diff options
Diffstat (limited to 'pkg/tcpip/header/ipv6.go')
| -rw-r--r-- | pkg/tcpip/header/ipv6.go | 55 |
1 files changed, 41 insertions, 14 deletions
diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go index 31be42ce0..9d3abc0e4 100644 --- a/pkg/tcpip/header/ipv6.go +++ b/pkg/tcpip/header/ipv6.go @@ -22,12 +22,14 @@ import ( ) const ( - versTCFL = 0 - payloadLen = 4 - nextHdr = 6 - hopLimit = 7 - v6SrcAddr = 8 - v6DstAddr = 24 + versTCFL = 0 + // IPv6PayloadLenOffset is the offset of the PayloadLength field in + // IPv6 header. + IPv6PayloadLenOffset = 4 + nextHdr = 6 + hopLimit = 7 + v6SrcAddr = 8 + v6DstAddr = v6SrcAddr + IPv6AddressSize ) // IPv6Fields contains the fields of an IPv6 packet. It is used to describe the @@ -74,6 +76,13 @@ const ( // IPv6Version is the version of the ipv6 protocol. IPv6Version = 6 + // IPv6AllNodesMulticastAddress is a link-local multicast group that + // all IPv6 nodes MUST join, as per RFC 4291, section 2.8. Packets + // destined to this address will reach all nodes on a link. + // + // The address is ff02::1. + IPv6AllNodesMulticastAddress tcpip.Address = "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01" + // IPv6MinimumMTU is the minimum MTU required by IPv6, per RFC 2460, // section 5. IPv6MinimumMTU = 1280 @@ -94,7 +103,7 @@ var IPv6EmptySubnet = func() tcpip.Subnet { // PayloadLength returns the value of the "payload length" field of the ipv6 // header. func (b IPv6) PayloadLength() uint16 { - return binary.BigEndian.Uint16(b[payloadLen:]) + return binary.BigEndian.Uint16(b[IPv6PayloadLenOffset:]) } // HopLimit returns the value of the "hop limit" field of the ipv6 header. @@ -119,13 +128,13 @@ func (b IPv6) Payload() []byte { // SourceAddress returns the "source address" field of the ipv6 header. func (b IPv6) SourceAddress() tcpip.Address { - return tcpip.Address(b[v6SrcAddr : v6SrcAddr+IPv6AddressSize]) + return tcpip.Address(b[v6SrcAddr:][:IPv6AddressSize]) } // DestinationAddress returns the "destination address" field of the ipv6 // header. func (b IPv6) DestinationAddress() tcpip.Address { - return tcpip.Address(b[v6DstAddr : v6DstAddr+IPv6AddressSize]) + return tcpip.Address(b[v6DstAddr:][:IPv6AddressSize]) } // Checksum implements Network.Checksum. Given that IPv6 doesn't have a @@ -148,18 +157,18 @@ func (b IPv6) SetTOS(t uint8, l uint32) { // SetPayloadLength sets the "payload length" field of the ipv6 header. func (b IPv6) SetPayloadLength(payloadLength uint16) { - binary.BigEndian.PutUint16(b[payloadLen:], payloadLength) + binary.BigEndian.PutUint16(b[IPv6PayloadLenOffset:], payloadLength) } // SetSourceAddress sets the "source address" field of the ipv6 header. func (b IPv6) SetSourceAddress(addr tcpip.Address) { - copy(b[v6SrcAddr:v6SrcAddr+IPv6AddressSize], addr) + copy(b[v6SrcAddr:][:IPv6AddressSize], addr) } // SetDestinationAddress sets the "destination address" field of the ipv6 // header. func (b IPv6) SetDestinationAddress(addr tcpip.Address) { - copy(b[v6DstAddr:v6DstAddr+IPv6AddressSize], addr) + copy(b[v6DstAddr:][:IPv6AddressSize], addr) } // SetNextHeader sets the value of the "next header" field of the ipv6 header. @@ -178,8 +187,8 @@ func (b IPv6) Encode(i *IPv6Fields) { b.SetPayloadLength(i.PayloadLength) b[nextHdr] = i.NextHeader b[hopLimit] = i.HopLimit - copy(b[v6SrcAddr:v6SrcAddr+IPv6AddressSize], i.SrcAddr) - copy(b[v6DstAddr:v6DstAddr+IPv6AddressSize], i.DstAddr) + b.SetSourceAddress(i.SrcAddr) + b.SetDestinationAddress(i.DstAddr) } // IsValid performs basic validation on the packet. @@ -219,6 +228,24 @@ func IsV6MulticastAddress(addr tcpip.Address) bool { return addr[0] == 0xff } +// IsV6UnicastAddress determines if the provided address is a valid IPv6 +// unicast (and specified) address. That is, IsV6UnicastAddress returns +// true if addr contains IPv6AddressSize bytes, is not the unspecified +// address and is not a multicast address. +func IsV6UnicastAddress(addr tcpip.Address) bool { + if len(addr) != IPv6AddressSize { + return false + } + + // Must not be unspecified + if addr == IPv6Any { + return false + } + + // Return if not a multicast. + return addr[0] != 0xff +} + // SolicitedNodeAddr computes the solicited-node multicast address. This is // used for NDP. Described in RFC 4291. The argument must be a full-length IPv6 // address. |