1=pod 2 3=head1 NAME 4 5SSL_CTX_set_new_pending_conn_cb, SSL_set_new_pending_conn_cb_fn - callback function to report creation of QUIC connection SSL objects 6 7=head1 SYNOPSIS 8 9 typedef int (*SSL_set_new_pending_conn_cb_fn)(SSL_CTX *c, SSL *new_ssl, 10 void *arg); 11 void SSL_CTX_set_new_pending_conn_cb(SSL_CTX *c, 12 SSL_set_new_pending_conn_cb_fn *f, 13 void *arg); 14 15=head1 DESCRIPTION 16 17SSL_CTX_set_new_pending_conn_cb() sets the new_pending_conn callback function and 18associated application data argument I<arg>. When using the QUIC transport, TLS 19handshake processing may occur independently from the thread which accepts the 20connection that the handshake is establishing. As such, B<SSL> objects 21representing the connection may be allocated and initialized prior to a call to 22SSL_accept_connection(). This registered callback may be used to decorate the 23preallocated B<SSL> object or create other associations with its parent 24B<SSL> prior to a call to SSL_accept_connection(). 25 26=head1 RETURN VALUES 27 28SSL_CTX_set_new_pending_conn_cb() returns no value. 29 30SSL_set_new_pending_conn_cb_fn() returns an integer value. A return value of 310 indicates that the QUIC stack must discard this newly created B<SSL> object, 32implying that the associated new connection will not be available for handling 33on a subsequent call to SSL_accept_connection(). A nonzero return 34value is treated as success, allowing the new connection to be enqueued to the 35accept queue. 36 37=head1 SEE ALSO 38 39L<SSL_set_ex_data(3)> 40 41=head1 NOTES 42 43Callbacks in QUIC connections have some limitations to them that should be taken 44into consideration when writing an application. 45 46=over 4 47 48QUIC connections may begin processing prior to when an application calls 49SSL_accept_connection() on them. As such, it may occur that callbacks are 50delivered to applications' registered TLS callbacks prior to those SSL objects 51being returned in SSL_accept_connection(). Applications should expect this 52possibility. 53 54In particular no references should be held on SSL objects passed to callbacks 55for QUIC connections until such time as they are returned through a call to 56SSL_accept_connection. 57 58=back 59 60=head1 HISTORY 61 62SSL_CTX_set_new_pending_conn_cb() was added in OpenSSL 3.5 63 64=head1 COPYRIGHT 65 66Copyright 2025 The OpenSSL Project Authors. All Rights Reserved. 67 68Licensed under the Apache License 2.0 (the "License"). You may not use 69this file except in compliance with the License. You can obtain a copy 70in the file LICENSE in the source distribution or at 71L<https://www.openssl.org/source/license.html>. 72 73=cut 74