7 files changed, 32 insertions, 1 deletions
diff --git a/pkg/sentry/devices/memdev/full.go b/pkg/sentry/devices/memdev/full.go
index 511179e31..fece3e762 100644
--- a/pkg/sentry/devices/memdev/full.go
+++ b/pkg/sentry/devices/memdev/full.go
@@ -24,6 +24,8 @@ import (
 const fullDevMinor = 7
 
 // fullDevice implements vfs.Device for /dev/full.
+//
+// +stateify savable
 type fullDevice struct{}
 
 // Open implements vfs.Device.Open.
@@ -38,6 +40,8 @@ func (fullDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, op
 }
 
 // fullFD implements vfs.FileDescriptionImpl for /dev/full.
+//
+// +stateify savable
 type fullFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
diff --git a/pkg/sentry/devices/memdev/null.go b/pkg/sentry/devices/memdev/null.go
index 4918dbeeb..ff5837747 100644
--- a/pkg/sentry/devices/memdev/null.go
+++ b/pkg/sentry/devices/memdev/null.go
@@ -25,6 +25,8 @@ import (
 const nullDevMinor = 3
 
 // nullDevice implements vfs.Device for /dev/null.
+//
+// +stateify savable
 type nullDevice struct{}
 
 // Open implements vfs.Device.Open.
@@ -39,6 +41,8 @@ func (nullDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, op
 }
 
 // nullFD implements vfs.FileDescriptionImpl for /dev/null.
+//
+// +stateify savable
 type nullFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
diff --git a/pkg/sentry/devices/memdev/random.go b/pkg/sentry/devices/memdev/random.go
index 5e7fe0280..ac943e3ba 100644
--- a/pkg/sentry/devices/memdev/random.go
+++ b/pkg/sentry/devices/memdev/random.go
@@ -30,6 +30,8 @@ const (
 )
 
 // randomDevice implements vfs.Device for /dev/random and /dev/urandom.
+//
+// +stateify savable
 type randomDevice struct{}
 
 // Open implements vfs.Device.Open.
@@ -44,6 +46,8 @@ func (randomDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry,
 }
 
 // randomFD implements vfs.FileDescriptionImpl for /dev/random.
+//
+// +stateify savable
 type randomFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
diff --git a/pkg/sentry/devices/memdev/zero.go b/pkg/sentry/devices/memdev/zero.go
index 60cfea888..1929e41cd 100644
--- a/pkg/sentry/devices/memdev/zero.go
+++ b/pkg/sentry/devices/memdev/zero.go
@@ -27,6 +27,8 @@ import (
 const zeroDevMinor = 5
 
 // zeroDevice implements vfs.Device for /dev/zero.
+//
+// +stateify savable
 type zeroDevice struct{}
 
 // Open implements vfs.Device.Open.
@@ -41,6 +43,8 @@ func (zeroDevice) Open(ctx context.Context, mnt *vfs.Mount, vfsd *vfs.Dentry, op
 }
 
 // zeroFD implements vfs.FileDescriptionImpl for /dev/zero.
+//
+// +stateify savable
 type zeroFD struct {
 	vfsfd vfs.FileDescription
 	vfs.FileDescriptionDefaultImpl
diff --git a/pkg/sentry/devices/ttydev/ttydev.go b/pkg/sentry/devices/ttydev/ttydev.go
index 664e54498..a287c65ca 100644
--- a/pkg/sentry/devices/ttydev/ttydev.go
+++ b/pkg/sentry/devices/ttydev/ttydev.go
@@ -30,6 +30,8 @@ const (
 )
 
 // ttyDevice implements vfs.Device for /dev/tty.
+//
+// +stateify savable
 type ttyDevice struct{}
 
 // Open implements vfs.Device.Open.
diff --git a/pkg/sentry/devices/tundev/BUILD b/pkg/sentry/devices/tundev/BUILD
index 71c59287c..14a8bf9cd 100644
--- a/pkg/sentry/devices/tundev/BUILD
+++ b/pkg/sentry/devices/tundev/BUILD
@@ -17,6 +17,7 @@ go_library(
         "//pkg/sentry/vfs",
         "//pkg/syserror",
         "//pkg/tcpip/link/tun",
+        "//pkg/tcpip/network/arp",
         "//pkg/usermem",
         "//pkg/waiter",
     ],
diff --git a/pkg/sentry/devices/tundev/tundev.go b/pkg/sentry/devices/tundev/tundev.go
index 0b701a289..655ea549b 100644
--- a/pkg/sentry/devices/tundev/tundev.go
+++ b/pkg/sentry/devices/tundev/tundev.go
@@ -16,6 +16,8 @@
 package tundev
 
 import (
+	"fmt"
+
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
@@ -26,6 +28,7 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/tcpip/link/tun"
+	"gvisor.dev/gvisor/pkg/tcpip/network/arp"
 	"gvisor.dev/gvisor/pkg/usermem"
 	"gvisor.dev/gvisor/pkg/waiter"
 )
@@ -84,7 +87,16 @@ func (fd *tunFD) Ioctl(ctx context.Context, uio usermem.IO, args arch.SyscallArg
 			return 0, err
 		}
 		flags := usermem.ByteOrder.Uint16(req.Data[:])
-		return 0, fd.device.SetIff(stack.Stack, req.Name(), flags)
+		created, err := fd.device.SetIff(stack.Stack, req.Name(), flags)
+		if err == nil && created {
+			// Always start with an ARP address for interfaces so they can handle ARP
+			// packets.
+			nicID := fd.device.NICID()
+			if err := stack.Stack.AddAddress(nicID, arp.ProtocolNumber, arp.ProtocolAddress); err != nil {
+				panic(fmt.Sprintf("failed to add ARP address after creating new TUN/TAP interface with ID = %d", nicID))
+			}
+		}
+		return 0, err
 
 	case linux.TUNGETIFF:
 		var req linux.IFReq