/
packets.go
78 lines (67 loc) · 1.71 KB
/
packets.go
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package packets
import (
"net"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
)
func EthernetHeader(proto layers.EthernetType) []byte {
buf := gopacket.NewSerializeBuffer()
eth := &layers.Ethernet{
SrcMAC: net.HardwareAddr{0, 1, 2, 3, 4, 5},
DstMAC: net.HardwareAddr{5, 4, 3, 2, 1, 0},
EthernetType: proto,
}
if err := eth.SerializeTo(buf, gopacket.SerializeOptions{}); err != nil {
panic(err)
}
return buf.Bytes()[0:14]
}
func IPv4Header(proto layers.IPProtocol) []byte {
buf := gopacket.NewSerializeBuffer()
ip := &layers.IPv4{
SrcIP: net.IP{1, 2, 3, 4},
DstIP: net.IP{5, 6, 7, 8},
Protocol: proto,
}
if err := ip.SerializeTo(buf, gopacket.SerializeOptions{}); err != nil {
panic(err)
}
return buf.Bytes()
}
func TCPPacket(tcp *layers.TCP) []byte {
var packet []byte
packet = append(packet, EthernetHeader(layers.EthernetTypeIPv4)...)
packet = append(packet, IPv4Header(layers.IPProtocolTCP)...)
buf := gopacket.NewSerializeBuffer()
if err := tcp.SerializeTo(buf, gopacket.SerializeOptions{}); err != nil {
panic(err)
}
return append(packet, buf.Bytes()...)
}
// TCPv4ACK constructs an IPv4 TCP ACK packet, and returns the slice
func TCPv4ACK() []byte {
return TCPPacket(&layers.TCP{
SrcPort: 57777,
DstPort: 80,
SYN: false,
ACK: true,
})
}
// TCPv4SYN constructs an IPv4 TCP SYN packet, and returns the slice
func TCPv4SYN() []byte {
return TCPPacket(&layers.TCP{
SrcPort: 57777,
DstPort: 80,
SYN: true,
ACK: false,
})
}
// TCPv4SYNACK constructs an IPv4 TCP SYN/ACK packet, and returns the slice
func TCPv4SYNACK() []byte {
return TCPPacket(&layers.TCP{
SrcPort: 57777,
DstPort: 80,
SYN: true,
ACK: true,
})
}