BIO_get_conn_ip(3)

BIO_s_connect(3)             OpenSSL             BIO_s_connect(3)

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

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);

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.

1.0.2t               Last change: 2019-09-10                    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 "hostname/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 platform
     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 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 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_new_connect() combines BIO_new() and
     BIO_set_conn_hostname() into a single call: that is it
     creates a new connect BIO with 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.

1.0.2t               Last change: 2019-09-10                    2

BIO_s_connect(3)             OpenSSL             BIO_s_connect(3)

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.

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.

1.0.2t               Last change: 2019-09-10                    3

BIO_s_connect(3)             OpenSSL             BIO_s_connect(3)

     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.

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

1.0.2t               Last change: 2019-09-10                    4