SSL_set_shutdown, SSL_get_shutdown — manipulate shutdown state of an SSL connection
SSL_set_shutdown(SSL *ssl, int mode);
SSL_set_shutdown() sets the shutdown state of ssl to mode.
SSL_get_shutdown() returns the shutdown mode of ssl.
The shutdown state of an ssl connection is a bitmask of:
No shutdown setting, yet.
A "close notify" shutdown alert was sent to the peer, the
connection is being considered closed and the session is closed
A shutdown alert was received form the peer, either a normal
"close notify" or a fatal error.
SSL_SENT_SHUTDOWN and SSL_RECEIVED_SHUTDOWN can be set at
the same time.
The shutdown state of the connection is used to determine
the state of the ssl session. If the session is still open, when SSL_clear(3) or SSL_free(3) is
called, it is considered bad and removed according to RFC2246. The
actual condition for a correctly closed session is SSL_SENT_SHUTDOWN
(according to the TLS RFC, it is acceptable to only send the "close
notify" alert but to not wait for the peer's answer, when the underlying connection
is closed). SSL_set_shutdown() can be used to set this state without
sending a close alert to the peer (see SSL_shutdown(3)).
If a "close notify" was received, SSL_RECEIVED_SHUTDOWN will
be set, for setting SSL_SENT_SHUTDOWN the application must however
still call SSL_shutdown(3) or SSL_set_shutdown() itself.
SSL_set_shutdown() does not return diagnostic information.
SSL_get_shutdown() returns the current setting.
ssl(3), SSL_shutdown(3), SSL_CTX_set_quiet_shutdown(3), SSL_clear(3), SSL_free(3)