LDAP: Filter out multiple entries when searching overlapping domains

In case domain overlap, we might download multiple objects. To avoid
saving them all, we attempt to filter out the objects from foreign
domains.

We can only do this optimization for non-wildcard lookups.

Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/src/providers/ldap/sdap.c b/src/providers/ldap/sdap.c
index 5aa7ff7ca..fcdc4028e 100644
--- a/src/providers/ldap/sdap.c
+++ b/src/providers/ldap/sdap.c
@@ -1619,3 +1619,62 @@ char *sdap_make_oc_list(TALLOC_CTX *mem_ctx, struct sdap_attr_map *map)
                                map[SDAP_OC_GROUP_ALT].name);
     }
 }
+
+static bool sdap_object_in_domain(struct sdap_options *opts,
+                                  struct sysdb_attrs *obj,
+                                  struct sss_domain_info *dom)
+{
+    errno_t ret;
+    const char *original_dn = NULL;
+    struct sdap_domain *sdmatch = NULL;
+
+    ret = sysdb_attrs_get_string(obj, SYSDB_ORIG_DN, &original_dn);
+    if (ret) {
+        DEBUG(SSSDBG_FUNC_DATA,
+              "The group has no original DN, assuming our domain\n");
+        return true;
+    }
+
+    sdmatch = sdap_domain_get_by_dn(opts, original_dn);
+    if (sdmatch == NULL) {
+        DEBUG(SSSDBG_FUNC_DATA,
+              "The group has no original DN, assuming our domain\n");
+        return true;
+    }
+
+    return (sdmatch->dom == dom);
+}
+
+size_t sdap_steal_objects_in_dom(struct sdap_options *opts,
+                                 struct sysdb_attrs **dom_objects,
+                                 size_t offset,
+                                 struct sss_domain_info *dom,
+                                 struct sysdb_attrs **all_objects,
+                                 size_t count,
+                                 bool filter)
+{
+    size_t copied = 0;
+
+    /* Own objects from all_objects by dom_objects in case they belong
+     * to domain dom.
+     *
+     * Don't copy objects from other domains in case
+     * the search was for parent domain but a child domain would match,
+     * too, such as:
+     *  dc=example,dc=com
+     *  dc=child,dc=example,dc=com
+     * while searching for an object from dc=example.
+     */
+    for (size_t i = 0; i < count; i++) {
+        if (filter &&
+                sdap_object_in_domain(opts, all_objects[i], dom) == false) {
+            continue;
+        }
+
+        dom_objects[offset + copied] =
+            talloc_steal(dom_objects, all_objects[i]);
+        copied++;
+    }
+
+    return copied;
+}