+++ /dev/null
-// Copyright 2015 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.
-
-package icmp
-
-import (
- "encoding/binary"
- "net"
- "strings"
-
- "golang.org/x/net/internal/iana"
-)
-
-const (
- classInterfaceInfo = 2
-
- afiIPv4 = 1
- afiIPv6 = 2
-)
-
-const (
- attrMTU = 1 << iota
- attrName
- attrIPAddr
- attrIfIndex
-)
-
-// An InterfaceInfo represents interface and next-hop identification.
-type InterfaceInfo struct {
- Class int // extension object class number
- Type int // extension object sub-type
- Interface *net.Interface
- Addr *net.IPAddr
-}
-
-func (ifi *InterfaceInfo) nameLen() int {
- if len(ifi.Interface.Name) > 63 {
- return 64
- }
- l := 1 + len(ifi.Interface.Name)
- return (l + 3) &^ 3
-}
-
-func (ifi *InterfaceInfo) attrsAndLen(proto int) (attrs, l int) {
- l = 4
- if ifi.Interface != nil && ifi.Interface.Index > 0 {
- attrs |= attrIfIndex
- l += 4
- if len(ifi.Interface.Name) > 0 {
- attrs |= attrName
- l += ifi.nameLen()
- }
- if ifi.Interface.MTU > 0 {
- attrs |= attrMTU
- l += 4
- }
- }
- if ifi.Addr != nil {
- switch proto {
- case iana.ProtocolICMP:
- if ifi.Addr.IP.To4() != nil {
- attrs |= attrIPAddr
- l += 4 + net.IPv4len
- }
- case iana.ProtocolIPv6ICMP:
- if ifi.Addr.IP.To16() != nil && ifi.Addr.IP.To4() == nil {
- attrs |= attrIPAddr
- l += 4 + net.IPv6len
- }
- }
- }
- return
-}
-
-// Len implements the Len method of Extension interface.
-func (ifi *InterfaceInfo) Len(proto int) int {
- _, l := ifi.attrsAndLen(proto)
- return l
-}
-
-// Marshal implements the Marshal method of Extension interface.
-func (ifi *InterfaceInfo) Marshal(proto int) ([]byte, error) {
- attrs, l := ifi.attrsAndLen(proto)
- b := make([]byte, l)
- if err := ifi.marshal(proto, b, attrs, l); err != nil {
- return nil, err
- }
- return b, nil
-}
-
-func (ifi *InterfaceInfo) marshal(proto int, b []byte, attrs, l int) error {
- binary.BigEndian.PutUint16(b[:2], uint16(l))
- b[2], b[3] = classInterfaceInfo, byte(ifi.Type)
- for b = b[4:]; len(b) > 0 && attrs != 0; {
- switch {
- case attrs&attrIfIndex != 0:
- b = ifi.marshalIfIndex(proto, b)
- attrs &^= attrIfIndex
- case attrs&attrIPAddr != 0:
- b = ifi.marshalIPAddr(proto, b)
- attrs &^= attrIPAddr
- case attrs&attrName != 0:
- b = ifi.marshalName(proto, b)
- attrs &^= attrName
- case attrs&attrMTU != 0:
- b = ifi.marshalMTU(proto, b)
- attrs &^= attrMTU
- }
- }
- return nil
-}
-
-func (ifi *InterfaceInfo) marshalIfIndex(proto int, b []byte) []byte {
- binary.BigEndian.PutUint32(b[:4], uint32(ifi.Interface.Index))
- return b[4:]
-}
-
-func (ifi *InterfaceInfo) parseIfIndex(b []byte) ([]byte, error) {
- if len(b) < 4 {
- return nil, errMessageTooShort
- }
- ifi.Interface.Index = int(binary.BigEndian.Uint32(b[:4]))
- return b[4:], nil
-}
-
-func (ifi *InterfaceInfo) marshalIPAddr(proto int, b []byte) []byte {
- switch proto {
- case iana.ProtocolICMP:
- binary.BigEndian.PutUint16(b[:2], uint16(afiIPv4))
- copy(b[4:4+net.IPv4len], ifi.Addr.IP.To4())
- b = b[4+net.IPv4len:]
- case iana.ProtocolIPv6ICMP:
- binary.BigEndian.PutUint16(b[:2], uint16(afiIPv6))
- copy(b[4:4+net.IPv6len], ifi.Addr.IP.To16())
- b = b[4+net.IPv6len:]
- }
- return b
-}
-
-func (ifi *InterfaceInfo) parseIPAddr(b []byte) ([]byte, error) {
- if len(b) < 4 {
- return nil, errMessageTooShort
- }
- afi := int(binary.BigEndian.Uint16(b[:2]))
- b = b[4:]
- switch afi {
- case afiIPv4:
- if len(b) < net.IPv4len {
- return nil, errMessageTooShort
- }
- ifi.Addr.IP = make(net.IP, net.IPv4len)
- copy(ifi.Addr.IP, b[:net.IPv4len])
- b = b[net.IPv4len:]
- case afiIPv6:
- if len(b) < net.IPv6len {
- return nil, errMessageTooShort
- }
- ifi.Addr.IP = make(net.IP, net.IPv6len)
- copy(ifi.Addr.IP, b[:net.IPv6len])
- b = b[net.IPv6len:]
- }
- return b, nil
-}
-
-func (ifi *InterfaceInfo) marshalName(proto int, b []byte) []byte {
- l := byte(ifi.nameLen())
- b[0] = l
- copy(b[1:], []byte(ifi.Interface.Name))
- return b[l:]
-}
-
-func (ifi *InterfaceInfo) parseName(b []byte) ([]byte, error) {
- if 4 > len(b) || len(b) < int(b[0]) {
- return nil, errMessageTooShort
- }
- l := int(b[0])
- if l%4 != 0 || 4 > l || l > 64 {
- return nil, errInvalidExtension
- }
- var name [63]byte
- copy(name[:], b[1:l])
- ifi.Interface.Name = strings.Trim(string(name[:]), "\000")
- return b[l:], nil
-}
-
-func (ifi *InterfaceInfo) marshalMTU(proto int, b []byte) []byte {
- binary.BigEndian.PutUint32(b[:4], uint32(ifi.Interface.MTU))
- return b[4:]
-}
-
-func (ifi *InterfaceInfo) parseMTU(b []byte) ([]byte, error) {
- if len(b) < 4 {
- return nil, errMessageTooShort
- }
- ifi.Interface.MTU = int(binary.BigEndian.Uint32(b[:4]))
- return b[4:], nil
-}
-
-func parseInterfaceInfo(b []byte) (Extension, error) {
- ifi := &InterfaceInfo{
- Class: int(b[2]),
- Type: int(b[3]),
- }
- if ifi.Type&(attrIfIndex|attrName|attrMTU) != 0 {
- ifi.Interface = &net.Interface{}
- }
- if ifi.Type&attrIPAddr != 0 {
- ifi.Addr = &net.IPAddr{}
- }
- attrs := ifi.Type & (attrIfIndex | attrIPAddr | attrName | attrMTU)
- for b = b[4:]; len(b) > 0 && attrs != 0; {
- var err error
- switch {
- case attrs&attrIfIndex != 0:
- b, err = ifi.parseIfIndex(b)
- attrs &^= attrIfIndex
- case attrs&attrIPAddr != 0:
- b, err = ifi.parseIPAddr(b)
- attrs &^= attrIPAddr
- case attrs&attrName != 0:
- b, err = ifi.parseName(b)
- attrs &^= attrName
- case attrs&attrMTU != 0:
- b, err = ifi.parseMTU(b)
- attrs &^= attrMTU
- }
- if err != nil {
- return nil, err
- }
- }
- if ifi.Interface != nil && ifi.Interface.Name != "" && ifi.Addr != nil && ifi.Addr.IP.To16() != nil && ifi.Addr.IP.To4() == nil {
- ifi.Addr.Zone = ifi.Interface.Name
- }
- return ifi, nil
-}
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