musl/include/bits/ipc.h

#define IPC_CREAT  01000
#define IPC_EXCL   02000
#define IPC_NOWAIT 04000

#define IPC_RMID 0
#define IPC_SET  1
#define IPC_STAT 2

#define IPC_PRIVATE ((key_t) 0)

struct ipc_perm
{
	key_t key;
	uid_t uid;
	gid_t gid;
	uid_t cuid;
	gid_t cgid;
	mode_t mode;
	int seq;
	long __pad1;
	long __pad2;
};