winbindd: use struct winbindd_domain_ref in struct winbindd_domain_info_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/winbindd_domain_info.c b/source3/winbindd/winbindd_domain_info.c
index 5b3c46a9de57d64d9cef3de18bb2603144d2ff36..78dc180124b542f4778a5812b6e7bdf61308e1bc 100644 (file)
--- a/source3/winbindd/winbindd_domain_info.c
+++ b/source3/winbindd/winbindd_domain_info.c
@@ -24,7 +24,7 @@
 #include "librpc/gen_ndr/ndr_winbind_c.h"
 
 struct winbindd_domain_info_state {
-       struct winbindd_domain *domain;
+       struct winbindd_domain_ref domain;
        uint32_t in;
        uint32_t out;
 };
@@ -39,6 +39,7 @@ struct tevent_req *winbindd_domain_info_send(
 {
        struct tevent_req *req, *subreq;
        struct winbindd_domain_info_state *state;
+       struct winbindd_domain *domain = NULL;
 
        req = tevent_req_create(mem_ctx, &state,
                                struct winbindd_domain_info_state);
@@ -49,17 +50,18 @@ struct tevent_req *winbindd_domain_info_send(
        DEBUG(3, ("[%5lu]: domain_info [%s]\n", (unsigned long)cli->pid,
                  cli->request->domain_name));
 
-       state->domain = find_domain_from_name_noinit(
+       domain = find_domain_from_name_noinit(
                cli->request->domain_name);
 
-       if (state->domain == NULL) {
+       if (domain == NULL) {
                DEBUG(3, ("Did not find domain [%s]\n",
                          cli->request->domain_name));
                tevent_req_nterror(req, NT_STATUS_NO_SUCH_DOMAIN);
                return tevent_req_post(req, ev);
        }
+       winbindd_domain_ref_set(&state->domain, domain);
 
-       if (state->domain->initialized) {
+       if (domain->initialized) {
                tevent_req_done(req);
                return tevent_req_post(req, ev);
        }
@@ -72,7 +74,7 @@ struct tevent_req *winbindd_domain_info_send(
        state->out = 0;
        subreq = dcerpc_wbint_Ping_send(state,
                                        global_event_context(),
-                                       dom_child_handle(state->domain),
+                                       dom_child_handle(domain),
                                        state->in,
                                        &state->out);
        if (tevent_req_nomem(subreq, req)) {
@@ -90,6 +92,8 @@ static void winbindd_domain_info_done(struct tevent_req *subreq)
        struct winbindd_domain_info_state *state = tevent_req_data(
                req, struct winbindd_domain_info_state);
        NTSTATUS status, result;
+       struct winbindd_domain *domain = NULL;
+       bool valid;
 
        status = dcerpc_wbint_Ping_recv(subreq, state, &result);
        TALLOC_FREE(subreq);
@@ -105,9 +109,19 @@ static void winbindd_domain_info_done(struct tevent_req *subreq)
                return;
        }
 
-       if (!state->domain->initialized) {
+       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;
+       }
+
+       if (!domain->initialized) {
                DBG_INFO("dcerpc_wbint_Ping did not initialize domain %s\n",
-                        state->domain->name);
+                        domain->name);
                tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR);
                return;
        }
@@ -120,7 +134,8 @@ NTSTATUS winbindd_domain_info_recv(struct tevent_req *req,
 {
        struct winbindd_domain_info_state *state = tevent_req_data(
                req, struct winbindd_domain_info_state);
-       struct winbindd_domain *domain = state->domain;
+       struct winbindd_domain *domain = NULL;
+       bool valid;
        NTSTATUS status;
 
        if (tevent_req_is_nterror(req, &status)) {
@@ -129,6 +144,15 @@ NTSTATUS winbindd_domain_info_recv(struct tevent_req *req,
                return status;
        }
 
+       valid = winbindd_domain_ref_get(&state->domain, &domain);
+       if (!valid) {
+               /*
+                * winbindd_domain_ref_get() already generated
+                * a debug message for the stale domain!
+                */
+               return NT_STATUS_NO_SUCH_DOMAIN;
+       }
+
        fstrcpy(response->data.domain_info.name, domain->name);
        fstrcpy(response->data.domain_info.alt_name, domain->alt_name);
        sid_to_fstring(response->data.domain_info.sid, &domain->sid);