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-rw-r--r--pkg/sentry/fs/proc/net.go5
-rw-r--r--pkg/sentry/fs/proc/sys_net.go4
-rw-r--r--pkg/sentry/fsimpl/proc/tasks_net.go5
-rw-r--r--pkg/sentry/fsimpl/proc/tasks_sys.go4
-rw-r--r--pkg/sentry/fsimpl/testutil/kernel.go1
-rw-r--r--pkg/sentry/inet/BUILD1
-rw-r--r--pkg/sentry/inet/namespace.go99
-rw-r--r--pkg/sentry/kernel/kernel.go26
-rw-r--r--pkg/sentry/kernel/task.go9
-rw-r--r--pkg/sentry/kernel/task_clone.go16
-rw-r--r--pkg/sentry/kernel/task_net.go19
-rw-r--r--pkg/sentry/kernel/task_start.go8
12 files changed, 161 insertions, 36 deletions
diff --git a/pkg/sentry/fs/proc/net.go b/pkg/sentry/fs/proc/net.go
index 6f2775344..95d5817ff 100644
--- a/pkg/sentry/fs/proc/net.go
+++ b/pkg/sentry/fs/proc/net.go
@@ -43,7 +43,10 @@ import (
// newNet creates a new proc net entry.
func (p *proc) newNetDir(ctx context.Context, k *kernel.Kernel, msrc *fs.MountSource) *fs.Inode {
var contents map[string]*fs.Inode
- if s := p.k.NetworkStack(); s != nil {
+ // TODO(gvisor.dev/issue/1833): Support for using the network stack in the
+ // network namespace of the calling process. We should make this per-process,
+ // a.k.a. /proc/PID/net, and make /proc/net a symlink to /proc/self/net.
+ if s := p.k.RootNetworkNamespace().Stack(); s != nil {
contents = map[string]*fs.Inode{
"dev": seqfile.NewSeqFileInode(ctx, &netDev{s: s}, msrc),
"snmp": seqfile.NewSeqFileInode(ctx, &netSnmp{s: s}, msrc),
diff --git a/pkg/sentry/fs/proc/sys_net.go b/pkg/sentry/fs/proc/sys_net.go
index 0772d4ae4..d4c4b533d 100644
--- a/pkg/sentry/fs/proc/sys_net.go
+++ b/pkg/sentry/fs/proc/sys_net.go
@@ -357,7 +357,9 @@ func (p *proc) newSysNetIPv4Dir(ctx context.Context, msrc *fs.MountSource, s ine
func (p *proc) newSysNetDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
var contents map[string]*fs.Inode
- if s := p.k.NetworkStack(); s != nil {
+ // TODO(gvisor.dev/issue/1833): Support for using the network stack in the
+ // network namespace of the calling process.
+ if s := p.k.RootNetworkNamespace().Stack(); s != nil {
contents = map[string]*fs.Inode{
"ipv4": p.newSysNetIPv4Dir(ctx, msrc, s),
"core": p.newSysNetCore(ctx, msrc, s),
diff --git a/pkg/sentry/fsimpl/proc/tasks_net.go b/pkg/sentry/fsimpl/proc/tasks_net.go
index 608fec017..d4e1812d8 100644
--- a/pkg/sentry/fsimpl/proc/tasks_net.go
+++ b/pkg/sentry/fsimpl/proc/tasks_net.go
@@ -39,7 +39,10 @@ import (
func newNetDir(root *auth.Credentials, inoGen InoGenerator, k *kernel.Kernel) *kernfs.Dentry {
var contents map[string]*kernfs.Dentry
- if stack := k.NetworkStack(); stack != nil {
+ // TODO(gvisor.dev/issue/1833): Support for using the network stack in the
+ // network namespace of the calling process. We should make this per-process,
+ // a.k.a. /proc/PID/net, and make /proc/net a symlink to /proc/self/net.
+ if stack := k.RootNetworkNamespace().Stack(); stack != nil {
const (
arp = "IP address HW type Flags HW address Mask Device\n"
netlink = "sk Eth Pid Groups Rmem Wmem Dump Locks Drops Inode\n"
diff --git a/pkg/sentry/fsimpl/proc/tasks_sys.go b/pkg/sentry/fsimpl/proc/tasks_sys.go
index c7ce74883..3d5dc463c 100644
--- a/pkg/sentry/fsimpl/proc/tasks_sys.go
+++ b/pkg/sentry/fsimpl/proc/tasks_sys.go
@@ -50,7 +50,9 @@ func newSysDir(root *auth.Credentials, inoGen InoGenerator, k *kernel.Kernel) *k
func newSysNetDir(root *auth.Credentials, inoGen InoGenerator, k *kernel.Kernel) *kernfs.Dentry {
var contents map[string]*kernfs.Dentry
- if stack := k.NetworkStack(); stack != nil {
+ // TODO(gvisor.dev/issue/1833): Support for using the network stack in the
+ // network namespace of the calling process.
+ if stack := k.RootNetworkNamespace().Stack(); stack != nil {
contents = map[string]*kernfs.Dentry{
"ipv4": kernfs.NewStaticDir(root, inoGen.NextIno(), 0555, map[string]*kernfs.Dentry{
"tcp_sack": newDentry(root, inoGen.NextIno(), 0644, &tcpSackData{stack: stack}),
diff --git a/pkg/sentry/fsimpl/testutil/kernel.go b/pkg/sentry/fsimpl/testutil/kernel.go
index d0be32e72..488478e29 100644
--- a/pkg/sentry/fsimpl/testutil/kernel.go
+++ b/pkg/sentry/fsimpl/testutil/kernel.go
@@ -128,6 +128,7 @@ func CreateTask(ctx context.Context, name string, tc *kernel.ThreadGroup, mntns
ThreadGroup: tc,
TaskContext: &kernel.TaskContext{Name: name},
Credentials: auth.CredentialsFromContext(ctx),
+ NetworkNamespace: k.RootNetworkNamespace(),
AllowedCPUMask: sched.NewFullCPUSet(k.ApplicationCores()),
UTSNamespace: kernel.UTSNamespaceFromContext(ctx),
IPCNamespace: kernel.IPCNamespaceFromContext(ctx),
diff --git a/pkg/sentry/inet/BUILD b/pkg/sentry/inet/BUILD
index 334432abf..07bf39fed 100644
--- a/pkg/sentry/inet/BUILD
+++ b/pkg/sentry/inet/BUILD
@@ -10,6 +10,7 @@ go_library(
srcs = [
"context.go",
"inet.go",
+ "namespace.go",
"test_stack.go",
],
deps = [
diff --git a/pkg/sentry/inet/namespace.go b/pkg/sentry/inet/namespace.go
new file mode 100644
index 000000000..c16667e7f
--- /dev/null
+++ b/pkg/sentry/inet/namespace.go
@@ -0,0 +1,99 @@
+// 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 inet
+
+// Namespace represents a network namespace. See network_namespaces(7).
+//
+// +stateify savable
+type Namespace struct {
+ // stack is the network stack implementation of this network namespace.
+ stack Stack `state:"nosave"`
+
+ // creator allows kernel to create new network stack for network namespaces.
+ // If nil, no networking will function if network is namespaced.
+ creator NetworkStackCreator
+
+ // isRoot indicates whether this is the root network namespace.
+ isRoot bool
+}
+
+// NewRootNamespace creates the root network namespace, with creator
+// allowing new network namespaces to be created. If creator is nil, no
+// networking will function if the network is namespaced.
+func NewRootNamespace(stack Stack, creator NetworkStackCreator) *Namespace {
+ return &Namespace{
+ stack: stack,
+ creator: creator,
+ isRoot: true,
+ }
+}
+
+// NewNamespace creates a new network namespace from the root.
+func NewNamespace(root *Namespace) *Namespace {
+ n := &Namespace{
+ creator: root.creator,
+ }
+ n.init()
+ return n
+}
+
+// Stack returns the network stack of n. Stack may return nil if no network
+// stack is configured.
+func (n *Namespace) Stack() Stack {
+ return n.stack
+}
+
+// IsRoot returns whether n is the root network namespace.
+func (n *Namespace) IsRoot() bool {
+ return n.isRoot
+}
+
+// RestoreRootStack restores the root network namespace with stack. This should
+// only be called when restoring kernel.
+func (n *Namespace) RestoreRootStack(stack Stack) {
+ if !n.isRoot {
+ panic("RestoreRootStack can only be called on root network namespace")
+ }
+ if n.stack != nil {
+ panic("RestoreRootStack called after a stack has already been set")
+ }
+ n.stack = stack
+}
+
+func (n *Namespace) init() {
+ // Root network namespace will have stack assigned later.
+ if n.isRoot {
+ return
+ }
+ if n.creator != nil {
+ var err error
+ n.stack, err = n.creator.CreateStack()
+ if err != nil {
+ panic(err)
+ }
+ }
+}
+
+// afterLoad is invoked by stateify.
+func (n *Namespace) afterLoad() {
+ n.init()
+}
+
+// NetworkStackCreator allows new instances of a network stack to be created. It
+// is used by the kernel to create new network namespaces when requested.
+type NetworkStackCreator interface {
+ // CreateStack creates a new network stack for a network namespace.
+ CreateStack() (Stack, error)
+}
diff --git a/pkg/sentry/kernel/kernel.go b/pkg/sentry/kernel/kernel.go
index 7da0368f1..c62fd6eb1 100644
--- a/pkg/sentry/kernel/kernel.go
+++ b/pkg/sentry/kernel/kernel.go
@@ -111,7 +111,7 @@ type Kernel struct {
timekeeper *Timekeeper
tasks *TaskSet
rootUserNamespace *auth.UserNamespace
- networkStack inet.Stack `state:"nosave"`
+ rootNetworkNamespace *inet.Namespace
applicationCores uint
useHostCores bool
extraAuxv []arch.AuxEntry
@@ -260,8 +260,9 @@ type InitKernelArgs struct {
// RootUserNamespace is the root user namespace.
RootUserNamespace *auth.UserNamespace
- // NetworkStack is the TCP/IP network stack. NetworkStack may be nil.
- NetworkStack inet.Stack
+ // RootNetworkNamespace is the root network namespace. If nil, no networking
+ // will be available.
+ RootNetworkNamespace *inet.Namespace
// ApplicationCores is the number of logical CPUs visible to sandboxed
// applications. The set of logical CPU IDs is [0, ApplicationCores); thus
@@ -320,7 +321,10 @@ func (k *Kernel) Init(args InitKernelArgs) error {
k.rootUTSNamespace = args.RootUTSNamespace
k.rootIPCNamespace = args.RootIPCNamespace
k.rootAbstractSocketNamespace = args.RootAbstractSocketNamespace
- k.networkStack = args.NetworkStack
+ k.rootNetworkNamespace = args.RootNetworkNamespace
+ if k.rootNetworkNamespace == nil {
+ k.rootNetworkNamespace = inet.NewRootNamespace(nil, nil)
+ }
k.applicationCores = args.ApplicationCores
if args.UseHostCores {
k.useHostCores = true
@@ -543,8 +547,6 @@ func (ts *TaskSet) unregisterEpollWaiters() {
func (k *Kernel) LoadFrom(r io.Reader, net inet.Stack, clocks sentrytime.Clocks) error {
loadStart := time.Now()
- k.networkStack = net
-
initAppCores := k.applicationCores
// Load the pre-saved CPUID FeatureSet.
@@ -575,6 +577,10 @@ func (k *Kernel) LoadFrom(r io.Reader, net inet.Stack, clocks sentrytime.Clocks)
log.Infof("Kernel load stats: %s", &stats)
log.Infof("Kernel load took [%s].", time.Since(kernelStart))
+ // rootNetworkNamespace should be populated after loading the state file.
+ // Restore the root network stack.
+ k.rootNetworkNamespace.RestoreRootStack(net)
+
// Load the memory file's state.
memoryStart := time.Now()
if err := k.mf.LoadFrom(k.SupervisorContext(), r); err != nil {
@@ -905,6 +911,7 @@ func (k *Kernel) CreateProcess(args CreateProcessArgs) (*ThreadGroup, ThreadID,
FSContext: fsContext,
FDTable: args.FDTable,
Credentials: args.Credentials,
+ NetworkNamespace: k.RootNetworkNamespace(),
AllowedCPUMask: sched.NewFullCPUSet(k.applicationCores),
UTSNamespace: args.UTSNamespace,
IPCNamespace: args.IPCNamespace,
@@ -1255,10 +1262,9 @@ func (k *Kernel) RootAbstractSocketNamespace() *AbstractSocketNamespace {
return k.rootAbstractSocketNamespace
}
-// NetworkStack returns the network stack. NetworkStack may return nil if no
-// network stack is available.
-func (k *Kernel) NetworkStack() inet.Stack {
- return k.networkStack
+// RootNetworkNamespace returns the root network namespace, always non-nil.
+func (k *Kernel) RootNetworkNamespace() *inet.Namespace {
+ return k.rootNetworkNamespace
}
// GlobalInit returns the thread group with ID 1 in the root PID namespace, or
diff --git a/pkg/sentry/kernel/task.go b/pkg/sentry/kernel/task.go
index a3443ff21..e37e23231 100644
--- a/pkg/sentry/kernel/task.go
+++ b/pkg/sentry/kernel/task.go
@@ -486,13 +486,10 @@ type Task struct {
numaPolicy int32
numaNodeMask uint64
- // If netns is true, the task is in a non-root network namespace. Network
- // namespaces aren't currently implemented in full; being in a network
- // namespace simply prevents the task from observing any network devices
- // (including loopback) or using abstract socket addresses (see unix(7)).
+ // netns is the task's network namespace. netns is never nil.
//
- // netns is protected by mu. netns is owned by the task goroutine.
- netns bool
+ // netns is protected by mu.
+ netns *inet.Namespace
// If rseqPreempted is true, before the next call to p.Switch(),
// interrupt rseq critical regions as defined by rseqAddr and
diff --git a/pkg/sentry/kernel/task_clone.go b/pkg/sentry/kernel/task_clone.go
index ba74b4c1c..78866f280 100644
--- a/pkg/sentry/kernel/task_clone.go
+++ b/pkg/sentry/kernel/task_clone.go
@@ -17,6 +17,7 @@ package kernel
import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/bpf"
+ "gvisor.dev/gvisor/pkg/sentry/inet"
"gvisor.dev/gvisor/pkg/syserror"
"gvisor.dev/gvisor/pkg/usermem"
)
@@ -54,8 +55,7 @@ type SharingOptions struct {
NewUserNamespace bool
// If NewNetworkNamespace is true, the task should have an independent
- // network namespace. (Note that network namespaces are not really
- // implemented; see comment on Task.netns for details.)
+ // network namespace.
NewNetworkNamespace bool
// If NewFiles is true, the task should use an independent file descriptor
@@ -199,6 +199,11 @@ func (t *Task) Clone(opts *CloneOptions) (ThreadID, *SyscallControl, error) {
ipcns = NewIPCNamespace(userns)
}
+ netns := t.NetworkNamespace()
+ if opts.NewNetworkNamespace {
+ netns = inet.NewNamespace(netns)
+ }
+
// TODO(b/63601033): Implement CLONE_NEWNS.
mntnsVFS2 := t.mountNamespaceVFS2
if mntnsVFS2 != nil {
@@ -268,7 +273,7 @@ func (t *Task) Clone(opts *CloneOptions) (ThreadID, *SyscallControl, error) {
FDTable: fdTable,
Credentials: creds,
Niceness: t.Niceness(),
- NetworkNamespaced: t.netns,
+ NetworkNamespace: netns,
AllowedCPUMask: t.CPUMask(),
UTSNamespace: utsns,
IPCNamespace: ipcns,
@@ -283,9 +288,6 @@ func (t *Task) Clone(opts *CloneOptions) (ThreadID, *SyscallControl, error) {
} else {
cfg.InheritParent = t
}
- if opts.NewNetworkNamespace {
- cfg.NetworkNamespaced = true
- }
nt, err := t.tg.pidns.owner.NewTask(cfg)
if err != nil {
if opts.NewThreadGroup {
@@ -482,7 +484,7 @@ func (t *Task) Unshare(opts *SharingOptions) error {
t.mu.Unlock()
return syserror.EPERM
}
- t.netns = true
+ t.netns = inet.NewNamespace(t.netns)
}
if opts.NewUTSNamespace {
if !haveCapSysAdmin {
diff --git a/pkg/sentry/kernel/task_net.go b/pkg/sentry/kernel/task_net.go
index 172a31e1d..f7711232c 100644
--- a/pkg/sentry/kernel/task_net.go
+++ b/pkg/sentry/kernel/task_net.go
@@ -22,14 +22,23 @@ import (
func (t *Task) IsNetworkNamespaced() bool {
t.mu.Lock()
defer t.mu.Unlock()
- return t.netns
+ return !t.netns.IsRoot()
}
// NetworkContext returns the network stack used by the task. NetworkContext
// may return nil if no network stack is available.
+//
+// TODO(gvisor.dev/issue/1833): Migrate callers of this method to
+// NetworkNamespace().
func (t *Task) NetworkContext() inet.Stack {
- if t.IsNetworkNamespaced() {
- return nil
- }
- return t.k.networkStack
+ t.mu.Lock()
+ defer t.mu.Unlock()
+ return t.netns.Stack()
+}
+
+// NetworkNamespace returns the network namespace observed by the task.
+func (t *Task) NetworkNamespace() *inet.Namespace {
+ t.mu.Lock()
+ defer t.mu.Unlock()
+ return t.netns
}
diff --git a/pkg/sentry/kernel/task_start.go b/pkg/sentry/kernel/task_start.go
index f9236a842..a5035bb7f 100644
--- a/pkg/sentry/kernel/task_start.go
+++ b/pkg/sentry/kernel/task_start.go
@@ -17,6 +17,7 @@ package kernel
import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/inet"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/kernel/futex"
"gvisor.dev/gvisor/pkg/sentry/kernel/sched"
@@ -65,9 +66,8 @@ type TaskConfig struct {
// Niceness is the niceness of the new task.
Niceness int
- // If NetworkNamespaced is true, the new task should observe a non-root
- // network namespace.
- NetworkNamespaced bool
+ // NetworkNamespace is the network namespace to be used for the new task.
+ NetworkNamespace *inet.Namespace
// AllowedCPUMask contains the cpus that this task can run on.
AllowedCPUMask sched.CPUSet
@@ -133,7 +133,7 @@ func (ts *TaskSet) newTask(cfg *TaskConfig) (*Task, error) {
allowedCPUMask: cfg.AllowedCPUMask.Copy(),
ioUsage: &usage.IO{},
niceness: cfg.Niceness,
- netns: cfg.NetworkNamespaced,
+ netns: cfg.NetworkNamespace,
utsns: cfg.UTSNamespace,
ipcns: cfg.IPCNamespace,
abstractSockets: cfg.AbstractSocketNamespace,
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 21:15:16 +0000