1 .TH SLAPD-META 5 "RELEASEDATE" "OpenLDAP LDVERSION"
2 .\" Copyright 1998-2005 The OpenLDAP Foundation, All Rights Reserved.
3 .\" Copying restrictions apply. See the COPYRIGHT file.
4 .\" Copyright 2001, Pierangelo Masarati, All rights reserved. <ando@sys-net.it>
7 .\" Portions of this document should probably be moved to slapd-ldap(5)
8 .\" and maybe manual pages for librewrite.
11 slapd-meta \- metadirectory backend
19 performs basic LDAP proxying with respect to a set of remote LDAP
20 servers, called "targets".
21 The information contained in these servers can be presented as
22 belonging to a single Directory Information Tree (DIT).
24 A basic knowledge of the functionality of the
26 backend is recommended.
27 This backend has been designed as an enhancement of the ldap backend.
28 The two backends share many features (actually they also share
32 backend is intended to proxy operations directed to a single server, the
34 backend is mainly intended for proxying of multiple servers and possibly
35 naming context masquerading.
36 These features, although useful in many scenarios, may result in
37 excessive overhead for some applications, so its use should be
39 In the examples section, some typical scenarios will be discussed.
41 There are examples in various places in this document, as well as in the
42 slapd/back-meta/data/ directory in the OpenLDAP source tree.
46 options apply to the META backend database.
47 That is, they must follow a "database meta" line and come before any
48 subsequent "backend" or "database" lines.
49 Other database options are described in the
55 backend, operational attributes related to entry creation/modification
56 should not be used, as they would be passed to the target servers,
58 Moreover, it makes little sense to use such attributes in proxying, as
59 the proxy server doesn't actually store data, so it should have no
60 knowledge of such attributes.
61 While code to strip the modification attributes has been put in place
62 (and #ifdef'd), it implies unmotivated overhead.
63 So it is strongly recommended to set
72 .SH SPECIAL CONFIGURATION DIRECTIVES
73 Target configuration starts with the "uri" directive.
74 All the configuration directives that are not specific to targets
75 should be defined first for clarity, including those that are common
79 .B default-target none
80 This directive forces the backend to reject all those operations
81 that must resolve to a single target in case none or multiple
83 They include: add, delete, modify, modrdn; compare is not included, as
84 well as bind since, as they don't alter entries, in case of multiple
85 matches an attempt is made to perform the operation on any candidate
86 target, with the constraint that at most one must succeed.
87 This directive can also be used when processing targets to mark a
88 specific target as default.
90 .B dncache-ttl {forever|disabled|<ttl>}
91 This directive sets the time-to-live of the DN cache.
92 This caches the target that holds a given DN to speed up target
93 selection in case multiple targets would result from an uncached
94 search; forever means cache never expires; disabled means no DN
95 caching; otherwise a valid ( > 0 ) ttl in seconds is required.
96 .SH TARGET SPECIFICATION
97 Target specification starts with a "uri" directive:
99 .B uri <protocol>://[<host>[:<port>]]/<naming context>
100 The "server" directive that was allowed in the LDAP backend (although
101 deprecated) has been completely discarded in the Meta backend.
102 The <protocol> part can be anything
103 .BR ldap_initialize (3)
104 accepts ({ldap|ldaps|ldapi} and variants); <host> and <port> may be
105 omitted, defaulting to whatever is set in
107 The <naming context> part is mandatory.
108 It must end with one of the naming contexts defined for the backend,
113 suffix "\fBdc=foo,dc=com\fP"
114 uri "ldap://x.foo.com/dc=x,\fBdc=foo,dc=com\fP"
119 The <naming context> part doesn't need to be unique across the targets;
120 it may also match one of the values of the "suffix" directive.
121 Multiple URIs may be defined in a single argument. The URIs must
122 be separated by TABs (e.g. '\\t'; commas or spaces, unlike back-ldap,
124 because they are legal in the <naming context>, and we don't want to use
125 URL-encoded <namimg context>s), and the additional URIs must have
126 no <naming context> part. This causes the underlying library
127 to contact the first server of the list that responds.
130 .B default-target [<target>]
131 The "default-target" directive can also be used during target specification.
132 With no arguments it marks the current target as the default.
133 The optional number marks target <target> as the default one, starting
135 Target <target> must be defined.
137 .B acl-authcDN "<administrative DN for access control purposes>"
138 DN which is used to query the target server for acl checking,
139 as in the LDAP backend; it is supposed to have read access
140 on the target server to attributes used on the proxy for acl checking.
141 There is no risk of giving away such values; they are only used to
143 .B The acl-authcDN identity is by no means implicitly used by the proxy
144 .B when the client connects anonymously.
146 .B acl-passwd <password>
147 Password used with the
153 If this option is given, the client's bind credentials are remembered
154 for rebinds when chasing referrals.
156 .B pseudorootdn "<substitute DN in case of rootdn bind>"
157 This directive, if present, sets the DN that will be substituted to
158 the bind DN if a bind with the backend's "rootdn" succeeds.
159 The true "rootdn" of the target server ought not be used; an arbitrary
160 administrative DN should used instead.
162 .B pseudorootpw "<substitute password in case of rootdn bind>"
163 This directive sets the credential that will be used in case a bind
164 with the backend's "rootdn" succeeds, and the bind is propagated to
165 the target using the "pseudorootdn" DN.
167 Note: cleartext credentials must be supplied here; as a consequence,
168 using the pseudorootdn/pseudorootpw directives is inherently unsafe.
171 The rewrite options are described in the "REWRITING" section.
173 .B suffixmassage "<virtual naming context>" "<real naming context>"
174 All the directives starting with "rewrite" refer to the rewrite engine
175 that has been added to slapd.
176 The "suffixmassage" directive was introduced in the LDAP backend to
177 allow suffix massaging while proxying.
178 It has been obsoleted by the rewriting tools.
179 However, both for backward compatibility and for ease of configuration
180 when simple suffix massage is required, it has been preserved.
181 It wraps the basic rewriting instructions that perform suffix
182 massaging. See the "REWRITING" section for a detailed list
183 of the rewrite rules it implies.
185 Note: this also fixes a flaw in suffix massaging, which operated
186 on (case insensitive) DNs instead of normalized DNs,
187 so "dc=foo, dc=com" would not match "dc=foo,dc=com".
189 See the "REWRITING" section.
191 .B map "{attribute|objectclass} [<local name>|*] {<foreign name>|*}"
192 This maps object classes and attributes as in the LDAP backend.
196 A powerful (and in some sense dangerous) rewrite engine has been added
197 to both the LDAP and Meta backends.
198 While the former can gain limited beneficial effects from rewriting
199 stuff, the latter can become an amazingly powerful tool.
201 Consider a couple of scenarios first.
203 1) Two directory servers share two levels of naming context;
204 say "dc=a,dc=foo,dc=com" and "dc=b,dc=foo,dc=com".
205 Then, an unambiguous Meta database can be configured as:
210 suffix "\fBdc=foo,dc=com\fP"
211 uri "ldap://a.foo.com/dc=a,\fBdc=foo,dc=com\fP"
212 uri "ldap://b.foo.com/dc=b,\fBdc=foo,dc=com\fP"
216 Operations directed to a specific target can be easily resolved
217 because there are no ambiguities.
218 The only operation that may resolve to multiple targets is a search
219 with base "dc=foo,dc=com" and scope at least "one", which results in
220 spawning two searches to the targets.
222 2a) Two directory servers don't share any portion of naming context,
223 but they'd present as a single DIT
224 [Caveat: uniqueness of (massaged) entries among the two servers is
225 assumed; integrity checks risk to incur in excessive overhead and have
226 not been implemented].
227 Say we have "dc=bar,dc=org" and "o=Foo,c=US",
228 and we'd like them to appear as branches of "dc=foo,dc=com", say
229 "dc=a,dc=foo,dc=com" and "dc=b,dc=foo,dc=com".
230 Then we need to configure our Meta backend as:
235 suffix "dc=foo,dc=com"
237 uri "ldap://a.bar.com/\fBdc=a,dc=foo,dc=com\fP"
238 suffixmassage "\fBdc=a,dc=foo,dc=com\fP" "dc=bar,dc=org"
240 uri "ldap://b.foo.com/\fBdc=b,dc=foo,dc=com\fP"
241 suffixmassage "\fBdc=b,dc=foo,dc=com\fP" "o=Foo,c=US"
245 Again, operations can be resolved without ambiguity, although
246 some rewriting is required.
247 Notice that the virtual naming context of each target is a branch of
248 the database's naming context; it is rewritten back and forth when
249 operations are performed towards the target servers.
250 What "back and forth" means will be clarified later.
252 When a search with base "dc=foo,dc=com" is attempted, if the
253 scope is "base" it fails with "no such object"; in fact, the
254 common root of the two targets (prior to massaging) does not
256 If the scope is "one", both targets are contacted with the base
257 replaced by each target's base; the scope is derated to "base".
258 In general, a scope "one" search is honored, and the scope is derated,
259 only when the incoming base is at most one level lower of a target's
260 naming context (prior to massaging).
262 Finally, if the scope is "sub" the incoming base is replaced
263 by each target's unmassaged naming context, and the scope
266 2b) Consider the above reported scenario with the two servers
267 sharing the same naming context:
272 suffix "\fBdc=foo,dc=com\fP"
274 uri "ldap://a.bar.com/\fBdc=foo,dc=com\fP"
275 suffixmassage "\fBdc=foo,dc=com\fP" "dc=bar,dc=org"
277 uri "ldap://b.foo.com/\fBdc=foo,dc=com\fP"
278 suffixmassage "\fBdc=foo,dc=com\fP" "o=Foo,c=US"
282 All the previous considerations hold, except that now there is
283 no way to unambiguously resolve a DN.
284 In this case, all the operations that require an unambiguous target
285 selection will fail unless the DN is already cached or a default
287 Practical configurations may result as a combination of all the
290 Note on ACLs: at present you may add whatever ACL rule you desire
291 to to the Meta (and LDAP) backends.
292 However, the meaning of an ACL on a proxy may require some
294 Two philosophies may be considered:
296 a) the remote server dictates the permissions; the proxy simply passes
297 back what it gets from the remote server.
299 b) the remote server unveils "everything"; the proxy is responsible
300 for protecting data from unauthorized access.
302 Of course the latter sounds unreasonable, but it is not.
303 It is possible to imagine scenarios in which a remote host discloses
304 data that can be considered "public" inside an intranet, and a proxy
305 that connects it to the internet may impose additional constraints.
306 To this purpose, the proxy should be able to comply with all the ACL
307 matching criteria that the server supports.
308 This has been achieved with regard to all the criteria supported by
309 slapd except a special subtle case (please drop me a note if you can
310 find other exceptions: <ando@openldap.org>).
315 access to dn="<dn>" attr=<attr>
316 by dnattr=<dnattr> read
321 cannot be matched iff the attribute that is being requested, <attr>,
322 is NOT <dnattr>, and the attribute that determines membership,
323 <dnattr>, has not been requested (e.g. in a search)
325 In fact this ACL is resolved by slapd using the portion of entry it
326 retrieved from the remote server without requiring any further
327 intervention of the backend, so, if the <dnattr> attribute has not
328 been fetched, the match cannot be assessed because the attribute is
329 not present, not because no value matches the requirement!
331 Note on ACLs and attribute mapping: ACLs are applied to the mapped
332 attributes; for instance, if the attribute locally known as "foo" is
333 mapped to "bar" on a remote server, then local ACLs apply to attribute
334 "foo" and are totally unaware of its remote name.
335 The remote server will check permissions for "bar", and the local
336 server will possibly enforce additional restrictions to "foo".
338 .\" If this section is moved, also update the reference in
339 .\" libraries/librewrite/RATIONALE.
342 A string is rewritten according to a set of rules, called a `rewrite
344 The rules are based on POSIX (''extended'') regular expressions (regex)
345 with substring matching; basic variable substitution and map resolution
346 of substrings is allowed by specific mechanisms detailed in the following.
347 The behavior of pattern matching/substitution can be altered by a set
350 The underlying concept is to build a lightweight rewrite module
351 for the slapd server (initially dedicated to the LDAP backend).
353 An incoming string is matched agains a set of rules.
354 Rules are made of a regex match pattern, a substitution pattern
355 and a set of actions, described by a set of flags.
356 In case of match a string rewriting is performed according to the
357 substitution pattern that allows to refer to substrings matched in the
359 The actions, if any, are finally performed.
360 The substitution pattern allows map resolution of substrings.
361 A map is a generic object that maps a substitution pattern to a value.
362 The flags are divided in "Pattern matching Flags" and "Action Flags";
363 the former alter the regex match pattern behaviorm while the latter
364 alter the action that is taken after substitution.
365 .SH "Pattern Matching Flags"
368 honors case in matching (default is case insensitive)
371 use POSIX ''basic'' regular expressions (default is ''extended'')
376 recursive passes for a specific rule; does not alter the max total count
377 of passes, so it can only enforce a stricter limit for a specific rule.
381 apply the rule once only (default is recursive)
384 stop applying rules in case of match; the current rule is still applied
385 recursively; combine with `:' to apply the current rule only once
389 stop current operation if the rule matches, and issue an `unwilling to
395 rules back and forth (watch for loops!).
396 Note that `G{1}' is implicit in every rule.
399 ignores errors in rule; this means, in case of error, e.g. issued by a
400 map, the error is treated as a missed match.
401 The `unwilling to perform' is not overridden.
407 as return code if the rule matches; the flag does not alter the recursive
408 behavior of the rule, so, to have it performed only once, it must be used
409 in combination with `:', e.g.
411 returns the value `16' after exactly one execution of the rule, if the
413 As a consequence, its behavior is equivalent to `@', with the return
416 or, in other words, `@' is equivalent to `U{0}'.
417 By convention, the freely available codes are above 16 included;
418 the others are reserved.
420 The ordering of the flags can be significant.
421 For instance: `IG{2}' means ignore errors and jump two lines ahead
422 both in case of match and in case of error, while `G{2}I' means ignore
423 errors, but jump two lines ahead only in case of match.
425 More flags (mainly Action Flags) will be added as needed.
426 .SH "Pattern matching:"
431 .SH "Substitution Pattern Syntax:"
432 Everything starting with `%' requires substitution;
434 the only obvious exception is `%%', which is left as is;
436 the basic substitution is `%d', where `d' is a digit;
437 0 means the whole string, while 1-9 is a submatch;
439 a `%' followed by a `{' invokes an advanced substitution.
443 `%' `{' [ <op> ] <name> `(' <substitution> `)' `}'
446 where <name> must be a legal name for the map, i.e.
450 <name> ::= [a-z][a-z0-9]* (case insensitive)
451 <op> ::= `>' `|' `&' `&&' `*' `**' `$'
455 and <substitution> must be a legal substitution
456 pattern, with no limits on the nesting level.
461 sub context invocation; <name> must be a legal, already defined
465 external command invocation; <name> must refer to a legal, already
466 defined command name (NOT IMPL.)
469 variable assignment; <name> defines a variable in the running
470 operation structure which can be dereferenced later; operator
472 assigns a variable in the rewrite context scope; operator
474 assigns a variable that scopes the entire session, e.g. its value
475 can be derefenced later by other rewrite contexts
478 variable dereferencing; <name> must refer to a variable that is
479 defined and assigned for the running operation; operator
481 dereferences a variable scoping the rewrite context; operator
483 dereferences a variable scoping the whole session, e.g. the value
484 is passed across rewrite contexts
487 parameter dereferencing; <name> must refer to an existing parameter;
488 the idea is to make some run-time parameters set by the system
489 available to the rewrite engine, as the client host name, the bind DN
490 if any, constant parameters initialized at config time, and so on;
491 no parameter is currently set by either
495 but constant parameters can be defined in the configuration file
500 Substitution escaping has been delegated to the `%' symbol,
501 which is used instead of `\e' in string substitution patterns
502 because `\e' is already escaped by slapd's low level parsing routines;
503 as a consequence, regex escaping requires two `\e' symbols,
504 e.g. `\fB.*\e.foo\e.bar\fP' must be written as `\fB.*\e\e.foo\e\e.bar\fP'.
506 .\" The symbol can be altered at will by redefining the related macro in
509 .SH "Rewrite context:"
510 A rewrite context is a set of rules which are applied in sequence.
511 The basic idea is to have an application initialize a rewrite
512 engine (think of Apache's mod_rewrite ...) with a set of rewrite
513 contexts; when string rewriting is required, one invokes the
514 appropriate rewrite context with the input string and obtains the
515 newly rewritten one if no errors occur.
517 Each basic server operation is associated to a rewrite context;
518 they are divided in two main groups: client \-> server and
519 server \-> client rewriting.
525 (default) if defined and no specific context
530 searchFilterAttrDN search
532 compareAttrDN compare AVA
536 modifyAttrDN modify AVA
540 exopPasswdDN passwd exop DN if proxy
548 searchResult search (only if defined; no default;
549 acts on DN and DN-syntax attributes
551 searchAttrDN search AVA
552 matchedDN all ops (only if applicable)
556 .SH "Basic configuration syntax"
558 .B rewriteEngine { on | off }
559 If `on', the requested rewriting is performed; if `off', no
560 rewriting takes place (an easy way to stop rewriting without
561 altering too much the configuration file).
563 .B rewriteContext <context name> "[ alias <aliased context name> ]"
564 <Context name> is the name that identifies the context, i.e. the name
565 used by the application to refer to the set of rules it contains.
566 It is used also to reference sub contexts in string rewriting.
567 A context may aliase another one.
568 In this case the alias context contains no rule, and any reference to
569 it will result in accessing the aliased one.
571 .B rewriteRule "<regex match pattern>" "<substitution pattern>" "[ <flags> ]"
572 Determines how a string can be rewritten if a pattern is matched.
573 Examples are reported below.
574 .SH "Additional configuration syntax:"
576 .B rewriteMap "<map type>" "<map name>" "[ <map attrs> ]"
577 Allows to define a map that transforms substring rewriting into
579 The map is referenced inside the substitution pattern of a rule.
581 .B rewriteParam <param name> <param value>
582 Sets a value with global scope, that can be dereferenced by the
583 command `%{$paramName}'.
585 .B rewriteMaxPasses <number of passes> [<number of passes per rule>]
586 Sets the maximum number of total rewriting passes that can be
587 performed in a single rewrite operation (to avoid loops).
588 A safe default is set to 100; note that reaching this limit is still
589 treated as a success; recursive invocation of rules is simply
591 The count applies to the rewriting operation as a whole, not
592 to any single rule; an optional per-rule limit can be set.
593 This limit is overridden by setting specific per-rule limits
594 with the `M{n}' flag.
595 .SH "Configuration examples:"
597 # set to `off' to disable rewriting
600 # the rules the "suffixmassage" directive implies
602 # all dataflow from client to server referring to DNs
603 rewriteContext default
604 rewriteRule "(.*)<virtualnamingcontext>$" "%1<realnamingcontext>" ":"
606 rewriteContext searchFilter
607 # all dataflow from server to client
608 rewriteContext searchResult
609 rewriteRule "(.*)<realnamingcontext>$" "%1<virtualnamingcontext>" ":"
610 rewriteContext searchAttrDN alias searchResult
611 rewriteContext matchedDN alias searchResult
613 # Everything defined here goes into the `default' context.
614 # This rule changes the naming context of anything sent
615 # to `dc=home,dc=net' to `dc=OpenLDAP, dc=org'
617 rewriteRule "(.*)dc=home,[ ]?dc=net"
618 "%1dc=OpenLDAP, dc=org" ":"
620 # since a pretty/normalized DN does not include spaces
621 # after rdn separators, e.g. `,', this rule suffices:
623 rewriteRule "(.*)dc=home,dc=net"
624 "%1dc=OpenLDAP,dc=org" ":"
626 # Start a new context (ends input of the previous one).
627 # This rule adds blanks between DN parts if not present.
628 rewriteContext addBlanks
629 rewriteRule "(.*),([^ ].*)" "%1, %2"
631 # This one eats blanks
632 rewriteContext eatBlanks
633 rewriteRule "(.*),[ ](.*)" "%1,%2"
635 # Here control goes back to the default rewrite
636 # context; rules are appended to the existing ones.
637 # anything that gets here is piped into rule `addBlanks'
638 rewriteContext default
639 rewriteRule ".*" "%{>addBlanks(%0)}" ":"
641 .\" # Anything with `uid=username' is looked up in
642 .\" # /etc/passwd for gecos (I know it's nearly useless,
643 .\" # but it is there just as a guideline to implementing
645 .\" # Note the `I' flag that leaves `uid=username' in place
646 .\" # if `username' does not have a valid account, and the
647 .\" # `:' that forces the rule to be processed exactly once.
648 .\" rewriteContext uid2Gecos
649 .\" rewriteRule "(.*)uid=([a-z0-9]+),(.+)"
650 .\" "%1cn=%2{xpasswd},%3" "I:"
652 .\" # Finally, in a bind, if one uses a `uid=username' DN,
653 .\" # it is rewritten in `cn=name surname' if possible.
654 .\" rewriteContext bindDN
655 .\" rewriteRule ".*" "%{>addBlanks(%{>uid2Gecos(%0)})}" ":"
657 # Rewrite the search base according to `default' rules.
658 rewriteContext searchBase alias default
660 # Search results with OpenLDAP DN are rewritten back with
661 # `dc=home,dc=net' naming context, with spaces eaten.
662 rewriteContext searchResult
663 rewriteRule "(.*[^ ]?)[ ]?dc=OpenLDAP,[ ]?dc=org"
664 "%{>eatBlanks(%1)}dc=home,dc=net" ":"
666 # Bind with email instead of full DN: we first need
667 # an ldap map that turns attributes into a DN (the
668 # argument used when invoking the map is appended to
669 # the URI and acts as the filter portion)
670 rewriteMap ldap attr2dn "ldap://host/dc=my,dc=org?dn?sub"
672 # Then we need to detect DN made up of a single email,
673 # e.g. `mail=someone@example.com'; note that the rule
674 # in case of match stops rewriting; in case of error,
675 # it is ignored. In case we are mapping virtual
676 # to real naming contexts, we also need to rewrite
677 # regular DNs, because the definition of a bindDn
678 # rewrite context overrides the default definition.
679 rewriteContext bindDN
680 rewriteRule "^mail=[^,]+@[^,]+$" "%{attr2dn(%0)}" ":@I"
682 # This is a rather sophisticated example. It massages a
683 # search filter in case who performs the search has
684 # administrative privileges. First we need to keep
685 # track of the bind DN of the incoming request, which is
686 # stored in a variable called `binddn' with session scope,
687 # and left in place to allow regular binding:
688 rewriteContext bindDN
689 rewriteRule ".+" "%{&&binddn(%0)}%0" ":"
691 # A search filter containing `uid=' is rewritten only
692 # if an appropriate DN is bound.
693 # To do this, in the first rule the bound DN is
694 # dereferenced, while the filter is decomposed in a
695 # prefix, in the value of the `uid=<arg>' AVA, and
696 # in a suffix. A tag `<>' is appended to the DN.
697 # If the DN refers to an entry in the `ou=admin' subtree,
698 # the filter is rewritten OR-ing the `uid=<arg>' with
699 # `cn=<arg>'; otherwise it is left as is. This could be
700 # useful, for instance, to allow apache's auth_ldap-1.4
701 # module to authenticate users with both `uid' and
702 # `cn', but only if the request comes from a possible
703 # `cn=Web auth,ou=admin,dc=home,dc=net' user.
704 rewriteContext searchFilter
705 rewriteRule "(.*\e\e()uid=([a-z0-9_]+)(\e\e).*)"
706 "%{**binddn}<>%{&prefix(%1)}%{&arg(%2)}%{&suffix(%3)}"
708 rewriteRule "[^,]+,ou=admin,dc=home,dc=net"
709 "%{*prefix}|(uid=%{*arg})(cn=%{*arg})%{*suffix}" ":@I"
710 rewriteRule ".*<>" "%{*prefix}uid=%{*arg}%{*suffix}" ":"
712 # This example shows how to strip unwanted DN-valued
713 # attribute values from a search result; the first rule
714 # matches DN values below "ou=People,dc=example,dc=com";
715 # in case of match the rewriting exits successfully.
716 # The second rule matches everything else and causes
717 # the value to be rejected.
718 rewriteContext searchResult
719 rewriteRule ".*,ou=People,dc=example,dc=com" "%0" ":@"
720 rewriteRule ".*" "" "#"
722 .SH "LDAP Proxy resolution (a possible evolution of slapd\-ldap(5)):"
723 In case the rewritten DN is an LDAP URI, the operation is initiated
724 towards the host[:port] indicated in the uri, if it does not refer
729 rewriteRule '^cn=root,.*' '%0' 'G{3}'
730 rewriteRule '^cn=[a-l].*' 'ldap://ldap1.my.org/%0' ':@'
731 rewriteRule '^cn=[m-z].*' 'ldap://ldap2.my.org/%0' ':@'
732 rewriteRule '.*' 'ldap://ldap3.my.org/%0' ':@'
735 (Rule 1 is simply there to illustrate the `G{n}' action; it could have
739 rewriteRule '^cn=root,.*' 'ldap://ldap3.my.org/%0' ':@'
742 with the advantage of saving one rewrite pass ...)
747 backend does not honor all ACL semantics as described in
748 .BR slapd.access (5).
749 In general, access checking is delegated to the remote server(s).
754 pseudo-attribute and to the other attribute values of the entries
757 operation is honored, which is performed by the frontend.
759 .SH PROXY CACHE OVERLAY
760 The proxy cache overlay
761 allows caching of LDAP search requests (queries) in a local database.
768 default slapd configuration file
772 .BR slapo\-pcache (5),
777 Pierangelo Masarati, based on back-ldap by Howard Chu