forked from weaveworks/weave
/
pcap.go
59 lines (52 loc) · 1.24 KB
/
pcap.go
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package weave
import (
"code.google.com/p/gopacket/pcap"
)
type PcapIO struct {
handle *pcap.Handle
}
func NewPcapIO(ifName string, bufSz int) (pio PacketSourceSink, err error) {
pio, err = newPcapIO(ifName, true, 65535, bufSz)
return
}
func NewPcapO(ifName string) (po PacketSink, err error) {
po, err = newPcapIO(ifName, false, 0, 0)
return
}
func newPcapIO(ifName string, promisc bool, snaplen int, bufSz int) (handle *PcapIO, err error) {
inactive, err := pcap.NewInactiveHandle(ifName)
if err != nil {
return
}
defer inactive.CleanUp()
if err = inactive.SetPromisc(promisc); err != nil {
return
}
if err = inactive.SetSnapLen(snaplen); err != nil {
return
}
if err = inactive.SetTimeout(-1); err != nil {
return
}
if err = inactive.SetImmediateMode(true); err != nil {
return
}
if err = inactive.SetBufferSize(bufSz); err != nil {
return
}
active, err := inactive.Activate()
if err != nil {
return
}
if err = active.SetDirection(pcap.DirectionIn); err != nil {
return
}
return &PcapIO{handle: active}, nil
}
func (pi *PcapIO) ReadPacket() (data []byte, err error) {
data, _, err = pi.handle.ZeroCopyReadPacketData()
return
}
func (po *PcapIO) WritePacket(data []byte) error {
return po.handle.WritePacketData(data)
}