Re: (ITS#5768) [enhancement] add support for Dereference Control

[ando@sys-net.it]

A tentative implementation is in HEAD, please test.  You need to:

- configure as --enable-deref

- enable the "deref" overlay in slapd, with "overlay deref" (doesn't
work as global overlay yet, sorry).

- run searches like

$ ldapsearch -x -b dc=example,dc=com -E 'deref=member:entryUUID'

you'll see results like

# Alumni Assoc Staff, Groups, example.com
dn: cn=Alumni Assoc Staff,ou=Groups,dc=example,dc=com
control: 1.3.6.1.4.1.4203.666.5.16 false MIIDgjBdBAZtZW1iZXIEHGNuPU1hbmFnZXIsZ
  GM9ZXhhbXBsZSxkYz1jb22gNTAzBAllbnRyeVVVSUQxJgQkMjlkNTNiZjQtMzRhYi0xMDJkLThhNz
  MtYWI0MTM2OTEyOTExMIGFBAZtZW1iZXIERGNuPURvcm90aHkgU3RldmVucyxvdT1BbHVtbmkgQXN
  zb2NpYXRpb24sb3U9UGVvcGxlLGRjPWV4YW1wbGUsZGM9Y29toDUwMwQJZW50cnlVVUlEMSYEJDI5
  ZDNhNzQ0LTM0YWItMTAyZC04YTZjLWFiNDEzNjkxMjkxMTCBhQQGbWVtYmVyBERjbj1KYW1lcyBBI
  EpvbmVzIDEsb3U9QWx1bW5pIEFzc29jaWF0aW9uLG91PVBlb3BsZSxkYz1leGFtcGxlLGRjPWNvba
  A1MDMECWVudHJ5VVVJRDEmBCQyOWQ0MTM5Ni0zNGFiLTEwMmQtOGE2ZS1hYjQxMzY5MTI5MTEwfgQ
  GbWVtYmVyBD1jbj1KYW5lIERvZSxvdT1BbHVtbmkgQXNzb2NpYXRpb24sb3U9UGVvcGxlLGRjPWV4
  YW1wbGUsZGM9Y29toDUwMwQJZW50cnlVVUlEMSYEJDI5ZDQ4ZTQ4LTM0YWItMTAyZC04YTcwLWFiN
  DEzNjkxMjkxMTCBhAQGbWVtYmVyBENjbj1KZW5uaWZlciBTbWl0aCxvdT1BbHVtbmkgQXNzb2NpYX
  Rpb24sb3U9UGVvcGxlLGRjPWV4YW1wbGUsZGM9Y29toDUwMwQJZW50cnlVVUlEMSYEJDI5ZDRhNjR
  lLTM0YWItMTAyZC04YTcxLWFiNDEzNjkxMjkxMTCBgQQGbWVtYmVyBEBjbj1NYXJrIEVsbGlvdCxv
  dT1BbHVtbmkgQXNzb2NpYXRpb24sb3U9UGVvcGxlLGRjPWV4YW1wbGUsZGM9Y29toDUwMwQJZW50c
  nlVVUlEMSYEJDI5ZDU1NGY0LTM0YWItMTAyZC04YTc0LWFiNDEzNjkxMjkxMTCBhQQGbWVtYmVyBE
  Rjbj1VcnN1bGEgSGFtcHN0ZXIsb3U9QWx1bW5pIEFzc29jaWF0aW9uLG91PVBlb3BsZSxkYz1leGF
  tcGxlLGRjPWNvbaA1MDMECWVudHJ5VVVJRDEmBCQyOWQ1OGVkOC0zNGFiLTEwMmQtOGE3NS1hYjQx
  MzY5MTI5MTE=
# member: <entryUUID=29d53bf4-34ab-102d-8a73-ab4136912911>;cn=Manager,dc=exam
  ple,dc=com
# member: <entryUUID=29d3a744-34ab-102d-8a6c-ab4136912911>;cn=Dorothy Stevens
  ,ou=Alumni Association,ou=People,dc=example,dc=com
# member: <entryUUID=29d41396-34ab-102d-8a6e-ab4136912911>;cn=James A Jones 1
  ,ou=Alumni Association,ou=People,dc=example,dc=com
# member: <entryUUID=29d48e48-34ab-102d-8a70-ab4136912911>;cn=Jane Doe,ou=Alu
  mni Association,ou=People,dc=example,dc=com
# member: <entryUUID=29d4a64e-34ab-102d-8a71-ab4136912911>;cn=Jennifer Smith,
  ou=Alumni Association,ou=People,dc=example,dc=com
# member: <entryUUID=29d554f4-34ab-102d-8a74-ab4136912911>;cn=Mark Elliot,ou=
  Alumni Association,ou=People,dc=example,dc=com
# member: <entryUUID=29d58ed8-34ab-102d-8a75-ab4136912911>;cn=Ursula Hampster
  ,ou=Alumni Association,ou=People,dc=example,dc=com
member: cn=Manager,dc=example,dc=com
member: cn=Dorothy Stevens,ou=Alumni Association,ou=People,dc=example,dc=com
member: cn=James A Jones 1,ou=Alumni Association,ou=People,dc=example,dc=com
member: cn=Jane Doe,ou=Alumni Association,ou=People,dc=example,dc=com
member: cn=Jennifer Smith,ou=Alumni Association,ou=People,dc=example,dc=com
member: cn=Mark Elliot,ou=Alumni Association,ou=People,dc=example,dc=com
member: cn=Ursula Hampster,ou=Alumni Association,ou=People,dc=example,dc=com
owner: cn=Manager,dc=example,dc=com
description: All Alumni Assoc Staff
cn: Alumni Assoc Staff
objectClass: groupOfNames


The related C API is in libraries/libldap/deref.c; as a guideline, you can look
at clients/ttols/ldapsearch.c, which creates the control and parses the response
in order to print it in extended DN style.

The current specification is formalized in a comment in overlays/deref.c; I intend
to improve it and post it at <http://www.openldap.org/faq/data/cache/1469.html>.

Please report through the ITS.

p.





Ing. Pierangelo Masarati
OpenLDAP Core Team

SysNet s.r.l.
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