source: code/trunk/downstream.go@ 54

Last change on this file since 54 was 54, checked in by contact, 5 years ago

Don't write to downstreamConn.messages directly

Use a helper function instead. This will allow us to change
downstreamConn implementation details without having to update the whole
codebase.
File size: 7.5 KB
Line 
1package jounce
2
3import (
4 "fmt"
5 "io"
6 "net"
7 "strings"
8
9 "gopkg.in/irc.v3"
10)
11
12type ircError struct {
13 Message *irc.Message
14}
15
16func newUnknownCommandError(cmd string) ircError {
17 return ircError{&irc.Message{
18 Command: irc.ERR_UNKNOWNCOMMAND,
19 Params: []string{
20 "*",
21 cmd,
22 "Unknown command",
23 },
24 }}
25}
26
27func newNeedMoreParamsError(cmd string) ircError {
28 return ircError{&irc.Message{
29 Command: irc.ERR_NEEDMOREPARAMS,
30 Params: []string{
31 "*",
32 cmd,
33 "Not enough parameters",
34 },
35 }}
36}
37
38func (err ircError) Error() string {
39 return err.Message.String()
40}
41
42type downstreamConn struct {
43 net net.Conn
44 irc *irc.Conn
45 srv *Server
46 logger Logger
47 messages chan<- *irc.Message
48
49 registered bool
50 user *user
51 closed bool
52 nick string
53 username string
54 realname string
55}
56
57func newDownstreamConn(srv *Server, netConn net.Conn) *downstreamConn {
58 msgs := make(chan *irc.Message, 64)
59 conn := &downstreamConn{
60 net: netConn,
61 irc: irc.NewConn(netConn),
62 srv: srv,
63 logger: &prefixLogger{srv.Logger, fmt.Sprintf("downstream %q: ", netConn.RemoteAddr())},
64 messages: msgs,
65 }
66
67 go func() {
68 for msg := range msgs {
69 if err := conn.irc.WriteMessage(msg); err != nil {
70 conn.logger.Printf("failed to write message: %v", err)
71 }
72 }
73 if err := conn.net.Close(); err != nil {
74 conn.logger.Printf("failed to close connection: %v", err)
75 } else {
76 conn.logger.Printf("connection closed")
77 }
78 }()
79
80 return conn
81}
82
83func (c *downstreamConn) prefix() *irc.Prefix {
84 return &irc.Prefix{
85 Name: c.nick,
86 User: c.username,
87 // TODO: fill the host?
88 }
89}
90
91func (c *downstreamConn) readMessages() error {
92 c.logger.Printf("new connection")
93
94 for {
95 msg, err := c.irc.ReadMessage()
96 if err == io.EOF {
97 break
98 } else if err != nil {
99 return fmt.Errorf("failed to read IRC command: %v", err)
100 }
101
102 err = c.handleMessage(msg)
103 if ircErr, ok := err.(ircError); ok {
104 ircErr.Message.Prefix = c.srv.prefix()
105 c.SendMessage(ircErr.Message)
106 } else if err != nil {
107 return fmt.Errorf("failed to handle IRC command %q: %v", msg.Command, err)
108 }
109
110 if c.closed {
111 return nil
112 }
113 }
114
115 return nil
116}
117
118func (c *downstreamConn) Close() error {
119 if c.closed {
120 return fmt.Errorf("downstream connection already closed")
121 }
122
123 if u := c.user; u != nil {
124 u.lock.Lock()
125 for i := range u.downstreamConns {
126 if u.downstreamConns[i] == c {
127 u.downstreamConns = append(u.downstreamConns[:i], u.downstreamConns[i+1:]...)
128 }
129 }
130 u.lock.Unlock()
131
132 // TODO: figure out a better way to advance the ring buffer consumer cursor
133 u.forEachUpstream(func(uc *upstreamConn) {
134 // TODO: let clients specify the ring buffer name in their username
135 uc.ring.Consumer("").Reset()
136 })
137 }
138
139 close(c.messages)
140 c.closed = true
141
142 return nil
143}
144
145func (c *downstreamConn) SendMessage(msg *irc.Message) {
146 c.messages <- msg
147}
148
149func (c *downstreamConn) handleMessage(msg *irc.Message) error {
150 switch msg.Command {
151 case "QUIT":
152 return c.Close()
153 case "PING":
154 // TODO: handle params
155 c.SendMessage(&irc.Message{
156 Prefix: c.srv.prefix(),
157 Command: "PONG",
158 Params: []string{c.srv.Hostname},
159 })
160 return nil
161 default:
162 if c.registered {
163 return c.handleMessageRegistered(msg)
164 } else {
165 return c.handleMessageUnregistered(msg)
166 }
167 }
168}
169
170func (c *downstreamConn) handleMessageUnregistered(msg *irc.Message) error {
171 switch msg.Command {
172 case "NICK":
173 if err := parseMessageParams(msg, &c.nick); err != nil {
174 return err
175 }
176 case "USER":
177 var username string
178 if err := parseMessageParams(msg, &username, nil, nil, &c.realname); err != nil {
179 return err
180 }
181 c.username = "~" + username
182 default:
183 c.logger.Printf("unhandled message: %v", msg)
184 return newUnknownCommandError(msg.Command)
185 }
186 if c.username != "" && c.nick != "" {
187 return c.register()
188 }
189 return nil
190}
191
192func (c *downstreamConn) register() error {
193 u := c.srv.getUser(strings.TrimPrefix(c.username, "~"))
194 if u == nil {
195 c.logger.Printf("failed authentication: unknown username %q", c.username)
196 c.SendMessage(&irc.Message{
197 Prefix: c.srv.prefix(),
198 Command: irc.ERR_PASSWDMISMATCH,
199 Params: []string{"*", "Invalid username or password"},
200 })
201 return nil
202 }
203
204 c.registered = true
205 c.user = u
206
207 u.lock.Lock()
208 u.downstreamConns = append(u.downstreamConns, c)
209 u.lock.Unlock()
210
211 c.SendMessage(&irc.Message{
212 Prefix: c.srv.prefix(),
213 Command: irc.RPL_WELCOME,
214 Params: []string{c.nick, "Welcome to jounce, " + c.nick},
215 })
216 c.SendMessage(&irc.Message{
217 Prefix: c.srv.prefix(),
218 Command: irc.RPL_YOURHOST,
219 Params: []string{c.nick, "Your host is " + c.srv.Hostname},
220 })
221 c.SendMessage(&irc.Message{
222 Prefix: c.srv.prefix(),
223 Command: irc.RPL_CREATED,
224 Params: []string{c.nick, "Who cares when the server was created?"},
225 })
226 c.SendMessage(&irc.Message{
227 Prefix: c.srv.prefix(),
228 Command: irc.RPL_MYINFO,
229 Params: []string{c.nick, c.srv.Hostname, "jounce", "aiwroO", "OovaimnqpsrtklbeI"},
230 })
231 c.SendMessage(&irc.Message{
232 Prefix: c.srv.prefix(),
233 Command: irc.ERR_NOMOTD,
234 Params: []string{c.nick, "No MOTD"},
235 })
236
237 u.forEachUpstream(func(uc *upstreamConn) {
238 // TODO: fix races accessing upstream connection data
239 for _, ch := range uc.channels {
240 if ch.complete {
241 forwardChannel(c, ch)
242 }
243 }
244
245 // TODO: let clients specify the ring buffer name in their username
246 consumer := uc.ring.Consumer("")
247 for {
248 // TODO: these messages will get lost if the connection is closed
249 msg := consumer.Consume()
250 if msg == nil {
251 break
252 }
253 c.SendMessage(msg)
254 }
255 })
256
257 return nil
258}
259
260func (c *downstreamConn) handleMessageRegistered(msg *irc.Message) error {
261 switch msg.Command {
262 case "USER":
263 return ircError{&irc.Message{
264 Command: irc.ERR_ALREADYREGISTERED,
265 Params: []string{c.nick, "You may not reregister"},
266 }}
267 case "NICK":
268 c.user.forEachUpstream(func(uc *upstreamConn) {
269 uc.messages <- msg
270 })
271 case "JOIN":
272 var name string
273 if err := parseMessageParams(msg, &name); err != nil {
274 return err
275 }
276
277 if ch, _ := c.user.getChannel(name); ch != nil {
278 break // already joined
279 }
280
281 // TODO: extract network name from channel name
282 return ircError{&irc.Message{
283 Command: irc.ERR_NOSUCHCHANNEL,
284 Params: []string{name, "Channel name ambiguous"},
285 }}
286 case "PART":
287 var name string
288 if err := parseMessageParams(msg, &name); err != nil {
289 return err
290 }
291
292 ch, err := c.user.getChannel(name)
293 if err != nil {
294 return err
295 }
296
297 ch.conn.messages <- msg
298 // TODO: remove channel from upstream config
299 case "MODE":
300 var name string
301 if err := parseMessageParams(msg, &name); err != nil {
302 return err
303 }
304
305 var modeStr string
306 if len(msg.Params) > 1 {
307 modeStr = msg.Params[1]
308 }
309
310 if msg.Prefix.Name != name {
311 ch, err := c.user.getChannel(name)
312 if err != nil {
313 return err
314 }
315
316 if modeStr != "" {
317 ch.conn.messages <- msg
318 } else {
319 c.SendMessage(&irc.Message{
320 Prefix: c.srv.prefix(),
321 Command: irc.RPL_CHANNELMODEIS,
322 Params: []string{ch.Name, string(ch.modes)},
323 })
324 }
325 } else {
326 if name != c.nick {
327 return ircError{&irc.Message{
328 Command: irc.ERR_USERSDONTMATCH,
329 Params: []string{c.nick, "Cannot change mode for other users"},
330 }}
331 }
332
333 if modeStr != "" {
334 c.user.forEachUpstream(func(uc *upstreamConn) {
335 uc.messages <- msg
336 })
337 } else {
338 c.SendMessage(&irc.Message{
339 Prefix: c.srv.prefix(),
340 Command: irc.RPL_UMODEIS,
341 Params: []string{""}, // TODO
342 })
343 }
344 }
345 default:
346 c.logger.Printf("unhandled message: %v", msg)
347 return newUnknownCommandError(msg.Command)
348 }
349 return nil
350}
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