Old implementation handles username and group names with
one common call. Character @ is used in the call to detect UPN.
Group name can legaly contain this character and therefore the
common approach doesn't work in such case.
Also the original call is less efficient because it tries to resolv
username allways then it fallback to group resolution.
Here we implement two new separate calls for resolving users and
groups.
Fixes: https://bugzilla.redhat.com/1746951
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
The user and group lookups done by the extdom plugin might need some
time depending on the state of the service (typically SSSD) handling the
requests.
To avoid that all worker threads are busy waiting on a connect or a
reply from SSSD and no other request can be handled this patch adds an
instance counter and an instance limit for the extdom plugin.
By default the limit will be around 80% of the number of worker threads.
It can be tuned further with the plugin option ipaExtdomMaxInstances
which must in set in ipaextdommaxinstances and should have an integer
value larger than 0 and lesser than the number of worker threads.
If the instance limit is reached the extdom plugin will return LDAP_BUSY
for every new request until the number of instance is again below the
limit.
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Refactor nsswitch operations in ipa-extdom-extop plugin to allow use
of timeout-enabled nsswitch calls provided by libsss_nss_idmap.
Standard POSIX nsswitch API has no way to cancel requests which may
cause ipa-extdom-extop requests to hang far too long and potentially
exhaust LDAP server workers. In addition, glibc nsswitch API iterates
through all nsswitch modules one by one and with multiple parallel
requests a lock up may happen in an unrelated nsswitch module like
nss_files.so.2.
A solution to the latter issue is to directly load nss_sss.so.2 plugin
and utilize it. This, however, does not solve a problem with lack of
cancellable API.
With SSSD 1.16.1, libsss_nss_idmap provides a timeout-enabled variant of
nsswitch API that is directly integrated with SSSD client side machinery
used by nss_sss.so.2. As result, this API can be used instead of loading
nss_sss.so.2 directly.
To support older SSSD version, both direct loading of nss_sss.so.2 and
new timeout-enabled API are supported by this changeset. An API to
abstract both is designed to be a mix between internal glibc nsswitch
API and external nsswitch API that libsss_nss_idmap mimics. API does not
expose per-call timeout. Instead, it allows to set a timeout per
nsswitch operation context to reduce requirements on information
a caller has to maintain.
A choice which API to use is made at configure time.
In order to test the API, a cmocka test is updated to explicitly load
nss_files.so.2 as a backend. Since use of nss_sss.so.2 would always
depend on availablility of SSSD, predictable testing would not be
possible without it otherwise. Also, cmocka test does not use
nss_wrapper anymore because nss_wrapper overrides higher level glibc
nsswitch API while we are loading an individual nsswitch module
directly.
As result, cmocka test overrides fopen() call used by nss_files.so.2 to
load /etc/passwd and /etc/group. An overridden version changes paths to
/etc/passwd and /etc/group to a local test_data/passwd and
test_data/group. This way we can continue testing a backend API for
ipa-extdom-extop with the same data as with nss_wrapper.
Fixes https://pagure.io/freeipa/issue/5464
Reviewed-By: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Simo Sorce <ssorce@redhat.com>
Reviewed-By: Robbie Harwood <rharwood@redhat.com>
Certificates can be assigned to multiple user so the extdom plugin must
use sss_nss_getlistbycert() instead of sss_nss_getnamebycert() and
return a list of fully-qualified user names.
Due to issues on the SSSD side the current version of lookups by
certificates didn't work at all and the changes here won't break
existing clients.
Related to https://pagure.io/freeipa/issue/6826
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: David Kupka <dkupka@redhat.com>
Using a pragma instead of guards is easier to write, less error prone
and avoids name clashes (a source of very subtle bugs). This pragma
is supported on almost all compilers, including all the compilers we
care about: https://en.wikipedia.org/wiki/Pragma_once#Portability.
This patch does not change the autogenerated files: asn1/asn1c/*.h.
Reviewed-By: Martin Basti <mbasti@redhat.com>
Reviewed-By: Christian Heimes <cheimes@redhat.com>
The get*_r_wrapper() calls expect a maximum buffer size to avoid memory
shortage if too many threads try to allocate buffers e.g. for large
groups. With this patch this size can be configured by setting
ipaExtdomMaxNssBufSize in the plugin config object
cn=ipa_extdom_extop,cn=plugins,cn=config.
Related to https://fedorahosted.org/freeipa/ticket/4908
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
The getXXYYY_r() calls require a buffer to store the variable data of
the passwd and group structs. If the provided buffer is too small ERANGE
is returned and the caller can try with a larger buffer again.
Cmocka/cwrap based unit-tests for get*_r_wrapper() are added.
Resolves https://fedorahosted.org/freeipa/ticket/4908
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Currently the extdom plugin is basically used to translate SIDs of AD
users and groups to names and POSIX IDs.
With this patch a new version is added which will return the full member
list for groups and the full list of group memberships for a user.
Additionally the gecos field, the home directory and the login shell of a
user are returned and an optional list of key-value pairs which
currently will contain the SID of the requested object if available.
https://fedorahosted.org/freeipa/ticket/4031
Reviewed-By: Jakub Hrozek <jhrozek@redhat.com>
With the new ipa_server_mode SSSD is able to read user and group data
from trusted AD domains directly and makes this data available via the
NSS responder. With this mode enabled winbind is not needed anymore to
lookup users and groups of trusted domains.
This patch removed the calls to winbind from the extdom plugin and
replaces them with standard POSIX calls like getpwnam() and calls from
libsss_nss_idmap to lookup SIDs.
Fixes https://fedorahosted.org/freeipa/ticket/3637 because now the
extdom plugin does not need to handle idranges anymore, but everything
is done inside SSSD.
This extop can be used by clients of the IPA domain, e.g. sssd, to
retrieve data from trusted external domains. It can be used e.g. to map
Windows SIDs to user or groups names and back.
Tomas Halman
Sumit Bose
Alexander Bokovoy
Nathaniel McCallum