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// Copyright 2018 Google Inc.
//
// 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 proc
import (
"fmt"
"io"
"gvisor.googlesource.com/gvisor/pkg/sentry/context"
"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
"gvisor.googlesource.com/gvisor/pkg/sentry/fs/proc/device"
"gvisor.googlesource.com/gvisor/pkg/sentry/fs/ramfs"
"gvisor.googlesource.com/gvisor/pkg/sentry/inet"
"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
)
type tcpMemDir int
const (
tcpRMem tcpMemDir = iota
tcpWMem
)
type tcpMem struct {
ramfs.Entry
s inet.Stack
size inet.TCPBufferSize
dir tcpMemDir
}
func newTCPMem(s inet.Stack, size inet.TCPBufferSize, dir tcpMemDir) *tcpMem {
return &tcpMem{s: s, size: size, dir: dir}
}
func newTCPMemInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack, size inet.TCPBufferSize, dir tcpMemDir) *fs.Inode {
tm := newTCPMem(s, size, dir)
tm.InitEntry(ctx, fs.RootOwner, fs.FilePermsFromMode(0644))
sattr := fs.StableAttr{
DeviceID: device.ProcDevice.DeviceID(),
InodeID: device.ProcDevice.NextIno(),
BlockSize: usermem.PageSize,
Type: fs.SpecialFile,
}
return fs.NewInode(tm, msrc, sattr)
}
// DeprecatedPreadv implements fs.InodeOperations.DeprecatedPreadv.
func (m *tcpMem) DeprecatedPreadv(ctx context.Context, dst usermem.IOSequence, offset int64) (int64, error) {
if offset != 0 {
return 0, io.EOF
}
s := fmt.Sprintf("%d\t%d\t%d\n", m.size.Min, m.size.Default, m.size.Max)
n, err := dst.CopyOut(ctx, []byte(s))
return int64(n), err
}
// Truncate implements fs.InodeOperations.Truncate.
func (*tcpMem) Truncate(context.Context, *fs.Inode, int64) error {
return nil
}
// DeprecatedPwritev implements fs.InodeOperations.DeprecatedPwritev.
func (m *tcpMem) DeprecatedPwritev(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) {
if src.NumBytes() == 0 {
return 0, nil
}
src = src.TakeFirst(usermem.PageSize - 1)
buf := []int32{int32(m.size.Min), int32(m.size.Default), int32(m.size.Max)}
n, cperr := usermem.CopyInt32StringsInVec(ctx, src.IO, src.Addrs, buf, src.Opts)
size := inet.TCPBufferSize{
Min: int(buf[0]),
Default: int(buf[1]),
Max: int(buf[2]),
}
var err error
switch m.dir {
case tcpRMem:
err = m.s.SetTCPReceiveBufferSize(size)
case tcpWMem:
err = m.s.SetTCPSendBufferSize(size)
default:
panic(fmt.Sprintf("unknown tcpMem.dir: %v", m.dir))
}
if err != nil {
return n, err
}
return n, cperr
}
type tcpSack struct {
ramfs.Entry
s inet.Stack `state:"nosave"` // S/R-FIXME
}
func newTCPSackInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *fs.Inode {
ts := &tcpSack{s: s}
ts.InitEntry(ctx, fs.RootOwner, fs.FilePermsFromMode(0644))
sattr := fs.StableAttr{
DeviceID: device.ProcDevice.DeviceID(),
InodeID: device.ProcDevice.NextIno(),
BlockSize: usermem.PageSize,
Type: fs.SpecialFile,
}
return fs.NewInode(ts, msrc, sattr)
}
func (s *tcpSack) DeprecatedPreadv(ctx context.Context, dst usermem.IOSequence, offset int64) (int64, error) {
if offset != 0 {
return 0, io.EOF
}
sack, err := s.s.TCPSACKEnabled()
if err != nil {
return 0, err
}
val := "0\n"
if sack {
// Technically, this is not quite compatible with Linux. Linux
// stores these as an integer, so if you write "2" into
// tcp_sack, you should get 2 back. Tough luck.
val = "1\n"
}
n, err := dst.CopyOut(ctx, []byte(val))
return int64(n), err
}
// Truncate implements fs.InodeOperations.Truncate.
func (*tcpSack) Truncate(context.Context, *fs.Inode, int64) error {
return nil
}
// DeprecatedPwritev implements fs.InodeOperations.DeprecatedPwritev.
func (s *tcpSack) DeprecatedPwritev(ctx context.Context, src usermem.IOSequence, offset int64) (int64, error) {
if src.NumBytes() == 0 {
return 0, nil
}
src = src.TakeFirst(usermem.PageSize - 1)
var v int32
n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts)
if err != nil {
return n, err
}
return n, s.s.SetTCPSACKEnabled(v != 0)
}
func newSysNetIPv4Dir(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *fs.Inode {
d := &ramfs.Dir{}
d.InitDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0555))
// Add tcp_rmem.
if rs, err := s.TCPReceiveBufferSize(); err == nil {
d.AddChild(ctx, "tcp_rmem", newTCPMemInode(ctx, msrc, s, rs, tcpRMem))
}
// Add tcp_wmem.
if ss, err := s.TCPSendBufferSize(); err == nil {
d.AddChild(ctx, "tcp_wmem", newTCPMemInode(ctx, msrc, s, ss, tcpWMem))
}
// Add tcp_sack.
d.AddChild(ctx, "tcp_sack", newTCPSackInode(ctx, msrc, s))
return newFile(d, msrc, fs.SpecialDirectory, nil)
}
func (p *proc) newSysNetDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
d := &ramfs.Dir{}
d.InitDir(ctx, nil, fs.RootOwner, fs.FilePermsFromMode(0555))
if s := p.k.NetworkStack(); s != nil {
d.AddChild(ctx, "ipv4", newSysNetIPv4Dir(ctx, msrc, s))
}
return newFile(d, msrc, fs.SpecialDirectory, nil)
}
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