On 2/15/19 9:10 AM, Nikolay Shirokovskiy wrote:
> Message of API call that creates stream and stream itself have
> same rpc serial. This can lead to issues. If stream got error
> immediately after creation then notification can be delivered
> before API call reply arrived. This is possible because the
> reply and the error message are sent from different threads
> (rpc worker thread and event loop thread respectively). As
> we don't check for message type in virNetClientCallCompleteAllWaitingReply
> we complete the API call which leads to API call error [1]
> as there is no actual reply. Later when reply arrives connection
> will be closed due to protocol error (see check in virNetClientCallDispatchReply).
> Let's fix virNetClientCallCompleteAllWaitingReply.
>
> Queue inspection on arriving VIR_NET_CONTINUE message in
> virNetClientCallDispatchStream is safe because there we check for
> status field also. Queue inspection on arriving VIR_NET_OK is safe
> too as this message can not arrive before we call virFinishAbort(Finish)
> which is not possible before API call that creates streams returns.
> But just to be sure let's add checking message type in these places too.
>
> [1] error: internal error: Unexpected message type 0
>
> Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy@xxxxxxxxxxxxx>
> ---
> src/rpc/virnetclient.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
The commit message was hard to read, but I know it's an english is not
the first language type thing.
> diff --git a/src/rpc/virnetclient.c b/src/rpc/virnetclient.c
> index 64855fb..0393587 100644
> --- a/src/rpc/virnetclient.c
> +++ b/src/rpc/virnetclient.c
> @@ -1163,7 +1163,8 @@ static void virNetClientCallCompleteAllWaitingReply(virNetClientPtr client)
> virNetClientCallPtr call;
>
> for (call = client->waitDispatch; call; call = call->next) {
> - if (call->msg->header.prog == client->msg.header.prog &&
> + if (call->msg->header.type == VIR_NET_STREAM &&
What about VIR_NET_STREAM_HOLE ?
Hopefully someone with greater working knowledge of the processing of
this code can help out here. I guess I'm just concerned about some odd
processing case that may have expected to be called, but now wouldn't be
because of this change.
BTW: any thoughts to perhaps extracting out the common parts between the
three places changed into it's own helper/method? e.g.:
thecall->msg->header.prog == client->msg.header.prog &&
thecall->msg->header.vers == client->msg.header.vers &&
thecall->msg->header.serial == client->msg.header.serial &&
thecall->expectReply
and then the follow-up patch to add the additional '.type' checks?
John
> + call->msg->header.prog == client->msg.header.prog &&
> call->msg->header.vers == client->msg.header.vers &&
> call->msg->header.serial == client->msg.header.serial &&
> call->expectReply)
> @@ -1207,7 +1208,8 @@ static int virNetClientCallDispatchStream(virNetClientPtr client)
>
> /* Find oldest dummy message waiting for incoming data. */
> for (thecall = client->waitDispatch; thecall; thecall = thecall->next) {
> - if (thecall->msg->header.prog == client->msg.header.prog &&
> + if (thecall->msg->header.type == VIR_NET_STREAM &&
> + thecall->msg->header.prog == client->msg.header.prog &&
> thecall->msg->header.vers == client->msg.header.vers &&
> thecall->msg->header.serial == client->msg.header.serial &&
> thecall->expectReply &&
> @@ -1225,7 +1227,8 @@ static int virNetClientCallDispatchStream(virNetClientPtr client)
> case VIR_NET_OK:
> /* Find oldest abort/finish message. */
> for (thecall = client->waitDispatch; thecall; thecall = thecall->next) {
> - if (thecall->msg->header.prog == client->msg.header.prog &&
> + if (thecall->msg->header.type == VIR_NET_STREAM &&
> + thecall->msg->header.prog == client->msg.header.prog &&
> thecall->msg->header.vers == client->msg.header.vers &&
> thecall->msg->header.serial == client->msg.header.serial &&
> thecall->expectReply &&
>
--
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