SDAP: Set initgroups expire attribute at the end

Initgrups consisted of two main steps:
1. store user to cache
2. store all user groups to cache.

Previously the attribute SYSDB_INITGR_EXPIRE was set in the first step.
So in case of epmty cache and parallel initgroups request in responders
there was a small period when SYSDB_INITGR_EXPIRE was valid but groups were
not cached. Therefore sometime responder could return zero supplementary
groups.

This patch moves the setting of initgroups expire attribute from 1st step
to the end of 2nd step.

In case of parallel initgroups requests in responder there are two
other ways how we could get correct results even thought there was a bug.
 a) Time between two request was too small. User was not stored in cache
    yet and 2nd request waited for response from DP.
 b) Time between two request was big enough. All users groups were
    successfully stored in cache and 2nd request returned correct results.

Resolves:
https://fedorahosted.org/sssd/ticket/2634

Reviewed-by: Pavel Březina <pbrezina@redhat.com>
(cherry picked from commit d0cc678d20d8bde829450eb50bec1b7397cea3e1)
(cherry picked from commit 9ae6567a573c05ba59d1138cfda94b44732019e8)

2 files changed, 42 insertions, 9 deletions

diff --git a/src/providers/ldap/ldap_id.c b/src/providers/ldap/ldap_id.c
index 63098a82e..1a44de852 100644
--- a/src/providers/ldap/ldap_id.c
+++ b/src/providers/ldap/ldap_id.c
@@ -977,6 +977,40 @@ static int groups_by_user_retry(struct tevent_req *req);
 static void groups_by_user_connect_done(struct tevent_req *subreq);
 static void groups_by_user_done(struct tevent_req *subreq);
 
+static errno_t set_initgroups_expire_attribute(struct sss_domain_info *domain,
+                                               const char *name)
+{
+    errno_t ret;
+    time_t cache_timeout;
+    struct sysdb_attrs *attrs;
+
+    attrs = sysdb_new_attrs(NULL);
+    if (attrs == NULL) {
+        return ENOMEM;
+    }
+
+    cache_timeout = domain->user_timeout
+                        ? time(NULL) + domain->user_timeout
+                        : 0;
+
+    ret = sysdb_attrs_add_time_t(attrs, SYSDB_INITGR_EXPIRE, cache_timeout);
+    if (ret != EOK) {
+        DEBUG(SSSDBG_CRIT_FAILURE, "Could not set up attrs\n");
+        goto done;
+    }
+
+    ret = sysdb_set_user_attr(domain, name, attrs, SYSDB_MOD_REP);
+    if (ret != EOK) {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              "Failed to set initgroups expire attribute\n");
+        goto done;
+    }
+
+done:
+    talloc_zfree(attrs);
+    return ret;
+}
+
 static struct tevent_req *groups_by_user_send(TALLOC_CTX *memctx,
                                               struct tevent_context *ev,
                                               struct sdap_id_ctx *ctx,
@@ -1121,6 +1155,14 @@ static void groups_by_user_done(struct tevent_req *subreq)
         }
     }
 
+    ret = set_initgroups_expire_attribute(state->ctx->be->domain,
+                                          state->name);
+    if (ret != EOK) {
+        state->dp_error = DP_ERR_FATAL;
+        tevent_req_error(req, ret);
+        return;
+    }
+
     state->dp_error = DP_ERR_OK;
     tevent_req_done(req);
 }
diff --git a/src/providers/ldap/sdap_async_users.c b/src/providers/ldap/sdap_async_users.c
index 82b4df479..89e5ae558 100644
--- a/src/providers/ldap/sdap_async_users.c
+++ b/src/providers/ldap/sdap_async_users.c
@@ -467,15 +467,6 @@ int sdap_save_user(TALLOC_CTX *memctx,
 
     cache_timeout = dom->user_timeout;
 
-    if (is_initgr) {
-        ret = sysdb_attrs_add_time_t(user_attrs, SYSDB_INITGR_EXPIRE,
-                                     (cache_timeout ?
-                                      (time(NULL) + cache_timeout) : 0));
-        if (ret) {
-            goto done;
-        }
-    }
-
     ret = sdap_save_all_names(user_name, attrs, dom, user_attrs);
     if (ret != EOK) {
         DEBUG(SSSDBG_CRIT_FAILURE, "Failed to save user names\n");