Merge #19731: net, rpc: expose nLastBlockTime/nLastTXTime as last block/last_transaction in getpeerinfo

5da96210fc2fda9fbd79531f42f91262fd7a9257 doc: release note for getpeerinfo last_block/last_transaction (Jon Atack)
cfef5a2c98b9563392a4a258fedb8bdc869c9749 test: rpc_net.py logging and test naming improvements (Jon Atack)
21c57bacda766a4f56ee75a2872f5d0f94e3901e test: getpeerinfo last_block and last_transaction tests (Jon Atack)
8a560a7d57cbd9f473d6a3782893a0e2243c55bd rpc: expose nLastBlockTime/TXTime as getpeerinfo last_block/transaction (Jon Atack)
02fbe3ae0bd91cbab2828cb7aa46f6493c82f026 net: add nLastBlockTime/TXTime to CNodeStats, CNode::copyStats (Jon Atack)

Pull request description:

  This PR adds inbound peer eviction criteria `nLastBlockTime` and `nLastTXTime` to `CNodeStats` and `CNode::copyStats`, which then allows exposing them in the next commit as `last_transaction` and `last_block` Unix Epoch Time fields in RPC `getpeerinfo`.

  This may be useful for writing missing eviction tests. I'd also like to add `lasttx` and `lastblk` columns to the `-netinfo` dashboard as described in https://github.com/bitcoin/bitcoin/pull/19643#issuecomment-671093420.

  Relevant discussion at the p2p irc meeting http://www.erisian.com.au/bitcoin-core-dev/log-2020-08-11.html#l-549:
  ```text
  <jonatack> i was specifically trying to observe and figure out how to test https://github.com/bitcoin/bitcoin/issues/19500
  <jonatack> which made me realise that i didn't know what was going on with my peer conns in enough detail
  <jonatack> i'm running bitcoin locally with nLastBlockTime and nLastTXTime added to getpeerinfo for my peer connections dashboard
  <jonatack> sipa: is there a good reason why that (eviction criteria) data is not exposed through getpeerinfo currently?
  <sipa> jonatack: nope; i suspect just nobody ever added it
  <jonatack> sipa: thanks. will propose.
  ```

  The last commit is optional, but I think it would be good to have logging in `rpc_net.py`.

ACKs for top commit:
  jnewbery:
    Code review ACK 5da96210fc2fda9fbd79531f42f91262fd7a9257
  theStack:
    Code Review ACK 5da96210fc2fda9fbd79531f42f91262fd7a9257
  darosior:
    ACK 5da96210fc2fda9fbd79531f42f91262fd7a9257

Tree-SHA512: 2db164bc979c014837a676e890869a128beb7cf40114853239e7280f57e768bcb43bff6c1ea76a61556212135281863b5290b50ff9d24fce16c5b89b55d4cd70

3 files changed, 8 insertions, 0 deletions

diff --git a/src/net.cpp b/src/net.cpp
index 6c1980735c..883e57bdf0 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -530,6 +530,8 @@ void CNode::copyStats(CNodeStats &stats, const std::vector<bool> &m_asmap)
     }
     X(nLastSend);
     X(nLastRecv);
+    X(nLastTXTime);
+    X(nLastBlockTime);
     X(nTimeConnected);
     X(nTimeOffset);
     stats.addrName = GetAddrName();
diff --git a/src/net.h b/src/net.h
index 7a8abb401d..c72eada3ff 100644
--- a/src/net.h
+++ b/src/net.h
@@ -619,6 +619,8 @@ public:
     bool fRelayTxes;
     int64_t nLastSend;
     int64_t nLastRecv;
+    int64_t nLastTXTime;
+    int64_t nLastBlockTime;
     int64_t nTimeConnected;
     int64_t nTimeOffset;
     std::string addrName;
diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
index 9bd7c15992..e9343b3348 100644
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -100,6 +100,8 @@ static UniValue getpeerinfo(const JSONRPCRequest& request)
                             {RPCResult::Type::BOOL, "relaytxes", "Whether peer has asked us to relay transactions to it"},
                             {RPCResult::Type::NUM_TIME, "lastsend", "The " + UNIX_EPOCH_TIME + " of the last send"},
                             {RPCResult::Type::NUM_TIME, "lastrecv", "The " + UNIX_EPOCH_TIME + " of the last receive"},
+                            {RPCResult::Type::NUM_TIME, "last_transaction", "The " + UNIX_EPOCH_TIME + " of the last valid transaction received from this peer"},
+                            {RPCResult::Type::NUM_TIME, "last_block", "The " + UNIX_EPOCH_TIME + " of the last block received from this peer"},
                             {RPCResult::Type::NUM, "bytessent", "The total bytes sent"},
                             {RPCResult::Type::NUM, "bytesrecv", "The total bytes received"},
                             {RPCResult::Type::NUM_TIME, "conntime", "The " + UNIX_EPOCH_TIME + " of the connection"},
@@ -169,6 +171,8 @@ static UniValue getpeerinfo(const JSONRPCRequest& request)
         obj.pushKV("relaytxes", stats.fRelayTxes);
         obj.pushKV("lastsend", stats.nLastSend);
         obj.pushKV("lastrecv", stats.nLastRecv);
+        obj.pushKV("last_transaction", stats.nLastTXTime);
+        obj.pushKV("last_block", stats.nLastBlockTime);
         obj.pushKV("bytessent", stats.nSendBytes);
         obj.pushKV("bytesrecv", stats.nRecvBytes);
         obj.pushKV("conntime", stats.nTimeConnected);