source: trunk/server/source3/modules/vfs_notify_fam.c

Last change on this file was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 8.1 KB
Line 
1/*
2 * FAM file notification support.
3 *
4 * Copyright (c) James Peach 2005
5 * Copyright (c) Volker Lendecke 2007
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 */
20
21#include "includes.h"
22#include "smbd/smbd.h"
23#include "librpc/gen_ndr/notify.h"
24
25#include <fam.h>
26
27#if !defined(HAVE_FAM_H_FAMCODES_TYPEDEF)
28/* Gamin provides this typedef which means we can't use 'enum FAMCodes' as per
29 * every other FAM implementation. Phooey.
30 */
31typedef enum FAMCodes FAMCodes;
32#endif
33
34/* NOTE: There are multiple versions of FAM floating around the net, each with
35 * slight differences from the original SGI FAM implementation. In this file,
36 * we rely only on the SGI features and do not assume any extensions. For
37 * example, we do not look at FAMErrno, because it is not set by the original
38 * implementation.
39 *
40 * Random FAM links:
41 * http://oss.sgi.com/projects/fam/
42 * http://savannah.nongnu.org/projects/fam/
43 * http://sourceforge.net/projects/bsdfam/
44 */
45
46/* ------------------------------------------------------------------------- */
47
48struct fam_watch_context {
49 struct fam_watch_context *prev, *next;
50 FAMConnection *fam_connection;
51 struct FAMRequest fr;
52 struct sys_notify_context *sys_ctx;
53 void (*callback)(struct sys_notify_context *ctx,
54 void *private_data,
55 struct notify_event *ev);
56 void *private_data;
57 uint32_t mask; /* the inotify mask */
58 uint32_t filter; /* the windows completion filter */
59 const char *path;
60};
61
62
63/*
64 * We want one FAM connection per smbd, not one per tcon.
65 */
66static FAMConnection fam_connection;
67static bool fam_connection_initialized = False;
68
69static struct fam_watch_context *fam_notify_list;
70static void fam_handler(struct event_context *event_ctx,
71 struct fd_event *fd_event,
72 uint16 flags,
73 void *private_data);
74
75static NTSTATUS fam_open_connection(FAMConnection *fam_conn,
76 struct event_context *event_ctx)
77{
78 int res;
79 char *name;
80
81 ZERO_STRUCTP(fam_conn);
82 FAMCONNECTION_GETFD(fam_conn) = -1;
83
84
85#ifdef HAVE_FAMNOEXISTS
86 /* We should honor outside setting of the GAM_CLIENT_ID. */
87 setenv("GAM_CLIENT_ID","SAMBA",0);
88#endif
89
90 if (asprintf(&name, "smbd (%lu)", (unsigned long)sys_getpid()) == -1) {
91 DEBUG(0, ("No memory\n"));
92 return NT_STATUS_NO_MEMORY;
93 }
94
95 res = FAMOpen2(fam_conn, name);
96
97#ifdef HAVE_FAMNOEXISTS
98 /*
99 * This reduces the chatter between GAMIN and samba making the pair
100 * much more reliable.
101 */
102 FAMNoExists(fam_conn);
103#endif
104
105 SAFE_FREE(name);
106
107 if (res < 0) {
108 DEBUG(10, ("FAM file change notifications not available\n"));
109 /*
110 * No idea how to get NT_STATUS from a FAM result
111 */
112 FAMCONNECTION_GETFD(fam_conn) = -1;
113 return NT_STATUS_UNEXPECTED_IO_ERROR;
114 }
115
116 if (event_add_fd(event_ctx, event_ctx,
117 FAMCONNECTION_GETFD(fam_conn),
118 EVENT_FD_READ, fam_handler,
119 (void *)fam_conn) == NULL) {
120 DEBUG(0, ("event_add_fd failed\n"));
121 FAMClose(fam_conn);
122 FAMCONNECTION_GETFD(fam_conn) = -1;
123 return NT_STATUS_NO_MEMORY;
124 }
125
126 return NT_STATUS_OK;
127}
128
129static void fam_reopen(FAMConnection *fam_conn,
130 struct event_context *event_ctx,
131 struct fam_watch_context *notify_list)
132{
133 struct fam_watch_context *ctx;
134
135 DEBUG(5, ("Re-opening FAM connection\n"));
136
137 FAMClose(fam_conn);
138
139 if (!NT_STATUS_IS_OK(fam_open_connection(fam_conn, event_ctx))) {
140 DEBUG(5, ("Re-opening fam connection failed\n"));
141 return;
142 }
143
144 for (ctx = notify_list; ctx; ctx = ctx->next) {
145 FAMMonitorDirectory(fam_conn, ctx->path, &ctx->fr, NULL);
146 }
147}
148
149static void fam_handler(struct event_context *event_ctx,
150 struct fd_event *fd_event,
151 uint16 flags,
152 void *private_data)
153{
154 FAMConnection *fam_conn = (FAMConnection *)private_data;
155 FAMEvent fam_event;
156 struct fam_watch_context *ctx;
157 struct notify_event ne;
158
159 if (FAMPending(fam_conn) == 0) {
160 DEBUG(10, ("fam_handler called but nothing pending\n"));
161 return;
162 }
163
164 if (FAMNextEvent(fam_conn, &fam_event) != 1) {
165 DEBUG(5, ("FAMNextEvent returned an error\n"));
166 TALLOC_FREE(fd_event);
167 fam_reopen(fam_conn, event_ctx, fam_notify_list);
168 return;
169 }
170
171 DEBUG(10, ("Got FAMCode %d for %s\n", fam_event.code,
172 fam_event.filename));
173
174 switch (fam_event.code) {
175 case FAMChanged:
176 ne.action = NOTIFY_ACTION_MODIFIED;
177 break;
178 case FAMCreated:
179 ne.action = NOTIFY_ACTION_ADDED;
180 break;
181 case FAMDeleted:
182 ne.action = NOTIFY_ACTION_REMOVED;
183 break;
184 default:
185 DEBUG(10, ("Ignoring code FAMCode %d for file %s\n",
186 (int)fam_event.code, fam_event.filename));
187 return;
188 }
189
190 for (ctx = fam_notify_list; ctx; ctx = ctx->next) {
191 if (memcmp(&fam_event.fr, &ctx->fr, sizeof(FAMRequest)) == 0) {
192 break;
193 }
194 }
195
196 if (ctx == NULL) {
197 DEBUG(5, ("Discarding event for file %s\n",
198 fam_event.filename));
199 return;
200 }
201
202 if ((ne.path = strrchr_m(fam_event.filename, '\\')) == NULL) {
203 ne.path = fam_event.filename;
204 }
205
206 ctx->callback(ctx->sys_ctx, ctx->private_data, &ne);
207}
208
209static int fam_watch_context_destructor(struct fam_watch_context *ctx)
210{
211 if (FAMCONNECTION_GETFD(ctx->fam_connection) != -1) {
212 FAMCancelMonitor(&fam_connection, &ctx->fr);
213 }
214 DLIST_REMOVE(fam_notify_list, ctx);
215 return 0;
216}
217
218/*
219 add a watch. The watch is removed when the caller calls
220 talloc_free() on *handle
221*/
222static NTSTATUS fam_watch(vfs_handle_struct *vfs_handle,
223 struct sys_notify_context *ctx,
224 struct notify_entry *e,
225 void (*callback)(struct sys_notify_context *ctx,
226 void *private_data,
227 struct notify_event *ev),
228 void *private_data,
229 void *handle_p)
230{
231 const uint32 fam_mask = (FILE_NOTIFY_CHANGE_FILE_NAME|
232 FILE_NOTIFY_CHANGE_DIR_NAME);
233 struct fam_watch_context *watch;
234 void **handle = (void **)handle_p;
235
236 if ((e->filter & fam_mask) == 0) {
237 DEBUG(10, ("filter = %u, ignoring in FAM\n", e->filter));
238 return NT_STATUS_OK;
239 }
240
241 if (!fam_connection_initialized) {
242 if (!NT_STATUS_IS_OK(fam_open_connection(&fam_connection,
243 ctx->ev))) {
244 /*
245 * Just let smbd do all the work itself
246 */
247 return NT_STATUS_OK;
248 }
249 fam_connection_initialized = True;
250 }
251
252 if (!(watch = TALLOC_P(ctx, struct fam_watch_context))) {
253 return NT_STATUS_NO_MEMORY;
254 }
255
256 watch->fam_connection = &fam_connection;
257
258 watch->callback = callback;
259 watch->private_data = private_data;
260 watch->sys_ctx = ctx;
261
262 if (!(watch->path = talloc_strdup(watch, e->path))) {
263 DEBUG(0, ("talloc_asprintf failed\n"));
264 TALLOC_FREE(watch);
265 return NT_STATUS_NO_MEMORY;
266 }
267
268 /*
269 * The FAM module in this early state will only take care of
270 * FAMCreated and FAMDeleted events, Leave the rest to
271 * notify_internal.c
272 */
273
274 watch->filter = fam_mask;
275 e->filter &= ~fam_mask;
276
277 DLIST_ADD(fam_notify_list, watch);
278 talloc_set_destructor(watch, fam_watch_context_destructor);
279
280 /*
281 * Only directories monitored so far
282 */
283
284 if (FAMCONNECTION_GETFD(watch->fam_connection) != -1) {
285 FAMMonitorDirectory(watch->fam_connection, watch->path,
286 &watch->fr, NULL);
287 }
288 else {
289 /*
290 * If the re-open is successful, this will establish the
291 * FAMMonitor from the list
292 */
293 fam_reopen(watch->fam_connection, ctx->ev, fam_notify_list);
294 }
295
296 *handle = (void *)watch;
297
298 return NT_STATUS_OK;
299}
300
301/* VFS operations structure */
302
303static struct vfs_fn_pointers notify_fam_fns = {
304 .notify_watch = fam_watch,
305};
306
307
308NTSTATUS vfs_notify_fam_init(void);
309NTSTATUS vfs_notify_fam_init(void)
310{
311 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "notify_fam",
312 &notify_fam_fns);
313}
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