Merge #11456: Replace relevant services logic with a function suite.

15f5d3b17 Switch DNSSeed-needed metric to any-automatic-nodes, not services (Matt Corallo)
5ee88b4bd Clarify docs for requirements/handling of addnode/connect nodes (Matt Corallo)
57edc0b0c Rename fAddnode to a more-descriptive "manual_connection" (Matt Corallo)
44407100f Replace relevant services logic with a function suite. (Matt Corallo)

Pull request description:

  This was mostly written as a way to clean things up so that the NETWORK_LIMITED PR (#10387) can be simplified a ton, but its also a nice standalone cleanup that will also require a bit of review because it tweaks a lot of stuff across net. The new functions are fine in protocol.h right now since they're straight-forward, but after NETWORK_LIMITED will really want to move elsewhere after @theuni moves the nServices-based selection to addrman from connman.

  Adds HasAllRelevantServices and GetRelevantServices, which check
  for NETWORK|WITNESS.

  This changes the following:
   * Removes nRelevantServices from CConnman, disconnecting it a bit
     more from protocol-level logic.
   * Replaces our sometimes-connect-to-!WITNESS-nodes logic with
     simply always requiring WITNESS|NETWORK for outbound non-feeler
     connections (feelers still only require NETWORK).
   * This has the added benefit of removing nServicesExpected from
     CNode - instead letting net_processing's VERSION message
     handling simply check HasAllRelevantServices.
   * This implies we believe WITNESS nodes to continue to be a
     significant majority of nodes on the network, but also because
     we cannot sync properly from !WITNESS nodes, it is strange to
     continue using our valuable outbound slots on them.
   * In order to prevent this change from preventing connection to
     -connect= nodes which have !WITNESS, -connect nodes are now
     given the "addnode" flag. This also allows outbound connections
     to !NODE_NETWORK nodes for -connect nodes (which was already true
     of addnodes).
   * Has the (somewhat unintended) consequence of changing one of the
     eviction metrics from the same
     sometimes-connect-to-!WITNESS-nodes metric to requiring
     HasRelevantServices.

  This should make NODE_NETWORK_LIMITED much simpler to implement.

Tree-SHA512: 90606896c86cc5da14c77843b16674a6a012065e7b583d76d1c47a18215358abefcbab44ff4fab3fadcd39aa9a42d4740c6dc8874a58033bdfc8ad3fb5c649fc

1 files changed, 2 insertions, 7 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 539adc23d5..f63ad7f5d3 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -369,11 +369,11 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-txindex", strprintf(_("Maintain a full transaction index, used by the getrawtransaction rpc call (default: %u)"), DEFAULT_TXINDEX));
 
     strUsage += HelpMessageGroup(_("Connection options:"));
-    strUsage += HelpMessageOpt("-addnode=<ip>", _("Add a node to connect to and attempt to keep the connection open"));
+    strUsage += HelpMessageOpt("-addnode=<ip>", _("Add a node to connect to and attempt to keep the connection open (see the `addnode` RPC command help for more info)"));
     strUsage += HelpMessageOpt("-banscore=<n>", strprintf(_("Threshold for disconnecting misbehaving peers (default: %u)"), DEFAULT_BANSCORE_THRESHOLD));
     strUsage += HelpMessageOpt("-bantime=<n>", strprintf(_("Number of seconds to keep misbehaving peers from reconnecting (default: %u)"), DEFAULT_MISBEHAVING_BANTIME));
     strUsage += HelpMessageOpt("-bind=<addr>", _("Bind to given address and always listen on it. Use [host]:port notation for IPv6"));
-    strUsage += HelpMessageOpt("-connect=<ip>", _("Connect only to the specified node(s); -connect=0 disables automatic connections"));
+    strUsage += HelpMessageOpt("-connect=<ip>", _("Connect only to the specified node(s); -connect=0 disables automatic connections (the rules for this peer are the same as for -addnode)"));
     strUsage += HelpMessageOpt("-discover", _("Discover own IP addresses (default: 1 when listening and no -externalip or -proxy)"));
     strUsage += HelpMessageOpt("-dns", _("Allow DNS lookups for -addnode, -seednode and -connect") + " " + strprintf(_("(default: %u)"), DEFAULT_NAME_LOOKUP));
     strUsage += HelpMessageOpt("-dnsseed", _("Query for peer addresses via DNS lookup, if low on addresses (default: 1 unless -connect used)"));
@@ -815,7 +815,6 @@ void InitLogging()
 
 namespace { // Variables internal to initialization process only
 
-ServiceFlags nRelevantServices = NODE_NETWORK;
 int nMaxConnections;
 int nUserMaxConnections;
 int nFD;
@@ -1604,9 +1603,6 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
         // Note that setting NODE_WITNESS is never required: the only downside from not
         // doing so is that after activation, no upgraded nodes will fetch from you.
         nLocalServices = ServiceFlags(nLocalServices | NODE_WITNESS);
-        // Only care about others providing witness capabilities if there is a softfork
-        // defined.
-        nRelevantServices = ServiceFlags(nRelevantServices | NODE_WITNESS);
     }
 
     // ********************************************************* Step 10: import blocks
@@ -1663,7 +1659,6 @@ bool AppInitMain(boost::thread_group& threadGroup, CScheduler& scheduler)
 
     CConnman::Options connOptions;
     connOptions.nLocalServices = nLocalServices;
-    connOptions.nRelevantServices = nRelevantServices;
     connOptions.nMaxConnections = nMaxConnections;
     connOptions.nMaxOutbound = std::min(MAX_OUTBOUND_CONNECTIONS, connOptions.nMaxConnections);
     connOptions.nMaxAddnode = MAX_ADDNODE_CONNECTIONS;