Initial Store & Forward Implementation (#2917)

This adds store & forward relays into dendrite for p2p.
A few things have changed:
- new relay api serves new http endpoints for s&f federation
- updated outbound federation queueing which will attempt to forward
using s&f if appropriate
- database entries to track s&f relays for other nodes

relayapi/relayapi.go

@@ -0,0 +1,74 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package relayapi
+
+import (
+	"github.com/matrix-org/dendrite/federationapi/producers"
+	"github.com/matrix-org/dendrite/relayapi/api"
+	"github.com/matrix-org/dendrite/relayapi/internal"
+	"github.com/matrix-org/dendrite/relayapi/routing"
+	"github.com/matrix-org/dendrite/relayapi/storage"
+	rsAPI "github.com/matrix-org/dendrite/roomserver/api"
+	"github.com/matrix-org/dendrite/setup/base"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/sirupsen/logrus"
+)
+
+// AddPublicRoutes sets up and registers HTTP handlers on the base API muxes for the FederationAPI component.
+func AddPublicRoutes(
+	base *base.BaseDendrite,
+	keyRing gomatrixserverlib.JSONVerifier,
+	relayAPI api.RelayInternalAPI,
+) {
+	fedCfg := &base.Cfg.FederationAPI
+
+	relay, ok := relayAPI.(*internal.RelayInternalAPI)
+	if !ok {
+		panic("relayapi.AddPublicRoutes called with a RelayInternalAPI impl which was not " +
+			"RelayInternalAPI. This is a programming error.")
+	}
+
+	routing.Setup(
+		base.PublicFederationAPIMux,
+		fedCfg,
+		relay,
+		keyRing,
+	)
+}
+
+func NewRelayInternalAPI(
+	base *base.BaseDendrite,
+	fedClient *gomatrixserverlib.FederationClient,
+	rsAPI rsAPI.RoomserverInternalAPI,
+	keyRing *gomatrixserverlib.KeyRing,
+	producer *producers.SyncAPIProducer,
+) api.RelayInternalAPI {
+	cfg := &base.Cfg.RelayAPI
+
+	relayDB, err := storage.NewDatabase(base, &cfg.Database, base.Caches, base.Cfg.Global.IsLocalServerName)
+	if err != nil {
+		logrus.WithError(err).Panic("failed to connect to relay db")
+	}
+
+	return internal.NewRelayInternalAPI(
+		relayDB,
+		fedClient,
+		rsAPI,
+		keyRing,
+		producer,
+		base.Cfg.Global.Presence.EnableInbound,
+		base.Cfg.Global.ServerName,
+	)
+}