75 lines
2.2 KiB
Go
75 lines
2.2 KiB
Go
// Copyright 2018 Google LLC
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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 ramfs
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import (
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"sync"
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"gvisor.googlesource.com/gvisor/pkg/sentry/context"
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"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
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)
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// Symlink represents a symlink.
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//
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// +stateify savable
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type Symlink struct {
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Entry
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mu sync.Mutex `state:"nosave"`
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// Target is the symlink target.
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Target string
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}
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// InitSymlink initializes a symlink, pointing to the given target.
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// A symlink is assumed to always have permissions 0777.
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func (s *Symlink) InitSymlink(ctx context.Context, owner fs.FileOwner, target string) {
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s.InitEntry(ctx, owner, fs.FilePermsFromMode(0777))
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s.Target = target
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}
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// UnstableAttr returns all attributes of this ramfs symlink.
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func (s *Symlink) UnstableAttr(ctx context.Context, inode *fs.Inode) (fs.UnstableAttr, error) {
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uattr, _ := s.Entry.UnstableAttr(ctx, inode)
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uattr.Size = int64(len(s.Target))
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uattr.Usage = uattr.Size
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return uattr, nil
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}
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// Check implements InodeOperations.Check.
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func (s *Symlink) Check(ctx context.Context, inode *fs.Inode, p fs.PermMask) bool {
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return fs.ContextCanAccessFile(ctx, inode, p)
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}
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// SetPermissions on a symlink is always rejected.
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func (s *Symlink) SetPermissions(context.Context, *fs.Inode, fs.FilePermissions) bool {
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return false
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}
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// Readlink reads the symlink value.
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func (s *Symlink) Readlink(ctx context.Context, _ *fs.Inode) (string, error) {
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s.mu.Lock()
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defer s.mu.Unlock()
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s.Entry.NotifyAccess(ctx)
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return s.Target, nil
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}
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// Getlink returns ErrResolveViaReadlink, falling back to walking to the result
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// of Readlink().
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func (*Symlink) Getlink(context.Context, *fs.Inode) (*fs.Dirent, error) {
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return nil, fs.ErrResolveViaReadlink
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}
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