Switch dependency tracking to Go modules.

With that bump minimum required version to Go 1.13.

api_proxy.go

@@ -0,0 +1,270 @@
+/**
+ * Standalone signaling server for the Nextcloud Spreed app.
+ * Copyright (C) 2020 struktur AG
+ *
+ * @author Joachim Bauch <bauch@struktur.de>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package signaling
+
+import (
+	"fmt"
+
+	"gopkg.in/dgrijalva/jwt-go.v3"
+)
+
+type ProxyClientMessage struct {
+	// The unique request id (optional).
+	Id string `json:"id,omitempty"`
+
+	// The type of the request.
+	Type string `json:"type"`
+
+	// Filled for type "hello"
+	Hello *HelloProxyClientMessage `json:"hello,omitempty"`
+
+	Bye *ByeProxyClientMessage `json:"bye,omitempty"`
+
+	Command *CommandProxyClientMessage `json:"command,omitempty"`
+
+	Payload *PayloadProxyClientMessage `json:"payload,omitempty"`
+}
+
+func (m *ProxyClientMessage) CheckValid() error {
+	switch m.Type {
+	case "":
+		return fmt.Errorf("type missing")
+	case "hello":
+		if m.Hello == nil {
+			return fmt.Errorf("hello missing")
+		} else if err := m.Hello.CheckValid(); err != nil {
+			return err
+		}
+	case "bye":
+		if m.Bye != nil {
+			// Bye contents are optional
+			if err := m.Bye.CheckValid(); err != nil {
+				return err
+			}
+		}
+	case "command":
+		if m.Command == nil {
+			return fmt.Errorf("command missing")
+		} else if err := m.Command.CheckValid(); err != nil {
+			return err
+		}
+	case "payload":
+		if m.Payload == nil {
+			return fmt.Errorf("payload missing")
+		} else if err := m.Payload.CheckValid(); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (m *ProxyClientMessage) NewErrorServerMessage(e *Error) *ProxyServerMessage {
+	return &ProxyServerMessage{
+		Id:    m.Id,
+		Type:  "error",
+		Error: e,
+	}
+}
+
+func (m *ProxyClientMessage) NewWrappedErrorServerMessage(e error) *ProxyServerMessage {
+	return m.NewErrorServerMessage(NewError("internal_error", e.Error()))
+}
+
+// ProxyServerMessage is a message that is sent from the server to a client.
+type ProxyServerMessage struct {
+	Id string `json:"id,omitempty"`
+
+	Type string `json:"type"`
+
+	Error *Error `json:"error,omitempty"`
+
+	Hello *HelloProxyServerMessage `json:"hello,omitempty"`
+
+	Bye *ByeProxyServerMessage `json:"bye,omitempty"`
+
+	Command *CommandProxyServerMessage `json:"command,omitempty"`
+
+	Payload *PayloadProxyServerMessage `json:"payload,omitempty"`
+
+	Event *EventProxyServerMessage `json:"event,omitempty"`
+}
+
+func (r *ProxyServerMessage) CloseAfterSend(session Session) bool {
+	if r.Type == "bye" {
+		return true
+	}
+
+	return false
+}
+
+// Type "hello"
+
+type TokenClaims struct {
+	jwt.StandardClaims
+}
+
+type HelloProxyClientMessage struct {
+	Version string `json:"version"`
+
+	ResumeId string `json:"resumeid"`
+
+	Features []string `json:"features,omitempty"`
+
+	// The authentication credentials.
+	Token string `json:"token"`
+}
+
+func (m *HelloProxyClientMessage) CheckValid() error {
+	if m.Version != HelloVersion {
+		return fmt.Errorf("unsupported hello version: %s", m.Version)
+	}
+	if m.ResumeId == "" {
+		if m.Token == "" {
+			return fmt.Errorf("token missing")
+		}
+	}
+	return nil
+}
+
+type HelloProxyServerMessage struct {
+	Version string `json:"version"`
+
+	SessionId string                    `json:"sessionid"`
+	Server    *HelloServerMessageServer `json:"server,omitempty"`
+}
+
+// Type "bye"
+
+type ByeProxyClientMessage struct {
+}
+
+func (m *ByeProxyClientMessage) CheckValid() error {
+	// No additional validation required.
+	return nil
+}
+
+type ByeProxyServerMessage struct {
+	Reason string `json:"reason"`
+}
+
+// Type "command"
+
+type CommandProxyClientMessage struct {
+	Type string `json:"type"`
+
+	StreamType  string `json:"streamType,omitempty"`
+	PublisherId string `json:"publisherId,omitempty"`
+	ClientId    string `json:"clientId,omitempty"`
+}
+
+func (m *CommandProxyClientMessage) CheckValid() error {
+	switch m.Type {
+	case "":
+		return fmt.Errorf("type missing")
+	case "create-publisher":
+		if m.StreamType == "" {
+			return fmt.Errorf("stream type missing")
+		}
+	case "create-subscriber":
+		if m.PublisherId == "" {
+			return fmt.Errorf("publisher id missing")
+		}
+		if m.StreamType == "" {
+			return fmt.Errorf("stream type missing")
+		}
+	case "delete-publisher":
+		fallthrough
+	case "delete-subscriber":
+		if m.ClientId == "" {
+			return fmt.Errorf("client id missing")
+		}
+	}
+	return nil
+}
+
+type CommandProxyServerMessage struct {
+	Id string `json:"id,omitempty"`
+}
+
+// Type "payload"
+
+type PayloadProxyClientMessage struct {
+	Type string `json:"type"`
+
+	ClientId string                 `json:"clientId"`
+	Payload  map[string]interface{} `json:"payload,omitempty"`
+}
+
+func (m *PayloadProxyClientMessage) CheckValid() error {
+	switch m.Type {
+	case "":
+		return fmt.Errorf("type missing")
+	case "offer":
+		fallthrough
+	case "answer":
+		fallthrough
+	case "candidate":
+		if len(m.Payload) == 0 {
+			return fmt.Errorf("payload missing")
+		}
+	case "endOfCandidates":
+		fallthrough
+	case "requestoffer":
+		// No payload required.
+	}
+	if m.ClientId == "" {
+		return fmt.Errorf("client id missing")
+	}
+	return nil
+}
+
+type PayloadProxyServerMessage struct {
+	Type string `json:"type"`
+
+	ClientId string                 `json:"clientId"`
+	Payload  map[string]interface{} `json:"payload"`
+}
+
+// Type "event"
+
+type EventProxyServerMessage struct {
+	Type string `json:"type"`
+
+	ClientId string `json:"clientId,omitempty"`
+	Load     int64  `json:"load,omitempty"`
+}
+
+// Information on a proxy in the etcd cluster.
+
+type ProxyInformationEtcd struct {
+	Address string `json:"address"`
+}
+
+func (p *ProxyInformationEtcd) CheckValid() error {
+	if p.Address == "" {
+		return fmt.Errorf("address missing")
+	}
+	if p.Address[len(p.Address)-1] != '/' {
+		p.Address += "/"
+	}
+	return nil
+}