X-Git-Url: https://code.wpia.club/?a=blobdiff_plain;f=lib%2Fopenssl%2Fdoc%2Fssl%2FSSL_pending.pod;h=f6ed5652a138687144fe23d451c11129db96cfc7;hb=HEAD;hp=43f2874e8b6aee252bf1db30398f456620a52746;hpb=ba8f20d49b7c8142babdbe783ebd9c937405ba13;p=cassiopeia.git diff --git a/lib/openssl/doc/ssl/SSL_pending.pod b/lib/openssl/doc/ssl/SSL_pending.pod index 43f2874..f6ed565 100644 --- a/lib/openssl/doc/ssl/SSL_pending.pod +++ b/lib/openssl/doc/ssl/SSL_pending.pod @@ -2,42 +2,67 @@ =head1 NAME -SSL_pending - obtain number of readable bytes buffered in an SSL object +SSL_pending, SSL_has_pending - check for readable bytes buffered in an +SSL object =head1 SYNOPSIS #include int SSL_pending(const SSL *ssl); + int SSL_has_pending(const SSL *s); =head1 DESCRIPTION -SSL_pending() returns the number of bytes which are available inside -B for immediate read. +Data is received in whole blocks known as records from the peer. A whole record +is processed (e.g. decrypted) in one go and is buffered by OpenSSL until it is +read by the application via a call to L. + +SSL_pending() returns the number of bytes which have been processed, buffered +and are available inside B for immediate read. + +If the B object's I flag is set (see +L), additional protocol bytes (beyond the current +record) may have been read containing more TLS/SSL records. This also applies to +DTLS and pipelining (see L). These +additional bytes will be buffered by OpenSSL but will remain unprocessed until +they are needed. As these bytes are still in an unprocessed state SSL_pending() +will ignore them. Therefore it is possible for no more bytes to be readable from +the underlying BIO (because OpenSSL has already read them) and for SSL_pending() +to return 0, even though readable application data bytes are available (because +the data is in unprocessed buffered records). + +SSL_has_pending() returns 1 if B has buffered data (whether processed or +unprocessed) and 0 otherwise. Note that it is possible for SSL_has_pending() to +return 1, and then a subsequent call to SSL_read() to return no data because the +unprocessed buffered data when processed yielded no application data (for +example this can happen during renegotiation). It is also possible in this +scenario for SSL_has_pending() to continue to return 1 even after an SSL_read() +call because the buffered and unprocessed data is not yet processable (e.g. +because OpenSSL has only received a partial record so far). -=head1 NOTES +=head1 RETURN VALUES -Data are received in blocks from the peer. Therefore data can be buffered -inside B and are ready for immediate retrieval with -L. +SSL_pending() returns the number of buffered and processed application data +bytes that are pending and are available for immediate read. SSL_has_pending() +returns 1 if there is buffered record data in the SSL object and 0 otherwise. -=head1 RETURN VALUES +=head1 SEE ALSO -The number of bytes pending is returned. +L, L, +L, L -=head1 BUGS +=head1 HISTORY -SSL_pending() takes into account only bytes from the TLS/SSL record -that is currently being processed (if any). If the B object's -I flag is set, additional protocol bytes may have been -read containing more TLS/SSL records; these are ignored by -SSL_pending(). +The SSL_has_pending() function was added in OpenSSL 1.1.0. -Up to OpenSSL 0.9.6, SSL_pending() does not check if the record type -of pending data is application data. +=head1 COPYRIGHT -=head1 SEE ALSO +Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved. -L, L +Licensed under the OpenSSL license (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 +L. =cut