HelenOS sources

IEEE80211_FRAME_CTRL_PROTECTED  208 uspace/lib/ieee80211/src/ieee80211.c 	return (frame_ctrl & IEEE80211_FRAME_CTRL_PROTECTED);
IEEE80211_FRAME_CTRL_PROTECTED  595 uspace/lib/ieee80211/src/ieee80211.c 		crypto = uint16_t_le2host(IEEE80211_FRAME_CTRL_PROTECTED);
HelenOS homepage, sources at GitHub