multi: Integrate mixpool and propagate p2p mixing messages

This commit adds the mixing message pool to the server and listens for all
peer-to-peer mixing messages broadcast on the network.  If these messages are
able to be accepted to the mixpool, they are relayed to other peers through
the inventory system, and notified to RPC clients.

This commit also also adds support for publishing and receiving mix messages
over JSON-RPC for non-SPV wallet clients.

go.mod

@@ -25,6 +25,7 @@ require (
 	github.com/decred/dcrd/gcs/v4 v4.0.0
 	github.com/decred/dcrd/lru v1.1.2
 	github.com/decred/dcrd/math/uint256 v1.0.1
+	github.com/decred/dcrd/mixing v0.0.1
 	github.com/decred/dcrd/peer/v3 v3.0.2
 	github.com/decred/dcrd/rpc/jsonrpc/types/v4 v4.0.0
 	github.com/decred/dcrd/rpcclient/v8 v8.0.0
@@ -38,18 +39,20 @@ require (
 	github.com/jrick/bitset v1.0.0
 	github.com/jrick/logrotate v1.0.0
 	github.com/syndtr/goleveldb v1.0.1-0.20210819022825-2ae1ddf74ef7
-	golang.org/x/sys v0.8.0
-	golang.org/x/term v0.5.0
+	golang.org/x/sys v0.20.0
+	golang.org/x/term v0.20.0
 	lukechampine.com/blake3 v1.3.0
 )
 
 require (
 	github.com/agl/ed25519 v0.0.0-20170116200512-5312a6153412 // indirect
+	github.com/companyzero/sntrup4591761 v0.0.0-20220309191932-9e0f3af2f07a // indirect
 	github.com/dchest/siphash v1.2.3 // indirect
 	github.com/decred/dcrd/dcrec/edwards/v2 v2.0.3 // indirect
 	github.com/decred/dcrd/hdkeychain/v3 v3.1.1 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/klauspost/cpuid/v2 v2.0.9 // indirect
+	golang.org/x/crypto v0.23.0 // indirect
 )
 
 replace (
@@ -75,6 +78,7 @@ replace (
 	github.com/decred/dcrd/limits => ./limits
 	github.com/decred/dcrd/lru => ./lru
 	github.com/decred/dcrd/math/uint256 => ./math/uint256
+	github.com/decred/dcrd/mixing => ./mixing
 	github.com/decred/dcrd/peer/v3 => ./peer
 	github.com/decred/dcrd/rpc/jsonrpc/types/v4 => ./rpc/jsonrpc/types
 	github.com/decred/dcrd/rpcclient/v8 => ./rpcclient

go.sum

@@ -1,5 +1,9 @@
+decred.org/cspp/v2 v2.2.0 h1:VSOUC1w0Wo+QOGS0r1XO6TLnO16X67KuvpDmRRYyr08=
+decred.org/cspp/v2 v2.2.0/go.mod h1:9nO3bfvCheOPIFZw5f6sRQ42CjBFB5RKSaJ9Iq6G4MA=
 github.com/agl/ed25519 v0.0.0-20170116200512-5312a6153412 h1:w1UutsfOrms1J05zt7ISrnJIXKzwaspym5BTKGx93EI=
 github.com/agl/ed25519 v0.0.0-20170116200512-5312a6153412/go.mod h1:WPjqKcmVOxf0XSf3YxCJs6N6AOSrOx3obionmG7T0y0=
+github.com/companyzero/sntrup4591761 v0.0.0-20220309191932-9e0f3af2f07a h1:clYxJ3Os0EQUKDDVU8M0oipllX0EkuFNBfhVQuIfyF0=
+github.com/companyzero/sntrup4591761 v0.0.0-20220309191932-9e0f3af2f07a/go.mod h1:z/9Ck1EDixEbBbZ2KH2qNHekEmDLTOZ+FyoIPWWSVOI=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dchest/siphash v1.2.3 h1:QXwFc8cFOR2dSa/gE6o/HokBMWtLUaNDVd+22aKHeEA=
@@ -53,11 +57,13 @@ github.com/syndtr/goleveldb v1.0.1-0.20210819022825-2ae1ddf74ef7 h1:epCh84lMvA70
 github.com/syndtr/goleveldb v1.0.1-0.20210819022825-2ae1ddf74ef7/go.mod h1:q4W45IWZaF22tdD+VEXcAWRA037jwmWEB5VWYORlTpc=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.23.0 h1:dIJU/v2J8Mdglj/8rJ6UUOM3Zc9zLZxVZwwxMooUSAI=
+golang.org/x/crypto v0.23.0/go.mod h1:CKFgDieR+mRhux2Lsu27y0fO304Db0wZe70UKqHu0v8=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/net v0.0.0-20200520004742-59133d7f0dd7/go.mod h1:qpuaurCH72eLCgpAm/N6yyVIVM9cpaDIP3A8BGJEC5A=
-golang.org/x/net v0.0.0-20200813134508-3edf25e44fcc h1:zK/HqS5bZxDptfPJNq8v7vJfXtkU7r9TLIoSr1bXaP4=
 golang.org/x/net v0.0.0-20200813134508-3edf25e44fcc/go.mod h1:/O7V0waA8r7cgGh81Ro3o1hOxt32SMVPicZroKQ2sZA=
+golang.org/x/net v0.21.0 h1:AQyQV4dYCvJ7vGmJyKki9+PBdyvhkSd8EIx/qb0AYv4=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -69,14 +75,14 @@ golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200519105757-fe76b779f299/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200814200057-3d37ad5750ed/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210320140829-1e4c9ba3b0c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.8.0 h1:EBmGv8NaZBZTWvrbjNoL6HVt+IVy3QDQpJs7VRIw3tU=
-golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/term v0.5.0 h1:n2a8QNdAb0sZNpU9R1ALUXBbY+w51fCQDN+7EdxNBsY=
-golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
+golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
+golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/term v0.20.0 h1:VnkxpohqXaOBYJtBmEppKUG6mXpi+4O6purfc2+sMhw=
+golang.org/x/term v0.20.0/go.mod h1:8UkIAJTvZgivsXaD6/pH6U9ecQzZ45awqEOzuCvwpFY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
-golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.15.0 h1:h1V/4gjBv8v9cjcR6+AR5+/cIYK5N/WAgiv4xlsEtAk=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=

internal/blockchain/chain.go

@@ -297,6 +297,11 @@ type BlockChain struct {
 	bulkImportMode bool
 }
 
+// ChainParams returns the chain parameters.
+func (b *BlockChain) ChainParams() *chaincfg.Params {
+	return b.chainParams
+}
+
 const (
 	// stakeMajorityCacheKeySize is comprised of the stake version and the
 	// hash size.  The stake version is a little endian uint32, hence we

internal/mempool/mempool.go

@@ -1084,6 +1084,22 @@ func (mp *TxPool) fetchInputUtxos(tx *dcrutil.Tx, isTreasuryEnabled bool) (*bloc
 	return utxoView, nil
 }
 
+// IsSpent returns whether the outpoint is spent by any transient or staged
+// transaction in the tx pool.  Outpoints that are not spent by transactions
+// in the pool may not exist or may be spent in blocks.
+func (mp *TxPool) IsSpent(outpoint wire.OutPoint) bool {
+	mp.mtx.RLock()
+	defer mp.mtx.RUnlock()
+
+	_, exists := mp.outpoints[outpoint]
+	if exists {
+		return true
+	}
+
+	_, exists = mp.stagedOutpoints[outpoint]
+	return exists
+}
+
 // FetchTransaction returns the requested transaction from the transaction pool.
 // This only fetches from the main and stage transaction pools and does not
 // include orphans.

internal/netsync/interface.go

@@ -6,6 +6,7 @@ package netsync
 
 import (
 	"github.com/decred/dcrd/dcrutil/v4"
+	"github.com/decred/dcrd/mixing"
 )
 
 // PeerNotifier provides an interface to notify peers of status changes related
@@ -14,4 +15,8 @@ type PeerNotifier interface {
 	// AnnounceNewTransactions generates and relays inventory vectors and
 	// notifies websocket clients of the passed transactions.
 	AnnounceNewTransactions(txns []*dcrutil.Tx)
+
+	// AnnounceMixMessage generates and relays inventory vectors of the
+	// passed messages.
+	AnnounceMixMessages(msgs []mixing.Message)
 }