Tribblix: manual page: cldap_search

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(4P).
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