Emeric Vigier | 2f62582 | 2012-08-06 11:09:52 -0400 | [diff] [blame] | 1 | /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ |
| 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 | #ifdef HAVE_ERRNO_H |
| 33 | #include <errno.h> |
| 34 | #endif |
| 35 | |
| 36 | #include "bus.h" |
| 37 | #include <dbus/dbus-watch.h> |
| 38 | |
| 39 | #include <dbus/dbus-internals.h> |
| 40 | #include <dbus/dbus-list.h> |
| 41 | #include "dir-watch.h" |
| 42 | |
| 43 | #define MAX_DIRS_TO_WATCH 128 |
| 44 | |
| 45 | static int kq = -1; |
| 46 | static int fds[MAX_DIRS_TO_WATCH]; |
| 47 | static char *dirs[MAX_DIRS_TO_WATCH]; |
| 48 | static int num_fds = 0; |
| 49 | static DBusWatch *watch = NULL; |
| 50 | static DBusLoop *loop = NULL; |
| 51 | |
| 52 | static dbus_bool_t |
| 53 | _kqueue_watch_callback (DBusWatch *watch, unsigned int condition, void *data) |
| 54 | { |
| 55 | return dbus_watch_handle (watch, condition); |
| 56 | } |
| 57 | |
| 58 | static dbus_bool_t |
| 59 | _handle_kqueue_watch (DBusWatch *watch, unsigned int flags, void *data) |
| 60 | { |
| 61 | struct kevent ev; |
| 62 | struct timespec nullts = { 0, 0 }; |
| 63 | int res; |
| 64 | pid_t pid; |
| 65 | |
| 66 | res = kevent (kq, NULL, 0, &ev, 1, &nullts); |
| 67 | |
| 68 | /* Sleep for half a second to avoid a race when files are install(1)'d |
| 69 | * to system.d. */ |
| 70 | usleep(500000); |
| 71 | |
| 72 | if (res > 0) |
| 73 | { |
| 74 | pid = getpid (); |
| 75 | _dbus_verbose ("Sending SIGHUP signal on reception of a kevent\n"); |
| 76 | (void) kill (pid, SIGHUP); |
| 77 | } |
| 78 | else if (res < 0 && errno == EBADF) |
| 79 | { |
| 80 | kq = -1; |
| 81 | if (watch != NULL) |
| 82 | { |
| 83 | _dbus_loop_remove_watch (loop, watch, _kqueue_watch_callback, NULL); |
| 84 | _dbus_watch_unref (watch); |
| 85 | watch = NULL; |
| 86 | } |
| 87 | pid = getpid (); |
| 88 | _dbus_verbose ("Sending SIGHUP signal since kqueue has been closed\n"); |
| 89 | (void) kill (pid, SIGHUP); |
| 90 | } |
| 91 | |
| 92 | return TRUE; |
| 93 | } |
| 94 | |
| 95 | static int |
| 96 | _init_kqueue (BusContext *context) |
| 97 | { |
| 98 | int ret = 0; |
| 99 | |
| 100 | if (kq < 0) |
| 101 | { |
| 102 | |
| 103 | kq = kqueue (); |
| 104 | if (kq < 0) |
| 105 | { |
| 106 | _dbus_warn ("Cannot create kqueue; error '%s'\n", _dbus_strerror (errno)); |
| 107 | goto out; |
| 108 | } |
| 109 | |
| 110 | loop = bus_context_get_loop (context); |
| 111 | |
| 112 | watch = _dbus_watch_new (kq, DBUS_WATCH_READABLE, TRUE, |
| 113 | _handle_kqueue_watch, NULL, NULL); |
| 114 | |
| 115 | if (watch == NULL) |
| 116 | { |
| 117 | _dbus_warn ("Unable to create kqueue watch\n"); |
| 118 | close (kq); |
| 119 | kq = -1; |
| 120 | goto out; |
| 121 | } |
| 122 | |
| 123 | if (!_dbus_loop_add_watch (loop, watch, _kqueue_watch_callback, |
| 124 | NULL, NULL)) |
| 125 | { |
| 126 | _dbus_warn ("Unable to add reload watch to main loop"); |
| 127 | close (kq); |
| 128 | kq = -1; |
| 129 | _dbus_watch_unref (watch); |
| 130 | watch = NULL; |
| 131 | goto out; |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | ret = 1; |
| 136 | |
| 137 | out: |
| 138 | return ret; |
| 139 | } |
| 140 | |
| 141 | void |
| 142 | bus_set_watched_dirs (BusContext *context, DBusList **directories) |
| 143 | { |
| 144 | int new_fds[MAX_DIRS_TO_WATCH]; |
| 145 | char *new_dirs[MAX_DIRS_TO_WATCH]; |
| 146 | DBusList *link; |
| 147 | int i, j, f, fd; |
| 148 | struct kevent ev; |
| 149 | |
| 150 | if (!_init_kqueue (context)) |
| 151 | goto out; |
| 152 | |
| 153 | for (i = 0; i < MAX_DIRS_TO_WATCH; i++) |
| 154 | { |
| 155 | new_fds[i] = -1; |
| 156 | new_dirs[i] = NULL; |
| 157 | } |
| 158 | |
| 159 | i = 0; |
| 160 | link = _dbus_list_get_first_link (directories); |
| 161 | while (link != NULL) |
| 162 | { |
| 163 | new_dirs[i++] = (char *)link->data; |
| 164 | link = _dbus_list_get_next_link (directories, link); |
| 165 | } |
| 166 | |
| 167 | /* Look for directories in both the old and new sets, if |
| 168 | * we find one, move its data into the new set. |
| 169 | */ |
| 170 | for (i = 0; new_dirs[i]; i++) |
| 171 | { |
| 172 | for (j = 0; j < num_fds; j++) |
| 173 | { |
| 174 | if (dirs[j] && strcmp (new_dirs[i], dirs[j]) == 0) |
| 175 | { |
| 176 | new_fds[i] = fds[j]; |
| 177 | new_dirs[i] = dirs[j]; |
| 178 | fds[j] = -1; |
| 179 | dirs[j] = NULL; |
| 180 | break; |
| 181 | } |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | /* Any directory we find in "fds" with a nonzero fd must |
| 186 | * not be in the new set, so perform cleanup now. |
| 187 | */ |
| 188 | for (j = 0; j < num_fds; j++) |
| 189 | { |
| 190 | if (fds[j] != -1) |
| 191 | { |
| 192 | close (fds[j]); |
| 193 | dbus_free (dirs[j]); |
| 194 | fds[j] = -1; |
| 195 | dirs[j] = NULL; |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | for (i = 0; new_dirs[i]; i++) |
| 200 | { |
| 201 | if (new_fds[i] == -1) |
| 202 | { |
| 203 | /* FIXME - less lame error handling for failing to add a watch; |
| 204 | * we may need to sleep. |
| 205 | */ |
| 206 | fd = open (new_dirs[i], O_RDONLY); |
| 207 | if (fd < 0) |
| 208 | { |
| 209 | if (errno != ENOENT) |
| 210 | { |
| 211 | _dbus_warn ("Cannot open directory '%s'; error '%s'\n", new_dirs[i], _dbus_strerror (errno)); |
| 212 | goto out; |
| 213 | } |
| 214 | else |
| 215 | { |
| 216 | new_fds[i] = -1; |
| 217 | new_dirs[i] = NULL; |
| 218 | continue; |
| 219 | } |
| 220 | } |
| 221 | |
| 222 | EV_SET (&ev, fd, EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_CLEAR, |
| 223 | NOTE_DELETE | NOTE_EXTEND | NOTE_WRITE | NOTE_RENAME, 0, 0); |
| 224 | if (kevent (kq, &ev, 1, NULL, 0, NULL) == -1) |
| 225 | { |
| 226 | _dbus_warn ("Cannot setup a kevent for '%s'; error '%s'\n", new_dirs[i], _dbus_strerror (errno)); |
| 227 | close (fd); |
| 228 | goto out; |
| 229 | } |
| 230 | |
| 231 | new_fds[i] = fd; |
| 232 | new_dirs[i] = _dbus_strdup (new_dirs[i]); |
| 233 | if (!new_dirs[i]) |
| 234 | { |
| 235 | /* FIXME have less lame handling for OOM, we just silently fail to |
| 236 | * watch. (In reality though, the whole OOM handling in dbus is |
| 237 | * stupid but we won't go into that in this comment =) ) |
| 238 | */ |
| 239 | close (fd); |
| 240 | new_fds[i] = -1; |
| 241 | } |
| 242 | } |
| 243 | } |
| 244 | |
| 245 | num_fds = i; |
| 246 | |
| 247 | for (i = 0; i < MAX_DIRS_TO_WATCH; i++) |
| 248 | { |
| 249 | fds[i] = new_fds[i]; |
| 250 | dirs[i] = new_dirs[i]; |
| 251 | } |
| 252 | |
| 253 | out: |
| 254 | ; |
| 255 | } |