1 /* -*- mode: C; c-file-style: "gnu" -*- */
2 /* dir-watch-kqueue.c OS specific directory change notification for message bus
3 *
4 * Copyright (C) 2003 Red Hat, Inc.
5 *
6 * Licensed under the Academic Free License version 2.1
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 *
22 */
23
24 #include <config.h>
25
26 #include <sys/types.h>
27 #include <sys/event.h>
28 #include <sys/time.h>
29 #include <signal.h>
30 #include <fcntl.h>
31 #include <unistd.h>
32 #include "bus.h"
33 #include <dbus/dbus-watch.h>
34
35 #include <dbus/dbus-internals.h>
36 #include "dir-watch.h"
37
38 #define MAX_DIRS_TO_WATCH 128
39
40 static int kq = -1;
41 static int fds[MAX_DIRS_TO_WATCH];
42 static int num_fds = 0;
43 static DBusWatch *watch = NULL;
44 static DBusLoop *loop = NULL;
45
46 static dbus_bool_t
_kqueue_watch_callback(DBusWatch * watch,unsigned int condition,void * data)47 _kqueue_watch_callback (DBusWatch *watch, unsigned int condition, void *data)
48 {
49 return dbus_watch_handle (watch, condition);
50 }
51
52 static dbus_bool_t
_handle_kqueue_watch(DBusWatch * watch,unsigned int flags,void * data)53 _handle_kqueue_watch (DBusWatch *watch, unsigned int flags, void *data)
54 {
55 struct kevent ev;
56 struct timespec nullts = { 0, 0 };
57 int res;
58 pid_t pid;
59
60 res = kevent (kq, NULL, 0, &ev, 1, &nullts);
61
62 /* Sleep for half a second to avoid a race when files are install(1)'d
63 * to system.d. */
64 usleep(500000);
65
66 if (res > 0)
67 {
68 pid = getpid ();
69 _dbus_verbose ("Sending SIGHUP signal on reception of a kevent\n");
70 (void) kill (pid, SIGHUP);
71 }
72 else if (res < 0 && errno == EBADF)
73 {
74 kq = -1;
75 if (watch != NULL)
76 {
77 _dbus_loop_remove_watch (loop, watch, _kqueue_watch_callback, NULL);
78 _dbus_watch_unref (watch);
79 watch = NULL;
80 }
81 pid = getpid ();
82 _dbus_verbose ("Sending SIGHUP signal since kqueue has been closed\n");
83 (void) kill (pid, SIGHUP);
84 }
85
86 return TRUE;
87 }
88
89 void
bus_watch_directory(const char * dir,BusContext * context)90 bus_watch_directory (const char *dir, BusContext *context)
91 {
92 int fd;
93 struct kevent ev;
94
95 _dbus_assert (dir != NULL);
96
97 if (kq < 0)
98 {
99
100 kq = kqueue ();
101 if (kq < 0)
102 {
103 _dbus_warn ("Cannot create kqueue; error '%s'\n", _dbus_strerror (errno));
104 goto out;
105 }
106
107 loop = bus_context_get_loop (context);
108
109 watch = _dbus_watch_new (kq, DBUS_WATCH_READABLE, TRUE,
110 _handle_kqueue_watch, NULL, NULL);
111
112 if (watch == NULL)
113 {
114 _dbus_warn ("Unable to create kqueue watch\n");
115 close (kq);
116 kq = -1;
117 goto out;
118 }
119
120 if (!_dbus_loop_add_watch (loop, watch, _kqueue_watch_callback,
121 NULL, NULL))
122 {
123 _dbus_warn ("Unable to add reload watch to main loop");
124 close (kq);
125 kq = -1;
126 _dbus_watch_unref (watch);
127 watch = NULL;
128 goto out;
129 }
130 }
131
132 if (num_fds >= MAX_DIRS_TO_WATCH )
133 {
134 _dbus_warn ("Cannot watch config directory '%s'. Already watching %d directories\n", dir, MAX_DIRS_TO_WATCH);
135 goto out;
136 }
137
138 fd = open (dir, O_RDONLY);
139 if (fd < 0)
140 {
141 _dbus_warn ("Cannot open directory '%s'; error '%s'\n", dir, _dbus_strerror (errno));
142 goto out;
143 }
144
145 EV_SET (&ev, fd, EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_CLEAR,
146 NOTE_DELETE | NOTE_EXTEND | NOTE_WRITE | NOTE_RENAME, 0, 0);
147 if (kevent (kq, &ev, 1, NULL, 0, NULL) == -1)
148 {
149 _dbus_warn ("Cannot setup a kevent for '%s'; error '%s'\n", dir, _dbus_strerror (errno));
150 close (fd);
151 goto out;
152 }
153
154 fds[num_fds++] = fd;
155 _dbus_verbose ("Added kqueue watch on config directory '%s'\n", dir);
156
157 out:
158 ;
159 }
160
161 void
bus_drop_all_directory_watches(void)162 bus_drop_all_directory_watches (void)
163 {
164 int i;
165
166 _dbus_verbose ("Dropping all watches on config directories\n");
167
168 for (i = 0; i < num_fds; i++)
169 {
170 if (close (fds[i]) != 0)
171 {
172 _dbus_verbose ("Error closing fd %d for config directory watch\n", fds[i]);
173 }
174 }
175
176 num_fds = 0;
177 }
178