setup(void)
{
fanotify_mark_cache = KMEM_CACHE(fsnotify_mark, SLAB_PANIC);
return 0;
}
fanotify: fanotify_mark syscall implementation NAME fanotify_mark - add, remove, or modify an fanotify mark on a filesystem object SYNOPSIS int fanotify_mark(int fanotify_fd, unsigned int flags, u64 mask, int dfd, const char *pathname) DESCRIPTION fanotify_mark() is used to add remove or modify a mark on a filesystem object. Marks are used to indicate that the fanotify group is interested in events which occur on that object. At this point in time marks may only be added to files and directories. fanotify_fd must be a file descriptor returned by fanotify_init() The flags field must contain exactly one of the following: FAN_MARK_ADD - or the bits in mask and ignored mask into the mark FAN_MARK_REMOVE - bitwise remove the bits in mask and ignored mark from the mark The following values can be OR'd into the flags field: FAN_MARK_DONT_FOLLOW - same meaning as O_NOFOLLOW as described in open(2) FAN_MARK_ONLYDIR - same meaning as O_DIRECTORY as described in open(2) dfd may be any of the following: AT_FDCWD: the object will be lookup up based on pathname similar to open(2) file descriptor of a directory: if pathname is not NULL the object to modify will be lookup up similar to openat(2) file descriptor of the final object: if pathname is NULL the object to modify will be the object referenced by dfd The mask is the bitwise OR of the set of events of interest such as: FAN_ACCESS - object was accessed (read) FAN_MODIFY - object was modified (write) FAN_CLOSE_WRITE - object was writable and was closed FAN_CLOSE_NOWRITE - object was read only and was closed FAN_OPEN - object was opened FAN_EVENT_ON_CHILD - interested in objected that happen to children. Only relavent when the object is a directory FAN_Q_OVERFLOW - event queue overflowed (not implemented) RETURN VALUE On success, this system call returns 0. On error, -1 is returned, and errno is set to indicate the error. ERRORS EINVAL An invalid value was specified in flags. EINVAL An invalid value was specified in mask. EINVAL An invalid value was specified in ignored_mask. EINVAL fanotify_fd is not a file descriptor as returned by fanotify_init() EBADF fanotify_fd is not a valid file descriptor EBADF dfd is not a valid file descriptor and path is NULL. ENOTDIR dfd is not a directory and path is not NULL EACCESS no search permissions on some part of the path ENENT file not found ENOMEM Insufficient kernel memory is available. CONFORMING TO These system calls are Linux-specific. Signed-off-by: Eric Paris <eparis@redhat.com>
2009-12-18 02:24:26 +00:00
device_initcall(fanotify_user_setup);