diff options
Diffstat (limited to 'server/fsm.go')
| -rw-r--r-- | server/fsm.go | 75 |
1 files changed, 55 insertions, 20 deletions
diff --git a/server/fsm.go b/server/fsm.go index f623f399..e1b85cd0 100644 --- a/server/fsm.go +++ b/server/fsm.go @@ -600,6 +600,30 @@ func readAll(conn net.Conn, length int) ([]byte, error) { return buf, nil } +func getPathAttrFromBGPUpdate(m *bgp.BGPUpdate, typ bgp.BGPAttrType) bgp.PathAttributeInterface { + for _, a := range m.PathAttributes { + if a.GetType() == typ { + return a + } + } + return nil +} + +func hasOwnASLoop(ownAS uint32, limit int, aspath *bgp.PathAttributeAsPath) bool { + cnt := 0 + for _, i := range aspath.Value { + for _, as := range i.(*bgp.As4PathParam).AS { + if as == ownAS { + cnt++ + if cnt > limit { + return true + } + } + } + } + return false +} + func (h *FSMHandler) recvMessageWithError() (*FsmMsg, error) { sendToErrorCh := func(reason FsmStateReason) { // probably doesn't happen but be cautious @@ -671,6 +695,11 @@ func (h *FSMHandler) recvMessageWithError() (*FsmMsg, error) { case bgp.BGP_MSG_UPDATE: body := m.Body.(*bgp.BGPUpdate) confedCheck := !config.IsConfederationMember(h.fsm.gConf, h.fsm.pConf) && config.IsEBGPPeer(h.fsm.gConf, h.fsm.pConf) + + fmsg.payload = make([]byte, len(headerBuf)+len(bodyBuf)) + copy(fmsg.payload, headerBuf) + copy(fmsg.payload[len(headerBuf):], bodyBuf) + _, err = bgp.ValidateUpdateMsg(body, h.fsm.rfMap, confedCheck) if err != nil { log.WithFields(log.Fields{ @@ -680,28 +709,34 @@ func (h *FSMHandler) recvMessageWithError() (*FsmMsg, error) { "error": err, }).Warn("malformed BGP update message") fmsg.MsgData = err - } else { - // FIXME: we should use the original message for bmp/mrt - table.UpdatePathAttrs4ByteAs(body) - err = table.UpdatePathAggregator4ByteAs(body) - if err == nil { - fmsg.PathList = table.ProcessMessage(m, h.fsm.peerInfo, fmsg.timestamp) - id := h.fsm.pConf.Config.NeighborAddress - for _, path := range fmsg.PathList { - if path.IsEOR() { - continue - } - if h.fsm.policy.ApplyPolicy(id, table.POLICY_DIRECTION_IN, path, nil) == nil { - path.Filter(id, table.POLICY_DIRECTION_IN) - } - } - } else { - fmsg.MsgData = err + return fmsg, err + } + + table.UpdatePathAttrs4ByteAs(body) + if err = table.UpdatePathAggregator4ByteAs(body); err != nil { + fmsg.MsgData = err + return fmsg, err + } + + // RFC4271 9.1.2 Phase 2: Route Selection + // + // If the AS_PATH attribute of a BGP route contains an AS loop, the BGP + // route should be excluded from the Phase 2 decision function. + var asLoop bool + if attr := getPathAttrFromBGPUpdate(body, bgp.BGP_ATTR_TYPE_AS_PATH); attr != nil { + asLoop = hasOwnASLoop(h.fsm.peerInfo.LocalAS, int(h.fsm.pConf.AsPathOptions.Config.AllowOwnAs), attr.(*bgp.PathAttributeAsPath)) + } + + fmsg.PathList = table.ProcessMessage(m, h.fsm.peerInfo, fmsg.timestamp) + id := h.fsm.pConf.Config.NeighborAddress + for _, path := range fmsg.PathList { + if path.IsEOR() { + continue + } + if asLoop || (h.fsm.policy.ApplyPolicy(id, table.POLICY_DIRECTION_IN, path, nil) == nil) { + path.Filter(id, table.POLICY_DIRECTION_IN) } } - fmsg.payload = make([]byte, len(headerBuf)+len(bodyBuf)) - copy(fmsg.payload, headerBuf) - copy(fmsg.payload[len(headerBuf):], bodyBuf) fallthrough case bgp.BGP_MSG_KEEPALIVE: // if the length of h.holdTimerResetCh |