diff options
Diffstat (limited to 'vendor/github.com/vishvananda/netlink/nl/seg6_linux.go')
-rw-r--r-- | vendor/github.com/vishvananda/netlink/nl/seg6_linux.go | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/vendor/github.com/vishvananda/netlink/nl/seg6_linux.go b/vendor/github.com/vishvananda/netlink/nl/seg6_linux.go new file mode 100644 index 000000000..b3425f6b0 --- /dev/null +++ b/vendor/github.com/vishvananda/netlink/nl/seg6_linux.go @@ -0,0 +1,111 @@ +package nl + +import ( + "errors" + "fmt" + "net" +) + +type IPv6SrHdr struct { + nextHdr uint8 + hdrLen uint8 + routingType uint8 + segmentsLeft uint8 + firstSegment uint8 + flags uint8 + reserved uint16 + + Segments []net.IP +} + +func (s1 *IPv6SrHdr) Equal(s2 IPv6SrHdr) bool { + if len(s1.Segments) != len(s2.Segments) { + return false + } + for i := range s1.Segments { + if s1.Segments[i].Equal(s2.Segments[i]) != true { + return false + } + } + return s1.nextHdr == s2.nextHdr && + s1.hdrLen == s2.hdrLen && + s1.routingType == s2.routingType && + s1.segmentsLeft == s2.segmentsLeft && + s1.firstSegment == s2.firstSegment && + s1.flags == s2.flags + // reserved doesn't need to be identical. +} + +// seg6 encap mode +const ( + SEG6_IPTUN_MODE_INLINE = iota + SEG6_IPTUN_MODE_ENCAP +) + +// number of nested RTATTR +// from include/uapi/linux/seg6_iptunnel.h +const ( + SEG6_IPTUNNEL_UNSPEC = iota + SEG6_IPTUNNEL_SRH + __SEG6_IPTUNNEL_MAX +) +const ( + SEG6_IPTUNNEL_MAX = __SEG6_IPTUNNEL_MAX - 1 +) + +func EncodeSEG6Encap(mode int, segments []net.IP) ([]byte, error) { + nsegs := len(segments) // nsegs: number of segments + if nsegs == 0 { + return nil, errors.New("EncodeSEG6Encap: No Segment in srh") + } + b := make([]byte, 12, 12+len(segments)*16) + native := NativeEndian() + native.PutUint32(b, uint32(mode)) + b[4] = 0 // srh.nextHdr (0 when calling netlink) + b[5] = uint8(16 * nsegs >> 3) // srh.hdrLen (in 8-octets unit) + b[6] = IPV6_SRCRT_TYPE_4 // srh.routingType (assigned by IANA) + b[7] = uint8(nsegs - 1) // srh.segmentsLeft + b[8] = uint8(nsegs - 1) // srh.firstSegment + b[9] = 0 // srh.flags (SR6_FLAG1_HMAC for srh_hmac) + // srh.reserved: Defined as "Tag" in draft-ietf-6man-segment-routing-header-07 + native.PutUint16(b[10:], 0) // srh.reserved + for _, netIP := range segments { + b = append(b, netIP...) // srh.Segments + } + return b, nil +} + +func DecodeSEG6Encap(buf []byte) (int, []net.IP, error) { + native := NativeEndian() + mode := int(native.Uint32(buf)) + srh := IPv6SrHdr{ + nextHdr: buf[4], + hdrLen: buf[5], + routingType: buf[6], + segmentsLeft: buf[7], + firstSegment: buf[8], + flags: buf[9], + reserved: native.Uint16(buf[10:12]), + } + buf = buf[12:] + if len(buf)%16 != 0 { + err := fmt.Errorf("DecodeSEG6Encap: error parsing Segment List (buf len: %d)\n", len(buf)) + return mode, nil, err + } + for len(buf) > 0 { + srh.Segments = append(srh.Segments, net.IP(buf[:16])) + buf = buf[16:] + } + return mode, srh.Segments, nil +} + +// Helper functions +func SEG6EncapModeString(mode int) string { + switch mode { + case SEG6_IPTUN_MODE_INLINE: + return "inline" + case SEG6_IPTUN_MODE_ENCAP: + return "encap" + } + return "unknown" +} |