Mailing List Archive

[PATCH 1 of 4 V2] oxenstored: handle unknown operations by returning an error to the client
# HG changeset patch
# User Ian Campbell <ian.campbell@citrix.com>
# Date 1323792488 0
# Node ID 06c6ba6641640a2fa0ef6f998405f5f7c43bb258
# Parent 74ab4d0c8ebac8d9d344dab3bf440f510d23377d
oxenstored: handle unknown operations by returning an error to the client

Previous an unknown operation would be decoded as a Not_found exception which
would bubble all the way up to the try ... with surrounding the call to
main_loop where it would be logged and ignored.

This would leave the guest hanging waiting for a response to the invalid
request.

Instead introduce a specific "Invalid" operation. Higher level functionality,
such as Process.process_packet, already handles operations which are not
understood with an error reply due to the final wildcard entry in
Process.function_of_type but explicitly handle Invalid this way to make it
clear what is going on.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>

diff -r 74ab4d0c8eba -r 06c6ba664164 tools/ocaml/libs/xb/op.ml
--- a/tools/ocaml/libs/xb/op.ml Tue Dec 13 16:07:40 2011 +0000
+++ b/tools/ocaml/libs/xb/op.ml Tue Dec 13 16:08:08 2011 +0000
@@ -19,8 +19,7 @@ type operation = Debug | Directory | Rea
Transaction_end | Introduce | Release |
Getdomainpath | Write | Mkdir | Rm |
Setperms | Watchevent | Error | Isintroduced |
- Resume | Set_target
- | Restrict
+ Resume | Set_target | Restrict | Invalid

let operation_c_mapping =
[| Debug; Directory; Read; Getperms;
@@ -41,7 +40,7 @@ let array_search el a =
let of_cval i =
if i >= 0 && i < size
then operation_c_mapping.(i)
- else raise Not_found
+ else Invalid

let to_cval op =
array_search op operation_c_mapping
@@ -69,3 +68,4 @@ let to_string ty =
| Resume -> "RESUME"
| Set_target -> "SET_TARGET"
| Restrict -> "RESTRICT"
+ | Invalid -> "INVALID"
diff -r 74ab4d0c8eba -r 06c6ba664164 tools/ocaml/libs/xb/xb.mli
--- a/tools/ocaml/libs/xb/xb.mli Tue Dec 13 16:07:40 2011 +0000
+++ b/tools/ocaml/libs/xb/xb.mli Tue Dec 13 16:08:08 2011 +0000
@@ -23,6 +23,7 @@ module Op :
| Resume
| Set_target
| Restrict
+ | Invalid (* Not a valid wire operation *)
val operation_c_mapping : operation array
val size : int
val array_search : 'a -> 'a array -> int
diff -r 74ab4d0c8eba -r 06c6ba664164 tools/ocaml/xenstored/logging.ml
--- a/tools/ocaml/xenstored/logging.ml Tue Dec 13 16:07:40 2011 +0000
+++ b/tools/ocaml/xenstored/logging.ml Tue Dec 13 16:08:08 2011 +0000
@@ -182,6 +182,7 @@ let string_of_access_type = function

| Xenbus.Xb.Op.Error -> "error "
| Xenbus.Xb.Op.Watchevent -> "w event "
+ | Xenbus.Xb.Op.Invalid -> "invalid "
(*
| x -> Xenbus.Xb.Op.to_string x
*)
diff -r 74ab4d0c8eba -r 06c6ba664164 tools/ocaml/xenstored/process.ml
--- a/tools/ocaml/xenstored/process.ml Tue Dec 13 16:07:40 2011 +0000
+++ b/tools/ocaml/xenstored/process.ml Tue Dec 13 16:08:08 2011 +0000
@@ -324,7 +324,8 @@ let function_of_type ty =
| Xenbus.Xb.Op.Resume -> reply_ack do_resume
| Xenbus.Xb.Op.Set_target -> reply_ack do_set_target
| Xenbus.Xb.Op.Restrict -> reply_ack do_restrict
- | _ -> reply_ack do_error
+ | Xenbus.Xb.Op.Invalid -> reply_ack do_error
+ | _ -> reply_ack do_error

let input_handle_error ~cons ~doms ~fct ~ty ~con ~t ~rid ~data =
let reply_error e =
diff -r 74ab4d0c8eba -r 06c6ba664164 tools/ocaml/xenstored/xenstored.ml
--- a/tools/ocaml/xenstored/xenstored.ml Tue Dec 13 16:07:40 2011 +0000
+++ b/tools/ocaml/xenstored/xenstored.ml Tue Dec 13 16:08:08 2011 +0000
@@ -43,9 +43,7 @@ let process_connection_fds store cons do
debug "closing socket connection"
in
let process_fdset_with fds fct =
- List.iter (fun fd ->
- try try_fct fct (Connections.find cons fd)
- with Not_found -> ()) fds
+ List.iter (fun fd -> try_fct fct (Connections.find cons fd)) fds
in
process_fdset_with rset Process.do_input;
process_fdset_with wset Process.do_output

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