Create a knob to switch CBFs off.

While having them on by default. We may want to revisit this and
make no CBFs the default.

config.go

@@ -150,6 +150,7 @@ type config struct {
 	BlockPrioritySize    uint32        `long:"blockprioritysize" description:"Size in bytes for high-priority/low-fee transactions when creating a block"`
 	UserAgentComments    []string      `long:"uacomment" description:"Comment to add to the user agent -- See BIP 14 for more information."`
 	NoPeerBloomFilters   bool          `long:"nopeerbloomfilters" description:"Disable bloom filtering support"`
+	NoCBFilters          bool          `long:"nocbfilters" description:"Disable committed bloom filtering (CBF) support"`
 	SigCacheMaxSize      uint          `long:"sigcachemaxsize" description:"The maximum number of entries in the signature verification cache"`
 	BlocksOnly           bool          `long:"blocksonly" description:"Do not accept transactions from remote peers."`
 	TxIndex              bool          `long:"txindex" description:"Maintain a full hash-based transaction index which makes all transactions available via the getrawtransaction RPC"`

doc.go

@@ -112,6 +112,7 @@ Application Options:
       --blockprioritysize=  Size in bytes for high-priority/low-fee transactions
                             when creating a block (50000)
       --nopeerbloomfilters  Disable bloom filtering support.
+      --nocbfilters         Disable committed bloom filtering (CBF) support.
       --sigcachemaxsize=    The maximum number of entries in the signature
                             verification cache.
       --blocksonly          Do not accept transactions from remote peers.

sample-btcd.conf

@@ -167,6 +167,9 @@
 ; Must not include characters '/', ':', '(' and ')'.
 ; uacomment=
 
+; Disable committed peer bloom filtering (CBF).
+; nocbfilters=1
+
 ; ------------------------------------------------------------------------------
 ; RPC server options - The following options control the built-in RPC server
 ; which is used to control and query information from a running btcd process.

server.go

@@ -43,7 +43,8 @@ import (
 const (
 	// defaultServices describes the default services that are supported by
 	// the server.
-	defaultServices = wire.SFNodeNetwork | wire.SFNodeBloom | wire.SFNodeWitness
+	defaultServices = wire.SFNodeNetwork | wire.SFNodeBloom |
+		wire.SFNodeWitness | wire.SFNodeCF
 
 	// defaultRequiredServices describes the default services that are
 	// required to be supported by outbound peers.
@@ -2158,6 +2159,9 @@ func newServer(listenAddrs []string, db database.DB, chainParams *chaincfg.Param
 	if cfg.NoPeerBloomFilters {
 		services &^= wire.SFNodeBloom
 	}
+	if cfg.NoCBFilters {
+		services &^= wire.SFNodeCBF
+	}
 
 	amgr := addrmgr.New(cfg.DataDir, btcdLookup)