BIO_s_socket, BIO_new_socket — socket BIO
long BIO_set_fd(BIO *b, int fd, long
long BIO_get_fd(BIO *b, int *c);
*BIO_new_socket(int sock, int close_flag);
BIO_s_socket() returns the socket BIO method. This is a wrapper
round the platform's socket routines.
BIO_read() and BIO_write() read or write the underlying socket.
BIO_puts() is supported but BIO_gets() is not.
If the close flag is set then the socket is shut down and
closed when the BIO is freed.
BIO_set_fd() sets the socket of BIO b to fd and
the close flag to close_flag.
BIO_get_fd() places the socket in c if
it is not NULL, it also returns the socket. If c is
not NULL it should be of type (int *).
BIO_new_socket() returns a socket BIO using sock and close_flag.
Socket BIOs also support any relevant functionality of file
The reason for having separate file descriptor and socket
BIOs is that on some platforms sockets are not file descriptors
and use distinct I/O routines, Windows is one such platform. Any
code mixing the two will not work on all platforms.
BIO_set_fd() and BIO_get_fd() are macros.
BIO_s_socket() returns the socket BIO method.
BIO_set_fd() always returns 1.
BIO_get_fd() returns the socket or -1 if the BIO has not been
BIO_new_socket() returns the newly allocated BIO or NULL is
an error occurred.