From 0e2f1b7abd219f39d67cc2cecd00c441a13eeb29 Mon Sep 17 00:00:00 2001 From: Adin Scannell Date: Mon, 27 Jan 2020 15:17:58 -0800 Subject: Update package locations. Because the abi will depend on the core types for marshalling (usermem, context, safemem, safecopy), these need to be flattened from the sentry directory. These packages contain no sentry-specific details. PiperOrigin-RevId: 291811289 --- pkg/sentry/fs/dev/dev.go | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'pkg/sentry/fs/dev/dev.go') diff --git a/pkg/sentry/fs/dev/dev.go b/pkg/sentry/fs/dev/dev.go index f739c476c..35bd23991 100644 --- a/pkg/sentry/fs/dev/dev.go +++ b/pkg/sentry/fs/dev/dev.go @@ -18,11 +18,11 @@ package dev import ( "math" - "gvisor.dev/gvisor/pkg/sentry/context" + "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/ramfs" "gvisor.dev/gvisor/pkg/sentry/fs/tmpfs" - "gvisor.dev/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/usermem" ) // Memory device numbers are from Linux's drivers/char/mem.c -- cgit v1.2.3 From b8f56c79be40d9c75f4e2f279c9d821d1c1c3569 Mon Sep 17 00:00:00 2001 From: Ting-Yu Wang Date: Fri, 21 Feb 2020 15:41:56 -0800 Subject: Implement tap/tun device in vfs. PiperOrigin-RevId: 296526279 --- pkg/abi/linux/BUILD | 1 + pkg/abi/linux/ioctl.go | 26 ++ pkg/abi/linux/ioctl_tun.go | 29 ++ pkg/sentry/fs/dev/BUILD | 5 + pkg/sentry/fs/dev/dev.go | 10 +- pkg/sentry/fs/dev/net_tun.go | 170 +++++++++++ pkg/syserror/syserror.go | 1 + pkg/tcpip/buffer/view.go | 6 + pkg/tcpip/link/channel/BUILD | 1 + pkg/tcpip/link/channel/channel.go | 180 +++++++++--- pkg/tcpip/link/tun/BUILD | 18 +- pkg/tcpip/link/tun/device.go | 352 +++++++++++++++++++++++ pkg/tcpip/link/tun/protocol.go | 56 ++++ pkg/tcpip/stack/nic.go | 32 +++ pkg/tcpip/stack/stack.go | 39 +++ test/syscalls/BUILD | 2 + test/syscalls/linux/BUILD | 30 ++ test/syscalls/linux/dev.cc | 7 + test/syscalls/linux/socket_netlink_route_util.cc | 163 +++++++++++ test/syscalls/linux/socket_netlink_route_util.h | 55 ++++ test/syscalls/linux/tuntap.cc | 346 ++++++++++++++++++++++ 21 files changed, 1490 insertions(+), 39 deletions(-) create mode 100644 pkg/abi/linux/ioctl_tun.go create mode 100644 pkg/sentry/fs/dev/net_tun.go create mode 100644 pkg/tcpip/link/tun/device.go create mode 100644 pkg/tcpip/link/tun/protocol.go create mode 100644 test/syscalls/linux/socket_netlink_route_util.cc create mode 100644 test/syscalls/linux/socket_netlink_route_util.h create mode 100644 test/syscalls/linux/tuntap.cc (limited to 'pkg/sentry/fs/dev/dev.go') diff --git a/pkg/abi/linux/BUILD b/pkg/abi/linux/BUILD index a89f34d4b..322d1ccc4 100644 --- a/pkg/abi/linux/BUILD +++ b/pkg/abi/linux/BUILD @@ -30,6 +30,7 @@ go_library( "futex.go", "inotify.go", "ioctl.go", + "ioctl_tun.go", "ip.go", "ipc.go", "limits.go", diff --git a/pkg/abi/linux/ioctl.go b/pkg/abi/linux/ioctl.go index 0e18db9ef..2062e6a4b 100644 --- a/pkg/abi/linux/ioctl.go +++ b/pkg/abi/linux/ioctl.go @@ -72,3 +72,29 @@ const ( SIOCGMIIPHY = 0x8947 SIOCGMIIREG = 0x8948 ) + +// ioctl(2) directions. Used to calculate requests number. +// Constants from asm-generic/ioctl.h. +const ( + _IOC_NONE = 0 + _IOC_WRITE = 1 + _IOC_READ = 2 +) + +// Constants from asm-generic/ioctl.h. +const ( + _IOC_NRBITS = 8 + _IOC_TYPEBITS = 8 + _IOC_SIZEBITS = 14 + _IOC_DIRBITS = 2 + + _IOC_NRSHIFT = 0 + _IOC_TYPESHIFT = _IOC_NRSHIFT + _IOC_NRBITS + _IOC_SIZESHIFT = _IOC_TYPESHIFT + _IOC_TYPEBITS + _IOC_DIRSHIFT = _IOC_SIZESHIFT + _IOC_SIZEBITS +) + +// IOC outputs the result of _IOC macro in asm-generic/ioctl.h. +func IOC(dir, typ, nr, size uint32) uint32 { + return uint32(dir)<<_IOC_DIRSHIFT | typ<<_IOC_TYPESHIFT | nr<<_IOC_NRSHIFT | size<<_IOC_SIZESHIFT +} diff --git a/pkg/abi/linux/ioctl_tun.go b/pkg/abi/linux/ioctl_tun.go new file mode 100644 index 000000000..c59c9c136 --- /dev/null +++ b/pkg/abi/linux/ioctl_tun.go @@ -0,0 +1,29 @@ +// 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 linux + +// ioctl(2) request numbers from linux/if_tun.h +var ( + TUNSETIFF = IOC(_IOC_WRITE, 'T', 202, 4) + TUNGETIFF = IOC(_IOC_READ, 'T', 210, 4) +) + +// Flags from net/if_tun.h +const ( + IFF_TUN = 0x0001 + IFF_TAP = 0x0002 + IFF_NO_PI = 0x1000 + IFF_NOFILTER = 0x1000 +) 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) +} diff --git a/pkg/syserror/syserror.go b/pkg/syserror/syserror.go index 2269f6237..4b5a0fca6 100644 --- a/pkg/syserror/syserror.go +++ b/pkg/syserror/syserror.go @@ -29,6 +29,7 @@ var ( EACCES = error(syscall.EACCES) EAGAIN = error(syscall.EAGAIN) EBADF = error(syscall.EBADF) + EBADFD = error(syscall.EBADFD) EBUSY = error(syscall.EBUSY) ECHILD = error(syscall.ECHILD) ECONNREFUSED = error(syscall.ECONNREFUSED) diff --git a/pkg/tcpip/buffer/view.go b/pkg/tcpip/buffer/view.go index 150310c11..17e94c562 100644 --- a/pkg/tcpip/buffer/view.go +++ b/pkg/tcpip/buffer/view.go @@ -156,3 +156,9 @@ func (vv *VectorisedView) Append(vv2 VectorisedView) { vv.views = append(vv.views, vv2.views...) vv.size += vv2.size } + +// AppendView appends the given view into this vectorised view. +func (vv *VectorisedView) AppendView(v View) { + vv.views = append(vv.views, v) + vv.size += len(v) +} diff --git a/pkg/tcpip/link/channel/BUILD b/pkg/tcpip/link/channel/BUILD index 3974c464e..b8b93e78e 100644 --- a/pkg/tcpip/link/channel/BUILD +++ b/pkg/tcpip/link/channel/BUILD @@ -7,6 +7,7 @@ go_library( srcs = ["channel.go"], visibility = ["//visibility:public"], deps = [ + "//pkg/sync", "//pkg/tcpip", "//pkg/tcpip/buffer", "//pkg/tcpip/stack", diff --git a/pkg/tcpip/link/channel/channel.go b/pkg/tcpip/link/channel/channel.go index 78d447acd..5944ba190 100644 --- a/pkg/tcpip/link/channel/channel.go +++ b/pkg/tcpip/link/channel/channel.go @@ -20,6 +20,7 @@ package channel import ( "context" + "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" "gvisor.dev/gvisor/pkg/tcpip/stack" @@ -33,6 +34,118 @@ type PacketInfo struct { Route stack.Route } +// Notification is the interface for receiving notification from the packet +// queue. +type Notification interface { + // WriteNotify will be called when a write happens to the queue. + WriteNotify() +} + +// NotificationHandle is an opaque handle to the registered notification target. +// It can be used to unregister the notification when no longer interested. +// +// +stateify savable +type NotificationHandle struct { + n Notification +} + +type queue struct { + // mu protects fields below. + mu sync.RWMutex + // c is the outbound packet channel. Sending to c should hold mu. + c chan PacketInfo + numWrite int + numRead int + notify []*NotificationHandle +} + +func (q *queue) Close() { + close(q.c) +} + +func (q *queue) Read() (PacketInfo, bool) { + q.mu.Lock() + defer q.mu.Unlock() + select { + case p := <-q.c: + q.numRead++ + return p, true + default: + return PacketInfo{}, false + } +} + +func (q *queue) ReadContext(ctx context.Context) (PacketInfo, bool) { + // We have to receive from channel without holding the lock, since it can + // block indefinitely. This will cause a window that numWrite - numRead + // produces a larger number, but won't go to negative. numWrite >= numRead + // still holds. + select { + case pkt := <-q.c: + q.mu.Lock() + defer q.mu.Unlock() + q.numRead++ + return pkt, true + case <-ctx.Done(): + return PacketInfo{}, false + } +} + +func (q *queue) Write(p PacketInfo) bool { + wrote := false + + // It's important to make sure nobody can see numWrite until we increment it, + // so numWrite >= numRead holds. + q.mu.Lock() + select { + case q.c <- p: + wrote = true + q.numWrite++ + default: + } + notify := q.notify + q.mu.Unlock() + + if wrote { + // Send notification outside of lock. + for _, h := range notify { + h.n.WriteNotify() + } + } + return wrote +} + +func (q *queue) Num() int { + q.mu.RLock() + defer q.mu.RUnlock() + n := q.numWrite - q.numRead + if n < 0 { + panic("numWrite < numRead") + } + return n +} + +func (q *queue) AddNotify(notify Notification) *NotificationHandle { + q.mu.Lock() + defer q.mu.Unlock() + h := &NotificationHandle{n: notify} + q.notify = append(q.notify, h) + return h +} + +func (q *queue) RemoveNotify(handle *NotificationHandle) { + q.mu.Lock() + defer q.mu.Unlock() + // Make a copy, since we reads the array outside of lock when notifying. + notify := make([]*NotificationHandle, 0, len(q.notify)) + for _, h := range q.notify { + if h != handle { + notify = append(notify, h) + } + } + q.notify = notify +} + // Endpoint is link layer endpoint that stores outbound packets in a channel // and allows injection of inbound packets. type Endpoint struct { @@ -41,14 +154,16 @@ type Endpoint struct { linkAddr tcpip.LinkAddress LinkEPCapabilities stack.LinkEndpointCapabilities - // c is where outbound packets are queued. - c chan PacketInfo + // Outbound packet queue. + q *queue } // New creates a new channel endpoint. func New(size int, mtu uint32, linkAddr tcpip.LinkAddress) *Endpoint { return &Endpoint{ - c: make(chan PacketInfo, size), + q: &queue{ + c: make(chan PacketInfo, size), + }, mtu: mtu, linkAddr: linkAddr, } @@ -57,43 +172,36 @@ func New(size int, mtu uint32, linkAddr tcpip.LinkAddress) *Endpoint { // Close closes e. Further packet injections will panic. Reads continue to // succeed until all packets are read. func (e *Endpoint) Close() { - close(e.c) + e.q.Close() } -// Read does non-blocking read for one packet from the outbound packet queue. +// Read does non-blocking read one packet from the outbound packet queue. func (e *Endpoint) Read() (PacketInfo, bool) { - select { - case pkt := <-e.c: - return pkt, true - default: - return PacketInfo{}, false - } + return e.q.Read() } // ReadContext does blocking read for one packet from the outbound packet queue. // It can be cancelled by ctx, and in this case, it returns false. func (e *Endpoint) ReadContext(ctx context.Context) (PacketInfo, bool) { - select { - case pkt := <-e.c: - return pkt, true - case <-ctx.Done(): - return PacketInfo{}, false - } + return e.q.ReadContext(ctx) } // Drain removes all outbound packets from the channel and counts them. func (e *Endpoint) Drain() int { c := 0 for { - select { - case <-e.c: - c++ - default: + if _, ok := e.Read(); !ok { return c } + c++ } } +// NumQueued returns the number of packet queued for outbound. +func (e *Endpoint) NumQueued() int { + return e.q.Num() +} + // InjectInbound injects an inbound packet. func (e *Endpoint) InjectInbound(protocol tcpip.NetworkProtocolNumber, pkt tcpip.PacketBuffer) { e.InjectLinkAddr(protocol, "", pkt) @@ -155,10 +263,7 @@ func (e *Endpoint) WritePacket(r *stack.Route, gso *stack.GSO, protocol tcpip.Ne Route: route, } - select { - case e.c <- p: - default: - } + e.q.Write(p) return nil } @@ -171,7 +276,6 @@ func (e *Endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts []tcpip.Pac route.Release() payloadView := pkts[0].Data.ToView() n := 0 -packetLoop: for _, pkt := range pkts { off := pkt.DataOffset size := pkt.DataSize @@ -185,12 +289,10 @@ packetLoop: Route: route, } - select { - case e.c <- p: - n++ - default: - break packetLoop + if !e.q.Write(p) { + break } + n++ } return n, nil @@ -204,13 +306,21 @@ func (e *Endpoint) WriteRawPacket(vv buffer.VectorisedView) *tcpip.Error { GSO: nil, } - select { - case e.c <- p: - default: - } + e.q.Write(p) return nil } // Wait implements stack.LinkEndpoint.Wait. func (*Endpoint) Wait() {} + +// AddNotify adds a notification target for receiving event about outgoing +// packets. +func (e *Endpoint) AddNotify(notify Notification) *NotificationHandle { + return e.q.AddNotify(notify) +} + +// RemoveNotify removes handle from the list of notification targets. +func (e *Endpoint) RemoveNotify(handle *NotificationHandle) { + e.q.RemoveNotify(handle) +} diff --git a/pkg/tcpip/link/tun/BUILD b/pkg/tcpip/link/tun/BUILD index e5096ea38..e0db6cf54 100644 --- a/pkg/tcpip/link/tun/BUILD +++ b/pkg/tcpip/link/tun/BUILD @@ -4,6 +4,22 @@ package(licenses = ["notice"]) go_library( name = "tun", - srcs = ["tun_unsafe.go"], + srcs = [ + "device.go", + "protocol.go", + "tun_unsafe.go", + ], visibility = ["//visibility:public"], + deps = [ + "//pkg/abi/linux", + "//pkg/refs", + "//pkg/sync", + "//pkg/syserror", + "//pkg/tcpip", + "//pkg/tcpip/buffer", + "//pkg/tcpip/header", + "//pkg/tcpip/link/channel", + "//pkg/tcpip/stack", + "//pkg/waiter", + ], ) diff --git a/pkg/tcpip/link/tun/device.go b/pkg/tcpip/link/tun/device.go new file mode 100644 index 000000000..6ff47a742 --- /dev/null +++ b/pkg/tcpip/link/tun/device.go @@ -0,0 +1,352 @@ +// 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 tun + +import ( + "fmt" + + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/refs" + "gvisor.dev/gvisor/pkg/sync" + "gvisor.dev/gvisor/pkg/syserror" + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/buffer" + "gvisor.dev/gvisor/pkg/tcpip/header" + "gvisor.dev/gvisor/pkg/tcpip/link/channel" + "gvisor.dev/gvisor/pkg/tcpip/stack" + "gvisor.dev/gvisor/pkg/waiter" +) + +const ( + // drivers/net/tun.c:tun_net_init() + defaultDevMtu = 1500 + + // Queue length for outbound packet, arriving at fd side for read. Overflow + // causes packet drops. gVisor implementation-specific. + defaultDevOutQueueLen = 1024 +) + +var zeroMAC [6]byte + +// Device is an opened /dev/net/tun device. +// +// +stateify savable +type Device struct { + waiter.Queue + + mu sync.RWMutex `state:"nosave"` + endpoint *tunEndpoint + notifyHandle *channel.NotificationHandle + flags uint16 +} + +// beforeSave is invoked by stateify. +func (d *Device) beforeSave() { + d.mu.Lock() + defer d.mu.Unlock() + // TODO(b/110961832): Restore the device to stack. At this moment, the stack + // is not savable. + if d.endpoint != nil { + panic("/dev/net/tun does not support save/restore when a device is associated with it.") + } +} + +// Release implements fs.FileOperations.Release. +func (d *Device) Release() { + d.mu.Lock() + defer d.mu.Unlock() + + // Decrease refcount if there is an endpoint associated with this file. + if d.endpoint != nil { + d.endpoint.RemoveNotify(d.notifyHandle) + d.endpoint.DecRef() + d.endpoint = nil + } +} + +// SetIff services TUNSETIFF ioctl(2) request. +func (d *Device) SetIff(s *stack.Stack, name string, flags uint16) error { + d.mu.Lock() + defer d.mu.Unlock() + + if d.endpoint != nil { + return syserror.EINVAL + } + + // Input validations. + isTun := flags&linux.IFF_TUN != 0 + isTap := flags&linux.IFF_TAP != 0 + supportedFlags := uint16(linux.IFF_TUN | linux.IFF_TAP | linux.IFF_NO_PI) + if isTap && isTun || !isTap && !isTun || flags&^supportedFlags != 0 { + return syserror.EINVAL + } + + prefix := "tun" + if isTap { + prefix = "tap" + } + + endpoint, err := attachOrCreateNIC(s, name, prefix) + if err != nil { + return syserror.EINVAL + } + + d.endpoint = endpoint + d.notifyHandle = d.endpoint.AddNotify(d) + d.flags = flags + return nil +} + +func attachOrCreateNIC(s *stack.Stack, name, prefix string) (*tunEndpoint, error) { + for { + // 1. Try to attach to an existing NIC. + if name != "" { + if nic, found := s.GetNICByName(name); found { + endpoint, ok := nic.LinkEndpoint().(*tunEndpoint) + if !ok { + // Not a NIC created by tun device. + return nil, syserror.EOPNOTSUPP + } + if !endpoint.TryIncRef() { + // Race detected: NIC got deleted in between. + continue + } + return endpoint, nil + } + } + + // 2. Creating a new NIC. + id := tcpip.NICID(s.UniqueID()) + endpoint := &tunEndpoint{ + Endpoint: channel.New(defaultDevOutQueueLen, defaultDevMtu, ""), + stack: s, + nicID: id, + name: name, + } + if endpoint.name == "" { + endpoint.name = fmt.Sprintf("%s%d", prefix, id) + } + err := s.CreateNICWithOptions(endpoint.nicID, endpoint, stack.NICOptions{ + Name: endpoint.name, + }) + switch err { + case nil: + return endpoint, nil + case tcpip.ErrDuplicateNICID: + // Race detected: A NIC has been created in between. + continue + default: + return nil, syserror.EINVAL + } + } +} + +// Write inject one inbound packet to the network interface. +func (d *Device) Write(data []byte) (int64, error) { + d.mu.RLock() + endpoint := d.endpoint + d.mu.RUnlock() + if endpoint == nil { + return 0, syserror.EBADFD + } + if !endpoint.IsAttached() { + return 0, syserror.EIO + } + + dataLen := int64(len(data)) + + // Packet information. + var pktInfoHdr PacketInfoHeader + if !d.hasFlags(linux.IFF_NO_PI) { + if len(data) < PacketInfoHeaderSize { + // Ignore bad packet. + return dataLen, nil + } + pktInfoHdr = PacketInfoHeader(data[:PacketInfoHeaderSize]) + data = data[PacketInfoHeaderSize:] + } + + // Ethernet header (TAP only). + var ethHdr header.Ethernet + if d.hasFlags(linux.IFF_TAP) { + if len(data) < header.EthernetMinimumSize { + // Ignore bad packet. + return dataLen, nil + } + ethHdr = header.Ethernet(data[:header.EthernetMinimumSize]) + data = data[header.EthernetMinimumSize:] + } + + // Try to determine network protocol number, default zero. + var protocol tcpip.NetworkProtocolNumber + switch { + case pktInfoHdr != nil: + protocol = pktInfoHdr.Protocol() + case ethHdr != nil: + protocol = ethHdr.Type() + } + + // Try to determine remote link address, default zero. + var remote tcpip.LinkAddress + switch { + case ethHdr != nil: + remote = ethHdr.SourceAddress() + default: + remote = tcpip.LinkAddress(zeroMAC[:]) + } + + pkt := tcpip.PacketBuffer{ + Data: buffer.View(data).ToVectorisedView(), + } + if ethHdr != nil { + pkt.LinkHeader = buffer.View(ethHdr) + } + endpoint.InjectLinkAddr(protocol, remote, pkt) + return dataLen, nil +} + +// Read reads one outgoing packet from the network interface. +func (d *Device) Read() ([]byte, error) { + d.mu.RLock() + endpoint := d.endpoint + d.mu.RUnlock() + if endpoint == nil { + return nil, syserror.EBADFD + } + + for { + info, ok := endpoint.Read() + if !ok { + return nil, syserror.ErrWouldBlock + } + + v, ok := d.encodePkt(&info) + if !ok { + // Ignore unsupported packet. + continue + } + return v, nil + } +} + +// encodePkt encodes packet for fd side. +func (d *Device) encodePkt(info *channel.PacketInfo) (buffer.View, bool) { + var vv buffer.VectorisedView + + // Packet information. + if !d.hasFlags(linux.IFF_NO_PI) { + hdr := make(PacketInfoHeader, PacketInfoHeaderSize) + hdr.Encode(&PacketInfoFields{ + Protocol: info.Proto, + }) + vv.AppendView(buffer.View(hdr)) + } + + // If the packet does not already have link layer header, and the route + // does not exist, we can't compute it. This is possibly a raw packet, tun + // device doesn't support this at the moment. + if info.Pkt.LinkHeader == nil && info.Route.RemoteLinkAddress == "" { + return nil, false + } + + // Ethernet header (TAP only). + if d.hasFlags(linux.IFF_TAP) { + // Add ethernet header if not provided. + if info.Pkt.LinkHeader == nil { + hdr := &header.EthernetFields{ + SrcAddr: info.Route.LocalLinkAddress, + DstAddr: info.Route.RemoteLinkAddress, + Type: info.Proto, + } + if hdr.SrcAddr == "" { + hdr.SrcAddr = d.endpoint.LinkAddress() + } + + eth := make(header.Ethernet, header.EthernetMinimumSize) + eth.Encode(hdr) + vv.AppendView(buffer.View(eth)) + } else { + vv.AppendView(info.Pkt.LinkHeader) + } + } + + // Append upper headers. + vv.AppendView(buffer.View(info.Pkt.Header.View()[len(info.Pkt.LinkHeader):])) + // Append data payload. + vv.Append(info.Pkt.Data) + + return vv.ToView(), true +} + +// Name returns the name of the attached network interface. Empty string if +// unattached. +func (d *Device) Name() string { + d.mu.RLock() + defer d.mu.RUnlock() + if d.endpoint != nil { + return d.endpoint.name + } + return "" +} + +// Flags returns the flags set for d. Zero value if unset. +func (d *Device) Flags() uint16 { + d.mu.RLock() + defer d.mu.RUnlock() + return d.flags +} + +func (d *Device) hasFlags(flags uint16) bool { + return d.flags&flags == flags +} + +// Readiness implements watier.Waitable.Readiness. +func (d *Device) Readiness(mask waiter.EventMask) waiter.EventMask { + if mask&waiter.EventIn != 0 { + d.mu.RLock() + endpoint := d.endpoint + d.mu.RUnlock() + if endpoint != nil && endpoint.NumQueued() == 0 { + mask &= ^waiter.EventIn + } + } + return mask & (waiter.EventIn | waiter.EventOut) +} + +// WriteNotify implements channel.Notification.WriteNotify. +func (d *Device) WriteNotify() { + d.Notify(waiter.EventIn) +} + +// tunEndpoint is the link endpoint for the NIC created by the tun device. +// +// It is ref-counted as multiple opening files can attach to the same NIC. +// The last owner is responsible for deleting the NIC. +type tunEndpoint struct { + *channel.Endpoint + + refs.AtomicRefCount + + stack *stack.Stack + nicID tcpip.NICID + name string +} + +// DecRef decrements refcount of e, removes NIC if refcount goes to 0. +func (e *tunEndpoint) DecRef() { + e.DecRefWithDestructor(func() { + e.stack.RemoveNIC(e.nicID) + }) +} diff --git a/pkg/tcpip/link/tun/protocol.go b/pkg/tcpip/link/tun/protocol.go new file mode 100644 index 000000000..89d9d91a9 --- /dev/null +++ b/pkg/tcpip/link/tun/protocol.go @@ -0,0 +1,56 @@ +// 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 tun + +import ( + "encoding/binary" + + "gvisor.dev/gvisor/pkg/tcpip" +) + +const ( + // PacketInfoHeaderSize is the size of the packet information header. + PacketInfoHeaderSize = 4 + + offsetFlags = 0 + offsetProtocol = 2 +) + +// PacketInfoFields contains fields sent through the wire if IFF_NO_PI flag is +// not set. +type PacketInfoFields struct { + Flags uint16 + Protocol tcpip.NetworkProtocolNumber +} + +// PacketInfoHeader is the wire representation of the packet information sent if +// IFF_NO_PI flag is not set. +type PacketInfoHeader []byte + +// Encode encodes f into h. +func (h PacketInfoHeader) Encode(f *PacketInfoFields) { + binary.BigEndian.PutUint16(h[offsetFlags:][:2], f.Flags) + binary.BigEndian.PutUint16(h[offsetProtocol:][:2], uint16(f.Protocol)) +} + +// Flags returns the flag field in h. +func (h PacketInfoHeader) Flags() uint16 { + return binary.BigEndian.Uint16(h[offsetFlags:]) +} + +// Protocol returns the protocol field in h. +func (h PacketInfoHeader) Protocol() tcpip.NetworkProtocolNumber { + return tcpip.NetworkProtocolNumber(binary.BigEndian.Uint16(h[offsetProtocol:])) +} diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index 862954ab2..46d3a6646 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -298,6 +298,33 @@ func (n *NIC) enable() *tcpip.Error { return nil } +// remove detaches NIC from the link endpoint, and marks existing referenced +// network endpoints expired. This guarantees no packets between this NIC and +// the network stack. +func (n *NIC) remove() *tcpip.Error { + n.mu.Lock() + defer n.mu.Unlock() + + // Detach from link endpoint, so no packet comes in. + n.linkEP.Attach(nil) + + // Remove permanent and permanentTentative addresses, so no packet goes out. + var errs []*tcpip.Error + for nid, ref := range n.mu.endpoints { + switch ref.getKind() { + case permanentTentative, permanent: + if err := n.removePermanentAddressLocked(nid.LocalAddress); err != nil { + errs = append(errs, err) + } + } + } + if len(errs) > 0 { + return errs[0] + } + + return nil +} + // becomeIPv6Router transitions n into an IPv6 router. // // When transitioning into an IPv6 router, host-only state (NDP discovered @@ -1302,6 +1329,11 @@ func (n *NIC) Stack() *Stack { return n.stack } +// LinkEndpoint returns the link endpoint of n. +func (n *NIC) LinkEndpoint() LinkEndpoint { + return n.linkEP +} + // isAddrTentative returns true if addr is tentative on n. // // Note that if addr is not associated with n, then this function will return diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index f0ed76fbe..900dd46c5 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -916,6 +916,18 @@ func (s *Stack) CreateNIC(id tcpip.NICID, ep LinkEndpoint) *tcpip.Error { return s.CreateNICWithOptions(id, ep, NICOptions{}) } +// GetNICByName gets the NIC specified by name. +func (s *Stack) GetNICByName(name string) (*NIC, bool) { + s.mu.RLock() + defer s.mu.RUnlock() + for _, nic := range s.nics { + if nic.Name() == name { + return nic, true + } + } + return nil, false +} + // EnableNIC enables the given NIC so that the link-layer endpoint can start // delivering packets to it. func (s *Stack) EnableNIC(id tcpip.NICID) *tcpip.Error { @@ -956,6 +968,33 @@ func (s *Stack) CheckNIC(id tcpip.NICID) bool { return nic.enabled() } +// RemoveNIC removes NIC and all related routes from the network stack. +func (s *Stack) RemoveNIC(id tcpip.NICID) *tcpip.Error { + s.mu.Lock() + defer s.mu.Unlock() + + nic, ok := s.nics[id] + if !ok { + return tcpip.ErrUnknownNICID + } + delete(s.nics, id) + + // Remove routes in-place. n tracks the number of routes written. + n := 0 + for i, r := range s.routeTable { + if r.NIC != id { + // Keep this route. + if i > n { + s.routeTable[n] = r + } + n++ + } + } + s.routeTable = s.routeTable[:n] + + return nic.remove() +} + // NICAddressRanges returns a map of NICIDs to their associated subnets. func (s *Stack) NICAddressRanges() map[tcpip.NICID][]tcpip.Subnet { s.mu.RLock() diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD index d1977d4de..3518e862d 100644 --- a/test/syscalls/BUILD +++ b/test/syscalls/BUILD @@ -678,6 +678,8 @@ syscall_test( test = "//test/syscalls/linux:truncate_test", ) +syscall_test(test = "//test/syscalls/linux:tuntap_test") + syscall_test(test = "//test/syscalls/linux:udp_bind_test") syscall_test( diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index aa303af84..704bae17b 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -131,6 +131,17 @@ cc_library( ], ) +cc_library( + name = "socket_netlink_route_util", + testonly = 1, + srcs = ["socket_netlink_route_util.cc"], + hdrs = ["socket_netlink_route_util.h"], + deps = [ + ":socket_netlink_util", + "@com_google_absl//absl/types:optional", + ], +) + cc_library( name = "socket_test_util", testonly = 1, @@ -3430,6 +3441,25 @@ cc_binary( ], ) +cc_binary( + name = "tuntap_test", + testonly = 1, + srcs = ["tuntap.cc"], + linkstatic = 1, + deps = [ + ":socket_test_util", + gtest, + "//test/syscalls/linux:socket_netlink_route_util", + "//test/util:capability_util", + "//test/util:file_descriptor", + "//test/util:fs_util", + "//test/util:posix_error", + "//test/util:test_main", + "//test/util:test_util", + "@com_google_absl//absl/strings", + ], +) + cc_library( name = "udp_socket_test_cases", testonly = 1, diff --git a/test/syscalls/linux/dev.cc b/test/syscalls/linux/dev.cc index 4dd302eed..4e473268c 100644 --- a/test/syscalls/linux/dev.cc +++ b/test/syscalls/linux/dev.cc @@ -153,6 +153,13 @@ TEST(DevTest, TTYExists) { EXPECT_EQ(statbuf.st_mode, S_IFCHR | 0666); } +TEST(DevTest, NetTunExists) { + struct stat statbuf = {}; + ASSERT_THAT(stat("/dev/net/tun", &statbuf), SyscallSucceeds()); + // Check that it's a character device with rw-rw-rw- permissions. + EXPECT_EQ(statbuf.st_mode, S_IFCHR | 0666); +} + } // namespace } // namespace testing diff --git a/test/syscalls/linux/socket_netlink_route_util.cc b/test/syscalls/linux/socket_netlink_route_util.cc new file mode 100644 index 000000000..53eb3b6b2 --- /dev/null +++ b/test/syscalls/linux/socket_netlink_route_util.cc @@ -0,0 +1,163 @@ +// 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. + +#include "test/syscalls/linux/socket_netlink_route_util.h" + +#include +#include +#include + +#include "absl/types/optional.h" +#include "test/syscalls/linux/socket_netlink_util.h" + +namespace gvisor { +namespace testing { +namespace { + +constexpr uint32_t kSeq = 12345; + +} // namespace + +PosixError DumpLinks( + const FileDescriptor& fd, uint32_t seq, + const std::function& fn) { + struct request { + struct nlmsghdr hdr; + struct ifinfomsg ifm; + }; + + struct request req = {}; + req.hdr.nlmsg_len = sizeof(req); + req.hdr.nlmsg_type = RTM_GETLINK; + req.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP; + req.hdr.nlmsg_seq = seq; + req.ifm.ifi_family = AF_UNSPEC; + + return NetlinkRequestResponse(fd, &req, sizeof(req), fn, false); +} + +PosixErrorOr> DumpLinks() { + ASSIGN_OR_RETURN_ERRNO(FileDescriptor fd, NetlinkBoundSocket(NETLINK_ROUTE)); + + std::vector links; + RETURN_IF_ERRNO(DumpLinks(fd, kSeq, [&](const struct nlmsghdr* hdr) { + if (hdr->nlmsg_type != RTM_NEWLINK || + hdr->nlmsg_len < NLMSG_SPACE(sizeof(struct ifinfomsg))) { + return; + } + const struct ifinfomsg* msg = + reinterpret_cast(NLMSG_DATA(hdr)); + const auto* rta = FindRtAttr(hdr, msg, IFLA_IFNAME); + if (rta == nullptr) { + // Ignore links that do not have a name. + return; + } + + links.emplace_back(); + links.back().index = msg->ifi_index; + links.back().type = msg->ifi_type; + links.back().name = + std::string(reinterpret_cast(RTA_DATA(rta))); + })); + return links; +} + +PosixErrorOr> FindLoopbackLink() { + ASSIGN_OR_RETURN_ERRNO(auto links, DumpLinks()); + for (const auto& link : links) { + if (link.type == ARPHRD_LOOPBACK) { + return absl::optional(link); + } + } + return absl::optional(); +} + +PosixError LinkAddLocalAddr(int index, int family, int prefixlen, + const void* addr, int addrlen) { + ASSIGN_OR_RETURN_ERRNO(FileDescriptor fd, NetlinkBoundSocket(NETLINK_ROUTE)); + + struct request { + struct nlmsghdr hdr; + struct ifaddrmsg ifaddr; + char attrbuf[512]; + }; + + struct request req = {}; + req.hdr.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifaddr)); + req.hdr.nlmsg_type = RTM_NEWADDR; + req.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + req.hdr.nlmsg_seq = kSeq; + req.ifaddr.ifa_index = index; + req.ifaddr.ifa_family = family; + req.ifaddr.ifa_prefixlen = prefixlen; + + struct rtattr* rta = reinterpret_cast( + reinterpret_cast(&req) + NLMSG_ALIGN(req.hdr.nlmsg_len)); + rta->rta_type = IFA_LOCAL; + rta->rta_len = RTA_LENGTH(addrlen); + req.hdr.nlmsg_len = NLMSG_ALIGN(req.hdr.nlmsg_len) + RTA_LENGTH(addrlen); + memcpy(RTA_DATA(rta), addr, addrlen); + + return NetlinkRequestAckOrError(fd, kSeq, &req, req.hdr.nlmsg_len); +} + +PosixError LinkChangeFlags(int index, unsigned int flags, unsigned int change) { + ASSIGN_OR_RETURN_ERRNO(FileDescriptor fd, NetlinkBoundSocket(NETLINK_ROUTE)); + + struct request { + struct nlmsghdr hdr; + struct ifinfomsg ifinfo; + char pad[NLMSG_ALIGNTO]; + }; + + struct request req = {}; + req.hdr.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifinfo)); + req.hdr.nlmsg_type = RTM_NEWLINK; + req.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + req.hdr.nlmsg_seq = kSeq; + req.ifinfo.ifi_index = index; + req.ifinfo.ifi_flags = flags; + req.ifinfo.ifi_change = change; + + return NetlinkRequestAckOrError(fd, kSeq, &req, req.hdr.nlmsg_len); +} + +PosixError LinkSetMacAddr(int index, const void* addr, int addrlen) { + ASSIGN_OR_RETURN_ERRNO(FileDescriptor fd, NetlinkBoundSocket(NETLINK_ROUTE)); + + struct request { + struct nlmsghdr hdr; + struct ifinfomsg ifinfo; + char attrbuf[512]; + }; + + struct request req = {}; + req.hdr.nlmsg_len = NLMSG_LENGTH(sizeof(req.ifinfo)); + req.hdr.nlmsg_type = RTM_NEWLINK; + req.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK; + req.hdr.nlmsg_seq = kSeq; + req.ifinfo.ifi_index = index; + + struct rtattr* rta = reinterpret_cast( + reinterpret_cast(&req) + NLMSG_ALIGN(req.hdr.nlmsg_len)); + rta->rta_type = IFLA_ADDRESS; + rta->rta_len = RTA_LENGTH(addrlen); + req.hdr.nlmsg_len = NLMSG_ALIGN(req.hdr.nlmsg_len) + RTA_LENGTH(addrlen); + memcpy(RTA_DATA(rta), addr, addrlen); + + return NetlinkRequestAckOrError(fd, kSeq, &req, req.hdr.nlmsg_len); +} + +} // namespace testing +} // namespace gvisor diff --git a/test/syscalls/linux/socket_netlink_route_util.h b/test/syscalls/linux/socket_netlink_route_util.h new file mode 100644 index 000000000..2c018e487 --- /dev/null +++ b/test/syscalls/linux/socket_netlink_route_util.h @@ -0,0 +1,55 @@ +// 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. + +#ifndef GVISOR_TEST_SYSCALLS_LINUX_SOCKET_NETLINK_ROUTE_UTIL_H_ +#define GVISOR_TEST_SYSCALLS_LINUX_SOCKET_NETLINK_ROUTE_UTIL_H_ + +#include +#include + +#include + +#include "absl/types/optional.h" +#include "test/syscalls/linux/socket_netlink_util.h" + +namespace gvisor { +namespace testing { + +struct Link { + int index; + int16_t type; + std::string name; +}; + +PosixError DumpLinks(const FileDescriptor& fd, uint32_t seq, + const std::function& fn); + +PosixErrorOr> DumpLinks(); + +PosixErrorOr> FindLoopbackLink(); + +// LinkAddLocalAddr sets IFA_LOCAL attribute on the interface. +PosixError LinkAddLocalAddr(int index, int family, int prefixlen, + const void* addr, int addrlen); + +// LinkChangeFlags changes interface flags. E.g. IFF_UP. +PosixError LinkChangeFlags(int index, unsigned int flags, unsigned int change); + +// LinkSetMacAddr sets IFLA_ADDRESS attribute of the interface. +PosixError LinkSetMacAddr(int index, const void* addr, int addrlen); + +} // namespace testing +} // namespace gvisor + +#endif // GVISOR_TEST_SYSCALLS_LINUX_SOCKET_NETLINK_ROUTE_UTIL_H_ diff --git a/test/syscalls/linux/tuntap.cc b/test/syscalls/linux/tuntap.cc new file mode 100644 index 000000000..f6ac9d7b8 --- /dev/null +++ b/test/syscalls/linux/tuntap.cc @@ -0,0 +1,346 @@ +// Copyright 2019 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. + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "gmock/gmock.h" +#include "gtest/gtest.h" +#include "absl/strings/ascii.h" +#include "absl/strings/str_split.h" +#include "test/syscalls/linux/socket_netlink_route_util.h" +#include "test/syscalls/linux/socket_test_util.h" +#include "test/util/capability_util.h" +#include "test/util/file_descriptor.h" +#include "test/util/fs_util.h" +#include "test/util/posix_error.h" +#include "test/util/test_util.h" + +namespace gvisor { +namespace testing { +namespace { + +constexpr int kIPLen = 4; + +constexpr const char kDevNetTun[] = "/dev/net/tun"; +constexpr const char kTapName[] = "tap0"; + +constexpr const uint8_t kMacA[ETH_ALEN] = {0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA}; +constexpr const uint8_t kMacB[ETH_ALEN] = {0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB}; + +PosixErrorOr> DumpLinkNames() { + ASSIGN_OR_RETURN_ERRNO(auto links, DumpLinks()); + std::set names; + for (const auto& link : links) { + names.emplace(link.name); + } + return names; +} + +PosixErrorOr> GetLinkByName(const std::string& name) { + ASSIGN_OR_RETURN_ERRNO(auto links, DumpLinks()); + for (const auto& link : links) { + if (link.name == name) { + return absl::optional(link); + } + } + return absl::optional(); +} + +struct pihdr { + uint16_t pi_flags; + uint16_t pi_protocol; +} __attribute__((packed)); + +struct ping_pkt { + pihdr pi; + struct ethhdr eth; + struct iphdr ip; + struct icmphdr icmp; + char payload[64]; +} __attribute__((packed)); + +ping_pkt CreatePingPacket(const uint8_t srcmac[ETH_ALEN], const char* srcip, + const uint8_t dstmac[ETH_ALEN], const char* dstip) { + ping_pkt pkt = {}; + + pkt.pi.pi_protocol = htons(ETH_P_IP); + + memcpy(pkt.eth.h_dest, dstmac, sizeof(pkt.eth.h_dest)); + memcpy(pkt.eth.h_source, srcmac, sizeof(pkt.eth.h_source)); + pkt.eth.h_proto = htons(ETH_P_IP); + + pkt.ip.ihl = 5; + pkt.ip.version = 4; + pkt.ip.tos = 0; + pkt.ip.tot_len = htons(sizeof(struct iphdr) + sizeof(struct icmphdr) + + sizeof(pkt.payload)); + pkt.ip.id = 1; + pkt.ip.frag_off = 1 << 6; // Do not fragment + pkt.ip.ttl = 64; + pkt.ip.protocol = IPPROTO_ICMP; + inet_pton(AF_INET, dstip, &pkt.ip.daddr); + inet_pton(AF_INET, srcip, &pkt.ip.saddr); + pkt.ip.check = IPChecksum(pkt.ip); + + pkt.icmp.type = ICMP_ECHO; + pkt.icmp.code = 0; + pkt.icmp.checksum = 0; + pkt.icmp.un.echo.sequence = 1; + pkt.icmp.un.echo.id = 1; + + strncpy(pkt.payload, "abcd", sizeof(pkt.payload)); + pkt.icmp.checksum = ICMPChecksum(pkt.icmp, pkt.payload, sizeof(pkt.payload)); + + return pkt; +} + +struct arp_pkt { + pihdr pi; + struct ethhdr eth; + struct arphdr arp; + uint8_t arp_sha[ETH_ALEN]; + uint8_t arp_spa[kIPLen]; + uint8_t arp_tha[ETH_ALEN]; + uint8_t arp_tpa[kIPLen]; +} __attribute__((packed)); + +std::string CreateArpPacket(const uint8_t srcmac[ETH_ALEN], const char* srcip, + const uint8_t dstmac[ETH_ALEN], const char* dstip) { + std::string buffer; + buffer.resize(sizeof(arp_pkt)); + + arp_pkt* pkt = reinterpret_cast(&buffer[0]); + { + pkt->pi.pi_protocol = htons(ETH_P_ARP); + + memcpy(pkt->eth.h_dest, kMacA, sizeof(pkt->eth.h_dest)); + memcpy(pkt->eth.h_source, kMacB, sizeof(pkt->eth.h_source)); + pkt->eth.h_proto = htons(ETH_P_ARP); + + pkt->arp.ar_hrd = htons(ARPHRD_ETHER); + pkt->arp.ar_pro = htons(ETH_P_IP); + pkt->arp.ar_hln = ETH_ALEN; + pkt->arp.ar_pln = kIPLen; + pkt->arp.ar_op = htons(ARPOP_REPLY); + + memcpy(pkt->arp_sha, srcmac, sizeof(pkt->arp_sha)); + inet_pton(AF_INET, srcip, pkt->arp_spa); + memcpy(pkt->arp_tha, dstmac, sizeof(pkt->arp_tha)); + inet_pton(AF_INET, dstip, pkt->arp_tpa); + } + return buffer; +} + +} // namespace + +class TuntapTest : public ::testing::Test { + protected: + void TearDown() override { + if (ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_ADMIN))) { + // Bring back capability if we had dropped it in test case. + ASSERT_NO_ERRNO(SetCapability(CAP_NET_ADMIN, true)); + } + } +}; + +TEST_F(TuntapTest, CreateInterfaceNoCap) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_ADMIN))); + + ASSERT_NO_ERRNO(SetCapability(CAP_NET_ADMIN, false)); + + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(kDevNetTun, O_RDWR)); + + struct ifreq ifr = {}; + ifr.ifr_flags = IFF_TAP; + strncpy(ifr.ifr_name, kTapName, IFNAMSIZ); + + EXPECT_THAT(ioctl(fd.get(), TUNSETIFF, &ifr), SyscallFailsWithErrno(EPERM)); +} + +TEST_F(TuntapTest, CreateFixedNameInterface) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_ADMIN))); + + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(kDevNetTun, O_RDWR)); + + struct ifreq ifr_set = {}; + ifr_set.ifr_flags = IFF_TAP; + strncpy(ifr_set.ifr_name, kTapName, IFNAMSIZ); + EXPECT_THAT(ioctl(fd.get(), TUNSETIFF, &ifr_set), + SyscallSucceedsWithValue(0)); + + struct ifreq ifr_get = {}; + EXPECT_THAT(ioctl(fd.get(), TUNGETIFF, &ifr_get), + SyscallSucceedsWithValue(0)); + + struct ifreq ifr_expect = ifr_set; + // See __tun_chr_ioctl() in net/drivers/tun.c. + ifr_expect.ifr_flags |= IFF_NOFILTER; + + EXPECT_THAT(DumpLinkNames(), + IsPosixErrorOkAndHolds(::testing::Contains(kTapName))); + EXPECT_THAT(memcmp(&ifr_expect, &ifr_get, sizeof(ifr_get)), ::testing::Eq(0)); +} + +TEST_F(TuntapTest, CreateInterface) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_ADMIN))); + + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(kDevNetTun, O_RDWR)); + + struct ifreq ifr = {}; + ifr.ifr_flags = IFF_TAP; + // Empty ifr.ifr_name. Let kernel assign. + + EXPECT_THAT(ioctl(fd.get(), TUNSETIFF, &ifr), SyscallSucceedsWithValue(0)); + + struct ifreq ifr_get = {}; + EXPECT_THAT(ioctl(fd.get(), TUNGETIFF, &ifr_get), + SyscallSucceedsWithValue(0)); + + std::string ifname = ifr_get.ifr_name; + EXPECT_THAT(ifname, ::testing::StartsWith("tap")); + EXPECT_THAT(DumpLinkNames(), + IsPosixErrorOkAndHolds(::testing::Contains(ifname))); +} + +TEST_F(TuntapTest, InvalidReadWrite) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_ADMIN))); + + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(kDevNetTun, O_RDWR)); + + char buf[128] = {}; + EXPECT_THAT(read(fd.get(), buf, sizeof(buf)), SyscallFailsWithErrno(EBADFD)); + EXPECT_THAT(write(fd.get(), buf, sizeof(buf)), SyscallFailsWithErrno(EBADFD)); +} + +TEST_F(TuntapTest, WriteToDownDevice) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_ADMIN))); + + // FIXME: gVisor always creates enabled/up'd interfaces. + SKIP_IF(IsRunningOnGvisor()); + + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(kDevNetTun, O_RDWR)); + + // Device created should be down by default. + struct ifreq ifr = {}; + ifr.ifr_flags = IFF_TAP; + EXPECT_THAT(ioctl(fd.get(), TUNSETIFF, &ifr), SyscallSucceedsWithValue(0)); + + char buf[128] = {}; + EXPECT_THAT(write(fd.get(), buf, sizeof(buf)), SyscallFailsWithErrno(EIO)); +} + +// This test sets up a TAP device and pings kernel by sending ICMP echo request. +// +// It works as the following: +// * Open /dev/net/tun, and create kTapName interface. +// * Use rtnetlink to do initial setup of the interface: +// * Assign IP address 10.0.0.1/24 to kernel. +// * MAC address: kMacA +// * Bring up the interface. +// * Send an ICMP echo reqest (ping) packet from 10.0.0.2 (kMacB) to kernel. +// * Loop to receive packets from TAP device/fd: +// * If packet is an ICMP echo reply, it stops and passes the test. +// * If packet is an ARP request, it responds with canned reply and resends +// the +// ICMP request packet. +TEST_F(TuntapTest, PingKernel) { + SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_NET_ADMIN))); + + // Interface creation. + FileDescriptor fd = ASSERT_NO_ERRNO_AND_VALUE(Open(kDevNetTun, O_RDWR)); + + struct ifreq ifr_set = {}; + ifr_set.ifr_flags = IFF_TAP; + strncpy(ifr_set.ifr_name, kTapName, IFNAMSIZ); + EXPECT_THAT(ioctl(fd.get(), TUNSETIFF, &ifr_set), + SyscallSucceedsWithValue(0)); + + absl::optional link = + ASSERT_NO_ERRNO_AND_VALUE(GetLinkByName(kTapName)); + ASSERT_TRUE(link.has_value()); + + // Interface setup. + struct in_addr addr; + inet_pton(AF_INET, "10.0.0.1", &addr); + EXPECT_NO_ERRNO(LinkAddLocalAddr(link->index, AF_INET, /*prefixlen=*/24, + &addr, sizeof(addr))); + + if (!IsRunningOnGvisor()) { + // FIXME: gVisor doesn't support setting MAC address on interfaces yet. + EXPECT_NO_ERRNO(LinkSetMacAddr(link->index, kMacA, sizeof(kMacA))); + + // FIXME: gVisor always creates enabled/up'd interfaces. + EXPECT_NO_ERRNO(LinkChangeFlags(link->index, IFF_UP, IFF_UP)); + } + + ping_pkt ping_req = CreatePingPacket(kMacB, "10.0.0.2", kMacA, "10.0.0.1"); + std::string arp_rep = CreateArpPacket(kMacB, "10.0.0.2", kMacA, "10.0.0.1"); + + // Send ping, this would trigger an ARP request on Linux. + EXPECT_THAT(write(fd.get(), &ping_req, sizeof(ping_req)), + SyscallSucceedsWithValue(sizeof(ping_req))); + + // Receive loop to process inbound packets. + struct inpkt { + union { + pihdr pi; + ping_pkt ping; + arp_pkt arp; + }; + }; + while (1) { + inpkt r = {}; + int n = read(fd.get(), &r, sizeof(r)); + EXPECT_THAT(n, SyscallSucceeds()); + + if (n < sizeof(pihdr)) { + std::cerr << "Ignored packet, protocol: " << r.pi.pi_protocol + << " len: " << n << std::endl; + continue; + } + + // Process ARP packet. + if (n >= sizeof(arp_pkt) && r.pi.pi_protocol == htons(ETH_P_ARP)) { + // Respond with canned ARP reply. + EXPECT_THAT(write(fd.get(), arp_rep.data(), arp_rep.size()), + SyscallSucceedsWithValue(arp_rep.size())); + // First ping request might have been dropped due to mac address not in + // ARP cache. Send it again. + EXPECT_THAT(write(fd.get(), &ping_req, sizeof(ping_req)), + SyscallSucceedsWithValue(sizeof(ping_req))); + } + + // Process ping response packet. + if (n >= sizeof(ping_pkt) && r.pi.pi_protocol == ping_req.pi.pi_protocol && + r.ping.ip.protocol == ping_req.ip.protocol && + !memcmp(&r.ping.ip.saddr, &ping_req.ip.daddr, kIPLen) && + !memcmp(&r.ping.ip.daddr, &ping_req.ip.saddr, kIPLen) && + r.ping.icmp.type == 0 && r.ping.icmp.code == 0) { + // Ends and passes the test. + break; + } + } +} + +} // namespace testing +} // namespace gvisor -- cgit v1.2.3 From 6b4d36e3253238dd72d0861ac1220d147e1de8dd Mon Sep 17 00:00:00 2001 From: Ting-Yu Wang Date: Fri, 28 Feb 2020 10:37:52 -0800 Subject: Hide /dev/net/tun when using hostinet. /dev/net/tun does not currently work with hostinet. This has caused some program starts failing because it thinks the feature exists. PiperOrigin-RevId: 297876196 --- pkg/sentry/fs/dev/BUILD | 1 + pkg/sentry/fs/dev/dev.go | 7 +++++-- pkg/sentry/fs/dev/net_tun.go | 7 +++++++ pkg/sentry/kernel/kernel.go | 4 ++++ test/syscalls/BUILD | 5 +++++ test/syscalls/linux/BUILD | 12 +++++++++++ test/syscalls/linux/dev.cc | 7 ------- test/syscalls/linux/tuntap.cc | 7 +++++++ test/syscalls/linux/tuntap_hostinet.cc | 37 ++++++++++++++++++++++++++++++++++ 9 files changed, 78 insertions(+), 9 deletions(-) create mode 100644 test/syscalls/linux/tuntap_hostinet.cc (limited to 'pkg/sentry/fs/dev/dev.go') diff --git a/pkg/sentry/fs/dev/BUILD b/pkg/sentry/fs/dev/BUILD index 9b6bb26d0..9379a4d7b 100644 --- a/pkg/sentry/fs/dev/BUILD +++ b/pkg/sentry/fs/dev/BUILD @@ -26,6 +26,7 @@ go_library( "//pkg/sentry/fs/fsutil", "//pkg/sentry/fs/ramfs", "//pkg/sentry/fs/tmpfs", + "//pkg/sentry/inet", "//pkg/sentry/kernel", "//pkg/sentry/memmap", "//pkg/sentry/mm", diff --git a/pkg/sentry/fs/dev/dev.go b/pkg/sentry/fs/dev/dev.go index 7e66c29b0..acbd401a0 100644 --- a/pkg/sentry/fs/dev/dev.go +++ b/pkg/sentry/fs/dev/dev.go @@ -22,6 +22,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/ramfs" "gvisor.dev/gvisor/pkg/sentry/fs/tmpfs" + "gvisor.dev/gvisor/pkg/sentry/inet" "gvisor.dev/gvisor/pkg/usermem" ) @@ -124,10 +125,12 @@ 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{ + if isNetTunSupported(inet.StackFromContext(ctx)) { + contents["net"] = newDirectory(ctx, map[string]*fs.Inode{ "tun": newCharacterDevice(ctx, newNetTunDevice(ctx, fs.RootOwner, 0666), msrc, netTunDevMajor, netTunDevMinor), - }, msrc), + }, 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 index 755644488..dc7ad075a 100644 --- a/pkg/sentry/fs/dev/net_tun.go +++ b/pkg/sentry/fs/dev/net_tun.go @@ -20,6 +20,7 @@ import ( "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/fsutil" + "gvisor.dev/gvisor/pkg/sentry/inet" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/socket/netstack" "gvisor.dev/gvisor/pkg/syserror" @@ -168,3 +169,9 @@ func (fops *netTunFileOperations) EventRegister(e *waiter.Entry, mask waiter.Eve func (fops *netTunFileOperations) EventUnregister(e *waiter.Entry) { fops.device.EventUnregister(e) } + +// isNetTunSupported returns whether /dev/net/tun device is supported for s. +func isNetTunSupported(s inet.Stack) bool { + _, ok := s.(*netstack.Stack) + return ok +} diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go index 8b76750e9..1d627564f 100644 --- a/pkg/sentry/kernel/kernel.go +++ b/pkg/sentry/kernel/kernel.go @@ -755,6 +755,8 @@ func (ctx *createProcessContext) Value(key interface{}) interface{} { return ctx.k.GlobalInit().Leader().MountNamespaceVFS2() case fs.CtxDirentCacheLimiter: return ctx.k.DirentCacheLimiter + case inet.CtxStack: + return ctx.k.RootNetworkNamespace().Stack() case ktime.CtxRealtimeClock: return ctx.k.RealtimeClock() case limits.CtxLimits: @@ -1481,6 +1483,8 @@ func (ctx supervisorContext) Value(key interface{}) interface{} { return ctx.k.GlobalInit().Leader().MountNamespaceVFS2() case fs.CtxDirentCacheLimiter: return ctx.k.DirentCacheLimiter + case inet.CtxStack: + return ctx.k.RootNetworkNamespace().Stack() case ktime.CtxRealtimeClock: return ctx.k.RealtimeClock() case limits.CtxLimits: diff --git a/test/syscalls/BUILD b/test/syscalls/BUILD index 3518e862d..a69b0ce13 100644 --- a/test/syscalls/BUILD +++ b/test/syscalls/BUILD @@ -680,6 +680,11 @@ syscall_test( syscall_test(test = "//test/syscalls/linux:tuntap_test") +syscall_test( + add_hostinet = True, + test = "//test/syscalls/linux:tuntap_hostinet_test", +) + syscall_test(test = "//test/syscalls/linux:udp_bind_test") syscall_test( diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD index 704bae17b..70c120e42 100644 --- a/test/syscalls/linux/BUILD +++ b/test/syscalls/linux/BUILD @@ -3460,6 +3460,18 @@ cc_binary( ], ) +cc_binary( + name = "tuntap_hostinet_test", + testonly = 1, + srcs = ["tuntap_hostinet.cc"], + linkstatic = 1, + deps = [ + gtest, + "//test/util:test_main", + "//test/util:test_util", + ], +) + cc_library( name = "udp_socket_test_cases", testonly = 1, diff --git a/test/syscalls/linux/dev.cc b/test/syscalls/linux/dev.cc index 4e473268c..4dd302eed 100644 --- a/test/syscalls/linux/dev.cc +++ b/test/syscalls/linux/dev.cc @@ -153,13 +153,6 @@ TEST(DevTest, TTYExists) { EXPECT_EQ(statbuf.st_mode, S_IFCHR | 0666); } -TEST(DevTest, NetTunExists) { - struct stat statbuf = {}; - ASSERT_THAT(stat("/dev/net/tun", &statbuf), SyscallSucceeds()); - // Check that it's a character device with rw-rw-rw- permissions. - EXPECT_EQ(statbuf.st_mode, S_IFCHR | 0666); -} - } // namespace } // namespace testing diff --git a/test/syscalls/linux/tuntap.cc b/test/syscalls/linux/tuntap.cc index f6ac9d7b8..f734511d6 100644 --- a/test/syscalls/linux/tuntap.cc +++ b/test/syscalls/linux/tuntap.cc @@ -153,6 +153,13 @@ std::string CreateArpPacket(const uint8_t srcmac[ETH_ALEN], const char* srcip, } // namespace +TEST(TuntapStaticTest, NetTunExists) { + struct stat statbuf; + ASSERT_THAT(stat(kDevNetTun, &statbuf), SyscallSucceeds()); + // Check that it's a character device with rw-rw-rw- permissions. + EXPECT_EQ(statbuf.st_mode, S_IFCHR | 0666); +} + class TuntapTest : public ::testing::Test { protected: void TearDown() override { diff --git a/test/syscalls/linux/tuntap_hostinet.cc b/test/syscalls/linux/tuntap_hostinet.cc new file mode 100644 index 000000000..0c527419e --- /dev/null +++ b/test/syscalls/linux/tuntap_hostinet.cc @@ -0,0 +1,37 @@ +// 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. + +#include +#include +#include + +#include "gtest/gtest.h" +#include "test/util/test_util.h" + +namespace gvisor { +namespace testing { + +namespace { + +TEST(TuntapHostInetTest, NoNetTun) { + SKIP_IF(!IsRunningOnGvisor()); + + struct stat statbuf; + ASSERT_THAT(stat("/dev/net/tun", &statbuf), SyscallFailsWithErrno(ENOENT)); +} + +} // namespace +} // namespace testing + +} // namespace gvisor -- cgit v1.2.3