DragonFly On-Line Manual Pages
BIO(3) DragonFly Library Functions Manual BIO(3)
NAME
BIO -- I/O abstraction
SYNOPSIS
#include <openssl/bio.h>
DESCRIPTION
A BIO is an I/O abstraction, it hides many of the underlying I/O details
from an application. If an application uses a BIO for its I/O, it can
transparently handle SSL connections, unencrypted network connections and
file I/O.
There are two types of BIO, a source/sink BIO and a filter BIO.
As its name implies, a source/sink BIO is a source and/or sink of data,
examples include a socket BIO and a file BIO.
A filter BIO takes data from one BIO and passes it through to another, or
to the application. The data may be left unmodified (for example a mes-
sage digest BIO) or translated (for example an encryption BIO). The
effect of a filter BIO may change according to the I/O operation it is
performing: for example an encryption BIO will encrypt data if it is
being written to and decrypt data if it is being read from.
BIOs can be joined together to form a chain (a single BIO is a chain with
one component). A chain normally consist of one source/sink BIO and one
or more filter BIOs. Data read from or written to the first BIO then
traverses the chain to the end (normally a source/sink BIO).
SEE ALSO
BIO_ctrl(3), BIO_f_base64(3), BIO_f_buffer(3), BIO_f_cipher(3),
BIO_f_md(3), BIO_f_null(3), BIO_f_ssl(3), BIO_find_type(3), BIO_new(3),
BIO_new_bio_pair(3), BIO_push(3), BIO_read(3), BIO_s_accept(3),
BIO_s_bio(3), BIO_s_connect(3), BIO_s_fd(3), BIO_s_file(3), BIO_s_mem(3),
BIO_s_null(3), BIO_s_socket(3), BIO_set_callback(3), BIO_should_retry(3)
DragonFly 4.7 July 17, 2014 DragonFly 4.7
BIO_s_socket(3) OpenSSL BIO_s_socket(3)
NAME
BIO_s_socket, BIO_new_socket - socket BIO
SYNOPSIS
#include <openssl/bio.h>
BIO_METHOD *BIO_s_socket(void);
long BIO_set_fd(BIO *b, int fd, long close_flag);
long BIO_get_fd(BIO *b, int *c);
BIO *BIO_new_socket(int sock, int close_flag);
DESCRIPTION
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.
NOTES
Socket BIOs also support any relevant functionality of file descriptor
BIOs.
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.
RETURN VALUES
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
initialized.
BIO_new_socket() returns the newly allocated BIO or NULL is an error
occurred.
SEE ALSO
TBA
1.0.2h 2016-05-03 BIO_s_socket(3)