diff options
| author | Ghanan Gowripalan <ghanan@google.com> | 2021-04-06 10:14:10 -0700 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2021-04-06 10:15:46 -0700 |
| commit | d7fd00bad1416fb44b3303331ee223c28c69fe9b (patch) | |
| tree | 14c46e6f0b89aaf6c9986175fbc4d0fb1346a8a5 /pkg/tcpip/header/ipv6.go | |
| parent | fb4c700d0610ca83048aaf3a71682de0d9619156 (diff) | |
Do not perform MLD for certain multicast scopes
...as per RFC 2710 section 5 page 10.
Test: ipv6_test.TestMLDSkipProtocol
PiperOrigin-RevId: 367031126
Diffstat (limited to 'pkg/tcpip/header/ipv6.go')
| -rw-r--r-- | pkg/tcpip/header/ipv6.go | 49 |
1 files changed, 43 insertions, 6 deletions
diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go index f2403978c..7711abec1 100644 --- a/pkg/tcpip/header/ipv6.go +++ b/pkg/tcpip/header/ipv6.go @@ -142,11 +142,6 @@ const ( // ipv6MulticastAddressScopeMask is the mask for the scope (scop) field, // within the byte holding the field, as per RFC 4291 section 2.7. ipv6MulticastAddressScopeMask = 0xF - - // ipv6LinkLocalMulticastScope is the value of the scope (scop) field within - // a multicast IPv6 address that indicates the address has link-local scope, - // as per RFC 4291 section 2.7. - ipv6LinkLocalMulticastScope = 2 ) // IPv6EmptySubnet is the empty IPv6 subnet. It may also be known as the @@ -399,7 +394,7 @@ func IsV6LoopbackAddress(addr tcpip.Address) bool { // IsV6LinkLocalMulticastAddress determines if the provided address is an IPv6 // link-local multicast address. func IsV6LinkLocalMulticastAddress(addr tcpip.Address) bool { - return IsV6MulticastAddress(addr) && addr[ipv6MulticastAddressScopeByteIdx]&ipv6MulticastAddressScopeMask == ipv6LinkLocalMulticastScope + return IsV6MulticastAddress(addr) && V6MulticastScope(addr) == IPv6LinkLocalMulticastScope } // AppendOpaqueInterfaceIdentifier appends a 64 bit opaque interface identifier @@ -520,3 +515,45 @@ func GenerateTempIPv6SLAACAddr(tempIIDHistory []byte, stableAddr tcpip.Address) PrefixLen: IIDOffsetInIPv6Address * 8, } } + +// IPv6MulticastScope is the scope of a multicast IPv6 address. +type IPv6MulticastScope uint8 + +// The various values for IPv6 multicast scopes, as per RFC 7346 section 2: +// +// +------+--------------------------+-------------------------+ +// | scop | NAME | REFERENCE | +// +------+--------------------------+-------------------------+ +// | 0 | Reserved | [RFC4291], RFC 7346 | +// | 1 | Interface-Local scope | [RFC4291], RFC 7346 | +// | 2 | Link-Local scope | [RFC4291], RFC 7346 | +// | 3 | Realm-Local scope | [RFC4291], RFC 7346 | +// | 4 | Admin-Local scope | [RFC4291], RFC 7346 | +// | 5 | Site-Local scope | [RFC4291], RFC 7346 | +// | 6 | Unassigned | | +// | 7 | Unassigned | | +// | 8 | Organization-Local scope | [RFC4291], RFC 7346 | +// | 9 | Unassigned | | +// | A | Unassigned | | +// | B | Unassigned | | +// | C | Unassigned | | +// | D | Unassigned | | +// | E | Global scope | [RFC4291], RFC 7346 | +// | F | Reserved | [RFC4291], RFC 7346 | +// +------+--------------------------+-------------------------+ +const ( + IPv6Reserved0MulticastScope = IPv6MulticastScope(0x0) + IPv6InterfaceLocalMulticastScope = IPv6MulticastScope(0x1) + IPv6LinkLocalMulticastScope = IPv6MulticastScope(0x2) + IPv6RealmLocalMulticastScope = IPv6MulticastScope(0x3) + IPv6AdminLocalMulticastScope = IPv6MulticastScope(0x4) + IPv6SiteLocalMulticastScope = IPv6MulticastScope(0x5) + IPv6OrganizationLocalMulticastScope = IPv6MulticastScope(0x8) + IPv6GlobalMulticastScope = IPv6MulticastScope(0xE) + IPv6ReservedFMulticastScope = IPv6MulticastScope(0xF) +) + +// V6MulticastScope returns the scope of a multicast address. +func V6MulticastScope(addr tcpip.Address) IPv6MulticastScope { + return IPv6MulticastScope(addr[ipv6MulticastAddressScopeByteIdx] & ipv6MulticastAddressScopeMask) +} |