HelenOS sources

OF_FLAG_M         250 uspace/srv/net/inetsrv/pdu.c 	    (rem_offs < packet->size ? BIT_V(uint16_t, OF_FLAG_M) : 0) +
OF_FLAG_M         454 uspace/srv/net/inetsrv/pdu.c 	packet->mf = (offsmf & BIT_V(uint16_t, OF_FLAG_M)) != 0;
HelenOS homepage, sources at GitHub