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_ADDRINFO(3) OpenSSL BIO_ADDRINFO(3)
NAME
BIO_lookup_type, BIO_ADDRINFO, BIO_ADDRINFO_next, BIO_ADDRINFO_free,
BIO_ADDRINFO_family, BIO_ADDRINFO_socktype, BIO_ADDRINFO_protocol,
BIO_ADDRINFO_address, BIO_lookup_ex, BIO_lookup - BIO_ADDRINFO type and
routines
SYNOPSIS
#include <sys/types.h>
#include <openssl/bio.h>
typedef union bio_addrinfo_st BIO_ADDRINFO;
enum BIO_lookup_type {
BIO_LOOKUP_CLIENT, BIO_LOOKUP_SERVER
};
int BIO_lookup_ex(const char *host, const char *service, int lookup_type,
int family, int socktype, int protocol, BIO_ADDRINFO **res);
int BIO_lookup(const char *node, const char *service,
enum BIO_lookup_type lookup_type,
int family, int socktype, BIO_ADDRINFO **res);
const BIO_ADDRINFO *BIO_ADDRINFO_next(const BIO_ADDRINFO *bai);
int BIO_ADDRINFO_family(const BIO_ADDRINFO *bai);
int BIO_ADDRINFO_socktype(const BIO_ADDRINFO *bai);
int BIO_ADDRINFO_protocol(const BIO_ADDRINFO *bai);
const BIO_ADDR *BIO_ADDRINFO_address(const BIO_ADDRINFO *bai);
void BIO_ADDRINFO_free(BIO_ADDRINFO *bai);
DESCRIPTION
The BIO_ADDRINFO type is a wrapper for address information types
provided on your platform.
BIO_ADDRINFO normally forms a chain of several that can be picked at
one by one.
BIO_lookup_ex() looks up a specified host and service, and uses
lookup_type to determine what the default address should be if host is
NULL. family, socktype and protocol are used to determine what protocol
family, socket type and protocol should be used for the lookup. family
can be any of AF_INET, AF_INET6, AF_UNIX and AF_UNSPEC. socktype can be
SOCK_STREAM, SOCK_DGRAM or 0. Specifying 0 indicates that any type can
be used. protocol specifies a protocol such as IPPROTO_TCP, IPPROTO_UDP
or IPPORTO_SCTP. If set to 0 than any protocol can be used. res points
at a pointer to hold the start of a BIO_ADDRINFO chain.
For the family AF_UNIX, BIO_lookup_ex() will ignore the service
parameter and expects the node parameter to hold the path to the socket
file.
BIO_lookup() does the same as BIO_lookup_ex() but does not provide the
ability to select based on the protocol (any protocol may be returned).
BIO_ADDRINFO_family() returns the family of the given BIO_ADDRINFO.
The result will be one of the constants AF_INET, AF_INET6 and AF_UNIX.
BIO_ADDRINFO_socktype() returns the socket type of the given
BIO_ADDRINFO. The result will be one of the constants SOCK_STREAM and
SOCK_DGRAM.
BIO_ADDRINFO_protocol() returns the protocol id of the given
BIO_ADDRINFO. The result will be one of the constants IPPROTO_TCP and
IPPROTO_UDP.
BIO_ADDRINFO_address() returns the underlying BIO_ADDR of the given
BIO_ADDRINFO.
BIO_ADDRINFO_next() returns the next BIO_ADDRINFO in the chain from the
given one.
BIO_ADDRINFO_free() frees the chain of BIO_ADDRINFO starting with the
given one.
RETURN VALUES
BIO_lookup_ex() and BIO_lookup() return 1 on success and 0 when an
error occurred, and will leave an error indication on the OpenSSL error
stack in that case.
All other functions described here return 0 or NULL when the
information they should return isn't available.
NOTES
The BIO_lookup_ex() implementation uses the platform provided
getaddrinfo() function. On Linux it is known that specifying 0 for the
protocol will not return any SCTP based addresses when calling
getaddrinfo(). Therefore, if an SCTP address is required then the
protocol parameter to BIO_lookup_ex() should be explicitly set to
IPPROTO_SCTP. The same may be true on other platforms.
HISTORY
The BIO_lookup_ex() function was added in OpenSSL 1.1.1.
COPYRIGHT
Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
1.1.1v 2023-08-01 BIO_ADDRINFO(3)