idmap_autorid: extend idmap_autorid_addrange to allow to set mappings below the HWM

Signed-off-by: Michael Adam <obnox@samba.org>

diff --git a/source3/winbindd/idmap_autorid_tdb.c b/source3/winbindd/idmap_autorid_tdb.c
index f6d3f715df5bb753029fb35c3da63487e7610ec5..95cc12c4e25af7c6d612695bd33787b27efe687a 100644 (file)
--- a/source3/winbindd/idmap_autorid_tdb.c
+++ b/source3/winbindd/idmap_autorid_tdb.c
@@ -147,18 +147,6 @@ static NTSTATUS idmap_autorid_addrange_action(struct db_context *db,
                 * automatically acquire the next range
                 */
                requested_rangenum = hwm;
-       } else {
-               /*
-                * set a specified range
-                */
-
-               if (requested_rangenum < hwm) {
-                       DEBUG(3, ("Invalid range %u requested: Range may not "
-                                 "be smaller than %u (current HWM)\n",
-                                 requested_rangenum, hwm));
-                       ret = NT_STATUS_INVALID_PARAMETER;
-                       goto error;
-               }
        }
 
        if (requested_rangenum >= globalcfg->maxranges) {
@@ -170,18 +158,47 @@ static NTSTATUS idmap_autorid_addrange_action(struct db_context *db,
                goto error;
        }
 
-       /* HWM always contains current max range + 1 */
-       increment = requested_rangenum + 1 - hwm;
+       if (requested_rangenum < hwm) {
+               /*
+                * Set a specified range below the HWM:
+                * We need to check that it is not yet taken.
+                */
 
-       /* increase the HWM */
-       ret = dbwrap_change_uint32_atomic_bystring(db, HWM, &hwm, increment);
-       if (!NT_STATUS_IS_OK(ret)) {
-               DEBUG(1, ("Fatal error while incrementing the HWM value "
-                         "in the database: %s\n", nt_errstr(ret)));
-               goto error;
+               numstr = talloc_asprintf(mem_ctx, "%u", requested_rangenum);
+               if (!numstr) {
+                       ret = NT_STATUS_NO_MEMORY;
+                       goto error;
+               }
+
+               if (dbwrap_exists(db, string_term_tdb_data(numstr))) {
+                       DEBUG(1, ("Requested range already in use.\n"));
+                       ret = NT_STATUS_INVALID_PARAMETER;
+                       goto error;
+               }
+
+               TALLOC_FREE(numstr);
+       } else {
+               /*
+                * requested or automatic range >= HWM:
+                * increment the HWM.
+                */
+
+               /* HWM always contains current max range + 1 */
+               increment = requested_rangenum + 1 - hwm;
+
+               /* increase the HWM */
+               ret = dbwrap_change_uint32_atomic_bystring(db, HWM, &hwm, increment);
+               if (!NT_STATUS_IS_OK(ret)) {
+                       DEBUG(1, ("Fatal error while incrementing the HWM value "
+                                 "in the database: %s\n", nt_errstr(ret)));
+                       goto error;
+               }
        }
 
-       /* store away the new mapping in both directions */
+       /*
+        * store away the new mapping in both directions
+        */
+
        ret = dbwrap_store_uint32_bystring(db, keystr, requested_rangenum);
        if (!NT_STATUS_IS_OK(ret)) {
                DEBUG(1, ("Fatal error while storing new "