| // 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 go1.9 |
| // +build darwin dragonfly freebsd linux netbsd openbsd solaris windows |
| |
| 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", "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", "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", "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), |
| } |
| |
| func (zc *ipv6ZoneCache) update(ift []net.Interface) { |
| zc.Lock() |
| defer zc.Unlock() |
| now := time.Now() |
| if zc.lastFetched.After(now.Add(-60 * time.Second)) { |
| return |
| } |
| zc.lastFetched = now |
| if len(ift) == 0 { |
| var err error |
| if ift, err = net.Interfaces(); err != nil { |
| return |
| } |
| } |
| 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 |
| } |
| } |
| } |
| |
| func (zc *ipv6ZoneCache) name(zone int) string { |
| zoneCache.update(nil) |
| zoneCache.RLock() |
| defer zoneCache.RUnlock() |
| name, ok := zoneCache.toName[zone] |
| if !ok { |
| name = strconv.Itoa(zone) |
| } |
| return name |
| } |
| |
| func (zc *ipv6ZoneCache) index(zone string) int { |
| zoneCache.update(nil) |
| zoneCache.RLock() |
| defer zoneCache.RUnlock() |
| index, ok := zoneCache.toIndex[zone] |
| if !ok { |
| index, _ = strconv.Atoi(zone) |
| } |
| return index |
| } |