diff options
Diffstat (limited to 'eth/downloader')
| -rw-r--r-- | eth/downloader/downloader.go | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go index b6b9d54f0..c8f710450 100644 --- a/eth/downloader/downloader.go +++ b/eth/downloader/downloader.go @@ -572,11 +572,17 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) { if head > height { head = height } - from := int64(head) - int64(MaxHeaderFetch) + 1 + from := int64(head) - int64(MaxHeaderFetch) if from < 0 { from = 0 } - go p.getAbsHeaders(uint64(from), MaxHeaderFetch, 0, false) + // Span out with 15 block gaps into the future to catch bad head reports + limit := 2 * MaxHeaderFetch / 16 + count := 1 + int((int64(ceil)-from)/16) + if count > limit { + count = limit + } + go p.getAbsHeaders(uint64(from), count, 15, false) // Wait for the remote response to the head fetch number, hash := uint64(0), common.Hash{} @@ -601,12 +607,8 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) { } // Make sure the peer's reply conforms to the request for i := 0; i < len(headers); i++ { - if number := headers[i].Number.Int64(); number != from+int64(i) { - glog.V(logger.Warn).Infof("%v: head header set (item %d) broke chain ordering: requested %d, got %d", p, i, from+int64(i), number) - return 0, errInvalidChain - } - if i > 0 && headers[i-1].Hash() != headers[i].ParentHash { - glog.V(logger.Warn).Infof("%v: head header set (item %d) broke chain ancestry: expected [%x], got [%x]", p, i, headers[i-1].Hash().Bytes()[:4], headers[i].ParentHash[:4]) + if number := headers[i].Number.Int64(); number != from+int64(i)*16 { + glog.V(logger.Warn).Infof("%v: head header set (item %d) broke chain ordering: requested %d, got %d", p, i, from+int64(i)*16, number) return 0, errInvalidChain } } @@ -614,12 +616,18 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) { finished = true for i := len(headers) - 1; i >= 0; i-- { // Skip any headers that underflow/overflow our requested set - if headers[i].Number.Int64() < from || headers[i].Number.Uint64() > head { + if headers[i].Number.Int64() < from || headers[i].Number.Uint64() > ceil { continue } // Otherwise check if we already know the header or not if (d.mode == FullSync && d.hasBlockAndState(headers[i].Hash())) || (d.mode != FullSync && d.hasHeader(headers[i].Hash())) { number, hash = headers[i].Number.Uint64(), headers[i].Hash() + + // If every header is known, even future ones, the peer straight out lied about its head + if number > height && i == limit-1 { + glog.V(logger.Warn).Infof("%v: lied about chain head: reported %d, found above %d", p, height, number) + return 0, errStallingPeer + } break } } |