- update-policy {
- /*
- * A rather long description here, as the "ms-self" option does
- * not appear in any docs yet (it can only be found in the
- * source code).
- *
- * The short of it is that each host is allowed to update its
- * own A and AAAA records, when the update request is properly
- * signed by the host itself.
- *
- * The long description is (look at the
- * dst_gssapi_identitymatchesrealmms() call in lib/dns/ssu.c and
- * its definition in lib/dns/gssapictx.c for details):
- *
- * A GSS-TSIG update request will be signed by a given signer
- * (e.g. machine-name$@${REALM}). The signer name is split into
- * the machine component (e.g. "machine-name") and the realm
- * component (e.g. "${REALM}"). The update is allowed if the
- * following conditions are met:
- *
- * 1) The machine component of the signer name matches the first
- * (host) component of the FQDN that is being updated.
- *
- * 2) The realm component of the signer name matches the realm
- * in the grant statement below (${REALM}).
- *
- * 3) The domain component of the FQDN that is being updated
- * matches the realm in the grant statement below.
- *
- * If the 3 conditions above are satisfied, the update succeeds.
- */
- grant ${REALM} ms-self * A AAAA;
- };