idmap_cache: Introduce idmap_cache_find_xid2sid

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Christof Schmitt <cs@samba.org>
Bug: https://bugzilla.samba.org/show_bug.cgi?id=13813
(cherry picked from commit bb8122dd8c53bb307819a79b7888cc0940a7c13b)

2 files changed, 38 insertions, 0 deletions

diff --git a/source3/lib/idmap_cache.c b/source3/lib/idmap_cache.c
index cf63a229da5..9fc32215001 100644
--- a/source3/lib/idmap_cache.c
+++ b/source3/lib/idmap_cache.c
@@ -276,6 +276,42 @@ bool idmap_cache_find_gid2sid(gid_t gid, struct dom_sid *sid, bool *expired)
 }
 
 /**
+ * Find a xid2sid mapping
+ * @param[in] id		the unix id to map
+ * @param[out] sid		where to put the result
+ * @param[out] expired		is the cache entry expired?
+ * @retval Was anything in the cache at all?
+ *
+ * If "is_null_sid(sid)", this was a negative mapping.
+ */
+bool idmap_cache_find_xid2sid(
+	const struct unixid *id, struct dom_sid *sid, bool *expired)
+{
+	struct idmap_cache_xid2sid_state state = {
+		.sid = sid, .expired = expired
+	};
+	fstring key;
+	char c;
+
+	switch (id->type) {
+	case ID_TYPE_UID:
+		c = 'U';
+		break;
+	case ID_TYPE_GID:
+		c = 'G';
+		break;
+	default:
+		return false;
+	}
+
+	fstr_sprintf(key, "IDMAP/%cID2SID/%d", c, (int)id->id);
+
+	gencache_parse(key, idmap_cache_xid2sid_parser, &state);
+	return state.ret;
+}
+
+
+/**
  * Store a mapping in the idmap cache
  * @param[in] sid		the sid to map
  * @param[in] unix_id		the unix_id to map
diff --git a/source3/lib/idmap_cache.h b/source3/lib/idmap_cache.h
index dc497022e3b..d5afa170e1a 100644
--- a/source3/lib/idmap_cache.h
+++ b/source3/lib/idmap_cache.h
@@ -31,6 +31,8 @@ bool idmap_cache_find_sid2gid(const struct dom_sid *sid, gid_t *pgid,
 			      bool *expired);
 bool idmap_cache_find_uid2sid(uid_t uid, struct dom_sid *sid, bool *expired);
 bool idmap_cache_find_gid2sid(gid_t gid, struct dom_sid *sid, bool *expired);
+bool idmap_cache_find_xid2sid(
+	const struct unixid *id, struct dom_sid *sid, bool *expired);
 void idmap_cache_set_sid2unixid(const struct dom_sid *sid, struct unixid *unix_id);
 
 bool idmap_cache_del_uid(uid_t uid);