xref: /freebsd/crypto/openssl/doc/man3/BIO_connect.pod (revision 5f4c09dd85bff675e0ca63c55ea3c517e0fddfcc)
1=pod
2
3=head1 NAME
4
5BIO_socket, BIO_bind, BIO_connect, BIO_listen, BIO_accept_ex, BIO_closesocket - BIO
6socket 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);
13 int BIO_bind(int sock, const BIO_ADDR *addr, int options);
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
21BIO_socket() creates a socket in the domain B<domain>, of type
22B<socktype> and B<protocol>.  Socket B<options> are currently unused,
23but is present for future use.
24
25BIO_bind() binds the source address and service to a socket and
26may be useful before calling BIO_connect().  The options may include
27B<BIO_SOCK_REUSEADDR>, which is described in L</FLAGS> below.
28
29BIO_connect() connects B<sock> to the address and service given by
30B<addr>.  Connection B<options> may be zero or any combination of
31B<BIO_SOCK_KEEPALIVE>, B<BIO_SOCK_NONBLOCK> and B<BIO_SOCK_NODELAY>.
32The flags are described in L</FLAGS> below.
33
34BIO_listen() has B<sock> start listening on the address and service
35given by B<addr>.  Connection B<options> may be zero or any
36combination of B<BIO_SOCK_KEEPALIVE>, B<BIO_SOCK_NONBLOCK>,
37B<BIO_SOCK_NODELAY>, B<BIO_SOCK_REUSEADDR> and B<BIO_SOCK_V6_ONLY>.
38The flags are described in L</FLAGS> below.
39
40BIO_accept_ex() waits for an incoming connections on the given
41socket B<accept_sock>.  When it gets a connection, the address and
42port of the peer gets stored in B<peer> if that one is non-NULL.
43Accept B<options> may be zero or B<BIO_SOCK_NONBLOCK>, and is applied
44on the accepted socket.  The flags are described in L</FLAGS> below.
45
46BIO_closesocket() closes B<sock>.
47
48=head1 FLAGS
49
50=over 4
51
52=item BIO_SOCK_KEEPALIVE
53
54Enables regular sending of keep-alive messages.
55
56=item BIO_SOCK_NONBLOCK
57
58Sets the socket to nonblocking mode.
59
60=item BIO_SOCK_NODELAY
61
62Corresponds to B<TCP_NODELAY>, and disables the Nagle algorithm.  With
63this set, any data will be sent as soon as possible instead of being
64buffered until there's enough for the socket to send out in one go.
65
66=item BIO_SOCK_REUSEADDR
67
68Try to reuse the address and port combination for a recently closed
69port.
70
71=item BIO_SOCK_V6_ONLY
72
73When creating an IPv6 socket, make it only listen for IPv6 addresses
74and not IPv4 addresses mapped to IPv6.
75
76=back
77
78These flags are bit flags, so they are to be combined with the
79C<|> operator, for example:
80
81 BIO_connect(sock, addr, BIO_SOCK_KEEPALIVE | BIO_SOCK_NONBLOCK);
82
83=head1 RETURN VALUES
84
85BIO_socket() returns the socket number on success or B<INVALID_SOCKET>
86(-1) on error.  When an error has occurred, the OpenSSL error stack
87will hold the error data and errno has the system error.
88
89BIO_bind(), BIO_connect() and BIO_listen() return 1 on success or 0 on error.
90When an error has occurred, the OpenSSL error stack will hold the error
91data and errno has the system error.
92
93BIO_accept_ex() returns the accepted socket on success or
94B<INVALID_SOCKET> (-1) on error.  When an error has occurred, the
95OpenSSL error stack will hold the error data and errno has the system
96error.
97
98=head1 SEE ALSO
99
100L<BIO_ADDR(3)>
101
102=head1 HISTORY
103
104BIO_gethostname(), BIO_get_port(), BIO_get_host_ip(),
105BIO_get_accept_socket() and BIO_accept() were deprecated in OpenSSL 1.1.0.
106Use the functions described above instead.
107
108=head1 COPYRIGHT
109
110Copyright 2016-2020 The OpenSSL Project Authors. All Rights Reserved.
111
112Licensed under the Apache License 2.0 (the "License").  You may not use
113this file except in compliance with the License.  You can obtain a copy
114in the file LICENSE in the source distribution or at
115L<https://www.openssl.org/source/license.html>.
116
117=cut
118