Back to main site | Back to man page index

LDAP_OPEN(3)                                   Library Functions Manual                                  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;

       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 <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 con‐
       nection.  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  success‐
       fully  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.
       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 param‐
       eter  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 success‐
       ful  connection can be established.  This function receives the list of URIs parsed from the uri string origi‐
       nally 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 rec‐
       ommended  that  ldap_get_option()  or  ldap_set_option() be used in the program's main thread before any addi‐
       tional 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_SUC‐
       CESS 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.

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.



OpenLDAP 2.4.40                                       2014/09/20                                         LDAP_OPEN(3)