qcmd_add_filter
int qcmd_add_filter(const char *ifname, const char *clname, const char *flname,
error = qcmd_add_filter(ifname, class_name, flname, &sfilt);
ret = qcmd_add_filter(ifname, class_name, flname,
error = qcmd_add_filter(ifname, clname, NULL, &sfilt);
error = qcmd_add_filter(ifname, clname, NULL,