go-ethereum/eth/downloader/skeleton_test.go
rjl493456442 513276864b
eth/downloader: fix flaky test (#29852)
This pull request fixes the flay test TestSkeletonSyncRetrievals. In this test, we first
trigger a sync cycle and wait for it to meet certain expectations. We then inject a new
head and potentially also a new peer, then perform another final sync. The test now
performs the newPeer addition before launching the final sync, and waits a bit for that
peer to get registered. This fixes the logic race that made the test fail sometimes.

Co-authored-by: Guillaume Ballet <3272758+gballet@users.noreply.github.com>
2024-05-27 16:26:55 +02:00

971 lines
35 KiB
Go

// Copyright 2022 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package downloader
import (
"encoding/json"
"errors"
"fmt"
"math/big"
"sync/atomic"
"testing"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/rawdb"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/eth/protocols/eth"
"github.com/ethereum/go-ethereum/ethdb"
"github.com/ethereum/go-ethereum/log"
)
// hookedBackfiller is a tester backfiller with all interface methods mocked and
// hooked so tests can implement only the things they need.
type hookedBackfiller struct {
// suspendHook is an optional hook to be called when the filler is requested
// to be suspended.
suspendHook func() *types.Header
// resumeHook is an optional hook to be called when the filler is requested
// to be resumed.
resumeHook func()
}
// newHookedBackfiller creates a hooked backfiller with all callbacks disabled,
// essentially acting as a noop.
func newHookedBackfiller() backfiller {
return new(hookedBackfiller)
}
// suspend requests the backfiller to abort any running full or snap sync
// based on the skeleton chain as it might be invalid. The backfiller should
// gracefully handle multiple consecutive suspends without a resume, even
// on initial startup.
func (hf *hookedBackfiller) suspend() *types.Header {
if hf.suspendHook != nil {
return hf.suspendHook()
}
return nil // we don't really care about header cleanups for now
}
// resume requests the backfiller to start running fill or snap sync based on
// the skeleton chain as it has successfully been linked. Appending new heads
// to the end of the chain will not result in suspend/resume cycles.
func (hf *hookedBackfiller) resume() {
if hf.resumeHook != nil {
hf.resumeHook()
}
}
// skeletonTestPeer is a mock peer that can only serve header requests from a
// pre-perated header chain (which may be arbitrarily wrong for testing).
//
// Requesting anything else from these peers will hard panic. Note, do *not*
// implement any other methods. We actually want to make sure that the skeleton
// syncer only depends on - and will only ever do so - on header requests.
type skeletonTestPeer struct {
id string // Unique identifier of the mock peer
headers []*types.Header // Headers to serve when requested
serve func(origin uint64) []*types.Header // Hook to allow custom responses
served atomic.Uint64 // Number of headers served by this peer
dropped atomic.Uint64 // Flag whether the peer was dropped (stop responding)
}
// newSkeletonTestPeer creates a new mock peer to test the skeleton sync with.
func newSkeletonTestPeer(id string, headers []*types.Header) *skeletonTestPeer {
return &skeletonTestPeer{
id: id,
headers: headers,
}
}
// newSkeletonTestPeerWithHook creates a new mock peer to test the skeleton sync with,
// and sets an optional serve hook that can return headers for delivery instead
// of the predefined chain. Useful for emulating malicious behavior that would
// otherwise require dedicated peer types.
func newSkeletonTestPeerWithHook(id string, headers []*types.Header, serve func(origin uint64) []*types.Header) *skeletonTestPeer {
return &skeletonTestPeer{
id: id,
headers: headers,
serve: serve,
}
}
// RequestHeadersByNumber constructs a GetBlockHeaders function based on a numbered
// origin; associated with a particular peer in the download tester. The returned
// function can be used to retrieve batches of headers from the particular peer.
func (p *skeletonTestPeer) RequestHeadersByNumber(origin uint64, amount int, skip int, reverse bool, sink chan *eth.Response) (*eth.Request, error) {
// Since skeleton test peer are in-memory mocks, dropping the does not make
// them inaccessible. As such, check a local `dropped` field to see if the
// peer has been dropped and should not respond any more.
if p.dropped.Load() != 0 {
return nil, errors.New("peer already dropped")
}
// Skeleton sync retrieves batches of headers going backward without gaps.
// This ensures we can follow a clean parent progression without any reorg
// hiccups. There is no need for any other type of header retrieval, so do
// panic if there's such a request.
if !reverse || skip != 0 {
// Note, if other clients want to do these kinds of requests, it's their
// problem, it will still work. We just don't want *us* making complicated
// requests without a very strong reason to.
panic(fmt.Sprintf("invalid header retrieval: reverse %v, want true; skip %d, want 0", reverse, skip))
}
// If the skeleton syncer requests the genesis block, panic. Whilst it could
// be considered a valid request, our code specifically should not request it
// ever since we want to link up headers to an existing local chain, which at
// worse will be the genesis.
if int64(origin)-int64(amount) < 0 {
panic(fmt.Sprintf("headers requested before (or at) genesis: origin %d, amount %d", origin, amount))
}
// To make concurrency easier, the skeleton syncer always requests fixed size
// batches of headers. Panic if the peer is requested an amount other than the
// configured batch size (apart from the request leading to the genesis).
if amount > requestHeaders || (amount < requestHeaders && origin > uint64(amount)) {
panic(fmt.Sprintf("non-chunk size header batch requested: requested %d, want %d, origin %d", amount, requestHeaders, origin))
}
// Simple reverse header retrieval. Fill from the peer's chain and return.
// If the tester has a serve hook set, try to use that before falling back
// to the default behavior.
var headers []*types.Header
if p.serve != nil {
headers = p.serve(origin)
}
if headers == nil {
headers = make([]*types.Header, 0, amount)
if len(p.headers) > int(origin) { // Don't serve headers if we're missing the origin
for i := 0; i < amount; i++ {
// Consider nil headers as a form of attack and withhold them. Nil
// cannot be decoded from RLP, so it's not possible to produce an
// attack by sending/receiving those over eth.
header := p.headers[int(origin)-i]
if header == nil {
continue
}
headers = append(headers, header)
}
}
}
p.served.Add(uint64(len(headers)))
hashes := make([]common.Hash, len(headers))
for i, header := range headers {
hashes[i] = header.Hash()
}
// Deliver the headers to the downloader
req := &eth.Request{
Peer: p.id,
}
res := &eth.Response{
Req: req,
Res: (*eth.BlockHeadersRequest)(&headers),
Meta: hashes,
Time: 1,
Done: make(chan error),
}
go func() {
sink <- res
if err := <-res.Done; err != nil {
log.Warn("Skeleton test peer response rejected", "err", err)
p.dropped.Add(1)
}
}()
return req, nil
}
func (p *skeletonTestPeer) Head() (common.Hash, *big.Int) {
panic("skeleton sync must not request the remote head")
}
func (p *skeletonTestPeer) RequestHeadersByHash(common.Hash, int, int, bool, chan *eth.Response) (*eth.Request, error) {
panic("skeleton sync must not request headers by hash")
}
func (p *skeletonTestPeer) RequestBodies([]common.Hash, chan *eth.Response) (*eth.Request, error) {
panic("skeleton sync must not request block bodies")
}
func (p *skeletonTestPeer) RequestReceipts([]common.Hash, chan *eth.Response) (*eth.Request, error) {
panic("skeleton sync must not request receipts")
}
// Tests various sync initializations based on previous leftovers in the database
// and announced heads.
func TestSkeletonSyncInit(t *testing.T) {
// Create a few key headers
var (
genesis = &types.Header{Number: big.NewInt(0)}
block49 = &types.Header{Number: big.NewInt(49)}
block49B = &types.Header{Number: big.NewInt(49), Extra: []byte("B")}
block50 = &types.Header{Number: big.NewInt(50), ParentHash: block49.Hash()}
)
tests := []struct {
headers []*types.Header // Database content (beside the genesis)
oldstate []*subchain // Old sync state with various interrupted subchains
head *types.Header // New head header to announce to reorg to
newstate []*subchain // Expected sync state after the reorg
}{
// Completely empty database with only the genesis set. The sync is expected
// to create a single subchain with the requested head.
{
head: block50,
newstate: []*subchain{{Head: 50, Tail: 50}},
},
// Empty database with only the genesis set with a leftover empty sync
// progress. This is a synthetic case, just for the sake of covering things.
{
oldstate: []*subchain{},
head: block50,
newstate: []*subchain{{Head: 50, Tail: 50}},
},
// A single leftover subchain is present, older than the new head. The
// old subchain should be left as is and a new one appended to the sync
// status.
{
oldstate: []*subchain{{Head: 10, Tail: 5}},
head: block50,
newstate: []*subchain{
{Head: 50, Tail: 50},
{Head: 10, Tail: 5},
},
},
// Multiple leftover subchains are present, older than the new head. The
// old subchains should be left as is and a new one appended to the sync
// status.
{
oldstate: []*subchain{
{Head: 20, Tail: 15},
{Head: 10, Tail: 5},
},
head: block50,
newstate: []*subchain{
{Head: 50, Tail: 50},
{Head: 20, Tail: 15},
{Head: 10, Tail: 5},
},
},
// A single leftover subchain is present, newer than the new head. The
// newer subchain should be deleted and a fresh one created for the head.
{
oldstate: []*subchain{{Head: 65, Tail: 60}},
head: block50,
newstate: []*subchain{{Head: 50, Tail: 50}},
},
// Multiple leftover subchain is present, newer than the new head. The
// newer subchains should be deleted and a fresh one created for the head.
{
oldstate: []*subchain{
{Head: 75, Tail: 70},
{Head: 65, Tail: 60},
},
head: block50,
newstate: []*subchain{{Head: 50, Tail: 50}},
},
// Two leftover subchains are present, one fully older and one fully
// newer than the announced head. The head should delete the newer one,
// keeping the older one.
{
oldstate: []*subchain{
{Head: 65, Tail: 60},
{Head: 10, Tail: 5},
},
head: block50,
newstate: []*subchain{
{Head: 50, Tail: 50},
{Head: 10, Tail: 5},
},
},
// Multiple leftover subchains are present, some fully older and some
// fully newer than the announced head. The head should delete the newer
// ones, keeping the older ones.
{
oldstate: []*subchain{
{Head: 75, Tail: 70},
{Head: 65, Tail: 60},
{Head: 20, Tail: 15},
{Head: 10, Tail: 5},
},
head: block50,
newstate: []*subchain{
{Head: 50, Tail: 50},
{Head: 20, Tail: 15},
{Head: 10, Tail: 5},
},
},
// A single leftover subchain is present and the new head is extending
// it with one more header. We expect the subchain head to be pushed
// forward.
{
headers: []*types.Header{block49},
oldstate: []*subchain{{Head: 49, Tail: 5}},
head: block50,
newstate: []*subchain{{Head: 50, Tail: 5}},
},
// A single leftover subchain is present and although the new head does
// extend it number wise, the hash chain does not link up. We expect a
// new subchain to be created for the dangling head.
{
headers: []*types.Header{block49B},
oldstate: []*subchain{{Head: 49, Tail: 5}},
head: block50,
newstate: []*subchain{
{Head: 50, Tail: 50},
{Head: 49, Tail: 5},
},
},
// A single leftover subchain is present. A new head is announced that
// links into the middle of it, correctly anchoring into an existing
// header. We expect the old subchain to be truncated and extended with
// the new head.
{
headers: []*types.Header{block49},
oldstate: []*subchain{{Head: 100, Tail: 5}},
head: block50,
newstate: []*subchain{{Head: 50, Tail: 5}},
},
// A single leftover subchain is present. A new head is announced that
// links into the middle of it, but does not anchor into an existing
// header. We expect the old subchain to be truncated and a new chain
// be created for the dangling head.
{
headers: []*types.Header{block49B},
oldstate: []*subchain{{Head: 100, Tail: 5}},
head: block50,
newstate: []*subchain{
{Head: 50, Tail: 50},
{Head: 49, Tail: 5},
},
},
}
for i, tt := range tests {
// Create a fresh database and initialize it with the starting state
db := rawdb.NewMemoryDatabase()
rawdb.WriteHeader(db, genesis)
for _, header := range tt.headers {
rawdb.WriteSkeletonHeader(db, header)
}
if tt.oldstate != nil {
blob, _ := json.Marshal(&skeletonProgress{Subchains: tt.oldstate})
rawdb.WriteSkeletonSyncStatus(db, blob)
}
// Create a skeleton sync and run a cycle
wait := make(chan struct{})
skeleton := newSkeleton(db, newPeerSet(), nil, newHookedBackfiller())
skeleton.syncStarting = func() { close(wait) }
skeleton.Sync(tt.head, nil, true)
<-wait
skeleton.Terminate()
// Ensure the correct resulting sync status
expect := skeletonExpect{state: tt.newstate}
if err := checkSkeletonProgress(db, false, nil, expect); err != nil {
t.Errorf("test %d: %v", i, err)
}
}
}
// Tests that a running skeleton sync can be extended with properly linked up
// headers but not with side chains.
func TestSkeletonSyncExtend(t *testing.T) {
// Create a few key headers
var (
genesis = &types.Header{Number: big.NewInt(0)}
block49 = &types.Header{Number: big.NewInt(49)}
block49B = &types.Header{Number: big.NewInt(49), Extra: []byte("B")}
block50 = &types.Header{Number: big.NewInt(50), ParentHash: block49.Hash()}
block51 = &types.Header{Number: big.NewInt(51), ParentHash: block50.Hash()}
)
tests := []struct {
head *types.Header // New head header to announce to reorg to
extend *types.Header // New head header to announce to extend with
newstate []*subchain // Expected sync state after the reorg
err error // Whether extension succeeds or not
}{
// Initialize a sync and try to extend it with a subsequent block.
{
head: block49,
extend: block50,
newstate: []*subchain{
{Head: 50, Tail: 49},
},
},
// Initialize a sync and try to extend it with the existing head block.
{
head: block49,
extend: block49,
newstate: []*subchain{
{Head: 49, Tail: 49},
},
},
// Initialize a sync and try to extend it with a sibling block.
{
head: block49,
extend: block49B,
newstate: []*subchain{
{Head: 49, Tail: 49},
},
err: errChainReorged,
},
// Initialize a sync and try to extend it with a number-wise sequential
// header, but a hash wise non-linking one.
{
head: block49B,
extend: block50,
newstate: []*subchain{
{Head: 49, Tail: 49},
},
err: errChainForked,
},
// Initialize a sync and try to extend it with a non-linking future block.
{
head: block49,
extend: block51,
newstate: []*subchain{
{Head: 49, Tail: 49},
},
err: errChainGapped,
},
// Initialize a sync and try to extend it with a past canonical block.
{
head: block50,
extend: block49,
newstate: []*subchain{
{Head: 50, Tail: 50},
},
err: errChainReorged,
},
// Initialize a sync and try to extend it with a past sidechain block.
{
head: block50,
extend: block49B,
newstate: []*subchain{
{Head: 50, Tail: 50},
},
err: errChainReorged,
},
}
for i, tt := range tests {
// Create a fresh database and initialize it with the starting state
db := rawdb.NewMemoryDatabase()
rawdb.WriteHeader(db, genesis)
// Create a skeleton sync and run a cycle
wait := make(chan struct{})
skeleton := newSkeleton(db, newPeerSet(), nil, newHookedBackfiller())
skeleton.syncStarting = func() { close(wait) }
skeleton.Sync(tt.head, nil, true)
<-wait
if err := skeleton.Sync(tt.extend, nil, false); !errors.Is(err, tt.err) {
t.Errorf("test %d: extension failure mismatch: have %v, want %v", i, err, tt.err)
}
skeleton.Terminate()
// Ensure the correct resulting sync status
expect := skeletonExpect{state: tt.newstate}
if err := checkSkeletonProgress(db, false, nil, expect); err != nil {
t.Errorf("test %d: %v", i, err)
}
}
}
type skeletonExpect struct {
state []*subchain // Expected sync state after the post-init event
serve uint64 // Expected number of header retrievals after initial cycle
drop uint64 // Expected number of peers dropped after initial cycle
}
type skeletonTest struct {
fill bool // Whether to run a real backfiller in this test case
unpredictable bool // Whether to ignore drops/serves due to uncertain packet assignments
head *types.Header // New head header to announce to reorg to
peers []*skeletonTestPeer // Initial peer set to start the sync with
mid skeletonExpect
newHead *types.Header // New header to anoint on top of the old one
newPeer *skeletonTestPeer // New peer to join the skeleton syncer
end skeletonExpect
}
// Tests that the skeleton sync correctly retrieves headers from one or more
// peers without duplicates or other strange side effects.
func TestSkeletonSyncRetrievals(t *testing.T) {
//log.SetDefault(log.NewLogger(log.NewGlogHandler(log.NewTerminalHandler(os.Stderr, false))))
// Since skeleton headers don't need to be meaningful, beyond a parent hash
// progression, create a long fake chain to test with.
chain := []*types.Header{{Number: big.NewInt(0)}}
for i := 1; i < 10000; i++ {
chain = append(chain, &types.Header{
ParentHash: chain[i-1].Hash(),
Number: big.NewInt(int64(i)),
})
}
// Some tests require a forking side chain to trigger cornercases.
var sidechain []*types.Header
for i := 0; i < len(chain)/2; i++ { // Fork at block #5000
sidechain = append(sidechain, chain[i])
}
for i := len(chain) / 2; i < len(chain); i++ {
sidechain = append(sidechain, &types.Header{
ParentHash: sidechain[i-1].Hash(),
Number: big.NewInt(int64(i)),
Extra: []byte("B"), // force a different hash
})
}
tests := []skeletonTest{
// Completely empty database with only the genesis set. The sync is expected
// to create a single subchain with the requested head. No peers however, so
// the sync should be stuck without any progression.
//
// When a new peer is added, it should detect the join and fill the headers
// to the genesis block.
{
head: chain[len(chain)-1],
mid: skeletonExpect{
state: []*subchain{{Head: uint64(len(chain) - 1), Tail: uint64(len(chain) - 1)}},
},
newPeer: newSkeletonTestPeer("test-peer", chain),
end: skeletonExpect{
state: []*subchain{{Head: uint64(len(chain) - 1), Tail: 1}},
serve: uint64(len(chain) - 2), // len - head - genesis
},
},
// Completely empty database with only the genesis set. The sync is expected
// to create a single subchain with the requested head. With one valid peer,
// the sync is expected to complete already in the initial round.
//
// Adding a second peer should not have any effect.
{
head: chain[len(chain)-1],
peers: []*skeletonTestPeer{newSkeletonTestPeer("test-peer-1", chain)},
mid: skeletonExpect{
state: []*subchain{{Head: uint64(len(chain) - 1), Tail: 1}},
serve: uint64(len(chain) - 2), // len - head - genesis
},
newPeer: newSkeletonTestPeer("test-peer-2", chain),
end: skeletonExpect{
state: []*subchain{{Head: uint64(len(chain) - 1), Tail: 1}},
serve: uint64(len(chain) - 2), // len - head - genesis
},
},
// Completely empty database with only the genesis set. The sync is expected
// to create a single subchain with the requested head. With many valid peers,
// the sync is expected to complete already in the initial round.
//
// Adding a new peer should not have any effect.
{
head: chain[len(chain)-1],
peers: []*skeletonTestPeer{
newSkeletonTestPeer("test-peer-1", chain),
newSkeletonTestPeer("test-peer-2", chain),
newSkeletonTestPeer("test-peer-3", chain),
},
mid: skeletonExpect{
state: []*subchain{{Head: uint64(len(chain) - 1), Tail: 1}},
serve: uint64(len(chain) - 2), // len - head - genesis
},
newPeer: newSkeletonTestPeer("test-peer-4", chain),
end: skeletonExpect{
state: []*subchain{{Head: uint64(len(chain) - 1), Tail: 1}},
serve: uint64(len(chain) - 2), // len - head - genesis
},
},
// This test checks if a peer tries to withhold a header - *on* the sync
// boundary - instead of sending the requested amount. The malicious short
// package should not be accepted.
//
// Joining with a new peer should however unblock the sync.
{
head: chain[requestHeaders+100],
peers: []*skeletonTestPeer{
newSkeletonTestPeer("header-skipper", append(append(append([]*types.Header{}, chain[:99]...), nil), chain[100:]...)),
},
mid: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 100}},
serve: requestHeaders + 101 - 3, // len - head - genesis - missing
drop: 1, // penalize shortened header deliveries
},
newPeer: newSkeletonTestPeer("good-peer", chain),
end: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 1}},
serve: (requestHeaders + 101 - 3) + (100 - 1), // midserve + lenrest - genesis
drop: 1, // no new drops
},
},
// This test checks if a peer tries to withhold a header - *off* the sync
// boundary - instead of sending the requested amount. The malicious short
// package should not be accepted.
//
// Joining with a new peer should however unblock the sync.
{
head: chain[requestHeaders+100],
peers: []*skeletonTestPeer{
newSkeletonTestPeer("header-skipper", append(append(append([]*types.Header{}, chain[:50]...), nil), chain[51:]...)),
},
mid: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 100}},
serve: requestHeaders + 101 - 3, // len - head - genesis - missing
drop: 1, // penalize shortened header deliveries
},
newPeer: newSkeletonTestPeer("good-peer", chain),
end: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 1}},
serve: (requestHeaders + 101 - 3) + (100 - 1), // midserve + lenrest - genesis
drop: 1, // no new drops
},
},
// This test checks if a peer tries to duplicate a header - *on* the sync
// boundary - instead of sending the correct sequence. The malicious duped
// package should not be accepted.
//
// Joining with a new peer should however unblock the sync.
{
head: chain[requestHeaders+100], // We want to force the 100th header to be a request boundary
peers: []*skeletonTestPeer{
newSkeletonTestPeer("header-duper", append(append(append([]*types.Header{}, chain[:99]...), chain[98]), chain[100:]...)),
},
mid: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 100}},
serve: requestHeaders + 101 - 2, // len - head - genesis
drop: 1, // penalize invalid header sequences
},
newPeer: newSkeletonTestPeer("good-peer", chain),
end: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 1}},
serve: (requestHeaders + 101 - 2) + (100 - 1), // midserve + lenrest - genesis
drop: 1, // no new drops
},
},
// This test checks if a peer tries to duplicate a header - *off* the sync
// boundary - instead of sending the correct sequence. The malicious duped
// package should not be accepted.
//
// Joining with a new peer should however unblock the sync.
{
head: chain[requestHeaders+100], // We want to force the 100th header to be a request boundary
peers: []*skeletonTestPeer{
newSkeletonTestPeer("header-duper", append(append(append([]*types.Header{}, chain[:50]...), chain[49]), chain[51:]...)),
},
mid: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 100}},
serve: requestHeaders + 101 - 2, // len - head - genesis
drop: 1, // penalize invalid header sequences
},
newPeer: newSkeletonTestPeer("good-peer", chain),
end: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 1}},
serve: (requestHeaders + 101 - 2) + (100 - 1), // midserve + lenrest - genesis
drop: 1, // no new drops
},
},
// This test checks if a peer tries to inject a different header - *on*
// the sync boundary - instead of sending the correct sequence. The bad
// package should not be accepted.
//
// Joining with a new peer should however unblock the sync.
{
head: chain[requestHeaders+100], // We want to force the 100th header to be a request boundary
peers: []*skeletonTestPeer{
newSkeletonTestPeer("header-changer",
append(
append(
append([]*types.Header{}, chain[:99]...),
&types.Header{
ParentHash: chain[98].Hash(),
Number: big.NewInt(int64(99)),
GasLimit: 1,
},
), chain[100:]...,
),
),
},
mid: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 100}},
serve: requestHeaders + 101 - 2, // len - head - genesis
drop: 1, // different set of headers, drop // TODO(karalabe): maybe just diff sync?
},
newPeer: newSkeletonTestPeer("good-peer", chain),
end: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 1}},
serve: (requestHeaders + 101 - 2) + (100 - 1), // midserve + lenrest - genesis
drop: 1, // no new drops
},
},
// This test checks if a peer tries to inject a different header - *off*
// the sync boundary - instead of sending the correct sequence. The bad
// package should not be accepted.
//
// Joining with a new peer should however unblock the sync.
{
head: chain[requestHeaders+100], // We want to force the 100th header to be a request boundary
peers: []*skeletonTestPeer{
newSkeletonTestPeer("header-changer",
append(
append(
append([]*types.Header{}, chain[:50]...),
&types.Header{
ParentHash: chain[49].Hash(),
Number: big.NewInt(int64(50)),
GasLimit: 1,
},
), chain[51:]...,
),
),
},
mid: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 100}},
serve: requestHeaders + 101 - 2, // len - head - genesis
drop: 1, // different set of headers, drop
},
newPeer: newSkeletonTestPeer("good-peer", chain),
end: skeletonExpect{
state: []*subchain{{Head: requestHeaders + 100, Tail: 1}},
serve: (requestHeaders + 101 - 2) + (100 - 1), // midserve + lenrest - genesis
drop: 1, // no new drops
},
},
// This test reproduces a bug caught during review (kudos to @holiman)
// where a subchain is merged with a previously interrupted one, causing
// pending data in the scratch space to become "invalid" (since we jump
// ahead during subchain merge). In that case it is expected to ignore
// the queued up data instead of trying to process on top of a shifted
// task set.
//
// The test is a bit convoluted since it needs to trigger a concurrency
// issue. First we sync up an initial chain of 2x512 items. Then announce
// 2x512+2 as head and delay delivering the head batch to fill the scratch
// space first. The delivery head should merge with the previous download
// and the scratch space must not be consumed further.
{
head: chain[2*requestHeaders],
peers: []*skeletonTestPeer{
newSkeletonTestPeerWithHook("peer-1", chain, func(origin uint64) []*types.Header {
if origin == chain[2*requestHeaders+1].Number.Uint64() {
time.Sleep(100 * time.Millisecond)
}
return nil // Fallback to default behavior, just delayed
}),
newSkeletonTestPeerWithHook("peer-2", chain, func(origin uint64) []*types.Header {
if origin == chain[2*requestHeaders+1].Number.Uint64() {
time.Sleep(100 * time.Millisecond)
}
return nil // Fallback to default behavior, just delayed
}),
},
mid: skeletonExpect{
state: []*subchain{{Head: 2 * requestHeaders, Tail: 1}},
serve: 2*requestHeaders - 1, // len - head - genesis
},
newHead: chain[2*requestHeaders+2],
end: skeletonExpect{
state: []*subchain{{Head: 2*requestHeaders + 2, Tail: 1}},
serve: 4 * requestHeaders,
},
},
// This test reproduces a bug caught by (@rjl493456442) where a skeleton
// header goes missing, causing the sync to get stuck and/or panic.
//
// The setup requires a previously successfully synced chain up to a block
// height N. That results is a single skeleton header (block N) and a single
// subchain (head N, Tail N) being stored on disk.
//
// The following step requires a new sync cycle to a new side chain of a
// height higher than N, and an ancestor lower than N (e.g. N-2, N+2).
// In this scenario, when processing a batch of headers, a link point of
// N-2 will be found, meaning that N-1 and N have been overwritten.
//
// The link event triggers an early exit, noticing that the previous sub-
// chain is a leftover and deletes it (with it's skeleton header N). But
// since skeleton header N has been overwritten to the new side chain, we
// end up losing it and creating a gap.
{
fill: true,
unpredictable: true, // We have good and bad peer too, bad may be dropped, test too short for certainty
head: chain[len(chain)/2+1], // Sync up until the sidechain common ancestor + 2
peers: []*skeletonTestPeer{newSkeletonTestPeer("test-peer-oldchain", chain)},
mid: skeletonExpect{
state: []*subchain{{Head: uint64(len(chain)/2 + 1), Tail: 1}},
},
newHead: sidechain[len(sidechain)/2+3], // Sync up until the sidechain common ancestor + 4
newPeer: newSkeletonTestPeer("test-peer-newchain", sidechain),
end: skeletonExpect{
state: []*subchain{{Head: uint64(len(sidechain)/2 + 3), Tail: uint64(len(chain) / 2)}},
},
},
}
for i, tt := range tests {
// Create a fresh database and initialize it with the starting state
db := rawdb.NewMemoryDatabase()
rawdb.WriteBlock(db, types.NewBlockWithHeader(chain[0]))
rawdb.WriteReceipts(db, chain[0].Hash(), chain[0].Number.Uint64(), types.Receipts{})
// Create a peer set to feed headers through
peerset := newPeerSet()
for _, peer := range tt.peers {
peerset.Register(newPeerConnection(peer.id, eth.ETH68, peer, log.New("id", peer.id)))
}
// Create a peer dropper to track malicious peers
dropped := make(map[string]int)
drop := func(peer string) {
if p := peerset.Peer(peer); p != nil {
p.peer.(*skeletonTestPeer).dropped.Add(1)
}
peerset.Unregister(peer)
dropped[peer]++
}
// Create a backfiller if we need to run more advanced tests
filler := newHookedBackfiller()
if tt.fill {
var filled *types.Header
filler = &hookedBackfiller{
resumeHook: func() {
var progress skeletonProgress
json.Unmarshal(rawdb.ReadSkeletonSyncStatus(db), &progress)
for progress.Subchains[0].Tail < progress.Subchains[0].Head {
header := rawdb.ReadSkeletonHeader(db, progress.Subchains[0].Tail)
rawdb.WriteBlock(db, types.NewBlockWithHeader(header))
rawdb.WriteReceipts(db, header.Hash(), header.Number.Uint64(), types.Receipts{})
rawdb.DeleteSkeletonHeader(db, header.Number.Uint64())
progress.Subchains[0].Tail++
progress.Subchains[0].Next = header.Hash()
}
filled = rawdb.ReadSkeletonHeader(db, progress.Subchains[0].Tail)
rawdb.WriteBlock(db, types.NewBlockWithHeader(filled))
rawdb.WriteReceipts(db, filled.Hash(), filled.Number.Uint64(), types.Receipts{})
},
suspendHook: func() *types.Header {
prev := filled
filled = nil
return prev
},
}
}
// Create a skeleton sync and run a cycle
skeleton := newSkeleton(db, peerset, drop, filler)
skeleton.Sync(tt.head, nil, true)
// Wait a bit (bleah) for the initial sync loop to go to idle. This might
// be either a finish or a never-start hence why there's no event to hook.
waitStart := time.Now()
for waitTime := 20 * time.Millisecond; time.Since(waitStart) < 2*time.Second; waitTime = waitTime * 2 {
time.Sleep(waitTime)
if err := checkSkeletonProgress(db, tt.unpredictable, tt.peers, tt.mid); err == nil {
break
}
}
if err := checkSkeletonProgress(db, tt.unpredictable, tt.peers, tt.mid); err != nil {
t.Errorf("test %d, mid: %v", i, err)
continue
}
// Apply the post-init events if there's any
endpeers := tt.peers
if tt.newPeer != nil {
if err := peerset.Register(newPeerConnection(tt.newPeer.id, eth.ETH68, tt.newPeer, log.New("id", tt.newPeer.id))); err != nil {
t.Errorf("test %d: failed to register new peer: %v", i, err)
}
time.Sleep(time.Millisecond * 50) // given time for peer registration
endpeers = append(tt.peers, tt.newPeer)
}
if tt.newHead != nil {
skeleton.Sync(tt.newHead, nil, true)
}
// Wait a bit (bleah) for the second sync loop to go to idle. This might
// be either a finish or a never-start hence why there's no event to hook.
waitStart = time.Now()
for waitTime := 20 * time.Millisecond; time.Since(waitStart) < 2*time.Second; waitTime = waitTime * 2 {
time.Sleep(waitTime)
if err := checkSkeletonProgress(db, tt.unpredictable, endpeers, tt.end); err == nil {
break
}
}
if err := checkSkeletonProgress(db, tt.unpredictable, endpeers, tt.end); err != nil {
t.Errorf("test %d, end: %v", i, err)
continue
}
// Check that the peers served no more headers than we actually needed
// Clean up any leftover skeleton sync resources
skeleton.Terminate()
}
}
func checkSkeletonProgress(db ethdb.KeyValueReader, unpredictable bool, peers []*skeletonTestPeer, expected skeletonExpect) error {
var progress skeletonProgress
// Check the post-init end state if it matches the required results
json.Unmarshal(rawdb.ReadSkeletonSyncStatus(db), &progress)
if len(progress.Subchains) != len(expected.state) {
return fmt.Errorf("subchain count mismatch: have %d, want %d", len(progress.Subchains), len(expected.state))
}
for j := 0; j < len(progress.Subchains); j++ {
if progress.Subchains[j].Head != expected.state[j].Head {
return fmt.Errorf("subchain %d head mismatch: have %d, want %d", j, progress.Subchains[j].Head, expected.state[j].Head)
}
if progress.Subchains[j].Tail != expected.state[j].Tail {
return fmt.Errorf("subchain %d tail mismatch: have %d, want %d", j, progress.Subchains[j].Tail, expected.state[j].Tail)
}
}
if !unpredictable {
var served uint64
for _, peer := range peers {
served += peer.served.Load()
}
if served != expected.serve {
return fmt.Errorf("served headers mismatch: have %d, want %d", served, expected.serve)
}
var drops uint64
for _, peer := range peers {
drops += peer.dropped.Load()
}
if drops != expected.drop {
return fmt.Errorf("dropped peers mismatch: have %d, want %d", drops, expected.drop)
}
}
return nil
}