status-go/vendor/github.com/libp2p/go-netroute/netroute_bsd.go

154 lines
3.7 KiB
Go

// Copyright 2012 Google, Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style license
// that can be found in the LICENSE file in the root of the source
// tree.
// +build darwin dragonfly freebsd netbsd openbsd
// This is a BSD import for the routing structure initially found in
// https://github.com/google/gopacket/blob/master/routing/routing.go
//RIB parsing follows the BSD route format described in
// https://github.com/freebsd/freebsd/blob/master/sys/net/route.h
package netroute
import (
"fmt"
"net"
"sort"
"syscall"
"github.com/google/gopacket/routing"
"golang.org/x/net/route"
)
func toIPAddr(a route.Addr) (net.IP, error) {
switch t := a.(type) {
case *route.Inet4Addr:
ip := net.IPv4(t.IP[0], t.IP[1], t.IP[2], t.IP[3])
return ip, nil
case *route.Inet6Addr:
ip := make(net.IP, net.IPv6len)
copy(ip, t.IP[:])
return ip, nil
default:
return net.IP{}, fmt.Errorf("unknown family: %v", t)
}
}
// selected BSD Route flags.
const (
RTF_UP = 0x1
RTF_GATEWAY = 0x2
RTF_HOST = 0x4
RTF_REJECT = 0x8
RTF_DYNAMIC = 0x10
RTF_MODIFIED = 0x20
RTF_STATIC = 0x800
RTF_BLACKHOLE = 0x1000
RTF_LOCAL = 0x200000
RTF_BROADCAST = 0x400000
RTF_MULTICAST = 0x800000
)
func New() (routing.Router, error) {
rtr := &router{}
rtr.ifaces = make(map[int]net.Interface)
rtr.addrs = make(map[int]ipAddrs)
tab, err := route.FetchRIB(syscall.AF_UNSPEC, route.RIBTypeRoute, 0)
if err != nil {
return nil, err
}
msgs, err := route.ParseRIB(route.RIBTypeRoute, tab)
if err != nil {
return nil, err
}
var ipn *net.IPNet
for _, msg := range msgs {
m := msg.(*route.RouteMessage)
routeInfo := new(rtInfo)
if m.Version < 3 || m.Version > 5 {
return nil, fmt.Errorf("Unexpected RIB message version: %d", m.Version)
}
if m.Type != 4 /* RTM_GET */ {
return nil, fmt.Errorf("Unexpected RIB message type: %d", m.Type)
}
if m.Flags&RTF_UP == 0 ||
m.Flags&(RTF_REJECT|RTF_BLACKHOLE) != 0 {
continue
}
if m.Err != nil {
continue
}
dst, err := toIPAddr(m.Addrs[0])
if err == nil {
mask, _ := toIPAddr(m.Addrs[2])
if mask == nil {
mask = net.IP(net.CIDRMask(0, 8*len(dst)))
}
ipn = &net.IPNet{IP: dst, Mask: net.IPMask(mask)}
if m.Flags&RTF_HOST != 0 {
ipn.Mask = net.CIDRMask(8*len(ipn.IP), 8*len(ipn.IP))
}
routeInfo.Dst = ipn
} else {
return nil, fmt.Errorf("Unexpected RIB destination: %v", err)
}
if m.Flags&RTF_GATEWAY != 0 {
if gw, err := toIPAddr(m.Addrs[1]); err == nil {
routeInfo.Gateway = gw
}
}
if src, err := toIPAddr(m.Addrs[5]); err == nil {
ipn = &net.IPNet{IP: src, Mask: net.CIDRMask(8*len(src), 8*len(src))}
routeInfo.Src = ipn
routeInfo.PrefSrc = src
if m.Flags&0x2 != 0 /* RTF_GATEWAY */ {
routeInfo.Src.Mask = net.CIDRMask(0, 8*len(routeInfo.Src.IP))
}
}
routeInfo.OutputIface = uint32(m.Index)
switch m.Addrs[0].(type) {
case *route.Inet4Addr:
rtr.v4 = append(rtr.v4, routeInfo)
case *route.Inet6Addr:
rtr.v6 = append(rtr.v6, routeInfo)
}
}
sort.Sort(rtr.v4)
sort.Sort(rtr.v6)
ifaces, err := net.Interfaces()
if err != nil {
return nil, err
}
for _, iface := range ifaces {
rtr.ifaces[iface.Index] = iface
var addrs ipAddrs
ifaceAddrs, err := iface.Addrs()
if err != nil {
return nil, err
}
for _, addr := range ifaceAddrs {
if inet, ok := addr.(*net.IPNet); ok {
// Go has a nasty habit of giving you IPv4s as ::ffff:1.2.3.4 instead of 1.2.3.4.
// We want to use mapped v4 addresses as v4 preferred addresses, never as v6
// preferred addresses.
if v4 := inet.IP.To4(); v4 != nil {
if addrs.v4 == nil {
addrs.v4 = v4
}
} else if addrs.v6 == nil {
addrs.v6 = inet.IP
}
}
}
rtr.addrs[iface.Index] = addrs
}
return rtr, nil
}