forked from vishvananda/netlink
-
Notifications
You must be signed in to change notification settings - Fork 0
/
socket_linux.go
318 lines (287 loc) · 7.4 KB
/
socket_linux.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
package netlink
import (
"errors"
"fmt"
"net"
"syscall"
"github.com/vishvananda/netlink/nl"
"golang.org/x/sys/unix"
)
const (
sizeofSocketID = 0x30
sizeofSocketRequest = sizeofSocketID + 0x8
sizeofSocket = sizeofSocketID + 0x18
)
type socketRequest struct {
Family uint8
Protocol uint8
Ext uint8
pad uint8
States uint32
ID SocketID
}
type writeBuffer struct {
Bytes []byte
pos int
}
func (b *writeBuffer) Write(c byte) {
b.Bytes[b.pos] = c
b.pos++
}
func (b *writeBuffer) Next(n int) []byte {
s := b.Bytes[b.pos : b.pos+n]
b.pos += n
return s
}
func (r *socketRequest) Serialize() []byte {
b := writeBuffer{Bytes: make([]byte, sizeofSocketRequest)}
b.Write(r.Family)
b.Write(r.Protocol)
b.Write(r.Ext)
b.Write(r.pad)
native.PutUint32(b.Next(4), r.States)
networkOrder.PutUint16(b.Next(2), r.ID.SourcePort)
networkOrder.PutUint16(b.Next(2), r.ID.DestinationPort)
if r.Family == unix.AF_INET6 {
copy(b.Next(16), r.ID.Source)
copy(b.Next(16), r.ID.Destination)
} else {
copy(b.Next(16), r.ID.Source.To4())
copy(b.Next(16), r.ID.Destination.To4())
}
native.PutUint32(b.Next(4), r.ID.Interface)
native.PutUint32(b.Next(4), r.ID.Cookie[0])
native.PutUint32(b.Next(4), r.ID.Cookie[1])
return b.Bytes
}
func (r *socketRequest) Len() int { return sizeofSocketRequest }
type readBuffer struct {
Bytes []byte
pos int
}
func (b *readBuffer) Read() byte {
c := b.Bytes[b.pos]
b.pos++
return c
}
func (b *readBuffer) Next(n int) []byte {
s := b.Bytes[b.pos : b.pos+n]
b.pos += n
return s
}
func (s *Socket) deserialize(b []byte) error {
if len(b) < sizeofSocket {
return fmt.Errorf("socket data short read (%d); want %d", len(b), sizeofSocket)
}
rb := readBuffer{Bytes: b}
s.Family = rb.Read()
s.State = rb.Read()
s.Timer = rb.Read()
s.Retrans = rb.Read()
s.ID.SourcePort = networkOrder.Uint16(rb.Next(2))
s.ID.DestinationPort = networkOrder.Uint16(rb.Next(2))
if s.Family == unix.AF_INET6 {
s.ID.Source = net.IP(rb.Next(16))
s.ID.Destination = net.IP(rb.Next(16))
} else {
s.ID.Source = net.IPv4(rb.Read(), rb.Read(), rb.Read(), rb.Read())
rb.Next(12)
s.ID.Destination = net.IPv4(rb.Read(), rb.Read(), rb.Read(), rb.Read())
rb.Next(12)
}
s.ID.Interface = native.Uint32(rb.Next(4))
s.ID.Cookie[0] = native.Uint32(rb.Next(4))
s.ID.Cookie[1] = native.Uint32(rb.Next(4))
s.Expires = native.Uint32(rb.Next(4))
s.RQueue = native.Uint32(rb.Next(4))
s.WQueue = native.Uint32(rb.Next(4))
s.UID = native.Uint32(rb.Next(4))
s.INode = native.Uint32(rb.Next(4))
return nil
}
// SocketGet returns the Socket identified by its local and remote addresses.
func SocketGet(local, remote net.Addr) (*Socket, error) {
var protocol uint8
var localIP, remoteIP net.IP
var localPort, remotePort uint16
switch l := local.(type) {
case *net.TCPAddr:
r, ok := remote.(*net.TCPAddr)
if !ok {
return nil, ErrNotImplemented
}
localIP = l.IP
localPort = uint16(l.Port)
remoteIP = r.IP
remotePort = uint16(r.Port)
protocol = unix.IPPROTO_TCP
case *net.UDPAddr:
r, ok := remote.(*net.UDPAddr)
if !ok {
return nil, ErrNotImplemented
}
localIP = l.IP
localPort = uint16(l.Port)
remoteIP = r.IP
remotePort = uint16(r.Port)
protocol = unix.IPPROTO_UDP
default:
return nil, ErrNotImplemented
}
var family uint8
if localIP.To4() != nil && remoteIP.To4() != nil {
family = unix.AF_INET
}
if family == 0 && localIP.To16() != nil && remoteIP.To16() != nil {
family = unix.AF_INET6
}
if family == 0 {
return nil, ErrNotImplemented
}
s, err := nl.Subscribe(unix.NETLINK_INET_DIAG)
if err != nil {
return nil, err
}
defer s.Close()
req := nl.NewNetlinkRequest(nl.SOCK_DIAG_BY_FAMILY, unix.NLM_F_DUMP)
req.AddData(&socketRequest{
Family: family,
Protocol: protocol,
States: 0xffffffff,
ID: SocketID{
SourcePort: localPort,
DestinationPort: remotePort,
Source: localIP,
Destination: remoteIP,
Cookie: [2]uint32{nl.TCPDIAG_NOCOOKIE, nl.TCPDIAG_NOCOOKIE},
},
})
if err := s.Send(req); err != nil {
return nil, err
}
msgs, from, err := s.Receive()
if err != nil {
return nil, err
}
if from.Pid != nl.PidKernel {
return nil, fmt.Errorf("Wrong sender portid %d, expected %d", from.Pid, nl.PidKernel)
}
if len(msgs) == 0 {
return nil, errors.New("no message nor error from netlink")
}
if len(msgs) > 2 {
return nil, fmt.Errorf("multiple (%d) matching sockets", len(msgs))
}
sock := &Socket{}
if err := sock.deserialize(msgs[0].Data); err != nil {
return nil, err
}
return sock, nil
}
// SocketDiagTCPInfo requests INET_DIAG_INFO for TCP protocol for specified family type and return with extension TCP info.
func SocketDiagTCPInfo(family uint8) ([]*InetDiagTCPInfoResp, error) {
var result []*InetDiagTCPInfoResp
err := socketDiagTCPExecutor(family, 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 := attrsToInetDiagTCPInfoResp(attrs, sockInfo)
if err != nil {
return err
}
result = append(result, res)
return nil
})
if err != nil {
return nil, err
}
return result, nil
}
// SocketDiagTCP requests INET_DIAG_INFO for TCP protocol for specified family type and return related socket.
func SocketDiagTCP(family uint8) ([]*Socket, error) {
var result []*Socket
err := socketDiagTCPExecutor(family, 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
}
// 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)
if err != nil {
return err
}
defer s.Close()
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 TCP states
})
s.Send(req)
loop:
for {
msgs, from, err := s.Receive()
if err != nil {
return err
}
if 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")
}
for _, m := range msgs {
switch m.Header.Type {
case unix.NLMSG_DONE:
break loop
case unix.NLMSG_ERROR:
error := int32(native.Uint32(m.Data[0:4]))
return syscall.Errno(-error)
}
if err := receiver(m); err != nil {
return err
}
}
}
return nil
}
func attrsToInetDiagTCPInfoResp(attrs []syscall.NetlinkRouteAttr, sockInfo *Socket) (*InetDiagTCPInfoResp, error) {
var tcpInfo *TCPInfo
var tcpBBRInfo *TCPBBRInfo
for _, a := range attrs {
if a.Attr.Type == INET_DIAG_INFO {
tcpInfo = &TCPInfo{}
if err := tcpInfo.deserialize(a.Value); err != nil {
return nil, err
}
continue
}
if a.Attr.Type == INET_DIAG_BBRINFO {
tcpBBRInfo = &TCPBBRInfo{}
if err := tcpBBRInfo.deserialize(a.Value); err != nil {
return nil, err
}
continue
}
}
return &InetDiagTCPInfoResp{
InetDiagMsg: sockInfo,
TCPInfo: tcpInfo,
TCPBBRInfo: tcpBBRInfo,
}, nil
}