s4-dsdb: added dsdb_find_nc_root()

This is based on the function of the same name from Eduardo Lima
<eduardoll@gmail.com>, but using ldb_dn_compare, to give us
comparisons consistent with what the rest of the code uses.

We will use this function in combination with dsdb_wellknown_dn() to
find the Deleted Objects container for any object.

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

diff --git a/source4/dsdb/common/util.c b/source4/dsdb/common/util.c
index 1162196843957d2c9de56acb0f7e314e13bef3d0..ffc11b02f7bc4eb0f734879c73da05efdc51417a 100644 (file)
--- a/source4/dsdb/common/util.c
+++ b/source4/dsdb/common/util.c
@@ -2782,3 +2782,67 @@ int dsdb_wellknown_dn(struct ldb_context *samdb, TALLOC_CTX *mem_ctx,
        talloc_free(tmp_ctx);
        return LDB_SUCCESS;
 }
+
+
+/*
+  find a NC root given a DN within the NC
+ */
+int dsdb_find_nc_root(struct ldb_context *samdb, TALLOC_CTX *mem_ctx, struct ldb_dn *dn,
+                     struct ldb_dn **nc_root)
+{
+       const char *root_attrs[] = { "namingContexts", NULL };
+       TALLOC_CTX *tmp_ctx;
+       int ret;
+       struct ldb_message_element *el;
+       struct ldb_result *root_res;
+       int i;
+       struct ldb_dn **nc_dns;
+
+       tmp_ctx = talloc_new(samdb);
+       if (tmp_ctx == NULL) {
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       ret = ldb_search(samdb, tmp_ctx, &root_res,
+                        ldb_dn_new(tmp_ctx, samdb, ""), LDB_SCOPE_BASE, root_attrs, NULL);
+       if (ret) {
+               DEBUG(1,("Searching for namingContexts in rootDSE failed: %s\n", ldb_errstring(samdb)));
+               talloc_free(tmp_ctx);
+               return ret;
+       }
+
+       el = ldb_msg_find_element(root_res->msgs[0], "namingContexts");
+       if (!el) {
+               DEBUG(1,("Finding namingContexts element in root_res failed: %s\n",
+                       ldb_errstring(samdb)));
+              talloc_free(tmp_ctx);
+              return LDB_ERR_NO_SUCH_ATTRIBUTE;
+       }
+
+       nc_dns = talloc_array(tmp_ctx, struct ldb_dn *, el->num_values);
+       if (!nc_dns) {
+              talloc_free(tmp_ctx);
+              return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       for (i=0; i<el->num_values; i++) {
+              nc_dns[i] = ldb_dn_from_ldb_val(nc_dns, samdb, &el->values[i]);
+              if (nc_dns[i] == NULL) {
+                      talloc_free(tmp_ctx);
+                      return LDB_ERR_OPERATIONS_ERROR;
+              }
+       }
+
+       qsort(nc_dns, el->num_values, sizeof(nc_dns[0]), (comparison_fn_t)ldb_dn_compare);
+
+       for (i=0; i<el->num_values; i++) {
+               if (ldb_dn_compare_base(nc_dns[i], dn) == 0) {
+                      (*nc_root) = talloc_steal(mem_ctx, nc_dns[i]);
+                       talloc_free(tmp_ctx);
+                       return LDB_SUCCESS;
+               }
+       }
+
+       talloc_free(tmp_ctx);
+       return LDB_ERR_NO_SUCH_OBJECT;
+}