2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 2006
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 notify implementation using inotify
25 #include "../librpc/gen_ndr/notify.h"
26 #include "smbd/smbd.h"
27 #include "lib/sys_rw_data.h"
31 #include <sys/inotify.h>
33 /* glibc < 2.5 headers don't have these defines */
35 #define IN_ONLYDIR 0x01000000
38 #define IN_MASK_ADD 0x20000000
41 struct inotify_private {
42 struct sys_notify_context *ctx;
44 struct inotify_watch_context *watches;
47 struct inotify_watch_context {
48 struct inotify_watch_context *next, *prev;
49 struct inotify_private *in;
51 void (*callback)(struct sys_notify_context *ctx,
53 struct notify_event *ev);
55 uint32_t mask; /* the inotify mask */
56 uint32_t filter; /* the windows completion filter */
62 destroy the inotify private context
64 static int inotify_destructor(struct inotify_private *in)
72 see if a particular event from inotify really does match a requested
75 static bool filter_match(struct inotify_watch_context *w,
76 struct inotify_event *e)
78 DEBUG(10, ("filter_match: e->mask=%x, w->mask=%x, w->filter=%x\n",
79 e->mask, w->mask, w->filter));
81 if ((e->mask & w->mask) == 0) {
82 /* this happens because inotify_add_watch() coalesces watches on the same
83 path, oring their masks together */
87 /* SMB separates the filters for files and directories */
88 if (e->mask & IN_ISDIR) {
89 if ((w->filter & FILE_NOTIFY_CHANGE_DIR_NAME) == 0) {
93 if ((e->mask & IN_ATTRIB) &&
94 (w->filter & (FILE_NOTIFY_CHANGE_ATTRIBUTES|
95 FILE_NOTIFY_CHANGE_LAST_WRITE|
96 FILE_NOTIFY_CHANGE_LAST_ACCESS|
97 FILE_NOTIFY_CHANGE_EA|
98 FILE_NOTIFY_CHANGE_SECURITY))) {
101 if ((e->mask & IN_MODIFY) &&
102 (w->filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)) {
105 if ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) == 0) {
116 dispatch one inotify event
118 the cookies are used to correctly handle renames
120 static void inotify_dispatch(struct inotify_private *in,
121 struct inotify_event *e,
123 uint32_t prev_cookie,
124 struct inotify_event *e2)
126 struct inotify_watch_context *w, *next;
127 struct notify_event ne;
129 DEBUG(10, ("inotify_dispatch called with mask=%x, name=[%s]\n",
130 e->mask, e->len ? e->name : ""));
132 /* ignore extraneous events, such as unmount and IN_IGNORED events */
133 if ((e->mask & (IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE|
134 IN_MOVED_FROM|IN_MOVED_TO)) == 0) {
138 /* map the inotify mask to a action. This gets complicated for
140 if (e->mask & IN_CREATE) {
141 ne.action = NOTIFY_ACTION_ADDED;
142 } else if (e->mask & IN_DELETE) {
143 ne.action = NOTIFY_ACTION_REMOVED;
144 } else if (e->mask & IN_MOVED_FROM) {
145 if (e2 != NULL && e2->cookie == e->cookie &&
147 ne.action = NOTIFY_ACTION_OLD_NAME;
149 ne.action = NOTIFY_ACTION_REMOVED;
151 } else if (e->mask & IN_MOVED_TO) {
152 if ((e->cookie == prev_cookie) && (e->wd == prev_wd)) {
153 ne.action = NOTIFY_ACTION_NEW_NAME;
155 ne.action = NOTIFY_ACTION_ADDED;
158 ne.action = NOTIFY_ACTION_MODIFIED;
162 DEBUG(10, ("inotify_dispatch: ne.action = %d, ne.path = %s\n",
163 ne.action, ne.path));
165 /* find any watches that have this watch descriptor */
166 for (w=in->watches;w;w=next) {
168 if (w->wd == e->wd && filter_match(w, e)) {
169 w->callback(in->ctx, w->private_data, &ne);
173 /* SMB expects a file rename to generate three events, two for
174 the rename and the other for a modify of the
175 destination. Strange! */
176 if (ne.action != NOTIFY_ACTION_NEW_NAME ||
177 (e->mask & IN_ISDIR) != 0) {
181 ne.action = NOTIFY_ACTION_MODIFIED;
184 for (w=in->watches;w;w=next) {
186 if (w->wd == e->wd && filter_match(w, e) &&
187 !(w->filter & FILE_NOTIFY_CHANGE_CREATION)) {
188 w->callback(in->ctx, w->private_data, &ne);
194 called when the kernel has some events for us
196 static void inotify_handler(struct tevent_context *ev, struct tevent_fd *fde,
197 uint16_t flags, void *private_data)
199 struct inotify_private *in = talloc_get_type(private_data,
200 struct inotify_private);
202 struct inotify_event *e0, *e;
203 uint32_t prev_cookie=0;
208 we must use FIONREAD as we cannot predict the length of the
209 filenames, and thus can't know how much to allocate
212 if (ioctl(in->fd, FIONREAD, &bufsize) != 0 ||
214 DEBUG(0,("No data on inotify fd?!\n"));
219 e0 = e = (struct inotify_event *)TALLOC_SIZE(in, bufsize + 1);
220 if (e == NULL) return;
221 ((uint8_t *)e)[bufsize] = '\0';
223 ret = read_data(in->fd, e0, bufsize);
224 if (ret != bufsize) {
225 DEBUG(0, ("Failed to read all inotify data - %s\n",
228 /* the inotify fd will now be out of sync,
229 * can't keep reading data off it */
234 /* we can get more than one event in the buffer */
235 while (e && (bufsize >= sizeof(*e))) {
236 struct inotify_event *e2 = NULL;
237 bufsize -= e->len + sizeof(*e);
238 if (bufsize >= sizeof(*e)) {
239 e2 = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e);
241 inotify_dispatch(in, e, prev_wd, prev_cookie, e2);
243 prev_cookie = e->cookie;
251 setup the inotify handle - called the first time a watch is added on
254 static NTSTATUS inotify_setup(struct sys_notify_context *ctx)
256 struct inotify_private *in;
258 in = talloc(ctx, struct inotify_private);
259 NT_STATUS_HAVE_NO_MEMORY(in);
260 in->fd = inotify_init();
262 DEBUG(0,("Failed to init inotify - %s\n", strerror(errno)));
264 return map_nt_error_from_unix(errno);
269 ctx->private_data = in;
270 talloc_set_destructor(in, inotify_destructor);
272 /* add a event waiting for the inotify fd to be readable */
273 tevent_add_fd(ctx->ev, in, in->fd, TEVENT_FD_READ, inotify_handler, in);
280 map from a change notify mask to a inotify mask. Remove any bits
283 static const struct {
284 uint32_t notify_mask;
285 uint32_t inotify_mask;
286 } inotify_mapping[] = {
287 {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
288 {FILE_NOTIFY_CHANGE_DIR_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
289 {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY},
290 {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB},
291 {FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB},
292 {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB},
293 {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB}
296 static uint32_t inotify_map(uint32_t *filter)
300 for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
301 if (inotify_mapping[i].notify_mask & *filter) {
302 out |= inotify_mapping[i].inotify_mask;
303 *filter &= ~inotify_mapping[i].notify_mask;
312 static int watch_destructor(struct inotify_watch_context *w)
314 struct inotify_private *in = w->in;
316 DLIST_REMOVE(w->in->watches, w);
318 /* only rm the watch if its the last one with this wd */
319 for (w=in->watches;w;w=w->next) {
320 if (w->wd == wd) break;
323 DEBUG(10, ("Deleting inotify watch %d\n", wd));
324 if (inotify_rm_watch(in->fd, wd) == -1) {
325 DEBUG(1, ("inotify_rm_watch returned %s\n",
335 add a watch. The watch is removed when the caller calls
336 talloc_free() on *handle
338 NTSTATUS inotify_watch(struct sys_notify_context *ctx,
341 uint32_t *subdir_filter,
342 void (*callback)(struct sys_notify_context *ctx,
344 struct notify_event *ev),
348 struct inotify_private *in;
351 struct inotify_watch_context *w;
352 uint32_t orig_filter = *filter;
353 void **handle = (void **)handle_p;
355 /* maybe setup the inotify fd */
356 if (ctx->private_data == NULL) {
358 status = inotify_setup(ctx);
359 NT_STATUS_NOT_OK_RETURN(status);
362 in = talloc_get_type(ctx->private_data, struct inotify_private);
364 mask = inotify_map(filter);
366 /* this filter can't be handled by inotify */
367 return NT_STATUS_INVALID_PARAMETER;
370 /* using IN_MASK_ADD allows us to cope with inotify() returning the same
371 watch descriptor for multiple watches on the same path */
372 mask |= (IN_MASK_ADD | IN_ONLYDIR);
374 /* get a new watch descriptor for this path */
375 wd = inotify_add_watch(in->fd, path, mask);
377 *filter = orig_filter;
378 DEBUG(1, ("inotify_add_watch returned %s\n", strerror(errno)));
379 return map_nt_error_from_unix(errno);
382 DEBUG(10, ("inotify_add_watch for %s mask %x returned wd %d\n",
385 w = talloc(in, struct inotify_watch_context);
387 inotify_rm_watch(in->fd, wd);
388 *filter = orig_filter;
389 return NT_STATUS_NO_MEMORY;
394 w->callback = callback;
395 w->private_data = private_data;
397 w->filter = orig_filter;
398 w->path = talloc_strdup(w, path);
399 if (w->path == NULL) {
400 inotify_rm_watch(in->fd, wd);
401 *filter = orig_filter;
403 return NT_STATUS_NO_MEMORY;
408 DLIST_ADD(in->watches, w);
410 /* the caller frees the handle to stop watching */
411 talloc_set_destructor(w, watch_destructor);