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// Copyright 2017 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 aix darwin dragonfly freebsd linux netbsd openbsd solaris windows zos
package socket
import (
"encoding/binary"
"errors"
"net"
"runtime"
"strconv"
"sync"
"time"
)
func marshalInetAddr(a net.Addr) []byte {
switch a := a.(type) {
case *net.TCPAddr:
return marshalSockaddr(a.IP, a.Port, a.Zone)
case *net.UDPAddr:
return marshalSockaddr(a.IP, a.Port, a.Zone)
case *net.IPAddr:
return marshalSockaddr(a.IP, 0, a.Zone)
default:
return nil
}
}
func marshalSockaddr(ip net.IP, port int, zone string) []byte {
if ip4 := ip.To4(); ip4 != nil {
b := make([]byte, sizeofSockaddrInet)
switch runtime.GOOS {
case "android", "illumos", "linux", "solaris", "windows":
NativeEndian.PutUint16(b[:2], uint16(sysAF_INET))
default:
b[0] = sizeofSockaddrInet
b[1] = sysAF_INET
}
binary.BigEndian.PutUint16(b[2:4], uint16(port))
copy(b[4:8], ip4)
return b
}
if ip6 := ip.To16(); ip6 != nil && ip.To4() == nil {
b := make([]byte, sizeofSockaddrInet6)
switch runtime.GOOS {
case "android", "illumos", "linux", "solaris", "windows":
NativeEndian.PutUint16(b[:2], uint16(sysAF_INET6))
default:
b[0] = sizeofSockaddrInet6
b[1] = sysAF_INET6
}
binary.BigEndian.PutUint16(b[2:4], uint16(port))
copy(b[8:24], ip6)
if zone != "" {
NativeEndian.PutUint32(b[24:28], uint32(zoneCache.index(zone)))
}
return b
}
return nil
}
func parseInetAddr(b []byte, network string) (net.Addr, error) {
if len(b) < 2 {
return nil, errors.New("invalid address")
}
var af int
switch runtime.GOOS {
case "android", "illumos", "linux", "solaris", "windows":
af = int(NativeEndian.Uint16(b[:2]))
default:
af = int(b[1])
}
var ip net.IP
var zone string
if af == sysAF_INET {
if len(b) < sizeofSockaddrInet {
return nil, errors.New("short address")
}
ip = make(net.IP, net.IPv4len)
copy(ip, b[4:8])
}
if af == sysAF_INET6 {
if len(b) < sizeofSockaddrInet6 {
return nil, errors.New("short address")
}
ip = make(net.IP, net.IPv6len)
copy(ip, b[8:24])
if id := int(NativeEndian.Uint32(b[24:28])); id > 0 {
zone = zoneCache.name(id)
}
}
switch network {
case "tcp", "tcp4", "tcp6":
return &net.TCPAddr{IP: ip, Port: int(binary.BigEndian.Uint16(b[2:4])), Zone: zone}, nil
case "udp", "udp4", "udp6":
return &net.UDPAddr{IP: ip, Port: int(binary.BigEndian.Uint16(b[2:4])), Zone: zone}, nil
default:
return &net.IPAddr{IP: ip, Zone: zone}, nil
}
}
// An ipv6ZoneCache represents a cache holding partial network
// interface information. It is used for reducing the cost of IPv6
// addressing scope zone resolution.
//
// Multiple names sharing the index are managed by first-come
// first-served basis for consistency.
type ipv6ZoneCache struct {
sync.RWMutex // guard the following
lastFetched time.Time // last time routing information was fetched
toIndex map[string]int // interface name to its index
toName map[int]string // interface index to its name
}
var zoneCache = ipv6ZoneCache{
toIndex: make(map[string]int),
toName: make(map[int]string),
}
// update refreshes the network interface information if the cache was last
// updated more than 1 minute ago, or if force is set. It returns whether the
// cache was updated.
func (zc *ipv6ZoneCache) update(ift []net.Interface, force bool) (updated bool) {
zc.Lock()
defer zc.Unlock()
now := time.Now()
if !force && zc.lastFetched.After(now.Add(-60*time.Second)) {
return false
}
zc.lastFetched = now
if len(ift) == 0 {
var err error
if ift, err = net.Interfaces(); err != nil {
return false
}
}
zc.toIndex = make(map[string]int, len(ift))
zc.toName = make(map[int]string, len(ift))
for _, ifi := range ift {
zc.toIndex[ifi.Name] = ifi.Index
if _, ok := zc.toName[ifi.Index]; !ok {
zc.toName[ifi.Index] = ifi.Name
}
}
return true
}
func (zc *ipv6ZoneCache) name(zone int) string {
updated := zoneCache.update(nil, false)
zoneCache.RLock()
name, ok := zoneCache.toName[zone]
zoneCache.RUnlock()
if !ok && !updated {
zoneCache.update(nil, true)
zoneCache.RLock()
name, ok = zoneCache.toName[zone]
zoneCache.RUnlock()
}
if !ok { // last resort
name = strconv.Itoa(zone)
}
return name
}
func (zc *ipv6ZoneCache) index(zone string) int {
updated := zoneCache.update(nil, false)
zoneCache.RLock()
index, ok := zoneCache.toIndex[zone]
zoneCache.RUnlock()
if !ok && !updated {
zoneCache.update(nil, true)
zoneCache.RLock()
index, ok = zoneCache.toIndex[zone]
zoneCache.RUnlock()
}
if !ok { // last resort
index, _ = strconv.Atoi(zone)
}
return index
}
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