winbindd: use struct winbindd_domain_ref in struct wbint_bh_raw_call_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.

Note this is most likely not really needed because
the requests are in the domain or child tevent queue,
before the domain will be free'ed.
But we better use the winbindd_domain_ref in
all async state!

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

diff --git a/source3/winbindd/winbindd_dual_ndr.c b/source3/winbindd/winbindd_dual_ndr.c
index 2d45238557263096f337baf86d0edba240369c25..a1ce38c8bd1f3e25d29e789d5d81dc02fec484c8 100644 (file)
--- a/source3/winbindd/winbindd_dual_ndr.c
+++ b/source3/winbindd/winbindd_dual_ndr.c
@@ -71,7 +71,7 @@ static uint32_t wbint_bh_set_timeout(struct dcerpc_binding_handle *h,
 }
 
 struct wbint_bh_raw_call_state {
-       struct winbindd_domain *domain;
+       struct winbindd_domain_ref domain;
        uint32_t opnum;
        DATA_BLOB in_data;
        struct winbindd_request request;
@@ -104,7 +104,7 @@ static struct tevent_req *wbint_bh_raw_call_send(TALLOC_CTX *mem_ctx,
        if (req == NULL) {
                return NULL;
        }
-       state->domain = hs->domain;
+       winbindd_domain_ref_set(&state->domain, hs->domain);
        state->opnum = opnum;
        state->in_data.data = discard_const_p(uint8_t, in_data);
        state->in_data.length = in_length;
@@ -115,11 +115,11 @@ static struct tevent_req *wbint_bh_raw_call_send(TALLOC_CTX *mem_ctx,
                return tevent_req_post(req, ev);
        }
 
-       if ((state->domain != NULL)
-           && wcache_fetch_ndr(state, state->domain, state->opnum,
+       if ((hs->domain != NULL)
+           && wcache_fetch_ndr(state, hs->domain, state->opnum,
                                &state->in_data, &state->out_data)) {
                DBG_DEBUG("Got opnum %"PRIu32" for domain %s from cache\n",
-                         state->opnum, state->domain->name);
+                         state->opnum, hs->domain->name);
                tevent_req_done(req);
                return tevent_req_post(req, ev);
        }
@@ -188,6 +188,8 @@ static void wbint_bh_raw_call_domain_done(struct tevent_req *subreq)
                tevent_req_data(req,
                struct wbint_bh_raw_call_state);
        int ret, err;
+       struct winbindd_domain *domain = NULL;
+       bool valid;
 
        ret = wb_domain_request_recv(subreq, state, &state->response, &err);
        TALLOC_FREE(subreq);
@@ -205,8 +207,16 @@ static void wbint_bh_raw_call_domain_done(struct tevent_req *subreq)
                return;
        }
 
-       if (state->domain != NULL) {
-               wcache_store_ndr(state->domain, state->opnum,
+       valid = winbindd_domain_ref_get(&state->domain, &domain);
+       if (!valid) {
+               /*
+                * winbindd_domain_ref_get() already generated
+                * a debug message for the stale domain!
+                *
+                * Just don't fill the cache
+                */
+       } else {
+               wcache_store_ndr(domain, state->opnum,
                                 &state->in_data, &state->out_data);
        }