mirror of
https://github.com/moby/moby.git
synced 2022-11-09 12:21:53 -05:00
553 lines
14 KiB
Go
553 lines
14 KiB
Go
// +build linux
|
|
|
|
package ipvs
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/binary"
|
|
"fmt"
|
|
"net"
|
|
"os/exec"
|
|
"strings"
|
|
"sync"
|
|
"sync/atomic"
|
|
"syscall"
|
|
"unsafe"
|
|
|
|
"github.com/sirupsen/logrus"
|
|
"github.com/vishvananda/netlink/nl"
|
|
"github.com/vishvananda/netns"
|
|
)
|
|
|
|
// For Quick Reference IPVS related netlink message is described at the end of this file.
|
|
var (
|
|
native = nl.NativeEndian()
|
|
ipvsFamily int
|
|
ipvsOnce sync.Once
|
|
)
|
|
|
|
type genlMsgHdr struct {
|
|
cmd uint8
|
|
version uint8
|
|
reserved uint16
|
|
}
|
|
|
|
type ipvsFlags struct {
|
|
flags uint32
|
|
mask uint32
|
|
}
|
|
|
|
func deserializeGenlMsg(b []byte) (hdr *genlMsgHdr) {
|
|
return (*genlMsgHdr)(unsafe.Pointer(&b[0:unsafe.Sizeof(*hdr)][0]))
|
|
}
|
|
|
|
func (hdr *genlMsgHdr) Serialize() []byte {
|
|
return (*(*[unsafe.Sizeof(*hdr)]byte)(unsafe.Pointer(hdr)))[:]
|
|
}
|
|
|
|
func (hdr *genlMsgHdr) Len() int {
|
|
return int(unsafe.Sizeof(*hdr))
|
|
}
|
|
|
|
func (f *ipvsFlags) Serialize() []byte {
|
|
return (*(*[unsafe.Sizeof(*f)]byte)(unsafe.Pointer(f)))[:]
|
|
}
|
|
|
|
func (f *ipvsFlags) Len() int {
|
|
return int(unsafe.Sizeof(*f))
|
|
}
|
|
|
|
func setup() {
|
|
ipvsOnce.Do(func() {
|
|
var err error
|
|
if out, err := exec.Command("modprobe", "-va", "ip_vs").CombinedOutput(); err != nil {
|
|
logrus.Warnf("Running modprobe ip_vs failed with message: `%s`, error: %v", strings.TrimSpace(string(out)), err)
|
|
}
|
|
|
|
ipvsFamily, err = getIPVSFamily()
|
|
if err != nil {
|
|
logrus.Error("Could not get ipvs family information from the kernel. It is possible that ipvs is not enabled in your kernel. Native loadbalancing will not work until this is fixed.")
|
|
}
|
|
})
|
|
}
|
|
|
|
func fillService(s *Service) nl.NetlinkRequestData {
|
|
cmdAttr := nl.NewRtAttr(ipvsCmdAttrService, nil)
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrAddressFamily, nl.Uint16Attr(s.AddressFamily))
|
|
if s.FWMark != 0 {
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrFWMark, nl.Uint32Attr(s.FWMark))
|
|
} else {
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrProtocol, nl.Uint16Attr(s.Protocol))
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrAddress, rawIPData(s.Address))
|
|
|
|
// Port needs to be in network byte order.
|
|
portBuf := new(bytes.Buffer)
|
|
binary.Write(portBuf, binary.BigEndian, s.Port)
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrPort, portBuf.Bytes())
|
|
}
|
|
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrSchedName, nl.ZeroTerminated(s.SchedName))
|
|
if s.PEName != "" {
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrPEName, nl.ZeroTerminated(s.PEName))
|
|
}
|
|
f := &ipvsFlags{
|
|
flags: s.Flags,
|
|
mask: 0xFFFFFFFF,
|
|
}
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrFlags, f.Serialize())
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrTimeout, nl.Uint32Attr(s.Timeout))
|
|
nl.NewRtAttrChild(cmdAttr, ipvsSvcAttrNetmask, nl.Uint32Attr(s.Netmask))
|
|
return cmdAttr
|
|
}
|
|
|
|
func fillDestinaton(d *Destination) nl.NetlinkRequestData {
|
|
cmdAttr := nl.NewRtAttr(ipvsCmdAttrDest, nil)
|
|
|
|
nl.NewRtAttrChild(cmdAttr, ipvsDestAttrAddress, rawIPData(d.Address))
|
|
// Port needs to be in network byte order.
|
|
portBuf := new(bytes.Buffer)
|
|
binary.Write(portBuf, binary.BigEndian, d.Port)
|
|
nl.NewRtAttrChild(cmdAttr, ipvsDestAttrPort, portBuf.Bytes())
|
|
|
|
nl.NewRtAttrChild(cmdAttr, ipvsDestAttrForwardingMethod, nl.Uint32Attr(d.ConnectionFlags&ConnectionFlagFwdMask))
|
|
nl.NewRtAttrChild(cmdAttr, ipvsDestAttrWeight, nl.Uint32Attr(uint32(d.Weight)))
|
|
nl.NewRtAttrChild(cmdAttr, ipvsDestAttrUpperThreshold, nl.Uint32Attr(d.UpperThreshold))
|
|
nl.NewRtAttrChild(cmdAttr, ipvsDestAttrLowerThreshold, nl.Uint32Attr(d.LowerThreshold))
|
|
|
|
return cmdAttr
|
|
}
|
|
|
|
func (i *Handle) doCmdwithResponse(s *Service, d *Destination, cmd uint8) ([][]byte, error) {
|
|
req := newIPVSRequest(cmd)
|
|
req.Seq = atomic.AddUint32(&i.seq, 1)
|
|
|
|
if s == nil {
|
|
req.Flags |= syscall.NLM_F_DUMP //Flag to dump all messages
|
|
req.AddData(nl.NewRtAttr(ipvsCmdAttrService, nil)) //Add a dummy attribute
|
|
} else {
|
|
req.AddData(fillService(s))
|
|
}
|
|
|
|
if d == nil {
|
|
if cmd == ipvsCmdGetDest {
|
|
req.Flags |= syscall.NLM_F_DUMP
|
|
}
|
|
|
|
} else {
|
|
req.AddData(fillDestinaton(d))
|
|
}
|
|
|
|
res, err := execute(i.sock, req, 0)
|
|
if err != nil {
|
|
return [][]byte{}, err
|
|
}
|
|
|
|
return res, nil
|
|
}
|
|
|
|
func (i *Handle) doCmd(s *Service, d *Destination, cmd uint8) error {
|
|
_, err := i.doCmdwithResponse(s, d, cmd)
|
|
|
|
return err
|
|
}
|
|
|
|
func getIPVSFamily() (int, error) {
|
|
sock, err := nl.GetNetlinkSocketAt(netns.None(), netns.None(), syscall.NETLINK_GENERIC)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
defer sock.Close()
|
|
|
|
req := newGenlRequest(genlCtrlID, genlCtrlCmdGetFamily)
|
|
req.AddData(nl.NewRtAttr(genlCtrlAttrFamilyName, nl.ZeroTerminated("IPVS")))
|
|
|
|
msgs, err := execute(sock, req, 0)
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
for _, m := range msgs {
|
|
hdr := deserializeGenlMsg(m)
|
|
attrs, err := nl.ParseRouteAttr(m[hdr.Len():])
|
|
if err != nil {
|
|
return 0, err
|
|
}
|
|
|
|
for _, attr := range attrs {
|
|
switch int(attr.Attr.Type) {
|
|
case genlCtrlAttrFamilyID:
|
|
return int(native.Uint16(attr.Value[0:2])), nil
|
|
}
|
|
}
|
|
}
|
|
|
|
return 0, fmt.Errorf("no family id in the netlink response")
|
|
}
|
|
|
|
func rawIPData(ip net.IP) []byte {
|
|
family := nl.GetIPFamily(ip)
|
|
if family == nl.FAMILY_V4 {
|
|
return ip.To4()
|
|
}
|
|
return ip
|
|
}
|
|
|
|
func newIPVSRequest(cmd uint8) *nl.NetlinkRequest {
|
|
return newGenlRequest(ipvsFamily, cmd)
|
|
}
|
|
|
|
func newGenlRequest(familyID int, cmd uint8) *nl.NetlinkRequest {
|
|
req := nl.NewNetlinkRequest(familyID, syscall.NLM_F_ACK)
|
|
req.AddData(&genlMsgHdr{cmd: cmd, version: 1})
|
|
return req
|
|
}
|
|
|
|
func execute(s *nl.NetlinkSocket, req *nl.NetlinkRequest, resType uint16) ([][]byte, error) {
|
|
var (
|
|
err error
|
|
)
|
|
|
|
if err := s.Send(req); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
pid, err := s.GetPid()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
var res [][]byte
|
|
|
|
done:
|
|
for {
|
|
msgs, err := s.Receive()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
for _, m := range msgs {
|
|
if m.Header.Seq != req.Seq {
|
|
continue
|
|
}
|
|
if m.Header.Pid != pid {
|
|
return nil, fmt.Errorf("Wrong pid %d, expected %d", m.Header.Pid, pid)
|
|
}
|
|
if m.Header.Type == syscall.NLMSG_DONE {
|
|
break done
|
|
}
|
|
if m.Header.Type == syscall.NLMSG_ERROR {
|
|
error := int32(native.Uint32(m.Data[0:4]))
|
|
if error == 0 {
|
|
break done
|
|
}
|
|
return nil, syscall.Errno(-error)
|
|
}
|
|
if resType != 0 && m.Header.Type != resType {
|
|
continue
|
|
}
|
|
res = append(res, m.Data)
|
|
if m.Header.Flags&syscall.NLM_F_MULTI == 0 {
|
|
break done
|
|
}
|
|
}
|
|
}
|
|
return res, nil
|
|
}
|
|
|
|
func parseIP(ip []byte, family uint16) (net.IP, error) {
|
|
|
|
var resIP net.IP
|
|
|
|
switch family {
|
|
case syscall.AF_INET:
|
|
resIP = (net.IP)(ip[:4])
|
|
case syscall.AF_INET6:
|
|
resIP = (net.IP)(ip[:16])
|
|
default:
|
|
return nil, fmt.Errorf("parseIP Error ip=%v", ip)
|
|
|
|
}
|
|
return resIP, nil
|
|
}
|
|
|
|
// parseStats
|
|
func assembleStats(msg []byte) (SvcStats, error) {
|
|
|
|
var s SvcStats
|
|
|
|
attrs, err := nl.ParseRouteAttr(msg)
|
|
if err != nil {
|
|
return s, err
|
|
}
|
|
|
|
for _, attr := range attrs {
|
|
attrType := int(attr.Attr.Type)
|
|
switch attrType {
|
|
case ipvsSvcStatsConns:
|
|
s.Connections = native.Uint32(attr.Value)
|
|
case ipvsSvcStatsPktsIn:
|
|
s.PacketsIn = native.Uint32(attr.Value)
|
|
case ipvsSvcStatsPktsOut:
|
|
s.PacketsOut = native.Uint32(attr.Value)
|
|
case ipvsSvcStatsBytesIn:
|
|
s.BytesIn = native.Uint64(attr.Value)
|
|
case ipvsSvcStatsBytesOut:
|
|
s.BytesOut = native.Uint64(attr.Value)
|
|
case ipvsSvcStatsCPS:
|
|
s.CPS = native.Uint32(attr.Value)
|
|
case ipvsSvcStatsPPSIn:
|
|
s.PPSIn = native.Uint32(attr.Value)
|
|
case ipvsSvcStatsPPSOut:
|
|
s.PPSOut = native.Uint32(attr.Value)
|
|
case ipvsSvcStatsBPSIn:
|
|
s.BPSIn = native.Uint32(attr.Value)
|
|
case ipvsSvcStatsBPSOut:
|
|
s.BPSOut = native.Uint32(attr.Value)
|
|
}
|
|
}
|
|
return s, nil
|
|
}
|
|
|
|
// assembleService assembles a services back from a hain of netlink attributes
|
|
func assembleService(attrs []syscall.NetlinkRouteAttr) (*Service, error) {
|
|
|
|
var s Service
|
|
|
|
for _, attr := range attrs {
|
|
|
|
attrType := int(attr.Attr.Type)
|
|
|
|
switch attrType {
|
|
|
|
case ipvsSvcAttrAddressFamily:
|
|
s.AddressFamily = native.Uint16(attr.Value)
|
|
case ipvsSvcAttrProtocol:
|
|
s.Protocol = native.Uint16(attr.Value)
|
|
case ipvsSvcAttrAddress:
|
|
ip, err := parseIP(attr.Value, s.AddressFamily)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
s.Address = ip
|
|
case ipvsSvcAttrPort:
|
|
s.Port = binary.BigEndian.Uint16(attr.Value)
|
|
case ipvsSvcAttrFWMark:
|
|
s.FWMark = native.Uint32(attr.Value)
|
|
case ipvsSvcAttrSchedName:
|
|
s.SchedName = nl.BytesToString(attr.Value)
|
|
case ipvsSvcAttrFlags:
|
|
s.Flags = native.Uint32(attr.Value)
|
|
case ipvsSvcAttrTimeout:
|
|
s.Timeout = native.Uint32(attr.Value)
|
|
case ipvsSvcAttrNetmask:
|
|
s.Netmask = native.Uint32(attr.Value)
|
|
case ipvsSvcAttrStats:
|
|
stats, err := assembleStats(attr.Value)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
s.Stats = stats
|
|
}
|
|
|
|
}
|
|
return &s, nil
|
|
}
|
|
|
|
// parseService given a ipvs netlink response this function will respond with a valid service entry, an error otherwise
|
|
func (i *Handle) parseService(msg []byte) (*Service, error) {
|
|
|
|
var s *Service
|
|
|
|
//Remove General header for this message and parse the NetLink message
|
|
hdr := deserializeGenlMsg(msg)
|
|
NetLinkAttrs, err := nl.ParseRouteAttr(msg[hdr.Len():])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if len(NetLinkAttrs) == 0 {
|
|
return nil, fmt.Errorf("error no valid netlink message found while parsing service record")
|
|
}
|
|
|
|
//Now Parse and get IPVS related attributes messages packed in this message.
|
|
ipvsAttrs, err := nl.ParseRouteAttr(NetLinkAttrs[0].Value)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
//Assemble all the IPVS related attribute messages and create a service record
|
|
s, err = assembleService(ipvsAttrs)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return s, nil
|
|
}
|
|
|
|
// doGetServicesCmd a wrapper which could be used commonly for both GetServices() and GetService(*Service)
|
|
func (i *Handle) doGetServicesCmd(svc *Service) ([]*Service, error) {
|
|
var res []*Service
|
|
|
|
msgs, err := i.doCmdwithResponse(svc, nil, ipvsCmdGetService)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
for _, msg := range msgs {
|
|
srv, err := i.parseService(msg)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
res = append(res, srv)
|
|
}
|
|
|
|
return res, nil
|
|
}
|
|
|
|
// doCmdWithoutAttr a simple wrapper of netlink socket execute command
|
|
func (i *Handle) doCmdWithoutAttr(cmd uint8) ([][]byte, error) {
|
|
req := newIPVSRequest(cmd)
|
|
req.Seq = atomic.AddUint32(&i.seq, 1)
|
|
return execute(i.sock, req, 0)
|
|
}
|
|
|
|
func assembleDestination(attrs []syscall.NetlinkRouteAttr) (*Destination, error) {
|
|
|
|
var d Destination
|
|
|
|
for _, attr := range attrs {
|
|
|
|
attrType := int(attr.Attr.Type)
|
|
|
|
switch attrType {
|
|
case ipvsDestAttrAddress:
|
|
ip, err := parseIP(attr.Value, syscall.AF_INET)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
d.Address = ip
|
|
case ipvsDestAttrPort:
|
|
d.Port = binary.BigEndian.Uint16(attr.Value)
|
|
case ipvsDestAttrForwardingMethod:
|
|
d.ConnectionFlags = native.Uint32(attr.Value)
|
|
case ipvsDestAttrWeight:
|
|
d.Weight = int(native.Uint16(attr.Value))
|
|
case ipvsDestAttrUpperThreshold:
|
|
d.UpperThreshold = native.Uint32(attr.Value)
|
|
case ipvsDestAttrLowerThreshold:
|
|
d.LowerThreshold = native.Uint32(attr.Value)
|
|
case ipvsDestAttrAddressFamily:
|
|
d.AddressFamily = native.Uint16(attr.Value)
|
|
}
|
|
}
|
|
return &d, nil
|
|
}
|
|
|
|
// parseDestination given a ipvs netlink response this function will respond with a valid destination entry, an error otherwise
|
|
func (i *Handle) parseDestination(msg []byte) (*Destination, error) {
|
|
var dst *Destination
|
|
|
|
//Remove General header for this message
|
|
hdr := deserializeGenlMsg(msg)
|
|
NetLinkAttrs, err := nl.ParseRouteAttr(msg[hdr.Len():])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if len(NetLinkAttrs) == 0 {
|
|
return nil, fmt.Errorf("error no valid netlink message found while parsing destination record")
|
|
}
|
|
|
|
//Now Parse and get IPVS related attributes messages packed in this message.
|
|
ipvsAttrs, err := nl.ParseRouteAttr(NetLinkAttrs[0].Value)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
//Assemble netlink attributes and create a Destination record
|
|
dst, err = assembleDestination(ipvsAttrs)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return dst, nil
|
|
}
|
|
|
|
// doGetDestinationsCmd a wrapper function to be used by GetDestinations and GetDestination(d) apis
|
|
func (i *Handle) doGetDestinationsCmd(s *Service, d *Destination) ([]*Destination, error) {
|
|
|
|
var res []*Destination
|
|
|
|
msgs, err := i.doCmdwithResponse(s, d, ipvsCmdGetDest)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
for _, msg := range msgs {
|
|
dest, err := i.parseDestination(msg)
|
|
if err != nil {
|
|
return res, err
|
|
}
|
|
res = append(res, dest)
|
|
}
|
|
return res, nil
|
|
}
|
|
|
|
// IPVS related netlink message format explained
|
|
|
|
/* EACH NETLINK MSG is of the below format, this is what we will receive from execute() api.
|
|
If we have multiple netlink objects to process like GetServices() etc., execute() will
|
|
supply an array of this below object
|
|
|
|
NETLINK MSG
|
|
|-----------------------------------|
|
|
0 1 2 3
|
|
|--------|--------|--------|--------| -
|
|
| CMD ID | VER | RESERVED | |==> General Message Header represented by genlMsgHdr
|
|
|-----------------------------------| -
|
|
| ATTR LEN | ATTR TYPE | |
|
|
|-----------------------------------| |
|
|
| | |
|
|
| VALUE | |
|
|
| []byte Array of IPVS MSG | |==> Attribute Message represented by syscall.NetlinkRouteAttr
|
|
| PADDED BY 4 BYTES | |
|
|
| | |
|
|
|-----------------------------------| -
|
|
|
|
|
|
Once We strip genlMsgHdr from above NETLINK MSG, we should parse the VALUE.
|
|
VALUE will have an array of netlink attributes (syscall.NetlinkRouteAttr) such that each attribute will
|
|
represent a "Service" or "Destination" object's field. If we assemble these attributes we can construct
|
|
Service or Destination.
|
|
|
|
IPVS MSG
|
|
|-----------------------------------|
|
|
0 1 2 3
|
|
|--------|--------|--------|--------|
|
|
| ATTR LEN | ATTR TYPE |
|
|
|-----------------------------------|
|
|
| |
|
|
| |
|
|
| []byte IPVS ATTRIBUTE BY 4 BYTES |
|
|
| |
|
|
| |
|
|
|-----------------------------------|
|
|
NEXT ATTRIBUTE
|
|
|-----------------------------------|
|
|
| ATTR LEN | ATTR TYPE |
|
|
|-----------------------------------|
|
|
| |
|
|
| |
|
|
| []byte IPVS ATTRIBUTE BY 4 BYTES |
|
|
| |
|
|
| |
|
|
|-----------------------------------|
|
|
NEXT ATTRIBUTE
|
|
|-----------------------------------|
|
|
| ATTR LEN | ATTR TYPE |
|
|
|-----------------------------------|
|
|
| |
|
|
| |
|
|
| []byte IPVS ATTRIBUTE BY 4 BYTES |
|
|
| |
|
|
| |
|
|
|-----------------------------------|
|
|
|
|
*/
|