diff options
| -rw-r--r-- | pkg/tcpip/header/ipv6.go | 9 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv6/icmp.go | 11 |
2 files changed, 19 insertions, 1 deletions
diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go index ef454b313..c5d8a3456 100644 --- a/pkg/tcpip/header/ipv6.go +++ b/pkg/tcpip/header/ipv6.go @@ -309,14 +309,21 @@ func IsV6UnicastAddress(addr tcpip.Address) bool { return addr[0] != 0xff } +const solicitedNodeMulticastPrefix = "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\xff" + // 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. func SolicitedNodeAddr(addr tcpip.Address) tcpip.Address { - const solicitedNodeMulticastPrefix = "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\xff" return solicitedNodeMulticastPrefix + addr[len(addr)-3:] } +// IsSolicitedNodeAddr determines whether the address is a solicited-node +// multicast address. +func IsSolicitedNodeAddr(addr tcpip.Address) bool { + return solicitedNodeMulticastPrefix == addr[:len(addr)-3] +} + // EthernetAdddressToModifiedEUI64IntoBuf populates buf with a modified EUI-64 // from a 48-bit Ethernet/MAC address, as per RFC 4291 section 2.5.1. // diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index 8e9def6b8..629d1818e 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -286,6 +286,17 @@ func (e *endpoint) handleICMP(r *stack.Route, pkt *stack.PacketBuffer, hasFragme e.linkAddrCache.AddLinkAddress(e.nic.ID(), r.RemoteAddress, sourceLinkAddr) } + // As per RFC 4861 section 7.1.1: + // A node MUST silently discard any received Neighbor Solicitation + // messages that do not satisfy all of the following validity checks: + // ... + // - If the IP source address is the unspecified address, the IP + // destination address is a solicited-node multicast address. + if unspecifiedSource && !header.IsSolicitedNodeAddr(r.LocalAddress) { + received.Invalid.Increment() + return + } + // ICMPv6 Neighbor Solicit messages are always sent to // specially crafted IPv6 multicast addresses. As a result, the // route we end up with here has as its LocalAddress such a |