бэкэнд метакаталога для slapd (metadirectory backend to slapd)
Целевая спецификация (Target specification)
Target specification starts with a "uri" directive:
uri <protocol>://[<host>]/<naming context> [...]
The <protocol> part can be anything ldap_initialize(3)
accepts ({ldap|ldaps|ldapi} and variants); the <host> may
be omitted, defaulting to whatever is set in ldap.conf(5).
The <naming context> part is mandatory for the first URI,
but it must be omitted for subsequent ones, if any. The
naming context part must be within the naming context
defined for the backend, e.g.:
suffix "dc=foo,dc=com"
uri "ldap://x.foo.com/dc=x,dc=foo,dc=com"
The <naming context> part doesn't need to be unique across
the targets; it may also match one of the values of the
"suffix" directive. Multiple URIs may be defined in a
single URI statement. The additional URIs must be
separate arguments and must not have any <naming context>
part. This causes the underlying library to contact the
first server of the list that responds. For example, if
l1.foo.com and l2.foo.com are shadows of the same server,
the directive
suffix "dc=foo,dc=com"
uri "ldap://l1.foo.com/dc=foo,dc=com" "ldap://l2.foo.com/"
causes l2.foo.com to be contacted whenever l1.foo.com does
not respond. In that case, the URI list is internally
rearranged, by moving unavailable URIs to the end, so that
further connection attempts occur with respect to the last
URI that succeeded.
acl-authcDN <administrative DN for access control purposes>
DN which is used to query the target server for acl
checking, as in the LDAP backend; it is supposed to have
read access on the target server to attributes used on the
proxy for acl checking. There is no risk of giving away
such values; they are only used to check permissions. The
acl-authcDN identity is by no means implicitly used by the
proxy when the client connects anonymously.
acl-passwd <password>
Password used with the acl-authcDN above.
bind-timeout <microseconds>
This directive defines the timeout, in microseconds, used
when polling for response after an asynchronous bind
connection. The initial call to ldap_result(3) is
performed with a trade-off timeout of 100000 us; if that
results in a timeout exceeded, subsequent calls use the
value provided with bind-timeout. The default value is
used also for subsequent calls if bind-timeout is not
specified. If set before any target specification, it
affects all targets, unless overridden by any per-target
directive.
chase-referrals {YES|no}
enable/disable automatic referral chasing, which is
delegated to the underlying libldap, with rebinding
eventually performed if the rebind-as-user directive is
used. The default is to chase referrals. If set before
any target specification, it affects all targets, unless
overridden by any per-target directive.
client-pr {accept-unsolicited|DISABLE|<size>}
This feature allows one to use RFC 2696 Paged Results
control when performing search operations with a specific
target, irrespective of the client's request. When set to
a numeric value, Paged Results control is always used with
size as the page size. When set to accept-unsolicited,
unsolicited Paged Results control responses are accepted
and honored for compatibility with broken remote DSAs.
The client is not exposed to paged results handling
between slapd-meta(5) and the remote servers. By default
(disabled), Paged Results control is not used and
responses are not accepted. If set before any target
specification, it affects all targets, unless overridden
by any per-target directive.
default-target [<target>]
The "default-target" directive can also be used during
target specification. With no arguments it marks the
current target as the default. The optional number marks
target <target> as the default one, starting from 1.
Target <target> must be defined.
filter <pattern>
This directive allows specifying a regex(5) pattern to
indicate what search filter terms are actually served by a
target.
In a search request, if the search filter matches the
pattern the target is considered while fulfilling the
request; otherwise the target is ignored. There may be
multiple occurrences of the filter directive for each
target.
idassert-authzFrom <authz-regexp>
if defined, selects what local identities are authorized
to exploit the identity assertion feature. The string
<authz-regexp> follows the rules defined for the authzFrom
attribute. See slapd.conf(5), section related to
authz-policy, for details on the syntax of this field.
idassert-bind bindmethod=none|simple|sasl [binddn=<simple DN>]
[credentials=<simple password>] [saslmech=<SASL mech>]
[secprops=<properties>] [realm=<realm>]
[authcId=<authentication ID>] [authzId=<authorization ID>]
[authz={native|proxyauthz}] [mode=<mode>] [flags=<flags>]
[starttls=no|yes|critical] [tls_cert=<file>]
[tls_key=<file>] [tls_cacert=<file>]
[tls_cacertdir=<path>]
[tls_reqcert=never|allow|try|demand]
[tls_reqsan=never|allow|try|demand]
[tls_cipher_suite=<ciphers>] [tls_ecname=<ciphers>]
[tls_protocol_min=<major>[.<minor>]]
[tls_crlcheck=none|peer|all]
Allows one to define the parameters of the authentication
method that is internally used by the proxy to authorize
connections that are authenticated by other databases.
The identity defined by this directive, according to the
properties associated to the authentication method, is
supposed to have auth access on the target server to
attributes used on the proxy for authentication and
authorization, and to be allowed to authorize the users.
This requires to have proxyAuthz privileges on a wide set
of DNs, e.g. authzTo=dn.subtree:"", and the remote server
to have authz-policy set to to or both. See slapd.conf(5)
for details on these statements and for remarks and
drawbacks about their usage. The supported bindmethods
are
none|simple|sasl
where none is the default, i.e. no identity assertion is
performed.
The authz parameter is used to instruct the SASL bind to
exploit native SASL authorization, if available; since
connections are cached, this should only be used when
authorizing with a fixed identity (e.g. by means of the
authzDN or authzID parameters). Otherwise, the default
proxyauthz is used, i.e. the proxyAuthz control (Proxied
Authorization, RFC 4370) is added to all operations.
The supported modes are:
<mode> := {legacy|anonymous|none|self}
If <mode> is not present, and authzId is given, the proxy
always authorizes that identity. <authorization ID> can
be
u:<user>
[dn:]<DN>
The former is supposed to be expanded by the remote server
according to the authz rules; see slapd.conf(5) for
details. In the latter case, whether or not the dn:
prefix is present, the string must pass DN validation and
normalization.
The default mode is legacy, which implies that the proxy
will either perform a simple bind as the authcDN or a SASL
bind as the authcID and assert the client's identity when
it is not anonymous. Direct binds are always proxied.
The other modes imply that the proxy will always either
perform a simple bind as the authcDN or a SASL bind as the
authcID, unless restricted by idassert-authzFrom rules
(see below), in which case the operation will fail;
eventually, it will assert some other identity according
to <mode>. Other identity assertion modes are anonymous
and self, which respectively mean that the empty or the
client's identity will be asserted; none, which means that
no proxyAuthz control will be used, so the authcDN or the
authcID identity will be asserted. For all modes that
require the use of the proxyAuthz control, on the remote
server the proxy identity must have appropriate authzTo
permissions, or the asserted identities must have
appropriate authzFrom permissions. Note, however, that
the ID assertion feature is mostly useful when the
asserted identities do not exist on the remote server.
When bindmethod is SASL, the authcDN must be specified in
addition to the authcID, although it is not used within
the authentication process.
Flags can be
override,[non-]prescriptive,proxy-authz-[non-]critical
When the override flag is used, identity assertion takes
place even when the database is authorizing for the
identity of the client, i.e. after binding with the
provided identity, and thus authenticating it, the proxy
performs the identity assertion using the configured
identity and authentication method.
When the prescriptive flag is used (the default),
operations fail with inappropriateAuthentication for those
identities whose assertion is not allowed by the
idassert-authzFrom patterns. If the non-prescriptive flag
is used, operations are performed anonymously for those
identities whose assertion is not allowed by the
idassert-authzFrom patterns.
When the proxy-authz-non-critical flag is used (the
default), the proxyAuthz control is not marked as
critical, in violation of RFC 4370. Use of
proxy-authz-critical is recommended.
The TLS settings default to the same as the main slapd TLS
settings, except for tls_reqcert which defaults to
"demand", and tls_reqsan which defaults to "allow"..
The identity associated to this directive is also used for
privileged operations whenever idassert-bind is defined
and acl-bind is not. See acl-bind for details.
idle-timeout <time>
This directive causes a cached connection to be dropped an
recreated after it has been idle for the specified time.
The value can be specified as
[<d>d][<h>h][<m>m][<s>[s]]
where <d>, <h>, <m> and <s> are respectively treated as
days, hours, minutes and seconds. If set before any
target specification, it affects all targets, unless
overridden by any per-target directive.
keepalive <idle>:<probes>:<interval>
The keepalive parameter sets the values of idle, probes,
and interval used to check whether a socket is alive; idle
is the number of seconds a connection needs to remain idle
before TCP starts sending keepalive probes; probes is the
maximum number of keepalive probes TCP should send before
dropping the connection; interval is interval in seconds
between individual keepalive probes. Only some systems
support the customization of these values; the keepalive
parameter is ignored otherwise, and system-wide settings
are used.
tcp-user-timeout <milliseconds>
If non-zero, corresponds to the TCP_USER_TIMEOUT set on
the target connections, overriding the operating system
setting. Only some systems support the customization of
this parameter, it is ignored otherwise and system-wide
settings are used.
map {attribute|objectclass} [<local name>|*] {<foreign name>|*}
This maps object classes and attributes as in the LDAP
backend. See slapd-ldap(5).
network-timeout <time>
Sets the network timeout value after which
poll(2)/select(2) following a connect(2) returns in case
of no activity. The value is in seconds, and it can be
specified as for idle-timeout. If set before any target
specification, it affects all targets, unless overridden
by any per-target directive.
nretries {forever|never|<nretries>}
This directive defines how many times a bind should be
retried in case of temporary failure in contacting a
target. If defined before any target specification, it
applies to all targets (by default, 3 times); the global
value can be overridden by redefinitions inside each
target specification.
rewrite* ...
The rewrite options are described in the "REWRITING"
section.
subtree-{exclude|include} <rule>
This directive allows one to indicate what subtrees are
actually served by a target. The syntax of the supported
rules is
<rule>: [dn[.<style>]:]<pattern>
<style>: subtree|children|regex
When <style> is either subtree or children the <pattern>
is a DN that must be within the naming context served by
the target. When <style> is regex the <pattern> is a
regex(5) pattern. If the dn.<style>: prefix is omitted,
dn.subtree: is implicitly assumed for backward
compatibility.
In the subtree-exclude form if the request DN matches at
least one rule, the target is not considered while
fulfilling the request; otherwise, the target is
considered based on the value of the request DN. When the
request is a search, also the scope is considered.
In the subtree-include form if the request DN matches at
least one rule, the target is considered while fulfilling
the request; otherwise the target is ignored.
| match | exclude |
+---------+---------+-------------------+
| T | T | not candidate |
| F | T | continue checking |
+---------+---------+-------------------+
| T | F | candidate |
| F | F | not candidate |
+---------+---------+-------------------+
There may be multiple occurrences of the subtree-exclude
or subtree-include directive for each of the targets, but
they are mutually exclusive.
suffixmassage <virtual naming context> <real naming context>
All the directives starting with "rewrite" refer to the
rewrite engine that has been added to slapd. The
"suffixmassage" directive was introduced in the LDAP
backend to allow suffix massaging while proxying. It has
been obsoleted by the rewriting tools. However, both for
backward compatibility and for ease of configuration when
simple suffix massage is required, it has been preserved.
It wraps the basic rewriting instructions that perform
suffix massaging. See the "REWRITING" section for a
detailed list of the rewrite rules it implies.
t-f-support {NO|yes|discover}
enable if the remote server supports absolute filters (see
RFC 4526 for details). If set to discover, support is
detected by reading the remote server's root DSE. If set
before any target specification, it affects all targets,
unless overridden by any per-target directive.
timeout [<op>=]<val> [...]
This directive allows one to set per-operation timeouts.
Operations can be
<op> ::= bind, add, delete, modrdn, modify, compare,
search
The overall duration of the search operation is controlled
either by the timelimit parameter or by server-side
enforced time limits (see timelimit and limits in
slapd.conf(5) for details). This timeout parameter
controls how long the target can be irresponsive before
the operation is aborted. Timeout is meaningless for the
remaining operations, unbind and abandon, which do not
imply any response, while it is not yet implemented in
currently supported extended operations. If no operation
is specified, the timeout val affects all supported
operations. If specified before any target definition, it
affects all targets unless overridden by per-target
directives.
Note: if the timeout is exceeded, the operation is
cancelled (according to the cancel directive); the
protocol does not provide any means to rollback
operations, so the client will not be notified about the
result of the operation, which may eventually succeeded or
not. In case the timeout is exceeded during a bind
operation, the connection is destroyed, according to
RFC4511.
tls {none|[try-]start|[try-]propagate|ldaps}
[starttls=no] [tls_cert=<file>] [tls_key=<file>]
[tls_cacert=<file>] [tls_cacertdir=<path>]
[tls_reqcert=never|allow|try|demand]
[tls_reqsan=never|allow|try|demand]
[tls_cipher_suite=<ciphers>] [tls_ecname=<names>]
[tls_crlcheck=none|peer|all]
Specify TLS settings regular connections.
If the first parameter is not "none" then this configures
the TLS settings to be used for regular connections. The
StartTLS extended operation will be used when establishing
the connection unless the URI directive protocol scheme is
ldaps://. In that case this keyword may only be set to
"ldaps" and the StartTLS operation will not be used.
propagate issues the StartTLS operation only if the
original connection did. The try- prefix instructs the
proxy to continue operations if the StartTLS operation
failed; its use is highly deprecated. The TLS settings
default to the same as the main slapd TLS settings, except
for tls_reqcert which defaults to "demand", tls_reqsan
which defaults to "allow", and starttls which is
overshadowed by the first keyword and thus ignored.
If set before any target specification, it affects all
targets, unless overridden by any per-target directive.
