winbindd: use struct winbindd_domain_ref in struct winbindd_list_groups_domstate

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_list_groups.c b/source3/winbindd/winbindd_list_groups.c
index 272c6387349ea388442cdc713476863e1b5f0ea1..fba36e009968866b1925b6d4810c83ef921f5c18 100644 (file)
--- a/source3/winbindd/winbindd_list_groups.c
+++ b/source3/winbindd/winbindd_list_groups.c
@@ -24,7 +24,7 @@
 
 struct winbindd_list_groups_domstate {
        struct tevent_req *subreq;
-       struct winbindd_domain *domain;
+       struct winbindd_domain_ref domain;
        struct wbint_Principals groups;
 };
 
@@ -89,27 +89,37 @@ struct tevent_req *winbindd_list_groups_send(TALLOC_CTX *mem_ctx,
        if (request->domain_name[0] != '\0') {
                ZERO_STRUCT(state->domains[0].groups);
 
-               state->domains[0].domain = find_domain_from_name_noinit(
+               domain = find_domain_from_name_noinit(
                        request->domain_name);
-               if (state->domains[0].domain == NULL) {
+               if (domain == NULL) {
                        tevent_req_nterror(req, NT_STATUS_NO_SUCH_DOMAIN);
                        return tevent_req_post(req, ev);
                }
+               winbindd_domain_ref_set(&state->domains[0].domain,
+                                       domain);
        } else {
                i = 0;
                for (domain = domain_list(); domain; domain = domain->next) {
                        ZERO_STRUCT(state->domains[i].groups);
 
-                       state->domains[i].domain = domain;
+                       winbindd_domain_ref_set(&state->domains[i].domain,
+                                               domain);
                        i++;
                }
        }
 
        for (i=0; i<state->num_domains; i++) {
                struct winbindd_list_groups_domstate *d = &state->domains[i];
+               bool valid;
+
+               /*
+                * We set the ref a few lines above, it must be valid!
+                */
+               valid = winbindd_domain_ref_get(&d->domain, &domain);
+               SMB_ASSERT(valid);
 
                d->subreq = dcerpc_wbint_QueryGroupList_send(
-                       state->domains, ev, dom_child_handle(d->domain),
+                       state->domains, ev, dom_child_handle(domain),
                        &d->groups);
                if (tevent_req_nomem(d->subreq, req)) {
                        TALLOC_FREE(state->domains);
@@ -141,19 +151,33 @@ static void winbindd_list_groups_done(struct tevent_req *subreq)
        }
        if (i < state->num_domains) {
                struct winbindd_list_groups_domstate *d = &state->domains[i];
+               struct winbindd_domain *domain = NULL;
+               bool valid;
+
+               valid = winbindd_domain_ref_get(&d->domain, &domain);
+               if (!valid) {
+                       /*
+                        * winbindd_domain_ref_get() already generated
+                        * a debug message for the stale domain!
+                        */
+                       d->subreq = NULL;
+                       d->groups.num_principals = 0;
+                       goto skip;
+               }
 
-               D_DEBUG("Domain %s returned %"PRIu32" groups\n", d->domain->name,
+               D_DEBUG("Domain %s returned %"PRIu32" groups\n", domain->name,
                           d->groups.num_principals);
 
                d->subreq = NULL;
 
                if (!NT_STATUS_IS_OK(status) || !NT_STATUS_IS_OK(result)) {
                        D_WARNING("list_groups for domain %s failed\n",
-                                  d->domain->name);
+                                  domain->name);
                        d->groups.num_principals = 0;
                }
        }
 
+skip:
        TALLOC_FREE(subreq);
 
        state->num_received += 1;
@@ -183,10 +207,22 @@ NTSTATUS winbindd_list_groups_recv(struct tevent_req *req,
        response->data.num_entries = 0;
        for (i=0; i<state->num_domains; i++) {
                struct winbindd_list_groups_domstate *d = &state->domains[i];
+               struct winbindd_domain *domain = NULL;
+               bool valid;
+
+               valid = winbindd_domain_ref_get(&d->domain, &domain);
+               if (!valid) {
+                       /*
+                        * winbindd_domain_ref_get() already generated
+                        * a debug message for the stale domain!
+                        */
+                       d->groups.num_principals = 0;
+                       continue;
+               }
 
                for (j=0; j<d->groups.num_principals; j++) {
                        const char *name;
-                       name = fill_domain_username_talloc(response, d->domain->name,
+                       name = fill_domain_username_talloc(response, domain->name,
                                             d->groups.principals[j].name,
                                             True);
                        if (name == NULL) {
@@ -205,11 +241,23 @@ NTSTATUS winbindd_list_groups_recv(struct tevent_req *req,
        len = 0;
        for (i=0; i<state->num_domains; i++) {
                struct winbindd_list_groups_domstate *d = &state->domains[i];
+               struct winbindd_domain *domain = NULL;
+               bool valid;
+
+               valid = winbindd_domain_ref_get(&d->domain, &domain);
+               if (!valid) {
+                       /*
+                        * winbindd_domain_ref_get() already generated
+                        * a debug message for the stale domain!
+                        */
+                       d->groups.num_principals = 0;
+                       continue;
+               }
 
                for (j=0; j<d->groups.num_principals; j++) {
                        const char *name;
                        size_t this_len;
-                       name = fill_domain_username_talloc(response, d->domain->name,
+                       name = fill_domain_username_talloc(response, domain->name,
                                             d->groups.principals[j].name,
                                             True);
                        if (name == NULL) {