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"
30 #include <sys/inotify.h>
32 /* glibc < 2.5 headers don't have these defines */
34 #define IN_ONLYDIR 0x01000000
37 #define IN_MASK_ADD 0x20000000
40 struct inotify_private {
41 struct sys_notify_context *ctx;
43 struct inotify_watch_context *watches;
46 struct inotify_watch_context {
47 struct inotify_watch_context *next, *prev;
48 struct inotify_private *in;
50 void (*callback)(struct sys_notify_context *ctx,
52 struct notify_event *ev);
54 uint32_t mask; /* the inotify mask */
55 uint32_t filter; /* the windows completion filter */
61 destroy the inotify private context
63 static int inotify_destructor(struct inotify_private *in)
71 see if a particular event from inotify really does match a requested
74 static bool filter_match(struct inotify_watch_context *w,
75 struct inotify_event *e)
77 DEBUG(10, ("filter_match: e->mask=%x, w->mask=%x, w->filter=%x\n",
78 e->mask, w->mask, w->filter));
80 if ((e->mask & w->mask) == 0) {
81 /* this happens because inotify_add_watch() coalesces watches on the same
82 path, oring their masks together */
86 /* SMB separates the filters for files and directories */
87 if (e->mask & IN_ISDIR) {
88 if ((w->filter & FILE_NOTIFY_CHANGE_DIR_NAME) == 0) {
92 if ((e->mask & IN_ATTRIB) &&
93 (w->filter & (FILE_NOTIFY_CHANGE_ATTRIBUTES|
94 FILE_NOTIFY_CHANGE_LAST_WRITE|
95 FILE_NOTIFY_CHANGE_LAST_ACCESS|
96 FILE_NOTIFY_CHANGE_EA|
97 FILE_NOTIFY_CHANGE_SECURITY))) {
100 if ((e->mask & IN_MODIFY) &&
101 (w->filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)) {
104 if ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) == 0) {
115 dispatch one inotify event
117 the cookies are used to correctly handle renames
119 static void inotify_dispatch(struct inotify_private *in,
120 struct inotify_event *e,
122 uint32_t prev_cookie,
123 struct inotify_event *e2)
125 struct inotify_watch_context *w, *next;
126 struct notify_event ne;
128 DEBUG(10, ("inotify_dispatch called with mask=%x, name=[%s]\n",
129 e->mask, e->len ? e->name : ""));
131 /* ignore extraneous events, such as unmount and IN_IGNORED events */
132 if ((e->mask & (IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE|
133 IN_MOVED_FROM|IN_MOVED_TO)) == 0) {
137 /* map the inotify mask to a action. This gets complicated for
139 if (e->mask & IN_CREATE) {
140 ne.action = NOTIFY_ACTION_ADDED;
141 } else if (e->mask & IN_DELETE) {
142 ne.action = NOTIFY_ACTION_REMOVED;
143 } else if (e->mask & IN_MOVED_FROM) {
144 if (e2 != NULL && e2->cookie == e->cookie &&
146 ne.action = NOTIFY_ACTION_OLD_NAME;
148 ne.action = NOTIFY_ACTION_REMOVED;
150 } else if (e->mask & IN_MOVED_TO) {
151 if ((e->cookie == prev_cookie) && (e->wd == prev_wd)) {
152 ne.action = NOTIFY_ACTION_NEW_NAME;
154 ne.action = NOTIFY_ACTION_ADDED;
157 ne.action = NOTIFY_ACTION_MODIFIED;
161 DEBUG(10, ("inotify_dispatch: ne.action = %d, ne.path = %s\n",
162 ne.action, ne.path));
164 /* find any watches that have this watch descriptor */
165 for (w=in->watches;w;w=next) {
167 if (w->wd == e->wd && filter_match(w, e)) {
168 w->callback(in->ctx, w->private_data, &ne);
172 /* SMB expects a file rename to generate three events, two for
173 the rename and the other for a modify of the
174 destination. Strange! */
175 if (ne.action != NOTIFY_ACTION_NEW_NAME ||
176 (e->mask & IN_ISDIR) != 0) {
180 ne.action = NOTIFY_ACTION_MODIFIED;
183 for (w=in->watches;w;w=next) {
185 if (w->wd == e->wd && filter_match(w, e) &&
186 !(w->filter & FILE_NOTIFY_CHANGE_CREATION)) {
187 w->callback(in->ctx, w->private_data, &ne);
193 called when the kernel has some events for us
195 static void inotify_handler(struct tevent_context *ev, struct tevent_fd *fde,
196 uint16_t flags, void *private_data)
198 struct inotify_private *in = talloc_get_type(private_data,
199 struct inotify_private);
201 struct inotify_event *e0, *e;
202 uint32_t prev_cookie=0;
207 we must use FIONREAD as we cannot predict the length of the
208 filenames, and thus can't know how much to allocate
211 if (ioctl(in->fd, FIONREAD, &bufsize) != 0 ||
213 DEBUG(0,("No data on inotify fd?!\n"));
218 e0 = e = (struct inotify_event *)TALLOC_SIZE(in, bufsize + 1);
219 if (e == NULL) return;
220 ((uint8_t *)e)[bufsize] = '\0';
222 status = read_data_ntstatus(in->fd, (char *)e0, bufsize);
223 if (!NT_STATUS_IS_OK(status)) {
224 DEBUG(0,("Failed to read all inotify data - %s\n",
227 /* the inotify fd will now be out of sync,
228 * can't keep reading data off it */
233 /* we can get more than one event in the buffer */
234 while (e && (bufsize >= sizeof(*e))) {
235 struct inotify_event *e2 = NULL;
236 bufsize -= e->len + sizeof(*e);
237 if (bufsize >= sizeof(*e)) {
238 e2 = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e);
240 inotify_dispatch(in, e, prev_wd, prev_cookie, e2);
242 prev_cookie = e->cookie;
250 setup the inotify handle - called the first time a watch is added on
253 static NTSTATUS inotify_setup(struct sys_notify_context *ctx)
255 struct inotify_private *in;
257 if (!lp_parm_bool(-1, "notify", "inotify", True)) {
258 return NT_STATUS_INVALID_SYSTEM_SERVICE;
261 in = talloc(ctx, struct inotify_private);
262 NT_STATUS_HAVE_NO_MEMORY(in);
263 in->fd = inotify_init();
265 DEBUG(0,("Failed to init inotify - %s\n", strerror(errno)));
267 return map_nt_error_from_unix(errno);
272 ctx->private_data = in;
273 talloc_set_destructor(in, inotify_destructor);
275 /* add a event waiting for the inotify fd to be readable */
276 tevent_add_fd(ctx->ev, in, in->fd, TEVENT_FD_READ, inotify_handler, in);
283 map from a change notify mask to a inotify mask. Remove any bits
286 static const struct {
287 uint32_t notify_mask;
288 uint32_t inotify_mask;
289 } inotify_mapping[] = {
290 {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
291 {FILE_NOTIFY_CHANGE_DIR_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
292 {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY},
293 {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB},
294 {FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB},
295 {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB},
296 {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB}
299 static uint32_t inotify_map(uint32_t *filter)
303 for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
304 if (inotify_mapping[i].notify_mask & *filter) {
305 out |= inotify_mapping[i].inotify_mask;
306 *filter &= ~inotify_mapping[i].notify_mask;
315 static int watch_destructor(struct inotify_watch_context *w)
317 struct inotify_private *in = w->in;
319 DLIST_REMOVE(w->in->watches, w);
321 /* only rm the watch if its the last one with this wd */
322 for (w=in->watches;w;w=w->next) {
323 if (w->wd == wd) break;
326 DEBUG(10, ("Deleting inotify watch %d\n", wd));
327 if (inotify_rm_watch(in->fd, wd) == -1) {
328 DEBUG(1, ("inotify_rm_watch returned %s\n",
338 add a watch. The watch is removed when the caller calls
339 talloc_free() on *handle
341 NTSTATUS inotify_watch(struct sys_notify_context *ctx,
344 uint32_t *subdir_filter,
345 void (*callback)(struct sys_notify_context *ctx,
347 struct notify_event *ev),
351 struct inotify_private *in;
354 struct inotify_watch_context *w;
355 uint32_t orig_filter = *filter;
356 void **handle = (void **)handle_p;
358 /* maybe setup the inotify fd */
359 if (ctx->private_data == NULL) {
361 status = inotify_setup(ctx);
362 NT_STATUS_NOT_OK_RETURN(status);
365 in = talloc_get_type(ctx->private_data, struct inotify_private);
367 mask = inotify_map(filter);
369 /* this filter can't be handled by inotify */
370 return NT_STATUS_INVALID_PARAMETER;
373 /* using IN_MASK_ADD allows us to cope with inotify() returning the same
374 watch descriptor for multiple watches on the same path */
375 mask |= (IN_MASK_ADD | IN_ONLYDIR);
377 /* get a new watch descriptor for this path */
378 wd = inotify_add_watch(in->fd, path, mask);
380 *filter = orig_filter;
381 DEBUG(1, ("inotify_add_watch returned %s\n", strerror(errno)));
382 return map_nt_error_from_unix(errno);
385 DEBUG(10, ("inotify_add_watch for %s mask %x returned wd %d\n",
388 w = talloc(in, struct inotify_watch_context);
390 inotify_rm_watch(in->fd, wd);
391 *filter = orig_filter;
392 return NT_STATUS_NO_MEMORY;
397 w->callback = callback;
398 w->private_data = private_data;
400 w->filter = orig_filter;
401 w->path = talloc_strdup(w, path);
402 if (w->path == NULL) {
403 inotify_rm_watch(in->fd, wd);
404 *filter = orig_filter;
406 return NT_STATUS_NO_MEMORY;
411 DLIST_ADD(in->watches, w);
413 /* the caller frees the handle to stop watching */
414 talloc_set_destructor(w, watch_destructor);