1: =pod
    2: 
    3: =head1 NAME
    4: 
    5: SSL_set_shutdown, SSL_get_shutdown - manipulate shutdown state of an SSL connection
    6: 
    7: =head1 SYNOPSIS
    8: 
    9:  #include <openssl/ssl.h>
   10: 
   11:  void SSL_set_shutdown(SSL *ssl, int mode);
   12: 
   13:  int SSL_get_shutdown(const SSL *ssl);
   14: 
   15: =head1 DESCRIPTION
   16: 
   17: SSL_set_shutdown() sets the shutdown state of B<ssl> to B<mode>.
   18: 
   19: SSL_get_shutdown() returns the shutdown mode of B<ssl>.
   20: 
   21: =head1 NOTES
   22: 
   23: The shutdown state of an ssl connection is a bitmask of:
   24: 
   25: =over 4
   26: 
   27: =item 0
   28: 
   29: No shutdown setting, yet.
   30: 
   31: =item SSL_SENT_SHUTDOWN
   32: 
   33: A "close notify" shutdown alert was sent to the peer, the connection is being
   34: considered closed and the session is closed and correct.
   35: 
   36: =item SSL_RECEIVED_SHUTDOWN
   37: 
   38: A shutdown alert was received form the peer, either a normal "close notify"
   39: or a fatal error.
   40: 
   41: =back
   42: 
   43: SSL_SENT_SHUTDOWN and SSL_RECEIVED_SHUTDOWN can be set at the same time.
   44: 
   45: The shutdown state of the connection is used to determine the state of
   46: the ssl session. If the session is still open, when
   47: L<SSL_clear(3)|SSL_clear(3)> or L<SSL_free(3)|SSL_free(3)> is called,
   48: it is considered bad and removed according to RFC2246.
   49: The actual condition for a correctly closed session is SSL_SENT_SHUTDOWN
   50: (according to the TLS RFC, it is acceptable to only send the "close notify"
   51: alert but to not wait for the peer's answer, when the underlying connection
   52: is closed).
   53: SSL_set_shutdown() can be used to set this state without sending a
   54: close alert to the peer (see L<SSL_shutdown(3)|SSL_shutdown(3)>).
   55: 
   56: If a "close notify" was received, SSL_RECEIVED_SHUTDOWN will be set,
   57: for setting SSL_SENT_SHUTDOWN the application must however still call
   58: L<SSL_shutdown(3)|SSL_shutdown(3)> or SSL_set_shutdown() itself.
   59: 
   60: =head1 RETURN VALUES
   61: 
   62: SSL_set_shutdown() does not return diagnostic information.
   63: 
   64: SSL_get_shutdown() returns the current setting.
   65: 
   66: =head1 SEE ALSO
   67: 
   68: L<ssl(3)|ssl(3)>, L<SSL_shutdown(3)|SSL_shutdown(3)>,
   69: L<SSL_CTX_set_quiet_shutdown(3)|SSL_CTX_set_quiet_shutdown(3)>,
   70: L<SSL_clear(3)|SSL_clear(3)>, L<SSL_free(3)|SSL_free(3)>
   71: 
   72: =cut