Move the uid2sid cache to the parent winbind process

(This used to be commit 6e885aeabba2265a06b726f567cb14dde12c8ccb)

3 files changed, 160 insertions, 19 deletions

diff --git a/source3/winbindd/idmap_cache.c b/source3/winbindd/idmap_cache.c
index f7e1d4e6d1..027ce3b619 100644
--- a/source3/winbindd/idmap_cache.c
+++ b/source3/winbindd/idmap_cache.c
@@ -521,3 +521,83 @@ done:
 	return ret;
 }
 
+bool idmap_cache_find_sid2uid(const struct dom_sid *sid, uid_t *puid,
+			      bool *expired)
+{
+	fstring sidstr;
+	char *key;
+	char *value;
+	char *endptr;
+	time_t timeout;
+	uid_t uid;
+	bool ret;
+
+	key = talloc_asprintf(talloc_tos(), "IDMAP/SID2UID/%s",
+			      sid_to_fstring(sidstr, sid));
+	if (key == NULL) {
+		return false;
+	}
+	ret = gencache_get(key, &value, &timeout);
+	TALLOC_FREE(key);
+	if (!ret) {
+		return false;
+	}
+	uid = strtol(value, &endptr, 10);
+	ret = (*endptr == '\0');
+	SAFE_FREE(value);
+	if (ret) {
+		*puid = uid;
+		*expired = (timeout <= time(NULL));
+	}
+	return ret;
+}
+
+bool idmap_cache_find_uid2sid(uid_t uid, struct dom_sid *sid, bool *expired)
+{
+	char *key;
+	char *value;
+	time_t timeout;
+	bool ret;
+
+	key = talloc_asprintf(talloc_tos(), "IDMAP/UID2SID/%d", (int)uid);
+	if (key == NULL) {
+		return false;
+	}
+	ret = gencache_get(key, &value, &timeout);
+	TALLOC_FREE(key);
+	if (!ret) {
+		return false;
+	}
+	ZERO_STRUCTP(sid);
+	ret = string_to_sid(sid, value);
+	SAFE_FREE(value);
+	if (ret) {
+		*expired = (timeout <= time(NULL));
+	}
+	return ret;
+}
+
+void idmap_cache_set_sid2uid(const struct dom_sid *sid, uid_t uid)
+{
+	time_t now = time(NULL);
+	time_t timeout;
+	fstring sidstr, key, value;
+
+	if (!is_null_sid(sid)) {
+		fstr_sprintf(key, "IDMAP/SID2UID/%s",
+			     sid_to_fstring(sidstr, sid));
+		fstr_sprintf(value, "%d", (int)uid);
+		timeout = (uid == -1)
+			? lp_idmap_negative_cache_time()
+			: lp_idmap_cache_time();
+		gencache_set(key, value, now + timeout);
+	}
+	if (uid != -1) {
+		fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)uid);
+		sid_to_fstring(value, sid);
+		timeout = is_null_sid(sid)
+			? lp_idmap_negative_cache_time()
+			: lp_idmap_cache_time();
+		gencache_set(key, value, now + timeout);
+	}
+}
diff --git a/source3/winbindd/winbindd.h b/source3/winbindd/winbindd.h
index b2fe8b67e7..f6f269ee6d 100644
--- a/source3/winbindd/winbindd.h
+++ b/source3/winbindd/winbindd.h
@@ -379,4 +379,6 @@ enum ent_type {
 #define IS_DOMAIN_OFFLINE(x) ( lp_winbind_offline_logon() && \
 			       ( get_global_winbindd_state_offline() \
 				 || !(x)->online ) )
+#define IS_DOMAIN_ONLINE(x) (!IS_DOMAIN_OFFLINE(x))
+
 #endif /* _WINBINDD_H */
diff --git a/source3/winbindd/winbindd_sid.c b/source3/winbindd/winbindd_sid.c
index 0e8e6ca00b..ce34dadf4c 100644
--- a/source3/winbindd/winbindd_sid.c
+++ b/source3/winbindd/winbindd_sid.c
@@ -159,14 +159,19 @@ static void sid2uid_recv(void *private_data, bool success, uid_t uid)
 {
 	struct winbindd_cli_state *state =
 		talloc_get_type_abort(private_data, struct winbindd_cli_state);
+	struct dom_sid sid;
+
+	string_to_sid(&sid, state->request.data.sid);
 
 	if (!success) {
 		DEBUG(5, ("Could not convert sid %s\n",
 			  state->request.data.sid));
+		idmap_cache_set_sid2uid(&sid, -1);
 		request_error(state);
 		return;
 	}
 
+	idmap_cache_set_sid2uid(&sid, uid);
 	state->response.data.uid = uid;
 	request_ok(state);
 }
@@ -180,34 +185,40 @@ static void sid2uid_lookupsid_recv( void *private_data, bool success,
 		talloc_get_type_abort(private_data, struct winbindd_cli_state);
 	DOM_SID sid;
 
+	if (!string_to_sid(&sid, state->request.data.sid)) {
+		DEBUG(1, ("sid2uid_lookupsid_recv: Could not get convert sid "
+			  "%s from string\n", state->request.data.sid));
+		request_error(state);
+		return;
+	}
+
 	if (!success) {
 		DEBUG(5, ("sid2uid_lookupsid_recv Could not convert get sid type for %s\n",
 			  state->request.data.sid));
-		request_error(state);
-		return;
+		goto fail;
 	}
 
 	if ( (type!=SID_NAME_USER) && (type!=SID_NAME_COMPUTER) ) {
 		DEBUG(5,("sid2uid_lookupsid_recv: Sid %s is not a user or a computer.\n", 
 			 state->request.data.sid));
-		request_error(state);
-		return;		
+		goto fail;
 	}
 
-	if (!string_to_sid(&sid, state->request.data.sid)) {
-		DEBUG(1, ("sid2uid_lookupsid_recv: Could not get convert sid %s from string\n",
-			  state->request.data.sid));
-		request_error(state);
-		return;
-	}
-	
 	/* always use the async interface (may block) */
 	winbindd_sid2uid_async(state->mem_ctx, &sid, sid2uid_recv, state);
+	return;
+
+ fail:
+	idmap_cache_set_sid2uid(&sid, -1);
+	request_error(state);
+	return;
 }
 
 void winbindd_sid_to_uid(struct winbindd_cli_state *state)
 {
 	DOM_SID sid;
+	uid_t uid;
+	bool expired;
 
 	/* Ensure null termination */
 	state->request.data.sid[sizeof(state->request.data.sid)-1]='\0';
@@ -222,10 +233,29 @@ void winbindd_sid_to_uid(struct winbindd_cli_state *state)
 		return;
 	}
 
+	if (idmap_cache_find_sid2uid(&sid, &uid, &expired)) {
+		DEBUG(10, ("idmap_cache_find_sid2uid found %d%s\n",
+			   (int)uid, expired ? " (expired)": ""));
+		if (expired && IS_DOMAIN_ONLINE(find_our_domain())) {
+			DEBUG(10, ("revalidating expired entry\n"));
+			goto backend;
+		}
+		if (uid == -1) {
+			DEBUG(10, ("Returning negative cache entry\n"));
+			request_error(state);
+			return;
+		}
+		DEBUG(10, ("Returning positive cache entry\n"));
+		state->response.data.uid = uid;
+		request_ok(state);
+		return;
+	}
+
 	/* Validate the SID as a user.  Hopefully this will hit cache.
 	   Needed to prevent DoS by exhausting the uid allocation
 	   range from random SIDs. */
 
+ backend:
 	winbindd_lookupsid_async( state->mem_ctx, &sid, sid2uid_lookupsid_recv, state );
 }
 
@@ -411,30 +441,59 @@ void winbindd_set_hwm(struct winbindd_cli_state *state)
 
 /* Convert a uid to a sid */
 
-static void uid2sid_recv(void *private_data, bool success, const char *sid)
+static void uid2sid_recv(void *private_data, bool success, const char *sidstr)
 {
 	struct winbindd_cli_state *state =
 		(struct winbindd_cli_state *)private_data;
+	struct dom_sid sid;
 
-	if (success) {
-		DEBUG(10,("uid2sid: uid %lu has sid %s\n",
-			  (unsigned long)(state->request.data.uid), sid));
-		fstrcpy(state->response.data.sid.sid, sid);
-		state->response.data.sid.type = SID_NAME_USER;
-		request_ok(state);
+	if (!success || !string_to_sid(&sid, sidstr)) {
+		ZERO_STRUCT(sid);
+		idmap_cache_set_sid2uid(&sid, state->request.data.uid);
+		request_error(state);
 		return;
 	}
 
-	request_error(state);
+	DEBUG(10,("uid2sid: uid %lu has sid %s\n",
+		  (unsigned long)(state->request.data.uid), sidstr));
+
+	idmap_cache_set_sid2uid(&sid, state->request.data.uid);
+	fstrcpy(state->response.data.sid.sid, sidstr);
+	state->response.data.sid.type = SID_NAME_USER;
+	request_ok(state);
 	return;
 }
 
 void winbindd_uid_to_sid(struct winbindd_cli_state *state)
 {
+	struct dom_sid sid;
+	bool expired;
+
 	DEBUG(3, ("[%5lu]: uid to sid %lu\n", (unsigned long)state->pid, 
 		  (unsigned long)state->request.data.uid));
 
+	if (idmap_cache_find_uid2sid(state->request.data.uid, &sid,
+				     &expired)) {
+		DEBUG(10, ("idmap_cache_find_uid2sid found %d%s\n",
+			   (int)state->request.data.uid,
+			   expired ? " (expired)": ""));
+		if (expired && IS_DOMAIN_ONLINE(find_our_domain())) {
+			DEBUG(10, ("revalidating expired entry\n"));
+			goto backend;
+		}
+		if (is_null_sid(&sid)) {
+			DEBUG(10, ("Returning negative cache entry\n"));
+			request_error(state);
+			return;
+		}
+		DEBUG(10, ("Returning positive cache entry\n"));
+		sid_to_fstring(state->response.data.sid.sid, &sid);
+		request_ok(state);
+		return;
+	}
+
 	/* always go via the async interface (may block) */
+ backend:
 	winbindd_uid2sid_async(state->mem_ctx, state->request.data.uid, uid2sid_recv, state);
 }