diff options
Diffstat (limited to 'p2p/discover')
| -rw-r--r-- | p2p/discover/udp.go | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/p2p/discover/udp.go b/p2p/discover/udp.go index df9a3065f..e386af363 100644 --- a/p2p/discover/udp.go +++ b/p2p/discover/udp.go @@ -54,6 +54,11 @@ const ( ntpFailureThreshold = 32 // Continuous timeouts after which to check NTP ntpWarningCooldown = 10 * time.Minute // Minimum amount of time to pass before repeating NTP warning driftThreshold = 10 * time.Second // Allowed clock drift before warning user + + // Discovery packets are defined to be no larger than 1280 bytes. + // Packets larger than this size will be cut at the end and treated + // as invalid because their hash won't match. + maxPacketSize = 1280 ) // RPC packet types @@ -496,7 +501,7 @@ var ( headSpace = make([]byte, headSize) // Neighbors replies are sent across multiple packets to - // stay below the 1280 byte limit. We compute the maximum number + // stay below the packet size limit. We compute the maximum number // of entries by stuffing a packet until it grows too large. maxNeighbors int ) @@ -511,7 +516,7 @@ func init() { // If this ever happens, it will be caught by the unit tests. panic("cannot encode: " + err.Error()) } - if headSize+size+1 >= 1280 { + if headSize+size+1 >= maxPacketSize { maxNeighbors = n break } @@ -562,10 +567,7 @@ func (t *udp) readLoop(unhandled chan<- ReadPacket) { defer close(unhandled) } - // Discovery packets are defined to be no larger than 1280 bytes. - // Packets larger than this size will be cut at the end and treated - // as invalid because their hash won't match. - buf := make([]byte, 1280) + buf := make([]byte, maxPacketSize) for { nbytes, from, err := t.conn.ReadFromUDP(buf) if netutil.IsTemporaryError(err) { @@ -715,7 +717,7 @@ func (req *findnode) handle(t *udp, from *net.UDPAddr, fromID enode.ID, mac []by t.tab.mutex.Unlock() // Send neighbors in chunks with at most maxNeighbors per packet - // to stay below the 1280 byte limit. + // to stay below the packet size limit. p := neighbors{Expiration: uint64(time.Now().Add(expiration).Unix())} var sent bool for _, n := range closest { |