github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/sentry/kernel/ipc_namespace.go (about)

     1  // Copyright 2018 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package kernel
    16  
    17  import (
    18  	"github.com/SagerNet/gvisor/pkg/context"
    19  	"github.com/SagerNet/gvisor/pkg/sentry/kernel/auth"
    20  	"github.com/SagerNet/gvisor/pkg/sentry/kernel/semaphore"
    21  	"github.com/SagerNet/gvisor/pkg/sentry/kernel/shm"
    22  )
    23  
    24  // IPCNamespace represents an IPC namespace.
    25  //
    26  // +stateify savable
    27  type IPCNamespace struct {
    28  	IPCNamespaceRefs
    29  
    30  	// User namespace which owns this IPC namespace. Immutable.
    31  	userNS *auth.UserNamespace
    32  
    33  	semaphores *semaphore.Registry
    34  	shms       *shm.Registry
    35  }
    36  
    37  // NewIPCNamespace creates a new IPC namespace.
    38  func NewIPCNamespace(userNS *auth.UserNamespace) *IPCNamespace {
    39  	ns := &IPCNamespace{
    40  		userNS:     userNS,
    41  		semaphores: semaphore.NewRegistry(userNS),
    42  		shms:       shm.NewRegistry(userNS),
    43  	}
    44  	ns.InitRefs()
    45  	return ns
    46  }
    47  
    48  // SemaphoreRegistry returns the semaphore set registry for this namespace.
    49  func (i *IPCNamespace) SemaphoreRegistry() *semaphore.Registry {
    50  	return i.semaphores
    51  }
    52  
    53  // ShmRegistry returns the shm segment registry for this namespace.
    54  func (i *IPCNamespace) ShmRegistry() *shm.Registry {
    55  	return i.shms
    56  }
    57  
    58  // DecRef implements refsvfs2.RefCounter.DecRef.
    59  func (i *IPCNamespace) DecRef(ctx context.Context) {
    60  	i.IPCNamespaceRefs.DecRef(func() {
    61  		i.shms.Release(ctx)
    62  	})
    63  }
    64  
    65  // IPCNamespace returns the task's IPC namespace.
    66  func (t *Task) IPCNamespace() *IPCNamespace {
    67  	t.mu.Lock()
    68  	defer t.mu.Unlock()
    69  	return t.ipcns
    70  }