2019-04-29 21:25:05 +00:00
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// Copyright 2018 The gVisor Authors.
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2018-04-27 17:37:02 +00:00
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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 proc
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import (
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"fmt"
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2019-06-13 23:49:09 +00:00
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"gvisor.dev/gvisor/pkg/sentry/context"
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"gvisor.dev/gvisor/pkg/sentry/fs"
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2018-04-27 17:37:02 +00:00
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)
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// filesystem is a procfs.
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2018-08-02 17:41:44 +00:00
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//
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// +stateify savable
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2018-04-27 17:37:02 +00:00
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type filesystem struct{}
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func init() {
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fs.RegisterFilesystem(&filesystem{})
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}
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2019-06-27 21:23:29 +00:00
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// FilesystemName is the name under which the filesystem is registered.
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2018-04-27 17:37:02 +00:00
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// Name matches fs/proc/root.c:proc_fs_type.name.
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const FilesystemName = "proc"
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// Name is the name of the file system.
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func (*filesystem) Name() string {
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return FilesystemName
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}
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// AllowUserMount allows users to mount(2) this file system.
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func (*filesystem) AllowUserMount() bool {
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return true
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}
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2018-07-13 19:10:01 +00:00
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// AllowUserList allows this filesystem to be listed in /proc/filesystems.
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func (*filesystem) AllowUserList() bool {
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return true
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}
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2018-04-27 17:37:02 +00:00
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// Flags returns that there is nothing special about this file system.
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//
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// In Linux, proc returns FS_USERNS_VISIBLE | FS_USERNS_MOUNT, see fs/proc/root.c.
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func (*filesystem) Flags() fs.FilesystemFlags {
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return 0
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}
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// Mount returns the root of a procfs that can be positioned in the vfs.
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2019-05-15 03:33:44 +00:00
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func (f *filesystem) Mount(ctx context.Context, device string, flags fs.MountSourceFlags, data string, cgroupsInt interface{}) (*fs.Inode, error) {
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2018-04-27 17:37:02 +00:00
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// device is always ignored.
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// Parse generic comma-separated key=value options, this file system expects them.
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options := fs.GenericMountSourceOptions(data)
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// Proc options parsing checks for either a gid= or hidepid= and barfs on
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// anything else, see fs/proc/root.c:proc_parse_options. Since we don't know
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// what to do with gid= or hidepid=, we blow up if we get any options.
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if len(options) > 0 {
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return nil, fmt.Errorf("unsupported mount options: %v", options)
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}
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2019-05-15 03:33:44 +00:00
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var cgroups map[string]string
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if cgroupsInt != nil {
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cgroups = cgroupsInt.(map[string]string)
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}
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2018-04-27 17:37:02 +00:00
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// Construct the procfs root. Since procfs files are all virtual, we
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// never want them cached.
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2019-06-14 01:39:43 +00:00
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return New(ctx, fs.NewNonCachingMountSource(ctx, f, flags), cgroups)
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2018-04-27 17:37:02 +00:00
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}
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