diff options
Diffstat (limited to 'packet/mrt.go')
-rw-r--r-- | packet/mrt.go | 732 |
1 files changed, 732 insertions, 0 deletions
diff --git a/packet/mrt.go b/packet/mrt.go new file mode 100644 index 00000000..f31013ec --- /dev/null +++ b/packet/mrt.go @@ -0,0 +1,732 @@ +// Copyright (C) 2015 Nippon Telegraph and Telephone Corporation. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or +// implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package bgp + +import ( + "bytes" + "encoding/binary" + "fmt" + "math" + "net" +) + +const ( + MRT_COMMON_HEADER_LEN = 12 +) + +type MRTType uint16 + +const ( + NULL MRTType = 0 // deprecated + START MRTType = 1 // deprecated + DIE MRTType = 2 // deprecated + I_AM_DEAD MRTType = 3 // deprecated + PEER_DOWN MRTType = 4 // deprecated + BGP MRTType = 5 // deprecated + RIP MRTType = 6 // deprecated + IDRP MRTType = 7 // deprecated + RIPNG MRTType = 8 // deprecated + BGP4PLUS MRTType = 9 // deprecated + BGP4PLUS01 MRTType = 10 // deprecated + OSPFv2 MRTType = 11 + TABLE_DUMP MRTType = 12 + TABLE_DUMPv2 MRTType = 13 + BGP4MP MRTType = 16 + BGP4MP_ET MRTType = 17 + ISIS MRTType = 32 + ISIS_ET MRTType = 33 + OSPFv3 MRTType = 48 + OSPFv3_ET MRTType = 49 +) + +type MRTSubTyper interface { + ToUint16() uint16 +} + +type MRTSubTypeTableDumpv2 uint16 + +const ( + PEER_INDEX_TABLE MRTSubTypeTableDumpv2 = 1 + RIB_IPV4_UNICAST MRTSubTypeTableDumpv2 = 2 + RIB_IPV4_MULTICAST MRTSubTypeTableDumpv2 = 3 + RIB_IPV6_UNICAST MRTSubTypeTableDumpv2 = 4 + RIB_IPV6_MULTICAST MRTSubTypeTableDumpv2 = 5 + RIB_GENERIC MRTSubTypeTableDumpv2 = 6 +) + +func (t MRTSubTypeTableDumpv2) ToUint16() uint16 { + return uint16(t) +} + +type MRTSubTypeBGP4MP uint16 + +const ( + STATE_CHANGE MRTSubTypeBGP4MP = 0 + MESSAGE MRTSubTypeBGP4MP = 1 + MESSAGE_AS4 MRTSubTypeBGP4MP = 4 + STATE_CHANGE_AS4 MRTSubTypeBGP4MP = 5 + MESSAGE_LOCAL MRTSubTypeBGP4MP = 6 + MESSAGE_AS4_LOCAL MRTSubTypeBGP4MP = 7 +) + +func (t MRTSubTypeBGP4MP) ToUint16() uint16 { + return uint16(t) +} + +type BGPState uint16 + +const ( + IDLE BGPState = 1 + CONNECT BGPState = 2 + ACTIVE BGPState = 3 + OPENSENT BGPState = 4 + OPENCONFIRM BGPState = 5 + ESTABLISHED BGPState = 6 +) + +func packValues(values []interface{}) ([]byte, error) { + b := new(bytes.Buffer) + for _, v := range values { + err := binary.Write(b, binary.BigEndian, v) + if err != nil { + return nil, err + } + } + return b.Bytes(), nil +} + +type MRTHeader struct { + Timestamp uint32 + Type MRTType + SubType uint16 + Len uint32 +} + +func (h *MRTHeader) DecodeFromBytes(data []byte) error { + if len(data) < MRT_COMMON_HEADER_LEN { + return fmt.Errorf("not all MRTHeader bytes are available. expected: %d, actual: %d", MRT_COMMON_HEADER_LEN, len(data)) + } + h.Timestamp = binary.BigEndian.Uint32(data[:4]) + h.Type = MRTType(binary.BigEndian.Uint16(data[4:6])) + h.SubType = binary.BigEndian.Uint16(data[6:8]) + h.Len = binary.BigEndian.Uint32(data[8:12]) + return nil +} + +func (h *MRTHeader) Serialize() ([]byte, error) { + return packValues([]interface{}{h.Timestamp, h.Type, h.SubType, h.Len}) +} + +func NewMRTHeader(timestamp uint32, t MRTType, subtype MRTSubTyper, l uint32) (*MRTHeader, error) { + return &MRTHeader{ + Timestamp: timestamp, + Type: t, + SubType: subtype.ToUint16(), + Len: l, + }, nil +} + +type MRTMessage struct { + Header MRTHeader + Body Body +} + +type Body interface { + DecodeFromBytes([]byte) error + Serialize() ([]byte, error) +} + +type Peer struct { + Type uint8 + BgpId net.IP + IpAddress net.IP + AS uint32 +} + +func (p *Peer) DecodeFromBytes(data []byte) ([]byte, error) { + notAllBytesAvail := fmt.Errorf("not all Peer bytes are available") + if len(data) < 5 { + return nil, notAllBytesAvail + } + p.Type = uint8(data[0]) + p.BgpId = net.IP(data[1:5]) + data = data[5:] + + if p.Type&1 > 0 { + if len(data) < 16 { + return nil, notAllBytesAvail + } + p.IpAddress = net.IP(data[:16]) + data = data[16:] + } else { + if len(data) < 4 { + return nil, notAllBytesAvail + } + p.IpAddress = net.IP(data[:4]) + data = data[4:] + } + + if p.Type&(1<<1) > 0 { + if len(data) < 4 { + return nil, notAllBytesAvail + } + p.AS = binary.BigEndian.Uint32(data[:4]) + data = data[4:] + } else { + if len(data) < 2 { + return nil, notAllBytesAvail + } + p.AS = uint32(binary.BigEndian.Uint16(data[:2])) + data = data[2:] + } + + return data, nil +} + +func (p *Peer) Serialize() ([]byte, error) { + var err error + var bbuf []byte + buf := make([]byte, 5) + buf[0] = uint8(p.Type) + if p.BgpId.To4() == nil { + return nil, fmt.Errorf("invalid BGP ID") + } + copy(buf[1:], p.BgpId.To4()) + if p.Type&1 > 0 { + buf = append(buf, p.IpAddress.To16()...) + } else { + buf = append(buf, p.IpAddress.To4()...) + } + if p.Type&(1<<1) > 0 { + bbuf, err = packValues([]interface{}{p.AS}) + } else { + if p.AS > uint32(math.MaxUint16) { + return nil, fmt.Errorf("AS number is beyond 2 octet. %d > %d", p.AS, math.MaxUint16) + } + bbuf, err = packValues([]interface{}{uint16(p.AS)}) + } + if err != nil { + return nil, err + } + return append(buf, bbuf...), nil +} + +func NewPeer(bgpid string, ipaddr string, asn uint32, isAS4 bool) *Peer { + t := 0 + addr := net.ParseIP(ipaddr).To4() + if addr == nil { + t |= 1 + addr = net.ParseIP(ipaddr).To16() + } + if isAS4 { + t |= (1 << 1) + } + return &Peer{ + Type: uint8(t), + BgpId: net.ParseIP(bgpid).To4(), + IpAddress: addr, + AS: asn, + } +} + +func (p *Peer) String() string { + return fmt.Sprintf("PEER ENTRY: ID [%s] Addr [%s] AS [%d]", p.BgpId, p.IpAddress, p.AS) +} + +type PeerIndexTable struct { + CollectorBgpId net.IP + ViewName string + Peers []*Peer +} + +func (t *PeerIndexTable) DecodeFromBytes(data []byte) error { + notAllBytesAvail := fmt.Errorf("not all PeerIndexTable bytes are available") + if len(data) < 6 { + return notAllBytesAvail + } + t.CollectorBgpId = net.IP(data[:4]) + viewLen := binary.BigEndian.Uint16(data[4:6]) + if len(data) < 6+int(viewLen) { + return notAllBytesAvail + } + t.ViewName = string(data[6 : 6+viewLen]) + + data = data[6+viewLen:] + + if len(data) < 2 { + return notAllBytesAvail + } + peerNum := binary.BigEndian.Uint16(data[:2]) + data = data[2:] + t.Peers = make([]*Peer, 0, peerNum) + var err error + for i := 0; i < int(peerNum); i++ { + p := &Peer{} + data, err = p.DecodeFromBytes(data) + if err != nil { + return err + } + t.Peers = append(t.Peers, p) + } + + return nil +} + +func (t *PeerIndexTable) Serialize() ([]byte, error) { + buf := make([]byte, 8+len(t.ViewName)) + copy(buf, t.CollectorBgpId.To4()) + binary.BigEndian.PutUint16(buf[4:], uint16(len(t.ViewName))) + copy(buf[6:], t.ViewName) + binary.BigEndian.PutUint16(buf[6+len(t.ViewName):], uint16(len(t.Peers))) + for _, peer := range t.Peers { + bbuf, err := peer.Serialize() + if err != nil { + return nil, err + } + buf = append(buf, bbuf...) + } + return buf, nil +} + +func NewPeerIndexTable(bgpid string, viewname string, peers []*Peer) *PeerIndexTable { + return &PeerIndexTable{ + CollectorBgpId: net.ParseIP(bgpid).To4(), + ViewName: viewname, + Peers: peers, + } +} + +func (t *PeerIndexTable) String() string { + return fmt.Sprintf("PEER_INDEX_TABLE: CollectorBgpId [%s] ViewName [%s] Peers [%s]", t.CollectorBgpId, t.ViewName, t.Peers) +} + +type RibEntry struct { + PeerIndex uint16 + OriginatedTime uint32 + PathAttributes []PathAttributeInterface +} + +func (e *RibEntry) DecodeFromBytes(data []byte) ([]byte, error) { + notAllBytesAvail := fmt.Errorf("not all RibEntry bytes are available") + if len(data) < 8 { + return nil, notAllBytesAvail + } + e.PeerIndex = binary.BigEndian.Uint16(data[:2]) + e.OriginatedTime = binary.BigEndian.Uint32(data[2:6]) + totalLen := binary.BigEndian.Uint16(data[6:8]) + data = data[8:] + for attrLen := totalLen; attrLen > 0; { + p, err := GetPathAttribute(data) + if err != nil { + return nil, err + } + err = p.DecodeFromBytes(data) + if err != nil { + return nil, err + } + attrLen -= uint16(p.Len()) + if len(data) < p.Len() { + return nil, notAllBytesAvail + } + data = data[p.Len():] + e.PathAttributes = append(e.PathAttributes, p) + } + return data, nil +} + +func (e *RibEntry) Serialize() ([]byte, error) { + buf := make([]byte, 8) + binary.BigEndian.PutUint16(buf, e.PeerIndex) + binary.BigEndian.PutUint32(buf[2:], e.OriginatedTime) + totalLen := 0 + binary.BigEndian.PutUint16(buf[6:], uint16(totalLen)) + for _, pattr := range e.PathAttributes { + bbuf, err := pattr.Serialize() + if err != nil { + return nil, err + } + buf = append(buf, bbuf...) + totalLen += len(bbuf) + } + binary.BigEndian.PutUint16(buf[6:], uint16(totalLen)) + return buf, nil +} + +func NewRibEntry(index uint16, time uint32, pathattrs []PathAttributeInterface) *RibEntry { + return &RibEntry{ + PeerIndex: index, + OriginatedTime: time, + PathAttributes: pathattrs, + } +} + +type Rib struct { + SequenceNumber uint32 + Prefix AddrPrefixInterface + Entries []*RibEntry + RouteFamily RouteFamily +} + +func (u *Rib) DecodeFromBytes(data []byte) error { + if len(data) < 4 { + return fmt.Errorf("Not all RibIpv4Unicast message bytes available") + } + u.SequenceNumber = binary.BigEndian.Uint32(data[:4]) + data = data[4:] + afi, safi := RouteFamilyToAfiSafi(u.RouteFamily) + if afi == 0 && safi == 0 { + afi = binary.BigEndian.Uint16(data[:2]) + safi = data[2] + data = data[3:] + } + prefix, err := NewPrefixFromRouteFamily(afi, safi) + if err != nil { + return err + } + err = prefix.DecodeFromBytes(data) + if err != nil { + return err + } + u.Prefix = prefix + data = data[prefix.Len():] + entryNum := binary.BigEndian.Uint16(data[:2]) + data = data[2:] + u.Entries = make([]*RibEntry, 0, entryNum) + for i := 0; i < int(entryNum); i++ { + e := &RibEntry{} + data, err = e.DecodeFromBytes(data) + if err != nil { + return err + } + u.Entries = append(u.Entries, e) + } + return nil +} + +func (u *Rib) Serialize() ([]byte, error) { + buf := make([]byte, 4) + binary.BigEndian.PutUint32(buf, u.SequenceNumber) + rf := AfiSafiToRouteFamily(u.Prefix.AFI(), u.Prefix.SAFI()) + switch rf { + case RF_IPv4_UC, RF_IPv4_MC, RF_IPv6_UC, RF_IPv6_MC: + default: + bbuf := make([]byte, 0, 2) + binary.BigEndian.PutUint16(bbuf, u.Prefix.AFI()) + buf = append(buf, bbuf...) + buf = append(buf, u.Prefix.SAFI()) + } + bbuf, err := u.Prefix.Serialize() + if err != nil { + return nil, err + } + buf = append(buf, bbuf...) + bbuf, err = packValues([]interface{}{uint16(len(u.Entries))}) + if err != nil { + return nil, err + } + buf = append(buf, bbuf...) + for _, entry := range u.Entries { + bbuf, err = entry.Serialize() + if err != nil { + return nil, err + } + buf = append(buf, bbuf...) + } + return buf, nil +} + +func NewRib(seq uint32, prefix AddrPrefixInterface, entries []*RibEntry) *Rib { + rf := AfiSafiToRouteFamily(prefix.AFI(), prefix.SAFI()) + return &Rib{ + SequenceNumber: seq, + Prefix: prefix, + Entries: entries, + RouteFamily: rf, + } +} + +func (u *Rib) String() string { + return fmt.Sprintf("RIB: Seq [%d] Prefix [%s] Entries [%s]", u.SequenceNumber, u.Prefix, u.Entries) +} + +type BGP4MPHeader struct { + PeerAS uint32 + LocalAS uint32 + InterfaceIndex uint16 + AddressFamily uint16 + PeerIpAddress net.IP + LocalIpAddress net.IP + isAS4 bool +} + +func (m *BGP4MPHeader) decodeFromBytes(data []byte) ([]byte, error) { + if m.isAS4 && len(data) < 8 { + return nil, fmt.Errorf("Not all BGP4MPMessageAS4 bytes available") + } else if !m.isAS4 && len(data) < 4 { + return nil, fmt.Errorf("Not all BGP4MPMessageAS bytes available") + } + + if m.isAS4 { + m.PeerAS = binary.BigEndian.Uint32(data[:4]) + m.LocalAS = binary.BigEndian.Uint32(data[4:8]) + data = data[8:] + } else { + m.PeerAS = uint32(binary.BigEndian.Uint16(data[:2])) + m.LocalAS = uint32(binary.BigEndian.Uint16(data[2:4])) + data = data[4:] + } + m.InterfaceIndex = binary.BigEndian.Uint16(data[:2]) + m.AddressFamily = binary.BigEndian.Uint16(data[2:4]) + switch m.AddressFamily { + case AFI_IP: + m.PeerIpAddress = net.IP(data[4:8]).To4() + m.LocalIpAddress = net.IP(data[8:12]).To4() + data = data[12:] + case AFI_IP6: + m.PeerIpAddress = net.IP(data[4:20]) + m.LocalIpAddress = net.IP(data[20:36]) + data = data[36:] + default: + return nil, fmt.Errorf("unsupported address family: %d", m.AddressFamily) + } + return data, nil +} + +func (m *BGP4MPHeader) serialize() ([]byte, error) { + var values []interface{} + if m.isAS4 { + values = []interface{}{m.PeerAS, m.LocalAS, m.InterfaceIndex, m.AddressFamily} + } else { + values = []interface{}{uint16(m.PeerAS), uint16(m.LocalAS), m.InterfaceIndex, m.AddressFamily} + } + buf, err := packValues(values) + if err != nil { + return nil, err + } + var bbuf []byte + switch m.AddressFamily { + case AFI_IP: + bbuf = make([]byte, 8) + copy(bbuf, m.PeerIpAddress.To4()) + copy(bbuf[4:], m.LocalIpAddress.To4()) + case AFI_IP6: + bbuf = make([]byte, 32) + copy(bbuf, m.PeerIpAddress) + copy(bbuf[16:], m.LocalIpAddress) + default: + return nil, fmt.Errorf("unsupported address family: %d", m.AddressFamily) + } + return append(buf, bbuf...), nil +} + +func newBGP4MPHeader(peeras, localas uint32, intfindex uint16, peerip, localip string, isAS4 bool) (*BGP4MPHeader, error) { + var af uint16 + paddr := net.ParseIP(peerip).To4() + laddr := net.ParseIP(localip).To4() + if paddr != nil && laddr != nil { + af = AFI_IP + } else { + paddr = net.ParseIP(peerip).To16() + laddr = net.ParseIP(localip).To16() + if paddr != nil && laddr != nil { + af = AFI_IP6 + } else { + return nil, fmt.Errorf("Peer IP Address and Local IP Address must have the same address family") + } + } + return &BGP4MPHeader{ + PeerAS: peeras, + LocalAS: localas, + InterfaceIndex: intfindex, + AddressFamily: af, + PeerIpAddress: paddr, + LocalIpAddress: laddr, + isAS4: isAS4, + }, nil +} + +type BGP4MPStateChange struct { + *BGP4MPHeader + OldState BGPState + NewState BGPState +} + +func (m *BGP4MPStateChange) DecodeFromBytes(data []byte) error { + rest, err := m.decodeFromBytes(data) + if err != nil { + return err + } + if len(rest) < 4 { + return fmt.Errorf("Not all BGP4MPStateChange bytes available") + } + m.OldState = BGPState(binary.BigEndian.Uint16(rest[:2])) + m.NewState = BGPState(binary.BigEndian.Uint16(rest[2:4])) + return nil +} + +func (m *BGP4MPStateChange) Serialize() ([]byte, error) { + buf, err := m.serialize() + if err != nil { + return nil, err + } + bbuf, err := packValues([]interface{}{m.OldState, m.NewState}) + if err != nil { + return nil, err + } + return append(buf, bbuf...), nil +} + +func NewBGP4MPStateChange(peeras, localas uint32, intfindex uint16, peerip, localip string, isAS4 bool, oldstate, newstate BGPState) *BGP4MPStateChange { + header, _ := newBGP4MPHeader(peeras, localas, intfindex, peerip, localip, isAS4) + return &BGP4MPStateChange{ + BGP4MPHeader: header, + OldState: oldstate, + NewState: newstate, + } +} + +type BGP4MPMessage struct { + *BGP4MPHeader + BGPMessage *BGPMessage + isLocal bool +} + +func (m *BGP4MPMessage) DecodeFromBytes(data []byte) error { + rest, err := m.decodeFromBytes(data) + if err != nil { + return err + } + + if len(rest) < BGP_HEADER_LENGTH { + return fmt.Errorf("Not all BGP4MPMessageAS4 bytes available") + } + + msg, err := ParseBGPMessage(rest) + if err != nil { + return err + } + m.BGPMessage = msg + return nil +} + +func (m *BGP4MPMessage) Serialize() ([]byte, error) { + buf, err := m.serialize() + if err != nil { + return nil, err + } + bbuf, err := m.BGPMessage.Serialize() + if err != nil { + return nil, err + } + return append(buf, bbuf...), nil +} + +func NewBGP4MPMessage(peeras, localas uint32, intfindex uint16, peerip, localip string, isAS4 bool, msg *BGPMessage) *BGP4MPMessage { + header, _ := newBGP4MPHeader(peeras, localas, intfindex, peerip, localip, isAS4) + return &BGP4MPMessage{ + BGP4MPHeader: header, + BGPMessage: msg, + } +} + +func NewBGP4MPMessageLocal(peeras, localas uint32, intfindex uint16, peerip, localip string, isAS4 bool, msg *BGPMessage) *BGP4MPMessage { + header, _ := newBGP4MPHeader(peeras, localas, intfindex, peerip, localip, isAS4) + return &BGP4MPMessage{ + BGP4MPHeader: header, + BGPMessage: msg, + isLocal: true, + } +} + +func (m *BGP4MPMessage) String() string { + title := "BGP4MP_MSG" + if m.isAS4 { + title += "_AS4" + } + if m.isLocal { + title += "_LOCAL" + } + return fmt.Sprintf("%s: PeerAS [%d] LocalAS [%d] InterfaceIndex [%d] PeerIP [%s] LocalIP [%s] BGPMessage [%s]", title, m.PeerAS, m.LocalAS, m.InterfaceIndex, m.PeerIpAddress, m.LocalIpAddress, m.BGPMessage) +} + +func ParseMRTBody(h *MRTHeader, data []byte) (*MRTMessage, error) { + if len(data) < int(h.Len) { + return nil, fmt.Errorf("Not all MRT message bytes available. expected: %d, actual: %d", int(h.Len), len(data)) + } + msg := &MRTMessage{Header: *h} + switch h.Type { + case TABLE_DUMPv2: + subType := MRTSubTypeTableDumpv2(h.SubType) + rf := RouteFamily(0) + switch subType { + case PEER_INDEX_TABLE: + msg.Body = &PeerIndexTable{} + case RIB_IPV4_UNICAST: + rf = RF_IPv4_UC + case RIB_IPV4_MULTICAST: + rf = RF_IPv4_MC + case RIB_IPV6_UNICAST: + rf = RF_IPv6_UC + case RIB_IPV6_MULTICAST: + rf = RF_IPv6_MC + case RIB_GENERIC: + default: + return nil, fmt.Errorf("unsupported table dumpv2 subtype: %s\n", subType) + } + + if subType != PEER_INDEX_TABLE { + msg.Body = &Rib{ + RouteFamily: rf, + } + } + case BGP4MP: + subType := MRTSubTypeBGP4MP(h.SubType) + isAS4 := true + switch subType { + case STATE_CHANGE: + isAS4 = false + fallthrough + case STATE_CHANGE_AS4: + msg.Body = &BGP4MPStateChange{ + BGP4MPHeader: &BGP4MPHeader{isAS4: isAS4}, + } + case MESSAGE: + isAS4 = false + fallthrough + case MESSAGE_AS4: + msg.Body = &BGP4MPMessage{ + BGP4MPHeader: &BGP4MPHeader{isAS4: isAS4}, + } + case MESSAGE_LOCAL: + isAS4 = false + fallthrough + case MESSAGE_AS4_LOCAL: + msg.Body = &BGP4MPMessage{ + BGP4MPHeader: &BGP4MPHeader{isAS4: isAS4}, + isLocal: true, + } + default: + return nil, fmt.Errorf("unsupported bgp4mp subtype: %s\n", subType) + } + default: + return nil, fmt.Errorf("unsupported type: %s\n", h.Type) + } + err := msg.Body.DecodeFromBytes(data) + if err != nil { + return nil, err + } + return msg, nil +} |