TUN-6666: Define packet package

This package defines IP and ICMP packet, decoders, encoder and flow

vendor/github.com/google/gopacket/layers/asf_presencepong.go

@@ -0,0 +1,194 @@
+// Copyright 2019 The GoPacket Authors. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license that can be found
+// in the LICENSE file in the root of the source tree.
+
+package layers
+
+// This file implements the RMCP ASF Presence Pong message, specified in section
+// 3.2.4.3 of
+// https://www.dmtf.org/sites/default/files/standards/documents/DSP0136.pdf. It
+// also contains non-competing elements from IPMI v2.0, specified in section
+// 13.2.4 of
+// https://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/ipmi-intelligent-platform-mgt-interface-spec-2nd-gen-v2-0-spec-update.pdf.
+
+import (
+	"encoding/binary"
+	"fmt"
+
+	"github.com/google/gopacket"
+)
+
+type (
+	// ASFEntity is the type of individual entities that a Presence Pong
+	// response can indicate support of. The entities currently implemented by
+	// the spec are IPMI and ASFv1.
+	ASFEntity uint8
+
+	// ASFInteraction is the type of individual interactions that a Presence
+	// Pong response can indicate support for. The interactions currently
+	// implemented by the spec are RMCP security extensions. Although not
+	// specified, IPMI uses this field to indicate support for DASH, which is
+	// supported as well.
+	ASFInteraction uint8
+)
+
+const (
+	// ASFDCMIEnterprise is the IANA-assigned Enterprise Number of the Data
+	// Center Manageability Interface Forum. The Presence Pong response's
+	// Enterprise field being set to this value indicates support for DCMI. The
+	// DCMI spec regards the OEM field as reserved, so these should be null.
+	ASFDCMIEnterprise uint32 = 36465
+
+	// ASFPresencePongEntityIPMI ANDs with Presence Pong's supported entities
+	// field if the managed system supports IPMI.
+	ASFPresencePongEntityIPMI ASFEntity = 1 << 7
+
+	// ASFPresencePongEntityASFv1 ANDs with Presence Pong's supported entities
+	// field if the managed system supports ASF v1.0.
+	ASFPresencePongEntityASFv1 ASFEntity = 1
+
+	// ASFPresencePongInteractionSecurityExtensions ANDs with Presence Pong's
+	// supported interactions field if the managed system supports RMCP v2.0
+	// security extensions. See section 3.2.3.
+	ASFPresencePongInteractionSecurityExtensions ASFInteraction = 1 << 7
+
+	// ASFPresencePongInteractionDASH ANDs with Presence Pong's supported
+	// interactions field if the managed system supports DMTF DASH. See
+	// https://www.dmtf.org/standards/dash.
+	ASFPresencePongInteractionDASH ASFInteraction = 1 << 5
+)
+
+// ASFPresencePong defines the structure of a Presence Pong message's payload.
+// See section 3.2.4.3.
+type ASFPresencePong struct {
+	BaseLayer
+
+	// Enterprise is the IANA Enterprise Number of an entity that has defined
+	// OEM-specific capabilities for the managed client. If no such capabilities
+	// exist, this is set to ASF's IANA Enterprise Number.
+	Enterprise uint32
+
+	// OEM identifies OEM-specific capabilities. Its structure is defined by the
+	// OEM. This is set to 0s if no OEM-specific capabilities exist. This
+	// implementation does not change byte order from the wire for this field.
+	OEM [4]byte
+
+	// We break out entities and interactions into separate booleans as
+	// discovery is the entire point of this type of message, so we assume they
+	// are accessed. It also makes gopacket's default layer printing more
+	// useful.
+
+	// IPMI is true if IPMI is supported by the managed system. There is no
+	// explicit version in the specification, however given the dates, this is
+	// assumed to be IPMI v1.0.  Support for IPMI is contained in the "supported
+	// entities" field of the presence pong payload.
+	IPMI bool
+
+	// ASFv1 indicates support for ASF v1.0. This seems somewhat redundant as
+	// ASF must be supported in order to receive a response. This is contained
+	// in the "supported entities" field of the presence pong payload.
+	ASFv1 bool
+
+	// SecurityExtensions indicates support for RMCP Security Extensions,
+	// specified in ASF v2.0. This will always be false for v1.x
+	// implementations. This is contained in the "supported interactions" field
+	// of the presence pong payload. This field is defined in ASF v1.0, but has
+	// no useful value.
+	SecurityExtensions bool
+
+	// DASH is true if DMTF DASH is supported. This is not specified in ASF
+	// v2.0, but in IPMI v2.0, however the former does not preclude it, so we
+	// support it.
+	DASH bool
+
+	// 6 bytes reserved after the entities and interactions fields, set to 0s.
+}
+
+// SupportsDCMI returns whether the Presence Pong message indicates support for
+// the Data Center Management Interface, which is an extension of IPMI v2.0.
+func (a *ASFPresencePong) SupportsDCMI() bool {
+	return a.Enterprise == ASFDCMIEnterprise && a.IPMI && a.ASFv1
+}
+
+// LayerType returns LayerTypeASFPresencePong. It partially satisfies Layer and
+// SerializableLayer.
+func (*ASFPresencePong) LayerType() gopacket.LayerType {
+	return LayerTypeASFPresencePong
+}
+
+// CanDecode returns LayerTypeASFPresencePong. It partially satisfies
+// DecodingLayer.
+func (a *ASFPresencePong) CanDecode() gopacket.LayerClass {
+	return a.LayerType()
+}
+
+// DecodeFromBytes makes the layer represent the provided bytes. It partially
+// satisfies DecodingLayer.
+func (a *ASFPresencePong) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
+	if len(data) < 16 {
+		df.SetTruncated()
+		return fmt.Errorf("invalid ASF presence pong payload, length %v less than 16",
+			len(data))
+	}
+
+	a.BaseLayer.Contents = data[:16]
+	a.BaseLayer.Payload = data[16:]
+
+	a.Enterprise = binary.BigEndian.Uint32(data[:4])
+	copy(a.OEM[:], data[4:8]) // N.B. no byte order change
+	a.IPMI = data[8]&uint8(ASFPresencePongEntityIPMI) != 0
+	a.ASFv1 = data[8]&uint8(ASFPresencePongEntityASFv1) != 0
+	a.SecurityExtensions = data[9]&uint8(ASFPresencePongInteractionSecurityExtensions) != 0
+	a.DASH = data[9]&uint8(ASFPresencePongInteractionDASH) != 0
+	// ignore remaining 6 bytes; should be set to 0s
+	return nil
+}
+
+// NextLayerType returns LayerTypePayload, as there are no further layers to
+// decode. This partially satisfies DecodingLayer.
+func (a *ASFPresencePong) NextLayerType() gopacket.LayerType {
+	return gopacket.LayerTypePayload
+}
+
+// SerializeTo writes the serialized fom of this layer into the SerializeBuffer,
+// partially satisfying SerializableLayer.
+func (a *ASFPresencePong) SerializeTo(b gopacket.SerializeBuffer, _ gopacket.SerializeOptions) error {
+	bytes, err := b.PrependBytes(16)
+	if err != nil {
+		return err
+	}
+
+	binary.BigEndian.PutUint32(bytes[:4], a.Enterprise)
+
+	copy(bytes[4:8], a.OEM[:])
+
+	bytes[8] = 0
+	if a.IPMI {
+		bytes[8] |= uint8(ASFPresencePongEntityIPMI)
+	}
+	if a.ASFv1 {
+		bytes[8] |= uint8(ASFPresencePongEntityASFv1)
+	}
+
+	bytes[9] = 0
+	if a.SecurityExtensions {
+		bytes[9] |= uint8(ASFPresencePongInteractionSecurityExtensions)
+	}
+	if a.DASH {
+		bytes[9] |= uint8(ASFPresencePongInteractionDASH)
+	}
+
+	// zero-out remaining 6 bytes
+	for i := 10; i < len(bytes); i++ {
+		bytes[i] = 0x00
+	}
+
+	return nil
+}
+
+// decodeASFPresencePong decodes the byte slice into an RMCP-ASF Presence Pong
+// struct.
+func decodeASFPresencePong(data []byte, p gopacket.PacketBuilder) error {
+	return decodingLayerDecoder(&ASFPresencePong{}, data, p)
+}