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Merged
packethog merged 4 commits into from
Jun 11, 2025
Merged

client: prune mcast group immediately on disconnect #555

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0683986
client: prune mcast group immediately on disconnect
packethog Jun 11, 2025
45ecc45
client: fix mcast tests
packethog Jun 11, 2025
6ec90e5
client: nits
packethog Jun 11, 2025
2dce21c
client: more nits
packethog Jun 11, 2025
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98 changes: 75 additions & 23 deletions client/doublezerod/internal/pim/cmd/send/send.go
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Original file line number Diff line number Diff line change
Expand Up @@ -11,13 +11,34 @@ import (
"golang.org/x/net/ipv4"
)

var iface = flag.String("iface", "", "interface to use")
var (
iface = flag.String("iface", "", "interface to use")
group = flag.String("group", "", "multicast group to join/prune")
upstreamNeighbor = flag.String("upstream", "", "upstream neighbor address (for JoinPrune messages)")
rpAddress = flag.String("rp", "10.0.0.0", "RP address defaults to 10.0.0.0")
join = flag.Bool("join", false, "send a join message")
prune = flag.Bool("prune", false, "send a prune message")
holdtime = flag.Int("holdtime", 120, "holdtime for JoinPrune messages (default 120 seconds)")
)

func main() {
flag.Parse()
if *iface == "" {
log.Fatalf("interface not specified")
}

if *group == "" {
log.Fatalf("multicast group not specified")
}

if *upstreamNeighbor == "" {
log.Fatalf("upstream neighbor address not specified")
}

if (!*join && !*prune) || (*join && *prune) {
log.Fatalf("either -join or -prune must be specified")
}

c, err := net.ListenPacket("ip4:103", "0.0.0.0")
if err != nil {
log.Fatalf("failed to listen: %v", err)
Expand Down Expand Up @@ -88,32 +109,63 @@ func main() {

buf = gopacket.NewSerializeBuffer()

join := &pim.JoinPruneMessage{
UpstreamNeighborAddress: net.IP([]byte{169, 254, 1, 3}),
NumGroups: 1,
Reserved: 0,
Holdtime: 210,
Groups: []pim.Group{
{
AddressFamily: 1,
NumJoinedSources: 1,
NumPrunedSources: 0,
MaskLength: 32,
MulticastGroupAddress: net.IP([]byte{239, 0, 0, 3}),
Joins: []pim.SourceAddress{
{
AddressFamily: 1,
Flags: 7,
MaskLength: 32,
EncodingType: 0,
Address: pim.RpAddress,
var msg *pim.JoinPruneMessage
if *join {
msg = &pim.JoinPruneMessage{
UpstreamNeighborAddress: net.ParseIP(*upstreamNeighbor).To4(),
NumGroups: 1,
Reserved: 0,
Holdtime: uint16(*holdtime),
Groups: []pim.Group{
{
AddressFamily: 1,
NumJoinedSources: 1,
NumPrunedSources: 0,
MaskLength: 32,
MulticastGroupAddress: net.ParseIP(*group).To4(),
Joins: []pim.SourceAddress{
{
AddressFamily: 1,
Flags: 7,
MaskLength: 32,
EncodingType: 0,
Address: net.ParseIP(*rpAddress).To4(),
},
},
Prunes: []pim.SourceAddress{},
},
Prunes: []pim.SourceAddress{},
},
}}
}
}
if *prune {
msg = &pim.JoinPruneMessage{
UpstreamNeighborAddress: net.ParseIP(*upstreamNeighbor).To4(),
NumGroups: 1,
Reserved: 0,
Holdtime: uint16(*holdtime),
Groups: []pim.Group{
{
AddressFamily: 1,
NumJoinedSources: 0,
NumPrunedSources: 1,
MaskLength: 32,
MulticastGroupAddress: net.ParseIP(*group).To4(),
Joins: []pim.SourceAddress{},
Prunes: []pim.SourceAddress{
{
AddressFamily: 1,
Flags: 7,
MaskLength: 32,
EncodingType: 0,
Address: net.ParseIP(*rpAddress).To4(),
},
},
},
},
}
}

err = join.SerializeTo(buf, opts)
err = msg.SerializeTo(buf, opts)
if err != nil {
log.Fatalf("failed to serialize PIM JoinPrune msg %v", err)
}
Expand Down
4 changes: 2 additions & 2 deletions client/doublezerod/internal/pim/pim.go
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Original file line number Diff line number Diff line change
Expand Up @@ -197,7 +197,7 @@ func decodePimHelloMessage(data []byte, p gopacket.PacketBuilder) error {
return err
}
if addr == nil {
return errors.New("Invalid address")
return errors.New("invalid address")
}

hello.SecondaryAddress = append(hello.SecondaryAddress, addr)
Expand All @@ -218,7 +218,7 @@ func decodePimJoinPruneMessage(data []byte, p gopacket.PacketBuilder) error {
return err
}
if addr == nil {
return errors.New("Invalid address")
return errors.New("invalid address")
}
joinPrune.UpstreamNeighborAddress = addr
data = data[len(addr)+2:]
Expand Down
15 changes: 10 additions & 5 deletions client/doublezerod/internal/pim/server.go
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Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,11 @@ var (
RpAddress = net.IP([]byte{10, 0, 0, 0})
)

const (
joinHoldtime = uint16(120) // ask upstream router to keep join state for 120 seconds
pruneHoldtime = uint16(5) // ask upstream router to flush join state after 5 seconds
)

type RawConner interface {
WriteTo(h *ipv4.Header, b []byte, cm *ipv4.ControlMessage) error
Close() error
Expand Down Expand Up @@ -62,7 +67,7 @@ func (s *PIMServer) Start(conn RawConner, iface string, tunnelAddr net.IP, group
if err != nil {
slog.Error("failed to send PIM hello msg", "error", err)
}
joinPruneMsgBuf, err := constructJoinPruneMessage(tunnelAddr, groups, RpAddress, nil)
joinPruneMsgBuf, err := constructJoinPruneMessage(tunnelAddr, groups, RpAddress, nil, joinHoldtime)
if err != nil {
slog.Error("failed to serialize PIM join msg", "error", err)
}
Expand All @@ -83,7 +88,7 @@ func (s *PIMServer) Start(conn RawConner, iface string, tunnelAddr net.IP, group
if err != nil {
slog.Error("failed to send PIM hello msg", "error", err)
}
joinPruneMsgBuf, err := constructJoinPruneMessage(tunnelAddr, groups, RpAddress, nil)
joinPruneMsgBuf, err := constructJoinPruneMessage(tunnelAddr, groups, RpAddress, nil, joinHoldtime)
if err != nil {
slog.Error("failed to serialize PIM join msg", "error", err)
}
Expand All @@ -92,7 +97,7 @@ func (s *PIMServer) Start(conn RawConner, iface string, tunnelAddr net.IP, group
slog.Error("failed to send PIM join msg", "error", err)
}
case <-s.done:
joinPruneMsgBuf, err := constructJoinPruneMessage(tunnelAddr, groups, nil, RpAddress)
joinPruneMsgBuf, err := constructJoinPruneMessage(tunnelAddr, groups, nil, RpAddress, pruneHoldtime)
if err != nil {
slog.Error("failed to serialize PIM prune msg", "error", err)
}
Expand Down Expand Up @@ -142,7 +147,7 @@ func constructHelloMessage() (gopacket.SerializeBuffer, error) {
}

// TODO: at some point this could require multiple groups with joins/prunes mixed together
func constructJoinPruneMessage(upstreamNeighbor net.IP, multicastGroupAddresses []net.IP, joinSourceAddress net.IP, pruneSourceAddress net.IP) (gopacket.SerializeBuffer, error) {
func constructJoinPruneMessage(upstreamNeighbor net.IP, multicastGroupAddresses []net.IP, joinSourceAddress net.IP, pruneSourceAddress net.IP, holdtime uint16) (gopacket.SerializeBuffer, error) {
numGroups := len(multicastGroupAddresses)
opts := gopacket.SerializeOptions{}
buf := gopacket.NewSerializeBuffer()
Expand All @@ -152,7 +157,7 @@ func constructJoinPruneMessage(upstreamNeighbor net.IP, multicastGroupAddresses
UpstreamNeighborAddress: upstreamNeighbor,
NumGroups: uint8(numGroups),
Reserved: 0,
Holdtime: 210,
Holdtime: holdtime,
Groups: groups,
}

Expand Down
8 changes: 4 additions & 4 deletions client/doublezerod/internal/pim/server_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -121,7 +121,7 @@ func checkJoinMesssage(t *testing.T, b []byte) {
Header: pim.PIMHeader{
Version: 2,
Type: pim.JoinPrune,
Checksum: 0x2deb,
Checksum: 0x2e45,
},
}

Expand All @@ -134,7 +134,7 @@ func checkJoinMesssage(t *testing.T, b []byte) {
UpstreamNeighborAddress: net.IP([]byte{169, 254, 0, 0}),
NumGroups: 1,
Reserved: 0,
Holdtime: 210,
Holdtime: 120,
Groups: []pim.Group{
{
GroupID: 0,
Expand Down Expand Up @@ -172,7 +172,7 @@ func checkPruneMesssage(t *testing.T, b []byte) {
Header: pim.PIMHeader{
Version: 2,
Type: pim.JoinPrune,
Checksum: 0x2deb,
Checksum: 0x2eb8,
},
}

Expand All @@ -185,7 +185,7 @@ func checkPruneMesssage(t *testing.T, b []byte) {
UpstreamNeighborAddress: net.IP([]byte{169, 254, 0, 0}),
NumGroups: 1,
Reserved: 0,
Holdtime: 210,
Holdtime: 5,
Groups: []pim.Group{
{
GroupID: 0,
Expand Down
16 changes: 8 additions & 8 deletions client/doublezerod/internal/runtime/run_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -1386,7 +1386,7 @@ func TestMulticastSubscriber(t *testing.T) {
Header: pim.PIMHeader{
Version: 2,
Type: pim.JoinPrune,
Checksum: 0x2eeb,
Checksum: 0x2f45,
},
}
if diff := cmp.Diff(got, want, cmpopts.IgnoreFields(pim.PIMMessage{}, "BaseLayer")); diff != "" {
Expand All @@ -1398,7 +1398,7 @@ func TestMulticastSubscriber(t *testing.T) {
UpstreamNeighborAddress: net.IP([]byte{169, 254, 0, 0}),
NumGroups: 1,
Reserved: 0,
Holdtime: 210,
Holdtime: 120,
Groups: []pim.Group{{
GroupID: 0,
AddressFamily: 1,
Expand Down Expand Up @@ -1456,7 +1456,7 @@ func TestMulticastSubscriber(t *testing.T) {
Header: pim.PIMHeader{
Version: 2,
Type: pim.JoinPrune,
Checksum: 0x2eeb,
Checksum: 0x2fb8,
},
}
if diff := cmp.Diff(got, want, cmpopts.IgnoreFields(pim.PIMMessage{}, "BaseLayer")); diff != "" {
Expand All @@ -1468,7 +1468,7 @@ func TestMulticastSubscriber(t *testing.T) {
UpstreamNeighborAddress: net.IP([]byte{169, 254, 0, 0}),
NumGroups: 1,
Reserved: 0,
Holdtime: 210,
Holdtime: 5,
Groups: []pim.Group{{
GroupID: 0,
AddressFamily: 1,
Expand Down Expand Up @@ -2205,7 +2205,7 @@ func verifyPimJoinMessageSent(t *testing.T, pimJoinPruneChan chan []byte, upstre
Header: pim.PIMHeader{
Version: 2,
Type: pim.JoinPrune,
Checksum: 0x2deb,
Checksum: 0x2e45,
},
}
if diff := cmp.Diff(got, want, cmpopts.IgnoreFields(pim.PIMMessage{}, "BaseLayer")); diff != "" {
Expand All @@ -2217,7 +2217,7 @@ func verifyPimJoinMessageSent(t *testing.T, pimJoinPruneChan chan []byte, upstre
UpstreamNeighborAddress: upstreamNeighbor,
NumGroups: 1,
Reserved: 0,
Holdtime: 210,
Holdtime: 120,
Groups: []pim.Group{{
GroupID: 0,
AddressFamily: 1,
Expand Down Expand Up @@ -2266,7 +2266,7 @@ func verifyPruneMessageSent(t *testing.T, pimJoinPruneChan chan []byte, upstream
Header: pim.PIMHeader{
Version: 2,
Type: pim.JoinPrune,
Checksum: 0x2deb,
Checksum: 0x2eb8,
},
}
if diff := cmp.Diff(got, want, cmpopts.IgnoreFields(pim.PIMMessage{}, "BaseLayer")); diff != "" {
Expand All @@ -2278,7 +2278,7 @@ func verifyPruneMessageSent(t *testing.T, pimJoinPruneChan chan []byte, upstream
UpstreamNeighborAddress: upstreamNeighbor,
NumGroups: 1,
Reserved: 0,
Holdtime: 210,
Holdtime: 5,
Groups: []pim.Group{{
GroupID: 0,
AddressFamily: 1,
Expand Down