s4-ldb: Implement ldb_msg_diff_ex() function to accept a memory context from client

[kamenim/samba.git] / source4 / lib / ldb / common / ldb_msg.c

diff --git a/source4/lib/ldb/common/ldb_msg.c b/source4/lib/ldb/common/ldb_msg.c
index 4d0149af8f45d77aac36fcfeb817b0ea399e3817..e54caa8811a31cc6b7df9f38b8cc46e3aca3d629 100644 (file)
--- a/source4/lib/ldb/common/ldb_msg.c
+++ b/source4/lib/ldb/common/ldb_msg.c
@@ -642,6 +642,98 @@ struct ldb_message *ldb_msg_diff(struct ldb_context *ldb,
        return mod;
 }
 
+/**
+ * return a ldb_message representing the differences between msg1 and msg2.
+ * If you then use this in a ldb_modify() call it can be used to save edits to a message
+ *
+ * Result message is constructed as follows:
+ * - LDB_FLAG_MOD_ADD     - elements found only in msg2
+ * - LDB_FLAG_MOD_REPLACE - elements in msg2 that have different value in msg1
+ *                          Value for msg2 element is used
+ * - LDB_FLAG_MOD_DELETE  - elements found only in msg2
+ *
+ * @return LDB_SUCCESS or LDB_ERR_OPERATIONS_ERROR
+ */
+int ldb_msg_diff_ex(struct ldb_context *ldb,
+                   struct ldb_message *msg1,
+                   struct ldb_message *msg2,
+                   TALLOC_CTX *mem_ctx,
+                   struct ldb_message **_msg_out)
+{
+       int ldb_res;
+       unsigned int i;
+       struct ldb_message *mod;
+       struct ldb_message_element *el;
+       TALLOC_CTX *temp_ctx;
+
+       temp_ctx = talloc_new(mem_ctx);
+       if (!temp_ctx) {
+               return LDB_ERR_OPERATIONS_ERROR;
+       }
+
+       mod = ldb_msg_new(temp_ctx);
+       if (mod == NULL) {
+               goto failed;
+       }
+
+       mod->dn = msg1->dn;
+       mod->num_elements = 0;
+       mod->elements = NULL;
+
+       /* canonicalize msg2 so we have no
+        * repeated elements */
+       msg2 = ldb_msg_canonicalize(ldb, msg2);
+       if (msg2 == NULL) {
+               goto failed;
+       }
+
+       /* steal msg2 into mod context as it is
+        * allocated in ldb's context */
+       talloc_steal(mod, msg2);
+
+       /* look in msg2 to find elements that need to be added
+          or modified */
+       for (i=0;i<msg2->num_elements;i++) {
+               el = ldb_msg_find_element(msg1, msg2->elements[i].name);
+
+               if (el && ldb_msg_element_compare(el, &msg2->elements[i]) == 0) {
+                       continue;
+               }
+
+               ldb_res = ldb_msg_add(mod,
+                                     &msg2->elements[i],
+                                     el ? LDB_FLAG_MOD_REPLACE : LDB_FLAG_MOD_ADD);
+               if (ldb_res != LDB_SUCCESS) {
+                       goto failed;
+               }
+       }
+
+       /* look in msg1 to find elements that need to be deleted */
+       for (i=0;i<msg1->num_elements;i++) {
+               el = ldb_msg_find_element(msg2, msg1->elements[i].name);
+               if (el == NULL) {
+                       ldb_res = ldb_msg_add_empty(mod,
+                                                   msg1->elements[i].name,
+                                                   LDB_FLAG_MOD_DELETE, NULL);
+                       if (ldb_res != LDB_SUCCESS) {
+                               goto failed;
+                       }
+               }
+       }
+
+       /* steal resulting message into supplied context */
+       talloc_steal(mem_ctx, mod);
+       *_msg_out = mod;
+
+       talloc_free(temp_ctx);
+       return LDB_SUCCESS;
+
+failed:
+       talloc_free(temp_ctx);
+       return LDB_ERR_OPERATIONS_ERROR;
+}
+
+
 int ldb_msg_sanity_check(struct ldb_context *ldb, 
                         const struct ldb_message *msg)
 {