mirror of
https://github.com/openssl/openssl.git
synced 2024-12-21 06:09:35 +08:00
193 lines
6.6 KiB
Plaintext
193 lines
6.6 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
BIO_s_connect, BIO_new_connect, BIO_set_conn_hostname, BIO_set_conn_port,
|
|
BIO_set_conn_ip, BIO_set_conn_int_port, BIO_get_conn_hostname,
|
|
BIO_get_conn_port, BIO_get_conn_ip, BIO_get_conn_int_port,
|
|
BIO_set_nbio, BIO_do_connect - connect BIO
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/bio.h>
|
|
|
|
BIO_METHOD * BIO_s_connect(void);
|
|
|
|
BIO *BIO_new_connect(char *name);
|
|
|
|
long BIO_set_conn_hostname(BIO *b, char *name);
|
|
long BIO_set_conn_port(BIO *b, char *port);
|
|
long BIO_set_conn_ip(BIO *b, char *ip);
|
|
long BIO_set_conn_int_port(BIO *b, char *port);
|
|
char *BIO_get_conn_hostname(BIO *b);
|
|
char *BIO_get_conn_port(BIO *b);
|
|
char *BIO_get_conn_ip(BIO *b);
|
|
long BIO_get_conn_int_port(BIO *b);
|
|
|
|
long BIO_set_nbio(BIO *b, long n);
|
|
|
|
int BIO_do_connect(BIO *b);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
BIO_s_connect() returns the connect BIO method. This is a wrapper
|
|
round the platform's TCP/IP socket connection routines.
|
|
|
|
Using connect BIOs, TCP/IP connections can be made and data
|
|
transferred using only BIO routines. In this way any platform
|
|
specific operations are hidden by the BIO abstraction.
|
|
|
|
Read and write operations on a connect BIO will perform I/O
|
|
on the underlying connection. If no connection is established
|
|
and the port and hostname (see below) is set up properly then
|
|
a connection is established first.
|
|
|
|
Connect BIOs support BIO_puts() but not BIO_gets().
|
|
|
|
If the close flag is set on a connect BIO then any active
|
|
connection is shutdown and the socket closed when the BIO
|
|
is freed.
|
|
|
|
Calling BIO_reset() on a connect BIO will close any active
|
|
connection and reset the BIO into a state where it can connect
|
|
to the same host again.
|
|
|
|
BIO_get_fd() places the underlying socket in B<c> if it is not NULL,
|
|
it also returns the socket . If B<c> is not NULL it should be of
|
|
type (int *).
|
|
|
|
BIO_set_conn_hostname() uses the string B<name> to set the hostname.
|
|
The hostname can be an IP address. The hostname can also include the
|
|
port in the form hostname:port . It is also acceptable to use the
|
|
form "hostname/any/other/path" or "hostname:port/any/other/path".
|
|
|
|
BIO_set_conn_port() sets the port to B<port>. B<port> can be the
|
|
numerical form or a string such as "http". A string will be looked
|
|
up first using getservbyname() on the host platform but if that
|
|
fails a standard table of port names will be used. This internal
|
|
list is http, telnet, socks, https, ssl, ftp, and gopher.
|
|
|
|
BIO_set_conn_ip() sets the IP address to B<ip> using binary form,
|
|
that is four bytes specifying the IP address in big-endian form.
|
|
|
|
BIO_set_conn_int_port() sets the port using B<port>. B<port> should
|
|
be of type (int *).
|
|
|
|
BIO_get_conn_hostname() returns the hostname of the connect BIO or
|
|
NULL if the BIO is initialized but no hostname is set.
|
|
This return value is an internal pointer which should not be modified.
|
|
|
|
BIO_get_conn_port() returns the port as a string.
|
|
|
|
BIO_get_conn_ip() returns the IP address in binary form.
|
|
|
|
BIO_get_conn_int_port() returns the port as an int.
|
|
|
|
BIO_set_nbio() sets the non blocking I/O flag to B<n>. If B<n> is
|
|
zero then blocking I/O is set. If B<n> is 1 then non blocking I/O
|
|
is set. Blocking I/O is the default. The call to BIO_set_nbio()
|
|
should be made before the connection is established because
|
|
non blocking I/O is set during the connect process.
|
|
|
|
BIO_new_connect() combines BIO_new() and BIO_set_conn_hostname() into
|
|
a single call: that is it creates a new connect BIO with B<name>.
|
|
|
|
BIO_do_connect() attempts to connect the supplied BIO. It returns 1
|
|
if the connection was established successfully. A zero or negative
|
|
value is returned if the connection could not be established, the
|
|
call BIO_should_retry() should be used for non blocking connect BIOs
|
|
to determine if the call should be retried.
|
|
|
|
=head1 NOTES
|
|
|
|
If blocking I/O is set then a non positive return value from any
|
|
I/O call is caused by an error condition, although a zero return
|
|
will normally mean that the connection was closed.
|
|
|
|
If the port name is supplied as part of the host name then this will
|
|
override any value set with BIO_set_conn_port(). This may be undesirable
|
|
if the application does not wish to allow connection to arbitrary
|
|
ports. This can be avoided by checking for the presence of the ':'
|
|
character in the passed hostname and either indicating an error or
|
|
truncating the string at that point.
|
|
|
|
The values returned by BIO_get_conn_hostname(), BIO_get_conn_port(),
|
|
BIO_get_conn_ip() and BIO_get_conn_int_port() are updated when a
|
|
connection attempt is made. Before any connection attempt the values
|
|
returned are those set by the application itself.
|
|
|
|
Applications do not have to call BIO_do_connect() but may wish to do
|
|
so to separate the connection process from other I/O processing.
|
|
|
|
If non blocking I/O is set then retries will be requested as appropriate.
|
|
|
|
It addition to BIO_should_read() and BIO_should_write() it is also
|
|
possible for BIO_should_io_special() to be true during the initial
|
|
connection process with the reason BIO_RR_CONNECT. If this is returned
|
|
then this is an indication that a connection attempt would block,
|
|
the application should then take appropriate action to wait until
|
|
the underlying socket has connected and retry the call.
|
|
|
|
BIO_set_conn_hostname(), BIO_set_conn_port(), BIO_set_conn_ip(),
|
|
BIO_set_conn_int_port(), BIO_get_conn_hostname(), BIO_get_conn_port(),
|
|
BIO_get_conn_ip(), BIO_get_conn_int_port(), BIO_set_nbio() and
|
|
BIO_do_connect() are macros.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
BIO_s_connect() returns the connect BIO method.
|
|
|
|
BIO_get_fd() returns the socket or -1 if the BIO has not
|
|
been initialized.
|
|
|
|
BIO_set_conn_hostname(), BIO_set_conn_port(), BIO_set_conn_ip() and
|
|
BIO_set_conn_int_port() always return 1.
|
|
|
|
BIO_get_conn_hostname() returns the connected hostname or NULL is
|
|
none was set.
|
|
|
|
BIO_get_conn_port() returns a string representing the connected
|
|
port or NULL if not set.
|
|
|
|
BIO_get_conn_ip() returns a pointer to the connected IP address in
|
|
binary form or all zeros if not set.
|
|
|
|
BIO_get_conn_int_port() returns the connected port or 0 if none was
|
|
set.
|
|
|
|
BIO_set_nbio() always returns 1.
|
|
|
|
BIO_do_connect() returns 1 if the connection was successfully
|
|
established and 0 or -1 if the connection failed.
|
|
|
|
=head1 EXAMPLE
|
|
|
|
This is example connects to a webserver on the local host and attempts
|
|
to retrieve a page and copy the result to standard output.
|
|
|
|
|
|
BIO *cbio, *out;
|
|
int len;
|
|
char tmpbuf[1024];
|
|
ERR_load_crypto_strings();
|
|
cbio = BIO_new_connect("localhost:http");
|
|
out = BIO_new_fp(stdout, BIO_NOCLOSE);
|
|
if(BIO_do_connect(cbio) <= 0) {
|
|
fprintf(stderr, "Error connecting to server\n");
|
|
ERR_print_errors_fp(stderr);
|
|
/* whatever ... */
|
|
}
|
|
BIO_puts(cbio, "GET / HTTP/1.0\n\n");
|
|
for(;;) {
|
|
len = BIO_read(cbio, tmpbuf, 1024);
|
|
if(len <= 0) break;
|
|
BIO_write(out, tmpbuf, len);
|
|
}
|
|
BIO_free(cbio);
|
|
BIO_free(out);
|
|
|
|
|
|
=head1 SEE ALSO
|
|
|
|
TBA
|