Restarted test node @ +/- few seconds Mon Mar  2 13:06:24 CDT 2020

Starting up at max height... 619875

LoadBlockIndex(): hashBestChain=00000000000000000005c533584904108f0ec0485fc4e5a6520ce519ad191d70  height=619875

Complete.

Ready, has 15 connections.

(TRB using -maxsendbuffer=100000 )

--------------------------------------------------------------------------

Code changes:  

Patched TRB.  Want to capture pmap output before, during, and after
wedge as well.  Idea is here to show that one can still utilize the -maxsendbuffer to
override the 10Mb default limit to an abitrary larger limit of 100Mb.


diff -uNr a/bitcoin/src/main.cpp b/bitcoin/src/main.cpp
--- a/bitcoin/src/main.cpp 1f0735d2cee2f9ca2a177aead4ecc7a1371d59c4375aedb172ee99c28b02fa28e664decec9580a510bfca4738d85e377fb74396fe4979b75adbe1a3ec92b01c9
+++ b/bitcoin/src/main.cpp 1badf11c795508db8daa9b4bc5b3e525633669cd4010bbd3f85ada5acc89627d92ddb51faa10d7b28ccaf269d4376c6ff0d55e53501e3a19d8d654eaa70a85d9
@@ -1877,6 +1877,8 @@
             return error("message getdata size() = %d", vInv.size());
         }
 
+        // Counter of bytes sent in response to this 'getdata' command
+        unsigned int sentBytes = 0;
         BOOST_FOREACH(const CInv& inv, vInv)
         {
             if (fShutdown)
@@ -1891,6 +1893,15 @@
                 {
                     CBlock block;
                     block.ReadFromDisk((*mi).second);
+
+                    // Add block's size to sentBytes, and determine if reached limit
+                    sentBytes += block.GetSerializeSize(SER_NETWORK);
+                    if (sentBytes >= SendBufferSize())
+                    {
+                        printf("getdata (block) may not transmit %u bytes\n", sentBytes);
+                        pfrom->Misbehaving(20);
+                        break;
+                    }
                     pfrom->PushMessage("block", block);
 
                     // Trigger them to send a getblocks request for the next batch of inventory
@@ -1913,7 +1924,16 @@
                 {
                     map<CInv, CDataStream>::iterator mi = mapRelay.find(inv);
                     if (mi != mapRelay.end())
+                    {
+                        //nBytes += ((*mi).second).GetSerializeSize(SER_NETWORK);
+                        //if (nBytes >= SendBufferSize())
+                        //{
+                        //    printf("getdata stopping at %u bytes\n", nBytes);
+                        //    pfrom->Misbehaving(100);
+                        //    break;
+                        //}
                         pfrom->PushMessage(inv.GetCommand(), (*mi).second);
+                    }
                 }
             }
             else

 

--------------------------------------------------------------------------

Test 10:  Send 49999 'getdata for block' commands to the node, see how it reacts and if
it recovers.  Host, Port, File = 127.0.0.1, 8333, snap_49999.txt 

Collect pmap before, during, and after.

mod6@localhost ~ $ ./wedger.py 127.0.0.1 8333 snap_49999.txt 
<INCOMING MESSAGE: 'version', 115 bytes>
Alive: V=99999 (/therealbitcoin.org:0.9.99.99/) Jumpers=0x1 (TRB-Compat.) Return Addr=1.2.3.4:8333 Blocks=619875
<INCOMING MESSAGE: 'verack', 0 bytes>
Sending 1799991-byte message packet...
Now listening for replies (Ctl-C to quit...)
<INCOMING MESSAGE: 'getblocks', 1029 bytes>
<INCOMING MESSAGE: 'block', 978262 bytes>
<INCOMING MESSAGE: 'block', 974661 bytes>
Violated BTC Protocol: Invalid payload length!


Found in debug.log:
getdata (block) may not transmit 100115145 bytes

Working as expected.

Did not wedge.  Responding to RPC commands normally.