Message too Long

[kkirsche]

To avoid hijacking #150:

I'm getting the following error:

~/g/goddos ❯❯❯ go run testPacket.go
2015/12/02 13:37:04 send: Message too long
exit status 1

from the following code:

package main

import (
    "github.com/google/gopacket"
    "github.com/google/gopacket/layers"
    "github.com/google/gopacket/pcap"
    "log"
    "net"
    "time"
)

var (
    device       string = "en0"
    snapshot_len int32  = 1024
    promiscuous  bool   = false
    err          error
    timeout      time.Duration = 30 * time.Second
    handle       *pcap.Handle
    buffer       gopacket.SerializeBuffer
    options      gopacket.SerializeOptions
)

func main() {
    options.FixLengths = false // This setting as true, false or not here results in the same error

    // Open device
    handle, err = pcap.OpenLive(device, snapshot_len, promiscuous, timeout)
    if err != nil {
        log.Fatal(err)
    }
    defer handle.Close()

    // Send raw bytes over wire
    rawBytes := []byte{10, 20, 30}
    err = handle.WritePacketData(rawBytes)
    if err != nil {
        log.Fatal(err)
    }

    buffer = gopacket.NewSerializeBuffer()

    ipLayer := &layers.IPv4{
        SrcIP: net.IP{127, 0, 0, 1},
        DstIP: net.IP{8, 8, 8, 8},
    }
    ethernetLayer := &layers.Ethernet{
        SrcMAC: net.HardwareAddr{0xFF, 0xAA, 0xFA, 0xAA, 0xFF, 0xAA, 0xFA, 0xAA},
        DstMAC: net.HardwareAddr{0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD},
    }
    tcpLayer := &layers.TCP{
        SrcPort: layers.TCPPort(4321),
        DstPort: layers.TCPPort(80),
    }
    // And create the packet with the layers
    buffer = gopacket.NewSerializeBuffer()
    gopacket.SerializeLayers(buffer, options,
        ethernetLayer,
        ipLayer,
        tcpLayer,
        gopacket.Payload(rawBytes),
    )
    outgoingPacket = buffer.Bytes()

    // Send our packet
    err = handle.WritePacketData(outgoingPacket)
    if err != nil {
        log.Fatal(err)
    }
}

[nhooyr]

// Send raw bytes over wire
rawBytes := []byte{10, 20, 30}
err = handle.WritePacketData(rawBytes)
if err != nil {
    log.Fatal(err)
}

That is whats causing the error on my mac. Otherwise I don't get an error so I don't think its related to #150. That issue only effects raw ip sockets, so this doesn't have anything to do with that.

[kkirsche]

Ah ok. Thanks @nhooyr for looking at that