rpc: Switch eth_subscribe to reverse calls

api/api_full.go

@@ -6,6 +6,8 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/filecoin-project/go-jsonrpc"
+
 	"github.com/google/uuid"
 	blocks "github.com/ipfs/go-block-format"
 	"github.com/ipfs/go-cid"
@@ -831,7 +833,7 @@ type FullNode interface {
 	//  - logs: notify new event logs that match a criteria
 	// params contains additional parameters used with the log event type
 	// The client will receive a stream of EthSubscriptionResponse values until EthUnsubscribe is called.
-	EthSubscribe(ctx context.Context, eventType string, params *ethtypes.EthSubscriptionParams) (<-chan ethtypes.EthSubscriptionResponse, error) //perm:write
+	EthSubscribe(ctx context.Context, eventType string, params *ethtypes.EthSubscriptionParams) (ethtypes.EthSubscriptionID, error) //perm:write
 
 	// Unsubscribe from a websocket subscription
 	EthUnsubscribe(ctx context.Context, id ethtypes.EthSubscriptionID) (bool, error) //perm:write
@@ -849,6 +851,12 @@ type FullNode interface {
 	RaftLeader(ctx context.Context) (peer.ID, error)       //perm:read
 }
 
+// reverse interface to the client, called after EthSubscribe
+type EthSubscriber interface {
+	// note: the parameter is ethtypes.EthSubscriptionResponse serialized as json object
+	EthSubscription(ctx context.Context, r jsonrpc.RawParams) error //rpc_method:eth_subscription notify:true
+}
+
 type StorageAsk struct {
 	Response *storagemarket.StorageAsk
 

api/proxy_gen.go

@@ -7,21 +7,13 @@ import (
 	"encoding/json"
 	"time"
 
-	"github.com/google/uuid"
-	blocks "github.com/ipfs/go-block-format"
-	"github.com/ipfs/go-cid"
-	"github.com/libp2p/go-libp2p/core/metrics"
-	"github.com/libp2p/go-libp2p/core/network"
-	"github.com/libp2p/go-libp2p/core/peer"
-	"github.com/libp2p/go-libp2p/core/protocol"
-	"golang.org/x/xerrors"
-
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-bitfield"
 	datatransfer "github.com/filecoin-project/go-data-transfer"
 	"github.com/filecoin-project/go-fil-markets/piecestore"
 	"github.com/filecoin-project/go-fil-markets/retrievalmarket"
 	"github.com/filecoin-project/go-fil-markets/storagemarket"
+	"github.com/filecoin-project/go-jsonrpc"
 	"github.com/filecoin-project/go-jsonrpc/auth"
 	"github.com/filecoin-project/go-state-types/abi"
 	"github.com/filecoin-project/go-state-types/builtin/v8/paych"
@@ -31,7 +23,6 @@ import (
 	"github.com/filecoin-project/go-state-types/dline"
 	abinetwork "github.com/filecoin-project/go-state-types/network"
 	"github.com/filecoin-project/go-state-types/proof"
-
 	apitypes "github.com/filecoin-project/lotus/api/types"
 	builtinactors "github.com/filecoin-project/lotus/chain/actors/builtin"
 	lminer "github.com/filecoin-project/lotus/chain/actors/builtin/miner"
@@ -44,25 +35,38 @@ import (
 	"github.com/filecoin-project/lotus/storage/sealer/fsutil"
 	"github.com/filecoin-project/lotus/storage/sealer/sealtasks"
 	"github.com/filecoin-project/lotus/storage/sealer/storiface"
+	"github.com/google/uuid"
+	blocks "github.com/ipfs/go-block-format"
+	"github.com/ipfs/go-cid"
+	"github.com/libp2p/go-libp2p/core/metrics"
+	"github.com/libp2p/go-libp2p/core/network"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/libp2p/go-libp2p/core/protocol"
+	"golang.org/x/xerrors"
 )
 
 var ErrNotSupported = xerrors.New("method not supported")
 
 type ChainIOStruct struct {
-	Internal struct {
+	Internal ChainIOMethods
+}
+
+type ChainIOMethods struct {
 	ChainHasObj func(p0 context.Context, p1 cid.Cid) (bool, error) ``
 
 	ChainPutObj func(p0 context.Context, p1 blocks.Block) error ``
 
 	ChainReadObj func(p0 context.Context, p1 cid.Cid) ([]byte, error) ``
 }
-}
 
 type ChainIOStub struct {
 }
 
 type CommonStruct struct {
-	Internal struct {
+	Internal CommonMethods
+}
+
+type CommonMethods struct {
 	AuthNew func(p0 context.Context, p1 []auth.Permission) ([]byte, error) `perm:"admin"`
 
 	AuthVerify func(p0 context.Context, p1 string) ([]auth.Permission, error) `perm:"read"`
@@ -85,7 +89,6 @@ type CommonStruct struct {
 
 	Version func(p0 context.Context) (APIVersion, error) `perm:"read"`
 }
-}
 
 type CommonStub struct {
 }
@@ -95,8 +98,10 @@ type CommonNetStruct struct {
 
 	NetStruct
 
-	Internal struct {
+	Internal CommonNetMethods
 }
+
+type CommonNetMethods struct {
 }
 
 type CommonNetStub struct {
@@ -105,12 +110,26 @@ type CommonNetStub struct {
 	NetStub
 }
 
+type EthSubscriberStruct struct {
+	Internal EthSubscriberMethods
+}
+
+type EthSubscriberMethods struct {
+	EthSubscription func(p0 context.Context, p1 jsonrpc.RawParams) error `notify:"true"rpc_method:"eth_subscription"`
+}
+
+type EthSubscriberStub struct {
+}
+
 type FullNodeStruct struct {
 	CommonStruct
 
 	NetStruct
 
-	Internal struct {
+	Internal FullNodeMethods
+}
+
+type FullNodeMethods struct {
 	ChainBlockstoreInfo func(p0 context.Context) (map[string]interface{}, error) `perm:"read"`
 
 	ChainCheckBlockstore func(p0 context.Context) error `perm:"admin"`
@@ -281,7 +300,7 @@ type FullNodeStruct struct {
 
 	EthSendRawTransaction func(p0 context.Context, p1 ethtypes.EthBytes) (ethtypes.EthHash, error) `perm:"read"`
 
-		EthSubscribe func(p0 context.Context, p1 string, p2 *ethtypes.EthSubscriptionParams) (<-chan ethtypes.EthSubscriptionResponse, error) `perm:"write"`
+	EthSubscribe func(p0 context.Context, p1 string, p2 *ethtypes.EthSubscriptionParams) (ethtypes.EthSubscriptionID, error) `perm:"write"`
 
 	EthUninstallFilter func(p0 context.Context, p1 ethtypes.EthFilterID) (bool, error) `perm:"write"`
 
@@ -585,7 +604,6 @@ type FullNodeStruct struct {
 
 	Web3ClientVersion func(p0 context.Context) (string, error) `perm:"read"`
 }
-}
 
 type FullNodeStub struct {
 	CommonStub
@@ -594,7 +612,10 @@ type FullNodeStub struct {
 }
 
 type GatewayStruct struct {
-	Internal struct {
+	Internal GatewayMethods
+}
+
+type GatewayMethods struct {
 	ChainGetBlockMessages func(p0 context.Context, p1 cid.Cid) (*BlockMessages, error) ``
 
 	ChainGetGenesis func(p0 context.Context) (*types.TipSet, error) ``
@@ -739,13 +760,15 @@ type GatewayStruct struct {
 
 	WalletBalance func(p0 context.Context, p1 address.Address) (types.BigInt, error) ``
 }
-}
 
 type GatewayStub struct {
 }
 
 type NetStruct struct {
-	Internal struct {
+	Internal NetMethods
+}
+
+type NetMethods struct {
 	ID func(p0 context.Context) (peer.ID, error) `perm:"read"`
 
 	NetAddrsListen func(p0 context.Context) (peer.AddrInfo, error) `perm:"read"`
@@ -794,15 +817,16 @@ type NetStruct struct {
 
 	NetStat func(p0 context.Context, p1 string) (NetStat, error) `perm:"read"`
 }
-}
 
 type NetStub struct {
 }
 
 type SignableStruct struct {
-	Internal struct {
+	Internal SignableMethods
-		Sign func(p0 context.Context, p1 SignFunc) error ``
 }
+
+type SignableMethods struct {
+	Sign func(p0 context.Context, p1 SignFunc) error ``
 }
 
 type SignableStub struct {
@@ -813,7 +837,10 @@ type StorageMinerStruct struct {
 
 	NetStruct
 
-	Internal struct {
+	Internal StorageMinerMethods
+}
+
+type StorageMinerMethods struct {
 	ActorAddress func(p0 context.Context) (address.Address, error) `perm:"read"`
 
 	ActorAddressConfig func(p0 context.Context) (AddressConfig, error) `perm:"read"`
@@ -1078,7 +1105,6 @@ type StorageMinerStruct struct {
 
 	WorkerStats func(p0 context.Context) (map[uuid.UUID]storiface.WorkerStats, error) `perm:"admin"`
 }
-}
 
 type StorageMinerStub struct {
 	CommonStub
@@ -1087,7 +1113,10 @@ type StorageMinerStub struct {
 }
 
 type WalletStruct struct {
-	Internal struct {
+	Internal WalletMethods
+}
+
+type WalletMethods struct {
 	WalletDelete func(p0 context.Context, p1 address.Address) error `perm:"admin"`
 
 	WalletExport func(p0 context.Context, p1 address.Address) (*types.KeyInfo, error) `perm:"admin"`
@@ -1102,13 +1131,15 @@ type WalletStruct struct {
 
 	WalletSign func(p0 context.Context, p1 address.Address, p2 []byte, p3 MsgMeta) (*crypto.Signature, error) `perm:"admin"`
 }
-}
 
 type WalletStub struct {
 }
 
 type WorkerStruct struct {
-	Internal struct {
+	Internal WorkerMethods
+}
+
+type WorkerMethods struct {
 	AddPiece func(p0 context.Context, p1 storiface.SectorRef, p2 []abi.UnpaddedPieceSize, p3 abi.UnpaddedPieceSize, p4 storiface.Data) (storiface.CallID, error) `perm:"admin"`
 
 	DataCid func(p0 context.Context, p1 abi.UnpaddedPieceSize, p2 storiface.Data) (storiface.CallID, error) `perm:"admin"`
@@ -1183,7 +1214,6 @@ type WorkerStruct struct {
 
 	WaitQuiet func(p0 context.Context) error `perm:"admin"`
 }
-}
 
 type WorkerStub struct {
 }
@@ -1342,6 +1372,17 @@ func (s *CommonStub) Version(p0 context.Context) (APIVersion, error) {
 	return *new(APIVersion), ErrNotSupported
 }
 
+func (s *EthSubscriberStruct) EthSubscription(p0 context.Context, p1 jsonrpc.RawParams) error {
+	if s.Internal.EthSubscription == nil {
+		return ErrNotSupported
+	}
+	return s.Internal.EthSubscription(p0, p1)
+}
+
+func (s *EthSubscriberStub) EthSubscription(p0 context.Context, p1 jsonrpc.RawParams) error {
+	return ErrNotSupported
+}
+
 func (s *FullNodeStruct) ChainBlockstoreInfo(p0 context.Context) (map[string]interface{}, error) {
 	if s.Internal.ChainBlockstoreInfo == nil {
 		return *new(map[string]interface{}), ErrNotSupported
@@ -2277,15 +2318,15 @@ func (s *FullNodeStub) EthSendRawTransaction(p0 context.Context, p1 ethtypes.Eth
 	return *new(ethtypes.EthHash), ErrNotSupported
 }
 
-func (s *FullNodeStruct) EthSubscribe(p0 context.Context, p1 string, p2 *ethtypes.EthSubscriptionParams) (<-chan ethtypes.EthSubscriptionResponse, error) {
+func (s *FullNodeStruct) EthSubscribe(p0 context.Context, p1 string, p2 *ethtypes.EthSubscriptionParams) (ethtypes.EthSubscriptionID, error) {
 	if s.Internal.EthSubscribe == nil {
-		return nil, ErrNotSupported
+		return *new(ethtypes.EthSubscriptionID), ErrNotSupported
 	}
 	return s.Internal.EthSubscribe(p0, p1, p2)
 }
 
-func (s *FullNodeStub) EthSubscribe(p0 context.Context, p1 string, p2 *ethtypes.EthSubscriptionParams) (<-chan ethtypes.EthSubscriptionResponse, error) {
+func (s *FullNodeStub) EthSubscribe(p0 context.Context, p1 string, p2 *ethtypes.EthSubscriptionParams) (ethtypes.EthSubscriptionID, error) {
-	return nil, ErrNotSupported
+	return *new(ethtypes.EthSubscriptionID), ErrNotSupported
 }
 
 func (s *FullNodeStruct) EthUninstallFilter(p0 context.Context, p1 ethtypes.EthFilterID) (bool, error) {
@@ -6955,6 +6996,7 @@ func (s *WorkerStub) WaitQuiet(p0 context.Context) error {
 var _ ChainIO = new(ChainIOStruct)
 var _ Common = new(CommonStruct)
 var _ CommonNet = new(CommonNetStruct)
+var _ EthSubscriber = new(EthSubscriberStruct)
 var _ FullNode = new(FullNodeStruct)
 var _ Gateway = new(GatewayStruct)
 var _ Net = new(NetStruct)

api/v0api/proxy_gen.go

@@ -5,11 +5,6 @@ package v0api
 import (
 	"context"
 
-	blocks "github.com/ipfs/go-block-format"
-	"github.com/ipfs/go-cid"
-	"github.com/libp2p/go-libp2p/core/peer"
-	"golang.org/x/xerrors"
-
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-bitfield"
 	datatransfer "github.com/filecoin-project/go-data-transfer"
@@ -22,7 +17,6 @@ import (
 	"github.com/filecoin-project/go-state-types/crypto"
 	"github.com/filecoin-project/go-state-types/dline"
 	abinetwork "github.com/filecoin-project/go-state-types/network"
-
 	"github.com/filecoin-project/lotus/api"
 	apitypes "github.com/filecoin-project/lotus/api/types"
 	lminer "github.com/filecoin-project/lotus/chain/actors/builtin/miner"
@@ -30,6 +24,10 @@ import (
 	marketevents "github.com/filecoin-project/lotus/markets/loggers"
 	"github.com/filecoin-project/lotus/node/modules/dtypes"
 	"github.com/filecoin-project/lotus/node/repo/imports"
+	blocks "github.com/ipfs/go-block-format"
+	"github.com/ipfs/go-cid"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"golang.org/x/xerrors"
 )
 
 var ErrNotSupported = xerrors.New("method not supported")
@@ -39,7 +37,10 @@ type FullNodeStruct struct {
 
 	NetStruct
 
-	Internal struct {
+	Internal FullNodeMethods
+}
+
+type FullNodeMethods struct {
 	BeaconGetEntry func(p0 context.Context, p1 abi.ChainEpoch) (*types.BeaconEntry, error) `perm:"read"`
 
 	ChainDeleteObj func(p0 context.Context, p1 cid.Cid) error `perm:"admin"`
@@ -416,7 +417,6 @@ type FullNodeStruct struct {
 
 	WalletVerify func(p0 context.Context, p1 address.Address, p2 []byte, p3 *crypto.Signature) (bool, error) `perm:"read"`
 }
-}
 
 type FullNodeStub struct {
 	CommonStub
@@ -425,7 +425,10 @@ type FullNodeStub struct {
 }
 
 type GatewayStruct struct {
-	Internal struct {
+	Internal GatewayMethods
+}
+
+type GatewayMethods struct {
 	ChainGetBlockMessages func(p0 context.Context, p1 cid.Cid) (*api.BlockMessages, error) ``
 
 	ChainGetMessage func(p0 context.Context, p1 cid.Cid) (*types.Message, error) ``
@@ -490,7 +493,6 @@ type GatewayStruct struct {
 
 	WalletBalance func(p0 context.Context, p1 address.Address) (types.BigInt, error) ``
 }
-}
 
 type GatewayStub struct {
 }

gateway/handler.go

@@ -34,7 +34,7 @@ func Handler(gwapi lapi.Gateway, api lapi.FullNode, rateLimit int64, connPerMinu
 	m := mux.NewRouter()
 
 	serveRpc := func(path string, hnd interface{}) {
-		rpcServer := jsonrpc.NewServer(append(opts, jsonrpc.WithServerErrors(lapi.RPCErrors))...)
+		rpcServer := jsonrpc.NewServer(append(opts, jsonrpc.WithReverseClient[lapi.EthSubscriberMethods]("Filecoin"), jsonrpc.WithServerErrors(lapi.RPCErrors))...)
 		rpcServer.Register("Filecoin", hnd)
 		rpcServer.AliasMethod("rpc.discover", "Filecoin.Discover")
 

gen/api/proxygen.go

@@ -259,7 +259,7 @@ func generate(path, pkg, outpkg, outfile string) error {
 						if len(tf) != 2 {
 							continue
 						}
-						if tf[0] != "perm" { // todo: allow more tag types
+						if tf[0] != "perm" && tf[0] != "rpc_method" && tf[0] != "notify" { // todo: allow more tag types
 							continue
 						}
 						info.Methods[mname].Tags[tf[0]] = tf
@@ -302,12 +302,14 @@ type {{.Num}}Struct struct {
 {{range .Include}}
 	{{.}}Struct
 {{end}}
-	Internal struct {
+	Internal {{.Num}}Methods
+}
+
+type {{.Num}}Methods struct {
 {{range .Methods}}
 		{{.Num}} func({{.NamedParams}}) ({{.Results}}) `+"`"+`{{range .Tags}}{{index . 0}}:"{{index . 1}}"{{end}}`+"`"+`
 {{end}}
 	}
-}
 
 type {{.Num}}Stub struct {
 {{range .Include}}

go.mod

@@ -40,7 +40,7 @@ require (
 	github.com/filecoin-project/go-fil-commcid v0.1.0
 	github.com/filecoin-project/go-fil-commp-hashhash v0.1.0
 	github.com/filecoin-project/go-fil-markets v1.25.2
-	github.com/filecoin-project/go-jsonrpc v0.1.9
+	github.com/filecoin-project/go-jsonrpc v0.1.10-0.20230116095704-da92324a76e1
 	github.com/filecoin-project/go-legs v0.4.4
 	github.com/filecoin-project/go-padreader v0.0.1
 	github.com/filecoin-project/go-paramfetch v0.0.4

go.sum

@@ -342,6 +342,8 @@ github.com/filecoin-project/go-hamt-ipld/v3 v3.1.0 h1:rVVNq0x6RGQIzCo1iiJlGFm9AG
 github.com/filecoin-project/go-hamt-ipld/v3 v3.1.0/go.mod h1:bxmzgT8tmeVQA1/gvBwFmYdT8SOFUwB3ovSUfG1Ux0g=
 github.com/filecoin-project/go-jsonrpc v0.1.9 h1:HRWLxo7HAWzI3xZGeFG4LZJoYpms+Q+8kwmMTLnyS3A=
 github.com/filecoin-project/go-jsonrpc v0.1.9/go.mod h1:XBBpuKIMaXIIzeqzO1iucq4GvbF8CxmXRFoezRh+Cx4=
+github.com/filecoin-project/go-jsonrpc v0.1.10-0.20230116095704-da92324a76e1 h1:GcF3gSvesv1epB2SrTfalrYvhFzT1UnmSS1Bh+jprQY=
+github.com/filecoin-project/go-jsonrpc v0.1.10-0.20230116095704-da92324a76e1/go.mod h1:jBSvPTl8V1N7gSTuCR4bis8wnQnIjHbRPpROol6iQKM=
 github.com/filecoin-project/go-legs v0.4.4 h1:mpMmAOOnamaz0CV9rgeKhEWA8j9kMC+f+UGCGrxKaZo=
 github.com/filecoin-project/go-legs v0.4.4/go.mod h1:JQ3hA6xpJdbR8euZ2rO0jkxaMxeidXf0LDnVuqPAe9s=
 github.com/filecoin-project/go-padreader v0.0.0-20200903213702-ed5fae088b20/go.mod h1:mPn+LRRd5gEKNAtc+r3ScpW2JRU/pj4NBKdADYWHiak=

node/impl/full/eth.go

@@ -3,8 +3,10 @@ package full
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
+	"github.com/filecoin-project/go-jsonrpc"
 	"strconv"
 	"sync"
 	"time"
@@ -75,7 +77,7 @@ type EthEventAPI interface {
 	EthNewBlockFilter(ctx context.Context) (ethtypes.EthFilterID, error)
 	EthNewPendingTransactionFilter(ctx context.Context) (ethtypes.EthFilterID, error)
 	EthUninstallFilter(ctx context.Context, id ethtypes.EthFilterID) (bool, error)
-	EthSubscribe(ctx context.Context, eventType string, params *ethtypes.EthSubscriptionParams) (<-chan ethtypes.EthSubscriptionResponse, error)
+	EthSubscribe(ctx context.Context, eventType string, params *ethtypes.EthSubscriptionParams) (ethtypes.EthSubscriptionID, error)
 	EthUnsubscribe(ctx context.Context, id ethtypes.EthSubscriptionID) (bool, error)
 }
 
@@ -1100,16 +1102,19 @@ const (
 	EthSubscribeEventTypeLogs  = "logs"
 )
 
-func (e *EthEvent) EthSubscribe(ctx context.Context, eventType string, params *ethtypes.EthSubscriptionParams) (<-chan ethtypes.EthSubscriptionResponse, error) {
+func (e *EthEvent) EthSubscribe(ctx context.Context, eventType string, params *ethtypes.EthSubscriptionParams) (ethtypes.EthSubscriptionID, error) {
 	if e.SubManager == nil {
-		return nil, api.ErrNotSupported
+		return ethtypes.EthSubscriptionID{}, api.ErrNotSupported
 	}
-	// Note that go-jsonrpc will set the method field of the response to "xrpc.ch.val" but the ethereum api expects the name of the
-	// method to be "eth_subscription". This probably doesn't matter in practice.
 
-	sub, err := e.SubManager.StartSubscription(ctx)
+	ethCb, ok := jsonrpc.ExtractReverseClient[api.EthSubscriberMethods](ctx)
+	if !ok {
+		return ethtypes.EthSubscriptionID{}, xerrors.Errorf("connection doesn't support callbacks")
+	}
+
+	sub, err := e.SubManager.StartSubscription(ctx, ethCb.EthSubscription)
 	if err != nil {
-		return nil, err
+		return ethtypes.EthSubscriptionID{}, err
 	}
 
 	switch eventType {
@@ -1118,7 +1123,7 @@ func (e *EthEvent) EthSubscribe(ctx context.Context, eventType string, params *e
 		if err != nil {
 			// clean up any previous filters added and stop the sub
 			_, _ = e.EthUnsubscribe(ctx, sub.id)
-			return nil, err
+			return ethtypes.EthSubscriptionID{}, err
 		}
 		sub.addFilter(ctx, f)
 
@@ -1138,14 +1143,14 @@ func (e *EthEvent) EthSubscribe(ctx context.Context, eventType string, params *e
 		if err != nil {
 			// clean up any previous filters added and stop the sub
 			_, _ = e.EthUnsubscribe(ctx, sub.id)
-			return nil, err
+			return ethtypes.EthSubscriptionID{}, err
 		}
 		sub.addFilter(ctx, f)
 	default:
-		return nil, xerrors.Errorf("unsupported event type: %s", eventType)
+		return ethtypes.EthSubscriptionID{}, xerrors.Errorf("unsupported event type: %s", eventType)
 	}
 
-	return sub.out, nil
+	return sub.id, nil
 }
 
 func (e *EthEvent) EthUnsubscribe(ctx context.Context, id ethtypes.EthSubscriptionID) (bool, error) {
@@ -1294,7 +1299,7 @@ type EthSubscriptionManager struct {
 	subs     map[ethtypes.EthSubscriptionID]*ethSubscription
 }
 
-func (e *EthSubscriptionManager) StartSubscription(ctx context.Context) (*ethSubscription, error) { // nolint
+func (e *EthSubscriptionManager) StartSubscription(ctx context.Context, out ethSubscriptionCallback) (*ethSubscription, error) { // nolint
 	rawid, err := uuid.NewRandom()
 	if err != nil {
 		return nil, xerrors.Errorf("new uuid: %w", err)
@@ -1310,7 +1315,7 @@ func (e *EthSubscriptionManager) StartSubscription(ctx context.Context) (*ethSub
 		ChainAPI: e.ChainAPI,
 		id:       id,
 		in:       make(chan interface{}, 200),
-		out:      make(chan ethtypes.EthSubscriptionResponse, 20),
+		out:      out,
 		quit:     quit,
 	}
 
@@ -1340,13 +1345,15 @@ func (e *EthSubscriptionManager) StopSubscription(ctx context.Context, id ethtyp
 	return sub.filters, nil
 }
 
+type ethSubscriptionCallback func(context.Context, jsonrpc.RawParams) error
+
 type ethSubscription struct {
 	Chain    *store.ChainStore
 	StateAPI StateAPI
 	ChainAPI ChainAPI
 	id       ethtypes.EthSubscriptionID
 	in       chan interface{}
-	out      chan ethtypes.EthSubscriptionResponse
+	out      ethSubscriptionCallback
 
 	mu      sync.Mutex
 	filters []filter.Filter
@@ -1390,10 +1397,15 @@ func (e *ethSubscription) start(ctx context.Context) {
 				continue
 			}
 
-			select {
+			outParam, err := json.Marshal(resp)
-			case e.out <- resp:
+			if err != nil {
-			default:
+				log.Warnw("marshaling subscription response", "sub", e.id, "error", err)
-				// Skip if client is not reading responses
+				continue
+			}
+
+			if err := e.out(ctx, outParam); err != nil {
+				log.Warnw("sending subscription response", "sub", e.id, "error", err)
+				continue
 			}
 		}
 	}
@@ -1405,7 +1417,6 @@ func (e *ethSubscription) stop() {
 
 	if e.quit != nil {
 		e.quit()
-		close(e.out)
 		e.quit = nil
 	}
 }

node/rpc.go

@@ -75,7 +75,7 @@ func FullNodeHandler(a v1api.FullNode, permissioned bool, opts ...jsonrpc.Server
 	m := mux.NewRouter()
 
 	serveRpc := func(path string, hnd interface{}) {
-		rpcServer := jsonrpc.NewServer(append(opts, jsonrpc.WithServerErrors(api.RPCErrors))...)
+		rpcServer := jsonrpc.NewServer(append(opts, jsonrpc.WithReverseClient[api.EthSubscriberMethods]("Filecoin"), jsonrpc.WithServerErrors(api.RPCErrors))...)
 		rpcServer.Register("Filecoin", hnd)
 		rpcServer.AliasMethod("rpc.discover", "Filecoin.Discover")