+static int socket_kill(Unit *u, KillWho who, KillMode mode, int signo, DBusError *error) {
+ Socket *s = SOCKET(u);
+ int r = 0;
+ Set *pid_set = NULL;
+
+ assert(s);
+
+ if (who == KILL_MAIN) {
+ dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "Socket units have no main processes");
+ return -EINVAL;
+ }
+
+ if (s->control_pid <= 0 && who == KILL_CONTROL) {
+ dbus_set_error(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
+ return -ENOENT;
+ }
+
+ if (s->control_pid > 0)
+ if (kill(s->control_pid, signo) < 0)
+ r = -errno;
+
+ if (mode == KILL_CONTROL_GROUP) {
+ int q;
+
+ if (!(pid_set = set_new(trivial_hash_func, trivial_compare_func)))
+ return -ENOMEM;
+
+ /* Exclude the control pid from being killed via the cgroup */
+ if (s->control_pid > 0)
+ if ((q = set_put(pid_set, LONG_TO_PTR(s->control_pid))) < 0) {
+ r = q;
+ goto finish;
+ }
+
+ if ((q = cgroup_bonding_kill_list(s->meta.cgroup_bondings, signo, false, pid_set)) < 0)
+ if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
+ r = q;
+ }
+
+finish:
+ if (pid_set)
+ set_free(pid_set);
+
+ return r;
+}
+