diff options
Diffstat (limited to 'pkg/tcpip/header')
| -rw-r--r-- | pkg/tcpip/header/ipv6.go | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go index 066e48a9a..66c778fe1 100644 --- a/pkg/tcpip/header/ipv6.go +++ b/pkg/tcpip/header/ipv6.go @@ -202,3 +202,35 @@ func IsV6MulticastAddress(addr tcpip.Address) bool { } 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. +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:] +} + +// LinkLocalAddr computes the default IPv6 link-local address from a link-layer +// (MAC) address. +func LinkLocalAddr(linkAddr tcpip.LinkAddress) tcpip.Address { + // Convert a 48-bit MAC to an EUI-64 and then prepend the link-local + // header, FE80::. + // + // The conversion is very nearly: + // aa:bb:cc:dd:ee:ff => FE80::Aabb:ccFF:FEdd:eeff + // Note the capital A. The conversion aa->Aa involves a bit flip. + lladdrb := [16]byte{ + 0: 0xFE, + 1: 0x80, + 8: linkAddr[0] ^ 2, + 9: linkAddr[1], + 10: linkAddr[2], + 11: 0xFF, + 12: 0xFE, + 13: linkAddr[3], + 14: linkAddr[4], + 15: linkAddr[5], + } + return tcpip.Address(lladdrb[:]) +} |