Merge pull request #2285 from teawater/update_a

vendor: Update github.com/kata-containers/agent

Gopkg.lock

@@ -405,7 +405,7 @@
   revision = "8cba5a8e5f2816f26f9dc34b8ea968279a5a76eb"
 
 [[projects]]
-  digest = "1:903bfb87f41dc18a533d327b5b03fd2f562f34deafcbd0db93d4be3fa8d6099c"
+  digest = "1:6da9487ef0cc0cca3eeb1a24e3bb018ce2e07b7c2fc4d50975b54efdcc942118"
   name = "github.com/kata-containers/agent"
   packages = [
     "pkg/types",
@@ -413,7 +413,7 @@
     "protocols/grpc",
   ]
   pruneopts = "NUT"
-  revision = "32c87e75c2e4c014961f104c3c59b87f2aee3384"
+  revision = "6182fa34c64ba6eb1b6028d8b6647a86844129c4"
 
 [[projects]]
   branch = "master"

Gopkg.toml

@@ -52,7 +52,7 @@
 
 [[constraint]]
   name = "github.com/kata-containers/agent"
-  revision = "32c87e75c2e4c014961f104c3c59b87f2aee3384"
+  revision = "6182fa34c64ba6eb1b6028d8b6647a86844129c4"
 
 [[constraint]]
   name = "github.com/containerd/cri-containerd"

vendor/github.com/kata-containers/agent/protocols/client/client.go

@@ -9,16 +9,19 @@ package client
 import (
 	"context"
 	"fmt"
+	"io"
 	"net"
 	"net/url"
 	"strconv"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc"
 	"github.com/hashicorp/yamux"
 	"github.com/mdlayher/vsock"
 	opentracing "github.com/opentracing/opentracing-go"
+	"golang.org/x/sys/unix"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	grpcStatus "google.golang.org/grpc/status"
@@ -407,12 +410,24 @@ func HybridVSockDialer(sock string, timeout time.Duration) (net.Conn, error) {
 			return nil, err
 		}
 
-		// Read EOT (End of transmission) byte
-		eot := make([]byte, 32)
-		if _, err = conn.Read(eot); err != nil {
-			// Just close the connection, gRPC will dial again
-			// without errors
-			conn.Close()
+		// Receive the packet from the connection without removing it from
+		// the receive queue (MSG_PEEK), ensuring the connection is usable.
+		if uc, ok := conn.(*net.UnixConn); ok {
+			file, err := uc.File()
+			if err != nil {
+				conn.Close()
+				return nil, err
+			}
+			eot := make([]byte, 1)
+			n, _, err := unix.Recvfrom(int(file.Fd()), eot, syscall.MSG_PEEK)
+			file.Close()
+			if err != nil || n == 0 {
+				conn.Close()
+				if err == nil {
+					err = io.EOF
+				}
+				return nil, err
+			}
 		}
 
 		return conn, nil