#include <openssl/ssl.h> void SSL_set_read_ahead(SSL *s, int yes); int SSL_get_read_ahead(const SSL *s); SSL_CTX_set_read_ahead(SSL_CTX *ctx, int yes); long SSL_CTX_get_read_ahead(SSL_CTX *ctx); long SSL_CTX_get_default_read_ahead(SSL_CTX *ctx);
SSL_CTX_get_read_ahead() and SSL_get_read_ahead() indicate whether reading ahead has been set or not. SSL_CTX_get_default_read_ahead() is identical to SSL_CTX_get_read_ahead().
Since SSL_read() can return SSL_ERROR_WANT_READ for non-application data records, and SSL_has_pending() can't tell the difference between processed and unprocessed data, it's recommended that if read ahead is turned on that SSL_MODE_AUTO_RETRY is not turned off using SSL_CTX_clear_mode(). That will prevent getting SSL_ERROR_WANT_READ when there is still a complete record available that hasn't been processed.
If the application wants to continue to use the underlying transport (e.g. TCP connection) after the SSL connection is finished using SSL_shutdown() reading ahead should be turned off. Otherwise the SSL structure might read data that it shouldn't.
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 https://www.openssl.org/source/license.html.