Ubuntu Manpage: ldap_init, ldap_initialize, ldap_open - Initialize the LDAP library and open a connection to an LDAP

Provided by: libldap-dev_2.6.7+dfsg-1~exp1ubuntu8.2_amd64

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_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;

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_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).

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.
       ldap_set_urllist_proc() returns LDAP_OPT_ERROR on error, and LDAP_OPT_SUCCESS on success.

ACKNOWLEDGEMENTS