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-rw-r--r--pkg/sentry/fs/dev/BUILD5
-rw-r--r--pkg/sentry/fs/dev/dev.go10
-rw-r--r--pkg/sentry/fs/dev/net_tun.go170
3 files changed, 182 insertions, 3 deletions
diff --git a/pkg/sentry/fs/dev/BUILD b/pkg/sentry/fs/dev/BUILD
index 4c4b7d5cc..9b6bb26d0 100644
--- a/pkg/sentry/fs/dev/BUILD
+++ b/pkg/sentry/fs/dev/BUILD
@@ -9,6 +9,7 @@ go_library(
"device.go",
"fs.go",
"full.go",
+ "net_tun.go",
"null.go",
"random.go",
"tty.go",
@@ -19,15 +20,19 @@ go_library(
"//pkg/context",
"//pkg/rand",
"//pkg/safemem",
+ "//pkg/sentry/arch",
"//pkg/sentry/device",
"//pkg/sentry/fs",
"//pkg/sentry/fs/fsutil",
"//pkg/sentry/fs/ramfs",
"//pkg/sentry/fs/tmpfs",
+ "//pkg/sentry/kernel",
"//pkg/sentry/memmap",
"//pkg/sentry/mm",
"//pkg/sentry/pgalloc",
+ "//pkg/sentry/socket/netstack",
"//pkg/syserror",
+ "//pkg/tcpip/link/tun",
"//pkg/usermem",
"//pkg/waiter",
],
diff --git a/pkg/sentry/fs/dev/dev.go b/pkg/sentry/fs/dev/dev.go
index 35bd23991..7e66c29b0 100644
--- a/pkg/sentry/fs/dev/dev.go
+++ b/pkg/sentry/fs/dev/dev.go
@@ -66,8 +66,8 @@ func newMemDevice(ctx context.Context, iops fs.InodeOperations, msrc *fs.MountSo
})
}
-func newDirectory(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
- iops := ramfs.NewDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0555))
+func newDirectory(ctx context.Context, contents map[string]*fs.Inode, msrc *fs.MountSource) *fs.Inode {
+ iops := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555))
return fs.NewInode(ctx, iops, msrc, fs.StableAttr{
DeviceID: devDevice.DeviceID(),
InodeID: devDevice.NextIno(),
@@ -111,7 +111,7 @@ func New(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
// A devpts is typically mounted at /dev/pts to provide
// pseudoterminal support. Place an empty directory there for
// the devpts to be mounted over.
- "pts": newDirectory(ctx, msrc),
+ "pts": newDirectory(ctx, nil, msrc),
// Similarly, applications expect a ptmx device at /dev/ptmx
// connected to the terminals provided by /dev/pts/. Rather
// than creating a device directly (which requires a hairy
@@ -124,6 +124,10 @@ func New(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
"ptmx": newSymlink(ctx, "pts/ptmx", msrc),
"tty": newCharacterDevice(ctx, newTTYDevice(ctx, fs.RootOwner, 0666), msrc, ttyDevMajor, ttyDevMinor),
+
+ "net": newDirectory(ctx, map[string]*fs.Inode{
+ "tun": newCharacterDevice(ctx, newNetTunDevice(ctx, fs.RootOwner, 0666), msrc, netTunDevMajor, netTunDevMinor),
+ }, msrc),
}
iops := ramfs.NewDir(ctx, contents, fs.RootOwner, fs.FilePermsFromMode(0555))
diff --git a/pkg/sentry/fs/dev/net_tun.go b/pkg/sentry/fs/dev/net_tun.go
new file mode 100644
index 000000000..755644488
--- /dev/null
+++ b/pkg/sentry/fs/dev/net_tun.go
@@ -0,0 +1,170 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package dev
+
+import (
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/fs"
+ "gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/socket/netstack"
+ "gvisor.dev/gvisor/pkg/syserror"
+ "gvisor.dev/gvisor/pkg/tcpip/link/tun"
+ "gvisor.dev/gvisor/pkg/usermem"
+ "gvisor.dev/gvisor/pkg/waiter"
+)
+
+const (
+ netTunDevMajor = 10
+ netTunDevMinor = 200
+)
+
+// +stateify savable
+type netTunInodeOperations struct {
+ fsutil.InodeGenericChecker `state:"nosave"`
+ fsutil.InodeNoExtendedAttributes `state:"nosave"`
+ fsutil.InodeNoopAllocate `state:"nosave"`
+ fsutil.InodeNoopRelease `state:"nosave"`
+ fsutil.InodeNoopTruncate `state:"nosave"`
+ fsutil.InodeNoopWriteOut `state:"nosave"`
+ fsutil.InodeNotDirectory `state:"nosave"`
+ fsutil.InodeNotMappable `state:"nosave"`
+ fsutil.InodeNotSocket `state:"nosave"`
+ fsutil.InodeNotSymlink `state:"nosave"`
+ fsutil.InodeVirtual `state:"nosave"`
+
+ fsutil.InodeSimpleAttributes
+}
+
+var _ fs.InodeOperations = (*netTunInodeOperations)(nil)
+
+func newNetTunDevice(ctx context.Context, owner fs.FileOwner, mode linux.FileMode) *netTunInodeOperations {
+ return &netTunInodeOperations{
+ InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, owner, fs.FilePermsFromMode(mode), linux.TMPFS_MAGIC),
+ }
+}
+
+// GetFile implements fs.InodeOperations.GetFile.
+func (iops *netTunInodeOperations) GetFile(ctx context.Context, d *fs.Dirent, flags fs.FileFlags) (*fs.File, error) {
+ return fs.NewFile(ctx, d, flags, &netTunFileOperations{}), nil
+}
+
+// +stateify savable
+type netTunFileOperations struct {
+ fsutil.FileNoSeek `state:"nosave"`
+ fsutil.FileNoMMap `state:"nosave"`
+ fsutil.FileNoSplice `state:"nosave"`
+ fsutil.FileNoopFlush `state:"nosave"`
+ fsutil.FileNoopFsync `state:"nosave"`
+ fsutil.FileNotDirReaddir `state:"nosave"`
+ fsutil.FileUseInodeUnstableAttr `state:"nosave"`
+
+ device tun.Device
+}
+
+var _ fs.FileOperations = (*netTunFileOperations)(nil)
+
+// Release implements fs.FileOperations.Release.
+func (fops *netTunFileOperations) Release() {
+ fops.device.Release()
+}
+
+// Ioctl implements fs.FileOperations.Ioctl.
+func (fops *netTunFileOperations) Ioctl(ctx context.Context, file *fs.File, io usermem.IO, args arch.SyscallArguments) (uintptr, error) {
+ request := args[1].Uint()
+ data := args[2].Pointer()
+
+ switch request {
+ case linux.TUNSETIFF:
+ t := kernel.TaskFromContext(ctx)
+ if t == nil {
+ panic("Ioctl should be called from a task context")
+ }
+ if !t.HasCapability(linux.CAP_NET_ADMIN) {
+ return 0, syserror.EPERM
+ }
+ stack, ok := t.NetworkContext().(*netstack.Stack)
+ if !ok {
+ return 0, syserror.EINVAL
+ }
+
+ var req linux.IFReq
+ if _, err := usermem.CopyObjectIn(ctx, io, data, &req, usermem.IOOpts{
+ AddressSpaceActive: true,
+ }); err != nil {
+ return 0, err
+ }
+ flags := usermem.ByteOrder.Uint16(req.Data[:])
+ return 0, fops.device.SetIff(stack.Stack, req.Name(), flags)
+
+ case linux.TUNGETIFF:
+ var req linux.IFReq
+
+ copy(req.IFName[:], fops.device.Name())
+
+ // Linux adds IFF_NOFILTER (the same value as IFF_NO_PI unfortunately) when
+ // there is no sk_filter. See __tun_chr_ioctl() in net/drivers/tun.c.
+ flags := fops.device.Flags() | linux.IFF_NOFILTER
+ usermem.ByteOrder.PutUint16(req.Data[:], flags)
+
+ _, err := usermem.CopyObjectOut(ctx, io, data, &req, usermem.IOOpts{
+ AddressSpaceActive: true,
+ })
+ return 0, err
+
+ default:
+ return 0, syserror.ENOTTY
+ }
+}
+
+// Write implements fs.FileOperations.Write.
+func (fops *netTunFileOperations) Write(ctx context.Context, file *fs.File, src usermem.IOSequence, offset int64) (int64, error) {
+ data := make([]byte, src.NumBytes())
+ if _, err := src.CopyIn(ctx, data); err != nil {
+ return 0, err
+ }
+ return fops.device.Write(data)
+}
+
+// Read implements fs.FileOperations.Read.
+func (fops *netTunFileOperations) Read(ctx context.Context, file *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
+ data, err := fops.device.Read()
+ if err != nil {
+ return 0, err
+ }
+ n, err := dst.CopyOut(ctx, data)
+ if n > 0 && n < len(data) {
+ // Not an error for partial copying. Packet truncated.
+ err = nil
+ }
+ return int64(n), err
+}
+
+// Readiness implements watier.Waitable.Readiness.
+func (fops *netTunFileOperations) Readiness(mask waiter.EventMask) waiter.EventMask {
+ return fops.device.Readiness(mask)
+}
+
+// EventRegister implements watier.Waitable.EventRegister.
+func (fops *netTunFileOperations) EventRegister(e *waiter.Entry, mask waiter.EventMask) {
+ fops.device.EventRegister(e, mask)
+}
+
+// EventUnregister implements watier.Waitable.EventUnregister.
+func (fops *netTunFileOperations) EventUnregister(e *waiter.Entry) {
+ fops.device.EventUnregister(e)
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 00:51:08 +0000