winbindd: use struct winbindd_domain_ref in struct wb_query_user_list_state

In the next commits it will be possible that
struct winbindd_domain instances become stale
because trusted domains were reloaded.

That means aync state structure should not use
pointers to 'struct winbindd_domain' as they
can become stale!

Instead they should use 'struct winbindd_domain_ref domain'
in the async state and use winbindd_domain_ref_set/get()
to manage the 'struct winbindd_domain' pointer.

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

diff --git a/source3/winbindd/wb_query_user_list.c b/source3/winbindd/wb_query_user_list.c
index c3f52e5881f0cb05411e1ef13e8a16981eafaeda..6813dc1214e11378cfa871115871bb59eff6e489 100644 (file)
--- a/source3/winbindd/wb_query_user_list.c
+++ b/source3/winbindd/wb_query_user_list.c
@@ -24,7 +24,7 @@
 
 struct wb_query_user_list_state {
        struct tevent_context *ev;
-       struct winbindd_domain *domain;
+       struct winbindd_domain_ref domain;
        struct wbint_RidArray rids;
        const char *domain_name;
        struct wbint_Principals names;
@@ -50,7 +50,7 @@ struct tevent_req *wb_query_user_list_send(TALLOC_CTX *mem_ctx,
        D_INFO("WB command user_list start.\nQuery users in domain %s.\n",
               domain->name);
        state->ev = ev;
-       state->domain = domain;
+       winbindd_domain_ref_set(&state->domain, domain);
 
        subreq = dcerpc_wbint_QueryUserRidList_send(
                state, ev, dom_child_handle(domain), &state->rids);
@@ -67,7 +67,9 @@ static void wb_query_user_list_gotrids(struct tevent_req *subreq)
                subreq, struct tevent_req);
        struct wb_query_user_list_state *state = tevent_req_data(
                req, struct wb_query_user_list_state);
+       struct winbindd_domain *domain = NULL;
        NTSTATUS status, result;
+       bool valid;
 
        status = dcerpc_wbint_QueryUserRidList_recv(subreq, state, &result);
        TALLOC_FREE(subreq);
@@ -76,12 +78,22 @@ static void wb_query_user_list_gotrids(struct tevent_req *subreq)
                return;
        }
 
+       valid = winbindd_domain_ref_get(&state->domain, &domain);
+       if (!valid) {
+               /*
+                * winbindd_domain_ref_get() already generated
+                * a debug message for the stale domain!
+                */
+               tevent_req_nterror(req, NT_STATUS_NO_SUCH_DOMAIN);
+               return;
+       }
+
        D_DEBUG("dcerpc_wbint_QueryUserRidList returned %"PRIu32" users\n",
                state->rids.num_rids);
 
        subreq = dcerpc_wbint_LookupRids_send(
-               state, state->ev, dom_child_handle(state->domain),
-               &state->domain->sid, &state->rids,
+               state, state->ev, dom_child_handle(domain),
+               &domain->sid, &state->rids,
                &state->domain_name, &state->names);
        if (tevent_req_nomem(subreq, req)) {
                return;