aboutsummaryrefslogtreecommitdiffstats
path: root/eth/downloader
diff options
context:
space:
mode:
Diffstat (limited to 'eth/downloader')
-rw-r--r--eth/downloader/downloader.go26
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
}
}