s4:ldap_server: add call->wait_send/recv infrastructure

If it is set by the dispatch functions, the core server
will use call->wait_send() and wait for it to finally
return frim call->wait_recv() before it asks for the
next incoming pdu.

This can be used to implement bind as async operations.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

2 files changed, 63 insertions, 2 deletions

diff --git a/source4/ldap_server/ldap_server.c b/source4/ldap_server/ldap_server.c
index 062c3fc4b56..6a6053206b2 100644
--- a/source4/ldap_server/ldap_server.c
+++ b/source4/ldap_server/ldap_server.c
@@ -578,7 +578,8 @@ static void ldapsrv_call_read_done(struct tevent_req *subreq)
 	conn->active_call = subreq;
 }
 
-
+static void ldapsrv_call_wait_done(struct tevent_req *subreq);
+static void ldapsrv_call_writev_start(struct ldapsrv_call *call);
 static void ldapsrv_call_writev_done(struct tevent_req *subreq);
 
 static void ldapsrv_call_process_done(struct tevent_req *subreq)
@@ -588,7 +589,6 @@ static void ldapsrv_call_process_done(struct tevent_req *subreq)
 		struct ldapsrv_call);
 	struct ldapsrv_connection *conn = call->conn;
 	NTSTATUS status;
-	DATA_BLOB blob = data_blob_null;
 
 	conn->active_call = NULL;
 
@@ -599,6 +599,61 @@ static void ldapsrv_call_process_done(struct tevent_req *subreq)
 		return;
 	}
 
+	if (call->wait_send != NULL) {
+		subreq = call->wait_send(call,
+					 conn->connection->event.ctx,
+					 call->wait_private);
+		if (subreq == NULL) {
+			ldapsrv_terminate_connection(conn,
+					"ldapsrv_call_process_done: "
+					"call->wait_send - no memory");
+			return;
+		}
+		tevent_req_set_callback(subreq,
+					ldapsrv_call_wait_done,
+					call);
+		conn->active_call = subreq;
+		return;
+	}
+
+	ldapsrv_call_writev_start(call);
+}
+
+static void ldapsrv_call_wait_done(struct tevent_req *subreq)
+{
+	struct ldapsrv_call *call =
+		tevent_req_callback_data(subreq,
+		struct ldapsrv_call);
+	struct ldapsrv_connection *conn = call->conn;
+	NTSTATUS status;
+
+	conn->active_call = NULL;
+
+	status = call->wait_recv(subreq);
+	TALLOC_FREE(subreq);
+	if (!NT_STATUS_IS_OK(status)) {
+		const char *reason;
+
+		reason = talloc_asprintf(call, "ldapsrv_call_wait_done: "
+					 "call->wait_recv() - %s",
+					 nt_errstr(status));
+		if (reason == NULL) {
+			reason = nt_errstr(status);
+		}
+
+		ldapsrv_terminate_connection(conn, reason);
+		return;
+	}
+
+	ldapsrv_call_writev_start(call);
+}
+
+static void ldapsrv_call_writev_start(struct ldapsrv_call *call)
+{
+	struct ldapsrv_connection *conn = call->conn;
+	DATA_BLOB blob = data_blob_null;
+	struct tevent_req *subreq = NULL;
+
 	/* build all the replies into a single blob */
 	while (call->replies) {
 		DATA_BLOB b;
diff --git a/source4/ldap_server/ldap_server.h b/source4/ldap_server/ldap_server.h
index 337c974aaae..d3e31fb1eec 100644
--- a/source4/ldap_server/ldap_server.h
+++ b/source4/ldap_server/ldap_server.h
@@ -73,6 +73,12 @@ struct ldapsrv_call {
 	} *replies;
 	struct iovec out_iov;
 
+	struct tevent_req *(*wait_send)(TALLOC_CTX *mem_ctx,
+					struct tevent_context *ev,
+					void *private_data);
+	NTSTATUS (*wait_recv)(struct tevent_req *req);
+	void *wait_private;
+
 	struct tevent_req *(*postprocess_send)(TALLOC_CTX *mem_ctx,
 					       struct tevent_context *ev,
 					       void *private_data);