SSL_get_fd -- get file descriptor linked to an SSL object
Synopsis
#include <openssl/ssl.h>
int SSL_get_fd(const SSL *ssl);
int SSL_get_rfd(const SSL *ssl);
int SSL_get_wfd(const SSL *ssl);
DESCRIPTION
SSL_get_fd() returns the file descriptor which is linked to ssl. SSL_get_rfd() and SSL_get_wfd() return
the file descriptors for the read or the write channel, which can be
different. If the read and the write channel are different,
SSL_get_fd() will return the file descriptor of the read channel.
RETURN VALUES
The following return values can occur:
-1
The operation failed, because the underlying BIO is not of
the correct type (suitable for file descriptors).
