CLDAP_SEARCH_S(3LDAP) LDAP Library Functions CLDAP_SEARCH_S(3LDAP)


NAME


cldap_search_s - connectionless LDAP search

SYNOPSIS


cc[ flag... ] file... -lldap[ library... ]
#include <lber.h>
#include <ldap.h>

int cldap_search_s(LDAP *ld, char *base, int scope, char *filter,
char *attrs, int attrsonly, LDAPMessage **res, char *logdn);


DESCRIPTION


The cldap_search_s() function performs an LDAP search using the
Connectionless LDAP (CLDAP) protocol.


cldap_search_s() has parameters and behavior identical to that of
ldap_search_s(3LDAP), except for the addition of the logdn parameter.
logdn should contain a distinguished name to be used only for logging
purposed by the LDAP server. It should be in the text format described
by RFC 1779, A String Representation of Distinguished Names.

Retransmission Algorithm


cldap_search_s() operates using the CLDAP protocol over udp(7P). Since
UDP is a non-reliable protocol, a retry mechanism is used to increase
reliability. The cldap_setretryinfo(3LDAP) function can be used to set
two retry parameters: tries, a count of the number of times to send a
search request and timeout, an initial timeout that determines how long
to wait for a response before re-trying. timeout is specified seconds.
These values are stored in the ld_cldaptries and ld_cldaptimeout members
of the ld LDAP structure, and the default values set in ldap_open(3LDAP)
are 4 and 3 respectively. The retransmission algorithm used is:

Step 1
Set the current timeout to ld_cldaptimeout seconds, and the
current LDAP server address to the first LDAP server found
during the ldap_open(3LDAP) call.


Step 2
Send the search request to the current LDAP server address.


Step 3
Set the wait timeout to the current timeout divided by the
number of server addresses found during ldap_open(3LDAP) or to
one second, whichever is larger. Wait at most that long for a
response; if a response is received, STOP. Note that the wait
timeout is always rounded down to the next lowest second.


Step 4
Repeat steps 2 and 3 for each LDAP server address.


Step 5
Set the current timeout to twice its previous value and repeat
Steps 2 through 5 a maximum of tries times.


EXAMPLES


Assume that the default values for tries and timeout of 4 tries and 3
seconds are used. Further, assume that a space-separated list of two
hosts, each with one address, was passed to cldap_open(3LDAP). The
pattern of requests sent will be (stopping as soon as a response is
received):

Time Search Request Sent To:
+0 Host A try 1
+1 (0+3/2) Host B try 1
+2 (1+3/2) Host A try 2
+5 (2+6/2) Host B try 2
+8 (5+6/2) Host A try 3
+14 (8+12/2) Host B try 3
+20 (14+12/2) Host A try 4
+32 (20+24/2) Host B try 4
+44 (20+24/2) (give up - no response)


ERRORS


cldap_search_s() returns LDAP_SUCCESS if a search was successful and the
appropriate LDAP error code otherwise. See ldap_error(3LDAP) for more
information.

ATTRIBUTES


See attributes(5) for a description of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|Interface Stability | Evolving |
+--------------------+-----------------+

SEE ALSO


ldap(3LDAP), ldap_error(3LDAP), ldap_search_s(3LDAP), cldap_open(3LDAP),
cldap_setretryinfo(3LDAP), cldap_close(3LDAP), attributes(5), udp(7P)


January 27, 2002 CLDAP_SEARCH_S(3LDAP)