1SSL_GET_ALL_ASYNC_FDS(3ossl) OpenSSL SSL_GET_ALL_ASYNC_FDS(3ossl)
2
6 SSL_waiting_for_async, SSL_get_all_async_fds, SSL_get_changed_async_fds
7 - manage asynchronous operations
8
10 #include <openssl/async.h>
11 #include <openssl/ssl.h>
12 int SSL_waiting_for_async(SSL *s);
14 int SSL_get_all_async_fds(SSL *s, OSSL_ASYNC_FD *fd, size_t *numfds);
15 int SSL_get_changed_async_fds(SSL *s, OSSL_ASYNC_FD *addfd, size_t *numaddfds,
16 OSSL_ASYNC_FD *delfd, size_t *numdelfds);
17
19 SSL_waiting_for_async() determines whether an SSL connection is
20 currently waiting for asynchronous operations to complete (see the
21 SSL_MODE_ASYNC mode in SSL_CTX_set_mode(3)).
22 SSL_get_all_async_fds() returns a list of file descriptor which can be
24 used in a call to select() or poll() to determine whether the current
25 asynchronous operation has completed or not. A completed operation will
26 result in data appearing as "read ready" on the file descriptor (no
27 actual data should be read from the file descriptor). This function
28 should only be called if the SSL object is currently waiting for
29 asynchronous work to complete (i.e. SSL_ERROR_WANT_ASYNC has been
30 received - see SSL_get_error(3)). Typically the list will only contain
31 one file descriptor. However, if multiple asynchronous capable engines
32 are in use then more than one is possible. The number of file
33 descriptors returned is stored in *numfds and the file descriptors
34 themselves are in *fds. The fds parameter may be NULL in which case no
35 file descriptors are returned but *numfds is still populated. It is the
36 callers responsibility to ensure sufficient memory is allocated at *fds
37 so typically this function is called twice (once with a NULL fds
38 parameter and once without).
39 SSL_get_changed_async_fds() returns a list of the asynchronous file
41 descriptors that have been added and a list that have been deleted
42 since the last SSL_ERROR_WANT_ASYNC was received (or since the SSL
43 object was created if no SSL_ERROR_WANT_ASYNC has been received).
44 Similar to SSL_get_all_async_fds() it is the callers responsibility to
45 ensure that *addfd and *delfd have sufficient memory allocated,
46 although they may be NULL. The number of added fds and the number of
47 deleted fds are stored in *numaddfds and *numdelfds respectively.
48
50 SSL_waiting_for_async() will return 1 if the current SSL operation is
51 waiting for an async operation to complete and 0 otherwise.
52 SSL_get_all_async_fds() and SSL_get_changed_async_fds() return 1 on
54 success or 0 on error.
55
57 On Windows platforms the <openssl/async.h> header is dependent on some
58 of the types customarily made available by including <windows.h>. The
59 application developer is likely to require control over when the latter
60 is included, commonly as one of the first included headers. Therefore,
61 it is defined as an application developer's responsibility to include
62 <windows.h> prior to <openssl/async.h>.
63
65 ssl(7), SSL_get_error(3), SSL_CTX_set_mode(3)
66
68 The SSL_waiting_for_async(), SSL_get_all_async_fds() and
69 SSL_get_changed_async_fds() functions were added in OpenSSL 1.1.0.
70
72 Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
73 Licensed under the Apache License 2.0 (the "License"). You may not use
75 this file except in compliance with the License. You can obtain a copy
76 in the file LICENSE in the source distribution or at
77 <https://www.openssl.org/source/license.html>.
783.0.5 2022-07-05 SSL_GET_ALL_ASYNC_FDS(3ossl)