# HG changeset patch
# User Rob Hoes <rob.hoes@xxxxxxxxxx>
Hosts in a pool should use the same networking backend

This patch adds the following restrictions in order to prevent (as much as possible) trouble caused by hosts in a pool not having the same network backends (bridge/openvswitch):
1. Block pool join if the network backend of the joining host is not the same as the master's.
2. Block tunnel.create if at least one of the hosts in the pool uses the bridging backend.

Signed-off-by: Rob Hoes <rob.hoes@xxxxxxxxxx>

diff -r 57c8f8bc6e2e ocaml/idl/datamodel.ml
--- a/ocaml/idl/datamodel.ml
+++ b/ocaml/idl/datamodel.ml
@@ -451,7 +451,7 @@
     ~doc:"The specified device was not found." ();
 
   error Api_errors.openvswitch_not_active []
-    ~doc:"This operation needs the OpenVSwitch networking backend to be enabled." ();
+    ~doc:"This operation needs the OpenVSwitch networking backend to be enabled on all hosts in the pool." ();
   error Api_errors.transport_pif_not_configured ["PIF"]
     ~doc:"The tunnel transport PIF has no IP configuration set." ();
   error Api_errors.is_tunnel_access_pif ["PIF"]
diff -r 57c8f8bc6e2e ocaml/xapi/xapi_pool.ml
--- a/ocaml/xapi/xapi_pool.ml
+++ b/ocaml/xapi/xapi_pool.ml
@@ -227,7 +227,20 @@
 			let pool = List.hd (Client.Pool.get_all rpc session_id) in
 			let controller = Client.Pool.get_vswitch_controller ~rpc ~session_id ~self:pool in
 			if my_controller <> controller && my_controller <> "" then
-				raise (Api_errors.Server_error(Api_errors.operation_not_allowed, ["vswitch controller address differs"]))
+				raise (Api_errors.Server_error(Api_errors.operation_not_allowed, ["vswitch controller address differs"]));
+
+			(* The network backend must be the same as the remote master's backend *)
+			let my_backend = Netdev.string_of_kind Netdev.network.Netdev.kind in
+			let remote_master = Client.Pool.get_master ~rpc ~session_id ~self:pool in
+			let remote_masters_backend =
+				let v = Client.Host.get_software_version ~rpc ~session_id ~self:remote_master in
+				if not (List.mem_assoc "network_backend" v) then
+					Netdev.string_of_kind Netdev.Bridge
+				else
+					List.assoc "network_backend" v
+			in
+			if my_backend <> remote_masters_backend then
+				raise (Api_errors.Server_error(Api_errors.operation_not_allowed, ["Network backends differ"]));
 		| _ -> ()
 	in
 
diff -r 57c8f8bc6e2e ocaml/xapi/xapi_tunnel.ml
--- a/ocaml/xapi/xapi_tunnel.ml
+++ b/ocaml/xapi/xapi_tunnel.ml
@@ -28,8 +28,13 @@
 	let pool = Helpers.get_pool ~__context in
 	let host = Db.PIF.get_host ~__context ~self:transport_PIF in
 	Xapi_pif.assert_no_other_local_pifs ~__context ~host ~network;
-	if Netdev.network.Netdev.kind <> Netdev.Vswitch then
-		raise (Api_errors.Server_error (Api_errors.openvswitch_not_active, []));
+	let hosts = Db.Host.get_all ~__context in
+	List.iter
+		(fun h ->
+			let v = Db.Host.get_software_version ~__context ~self:h in
+			if not (List.mem_assoc "network_backend" v && List.assoc "network_backend" v = "openvswitch") then
+				raise (Api_errors.Server_error (Api_errors.openvswitch_not_active, []));
+		) hosts;
 	if Db.PIF.get_tunnel_access_PIF_of ~__context ~self:transport_PIF <> [] then
 		raise (Api_errors.Server_error (Api_errors.is_tunnel_access_pif, [Ref.string_of transport_PIF]));
 	let tunnel = Ref.make () in