Merge #14733: P2P: Make peer timeout configurable, speed up very slow test and ensure correct code path tested.

48b37db50 make peertimeout a debug argument, remove error message translation (Zain Iqbal Allarakhia)
8042bbfbf p2p: allow p2ptimeout to be configurable, speed up slow test (Zain Iqbal Allarakhia)

Pull request description:

  **Summary:**

  1. _Primary_: Adds a `debug_only=true` flag for peertimeout, defaults to 60 sec., the current hard-coded setting.
  2. _Secondary_: Drastically speeds up `p2p_timeout.py` test.
  3. _Secondary_: Tests that the correct code path is being tested by adding log assertions to the test.

  **Rationale:**

  - P2P timeout was hard-coded: make it explicitly specified and configurable, instead of a magic number.
  - Addresses #13518; `p2p_timeout.py` takes 4 sec. to run instead of 61 sec.
  - Makes `p2p_timeout.py` more explicit. Previously, we relied on a comment to inform us of the timeout amount being tested. Now it is specified directly in the test via passing in the new arg; `-peertimeout=3`.
  - Opens us up to testing more P2P scenarios; oftentimes slow tests are the reason we don't test.

  **Locally verified changes:**

  _With Proposed Change (4.7 sec.):_
  ```
  $ time ./test/functional/p2p_timeouts.py
  2018-11-19T00:04:19.077000Z TestFramework (INFO): Initializing test directory /tmp/testhja7g2n7
  2018-11-19T00:04:23.479000Z TestFramework (INFO): Stopping nodes
  2018-11-19T00:04:23.683000Z TestFramework (INFO): Cleaning up /tmp/testhja7g2n7 on exit
  2018-11-19T00:04:23.683000Z TestFramework (INFO): Tests successful

  real    0m4.743s
  ```

  _Currently  on master (62.8 sec.):_
  ```
  $ time ./test/functional/p2p_timeouts.py
  2018-11-19T00:06:10.948000Z TestFramework (INFO): Initializing test directory /tmp/test6mo6k21h
  2018-11-19T00:07:13.376000Z TestFramework (INFO): Stopping nodes
  2018-11-19T00:07:13.631000Z TestFramework (INFO): Cleaning up /tmp/test6mo6k21h on exit
  2018-11-19T00:07:13.631000Z TestFramework (INFO): Tests successful

  real    1m2.836s
  ```

  _Error message demonstrated for new argument `-peertimeout`:_
  ```
  $ ./bitcoind -peertimeout=-5
  ...
  Error: peertimeout cannot be configured with a negative value.
  ```

Tree-SHA512: ff7a244ebea54c4059407bf4fb86465714e6a79cef5d2bcaa22cfe831a81761aaf597ba4d5172fc2ec12266f54712216fc41b5d24849e5d9dab39ba6f09e3a2a

src/net.h

@@ -78,6 +78,8 @@ static const uint64_t DEFAULT_MAX_UPLOAD_TARGET = 0;
 static const uint64_t MAX_UPLOAD_TIMEFRAME = 60 * 60 * 24;
 /** Default for blocks only*/
 static const bool DEFAULT_BLOCKSONLY = false;
+/** -peertimeout default */
+static const int64_t DEFAULT_PEER_CONNECT_TIMEOUT = 60;
 
 static const bool DEFAULT_FORCEDNSSEED = false;
 static const size_t DEFAULT_MAXRECEIVEBUFFER = 5 * 1000;
@@ -138,6 +140,7 @@ public:
         unsigned int nReceiveFloodSize = 0;
         uint64_t nMaxOutboundTimeframe = 0;
         uint64_t nMaxOutboundLimit = 0;
+        int64_t m_peer_connect_timeout = DEFAULT_PEER_CONNECT_TIMEOUT;
         std::vector<std::string> vSeedNodes;
         std::vector<CSubNet> vWhitelistedRange;
         std::vector<CService> vBinds, vWhiteBinds;
@@ -158,6 +161,7 @@ public:
         m_msgproc = connOptions.m_msgproc;
         nSendBufferMaxSize = connOptions.nSendBufferMaxSize;
         nReceiveFloodSize = connOptions.nReceiveFloodSize;
+        m_peer_connect_timeout = connOptions.m_peer_connect_timeout;
         {
             LOCK(cs_totalBytesSent);
             nMaxOutboundTimeframe = connOptions.nMaxOutboundTimeframe;
@@ -391,6 +395,9 @@ private:
     uint64_t nMaxOutboundLimit GUARDED_BY(cs_totalBytesSent);
     uint64_t nMaxOutboundTimeframe GUARDED_BY(cs_totalBytesSent);
 
+    // P2P timeout in seconds
+    int64_t m_peer_connect_timeout;
+
     // Whitelisted ranges. Any node connecting from these is automatically
     // whitelisted (as well as those connecting to whitelisted binds).
     std::vector<CSubNet> vWhitelistedRange;