diff options
Diffstat (limited to 'pkg/tcpip/network/ipv6')
| -rw-r--r-- | pkg/tcpip/network/ipv6/icmp.go | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index 346de9ae3..b4d0295bf 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -21,6 +21,15 @@ import ( "gvisor.dev/gvisor/pkg/tcpip/stack" ) +const ( + // ndpHopLimit is the expected IP hop limit value of 255 for received + // NDP packets, as per RFC 4861 sections 4.1 - 4.5, 6.1.1, 6.1.2, 7.1.1, + // 7.1.2 and 8.1. If the hop limit value is not 255, nodes MUST silently + // drop the NDP packet. All outgoing NDP packets must use this value for + // its IP hop limit field. + ndpHopLimit = 255 +) + // handleControl handles the case when an ICMP packet contains the headers of // the original packet that caused the ICMP one to be sent. This information is // used to find out which transport endpoint must be notified about the ICMP @@ -71,6 +80,21 @@ func (e *endpoint) handleICMP(r *stack.Route, netHeader buffer.View, vv buffer.V } h := header.ICMPv6(v) + // 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. + switch h.Type() { + case header.ICMPv6NeighborSolicit, + header.ICMPv6NeighborAdvert, + header.ICMPv6RouterSolicit, + header.ICMPv6RouterAdvert, + header.ICMPv6RedirectMsg: + if header.IPv6(netHeader).HopLimit() != ndpHopLimit { + received.Invalid.Increment() + return + } + } + // TODO(b/112892170): Meaningfully handle all ICMP types. switch h.Type() { case header.ICMPv6PacketTooBig: |