112 lines
2.8 KiB
Go
112 lines
2.8 KiB
Go
// Copyright 2018 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 kernel
|
|
|
|
import (
|
|
"sync"
|
|
"syscall"
|
|
|
|
"gvisor.dev/gvisor/pkg/refs"
|
|
"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
|
|
)
|
|
|
|
// +stateify savable
|
|
type abstractEndpoint struct {
|
|
ep transport.BoundEndpoint
|
|
wr *refs.WeakRef
|
|
name string
|
|
ns *AbstractSocketNamespace
|
|
}
|
|
|
|
// WeakRefGone implements refs.WeakRefUser.WeakRefGone.
|
|
func (e *abstractEndpoint) WeakRefGone() {
|
|
e.ns.mu.Lock()
|
|
if e.ns.endpoints[e.name].ep == e.ep {
|
|
delete(e.ns.endpoints, e.name)
|
|
}
|
|
e.ns.mu.Unlock()
|
|
}
|
|
|
|
// AbstractSocketNamespace is used to implement the Linux abstract socket functionality.
|
|
//
|
|
// +stateify savable
|
|
type AbstractSocketNamespace struct {
|
|
mu sync.Mutex `state:"nosave"`
|
|
|
|
// Keeps mapping from name to endpoint.
|
|
endpoints map[string]abstractEndpoint
|
|
}
|
|
|
|
// NewAbstractSocketNamespace returns a new AbstractSocketNamespace.
|
|
func NewAbstractSocketNamespace() *AbstractSocketNamespace {
|
|
return &AbstractSocketNamespace{
|
|
endpoints: make(map[string]abstractEndpoint),
|
|
}
|
|
}
|
|
|
|
// A boundEndpoint wraps a transport.BoundEndpoint to maintain a reference on
|
|
// its backing object.
|
|
type boundEndpoint struct {
|
|
transport.BoundEndpoint
|
|
rc refs.RefCounter
|
|
}
|
|
|
|
// Release implements transport.BoundEndpoint.Release.
|
|
func (e *boundEndpoint) Release() {
|
|
e.rc.DecRef()
|
|
e.BoundEndpoint.Release()
|
|
}
|
|
|
|
// BoundEndpoint retrieves the endpoint bound to the given name. The return
|
|
// value is nil if no endpoint was bound.
|
|
func (a *AbstractSocketNamespace) BoundEndpoint(name string) transport.BoundEndpoint {
|
|
a.mu.Lock()
|
|
defer a.mu.Unlock()
|
|
|
|
ep, ok := a.endpoints[name]
|
|
if !ok {
|
|
return nil
|
|
}
|
|
|
|
rc := ep.wr.Get()
|
|
if rc == nil {
|
|
delete(a.endpoints, name)
|
|
return nil
|
|
}
|
|
|
|
return &boundEndpoint{ep.ep, rc}
|
|
}
|
|
|
|
// Bind binds the given socket.
|
|
//
|
|
// When the last reference managed by rc is dropped, ep may be removed from the
|
|
// namespace.
|
|
func (a *AbstractSocketNamespace) Bind(name string, ep transport.BoundEndpoint, rc refs.RefCounter) error {
|
|
a.mu.Lock()
|
|
defer a.mu.Unlock()
|
|
|
|
if ep, ok := a.endpoints[name]; ok {
|
|
if rc := ep.wr.Get(); rc != nil {
|
|
rc.DecRef()
|
|
return syscall.EADDRINUSE
|
|
}
|
|
}
|
|
|
|
ae := abstractEndpoint{ep: ep, name: name, ns: a}
|
|
ae.wr = refs.NewWeakRef(rc, &ae)
|
|
a.endpoints[name] = ae
|
|
return nil
|
|
}
|