SSL_CTX_set_read_ahead.3ssl man page

SSL_CTX_set_read_ahead, SSL_CTX_get_read_ahead, SSL_set_read_ahead, SSL_get_read_ahead, SSL_CTX_get_default_read_ahead — manage whether to read as many input bytes as possible


#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_set_read_ahead() and SSL_set_read_ahead() set whether we should read as many input bytes as possible (for non-blocking reads) or not. For example if x bytes are currently required by OpenSSL, but y bytes are available from the underlying BIO (where y > x), then OpenSSL will read all y bytes into its buffer (providing that the buffer is large enough) if reading ahead is on, or x bytes otherwise. The parameter yes or m should be 0 to ensure reading ahead is off, or non zero otherwise. SSL_CTX_set_default_read_ahead() is identical to SSL_CTX_set_read_ahead().

SSL_CTX_get_read_ahead() and SSL_get_read_ahead() indicate whether reading ahead has been set or not.


These functions have no impact when used with DTLS. The return values for SSL_CTX_get_read_head() and SSL_get_read_ahead() are undefined for DTLS. Setting read_ahead can impact the behaviour of the SSL_pending() function (see SSL_pending(3)).

Return Values

SSL_get_read_ahead() and SSL_CTX_get_read_ahead() return 0 if reading ahead is off, and non zero otherwise.

See Also

ssl(3), SSL_pending(3)