NAME

       SSL_set_incoming_stream_policy, SSL_INCOMING_STREAM_POLICY_AUTO, SSL_INCOMING_STREAM_POLICY_ACCEPT,
       SSL_INCOMING_STREAM_POLICY_REJECT - manage the QUIC incoming stream policy

SYNOPSIS

        #include <openssl/ssl.h>

        #define SSL_INCOMING_STREAM_POLICY_AUTO
        #define SSL_INCOMING_STREAM_POLICY_ACCEPT
        #define SSL_INCOMING_STREAM_POLICY_REJECT

        int SSL_set_incoming_stream_policy(SSL *conn, int policy,
                                                  uint64_t app_error_code);

DESCRIPTION

       SSL_set_incoming_stream_policy() policy changes the incoming stream policy for a QUIC connection.
       Depending on the policy configured, OpenSSL QUIC may automatically reject incoming streams initiated by
       the peer. This is intended to ensure that legacy applications using single-stream operation with a
       default stream on a QUIC connection SSL object are not passed remotely-initiated streams by a peer which
       those applications are not prepared to handle.

       app_error_code is an application error code which will be used in any QUIC STOP_SENDING or RESET_STREAM
       frames generated to implement the policy. The default application error code is 0.

       The valid values for policy are:

       SSL_INCOMING_STREAM_POLICY_AUTO
           This is the default setting. Incoming streams are accepted according to the following rules:

           •   If   the  default  stream  mode  (configured  using  SSL_set_default_stream_mode(3))  is  set  to
               SSL_DEFAULT_STREAM_MODE_AUTO_BIDI (the default) or SSL_DEFAULT_STREAM_MODE_AUTO_UNI, the incoming
               stream is rejected.

           •   Otherwise (where the default stream mode is  SSL_DEFAULT_STREAM_MODE_NONE),  the  application  is
               assumed to be stream aware, and the incoming stream is accepted.

       SSL_INCOMING_STREAM_POLICY_ACCEPT
           Always accept incoming streams, allowing them to be dequeued using SSL_accept_stream(3).

       SSL_INCOMING_STREAM_POLICY_REJECT
           Always reject incoming streams.

       Where an incoming stream is rejected, it is rejected immediately and it is not possible to gain access to
       the  stream  using  SSL_accept_stream(3). The stream is rejected using QUIC STOP_SENDING and RESET_STREAM
       frames as appropriate.

RETURN VALUES

       Returns 1 on success and 0 on failure.

       This function fails if called on a QUIC stream SSL object, or on a non-QUIC SSL object.

SEE ALSO

       SSL_set_default_stream_mode(3), SSL_accept_stream(3)

HISTORY

       SSL_set_incoming_stream_policy() was added in OpenSSL 3.2.

COPYRIGHT

       Copyright 2002-2023 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
       <https://www.openssl.org/source/license.html>.

3.4.1                                              2025-04-03               SSL_SET_INCOMING_STREAM_POLICY(3SSL)