s3:smbd: s/event_add_fd/tevent_add_fd and s/EVENT_FD_/TEVENT_FD_
[Samba/gebeck_regimport.git] / source3 / smbd / notify_inotify.c
blob4e9a87e6f9fbaa2cfbe031797dd9d8ca1804d29d
1 /*
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
24 #include "includes.h"
25 #include "../librpc/gen_ndr/notify.h"
26 #include "smbd/smbd.h"
28 #ifdef HAVE_INOTIFY
30 #include <sys/inotify.h>
32 /* glibc < 2.5 headers don't have these defines */
33 #ifndef IN_ONLYDIR
34 #define IN_ONLYDIR 0x01000000
35 #endif
36 #ifndef IN_MASK_ADD
37 #define IN_MASK_ADD 0x20000000
38 #endif
40 struct inotify_private {
41 struct sys_notify_context *ctx;
42 int fd;
43 struct inotify_watch_context *watches;
46 struct inotify_watch_context {
47 struct inotify_watch_context *next, *prev;
48 struct inotify_private *in;
49 int wd;
50 void (*callback)(struct sys_notify_context *ctx,
51 void *private_data,
52 struct notify_event *ev);
53 void *private_data;
54 uint32_t mask; /* the inotify mask */
55 uint32_t filter; /* the windows completion filter */
56 const char *path;
61 destroy the inotify private context
63 static int inotify_destructor(struct inotify_private *in)
65 close(in->fd);
66 return 0;
71 see if a particular event from inotify really does match a requested
72 notify event in SMB
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 */
83 return False;
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) {
89 return False;
91 } else {
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))) {
98 return True;
100 if ((e->mask & IN_MODIFY) &&
101 (w->filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)) {
102 return True;
104 if ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) == 0) {
105 return False;
109 return True;
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,
121 uint32_t prev_cookie,
122 struct inotify_event *e2)
124 struct inotify_watch_context *w, *next;
125 struct notify_event ne;
127 DEBUG(10, ("inotify_dispatch called with mask=%x, name=[%s]\n",
128 e->mask, e->len ? e->name : ""));
130 /* ignore extraneous events, such as unmount and IN_IGNORED events */
131 if ((e->mask & (IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE|
132 IN_MOVED_FROM|IN_MOVED_TO)) == 0) {
133 return;
136 /* map the inotify mask to a action. This gets complicated for
137 renames */
138 if (e->mask & IN_CREATE) {
139 ne.action = NOTIFY_ACTION_ADDED;
140 } else if (e->mask & IN_DELETE) {
141 ne.action = NOTIFY_ACTION_REMOVED;
142 } else if (e->mask & IN_MOVED_FROM) {
143 if (e2 != NULL && e2->cookie == e->cookie) {
144 ne.action = NOTIFY_ACTION_OLD_NAME;
145 } else {
146 ne.action = NOTIFY_ACTION_REMOVED;
148 } else if (e->mask & IN_MOVED_TO) {
149 if (e->cookie == prev_cookie) {
150 ne.action = NOTIFY_ACTION_NEW_NAME;
151 } else {
152 ne.action = NOTIFY_ACTION_ADDED;
154 } else {
155 ne.action = NOTIFY_ACTION_MODIFIED;
157 ne.path = e->name;
159 DEBUG(10, ("inotify_dispatch: ne.action = %d, ne.path = %s\n",
160 ne.action, ne.path));
162 /* find any watches that have this watch descriptor */
163 for (w=in->watches;w;w=next) {
164 next = w->next;
165 if (w->wd == e->wd && filter_match(w, e)) {
166 w->callback(in->ctx, w->private_data, &ne);
170 /* SMB expects a file rename to generate three events, two for
171 the rename and the other for a modify of the
172 destination. Strange! */
173 if (ne.action != NOTIFY_ACTION_NEW_NAME ||
174 (e->mask & IN_ISDIR) != 0) {
175 return;
178 ne.action = NOTIFY_ACTION_MODIFIED;
179 e->mask = IN_ATTRIB;
181 for (w=in->watches;w;w=next) {
182 next = w->next;
183 if (w->wd == e->wd && filter_match(w, e) &&
184 !(w->filter & FILE_NOTIFY_CHANGE_CREATION)) {
185 w->callback(in->ctx, w->private_data, &ne);
191 called when the kernel has some events for us
193 static void inotify_handler(struct tevent_context *ev, struct tevent_fd *fde,
194 uint16_t flags, void *private_data)
196 struct inotify_private *in = talloc_get_type(private_data,
197 struct inotify_private);
198 int bufsize = 0;
199 struct inotify_event *e0, *e;
200 uint32_t prev_cookie=0;
201 NTSTATUS status;
204 we must use FIONREAD as we cannot predict the length of the
205 filenames, and thus can't know how much to allocate
206 otherwise
208 if (ioctl(in->fd, FIONREAD, &bufsize) != 0 ||
209 bufsize == 0) {
210 DEBUG(0,("No data on inotify fd?!\n"));
211 TALLOC_FREE(fde);
212 return;
215 e0 = e = (struct inotify_event *)TALLOC_SIZE(in, bufsize + 1);
216 if (e == NULL) return;
217 ((uint8_t *)e)[bufsize] = '\0';
219 status = read_data(in->fd, (char *)e0, bufsize);
220 if (!NT_STATUS_IS_OK(status)) {
221 DEBUG(0,("Failed to read all inotify data - %s\n",
222 nt_errstr(status)));
223 talloc_free(e0);
224 /* the inotify fd will now be out of sync,
225 * can't keep reading data off it */
226 TALLOC_FREE(fde);
227 return;
230 /* we can get more than one event in the buffer */
231 while (e && (bufsize >= sizeof(*e))) {
232 struct inotify_event *e2 = NULL;
233 bufsize -= e->len + sizeof(*e);
234 if (bufsize >= sizeof(*e)) {
235 e2 = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e);
237 inotify_dispatch(in, e, prev_cookie, e2);
238 prev_cookie = e->cookie;
239 e = e2;
242 talloc_free(e0);
246 setup the inotify handle - called the first time a watch is added on
247 this context
249 static NTSTATUS inotify_setup(struct sys_notify_context *ctx)
251 struct inotify_private *in;
253 if (!lp_parm_bool(-1, "notify", "inotify", True)) {
254 return NT_STATUS_INVALID_SYSTEM_SERVICE;
257 in = talloc(ctx, struct inotify_private);
258 NT_STATUS_HAVE_NO_MEMORY(in);
259 in->fd = inotify_init();
260 if (in->fd == -1) {
261 DEBUG(0,("Failed to init inotify - %s\n", strerror(errno)));
262 talloc_free(in);
263 return map_nt_error_from_unix(errno);
265 in->ctx = ctx;
266 in->watches = NULL;
268 ctx->private_data = in;
269 talloc_set_destructor(in, inotify_destructor);
271 /* add a event waiting for the inotify fd to be readable */
272 tevent_add_fd(ctx->ev, in, in->fd, TEVENT_FD_READ, inotify_handler, in);
274 return NT_STATUS_OK;
279 map from a change notify mask to a inotify mask. Remove any bits
280 which we can handle
282 static const struct {
283 uint32_t notify_mask;
284 uint32_t inotify_mask;
285 } inotify_mapping[] = {
286 {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
287 {FILE_NOTIFY_CHANGE_DIR_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
288 {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY},
289 {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB},
290 {FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB},
291 {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB},
292 {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB}
295 static uint32_t inotify_map(uint32_t *filter)
297 int i;
298 uint32_t out=0;
299 for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
300 if (inotify_mapping[i].notify_mask & *filter) {
301 out |= inotify_mapping[i].inotify_mask;
302 *filter &= ~inotify_mapping[i].notify_mask;
305 return out;
309 destroy a watch
311 static int watch_destructor(struct inotify_watch_context *w)
313 struct inotify_private *in = w->in;
314 int wd = w->wd;
315 DLIST_REMOVE(w->in->watches, w);
317 /* only rm the watch if its the last one with this wd */
318 for (w=in->watches;w;w=w->next) {
319 if (w->wd == wd) break;
321 if (w == NULL) {
322 DEBUG(10, ("Deleting inotify watch %d\n", wd));
323 if (inotify_rm_watch(in->fd, wd) == -1) {
324 DEBUG(1, ("inotify_rm_watch returned %s\n",
325 strerror(errno)));
329 return 0;
334 add a watch. The watch is removed when the caller calls
335 talloc_free() on *handle
337 NTSTATUS inotify_watch(struct sys_notify_context *ctx,
338 const char *path,
339 uint32_t *filter,
340 uint32_t *subdir_filter,
341 void (*callback)(struct sys_notify_context *ctx,
342 void *private_data,
343 struct notify_event *ev),
344 void *private_data,
345 void *handle_p)
347 struct inotify_private *in;
348 int wd;
349 uint32_t mask;
350 struct inotify_watch_context *w;
351 uint32_t orig_filter = *filter;
352 void **handle = (void **)handle_p;
354 /* maybe setup the inotify fd */
355 if (ctx->private_data == NULL) {
356 NTSTATUS status;
357 status = inotify_setup(ctx);
358 NT_STATUS_NOT_OK_RETURN(status);
361 in = talloc_get_type(ctx->private_data, struct inotify_private);
363 mask = inotify_map(filter);
364 if (mask == 0) {
365 /* this filter can't be handled by inotify */
366 return NT_STATUS_INVALID_PARAMETER;
369 /* using IN_MASK_ADD allows us to cope with inotify() returning the same
370 watch descriptor for multiple watches on the same path */
371 mask |= (IN_MASK_ADD | IN_ONLYDIR);
373 /* get a new watch descriptor for this path */
374 wd = inotify_add_watch(in->fd, path, mask);
375 if (wd == -1) {
376 *filter = orig_filter;
377 DEBUG(1, ("inotify_add_watch returned %s\n", strerror(errno)));
378 return map_nt_error_from_unix(errno);
381 DEBUG(10, ("inotify_add_watch for %s mask %x returned wd %d\n",
382 path, mask, wd));
384 w = talloc(in, struct inotify_watch_context);
385 if (w == NULL) {
386 inotify_rm_watch(in->fd, wd);
387 *filter = orig_filter;
388 return NT_STATUS_NO_MEMORY;
391 w->in = in;
392 w->wd = wd;
393 w->callback = callback;
394 w->private_data = private_data;
395 w->mask = mask;
396 w->filter = orig_filter;
397 w->path = talloc_strdup(w, path);
398 if (w->path == NULL) {
399 inotify_rm_watch(in->fd, wd);
400 *filter = orig_filter;
401 return NT_STATUS_NO_MEMORY;
404 (*handle) = w;
406 DLIST_ADD(in->watches, w);
408 /* the caller frees the handle to stop watching */
409 talloc_set_destructor(w, watch_destructor);
411 return NT_STATUS_OK;
414 #endif