From 44407100ff9b478d6131a1c38ee993b50b1830df Mon Sep 17 00:00:00 2001 From: Matt Corallo Date: Wed, 4 Oct 2017 17:59:30 -0400 Subject: Replace relevant services logic with a function suite. 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. --- src/protocol.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'src/protocol.h') diff --git a/src/protocol.h b/src/protocol.h index 67e01d9606..56b59aed3f 100644 --- a/src/protocol.h +++ b/src/protocol.h @@ -277,6 +277,43 @@ enum ServiceFlags : uint64_t { // BIP process. }; +/** + * Gets the set of service flags which are "desirable" for a given peer. + * + * These are the flags which are required for a peer to support for them + * to be "interesting" to us, ie for us to wish to use one of our few + * outbound connection slots for or for us to wish to prioritize keeping + * their connection around. + * + * Relevant service flags may be peer- and state-specific in that the + * version of the peer may determine which flags are required (eg in the + * case of NODE_NETWORK_LIMITED where we seek out NODE_NETWORK peers + * unless they set NODE_NETWORK_LIMITED and we are out of IBD, in which + * case NODE_NETWORK_LIMITED suffices). + * + * Thus, generally, avoid calling with peerServices == NODE_NONE. + */ +static ServiceFlags GetDesirableServiceFlags(ServiceFlags services) { + return ServiceFlags(NODE_NETWORK | NODE_WITNESS); +} + +/** + * A shortcut for (services & GetDesirableServiceFlags(services)) + * == GetDesirableServiceFlags(services), ie determines whether the given + * set of service flags are sufficient for a peer to be "relevant". + */ +static inline bool HasAllDesirableServiceFlags(ServiceFlags services) { + return !(GetDesirableServiceFlags(services) & (~services)); +} + +/** + * Checks if a peer with the given service flags may be capable of having a + * robust address-storage DB. Currently an alias for checking NODE_NETWORK. + */ +static inline bool MayHaveUsefulAddressDB(ServiceFlags services) { + return services & NODE_NETWORK; +} + /** A CService with information about it as peer */ class CAddress : public CService { -- cgit v1.2.3