1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
/* -*- mode: C; c-file-style: "gnu" -*- */
/* dir-watch-inotify.c OS specific directory change notification for message bus
*
* Copyright (C) 2003 Red Hat, Inc.
* (c) 2006 Mandriva
*
* Licensed under the Academic Free License version 2.1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <config.h>
#define _GNU_SOURCE
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/inotify.h>
#include <sys/types.h>
#include <signal.h>
#include <errno.h>
#include <dbus/dbus-internals.h>
#include <dbus/dbus-list.h>
#include <dbus/dbus-watch.h>
#include "dir-watch.h"
#define MAX_DIRS_TO_WATCH 128
#define INOTIFY_EVENT_SIZE (sizeof(struct inotify_event))
#define INOTIFY_BUF_LEN (1024 * (INOTIFY_EVENT_SIZE + 16))
/* use a static array to avoid handling OOM */
static int wds[MAX_DIRS_TO_WATCH];
static char *dirs[MAX_DIRS_TO_WATCH];
static int num_wds = 0;
static int inotify_fd = -1;
static DBusWatch *watch = NULL;
static DBusLoop *loop = NULL;
static dbus_bool_t
_inotify_watch_callback (DBusWatch *watch, unsigned int condition, void *data)
{
return dbus_watch_handle (watch, condition);
}
static dbus_bool_t
_handle_inotify_watch (DBusWatch *passed_watch, unsigned int flags, void *data)
{
char buffer[INOTIFY_BUF_LEN];
ssize_t ret = 0;
int i = 0;
pid_t pid;
dbus_bool_t have_change = FALSE;
ret = read (inotify_fd, buffer, INOTIFY_BUF_LEN);
if (ret < 0)
_dbus_verbose ("Error reading inotify event: '%s'\n", _dbus_strerror(errno));
else if (!ret)
_dbus_verbose ("Error reading inotify event: buffer too small\n");
while (i < ret)
{
struct inotify_event *ev;
pid = _dbus_getpid ();
ev = (struct inotify_event *) &buffer[i];
i += INOTIFY_EVENT_SIZE + ev->len;
#ifdef DBUS_ENABLE_VERBOSE_MODE
if (ev->len)
_dbus_verbose ("event name: '%s'\n", ev->name);
_dbus_verbose ("inotify event: wd=%d mask=%u cookie=%u len=%u\n", ev->wd, ev->mask, ev->cookie, ev->len);
#endif
_dbus_verbose ("Sending SIGHUP signal on reception of a inotify event\n");
have_change = TRUE;
}
if (have_change)
(void) kill (pid, SIGHUP);
return TRUE;
}
static int
_init_inotify (BusContext *context)
{
int ret = 0;
if (inotify_fd == -1) {
#ifdef HAVE_INOTIFY_INIT1
inotify_fd = inotify_init1 (IN_CLOEXEC);
#else
inotify_fd = inotify_init ();
#endif
if (inotify_fd <= 0) {
_dbus_warn ("Cannot initialize inotify\n");
goto out;
}
loop = bus_context_get_loop (context);
watch = _dbus_watch_new (inotify_fd, DBUS_WATCH_READABLE, TRUE,
_handle_inotify_watch, NULL, NULL);
if (watch == NULL)
{
_dbus_warn ("Unable to create inotify watch\n");
goto out;
}
if (!_dbus_loop_add_watch (loop, watch, _inotify_watch_callback,
NULL, NULL))
{
_dbus_warn ("Unable to add reload watch to main loop");
_dbus_watch_unref (watch);
watch = NULL;
goto out;
}
}
ret = 1;
out:
return ret;
}
void
bus_set_watched_dirs (BusContext *context, DBusList **directories)
{
int new_wds[MAX_DIRS_TO_WATCH];
char *new_dirs[MAX_DIRS_TO_WATCH];
DBusList *link;
int i, j, wd;
if (!_init_inotify (context))
goto out;
for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
{
new_wds[i] = -1;
new_dirs[i] = NULL;
}
i = 0;
link = _dbus_list_get_first_link (directories);
while (link != NULL)
{
new_dirs[i++] = (char *)link->data;
link = _dbus_list_get_next_link (directories, link);
}
/* Look for directories in both the old and new sets, if
* we find one, move its data into the new set.
*/
for (i = 0; new_dirs[i]; i++)
{
for (j = 0; j < num_wds; j++)
{
if (dirs[j] && strcmp (new_dirs[i], dirs[j]) == 0)
{
new_wds[i] = wds[j];
new_dirs[i] = dirs[j];
wds[j] = -1;
dirs[j] = NULL;
break;
}
}
}
/* Any directories we find in "wds" with a nonzero fd must
* not be in the new set, so perform cleanup now.
*/
for (j = 0; j < num_wds; j++)
{
if (wds[j] != -1)
{
inotify_rm_watch (inotify_fd, wds[j]);
dbus_free (dirs[j]);
wds[j] = -1;
dirs[j] = NULL;
}
}
for (i = 0; new_dirs[i]; i++)
{
if (new_wds[i] == -1)
{
/* FIXME - less lame error handling for failing to add a watch; we may need to sleep. */
wd = inotify_add_watch (inotify_fd, new_dirs[i], IN_CLOSE_WRITE | IN_DELETE | IN_MOVED_TO | IN_MOVED_FROM);
if (wd < 0)
{
_dbus_warn ("Cannot setup inotify for '%s'; error '%s'\n", new_dirs[i], _dbus_strerror (errno));
goto out;
}
new_wds[i] = wd;
new_dirs[i] = _dbus_strdup (new_dirs[i]);
if (!new_dirs[i])
{
/* FIXME have less lame handling for OOM, we just silently fail to
* watch. (In reality though, the whole OOM handling in dbus is stupid
* but we won't go into that in this comment =) )
*/
inotify_rm_watch (inotify_fd, wd);
new_wds[i] = -1;
}
}
}
num_wds = i;
for (i = 0; i < MAX_DIRS_TO_WATCH; i++)
{
wds[i] = new_wds[i];
dirs[i] = new_dirs[i];
}
out:;
}
|
