[thirdparty/openssl.git] / doc / man3 / BIO_connect.pod

=pod

=head1 NAME

BIO_socket, BIO_bind, BIO_connect, BIO_listen, BIO_accept_ex, BIO_closesocket - BIO
socket communication setup routines

=head1 SYNOPSIS

 #include <openssl/bio.h>

 int BIO_socket(int domain, int socktype, int protocol, int options);
 int BIO_bind(int sock, const BIO_ADDR *addr, int options);
 int BIO_connect(int sock, const BIO_ADDR *addr, int options);
 int BIO_listen(int sock, const BIO_ADDR *addr, int options);
 int BIO_accept_ex(int accept_sock, BIO_ADDR *peer, int options);
 int BIO_closesocket(int sock);

=head1 DESCRIPTION

BIO_socket() creates a socket in the domain B<domain>, of type
B<socktype> and B<protocol>.  Socket B<options> are currently unused,
but is present for future use.

BIO_bind() binds the source address and service to a socket and
may be useful before calling BIO_connect().  The options may include
B<BIO_SOCK_REUSEADDR>, which is described in L</FLAGS> below.

BIO_connect() connects B<sock> to the address and service given by
B<addr>.  Connection B<options> may be zero or any combination of
B<BIO_SOCK_KEEPALIVE>, B<BIO_SOCK_NONBLOCK> and B<BIO_SOCK_NODELAY>.
The flags are described in L</FLAGS> below.

BIO_listen() has B<sock> start listening on the address and service
given by B<addr>.  Connection B<options> may be zero or any
combination of B<BIO_SOCK_KEEPALIVE>, B<BIO_SOCK_NONBLOCK>,
B<BIO_SOCK_NODELAY>, B<BIO_SOCK_REUSEADDR> and B<BIO_SOCK_V6_ONLY>.
The flags are described in L</FLAGS> below.

BIO_accept_ex() waits for an incoming connections on the given
socket B<accept_sock>.  When it gets a connection, the address and
port of the peer gets stored in B<peer> if that one is non-NULL.
Accept B<options> may be zero or B<BIO_SOCK_NONBLOCK>, and is applied
on the accepted socket.  The flags are described in L</FLAGS> below.

BIO_closesocket() closes B<sock>.

=head1 FLAGS

=over 4

=item BIO_SOCK_KEEPALIVE

Enables regular sending of keep-alive messages.

=item BIO_SOCK_NONBLOCK

Sets the socket to nonblocking mode.

=item BIO_SOCK_NODELAY

Corresponds to B<TCP_NODELAY>, and disables the Nagle algorithm.  With
this set, any data will be sent as soon as possible instead of being
buffered until there's enough for the socket to send out in one go.

=item BIO_SOCK_REUSEADDR

Try to reuse the address and port combination for a recently closed
port.

=item BIO_SOCK_V6_ONLY

When creating an IPv6 socket, make it only listen for IPv6 addresses
and not IPv4 addresses mapped to IPv6.

=item BIO_SOCK_TFO

Enables TCP Fast Open on the socket. Uses appropriate APIs on
supported operating systems, including Linux, macOS and FreeBSD. Can
be used with BIO_connect(), BIO_set_conn_mode(), BIO_set_bind_mode(),
and BIO_listen().
On Linux kernels before 4.14, use BIO_set_conn_address() to specify
the peer address before starting the TLS handshake.

=back

These flags are bit flags, so they are to be combined with the
C<|> operator, for example:

 BIO_connect(sock, addr, BIO_SOCK_KEEPALIVE | BIO_SOCK_NONBLOCK);

=head1 RETURN VALUES

BIO_socket() returns the socket number on success or B<INVALID_SOCKET>
(-1) on error.  When an error has occurred, the OpenSSL error stack
will hold the error data and errno has the system error.

BIO_bind(), BIO_connect() and BIO_listen() return 1 on success or 0 on error.
When an error has occurred, the OpenSSL error stack will hold the error
data and errno has the system error.

BIO_accept_ex() returns the accepted socket on success or
B<INVALID_SOCKET> (-1) on error.  When an error has occurred, the
OpenSSL error stack will hold the error data and errno has the system
error.

=head1 SEE ALSO

L<BIO_ADDR(3)>

=head1 HISTORY

BIO_gethostname(), BIO_get_port(), BIO_get_host_ip(),
BIO_get_accept_socket() and BIO_accept() were deprecated in OpenSSL 1.1.0.
Use the functions described above instead.

=head1 COPYRIGHT

Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (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
L<https://www.openssl.org/source/license.html>.

=cut
Commit	Line	Data
d33b215b RL	1	=pod
	2
	3	=head1 NAME
	4
ebc01683	5	BIO_socket, BIO_bind, BIO_connect, BIO_listen, BIO_accept_ex, BIO_closesocket - BIO
d33b215b RL	6	socket communication setup routines
	7
	8	=head1 SYNOPSIS
	9
	10	#include <openssl/bio.h>
	11
	12	int BIO_socket(int domain, int socktype, int protocol, int options);
ebc01683	13	int BIO_bind(int sock, const BIO_ADDR *addr, int options);
d33b215b RL	14	int BIO_connect(int sock, const BIO_ADDR *addr, int options);
	15	int BIO_listen(int sock, const BIO_ADDR *addr, int options);
	16	int BIO_accept_ex(int accept_sock, BIO_ADDR *peer, int options);
	17	int BIO_closesocket(int sock);
	18
	19	=head1 DESCRIPTION
	20
	21	BIO_socket() creates a socket in the domain B<domain>, of type
	22	B<socktype> and B<protocol>. Socket B<options> are currently unused,
	23	but is present for future use.
	24
ebc01683 JH	25	BIO_bind() binds the source address and service to a socket and
ebc01683 JH	26	may be useful before calling BIO_connect(). The options may include
ea8d07b1	27	B<BIO_SOCK_REUSEADDR>, which is described in L</FLAGS> below.
ebc01683	28
d33b215b RL	29	BIO_connect() connects B<sock> to the address and service given by
	30	B<addr>. Connection B<options> may be zero or any combination of
	31	B<BIO_SOCK_KEEPALIVE>, B<BIO_SOCK_NONBLOCK> and B<BIO_SOCK_NODELAY>.
	32	The flags are described in L</FLAGS> below.
	33
	34	BIO_listen() has B<sock> start listening on the address and service
	35	given by B<addr>. Connection B<options> may be zero or any
	36	combination of B<BIO_SOCK_KEEPALIVE>, B<BIO_SOCK_NONBLOCK>,
	37	B<BIO_SOCK_NODELAY>, B<BIO_SOCK_REUSEADDR> and B<BIO_SOCK_V6_ONLY>.
	38	The flags are described in L</FLAGS> below.
	39
	40	BIO_accept_ex() waits for an incoming connections on the given
	41	socket B<accept_sock>. When it gets a connection, the address and
	42	port of the peer gets stored in B<peer> if that one is non-NULL.
	43	Accept B<options> may be zero or B<BIO_SOCK_NONBLOCK>, and is applied
	44	on the accepted socket. The flags are described in L</FLAGS> below.
	45
	46	BIO_closesocket() closes B<sock>.
	47
	48	=head1 FLAGS
	49
	50	=over 4
	51
	52	=item BIO_SOCK_KEEPALIVE
	53
	54	Enables regular sending of keep-alive messages.
	55
	56	=item BIO_SOCK_NONBLOCK
	57
490c8711	58	Sets the socket to nonblocking mode.
d33b215b RL	59
	60	=item BIO_SOCK_NODELAY
	61
	62	Corresponds to B<TCP_NODELAY>, and disables the Nagle algorithm. With
	63	this set, any data will be sent as soon as possible instead of being
	64	buffered until there's enough for the socket to send out in one go.
	65
	66	=item BIO_SOCK_REUSEADDR
	67
	68	Try to reuse the address and port combination for a recently closed
	69	port.
	70
	71	=item BIO_SOCK_V6_ONLY
	72
	73	When creating an IPv6 socket, make it only listen for IPv6 addresses
	74	and not IPv4 addresses mapped to IPv6.
	75
a3e53d56 TS	76	=item BIO_SOCK_TFO
	77
	78	Enables TCP Fast Open on the socket. Uses appropriate APIs on
	79	supported operating systems, including Linux, macOS and FreeBSD. Can
	80	be used with BIO_connect(), BIO_set_conn_mode(), BIO_set_bind_mode(),
	81	and BIO_listen().
	82	On Linux kernels before 4.14, use BIO_set_conn_address() to specify
	83	the peer address before starting the TLS handshake.
	84
d33b215b RL	85	=back
	86
	87	These flags are bit flags, so they are to be combined with the
	88	C<\|> operator, for example:
	89
2947af32	90	BIO_connect(sock, addr, BIO_SOCK_KEEPALIVE \| BIO_SOCK_NONBLOCK);
d33b215b RL	91
	92	=head1 RETURN VALUES
	93
	94	BIO_socket() returns the socket number on success or B<INVALID_SOCKET>
b9b6a7e5	95	(-1) on error. When an error has occurred, the OpenSSL error stack
d33b215b RL	96	will hold the error data and errno has the system error.
d33b215b RL	97
ebc01683	98	BIO_bind(), BIO_connect() and BIO_listen() return 1 on success or 0 on error.
b9b6a7e5	99	When an error has occurred, the OpenSSL error stack will hold the error
d33b215b RL	100	data and errno has the system error.
	101
	102	BIO_accept_ex() returns the accepted socket on success or
b9b6a7e5	103	B<INVALID_SOCKET> (-1) on error. When an error has occurred, the
d33b215b RL	104	OpenSSL error stack will hold the error data and errno has the system
	105	error.
	106
b5c4bbbe JL	107	=head1 SEE ALSO
	108
	109	L<BIO_ADDR(3)>
	110
d33b215b RL	111	=head1 HISTORY
	112
	113	BIO_gethostname(), BIO_get_port(), BIO_get_host_ip(),
938e82f6 JL	114	BIO_get_accept_socket() and BIO_accept() were deprecated in OpenSSL 1.1.0.
938e82f6 JL	115	Use the functions described above instead.
d33b215b	116
e2f92610 RS	117	=head1 COPYRIGHT
e2f92610 RS	118
fecb3aae	119	Copyright 2016-2022 The OpenSSL Project Authors. All Rights Reserved.
e2f92610	120
4746f25a	121	Licensed under the Apache License 2.0 (the "License"). You may not use
e2f92610 RS	122	this file except in compliance with the License. You can obtain a copy
	123	in the file LICENSE in the source distribution or at
	124	L<https://www.openssl.org/source/license.html>.
	125
	126	=cut