ldap_init, ldap_initialize, ldap_open - Initialize the LDAP library and open a
connection to an LDAP server
OpenLDAP LDAP (libldap, -lldap)
#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;
int ldap_connect(ldp)
LDAP *ldp;
int ldap_set_urllist_proc(ld, proc, params)
LDAP *ld;
LDAP_URLLIST_PROC *proc;
void *params;
int (LDAP_URLLIST_PROC)(ld, urllist, url, params);
LDAP *ld;
LDAPURLDesc **urllist;
LDAPURLDesc **url;
void *params;
#include <openldap.h>
int ldap_init_fd(fd, proto, uri, ldp)
ber_socket_t fd;
int proto;
char *uri;
LDAP **ldp;
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_connect() causes a handle created by
ldap_initialize() to
connect to the server. This is useful in situations where a file descriptor is
required before a request is performed.
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.
ldap_set_urllist_proc() allows to set a function
proc of type
LDAP_URLLIST_PROC that is called when a successful connection can be
established. This function receives the list of URIs parsed from the
uri string originally passed to
ldap_initialize(), and the one
that successfully connected. The function may manipulate the URI list; the
typical use consists in moving the successful URI to the head of the list, so
that subsequent attempts to connect to one of the URIs using the same LDAP
handle will try it first. If
ld is null,
proc is set as a global
parameter that is inherited by all handlers within the process that are
created after the call to
ldap_set_urllist_proc(). By default, no
LDAP_URLLIST_PROC is set. In a multithreaded environment,
ldap_set_urllist_proc() must be called before any concurrent operation
using the LDAP handle is started.
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).
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.
ldap_set_urllist_proc() returns
LDAP_OPT_ERROR on error, and LDAP_OPT_SUCCESS on success.
ldap(3),
ldap_bind(3),
ldap_get_option(3),
ldap_set_option(3),
lber-sockbuf(3),
errno(3)
OpenLDAP Software is developed and maintained by The OpenLDAP Project
<
http://www.openldap.org/>.
OpenLDAP Software is derived from the
University of Michigan LDAP 3.3 Release.