forked from mandelsoft/kubelink
/
helper.go
87 lines (73 loc) · 2.41 KB
/
helper.go
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/*
* Copyright 2020 Mandelsoft. All rights reserved.
* This file is licensed under the Apache Software License, v. 2 except as noted
* otherwise in the LICENSE file
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package play
import (
"fmt"
"io"
"log"
"net"
"github.com/vishvananda/netlink"
"golang.org/x/net/ipv4"
"golang.org/x/net/ipv6"
"github.com/mandelsoft/kubelink/pkg"
)
const ROUTE = "192.168.3.0/24"
const TUNIP = "192.168.1.2"
const TUNCIDR = TUNIP + "/24"
func ConfigureTun(name string) {
link, err := netlink.LinkByName(name)
pkg.ExitOnErr("cannot get link %q", name, err)
addr, err := netlink.ParseAddr(TUNCIDR)
pkg.ExitOnErr("cannot create addr %q", TUNCIDR, err)
err = netlink.AddrAdd(link, addr)
pkg.ExitOnErr("cannot add addr %q", TUNCIDR, err)
err = netlink.LinkSetUp(link)
pkg.ExitOnErr("cannot bring up %q", name, err)
_, dst, err := net.ParseCIDR(ROUTE)
pkg.ExitOnErr("cannot parse cidr %q", ROUTE, err)
route := &netlink.Route{LinkIndex: link.Attrs().Index, Dst: dst}
err = netlink.RouteAdd(route)
pkg.ExitOnErr("cannot add route", err)
}
func TraceTun(fd io.Reader) {
buffer := [2000]byte{}
for {
n, err := fd.Read(buffer[:])
if n <= 0 || err != nil {
fmt.Printf("END: %d bytes, err=%s\n", n, err)
break
}
log.Printf("Read %d bytes", n)
vers := int(buffer[0]) >> 4
if vers == ipv6.Version {
header, err := ipv6.ParseHeader(buffer[:n])
if err != nil {
fmt.Printf("err: %s\n", err)
} else {
fmt.Printf("ipv6[%d]: (%d) hdr: %d, payload: %d, prot: %d, %s->%s\n", header.Version, n, 40, header.PayloadLen, header.NextHeader, header.Src, header.Dst)
}
} else {
header, err := ipv4.ParseHeader(buffer[:n])
if err != nil {
fmt.Printf("err: %s\n", err)
} else {
fmt.Printf("ipv4[%d]: (%d) hdr: %d, total: %d, prot: %d, %s->%s\n", header.Version, n, header.Len, header.TotalLen, header.Protocol, header.Src, header.Dst)
}
}
}
}