1LDAP_OPEN(3) Library Functions Manual LDAP_OPEN(3)
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6 ldap_init, ldap_initialize, ldap_open - Initialize the LDAP library and
7 open a connection to an LDAP server
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10 OpenLDAP LDAP (libldap, -lldap)
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13 #include <ldap.h>
14 LDAP *ldap_open(host, port)
16 char *host;
17 int port;
18 LDAP *ldap_init(host, port)
20 char *host;
21 int port;
22 int ldap_initialize(ldp, uri)
24 LDAP **ldp;
25 char *uri;
26 int ldap_connect(ldp)
28 LDAP *ldp;
29 int ldap_set_urllist_proc(ld, proc, params)
31 LDAP *ld;
32 LDAP_URLLIST_PROC *proc;
33 void *params;
34 int (LDAP_URLLIST_PROC)(ld, urllist, url, params);
36 LDAP *ld;
37 LDAPURLDesc **urllist;
38 LDAPURLDesc **url;
39 void *params;
40 #include <openldap.h>
42 int ldap_init_fd(fd, proto, uri, ldp)
44 ber_socket_t fd;
45 int proto;
46 char *uri;
47 LDAP **ldp;
48
50 ldap_open() opens a connection to an LDAP server and allocates an LDAP
51 structure which is used to identify the connection and to maintain per-
52 connection information. ldap_init() allocates an LDAP structure but
53 does not open an initial connection. ldap_initialize() allocates an
54 LDAP structure but does not open an initial connection. ldap_init_fd()
55 allocates an LDAP structure using an existing connection on the pro‐
56 vided socket. One of these routines must be called before any opera‐
57 tions are attempted.
58 ldap_open() takes host, the hostname on which the LDAP server is run‐
60 ning, and port, the port number to which to connect. If the default
61 IANA-assigned port of 389 is desired, LDAP_PORT should be specified for
62 port. The host parameter may contain a blank-separated list of hosts
63 to try to connect to, and each host may optionally by of the form
64 host:port. If present, the :port overrides the port parameter to
65 ldap_open(). Upon successfully making a connection to an LDAP server,
66 ldap_open() returns a pointer to an opaque LDAP structure, which should
67 be passed to subsequent calls to ldap_bind(), ldap_search(), etc. Cer‐
68 tain fields in the LDAP structure can be set to indicate size limit,
69 time limit, and how aliases are handled during operations; read and
70 write access to those fields must occur by calling ldap_get_option(3)
71 and ldap_set_option(3) respectively, whenever possible.
72 ldap_init() acts just like ldap_open(), but does not open a connection
74 to the LDAP server. The actual connection open will occur when the
75 first operation is attempted.
76 ldap_initialize() acts like ldap_init(), but it returns an integer in‐
78 dicating either success or the failure reason, and it allows to specify
79 details for the connection in the schema portion of the URI. The uri
80 parameter may be a comma- or whitespace-separated list of URIs contain‐
81 ing only the schema, the host, and the port fields. Apart from ldap,
82 other (non-standard) recognized values of the schema field are ldaps
83 (LDAP over TLS), ldapi (LDAP over IPC), and cldap (connectionless
84 LDAP). If other fields are present, the behavior is undefined.
85 At this time, ldap_open() and ldap_init() are deprecated in favor of
87 ldap_initialize(), essentially because the latter allows to specify a
88 schema in the URI and it explicitly returns an error code.
89 ldap_connect() causes a handle created by ldap_initialize() to connect
91 to the server. This is useful in situations where a file descriptor is
92 required before a request is performed.
93 ldap_init_fd() allows an LDAP structure to be initialized using an al‐
95 ready-opened connection. The proto parameter should be one of
96 LDAP_PROTO_TCP, LDAP_PROTO_UDP, or LDAP_PROTO_IPC for a connection us‐
97 ing TCP, UDP, or IPC, respectively. The value LDAP_PROTO_EXT may also
98 be specified if user-supplied sockbuf handlers are going to be used.
99 Note that support for UDP is not implemented unless libldap was built
100 with LDAP_CONNECTIONLESS defined. The uri parameter may optionally be
101 provided for informational purposes.
102 ldap_set_urllist_proc() allows to set a function proc of type LDAP_URL‐
104 LIST_PROC that is called when a successful connection can be estab‐
105 lished. This function receives the list of URIs parsed from the uri
106 string originally passed to ldap_initialize(), and the one that suc‐
107 cessfully connected. The function may manipulate the URI list; the
108 typical use consists in moving the successful URI to the head of the
109 list, so that subsequent attempts to connect to one of the URIs using
110 the same LDAP handle will try it first. If ld is null, proc is set as
111 a global parameter that is inherited by all handlers within the process
112 that are created after the call to ldap_set_urllist_proc(). By de‐
113 fault, no LDAP_URLLIST_PROC is set. In a multithreaded environment,
114 ldap_set_urllist_proc() must be called before any concurrent operation
115 using the LDAP handle is started.
116 Note: the first call into the LDAP library also initializes the global
118 options for the library. As such the first call should be single-
119 threaded or otherwise protected to insure that only one call is active.
120 It is recommended that ldap_get_option() or ldap_set_option() be used
121 in the program's main thread before any additional threads are created.
122 See ldap_get_option(3).
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126 If an error occurs, ldap_open() and ldap_init() will return NULL and
127 errno should be set appropriately. ldap_initialize() and
128 ldap_init_fd() will directly return the LDAP code associated to the er‐
129 ror (or LDAP_SUCCESS in case of success); errno should be set as well
130 whenever appropriate. ldap_set_urllist_proc() returns LDAP_OPT_ERROR
131 on error, and LDAP_OPT_SUCCESS on success.
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134 ldap(3), ldap_bind(3), ldap_get_option(3), ldap_set_option(3), lber-
135 sockbuf(3), errno(3)
136
138 OpenLDAP Software is developed and maintained by The OpenLDAP Project
139 <http://www.openldap.org/>. OpenLDAP Software is derived from the Uni‐
140 versity of Michigan LDAP 3.3 Release.
141OpenLDAP 2.6.6 2023/07/31 LDAP_OPEN(3)