/*
* TODO: this should be re-written to use the get_config_item("lxc.id_map")
* cmd api instead of getting the idmap from c->lxc_conf. The reason is
* that the id_maps may be different if the container was started with a
* -f or -s argument.
* The reason I'm punting on that is because we'll need to parse the
* idmap results.
*/
static bool cgm_attach(const char *name, const char *lxcpath, pid_t pid)
{
bool pass;
char *cgroup = NULL;
if (!cgm_dbus_connect()) {
ERROR("Error connecting to cgroup manager");
return false;
}
// cgm_create makes sure that we have the same cgroup name for all
// subsystems, so since this is a slow command over the cmd socket,
// just get the cgroup name for the first one.
cgroup = try_get_abs_cgroup(name, lxcpath, subsystems[0]);
if (!cgroup) {
ERROR("Failed to get cgroup for controller %s", subsystems[0]);
cgm_dbus_disconnect();
return false;
}
pass = do_cgm_enter(pid, cgroup, abs_cgroup_supported());
cgm_dbus_disconnect();
if (!pass)
ERROR("Failed to enter group %s", cgroup);
free_abs_cgroup(cgroup);
return pass;
}
static inline void free_abs_cgroup(char *cgroup)
{
if (!cgroup)
return;
if (abs_cgroup_supported())
nih_free(cgroup);
else
free(cgroup);
}
static char *try_get_abs_cgroup(const char *name, const char *lxcpath,
const char *controller)
{
char *cgroup = NULL;
if (abs_cgroup_supported()) {
/* get the container init pid and ask for its abs cgroup */
pid_t pid = lxc_cmd_get_init_pid(name, lxcpath);
if (pid < 0)
return NULL;
if (cgmanager_get_pid_cgroup_abs_sync(NULL, cgroup_manager,
controller, pid, &cgroup) != 0) {
cgroup = NULL;
NihError *nerr;
nerr = nih_error_get();
nih_free(nerr);
}
return cgroup;
}
/* use the command interface to look for the cgroup */
return lxc_cmd_get_cgroup_path(name, lxcpath, controller);
}
static void do_cgm_get(const char *name, const char *lxcpath, const char *filename, int outp, bool sendvalue)
{
char *controller, *key, *cgroup = NULL, *cglast;
int len = -1;
int ret;
nih_local char *result = NULL;
controller = alloca(strlen(filename)+1);
strcpy(controller, filename);
key = strchr(controller, '.');
if (!key) {
ret = write(outp, &len, sizeof(len));
if (ret != sizeof(len))
WARN("Failed to warn cgm_get of error; parent may hang");
exit(1);
}
*key = '\0';
if (!cgm_dbus_connect()) {
ERROR("Error connecting to cgroup manager");
ret = write(outp, &len, sizeof(len));
if (ret != sizeof(len))
WARN("Failed to warn cgm_get of error; parent may hang");
exit(1);
}
cgroup = try_get_abs_cgroup(name, lxcpath, controller);
if (!cgroup) {
cgm_dbus_disconnect();
ret = write(outp, &len, sizeof(len));
if (ret != sizeof(len))
WARN("Failed to warn cgm_get of error; parent may hang");
exit(1);
}
cglast = strrchr(cgroup, '/');
if (!cglast) {
cgm_dbus_disconnect();
free_abs_cgroup(cgroup);
ret = write(outp, &len, sizeof(len));
if (ret != sizeof(len))
WARN("Failed to warn cgm_get of error; parent may hang");
exit(1);
}
*cglast = '\0';
if (!lxc_cgmanager_enter(getpid(), controller, cgroup, abs_cgroup_supported())) {
ERROR("Failed to enter container cgroup %s:%s", controller, cgroup);
ret = write(outp, &len, sizeof(len));
if (ret != sizeof(len))
WARN("Failed to warn cgm_get of error; parent may hang");
cgm_dbus_disconnect();
free_abs_cgroup(cgroup);
exit(1);
}
if (cgmanager_get_value_sync(NULL, cgroup_manager, controller, cglast+1, filename, &result) != 0) {
NihError *nerr;
nerr = nih_error_get();
nih_free(nerr);
free_abs_cgroup(cgroup);
cgm_dbus_disconnect();
ret = write(outp, &len, sizeof(len));
if (ret != sizeof(len))
WARN("Failed to warn cgm_get of error; parent may hang");
exit(1);
}
free_abs_cgroup(cgroup);
cgm_dbus_disconnect();
len = strlen(result);
ret = write(outp, &len, sizeof(len));
if (ret != sizeof(len)) {
WARN("Failed to send length to parent");
exit(1);
}
if (!len || !sendvalue) {
exit(0);
}
ret = write(outp, result, len);
if (ret < 0)
exit(1);
exit(0);
}
static void do_cgm_set(const char *name, const char *lxcpath, const char *filename, const char *value, int outp)
{
char *controller, *key, *cgroup = NULL;
int retval = 0; // value we are sending to the parent over outp
int ret;
char *cglast;
controller = alloca(strlen(filename)+1);
strcpy(controller, filename);
key = strchr(controller, '.');
if (!key) {
ret = write(outp, &retval, sizeof(retval));
if (ret != sizeof(retval))
WARN("Failed to warn cgm_set of error; parent may hang");
exit(1);
}
*key = '\0';
if (!cgm_dbus_connect()) {
ERROR("Error connecting to cgroup manager");
ret = write(outp, &retval, sizeof(retval));
if (ret != sizeof(retval))
WARN("Failed to warn cgm_set of error; parent may hang");
exit(1);
}
cgroup = try_get_abs_cgroup(name, lxcpath, controller);
if (!cgroup) {
cgm_dbus_disconnect();
ret = write(outp, &retval, sizeof(retval));
if (ret != sizeof(retval))
WARN("Failed to warn cgm_set of error; parent may hang");
exit(1);
}
cglast = strrchr(cgroup, '/');
if (!cglast) {
cgm_dbus_disconnect();
free_abs_cgroup(cgroup);
ret = write(outp, &retval, sizeof(retval));
if (ret != sizeof(retval))
WARN("Failed to warn cgm_set of error; parent may hang");
exit(1);
}
*cglast = '\0';
if (!lxc_cgmanager_enter(getpid(), controller, cgroup, abs_cgroup_supported())) {
ERROR("Failed to enter container cgroup %s:%s", controller, cgroup);
ret = write(outp, &retval, sizeof(retval));
if (ret != sizeof(retval))
WARN("Failed to warn cgm_set of error; parent may hang");
cgm_dbus_disconnect();
free_abs_cgroup(cgroup);
exit(1);
}
if (cgmanager_set_value_sync(NULL, cgroup_manager, controller, cglast+1, filename, value) != 0) {
NihError *nerr;
nerr = nih_error_get();
ERROR("Error setting cgroup value %s for %s:%s", filename, controller, cgroup);
ERROR("call to cgmanager_set_value_sync failed: %s", nerr->message);
nih_free(nerr);
free_abs_cgroup(cgroup);
cgm_dbus_disconnect();
ret = write(outp, &retval, sizeof(retval));
if (ret != sizeof(retval))
WARN("Failed to warn cgm_set of error; parent may hang");
exit(1);
}
free_abs_cgroup(cgroup);
cgm_dbus_disconnect();
/* tell parent that we are done */
retval = 1;
ret = write(outp, &retval, sizeof(retval));
if (ret != sizeof(retval)) {
exit(1);
}
exit(0);
}