icmp: add extensions for interface and next-hop identification
This change implements ICMP extensions for interface and next-hop
identification which are used for route trace applications as described
in RFC 5837.
Change-Id: I2435109b5e766e743b894b0280a537324975489d
Reviewed-on: https://go-review.googlesource.com/3112
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/icmp/extension.go b/icmp/extension.go
index 37af0e1..720e167 100644
--- a/icmp/extension.go
+++ b/icmp/extension.go
@@ -74,6 +74,12 @@
return nil, -1, err
}
exts = append(exts, ext)
+ case classInterfaceInfo:
+ ext, err := parseInterfaceInfo(b[:ol])
+ if err != nil {
+ return nil, -1, err
+ }
+ exts = append(exts, ext)
}
b = b[ol:]
}
diff --git a/icmp/extension_test.go b/icmp/extension_test.go
index 6ed9e70..488c36b 100644
--- a/icmp/extension_test.go
+++ b/icmp/extension_test.go
@@ -5,6 +5,7 @@
package icmp
import (
+ "net"
"reflect"
"testing"
@@ -90,6 +91,78 @@
},
},
},
+ // Interface information with no attribute
+ {
+ proto: iana.ProtocolICMP,
+ hdr: []byte{
+ 0x20, 0x00, 0x00, 0x00,
+ },
+ obj: []byte{
+ 0x00, 0x04, 0x02, 0x00,
+ },
+ exts: []Extension{
+ &InterfaceInfo{
+ Class: classInterfaceInfo,
+ },
+ },
+ },
+ // Interface information with ifIndex and name
+ {
+ proto: iana.ProtocolICMP,
+ hdr: []byte{
+ 0x20, 0x00, 0x00, 0x00,
+ },
+ obj: []byte{
+ 0x00, 0x10, 0x02, 0x0a,
+ 0x00, 0x00, 0x00, 0x10,
+ 0x08, byte('e'), byte('n'), byte('1'),
+ byte('0'), byte('1'), 0x00, 0x00,
+ },
+ exts: []Extension{
+ &InterfaceInfo{
+ Class: classInterfaceInfo,
+ Type: 0x0a,
+ Interface: &net.Interface{
+ Index: 16,
+ Name: "en101",
+ },
+ },
+ },
+ },
+ // Interface information with ifIndex, IPAddr, name and MTU
+ {
+ proto: iana.ProtocolIPv6ICMP,
+ hdr: []byte{
+ 0x20, 0x00, 0x00, 0x00,
+ },
+ obj: []byte{
+ 0x00, 0x28, 0x02, 0x0f,
+ 0x00, 0x00, 0x00, 0x0f,
+ 0x00, 0x02, 0x00, 0x00,
+ 0xfe, 0x80, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x01,
+ 0x08, byte('e'), byte('n'), byte('1'),
+ byte('0'), byte('1'), 0x00, 0x00,
+ 0x00, 0x00, 0x20, 0x00,
+ },
+ exts: []Extension{
+ &InterfaceInfo{
+ Class: classInterfaceInfo,
+ Type: 0x0f,
+ Interface: &net.Interface{
+ Index: 15,
+ Name: "en101",
+ MTU: 8192,
+ },
+ Addr: &net.IPAddr{
+ IP: net.ParseIP("fe80::1"),
+ Zone: "en101",
+ },
+ },
+ },
+ },
}
func TestMarshalAndParseExtension(t *testing.T) {
@@ -104,6 +177,12 @@
t.Errorf("#%v/%v: %v", i, j, err)
continue
}
+ case *InterfaceInfo:
+ b, err = ext.Marshal(tt.proto)
+ if err != nil {
+ t.Errorf("#%v/%v: %v", i, j, err)
+ continue
+ }
}
if !reflect.DeepEqual(b, tt.obj) {
t.Errorf("#%v/%v: got %#v; want %#v", i, j, b, tt.obj)
@@ -149,6 +228,9 @@
case *MPLSLabelStack:
want := tt.exts[j].(*MPLSLabelStack)
t.Errorf("#%v/%v: got %#v; want %#v", i, j, ext, want)
+ case *InterfaceInfo:
+ want := tt.exts[j].(*InterfaceInfo)
+ t.Errorf("#%v/%v: got %#v; want %#v", i, j, ext, want)
}
}
continue
diff --git a/icmp/interface.go b/icmp/interface.go
new file mode 100644
index 0000000..806b26b
--- /dev/null
+++ b/icmp/interface.go
@@ -0,0 +1,232 @@
+// 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 (
+ "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 {
+ b[0], b[1] = byte(l>>8), byte(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 {
+ b[0], b[1], b[2], b[3] = byte(ifi.Interface.Index>>24), byte(ifi.Interface.Index>>16), byte(ifi.Interface.Index>>8), byte(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(b[0])<<24 | int(b[1])<<16 | int(b[2])<<8 | int(b[3])
+ return b[4:], nil
+}
+
+func (ifi *InterfaceInfo) marshalIPAddr(proto int, b []byte) []byte {
+ switch proto {
+ case iana.ProtocolICMP:
+ b[0], b[1] = byte(afiIPv4>>8), byte(afiIPv4)
+ copy(b[4:4+net.IPv4len], ifi.Addr.IP.To4())
+ b = b[4+net.IPv4len:]
+ case iana.ProtocolIPv6ICMP:
+ b[0], b[1] = byte(afiIPv6>>8), byte(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(b[0])<<8 | int(b[1])
+ 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])
+ 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 {
+ b[0], b[1], b[2], b[3] = byte(ifi.Interface.MTU>>24), byte(ifi.Interface.MTU>>16), byte(ifi.Interface.MTU>>8), byte(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(b[0])<<24 | int(b[1])<<16 | int(b[2])<<8 | int(b[3])
+ 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
+}
diff --git a/icmp/message.go b/icmp/message.go
index 13b57f7..654c519 100644
--- a/icmp/message.go
+++ b/icmp/message.go
@@ -9,6 +9,8 @@
// ICMPv4 and ICMPv6 are defined in RFC 792 and RFC 4443.
// Multi-part message support for ICMP is defined in RFC 4884.
// ICMP extensions for MPLS are defined in RFC 4950.
+// ICMP extensions for interface and next-hop identification are
+// defined in RFC 5837.
package icmp // import "golang.org/x/net/icmp"
import (
diff --git a/icmp/multipart.go b/icmp/multipart.go
index 3f89a76..54ac8bc 100644
--- a/icmp/multipart.go
+++ b/icmp/multipart.go
@@ -65,6 +65,12 @@
return nil, err
}
off += ext.Len(proto)
+ case *InterfaceInfo:
+ attrs, l := ext.attrsAndLen(proto)
+ if err := ext.marshal(proto, b[off:], attrs, l); err != nil {
+ return nil, err
+ }
+ off += ext.Len(proto)
}
}
s := checksum(b[dataLen+4:])
diff --git a/icmp/multipart_test.go b/icmp/multipart_test.go
index 505db86..9248e47 100644
--- a/icmp/multipart_test.go
+++ b/icmp/multipart_test.go
@@ -34,6 +34,18 @@
},
},
},
+ &icmp.InterfaceInfo{
+ Class: 2,
+ Type: 0x0f,
+ Interface: &net.Interface{
+ Index: 15,
+ Name: "en101",
+ MTU: 8192,
+ },
+ Addr: &net.IPAddr{
+ IP: net.IPv4(192, 168, 0, 1).To4(),
+ },
+ },
},
},
},
@@ -42,6 +54,18 @@
Body: &icmp.TimeExceeded{
Data: []byte("ERROR-INVOKING-PACKET"),
Extensions: []icmp.Extension{
+ &icmp.InterfaceInfo{
+ Class: 2,
+ Type: 0x0f,
+ Interface: &net.Interface{
+ Index: 15,
+ Name: "en101",
+ MTU: 8192,
+ },
+ Addr: &net.IPAddr{
+ IP: net.IPv4(192, 168, 0, 1).To4(),
+ },
+ },
&icmp.MPLSLabelStack{
Class: 1,
Type: 1,
@@ -75,6 +99,30 @@
},
},
},
+ &icmp.InterfaceInfo{
+ Class: 2,
+ Type: 0x0f,
+ Interface: &net.Interface{
+ Index: 15,
+ Name: "en101",
+ MTU: 8192,
+ },
+ Addr: &net.IPAddr{
+ IP: net.IPv4(192, 168, 0, 1).To4(),
+ },
+ },
+ &icmp.InterfaceInfo{
+ Class: 2,
+ Type: 0x2f,
+ Interface: &net.Interface{
+ Index: 16,
+ Name: "en102",
+ MTU: 8192,
+ },
+ Addr: &net.IPAddr{
+ IP: net.IPv4(192, 168, 0, 2).To4(),
+ },
+ },
},
},
},
@@ -100,7 +148,7 @@
case ipv4.ICMPTypeDestinationUnreachable:
got, want := m.Body.(*icmp.DstUnreach), tt.Body.(*icmp.DstUnreach)
if !reflect.DeepEqual(got.Extensions, want.Extensions) {
- t.Errorf("#%v: got %#v; want %#v", i, got.Extensions, want.Extensions)
+ t.Error(dumpExtensions(i, got.Extensions, want.Extensions))
}
if len(got.Data) != 128 {
t.Errorf("#%v: got %v; want 128", i, len(got.Data))
@@ -143,6 +191,19 @@
},
},
},
+ &icmp.InterfaceInfo{
+ Class: 2,
+ Type: 0x0f,
+ Interface: &net.Interface{
+ Index: 15,
+ Name: "en101",
+ MTU: 8192,
+ },
+ Addr: &net.IPAddr{
+ IP: net.ParseIP("fe80::1"),
+ Zone: "en101",
+ },
+ },
},
},
},
@@ -151,6 +212,19 @@
Body: &icmp.TimeExceeded{
Data: []byte("ERROR-INVOKING-PACKET"),
Extensions: []icmp.Extension{
+ &icmp.InterfaceInfo{
+ Class: 2,
+ Type: 0x0f,
+ Interface: &net.Interface{
+ Index: 15,
+ Name: "en101",
+ MTU: 8192,
+ },
+ Addr: &net.IPAddr{
+ IP: net.ParseIP("fe80::1"),
+ Zone: "en101",
+ },
+ },
&icmp.MPLSLabelStack{
Class: 1,
Type: 1,
@@ -163,6 +237,19 @@
},
},
},
+ &icmp.InterfaceInfo{
+ Class: 2,
+ Type: 0x2f,
+ Interface: &net.Interface{
+ Index: 16,
+ Name: "en102",
+ MTU: 8192,
+ },
+ Addr: &net.IPAddr{
+ IP: net.ParseIP("fe80::1"),
+ Zone: "en102",
+ },
+ },
},
},
},
@@ -217,6 +304,11 @@
if !reflect.DeepEqual(got, want) {
s += fmt.Sprintf("#%v/%v: got %#v; want %#v\n", i, j, got, want)
}
+ case *icmp.InterfaceInfo:
+ want := wantExts[j].(*icmp.InterfaceInfo)
+ if !reflect.DeepEqual(got, want) {
+ s += fmt.Sprintf("#%v/%v: got %#v, %#v, %#v; want %#v, %#v, %#v\n", i, j, got, got.Interface, got.Addr, want, want.Interface, want.Addr)
+ }
}
}
return s[:len(s)-1]
