5 BIO_s_connect, BIO_new_connect,
6 BIO_set_conn_hostname, BIO_set_conn_port,
7 BIO_set_conn_address, BIO_set_conn_ip_family,
8 BIO_get_conn_hostname, BIO_get_conn_port,
9 BIO_get_conn_address, BIO_get_conn_ip_family,
10 BIO_set_nbio, BIO_do_connect - connect BIO
14 #include <openssl/bio.h>
16 const BIO_METHOD *BIO_s_connect(void);
18 BIO *BIO_new_connect(const char *name);
20 long BIO_set_conn_hostname(BIO *b, char *name);
21 long BIO_set_conn_port(BIO *b, char *port);
22 long BIO_set_conn_address(BIO *b, BIO_ADDR *addr);
23 long BIO_set_conn_ip_family(BIO *b, long family);
24 const char *BIO_get_conn_hostname(BIO *b);
25 const char *BIO_get_conn_port(BIO *b);
26 const BIO_ADDR *BIO_get_conn_address(BIO *b);
27 const long BIO_get_conn_ip_family(BIO *b);
29 long BIO_set_nbio(BIO *b, long n);
31 int BIO_do_connect(BIO *b);
35 BIO_s_connect() returns the connect BIO method. This is a wrapper
36 round the platform's TCP/IP socket connection routines.
38 Using connect BIOs, TCP/IP connections can be made and data
39 transferred using only BIO routines. In this way any platform
40 specific operations are hidden by the BIO abstraction.
42 Read and write operations on a connect BIO will perform I/O
43 on the underlying connection. If no connection is established
44 and the port and hostname (see below) is set up properly then
45 a connection is established first.
47 Connect BIOs support BIO_puts() and BIO_gets().
49 If the close flag is set on a connect BIO then any active
50 connection is shutdown and the socket closed when the BIO
53 Calling BIO_reset() on a connect BIO will close any active
54 connection and reset the BIO into a state where it can connect
55 to the same host again.
57 BIO_new_connect() combines BIO_new() and BIO_set_conn_hostname() into
58 a single call: that is it creates a new connect BIO with hostname B<name>.
60 BIO_set_conn_hostname() uses the string B<name> to set the hostname.
61 The hostname can be an IP address; if the address is an IPv6 one, it
62 must be enclosed with brackets C<[> and C<]>.
63 The hostname can also include the port in the form hostname:port;
64 see L<BIO_parse_hostserv(3)> and BIO_set_conn_port() for details.
66 BIO_set_conn_port() sets the port to B<port>. B<port> can be the
67 numerical form or a service string such as "http", which
68 will be mapped to a port number using the system function getservbyname().
70 BIO_set_conn_address() sets the address and port information using
73 BIO_set_conn_ip_family() sets the IP family.
75 BIO_get_conn_hostname() returns the hostname of the connect BIO or
76 NULL if the BIO is initialized but no hostname is set.
77 This return value is an internal pointer which should not be modified.
79 BIO_get_conn_port() returns the port as a string.
80 This return value is an internal pointer which should not be modified.
82 BIO_get_conn_address() returns the address information as a BIO_ADDR.
83 This return value is an internal pointer which should not be modified.
85 BIO_get_conn_ip_family() returns the IP family of the connect BIO.
87 BIO_set_nbio() sets the non blocking I/O flag to B<n>. If B<n> is
88 zero then blocking I/O is set. If B<n> is 1 then non blocking I/O
89 is set. Blocking I/O is the default. The call to BIO_set_nbio()
90 should be made before the connection is established because
91 non blocking I/O is set during the connect process.
93 BIO_do_connect() attempts to connect the supplied BIO.
94 This performs an SSL/TLS handshake as far as supported by the BIO.
95 For non-SSL BIOs the connection is done typically at TCP level.
96 If domain name resolution yields multiple IP addresses all of them are tried
97 after connect() failures.
98 The function returns 1 if the connection was established successfully.
99 A zero or negative value is returned if the connection could not be established.
100 The call BIO_should_retry() should be used for non blocking connect BIOs
101 to determine if the call should be retried.
102 If a connection has already been established this call has no effect.
106 If blocking I/O is set then a non positive return value from any
107 I/O call is caused by an error condition, although a zero return
108 will normally mean that the connection was closed.
110 If the port name is supplied as part of the hostname then this will
111 override any value set with BIO_set_conn_port(). This may be undesirable
112 if the application does not wish to allow connection to arbitrary
113 ports. This can be avoided by checking for the presence of the ':'
114 character in the passed hostname and either indicating an error or
115 truncating the string at that point.
117 The values returned by BIO_get_conn_hostname(), BIO_get_conn_address(),
118 and BIO_get_conn_port() are updated when a connection attempt is made.
119 Before any connection attempt the values returned are those set by the
122 Applications do not have to call BIO_do_connect() but may wish to do
123 so to separate the connection process from other I/O processing.
125 If non blocking I/O is set then retries will be requested as appropriate.
127 It addition to BIO_should_read() and BIO_should_write() it is also
128 possible for BIO_should_io_special() to be true during the initial
129 connection process with the reason BIO_RR_CONNECT. If this is returned
130 then this is an indication that a connection attempt would block,
131 the application should then take appropriate action to wait until
132 the underlying socket has connected and retry the call.
134 BIO_set_conn_hostname(), BIO_set_conn_port(), BIO_get_conn_hostname(),
135 BIO_set_conn_address(), BIO_get_conn_port(), BIO_get_conn_address(),
136 BIO_set_conn_ip_family(), BIO_get_conn_ip_family(),
137 BIO_set_nbio(), and BIO_do_connect() are macros.
141 BIO_s_connect() returns the connect BIO method.
143 BIO_set_conn_address(), BIO_set_conn_port(), and BIO_set_conn_ip_family()
144 return 1 or <=0 if an error occurs.
146 BIO_set_conn_hostname() returns 1 on success and <=0 on failure.
148 BIO_get_conn_address() returns the address information or NULL if none
151 BIO_get_conn_hostname() returns the connected hostname or NULL if
154 BIO_get_conn_ip_family() returns the address family or -1 if none was set.
156 BIO_get_conn_port() returns a string representing the connected
157 port or NULL if not set.
159 BIO_set_nbio() returns 1 or <=0 if an error occurs.
161 BIO_do_connect() returns 1 if the connection was successfully
162 established and <=0 if the connection failed.
166 This is example connects to a webserver on the local host and attempts
167 to retrieve a page and copy the result to standard output.
174 cbio = BIO_new_connect("localhost:http");
175 out = BIO_new_fp(stdout, BIO_NOCLOSE);
176 if (BIO_do_connect(cbio) <= 0) {
177 fprintf(stderr, "Error connecting to server\n");
178 ERR_print_errors_fp(stderr);
181 BIO_puts(cbio, "GET / HTTP/1.0\n\n");
183 len = BIO_read(cbio, tmpbuf, 1024);
186 BIO_write(out, tmpbuf, len);
194 L<BIO_ADDR(3)>, L<BIO_parse_hostserv(3)>
198 BIO_set_conn_int_port(), BIO_get_conn_int_port(), BIO_set_conn_ip(), and BIO_get_conn_ip()
199 were removed in OpenSSL 1.1.0.
200 Use BIO_set_conn_address() and BIO_get_conn_address() instead.
202 Connect BIOs support BIO_gets() since OpenSSL 3.1.
206 Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
208 Licensed under the Apache License 2.0 (the "License"). You may not use
209 this file except in compliance with the License. You can obtain a copy
210 in the file LICENSE in the source distribution or at
211 L<https://www.openssl.org/source/license.html>.