winbind: use tevent_queue_wait_send/recv in wb_child_request_*()

We need a way to keep the child->queue blocked without relying on
the current 'req' (wb_child_request_state).

The next commit will make use of this.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13290

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

diff --git a/source3/winbindd/winbindd_dual.c b/source3/winbindd/winbindd_dual.c
index 7fb5aa899e42edb8f76f756e4f94e2eb0ebdbd78..fa5b5b0589eb7aff07c14c2e941ba57449346ff9 100644 (file)
--- a/source3/winbindd/winbindd_dual.c
+++ b/source3/winbindd/winbindd_dual.c
@@ -119,6 +119,7 @@ static NTSTATUS child_write_response(int sock, struct winbindd_response *wrsp)
 
 struct wb_child_request_state {
        struct tevent_context *ev;
+       struct tevent_req *queue_subreq;
        struct tevent_req *subreq;
        struct winbindd_child *child;
        struct winbindd_request *request;
@@ -127,8 +128,7 @@ struct wb_child_request_state {
 
 static bool fork_domain_child(struct winbindd_child *child);
 
-static void wb_child_request_trigger(struct tevent_req *req,
-                                           void *private_data);
+static void wb_child_request_waited(struct tevent_req *subreq);
 static void wb_child_request_done(struct tevent_req *subreq);
 
 static void wb_child_request_cleanup(struct tevent_req *req,
@@ -141,6 +141,7 @@ struct tevent_req *wb_child_request_send(TALLOC_CTX *mem_ctx,
 {
        struct tevent_req *req;
        struct wb_child_request_state *state;
+       struct tevent_req *subreq;
 
        req = tevent_req_create(mem_ctx, &state,
                                struct wb_child_request_state);
@@ -152,23 +153,36 @@ struct tevent_req *wb_child_request_send(TALLOC_CTX *mem_ctx,
        state->child = child;
        state->request = request;
 
-       if (!tevent_queue_add(child->queue, ev, req,
-                             wb_child_request_trigger, NULL)) {
-               tevent_req_oom(req);
+       subreq = tevent_queue_wait_send(state, ev, child->queue);
+       if (tevent_req_nomem(subreq, req)) {
                return tevent_req_post(req, ev);
        }
+       tevent_req_set_callback(subreq, wb_child_request_waited, req);
+       state->queue_subreq = subreq;
 
        tevent_req_set_cleanup_fn(req, wb_child_request_cleanup);
 
        return req;
 }
 
-static void wb_child_request_trigger(struct tevent_req *req,
-                                    void *private_data)
+static void wb_child_request_waited(struct tevent_req *subreq)
 {
+       struct tevent_req *req = tevent_req_callback_data(
+               subreq, struct tevent_req);
        struct wb_child_request_state *state = tevent_req_data(
                req, struct wb_child_request_state);
-       struct tevent_req *subreq;
+       bool ok;
+
+       ok = tevent_queue_wait_recv(subreq);
+       if (!ok) {
+               tevent_req_oom(req);
+               return;
+       }
+       /*
+        * We need to keep state->queue_subreq
+        * in order to block the queue.
+        */
+       subreq = NULL;
 
        if ((state->child->sock == -1) && (!fork_domain_child(state->child))) {
                tevent_req_error(req, errno);
@@ -231,6 +245,7 @@ static void wb_child_request_cleanup(struct tevent_req *req,
        }
 
        TALLOC_FREE(state->subreq);
+       TALLOC_FREE(state->queue_subreq);
 
        if (req_state == TEVENT_REQ_DONE) {
                /* transmitted request and got response */