102 lines
1.9 KiB
Go
102 lines
1.9 KiB
Go
package main
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"net"
|
|
"syscall"
|
|
)
|
|
|
|
var globalFd int
|
|
|
|
func respond(iface string, requests chan *NDRequest, respondType NDPType, filter []*net.IPNet) {
|
|
fd, err := syscall.Socket(syscall.AF_INET6, syscall.SOCK_RAW, syscall.IPPROTO_RAW)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
defer syscall.Close(globalFd)
|
|
globalFd = fd
|
|
err = syscall.BindToDevice(fd, iface)
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
|
|
niface, err := net.InterfaceByName(iface)
|
|
if err != nil {
|
|
panic(err.Error())
|
|
}
|
|
|
|
var result = emptyIpv6
|
|
ifaceaddrs, err := niface.Addrs()
|
|
|
|
for _, n := range ifaceaddrs {
|
|
tip, _, err := net.ParseCIDR(n.String())
|
|
if err != nil {
|
|
break
|
|
}
|
|
if IsIPv6(tip.String()) {
|
|
if tip.IsGlobalUnicast() {
|
|
result = tip
|
|
_, tnet, _ := net.ParseCIDR("fc00::/7")
|
|
if !tnet.Contains(tip) {
|
|
break
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
for {
|
|
n := <-requests
|
|
if filter != nil {
|
|
ok := false
|
|
for _, i := range filter {
|
|
if i.Contains(n.answeringForIP) {
|
|
fmt.Println("filter allowed IP", n.answeringForIP)
|
|
ok = true
|
|
break
|
|
}
|
|
}
|
|
if !ok {
|
|
continue
|
|
}
|
|
}
|
|
|
|
if n.sourceIface == iface {
|
|
pkt(result, n.srcIP, n.answeringForIP, niface.HardwareAddr, respondType)
|
|
} else {
|
|
if !bytes.Equal(n.mac, n.receivedIfaceMac) {
|
|
pkt(n.srcIP, n.dstIP, n.answeringForIP, niface.HardwareAddr, respondType)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
func pkt(ownIP []byte, dstIP []byte, tgtip []byte, mac []byte, respondType NDPType) {
|
|
v6, err := newIpv6Header(ownIP, dstIP)
|
|
if err != nil {
|
|
return
|
|
}
|
|
NDPa, err := newNdpPacket(tgtip, mac, respondType)
|
|
if err != nil {
|
|
return
|
|
}
|
|
v6.addPayload(NDPa)
|
|
response := v6.constructPacket()
|
|
|
|
var t [16]byte
|
|
copy(t[:], dstIP)
|
|
|
|
d := syscall.SockaddrInet6{
|
|
Port: 0,
|
|
Addr: t,
|
|
}
|
|
if GlobalDebug {
|
|
fmt.Println("Sending packet of type", respondType, "to")
|
|
fmt.Printf("% X\n", t)
|
|
}
|
|
err = syscall.Sendto(globalFd, response, 0, &d)
|
|
if err != nil {
|
|
fmt.Println(err.Error())
|
|
}
|
|
}
|