huge improvements to stack example

This commit is contained in:
soypat
2025-01-24 17:30:23 -03:00
parent f2ce6312d3
commit b40927ebcd
3 changed files with 37 additions and 22 deletions
+19 -14
View File
@@ -2,6 +2,7 @@ package ltesto
import (
"bytes"
"math"
"math/rand"
"github.com/soypat/lneto"
@@ -34,13 +35,17 @@ func (gen *PacketGen) RandomizeAddrs(rng *rand.Rand) {
gen.DstTCP = uint16(ports >> 16)
}
func (gen *PacketGen) AppendRandomIPv4TCPPacket(dst []byte, rng *rand.Rand) []byte {
func (gen *PacketGen) AppendRandomIPv4TCPPacket(dst []byte, rng *rand.Rand, seg tcp.Segment) []byte {
if seg.WND > math.MaxUint16 {
panic("TCP segment window overflow")
} else if seg.DATALEN > 2048 {
panic("too long datalen")
}
ri := rng.Int()
var (
isVLAN = ri&(1<<0) != 0
hasIPOpt = ri&(1<<1) != 0
hasTCPOpt = ri&(1<<2) != 0
hasPayload = ri&(1<<3) != 0
isVLAN = ri&(1<<0) != 0
hasIPOpt = ri&(1<<1) != 0
hasTCPOpt = ri&(1<<2) != 0
)
var etherType lneto.EtherType = lneto.EtherTypeIPv4
var ipOpts []byte
@@ -56,14 +61,11 @@ func (gen *PacketGen) AppendRandomIPv4TCPPacket(dst []byte, rng *rand.Rand) []by
if hasTCPOpt {
tcpOpts = []byte{byte(tcp.OptSACKPermitted), 0, 1, 0}
}
var payloadLen int
if hasPayload {
payloadLen = (ri >> 16) % 1024
}
ipOptWLen := sizeWord(len(ipOpts))
tcpOptWlen := sizeWord(len(tcpOpts))
off := len(dst)
dst = append(dst, make([]byte, ethsize+sizeHeaderIPv4+4*int(ipOptWLen)+sizeHeaderTCP+4*int(tcpOptWlen)+payloadLen)...)
dst = append(dst, make([]byte, ethsize+sizeHeaderIPv4+4*int(ipOptWLen)+sizeHeaderTCP+4*int(tcpOptWlen)+int(seg.DATALEN))...)
efrm, err := lneto.NewEthFrame(dst[off:])
if err != nil {
panic(err)
@@ -99,11 +101,11 @@ func (gen *PacketGen) AppendRandomIPv4TCPPacket(dst []byte, rng *rand.Rand) []by
}
tfrm.SetSourcePort(gen.SrcTCP)
tfrm.SetDestinationPort(gen.DstTCP)
tfrm.SetSeq(tcp.Value(rng.Uint32()))
tfrm.SetAck(tcp.Value(rng.Uint32()))
tfrm.SetSeq(seg.SEQ)
tfrm.SetAck(seg.ACK)
wlen := sizeWord(sizeHeaderTCP + len(tcpOpts))
tfrm.SetOffsetAndFlags(wlen, tcp.Flags(rng.Uint32()))
tfrm.SetWindowSize(uint16(rng.Uint32()))
tfrm.SetOffsetAndFlags(wlen, seg.Flags)
tfrm.SetWindowSize(uint16(seg.WND))
urgPtr := uint16(rng.Uint32())
tfrm.SetUrgentPtr(urgPtr)
tcpPayload := tfrm.Payload()
@@ -111,6 +113,9 @@ func (gen *PacketGen) AppendRandomIPv4TCPPacket(dst []byte, rng *rand.Rand) []by
if len(tcpPayload) > 0 {
rng.Read(tcpPayload)
firstPayloadByte = tcpPayload[0]
if len(tcpPayload) != int(seg.DATALEN) {
panic("incorrect payload length calculation")
}
}
// Set Variable section of data.
copy(ifrm.Options(), ipOpts)