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Implement UDP socket diagnostics
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Signed-off-by: Sven Rebhan <[email protected]>
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srebhan committed Dec 8, 2023
1 parent 0ced838 commit f085c72
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Showing 7 changed files with 194 additions and 68 deletions.
1 change: 1 addition & 0 deletions go.mod
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@ module github.com/vishvananda/netlink
go 1.12

require (
github.com/stretchr/testify v1.8.4
github.com/vishvananda/netns v0.0.0-20200728191858-db3c7e526aae
golang.org/x/sys v0.10.0
)
17 changes: 17 additions & 0 deletions go.sum
Original file line number Diff line number Diff line change
@@ -1,5 +1,22 @@
github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
github.com/vishvananda/netns v0.0.0-20200728191858-db3c7e526aae h1:4hwBBUfQCFe3Cym0ZtKyq7L16eZUtYKs+BaHDN6mAns=
github.com/vishvananda/netns v0.0.0-20200728191858-db3c7e526aae/go.mod h1:DD4vA1DwXk04H54A1oHXtwZmA0grkVMdPxx/VGLCah0=
golang.org/x/sys v0.0.0-20200217220822-9197077df867/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
golang.org/x/sys v0.10.0 h1:SqMFp9UcQJZa+pmYuAKjd9xq1f0j5rLcDIk0mj4qAsA=
golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
5 changes: 5 additions & 0 deletions inet_diag.go
Original file line number Diff line number Diff line change
Expand Up @@ -29,3 +29,8 @@ type InetDiagTCPInfoResp struct {
TCPInfo *TCPInfo
TCPBBRInfo *TCPBBRInfo
}

type InetDiagUDPInfoResp struct {
InetDiagMsg *Socket
Memory *MemInfo
}
142 changes: 117 additions & 25 deletions socket_linux.go
Original file line number Diff line number Diff line change
Expand Up @@ -174,8 +174,18 @@ func SocketGet(local, remote net.Addr) (*Socket, error) {

// SocketDiagTCPInfo requests INET_DIAG_INFO for TCP protocol for specified family type and return with extension TCP info.
func SocketDiagTCPInfo(family uint8) ([]*InetDiagTCPInfoResp, error) {
// Construct the request
req := nl.NewNetlinkRequest(nl.SOCK_DIAG_BY_FAMILY, unix.NLM_F_DUMP)
req.AddData(&socketRequest{
Family: family,
Protocol: unix.IPPROTO_TCP,
Ext: (1 << (INET_DIAG_VEGASINFO - 1)) | (1 << (INET_DIAG_INFO - 1)),
States: uint32(0xfff), // all states
})

// Do the query and parse the result
var result []*InetDiagTCPInfoResp
err := socketDiagTCPExecutor(family, func(m syscall.NetlinkMessage) error {
err := socketDiagExecutor(req, func(m syscall.NetlinkMessage) error {
sockInfo := &Socket{}
if err := sockInfo.deserialize(m.Data); err != nil {
return err
Expand All @@ -201,8 +211,18 @@ func SocketDiagTCPInfo(family uint8) ([]*InetDiagTCPInfoResp, error) {

// SocketDiagTCP requests INET_DIAG_INFO for TCP protocol for specified family type and return related socket.
func SocketDiagTCP(family uint8) ([]*Socket, error) {
// Construct the request
req := nl.NewNetlinkRequest(nl.SOCK_DIAG_BY_FAMILY, unix.NLM_F_DUMP)
req.AddData(&socketRequest{
Family: family,
Protocol: unix.IPPROTO_TCP,
Ext: (1 << (INET_DIAG_VEGASINFO - 1)) | (1 << (INET_DIAG_INFO - 1)),
States: uint32(0xfff), // all states
})

// Do the query and parse the result
var result []*Socket
err := socketDiagTCPExecutor(family, func(m syscall.NetlinkMessage) error {
err := socketDiagExecutor(req, func(m syscall.NetlinkMessage) error {
sockInfo := &Socket{}
if err := sockInfo.deserialize(m.Data); err != nil {
return err
Expand All @@ -216,21 +236,82 @@ func SocketDiagTCP(family uint8) ([]*Socket, error) {
return result, nil
}

// socketDiagTCPExecutor requests INET_DIAG_INFO for TCP protocol for specified family type.
func socketDiagTCPExecutor(family uint8, receiver func(syscall.NetlinkMessage) error) error {
s, err := nl.Subscribe(unix.NETLINK_INET_DIAG)
// SocketDiagUDPInfo requests INET_DIAG_INFO for UDP protocol for specified family type and return with extension info.
func SocketDiagUDPInfo(family uint8) ([]*InetDiagUDPInfoResp, error) {
// Construct the request
var extensions uint8
extensions = 1 << (INET_DIAG_VEGASINFO - 1)
extensions |= 1 << (INET_DIAG_INFO - 1)
extensions |= 1 << (INET_DIAG_MEMINFO - 1)

req := nl.NewNetlinkRequest(nl.SOCK_DIAG_BY_FAMILY, unix.NLM_F_DUMP)
req.AddData(&socketRequest{
Family: family,
Protocol: unix.IPPROTO_UDP,
Ext: extensions,
States: uint32(0xfff), // all states
})

// Do the query and parse the result
var result []*InetDiagUDPInfoResp
err := socketDiagExecutor(req, func(m syscall.NetlinkMessage) error {
sockInfo := &Socket{}
if err := sockInfo.deserialize(m.Data); err != nil {
return err
}
attrs, err := nl.ParseRouteAttr(m.Data[sizeofSocket:])
if err != nil {
return err
}

res, err := attrsToInetDiagUDPInfoResp(attrs, sockInfo)
if err != nil {
return err
}

result = append(result, res)
return nil
})
if err != nil {
return err
return nil, err
}
defer s.Close()
return result, nil
}

// SocketDiagUDP requests INET_DIAG_INFO for UDP protocol for specified family type and return related socket.
func SocketDiagUDP(family uint8) ([]*Socket, error) {
// Construct the request
req := nl.NewNetlinkRequest(nl.SOCK_DIAG_BY_FAMILY, unix.NLM_F_DUMP)
req.AddData(&socketRequest{
Family: family,
Protocol: unix.IPPROTO_TCP,
Protocol: unix.IPPROTO_UDP,
Ext: (1 << (INET_DIAG_VEGASINFO - 1)) | (1 << (INET_DIAG_INFO - 1)),
States: uint32(0xfff), // All TCP states
States: uint32(0xfff), // all states
})

// Do the query and parse the result
var result []*Socket
err := socketDiagExecutor(req, func(m syscall.NetlinkMessage) error {
sockInfo := &Socket{}
if err := sockInfo.deserialize(m.Data); err != nil {
return err
}
result = append(result, sockInfo)
return nil
})
if err != nil {
return nil, err
}
return result, nil
}

// socketDiagExecutor requests diagnoses info from the NETLINK_INET_DIAG socket for the specified request.
func socketDiagExecutor(req *nl.NetlinkRequest, receiver func(syscall.NetlinkMessage) error) error {
s, err := nl.Subscribe(unix.NETLINK_INET_DIAG)
if err != nil {
return err
}
defer s.Close()
s.Send(req)

loop:
Expand All @@ -240,7 +321,7 @@ loop:
return err
}
if from.Pid != nl.PidKernel {
return fmt.Errorf("Wrong sender portid %d, expected %d", from.Pid, nl.PidKernel)
return fmt.Errorf("wrong sender portid %d, expected %d", from.Pid, nl.PidKernel)
}
if len(msgs) == 0 {
return errors.New("no message nor error from netlink")
Expand All @@ -263,29 +344,40 @@ loop:
}

func attrsToInetDiagTCPInfoResp(attrs []syscall.NetlinkRouteAttr, sockInfo *Socket) (*InetDiagTCPInfoResp, error) {
var tcpInfo *TCPInfo
var tcpBBRInfo *TCPBBRInfo
info := &InetDiagTCPInfoResp{
InetDiagMsg: sockInfo,
}
for _, a := range attrs {
if a.Attr.Type == INET_DIAG_INFO {
tcpInfo = &TCPInfo{}
if err := tcpInfo.deserialize(a.Value); err != nil {
switch a.Attr.Type {
case INET_DIAG_INFO:
info.TCPInfo = &TCPInfo{}
if err := info.TCPInfo.deserialize(a.Value); err != nil {
return nil, err
}
case INET_DIAG_BBRINFO:
info.TCPBBRInfo = &TCPBBRInfo{}
if err := info.TCPBBRInfo.deserialize(a.Value); err != nil {
return nil, err
}
continue
}
}

return info, nil
}

if a.Attr.Type == INET_DIAG_BBRINFO {
tcpBBRInfo = &TCPBBRInfo{}
if err := tcpBBRInfo.deserialize(a.Value); err != nil {
func attrsToInetDiagUDPInfoResp(attrs []syscall.NetlinkRouteAttr, sockInfo *Socket) (*InetDiagUDPInfoResp, error) {
info := &InetDiagUDPInfoResp{
InetDiagMsg: sockInfo,
}
for _, a := range attrs {
switch a.Attr.Type {
case INET_DIAG_MEMINFO:
info.Memory = &MemInfo{}
if err := info.Memory.deserialize(a.Value); err != nil {
return nil, err
}
continue
}
}

return &InetDiagTCPInfoResp{
InetDiagMsg: sockInfo,
TCPInfo: tcpInfo,
TCPBBRInfo: tcpBBRInfo,
}, nil
return info, nil
}
74 changes: 31 additions & 43 deletions socket_test.go
Original file line number Diff line number Diff line change
@@ -1,77 +1,65 @@
//go:build linux
// +build linux

package netlink

import (
"log"
"net"
"os/user"
"strconv"
"syscall"
"testing"

"github.com/stretchr/testify/require"
)

func TestSocketGet(t *testing.T) {
defer setUpNetlinkTestWithLoopback(t)()

addr, err := net.ResolveTCPAddr("tcp", "localhost:0")
if err != nil {
log.Fatal(err)
}
require.NoError(t, err)

l, err := net.ListenTCP("tcp", addr)
if err != nil {
log.Fatal(err)
}
require.NoError(t, err)
defer l.Close()

conn, err := net.Dial(l.Addr().Network(), l.Addr().String())
if err != nil {
t.Fatal(err)
}
require.NoError(t, err)
defer conn.Close()

localAddr := conn.LocalAddr().(*net.TCPAddr)
remoteAddr := conn.RemoteAddr().(*net.TCPAddr)
socket, err := SocketGet(localAddr, remoteAddr)
if err != nil {
t.Fatal(err)
}
require.NoError(t, err)

require.EqualValues(t, localAddr.IP, socket.ID.Source, "local ip")
require.EqualValues(t, remoteAddr.IP, socket.ID.Destination, "remote ip")
require.EqualValues(t, localAddr.Port, socket.ID.SourcePort, "local port")
require.EqualValues(t, remoteAddr.Port, socket.ID.DestinationPort, "remote port")

if got, want := socket.ID.Source, localAddr.IP; !got.Equal(want) {
t.Fatalf("local ip = %v, want %v", got, want)
}
if got, want := socket.ID.Destination, remoteAddr.IP; !got.Equal(want) {
t.Fatalf("remote ip = %v, want %v", got, want)
}
if got, want := int(socket.ID.SourcePort), localAddr.Port; got != want {
t.Fatalf("local port = %d, want %d", got, want)
}
if got, want := int(socket.ID.DestinationPort), remoteAddr.Port; got != want {
t.Fatalf("remote port = %d, want %d", got, want)
}
u, err := user.Current()
if err != nil {
t.Fatal(err)
}
if got, want := strconv.Itoa(int(socket.UID)), u.Uid; got != want {
t.Fatalf("UID = %s, want %s", got, want)
}
require.NoError(t, err)
require.EqualValues(t, u.Uid, strconv.Itoa(int(socket.UID)), "UID")
}

func TestSocketDiagTCPInfo(t *testing.T) {
Family4 := uint8(syscall.AF_INET)
Family6 := uint8(syscall.AF_INET6)
families := []uint8{Family4, Family6}
for _, wantFamily := range families {
res, err := SocketDiagTCPInfo(wantFamily)
if err != nil {
t.Fatal(err)
for _, expected := range []uint8{syscall.AF_INET, syscall.AF_INET6} {
result, err := SocketDiagTCPInfo(expected)
require.NoError(t, err)

for _, i := range result {
require.Equal(t, expected, i.InetDiagMsg.Family)
}
for _, i := range res {
gotFamily := i.InetDiagMsg.Family
if gotFamily != wantFamily {
t.Fatalf("Socket family = %d, want %d", gotFamily, wantFamily)
}
}
}

func TestSocketDiagUDPnfo(t *testing.T) {
for _, expected := range []uint8{syscall.AF_INET, syscall.AF_INET6} {
result, err := SocketDiagUDPInfo(expected)
require.NoError(t, err)

for _, i := range result {
require.Equal(t, expected, i.InetDiagMsg.Family)
}
}
}
8 changes: 8 additions & 0 deletions tcp.go
Original file line number Diff line number Diff line change
Expand Up @@ -82,3 +82,11 @@ type TCPBBRInfo struct {
BBRPacingGain uint32
BBRCwndGain uint32
}

// According to https://man7.org/linux/man-pages/man7/sock_diag.7.html
type MemInfo struct {
RMem uint32
WMem uint32
FMem uint32
TMem uint32
}
15 changes: 15 additions & 0 deletions tcp_linux.go
Original file line number Diff line number Diff line change
Expand Up @@ -8,6 +8,7 @@ import (

const (
tcpBBRInfoLen = 20
memInfoLen = 16
)

func checkDeserErr(err error) error {
Expand Down Expand Up @@ -351,3 +352,17 @@ func (t *TCPBBRInfo) deserialize(b []byte) error {

return nil
}

func (m *MemInfo) deserialize(b []byte) error {
if len(b) != memInfoLen {
return errors.New("Invalid length")
}

rb := bytes.NewBuffer(b)
m.RMem = native.Uint32(rb.Next(4))
m.WMem = native.Uint32(rb.Next(4))
m.FMem = native.Uint32(rb.Next(4))
m.TMem = native.Uint32(rb.Next(4))

return nil
}

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