From ef9400a00149855505de10ec218c07e1fb46203b Mon Sep 17 00:00:00 2001
From: Daniel Czerwonk <daniel@dan-nrw.de>
Date: Mon, 25 Jun 2018 21:21:15 +0200
Subject: [PATCH] as path refactoring
---
protocols/bgp/packet/as_path.go | 44 ++++++++++++
protocols/bgp/packet/bgp.go | 7 --
protocols/bgp/packet/path_attributes.go | 93 -------------------------
protocols/bgp/server/fsm_established.go | 4 +-
protocols/bgp/server/update_helper.go | 11 ++-
route/{bgp.go => bgp_path.go} | 35 +++++++---
routingtable/adjRIBIn/adj_rib_in.go | 6 +-
routingtable/adjRIBOut/adj_rib_out.go | 2 +-
8 files changed, 78 insertions(+), 124 deletions(-)
create mode 100644 protocols/bgp/packet/as_path.go
rename route/{bgp.go => bgp_path.go} (84%)
diff --git a/protocols/bgp/packet/as_path.go b/protocols/bgp/packet/as_path.go
new file mode 100644
index 00000000..0cdfc96a
--- /dev/null
+++ b/protocols/bgp/packet/as_path.go
@@ -0,0 +1,44 @@
+package packet
+
+import "fmt"
+
+type ASPath []ASPathSegment
+
+type ASPathSegment struct {
+ Type uint8
+ Count uint8
+ ASNs []uint32
+}
+
+func (pa ASPath) String() (ret string) {
+ for _, p := range pa {
+ if p.Type == ASSet {
+ ret += " ("
+ }
+ n := len(p.ASNs)
+ for i, asn := range p.ASNs {
+ if i < n-1 {
+ ret += fmt.Sprintf("%d ", asn)
+ continue
+ }
+ ret += fmt.Sprintf("%d", asn)
+ }
+ if p.Type == ASSet {
+ ret += ")"
+ }
+ }
+
+ return
+}
+
+func (pa ASPath) Length() (ret uint16) {
+ for _, p := range pa {
+ if p.Type == ASSet {
+ ret++
+ continue
+ }
+ ret += uint16(len(p.ASNs))
+ }
+
+ return
+}
diff --git a/protocols/bgp/packet/bgp.go b/protocols/bgp/packet/bgp.go
index 8082f5dd..8aabec7f 100644
--- a/protocols/bgp/packet/bgp.go
+++ b/protocols/bgp/packet/bgp.go
@@ -173,13 +173,6 @@ type NLRIAddPath struct {
Next *NLRIAddPath
}
-type ASPath []ASPathSegment
-type ASPathSegment struct {
- Type uint8
- Count uint8
- ASNs []uint32
-}
-
type Aggretator struct {
Addr uint32
ASN uint16
diff --git a/protocols/bgp/packet/path_attributes.go b/protocols/bgp/packet/path_attributes.go
index a859f4a0..fa5e9f0e 100644
--- a/protocols/bgp/packet/path_attributes.go
+++ b/protocols/bgp/packet/path_attributes.go
@@ -3,7 +3,6 @@ package packet
import (
"bytes"
"fmt"
- "strconv"
"strings"
"github.com/taktv6/tflow2/convert"
@@ -344,39 +343,6 @@ func (pa *PathAttribute) setLength(buf *bytes.Buffer) (int, error) {
return bytesRead, nil
}
-func (pa *PathAttribute) ASPathString() (ret string) {
- for _, p := range pa.Value.(ASPath) {
- if p.Type == ASSet {
- ret += " ("
- }
- n := len(p.ASNs)
- for i, asn := range p.ASNs {
- if i < n-1 {
- ret += fmt.Sprintf("%d ", asn)
- continue
- }
- ret += fmt.Sprintf("%d", asn)
- }
- if p.Type == ASSet {
- ret += ")"
- }
- }
-
- return
-}
-
-func (pa *PathAttribute) ASPathLen() (ret uint16) {
- for _, p := range pa.Value.(ASPath) {
- if p.Type == ASSet {
- ret++
- continue
- }
- ret += uint16(len(p.ASNs))
- }
-
- return
-}
-
func (a *PathAttribute) CommunityString() string {
s := ""
for _, com := range a.Value.([]uint32) {
@@ -587,57 +553,6 @@ func (pa *PathAttribute) serializeLargeCommunities(buf *bytes.Buffer) uint8 {
return length
}
-// ParseASPathStr converts an AS path from string representation info an PathAttribute object
-func ParseASPathStr(asPathString string) (*PathAttribute, error) {
- asPath := ASPath{}
-
- currentType := ASSequence
- newSegmentNeeded := true
- currentSegment := -1
- for _, asn := range strings.Split(asPathString, " ") {
- if asn == "" {
- continue
- }
-
- if isBeginOfASSet(asn) {
- currentType = ASSet
- newSegmentNeeded = true
- asn = strings.Replace(asn, "(", "", 1)
- }
-
- if newSegmentNeeded {
- seg := ASPathSegment{
- Type: uint8(currentType),
- ASNs: make([]uint32, 0),
- }
- asPath = append(asPath, seg)
- currentSegment++
- newSegmentNeeded = false
- }
-
- if isEndOfASSset(asn) {
- currentType = ASSequence
- newSegmentNeeded = true
- asn = strings.Replace(asn, ")", "", 1)
- }
-
- numericASN, err := strconv.Atoi(asn)
- if err != nil {
- return nil, fmt.Errorf("Unable to convert ASN: %v", err)
- }
- asPath[currentSegment].ASNs = append(asPath[currentSegment].ASNs, uint32(numericASN))
-
- if len(asPath[currentSegment].ASNs) == MaxASNsSegment {
- newSegmentNeeded = true
- }
- }
-
- return &PathAttribute{
- TypeCode: ASPathAttr,
- Value: asPath,
- }, nil
-}
-
func LargeCommunityAttributeForString(s string) (*PathAttribute, error) {
strs := strings.Split(s, " ")
coms := make([]LargeCommunity, len(strs))
@@ -656,14 +571,6 @@ func LargeCommunityAttributeForString(s string) (*PathAttribute, error) {
}, nil
}
-func isBeginOfASSet(asPathPart string) bool {
- return strings.Contains(asPathPart, "(")
-}
-
-func isEndOfASSset(asPathPart string) bool {
- return strings.Contains(asPathPart, ")")
-}
-
func fourBytesToUint32(address [4]byte) uint32 {
return uint32(address[0])<<24 + uint32(address[1])<<16 + uint32(address[2])<<8 + uint32(address[3])
}
diff --git a/protocols/bgp/server/fsm_established.go b/protocols/bgp/server/fsm_established.go
index c1507eb5..9ce739ec 100644
--- a/protocols/bgp/server/fsm_established.go
+++ b/protocols/bgp/server/fsm_established.go
@@ -230,8 +230,8 @@ func (s *establishedState) updates(u *packet.BGPUpdate) {
case packet.NextHopAttr:
path.BGPPath.NextHop = pa.Value.(uint32)
case packet.ASPathAttr:
- path.BGPPath.ASPath = pa.ASPathString()
- path.BGPPath.ASPathLen = pa.ASPathLen()
+ path.BGPPath.ASPath = pa.Value.(packet.ASPath)
+ path.BGPPath.ASPathLen = path.BGPPath.ASPath.Length()
case packet.CommunitiesAttr:
path.BGPPath.Communities = pa.Value.([]uint32)
case packet.LargeCommunitiesAttr:
diff --git a/protocols/bgp/server/update_helper.go b/protocols/bgp/server/update_helper.go
index 393df4e9..2f46e811 100644
--- a/protocols/bgp/server/update_helper.go
+++ b/protocols/bgp/server/update_helper.go
@@ -3,7 +3,6 @@ package server
import (
"fmt"
"io"
- "strings"
"github.com/bio-routing/bio-rd/protocols/bgp/packet"
"github.com/bio-routing/bio-rd/route"
@@ -11,22 +10,22 @@ import (
)
func pathAttribues(p *route.Path) (*packet.PathAttribute, error) {
- asPathPA, err := packet.ParseASPathStr(strings.TrimRight(p.BGPPath.ASPath, " "))
- if err != nil {
- return nil, fmt.Errorf("Unable to parse AS path: %v", err)
+ asPath := &packet.PathAttribute{
+ TypeCode: packet.ASPathAttr,
+ Value: p.BGPPath.ASPath,
}
origin := &packet.PathAttribute{
TypeCode: packet.OriginAttr,
Value: p.BGPPath.Origin,
- Next: asPathPA,
}
+ asPath.Next = origin
nextHop := &packet.PathAttribute{
TypeCode: packet.NextHopAttr,
Value: p.BGPPath.NextHop,
}
- asPathPA.Next = nextHop
+ origin.Next = nextHop
localPref := &packet.PathAttribute{
TypeCode: packet.LocalPrefAttr,
diff --git a/route/bgp.go b/route/bgp_path.go
similarity index 84%
rename from route/bgp.go
rename to route/bgp_path.go
index 3beb6b56..1222487b 100644
--- a/route/bgp.go
+++ b/route/bgp_path.go
@@ -3,9 +3,9 @@ package route
import (
"crypto/sha256"
"fmt"
- "strconv"
"strings"
+ "github.com/bio-routing/bio-rd/protocols/bgp/packet"
"github.com/taktv6/tflow2/convert"
)
@@ -14,7 +14,7 @@ type BGPPath struct {
PathIdentifier uint32
NextHop uint32
LocalPref uint32
- ASPath string
+ ASPath packet.ASPath
ASPathLen uint16
Origin uint8
MED uint32
@@ -155,7 +155,7 @@ func (b *BGPPath) Print() string {
}
ret := fmt.Sprintf("\t\tLocal Pref: %d\n", b.LocalPref)
ret += fmt.Sprintf("\t\tOrigin: %s\n", origin)
- ret += fmt.Sprintf("\t\tAS Path: %s\n", b.ASPath)
+ ret += fmt.Sprintf("\t\tAS Path: %s\n")
nh := uint32To4Byte(b.NextHop)
ret += fmt.Sprintf("\t\tNEXT HOP: %d.%d.%d.%d\n", nh[0], nh[1], nh[2], nh[3])
ret += fmt.Sprintf("\t\tMED: %d\n", b.MED)
@@ -172,16 +172,31 @@ func (b *BGPPath) Prepend(asn uint32, times uint16) {
return
}
- asnStr := strconv.FormatUint(uint64(asn), 10)
+ first := b.ASPath[0]
+ if len(b.ASPath) == 0 || first.Type == packet.ASSet {
+ b.insertNewASSequence()
+ }
+
+ for i := 0; i < int(times); i++ {
+ if len(b.ASPath) == packet.MaxASNsSegment {
+ b.insertNewASSequence()
+ }
+
+ }
+
+ b.ASPathLen = b.ASPath.Length()
+}
- path := make([]string, times+1)
- for i := 0; uint16(i) < times; i++ {
- path[i] = asnStr
+func (b *BGPPath) insertNewASSequence() packet.ASPath {
+ pa := make(packet.ASPath, len(b.ASPath)+1)
+ copy(pa[1:], b.ASPath)
+ pa[0] = packet.ASPathSegment{
+ ASNs: make([]uint32, 0),
+ Count: 0,
+ Type: packet.ASSequence,
}
- path[times] = b.ASPath
- b.ASPath = strings.TrimSuffix(strings.Join(path, " "), " ")
- b.ASPathLen = b.ASPathLen + times
+ return pa
}
func (p *BGPPath) Copy() *BGPPath {
diff --git a/routingtable/adjRIBIn/adj_rib_in.go b/routingtable/adjRIBIn/adj_rib_in.go
index 2d850024..2cf454be 100644
--- a/routingtable/adjRIBIn/adj_rib_in.go
+++ b/routingtable/adjRIBIn/adj_rib_in.go
@@ -3,7 +3,6 @@ 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"
@@ -80,10 +79,7 @@ func (a *AdjRIBIn) AddPath(pfx net.Prefix, p *route.Path) error {
}
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 _, pathSegment := range p.BGPPath.ASPath {
for _, asn := range pathSegment.ASNs {
if a.contributingASNs.IsContributingASN(asn) {
return true
diff --git a/routingtable/adjRIBOut/adj_rib_out.go b/routingtable/adjRIBOut/adj_rib_out.go
index 19b44b8b..088756dc 100644
--- a/routingtable/adjRIBOut/adj_rib_out.go
+++ b/routingtable/adjRIBOut/adj_rib_out.go
@@ -52,7 +52,7 @@ func (a *AdjRIBOut) AddPath(pfx bnet.Prefix, p *route.Path) error {
p = p.Copy()
if !a.neighbor.IBGP && !a.neighbor.RouteServerClient {
- p.BGPPath.ASPath = fmt.Sprintf("%d %s", a.neighbor.LocalASN, p.BGPPath.ASPath)
+ p.BGPPath.Prepend(a.neighbor.LocalASN, 1)
}
if !a.neighbor.IBGP && !a.neighbor.RouteServerClient {
--
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