tailscale/tka/sync_test.go

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// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tka
import (
"bytes"
"strconv"
"testing"
"github.com/google/go-cmp/cmp"
)
func TestSyncOffer(t *testing.T) {
c := newTestchain(t, `
A1 -> A2 -> A3 -> A4 -> A5 -> A6 -> A7 -> A8 -> A9 -> A10
A10 -> A11 -> A12 -> A13 -> A14 -> A15 -> A16 -> A17 -> A18
A18 -> A19 -> A20 -> A21 -> A22 -> A23 -> A24 -> A25
`)
a, err := Open(c.Chonk())
if err != nil {
t.Fatal(err)
}
got, err := a.SyncOffer()
if err != nil {
t.Fatal(err)
}
// A SyncOffer includes a selection of AUMs going backwards in the tree,
// progressively skipping more and more each iteration.
want := SyncOffer{
Head: c.AUMHashes["A25"],
Ancestors: []AUMHash{
c.AUMHashes["A"+strconv.Itoa(25-ancestorsSkipStart)],
c.AUMHashes["A"+strconv.Itoa(25-ancestorsSkipStart<<ancestorsSkipShift)],
c.AUMHashes["A1"],
},
}
if diff := cmp.Diff(want, got); diff != "" {
t.Errorf("SyncOffer diff (-want, +got):\n%s", diff)
}
}
func TestComputeSyncIntersection_FastForward(t *testing.T) {
// Node 1 has: A1 -> A2
// Node 2 has: A1 -> A2 -> A3 -> A4
c := newTestchain(t, `
A1 -> A2 -> A3 -> A4
`)
a1H, a2H := c.AUMHashes["A1"], c.AUMHashes["A2"]
chonk1 := c.ChonkWith("A1", "A2")
n1, err := Open(chonk1)
if err != nil {
t.Fatal(err)
}
offer1, err := n1.SyncOffer()
if err != nil {
t.Fatal(err)
}
chonk2 := c.Chonk() // All AUMs
n2, err := Open(chonk2)
if err != nil {
t.Fatal(err)
}
offer2, err := n2.SyncOffer()
if err != nil {
t.Fatal(err)
}
// Node 1 only knows about the first two nodes, so the head of n2 is
// alien to it.
t.Run("n1", func(t *testing.T) {
got, err := computeSyncIntersection(n1, offer1, offer2)
if err != nil {
t.Fatalf("computeSyncIntersection() failed: %v", err)
}
want := &intersection{
tailIntersection: &a1H,
}
if diff := cmp.Diff(want, got, cmp.AllowUnexported(intersection{})); diff != "" {
t.Errorf("intersection diff (-want, +got):\n%s", diff)
}
})
// Node 2 knows about the full chain, so it can see that the head of n1
// intersects with a subset of its chain (a Head Intersection).
t.Run("n2", func(t *testing.T) {
got, err := computeSyncIntersection(n2, offer2, offer1)
if err != nil {
t.Fatalf("computeSyncIntersection() failed: %v", err)
}
want := &intersection{
headIntersection: &a2H,
}
if diff := cmp.Diff(want, got, cmp.AllowUnexported(intersection{})); diff != "" {
t.Errorf("intersection diff (-want, +got):\n%s", diff)
}
})
}
func TestComputeSyncIntersection_ForkSmallDiff(t *testing.T) {
// The number of nodes in the chain is longer than ancestorSkipStart,
// so that during sync both nodes are able to find a common ancestor
// which was later than A1.
c := newTestchain(t, `
A1 -> A2 -> A3 -> A4 -> A5 -> A6 -> A7 -> A8 -> A9 -> A10
| -> F1
// Make F1 different to A9.
// hashSeed is chosen such that the hash is higher than A9.
F1.hashSeed = 7
`)
// Node 1 has: A1 -> A2 -> A3 -> A4 -> A5 -> A6 -> A7 -> A8 -> F1
// Node 2 has: A1 -> A2 -> A3 -> A4 -> A5 -> A6 -> A7 -> A8 -> A9 -> A10
f1H, a9H := c.AUMHashes["F1"], c.AUMHashes["A9"]
if bytes.Compare(f1H[:], a9H[:]) < 0 {
t.Fatal("failed assert: h(a9) > h(f1H)\nTweak hashSeed till this passes")
}
n1, err := Open(c.ChonkWith("A1", "A2", "A3", "A4", "A5", "A6", "A7", "A8", "F1"))
if err != nil {
t.Fatal(err)
}
offer1, err := n1.SyncOffer()
if err != nil {
t.Fatal(err)
}
if diff := cmp.Diff(SyncOffer{
Head: c.AUMHashes["F1"],
Ancestors: []AUMHash{
c.AUMHashes["A"+strconv.Itoa(9-ancestorsSkipStart)],
c.AUMHashes["A1"],
},
}, offer1); diff != "" {
t.Errorf("offer1 diff (-want, +got):\n%s", diff)
}
n2, err := Open(c.ChonkWith("A1", "A2", "A3", "A4", "A5", "A6", "A7", "A8", "A9", "A10"))
if err != nil {
t.Fatal(err)
}
offer2, err := n2.SyncOffer()
if err != nil {
t.Fatal(err)
}
if diff := cmp.Diff(SyncOffer{
Head: c.AUMHashes["A10"],
Ancestors: []AUMHash{
c.AUMHashes["A"+strconv.Itoa(10-ancestorsSkipStart)],
c.AUMHashes["A1"],
},
}, offer2); diff != "" {
t.Errorf("offer2 diff (-want, +got):\n%s", diff)
}
// Node 1 only knows about the first eight nodes, so the head of n2 is
// alien to it.
t.Run("n1", func(t *testing.T) {
// n2 has 10 nodes, so the first common ancestor should be 10-ancestorsSkipStart
wantIntersection := c.AUMHashes["A"+strconv.Itoa(10-ancestorsSkipStart)]
got, err := computeSyncIntersection(n1, offer1, offer2)
if err != nil {
t.Fatalf("computeSyncIntersection() failed: %v", err)
}
want := &intersection{
tailIntersection: &wantIntersection,
}
if diff := cmp.Diff(want, got, cmp.AllowUnexported(intersection{})); diff != "" {
t.Errorf("intersection diff (-want, +got):\n%s", diff)
}
})
// Node 2 knows about the full chain but doesn't recognize the head.
t.Run("n2", func(t *testing.T) {
// n1 has 9 nodes, so the first common ancestor should be 9-ancestorsSkipStart
wantIntersection := c.AUMHashes["A"+strconv.Itoa(9-ancestorsSkipStart)]
got, err := computeSyncIntersection(n2, offer2, offer1)
if err != nil {
t.Fatalf("computeSyncIntersection() failed: %v", err)
}
want := &intersection{
tailIntersection: &wantIntersection,
}
if diff := cmp.Diff(want, got, cmp.AllowUnexported(intersection{})); diff != "" {
t.Errorf("intersection diff (-want, +got):\n%s", diff)
}
})
}
func TestMissingAUMs_FastForward(t *testing.T) {
// Node 1 has: A1 -> A2
// Node 2 has: A1 -> A2 -> A3 -> A4
c := newTestchain(t, `
A1 -> A2 -> A3 -> A4
A1.hashSeed = 1
A2.hashSeed = 2
A3.hashSeed = 3
A4.hashSeed = 4
`)
chonk1 := c.ChonkWith("A1", "A2")
n1, err := Open(chonk1)
if err != nil {
t.Fatal(err)
}
offer1, err := n1.SyncOffer()
if err != nil {
t.Fatal(err)
}
chonk2 := c.Chonk() // All AUMs
n2, err := Open(chonk2)
if err != nil {
t.Fatal(err)
}
offer2, err := n2.SyncOffer()
if err != nil {
t.Fatal(err)
}
// Node 1 only knows about the first two nodes, so the head of n2 is
// alien to it. As such, it should send history from the newest ancestor,
// A1 (if the chain was longer there would be one in the middle).
t.Run("n1", func(t *testing.T) {
got, err := n1.MissingAUMs(offer2)
if err != nil {
t.Fatalf("MissingAUMs() failed: %v", err)
}
// Both sides have A1, so the only AUM that n2 might not have is
// A2.
want := []AUM{c.AUMs["A2"]}
if diff := cmp.Diff(want, got); diff != "" {
t.Errorf("MissingAUMs diff (-want, +got):\n%s", diff)
}
})
// Node 2 knows about the full chain, so it can see that the head of n1
// intersects with a subset of its chain (a Head Intersection).
t.Run("n2", func(t *testing.T) {
got, err := n2.MissingAUMs(offer1)
if err != nil {
t.Fatalf("MissingAUMs() failed: %v", err)
}
want := []AUM{
c.AUMs["A3"],
c.AUMs["A4"],
}
if diff := cmp.Diff(want, got); diff != "" {
t.Errorf("MissingAUMs diff (-want, +got):\n%s", diff)
}
})
}
func TestMissingAUMs_Fork(t *testing.T) {
// Node 1 has: A1 -> A2 -> A3 -> F1
// Node 2 has: A1 -> A2 -> A3 -> A4
c := newTestchain(t, `
A1 -> A2 -> A3 -> A4
| -> F1
A1.hashSeed = 1
A2.hashSeed = 2
A3.hashSeed = 3
A4.hashSeed = 4
`)
chonk1 := c.ChonkWith("A1", "A2", "A3", "F1")
n1, err := Open(chonk1)
if err != nil {
t.Fatal(err)
}
offer1, err := n1.SyncOffer()
if err != nil {
t.Fatal(err)
}
chonk2 := c.ChonkWith("A1", "A2", "A3", "A4")
n2, err := Open(chonk2)
if err != nil {
t.Fatal(err)
}
offer2, err := n2.SyncOffer()
if err != nil {
t.Fatal(err)
}
t.Run("n1", func(t *testing.T) {
got, err := n1.MissingAUMs(offer2)
if err != nil {
t.Fatalf("MissingAUMs() failed: %v", err)
}
// Both sides have A1, so n1 will send everything it knows from
// there to head.
want := []AUM{
c.AUMs["A2"],
c.AUMs["A3"],
c.AUMs["F1"],
}
if diff := cmp.Diff(want, got); diff != "" {
t.Errorf("MissingAUMs diff (-want, +got):\n%s", diff)
}
})
t.Run("n2", func(t *testing.T) {
got, err := n2.MissingAUMs(offer1)
if err != nil {
t.Fatalf("MissingAUMs() failed: %v", err)
}
// Both sides have A1, so n2 will send everything it knows from
// there to head.
want := []AUM{
c.AUMs["A2"],
c.AUMs["A3"],
c.AUMs["A4"],
}
if diff := cmp.Diff(want, got); diff != "" {
t.Errorf("MissingAUMs diff (-want, +got):\n%s", diff)
}
})
}
func TestSyncSimpleE2E(t *testing.T) {
pub, priv := testingKey25519(t, 1)
key := Key{Kind: Key25519, Public: pub, Votes: 2}
c := newTestchain(t, `
G1 -> L1 -> L2 -> L3
G1.template = genesis
`,
optTemplate("genesis", AUM{MessageKind: AUMCheckpoint, State: &State{
Keys: []Key{key},
DisablementSecrets: [][]byte{disablementKDF([]byte{1, 2, 3})},
}}),
optKey("key", key, priv),
optSignAllUsing("key"))
node, err := Bootstrap(&Mem{}, c.AUMs["G1"])
if err != nil {
t.Fatalf("node Bootstrap() failed: %v", err)
}
control, err := Open(c.Chonk())
if err != nil {
t.Fatalf("control Open() failed: %v", err)
}
// Control knows the full chain, node only knows the genesis. Lets see
// if they can sync.
nodeOffer, err := node.SyncOffer()
if err != nil {
t.Fatal(err)
}
controlAUMs, err := control.MissingAUMs(nodeOffer)
if err != nil {
t.Fatalf("control.MissingAUMs(%v) failed: %v", nodeOffer, err)
}
if err := node.Inform(controlAUMs); err != nil {
t.Fatalf("node.Inform(%v) failed: %v", controlAUMs, err)
}
if cHash, nHash := control.Head(), node.Head(); cHash != nHash {
t.Errorf("node & control are not synced: c=%x, n=%x", cHash, nHash)
}
}