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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-05 17:47:29 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-05 17:47:29 +0000
commit4f5791ebd03eaec1c7da0865a383175b05102712 (patch)
tree8ce7b00f7a76baa386372422adebbe64510812d4 /source4/ntvfs/sysdep/inotify.c
parentInitial commit. (diff)
downloadsamba-4f5791ebd03eaec1c7da0865a383175b05102712.tar.xz
samba-4f5791ebd03eaec1c7da0865a383175b05102712.zip
Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'source4/ntvfs/sysdep/inotify.c')
-rw-r--r--source4/ntvfs/sysdep/inotify.c398
1 files changed, 398 insertions, 0 deletions
diff --git a/source4/ntvfs/sysdep/inotify.c b/source4/ntvfs/sysdep/inotify.c
new file mode 100644
index 0000000..ba4b336
--- /dev/null
+++ b/source4/ntvfs/sysdep/inotify.c
@@ -0,0 +1,398 @@
+/*
+ Unix SMB/CIFS implementation.
+
+ Copyright (C) Andrew Tridgell 2006
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+ notify implementation using inotify
+*/
+
+#include "includes.h"
+#include "system/filesys.h"
+#include <tevent.h>
+#include "ntvfs/sysdep/sys_notify.h"
+#include "../lib/util/dlinklist.h"
+#include "libcli/raw/smb.h"
+#include "param/param.h"
+
+#include <sys/inotify.h>
+
+/* glibc < 2.5 headers don't have these defines */
+#ifndef IN_ONLYDIR
+#define IN_ONLYDIR 0x01000000
+#endif
+#ifndef IN_MASK_ADD
+#define IN_MASK_ADD 0x20000000
+#endif
+
+struct inotify_private {
+ struct sys_notify_context *ctx;
+ int fd;
+ struct inotify_watch_context *watches;
+};
+
+struct inotify_watch_context {
+ struct inotify_watch_context *next, *prev;
+ struct inotify_private *in;
+ int wd;
+ sys_notify_callback_t callback;
+ void *private_data;
+ uint32_t mask; /* the inotify mask */
+ uint32_t filter; /* the windows completion filter */
+ const char *path;
+};
+
+
+/*
+ see if a particular event from inotify really does match a requested
+ notify event in SMB
+*/
+static bool filter_match(struct inotify_watch_context *w,
+ struct inotify_event *e)
+{
+ if ((e->mask & w->mask) == 0) {
+ /* this happens because inotify_add_watch() coalesces watches on the same
+ path, oring their masks together */
+ return false;
+ }
+
+ /* SMB separates the filters for files and directories */
+ if (e->mask & IN_ISDIR) {
+ if ((w->filter & FILE_NOTIFY_CHANGE_DIR_NAME) == 0) {
+ return false;
+ }
+ } else {
+ if ((e->mask & IN_ATTRIB) &&
+ (w->filter & (FILE_NOTIFY_CHANGE_ATTRIBUTES|
+ FILE_NOTIFY_CHANGE_LAST_WRITE|
+ FILE_NOTIFY_CHANGE_LAST_ACCESS|
+ FILE_NOTIFY_CHANGE_EA|
+ FILE_NOTIFY_CHANGE_SECURITY))) {
+ return true;
+ }
+ if ((e->mask & IN_MODIFY) &&
+ (w->filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)) {
+ return true;
+ }
+ if ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) == 0) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+
+
+/*
+ dispatch one inotify event
+
+ the cookies are used to correctly handle renames
+*/
+static void inotify_dispatch(struct inotify_private *in,
+ struct inotify_event *e,
+ uint32_t prev_cookie,
+ struct inotify_event *e2)
+{
+ struct inotify_watch_context *w, *next;
+ struct notify_event ne;
+
+ /* ignore extraneous events, such as unmount and IN_IGNORED events */
+ if ((e->mask & (IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE|
+ IN_MOVED_FROM|IN_MOVED_TO)) == 0) {
+ return;
+ }
+
+ /* map the inotify mask to a action. This gets complicated for
+ renames */
+ if (e->mask & IN_CREATE) {
+ ne.action = NOTIFY_ACTION_ADDED;
+ } else if (e->mask & IN_DELETE) {
+ ne.action = NOTIFY_ACTION_REMOVED;
+ } else if (e->mask & IN_MOVED_FROM) {
+ if (e2 != NULL && e2->cookie == e->cookie) {
+ ne.action = NOTIFY_ACTION_OLD_NAME;
+ } else {
+ ne.action = NOTIFY_ACTION_REMOVED;
+ }
+ } else if (e->mask & IN_MOVED_TO) {
+ if (e->cookie == prev_cookie) {
+ ne.action = NOTIFY_ACTION_NEW_NAME;
+ } else {
+ ne.action = NOTIFY_ACTION_ADDED;
+ }
+ } else {
+ ne.action = NOTIFY_ACTION_MODIFIED;
+ }
+ ne.path = e->name;
+
+ /* find any watches that have this watch descriptor */
+ for (w=in->watches;w;w=next) {
+ next = w->next;
+ if (w->wd == e->wd && filter_match(w, e)) {
+ ne.dir = w->path;
+ w->callback(in->ctx, w->private_data, &ne);
+ }
+ }
+
+ /* SMB expects a file rename to generate three events, two for
+ the rename and the other for a modify of the
+ destination. Strange! */
+ if (ne.action != NOTIFY_ACTION_NEW_NAME ||
+ (e->mask & IN_ISDIR) != 0) {
+ return;
+ }
+
+ ne.action = NOTIFY_ACTION_MODIFIED;
+ e->mask = IN_ATTRIB;
+
+ for (w=in->watches;w;w=next) {
+ next = w->next;
+ if (w->wd == e->wd && filter_match(w, e) &&
+ !(w->filter & FILE_NOTIFY_CHANGE_CREATION)) {
+ ne.dir = w->path;
+ w->callback(in->ctx, w->private_data, &ne);
+ }
+ }
+}
+
+/*
+ called when the kernel has some events for us
+*/
+static void inotify_handler(struct tevent_context *ev, struct tevent_fd *fde,
+ uint16_t flags, void *private_data)
+{
+ struct inotify_private *in = talloc_get_type(private_data,
+ struct inotify_private);
+ int bufsize = 0;
+ struct inotify_event *e0, *e;
+ uint32_t prev_cookie=0;
+
+ /*
+ we must use FIONREAD as we cannot predict the length of the
+ filenames, and thus can't know how much to allocate
+ otherwise
+ */
+ if (ioctl(in->fd, FIONREAD, &bufsize) != 0 ||
+ bufsize == 0) {
+ DEBUG(0,("No data on inotify fd?!\n"));
+ return;
+ }
+
+ e0 = e = talloc_size(in, bufsize);
+ if (e == NULL) return;
+
+ if (read(in->fd, e0, bufsize) != bufsize) {
+ DEBUG(0,("Failed to read all inotify data\n"));
+ talloc_free(e0);
+ return;
+ }
+
+ /* we can get more than one event in the buffer */
+ while (bufsize >= sizeof(*e)) {
+ struct inotify_event *e2 = NULL;
+ bufsize -= e->len + sizeof(*e);
+ if (bufsize >= sizeof(*e)) {
+ e2 = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e);
+ }
+ inotify_dispatch(in, e, prev_cookie, e2);
+ prev_cookie = e->cookie;
+ e = e2;
+ }
+
+ talloc_free(e0);
+}
+
+/*
+ setup the inotify handle - called the first time a watch is added on
+ this context
+*/
+static NTSTATUS inotify_setup(struct sys_notify_context *ctx)
+{
+ struct inotify_private *in;
+ struct tevent_fd *fde;
+
+ in = talloc(ctx, struct inotify_private);
+ NT_STATUS_HAVE_NO_MEMORY(in);
+
+ in->fd = inotify_init();
+ if (in->fd == -1) {
+ DEBUG(0,("Failed to init inotify - %s\n", strerror(errno)));
+ talloc_free(in);
+ return map_nt_error_from_unix_common(errno);
+ }
+ in->ctx = ctx;
+ in->watches = NULL;
+
+ ctx->private_data = in;
+
+ /* add a event waiting for the inotify fd to be readable */
+ fde = tevent_add_fd(ctx->ev, in, in->fd,
+ TEVENT_FD_READ, inotify_handler, in);
+ if (!fde) {
+ if (errno == 0) {
+ errno = ENOMEM;
+ }
+ DEBUG(0,("Failed to tevent_add_fd() - %s\n", strerror(errno)));
+ talloc_free(in);
+ return map_nt_error_from_unix_common(errno);
+ }
+
+ tevent_fd_set_auto_close(fde);
+
+ return NT_STATUS_OK;
+}
+
+
+/*
+ map from a change notify mask to a inotify mask. Remove any bits
+ which we can handle
+*/
+static const struct {
+ uint32_t notify_mask;
+ uint32_t inotify_mask;
+} inotify_mapping[] = {
+ {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
+ {FILE_NOTIFY_CHANGE_DIR_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
+ {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY},
+ {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB},
+ {FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB},
+ {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB},
+ {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB}
+};
+
+static uint32_t inotify_map(struct notify_entry *e)
+{
+ int i;
+ uint32_t out=0;
+ for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
+ if (inotify_mapping[i].notify_mask & e->filter) {
+ out |= inotify_mapping[i].inotify_mask;
+ e->filter &= ~inotify_mapping[i].notify_mask;
+ }
+ }
+ return out;
+}
+
+/*
+ destroy a watch
+*/
+static int watch_destructor(struct inotify_watch_context *w)
+{
+ struct inotify_private *in = w->in;
+ int wd = w->wd;
+ DLIST_REMOVE(w->in->watches, w);
+
+ /* only rm the watch if its the last one with this wd */
+ for (w=in->watches;w;w=w->next) {
+ if (w->wd == wd) break;
+ }
+ if (w == NULL) {
+ inotify_rm_watch(in->fd, wd);
+ }
+ return 0;
+}
+
+
+/*
+ add a watch. The watch is removed when the caller calls
+ talloc_free() on *handle
+*/
+static NTSTATUS inotify_watch(struct sys_notify_context *ctx,
+ struct notify_entry *e,
+ sys_notify_callback_t callback,
+ void *private_data,
+ void *handle_p)
+{
+ struct inotify_private *in;
+ int wd;
+ uint32_t mask;
+ struct inotify_watch_context *w;
+ uint32_t filter = e->filter;
+ void **handle = (void **)handle_p;
+
+ /* maybe setup the inotify fd */
+ if (ctx->private_data == NULL) {
+ NTSTATUS status;
+ status = inotify_setup(ctx);
+ NT_STATUS_NOT_OK_RETURN(status);
+ }
+
+ in = talloc_get_type(ctx->private_data, struct inotify_private);
+
+ mask = inotify_map(e);
+ if (mask == 0) {
+ /* this filter can't be handled by inotify */
+ return NT_STATUS_INVALID_PARAMETER;
+ }
+
+ /* using IN_MASK_ADD allows us to cope with inotify() returning the same
+ watch descriptor for muliple watches on the same path */
+ mask |= (IN_MASK_ADD | IN_ONLYDIR);
+
+ /* get a new watch descriptor for this path */
+ wd = inotify_add_watch(in->fd, e->path, mask);
+ if (wd == -1) {
+ e->filter = filter;
+ return map_nt_error_from_unix_common(errno);
+ }
+
+ w = talloc(in, struct inotify_watch_context);
+ if (w == NULL) {
+ inotify_rm_watch(in->fd, wd);
+ e->filter = filter;
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ w->in = in;
+ w->wd = wd;
+ w->callback = callback;
+ w->private_data = private_data;
+ w->mask = mask;
+ w->filter = filter;
+ w->path = talloc_strdup(w, e->path);
+ if (w->path == NULL) {
+ inotify_rm_watch(in->fd, wd);
+ e->filter = filter;
+ return NT_STATUS_NO_MEMORY;
+ }
+
+ (*handle) = w;
+
+ DLIST_ADD(in->watches, w);
+
+ /* the caller frees the handle to stop watching */
+ talloc_set_destructor(w, watch_destructor);
+
+ return NT_STATUS_OK;
+}
+
+
+static struct sys_notify_backend inotify = {
+ .name = "inotify",
+ .notify_watch = inotify_watch
+};
+
+/*
+ initialialise the inotify module
+ */
+NTSTATUS sys_notify_inotify_init(TALLOC_CTX *);
+NTSTATUS sys_notify_inotify_init(TALLOC_CTX *ctx)
+{
+ /* register ourselves as a system inotify module */
+ return sys_notify_register(ctx, &inotify);
+}