mirror of
https://github.com/soypat/lneto.git
synced 2026-08-10 18:03:43 +00:00
Pat Whittingslow
64b2647a5e
* tcp: remove retransmit logic entirely; add duplicate ack counting to ControlBlock * retransmit implemented in nice simple straightforward way * narrow down retransmission cases * remove old timing tests * add ControlBlock retransmit test * add failing handler test * reworking payload length semantic meaning in code * fix establish conn logic * clean up tests and add TCB dupack generation and test it * catch pending retransmit satisfy in test * add fuzz test for control block * bugfix: be more strict in what is considered dupack * add IncomingIsDupACK docs * limit queue of retransmits * protect retransmit overflow from incorrectly updating nxt
99 lines
2.1 KiB
Go
99 lines
2.1 KiB
Go
package tcp
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import (
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"testing"
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"github.com/soypat/lneto/internal"
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)
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func FuzzTCPControlBlock(f *testing.F) {
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const (
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mutopFlags = 1 << iota
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mutopSeq
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mutopAck
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mutopMaxBit
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)
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const mutopBits = mutopMaxBit - 1
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const (
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mutPacketBits = 4
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mutFlags = 1 << iota
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)
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const wnd = 1500
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var seed uint64
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editPkt := func(rngSeed, ops uint64, seg *Segment) {
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ops &= mutopBits
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if ops&mutopFlags != 0 {
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seg.Flags ^= Flags(seed & uint64(FlagACK|FlagFIN|FlagRST|FlagSYN))
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}
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if ops&mutopSeq != 0 {
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seg.SEQ = Value(int32(seg.SEQ) + int32(int8(uint8(rngSeed>>32))))
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}
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if ops&mutopAck != 0 {
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seg.ACK = Value(int32(seg.ACK) + int32(int8(uint8(rngSeed>>48))))
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}
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}
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f.Add(seed, uint64(mutopFlags))
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f.Fuzz(func(t *testing.T, seed, op uint64) {
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var tcb0, tcb1 ControlBlock
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iss0 := Value(seed)
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iss1 := Value(seed >> 32)
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err := tcb0.Open(iss0, wnd)
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if err != nil {
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t.Fatal(err)
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}
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synseg := ClientSynSegment(iss1, wnd)
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err = tcb1.Send(synseg)
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if err != nil {
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t.Fatal(err)
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}
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err = tcb0.Recv(synseg)
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if err != nil {
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t.Fatal(err)
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}
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sent := 0
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const maxpkts = 30
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pktEdits := internal.Prand64(seed)
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nextOp := internal.Prand64(op)
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for range maxpkts {
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nextOp = internal.Prand64(nextOp)
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seg0, ok := tcb0.PendingSegment(10)
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if ok {
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edit := pktEdits&1 != 0
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pktEdits >>= 1
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if edit {
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editPkt(seed, nextOp, &seg0)
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}
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err = tcb0.Send(seg0)
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if err == nil {
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sent++
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err = tcb1.Recv(seg0)
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if err != nil {
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t.Fatal("packet sent from TCB0 to TCB1 failed:\n", StringExchange(seg0, tcb0.State(), tcb1.State(), false))
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}
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}
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}
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nextOp = internal.Prand64(nextOp)
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seg1, ok := tcb1.PendingSegment(10)
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if ok {
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edit := pktEdits&1 != 0
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pktEdits >>= 1
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if edit {
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editPkt(seed, nextOp, &seg1)
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}
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err = tcb1.Send(seg1)
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if err == nil {
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sent++
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err = tcb0.Recv(seg1)
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if err != nil {
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t.Fatal("packet sent from TCB1 to TCB0 failed:\n", StringExchange(seg1, tcb0.State(), tcb1.State(), true))
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}
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}
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}
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}
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if sent == 0 {
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t.Fatal("no packets sent")
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}
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})
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}
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