/*
* We may decide to make the socket path customizable. For now
* just assume it is in /sys/fs/cgroup/ which has some special
* consequences
*/
static bool setup_cgroup_dir(void)
{
int ret;
if (!dir_exists(CGDIR)) {
nih_debug(CGDIR " does not exist");
return false;
}
if (daemon_running()) {
nih_error("%s: cgmanager is already running", __func__);
return false;
}
if (file_exists(CGMANAGER_SOCK)) {
if (unlink(CGMANAGER_SOCK) < 0) {
nih_error("%s: failed to delete stale cgmanager socket", __func__);
return false;
}
}
/* Check that /sys/fs/cgroup is writeable, else mount a tmpfs */
unlink(CGPROBE);
ret = creat(CGPROBE, O_RDWR);
if (ret >= 0) {
close(ret);
unlink(CGPROBE);
return mkdir_cgmanager_dir();
}
ret = mount("cgroup", CGDIR, "tmpfs", 0, "size=10000");
if (ret) {
nih_debug("Failed to mount tmpfs on %s: %s",
CGDIR, strerror(errno));
return false;
}
nih_debug("Mounted tmpfs onto %s", CGDIR);
return mkdir_cgmanager_dir();
}
/**
* make_safe_string:
* @parent: parent,
* @original: original string.
*
* Strip non-printable and non-blank bytes from specified string.
*
* Notes:
*
* Sadly, this is necessary as some hardware (such as battery devices)
* exposes non-printable bytes in their descriptive registers to the
* kernel. Since neither the kernel nor udev specify any encoding for
* udev messages, these (probably bogus) bytes get passed up to userland
* to deal with. This is sub-optimal since it implies that _every_
* application that processes udev messages must perform its own
* sanitizing on the messages. Let's just hope they all deal with the
* problem in the same way...
*
* Note that *iff* the kernel/udev did specify an encoding model, this
* problem could go away since one of the lower layers could then
* detect the out-of-bound data and deal with it at source. All instances
* of this issue seen so far seem to indicate the binary control data
* being presented by the hardware is in fact bogus ("corruption") and
* looks like some block of memory has not been initialized correctly.
*
* The approach taken here is to simulate the approach already adopted
* by 'upower' (up_device_supply_make_safe_string()), with the exception
* that we also allow blank characters (such as tabs).
*
* Returns a copy of @original stripped of all non-printable and
* non-blank characters, or NULL if insufficient memory.
**/
char *
make_safe_string (const void *parent, const char *original)
{
size_t len;
size_t i, j;
char *cleaned;
nih_assert (original);
len = strlen (original);
cleaned = nih_alloc (parent, len + 1);
if (! cleaned)
return NULL;
for (i=0, j=0; i < len; ) {
/* Skip over bogus bytes */
if (! (isprint (original[i]) || isblank (original[i]))) {
i++;
continue;
}
/* Copy what remains */
cleaned[j] = original[i];
i++; j++;
}
/* Terminate */
cleaned[j] = '\0';
if (i != j)
nih_debug ("removed unexpected bytes from udev message data");
/* Note that strictly we should realloc the string if
* bogus bytes were found (since it will now be shorter).
* However, since all the strings are short (and short-lived) we
* do not do this to avoid the associated overhead.
*/
return cleaned;
}
static void
udev_monitor_watcher (struct udev_monitor *udev_monitor,
NihIoWatch * watch,
NihIoEvents events)
{
struct udev_device * udev_device;
nih_local char * subsystem = NULL;
nih_local char * action = NULL;
nih_local char * kernel = NULL;
nih_local char * devpath = NULL;
nih_local char * devname = NULL;
nih_local char * name = NULL;
nih_local char ** env = NULL;
const char * value = NULL;
size_t env_len = 0;
DBusPendingCall * pending_call;
char *(*copy_string)(const void *, const char *) = NULL;
udev_device = udev_monitor_receive_device (udev_monitor);
if (! udev_device)
return;
copy_string = no_strip_udev_data ? nih_strdup : make_safe_string;
value = udev_device_get_subsystem (udev_device);
subsystem = value ? copy_string (NULL, value) : NULL;
value = udev_device_get_action (udev_device);
action = value ? copy_string (NULL, value) : NULL;
value = udev_device_get_sysname (udev_device);
kernel = value ? copy_string (NULL, value) : NULL;
value = udev_device_get_devpath (udev_device);
devpath = value ? copy_string (NULL, value) : NULL;
value = udev_device_get_devnode (udev_device);
devname = value ? copy_string (NULL, value) : NULL;
/* Protect against the "impossible" */
if (! action)
goto out;
if (! strcmp (action, "add")) {
name = NIH_MUST (nih_sprintf (NULL, "%s-device-added",
subsystem));
} else if (! strcmp (action, "change")) {
name = NIH_MUST (nih_sprintf (NULL, "%s-device-changed",
subsystem));
} else if (! strcmp (action, "remove")) {
name = NIH_MUST (nih_sprintf (NULL, "%s-device-removed",
subsystem));
} else {
name = NIH_MUST (nih_sprintf (NULL, "%s-device-%s",
subsystem, action));
}
env = NIH_MUST (nih_str_array_new (NULL));
if (kernel) {
nih_local char *var = NULL;
var = NIH_MUST (nih_sprintf (NULL, "KERNEL=%s", kernel));
NIH_MUST (nih_str_array_addp (&env, NULL, &env_len, var));
}
if (devpath) {
nih_local char *var = NULL;
var = NIH_MUST (nih_sprintf (NULL, "DEVPATH=%s", devpath));
NIH_MUST (nih_str_array_addp (&env, NULL, &env_len, var));
}
if (devname) {
nih_local char *var = NULL;
var = NIH_MUST (nih_sprintf (NULL, "DEVNAME=%s", devname));
NIH_MUST (nih_str_array_addp (&env, NULL, &env_len, var));
}
if (subsystem) {
nih_local char *var = NULL;
var = NIH_MUST (nih_sprintf (NULL, "SUBSYSTEM=%s", subsystem));
NIH_MUST (nih_str_array_addp (&env, NULL, &env_len, var));
}
if (action) {
nih_local char *var = NULL;
var = NIH_MUST (nih_sprintf (NULL, "ACTION=%s", action));
NIH_MUST (nih_str_array_addp (&env, NULL, &env_len, var));
}
for (struct udev_list_entry *list_entry = udev_device_get_properties_list_entry (udev_device);
list_entry != NULL;
list_entry = udev_list_entry_get_next (list_entry)) {
nih_local char *udev_name = NULL;
nih_local char *udev_value = NULL;
nih_local char *var = NULL;
udev_name = copy_string (NULL, udev_list_entry_get_name (list_entry));
if (! strcmp (udev_name, "DEVPATH"))
continue;
if (! strcmp (udev_name, "DEVNAME"))
continue;
if (! strcmp (udev_name, "SUBSYSTEM"))
continue;
if (! strcmp (udev_name, "ACTION"))
continue;
udev_value = copy_string (NULL, udev_list_entry_get_value (list_entry));
var = NIH_MUST (nih_sprintf (NULL, "%s=%s", udev_name, udev_value));
NIH_MUST (nih_str_array_addp (&env, NULL, &env_len, var));
}
nih_debug ("%s %s", name, devname ? devname : "");
pending_call = upstart_emit_event (upstart,
name, env, FALSE,
NULL, emit_event_error, NULL,
NIH_DBUS_TIMEOUT_NEVER);
if (! pending_call) {
NihError *err;
int saved = errno;
err = nih_error_get ();
nih_warn ("%s", err->message);
if (saved != ENOMEM && subsystem)
nih_warn ("Likely that udev '%s' event contains binary garbage", subsystem);
nih_free (err);
}
dbus_pending_call_unref (pending_call);
out:
udev_device_unref (udev_device);
}