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// Copyright (c) 2019 Cisco and/or its affiliates.
//
// 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 statsclient
import (
"fmt"
"net"
"sync/atomic"
"syscall"
"time"
"unsafe"
"github.com/ftrvxmtrx/fd"
"git.fd.io/govpp.git/adapter"
)
var (
maxWaitInProgress = time.Second * 1
)
type statSegDirectoryEntry struct {
directoryType statDirectoryType
// unionData can represent: offset, index or value
unionData uint64
offsetVector uint64
name [128]byte
}
type statDirectoryType int32
func (t statDirectoryType) String() string {
return adapter.StatType(t).String()
}
type statSegment struct {
sharedHeader []byte
memorySize int64
oldHeader bool
}
func (c *statSegment) connect(sockName string) error {
addr := &net.UnixAddr{
Net: "unixpacket",
Name: sockName,
}
Log.Debugf("connecting to: %v", addr)
conn, err := net.DialUnix(addr.Net, nil, addr)
if err != nil {
Log.Warnf("connecting to socket %s failed: %s", addr, err)
return err
}
defer func() {
if err := conn.Close(); err != nil {
Log.Warnf("closing socket failed: %v", err)
}
}()
Log.Debugf("connected to socket")
files, err := fd.Get(conn, 1, nil)
if err != nil {
return fmt.Errorf("getting file descriptor over socket failed: %v", err)
}
if len(files) == 0 {
return fmt.Errorf("no files received over socket")
}
defer func() {
for _, f := range files {
if err := f.Close(); err != nil {
Log.Warnf("closing file %s failed: %v", f.Name(), err)
}
}
}()
Log.Debugf("received %d files over socket", len(files))
f := files[0]
info, err := f.Stat()
if err != nil {
return err
}
size := info.Size()
Log.Debugf("fd: name=%v size=%v", info.Name(), size)
data, err := syscall.Mmap(int(f.Fd()), 0, int(size), syscall.PROT_READ, syscall.MAP_SHARED)
if err != nil {
Log.Warnf("mapping shared memory failed: %v", err)
return fmt.Errorf("mapping shared memory failed: %v", err)
}
Log.Debugf("successfuly mapped shared memory")
c.sharedHeader = data
c.memorySize = size
header := c.readHeader()
Log.Debugf("stat segment header: %+v", header)
// older VPP (19.04) did not have version in stat segment header
// we try to provide fallback support by skipping it in header
if header.version > MaxVersion && header.inProgress > 1 && header.epoch == 0 {
h := c.readHeaderOld()
Log.Warnf("falling back to old stat segment header version: %+v", h)
c.oldHeader = true
}
return nil
}
func (c *statSegment) disconnect() error {
if err := syscall.Munmap(c.sharedHeader); err != nil {
Log.Warnf("unmapping shared memory failed: %v", err)
return fmt.Errorf("unmapping shared memory failed: %v", err)
}
Log.Debugf("successfuly unmapped shared memory")
return nil
}
type sharedHeaderBase struct {
epoch int64
inProgress int64
directoryOffset int64
errorOffset int64
statsOffset int64
}
type statSegSharedHeader struct {
version uint64
sharedHeaderBase
}
func (c *statSegment) readHeaderOld() (header statSegSharedHeader) {
h := (*sharedHeaderBase)(unsafe.Pointer(&c.sharedHeader[0]))
header.version = 0
header.epoch = atomic.LoadInt64(&h.epoch)
header.inProgress = atomic.LoadInt64(&h.inProgress)
header.directoryOffset = atomic.LoadInt64(&h.directoryOffset)
header.errorOffset = atomic.LoadInt64(&h.errorOffset)
header.statsOffset = atomic.LoadInt64(&h.statsOffset)
return
}
func (c *statSegment) readHeader() (header statSegSharedHeader) {
h := (*statSegSharedHeader)(unsafe.Pointer(&c.sharedHeader[0]))
header.version = atomic.LoadUint64(&h.version)
header.epoch = atomic.LoadInt64(&h.epoch)
header.inProgress = atomic.LoadInt64(&h.inProgress)
header.directoryOffset = atomic.LoadInt64(&h.directoryOffset)
header.errorOffset = atomic.LoadInt64(&h.errorOffset)
header.statsOffset = atomic.LoadInt64(&h.statsOffset)
return
}
func (c *statSegment) readVersion() uint64 {
if c.oldHeader {
return 0
}
header := (*statSegSharedHeader)(unsafe.Pointer(&c.sharedHeader[0]))
version := atomic.LoadUint64(&header.version)
return version
}
func (c *statSegment) readEpoch() (int64, bool) {
if c.oldHeader {
h := c.readHeaderOld()
return h.epoch, h.inProgress != 0
}
header := (*statSegSharedHeader)(unsafe.Pointer(&c.sharedHeader[0]))
epoch := atomic.LoadInt64(&header.epoch)
inprog := atomic.LoadInt64(&header.inProgress)
return epoch, inprog != 0
}
func (c *statSegment) readOffsets() (dir, err, stat int64) {
if c.oldHeader {
h := c.readHeaderOld()
return h.directoryOffset, h.errorOffset, h.statsOffset
}
header := (*statSegSharedHeader)(unsafe.Pointer(&c.sharedHeader[0]))
dirOffset := atomic.LoadInt64(&header.directoryOffset)
errOffset := atomic.LoadInt64(&header.errorOffset)
statOffset := atomic.LoadInt64(&header.statsOffset)
return dirOffset, errOffset, statOffset
}
type statSegAccess struct {
epoch int64
}
func (c *statSegment) accessStart() *statSegAccess {
epoch, inprog := c.readEpoch()
t := time.Now()
for inprog {
if time.Since(t) > maxWaitInProgress {
return nil
}
epoch, inprog = c.readEpoch()
}
return &statSegAccess{
epoch: epoch,
}
}
func (c *statSegment) accessEnd(acc *statSegAccess) bool {
epoch, inprog := c.readEpoch()
if acc.epoch != epoch || inprog {
return false
}
return true
}
type vecHeader struct {
length uint64
vectorData [0]uint8
}
func vectorLen(v unsafe.Pointer) uint64 {
vec := *(*vecHeader)(unsafe.Pointer(uintptr(v) - unsafe.Sizeof(uintptr(0))))
return vec.length
}
//go:nosplit
func add(p unsafe.Pointer, x uintptr) unsafe.Pointer {
return unsafe.Pointer(uintptr(p) + x)
}
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