doc/crypto/BIO_s_connect.pod - third_party/openssl - Git at Google

 =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>

  const 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_address(BIO *b, BIO_ADDR *addr);
  const char *BIO_get_conn_hostname(BIO *b);
  const char *BIO_get_conn_port(BIO *b);
  const BIO_ADDR *BIO_get_conn_address(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; if the address is an IPv6 one, it
 must be enclosed with brackets. The hostname can also include the
 port in the form hostname:port.

 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_address() sets the address and port information using
 a BIO_ADDR(3ssl).

 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.
 This return value is an internal pointer which should not be modified.

 BIO_get_conn_address() returns the address information as a BIO_ADDR.
 This return value is an internal pointer which should not be modified.

 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];

  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

 L<BIO_ADDR(3)>

 =cut
	=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>

	const 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_address(BIO b, BIO_ADDR addr);
	const char BIO_get_conn_hostname(BIO b);
	const char BIO_get_conn_port(BIO b);
	const BIO_ADDR BIO_get_conn_address(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; if the address is an IPv6 one, it
	must be enclosed with brackets. The hostname can also include the
	port in the form hostname:port.

	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_address() sets the address and port information using
	a BIO_ADDR(3ssl).

	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.
	This return value is an internal pointer which should not be modified.

	BIO_get_conn_address() returns the address information as a BIO_ADDR.
	This return value is an internal pointer which should not be modified.

	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];

	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

	L<BIO_ADDR(3)>

	=cut