/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ /* dir-watch-kqueue.c OS specific directory change notification for message bus * * Copyright (C) 2003 Red Hat, Inc. * * 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 #include #include #include #include #include #include #ifdef HAVE_ERRNO_H #include #endif #include "bus.h" #include #include #include #include "dir-watch.h" #define MAX_DIRS_TO_WATCH 128 static int kq = -1; static int fds[MAX_DIRS_TO_WATCH]; static char *dirs[MAX_DIRS_TO_WATCH]; static int num_fds = 0; static DBusWatch *watch = NULL; static DBusLoop *loop = NULL; static dbus_bool_t _handle_kqueue_watch (DBusWatch *watch, unsigned int flags, void *data) { struct kevent ev; struct timespec nullts = { 0, 0 }; int res; pid_t pid; res = kevent (kq, NULL, 0, &ev, 1, &nullts); /* Sleep for half a second to avoid a race when files are install(1)'d * to system.d. */ usleep(500000); if (res > 0) { pid = getpid (); _dbus_verbose ("Sending SIGHUP signal on reception of a kevent\n"); (void) kill (pid, SIGHUP); } else if (res < 0 && errno == EBADF) { kq = -1; if (watch != NULL) { _dbus_loop_remove_watch (loop, watch); _dbus_watch_invalidate (watch); _dbus_watch_unref (watch); watch = NULL; } pid = getpid (); _dbus_verbose ("Sending SIGHUP signal since kqueue has been closed\n"); (void) kill (pid, SIGHUP); } return TRUE; } static void _shutdown_kqueue (void *data) { int i; if (kq < 0) return; for (i = 0; i < MAX_DIRS_TO_WATCH; i++) { if (fds[i] >= 0) { close (fds[i]); fds[i] = -1; } if (dirs[i] != NULL) { /* dbus_free() is necessary to pass memleak check */ dbus_free (dirs[i]); dirs[i] = NULL; } } if (loop) { _dbus_loop_remove_watch (loop, watch); _dbus_loop_unref (loop); loop = NULL; } if (watch) { _dbus_watch_invalidate (watch); _dbus_watch_unref (watch); watch = NULL; } close (kq); kq = -1; } static int _init_kqueue (BusContext *context) { if (kq < 0) { kq = kqueue (); if (kq < 0) { _dbus_warn ("Cannot create kqueue; error '%s'\n", _dbus_strerror (errno)); goto out; } loop = bus_context_get_loop (context); _dbus_loop_ref (loop); watch = _dbus_watch_new (kq, DBUS_WATCH_READABLE, TRUE, _handle_kqueue_watch, NULL, NULL); if (watch == NULL) { _dbus_warn ("Unable to create kqueue watch\n"); goto out1; } if (!_dbus_loop_add_watch (loop, watch)) { _dbus_warn ("Unable to add reload watch to main loop"); goto out2; } if (!_dbus_register_shutdown_func (_shutdown_kqueue, NULL)) { _dbus_warn ("Unable to register shutdown function"); goto out3; } } return 1; out3: _dbus_loop_remove_watch (loop, watch); out2: if (watch) { _dbus_watch_invalidate (watch); _dbus_watch_unref (watch); watch = NULL; } out1: if (kq >= 0) { close (kq); kq = -1; } if (loop) { _dbus_loop_unref (loop); loop = NULL; } out: return 0; } void bus_set_watched_dirs (BusContext *context, DBusList **directories) { int new_fds[MAX_DIRS_TO_WATCH]; char *new_dirs[MAX_DIRS_TO_WATCH]; DBusList *link; int i, j, fd; struct kevent ev; if (!_init_kqueue (context)) goto out; for (i = 0; i < MAX_DIRS_TO_WATCH; i++) { new_fds[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_fds; j++) { if (dirs[j] && strcmp (new_dirs[i], dirs[j]) == 0) { new_fds[i] = fds[j]; new_dirs[i] = dirs[j]; fds[j] = -1; dirs[j] = NULL; break; } } } /* Any directory we find in "fds" with a nonzero fd must * not be in the new set, so perform cleanup now. */ for (j = 0; j < num_fds; j++) { if (fds[j] != -1) { close (fds[j]); dbus_free (dirs[j]); fds[j] = -1; dirs[j] = NULL; } } for (i = 0; new_dirs[i]; i++) { if (new_fds[i] == -1) { /* FIXME - less lame error handling for failing to add a watch; * we may need to sleep. */ fd = open (new_dirs[i], O_RDONLY | O_CLOEXEC); if (fd < 0) { if (errno != ENOENT) { _dbus_warn ("Cannot open directory '%s'; error '%s'\n", new_dirs[i], _dbus_strerror (errno)); goto out; } else { new_fds[i] = -1; new_dirs[i] = NULL; continue; } } EV_SET (&ev, fd, EVFILT_VNODE, EV_ADD | EV_ENABLE | EV_CLEAR, NOTE_DELETE | NOTE_EXTEND | NOTE_WRITE | NOTE_RENAME, 0, 0); if (kevent (kq, &ev, 1, NULL, 0, NULL) == -1) { _dbus_warn ("Cannot setup a kevent for '%s'; error '%s'\n", new_dirs[i], _dbus_strerror (errno)); close (fd); goto out; } new_fds[i] = fd; 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 =) ) */ close (fd); new_fds[i] = -1; } } } num_fds = i; for (i = 0; i < MAX_DIRS_TO_WATCH; i++) { fds[i] = new_fds[i]; dirs[i] = new_dirs[i]; } out: ; }