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authorkevin.xu <cming.xu@gmail.com>2020-04-27 21:51:31 +0800
committerGitHub <noreply@github.com>2020-04-27 21:51:31 +0800
commite896ca54db67524afc20b644d43c72185e72dc0e (patch)
tree2a16f3a62a5cafd098f1f028c621f1b655589d69 /pkg/sentry/fsimpl/sys/sys.go
parent1f19624fa127d7d59cabe29593cc80b7fe6c81f8 (diff)
parent3c67754663f424f2ebbc0ff2a4c80e30618d5355 (diff)
Merge pull request #1 from google/master
catch up
Diffstat (limited to 'pkg/sentry/fsimpl/sys/sys.go')
-rw-r--r--pkg/sentry/fsimpl/sys/sys.go134
1 files changed, 134 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/sys/sys.go b/pkg/sentry/fsimpl/sys/sys.go
new file mode 100644
index 000000000..f8d25d35e
--- /dev/null
+++ b/pkg/sentry/fsimpl/sys/sys.go
@@ -0,0 +1,134 @@
+// Copyright 2019 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 sys implements sysfs.
+package sys
+
+import (
+ "bytes"
+ "fmt"
+
+ "gvisor.dev/gvisor/pkg/abi/linux"
+ "gvisor.dev/gvisor/pkg/context"
+ "gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
+ "gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/auth"
+ "gvisor.dev/gvisor/pkg/sentry/vfs"
+ "gvisor.dev/gvisor/pkg/syserror"
+)
+
+// Name is the default filesystem name.
+const Name = "sysfs"
+
+// FilesystemType implements vfs.FilesystemType.
+type FilesystemType struct{}
+
+// filesystem implements vfs.FilesystemImpl.
+type filesystem struct {
+ kernfs.Filesystem
+}
+
+// Name implements vfs.FilesystemType.Name.
+func (FilesystemType) Name() string {
+ return Name
+}
+
+// GetFilesystem implements vfs.FilesystemType.GetFilesystem.
+func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, source string, opts vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) {
+ fs := &filesystem{}
+ fs.Filesystem.Init(vfsObj, &fsType)
+ k := kernel.KernelFromContext(ctx)
+ maxCPUCores := k.ApplicationCores()
+ defaultSysDirMode := linux.FileMode(0755)
+
+ root := fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{
+ "block": fs.newDir(creds, defaultSysDirMode, nil),
+ "bus": fs.newDir(creds, defaultSysDirMode, nil),
+ "class": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{
+ "power_supply": fs.newDir(creds, defaultSysDirMode, nil),
+ }),
+ "dev": fs.newDir(creds, defaultSysDirMode, nil),
+ "devices": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{
+ "system": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{
+ "cpu": fs.newDir(creds, defaultSysDirMode, map[string]*kernfs.Dentry{
+ "online": fs.newCPUFile(creds, maxCPUCores, linux.FileMode(0444)),
+ "possible": fs.newCPUFile(creds, maxCPUCores, linux.FileMode(0444)),
+ "present": fs.newCPUFile(creds, maxCPUCores, linux.FileMode(0444)),
+ }),
+ }),
+ }),
+ "firmware": fs.newDir(creds, defaultSysDirMode, nil),
+ "fs": fs.newDir(creds, defaultSysDirMode, nil),
+ "kernel": fs.newDir(creds, defaultSysDirMode, nil),
+ "module": fs.newDir(creds, defaultSysDirMode, nil),
+ "power": fs.newDir(creds, defaultSysDirMode, nil),
+ })
+ return fs.VFSFilesystem(), root.VFSDentry(), nil
+}
+
+// dir implements kernfs.Inode.
+type dir struct {
+ kernfs.InodeAttrs
+ kernfs.InodeNoDynamicLookup
+ kernfs.InodeNotSymlink
+ kernfs.InodeDirectoryNoNewChildren
+
+ kernfs.OrderedChildren
+ dentry kernfs.Dentry
+}
+
+func (fs *filesystem) newDir(creds *auth.Credentials, mode linux.FileMode, contents map[string]*kernfs.Dentry) *kernfs.Dentry {
+ d := &dir{}
+ d.InodeAttrs.Init(creds, fs.NextIno(), linux.ModeDirectory|0755)
+ d.OrderedChildren.Init(kernfs.OrderedChildrenOptions{})
+ d.dentry.Init(d)
+
+ d.IncLinks(d.OrderedChildren.Populate(&d.dentry, contents))
+
+ return &d.dentry
+}
+
+// SetStat implements Inode.SetStat not allowing inode attributes to be changed.
+func (*dir) SetStat(context.Context, *vfs.Filesystem, *auth.Credentials, vfs.SetStatOptions) error {
+ return syserror.EPERM
+}
+
+// Open implements kernfs.Inode.Open.
+func (d *dir) Open(ctx context.Context, rp *vfs.ResolvingPath, vfsd *vfs.Dentry, opts vfs.OpenOptions) (*vfs.FileDescription, error) {
+ fd, err := kernfs.NewGenericDirectoryFD(rp.Mount(), vfsd, &d.OrderedChildren, &opts)
+ if err != nil {
+ return nil, err
+ }
+ return fd.VFSFileDescription(), nil
+}
+
+// cpuFile implements kernfs.Inode.
+type cpuFile struct {
+ kernfs.DynamicBytesFile
+ maxCores uint
+}
+
+// Generate implements vfs.DynamicBytesSource.Generate.
+func (c *cpuFile) Generate(ctx context.Context, buf *bytes.Buffer) error {
+ fmt.Fprintf(buf, "0-%d", c.maxCores-1)
+ return nil
+}
+
+func (fs *filesystem) newCPUFile(creds *auth.Credentials, maxCores uint, mode linux.FileMode) *kernfs.Dentry {
+ c := &cpuFile{maxCores: maxCores}
+ c.DynamicBytesFile.Init(creds, fs.NextIno(), c, mode)
+ d := &kernfs.Dentry{}
+ d.Init(c)
+ return d
+}