source: vendor/current/source3/smbd/notify_fam.c

Last change on this file was 988, checked in by Silvan Scherrer, 9 years ago

Samba Server: update vendor to version 4.4.3
File size: 7.5 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 tevent_context *event_ctx,
71 struct tevent_fd *fd_event,
72 uint16_t flags,
73 void *private_data);
74
75static NTSTATUS fam_open_connection(FAMConnection *fam_conn,
76 struct tevent_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)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: %s\n",
109 FamErrlist[-res]));
110 /*
111 * No idea how to get NT_STATUS from a FAM result
112 */
113 FAMCONNECTION_GETFD(fam_conn) = -1;
114 return NT_STATUS_UNEXPECTED_IO_ERROR;
115 }
116
117 if (tevent_add_fd(event_ctx, event_ctx,
118 FAMCONNECTION_GETFD(fam_conn),
119 TEVENT_FD_READ, fam_handler,
120 (void *)fam_conn) == NULL) {
121 DEBUG(0, ("event_add_fd failed\n"));
122 FAMClose(fam_conn);
123 FAMCONNECTION_GETFD(fam_conn) = -1;
124 return NT_STATUS_NO_MEMORY;
125 }
126
127 return NT_STATUS_OK;
128}
129
130static void fam_reopen(FAMConnection *fam_conn,
131 struct tevent_context *event_ctx,
132 struct fam_watch_context *notify_list)
133{
134 struct fam_watch_context *ctx;
135
136 DEBUG(5, ("Re-opening FAM connection\n"));
137
138 FAMClose(fam_conn);
139
140 if (!NT_STATUS_IS_OK(fam_open_connection(fam_conn, event_ctx))) {
141 DEBUG(5, ("Re-opening fam connection failed\n"));
142 return;
143 }
144
145 for (ctx = notify_list; ctx; ctx = ctx->next) {
146 FAMMonitorDirectory(fam_conn, ctx->path, &ctx->fr, NULL);
147 }
148}
149
150static void fam_handler(struct tevent_context *event_ctx,
151 struct tevent_fd *fd_event,
152 uint16_t flags,
153 void *private_data)
154{
155 FAMConnection *fam_conn = (FAMConnection *)private_data;
156 FAMEvent fam_event;
157 struct fam_watch_context *ctx;
158 struct notify_event ne;
159
160 if (FAMPending(fam_conn) == 0) {
161 DEBUG(10, ("fam_handler called but nothing pending\n"));
162 return;
163 }
164
165 if (FAMNextEvent(fam_conn, &fam_event) != 1) {
166 DEBUG(5, ("FAMNextEvent returned an error\n"));
167 TALLOC_FREE(fd_event);
168 fam_reopen(fam_conn, event_ctx, fam_notify_list);
169 return;
170 }
171
172 DEBUG(10, ("Got FAMCode %d for %s\n", fam_event.code,
173 fam_event.filename));
174
175 switch (fam_event.code) {
176 case FAMChanged:
177 ne.action = NOTIFY_ACTION_MODIFIED;
178 break;
179 case FAMCreated:
180 ne.action = NOTIFY_ACTION_ADDED;
181 break;
182 case FAMDeleted:
183 ne.action = NOTIFY_ACTION_REMOVED;
184 break;
185 default:
186 DEBUG(10, ("Ignoring code FAMCode %d for file %s\n",
187 (int)fam_event.code, fam_event.filename));
188 return;
189 }
190
191 for (ctx = fam_notify_list; ctx; ctx = ctx->next) {
192 if (memcmp(&fam_event.fr, &ctx->fr, sizeof(FAMRequest)) == 0) {
193 break;
194 }
195 }
196
197 if (ctx == NULL) {
198 DEBUG(5, ("Discarding event for file %s\n",
199 fam_event.filename));
200 return;
201 }
202
203 if ((ne.path = strrchr_m(fam_event.filename, '\\')) == NULL) {
204 ne.path = fam_event.filename;
205 }
206 ne.dir = ctx->path;
207
208 ctx->callback(ctx->sys_ctx, ctx->private_data, &ne);
209}
210
211static int fam_watch_context_destructor(struct fam_watch_context *ctx)
212{
213 if (FAMCONNECTION_GETFD(ctx->fam_connection) != -1) {
214 FAMCancelMonitor(&fam_connection, &ctx->fr);
215 }
216 DLIST_REMOVE(fam_notify_list, ctx);
217 return 0;
218}
219
220/*
221 add a watch. The watch is removed when the caller calls
222 talloc_free() on *handle
223*/
224int _fam_watch(TALLOC_CTX *mem_ctx,
225 struct sys_notify_context *ctx,
226 const char *path,
227 uint32_t *filter,
228 uint32_t *subdir_filter,
229 void (*callback)(struct sys_notify_context *ctx,
230 void *private_data,
231 struct notify_event *ev),
232 void *private_data,
233 void *handle_p)
234{
235 const uint32_t fam_mask = (FILE_NOTIFY_CHANGE_FILE_NAME|
236 FILE_NOTIFY_CHANGE_DIR_NAME);
237 struct fam_watch_context *watch;
238 void **handle = (void **)handle_p;
239
240 *handle = NULL;
241
242 if ((*filter & fam_mask) == 0) {
243 DEBUG(10, ("filter = %u, ignoring in FAM\n", *filter));
244 return 0;
245 }
246
247 if (!fam_connection_initialized) {
248 if (!NT_STATUS_IS_OK(fam_open_connection(&fam_connection,
249 ctx->ev))) {
250 /*
251 * Just let smbd do all the work itself
252 */
253 return 0;
254 }
255 fam_connection_initialized = True;
256 }
257
258 if (!(watch = talloc(mem_ctx, struct fam_watch_context))) {
259 return ENOMEM;
260 }
261
262 watch->fam_connection = &fam_connection;
263
264 watch->callback = callback;
265 watch->private_data = private_data;
266 watch->sys_ctx = ctx;
267
268 watch->path = talloc_strdup(watch, path);
269 if (watch->path == NULL) {
270 DEBUG(0, ("talloc_asprintf failed\n"));
271 TALLOC_FREE(watch);
272 return ENOMEM;
273 }
274
275 /*
276 * The FAM module in this early state will only take care of
277 * FAMCreated and FAMDeleted events, Leave the rest to notifyd
278 */
279
280 watch->filter = fam_mask;
281 *filter &= ~fam_mask;
282
283 DLIST_ADD(fam_notify_list, watch);
284 talloc_set_destructor(watch, fam_watch_context_destructor);
285
286 /*
287 * Only directories monitored so far
288 */
289
290 if (FAMCONNECTION_GETFD(watch->fam_connection) != -1) {
291 FAMMonitorDirectory(watch->fam_connection, watch->path,
292 &watch->fr, NULL);
293 }
294 else {
295 /*
296 * If the re-open is successful, this will establish the
297 * FAMMonitor from the list
298 */
299 fam_reopen(watch->fam_connection, ctx->ev, fam_notify_list);
300 }
301
302 *handle = watch;
303
304 return 0;
305}
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