From ea06836d6cf1a723b862f61a75439b1bc6dafaa1 Mon Sep 17 00:00:00 2001
From: Saied Kazemi <saied@google.com>
Date: Tue, 9 Feb 2016 22:00:37 -0800
Subject: [PATCH] Restore network connectivity after container restore

This is a work-in-progress implementation of restoring network connectivty
after container restore.  Its main purpose is for testing and starting
a conversation for a production-quality implementation.

Signed-off-by: Saied Kazemi <saied@google.com>
---
 daemon/daemon.go                                    |  3 +++
 daemon/execdriver/driver.go                         |  1 +
 daemon/execdriver/native/driver.go                  | 13 +++++++++++++
 .../github.com/vishvananda/netlink/link_linux.go    | 12 ++++++++++++
 4 files changed, 29 insertions(+)

diff --git a/daemon/daemon.go b/daemon/daemon.go
index 38e90cfe8289d..e3cb0eff8b108 100644
--- a/daemon/daemon.go
+++ b/daemon/daemon.go
@@ -1028,6 +1028,9 @@ func (daemon *Daemon) Checkpoint(c *container.Container, opts *types.CriuConfig)
 func (daemon *Daemon) Restore(c *container.Container, pipes *execdriver.Pipes, restoreCallback execdriver.DriverCallback, opts *types.CriuConfig, forceRestore bool) (execdriver.ExitStatus, error) {
 	hooks := execdriver.Hooks{
 		Restore: restoreCallback,
+		PostRestore: func(processConfig *execdriver.ProcessConfig, pid int, chOOM <-chan struct{}) error {
+			return daemon.setNetworkNamespaceKey(c.ID, pid)
+		},
 	}
 
 	exitCode, err := daemon.execDriver.Restore(c.Command, pipes, hooks, opts, forceRestore)
diff --git a/daemon/execdriver/driver.go b/daemon/execdriver/driver.go
index 374de6daebc98..f29467098e078 100644
--- a/daemon/execdriver/driver.go
+++ b/daemon/execdriver/driver.go
@@ -40,6 +40,7 @@ type Hooks struct {
 	PostStop []DriverCallback
 	// Restore is called after the container is restored
 	Restore DriverCallback
+	PostRestore DriverCallback
 }
 
 // Info is driver specific information based on
diff --git a/daemon/execdriver/native/driver.go b/daemon/execdriver/native/driver.go
index e62c67458f87f..1e1bf11001fc9 100644
--- a/daemon/execdriver/native/driver.go
+++ b/daemon/execdriver/native/driver.go
@@ -393,7 +393,20 @@ func (d *Driver) Restore(c *execdriver.Command, pipes *execdriver.Pipes, hooks e
 		return execdriver.ExitStatus{ExitCode: -1}, err
 	}
 
+	if err := d.createNetwork(&config, c, hooks); err != nil {
+		return execdriver.ExitStatus{ExitCode: -1}, err
+	}
+
 	oom := notifyOnOOM(cont)
+	if hooks.PostRestore != nil {
+		pid, err := p.Pid()
+		if err != nil {
+			p.Signal(os.Kill)
+			p.Wait()
+			return execdriver.ExitStatus{ExitCode: -1}, err
+		}
+		hooks.PostRestore(&c.ProcessConfig, pid, oom)
+	}
 	if hooks.Restore != nil {
 		pid, err := p.Pid()
 		if err != nil {
diff --git a/vendor/src/github.com/vishvananda/netlink/link_linux.go b/vendor/src/github.com/vishvananda/netlink/link_linux.go
index 08262857f19c1..94e9fefca0318 100644
--- a/vendor/src/github.com/vishvananda/netlink/link_linux.go
+++ b/vendor/src/github.com/vishvananda/netlink/link_linux.go
@@ -103,6 +103,18 @@ func LinkSetName(link Link, name string) error {
 	req.AddData(data)
 
 	_, err := req.Execute(syscall.NETLINK_ROUTE, 0)
+	if err != nil && os.IsExist(err) && name == "eth0" {
+		// XXX Temporary hack.
+		//     If we are called after a container has been restored,
+		//     we need to delete eth0 and try again.
+		//     The right solution is to tell CRIU not create network
+		//     devices.
+		l := &Device{LinkAttrs: LinkAttrs{Name: name}}
+		if e := LinkDel(l); e != nil {
+			return e
+		}
+		_, err = req.Execute(syscall.NETLINK_ROUTE, 0)
+	}
 	return err
 }