GRE_IS_KEY        353 drivers/net/ppp/pptp.c 		!GRE_IS_KEY(header->gre_hd.flags) ||    /* flag KEY should be set */
GRE_IS_KEY        191 tools/testing/selftests/bpf/progs/bpf_flow.c 		if (GRE_IS_KEY(gre->flags))