.\"	$OpenBSD: BIO_s_socket.3,v 1.10 2023/04/11 16:58:43 schwarze Exp $
.\"	OpenSSL bbdc9c98 Oct 19 22:02:21 2000 +0000
.\"
.\" This file was written by Dr. Stephen Henson <steve@openssl.org>.
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.Dd $Mdocdate: April 11 2023 $
.Dt BIO_S_SOCKET 3
.Os
.Sh NAME
.Nm BIO_s_socket ,
.Nm BIO_new_socket
.Nd socket BIO
.Sh SYNOPSIS
.In openssl/bio.h
.Ft const BIO_METHOD *
.Fo BIO_s_socket
.Fa void
.Fc
.Ft BIO *
.Fo BIO_new_socket
.Fa "int sock"
.Fa "int close_flag"
.Fc
.Sh DESCRIPTION
.Fn BIO_s_socket
returns the socket BIO method.
This is a wrapper around the platform's socket routines.
.Pp
.Xr BIO_read 3
and
.Xr BIO_write 3
read or write the underlying socket.
.Xr BIO_puts 3
is supported but
.Xr BIO_gets 3
is not.
.Pp
If the close flag is set, then the socket is shut down and closed
when the BIO is freed.
.Pp
.Fn BIO_new_socket
returns a socket BIO using
.Fa sock
and
.Fa close_flag .
.Pp
Socket BIOs also support any relevant functionality of file descriptor BIOs.
.Pp
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.
.Sh RETURN VALUES
.Fn BIO_s_socket
returns the socket BIO method.
.Pp
.Fn BIO_new_socket
returns the newly allocated BIO or
.Dv NULL
if an error occurred.
.Pp
When called on a socket BIO object,
.Xr BIO_method_type 3
returns the constant
.Dv BIO_TYPE_SOCKET
and
.Xr BIO_method_name 3
returns a pointer to the static string
.Qq socket .
.Sh SEE ALSO
.Xr BIO_get_fd 3 ,
.Xr BIO_new 3
.Sh HISTORY
.Fn BIO_s_socket
first appeared in SSLeay 0.6.0.
.Fn BIO_new_socket
first appeared in SSLeay 0.8.0.
Both functions have been available since
.Ox 2.4 .