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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build darwin dragonfly freebsd netbsd openbsd
package net
import (
"os"
"syscall"
"unsafe"
)
// If the ifindex is zero, interfaceTable returns mappings of all
// network interfaces. Otherwise it returns a mapping of a specific
// interface.
func interfaceTable(ifindex int) ([]Interface, error) {
tab, err := syscall.RouteRIB(syscall.NET_RT_IFLIST, ifindex)
if err != nil {
return nil, os.NewSyscallError("route rib", err)
}
msgs, err := syscall.ParseRoutingMessage(tab)
if err != nil {
return nil, os.NewSyscallError("route message", err)
}
return parseInterfaceTable(ifindex, msgs)
}
func parseInterfaceTable(ifindex int, msgs []syscall.RoutingMessage) ([]Interface, error) {
var ift []Interface
loop:
for _, m := range msgs {
switch m := m.(type) {
case *syscall.InterfaceMessage:
if ifindex == 0 || ifindex == int(m.Header.Index) {
ifi, err := newLink(m)
if err != nil {
return nil, err
}
ift = append(ift, *ifi)
if ifindex == int(m.Header.Index) {
break loop
}
}
}
}
return ift, nil
}
func newLink(m *syscall.InterfaceMessage) (*Interface, error) {
sas, err := syscall.ParseRoutingSockaddr(m)
if err != nil {
return nil, os.NewSyscallError("route sockaddr", err)
}
ifi := &Interface{Index: int(m.Header.Index), Flags: linkFlags(m.Header.Flags)}
for _, sa := range sas {
switch sa := sa.(type) {
case *syscall.SockaddrDatalink:
// NOTE: SockaddrDatalink.Data is minimum work area,
// can be larger.
m.Data = m.Data[unsafe.Offsetof(sa.Data):]
var name [syscall.IFNAMSIZ]byte
for i := 0; i < int(sa.Nlen); i++ {
name[i] = byte(m.Data[i])
}
ifi.Name = string(name[:sa.Nlen])
ifi.MTU = int(m.Header.Data.Mtu)
addr := make([]byte, sa.Alen)
for i := 0; i < int(sa.Alen); i++ {
addr[i] = byte(m.Data[int(sa.Nlen)+i])
}
ifi.HardwareAddr = addr[:sa.Alen]
}
}
return ifi, nil
}
func linkFlags(rawFlags int32) Flags {
var f Flags
if rawFlags&syscall.IFF_UP != 0 {
f |= FlagUp
}
if rawFlags&syscall.IFF_BROADCAST != 0 {
f |= FlagBroadcast
}
if rawFlags&syscall.IFF_LOOPBACK != 0 {
f |= FlagLoopback
}
if rawFlags&syscall.IFF_POINTOPOINT != 0 {
f |= FlagPointToPoint
}
if rawFlags&syscall.IFF_MULTICAST != 0 {
f |= FlagMulticast
}
return f
}
// If the ifi is nil, interfaceAddrTable returns addresses for all
// network interfaces. Otherwise it returns addresses for a specific
// interface.
func interfaceAddrTable(ifi *Interface) ([]Addr, error) {
index := 0
if ifi != nil {
index = ifi.Index
}
tab, err := syscall.RouteRIB(syscall.NET_RT_IFLIST, index)
if err != nil {
return nil, os.NewSyscallError("route rib", err)
}
msgs, err := syscall.ParseRoutingMessage(tab)
if err != nil {
return nil, os.NewSyscallError("route message", err)
}
var ift []Interface
if index == 0 {
ift, err = parseInterfaceTable(index, msgs)
if err != nil {
return nil, err
}
}
var ifat []Addr
for _, m := range msgs {
switch m := m.(type) {
case *syscall.InterfaceAddrMessage:
if index == 0 || index == int(m.Header.Index) {
if index == 0 {
var err error
ifi, err = interfaceByIndex(ift, int(m.Header.Index))
if err != nil {
return nil, err
}
}
ifa, err := newAddr(ifi, m)
if err != nil {
return nil, err
}
if ifa != nil {
ifat = append(ifat, ifa)
}
}
}
}
return ifat, nil
}
func newAddr(ifi *Interface, m *syscall.InterfaceAddrMessage) (Addr, error) {
sas, err := syscall.ParseRoutingSockaddr(m)
if err != nil {
return nil, os.NewSyscallError("route sockaddr", err)
}
ifa := &IPNet{}
for i, sa := range sas {
switch sa := sa.(type) {
case *syscall.SockaddrInet4:
switch i {
case 0:
ifa.Mask = IPv4Mask(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])
case 1:
ifa.IP = IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])
}
case *syscall.SockaddrInet6:
switch i {
case 0:
ifa.Mask = make(IPMask, IPv6len)
copy(ifa.Mask, sa.Addr[:])
case 1:
ifa.IP = make(IP, IPv6len)
copy(ifa.IP, sa.Addr[:])
// NOTE: KAME based IPv6 protcol stack usually embeds
// the interface index in the interface-local or link-
// local address as the kernel-internal form.
if ifa.IP.IsLinkLocalUnicast() {
ifa.IP[2], ifa.IP[3] = 0, 0
}
}
default: // Sockaddrs contain syscall.SockaddrDatalink on NetBSD
return nil, nil
}
}
return ifa, nil
}
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