tdb_walk
tdb_walk(rdomain, pfkeyv2_sa_flush,
rval = tdb_walk(rdomain, pfkeyv2_dump_walker, &dump_state);
error = tdb_walk(rdomain, pfkeyv2_sysctl_walker, &w);
SIMPLEQ_INSERT_TAIL(&tdblist, tdbp, tdb_walk);
SIMPLEQ_REMOVE_HEAD(&tdblist, tdb_walk);
SIMPLEQ_ENTRY(tdb) tdb_walk; /* [N] temp list for tdb walker */
int tdb_walk(u_int, int (*)(struct tdb *, void *, int), void *);