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/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-
*
* Copyright (C) 2007 David Zeuthen <david@fubar.dk>
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include "devkit-disks-poller.h"
#include "devkit-disks-device.h"
#include "devkit-disks-device-private.h"
#ifdef __linux__
extern char **environ;
static char **argv_buffer = NULL;
static size_t argv_size = 0;
#endif
static void
set_proc_title_init (int argc, char *argv[])
{
#ifdef __linux__
unsigned int i;
char **new_environ, *endptr;
/* This code is really really ugly. We make some memory layout
* assumptions and reuse the environment array as memory to store
* our process title in */
for (i = 0; environ[i] != NULL; i++)
;
endptr = i ? environ[i-1] + strlen (environ[i-1]) : argv[argc-1] + strlen (argv[argc-1]);
argv_buffer = argv;
argv_size = endptr - argv_buffer[0];
/* Make a copy of environ */
new_environ = malloc (sizeof(char*) * (i + 1));
for (i = 0; environ[i] != NULL; i++)
new_environ[i] = strdup (environ[i]);
new_environ[i] = NULL;
environ = new_environ;
#endif
}
/* this code borrowed from avahi-daemon's setproctitle.c (LGPL v2) */
static void
set_proc_title (const char *format, ...)
{
#ifdef __linux__
size_t len;
va_list ap;
if (argv_buffer == NULL)
goto out;
va_start (ap, format);
vsnprintf (argv_buffer[0], argv_size, format, ap);
va_end (ap);
len = strlen (argv_buffer[0]);
memset (argv_buffer[0] + len, 0, argv_size - len);
argv_buffer[1] = NULL;
out:
;
#endif
}
static gchar **poller_devices_to_poll = NULL;
static guint poller_timeout_id = 0;
void
devkit_disks_poller_poll_device (const gchar *device_file)
{
gboolean is_cdrom;
int fd;
/* the device file is the canonical device file from udev */
is_cdrom = (g_str_has_prefix (device_file, "/dev/sr") || g_str_has_prefix (device_file, "/dev/scd"));
//g_debug ("polling '%s'", device_file);
if (is_cdrom) {
/* optical drives need special care
*
* - use O_NONBLOCK to avoid closing the door
* - use O_EXCL to avoid interferring with cd burning software / audio playback / etc
*/
fd = open (device_file, O_RDONLY | O_NONBLOCK | O_EXCL);
if (fd != -1) {
close (fd);
}
} else {
fd = open (device_file, O_RDONLY);
if (fd != -1) {
close (fd);
}
}
}
static gboolean
poller_timeout_cb (gpointer user_data)
{
guint n;
for (n = 0; poller_devices_to_poll != NULL && poller_devices_to_poll[n] != NULL; n++) {
const gchar *device_file = poller_devices_to_poll[n];
devkit_disks_poller_poll_device (device_file);
}
/* don't remove the source */
return TRUE;
}
static gboolean
poller_have_data (GIOChannel *channel,
GIOCondition condition,
gpointer user_data)
{
gchar *line;
gsize line_length;
GError *error;
gint status;
error = NULL;
/* Exit if parent dies */
if (condition == G_IO_HUP) {
exit (1);
}
again:
status = g_io_channel_read_line (channel,
&line,
&line_length,
NULL,
&error);
if (error != NULL) {
g_warning ("Error reading line from daemon: %s", error->message);
g_error_free (error);
goto out;
}
if (status == G_IO_STATUS_AGAIN) {
goto again;
}
//g_debug ("polling process read '%s'", line);
if (line[line_length - 1] == '\n')
line[line_length - 1] = '\0';
if (line[line_length - 2] == ' ')
line[line_length - 2] = '\0';
g_strfreev (poller_devices_to_poll);
poller_devices_to_poll = g_strsplit (line, " ", 0);
if (g_strv_length (poller_devices_to_poll) == 0) {
if (poller_timeout_id > 0) {
g_source_remove (poller_timeout_id);
poller_timeout_id = 0;
}
set_proc_title ("devkit-disks-daemon: not polling any devices");
} else {
set_proc_title ("devkit-disks-daemon: polling %s", line);
if (poller_timeout_id == 0) {
poller_timeout_id = g_timeout_add_seconds (2, poller_timeout_cb, NULL);
}
}
g_free (line);
out:
/* keep the IOChannel around */
return TRUE;
}
static void
poller_run (gint fd)
{
GMainLoop *loop;
GIOChannel *io_channel;
loop = g_main_loop_new (NULL, FALSE);
io_channel = g_io_channel_unix_new (fd);
g_io_channel_set_flags (io_channel, G_IO_FLAG_NONBLOCK, NULL);
g_io_add_watch (io_channel, G_IO_IN | G_IO_HUP, poller_have_data, NULL);
g_main_loop_run (loop);
}
/* ---------------------------------------------------------------------------------------------------- */
static gint poller_daemon_write_end_fd;
gboolean
devkit_disks_poller_setup (int argc, char *argv[])
{
gint pipefds[2];
gboolean ret;
ret = FALSE;
if (pipe (pipefds) != 0) {
g_warning ("Couldn't set up polling process, pipe() failed: %m");
goto out;
}
switch (fork ()) {
case 0:
/* child */
close (pipefds[1]); /* close write end */
set_proc_title_init (argc, argv);
poller_run (pipefds[0]);
break;
default:
/* parent */
close (pipefds[0]); /* close read end */
poller_daemon_write_end_fd = pipefds[1];
break;
case -1:
g_warning ("Couldn't set up polling process, fork() failed: %m");
goto out;
break;
}
ret = TRUE;
out:
return ret;
}
void
devkit_disks_poller_set_devices (GList *devices)
{
GList *l;
gchar **device_array;
guint n;
gchar *devices_to_poll;
static gchar *devices_currently_polled = NULL;
device_array = g_new0 (gchar *, g_list_length (devices) + 2);
for (l = devices, n = 0; l != NULL; l = l->next) {
DevkitDisksDevice *device = DEVKIT_DISKS_DEVICE (l->data);
device_array[n++] = device->priv->device_file;
}
g_qsort_with_data (device_array, n, sizeof (gchar *), (GCompareDataFunc) g_strcmp0, NULL);
device_array[n] = "\n";
devices_to_poll = g_strjoinv (" ", device_array);
g_free (device_array);
/* only poke the polling process if the list of currently polled devices change */
if (g_strcmp0 (devices_to_poll, devices_currently_polled) != 0) {
g_free (devices_currently_polled);
devices_currently_polled = devices_to_poll;
write (poller_daemon_write_end_fd, devices_currently_polled, strlen (devices_currently_polled));
//g_debug ("Wanna poll: '%s'", devices_currently_polled);
} else {
g_free (devices_to_poll);
}
}
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