126 lines
3.9 KiB
Go
126 lines
3.9 KiB
Go
// Copyright 2018 Google Inc.
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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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"io"
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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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"gvisor.googlesource.com/gvisor/pkg/sentry/fs/proc/seqfile"
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"gvisor.googlesource.com/gvisor/pkg/sentry/fs/ramfs"
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"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
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"gvisor.googlesource.com/gvisor/pkg/sentry/socket/rpcinet"
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"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
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)
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// hostname is a file containing the system hostname.
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type hostname struct {
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ramfs.Entry
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}
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// DeprecatedPreadv implements fs.InodeOperations.DeprecatedPreadv.
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func (hostname) DeprecatedPreadv(ctx context.Context, dst usermem.IOSequence, offset int64) (int64, error) {
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utsns := kernel.UTSNamespaceFromContext(ctx)
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contents := []byte(utsns.HostName() + "\n")
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if offset >= int64(len(contents)) {
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return 0, io.EOF
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}
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n, err := dst.CopyOut(ctx, contents[offset:])
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return int64(n), err
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}
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func (p *proc) newHostname(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
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h := &hostname{}
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h.InitEntry(ctx, fs.RootOwner, fs.FilePermsFromMode(0444))
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return newFile(h, msrc, fs.SpecialFile, nil)
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}
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// mmapMinAddrData backs /proc/sys/vm/mmap_min_addr.
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type mmapMinAddrData struct {
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k *kernel.Kernel
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}
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// NeedsUpdate implements seqfile.SeqSource.NeedsUpdate.
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func (*mmapMinAddrData) NeedsUpdate(generation int64) bool {
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return true
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}
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// ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData.
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func (d *mmapMinAddrData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) {
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if h != nil {
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return nil, 0
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}
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return []seqfile.SeqData{
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{
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Buf: []byte(fmt.Sprintf("%d\n", d.k.Platform.MinUserAddress())),
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Handle: (*mmapMinAddrData)(nil),
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},
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}, 0
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}
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type overcommitMemory struct{}
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func (*overcommitMemory) NeedsUpdate(generation int64) bool {
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return true
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}
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// ReadSeqFileData implements seqfile.SeqSource.
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func (*overcommitMemory) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) {
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if h != nil {
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return nil, 0
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}
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return []seqfile.SeqData{
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{
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Buf: []byte("0\n"),
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Handle: (*overcommitMemory)(nil),
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},
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}, 0
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}
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func (p *proc) newKernelDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
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d := &ramfs.Dir{}
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d.InitDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0555))
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d.AddChild(ctx, "hostname", p.newHostname(ctx, msrc))
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return newFile(d, msrc, fs.SpecialDirectory, nil)
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}
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func (p *proc) newVMDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
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d := &ramfs.Dir{}
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d.InitDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0555))
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d.AddChild(ctx, "mmap_min_addr", seqfile.NewSeqFileInode(ctx, &mmapMinAddrData{p.k}, msrc))
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d.AddChild(ctx, "overcommit_memory", seqfile.NewSeqFileInode(ctx, &overcommitMemory{}, msrc))
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return newFile(d, msrc, fs.SpecialDirectory, nil)
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}
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func (p *proc) newSysDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
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d := &ramfs.Dir{}
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d.InitDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0555))
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d.AddChild(ctx, "kernel", p.newKernelDir(ctx, msrc))
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d.AddChild(ctx, "vm", p.newVMDir(ctx, msrc))
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// If we're using rpcinet we will let it manage /proc/sys/net.
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if _, ok := p.k.NetworkStack().(*rpcinet.Stack); ok {
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d.AddChild(ctx, "net", newRPCInetProcSysNet(ctx, msrc))
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} else {
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d.AddChild(ctx, "net", p.newSysNetDir(ctx, msrc))
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}
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return newFile(d, msrc, fs.SpecialDirectory, nil)
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}
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