2019-07-18 22:09:14 +00:00
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// Copyright 2019 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package vfs
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import (
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"gvisor.dev/gvisor/pkg/sentry/context"
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)
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// contextID is this package's type for context.Context.Value keys.
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type contextID int
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const (
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// CtxMountNamespace is a Context.Value key for a MountNamespace.
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CtxMountNamespace contextID = iota
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2019-12-12 21:17:47 +00:00
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// CtxRoot is a Context.Value key for a VFS root.
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CtxRoot
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2019-07-18 22:09:14 +00:00
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)
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// MountNamespaceFromContext returns the MountNamespace used by ctx. It does
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// not take a reference on the returned MountNamespace. If ctx is not
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// associated with a MountNamespace, MountNamespaceFromContext returns nil.
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func MountNamespaceFromContext(ctx context.Context) *MountNamespace {
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if v := ctx.Value(CtxMountNamespace); v != nil {
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return v.(*MountNamespace)
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}
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return nil
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}
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2019-12-12 21:17:47 +00:00
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// RootFromContext returns the VFS root used by ctx. It takes a reference on
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// the returned VirtualDentry. If ctx does not have a specific VFS root,
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// RootFromContext returns a zero-value VirtualDentry.
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func RootFromContext(ctx context.Context) VirtualDentry {
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if v := ctx.Value(CtxRoot); v != nil {
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return v.(VirtualDentry)
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}
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return VirtualDentry{}
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}
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