Merge pull request #59 from bio-routing/unfuck/as_loop_detection

Unfuck iBGP loop detection et all

.travis.yml

@@ -22,6 +22,7 @@ script:
 - mkdir -p $HOME/gopath/src/github.com/bio-routing/
 - ln -s $TRAVIS_BUILD_DIR $HOME/gopath/src/github.com/bio-routing/bio-rd || true
 - cp .bazelrc.travis .bazelrc
+- bazel test //...
 - bazel coverage //...
 - bazel build //vendor/github.com/q3k/goveralls
 - bazel-bin/vendor/github.com/q3k/goveralls/linux_amd64_stripped/goveralls -coverprofile=$(find bazel-testlogs/ -iname coverage.dat -or -iname baseline_coverage.dat | paste -sd ',') -merge=false

protocols/bgp/server/BUILD.bazel

@@ -33,6 +33,7 @@ go_library(
         "//routingtable/adjRIBIn:go_default_library",
         "//routingtable/adjRIBOut:go_default_library",
         "//routingtable/filter:go_default_library",
+        "//routingtable/locRIB:go_default_library",
         "//vendor/github.com/sirupsen/logrus:go_default_library",
     ],
 )

protocols/bgp/server/fsm.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/bio-routing/bio-rd/protocols/bgp/packet"
 	"github.com/bio-routing/bio-rd/routingtable"
+	"github.com/bio-routing/bio-rd/routingtable/locRIB"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -63,7 +64,7 @@ type FSM struct {
 	ribsInitialized bool
 	adjRIBIn        routingtable.RouteTableClient
 	adjRIBOut       routingtable.RouteTableClient
-	rib             routingtable.RouteTableClient
+	rib             *locRIB.LocRIB
 	updateSender    routingtable.RouteTableClient
 
 	neighborID uint32

protocols/bgp/server/fsm_established.go

@@ -55,7 +55,10 @@ func (s establishedState) run() (state, string) {
 }
 
 func (s *establishedState) init() error {
-	s.fsm.adjRIBIn = adjRIBIn.New(s.fsm.peer.importFilter)
+	contributingASNs := s.fsm.rib.GetContributingASNs()
+
+	s.fsm.adjRIBIn = adjRIBIn.New(s.fsm.peer.importFilter, contributingASNs)
+	contributingASNs.Add(s.fsm.peer.localASN)
 	s.fsm.adjRIBIn.Register(s.fsm.rib)
 
 	host, _, err := net.SplitHostPort(s.fsm.con.LocalAddr().String())
@@ -96,6 +99,7 @@ func (s *establishedState) init() error {
 }
 
 func (s *establishedState) uninit() {
+	s.fsm.rib.GetContributingASNs().Remove(s.fsm.peer.localASN)
 	s.fsm.adjRIBIn.Unregister(s.fsm.rib)
 	s.fsm.rib.Unregister(s.fsm.adjRIBOut)
 	s.fsm.adjRIBOut.Unregister(s.fsm.updateSender)

protocols/bgp/server/peer.go

@@ -9,6 +9,7 @@ import (
 	"github.com/bio-routing/bio-rd/protocols/bgp/packet"
 	"github.com/bio-routing/bio-rd/routingtable"
 	"github.com/bio-routing/bio-rd/routingtable/filter"
+	"github.com/bio-routing/bio-rd/routingtable/locRIB"
 )
 
 type PeerInfo struct {
@@ -27,7 +28,7 @@ type peer struct {
 	fsms   []*FSM
 	fsmsMu sync.Mutex
 
-	rib               routingtable.RouteTableClient
+	rib               *locRIB.LocRIB
 	routerID          uint32
 	addPathSend       routingtable.ClientOptions
 	addPathRecv       bool
@@ -100,7 +101,7 @@ func isEstablishedState(s state) bool {
 
 // NewPeer creates a new peer with the given config. If an connection is established, the adjRIBIN of the peer is connected
 // to the given rib. To actually connect the peer, call Start() on the returned peer.
-func newPeer(c config.Peer, rib routingtable.RouteTableClient, server *bgpServer) (*peer, error) {
+func newPeer(c config.Peer, rib *locRIB.LocRIB, server *bgpServer) (*peer, error) {
 	if c.LocalAS == 0 {
 		c.LocalAS = server.localASN
 	}

protocols/bgp/server/server.go

@@ -9,7 +9,7 @@ import (
 
 	"github.com/bio-routing/bio-rd/config"
 	"github.com/bio-routing/bio-rd/protocols/bgp/packet"
-	"github.com/bio-routing/bio-rd/routingtable"
+	"github.com/bio-routing/bio-rd/routingtable/locRIB"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -28,7 +28,7 @@ type bgpServer struct {
 type BGPServer interface {
 	RouterID() uint32
 	Start(*config.Global) error
-	AddPeer(config.Peer, routingtable.RouteTableClient) error
+	AddPeer(config.Peer, *locRIB.LocRIB) error
 	GetPeerInfoAll() map[string]PeerInfo
 }
 
@@ -112,7 +112,7 @@ func (b *bgpServer) incomingConnectionWorker() {
 	}
 }
 
-func (b *bgpServer) AddPeer(c config.Peer, rib routingtable.RouteTableClient) error {
+func (b *bgpServer) AddPeer(c config.Peer, rib *locRIB.LocRIB) error {
 	peer, err := newPeer(c, rib, b)
 	if err != nil {
 		return err

protocols/bgp/server/server_test.go

@@ -11,23 +11,6 @@ import (
 	"github.com/bio-routing/bio-rd/routingtable/locRIB"
 )
 
-func TestBgpServerConfigCheck(t *testing.T) {
-	s := NewBgpServer()
-
-	err := s.Start(&config.Global{})
-	if err == nil {
-		t.Fatalf("server with empty config should not start")
-	}
-
-	err = s.Start(&config.Global{
-		LocalASN: 204880,
-		RouterID: 2137,
-	})
-	if err != nil {
-		t.Fatalf("server should have started, got err: %v", err)
-	}
-}
-
 func TestBgpServerPeerSnapshot(t *testing.T) {
 	s := NewBgpServer()
 	err := s.Start(&config.Global{

routingtable/BUILD.bazel

@@ -5,6 +5,7 @@ go_library(
     srcs = [
         "client_interface.go",
         "client_manager.go",
+        "contributing_asn_list.go",
         "neighbor.go",
         "rib_interface.go",
         "table.go",
@@ -25,6 +26,7 @@ go_test(
     name = "go_default_test",
     srcs = [
         "client_manager_test.go",
+        "contributing_asn_list_test.go",
         "table_test.go",
         "trie_test.go",
         "update_helper_test.go",

routingtable/adjRIBIn/BUILD.bazel

@@ -7,6 +7,7 @@ go_library(
     visibility = ["//visibility:public"],
     deps = [
         "//net:go_default_library",
+        "//protocols/bgp/packet:go_default_library",
         "//route:go_default_library",
         "//routingtable:go_default_library",
         "//routingtable/filter:go_default_library",

routingtable/adjRIBIn/adj_rib_in.go

@@ -3,6 +3,7 @@ package adjRIBIn
 import (
 	"sync"
 
+	"github.com/bio-routing/bio-rd/protocols/bgp/packet"
 	"github.com/bio-routing/bio-rd/routingtable/filter"
 
 	"github.com/bio-routing/bio-rd/net"
@@ -14,16 +15,18 @@ import (
 // AdjRIBIn represents an Adjacency RIB In as described in RFC4271
 type AdjRIBIn struct {
 	routingtable.ClientManager
-	rt           *routingtable.RoutingTable
-	mu           sync.RWMutex
-	exportFilter *filter.Filter
+	rt               *routingtable.RoutingTable
+	mu               sync.RWMutex
+	exportFilter     *filter.Filter
+	contributingASNs *routingtable.ContributingASNs
 }
 
 // New creates a new Adjacency RIB In
-func New(exportFilter *filter.Filter) *AdjRIBIn {
+func New(exportFilter *filter.Filter, contributingASNs *routingtable.ContributingASNs) *AdjRIBIn {
 	a := &AdjRIBIn{
-		rt:           routingtable.NewRoutingTable(),
-		exportFilter: exportFilter,
+		rt:               routingtable.NewRoutingTable(),
+		exportFilter:     exportFilter,
+		contributingASNs: contributingASNs,
 	}
 	a.ClientManager = routingtable.NewClientManager(a)
 	return a
@@ -65,12 +68,32 @@ func (a *AdjRIBIn) AddPath(pfx net.Prefix, p *route.Path) error {
 		return nil
 	}
 
+	// Bail out - for all clients for now - if any of our ASNs is within the path
+	if a.ourASNsInPath(p) {
+		return nil
+	}
+
 	for _, client := range a.ClientManager.Clients() {
 		client.AddPath(pfx, p)
 	}
 	return nil
 }
 
+func (a *AdjRIBIn) ourASNsInPath(p *route.Path) bool {
+	// Don't accept path via iBGP which contain our ASN
+	ASPathAttr, _ := packet.ParseASPathStr(p.BGPPath.ASPath)
+
+	for _, pathSegment := range ASPathAttr.Value.(packet.ASPath) {
+		for _, asn := range pathSegment.ASNs {
+			if a.contributingASNs.IsContributingASN(asn) {
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
 // RemovePath removes the path for prefix `pfx`
 func (a *AdjRIBIn) RemovePath(pfx net.Prefix, p *route.Path) bool {
 	a.mu.Lock()

routingtable/adjRIBIn/adj_rib_in_test.go

@@ -115,7 +115,7 @@ func TestAddPath(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		adjRIBIn := New(filter.NewAcceptAllFilter())
+		adjRIBIn := New(filter.NewAcceptAllFilter(), routingtable.NewContributingASNs())
 		mc := NewRTMockClient()
 		adjRIBIn.ClientManager.Register(mc)
 
@@ -206,7 +206,7 @@ func TestRemovePath(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		adjRIBIn := New(filter.NewAcceptAllFilter())
+		adjRIBIn := New(filter.NewAcceptAllFilter(), routingtable.NewContributingASNs())
 		for _, route := range test.routes {
 			adjRIBIn.AddPath(route.Prefix(), route.Paths()[0])
 		}

routingtable/contributing_asn_list.go

+package routingtable
+
+import (
+	"fmt"
+	"math"
+	"sync"
+)
+
+type contributingASN struct {
+	asn   uint32
+	count uint32
+}
+
+// ContributingASNs contains a list of contributing ASN to a LocRIB to check ASPaths for possible routing loops.
+type ContributingASNs struct {
+	contributingASNs     []*contributingASN
+	contributingASNsLock sync.RWMutex
+}
+
+// NewContributingASNs creates a list of contributing ASNs to a LocRIB for routing loop prevention.
+func NewContributingASNs() *ContributingASNs {
+	c := &ContributingASNs{
+		contributingASNs: []*contributingASN{},
+	}
+
+	return c
+}
+
+// Add a new ASN to the list of contributing ASNs or add the ref count of an existing one.
+func (c *ContributingASNs) Add(asn uint32) {
+	c.contributingASNsLock.Lock()
+	defer c.contributingASNsLock.Unlock()
+
+	for _, cASN := range c.contributingASNs {
+		if cASN.asn == asn {
+			cASN.count++
+
+			if cASN.count == math.MaxUint32 {
+				panic(fmt.Sprintf("Contributing ASNs counter overflow triggered for AS %d. Dyning of shame.", asn))
+			}
+
+			return
+		}
+	}
+
+	c.contributingASNs = append(c.contributingASNs, &contributingASN{
+		asn:   asn,
+		count: 1,
+	})
+}
+
+// Remove a ASN to the list of contributing ASNs or decrement the ref count of an existing one.
+func (c *ContributingASNs) Remove(asn uint32) {
+	c.contributingASNsLock.Lock()
+	defer c.contributingASNsLock.Unlock()
+
+	asnList := c.contributingASNs
+
+	for i, cASN := range asnList {
+		if cASN.asn != asn {
+			continue
+		}
+
+		cASN.count--
+
+		if cASN.count == 0 {
+			copy(asnList[i:], asnList[i+1:])
+			asnList = asnList[:len(asnList)]
+			c.contributingASNs = asnList[:len(asnList)-1]
+		}
+
+		return
+	}
+}
+
+// IsContributingASN checks if  a given ASN is part of the contributing ASNs
+func (c *ContributingASNs) IsContributingASN(asn uint32) bool {
+	c.contributingASNsLock.RLock()
+	defer c.contributingASNsLock.RUnlock()
+
+	for _, cASN := range c.contributingASNs {
+		if asn == cASN.asn {
+			return true
+		}
+	}
+
+	return false
+}

routingtable/contributing_asn_list_test.go

+package routingtable
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestFancy(t *testing.T) {
+	c := NewContributingASNs()
+
+	tests := []struct {
+		runCmd func()
+		expect func() bool
+		msg    string
+	}{
+		// Empty list
+		{
+			runCmd: func() {},
+			expect: func() bool { return !c.IsContributingASN(41981) },
+			msg:    "AS41981 shouldn't be contributing yet.",
+		},
+
+		// Add and remove one ASN
+		{
+			runCmd: func() { c.Add(41981) },
+			expect: func() bool { return c.IsContributingASN(41981) },
+			msg:    "AS41981 should be contributing",
+		},
+		{
+			runCmd: func() { c.Remove(41981) },
+			expect: func() bool { return !c.IsContributingASN(41981) },
+			msg:    "AS41981 shouldn't be contributing no more.",
+		},
+
+		// Two ASNs present
+		{
+			runCmd: func() { c.Add(41981) },
+			expect: func() bool { return c.IsContributingASN(41981) },
+			msg:    "AS41981 should be contributing",
+		},
+		{
+			runCmd: func() { c.Add(201701) },
+			expect: func() bool { return c.IsContributingASN(41981) },
+			msg:    "AS201701 should be contributing",
+		},
+
+		// Add AS41981 2nd time
+		{
+			runCmd: func() { c.Add(41981) },
+			expect: func() bool { return c.IsContributingASN(41981) },
+			msg:    "AS41981 should be still contributing",
+		},
+		{
+			runCmd: func() {},
+			expect: func() bool { return c.contributingASNs[0].asn == 41981 },
+			msg:    "AS41981 is first ASN in list",
+		},
+		{
+			runCmd: func() { fmt.Printf("%+v", c.contributingASNs) },
+			expect: func() bool { return c.contributingASNs[0].count == 2 },
+			msg:    "AS41981 should be present twice.",
+		},
+	}
+
+	for i, test := range tests {
+		test.runCmd()
+		if !test.expect() {
+			t.Errorf("Test %d failed: %v", i, test.msg)
+		}
+	}
+}

routingtable/locRIB/loc_rib.go

@@ -14,19 +14,26 @@ import (
 // LocRIB represents a routing information base
 type LocRIB struct {
 	routingtable.ClientManager
-	rt *routingtable.RoutingTable
-	mu sync.RWMutex
+	rt               *routingtable.RoutingTable
+	mu               sync.RWMutex
+	contributingASNs *routingtable.ContributingASNs
 }
 
 // New creates a new routing information base
 func New() *LocRIB {
 	a := &LocRIB{
-		rt: routingtable.NewRoutingTable(),
+		rt:               routingtable.NewRoutingTable(),
+		contributingASNs: routingtable.NewContributingASNs(),
 	}
 	a.ClientManager = routingtable.NewClientManager(a)
 	return a
 }
 
+// GetContributingASNs returns a pointer to the list of contributing ASNs
+func (a *LocRIB) GetContributingASNs() *routingtable.ContributingASNs {
+	return a.contributingASNs
+}
+
 //Count routes from the LocRIP
 func (a *LocRIB) Count() uint64 {
 	a.mu.RLock()

vendor/github.com/Masterminds/semver/BUILD.bazel

@@ -13,7 +13,7 @@ go_library(
         "union.go",
         "version.go",
     ],
-    importmap = "vendor/github.com/Masterminds/semver",
+    importmap = "github.com/bio-routing/bio-rd/vendor/github.com/Masterminds/semver",
     importpath = "github.com/Masterminds/semver",
     visibility = ["//visibility:public"],
 )

vendor/github.com/Masterminds/vcs/BUILD.bazel

@@ -12,7 +12,7 @@ go_library(
         "vcs_local_lookup.go",
         "vcs_remote_lookup.go",
     ],
-    importmap = "vendor/github.com/Masterminds/vcs",
+    importmap = "github.com/bio-routing/bio-rd/vendor/github.com/Masterminds/vcs",
     importpath = "github.com/Masterminds/vcs",
     visibility = ["//visibility:public"],
 )

vendor/github.com/armon/go-radix/BUILD.bazel

@@ -3,7 +3,7 @@ load("@io_bazel_rules_go//go:def.bzl", "go_library")
 go_library(
     name = "go_default_library",
     srcs = ["radix.go"],
-    importmap = "vendor/github.com/armon/go-radix",
+    importmap = "github.com/bio-routing/bio-rd/vendor/github.com/armon/go-radix",
     importpath = "github.com/armon/go-radix",
     visibility = ["//visibility:public"],
 )

vendor/github.com/boltdb/bolt/BUILD.bazel

@@ -26,7 +26,7 @@ go_library(
         "page.go",
         "tx.go",
     ],
-    importmap = "vendor/github.com/boltdb/bolt",
+    importmap = "github.com/bio-routing/bio-rd/vendor/github.com/boltdb/bolt",
     importpath = "github.com/boltdb/bolt",
     visibility = ["//visibility:public"],
     deps = select({

vendor/github.com/davecgh/go-spew/spew/BUILD.bazel

@@ -11,7 +11,7 @@ go_library(
         "format.go",
         "spew.go",
     ],
-    importmap = "vendor/github.com/davecgh/go-spew/spew",
+    importmap = "github.com/bio-routing/bio-rd/vendor/github.com/davecgh/go-spew/spew",
     importpath = "github.com/davecgh/go-spew/spew",
     visibility = ["//visibility:public"],
 )

vendor/github.com/go-yaml/yaml/BUILD.bazel

@@ -17,7 +17,7 @@ go_library(
         "yamlh.go",
         "yamlprivateh.go",
     ],
-    importmap = "vendor/github.com/go-yaml/yaml",
+    importmap = "github.com/bio-routing/bio-rd/vendor/github.com/go-yaml/yaml",
     importpath = "github.com/go-yaml/yaml",
     visibility = ["//visibility:public"],
 )