From 90ae7206f3ac989c6bc435c03badadcd25976eef Mon Sep 17 00:00:00 2001
From: Harald Hoyer <harald@redhat.com>
Date: Wed, 29 May 2019 17:04:14 +0200
Subject: [PATCH] Fix the varlink upgraded calls

Although an upgraded call is requested, the server has to send at least
one reply (can be an error) and the client has to check the reply,
before assuming an upgraded connection.

Signed-off-by: Harald Hoyer <harald@redhat.com>
---
 pkg/adapter/containers_remote.go | 10 +++++++++-
 pkg/varlinkapi/attach.go         |  5 ++++-
 pkg/varlinkapi/transfers.go      | 11 +++++++++--
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/pkg/adapter/containers_remote.go b/pkg/adapter/containers_remote.go
index c34495b3d9..0c0bce813c 100644
--- a/pkg/adapter/containers_remote.go
+++ b/pkg/adapter/containers_remote.go
@@ -583,7 +583,15 @@ func (r *LocalRuntime) attach(ctx context.Context, stdin, stdout *os.File, cid s
 
 	}
 	// TODO add detach keys support
-	_, err = iopodman.Attach().Send(r.Conn, varlink.Upgrade, cid, detachKeys, start)
+	reply, err := iopodman.Attach().Send(r.Conn, varlink.Upgrade, cid, detachKeys, start)
+	if err != nil {
+		restoreTerminal(oldTermState)
+		return nil, err
+	}
+
+	// See if the server accepts the upgraded connection or returns an error
+	_, err = reply()
+
 	if err != nil {
 		restoreTerminal(oldTermState)
 		return nil, err
diff --git a/pkg/varlinkapi/attach.go b/pkg/varlinkapi/attach.go
index 2234899a5a..8051f07be5 100644
--- a/pkg/varlinkapi/attach.go
+++ b/pkg/varlinkapi/attach.go
@@ -60,7 +60,10 @@ func (i *LibpodAPI) Attach(call iopodman.VarlinkCall, name string, detachKeys st
 	if !start && state != libpod.ContainerStateRunning {
 		return call.ReplyErrorOccurred("container must be running to attach")
 	}
-	call.Reply(nil)
+
+	// ACK the client upgrade request
+	call.ReplyAttach()
+
 	reader, writer, _, pw, streams := setupStreams(call)
 
 	go func() {
diff --git a/pkg/varlinkapi/transfers.go b/pkg/varlinkapi/transfers.go
index 96f76bcdcb..24a91a86fb 100644
--- a/pkg/varlinkapi/transfers.go
+++ b/pkg/varlinkapi/transfers.go
@@ -29,6 +29,12 @@ func (i *LibpodAPI) SendFile(call iopodman.VarlinkCall, ftype string, length int
 		return call.ReplyErrorOccurred(err.Error())
 	}
 
+	// FIXME return parameter
+	if err = call.ReplySendFile("FIXME_file_handle"); err != nil {
+		// If an error occurs while sending the reply, return the error
+		return err
+	}
+
 	writer := bufio.NewWriter(outputFile)
 	defer writer.Flush()
 
@@ -60,9 +66,10 @@ func (i *LibpodAPI) ReceiveFile(call iopodman.VarlinkCall, filepath string, dele
 	}
 
 	// Send the file length down to client
-	// Varlink connection upraded
+	// Varlink connection upgraded
 	if err = call.ReplyReceiveFile(fileInfo.Size()); err != nil {
-		return call.ReplyErrorOccurred(err.Error())
+		// If an error occurs while sending the reply, return the error
+		return err
 	}
 
 	reader := bufio.NewReader(fs)