LDAP_OPEN(3) |  | LDAP_OPEN(3)

# NAME

ldap_init, ldap_initialize, ldap_open - Initialize the LDAP library and open a connection to an LDAP server

# LIBRARY

OpenLDAP LDAP (libldap, -lldap)

# SYNOPSIS

#include <ldap.h>

LDAP *ldap_open(host, port)
char *host;
int port;

LDAP *ldap_init(host, port)
char *host;
int port;

int ldap_initialize(ldp, uri)
LDAP **ldp;
char *uri;

#include <ldap_pvt.h>

int ldap_init_fd(fd, proto, uri, ldp)
ber_socket_t fd;
int proto;
char *uri;
LDAP **ldp;

# DESCRIPTION

ldap_open()
opens a connection to an LDAP server and allocates an LDAP
structure which is used to identify
the connection and to maintain per-connection information.
ldap_init()
allocates an LDAP structure but does not open an initial connection.
ldap_initialize()
allocates an LDAP structure but does not open an initial connection.
ldap_init_fd()
allocates an LDAP structure using an existing connection on the
provided socket.
One
of these routines must be called before any operations are attempted.

ldap_open()
takes host, the hostname on which the LDAP server is
running, and port, the port number to which to connect. If the default
IANA-assigned port of 389 is desired, LDAP_PORT should be specified for
port. The host parameter may contain a blank-separated list
of hosts to try to connect to, and each host may optionally by of the form
host:port. If present, the :port overrides the port
parameter to
ldap_open().
Upon successfully making a connection to an
LDAP server,
ldap_open()
returns a pointer to an opaque LDAP structure, which should be passed
to subsequent calls to
ldap_bind(),
ldap_search(),
etc. Certain fields in the LDAP structure can be set to indicate size limit,
time limit, and how aliases are handled during operations; read and write access
to those fields must occur by calling
ldap_get_option(3)
and
ldap_set_option(3)
respectively, whenever possible.

ldap_init()
acts just like
ldap_open(),
but does not open a connection
to the LDAP server. The actual connection open will occur when the
first operation is attempted.

ldap_initialize()
acts like
ldap_init(),
but it returns an integer indicating either success or the failure reason,
and it allows to specify details for the connection in the schema portion
of the URI.
The
uri
parameter may be a comma- or whitespace-separated list of URIs
containing only the
schema,
the
host,
and the
port
fields.
Apart from
ldap,
other (non-standard) recognized values of the
schema
field are
ldaps
(LDAP over TLS),
ldapi
(LDAP over IPC),
and
cldap
(connectionless LDAP).
If other fields are present, the behavior is undefined.

At this time,
ldap_open()
and
ldap_init()
are deprecated in favor of
ldap_initialize(),
essentially because the latter allows to specify a schema in the URI
and it explicitly returns an error code.

ldap_init_fd()
allows an LDAP structure to be initialized using an already-opened
connection. The
proto
parameter should be one of LDAP_PROTO_TCP, LDAP_PROTO_UDP,
or LDAP_PROTO_IPC
for a connection using TCP, UDP, or IPC, respectively. The value
LDAP_PROTO_EXT
may also be specified if user-supplied sockbuf handlers are going to
be used. Note that support for UDP is not implemented unless libldap
was built with LDAP_CONNECTIONLESS defined.
The
uri
parameter may optionally be provided for informational purposes.

Note: the first call into the LDAP library also initializes the global
options for the library. As such the first call should be single-threaded
or otherwise protected to insure that only one call is active. It is
recommended that
ldap_get_option()
or
ldap_set_option()
be used in the program's main thread before any additional threads are created.
See
ldap_get_option(3).

# ERRORS

If an error occurs,
ldap_open()
and
ldap_init()
will return NULL and
errno
should be set appropriately.
ldap_initialize()
and
ldap_init_fd()
will directly return the LDAP code associated to the error (or
LDAP_SUCCESS
in case of success);
errno
should be set as well whenever appropriate.

# SEE ALSO

ldap(3),
ldap_bind(3),
ldap_get_option(3),
ldap_set_option(3),
lber-sockbuf(3),
errno(3)

# ACKNOWLEDGEMENTS

OpenLDAP Software
is developed and maintained by The OpenLDAP Project <http://www.openldap.org/>.
OpenLDAP Software
is derived from University of Michigan LDAP 3.3 Release.

2010/06/30 | OpenLDAP 2.4.23