net: fix a few races. Credit @TheBlueMatt

These are (afaik) all long-standing races or concurrent accesses. Going
forward, we can clean these up so that they're not all individual atomic
accesses.

- Reintroduce cs_vRecv to guard receive-specific vars
- Lock vRecv/vSend for CNodeStats
- Make some vars atomic.
- Only set the connection time in CNode's constructor so that it doesn't change

1 files changed, 10 insertions, 9 deletions

diff --git a/src/net.h b/src/net.h
index e5a19e0f43..89501c764e 100644
--- a/src/net.h
+++ b/src/net.h
@@ -573,6 +573,7 @@ public:
     std::deque<std::vector<unsigned char>> vSendMsg;
     CCriticalSection cs_vSend;
     CCriticalSection cs_hSocket;
+    CCriticalSection cs_vRecv;
 
     CCriticalSection cs_vProcessMsg;
     std::list<CNetMessage> vProcessMsg;
@@ -584,10 +585,10 @@ public:
     uint64_t nRecvBytes;
     std::atomic<int> nRecvVersion;
 
-    int64_t nLastSend;
-    int64_t nLastRecv;
+    std::atomic<int64_t> nLastSend;
+    std::atomic<int64_t> nLastRecv;
     int64_t nTimeConnected;
-    int64_t nTimeOffset;
+    std::atomic<int64_t> nTimeOffset;
     const CAddress addr;
     std::string addrName;
     CService addrLocal;
@@ -614,7 +615,7 @@ public:
     CSemaphoreGrant grantOutbound;
     CCriticalSection cs_filter;
     CBloomFilter* pfilter;
-    int nRefCount;
+    std::atomic<int> nRefCount;
     const NodeId id;
 
     const uint64_t nKeyedNetGroup;
@@ -665,15 +666,15 @@ public:
 
     // Ping time measurement:
     // The pong reply we're expecting, or 0 if no pong expected.
-    uint64_t nPingNonceSent;
+    std::atomic<uint64_t> nPingNonceSent;
     // Time (in usec) the last ping was sent, or 0 if no ping was ever sent.
-    int64_t nPingUsecStart;
+    std::atomic<int64_t> nPingUsecStart;
     // Last measured round-trip time.
-    int64_t nPingUsecTime;
+    std::atomic<int64_t> nPingUsecTime;
     // Best measured round-trip time.
-    int64_t nMinPingUsecTime;
+    std::atomic<int64_t> nMinPingUsecTime;
     // Whether a ping is requested.
-    bool fPingQueued;
+    std::atomic<bool> fPingQueued;
     // Minimum fee rate with which to filter inv's to this node
     CAmount minFeeFilter;
     CCriticalSection cs_feeFilter;