diff options
| -rw-r--r-- | src/main.cpp | 28 | ||||
| -rw-r--r-- | src/version.h | 3 |
2 files changed, 28 insertions, 3 deletions
diff --git a/src/main.cpp b/src/main.cpp index b9c9db7a62..fbe9232ac0 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -2652,6 +2652,23 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv) else if (strCommand == "ping") { + if (pfrom->nVersion > BIP0031_VERSION) + { + uint64 nonce = 0; + vRecv >> nonce; + // Echo the message back with the nonce. This allows for two useful features: + // + // 1) A remote node can quickly check if the connection is operational + // 2) Remote nodes can measure the latency of the network thread. If this node + // is overloaded it won't respond to pings quickly and the remote node can + // avoid sending us more work, like chain download requests. + // + // The nonce stops the remote getting confused between different pings: without + // it, if the remote node sends a ping once per second and this node takes 5 + // seconds to respond to each, the 5th ping the remote sends would appear to + // return very quickly. + pfrom->PushMessage("pong", nonce); + } } @@ -2814,9 +2831,14 @@ bool SendMessages(CNode* pto, bool fSendTrickle) if (pto->nVersion == 0) return true; - // Keep-alive ping - if (pto->nLastSend && GetTime() - pto->nLastSend > 30 * 60 && pto->vSend.empty()) - pto->PushMessage("ping"); + // Keep-alive ping. We send a nonce of zero because we don't use it anywhere + // right now. + if (pto->nLastSend && GetTime() - pto->nLastSend > 30 * 60 && pto->vSend.empty()) { + if (pto->nVersion > BIP0031_VERSION) + pto->PushMessage("ping", 0); + else + pto->PushMessage("ping"); + } // Resend wallet transactions that haven't gotten in a block yet ResendWalletTransactions(); diff --git a/src/version.h b/src/version.h index c93b28fb7d..e0e216aad4 100644 --- a/src/version.h +++ b/src/version.h @@ -11,4 +11,7 @@ extern const std::string CLIENT_BUILD; extern const std::string CLIENT_DATE; extern const int CLIENT_VERSION; +// BIP 0031, pong message, is enabled for all versions AFTER this one +const int BIP0031_VERSION = 60000; + #endif |