mirror of
https://github.com/soypat/lneto.git
synced 2026-08-12 10:53:44 +00:00
soypat
924 lines
34 KiB
Go
924 lines
34 KiB
Go
package tcp_test
|
|
|
|
import (
|
|
"math/rand"
|
|
"strconv"
|
|
"testing"
|
|
|
|
"github.com/soypat/lneto"
|
|
"github.com/soypat/lneto/ethernet"
|
|
"github.com/soypat/lneto/ipv4"
|
|
"github.com/soypat/lneto/tcp"
|
|
)
|
|
|
|
const (
|
|
SYNACK = tcp.FlagSYN | tcp.FlagACK
|
|
FINACK = tcp.FlagFIN | tcp.FlagACK
|
|
PSHACK = tcp.FlagPSH | tcp.FlagACK
|
|
)
|
|
|
|
/*
|
|
Section 3.5 of RFC 9293: Basic 3-way handshake for connection synchronization.
|
|
TCP Peer A TCP Peer B
|
|
|
|
1. CLOSED LISTEN
|
|
|
|
2. SYN-SENT --> <SEQ=100><CTL=SYN> --> SYN-RECEIVED
|
|
|
|
3. ESTABLISHED <-- <SEQ=300><ACK=101><CTL=SYN,ACK> <-- SYN-RECEIVED
|
|
|
|
4. ESTABLISHED --> <SEQ=101><ACK=301><CTL=ACK> --> ESTABLISHED
|
|
|
|
5. ESTABLISHED --> <SEQ=101><ACK=301><CTL=ACK><DATA> --> ESTABLISHED
|
|
*/
|
|
func TestExchange_rfc9293_figure6(t *testing.T) {
|
|
const issA, issB, windowA, windowB = 100, 300, 1000, 1000
|
|
exchangeA := []tcp.Exchange{
|
|
{ // A sends SYN to B.
|
|
Outgoing: &tcp.Segment{SEQ: issA, Flags: tcp.FlagSYN, WND: windowA},
|
|
WantState: tcp.StateSynSent,
|
|
WantPeerState: tcp.StateSynRcvd,
|
|
},
|
|
{ // A receives SYNACK from B thus establishing the connection on A's side.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: issA + 1, Flags: SYNACK, WND: windowB},
|
|
WantState: tcp.StateEstablished,
|
|
WantPending: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantPeerState: tcp.StateSynRcvd,
|
|
},
|
|
{ // A sends ACK to B, which leaves connection established on their side. Three way handshake complete by now.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantState: tcp.StateEstablished,
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
}
|
|
var tcbA tcp.ControlBlock
|
|
tcbA.HelperInitState(tcp.StateSynSent, issA, issA, windowA)
|
|
tcbA.HelperExchange(t, exchangeA)
|
|
segA, ok := tcbA.PendingSegment(0)
|
|
if ok {
|
|
t.Error("unexpected Client pending segment after establishment: ", segA)
|
|
}
|
|
exchangeB := reverseExchange(exchangeA)
|
|
|
|
var tcbB tcp.ControlBlock
|
|
tcbB.HelperInitState(tcp.StateListen, issB, issB, windowB)
|
|
tcbB.HelperExchange(t, exchangeB) // TODO remove [:3] after snd.UNA bugfix
|
|
segB, ok := tcbB.PendingSegment(0)
|
|
if ok {
|
|
t.Error("unexpected Listener pending segment after establishment: ", segB)
|
|
}
|
|
}
|
|
|
|
/*
|
|
Section 3.5 of RFC 9293: Simultaneous Connection Synchronization (SYN).
|
|
TCP Peer A TCP Peer B
|
|
|
|
1. CLOSED CLOSED
|
|
|
|
2. SYN-SENT --> <SEQ=100><CTL=SYN> ...
|
|
|
|
3. SYN-RECEIVED <-- <SEQ=300><CTL=SYN> <-- SYN-SENT
|
|
|
|
4. ... <SEQ=100><CTL=SYN> --> SYN-RECEIVED
|
|
|
|
5. SYN-RECEIVED --> <SEQ=100><ACK=301><CTL=SYN,ACK> ...
|
|
|
|
6. ESTABLISHED <-- <SEQ=300><ACK=101><CTL=SYN,ACK> <-- SYN-RECEIVED
|
|
|
|
7. ... <SEQ=100><ACK=301><CTL=SYN,ACK> --> ESTABLISHED
|
|
*/
|
|
func TestExchange_rfc9293_figure7(t *testing.T) {
|
|
const issA, issB, windowA, windowB = 100, 300, 1000, 1000
|
|
exchangeA := []tcp.Exchange{
|
|
0: { // A sends SYN to B.
|
|
Outgoing: &tcp.Segment{SEQ: issA, Flags: tcp.FlagSYN, WND: windowA},
|
|
WantState: tcp.StateSynSent,
|
|
},
|
|
1: { // A receives a SYN with no ACK from B.
|
|
Incoming: &tcp.Segment{SEQ: issB, Flags: tcp.FlagSYN, WND: windowB},
|
|
WantState: tcp.StateSynRcvd,
|
|
WantPending: &tcp.Segment{SEQ: issA, ACK: issB + 1, Flags: SYNACK, WND: windowA},
|
|
},
|
|
2: { // A sends SYNACK to B.
|
|
Outgoing: &tcp.Segment{SEQ: issA, ACK: issB + 1, Flags: SYNACK, WND: windowA},
|
|
WantState: tcp.StateSynRcvd,
|
|
},
|
|
3: { // A receives ACK from B.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: issA + 1, Flags: SYNACK, WND: windowA},
|
|
WantState: tcp.StateEstablished,
|
|
},
|
|
}
|
|
var tcbA tcp.ControlBlock
|
|
tcbA.HelperInitState(tcp.StateSynSent, issA, issA, windowA)
|
|
tcbA.HelperExchange(t, exchangeA)
|
|
}
|
|
|
|
/*
|
|
Recovery from Old Duplicate SYN
|
|
TCP Peer A TCP Peer B
|
|
|
|
1. CLOSED LISTEN
|
|
|
|
2. SYN-SENT --> <SEQ=100><CTL=SYN> ...
|
|
|
|
3. (duplicate) ... <SEQ=90><CTL=SYN> --> SYN-RECEIVED
|
|
|
|
4. SYN-SENT <-- <SEQ=300><ACK=91><CTL=SYN,ACK> <-- SYN-RECEIVED
|
|
|
|
5. SYN-SENT --> <SEQ=91><CTL=RST> --> LISTEN
|
|
|
|
6. ... <SEQ=100><CTL=SYN> --> SYN-RECEIVED
|
|
|
|
7. ESTABLISHED <-- <SEQ=400><ACK=101><CTL=SYN,ACK> <-- SYN-RECEIVED
|
|
|
|
8. ESTABLISHED --> <SEQ=101><ACK=401><CTL=ACK> --> ESTABLISHED
|
|
*/
|
|
func TestExchange_rfc9293_figure8(t *testing.T) {
|
|
const issA, issB, windowA, windowB = 100, 300, 1000, 1000
|
|
const issAold = 90
|
|
const issBNew = issB + 100
|
|
exchangeA := []tcp.Exchange{
|
|
0: { // A sends new SYN to B (which is not received).
|
|
Outgoing: &tcp.Segment{SEQ: issA, Flags: tcp.FlagSYN, WND: windowA},
|
|
WantState: tcp.StateSynSent,
|
|
WantPeerState: tcp.StateSynRcvd,
|
|
},
|
|
1: { // Receive SYN from B acking an old "duplicate" SYN.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: issAold + 1, Flags: SYNACK, WND: windowB},
|
|
WantState: tcp.StateSynSent,
|
|
WantPending: &tcp.Segment{SEQ: issAold + 1, Flags: tcp.FlagRST, WND: windowA},
|
|
WantPeerState: tcp.StateSynRcvd,
|
|
},
|
|
2: { // A sends RST to B and makes segment believable by using the old SEQ.
|
|
Outgoing: &tcp.Segment{SEQ: issAold + 1, Flags: tcp.FlagRST, WND: windowA},
|
|
WantState: tcp.StateSynSent,
|
|
WantPeerState: tcp.StateListen,
|
|
},
|
|
3: { // A sends a duplicate SYN to B.
|
|
Outgoing: &tcp.Segment{SEQ: issA, Flags: tcp.FlagSYN, WND: windowA},
|
|
WantState: tcp.StateSynSent,
|
|
WantPeerState: tcp.StateSynRcvd,
|
|
},
|
|
4: { // B SYNACKs new SYN.
|
|
Incoming: &tcp.Segment{SEQ: issBNew, ACK: issA + 1, Flags: SYNACK, WND: windowB},
|
|
WantState: tcp.StateEstablished,
|
|
WantPending: &tcp.Segment{SEQ: issA + 1, ACK: issBNew + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantPeerState: tcp.StateSynRcvd,
|
|
},
|
|
5: { // B receives ACK from A.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1, ACK: issBNew + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantState: tcp.StateEstablished,
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
}
|
|
var tcbA tcp.ControlBlock
|
|
tcbA.HelperInitState(tcp.StateSynSent, issA, issA, windowA)
|
|
tcbA.HelperExchange(t, exchangeA)
|
|
|
|
exchangeB := []tcp.Exchange{
|
|
0: { // B receives old SYN from A.
|
|
Incoming: &tcp.Segment{SEQ: issAold, Flags: tcp.FlagSYN, WND: windowA},
|
|
WantState: tcp.StateSynRcvd,
|
|
WantPending: &tcp.Segment{SEQ: issB, ACK: issAold + 1, Flags: SYNACK, WND: windowB},
|
|
},
|
|
1: { // B SYNACKs old SYN.
|
|
Outgoing: &tcp.Segment{SEQ: issB, ACK: issAold + 1, Flags: SYNACK, WND: windowB},
|
|
WantState: tcp.StateSynRcvd,
|
|
},
|
|
2: { // B receives RST from A.
|
|
Incoming: &tcp.Segment{SEQ: issAold + 1, Flags: tcp.FlagRST, WND: windowA},
|
|
WantState: tcp.StateListen,
|
|
},
|
|
3: { // B receives new SYN from A.
|
|
Incoming: &tcp.Segment{SEQ: issA, Flags: tcp.FlagSYN, WND: windowA},
|
|
WantState: tcp.StateSynRcvd,
|
|
WantPending: &tcp.Segment{SEQ: issBNew, ACK: issA + 1, Flags: SYNACK, WND: windowB},
|
|
},
|
|
4: { // B SYNACKs new SYN.
|
|
Outgoing: &tcp.Segment{SEQ: issBNew, ACK: issA + 1, Flags: SYNACK, WND: windowB},
|
|
WantState: tcp.StateSynRcvd,
|
|
},
|
|
5: { // B receives ACK from A.
|
|
Incoming: &tcp.Segment{SEQ: issA + 1, ACK: issBNew + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantState: tcp.StateEstablished,
|
|
},
|
|
}
|
|
var tcbB tcp.ControlBlock
|
|
tcbB.HelperInitState(tcp.StateListen, issB, issB, windowB)
|
|
tcbB.HelperExchange(t, exchangeB)
|
|
}
|
|
|
|
/*
|
|
Figure 12: Normal Close Sequence
|
|
TCP Peer A TCP Peer B
|
|
1. ESTABLISHED ESTABLISHED
|
|
|
|
2. (Close)
|
|
FIN-WAIT-1 --> <SEQ=100><ACK=300><CTL=FIN,ACK> --> CLOSE-WAIT
|
|
|
|
3. FIN-WAIT-2 <-- <SEQ=300><ACK=101><CTL=ACK> <-- CLOSE-WAIT
|
|
|
|
4. (Close)
|
|
TIME-WAIT <-- <SEQ=300><ACK=101><CTL=FIN,ACK> <-- LAST-ACK
|
|
|
|
5. TIME-WAIT --> <SEQ=101><ACK=301><CTL=ACK> --> CLOSED
|
|
|
|
6. (2 MSL)
|
|
CLOSED
|
|
*/
|
|
func TestExchange_rfc9293_figure12(t *testing.T) {
|
|
const issA, issB, windowA, windowB = 100, 300, 1000, 1000
|
|
exchangeA := []tcp.Exchange{
|
|
0: { // A sends FIN|ACK to B to begin closing connection.
|
|
Outgoing: &tcp.Segment{SEQ: issA, ACK: issB, Flags: FINACK, WND: windowA},
|
|
WantState: tcp.StateFinWait1,
|
|
WantPeerState: tcp.StateCloseWait,
|
|
},
|
|
1: { // A receives ACK from B.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: issA + 1, Flags: tcp.FlagACK, WND: windowB},
|
|
WantState: tcp.StateFinWait2,
|
|
WantPeerState: tcp.StateCloseWait,
|
|
// TODO(soypat): WantPending should be nil here? Perhaps fix test by modifying rcvFinWait1 pending result.
|
|
WantPending: &tcp.Segment{SEQ: issA + 1, ACK: issB, Flags: tcp.FlagACK, WND: windowA},
|
|
},
|
|
2: { // A receives FIN|ACK from B.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: issA + 1, Flags: FINACK, WND: windowB},
|
|
WantState: tcp.StateTimeWait,
|
|
WantPending: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantPeerState: tcp.StateLastAck,
|
|
},
|
|
3: { // A sends ACK to B.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantState: tcp.StateTimeWait, // Technically we should be in TimeWait here.
|
|
WantPeerState: tcp.StateClosed,
|
|
},
|
|
}
|
|
var tcbA tcp.ControlBlock
|
|
tcbA.HelperInitState(tcp.StateEstablished, issA, issA, windowA)
|
|
tcbA.HelperInitRcv(issB, issB, windowB)
|
|
tcbA.HelperExchange(t, exchangeA)
|
|
// tcbA.HelperExchange(t, exchangeA[:1])
|
|
// tcbA.HelperExchange(t, exchangeA[1:2])
|
|
// tcbA.HelperExchange(t, exchangeA[2:])
|
|
|
|
return
|
|
exchangeB := reverseExchange(exchangeA)
|
|
exchangeB[1].WantPending = &tcp.Segment{SEQ: issB, ACK: issA + 1, Flags: FINACK, WND: windowB}
|
|
var tcbB tcp.ControlBlock
|
|
tcbB.HelperInitState(tcp.StateEstablished, issB, issB, windowB)
|
|
tcbB.HelperInitRcv(issA, issA, windowA)
|
|
tcbB.HelperExchange(t, exchangeB)
|
|
}
|
|
|
|
/*
|
|
Figure 12: Simultaneous Close Sequence
|
|
TCP Peer A TCP Peer B
|
|
|
|
1. ESTABLISHED ESTABLISHED
|
|
|
|
2. (Close) (Close)
|
|
FIN-WAIT-1 --> <SEQ=100><ACK=300><CTL=FIN,ACK> ... FIN-WAIT-1
|
|
<-- <SEQ=300><ACK=100><CTL=FIN,ACK> <--
|
|
... <SEQ=100><ACK=300><CTL=FIN,ACK> -->
|
|
|
|
3. CLOSING --> <SEQ=101><ACK=301><CTL=ACK> ... CLOSING
|
|
<-- <SEQ=301><ACK=101><CTL=ACK> <--
|
|
... <SEQ=101><ACK=301><CTL=ACK> -->
|
|
|
|
4. TIME-WAIT TIME-WAIT
|
|
(2 MSL) (2 MSL)
|
|
CLOSED CLOSED
|
|
*/
|
|
func TestExchange_rfc9293_figure13(t *testing.T) {
|
|
const issA, issB, windowA, windowB = 100, 300, 1000, 1000
|
|
exchangeA := []tcp.Exchange{
|
|
0: { // A sends FIN|ACK to B to begin closing connection.
|
|
Outgoing: &tcp.Segment{SEQ: issA, ACK: issB, Flags: FINACK, WND: windowA},
|
|
WantState: tcp.StateFinWait1,
|
|
},
|
|
1: { // A receives FIN|ACK from B, who sent packet before receiving A's FINACK.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: issA, Flags: FINACK, WND: windowB},
|
|
WantState: tcp.StateClosing,
|
|
WantPending: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
},
|
|
2: { // A sends ACK to B.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantState: tcp.StateTimeWait,
|
|
},
|
|
}
|
|
var tcbA tcp.ControlBlock
|
|
tcbA.HelperInitState(tcp.StateEstablished, issA, issA, windowA)
|
|
tcbA.HelperInitRcv(issB, issB, windowB)
|
|
tcbA.HelperExchange(t, exchangeA)
|
|
|
|
// No need to test B since exchange is completely symmetric.
|
|
}
|
|
|
|
// Check no duplicate ack is sent during establishment.
|
|
func TestExchange_noDupAckDuringEstablished(t *testing.T) {
|
|
var tcbA tcp.ControlBlock
|
|
const issA, issB, windowA, windowB = 300, 334222749, 256, 64240
|
|
synseg := tcp.ClientSynSegment(issA, windowA)
|
|
|
|
// err := tcbA.Open(issA, issA, tcp.StateSynSent)
|
|
tcbA.SetRecvWindow(windowA)
|
|
// if err != nil {
|
|
// t.Fatal(err)
|
|
// }
|
|
establishA := []tcp.Exchange{
|
|
0: { // A sends SYN to B.
|
|
Outgoing: &synseg,
|
|
WantState: tcp.StateSynSent,
|
|
},
|
|
1: { // B sends SYN to A.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: 0, WND: windowB, Flags: tcp.FlagSYN},
|
|
WantPending: &tcp.Segment{SEQ: issA, ACK: issB + 1, WND: windowA, Flags: SYNACK},
|
|
WantState: tcp.StateSynRcvd,
|
|
},
|
|
2: { // Send SYNACK to B.
|
|
Outgoing: &tcp.Segment{SEQ: issA, ACK: issB + 1, WND: windowA, Flags: SYNACK},
|
|
WantState: tcp.StateSynRcvd,
|
|
},
|
|
3: { // B ACKs SYNACK, thus establishing the connection on both sides.
|
|
Incoming: &tcp.Segment{SEQ: issB + 1, ACK: issA + 1, WND: windowB, Flags: tcp.FlagACK},
|
|
WantState: tcp.StateEstablished,
|
|
},
|
|
}
|
|
tcbA.HelperExchange(t, establishA)
|
|
if tcbA.State() != tcp.StateEstablished {
|
|
t.Fatal("expected established state")
|
|
}
|
|
checkNoPending(t, &tcbA)
|
|
const datasize = 5
|
|
dataExA := []tcp.Exchange{
|
|
0: { // B sends PSH|ACK to A with data.
|
|
Incoming: &tcp.Segment{SEQ: issB + 1, ACK: issA + 1, WND: windowB, Flags: PSHACK, DATALEN: datasize},
|
|
WantPending: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1 + datasize, WND: windowA, Flags: tcp.FlagACK},
|
|
WantState: tcp.StateEstablished,
|
|
},
|
|
1: { // A ACKs B's data.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1 + datasize, WND: windowA, Flags: tcp.FlagACK},
|
|
WantState: tcp.StateEstablished,
|
|
},
|
|
2: { // A sends PSH|ACK to B with data, same amount, as if echoing.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1 + datasize, WND: windowA, Flags: PSHACK, DATALEN: datasize},
|
|
WantState: tcp.StateEstablished,
|
|
},
|
|
// 3: { // B ACKs A's data.
|
|
// Incoming: &tcp.Segment{SEQ: issB + 1 + datasize, ACK: issA + 1 + datasize, WND: windowB, Flags: tcp.FlagACK},
|
|
// WantPending: nil,
|
|
// WantState: tcp.StateEstablished,
|
|
// },
|
|
}
|
|
tcbA.HelperExchange(t, dataExA)
|
|
checkNoPending(t, &tcbA)
|
|
tcbA.Recv(tcp.Segment{SEQ: issB + 1 + datasize, ACK: issA + 1 + datasize, WND: windowB, Flags: tcp.FlagACK})
|
|
checkNoPending(t, &tcbA)
|
|
}
|
|
|
|
// This test reenacts a full client-server interaction in the sending and receiving
|
|
// of the 12 byte message "hello world\n" over TCP.
|
|
func TestExchange_helloworld(t *testing.T) {
|
|
// Client Transmission Control Block.
|
|
var tcbA tcp.ControlBlock
|
|
const windowA, windowB = 502, 4096
|
|
const issA, issB = 0x5e722b7d, 0xbe6e4c0f
|
|
const datalen = 12
|
|
|
|
exchangeA := []tcp.Exchange{
|
|
0: { // A sends SYN to B.
|
|
Outgoing: &tcp.Segment{SEQ: issA, Flags: tcp.FlagSYN, WND: windowA},
|
|
WantState: tcp.StateSynSent,
|
|
WantPeerState: tcp.StateSynRcvd,
|
|
},
|
|
1: { // A receives SYNACK from B.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: issA + 1, Flags: SYNACK, WND: windowB},
|
|
WantState: tcp.StateEstablished,
|
|
WantPending: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantPeerState: tcp.StateSynRcvd,
|
|
},
|
|
2: { // A sends ACK to B thus establishing connection.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantState: tcp.StateEstablished,
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
3: { // A sends PSH|ACK to B with 12 byte message: "hello world\n"
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1, ACK: issB + 1, Flags: PSHACK, WND: windowA, DATALEN: datalen},
|
|
WantState: tcp.StateEstablished,
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
4: { // A receives ACK from B of last message.
|
|
Incoming: &tcp.Segment{SEQ: issB + 1, ACK: issA + 1 + datalen, Flags: tcp.FlagACK, WND: windowB},
|
|
WantState: tcp.StateEstablished,
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
5: { // A receives PSH|ACK from B with echoed 12 byte message: "hello world\n"
|
|
Incoming: &tcp.Segment{SEQ: issB + 1, ACK: issA + 1 + datalen, Flags: PSHACK, WND: windowB, DATALEN: datalen},
|
|
WantState: tcp.StateEstablished,
|
|
WantPending: &tcp.Segment{SEQ: issA + 1 + datalen, ACK: issB + 1 + datalen, Flags: tcp.FlagACK, WND: windowA},
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
6: { // A ACKs B's message.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1 + datalen, ACK: issB + 1 + datalen, Flags: tcp.FlagACK, WND: windowA},
|
|
WantState: tcp.StateEstablished,
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
7: { // A sends PSH|ACK to B with SECOND 12 byte message.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1 + datalen, ACK: issB + 1 + datalen, Flags: PSHACK, WND: windowA, DATALEN: datalen},
|
|
WantState: tcp.StateEstablished,
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
8: { // A receives PSH|ACK that acks last message and contains echoed of SECOND 12 byte message.
|
|
Incoming: &tcp.Segment{SEQ: issB + 1 + datalen, ACK: issA + 1 + 2*datalen, Flags: PSHACK, WND: windowB, DATALEN: datalen},
|
|
WantState: tcp.StateEstablished,
|
|
WantPending: &tcp.Segment{SEQ: issA + 1 + 2*datalen, ACK: issB + 1 + 2*datalen, Flags: tcp.FlagACK, WND: windowA},
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
9: { // A ACKs B's SECOND message.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1 + 2*datalen, ACK: issB + 1 + 2*datalen, Flags: tcp.FlagACK, WND: windowA},
|
|
WantState: tcp.StateEstablished,
|
|
WantPeerState: tcp.StateEstablished,
|
|
},
|
|
10: { // A sends FIN|ACK to B to close connection.
|
|
Outgoing: &tcp.Segment{SEQ: issA + 1 + 2*datalen, ACK: issB + 1 + 2*datalen, Flags: FINACK, WND: windowA},
|
|
WantState: tcp.StateFinWait1,
|
|
WantPeerState: tcp.StateCloseWait,
|
|
},
|
|
11: { // A receives B's ACK of FIN.
|
|
Incoming: &tcp.Segment{SEQ: issB + 1 + 2*datalen, ACK: issA + 2 + 2*datalen, Flags: tcp.FlagACK, WND: windowB},
|
|
WantState: tcp.StateFinWait2,
|
|
WantPending: &tcp.Segment{SEQ: issA + 2 + 2*datalen, ACK: issB + 1 + 2*datalen, Flags: tcp.FlagACK, WND: windowA},
|
|
WantPeerState: tcp.StateCloseWait,
|
|
},
|
|
}
|
|
// The client starts in the SYN_SENT state with a random sequence number.
|
|
gotServerSeg, _ := parseSegment(t, exchangeHelloWorld[0])
|
|
tcbA.HelperInitState(tcp.StateSynSent, gotServerSeg.SEQ, gotServerSeg.SEQ, windowB)
|
|
tcbA.HelperExchange(t, exchangeA)
|
|
|
|
// TODO(soypat): fix exchange reversal.
|
|
return
|
|
exchangeB := reverseExchange(exchangeA)
|
|
|
|
exchangeB[7].WantPending = nil // Is an unpredicable action.
|
|
var tcbB tcp.ControlBlock
|
|
tcbB.HelperInitState(tcp.StateListen, issB, issB, windowB)
|
|
tcbB.HelperInitRcv(issA, issA, windowA)
|
|
tcbB.HelperExchange(t, exchangeB)
|
|
}
|
|
|
|
func TestResetEstablished(t *testing.T) {
|
|
var tcb tcp.ControlBlock
|
|
const windowA, windowB = 502, 4096
|
|
const issA, issB = 0x5e722b7d, 0xbe6e4c0f
|
|
tcb.HelperInitState(tcp.StateEstablished, issA, issA, windowA)
|
|
tcb.HelperInitRcv(issB, issB, windowB)
|
|
|
|
err := tcb.Recv(tcp.Segment{SEQ: issB, ACK: issA, Flags: tcp.FlagRST, WND: windowB})
|
|
if err == nil {
|
|
t.Fatal("expected error")
|
|
}
|
|
if tcb.State() != tcp.StateClosed {
|
|
t.Error("expected closed state; got ", tcb.State().String())
|
|
}
|
|
checkNoPending(t, &tcb)
|
|
}
|
|
|
|
func TestFinackClose(t *testing.T) {
|
|
var tcb tcp.ControlBlock
|
|
const windowA, windowB = 502, 4096
|
|
const issA, issB = 100, 200
|
|
tcb.HelperInitState(tcp.StateEstablished, issA, issA, windowA)
|
|
tcb.HelperInitRcv(issB, issB, windowB)
|
|
// Start closing process.
|
|
err := tcb.Close()
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
seg, ok := tcb.PendingSegment(0)
|
|
if !ok {
|
|
t.Fatal("expected pending segment")
|
|
}
|
|
if !seg.Flags.HasAll(tcp.FlagFIN | tcp.FlagACK) {
|
|
t.Fatalf("expected FIN|ACK; got %s", seg.Flags.String())
|
|
}
|
|
err = tcb.Send(seg)
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
if tcb.State() != tcp.StateFinWait1 {
|
|
t.Fatalf("expected FinWait1; got %s", tcb.State().String())
|
|
}
|
|
// Special case where we receive FINACK all together, we can streamline and go into TimeWait.
|
|
err = tcb.Recv(tcp.Segment{
|
|
SEQ: issB,
|
|
ACK: issA + 1,
|
|
WND: windowB,
|
|
Flags: FINACK,
|
|
})
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
if tcb.State() != tcp.StateTimeWait {
|
|
t.Fatalf("expected TimeWait after FINACK; got %s", tcb.State().String())
|
|
}
|
|
}
|
|
|
|
func TestExchange_helloworld_client(t *testing.T) {
|
|
return
|
|
// Client Transmission Control Block.
|
|
var tcb tcp.ControlBlock
|
|
// The client starts in the SYN_SENT state with a random sequence number.
|
|
gotClientSeg, _ := parseSegment(t, exchangeHelloWorld[0])
|
|
|
|
// We add the SYN state to the client.
|
|
tcb.HelperInitState(tcp.StateSynSent, gotClientSeg.SEQ, gotClientSeg.SEQ, gotClientSeg.WND)
|
|
err := tcb.Send(gotClientSeg)
|
|
if err != nil {
|
|
|
|
t.Fatal(err)
|
|
}
|
|
tcb.HelperPrintSegment(t, false, gotClientSeg)
|
|
|
|
segString := func(seg tcp.Segment) string {
|
|
return tcb.RelativeAutoSegment(seg).RelativeGoString(0, 0)
|
|
}
|
|
for i, packet := range exchangeHelloWorld {
|
|
if i == 0 {
|
|
continue // we already processed first packet.
|
|
}
|
|
seg, payload := parseSegment(t, packet)
|
|
if seg.DATALEN > 0 {
|
|
t.Logf("seg[%d] <%s> payload: %q", i, tcb.State(), string(payload))
|
|
} else {
|
|
t.Logf("seg[%d] <%s>", i, tcb.State())
|
|
}
|
|
isClient := packet[0] == 0x28
|
|
if isClient {
|
|
isPSH := seg.Flags&tcp.FlagPSH != 0
|
|
gotClientSeg.Flags |= seg.Flags & (tcp.FlagPSH | tcp.FlagFIN) // Can't predict when client will send FIN.
|
|
if isPSH {
|
|
gotClientSeg.DATALEN = seg.DATALEN
|
|
}
|
|
|
|
gotClientSeg.WND = seg.WND // Ignore window field, not a core part of control flow.
|
|
if gotClientSeg != seg {
|
|
t.Fatalf("client:\n got=%+v\nwant=%+v", segString(gotClientSeg), segString(seg))
|
|
}
|
|
err := tcb.Send(gotClientSeg)
|
|
if err != nil {
|
|
t.Fatalf("incoming %s:\nseg[%d]=%s\nrcv=%+v\nsnd=%+v", err, i, segString(gotClientSeg), tcb.RelativeRecvSpace(), tcb.RelativeSendSpace())
|
|
}
|
|
tcb.HelperPrintSegment(t, false, gotClientSeg)
|
|
continue // we only pass server packets to the client.
|
|
}
|
|
err = tcb.Recv(seg)
|
|
if err != nil {
|
|
t.Fatalf("%s:\nseg[%d]=%s\nrcv=%+v\nsnd=%+v", err, i, segString(seg), tcb.RelativeRecvSpace(), tcb.RelativeSendSpace())
|
|
}
|
|
tcb.HelperPrintSegment(t, true, seg)
|
|
var ok bool
|
|
gotClientSeg, ok = tcb.PendingSegment(0)
|
|
if !ok {
|
|
t.Fatalf("[%d]: got no segment state=%s", i, tcb.State())
|
|
}
|
|
}
|
|
}
|
|
|
|
func parseSegment(t *testing.T, b []byte) (tcp.Segment, []byte) {
|
|
var vld lneto.Validator
|
|
t.Helper()
|
|
efrm, err := ethernet.NewFrame(b)
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
if efrm.EtherTypeOrSize() != ethernet.TypeIPv4 {
|
|
t.Fatalf("not IPv4")
|
|
}
|
|
efrm.ValidateSize(&vld)
|
|
if err := vld.ErrPop(); err != nil {
|
|
t.Fatal(vld.ErrPop())
|
|
}
|
|
ifrm, err := ipv4.NewFrame(efrm.Payload())
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
if ifrm.Protocol() != 6 {
|
|
t.Fatalf("not TCP")
|
|
}
|
|
v, _ := ifrm.VersionAndIHL()
|
|
if v != 4 {
|
|
t.Fatal("invalid IP version", v)
|
|
}
|
|
ifrm.ValidateSize(&vld)
|
|
if err := vld.ErrPop(); err != nil {
|
|
t.Fatal(vld.ErrPop())
|
|
}
|
|
|
|
ipl := ifrm.Payload()
|
|
tfrm, err := tcp.NewFrame(ipl)
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
tfrm.ValidateSize(&vld)
|
|
if err := vld.ErrPop(); err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
_ = tfrm.String()
|
|
payload := tfrm.Payload()
|
|
return tfrm.Segment(len(payload)), payload
|
|
}
|
|
|
|
func reverseExchange(exchange []tcp.Exchange) []tcp.Exchange {
|
|
if len(exchange) == 0 {
|
|
panic("len(exchange) != len(states) or empty exchange: " + strconv.Itoa(len(exchange)))
|
|
}
|
|
firstIsIn := exchange[0].Incoming != nil
|
|
if firstIsIn {
|
|
panic("please start with an outgoing segment to reverse exchange for best test results")
|
|
}
|
|
out := make([]tcp.Exchange, len(exchange))
|
|
for i := range exchange {
|
|
isLast := i == len(exchange)-1
|
|
isOut := exchange[i].Outgoing != nil
|
|
out[i].WantState, out[i].WantPeerState = exchange[i].WantPeerState, exchange[i].WantState
|
|
if isOut {
|
|
out[i].Incoming = exchange[i].Outgoing
|
|
if !isLast {
|
|
out[i].WantPending = exchange[i+1].Incoming
|
|
}
|
|
} else {
|
|
out[i].Outgoing = exchange[i].Incoming
|
|
}
|
|
}
|
|
return out
|
|
}
|
|
|
|
func checkNoPending(t *testing.T, tcb *tcp.ControlBlock) bool {
|
|
t.Helper()
|
|
// We extensively test the API for inadvertent state modification in a HasPending or PendingSegment call.
|
|
hasPD := tcb.HasPending()
|
|
pd, ok := tcb.PendingSegment(0)
|
|
hasPD2 := tcb.HasPending()
|
|
if hasPD || ok || hasPD2 {
|
|
t.Errorf("unexpected pending segment: %+v (%v,%v,%v)", pd, hasPD, ok, hasPD2)
|
|
return false
|
|
}
|
|
if hasPD != ok || hasPD != hasPD2 {
|
|
t.Fatalf("inconsistent pending segment: (%v,%v,%v)", hasPD, ok, hasPD2)
|
|
}
|
|
if !ok && pd != (tcp.Segment{}) {
|
|
t.Fatalf("inconsistent pending segment: %+v (%v,%v,%v)", pd, hasPD, ok, hasPD2)
|
|
}
|
|
return true
|
|
}
|
|
|
|
// Full client-server interaction in the sending of "hello world" over TCP in order.
|
|
var exchangeHelloWorld = [][]byte{
|
|
// client SYN1
|
|
0: []byte("\x28\xcd\xc1\x05\x4d\xbb\xd8\x5e\xd3\x43\x03\xeb\x08\x00\x45\x00\x00\x3c\x71\xac\x40\x00\x40\x06\x44\x9b\xc0\xa8\x01\x93\xc0\xa8\x01\x91\x84\x96\x04\xd2\x5e\x72\x2b\x7d\x00\x00\x00\x00\xa0\x02\xfa\xf0\x27\x6d\x00\x00\x02\x04\x05\xb4\x04\x02\x08\x0a\x07\x8b\x86\x4a\x00\x00\x00\x00\x01\x03\x03\x07"),
|
|
// server SYNACK
|
|
1: []byte("\xd8\x5e\xd3\x43\x03\xeb\x28\xcd\xc1\x05\x4d\xbb\x08\x00\x45\x00\x00\x34\x00\x00\x40\x00\x40\x06\xb6\x4f\xc0\xa8\x01\x91\xc0\xa8\x01\x93\x04\xd2\x84\x96\xbe\x6e\x4c\x0f\x5e\x72\x2b\x7e\x80\x12\x10\x00\xc0\xbb\x00\x00\x02\x04\x05\xb4\x03\x03\x00\x04\x02\x00\x00\x00"),
|
|
// client ACK1
|
|
2: []byte("\x28\xcd\xc1\x05\x4d\xbb\xd8\x5e\xd3\x43\x03\xeb\x08\x00\x45\x00\x00\x28\x71\xad\x40\x00\x40\x06\x44\xae\xc0\xa8\x01\x93\xc0\xa8\x01\x91\x84\x96\x04\xd2\x5e\x72\x2b\x7e\xbe\x6e\x4c\x10\x50\x10\x01\xf6\x0b\x92\x00\x00"),
|
|
// client PSHACK0
|
|
3: []byte("\x28\xcd\xc1\x05\x4d\xbb\xd8\x5e\xd3\x43\x03\xeb\x08\x00\x45\x00\x00\x34\x71\xae\x40\x00\x40\x06\x44\xa1\xc0\xa8\x01\x93\xc0\xa8\x01\x91\x84\x96\x04\xd2\x5e\x72\x2b\x7e\xbe\x6e\x4c\x10\x50\x18\x01\xf6\x79\xa5\x00\x00\x68\x65\x6c\x6c\x6f\x20\x77\x6f\x72\x6c\x64\x0a"),
|
|
// server ACK1
|
|
4: []byte("\xd8\x5e\xd3\x43\x03\xeb\x28\xcd\xc1\x05\x4d\xbb\x08\x00\x45\x00\x00\x28\x00\x00\x40\x00\x40\x06\xb6\x5b\xc0\xa8\x01\x91\xc0\xa8\x01\x93\x04\xd2\x84\x96\xbe\x6e\x4c\x10\x5e\x72\x2b\x8a\x50\x10\x0f\xf4\xfd\x87\x00\x00\x00\x00\x00\x00\x00\x00"),
|
|
// server PSHACK1
|
|
5: []byte("\xd8\x5e\xd3\x43\x03\xeb\x28\xcd\xc1\x05\x4d\xbb\x08\x00\x45\x00\x00\x34\x00\x00\x40\x00\x40\x06\xb6\x4f\xc0\xa8\x01\x91\xc0\xa8\x01\x93\x04\xd2\x84\x96\xbe\x6e\x4c\x10\x5e\x72\x2b\x8a\x50\x18\x10\x00\x6b\x8f\x00\x00\x68\x65\x6c\x6c\x6f\x20\x77\x6f\x72\x6c\x64\x0a"),
|
|
// client ACK2
|
|
6: []byte("\x28\xcd\xc1\x05\x4d\xbb\xd8\x5e\xd3\x43\x03\xeb\x08\x00\x45\x00\x00\x28\x71\xaf\x40\x00\x40\x06\x44\xac\xc0\xa8\x01\x93\xc0\xa8\x01\x91\x84\x96\x04\xd2\x5e\x72\x2b\x8a\xbe\x6e\x4c\x1c\x50\x10\x01\xf6\x0b\x7a\x00\x00"),
|
|
// client PSHACK1
|
|
7: []byte("\x28\xcd\xc1\x05\x4d\xbb\xd8\x5e\xd3\x43\x03\xeb\x08\x00\x45\x00\x00\x34\x71\xb0\x40\x00\x40\x06\x44\x9f\xc0\xa8\x01\x93\xc0\xa8\x01\x91\x84\x96\x04\xd2\x5e\x72\x2b\x8a\xbe\x6e\x4c\x1c\x50\x18\x01\xf6\x79\x8d\x00\x00\x68\x65\x6c\x6c\x6f\x20\x77\x6f\x72\x6c\x64\x0a"),
|
|
// server PSHACK2
|
|
8: []byte("\xd8\x5e\xd3\x43\x03\xeb\x28\xcd\xc1\x05\x4d\xbb\x08\x00\x45\x00\x00\x34\x00\x00\x40\x00\x40\x06\xb6\x4f\xc0\xa8\x01\x91\xc0\xa8\x01\x93\x04\xd2\x84\x96\xbe\x6e\x4c\x1c\x5e\x72\x2b\x96\x50\x18\x10\x00\x6b\x77\x00\x00\x68\x65\x6c\x6c\x6f\x20\x77\x6f\x72\x6c\x64\x0a"),
|
|
// client ACK3
|
|
9: []byte("\x28\xcd\xc1\x05\x4d\xbb\xd8\x5e\xd3\x43\x03\xeb\x08\x00\x45\x00\x00\x28\x71\xb1\x40\x00\x40\x06\x44\xaa\xc0\xa8\x01\x93\xc0\xa8\x01\x91\x84\x96\x04\xd2\x5e\x72\x2b\x96\xbe\x6e\x4c\x28\x50\x10\x01\xf6\x0b\x62\x00\x00"),
|
|
// client FINACK
|
|
10: []byte("\x28\xcd\xc1\x05\x4d\xbb\xd8\x5e\xd3\x43\x03\xeb\x08\x00\x45\x00\x00\x28\x71\xb2\x40\x00\x40\x06\x44\xa9\xc0\xa8\x01\x93\xc0\xa8\x01\x91\x84\x96\x04\xd2\x5e\x72\x2b\x96\xbe\x6e\x4c\x28\x50\x11\x01\xf6\x0b\x61\x00\x00"),
|
|
// server ACK
|
|
11: []byte("\xd8\x5e\xd3\x43\x03\xeb\x28\xcd\xc1\x05\x4d\xbb\x08\x00\x45\x00\x00\x28\x00\x00\x40\x00\x40\x06\xb6\x5b\xc0\xa8\x01\x91\xc0\xa8\x01\x93\x04\xd2\x84\x96\xbe\x6e\x4c\x28\x5e\x72\x2b\x97\x50\x10\x10\x00\xfd\x56\x00\x00\x00\x00\x00\x00\x00\x00"),
|
|
}
|
|
|
|
func TestUnexpectedStateClosing(t *testing.T) {
|
|
// TCB is a server which returns an HTTP response and receives a FINACK.
|
|
var tcb tcp.ControlBlock
|
|
const httpLen = 1192
|
|
const issA, issB, windowA, windowB = 1, 127, 2000, 2000
|
|
tcb.HelperInitState(tcp.StateEstablished, issA, issA, windowA)
|
|
tcb.HelperInitRcv(issB, issB, windowB)
|
|
|
|
ex := []tcp.Exchange{
|
|
0: { // Server sends HTTP response.
|
|
Outgoing: &tcp.Segment{SEQ: issA, ACK: issB, Flags: PSHACK, WND: windowA, DATALEN: httpLen},
|
|
WantState: tcp.StateEstablished,
|
|
},
|
|
1: { // Client sends an ACK to server.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: issA + httpLen, Flags: tcp.FlagACK, WND: windowB},
|
|
WantState: tcp.StateEstablished,
|
|
},
|
|
2: { // Client sends FIN|ACK to server.
|
|
Incoming: &tcp.Segment{SEQ: issB, ACK: issA + httpLen, Flags: FINACK, WND: windowB},
|
|
WantPending: &tcp.Segment{SEQ: issA + httpLen, ACK: issB + 1, Flags: tcp.FlagACK, WND: windowA},
|
|
WantState: tcp.StateCloseWait,
|
|
},
|
|
3: { // Server sends out FINACK.
|
|
Outgoing: &tcp.Segment{SEQ: issA + httpLen, ACK: issB + 1, Flags: FINACK, WND: windowA},
|
|
WantState: tcp.StateLastAck,
|
|
},
|
|
4: { // Client sends back ACK.
|
|
Incoming: &tcp.Segment{SEQ: issB + 1, ACK: issA + httpLen + 1, Flags: tcp.FlagACK, WND: windowB},
|
|
WantState: tcp.StateClosed,
|
|
},
|
|
}
|
|
tcb.HelperExchange(t, ex[:])
|
|
}
|
|
|
|
// This corresponds to https://github.com/soypat/seqs/issues/19
|
|
// The bug consisted of a panic condition encountered when using wget client with a seqs based server.
|
|
// Thanks to @knieriem for finding this and the detailed report they submitted.
|
|
func TestIssue19(t *testing.T) {
|
|
var tcb tcp.ControlBlock
|
|
assertState := func(state tcp.State) {
|
|
t.Helper()
|
|
if tcb.State() != state {
|
|
t.Fatalf("want state %s; got %s", state.String(), tcb.State().String())
|
|
}
|
|
}
|
|
const httpLen = 1192
|
|
const issA, issB, windowA, windowB = 1, 0, 2000, 2000
|
|
tcb.HelperInitState(tcp.StateEstablished, issA, issA, windowA)
|
|
tcb.HelperInitRcv(issB, issB, windowB)
|
|
|
|
// Send out HTTP request and close connection.
|
|
err := tcb.Send(tcp.Segment{SEQ: issA, ACK: issB, Flags: PSHACK, WND: windowA, DATALEN: httpLen})
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
err = tcb.Close()
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
assertState(tcp.StateEstablished)
|
|
|
|
pending, ok := tcb.PendingSegment(0)
|
|
if !ok {
|
|
t.Fatal("expected pending segment")
|
|
} else if pending.Flags != FINACK {
|
|
t.Fatalf("expected FINACK; got %s", pending.Flags.String())
|
|
}
|
|
|
|
// Receive ACK of HTTP segment.
|
|
err = tcb.Recv(tcp.Segment{SEQ: issB, ACK: issA + httpLen, Flags: tcp.FlagACK, WND: windowB})
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
assertState(tcp.StateEstablished)
|
|
err = tcb.Close()
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
pending, ok = tcb.PendingSegment(0)
|
|
if !ok {
|
|
t.Fatal("expected pending segment")
|
|
} else if pending.Flags != FINACK {
|
|
t.Fatalf("expected FINACK; got %s", pending.Flags.String())
|
|
}
|
|
|
|
// Send out FINACK.
|
|
err = tcb.Send(pending)
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
assertState(tcp.StateFinWait1)
|
|
|
|
// Receive FINACK response from client.
|
|
err = tcb.Recv(tcp.Segment{SEQ: issB, ACK: issA + httpLen, Flags: FINACK, WND: windowB})
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
assertState(tcp.StateClosing)
|
|
pending, ok = tcb.PendingSegment(0)
|
|
if !ok {
|
|
t.Fatal("expected pending segment")
|
|
} else if pending.Flags != tcp.FlagACK {
|
|
t.Fatalf("expected ACK; got %s", pending.Flags.String())
|
|
}
|
|
|
|
// Before responding we receive an ACK from client. This is where panic is triggered.
|
|
err = tcb.Recv(tcp.Segment{SEQ: issB + 1, ACK: issA + httpLen + 1, Flags: tcp.FlagACK, WND: windowB})
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
assertState(tcp.StateTimeWait)
|
|
|
|
// Check we still need to send an ACK.
|
|
pending, ok = tcb.PendingSegment(0)
|
|
if !ok {
|
|
t.Fatal("expected pending segment")
|
|
} else if pending.Flags != tcp.FlagACK {
|
|
t.Fatalf("expected ACK; got %s", pending.Flags.String())
|
|
}
|
|
// Prepare response to client.
|
|
err = tcb.Send(pending)
|
|
if err != nil {
|
|
t.Fatal(err)
|
|
}
|
|
}
|
|
|
|
func FuzzTCBActions(f *testing.F) {
|
|
const mtu = 2048
|
|
const (
|
|
actionRecv = iota
|
|
actionSend
|
|
actionClose
|
|
actionMax
|
|
)
|
|
f.Add(
|
|
0x2313_2313,
|
|
[]byte{actionSend, actionRecv, actionSend, actionRecv, actionSend, actionRecv},
|
|
)
|
|
f.Add(
|
|
0x2fefe_feefe,
|
|
[]byte{actionSend, actionRecv, actionSend, actionClose, actionSend, actionRecv},
|
|
)
|
|
f.Add(
|
|
0x2fefe_feefe,
|
|
[]byte{actionClose, actionRecv, actionSend, actionClose, actionSend, actionRecv},
|
|
)
|
|
recvsendSize := func(rng *rand.Rand) int {
|
|
return rng.Int() % mtu
|
|
}
|
|
f.Fuzz(func(t *testing.T, seed int, actions []byte) {
|
|
if len(actions) == 0 || len(actions) > 100 {
|
|
t.SkipNow()
|
|
}
|
|
rng := rand.New(rand.NewSource(int64(seed)))
|
|
var clientISS tcp.Value = tcp.Value(rng.Int31())
|
|
var serverISS tcp.Value = tcp.Value(rng.Int31())
|
|
|
|
var client tcp.ControlBlock
|
|
client.HelperInitState(tcp.StateEstablished, clientISS, clientISS, mtu)
|
|
client.HelperInitRcv(serverISS, serverISS, mtu)
|
|
|
|
var server tcp.ControlBlock
|
|
server.HelperInitState(tcp.StateEstablished, serverISS, serverISS, mtu)
|
|
server.HelperInitRcv(clientISS, clientISS, mtu)
|
|
var closeCalled bool
|
|
// logger := slog.New(slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
|
|
// Level: slog.LevelDebug - 2,
|
|
// }))
|
|
// client.SetLogger(logger.WithGroup("client"))
|
|
// server.SetLogger(logger.WithGroup("server"))
|
|
// var exchanges []tcp.Exchange
|
|
// hasPanicked := true
|
|
// defer func() {
|
|
// if hasPanicked {
|
|
// for _, ex := range exchanges {
|
|
// t.Log(ex.RFC9293String(tcp.StateEstablished, tcp.StateEstablished))
|
|
// }
|
|
// }
|
|
// }()
|
|
for _, action := range actions {
|
|
v := recvsendSize(rng)
|
|
switch action % actionMax {
|
|
case actionSend:
|
|
seg, ok := client.PendingSegment(v % mtu)
|
|
if ok {
|
|
// exchanges = append(exchanges, tcp.Exchange{Outgoing: &seg})
|
|
err := client.Send(seg)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
err = server.Recv(seg)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
}
|
|
case actionRecv:
|
|
seg, ok := server.PendingSegment(v % mtu)
|
|
if ok {
|
|
// exchanges = append(exchanges, tcp.Exchange{Incoming: &seg})
|
|
err := server.Send(seg)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
err = client.Recv(seg)
|
|
if err != nil && !closeCalled {
|
|
panic(err)
|
|
}
|
|
}
|
|
case actionClose:
|
|
err := client.Close()
|
|
if err != nil && !closeCalled {
|
|
panic(err)
|
|
}
|
|
closeCalled = true
|
|
return
|
|
}
|
|
}
|
|
// hasPanicked = false
|
|
})
|
|
}
|