BIO_s_connect(3)
- NetBSD Manual Pages
BIO_s_connect(3) OpenSSL BIO_s_connect(3)
NAME
BIO_s_connect, BIO_set_conn_hostname, BIO_set_conn_port,
BIO_set_conn_ip, BIO_set_conn_int_port, BIO_get_conn_host-
name, BIO_get_conn_port, BIO_get_conn_ip,
BIO_get_conn_int_port, BIO_set_nbio, BIO_do_connect - con-
nect BIO
LIBRARY
libcrypto, -lcrypto
SYNOPSIS
#include <openssl/bio.h>
BIO_METHOD * BIO_s_connect(void);
#define BIO_set_conn_hostname(b,name) BIO_ctrl(b,BIO_C_SET_CONNECT,0,(char *)name)
#define BIO_set_conn_port(b,port) BIO_ctrl(b,BIO_C_SET_CONNECT,1,(char *)port)
#define BIO_set_conn_ip(b,ip) BIO_ctrl(b,BIO_C_SET_CONNECT,2,(char *)ip)
#define BIO_set_conn_int_port(b,port) BIO_ctrl(b,BIO_C_SET_CONNECT,3,(char *)port)
#define BIO_get_conn_hostname(b) BIO_ptr_ctrl(b,BIO_C_GET_CONNECT,0)
#define BIO_get_conn_port(b) BIO_ptr_ctrl(b,BIO_C_GET_CONNECT,1)
#define BIO_get_conn_ip(b,ip) BIO_ptr_ctrl(b,BIO_C_SET_CONNECT,2)
#define BIO_get_conn_int_port(b,port) BIO_int_ctrl(b,BIO_C_SET_CONNECT,3,port)
#define BIO_set_nbio(b,n) BIO_ctrl(b,BIO_C_SET_NBIO,(n),NULL)
#define BIO_do_connect(b) BIO_do_handshake(b)
DESCRIPTION
BIO_s_connect() returns the connect BIO method. This is a
wrapper round the platform's TCP/IP socket connection rou-
tines.
Using connect BIOs TCP/IP connections can be made and data
transferred using only BIO routines. In this way any plat-
form specific operations are hidden by the BIO abstrac-
tion.
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.
2001-04-12 0.9.6g 1
BIO_s_connect(3) OpenSSL BIO_s_connect(3)
BIO_get_fd() places the underlying socket in c if it is
not NULL, it also returns the socket . If c is not NULL it
should be of type (int *).
BIO_set_conn_hostname() uses the string 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 "host-
name/any/other/path" or "hostname:port/any/other/path".
BIO_set_conn_port() sets the port to port. port can be the
numerical form or a string such as "http". A string will
be looked up first using getservbyname() on the host plat-
form but if that fails a standard table of port names will
be used. Currently the list is http, telnet, socks, https,
ssl, ftp, gopher and wais.
BIO_set_conn_ip() sets the IP address to 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 port. port
should be of type (int *).
BIO_get_conn_hostname() returns the hostname of the con-
nect 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 n. If n
is zero then blocking I/O is set. If 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_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.
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 connec-
tion was closed.
2001-04-12 0.9.6g 2
BIO_s_connect(3) OpenSSL BIO_s_connect(3)
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 indi-
cation that a connection attempt would block, the applica-
tion should then take appropriate action to wait until the
underlying socket has connected and retry the call.
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 con-
nected 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
2001-04-12 0.9.6g 3
BIO_s_connect(3) OpenSSL BIO_s_connect(3)
successfully established and 0 or -1 if the connection
failed.
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);
SEE ALSO
TBA
2001-04-12 0.9.6g 4
Powered by man-cgi (2024-03-20).
Maintained for NetBSD
by Kimmo Suominen.
Based on man-cgi by Panagiotis Christias.