slapd−shell — Shell backend to slapd
ETCDIR/slapd.conf
The Shell backend to slapd(8) executes external
programs to implement operations, and is designed to make it
easy to tie an existing database to the slapd front-end.
This backend is primarily intended to be used in prototypes.
These slapd.conf
options apply to the SHELL backend database. That is, they
must follow a "database shell" line and come before any
subsequent "backend" or "database" lines. Other database
options are described in the slapd.conf(5) manual
page.
These options specify the pathname and arguments of the program to execute in response to the given LDAP operation. Each option is followed by the input lines that the program receives:
ADD
msgid: <message id>
<repeat { "suffix:" <database suffix DN> }>
<entry in LDIF format>
BIND
msgid: <message id>
<repeat { "suffix:" <database suffix DN> }>
dn: <DN>
method: <method number>
credlen: <length of <credentials>>
cred: <credentials>
COMPARE
msgid: <message id>
<repeat { "suffix:" <database suffix DN> }>
dn: <DN>
<attribute>: <value>
DELETE
msgid: <message id>
<repeat { "suffix:" <database suffix DN> }>
dn: <DN>
MODIFY
msgid: <message id>
<repeat { "suffix:" <database suffix DN> }>
dn: <DN>
<repeat {
<"add"/"delete"/"replace">: <attribute>
<repeat { <attribute>: <value> }>
−
}>
MODRDN
msgid: <message id>
<repeat { "suffix:" <database suffix DN> }>
dn: <DN>
newrdn: <new RDN>
deleteoldrdn: <0 or 1>
<if new superior is specified: "newSuperior: <DN>">
SEARCH
msgid: <message id>
<repeat { "suffix:" <database suffix DN> }>
base: <base DN>
scope: <0-2, see ldap.h>
deref: <0-3, see ldap.h>
sizelimit: <size limit>
timelimit: <time limit>
filter: <filter>
attrsonly: <0 or 1>
attrs: <"all" or space-separated attribute list>
UNBIND
msgid: <message id>
<repeat { "suffix:" <database suffix DN> }>
dn: <bound DN>
Note that you need only supply configuration lines for those commands you want the backend to handle. Operations for which a command is not supplied will be refused with an "unwilling to perform" error.
The search
command should output the entries in LDIF format, each entry
followed by a blank line, and after these the RESULT
below.
All commands except unbind should then
output:
RESULT code: <integer> matched: <matched DN> info: <text>
where only the RESULT line is mandatory. Lines starting with `#' or `DEBUG:' are ignored.
The shell
backend does not honor all ACL semantics as described in
slapd.access(5). In
general, access to objects is checked by using a dummy object
that contains only the DN, so access rules that rely on the
contents of the object are not honored. In detail:
The add
operation does not require write
(=w) access to the children pseudo-attribute of
the parent entry.
The bind
operation requires auth
(=x) access to the entry pseudo-attribute of the
entry whose identity is being assessed; auth (=x) access to the
credentials is not checked, but rather delegated to the
underlying shell script.
The compare
operation requires read
(=r) access (FIXME: wouldn't compare (=c) be a more appropriate
choice?) to the entry pseudo-attribute of the
object whose value is being asserted; compare (=c) access to the
attribute whose value is being asserted is not checked.
The delete
operation does not require write
(=w) access to the children pseudo-attribute of
the parent entry.
The modify
operation requires write
(=w) access to the entry pseudo-attribute;
write (=w) access to
the specific attributes that are modified is not checked.
The modrdn
operation does not require write
(=w) access to the children pseudo-attribute of
the parent entry, nor to that of the new parent, if
different; write (=w)
access to the distinguished values of the naming attributes
is not checked.
The search
operation does not require search
(=s) access to the entry pseudo_attribute of the
searchBase; search
(=s) access to the attributes and values used in
the filter is not checked.
There is an example search script in the slapd/back−shell/ directory in the OpenLDAP source tree.
The shell backend does not support threaded environments.
When using the shell backend, slapd(8) should be built
−−without−threads.