=pod

=head1 NAME

DTLSv1_get_timeout - determine when a DTLS or QUIC SSL object next needs a
timeout event to be handled

=head1 SYNOPSIS

 #include <openssl/ssl.h>

 int DTLSv1_get_timeout(SSL *s, struct timeval *tv);

=head1 DESCRIPTION

DTLSv1_get_timeout() can be used on a DTLS or QUIC SSL object to determine when
the SSL object next needs to perform internal processing due to the passage of
time.

Calling DTLSv1_get_timeout() results in I<*tv> being written with an amount of
time left before the SSL object needs have DTLSv1_handle_timeout() called on it.
If the SSL object needs to be ticked immediately, I<*tv> is zeroed and the
function succeeds, returning 1. If no timeout is currently active, this function
returns 0.

This function is only applicable to DTLS and QUIC objects. It fails if called on
any other kind of SSL object.

Note that the value output by a call to DTLSv1_get_timeout() may change as a
result of other calls to the SSL object.

Once the timeout expires, DTLSv1_handle_timeout() should be called to handle any
internal processing which is due; for more information, see
L<DTLSv1_handle_timeout(3)>.

L<SSL_get_event_timeout(3)> supersedes all use cases for this this function and
may be used instead of it.

=head1 RETURN VALUES

On success, writes a duration to I<*tv> and returns 1.

Returns 0 on failure, or if no timeout is currently active.

=head1 SEE ALSO

L<DTLSv1_handle_timeout(3)>, L<SSL_get_event_timeout(3)>, L<ssl(7)>

=head1 COPYRIGHT

Copyright 2023 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.

=cut
