source: code/trunk/server.go@ 11

Last change on this file since 11 was 11, checked in by contact, 5 years ago

Add basic upstream message handler
File size: 5.9 KB
Line 
1package jounce
2
3import (
4 "crypto/tls"
5 "fmt"
6 "io"
7 "log"
8 "net"
9
10 "gopkg.in/irc.v3"
11)
12
13type Logger interface {
14 Print(v ...interface{})
15 Printf(format string, v ...interface{})
16}
17
18type ircError struct {
19 Message *irc.Message
20}
21
22func newUnknownCommandError(cmd string) ircError {
23 return ircError{&irc.Message{
24 Command: irc.ERR_UNKNOWNCOMMAND,
25 Params: []string{
26 "*",
27 cmd,
28 "Unknown command",
29 },
30 }}
31}
32
33func newNeedMoreParamsError(cmd string) ircError {
34 return ircError{&irc.Message{
35 Command: irc.ERR_NEEDMOREPARAMS,
36 Params: []string{
37 "*",
38 cmd,
39 "Not enough parameters",
40 },
41 }}
42}
43
44func (err ircError) Error() string {
45 return err.Message.String()
46}
47
48type downstreamConn struct {
49 net net.Conn
50 irc *irc.Conn
51 srv *Server
52 registered bool
53 closed bool
54 nick string
55 username string
56 realname string
57}
58
59func (c *downstreamConn) Close() error {
60 if err := c.net.Close(); err != nil {
61 return err
62 }
63 c.closed = true
64 return nil
65}
66
67func (c *downstreamConn) WriteMessage(msg *irc.Message) error {
68 msg.Prefix = c.srv.prefix()
69 return c.irc.WriteMessage(msg)
70}
71
72func (c *downstreamConn) handleMessage(msg *irc.Message) error {
73 switch msg.Command {
74 case "PING":
75 // TODO: handle params
76 return c.WriteMessage(&irc.Message{
77 Command: "PONG",
78 Params: []string{c.srv.Hostname},
79 })
80 default:
81 if c.registered {
82 return c.handleMessageRegistered(msg)
83 } else {
84 return c.handleMessageUnregistered(msg)
85 }
86 }
87}
88
89func (c *downstreamConn) handleMessageUnregistered(msg *irc.Message) error {
90 switch msg.Command {
91 case "NICK":
92 if len(msg.Params) != 1 {
93 return newNeedMoreParamsError(msg.Command)
94 }
95 c.nick = msg.Params[0]
96 case "USER":
97 if len(msg.Params) != 4 {
98 return newNeedMoreParamsError(msg.Command)
99 }
100 c.username = "~" + msg.Params[0]
101 c.realname = msg.Params[3]
102 case "QUIT":
103 return c.Close()
104 default:
105 return newUnknownCommandError(msg.Command)
106 }
107 if c.username != "" && c.nick != "" {
108 return c.register()
109 }
110 return nil
111}
112
113func (c *downstreamConn) register() error {
114 c.registered = true
115
116 err := c.WriteMessage(&irc.Message{
117 Command: irc.RPL_WELCOME,
118 Params: []string{c.nick, "Welcome to jounce, " + c.nick},
119 })
120 if err != nil {
121 return err
122 }
123
124 err = c.WriteMessage(&irc.Message{
125 Command: irc.RPL_YOURHOST,
126 Params: []string{c.nick, "Your host is " + c.srv.Hostname},
127 })
128 if err != nil {
129 return err
130 }
131
132 err = c.WriteMessage(&irc.Message{
133 Command: irc.RPL_CREATED,
134 Params: []string{c.nick, "This server was created <datetime>"}, // TODO
135 })
136 if err != nil {
137 return err
138 }
139
140 err = c.WriteMessage(&irc.Message{
141 Command: irc.RPL_MYINFO,
142 Params: []string{c.nick, c.srv.Hostname, "unknown", "", ""},
143 })
144 if err != nil {
145 return err
146 }
147
148 err = c.WriteMessage(&irc.Message{
149 Command: irc.ERR_NOMOTD,
150 Params: []string{c.nick, "No MOTD"},
151 })
152 if err != nil {
153 return err
154 }
155
156 return nil
157}
158
159func (c *downstreamConn) handleMessageRegistered(msg *irc.Message) error {
160 switch msg.Command {
161 case "NICK", "USER":
162 return ircError{&irc.Message{
163 Command: irc.ERR_ALREADYREGISTERED,
164 Params: []string{
165 c.nick,
166 "You may not reregister",
167 },
168 }}
169 case "QUIT":
170 return c.Close()
171 default:
172 return newUnknownCommandError(msg.Command)
173 }
174}
175
176type upstreamConn struct {
177 net net.Conn
178 irc *irc.Conn
179 srv *Server
180}
181
182func (c *upstreamConn) handleMessage(msg *irc.Message) error {
183 switch msg.Command {
184 case "PING":
185 // TODO: handle params
186 return c.irc.WriteMessage(&irc.Message{
187 Command: "PONG",
188 Params: []string{c.srv.Hostname},
189 })
190 default:
191 c.srv.Logger.Printf("Unhandled upstream message: %v", msg)
192 return nil
193 }
194}
195
196type Upstream struct {
197 Addr string
198 Nick string
199 Username string
200 Realname string
201}
202
203type Server struct {
204 Hostname string
205 Logger Logger
206 Upstreams []Upstream // TODO: per-user
207}
208
209func (s *Server) prefix() *irc.Prefix {
210 return &irc.Prefix{Name: s.Hostname}
211}
212
213func (s *Server) handleConn(netConn net.Conn) error {
214 s.Logger.Printf("Handling connection from %v", netConn.RemoteAddr())
215
216 c := downstreamConn{net: netConn, irc: irc.NewConn(netConn), srv: s}
217 defer c.Close()
218 for {
219 msg, err := c.irc.ReadMessage()
220 if err == io.EOF {
221 break
222 } else if err != nil {
223 return fmt.Errorf("failed to read IRC command: %v", err)
224 }
225 s.Logger.Printf("Downstream message: %v", msg)
226
227 err = c.handleMessage(msg)
228 if ircErr, ok := err.(ircError); ok {
229 ircErr.Message.Prefix = s.prefix()
230 if err := c.WriteMessage(ircErr.Message); err != nil {
231 return fmt.Errorf("failed to write IRC reply: %v", err)
232 }
233 } else if err != nil {
234 return fmt.Errorf("failed to handle IRC command %q: %v", msg.Command, err)
235 }
236
237 if c.closed {
238 return nil
239 }
240 }
241
242 return c.Close()
243}
244
245func (s *Server) connect(upstream *Upstream) error {
246 s.Logger.Printf("Connecting to %v", upstream.Addr)
247
248 netConn, err := tls.Dial("tcp", upstream.Addr, nil)
249 if err != nil {
250 return fmt.Errorf("failed to dial %q: %v", upstream.Addr, err)
251 }
252
253 c := upstreamConn{net: netConn, irc: irc.NewConn(netConn), srv: s}
254 defer netConn.Close()
255
256 err = c.irc.WriteMessage(&irc.Message{
257 Command: "NICK",
258 Params: []string{upstream.Nick},
259 })
260 if err != nil {
261 return err
262 }
263
264 err = c.irc.WriteMessage(&irc.Message{
265 Command: "USER",
266 Params: []string{upstream.Username, "0", "*", upstream.Realname},
267 })
268 if err != nil {
269 return err
270 }
271
272 for {
273 msg, err := c.irc.ReadMessage()
274 if err == io.EOF {
275 break
276 } else if err != nil {
277 return fmt.Errorf("failed to read IRC command: %v", err)
278 }
279
280 if err := c.handleMessage(msg); err != nil {
281 return err
282 }
283 }
284
285 return netConn.Close()
286}
287
288func (s *Server) Run() {
289 for i := range s.Upstreams {
290 // TODO: retry connecting
291 go s.connect(&s.Upstreams[i])
292 }
293}
294
295func (s *Server) Serve(ln net.Listener) error {
296 for {
297 c, err := ln.Accept()
298 if err != nil {
299 return fmt.Errorf("failed to accept connection: %v", err)
300 }
301
302 go func() {
303 if err := s.handleConn(c); err != nil {
304 log.Printf("error handling connection: %v", err)
305 }
306 }()
307 }
308}
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