SSL_GET_ALL_ASYNC_FDS(3ossl) OpenSSL SSL_GET_ALL_ASYNC_FDS(3ossl)
NAME
SSL_waiting_for_async, SSL_get_all_async_fds, SSL_get_changed_async_fds
- manage asynchronous operations
SYNOPSIS
#include <openssl/async.h>
#include <openssl/ssl.h>
int SSL_waiting_for_async(SSL *s);
int SSL_get_all_async_fds(SSL *s, OSSL_ASYNC_FD *fd, size_t *numfds);
int SSL_get_changed_async_fds(SSL *s, OSSL_ASYNC_FD *addfd, size_t *numaddfds,
OSSL_ASYNC_FD *delfd, size_t *numdelfds);
DESCRIPTION
SSL_waiting_for_async() determines whether an SSL connection is
currently waiting for asynchronous operations to complete (see the
SSL_MODE_ASYNC mode in SSL_CTX_set_mode(3)).
SSL_get_all_async_fds(3) returns a list of file descriptor which can be
used in a call to select() or poll() to determine whether the current
asynchronous operation has completed or not. A completed operation will
result in data appearing as "read ready" on the file descriptor (no
actual data should be read from the file descriptor). This function
should only be called if the SSL object is currently waiting for
asynchronous work to complete (i.e. SSL_ERROR_WANT_ASYNC has been
received - see SSL_get_error(3)). Typically the list will only contain
one file descriptor. However, if multiple asynchronous capable engines
are in use then more than one is possible. The number of file
descriptors returned is stored in *numfds and the file descriptors
themselves are in *fds. The fds parameter may be NULL in which case no
file descriptors are returned but *numfds is still populated. It is the
callers responsibility to ensure sufficient memory is allocated at *fds
so typically this function is called twice (once with a NULL fds
parameter and once without).
SSL_get_changed_async_fds() returns a list of the asynchronous file
descriptors that have been added and a list that have been deleted
since the last SSL_ERROR_WANT_ASYNC was received (or since the SSL
object was created if no SSL_ERROR_WANT_ASYNC has been received).
Similar to SSL_get_all_async_fds(3) it is the callers responsibility to
ensure that *addfd and *delfd have sufficient memory allocated,
although they may be NULL. The number of added fds and the number of
deleted fds are stored in *numaddfds and *numdelfds respectively.
RETURN VALUES
SSL_waiting_for_async() will return 1 if the current SSL operation is
waiting for an async operation to complete and 0 otherwise.
SSL_get_all_async_fds(3) and SSL_get_changed_async_fds() return 1 on
success or 0 on error.
NOTES
On Windows platforms the <openssl/async.h> header is dependent on some
of the types customarily made available by including <windows.h>. The
application developer is likely to require control over when the latter
is included, commonly as one of the first included headers. Therefore,
it is defined as an application developer's responsibility to include
<windows.h> prior to <openssl/async.h>.
SEE ALSO
ssl(7), SSL_get_error(3), SSL_CTX_set_mode(3)
HISTORY
The SSL_get_all_async_fds(3) and
SSL_get_changed_async_fds() functions were added in OpenSSL 1.1.0.
COPYRIGHT
Copyright 2016-2021 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>.
3.3.2 2024-09-04 SSL_GET_ALL_ASYNC_FDS(3ossl)
openssl 3.3.2 - Generated Thu Sep 26 11:04:24 CDT 2024