diff options
| -rw-r--r-- | pkg/tcpip/header/icmpv6.go | 4 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv6/icmp.go | 12 | ||||
| -rw-r--r-- | pkg/tcpip/transport/icmp/endpoint.go | 6 |
3 files changed, 17 insertions, 5 deletions
diff --git a/pkg/tcpip/header/icmpv6.go b/pkg/tcpip/header/icmpv6.go index c2bfd8c79..b4037b6c8 100644 --- a/pkg/tcpip/header/icmpv6.go +++ b/pkg/tcpip/header/icmpv6.go @@ -132,7 +132,7 @@ func (b ICMPv6) Checksum() uint16 { return binary.BigEndian.Uint16(b[icmpv6ChecksumOffset:]) } -// SetChecksum calculates and sets the ICMP checksum field. +// SetChecksum sets the ICMP checksum field. func (b ICMPv6) SetChecksum(checksum uint16) { binary.BigEndian.PutUint16(b[icmpv6ChecksumOffset:], checksum) } @@ -197,7 +197,7 @@ func (b ICMPv6) Payload() []byte { return b[ICMPv6PayloadOffset:] } -// ICMPv6Checksum calculates the ICMP checksum over the provided ICMP header, +// ICMPv6Checksum calculates the ICMP checksum over the provided ICMPv6 header, // IPv6 src/dst addresses and the payload. func ICMPv6Checksum(h ICMPv6, src, dst tcpip.Address, vv buffer.VectorisedView) uint16 { // Calculate the IPv6 pseudo-header upper-layer checksum. diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index b289e902f..c3f1dd488 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -72,6 +72,18 @@ func (e *endpoint) handleICMP(r *stack.Route, netHeader buffer.View, vv buffer.V h := header.ICMPv6(v) iph := header.IPv6(netHeader) + // Validate ICMPv6 checksum before processing the packet. + // + // Only the first view in vv is accounted for by h. To account for the + // rest of vv, a shallow copy is made and the first view is removed. + // This copy is used as extra payload during the checksum calculation. + payload := vv + payload.RemoveFirst() + if got, want := h.Checksum(), header.ICMPv6Checksum(h, iph.SourceAddress(), iph.DestinationAddress(), payload); got != want { + received.Invalid.Increment() + return + } + // As per RFC 4861 sections 4.1 - 4.5, 6.1.1, 6.1.2, 7.1.1, 7.1.2 and // 8.1, nodes MUST silently drop NDP packets where the Hop Limit field // in the IPv6 header is not set to 255. diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go index 3187b336b..043467519 100644 --- a/pkg/tcpip/transport/icmp/endpoint.go +++ b/pkg/tcpip/transport/icmp/endpoint.go @@ -445,13 +445,13 @@ func send6(r *stack.Route, ident uint16, data buffer.View, ttl uint8) *tcpip.Err return tcpip.ErrInvalidEndpointState } - icmpv6.SetChecksum(0) - icmpv6.SetChecksum(^header.Checksum(icmpv6, header.Checksum(data, 0))) + dataVV := data.ToVectorisedView() + icmpv6.SetChecksum(header.ICMPv6Checksum(icmpv6, r.LocalAddress, r.RemoteAddress, dataVV)) if ttl == 0 { ttl = r.DefaultTTL() } - return r.WritePacket(nil /* gso */, hdr, data.ToVectorisedView(), stack.NetworkHeaderParams{Protocol: header.ICMPv6ProtocolNumber, TTL: ttl, TOS: stack.DefaultTOS}) + return r.WritePacket(nil /* gso */, hdr, dataVV, stack.NetworkHeaderParams{Protocol: header.ICMPv6ProtocolNumber, TTL: ttl, TOS: stack.DefaultTOS}) } func (e *endpoint) checkV4Mapped(addr *tcpip.FullAddress, allowMismatch bool) (tcpip.NetworkProtocolNumber, *tcpip.Error) { |