1=pod 2 3=head1 NAME 4 5SSL_waiting_for_async, 6SSL_get_all_async_fds, 7SSL_get_changed_async_fds 8- manage asynchronous operations 9 10=head1 SYNOPSIS 11 12=for openssl multiple includes 13 14 #include <openssl/async.h> 15 #include <openssl/ssl.h> 16 17 int SSL_waiting_for_async(SSL *s); 18 int SSL_get_all_async_fds(SSL *s, OSSL_ASYNC_FD *fd, size_t *numfds); 19 int SSL_get_changed_async_fds(SSL *s, OSSL_ASYNC_FD *addfd, size_t *numaddfds, 20 OSSL_ASYNC_FD *delfd, size_t *numdelfds); 21 22=head1 DESCRIPTION 23 24SSL_waiting_for_async() determines whether an SSL connection is currently 25waiting for asynchronous operations to complete (see the B<SSL_MODE_ASYNC> mode 26in L<SSL_CTX_set_mode(3)>). 27 28SSL_get_all_async_fds() returns a list of file descriptor which can be used in a 29call to select() or poll() to determine whether the current asynchronous 30operation has completed or not. A completed operation will result in data 31appearing as "read ready" on the file descriptor (no actual data should be read 32from the file descriptor). This function should only be called if the B<SSL> 33object is currently waiting for asynchronous work to complete (i.e. 34B<SSL_ERROR_WANT_ASYNC> has been received - see L<SSL_get_error(3)>). Typically 35the list will only contain one file descriptor. However, if multiple asynchronous 36capable engines are in use then more than one is possible. The number of file 37descriptors returned is stored in I<*numfds> and the file descriptors themselves 38are in I<*fds>. The I<fds> parameter may be NULL in which case no file 39descriptors are returned but I<*numfds> is still populated. It is the callers 40responsibility to ensure sufficient memory is allocated at I<*fds> so typically 41this function is called twice (once with a NULL I<fds> parameter and once 42without). 43 44SSL_get_changed_async_fds() returns a list of the asynchronous file descriptors 45that have been added and a list that have been deleted since the last 46B<SSL_ERROR_WANT_ASYNC> was received (or since the B<SSL> object was created if 47no B<SSL_ERROR_WANT_ASYNC> has been received). Similar to SSL_get_all_async_fds() 48it is the callers responsibility to ensure that I<*addfd> and I<*delfd> have 49sufficient memory allocated, although they may be NULL. The number of added fds 50and the number of deleted fds are stored in I<*numaddfds> and I<*numdelfds> 51respectively. 52 53=head1 RETURN VALUES 54 55SSL_waiting_for_async() will return 1 if the current SSL operation is waiting 56for an async operation to complete and 0 otherwise. 57 58SSL_get_all_async_fds() and SSL_get_changed_async_fds() return 1 on success or 590 on error. 60 61=head1 NOTES 62 63On Windows platforms the F<< <openssl/async.h> >> header is dependent on some 64of the types customarily made available by including F<< <windows.h> >>. The 65application developer is likely to require control over when the latter 66is included, commonly as one of the first included headers. Therefore, 67it is defined as an application developer's responsibility to include 68F<< <windows.h> >> prior to F<< <openssl/async.h> >>. 69 70=head1 SEE ALSO 71 72L<ssl(7)>, 73L<SSL_get_error(3)>, L<SSL_CTX_set_mode(3)> 74 75=head1 HISTORY 76 77The SSL_waiting_for_async(), SSL_get_all_async_fds() 78and SSL_get_changed_async_fds() functions were added in OpenSSL 1.1.0. 79 80=head1 COPYRIGHT 81 82Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved. 83 84Licensed under the Apache License 2.0 (the "License"). You may not use 85this file except in compliance with the License. You can obtain a copy 86in the file LICENSE in the source distribution or at 87L<https://www.openssl.org/source/license.html>. 88 89=cut 90