On 06/06/13 09:51, Howard Chu wrote:
> Clément OUDOT wrote:
>> 2013/6/6 Howard Chu <
hyc@symas.com>:
>>> Far a wrote:
>>>> * Is there a list of dos and don'ts
and list of possible issues for
>>>>
>>>> migrating from SUN
>>>> one LDAP TO openldap on Linux
>
>>> I haven't seen any such list.
>>
>> Hi,
>>
>> you can find some notes here:
>>
http://www.linid.org/projects/openldap-manager/wiki/MigrationSunOracle
>
> This appears to be a list of differences between the
SunOne DS and
> OpenLDAP slapd, not differences in the Sun LDAP C SDK
and the OpenLDAP
> C SDK. Quite a different topic from the question in
this thread.
>
I don't have a thorough list or document with specific
guidance but I
can pass on a few pointers.
Assuming the goal is to move off Solaris (iPlanet/Mozilla
vintage)
libldap.so.5 to a recent OpenLDAP
libldap-2.4.so.2 library, then here are a few things to
think about.
1) for the most part if you are using any of the common
APIs such as
ldap_search_ext_s etc. these
will work fine with just a recompile. In my experience
80-90+% of your
LDAP code will remain unmodified.
Also you can probably catch everything you need to change
by just
updating your build environment
to the OpenLDAP headers and libraries, and fix the compile
errors that
show up.
2) Presumably your application uses the old ldap_init
style interfaces
(the only ones that existed in libldap.so.5)
so you need to make a decision to either convert them to
newer
ldap_initialize APIs or enable LDAP_DEPRECATE.
If you are using non-secure connections then you can stay
with the old
APIs, but if you are using secure
connections and have tapped into the NSPR portions of
libldap.so.5 (aka
any prldap* API) you need to
rip that stuff out and start using ldap_initialize. My
$0.02
regardless, just change over to ldap_initialize even
if you are not using SSL.
3) review your ldap_get_option and ldap_set_option calls.
There are a
few differences
such as LDAP_OPT_NETWORK_TIMEOUT instead of
LDAP_X_OPT_CONNECT_TIMEOUT
and those differences need to be changed. A test compile
will expose
them all.
4) If you are using libldap.so.5 ldap_get_lderrno you will
need to
change that code to call
ldap_get_option and call
(void) ldap_get_option(ld, LDAP_OPT_RESULT_CODE,
&err);
(void) ldap_get_option(ld,
LDAP_OPT_DIAGNOSTIC_MESSAGE, &s);
(void) ldap_get_option(ld, LDAP_OPT_MATCHED_DN,
&m);
as needed. Similarly a test compile will flag these
places.
5) The function calls to manage controls (such as
virtuallist) are
different between the libraries, and
if used, the application will need some adjustment there.
If you are using some other libldap.so.5 specific
functions you might
have to do a little more
work, but in general everything above probably accounts
for 99+% of an
application conversion.
The only other big difference is if your application
specifically has
multiple threads sharing/multiplexing
requests over the same connection. If it does you need to
look at and
use the OpenLDAP
ldap_dup/ldap_destroy APIs. Here you may need to rip out
some more
prldap* functions and
rework the code, but that will be dependent on your
application specifics.
In my experience, if you look out for these issues, then
moving to the
OpenLDAP libldap library
is pretty straight forward.
Doug.