131 lines
3.5 KiB
Go
131 lines
3.5 KiB
Go
// Copyright 2018 Google Inc.
|
|
//
|
|
// 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 kernel
|
|
|
|
import (
|
|
"gvisor.googlesource.com/gvisor/pkg/abi/linux"
|
|
"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
|
|
)
|
|
|
|
// TaskResources is the subset of a task's data provided by its creator that is
|
|
// not provided by the loader.
|
|
type TaskResources struct {
|
|
// SignalMask is the set of signals whose delivery is currently blocked.
|
|
//
|
|
// FIXME: Determine if we also need RealSignalMask
|
|
SignalMask linux.SignalSet
|
|
|
|
// FSContext is the filesystem context.
|
|
*FSContext
|
|
|
|
// FDMap provides access to files to the task.
|
|
*FDMap
|
|
|
|
// Tracks abstract sockets that are in use.
|
|
AbstractSockets *AbstractSocketNamespace
|
|
}
|
|
|
|
// newTaskResources returns a new TaskResources, taking an additional reference
|
|
// on fdm.
|
|
func newTaskResources(fdm *FDMap, fc *FSContext) *TaskResources {
|
|
fdm.IncRef()
|
|
return &TaskResources{
|
|
FDMap: fdm,
|
|
FSContext: fc,
|
|
AbstractSockets: NewAbstractSocketNamespace(),
|
|
}
|
|
}
|
|
|
|
// release releases all resources held by the TaskResources. release is called
|
|
// by the task when it exits.
|
|
func (tr *TaskResources) release() {
|
|
tr.FDMap.DecRef()
|
|
tr.FDMap = nil
|
|
tr.FSContext.DecRef()
|
|
tr.FSContext = nil
|
|
tr.AbstractSockets = nil
|
|
}
|
|
|
|
// Fork returns a duplicate of tr.
|
|
//
|
|
// FIXME: Preconditions: When tr is owned by a Task, that task's
|
|
// signal mutex must be locked, or Fork must be called by the task's goroutine.
|
|
func (tr *TaskResources) Fork(shareFiles bool, shareFSContext bool) *TaskResources {
|
|
var fdmap *FDMap
|
|
if shareFiles {
|
|
fdmap = tr.FDMap
|
|
fdmap.IncRef()
|
|
} else {
|
|
fdmap = tr.FDMap.Fork()
|
|
}
|
|
|
|
var fsc *FSContext
|
|
if shareFSContext {
|
|
fsc = tr.FSContext
|
|
fsc.IncRef()
|
|
} else {
|
|
fsc = tr.FSContext.Fork()
|
|
}
|
|
|
|
return &TaskResources{
|
|
SignalMask: tr.SignalMask,
|
|
FDMap: fdmap,
|
|
FSContext: fsc,
|
|
AbstractSockets: tr.AbstractSockets,
|
|
}
|
|
}
|
|
|
|
// FDMap returns t's FDMap.
|
|
//
|
|
// Preconditions: The caller must be running on the task goroutine, or t.mu
|
|
// must be locked.
|
|
func (t *Task) FDMap() *FDMap {
|
|
return t.tr.FDMap
|
|
}
|
|
|
|
// FSContext returns t's FSContext.
|
|
//
|
|
// Preconditions: The caller must be running on the task goroutine, or t.mu
|
|
// must be locked.
|
|
func (t *Task) FSContext() *FSContext {
|
|
return t.tr.FSContext
|
|
}
|
|
|
|
// MountNamespace returns t's MountNamespace. MountNamespace does not take an additional
|
|
// reference on the returned MountNamespace.
|
|
func (t *Task) MountNamespace() *fs.MountNamespace {
|
|
return t.k.mounts
|
|
}
|
|
|
|
// AbstractSockets returns t's AbstractSocketNamespace.
|
|
func (t *Task) AbstractSockets() *AbstractSocketNamespace {
|
|
return t.tr.AbstractSockets
|
|
}
|
|
|
|
// IsChrooted returns true if the root directory of t's FSContext is not the
|
|
// root directory of t's MountNamespace.
|
|
//
|
|
// Preconditions: The caller must be running on the task goroutine, or t.mu
|
|
// must be locked.
|
|
func (t *Task) IsChrooted() bool {
|
|
realRoot := t.k.mounts.Root()
|
|
defer realRoot.DecRef()
|
|
root := t.tr.FSContext.RootDirectory()
|
|
if root != nil {
|
|
defer root.DecRef()
|
|
}
|
|
return root != realRoot
|
|
}
|